Microbiology COPY Flashcards

Question

How does transduction bacteria gene transfer work?

Answer 1

Genetic recombination where genes from a host cell (bacterium) are incorporated into a bacterial virus genome (bacteriophage) and then transferred to another bacteria when the bacteriophage infects another cell.

Answer 2

Bacteria that can only grow inside a host cell Therefore we cannot grow them on agar plates

Answer 3

Chlamydia Rickettsia Coxiella

Answer 4

ComeInAndStain 1. Apply primary stain - crystal violet (purple) - to heat fixed bacteria 2. Add iodine which binds to crystal violet and helps fix it to the cell wall 3. Decolourise with ethanol or acetone 4. Counterstain with safranin (pink)

Answer 5

Blood agar haemolysis

Answer 6

alpha haemolysis - partial (appears green) = Streptococcus pneumonia or Viridans group streptococcus Beta haemolysis - full = Group A,B,C,G strep - Requires further Lancefield serotype test to determine species Gamma haemolysis - none = Enterococcus

Answer 7

Optochin Test Optochin sensitive - Streptococcus pneumonia Optochin Resistant - Viridans group Streptococcus

Answer 8

Group A - Streptococcus pyogenes Group B - Streptococcus agalactiae

Answer 9

Gram negative Bacilli

Answer 10

Contains bile salts, lactose and a pH indicator If an organism ferments lactose - lactic acid is produce and the agar will appear red/pink.

Answer 11

Escherichia Coli Klebsiella pneumoniae Enterobacter

Answer 12

Salmonella Shigella Proteus Yersinia Pseudomonas

Answer 13

Haemoloysis on blood agar Lancefield typing (sero grouping based on surface carbohydrate antigens) Biochemical properties

Answer 14

Means that the bacteria likes aerobic conditions mainly but can adapt if conditions tun anaerobic

Answer 15

Streptococcus pyogenes

Answer 16

beta haemolysis Group A strep

Answer 17

Penicillin

Answer 18

Wound infections - cause cellulitis Tonsilitis and Pharyngitis Otitis media Impetigo Scarlet Fever

Answer 19

Can cause rheumatic fever Can cause glomerulonephritis

Answer 20

Streptokinase Streptolysin O and S Erythrogenic Toxin M Toxin

Answer 21

In the oropharynx in roughly 30% of the population

Answer 22

Pneumonia Otitis media Sinusitis Meningitis

Answer 23

Impaired mucus trapping (caused by viral infection) Hypogammaglobulinaemia (low antibody count) Asplenia - Absence of normal spleen function

Answer 24

Capsule - polysaccharide Inflammatory wall constituents - Teichoic acid and peptidoglycan Cytotoxin - pneumolysin.

Answer 25

They are sensitive to it so they die.

Answer 26

Viridans group streptococci

Answer 27

Dental caries and abscesses Infective endocarditis Deep organ abscesses

Answer 28

Mainly aerobic

Answer 29

Staphylococcus aureus

Answer 30

Nose and skin Spread via aerosol and touch

Answer 31

Positive result

Answer 32

This means that they can clot the blood plasma around the bacteria to attempt to protect themselves from phagocytosis

Answer 33

yellow colonies

Answer 34

Methicillin (flucloxacillin) Resistant Staphylococcus aureus

Answer 35

- β-lactams - Gentamicin - Erythromycin - Tetracycline

Answer 36

Vancomycin

Answer 37

1. Toxins: pore-forming e.g. **α-haemolysin and PVL** = causes hemorrhagic pneumonia 2. Proteases: **exfoliatin** = scalded skin syndrome 3. Toxic shock syndrome toxin (TSST): stimulates cytokine release 4. Protein A: a surface protein which binds Ig's in wrong orientation so they can't be recognised by the immune system.

Answer 38

Wound infections Abscesses Impetigo Septicaemia Osteomyelitis Pneumonia Endocarditis Toxins could also cause toxic shock syndrome and food poisoning

Answer 39

Negative result

Answer 40

White/colourless colonies

Answer 41

Its ability to form persistent biofilms

Answer 42

Prostheses Catheters Mainly affects immunocompromised individuals

Answer 43

Acute cystitis

Answer 44

Haemagglutinin - adhesion to cell Urease enzyme - cause kidney stones

Answer 45

C.diphtheriae

Answer 46

child with severe sore throat and fever for 2 days Lymphadenopathy in neck rapid breathing thick greyish membrane on tonsils Swab - shows irregular gram positive rods Stain shows metachromatic granules All leads to C.diphtheriae

Answer 47

Anti-toxin Erythromycin

Answer 48

Grow it in the presence of potassium tellurite This will kill other types of bacteria except corynebacterium

Answer 49

Via droplets

Answer 50

Vaccination Toxoid vaccine

Answer 51

Coagulase test; looks at whether a fibrin clot is produced

Answer 52

Positive - S.aureus Negative - S.epidermidis, S.saprophyticus

Answer 53

Proteobacteria Bacteroidetes Chlamydiae Spirochaetes

Answer 54

All gram negative bacilli (except Neisseria (diplococci) and Campylobacter/helicobacter (spiral))

Answer 55

Enterobacteriaceae Vibrio cholerae Pseudomonas aeruginosa Haemophilus influenzae Legionella pneumophila Bordetella pertussis Neisseria Campylobacter Helicobacter pylori

Answer 56

Rods - most have flagellum Facultatively anaerobic Some species will colonise the gut - both commensal and pathogenic

Answer 57

Enterobacteriaceae Vibrio cholerae Pseudomonas aeruginosa Haemophilus influenzae Legionella pneumophila Bordetella pertussis Neisseria Campylobacter Helicobacter pylori

Answer 58

Escherichia coli Shigella Salmonella Proteus mirabilis Klebsiella pneumonia

Answer 59

A commensal bacterium that is abundant as a facultative anaerobe They have a flagella

Answer 60

1. O antigen: part of LPS 2. K antigen: capsule 3. H antigen: flagellin

Answer 61

1. Wound infections (surgical) 2. UTIs (cystitis; ~80% of female UTIs - faecal source or sexual activity; catheterisation - most common nosocomial infection) 3. Gastroenteritis 4. Traveller's diarrhoea 5. Bacteriemia 6. Meningitis (infants) - rare in the UK

Answer 62

ETEC - Enterotoxigenic Escherichia coli EHEC - Enterohaemorrhagic Escherichia coli EPEC - Enteropathogenic Escherichia coli STEC - Shiga toxin producing Escherichia coli

Answer 63

Enterotoxigenic Escherichia coli An E.coli that produces special toxins that stimulates the lining of the intestines causing them to secrete excessive fluid. This results in watery diarrhoea - Travellers Diarrhoea

Answer 64

LT and ST enterotoxin

Answer 65

Heat labile ETEC toxin modifies Gs protein to a 'locked on' state. Adenylate cyclase is activated - increased cAMP. increased secretion of Cl- into the intestinal lumen, H2O follows this down an osmotic gradient results in traveller's diarrhoea.

Answer 66

Enterohaemorrhagic Escherichia coli Causes bloody diarrhoea

Answer 67

Enteropathogenic Escherichia coli They lack ST and LT toxins Use adhesin called intimin to bind to host cells cause watery diarrhoea

Answer 68

S.dysenteriae S.flexneri S.boydii S.sonnei

Answer 69

It is acid tolerant and so it will not be destroyed by gastric acid

Answer 70

Via person to person contact Via contaminated food and water

Answer 71

Severe bloody diarrhoea Frequent passage of stools > 30/day small volume pus and blood in stool prostrating cramps fever

Answer 72

Shiga toxin

Answer 73

Enters through colonic M cells: In the intestine it induces self-uptake leads to macrophage apoptosis. Cytokines are released and neutrophils are attracted Causes inflammation. Shigella spread to adjacent cells.

Answer 74

Systemic absorption of shiga toxin will target the kidney Causes Haemolytic Uremic Syndrome (HUS) Can lead to kidney failure

Answer 75

Salmonella enterica Has over 2500 serovars

Answer 76

Through the ingestion of contaminated food and water

Answer 77

Gastroenteritis - Serovar Enteritidis and Typhimurium Enteric Fever -Serovar Typhimurium and Paratyphi Bacteraeima - Serovar Cholerasuis and Dublin

Answer 78

1. Invasion of gut epithelium (SI) 2. Intestinal secretory and inflammatory response: serovars Enteritidis and Typhimurium - (Does NOT produce toxins) 3. Transcytosed to basolateral membrane 4. Enters submucosal Macrophages; survive and replicate within the macrophage. 5. Systemic infection due to dissemination within macrophages: serovar Typhi

Answer 79

UTI - 30% of cases Opportunistic infection Can lead to pyelonephritis and sepsis

Answer 80

Urease Causes and increase in urine pH leads to calcium and magnesium phosphate precipitation forms kidney stones

Answer 81

Environmental - not gut It is an opportunistic pathogen and so will infect immunocompromised subjects

Answer 82

It is an opportunistic pathogen so will infect immunocompromised patients Including: Neonates Elderly Immunocompromised

Answer 83

UTIs Pneumonia Surgical wound infection Sepsis

Answer 84

It is MDR (multi-drug resistant) it is resistant to carbapenems - the most broad spectrum drugs

Answer 85

The bacteria responsible for causing cholera A facultative anaerobe notorious for causing pandemics

Answer 86

Ingestion of shellfish Contamination of drinking water - due to flooding of costal areas or poor sanitation Faecal-oral route

Answer 87

Not very transmissible like this as it is highly susceptible to acid and therefore cannot survive in the stomach for long periods

Answer 88

Voluminous watery stools (secretory diarrhoea) - rice water stools Can lose 20L of fluid/day Dehydration leads to hypovolaemic shock which causes death No blood or pus or fever - no invasion or damage to mucosa

Answer 89

Oral rehydration therapy (ORT)

Answer 90

TCP pili - required for colonisation Cholera toxin - causes Gs subunit to be locked on uncontrolled cAMP production increase PKA Increased activity of CFTR channel Loss of Cl- and Na+ Water follows and massive H2O loss

Answer 91

Ubiquitous free-living aerobe Motile - has a flagellum opportunistic Difficult to treat - MDR

Answer 92

Acute: burns/surgical wounds UTI keratitis Systemic: Sepsis ICU: Pneumonia - leading cause of pneumonia in ICU Chronic: Patients with CF

Answer 93

Exclusively human parasite opportunistic infection Fastidious - requires chocolate agar to culture non-motile

Answer 94

Nasopharyngeal carriage in 25-80% of the population

Answer 95

Meningitis - 5-10% of cases at <5yrs bronchopneumonia Epiglotitis, Sinusitis, Otitis media Bacteraemia Pneumonia in patients with CF, COPD, HIV

Answer 96

Capsule LPS

Answer 97

causes severe disease - 15-20% mortality Fastidious - cultured on charcoal agar

Answer 98

air conditioning shower heads nebulisers humidifiers

Answer 99

Legionnaires disease - severe inflammatory pneumonia

Answer 100

Aerosol transmission high contagious

Answer 101

Whooping Cough (pertussis) Caused by the Pertussis toxin

Answer 102

Non-flagellated gram negative diplococci Fastidious Obligate human pathogen

Answer 103

Neisseria meningitidis Neisseria gonorrhoea

Answer 104

Via aerosol transmission

Answer 105

In universities In barracks

Answer 106

Capuse LPS

Answer 107

Exists in the nasopharynx Crosses nasopharyngeal epithelium and enters the blood stream Can cause low level bacteraemia (asymptomatic) or full sepsis (high mortality if not treated) Can cross BBB and enter CSF or subarachnoid space Lead to invasion of the meninges (meningitis)

Answer 108

The second most common STD worldwide

Answer 109

Person to person contact only Sexually transmitted

Answer 110

Infections can be asymptomatic Gonorrhoea Urethritis - In women can lead to PID (pelvic inflammatory disease) Proctitis, gingivitis, pharyngitis Conjunctivitis

Answer 111

LPS Twitching motility pili

Answer 112

spiral rods Microaerophilic - need low O2 levels and requires CO2

Answer 113

C.jejuni C.coli

Answer 114

Most common cause of food poisoning -undercooked poultry, cattle, unpasteurised milk Causes mild to severe diarrhoea - often with blood infection is mild but can be severe in immunocompromised Px

Answer 115

Proteobacteria Microaerophilic - low O2 Spiral shaped

Answer 116

No - it is not spread but exists in the gastric mucus of roughly 50% of the global population Therefore only a fraction of people develop disease

Answer 117

Gastritis Peptic ulcer disease - causes 80-90% of ulcers Implicated in 10% of gastric adenocarcinomas and MALT lymphoma

Answer 118

Rod shaped bacili

Answer 119

Bacteroides fragilis Most common cause of anaerobic infections

Answer 120

Non motile rods obligate anaerobes Make up commensal flora of large bowel Most abundant flora - 30-40% of total flora

Answer 121

opportunistic Only occur with tissue injury - surgery, perforated appendix or ulcer

Answer 122

Round - elementary bodies Pleiomorphic - reticulate bodes Small non motile

Answer 123

Gram neg Obligate intracellular parasite

Answer 124

Unique growth cycle - 2 developmental stages 1. Elementary bodies - infectious and will enter cells via endocytosis 2. Reticulate bodies - Replicative (non-infectious), will acquire nutrients from host Reticulate bodies are converted back to elementary bodies to be release and infect other cells

Answer 125

Chlamydia: C.trachomatis Chlamydophila: C.pneumonia C.psittaci

Answer 126

Trachoma - blindness Genital tract STD - Most common STD Usually, asymptomatic Lympho-granuloma venereum (LGV)

Answer 127

Respiratory tract infection - mild pneumonia

Answer 128

Men - 10% Women - 50%

Answer 129

Spiral/helical

Answer 130

Borrelia burgdorferi - Lime diesase Treponema pallidum - Syphilis

Answer 131

Lyme disease (300 cases in UK) Spread via tick bites

Answer 132

1. Bacteria infects small mammals i.e. rodents 2. Tick larvae acquire from the rodents; transmitted to humans by nymphs. → bull's eye rash and flu-like symptoms.

Answer 133

Syphilis (STD) (2800 cases in UK)

Answer 134

In a medium containing rabbit serum

Answer 135

Primary stage: Localised infection: ulcer (chancre) that occurs days-weeks post infection; highly transmissible Secondary stage: ~50% cases: systemic - skin, lymph nodes, joins, muscles occurs 1-3months post infection; highly transmissible Tertiary stage: ~30% cases: granuloma (gummas) in bone and soft tissue: Cardiovascular syphilis: aorta Neurosyphilis: brain and spinal cord Occurs several years post infection; non-infectious stage

Answer 136

Cannot grow on cultures Detected using serology

Answer 137

A fungi that requires keratin for growth

Answer 138

- Skin infection - Good prognosis - tends to be mild but occasionally debilitating - Mucosal infection - Good prognosis - tend to be mild but occasionally debilitating - Invasive infection (including wound infection) - Poor prognosis - can be life threatening even with ideal medical care

Answer 139

Normally opportunistic

Answer 140

Dermatophytes

Answer 141

Keratin in the skin. they are associated with the epidermis as the can feed off the dead skin tissue for keratin

Answer 142

in immunocompromised patients

Answer 143

Innate - macrophages

Answer 144

Ulcerative corneal infection (also called mycotic keratitis or keratomycosis)

Answer 145

Fungus Bacteria

Answer 146

Reduced vision or blindless (second most common cause of blindness behind cataracts)

Answer 147

It is treatment resistant

Answer 148

Candida albicans Candida glabrata Candida tropicalis

Answer 149

An environmental organism

Answer 150

From spores - these are inhaled and infection occurs through the lungs (it is a conidial fungas)

Answer 151

Aspergillus fumigatus Aspergillus nidulans

Answer 152

Asthma Cystic fibrosis Sinusitis

Answer 153

In immunocompromised patients

Answer 154

A difficult to treat ongoing infection. If there is a significant underlying lung disease then this can lead to a reduced lung function making this infection difficult to clear leading to it becoming chronic.

Answer 155

Pneumocystis pneumonia

Answer 156

Pneumocystis jirovecii An obligate human parasite of the lung

Answer 157

Immunocompromised

Answer 158

In the environment

Answer 159

Cryptococcus neoformans Cryptococcus gattii Tends to only infect immunocompromised patients

Answer 160

To achieve inhibitory levels of agent at the site of infection without host cell toxicity

Answer 161

Identifying molecules with selective toxicity for organism targets

Answer 162

- Target does not exist in humans - Target is significantly different to human analogue - Drug is concentrated in organism cell with respect to humans - Increased permeability to compound - Modification of compound in organism or human cellular environment - Human cells are "rescued" from toxicity by an alternative metabolic pathways

Answer 163

Fungi have cell walls These cell walls are comprised of ergosterol

Answer 164

Polyenes Ergosterol Synthetic pathway inhibitors

Answer 165

Amphotericin - broad spectrum Nystain - Topic treatment

Answer 166

Form a pore in the ergosterol membrane 10x less affinity for cholesterol in mammalian membranes

Answer 167

Salt shifts

Answer 168

Dose dependent inhibitors of 14alpha-sterol demethylase Secondary targets in the synthetic pathway inhibited by triazoles

Answer 169

Fluconazole - Candida and Cryptococcus Itraconazole - Aspergillus Voriconazole - Invasive Aspergillus Posaconazole and Isavuconazole - Zygomycetes

Answer 170

liver dysfunction GI symptoms: 10% of patients may discontinue drugs because of it Nausea vomiting pain Diarrhoea

Answer 171

Echinocandins

Answer 172

Inhibit 1,3-beta-glucan synthase

Answer 173

Caspofungin Micafungin Anidulafungin

Answer 174

Susceptible yeasts Mould

Answer 175

Via intravenous Poor oral bioavailability

Answer 176

Mycobacteria tuberculosis Mycobacteria leprae

Answer 177

They sit with the Gram-Positive bacteria family They however do not stain on Gram stain Require Ziehl-Neelsen stain

Answer 178

The composition of their cell wall makes it impervious to staining They have a high lipid content with Mycolic acids Acid-Fast Bacteria

Answer 179

Ziehl-Neelsen

Answer 180

Mycobacteria are Non spore forming Aerobic Non motile

Answer 181

Difficult to target with antibacterial agents It allows them to survive inside macrophages at low pH environments

Answer 182

Very slow Weeks

Answer 183

Slow reproduction time Slow growth in humans - gradual onset of disease Slow growth in culture - increased time to make diagnosis Slow response to treatment - cannot target fast reproduction times like other bacteria

Answer 184

Bacterium is adapted to the intracellular environment It can withstand phagolysosomal killing and will escape into the cytosol.

Answer 185

Release microbicidal molecules to kill the bacteria They then present the antigen on MHC II molecules This is detected by CD4 T cells CD4 cells secrete IFNy andTNFa to activate intracellular macrophage killing

Answer 186

Infected macrophage in the centre Other recruited Macrophages aggregated together (aggregates of epithelioid histocytes) Surrounded by Lymphocytes (T and B cells)

Answer 187

It will wall off the bacteria However this can create a niche for the bacteria to enter latency and survive

Answer 188

Fibroblasts

Answer 189

CD4 depletion caused by HIV TNFa depletion caused by therapies against RA or organ transplant

Answer 190

Solid culture: Microscopy positive 2-4 weeks Microscopy negative 4-8 weeks Liquid culture: 1-3 weeks

Answer 191

Nucleic Acid Detection: Uses PCR based testing Faster results Can detect for resistance Sensitive and very specific

Answer 192

The Mantoux test: Intradermal injection of purified TB protein derivatives Induced swelling and redness is a positive result

Answer 193

4 Drugs: (RIPE) Rifampin - 6 months Isoniazid - 6 months Pyrazinamide - 2 months Ethambutol - 2 months

Answer 194

4-9 months of combination therapy

Answer 195

Antibiotic resistant strains

Answer 196

Side effects Hepatotoxicity Peripheral Neuropathy Optic Neuritis

Answer 197

MDR TB - resistant to multiple first line drugs EDR (extensively drug resistant) - resistant to second line drugs Totally drug resistant - TB resistant to treatment

Answer 198

Aerosol Patient to Patient Transfer

Answer 199

- Initial contact made by alveolar macrophages - Tuberculosis evades killing by macrophage - Use macrophage to get transported through the lymphatics to the hilar lymph node

Answer 200

- Primary infection contained but cell mediated immunity persists - Therefore in latent TB there is no clinical disease - But the response to TB can be measured in tuberculin skin test

Answer 201

- Failure of immune system leads to the clinical presentation of disease: - Granulomas form around bacilli that have settled in the apex of the lung - In the apex there is more air and less blood - More air for bacteria - Less blood access for white blood cells to clear infection

Answer 202

Abscess formation Necrosis occurs in the centre of the granuloma (caseous) Caseous (cheesy) material gets coughed up

Answer 203

Immediately after primary infection After latent activation

Answer 204

Other areas of the lung to create other TB lesions Other body tissues: TB meningitis Miliary TB Pleural TB Bone and joint TB Genitourinary TB

Answer 205

Age - infants, young adults, elderly Malnutrition Intensity of initial exposure Immunosuppression

Answer 206

An infectious obligate intracellular parasite Comprised of genetic material (DNA OR RNA) Surrounded by a protein coat or membrane

Answer 207

Cytomegalovirus (CMV) Varicella Zoster Virus (VZV) Herpes Simplex Virus (HSV) Rubella

Answer 208

Influenza Measles Mumps Norovirus

Answer 209

Epstein Barr Virus (EBV) - Lymphoma Hepatitis B/C - Hepatocellular Carcinoma Human Papilloma Virus (HPV) - Cervical/anal cancer HIV - Increase risk of contracting other cancer causing viruses

Answer 210

Grow inside living cells - replicate inside host machinery Possess only one type of nucleic acid - DNA OR RNA (not both) No cell wall - Have a protein coat (capsid) or membrane lipid evenlope Inert outside of host cell Protein receptors on virus surface to allow for attachment to susceptible host cells

Answer 211

Acute: Symptomatic - Chicken pox caused by VZV Asymptomatic - Herpes and CMV Chronic: Hepatitis B and C HIV Latent: Reactivation of VZV causes shingles in adulthood

Answer 212

PCR - identifies viral genetic material Serology - detection of immunological memory of a virus Histopathology - features of viral infection Viral culture Electron Microscopy

Answer 213

1. Attachment to specific receptor 2. Cell entry 3. Host cell interaction 4. Replication of viral DNA into host cell 5. Assembly of virion - Translation of viral mRNA to produce Viral genome, structural proteins and non-structural proteins 6. Release of new viral particles - viral bursting (cell death) or budding/exocytosis

Answer 214

Direct destruction of host cells Modification of host cells Over reactivity of the immune system Damage through cell proliferation Evasion of Host defenses

Answer 215

**Poliovirus:** - Infects and replicates within nerves, over 4 hours - Host neuron lysis and death - Causing paralysis

Answer 216

**Rotavirus:** - Atrophies villi and flattens epithelial cells of the gut - Decreases small intestine surface area - Nutrients (including sugar) are not absorbed - Hyperosmotic state - sugar remains in lumen so draws in water - Profuse diarrhoea **Rotavirus is resistant to acidic pH*

Answer 217

**Hepatitis B:** 1. Virus infects hepatocyctes, and cause the presentation of the viral antigen on outside the hepatocyte. 2. Cytotoxic T lymphocytes recognise the antigen as foreign and kill the hepatocyte infected with virus, leading to a reduced number of hepatocytes

Answer 218

- Jaundice (increased bilirubin) - Pale stool (increased bilirubin) - Dark urine (increased bilirubin) - Right Upper Quadrant (RUQ) pain - Fever and malaise - Itching (bile salts released into body) **Hepatitis B tends to become chronic. Sustained viral replication and liver cell destruction occurs but at a lower level, presenting fewer clinical symptoms*

Answer 219

**Human Papillomavirus (HPV):** 1. Acquired through direct contact 2. Partial viral replication and expression of HPV proteins - these are oncoproteins 3. Viral DNA integration into host chromosomes 4. Continous expression of oncoproteins (cancer causing proteins) causing cellular DNA mutations → dysplasia and neoplasia

Answer 220

1. Virus persistence or latency. 2. Down regulation of interferons. 3. Virus variability due to gene reassortment or mutation. 4. Prevention of host cell apoptosis. 5. Viral modulation of host defences.

Answer 221

- Skin **Orofacial herpes** - cold sores **Genital herpes** - warts **Herpetic whitelow** - sores on the fingers **Erythema multiforme** - systemic rash across the body **Herpes gladiatorum** - rash affecting the chest - Visceral **Oesophagitis** - inflammation of the oesophagus **Pneumonitis** - inflammation of the lungs **Hepatitis** - inflammation of the liver - CNS Meningitis - inflammation of the meninges surrounding the brain Encephalitis - inflammation of the brain Transverse myelitis - inflammation across the spinal cord (can cause paralysis, sensation changes) - Eye - Conjunctivitis - Keratitis

Answer 222

CNS - progressive multifocal leukoencephalopathy

Answer 223

Single cell eukaryotic organisms Unicellular Can be free living or parasitic

Answer 224

Based on locomotion: Amoebaoids Sporozoa Flagellates Cilliates Microsporidia

Answer 225

Entamoeba histolytica

Answer 226

Faeco-oral route

Answer 227

With Metronidazole

Answer 228

Human African Trypanosomiasis (sleeping sickness) American Trypanosomiasis (Chagas disease) Leishmaniasis Trichomoniassis Giardiasis

Answer 229

Human African Trypanosomiasis (sleeping sickness) American Trypanosomiasis (Chagas disease) Leishmaniasis Trichomoniasis Giardiasis

Answer 230

- Chancre - Fever - Headaches - Extreme fatigue - Lymphoadenopathy - Spenomegaly - CNS involvement (e.g. personality changes)

Answer 231

Vector - infected via Tsetse fly

Answer 232

Blood film or CNS

Answer 233

- Slower illness manifestations - Headache - Fever - Lymphadenopathy - Chagoma - swelling at site of innoculation - Romana's sign - swelling around the eyes, eyelids and conjunctiva - Late disease manifestations - Dilated cardiomyopathy - Megaoesophagus - Megacolon

Answer 234

Trypanosoma cruzi

Answer 235

Vector - transmitted through faeces of triatomine bug Through blood, vertical transmission and contaminated food

Answer 236

Visualisation of tropmastigotes on blood film Amastigoes on biopsy in chronic illness

Answer 237

- Cutaneous - Incubation; weeks to months - Ulcers on exposed parts of body; these heal and leaving permenant scars - Usually benign - Mucocutaneous - Partial or total destruction of mucous membranes of nose, mouth and throat cavities - Visceral - Known as Kala-Azar (black fever) - Incubation period; days to years - Associated with multi-organ failure - Associated with bone marrow suppression, lymphodenopathy, weight loss. - High mortality rat

Answer 238

Via saliva of the female sand fly

Answer 239

Diarrhoea Cramps Bloating

Answer 240

Faeco-oral route

Answer 241

Stool microscopy - presence of trophozoites

Answer 242

Metronidazole and tinidazole

Answer 243

- Purulent discharge - Abdominal pain - Vulvar/ cervical lesions - Dysuria - Dyspareunia

Answer 244

- Urethritis - Epididymitis - Prostatitis *Often asymptomatic*

Answer 245

Trichomonas vaginalis

Answer 246

Sexually Transmitted Infection (STI)

Answer 247

Metronidazole

Answer 248

Cryptosporidiosis Toxoplasmosis

Answer 249

- Watery diarrhoea (no blood) - Vomiting - Fever - Weight loss

Answer 250

Cryptosporidium spp

Answer 251

Water/ food bourne infection - occurs through the ingestion of mature cysts

Answer 252

Acid fast staining - oocysts seen in stool sample

Answer 253

- Hydration and replacement of electrolytes - Self-limiting disese - usually lasting no more than 2-3 weeks

Answer 254

- Usually asymptomatic - severe consequences in pregnancy and immunodeficiency - Disseminated disease (particualarly affecting the eyes!) - Chorioretinitis - Retinochoroiditis - Toxoplasma encephalitis

Answer 255

Toxoplasma gondii

Answer 256

*Acquired through ingestion of oocytes!* - Contaminated food - Undercooked meat and shellfish - Vertical transmission - Trasmission via water/ feline species

Answer 257

Vector; spread of Plasmodium via the bite of a female Anopheles mosquito

Answer 258

- Plasmodium falciparum (important!) - Plasmodium ovale - Plasmodium vivax - Plasmodium malariae - Plasmodium knowlesi

Answer 259

P. falciparum Responsible for 75% of malaria cases in the UK

Answer 260

Non-specific symptoms: - Fever, night sweats and rigors - Chills - Myalgia - headache - Vomiting Signs: Pallor - due to anaemia Hepatosplenomegaly Jaundice - bilirubin released due to RBC haemolysis

Answer 261

*Haemolysis due to infected cell lysis and immune-mediated killing!* - Anaemia - Jaundice - Hepatosplenomegaly - Black water fever - Hb passes into urine - Monocytosis and lymphopenia - loss of WBC response - Thrombocytopenia - reduced platelets

Answer 262

1️⃣ Parasite develops in the RBC, producing waste products and toxic factors 2️⃣ Infected cells releasing *merozoites* surface proteins and *hemozoin* into the blood 3️⃣ Stimulates macrophages to release pro-inflammatory cytokines and inflammatory mediators (TNF, IFN-y)

Answer 263

Blood film - visualisation of Trophozoite seen under light microscopy - Thick film - to detect whether person has malaria - Thin film - identify species and calculate parasitaemia percentage

Answer 264

- **Uncomplicated malaria** Oral: 1. Artemether with lumefantrine (**Riamet**) 2. Proguanil and atovaquone (**Malarone**) 3. **Quinine sulphate** 4. **Doxycycline** - **Complicated or severe malaria** IV: 1. **Artesunate:** this is the most effective treatment but is not licensed. 2. **Quinine dihydrochloride**

Answer 265

- Human Liver Stage (exo-erythrocytic): - 1️⃣ Mosquito takes a blood meal, injecting the indiviual with sporozoites (infected for of the Plamsodium) - 2️⃣ Sporozoites travel in the blood and infect liver cells (hepatocytes) - 3️⃣ Sporozoites can mature into Shizoints or lay dormant as hypnozoites (in P. vivax/ P. ovale) - 4️⃣ Shizoints mature into merozoites which enter the blood and infect RBCs - ⭕ Human Blood Stage (Endo-erythrocytic): - 5️⃣ Merozoites infect RBCs - The merozoites reproduce every 48 hours. - 6️⃣ Merozoite develop into immature trophozoite. This can then go down two maturation routes: - 7️⃣ 🅰️ Trophozoite develop into Schizonts and then merozoites, which ruptures the RBC which releases more merozoites to infect other RBCs This cycle repeats every 48 hours. - ✳️ At this stage, as RBCs rupture, the individual develops cyclical fever and haemolytic clinical manifestations, such as anaemia, jaundice (bilirubinaemia), haemoglobinuria - 7️⃣ 🅱️ Some Trophozoites differentiate into *sexual stage gametocytes*

Answer 266

Due to the replication of the merozoites in the RBCs taking 48 hours at which point the RBC ruptures leading to an inflammatory response

Answer 267

- 8️⃣ Another mosquito takes a blood meal from this infected individual will ingest *gametocytes* - 9️⃣ Gametocytes mature into an *oocyst* - 🔟 Oocysts ruptures and release *sporozoites* - 🔟+ 1️⃣ Sporozoites are injected into the blood of a different individual - cycle.

Answer 268

P. Falciparum Causes complicated malaria - P. Falciparum replicates rapidly and causes microcirculatory obstruction.

Answer 269

Uncomplicated: Most plasmodium-infected red blood cells get screened and destroyed by the spleen. Complicated: P.falciparum: Plasmodium falciparum avoids this fate by generating a sticky protein that coats the surface of the infected red blood cells. The protein causes the red blood cells to clump together and occlude tiny blood vessels - a process called cytoadherence. This blocks the flow of blood so that infected cells aren’t able to flow into the spleen, and it also blocks blood flow from reaching other vital organs which can cause ischaemia. This can eventually lead to organ failure (refer to complications).

Answer 270

- 1️⃣ Cytoadherence Infected RBCs present membrane proteins that bind to microvascular endothelial cells in vessels - 2️⃣ Rosetting Infected RBCs also adhere to non-infected RBCs, causing small vessels to become obstructed by clumbs of RBCs - this causes hypoxia. - 3️⃣ Sequestration Microinfarcts form in major organs (brain, heart, lungs, liver, kidney) where they are able to mature and evade the immune system.

Answer 271

Cerebral malaria - Anti-epileptic drugs Renal Failure - Fluids and dialysis Acute Respiratory Distress Syndrome (ARDS) - Oxygen, Diuretics and ventilation Bleeding - Blood products/Blood transfusion Shock - Sepsis treatment via Broad Spectrum antibiotics

Answer 272

P.ovale and p.vivax.

Answer 273

Chloroquine

Answer 274

Nematodes Trematodes Cestodes

Answer 275

Women more than men

Answer 276

19-24 year olds

Answer 277

HAART (Highly Active Anti-retroviral Therapy)

Answer 278

- Global target - 90% of people living with HIV should be diagnosed - 90% of people diagnosed with HIV started on anti-retroviral therapy - 90% of those on anti-retroviral therapy be viral suppressed

Answer 279

10-fold increase in risk of death within first year of diagnosis

Answer 280

- Blood Less common due to blood screening before blood transufsions - Sexual Most often through Heterosexual transmission despite stigma of homosexual transmission - Vertical Called this now instead of “Mother to child transmission” as it had connotations of blaming the mother

Answer 281

- Undetectable=Untransmissible - If the viral load is undetectable in the patient's blood, they are not able to transmit the virus, even in unprotected sex - Therefore, if you take your medication properly and keep the viral load at 0 then it is not possible to pass HIV on regardless of condom use

Answer 282

- Pre-Exposure Prophylaxis - usually take tenofovir and entricitabine in one combined tablet - Take anti-retroviral therapy despite not having HIV to prevent infection - **highly effective -** much more effective than PEP

Answer 283

- Post-Exposure Prophylaxis - Emergency medication taken after potential exposure to the virus - Must be started within 72 hours of exposure

Answer 284

- Cost-effective, testing is very cheap - Reduction in cost of social care, lost working days, benefits claimed, cost associated with further onward transmission - Gives patient access to appropriate treatment and care - Reduction of transmission

Answer 285

- Clinician indicate diagnoses - clinical indications of immunosuppressive disease - Routine screening in high prevalence locations - Antenatal screening - Screening in high risk groups - Patient initiated request for testing

Answer 286

- Unexplained lymphadenopathy - Unexplained weight loss or diarrhoea, night sweats of PUO - Oral or esophageal candidiasis or hairy leukoplakia - Flu like illness, rash, meningitis - Unexplained blood dyscrasias

Answer 287

Heterosexual and homosexual sex (men to women and men to men) IVDU Multiple sexual parteners Rape Vertical transmission

Answer 288

- Document verbal consent given - Determine how results will be given - Do not need written consent - Do not need pre-test HIV counselling

Answer 289

- Venous blood sample - 4th gen HIV tests detect vast majority of infections at 4 weeks - If there is a high degree of risk/suspicion of HIV infection repeat at 8 weeks if a negative result

Answer 290

- Point of Care Test - Finger prick of blood - Lower sensitivity and specificity - This test is used in the community to increase access to the test, increases patient choice and case detection - Lower risk of complications and transmissions associated

Answer 291

Retrovirus

Answer 292

RNA genetic material Contain a reverse transcriptase enzyme

Answer 293

Chimpanzee derived Simian Immunodeficiency virus (SIVcpz)

Answer 294

Sooty Mangabey-derived simian Immunodeficiency virus (SIVmp)

Answer 295

T-helper cells coordinates acquired immune response - responsible for organising, recruiting and facilitating maturation of B-antibody producing cells and CD8 (T-killer) cells.

Answer 296

- CTLs produce *perforin and granulysin enzyme* that directly kills cells with antigen on. - NK cells kills any cell seen to be infected with specific foreign agent.

Answer 297

Produces specific interleukins (IL-4, 5, 10 and 13) whihc causes the maturation of B lymphocytes into plasma cells - Plasma cells produce specific antibodies IgG against specific antigen - Produces a rolonged and effective antibody response

Answer 298

Icosahedral protein capsid containing 2 RNA strands 2 enzymes: integrase and reverse transcriptase Lipid envelope with spike projections of glycoproteins GP41 and GP120 to lock onto CD4 receptors on T cells

Answer 299

CD4 T cells Dendritic cells, macrophages, astrocytes

Answer 300

- 1️⃣ Glycoproteins on HIV molecule (gp160; formed of gp120 and gp41) allow it to adhere to; - CD4 receptors (gp120 and gp41 receptors) - CCR5 receptors on Macrophages -CXCR4 Receptors on CD4 T cells - 2️⃣ Once viral capsid enters cell, viral enzymes and nucleic acid are uncoated and released. - 3️⃣ Using *reverse transcriptase*, single stranded RNA is converted into double-stranded DNA. - 4️⃣ Viral DNA then is integrated into cell own DNA through the action of *integrase enzyme*. - 5️⃣ When infected cell divides the viral DNA is transcribed, producing long chains of viral proteins Whilst infected cell is replicated, the viral DNA also replicates alongside. - 6️⃣ Viral RNA is spliced and the protein chains are cleaved and reassembled by *protease enzyme* into individual proteins - these combine to form a functioning virus. - 7️⃣ The immature virus exocytosed, taking some cell membrane with it to form a new lipid envelope - 8️⃣ Once outside of the cell, the virus undergoes further maturation.

Answer 301

HIV infects CD4 T cells HIV is detectable in the bloodstream around a week after initial infection 7️⃣ Production of the HIV virus increases exponentially as more and more T-cells become infected and die as the virus replicates 8️⃣ After around three weeks after infection, the viral load and p24 antigen are detectable. the immune system responds with a full adaptive immune response to try and control the new pathogen. HIV antibody is detectable 2-4 weeks in. This is seroconversion (causing acute non-specific symptoms) 9️⃣ Immune system recovery establishes control of the virus; This starts the viral latency (asymptomatic phase) as the viral load is kept at a plateau. on average, this clinical latency period last for around seven years 🔟 Progressive immunological impairment (slow decrease in CD4 T-cells) and ongoing replication of HIV in virus reservoirs eventually leads to the clinical manifestation of immunodeficiency; HIV associated opportunistic malignancy/ infection

Answer 302

Increase viral load HIV p24 antigen detected Antibodies against HIV CD8 T cell activation Seroconversion illness

Answer 303

- Consistent condom use (80-90% effective) - Male circumcision (60% reduction in infection; no benefit to female partners) - Treating STI's e.g. genital ulcers and HSV infection which increase transmission risk - Microbicide gel for women (30-40% reduction in transmission risk) - Needle and syringe exchange for IVDUs - Post-exposure prophylaxis (PeP) - Treatment as prevention (TasP) (96% reduction) - Pre-exposure prophylaxis (PreP)

Answer 304

1. *In utero*: transplacental; mostly during the third trimester 2. *Intra partum*: exposure to maternal blood and genital secretions during delivery 3. *Breast milk*: ingestion of large amounts of contaminated milk

Answer 305

38 million

Answer 306

CD4+ T cell count/ul HIV Viral load (RNA copies/ml)

Answer 307

- Take a sexual history - Think of HIV seroconversion illness - Tell lab to check for antigen as well

Answer 308

- Recurrent shingles - Candidiasis - (Essentially infections associated with immunocompromised patients)

Answer 309

- Bacterial (often pneumococcal) pneumonia - Tuberculosis significantly higher mortaility when you have HIV and TB - Pneumocystis jirovecii pneumonia (PCP) (most common opportunistic infection in AIDs)

Answer 310

Fever SOB Dry cough Pleuritic chest pain Exertional drop in O2 saturations

Answer 311

Via Co-trimoxazole

Answer 312

- CNS Mass Lesions: - Cerebral taxoplasmosis - Primary CNS Lymphoma - Tuberculoma - Meningitis: - Cryptococcal - Tuberculous (Would have CSF with raised lymphocytes, raised protein and reduced glucose. They may also have an insidious onset CNVI palsy) - Pneumococcal - Ophthalmic Lesions: - CMV - Toxoplasmosis - Choroidal Tuberculosis

Answer 313

- Lymphoma - Caused by EBV - Cervical neoplasia - Caused by HPV - Kaposi's sarcoma - Caused by human Herpesvirus 8 - Hepatocellular Carcinoma - Caused by Hepatitis B/C

Answer 314

Acute primary infection - Acute seroconversion illness: Transient immunosuppression Fall and then rise of CD4 count. Rise of viral load Asymptomatic phase: Progressive loss of CD4 Clinical latency - may have generalised lymphadenopathy Early symptomatic HIV AIDS: Symptoms of immune deficiency

Answer 315

CD4 count less than 200/ul

Answer 316

Host and viral genetic factors Rapid onset - elderly/children, high viral load

Answer 317

Oral candidiasis- Treated with Nilstat Oral hairy leucoplakia Generalised Lymphadenopathy Shingles - Treated with Acyclovir Chronic Diarrhoea

Answer 318

CD4 <500 ul Mycobacteria Tuberculosis Kaposi Sarcoma - HHV8 Coccidiodomycosis Cervical Cancer CD4 <200 ul (the 3 Ps) Pneumocystis pneumonia Progressive multifocal Leukoencephalopathy Histoplasmosis CD4 < 100ul: (4 Cs) Candidiasis - eosophageal Cerebral Toxoplasmosis Cryptococcus Cryptosporidiosis CD4 < 50ul: CNS lymphoma CMV MAC infection

Answer 319

Abrupt onset of non-specific symptoms Significant weight loss Lethargy/depression

Answer 320

Secondary Syphilis

Answer 321

Increased transmission Increased morbidity Increased mortality

Answer 322

- Fever, rash and non-specific symptoms - Similar to glandular fever - Diffuse symmetrical maculopapular rash

Answer 323

- Oral/vaginal candidiasis/oral thrush - Oral Hairy Leukoplakia (associated with EBV) - VZV (shingles) with 2 or more episodes OR multiple dermatomes - Cervical dysplasia - Cervical carcinoma-in-situ - Peripheral neuropathy - Bacillary angiomatosis - Immune-mediated Thrombocytopaenic Purpura - Pelvic Inflammatory Disease - Listeriosis - Constitutional symptoms (i.e. fever or diarrhoea for more than 1 month) - persistent lymphadenopathy

Answer 324

Reverse transcriptase inhibitors - nucleoside/non-nucleoside Protease inhibitors Fusion inhibitors

Answer 325

2 Nucleoside reverse transcriptase inhibitors + 1 non-nucleoside reverse transcriptase inhibitor OR 2 Nucleoside reverse transcriptase inhibitors + 1 Protease inhibitor

Answer 326

These act at different points on the HIV replication cycle

Answer 327

Non adherence - not taking meds Drug-drug interactions

Answer 328

Where they work: Cell wall synthesis Nucleic acid synthesis Protein synthesis Folate synthesis

Answer 329

Bacteriostatic - Prevent the growth of bacteria; defined as a ratio of Minimum Bactericidal Concentration (MBC) : Minimum Inhibitory Concentration (MIC) of > 4 Bacteriocidal - Will kill the bacteria; kills 99.9% in 18-24 hours

Answer 330

- Inhibit protein synthesis - Inhibit DNA replication - Inhibit metabolism Useful in disease where its the bacteria exotoxin that's causing the symptoms as they reduce toxin production.

Answer 331

- Inhibit cell wall synthesis Useful in cases of poor drug penetration due to poor blood supply (endocarditis); difficult to treat infections or when we need to eradicate infections quickly (meningitis).

Answer 332

The Minimum Bactericidal Concentration (MBC) is the lowest concentration of an antibacterial agent required to **kill** a bacterium over a fixed time (18 hours or 24 hours), under a specific set of conditions. The Minimum Inhibitory Concentration (MIC) is defined as the lowest concentration of an antimicrobial ingredient or agent that is bacteriostatic (prevents the visible **growth** of bacteria)

Answer 333

If the MBC is no more than 4x the MIC

Answer 334

Concentration - How high the conc is above the MIC Time - Time that serum concentrations remain above MIC during the dose interval (t > MIC)

Answer 335

Aminoglycosides Quinolones

Answer 336

- β-lactams (penicillins; cephalosporins; carbapenems; monobactams) - Clindamycin - Macrolides - Oxazolidinones

Answer 337

Change the antibiotic target - MRSA cannot bind to PBP of staphylococci Destroy the antibiotic - Staphylococci produce beta-lactamase Prevent access of antibiotic - modify membrane channel no. size. selectivity Remove antibiotic from bacteria - Export or efflux pumps

Answer 338

Intrinsic - naturally resistant Acquired: Spontaneous gene mutations Horizontal gene transfer - Conjugation, Transduction, Transformation

Answer 339

MRSA - Methicillin (Flucloxacillin) resistant Staphylococcus Aureus VRE - Vancomycin resistant enterococci

Answer 340

Staphylococcus cassette chromosome mec (SCCmec) contains the resistant gene mecA which encodes penicillin-binding protein 2a (PDP2a). Confers resistance to all β-lactams and methicillin

Answer 341

Plasmid mediated acquisition of gene encoding altered AA on peptide chain preventing vancomycin binding - promoted by cephalosporin use.

Answer 342

Produce Beta-lactamase enzymes which hydrolise the beta-lactam ring of penicillins

Answer 343

Design drugs that utilise agents that inhibit beta lactamase Co-amoxiclav - Amoxicillin and Clavulanate Clavulanate inhibits the beta lactamase

Answer 344

A beta lactamase enzyme - extended spectrum beta lactamase Produced by some bacterial that allows them to hydrolise third gen cephalosporins and aztreonam

Answer 345

A cephalosporinase enzyme encoded by enterobacteriaceae

Answer 346

Cephalosporins, most penicillins Beta lactamase inhibitor combinations

Answer 347

Beta Lactams Glycopeptides

Answer 348

Peptidoglycan

Answer 349

Possess a Beta lactam ring - Penicillins - Cephalosporins - Carbapenems - Monobactams

Answer 350

Better on Gram positive - have bigger peptidoglycan area Can work on both Gram positive and Gram negative

Answer 351

Disrupt peptidoglycan production by: 1. Binding covalently and irreversibly to the penicillin-binding proteins (PBPs) particularly transpeptidase 2. Cell wall synthesis is disrupted and cell lysis occurs as peptidoglycan crosslinking can not occur → Active only against rapidly multiplying organisms.

Answer 352

Difference in the spectrum and activity of β-lactam antibiotics are due to their relative affinity for different PBPs

Answer 353

- Patients with penicillin allergy - Patients with meningitis as they can penetrate the head.

Answer 354

Antibiotics designed to overcome the actions of beta lactamases and cephalosporinases Therefore these are the most broad specturm antibiotics and used as a last resort

Answer 355

Ertapenem Imipenem Meropenem

Answer 356

They were the most broad spec antibiotic that could be used against anything however now there are carbapenem resistant bacteria

Answer 357

Carbapenem resistant enterobacteriaceae: Pseudomonas aeruginosa Escherichia coli Klebsiella pneumoniae

Answer 358

Gram positive bacteria so beta lactams: Cellulitis (S.aureus, Group A, C, G strep) - Flucloxacillin Strep throat (Group A,C, G strep) - PO penicillin V + IV Benzylpenicillin S.pneumonia - PO Amoxicillin + IV Benzylpenicillin

Answer 359

Vancomycin Teicoplanin

Answer 360

Only work on Gram positive bacteria: Used in MRSA Those with penicillin allergy

Answer 361

Rifampicin Metronidazole Fluoroquinolones

Answer 362

RNA polymerase

Answer 363

DNA gyrase and DNA topoisomerase IV

Answer 364

Ciprofloxacin (restricted antibiotic)

Answer 365

Gram negative > Gram positive: Penicillin allergy UTIs Intra-abdominal infections

Answer 366

Aminoglycosides - Gentamicin (30s) Tetracyclines - Doxycycline (30s) Lincosamides - Clindamycin (50S) Macrolides - Clarithromycin/ Erythromycin (50s) Chloramphenicol

Answer 367

Gram negative and Staph UTIs Infective Endocarditis

Answer 368

Broad specturm but mainly gram positive (S.aureus and Streps) Cellulitis (if penicillin allergy) Pneumonia

Answer 369

Gram Positive (S.aureus, Beta haemolytic strep and anaerobes) Cellulitis Necrotising Fasciitis

Answer 370

Gram positive (S.aureus, Beta haemolytic strep, atypical pneumonia) Severe pneumonia Penicillin allergy

Answer 371

Sulphonamides Trimethoprim

Answer 372

Broad spectrum but mainly used for Gram negative UTIs

Answer 373

1. How does it work? 2. What kind of bacteria will it cover? 3. Does it need to be IV or PO? 4. Does my patient have an infection caused by those bacteria? 5. Could there be resistance? 6. Are there any reasons why the patient couldn't have antibiotics?

Answer 374

Nitrofurantoin First line for UTI and it only works in the lower respiratory tract Trimethoprim

Answer 375

- Isolation - Antimicrobial stewardship - promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness

Answer 376

- Design (e.g. ventilation) - Cleaning - Patient isolation

Answer 377

- Handwashing - Barrier precaution (e.g. gloves, gowns, etc.) - Isolation

Answer 378

Handwashing

Answer 379

Infections caused by the patients own flora

Answer 380

Surgery Catheterisation Cannulisation

Answer 381

1-2 days before the onset of symptoms until all blisters have crusted over

Answer 382

- Immunocompromised patients - Patients who have had transplants - Adults - Pregnant people - Smokers - Infants

Answer 383

- Erythematous macule which becomes an erythematous papule - Ends in a crust

Answer 384

- Grows in warm areas of the body - Around neck and axillae

Answer 385

- Do not wipe the skin with alcohol swab - Pop lesion with a sterile needle - Absorb vesicle contents onto swab - Replace swab in casette and send for VZV/HSV PCR

Answer 386

Dehydration Haemorrhagic change cerebellar ataxia Encephalitis Varicella pneumonia Skin and soft tissue infections

Answer 387

- The virus travels along the sensory neurone axon until it reaches the dorsal root or cerebral ganglion - Here it lies dormant until reactivation - Shingles appear across single dermatomes for this reason - only 1 neurone is activated

Answer 388

Age Loss of immune response

Answer 389

After the shingles infection, the nerve endings are inflamed and causes painful stimulus The thorax

Answer 390

- 'Weird' dermatomes (where you wouldn't expect to find shingles rash) - Dissemination of the rash - Haemorrhagic changes - All suggest immunocompromised

Answer 391

Hand Foot Mouth

Answer 392

Not a danger to the foetus Supportive care - hydration and manage fever

Answer 393

Cardiomyopathy Encephalitis Join inflammation (sternomastoid joint)

Answer 394

Slapped cheeks Flushed cheeks with a reticular pattern

Answer 395

Joint aches and pains - may last weeks Prevent RBC maturation - anaemia

Answer 396

Lack of ability to produce mature RBCs can make the foetus non-viable Foetus has to receive blood via the umbilicus

Answer 397

HSV I - Mouth (Vermillion border, border of mucosa of lips and epithelium of skin) HSV II - Genitals

Answer 398

Can cause HSV encephalitis in the foetus

Answer 399

Confluent morbidiform Sparing on pressure points

Answer 400

- Cough - Coryza - Diarrhoea - Conjunctivitis

Answer 401

ACts on the 50S subunit of the ribosome to inhibt protein synthesis

Answer 402

Act on the 30S subunit of bacterial ribosomes to inhibit protein synthesis

Answer 403

Damages DNA

Answer 404

DNA topoisomers

Answer 405

RNA polymerase

Answer 406

Inhibit peptidoglycan cross linking

Answer 407

Inhibit peptidoglycan Synthesis

Answer 408

Folic acid synthesis

Answer 409

Haematuria Bladder calcifications

Answer 410

Staphylococcus Streptococcus Enterococcus

Answer 411

Corney Mikes Lister of Basic Cars: Corneybacteria Mycobacteria Listeria Bacillus Nocardia

Answer 412

CLAP: Clostridium Lactobacillus Actinomyces Propionbacterium

Answer 413

Neisseria meningitidis Neisseria gonorrhoea Haemophilia influenza E.coli Klebsiella Pseudomonas aeruginosa Morazella catarrhalis

Answer 414

A bacteria that cannot be cultured in the normal way or detected using a gram stain.

Answer 415

Legions of Psittaci MCQs Legionella pneumophilia a Chlamydia psittaci Mycoplasma pneumoniae Chlamydophila pneumoniae Q fever (coxiella)

Answer 416

Doxycycline Clindamycin Vancomycin Teicoplanin Linezolid

Answer 417

Carbapenems: meropenem imipenem

Answer 418

E.coli Klebsiella often cause UTIs

Answer 419

Start with Amoxicillin - covers streptococcus, listeria and enterococcus Swtich to co-amoxiclav - additionally covers staphylococcus, haemophilus and e.coli Switch to Tazocin to cover pseudomonas Switch to meropenem to cover ESBLs Add teicoplanin/vancomycin to cover MRSA Add clarithromycin or doxycycline to cover atypical bacteria

Answer 420

Escherichia coli

Answer 421

Staphylococcus aureus

Answer 422

Streptococcus pyogenes

Answer 423

Streptococcus pneumoniae

Answer 424

Gram positive

Answer 425

Gram positive Gram negative Anaerobic

Answer 426

Gram positive Atypical

Answer 427

Gram negative

Answer 428

Gram negative atypical

Answer 429

Anaerobic bacteria

Answer 430

Gram positive Gram negative Anaerobic Atypical

Answer 431

Gram positive

Answer 432

Flucloxacillin

Answer 433

Nitrofurantoin Trimethoprim

Answer 434

Amoxicillin

Answer 435

Phenoxymethylpenicillin

Answer 436

Protection; prevents MAC or opsonisation molecules attacking.

Answer 437

Nosocomial infection

Answer 438

An infection that originates within a hospital

Answer 439

1. Gastroenteritis. 2. Enteric fever. 3. Bacteraemia.

Answer 440

You're losing huge amounts of water which can result in hypovolemic shock and severe dehydration, this can lead to death.

Answer 441

It grows at 18 - 42°C.

Answer 442

1. Nappy rash. 2. Tinea pedis. 3. Onychomycosis (fungal nail infection).

Answer 443

Terbinafine - it reaches poorly perfused sites e.g. nails.

Answer 444

They affect the ergosterol synthetic pathway.

Answer 445

1. High first pass metabolism, bioavailability = 45%. 2. ADR's, can cause hepatitis. 3. Drug interactions due to CYP450. 4. Resistance can develop e.g. in candida.

Answer 446

A yeast. It grows in warm, moist areas and has high levels of β-D-Glucan.

Answer 447

1. Mouth. 2. Skin. 3. Vagina. 4. Urethra. 5. Large intestine.

Answer 448

A , C and G. A - S.pyogenes

Answer 449

B - S.agalactiae

Answer 450

Alpha haemolytic streptococci. Streptococci viridans - S.sanguinis, S.oralis

Answer 451

The difference in clinical manifestation can be due to variation in the plasmodia life cycle. The plasmodia life cycle has stages in the human and the mosquito.

Answer 452

Exo-erythrocytic and endo-erythrocytic stages.

Answer 453

Someone with sickle cell anaemia or thalassaemias.

Answer 454

E6 and E7.

Answer 455

GP160 binds to CD4 receptors and also CCR5 co-receptors.

Answer 456

1. Reverse transcriptase. 2. Integrase. 3. RNA polymerase. 4. Proteases.

Answer 457

Enzymes e.g. reverse transcriptase, integrase etc.

Answer 458

Macrophages also have CD4 and CCR5 receptors.

Answer 459

1. Genital tract. 2. GI tract. 3. CNS. 4. Bone marrow.

Answer 460

Phenoxymethylpenicillin. (Penicillin V)

Answer 461

Supportive therapy and advise the patient to avoid contact sport for 6 weeks in order to avoid splenic rupture.

Answer 462

1. Reddening, swelling and white patches on the tonsils. 2. Swollen lymph nodes. 3. Spleen enlargement. 4. Chills, fever. 5. Cough. 6. Sore throat. 7. Fatigue, malaise, loss of appetite, headache.

Answer 463

1. Homosexual men. 2. Heterosexual women. 3. Sex workers. 4. IV drug users. 5. Truck drivers.

Answer 464

1. Meningitis. 2. Otitis media. 3. Pharyngitis. 4. Exacerbations of COPD.

Answer 465

1. Anthrax. 2. Cholera. 3. Rabies. 4. Smallpox. 5. Yellow fever. 6. Acute encephalitis. 7. Botulism. 8. Enteric fever. 9. Leprosy. 10. Malaria.

Answer 466

1. Diptheria. 2. Measles. 3. Mumps. 4. Rubella. 5. Tetanus. 6. Whooping cough.

Answer 467

Bacillus cereus.

Answer 468

Klebsiella pneumoniae.

Answer 469

IV benzylpenicillin.

Answer 470

Cephalosporins - IV Cefotaxime.

Answer 471

Chloroquine.

Answer 472

Lowenstein Jensen medium.

Answer 473

Group B streptococci.

Answer 474

Amoxicillin Flucloxacillin Benzylpenicillin Phenoxymethylpenicillin (Penicillin V)

Answer 475

Cephalexin Cefotaxime Ceftriaxone

Answer 476

Gram positive bacteria because they have thicker cells walls for protection. Inability to synthesise their cell wall would make them vulnerable.

Answer 477

Clarithromycin Erythromycin

Answer 478

Doxycycline

Answer 479

Gentamicin Streptomycin

Answer 480

Folate synthesis inhibitors DNA Gyrase inhibitors RNA polymerase inhibitors DNA Strand breakers

Answer 481

Trimethoprim Sulphonamides Sulphamethoxazole

Answer 482

Because it will inhibit folate acid synthesis which is required for neural tube closure and therefore could cause the child to have spina bifida or anencephaly

Answer 483

Combination therapy of: Trimethoprim + Sulphamethoxazole

Answer 484

MALARIA Specifically in Africa, south America, south east Asia

Answer 485

Treating for a condition without knowing the specifics?

Answer 486

Cough Sputum production SOB Fever Lethargy Crackles on the chest

Answer 487

Streptococcus pneumoniae (50%) Haemophilus influenzae (20%) Pseudomonas - in patients with CF or bronchiectasis Staph aureus - in patients with CF

Answer 488

Atypical bacteria Legionella Chlamydia Psittaci Mycoplasma pneumoniae Chlamydydophila pneumoniae Q fever (coxiella)

Answer 489

Amoxicillin Erythromycin/Clarithromycin Doxycycline

Answer 490

Macrolides - clarithromycin Quinolones - Levofloxacin Tetracyclines - Doxycycline

Answer 491

Women due to their urethra being much shorter and therefore it is easier for the bacteria to get into the bladder

Answer 492

Infection involving the bladder causing cystitis and this can also spread up to the kidneys causing pyelonephritis.

Answer 493

Normal intestinal bacteria contaminate the urethral opening via faeces Usually E.coli

Answer 494

Dysuria (pain, stinging or burning when passing urine) Suprapubic pain or discomfort Frequency Urgency Incontinence Confusion is commonly the only symptom in older more frail patients

Answer 495

Fever is a more prominent feature than lower urinary tract infections. Loin, suprapubic or back pain. This may be bilateral or unilateral. Looking and feeling generally unwell Vomiting Loss of appetite Haematuria Renal angle tenderness on examination

Answer 496

E.coli (most common) Klebsiella Enterococcus Pseudomonas S. saprophyticus Candida albicans

Answer 497

Trimethoprim Nitrofurantoin

Answer 498

Third trimester as it is linked with haemolytic anaemia of the newborn

Answer 499

Generally safe in pregnancy but avoided in the first trimester as it can affect folic acid metabolism and synthesis.

Answer 500

An infection of the skin and soft tissues underneath.

Answer 501

Erythema Warm/hot to touch Tense Thickened Oedematous Bullae (fluid filled blisters) Golden yellow crust - indicative of S. aureus infection

Answer 502

Staphylococcus aureus Group A strep - S. pyogenes Group C strep - S. dysgalactiae

Answer 503

Choice treatment: Flucloxacillin. Clarithromycin Clindamycin Co-amoxiclav

Answer 504

Viral infections Tend to resolve without treatment over 1-3 weeks

Answer 505

Group A strep - S. pyogenes

Answer 506

Streptococcus pneumoniae

Answer 507

Via Centor Criteria A score of 3 or more gives a 40-60% probability of bacterial tonsilitis?

Answer 508

Bacterial tonsilitis indicated in a score of >3: Fever > 38 degree Celsius Tonsillar exudates Absence of cough Tender anterior cervical lymph nodes (lymphadenopathy)

Answer 509

Phenoxymethylpenicillin (Penicillin V) Co-amoxiclav Clarithromycin Doxycycline

Answer 510

It is difficult to distinguish between bacterial and viral otitis media. It presents with ear pain. Examination will reveal a bulging red tympanic membrane. If the ear drum perforates there can be discharge from the ear.

Answer 511

Amoxicillin Clarithromycin Erythromycin

Answer 512

Co-amoxiclav

Answer 513

Penicillin V Alternatives are : Clarithromycin Erythromycin Doxycycline Second line is co-amoxiclav

Answer 514

Anaerobes - Bacteriodes and clostridium E.coli Klebsiella Enterococcus Streptococcus

Answer 515

Co-amoxiclav alone Amoxicillin plus gentamicin plus metronidazole Ciprofloxacin plus metronidazole (penicillin allergy) Vancomycin plus gentamicin plus metronidazole (penicillin allergy)

Answer 516

The influenza virus is an RNA virus. There are three types: A, B and C, of which A and B are the most common. Type A has different H and N subtypes

Answer 517

H1N1 - Swine flu H5N1 - Avian flu

Answer 518

Aged 65 Young children Pregnant women Chronic health conditions such as asthma, COPD, heart failure and diabetes Healthcare workers and carers

Answer 519

Fever Coryzal symptoms Lethargy and fatigue Anorexia (loss of appetite) Muscle and joint aches Headache Dry cough Sore throat

Answer 520

Viral nasal and throat swabs PCR

Answer 521

Oseltamivir Zanamivir

Answer 522

Otitis media, sinusitis and bronchitis Viral pneumonia Secondary bacteria pneumonia Worsening of chronic health conditions such as COPD and heart failure Febrile convulsions (young children) Encephalitis

Answer 523

Acute gastritis is inflammation of the stomach and presents with nausea and vomiting. Enteritis is inflammation of the intestines and presents with diarrhoea. Gastroenteritis is inflammation all the way from the stomach to the intestines and presents with nausea, vomiting and diarrhoea.

Answer 524

Viral infection

Answer 525

Rotavirus Norovirus Adenovirus is a less common cause and presents with a more subacute diarrhoea

Answer 526

Treatment with antibiotics as this may cause HUS

Answer 527

Campylobacter jejuni

Answer 528

Abdominal cramps Diarrhoea often with blood Nausea and Vomiting Fever

Answer 529

E.coli Campylobacter jejuni Shigella Salmonella Bacillus Cereus - From reheated rice Yersinia Staphylococcus aureus Giardiasis

Answer 530

Lactose intolerance Irritable bowel syndrome Reactive arthritis Guillain–Barré syndrome

Answer 531

Antibody blood test Test for P24 antigen presence PCR testing for HIV RNA

Answer 532

CD4 T cell count (500-1200 cells/mm3 is normal range)

Answer 533

Enterococcus

Answer 534

Enterococcus: Gram positive cocci Commonly found in the GI tract and will lactose ferment.

Answer 535

Piperacillin + Tazobactam = Tazocin

Answer 536

Glycopeptides Beta Lactams Fluoroquinolones Aminoglycosides

Answer 537

Folate acid inhibitors (trimethoprim, sulphathiazole) Macrolides Lincosamides Chloramphenicol Linezolid Tetracyclines

Answer 538

Folate acid inhibitors (trimethoprim, sulphathiazole) Macrolides Lincosamides Chloramphenicol Linezolid Tetracyclines

Answer 539

Amoxicillin Co-Amoxiclav Clarithromycin Clindamycin Doxycycline Vancomycin

Answer 540

Co-Amoxiclav Gentamycin Ciprofloxacin Doxycline

Answer 541

Co-amoxiclav Clindamycin Metronidazole Doxycycline

Answer 542

Clarithromycin Ciprofloxacin Doxycycline

Answer 543

Metronidazole PO Vancomycin