Microbiology Flashcards
1
Q
One way bacteria can be classified as gram positive and gram negative. What do these terms mean?
A
Gram positive: cell walls are composed of thick peptidoglycan. They stain purple when subject to gram stain procedure.
Gram negative: Thin cell wall of peptidoglycan. Stain pink when subject to gram stain procedure as they do not retain the purple.
2
Q
Clinical implication of difference between gram neg and gram pos bacteria
A
Gram positive bacteria have a cell wall that is easier to penetrate even though it is thicker. Due to this they tend to be susceptible to more antibiotics whereas gram negative bacteria are often less susceptible.
3
Q
What is MRSA and what is its implication in healthcare?
A
Methicillin resistant staphlococcus aureus. It is a strain of bacteria with antibiotic resistance, particularly to B-lactams, gentamycin, tetracycline and erythromycin. It can cause a variety of problems in healthcare settings:
- sepsis
- pneumonia
- joint replacements which can be irreparably damaged
- surgical site infections
- death
- bloodstream infections
4
Q
A mother brings her 18 month child to General Practice complaining of having seen small white “threads” in the nappy. What is the likely cause and the most appropriate treatment?
A
Threadworms - Mebendazole
5
Q
What is the commonest condition associated with Mycobacteria? What term is used to describe these bacteria which is relevant to detecting them in the labs?
A
Tuberculosis - Acid-fast meaning they are resistant to discolouration by standard lab processes and require specific tests to be requested.
6
Q
What are the five properties of a virus?
A
- They grow only inside living cells
- They possess only one type of nucleic acid, RNA or DNA
- They have no cell wall structure but have an outer protein coat. Some viruses have a lipid envelope
- Inert outside the host cell, but carry enzymes that function inside the cell
- They have protein receptors on their surface to allow attachment to susceptible host cells
7
Q
Name three of the ways that viruses can cause disease
A
- Damage by direct destruction of host cells
- Damage by modification of host cell structure or function
- Damage involving ‘over-reactivity’ of the host as a response to infection
- Damage through cell proliferation and cell immortalisation
- Evasion of both extracellular and intracellular host defences
8
Q
What viral vaccine has been introduced to the UK programmme and what cancer is it designed to prevent?
A
HPV given to all girls’ routine vaccines designed to protect against cervical cancer
9
Q
What is the commonest causative organism in fungal nail infection? Name three other possible differential diagnoses of fungal nail infection.
A
Trichophyton rubrum - dermatophyte is the commonest type.
Other differential diagnoses include: Psoriasis, Lichen planus, Trauma, Eczema, Yellow nail syndrome, Periungual squamous cell carcinoma/Bowens disease
10
Q
A patient presents with fever and recent travel overseas to Africa. What protozoal illness should be top of your differential diagnosis and what is the key diagnostic test?
A
Malaria. Blood test with giemsa stain.
11
Q
Summarise what an antibiotic is and how it works
A
An antibiotic is medication which stops or inhibits the growth of microorganisms (bacteria). They do this by binding a target site on the bacteria. Target sites are defined as points of biochemical reaction crucial to the survival of the bacterium and these sites will vary with the antibiotic class and bacterium.
12
Q
Give four possible clinical situations that might indicate a need for an HIV test
A
- Prolonged episodes of herpes simplex
- Persistent frequently recurrent candidiasis
- Recurrent infections
- Oral candida
- Indicators of immune dysfunction
- Odd looking mouth lesions
- New onset abnormal skin lesions (Kaposi’s sarcoma)
In summary suspect in any medical condition that is recurrent, severe or unexplained.
13
Q
Difference between gram neg and gram pos bacteria
A
Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane so they stain purple
Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane so they stain pink
14
Q
Name a catalase pos and catalyse neg aerobic, gram positive cocci
A
Catalase pos = staphylococcus
Catalase neg = enterococcus and streptococcus
15
Q
What are the 3 ways in which bacterial genetic variation occurs?
A
Transformation: horizontal gene transfer where bacteria take genetic material from environment
Transduction: requires bacteriophage to inject DNA into bacterial cell
Conjugation: transfer of plasmid through pilus transferring info from one bacteria to another
16
Q
What bacteria am I describing?
- Gram positive
- Cocci
- Blood agar shows golden colonies
- Non-motile and non spore forming
- Catalase positive so they foam up when hydrogen peroxidase is applied
A
Stpahylococcus aureus
17
Q
If S. aureus invades the epidermis what condition can be caused?
A
Impetigo
18
Q
If S. aureus invades the dermis what condition can be caused?
A
Cellulitis
19
Q
How does s aureus infection in the blood stream lead to sepsis?
A
Infection into the bloodstream = septic thrombophlebitis (infected blood clot) which can lead to bacteremia → widespread immune reaction → blood vessels → hypotension and poor perfusion to organs → SEPSIS.
20
Q
How can S aureus affect the heart?
A
Infection into heart = causes clumps called vegetation which damage the heart valves → infective endocarditis
21
Q
How can S aureus affect the CNS?
A
Infection into CNS = bacterial meningitis or epidural abscess in the spine
22
Q
How can s aureus affect the lungs?
A
Infection into lungs = severe pneumonia
23
Q
When treating MRSA, which antibiotics are chosen?
A
clindamycin or vancomycin
24
Q
What are strains of s aureus with complete resistance called?
A
VRSA
25
Which bacteria am I describing?
- cocci
- live on epidermis of skin and part of normal flora
- gram positive
- catalase positive
- urease positive (turn urea agar broth and phenol red into pink)
- coagulase negative so fibrinogen won't break down and clump
Staphyloccocus epidermidis
26
What bacteria is the most dominant bacteria on the skin and colonises the nose, scalp, face, axilla?
S epidermidis
27
Which bacteria is a common cause of prosthetic valve endocarditis and prosthetic joint infections?
S epidermidis
28
Treatment for an infected prosthetic joint with s epidermidis?
vancomycin with rifampicin can be added and infected device removed
29
What bacteria is the causative agent of strep pharyngitis, scarlet fever, impetigo and necrotising fasciitis?
Streptococcus pyogenes
30
Diagnosis of s pyogenes?
rapid strep test for throat infections
| definitive cultures from affected site
31
treatment for s pyogenes?
penicillin G
| ceftriaxone alternative
32
what is a complication of strep throat/pharyngitis?
Following pharyngitis there may be acute rheumatic fever due to M protein that mimic the structure of proteins which make up tissues in the body (myosin of heart muscle and smooth muscle cells). The immune system then activates a type II hypersensitivity reaction releasing IgM and IgG antibodies aimed at destroying the M protein but instead attack the heart muscle (myocarditis, heart valves and causing infective endocarditis or pericarditis)
33
what is post-streptococcal glomerulonephritis? What are the signs?
- Complication causing acute inflammation of the kidneys' glomeruli commonly seen after impetigo about 2 weeks post infection due to a type III hypersensitivity reaction
- Facial oedema
- Dark red urine because glomerular damage allows RBC's to pass into the urine
34
What is the most common infection that strep pneumoniae causes? What other infections can it cause?
Pneumonia
Others
- meningitis
- pneumococcal endocarditis
- septic arthritis
- rhinosinusitits
- otitis media
35
What role does the spleen play in immunity?
the spleen plays an important role in fighting against encapsulated organisms and therefore, those with spleen problems, will be more susceptible to these types of infections
36
What bacteria would you suspect to be the causative agent in food poisoning where food has been cooked in big batches and kept warm for a long time such as in buffets?
Clostridium perfringens
- these bacteria thrive in anaerobic conditions so when they are exposed to oxygen they form spores and when conditions are right, they develop into bacteria again (such as when cooling foods or storing them) and can cause food poisoning
37
These symptoms are suggestive of what condition?
- abdominal cramping
- watery diarrhoea
- vomiting
Symptoms improve within a day
Food poisoning
38
Treatment for food poisoning?
Usually no abx, treatment focuses on keeping hydrated
39
Clostridium botulism can cause what syndrome in babies? What food is thought to be a potential vector for transmitting this bacteria to babies?
Floppy baby syndrome where it causes botulism and causes a flaccid paralysis.
Honey is thought to be a vector so should be avoided in the first 12m of life.
40
Which bacteria am I describing?
- gram positive bacilli
- forms spores
- thrives in deep compact soil
- produces toxins which affect the nervous system causing muscle spasm and rigidity
Clostridium tetani
41
What is the tetanic triad?
1. locked jaw
2. risus sardonicus (facial muscle spasm causing grin)
3. opisthotonos (severe spasm of all muscles in body simultaneously)
42
Treatment for tetanus?
Tetanus immune globulin - anti-toxin that binds to circulating tetanospasmin
- muscle relaxants
- pain meds
- supportive measures
- tetanus vaccine for prevention
43
Which bacteria am I describing
- gram negative (stains pink)
- rod shaped
- encapsulated
- anaerobe
- catalase positive (foams when hydrogen peroxide is added to colony)
- lactose fermenting (turns phenol into yellow)
- when cultivated on eosin methylene blue agar it grows into black colonies with greenish-black metallic sheen
E coli
44
STEC (EHEC) causes what characteristic sign when someone is infected?
bloody, watery diarrhoea
45
Does ETEC cause bloody diarrhoea or watery diarrhoea?
Watery diarrhoea
46
Uropathogenic E coli (UPEC) causes 90% of what infection?
Causes 90% of community acquired UTIs and 50% of hospital acquired UTIs
47
What condition are these symptoms a sign of?
- high sustained fever
- abdo pain
- constipation followed by diarrhoea
- rose coloured spots on chest and abdomen
- hepatomegaly and splenomegaly as infection spreads
- dehydration, weakness, headaches and confused mental state
Typhoid fever
48
What is the 3rd most common causative agent of UTI and can also cause pneumonia? what type of urinary stones are formed by this bacteria and why?
Klebsiella pneumoniae
Causes struvite stones as klebsiella use urease to convert urea into ammonia and CO2 and this can combine and form ammonium which increases urine pH (more alkaline). Alkaline urine promotes precipitation of phosphate, calcium and magnesium which can combine to form struvite stones.
49
The symptoms described below are of which condition which can be caused by klebsiella?
- high fever
- chest pain
- chills
- SOB
- productive cough with blood-tinged sputum
Lobar pneumonia
50
these symptoms are characteristic of which condition
- dysuria
- urinary frequency
- urinary urgency
UTI
51
these symptoms are characteristic of which condition
- flank pain
- fever
- nausea or vomiting
pyelonephritis
52
these symptoms are characteristic of which condition
- fever
- chills
- swollen, tender prostate on palpation
prostatitis
53
how is shigella transmitted?
faecal to oral (contaminated water, flies, water, sexual contact)
54
If shiga toxin reaches the mucosal cells lining blood vessels, it can damage them allowing toxin to enter blood stream causing what condition?
What can then happen once the infection is in the blood stream?
Haemolytic uremic syndrome
From the bloodstream, shiga toxin can enter the kidneys and bind to the endothelial cells lining the glomerulus making them apoptose = protein leaks through causing proteinuria.
Damage to the endothelial cell causes clotting using a high number of platelets and therefore, thrombocytopenia.
Clots obstruct the small arterioles and cause fragmented RBC (schistocytes) and destruction causes anaemia.
Reduced blood supply to organs such as kidneys lead to build up of urea (blood not being filtered properly) and leads to uraemia.
Triad: haemolytic anaemia, kidney failure, thrombocytopenia.
55
Where is legionella commonly found? How is it commonly transmitted?
hot water tanks, cooling towers, large air conditioning systems and hot tubs
Transmission: inhaling infected aerosols
56
These symptoms are a sign of which disease?
- severe pneumonia
- high fevers
- GI upset
- neurological symptoms (headache and confusion)
Legionnaires disease
57
Identification of Legionella?
| Treatment?
Cultures from respiratory tract secretions
Urinary antigen test detect legionella lipopolysaccharide antigen in urine
Treatment: azithromycin
58
H pylori is found in the stomach of what percentage of the population?
50%
59
Is H pylori gram neg or gram pos curved rod?
gram neg curved rod
60
Which cells in the stomach secrete hydrochloric acid?
- chief cells
- parietal cells
- G cells
- foveolar cells
Parietal cells
chief cells secrete pepsinogen to digest proteins and G cells secrete gastrin which stimulates parietal cells among other things. foveolar cells secrete mucus
61
How is h pylori spread?
faecal oral, gastro-oral and oral-oral transmission from one infected person to another (contaminated food, water or direct contact with faecal matter, vomit or saliva)
62
Explain how h pylori causes infection in the stomach and can cause gastric ulcers.
- When H pylori reaches the stomach, it uses it's flagella to propel towards the stomach lining and usually travel to places like the antrum where there are less parietal cells and therefore, lower pH
- Adhesin proteins are used to stick to the surface of foveolar cells where it can release a number of virulence factors which help it both survive and thrive, and cause damage to the mucosa.
- One of the most important enzymes for their survival is aurease because it converts urea in the gastric juices to carbon dioxide and ammonia. Ammonia, which is basic, locally neutralises the acidic gastric environment and protects H. pylori from the harsh, acidic environment of the stomach.
- H pylori does not itself go into the epithelial cells but some virulence factors it secretes do and these cause extensive damage to epithelial cells interfering with the mucus layer and increases the risk of gastric ulceration and cancers
63
What is of concern with H pylori infection and ulceration besides the higher risk of gastric cancers?
Erosion through the duodenum and into the underlying blood vessels causing perforation.
64
In a lot of patients, h pylori infection does not cause symptoms. In those who do get symptoms, what sort of things do they experience?
Heartburn
SOB
Loss of appetite with or without weight loss
Pain in the abdomen above the stomach which worsens a few hours after eating
If erosion = bleeding and blood in vomit or stools
Air can collect under the diaphragm if there is perforation and can lead to irritation of the phrenic nerve causing referred pain to the shoulder
Chronic infection can also cause iron deficiency anaemia as the bacteria sequester iron
65
How can we diagnose h pylori?
faecal antigen test
urease breath test
Blood titres
Biopsy from upper GI endoscopy
66
How do we treat h pylori infection?
Triple therapy using 2 antibiotics (amoxicillin and clarithromycin) and a PPI (omeprazole)
67
What gram negative rod shaped organism is the most common cause of bacterial gastroenteritis worldwide? Where is it commonly found?
Campylobacter jejuni
commonly found in poultry and unpasteurised milk - children at risk as there is a risk of spread from direct contact with infected pets
68
Infection with which bacteria is the most common risk factor for GBS?
Campylobacter jejuni
69
Describe the microbiology of Neisseria meningitidis. What test do we use to distinguish between N meningitidis and N gonorrhoea?
- Gram negative - stains pink
- Round bacterium
- N meningitidis typically lives in pairs - diplococci
- Non motile
- Non spore forming
- Obligate aerobes (they need O2 to survive)
- Catalase and oxidase positive
Use maltose test to distinguish - NM causes solution to go yellow, NG makes the solution stay red.
70
diagnosis of n meningitidis
blood cultures
| lumbar puncture for CSF analysis and culture
71
treatment of meningitis?
treatment for close contacts?
prevention?
Prompt administration of Ceftriaxone.
Following results of antibiogram → can be switched to Penicillin G
Prophylactic ceftriaxone, rifampin or ciprofloxacin should be given to close contacts of affected individual
Vaccinate high risk individuals
72
How is N gonorrhoea commonly transmitted? If the infection spreads up the Cervix and into uterus and Fallopian tubes in a woman, what complication could it cause?
Sexual contact
| Can cause pelvic inflammatory disease
73
If gonorrhoea infects a pregnant woman, what can the baby be born with?
Early neonatal conjunctivitis
74
Symptoms of gonorrhoea infection in men and women?
| What can occur if the infection spreads to the joints?
Can be asymptomatic in up to 50% of women
Females = thick, white, purulent discharge from vagina or urethra which can turn bloody and urethritis. Can cause inflammation of Fallopian tubes.
Men = Burning sensation when peeing, clear urethral discharge which can become purulent and bloody
Can cause gonococcal arthritis where joints become painful, swelling of wrists, ankles and elbows.
75
How do we diagnose gonorrhoea?
Treatment?
Prevention?
Vaginal or urethral swab sent for gram stain and biochem tests
Nucleic acid amplification can also be done to reveal bacteria
Treatment: ceftriaxone
Prevention: condoms during sex
76
What are the 2 major forms of fungal infection?
Skin infection - ring worm
| Mucosal infection - usually female genital or mouth and easy to treat but beware of repeated infections
77
Name 2 common fungal skin infections
Athletes foot
| Ring worm
78
What are 2 things we can focus on targeting in anti-fungal treatments to make them effective?
Fungal cells have cell walls which humans dont and their plasma membrane is made of ergosterol rather than cholesterol that we have so we mainly focus on these things to target fungi.
79
What 2 drug groups have we got for fungal infections?
Azoles
| Echinocandins - choice for severe candida infection
80
What is the most common causative agent of fungal nail?
| How is it treated?
Trichophyton rubrum
Treatment is difficult, main therapy is systemic itraconzaole or terbinafine (take a long time to work - few months) and have high failure rates.
81
Mycobacteria are slow growing, gram positive, immobile bacteria and due to their special staining characteristics under the microscope, they are know as?
Acid-fast
82
What infective organism remains to be the single biggest infectious killer worldwide?
M tuberculosis
83
Why do 90% of people with TB not know they have it?
TB remains dormant in the body and when a patient becomes immunocompromised or older, the bacteria can re-appear and cause disease.
84
In terms of microbiology, what are M tuberculosis like?
| shape, aerobe or anaerobe, motility, spores, staining
```
curved, rod shaped beaded bacilli
Strict aerobes
non-spore forming
Non motile
Waxy cell wall so don't dye = acid fast positive using Ziehl Neelson stain
Very slow generation time
```
85
How is TB transmitted?
Usually from patients with active, infectious pulmonary TB
| Via droplets in air (coughing or sneezing) and entry into the lungs
86
Why can TB survive in the lungs
- When in the lung, there is initial contact made with alveolar macrophages and macrophages engulf TB bacilli which the bacilli use to proliferate
- In the macrophage, bacilli are trafficked to a phagolysosome which has hydrolytic enzymes to create a very acidic environment which would typically kill bacteria. TB however, can resist fusion with the lysosome which allows the bacterium to survive and proliferate and create localised infection
87
A few weeks after primary infection with TB, cell mediated immunity begins and form a granuloma around the site of infection to seal it off. This leads to the death of the inside cells known as?
Caseous necrosis
88
In TB, the triad of hilar lymph node involvement, granulomas and caseating necrosis is known as?
Primary complex formation
89
What can we use to detect latent TB?
TB skin test
90
What is the leading cause of death in those living with HIV?
TB infection
91
How do we diagnose TB?
Nucleic acid detection is the hallmark testing for TB endemic countries
Mantoux TB skin test - does not differentiate between active and latent TB, CXR used to look for active TB
92
Treatment for TB?
Isoniazid, rifampicin, pyrazinamide and ethambutol and treatment times are long as they have a lipid rich cell wall which is hard to penetrate.
Resistance to TB drugs is becoming a problem
93
Name some viruses which are linked to cancers
EBV - glandular fever and lymphoma
Hep B/C - hepatocellular carcinoma
HPV - cervical and anal cancer
94
What are the 5 things needed for viruses to replicate?
```
Attachment
Cell entry
Host cell interaction and replication
Assembly of virus
Release of new virus particles
```
95
How do viruses cause disease? (5)
1. direct destruction of host cells - polio
2. modification of host cell - rotavirus changing villi etc in SI causing diarrhoea
3. over-reactivity of the immune system (hep B infecting hepatocytes)
4. damage through cell proliferation (HPV)
5. evasion of immune response - staying latent in the body VZV for example or antigenic variability like influenza & HIV
96
What is the pre-patent period in relation to worm infections?
The interval between infection and the appearance of eggs in the stool.
97
What are the 3 groups of helminths?
Nematodes - round worms
Trematodes - flat worms
Cestodes - tape worms
98
What is the only common helminth in the UK? What is their appearance, transmission, clinical presentation, diagnosis and treatment?
Threadworm
They have a white, threadlike appearance
Transmission: faeco-oral route when threadworms are ingested
Clinical presentation
- Pruritis ani - very itchy around the perianal region typically worse at night time
- Commonly affects whole families
- Appendicitis
- Vaginal penetration
Diagnosis and treatment
- Microscopy of sellotape strip applied to perianal region first thing in the morning and observed for eggs.
- Drugs - mebensazole and hygiene measures
- Treat whole family simultaneously
99
What condition can be passed on through the tsetse fly bite and is usually seen in the tropics?
Sleeping sickness - African trypanosomiasis
| Causes flu like symptoms, CNS involvement, cognitive impairment
100
how is giardiasis usually spread, symptoms, diagnosis and treatment?
face-oral spread from non-drinking water
causes diarrhoea, cramps, bloating and flatulence
diagnosis by finding it in stools
treated with metronidazole
101
how is entamoeba histolytica spread? how can it present?
faeco-oral by contaminated water supplies (more common in LEDC's) can present with bloody stools
102
How is malaria spread?
| Which species of malaria is the most fatal?
Bite of female anopheles mosquito
| Plasmodium falciparum is most likely to be fatal and require hospitalisation (SE Asia and Africa)
103
How do we diagnose malaria? What are the symptoms and signs?
Blood film - found inside RBCs
Malaria Symptoms
- FEVER
- May also have chills, headache, myalgia, fatigue, diarrhoea, vomiting, abdo pain
Malaria Signs
- Anaemia
- Jaundice
- Hepatosplenomegaly
- Black water fever - blood in urine causing black coloured urine
104
Describe the malaria cycle
1. Mosquito bites and takes blood meal
- release of sporozoites in the salivary glands
2. These sporozoites enter the human which goes to the liver cell to infect it - ABDO PAIN
3. Schizonts are relased from the liver cells and these enter the RBC's
4. Trophozoites feed on the RBC and grow and more schizonts are formed releasing the schizonts which infect more RBC - cyclic fever, haemolytic, anaemia, jaundice and haemoglobinuria
105
Treatment for malaria?
Complicated malaria = IV artesunate, supportive measures
106
What are the targets for the 4 different classes of antibiotics?
1. Cell wall synthesis
2. Nucleic Acid synthesis
3. Protein synthesis
4. Folate synthesis
107
How do beta-lactam antibiotics work? give examples of beta lactic antibiotics why are beta lactic antibiotics more effective in gram positive bacteria?
- All of these antibiotics target peptidoglycan (much bigger in gram positive so more effective).
- Beta lactam antibiotics bind to peptidoglycan layer in bacteria and disrupt the peptidoylgycan production causing cell wall disruption
- This results in a hypo-osmotic or iso-osmotic environment which stops the cell carrying out it's normal function
- As the peptidoglycan layer is thicker in gram positive bacteria, the Beta lactams are much more effective in treatment of gram-positive bacteria.
- Additionally, gram-negative have additional lipopolysaccarhide layer that decreases antibiotic penetration
Examples: penicillins, cephalosporins, carbapenems
108
Give an example of antibiotics which target nucleic acid synthesis
rifampicin
metronidazole
fluoroquinolone
109
Difference between bacteriostatic and bactericidal antibiotics?
Bacteriostatic: prevents growth of bacteria killing 90% within 24h by. inhibiting protein synthesis, DNA replication or metabolism
Bactericidal: kill all bacteria inhibiting cell wall synthesis
110
What is the Minimum Inhibitory Concentration of an antibiotic?
The concentration of antibiotic needed to stop the bacteria growing.
111
What are the 2 major determinants of antibacterial effects?
Concentration - how high above the MIC
| Time - time that the antibiotic remains on the binding sites for
112
Difference between intrinsic and acquired antibiotic resistance
Intrinsic: inherent features of the bacteria such as mycoplasma being resistant to b-lactams and glycopeptides because they don't have a peptidoglycan cell wall
Acquired: when a previously susceptible bacteria are no longer susceptible to an antibiotic due to spontaneous mutation or horizontal gene transfer
113
What is an important gram positive resistant micro-organism?
MRSA (resistance to all beta lactase in addition to methicillin) and VRE (resistance to vancomycin)
114
How do we manage patients in a hospital at risk of CRE or CPE?
Keep them in a side room and monitor their gut microbiota for CPE and CRE, need a few negative rectal swabs to be negative for them to be clear
115
What are the consequences of antibiotic resistance? (3)
1. increased mortality
2. increased morbidity
3. increased cost (length of stay, more expensive newer drugs)
116
what are some factors to consider when deciding if an abx is safe to prescribe?
- Intolerance / Allergy / Anaphylaxis
- Side effects
- Age
- Renal and liver function
- Pregnancy and breast feeding
- Drug interactions
- Risk of C Diff - causing severe diarrhoea because of broad spectrum abx
117
How do beta-lactams work? Which type of bacteria do they work best against and why?
They target the peptidoglycan cell wall. They work best against gram positive as gram pos have very thick peptidoglycan cell walls whereas gram neg do not.
118
What is the first line treatment for skin and soft tissue infection caused by s aureus, group A,C,G strep?
Flucloxacillin
119
First line treatment for bacterial tonsillitis caused by group a,c,g strep?
PO penicillin V or IV benzylpenicillin
120
What can we use to treat staph MRSA infection?
Glycopeptides - vancomycin IV
121
In terms of UTIs, when do we send a culture?
| What's the first line treatment for lower UTI?
Only send culture if we think the person is at risk of having a resistant strain of bacteria or if they are pregnant.
First line: nitrofurantoin 100mg for 3 days women, 7 days men.
