Week 6&7 - Clinical microbiology/Infection Flashcards

1
Q

What is a bacterostatic antibiotic?

A

Suppresses growth, doesn’t produce sterilisation of infected site. requires additional factors. Immune mediated killing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is antibiotic spectrum?

A

The range of bacterial species effectively treated by an antibiotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are Beta-lactamases?

A

Enzymes that lyse and inactivate beta-lactam drugs. secreted by gram - ve or S.aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do beta-lactamase inhibitors work?

A

They have weak antibacterial activity, but they bind beta-lactamase allowing beta-lactam to work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some mechanisms of horizontal gene transfer/Extrinsic mechanisms of resistance?

A

Conjugation (pilus)
Tranformation (short, fragmented, naked DNA)
Tranduction (bacteriophage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some non-genetic mechanisms of resistance?

A

Change cell wall permeability
Produce active enzymes to destroy drug
Infect sites where antibiotics cant act
Alter structural target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What might cause Red man syndrome?

A

Injecting Vancomycin too quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the antibiotics C.diff is resistant to?

A
4 C's
Clindamycin
Cephalosporins
Ciprofloxacin
Co-amoxiclav
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define Sepsis.

A

Life threatening organ dysfunction due to a dysregulated host response to infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does Clindamycin do?

A

Protein synthesis inhibitor. 50s ribosome

Effective at stopping exotoxin production. Given in addition in gram +ve toxic mediated infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is antimicrobial resistance?

A

Occurs when microorganisms such as bacteria, viruses, fungi or parasites change in such a way that renders the medication used to clear the infection the microbe causes, ineffective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is intrinsic resistance?

A

Innate ability of the bacteria to resist the activity of a antimicrobial agent, through inherent structural or functional characteristics allowing tolerance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is antibiotic stewardship?

A

Systemic approach to safe and effective use of antibiotic. to optimise outcome and minimise harm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What may tetracycline cause if used in pregnancy?

A

Bone and teeth abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What may Trimethoprim cause if used in pregnancy?

A

Neural tube defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What may nitrofurantoin cause if used in pregnancy?

A

Haemolytic anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What may aminoglycosides cause if used in pregnancy?

A

Otoxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What Signs might make you think its an infection?

A

Shiver, sweats, fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How would you tell if the pharyngitis is bacterial or viral?

A

Viral has nasal symtoms bacterial doesn’t.

Bacteria has a swollen uvula, white spots on tonsils and a grey furry tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is Norovirus most commonly spread?

A

Contaminated hands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why can’s viruses like norovirus be cultured?

A

Immunity from them only lasts 6-14 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What virus commonly causes outbreaks in paediatric hospital ward?

A

Rotavirus (incubation 1-3days)

Via respiratory droplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What type of vaccine is the rotavirus vaccine?

A

Live attenuated vaccine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is Community acquired pneumonia?

A

A result of lung infection by microorganisms and the immune system’s response to the infection
Strep. pneumonia, haemphilus influenza
Mycoplasma pneumonia, legoniella pneumonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What clinical assessment is used in pneumonia?
CURB65 Confusion, urea >7, resp >30, BP d<60, s<90, age > 65 To determine if septic - SIRS and qSOFA
26
What is the clinical triad in Meningitis?
Fever Nuchal rigidity Altered mental status Photophobia, headache, purpuric rash (non-blanching)
27
What prophylaxis is used in meningitis?
Ciprofloxacin or Rifampicin
28
What treatment would you use for mycobacterium tuberculosis infection?
Rifampicin (6 months) - orange- red urine Isoniazid (6 months). - Neuropathy Ethambutol (2 months) - optic neuritis Pyrazinamide (2months) - gout
29
How would you treat Syphilis?
Benzathine penicillin
30
What is the criteria for SIRS? (2 or more)
Temp >38 or <36 WCC >12 or <4 x10^9/L Tachycardia >90 Tachyopnoea >20
31
Give examples of alpha-haemolytic strep.
Strep pneumonia, strep viridans
32
Give examples of Beta haemolytic strep
Group A strep (strep pyogens) Group B strep (strep agalactiae) Group D strep (enterococcus)
33
What does breakpoint mean?
Concentration of antibiotic which defines a species as sensitive or resistant
34
What is the clinical definition of resistance?
When infection is highly unlikely to respond, even to the maximum dose of antibiotics
35
Give an example of a Extended spectrum beta lactamase.
Cefotaximase
36
How would you treat extended spectrum beta lactamase?
Carbapenems
37
What types of infection does Carbapenemase resistant enterobactericeae cause?
(CRE is gram -ve) | Pneumonia, UTI, bacteaemia, wound infection
38
What is the key difference between clindamycin and Macrolides.
Clindamycin has no action agains aerobic gram -ve or atypical. It has excellent activity against anaerobes
39
What are the toxic effects of Chloramphenicol?
Bone marrow suppression, aplastic anaemia, optic neuritis
40
What is the first choice of antibiotic used in streptococcus infection?
Benzylpenicllin
41
What is pneomocystitis Jiroveci pneumonia?
Opportunistic infection, caused by a fungal infection in immunocompromised individuals. An EC pathogen causing interstitial plasma cell pneumonia with foamy exudate in alveoli. SoB, fever, dry cough, failure to respond to antibiotics Co-trimoxazole and steroid therapy
42
What is HIV viral load?
Measure of HIV RNA In the plasma. | Can use it to monitor response to antiretrovirals
43
What treatment is available for influenza?
Neuraminidase inhibitors - Oseltamivir (PO) or Zanamivir (INH) 2X daily for 5 days M2 inhibitors - amantadine, Rimantadine
44
What bacteria causes Syphilis?
``` Treponema pallidum (gram -ve spirochete) Tx - Benzathine penicillin ```
45
What is HIV brain disease?
Consequence of unrecognised, untreated infection and marked immunodeficiency
46
What is Neutropenic fever?
Single oral temp of 38.3 or a temp of >38, sustained for more than 1 hour in a neutropenic patient
47
What infections might occur after a solid organ transplant?
Community acquired pathogen - Penumococcus, salmonella, influenza, RSV Opportunistic - aspergillus, pneumocystis Donor derived- salmonella, HIV, TB, E.coli, syphilis Nosocomical infection - CDAD Reactivaton of infections - HSV, CMV, M.TB
48
What are the different populations of cells in TB?
Actively growing - Isoniazid Semi-dormant killed by acid environment - Pyrazinamide Semi-dormant with spurts of active metabolism - Rifampicin Completely dormant
49
What are some clinical complications of infection with the gram -ve bacilli, vibrio cholera?
Profound fluid loss and dehydration: | Hypokalaemia, metabolic acidosis. hypovolaemic shock, cardiac failure
50
What type of anaerobic, spore forming gram positive bacilli produces a heat labile protein neurotoxin?
Clostridium botulinum Foodborne botulism: pre-formed toxin in food. absorbed toxins spread via blood stream and enter peripheral nerves
51
What gram positive coccobacilli might affect pregnant women?
Listeria monocytogenes | Present with severe infection - meningitis or septicaemia
52
What are complications of the common cold?
(Viral infection of the upper respiratory tract- Rhinovirus or coronavirus) Otitis media or sinusitis
53
What antibiotic is used in treating Gonorrhoea (Nesseria gonorrhoea)
Ceftriaxone IM
54
What antibiotic would you use after a positive NAAT test for Chlamydia trachomatis?
Doxycycline
55
What treatment would you start if someone had multi-drug resistant TB?
``` Pyrazinamide + 4 2nd line Fluoroquinolone Injectable - Amikacin or kanamycin Ethionamide Cycloserine ```
56
Define septic arthritis
Inflammation of the synovial membrane of the joint, with effusion into the joint capsule due to infection.
57
What are the 4 causes of malaria?
Plasmodium falciparum (severe malaria) Plasmodium vivax Plasmodium ovale Plasmodium malariae
58
List some AIDS defining Illnesses
Penumocystic jiriveci pneumonia, invasive cervical cancer, CMV, PML caused by JC virus, lymphoma, PCP, TB
59
What would you use first line to treat MRSA?
IV vancomycin If cant try Teicoplanin
60
What are some adverse effects of beta lactamases?
Hypersensitivity, haemolysis, seizures, infection
61
What are some SE of trimethoprim?
Hyperkalaemia, raised serum creatinine, rash
62
What antibiotic might you give if you have a gram positive toxin mediated disease like NF or Toxic shock syndrome?
Clindamycin
63
What antibiotic could you use for multidrug resistant bacteria?
Carbapenem
64
If SIRS is confirmed, what test could you perform to confirm sepsis?
qSOFA - quick sequential organ failure assessment | Confusion, hypotension, tachypnoea
65
What might long term use to Metronidazole cause?
Peripheral neuropathy
66
What are some causes of pneumonia?
Typical - strep pneumonia. Haemophilus influenza, moraxella catarrhalis Atypical (malaise, myalgia, headache) - Legionella pneumonia (neurological Sx, urinary antigen test), mycoplasma pneumonia, chlamydophila pneumonia
67
What test can you perform to examine for nuchal rigidity?
Brudzinski sign - spontaneous flexion of the hips when the neck is flexed passively Also Kernig sign which is reluctance to allow full extension of the knee when hip flexed at 90
68
List some risk factors for Strep pneumonia Bacterial meningitis?
head injury, middle ear disease, 70% have an underlying disorder, neurosurgery, alcohol, immunosuppression
69
Give some contra-indications for a lumbar puncture
``` Infection at the LP site Reduced GCS Coagulopathy Seizures, sepsis Papilloedema ```
70
What might the JC virus cause?
Progressive multifocal leukencaphalopathy | - progressive motor dysfunction
71
What might toxoplasma gondii cause?
intra-cerebral toxoplasmosis | headache, seizures, focal CNS signs
72
What are some triggers for meningitis?
Infection - HSV, N. meningitis AI disease e.g. lupus Adverse drug reactions
73
What may be present on a TB histology?
Ceaseating granuloma
74
Constitutional Sx are really important in the presentation of TB, list some.
Night sweats, fever and chills, fatigue, lymphadenopathy, loss of appetite, weight loss
75
What tests might you perform to test for TB? | m.tb - mycolic acids, mannose-capped LAM is a major immune stimulator during infection
Mantoux- tuberculin skin test Interfernon gamma release assay sputum >/= 3 with one early morning sample Acid fast bacilli on Ziehl-Neelsen stain
76
What clinical signs may indicate malaria?
Jaundice, anaemia, renal impairment, hepatosplenomagely Severe malaria - shock, acidosis, pulmonary oedema, seizures
77
How would you treat Enteric fever?
Quinolones, cephalosporins, azithromycin
78
Campylobacter can cause inflammation, ulceration and bleeding of the small and large bowel due to bacteria invasion. how would you treat?
1. Fluid replacement 2. Macrolides - severe and persistent 3. Ciprofloxacin or gentamicin for invasive
79
Where does shigella act? S. sonnei, S. boydii, S. flexneri, S. dysenteriae initially watery diarrhoea - bloody
Attaches to and colonises the mucosal epithelium of the terminal ileum and colon. Produces a protein exotoxin (shiva toxin) damaging intestinal ep and glomerular endothelium - renal failure - HUS