Multiple Choice Questions in Microbiology and Infection

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Multiple Choice Questions in Microbiology and Infection		Enter Your Answers Here	Check Your Answers Here
1	Triple vaccine for the prevention of virus infections protects against:		A1
	A. mumps virus B. coxsackie virus C. measles virus D. rubella virus E. adenoviruses B. there is no effective vaccine against coxsackie viruses E. there is no effective vaccine against adenoviruses		True False True True False
2	Advantages of sterilisation by ionising radiation include		A2
	A. short sterilisation time B. reliability of sterilisation C. negligible rise in temperature D. ability to sterilise equipment made of heat-sensitive materials, e.g. polystyrene E. no deleterious effects on glassware or textile fibres B. for appropriate articles under controlled conditions E. discoloration of glassware and loss of tensile strength in textile fibres		True True True True False
3	Tetanus toxoid		A3
	A. need not be given for superficial wounds B. is given three times to babies as a component of triple vaccine C. confers passive immunity D. should be avoided in the immunocompromised person E. administration within the last five years obviates the need to give anti-biotics in a case of tetanus-prone injury A. in susceptible individuals even superficial wounds may result in tetanus D. tetanus toxoid is not a live vaccine and is safe in the immuno-compromised E. antibiotics may be necessary to prevent other infections in con-taminated wounds		False True False False False
4	Ethylene oxide is commonly used for the sterilisation of		A4
	A. fibre-optic endoscopes B. glassware C. rubber tubings and catheters D. prosthetic cardiac valves E. respiratory ventilators A. though effective, the process of sterilisation with ethylene oxide is too long for routine use by endoscopy units B. glassware is effectively and cheaply sterilised in the autoclave C. expensive non-disposable heat-labile articles may be sterilised by this method E. heat-labile components may be sterilised by this method		False False True True True
5	Enterococcus faecalis is		A5
	A. a frequent cause of pyogenic infections B. a Gram-negative coccus C. usually sensitive to aminoglycosides D. often resistant to cephalosporin antibiotics E. associated with infection in hip prostheses A. though it may occasionally cause intra-abdominal sepsis B. they are Gram-positive cocci in short chains C. MIC (minimum inhibitory concentration) against amino-glycosides is high and this organism would normally be considered to be resistant to aminoglycosides, but these antibiotics are some-times used to treat infections with this organism in combination with penicillins because of synergistic action E. though coagulase-negative staphylococcal species are the most common cause of infection in hip prostheses, enterococci are also significant pathogens in this situation		False False False True True
6	Methicillin-resistant Staphylococcus aureus (MRSA)		A6
	A. is usually sensitive to vancomycin B. is more likely to cause deep-seated infection C. is often resistant to many antistaphylococcal antibiotics D. may cause asymptomatic colonisation E. may be phage-typed for epidemiological purposes B. is no more likely to cause deep-seated infections than ordinary Staphylococcus aureus strains D. many patients and staff exposed to MRSA may be colonised asymptomatically in the nose, axillae and groins E. but other typing systems such as pulsed field gel electrophoresis may be more discriminating than phage typing in investigating the epidemiology of outbreaks.		True False True True True
7	Aminoglycoside antibiotics such as gentamicin		A7
	A. act on the bacterial cell wall B. are active against staphylococci C. are effective in the treatment of anaerobic myositis D. are contra-indicated in patients with renal impairment E. may cause loss of visual acuity in the elderly A. act on ribosomes, so interfere with protein synthesis B. though some strains may be resistant C. have no activity against anaerobic organisms D. can be used with caution and close monitoring of blood levels E. neurotoxicity is to the vestibular and cochlear branches of the eighth cranial nerve		False True False False False
8	In bacterial endocarditis		A8
	A. blood cultures may be negative B. staphylococci are rare causative organisms C. the inability to control infection with antibiotic therapy is an indication for replacement of the affected valve D. combination therapy with a penicillin and an aminoglycoside is advised in most cases E. cystoscopy is a predisposing factor A. some cases may be due to organisms such as Coxiella, Chlamydia and Legionella, which are difficult to culture on routine blood culture media B. staphylococci are often the cause of endocarditis, especially on prosthetic valves D. combination therapy is advised in cases where the causative organism is a streptococcus, enterococcus or staphylococcus, i.e. the vast majority of cases. E. particularly when infections are caused by enterococci		True False True True True
9	Epididymo-orchitis		A9
	A. is associated with prostatitis B. is a complication of gonococcal urethritis C. is a manifestation of genital infection with Ureaplasma spp D. occasionally complicates mumps E. may be caused by Mycobacterium tuberculosis D. predominantly orchitis E. predominantly epididymitis		True True False True True
10	The antistreptolysin O titre is raised in infections caused by		A10
	A. Streptococcus sanguis B. Streptococcus pneumoniae C. Streptococcus pyogenes D. Streptococcus bovis E. Streptococcus mutans		False False True False False
11	The following are causes of gas gangrene in man		A11
	A. Clostridium histolyticum B. Clostridium septicum C. Clostridium novyi D. Clostridium sporogenes E. Clostridium perfringens		True True True False True
12	The haemolytic uraemic syndrome		A12
	A. is more common in children B. in the majority of cases is caused by infection with verotoxin-producing Escherichia coli C. is rarely associated with haemorrhagic colitis D. is caused by an infective agent that may be transmitted with food E. may present as an acute abdomen B. the most common strain of verotoxin-producing Escherichia coli is O-157, but other serotypes of Escherichia coli may also produce the toxin C. is commonly associated with colitis and bloody diarrhoea; this is the usual presentation in adults D. but it is often difficult to isolate the organism from the food E. haemorrhagic colitis with passage of blood and mucus and abdominal pain may occasionally be mistaken for a surgical emergency		True True False True True
13	In tuberculous infection of the urinary tract		A13
	A. the renal pelvis is most commonly affected B. nephrectomy is usually necessary in addition to antituberculous chemotherapy C. the demonstration of acid-fast bacilli in an early morning sample of urine is usually diagnostic D. sterile pyuria is a consistent laboratory finding E. Mycobacterium tuberculosis is the species most commonly involved B. standard antituberculous chemotherapy is usually sufficient C. urine samples often contain contaminating non-pathogenic Mycobacteria spp E. though in the past Mycobacterium bovis was also common; atypical mycobacterial species rarely cause renal infection		True False False True True
14	The diagnosis of pseudomembranous colitis (PMC) is aided by		A14
	A. colonoscopic biopsy of lesions B. positive blood culture for Clostridium difficile C. raised antibody levels in blood to Clostridium difficile toxin D. isolation of Clostridium difficile from the stool E. detection of Clostridium difficile toxin in the stool A. histology is pathognomonic B. Clostridium difficile infection is not bacteraemic C. antibody tests on blood are not of value in clinical diagnosis because infection and toxin secretion are confined to the colonic lumen D. but Clostridium difficile can also be isolated from the stool in some normal individuals, particularly children and the elderly E. but Clostridium difficile toxin may also be present in the stool in some normal individuals		True False False True True