MDS PREP
The period from disease initiation to disease detection in non-infectious disease is called -
1. Incubation period
2. Serial interval
3. Latent period
4. Lag time
Microbiology
Answer: 3
Incubation period: This term is typically used for
infectious diseases and refers to the time between exposure to the
infectious agent and the onset of symptoms.
Serial interval: This refers to the time between
successive cases in a chain of transmission, specifically in infectious
diseases.
Latent period: This is the time from the initiation of
the disease process (or exposure to a risk factor) until the disease is
detectable or until symptoms appear. In non-infectious diseases, this period
can be significant, as the disease may be developing without any noticeable
symptoms.
Lag time: This term can refer to various delays in
processes but is not specifically defined in the context of disease
initiation and detection.
Which of the following is NOT a characteristic of anthracoid bacilli?
1) Generally motile
2) Non-capsulated
3) Grow in long chains
4) Pathogenic to laboratory animals
Anthracoid bacilli are generally non-motile and non-capsulated, and they do not grow in long chains.
What is the primary clinical significance of a deficiency in C5 to C8 components of the complement system?
1) Hereditary angioneurotic edema
2) Recurrent pyogenic infections
3) Systemic lupus erythematosus
4) Neisserial infections
Recurrent pyogenic infections are associated with a deficiency in C5 to C8 components of the complement system.
Most bacterial endotoxins are composed of
1. pure carbohydrates
2. mucoprotein complexes
3. pure lipids
4. lipoprotein-polysaccharide complexes
Microbiology
Answer: 4
Most bacterial endotoxins are composed of lipoprotein-polysaccharide complexes
On a medium containing 6% agar, 5% Fildes peptic digest of sheep blood, and 20% human serum, which of the following is NOT a typical characteristic of C1. Perfringens colonies?
1) They will be surrounded by a zone of opacity on the half without antitoxin due to the Nagler reaction
2) They are nonmotile
3) They are capsulated
4) They ferment lactose and produce bright pink colonies on MacConkey’s medium
General Microbiology Answer: 2
C1. Perfringens colonies are typically nonmotile and do not form capsules. They will be surrounded by a zone of opacity on the half without antitoxin due to the Nagler reaction (option 1) and will not ferment lactose to produce bright pink colonies on MacConkey’s medium
The most pronounced effect on the oral microflora of a reduction in rate of salivary flow is a
1. significant increase in number of oral bacteria
2. shift towards a more acidogenic microflora
3 significant decrease in number of oral bacteria
4 shift towards a more aerobic micro flora
Microbiology
Answer: 2
The most pronounced effect on the oral microflora of a reduction in rate of salivary flow is a shift towards a more acidogenic microflora
In concentrations usually applied for sterilization purposes, ethylene oxide is preferable to formaldehyde becuase it is
1. more readily polymerized to an active form
2. less toxic
3. less likely to form an explosive mixture with air
4. more penetrating
Microbiology
Answer: 4
In concentrations usually applied for sterilization purposes, ethylene oxide is preferable to formaldehyde becuase it is more penetrating
What is the typical biochemical profile of E. coli on the IMViC test series?
1) Indole positive, Methyl red positive, Voges-Proskauer positive, Citrate positive
2) Indole positive, Methyl red positive, Voges-Proskauer negative, Citrate positive
3) Indole positive, Methyl red negative, Voges-Proskauer positive, Citrate negative
4) Indole positive, Methyl red negative, Voges-Proskauer negative, Citrate positive
General Microbiology Answer: 3
The IMViC test series is used to differentiate members of the Enterobacteriaceae family, including E. coli. E. coli typically has an indole positive (indole is produced when tryptophan is metabolized), methyl red positive (indicating the ability to ferment glucose and produce acid), Voges-Proskauer positive (produces acetoin from glucose), and citrate negative (does not utilize citrate as a sole carbon source) biochemical profile. This profile helps distinguish it from other related bacteria like Proteus and Klebsiella species.