121. Endotoxins are produced by________________?
A. Fungi
B. Gram +ve bacteria
C. Virus
D. Gram -ve bacteria
✅ The correct answer is option Gram -ve bacteria.
Microbiology MCQs
122. Which organism causes prosthetic valve endocarditis within 60 days of surgery________________?
A. Streptococcus Viridans
B. Staphylococcus epidermis
C. Staphylococcus aureus
D. Fungus
✅ The correct answer is option Staphylococcus epidermis.
123. One of the following statement about statements about sterilization is not true_______________?
A. Liquid paraffin → Dry heat
B. Glass syringes → Boiling at 169°C for 60 min
C. Flash pasteurization of milk → 72° C for 15 seconds, followed quickly by rapid cooling to 13°C for lower
D. Vaccines → Ethylene oxide
✅ The correct answer is option Vaccines → Ethylene oxide.
124. Pathogenic treponemas can be maintained in________________?
A. Tissue culture
B. Chick embryos
C. Artificial media
D. Rabbit testis only
✅ The correct answer is option Rabbit testis only.
125. The HIV virus can be destroyed invitro by which of the following_____________?
A. Boiling
B. Ethanol
C. Cidex
D. All of the above
✅ The correct answer is option All of the above.
126. All are true about widel test except________________________?
A. Base lines differ depending on the endemicity of the disease
B. O antibodiest last longer and hence is not indicative of recent infection
C. H antigen cannot differentiate between subtypes
D. High titre value in a single widal test is not confirmative
✅ The correct answer is option O antibodiest last longer and hence is not indicative of recent infection.
127. CD4 cells recognize the antigens in association with_____________?
A. MHC I
B. MHC II
C. MHC III
D. B-cell receptor
✅ The correct answer is option MHC II.
128. The medium of choice for culturing yeast from of dimorphic fungi is_________________?
A. Brain – heart infusion
B. Sabouraud’s
C. Sabouraud’s plus antibiotics
D. Any medium incubated at 35-37°C
✅ The correct answer is option Sabouraud’s plus antibiotics.
129. L.D bodies are seen in_______________?
A. Kalahazar
B. Toxoplasmosis
C. Malaria
D. Sleeping sickness
✅ The correct answer is option Kalahazar.
130. Which worm is longest________________?
A. T. Solium
B. T. Saginata
C. Hook worm
D. A. Lumbricoides
✅ The correct answer is option T. Saginata.