Microbiology

Question 1

This cytokine is known to be released during viral infections to increase resistance of uninfected cells against invading pathogen. A recombinant form of it is included as one of the WHO SOLIDARITY trial investigation drugs for COVID-19

Answer 1

Interleukin-6

Question 2

With regards antigen presentation, MHC class I molecules usually present peptides derived from _____ compartment, whereas MHC class II molecules usually present peptides derived from _____ compartment.

Answer 2

Intracellular; extracellular

Question 3

Defining cytokine of TH2 differentiation

Answer 3

IL-4

Question 4

Type of Transplant Rejection - Preformed donor antibodies are directed against host antigens

Answer 4

Hyperacute rejection

Question 5

Tinea nigra. The etiologic agent of this is

Answer 5

Hortaea (Phaeoannellomyces) werneckii

Question 6

“big foot” with draining sinuses

black granules are coming out of the sinuses

Answer 6

Mycetoma

Madurella grisea

Question 7

Host structures is the implicated SARS-CoV-2 entry receptor

Answer 7

Angiotensin-converting enzyme II

Question 8

Genetic transfer involving mobilization of genes through bacteriophage

Answer 8

Transduction

Question 9

commonly employed sterilizing temperature used for laboratories for sterilizing culture media, liquids, and surgical instruments

Answer 9

121 deg C for 15 minutes

Question 10

Emerging disease- animal carrier

SARS:
H1N1:
MERS:
COVID-19:

Answer 10

SARS: Bats
H1N1: Pigs
MERS: Dromedary camels
COVID-19: Bats

Question 11

What virulence factor may be considered primarily responsible for the development of cellulitis, beginning from a small furuncle

Answer 11

Hyaluronidases

Question 12

What is the most frequent cause of Ascaris-related bowel obstruction?

Answer 12

Multiple worms forming a large bolus, resulting in mechanical obstruction of the bowel lumen

Question 13

The adult stage of which parasite is described to have attenuated anterior portion and a fleshy posterior portion?

Answer 13

Trichuris trichiura

Question 14

Which adult nematode is larviparous, which means it produces larva rather than ova?

Answer 14

Trichinella spiralis

Question 15

Chronic cough of one month. Sputum culture reveals colonies first observed after two weeks of incubation. The colonies appear rough, dry, and buff colored. What is the most likely organism?

Answer 15

Mycobacterium tuberculosis

Question 16

What is the reason behind the satellite growth of Haemophilus influenzae around colonies of Staphylococcus aureus on blood agar

Answer 16

Supply of factor V

Question 17

Also known as McClung-Toabe agar, this agar serves as a differential medium useful in the detection of lecithinase activity such as in Clostidium perfringens

Answer 17

Egg yolk agar

Question 18

Which profile correctly describes the biological activities of this tetanospasmin when treated with formaldehyde?

Answer 18

(-) neurotoxicity, (+) antigenicity

Question 19

Which is the usual site of GABHS replication in scarlet fever?

Answer 19

Pharynx

Question 20

Gram positive rod, cold, narrow zone of B hemolysis

Answer 20

Listeria monocytogenes

Question 21

Multinucleated Warthin-Finkeldey cells pathognomonic of rubeola are formed due to the production of a viral protein similarly expressed by which virus

Answer 21

Parainfluenza

Question 22

multifunctional protein encoded by the Hepadnavirus genome that is thought to play an important role in carcinogenesis?

Answer 22

HBx

Question 23

According to the WHO, which is the most common life- threatening opportunistic infection affecting people living with HIV?

Answer 23

Tuberculosis

Question 24

only prokaryotes with sterols in their
cytoplasmic membrane, but they do not synthesize their own
sterols

Answer 24

Mycoplasma sp.

Question 25

It lacks a cell wall but has 70S ribosomes.

Answer 25

Mycoplasma species

Question 26

Toxins of enterotoxic Gram-negative bacteria are transferred outside of the cell by:

Answer 26

Protein secretion systems

Question 27

What rapid test commonly used on Gram-negative rods rules out Enterobacteriaceae if positive?

Answer 27

Oxidase

Question 28

aerobic, filamentous gram positive rods with aerial hyphae

Answer 28

Nocardia

Question 29

Which virulence factor is most important in colonization and maintenance of Pseudomonas in the lungs

Answer 29

Polysaccharide slime

Question 30

What primarily differentiates bacterial cells from fungal cells?

Answer 30

Smaller size and absence of a nuclear membrane

Question 31

The most common cause of congenital infections

Answer 31

CMV

Question 32

Which serological marker should be monitored to determine if | the blood contains the infectious virus?

Answer 32

HBeag

Question 33

How is Clonorchis sinensis (Chinese liver fluke) most likely transmitted to humans?

Answer 33

Fish ingestion

Question 34

What organism (besides Trypanosoma brucei) is noted for its antigenic variation that leads to its ability to repeatedly re-infect the same person and cause disease and has led to difficulty in vaccine development? Estimates of number of different serotypes are well over 1 million.

Answer 34

Neisseria gonorrhoeae