JIPMER Microbiology And Immunology Solved Model Question Paper 2022

JIPMER Microbiology And Immunology Model Question Paper 2022

Question . 1. Mechanism of resistance of tetracyclines is due to:

1. Drug efflux mechanism
2. Both drug influx and drug efflux mechanisms
3. DNA methylation
4. Cell wall alteration

Answer. (2) (Both drug influx and drug efflux mechanisms)

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Tetracycline resistance is mediated by- 1. Alteration of ribosomal target, 2. Active efflux of antibiotic from the target cell, 3. Decreased drug influx into the target cell and 4.

Enzymatic inactivation.

Question. 2. Colistin is not active against:

1. Pseudomonas aeruginosa
2. Serratia
3. Klebsiella pneumoniae
4. Escherichia coli

Answer. (2) (Serratia)

Burkholderia, Proteus and Serratia are intrinsic resistant to colistin and polymyxin.

Question.3. A neonate’s blood culture grows extended-spectrum beta-lactamase (ESBL) organism.
All will be the correct empirical therapy in this situation except:

1. Piperacillin/tazobactum
2. Meropenem
3. Aztreonam
4. Cefotetan

Answer. (3) (Aztreonam)

Organisms producing ESBL enzymes (Extended spectrum β lactamases) are resistant to all penicillins and 1st, 2nd and 3rd generation cephalosporins and monobactam, however remain sensitive to carbapenems and cephamycins.

• Resistance can be overcome by use of b-lactam along with b-lactamase inhibitor (e.g. sulbactum or clavulanic acid)
• Detected by: (1) Combination disk tests (e.g. Ceftazidime + Ceftazidime-clavulanate and Cefotaxime + Cefotaxime-clavulanate) (2) molecular methods

Question.4. Allowed amount of chlorine in drinking water:

1. 2 ppm
2. 0.5 ppm
3. 1.5 ppm
4. 4 ppm

Answer. (2) (0.5 ppm)

For normal domestic use, residual chlorine levels at the point where the consumer collects water should be between 0.2 and 0.5 mg/L.

Question.5. Which of the following is secreted by TH-1 helper cells?

1. IL-1
2. IL-2
3. IL-4
4. IL-3

Answer. (2) (IL-2)

• TH-1 cells produce IL-2, IFN-γ , TNF-ß,
• TH-2 cells produce IL-4, IL-5, IL-6, IL-10

Question.6. A patient with necrotising fasciitis is treated with antibiotics and debridement. He got discharged on wound recovery. Now he came back after 10 days with diarrhoea and fever. The following are done except:

1. Continue same antibiotic
2. Stop Loperamide 2 mg
3. Metronidazole is the Drug of Choice
4. Washing hands with alcohol based hand sanitizers are superior to washing hands with soap to stop the spread of diarrhea

Answer. (1) (Continue same antibiotic)

• Most common cause of diarrhea following antibiotic therapy is Clostridium difficile infection leading to pseudomembranous colitis
• This condition is also called as antibiotic-associated diarrhea; develops following prolonged intake of broad-spectrum antibiotics.
• Management of this condition involves removal of the antibiotic, and start of specific antibiotic against C. difficile such as metronidazole or vancomycin.

Question.7. Gene responsible for semisynthetic penicillin resistance in Methicillin-resistant Staphylococcus aureus (MRSA):

1. Mec A
2. Mec B
3. Mec D
4. Mec C

Answer. (1) (Mec A)

Methicillin resistance in S. aureus is mediated by a chromosomally coded gene called mec A gene, which alters the penicillin-binding protein (PBP) present on S. aureus cell membrane to PBP-2a.

1. PBP is an essential protein needed for cell wall synthesis of bacteria. β lactam drugs bind and inhibit this protein, thereby inhibit the cell wall synthesis
2. The altered PBP2a of MRSA strains has less affinity for β-lactam antibiotics; hence,MRSA strains are resistant to all β-lactam antibiotics
3. Recently, mec C gene (coding for PBP-2c) has also been found to be associated with MRSA. However, Mec A is a better answer here as it is the most common gene associated with MRSA.

Question.8. Panton-Valentine leukocidin is produced by:

1. Staphylococcus epidermidis
2. Pseudomonas
3. Vibrio cholerae
4. Staphylococcus aureus

Answer. (4) (Staphylococcus aureus)

Leukocidins/Panton-Valentine Toxin is produced by S. aureus.

Question.9. Encrusted cystitis is caused by:

1. Corynebacterium xerosis
2. Corynebacterium urealyticum
3. Corynebacterium renale
4. Corynebacterium pseudotuberculosis

Answer. (2) (Corynebacterium urealyticum)

Corynebacterium urealyticum is a skin commensal, rarely causes urinary tract infection(pyelonephritis) and alkaline-encrusted cystitis (struvite stones in alkaline urine) in immunocompromised and renal transplant recipient.

Question.10. Elek’s gel precipitation test used for diagnosing:

1. Corynebacterium jakeium
2. Corynebacterium diphtheriae
3. Clostridium tetani
4. Clostridium perfringens

Answer. (2) (Corynebacterium diphtheriae)

Elek’s gel precipitation test used for detecting the toxigen shift potential of Corynebacterium diphtheriae.

Question.11. Which among the following is a coccobacilli is?

1. Escherichia coli
2. Listeria monocytogenes
3. Haemophilus influenzae
4. Pseudomonas aeruginosa

Answer. (3) (Haemophilus influenzae)

H. influenzae appears pleomorphic gram-negative coccobacilli.

Question.12. Which among the following is bile esculin positive and shows growth in 6.5% sodium chloride?

1. Streptococcus agalactiae
2. Streptococcus pneumoniae
3. Enterococcus faecalis
4. Streptococcus viridans

Answer. (3) (Enterococcus faecalis)

Enterococcus shows property of bile esculin positive and shows growth in 6.5% sodium chloride.

Question.13. All the following mycobacteria produces pigment except:

1. M. kansasii
2. M. simiae
3. M. avium
4. M. scrofulaceum

Answer. (3) (M. avium)

• M. avium belongs to non-chromogen group of NTM (non-tuberculous mycobacteria)
• M. kansasii and M. simiae are Photochromogens
• M. scrofulaceum is Scotochromogen

Question.14. Trans ovarian transmission is seen among:

1. Rickettsia prowazekii
2. Rickettsia rickettsii
3. Rickettsia typhi

Answer. (2) (Rickettsia rickettsii)

Trans ovarian transmission is seen in tick, mite and mosquito like Aedes.

Question.15. A 20-year female had dog bite. Now she has fever, vomiting and diarrhea. The probable agent is:

1. Veillonella
2. Capnocytophaga
3. Porphyromonas
4. Selenomonac

Answer. (2) (Capnocytophaga)

Certain species such as C. canimorsus and C. cynodegmi are commensals in mouth of dogs and are transmitted by dog bites.

Question.16. A patient who has got complete anti-rabies vaccination 2 years ago was bitten by a dog and he is bleeding. What should you do now?

1. Repeat rabies vaccination on day 0 and 3
2. Give only anti-rabies immunoglobulin
3. Repeat full vaccine schedule
4. No vaccination is warranted

Answer. (1) (Repeat rabies vaccination on day 0 and 3)

Regimen for Post-exposure prophylaxis in previously vaccinated individuals depends on the antibody titer and the severity of the wound bite.

• Severe bite or titer unknown: 3 doses are given on—0, 3, and 7 days
• Less severe bite or titer >0.5 IU/mL: 2 doses given on 0 and 3 days
• Immunoglobulins are usually not needed.

Question.17. Gold standard investigation for Zika virus:

1. PCR
2. Plaque reduction neutralization test
3. lgM antibodies
4. RT-PCR

Answer. (4) (RT-PCR)

• Reverse transcriptase PCR (RT-PCR) has been the investigation of choice for diagnosis of Zika virus infection. It can detect ZIKV RNA in blood and urine up to 5 and 7 days of onset of symptoms respectively.
• Multiplex real-time RT-PCR has been commercially available in India targeting the nonstructural 5 (NS5) region of ZIKV, non-structural protein 4 (nsP4) from CHIKV and 3′ untranslated region (3′UTR) of DENV 1–4.

Question.18. Which of the following is an amplifying host for Japanese encephalitis?

1. Pig
2. Herons
3. Horse
4. Egrets

Answer. (1) (Pig)

• Pigs are the amplifying host for Japanese encephalitis
• Cattle and buffalo may act as mosquito attractants.

Question.19. All are true about Immune reconstitution inflammatory syndrome (IRIS) except:

1. It occurs when CD4 cell count is less than 50
2. Develops after initiation of anti-retroviral therapy
3. Associated with delayed type of hypersensitivity
4. Does not require specific antimicrobial therapy for recovery

Answer. (1) (It occurs when CD4 cell count is less than 50)

IRIS (Immune reconstitution inflammatory syndrome)

• It occurs in some cases of AIDS during the recovery phase following the initiation of ART.
• As the viral load decreases, the immune system begins to recover, CD4 T cell count rapidly increases
• Which results in an exaggerated immune response to a previously acquired opportunistic infection causing an overwhelming inflammatory response, that paradoxically makes the symptoms of infection worse.

Question.20. Autoinfection is NOT seen in:

1. H. nana
2. H. diminuta
3. Strongyloidosis
4. Taenia solium

Answer. (2) (H. diminuta)

• Autoinfection refers to transmission of infection to the same person by contaminated hand (external auto-infection) or by reverse peristalsis (internal autoinfection).
• CHEST: It is observed in Cryptosporidium parvum, Hymenolepis nana, Enterobius vermicularis, Strongyloides stercoralis and Taenia solium.

Question.21. Smallest helminth among the following is:

1. Hymenolepis diminuta
2. Hymenolepis nana
3. Diphyllobothrium latum
4. Balantidium coli

Answer. (2) (Hymenolepis nana)

• Balantidium coli is a protozoa
• Other parasites in the options are helminths; among which Hymenolepis nana is the smallest.
• Hymenolepis nana is the smallest tape worm (1–4 cm) where as Diphyllobothrium is the longest cestode measuring 10 meters or more

Question.22. Tungiasis is:

1. Ecto parasite skin infection
2. Ecto parasite intestinal infection
3. Endo parasite skin infection
4. Endo parasite intestinal infection

Answer. (1) (Ecto parasite skin infection)

• Tungiasis is an ectoparasitic infestation, caused by Tunga penetrans, which is a small flea.
• It is seen in travelers returning from Latin America (largely Brazil) and Sub-Saharan Africa.
• The gravid females produce burrows on skins which ulcerate causing itching and irritation.

Question.23. A retroviral-positive patient presents with frequent diarrheal episodes. Stool examination reveals round acid-fast oocyst of size 4-6 microns. What could be the probable diagnosis?

1. Toxoplasma gondii
2. Cryptosporidium parvum
3. Coccidioides immitis
4. Sarcocystis

Answer. (2) (Cryptosporidium parvum)

• Diarrhea in HIV-positive patient may be caused by coccidian parasites such as Cryptosporidium, Cyclospora and Cystoisospora; all are acid-fast in nature.
• However, the oocyst of Cryptosporidium parvum is acid fast, round and 4–6 µm size.

Question.24. After 10 days of antibiotics patient came back again with complaints of diarrhoea.

Which of the following statement is true?

1. Alcohol-based hand rub is superior to hand washing with soap and water
2. Hand washing should be done only with clean water
3. Hand washing with hot water is superior than cold water
4. Antiseptic hand wash are better than alcohol based hand rubs

Answer. (4) (Antiseptic hand wash are better than alcohol based hand rubs)

• This is case of antibiotic-associated diarrhea; which is usually caused by Clostridium difficile.
• Alcohol-based hand rubs are ineffective for the spores of C. difficile.
• Therefore, antiseptic hand wash is recommended for hand hygiene for a diarrhea patient; which is considered superior to alcohol based hand rubs.