Mycobacteria Tuberculosis MCQs

Ranke Complex is formed when the primary complex gets calcified. Ghon focus refers to the initial nodular cavitations. When these involve hilar lymph nodes, it is called primary complex. Simon focus is the hematogenous seeding of apex of the lung in post primary TB. reactivated Simon focus with central caseation is called Assman's focus. Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 625

The given clinical features, along with sterile pyuria in urinalysis raises a suspicion of genitourinary TB. It is seen when tubercular bacilli are disseminated hematogenously. It is diagnosed by collecting 3 early morning urine samples and processing them via culture in MGIT or LJ media or Genexpert Radiology may show strictures or perinephric abscesses. It is treated well with ATT Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 752

Mycolic acid layer is the principal constituent of the mycobacterial cell wall, made up of long chain fatty acids attached to arabinogalactan. It confers very low permeability to the cell wall and is responsible for acid fastness. Lipoarabinomannan facilitates the survival of tubercle bacilli within the macrophages. It is also used as a target antigen for the TB diagnosis. Peptidoglycan maintains the shape and rigidity of the cell. Lipopolysaccharide is found in gram negative bacteria. Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 624

Ans. Pulmonary hamartoma Popcorn calcification o Popcorn calcification is a cluster of sharply defined, irregularly lobulated, calcification, usually in a pulmonary nodule. o Popcorn calcification is characteristic of hamartoma on chest X-ray examination. o It may also be seen in mediastinal lymph nodes of acute histoplasmosis. Egg-shell calcification o Egg-shell calcification means peripheral rim calcification of lymph nodes: o It is seen in: N Silicosis (most common cause) (vi) Histoplasmosis (vii) Tuberculosis (ii) Coal worker pneumoconiosis (v) Sarcoidosis (viii) Coccidiodomycosis (iii) Lymphoma following radiotherapy (vi) Progressive massive fibrosis

All mycobacteria are obligate aerobes except M Bovis, which is microaerophilic Reference: Essentials of Medical Microbiology, byApurba Sastry and Sandhya Bhat, 3rd edition, page 23

The concentration of phenol in carbol fuschin is increased in the Kinyoun's method. It is also called the cold method as heating is not required. This method doesn't use fluorescent dyes. However, fluorescent staining with auramine rhodamine stains can also be done wherein the bacilli appear as brilliant yellow against a dark background. Reference : Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 628

In India, WHO recommended Danish 1331 strain of BCG is used. BCG is available in lyophilized form, and should be reconstituted before administration. This is done by using normal saline as diluent. Distilled water is never used as it is irritant. Once reconstituted; it has to be administered within 1 hour Administration of BCG:0.1 mL (0.1 mg TU) of BCG vaccine is administered above the insertion of left deltoid by intradermal route, using a 26 gauge tuberculin syringe. BCG is directly given to the newborn soon after birth. If not given at birth it can be given later, maximum up to 2 years. Edmonston Zagreb strain is used in measles vaccine Oka strain is used in chicken pox vaccine SA 14-14-4 is used in JE vaccine Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 635

Normal CD4 count is 400/µL. Extremely low count of CD4+ T cells associated with Oral thrush is characteristic of HIV/AIDS. None of the other choices would be associated with this finding. Respiratory difficulties due to infection are frequently seen in HIV/AIDS patients. HIV weakens the immune system, increasing the risk of TB in people with HIV. HIV-TB coinfection is very common. Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 10th Edition, Chapter 19, Page Number 187-190.