Microbiology Quiz on Pathogenic Bacteria

A nasopharyngeal swab (West swab) is used.

Moraxella catarrhalis should be cultured at 37°C in 5-10% CO2 conditions.

Corynebacterium diphtheriae are Gram-positive bacilli arranged in Chinese letters.

<p>Moraxella catarrhalis does not produce acid from glucose, maltose, lactose, and sucrose.</p> Signup and view all the answers

<p>The colonies are dry, greyish-white, opaque, and 'scoot' when pushed with a loop.</p> Signup and view all the answers

<p>The primary virulence factor is the production of exotoxin.</p> Signup and view all the answers

<p>Corynebacterium diphtheriae grows best on Loeffler's serum agar.</p> Signup and view all the answers

<p>Both can appear similar in initial examinations, particularly in carrier states.</p> Signup and view all the answers

<p>Diphtheria is primarily transmitted through oral droplets and physical contact.</p> Signup and view all the answers

<p>Key symptoms include sore throat, low-grade fever, and the presence of a pseudomembrane on the tonsils.</p> Signup and view all the answers

<p>Clinically, diphtheria is diagnosed based on symptoms, while laboratory confirmation involves throat or nasal swabs and virulence tests.</p> Signup and view all the answers

<p>Diphtheroids can cause urinary tract infections, bacteraemia, and osteomyelitis.</p> Signup and view all the answers

<p>Cell-mediated immunity is crucial for controlling Mycobacterium tuberculosis infections.</p> Signup and view all the answers

<p>Mycobacterium tuberculosis has a waxy cell wall rich in lipids and mycolic acids, making it impermeable to most stains.</p> Signup and view all the answers

<p>The tuberculin test and Quanti-Feron test are used for diagnosing tuberculosis.</p> Signup and view all the answers

<p>The etiological agent of pulmonary tuberculosis in humans is Mycobacterium tuberculosis.</p> Signup and view all the answers

<p>To differentiate between acid-fast bacilli and non-acid-fast bacilli.</p> Signup and view all the answers

<p>Malachite green dye and egg enrichment.</p> Signup and view all the answers

<p>It detects radioactive CO2 released when Mycobacteria utilize palmitic acid.</p> Signup and view all the answers

<p>Gram positive, non-capsulated, motile, spore-forming bacilli arranged in chains.</p> Signup and view all the answers

<p>Sputum, skin exudates, and blood.</p> Signup and view all the answers

<p>It demonstrates the polypeptide capsule of Bacillus anthracis.</p> Signup and view all the answers

<p>Differential staining technique.</p> Signup and view all the answers

<p>Pathogenic: Bacillus anthracis; Saprophytic: Bacillus cereus.</p> Signup and view all the answers

<p>Obligate aerobes can only grow in the presence of free O2, while facultative anaerobes can grow both in the presence of O2 and in its absence.</p> Signup and view all the answers

<p>Specimens should be collected using sterile techniques and by needle aspiration to minimize contamination.</p> Signup and view all the answers

<p>It should be freshly prepared, used within 2 weeks, supplemented with special nutrients, and contain reducing agents.</p> Signup and view all the answers

<p>Bacteroides and Lactobacillus are examples of non-spore forming anaerobes.</p> Signup and view all the answers

<p>Common infections include intraabdominal infections, postoperative wound infections, and lung abscesses.</p> Signup and view all the answers

<p>Dental caries is a disease caused by anaerobic Gram positive bacilli like Lactobacilli.</p> Signup and view all the answers

<p>They are typically arranged in chains.</p> Signup and view all the answers

<p>Heating or steaming at 80°C for 2 minutes expels dissolved oxygen, creating an optimal anaerobic environment.</p> Signup and view all the answers

<p>Clostridium perfringens produces β-hemolysis on blood agar.</p> Signup and view all the answers

<p>Clostridium perfringens are Gram positive bacilli, non-motile, and have subterminal spores.</p> Signup and view all the answers

<p>Gas gangrene is diagnosed by culturing a lacerated wound swab on Robertson cooked meat medium and then subculturing on Neomycin blood agar under anaerobic conditions.</p> Signup and view all the answers

<p>The lecithinase activity of Clostridium perfringens is indicated by the formation of opaque zones on egg yolk medium.</p> Signup and view all the answers

<p>A positive Nagler's reaction indicates the presence of α-toxin as the antibody inhibits activity around the streak.</p> Signup and view all the answers

<p>Clostridium perfringens slowly liquefies gelatin.</p> Signup and view all the answers

<p>Clostridium perfringens is cultured anaerobically at 37 °C for 2-3 days on media like Neomycin blood agar.</p> Signup and view all the answers

<p>Stormy clot formation in litmus milk suggests the presence of Clostridium perfringens due to its ability to coagulate milk proteins.</p> Signup and view all the answers

<p>Listeria monocytogenes is Gram positive bacilli arranged in short chains.</p> Signup and view all the answers

<p>It produces a narrow zone of beta hemolysis on blood agar.</p> Signup and view all the answers

<p>Listeria monocytogenes is catalase positive, beta hemolytic, and exhibits tumbling motility.</p> Signup and view all the answers

<p>Haemophilus influenzae is the most common cause of acute bacterial meningitis in young children.</p> Signup and view all the answers

<p>Haemophilus influenzae requires factors X and V, growing best on chocolate agar at 35-37°C.</p> Signup and view all the answers

<p>Haemophilus influenzae appears as pleomorphic, gram-negative coccobacilli.</p> Signup and view all the answers

<p>It can be identified by a direct smear showing gram positive bacilli with tumbling motility.</p> Signup and view all the answers

<p>The polysaccharide capsule of Haemophilus influenzae aids in its virulence.</p> Signup and view all the answers