Staphylococcus and Micrococcus Quiz

They are fastidious, requiring CO2, hemin, or menadione for growth and form small colonies with 1/10 the size of wild type strains after 48 hours.

Aureus appears as spherical cells that can be found singly, in pairs, or in clusters.

Aureus colonies appear creamy, white, or light gold, typically measuring 4mm-8mm, with a buttery texture.

<p>Aureus is not lysed by lysostaphin, while S. saprophyticus is sensitive and lysed by it.</p> Signup and view all the answers

<p>B-hemolytic aureus strains can exhibit antibiotic resistance, complicating treatment and requiring susceptibility testing.</p> Signup and view all the answers

<p>Staph lutrae and Staph agnetis.</p> Signup and view all the answers

<p>It is Gram-positive, spherical, and mostly arranged in irregular grape-like clusters.</p> Signup and view all the answers

<p>It is the major structural component of the cell wall and is important for pathogenesis.</p> Signup and view all the answers

<p>Marked hemolysis.</p> Signup and view all the answers

<p>Mac Conkey agar.</p> Signup and view all the answers

<p>20-25% CO2 concentration.</p> Signup and view all the answers

<p>Protein A.</p> Signup and view all the answers

<p>Pink colonies.</p> Signup and view all the answers

<p>The optimum temperature is 37°C.</p> Signup and view all the answers

<p>It occurs primarily in newborns and previously healthy children.</p> Signup and view all the answers

<p>The colonies are large, circular, smooth, shiny, opaque, and easily emulsifiable.</p> Signup and view all the answers

<p>This pH range is optimal for the growth of the bacteria responsible for the condition.</p> Signup and view all the answers

<p>TSS is associated with women who use tampons.</p> Signup and view all the answers

<p>The epidermolytic toxin contributes to the symptoms of extensive exfoliative dermatitis.</p> Signup and view all the answers

<p>The nutrient slope has an oil paint appearance.</p> Signup and view all the answers

<p>The bacteria produce a yellow pigment that does not diffuse into the medium.</p> Signup and view all the answers

<p>The slide method screens for catalase positive colonies and detects cell-bound coagulase.</p> Signup and view all the answers

<p>Hemolysin causes anemia by destroying red blood cells and making iron available for microbial growth.</p> Signup and view all the answers

<p>The four types are alpha-hemolysin (destroys RBCs), beta-hemolysin (destroys sphingomyelin), and gamma-hemolysin (less toxic).</p> Signup and view all the answers

<p>Beta-hemolysin shows enhanced activity on incubation at 35°C, destroying RBCs around nerves.</p> Signup and view all the answers

<p>Inoculate a tube with plasma and incubate it at 35°C; a positive result indicates clot or coagulum formation.</p> Signup and view all the answers

<p>The tube should be left at room temperature for an additional 20 hours of incubation.</p> Signup and view all the answers

<p>Coagulase production helps to suppress phagocytosis and increases bacterial virulence in infections.</p> Signup and view all the answers

<p>Staphylococcus lugdunensis and Staphylococcus schleiferi are other slide coagulase positive organisms.</p> Signup and view all the answers

<p>Mannitol salt agar is used as a selective and differential medium to identify MRSA by facilitating the fermentation of mannitol, resulting in yellow-colored colonies.</p> Signup and view all the answers

<p>The mecA gene encodes for the altered penicillin binding protein PBP2a or PBP2’, which gives MRSA its resistance.</p> Signup and view all the answers

<p>Prolonged hospital stays and close contact with infected individuals.</p> Signup and view all the answers

<p>The mecA gene.</p> Signup and view all the answers

<p>A positive Chromogenic test shows a color change in MRSA colonies on CHROM agar, distinguishing them from non-MRSA colonies.</p> Signup and view all the answers

<p>MRSA typically produces yellow colonies on mannitol salt agar, whereas some strains of S.saprophyticus may also ferment mannitol but do not show a color change.</p> Signup and view all the answers

<p>Infective endocarditis and nosocomial bacteremia.</p> Signup and view all the answers

<p>Secretion of poly-gamma-DL-glutamic acid.</p> Signup and view all the answers

<p>The Durham tube is used to detect gas production by microorganisms, which can indicate fermentation activity.</p> Signup and view all the answers

<p>Staphylococcus saprophyticus is novobiocin resistant.</p> Signup and view all the answers

<p>They are classified as MRSA due to their resistance to oxacillin, indicating an altered cell wall structure.</p> Signup and view all the answers

<p>The resistance of up to 80% of coagulase-negative staphylococci to penicillinase-resistant penicillin limits effective treatment options.</p> Signup and view all the answers

<p>They are non-hemolytic bacteria identified by biochemical tests like MSA (-) and coagulase tests.</p> Signup and view all the answers

<p>Jet black colonies on tellurite glycine agar indicate the growth of S.aureus due to its ability to reduce tellurite.</p> Signup and view all the answers

<p>In cases mimicking Staphylococcus aureus infections or in patients with compromised immune systems.</p> Signup and view all the answers

<p>Small to medium-sized, non-hemolytic, white opaque colonies.</p> Signup and view all the answers