Microbiology 88-173

112) A beta-hemolytic streptococci that is bacitracin-sensitive and CAMP-negative is:

114) It is important to differentiate between Enterococcus and group D streptococci because:

90) A urine Gram stain shows gram-positive cocci in clusters. The organism tested catalase positive. To SPECIATE orgainism from culture, the technician should perform a coagulase test and a/an:

103) A beta-hemolytic streptococcus that has been isolated from an ear culture grows up to the edge of a0.04 unit bacitracin disk. Which of the following tests would help to determine if the organism is Enterococcus?

120) Which of the following organisms is, to date, considered universally susceptible to penicillin:

119) The MOST critical distinction between Staphylococcus aureus and the other staphylococcus is:

113) Group B, beta- hemolytic streptococci may be distinguished from other hemolytic streptococci by which of the following procedures?

106) Of the following bacteria, the MOST frequent cause of prosthetic heart valve infections occuring within 2-3 months after surgery is:

118) Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes?

110) A gram-positive coccus isolated from a blood culture has the following characteristics:

This organism is most likely:

127) An isolate of an unknown beta-hemolytic Streptococcus is streaked perpendicular to a streak of beta-lysin-producing Staphylococcus aureus. After incubation a zone of arrowhead hemolysis is noted at the unknown Streptococcus?

101) "Nutritionally deficient" streptococci are:

133) Which one one of the following gram-negative bacilli ferments glucose?

96) Which 2 diseases are usually preceded by infection with beta-hemolytic streptococci?

105) An important cause of acutre exudative pharyngitis is:

122) How many hours after eating contaminated food do initial symptoms of staphylococcal food poisoning typically occur?

94) The optochin (ethylhydrocupreine hydrochloride) disk is used for the identification of:

130) MacConkey media for screening suspected cases of hemorrhagic E coli 0157:H7 must contain:

131) Members of the family Enterobacteriaceae share which one of the following characteristics?

123) During the past month, Staphylococcus epidermidis has been isolated from blood cultures at 2-3 times the rate from the previous year. The MOST logical explanation for the increase in these isolates is that:

104) The organism MOST commonly associated with neonatal purulent meningitis is:

128) Which of the following may be used as a positive quality control organism for the bile esculin test?

117) A beta-hemolytic, catalase-positive, gram-positive coccus is coagulase negative by the slide coagulase test. Which of the following is the MOST appropriate action in identification of this organism?

129) Infection of the urinary tract is MOST frequently associated with:

92) Viridians streptocci can be differentiated from Streptococcus pneumoniae by:

97) The enterotoxin produced by certain strains of hemolytic, coagulase positive Staphylococcus aureus:

91) The Gram stain from a blood culture shows gram-positive cocci in chains. No growth occurs on blood agar plates incubated both aerobically and anaerobically. Additional testing should be done to detect the presence of:

An organism was inoculated to a TSI tube and gave the following reactions:

Organism MOST likely is:

98) A gamma-hemolytic Streptococcus that blackens bile esculin but does not grow in 6.5% NaCl broth is MOST likely:

152) A clean catch urine sample from a nursing home patient is cultured using .001mL loop. It grows 67 colonies of a lactose fermenter that has the following biochemical reactions:

What should be the microbiological report?

115) Streptococcus pneumoniae can be differentiated best from the viridans group of streptococci by:

109) Children who have infections with beta-hemolytic streptococci can develop:

99) Gram stain examination from a blood culture bottle shows dark blue, spherical organisms in clusters. Growth on sheep blood agar shows small, round, pale yellow colonies. Further tests should include:

132) Which one of the following genera is among the least biochemically reactive members of the Enterobacteriaceae?

93) A reliable test for distinguishing Staphylococcus aureus from other staphylococcus is:

136) An isolate from a stool culture gives the following growth characteristics and biochemical reactions:

These screening reactions are consistent with which of the following enteric pathogens?

137) A TSI tube inoculated with an organism gave the following reactions:
This organism is MOST likely:

:134) A sputum culture from an alcoholic seen in the ER grows gray, mucoid, stringy colonies on sheep blood agar. The isolate grows readily on MacConkey agar and forms mucoid, dark pink colonies. The colonies yield the following test results:

The organism is MOST likely:

116) Characteristically, enterococci are:

95) In the optochin (ethylhydrocupreine hydrochloride) susceptibility test, if there is a zone of inhibition of 19-30mm surrounding the disk following overnight incubation at 37C, the colony MOST likely consists of:

100) Gram-positive cocci in chains are seen on a Gram stain from a blood culture. The organism grows as a beta-hemolytic colony. Further tests that could be performed include:

102) After 24 hours a blood culture from a newborn grows catalase-negative, gram-positive cocci. The bacterial colonies are too small, translucent and beta- hemolytic on a blood agar plate. Biochemical test results of a pure culture are:

Assuming that all controls react properly and reactions are verified, the next step would be to:

111) A beta-hemolytic streptococci that is bacitracin- sensitive and CAMP-negative is:

108) A catheterized urine is inoculated onto blood and MacConkey agar using a 0.01 mL loop. After 48 hours, 68 colonies of a small translucent nonhemolytic organism grew on blood agar but not MacConkey. Testing reveals small gram positive, catalase-negative cocci. The preliminary report and follow up testing would be:

88) In a quality control procedure on a new batch of Mueller-Hinton plates using a stock culture of Staphylococcus aureus (ATCC 25923), all the disk zones are too small. The MOST likely reason for this is that the:

125) A yellow colony from a wound culture tested catalase-positive and coagulase-negative. The organism stained as gram-positive cocci clusters. Which of the following tests would differentiate between a coagulase- negative Staphylococcus and Micrococcus?

121) A beta-hemolytic gram-positive coccus was isolated from the cerebrospinal fluid of a 2-day-old infant with signs of meningitis. The isolate grew on sheep blood agar under aerobic conditions and was resistant to a bacitracin disc. Which of the following should be performed for the identification of the organism?

89) Which one of the following combinations of organisms would be appropriate as controls to test the functions listed?