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The majority of strains of Staphylococcus isolated from the hospital environment or hospitalized patient are usually resistant to:

A 26-year-old male with an indwelling catheter developed signs and symptoms of endocarditis.  To establish the etiology of the disease, which of the following specimens should be cultured?

A doctor has sent a sputum specimen to the laboratory.  The Gram stain show many gram-positive cocci in chains and pairs, and many alpha-hemolytic colonies are seen on the blood agar plate.  It is not clear, however, whether the organisms are Streptococcus pneumoniae or alpha-hemolytic streptococci.  Which of the following tests would make this differentiation?

An outbreak of gastroenteritis follows a seafood “fun in the sun” episode. In addition to the routine culture media for isolation of enteric pathogens the following should be added:

Normally the bicarbonate concentration is about 24 mmol/L and the carbonic acid concentration is about 1.2 mmol/L pK = 6.1, log 20 = 1.3.  Using the equation pH = pK + log (salt/acid), calculate pH.

A missionary returning from a trip to Southeast Asia is diagnosed as having scrub typhus.  What organism is responsible?

In which of the following would you find a negative urine urobilinogen?

A patient has become refractory to platelet transfusions.  Which of the following is the most probable cause?

The media used to indicate H2S production, Indole production, and motility is:

The analysis of a blood specimen reveals the following hematological values:            WBC = 25,000/cu mm (2.5 x 109/L)            HCT = 32%       Hb = 10.5 g/dl            Leukocyte differential =                         monocytes-4                 bands-25                        myelocytes-4                lymphocytes-20                        segs-30                                    metamyelocytes – 15                        promyelocytes – 2            Leukocyte alkaline phosphatase score = 150            These results are strongly indicative of what disease state?