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Case Study 2:  Eight neonates were born at full-term and developed skin lesions predominantly in the perineum or periumbilical area or both within 10 days of birth. Seven were admitted to the hospital for administration of intravenous antibiotics.  The babies were found to be born within a few days of each other at the same 100-bed hospital and were all under the age of 14 days.  None of the mothers had any type of skin infection and nasal swabs on the mothers all tested negative for Staph and Strep.  Cultures from each of the neonates contained gram-positive cocci in clusters that were catalase positive.  Nasal swabs were collected from all healthcare workers in the maternity ward and also tested negative for Staph and Strep.  One of the healthcare workers had a chronic dermatitis condition that, when cultured, tested for the same organism and susceptibility pattern as the neonates.  Case Study 2 Question 5:  What strategy would have been most effective in preventing the outbreak initially?

Coagulase, a virulence factor of Staphylococcus aureus, allows the organism to:

Which of the following organisms would be suitable as positive and negative controls respectively, for the oxidase test?

Case Study 2:   An 85-year-old male is admitted to the emergency room of a New York City hospital suffering from breathing difficulties and coughing.  He had a high fever, cough, and chest pain. He had presented to his local physician 3 days previously complaining of fever, headache, malaise, and vague respiratory symptoms.  A year ago he moved into a long-term care facility after his wife died and he has been suffering from type two diabetes for the last thirty years.  They collected sputum for culture and sensitivity.  A gram stain indicated the presence of many white blood cells and pleomorphic gram-negative coccobacilli.  An additional urine specimen was then collected and sent to a reference laboratory to confirm the diagnosis. Case Study 2 Question 1:  What was the most likely etiologic agent of infection in this patient?

List two examples of sterile sites in the body.

Neisseria meningitidis is found in the upper respiratory tract of 5% to 15% of healthy humans. In people who have had their spleens removed, there is an increased incidence of the organism causing a potentially fatal form of meningitis. This infection in a splenectomized patient would be categorized as:

Case Study 3: Answer the following questions based upon the following clinical microbiology report: DATE: 10/25/2008  21:22:13                                          bioMerieux Vitek 2 Lab Report PATIENT NAME: HARRIET MORGAN PATIENT ID00000000 SEX: F DOB: 01/01/1931 AGE: 81Y ROUTINE CULTURE  SPECIMEN: URINE  COLONY COUNT= >100,000 CFU/ML ISOLATE: STAPHYLOCOCCUS AUREUS  SUSCEPTIBILITY TEST DRUG MIC(mcg/ml) INTERPRETATION ROUTE/DOSAGE AMPICILLIN  >=16 R PO/IV250-500MGQ6H CIPROFLOXACIN >=4 R IM/IV0.5-1.0GMQ8H ERYTHROMYCIN >=8 R PO250-500MGQ6H GENTAMICIN =8 R PO400MGQ12H PENICILLIN G >=16 R IV2.0-3.0GMQ4-6H RIFAMPIN

Beta lactamase is:

Within 5 hours of returning home from lunch at your favorite all-you-can-eat buffet restaurant you feel very sick and are vomiting. The most likely causative organism is:

Case 1: The patient was a 3 1/2 week-old male who was born at term. He required intubation at that time and continued to require respiratory support. Over a 24-hour period, the infant developed bulging anterior fontanelles (the “soft spots” in the skull), increased respiratory and heart rates, wide fluctuations in blood pressure, and difficulties maintianing adequate tissue perfusion, and his peripheral white blood cell count increased from 6,300 to 13,700/ml. The child began to have focal seizures as well. A cerebrospinal fluid (CSF) examination showed 3,900 WBC/ml (increase) with 92% neutrophils, glucose 2 mg/dl (decrease), and protein of 350 mg/dl (increase). Gram staining of the child’s CSF showed a gram-positive coccus. Case Study 1 Question 4:  Which strategy would be most successful for prevention of neonatal infections with this organism?