Faculty Bibliography

Leprosy or Hansen's disease is a chronic infectious disease caused by an acid-fast bacillus, Mycobacterium leprae (M. leprae). The bacilli proliferate in macrophages infiltrating the skin and gain entry to the dermal nerves via the laminar surface of Schwann cells where they replicate. After entry, the Schwann cells proliferate and then die. Conclusive identification of M. leprae DNA in a sample can be obtained by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the heat shock 65 gene (hsp65). Molecular epidemiology will make it possible to study the global distributions of M. leprae, explore the relationship between genotypes-incidence rates, mode of transmission, and the type of disease (tuberculoid vs. lepromatous). We amplified DNA using PCR for the hsp65 gene from 24 skin lesions from patients diagnosed with various types of leprosy. Fifteen out of 24 were positive for the hsp65 gene. Digestion with HaeIII-PAGE for the RFLP confirmation of the presence of M. leprae DNA showed the typical pattern in 5 out of 24 and 2 novel patterns in 10 out of 24 patients. We confirmed the presence of M. leprae DNA by sequencing the genes for gyraseA or B and folP, which contained only M. leprae specific single nucleotide polymorphisms (SNPs). Thus, we describe novel hsp65 RFLPs for M. leprae found in a high frequency making them ideal for future epidemiology and transmission studies

Both Bartonella quintana and Coxiella burnetii are known to cause of blood culture negative endocarditis. In such case, the diagnosis is usually established by serology. A case of Bartonella quintana endocarditis is described where the serology was falsely positive for Coxiella burnetii. This case demonstrates the difficulty in distinguishing these two etiologic agents by routine serologic testing

A 73-year-old man was hospitalized with dyspnea, fevers, chills, myalgia, diffuse pulmonary infiltrates, peripheral eosmophilia, and eosinophiha on bronchoalveolar lavage BAL). BAL also revealed the presence of Trichomonas tenax and Entamoeba gingivalis. The patient did not respond to broad-spectrum antibiotics but had a dramatic response to corticosteroids. The authors hypothesize that T tenax may have caused this patient's eosinophilic pneumonia and that it may be an unrecognized cause in other similar cases

Focal neurologic deficits, lymphocytic pleocytosis, and low cerebrospinal fluid glucose levels can point to a variety of diagnoses. In the case of a man who presented with a seizure, imaging studies and a new polymerase chain reaction assay helped point to a diagnosis of a rare infection: amebic encephalitis

BACKGROUND: Pyogenic liver abscess, a potentially life-threatening disease, has undergone significant changes in epidemiology, management, and mortality over the past several decades. METHODS: We reviewed the data for patients admitted to Bellevue Hospital and New York University Downtown Hospital (New York, New York) over a 10-year period. RESULTS: Of 79 cases reviewed, 43% occurred in patients with underlying biliary disease. The most common symptoms were fever, chills, and right upper quadrant pain or tenderness. The most common laboratory abnormalities were an elevated white blood cell count (in 68% of cases), temperature >or=38.1 degrees C (90%), a low albumin level (70.2%), and an elevated alkaline phosphatase level (67%). Seventy percent of the abscesses were in the right lobe, and 77% were solitary. Klebsiella pneumoniae was identified in 41% of cases in which a pathogen was recovered. Eighteen (50%) of 36 Asian patients had K. pneumoniae isolated, in contrast to 6 (27.3%) of 22 non-Asian patients (not statistically significant). Fifty-six percent of cases involved treatment with percutaneous drainage. Although prior reports noted mortality of 11%-31%, we observed only 2 deaths (mortality, 2.5%). CONCLUSIONS: The data suggest that K. pneumoniae has become the predominant etiology of pyogenic liver abscess and that mortality from this disease has decreased substantially