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Biomedical subjects

M E Ohl

Publications and source records attributed to M E Ohl.

2 recordsLinked to original sources

Salmonella: a model for bacterial pathogenesis.

Salmonellae are gram-negative bacteria that cause gastroenteritis and enteric fever. Salmonella virulence requires the coordinated expression of complex arrays of virulence factors that allow the bacterium to evade the host's immune system. All Salmonella serotypes share the ability to invade the host by inducing their own uptake into cells of the intestinal epithelium. In addition, Salmonella serotypes associated with gastroenteritis orchestrate an intestinal inflammatory and secretory response, whereas serotypes that cause enteric fever establish systemic infection through their ability to survive and replicate in mononuclear phagocytes. This review explores the molecular basis of selected Salmonella virulence strategies, with an emphasis on general themes of bacterial pathogenesis as exemplified by Salmonella.

DNA, Bacterial↗

Bartonella quintana and urban trench fever.

Contemporary Bartonella quintana infections have emerged in diverse regions of the world, predominantly involving socially disadvantaged persons. Available data suggest that the human body louse Pediculus humanus is the vector for transmission of B. quintana. Descriptions of the clinical manifestations associated with contemporary B. quintana infections have varied considerably and include asymptomatic infection, a relapsing febrile illness, headache, leg pain, "culture-negative" endocarditis, and, in human immunodeficiency virus-infected persons, bacillary angiomatosis. Laboratory diagnosis is most convincing when B. quintana is isolated in blood culture, but growth often takes 20-40 days; problems exist with both sensitivity and specificity of serological assays. On the basis of available information, use of doxycycline, erythromycin, or azithromycin to treat B. quintana infections is recommended. Treatment of uncomplicated B. quintana bacteremia for 4-6 weeks and treatment of B. quintana endocarditis (in a person who does not undergo valve surgery) for 4-6 months are recommended, with the addition of a bactericidal agent (such as a third-generation cephalosporin or an aminoglycoside) during the initial 2-3 weeks of therapy for endocarditis.

Animals↗