tetracycline and Cryptococcosis

We describe the laboratory-confirmed etiologies of illness among participants in a hospital-based febrile illness cohort study in northern Tanzania who retrospectively met Integrated Management of Adolescent and Adult Illness District Clinician Manual (IMAI) criteria for septic shock, severe respiratory distress without shock, and severe pneumonia, and compare these etiologies against commonly used antimicrobials, including IMAI recommendations for emergency antibacterials (ceftriaxone or ampicillin plus gentamicin) and IMAI first-line recommendations for severe pneumonia (ceftriaxone and a macrolide). Among 423 participants hospitalized with febrile illness, there were 25 septic shock, 37 severe respiratory distress without shock, and 109 severe pneumonia cases. Ceftriaxone had the highest potential utility of all antimicrobials assessed, with responsive etiologies in 12 (48%) septic shock, 5 (14%) severe respiratory distress without shock, and 19 (17%) severe pneumonia illnesses. For each syndrome 17-27% of participants had etiologic diagnoses that would be non-responsive to ceftriaxone, but responsive to other available antimicrobial regimens including amphotericin for cryptococcosis and histoplasmosis; anti-tuberculosis therapy for bacteremic disseminated tuberculosis; or tetracycline therapy for rickettsioses and Q fever. We conclude that although empiric ceftriaxone is appropriate in our setting, etiologies not explicitly addressed in IMAI guidance for these syndromes, such as cryptococcosis, histoplasmosis, and tetracycline-responsive bacterial infections, were common.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Amphotericin B; Ampicillin; Anti-Infective Agents; Bacterial Infections; Ceftriaxone; Child; Cohort Studies; Cryptococcosis; Emergencies; Female; Gentamicins; Histoplasmosis; Humans; Infections; Macrolides; Male; Microbial Sensitivity Tests; Middle Aged; Pneumonia, Bacterial; Respiratory Distress Syndrome; Shock, Septic; Tanzania; Tetracycline; Young Adult

Congenitally immunodeficient nude (nu/nu) mice and their immunocompetent littermates (nu/+) were used to determine whether the absence of thymus-matured T cells would alter the capacity of Cryptococcus neoformans to colonize their mucosal surfaces or enhance their susceptibility to systemic cryptococcosis, or both, following oral challenge. We present data demonstrating that an encapsulated strain of C. neoformans serotype A colonized the alimentary tracts of germfree, conventional, and antibiotic-treated conventional nu/nu mice. Scanning electron microscopy showed that C. neoformans adhered to the epithelial surfaces of the oral cavities, esophagi, and gastrointestinal tracts of monoassociated nu/nu and nu/+ mice, and culture data showed that there were more viable C. neoformans cells in the alimentary tracts of nu/nu mice than of nu/+ mice. Tetracycline-treated conventional nu/nu, but not nu/+, mice were also colonized with C. neoformans following intragastric challenge. C. neoformans-monoassociated and tetracycline-treated conventional nu/nu mice succumbed to disseminated cryptococcosis with cerebral involvement 3 to 4 weeks after oral challenge, whereas no mortality was observed for similarily challenged nu/+ mice. These results demonstrate that an encapsulated strain of C. neoformans can colonize mucosal surfaces and cause systemic cryptococcosis in immunodeficient nu/nu mice, suggesting that the alimentary tract can be a portal of entry for C. neoformans in an immunodeficient host. These data also indicate that functional T cells play an important role in resistance to systemic cryptococcosis of endogenous origin.

Topics: Animals; Cryptococcosis; Cryptococcus; Cryptococcus neoformans; Feces; Germ-Free Life; Intestinal Mucosa; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Electron, Scanning; Mouth Mucosa; Tetracycline

Topics: Amino Sugars; Anti-Bacterial Agents; Bacteria; Candidiasis; Carbenicillin; Cephalosporins; Cryptococcosis; Drug Synergism; Flucytosine; Glycosides; Gonorrhea; Humans; Meningococcal Infections; Minocycline; Pseudomonas Infections; Spectinomycin; Sulfonamides; Tetracycline; Trimethoprim

Topics: Actinomycosis; Amphotericin B; Biomedical Research; Blastomycosis; Candidiasis; Coccidioidomycosis; Cryptococcosis; Cycloserine; Erythromycin; Histoplasmosis; Humans; Mycoses; Nocardia Infections; Penicillins; Pharmacology; Sporotrichosis; Stilbamidines; Sulfamerazine; Tetracycline

Topics: Amphotericin B; Cryptococcosis; Encephalitis; Humans; Isoniazid; Meningoencephalitis; Streptomycin; Tetracycline; Tuberculosis; Tuberculosis, Pulmonary