Most studies of the human microbiome have focused on westernized people with life-style practices that decrease microbial survival and transmission, or on traditional societies that are currently in transition to westernization. We characterize the fecal, oral, and skin bacterial microbiome and resistome of members of an isolated Yanomami Amerindian village with no documented previous contact with Western people. These Yanomami harbor a microbiome with the highest diversity of bacteria and genetic functions ever reported in a human group. Despite their isolation, presumably for >11,000 years since their ancestors arrived in South America, and no known exposure to antibiotics, they harbor bacteria that carry functional antibiotic resistance (AR) genes, including those that confer resistance to synthetic antibiotics and are syntenic with mobilization elements. These results suggest that westernization significantly affects human microbiome diversity and that functional AR genes appear to be a feature of the human microbiome even in the absence of exposure to commercial antibiotics. AR genes are likely poised for mobilization and enrichment upon exposure to pharmacological levels of antibiotics. Our findings emphasize the need for extensive characterization of the function of the microbiome and resistome in remote nonwesternized populations before globalization of modern practices affects potentially beneficial bacteria harbored in the human body.

Identification of anaerobes recovered from clinical samples is complicated by the fact that certain grampositive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with ''quick'' fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes.

, an obligate anaerobic bacterium, was recently reported to be an important cause of bacterial pharyngitis with a prevalence as high as that of group A (GAS) in adolescents and young adults. Importantly, is the primary causative agent of the life-threatening Lemierre's syndrome, and screening of pharyngeal samples may be warranted for its early detection and prevention. The aim of this study was to determine the prevalences of and groups A and C/G streptococci as agents of bacterial pharyngitis in children. Pharyngeal samples ( = 300) were collected from pediatric patients presenting to the emergency department with signs and symptoms of pharyngitis. Overall, 10 (3.3%), 79 (26.3%), and 4 (1.3%) patients were PCR positive for , GAS, and group C/G streptococci, respectively. The prevalence of was significantly higher in patients between the ages of 14 and 20 years at 13.5% than in patients aged 14 years and younger (1.9%, < 0.001). All positive patients presented with signs and symptoms similar to GAS pharyngitis. Our data demonstrated a potential role for as a pathogen of pharyngitis among young adults, but suggests that the prevalence of is low in preadolescent patients.

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