title: Selection, phenotyping and identification of acid and hydrogen peroxide producing bacteria from vaginal samples of Canadian and East African women.
abstract: The common but poorly understood condition known as bacterial vaginosis (BV) increases vulnerability to HIV infection and is associated with the absence of H(2)O(2)-producing Lactobacillus. Vaginal lactic acid bacteria (LAB) produce anti-HIV factors such as organic acids and hydrogen peroxide (H(2)O(2)), and may bind and inactivate HIV particles during scavenging of mannose. These factors define potential criteria for initial selection of candidate probiotics to block heterosexual transmission of HIV. Therefore, the primary goal of this study was to characterize acid production on mannose and H(2)O(2) production in vaginal isolates from Canadian adolescents (192 isolates, 16 individuals) and commercial sex workers in Nairobi, Kenya (576 isolates, 96 individuals). Selection of isolates from H(2)O(2)-detecting media suggested an idiosyncratic individual-level profile and extensive phenotypic diversity, including the identification of a subset of "double-strong" acid- and H(2)O(2)-producers with phenotypes similar to well-characterized probiotic strains. Molecular fingerprinting of all isolates by capillary electrophoresis of 16S-23S rRNA interspacer amplicons was coupled with chaperonin-60 universal target (cpn60 UT) sequencing in a subset, tentatively identifying 96% of isolates although only 19% were sequenced. Most isolates belonged to Lactobacillus, Streptococcus, Bifidobacterium or Gardnerella, with a total of 37 species in 15 genera, as well as 5 potentially novel organisms, identified in this study. This sensitivity was likely enhanced by phenotype-based selection on two chromogenic media formulations. Identification of double-strong isolates may provide a rational basis for selection and further characterization of vaginal probiotics, with potential application as part of HIV prevention initiatives in western Canada and East Africa.
authors: Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada. schellej@cc.umanitoba.ca
authors: John J
authors: JJ
authors: Schellenberg
authors: Tim J
authors: TJ
authors: Dumonceaux
authors: Janet E
authors: JE
authors: Hill
authors: Joshua
authors: J
authors: Kimani
authors: Walter
authors: W
authors: Jaoko
authors: Charles
authors: C
authors: Wachihi
authors: Jane Njeri
authors: JN
authors: Mungai
authors: Margo
authors: M
authors: Lane
authors: Keith R
authors: KR
authors: Fowke
authors: T Blake
authors: TB
authors: Ball
authors: Francis A
authors: FA
authors: Plummer
mesh_terms: D000143:Acids / Q000378:metabolism*; D000293:Adolescent; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D002170:Canada; D005260:Female; D015658:HIV Infections / Q000382:microbiology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007630:Kenya; D010641:Phenotype; D019936:Probiotics; D012306:Risk; D014621:Vagina / Q000382:microbiology*
chemical_list: D000143:Acids; D006861:Hydrogen Peroxide