Optimization of media for detection of hydrogen peroxide production by Lactobacillus species.
A healthy vaginal ecosystem has been shown to be protective against the acquisition of human immunodeficiency virus and gonorrhea, and women who are colonized with H(2)O(2)-producing lactobacilli are more likely to maintain a normal vaginal flora than women with lactobacilli that do not produce H(2)O(2). The purpose of this study was to formulate a testing medium that better supports the growth and detection of H(2)O(2) by a broader range of lactobacilli than a published, widely used agar formulation (TMB). The new medium (TMB-Plus) consists of brucella agar base, 3,3',5,5'-tetramethylbenzidine, horseradish peroxidase, starch, vitamin K, hemin, magnesium sulfate, manganese sulfate, and horse serum. To validate the new formula, 256 vaginal isolates and ATCC strains were inoculated onto TMB-Plus and, for comparison, onto TMB. Growth was enhanced for 69% of the isolates on TMB-Plus, and 48% had enhanced color production. The percentage of H(2)O(2)-positive isolates increased from 71% on TMB to 79% on TMB-Plus. Formulations using Rogosa or MRS agar base in combination with peroxidase and a chromogen did not support the growth of all of the strains of Lactobacillus, and fewer H(2)O(2)-producing strains were detected on these formulations than on TMB-Plus. This new medium better supports the growth of a wider range of Lactobacillus strains isolated from the vagina and enhances the color production of H(2)O(2)-producing strains.
Rabe
L K
LK
Magee-Women's Research Institute, The University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Hillier
S L
SL
D000362:Agar; D001431:Bacteriological Techniques; D002863:Chromogenic Compounds / Q000378:metabolism; D003470:Culture Media; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007778:Lactobacillus / Q000145:classification / Q000254:growth & development* / Q000378:metabolism; D014621:Vagina / Q000382:microbiology*
D002863:Chromogenic Compounds; D003470:Culture Media; D000362:Agar; D006861:Hydrogen Peroxide