Lactobacillus jensenii is a normal inhabitant of the lower reproductive tract in healthy women. L. jensenii makes up 23% of vaginal microflora that is naturally occurring. It is also found on the skins of grapes at the time of their harvest. L. jensenii is sometimes used in producing fermented foods. L. jensenii produces enzymes that cause hydrolase release from the liver. Hydrolase aids in the digestion of food in the upper gastrointestinal tract. L. jensenii also produces Lactacin F. This protein reduces the population of other lactobacillus and Enterococcus bacteria. This bacterium may be valuable in the treatment of newborns to improve the digestion of breast milk. L. jensenii and other Lactobacillus species that produce hydrogen peroxide have been correlated with a decrease in the presence of gonorrhea, bacterial vaginosis, and HIV. L. jensenii was discovered by F. Gasser, M. Mandel, and M. Rogosa in 1969. Although sharing many characterization criteria, L. jensenii differed from the similar Lactobacillus leichmannii in a gel electrophoresis analysis of their respective lactic dehydrogenases. L. jensenii is Gram-positive, rod-shaped, negative for catalase and oxidase, and anaerobic. The organism can grow on blood agar. Colonies of L. jensenii are circular, colorless, small, and translucent. L. jensenii infection is rare but often fatal, with 30% of endocarditis cases caused by the organism resulting in patient mortality. While L. jensenii takes advantage of nonimmunocompetence in patients, immunocompetent cases have also been observed. In the rare occurrence of infection, L. jensenii can be treated with teicoplanin and meropenem.