A new Lactobacillus gasseri strain HMV18 inhibits the growth of pathogenic bacteria

Abstract To search for a new eco-friendly therapy for infectious disease caused by Escherichia coli, Staphylococcus aureus or Klebsiella oxytoca, we collected the vaginal swabs from healthy women, screened for Lactobacillus and found a strain repressing the growth of pathogenic bacteria. The new isolate was identified as L. gasseri by the colony morphology, Gram staining, biochemical reactions and confirmed by the 16S rDNA sequencing. The HMV18 strain inhibited the growth of food-borne pathogens such as E. coli, S. aureus and K. oxytoca. The HMV18 strain was sensitive to penicillin, ampicillin, erythromycin, tetracycline and chloramphenicol. The HMV18 strain produced α-hemolysis. Pathological histology of the mice ileum showed that the mucosa, villi, lamina propria and crypt depth remained intact and there was no inflammation or hyperemia in the L. gasseri HMV18 gavaged group. L. gasseri HMV18 could not up-regulate inflammatory cytokines level of plasma. All the results suggested L. gasseri HMV18 is a candidate probiotic to be an additive for food preservation or drug to prevent food-borne diseases.