Effects of H₂O₂-Producing Lactobacilli on Neisseria gonorrhoeae Growth and Catalase Activity

• Published in: The Journal of infectious diseases Vol. 170; no. 5; pp. 1209 - 1215
• Main Authors: Zheng, He-Yi, Alcorn, Timothy M., Cohen, Myron S.
• Format: Journal Article
• Language: English
• Published: United States University of Chicago Press 01.11.1994
• Subjects: Antigens; Catalase - antagonists & inhibitors; Catalase - metabolism; Cell growth; Chickenpox; Hospitalization; Hydrogen Peroxide - metabolism; Hydrogen-Ion Concentration; Infections; Lactobacillus - physiology; Major Articles; Military personnel; Neisseria gonorrhoeae - enzymology; Neisseria gonorrhoeae - growth & development; Operating rooms; Spleen cells; T lymphocytes; Yeasts
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/170.5.1209

In the vagina and endocervix, Neisseria gonorrhoeae must interact with complex microflora. Among these are lactobacilli, which may inhibit the growth of gonococci. Lactobacillus acidophilus, which produce$H_2$ $O_2$($LB^+$), and L. acidophilus and Lactobacillus casei, which do not produce$H_2$ $O_2$($LB^-$), were coincubated with catalase-positive and -deficient strains of N. gonorrhoeae. When the incubation medium was maintained at pH 7.3, neither$LB^+$nor$LB^-$affected gonococcal growth. However,$LB^+$caused a significant increase in expression of gonococcal catalase, which could be offset by exposure of the bacteria to exogenous catalase. When coincubation medium was at lower pH (4.8-5.0), there was a significant decrease in gonococcal survival and catalase activity, which was only partly reversed by exogenous catalase. Lysates of$LB^+$also effectively inhibited gonococcal catalase. This inhibition was retained upon heating of the lysate to 100°C for 15 min but was lost with proteinase K treatment. Thus,$LB^+$may inhibit growth of gonococci by acidification of the environment, secretion of$H_2$ $O_2$, and production of protein inhibitors.