Evaluation of Lactobacilli for Antagonistic Activity Against the Growth, Adhesion and Invasion of Klebsiella pneumoniae and Gardnerella vaginalis

Abstract

Urinary tract infections are the most common infectious diseases in babies and the elderly and are often acquired as nosocomial infections. The purpose of the present study was to identify strains of lactic acid bacteria (LAB) which could be used as alternatives to antibiotics for the treatment of urinary tract infections because of their ability to inhibit urinary tract pathogens (Klebsiella pneumoniae BCRC 10694 and Gardnerella vaginalis BCRC 17040). We screened 370 LAB strains using spent culture supernatants by inhibition zone assay to assess their antimicrobial effects. We studied the effect of heat, pH and enzyme treatment on the inhibitory activity of LAB strain supernatants. Anti-growth activity against urinary tract pathogens was evaluated by co-culture inhibition assay using seven LAB strains. Anti-adhesion and anti-invasion activities against urinary tract pathogens were evaluated by SV-HUC-1 uroepithelium cell culture. The results showed that the supernatants had good heat stability. However, antibacterial activity disappeared entirely at pH 7.0. After enzyme treatments, the supernatants showed first-or second-order inhibitory effects on K. pneumonia BCRC 10694. The survival rate of urinary tract pathogens was 0-10.65% and pH of the culture medium decreased after co-culture with LAB strains for 4 h. In a competition assay, PM2 and RY2 inhibited urinary tract pathogens. PM68, PM78, PM201, PM206 and PM229 inhibited the invasion of SV-HUC-1 cells by G. vaginalis BCRC17040. In conclusion, PM78, PM229 and RY2 showed the strongest inhibitory activity against urinary tract pathogens and could be suitable for use in the treatment of urinary tract infections.

Antibacterial Activity of Lactobacillus Strains Isolated from Mongolian Yogurt against Gardnerella vaginalis

“…In a study [38], three strains of Lactobacillus isolated from cocoa fermentation had an activity against G. vaginalis ATCC 49154 using the agar diffusion technique and the supernatant halos of L. plantarum 6.2 and L. plantarum 7.1 were 12 and 11 mm, respectively. Another research showed that the CFS of some LAB had an inhibitory effect on the growth of G. vaginalis BCRC 17040 (inhibition diameter was about 2-3 mm) [39]. In above three research, the inhibition zone against G. vaginalis was about 3 mm after subtracting the well diameter, and the result in our study was 1.46 to 3.02 mm.…”

A Single Plasmid of Nisin-Controlled Bovine and Human Lactoferrin Expressing Elevated Antibacterial Activity of Lactoferrin-Resistant Probiotic Strains

“…Second, the two selected conventional probiotic hosts, L. delbrueckii and L. gasseri (our laboratory stock), were isolated from yogurt and human milk, respectively, revealing that the two strains originate from natural and safe sources. Finally, L. delbrueckii has been shown previously to display both antibacterial activities and detoxification capacity against uremic toxins in vitro [ 28 , 40 ]. As for L. gasseri (our laboratory stock), we confirmed that the milk-isolated L. gasseri can display anti-bacterial activities, as well as both bile salt and acid tolerance abilities in our preliminary analysis.…”

“…Thus, we provide new support that L. delbrueckii may also secrete bacteriocin, but this needs to be further investigated. On the other hand, the previous study also indicated that L. delbrueckii is not active against the growth of G. vaginalis , an important etiology of bacterial vaginosis in humans [ 28 ]. Thus, it will be interesting to test the antibacterial potency of our recombinant L. delbrueckii/HLF and L. delbrueckii/BLF clones against the growth of G. vaginalis in our next study.…”

“…To evaluate the recombinant probiotic strains in vitro inhibition of food-borne pathogens, agar well diffusion assay was conducted according to the method of Shim, et al and Tsai et al with modifications [ 27 , 28 ]. Initially, each of three recombinant probiotic strains, i.e., L. gasseri /BLF, L. delbrueckii/ HLF, and L. delbrueckii /BLF were grown in 48 mL MRS broth at 37 °C to an optimal OD 600 of 1.2.…”

Influence of the Microalga Chlorella vulgaris on the Growth and Metabolic Activity of Lactobacillus spp. Bacteria

“…Moreover, 35 Lactobacillus species meet the European Food Safety Authority (EFSA) criteria for a qualified presumption of safety (QPS) [ 12 ]. Due to their cholesterol-lowering properties [ 13 , 14 ], anti-inflammatory [ 15 ], antioxidant [ 16 ], and antagonistic activity [ 17 , 18 , 19 ], LAB are used in the prevention and treatment of many diseases, such as irritable bowel syndrome [ 20 ], dysbiosis [ 18 ], urinary tract infections [ 17 ], antibiotic-associated diarrhea, infectious diarrhea [ 21 ], allergies [ 15 ], and atopic dermatitis [ 22 , 23 ].…”