Screening of Lactobacillus plantarum subsp. plantarum with Potential Probiotic Activities for Inhibiting ETEC K88 in Weaned Piglets

Abstract

For screening excellent lactic acid bacteria (LAB) strains to inhibit enterotoxigenic Escherichia coli (ETEC) K88, inhibitory activities of more than 1100 LAB strains isolated from different materials, and kept in the lab, were evaluated in this study. Nine strains with inhibition zones, at least 22.00 mm (including that of a hole puncher, 10.00 mm), and good physiological and biochemical characteristics identified by 16S DNA gene sequencing and recA gene multiple detection, were assigned to Lactobacillus (L.) plantarum subsp. plantarum (5), L. fermentum (1), L. reuteri (1), Weissella cibaria (1) and Enterococcus faecalis (1), respectively. As investigated for their tolerance abilities and safety, only strain ZA3 possessed high hydrophobicity and auto-aggregation abilities, had high survival rate in low pH, bile salt environment, and gastrointestinal (GI) fluids, was sensitive to ampicillin, and resistant to norfloxacin and amikacin, without hemolytic activity, and did not carry antibiotic resistance genes, but exhibited broad spectrum activity against a wide range of microorganisms. Antibacterial substance may attribute to organic acids, especially lactic acid and acetic acid. The results indicated that the selected strain L. plantarum subsp. plantarum ZA3 could be considered a potential probiotic to inhibit ETEC K88 in weaned piglets for further research.

Effects of the antimicrobial peptide WK3 on diarrhea, growth performance and intestinal health of weaned piglets challenged with enterotoxigenic Escherichia coli K88

“…Enterotoxigenic E. coli (ETEC) K88 is one of the most common pathogens causing diarrhea in postweaning piglets. After colonizing the small intestine, ETEC produces enterotoxins that stimulate intestinal inflammation, thereby causing diarrhea ( 4 ). Piglets can no longer obtain passive immunity from sows after weaning, which raises their susceptibility to ETEC infections.…”

Screening of Lactic Acid Bacteria with Inhibitory Activity against ETEC K88 as Feed Additive and the Effects on Sows and Piglets

“…Pazhoohan et al [33] reported that Lactobacillus showed antagonistic activity against ETEC with an inhibition zone diameter of 27.00 mm by the same method. Wang et al [20] screened the strain L. plantarum subsp. plantarum ZA3, which showed antagonistic activity against ETEC K88 with an inhibition zone 23.00 mm in diameter by this method.…”

“…The adhesion ability of selected LAB strains is reflected by cell surface hydrophobicity and auto-aggregation, and these two characteristics were tested using methods described by Wang et al [20]. Strains with high cell surface hydrophobicity and auto-aggregation were selected for 16S rRNA gene analysis.…”

“…Hemolytic activity of LAB isolates assay was determined according to the description in Wang et al [20], and Staphylococcus aureus ATCC 6538 T with hemolytic properties was used as positive control. Strains that tested free of hemolysis would be used for animal testing.…”

Screening and Characterization of Lactic Acid Bacteria with Broad-Spectrum Antimicrobial Activity from Tibetan Qula, a Yak Milk Cheese

“…Wang W et al [17]. Simulated gastric uid: 0.35 g of pepsin was diluted in 100 mL 0.2% saline, pH was adjusted to 2.5 with dilute hydrochloric acid, ltered and sterilized.…”