Identification ofLactobacillus ruminus SPM0211 isolated from healthy Koreans and its antimicrobial activity against some pathogens

Abstract

The intestinal microbiota are important to the host with regard to resistance they impart against bacterial infections and their involvement in mediating metabolic functions. Lactic acid producing bacteria such as Lactobacillus play an important physiological role in these matters. The aim of the present study was to isolate Lactobacillus sp. that inhibits enteric pathogens. Initially, 17 isolates from healthy Koreans were collected on Lactobacillus selective medium. Resistance of the isolates to antibiotics including rifampicin, streptomycin, clindamycin and vancomycin was measured. One of the isolate was identified as Lactobacillus ruminus on the basis of bacterial cell morphology, cultural characteristic and biochemical characteristics, 16S rRNA sequence analysis and PCR-RAPD. Antimicrobial activity of the bacterium against Vancomycin Intermediate Resistant Staphylococcus aureus (VISA) and Vancomycin-Resistant Enterococci (VRE) was measured. About 10(4) cells of VISA or VRE were mixed with 1, 5, and 9 mL of L. ruminus SPM 0211 and the final volume was adjusted to 10 mL with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 h, serially diluted and then plated on BHI agar plates. As numbers of L. ruminus SPM 0211 were increased, viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of SPM 0211 was observed after 9 h incubation in any mixture, almost completely inhibiting the growth of these two bacteria. The results suggest that the freshly isolated L. ruminus SPM 0211 may be used as a pro-biotic microbe that prevents the colonization of enteric pathogens and can thereby promote good gastrointestinal health.

Probiotic treatment of vancomycin‐resistant enterococci: a randomised controlled trial

“…Potential mechanisms for the effectiveness of LGG in clearing intestinal infections include competitive colonisation, wherein LGG binds to the enteric epithelium and inhibits adhesion of pathogens such as Escherichia coli (a process that has been demonstrated in vitro) 11 . Secondly, LGG may possess antimicrobial activity against VRE, similar to that of L. ruminus SPM0211, 12 although this has not been demonstrated. Thirdly, LGG may compete with VRE for consumption of monosaccharides, thereby slowing VRE growth.…”

The effect of long-term lactobacilli (lactic acid bacteria) enteral treatment on the central nervous system of growing rats

“…These bacteria are part of a complex balanced ecosystem in the gastrointestinal tract that includes a few hundred species belonging to over 200 genera [1]. The inhibitory effect of lactobacilli on other microorganisms, including pathogens, is well known [2]. Moreover, lactobacilli are involved in the protection of the intestinal barrier defence system [3], production of short-chain fatty acids [4], vitamin synthesis [5], reduction of the levels of neurotoxic compounds such as ammonia and indoles [6], and stimulation of the immune system [7].…”

Effects of Lactic Acid Bacteria (Lab) Supplement on The Growth Rate and Elimination of Enteropathogenic Bacteria in Calves

“…After 24 h of incubation under aerobic conditions at 37°c, viable bacterial colonies on each medium were counted. the numbers of colony forming units (cFU) are expressed as log 10 cfu/ml (28,29).…”