Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Isolation of Probiotic Lactobacilli from Human Infants? Stool Samples Exhibiting Antimicrobial Activity Against Pathogenic Microorganisms

Radhika Trikha1*, Avantika Sharma1, Vishal Guglani2, Praveen Rishi3 and Rupinder Tewari1

1Department of Microbial Biotechnology, Panjab University, Chandigarh - 160014, India. 2Department of Paediatrics, Government Medical College and Hospital, Chandigarh - 160030, India. 3Department of Microbiology, Panjab University, Chandigarh - 160014, India.

Received on 12 December 2014 and accepted on 07 January 2015

 

ABSTRACT

Emergence of drug resistance amongst bacterial isolates has forced the scientific community to develop new and natural alternatives to prevent and treat diseases. One such alternative is the use of probiotics. The present study was undertaken to isolate probiotic lactobacilli from stool samples of 30 healthy breast fed infants (1-3 months old) to control gastrointestinal diseases in infants and children. Out of 50 isolates, three exhibited superior probiotic attributes like tolerance to lysozyme, low pH and bile salts and strong adhesion to intestinal epithelial Caco-2 cells. Two isolates were identified as Lactobacillus pentosus and third one as L. plantarum. All three lactobacilli inhibited the growth of common microbial gut pathogens (Shigella dysenteriae, Escherichia coli, Salmonella thyphimurium, Staphylococcus aureus, Proteus vulgaris and Kleibseilla pneumoniae). They successfully coaggregated pathogens mentioned above (15-55%) and competitively inhibited adherence of pathogens (8-48%) on intestinal epithelial Caco-2 cells. Moreover, these lactobacilli were completely biocompatible to each other and sensitive to commonly used antibiotics (amikacin, amoxicillin-clavulanic acid, cefoperazone, ciprofloxacin, cotrimoxazole, nalidixic acid). In conclusion, three lactobacilli isolates identified as L. pentosus strains and L. plantarum have the strong potential to be exploited for prophylactic and therapeutic control of gastrointestinal infections.

Keywords : Anti-microbial activity, co-aggregation, infant, Lactobacillus, probiotic, stool.