Antimicrobial activity and antibiotic resistance of lactic acid bacteria isolated from Malaysian stingless bee's gut

Aims: A study had been conducted to isolate lactic acid bacteria (LAB) from Malaysian stingless bee gut and to determine their population in 4 stingless bee species. The isolated LAB was subjected to antimicrobial activity against selected bacterial pathogens and antibiotic resistance towards several antibiotics. Methodology and results: Lactic acid bacteria isolated from the gut of 4 Malaysian stingless bee species (Heterotrigona itama, Geniotrigona thoracica, Tetragonula laeviceps and Tetrigona melanoleuca) were subjected to antimicrobial activity test against selected pathogenic bacteria, antibiotic resistance assay and identification of potent LAB through molecular 16S rRNA gene sequencing. A total of 99 putative LAB isolated from 4 stingless bee species were found to exhibit LAB characteristics such as Gram positive, oxidase negative and catalase negative. Out of 99 isolates, only 7 LAB isolates viz. TIS 5, TIS 25, TID 18, TTD 6, TLH 13, TLH 16 and TMH 2 exhibited strong to intermediate inhibition against Staphylococcus aureus, Eschericia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Bacillus cereus, and Bacillus subtilis. The antibiotic susceptibility test demonstrated that all 7 isolates were not susceptible to streptomycin (10 mu g), gentamycin (10 mu g), tetracycline (30 mu g) and kanamycin (30 mu g). Nevertheless, these 7 isolates exhibited intermediate susceptibility to antibiotic penicillin G (10 mu g), carbenicillin (100 mu g) and ampicillin (10 mu g). These 7 potent LABS were identified genotypically as Lactobacillus plantarum (TIS 5 and TIS 25), Fructobacillus tropaeoli (TID 18 and TTD 6) and Pediococcus pentosaceus (TLH 13, TLH 16 and TMH 2). Conclusion, significance and impact of study: Findings from this study demonstrated the stingless bee's gut as a reservoir for LAB with anticipating antimicrobial properties and tolerance to certain antibiotics.