Safety Evaluations of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI

• Published in: International journal of molecular sciences 2018-05, Vol.19 (5), p.1422
• Main Authors: Kim, Min Jeong, Ku, Seockmo, Kim, Sun Young, Lee, Hyun Ha, Jin, Hui, Kang, Sini, Li, Rui, Johnston, Tony V, Park, Myeong Soo, Ji, Geun Eog
• Format: Article
• Language: English
• Subjects: Acids; Amines; Ammonia; Antibiotic resistance; Antibiotics; antibiotics resistance; Bacteria; Bifidobacterium bifidum; Bifidobacterium longum; Biodegradation; Biogenic amines; Blood cells; Cadaverine; Conjugation; Consumers; Deoxyribonucleic acid; DNA; Drug resistance; Food; functional foods; Genes; Genomes; Gentamicin; Histamine; Infectivity; Lactic acid; Lactic acid bacteria; Mucin; nutraceuticals; Plasmids; Probiotics; Putrescine; Safety; Spinach; Supermarkets; Virulence; Yogurt
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms19051422

Over the past decade, a variety of lactic acid bacteria have been commercially available to and steadily used by consumers. However, recent studies have shown that some lactic acid bacteria produce toxic substances and display properties of virulence. To establish safety guidelines for lactic acid bacteria, the Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) has suggested that lactic acid bacteria be characterized and proven safe for consumers' health via multiple experiments (e.g., antibiotic resistance, metabolic activity, toxin production, hemolytic activity, infectivity in immune-compromised animal species, human side effects, and adverse-outcome analyses). Among the lactic acid bacteria, and species are probiotic strains that are most commonly commercially produced and actively studied. BGN4 and BORI have been used in global functional food markets (e.g., China, Germany, Jordan, Korea, Lithuania, New Zealand, Poland, Singapore, Thailand, Turkey, and Vietnam) as nutraceutical ingredients for decades, without any adverse events. However, given that the safety of some newly screened probiotic species has recently been debated, it is crucial that the consumer safety of each commercially utilized strain be confirmed. Accordingly, this paper details a safety assessment of BGN4 and BORI via the assessment of ammonia production, hemolysis of blood cells, biogenic amine production, antimicrobial susceptibility pattern, antibiotic resistance gene transferability, PCR data on antibiotic resistance genes, mucin degradation, genome stability, and possession of virulence factors. These probiotic strains showed neither hemolytic activity nor mucin degradation activity, and they did not produce ammonia or biogenic amines (i.e., cadaverine, histamine or tyramine). BGN4 and BORI produced a small amount of putrescine, commonly found in living cells, at levels similar to or lower than that found in other foods (e.g., spinach, ketchup, green pea, sauerkraut, and sausage). BGN4 showed higher resistance to gentamicin than the European Food Safety Authority (EFSA) cut-off. However, this paper shows the gentamicin resistance of BGN4 was not transferred via conjugation with ATCC 4356, the latter of which is highly susceptible to gentamicin. The entire genomic sequence of BGN4 has been published in GenBank (accession no.: CP001361.1), documenting the lack of retention of plasmids capable of transferring an antibiotic-resistant gene.