Brief Article
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World J Gastroenterol. Feb 7, 2012; 18(5): 479-488
Published online Feb 7, 2012. doi: 10.3748/wjg.v18.i5.479
Safety assessment of Bifidobacterium longum JDM301 based on complete genome sequences
Yan-Xia Wei, Zhuo-Yang Zhang, Chang Liu, Pradeep K Malakar, Xiao-Kui Guo
Yan-Xia Wei, Zhuo-Yang Zhang, Chang Liu, Xiao-Kui Guo, Department of Medical Microbiology and Parasitology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
Pradeep K Malakar, Institute of Food Research, Norwich Research Park, NR4 7UA, Norwich, United Kingdom
Author contributions: Guo XK and Wei YX designed the study; Wei YX and Liu C analyzed the data; Wei YX and Zhang ZY carried out the experiments; Wei YX wrote the paper; and Malakar PK edited the paper.
Supported by The National Key Program for Infectious Diseases of China, No. 2008ZX10004 and 2009ZX10004; the Program of Shanghai Subject Chief Scientist, No. 09XD1402700; the Program of Shanghai Research and Development, No. 10JC1408200; and a China Partnering Award from the Biotechnology and Biological Sciences Research Council, United Kingdom
Correspondence to: Xiao-Kui Guo, Professor, Department of Medical Microbiology and Parasitology, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. microbiology@sjtu.edu.cn
Telephone: +86-21-64453285 Fax: +86-21-64453285
Received: May 25, 2011
Revised: July 31, 2011
Accepted: August 7, 2011
Published online: February 7, 2012
Abstract

AIM: To assess the safety of Bifidobacterium longum (B. longum) JDM301 based on complete genome sequences.

METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resistance genes and genes encoding enzymes responsible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test.

RESULTS: JDM301 was shown to contain 36 genes associated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence factors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, amikacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imipenem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated.

CONCLUSION: The safety assessment of JDM301 using information derived from complete bacterial genome will contribute to a wider and deeper insight into the safety of probiotic bacteria.

Keywords: Bifidobacterium longum; Safety assessment; Genome; Antibiotic resistance; Harmful metabolite; Virulence factor