OBJECTIVES: The aim of our study was to analyse the antibiotic susceptibility of various strains of Bifidobacterium spp. to a wide range of antimicrobial agents. METHODS: Fifty strains belonging to eight species of bifidobacteria, isolated from humans, animals or probiotic products, were tested for susceptibility to 30 antibiotics by disc diffusion on Brucella agar supplemented with 5% laked sheep blood and vitamin K1 (1 mg/L). MICs of nine anti-anaerobe agents, including three new molecules (telithromycin, linezolid and gatifloxacin), were determined using the reference agar-dilution method. RESULTS: All strains of bifidobacteria, whatever the species, were sensitive to penicillins: penicillin G, amoxicillin (MIC(50) 0.06 mg/L), piperacillin, ticarcillin, imipenem and usually anti-Gram-positive antibiotics (macrolides, clindamycin, pristinamycin, vancomycin and teicoplanin). Susceptibility to cefalothin and cefotetan was variable. Most isolates (70%) were resistant to fusidic acid. As expected, high resistance rates were observed for aminoglycosides. Metronidazole, an agent known for its anti-anaerobe activity, was ineffective against 38% of the strains. The newly commercialized molecules, telithromycin, linezolid and gatifloxacin, were active with MIC(50)S of 1 mg/L. The only variation in susceptibility observed among the different species concerned Bifidobacterium breve, which appeared to be generally more resistant. Potentially acquired resistance was only observed against tetracycline and minocycline, in 14% of the strains. CONCLUSIONS: With regard to a general concern about the safety of probiotics, such as potential transferability of resistance determinants, bifidobacteria, with their low natural and acquired resistance to 30 antibiotics, appear risk-free.
OBJECTIVES: The aim of our study was to analyse the antibiotic susceptibility of various strains of Bifidobacterium spp. to a wide range of antimicrobial agents. METHODS: Fifty strains belonging to eight species of bifidobacteria, isolated from humans, animals or probiotic products, were tested for susceptibility to 30 antibiotics by disc diffusion on Brucella agar supplemented with 5% laked sheep blood and vitamin K1 (1 mg/L). MICs of nine anti-anaerobe agents, including three new molecules (telithromycin, linezolid and gatifloxacin), were determined using the reference agar-dilution method. RESULTS: All strains of bifidobacteria, whatever the species, were sensitive to penicillins: penicillin G, amoxicillin (MIC(50) 0.06 mg/L), piperacillin, ticarcillin, imipenem and usually anti-Gram-positive antibiotics (macrolides, clindamycin, pristinamycin, vancomycin and teicoplanin). Susceptibility to cefalothin and cefotetan was variable. Most isolates (70%) were resistant to fusidic acid. As expected, high resistance rates were observed for aminoglycosides. Metronidazole, an agent known for its anti-anaerobe activity, was ineffective against 38% of the strains. The newly commercialized molecules, telithromycin, linezolid and gatifloxacin, were active with MIC(50)S of 1 mg/L. The only variation in susceptibility observed among the different species concerned Bifidobacterium breve, which appeared to be generally more resistant. Potentially acquired resistance was only observed against tetracycline and minocycline, in 14% of the strains. CONCLUSIONS: With regard to a general concern about the safety of probiotics, such as potential transferability of resistance determinants, bifidobacteria, with their low natural and acquired resistance to 30 antibiotics, appear risk-free.
Authors: Romy D Zwittink; Diny van Zoeren-Grobben; Rocio Martin; Richard A van Lingen; Liesbeth J Groot Jebbink; Sjef Boeren; Ingrid B Renes; Ruurd M van Elburg; Clara Belzer; Jan Knol Journal: Mol Cell Proteomics Date: 2017-07-06 Impact factor: 5.911
Authors: Ana Belén Flórez; Mohammed Salim Ammor; Pablo Alvarez-Martín; Abelardo Margolles; Baltasar Mayo Journal: Appl Environ Microbiol Date: 2006-08-25 Impact factor: 4.792
Authors: Abelardo Margolles; José Antonio Moreno; Douwe van Sinderen; Clara G de Los Reyes-Gavilán Journal: Antimicrob Agents Chemother Date: 2005-10 Impact factor: 5.191