title: A new medium containing mupirocin, acetic acid, and norfloxacin for the selective cultivation of bifidobacteria.
abstract: Various culture media have been proposed for the isolation and selective enumeration of bifidobacteria. Mupirocin is widely used as a selective factor along with glacial acetic acid. TOS (transgalactosylated oligosaccharides) medium supplemented with mupirocin is recommended by the International Dairy Federation for the detection of bifidobacteria in fermented milk products. Mupirocin media with acetic acid are also reliable for intestinal samples in which bifidobacteria predominate. However, for complex samples containing more diverse microbiota, the selectivity of mupirocin media is limited. Resistance to mupirocin has been demonstrated by many anaerobic bacteria, especially clostridia. The objective was to identify an antibiotic that inhibits the growth of clostridia and allows the growth of bifidobacteria, and to use the identified substance to develop a selective cultivation medium for bifidobacteria. The susceptibility of bifidobacteria and clostridia to 12 antibiotics was tested on agar using the disk diffusion method. Only norfloxacin inhibited the growth of clostridia and did not affect the growth of bifidobacteria. Using both pure cultures and faecal samples from infants, adults, calves, lambs, and piglets, the optimal concentration of norfloxacin in solid cultivation media was determined to be 200 mg/L. Our results showed that solid medium containing norfloxacin (200 mg/L) in combination with mupirocin (100 mg/L) and glacial acetic acid (1 mL/L) is suitable for the enumeration and isolation of bifidobacteria from faecal samples of different origins.
authors: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6-Suchdol, 16521 Czech Republic. Electronic address: vlkova@af.czu.cz.
authors: Eva
authors: E
authors: Vlková
authors: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6-Suchdol, 16521 Czech Republic.
authors: Hana
authors: H
authors: Salmonová
authors: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6-Suchdol, 16521 Czech Republic.
authors: Věra
authors: V
authors: Bunešová
authors: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6-Suchdol, 16521 Czech Republic.
authors: Martina
authors: M
authors: Geigerová
authors: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6-Suchdol, 16521 Czech Republic.
authors: Vojtěch
authors: V
authors: Rada
authors: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6-Suchdol, 16521 Czech Republic.
authors: Šárka
authors: Š
authors: Musilová
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D000328:Adult; D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods*; D001644:Bifidobacterium / Q000254:growth & development* / Q000302:isolation & purification*; D002417:Cattle; D003470:Culture Media / Q000737:chemistry*; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016712:Mupirocin / Q000378:metabolism*; D009643:Norfloxacin / Q000378:metabolism*; D012767:Ships; D013552:Swine
chemical_list: D003470:Culture Media; D016712:Mupirocin; D009643:Norfloxacin; D019342:Acetic Acid
keywords: Antibiotics; Bifidobacteria; Clostridia; Cultivation media; Mupirocin; Norfloxacin