کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4368577 1616716 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Antibiotic resistance and microbial composition along the manufacturing process of Mozzarella di Bufala Campana
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش تغذیه
پیش نمایش صفحه اول مقاله
Antibiotic resistance and microbial composition along the manufacturing process of Mozzarella di Bufala Campana
چکیده انگلیسی

The use of antibiotics as growth promoters in livestock, banned in all EU member states in January 2006, has led to selection of antibiotic resistant strains within environmental bacteria, including gram-positive, non pathogenic bacteria that colonize the GI tract of humans and animals. In Italy and in other Mediterranean countries, fermented foods employing environmental bacteria pre-existing in the raw substrates, rather than industrial starters of defined genotype, represent a significant proportion of cheese and meat products carrying the official PDO designation (Protected Designation of Origin). Our study focused on the microbiological and molecular analysis of lactobacilli and of other lactic acid bacteria (LABs) isolated from the Italian PDO product water buffalo Mozzarella cheese, with the aim of identifying genes responsible for tetracycline, erythromycin and kanamycin resistance. We isolated over 500 LAB colonies from retail products, as well as from raw milk and natural whey starters employed in their production. Microbiological analysis showed that about 50% of these isolates were represented by lactobacilli, which were further characterized in terms of species and strain composition, as well as by determining phenotypic and genotypic antibiotic resistance. To overcome the limits of culture-dependent approaches that select only cultivable species, we have also extracted total DNA from the whole microbiome present in the cheese and investigated the presence of specific antibiotic resistance genes with molecular approaches. Genetic determinants of antibiotic resistance were identified almost exclusively in bacteria isolated from the raw, unprocessed substrates, while the final, marketed products did not contain phenotypically resistant lactobacilli, i.e. displaying MIC values above the microbiological breakpoint. Overall, our results suggest that the traditional procedures necessary for manufacturing of this typical cheese, such as high temperature treatments, lead to a final product with low bacterial counts, lower biodiversity and lack of significant presence of antibiotic resistant lactobacilli.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Food Microbiology - Volume 128, Issue 2, 10 December 2008, Pages 378–384
نویسندگان
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