Sensibilidade a antimicrobianos de bactérias isoladas de linguiça suína frescal

Abstract

Fresh sausages can be potential vehicles for pathogenic microorganisms, what may associate them with food diseases. The resistance attributed to antimicrobial agents by pathogenic bacteria becomes a worrying factor. Strains which have antibiotic multiresistance profile represent a serious problem to public health, resulting in lower availability of medication in order to treat diseases in human beings. Thus, alternatives such as the addition of organic acids in the elaboration of fresh meat products should be implemented to avoid that the food carries resistant pathogens. This work had as its principal objectives the evaluation of the microbiological quality of the sausages; the identification of bacterial isolates through the sequencing of the region 16S of rDNA; the selection of bacteria with antimicrobial multiresistance profile; the selection of organic acid with better efficiency in the multiresistance bacterial inhibition; and the elaboration of fresh pork sausages inoculated with different multiresistant bacteria strains aiming to evaluate the inhibition of pathogens by lactic acid. Twenty industrial fresh pork sausage samples, from diverse trademarks, were purchase from various places located in Minas Gerais State, from June and August 2010. Analyses to the evaluation of the microbiological quality of the product were performed. To the antimicrobial sensitivity test, the disk diffusion agar method was used. Strains with multiresistance profile were submitted, singly, to minimum inhibitory concentration test and to minimum bactericidal concentration test, by using lactic and acetic acids, both in eight concentrations. Fresh pork sausages were made with different pathogenic bacteria, lactic acid was added in 1.5 and 4.0 M concentrations, stored under 4ºC within 15 days. The results showed the contamination of the samples by Salmonella Typhi, S. Typhimurium and S. Paratyphi, Escherichia coli and Staphylococcus xylosus and S. epidermidis. Twenty-one isolates present MAR index equal or superior to 0.5 and were considered multiresistant to the tested antimicrobials. In the minimum bactericidal concentration test, in vitro, the lactic acid was proved more efficient in the pathogen inhibition than the acetic acid. Concerning the food matrix with addition of the bacterial lineages, the lactic acid treatment, in both concentrations, slightly reduced the population of pathogens during the storage period.