Thermophilic Campylobacter survey in chilled and frozen poultry meatat retail in Concórdia, Santa Catarina
Gritti, DianaVaz, Clarissa Silveira LuizVoss-Rech, DaianeAlves, LuanaBortolinil, Fabiana
Background: Human campylobacteriosis has become a major foodborne disease, although little information is available about the role it plays in the scenario of foodborne diseases in Brazil. Since thermophilic Campylobacter (C.) species are often found in the intestinal tract of broiler chickens, consumption of contaminated poultry meat has been considered a risk factor for Campylobacter human infection. Campylobacter has been described as extremely susceptible to a variety of environmental stresses; hence the difficulty to establish cultures of the microorganism in the laboratory. In addition, it has been shown to decline in refrigerated and frozen foods. Currently there is a need for data on Campylobacter contamination level in Brazilian poultry meat. This work describes a survey performed in chilled and frozen poultry meat obtained from different retailers in Concórdia, Santa Catarina, Brazil. Materials, Methods & Results: This study analyzed 24 samples of fresh (chilled or frozen) poultry meat portions (thighs and drumsticks) produced by three different Brazilian broiler chicken processors, which were purchased from three different retailers in Concórdia, Santa Catarina. Campylobacter isolation was performed according to ISO 10272-1:2006. Individual samples (25g) were enriched in 225 mL of Bolton Broth in microaerobic atmosphere at 37°C for 4h to 6h, then at 41.5°C for 44h (+/- 4h). Aliquots were streaked in Modif ed Charcoal Cefoperazone Deoxycholate Agar (mCCDA) and Campy-Cefex Agar at 41.5°C in a microaerobic atmosphere for 44h (+/- 4h). Suspected colonies were subcultured in Blood Agar no 2 plates for confirmation by morphology, Gram staining, tests for catalase, oxidase and hippurate and indoxyl acetate hydrolysis test. Enriched Bolton Broth aliquots were also analyzed by Polymerase Chain Reaction (PCR) to amplify a 287 bp sequence of the 16S rRNA gene from thermophilic Campylobacter. Although C. jejuni positive control was isolated and confirmed by the morphological and biochemical tests described, all samples analyzed were negative for the presence of thermophilic Campylobacter. However, either mCCDA or Campy-Cefex Agar showed an abundant growth of non-Campylobacter cells. Moreover, all samples analyzed were negative in PCR analysis, although the C. jejuni reference strain used as PCR positive control showed the expected DNA fragment amplified. Discussion: Higher levels of Campylobacter contamination in poultry meat have been found by other studies, which used different isolation protocols in comparison to the present work. This study shows that Campylobacter isolation procedure according to ISO 10272-1:2006 allowed the growth of contaminants in both selective media used. It might be result of enrichment for 48 h or proliferation of ESBL producing Escherichia coli, able to hydrolyze cefoperazone in the selective medium used, which could underestimate the presence of Campylobacter in samples. In this sense, the PCR assay was essential to corroborate the negative result in Campylobacter isolation. Because poultry meat analyzed was negative for the presence of thermophilic Campylobacter, it was not possible to assess any difference between chilled or frozen storage on the bacteria survival. The present study might reflect low rates of Campylobacter contamination in poultry meat available at retail in Concórdia, Santa Catarina, Brazil, although it cannot replace good hygienic practices as well as consumer education.(AU)
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