Prevalence and genotype identification of Salmonella spp. isolated from a meat product artisanally produced in Bragança Artigo de Conferência uri icon

resumo

  • Previous meta-analytical work estimated that in Portuguese meat products intended to be eaten cooked, the overall occurrence of Salmonella spp. was 9.7% (95% CI: 7.0–13.4%). One of these meat products is alheira, which is a fermented sausage made of poultry/pork meat, bread and seasonings. The objective of this study was to investigate prevalence, numbers and serovars of Salmonella spp. in alheira sausages artisanally produced in Bragança, Portugal. Methodology: This work was undertaken in three stages: (i) sampling of 52 alheiras from markets and traditional fairs; (ii) detection of Salmonella using culture methods and enumeration by MPN; and (iii) molecular confirmation of isolates (invA and randomly-cloned chromosomal fragment), and typing of S. Enteritidis (SefA), Typhimurium (fliC) or Pullorum (glgC) by PCR. Results: Analysis of 52 sausage samples revealed the presence of Salmonella spp. in 8 samples (incidence of 0.154; 95% CI: 0.080–0.275), although all of these positive samples were unpacked sausages from traditional fairs (n=21), indicating therefore the higher Salmonella prevalence in alheiras sold in these establishments (incidence 0.381; 95% CI: 0.207–0.591). Salmonella mean concentration was 1.938 log MPN/g (s.d 0.839 log MPN/g). All of the 33 biochemically- and serologically-confirmed isolates coded for the invA gene. Multiplex-PCR revealed that only 3 of the positive isolates had the presence of SefA genes; which indicated that 9.1% of the isolates belonged to Enteritidis; while 21 isolates belonged to Typhimurium (63.6%) since they coded for fliC gene. The other 9 isolates (27.3%) were of serovars different from Enteritidis/Typhimurium/Pullorum since they only presented genes general for Salmonella. From the positive alheiras, Enteritidis or Typhimurium serovar was recovered from two samples, while the other samples harboured at least two serovars. Conclusion and Relevance: Salmonella continues to be a frequent contaminant of alheiras produced in Bragança, and, in particular, of those sold in local fairs (38%). Not unexpectedly, Typhimurium and Enteritidis represented the prevailaing serovars (72.7%) since they are linked to pork and poultry meat, the main raw materials of alheira. Regional producers must be urgently informed on the implementation of preventive and corrective actions in their current manufacturing processes and hygiene standards. keywords Alheira; Portugal; PCR; molecular typing

data de publicação

  • janeiro 1, 2019