Salmonella spp : avaliação epidemiológica de surtos notificados no Paraná e caracterização de isolados epidêmicos e de origem avícola

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Salmonella enterica subsp. enterica serovar Enteritidis (SE) is the main pathogen responsible for foodborne outbreaks in Paraná. Epidemiological surveillance of SE requires effective methods for subtyping and investigation of genetic diversity and origin of isolated ones, considering that this serovar presents high degree of genetic homogeneity. The use of techniques for phenotypic and genotypic characterization allows to trace the mobility of this serovar in a population and between different species. This study aimed to analyze the epidemiological profile of outbreaks of salmonellosis reported in the State of Paraná from January 1999 to December 2008, evaluate the importance of the productive chain of eggs in the epidemiology of human salmonellosis and conduct the evaluation of phenotypic and genotypic diversity of SE epidemic strains of poultry origin, isolated in this State between 1999 and 2006. In that period, there were 286 outbreaks of salmonellosis, with 45.0% associated food made from eggs, 34.8% with meat and 20.2% with products classified as various food: cheese, salads, pudding, ice cream, farofa, and pastas. The serovar prevalent was Enteritidis, found in 87.8% of the strains isolated from patients and in 80.6% of the strains from foods involved in the outbreaks. SE phage type (PT) 4 was prevalent. However, in the period studied, it was possible to verify the diversification of the phage types and since 2003 a higher prevalence of PT9. From the total outbreaks examined, 49.7% were associated with family reunions. Five thousand eggs for human consumption were analyzed, four thousand were obtained from commercial farm and a thousand, hatching eggs of incubation from broiler breeders purchased in free markets and in the informal trade. There was no isolation of Salmonella spp. in eggs from poultry business. In hatching eggs of incubation were obtained a prevalence of 52.0% and the prevalence of SE (84.6%). Strains of SE PT4 and PT9 involved in salmonellosis outbreaks occurred from the period of 2002 to 2006, isolated strains from patients with salmonellosis and strains obtained from poultry material were characterized by the technique of Pulsed Field Gel Electrophoresis (PFGE) with the enzymes Xba I and Spe I. PFGE was able to relate genotypes to phagetyping by differentiating the majority of the SE PT4 and PT9. Strains isolated from patients with salmonellosis could also be differentiated by the PFGE technique and it was also possible to observe that strains from broilers may have been sources of human salmonellosis in the period it was studied. The typing of 38 SE isolated from breeders’ biological material intended for the poultry business presented the predominance of PT7 and PT9. The molecular characterization of these strains by PFGE, allowed to vary inter- and intra-phage type, that is essential for epidemiologic investigations of SE, which shows little genetic diversity. The characterization of 97 strains of Salmonella spp. obtained from biological material of broilers in the state of Paraná, from the period of 2002 to 2006, showed the prevalence of SE in 57.9% of the samples. In lower percentage, other five serovars were identified. Among the strains of SE probable to phagetype, there was a predominance of PT7 and PT9. The observation that the SE strains analyzed in this study presented resistance to nalidixic acid, mainly strains of poultry origin, reinforces the need in reducing the selective pressure exerted by the use of quinolones in animal production. Although it has not been found relations between PFGE genotypes and patterns of resistance, the combination of both techniques allowed a better characterization of SE. This study verified the importance of SE in food borne outbreaks occurring in the State of Paraná between 1999 and 2008. The phenotypic and genotypic characterization of epidemic SE isolated and poultry origin suggests that poultry products may have been responsible for outbreaks of human’s samonelose in the that period, especially hatching eggs of incubation from broiler breeders.

ASSUNTO(S)

salmonella enteritides salmonelose alimentos - microbiologia ovos - contaminação salmonellosis food microbiology eggs contamination

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