Detection and Quantification of Campylobacter in Poultry Slaughterhouses Using Conventional Microbiological Technique, Most Probable Number, and Real-Time PCR.

Campylobacteriosis is one of the most common bacteria causing human gastroenteritis. Poultry is a major reservoir of Campylobacter spp. as well as the main source of transmission. Due to the increased occurrence of campylobacteriosis, poultry slaughterhouses are under pressure to deliver carcasses with low contamination. However, a few studies have been carried out to evaluate Campylobacter contamination of broiler carcasses in Brazilian slaughter lines. Therefore, in this study, we aimed at detecting and quantifying the thermotolerant Campylobacter spp. at different stages of the poultry slaughtering process. The samples were collected from 12 points in three slaughterhouses in southern Brazil, at an interval of 12 months, and were tested for Campylobacter spp. by conventional microbiological technique, the most probable number, and real-time PCR. A total of 432 samples were analyzed. The majority of strains belonged to Campylobacter jejuni (92%), and the flock positivity among the three techniques was similar in most cases. Campylobacter was detected in all slaughtering stages. Although contamination has remained similar (p > 0.05) throughout almost all the slaughter process, evisceration seemed to be an important source of contamination. Our results reinforce the idea that the final carcass quality after the slaughtering process is directly influenced by the level of contamination of the broiler flocks on arrival at the processing plant.

Behavior of salmonella heidelberg and salmonella enteritidis strains following broiler chick inoculation: evaluation of cecal morphometry, liver and cecum bacterial counts and fecal excretion patterns.

Over the years, Salmonella Heidelberg (SH) has gained prominence in North America poultry production and in the poultry production of other countries. Salmonella Heidelberg has been isolated and reported from poultry and poultry products in Brazil since 1962, whereas Salmonella Enteritidis (SE) has only emerged as a serious problem in poultry and public health since 1993. These strains of Salmonella can cause intestinal problems in newly hatched chicks, and infection may persist until adulthood. Upon slaughter of chickens, Salmonella can contaminate carcasses, a condition that poses a threat to human health. The aim of this study was to compare the fecal excretion of Salmonella Enteritidis and Salmonella Heidelberg in newly hatched chicks (orally inoculated with 10(5)ufc/mL each) until 20 days of age. In addition, the ratio of cecal villus height:crypt depth (morphometry) and liver and cecum cell counts was analyzed in chicks ranging from 0 to 3 days of age and infected with these two Salmonella strains. One hundred seventeen chicks were separated into one of three experimental groups: a control group, an SE-infected group and an SH-infected group. Eight chicks per group were euthanized at 6, 12 and 72 hours post-inoculation (pi) to allow for Salmonella isolation from the liver and cecum and for the collection of the cecum for villi and crypt analysis. Other birds were allowed to mature to 20 days of age and cloacal swabs were taken at 2, 6, 13 and 20 days pi to compare the fecal excretion of inoculated strains. The Salmonella Enteritidis group had a higher number of cells excreted during the trial. Both strains were isolated from the liver and cecum by 6h pi. At 12h pi the Salmonella Heidelberg group had high cell counts in the cecum. No difference was found in liver cell counts. Both strains showed lower villus height:crypt depth ratio than the control group post-infection.

Análise comparativa entre microbiologia convencional, ELISA e PCR para detecção de Salmonella enteritidis, S. typhimurium, S. gallinarum e S. pullorum em carne de frango contaminada artificialmente

O presente trabalho teve como objetivo realizar uma análise comparativa das técnicas de Reação em Cadeia pela Polimerase(PCR) e Ensaio Imunoenzimático (ELISA SALVIA®) com o método microbiológico convencional para detecção e SalmonellaEnteritidis (SE), S. typhimurium (ST), S. gallinarum (SG) e S. pullorum (SP) em carne de frango. As amostras foram contaminadasartificialmente com diluições de 10-7, 10-8 e 10-9 para SE e ST e de 10-4, 10-5 e 10-6 para SG e SP, com cinco repetições decada diluição, totalizando 300 análises. Os testes foram realizados em cinco diferentes laboratórios para a validação dastécnicas. Na avaliação geral dos dados obtidos, a microbiologia convencional obteve 56,67% (170/300) de recuperação dasamostras contaminadas artificialmente, enquanto as técnicas de ELISA e PCR representaram 71% (213/300) e 75% (225/300), respectivamente. A análise dos resultados de detecção de Salmonella através dos testes ELISA e PCR, em relação aomicrobiológico convencional, apresentaram diferença estatística (p=0,0001, teste de MacNemar). Não houve diferença significativaentre os resultados da PCR e do ELISA. Os resultados alcançados demonstraram que, comparado ao microbiológicoconvencional, tanto o ELISA quanto a PCR foram eficazes para detecção dos sorovares de Salmonella nas amostras de carnede frango avaliadas.