Detection and quantification of Salmonella spp. in poultry slaughterhouses of southern Brazil

Abstract

Introduction: Salmonella is a major cause of foodborne illness throughout the world. The use of quantitative techniques is important for assessing the risk and determining the capacity of each step of the slaughtering process to decrease or increase bacterial contamination. We aimed to detect and to quantify the presence of Salmonella in Brazilian processing plants by real-time quantitative polymerase chain reaction (qPCR).
 Methodology: A total of 139 poultry slaughterhouses samples were collected in order to detect to and quantify Salmonella by qPCR.
 Results: Almost all collection points (3/18), except water from pre-chiller tank, carcasses after pre-chiller, and carcasses frozen at -12ºC for 60 days, and 49% (68/139) of samples were positive for Salmonella. Quantification means varied equally among all of the tested sources, and we could not establish any pattern of variation. A large proportion (52.6%) of cloacal swabs was Salmonella-positive. Also, contamination in transport cages was increased after the cleaning process, indicating that the process was ineffective. The overall prevalence in samples obtained during the slaughtering process was 48.9%, and on the whole rinsed carcasses, this proportion was 50%. The detection of Salmonella in frozen carcasses, even after long periods of storage, indicates that the carcasses are a potential source of infection for consumers.
 Conclusions: We found that contamination levels remain similar throughout the slaughtering. qPCR proved to be an efficient method for the detection of Salmonella.

Direct Detection and Quantification of Bacterial Pathogens from Broiler Cecal Samples in the Slaughter Line by Real-Time PCR

“…Previous studies have already demonstrated that PCR methods can be used to detect foodborne pathogens in chicken and other poultry samples (Alonso et al, 2011;Park et al, 2014). However, they have been carried out only after bacterial preenrichment and/or isolation (Borges et al, 2019;Souza et al, 2019;Borges et al, 2020). The present study demonstrated that Salmonella, Campylobacter, and C. perfringens can be detected directly from broilers' cecal samples obtained in slaughter houses.…”

“…Bacterial loads were estimated in all positive samples and the results ranged from 2.8 log 10 to 6.4 log 10, with a mean of 4.3 log 10 bacteria/g of cecal content. This result could be compared to another Brazilian study that presented Salmonella loads ranging from 1.16 to 3.64 log 10 CFU/mL in chicken carcasses (Borges et al, 2019).…”

“…Salmonella was detected in 6.7% of the ceca from the sampled flocks. Some previous studies in Brazil described a wide range of Salmonella frequencies in chicken samples collected at different stages of slaughter: 48.9% in samples obtained during the slaughtering process in the Rio Grande do Sul state (Borges et al, 2019); 9.33% of slaughterhouse samples (whole carcasses, cuts, viscera, and chiller water) in Mato Grosso do Sul state (Boni et al, 2011); 0.2% of cloacal swabs collected from broilers chicken flocks in the metropolitan region of Fortaleza (Bezerra et al, 2016); 3.7% of chicken carcasses from a slaughterhouse in the state of Mato Grosso (Cunha-Neto et al, 2018); and 1.66% of cloacal swabs and 26.66% of chicken carcasses in the state of Rio de Janeiro (Baptista et al, 2018). Moreover, 37.5% of raw chicken legs sold at retail in the state of São Paulo were positive for Salmonella (Ristori et al, 2017).…”

“…The results reported in this study are concerning, as they show that three important bacterial pathogens are present in chickens from broiler flocks in commercial slaughterhouses and could contaminate poultry food products. It is noteworthy that dissemination of these pathogens in Brazilian poultry is widely variable depending on the region, poultry establishment, poultry flock, and type of sample analyzed (Cortez et al, 2006;Bezerra et al, 2016;Würfel et al, 2018;Borges et al, 2019). Specific hygiene and biosecurity measures to control these foodborne pathogens throughout the poultry production chain are extremely necessary to reduce economic losses and minimize the risk of exposure of consumers to these bacteria.…”

Salmonella spp. virulent and resistant multidrug recovered from chicken carcasses in Brazil

“…In addition, these genes are considered from community origin, and are common in hospital environments (SUN et al, 2013). Thus, the dissemination of resistant strains points out the importance of the Salmonella spp control in poultry meat (BORGES et al, 2019;SIVASANKAR et al, 2020).…”