This study was conducted to assess the dissemination of Salmonella clonal groups in slaughterhouses that received batches of Salmonella -positive pigs and used different routine processing procedures. Eight serial sampling sessions were conducted in three slaughterhouses (A, B, and C). Blood was collected randomly (n = 25) from each batch of pigs and processed for serology. Carcasses (n = 12) were identified and sampled after dehairing, after singeing, after evisceration, and before chilling. A section of cecum also was collected. Salmonella isolates were submitted to pulsed-field gel electrophoresis. The overall seroprevalence of Salmonella was 80.6% (316 of 392 samples), and cecal contents were positive for Salmonella in 23.8% (26 of 109) of the pigs sampled. Carcasses after dehairing had a significantly higher prevalence of Salmonella (P = 0.004) and the highest Salmonella levels (median = 0.26 log CFU/300 cm(2)). The singeing step significantly affected the Salmonella status of the carcasses (P = 0.001); however, the efficacy of singeing differed among slaughterhouses. In the prechilling step, 14.7% (16 of 109) of the carcasses were positive for Salmonella. Salmonella pulsotypes found on the prechill carcasses were also found in the lairage, in the cecal contents, and on carcasses after dehairing, suggesting that the main source of contamination was the slaughter process before singeing. Slaughterhouse C was the most likely (odds ration [OR] = 6.51) to have pigs carrying Salmonella in the gut, and slaughterhouse B was the most likely (OR = 14.66) to have contaminated carcasses at the prechilling step. These findings indicate that the procedures adopted in slaughterhouse B contributed to the spread of Salmonella strains. In contrast, in slaughterhouse C the Salmonella strains carried by the pigs or found in the lairage were not recovered from prechilled carcasses, validating the effectiveness of the slaughterhouse interventions. These results indicate that an effective slaughter process can help decrease the number of Salmonella-positive carcasses in slaughterhouses that receive Salmonella-positive pig batches.
Salmonella enterica subsp. enterica plays a role as a foodborne pathogen worldwide. The consumption of contaminated pork has been associated with human salmonellosis and the increase in antimicrobial resistance among Salmonella from pigs and pork products is a concern. A total of 225 Salmonella isolates from feed mills, the lairage environment, and the intestinal contents of pigs and carcasses were investigated for their antimicrobial susceptibility. A MIC for ciprofloxacin was screened by agar dilution, and antimicrobial resistance genes were investigated by PCR assays. Among the tested isolates, 171 (76%) showed resistance to at least one antimicrobial agent, and 91 (40.4%) were multiresistant. Resistance occurred most frequently to tetracycline (54.5%), sulfonamides (39.6%), and streptomycin (33.7%). Thirty-two (94.1%) nalidixic acid-resistant isolates exhibited decreased susceptibility to ciprofloxacin. The resistance genes found were blaTEM (ampicillin), tet(A) (tetracycline), tet(B) (tetracycline/minocycline), sul1, sul2, and sul3 (sulfonamides), catA1 (chloramphenicol), floR (florfenicol/chloramphenicol), strA and strB (streptomycin), aph(3')-Ia (kanamycin), aac(3)-IIa and aac(3)-IVa (apramycin/gentamicin), aadA variant (streptomycin/spectinomycin), and dfrA1 (trimethoprim). Salmonella isolates from pig feces and carcasses displayed a higher frequency of resistance to most antimicrobials tested than isolates from feed mills. Common resistance gene profiles were found in isolates from the lairage and the intestinal content of pigs and carcasses, demonstrating that resistance genes selected on farms may be found in pork.
A tuberculose continua sendo um importante problema de saúde pública, por ser uma zoonose que tornou-se reemergente devido, principalmente, a grande incidência entre portadores de imunodeficiências. A tuberculose, causada por micobactérias do grupo mamífero, em suínos criados em sistemas comerciais, é uma doença raramente encontrada. Neste trabalho, foram necropsiados três animais, provenientes de uma granja de suínos com aproximadamente 90 animais alimentados com resíduos alimentares. Alguns animais apresentavam tosse, anorexia e dor a palpação torácica. Linfonodos e fragmentos de vísceras com lesões macroscópicas foram submetidos a exames histopatológicos e microbiológico, além da tuberculinização em 62 animais adultos da propriedade. A prova dupla comparativa com tuberculinas mamífera e aviária foi realizada em 14 fêmeas da maternidade. Foram observadas lesões características de tuberculose (forma miliar e perolada) nos animais necropsiados no período de janeiro a março de 2000. O isolamento e cultivo foram compatíveis com Mycobacterium bovis. Na leitura das tuberculinizações foram observadas 49 reações positivas, sendo que nas duplas comparativas, 14 fêmeas foram reagentess apenas para tuberculina mamífera. Todos animais da propriedade foram encaminhados para o abate e coletados materiais para exame histopatológico e microbiológico e diagnóstico pela técnica de reação em cadeia pela polimerase (PCR). Após confirmação do diagnóstico de tuberculose foi elaborado um programa de eliminação do plantel, desinfecção e vazio sanitário. Este comunicado alerta para os riscos de tuberculose em suínos criados sem cuidados de biosseguridade, sobretudo aqueles alimentados com resíduos alimentares, e suas implicações na saúde pública. ABSTRACTTuberculosis continues being an important disease which demands attention from public health as it has emerged again with many occurrences between imunodeficients peoples. In this study, one female from a small farm with around 90 animals fed with food residues, were necropsied. The symptoms before death were cough, anorexia and thoracic touching. At the necropsy was collected lymph nodes and fragments from bowels with macroscopic lesions used for the diagnosis, which should be based on microscopic examination, isolation, and identification of Mycobacterium from these sites. Beside this exams, tuberculin testing was realized in sixty-two adults animals were. Tuberculin comparative testing with Mycobacterium bovis and Mycobacterium avium was realized in fourteen sows. It has been observed lesions of tuberculosis (miliary and pearllike) in the dead female and in all animals necropsied in this period. Forty-nine positives reactions were observed in the tuberculin testing readins and in the tuberculin comparative testing the fourteen sows got positive only for mammals tuberculin. Tuberculin testing of swine with subsequent slaughter of reactors, and depopulation of entire herds. Newly materials were collected for microbiological, microscopic examination and diagnosis using polimerase chain...
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