Antimicrobial and Disinfectant Susceptibility of Salmonella Serotypes Isolated from Swine Slaughterhouses.

Salmonella remains one of the most common foodborne pathogens worldwide, and its resistance to antimicrobials and disinfectants has increased considerably over the years. Thus, monitoring its resistance to products commonly used in swine production is indispensable for the development of strategies to reduce the occurrence of bacterial resistance. In this context, our aim was to detect Salmonella at different points in swine slaughterhouses, identify the main serotypes, and evaluate their resistance to disinfectants and antimicrobials used in swine production. Salmonella at the processing plants was detected by conventional microbiology. Salmonella strains were tested for susceptibility to peracetic acid (0.5% and 1%), quaternary ammonium (0.5%), and seven antimicrobials. Twenty-eight percent of the samples were positive for Salmonella, with the most identified serotypes being Salmonella Derby, Salmonella Typhimurium, and monophasic Salmonella Typhimurium. All tested strains were susceptible to both concentrations of peracetic acid, but only 28% were susceptible to quaternary ammonium. Sixteen percent of the strains were susceptible to all tested antimicrobials. Only enrofloxacin was efficient in inhibiting the growth of all strains. The highest number of non-susceptible strains was to amoxicillin, followed by chloramphenicol, florfenicol, and doxycycline. Thirty-six percent of the strains were classified as multidrug-resistant. Salmonella were detected in all slaughtering processes, and important serotypes were recovered, including Salmonella Typhimurium, Salmonella Derby, monophasic Salmonella Typhimurium, and Salmonella Infantis. We observed high rates of resistance to quaternary ammonium and to important antimicrobial agents. Salmonella Typhimurium and Salmonella Infantis were the most resistant serotypes.

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

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.

Seletividade e produtividade de meios de cultura para isolamento de Campylobacter spp / Selectivity and productivity of culture media for isolation of Campylobacter spp

[{"text": "A campilobacteriose é uma zoonose\r\nemergente de origem alimentar\r\ncausada por bactérias do gênero\r\nCampylobacter. Vários fatores dificultam\r\no isolamento deste patógeno\r\nem amostras naturalmente contaminadas,\r\npor isso devem ser utilizadas\r\nmetodologias normalizadas bem\r\ncomo meios de cultura com desempenho\r\nadequado, prevenindo a ocorrência\r\nde resultados falso negativos.\r\nAssim, avaliou-se a performance\r\nde meios de cultura recomendados\r\npelas ISO 10272-1 para detecção\r\nde Campylobacterspp. com testes\r\nde seletividade e produtividade em\r\nculturas puras e o desempenho destes\r\nmeios em amostras de carne de\r\nfrango artificialmente contaminadas.\r\nCepas ATCC de C. coli e C. jejuni e\r\ndos interferentes S. aureus, E. coli e\r\nProteusmirabilis foram inoculadas\r\nnos meios indicados pelas normas\r\noficiais e posteriormente inoculados\r\nem amostras fortificadas. Os meios\r\ntestados, tanto em culturas puras\r\nquanto em amostras fortificadas,\r\ntiveram desempenho satisfatório,\r\nmostrando boa seletividade e produtividade,\r\npermitindo que os laboratórios\r\noptem pela combinação de\r\nmeios com melhor performance para\r\nisolamento e identificação de Campylobacter\r\nspp. em amostras naturalmente\r\ncontaminadas.(AU)", "_i": "pt"}]