Environmental persistence and virulence of Salmonella spp. Isolated from a poultry slaughterhouse.

Salmonella spp. is responsible for severe foodborne disease, and is one of the main agents involved in foodborne outbreaks worldwide. Contamination occurs mainly as a result of poultry and egg consumption since they can carry some serotypes pathogenic to humans. The aim of the study was to evaluate the persistence and pathogenic potential of Salmonella spp. (n = 40) isolated from poultry slaughterhouse mats, using adhesion and invasion assays, antimicrobial susceptibility by disc diffusion, and biofilm production as phenotypic tests and genotypic analyses. Polystyrene mats presented 3.2 times greater chance of isolating Salmonella than canvas mats. Besides, we observed resistance to tetracycline (17.5%), ampicillin (10%), cefotaxime (7.5%), trimethoprim-sulfamethoxazole (5%), and chloramphenicol (2.5%). All strains possessed the invA, sipB, sipD, ssaR, sifA, sitC, iroN, tolC, flgK, fljB, and flgL genes. The genes sopB and sipA were both present in 92.5% of the isolates, while sopD and spvB were observed in 90% and 32.5% of strains, respectively. All strains adhered to and invaded HeLa cells. Regarding biofilm production, 31 (77.5%) strains were able to produce biofilm on polystyrene microplates. Using PFGE, we detected the persistence of clones in the environment for up to 18 fromthe 20 weeks. The ability of these strains to produce a biofilm and thus persist in the environment and disperse through contact surfaces in the processing plant favors the contamination of food, aggravated by the pathogenic potential of these isolates demonstrated by their adhesion capacity, invasion and resistance to various antibiotic agents.

Frequency, serotyping and antimicrobial resistance pattern of Salmonella from feces and lymph nodes of pigs / Isolamento, sorotipagem e padrões de resistência a antimicrobianos de Salmonella em fezes e linfonodos de suínos

Salmonellosis is a foodborne disease caused by bacteria of the genus Salmonella, being pigs and pork-products potentially important for its occurrence. In recent decades, some serovars of Salmonella have shown increase of resistance to conventional antimicrobials used in human and animal therapy, with serious risks for public health. The aim of this study was to evaluate feces (n=50), mediastinal (n=50), mesenteric (n=50) and mandibular (n=50) lymph nodes obtained from slaughter houses for Salmonella spp. Positive samples were serotyped and subjected to an in vitro antimicrobial susceptibility test, including the extended-spectrum beta-lactamase (ESBL) production. Salmonella species were identified in 10% (20/200) of total samples. From these, 20% (10/50) were identified in the submandibular lymph nodes, 18% (9/50) in the mesenteric lymph nodes, 2% (1/50) in feces and 0% (0/50) in the mediastinal lymph nodes. The serotypes found were Salmonella Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg and S. Derby with 5% (5% each). All strains showed resistance to at least one antimicrobial; 90% were resistant to four or more antimicrobials, and 15% were multidrug-resistant. Resistance to ciprofloxacin, tetracycline and nalidixic acid was particularly prevalent amongst the tested serovars. Here, we highlighted the impact of pigs in the epidemiological chain of salmonellosis in domestic animals and humans, as well as the high antimicrobial resistance rates of Salmonella strains, reinforcing the necessity for responsible use of antimicrobials for animals as an emergent One Health issue, and to keep these drugs for human therapy approaches.(AU)

Nas últimas décadas, o aumento de cepas circulante de Salmonella concomitantemente a resistência microbiana tem despertado a preocupação dos órgãos de Saúde Pública. Deste modo, o objetivo do presente trabalho foi pesquisar a presença de Salmonella a partir de fezes (n=50), linfonodos mediastinos (n=50), mesentéricos (n=50) e submandibular (n=50) oriundos de um abatedouro suíno. As cepas isoladas foram sorotipadas e testadas quanto a resistência antimicrobiana. A presença de Salmonella isolada foram em 10% (20/200) do total de amostras, sendo 20% dos linfonodos submandibulares, 18% dos linfonodos mesentéricos e 2% das fezes. Os sorotipos encontrados foram S. Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg (5%) e S. Derby (5%). Todas a cepas apresentaram resistência a pelo menos um antimicrobiano testado, sendo 90% resistente pelo menos quatro antimicrobianos. Destes, 15% foram classificadas como multidrogas resistentes. Os antimicrobianos mais resistentes entre os sorovares isolados foram a ciprofloxacina, tetraciclina e o ácido nalidixico. A presença de cepas de Salmonella resistente a antimicrobianos na espécie suína tem gerado um grande impacto epidemiológico entre homem e animal, reforçando cada vez mais a necessidade do uso adequado de drogas principalmente relacionado com o tema One Health.(AU)

Frequency, serotyping and antimicrobial resistance pattern of Salmonella from feces and lymph nodes of pigs / Isolamento, sorotipagem e padrões de resistência a antimicrobianos de Salmonella em fezes e linfonodos de suínos

Salmonellosis is a foodborne disease caused by bacteria of the genus Salmonella, being pigs and pork-products potentially important for its occurrence. In recent decades, some serovars of Salmonella have shown increase of resistance to conventional antimicrobials used in human and animal therapy, with serious risks for public health. The aim of this study was to evaluate feces (n=50), mediastinal (n=50), mesenteric (n=50) and mandibular (n=50) lymph nodes obtained from slaughter houses for Salmonella spp. Positive samples were serotyped and subjected to an in vitro antimicrobial susceptibility test, including the extended-spectrum beta-lactamase (ESBL) production. Salmonella species were identified in 10% (20/200) of total samples. From these, 20% (10/50) were identified in the submandibular lymph nodes, 18% (9/50) in the mesenteric lymph nodes, 2% (1/50) in feces and 0% (0/50) in the mediastinal lymph nodes. The serotypes found were Salonella Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg and S. Derby with 5% (5% each). All strains showed resistance to at least one antimicrobial; 90% were resistant to four or more antimicrobials, and 15% were multidrug-resistant. Resistance to ciprofloxacin, tetracycline and nalidixic acid was particularly prevalent amongst the tested serovars. Here, we highlighted the impact of pigs in the epidemiological chain of salmonellosis in domestic animals and humans, as well as the high antimicrobial resistance rates of Salmonella strains, reinforcing the necessity for responsible use of antimicrobials for animals as an emergent One Health issue, and to keep these drugs for human therapy approaches.(AU)

Nas últimas décadas, o aumento de cepas circulante de Salmonella concomitantemente a resistência microbiana tem despertado a preocupação dos órgãos de Saúde Pública. Deste modo, o objetivo do presente trabalho foi pesquisar a presença de Salmonella a partir de fezes (n=50), linfonodos mediastinos (n=50), mesentéricos (n=50) e submandibular (n=50) oriundos de um abatedouro suíno. As cepas isoladas foram sorotipadas e testadas quanto a resistência antimicrobiana. A presença de Salmonella isolada foram em 10% (20/200) do total de amostras, sendo 20% dos linfonodos submandibulares, 18% dos linfonodos mesentéricos e 2% das fezes. Os sorotipos encontrados foram S. Typhimurium (55%), S. enterica subsp. enterica 4,5,12: i: - (35%), S. Brandenburg (5%) e S. Derby (5%). Todas a cepas apresentaram resistência a pelo menos um antimicrobiano testado, sendo 90% resistente pelo menos quatro antimicrobianos. Destes, 15% foram classificadas como multidrogas resistentes. Os antimicrobianos mais resistentes entre os sorovares isolados foram a ciprofloxacina, tetraciclina e o ácido nalidixico. A presença de cepas de Salmonella resistente a antimicrobianos na espécie suína tem gerado um grande impacto epidemiológico entre homem e animal, reforçando cada vez mais a necessidade do uso adequado de drogas principalmente relacionado com o tema "One Health".(AU)

Caracterização de sorotipos em linhagens do gênero Salmonella isoladas de diferentes afecções em animais domésticos / Serotype characterization of Salmonella strains isolated from different affections in domestic animals

Foram caracterizados os sorotipos, o perfil de sensibilidade microbiana e os achados clínico-epidemiológicos em 53 linhagens do gênero Salmonella isoladas de 41 cães, nove equinos e três bovinos, acometidos por diferentes manifestações clínicas entre 1997 e 2007. Salmonella Typhimurium (45,3 por cento), Salmonella enterica (22,6 por cento), Salmonella Enteritidis (7,5 por cento), Salmonella enterica subsp enterica 4,5,12i (5,7 por cento), Salmonella Newport (5,7 por cento), Salmonella Dublin (3,8 por cento), Salmonella Agona (3,8 por cento), Salmonella Glostrup (3,8 por cento), Salmonella Saintpaul (1,8 por cento) foram os sorotipos encontrados. Ciprofloxacina (100,0 por cento), norfloxacina (100,0 por cento) e gentamicina (100,0 por cento) foram os antimicrobianos mais efetivos, enquanto a maior resistência das linhagens foi observada para ceftiofur (28,5 por cento) e florfenicol (7,0 por cento). As linhagens foram isoladas de animais com enterite, infecção do trato urinário, septicemia, piometra, pneumonia e conjuntivite. Ressalta-se para o predomínio do sorovar Typhimurium nas diferentes manifestações da salmonelose nos animais. Destaca-se, também, a identificação de sorotipos nos animais que também são observados em casos de salmonelose em humanos(AU)

The serotype characterization, antimicrobial susceptibility profile, and clinical-epidemiological findings were evaluated in 53 Salmonella spp. strains isolated from 41 dogs, nine horses and three cattle presenting different clinical manifestations between 1997 at 2007. Salmonella Typhimurium (45.3 percent), Salmonella enterica (22.6 percent), Salmonella Enteritidis (7.5 percent), Salmonella enterica subsp. enterica 4,5,12i (5.7 percent), Salmonella Newport (5.7 percent), Salmonella Dublin (3.8 percent), Salmonella Agona (3.8 percent), Salmonella Glostrup (3.8 percent), Salmonella Saintpaul (1.8 percent) were the more common serotypes. Ciprofloxacin (100.0 percent), norfloxacin (100.0 percent) and gentamicin (100.0 percent) were more effective drugs while resistance of isolates was observed to ceftiofur (28.5 percent) and florfenicol (7.0 percent). The strains were isolated from animals with enteritis, urinary tract infections, septicaemia, pyometra, pneumonia and conjuntivits. The results showed the high frequency of Salmonella Typhimurium serotype in different animals studied. The study highlighted also the presence of serotypes in our animals that also have been identified in humans with salmonellosis.(AU)

Caracterização de sorotipos em linhagens do gênero Salmonella isoladas de diferentes afecções em animais domésticos / Serotype characterization of Salmonella strains isolated from different affections in domestic animals

Foram caracterizados os sorotipos, o perfil de sensibilidade microbiana e os achados clínico-epidemiológicos em 53 linhagens do gênero Salmonella isoladas de 41 cães, nove equinos e três bovinos, acometidos por diferentes manifestações clínicas entre 1997 e 2007. Salmonella Typhimurium (45,3 por cento), Salmonella enterica (22,6 por cento), Salmonella Enteritidis (7,5 por cento), Salmonella enterica subsp enterica 4,5,12i (5,7 por cento), Salmonella Newport (5,7 por cento), Salmonella Dublin (3,8 por cento), Salmonella Agona (3,8 por cento), Salmonella Glostrup (3,8 por cento), Salmonella Saintpaul (1,8 por cento) foram os sorotipos encontrados. Ciprofloxacina (100,0 por cento), norfloxacina (100,0 por cento) e gentamicina (100,0 por cento) foram os antimicrobianos mais efetivos, enquanto a maior resistência das linhagens foi observada para ceftiofur (28,5 por cento) e florfenicol (7,0 por cento). As linhagens foram isoladas de animais com enterite, infecção do trato urinário, septicemia, piometra, pneumonia e conjuntivite. Ressalta-se para o predomínio do sorovar Typhimurium nas diferentes manifestações da salmonelose nos animais. Destaca-se, também, a identificação de sorotipos nos animais que também são observados em casos de salmonelose em humanos

The serotype characterization, antimicrobial susceptibility profile, and clinical-epidemiological findings were evaluated in 53 Salmonella spp. strains isolated from 41 dogs, nine horses and three cattle presenting different clinical manifestations between 1997 at 2007. Salmonella Typhimurium (45.3 percent), Salmonella enterica (22.6 percent), Salmonella Enteritidis (7.5 percent), Salmonella enterica subsp. enterica 4,5,12i (5.7 percent), Salmonella Newport (5.7 percent), Salmonella Dublin (3.8 percent), Salmonella Agona (3.8 percent), Salmonella Glostrup (3.8 percent), Salmonella Saintpaul (1.8 percent) were the more common serotypes. Ciprofloxacin (100.0 percent), norfloxacin (100.0 percent) and gentamicin (100.0 percent) were more effective drugs while resistance of isolates was observed to ceftiofur (28.5 percent) and florfenicol (7.0 percent). The strains were isolated from animals with enteritis, urinary tract infections, septicaemia, pyometra, pneumonia and conjuntivits. The results showed the high frequency of Salmonella Typhimurium serotype in different animals studied. The study highlighted also the presence of serotypes in our animals that also have been identified in humans with salmonellosis.