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)

Tracing lineage by phenotypic and genotypic markers in Salmonella enterica subsp. enterica serovar 1,4,[5],12:i: - and Salmonella Typhimurium isolated in state of São Paulo, Brazil

Fifty-three Salmonella 1,4,[5],12:i:- and 45 Salmonella Typhimurium strains were characterised using phage typing, plasmid profiles and pulsed-field gel electrophoresis (PFGE) for comparison. The majority of the strains were subdivided into definitive type (DT) 41 (22.6 percent) and DT 193 (18 percent) and the 60-MDa plasmid was detected in 94.3 percent and 84.4 percent of strains, respectively. Genetic diversity was observed among all strains and 90 percent presented a > 70 percent similarity through PFGE analysis. These results suggest a close relationship between Salmonella 1,4,[5],12:i:- and Salmonella Typhimurium at the serotype level.

Salmonella serovars isolated from humans in São Paulo State, Brazil, 1996-2003 / Sorovares de Salmonella isolados de humanos no Estado de São Paulo, Brasil, 1996-2003

Salmonellosis remains an important cause of diarrheal illness in humans in São Paulo State, Brazil. In this study were identified 3554 Salmonella isolates from human infections, during the period 1996-2003. Among 68 different serovars determined, S. Enteritidis was the most frequent one in gastrointestinal and extra-intestinal infections accounting for 67.4 percent of all isolates. S. Typhimurium and S. enterica subsp. enterica (4,5,12:i:-) were most frequently isolated from children aged < 1-4 year-old, in contrast, people with S. Enteritidis infections were most likely to be 20-50 year-old. In our geographic area the continued laboratorial surveillance of salmonellosis, including serotyping, has showed the trends in Salmonella serovars causing infections in humans throughout the time.

A salmonelose permanece uma importante causa de doença diarréica em humanos no Estado de São Paulo, Brasil. Nesse estudo foram identificados 3554 isolados de Salmonella de infecções humanas, durante o período 1996-2003. Entre os 68 diferentes sorovares determinados, S. Enteritidis foi predominante em infecções gastrointestinais e extra-intestinais, responsável por 67.4 por cento de todos os isolados. S. Typhimurium e S. enterica subsp. enterica (4,5,12:i:-) foram mais freqüentemente isolados de crianças com idade de < 1 a 4 anos, em contraste, infecções por S. Enteritidis foram predominantes em pessoas entre 20 e 50 anos. A contínua vigilância laboratorial das salmoneloses, incluindo a sorotipagem, tem evidenciado os sorovares de Salmonella causando infecções humanas em nossa área geográfica ao longo do tempo.

Occurrence of Salmonella spp and Escherichia coli O157: H7 in raw meat marketed in São Paulo city, Brazil, and evaluation of its cold tolerance in ground beef

Among foodborne diseases, salmonellosis has been considered one of the major public health problems in many countries worldwide. Escherichia coli O157:H7 has been another important foodborne pathogen due to its increasing incidence as a human disease agent and its association with various kinds of foods, especially those from animal origin. Incidence of Salmonella spp. and E. coli O157:H7 in the raw meat (bovine, swine and chicken) marketed in São Paulo - Brazil was determined in 253 samples. Twenty-three samples (9.1%) were positive for Salmonella spp. Among these, 11 different serovars were identified, and S. Enteritidis was found to be the most prevalent. All the tested samples were negative for E. coli O157:H7. Salmonella Enteritidis (the predominant serovar) and E. coli O157:H7 were also tested for their cold-temperature sensitiveness in ground beef kept under refrigeration (4ºC) for 120 days and under freezing (-18ºC) for up to 90 days. E. coli O157:H7 inoculated into ground beef was more sensible to refrigeration and freezing temperatures than S. Enteritidis, but both maintained viability under freezing condition up to 90 days

Multiplex PCR identification of the atypical and monophasic Salmonella enterica subsp. enterica serotype 1,4,[5],12:i:- in São Paulo State, Brazil: frequency and antibiotic resistance patterns

Salmonella spp. é o agente etiológico da salmonelose, zoonose mundialmente distribuída e responsável por surtos de doenças transmitidas por alimentos e doenças clínicas. Sorologicamente, Salmonella enterica subsp. enterica sorotipo 1,4,[5],12:i:- correspondeu a 8,8 por cento e 1,6 por cento das cepas de Salmonella de origem humana e não-humana, respectivamente, isoladas no Estado de São Paulo, no decênio 1991-2000. Aproximadamente 28,6 por cento destas cepas amplificaram o fragmento correspondente a H:1,2 (fase flagelar dois) em testes de PCR e foram, então, identificadas como S. Typhimurium. Das 369 cepas negativas em PCR, 36,3 por cento apresentou resistência antimicrobiana, incluindo multirresistência a ampicilina, cloranfenicol, sulfonamidas, tetraciclina e estreptomicina.

Phenotypic and molecular characterization of Salmonella Enteritidis strains isolated in São Paulo, Brazil

In São Paulo State, Brazil, the epidemic increase in isolation of Salmonella Enteritidis has been observed since 1994. A total of 105 S. Enteritidis strains (72 from human and 33 from non-human sources) isolated during the period 1975-1995, previously characterized by phage typing, was analyzed by antimicrobial susceptibility, plasmid profile, and ribotyping. Over 70 percent of the strains were susceptible to all antimicrobial agents tested, however, multiple resistance to antimicrobials was observed among the studied strains, mainly those from hospitalized patients. Phage type 8 (PT-8) was predominant among the strains isolated during the period of 1975-1992, but in the following years, PT-4 was the most frequent phage type identified. Seven different plasmid profiles were detected and 96 percent of the isolates harbored a plasmid of approximately 36 MDa. Ribotyping discriminated fourteen ribotypes (R1 to R14) among the strains examined. By analysis of dendrogram the strains were included in three groups with similarity level of 60 percent. The obtained results indicate that, a single ribotype (R11), determined for PT-4 strains isolated from 1993, characterizes the epidemic clone of S. Enteritidis in our region

Phage types of Salmonella enteritidis isolated from clinical and food samples, and from broiler carcasses in Southern Brazil

272 isolates of Salmonella Enteritidis (111 isolated from frozen broiler chicken carcasses, 126 from human food and other biological materials involved in food poisoning outbreaks and 35 from different poultry materials) were selected for phage typing. From these, 111 were phage typed, 57.65 percent being classified as phage type 4, 32.43 percent as phage type 4a, 3.60 percent as phage type 6a and 0.90 percent as phage type 7, whereas 5.40 percent samples were not phage typeable. The predominance of phage type 4 is in agreement with the results published worldwide, and reinforces the need for studies related to the epidemiological meaning of these findings

Salmonella enteritidis isoladas de amostras clínicas de humanos e de alimentos envolvidos em episódios de toxinfecções alimentares, ocorridas entre 1995 e 1996, no estado do Rio Grande do Sul / Evaluation of different kinds of food involved in FPOs caused by SE in the Southern Brazilian State of Rio Grande do Sul, during the years of 1995 and 1996

Os casos de toxinfecções alimentares produzidos por Salmonella têm aumentado significativamente durante as últimas duas décadas, em todo o mundo, principalmente devido ao sorovar Enteritidis (SE). Entretanto, a real ocorrência das salmoneloses não é conhecida, uma vez que a maioria dos casos de gastroenterites transcorre sem a necessidade de hospitalizações e sem o isolamento do agente causal no alimento incriminado. Entre a população, no entanto, existe a idéia generalizada de que os alimentos preparados com produtos de origem aviária são a principal fonte da bactéria. Neste contexto, embora as aves sejam reconhecidamente reservatórios de Salmonella, outras fontes potenciais do microrganismo devem ser consideradas. Assim, buscou-se avaliar os diferentes tipos de alimentos envolvidos em episódios de toxinfecções alimentares causados por Salmonella enteritidis, no Rio Grande do Sul, entre os anos de 1995 e 1996, bem como o papel dos manipuladores de alimentos na manutenção da cadeia desta infecção.

Prevalence and antimicrobial susceptibility of Salmonella serotypes in patients from Ribeiräo Preto, Säo Paulo, Brazil, between 1985 and 1999

Salmonella strains isolated from 1,138 samples representing 28,199 biological materials (stool, urine, blood and other fluids), collected between January 1985 and January 1999 at a reference University Hospital in Ribeiräo Preto, Säo Paulo, Brazil, were studied. The most frequently detected serotypes were Salmonella enterica subspecies enterica serotype4,5,12:i:- (S. I 4,5,12:i:) (21.2 percent), S. agona (15.8 percent) and S. enteritidis (11.3 percent). A changing pattern of Salmonella serotypes was observed between 1985-1999. S. agona, which represented 27 percent of Salmonella serotypes isolated from 1985-1989, declined to 4 percent during the period from 1995 to 1999. S. enteritidis isolation remained below 1 percent until 1989; rose to 5.9 percent between 1990 and 1994, and increased to 32.3 percent between 1995-1999. S. I 4,5,12:i:-; S. Enteritidis; S. Typhimurium; S. dublin and S. infantis, showed low to moderate resistance profiles to most antimicrobial drugs. Nalidixic acid and tetracycline were the most and the least effective drugs, respectively, in the disk diffusion tests. We encountered changes in salmonellosis epidemiology in this geographical region

Salmonella: sorotipos identificados na regiäo de Säo José do Rio Preto/SP, no período de 1990-1999 / Salmonella: serotypes identified in the Säo José do Rio Preto area, SP, during the period of 1990-1999

No período de janeiro de 1990 a dezembro de 1999, no Instituto Adolfo Lutz - Lab. I de Säo José do Rio Preto-SP, foram isoladas 324 cepas de salmonella, sendo 155 de infecçöes humanas e 169 de alimentos destinados ao consumo humano. Dos 17 diferentes sorotipos identificados a partir de infecçöes humanas, S. enterica subsp. enterica sorotipo enteritidis (S. enteritidis) foi o predominante 75,0(por cento). O material fecal representou a principal fonte de isolamento das cepas, principalmente pela ocorrência dos vários surtos de doenças veiculadas por alimentos (DVA). A partir dos alimentos, 26,6(por cento) deles envolvidos em surtos de DVA, foram identificados 30 diferentes sorotipos, também com a predominância de S. enteritidis 56,2(por cento). Os alimentos apresentando maior número de isolamentos de cepas de Salmonella foram a carne e seus derivados 59,7(por cento), seguidos por ovos e seus derivados 16,0(por cento), nos quais, S. enteritidis foi o sorotipo mais prevalente 57,4(por cento) e 81,5(por cento) respectivamente. Estes resultados demonstram que S. enteritidis permanece o sorotipo mais frequentemente isolado, tanto em infecçöes humanas quanto em alimento. Os alimentos mais comumente implicados em DVA ainda säo as carnes de aves e ovos, bem como os seus derivados, quando consumidos crus ou mal cozidos. (AU)

From January 1990 to December 1999, 324 Salmonella strains were isolated at InstitutoAdolfo Lutz ­ São José do Rio Preto­SP Lab. I, 155 from human infections and 169 from food for humanconsumption. S. enterica subsp. Enterica serotype enteritidis (S. enteritidis) was the most prevalentserotype (75.0%) among the 17 different ones identified in human infections. Fecal material representedthe main human source of the isolated strains, due to several foodborne outbreaks occurring in the periodunder study. Thirty different serotypes were identified in food, S. enteritidis being the prevailing one.About 26.6% of the analyzed foods were linked to foodborne outbreaks. Foods presenting the highest rateof isolated strains were meat and its products (59.7%), followed by eggs and egg products (16.0%). Theseresults show that S. enteritidis still remains as the most common serotype isolated from human sourcesand foods. Foods frequently implicated in foodborne outbreaks are chicken meat and eggs, as well as theirproducts, particularly raw and undercooked ones. (AU)

Surtos de enfermidades transmitidas por alimentos causados por Salmonella Enteritidis / Food borne disease outbreaks caused by Salmonella Enteritidis

Säo descritos surtos de salmonelose notificados no período de julho de 1993 a junho de 1997 na regiäo Noroeste do Estado de Säo Paulo, Brasil, tendo em vista os vários surtos de veiculaçäo alimentar ocasionados por Salmonella nessa regiäo. Foram obtidos 19 inquéritos epidemiológicos para análise de dados, 87 amostras de fezes e 38 amostras de alimentos, incluindo 12 de ovos para análise microbiológica. Cepas de Salmonella foram submetidas a sorotipagem, fagotipagem e teste de sensibilidade a 13 agentes antimicrobianos. Foram acometidas 906 pessoas com 295 hospitalizaçöes. Cepas de Salmonella Enteritidis Fagotipo 4 foram isoladas de 80,5 por cento das coproculturas, de todas amostrasd de alimentos e de 41,7 por cento dos ovos. Em 22 (95,7 por cento) surtos a salmonela foi veiculada por alimentos contendo ovos crus ou semicrus. Os testes de sensibilidade a antimicrobianos revelaram sensibilidade à maioria das cepas. Considerando os resultados obtidos, torna-se necessária a implantaçäo e intensificaçäo de medidas de controle na produçäo e armazenamento dos ovos, além da orientaçäo à populaçäo quanto aos risco no consumo inadequado desse alimento

Characterization of lactose-fermenting Salmonella agona strains isolated in a pediatric unit

Eight lactose-fermenting Salmonella agona strains isolated in a pediatric unit were characterized by classic and molecular methods. The strains were classified as biotypes 1a, corresponding to the most frequen one in Brazil. None of the strains produced colicin. Multiple resistence to antimicrobials was observed among the strains studied, It was demonstrated that the lactose-fermenting character was encoded by a plasmid with spontaneous segregaton at a frequency of 1 percer center. This plasmid was transferable by conjugation at a frequency between 4x10(-8) and 5x10(-10). The lac+ plasmid, which molecular weight was approximately 90 MDa, encoded both lactose fermentation and multiple resistance to antimicrobials. Replicon typing showed that this plasmid did not belong to the known types, suggesting the present of a new replicon type. Classic methods showed that the studied strains had the same characteristics as the clone widely occurring in our area, differing only by lactose-fermenting ability. This conclusion was supported by the results of ribotyping study.