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)

Clonal relatedness and resistance patterns of Salmonella Corvallis from poultry carcasses in a Brazilian slaughterhouse.

INTRODUCTION: Salmonella is a major cause of foodborne disease, and poultry products are important contributors to the transmission of this zoonotic pathogen. Although considered to be rare in most countries, Salmonella Corvallis has been reported in specific geographic areas isolated from both human and non-human sources. The aim of this study was to report the occurrence, the antimicrobial resistance profiles including the extended-spectrum beta-lactamase (ESBL) production, and the clonal relatedness of S. Corvallis strains. METHODOLOGY: A total of 132 fragments of poultry carcasses from a slaughterhouse in São Paulo State, Brazil, were collected at different stages of the manufacturing process (post-bleeding, post-plucking, and post-chilling) and analyzed for the presence of Salmonella. Antimicrobial resistance was determined by disc diffusion method and Etest. Clonal relatedness was determined by pulsed-field gel electrophoresis (PFGE). RESULTS: Among the 272 Salmonella strains recovered, fourteen were S. Corvallis. Ten (71.4%) showed ESBL production and resistance to at least three antimicrobial agents. Nalidixic acid resistance and reduced ciprofloxacin susceptibility was verified in four (28.6%) strains. PFGE analyses showed that all the S. Corvallis strains belonged to the same pulsotype. CONCLUSION: This study identified genetically related S. Corvallis strains exhibiting ESBL production and reduced susceptibility to quinolone. The results suggest the need to improve the sanitary conditions in the slaughterhouse. Moreover, from a public health perspective, continuous surveillance on Salmonella is needed to control the dissemination of this important zoonotic pathogen and its resistance determinants.

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%) and DT 193 (18%) and the 60-MDa plasmid was detected in 94.3% and 84.4% of strains, respectively. Genetic diversity was observed among all strains and 90% presented a > 70% similarity through PFGE analysis. These results suggest a close relationship between Salmonella 1,4,[5],12:i:- and Salmonella Typhimurium at the serotype level.

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.

CTX-M-2-producing Salmonella Typhimurium isolated from pediatric patients and poultry in Brazil.

Ten Salmonella enterica serovar Typhimurium isolates producing CTX-M-2 extended-spectrum beta-lactamase were identified from clinical and poultry sources in two distant cities in Brazil between 2003 and 2004. They included two isolates from pediatric patients and eight isolates from poultry or its environment. All isolates exhibited coresistance to non-beta-lactam antimicrobials including tetracycline and trimethoprim/sulfamethoxazole. The CTX-M-2 gene was located on transferable plasmids with sizes between 90 and 170 kb that also carried other resistance determinants in some isolates. By pulsed-field gel electrophoresis, the genetic similarity of the isolates including clinical and poultry ones ranged from 89% to 100%.

Salmonella serovars isolated from humans in São Paulo State, Brazil, 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% 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.

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.

Prevalence of pigs infected by Salmonella Typhimurium at slaughter after an enterocolitis outbreak.

A cross-sectional study was performed to estimate the prevalence of slaughter pigs infected by Salmonella typhimurium after an enterocolitis outbreak in a commercial pig farm, which was characterised by diarrhoea during the growing phase. Anatomopathological and histopathological findings were suggestive of salmonellosis, which was further confirmed by isolation of S. typhimurium from organs and faeces samples from diseased animals. Ileocolic lymph nodes were aseptically collected from 43 pigs during slaughter procedures. The estimated prevalence of Salmonella-infected pigs was 53.48% [confidence interval (CI): 42.94:64.02%]. This finding demonstrates that the carriage of S. typhimurium at slaughter might be high if pigs originate from a batch previously affected by Salmonella-enterocolitis outbreak at the pre-harvest pork production chain.

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. are the etiologic agents of salmonellosis, a worldwide spread zoonoses causing foodborne outbreaks and clinical diseases. By serological identification, Salmonella enterica subsp. enterica serotype 1,4,[5],12:i:- accounted for 8.8% of human and 1.6% of nonhuman Salmonella strains isolated in São Paulo State, during 1991-2000. A total of 28.6% of them amplified a fragment corresponding to H:1,2 (flagellar phase two) through PCR analysis and were further assigned as S. Typhimurium. Antimicrobial resistance was detected in 36.3% of the 369 PCR-negative strains tested, including the multiresistance to ampicillin, chloramphenicol, sulfonamides, tetracycline, and streptomycin.

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.

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% being classified as phage type 4, 32.43% as phage type 4a, 3.60% as phage type 6a and 0.90% as phage type 7, whereas 5.40% 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.

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% 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% 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%. 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.

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

Prevalence and antimicrobial susceptibility of Salmonella serotypes in patients from Ribeirão Preto, São 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 Ribeirão Preto, São Paulo, Brazil, were studied. The most frequently detected serotypes were Salmonella enterica subspecies enterica serotype 4,5,12:i:- (S. I 4,5,12:i:) (21.2%), S. agona (15.8%) and S. enteritidis (11.3%). A changing pattern of Salmonella serotypes was observed between 1985-1999. S. agona, which represented 27% of Salmonella serotypes isolated from 1985-1989, declined to 4% during the period from 1995 to 1999. S. enteritidis isolation remained below 1% until 1989; rose to 5.9% between 1990 and 1994, and increased to 32.3% 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 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 serotypes isolated from nonhuman sources in São Paulo, Brazil, from 1996 through 2000.

A total of 4,581 Salmonella strains isolated from nonhuman sources, including foodstuffs associated with foodborne Salmonella outbreaks, from January 1996 through December 2000 were serotyped at the Enteropathogens Laboratory, Instituto Adolfo Lutz, São Paulo, Brazil. Among the 123 different serotypes identified, Salmonella enterica subsp. enterica serotype Enteritidis (Salmonella Enteritidis) was the most prevalent (32.7%), ranking first for almost every kind of source. The next most common serotypes were Salmonella Senftenberg (10.3%), Salmonella Hadar (6.8%), Salmonella Agona (5.1%), and Salmonella Typhimurium (2.4%). Rough strains belonging to the subspecies S. enterica subsp. enterica (4.8%), S. enterica subsp. arizonae (<1%), S. enterica subsp. diarizonae (<1%), and S. enterica subsp. houtenae (<1%) were also detected. Foodstuffs (including poultry meat for consumption) contained 38.1% of the studied Salmonella strains, poultry flocks (from several farms under salmonellosis control by the owners) contained 21.7%, the environment contained 10.6%, sewage contained 9.4%, water contained 6.6%, animal feed contained 4.4%, chill water from poultry-processing operations contained 2.2%, and other sources contained 7.0%. Foodstuffs extensively contaminated with Salmonella strains were poultry meat (40%), cow meat (11%), desserts (8%), mayonnaise (6%), sausage (5%), and unpasteurized shell eggs (4%), and there were several other food sources (26%). Homemade mayonnaise was the most common vehicle for Salmonella foodborne outbreaks, and Salmonella Enteritidis was the serotype most isolated (95%) from that source. According to these data and previously published data concerning Salmonella strains isolated in São Paulo State, almost the same serotypes have predominated among nonhuman sources for the last decade.

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)