Epidemiological and pathological aspects of salmonellosis in cattle in southern Brazil / Aspectos epidemiológicos e patológicos de salmonelose em bovinos no Sul do Brasil

Salmonellosis is a bacterial disease that affects several domestic animal species, and is commonly diagnosed in cattle, horses, and pigs. This study aimed to describe the epidemiological and pathological findings of eleven cases of enteric salmonellosis and two cases of salmonellosis with pulmonary involvement in cattle in Rio Grande do Sul State, Brazil. Clinical signs included fever, yellow diarrhea, sometimes with blood streaks, and dyspnea, with a clinical course ranging from 1 to 30 days. Eight cases occurred as outbreaks, whereas five cases occurred individually. Risk factors included inadequate handling practices, such as overcrowded facilities and comorbidities, including anaplasmosis. The main gross finding of the enteric presentation was fibrinonecrotic enterocolitis, occasionally associated with button ulcers, mesenteric lymphadenomegaly, splenomegaly, cholecystitis and hepatomegaly. In addition, one steer with a chronic clinical progression presented severe segmental thickening of the ileum, associated with intestinal rupture and peritonitis. In the respiratory system, the main findings were reddened, non-collapsed lungs, with multifocal areas of atelectasis. The main microscopic findings were observed in the small and large intestines, and these were characterized by severe necrosis and mucosal ulceration, associated with marked inflammatory infiltrate of neutrophils and fibrin deposition intermixed by rod-shaped bacterial aggregates, and fibrosis, as well as interstitial pneumonia. Seven cases yielded positive bacterial cultures for Salmonella spp. and three serovars, namely Typhimurium, Dublin, and Panama were identified. All cases exhibited immunolabeling for Salmonella spp. using immunohistochemistry.(AU)

Salmonelose é uma doença bacteriana que afeta inúmeras espécies animais, especialmente os bovinos, os equinos e os suínos. O presente estudo teve como objetivo descrever os aspectos epidemiológicos e patológicos de onze casos de salmonelose entérica e dois de salmonelose pulmonar em bovinos no estado do Rio Grande do Sul, Brasil. Os sinais clínicos incluíram febre, diarreia amarelada, por vezes com estrias de sangue, anorexia, perda de peso e dispneia, com curso clínico que variou de um a 30 dias. Em oito casos, a doença ocorreu em forma de surtos e cinco foram individuais. Identificou-se fatores de risco relacionados ao manejo inadequado com os bovinos, como alta lotação, além de comorbidades associadas, como anaplasmose. Os principais achados macroscópicos da forma entérica consistiram em enterocolite fibrinonecrótica, por vezes associada a formação de úlceras botonosas, linfonodos mesentéricos e baço aumentados, colecistite e hepatomegalia. Ainda, um bovino com quadro clínico crônico apresentou acentuado espessamento segmentar da parede do íleo associado a ruptura intestinal e peritonite. Na forma respiratória, os principais achados incluíram pulmões não colabados, avermelhados, com áreas multifocais de atelectasia. Os principais achados microscópicos foram observados no intestino delgado e grosso e foram caracterizados por acentuada necrose e ulceração da mucosa, associada a acentuado infiltrado inflamatório de neutrófilos e deposição de fibrina entremeada por agregados bacterianos cocobacilares e fibrose, além de pneumonia intersticial. Sete casos foram positivos para Salmonella sp. no cultivo bacteriano, com identificação dos sorovares Typhimurium, Dublin e Panama. Ao exame imuno-histoquímico para Salmonella sp. todos os casos apresentaram marcação positiva nos órgãos avaliados.(AU)

Extended Spectrum Beta-Lactamase Production and Biofilm Formation in Salmonella Serovars Resistant to Antimicrobial Agents

Antimicrobial resistance is a serious public health problem and Salmonella spp. is highly resistant to antimicrobial agents. Biofilms are important in the food industry due to their formation on products, utensils, and surfaces and the difficulty in their removal. The objective of this study was to assess extended spectrum beta-lactamase (ESBL) production, antimicrobial resistance, and biofilm production of Salmonella isolated from poultry slaughterhouses. Antimicrobial susceptibility was assessed by the disk diffusion assay and ESBL by double diffusion disk assay using the beta-lactamase inhibitor (amoxicillin+clavulanate). The antimicrobials tested were: ampicillin, amoxicillin+clavulanate, aztreonam, ceftazidime, cefotaxime, chloramphenicol, gentamicin, enrofloxacin, sulfonamide, and tetracycline. Serovars Infantis, Panamá, and Tennessee were found to produce ESBL. All serovars were sensitive to tetracycline, and S. Brandenburg was sensitive to all drugs tested. Serovars Panamá, Anatum, Infantis, and Schwarzengrund were moderate biofilm producers at 3 ºC and 9 ºC±1 ºC, respectively, showing possible adaptation of these serovars to these temperatures. Antimicrobials should be used with caution because of the levels of resistance observed and because of ESBL production, and hygiene and sanitary measures should be enhanced to minimize the adhesion of biofilm-forming Salmonella serovars at refrigeration temperatures.(AU)

Extended Spectrum Beta-Lactamase Production and Biofilm Formation in Salmonella Serovars Resistant to Antimicrobial Agents

Antimicrobial resistance is a serious public health problem and Salmonella spp. is highly resistant to antimicrobial agents. Biofilms are important in the food industry due to their formation on products, utensils, and surfaces and the difficulty in their removal. The objective of this study was to assess extended spectrum beta-lactamase (ESBL) production, antimicrobial resistance, and biofilm production of Salmonella isolated from poultry slaughterhouses. Antimicrobial susceptibility was assessed by the disk diffusion assay and ESBL by double diffusion disk assay using the beta-lactamase inhibitor (amoxicillin+clavulanate). The antimicrobials tested were: ampicillin, amoxicillin+clavulanate, aztreonam, ceftazidime, cefotaxime, chloramphenicol, gentamicin, enrofloxacin, sulfonamide, and tetracycline. Serovars Infantis, Panamá, and Tennessee were found to produce ESBL. All serovars were sensitive to tetracycline, and S. Brandenburg was sensitive to all drugs tested. Serovars Panamá, Anatum, Infantis, and Schwarzengrund were moderate biofilm producers at 3 ºC and 9 ºC±1 ºC, respectively, showing possible adaptation of these serovars to these temperatures. Antimicrobials should be used with caution because of the levels of resistance observed and because of ESBL production, and hygiene and sanitary measures should be enhanced to minimize the adhesion of biofilm-forming Salmonella serovars at refrigeration temperatures.

Diversity and antimicrobial resistance of Salmonella isolated from swines feces and carcasses / Diversidade e resistência aos antimicrobianos de Salmonella isoladas de fezes e carcaças de suínos

The aim of this study was to determine the most frequent Salmonella serovars in swine feces in the farm, piggery’s waiting slaughterhouse and after in their carcasses during slaughter, as well as their antimicrobial resistance profiles. Eighty six strains of Salmonella spp. were used, they were previously isolated from three different lots in different collections. The identification of serovars was done by serotyping and the resistance to antimicrobial agents was determined by disc diffusion. A variety of serovars was observed, and the 86 strains were serologically identified as: 28 (32.55%) S. Typhimurium, 20 (23.26%) S. Agona, 17 (19.77%) S. Infantis, 6 (6.98%) S. Panama, and 15 (17.44%) S. Minnesota. The diversity of serovars indicated that different factors influence the infection of finishing pigs and the persistence of microorganisms in the carcass after slaughter of these animals. More than 50% of the isolates were resistant to nine of the 11 tested antibiotics. The drugs that microorganisms had the highest percentages of sensitivity were sulphazotrim and norfloxacin, 22.1% and 14%, respectively. S. Typhimurium serovar was the most isolated, including in the carcasses, and also showed the largest difference in antimicrobial resistance when compared to other serovars. The profile of multidrug resistance observed in this study highlights to the necessity of a judicious observation of antimicrobial resistance in zoonotic foodborne bacteria.

Objetivou-se determinar os sorovares de Salmonella mais freqüentes em fezes de suínos na granja de terminação, pocilga de espera do frigorífico e em suas carcaças durante o abate, assim como, seus perfis de resistência aos antimicrobianos. Utilizou-se 86 cepas de Salmonella spp previamente isoladas de três lotes diferentes em coletas distintas. A identificação dos sorovares foi realizada por meio de sorotipificação e a resistência aos antimicrobianos foi determinada pela técnica de difusão de discos. Foi observada uma multiplicidade de sorovares, sendo as 86 cepas identificadas sorologicamente como: 28 (32,55%) S. Typhimurium, 20 (23,26%), S. Agona, 17 (19,77%) S. Infantis, 6 (6,98%) S. Panama, e 15 (17,44%) S. Minnesota. A diversidade de sorovares indicou que diferentes fatores influenciam na infecção de suínos em terminação e na persistência do microrganismo na carcaça destes animais após o abate. Mais de 50% dos isolados apresentaram resistência a nove dos 11 antibióticos testados. As drogas as quais os microrganismos apresentaram os maiores percentuais de sensibilidade foram o sulfazotrim e a norfloxacina, 22,1% e 14%, respectivamente. S. Typhimurium foi o sorovar mais isolado, inclusive nas carcaças, e também o que demonstrou maior diferença quanto à resistência aos antimicrobianos, quando comparado aos outros sorovares. O perfil de multirresistência observado neste estudo alerta para a necessidade de vigilância e monitoramento sistemático da resistência aos antimicrobianos em bactérias zoonóticas transmitidas pelos alimentos.

Diversity and antimicrobial resistance of Salmonella isolated from swines feces and carcasses / Diversidade e resistência aos antimicrobianos de Salmonella isoladas de fezes e carcaças de suínos

The aim of this study was to determine the most frequent Salmonella serovars in swine feces in the farm, piggerys waiting slaughterhouse and after in their carcasses during slaughter, as well as their antimicrobial resistance profiles. Eighty six strains of Salmonella spp. were used, they were previously isolated from three different lots in different collections. The identification of serovars was done by serotyping and the resistance to antimicrobial agents was determined by disc diffusion. A variety of serovars was observed, and the 86 strains were serologically identified as: 28 (32.55%) S. Typhimurium, 20 (23.26%) S. Agona, 17 (19.77%) S. Infantis, 6 (6.98%) S. Panama, and 15 (17.44%) S. Minnesota. The diversity of serovars indicated that different factors influence the infection of finishing pigs and the persistence of microorganisms in the carcass after slaughter of these animals. More than 50% of the isolates were resistant to nine of the 11 tested antibiotics. The drugs that microorganisms had the highest percentages of sensitivity were sulphazotrim and norfloxacin, 22.1% and 14%, respectively. S. Typhimurium serovar was the most isolated, including in the carcasses, and also showed the largest difference in antimicrobial resistance when compared to other serovars. The profile of multidrug resistance observed in this study highlights to the necessity of a judicious observation of antimicrobial resistance in zoonotic foodborne bacteria.(AU)

Objetivou-se determinar os sorovares de Salmonella mais freqüentes em fezes de suínos na granja de terminação, pocilga de espera do frigorífico e em suas carcaças durante o abate, assim como, seus perfis de resistência aos antimicrobianos. Utilizou-se 86 cepas de Salmonella spp previamente isoladas de três lotes diferentes em coletas distintas. A identificação dos sorovares foi realizada por meio de sorotipificação e a resistência aos antimicrobianos foi determinada pela técnica de difusão de discos. Foi observada uma multiplicidade de sorovares, sendo as 86 cepas identificadas sorologicamente como: 28 (32,55%) S. Typhimurium, 20 (23,26%), S. Agona, 17 (19,77%) S. Infantis, 6 (6,98%) S. Panama, e 15 (17,44%) S. Minnesota. A diversidade de sorovares indicou que diferentes fatores influenciam na infecção de suínos em terminação e na persistência do microrganismo na carcaça destes animais após o abate. Mais de 50% dos isolados apresentaram resistência a nove dos 11 antibióticos testados. As drogas as quais os microrganismos apresentaram os maiores percentuais de sensibilidade foram o sulfazotrim e a norfloxacina, 22,1% e 14%, respectivamente. S. Typhimurium foi o sorovar mais isolado, inclusive nas carcaças, e também o que demonstrou maior diferença quanto à resistência aos antimicrobianos, quando comparado aos outros sorovares. O perfil de multirresistência observado neste estudo alerta para a necessidade de vigilância e monitoramento sistemático da resistência aos antimicrobianos em bactérias zoonóticas transmitidas pelos alimentos.(AU)

Prevalence and identification of Salmonella spp. in water buffaloes from São Paulo State, Brazil / Prevalência e identificação de Salmonella spp. em búfalos do Estado de São Paulo, Brasil

O objetivo do estudo foi investigar a prevalência de Salmonella spp. em amostras de fezes de búfalos do estado de São Paulo, Brasil, e identificar os sorotipos isolados. Foram examinadas 116 amostras de suabes retais de búfalos das raças Jafarabadi e Murrah, coletadas em triplicata, em seis propriedades rurais localizadas nas regiões Central, Centro-Oeste e Nordeste do estado de São Paulo, Brasil. Para avaliar a presença de Salmonella spp., foram utilizados três diferentes caldos de enriquecimento (caldo selenito cistina, caldo tetrationado Muller-Kauffmann e caldo Rappaport-Vassiliadis) e dois diferentes meios de cultura (ágar verde brilhante modificado e ágar XLT4). Das 116 amostras de suabes retais examinadas, oito amostras (6,90%; 8/116) foram positivas para Salmonella spp., incluindo quatro sorotipos: S. Panama (50%; 4/8), S. Agona (25%; 2/8) , S. Newport (12,5%; 1/8) e S. Saintpaul (12,5%; 1/8), todos isolados de búfalos sem sinais clínicos de salmonelose, indicando a importância dos animais assintomáticos como fonte de infecção para outros animais e seres humanos. Das seis propriedades rurais avaliadas, apenas em duas fazendas (33,3%; 2/6) não foi detectada Salmonella spp. O uso de mais de um caldo de enriquecimento seletivo e de mais de um meio de cultura é indicado para o isolamento de Salmonella.(AU)

Prevalence and identification of Salmonella spp. in water buffaloes from São Paulo State, Brazil / Prevalência e identificação de Salmonella spp. em búfalos do Estado de São Paulo, Brasil

O objetivo do estudo foi investigar a prevalência de Salmonella spp. em amostras de fezes de búfalos do estado de São Paulo, Brasil, e identificar os sorotipos isolados. Foram examinadas 116 amostras de suabes retais de búfalos das raças Jafarabadi e Murrah, coletadas em triplicata, em seis propriedades rurais localizadas nas regiões Central, Centro-Oeste e Nordeste do estado de São Paulo, Brasil. Para avaliar a presença de Salmonella spp., foram utilizados três diferentes caldos de enriquecimento (caldo selenito cistina, caldo tetrationado Muller-Kauffmann e caldo Rappaport-Vassiliadis) e dois diferentes meios de cultura (ágar verde brilhante modificado e ágar XLT4). Das 116 amostras de suabes retais examinadas, oito amostras (6,90%; 8/116) foram positivas para Salmonella spp., incluindo quatro sorotipos: S. Panama (50%; 4/8), S. Agona (25%; 2/8) , S. Newport (12,5%; 1/8) e S. Saintpaul (12,5%; 1/8), todos isolados de búfalos sem sinais clínicos de salmonelose, indicando a importância dos animais assintomáticos como fonte de infecção para outros animais e seres humanos. Das seis propriedades rurais avaliadas, apenas em duas fazendas (33,3%; 2/6) não foi detectada Salmonella spp. O uso de mais de um caldo de enriquecimento seletivo e de mais de um meio de cultura é indicado para o isolamento de Salmonella.(AU)

Salmonella screening in pork slaughter flowchart

The aim of this study was to trace the sources of Salmonella contamination during the pig slaughter flowchart. Ten lots of pigs sent for slaughter were followed (four animals per lot), and two weeks before slaughter they were selected based on the presence or absence of Salmonella in their farm stalls. Stool samples were collected after stunning, and from the surface swabs of the carcass in different parts of the flowchart. Samples were also collected immediately after the animals left the dehairing machine, after opening the abdominal cavity, before the carcass entered the cooling chamber, and from jowl samples. The water samples used in the scalding tank were collected before commencing the slaughter process and after the passage of the animals. For the comparison of band patterns, the isolates were analyzed by rep-PCR. The percentage of isolation was 35.3% after stunning, 17.6% immediately after the animals left the dehairing machine, 17.6% after evisceration, 23.5% before entering the cooling chamber and 5.8% from the jowls. The serotypes obtained were: Senftenberg, Idikan, Typhimurium, Heidelberg, Minnesota, Panama and Salmonella group O:4,5. By repPCR analysis, it was found that Salmonella strains that reached the slaughterhouse in carrier pigs may not be eliminated during processing, thereby making its isolation from the carcasses possible. It was also observed that the strains introduced by animals can infect others in different stages of the slaughter flowchart, thus resulting in cross-contamination.

Salmonella screening in pork slaughter flowchart

The aim of this study was to trace the sources of Salmonella contamination during the pig slaughter flowchart. Ten lots of pigs sent for slaughter were followed (four animals per lot), and two weeks before slaughter they were selected based on the presence or absence of Salmonella in their farm stalls. Stool samples were collected after stunning, and from the surface swabs of the carcass in different parts of the flowchart. Samples were also collected immediately after the animals left the dehairing machine, after opening the abdominal cavity, before the carcass entered the cooling chamber, and from jowl samples. The water samples used in the scalding tank were collected before commencing the slaughter process and after the passage of the animals. For the comparison of band patterns, the isolates were analyzed by rep-PCR. The percentage of isolation was 35.3% after stunning, 17.6% immediately after the animals left the dehairing machine, 17.6% after evisceration, 23.5% before entering the cooling chamber and 5.8% from the jowls. The serotypes obtained were: Senftenberg, Idikan, Typhimurium, Heidelberg, Minnesota, Panama and Salmonella group O:4,5. By repPCR analysis, it was found that Salmonella strains that reached the slaughterhouse in carrier pigs may not be eliminated during processing, thereby making its isolation from the carcasses possible. It was also observed that the strains introduced by animals can infect others in different stages of the slaughter flowchart, thus resulting in cross-contamination.(AU)

Ecotypes and virulence factors of Salmonella spp. detected in shrimp farms in Ceara-Brazil / Ecotipos e fatores de virulência de Salmonella spp. detectadas em fazendas de carcinicultura do Ceará, Brasil

Our objective was to group in ecotypes 12 serovars of Salmonella isolated from shrimp farming environments in the State of Ceara (Northeast Brazil). Grouping was done based on genotypic virulence factors. Two groups based on the similarity of the Box-PCR were identified: a group consisting of three strains (01 S. ser. Madelia serovar and 02 S. ser. enterica subs. houtenae) and another group consisting of nine isolates (02 S. ser. Saintpaul serovars; 03 S. ser. Infantis; 02 S. ser. Panama; 01 S. enterica subs. enterica; and 01 S. enterica subs. houtenae). Distribution pattern of the serovars was not influenced by the origin matrices (water and sediment). Plasmid virulence genes pefA and invA were detected, unrelated to the serovar and environmental origin of the isolates. The presence of virulence genes in the isolates underlines the potential to trigger salmonellosis events via shrimp consumption. Biomonitoring of these sources of contamination should be encouraged as a protective measure, minimizing health risks and economic losses for the industry.(AU)

Nosso objetivo foi agrupar em ecotipos 12 sorovares de Salmonella isolados em ambientes decarcinicultura no Estado do Ceará. O agrupamento foi feito a partir da pesquisa de fatores genotípicos devirulência. Constatou-se a formação de dois grupos baseados na similaridade do Box-PCR: um grupo comtrês estirpes (01 sorovar S. ser. Madelia e 02 sorovares S. enterica subs. houtenae) e outro constituído pornove isolados (02 sorovares S. ser. Saintpaul, 03 sorovares S. ser. Infantis, 02 sorovares S. ser. Panama, 01sorovar S. enterica subs. enterica e 01 sorovar S. enterica subs. houtenae). O padrão de distribuição dos sorovaresnão sofreu influência das matrizes de origem (água e sedimento). Os genes de virulência plasmidial pefA einvA foram detectados independente do sorovar e da origem ambiental dos isolados. A presença dessesgenes de virulência nos isolados de carcinicultura evidencia o potencial para desencadear eventos desalmonelose relacionados ao consumo de camarão. O biomonitoramento dessas fontes de contaminaçãodeve ser incentivado como medida protetiva, minimizando os riscos do ponto de vista sanitário e das perdaseconômicas para o setor da carcinicultura.(AU)