Effect of tolfenamic acid in postpartum gilts and the performance of their piglets / Efeito do ácido tolfenâmico no pós-parto de leitoas e no desempenho da leitegada

Postpartum dysgalactia syndrome (PPDS) is a common disorder affecting sows in intensive production systems. In most cases, hypogalactia is not clearly identified and assumes a subclinical aspect. Therefore, the present study aimed to evaluate the effect of a nonsteroidal anti-inflammatory drug (NSAID) based on tolfenamic acid as a prophylactic treatment for PPDS and the performance of suckling piglets. Gilts (n = 319) were randomly divided into two groups: a tolfenamic acid group (n = 157) and a control (n = 162). The tolfenamic acid group received a single intramuscular injection (1 ml/20 kg of 4% tolfenamic acid) after farrowing, whereas the control group received no treatment. The occurrence of PPDS was confirmed. All piglets (n = 4,466) were weighed at 1, 4, and 18 days of age. All litters were evaluated for weight gain, the occurrence of diarrhea, and mortality between 4 and 18 days of age. PPDS variables were analyzed using logistic regression. Piglet weights were analyzed based on covariance while considering the effects of initial weight and the presence of diarrhea. Tolfenamic acid had no significant effect on the incidence of PPDS. The tolfenamic acid group had a 0.41% lower piglet mortality rate until 18 days of age. Tolfenamic acid administered prophylactically to gilts after farrowing reduced piglet mortality during lactation and promoted weight gain.

A síndrome da disgalactia pós-parto (PPDS) é uma doença comum e importante que afeta as matrizes suínas em sistemas intensivos de produção. Na maioria dos casos, a hipogalactia não é claramente identificada, assumindo um aspecto subclínico. Portanto, o presente estudo teve como objetivo avaliar o efeito de um medicamento anti-inflamatório não esteroide (AINE) baseado em ácido tolfenâmico como tratamento profiláctico para PPDS e o desempenho de leitões em aleitamento. As leitoas (n = 319) foram divididas aleatoriamente em dois grupos de tratamento: um grupo de ácido tolfenâmico (n = 157) e um grupo de controle (n = 162). O grupo tratado recebeu uma única injeção intramuscular (1 ml/20 kg de 4% de ácido tolfenâmico) após o parto, enquanto que o grupo de controle não recebeu nenhum tratamento. A ocorrência de PPDS foi então verificada. Todos os leitões (n = 4466) foram pesados com 1, 4, e 18 dias de idade. Todas as leitegadas foram avaliadas quanto ao ganho de peso, ocorrência de diarreia e mortalidade entre os 4 e 18 dias de idade. As variáveis PPDS foram analisadas através de regressão logística. Os pesos de leitões foram analisados com base na covariância, considerando os efeitos do peso inicial e a presença de diarreia. Não houve efeito significativo do ácido tolfenâmico sobre a ocorrência de PPDS. O grupo do ácido tolfenâmico teve menos 0,41% de mortalidade dos leitões até aos 18 dias de idade. O ácido tolfenâmico administrado profilaticamente nas leitoas após o parto reduziu a mortalidade dos leitões durante a lactação e aumentou o ganho de peso nos leitões.

Evaluation of two strategies for reducing the spread of Salmonella in commercial swine herds during the finishing phase and their incremental cost-effectiveness ratios / Avaliação de duas estratégias para redução da infecção por Salmonella em rebanhos comerciais de suínos na fase de terminação e a razão incremental de custo efetividade

To achieve control of Salmonella contamination in pig carcasses, on-farm measures need to be better understood. Complementary strategies require research not only on their effectiveness but also on their financial impact. In this study, we evaluated the incremental cost-effectiveness ratio of two treatments for reducing Salmonella seroprevalence in commercial swine herds. Pigs treated with a prebiotic or a vaccine were studied and compared with pigs in an untreated control group. Each strategy was applied to three batches of pigs in a commercial integration system; the animals were followed from farrowing to the slaughterhouse, and their serologies upon arrival at finishing farms and before slaughter were evaluated. Additionally, carcass surface contamination was assessed for each strategy. The seroprevalence upon arrival at the finishing farm was lower than 3% in all groups. In the control and vaccine groups, the seroprevalence increased by more than 90 percentage points from the day of arrival at the finishing farm to four days before slaughter. Only the prebiotic treatment yielded a significant effect on preslaughter seroprevalence (a 49 percentage points reduction from that in the control). Carcass contamination was 0% in the prebiotic group, 18.33% in the control group and 29.16% in the vaccine group. Only prebiotics significantly reduced the seroprevalence of Salmonella in the studied herds, and the incremental cost-effectiveness ratio associated with prebiotic use was 1.92 USD to reduce seroprevalence by 10 percentage points per carcass ton.(AU)

Para alcançar controle da contaminação por Salmonella em carcaças suínas, intervenções na produção primária precisam ser melhor compreendidas. Estratégias complementares requerem não só pesquisas acerca da sua efetividade, mas também dos custos implicados no uso de tais tecnologias. Para tanto, foi avaliada a razão de custo-efetividade incremental de dois tratamentos para reduzir a soroprevalência de Salmonella em rebanhos suínos comerciais. O uso de um prebiótico e de uma vacina foram comparados com um controle sem tratamento. Cada estratégia foi aplicada em três lotes de suínos em um sistema comercial de integração. Os animais foram acompanhados da maternidade até o abate e suas sorologias no dia do alojamento na terminação e quatro dias antes do abate foram avaliadas. Também, em cada estratégia, amostras de suabe de carcaça foram coletadas para avaliação da contaminação superficial. A soroprevalência no dia do alojamento na terminação foi menor do que 3% em todos os grupos, sendo que nos grupos controle e vacina a soroprevalência aumentou mais de 90 pontos percentuais quatro dias antes do abate. Apenas o uso do prebiótico levou a um efeito significativo na redução da soroprevalência pré-abate (49 pontos percentuais), quando comparado com o controle. A contaminação das carcaças no grupo prebiótico foi 0%, 18,33% no controle e 29,16 no grupo vacinado. Assim, apenas o prebiótico foi capaz de reduzir a soroprevalência nos rebanhos estudados com razão incremental de custo-efetividade de 1,92 USD para redução de 10 pontos percentuais na soroprevalência por tonelada de carcaça.(AU)

Enumeration, antimicrobial resistance and typing of Salmonella enterica: profile of strains carried in the intestinal contents of pigs at slaughter in Southern Brazil

Background: Despite a strong association between Salmonella isolation and slaughter hygiene, as measured by the Enterobacteriaceae levels on pre-chill carcass surfaces, a high variation in this association was observed between sampling dayswithin the same slaughterhouse. It was hypothesised that in a scenario of high exposure on the farm, batches with a highprevalence of carrier pigs shedding a high number of Salmonella may enhance the risk of contamination on some slaughterdays. Thus, the aim of this study was to assess the profile of Salmonella carried in the intestinal contents of slaughter pigs.Materials, Methods & Results: Ten pig batches slaughtered in a slaughterhouse were investigated for the presence ofSalmonella. From each pig, the following samples were taken: i. blood collected at bleeding; ii. sponges rubbed on thecarcass surface after bleeding and before chilling; iii. fragment of the ileocecal region of the intestine. Serum sampleswere subjected to a ELISA-Typhimurium test. Sponges were investigated for the presence of Salmonella and total aerobicmesophilic (TAM) and Enterobacteriaceae (EC) bacterial counts. Salmonella was enumerated in the intestinal contents.Selected Salmonella strains were subjected to an antimicrobial resistance disk diffusion test, macro-restriction with Xba-I(PFGE) and whole genome sequencing (WGS). From the 50 sampled pigs, 96% were positive in the ELISA-Typhimuriumtest and 64% were Salmonella-positive in the intestinal contents. The amount of Salmonella in the intestinal content sampleswas highly variable, and the mean log of fitted distributions of Salmonella in the batch ranged from -2.97 to 2.25 cfu.g-1.The slaughter process achieved a logarithmic reduction, ranging from 0.64 to 2.35 log cfu.cm-2 for TAM and from 0.55 to2.57 log cfu.cm-2 for EC. Salmonella was isolated from 16% of the carcasses after bleeding; this frequency decreased to8% at the pre-chill...

Enumeration, antimicrobial resistance and typing of Salmonella enterica: profile of strains carried in the intestinal contents of pigs at slaughter in Southern Brazil

Background: Despite a strong association between Salmonella isolation and slaughter hygiene, as measured by the Enterobacteriaceae levels on pre-chill carcass surfaces, a high variation in this association was observed between sampling dayswithin the same slaughterhouse. It was hypothesised that in a scenario of high exposure on the farm, batches with a highprevalence of carrier pigs shedding a high number of Salmonella may enhance the risk of contamination on some slaughterdays. Thus, the aim of this study was to assess the profile of Salmonella carried in the intestinal contents of slaughter pigs.Materials, Methods & Results: Ten pig batches slaughtered in a slaughterhouse were investigated for the presence ofSalmonella. From each pig, the following samples were taken: i. blood collected at bleeding; ii. sponges rubbed on thecarcass surface after bleeding and before chilling; iii. fragment of the ileocecal region of the intestine. Serum sampleswere subjected to a ELISA-Typhimurium test. Sponges were investigated for the presence of Salmonella and total aerobicmesophilic (TAM) and Enterobacteriaceae (EC) bacterial counts. Salmonella was enumerated in the intestinal contents.Selected Salmonella strains were subjected to an antimicrobial resistance disk diffusion test, macro-restriction with Xba-I(PFGE) and whole genome sequencing (WGS). From the 50 sampled pigs, 96% were positive in the ELISA-Typhimuriumtest and 64% were Salmonella-positive in the intestinal contents. The amount of Salmonella in the intestinal content sampleswas highly variable, and the mean log of fitted distributions of Salmonella in the batch ranged from -2.97 to 2.25 cfu.g-1.The slaughter process achieved a logarithmic reduction, ranging from 0.64 to 2.35 log cfu.cm-2 for TAM and from 0.55 to2.57 log cfu.cm-2 for EC. Salmonella was isolated from 16% of the carcasses after bleeding; this frequency decreased to8% at the pre-chill...(AU)

Protection efficacy of the rLTB-R1 chimera against experimental swine mycoplasmal pneumonia

Background: Mycoplasma hyopneumoniae is the etiological agent of the Swine Mycoplasmal Pneumonia (SMP), one ofthe most economically significant diseases in the swine industry worldwide. Commonly used vaccines for SMP controlconsist of inactivated whole cells (bacterins). These vaccines are efficacious against M. hyopneumoniae challenge, but donot prevent colonization by the pathogen or completely eliminate pneumonia. P97 adhesin is conserved in the M. pneumoniae virulent strains, therefore it is an attractive target to be used in recombinant vaccines against M. hyopneumoniae.The aim of the present study was to evaluate protection afforded by rLTB-R1, a recombinant chimera composed by LTBfused with the R1 repeat region of P97 adhesin of M. hyopneumoniae, in specific-pathogen-free (SPF) piglets vaccinatedby intranasal or intramuscular route and challenged with a pathogenic strain of M. hyopneumoniae.Materials, Methods & Results: PCR products of the LTB and R1 coding sequences were fused, then cloned into pETDEST42™ expression vector. The rLTB-R1 was expressed in Escherichia coli BL21 (DE3) Salt induction (SI). The pigletswere divided into three groups: four piglets were intranasally vaccinated with 1 mg of rLTB-R1 solubilized in 1 mL of PBSat 0 and 14 days (IN rLTB-R1 group); four piglets were intramuscularly vaccinated with 1 mg of rLTB-R1 solubilized in 1mL of PBS at 0 and 14 days (IM rLTB-R1 group); three piglets were intranasally and intramuscularly inoculated with 1 mLof PBS (control group). Two weeks after the last immunization (28 day), piglets were intratracheally challenged with 10 mLof a suspension containing 109 color-changing unit (CCU) of pathogenic M. hyopneumoniae 7448 strain on three consecutivedays. Until the challenge (28 days), intranasal and intramuscular vaccination with rLTB-R1 induced seroconversions of antiR1 systemic antibodies of 1.6 and 4.6 ×, respectively. The IN rLTB-R1...(AU)

Protection efficacy of the rLTB-R1 chimera against experimental swine mycoplasmal pneumonia

Background: Mycoplasma hyopneumoniae is the etiological agent of the Swine Mycoplasmal Pneumonia (SMP), one ofthe most economically significant diseases in the swine industry worldwide. Commonly used vaccines for SMP controlconsist of inactivated whole cells (bacterins). These vaccines are efficacious against M. hyopneumoniae challenge, but donot prevent colonization by the pathogen or completely eliminate pneumonia. P97 adhesin is conserved in the M. pneumoniae virulent strains, therefore it is an attractive target to be used in recombinant vaccines against M. hyopneumoniae.The aim of the present study was to evaluate protection afforded by rLTB-R1, a recombinant chimera composed by LTBfused with the R1 repeat region of P97 adhesin of M. hyopneumoniae, in specific-pathogen-free (SPF) piglets vaccinatedby intranasal or intramuscular route and challenged with a pathogenic strain of M. hyopneumoniae.Materials, Methods & Results: PCR products of the LTB and R1 coding sequences were fused, then cloned into pETDEST42™ expression vector. The rLTB-R1 was expressed in Escherichia coli BL21 (DE3) Salt induction (SI). The pigletswere divided into three groups: four piglets were intranasally vaccinated with 1 mg of rLTB-R1 solubilized in 1 mL of PBSat 0 and 14 days (IN rLTB-R1 group); four piglets were intramuscularly vaccinated with 1 mg of rLTB-R1 solubilized in 1mL of PBS at 0 and 14 days (IM rLTB-R1 group); three piglets were intranasally and intramuscularly inoculated with 1 mLof PBS (control group). Two weeks after the last immunization (28 day), piglets were intratracheally challenged with 10 mLof a suspension containing 109 color-changing unit (CCU) of pathogenic M. hyopneumoniae 7448 strain on three consecutivedays. Until the challenge (28 days), intranasal and intramuscular vaccination with rLTB-R1 induced seroconversions of antiR1 systemic antibodies of 1.6 and 4.6 ×, respectively. The IN rLTB-R1...

Genotyping and antimicrobial resistance in Escherichia coli from pig carcasses / Genotipagem e resistência antimicrobiana de Escherichia coli em carcaças suínas

The increasing antimicrobial resistance observed worldwide in bacteria isolated from human and animals is a matter of extreme concern and has led to the monitoring of antimicrobial resistance in pathogenic and commensal bacteria. The aim of this study was to evaluate the antimicrobial resistance profile of Escherichia coli isolated from pig carcasses and to assess the occurrence of relevant resistance genes. A total of 319 E. coli isolates were tested for antimicrobial susceptibility against different antimicrobial agents. Moreover, the presence of extended-spectrum β-lactamase (ESBL) and inducible ampC-β-lactamase producers was investigated. Eighteen multi-resistant strains were chosen for resistance gene detection and PFGE characterization. The study showed that resistance to antimicrobials is widespread in E. coli isolated from pig carcasses, since 86.2% of the strains were resistant to at least one antimicrobial and 71.5% displayed multi-resistance profiles. No ampC-producing isolates were detected and only one ESBL-producing E. coli was identified. Genes strA (n=15), floR (n=14), aac(3)IVa (n=13), tetB (n=13), sul2 (n=12), tetA (n=11), aph(3)Ia (n=8) and sul3 (n=5) were detected by PCR. PFGE analysis of these multi-resistant E. coli strains showed less than 80% similarity among them. We conclude that antimicrobial multi-resistant E. coli strains are common on pig carcasses and present highly diverse genotypes and resistance phenotypes and genotypes.(AU)

O incremento de resistência frente aos antimicrobianos, observado em bactérias isoladas de humanos e animais, tem sido motivo de preocupação mundial e levado ao monitoramento dos perfis de resistência em bactérias patogênicas e comensais. O objetivo desse estudo foi avaliar o perfil de resistência em Escherichia coli isolada de carcaças suínas e descrever a ocorrência de alguns genes de resistência relevantes. Um total de 319 isolados de E. coli foi testado quanto à suscetibilidade frente a diversos antimicrobianos. A presença de isolados produtores de β-lactamases (ESBL) de espectro estendido e β-lactamase induzível do tipo ampC foi também investigada. Dezoito cepas multirresistentes foram escolhidas para investigação de genes de resistência e caracterização por macro-restrição (PFGE). Os resultados demonstraram que a resistência a antimicrobianos está disseminada, pois 86,2% dos isolados de E. coli foram resistentes ao menos a um antimicrobiano e 71,5% apresentaram perfil de multirresistência. Uma cepa de E. coli produtora de ESBL e nenhuma produtora de ampC induzível foram identificadas. Os genes strA (n=15); floR (n=14);aac(3)-IVa (n=13); tetB (n=13); sul2 (n=12); tetA (n=11); aph(3')Ia (n=8); sul3 (n=5) foram detectados por PCR. A análise de PFGE demonstrou que cepas de E. coli multirresistentes apresentaram similaridade inferior a 80% entre si. Concluiu-se que cepas multirresistentes de E. coli são frequentes em carcaças de suínos e apresentam uma alta diversidade genotípica, bem como de fenótipos e genes de resistência.(AU)

Genotyping and antimicrobial resistance in Escherichia coli from pig carcasses / Genotipagem e resistência antimicrobiana de Escherichia coli em carcaças suínas

The increasing antimicrobial resistance observed worldwide in bacteria isolated from human and animals is a matter of extreme concern and has led to the monitoring of antimicrobial resistance in pathogenic and commensal bacteria. The aim of this study was to evaluate the antimicrobial resistance profile of Escherichia coli isolated from pig carcasses and to assess the occurrence of relevant resistance genes. A total of 319 E. coli isolates were tested for antimicrobial susceptibility against different antimicrobial agents. Moreover, the presence of extended-spectrum β-lactamase (ESBL) and inducible ampC-β-lactamase producers was investigated. Eighteen multi-resistant strains were chosen for resistance gene detection and PFGE characterization. The study showed that resistance to antimicrobials is widespread in E. coli isolated from pig carcasses, since 86.2% of the strains were resistant to at least one antimicrobial and 71.5% displayed multi-resistance profiles. No ampC-producing isolates were detected and only one ESBL-producing E. coli was identified. Genes strA (n=15), floR (n=14), aac(3)IVa (n=13), tetB (n=13), sul2 (n=12), tetA (n=11), aph(3)Ia (n=8) and sul3 (n=5) were detected by PCR. PFGE analysis of these multi-resistant E. coli strains showed less than 80% similarity among them. We conclude that antimicrobial multi-resistant E. coli strains are common on pig carcasses and present highly diverse genotypes and resistance phenotypes and genotypes.(AU)

O incremento de resistência frente aos antimicrobianos, observado em bactérias isoladas de humanos e animais, tem sido motivo de preocupação mundial e levado ao monitoramento dos perfis de resistência em bactérias patogênicas e comensais. O objetivo desse estudo foi avaliar o perfil de resistência em Escherichia coli isolada de carcaças suínas e descrever a ocorrência de alguns genes de resistência relevantes. Um total de 319 isolados de E. coli foi testado quanto à suscetibilidade frente a diversos antimicrobianos. A presença de isolados produtores de β-lactamases (ESBL) de espectro estendido e β-lactamase induzível do tipo ampC foi também investigada. Dezoito cepas multirresistentes foram escolhidas para investigação de genes de resistência e caracterização por macro-restrição (PFGE). Os resultados demonstraram que a resistência a antimicrobianos está disseminada, pois 86,2% dos isolados de E. coli foram resistentes ao menos a um antimicrobiano e 71,5% apresentaram perfil de multirresistência. Uma cepa de E. coli produtora de ESBL e nenhuma produtora de ampC induzível foram identificadas. Os genes strA (n=15); floR (n=14);aac(3)-IVa (n=13); tetB (n=13); sul2 (n=12); tetA (n=11); aph(3')Ia (n=8); sul3 (n=5) foram detectados por PCR. A análise de PFGE demonstrou que cepas de E. coli multirresistentes apresentaram similaridade inferior a 80% entre si. Concluiu-se que cepas multirresistentes de E. coli são frequentes em carcaças de suínos e apresentam uma alta diversidade genotípica, bem como de fenótipos e genes de resistência.(AU)

Detection of genotipically related multi-resistant Escherichia coli isolates in pig feces and carcasses / Detecção de isolados Escherichia coli multirresistentes e genotipicamente relacionados em fezes e carcaças suínas

Background: Antimicrobial resistant bacteria are considered a hazard not only for the treatment of animal diseases but also for public health. Commensal bacteria, such as Escherichia coli are considered a good indicator of antimicrobial resistance in the population, because it is a gut inhabitant and thus undergoes constant pressure of selection by the administration of antimicrobials. Regarding the public health, it is important to evaluate if resistant bacteria carried in the intestinal content of slaughter pigs can be found on the surface of pre chill carcasses. Therefore, the aims of this study were to evaluate the frequency of antimicrobial resistance in E. coli isolated from feces and pig carcasses; and to assess if multi-resistant isolates from both sources were phenotypically and genotypically related. Materials, Methods & Results: Two sampling cycles were conducted in three pig slaughterhouses (A, B and C). In each cycle, samples were collected form: i. feces deposited on the pen floor of the lairage; ii. surface of carcasses at the prechill step. Samples were submitted to a protocol of isolation and confirmation of Escherichia coli. Isolates were grouped according to the origin: feces (n = 355); carcasses (n = 319); and evaluated for antimicrobial resistance by agar diffusion test. Ninety two isolates presenting multidrug resistance profile were analyzed by pulsed [...]

Detection of genotipically related multi-resistant Escherichia coli isolates in pig feces and carcasses / Detecção de isolados Escherichia coli multirresistentes e genotipicamente relacionados em fezes e carcaças suínas

Background: Antimicrobial resistant bacteria are considered a hazard not only for the treatment of animal diseases but also for public health. Commensal bacteria, such as Escherichia coli are considered a good indicator of antimicrobial resistance in the population, because it is a gut inhabitant and thus undergoes constant pressure of selection by the administration of antimicrobials. Regarding the public health, it is important to evaluate if resistant bacteria carried in the intestinal content of slaughter pigs can be found on the surface of pre chill carcasses. Therefore, the aims of this study were to evaluate the frequency of antimicrobial resistance in E. coli isolated from feces and pig carcasses; and to assess if multi-resistant isolates from both sources were phenotypically and genotypically related. Materials, Methods & Results: Two sampling cycles were conducted in three pig slaughterhouses (A, B and C). In each cycle, samples were collected form: i. feces deposited on the pen floor of the lairage; ii. surface of carcasses at the prechill step. Samples were submitted to a protocol of isolation and confirmation of Escherichia coli. Isolates were grouped according to the origin: feces (n = 355); carcasses (n = 319); and evaluated for antimicrobial resistance by agar diffusion test. Ninety two isolates presenting multidrug resistance profile were analyzed by pulsed [...](AU)

Assessment of different cut-off values of the ELISA-Typhimurium for the discrimination of swine herds with Salmonella isolation / Avaliação de diferentes pontos de corte no teste de ELISA para discriminação de lotes de suínos com isolamento de Salmonella sp

Salmonella control programs require the classification of positive herds according with the prevalence of infected pigs. This must be based on diagnostic methods that are reliable, accurate and cost effective. Since serological methods fulfill most of these prerequisites, many countries have adopted indirect ELISA tests to discriminate herds, based on their seroprevalence. In view of that, an in-house indirect ELISA test (ELISA-Typhimurium) previously developed proved to be able to detect sera antibodies against the most prevalent serovars of Salmonella found in Brazilian pig farms. This study aimed to assess different cut-off values of the ELISA-Typhimurium in terms of their correlation with Salmonella isolation results at the herd level. Blood and mesenteric lymph node or rectal swabs were taken from 56 slaughter and 14 grower batches from different farms. Serum was tested using the ELISA-Typhimurium at different cut-off points (OD: 6.87%-40%). A total of 55 slaughter batches had at least one Salmonella-positive sample, and the within-herd prevalence was 64.9% (SE±24.8). All 14-grower batches were negative on Salmonella isolation. The logistic regression demonstrated that at 20% OD the ELISA-Typhimurium test is the best model to predict Salmonella isolation frequency at the herd level. At this cut-off point, the test may be a helpful tool for discriminating Salmonella infected herds.

Os programas de controle de Salmonella requerem a classificação de rebanhos de acordo com a prevalência de suínos infectados. Isto deve ser baseado em métodos de diagnóstico confiáveis, acurados e econômicos. Como os métodos sorológicos atendem estes pré-requisitos, muitos países têm adotado o teste de ELISA indireto na discriminação dos rebanhos, baseado na soroprevalência. Em vista disto, um teste de ELISA indireto (ELISA-Typhimurium) previamente desenvolvido demonstrou ser capaz de detectar anticorpos contra os sorovares de Salmonella mais prevalentes em granjas de suínos no Brasil. O presente estudo objetivou testar diferentes pontos de corte do teste ELISA-Typhimurium em termos de sua correlação com os resultados de isolamento de Salmonella na granja. Sangue e linfonodos mesentéricos ou suabes fecais foram colhidos de suínos pertencentes a 56 lotes de abate e 14 lotes de crescimento em diferentes granjas. O soro foi testado no ELISA-Typhimurium em diferentes pontos de corte (DO: 6,87%-40%). Um total de 55 lotes de abate testados apresentaram pelo menos uma amostra com isolamento de Salmonella, e a prevalência intra-lote foi de 64,9% (EP±24,8). Todos os lotes de crescimento foram negativos no isolamento de Salmonella. O modelo de regressão demostrou que a DO20% é o melhor modelo para predizer a frequência de isolamento de Salmonella em lotes de suínos. Nesse ponto de corte, o teste poderá ser uma ferramenta útil para discriminar lotes suínos infectados por Salmonella.

Assessment of different cut-off values of the ELISA-Typhimurium for the discrimination of swine herds with Salmonella isolation / Avaliação de diferentes pontos de corte no teste de ELISA para discriminação de lotes de suínos com isolamento de Salmonella sp

Salmonella control programs require the classification of positive herds according with the prevalence of infected pigs. This must be based on diagnostic methods that are reliable, accurate and cost effective. Since serological methods fulfill most of these prerequisites, many countries have adopted indirect ELISA tests to discriminate herds, based on their seroprevalence. In view of that, an in-house indirect ELISA test (ELISA-Typhimurium) previously developed proved to be able to detect sera antibodies against the most prevalent serovars of Salmonella found in Brazilian pig farms. This study aimed to assess different cut-off values of the ELISA-Typhimurium in terms of their correlation with Salmonella isolation results at the herd level. Blood and mesenteric lymph node or rectal swabs were taken from 56 slaughter and 14 grower batches from different farms. Serum was tested using the ELISA-Typhimurium at different cut-off points (OD: 6.87%-40%). A total of 55 slaughter batches had at least one Salmonella-positive sample, and the within-herd prevalence was 64.9% (SE±24.8). All 14-grower batches were negative on Salmonella isolation. The logistic regression demonstrated that at 20% OD the ELISA-Typhimurium test is the best model to predict Salmonella isolation frequency at the herd level. At this cut-off point, the test may be a helpful tool for discriminating Salmonella infected herds.

Os programas de controle de Salmonella requerem a classificação de rebanhos de acordo com a prevalência de suínos infectados. Isto deve ser baseado em métodos de diagnóstico confiáveis, acurados e econômicos. Como os métodos sorológicos atendem estes pré-requisitos, muitos países têm adotado o teste de ELISA indireto na discriminação dos rebanhos, baseado na soroprevalência. Em vista disto, um teste de ELISA indireto (ELISA-Typhimurium) previamente desenvolvido demonstrou ser capaz de detectar anticorpos contra os sorovares de Salmonella mais prevalentes em granjas de suínos no Brasil. O presente estudo objetivou testar diferentes pontos de corte do teste ELISA-Typhimurium em termos de sua correlação com os resultados de isolamento de Salmonella na granja. Sangue e linfonodos mesentéricos ou suabes fecais foram colhidos de suínos pertencentes a 56 lotes de abate e 14 lotes de crescimento em diferentes granjas. O soro foi testado no ELISA-Typhimurium em diferentes pontos de corte (DO: 6,87%-40%). Um total de 55 lotes de abate testados apresentaram pelo menos uma amostra com isolamento de Salmonella, e a prevalência intra-lote foi de 64,9% (EP±24,8). Todos os lotes de crescimento foram negativos no isolamento de Salmonella. O modelo de regressão demostrou que a DO20% é o melhor modelo para predizer a frequência de isolamento de Salmonella em lotes de suínos. Nesse ponto de corte, o teste poderá ser uma ferramenta útil para discriminar lotes suínos infectados por Salmonella.(AU)

Antimicrobial resistance of Enterococcus isolated from pre-chill swine carcasses

Background: As a result of the extensive use of antimicrobials in agriculture, animals have been implicated as possible reservoirs of resistant strains of bacteria. Enterococci are members of the normal flora of the gastrointestinaltract of human and animals. Because of their ubiquity, enterococci have been introduced in programs to evaluate thehazard of transmission of resistant bacterial strains through the food chain. The aim of this study was to assess theantimicrobial resistance profile of Enterococcus isolated from swine carcasses at the pre-chill step of processing.Material, Methods & Results: Pig carcasses were sampled at three commercial slaughterhouses (A, B and C). Oneach of two sampling occasions swabs of 100 cm2 areas were taken from each ham, back, belly and jowl of a total of14 pre-chill carcasses. Enterococci were isolated and counted in KF Streptococcus Agar, and typical colonies wereconfirmed by PCR assay targeting the tuf gene. Enterococcus isolates were tested for susceptibility to nine differentantimicrobial agents by agar disc diffusion. From a total of 252 carcasses sampled, 240 (95.2%) presented presumptivecolonies of Enterococcus in counts ranging from 0.02 log CFU.cm-2 to 2.9 log CFU.cm-2. All isolates were confirmedas belonging to the genus Enterococcus, and the great majority was identified as E. faecalis (218/240; 90.83%). Half(125/240; 52.1%) of the Enterococcus isolates were susceptible to all tested antimicrobials. No resistance to ampicillin, vancomycin or teicoplanin was found. The most frequent resistance was to tetracycline (42.5%), followed byerythromycin (26.7%), high level (HLR) streptomycin (20.4%), ciprofloxacin (13.8%), chloramphenicol (12.1%)and HLR-gentamicin (10.4%). Among the 115 resistant Enterococcus isolates, 55 (47.8%) were multi-resistant, andthe distribution of the most common profiles was related to the slaughterhouse...(AU)

Antimicrobial resistance of Enterococcus isolated from pre-chill swine carcasses

Background: As a result of the extensive use of antimicrobials in agriculture, animals have been implicated as possible reservoirs of resistant strains of bacteria. Enterococci are members of the normal flora of the gastrointestinaltract of human and animals. Because of their ubiquity, enterococci have been introduced in programs to evaluate thehazard of transmission of resistant bacterial strains through the food chain. The aim of this study was to assess theantimicrobial resistance profile of Enterococcus isolated from swine carcasses at the pre-chill step of processing.Material, Methods & Results: Pig carcasses were sampled at three commercial slaughterhouses (A, B and C). Oneach of two sampling occasions swabs of 100 cm2 areas were taken from each ham, back, belly and jowl of a total of14 pre-chill carcasses. Enterococci were isolated and counted in KF Streptococcus Agar, and typical colonies wereconfirmed by PCR assay targeting the tuf gene. Enterococcus isolates were tested for susceptibility to nine differentantimicrobial agents by agar disc diffusion. From a total of 252 carcasses sampled, 240 (95.2%) presented presumptivecolonies of Enterococcus in counts ranging from 0.02 log CFU.cm-2 to 2.9 log CFU.cm-2. All isolates were confirmedas belonging to the genus Enterococcus, and the great majority was identified as E. faecalis (218/240; 90.83%). Half(125/240; 52.1%) of the Enterococcus isolates were susceptible to all tested antimicrobials. No resistance to ampicillin, vancomycin or teicoplanin was found. The most frequent resistance was to tetracycline (42.5%), followed byerythromycin (26.7%), high level (HLR) streptomycin (20.4%), ciprofloxacin (13.8%), chloramphenicol (12.1%)and HLR-gentamicin (10.4%). Among the 115 resistant Enterococcus isolates, 55 (47.8%) were multi-resistant, andthe distribution of the most common profiles was related to the slaughterhouse...

Avaliação microbiológica e físico-química de pernis suínos tratados com ácidos orgânicos e/ou vapor no controle da contaminação superficial por Salmonella Typhimurium / Microbiological and physico-chemical evaluation of pork leg treated with organic acids and/or steam under pressure in the control of surface contamination by Salmonella Typhimurium

Suínos portadores assintomáticos são o principal fator de risco para a contaminação de carcaças durante o processamento industrial. Diferentes formas de prevenção e controle têm sido testadas no pós abate, dentre elas o uso de vapor e/ou ácidos orgânicos, que podem ser alternativas de baixo custo e alta eficiência. No presente estudo, testou-se o uso de solução de ácidos orgânicos e aplicação de vapor sob pressão, usados isoladamente ou em associação. Como poucas pesquisas trazem informações sobre o fato desses tratamentos promoverem ou não mudanças nas características físico-químicas da carne suína, o presente experimento se propôs também a avaliar as possíveis alterações físico-químicas de pernis submetidos a esses tratamentos. Porções de pernil foram contaminadas artificialmente com Salmonella Typhimurium DT 177 e, posteriormente, divididas em quatro tratamentos: imersão em solução fisiológica por 5 segundos (controle, T1); imersão em solução fisiológica acrescida de ácidos orgânicos 1000 ppm por 5 segundos (T2); aspersão de vapor sob pressão de 4 bar à temperatura de 140ºC (T3); e T3 seguido por T2 (T4). Após o tratamento, uma área de 100cm2 foi amostrada por meio de swab para quantificação da Salmonella residual pela técnica do número mais provável (NMP). Foram avaliados também o aspecto, coloração, consistência e odor, antes e após cada tratamento dos pernis, bem como análises físico-químicas visando à determinação do percentual de lipídeos, proteínas, pH, umidade e voláteis, também antes e após cada tratamento. Observou-se que o uso de vapor associado à imersão em solução de ácidos orgânicos a 1000 ppm apresentou melhor eficiência na redução das contaminações superficiais (100% de frequência de redução), porém a melhor eficácia foi observada através da redução de 0,8 log base 10 do NMP na pele e 0,77 log base 10 do NMP na musculatura através do uso de solução fisiológica (T1) e solução de ácidos orgânicos (T2), respectivamente. Os resultados [...].

Asymptomatic carrier pigs are the main risk factor for carcass contamination during the slaughter. Several post-slaughter prevention programs have been tested, such as organic acids and steam under pressure. These alternatives show low cost and high efficiency. This study tested the use of organic acid solutions and steam, in isolated tests and its associations. This experiment also evaluated the physical-chemistry features of the pork. Forty pork legs were contaminated with Salmonella Typhimurium DT 177 and subsequently divided into 4 treatments: immersion in physiological solution for 5 seconds (control, T1); immersion in physiological solution with 1000 ppm of organic acids for 5 seconds (T2); sprinkling of steam under pressure (4 bar) at 140ºC (T3); and T2 after T3 (T4). An area of 100cm2 was sampled through superficial swabs for Salmonella counts by Most Probable Number method (MPN). Aspect, color, consistency, smell, and levels of fat, protein, pH, and moisture were also evaluated before and after each treatment. The use of steam associated to the immersion in organic acid solution showed better efficiency for reduction of superficial contamination (decreasing 100% of counts) but the better effectiveness was observed through the decreasing of 0.8 log of MPN at skin and 0.77 log of MPN at muscle by using the physiological solution (T1) and the organic acid solution (T2), respectively. The steam treatment associated with the organic acid solutions (T4) decreased the pH and increased moisture of pork legs, although it did not mischaracterize the quality (within required parameters for human consumption). All the other treatments did not change physical-chemistry fefatures.

Avaliação microbiológica e físico-química de pernis suínos tratados com ácidos orgânicos e/ou vapor no controle da contaminação superficial por Salmonella Typhimurium / Microbiological and physico-chemical evaluation of pork leg treated with organic acids and/or steam under pressure in the control of surface contamination by Salmonella Typhimurium

Suínos portadores assintomáticos são o principal fator de risco para a contaminação de carcaças durante o processamento industrial. Diferentes formas de prevenção e controle têm sido testadas no pós abate, dentre elas o uso de vapor e/ou ácidos orgânicos, que podem ser alternativas de baixo custo e alta eficiência. No presente estudo, testou-se o uso de solução de ácidos orgânicos e aplicação de vapor sob pressão, usados isoladamente ou em associação. Como poucas pesquisas trazem informações sobre o fato desses tratamentos promoverem ou não mudanças nas características físico-químicas da carne suína, o presente experimento se propôs também a avaliar as possíveis alterações físico-químicas de pernis submetidos a esses tratamentos. Porções de pernil foram contaminadas artificialmente com Salmonella Typhimurium DT 177 e, posteriormente, divididas em quatro tratamentos: imersão em solução fisiológica por 5 segundos (controle, T1); imersão em solução fisiológica acrescida de ácidos orgânicos 1000 ppm por 5 segundos (T2); aspersão de vapor sob pressão de 4 bar à temperatura de 140ºC (T3); e T3 seguido por T2 (T4). Após o tratamento, uma área de 100cm2 foi amostrada por meio de swab para quantificação da Salmonella residual pela técnica do número mais provável (NMP). Foram avaliados também o aspecto, coloração, consistência e odor, antes e após cada tratamento dos pernis, bem como análises físico-químicas visando à determinação do percentual de lipídeos, proteínas, pH, umidade e voláteis, também antes e após cada tratamento. Observou-se que o uso de vapor associado à imersão em solução de ácidos orgânicos a 1000 ppm apresentou melhor eficiência na redução das contaminações superficiais (100% de frequência de redução), porém a melhor eficácia foi observada através da redução de 0,8 log base 10 do NMP na pele e 0,77 log base 10 do NMP na musculatura através do uso de solução fisiológica (T1) e solução de ácidos orgânicos (T2), respectivamente. Os resultados [...].(AU)

Asymptomatic carrier pigs are the main risk factor for carcass contamination during the slaughter. Several post-slaughter prevention programs have been tested, such as organic acids and steam under pressure. These alternatives show low cost and high efficiency. This study tested the use of organic acid solutions and steam, in isolated tests and its associations. This experiment also evaluated the physical-chemistry features of the pork. Forty pork legs were contaminated with Salmonella Typhimurium DT 177 and subsequently divided into 4 treatments: immersion in physiological solution for 5 seconds (control, T1); immersion in physiological solution with 1000 ppm of organic acids for 5 seconds (T2); sprinkling of steam under pressure (4 bar) at 140ºC (T3); and T2 after T3 (T4). An area of 100cm2 was sampled through superficial swabs for Salmonella counts by Most Probable Number method (MPN). Aspect, color, consistency, smell, and levels of fat, protein, pH, and moisture were also evaluated before and after each treatment. The use of steam associated to the immersion in organic acid solution showed better efficiency for reduction of superficial contamination (decreasing 100% of counts) but the better effectiveness was observed through the decreasing of 0.8 log of MPN at skin and 0.77 log of MPN at muscle by using the physiological solution (T1) and the organic acid solution (T2), respectively. The steam treatment associated with the organic acid solutions (T4) decreased the pH and increased moisture of pork legs, although it did not mischaracterize the quality (within required parameters for human consumption). All the other treatments did not change physical-chemistry fefatures.(AU)

Detecção de Salmonella enterica e Listeria monocytogenes em carcaças suínas na etapa de pré-resfriamento / Salmonella enterica and Listeria monocytogenes detection on pre-chill pig carcasses

Background: Salmonellosis is one of the most prevalent foodborne diseases worldwide. Although listeriosis has been quite less reported, it is considered a major public health hazard due to the severity of symptoms caused in humans. Previous studies demonstrated that the genus Listeria and Salmonella can be found infecting pigs in Brazil, however there are yet few reports about their isolation from carcasses after the slaughtering process. From this, the aims of this study were to investigate the presence of Salmonella enterica and Listeria monocytogenes on pre-chill pig carcasses and to evaluate the presence of fecal carriers at the lairage. Materials, Methods & Results: Two sampling events were conducted in each of three slaughterhouses located in the state of Santa Catarina, Brazil. In each sampling event, pen feces from pigs belonging to three slaughter batches originated from different farms were collected. Thereafter, swabs were taken on the surface (loin, jowls, belly and ham) of 42 carcasses belonging to the same pig batches sampled at the lairage. All samples were submitted to a protocol for isolation of S. enterica and L. monocytogenes. Moreover, coliforms were enumerated in the samples taken from the carcasses. From a total of 18 samples of pen feces, 83.3% (15/18) were positive for S. enterica. The genus Listeria was isolated from 66.7% (12/18) of pen feces samples, but only one isolate was confirmed as L. monocytogenes. Among the 252 pre-chill carcasses sampled, S. enterica was isolated from 27.4% (69/252); and S. Typhimurium was the most frequent serovar identified. On the other hand, L. monocytogenes was detected in 19.8% (50/252) of the carcasses. In slaughterhouse B, a signifi cantly higher frequency (P < 0.001) of L. monocytogenes isolation than in the other slaughterhouses was observed. S. enterica was significantly more (P < 0.001) isolated than L. monocytogenes in the other two sampled slaughterhouses. The coliform mean counts found on carcass samples ranged from 1.25 x 100 to 8.25 x 104. In slaughterhouse A, the coliform mean was significantly lower (P < 0.001) than the mean of coliforms determined in the other slaughterhouses. Discussion: The significantly higher frequency of L. monocytogenes isolation from carcasses sampled at the slaughterhouse B suggests that there were flaws in its slaughter process. Nevertheless, the L. monocytogenes contamination on the carcasses may not have been originated from feces, since this Listeria specie was found in only one sample of pen feces. In spite of the fact that slaughterhouse A presented a significantly lower mean of coliforms on the pre-chill carcasses, indicating that there was a better hygiene in the slaughtering process, the frequency of S. enterica on the carcasses was not different in comparison to those found in the other sampled slaughterhouses. This result may be related to the large number of fecal carriers detected at the lairage, which in turn may have led to an increase on the carcass contamination hazard throughout the slaughter line. In conclusion, S. enterica and L. monocytogenes can be isolated from pre-chill pig carcasses. Whereas the high number of Salmonella fecal carriers may have contributed to the frequency of contaminated carcasses, L. monocytogenes strains found on carcasses were probably not originated from feces.

Frequência de suínos soropositivos para Salmonella sp. em granjas afetadas em diferentes níveis de severidade pela Síndrome Multissistêmica de Definhamento do Leitão Desmamado / Frequency of Salmonella seropositive pigs in farms affected by different severity levels of the Post-weaning Multisystemic Wasting Syndrome

The Post-weaning Multisystemic Wasting Syndrome (PMWS) has caused considerable losses due to mortality and wasting of pigs and has been often associated with co-infections with other viral or bacterial agents. At the present time, PMWS is the most important infectious disease syndrome in the Brazilian swine production. With a variety of symptoms, this syndrome affects the immune system and can thus open the door for co-infections, which results in performance losses. Positive results of immunohistochemistry for PCV2 in pigs, we obtained the isolation of Salmonella enterica in 36.2% cases, demonstrate that co-infection occurs in Brazilian herds. However, there is still determining whether there is an increase in the number of carriers of Salmonella sp. in swine herds affected by PCV2. From this, the present study aimed to investigate the frequency of animals positive for Salmonella sp. in pig herds with different levels of intensity of involvement by PMWS.

Frequência de suínos soropositivos para Salmonella sp. em granjas afetadas em diferentes níveis de severidade pela Síndrome Multissistêmica de Definhamento do Leitão Desmamado / Frequency of Salmonella seropositive pigs in farms affected by different severity levels of the Post-weaning Multisystemic Wasting Syndrome

The Post-weaning Multisystemic Wasting Syndrome (PMWS) has caused considerable losses due to mortality and wasting of pigs and has been often associated with co-infections with other viral or bacterial agents. At the present time, PMWS is the most important infectious disease syndrome in the Brazilian swine production. With a variety of symptoms, this syndrome affects the immune system and can thus open the door for co-infections, which results in performance losses. Positive results of immunohistochemistry for PCV2 in pigs, we obtained the isolation of Salmonella enterica in 36.2% cases, demonstrate that co-infection occurs in Brazilian herds. However, there is still determining whether there is an increase in the number of carriers of Salmonella sp. in swine herds affected by PCV2. From this, the present study aimed to investigate the frequency of animals positive for Salmonella sp. in pig herds with different levels of intensity of involvement by PMWS.(AU)

Tempo de jejum dos suínos no manejo pré-abate sobre a perda de peso corporal, o peso do conteúdo estomacal e a incidência de úlcera esofágica-gástrica / Relation of fasting time during pre-slaughter management to weight loss, weight of stomach contents and incidence of gastric ulcer in pigs

O objetivo deste trabalho foi avaliar os efeitos do tempo de jejum (9, 12, 15 e 18 horas) dos animais na granja (TJG) e da posição na carroceria do caminhão (PBO) durante o transporte da granja ao frigorífico sobre: a perda de peso corporal (PPC), o peso do estômago cheio (PEC) e vazio (PEV), o peso do conteúdo estomacal (PCE) e o escore de lesão na mucosa esofágica-gástrica (ELG). Foram utilizadas 192 fêmeas, com peso vivo médio de 134,51±11,80kg. No modelo, foram considerados os efeitos de bloco (estação do ano, BL), TJG, PBO e da interação entre BL x TJG. Verificou-se efeito significativo do TJG apenas sobre o peso do conteúdo estomacal. Não se observou efeito significativo da PBO sobre qualquer das variáveis avaliadas. Dos suínos avaliados, 90,3 por cento apresentaram PEC menor que 500 gramas e 8,56 por cento com PEC entre 500 e 800 gramas. A prevalência de suíno com ELG foi baixa (14,97 por cento), sendo que, dos animais com ELG, 13,90 por cento apresentaram lesão de grau 1 e 1,09 por cento eram grau dois. Conclui-se que animais submetidos a jejum na granja de 15 horas apresentam menor peso do conteúdo estomacal ao abate.(AU)

The objective of this study was to evaluate the effect of fasting time period (9, 12, 15 and 18 hours) at the farm (TJG) and the pig's position in the lorry's livestock compartment (PBO) during the transport from the farm to the processing plant on: body weight loss (PPC), weight of stomach (full= PEC and empty= PEV), weight of stomach contents (PCE), and incidence of gastric ulcer (ELG). A total of 192 females with average 34.51±11.80kg of body weigh were used. The statistical model considered the effects of: block (season, BL), TJG, PBO and the interaction between BL and TJG. There was a significant effect of TJG only on stomach content. There was no effect of PBO on any of the evaluated variables. A PEC inferior to 500g was observed in 90.3 percent of the animals, while 8.56 percent of the pigs presented PEC between 500 and 800g. Incidence of ELG was low (14.97 percent), and among the ELG animals, 13.90 percent showed grade 1 lesion, and 1.09 percent grade two lesion. As a conclusion, pigs submitted to a fasting period of 15 hours have less stomach contents at the processing.(AU)