Molecular characterization and biofilm-formation analysis of Listeria monocytogenes, Salmonella spp., and Escherichia coli isolated from Brazilian swine slaughterhouses.

This study aimed to verify the presence of Listeria monocytogenes, Salmonella spp., and Escherichia coli in two Brazilian swine slaughterhouses, as well as to perform antibiograms, detect virulence and antimicrobial resistance genes, and evaluate the in vitro biofilm-forming capability of bacterial isolates from these environments. One Salmonella Typhi isolate and 21 E. coli isolates were detected, while L. monocytogenes was not detected. S. Typhi was isolated from the carcass cooling chamber's floor, resistant to several antimicrobials, including nalidixic acid, cefazolin, chloramphenicol, doxycycline, streptomycin, gentamicin, tetracycline, and sulfonamide, and contained resistance genes, such as tet(B), tet(C), tet(M), and ampC. It also showed moderate biofilm-forming capacity at 37°C after incubating for 72 h. The prevalence of the 21 E. coli isolates was also the highest on the carcass cooling chamber floor (three of the four samplings [75%]). The E. coli isolates were resistant to 12 of the 13 tested antimicrobials, and none showed sensitivity to chloramphenicol, an antimicrobial prohibited in animal feed since 2003 in Brazil. The resistance genes MCR-1, MCR-3, sul1, ampC, clmA, cat1, tet(A), tet(B), and blaSHV, as well as the virulence genes stx-1, hlyA, eae, tir α, tir ß, tir γ, and saa were detected in the E. coli isolates. Moreover, 5 (23.8%) and 15 (71.4%) E. coli isolates presented strong and moderate biofilm-forming capacity, respectively. In general, the biofilm-forming capacity increased after incubating for 72 h at 10°C. The biofilm-forming capacity was the lowest after incubating for 24 h at 37°C. Due to the presence of resistance and virulence genes, multi-antimicrobial resistance, and biofilm-forming capacity, the results of this study suggest a risk to the public health as these pathogens are associated with foodborne diseases, which emphasizes the hazard of resistance gene propagation in the environment.

Molecular characterization of Salmonella spp. and Listeria monocytogenes strains from biofilms in cattle and poultry slaughterhouses located in the federal District and State of Goiás, Brazil.

Listeria monocytogenes and Salmonella spp. are considered important foodborne pathogens that are commonly associated with foods of animal origin. The aim of this study was to perform molecular characterization of L. monocytogenes and Salmonella spp. isolated from biofilms of cattle and poultry slaughterhouses located in the Federal District and State of Goiás, Brazil. Fourteen L. monocytogenes isolates and one Salmonella sp. were detected in poultry slaughterhouses. No isolates were detected in cattle slaughterhouses. All L. monocytogenes isolates belonged to lineage II, and 11 different pulsotypes were detected. Pulsed-field gel electrophoresis analysis revealed the dissemination of two strains within one plant, in addition to the regional dissemination of one of them. The Salmonella isolate was identified via whole genome sequencing as Salmonella enterica serovar Minnesota ST548. In the sequence analysis, no premature stop codons were detected in the inlA gene of Listeria. All isolates demonstrated the ability to adhere to Caco-2 cells, while 50% were capable of invading them. Antimicrobial resistance was detected in 57.1% of the L. monocytogenes isolates, and resistance to sulfonamide was the most common feature. The tetC, ermB, and tetM genes were detected, and four isolates were classified as multidrug-resistant. Salmonella sp. was resistant to nine antimicrobials and was classified as multidrug-resistant. Resistance genes qnrB19, blaCMY-2, aac(6')-Iaa, sul2, and tetA, and a mutation in the parC gene were detected. The majority (78.5%) of the L. monocytogenes isolates were capable of forming biofilms after incubation at 37°C for 24 h, and 64.3% were capable of forming biofilms after incubation at 12°C for 168 h. There was no statistical difference in the biofilm-forming capacity under the different evaluated conditions. Salmonella sp. was capable of forming biofilms at both tested temperatures. Biofilm characterization was confirmed by collecting the samples consistently, at the same sampling points, and by assessing biofilm formation in vitro. These results highlight the potential risk of cross-contamination in poultry slaughterhouses and the importance of surveillance and pathogen control maintenance programs within the meat production industry.

Pesquisa de Clostridium perfringens em carnes bovinas embaladas a vácuo comercializadas no Distrito Federal e entorno / Clostridium perfringens research on vacuum packed beef commercialized on Distrito Federal and in the surrounding area

O objetivo deste trabalho foi detectar a presença de Clostridium perfringens em 54 amostras de carne bovina embaladas a vácuo comercializadas na região do Distrito Federal, bem como detectar a presença da toxina cpe por PCR, ainda avaliar os meios de cultivo ágar SPS® e ágar TSC®, com e sem etapa de pré-enriquecimento das amostras em caldo infusão de cérebro e coração (BHI) na câmara de anaerobiose, e posterior incubação das placas de SPS® e TSC® tanto em jarra de anaerobiose, como em câmara de anaerobiose. Na análise da incubação das placas em ágar SPS® e TSC®, sem a etapa de pré-enriquecimento em caldo BHI na câmara de anaerobiose, observou-se o crescimento em apenas uma (1,85%) das 54 amostras analisadas, em ambos os meios de cultivo e formas de incubação. Com a etapa de pré-enriquecimento com caldo BHI em câmara de anaerobiose, observou-se crescimento em todas as 54 amostras (100%), em ambos os meios de cultivo e formas de incubação. Na reação em cadeia de polimerase (PCR) nenhuma das cepas oriundas das amostras analisadas apresentaram a amplificação de fragmento do gene da toxina cpe. Os resultados evidenciam a presença de C. perfringens em carnes embaladas a vácuo comercializadas no Distrito Federal e Entorno, porém não foi detectada a toxina cpe em nenhuma cepa isolada analisada. Na comparação estatística aplicando o teste qui-quadrado de McNemar, observou-se que houve diferença significativa (p<0,001) entre as análises sem e com a etapa de pré-enriquecimento em caldo BHI, verificando-se a influencia positiva do meio na recuperação de esporos, destacando desta forma a importância do enriquecimento prévio em meio BHI e a incubação em câmara de anaerobiose, na recuperação de esporos deste microrganismo.

The aim of this work was to detect Clostridium perfringens in 54 samples of vacuum packed beef sold at the Federal District area, and to detect the presence of the cpe toxin gene by Polymerase chain reaction (PCR), also evaluate the culture medium SPS® agar and TSC® agar, with and without pre-enrichment step of the samples in Brain Heart Infusion (BHI) broth in the anaerobic chamber, and to promote the incubation of the plates in anaerobic jar and anaerobic chamber. The results of the incubation on SPS® agar and TSC® agar, without the pre-enrichment step in BHI, growth was observed in only one (1,85%) of the 54 analyzed samples, in both culture media and incubation methods. With the pre-enrichment step with BHI broth in the anaerobic chamber, growth was observed in all 54 samples (100%), in both culture media and incubation methods. At the PCR, In the polymerase chain reaction (PCR), none of the strains from the analyzed samples showed fragment amplification of the toxin cpe gene. The results showed the presence of C. perfringens in vacuum packed beef samples commercialized at the Distrito Federal area and surroundings, however the cpe toxin was not detected in any isolated strain analyzed. In the statistical test using the McNemar chi-square test, a significant difference (p<0,001) was observed between the analysis with and without pre-enrichment step in BHI broth, verifying the positive influence of the medium in spore recovery, therefore to enhance the importance of the pre-enrichment stage in BHI broth and the incubation in anaerobic chamber in spore recovery for this microorganism.

Avaliação da qualidade higienicossanitária de carcaças de bovinos oriundos de abatedouros frigoríficos do Distrito Federal e entorno / Evaluation of the hygiene and sanitary quality of carcasses of cattle from slaughterhouses of the Federal District and reversal

O trabalho realizado teve como objetivo avaliar a qualidade higienicossanitária de carcaças bovinas, oriundas de abatedouros-frigoríficos sob Inspeção Distrital (Dipova) e Federal (SIF), localizados na região do Distrito Federal e Entorno. Foram realizadas análises microbiológicas para Contagem de micro-organismos Mesófilos aeróbios estritos e facultativos, identificação do Número mais Provável de Coliformes a 45°C e Contagem de Staphylococcus aureus em 05 (cinco) diferentes pontos de 07 (sete) meias carcaças, nas quais as coletas foram realizadas antes e depois da lavagem com água clorada, perfazendo assim um total de 70 análises. Os valores médios dos resultados observados, antes da lavagem com água clorada, para Contagem de micro-organismos Mesófilos aeróbios estritos e facultativos, foram de 9,7 UFC/cm²; para Número Mais provável de Coliformes a 45ºC, de 29 germes/cm² e para Staphylococcus coagulase positivo, de 1 UFC/cm². Os valores observados nas meias carcaças, após a lavagem com água clorada na Contagem de micro- -organismos Mesófilos aeróbios estritos e facultativos foram de 1,5 UFC/ cm²; para a análise de Número Mais Provável de Coliformes a 45ºC, foi de 8,2 germes/cm² e não houve crescimento de Staphylococcus coagulase positiva. Neste trabalho verificou-se a presença de Coliformes a 45ºC e a Contagem de micro-organismos Mesófilos aeróbios estritos e facultativos antes e após a lavagem das meias carcaças e a presença de Staphylococcus coagulase positiva apenas antes das lavagem das mesmas. A lavagem das meias carcaças com água clorada diminuiu o grau de contaminação.(AU)

Avaliação eletrocardiográfica em potros quarto de milha de diferentes idades / Electrocardiographic evaluation in quarter horse foals of different ages

Foram avaliados eletrocardiograficamente 20 potros clinicamente sadios da raça Quarto de Milha, machos e fêmeas, com idade variando de 5 a 13 meses. Os animais foram divididos em quatro grupos de acordo com a idade, sendo o grupo I (GI) composto por animais de com seis meses de idade, o grupo II (GII) por animais com sete meses, o grupo III (GIII) por animais com oito meses e o grupo IV (GIV) por animais com doze meses. O ritmo encontrado em 100% dos potros foi o sinusal. Entretanto. a frequência cardíaca, assim como a amplitude de QRS, Qt e QTc apresentaram uma tendência semelhante de variação com a idade, ou seja aumentando do grupo GI para GII e a partir daí uma redução até o GIV. Nos grupos GI, GII e GIII foi observado onda T única = 1,14 mV; onda P única= 0,38 mV; e outra T única= 0,83 mV respectivamente. Pode-se observar que os resultados demonstraram variação discreta entre os grupos avaliados.

20 clinically healthy of Quarter Horses foals, males and females, with ages between 5 and 13 months were electrocardiographically evaluated. The animals were divided in four groups according to their age: the group I (GI) comprised animals with six months, the group II (GII) was constituted of animals with seven months. Group III (GIII) and group IV (GIV) contained animals with eight months and twelve months, respectively. The rhythm found in 100% of foals was sinus. However, the heart frequency, as well as the amplitude of QRS, Qt and QTc, increased from group GI to GII. From this point, all these parameters decreased until to GIV. In the groups GI, GII and GIII were observed only one wave T = 1.14 mV, an unique wave P= 0.38 mV and another unique wave T = 0.83 mV, respectively. It was observed that the Results showed a slight variation among the groups.