RESUMO A paratuberculose em bovinos de corte já foi diagnosticada no estado do Rio Grande do Sul, mas relatada em apenas um rebanho. Nesse contexto, o objetivo desta pesquisa é verificar se a paratuberculose pode ser detectada em rebanhos de bovinos de corte de diferentes mesorregiões do RS, por meio do teste ELISA. As amostras foram coletadas de bovinos provenientes de seis mesorregiões, entre elas as maiores produtoras de bovinos de corte do RS. Apenas duas amostras foram classificadas como suspeitas no teste de ELISA, as outras 391 amostras foram negativas. Os resultados demonstram baixa detecção da doença nas mesorregiões testadas, com apenas 0,5% das amostras com resultado suspeito. Assim, esses dados demonstram que a enfermidade é pouco frequente nos rebanhos testados e que um programa de controle pode ser implementado de forma viável e economicamente lucrativa.

ABSTRACT Lead is a heavy metal and an important cause of acute or chronic toxicosis in humans, domestic, and wild animals. This report aims to describe a case of chronic lead poisoning in a jaguar (Panthera onca) kept under human care that was rescued from the wild environment. The animal was rescued in poor condition in 2004 and kept under human care at the Belo Horizonte Zoological Garden (Minas Gerais, Brazil) until 2020, when it presented with anorexia, vomiting and ataxia. Over the past years the animal had episodes of anemia and increased serum urea and creatinine. Radiography demonstrated 21 radiopaque projectiles on the right side of the face. At necropsy there were multiple projectiles surrounded by fibrous tissue in the subcutaneous of the right side of the face, fibrinous peritonitis, multiple gastric ulcers, and melena. The lead dosage was performed using the atomic absorption spectrometry technique using renal tissue collected at necropsy, with a result of 908 ppb (µg/kg). The findings of projectiles associated with the dosage of lead above the reference limits allow the diagnosis of chronic intoxication in this case.

RESUMO Chumbo é um metal pesado e uma causa importante de toxicose crônica no homem e em animais domésticos e selvagens. Este relato teve como objetivo descrever um caso de intoxicação crônica por chumbo em uma onça-pintada (Panthera onca), mantida sob cuidados humanos, que foi resgatada de seu ambiente natural em 2004, em pobre condição corporal. O animal foi encaminhado ao zoológico de Belo Horizonte (MG, Brasil), onde permaneceu até 2020, quando desenvolveu anorexia, vômitos e ataxia. Durante os últimos anos, o animal teve episódios de anemia e aumento da concentração sérica de ureia e creatinina. O exame radiográfico demonstrou 21 projéteis radiodensos na face direita. À necropsia, foram observados vários projéteis envoltos por tecido conjuntivo no subcutâneo da face esquerda, peritonite fibrinosa, múltiplas úlceras gástricas e melena. A concentração de chumbo foi determinada por espectrometria de absorção atômica em amostras de tecido renal, indicando 908 ppb (µg/kg). O achado de projéteis de chumbo associado à elevada concentração de chumbo é compatível com intoxicação crônica por chumbo neste caso.

ABSTRACT Degradation of bovine small intestine and respective effects on biomechanics have not been described to date. Biomechanical testing of intestinal tissues is often carried out within a few hours of donor death and tissue deterioration is not accounted for. Freezing is efficient for the preservation of several tissues; however, it may cause cellular damage. This study investigated the morphologic and biomechanical changes of bovine jejunum at different postmortem moments. Effects of freezing and thawing on morphology and biomechanical behavior were also examined. Macroscopic changes were first noted within eight hours of death. At this time, histologic changes also started to set in, and biomechanical tests revealed lower bursting pressure (203.10±46.14mmHg). At 12 hours, tissue rearrangement was noted, and bursting pressure increased (238.43±31.04mmHg). A second drop in pressure was detected at 18 hours (235.20±38.21mmHg), followed by a progressive drop until the end of the experimental period. Histologic changes revealed progressive deterioration. Mechanical resistance did not differ between thawed and fresh specimens. It was concluded that bovine jejunal specimens retain biomechanical resistance up to 6 hours after death. Freezing and thawing did not affect the mechanical resistance of the intestinal wall in this experimental model.

RESUMO A degradação do intestino delgado de bovinos e seu efeito biomecânico não são descritos na literatura. Trabalhos que envolvem a biomecânica intestinal realizam os ensaios em poucas horas após o óbito dos doadores, sem avaliação de seu estado de deterioração. O congelamento é eficiente na conservação de vários tecidos, porém pode provocar danos em nível celular. Este estudo teve por objetivo avaliar a degradação morfológica e biomecânica do jejuno de bovinos em diferentes tempos post mortem. O efeito do congelamento e do descongelamento sobre essas características também foi avaliado. As primeiras alterações macroscópicas foram observadas oito horas após o óbito. No mesmo momento, se iniciaram as alterações histológicas e a menor pressão suportada ao teste biomecânico (203,10±46,14mmHg). A partir de 12 horas, o tecido sofreu um rearranjo, suportando maior pressão (238,43±31,04mmHg). Uma segunda queda foi detectada após 18 horas (235,20±38,21mmHg), seguida de redução progressiva até o término do experimento. As lesões histológicas foram progressivas e graduais. As amostras testadas após descongelamento não apresentaram diferença estatística quanto à resistência mecânica em comparação com os espécimes frescos. Concluiu-se que as amostras mantêm sua resistência biomecânica até 6 horas após o óbito. Também se mostrou que o congelamento e o descongelamento, nas condições testadas, não alteraram a resistência mecânica da parede intestinal.

ABSTRACT Hypospadias is an uncommon sexual development disorder in cats, in which the urethral opening is not in its anatomical location on the penis. The purpose of this report is to describe two cases of hypospadias in the feline species. The first cat was asymptomatic, had a history of bacterial cystitis, and was diagnosed with perineal hypospadias at an appointment for preoperative evaluation of orchiectomy. The second cat had clinical signs of dysuria and pollakiuria for 30 days and had glandular hypospadias. Both cats showed abnormalities in the urinalysis which were suggestive of lower urinary tract disease. For both cases, clinical treatment with antibiotic therapy was performed. In the first patient, surgical treatment consisted of orchiectomy, while in the second animal a perineal urethrostomy and orchiectomy were performed. The cats had a satisfactory recovery after the treatments. Performing a thorough physical examination is essential to diagnose cases of hypospadias and choose the best treatment for each patient.

RESUMO A hipospadia é uma desordem do desenvolvimento sexual pouco comum nos gatos, na qual a abertura uretral não está em sua localização anatômica do pênis. O objetivo do presente relato é descrever dois casos de hipospadia em felinos domésticos. O primeiro gato era assintomático, tinha histórico de cistite bacteriana prévio, e foi diagnosticado com hipospadia perineal em uma consulta para avaliação pré-cirúrgica de orquiectomia. O segundo gato apresentava sinais clínicos de disúria e polaquiúria há 30 dias e apresentava hipospadia glandular. A partir dos exames complementares, pôde-se observar que os animais, além do defeito anatômico, apresentavam alterações sugestivas de doença do trato urinário inferior. Para ambos os casos, foi realizado o tratamento clínico inicial com antibioticoterapia. No primeiro paciente, optou-se pelo procedimento de orquiectomia, enquanto no segundo animal foram realizadas as técnicas de uretrostomia perineal e orquiectomia. Os gatos mostraram recuperação satisfatória após os tratamentos instituídos. Dessa forma, pode-se observar a importância de se realizar um exame físico minucioso a fim de diagnosticar os casos de hipospadia e escolher o tratamento correto para cada paciente.

ABSTRACT Fusarium head blight, also known as fusariosis, is caused by a fungus called Fusarium graminearum that produces the mycotoxin deoxynivalenol (DON). This toxin causes problems to human and animal health. Ammonia gas has been shown to be effective in deactivating mycotoxins. The objectives of this study were to evaluate the effectiveness of ammonia gas in the deactivation of DON in wheat grains, the effect of this treatment on its protein composition and the toxicity in rats fed with ammoniated wheat grains. Wheat samples were exposed to ammonia gas at concentrations of 0% (Control), 0.5%, 1% and 1.5%. It was observed that ammonia gas was effective in deactivating DON at concentrations of 1% and 1.5%. There was no difference in crude protein observed in the bromatological analysis of treated wheat grains in relation to the control. Regarding the toxicity of wheat grains treated with ammonia in the feeding of Wistar rats (Rattus norvegicus), no histopathological alterations were observed in the liver, kidneys, intestine and in the hematological profile. The results of this study demonstrated that the treatment of wheat with ammonia gas can contribute to the deactivation of DON without compromising its protein composition and animal health.

RESUMO A giberela, também conhecida como fusariose, é causada por um fungo chamado Fusarium graminearum, que produz a micotoxina desoxinivalenol (DON). Essa toxina gera problemas à saúde humana e animal. O gás amônia demonstrou ser eficaz na desativação das micotoxinas. Os objetivos deste estudo foram avaliar a eficácia do gás amônia na desativação do DON em grãos de trigo contaminados naturalmente, o efeito desse tratamento na sua composição proteica e a toxicidade em ratos alimentados com os grãos de trigo amonizados. Amostras de trigo foram expostas ao gás amônia nas concentrações de 0% (controle), 0,5%, 1% e 1,5%. Observou-se que o gás amônia foi eficaz na desativação do DON na concentração de 1% e 1,5%. Não houve diferença na proteína bruta observada na análise bromatológica dos grãos de trigo tratados em relação ao controle. Quanto à toxicidade dos grãos de trigo tratados com amônia fornecidos aos ratos Wistar (Rattus norvegicus), não foram observadas alterações histopatológicas do fígado, dos rins e do intestino e no perfil hematológico. Os resultados deste estudo demonstraram que o tratamento de trigo com gás amônia pode contribuir na desativação do DON sem comprometer sua composição proteíca e a saúde dos animais.

RESUMO Infecções causadas por Aeromonas trazem grandes prejuízos à piscicultura. Entre os fatores associados à patogênese bacteriana, a captação de ferro pode contribuir para a sobrevivência e a virulência das bactérias dentro dos hospedeiros. O objetivo deste estudo foi verificar a presença de genes relacionados à captação de ferro em Aeromonas hydrophila provenientes de organismos aquáticos do Vale do São Francisco e associar a presença desses genes com a capacidade de as bactérias crescerem em meios contendo diferentes concentrações de ferro. Os DNAs de 41 isolados foram extraídos e utilizados em PCRs para verificar a presença dos genes Fur, AmoA e pvcAB relacionados à captação de ferro. O crescimento dos isolados pertencentes a diferentes perfis genéticos foi verificado em meios de cultura contendo diferentes concentrações de ferro. Dois isolados foram positivos para a presença do gene Fur, sete para a do gene AmoA e dois para a do gene pvcAB. O teste de crescimento mostrou que a baixa disponibilidade de ferro não interferiu no crescimento dos isolados nem no isolado que não continha nenhum dos genes avaliados neste estudo, sugerindo que os mecanismos de captação de ferro dos isolados testados podem estar relacionados a outros genes e proteínas.

ABSTRACT Infection caused by Aeromonas brings great harm to fish farming. Among the factors associated with bacterial pathogenesis, iron uptake can contribute to the survival and virulence of bacteria within hosts. The aim of this study was to check the presence of genes related to iron uptake in Aeromonas hydrophila deriving from aquatic organisms in the São Francisco Valley and associate the presence of these genes with the ability to grow in media containing different concentrations of iron. The DNAs of 41 isolates were extracted and used in PCRs to verify the presence of the Fur, AmoA and pvcAB genes related to iron uptake. The growth of the isolates belonging to different genetic profiles was verified in culture media containing different iron concentrations. Two isolates were positive for the presence of the Fur gene, seven for the AmoA gene and two for the pvcAB gene. The growth test showed that the low availability of iron did not interfere in the growth of the isolates, nor in the isolate that did not contain any of the genes evaluated in this study, suggesting that the iron uptake’s mechanisms of the tested isolates may be related to other genes and proteins.

RESUMO A mastite representa uma das principais enfermidades nos rebanhos de caprinos leiteiros, com implicações na produção de leite e na qualidade final dos derivados. Objetivou-se observar a influência do tratamento da mastite com o extrato etanólico da Hymenaea martiana Hayne sobre as características físico-químicas e sensoriais do queijo tipo coalho. Uma pomada contendo extrato foi elaborada para uso intramamário em seis fêmeas caprinas especializadas na produção de leite. As metades esquerdas dos tetos das cabras receberam essa infusão, enquanto a metade direita era controle. O experimento foi conduzido em três momentos experimentais. Realizou-se ordenha manual e análise físico-química do leite. Para o queijo, foram realizados testes físico-químicos e teste sensorial. Quantos aos aspectos físico-químicos do leite, é possível afirmar que não houve diferença (P>0,05) entre os grupos. Houve diferença estatística para sólidos não gordurosos nos momentos experimentais M1 e M2. As médias de proteína variaram entre 3,33 e 3,62, e houve diferença estatística em dois momentos. As médias de lactose variaram entre 4,79% e 5,38%. Os aspectos físico-químicos do queijo mantiveram resultados similares entre os dois tratamentos. Os parâmetros sensoriais para o queijo coalho de cabra não tiveram diferença estatística entre os tratamentos, contudo a aparência se destacou em relação aos demais parâmetros sensoriais. O uso da pomada elaborada com extrato de jatobá não interferiu sobre as características físico-químicas do leite de cabra e sobre as características físico-químicas e sensoriais do queijo tipo coalho de cabra.

ABSTRACT Several studies have assessed the therapeutic potential of natural products against mastitis, but only a few have evaluated the impacts of this alternative therapy on the main properties of milk and dairy products. In this study, we observed how the treatment of mastitis with ethanolic extract of Jatobá (Hymenaea martiana Hayne) influenced the physicochemical and sensory characteristics of coalho cheese. An ointment containing the ethanolic extract was prepared for intramammary use in six dairy goats. The experiment was conducted in three experimental moments. Milking was performed, manually, and both milk and cheese were subjected to physicochemical and sensory tests. No difference was observed (p>0.05) in the physicochemical aspects of milk between the studied groups. The solids-non-fat showed a statistical difference between experimental moments M1 and M2. The protein means varied from 3.33 to 3.62, and there was a statistical difference between the two moments, while the lactose means varied from 4.79 to 5.38%. The physicochemical aspects of cheese remained similar with both treatments. Except for appearance, the sensory characteristics showed no statistical difference. In conclusion, the use of Jatobá extract ointment did not influence the physicochemical and sensory characteristics of goat milk or cheese.

The aim of this study was to evaluate the ability of the antioxidant myricetin to protect ovine spermatozoa during freezing-thawing. Five semen pools, obtained from four rams, were diluted and frozen in Tris-egg yolk extender (5% glycerol) supplemented with myricetin at 0, 20, 30, 40, 100, 200, 300, and 400 nM. After thawing at 37 °C for 30 seconds and incubation (37 °C) for two hours, these variables were measured: kinematics, plasma and acrosome membrane integrity, mitochondrial membrane potential, intracellular reactive oxygen species (ROS) levels, lipid peroxidation and membrane stability. There was no interaction between treatment and time, and no direct effect of treatments for the kinematics parameters (P >0.09; P >0.2113, respectively) and flow cytometry (P >0.41; P > 0.52, respectively). The means of progressive motility, curvilinear velocity, straight-line velocity, average path velocity, linearity, amplitude of lateral head displacement, percentage of intact plasma membrane and acrosome membrane, oxidative stress and membrane stability were reduced during incubation (P <0.04), whereas the cross-beat frequency increased (P =0.0001) throughout incubation. Thus, the addition of myricetin to the semen extender does not produce an antioxidant effect on ram semen in vitro.

Abstract A thermal comfort index for the Northeast of Brazil was analyzed for two scenarios of climatic changes, A1B and A2, for 2021-2080, and compared with the reference period 1961-1990. A technique of regionalization was applied to rainfall, maximum and minimum temperature data from meteorological stations, obtained by statistical downscaling of projections from four global climate models. The results pointed to a significant reduction of rainfall and an increase of temperature for three different climatically homogeneous subregions. Regarding the thermal comfort index, the results point to an increase in days with heat discomfort between 2021 and 2080. In the northern portion, the higher percentage of days with heat discomfort will be significant since the first half of the period under appreciation, i.e., from 2021 to 2050. Conversely, in the eastern of northeastern Brazil, the increase of days with heat discomfort should happen in the period from 2051 to 2080, whereas the central-western part of the region, which, in the reference period, had recorded less than 1% of days with heat discomfort, might see an elevation of that percentage to 7% between 2021 and 2050, potentially reaching 48% of its days made uncomfortable by heat between 2051 and 2080.

RESUMO A relação da eficiência nutricional com a idade e o peso à puberdade e as características reprodutivas foram estudadas em 35 novilhas F1 Holandês x Gir, em ensaios usando o consumo alimentar residual (CAR) nos períodos pós-desaleitamento (PD) e pós-puberdade (PP). Novilhas PD (P<0,0001) e PP (P<0,001) foram ranqueadas como de alta, intermediária e baixa eficiências e apresentaram CAR de -0,259 -0,014 e 0,346kg/dia e -0,848 -0,096 e 0,842kg/dia, respectivamente. Novilhas PD diferiram (P<0,05) na idade à puberdade entre ranques de alta, intermediária e baixa eficiências, em média, aos 339,7; 346,4; 315,3 dias, respectivamente. Os pesos à puberdade de novilhas PD com alta, intermediária e baixa eficiências foram, em média, de 321±28,1kg e não diferiram (P>0,05) entre CAR. Não foi verificada correlação entre diâmetro folicular, taxa de crescimento do folículo, número de ondas foliculares no ciclo estral e taxa de gestação à primeira IA com o CARPD ou CARPP. Novilhas F1HG selecionadas para CAR com baixa eficiência podem ter idade à puberdade 10 dias a mais, quando comparadas às novilhas de alta eficiência para CAR. Não foi verificado que novilhas selecionadas para alta ou baixa eficiências alimentares, usando CAR, tivessem algum impacto negativo sobre características reprodutivas avaliadas.

ABSTRACT The relationship between nutritional efficiency and age and weight at puberty and reproductive traits was studied in 35 F1 Holstein x Gyr heifers, in trials using residual food consumption (CAR) in the post-weaning (PW) and post-pubertal (PP) periods. PD heifers (P<0.0001) and PP (P<0.001) were classified as high, intermediate and low efficiencies and presented CAR of -0.259 -0.014 and 0.346kg/day and -0.848 -0.096 and 0.842kg/day, respectively. PD heifers differed (P<0.05) in age at puberty between high, intermediate and low efficiencies, on average, at 339.7, 346.4 and 315.3 days, respectively. The weight at puberty of PD heifers with high, intermediate and low efficiencies were, on average, 321±28.1kg and did not differ (P>0.05) between CAR. No correlation was found between follicular diameter, follicle growth rate, number of follicular waves in the estrous cycle and pregnancy rate at 1st AI with the CARPD or CARPP. F1HG heifers selected for CAR with low efficiency can be aged at puberty 10 days longer when compared to high-efficiency heifers for CAR. These results did not show that heifers selected for high or low food efficiency, using CAR, had negative impact on the reproductive characteristics evaluated.

ABSTRACT The aim of the present study was to evaluate the antibacterial behavior of polypyrrole nanoparticles (PPy-NPs) in water against biofilm producer or not S. aureus isolated from cows and goats with mastitis. One hundred and thirty-eight isolates of S. aureus were initially evaluated for biofilm formation by spectrophotometry in microplates. In addition, the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs in water for planktonic S. aureus were determined. From the bovine samples analyzed, 5 (4.46%) S. aureus isolates showed a strong biofilm production, 17 (15.18%) moderate production, 36 (32.14%) with weak production and 54 (48.21%) did not produce biofilms. Strains from goats (26) showed no biofilm production in 18 (69.23%) strains and weak biofilm production in 8 (30.76%) strains. The MIC and MBC of S. aureus to PPy-NPs were found in the same concentration (125µɡ/mL) in all strains tested, regardless of biofilm production or not. This finding provides a new insight into the interaction between PPy-NPs and S. aureus, and will offer potential benefits for the control of mastitis.

Abstract The Southwestern Region of the Brazilian Amazon is formed by forests dominated by bamboos. The genus Guadua is endemic to the Americas, and little is known about the genetic diversity and structure of species of this genus. This study aimed to evaluate the genetic diversity and structure of two native Guadua species in natural populations in the Southwestern region of the Brazilian Amazon. Therefore, the genetic diversity and structure of Guadua aff. chaparensis and Guadua aff. lynnclarkiae were evaluated with the use of microsatellite molecular markers (SSR). It was verified that the average genetic diversity for the populations studied was considered high ( H ^ e =0.5) compared to other species of bamboo. All populations had rare and private alleles, and none of them presented significant values of inbreeding. The populations were divergent ( G ^ ST = 0.46), resulting in a low apparent gene flow. The Bayesian analysis showed that among the 350 individuals analyzed, five groups (K=5) were formed, with little similarity among the groups (Populations), although two of them presented clonal individuals. According to the results obtained, it can be conclude that populations should be treated as having unique characteristics, mainly when accessed for management and for in situ and ex situ conservation studies.

Abstract Solidago microglossa is used as an anti-inflammatory agent in traditional Brazilian medicine, and this work evaluated the anti-inflammatory potential of the crude ethanolic extract of the flowers of S. microglossa in vivo, as assayed by paw edema models induced by carrageenan, prostaglandin E2, bradykinin and compound 48/80. In the chemical profile, we identified compounds by electrospray ionization mass spectrometry and quantified them by HPLC-DAD. Additionally, this study analyzed the potential to activate the in vitro transcriptional activity of PPARγ, which is a nuclear receptor linked to the anti-inflammatory response. It was possible to identify five compounds: quinic acid, quercetin, chlorogenic acid, hyperoside, and rutin. In the paw edema evaluation, it was possible to show the potential of reducing edema during the inflammatory process. The crude ethanolic extract of the flowers of S. microglossa activated PPARγ compared to the full agonist rosiglitazone and in a dose-response manner. It is possible to conclude that the extract of the flowers of S. microglossa showed anti-inflammatory activity, and the phenolic compounds present in this species might be responsible for this activity.

ABSTRACT The morphology of the ruminal and omasal mucosa and hepatic parenchyma of 44 young bulls submitted to four types of concentrates were evaluated by varying the inclusion level of crude Glycerin - CG (0, 6, 12 and 18%). The variables evaluated were number of ruminal papillae per cm² of wall; area of the papillae and total absorption surface per cm² of wall; Mitotic index - MI, height and area of ruminal and omasal papillae; and hepatic morphology. The samples processed for inclusion in paraffin and stained with Hematoxylin-Eosin. The different levels of inclusion of CG in the diet did not interfere either in the number of papillae per cm2 of rumen wall (P= 0,70) or in the ruminal absorptive surface area (P= 0,89). Animals that received diets with levels 12 and 18% had higher MI of the ruminal epithelium (P< 0.01), but higher cell proliferation wasn’t reflected in height gain and papillary area (P= 0,82). The omasal mucosa wasn’t influenced by the inclusion of CG (MI e height gain and papillary area, P= 0,43, P= 0,56 e P= 0,9, respectively). The inclusion of GB in up to 18% of diet dry matter didn’t alter the morphology of the rumen and omaso mucosa; and the integrity hepatic parenchyma.

RESUMO Doenças entéricas de origem bacteriana são frequentes na indústria de suínos, destacando-se a colibacilose, que afeta principalmente leitões e causa grandes danos à indústria suína em todo o mundo. Cento e vinte e seis cepas de Escherichia coli foram isoladas de swabs obtidos de fragmentos de intestino delgado de 235 suínos saudáveis abatidos em matadouros de Pernambuco (Brasil). O objetivo do presente estudo foi analisar filogeneticamente essas cepas, bem como detectar a produção de biofilme e determinar o perfil de resistência antimicrobiana delas, utilizando-se a reação em cadeia da polimerase (PCR), o teste de adesão em microplacas e a técnica de disco-difusão. 88,10% (111/126) das amostras foram classificadas no grupo filogenético B1; 4,76% (6/126) no grupo D; 3,97% (5/126) no grupo B2; e 3,17% (4/126) no grupo A. As taxas de resistência antimicrobiana observadas foram: lincomicina 100% (126/126), eritromicina 100% (126/126), clortetraciclina 94,44% (119/126), cefalotina 51,59% (65/126), ampicilina 38,89% (49/126), sulfametoxazol + trimetoprima 37,3% (47/126), ciprofloxacina 19,84% (25/126), norfloxacina 14,29% (18/126), gentamicina 8,73% (11/126) e cloranfenicol 5,55% (7/126). O índice de resistência múltipla (IRMA) variou de 0,2 a 0,9. Entre as amostras, 46,03% (58/126) produziram biofilme e 99,21% (125/126) foram multirresistentes. São necessários mais estudos para elucidar a importância de cada grupo filogenético em suínos e evitar a propagação de estirpes de E. coli multirresistentes.

ABSTRACT Enteric diseases of bacterial origin are frequent in the pig industry, of particular notoriety are the colibacillosis that mainly affect piglets and cause great damage to the swine industry worldwide. The aim of the study was to analyze phylogenetics, to detect biofilm production, and to determine antimicrobial resistance profile in 126 strains of Escherichia coli isolated from swabs obtained from fragments of the small intestines of 235 healthy pigs killed in slaughterhouses in Pernambuco (Brazil) using polymerase chain reaction (PCR), adherence to microplates test and disc diffusion technique. Of the analyzed samples, 88.10% (111/126) were classified in phylogenetic group B1; 4.76% (6/126) in group D; 3.97% (5/126) in group B2 and, 3.17% (4/126) in group A. Antimicrobial resistance rates observed were: lincomycin 100% (126/126), erythromycin 100% (126/126), chlortetracycline 94.44% (119/126), cephalothin 51.59% (65/126), ampicillin 38.89% (49/126), sulfamethoxazole + trimethoprim 37.3% (47/126), ciprofloxacin 19.84% (25/126), norfloxacin 14.29% (18/126), gentamicin 8.73% (11/126) and, chloramphenicol 5.55% (7/126). Multiple antibiotic resistance (MAR) ranged from 0.2 to 0.9. Of the strains tested 46.03% (58/126) produced biofilm, and 99.21% (125/126) of the strains exhibited multi-resistance. Further studies are required to elucidate the importance of each phylogenetic group in pigs and to prevent the propagation of multi-resistant E. coli strains.