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The vast capacity for maintenance and dissemination in the environment are major challenges for the control of Salmonella spp. in poultry farms. The aim of this study was to assess environmental contamination by nontyphoidal Salmonella in successive broiler flocks in nine commercial broiler farms integrated with three companies in the south of Brazil, for a twelve-month production period. Recycled broiler litter, feed and swabs from the evaporative cooling system pads were analyzed, and the total enterobacteria count in the litter samples was ascertained. Positive broiler houses were identified in two of the three broiler companies studied, in which nontyphoidal Salmonella were detected for the first time in the first or second flock, and recurred in the recycled litter of subsequent flocks. Feed and evaporative cooling pad swab samples were also positive in at least one of the assessed flocks. The majority of the isolates (87.5%) originating from different flocks, broiler houses and companies that were sampled were identified as S. Heidelberg, with the prevalence of one single genotype. The total enterobacteria levels in the litter diminished as the flocks progressed, but the presence of Salmonella spp. was constant over the course of time, indicating that the litter management procedures were not capable of interrupting the cycle of residual contamination. The predominance of S. Heidelberg highlights its emergence and dissemination in this region, as well as its resistance and maintenance in the environment, and reinforces the need to improve prevention and recycled litter management measures. Made available in DSpace on 2019-11-04T18:11:46Z (GMT). No. of bitstreams: 1 final9057.pdf: 1748574 bytes, checksum: 8d934aa119670b291408db1f1fbc6c90 (MD5) Previous issue date: 2019

Chicken is a leading source of thermotolerant Campylobacter, which triggers human foodborne enteritis. This study evaluated thermotolerant Campylobacter contamination of retail chicken in southern Brazil, using qualitative and quantitative analyses. Selective enrichment in Bolton broth for 24 and 48 h after plating onto modified charcoal–cefoperazone–deoxycholate (mCCD) agar and Preston agar was assessed. The combined results of the detection and enumeration methods revealed a frequency of 70% occurrence of thermotolerant Campylobacter in chicken samples. Campylobacter was enumerated in 60% of the samples, whereas 46% of the samples were positive in the qualitative analysis. Quantitative analysis showed average counts of 3.10 ± 0.15 log10 CFU/sample. Higher numbers of Campylobacter-positive samples were found using 24-h enrichment before plating onto Preston agar (46%) than onto mCCD agar (2%). The majority of isolated strains were identified as Campylobacter jejuni, and Campylobacter coli was also found but to a lesser extent. Subtyping revealed a clear distinction between strains isolated from different chicken sources. The enriched samples plated onto mCCD agar showed extensive spreading of nonproducing extended-spectrum β-lactamases Proteus mirabilis that hampered the identification of Campylobacter colonies. P. mirabilis strains showed resistance to cefoperazone, trimethoprim, and polymyxin B present in broth and plate media used and were inhibited by rifampicin present in Preston agar. The results underline the effect of the spread of contaminant strains on Campylobacter cultures, which might be prevented using a recently revised International Organization for Standardization method for qualitative analysis of chicken.

The objective of this work was to evaluate the reduction of Campylobacter jejuni in chicken meat at 6 and 70°C, after the inoculation of a Brazilian strain. The kinetics of C. jejuni survival showed a 0.26 log (CFU g-1) decrease for each day of exposure at 6°C, and a 1.35 log (CFU g-1) decrease for each 1 log increase at 70°C. Although reduced levels of C. jejuni were found after regular intervals at both temperatures, its incomplete inactivation underlines the need of good hygiene practices for consumers to avoid campylobacteriosis. Resumo: O objetivo deste trabalho foi determinar a redução de Campylobacter jejuni em carne de frango a 6 e 70°C, após inoculação de uma cepa brasileira. A cinética de sobrevivência de C. jejuni mostrou redução de 0,26 log (UFC g-1) a cada dia de exposição a 6°C e redução de 1,35 log (UFC g-1) para cada aumento de 1 log a 70°C. Embora níveis reduzidos de C.jejuni sejam encontrados após intervalos regulares de exposição a ambas as temperaturas, a inativação incompleta ressalta a necessidade de boas práticas de higiene para os consumidores evitarem a campilobacteriose.

A study using sentinel broiler chickens was performed to address Campylobacter persistence in litter that was reused for successive flocks. Cloacal swabs, litter, drag swabs, darkling beetles, feed, and drinking water were weekly sampled and analyzed by standard microbiological procedures. Thermotolerant Campylobacter isolated strains were confirmed by polymerase chain reaction and subtyped by pulsed-field gel electrophoresis analysis. Campylobacter was not detected in samples collected immediately after downtime between broiler flocks. However, Campylobacter-positive samples were first detected at 21 d. After Campylobacter was initially isolated from the cloacal swabs, reused litter, drag swabs, or darkling beetles, these samples remained Campylobacter positive in the following weeks until the end of the rearing period. Campylobacter-positive cloacal swabs obtained from sentinel broilers ranged from 97.3% to 100% at 42 d. All isolated strains were identified as Campylobacter jejuni. Among the subtypes identified, an indistinguishable C. jejuni strain was predominant in sentinel broilers and was also detected in the other environmental samples analyzed, suggesting a common and persistent contamination source within the flocks. Sentinel broilers may have contributed to amplify the Campylobacter level, maintaining flock and broiler house contamination until the end of the production cycle.

Campylobacter is not routinely tested in foodborne disease investigations in Brazil. Here, we studied the occurrence of Campylobacter among other food-related bacteria commonly found in foodborne disease outbreaks reported in Rio Grande do Sul State, Southern Brazil. Seventy-two food samples were analyzed by using culture-based detection methods during the 18-month investigation of 36 foodborne disease outbreaks. The sampled foods from the foodborne disease outbreaks were all negative for Campylobacter. However, at least one of other routinely investigated foodborne-related bacteria was detected in 29.17% (21/72) of the samples. Taken together, these results suggest the need to monitor Campylobacter in foodborne diseases to detect sporadic cases caused by Campylobacter that might go unnoticed in Rio Grande do Sul. Made available in DSpace on 2020-11-18T09:16:29Z (GMT). No. of bitstreams: 1 final9338.pdf: 303006 bytes, checksum: 2023a019be4954fee3b2c31a4bd13aa9 (MD5) Previous issue date: 2020

The microbiological risk of recycled litter depends on the efficacy of the management system applied to inactivate residual microorganisms and preserve the health of the successive broiler flock. This study aimed to assess the viability and infectivity of the Newcastle Disease Virus (NDV), Infectious Bursal Disease Virus (IBDV) and Salmonella Heidelberg in recycled litter exposed to different treatments. The litter was contaminated with microorganisms and submitted to the treatments (T): T1: shallow fermentation; T2: quicklime (calcium oxide); T3: shallow fermentation followed by addition of quicklime; T4: no treatment. Sentinel chicks housed on the treated litter showed that T1 and T3 inactivated residual IBDV. Analysis of the litter subjected to T1 also showed reduced levels of total enterobacteria. T2 was not able to reduce the microorganisms assessed and its association with T1 (T3) failed to enhance the effect of the treatment. NDV did not survive in the broiler litter, regardless of the treatment applied, and it was also not detected in the sentinel chicks. S. Heidelberg remained viable in the litter submitted to all studied treatments, being isolated from the sentinel chicks of all the experimental groups. The antimicrobial activity of T1 and T3 was associated to higher ammonia contents in the broiler litter. The results indicate that the shallow fermentation treatment is efficient for controlling residual IBDV and total enterobacteria in the recycled litter.

Made available in DSpace on 2020-12-12T01:14:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-01 Empresa Brasileira de Pesquisa Agropecuária Infectious bursal disease (IBD) is an immunosuppressive viral disease of chickens, associated with severe economic losses and major threats to poultry production worldwide. Disease prevention programs rely on unequivocal identification of the pathogen, as well as vaccination programs. This study developed a sensitive, one-step, real-time, quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay using a hydrolysis probe system for infectious bursal disease virus (IBDV, VP1 gene) detection and quantification, which was compared to other routinely used diagnostic methods. The assay successfully detected IBD reference viruses and field isolates. The absence of cross-reactivity was detected with negative samples or with other avian viruses in the analytical specificity test. The detection limit of this assay was 70 RNA copies. RT-qPCR was more sensitive in the detection of serially diluted IBDV isolates compared to virus isolation. For clinical samples, the sensitivity and specificity values of RT-qPCR compared to enzyme-linked immunosorbent assay (ELISA) were 97.5% and 100%, respectively, and compared to histopathology, these values were 100% and 93.94%, respectively. RT-qPCR can provide a simple and reliable assay for IBDV surveillance programs and for evaluation of control strategies. Embrapa Suínos E Aves, BR 153, Km 110 Embrapa Pecuária Sudeste, Rodovia Washington Luiz, Km 234, Fazenda Canchim Departamento de Zootecnia Universidade Estadual Paulista - UNESP Departamento de Zootecnia Universidade Estadual Paulista - UNESP Empresa Brasileira de Pesquisa Agropecuária: 0313100900

Salmonella Enteritidis remains a leading cause of human foodborne disease, mostly associated with the consumption of contaminated poultry products. To more strategically implement a phage therapy scheme for S. Enteritidis control in broilers, a cocktail containing three wild-type lytic bacteriophages (LBs) previously isolated from chickens was evaluated shortly and later after a challenge. Genomic characterization, lytic spectrum and in vitro efficacy were determined for each studied LB. In independent trials, broilers challenged with S. Enteritidis on day of hatch received phage therapy from 6 to 10 days of age (early treatment), and from 31 to 35 days of age (later treatment). S. Enteritidis analyses were performed before treatment and at 1, 4, 7 and 10 days post-treatment (dpt) in both trials. Partial DNA sequence analysis of each LB revealed close similarity to the Ackermannviridae family. LBs lysed different Salmonella enterica serovars, while other tested bacteria were refractory. An in-vitro reduction of 1.49, 0.65 and 0.58 log10 CFU/mL in S. Enteritidis number was obtained after co-incubation for 3 h with each LB. Both in vivo trials showed a significant reduction in the average number of intestinal S. Enteritidis calculated after phage therapy compared with controls. However, the highest efficiency was found in the later therapy, which resulted in a reduction of 1.08 log10 CFU/g in the average from 4 to 10 dpt, showing potential for future use as a pre-harvest strategy to reduce the S. Enteritidis intestinal colonization in broilers on farms.

Salmonella enterica subsp. enterica ( S .) serovar Enteritidis is one of the main pathogens involved in food-borne diseases worldwide. In epidemiological investigations of food-related salmonellosis, subtyping is necessary to improve preventive and control measures. Single-enzyme amplified fragment length polymorphism (SE-AFLP) analysis is a modified AFLP that uses only one restriction enzyme to produce DNA fragments that are selectively amplified by PCR. In order to assess the applicability of SE-AFLP in S. Enteritidis typing, one hundred and eight strains isolated from poultry, swine and also from human salmonellosis outbreaks in Southern Brazil were analyzed. Strains from other countries and six different S. enterica serovars were also included as controls. SE-AFLP was able to distinguish S . Enteritidis from the other S. enterica serovars analyzed. However, most of S . Enteritidis strains isolated from poultry, salmonellosis outbreaks and most of the strains from other countries shared the same predominant pattern. The low genetic diversity identified in S . Enteritidis suggests that the strains analyzed are clonally related and one predominant SE-AFLP genotype is widely spread in Southern Brazil.

Salmonella enterica sorovar ( S .) Enteritidis e uma das principais bacterias envolvidas em surtos de infeccao alimentar em humanos decorrentes do consumo de produtos de origem animal. Nas investigacoes epidemiologicas, a subtipificacao fenotipica e genotipica permitem verificar diferencas ou similaridades entre linhagens, as quais podem indicar sua origem, auxiliando os programas de controle e prevencao do patogeno. No presente trabalho, foram analisados os padroes de resistencia a antimicrobianos, fagotipificacao, macrorestricao de DNA seguida de eletroforese em campo pulsado (PFGE) e polimorfismo de comprimento do fragmento amplificado utilizando uma unica enzima de restricao (SE-AFLP) de 107 linhagens de S . Enteritidis, sendo 53 isoladas de aves e seus produtos (carcacas, carne, visceras e ambiente) e uma de origem suina. Foram ainda analisadas 29 linhagens isoladas de alimentos e 14 isoladas de humanos envolvidos em surtos de salmonelose notificados no Rio Grande do Sul, uma amostra de referencia (ATCC 13076), alem de 9 linhagens isoladas na Europa e Africa. Na comparacao entre amostras isoladas de aves e de surtos de salmonelose, as linhagens de origem avicola foram significativamente mais resistentes a antimicrobianos do que as isoladas de humanos e, embora nao tenha sido encontrada relacao entre os genotipos de PFGE e os padroes de resistencia, a associacao de ambas as tecnicas possibilitou uma melhor caracterizacao de S . Enteritidis, podendo ser uteis como marcadores epidemiologicos. Por outro lado, SE-AFLP agrupou a maioria das linhagens de S . Enteritidis num padrao principal. Paralelamente, na comparacao de tecnicas genotipicas com base em PCR, SE-AFLP apresentou maior capacidade de discriminacao, embora inferior a verificada pela fagotipificacao e perfil de resistencia a antimicrobianos. Assim, foi recomendado que esta tecnica deve ser utilizada em associacao com outras metodologias na tipificacao de S . Enteritidis. Posteriormente, na caracterizacao do conjunto de linhagens de S . Enteritidis, foram identificados 13 diferentes padroes de resistencia a antimicrobianos, alem de 12 padroes de PFGE e 3 de SE-AFLP. As tecnicas genotipicas demonstraram que existe um genotipo predominante de S . Enteritidis no Rio Grande do Sul, o qual esta presente em aves e produtos relacionados, alem de alimentos e humanos envolvidos em surtos de salmonelose, sugerindo que estas linhagens possam derivar de uma fonte comum, tendo provavel relacao clonal. Embora havendo um genotipo predominante de S . Enteritidis, a associacao das tecnicas propostas possibilitou a melhor caracterizacao do patogeno.

The present study analyzes the characteristics of Salmonella spp. from broiler chicken farms in Brazil. In total, 82 Salmonella spp. strains were characterized by serotyping, determining susceptibility to antimicrobials, and using pulsed-field gel electrophoresis (PFGE). Fifteen Salmonella serotypes were identified, among which Minnesota (40.24%), Infantis (14.63%), Heidelberg (7.31%), Senftenberg (6.09%), and Mbandaka (6.09%) were the most frequent. Salmonella Minnesota occurred mostly in the state of Mato Grosso do Sul and in one of the broiler companies surveyed. Approximately 60% of the strains were resistant to at least one of the antimicrobials tested. From these isolates, 17.07% were resistant to only one antimicrobial (tetracycline or streptomycin), and 9.75% were resistant to 3 or more antimicrobial classes. Thirteen resistance profiles were characterized, the most frequent of which were the resistance to tetracycline (15.85%); to the combination of trimethroprim with sulfamethoxazole, and tetracycline (10.97%); and to the combination of streptomycin and tetracycline (9.75%). Multiple correspondence analysis revealed that susceptibility or resistance of the analyzed strains and also particular Salmonella serotypes were associated with broiler-producing companies where the samples were collected. Strains presented high intraserotype genetic variability, as shown by the 64 PFGE profiles, suggesting the existence of several contamination sources in the surveyed farms.

Conventional culturing methods enable the detection of Campylobacter in broiler flocks. However, laboratory culture of Campylobacter is laborious because of its fastidious behavior and the presence of competing nontarget bacteria. This study evaluated different protocols to isolate Campylobacter from broiler litter, feces, and cloacal and drag swabs. Samples taken from commercial Brazilian broiler flocks were directly streaked onto Preston agar (PA), Campy-Line agar (CLA), and modified charcoal cefoperazone deoxycholate agar (mCCDA) and also enriched in blood-free Bolton broth (bfBB) for 24 and 48 h followed by plating onto the different selective media. Higher numbers of Campylobacter-positive cloacal and drag swab samples were observed using either direct plating or enrichment for 24 h before plating onto PA, compared with enrichment for 48 h (P < 0.05). Furthermore, direct plating was a more sensitive method to detect Campylobacter in broiler litter and feces samples. Analysis of directly plated samples revealed that higher Campylobacter levels were detected in feces streaked onto PA (88.8%), cloacal swabs plated onto mCCDA (72.2%), drag swabs streaked onto CLA or mCCDA (69.4%), and litter samples inoculated onto PA (63.8%). Preston agar was the best agar to isolate Campylobacter from directly plated litter samples (P < 0.05), but there was no difference in the efficacies of PA, mCCDA, and CLA in detecting Campylobacter in other samples. The isolated Campylobacter strains were phenotypically identified as Campylobacter jejuni or Campylobacter coli. The predominant contaminant observed in the Campylobacter cultures was Proteus mirabilis, which was resistant to the majority of antimicrobial agents in selective media. Together, these data showed that direct plating onto PA and onto either CLA or mCCDA as the second selective agar enabled the reliable isolation of thermophilic Campylobacter species from broiler samples. Finally, Campylobacter was detected in all broiler flocks sampled.

Two experiments were undertaken to evaluate the bacterial load in recycled litter between broiler flocks following addition of quicklime (T1), windrowing (T2), shallow fermentation (T3), and control (no intervention, T4). The first experiment was developed in field conditions in which the broiler houses were accompanied by 6 consecutive flocks and the effect of the treatments was assessed on enterobacteria and aerobic mesophiles. The second experiment was conducted in an experimental broiler house with recycled litter for assessment of Salmonella Enteritidis phage type 4 (SE PT4). In the field study, T3 presented the best results in reducing enterobacteria in broiler litter in relation to the other treatments, with the highest reduction occurring in the first 3 flocks, tending to stabilization from the fourth flock onward for all the treatments assessed. From the third to sixth flocks, enterobacteria level at the end of the treatments (d 12) was lower than the average in the fresh litter, except in T4. All treatments reduced aerobic mesophiles throughout the flocks, where T2 showed the highest reduction. The percentage of dry matter in the broiler litter diminished in T4 and increased in T3 over the course of the flocks. In the second experiment, the drop in the SE PT4 level in the broiler litter first occurred in T2 and T3. However, all the treatments except for T4 eliminated SE PT4 within 12 d. The temperature of the broiler litter in T2 was higher in relation to the other treatments. The results show that litter treatment prior to reutilization by the successive broiler flock is required to reduce the level of residual bacteria. The fermentative treatments (T2 and T3) were found to be superior to the others in terms of reducing the bacterial load, with shallow fermentation standing out with the highest reduction of enterobacteria and equivalent SE PT4 elimination when compared to windrowing.

To investigate antimicrobial resistance, 96 Salmonella enterica subspecies enterica serovar Enteritidis strains isolated from salmonellosis outbreaks and poultry-related products obtained in southern Brazil were analyzed. Macrorestriction patterns, obtained by pulsed-field gel electrophoresis and phage types, were assessed. Although 43.75% of samples were sensitive to all drugs tested, resistance to sulfonamide (34.37%), trimethoprim-sulfamethoxazole (25.00%), nalidixic acid (14.58%), streptomycin (2.08%), gentamicin, and tetracycline (1.04%) was identified. Furthermore, 89.60% of strains belonged to phage type 4, and a predominant pulsed-field gel electrophoresis genotype represented by 82.29% of the strains was identified, suggesting that a clonal group was distributed in poultry, food, and human isolates. Although it was not possible to associate strains from different sources, the occurrence of antimicrobial-resistant Salmonella Enteritidis strains supports the need to establish monitoring programs to identify the emergence of potential resistance patterns and to direct policies for use of these drugs in food-producing animals.

Salmonella (S.) Enteritidis tem sido uma das bactérias mais implicadas em casos de infecções alimentares, sendo a investigação de sua epidemiologia realizada por diferentes métodos fenotípicos e genotípicos. Dentre as técnicas de tipificação de bactérias, a técnica de single-enzyme amplified fragment length polymorphism (SE-AFLP) é um dos métodos mais recentemente descritos, apresentando boa confiabilidade e fácil aplicação. No presente trabalho, a SE-AFLP foi comparada com as técnicas fenotípicas de fagotipificação (PT) e determinação da sensibilidade a antimicrobianos (DSA) e genotípicas de rep-PCR (seqüências repetitivas REP, ERIC e BOX) e detecção de genes de virulência (genes spvR e spvC). Foram analisadas 20 amostras de S. Enteritidis, sendo onze isoladas de suínos da Região Sul do Brasil e nove amostras oriundas de outros países. A caracterização destas amostras pelas técnicas de PT, DSA, presença de genes de virulência e rep-PCR foi descrita em um trabalho anterior. O poder discriminatório obtido pelas técnicas foi calculado pelo índice de diversidade de Simpson (D). A SE-AFLP encontrou um número maior de perfis e obteve uma maior capacidade discriminatória do que as outras técnicas genotípicas, embora seu D tenha sido menor do que o das técnicas fenotípicas. Desta forma, ficou demonstrada a importância da utilização conjunta de técnicas fenotípicas e genotípicas na caracterização de amostras de S. Enteritidis. Salmonella (S.) Enteritidis is one of the most reported bacteria in outbreaks of food borne disease and its epidemiology has been investigated by different phenotyping and genotyping based methods. Fingerprinting by SE-AFLP is one of the most recent methods, presenting easy application and reproducibility. In the present study, the SE-AFLP method was compared with two phenotyping techniques; phage typing (PT) and antimicrobial susceptibility (DSA) and two genotyping techniques; rep- PCR (repetitive sequences REP, ERIC and BOX) and detection of virulence genes (genes spvR and spvC). For these, 20 samples were analyzed, being eleven of swine origin from the Southern Region of Brazil and nine samples from other countries. The techniques of phage typing, DSA, presence of virulence genes and rep-PCR were performed in a previous study. For the accomplishment of the SE-AFLP, the technique was performed using the restriction enzyme Hind III. The discriminatory power obtained by the techniques was calculated by the Simpson’s index of diversity (D). Between the genotypic based techniques, the SEAFLP evidenced a higher number of profiles and obtained a best discriminatory capacity. However, the D was lower than both phenotypic based techniques. The results evidenced the importance of the combined use of phenotypic and genotypic techniques for Salmonella Enteritidis typing.

A pleuropneumonia suína, causada por Actinobacillus pleuropneumoniae, é uma doença caracterizada pela apresentação fibrino-hemorrágica com pleurite adesiva. A enfermidade está presente em todos os países produtores de suínos, sendo responsável por prejuízos econômicos elevados. No Brasil e no mundo, diversos grupos vêm conduzindo estudos na busca por um melhor entendimento da doença e de sua epidemiologia. Avanços importantes foram obtidos, entre os quais a caracterização dos fatores de virulência, implicados na apresentação clínica da enfermidade; e a aplicação de novos métodos de diagnóstico. A difusão das técnicas de biologia molecular como ferramenta diagnóstica em Medicina Veterinária tem contribuindo para a identificação de Actinobacillus pleuropneumoniae. Nesta revisão, são abordados os aspectos mais recentes sobre a patogênese e o diagnóstico deste importante patógeno.

A pleuropneumonia suína (PPS) provoca prejuízos significativos na suinocultura no mundo. O agente etiológico é a bactéria Actinobacillus pleuropneumoniae (App), que apresenta 15 sorotipos descritos, os quais variam consideravelmente em relação a sua patogenicidade. Nesse sentido, a precisa caracterização patotípica desta bactéria é de grande importância para a adoção de medidas de controle e profilaxia. O diagnóstico e a sorotipificação deste patógeno são realizados pelas técnicas microbiológicas convencionais. Entretanto, problemas nestes esquemas podem ser observados, especialmente em isolados de rebanhos sem histórico de PPS. No Brasil, diversos esforços vêm sendo aplicados no sentido de desenvolver técnicas moleculares que auxiliem no diagnóstico da infecção crônica ocasionada por este agente, principalmente em rebanhos presumidamente sadios e com infecção subclínica. Nesta revisão, são discutidos os resultados obtidos na caracterização de isolados de A. pleuropneumoniae e espécies relacionadas provenientes tanto de suínos com PPS, como de animais presumidamente isentos da infecção. Apresentamos, ainda, perspectivas para o desenvolvimento de metodologias que possibilitem o diagnóstico precoce e a melhor compreensão dos mecanismos de virulência deste patógeno. Swine pleuropneumonia is responsible for severe losses in swine breeding farms around the world. The aethiological agent, A. pleuropneumoniae, is classified according to different degrees of pathogenicity in 15 serotypes. The correct identification and serological classification of this bacterium is very important for the adoption of control measures. The diagnosis of swine pleuropneumonia is performed by conventional microbiological techniques, however problems in A. pleuropneumoniae identification have been reported. In Brazil, some studies applying molecular tests have been developed specially in isolates from swine herds with subclinical and chronic infections. In this review, we discuss the results on molecular characterization of A. pleuropneumoniae and related species from herds with or without pleuropneumonia. Moreover, we also discuss the perspectives to development early diagnostic methods and to improve understand of pathogenesis mechanisms of these bacteria.

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We studied the on-farm variety of thermotolerant Campylobacter strains isolated from field samples received over a 12-mo period from four broiler-producing companies in southern Brazil. In total, 515 of 807 (63.8%) of analyzed samples were found to be Campylobacter-positive. Campylobacter jejuni and C. coli were detected; the first one being more frequently isolated (98.2%). The highest antimicrobial resistance levels in a subset of 80 C. jejuni strains were found against enrofloxacin (89.5%) and ciprofloxacin (83.3%). Most of the 28 DNA macrorestriction profiles identified in C. jejuni were unique to each sampled broiler company. Genetically related C. jejuni populations were detected on different broiler farms integrated to the same company on different sampling occasions. Undistinguished strains were found in the indoor environment and in broilers on the same farm. The finding of recurrent strains on integrated farms suggests that particular factors or management practices may play a role in the dispersion or carry-over of C. jejuni in the studied broiler companies. Made available in DSpace on 2021-08-03T18:00:25Z (GMT). No. of bitstreams: 1 final8623.pdf: 449623 bytes, checksum: 6eed61eaebd20828751f651ca17457de (MD5) Previous issue date: 2021 Applied research note.

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Uma análise preliminar da rotina laboratorial da Embrapa Suínos e Aves entre os anos de 2010 a 2014 mostrou que foram isoladas 1.141 cepas de Campylobacter de material avícola, compreendendo as espécies C. Jejuni e C. Coli.

Projeto: 03.08.06.004.

Projeto: 03.08.06.004.

Projeto: 11.11.11.111.