Comparação de métodos de diagnóstico para o vírus da laringotraqueíte

10

Caracterização molecular de isolados brasileiros do vírus da laringotraqueíte das galinhas

02

Detection and quantification of Campylobacter spp. in Brazilian poultry processing plants

Introduction: Campylobacteriosis is considered the most common bacteria-caused human gastroenteritis in the world. Poultry is a major reservoir of Campylobacter. Human infection may occur by consumption of raw and undercooked poultry or by contamination of other foods by these items. The aim of this study was to assess the prevalence of Campylobacter spp. in poultry processing plants with conventional culture method and real-time PCR. Methodology: A total of 108 poultry processing plant samples were collected to test with conventional microbiology and qPCR. Sampling included cloacal swabs, swabs of transport crates (before and after the cleaning and disinfection process) and carcasses (after the chiller, cooled at 4°C and frozen at −12°C). Results: Positivity in cloacal swabs indicated that poultry arrived contaminated at the slaughterhouse. Contamination in transport cages was substantially increased after the cleaning process, indicating that the process was ineffective. The detection of Campylobacter on carcasses was higher than that on cloacal swabs, which could indicate cross-contamination during the slaughtering process. Conventional microbiology and molecular methods revealed a prevalence of 69.4% and 43.5%, respectively. Lower detection by qPCR can be attributed to the high specificity of the kit and to biological components that could inhibit PCR reactions. Conclusions: Our results indicate that poultry arrive contaminated at the slaughterhouse and that contamination can increase during the slaughtering process due to cross-contamination. The isolation of Campylobacter in cooled and frozen carcasses corroborates the bacterial survival even at temperatures considered limiting to bacterial growth which are routinely used for food preservation

Prevalence and distribution of pathogenic genes in Campylobacter jejuni isolated from poultry and human sources

Introduction: Campylobacter jejuni is one of the most common bacterial causes of human gastroenteritis. Despite its public health importance, the virulence factors and mechanisms underlying C. jejuni pathogenesis remain poorly understood and the relationships between these genes and the sources of the strains are not clear. We aimed to determine the virulence profiles of C. jejuni isolated from poultry and human cases of Campylobacteriosis. Methodology: A total of 50 strains of C. jejuni isolated from poultry and human cases of Campylobacteriosis were screened by polymerase chain reaction (PCR) for the presence of six pathogenic genes (flaA, iam, wlaN, cdtA, cdtB, cdtC). Results: A total of 40% (10/25) of the human isolates presented only one virulence marker. In contrast, 64% (16/25) of the poultry-derived strains showed four or five virulence markers. cdtA and flaA occurred more frequently in poultry-derived strains than in human strains. Ten different virulence profiles were observed among the human isolates and 11 among the poultry strains. Only four profiles were common to both sources: profiles 3 (flaA, cdtA, cdtB, and cdtC), 5 (cdtA and cdtB), 7 (flaA and cdtB), and 10 (iam, flaA, cdtA, cdtB, and cdtC). The human-derived strains had a higher Shannon diversity index (1.9396) and Simpson index (0.8367), indicating a more diversified population than found in poultry (1.7742 and 0.7333, respectively). Conclusions: We found variations in the genetic profiles of the circulating strains based on the isolation source and genes that are potentially pathogenic to humans were detected in poultry-derived strains

Antimicrobial activity of poultry hatch baskets containing copper inserts

Commercial poultry hatcheries provide ideal conditions for the multiplication and spread of microorganisms. Formaldehyde is widely used as a disinfectant; however, it is harmful to human health and can cause abnormal morphology in chicks. An alternative microbiological control is the use of copper, a metallic antimicrobial agent for contact surfaces. The antimicrobial efficacy of copper surfaces has been established in healthcare environments. However, its use in the poultry chain is still limited. This study aimed to compare the antimicrobial activity of common polypropylene hatch baskets with hatch baskets composed of copper (polypropylene hatch baskets covered by copper hatch baskets; polypropylene hatch baskets with solid copper plates on the bottom; polypropylene hatch baskets covered by copper hatch baskets and with solid copper plates on the bottom). To simulate a hatching environment with high contamination, the eggs and hatching cabinet were not fumigated. Microbiological analysis of the hatching cabinet environmental, surface of hatch basket, and fluff were performed. The results indicated that the absence of bottom holes resulted in a higher volume of organic matter that interfered with the copper's antimicrobial activity. The presence of copper in the hatch baskets did not decrease microbial contamination under the conditions evaluated, confirming that the metal should only be used as a complement to standard hygiene and not as a substitute for surface disinfectants. Further analysis will evaluate the antimicrobial activity of hatch baskets composed only of copper and the ability of nanoparticles to remove the biofilms formed by bacteria isolated from the poultry environment

Detection of virulence genes in Salmonella Heidelberg isolated from chicken carcasses

During the last years, Brazilian government control programs have detected an increase of Salmonella Heidelberg in poultry slaughterhouses a condition that poses a threat to human health However, the reasons remain unclear. Differences in genetic virulence profiles may be a possible justification. In addition, effective control of Salmonella is related to an efficient epidemiological surveillance system through genotyping techniques. In this context, the aim of this study was the detection of 24 virulence-associated genes in 126 S. Heidelberg isolates. We classified the isolates into 56 different genetic profiles. None of the isolates presented all the virulence genes. The prevalence of these genes was high in all tested samples as the lowest number of genes detected in one isolate was 10/24. The lpfA and csgA (fimbriae), invA and sivH (TTSS), and msgA and tolC (intracellular survival) genes were present in 100% of the isolates analyzed. Genes encoding effector proteins were detected in the majority of SH isolates. No single isolate had the sefA gene. The pefA gene was found in only four isolates. We have also performed a screening of genes associated with iron metabolism: 88.9% of isolates had the iroN geneand 79.4% the sitC gene. Although all the isolates belong to the same serotype, several genotypic profiles were observed. These findings suggest that there is a diversity of S. Heidelberg isolates in poultry products. The fact that a single predominant profile was not found in this study indicates the presence of variable sources of contamination caused by SH. The detection of genetic profiles of Salmonella strains can be used to determine the virulence patterns of SH isolates

Detection of virulence genes in Salmonella Heidelberg isolated from chicken carcasses

During the last years, Brazilian government control programs have detected an increase of Salmonella Heidelberg in poultry slaughterhouses a condition that poses a threat to human health However, the reasons remain unclear. Differences in genetic virulence profiles may be a possible justification. In addition, effective control of Salmonella is related to an efficient epidemiological surveillance system through genotyping techniques. In this context, the aim of this study was the detection of 24 virulence-associated genes in 126 S. Heidelberg isolates. We classified the isolates into 56 different genetic profiles. None of the isolates presented all the virulence genes. The prevalence of these genes was high in all tested samples as the lowest number of genes detected in one isolate was 10/24. The lpfA and csgA (fimbriae), invA and sivH (TTSS), and msgA and tolC (intracellular survival) genes were present in 100% of the isolates analyzed. Genes encoding effector proteins were detected in the majority of SH isolates. No single isolate had the sefA gene. The pefA gene was found in only four isolates. We have also performed a screening of genes associated with iron metabolism: 88.9% of isolates had the iroN gene and 79.4% the sitC gene. Although all the isolates belong to the same serotype, several genotypic profiles were observed. These findings suggest that there is a diversity of S. Heidelberg isolates in poultry products. The fact that a single predominant profile was not found in this study indicates the presence of variable sources of contamination caused by SH. The detection of genetic profiles of Salmonella strains can be used to determine the virulence patterns of SH isolates

Development of copper hatch baskets and evaluation of the productive indexes of a commercial hatchery

Background: The dissemination of pathogenic microorganisms in hatcheries leads to a higher number of contaminated eggs, causing reduction in hatchability and increase of discarded chicks. Sanitation programs are crucial for maximum hatchability and chick quality. Efforts have been made to find alternative approaches to the conventional disinfectants, and surfaces with copper, which have antimicrobial properties, could assist in this process. However, the possible adverse effects of copper surfaces on chicks in hatcheries have not yet been evaluated. The present study aimed at developing hatch baskets composed of copper and evaluating the effect of these baskets on the productive indexes of a hatchery. Materials, Methods & Results: For this experiment, 3.15 kg hatch tray prototypes with 99.9% Cu (Cu11000) were developed to fit inside conventional polypropylene hatch baskets (580 × 755 × 83 mm). Six polypropylene hatch baskets (control group) and six polypropylene hatch baskets covered by 99.9% copper (Cu11000) hatch trays (test group) were evaluated during 5 hatchings. Hatched eggs and chicks remained in contact with the hatch basket surfaces for at least 72 h, corresponding to the entire period in which they were located in the hatcher. Cleaning and disinfection programs of the hatchery were not modified. The level of microbial contamination on the hatch baskets was evaluated at 6 different periods: 0 h (initial contamination after disinfection and egg transfer to the trays); 24 h, 30 h, 45 h and 60 h after the first sampling; and at the moment when chicks were removed from the hatching cabinet and transferred to the chick-holding room (> 60 h). Counting of total moulds and yeasts, mesophilic microorganisms, Enterobacteria and Escherichia coli colonies was performed. The number of hatched chicks, non-hatched eggs, and chicks discarded were registered for each hatching. Microbiologic analyses showed no growth on hatch baskets neither of the test group nor on those of the control group, regardless of the period evaluated. No significant difference was found between the two groups in the counts of hatched chicks, non-hatched eggs, and chicks discarded. Discussion: The antimicrobial efficacy of copper surfaces has been established for a variety of bacteria and fungi, including in the healthcare environment. In addition, antimicrobial resistance to copper is extremely rare because of copper’s multisite kill mechanism and other mostly nonspecific damage mechanisms. Several copper applications have been established; however, the potential adverse effects of using copper surfaces in hatcheries on chicks or on hatchery productive indexes had not yet been evaluated. The analyses performed in this study did not show microbiological growth. The results showed that the copper surface did not cause any significant adverse effects on chicks. The hatched chicks were visually healthy, and no significant difference was found between the numbers of chicks discarded in the control and test groups. Since the production parameters were not altered or impaired in the present study, it is possible to conclude that the use of copper surfaces in hatcheries can be an effective tool in the microbiological control of these environments. Nevertheless, copper alloys lend themselves to the creation of self-sanitizing surfaces that should be used as a complement and not as a substitute for standard cleaning and disinfection practices

Wooden breast e white striping : ocorrência em três empresas avícolas

To increase the amount of meat produced, researchers have promoted intensive genetic selection for growth rate and muscling and have improved nutrition and management conditions. However, there has been an increase in the number of reports of breast muscle myopathies observed in poultry processing plants, including white striping (WS) and wooden breast (WB). This study aimed to evaluate and to compare the occurrence of WS and WB myopathies in three poultry processing plants and to perform an anatomopathological characterization, including macroscopic and microscopic analyses. A total of 408,334 carcasses were condemned or downgraded due to the presence of WB or WS, which represents 0.73% of the total number of slaughtered animals during the evaluated period. WB was more frequent than WS, but the occurrence of each myopathy varied significantly according to each establishment. WB was more frequent in the establishment which includes only male flocks, an average age of 45 days, and an average live weight of 2775g (B). WS was more frequent in establishment with male, female and mixed flocks, average ages ranging from 41 to 44 days, and average live weight 1731g-2830g (A). It is probably related with specific condition of each poultry company, including genetics, age, nutrition and management conditions. Macroscopically, WB and WS lesions are characterized by hypertrophy and stiffness of the pectoralis major muscle. Under microscopy, the myopathies showed similarities regarding the detected histological abnormalities, characterized by a process of myodegeneration, although the connective tissue infiltrate was more severe in the breasts with WB than in those with WS myopathy. The results found in this study demonstrate that the rates of condemnation for these myopathies are high, vary significantly among the analyzed companies and may cause major economic losses for the productive sector in the region.Para melhorar a quantidadede carne produzida, os pesquisadores têm promovido ao longo dos anos uma seleção genética intensiva para a taxa de crescimento e desenvolvimento de músculos, além de melhorias nas condições nutricionais, sanitárias e de manejo. No entanto, houve um aumento no número de relatos de miopatias dos músculos do peito observados em abatedouros-frigoríficos de aves, incluindo white striping (WS) e wooden breast (WB). O objetivo deste estudo foi avaliar a ocorrência de WB e WS em três abatedouros-frigoríficos de aves e realizar uma caracterização anatomopatológica, incluindo análises macroscópicas e microscópicas. Um total de 408.334 carcaças foi condenado (total ou parcialmente) devido à presença WB ou WS, o que representou 0,73% do número total de animais abatidos durante o período avaliado. Apesar de a ocorrência de WB ter sido maior do que a de WS, a frequência de cada uma variou significativamente de acordo com o estabelecimento. WB foi mais frequente no estabelecimento que incluía apenas lotes de machos, com média de 45 dias de idade e peso médio ao abate de 2775g (B). WS foi mais frequente no estabelecimento com lotes de machos, fêmeas e mistos, com idade entre 41 e 44 dias e peso médio ao abate entre 1731g-2830g (A). Isto pode ser justificado por condições específicas de cada empresa, incluindo genética, idade das aves, nutrição e condições de manejo. Macroscopicamente, as lesões de WB e de WS foram caracterizadas principalmente por hipertrofia e rigidez do músculo pectoralis major. À microscopia, ambas as miopatias mostraram semelhanças em relação às anormalidades histológicas detectadas, caracterizadas principalmente por um processo de miodegeneração. Nos músculos apresentando WB, o infiltrado de tecido conjuntivo foi mais intenso quando comparado àqueles com WS. Os resultados encontrados neste trabalho demonstram que os índices de condenação por essas miopatias são altos, variam significativamente entre as empresas analisadas e podem causar grandes perdas econômicas para o setor produtivo da região

Avian pathogenic Escherichia coli (APEC) and uropathogenic Escherichia coli (UPEC) : characterization and comparison

Introduction: Avian pathogenic E. coli (APEC) and uropathogenic E. coli (UPEC) are responsible for avian colibacillosis and human urinary tract infections, respectively. There are genetic similarities between the APEC and UPEC pathotypes, suggesting the APEC strains could be a potential reservoir of virulence and antimicrobial-resistance genes for the UPEC strains. This study aimed to characterize and compare APEC and UPEC strains regarding the phylogroup classification, pathogenicity and antimicrobial susceptibility. Methodology: A total of 238 APEC and 184 UPEC strains were selected and characterized. The strains were assayed for antimicrobial susceptibility and classified into phylogenetic groups using a multiplex-PCR protocol. In addition, the APEC strains had previously been classified according to their in vivo pathogenicity. Results: The results showed that both pathotypes had variation in their susceptibility to most of the antimicrobial agents evaluated, with few strains classified as multidrug resistant. The highest resistance rate for both pathotypes was to amoxicillin. Classifying the APEC and UPEC strains into phylogenetic groups determined that the most frequently frequencies were for groups D and B2, respectively. These results reflect the pathogenic potential of these strains, as all the UPEC strains were isolated from unhealthy patients, and most of the APEC strains were previously classified as pathogenic. Conclusions: The results indicate that distribution into phylogenetic groups provided, in part, similar classification to those of in vivo pathogenicity index, as it was possible to adequately differentiate most of the pathogenic and commensal or low-pathogenicity bacteria. However, no relationship could be found between the specific antimicrobial agents and pathogenicity or phylogenetic group for either pathotype