Molecular detection of chicken parvovirus in broilers with enteric disorders presenting curving of duodenal loop, pancreatic atrophy, and mesenteritis.

Enteric disorders are an important cause of economic losses in broiler chickens worldwide. Several agents have been associated with enteric problems, such as viruses, bacteria, and parasites. In this study, broiler chickens showing signs of enteric disorders were subjected to molecular diagnosis for several viral agents and also for pathological examination for elucidating this problem. Thus, the chickens were screened for avian nephritis virus (ANV), chicken astrovirus (CAstV), avian rotavirus (ArtV), avian reovirus (AReoV), infectious bronchitis virus (IBV), fowl adenovirus group I (FAdV-1), and chicken parvovirus (ChPV). Postmortem examinations revealed a curving of the duodenal loop (J-like appearance) and intestines filled with liquid and gaseous content. Histopathological analysis of the duodenal loop showed pancreatic atrophy, acute mesenteritis, and enteritis. PCR results showed that ChPV was the sole viral agent detected in samples with lesions such as the curved duodenal loop and pancreatic atrophy. Molecular characterization of the nucleotide and deduced amino acid sequences revealed a high similarity with other strains of ChPV from Brazil, Canada, United States, Europe, and Asia. These findings suggest an association between ChPV and the development of enteritis, pancreatitis, and pancreatic atrophy, which may lead to curling of the duodenal loop. Together, these alterations may disrupt the normal functioning of the digestive system, diminishing digestion and the absorption of dietary nutrients and consequently leading to reduced weight gain, flock impairment, dwarfism, and an elevated feed conversion rate.

Virulence and antimicrobial resistance of Klebsiella pneumoniae isolated from passerine and psittacine birds.

Klebsiella pneumoniae is considered one of the most important Gram-negative opportunistic pathogens. The contact between humans and birds poses health risks to both. The aim of this study was to investigate the resistance and virulence of K. pneumoniae isolates from psittacines and passerines, seized from illegal trade in Brazil. We analysed 32 strains isolated from birds of the orders Psittaciformes and Passeriformes by polymerase chain reaction (PCR) for virulence factor genes. Antibiotic resistance was assessed by disk diffusion assay and PCR. The results indicated that fimH (100%), uge (96.8%), kfu (81.2%) and irp-2 (68.7%) were the most common virulence genes, followed by kpn (46.8%), K2 (43.7%), mrkD (34.3%) and iroN (15.6%). The combination of virulence genes resulted in a great diversity of genotypes and the heterogeneity of the strains is also confirmed in the analysis by amplified fragment length polymorphism. The susceptibility profiles of the K. pneumoniae showed 25% of multiple antibiotic resistance strains. We identified seven strains that presented non-extended spectrum beta lactamase blaSHV variants SHV-1 and SHV-11 and one strain positive to the blaTEM-1 gene. Plasmid-mediated quinolone resistance was present in 10 strains (10/32). The data obtained in this study reveal the pathogenic potential of this pathogen and highlight the need for surveillance and monitoring.

Isolation and molecular identification of lactic acid bacteria and Bifidobacterium spp. from faeces of the blue-fronted Amazon parrot in Brazil.

In Brazil, the blue-fronted Amazon parrot (Amazona aestiva) is a common pet. The faecal microbiota of these birds include a wide variety of bacterial species, the majority of which belong to the Gram-positive lactic acid bacteria (LAB) clade. The aim of this study was to investigate differences in the diversity and abundance of LAB and Bifidobacterium spp. in the cloacae between wild and captive birds and to select, identify and characterise LAB for consideration as a parrot probiotic. Cloacal swabs were collected from 26 wild and 26 captive birds. Bacterial DNA was extracted, and the 16S rRNA genes were amplified. The numbers of PCR-positive Enterococcus, Pediococcus, and Lactobacillus species isolated from wild and captive birds were significantly different (P<0.05). Enterococcus was the most frequently isolated genus, followed by Pediococcus, Lactobacillus, Lactococcus and Bifidobacterium. Enterococcus faecium, Pediococcus pentosaceus, Lactococcus lactis, Lactobacillus coryniformis, Lactobacillus sanfranciscensis and Bifidobacterium bifidum were the most frequently isolated species from all birds. This study increases our understanding of the faecal microbiota, and may help to improve the nutrition and habitat management of captive and wild parrots. The bacterial population identified in the faecal microbiota of clinically healthy wild and captive parrots can serve as a database to analyse variations in the gut microbiota of pathogen-infected parrots and to develop probiotics specific to these genera.

Overcrowding stress decreases macrophage activity and increases Salmonella Enteritidis invasion in broiler chickens.

Overcrowding stress is a reality in the poultry industry. Chickens exposed to long-term stressful situations present a reduction of welfare and immunosuppression. We designed this experiment to analyse the effects from overcrowding stress of 16 birds/m(2) on performance parameters, serum corticosterone levels, the relative weight of the bursa of Fabricius, plasma IgA and IgG levels, intestinal integrity, macrophage activity and experimental Salmonella Enteritidis invasion. The results of this study indicate that overcrowding stress decreased performance parameters, induced enteritis and decreased macrophage activity and the relative bursa weight in broiler chickens. When the chickens were similarly stressed and infected with Salmonella Enteritidis, there was an increase in feed conversion and a decrease in plasma IgG levels in the stressed and Salmonella-infected birds. We observed moderate enteritis throughout the duodenum of chickens stressed and infected with Salmonella. The overcrowding stress decreased the macrophage phagocytosis intensity and increased Salmonella Enteritidis counts in the livers of birds challenged with the pathogenic bacterium. Overcrowding stress via the hypothalamic-pituitary-adrenal axis that is associated with an increase in corticosterone and enteritis might influence the quality of the intestinal immune barrier and the integrity of the small intestine. This effect allowed pathogenic bacteria to migrate through the intestinal mucosa, resulting in inflammatory infiltration and decreased nutrient absorption. The data strengthen the hypothesis that control of the welfare of chickens and avoidance of stress from overcrowding in poultry production are relevant factors for the maintenance of intestinal integrity, performance and decreased susceptibility to Salmonella infection.

Cellulitis lesions in broiler chickens are induced by Escherichia coli Vacuolating Factor (ECVF).

Escherichia coli Vacuolating Factor (ECVF) is a heat-labile, vacuolating cytotoxin produced by avian pathogenic E. coli (APEC) isolated from avian cellulitis lesions. In this report, we intend to demonstrate that purified ECVF induces the inflammatory process of cellulitis. Our group is the first to demonstrate the effect of ECVF in a histological analysis by in situ inoculation of broiler chickens with purified ECVF. The animals were inoculated with the APEC AC53 and with purified ECVF subcutaneously on their ventral surface (in the sternum region). The histological analysis showed different grades of an acute inflammatory response in the epidermis, dermis and panniculus. An increase in mRNA expression of the proinflammatory cytokine TNF-α was also demonstrated in the inflamed tissue. When ECVF was systemically administered, increased levels of TNF-α and IL-10 were observed in the serum. These results suggest that ECVF plays a key role in the inflammatory process associated with cellulitis that is mainly mediated by TNF-α. In addition, this inflammation can be downregulated by the anti-inflammatory cytokine IL-10.

Heat stress impairs performance and induces intestinal inflammation in broiler chickens infected with Salmonella Enteritidis.

Stressful situations reduce the welfare, production indices and immune status of chickens. Salmonella spp. are a major zoonotic pathogens that annually cause over 1 billion infections worldwide. We therefore designed the current experiment to analyse the effects of 31±1°C heat stress (HS) (from 35 to 41 days) on performance parameters, Salmonella invasion and small intestine integrity in broiler chickens infected with Salmonella Enteritidis. We observed that HS decreased body weight gain and feed intake. However, feed conversion was only increased when HS was combined with Salmonella Enteritidis infection. In addition, we observed an increase in serum corticosterone levels in all of the birds that were subjected to HS, showing a hypothalamus-pituitary-adrenal axis activation. Furthermore, mild acute multifocal lymphoplasmacytic enteritis, characterized by foci of heterophil infiltration in the duodenum, jejunum and ileum, was observed in the HS group. In contrast, similar but more evident enteritis was noted in the heat-stressed and Salmonella-infected group. In this group, moderate enteritis was observed in all parts of the small intestine. Lastly, we observed an increase in Salmonella counts in the spleens of the stressed and Salmonella-infected chickens. The combination of HS and Salmonella Enteritidis infection may therefore disrupt the intestinal barrier, which would allow pathogenic bacteria to migrate through the intestinal mucosa to the spleen and generate an inflammatory infiltrate in the gut, decreasing performance parameters.

Virulence and molecular aspects of Bordetella avium isolated from cockatiel chicks (Nymphicus hollandicus) in Brazil.

Bordetella avium is an opportunistic pathogen that presents tropism for ciliated epithelia, leading to upper respiratory tract disease in turkeys. This agent has also been associated with Lockjaw Syndrome in psittacine birds, but literatures describing the importance of this agent in such species are rare. The purpose of the present study was to report the first outbreak of B. avium infection in juvenile cockatiels demonstrating the Lockjaw Syndrome in Brazil and to investigate the antimicrobial resistance profile and phenotypic and genotypic characteristics of these strains. Surprising, the strains obtained from five infected cockatiel chicks from three different breeders from different Brazilian states showed a clonal relationship using the Pulsed Field Gel Electrophoresis and Single Enzyme Amplified Fragment Length Polymorphism techniques. The virulence potentials of the B. avium strains were assessed using tracheal adherence and cytotoxic effects on a VERO cell monolayer.

Acute heat stress impairs performance parameters and induces mild intestinal enteritis in broiler chickens: role of acute hypothalamic-pituitary-adrenal axis activation.

Studies on the environmental consequences of stress are relevant for economic and animal welfare reasons. We recently reported that long-term heat stressors (31 ± 1°C and 36 ± 1°C for 10 h/d) applied to broiler chickens (Gallus gallus domesticus) from d 35 to 42 of life increased serum corticosterone concentrations, decreased performance variables and the macrophage oxidative burst, and produced mild, multifocal acute enteritis. Being cognizant of the relevance of acute heat stress on tropical and subtropical poultry production, we designed the current experiment to analyze, from a neuroimmune perspective, the effects of an acute heat stress (31 ± 1°C for 10 h on d 35 of life) on serum corticosterone, performance variables, intestinal histology, and peritoneal macrophage activity in chickens. We demonstrated that the acute heat stress increased serum corticosterone concentrations and mortality and decreased food intake, BW gain, and feed conversion (P < 0.05). We did not find changes in the relative weights of the spleen, thymus, and bursa of Fabricius (P > 0.05). Increases in the basal and the Staphylococcus aureus-induced macrophage oxidative bursts and a decrease in the percentage of macrophages performing phagocytosis were also observed. Finally, mild, multifocal acute enteritis, characterized by the increased presence of lymphocytes and plasmocytes within the lamina propria of the jejunum, was also observed. We found that the stress-induced hypothalamic-pituitary-adrenal axis activation was responsible for the negative effects observed on chicken performance and immune function as well as for the changes in the intestinal mucosa. The data presented here corroborate with those presented in other studies in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.

Salmonella antibiotic-mutant strains reduce fecal shedding and organ invasion in broiler chicks.

We investigated the exposure to antibiotics in the production of antibiotic-mutant strains of Salmonella. Ten isolates of poultry origin were assayed for antibiotic susceptibilities. One strain of Salmonella Enteritidis, one of Salmonella Heidelberg, and one of Salmonella Typhimurium were selected to induce antimicrobial resistance. Each strain was exposed to high concentrations of streptomycin, rifampicin, and nalidixic acid, respectively. Parent and antibiotic-mutant strains were assayed for antibiotic susceptibilities using a commercial microdilution test and the disk susceptibility test. The strains were assessed for virulence genes and evaluated for fecal shedding, cecal colonization, organ invasion, and mean Salmonella counts after inoculation in 1-day-old chicks. The study revealed that exposure to high concentrations of streptomycin produced the antibiotic-mutant strain SE/LABOR/USP/08 and the exposure to rifampicin produced the antibiotic-mutant SH/LABOR/USP/08. These strains showed significantly reduced fecal shedding (P≤0.05) and organ invasion, persisting less than the parental strains and showing no clinical signs in inoculated chicks. High concentrations of nalidixic acid produced the antibiotic-mutant strain ST/LABOR/USP/08, which did not show any differences compared with the parent strain. Likewise, SE/LABOR/USP/08 did not show the expression of plasmid-encoded fimbriae (pefA) and plasmid virulence protein (spvC), suggesting that after exposure to streptomycin, the parent isolate lost the original gene expression, reducing fecal shedding and organ invasion in inoculated chicks.

Heat stress impairs performance parameters, induces intestinal injury, and decreases macrophage activity in broiler chickens.

Studies on environmental consequences of stress on animal production have grown substantially in the last few years for economic and animal welfare reasons. Physiological, hormonal, and immunological deficits as well as increases in animals' susceptibility to diseases have been reported after different stressors in broiler chickens. The aim of the current experiment is to describe the effects of 2 different heat stressors (31 +/- 1 and 36 +/- 1 degrees C/10 h per d) applied to broiler chickens from d 35 to 42 of life on the corticosterone serum levels, performance parameters, intestinal histology, and peritoneal macrophage activity, correlating and discussing the obtained data under a neuroimmune perspective. In our study, we demonstrated that heat stress (31 +/- 1 and 36 +/- 1 degrees C) increased the corticosterone serum levels and decreased BW gain and food intake. Only chickens submitted to 36 +/- 1 degrees C, however, presented a decrease in feed conversion and increased mortality. We also showed a decrease of bursa of Fabricius (31 +/- 1 and 36 +/- 1 degrees C), thymus (36 +/- 1 degrees C), and spleen (36 +/- 1 degrees C) relative weights and of macrophage basal (31 +/- 1 and 36 +/- 1 degrees C) and Staphylococcus aureus-induced oxidative burst (31 +/- 1 degrees C). Finally, mild multifocal acute enteritis characterized by an increased presence of lymphocytes and plasmocytes within the jejunum's lamina propria was also observed. The stress-induced hypothalamic-pituitary-adrenal axis activation was taken as responsible for the negative effects observed on the chickens' performance and immune function and also the changes of the intestinal mucosa. The present obtained data corroborate with others in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.

Índice de patogenicidade, produção de hemolisina e sorogrupo de amostras de Escherichia coli isoladas de aves de postura comercial / Pathogenicity index, production of hemolysin and serogroup of samples of Escherichia coli isolated from commercial laying hens

Este estudo avaliou o índice de patogenicidade, a produção de hemolisina e a determinação de sorogrupos de cepas deEscherichia coli isoladas de fígado de aves de postura comercial com um dia de idade. Para este estudo, foram analisados 32 lotes, dos quais 15 foram positivos para o isolamento de E. coli no fígado, totalizando vinte e quatro amostras. A patogenicidade dos isolados foi determinada por inoculação no saco aéreo de pintinhos e classificada como alta, intermediária, baixa ou não-patogênica. Os sorogrupos foram identificados utilizando um conjunto de antissoros anti-O (O1 a O180). A produção de hemolisina foi determinada por semeadura em ágar sangue de galinha (8%) e em placas de ágar sangue de carneiro (8%). Do total de amostras estudadas, 17 (70,83%) foram classificadas como não patogênica, 6 (25%) como de baixa patogenicidade e 1 (4,17%) de alta patogenicidade. Foram identificados 14 sorogrupos diferentes: O1, O2, O5, O8, O15, O18, O22, O36, O64, O70, O75, O115, O132, O141. Cinco cepas não tiveram o sorogrupo identificado. Com relação ao teste de produção de hemolisina, todas as cepas foram consideradas negativas, tanto para o teste realizado com ágar sangue de galinha quanto para o de carneiro. Os resultados obtidos neste estudo demonstram a importância de se identificar as cepas prevalentes deE. colinas diferentes regiões produtoras, podendo ser utilizados em estudos epidemiológicos.

This work evaluated the index of pathogenicity, the production of hemolysin and determination of serogroups in Escherichia coli strains isolated from liver of commercial laying hens with one day of age. Thirtytwo lots were analyzed, of which 15 were positive for the isolation ofE. coli in the liver, for a total of 24 samples. The pathogenicity in one-day-old chicks was determined by inoculation in air sac and was classified as high, intermediate or low pathogenicity, or non-pathogenic. Serogroups were identified using a set of anti-O antisera (O1 to O180). The production of hemolysin was determined by plating on chicken blood agar (8%) and sheep blood agar (8%). Of the samples studied, 17 (70.83%) were classified as non-pathogenic, 6 (25%) as low pathogenicity and 1 (4.17%) as high pathogenicity. Fourteen different serogroups were identified: O1, O2, O5, O8, O15, O18, O22, O36, O64, O70, O75, O115, O132 and O141, while 5 samples were non-typable. Regarding the test for production of hemolysin, all strains were considered negative for both the test performed with chicken blood agar and that with sheep blood agar. The results of this study demonstrate the importance of identifying the prevalent strains of E. coli in different producing regions, as this information can be used in epidemiological studies.

Prevention of Salmonella Typhimurium colonization and organ invasion by combination treatment in broiler chicks.

The effects in broiler chicks of treatment with a competitive exclusion (CE) product, an experimental dietary probiotic, and the abiotic beta-glucan on cecal colonization, organ invasion, and serum and intestinal IgG and IgA levels to Salmonella challenge was evaluated. Four groups of 1-d-old chicks were treated by oral gavage on d 1 with an appropriate dose of a commercial CE product. Three groups received daily doses of probiotic, beta-glucan, or both, for 6 d. Three other groups were fed daily from d 1 onwards with probiotic, beta-glucan, or both. Subgroups of 30 chicks from each group were challenged on d 1, 9, 16, or 23 with 10(7) cfu/ mL of Salmonella Typhimurium (1769NR) and killed 7 d later. Control groups were maintained untreated and remained unchallenged (negative control), or were challenged with Salmonella Typhimurium (1769NR; positive control), as described above. Cecum, liver, and spleen samples were examined for the presence of Salmonella, whereas serum and intestinal fluid samples were assayed for total antibody (IgG and IgA) concentrations. Data were analyzed by 1-way ANOVA, and means were compared using Duncan's multiple range test. In comparison with other treatments, those involving CE product and beta-glucan, with or without probiotic during the first week, resulted in a superior inhibition of cecal colonization and organ invasion by Salmonella and also offered a higher level of protection (P < 0.05). During the second week, treatments containing experimental dietary probiotic and beta-glucan, with or without CE product, resulted in an inhibition of liver invasion (P < 0.05). The IgA levels were significantly higher (P < 0.05) in intestinal fluid compared with serum, whereas IgG had low levels. The results in the first and third week indicate that combination treatments involving CE product, probiotic, and beta-glucan are a more effective control of Salmonella colonization than the corresponding individual preparations.

Orchitis in roosters with reduced fertility associated with avian infectious bronchitis virus and avian metapneumovirus infections.

The pathogenesis of infection involving both infectious bronchitis virus (IBV) and avian metapneumovirus (aMPV) causes reproductive damage in hens after viral replication in the epithelium of the oviduct, resulting in loss of cilia and degeneration and necrosis of the epithelial and glandular cells. Although IBV has been indicated as a possible cause of the formation of calcium stones in the epididymus of roosters, a definitive association has not been confirmed. This report describes the detection of IBV and aMPV in the testes of roosters from a Brazilian poultry broiler breeder's flock with epididymal stones and low fertility. Samples of testis, trachea, and lungs from breeder males aged 57 wk were positive for IBV by reverse transcriptase-polymerase chain reaction (RT-PCR), and virus isolation and testis samples were also positive for aMPV by RT-PCR. The inoculation of testis samples into embryonated chicken eggs via the allantoic cavity resulted in curled, hemorrhagic, and stunted embryos typical of IBV infection. The allantoic fluid was positive by RT-PCR aimed to amplify the region coding for the S1 subunit of the IBV S gene, but it was not positive for aMPV. Sequence analysis of the amplified fragment revealed a close relationship with European IBV genotype D274, previously unreported in Brazil. These results indicate that IBV and perhaps aMPV are likely to have played a role in the pathogenesis of the testicular disease described and should be regarded as factors that can influence male fertility disease in chickens.

Molecular characterization of infectious bronchitis virus strains isolated from the enteric contents of Brazilian laying hens and broilers.

Infectious bronchitis virus (IBV) is the causative agent of avian infectious bronchitis, which is characterized by respiratory, reproductive, and renal signs. However, the role of IBV as an enteric pathogen in still controversial. In Brazil, antigenic groups of IBV divergent from the Massachusetts serotype used for vaccination schedules in that country have already been demonstrated. The present study aimed to assess the different genotypes of IBV in Brazilian commercial poultry flocks by partial sequencing of the S1 amino-terminus coding region using enteric contents as samples and examine their relationship with the vaccine serotype currently in use. Samples of enteric contents were taken as pools of five birds from each of 18 poultry farms (17 broiler and one laying farm) from five Brazilian states between 2002 and 2006. Birds were presenting watery diarrhea and poor general condition but were without respiratory, renal, or reproductive signs. Conventional antibacterial and anticoccidial therapies were unsuccessful and, furthermore, all samples proved negative for rotavirus, reovirus, and astrovirus. Eleven IBV samples were isolated in embryonated eggs and resulted in S1 sequences. Phylogenetic analysis showed that these segregated into an exclusive cluster, close to serotype D274, but distant from Massachusetts. Mean amino acid identity amongst these Brazilian strains was 94.07%; amongst these and serotypes D274, 4/91, and Massachusetts, mean amino acid identity was 77.17%, 69.94%, and 68.93%, respectively. In conclusion, the presence of genotype variant strains of IBV in Brazilian poultry flocks has been demonstrated and might be the reason for the unsuccessful control of IBV in Brazil. Furthermore, these results also strengthen the implications of IBV in enteric diseases of poultry.

Histopathological and ultrastructural characteristics of myeloid leukosis in broiler chicken

An ultrastructural and histological study was performed to determine the degree of differentiation of the neoplastic cells. The histological study revealed neoplastic cells with pleomorphism, oval nuclei, prominent nucleoli, irregularly distributed chromatin, atypical mitotic figures and moderate amount of cytoplasm containing spherical eosinophilic granulations, typical features of the myeloid lineage. Ultrastructurally, there were cells with an electron-dense, oval and voluminous nucleus, with predominant euchromatin and cytoplasm containing many spherical, electron-dense and homogeneous granules, indicative of myelocytes with differentiation to eosinophils. Type-C viral particles were also seen in the intercellular space of renal tubules and inside the intracytoplasmic vesicles of immature myelocytes in the bone marrow and ovary. PCR was positive to ALV-J.

Caracterizaram-se a linhagem e o grau de diferenciação das células neoplásicas no estudo histopatológico e ultraestrutural da leucose mielóide. Histologicamente as células neoplásicas apresentaram pleomorfismo, núcleos ovais, nucléolos proeminentes, cromatina distribuída de maneira irregular, figuras de mitose atípicas e moderada quantidade de citoplasma contendo granulações eosinofílicas esféricas. Essas características indicam a linhagem mielóide. Ultraestruturalmente evidenciaram-se células com núcleo oval, volumoso, eletrodenso, com predomínio de eucromatina e citoplasma com numerosos grânulos esféricos, eletrodensos e homogêneos, indicando mielócitos com diferenciação para eosinófilos. Constatou-se também a presença de partículas virais tipo-C no espaço intercelular dos túbulos renais, no interior de vesículas intracitoplasmáticas dos mielócitos imaturos presentes na medula óssea e ovário, e PCR positivo para ALV-J.

Isolamento e identificação de Bacillus spp de leite UHT: detecção de toxina / Isolation and identification of Bacillus Spp of milk UHT: detection of toxin

O leite produzido a ultra alta temperatura, denominado UHT, é o leite de maior aceitação no mercado consumidor brasileiro. Neste estudo, determinou-se o número de microorganismos mesófilos aeróbios estritos e facultativos viáveis em 65 amostras de leite UHT, procedente de indústrias sob Inspeção Federal no Estado de São Paulo, coletadas durante 2002 e primeiro semestre de 2003. Observou-se que sete amostras (10,76 por cento) estavam fora dos padrões. As produções relativas a duas amostras foram inutilizadas pelo controle de qualidade das empresas, enquanto as demais (7,69 por cento) foram para o mercado consumidor, sendo estas provenientes de duas indústrias processadoras. Analisou-se a presença de Bacillus spp, assim como os eventuais esporos sobreviventes ao processamento, foram isoladas oito cepas de Bacillus spp. Utilizou-se também três (3) cepas de Bacillus spp isoladas pelo Instituto Adolfo Lutz, da cidade de São Paulo, de leite UHT alvo de reclamações de consumidores. Após a identificação morfológica, bioquímica e genética de culturas do Bacillus spp, estudou-se a produção de toxinas por estas amostras, através de inoculação de sobrenadante de cultura estéril em alça ileal ligada de coelho, teste de Dean e em células Vero, Hep2 e fibroblasmo de embrião de galinha. A identificação através de espectroscopio infra-vermelha de Fourier (FT-IR) das amostras isoladas pelo Instituto Adolfo Lutz caracterizou Bacillus flexus, enquanto as amostras isoladas de leite procedente de indústrias apresentaram a presença de B. flexus e B. sporothermodurans (...)

A VP3/VP1 gene polymerase chain reaction assay for detection of chicken anemia virus in broiler samples

Desenvolveu-se uma reação em cadeia de polimerase (PCR) para amplificação do altamente conservado gene VP3 e da região 5 do gene VP1, para o diagnóstico do vírus da anemia das galinhas (CAV), diretamente em amostras de campo de órgãos de frangos de corte com suspeita clínica da doença. A comparação entre o PCR VP3/VP1 com isolamento viral in vivo indicou 100 de concordância dos resultados, com 13 amostras positivas e três negativas em ambos os testes. Órgãos de outros 24 lotes de frangos com lesões e história clínica compatível com CAV foram testados com o PCR VP3/VP1 e com um PCR de referência com primers conhecidos para o gene VP1. Dezenove amostras resultaram positivas e uma negativa em ambos os PCR e quatro foram positivas apenas no PCR VP3/VP1. Estes resultados indicam que o PCR VP3/VP1 é um teste de diagnóstico sensível e específico, aplicável como alternativa ao método caro e demorado de isolamento viral in vivo especialmente considerando-se amostras do CAV não adaptáveis a cultivos de células MSB-1.

Use of single-enzyme amplified fragment length polymorphism for typing Pasteurella multocida subsp. multocida isolates from pigs.

Single-enzyme amplified fragment length polymorphism (SE-AFLP) analyses were used to differentiate 97 isolates of porcine Pasteurella multocida subsp. multocida. The strains, isolated from animals with pneumonia, rhinitis, and septicemia, were classified as capsular types A, D, and F. SE-AFLP showed a discriminatory index of 0.87 and identified 18 different profiles.

Comparison of three commercial competitive-exclusion products for controlling Salmonella colonization of broilers in Brazil.

In this study, a new competitive-exclusion (CE) product, Mucosal Starter Culture (MSC), was compared with two other CE products (Aviguard and Avifree) commercially available in Brazil to evaluate their ability to protect newly hatched chicks against colonization by a strain of Salmonella Kedougou. This study was based on a previously published and recommended method for such products. Separate groups of the chicks were dosed orally with the respective treatment materials and challenged 24 h later, and their ceca were examined for Salmonella 5 days after challenge. Under the test conditions, only MSC and Aviguard gave statistically significant (P < 0.05) protection to the chicks, but the MSC treatment yielded the lowest mean level of cecal carriage and the smallest proportion of Salmonella-positive birds.

Fator necrosante citotóxico em Escherichia coli isolada de mastite clínica bovina / Cytotoxic necrotizing factor in Escherichia coli strain isolated from clinical bovine mastitis

This report describes the production of cytotoxic necrotizing factor (CNF) by an Escherichia coli strain isolated from clinical bovine mastitis with clinical signs of toxemia The animal had hemorrhages and necrosis of the mammary glands, and died within 24 hours after the onset of clinical signs. In addition to CNF identification, alpha-haemolysin and siderophores production were also characterized in this strain. This report reinforce the association of CNF and alpha-haemolysin production in E. coli virulence associated with clinical cases of severe bovine mastitis