Molecular characterization of avian adenoviruses in Iranian broiler flocks

This study was conducted to molecularly detect avian adenoviruses in broiler flocks showing liver lesions and respiratory syndrome in northeast Iran. In total, 60 tissue samples were collected from broiler farms with liver lesions, respiratory syndrome and also from clinically healthy flocks. Six samples were positive; however, three samples were selected for molecular studies. PCR products were sequenced to confirm the identity of avian adenoviruse. Based on the sequence analysis of the L1 region of the hexon gene, the NRB/FAV/4 should be classified as FAdV 8b strain and two other isolates - NRB/FAV/1 and NRB/FAV/5 - classified in cluster of the FAdV 2 and 11. As far as we know, this preliminary investigation is the only documented study to confirm the presence of avian adenoviruses in broiler flocks in Iran

Isolation and identification of Helicobacter pullorum from caecal content of broiler chickens in Mashhad, Iran

The presence of Helicobacter pullorum in intestinal tract of broiler chickens may be a potential risk for human health. In this study, a total of 100 caecal samples of broilers carcasses from 20 flocks at a poultry abattoir in Mashhad suburb were tested for the presence of H. pullorum using modified conventional culture method by combination of culturing on Brucella sheep blood agar and a filtering technique. Suspected colonies were determined as H. pullorum using polymerase chain reaction [PCR] by amplifying a 447 bp fragment of the 16SrRNA gene of this bacteria. 41% of caecal content samples and samples from 12 broiler flocks [60%] were determined as positive for the presence of H. pullorum. This is the first report of H. pullorum in Iranian poultry flocks. The results showed high prevalence of this bacterium in broiler chickens in this area of Iran. It seems using combination of conventional culture method and PCR assay based on amplification from conserved genes allows reliable detection and identification of H. pullorum

Isolation and identification of Campylobacter jejuni from poultry carcasses using conventional culture methods and multiplex PCR assay

Campylobacter jejuni is a major cause of food-borne diarrhea in many countries. Poultry and poultry products are known as important sources of human campylobacteriosis. In this study, conventional culture and multiplex PCR methods were compared for the detection of C. jejuni isolated from poultry carcasses. A total of 100 samples, representing 20 broiler flocks, were collected from poultry carcasses after the evisceration stage in the processing line at a commercial broiler slaughtering facility in Mashhad, Iran. In the conventional culture method, samples were processed by enrichment followed by selective plating, and then suspected colonies were isolated on sheep blood agar and tested for morphology, motility, Gram staining, biochemical properties and hippurate hydrolysis activity. For the identification of the Campylobacter genus and its jejuni serovar by molecular methods, a multiplex PCR assay [m-PCR] with two sets of specific primers was used. In the hippurate hydrolysis test of suspected colonies, 76% of the samples were determined as positive, while in the m-PCR assay 28% of cultures harvested were identified as C. jejuni. Two percent of hippurate hydrolyze negative colonies were found positive in the m-PCR test. It appears that the conventional method, based on the hippurate hydrolysis test for detection of C. jejuni, is a less reliable test. The use of the m-PCR method, based on amplification from conserved genes, allows reliable detection and identification of C. jejuni

Identification of shiga toxin producing escherichia coli O157:H7 in raw cow milk samples from dairy farms in Mashhad using multiplex PCR assay

In this study 130 bulk tank milk samples which were delivered to the Pegah Pasturisation Factory in Mashhad were collected randomly during the summer months. Samples were firstly enriched in modified trypticase soy broth containing novobiocin, followed by plating onto sorbitol MacConkey agar supplemented with cefixine and potassium tellurite for isolation of Escherichia coli O157:H7. Consequently the suspected non-sorbitol fermenting [NSF] colonies were confirmed by biochemical tests as Escherichia coli and then were used for multiplex-PCR assay, using primers specific for O157 and H7 antigens genes and then primers specific for stxl and stx2 genes. NSF Escherichia coli colonies were recovered from 8 samples, and in multiplex-PCR assay one sample [0.77%] was confirmed as Escherichia coli O157:H7. The second multiplex PCR assay showed that the isolate was harboring the stx2 gene. The PCR assay used in this study may be a possible alternative to immunological assays which detect somatic and flagellar antigens. Besides, this procedure determines the potential of isolates for toxin production

Psittacine beak and feather disease in Iran, molecular and histopathologic detection

Psittacine beak and feather disease [PBFD] is a major viral disease in wild and captive psittaciformes all around the world. The disease was suspected in a 7 years old lesser sulphur-crested cockatoos [Cacatua sulphured] with a minor feather loss at the back of neck and head. The bird was comprehensively examined by macroscopic pathology, histopathology and polymerase chain reaction [PCR]. Marked intracellular edema of the keratinocytes and necrosis were evident in histopathological observation of dystrophic feather follicles. Numerous macrophages with cytoplasmic inclusions [botryoid] and Prevasculitis were also present in the dermis. Histopathologically, the feather lesions and inclusions were typical of PBFD. The presence of psittacine beak and feather disease virus [BFDV] DNA was confirmed by PCR. This is the first documented report of the occurrence of the PBFD in Iran