The aim of this study was to investigate the prevalence of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) strains and to identify the stx gene types in wild captive and companion birds. In total,657 E. coli isolates from 219 birds belonging to 38 different species were investigated for the presence of STEC and EPEC strains. It was shown that five birds (2.28%) carried strains positive for one or more of the virulence factors investigated. The results indicated that 1.8% (n=4) and 0.45% (n=1) of the birds carried STEC and EPEC strains, respectively. All STEC strains harbored the stx2f and eae genes and this finding reveals the role of other birds, in addition to pigeons, as reservoirs of STEC. The only EPEC strain in this study was isolated from a Myna. Based on our knowledge, this is the first report of Stx2f-producing STEC in Geese, Duck and Lesser kestrel. In conclusion, the results indicate a low frequency of STEC carriage in wild and companion birds, and point out the need of additionally screening for the presence of stx2f in all the eae-harboring strains from birds.

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This study aimed to evaluate prevalence, characteristics, genotypic diversity and antibacterial susceptibility of Escherichia coli encoding Shiga toxin 2f in domestic pigeons in different provinces of Iran. A total of 117 faecal samples were collected from pigeons and were subjected to molecular detection of stx2f. In total, 20, 25·8, 21·4 and 9% of pigeons from Tehran, Ferdows, Garmsar and Babol cities carried stx2f+ isolates, respectively. Of the 460 E. coli isolates examined, 43 were stx2f+ and most also carried eae (95·3%) and astA (97·7%) genes. Some of the stx2f+ isolates harboured cnf (9·3%), but all were negative for stx1, stx2 (other subtypes) and ehly. Most Strains (90%) were assigned to B1 phylogroup and possessed Intimin-β. Fingerprinting of the stx2f+ isolates using either enterobacterial repetitive intergenic consensus sequences (ERIC) or random amplified polymorphic DNA (RAPD)-polymerase chain reaction revealed seven distinct profiles by each method, with one prevailing (65·1 and 46·5%, respectively). By the combination of methods, 10 profiles were recognized. Ten isolates from different profiles were shown to belong to O20, O78 and O115 serogroups, and eight were 100% identical in the stx2f gene sequence. The strains were consistently resistant to amoxicillin and lincospectin and commonly resistant to tetracycline (88·4%) and doxycycline (74·4%). Overall, the results indicate a limited degree of genetic diversity in stx2f-harbouring E. coli from pigeons. Significance and impact of the study: Carriage of stx2f gene tends to be underreported in pigeon Escherichia coli isolates because most routine genetic and phenotypic tests cannot efficiently target this gene or detect the toxin. Nevertheless, pigeons frequently carry E. coli strains that are stx2f-positive, and this situation is not limited to any distinct geographical area. The current results suggest that genetic background of stx2f-encoding E. coli is distinct from most Shiga toxin-producing E. coli strains. However, the factors that contribute to host preferences and pathogenicity remain unclear. These findings have public health significance that should be addressed in future research.

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Poultry salmonellosis, one of the most prevalent diseases and major source of food-borne infections to humans due to consumption of poultry products is worldwide in distribution. The aim of this study was to investigate the incidence of salmonellosis in ostriches by culture and PCR , determination of antibiotic resistance pattern of the isolates and the infected ostriches antibody level. 87 fecal samples from one industrial ostrich farm with clinical signs of diarrhea, weight loss, mortality and reduced hatchability were collected and evaluated for presence of the Salmonella. Salmonella was isolated according to standard culture and biochemical tests. The Salmonella positive samples were serotyped with O and H antisera based on slide and tube agglutination tests. PCR was done for detection of serovars Infantis and Enteritidis. Then the antibiotic resistance against 14 antimicrobial agents were tested. The antibody level of the infected ostriches were measured by WIDAL agglutination test. Results indicated 9.1% (8 of 87) of ostriches were positive for Salmonella. Serotyping results showed 3 samples were serovar Infantis and 5 samples were serovar Enteritidis and PCR confirmed the serotyping results. All 8 samples were resistant to tetracyclin and ampicillin but sensitive to other antibiotics including ciprofloxacin, kanamycin, sultrim, cephalothin, norfloxacin, chloramphenicol, flumequine, nitrofurantoin, coamoxiclav, gentamicin, enrofloxacin and cefotaxime The results of WIDAL agglutination test indicated that all ostriches were negative except 8 Salmonella positive ostriches with the titres 1/80 to 1/360 for the O and 1/80 to 1/640 for the H antigens. To our knowledge this is the first study which reports the peresence of Salmonella Infantis in ostriches in Iran and more studies should be done to investigate this pathogen in ostriches herds of Iran.

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Subtilase is a potent cytotoxin that was first described in O113:H21 strain in Australia as a plasmid- encoded cytotoxin (subAB1). Subsequently, chromosomal variants including subAB2-1, subAB2-2, and subAB2-3 were described. In the present study a collection of 101 STECs isolated from various sources in Iran (2009-2016) were analyzed for the detection of different genes encoding the subtilase variants, plasmidic and chromosomal virulence genes, together with the phylogroup and serogroups. Overall, 57 isolates (56.4%) carried at least one variant of subAB. Most strains from small ruminants including 93% of sheep and 96% of caprine isolates carried at least one chromosomally encoded variant (subAB-2). In contrast, 12 cattle isolates (24%) only harbored the plasmid encoded variant (subAB1). STEC strains from other sources including deer, pony and humans were positive for subAB-2-1 and/or subAb2-2. Concerning the virulence markers, some strains showed an association with hosts the bacteria were isolated from. In particular, tia was associated with sheep, goats and pony isolates and astA gene was present in deer, pony and goats and terD was only found in deer and pony isolates. Only cattle STEC carried espP and epeA, the important markers of pO113 plasmid. Some genes were widespread among strain of various sources like ehly, iha and lpfO113 and some genes were not detected such as efa1, toxB and katP. Most strains belonged to phylogenetic group B1 (89.47%), but five strains from cattle, deer, pony and a goat were assigned to A phylogroup. Most cattle strains belonged to O113, while O5 was just detected in ovine isolates, and O128 and O113 were present in caprine strains. In conclusion, the present study reveals the presence of potentially pathogenic genotypes among LEE-negative isolates and some host specificity related to subtilase variants and other virulence markers that may aid in source tracking of STEC during outbreaks.