BACKGROUND: COLIBACILLOSIS is one of the most prevalent diseases in the world that causes multimillion-dollar annual losses.OBJECTIVES: In order to evaluate molecular epidemiology of some virulence associated factors in Escherichia coli, isolated from poultry, the presence of iut A, iss, hly F, omp T, iro N, afa, sfa (S)and pap G (II) were investigated by multiplex PCR assay.METHODS: Two hundred thirty four Escherichia coli isolated from AVIAN COLIBACILLOSIS (APEC) and fifty four fecal E. coli isolates from the feces of apparently healthy birds (AFEC) were investigated for presence of some virulence associated genes by two panel of multiplex PCR. Statistical analysis was performed using X2 test. the p-value was £0.05.RESULTS: Among 234 E. coli strains associated with COLIBACILLOSIS and 54 AFEC strains, 85% of isolates were positive for at least one of the virulence gene. The three most prevalent genes in E. coli isolated from COLIBACILLOSIS were hly F (77.3%), omp T (73%) and iss (68.2%). Iut A, iro Nand pap G (II) were detected in 157 (67.4%), 152 (65.2%) and 41(17.6%) respectively. None of isolates harbored sfa (s) and afa genes. Several combination patterns of virulence genes were detected. Combination of hly F, omp T (70.8%) was the most prevalent pattern.CONCLUSIONS: the prevalence of iss, hly F, omp T, iro N genes in APEC isolates was significantly more than AFEC strains and probably these genes play an important role in the pathogenesis of APEC strains.

COLIBACILLOSIS is known as a fatal bacterial disease resulting in a high level of commercial loss worldwide. This study amid to elucidate the sequence, genetic characteristics, and phylogeny of the bor gene in Escherichia coli (E. coli) strain c1378 (O78: K80) isolated from AVIAN COLIBACILLOSIS in Iran and develop a rapid and optimal polymerase chain reaction (PCR) molecular-based technique with specific primers to detect this gene in E. coli. A virulent AVIAN E. coli (i. e., laboratory designation E. coli strain c1378) isolated from a chicken with systemic COLIBACILLOSIS from a broiler farm in Tehran, Iran, in 2004 was used as a source of the bor gene. After DNA extraction, PCR method was used to amplify the bor gene. A 658 bp fragment of the bor gene was amplified, sequenced, blasted, and phylogenetically studied. The most similar sequences to the bor gene in E. coli strain c1378 were E. coli APEC O78, Enterobacteria phage HK630, and Escherichia coli BW2952, respectively. There was a high similarity between the bor gene in E. coli bacteria with their phage and plasmid. Moreover, a high similarity was observed between the bor and iss genes (approximately 92%) showing that they were homologous genes. In addition, the similarity analysis of different bacterial species, as well as their plasmid and bacteriophage, to the bor gene indicated that the highest similarity to O78: K80 was related to Paracoccidioides brasiliensis, Bacillus thuringiensis CT43 plasmid pBMB0558, and Salmonella enterica subsp. enterica serovar Kentucky strain CVM29188 plasmid, respectively. Altogether, the results of the present study confirmed the presence of the bor gene in the studied isolates and clarified its sequence, phylogenetic relationship, and similarities of E. coli strain c1378 (O78: K80) isolated from AVIAN COLIBACILLOSIS.

Aim and Background: Extra-intestinal strains of the pathogenic Escherichia coli APEC are one of the most serious threats to the poultry industry in the world and in Iran, with extensive economic losses due to the high mortality rate in broiler herds. Molecular studies and determination of the frequency of virulence factors of APEC strains provide very useful information for designing and manufacturing vaccines against diseases caused by these strains. The aim of this study was to molecular detection of virulence genes iss and fimC in Escherichia coli Isolates from Poultry with COLIBACILLOSIS in Ilam City. Material and methods: This descriptive cross-sectional study was performed on one hundred and fifty APEC isolates collected from general cases of poultry COLIBACILLOSIS in the year 1399. First, isolates were identified using selective and differential culture media and standard biochemical tests. PCR test was used to determine the presence of virulence genes iss and fimC among Escherichia coli isolates using a specific primer. Results: Results of PCR test on one hundred and fifty APEC isolates obtained from COLIBACILLOSIS cases using specific primers to detect the genes encoding fimbriae type 1 fimC and the gene Increased serum survival iss showed that 139 isolates (92. 66%) had fimC gene. Also, the results showed that among the total isolates, 126 isolates (84%) have the increased serum survival iss gene. Conclusion: The results of this study indicate the high presence of virulence genes iss and fimC in Escherichia coli isolates isolated from AVIAN COLIBACILLOSIS in the study area. Detection of these genes can be used as diagnostic markers of pathogenic Escherichia coli in poultry.

Background: The emergence and propagation of different phylogenetic groups of antimicrobial-resistant E. coli have become a worldwide health concern in human and veterinary medicine. Therefore, the evaluation of the phylogenetic distribution of antibiotic-resistant E. coli is important for therapeutic and economic purposes. The aims of this study were to determine phylogenetic groups and patterns of antibiotic resistance of E. coli strains isolated from human urinary tract infection and AVIAN COLIBACILLOSIS. Methods: A total of 50 E. coli isolates (25 from human urinary tract infection and 25 from AVIAN COLIBACILLOSIS) were characterized by culture and assigned as different phylogenetic groups (A, B1, B2, and D) by triplex PCR assay. Kirby-Bauer disk diffusion method was used to assess the susceptibility of all isolates to ten antibiotics. Results: Results showed that the majority of the human and poultry isolates belonged to phylogenetic groups A and B2 and phylogenetic group B1 of the AVIAN pathogenic strain isolates were the most drug-resistant isolates. Most of the isolates were resistant to at least five antibiotics, and multiple drug resistance was observed in 98% of E. coli isolates. A high degree of resistance was seen against penicillin and erythromycin. Conclusion: According to the results of this study, multidrug-resistance among isolates and high relation between phylogenetic groups and resistance in both human and poultry isolates were observed.

Background: AVIAN pathogenic Escherichia coli (APEC) causes economic losses in the chicken industry worldwide. Objective: In this study, virulence-associated gene profiles of APEC isolates were investigated by polymerase chain reaction (PCR). Materials and Methods: A total of 60 Escherichia coli isolates were collected from 60 COLIBACILLOSIS cases from 30 broiler poultry farms in Alborz, Tehran, and Golestan provinces, Iran. After identification by biochemical tests, DNA was extracted by boiling method and 5 virulence-associated genes including: iutA, hlyF, iroN, ompT, and iss were detected by 2 multiplex PCR protocols. Results: Of the 60 APEC isolates, 26 (43. 3%) isolates had at least three virulence genes from which 12 (20%) isolates were positive for all 5 virulence genes, whereas 34 (56. 6%) carried no investigated virulence genes. Presence of iutA, hlyF, iroN, ompT, and iss genes in the APEC isolates were 17 (28. 3%), 17 (28. 3%), 24 (40%), 26 (43. 3%), and 23 (38. 3%), respectively. Conclusion: According to the results, four different virulence-associated gene profiles were seen in isolates, from which profile 1 with 12 (20%) isolates was predominant. These findings were in agreement with the previous reports.

Background: AVIAN pathogenic Escherichia coli (APEC) strains have been associated with various disease conditions in AVIAN species due to virulence attributes associated with the organism. Aims: This study was carried out to determine the in vitro pathogenic characteristics and virulence encoding genes found in E. coli strains associated with COLIBACILLOSIS in chickens. Methods: Fifty-two stock cultures of E. coli strains isolated from chickens diagnosed of COLIBACILLOSIS were tested for their ability to produce haemolysis on blood agar and take up Congo red dye. Molecular characterization was carried out by polymerase chain reaction (PCR) amplification of virulence encoding genes associated with APEC. Results: Eleven (22%) and 41 (71%) were positive for haemolysis on 5% sheep red blood agar and Congo red agar, respectively. Nine virulence-associated genes were detected as follows: FimH (96%), csgA (52%), iss (48%), iut (33%), tsh (21%), cva (15%), kpsII (10%), pap (2%), and felA (2%). Conclusion: The APEC strains exhibited virulence properties and harbored virulence encoding genes which could be a threat to the poultry population and public health. The putative virulence genes were diverse and different in almost all isolate implying that pathogenesis was multi-factorial and the infection was multi-faceted which could be a source of concern in the detection and control of APEC infections.