Specific Roles of the iroBCDEN Genes in Virulence of an Avian Pathogenic Escherichia coli O78 Strain and in Production of Salmochelins

ABSTRACT Avian pathogenic Escherichia coli (APEC) strains are a subset of extraintestinal pathogenic E. coli (ExPEC) strains associated with respiratory infections and septicemia in poultry. The iroBCDEN genes encode the salmochelin siderophore system present in Salmonella enterica and some ExPEC strains. Roles of the iro genes for virulence in chickens and production of salmochelins were assessed by introducing plasmids carrying different combinations of iro genes into an attenuated salmochelin- and aerobactin-negative mutant of O78 strain χ7122. Complementation with the iroBCDEN genes resulted in a regaining of virulence, whereas the absence of iroC, iroDE, or iroN abrogated restoration of virulence. The iroE gene was not required for virulence, since introduction of iroBCDN restored the capacity to cause lesions and colonize extraintestinal tissues. Prevalence studies indicated that iro sequences were associated with virulent APEC strains. Liquid chromatography-mass spectrometry analysis of supernatants of APEC χ7122 and the complemented mutants indicated that (i) for χ7122, salmochelins comprised 14 to 27% of the siderophores present in iron-limited medium or infected tissues; (ii) complementation of the mutant with the iro locus increased levels of glucosylated dimers (S1 and S5) and monomer (SX) compared to APEC strain χ7122; (iii) the iroDE genes were important for generation of S1, S5, and SX; (iv) iroC was required for export of salmochelin trimers and dimers; and (v) iroB was required for generation of salmochelins. Overall, efficient glucosylation (IroB), transport (IroC and IroN), and processing (IroD and IroE) of salmochelins are required for APEC virulence, although IroE appears to serve an ancillary role.

Download Full-text

Complete DNA Sequence of a ColBM Plasmid from Avian Pathogenic Escherichia coli Suggests that It Evolved from Closely Related ColV Virulence Plasmids

Journal of Bacteriology ◽

10.1128/jb.00204-06 ◽

2006 ◽

Vol 188 (16) ◽

pp. 5975-5983 ◽

Cited By ~ 112

Author(s):

Timothy J. Johnson ◽

Sara J. Johnson ◽

Lisa K. Nolan

Keyword(s):

Escherichia Coli ◽

Southern Blotting ◽

Virulence Genes ◽

Complete Sequence ◽

Economic Losses ◽

Avian Pathogenic Escherichia Coli ◽

Prevalence Studies ◽

E Coli ◽

Virulence Plasmids ◽

Pathogenic Escherichia Coli

ABSTRACT Avian pathogenic Escherichia coli (APEC), an extraintestinal pathogenic E. coli causing colibacillosis in birds, is responsible for significant economic losses for the poultry industry. Recently, we reported that the APEC pathotype was characterized by possession of a set of genes contained within a 94-kb cluster linked to a ColV plasmid, pAPEC-O2-ColV. These included sitABCD, genes of the aerobactin operon, hlyF, iss, genes of the salmochelin operon, and the 5′ end of cvaB of the ColV operon. However, the results of gene prevalence studies performed among APEC isolates revealed that these traits were not always linked to ColV plasmids. Here, we present the complete sequence of a 174-kb plasmid, pAPEC-O1-ColBM, which contains a putative virulence cluster similar to that of pAPEC-O2-ColV. These two F-type plasmids share remarkable similarity, except that they encode the production of different colicins; pAPEC-O2-ColV contains an intact ColV operon, and pAPEC-O1-ColBM encodes the colicins B and M. Interestingly, remnants of the ColV operon exist in pAPEC-O1-ColBM, hinting that ColBM-type plasmids may have evolved from ColV plasmids. Among APEC isolates, the prevalence of ColBM sequences helps account for the previously observed differences in prevalence between genes of the “conserved” portion of the putative virulence cluster of pAPEC-O2-ColV and those genes within its “variable” portion. These results, in conjunction with Southern blotting and probing of representative ColBM-positive strains, indicate that this “conserved” cluster of putative virulence genes is primarily linked to F-type virulence plasmids among the APEC isolates studied.

Download Full-text

Avian Pathogenic Escherichia coli (APEC): An Overview of Virulence and Pathogenesis Factors, Zoonotic Potential, and Control Strategies

Pathogens ◽

10.3390/pathogens10040467 ◽

2021 ◽

Vol 10 (4) ◽

pp. 467

Author(s):

Dipak Kathayat ◽

Dhanashree Lokesh ◽

Sochina Ranjit ◽

Gireesh Rajashekara

Keyword(s):

Escherichia Coli ◽

Current Status ◽

Neonatal Meningitis ◽

Clear Understanding ◽

Zoonotic Potential ◽

Secretion Systems ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli ◽

Tract Infections

Avian pathogenic Escherichia coli (APEC) causes colibacillosis in avian species, and recent reports have suggested APEC as a potential foodborne zoonotic pathogen. Herein, we discuss the virulence and pathogenesis factors of APEC, review the zoonotic potential, provide the current status of antibiotic resistance and progress in vaccine development, and summarize the alternative control measures being investigated. In addition to the known virulence factors, several other factors including quorum sensing system, secretion systems, two-component systems, transcriptional regulators, and genes associated with metabolism also contribute to APEC pathogenesis. The clear understanding of these factors will help in developing new effective treatments. The APEC isolates (particularly belonging to ST95 and ST131 or O1, O2, and O18) have genetic similarities and commonalities in virulence genes with human uropathogenic E. coli (UPEC) and neonatal meningitis E. coli (NMEC) and abilities to cause urinary tract infections and meningitis in humans. Therefore, the zoonotic potential of APEC cannot be undervalued. APEC resistance to almost all classes of antibiotics, including carbapenems, has been already reported. There is a need for an effective APEC vaccine that can provide protection against diverse APEC serotypes. Alternative therapies, especially the virulence inhibitors, can provide a novel solution with less likelihood of developing resistance.

Download Full-text

Resistência antimicrobiana e perfil plasmidial de Escherichia coli isolada de frangos de corte e poedeiras comerciais no Estado de Pernambuco

Pesquisa Veterinária Brasileira ◽

10.1590/s0100-736x2012000500008 ◽

2012 ◽

Vol 32 (5) ◽

pp. 405-410 ◽

Cited By ~ 7

Author(s):

Mércia R. Barros ◽

Wanderley D, da Silveira ◽

Janete M. de Araújo ◽

Elizianne P. Costa ◽

Andrea Alice da F. Oliveira ◽

...

Keyword(s):

Escherichia Coli ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli

Embora existam linhagens de Escherichia coli não patogênicas para aves, muitas outras possuem a capacidade de causar sérios danos à saúde das mesmas, sendo capazes de ocasionar diferentes tipos de processos infecciosos. As linhagens patogênicas são denominadas Avian Pathogenic Escherichia coli (APEC), possuindo genes relacionados ao processo de patogênese em epissomos (plasmídios) ou no cromossomo. A presença de plasmídios, contendo genes de resistência a antibióticos em linhagens aviárias, patogênicas ou não, indicam a possibilidade de transferência gênica lateral entre diferentes tipos de linhagens facilitando também a transferência de genes de patogenicidade ou virulência. Objetivou-se com este estudo avaliar o perfil de sensibilidade a antibióticos (13) de diferentes amostras (35) de E. coli isoladas de aves comerciais do Estado de Pernambuco apresentando, ou não, sinais clínicos de processos infecciosos e correlacionar esta resistência com a presença de plasmídios. Os testes utilizados demonstraram que 94,28% dos isolados foram resistentes a três ou mais antibióticos, com a lincomicina apresentando o maior percentual de resistência (100%). Na Concentração Inibitória Mínima (CIM) observou-se multirresistência a vários antimicrobianos. A presença de plasmídios foi detecada em 80,0% (28/35) dos isolados, com 16 isolados apresentando plasmídios com peso molecular aproximado de 88 MDa. Também foi verificada a presença de linhagens apresentando plasmídios de vários tamanhos. Concluiu-se que isolados de E. coli resistentes a antimicrobianos utilizados na avicultura estão presentes no Estado de Pernambuco, tanto em frangos de corte quanto em poedeiras comerciais. A presença de plasmídios detectados na maioria dos isolados pode estar associada à resistência aos antimicrobianos e sugere a presença de possíveis genes relacionados à patogenicidade. Monitorar a resistência a antibióticos em bactérias isoladas de animais torna-se um fator determinante para eleição e êxito do tratamento, bem como a possibilidade de eliminação daquelas que possuem plasmídios para se evitar a transferência de genes relacionados à patogenicidade.

Download Full-text

Virulence gene profiles of avian pathogenic Escherichia coli isolated from chickens with colibacillosis in Bulawayo, Zimbabwe

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v82i1.850 ◽

2015 ◽

Vol 82 (1) ◽

Cited By ~ 10

Author(s):

Joshua Mbanga ◽

Yvonne O. Nyararai

Keyword(s):

Escherichia Coli ◽

Virulence Genes ◽

Virulence Gene ◽

Economic Losses ◽

Avian Pathogenic Escherichia Coli ◽

Pcr Assay ◽

E Coli ◽

Gene Profiles ◽

Pathogenic Escherichia Coli ◽

Polymerase Chain

Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC), is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR) assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%), fimH (33.3%) and hlyF (24.4%). The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.

Download Full-text

Transcription Regulator YgeK Affects the Virulence of Avian Pathogenic Escherichia coli

Animals ◽

10.3390/ani11113018 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3018

Author(s):

Jian Tu ◽

Dandan Fu ◽

Yi Gu ◽

Ying Shao ◽

Xiangjun Song ◽

...

Keyword(s):

Escherichia Coli ◽

Transcriptional Regulator ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli ◽

System 2 ◽

Important Regulator ◽

Alignment Analysis ◽

Responsible Pathogen

Avian pathogenic Escherichia coli (APEC) is the responsible pathogen for colibacillosis in poultry, and is a potential gene source for human extraintestinal pathogenic Escherichia coli. Escherichia coli type III secretion system 2 (ETT2) is widely distributed in human and animal ExPEC isolates, and is crucial for the virulence of ExPEC. Transcriptional regulator YgeK, located in the ETT2 gene cluster, was identified as an important regulator of gene expression in enterohemorrhagic E. coli (EHEC). However, the role of YgeK in APEC has not been reported. In this study, we performed amino acid alignment analysis of YgeK among different E. coli strains and generated ygeK mutant strain AE81ΔygeK from clinical APEC strain AE81. Flagellar formation, bacterial motility, serum sensitivity, adhesion, and virulence were all significantly reduced following the inactivation of YgeK in APEC. Then, we performed transcriptome sequencing to analyze the functional pathways involved in the biological processes. Results suggested that ETT2 transcriptional regulator YgeK plays a crucial role in APEC virulence. These findings thus contribute to our understanding of the function of the ETT2 cluster, and clarify the pathogenic mechanism of APEC.

Download Full-text

Virulence Characteristic of Avian Pathogenic Escherichia coli (APEC) Isolates

Jurnal Sain Veteriner ◽

10.22146/jsv.46494 ◽

2020 ◽

Vol 38 (1) ◽

pp. 61

Author(s):

Sruti Listra Adrenalin ◽

Lynda Nugrahaning Imanjati ◽

Ima Fauziah ◽

Vinsa Cantya Prakasita ◽

Sitarina Widyarini ◽

...

Keyword(s):

Escherichia Coli ◽

Respiratory Disease ◽

High Mortality ◽

Specific Pathogen Free ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli ◽

High Virulence ◽

Specific Pathogen ◽

Costs Of Treatment

Avian pathogenic Escherichia coli (APEC) is a cause of colibacillosis in poultry, one of the respiratory disease that causes serious problems in the poultry industry. The APEC can cause high mortality and culling, decreased production, and high costs of treatment. Manifestations of colibacillosis are airsacculitis, perihepatitis, and pericarditis. The APEC serotypes that are widely identified in the field are O1K1, O2K1, and O78K80. Embryo lethality assay (ELA) is a method for determine the virulence of APEC serotypes. The aim of this study was to determine the virulence characteristic of APEC isolates. Five APEC serotypes O1K1, O2K1, O78K80, O157H7, and unknown serotype were used for ELA method by inoculated E. coli into chorioallantoic of specific pathogen free 12-days old embryos. Each group of 10 embryos, inoculated E. coli dose of 100-500 CFU/ 0,1 ml. Candling was carried out for 6 days (18-days old embryo) to determined the mortality and pathological lesions. The percentage of embryo mortality post-inoculated with APEC O1K1, O2K1, unknown serotypes were 100% (10/10), O78K80 serotype was 90% (9/10), and O157H7 serotype was 70% (70%). Lesions of all embryos were cranial and extremity hemorrhage. In this study, E. coli isolates had high virulence.

Download Full-text

Classification of Avian Pathogenic Escherichia coli by a Novel Pathogenicity Index Based on an Animal Model

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.80888 ◽

2018 ◽

Vol 44 (1) ◽

pp. 6

Author(s):

Guilherme Fonseca de Souza ◽

Silvio Luís da Silveira Rocha ◽

Thales Quedi Furian ◽

Karen Apellanis Borges ◽

Felipe De Oliveira Salle ◽

...

Keyword(s):

Escherichia Coli ◽

Brain Heart Infusion ◽

Brain Heart Infusion Broth ◽

Bedding Material ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Death Time ◽

A Value ◽

Pathogenic Escherichia Coli

Background: Avian Pathogenic Escherichia coli is the main agent of colibacillosis, a systemic disease that causes considerable economic losses to the poultry industry. In vivo experiments are used to measure the ability of E. coli to be pathogenic. Generally, these experiments have proposed different criteria for results interpretation and did not take into account the death time. The aim of this study was to propose a new methodology for the classification of E. coli pathogenicity by the establishment of a pathogenicity index based in the lethality, death time and the ability of the strain to cause colibacillosis lesions in challenged animals.Materials, Methods & Results: A total of 293 isolates of E. coli were randomly selected to this study. The strains were isolated from cellulitis lesions, broiler bedding material or respiratory diseases and were previously confirmed through biochemical profile. The bacterial isolates were kept frozen at -20°C. The strains were retrieved from stocks and cultured in brain-heart infusion broth overnight at 37°C to obtain a final concentration of 109 UFC/mL. A total of 2940 one-dayold chicks from commercial breeding hens were randomly assigned to groups containing 10 animals and each group was subcutaneously inoculated in the abdominal region with 0.1 mL of the standard inoculum solution containing each of the strains. A control group of 10 broilers were inoculated with 0.1 mL of brain-heart infusion broth by the same route. The chicks were kept for seven days. They were observed at intervals of 6, 12 and 24 h post-inoculation during the first days. From the second day on, the chicks were observed at intervals of 12 h. According to the death time and to the scores of each lesion (aerosaculitis, pericarditis, perihepatitis, peritonitis and cellulitis), a formula to determine the Individual Pathogenicity Index was established. A value of 10 was established as the maximum pathogenicity rate for an inoculated bird. From this rate, 5 points corresponded to scores for gross lesions present at necropsy. For each lesion present, it represents 1 point. The remaining 5 points corresponded to the death time. To obtain the death time value, an index of 1, corresponding to the maximum value assigned to a death on the first day, was divided by the number of days that the birds were evaluated, resulting in a value of 0.1428, which corresponded to a survival bonus factor. It was possible to classify E. coli strains into four pathogenicity groups according to the pathogenicity index: high pathogenicity (pathogenicity index ranging from 7 to 10), intermediate pathogenicity (pathogenicity index ranging from 4 to 6.99), low pathogenicity (pathogenicity index ranging from 1 to 3.99) and apathogenic (pathogenicity index ranging from 0 to 0.99). The analysis of the strains according to their origin revealed that isolates from broiler bedding material presented a lower pathogenicity index.Discussion: It is possible that the source of isolation implies in different results, depending on the criteria adopted. This data reinforces the importance of use a more accurate mathematical model to represents the biological phenomenon. In the study, all avian pathogenic Escherichia coli strains were classified based on a pathogenicity index and the concept of the death time represents an interesting parameter to measure the ability of the strain to promote acute and septicemic manifestation. The use of a support method for poultry veterinary diagnostic accompanying the fluctuation of the bacteria pathogenicity inside the farms may indicate a rational use of antimicrobial in poultry industry.

Download Full-text

Characterization and antimicrobial resistance patterns of Escherichia coli isolated from feces of healthy broiler chickens

Arquivos do Instituto Biológico ◽

10.1590/1808-1657000392014 ◽

2016 ◽

Vol 83 (0) ◽

Cited By ~ 3

Author(s):

Ariel Eurides Stella ◽

Maria Cristina De Oliveira ◽

Vera Lúcia Dias da Silva Fontana ◽

Renato Paris Maluta ◽

Clarissa Araújo Borges ◽

...

Keyword(s):

Escherichia Coli ◽

Broiler Chickens ◽

Clinical Signs ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

The Past ◽

Pathogenic Escherichia Coli ◽

Resistance Patterns ◽

Resistant Strains ◽

Polymerase Chain

ABSTRACT: Avian pathogenic Escherichia coli (APEC) strains are isolated from lesions of poultry presenting colibacillosis, which is a disease that causes either systemic or localized clinical signs. Such strains share many characteristics with E. coli strains that cause extra-intestinal illness in humans. There is not a consensus on how to define the APEC pathotype with regard to the presence of virulence traits. On the other hand, in the past few years, five minimal predictors for APEC detection were proposed. The E. coli isolates in this work were tested through polymerase chain reaction (PCR) to the five proposed minimal predictors and cva C. The strains presenting them were categorized as potential APEC. The APEC and non-APEC categories showed high resistance (> 50%) to cephalotin, erythromycin, streptomycin, sulphametoxazol/trimethoprim, ampicillin, and amoxicillin. Potential APEC strains were significantly more resistant to cephalotin (p < 0.05) and neomcycin (p < 0.01) than non-APEC. These latter were significantly more resistant to tetracycline (p < 0.01) than the potential APEC strains. These results demonstrate that feces of poultry present E. coli strains with resistant features, showing or not the potential of causing colibacillosis in poultry. Because APEC and extra-intestinal illness in humans may be similar, these resistant strains are of interest to public health.

Download Full-text

Multidrug-Resistant Avian Pathogenic Escherichia coli Strains and Association of Their Virulence Genes in Bangladesh

Microorganisms ◽

10.3390/microorganisms8081135 ◽

2020 ◽

Vol 8 (8) ◽

pp. 1135

Author(s):

Otun Saha ◽

M. Nazmul Hoque ◽

Ovinu Kibria Islam ◽

Md. Mizanur Rahaman ◽

Munawar Sultana ◽

...

Keyword(s):

Escherichia Coli ◽

Virulence Genes ◽

Multidrug Resistant ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Molecular Approaches ◽

Clade B ◽

Pathogenic Escherichia Coli ◽

Resistance Patterns

The avian pathogenic Escherichia coli (APEC) strains are the chief etiology of colibacillosis worldwide. The present study investigated the circulating phylotypes, existence of virulence genes (VGs), and antimicrobial resistance (AMR) in 392 APEC isolates, obtained from 130 samples belonged to six farms using both phenotypic and PCR-based molecular approaches. Congo red binding (CRB) assay confirmed 174 APEC isolates which were segregated into ten, nine, and eight distinct genotypes by RAPD assay (discriminatory index, DI = 0.8707), BOX-PCR (DI = 0.8591) and ERIC-PCR (DI = 0.8371), respectively. The combination of three phylogenetic markers (chuA, yjaA and DNA fragment TspE4.C2) classified APEC isolates into B23 (37.36%), A1 (33.91%), D2 (11.49%), B22 (9.20%), and B1 (8.05%) phylotypes. Majority of the APEC isolates (75–100%) harbored VGs (ial, fimH, crl, papC, and cjrC). These VGs (papC and cjrC) and phylotypes (D2 and B2) of APEC had significant (p = 0.004) association with colibacillosis. Phylogenetic analysis showed two distinct clades (clade A and clade B) of APEC, where clade A had 98–100% similarity with E. coli APEC O78 and E. coli EHEC strains, and clade B had closest relationship with E. coli O169:H41 strain. Interestingly, phylogroups B2 and D2 were found in the APEC strains of both clades, while the strains from phylogroups A1 and B1 were found in clade A only. In this study, 81.71% of the isolates were biofilm formers, and possessed plasmids of varying ranges (1.0 to 54 kb). In vitro antibiogram profiling revealed that 100% isolates were resistant to ≥3 antibiotics, of which 61.96%, 55.24%, 53.85%, 51.16% and 45.58% isolates in phylotypes B1, D2, B22, B23, and A1, respectively, were resistant to these antimicrobials. The resistance patterns varied among different phylotypes, notably in phylotype B22, showing the highest resistance to ampicillin (90.91%), nalidixic acid (90.11%), tetracycline (83.72%), and nitrofurantoin (65.12%). Correspondence analysis also showed significant correlation among phylotypes with CRB (p = 0.008), biofilm formation (p = 0.02), drug resistance (p = 0.03), and VGs (p = 0.06). This report demonstrated that B2 and A1 phylotypes are dominantly circulating APEC phylotypes in Bangladesh; however, B2 and D2 are strongly associated with the pathogenicity. A high prevalence of antibiotic-resistant APEC strains from different phylotypes suggest the use of organic antimicrobial compounds, and/or metals, and the rotational use of antibiotics in poultry farms in Bangladesh.

Download Full-text

IDENTIFICATION OF THE AVIAN PATHOTYPE OF ESCHERICHIA COLI ON LAYER FLOCKS BY MULTIPLEX PCR

CBU International Conference Proceedings ◽

10.12955/cbup.v7.1473 ◽

2019 ◽

Vol 7 ◽

pp. 905-911

Author(s):

Marilena Burtan ◽

Virgilia Popa ◽

Maria Rodica Gurau ◽

Doina Danes

Keyword(s):

Escherichia Coli ◽

Multiplex Pcr ◽

Virulence Genes ◽

Virulence Gene ◽

Economic Losses ◽

Ompa Gene ◽

Avian Pathogenic Escherichia Coli ◽

E Coli ◽

Pathogenic Escherichia Coli

Introduction: Colibacillosis in poultry is determined by avian pathogenic Escherichia coli (APEC) and represents an important source of economic losses in the poultry industry. APEC’s pathogenicity relies on the presence and expression of different virulence factors. The genes ompA , iss and fimH, encoding the outer membrane protein, the protein inducing resistance to complement and the synthesis of type 1 fimbria are present in APEC strains. Objective: Escherichia coli strains isolated from layers were analysed to assess the pathotype they belong to. Methods: In order to detect the three genes associated with APEC strains, 16 E. coli isolates were investigated for virulence associated genes ompA, iss and fimH, using multiplex PCR. Results: From the 16 E.coli strains submitted, multiplex PCR assessment revealed that 14 (87.5%) of the E. coli strains isolated contained at least one virulence gene, while 2 (12.5%) strains did not harbour any of the virulence genes tested. The fimH gene was noted in 13 (81.25%) of the strains tested, the ompA gene has been present in 12 (75%) strains and the iss gene was present in 9 (56.25%) strains. Eight (50%) strains were found to present all three investigated genes. Conclusion: Presence of these genes is a strong indicatory to consider those strains as belonging to the APEC pathotype.

Download Full-text