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In silico analysis of virulence associated genes in genomes of Escherichia coli strains causing colibacillosis in poultry
2017
Kołsut, Joanna | Borówka, Paulina | Marciniak, Błażej | Wójcik, Ewelina | Wojtasik, Arkadiusz | Strapagiel, Dominik | Dastych, Jarosław
Introduction: Colibacillosis – the most common disease of poultry, is caused mainly by avian pathogenic Escherichia coli (APEC). However, thus far, no pattern to the molecular basis of the pathogenicity of these bacteria has been established beyond dispute. In this study, genomes of APEC were investigated to ascribe importance and explore the distribution of 16 genes recognised as their virulence factors. Material and Methods: A total of 14 pathogenic for poultry E. coli strains were isolated, and their DNA was sequenced, assembled de novo, and annotated. Amino acid sequences from these bacteria and an additional 16 freely available APEC amino acid sequences were analysed with the DIFFIND tool to define their virulence factors. Results: The DIFFIND tool enabled quick, reliable, and convenient assessment of the differences between compared amino acid sequences from bacterial genomes. The presence of 16 protein sequences indicated as pathogenicity factors in poultry resulted in the generation of a heatmap which categorises genomes in terms of the existence and similarity of the analysed protein sequences. Conclusion: The proposed method of detection of virulence factors using the capabilities of the DIFFIND tool may be useful in the analysis of similarities of E. coli and other sequences deriving from bacteria. Phylogenetic analysis resulted in reliable segregation of 30 APEC strains into five main clusters containing various virulence associated genes (VAGs).
Afficher plus [+] Moins [-]Phylogenetic grouping and virulence gene profiles of Escherichia coli isolated from chicken
2017
Ramlan M. | S. Khairani Bejo | Khoo, E. | Roseliza R. | Zunita Z.
Colibacillosis is a disease caused by avian pathogenic E. coli (APEC) and is one of the principle cause of morbidity and mortality in poultry worldwide which is represented by a complex syndrome characterized by multiple organ lesions. This study was carried out to determine phylogenetic grouping and virulenceassociated genes contained by E. coli isolates which is related in causing disease in chicken. E. coli isolates obtained from clinical cases of Veterinary ResearchInstitute were re-identified by conventional methods. Phylogenetic grouping of the isolates was determined by triplex polymerase chain reaction (PCR), and the presence of eight virulence genes were identified by multiplex PCR. A total of 125 E. coli isolates were subjected toanalysis of phylogenetic background and virulence associated genes profiling. Phylogenetic analysis demonstrated that most of the E. coli isolated from chicken in this study belonged to group B1 (36.0%),group D (28.0%), group A (27.2%) and group B2 (8.8%). Multiplex PCR analysis demonstrated that 96 (78.6%) of the E. coli isolates harbored at least one virulencegene, while 29 (23.3%) did not contain any virulence genes tested. The most prevalent virulence genes identified were iss (51.2%), followed by iucD (36.0%),tsh (32.8%), vat (16.0%), astA (13.6%), irp2 (11.2%), papC (9.6%) and the least is cva/cvi gene (0%). None of the isolates harbored more than four virulence genes.Each of phylogenetic groups presented with different combinations of virulence genes, with no specific combinations of virulence genes found to correlate withE. coli phylogroups. None of the E. coli isolates harbored more than four virulence genes, suggesting that E. coli isolates from chicken in this study appear to bederived from commensal strains and may relate to environmental predispose factors especially stress factors in the host to establish infection.
Afficher plus [+] Moins [-]Fascioliasis in an adult draught buffalo in Malaysia: a case report
2017
Rosilawati K. | Ramli S. | Saipul Bahari A. R.
Fascioliasis is an importantparasitic disease caused by the liver flukeFasciola gigantica in Malaysia. Theinfestation of liver fluke in ruminants;cattle, sheep, goats and buffaloes can resultin economic losses to the country mainlydue to the drop in livestock production,reduction in growth rate, condemnationof liver, reduction in draught power andhigh usage of anthelmintics. This paperdescribes a case of liver fluke infestationin a two year old male buffalo that waseventually slaughtered. The buffalowas reported to be emaciated and wasreared in an oil palm plantation for useas draught power in buffalo-drawn cartsloaded with oil palm bunches; alongwith 18 other buffaloes of various ages.Previously, there were two cases of buffalodeaths from the same herd. The organand faecal samples were sent to KuantanRegional Veterinary Laboratory (RVL)for diagnostic work up. The receivedsamples were then sent to parasitology,histopathology and bacteriology sectionsfor laboratory analysis and confirmationon the pathogens. The bacteriology resultshowed Escherichia coli isolated in allinternal organs. Presence of adult flukes(Fasciola gigantica) were observed inthe bile duct of the liver through grossexamination and also histopathologicalevaluation and supported by the positiveresult of Fasciola ova via sedimentationtest conducted from the faecal sample, thusjustifying the final diagnosis as severe liverfluke infestation leading to emaciation andsimultaneously having colibacillosis.
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