Phylogenetic analysis of Escherichia coli strains isolated from human samples

Document Type : Original article

Authors

1 Department of Pathobiology School of Veterinary Medicine Shiraz University Shiraz, 71345-1731 Iran

2 Dept. of Bacteriology & Virology Shiraz Medical School Shiraz University of Medical Sciences P.O. Box 71455-119, Shiraz 71455, Iran.

3 PhD student in Department of Pathobiology School of Veterinary Medicine Shiraz University Shiraz, 71345-1731 Iran

Abstract

Escherichia coli (E. coli) is a normal inhabitant of the gastrointestinal tract of vertebrates, including humans. Phylogenetic analysis has shown that E. coli is composed of four main phylogenetic groups (A, B1, B2 and D). Group A and B1 are generally associated with commensals, whereas group B2 is associated with extra-intestinal pathotypes. Most enteropathogenic isolates, however, are assigned to group D. In the present study, a total of 102 E. coli strains, isolated from human samples, were used. Phylogenetic grouping was done based on the Clermont triplex PCR method using primers targeted at three genetic markers, chuA, yjaA and TspE4.C2. Group A contained the majority of the collected isolates (69 isolates, 67.64%), followed by group B2 (18 isolates, 17.64%) and D (15 isolates, 14.7%) and no strains were found to belong to group B1. The distribution of phylogenetic groups in our study suggests that although the majority of strains were commensals, the prevalence of enteropathogenic and extra-intestinal pathotypes was noteworthy. Therefore, the role of E. coli in human infections including diarrhea, urinary tract infections and meningitis should be considered.

Keywords


1.Donnenberg M. Escherichia coli virulence mechanisms of versatile pathogen. Elsevier Science, San Diego Calif. 2002.
2.Eisenstein BI, Joes GW. The spectrum of infections and pathogenic mechanisms of Escherichia coli. Adv Intern Med 1998;33:231-252.
3.Gordon D, Cowling A. The distribution and genetic structure of Escherichia coli in Australian vertebrates: host and geographic effects. Microbiology 2003;149:3575-3586.
4.Orskov F, Orskov I. Escherichia coli serotyping and disease in man and animals. Can J Microbiol 1992;38:699-704.
5.Desjardins P, Picard B, Kaltenbock B, Elion J, Denamur E. Sex in Escherichia coli does not disrupt the clonal structure of the population: evidence from random amplified polymorphic DNA and restriction-fragment-length polymorphism. J Mol Evol 1995; 40:440-448.
6.Gordon DM. The influence of ecological factors on the distribution and genetic structure of Escherichia coli. In Escherichia coli and Salmonellatyphimurium. American Society for Microbiology 2004 [http:// www.ecosal.org/ecosal/index.jsp].
7.Herzer PJ, Inouye S, Inouye M, Whittam TS. Phylogenetic distribution of branched RNA-linked multicopy single-stranded DNA among natural isolates of Escherichia coli. J Bacteriol 1990;172:6175-6181.
8.Johnson JR, Delavari P, Kuskowski M, Stell AL. Phylogenetic distribution of extraintestinal virulence-associated traits in Escherichia coli. J Infect Dis 2001;183:78-88.
9.Bashir S, Haque A, Sarwar Y, Anwar A, Anwar M. Virulence profile of different phylogenetic groups of locally isolated community acquired uropathogenic E. coli from Faisalabad region of Pakistan. Ann Clin Microbiol Antimicrob 2012;11:23.
10.Bingen E, Picard B, Brahimi N, Mathy S, Desjardins P, Elion J, Denamur E. Phylogenetic analysis of Escherichia coli strains causing neonatal meningitis suggests horizontal gene transfer from a predominant pool of highly virulent B2 group strains. J Infect Dis 1998;177:642-650.
11.Boyd E, Hartl D. Chromosomal regions specific to pathogenic isolates of Escherichia coli have a phylogenetically clustered distribution. J Bacteriol 1998;180:1159-1165.
12.Escobar-Paramo P, Clermont O, Blanc-Potard A, Bui H, Le Bouguenec C, Denamur E. A specific genetic background is required for acquisition and expression of virulence factors in Escherichia coli. Mol Biol Evol 2004;21:1085-1094.
13.Picard B, Garcia JS, Gouriou S, Duriez P, Brahimi N, Bingen E, Elion J, Denamur E. The link between phylogeny and virulence in Escherichia coliextraintestinal infection. Infect Immun 1999;67:546-553.
14.Duriez P, Clermont O, Bonacorsi S, Bingen E, Chaventre A, Elion J, Picard B, Denamur E. Commensal Escherichia coli isolates are phylogenetically distributed among geographically distinct human populations. Microbiology 2001;147:1671-1676.
15.Ochman H, Selander RK. Standard reference strains of Escherichia coli from natural populations. J Bacteriol 1984;157:690-693.
16.Arnold C, Metherell L, Willshaw G, Maggs A, Stanley J. Predictive fluorescent amplified-fragment length polymorphism analysis of Escherichia coli: high-resolution typing method with phylogenetic significance. J Clin Microbiol 1999;37:1274-1279.
17.Clermont O, Bonacorsi S, Bingen E. Rapid and simple determination of the Escherichia coli phylogenetic group. Appl Environ Microbiol 2000;66:4555-4558.
18.Diamant E, Palti Y, Gur-Arie R, Cohen H, Hallerman E, Kashi Y. Phylogeny and strain typing of Escherichia coli, inferred from variation at mononucleotide repeat loci. Appl Environ Microbiol 2004;70:2464-2473.
19.Lecointre G, Rachdi L, Darlu P, Denamur E. Escherichia coli molecular phylogeny using the incongruence length difference test. Mol Biol Evol 1998;15:1685-1695.
20.Reid S, Herbelin C, Bumbaugh A, Selander R, Whittam T. Parallel evolution of virulence in pathogenic Escherichia coli. Nature 2000;406:64-67.
21.Urwin R, M Maiden. Multi-locus sequence typing: a tool for global epidemiology. Trends Microbiol 2003;11:479-487.
22.Gordon DM, Clermont O, Tolleyand H, Denamur E. Assigning Escherichia coli strains to phylogenetic groups: multi-locus sequence typing versus the PCR triplex method. Environ Microbiol 2008;10:2484-2496.
23.Abdallah KS, Cao Y, Wei DJ. Epidemiologic Investigation of Extra-intestinal pathogenic E. coli (ExPEC) based on PCR phylogenetic group and fimH single nucleotide polymorphisms (SNPs) in China. Int J Mol Epidemiol Genet 2011;2:339-353.
24.Sambrook , Fritsch EF, Maniatis T. Molecular Cloning: a laboratory manual.1998. 2nd edition. N.Y., Cold Spring Harbor Laboratory, Cold Spring Harbor Laboratory Press.
25.Walk ST, Alm EW, Calhoun LM, Mladonicky JM, Whittam TS. Genetic diversity and population structure of Escherichia coli isolated from freshwater beaches. Environ Microbiol 2007;9:2274-2288.
26.Sabarinath A,Tiwari KP,Deallie C,Belot G,Vanpee G, Matthew V, Sharma R, Hariharan H. Antimicrobial resistance and phylogenetic groups of commensal Escherichia Coli isolates from healthy pigs in Grenada. Webmed Central Vet Med 2011;25,WMC001942.
27.Bingen-Bidois M, Clermont O, Bonacorsi S, Terki M, Brahimi N, LoukilCh, Barraud D, Bingen E. Phylogenetic analysis and prevalence of Urosepsis strains of Escherichia coli bearing pathogenicity island-like domains. Infect Immun 2002;70:3216-3226.
28.Obata-Yasuoka M, Ba-Thein W, Tsukamoto T, Yoshikawa H, Hayashi H. Vaginal Escherichia coli share common virulence factor profiles, serotypes and phylogeny with other extraintestinal E. coli. Microbiology 2002;148:2745-2752.
29.Moreno E, Andreu A, Pigrau C, A Kuskowski M, R Johnson J, Prats G. Relationship between Escherichia coli Strains Causing Acute Cystitis in Women and the Fecal E. coli Population of the Host. J Clin Microbiol 2008;46:2529-2534.
30.Bukh AS, Schonheyder HC, Emmersen JMG, Sogaard M, Bastholm S, Roslev P. Escherichia coli phylogenetic groups are associated with site of infection and level of antibiotic resistance in community-acquired bacteraemia: a 10 year population-based study in Denmark. J Antimicrob Chemother 2009;64:163-168.
31.Smati M, Clermont O, Gal FL, Schichmanoff O, Jauréguy F, Eddi A, Denamur A, Picard B. Real-time PCR for quantitative analysis of human commensal Escherichia coli populations reveals a high frequency of sub-dominant phylogroups. Appl Environ Microbiol 2013;79:5005-5012.