Phenotypic and molecular characteristics of Escherichia coli isolated from aquatic environment of Bangladesh

Munirul Alam, [No Value] Nur-A-Hasan, Sunjukta Ahsan, Gururaja Perumal Pazhani, Kazumichi Tamura, Thadavarayan Ramamurthy, Donald James Gomes, Sabita R. Rahman, Atiqul Islam, Fahmina Akhtar, Sumio Shinoda, Haruo Watanabe, Shah M. Faruque, Gopinath Balakrish Nair

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Pathogenic Escherichia coli remains important etiological agent of infantile diarrhea in Bangladesh. Previous studies have focused mostly on clinical strains, but very little is known about their presence in aquatic environments. The present study was designed to characterize potentially pathogenic E. coli isolated between November 2001 and December 2003 from aquatic environments of 13 districts of Bangladesh. Serotyping of 96 randomly selected strains revealed O161 to be the predominant serotype (19%), followed by O55 and O44 (12% each), and 11% untypable. Serotype-based pathotyping of the E. coli strains revealed 47%, 30%, and 6% to belong to EPEC, ETEC, and EHEC pathotypes, respectively. The majority of the 160 strains tested were resistant to commonly used antimicrobial agents. Plasmid profiling showed a total of 17 different bands ranging from 1.3 to 40 kb. However, 35% of the strains did not contain any detectable plasmid, implying no correlation between plasmid and drug resistance. Although virulence gene profiling revealed 97 (61%) of the strains to harbor the gene encoding heat-stable enterotoxin (ST), 2 for the gene encoding Shiga toxin (Stx), and none for the gene for heat-labile enterotoxin (LT), serotype-based pathotyping of E. coli was not fully supported by this gene profiling. A dendrogram derived from the PFGE patterns of 22 strains of three predominant serogroups indicated two major clusters, one containing mainly serogroup O55 and the other O8. Three strains of identical PFGE profiles belonging to serogroup O55 were isolated from three distinct areas, which may be of epidemiological significance. Finally, it may be concluded that serotype-based pathotyping may be useful for E. coli strains of clinical origin; however, it is not precise enough for reliably identifying environmental strains as diarrheagenic.

Original languageEnglish
Pages (from-to)359-370
Number of pages12
JournalMicrobiology and Immunology
Volume50
Issue number5
Publication statusPublished - 2006

Fingerprint

Bangladesh
Escherichia coli
Plasmids
Genes
Hot Temperature
Infantile Diarrhea
Shiga Toxin
Enterohemorrhagic Escherichia coli
Enterotoxigenic Escherichia coli
Enteropathogenic Escherichia coli
Serotyping
Enterotoxins
Anti-Infective Agents
Serogroup
Drug Resistance
Virulence

Keywords

  • Environmental E. coli
  • Pathotypes
  • PFGE
  • Serotypes

ASJC Scopus subject areas

  • Immunology and Microbiology(all)
  • Microbiology (medical)
  • Microbiology

Cite this

Alam, M., Nur-A-Hasan, N. V., Ahsan, S., Pazhani, G. P., Tamura, K., Ramamurthy, T., ... Nair, G. B. (2006). Phenotypic and molecular characteristics of Escherichia coli isolated from aquatic environment of Bangladesh. Microbiology and Immunology, 50(5), 359-370.

Phenotypic and molecular characteristics of Escherichia coli isolated from aquatic environment of Bangladesh. / Alam, Munirul; Nur-A-Hasan, [No Value]; Ahsan, Sunjukta; Pazhani, Gururaja Perumal; Tamura, Kazumichi; Ramamurthy, Thadavarayan; Gomes, Donald James; Rahman, Sabita R.; Islam, Atiqul; Akhtar, Fahmina; Shinoda, Sumio; Watanabe, Haruo; Faruque, Shah M.; Nair, Gopinath Balakrish.

In: Microbiology and Immunology, Vol. 50, No. 5, 2006, p. 359-370.

Research output: Contribution to journalArticle

Alam, M, Nur-A-Hasan, NV, Ahsan, S, Pazhani, GP, Tamura, K, Ramamurthy, T, Gomes, DJ, Rahman, SR, Islam, A, Akhtar, F, Shinoda, S, Watanabe, H, Faruque, SM & Nair, GB 2006, 'Phenotypic and molecular characteristics of Escherichia coli isolated from aquatic environment of Bangladesh', Microbiology and Immunology, vol. 50, no. 5, pp. 359-370.
Alam M, Nur-A-Hasan NV, Ahsan S, Pazhani GP, Tamura K, Ramamurthy T et al. Phenotypic and molecular characteristics of Escherichia coli isolated from aquatic environment of Bangladesh. Microbiology and Immunology. 2006;50(5):359-370.
Alam, Munirul ; Nur-A-Hasan, [No Value] ; Ahsan, Sunjukta ; Pazhani, Gururaja Perumal ; Tamura, Kazumichi ; Ramamurthy, Thadavarayan ; Gomes, Donald James ; Rahman, Sabita R. ; Islam, Atiqul ; Akhtar, Fahmina ; Shinoda, Sumio ; Watanabe, Haruo ; Faruque, Shah M. ; Nair, Gopinath Balakrish. / Phenotypic and molecular characteristics of Escherichia coli isolated from aquatic environment of Bangladesh. In: Microbiology and Immunology. 2006 ; Vol. 50, No. 5. pp. 359-370.
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