J Bacteriol Virol.  2006 Sep;36(3):133-139. 10.4167/jbv.2006.36.3.133.

Antimicrobial Resistance and Integrons Found in Commensal Escherichia coli Isolates from Healthy Humans

• Lee JC
• Kang HY
• Oh JY
• Jeong JH
• Seol SY
• Cho DT
• Kim J
• Lee YC

• KMID: 2055020
• DOI: http://doi.org/10.4167/jbv.2006.36.3.133

Abstract

The emergence and spread of antimicrobial resistance among the pathogenic and commensal Enterobacteriaceae are of great concern worldwide. We characterized the antimicrobial resistance and integrons found in commensal Escherichia coli from healthy humans in the community. Class 1 integrase (intl1) and class 2 integrase (intl2) genes were identified in 22 (13.3%) and 2 (1.2%) of 165 E. coli isolates, respectively. dfrA17-aadA5 and dfrA1-aadA2 were the most common class 1 integrons. The prevalence of each type of class 1 integron among commensal E. coli isolates during 2001~2003 was similar to that of clinical E. coli isolates from hospital-acquired infections during 1994~1999. The resistant rates of commensal E. coli isolates carrying intl1 to ampicillin, streptomycin, gentamicin, sulfamethoxazole, trimethoprim, chloramphenicol, and tetracycline were significantly higher than those of intl1-negative E. coli isolates (p<0.05). Integrons were directly associated with multidrug resistance in commensal E. coli isolates. It is hypothesized that multidrug-resistant Enterobacteriaceae from hospital-acquired infections are a potential reservoir for integrons associated with resistance genes found in commensal E. coli isolates in the community

Keyword

Integron; Commensal fecal flora; Escherichia coli; Multiresistance

MeSH Terms

Ampicillin
Chloramphenicol
Drug Resistance, Multiple
Enterobacteriaceae
Escherichia coli*
Escherichia*
Gentamicins
Humans*
Integrases
Integrons*
Prevalence
Streptomycin
Sulfamethoxazole
Tetracycline
Trimethoprim
Ampicillin
Chloramphenicol
Gentamicins
Integrases
Streptomycin
Sulfamethoxazole
Tetracycline
Trimethoprim

Figure

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  Figure 1. PCR amplification of gene cassette regions of class 1 and 2 integrons. Lane 1–6, class 1 integron carrying dfrA17-aadA5, dfrA1-aadA2, dfrA12-orfF-aadA2, dfrA5, dfrA7, and aadA1, respectively. Lane 7, class 2 integron carrying dfrA1-sat-aadA1. Lane M, lambda DNA fragments digested with HindIII.

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  Figure 2. Multiplicity of antimicrobial resistance and its association with the presence of integrons in commensal E. coli isolates. E. coli isolates were examined for antimicrobial susceptibility to 15 agents.

Reference

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