Molecular epidemiological study of Moraxella catarrhalis isolated from nosocomial respiratory infection patients in a community hospital in Japan

Intern Med. 2009;48(10):797-803. doi: 10.2169/internalmedicine.48.2036. Epub 2009 May 15.

Abstract

Background: Moraxella catarrhalis, occasionally, plays the essential role in nosocomial respiratory infection (NRI). Few studies have reported the route by which this organism spreads in a nosocomial infection outbreak. We identified characteristics of the strains isolated from NRI and attempted to reveal the potential nosocomial transmission routes.

Methods: A follow-up study has been performed in a Japanese community hospital between July 2002 and January 2003. M. catarrhalis clinical isolates were identified and beta-lactamase production test as well as the minimal inhibitory concentrations (MICs) have been examined. Pulsed-field gel electrophoresis (PFGE) and the multi locus sequence typing method (MLST) have been introduced as the effective "fingerprinting" methods.

Results: A total of 29 strains were isolated from 17 participants; 7 independent DNA fragment patterns were detected by PFGE. Pattern B (defined in this study) was dominant, and was detected both in strains from a health care worker (HCW) and inpatients. In the 9 selected strains analyzed by MLST, 7 unique MLST types were identified, which showed the congruence with the results of PFGE results.

Conclusion: Epidemiological analysis proved the transmission route from patient to patient, and suggested that more studies should be focused on identifying the possible transmission route between HCWs and inpatients.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cross Infection / epidemiology*
  • Cross Infection / microbiology*
  • Cross Infection / transmission
  • DNA Fingerprinting
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Hospitals, Community
  • Humans
  • Infectious Disease Transmission, Professional-to-Patient
  • Japan / epidemiology
  • Male
  • Middle Aged
  • Molecular Epidemiology
  • Moraxella catarrhalis / classification
  • Moraxella catarrhalis / genetics*
  • Moraxella catarrhalis / isolation & purification
  • Moraxellaceae Infections / epidemiology*
  • Moraxellaceae Infections / microbiology*
  • Moraxellaceae Infections / transmission
  • Phylogeny
  • Respiratory Tract Infections / epidemiology*
  • Respiratory Tract Infections / microbiology*
  • Respiratory Tract Infections / transmission
  • Young Adult

Substances

  • DNA, Bacterial