PURPOSE: Mycobacterium gordonae is an acid-fast bacterium commonly found in water. It is also called tap water bacillus. In most cases it is a laboratory contaminant or a colonizer. M. gordonae may rarely cause disease in severely immunocompromised patients with acquired immunodeficiency syndrome. Some physicians believe that it may also be pathogenic in patients with abnormal radiological findings and without immune deficiency. The aim of this study was to determine the change of prevalence of M. gordonae at our institution.
METHODS: Retrospective review of microbiology records of all cultures positive for acid fast bacilli, including M. gordonae from January 2005 to December 2007 at a tertiary care teaching hospital.
RESULTS: Eight hundred and one positive mycobacterial isolates were collected from 609 patients. Sixty seven were positive for M. gordonae as shown in the graphs. M. gordonae was mostly found in the sputum and bronchial wash samples. It was isolated from 4 wound samples, 1 pleural fluid sample and 1 lymph node sample. M. gordonae was not found in lung biopsies, urine, stool and other specimens. Linear trend analysis was performed which showed an increase in prevalence (chi square for linear trend is 1.44 and p = 0.22, EPIINFO 3.4.1). No evidence of clusters, suggesting contaminated laboratory specimens, was seen.
CONCLUSION: There is no evidence to suggest that M. gordonae is pathogenic including the isolates from pleural fluid and lymph node biopsy. The prevalence showed an increase, with M. gordonae predominantly isolated from the sputum and bronchial wash samples.M. gordonae is considered to be insignificant as a pathogen but its prevalence has been increasing, accounting for 6, 9.7 and 9.3 percent of all acid fast bacilli isolates during the years of 2005, 2006 and 2007, respectively. Although the prevalence of M. gordonae has been increasing, further investigations are necessary in patients with positive M. gordonae cultures to identify the source of infection before it can be attributed to M. gordonae.
CLINICAL IMPLICATIONS: A single isolate with M. gordonae does not indicate disease.
DISCLOSURE: Lalit Kanaparthi, None.