Nosocomial pseudo-outbreak of Mycobacterium gordonae associated with a hospital's water supply contamination: a case series of 135 patients

Abstract

Nontuberculous mycobacteria (NTM) are opportunistic pathogens found in natural and human-engineered waters. In 2009, a relative increase in the isolation of Mycobacterium gordonae from pulmonary samples originating from General Hospital Zabok was noted by the National Mycobacteria Reference Laboratory. An epidemiological survey revealed a contamination of the cold tap water with M. gordonae and guidelines regarding sputum sample taking were issued. In addition, all incident cases of respiratory infection due to NTM reported from 2007 to 2012 at General Hospital Zabok were included in a retrospective review. Out of 150 individual NTM isolates, M. gordonae was the most frequently isolated species (n = 135; 90%) and none of the cases met the criteria of the American Thoracic Society for pulmonary NTM disease. While concomitant Mycobacterium tuberculosis infection was confirmed in only 6 (4%) patients, anti-tuberculosis treatment was initiated for a significant portion of patients (n = 64; 42.6%) and unnecessary contact tracing was performed. This study points out the need to enhance the knowledge about NTM in our country and indicates the importance of faster NTM identification, as well as the importance of good communication between laboratory personnel and physicians when evaluating the significance of the isolated NTM.

Microbiological criteria in non-tuberculous mycobacteria pulmonary disease: a tool for diagnosis and epidemiology

“…M. gordonae was the most commonly isolated NTM species, with a peak isolation frequency in 2009 (data not shown) that can be explained by contamination of tap water with M. gordonae in one hospital. 20 In contrast, clinically relevant NTM species were more common in the coastal region. Some of the factors that might promote these regional differences include the climate, the rate of urbanization and different rates of TB incidence.…”

Pseudo-outbreak of Mycobacterium paragordonae in a hospital: possible role of the aerator/rectifier connected to the faucet of the water supply system

“…NTM detection in clinical samples such as sputum does not always imply infection, and the possibility of patient colonization or environmental contamination needs to be considered [7]. In particular, there have been many reports of M. gordonae causing pseudooutbreaks in hospitals, related to contamination of water supply systems [3,8,9].…”

Peptidomic analysis of mycobacterial secreted proteins enables species identification

“…This has significant clinical implications, since effective treatment of MAC, Mtb , and M. kansasii infections require the use of different drug regimens, [ 50,51 ] while M. gordonae ‐positive cultures frequently represent MGIT culture contamination and this can thus affect the decision to treat a patient. [ 4 ] Further, this IP‐MS was able to identify both species in two MGIT cultures that grew both MAC and M. kansasii. Such cultures can potentially confound species identifications in sequencing‐, probe‐, or MS‐based methods if they produce overlapping target signals or signal fingerprints that obscure the identity of the species present.…”

“…NTM infection rates can exhibit different geographic distributions, but certainly slow-growing NTM (e.g., MAC, M. gordonae, M. xenopi, and M. kansasii) and rapidly growing NTM (M. abscessus and M. fortuitum) tend to be the most prevalent NTM isolates worldwide, [3] while M. gordonaepositive isolates are frequently the result of environmental contamination. [4] In the United States, MAC is the most common cause of pulmonary NTM infection, followed by M. kansasii, and M. abscessus is responsible for most pulmonary NTM infections caused by rapidly growing NTM species. [5,6] Effective treatment of Mtb and NTM infections requires accurate identification of the responsible mycobacterial species or species complexes (e.g., M. abscessus, M. kansasii, or the Mtb and MAC complexes) since different species require different interventions.…”