First isolation of Mycobacterium canariasense from municipal water supplies in Tenerife, Canary Islands, Spain

Overlapping infections of Mycobacterium canariasense and Nocardia farcinica in an immunocompetent patient: A case report

BACKGROUND

Infections by non-tuberculous mycobacteria (NTM) have become more common in recent years. Mycobacterium canariasense (M. canariasense) was first reported as an opportunistic pathogen in 2004, but there have been very few case reports since then. Nocardia is a genus of aerobic and Gram-positive bacilli, and these species are also opportunistic pathogens and in the Mycobacteriales order. Conventional methods for diagnosis of NTM are inefficient. Metagenomic next-generation sequencing (mNGS) can rapidly detect many pathogenic microorganisms, even rare species. Most NTM and Nocardia infections occur in immunocompromised patients with atypical clinical symptoms. There are no previous reports of infection by M. canariasense and Nocardia farcinica (N. farcinica), especially in immunocompetent patients. This case report describes an immunocompetent 52-year-old woman who had overlapping infections of M. canariasense, N. farcinica, and Candida parapsilosis (C. parapsilosis) based on mNGS.

CASE SUMMARY

A 52-year-old woman presented with a productive cough and chest pain for 2 wk, and recurrent episodes of moderate-grade fever for 1 wk. She received antibiotics for 1 wk at a local hospital, and experienced defervescence, but the productive cough and chest pain persisted. We collected samples of a lung lesion and alveolar lavage fluid for mNGS. The lung tissue was positive for M. canariasense, N. farcinica, and C. parapsilosis, and the alveolar lavage fluid was positive for M. canariasense. The diagnosis was pneumonia, and application of appropriate antibiotic therapy cured the patient.

CONCLUSION

Etiological diagnosis is critical for patients with infectious diseases. mNGS can identify rare and novel pathogens, and does not require a priori knowledge.

The Presence of Opportunistic Premise Plumbing Pathogens in Residential Buildings: A Literature Review

Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbing environment and that present an emerging infectious disease problem. They share characteristics, such as disinfectant resistance, thermal tolerance, and biofilm formation. The colonisation of domestic water systems presents an elevated health risk for immune-compromised individuals who receive healthcare at home. The literature that has identified the previously described OPPPs (Aeromonas spp., Acinetobacter spp., Helicobacter spp., Legionella spp., Methylobacterium spp., Mycobacteria spp., Pseudomonas spp., and Stenotrophomonas spp.) in residential drinking water systems were systematically reviewed. By applying the Preferred reporting items for systematic reviews and meta-analyses guidelines, 214 studies were identified from the Scopus and Web of Science databases, which included 30 clinical case investigations. Tap components and showerheads were the most frequently identified sources of OPPPs. Sixty-four of these studies detected additional clinically relevant pathogens that are not classified as OPPPs in these reservoirs. There was considerable variation in the detection methods, which included traditional culturing and molecular approaches. These identified studies demonstrate that the current drinking water treatment methods are ineffective against many waterborne pathogens. It is critical that, as at-home healthcare services continue to be promoted, we understand the emergent risks that are posed by OPPPs in residential drinking water. Future research is needed in order to provide consistent data on the prevalence of OPPPs in residential water, and on the incidence of waterborne homecare-associated infections. This will enable the identification of the contributing risk factors, and the development of effective controls.

Emergence of Mycobacterium canariasense infections in central Israel

In 2018, Mycobacterium canariasense bloodstream infection was diagnosed in Israel. Further investigation had identified additional five cases in three medical centers, including isolates from blood (1), cornea (1), and sputum (3). Isolates were susceptible to all the antimicrobial tested. All but one isolate was related by whole-genome phylogeny.

Pseudo-outbreak of Mycobacterium fortuitum in a hospital bronchoscopy unit

BACKGROUND

Mycobacterium fortuitum survive in different environmental conditions, biofilm formation and resistance to chlorinated disinfectants makes its isolation frequent in hospital environments, even being involved in outbreaks by contamination of medical equipment such as bronchoscopes. We describe a pseudo-outbreak by M fortuitum isolated in samples from 9 patients who underwent bronchoscopy in the pneumology bronchoscopy unit of the University Hospital Complex of the Canary Islands from December 2016 to March 2017.

METHODS

We proceeded to investigate the pseudo-outbreak with a combination of epidemiologic, environmental, and molecular typing data.

RESULTS

The source/reservoir of pseudo-outbreak was the hospital water used by the bronchoscope automatic washing machine (without antibacterial filter), so control measures were taken. Molecular typing was performed on 7 strains from 7 patients, and a sample of water was collected from a tap in the pneumology bronchoscopy unit: all of which had the same pattern.

CONCLUSIONS

Our study demonstrates the presence of nontuberculous mycobacteria in the hospital water supply, and thus the need to take measures against them because they compromise patients' health. We also suggest the need for hospital water quality guidelines in which methods to control and/or eliminate them are established.

A Geospatial Epidemiologic Analysis of Nontuberculous Mycobacterial Infection: An Ecological Study in Colorado

RATIONALE

Nontuberculous mycobacteria (NTM) are ubiquitous environmental microorganisms. Infection is thought to result primarily from exposure to soil and/or water sources. NTM disease prevalence varies greatly by geographic region, but the geospatial factors influencing this variation remain unclear.

OBJECTIVES

To identify sociodemographic and environmental ecological risk factors associated with NTM infection and disease in Colorado.

METHODS

We conducted an ecological study, combining data from patients with a diagnosis of NTM disease from National Jewish Health's electronic medical record database and ZIP code-level sociodemographic and environmental exposure data obtained from the U.S. Geological Survey, the U.S. Department of Agriculture, and the U.S. Census Bureau. We used spatial scan methods to identify high-risk clusters of NTM disease in Colorado. Ecological risk factors for disease were assessed using Bayesian generalized linear models assuming Poisson-distributed discrete responses (case counts by ZIP code) with the log link function.

RESULTS

We identified two statistically significant high-risk clusters of disease. The primary cluster included ZIP codes in urban regions of Denver and Aurora, as well as regions south of Denver, on the east side of the Continental Divide. The secondary cluster was located on the west side of the Continental Divide in rural and mountainous regions. After adjustment for sociodemographic, drive time, and soil variables, we identified three watershed areas with relative risks of 12.2, 4.6, and 4.2 for slowly growing NTM infections compared with the mean disease risk for all watersheds in Colorado. This study population carries with it inherent limitations that may introduce bias. The lack of complete capture of NTM cases in Colorado may be related to factors such as disease severity, education and income levels, and insurance status.

CONCLUSIONS

Our findings provide evidence that water derived from particular watersheds may be an important source of NTM exposure in Colorado. The watershed with the greatest risk of NTM disease contains the Dillon Reservoir. This reservoir is also the main water supply for major cities located in the two watersheds with the second and third highest disease risk in the state, suggesting an important possible source of infection.