Mycobacterium gordonae pseudoinfection associated with a contaminated antimicrobial solution

Mycobacterium gordonae: the canary in the coal mine?

Mycobacterium gordonae (M. gordonae) is a species of nontuberculous mycobacteria (NTM) that rarely causes infection. It has previously been labeled the most common NTM contaminant. Bronchiectasis is a disease characterized by abnormal airway dilation leading to chronic cough, sputum production and pulmonary infections. Patients with bronchiectasis are at higher risk of NTM-lung disease with more pathogenic NTM species including Mycobacterium avium complex (MAC) and Mycobacterium abscessus (M. abscessus). The relationship between bronchiectasis and less-pathogenic NTM species such as M. gordonae is less well understood. We performed a retrospective study on patients who had M. gordonae isolated from respiratory specimens at UConn Health between May 2nd, 2010 and October 18th, 2022. M. gordonae was isolated 74 times from 56 patients. It was isolated 35 (47.3%) times from 31 patients with bronchiectasis and 39 (52.7%) times from 26 patients without bronchiectasis. Data was available on all mycobacterial cultures sent from May 2nd 2018 to October 18th 2022. Mycobacterial cultures sent from patients with bronchiectasis were significantly more likely to grow M. gordonae than patients without bronchiectasis (4.3% vs. 1.6%, P=0.007). Furthermore, when considered at the patient level, there remained a significant increased rate of M. gordonae isolation among patients with bronchiectasis (7.1% vs. 2.2%, P<0.001). We then looked at past and future isolation of more pathogenic NTM species and found a non-statistically increased rate of isolation of more pathogenic NTM species including MAC and M. abscessus in patients with bronchiectasis (45.2% vs. 29%, P=0.09). Based on our results, isolation of M. gordonae should raise suspicion of chronic airway disease and defects in host immune response, such as those seen in bronchiectasis. Furthermore, isolation of M. gordonae may suggest increased risk of infection with more pathogenic NTM species such as MAC and M. abscessus.

Pseudo-outbreak of Mycobacterium gordonae Following the Opening of a newly constructed hospital at a Chicago Medical Center

OBJECTIVE To identify the source of a pseudo-outbreak of Mycobacterium gordonae DESIGN Outbreak investigation. SETTING University Hospital in Chicago, Ilinois. PATIENTS Hospital patients with M. gordonae-positive clinical cultures. METHODS An increase in isolation of M. gordonae from clinical cultures was noted immediately following the opening of a newly constructed hospital in January 2012. We reviewed medical records of patients with M. gordonae-positive cultures collected between January and December 2012 and cultured potable water specimens in new and old hospitals quantitatively for mycobacteria. RESULTS Of 30 patients with M. gordonae-positive clinical cultures, 25 (83.3%) were housed in the new hospital; of 35 positive specimens (sputum, bronchoalveolar lavage, gastric aspirate), 32 (91.4%) had potential for water contamination. M. gordonae was more common in water collected from the new vs. the old hospital [147 of 157 (93.6%) vs. 91 of 113 (80.5%), P=.001]. Median concentration of M. gordonae was higher in the samples from the new vs. the old hospital (208 vs. 48 colony-forming units (CFU)/mL; P<.001). Prevalence and concentration of M. gordonae were lower in water samples from ice and water dispensers [13 of 28 (46.4%) and 0 CFU/mL] compared with water samples from patient rooms and common areas [225 of 242 (93%) and 146 CFU/mL, P<.001]. CONCLUSIONS M. gordonae was common in potable water. The pseudo-outbreak of M. gordonae was likely due to increased concentrations of M. gordonae in the potable water supply of the new hospital. A silver ion-impregnated 0.5-μm filter may have been responsible for lower concentrations of M. gordonae identified in ice/water dispenser samples. Hospitals should anticipate that construction activities may amplify the presence of waterborne nontuberculous mycobacterial contaminants.

Pseudo-outbreak ofMycobacterium abscessusInfection Caused by Laboratory Contamination

Objective.

To investigate the cause(s) of an increased incidence of clinical cultures growingMycobacterium abscessusat a hospital in Florida.

Design.

Outbreak investigation.

Setting.

University-affiliated, tertiary-care hospital.

Methods.

A site visit was done during the first week of September 2006. We reviewed the medical records of patients from whomM. abscessuswas recovered during the period from January 1, 2003, through June 30, 2006. We collected environmental samples from various sites and evaluated specimen processing procedures in the microbiology laboratory. Isolates ofM. abscessusrecovered from the environment and from 12 randomly selected patients who sought medical care in 2006 were compared by pulsed-field gel electrophoresis (PFGE). Follow-up case surveillance was continued through March 31, 2007.

Results.

Specimens from 143 patients obtained from various anatomical sites grewM. abscessuson culture in 2005-2006, compared with specimens from 21 patients in 2003-2004. The 12 isolates from patients that were selected for molecular typing had indistinguishable PFGE patterns. Observations revealed no major breaches in the processing of mycobacterial specimens in the laboratory. Isolates grew only after prolonged incubation (mean ± SD, 45 ± 15 days) in test tubes containing diagonally oriented Middlebrook and Cohn 7H10 agar or Lowenstein-Jensen medium. Environmental samples obtained from the inside of the specimen incubator grewM. abscessuson culture. A test tube containing diagonally oriented, uninoculated Middlebrook and Cohn 7H10 agar that was incubated in the same incubator as clinical specimens grewM. abscessuswith a PFGE pattern that matched the pattern of the patient isolates. Cases ofM. abscessusinfection decreased to baseline after the hospital changed suppliers of mycobacterial media and cleaned the incubator.

Conclusions.

Although the source was never confirmed, our investigation suggests that this was a pseudo-outbreak ofM. abscessusinfection that resulted from contamination of mycobacterial cultures during incubation. Our findings emphasize the need for guidance on the disinfection of specimen incubators.

Health care-associated infection outbreak investigations by the Centers for Disease Control and Prevention, 1946-2005

Since 1946, Centers for Disease Control and Prevention (CDC) personnel have investigated outbreaks of infections and adverse events associated with delivery of health care. CDC Epidemic Intelligence Service officers have led onsite investigations of these outbreaks by systematically applying epidemiology, statistics, and laboratory science. During 1946-2005, CDC Epidemic Intelligence Service officers conducted 531 outbreak investigations in facilities across the United States and abroad. Initially, the majority of outbreaks involved gastrointestinal tract infections; however, in later years, bloodstream, respiratory tract, and surgical wound infections predominated. Among pathogens implicated in CDC outbreak investigations, Staphylococcus aureus, Enterococcus species, Enterobacteriaceae, nonfermentative Gram-negative bacteria, or yeasts predominated, but unusual organisms (e.g., the atypical mycobacteria) were often included. Outbreak types varied and often were linked to transfer of colonized patients or health care personnel between facilities (multihospital outbreaks), national distribution of contaminated products, use of invasive medical devices, or variances in practices and procedures in health care environments (e.g., intensive care units, water reservoirs, or hemodialysis units). Through partnerships with health care facilities and local and state health departments, outbreaks were terminated and lives saved. Data from investigations invariably contributed to CDC-generated guidelines for prevention and control of health care-associated infections.

Isolation of nontuberculous mycobacteria in Zambia: eight case reports

The isolation of nontuberculous mycobacteria (NTM) raises the question of their clinical significance, especially in an African setting. We found a high percentage of NTM isolated from various specimens, including ones that are normally sterile, among 213 patients in Zambia. Because tuberculosis can affect all parts of the body, we decided to include patients who had signs and symptoms in any part of the body for more than 2 weeks. Most patients had tractus respiratorius (80%) and tractus digestivus (10%) symptoms. During three consecutive days, sputum was collected and two separate sputum specimens were cultured for mycobacteria. Depending on the clinical picture, pleural effusion, ascites, abscess material, or enlarged lymph nodes were also cultured for mycobacteria. A specimen from one sterile body site was collected from 25 patients (60% human immunodeficiency virus [HIV] positive). NTM were isolated from 8 of these 25 specimens. Mycobacterium lentiflavum was isolated from four patients, and Mycobacterium goodii was isolated from one patient. In order to exclude the possibility of laboratory cross-contamination, a novel amplified fragment length polymorphism DNA typing method for M. lentiflavum was developed. Genetic variation was detected, rendering the likelihood of laboratory contamination unlikely. Clinically relevant infection due to NTM occurs in both HIV-positive and HIV-negative patients in Zambia, and their clinical impact seems to be underestimated. This is the first report of M. lentiflavum and M. goodii infections in Africa.

Pseudoepidemic due to a unique strain of Mycobacterium szulgai: genotypic, phenotypic, and epidemiological analysis

In mid-1999, we noted multiple isolations at the Veterans Affairs Medical Center (VAMC) Houston Tex. of an unusual nonpigmented Mycobacterium species. Since, on the basis of 16S rRNA gene sequence analysis, the strains were identical to the Mycobacterium szulgai type strain and since M. szulgai has been reported only rarely as a commensal or environmental isolate, we were concerned about laboratory contamination, nosocomial spread, or even the possibility that this could be a novel organism associated with disease. Our investigation found that from 1999 to 2000, 37 strains of M. szulgai were isolated from patients at the VAMC (the base rate for the previous 10 years had been <1 isolation per year). We compared the phenotypic properties and genetic relatedness of these 37 strains (31 of which were nonpigmented) as well as eight stock strains and the M. szulgai type strain. All strains were similar in cellular fatty acid patterns, growth rates, and biochemical characteristics. However, we found three genogroups by gene sequence analysis. Genogroup I comprised the M. szulgai type strain, all the tested nonpigmented strains (27 of the 31 strains were tested), two pigmented strains isolated in 1999 and 2000, and five pigmented stock strains. Genogroup II comprised five pigmented strains: three were isolated from 1999 to 2000 and two were stock strains. The single strain (isolated in 1996) in genogroup III was pigmented and was the only strain associated with disease. Whereas the randomly amplified polymorphic DNA (RAPD) patterns of all nonpigmented strains were identical, indicating that they came from a common source (the pseudoepidemic strain), the RAPD patterns of the other strains were varied. In our investigation for a possible source, we found that there were no common reagents, specimen-processing or patient locations, or procedures linking the 31 pseudoepidemic strains. However, a nonpigmented M. szulgai strain with a gene sequence and RAPD pattern identical to those of the pseudoepidemic strain was recovered from a water storage tank serving the hospital. We concluded that the strains most likely originated from hospital water, which transiently inoculated our patients. Although no disease was associated with this cluster of isolates, the event was costly because identification was problematic and we could not easily discount the isolations, since most of the patients were immunocompromised and were candidates for opportunistic infection.

Nosocomial infections due to nontuberculous mycobacteria

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and cause colonization, infection, and pseudo-outbreaks in health care settings. Data suggest that the frequency of nosocomial outbreaks due to NTM may be increasing, and reduced hot water temperatures may be partly responsible for this phenomenon. Attention to adequate high-level disinfection of medical devices and the use of sterile reagents and biologicals will prevent most outbreaks. Because NTM cannot be eliminated from the hospital environment, and because they present an ongoing potential for infection, NTM should be considered in all cases of nosocomial infection, and careful surveillance must be used to identify potential outbreaks. Analysis of the species of NTM and the specimen source may assist in determining the significance of a cluster of isolates. Once an outbreak or pseudo-outbreak is suspected, molecular techniques should be applied promptly to determine the source and identify appropriate control measures.

Pseudo-outbreak of Mycobacterium gordonae associated with water from refrigerated fountains

Between March 1997 and December 1997, acid-fast bacilli (AFB) were detected on sputum and/or gastric aspirates smears from five patients hospitalized in the chest medicine department. These specimens grew M. gordonae. Based on AFB-positive smear and clinical presentation, four out of five patients received antituberculous treatment until species identification was known. Epidemiological investigation revealed a heavy contamination of water collected from refrigerated fountains located on the same floor as the patient cases. Strains isolated from four patients and the refrigerated fountain exhibited the same pulsed gel electrophoresis pattern (using DraI and XbaI enzymes) suggesting that positive smears were related to drinking water from the refrigerated fountain. This cluster of pseudo-infections underlines the necessity for a proper maintenance of water supply equipment in order to avoid inappropriate decisions deleterious for patients.

Nosocomial outbreaks/pseudo-outbreaks caused by nontuberculous mycobacteria

Nosocomial outbreaks and pseudo-outbreaks caused by the nontuberculous mycobacteria (NTM) have been recognized for more than 20 years and continue to be a problem. Most of these outbreaks have involved the rapidly growing mycobacterial species Mycobacterium fortuitum and M. abscessus. The reservoir for these outbreaks is generally municipal and (often separate) hospital water supplies. These mycobacterial species and others are incredibly hardy, able to grow in municipal and distilled water, thrive at temperatures of 45 degrees C or above (M. xenopi and M. avium complex), and resist the activity of organomercurials, chlorine, 2% concentrations of formaldehyde and alkaline glutaraldehyde, and other commonly used disinfectants. Disease outbreaks usually involve sternal wound infections, plastic surgery wound infections, or postinjection abscesses. Pseudo-outbreaks most commonly relate to contaminated bronchoscopes and endoscopic cleaning machines (M. abscessus) and contaminated hospital water supplies (M. xenopi). Knowledge of the reservoir of these species, their great survival capabilities within the hospital, and newer molecular techniques for strain comparison have helped control and more quickly identify current nosocomial outbreaks or pseudo-outbreaks caused by the NTM.

Endemic contamination of clinical specimens by Mycobacterium gordonae

Contamination of clinical specimens by Mycobacterium gordonae is a significant endemic problem in many laboratories. To investigate this problem, 84 cases at 1 hospital were retrospectively identified during 20 months. The overall rate of specimen contamination was 2. 4%, and 72 of the contaminated specimens were respiratory. A case-control comparison showed that the risk of respiratory specimen contamination was significantly increased if the specimen was expectorated (odds ratio [OR], 3.62; 95% confidence interval [CI], 1. 36-9.50) or if the patient consumed fluids within 2 days before specimen collection (OR, 8.92; 95% CI, 1.40-71.20). Cultures of tap water, ice, and iced drinking water all yielded M. gordonae at 10(-2)-10(0) cfu/mL. A culture survey of consenting patients showed contamination of 8 (24%) of 34 sputum specimens collected immediately after a tap water mouth rinse. These findings demonstrate that endemic specimen contamination arises from mycobacteria in hospital tap water and provide a foundation for control efforts.

Molecular analysis of Mycobacterium avium isolates by using pulsed-field gel electrophoresis and PCR

Genetic relationships among 46 isolates of Mycobacterium avium recovered from 37 patients in a 2,500-bed hospital from 1993 to 1998 were assessed by pulsed-field gel electrophoresis (PFGE) and PCR amplification of genomic sequences located between the repetitive elements IS1245 and IS1311. Each technique enabled the identification of 27 to 32 different patterns among the 46 isolates, confirming that the genetic heterogeneity of M. avium strains is high in a given community. Furthermore, this retrospective analysis of sporadic isolates allowed us (i) to suggest the existence of two remanent strains in our region, (ii) to raise the question of the possibility of nosocomial acquisition of M. avium strains, and (iii) to document laboratory contamination. The methods applied in the present study were found to be useful for the typing of M. avium isolates. In general, both methods yielded similar results for both related and unrelated isolates. However, the isolates in five of the six PCR clusters were distributed among two to three PFGE patterns, suggesting that this PCR-based method may have limitations for the analysis of strains with low insertion sequence copy numbers or for resolution of extended epidemiologic relationships.

Cloning of the antigen 85A from Mycobacterium gordonae and its use for the specific PCR identification of these mycobacteria

The complete nucleotide sequence of 85A antigen of Mycobacterium gordonae was determined. This gene encodes 339 amino acids, including 43 amino acids for the signal peptide, followed by a mature protein of 296 amino acids. A polymerase chain reaction (PCR) assay for the rapid detection of M. gordonae DNA using two pairs of oligonucleotide primers, derived from our sequence, is described. This one-step PCR has been used successfully to amplify 38 strains of M. gordonae. Conversely, the primers did not amplify DNA from any of the 25 mycobacterial species tested. The results suggest that this PCR assay could be a good alternative to existing commercial assays for the specific identification of M. gordonae on early culture on solid medium or on early BACTEC broth culture.

Investigation of a pseudo-outbreak of Nocardia asteroides infection by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA PCR

Molecular strain typing by pulsed-field gel electrophoresis and by randomly amplified polymorphic DNA analysis was used to investigate a cluster of four Nocardia asteroides isolates associated with the BACTEC 460 TB system. An instrument motor drive misalignment resulted in inadequate needle sterilization and cross-contamination of BACTEC vials. This pseudo-outbreak illustrates the importance of proper BACTEC 460 needle sterilization and maintenance and confirms the usefulness of molecular typing methods for epidemiologic investigations.

Nontuberculous mycobacterial infections

OBJECTIVE

To review the epidemiology, clinical manifestations, diagnosis, and treatment of nontuberculous mycobacterial infections other than Mycobacterium avium complex (MAC).

DATA SOURCES

A MEDLINE search of English-language literature pertaining to nontuberculous mycobacteria other than MAC was performed. Additional literature was obtained from reference lists of pertinent articles identified through the search.

STUDY SELECTION AND DATA EXTRACTION

All articles were considered for possible inclusion in the review. Information judged by the author to be pertinent was selected for discussion.

DATA SYNTHESIS

Mycobacterial infections, including those caused by nontuberculous mycobacteria other than MAC, have assumed greater importance over the past decade, due in part to the changing spectrum of immunosuppression as manifested by organ transplantation and HIV infection. Many pathogenic nontuberculous mycobacteria have been identified that are associated with a wide variety of localized, organ-specific, and systemic infections. Of concern, these organisms exhibit variable, species-specific susceptibility to traditional antimycobacterial drugs and other antimicrobials. In addition, long treatment courses and adjunctive surgical therapy are often required to effect cure. Important antimicrobials for the management of these infections include cefoxitin, imipenem/cilastatin, aminoglycosides (other than streptomycin), tetracyclines, macrolides, and trimethoprim/sulfamethoxazole, as well as traditional antimycobacterials.

CONCLUSIONS

Nontuberculous mycobacteria have assumed an increasing role in disease etiology in both nonimmunocompromised and immunocompromised individuals. Advent of rapid diagnostic techniques and susceptibility testing has allowed the clinician to identify these organisms and initiate effective treatment on a more timely basis with an improved chance for cure. Few therapeutic agents are available for treatment of these infections, many of which are not considered classic antimycobacterials.

Basic microbiologic support for hospital epidemiology

The laboratory plays a major role in the epidemiology program's efforts to minimize nosocomial infections in healthcare institutions. This article will describe some of the interactions between the laboratory and the epidemiology program, and will identify resources and procedures that the laboratory needs to achieve epidemiologic goals.

Evaluation of the relatedness of strains of Mycobacterium avium using pulsed-field gel electrophoresis

The application of molecular techniques to investigate strain relatedness may help define the local epidemiology of Mycobacterium avium infection, and, by identifying false isolates (i.e. neither pathogens nor colonizers) resulting from contamination, may serve as a tool for quality control in the laboratory. For this purpose, isolates from all patients (n = 129) with Mycobacterium avium infections identified over a two-year period were investigated by pulsed-field gel electrophoresis (PFGE). Of 38 PFGE patterns identified, 34 corresponded to unique strains or to isolates present in no more than two or three individuals. One prevalent strain was identified among HIV-infected patients and three patterns were related to culture contamination events. PFGE (i) established the diversity of Mycobacterium avium strains in a community; (ii) identified the existence of a unique strain that may account for one-fifth of Mycobacterium avium isolated from HIV-infected patients locally; (iii) documented the extent and resolution of a suspected pseudo-outbreak; and (iv) uncovered an additional-unsuspected contamination event.

Investigation of a pseudo-outbreak of orthopedic infections caused by Pseudomonas aeruginosa

OBJECTIVE

To report a pseudoepidemic of Pseudomonas aeruginosa infections discovered during an investigation of postoperative joint infections.

DESIGN

A retrospective review of case patients' hospital charts, operative reports, and laboratory data, as well as environmental culturing, polymerase chain reaction (PCR) ribotyping of outbreak isolates, and in vitro analysis of P aeruginosa growth characteristics.

SETTING

A 510-bed, university-affiliated adult tertiary care hospital.

RESULTS

Between October 1 and December 1, 1992, seven postsurgical joint infections were diagnosed, including four caused by P aeruginosa. A bottle of "sterile" saline used to process tissue specimens was found to be contaminated with P aeruginosa. Further investigation revealed that P aeruginosa had grown from seven additional tissue cultures, all of which had been processed with the contaminated saline. PCR ribotypes of the contaminant matched those of the clinical isolates. In vitro, P aeruginosa strains were viable in commercial nonbacteriostatic saline, but never caused visible turbidity. Six patients received antibiotics for their presumed infections; four patients had peripherally inserted central catheters placed, and one experienced severe anaphylactic reactions to several antibiotics.

CONCLUSIONS

Pseudoepidemics due to common organisms are often difficult to detect, and delayed recognition can result in substantial morbidity. This outbreak investigation illustrates the potential for contamination of diluents in the microbiology laboratory and emphasizes the need for meticulous quality control.

Mycobacterium gordonae: a treatable disease in HIV-positive patients

PURPOSE

To evaluate the pathogenicity of Mycobacterium gordonae in patients with and without human immunodeficiency virus (HIV) infection.

PATIENTS AND METHODS

Twenty-one HIV-positive and 15 HIV-negative patients in a tertiary care center. A descriptive, case-control, and cohort study with a review of the literature with a computer-based data research.

RESULTS

The 15 HIV-negative patients had colonization only. Seven HIV-positive patients had colonization, 12 had possible disease, and 2 had dissemination. The two patients with definitive dissemination improved objectively with treatment.

CONCLUSION

Mycobacterium gordonae in HIV-negative patients is rarely a pathogen. In HIV-positive patients with a low CD4+ cell count, it can cause significant disease and treatment is beneficial.

Molecular strain typing of Mycobacterium tuberculosis to confirm cross-contamination in the mycobacteriology laboratory and modification of procedures to minimize occurrence of false-positive cultures

Molecular strain typing by restriction fragment length polymorphism analysis was used to demonstrate that two clusters of Mycobacterium tuberculosis cultures involving six patients resulted from cross-contamination in the mycobacteriology laboratory. Contaminated cultures were processed by the decontamination procedure and were read on the BACTEC instrument following acid-fast bacillus smear-positive specimens from patients with active tuberculosis. Investigation of these episodes suggested opportunities for modification of laboratory procedures to minimize cross-contamination and confirmed the adverse medical and public health consequences of false-positive cultures. Strain-typing results were used in decisions regarding patient care, including the curtailment of unnecessary treatment in one patient. Molecular strain typing appears to be a valuable means of identifying false-positive cultures of M. tuberculosis in selected settings.

Pseudoepidemic of nontuberculous mycobacteria due to a contaminated bronchoscope cleaning machine. Report of an outbreak and review of the literature

We describe a pseudoepidemic due to nontuberculous mycobacteria contaminating the water tank of a machine used to clean and disinfect fiberoptic endoscopes. Forty-six bronchoscopies performed on 41 patients during a six-month period yielded 16 specimens positive for acid-fast bacilli (AFB). One specimen showed Mycobacterium avium complex from an AIDS patient and one, M tuberculosis from a patient with active cavitary tuberculosis. In four patients, only the smears showed AFB; subsequent cultures remained negative. Of the rest, seven contained M chelonae and three M gordonae, all in patients with no clinical signs of mycobacterial disease. Two of the three M gordonae isolates represented laboratory contamination from an antimicrobial solution in a culture medium. Four patients in the beginning of the pseudoepidemic were treated for presumed tuberculosis until negative culture results were available. Control of the "outbreak" was achieved by regular disinfection of the implicated water tank in the cleaning machine. Contamination of bronchoscopes with nontuberculous mycobacteria can lead to unnecessary diagnostic and therapeutic interventions.

Pseudoepidemic of Nocardia asteroides associated with a mycobacterial culture system

Nocardia isolations increased from 0.7 to 11.7/1,000 acid-fast bacillus and mycological cultures (P less than 0.000001). Only three isolations from one patient represented infection. Pseudoepidemic strain identity was confirmed by DNA fingerprinting; the isolate causing infection was distinct. The end of the pseudoepidemic was associated with changing the needle sterilizer and prolonging needle sterilization time on the BACTEC 460 machine. To our knowledge, this is the first reported Nocardia asteroides pseudoepidemic.