eMedicine Specialties > Infectious Diseases > Mycobacterial Infections

Mycobacterium gordonae

Klaus-Dieter Lessnau, MD, FCCP, Clinical Associate Professor of Medicine, New York University School of Medicine; Medical Director, Pulmonary Physiology Laboratory; Director of Research in Pulmonary Medicine, Department of Medicine, Section of Pulmonary Medicine, Lenox Hill Hospital
Cynthia de Luise, PhD, MPH, Director, Epidemiology, Pfizer, Inc

Updated: Nov 13, 2009

Introduction

Background

Advanced laboratory diagnostic techniques have improved the isolation and identification of nontuberculous mycobacteria. Mycobacterium gordonae, a commonly found species of mycobacteria, is named after its discoverer, the American bacteriologist Ruth E. Gordon. It is classified in Runyon group 2 as a scotochromogenic organism. Cultures grow slowly, are smooth, and are pigmented yellow. M gordonae is referred to as the tap water bacillus because it is a frequent isolate in tap water.¹

M gordonae is ubiquitous and may be found in soil, water (eg, ground, tap, bottled), whirlpools, unpasteurized milk, mucous membranes of healthy persons, urine, and gastric fluid. It is the most commonly encountered nontuberculous mycobacterium in water, with concentrations as high as 1000 colony-forming units per liter.

New cases of M gordonae disease should always be published to increase the knowledge of this disease. Many isolates represent contamination of the specimen or colonization, but not true disease. Discussing positive culture findings with microbiology laboratory personnel is useful. The authors are willing to discuss any possibly new case of M gordonae infection and are willing to offer support to write up cases of actual disease.

Pathophysiology

M gordonae is one of the least pathogenic of the mycobacteria. It is usually a contaminant or colonizer in patients who are not infected with HIV. However, in patients with HIV infection who are severely immunosuppressed (count of <100 CD4⁺ cells/µL), M gordonae may infect the lungs, blood, bone marrow, and other organs. In the few published case reports of M gordonae disease, pathogenicity was not always established because of the presence of single isolates, the lack of confirmation by a reference laboratory, or the rapid improvement of pulmonary infiltrates, which are not characteristic features of infections from other mycobacterial species.

Frequency

United States

M gordonae disease is rare. While more than 100 cases have been reported, most documentation supports contamination or colonization rather than pathogenicity. Nosocomial pseudo-outbreaks have been described from tap water, ice machines, antimicrobial and laboratory solutions, instrumentation, fiberoptic bronchoscopes and colonoscopes (especially if the working channel is not adequately exposed to disinfectant), aerosol devices, and (possibly) continuous ambulatory peritoneal dialysis fluid.

International

Worldwide distribution of M gordonae infection is probable. Additional studies with adequate documentation are warranted to investigate the pathogenicity of M gordonae.

Mortality/Morbidity

M gordonae infection carries a mortality rate of less than 0.1%. M gordonae may be a marker of severe immunosuppression in patients infected with HIV. One death was reported in a patient who was HIV positive and had severe immunosuppression, acute respiratory distress syndrome, and multiple isolates of M gordonae.

Race

M gordonae infection has no recognized racial predilection.

Sex

M gordonae infection has no known sexual predilection.

Age

M gordonae infection has no determined age predilection.

Clinical

History

• Fever (eg, >2 wk)

Physical

• Patients without HIV infection
  • Possible skin granuloma or nodule following injuries involving soil exposure (eg, gardeners)
  • Keratitis of the cornea (associated with previous trauma)
  • Lung infiltrates and/or nodules, small and thin-walled cavities in lungs
  • Possible hepatic or peritoneal infiltration or infection
  • Possible infection in urine
  • Possible prosthetic aortic valve or ventriculoatrial shunt infection
• Patients with HIV infection
  • Respiratory specimens with repeatedly high colony counts
  • Pulmonary infiltrates
  • Adult respiratory distress syndrome
  • Evidence of dissemination and disease (eg, cornea, peritoneal cavity, synovial fluid, urine)
  • Blood sepsis or dissemination

Causes

HIV infection with severe immunosuppression (<50 CD4⁺ cells/µL) is a risk factor for M gordonae infection.

Differential Diagnoses

Other Problems to Be Considered

Acquired immunodeficiency syndrome
Nontuberculous mycobacteria infection
Pseudo-outbreak
Colonization
Saprophyte
Contaminant

Workup

Laboratory Studies

• Documentation of M gordonae disease
• Microbiologic characteristics
  • Smear-positive specimens for acid-fast bacilli
  • Isolation of organism in large numbers, quantified as growth per culture in colony-forming units (ie, >100)
  • Repeated isolation of M gordonae (ie, more than twice)
  • Detection of specific biochemical characteristics (to prove identity)
  • Consideration of confirmation from a reference laboratory
• Isolation of M gordonae from a sterile source
• Positive result from tissue culture
• Histopathologic changes characteristic of M gordonae infection
• Repeat mycobacterial cultures of sputum, blood, bone marrow, and urine (if disease is suspected)
• Blood cultures to determine presence of mycobacterial organisms

Imaging Studies

• Obtain a chest radiograph in patients with respiratory symptoms.
• Use CT scanning of the lungs, abdomen, or both to evaluate for possible dissemination.
• Consider performing abdominal ultrasonography.

Procedures

• Fiberoptic bronchoscopy helps evaluate for infiltrates.
• Consider obtaining biopsy specimens (eg, from bone marrow) to help diagnose possible dissemination.

Histologic Findings

Acid-fast stains are positive for M gordonae, and/or granulomas are present.

Treatment

Medical Care

Collect more data to establish the presence of disease. Clinical response to specific antimycobacterial therapy indicates possible disease presence. As with other mycobacterial organisms, slow resolution of radiographic infiltrates is expected.

• The most effective treatment regimen has not been established, but in vitro susceptibilities suggest clarithromycin and, possibly, azithromycin, quinolones (especially levofloxacin), and ethambutol as treatment options. Rifabutin may be beneficial, and rifampin shows variable results.
• The recommended duration of therapy is not established, although treating patients until culture results are documented as negative is reasonable.
• Whether additional or extended (as with tuberculosis) treatment prevents relapse remains unknown.

Consultations

• Infectious disease specialist
• Pulmonologist
• Hematologist (if bone marrow is involved)

Medication

While the most effective treatment regimen has not been established, in vitro susceptibilities suggest clarithromycin and, possibly, azithromycin, quinolones (eg, levofloxacin, moxifloxacin), and ethambutol as treatment options. Rifabutin may be beneficial, and rifampin has shown variable results.

In vivo activity of doxycycline and trimethoprim-sulfamethoxazole is not known.

M gordonae has been shown to be resistant to isoniazid, pyrazinamide, and streptomycin.

The recommended duration of therapy is not established.

Antimycobacterials

Empiric antimycobacterial therapy must be comprehensive.

Clarithromycin (Biaxin)

Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Very active drug for nontuberculous mycobacterial disease, but acquired resistance from monotherapy is a concern.

Dosing

Adult

500-1000 mg PO bid

Pediatric

7.5 mg/kg PO bid

Interactions

To avoid uveitis, do not exceed 300 mg of rifabutin when used with clarithromycin; toxicity increases with coadministration of fluconazole, astemizole, and pimozide; effects decrease and adverse GI effects may increase with coadministration of rifabutin or rifampin; may increase toxicity of anticoagulants, cyclosporine, tacrolimus, digoxin, omeprazole, carbamazepine, ergot alkaloids, triazolam, and HMG CoA-reductase inhibitors; plasma levels of certain benzodiazepines may increase, prolonging CNS depression; arrhythmias and increase in QTC intervals occur with disopyramide; coadministration with omeprazole may increase plasma levels of both agents

Contraindications

Documented hypersensitivity; coadministration with pimozide

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studies in humans; may use if benefits outweigh risk to fetus

Precautions

Coadministration with ranitidine or bismuth citrate is not recommended with CrCl <25 mL/min; administer half dose or increase dosing interval if CrCl <30 mL/min; irritative diarrhea not due to Clostridium difficile; superinfections may occur with prolonged or repeated antibiotic therapies

Ethambutol (Myambutol)

Standard drug for nontuberculous mycobacterial disease. Diffuses into actively growing mycobacterial cells and impairs cell metabolism by inhibiting synthesis of one or more metabolites, which, in turn, causes cell death. No cross-resistance demonstrated. Mycobacterial resistance is frequent with previous therapy. Use in these patients in combination with second-line drugs that have not previously been administered. Administer qd until permanent bacteriological conversion and maximal clinical improvement is observed. Absorption not significantly altered by food.

Dosing

Adult

15 mg/kg (7 mg/lb) PO qd

Pediatric

<12 years: Not recommended
>12 years: Administer as in adults

Interactions

Aluminum salts may delay and reduce absorption (administer several hours before or after ethambutol dose)

Contraindications

Documented hypersensitivity; optic neuritis (unless clinically indicated)

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Liver disease (only a few cases of liver toxicity have been observed); reduce dose in patients with impaired renal function; may cause adverse visual effects that may be reversible if promptly discontinued; monthly monitoring of visual acuity and color vision is recommended; approximately 1% of ophthalmologic complications occur with doses of 15 mg/kg PO qd; approximately 10% of ophthalmologic complications occur with doses of 25 mg/kg PO qd

Levofloxacin (Levaquin)

May be useful. Aide effects are very rare (eg, GI or CNS abnormalities, tendinitis). For treatment of mycobacterial infection in combination with rifampin and other antituberculosis agents.

Dosing

Adult

500-1000 mg PO qd or divided bid

Pediatric

<12 years: Not established
>12 years: Administer as in adults

Interactions

Antacids, iron salts, and zinc salts may reduce serum levels; administer antacids 2-4 h before or after taking fluoroquinolones; cimetidine may interfere with metabolism; reduces therapeutic effects of phenytoin; probenecid may increase serum concentrations; may increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT)

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studies in humans; may use if benefits outweigh risk to fetus

Precautions

In prolonged therapy, periodically evaluate organ system functions (eg, renal, hepatic, hematopoietic); adjust dose in renal function impairment; superinfections may occur with prolonged or repeated antibiotic therapy

Rifampin (Rifadin, Rimactane)

For use in combination with at least one other antituberculous drug. Inhibits DNA-dependent bacterial but not mammalian RNA polymerase. Cross-resistance may occur. Often used for nontuberculous mycobacterial disease.

Dosing

Adult

600 mg PO qd

Pediatric

10-20 mg/kg PO; not to exceed 600 mg/d

Interactions

Induces microsomal enzymes, which may decrease effects of acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta-blockers, chloramphenicol, oral contraceptives, corticosteroids, mexiletine, cyclosporine, digitoxin, disopyramide, estrogens, hydantoins, methadone, clofibrate, quinidine, dapsone, tazobactam, sulfonylureas, theophyllines, tocainide, and digoxin; blood pressure may increase with coadministration of enalapril; coadministration with isoniazid may result in higher rate of hepatotoxicity than with either agent alone (discontinue one or both agents if alterations in LFT results occur)

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studies in humans; may use if benefits outweigh risk to fetus

Precautions

Obtain CBC counts and baseline clinical chemistry values prior to and throughout therapy; in liver disease, weigh benefits against risk of further liver damage; interruption of therapy and high-dose intermittent therapy are associated with thrombocytopenia that is reversible if therapy is discontinued as soon as purpura occurs; if treatment is continued or resumed after appearance of purpura, cerebral hemorrhage or death may occur

Rifabutin (Mycobutin)

Ansamycin antibiotic derived from rifamycin S. Inhibits DNA-dependent RNA polymerase, preventing chain initiation in susceptible strains of Escherichia coli and Bacillus subtilis but not in mammalian cells. If GI upset occurs, administer dose bid with food. May be more active with nontuberculous species.

Dosing

Adult

300-600 mg PO qd

Pediatric

Not established; 5 mg/kg/d PO suggested

Interactions

Reduce to 150 mg PO qd with coadministration of protease inhibitor (eg, indinavir, nelfinavir); decreases levels of many other medications (eg, estrogens); do not exceed 300 mg qd when used with clarithromycin; steady-state zidovudine plasma levels may decrease after repeated rifabutin dosing, but this does not affect inhibition of HIV by zidovudine

Contraindications

Documented hypersensitivity; uveitis; thrombocytopenia

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Do not administer to patients with active tuberculosis; periodically perform hematologic studies in patients receiving prophylaxis because of association with neutropenia and, more rarely, thrombocytopenia

Azithromycin (Zithromax)

Treats mild-to-moderate microbial infections. Dosing qwk is possible.

Dosing

Adult

10 mg/kg PO on day 1, 5 mg/kg on days 2-5, then 10 mg/kg qwk; 1200 mg PO qwk used in adults

Pediatric

10 mg/kg PO on day 1, 5 mg/kg on days 2-5, then 10 mg/kg qwk

Interactions

May cause QT prolongation with cisapride, itraconazole, sparfloxacin, and other medications (probably very rare); may increase toxicity of theophylline, warfarin, and digoxin; effects are reduced with coadministration of aluminum and/or magnesium antacids; nephrotoxicity and neurotoxicity may occur when coadministered with cyclosporine

Contraindications

Documented hypersensitivity; hepatic impairment; do not administer with pimozide

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Site reactions can occur with IV route; bacterial or fungal overgrowth may result with prolonged antibiotic use; may increase hepatic enzymes and cholestatic jaundice; caution in patients with impaired hepatic function or prolonged QT intervals; caution in patients who are hospitalized, geriatric, or debilitated

Follow-up

Further Inpatient Care

• M gordonae infections should be treated until symptoms resolve. Prolonging treatment may prevent relapse, but the optimal treatment duration is unknown. Three, 6, and 12 months of therapy have been used. The improvement of objective abnormalities (eg, chest radiograph findings) may also be useful in determining the optimal duration of treatment. If the treatment time is too short, relapse may occur. If the treatment time is too long, the adverse effects of medication may become a concern.
• Isolation is not indicated (once active tuberculosis infection is excluded); however, the presence of acid-fast organisms on a stain should prompt immediate isolation unless the patient is clearly not acutely contagious.

Further Outpatient Care

• Treat in an outpatient setting. Evaluate the patient monthly for adverse effects.

Inpatient & Outpatient Medications

• At least 2 daily drugs are indicated for documented M gordonae disease. Intermittent therapy has not been evaluated.

Transfer

• Transfer to other facilities is unnecessary. Consultation with an expert from the National Jewish Medical and Research Center in Denver, Colo; Centers for Disease Control and Prevention in Atlanta, Ga; local infectious disease experts; or the department of health may be useful.

Complications

• Dissemination is a concern. Death is an unlikely outcome, except in patients who are immunocompromised.
• Monotherapy may induce resistance.

Prognosis

• With treatment, the reported prognosis of M gordonae infection is excellent.

Patient Education

• Inform patients that they are not infectious and are not dangerous to other people.

Miscellaneous

Medicolegal Pitfalls

• The only known medical or legal pitfall is misdiagnosing the patient with tuberculosis and any subsequent repercussions. However, if the culture report arrives after discharge, evaluate the patient for possible disease. In most cases, the isolates represent laboratory contamination of submitted specimens.

Special Concerns

• Complications during pregnancy have not been reported.

References

1. Lalande V, Barbut F, Varnerot A, Febvre M, Nesa D, Wadel S, et al. Pseudo-outbreak of Mycobacterium gordonae associated with water from refrigerated fountains. J Hosp Infect. May 2001;48(1):76-9. [Medline].

2. American Thoracic Society. Diagnosis and treatment of disease caused by nontuberculous mycobacteria. This official statement of the American Thoracic Society was approved by the Board of Directors, March 1997. Medical Section of the American Lung Association. Am J Respir Crit Care Med. Aug 1997;156(2 Pt 2):S1-25. [Medline].

3. Jun HJ, Jeon K, Um SW, Kwon OJ, Lee NY, Koh WJ. Nontuberculous mycobacteria isolated during the treatment of pulmonary tuberculosis. Respir Med. Dec 2009;103(12):1936-40. [Medline].

4. Konishi M, Uno K, Kasahara K, Mori K, Yoshimoto E, Maeda K, et al. [A case of pulmonary Mycobacterium gordonae infection progressed for no therapy]. Nihon Kokyuki Gakkai Zasshi. May 2007;45(5):436-40. [Medline].

5. Lessnau KD, Milanese S, Talavera W. Mycobacterium gordonae: a treatable disease in HIV-positive patients. Chest. Dec 1993;104(6):1779-85. [Medline].

6. Sneath PH, Mair NS, Sharpe ME, eds. The Mycobacteria. Genus Mycobacterium. In: Bergey's Manual of Systematic Bacteriology. Vol 2. 2^nd ed. Baltimore, Md: Williams & Wilkins; 1986:1447.

7. Sánchez-Morgado JM, Gallagher A, Johnson LK. Mycobacterium gordonae infection in a colony of African clawed frogs (Xenopus tropicalis). Lab Anim. Jul 2009;43(3):300-3. [Medline].

8. Umeda Y, Matsuno Y, Imaizumi M, Mori Y, Iwata H, Takiya H. Extralobar pulmonary sequestration infected with Mycobacterium gordonae. J Thorac Cardiovasc Surg. Jan 2009;137(1):e23-4. [Medline].

9. Weinberger M, Berg SL, Feuerstein IM, Pizzo PA, Witebsky FG. Disseminated infection with Mycobacterium gordonae: report of a case and critical review of the literature. Clin Infect Dis. Jun 1992;14(6):1229-39. [Medline].

Keywords

tap water bacillus, tap water isolate, tap water bacteremia, nontuberculous mycobacteria, mycobacteria, non-tuberculous mycobacteria

Contributor Information and Disclosures

Author

Klaus-Dieter Lessnau, MD, FCCP, Clinical Associate Professor of Medicine, New York University School of Medicine; Medical Director, Pulmonary Physiology Laboratory; Director of Research in Pulmonary Medicine, Department of Medicine, Section of Pulmonary Medicine, Lenox Hill Hospital
Klaus-Dieter Lessnau, MD, FCCP is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Society for Artificial Internal Organs, American Thoracic Society, Physicians for Social Responsibility, and Society of Critical Care Medicine
Disclosure: sepracor Ownership interest None

Coauthor(s)

Cynthia de Luise, PhD, MPH, Director, Epidemiology, Pfizer, Inc
Cynthia de Luise, PhD, MPH is a member of the following medical societies: American Academy of Physician Assistants, American Public Health Association, and International Society for Pharmacoepidemiology
Disclosure: Pfizer Salary Employment

Medical Editor

Thomas Herchline, MD, Professor of Medicine, Wright State University Boonshoft School of Medicine; Medical Director, Public Health, Dayton and Montgomery County, Ohio
Thomas Herchline, MD is a member of the following medical societies: American College of Physicians, American Society for Microbiology, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Aaron Glatt, MD, Professor of Clinical Medicine, New York Medical College; President and CEO, Former Chief Medical Officer, Departments of Medicine and Infectious Diseases, New Island Hospital
Aaron Glatt, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physician Executives, American College of Physicians, American College of Physicians-American Society of Internal Medicine, American Medical Association, American Society for Microbiology, American Thoracic Society, American Venereal Disease Association, Infectious Diseases Society of America, International AIDS Society, and Society for Healthcare Epidemiology of America
Disclosure: Nothing to disclose.

CME Editor

Eleftherios Mylonakis, MD, Clinical and Research Fellow, Department of Internal Medicine, Division of Infectious Diseases, Massachusetts General Hospital
Eleftherios Mylonakis, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians, American Society for Microbiology, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

Chief Editor

Burke A Cunha, MD, Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital
Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

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