Post-surgical outcome of 57 patients with Mycobacterium xenopi pulmonary infection

Pulmonary disease caused by Mycobacterium xenopi: the first case in Korea

Mycobacterium xenopi is a nontuberculous mycobacterium (NTM) that rarely causes pulmonary disease in Asia. Here we describe the first case of M. xenopi pulmonary disease in Korea. A 66-year-old man was admitted to our hospital with a 2-month history of productive cough and hemoptysis. His past medical history included pulmonary tuberculosis 44 years earlier, leading to a right upper lobectomy. Chest X-ray upon admission revealed cavitary consolidation involving the entire right lung. Numerous acid-fast bacilli were seen in his initial sputum, and M. xenopi was subsequently identified in more than five sputum cultures, using molecular methods. Despite treatment with clarithromycin, rifampicin, ethambutol, and streptomycin, the infiltrative shadow revealed on chest X-ray increased in size. The patient's condition worsened, and a right completion pneumonectomy was performed. The patient consequently died of respiratory failure on postoperative day 47, secondary to the development of a late bronchopleural fistula. This case serves as a reminder to clinicians that the incidence of NTM infection is increasing in Korea and that unusual NTM are capable of causing disease in non-immunocompromised patients.

[Pulmonary infections with Mycobacterium xenopi in patients without HIV infection]

OBJECTIVE

To determine the incidence, clinical characteristics, microbiological features and outcome of Mycobacterium xenopi infections in patients attending a university hospital.

METHODS

We reviewed the files of HIV-seronegative patients meeting ATS criteria for M. xenopi pulmonary infection between 1993 and 2004.

RESULTS

Ten patients were studied (7 men, 60+/-27 years). All but one had underlying chronic health disorders (chronic lung disease, cancer, alcoholism, systemic steroid therapy). The clinical and radiological findings were those associated with tuberculosis. Acid-fast bacilli were detected by direct examination in 9 cases, and antituberculous treatment prescribed in 8 patients. Specific treatment was started an average of 60+/-25 days after sampling, and generally combined a fluoroquinolone, clarithromycin and rifampicin, with or without ethambutol, for a mean of 11.4 months (1-37 months). Five patients had surgical excision (diagnostic in 1 case). Four patients died of their underlying disease. Two patients recovered with antibiotics alone and three with antibiotics and surgery. One patient was lost to follow-up after five months.

CONCLUSION

Pulmonary infection by M. xenopi is rare in HIV-seronegative patients. The prognosis depends mainly on the patient's underlying health status. Surgery is an important component of treatment.

[Exclusive surgical treatment of Mycobacterium xenopi infection of a pulmonary cavity]

The diagnosis of pulmonary infection due to Mycobacterium xenopi was retained in a 48-year-old immunocompetent patient. The lesion was isolated in a peripheral region and was well limited. Exclusive surgical treatment was undertaken. Cure was complete without recurrence at three years. This case illustrates that in certain cases environmental mycobacteriosis with a very limited lesion may respond very well to surgical resection, an interesting alternative to medication.

Human immunodeficiency virus type 1-related pulmonary Mycobacterium xenopi infection: a need to treat?

We report treatment decisions and outcomes for 20 patients who were infected with human immunodeficiency virus type 1 (HIV-1) and were receiving highly active antiretroviral therapy (HAART) who had respiratory symptoms and from whom Mycobacterium xenopi was isolated. All patients also had coexisting pulmonary pathologic conditions. The median blood T cell CD4 count was 37 cells/microL (range, 2-480 cells/microL). Fifteen of 20 patients received no antimycobacterial therapy and remain healthy after a median of approximately 4 years of follow-up, and 2 patients required treatment specifically for M. xenopi infection, both showing clinical improvement. We conclude that pulmonary M. xenopi isolation in HIV-1 patients receiving HAART does not usually require specific treatment.

Pulmonary resection for Mycobacterium xenopi pulmonary infection

BACKGROUND

Results of medical therapy for Mycobacterium xenopi pulmonary infection remain unreliable. Pulmonary resection may be beneficial to patients whose disease is localized and who can tolerate a resectional operation.

METHODS

Eighteen patients underwent pulmonary resection between 1991 and 2000: 14 men and 4 women, with a mean age of 50 +/- 12 years (range 27 to 68 years). Indications for operation were either therapeutic (n = 9) or diagnostic (n = 9). Four patients received antimycobacterial chemotherapy before their operation and 2 patients were HIV positive.

RESULTS

Therapeutic procedures included completion pneumonectomy (n = 1), lobectomy (n = 6), segmentectomy (n = 1), and bilateral wedge resection (n = 1). Diagnostic procedures included lobectomy (n = 1) and wedge resection (n = 8). Complete resection could be achieved in 15 patients (83%). There was no in-hospital mortality. Postoperative complications included prolonged air leak (5 of 18 patients, 27.7%) and pleural effusion requiring insertion of a new chest tube (3 of 18 patients, 16.6%). Mean hospital stay was 14 +/- 8 days. Follow-up was 100% complete. Eleven patients received antimycobacterial chemotherapy for 4 to 24 months, postoperatively. Late mortality was 11% and was unrelated to progression of mycobacterial disease. After the operation, the sputum remained positive in only 2 patients (11%) with incomplete resections. Fourteen patients were asymptomatic with no relapse at a mean follow-up of 38 +/- 22 months (range 85 to 13 months).

CONCLUSIONS

Resection represents an important adjunct to chemotherapy for the treatment of M. xenopi pulmonary disease. In the setting of localized nodular or cavitary disease, failure to respond to medical therapy, relapse after treatment discontinuation, coexistent aspergilloma or polymicrobial contamination, or patient intolerance of medical therapy, pulmonary resection can be undertaken with acceptable morbidity and mortality.

Performance assessment of new multiplex probe assay for identification of mycobacteria

A new DNA probe assay (INNO LiPA Mycobacteria; Innogenetics, Ghent, Belgium) for the simultaneous identification, by means of reverse hybridization and line-probe technology, of Mycobacterium tuberculosis complex, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium gordonae, the species of the Mycobacterium avium complex (MAC), Mycobacterium scrofulaceum, and Mycobacterium chelonae was evaluated on a panel of 238 strains including, besides representatives of all the taxa identifiable by the system, a number of other mycobacteria, some of which are known to be problematic with the only other commercial DNA probe system (AccuProbe; Gen-Probe, San Diego, Calif.), and two nocardiae. The new kit, which includes a control probe reacting with the whole genus Mycobacterium, correctly identified 99.6% of the strains tested; the one discrepancy, which remained unresolved, concerned an isolate identified as MAC intermediate by INNO LiPA Mycobacteria and as Mycobacterium intracellulare by AccuProbe. In five cases, because of an imperfect checking of hybridization temperature, a very slight, nonspecific, line was visible which was no longer evident when the test was repeated. Two strains whose DNA failed amplification at the first attempt were regularly identified when the test was repeated. Interestingly, the novel kit dodged all the pitfalls presented by the strains giving anomalous reactions with AccuProbe. A unique feature of INNO LiPA Mycobacteria is its ability to recognize different subgroups within the species M. kansasii and M. chelonae, while the declared overlapping reactivity of probe 4 with some M. kansasii and Mycobacterium gastri organisms and of probe 9 with MAC, Mycobacterium haemophilum, and Mycobacterium malmoense, may furnish a useful aid for their identification. The turnaround time of the method is approximately 6 h, including a preliminary PCR amplification.

Increasing incidence of Mycobacterium xenopi at Bellevue hospital: An emerging pathogen or a product of improved laboratory methods?

STUDY OBJECTIVES

To investigate the dramatic rise in number of Mycobacterium xenopi isolates identified in our mycobacteriology laboratory, and to determine if this increase was due to emerging clinical pathology or to changes in culture technique.

DESIGN

Retrospective chart and laboratory review.

SETTING

University-affiliated tertiary-care city hospital.

PATIENTS

Eighty-one patients with a single culture positive for M xenopi from 1975 to 1994 (period 1), and 47 patients with two or more cultures positive from 1994 to 1998 (period 2).

INTERVENTIONS

The Bellevue mycobacteriology laboratory changed the culture medium from solid Lowenstein-Jensen medium (used from 1975 to 1990) to the Septi-Check AFB System (Becton-Dickinson; Glencoe, MD; used from 1991 to 1994), to the Mycobacteria Growth Indication Tube (MGIT; Becton-Dickinson; used from 1995 to 1998).

MEASUREMENTS AND RESULTS

We recovered 29 M xenopi isolates from 1975 to 1990, 12 isolates from 1991 to 1994, and 381 isolates from 1995 to 1998. We subsequently identified and reviewed the medical records of all 81 patients who were culture positive for M xenopi from 1975 to 1994 (period 1), and 46 patients who had two or more isolates culture positive for M xenopi from 1995 to 1998 (period 2). For period 1, 75% of the subjects were male, 80% were minority, and at least 43% were HIV positive. Only one patient had clinical M xenopi lung disease during this period. For period 2, 79% of the subjects were male, 83% were minority, and at least 58% were HIV positive; two additional patients were identified who had clinical M xenopi lung disease.

CONCLUSIONS

The dramatic increase in M xenopi isolates noted in our hospital was due to a more sensitive laboratory isolation technique, rather than a true increase in clinical disease. Other hospitals utilizing MGIT systems for mycobacterial recovery should interpret positive M xenopi cultures with caution.

Preliminary results of collapse therapy with plombage for pulmonary disease caused by multidrug-resistant mycobacteria

Seven patients underwent collapse therapy with polystyrene sphere plombage for pulmonary disease caused by multidrug-resistant mycobacteria. Four patients were infected with multidrug-resistant strains of Mycobacterium tuberculosis, two with Mycobacterium xenopi, one with Mycobacterium avium. All patients were heavily pretreated before surgery, had extensive, bilateral cavitary disease and were considered unsuitable for resection because of extensive disease or functional respiratory impairment. Six patients had active disease at time of surgery. Collapse therapy with insertion of six to 18 spheres resulted in long-standing bacteriological conversion in six patients. Collapse therapy was unilateral in six and bilateral in one. No immediate postoperative complication or death was observed. Hospital stay was short (mean 12 d). Collapse therapy is a conservative alternative therapy in patients with pulmonary disease caused by multidrug-resistant mycobacteria at high risk of treatment failure considered unsuitable for pulmonary resection.

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

Diagnostic criteria of nontuberculous mycobacterial lung disease in HIV-seropositive and -seronegative hosts. The following criteria apply to symptomatic patients with infiltrate, nodular or cavitary disease, or a high resolution computed tomography scan that shows multifocal bronchiectasis and/or multiple small nodules. A. If three sputum/bronchial wash results are available from the previous 12 mo: 1. three positive cultures with negative AFB smear results or 2. two positive cultures and one positive AFB smear B. If only one bronchial wash is available: 1. positive culture with a 2+, 3+, or 4+ AFB smear or 2+, 3+, or 4+ growth on solid media C. If sputum/bronchial wash evaluations are nondiagnostic or another disease cannot be excluded: 1. transbronchial or lung biopsy yielding a NTM or 2. biopsy showing mycobacterial histopathologic features (granulomatous inflammation and/or AFB) and one or more sputums or bronchial washings are positive for an NTM even in low numbers.

COMMENTS

these criteria fit best with M. avium complex, M. abscessus, and M. kansasii. Too little is known of other NTM to be certain how applicable these criteria will be. At least three respiratory samples should be evaluated from each patient. Other reasonable causes for the disease should be excluded. Expert consultation should be sought when diagnostic difficulties are encountered.

Results of surgical treatment of 107 patients with complications of pulmonary tuberculosis

The objective of this study was to evaluate the results of surgical intervention performed on 107 patients with pulmonary tuberculosis complications. Between September 1988 and December 1995, 107 patients underwent a total of 126 operations for major complications of pulmonary tuberculosis. One hundred and twenty-six operations consisted of lobectomies only or plus other lung resections performed in 55 cases, pneumonectomies in 20 cases, segmentectomies in 18 cases, wedge resections in two cases, tracheobronchoplasties in four cases, decortications in two cases, cavernostomies with concomitant muscle transpositions in seven cases, thoracoplasties reserved for the previously failed operations or to be a supplement for pulmonary resections in 18 cases. The operative mortality rate was of 1.8%, and the major complication rate was of 16.8%. Twenty-eight (26.1%) patients with tuberculosis bacilli in sputum before operation have converted except one diabetic patient. In conclusion, surgery is indicated in pulmonary tuberculosis complications that are life-threatening or unresponsive to chemotherapy. Pulmonary resection is the procedure of choice for most cases that require surgery.

Laboratory and clinical evaluation of Mycobacterium xenopi isolates

Mycobacterium xenopi and Mycobacterium avium complex (MAC) are biochemically similar. To define the laboratory characteristics of M. xenopi that distinguish it from MAC, 53 M. xenopi isolates from different areas in the United States and 47 isolates recovered at one hospital were evaluated by 13 biochemical tests, AccuProbe MAC (Gen-Probe, Inc., San Diego, CA, USA), colony morphology, formation of X-colonies, pigmentation in response to light, growth on MacConkey agar without crystal violet, and relative growth rates at 25 degrees C, 36 degrees C, and 45 degrees C on solid media. Relative growth rates of 10 M. xenopi and 11 MAC isolates were measured at 25 degrees C, 36 degrees C, and 42 degrees C in Middlebrook broth processed using the BACTEC TB System. Ten M. xenopi were tested for p-nitro-alpha-acetylamino-beta-hydroxypropiophenone inhibition at 36 degrees C and 42 degrees C. Reevaluation of 81 isolates previously identified as MAC by biochemical tests alone revealed that two were M. xenopi. The most reliable characteristics distinguishing M. xenopi from MAC were the presence of X-colonies (M. xenopi 97% vs MAC 1%), positive 3-day arylsulfatase (M. xenopi 88% vs MAC 1%), growth at 25 degrees C (M. xenopi 0% vs MAC 100%), and AccuProbe MAC test results (M. xenopi 0% hybridized). Retrospective chart review of 37 patients using American Thoracic Society criteria revealed that six (16%) patients had clinically important isolates. At one of our hospitals M. xenopi was the second most common mycobacterial species isolated for 1990-1992, accounting for 27% of all isolates, whereas at our other hospital it accounted for 1% of isolates.(ABSTRACT TRUNCATED AT 250 WORDS)

New macrolide antibiotics: usefulness in infections caused by mycobacteria other than Mycobacterium tuberculosis

OBJECTIVE

To compare the pharmacology, in vitro activity, and clinical use of the new macrolide antibiotics, azithromycin and clarithromycin, in the treatment of infections caused by mycobacteria other than Mycobacterium tuberculosis.

DATA IDENTIFICATION

An English-language literature search using MEDLINE (1987-1994), Index Medicus (1987-1994), Program and abstracts of the 31st (1991) and 32nd (1992) Interscience Conference on Antimicrobial Agents and Chemotherapy, and bibliographic reviews of related textbooks, review articles, and professional society publications.

STUDY SELECTION

105 articles were selected. In vitro and in vivo reports on the pharmacokinetics, microbiology, pharmacology, and effectiveness of clarithromycin and azithromycin were assessed to compare their effectiveness and safety. Emphasis was placed on the use of these new drugs in treating infections caused by Mycobacterium avium complex, Mycobacterium chelonae, and Mycobacterium fortuitum infections.

RESULTS

A review of the in vitro activity of the new macrolides revealed moderate to very good activity against many strains of mycobacteria other than M. tuberculosis. Early clinical trials show promising results in pulmonary infections, lymphadenitis, cutaneous infections, and disseminated infections.

CONCLUSIONS

The new macrolides, azithromycin and clarithromycin, show great promise for treating infections caused by these acid-fast bacteria. Clarithromycin is recommended as a component of combination therapy for the treatment of M. avium complex infections in patients with AIDS. The development of resistance in patients, particularly when these agents are used alone, has been reported.

Activities of pefloxacin and ofloxacin against mycobacteria: in vitro and mouse experiments

The minimal inhibitory concentrations for 90% of strains (MIC90) of ofloxacin against Mycobacterium tuberculosis and Mycobacterium xenopi was 2 mg/l. This was three dilutions lower than that of pefloxacin and was well within the range of drug concentrations achievable in man. The antituberculosis activities of both quinolones were independent of resistance of the strains to other antimycobacterial agents. Mycobacterium avium-intracellulare was resistant to both compounds with MIC90s greater than 16 mg/l. The maximum serum levels (Cmax) of both compounds increased proportionally with increasing dose size. The terminal elimination half-life (T1/2) of pefloxacin was longer than that of ofloxacin, but the T1/2 of both compounds in mice were much shorter than in man. The area under the concentration curve (AUC) of pefloxacin was double than that of ofloxacin. In the mouse, pefloxacin at doses up to 150 mg/kg daily was inactive against M. tuberculosis infection: in terms of survival rate the minimal effective dose of ofloxacin against M. tuberculosis infection was 150 mg/kg daily when given by gavage or by incorporation into the mouse diet at a concentration of 0.1%, but in terms of cfu counts, ofloxacin 150 mg/kg daily only displayed a moderate degree of activity similar to ethambutol 100 mg/kg daily. The therapeutic effects of ofloxacin against M. tuberculosis infection were dose-related: 300 mg/kg daily by gavage or 0.4% in mouse diet displayed much better therapeutic effects than lower dosages. Since the AUC in mice treated with ofloxacin 150 mg/kg daily is close to that in man treated with a clinically tolerated dose--600 mg daily--such a dosage may be only moderately effective against human tuberculosis.

Immunologic consequences of acute ethanol ingestion in rats

Acute ethanol (EtOH) intoxication is commonly associated with many medical and surgical problems which primarily or secondarily involve infection. Chronic EtOH ingestion has been associated with immune dysfunction and an increased risk of infection; however, the relationship of acute EtOH exposure and immune function has not been clearly defined. To determine if there is a relationship between acute EtOH intoxication and immune function, the effects of a single EtOH ingestion on immune function were studied in a rat model. Acute intoxication was produced by gavage feeding of 3 g/kg of EtOH, and immune function was evaluated by in vivo chemotaxis to a chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine and responsiveness of splenic lymphocytes to B- and T-cell mitogens. Chemotaxis was significantly suppressed at 4 hr (49.0 +/- 5.1% of control) after EtOH ingestion (P = 0.001), but returned to normal by 24 hr and remained at that level. However, acute EtOH ingestion showed no suppressive effects on lymphocyte responsiveness to either concanavalin A or LPS. These results indicate that a single ingestion of EtOH has the potential to transiently suppress chemotactic function of granulocytes but not affect lymphocyte mitogenic responsiveness in rats. This potential may contribute to increased susceptibility to infection in patients after EtOH ingestion.