Mycobacteria Other Than Tuberculosis Research Articles

Concomitant HIV and mycobacterial infection in Ireland, 1987-92.

A six-year retrospective review of concomitant HIV and mycobacterial infection in the Republic of Ireland is presented. A total of 42 culture proven mycobacterial infections were seen in 40 different HIV-infected patients. There were 24 infections with Mycobacterium tuberculosis (M.tb) and 18 infections with mycobacteria other than tuberculosis (MOTT), a significantly higher rate of MOTT infections in Ireland compared to a study from 1962-1981. The detection rate for all mycobacterial infections had an annual upward trend with a 4-fold increase between 1987 and 1992. In homosexuals, MOTT infections occurred more frequently than M.tb, while the reverse was true for IVDUs. Twenty per cent of the infections were seen in patients recently incarcerated. Relapse of tuberculosis occurred in 42.9% (3/7) of non-compliant patients, 2 of whom developed rifampin-resistant strains of M.tb. No patient compliant to their regimen had a relapse in disease. The overall survival of patients after diagnosis of M.tb was significantly better than those with MOTT infections, with respective one-year survival rate of 79% and 36% (log rank test, P = 0.006).

The Role of Mycobacteria Other Than Tuberculosis (MOTT) in Patients with Cystic Fibrosis

The purpose of this study was to estimate the frequency of and evaluate the clinical impact of pulmonary mycobacterial infections among cystic fibrosis (CF) patients. 185 CF patients aged 2.2-38.5 years were screened by sputum samples and by intracutaneous skin tests against tuberculin and sensitins produced from Mycobacterium chelonae subsp. abscessus, M. avium, M. intracellulare and M. scrofulaceum (the MAIS complex). The skin tests towards the sensitins in BCG-vaccinated patients (n = 60) were significantly influenced by the vaccination. 26 of the remaining 125 non-vaccinated patients had > or = 1 positive skin test (95% confidence limits 15-29%). The majority reacted against the MAIS complex. However, the reactions were similar to those of healthy siblings and an age-matched control group. Moreover, the lung function, growth and HbA1c were similar among skin test positive and negative patients. Three patients had repeated positive sputum cultures, the point prevalence being 1.6% (M. intracellulare, n = 2 and M. chelonae subsp. abscessus, n = 1). During the subsequent 4 years, 4 additional patients with M. chelonae subsp. abscessus were identified. Based on clinical observations, 5 of the infected patients were considered asymptomatic, while 2 might have been symptomatic. In 1 patient, M. chelonae subsp. abscessus disappeared spontaneously. Despite intensive treatment with new antibiotics against Mycobacteria Other Than Tuberculosis (MOTT) in 4 patients, the mycobacteria were not eradicated. In conclusion, MOTT infection was rare and the clinical impact difficult to prove. Treatment should focus on clinical improvement in the individual patient suspected of suffering from significant symptomatic infection. Eradication of the bacteria should not be expected.

Mycobacteria Other than Tuberculosis Producing Disease in a Tertiary Referral Hospital

Over the period of 1987 to 1989, three hundred and two isolates of ten species of mycobacteria other than tuberculosis (MOTT) produced disease in 282 patients. M. avium intracellulare was the most common (53% patients), followed by M. gordonae and M. fortuitum-chelonae (20%). The most common clinical presentation was of a protracted respiratory infection in 82%. At least one significant associated illness or predisposing factor was present in 83% patients. A significant immunosuppressive state was present in 1117 (45%) patients which included solid tumors, reticuloendothelial malignancies and organ transplant recipients. However, unequivocal florid disease including pneumonia, pericarditis and pericecal mass occurred in several immunocompetent patients. Of 202 patients with brochopulmonary infection, 59 (29%) were found to be concomintantly infected with microorganisms other than MOTT, and in these patients a significant association with acute chest radiographical changes was found, and posed difficulty for deciding the role of MOTT in these patients. In many patients, the illness associated with MOTT was mild, although approximately one-half of patients received an antimicrobial which had some antimycobacterial activity. The clinical spectrum of disease produced by MOTT may be quite broad and a low grade pathogenic role in many patients cannot be excluded.

Surgeons Say Cutting Out Some TB and MOTT May Be the Answer in Multidrug-Resistant Infections

MANY WOMEN with mycobacterial lung infection may be spared years of debilitating illness if physicians treating them can be persuaded to share their care with surgeons, according to a presentation at the American College of Surgeons annual meeting, held in New Orleans, La. Aggressive Approach More aggressive treatment of patients with multidrug-resistant infections must be considered now that Mycobacterium tuberculosis and the related organisms known as atypical tuberculosis or MOTT (mycobacterium other than tuberculosis) are resurgent, says Marvin Pomerantz, MD, chief of the General Thoracic Surgical Service and professor of surgery, University of Colorado School of Medicine, Denver. Among the organisms that cause MOTT are Mycobacterium avium-intracellulare complex, M kansasii, M xenopi, M chelonei , and M malmoense . One form of MOTT disease—isolated infection of the middle lobe and lingula— has been seen so far only in women, says the surgeon, although he says it may someday show up in men

Clinical experience on mycobacterial diseases other than tuberculos- is.

Background: The prevalence of tuberculosis in Korea decreased remarkably for the past 30 years, while for at least the recent 10 years, the frequency of disease attributable to mycobacteria other than tuberculosis (MOTT) began to increase both in actual numbers and in the proportion of the total burden of mycobacterioses. Method: Twenty nine cases, diagnosed as having pulmonary disease due to MOTT on the basis of repeated isolations of the relevant organisms from sputum specimens and chest X-ray findings from Jan. 1982 throught Dec. 1991 at the Chest Clinic of the Korean Institute of Tuberculosis, were reviewed in terms of clinical features and courses. Results: 1) Nineteen cases (66%) were infected with Mycobacterium avium-intracellulare, 5 cases (17%) with M. fortuitum, 4 cases (14%) with M. chelonei, and 1 cases (3%) with M. szulgai. 2) The ratio of male versus female patients was 1.9:1. 3) The peak incidence was in the fifth decade. 4) Eighteen cases (62%) had moderately advanced disease and 11 cases (38%) had far advanced disease on chest P-A film. 5) The common symptoms were cough (59%), sputum (52%), and dyspnea (34%). 6) All cases had a previous history of tuberculosis. 7) Most of the isolates were highly resistant to the major antituberculosis drugs and 48~52% showed a sensitivity to cycloserine, kanamycin or enviomycin. 8) Of 19 cases which were treated and followed-up for over 12 months, 3 cases attained negative conversion on cultures (2 M. fortuitum infections, 1 M. szulgai infection). Sixteen cases failed in attaining negative conversion on cultures. However, their clinical courses were chronic and indolent despite of persistant culture positivity. Conclusion: Treatment of these patients has been difficult because of the frequency of severe underlying conditions and the natural resistance of most of the nontuberculous mycobacteria to the presently available drugs.

Nontuberculous Mycobacteria in Adult Patients with Cystic Fibrosis

Because patients with cystic fibrosis (CF) may be predisposed to airway infections with unusual microorganisms, we screened the sputum of adult CF patients for mycobacterial organisms. Acid-fast bacilli (AFB) smears and mycobacterial culture were performed on 297 sputum specimens from 87 patients. Cultures for mycobacteria were frequently overgrown with other bacteria; 22.6 percent of cultures were contaminated. Despite this limitation of mycobacterial culture, 17 patients had at least one positive culture for a Mycobacterium other than tuberculosis (MOTT). Eleven patients were positive for Mycobacterium avium-intracellulare (MAI), two for MAI and M chelonei, three for M chelonei, and one for M fortuitum. None was positive for M tuberculosis. Patients with CF with MOTT were similar to patients with CF without MOTT; only a slightly different (older) age distribution was recognized. The clinical significance of MOTT was difficult to determine in any individual patient, but patients with positive AFB smears appeared more likely to suffer pathogenic effects. We conclude that MOTT is frequently recovered from adult CF patients in the southeastern United States. A specific risk factor for colonization and/or pathogenic infection in this patient group was not evident. The general prevalence and clinical pathogenesis in CF patients in the United States remains to be determined.

Tuberculosis in the west of Ireland 1986-1990.

A review of mycobacteria isolated from clinical samples from the Western Health Board Area (WHBA) for the years 1986 to 1990 was performed to establish the pattern of mycobacterial infection. The incidence of microbiologically proven cases of tuberculosis (13.3/100,000) and of sputum smear positive cases (6.2/100,000) was determined and correlated with notification data. M. bovis accounts for 6.3% of cases of microbiologically confirmed tuberculosis in this area. Resistance to one or more of the first line anti-tuberculous drugs was noted in 5.3% of isolates (excluding pyrazinamide resistance in M. bovis). Clinically significant isolates of mycobacteria other than tuberculosis (MOTT) were rare throughout the five year period. The overall incidence of microbiologically proven cases of tuberculosis is relatively high and M. bovis and drug resistant isolates of M. tuberculosis are relatively common.

Influence of bronchoscopic examinations on the statistics of tuberculosis incidence

The frequency of the modes of bacteriological examinations other than direct sputum smear were observed for a total of 955 "smear-positive" pulmonary tuberculosis cases which were notified at 7 health centres in the Metropolitan and suburban areas during 1986-1990. Of them 21 cases (2.2%) were examined for the specimens obtained by bronchofiberscopic procedures, and in 4 cases (0.4%) gastric juice was taken. The proportion of the non-sputum positivity as seen above was higher in females than in males, but it was uniform across all age group. Non-cavitary cases showed higher proportion of the non-sputum positivity than cavitary cases. There was wide variation in the frequency of these aggressive modes of examination among health centres, probably indicating the difference in the extent to which hospitals are interested in these modes of examination in each health center area. In addition to the above observed cases, there were 60 cases with direct smear positive finding of mycobacteria other than tuberculosis (MOTT). They account for 5.9% of all of 1,015 new notifications of AFB-smear positive cases. It is possible that these non-sputum "smear positive" cases, as well as the MOTT-smear positive cases may be underestimated in our study, because of the notification form not necessarily requesting to enter the type of bacteriological examinations. They may contribute to the recent upward trend of incidence rate of smear positive tuberculosis in Japan to a considerable extent.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of improved BACTEC and Lowenstein-Jensen media for culture of mycobacteria from clinical specimens

A 4-month trial involving 2,563 routine clinical specimens was conducted to compare the improved BACTEC TB system (12B medium) with the conventional Lowenstein-Jensen (LJ) media for the isolation, identification, and susceptibility testing of mycobacteria. One hundred sixty-two mycobacterial isolates were recovered, 147 (91%) with BACTEC and 118 (73%) with LJ media. Of these, 62 were Mycobacterium tuberculosis complex strains, 59 (95%) of which were isolated with BACTEC and 54 (87%) of which were isolated with LJ media. Of the remaining 100 isolates, which were mycobacteria other than tuberculosis (MOTT), BACTEC and LJ media detected 88 and 64%, respectively. The contamination rate was significantly higher in BACTEC (5%) than in LJ media (3.3%). The mean isolation time for M. tuberculosis complex with BACTEC was 15.5 days, compared with 25.6 days with LJ. For MOTT, the mean isolation times were 5.8 and 21.4 days, respectively. Identification of 32 M. tuberculosis complex isolates and 38 isolates of MOTT by the BACTEC NAP (p-nitro-alpha-acetylamino-beta-hydroxypropiophenone) inhibition test gave 100% agreement with conventional biochemical identifications. The results of susceptibility testing of 18 M. tuberculosis complex isolates with BACTEC agreed completely with those obtained by the resistance ratio method.

DNA probes for mycobacteria. I. Isolation of DNA probes for the identification of Mycobacterium tuberculosis complex and for mycobacteria other than tuberculosis (MOTT).

Traditional methods used in identifying mycobacteria such as acid-fast bacillus stains and culture are often time-consuming, insensitive and non-specific. The isolation of DNA probes, coupled to a non-radioactive, e.g. biotin-based detection system, have the potential to foster the development of clinical assays for Mycobacterium tuberculosis and mycobacteria other than tuberculosis (MOTT) that are rapid, sensitive and specific. To this end, we have isolated two different probes: one which is specific for the Mtb complex and one which recognizes all other potentially pathogenic mycobacteria. The use of these probes in combination should allow the detection and differentiation of M. tuberculosis from MOTT. To isolate the first probe, we prepared a library of M. tuberculosis DNA fragments in a lambda EMBL phage vector. Recombinant phage were screened by plaque-lift hybridization procedures using nick-translated mycobacterial genomic DNA to identify sequences specific to the Mtb complex. Inserts from candidate recombinant phage were purified, nick-translated and hybridized against a wide variety of filter-bound mycobacterial and non-mycobacterial DNAs. Two clones were identified which hybridized to the closely related M. tuberculosis, M. bovis and M. microti but not to other species of mycobacteria. The second probe was isolated by preparing a library of M. malmoense DNA fragments in lambda EMBL and screening by plaque-lift hybridization. One clone was identified which, in addition to recognizing members of the Mtb complex, also hybridized to M. intracellulare, M. malmoense, M. scrofulaceum, M. simiae, M. xenopi, M. avium, M. szulgai, M. kansasii and M. haemophilum. None of the three clones hybridized to DNA from non-mycobacterial species.

Mycobacteria other than tuberculosis. Pulmonary involvement in patients with acquired immunodeficiency syndrome.

A normal host can be colonized by mycobacteria other than tuberculosis (MOTT), resulting in bronchoscopic isolates of no clinical significance. In the acquired immunodeficiency syndrome (AIDS), Mycobacterium avium-intracellulare, Mycobacterium kansasii, and Mycobacterium xenopi have caused widely disseminated infection. To determine the usefulness of fiberoptic bronchoscopy (FB) in evaluating MOTT infection in AIDS, we reviewed MOTT cultures from 36 FBs, correlated these to clinical course, and identified MOTT isolates from cultures of all other sources in these patients. Of ten bronchoscopic MOTT isolates, seven were not related to lung disease or to dissemination within one month of FB. Of the four Mycobacterium fortuitum and seven M avium-intracellulare that did disseminate within one month, only two were reflected in bronchoscopic cultures. In patients with AIDS, bronchopulmonary MOTT colonization does occur. We recommend that standard criteria for pulmonary mycobacterial disease be applied. Negative bronchopulmonary cultures do not seem to exclude dissemination.

Mycobacteria Other Than Tuberculosis

• A normal host can be colonized by mycobacteria other than tuberculosis (MOTT), resulting in bronchoscopic isolates of no clinical significance. In the acquired immunodeficiency syndrome (AIDS),<i>Mycobacterium avium-intracellulare, Mycobacterium kansasii</i>, and<i>Mycobacterium xenopi</i>have caused widely disseminated infection. To determine the usefulness of fiberoptic bronchoscopy (FB) in evaluating MOTT infection in AIDS, we reviewed MOTT cultures from 36 FBs, correlated these to clinical course, and identified MOTT isolates from cultures of all other sources in these patients. Of ten bronchoscopic MOTT isolates, seven were not related to lung disease or to dissemination within one month of FB. Of the four<i>Mycobacterium fortuitum</i>and seven<i>M avium-intracellulare</i>that did disseminate within one month, only two were reflected in bronchoscopic cultures. In patients with AIDS, bronchopulmonary MOTT colonization does occur. We recommend that standard criteria for pulmonary mycobacterial disease be applied. Negative bronchopulmonary cultures do not seem to exclude dissemination. (<i>Arch Intern Med</i>1988;148:953-955)

Identifying Mycobacterium tuberculosis cultures by gas-liquid chromatography and a computer-aided pattern recognition model

A procedure that uses gas-liquid chromatography and a pattern recognition computer model was developed for distinguishing cultures of Mycobacterium tuberculosis from cultures of other mycobacteria, common bacteria, and fungi. In this procedure, a sample of a culture preparation is methanolyzed and trimethylsilylated sequentially and injected into a gas chromatograph equipped with a flame ionization detector. A pattern recognition procedure computes an error score by comparing the gas-liquid chromatography peak responses of a culture to those of a standard M. tuberculosis culture. Ten M. tuberculosis cultures were used in the development of the pattern recognition model. Computed error scores of 5 or less were established for identifying an M. tuberculosis culture. The method was evaluated with two sets of test samples, non-M. tuberculosis and M. tuberculosis cultures. Sample identification was correct for all 14 M. tuberculosis cultures (M. tuberculosis or non-M. tuberculosis), 45 fungal cultures, 94 bacterial cultures, and all but 1 of 18 cultures of mycobacteria other than tuberculosis (MOTT). The false prediction represented an isolate of M. fortuitum. For M. tuberculosis, fungal, bacterial, and MOTT cultures, the ranges of error scores were 1 to 5, 16 to 33, 13 to 34, and 4 to 26, respectively. Therefore, we have demonstrated that this diagnostic model can distinguish M. tuberculosis from non-M. tuberculosis cultures with a high degree of accuracy.

A ten-year experience with fiberoptic bronchoscopy for mycobacterial isolation. Impact of the Bactec system.

From January 1974 to December 1983, positive mycobacterial isolates from all sources were reviewed to determine the impact of fiberoptic bronchoscopy (FB) on retrieval and identification of these organisms. There were 112 patients with positive cultures obtained during FB, 25 with Mycobacterium tuberculosis and 87 with mycobacteria other than tuberculosis (MOTT). We reviewed the results of prebronchoscopy and postbronchoscopy sputum specimens, bronchial washings, brushings, and transbronchial biopsy to determine the yield from each specimen in patients with M. tuberculosis. The bronchial washings provided positive cultures in 24 of 25 and were exclusively positive in 10 of 25 (40%). We also reviewed the clinical presentation, chest roentgenogram, bronchoscopy findings, and culture data for the 87 patients with MOTT isolated. The isolation of MOTT from bronchoscopy specimens increased throughout the study, most notably with the introduction of a rapid radiometric method (the Bactec system) for the recovery of mycobacteria to our laboratory in June 1983. Active disease could be established in only 13 of 87 cases (15%). Our findings confirm the sensitivity of Bactec in the isolation of MOTT from bronchoscopic specimens. The Bactec system, on the other hand, does not differentiate saprophytic colonization from clinical disease. To avoid expensive, time-consuming biochemical identification necessary to evaluate these MOTT isolates, careful selection of patients prior to obtaining mycobacterial cultures during FB is a critical factor.