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Introduction: The Mycobacterium chelonae species and the M. avium and M. abscessus complexes are emerging pathogens that cause mycobacteriosis. Treatment depends on the species and subspecies identified. The drugs of choice are macrolides and aminoglycosides. However, due to the resistance identified to these drugs, determining the microbe’s sensitivity profile will allow clinicians to improve the understanding of the prognosis and evolution of these pathologies., Objective: To describe the macrolide and aminoglycoside susceptibility profile of cultures identified by Colombia’s Laboratorio Nacional de Referencia de Mycobacteria from 2018 to 2022, as Mycobacterium avium complex, M. abscessus complex, and M. chelonae. Materials and methods. This descriptive study exposes the susceptibility profile to macrolides and aminoglycosides of cultures identified as M. avium complex, M. abscessus complex, and M. chelonae using the GenoType® NTM-DR method., Materials and Methods: This descriptive study exposes the susceptibility profile to macrolides and aminoglycosides of cultures identified as M. avium complex, M. abscessus complex, and M. chelonae using the GenoType® NTM-DR method., Results: We identified 159 (47.3 %) cultures as M. avium complex, of which 154 (96.9 %) were sensitive to macrolides, and 5 (3.1 %) were resistant; all were sensitive to aminoglycosides. From the 125 (37.2 %) cultures identified as M. abscessus complex, 68 (54.4 %) were sensitive to macrolides, 57 (45.6 %) were resistant to aminoglycosides, and just one (0.8 %) showed resistance to aminoglycosides. The 52 cultures (15.5 %) identified as M. chelonae were sensitive to macrolides and aminoglycosides., Conclusions: The three studied species of mycobacteria have the least resistance to Amikacin. Subspecies identification and their susceptibility profiles allow the establishment of appropriate treatment schemes, especially against M. abscessus.

Mycobacterium chimaera (M. chimaera) is a non-tuberculous mycobacterium of the Mycobacterium avium complex. Between 2013 and April 2018, more than 140 cases of severe infection have been identified, all of them in patients who had undergone cardiothoracic surgery with extracorporeal circulation. The epidemiological investigations have shown that the majority of infections have a common source: contaminated normo-hypothermia modules. These devices have a water circuit inside and cooling fans that produce an aerosol, which can be contaminated with M. chimaera, and disperse it into the air in the operating room. The clinical symptoms can take months, even years to appear after the extracorporeal surgery, with an average of 1.5 years. Sarcoidosis is the most frequently described entity as a misdiagnosis in these patients, so it is necessary to maintain a high diagnostic suspicion in all patients with a history of cardiac surgery with extracorporeal circulation., (Copyright © 2018 Elsevier España, S.L.U. All rights reserved.)

Objective: The aim of this study is to differentially identify MAC by PCR in patients with AIDS and disseminated mycobacteriosis., Methods: A cross sectional study was conducted in Mexico to identify MAC by Molecular Biology. Two sets of primers were synthesized: MAV and MIN, for M. avium and M. intracellulare, respectively. Whole-cell DNAs obtained from 29 clinical isolates and clinical serum specimens from other 24 patients with AIDS and disseminated mycobacterial infection were extracted and amplified by PCR with the MAV and MIN primers. The MAV and MIN primers each amplified one highly specific 1.3-kb segment of the homologous DNA, respectively., Results: Twenty-nine DNAs from MAC clinical isolates identified by Gen-Probe AccuProbes were amplified with the MAV primers. Of the 24 clinical samples, 3 were positive for M. avium and 6 for M. tuberculosis., Conclusions: Our results demonstrated that PCR technique could be applied for the differentiation of M. avium and M. intracellulare by specific 16S rRNA primers. In patients with advanced stage AIDS and in whom disseminated mycobacteriosis is suspected, the presence of anemia (even with negative cultures), elevated alkaline phosphatase and a median CD4 count of 15.9/mL, the diagnosis of infection by MAC should be strongly considered; we suggest that in accordance with our findings, a more precise stratification of patients in terms of their CD4 T cell counts is warranted.

Objective: To describe the clinical, functional and radiographic differences of respiratory disease caused by environmental mycobacteria (EM) in patients with and without silicosis., Method: Retrospective, observational study in patients with nontuberculous mycobacteria isolated in the Hospital Meixoeiro (University Hospital of Vigo) microbiology laboratory between January 2007 and December 2013. Patients were grouped according to the presence or absence of silicosis and mycobacterial lung disease, using American Thoracic Society criteria., Results: In 156 cases, at least one species of EM had been isolated from the respiratory culture. A total of 71% were identified in men, 40 (25.6%) of whom had silicosis. Sixty patients (38.5%) met American Thoracic Society microbiological criteria: 62.5% of the silicosis group and 30.2% of the non-silicosis group. The most common species were Mycobacterium avium complex, Mycobacterium genavense and Mycobacterium chelonae. American Thoracic Society criteria for environmental mycobacterial disease were met in 34 (22.7%) patients: 14 in the silicosis group and 20 in the non-silicosis group. Treatment was administered in 24 cases, with better bacteriological eradication levels in the non-silicosis group., Conclusions: In our series, a history of silicosis was related with a higher incidence of environmental mycobacterial disease. The causative species in the majority of cases in our setting was Mycobacterium avium complex, followed by Mycobacterium genavense. Patients with silicosis showed lower cure rates after treatment., (Copyright © 2015 SEPAR. Published by Elsevier Espana. All rights reserved.)

Pulmonary disease due to nontuberculous myco bacteria is a well known clinical entity, being Mycobacterium avium complex the pathogen most frequently involved. The Lady Windermere syndrome is a variation of this disease, as interesting as it is little known.

Pulmonary disease, due to Mycobacteria other than tuberculosis, is mainly suspected in HIV + patients, or underlying other diseases. In our country, there is no updated information on the prevalence of this pulmonary disease, its treatment and evolution in immucocompetent patients. We present 10 cases of pulmonary disease due to Mycobacteria other than tuberculosis in non HIV patients: clinical-bacteriological diagnosis, treatment and evolution.

One thousand-forty blood cultures corresponding to 451 Uruguayan patients with AIDS and clinic diagnosis of disseminated mycobacterial infection were evaluated between 1999 and 2003. Samples were processed in the National Reference Center for Mycobacteria (Montevideo, Uruguay), using the automated blood culture system for mycobacteria MB-BacT (BioMérieux). Forty-five positive samples were detected (4.3%) corresponding to 26 patients with AIDS (average 2.3 samples per patient). In 10/26 patients M. avium complex (MAC) was identified and in 13/26 the isolated germ was M. tuberculosis. The average time of incubation was of 12.4 days (range 6-19 days) for MAC and of 22.6 days (range 7-35 days) for M. tuberculosis. Blood culture has demonstrated to be the best sample for the bacteriological confirmation of the disseminated mycobacterial infections when at least 2 samples by patient are studied. The frequency of isolates of M. tuberculosis and MAC in AIDS patients is according with a moderate prevalence of tuberculosis in Uruguay.

Environmental mycobacteria (EM) constitute an important group of bacteria species found in the environment. They can colonize and occasionally produce disease in man. Sixteen thousand three hundred samples from 9300 adult symptomatic patients from the Hospital Regional of Tuberculosis in Cordoba were bacteriolocally investigated. The isolations were performed by culture on Lowenstein Jensen and Stonebrink culture media. The colonies of acid fast bacilli (AFB) were identified by biochemical and molecular tests. Among 716 culture positive cases, 684 (95.5%) were due to Mycobacterium tuberculosis complex and 32 to environmental mycobacteria. Serial samples allowed the confirmation of the etiological agent in culture and correlated with consistent clinical and radiological abnormalities. Seventy-five percent of these patients were affected by M. avium complex, 15.6% by M. fortuitum, 3.1% Mycobacterium kansasii and 6.3% Mycobacterium chelonae. Among tuberculosis cases, 94.5% and 5.5% had pulmonary and extrapulmonary disease respectively.

Mycobacterium avium complex (MAC) infections are the most frequent systemic infections associated with advanced AIDS. DNA probes for accurate identification of mycobacteria are available but are very expensive in many Latin American settings. Consequently, most Latin American diagnostic laboratories employ inaccurate and outdated tests for mycobacteria identification. Therefore, PCR restriction analysis (PRA) of the hsp65 gene was evaluated for the identification of 163 MAC human isolates originated from Spain and South America. The predominant PRA type in each country was: M. avium type I in Argentina (23/42, 55%) and Brazil (48/72, 67%), M. avium type II in Spain (18/26, 69%) and M. avium type III in Colombia (10/23, 43%). The Colombia frequency is noteworthy, since the PRA type III was quite infrequent in the other three countries. Furthermore, its presence has not been reported outside the Americas. The advantages and disadvantages of PRA in diagnostic mycobacteriology are discussed.

Consecutive samples of urine from a patient presenting radiological images of multicystic kidneys were microbiologically analyzed searching the possible presence of acid-alcohol resistant bacilli. The patient had already undergone complementary tests, which evidenced a kidney failure. As a result, it was isolated a slow-growth non pigmented mycobacterial strain corresponding to group III of Runyon. It was classified as Mycobacterium avium-intracellulare, according to conventional and alternative bacteriological studies, such as the analysis of fractions of mycobacterial mycolic acids by thin layer chromatography technique.

A 64 years-old patient, who was a farmer suffering from chronic fever for two years, loss of weight and acute asthenia, was studied. He was admitted to "Pedro Kourí" Tropical Medicine Institute where the studies were conducted and revealed a globular sedimentation rate of 116 mm in 2 hours, and anemia of 9,8g% hemoglobin. The laparoscopic study indicated hepatic granulomatosis that was confirmed by hepatic biopsy in which a sample was taken from the liver to be microbiologically and cytologically examined. By microbiological methods, a non-pigmented slowly-growing strain was isolated, which was classified by conventional diagnostic techniques for the non-tuberculous mycobacteria classification and the alternative diagnosing technique known as bidimensional thin layer chromatography to confirm the previous classification and set the mycolic acid patterns. The isolated strain belonged to group III of Rynyon and was identified as Mycobacterium avium-intracellulare.

The prevalence of nontuberculous mycobacteria (NTM) isolated from the lower airways of adult cystic fibrosis (CF) patients appears to be increasing. Different centers of USA, England, Sweden and Ireland have reported a prevalence ranging from 1.5 to 19.5%. The aim of the present study was to investigate the presence of NTM in patients assisted at these centers. A total of 92 sputum specimens and/or gastric contents from 40 CF patients were studied. Ages of patients ranged from 4 months to 25 years. Samples were obtained during acute exacerbation or in routine check-up. Mycobacterium avium-intracellulare complex strains were isolated from six patients with moderate or severe clinical manifestations. Five of these patients were considered as being colonized by NTM. Active mycobacterial disease was diagnosed in one patient and he underwent treatment. The index of bacterial contamination of cultures was very high early along the study (57%), decreasing to 2.8% later due to a change in the methodology used in the processing of samples. It was concluded that the presence of NTM is relatively frequent in patients with CF, even in children with moderate or severe compromise, a fact which strongly suggests that NTM should be systematically searched for considering the possibility that the patients might develop active disease.

The human immunodeficiency virus (HIV) epidemic has altered the epidemiological profile of tuberculosis in both industrialized and developing countries. Serious diseases caused by mycobacteria other that M. tuberculosis, mostly belonging to the M. avium-intracellulare complex (MAC), have become very common in association with severe immunosuppression. The increase in mycobacterial disease complexity has stimulated the development of more rapid and efficient methods of diagnosis. In the present study we characterized the cellular fatty acids and the mycolic acid cleavage product from most frequent mycobacteria species in Argentina using gas chromatography in order to develop a rapid technique for their identification. Fatty acids and mycolic acids extracted from saponified mycobacterial cells were examined as methyl esters by capillary has chromatography. The major constituent fatty acids in all species, with the exception of M. smegmatis, were octadecenoic (18:1) and hexadecanoic (16:1) acids. The fatty acids and mycolic acid cleavage product profiles from the studied species were quantitatively but not qualitatively different. Tuberculostearic acid was found in all species. Significantly different amounts of some fatty acids (p < 0.01) were observed among clinical isolates of M. tuberculosis, M. bovis and MAC. Traces of 2-eicosanol were detected in the M. tuberculosis H37Rv strain. Although a limited number of strains and species were tested, preliminary results indicate that this method could be used to characterize mycobacterial cultures.

Diseases caused by opportunistic ambient mycobacteria (OAM) are common in HIV-positive patients, although they also occur in immunocompetent individuals. The objective of the present study was to describe the risk factors, clinical signs, course and microbiological spectrum of OAM that cause pulmonary diseases in non HIV-infected individuals in our community. We reviewed 29 consecutive patients with OAM-caused pulmonary disease between 1989-1994 (26 men and 3 women, mean age 58 +/- 14 years). Infections were by Mycobacterium kansasii, 19 (66%) cases; M. avium complex, 7 (24%) cases; M. chelonei, 2 (7%) cases, and M. flavescens, one (3%) case. Risk factors most often associated to infection were smoking and a history of pulmonary disease (chronic obstructive pulmonary disease or residual tuberculosis). Clinical signs were non specific, although toxic syndrome and unproductive cough predominated. Chest films were indistinguishable from those for infection by M. tuberculosis, with cavitated alveolar fibrosis being the main pattern. In vitro drug sensitivity tests showed that all strains were resistant to isoniazid, and that M. avium complex and M. chelonei strains were resistant to rifampicin, streptomycin and, to a lesser degree, to ethambutol. With prolonged medical treatment lasting from 12 to 24 months with first line drugs, outcome was good for the 17 patients for whom full follow-up information was available. Therapy failed to eradicate the bacteria in only 2 patients.

The macrobroth dilution method was used for determining the resistance and/or sensitivity of 10 nontuberculous mycobacteria strains from Mycobacterium avium-intracellulare (MAI) complex isolated from patients presenting with respiratory symptoms. Drugs employed were as follows: isoniazid, ethambutol, rifampicin, streptomycin, gentamicin and amikacin. With respect to susceptibility of the strains studied, the greater sensitivity was found to be against ethambutol, amikacin, and gentamicin. The possibility of replacing the Middlebrook 7H9 liquid culture medium by the UIT-L liquid culture medium was analyzed. Normalization of the method was attained and a shortening of the reading time when using the UIT-L culture medium was also obtained.

Background: The usefulness of the microscopic examination of Bactec 12B and 13A growth medium as a method for the possible identification of M. tuberculosis complex, M. avium complex, M. xenopi, and M. kansasii was performed out to guide the selection of different genetic identification probes and, in the case of M. xenopi, the selection of the temperature of subcultures incubation., Methods: Upon detection of an index of growth greater than 100 in Bactec tubes, staining was performed by the Ziehl-Neelsen technique. On the basis of the morphology observed, the possible identification was performed by genetic probes. Subcultures were used for definitive identification., Results: Three hundred forty-four positive samples were studied by radiometric technique. A total of 190 strains were identified as M. tuberculosis, 88 strains as M. avium-intracellulare (MAI), 33 strains as M. xenopi, 14 strains as M. kansasii and 19 strains were identified as: M. gordonae (10), unpigmented rapid growth microbacteria (7), and M. simiae (2). Sensitivity, specificity, positive predictive value, and negative predictive value were 97.9%, 95.4%, 96.4%, and 97.3%, respectively for M. tuberculosis complex, 84.0%, 99.2%, 97.3% 94.7% for M. avium complex; 63.6%, 98.3%, 80.7%, 96.2% for M. xenopi; 35.7%, 98.1%, 45.5% 97.2% for M. kansasii., Conclusions: The morphology of M. tuberculosis complex examined in the radiometric system in useful to differentiate this species from other microbacteria (MOTT), allowing the selection of specific probe used. Within the MOTT, M. avium complex also has morphological characteristics which are useful for its differentiation, the morphology usually described for the remaining species was frequently not observed.

In order to analyze the usefulness of bronchoalveolar lavage (BAL) for conventional microbiological diagnosis of tuberculosis (TB) and other mycobacteria, and to assess the need to use it or not as a routine diagnostic technique in these diseases, we studied 30 patients with mycobacteria (26 TB and 4 Mycobacterium avium-intracellulare infections) by bronchoscopy, with BAL and bronchoaspirate (BAS) bacteriological analyses also available. The results were compared with those obtained for sputum taken before and after bronchoscopy when these specimens were available. The overall yield for BAL and BAS cultures was 90%, with BAL (83.3%) specimens being more productive than BAS (73.3%) specimens. Both performed far better than the 53.8% recorded for cultures of pre-bronchoscopy sputum and 60% for post-bronchoscopy sputum. BAL was the only diagnostic specimen from 7 patients, while BAS the only one from 4. Sensitivity was similar for the two mycobacteria studied. The results for direct bacilloscopy, however, at 30% for the two specimens, rose to 36.6% when they were analyzed together with BAS and BAL. We conclude that bronchoscopy should be performed on all patients suspected of mycobacterial infection when sputum bacilloscopy is negative and patients have no expectoration. Performance of BAL should be routine since this simple and usually uncomplicated technique produces the most productive specimens.

The objective of this study was to evaluate the usefulness of blood culture in the diagnosis of disseminated mycobacteria (DMB). This prospective study included all blood cultures done for patients with fever and under suspicion of having DMB between January 1991 and July 1992. Fifty-seven blood samples from 16 patients were cultured; 14 (87.5%) patients were HIV positive and all were diagnosed as having DMB. The cultures were processed by lysis-centrifugation and identification of mycobacteria was by hybridization with a DNA probe. Mycobacterial growth was detected in 5 cultures (8.7%) from 4 patients (25%) (3 HIV positive). M. tuberculosis was isolated in 3 and M. avium in 1. Mean time until isolation was 46 days. In all cases mycobacteria were isolated in other samples before they were found in cultures: M. tuberculosis was isolated in 2 bronchial aspirates (BAS), 2 in liver tissue (L), 2 in spleen tissue (S), one in alveolar bronchial lavage, one in sputum, one in spinal fluid (SF) and one in urine. M. avium was isolated in sputum and ALB. The three patients in whom M. tuberculosis was found died 1.4 and 32 days after admission. In samples from the 12 DMB patients with negative cultures (11 HIV positive, 92%), M. tuberculosis was isolated in 100% of ganglion and S samples, 90% in urine, 69% in sputum, 67% in ABL and LB, 63% in BAS and 33% in SF. None of these patients died in hospital. We find blood culture to be of little use in the diagnosis of DMB. Analysis of other samples leads to faster diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: To assess the utility of Bactec non-radiometric system in detecting disseminated mycobacteremia., Methods: Blood cultures are processed using the Bactec NR 660/HPS system. Incubation of the NR6A vials, from HIV infected patients, is prolonged for 6 weeks and read once a week. After the 14th day of incubation a growth value > or = 30 is considered positive., Results: Mycobacteria were recovered from 80 blood cultures from 32 human immunodeficiency virus infected patients. The mean time required to detect growth was 37.8 days (range 20-45). Mycobacterium tuberculosis was isolated from 18 patients and Mycobacterium avium from 14. In 12 patients (37.5%) blood culture was the first or the only positive specimen., Conclusions: Prolonged incubation of NR6A medium has proved to be a suitable method for detecting mycobacteremia.

441 strain of mycobacteria were exposed to probes marked with luminous material belonged to M. tuberculosis complex and M. avium complex. We analyzed the following points: 1. If the cut-off points obtained with our strains were in accordance to those recommended by the manufacturer, using two different luminometers. 2. If the correlation constant makes possible the conversion of the units form one luminometer to the units obtained with the other one. 3. Data for sensibility, specificity and predictive positive and negative values using different cut-off points. Cut-off points were different in all cases except for the data obtained with one luminometer using a probe belonged to M. tuberculosis complex. In this case the correlation constant could not be used. In contrast, whichever the luminometer employed was, we found no significant differences between sensibility, specificity and predictive values.