Characterization of 17 strains belonging to the Mycobacterium simiae complex and description of Mycobacterium paraense sp. nov

Non-tuberculous mycobacterial disease associated with Mycobacterium montefiorense in salamanders

Introduction

Mycobacterium montefiorense is one of the causes of non-tuberculous mycobacterial infections in moray eels and salamanders. Although M. montefiorense infection could be a threat to salamanders, little information is available regarding this pathogen and associated infection. This study aimed to provide fundamental information regarding M. montefiorense and its infection in salamanders.

Methods

Nine M. montefiorense strains isolated from three species of salamanders, namely, Japanese black salamander (Hynobius nigrescens), Hakuba salamander (H. hidamontanus), and Tohoku hynobiid salamander (H. lichenatus), between 2010 and 2018, were characterized based on phenotypic and genetic examination. We also pathologically observed salamanders infected with the M. montefiorense strains, including Hakuba salamanders and Tohoku hynobiid salamanders.

Results

The microbiological and chemical characteristics of the M. montefiorense salamander and an eel strain (reference strain) matched. Susceptibility testing for antimicrobials suggested that clarithromycin may be effective. Regarding disinfectants, phtharal, peracetic acid, glutaral, sodium hypochlorite, and benzalkonium chloride may be effective. Phylogenetic analyses revealed that the strains isolated from salamanders in 2014 and 2018 were genetically closely related, which could indicate an outbreak. The main gross findings in infected salamanders include skin ulcerative lesions or nodules in the enlarged liver. Microscopically, multifocal to coalescent granulomatous lesions composed of massive macrophages containing numerous acid-fast bacilli were prominently observed in the liver.

Conclusion

This study contributes to our understanding of the genetic diversity and phenotypic characteristics of M. montefiorense, as well as the pathology of the infection.

Potential Use of Mycobacterium paragordonae for Antimycobacterial Drug Screening Systems

Our recent genome-based study indicated that Mycobacterium paragordonae (Mpg) has evolved to become more adapted to an intracellular lifestyle within free-living environmental amoeba and its enhanced intracellular survival within Acanthamoeba castellanii was also proved. Here, we sought to investigate potential use of Mpg for antimycobacterial drug screening systems. Our data showed that Mpg is more susceptible to various antibiotics compared to the close species M. marinum (Mmar) and M. gordonae, further supporting its intracellular lifestyle in environments, which would explain its protection from environmental insults. In addition, we developed two bacterial whole-cell-based drug screening systems using a recombinant Mpg stain harboring a luciferase reporter vector (rMpg-LuxG13): one for direct application to rMpg-LuxG13 and the other for drug screening via the interaction of rMpg-LuxG13 with A. castellanii. Direct application to rMpg-LuxG13 showed lower inhibitory concentration 50 (IC50) values of rifampin, isoniazid, clarithromycin, and ciprofloxacin against Mpg compared to Mmar. Application of drug screening system via the interaction of rMpg-LuxG13 with A. castellanii also exhibited lower IC50 values for rifampin against Mpg compared to Mmar. In conclusion, our data indicate that Mpg is more susceptible to various antibiotics than other strains. In addition, our data also demonstrate the feasibility of two whole cell-based drug screening systems using rMpg-LuxG13 strain for the discovery of novel anti-mycobacterial drugs.

ISOLATION AND ANTIMICROBIAL SUSCEPTIBILITIES OF NONTUBERCULOUS MYCOBACTERIA FROM WILDLIFE IN JAPAN

Nontuberculous mycobacteria (NTM) are opportunistic pathogens of humans and animals and are transmitted among the environment, wildlife, livestock, and humans. The aim of this study was to investigate the rate of isolation and antimicrobial susceptibility of NTM in wildlife. In total, 178 samples of feces (n=131) and tissues (n=47) were collected from 11 wildlife species in Gifu Prefecture and Mie Prefecture, Japan, between June 2016 and October 2018. We isolated NTM from 15.3% (20/ 131) of fecal samples using Ogawa medium, and isolates were identified by sequencing the rpoB and hsp65 genes. The rpoB sequences were compared with those from other strains of human and environmental origin. The NTM isolates were obtained from sika deer (Cervus nippon), wild boar (Sus scrofa), Japanese monkey (Macaca fuscata), raccoon dog (Nyctereutes procyonoides), masked palm civet (Paguma larvata), and Japanese weasel (Mustela itatsi) and were classified as rapidly growing mycobacteria (RGM) and slowly growing mycobacteria (SGM). The 12 RGM identified were Mycolicibacterium peregrinum (n=5), Mycolicibacterium fortuitum (n=3), Mycolicibacterium septicum (n=3), and Mycolicibacterium thermoresistibile (n=1), and the eight SGM were Mycobacterium paraense (n=4), Mycolicibacter arupensis (n=2), Mycolicibacter virginiensis (n=1), and Mycobacterium nebraskense (n=1). The NTM from wildlife showed ≥99% similarity with strains from different sources including humans. The RGM were susceptible to the antimicrobial agents tested except for M. fortuitum, which was resistant to azithromycin and clarithromycin. The SGM showed multiple drug resistance qualities but were susceptible to amikacin, clarithromycin, and rifabutin. These results indicate that wildlife may be reservoir hosts of NTM in Japan. The presence of antimicrobial-resistant NTM in wildlife suggests that the trends of NTM antimicrobial susceptibility in wildlife should be monitored.

Characterization of Clinical Isolates of Mycobacterium simiae Using Drug Susceptibility Tests and Molecular Analyses

Mycobacterium simiae is an emerging nontuberculous mycobacterium (NTM) and an opportunistic pathogen which is described mainly in Asia and presents in the environment that can cause pulmonary infection. The objective of this study is to characterize M. simiae clinical isolates using mycobacterial interspersed repetitive unit variable-number tandem repeats (MIRU-VNTR) typing for the differentiation of the strains. A total of 169 clinical isolates of NTM were recovered from patients suspected of having tuberculosis (TB)-like and related infections. After isolation and identification of mycobacterial strains by conventional biochemical and PCR-based tests, M. simiae strains were confirmed using restriction fragment length polymorphism (RFLP)-based identification assay. Furthermore, drug susceptibility and MIRU-VNTR typing was performed using on the clinical isolates of M. simiae. Out of 169 NTM strains, 92 (54.4%) isolates were identified as M. simiae. Antibiotic susceptibility experiments indicated that all 92 M. simiae isolates were resistant to first line antimycobacterial agents. Moreover, 8 (8.6%) M. simiae isolates were resistant to ciprofloxacin; and 6 (6.5%) were resistant to both amikacin and kanamycin, while the remaining were susceptible to second line antimycobacterial agents. MIRU-VNTR analysis showed that the M. simiae isolates were classified in four distinct M. simiae clusters and two single types. The minimum spanning analysis revealed that the isolates were grouped in three complexes. The data suggested that MIRI-VNTR typing is useful for typing of M. simiae isolates, however, MIRU-16 locus was absolutely absent in M. simiae.

Mycobacterium helveticum sp. nov., a novel slowly growing mycobacterial species associated with granulomatous lesions in adult swine

The occurrence of nontuberculous mycobacteria in different hosts and their implication as obligate or opportunistic pathogens remain mainly unclear. Mycobacteriosis in pigs is usually associated with members of the Mycobacterium avium complex and, in particular, with ‘Mycobacterium avium subsp. hominissuis’. Here we describe a novel slow-growing mycobacterial species isolated from lymph nodes obtained from two sows housed in different Swiss farms. The animals presented chronic inappetence and mild diarrhoea. Gross pathology revealed focal caseous lymphadenopathy of the mesenteric lymph nodes. Complete genome sequencing of the two isolates from the two sows was performed. The genomes comprised 5.76 Mb and an average nucleotide identity score of 99.97 %. Whole genome sequence, mycolic acid and matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses revealed that the two isolates were not related to any previously described Mycobacterium species. The closest related species was Mycobacterium parmense, a slow-growing scotochromogenic mycobacterium first isolated from a cervical lymph node of a 3-year-old child. The name proposed for the new species is Mycobacterium helveticum sp. nov. and 16-83^T (=DSM 109965^T= LMG 2019-02457^T) is the type strain.

Disseminated Mycobacterium simiae infection in a patient with adult-onset immunodeficiency due to anti-interferon-gamma antibodies - a case report

Background

Mycobacterial species other than Mycobacterium tuberculosis and Mycobacterium leprae are generally free-living organisms and Mycobacterium simiae is one of the slowest growing Non-tuberculous mycobacteria. This is the first case report of Mycobacterium simiae infection in Sri Lanka and only very few cases with extrapulmonary manifestation reported in the literature.

Case presentation

A 24-year-old, previously healthy Sri Lankan male presented with generalized lymphadenopathy with discharging sinuses, evening pyrexia, weight loss, poor appetite and splenomegaly. Lymph node biopsies showed sheets of macrophages packed with organisms in the absence of granulomata. Ziehl Neelsen, Wade Fite and Giemsa stains revealed numerous red coloured acid-fast bacilli within foamy histiocytes. Slit skin smear for leprosy was negative and tuberculosis, fungal and bacterial cultures of the lymph node and bone marrow did not reveal any growth. Later he developed watery diarrhea and colonoscopy revealed multiple small polyps and ulcers throughout the colon extending up to the ileum, Which was confirmed to be due to cytomegalovirus confirmed by PCR and successfully treated with ganciclovir. Positron emission tomography scan guided biopsies of the gut and lymph nodes confirmed presence of mycobacterial spindle cell pseudo-tumours and PCR assays revealed positive HSP65. The culture grew Mycobacterium Simiae. Flow cytometry analysis on patient’s blood showed extremely low T and B cell counts and immunofixation revealed low immunoglobulin levels. His condition was later diagnosed as adult onset immunodeficiency due to anti- interferon – gamma autoantibodies. He was initially commenced on empirical anti-TB treatment with atypical mycobacterial coverage. He is currently on a combination of daily clarithromycin, ciprofloxacin, linezolid with monthly 2 g/kg/intravenous immunoglobulin to which, he had a remarkable clinical response with complete resolution of lymphadenopathy and healing of sinuses.

Conclusions

This infection is considered to be restricted to certain geographic areas such as mainly Iran, Cuba, Israel and Arizona and this is the first case report from Sri lanka. Even though the infection is mostly seen in the elderly patients, our patient was only 24 years old. In the literature pulmonary involvement was common presentation, but in this case the patient had generalized lymphadenopathy and colonic involvement without pulmonary involvement.

Genome-Based Taxonomic Classification of the Phylum Actinobacteria

The application of phylogenetic taxonomic procedures led to improvements in the classification of bacteria assigned to the phylum Actinobacteria but even so there remains a need to further clarify relationships within a taxon that encompasses organisms of agricultural, biotechnological, clinical, and ecological importance. Classification of the morphologically diverse bacteria belonging to this large phylum based on a limited number of features has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees. Here, draft genome sequences of a large collection of actinobacterial type strains were used to infer phylogenetic trees from genome-scale data using principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families, and genera, as well as many species and a few subspecies were shown to be in need of revision leading to proposals for the recognition of 2 orders, 10 families, and 17 genera, as well as the transfer of over 100 species to other genera. In addition, emended descriptions are given for many species mainly involving the addition of data on genome size and DNA G+C content, the former can be considered to be a valuable taxonomic marker in actinobacterial systematics. Many of the incongruities detected when the results of the present study were compared with existing classifications had been recognized from 16S rRNA gene trees though whole-genome phylogenies proved to be much better resolved. The few significant incongruities found between 16S/23S rRNA and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences. Similarly good congruence was found between the discontinuous distribution of phenotypic properties and taxa delineated in the phylogenetic trees though diverse non-monophyletic taxa appeared to be based on the use of plesiomorphic character states as diagnostic features.

Mycobacterium shigaense sp. nov., a slow-growing, scotochromogenic species, is a member of the Mycobacterium simiae complex

Among non-tuberculous mycobacteria (NTM), the Mycobacterium simiae complex is one of the largest groups, consisting of 18 species of slow-growing mycobacteria. In 2009, a case of NTM-associated infectious skin disease was reported in Shiga Prefecture, Japan. The patient presented with scattered nodules on the chest, back and extremities, and an M. simiae-like organism was isolated from skin biopsy specimens obtained from one of these lesions. Based on several assessments, including multiple-gene analyses, biochemical characterization and drug susceptibility testing, we concluded that this isolate represented a novel species of NTM, and proposed the name 'Mycobacterium shigaense'. Since 2009, five more cases of NTM-associated infectious disease in which there was a suspected involvement of 'M. shigaense' have been reported. Interestingly, four of these six cases occurred in Shiga Prefecture. Here we performed multiple-gene phylogenetic analyses, physiological and biochemical characterization tests, drug susceptibility tests, and profiling of proteins, fatty acids and mycolic acids of eight clinical isolates from the six suspected 'M. shigaense' cases. The results confirmed that all of the clinical isolates were 'M. shigaense', a slow-growing, scotochromogenic species. Here M. shigaense is validly proposed as a new member of the M. simiae complex, with the type strain being UN-152^T (=JCM 32072^T=DSM 46748^T).

Mycobacterium terramassiliense, Mycobacterium rhizamassiliense and Mycobacterium numidiamassiliense sp. nov., three new Mycobacterium simiae complex species cultured from plant roots

Three slowly growing mycobacteria named strain AB308, strain AB215 and strain AB57 were isolated from the tomato plant roots. The 16S rRNA and rpoB gene sequence analyses suggested that each strain was representative of one hitherto unidentified slowly-growing Mycobacterium species of the Mycobacterium simiae complex. Genome sequencing indicated that each strain contained one chromosome of 6.015-6.029 Mbp. A total of 1,197, 1,239 and 1,175 proteins were found to be associated with virulence and 107, 76 and 82 proteins were associated with toxin/antitoxin systems for strains AB308, AB215 and AB57, respectively. The three genomes encode for secondary metabolites, with 38, 33 and 46 genes found to be associated with polyketide synthases/non-ribosomal peptide synthases and nine, seven and ten genes encoding for bacteriocins, respectively. The genome of strain AB308 encodes for one questionable prophage and three incomplete prophages, while only incomplete prophages were predicted in AB215 and AB57 genomes. Genetic and genomic data indicate that strains AB308, AB215 and AB57 are each representative of a new Mycobacterium species that we respectively named Mycobacterium terramassiliense, Mycobacterium numidiamassiliense and Mycobacterium rhizamassiliense.

Draft Genome Sequence of Mycobacterium montefiorense Isolated from Japanese Black Salamander (Hynobius nigrescens)

Mycobacterium montefiorense is a member of the Mycobacterium simiae complex, the largest group of nontuberculous mycobacteria. Here, we report the genome sequence of M. montefiorense isolate BS, isolated from diseased Japanese black salamander (Hynobius nigrescens) reared in an aquarium in Japan. This is the first reported case of an M. montefiorense infection in an amphibian.

L. Zein S, Bou Khalil P, Kara N, Kanafani ZA, Kanj N, Bou Akl I, Araj G, Berjaoui G, Kanj SS. Emergence of Mycobacterium simiae: A retrospective study from a tertiary care center in Lebanon

Objective

The objective of this study is to describe the clinical significance of Mycobacterium simiae at a major tertiary care center in Lebanon.

Methods

This is a retrospective study of patients with positive cultures for M. simiae isolated between 2004 and 2016 at the American University of Beirut Medical Center.

Results

This study included 103 M. simiae isolates recovered from 51 patients. Their mean age was 62.7 years. The majority were males and smokers. Specimens were mostly from respiratory sources (97%). Common comorbidities included chronic lung disease (such as chronic obstructive pulmonary disease), solid tumor, systemic disease, and diabetes mellitus. Productive cough and dyspnea were the most common symptoms. Frequent radiographic findings were infiltrates and nodules on chest X-ray and nodules, infiltrates, and bronchiectasis on chest computed tomography scan. Among 18 tested isolates, 5.8% were resistant to clarithromycin, 11.7% to amikacin, and 70–100% to other antimicrobials. Out of 13 patients receiving early treatment, 5 noted improvement, one had recurrence of symptoms, two received alternative diagnosis, and five died. Two of those deaths were related to M. simiae. Common treatment regimens included clarithromycin in different combinations with trimethoprim-sulfamethoxazole, moxifloxacin, and amikacin. Moreover, clofazimine was used in only two patients whose isolates were resistant to all but one agent. Duration of treatment ranged from 6–24 months.

Conclusion

In Lebanon, M. simiae is increasingly encountered with true infection rates of at least 47%. Furthermore, the prevalence of multidrug resistance among the Lebanese M. simiae isolates is very high limiting the treatment options.

Mycobacterium ahvazicum sp. nov., the nineteenth species of the Mycobacterium simiae complex

Four slowly growing mycobacteria isolates were isolated from the respiratory tract and soft tissue biopsies collected in four unrelated patients in Iran. Conventional phenotypic tests indicated that these four isolates were identical to Mycobacterium lentiflavum while 16S rRNA gene sequencing yielded a unique sequence separated from that of M. lentiflavum. One representative strain AFP-003^T was characterized as comprising a 6,121,237-bp chromosome (66.24% guanosine-cytosine content) encoding for 5,758 protein-coding genes, 50 tRNA and one complete rRNA operon. A total of 2,876 proteins were found to be associated with the mobilome, including 195 phage proteins. A total of 1,235 proteins were found to be associated with virulence and 96 with toxin/antitoxin systems. The genome of AFP-003^T has the genetic potential to produce secondary metabolites, with 39 genes found to be associated with polyketide synthases and non-ribosomal peptide syntases and 11 genes encoding for bacteriocins. Two regions encoding putative prophages and three OriC regions separated by the dnaA gene were predicted. Strain AFP-003^T genome exhibits 86% average nucleotide identity with Mycobacterium genavense genome. Genetic and genomic data indicate that strain AFP-003^T is representative of a novel Mycobacterium species that we named Mycobacterium ahvazicum, the nineteenth species of the expanding Mycobacterium simiae complex.

Practice Guidelines for Clinical Microbiology Laboratories: Mycobacteria

Mycobacteria are the causative organisms for diseases such as tuberculosis (TB), leprosy, Buruli ulcer, and pulmonary nontuberculous mycobacterial disease, to name the most important ones. In 2015, globally, almost 10 million people developed TB, and almost half a million patients suffered from its multidrug-resistant form. In 2016, a total of 9,287 new TB cases were reported in the United States. In 2015, there were 174,608 new case of leprosy worldwide. India, Brazil, and Indonesia reported the most leprosy cases. In 2015, the World Health Organization reported 2,037 new cases of Buruli ulcer, with most cases being reported in Africa. Pulmonary nontuberculous mycobacterial disease is an emerging public health challenge. The U.S. National Institutes of Health reported an increase from 20 to 47 cases/100,000 persons (or 8.2% per year) of pulmonary nontuberculous mycobacterial disease among adults aged 65 years or older throughout the United States, with 181,037 national annual cases estimated in 2014. This review describes contemporary methods for the laboratory diagnosis of mycobacterial diseases. Furthermore, the review considers the ever-changing health care delivery system and stresses the laboratory's need to adjust and embrace molecular technologies to provide shorter turnaround times and a higher quality of care for the patients who we serve.

Mycobacterium eburneum sp. nov., a non-chromogenic, fast-growing strain isolated from sputum

A polyphasic study was undertaken to establish the taxonomic position of a non-chromogenic, rapidly growing Mycobacterium strain that had been isolated from sputum. The strain, CECT 8775T, has chemotaxonomic and cultural properties consistent with its classification in the genus Mycobacterium and was distinguished from the type strains of closely related mycobacterial species, notably from Mycobacterium paraense DSM 46749T, its nearest phylogenetic neighbour, based on 16S rRNA, hsp65 and rpoB gene sequence data. These organisms were also distinguished by a broad range of chemotaxonomic and phenotypic features and by a digital DNA-DNA relatedness value of 22.8 %. Consequently, the strain is considered to represent a novel species of Mycobacterium for which the name Mycobacterium eburneum sp. nov is proposed; the type strain is X82T (CECT 8775T=DSM 44358T).

Genomic characterization of Nontuberculous Mycobacteria

Mycobacterium tuberculosis and Mycobacterium leprae have remained, for many years, the primary species of the genus Mycobacterium of clinical and microbiological interest. The other members of the genus, referred to as nontuberculous mycobacteria (NTM), have long been underinvestigated. In the last decades, however, the number of reports linking various NTM species with human diseases has steadily increased and treatment difficulties have emerged. Despite the availability of whole genome sequencing technologies, limited effort has been devoted to the genetic characterization of NTM species. As a consequence, the taxonomic and phylogenetic structure of the genus remains unsettled and genomic information is lacking to support the identification of these organisms in a clinical setting. In this work, we widen the knowledge of NTMs by reconstructing and analyzing the genomes of 41 previously uncharacterized NTM species. We provide the first comprehensive characterization of the genomic diversity of NTMs and open new venues for the clinical identification of opportunistic pathogens from this genus.

Draft Genome Sequence of Mycobacterium interjectum Strain ATCC 51457 T

Mycobacterium interjectum is a nontuberculosis species rarely responsible for human infection. The draft genome of M. interjectum ATCC 51457^T comprises 5,927,979 bp, exhibiting 67.91% G+C content, 5,314 protein-coding genes, and 51 predicted RNA genes.

Molecular Identification of Nontuberculous Mycobacteria in Humans in Zimbabwe Using 16S Ribosequencing

Background:

Several nontuberculous mycobacteria (NTM) were previously isolated from diverse environments such as water, soil, sewage, food and animals. Some of these NTM are now known to be opportunistic pathogens of humans.

Objective:

The main purpose of the study was to identify NTM isolates stored at the National Microbiology Reference Laboratory (NMRL) and were previously isolated from humans during a national tuberculosis (TB) survey.

Methods:

Pure NTM cultures already isolated from human sputum samples during the national TB survey were retrieved from the NMRL and used for this study. DNA was extracted from the samples and 16S ribosomal RNA gene amplified by polymerase chain reaction. The amplicons were sequenced and bioinformatics tools were used to identify the NTM species.

Results:

Out of total of 963 NTM isolates stored at the NMRL, 81 were retrieved for speciation. Forty isolates (49.4%) were found to belong to Mycobacterium avium-intracellulare complex (MAC) species. The other 41 isolates (50.6%) were identified as M. lentiflavum (6.2%), M. terrae complex (4.9%), M. paraense (4.9%), M. kansasii (3.7%), M. moriokaense (3.7%), M. asiaticum (2.5%), M. novocastrense (2.5%), M. brasiliensis (2.5%), M. elephantis (2.5%), M. paraffinicum (1.2%), M. bohemicum (1.2%), M. manitobense (1.2%), M. intermedium (1.2%), M. tuberculosis complex (1.2%), M. parakoreense (1.2%), M. florentinum (1.2%), M. litorale (1.2%), M. fluoranthenivorans (1.2%), M. sherrisii (1.2%), M. fortuitum (1.2%) and M septicum (1.2%). Two isolates (2.5%) could not be identified, but were closely related to M. montefiorense and M. phlei respectively. Interestingly, the MAC species were the commonest NTM during the survey.

Conclusion:

The study emphasizes the importance of identifying species of NTM in Zimbabwe. Future studies need to ascertain their true diversity and clinical relevance.

Increased isolation of nontuberculous mycobacteria among TB suspects in Northeastern, Tanzania: public health and diagnostic implications for control programmes

BACKGROUND

Non-tuberculous mycobacteria (NTM) are increasingly reported worldwide associated with human disease. Defining the significance of NTM in settings with endemic tuberculosis (TB) requires the discrimination of NTM from TB in suspect patients. Correct and timely identification of NTM will impact both therapy and epidemiology of TB and TB-like diseases. The present study aimed at determining the frequency and diversity of NTM among TB suspects in northeastern Tanzania.

METHODS

A cross-sectional study was conducted between November 2012 through January 2013. Seven hundred and forty-four sputum samples were collected from 372 TB suspects. Detection was done by using phenotypic, GenoType(®) Mycobacterium CM/AS kits, 16S rRNA and hsp65 gene sequencing for identification of isolates not identified by Hain kits. Binary regression model was used to analyse the predictors of NTM detection.

RESULTS

The prevalence of NTM was 9.7% of the mycobacterial isolates. Out of 36 patients with confirmed NTM infection, 12 were HIV infected with HIV being a significant predictor of NTM detection (P < 0.001). Co-infection with Mycobacterium tuberculosis (M. tb) was found in five patients. Twenty-eight NTM isolates were identified using GenoType(®) Mycobacterium CM/AS and eight isolates could not be identified. Identified species included M. gordonae and M. interjectum 6 (16.7%), M. intracelullare 4 (11.1%), M. avium spp. and M. fortuitum 2 (5.5%), M. kansasii, M. lentiflavum, M. simiae, M. celatum, M. marinum 1 (2.8%) each. Of isolates not identified to subspecies level, we identified M. kumamotonense (2), M. intracellulare/kansasii, M. intermedium/triplex, M. acapulcensis/flavescens, M. stomatepiae, M. colombiense and M. terrae complex (1) each using 16S rRNA sequencing. Additionally, hsp65 gene sequencing identified M. kumamotonense, M. scrofulaceum/M. avium, M. avium, M. flavescens/novocastrense, M. kumamotonense/hiberniae, M. lentiflavum, M. colombiense/M. avium and M. kumamotonense/terrae/hiberniae (1) each. Results of the 16S rRNA and hsp65 gene sequencing were concordant in three and discordant in five isolates not identified by GenoType(®) Mycobacterium CM/AS.

CONCLUSION

NTM infections may play a vital role in causing lung disease and impact management of TB in endemic settings. GenoType(®) Mycobacterium CM/AS represents a useful tool to identify clinical NTM infections. However, 16S rRNA gene sequencing should be thought for confirmatory diagnosis of the clinical isolates. Due to the complexity and inconsistence of NTM identification, we recommend diagnosis of NTM infections be centralized by strengthening and setting up quality national and regional infrastructure.

The looming tide of nontuberculous mycobacterial infections in Portugal and Brazil

Nontuberculous mycobacteria (NTM) are widely disseminated in the environment and an emerging cause of infectious diseases worldwide. Their remarkable natural resistance to disinfectants and antibiotics and an ability to survive under low-nutrient conditions allows NTM to colonize and persist in man-made environments such as household and hospital water distribution systems. This overlap between human and NTM environments afforded new opportunities for human exposure, and for expression of their often neglected and underestimated pathogenic potential. Some risk factors predisposing to NTM disease have been identified and are mainly associated with immune fragilities of the human host. However, infections in apparently immunocompetent persons are also increasingly reported. The purpose of this review is to bring attention to this emerging health problem in Portugal and Brazil and to emphasize the urgent need for increased surveillance and more comprehensive epidemiological data in both countries, where such information is scarce and seriously thwarts the adoption of proper preventive strategies and therapeutic options.