Actualización del manejo de microbacterias no tuberculosas / Update on the management of non-tuberculous mycobacteria

Desde el año 2007 se han generado guías de diagnóstico y tratamiento de micobacterias no tuberculosas (MNTB), la última de las cuales fue desarrollada en el año 2020 por ATS/ERS/ESCMID/IDSA, en ella se actualizan los criterios diagnósticos, los criterios para determinar el inicio de tratamiento y recomendaciones de esquema de antibióticos para las especies más frecuentes. En paralelo se han ido desarrollando terapias alternativas como la fagoterapia. El objetivo de la presente revisión es dar a conocer los cambios que traen estas últimas guías y actualizar algunas de las últimas novedades con respecto al manejo de las micobacterias no tuberculosas.

Since 2007, guidelines for diagnosis and treatment of non-tuberculous Mycobacteria have been generated, the latest of which was developed by ATS/ERS/ESCMID/IDSA, in which the diagnostic criteria, and the criteria for determining the initiation of treatment and antibiotic scheme recommendations for the most frequent species are updated. At the same time, alternative therapies such as phage therapy have been developed. The objective of this review is to show the changes that these latest guidelines bring and update some of the latest developments regarding the management of non-tuberculous Mycobacteria.

Diagnostic value of neutrophil CD64 index in disseminated nontuberculous mycobacteria infection / 中华传染病杂志

Objective:To investigate the diagnostic value of neutrophil CD64 index (nCD64) in disseminated nontuberculous mycobacteria (NTM) infection.Methods:Thirty-six patients with NTM infection from January 2020 to June 2021 in Huashan Hospital, Fudan University were included. Patients were classified into groups of disseminated infection and focal infection according to their medical history and discharge diagnosis. The expressions of nCD64 in patients with focal infection and disseminated infection before treatment were collected and analyzed. Statistical analysis was performed using the Mann-Whitney U test, and the diagnostic value of nCD64 for disseminated NTM infection was analyzed using the receiver operator characteristic curve (ROC curve). Results:Among the 36 patients with NTM infection, 18 cases were focal infection (due to the low white blood cell count of the patient with myelodysplastic syndrome, the detection results were biased, which were excluded from the subsequent analysis) and 18 cases were disseminated infection. The expression of nCD64 in focal infection was 0.72(0.50, 1.55), and that in disseminated infection was 13.63(6.77, 32.31). The difference was statistically significant ( U=15.50, P<0.001). Using focal infection as a control, the area under the ROC curve for the operational characteristics of the subjects was 0.949 3 for disseminated NTM infection. The diagnostic cut-off value of nCD64 was 3.06, with the sensitivity and specificity of the disseminated NTM infection were 88.89% and 100.00%, respectively. Conclusions:In patients with NTM infection before effective treatment, the diagnostic cut-off value of nCD64 of 3.06 has high sensitivity and specificity, which is useful for the aided diagnosis of disseminated NTM infection.

Prevalence of systemic and local risk factors for pulmonary non-tuberculous mycobacterial disease in Japan: a single-institution study / Journal of Rural Medicine

Objective: To identify the prevalence of risk factors for pulmonary non-tuberculous mycobacterial (NTM) disease in a Japanese population.Patients and Methods: We reviewed 337 consecutive Japanese patients (210 women) with pulmonary NTM disease, including 225 patients with Mycobacterium avium complex (MAC) disease (95.8%) at our hospital during 2006–2017. We calculated the prevalence of risk factors reported in Western countries among mycobacterial species.Results: Pulmonary MAC disease cases comprised 78.2% of pulmonary NTM patients in their 40s, increasing to 100% at age ≥80 years. Body mass index (BMI) was <18.5 in approximately 40% of patients, which was significantly higher than the prevalence of underweight in the Japanese population. The percentage of male heavy smokers (Brinkman index ≥600) was 58.2% of pulmonary NTM disease and was high for all mycobacterial species. In pulmonary MAC disease, systemic factors were observed in the order of malignant tumors (other than lung cancer), diabetes, rheumatoid arthritis, and tuberculosis. Local factors were observed in the order of bronchiectasis, chronic obstructive pulmonary disease, lung cancer, and bronchial asthma.Conclusion: The risk factors reported in Western countries were relatively highly prevalent among Japanese pulmonary NTM disease patients. This observation may help elucidate disease onset mechanisms.

Eventos de precipitación extrema aumentan la circulación de patógenos infecciosos: detección de rotavirus, norovirus, astrovirus, adenovirus entérico y micobacterias no tuberculosas en agua de las inundaciones en Asunción, Paraguay, año 2014

Las precipitaciones extremas representan uno de los eventos naturales climáticos más importantes y pueden originar inundaciones devastadoras. De junio a agosto del 2014 se registró una de las más graves inundaciones en la historia de la ciudad de Asunción. Ocasionó un incremento considerable del nivel del río Paraguay y el desplazamiento de 300.000 personas a campamentos provisionales. Debido a que el contacto directo con el agua de inundación, el consumo de agua contaminada y la congregación de los afectados en refugios provisorios son factores de riesgo para enfermedades infecciosas, el objetivo de este estudio fue la implementación de una metodología estandarizada para la concentración y detección de virus entéricos y micobacterias no tuberculosas, por PCR en tiempo real y PCR-asociada al análisis de restricción enzimática (PRA), en muestras de agua de inundaciones y el reporte de los patógenos detectados en las zonas afectadas de Asunción y en la Bahía del Río Paraguay. La metodología propuesta demostró poseer buena sensibilidad y se registró la presencia de rotavirus, norovirus (genogrupos I y II), astrovirus, adenovirus entéricos y micobacterias no tuberculosas en 50% (N=4/8) de las muestras de los barrios Sajonia, San Jerónimo y Ricardo Brugada, Chacarita. Además, reportamos datos secundarios de casos de enfermedades infecciosas, registrados en los servicios de salud de los barrios afectados durante el periodo de inundación.

Extreme rainfall represents one of the most important natural climatic events and can cause devastating floods. From June to August 2014, one of the most serious floods in the history of the city of Asunción was recorded. It caused a considerable increase in the level of the Paraguay River and the displacement of 300,000 people to temporary camps. Since direct contact with flood water, consumption of contaminated water and the congregation of those affected in temporary shelters are risk factors for infectious diseases, the objective of this study was the implementation of a standardized methodology for the concentration and detection of enteric viruses and non-tuberculous mycobacteria, by real-time PCR and PCR-associated enzyme restriction analysis (PRA), in samples of flood water and the report of the pathogens detected in the affected areas of Asunción and in the Bay of the Paraguay River. The proposed methodology proved to have good sensitivity and the presence of rotavirus, norovirus (genogroups I and II), astrovirus, enteric adenovirus and non-tuberculous mycobacteria was recorded in 50% (N=4/8) of the samples from the Sajonia, San Jeronimo and Ricardo Brugada, Chacarita neighborhoods. In addition, we report secondary data on cases of infectious diseases, registered in the health services of the affected neighborhoods during the flood period.

Queratitis por Mycobaterium abscessus: comunicación del primer caso en Paraguay / Keratitis due to Mycobaterium abscessus: first case report in Paraguay

Resumen Se presenta un caso clínico de queratitis por Mycobacterium abscessus en una mujer de 76 años, residente en la ciudad de Asunción, sin traumatismo ni cirugía ocular previa y con antecedente de una queratouveitis herpética. Por tratarse de una queratitis causada por un agente etiológico poco frecuente y por la importancia de un diagnóstico correcto y oportuno para la instauración del tratamiento adecuado, se comunica el primer caso de queratitis por micobacterias en Paraguay.

Abstract We present a clinical case of keratitis caused by M. abscessus in a 76-year-old female patient, resident in the city of Asunción, without trauma or previous ocular surgery and with a history of herpetic keratouveitis. Because it is a keratitis caused by a rare etiological agent and because of the importance of a correct and timely diagnosis for the establishment of appropriate treatment, the present case is reported, the first of Mycobacteria keratitis in Paraguay.

Detection of non-tuberculosus mycobacteria (NTMs) in lung samples using 16S rRNA

BACKGROUND Non-tuberculous mycobacteria (NTMs) cause diseases known as mycobacteriosis and are an important cause of morbidity and mortality. The diagnosis of pulmonary disease caused by NTM is hampered by its clinical similarity with tuberculosis (TB) and by the lack of an accurate and rapid laboratory diagnosis. OBJECTIVES Detect DNA from NTMs directly from lung samples using real-time polymerase chain reaction (qPCR) for amplification of 16S rRNA. Additionally, DNA sequencing (hsp65 and rpoB genes) was used to identify the species of MNTs. METHODS A total of 68 sputum samples (54 with suspected NTMs and 14 with TB) from patients treated at a referral hospital were used. FINDINGS Of these, 27/54 (50%) were qPCR positive for NTMs and 14/14 TB patients (controls) were qPCR negative with an almost perfect concordance (Kappa of 0.93) with the Mycobacterium spp. culture. Sequencing confirmed the presence of NTM in all positive samples. The most common species was Mycobacterium gordonae (33%), followed by Mycobacterium abscessus (26%), Mycobacterium fortuitum (22%), Mycobacterium avium (15%) and Mycobacterium peregrinum (4%). MAIN CONCLUSIONS The qPCR technique for detecting NTMs targeting 16S rRNA has the potential to detect NTMs and rapidly differentiate from Mycobacterium tuberculosis. However, it is necessary to identify the species to help in the differential diagnosis between disease and contamination, and to guide the choice of the therapeutic scheme.

Clinical application of gene chip technology in diagnosis and treatment of silicosis complicated with mycobacterial infection / 环境与职业医学

Background Gene chip technology has been increasingly used in the diagnosis and treatment of common tuberculosis. However, its role in the diagnosis and treatment of silicosis complicated with mycobacterial infection remains unclear. Objective To evaluate the application value of gene chip technology in the diagnosis and treatment of silicosis complicated with mycobacterial infection. Methods From January 2019 to June 2021, 197 silicosis patients suspected to be complicated with mycobacterial infection in Quanzhou First Hospital Affiliated to Fujian Medical University were enrolled in this study. The etiology evaluation for the 197 patients was conducted by acid-fast staining of sputum smear (sputum smear method), culture of Mycobacterium tuberculosis of sputum (sputum culture method), and gene chip technology of bronchoalveolar lavage fluid (BALF); and for 80 patients among them, acid-fast staining of BALF (BALF smear method) and culture of Mycobacterium tuberculosis of BALF (BALF culture method) were additionally performed. The positive rates and consistency were assessed using intraclass correlation coefficient (ICC). Test for Mycobacterium tuberculosis drug resistance mutation gene was added for patients with Mycobacterium tuberculosis complex by BALF gene chip technology. Results The average age of the 197 patients was (53.1±9.1) years, and the average dust exposure time was (21.1±9.4) years, including 192 males and 5 females. There were 8 cases with stage I silicosis, 17 cases with stage II silicosis, and 172 cases with stage III silicosis. Among them, 11.2% were positive for sputum smear; 24.4% were positive for sputum culture, and 36.0% were positive by gene chip of BALF. The difference between the three methods was statistically significant (P<0.05). The result of consistency test for the three methods showed that the ICC was 0.539 (P<0.001). Among the 80 patients, there was a significant difference in the positive rates of the five methods (χ2=25.23, P<0.001). The results of Bonferroni test showed statistically significant pair-wise differences between BALF culture method and sputum smear method, BALF culture method and BALF smear method, BALF gene chip method and sputum smear method, BALF gene chip method and BALF smear method (P<0.05), while there were no statistically significant differences between the other pairs (P>0.05). The result of consistency test for the five methods showed that the ICC was 0.586 (P<0.001). Among the 71 BALF gene chip positive cases, 59 cases reported positive Mycobacterium tuberculosis complex (17 cases were positive in the first-line anti-tuberculosis resistance test, and 2 cases were found positive quinolone resistance gene in the second-line anti-tuberculosis resistance test), and received regular anti-tuberculosis treatment, among them 45 cases improved and 14 cases were stable; 12 cases reported non-tuberculous mycobacteria cases, among them 5 cases received anti-non-tuberculous mycobacteria treatment (4 cases improved and 1 case was stable), and 7 cases with mild symptoms did not receive anti-non-tuberculous mycobacteria treatment. Conclusion Compared with sputum smear, sputum culture, and other traditional methods, gene chip technology of BALF can improve the positive rate of pathogenic diagnosis of silicosis complicated with mycobacterial infection, and can also quickly identify whether it is non-tuberculous mycobacteria infection or drug-resistant Mycobacterium tuberculosis infection, which is helpful to adjust treatment as soon as possible.

Ocorrência de Micobactérias Não Tuberculosas (MNT) em uma unidade de referência do estado do Pará, Brasil / Occurrence of Nontuberculosis Mycotherapies (NTM) in a reference unit of the state of Pará, Brazil

Objetivo: Investigar a ocorrência de micobactérias não tuberculosas (MNT) em uma Unidade de Referência no Estado do Pará, Brasil e apresentar o perfil sociodemográfico e clínico dos pacientes acometidos. Métodos: foi realizada pesquisa descritiva retrospectiva com abordagem quantitativa por meio da coleta de dados no sistema de informação do laboratório que atua como referência para tuberculose nos vinte municípios da região Oeste do Pará no período de abril de 2011 a abril de 2017. Resultados: foram analisadas amostras de 513 pacientes com suspeita de TB, 09 (1,75%) tiveram diagnóstico de MNT, sendo isolados M. avium, M. asiaticum, M. intracellulare, M. paraensis e M. abscessus subsp. bolletii. Conclusão: evidencia­se o potencial das MNT em provocar doença semelhante à tuberculose, havendo a necessidade de melhorar a investigação etiológica para a detecção precoce das micobacterioses, afim de que sejam tomadas medidas adequadas de tratamento e prevenção da transmissão.

Objective: To investigate the occurrence of non­ tuberculous mycobacteria (NTM) in a Reference Unit in the State of Pará, Brazil, and present the sociodemographic and clinical profile of the patients affected. Methods: retrospective descriptive research was carried out using a quantitative approach through the data collection of the laboratory information system which acts as a reference for tuberculosis in the twenty municipalities of the western region of Pará from April 2011 to April 2017. Results: samples from 513 patients with suspected TB were analyzed, 09 (1.75%) were diagnosed with NTM , M. avium, M. asiaticum, M. intracellulare, M. paraenses and M. abscessus subsp. bolletii. Conclusion: the potential of MNT to provoke tuberculosis­like disease is evident, and there is a need to improve epidemiological investigation for the early detection of mycobacteriosis, so that appropriate treatment and prevention measures are taken.

Non-tuberculous mycobacterial lung disease: a brief review focusing on radiological findings

Abstract The incidence and prevalence of lung disease caused by non-tuberculous mycobacteria (NTM-LD) has increased worldwide and its diagnosis represents a complex challenge. This article aims to review the tomographic findings of NTM-LD in order to facilitate their definitive diagnosis. The search for publications on the subject was performed in PMC and Scielo using the keywords 'non-tuberculous mycobacteria', 'lung disease and computed tomography (CT)' and 'radiological findings'. The radiological findings described by 18 articles on mycobacteriosis were reviewed. In addition, CT images of patients diagnosed with NTM-LD were considered to represent radiological findings. Eighteen publications were used whose main findings were pulmonary cavitation (88.9%), bronchiectasis (77.8%), and pulmonary nodules (55.6%). Despite the overlaps in imaging-related analysis of myocobacterioses with other pulmonary infections, such as tuberculosis, the predominant involvement of the middle lobe and lingula should raise suspicion for NTM-LD.

Identification of nontuberculous mycobacteria species by multiplex real-time PCR with high-resolution melting

Abstract INTRODUCTION: Nontuberculous mycobacteria (NTM) species, as human pathogens, are increasing in the world, as is the difficulty of accurately identifying them. Differential diagnosis, especially between the M. tuberculosis complex and NTM species, and the characterization of NTM species is important. This study aimed to evaluate the performance of a molecular system based on multiplex real-time PCR with high-resolution melting (HRM) for the identification and differentiation of NTM species of clinical importance of an endemic area for tuberculosis in northeastern Brazil. METHODS: The technical protocol of the molecular system was based on multiplex real-time PCR-HRM, and evaluated the sensitivity and specificity of the detection of NTM species in mycobacterial clinical isolates from the studied region. The gold standard method was specific gene sequencing. RESULTS: The sensitivity and specificity of multiplex real-time PCR-HRM modified for differentiation between NTM and M. tuberculosis were 90% and 100%, respectively. The PCR-HRM sensitivities for the characterization of NTM species (M. kansasii, M. abscesses, M. avium, and M. fortuitum) were 94.59%, 80%, 57.14%, and 54%, respectively. CONCLUSIONS The multiplex real-time PCR-HRM modified assay has the potential to rapidly and efficiently identify nontuberculous mycobacteria of clinical importance, which is crucial for immediate implementation of the appropriate therapy and thus avoiding complications and sequelae in patients.

Antimicrobial and drug-synergistic potential of Alpinia conchigera Griff.-derived phenylpropanoids against Mycobacterium smegmatis

Aims@#This study aimed to evaluate the antimicrobial activity of naturally derived phenylpropanoids from Alpinia conchigera (A. conchigera) Griff. and its synthetic analogues, as well as interactions between selected compounds with first-line tuberculosis (TB) drug, rifampicin, against Mycobacterium smegmatis, a potential opportunistic nontuberculous mycobacterium (NTM) and a surrogate organism for TB. @*Methodology and results@#Twelve phenylpropanoids of A. conchigera were evaluated for antimicrobial activity against M. smegmatis (ATCC 14468). The phenylpropanoid compound from A. conchigera with the lowest minimum inhibitory concentration and bactericidal (MIC, MBC) values were selected for checkerboard tetrazolium microplate assay (TEMA) with rifampicin to determine drug interactions. A majority of the compounds had antimicrobial activity, however, purified natural compound 1'S-1'-acetoxychavicol acetate (ACA) showed the highest antimicrobial activity with an MIC value of 62.5 µg/mL against M. smegmatis. The combination of ACA and rifampicin produced indifferent interaction with fractional inhibition concentration (FIC) index of 1.5, while the combination of rifampicin and ACA synthetic analogue 4-allyl-2,6- methoxyphenyl isobutyrate produced a synergistic interaction effect with FIC index of 0.5. None of the compounds tested were bactericidal but appear to be bacteriostatic.@*Conclusion, significance and impact of study@#This study presents the first report on the antimicrobial potential of natural A. conchigera-derived ACA against M. smegmatis as well as the synergistic interaction of 4-allyl-2,6- methoxyphenyl isobutyrate with rifampicin which warrants further investigation.

Diversidad de especies de micobacterias no tuberculosas aisladas en ambientes acuáticos de la ciudad de General Pico, La Pampa, Argentina / Species diversity of non-tuberculous mycobacteria isolated from aquatic environments of General Pico city, Province of La Pampa (Argentina)

Las micobacterias no tuberculosas (MNT) no solo se estudian por su importancia como patógenos oportunistas, sino también por sus aplicaciones en biotecnología y biorremediación. Nuestro objetivo fue determinar la presencia de micobacterias en los distintos hábitats acuáticos de la ciudad de General Pico (provincia de La Pampa), así como su diversidad. Los porcentajes de muestras positivas a micobacterias fueron los siguientes: 37,5% en el sistema de distribución de agua de red, 32,6% en el acuífero que abastece dicho sistema, 36,8% en el agua proveniente de las precipitaciones, 53,1% en los humedales del área de influencia, 80% en los natatorios cubiertos y 33,3% en las fuentes decorativas ubicadas en plazas públicas. De los 90 aislamientos de MNT obtenidos el 8,9% no logró ser identificado a nivel de especie con los métodos utilizados, que incluyeron pruebas fenotípicas y métodos moleculares. Las especies más frecuentemente aisladas fueron Mycobacterium fortuitum y Mycobacterium gordonae. Algunas especies identificadas han sido reportadas en casos de micobacteriosis en nuestro país, entre ellas M. fortuitum, M. gordonae, M. intracellulare, M. vaccae, M. lentiflavum y M. nonchromogenicum. No se aislaron MNT en muestras de agua de red con concentraciones de cloro activo residual mayores de 0,8mg/l, mientras que en los natatorios la presencia de hasta 1,5mg/l de cloro activo residual no fue una limitante para la proliferación de estos microorganismos. Se puede considerar que la incidencia de micobacterias en los ambientes acuáticos de General Pico es cercana al 35%, y que la presencia de estos microorganismos y su diversidad se ve afectada por el contacto con el hombre y sus actividades, como así también por la existencia de vida animal.

Non-tuberculous mycobacteria (NTM) are studied not only for their importance as emerging opportunistic pathogens but also for their applications in biotechnology and bioremediation. Our aim was to determine the occurrence and diversity of mycobacteria in different aquatic habitats of General Pico city, Province of La Pampa. The percentage of samples with positive cultures for mycobacteria were the following: 37.5% recovered from the water supply distribution system; 32.6% from the aquifer that supplies water to the distribution system; 36.8% from rain water; 53.1% from the two wetlands in the area of influence; 80% from indoor swimming pools; and 33.3% from water fountains in downtown public squares. Of the 90 NTM isolates, 8.9% could not be identified at the species level with any of the used methods, phenotypic tests and molecular methods. Mycobacterium fortuitum and Mycobacterium gordonae were the most frequently isolated species. Some of the identified species such as, M. fortuitum, M. gordonae, M. intracellulare, M. vaccae, M. lentiflavum and M. nonchromogenicum, have been reported in cases of mycobacteriosis in Argentina. Mycobacteria with values higher than 0.8mg/ml of residual active chlorine were not recovered from the drinking water supply network, whereas in the swimming pools the presence of up to 1.5 mg/l was not a constraint. Based on our results, the presence of mycobacteria in aquatic environments is close to 35% and their occurrence and diversity is affected both by contact with man and his activities as well as by the existence of animal life.

Pulmonary Mycobacterium kyorinense disease: A case report and review of literature

We report here the first case of pulmonary infection due to Mycobacterium kyorinense in a 55-year-old hypertensive woman treated for pulmonary tuberculosis earlier on two occasions. She presented with productive cough, intermittent episode of left-sided chest pain, loss of appetite, low-grade fever, and breathlessness. Sputum cultures revealed non-tuberculous mycobacteria (NTM). She remained persistently symptomatic with sputum cultures positive for acid-fast bacilli even after 6 months of treatment. Hence, a 16SrRNA gene amplification and sequencing were done that revealed M. kyorinense. Based on the guidelines of the American Thoracic Society, she was started on weight-based dosing of clarithromycin, levofloxacin, ethambutol, isoniazid and injection amikacin daily. The patient improved symptomatically and became culture-negative after 3 months of therapy with the above regimen and continued to be culture negative for 12 months of treatment. She continues to remain symptom-free without evidence of any clinical or bacteriological relapse.

Research progress of intracranial infection associated with non-tuberculous mycobacteria / 解放军医学杂志

Non-tuberculous mycobacteria (NTM) refers to the mycobacteria other than M. tuberculosis complex and M. leprae complex, which is widely distributed in the natural environment and people can infect NTM from the environment. With the increased number of acquired immunodeficiency syndrome (AIDS) and the continuous use of immunosuppressants around the world, the number of diseases caused by NTM are also increasing continuously. However, NTM related intracranial infection is still a rare or even rare disease in clinic, which is often misdiagnosed or even missed diagnosis since the negative results of cerebrospinal fluid bacteria culture, the poor effect of anti-tuberculosis treatment and the high mortality. In present paper, we intend to summarize the documents that have been reported so far in order to review the definition of NTM, the susceptible population, classification, diagnosis and treatment of NTM related intracranial infection for further strengthening and improving awareness of such a kind of the disease.

Use of MALDI-TOF MS in diagnostic microbiology for identification of species that conventional methods usually fail to identify

(MALDI-TOF MS) has been used in clinical diagnostic laboratories for the identification of microorganisms. It has a relevant advantage compared to other methods in terms of speed to provide results, being an alternative for addressing restrictions in clinical diagnosis as it may replace or complement existing identification techniques. This is especially important because some rare microorganisms would be identified only by higher cost techniques which are not widely available, such as genetic sequencing. Thus, the present paper reports two cases in which uncommon microorganisms were identified effectively and quickly. (AU)

Mycobacteria in Minas cheese commercialized in open fairs in São Paulo, Brazil / Mycobacteria em queijos tipo Minas comercializados em feiras-livres de São Paulo, Brasil

Mycobacterium bovis is the causative agent of bovine tuberculosis, a disease that affects dairy herds throughout the Brazilian territory, constituting a neglected zoonosis transmitted by raw milk and its derivatives. In this study, we evaluated the presence of M. bovis and other mycobacteria in Minas cheese obtained from open fairs in the city of São Paulo between 2012 and 2013. Samples (n = 133) were decontaminated using hexa-cetylpyridinium chloride and seeded on Stonebrink­Leslie medium. The isolates were submitted to molecular identification by TB Multiplex PCR targeting the 16S rRNA gene and amplicon nucleotide sequencing. From 16 cheese samples (12%), we obtained 26 putative colonies of Mycobacterium spp, none of which belonged to any of the Mycobacterium tuberculosis, Mycobacterium avium, or Mycobacterium intracellulare complexes. Phylogenetic analysis showed that sample sequences were grouped in a clade that includes only non-tuberculous mycobacteria with proximity to sequences obtained from Mycobacterium novocastrense (3 sequences), Mycobacterium holsaticum (1 sequence), and Mycobacterium elephantis (2 sequences). Although no epidemiological evidence was found regarding the importance of oral transmission of mycobacteria in healthy people, their importance in the immunosuppressed population remains uncertain.(AU)

Mycobacterium bovis é o agente da tuberculose bovina, doença que acomete o rebanho em todo território brasileiro e é uma negligenciada zoonose transmitida pelo leite e seus derivados. Este trabalho avaliou a presença de M. bovise outras micobactérias, em queijo minas meia-cura, obtidos em feiras-livres na cidade de São Paulo, entre os anos de 2012 e 2013. As amostras (n = 133) foram descontaminadas pelo método HPC (hexa-cetyl-pyridinium chloride) e semeadas em meio Stonebrink Leslie. Os isolados foram submetidos à identificação molecular por PCR TB multiplex, pesquisando-se o gene 16S rRNA, e ao sequenciamento nucleotídico. Dezesseis amostras (12%) possuiam 26 colônias sugestivas de Mycobacterium spp, mas nenhuma delas pertencia aos complexos Mycobacterium tuberculosis, Mycobacterium avium e Mycobacterium intracellulare. A análise filogenética mostrou que todas as amostras estavam agrupadas em clados que incluem apenas micobactérias não tuberculosas (MNT), sendo que algumas possuiam proximidade com sequências obtidas de Mycobacterium novocastrense (3 sequências), Mycobacterium hosaticum(1 sequência) e Mycobacterium elephantis (2 sequências). Embora no momento não haja evidência epidemiológica da importância da transmissão oral das micobactérias pra indivíduos saudáveis, sua importância na população imunossuprimida ainda é incerta.(AU)

Micobacteriosis identificadas en el Laboratorio Nacional de Referencia de Colombia entre 2012 y 2016 / Mycobacterioses identified in the National Reference Laboratory of Colombia from 2012 to 2016

Introducción. En los últimos años se ha observado un aumento en la prevalencia de micobacteriosis ocasionadas por micobacterias no tuberculosas, las cuales hoy se consideran como agentes patógenos emergentes. Su presencia depende de varios factores, como los antecedentes clínicos, el estado de salud de la persona afectada y la presencia de estos microorganismos en el agua, el suelo y los animales, entre otros. Objetivo. Describir las micobacteriosis identificadas en el Laboratorio Nacional de Referencia de Micobacterias del Instituto Nacional de Salud, entre 2012 y 2016. Materiales y métodos. Se hizo un análisis retrospectivo que incluyó 273 pacientes con micobacteriosis. Las variables analizadas fueron el tipo de micobacteriosis, el agente etiológico y los factores de riesgo asociados. Resultados. El 57,1 % de los casos presentó micobacteriosis pulmonar, el 26 %, cutánea, el 10,6 %, diseminada, y el 2,6 %, linfática. La comparación entre la forma pulmonar y la extrapulmonar evidenció que el complejo Mycobacterium avium se presenta con mayor frecuencia en las micobacteriosis pulmonares, en tanto que M. abscessus fue más frecuente en las extrapulmonares. Los pacientes con micobacteriosis pulmonar presentaban antecedentes de tuberculosis con mayor frecuencia que aquellos con las formas extrapulmonares. Conclusión. Estos hallazgos resaltan la importancia del diagnóstico diferencial entre las especies del complejo M. tuberculosis y las micobacterias no tuberculosas, ya que estas últimas son resistentes genéticamente a los fármacos convencionales contra la tuberculosis.

Introduction: In recent years, there has been an increase in the prevalence of mycobacterioses caused by non-tuberculous mycobacteria, which are considered as emerging pathogens. Their presence depends on several factors such as the clinical history, the health status of the affected person, and the presence of these microorganisms in the water, the soil, and the animals, among others. Objective: To describe the mycobacteria and the etiological agent identified in isolates received at the Laboratorio Nacional de Referencia de Micobacterias of the Instituto Nacional de Salud between 2012 and 2016. Materials and methods: We conducted a retrospective analysis of samples from 273 patients with mycobacterioses. We analyzed the following variables: mycobacteriosis type, etiological agent, and associated predisposing factors. Results: 57.1% of the cases presented pulmonary mycobacteriosis; 26%, cutaneous; 10.6%, disseminated, and 2.6%, lymphatic. We found the Mycobacterium avium complex more frequently in pulmonary mycobacteriosis, while M. abscessus was more frequent in the extrapulmonary types of the disease. Patients with pulmonary mycobacteriosis had a history of tuberculosis more frequently than those with extrapulmonary forms. Conclusion: These findings highlight the importance of the differential diagnosis between M. tuberculosis complex species and non-tuberculous mycobacteria since the latter are genetically resistant to conventional antituberculosis drugs.

Aislamiento y caracterización molecular de micobacterias no tuberculosas en el sistema de distribución de agua en un hospital de lima (perú) / Isolation and molecular characterization of nontuberculous mycobacteria in the water distribution system in a hospital of lima (perú)

RESUMEN Introducción: Las infecciones por micobacterias pueden causar lesiones cutáneas y pulmonares; las micobacterias pueden hallarse en fuentes de agua intrahospitalarias, pudiendo llegar a los pacientes inmunosuprimidos y provocar enfermedades severas. Objetivo: Aislar y caracterizar micobacterias no tuberculosas en el sistema de distribución de agua en un hospital de Lima. Materiales y métodos: Se aislaron las micobacterias en medios convencionales a base de huevo; y se emplearon pruebas bioquímicas y herramientas moleculares como la reacción en cadena de la polimerasa ―PCR― y secuenciación para su identificación. Para el análisis de secuenciación se empleó el GenBank y para el árbol filogenético se utilizó MEGA 6. Resultados: Fue posible el aislamiento de bacilos ácido alcohol resistentes en muestras de agua potable fría, aunque no en agua caliente del hospital. Se aislaron e identificaron varias especies de micobacterias no tuberculosas en las muestras de agua, siendo el 100 % de crecimiento rápido, estas fueron: Mycobacterium canariasense; M. frederiksbergense; M. mucogenicum; Mycobacterium fortuitum y Mycobacterium chelonae. Conclusiones: Esta es la primera vez que se aíslan micobacterias en agua potable de un hospital en Perú. Se concluye que la existencia de micobacterias en el agua del hospital podría ser fuente potencial de brotes nosocomiales, por lo que debería tenerse en cuenta su estudio periódicamente.

ABSTRACT Introduction: Mycobacterial infections can cause skin and lung lesions. Mycobacteria can be found in intra-hospital water sources which can reach immuno-suppressed patients and cause severe disease. Objective: To isolate and characterize non-tuberculous mycobacteria in the water distribution system in a hospital in Lima. Materials and Methods: Mycobacteria were isolated in conventional culture egg-based media and biochemical tests and molecular tools such as polymerase chain reaction (PCR) and sequencing were used for their identification. The GenBank was used for sequencing analysis and MEGA 6 was used for the phylogenetic tree. Results: Isolation of acid-fast bacilli was possible in samples of cold drinking water, although not in the hospital hot water. Several species of non-tuberculous mycobacteria were isolated and identified in the water samples being a 100% of rapid growth such as Mycobacterium canariasense, M. frederiksbergense, Mycobacterium fortuitum, Mycobacterium chelonae, and M. mucogenicum. Conclusions: This is the first time that mycobacteria are isolated in drinking water at a hospital in Perú. It is concluded that the existence of mycobacteria in hospital water could be a potential source of nosocomial outbreaks and should be analyzed periodically.

Preliminary Study on Drug Susceptibility Profile and Resistance Mechanisms to Macrolides of Clinical Isolates of Non-tuberculous Mycobacteria from China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Macrolide susceptibility and drug resistance mechanisms of clinical non-tuberculous mycobacteria (NTM) isolates were preliminarily investigated for more accurate diagnosis and treatment of the infection in China.</p><p><b>METHODS</b>Four macrolides, including clarithromycin (CLAR), azithromycin (AZM), roxithromycin (ROX), and erythromycin (ERY), were used to test the drug susceptibility of 310 clinical NTM isolates from six provinces of China with the broth microdilution method. Two resistance mechanisms, 23S rRNA and erm, were analyzed with nucleotide sequence analysis.</p><p><b>RESULTS</b>Varied effectiveness of macrolides and species-specific resistance patterns were observed. Most Mycobacterium abscessus subsp. massiliense were susceptible and all M. fortuitum were highly resistant to macrolides. All the drugs, except for erythromycin, exhibited excellent activities against slow-growing mycobacteria, and drug resistance rates were below 22.2%. Only four highly resistant strains harbored 2,058/2,059 substitutions on rrl and none of other mutations were related to macrolide resistance. G2191A and T2221C on rrl were specific for the M. abscessus complex (MABC). Seven sites, G2140A, G2210C, C2217G, T2238C, T2322C, T2404C, and A2406G, were specifically carried by M. avium and M. intracellulare. Three sites, A2192G, T2358G, and A2636G, were observed only in M. fortuitum and one site G2152A was specific for M. gordonae. The genes erm(39) and erm(41) were detected in M. fortuitum and M. abscessus and inducible resistance was observed in relevant sequevar.</p><p><b>CONCLUSION</b>The susceptibility profile of macrolides against NTM was demonstrated. The well-known macrolide resistance mechanisms, 23S rRNA and erm, failed to account for all resistant NTM isolates, and further studies are warranted to investigate macrolide resistance mechanisms in various NTM species.</p>

Cuando la baciloscopía positiva no es tuberculosis. A propósito de un caso y breve review de la literatura / When smear positive is not tuberculosis. About a case and brief review of the literature

El método gold standar para el diagnóstico de la tuberculosis (TB) es el cultivo en medio sólido de Lowenstein-Jensen. Dado el alto costo y los requerimientos de infraestructura y personal entrenado que exige este método, tanto el programa nacional, como las recomendaciones de la Organización Mundial de la Salud (OMS), establecen que una baciloscopía positiva (BAAR +) confirma el diagnóstico de TB. Si bien el cultivo amplía la sensibilidad diagnóstica, tipifica los bacilos, y permite realizar pruebas de sensibilidad, no es un requisito operativo para la definición de confirmación bacteriológica de TB. En Argentina, el 1% de las BAAR (+) corresponden a otras etiologías3. Presentamos un caso comprendido en ese 1%, en el cual mostramos los problemas a los que se enfrenta un paciente (fundamentalmente demora diagnóstica y exposición innecesaria a drogas potencialmente tóxicas) cuando tiene un diagnóstico de TB de acuerdo con los stándares nacionales e internacionales y sin embargo no es TB.

The method gold standard for the diagnosis of tuberculosis (TB) is the culture in Lowenstein-Jensen’s solid way. In view of the high cost and the requirements of infrastructure and trained personnel that demands this method, both the national program, and the recommendations of the World Health Organization (WHO), they establish that a smear-positive confirms TB’s diagnosis. In addition, the culture increases the diagnostic sensitivity, typifies the bacillus and allows the sensitivity tests to be performed, but it is not an operative requirement for the definition of TB’s bacteriological confirmation. In Argentina, 1% of the BAAR (+) are due to other etiologies3. We present a case included in that 1%, in which we show the problems that a patient faces (basically diagnostic delay and unnecessary exposure to potentially toxic drugs) when it has TB’s diagnosis of agreement to the national and international standards and nevertheless it is not TB.