Pay attention to the diagnosis and treatment of Mycobacterium avium-intracellulare complex infection / 中华临床感染病杂志

Mycobacterium avium- intracellulare complex is the term of a group of slow growing nontuberculous mycobacterium related to human infections, which has received more and more attention in recent years, and become an important public health issue. This article reviews the progress on clinical diagnosis and treatment of the infections caused by Mycobacterium avium- intracellulare complex.

Distribution and drug resistance of nontuberculous mycobacteria / 公共卫生与预防医学

Objective To analyze the distribution characteristics and drug resistance of nontuberculous mycobacteria(NTM),and to provide guidance for the selection of targeted agents in clinical treatment. Methods The clinical data of inpatients in our hospital from April 2019 to February 2021 were collected,the culture and strain identification of non tuberculosis mycobacteria were carried out,the drug sensitivity test of anti tuberculosis drugs was carried out,and the drug resistance of non tuberculosis mycobacteria to first-line anti tuberculosis drugs was analyzed. Results A total of 1 326 strains of mycobacterium were isolated,including 1 154(87.03%)strains of mycobacterium tuberculosis and 172(12.97%)strains of non-mycobacterium tuberculosis.Nine species of nontuberculous mycobacteria were detected,including slow-growing mycobacteria such as Mycobacterium kansasii and Mycobacterium avium-intracellulare complex,belonging to Groups I-III,and fast-growing mycobacteria such as Mycobacterium chelonae and Mycobacterium smegmatis,belonging to Group IV. Among them , Mycobacterium avium-intracellulare complex and Mycobacterium chelonae were dominant,accounting for 26.16%and 36.63%,respectively.Drug susceptibility tests showed that the resistance rate of Mycobacterium avium-intracellulare complex to streptomycin was 100.00%,the drug resistance rate of Mycobacterium chelonae to isoniazid,rifampicin and streptomycin was 100.00%,and the drug resistance rate of Mycobacterium smegmatis and Mycobacterium abscessus to most antibacterial drugs was 100.00%.The resistance rate of major NTM bacteria to clarithromycin was relatively low.There was no statistically significant difference in the susceptibility rates of slow and fast-growing mycobacteria to isoniazid and clarithromycin(P>0.05) ; The susceptibility rates of slow-growing mycobacteria to amikacin,clarithromycin and rifambutin were 62.86%,92.86%and 72.86%,all above 50.00%.The susceptibility rate of the fast-growing mycobacteria to clarithromycin was also more than 50.00%,being 87.25%.The susceptibility rate of slow-growing mycobacteria to other antibiotics was higher than that of fast-growing mycobacteria(P<0.05).The drug resistance of Mycobacterium tuberculosis to first-line anti tuberculosis drugs was significantly lower than that of non Mycobacterium tuberculosis(P<0.05). Conclusion Non-tuberculous mycobacteria have high drug resistance,especially fast-growing mycobacteria,so drug susceptibility tests are of great value in clinical treatment.

Effect of coexisting advanced extrapulmonary solid cancer on progression of Mycobacterium avium complex lung disease / Efeito da coexistência de câncer sólido extrapulmonar avançado na progressão da doença pulmonar por complexo Mycobacterium avium

ABSTRACT Objective: Although Mycobacterium avium complex (MAC) lung disease has been shown to be associated with lung cancer and hematologic malignancies, there have been few studies of its relationships with other types of cancer. The aim of this study was to assess the effect that coexisting advanced extrapulmonary solid tumors have on the progression of MAC lung disease. Methods: This was a retrospective study of patients diagnosed with MAC lung disease, on the basis of the American Thoracic Society (ATS) criteria, between October of 2005 and March of 2019. The patients were divided into three groups: those with advanced-stage cancer (A-SC group); those with early-stage cancer (E-SC group); and those without cancer (control group). Progression of MAC lung disease was defined as exacerbation seen on imaging. Patient characteristics and the time to progression were compared among the three groups. Results: A total of 286 patients met the ATS diagnostic criteria for MAC lung disease, and 128 of those were excluded. Of the remaining 158 patients, 20 (7.0%) were in the A-SC group, 36 (12.6%) were in the E-SC group, and 102 (35.7%) were in the control group. The median time to progression in the A-SC, E-SC, and control groups was 432, 3,595, and 2,829 days, respectively (p < 0.01). A proportional hazards model showed that the significant predictors of MAC lung disease progression were advanced-stage cancer (hazard ratio [HR] = 6.096; 95% CI: 2.688-13.826; p < 0.01), cavitary lesions (HR = 2.750; 95% CI: 1.306-5.791; p < 0.01), and a high Nodule-Infiltration-Cavity-Ectasis score (HR = 1.046; 95% CI: 1.004-1.091; p = 0.033). Conclusions: A coexisting advanced extrapulmonary solid tumor could hasten the progression of MAC lung disease.

RESUMO Objetivo: Embora tenha sido demonstrado que a doença pulmonar por Mycobacterium avium complex (MAC, complexo M. avium) está associada a câncer de pulmão e neoplasias hematológicas, há poucos estudos sobre sua relação com outros tipos de câncer. O objetivo deste estudo foi avaliar o efeito da coexistência de tumores sólidos extrapulmonares avançados na progressão da doença pulmonar por MAC. Métodos: Estudo retrospectivo de pacientes diagnosticados com doença pulmonar por MAC, segundo os critérios da American Thoracic Society (ATS), entre outubro de 2005 e março de 2019. Os pacientes foram divididos em três grupos: grupo câncer em estágio avançado (grupo CEA), grupo câncer em estágio inicial (grupo CEI) e grupo sem câncer (grupo controle). Progressão da doença pulmonar por MAC foi definida como exacerbação observada em exame de imagem. As características dos pacientes e o tempo para progressão foram comparados entre os três grupos. Resultados: Um total de 286 pacientes preencheu os critérios diagnósticos da ATS para doença pulmonar por MAC, sendo 128 deles excluídos. Dos 158 pacientes restantes, 20 (7,0%) eram do grupo CEA, 36 (12,6%), do grupo CEI e 102 (35,7%), do grupo controle. A mediana de tempo para progressão nos grupos CEA, CEI e controle foi de 432, 3.595 e 2.829 dias, respectivamente (p < 0,01). Um modelo de riscos proporcionais demonstrou que os preditores significativos de progressão da doença pulmonar por MAC foram câncer em estágio avançado (razão de risco [RR] = 6,096; 95%IC: 2,688-13,826; p < 0,01), lesões cavitárias (RR = 2,750; 95%IC: 1,306-5,791; p < 0,01) e pontuação alta no sistema Nódulo-Infiltração-Cavidade-Ectasia (RR = 1,046; 95%IC: 1,004-1,091; p = 0,033). Conclusões: A coexistência de tumor sólido extrapulmonar avançado poderia acelerar a progressão da doença pulmonar por MAC.

Pulmonary mycobacterium avium complex disease complicated by cancer: an 11-year survey at a single-center / Journal of Rural Medicine

Objective: Pulmonary mycobacterium avium complex (MAC) disease is increasing significantly worldwide. Several studies have investigated the clinical features of pulmonary MAC disease in the setting of cancer. Here, we aimed to clarify the clinical characteristics of patients with cancer with recent onset of pulmonary MAC disease and the effect of cancer on the onset of this disease.Patients and Methods: Of the 323 consecutive Japanese patients newly diagnosed with pulmonary MAC disease at Jichi Medical University Hospital between and 2006–2017, we retrospectively reviewed 79 consecutive patients with cancer.Results: Seventeen patients had lung cancer (21.0%), while 62 had non-lung cancer. Of the 17 patients with lung cancer, 16 had adenocarcinoma of which 10 had stage I to III disease; 8 of the 10 patients had not received chemotherapy. Sixteen patients with lung cancer had a MAC infection in the ipsilateral lung. Notably, 9 of the 11 lung cancer patients who did not undergo surgery had a MAC infection in the affected lobe. Of the 39 patients with the most common types of non-lung cancer (14 had gastric cancer, 13 had colorectal cancer, and 12 had breast cancer), 22 had stage I to III disease, and 18 of these 22 had not received chemotherapy.Conclusion: Lung cancer may act as a local factor contributing to the onset of pulmonary MAC disease in the ipsilateral lung. However, the underlying mechanism by which a history of cancer might affect the onset of pulmonary MAC disease remains unclear. Further investigation into this mechanism is needed.

Serodiagnóstico de Paratuberculosis en bovinos del municipio de Sogamoso, Boyacá (Colombia) / Serodiagnosis of Paratuberculosis in cattle of the municipality of Sogamoso, Boyacá (Colombia) / Serodiagnóstico da paratuberculose no gado do municipio de Sogamoso, Boyacá (Colômbia)

RESUMEN La Paratuberculosis Bovina (PTB) o Enfermedad de Johne, es una infección del tracto gastrointestinal causada por Mycobacterium avium, subespecie paratuberculosis (Map), que se caracteriza por generar enteritis granulomatosa crónica y linfadenitis en rumiantes. La preocupación más relevante en relación con la importancia de la PTB es su posible vínculo con la Enfermedad de Crohn (EC) en humanos, sin embargo, esta asociación aún está bajo investigación. Se determinó la seroprevalencia de PTB en el municipio de Sogamoso (Boyacá), donde se recolectaron 604 muestras de sangre, cuyo suero fue procesado mediante la técnica de ELISA indirecta con el kit comercial PARACHEK® 2 KIT (Prionics, Suiza). La seroprevalencia fue de 10,9% (66/604), donde el grupo etario de 2 a 3 años y la raza Jersey fueron los de mayor seroprevalencia. Se encontró asociación estadística significativa (p≤0,05) entre la edad de los individuos evaluados y el suministro de concentrado. La seroprevalencia encontrada indica que se está produciendo una transmisión activa de la enfermedad y que las medidas de control disponibles no están siendo llevadas a cabo o no son lo suficientemente efectivas.

ABSTRACT Bovine Paratuberculosis (BPT), or Johne's Disease, is an infection of the gastrointestinal tract caused by Mycobacterium avium, subspecies paratuberculosis (Map), which is characterized by chronic granulomatous enteritis and lymphadenitis in ruminants. The most relevant concern regarding the importance of BPT is its possible link to Crohn's disease (CD) in humans, however this association is still under investigation. The seroprevalence of BPT was determined in the municipality of Sogamoso (Boyacá), where 604 blood samples were collected, their serum was processed by the indirect ELISA technique with the commercial PARACHEK® 2 KIT (Prionics, Switzerland), following the manufacturer's instructions. The seroprevalence was 10,9% (66/604), with the 2 to 3 years age group and the Jersey breed having the highest seroprevalence. A significant statistical association was found (p≤0,05) with the age of the individuals tested and the supply of concentrate. The seroprevalence found indicates that active transmission of the disease is taking place, and that the available control measures are not being carried out or are not effective enough.

RESUMO A Paratuberculose Bovina (PTB) ou Doença de Johne é uma infecção do trato gastrointestinal causada pela Mycobacterium avium subespécie paratuberculosis (Map), caracterizada por gerar enterite granulomatosa crónica e linfadenite em ruminantes. A preocupação mais relevante em relação à importância do PTB é seu possível vínculo com a Doença de Crohn (DC) em seres humanos, no entanto, essa associação ainda está sob investigação. A soroprevalência do PTB foi determinada no município de Sogamoso (Boyacá), onde foram coletadas 604 amostras de sangue, cujo soro foi processado pela técnica ELISA indireta com o kit comercial PARACHEK® 2 KIT (Prionics, Suíça). A soroprevalência foi de 10,9% (66/604), onde a faixa etária de 2 a 3 anos e a raça Jersey foram as que apresentaram maior soroprevalência. Foi encontrada associação estatisticamente significante (p≤0,05) com a idade dos indivíduos avaliados e o suprimento de concentrado. A soroprevalência encontrada indica que a transmissão ativa da doença está ocorrendo e que as medidas de controle disponíveis não estão sendo realizadas ou não são eficazes o suficiente.

Identificación de especies micobacterianas ambientales u oportunistas en pacientes sintomáticos y con VIH/sida / Identification of environmental or opportunistic mycobacterial species in symptomatic symptomatic and HIV/AIDS patients

El aumento de las infecciones por micobacterias ambientales u oportunistas (MAO) coincide mundialmente con el declive de la infección tuberculosa e incremento de la infección por el virus de inmunodeficiencia humana (VIH). El presente trabajo es un estudio retrospectivo realizado en el Laboratorio Nacional de Referencia-Investigaciones de Tuberculosis/Micobacterias/Lepra (LNRI-TB/Lepra/Micobacterias), del Instituto de Medicina Tropical Pedro Kourí (IPK), La Habana, Cuba, durante el período enero 2014-diciembre 2018. El objetivo de nuestro estudio fue conocer la variabilidad de especies aisladas para establecer un referente actualizado sobre las infecciones causadas por estas. En este trabajo se clasificaron-identificaron 413 cepas procedentes de pacientes sintomáticos; 162 (39.22%) eran aislamientos de pacientes con VIH/sida atendidos en nuestro Hospital Nacional de Referencia a Atención al paciente VIH/sida (IPK), y el resto (n = 251 [60.77%]), procedentes de pacientes inmunocompetentes, incluyendo aislamientos recibidos de los Centros Provinciales de Higiene, Epidemiología, y Microbiología (CPHEM). Las muestras fueron analizadas con las técnicas convencionales establecidas: las pulmonares fueron descontaminadas por el método de Petroff modificado; las extrapulmonares, por el método del ácido sulfúrico al 4%; el cultivo se realizó en medio de Löwenstein-Jensen modificado. Posteriormente se realizó la clasificación-identificación de especies según el esquema fenotípico-bioquímico establecido. Las especies con mayor porcentaje de aislamiento pertenecieron a los Grupos III y IV, complejo Mycobacterium avium-intracellulare (34.14%) y complejo M. fortuitum (20.82%), respectivamente. Estos resultados permitirán conocer la prevalencia de estas especies en nuestro país, reafirmando la importancia diagnóstica de estos microorganismos para aplicar tratamiento específico, sobre todo en pacientes con factores de riesgo, en quienes es más probable la diseminación de la infección.

The increase in infections by environmental or opportunistic mycobacteria (MAO) coincides worldwide with the decline in tuberculosis infection and an increase in infection by the human immunodeficiency virus (HIV). The present work is a retrospective study carried out at the National Reference Laboratory-Tuberculosis/Mycobacterial/Leprosy Research (LNRI-TB / Leprosy / Mycobacteria), of the Pedro Kourí Institute of Tropical Medicine (IPK), La Habana, Cuba, during the period January 2014-December 2018. The objective of our study was to know the variability of isolated species to establish an updated reference on the infections caused by MAO. In this study, 413 strains from symptomatic patients were classified and identified; 162 (39.22%) were isolates from patients with HIV/AIDS treated at our National Hospital of Reference for Attention to HIV/AIDS patients (IPK), and the remaining (n=251 [60.77%]), from immunocompetent patients, including isolates received from the Provincial Centers of Hygiene, Epidemiology, and Microbiology (CPHEM). The samples were analyzed with the established conventional techniques: the lung samples were decontaminated by the modified Petroff method; the extrapulmonary, by the 4% sulfuric acid method; the culture was carried out in modified Löwenstein-Jensen medium. Subsequently, the classification-identification of species was carried out according to the established phenotypic-biochemical scheme. The species with the highest percentage of isolation belonged to Groups III and IV, Mycobacterium avium-intracellulare complex (34.14%), and M. fortuitum complex (20.82%), respectively. These results will allow us to know the prevalence of these species in our country, emphasizing the diagnostic importance of these microorganisms and thus apply a specific treatment, especially in patients with risk factors, in whom the spread of the infection is more likely

Enfermedad pulmonar por Mycobacterium intracellulare en una paciente inmunocompetente: reporte de un caso en el Perú / Pulmonary disease by mycobacterium intracellulare in an immunocompetent patient: Report of a case in Peru

RESUMEN Presentamos una paciente inmunocompetente cuya enfermedad comenzó a los 49 años con tos, seguida de esputo purulento y hemoptoico, por lo que se diagnosticó bronquiectasias. Tres años después, luego de hemoptisis, le practicaron segmentectomía medial del lóbulo medio y quedó asintomática por meses. Al encontrarse tuberculosis en el informe de patología fue tratada con 4HREZ2R2H2. Cinco años después su BK fue 2+ recibiendo un nuevo esquema de 4HREZ2R2H2, con lo que no logro negativizar declarándose el fracaso al tratamiento. Al hallar en la genotipificación de su cultivo Mycobacterium intracellulare, la paciente recibió azitromicina, moxifloxacina y etambutol, hubo mejoría, pero abandonó el tratamiento a los ocho meses; lo reinició 18 meses después, junto con tratamiento para la depresión y el reflujo gastroesofágico. Al mes la paciente estuvo asintomática, pero hizo reacción dérmica a la moxifloxacina y se la reemplazó por amikacina. Salió de alta y al año estuvo curada, a los 64 años de edad.

ABSTRACT We present the case of an immunocompetent patient whose illness began at age 49 with a cough, followed by purulent and hemoptoic sputum; bronchiectasis was diagnosed. Three years later, after hemoptysis, she underwent medial segmentectomy of the middle lobe and was asymptomatic for months. When tuberculosis was found in the pathology report, she was treated with 4HREZ2R2H2. Five years later her BK was 2+, thus receiving a new scheme of 4HREZ2R2H2, which did not succeed in obtaining negative results and the treatment was declared as a failure. After genotyping her Mycobacterium intracellulare culture, the patient received azithromycin, moxifloxacin and ethambutol. There was improvement, but she abandoned the treatment at 8 months; she restarted it 18 months later, along with treatment for depression and gastroesophageal reflux. After one month the patient was asymptomatic, but she had a dermal reaction to moxifloxacin which was replaced with amikacin. One year later, she was cured and discharged, at the age of 64.

Nontuberculous mycobacterial infection in a tertiary care center in Mexico, 2001-2017

ABSTRACT Introduction: Nontuberculous mycobacteria (NTM) comprise several pathogens with a complex profile of virulence, diverse epidemiological and clinical patterns as well as host specificity. Recently, an increase in the number of NTM infections has been observed; therefore, the objective of this study was to evaluate the clinical characteristics and outcomes of these infections. Methods: We included patients with NTM infections between 2001-2017 and obtained risk factors, clinical features and outcomes; finally, we compared this data between slowly growing (SGM) and rapidly growing mycobacteria (RGM). Results: A total of 230 patients were evaluated, 158 (69%) infected and 72 (31%) colonized/pseudoinfected. The average annual incidence in the first 11 years of the study was 0.5 cases per 1000 admissions and increased to 2.0 cases per 1000 admissions later on. The distribution of NTM infections was as follows: bloodstream and disseminated disease 72 (45%), lung infection 67 (42%), skin and soft tissue infection 19 (12%). Mycobacterium avium complex was the most common isolate within SGM infections, and HIV-infected patients were the most affected. Within RGM infections, M. fortuitum was the most common isolate from patients with underlying conditions such as cancer, type-2 diabetes mellitus, presence of invasive devices, and use of immunosuppressive therapy. We did not find significant differences in deaths and persistent infections between disseminated SGM infection when compared to disseminated RGM infection (42% vs. 24%, p = 0.22). However, disseminated SGM infection required a longer duration of therapy than disseminated RGM infection (median, 210 vs. 42 days, p = 0.01). NTM lung disease showed no significant differences in outcomes among treated versus non-treated patients (p = 0.27). Conclusions: Our results show a significant increase in the number of Non-tuberculosis-mycobacteria infections in our setting. Patients with slow-growing-mycobacteria infections were mainly persons living with human immunodeficiency virus . Older patients with chronic diseases were common among those with rapidly-growing-mycobacteria infections. For non-tuberculosis-mycobacteria lung infection, antibiotic therapy should be carefully individualized.

Brazilian Green Propolis: Chemical Composition of Essential Oil and Their In Vitro Antioxidant, Antibacterial and Antiproliferative Activities

Abstract Propolis is a resinous substance collected and processed by Apis mellifera from parts of plants, buds and exudates. In Minas Gerais (MG) state, Brazil, green propolis is produced from the collection of resinous substance found in shoot apices of Baccharis dracunculifolia. This paper aims to investigate the chemical composition and in vitro antioxidant, anti-Helicobacter pylori, antimycobacterial and antiproliferative activities of essential oil (EO) from Brazilian green propolis (BGP-EO). The oil showed high antibacterial activity against H. pylori (MIC = 6.25 µg/mL), Mycobacterium avium (MIC = 62.5 µg/mL) and M. tuberculosis (MIC = 64 µg/mL). Its antioxidant activity was evaluated in vitro by both DPPH (IC50 = 23.48 µg/mL) and ABTS (IC50 = 32.18 µg/mL) methods. The antiproliferative activity in normal (GM07492A, lung fibroblasts) and tumor cell lines (MCF-7, HeLa and M059J) was analyzed by the XTT assay. BGP-EO showed inhibition of normal cell growth at 68.93 ± 2.56 µg/mL. Antiproliferative activity was observed against human tumor cell lines, whose IC50 values were 56.17, 66.43 and -65.83 µg/mL for MCF-7, HeLa and M059J cells, respectively. Its major constituents, which were determined by GC-FID and GC-MS, were carvacrol (20.7 %), acetophenone (13.5 %), spathulenol (11.0 %), (E)-nerolidol (9.7 %) and β-caryophyllene (6.2 %). These results showed the effectiveness of BGP-EO as a natural product which has promising biological activities.

Nontuberculous mycobacteria in patients with suspected tuberculosis and the genetic diversity of Mycobacterium avium in the extreme south of Brazil / Micobactérias não tuberculosas em pacientes com suspeita de tuberculose e a diversidade genética de Mycobacterium avium no extremo sul do Brasil

ABSTRACT Objective: Nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria that are widely distributed in nature and associated with opportunistic infections in humans. The aims of this study were to identify NTM in patients with suspected tuberculosis who presented positive cultures and to evaluate the genetic diversity of strains identified as Mycobacterium avium. Methods: We studied pulmonary and extrapulmonary samples obtained from 1,248 patients. The samples that tested positive on culture and negative for the M. tuberculosis complex by molecular identification techniques were evaluated by detection of the hsp65 and rpoB genes and sequencing of conserved fragments of these genes. All strains identified as M. avium were genotyped using the eight-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat method. Results: We found that NTM accounted for 25 (7.5%) of the 332 mycobacteria isolated. Of those 25, 18 (72%) were M. avium, 5 (20%) were M. abscessus, 1 (4%) was M. gastri, and 1 (4%) was M. kansasii. The 18 M. avium strains showed high diversity, only two strains being genetically related. Conclusions: These results highlight the need to consider the investigation of NTM in patients with suspected active tuberculosis who present with positive cultures, as well as to evaluate the genetic diversity of M. avium strains.

RESUMO Objetivo: As micobactérias não tuberculosas (MNT) são um grupo heterogêneo de bactérias amplamente distribuídas na natureza e relacionadas com infecções oportunistas em seres humanos. Os objetivos deste estudo foram identificar MNT em pacientes com suspeita de tuberculose e culturas positivas e avaliar a diversidade genética de cepas identificadas como Mycobacterium avium. Métodos: Foram estudadas amostras pulmonares e extrapulmonares provenientes de 1.248 pacientes. As amostras que apresentaram resultado positivo em cultura e negativo para o complexo M. tuberculosis na identificação molecular foram avaliadas por meio da detecção dos genes hsp65 e rpoB e de sequenciamento de fragmentos conservados desses genes. Todas as cepas identificadas como M. avium foram genotipadas pelo método mycobacterial interspersed repetitive unit-variable-number tandem-repeat com oito loci. Resultados: Das 332 micobactérias isoladas, 25 (7,5%) eram MNT. Dessas 25, 18 (72%) eram M. avium, 5 (20%) eram M. abscessus, 1 (4%) era M. gastri e 1 (4%) era M. kansasii. As 18 cepas de M. avium apresentaram alta diversidade, e apenas duas eram geneticamente relacionadas. Conclusões: Esses resultados mostram a necessidade de considerar a investigação de MNT em pacientes com suspeita de tuberculose ativa e culturas positivas e de avaliar a diversidade genética de cepas de M. avium.

Prevalence of Opportunistic Pathogens and Diversity of Microbial Communities in the Water System of a Pulmonary Hospital / 生物医学与环境科学（英文）

Objective@#Our objective was to investigate the occurrence of opportunistic pathogens and characterize the bacterial community structures in the water system of a pulmonary hospital.@*Methods@#The water samples were collected from automatic and manual faucets in the consulting room, treatment room, dressing room, respiratory ward, and other non-medical rooms in three buildings of the hospital. Quantitative polymerase chain reaction was used to quantify the load of several waterborne opportunistic pathogens and related microorganisms, including spp., spp., and . Illumina sequencing targeting 16S rRNA genes was performed to profile bacterial communities.@*Results@#The occurrence rates of spp., spp., and were 100%, 100%, and 76%, respectively in all samples. Higher occurrence rates of were observed in the outpatient service building (building 1, 91.7%) and respiration department and wards (building 2, 80%) than in the office building (building 3), where no was found. were more abundant in automatic faucets (average 2.21 × 10 gene copies/L) than in manual faucets (average 1.03 × 10 gene copies/mL) ( < 0.01). , , , , , and were the dominant bacterial phyla. Disinfectant residuals, nitrate, and temperature were found to be the key environmental factors driving microbial community structure shifts in water systems.@*Conclusion@#This study revealed a high level of colonization of water faucets by opportunistic pathogens and provided insight into the characteristics of microbial communities in a hospital water system and approaches to reduce risks of microbial contamination.

Treatment Outcomes after Discontinuation of Ethambutol due to Adverse Events in Mycobacterium avium Complex Lung Disease

BACKGROUND: Long-term administration of ethambutol (EMB) for Mycobacterium avium complex lung disease (MAC-LD) sometimes leads to permanent discontinuation of EMB due to various adverse events. This study aimed to investigate treatment outcomes after discontinuation of EMB.METHODS: Among patients diagnosed with MAC-LD between January 2001 and December 2014, 508 patients whose treatment was initiated with standard regimen until May 2018 were enrolled at a tertiary referral center in Korea. Of these 508 patients, 60 (11.8%) discontinued EMB due to various adverse effects. Among these 60 patients, treatment outcomes were analyzed for 44 patients by comparing their outcomes with those of matched subjects who received the standard treatment regimen without EMB discontinuation.RESULTS: The mean age of the 60 patients who discontinued EMB was 64.4 years. Ocular toxicity was the most common cause of discontinuation of EMB (75.0%, 45/60). The mean duration of EMB administration before its discontinuation was 7.0 ± 4.6 months. The treatment failure rate of the 44 patients with EMB discontinuation analyzed for treatment outcome was 29.6%, which was higher than that of the matched patients who received the standard regimen (18.3%), although the difference was not significant (P = 0.095). Of these 44 patients, EMB was substituted with later-generation fluoroquinolone in 23 patients, and the treatment failure rate of these 23 patients was significantly higher than that of the matched patients who received the standard regimen (39.1% vs. 19.3%, P = 0.045).CONCLUSION: These findings suggest that treatment outcomes are unsatisfactory in patients with MAC-LD who discontinue EMB owing to adverse events. Notably, there was a statistically significant high failure rate in patients who were prescribed fluoroquinolone to replace EMB.

Molecular isolation and identification of Mycobacterium avium subsp. hominissuis in Didelphis virginiana from Hidalgo, Mexico

Objective: To isolate and identify the exact species of the genus Mycobacterium from Didelphis (D.) virginiana, and the direct implications of this bacterium to public health and veterinary medicine. Methods: Thirty-one D. virginiana were captured and necropsied in Hidalgo, Mexico. Tissue samples were collected to culture mycobacteria present and examine individual specimens' histopathology. Mycobacterium identification was obtained through the application of amplification and sequencing of 16S rDNA techniques. Results: Three strains were isolated and identified as Mycobacterium (M.) avium subsp. hominissuis by utilizing M. avium complex- specific primers. Granulomatous lesions were observed in the subpleural zone (granuloma grade Π ) and bronchial (granuloma grade I ) of the lungs of D. virginiana with positive isolation. Conclusions: Three strains of M. avium subsp. hominissuis, from lung tissue samples of D. virginiana were identified. This subspecies of M. avium has important implications in public health and veterinary medicine.

Molecular isolation and identification of Mycobacterium avium subsp. hominissuis in Didelphis virginiana from Hidalgo, Mexico

Objective: To isolate and identify the exact species of the genus Mycobacterium from Didelphis (D.) virginiana, and the direct implications of this bacterium to public health and veterinary medicine. Methods: Thirty-one D. virginiana were captured and necropsied in Hidalgo, Mexico. Tissue samples were collected to culture mycobacteria present and examine individual specimens' histopathology. Mycobacterium identification was obtained through the application of amplification and sequencing of 16S rDNA techniques. Results: Three strains were isolated and identified as Mycobacterium (M.) avium subsp. hominissuis by utilizing M. avium complex- specific primers. Granulomatous lesions were observed in the subpleural zone (granuloma grade Π ) and bronchial (granuloma grade I ) of the lungs of D. virginiana with positive isolation. Conclusions: Three strains of M. avium subsp. hominissuis, from lung tissue samples of D. virginiana were identified. This subspecies of M. avium has important implications in public health and veterinary medicine.

A prospective study of non-tuberculous mycobacterial disease among tuberculosis suspects at a tertiary care centre in north India

Background & objectives: The burden of non-tuberculous mycobacterial (NTM) disease is increasing worldwide. The disease shares clinicoradiological features with tuberculosis (TB), Nocardia and several fungal diseases, and its diagnosis is frequently delayed. The present study was performed to determine the frequency of NTM disease among TB suspects in a tertiary care centre in north India. Methods: In this prospective study, mycobacterial culture isolates from pulmonary and extrapulmonary specimens among TB suspects were tested with immunochromatographic assay (ICA). All ICA-negative isolates were considered as NTM suspects and further subjected to 16S-23S rRNA internal transcribed spacer gene sequencing for confirmation and species identification. Patients with active disease were treated with drug regimen as per the identified NTM species. Follow up of patients was done to determine clinical, radiological and microbiological outcomes. Results: Of the 5409 TB suspects, 42 (0.77%) were diagnosed with NTM disease. Patients with active disease consenting for treatment were treated and followed up. Thirty four patients had NTM pulmonary disease (NTM-PD) and the remaining eight had extrapulmonary NTM (EP-NTM) disease. Mycobacterium intracellulare and M. abscessus, respectively, were most frequently isolated from NTM-PD and EP-NTM patients. Fifteen NTM-PD and seven EP-NTM patients successfully completed the treatment. Ten patients died due to unrelated causes, five were lost to follow up and another four declined the treatment. Interpretation & conclusions: Our study showed that the frequency of NTM disease was low among TB suspects at a large tertiary care centre in north India and this finding was similar to other Indian studies. More studies need to be done in other parts of the country to know the geographical variation in NTM disease, if any.

Identificación y estudio de susceptibilidad antimicrobiana en cepas de mycobacterium spp. aisladas en un hospital de alta complejidad / Identification and study of antimicrobial susceptibility of isolated mycobacterium spp. strains in a hospital of high complexity

El género Mycobacterium se encuentra asociado a una cantidad importante de patologías, donde la tuberculosis destaca dentro de los principales problemas de salud pública a nivel mundial y nacional. Esta se agudiza con el incremento en la resistencia antimicrobiana y, por ello, la pesquisa de micobacterias contempla un pilar fundamental en el diagnóstico de patologías infecciosas de importancia clínica. Por lo tanto, el objetivo fue describir las principales especies de micobacterias aisladas y su patrón de susceptibilidad a partir de muestras clínicas procesadas en el Hospital Dr. Hernán Henríquez Aravena durante el año 2012. Se realizó un estudio descriptivo retrospectivo, en donde se utilizaron los resultados de 7023 baciloscopías procesadas en el Laboratorio Clínico del Hospital Dr. Hernán Henríquez Aravena de Temuco el año 2012. Todas las baciloscopías fueron analizadas y solicitadas según criterios establecidos por el Instituto de Salud Pública de Chile, comprendiendo muestras de expectoración y no expectoración. De las 7023 baciloscopías realizadas, 100 resultaron ser positivas para Mycobacterium. De 21 cepas enviadas al Instituto de Salud Pública de Chile para identificación, 19 cepas corresponden al complejo Mycobacterium tuberculosis y dos a Mycobacterium avium intracelular. En el estudio de sensibilidad, se encontró resistencia a estreptomicina e isoniazida en 13,3 % de las expectoraciones. De acuerdo a lo establecido por la literatura, más del 90 % pertenecen a Mycobacterium tuberculosis, mientras que, de las micobacterias no tuberculosas sólo se aislaron Mycobacterium avium intracelular. Los antimicrobianos con mayores niveles de resistencia son estreptomicina e isoniazida.

The genus Mycobacterium is associated with a significant number of pathologies, where tuberculosis stands out among the main public health problems worldwide and nationally. This is exacerbated by the increase in antimicrobial resistance and, therefore, the research of mycobacteria contemplates a fundamental pillar in the diagnosis of infectious pathologies of clinical importance. Therefore, the aim was to describe the main species of isolated mycobacteria and their susceptibility pattern from clinical samples processed at the Dr. Hernán Henríquez Aravena Hospital during 2012. A retrospective descriptive study was carried out, where the results of 7023 sputum microscopy processed in the Clinical Laboratory of the Dr. Hernán Henríquez Aravena Hospital in Temuco in 2012. All sputum microscopy was analyzed and requested according to criteria established by the Instituto de Salud Pública of Chile, including expectoration and non-sputum samples. Of the 7023-sputum microscopy performed, 100 were positive for Mycobacterium. Of 21 strains sent to the Instituto de Salud Pública of Chile for identification, 19 strains correspond to the Mycobacterium tuberculosis complex and two to intracellular Mycobacterium avium. In the sensitivity study, resistance to streptomycin and isoniazid was found in 13.3 % of the expectorations. According to what is established by the literature, more than 90 % belong to Mycobacterium tuberculosis, while only intracellular Mycobacterium avium was isolated from non-tuberculous mycobacteria. Antimicrobials with higher levels of resistance are streptomycin and isoniazid.

Drug resistance and pathogenic spectrum of patients coinfected with nontuberculous mycobacteria and human-immunodeficiency virus in Chengdu, China / 中华医学杂志(英文版)

Background@#Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.@*Methods@#Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ2) test.@*Results@#Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium–intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was <50 cells/μL (84.7%). Patients were mainly in advanced acquired immunodeficiency syndrome (AIDS) stage. Chest imaging mainly showed patchy shadows (42.4%) and nodules (32.2%), with various degrees of AIDS-defining diseases. The drug resistance of NTM was severe, and the rate of isoniazid resistance (100.0%) was the highest, followed by rifampicin (94.9%), streptomycin (94.9%), ofloxacin (93.2%), and others. Ethambutol (52.5%) and clarithromycin (33.9%) were relatively low. No significant difference was found in the drug resistance rate of NTM strain against nine antituberculosis drugs in 5 years (P > 0.05).@*Conclusions@#The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.

Treatment of Mycobacterium avium Complex Pulmonary Disease / 결핵및호흡기질환

The pathogen Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial pulmonary disease worldwide. The decision to initiate long-term antibiotic treatment is difficult for the physician due to inconsistent disease progression and adverse effects associated with the antibiotic treatment. The prognostic factors for the progression of MAC pulmonary disease are low body mass index, poor nutritional status, presence of cavitary lesion(s), extensive disease, and a positive acid-fast bacilli smear. A regimen consisting of macrolides (clarithromycin or azithromycin) with rifampin and ethambutol has been recommended; this regimen significantly improves the treatment of MAC pulmonary disease and should be maintained for at least 12 months after negative sputum culture conversion. However, the rates of default and disease recurrence after treatment completion are still high. Moreover, treatment failure or macrolide resistance can occur, although in some refractory cases, surgical lung resection can improve treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous risk-benefit analysis in a multidisciplinary setting. New therapies, including clofazimine, inhaled amikacin, and bedaquiline, have shown promising results for the treatment of MAC pulmonary disease, especially in patients with treatment failure or macrolide-resistant MAC pulmonary disease. However, further evidence of the efficacy and safety of these new treatment regimens is needed. Also, a new consensus is needed for treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the treatment of MAC pulmonary disease.

CT characteristics of mycobacterium intracellulare pulmonary diseases: Compared with mycobacterium kansasii, mycobacterium abscess/chelonei pulmonary diseases / 中国医学影像技术

Objective: To explore CT characteristics of mycobacterium intracellulare pulmonary diseases compared with mycobacterium kansasii, mycobacterium abscess/chelonei pulmonary diseases. Methods: CT images of 35 patients with mycobacterium intracellulare pulmonary diseases, 18 with mycobacterium kansasii pulmonary disease and 22 with mycobacterium abscess/chelonei pulmonary disease confirmed by clinical data and laboratory tests were retrospectively analyzed, and imaging findings were evaluated and compared. Results: Mycobacterium intracellulare pulmonary disease involved both lungs (33/35, 94.29%), multiple lobes (18/35, 51.43%) or all lobes (16/35, 45.71%). CT characteristics included cord shadow (34/35, 97.14%), air space consolidation (33/35, 94.29%), centrilobular nodules or tree in bud (32/35, 91.43%), thickened pleura (32/35, 91.43%), ground glass opacity (31/35, 88.57%), traction bronchiectasis (30/35, 85.71%), non-traction bronchiectasis (25/35, 71.43%), nodes (24/35, 68.57%), calcification (24/35, 68.57%) and cavity (23/35, 65.71%). Ground glass opacity was more frequently observed in mycobacterium intracellulare than mycobacterium kansasii (P=0.001) and mycobacterium abscess/chelonei pulmonary disease (P<0.001). Walls of the cavity were thicker in mycobacterium intracellulare than mycobacterium kansasii (P=0.019) and mycobacterium abscess/chelonei pulmonary disease (P=0.024). Calcifications were more frequently observed in mycobacterium intracellulare than in mycobacterium kansasii (P=0.014) and mycobacterium abscess/chelonei pulmonary disease (P=0.007). Conclusion: Compared with mycobacterium kansasii and abscess/chelonei pulmonary disease, CT findings of mycobacterium intracellulare have certain characteristics, which may be helpful to differential diagnosis.

Micobacterias no tuberculosas en pacientes con fibrosis quística / Non-tuberculous mycobacteria in cystic fibrosis patients

In recent years there has been a global increase in nontuberculous mycobacteria isolates, especially in patients with cystic fibrosis. As its clinical and radiological characteristics overlap with other infectious agents, diagnostic guidelines were generated based on evidence from patients who do not present cystic fibrosis. A long-term treatment is necessary, involving multiple antibiotics, and the response rate is low. There are variations in the criteria adopted by different centers with regard to lung transplantation in this group of patients.

En los últimos años se ha producido un aumento a nivel mundial del aislamiento de micobacterias no tuberculosas, especialmente en pacientes con fibrosis quística. Como sus características clínicas y radiológicas se superponen con las de otros agentes infecciosos se generaron orientaciones diagnósticas basadas en evidencia de pacientes que no presentan fibrosis quística. El tratamiento es prolongado, involucra múltiples antibióticos y la tasa de respuesta es baja. Existen variaciones en los criterios adoptados por los distintos centros con respecto al trasplante pulmonar en este grupo de pacientes.