Prevalence of non-tuberculosis mycobacteria among samples deposited from the National Tuberculous Reference Laboratory of Iran (2011-2018)

Objective: To investigate the prevalence of non-tuberculosis mycobacteria (NTM) among the samples deposited from the National Tuberculosis Reference Laboratory of Iran between 2011 and 2018. Methods: The study evaluated the prevalence of NTM among specimens from patients with pulmonary tuberculosis symptoms (n=15 771) deposited at the National Tuberculosis Reference Laboratory of Iran from 2011 to 2018. Detection of Mycobacterium (M.) tuberculosis was based on presence of a 190-bp amplicon from IS6110 insertion sequence using Tb1 and Tb2 primers, and amplicon-negative specimens were tested for NTM and M. tuberculosis (refractory to IS6110 amplification) using restriction fragment length polymorphism PCR of hsp65 amplicon fragment. Results: A total of 7 307 (46.33%) M. tuberculosis and 658 (4.17%) NTM specimens were found, the latter mainly comprising M. abscessus (10.18%), M. avium (2.28%), M. chelonae (8.97%), M. intracellulare (10.49%), M. kansasii (4.71%), and M. simiae (56.08%). Conclusions: As treatment for NTM differs from that for M. tuberculosis, accurate detection of Mycobacterium sp. is of public health significance.

Identification and drug susceptibility testing of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis / 中华流行病学杂志

Objective To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows.Methods The milk sample was collected from a cow with mastitis,which was pretreated with 4％ NaOH and inoculated with L-J medium for Mycobacterium isolation.The positive cultures were initially identified by acid-fast staining and multi-loci PCR,then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA,hsp65,ITS and SodA genes.The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay.Results Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis,which were identified as non-tuberculosis mycobacterium by multi-loci PCR,and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis.The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics,including rifampicin and isoniazid,but they were sensitive to amikacin,moxifloxacin,levofloxacin,ethambutol,streptomycin,tobramycin,ciprofloxacin and linezolid.Conclusions Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique.The results of the study can be used as reference for the prevention and control the infection in cows.

Identification and drug susceptibility testing of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis / 中华流行病学杂志

Objective To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows.Methods The milk sample was collected from a cow with mastitis,which was pretreated with 4％ NaOH and inoculated with L-J medium for Mycobacterium isolation.The positive cultures were initially identified by acid-fast staining and multi-loci PCR,then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA,hsp65,ITS and SodA genes.The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay.Results Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis,which were identified as non-tuberculosis mycobacterium by multi-loci PCR,and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis.The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics,including rifampicin and isoniazid,but they were sensitive to amikacin,moxifloxacin,levofloxacin,ethambutol,streptomycin,tobramycin,ciprofloxacin and linezolid.Conclusions Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique.The results of the study can be used as reference for the prevention and control the infection in cows.

Comparative analysis of CT images of non-tuberculous mycobacterium tuberculosis and multidrug-resistant pulmonary tuberculosis / 天津医药

Objective To study the computed tomograhpy (CT) features of non-tuberculous mycobacteria (NTM) and multidrug-resistant pulmonary tuberculosis (MDR-TB), and to improve the differential diagnosis of the disease. Methods The CT imaging data of 67 patients diagnosed with NTM pulmonary disease (NTM lung disease group) and 103 patients with MDR-TB (MDR-TB group) were selected from January 2010 to December 2015 in our hospital. The imaging findings and differences in lesion location were compared between two groups. Results Lesions of NTM lung disease occurred in the posterior segment of the posterior and posterior lumbar dorsal (Ⅰarea), clustered lobular central nodules, accompanied by bronchiectasis and subpleural thin wall empty, rare bronchial foci. MDR-TB lesions occurred in the middle lobe of the right lung and the upper lobe of the left lung (Ⅱarea). The upper lung of the lungs were patch, nodules and caseous lesions, with thick wall and chronic lung inflammation, showing thick wall empty, pulmonary consolidation, atelectasis, calcification (lung), hilar mediastinal lymph node calcification, lung volume reduction, pleural thickening and pleural effusion. Conclusion Chest CT images are similar in NTM lung disease and MDR-TB, but there are differences. The detailed analysis of image features can provide a basis for clinical differential diagnosis.

First Report in China on the Identification and Drug Sensitivity of Mycobacterium elephantis Isolated from the Milk of a Cow with Mastitis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study.</p><p><b>METHODS</b>Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction (PCR) and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay.</p><p><b>RESULTS</b>Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacterium elephantis (M. elephantis). The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline.</p><p><b>CONCLUSION</b>To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China.</p>

Rapid identification and differentiation of the species of the Mycobacterium chelonae /abscessus complex by hsp65 and rpoB PCR-RFLP / 中国人兽共患病学报

The Mycobacterium chelonae/abscessus (M.chelonae/abscessus) complex belongs to the rapidly growing genus Mycobacterium (RGM).It is one of the most important pathogenic members of Mycobacterium leading to nosocomial infections and outbreaks.It includes members of M.chelonae,M.immnunogenum,M.abscessus,M.massiliense,and M.bolletii.In order to investigate the epidemiological characteristics of the M.chelonae/abscessus complex in China and to conduct the molecular methods for species identification of M.chelonae/abscessus,we collected clinical M.chelonae/abscessus complex strains identified by phenotypic tests.Members were verified by sequencing of 16S rRNA,Species and subspecies were identified by hsp65 and rpoB PCR RFLP methods.In total,27 clinical specimens were identified as Mycobacterium chelonae/abscessus complex by phenotypic tests.16s rRNA gene sequence analysis of all 27 clinical samples shared over 99.7％ similarity with M.chelonae and M.abscessus.Species identification with hsp65 PCR-RFLP and rpoB PCR-RFLP revealed that 18 specimens were M.abscessus and 4 were M.absecces.The remaining 5 samples displayed a pattern that failed to match any previously reported pattern.Thus,this might represent a novel species that is part of the Mycobacterium chelonae/abscessus complex.We identified that a majority of the chronic lung infection in China is caused by the M.chelonae/abscessus complex.Specifically,the M.abscessus species might be the most infectious,while other species in the complex can still cause infection.Interestingly,there may be a novel or previously unidentified species that is a part of the complex.Finally,we show that species identification can be carried out more accurately by combined use of hsp65 and rpoB PCR-RFLP.

Frecuencia de micobacterias ambientales en Chile en el año 2008 / Frequency of environmental mycobacterium in Chile: 2008

Objective: To know the frequency of environmental mycobacterium isolations in Chile in the year 2008. Methods: 600 AFB (acid fast bacilli) positive cultures from 22 laboratories of Tuberculosis Bacteriology of the different Network Health Services that constitute the Tuberculosis Control Program of the country were studied, during four months at 2008. 545 (90.8 percent) were pulmonary and 55 (9.2 percent) extra pulmonary. Acid fast bacilli smears were confirmed by Ziehl Neelsen and identification of mycobacteria species or complex were identified by traditional tests according to Runyon classification and biochemical tests, genetic probes and pattern analysis restriction (PRA). Results: 585 cultures were appropriated for inclusion in the study. In 91.3 percent (n = 534) of the cases Mycobacterium tuberculosis was isolated while 0.3 percent was Mycobacterium bovis subspecie BCG (n = 3) and 8.4 percent (n = 48) corresponded to environmental mycobacterium. Of the latter, Mycobacterium kansasii (2.6 percent), Mycobacterium avium-intracellulare (1.5 percent) and Mycobacterium chelonae (1.0 percent) were the most commonly isolated. Conclusion: According to the figures of this study and comparing them with studies of previous years (1988 and 1998) it is concluded that the number of environmental mycobacterium isolated has been relatively constant during the last decade, as well as the species, more commonly isolated.

Objetivos: Conocer la frecuencia de aislamientos de micobacterias ambientales en Chile en el año 2008. Material y Métodos: Se recibieron 600 cultivos desde 22 laboratorios de Bacteriología de la Tuberculosis de los distintos Servicios de Salud de la red que comprende el Programa de Control de la Tuberculosis del país, durante un período de cuatro meses del año 2008. Quinientos cuarenta y cinco (90,8 por ciento) correspondieron a localización pulmonar y 55 (9,2 por ciento) a extrapulmonar. Se confirmó la alcohol-ácido resistencia por tinción de Ziehl Neelsen y para la identificación de especies o complejos micobacterianos se utilizaron pruebas tradicionales y bioquímicas de acuerdo al criterio de clasificación de Runyon, sondas genéticas y análisis de patrones de restricción (PRA). Resultados: De los 600 cultivos recibidos, 585fueron aptos para ser incluidos en el estudio. De éstos, en el 91,3 por ciento (n = 534) de los casos se aisló Mycobacterium tuberculosis, en un 0,3 por ciento Mycobacterium bovis subespecie BCG (n = 3) y un 8,4 por ciento (n = 48) correspondió a micobacterias ambientales. De estas últimas, Mycobacterium kansasii (2,6 por ciento), Mycobacterium avium-intracellulare (1,5 por ciento) y Mycobacterium chelonae (1,0 por ciento) fueron las más comúnmente aisladas. Conclusiones: De acuerdo a las cifras obtenidas en este estudio y comparadas con estudios de años anteriores (1988 y 1998) se concluye que el número de aislamientos de micobacterias ambientales permaneció relativamente constante esta última década, como también las especies más comúnmente aisladas.