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.

Synchronization of Synovial Chondromatosis and Mycobacterium intracellurae Infection in Olecranon Bursitis: A Case Report

A 73-year-old woman presented with a recurrent cystic mass around her left olecranon. She had a history of 8 steroid injections due to elbow pain beginning 3 years ago and twice had undergone aspiration of olecranon bursitis that developed two months prior to presentation. She had been taking medications for hypertension and diabetes with no pertinent past history. On magnetic resonance imaging (MRI), there were multiple nodules in the olecranon bursa, which were isointense to muscle on T1-weighted images and hyperintense to muscle on T2-weighted images. Our initial diagnosis was synovial chondromatosis. On bursoscopy, masses of gray-white colored nodules were observed in the bursa. Finally, synovial chondromatosis and non-tuberculous mycobacterial infection were concurrently diagnosed. In conclusion, uncalcified synovial chondromatosis and rice bodies can have similar visual and MRI characteristics; therefore, we suggest that clinicians should be aware of the possibility of other infections in cases of this type.

Analysis of distribution characteristics of clinical isolates of nontuberculous mycobacteria in a general hospital / 中华传染病杂志

Objective To investigate the current prevalence of nontuberculous mycobacteria (NTM) in Shanghai,and to study the distribution characteristics of NTM clinical isolates,which may help to improve the diagnostic level of NTM and provide guidance for effective prevention and treatment of NTM infection.Methods Culture-positive isolates of clinical mycobacteria were collected from 2008 to 2013 in Huashan Hospital affiliated to Fudan University.All isolates were heat inactivated,and the genomic DNA was extracted and the species were identified by comprehensive comparative analysis of 16S rDNA,hsp65 and rpoB target genes sequencing.Results From January 2008 to December 2013,the overall mycobacterial culture-positive rate was 4.1 ％ (411/10 015).After excluding the repeated isolates,a total of 253 culture-positive mycobacteria isolates were collected for the species identification.By genes sequencing analysis,140 isolates were identified as mycobacterium tuberculosis complex (MTBc),102 NTM and 11 Nocardias,accounting for 55.3％,40.3％ and 4.4％,respectively.Positive rate of NTM isolates had an increasing trend from 25.0％ in 2008 to 42.7％ in 2013,reaching a highest rate of 54.9％ in 2012.In further analysis of 102 NTM isolates,16 species were identified.Among them,28 were M.abscesses,18 strains of M.marinum,17 strains of M.avium-intracellulare complex and 10 strains of M.fortuitum,accounted for 27.5％,17.6％,16.7％ and 9.8％,respectively.Conclusions Both of the isolation number and isolation rate of NTM in the general hospital are increasing.NTM related cases are also increasing in recent years,which mainly caused by M.abscess,M.marinum,M.aviumintracellulare complex and M.fortuitum.

Comparing the Genotype and Drug Susceptibilities between Mycobacterium avium and Mycobacterium intracellulare in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Mycobacterium avium (M. avium) and Mycobacterium intracellulare (M. intracellulare) are the major causative agents of nontuberculous mycobacteria (NTM)-related pulmonary infections. However, little is known about the differences in drug susceptibility profiles between these two species.</p><p><b>METHODS</b>A total of 393 NTM isolates were collected from Shanghai Pulmonary Disease Hospital. Sequencing of partial genes was performed to identify the strains at species level. The minimum inhibitory concentration (MIC) was used to evaluate the drug susceptibility against 20 antimicrobial agents. Variable number of tandem repeat (VNTR) typing was conducted to genotype these two species.</p><p><b>RESULTS</b>A total of 173 (44.0%) M. avium complex (MAC) isolates were identified, including 41 (10.4%) M. avium isolates and 132 (33.6%) M. intracellulare isolates. Clarithromycin and amikacin were the two most effective agents against MAC isolates. The Hunter-Gaston Discriminatory Index (HGDI) values for VNTR typing of M. avium and M. intracellulare isolates were 0.993 and 0.995, respectively. Levofloxacin resistance was more common among the unclustered strains than among the clustered strains of M. intracellulare.</p><p><b>CONCLUSION</b>M. intracellulare was the most common NTM species in China. Clarithromycin and amikacin had high antimicrobial activities against MAC. VNTR typing of MAC isolates revealed a high discriminatory power. Levofloxacin resistance was associated with unclustered strains of M. intracellulare.</p>

Non-Tuberculous Mycobacterium Induced Pseudoaneurysm of the Common Carotid Artery

An 81-year-old male patient presented with complaint of a pulsating neck mass. The patient had a previous history of cervical lymphadenopathy by non-tuberculous mycobacterium infection. Rapid growth of the mass on admission and contrast enhanced computed tomography of the neck resulted in a diagnosis of non-tuberculous mycobacterium induced pseudoaneurysm. The patient underwent emergency open repair of the pseudoaneurysm. Pseudoaneurysm of the common carotid artery is regularly reported, but here we report a rare case of non-tuberculous mycobacterium induced pseudoaneurysm of the common carotid artery.

Distribution of nontuberculous mycobacteria of clinical mycobacterium isolates f rom Fujian Province,China / 中国人兽共患病学报

ABSTRACT:To understand the species distribution of nontuberculous mycobacteria (NTM ) in Fujian Province of China , we collected clinical Mycobacterium isolates in the Fuzhou Pulmonary Hospital from 2009 to 2012 .A total of 6 362 clinical My‐cobacteria isolates were identified as 5 713 (89 .8% ) M .tuberculosis complex and 649 (10 .2% ) NTM strains by conventional identification method .Then ,by means of hsp65‐and rpoB‐PCR‐RFLP methods ,649 NTM strains were identified as 24 spe‐cies or complex of NTM ,in which the top three species or complex with the highest occurrence frequency were M .intracellular , M .avium and M .abscessus ,accounting for 48 .5% ,21 .3% and 12 .5% respectively .The prevalence rate of NTM was 10 .2%among Mycobacterium culture‐positive patients .There are lots of NTM species infecting human being ,and the most prevalence NTM species was M .avium complex accounting for 67 .8% in Fujian Province .

Isolation of Mycobacterium fortuitum in sputum specimens of a patient with chronic cough: Is it clinically significant?

Managing chronic cough is diagnostically challenging especially in primary care. This case report highlights the difficulties experienced in approaching a case of chronic cough from a primary care perspective. The discussion also involves the clinical significance and treatment dilemma of M. fortuitum chelonae complex that was isolated from the sputum cultures of an elderly woman who presented with chronic cough for more than a year.

Species and drug resistance of Mycobacterium isolated from sputum smear positive patients / 中国感染控制杂志

Objective To study the species and drug resistance of Mycobacterium isolated from patients with spu-tum smear positive for acid-fast bacillus in Wuj iang city,and provide reference for the prevention and control of tu-berculosis. Methods Sputum specimens with positive smear were cultured,isolated bacteria were identified and performed drug susceptibility testing,drug resistance among different species of strains and between patients with initial and repeated treatment were compared.Results A total of 1 03 Mycobacterium isolates were included in the study,13 of which were nontuberculous Mycobacterium,drug resistance rate was 100.00% ,multidrug resistance (MDR)rate was 84.62% ;90 isolates were Mycobacteriumtuberculosis,81(90.00% )of which were Mycobacteri-umhominis. Drug resistance rate of Mycobacteriumtuberculosiswas 35.56% ,MDR rate was 14.44% . Of 70 ini-tially treated tuberculosis patients with positive sputum smear,14(20.00% )were resistant to drugs,MDR rate was 4.28% (3/70);Of 20 repeatedly treated tuberculosis patients with positive sputum smear,18(90.00% )were resist-ant to drugs,MDR rate was 50.00% (10/20).Conclusion Mycobacteriumtuberculosisis the major isolated strain from patients with positive sputum smear. Drug resistance and MDR rates of nontuberculous Mycobacterium are very high. Drug resistance and MDR rates of Mycobacteriumtuberculosisin repeatedly treated patients are higher than initially treated patients.

Recent Trends in Clinically Significant Nontuberculous Mycobacteria Isolates at a Korean General Hospital

Lung disease caused by nontuberculous mycobacteria (NTM) represents an increasing proportion of all mycobacterial diseases. We investigated recent occurrences of NTM and evaluated the clinical significance of NTM isolates from 752 respiratory specimens collected from patients at National Health Insurance Service Ilsan Hospital between January 2007 and May 2011. Specimens were incubated on solid and liquid media (BACTEC MGIT 960, BD, USA) for 6-8 weeks, and PCR and reverse blot hybridization were performed (REBA Myco-ID, Molecules & Diagnostics, Korea). Clinical features of the patients were reviewed through medical records. The most frequently isolated organism was Mycobacterium avium (46.7%), followed by M. intracellulare (14.8%), M. fortuitum (7.2%), and M. abscessus (6.6%). The most common mycobacteria among definitive cases of NTM lung disease were M. avium (42/351, 12.0%), M. intracellulare (19/111, 17.1%), M. abscessus (11/50, 22.0%), M. massiliense (4/13, 30.8%), and M. fortuitum (4/54, 7.4%). Clinically significant cases of NTM lung disease increased from 4 patients in 2007 to 32 in 2011. The mean patient age was 64 yr (range: 35-88 yr), and 58 (64%) patients were women. Patients suffered from cough, productive sputum, and hemoptysis. In summary, the most common mycobacteria causing NTM lung disease were M. avium and M. intracellulare; however, cases of M. massiliense and M. abscessus infection are on the rise in Korea.

Infección pulmonar por mycobacterium avium complex en el huésped inmunocompetente / Mycobacterium avium complex pulmonary disease in immunocompetent adult patients

Las micobacterias no tuberculosas (MNT) se reconocen cada vez más como importantes patógenos pulmonares. El complejo Mycobacterium avium-intracellulare (MAC) causa la mayoría de las infecciones pulmonares por MNT. Aunque el organismo fue identificado en la década de 1890, su potencial patogenicidad en seres humanos fue reconocida sólo cincuenta años después. Los pacientes con enfermedad pulmonar preexistente o inmunodeficiencia están en mayor riesgo de desarrollar infección por MAC. Sin embargo, la mayoría de los casos se producen en mujeres de edad avanzada inmunocompetentes en asociación con infiltrados nodulares y bronquiectasias. Recientemente, la enfermedad pulmonar también se ha descrito en pacientes inmunocompetentes expuestos a equipos de hidroterapia o jacuzzis contaminados con MAC. En relación a dos pacientes adultos inmunocompetentes con enfermedad pulmonar por MAC examinamos el cuadro clínico, los criterios diagnósticos y el tratamiento de esta entidad.

Nontuberculous mycobacteria (NTM) are increasingly recognized as important pulmonary pathogens. Mycobacterium avium intracellulare complex (MAC) causes most lung infections due to NTM. Although the organism was identified in the 1890s, its potential to cause human disease was only recognized 50 years later. Patients with preexisting lung disease or immunodeficiency are at greatest risk for developing MAC infection. The majority of MAC pulmonary cases, however, occur in immunocompetent elderly women in association with nodular infiltrates and bronchiectasis. More recently, pulmonary disease has also been described in immunocompetent patients after exposure to MAC-contaminated hot tubs. We describe two cases of MAC lung disease in immunocompetent adult patients without preexisting lung disease and we review clinical manifestations, diagnostic criteria and treatment of this entity.

A Case Report of Mycobacterium abscessus Peritonitis in a Patient on Continuous Ambulatory Peritoneal Dialysis / 대한임상미생물학회지

Mycobacterium is an uncommon cause of peritonitis in patients receiving peritoneal dialysis (PD), and the incidence of nontuberculous mycobacterium (NTM) peritonitis is even rarer since the majority of mycobacterial peritonitis cases are caused by Mycobacterium tuberculosis. However, NTM peritonitis has been known to result in a high mortality rate with delayed diagnosis and treatment. In this study, we report a case of Mycobacterium abscessus peritonitis in a 52-year-old male under continuous ambulatory peritoneal dialysis (CAPD).

Nontuberculous Mycobacterial Infection after Breast Reconstruction with an Implant: A Case Report

PURPOSE: Breast implant surgery is increasing in Korea. NTM (non tuberculous mycobacteria) infection after breast implant surgery is rare, but it has been there reported in several foreign countries. However, no report has been issued on NTM infection after breast reconstruction surgery with an implant in Korea. The purpose of this article is to report a case of NTM infection after breast reconstruction surgery with an implant. METHODS: A female patient who underwent total mastectomy and immediate breast reconstruction with a latissimus dorsi myocutaneous flap and an implant exhibited signs of inflammation after the surgery. Fluid cultures taken at the time of wound exploration were initially negative, but NTM was isolated by culture 10 days later. RESULTS: The implant was removed. M. fortuitum was identified by acid-fast culture and NTM-PCR. The patient was treated with combined antibiotic therapy. CONCLUSION: Although it is difficult to diagnose NTM infection after breast surgery, it is important that surgeons include NTM infection in the differential diagnosis of a post mammoplasty infection after breast implant surgery.

A Case of Skin Infection Caused by Nontuberculous Mycobacterium after External Dacryocystorhinostomy

PURPOSE: To report a case of skin infection caused by nontuberculous mycobacterium after external dacryocystorhinostomy. CASE SUMMARY: A 53-year-old female patient presented to our clinic with a tear on the left eye, although a silicone tube was intubated. Two weeks after external dacryocystorhinostomy, swelling and redness were found on the operation wound. Therefore, the patient received oral antibiotics and steroid treatments but did not improve. The mass was irregularly shaped and became larger; thus, excisional biopsy was performed at 2 months after external dacryocystorhinostomy. A chronic granulomatous tissue was detected in the excisional biopsy, and antimycobacterial medications were started in consultation with an internist. A moderate colony was observed, and rod-shaped bacteria Mycobacterium abscessus was found in the culture 47 days after acid-fast culture was performed. The patient was diagnosed with a periocular infection caused by nontuberculous mycobacterium. Finally, the lesion improved. CONCLUSIONS: Although patients with granulomatous tissue receive numerous treatments, if the lesion is not improved, then additional excisional biopsy and culture examination to identify infection by nontuberculous mycobacterium are necessary.

Nontuberculous Mycobacterial Infection after Body Contouring Procedure, Case Report

PURPOSE: NTM(non tuberculous mycobacteria) is rare cause of surgical site infection after plastic surgery in immunocompetent patients. There are some reports about NTM infection after body contouring procedure from Latin America. But, there is no report in Korea. The purpose of this article is to report 2 patients with soft tissue infection caused by NTM after body contouring procedure. METHODS: Two young female patients exhibited signs of inflammation and abscess after body contouring procedure. One patient underwent liposuction. The other underwent HPL(hypotonic pharmacologic lipo-dissolution) injection. RESULTS: The result of tissue cultures were positive for NTM. All patients responded to the combined therapeutic approach. CONCLUSION: The goal of this article is to raise awareness among plastic surgeons who may encounter such patients in their practice. NTM should be included in the differential diagnosis of surgical site infection after body contouring surgery.

Osteomyelitis due to Nontuberculous Mycobacterium in Immunocompetent Children: Report of Two Cases / 대한정형외과학회잡지

Osteomyelitis caused by nontuberculous mycobacterium (NTM) is rare in immunocompetent children, and is often difficult to differentiate from a bone tumor, juvenile rheumatoid arthritis, soft-tissue inflammation and subacute osteomyelitis. We report NTM osteomyelitis in immunocompetent children that developed at the left distal femoral epiphysis in a 24-month-old boy and at both tali in a 7-year-old boy.

A Case of Cytomegalovirus Colitis with Nontuberculous Mycobacterium Infection in Immunocompetent Host

Cytomegalovirus(CMV) infections are common in immune compromised situations such as human immunodeficiency virus infection and organ transplantation. However CMV colitis had been rarely found in immunocompetent individuals. We experienced a case of an 83-year-old female patient, initially immune competent, who developed a massive lower gastrointestinal bleeding caused by CMV colitis. Previously, multiple antibiotics were used for nontuberculous Myco- bacterium and other bacterial infections after total knee arthroplasty. Colonoscopy revealed multiple ulcerations and mucosal congestion with hemorrhage. In spite of ganciclovir therapy, our patient did not recover.

A Case of Exit-Site Infection and Abscess by Mycobacterium Abscessus in a CAPD Patient / 영남의대학술지

Nontuberculous mycobacterial infections are a rare, but clinically important cause of infections in continuous ambulatory peritoneal dialysis (CAPD) patients. This is typically suspected when a patient does not respond to treatment with the usual antibiotics. We describe here a case of Mycobacterium abscessus exit site infection with abdominal wall abscess formation that was associated with CAPD, which required peritoneal catheter removal, surgical debridement of the abscess and long term antibiotic therapy.

Analysis of pathogen identification from non-mycobacterium pulmonary tuberculosis / 中国感染与化疗杂志

Objective To analyze the nontubercutous mycobaeterium (NTM) identification data of two groups of sputum sam- ples during the periods of 1986 to 1997 and 2000 to 2005 so as to figure out the identification of NTM.Methods A total of 222 strains of non-tuberculosis mycobacteria were included for strain identification and sensitivity test with traditional methods.Re- suits According to Runyon classification, during the period of 1986-1997 there were 15 strains (15.5%) in GroupⅠ, 4 (4.2%) in GroupⅡ, 23 (24.0%)in GroupⅢand 54 (56.3%) in GroupⅣ;during the period of 2000—2005 there were 30 strains (16.1%) in GroupⅠ, 11(5.9%) in GroupⅡ, 51 (27.4%) in GroupⅢand 94 (50.6%) in GroupⅣ.The number of NTM types increased by 133.3%.The absolute number of NTM isolates in the first five years of this century increased by 93.89% compared with the numbers in the 11 years of last century.Conclusions The number of types and absolute number of i- solates of NTM have increased in the first live years of this century compared with the numbers in the 11 years of last century. We should enhance the epidemiological research on pulmonary NTM in order to provide scientific evidence for comprehensive prevention and treatment.

Susceptibility Pattern and Epidemiology of Nontuberculous Mycobacteria in Shanghai / 中华医院感染学杂志

OBJECTIVE To examine the prevalence and trends of drug resistance of nontuberculous mycobacteria(NTM)in Shanghai.METHODS All NTM strains isolated between 1998 and 2004 in Shanghai were identified with conventional biochemical tests.Antimicrobial susceptibility test for all NTM was performed by standard absolute concentration method.RESULTS The prevalence rate was determined as 1.49%,1.17%,1.98%,2.46%,2.66%,2.72% and 3.0% among mycobacteria culture positive patients per year in 1998,1999,2000,2001,2002,2003,and in 2004,respectively.These data indicated the prevalence rate has continuously increased.Distribution of NTM isolates was Group Ⅰ18.7%,Group Ⅱ 5.1%,Group Ⅲ 25.1%,and Group Ⅳ 51.1% accordingly.Group Ⅳ rapidly growing NTM accounted for majority of them.Most of NTM showed high drug resistance to general antituberculotic drug.In particular Group Ⅳ Mycobacterium chelonae and M.fortuitum appeared multi-drug resistance.CONCLUSIONS The prevalence rate of NTM in Shanghai shows increased tendency.Most of NTM isolates are Group Ⅳ rapidly growing NTM.NTM shows high drug resistance to first line antituberculotic substance.

Clinical Utility of Polymerase Chain Reaction for the Differentiation of Nontuberculous Mycobacteria in Patients with Acid-fast Bacilli Smear-positive Specimens / 결핵및호흡기질환

BACKGROUND: In Korea, polymerase chain reaction (PCR) test for M. tuberculosis has been used for the diagnosis of acid-fast bacilli (AFB) smear-negative tuberculosis in order to increase diagnostic sensitivity. However, there have been no data dealing with the clinical utility of PCR in AFB smear-positive patients to differentiate between M. tuberculosis and nontuberculous mycobacteria. METHOD: We retrospectively analyzed the PCR test results which have been performed in patients who had AFB smear-positive sputum but had ambiguous clinical manifestations of active tuberculosis. PCR test was done using AMPLICORa M. tuberculosis kit. The sensitivity, specificity, and positive and negative predictive values of the PCR test were calculated based on culture and final clinical diagnosis result. RESULTS: Fifty-six consecutive patients (62 PCR tests) were included in the study. Active tuberculosis was diagnosed in 23 patients (41.0%), while 9 patients had NTM infection (16.0%). The sensitivity, specificity, positive- and negative-predictive value of PCR test were 88.8%, 86.8%, 76.1% and 94.3%, respectively, according to the culture result. In comparison, they were 91.3%, 100%, 100%, 94.3%, respectively, according to the final clinical diagnosis. All 15 patients with NTM isolates, including 6 patients who had other lung diseases but expectorated NTM isolate, were negative for PCR test. CONCLUSION: Even though tuberculosis is still prevalent in Korea, PCR test is useful to differentiate between M. tuberculosis and NTM in patients with AFB-smear positive sputum but with ambiguous clinical manifestations of active tuberculosis.