Prevalence of Non-Tuberculous Mycobacteria in Hospital Waters of Major Cities of Khuzestan Province, Iran

Molecular identification of nontuberculous mycobacteria using the rpoB, argH and cya genes analysis

Nontuberculous mycobacterial (NTM) infections are growing worldwide especially in immunocompromised individuals. Since treatment of NTM infections is species-specific, the precise identification of NTM to species level is critical for an optimal treatment. This study was aimed to identify different NTM species by sequencing the rpoB gene and evaluating the effectiveness of argH and cya gene markers. In total 64 clinical isolates suspected to NTM were collected. The identification of the isolates was done by standard conventional methods and PCR-based rpoB gene and sequence analysis. PCR sequencing of argH and cya genes was performed to evaluate the efficacy of these genes in identifying and differentiating different species and subspecies of NTM. Among 64 isolates tested, 51 (79.68%) were detected by conventional tests as NTM. The results of rpoB sequence analysis revealed that the 56 clinical isolates were identified in 10 species of NTM and 8 remaining isolates which showed ambiguous results by rpoB sequencing, application of argH and cya sequencing could detect these isolates. Furthermore, by using cya gene sequencing, M. abscessus subspecies were properly differentiated. Although the rpoB sequencing as a standard method, is beneficial for detecting various species of NTM, however, based on our findings, argH and cya gene markers have a superb ability to discriminate closely related species. Further investigations are required to verify our outcomes.

Nontuberculous Mycobacteria in Humans, Animals, and Water in Zambia: A Systematic Review

Nontuberculous mycobacteria (NTM) are environmental opportunistic pathogens of humans and animals that are emerging with a serious public health impact particularly in individuals with Acquired Immunodeficiency Syndromes. Recent scientific evidence is shifting from NTMs being known as traditional environmental organisms to serious pathogenic organisms in both animals and humans. In humans, factors attributable to this rise have been linked mainly to Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome pandemic. In recent years there has been an increase in multidrug resistant Tuberculosis in Zambia and it is thought that NTMs could possibly be the cause. This study was therefore formulated to review available information on the prevalence of NTM in humans, animals and the environment, species distribution, zoonotic potential and public health importance in Zambia. This review was conducted in accordance with PRISMA guidelines. A literature search was done in PubMed and Google scholar using predefined search terms such as ‘nontuberculous mycobacteria’, ‘atypical mycobacteria’, ‘mycobacteria other than mycobacterium tuberculosis’ and ‘Zambia’, in combination with Boolean operators (AND, OR). This particular systematic review draws findings based on literature search between 2000 and 2020. Through literature search 243 papers were identified, 23 duplicates were identified and removed and 206 articles were excluded as they did not meet the inclusion criteria. The full text of the remaining 14 articles were considered for this review. The overall prevalence of NTM in humans was 24.39%, in water 21.5%, in animals 16.05% of which the prevalence in cattle was 14.81% and Kafue Lechwe 1.23%. Mycobacterium intracellulare was the most common isolated nontuberculous mycobacteria in humans and cattle while Mycobacterium gordonae was the most common in water, and Mycobacterium stomatepiae sp Nov in Kafue Lechwe. Nontuberculous mycobacteria are an emerging public health threat in Zambia both in humans and animals and this calls for the need for molecular information on the zoonotic transmission of nontuberculous mycobacteria. Increased awareness of nontuberculous mycobacteria diseases among clinicians and laboratory personnel is crucial for patient management and an essential step for facilitating the identification of nontuberculous mycobacteria species in laboratories.

ISOLATION AND ANTIMICROBIAL SUSCEPTIBILITIES OF NONTUBERCULOUS MYCOBACTERIA FROM WILDLIFE IN JAPAN

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

An update on prevalence of slow-growing mycobacteria and rapid-growing mycobacteria retrieved from hospital water sources in Iran - a systematic review

Introduction

This study aimed to assess the prevalence of slow growing mycobacteria (SGM) and rapid-growing mycobacteria (RGM) retrieved from hospital water sources in Iran from 2016 to 2020.

Methods

The review was conducted to get eligible published studies from 1^st January 2016 to 25^th March 2020 based on PRISMA protocol. A combination of related words from the Medical Subject Heading Terms (MeSH), with (AND, OR) were used to search for published studies reporting the prevalence of nontuberculous mycobacteria (NTM) in Scopus, MEDLINE, Web of Sciences, Google Scholar, and Iranian databases. Then data from the studies were extracted and reported.

Results

Our study showed that different water sources of hospitals were contaminated with NTMs. The prevalence of RGM isolates in hospital water samples varied between 42.2%-67.5%, and the prevalence of SGM varied between 32.5%-57.7%, respectively. M. lentiflavum (84.7%), M. avium complex(2.8%-56.4%)and M. gordonae (2.8%-56.2%) were the most prevalent NTM species amongst SGM, whereas M. fortuitum (2.9%-44.2%), M. chelonae (8%-36.8%), M. mucogenicum (8%-25.6%) were the most leading NTM isolates among RGM.

Conclusions

A high prevalence of NTM was reported from hospital environments particularly hospital water sources which can colonize medical devices, solutions, and water used for patients and cause nosocomial infection. Therefore, the hospitals should check the microbiological quality of the water used.

Drug susceptibility testing of Mycobacterium simiae: An emerging pathogen in Iran

INTRODUCTION

Mycobacterium simiaeis an emerging pathogen in Iran and little is known about drug susceptibility patterns of this pathogen.

MATERIALS AND METHODS

Twenty-five clinical isolates of M. simiaefrom 80 patients with confirmed NTM pulmonary disease were included in this study. For drug susceptibility testing (DST), proportional and broth microdilution methods were used according to the clinical and laboratory standards institute (CLSI) guideline.

RESULTS

All clinical isolates of M. simiaewere resistant to isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, ciprofloxacin, and clarithromycin. They also were highly resistant to ofloxacin (80%). Susceptibility to ofloxacin was only noted in the 5 isolates.

CONCLUSIONS

Clinical isolates of M. simiae were multidrug-resistant, and had different drug susceptibility patterns than previously published studies. DST results can assist in selecting more appropriate treatment regimens. Newer drugs with proven clinical efficacy correlating with in vitrosusceptibility should be substituted with first-and second-line anti-TB drug testing.

Molecular Identification, and Characterization of Mycobacterium kansasii Strains Isolated from Four Tuberculosis Regional Reference Laboratories in Iran During 2016-2018

Background

Non-tuberculous mycobacterial (NTM) infections are growing concern in many countries around the globe including Iran. Among them, Mycobacterium kansasii (M. kansasii) causes both pulmonary and extra-pulmonary infections. Despite the high prevalence of M. kansasii isolates in Iran, unfortunately little is known about the epidemiological aspects of M. kansasii infection. Hence, the aim of the present study was to investigate the molecular identification, determination of subtypes variation and geographic distribution of clinical isolates of M. kansasii isolates.

Methods

In the present study, 108 clinical pulmonary isolates suspected to NTM were collected from four Tuberculosis Regional Reference Laboratories in Iran during 2016–2018. The isolates were confirmed as NTM using conventional and molecular methods. Among them, M. kansasii isolates were subjected to rpoB gene sequencing. For determination of subtyping of M. kansasii isolates, polymerase chain reaction-restriction enzyme analysis (PCR-REA) based on the hsp65 gene was performed.

Results

Based on the rpoB gene sequence analysis, 33 (30.5%) isolates were identified as M. kansasii species, compared to 31 (28.7%) isolates using phenotypic methods. The subtype I was the most frequent subtype (n=24; 72.7%), followed by subtype II (n=8; 24.2%).

Conclusion

We indicated that the rate of M. kansasii isolation with clinical significance appears to be increasing in Iran, especially in highly industrialized cities. The high rate of M. kansasii subtype I may suggest that this genotype has a particular potency for colonization, and a higher epidemiological potential for causing infection in humans. More studies are needed to provide a better understanding of the biology and pathogenicity of M. kansasii subtype I.

Characteristics of clinical extrapulmonary nontuberculous mycobacteria isolates in Minnesota, 2013-2017

Approximately 80 species of nontuberculous mycobacteria (NTM) that cause disease are found environmentally and in animal reservoirs. Typically, pulmonary NTM infections are sporadic; extrapulmonary NTM (ENTM) infections are commonly outbreak associated. Recent sources of ENTM outbreaks in Minnesota include contaminated heater-cooler units used during cardiac surgery and contaminated hormone injections. We examined patient demographics and characteristics of ENTM isolates characterized by four Minnesota reference laboratories during 2013-2017 to assess potential value of systematic laboratory-based ENTM surveillance in Minnesota. Laboratories characterized 490 ENTM isolates, representing an estimated burden of 1.8/100,000 people/year in Minnesota. Thirty-one species or complexes were identified; most common were M. avium complex (31%), M. chelonae (22%), M. fortuitum (11%), and M. abscessus (4%). Most common specimen collection sites included skin and soft tissue (38%), blood (15%), neck lymph node or tissue (12%), sinus (8%), joint or bone (5%), device or implant (4%), and eye (3%). Median age of patients was 55 years (range: 2-98 years); 18% were from patients aged <18 years, 20% aged 18-44 years, 28% aged 45-64 years and 34% aged >65 years. Sex was documented for 238 (49%) patients; 127 (53%) were males. County information was available for 313 patients (64%); approximately half (49%) resided in metropolitan Minneapolis-Saint Paul. Laboratory data can be used for ENTM surveillance in Minnesota. Implementing laboratory-based surveillance can detect ENTM cases, provide a mechanism for obtaining clinical and epidemiological information, and enable earlier identification of potential health care transmission or community clusters.

[Species diversity of non-tuberculous mycobacteria isolated from aquatic environments of General Pico city, Province of La Pampa (Argentina)]

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 1.5mg/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.

Outbreaks of nontuberculous mycobacteria

PURPOSE OF REVIEW

The purpose of this review is to summarize the emerging literature on nontuberculous mycobacteria outbreaks in healthcare settings. As our ability to identify mycobacterial species develops, we are better able to recognize epidemiologic connections and better understand the prevalence and importance of these outbreaks and pseudo-outbreaks in healthcare settings.

RECENT FINDINGS

The number of outbreaks related to nontuberculous outbreaks is increasing because of heightened awareness and better diagnostic tests for species level identification of mycobacteria. Outbreaks in healthcare settings have been related to cardiac surgery, plastic surgery, including medical tourism, colonized humidifiers and heater-cooler devices, imperfect disinfection, and hospital water sources. Mycobacteria have a predilection to form biofilms, are resistant to disinfection and are prevalent in hospital water systems. Patients with structural lung disease like cystic fibrosis patients are at particularly high risk for mycobacterial infection. It has been thought that acquisition in this patient population is from common environmental exposure; however, there is increasing evidence that transmission in this patient population can occur through either direct or indirect patient-to-patient spread.

SUMMARY

Mycobacteria outbreaks in healthcare settings have been underrecognized. As we identify additional clusters of infection with better diagnostic tools and heightened awareness, we will likely need better infection control practices to prevent infections in healthcare settings.

Identification of nontuberculous mycobacteria isolated from hospital water by sequence analysis of the hsp65 and 16S rRNA genes

Nontuberculous mycobacteria (NTM) have emerged as an important cause of opportunistic nosocomial infections. NTM has frequently been isolated from hospital water distribution systems. The aim of this study was to survey the risk of NTM infections and determine the prevalence of NTM species in the hospital water distribution systems in Tabriz, Iran. One hundred and twenty samples of water from different sources of Tabriz hospitals were collected. The samples were filtered through 0.45-µm pore size membranes and decontaminated with 0.01% cetylpyridinium chloride. The sediment was inoculated onto Lowenstein-Jensen medium and incubated for 8 weeks. For identification to the species level, partial sequence analysis of the hsp65 and 16S rRNA genes were used. NTM were detected in 76 (63.3%) of 120 samples. Potentially pathogenic mycobacteria and saprophytic mycobacteria were isolated. Mycobacterium gordonae was the only single species that was present in all types of water. The prevalence of NTM in Tabriz hospitals' water compared with many investigations on hospital waters was high. This indicates that the immunocompromised patients and transplant recipients are at risk of contamination which necessitates considering decontamination of water sources to prevent such potential hazards.

Molecular identification and distribution of non-tuberculous mycobacteria isolated from clinical specimens by PCR-sequencing method in West of Iran

BACKGROUND AND AIMS

Infections by non-tuberculous mycobacteria (NTM) has rapidly increased in recent years, due to high infection rates related to the populations at risk like immunocompromised individuals, patients predisposed by prior pulmonary. The aim of this study was to investigate the presence of NTM in clinical samples and genetic diversity using 16S rRNA and rpoB sequence analysis.

METHODS

A cross-sectional study was conducted on 45 diverse isolates collected from sputum in 2 years 2014-2015 using standard decontamination procedure. All mycobacterial isolates were grown on LJ medium and also conventional tests for preliminary identification of mycobacteria rely on traits and then DNA extraction. PCR was performed, and sequencing of 16S rRNA and rpoB genes was applied for NTM strains identification.

RESULTS

A total of 45 isolates collected, 37 samples (83%) were evaluated as NTM. All NTM strains using molecular methods by sequencing 16S rRNA and rpoB gene were identified, by this way 12 different species have been identified which sequencing of rpoB was able to identify all species. The major species obtained were Mycobacterium simiae (22%), M. fortuitum (19%), and M. abscessus (13%).

CONCLUSIONS

The results of our study showed that the patients were infected by a wide range of atypical mycobacteria. It was concluded that 16S rRNA gene sequencing coupled with rpoB marker is a high discriminatory power in identification of NTM. The presence of various species in clinical samples in Iran emphasizes the use of molecular method like sequence analysis of genes is necessary for reliable identification.