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A simple PCR method for rapid genotype analysis of Mycobacterium ulcerans

Stinear T, Davies JK, Jenkin GA, Portaels F, Ross BC, Oppedisano F, et al.

J Clin Microbiol, 2000 Apr;38(4):1482-7.
PMID: 10747130

Two high-copy-number insertion sequences, IS2404 and IS2606, were recently identified in Mycobacterium ulcerans and were shown by Southern hybridization to possess restriction fragment length polymorphism between strains from different geographic origins. We have designed a simple genotyping method that captures these differences by PCR amplification of the region between adjacent copies of IS2404 and IS2606. We have called this system 2426 PCR. The method is rapid, reproducible, sensitive, and specific for M. ulcerans, and it has confirmed previous studies suggesting a clonal population structure of M. ulcerans within a geographic region. M. ulcerans isolates from Australia, Papua New Guinea, Malaysia, Surinam, Mexico, Japan, China, and several countries in Africa were easily differentiated based on an array of 4 to 14 PCR products ranging in size from 200 to 900 bp. Numerical analysis of the banding patterns suggested a close evolutionary link between M. ulcerans isolates from Africa and southeast Asia. The application of 2426 PCR to total DNA, extracted directly from M. ulcerans-infected tissue specimens without culture, demonstrated the sensitivity and specificity of this method and confirmed for the first time that both animal and human isolates from areas of endemicity in southeast Australia have the same genotype.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology*
Fulltext Genome sequence of Mycobacterium abscessus strain M152

Ngeow YF, Wong YL, Tan JL, Ong CS, Ng KP, Choo SW

J Bacteriol, 2012 Dec;194(23):6662.
PMID: 23144407 DOI: 10.1128/JB.01846-12

Mycobacterium abscessus is an environmental bacterium with increasing clinical relevance. Here, we report the annotated whole-genome sequence of M. abscessus strain M152.

Matched MeSH terms: Mycobacterium Infections/microbiology
Fulltext Genomic analysis of Mycobacterium abscessus strain M139, which has an ambiguous subspecies taxonomic position

Ngeow YF, Wee WY, Wong YL, Tan JL, Ongi CS, Ng KP, et al.

J Bacteriol, 2012 Nov;194(21):6002-3.
PMID: 23045507 DOI: 10.1128/JB.01455-12

Mycobacterium abscessus is a ubiquitous, rapidly growing species of nontuberculous mycobacteria that colonizes organic surfaces and is frequently associated with opportunistic infections in humans. We report here the draft genome sequence of Mycobacterium abscessus strain M139, which shows genomic features reported to be characteristic of both Mycobacterium abscessus subsp. abscessus and Mycobacterium abscessus subsp. massiliense.

Matched MeSH terms: Mycobacterium Infections/microbiology
Fulltext Genome sequence of the Mycobacterium abscessus strain M93

Choo SW, Wong YL, Yusoff AM, Leong ML, Wong GJ, Ong CS, et al.

J Bacteriol, 2012 Jun;194(12):3278.
PMID: 22628507 DOI: 10.1128/JB.00492-12

Mycobacterium abscessus is a rapid-growing species of nontuberculous mycobacteria that is frequently associated with opportunistic infections in humans. We report herein the draft genome sequence of M. abscessus strain M93.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology
Bilateral nontuberculous mycobacterial middle ear infection: a rare case

Tang IP, Singh S, Rajagopalan R

Ear Nose Throat J, 2014 Sep;93(9):390-4.
PMID: 25255345

Nontuberculous Mycobacterium (NTM) middle ear infection is a rare cause of chronic bilateral intermittent otorrhea. We report a rare case of bilateral NTM middle ear infection in which a 55-year-old woman presented with intermittent otorrhea of 40 years' duration. The patient was treated medically with success. We conclude that NTM is a rare but probably under-recognized cause of chronic otitis media. A high index of suspicion is needed for the diagnosis to avoid prolonged morbidity. Treatment includes surgical clearance of infected tissue with appropriate antimycobacterial drugs, which are selected based on culture and sensitivity.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/diagnosis*; Mycobacterium Infections, Nontuberculous/drug therapy; Mycobacterium Infections, Nontuberculous/pathology; Mycobacterium Infections, Nontuberculous/surgery
Fulltext Genomic reconnaissance of clinical isolates of emerging human pathogen Mycobacterium abscessus reveals high evolutionary potential

Choo SW, Wee WY, Ngeow YF, Mitchell W, Tan JL, Wong GJ, et al.

Sci Rep, 2014;4:4061.
PMID: 24515248 DOI: 10.1038/srep04061

Mycobacterium abscessus (Ma) is an emerging human pathogen that causes both soft tissue infections and systemic disease. We present the first comparative whole-genome study of Ma strains isolated from patients of wide geographical origin. We found a high proportion of accessory strain-specific genes indicating an open, non-conservative pan-genome structure, and clear evidence of rapid phage-mediated evolution. Although we found fewer virulence factors in Ma compared to M. tuberculosis, our data indicated that Ma evolves rapidly and therefore should be monitored closely for the acquisition of more pathogenic traits. This comparative study provides a better understanding of Ma and forms the basis for future functional work on this important pathogen.

Matched MeSH terms: Mycobacterium Infections/microbiology*; Mycobacterium Infections/pathology
Fulltext Phylogenomics of Brazilian epidemic isolates of Mycobacterium abscessus subsp. bolletii reveals relationships of global outbreak strains

Davidson RM, Hasan NA, de Moura VC, Duarte RS, Jackson M, Strong M

Infect Genet Evol, 2013 Dec;20:292-7.
PMID: 24055961 DOI: 10.1016/j.meegid.2013.09.012

Rapidly growing, non-tuberculous mycobacteria (NTM) in the Mycobacterium abscessus (MAB) species are emerging pathogens that cause various diseases including skin and respiratory infections. The species has undergone recent taxonomic nomenclature refinement, and is currently recognized as two subspecies, M. abscessus subsp. abscessus (MAB-A) and M. abscessus subsp. bolletii (MAB-B). The recently reported outbreaks of MAB-B in surgical patients in Brazil from 2004 to 2009 and in cystic fibrosis patients in the United Kingdom (UK) in 2006 to 2012 underscore the need to investigate the genetic diversity of clinical MAB strains. To this end, we sequenced the genomes of two Brazilian MAB-B epidemic isolates (CRM-0019 and CRM-0020) derived from an outbreak of skin infections in Rio de Janeiro, two unrelated MAB strains from patients with pulmonary infections in the United States (US) (NJH8 and NJH11) and one type MAB-B strain (CCUG 48898) and compared them to 25 publically available genomes of globally diverse MAB strains. Genome-wide analyses of 27,598 core genome single nucleotide polymorphisms (SNPs) revealed that the two Brazilian derived CRM strains are nearly indistinguishable from one another and are more closely related to UK outbreak isolates infecting CF patients than to strains from the US, Malaysia or France. Comparative genomic analyses of six closely related outbreak strains revealed geographic-specific large-scale insertion/deletion variation that corresponds to bacteriophage insertions and recombination hotspots. Our study integrates new genome sequence data with existing genomic information to explore the global diversity of infectious M. abscessus isolates and to compare clinically relevant outbreak strains from different continents.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology*; Mycobacterium Infections, Nontuberculous/epidemiology*
High resolution melting analysis for the differentiation of Mycobacterium species

Issa R, Abdul H, Hashim SH, Seradja VH, Shaili N', Hassan NAM

J Med Microbiol, 2014 Oct;63(Pt 10):1284-1287.
PMID: 25038139 DOI: 10.1099/jmm.0.072611-0

A quantitative real-time PCR (qPCR) followed by high resolution melting (HRM) analysis was developed for the differentiation of Mycobacterium species. Rapid differentiation of Mycobacterium species is necessary for the effective diagnosis and management of tuberculosis. In this study, the 16S rRNA gene was tested as the target since this has been identified as a suitable target for the identification of mycobacteria species. During the temperature gradient and primer optimization process, the melting peak (Tm) analysis was determined at a concentration of 50 ng DNA template and 0.3, 0.4 and 0.5 µM primer. The qPCR assay for the detection of other mycobacterial species was done at the Tm and primer concentration of 62 °C and 0.4 µM, respectively. The HRM analysis generated cluster patterns that were specific and sensitive to distinguished small sequence differences of the Mycobacterium species. This study suggests that the 16S rRNA-based real-time PCR followed by HRM analysis produced unique cluster patterns for species of Mycobacterium and could differentiate the closely related mycobacteria species.

Matched MeSH terms: Mycobacterium Infections/diagnosis*; Mycobacterium Infections/microbiology
Fulltext Antibiotic resistance in Mycobacterium Abscessus and Mycobacterium Fortuitum isolates from Malaysian patients

Jayasingam SD, Zin T, Ngeow YF

Int J Mycobacteriol, 2017 11 25;6(4):387-390.
PMID: 29171453 DOI: 10.4103/ijmy.ijmy_152_17

BACKGROUND: Rapidly growing mycobacterial species (RGM) are increasingly being recognized as the cause of various superficial and deep infections in humans. Two of the species most frequently isolated from clinical specimens are Mycobacterium abscessus and Mycobacterium fortuitum. Both species are associated with antibiotic resistances that may complicate therapy. This paper describes the pattern of resistance to five antibiotics commonly prescribed for RGM infections, in M. abscessus and M. fortuitum isolated from Malaysian patients.
METHODS: The bacterial strains studied were examined with Etest strips to determine their minimum inhibitory concentrations (MICs) toward amikacin, ciprofloxacin, clarithromycin, imipenem, and linezolid.
RESULTS: Among 51 M. abscessus isolates examined by the Etest, the overall MICs of ciprofloxacin, imipenem, amikacin, clarithromycin, and linezolid showed resistance rates of 33.3%, 31.4%, 2.0%, 5.9%, and 21.6%, to the five antibiotics, respectively. M. abscessus subspecies abscessus was more resistant than M. abscessus subsp. massilience to ciprofloxacin, imipenem, and linezolid but was more susceptible to clarithromycin and amikacin. M. fortuitum isolates were significantly less resistant than M. abscessus to ciprofloxacin (3.6%) and imipenem (7.1%) but more resistant to clarithromycin (42.9%) and linezolid (39.3%).
CONCLUSION: A suitable combination therapy for Malaysian patients would be amikacin plus clarithromycin and ciprofloxacin, to cover infections by all three M. abscessus subspecies and M. fortuitum.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/drug therapy*; Mycobacterium Infections, Nontuberculous/microbiology
Fulltext Cystic teratoma mimicking recurrent pleural effusion, complicated by Mycobacterium abscessus infection

Mohd Esa NY, Mohd Radzi AA, Bakar NS, Mohd Khalid MS, Ismail AI, Abdul Rani MF

Respirol Case Rep, 2016 May;4(3):e00155.
PMID: 27516884 DOI: 10.1002/rcr2.155

Teratomas of anterior mediastinum are rare. They are often slow growing, asymptomatic, and detected incidentally on chest imaging. Mycobacterium abscessus (M. abscessus) is an acid-fast bacillus that is classified as a pathogenic "rapid growing" non-tuberculous mycobacteria. It is an uncommon cause of human pathology, which may cause skin and soft tissue infection after skin injury following inoculation, minor trauma, and surgery. Here, we present an unusual case of benign cystic teratoma mimicking recurrent pleural effusion, which was subsequently complicated by M. abscessus infection following thoracotomy. Cystic teratoma is rare, but it needs to be considered whenever clinical and investigative work-up fails to provide a convincing diagnosis. A combined clinical, radiological, surgical, and histopathological assessment is important to arrive at the correct diagnosis. Rapidly growing mycobacteria needs to be included in the differential diagnosis of patients with non-resolving infected post-thoracotomy wound and who do not respond to broad-spectrum antibiotics.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous
Heterogeneity of mycolactones produced by clinical isolates of Mycobacterium ulcerans: implications for virulence

Mve-Obiang A, Lee RE, Portaels F, Small PL

Infect Immun, 2003 Feb;71(2):774-83.
PMID: 12540557

Mycobacterium ulcerans is the causative agent of Buruli ulcer, a severe necrotizing skin disease endemic in tropical countries. Clinical evidence suggests that M. ulcerans isolates from Asia, Mexico, and Australia may be less virulent than isolates from Africa. In vivo studies suggest that mycolactone, a polyketide-derived macrolide toxin, plays a major role in the tissue destruction and immune suppression which occur in cases of Buruli ulcer. Mycolactones were extracted from 34 isolates of M. ulcerans representing strains from Africa, Malaysia, Asia, Australia, and Mexico. Thin-layer chromatography, mass spectroscopic analysis, and cytopathic assays of partially purified mycolactones from these isolates revealed that M. ulcerans produces a heterogeneous mixture of mycolactone variants. Mycolactone A/B, the most biologically active mycolactone species, was identified by mass spectroscopy as [M(+)Na](+) at m/z 765.5 in all cytotoxic isolates except for those from Mexico. Mycolactone C [M+Na](+) at m/z 726.3 was the dominant mycolactone species in eight Australian isolates, and mycolactone D [M+Na](+) m/z 781.2 was characteristic of two Asian strains. Mycolactone species are conserved within specific geographic areas, suggesting that there may be a correlation between mycolactone profile and virulence. In addition, the core lactone, [M+Na](+) m/z 447.4, was identified as a minor species, supporting the hypothesis that mycolactones are synthesized by two polyketide synthases. A cytopathic assay of the core lactone showed that this molecule is sufficient for cytotoxicity, although it is much less potent than the complete mycolactone.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology*
Fulltext Draft genome sequence of Mycobacterium bolletii strain M24, a rapidly growing mycobacterium of contentious taxonomic status

Wong YL, Choo SW, Tan JL, Ong CS, Ng KP, Ngeow YF

J Bacteriol, 2012 Aug;194(16):4475.
PMID: 22843600 DOI: 10.1128/JB.00916-12

The whole-genome sequence of Mycobacterium bolletii M24, isolated from the bronchoalveolar lavage fluid of a Malaysian patient, is reported here. The circular chromosome of 5,507,730 bp helped to clarify the taxonomic position of this organism within the M. abscessus complex and revealed the presence of proteins potentially important for pathogenicity in a human host.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology
Analysis of the genome of Mycobacterium abscessus strain M94 reveals an uncommon cluster of tRNAs

Choo SW, Wong YL, Leong ML, Heydari H, Ong CS, Ng KP, et al.

J Bacteriol, 2012 Oct;194(20):5724.
PMID: 23012295

Mycobacterium abscessus is a species of rapidly growing nontuberculous mycobacteria that is frequently associated with opportunistic infections in humans. Here, we report the annotated genome sequence of M. abscessus strain M94, which showed an unusual cluster of tRNAs.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology
Fulltext Genome analysis of Mycobacterium massiliense strain M172, which contains a putative mycobacteriophage

Choo SW, Yusoff AM, Wong YL, Wee WY, Ong CS, Ng KP, et al.

J Bacteriol, 2012 Sep;194(18):5128.
PMID: 22933758 DOI: 10.1128/JB.01096-12

The genome of Mycobacterium massiliense M172, isolated from a human sputum sample, was sequenced using Illumina GA IIX technology and found to contain 5,204,460 bp, including putative genes for virulence and antibiotic resistance as well as a 92-kb genomic region most likely to correspond to a mycobacteriophage.

Matched MeSH terms: Mycobacterium Infections/microbiology
Fulltext Annotated genome sequence of Mycobacterium massiliense strain M154, belonging to the recently created taxon Mycobacterium abscessus subsp. bolletii comb. nov

Choo SW, Wong YL, Tan JL, Ong CS, Wong GJ, Ng KP, et al.

J Bacteriol, 2012 Sep;194(17):4778.
PMID: 22887675 DOI: 10.1128/JB.01043-12

Mycobacterium massiliense has recently been proposed as a member of Mycobacterium abscessus subsp. bolletii comb. nov. Strain M154, a clinical isolate from the bronchoalveolar lavage fluid of a Malaysian patient presenting with lower respiratory tract infection, was subjected to shotgun DNA sequencing with the Illumina sequencing technology to obtain whole-genome sequence data for comparison with other genetically related strains within the M. abscessus species complex.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/microbiology
Fulltext Differences in virulence and immune response induced in a murine model by isolates of Mycobacterium ulcerans from different geographic areas

Ortiz RH, Leon DA, Estevez HO, Martin A, Herrera JL, Romo LF, et al.

Clin Exp Immunol, 2009 Aug;157(2):271-81.
PMID: 19604267 DOI: 10.1111/j.1365-2249.2009.03941.x

Buruli ulcer (BU) is the third most common mycobacterial disease in immunocompetent hosts. BU is caused by Mycobacterium ulcerans, which produces skin ulcers and necrosis at the site of infection. The principal virulence factor of M. ulcerans is a polyketide-derived macrolide named mycolactone, which has cytotoxic and immunosuppressive activities. We determined the severity of inflammation, histopathology and bacillary loads in the subcutaneous footpad tissue of BALB/c mice infected with 11 different M. ulcerans isolates from diverse geographical areas. Strains from Africa (Benin, Ghana, Ivory Coast) induced the highest inflammation, necrosis and bacillary loads, whereas the strains collected from Australia, Asia (Japan, Malaysia, New Guinea), Europe (France) and America (Mexico) induced mild inflammation. Subsequently, animals were infected with the strain that exhibited the highest (Benin) or lowest (Mexico) level of virulence in order to analyse the local immune response generated. The Mexican strain, which does not produce mycolactone, induced a predominantly T helper type 1 (Th1) cytokine profile with constant high expression of the anti-microbial peptides beta defensins 3 and 4, in co-existence with low expression of the anti-inflammatory cytokines interleukin (IL)-10, IL-4 and transforming growth factor (TGF)-beta. The highly virulent strain from Benin which produces mycolactone A/B induced the opposite pattern. Thus, different local immune responses were found depending on the infecting M. ulcerans strain.

Matched MeSH terms: Mycobacterium Infections, Nontuberculous/immunology

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