Genetic Diversity of
            <i>Mycobacterium avium</i>
            Isolates Recovered from Clinical Samples and from the Environment: Molecular Characterization for Diagnostic Purposes

Álvarez, Julio; García, I. Gómez; Aranaz, Alicia; Bezos, Javier; Romero, Beatriz; Juan, Lucía de; Mateos, Ana; Gómez-Mampaso, E; Domı́nguez, Lucas

doi:10.1128/jcm.01621-07

Cited by 30 publications

(27 citation statements)

References 40 publications

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“…Insertion elements found in MAC subspecies provide useful markers for their identification through genotyping (2,4,21,39). Moreover, the markers appear to be associated with the subspecies' epidemiologies and pathogenicities, making the use of these markers clinically relevant.…”

Section: Discussionmentioning

confidence: 99%

“…IS901 is strongly associated with MAC infections in avian species, and IS901-positive strains are thus often called bird-type MAC members (7,8,39). IS1311 is consistently associated with the MAC, with only rare exceptions reported (2,21). Inclusion of primers for the 16S rRNA gene target common to all mycobacteria in the MAC multiplex serves as an internal control for confirmation of mycobacterial identification (34).…”

Section: Discussionmentioning

confidence: 99%

“…The majority of human M. avium subsp. hominissuis infections occur in HIV-immunocompromised people, immunocompetent persons with underling pulmonary disease, and children with cystic fibrosis (2,12,17). Considered ubiquitous in the environment (the most likely source of infection for humans), M. avium subsp.…”

mentioning

confidence: 99%

“…Contemporary methods for MAC identification, e.g., highperformance liquid chromatography (HPLC) of cell wall mycolic acids, and genetic probes based on rRNA targets, e.g., AccuProbe, cannot discriminate among M. avium subspecies (2,9). Given the differences in pathogenicity among M. avium subspecies and the implications regarding the infection source, a practical and accurate method of simply identifying M. avium subspecies is needed (13,25,35).…”

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confidence: 99%

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Efficient Differentiation ofMycobacterium aviumComplex Species and Subspecies by Use of Five-Target Multiplex PCR

et al. 2010

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Infections caused by the Mycobacterium avium complex (MAC) are on the rise in both human and veterinary medicine. A means of effectively discriminating among closely related yet pathogenetically diverse members of the MAC would enable better diagnosis and treatment as well as further our understanding of the epidemiology of these pathogens. In this study, a five-target multiplex PCR designed to discriminate MAC organisms isolated from liquid culture media was developed. This MAC multiplex was designed to amplify a 16S rRNA gene target common to all Mycobacterium species, a chromosomal target called DT1 that is unique to M. avium subsp. avium serotypes 2 and 3, to M. avium subsp. silvaticum, and to M. intracellulare, and three insertion sequences, IS900, IS901, and IS1311. The pattern of amplification results allowed determination of whether isolates were mycobacteria, whether they were members of the MAC, and whether they belonged to one of three major MAC subspecies, M. avium subsp. paratuberculosis, M. avium subsp. avium, and M. avium subsp. hominissuis. Analytical sensitivity was 10 fg of M. avium subsp. paratuberculosis genomic DNA, 5 to 10 fg of M. avium subsp. avium genomic DNA, and 2 to 5 fg of DNA from other mycobacterial species. Identification accuracy of the MAC multiplex was evaluated by testing 53 bacterial reference strains consisting of 28 different mycobacterial species and 12 nonmycobacterial species. Identification accuracy in a clinical setting was evaluated for 223 clinical MAC isolates independently identified by other methods. Isolate identification agreement between the MAC multiplex and these comparison assays was 100%. The novel MAC multiplex is a rapid, reliable, and simple assay for discrimination of MAC species and subspecies in liquid culture media.Since the early 1980s, there has been an increase in disease caused by organisms broadly categorized as nontuberculous mycobacteria (NTM), a generic term for mycobacteria not in the Mycobacterium tuberculosis complex and other than M. leprae (32). Of these NTM, Mycobacterium avium complex (MAC) species are the most common cause of human and animal disease globally (6,14,16,24). The clinical relevance of the MAC in humans has been amplified in recent decades with the increasing population of immunocompromised individuals resulting from longer life expectancy, immunosuppressive chemotherapy, and the AIDS pandemic (27 Members of the family Mycobacteriaceae, comprising the MAC, differ in virulence and ecology. Those designated M. avium subsp. hominissuis are genomically diverse, low-virulence, opportunistic pathogens for both animals and humans.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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confidence: 99%

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Efficient Differentiation ofMycobacterium aviumComplex Species and Subspecies by Use of Five-Target Multiplex PCR

et al. 2010

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“…hominissuis, has been isolated from patients with HIV, respiratory disease, and lymphadentitis (3,(18)(19)(20) as well as from asymptomatic swine with granulomatous lesions of the head and mesenteric lymph nodes (21). These findings indicate that both hosts are largely susceptible to this particular organism.…”

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confidence: 88%

Subspecies Identification and Significance of 257 Clinical Strains of Mycobacterium avium

Tran

Han

2014

J Clin Microbiol

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Mycobacterium avium is abundant in the environment. It has four subspecies of three types: the human or porcine type, M. avium subsp. hominissuis; the bird type, including M. avium subsp. avium serotype 1 and serotype 2, 3 (also M. avium subsp. silvaticum); and the ruminant type, M. avium subsp. paratuberculosis. We determined the subspecies of 257 M. avium strains isolated from patients at the M.D. Anderson Cancer Center from 2001 to 2010 and assessed their clinical significance. An assay of multiplex PCR was used for the typing. Results showed M. avium subsp. hominissuis to be most common (n ‫؍‬ 238, 92.6%), followed by M. avium subsp. avium serotype 1 (n ‫؍‬ 12, 4.7%) and serotype 2, 3 (n ‫؍‬ 7, 2.7%). No strains of M. avium subsp. paratuberculosis were found. Of the 238 patients with M. avium subsp. hominissuis, 65 (27.3%) showed evidence of definite or probable infections, mostly in the respiratory tract, whereas the rest had weak evidence of infection. The bird-type subspecies, despite being infrequently isolated, caused relatively more definite and probable infections (10 of 19 strains, 52.6%). Overall, women of 50 years of age or older were more prone to M. avium infection than younger women or men of all ages were. We therefore conclude that M. avium subsp. hominissuis is the dominant M. avium subspecies clinically, that the two bird-type subspecies do cause human infections, and that M. avium infects mainly postmenopausal women. The lack of human clinical isolation of the ruminant type subspecies may need further investigation. N ontuberculous mycobacteria are ubiquitous in the environment and can cause significant disease in animals and humans (1-5). Mycobacterium avium and Mycobacterium intracellulare were the two original main species belonging to the M. avium-M. intracellulare complex (MAIC). M. avium is an important opportunistic pathogen that causes respiratory tract, lymph node, and, occasionally, soft tissue infections in healthy immunocompetent individuals (6, 7). Moreover, secondary infections with M. avium have gained increased attention over the decades due to the longevity of the immunocompromised population, i.e., individuals living with HIV and AIDS, and the administration of immunosuppressive chemotherapeutics in cancer patients (8).With the development of new molecular identification methods, M. avium has been further subdivided into four major subspecies: M. avium subsp. avium, M. avium subsp. paratuberculosis, M. avium subsp. silvaticum, and M. avium subsp. hominissuis (9, 10), each with distinct pathogenic characteristics and host preference and all considered possible zoonoses. These M. avium subspecies are considered to be a broad group, particularly M. avium subsp. avium and M. avium subsp. paratuberculosis as independently evolved pathogenic clones (9, 10).

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Mycobacterium : Laboratory Characteristics of Slowly Growing Mycobacteria Other than Mycobacterium tuberculosis

Caulfield,

Richter,

Brown‐Elliott

et al. 2023

ClinMicroNow

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This chapter describes the clinically significant, slowly growing nontuberculous mycobacteria (SGM). Pulsed‐Field Gel Electrophoresis has been a useful technique for strain typing of the SGM. It is important to recognize that an unidentified mycobacterial isolate should be treated as if it is M. tuberculosis and that appropriate safety measures, including biosafety level 3 practices and facilities, should be used until M. tuberculosis is ruled out. One of the first, easiest, and least expensive means of detecting the presence of mycobacteria in clinical samples is microscopic examination. Matrix‐assisted laser desorption ionization‐time‐of‐flight mass spectrometry has revolutionized the identification of microorganisms, including mycobacteria. Not all laboratories may have the necessary funds, facilities, or instrumentation to provide molecular testing in mycobacteriology. Antimicrobial susceptibility testing of clinically relevant mycobacteria is important for the treatment of infections caused by many mycobacterial species.

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Genetic Diversity of Mycobacterium avium Isolates Recovered from Clinical Samples and from the Environment: Molecular Characterization for Diagnostic Purposes

Abstract: Isolation of

Cited by 30 publications

References 40 publications

Efficient Differentiation ofMycobacterium aviumComplex Species and Subspecies by Use of Five-Target Multiplex PCR

Efficient Differentiation ofMycobacterium aviumComplex Species and Subspecies by Use of Five-Target Multiplex PCR

Subspecies Identification and Significance of 257 Clinical Strains of Mycobacterium avium

Mycobacterium : Laboratory Characteristics of Slowly Growing Mycobacteria Other than Mycobacterium tuberculosis

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