Disseminated Mixed Mycobacterium simiae-Mycobacterium avium Complex Infection in Acquired Immunodeficiency Syndrome

Torres, Ramón A.; Nord, Jill A.; Feldman, Richard D; LaBombardi, Vincent J.; Barr, Michael R.

doi:10.1093/infdis/164.2.432

Cited by 39 publications

(29 citation statements)

References 3 publications

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“…Also, auramine-rhodamine staining with fluorescent microscopy of bone marrow aspirations may be of value (460); however, the positive predictive value of these techniques is variable (35 to 86%), and one cannot exclude M. tuberculosis bacteremia on the basis of a smear alone. Furthermore, mixed infections can occur, and clinicians and laboratorians should be alert to the possibility that the presence of MAC organisms on the culture plate may obscure the detection of M. tuberculosis (143) or coinfection with M. simiae (453). Wiley et al (478) reported on the use of mixed polyclonal antibodies to three species of mycobacteria to detect microorganisms in tissue including bone marrow biopsies (Fig.…”

Section: Direct Detection By Stainingmentioning

confidence: 99%

The Mycobacterium avium complex

1993

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Mycobacterium avium complex (MAC) disease emerged early in the epidemic of AIDS as one of the common opportunistic infections afflicting human immunodeficiency virus-infected patients. However, only over the past few years has a consensus developed about its significance to the morbidity and mortality of AIDS. M. avium was well known to mycobacteriologists decades before AIDS, and the MAC was known to cause disease, albeit uncommon, in humans and animals. The early interest in the MAC provided a basis for an explosion of studies over the past 10 years largely in response to the role of the MAC in AIDS opportunistic infection. Molecular techniques have been applied to the epidemiology of MAC disease as well as to a better understanding of the genetics of antimicrobial resistance. The interaction of the MAC with the immune system is complex, and putative MAC virulence factors appear to have a direct effect on the components of cellular immunity, including the regulation of cytokine expression and function. There now is compelling evidence that disseminated MAC disease in humans contributes to both a decrease in the quality of life and survival. Disseminated disease most commonly develops late in the course of AIDS as the CD4 cells are depleted below a critical threshold, but new therapies for prophylaxis and treatment offer considerable promise. These new therapeutic modalities are likely to be useful in the treatment of other forms of MAC disease in patients without AIDS. The laboratory diagnosis of MAC disease has focused on the detection of mycobacteria in the blood and tissues, and although the existing methods are largely adequate, there is need for improvement. Indeed, the successful treatment of MAC disease clearly will require an early and rapid detection of the MAC in clinical specimens long before the establishment of the characteristic overwhelming infection of bone marrow, liver, spleen, and other tissue. Also, a standard method of susceptibility testing is of increasing interest and importance as new effective antimicrobial agents are identified and evaluated. Antimicrobial resistance has already emerged as an important problem, and methods for circumventing resistance that use combination therapies are now being studied.

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Section: Direct Detection By Stainingmentioning

confidence: 99%

The Mycobacterium avium complex

1993

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“…The GenoType assay identifies coinfections by different mycobacteria, which can result in greater clinical relevance. (4,7,14,17).…”

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GenoType Mycobacterium Assay for Identification of Mycobacterial Species Isolated from Human Clinical Samples by Using Liquid Medium

et al. 2002

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The GenoType Mycobacterium assay was used to identify 98 mycobacteria isolates by using liquid cultures from positive BACTEC, MGIT, and ESP bottles. This system identifies 16 mycobacteria. There was complete agreement between the GenoType results and the laboratory identifications for Mycobacterium tuberculosis complex and other Mycobacterium spp. GenoType also identified mixed mycobacterial infections.While Mycobacterium tuberculosis complex strains are still responsible for the majority of mycobacterium infections worldwide, opportunistic infections caused by mycobacteria other than M. tuberculosis have increased, mainly as a consequence of several factors such as the AIDS epidemic (2). The use of culture in liquid media in clinical mycobacteriology laboratories improves the ability to detect growth of Mycobacterium spp. (11). Identification of a mycobacterium growing on solid medium can be done by biochemical methods, such as thin-layer chromatography (5), gas-liquid chromatography (16), high-performance liquid chromatography (HPLC), DNA probes, or direct sequencing (3,13,15). Reverse hybridization assays can be performed directly from liquid culture for rapid identification of M. tuberculosis complex (9). Unfortunately, these tests only detect a limited number of mycobacteria species of clinical significance other than M. tuberculosis.The GenoType assay (Hain Diagnostika, Nehren, Germany) allows for the identification of 16 different mycobacterial species that are most frequently isolated in the clinical laboratory. Isolation is commonly done by PCR amplification of the 16S-23S ribosomal DNA spacer region followed by hybridization of the biotinylated amplified DNA products with 16 specific oligonucleotide probes. The specific probes are immobilized as parallel lines on a membrane strip (1). The goal of this study was to evaluate the GenoType assay for the identification and differentiation of specific mycobacteria species directly from positive liquid cultures, an approach not previously published for this assay.The GenoType assay was evaluated for specificity and speed of the procedure in a routine clinical laboratory. Ninety-eight clinical specimens from different patients were submitted for culture, decontaminated with an equal volume of N-acetyl cysteine-4% NaOH, and concentrated by centrifugation. The sediment was used to inoculate Middlebrook 7H11 agar, BACTEC 12B broth, MGIT broth, and ESPII Myco broth. The cultures were incubated at 37°C for 6 weeks according to the manufacturer's instructions. When a BACTEC culture had a growth index (GI) of Ϸ100, it was visibly positive by ZiehlNeelsen stain. In MGIT the microscopy was positive from 100 growth units (GU), and in ESPII the microscopy was positive the same day as the culture was identified as positive by the ESP instrument. In those positive cultures with values lower than the ones mentioned, results with the stain were negative and the absence of contamination was confirmed.Positive cultures were identified by DNA probes (Accuprobe; Gen-Probe, Inc.)...

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“…Since the faint signal produced by N3/N5 PCR from a clinical isolate of M. tuberculosis in this study showed 100% homology to IS1311 and a GenBank search did not reveal any sequence homology of the amplified 130-bp fragment with genomic sequences of M. tuberculosis, a mixed infection or cross-contamination with NTM during culture is the most likely explanation (13,17,18). However, this hypothesis could not be tested, since the strain was no longer viable.…”

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confidence: 73%

Evidence of the Presence of IS 1245 and IS 1311 or Closely Related Insertion Elements in Nontuberculous Mycobacteria outside of the Mycobacterium avium Complex

et al. 2002

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A PCR assay based on the simultaneous detection of IS1245 and IS1311 was developed and used to determine the host range of these insertion elements. Specific PCR products were observed in Mycobacterium malmoense, Mycobacterium scrofulaceum, and Mycobacterium nonchromogenicum, indicating that IS1245 and IS1311 are not limited to the Mycobacterium avium complex.The 1,414-bp insertion element IS1245 belongs to the Staphylococcus aureus IS256 family of insertion sequences. It is present in up to 27 copies in Mycobacterium avium (8) and was found to be stable during in vivo and in vitro passage (1, 14), making it a popular target for restriction fragment length polymorphism strain typing in recent years (5,6,12,19). The host range was originally demonstrated to be limited to the M. avium group (M. avium and subspecies paratuberculosis and silvaticum) by PCR amplification of a 427-bp target sequence within IS1245, leading to its use as a species-specific target for diagnostic detection (11).Recently, Beggs et al. found IS1245 in strains of Mycobacterium intracellulare, demonstrating that the element is present in further species of the M. avium complex (MAC) (2).A closely related insertion element, IS1311 (85% sequence identity to IS1245 at the DNA level), has likewise been used as a target for restriction fragment length polymorphism strain typing of M. avium (5,15,16).In our laboratory, a PCR assay based on the simultaneous detection of a highly homologous 130-bp portion of IS1245 and IS1311 (91% sequence identity) was developed as a diagnostic tool for detection of MAC in clinical specimens and used to determine the host range of these elements.Mycobacterial strains were received from five collaborating mycobacterial laboratories. Species of nontuberculous mycobacteria (NTM) were identified by 16S ribosomal DNA (rDNA) sequencing (10) and/or 23S rDNA probes (GenoType; Hain Diagnostika, Nehren, Germany). Twelve NTM strains (1 Mycobacterium shimoidei strain, 1 Mycobacterium scrofulaceum strain, 6 M. intracellulare strains, 2 Mycobacterium malmoense strains, 1 Mycobacterium chelonae strain, and 1 Mycobacterium szulgai strain) were identified by a combination of standard biochemical methods (9) and high-performance liquid chromatography (4).Cells were lysed by incubation at 100°C for 5 min in the presence of 2 M NaOH and 4% Triton. Crude lysates or DNA purified using QIAamp spin columns (Qiagen, Hilden, Germany) were used as PCR templates.PCR analysis of NTM strains was performed by two independent laboratories (Lab 1 and Lab 2). Amplification was performed on GeneAmp PCR systems 9600 and 2400 (PerkinElmer, Weiterstadt, Germany). A 100-l reaction mixture contained 1 mM MgCl 2, 320 mol of deoxynucleoside triphosphates, 5 U of AmpliTaq Gold (GeneAmp; Perkin-Elmer), 100 pmol of each primer, and 5 to 10 l of lysate with 0.1 to 1 ng of template DNA in 1ϫ PCR Buffer II (Perkin-Elmer). The sense primer N3 (5Ј ACTTCCTGCGCAACGTGCT 3Ј) recognized positions 885 to 903 of IS1245 (GenBank accession no. L33879) and positions 823 to 8...

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Disseminated Mixed Mycobacterium simiae-Mycobacterium avium Complex Infection in Acquired Immunodeficiency Syndrome

Cited by 39 publications

References 3 publications

The Mycobacterium avium complex

The Mycobacterium avium complex

GenoType Mycobacterium Assay for Identification of Mycobacterial Species Isolated from Human Clinical Samples by Using Liquid Medium

Evidence of the Presence of IS 1245 and IS 1311 or Closely Related Insertion Elements in Nontuberculous Mycobacteria outside of the Mycobacterium avium Complex

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