Mycobacterium thermoresistibile infection in an immunocompromised host

Disseminated Mycobacterium thermoresistibile Infection presented with Lymphadenectasis in an AIDS patient: case report and review of literature

BACKGROUND

Nontuberculous mycobacteria disease is a common invasive infectious disease in patients with HIV. However, Mycobacterium thermoresistibile association with lymphadenectasis is unusual in AIDS patients.

CASE PRESENTATION

This report covers the case of a 25-year-old male AIDS patient infected with Mycobacterium thermoresistibile. The case was identified via pathogen-targeted next-generation sequencing (ptNGS).

CONCLUSION

This is the first report of disseminated M. thermoresistibile infection presented with lymphadenectasis in an AIDS patient. Prompt diagnosis and antimicrobial treatment are crucial.

Infection due to Mycobacterium thermoresistibile: a case associated with an orthopedic device

Mycobacterium thermoresistibile is a rapidly growing environmental nontuberculous mycobacterium, seldom reported in human infections. Here, we describe a rare case of tibial-nail-related osteomyelitis due to Mycobacterium thermoresistibile. We also review the literature about the infections caused by this pathogen.

Mycobacterium thermoresistibile as a source of thermostable orthologs of Mycobacterium tuberculosis proteins

The genus Mycobacterium comprises major human pathogens such as the causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), and many environmental species. Tuberculosis claims ~1.5 million lives every year, and drug resistant strains of Mtb are rapidly emerging. To aid the development of new tuberculosis drugs, major efforts are currently under way to determine crystal structures of Mtb drug targets and proteins involved in pathogenicity. However, a major obstacle to obtaining crystal structures is the generation of well-diffracting crystals. Proteins from thermophiles can have better crystallization and diffraction properties than proteins from mesophiles, but their sequences and structures are often divergent. Here, we establish a thermophilic mycobacterial model organism, Mycobacterium thermoresistibile (Mth), for the study of Mtb proteins. Mth tolerates higher temperatures than Mtb or other environmental mycobacteria such as M. smegmatis. Mth proteins are on average more soluble than Mtb proteins, and comparison of the crystal structures of two pairs of orthologous proteins reveals nearly identical folds, indicating that Mth structures provide good surrogates for Mtb structures. This study introduces a thermophile as a source of protein for the study of a closely related human pathogen and marks a new approach to solving challenging mycobacterial protein structures.

Mycobacterium thermoresistibile: case report of a rarely isolated mycobacterium from Europe and review of literature

Mycobacterium thermoresistibile is a non-tuberculous mycobacterium strongly associated with human infections. Since 1966, there have only been six reports of its isolation from clinical samples. We report on the first case from Europe and review all the previous cases. Identification was achieved with sequencing of the 16S rRNA and hsp65 genes. This study presents its phenotypic and biochemical profile, susceptibilities to selected antibiotics and hsp65 polymerase chain reaction-restriction fragment length polymorphism profile with BsteII and Hae III .

Mycobacterium thermoresistibile infection following knee-replacement surgery

We report a case of Mycobacterium thermoresistibile as a cause of infection following total knee replacement. This infection was masked by the prior isolation of a vancomycin-resistant enterococcus. The infection was resolved with long-term therapy using moxifloxacin and doxycycline.

Chronic pneumonia caused by Mycobacterium thermoresistibile in a cat

Mycobacterium thermoresistibile was isolated in pure culture from ultrasound-guided pulmonary aspirates taken from a young cat with severe, chronic, pyogranulomatous pneumonia. Thoracic radiography and ultrasonography before therapy demonstrated severe diffuse alveolar disease. Twelve months combination therapy with doxycycline, rifampicin and clarithromycin resolved the infection. Thoracic radiographs taken at the completion of therapy showed multifocal pulmonary mineralisation. M thermoresistibile has been infrequently reported as a human or animal pathogen. This is the first reported pulmonary infection by M thermoresistibile in a cat and documents the successful treatment of the organism in a feline patient.

Isoelectric focusing patterns of beta-lactamases in the rapidly growing mycobacteria

beta-lactamases from 259 strains of rapidly growing mycobacteria that included the third biovariant complex of Mycobacterium fortuitum, M. peregrinum, M. abscessus, M. chelonae, the M. chelonae-like organisms (MCLO), and M. smegmatis were analyzed by isoelectric focusing (IEF). All isolates produced acidic beta-lactamases with major band isoelectric points (pIs) between 4.4 and 6.0. Each of the 6 taxonomic groups exhibited 1 or 2 characteristic beta-lactamase IEF patterns. Heterogeneity among IEF patterns was evident in 5 of the 6 groups, however, and was greatest among the third biovariant complex of M. fortuitum. beta-lactamase patterns correlated with previously identified taxonomic subgroups of M. smegmatis and the third biovariant complex of M. fortuitum. beta-lactamase IEF analysis of MCLO strains isolated from two outbreaks demonstrated its possible usefulness for epidemiologic evaluation.

Isolation of Mycobacterium thermoresistibile following augmentation mammaplasty

This is the first case report of a Mycobacterium thermoresistibile infection following augmentation mammaplasty and is the fourth human case report of M. thermoresistibile infection. Antimicrobial susceptibility results determined by a modified proportion method using a 3-day incubation were the same as those determined by the standard 3-week assay.

Agents of newly recognized or infrequently encountered mycobacterial diseases

This paper reviews recent information on the systematics and clinical significance of potentially pathogenic environmental mycobacteria. A short history of these mycobacteria is given. Information on species for which clinical and systematic aspects have already been well documented, i.e., Mycobacterium kansasii, M. marinum, M. scrofulaceum, M. simiae, M. szulgai, M. ulcerans, M. xenopi, and members of the M. fortuitum complex, is updated. Although the M. avium complex was extensively reviewed in earlier literature, major new systematic and clinical information is presented in some detail. Species that have received very limited prior coverage, i.e., M. asiaticum, M. haemophilum, M. malmoense, and M. shimoidei, are the main subjects of this review and are discussed in detail. The rare infections attributed to species that are normally considered nonpathogenic, i.e., M. gastri, M. gordonae, the M. terrae complex, and most of the rapidly growing mycobacteria outside of the M. fortuitum complex, are critically reviewed. Finally, suggestions are offered for practical measures that can minimize the risk of failing to isolate or misidentifying some of the more obscure potentially pathogenic environmental mycobacteria that are only infrequently recognized.

Differentiation of Mycobacterium thermoresistibile from Mycobacterium phlei and other rapidly growing mycobacteria

Mycobacterium thermoresistibile is the only chromogenic rapidly growing mycobacterial species reported to cause infections in humans and animals. DNA-DNA hybridization (S1 nuclease method) showed that M. thermoresistibile formed a DNA relatedness group which was only 24 to 30% related to M. phlei. Alkaline phosphatase and beta-galactosidase differentiated M. thermoresistibile from M. phlei. Among the rapidly growing mycobacteria, the mycolic acid pattern of M. thermoresistibile was unique (alpha-, alpha'-, methoxy-and keto-mycolates). Fourteen other species of chromogenic rapidly growing mycobacteria, including M. phlei, produced different mycolic acid patterns which always included dicarboxylic mycolate. Nine species of non-chromogenic rapidly growing mycobacteria produced mycolic acid patterns devoid of ketomycolate.

Mycobacterium thermoresistibile: extrapulmonary infection in a cat

The first evidence of the potential pathogenicity of Mycobacterium thermoresistibile in cats is presented. This mycobacterium was isolated repeatedly from intra- and subcutaneous nodules, aspirated fluid from fluctuating skin lesions, and lymph nodes. The distinctive characteristics of the cultured organisms matched those of M. thermoresistibile.