RESUMO
We isolated a Mycobacterium sp. resembling Mycobacterium marinum and M. ulcerans from diseased striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. This isolate may represent an undescribed Mycobacterium species, based on phenotypic characteristics and comparative 16S rRNA gene sequence.
Assuntos
Bass/microbiologia , Doenças dos Peixes/microbiologia , Infecções por Mycobacterium/veterinária , Mycobacterium/classificação , Mycobacterium/isolamento & purificação , Animais , Doenças dos Peixes/epidemiologia , Genes de RNAr , Dados de Sequência Molecular , Mycobacterium/genética , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/microbiologia , Fenótipo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Úlcera Cutânea/microbiologia , Úlcera Cutânea/veterináriaRESUMO
Mycobacterium abscessus and Mycobacterium chelonae are two closely related species that are often not distinguished by clinical laboratories despite the fact they cause diseases requiring different treatment regimens. Multilocus enzyme electrophoresis, PCR-restriction fragment length polymorphism analysis of the 65-kDa heat shock protein gene, biochemical tests, and high-performance liquid chromatography of mycolic acids were used to identify 75 isolates as either M. abscessus or M. chelonae that were originally submitted for drug susceptibility testing. Only 36 of these isolates were submitted with an identification at the species level. Using the above methods, 46 of the isolates were found to be M. abscessus and 29 were identified as M. chelonae. Eight isolates originally submitted as M. chelonae were identified as M. abscessus, and one isolate submitted as M. abscessus was found to be M. chelonae. The four identification methods were in agreement in identifying 74 of the 75 isolates. In drug susceptibility testing, all isolates of M. abscessus exhibited resistance to tobramycin (MIC of 8 to > or =16 microg/ml), while all isolates of M. chelonae were susceptible to this drug (MIC of < or = 4 microg/ml). The results suggest that once an identification method is selected, clinical laboratories should be able to easily identify isolates of M. abscessus and M. chelonae.
Assuntos
Proteínas de Bactérias , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium chelonae/classificação , Micobactérias não Tuberculosas/classificação , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Chaperonina 60 , Chaperoninas/genética , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Ágar/métodos , Enzimas/análise , Humanos , Testes de Sensibilidade Microbiana/métodos , Mycobacterium chelonae/efeitos dos fármacos , Mycobacterium chelonae/genética , Mycobacterium chelonae/isolamento & purificação , Mycobacterium chelonae/metabolismo , Ácidos Micólicos/análise , Micobactérias não Tuberculosas/genética , Micobactérias não Tuberculosas/isolamento & purificação , Micobactérias não Tuberculosas/metabolismo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de RestriçãoRESUMO
The Mycobacterium avium complex (MAC) is an important cause of cervical lymphadenitis in children, and its incidence appears to be increasing in the United States and elsewhere. In areas where Mycobacterium tuberculosis is not prevalent, M. avium causes the vast majority of cases of mycobacterial lymphadenitis, although several other nontuberculous mycobacterial species have been reported as etiologic agents. This report describes the case of a child with cervical lymphadenitis caused by a nontuberculous mycobacterium that could not be identified using standard methods, including biochemical reactions and genetic probes. Direct 16S ribosomal DNA sequencing showed greater than 99% homology with Mycobacterium triplex, but sequence analysis of the 283-bp 16S-23S internal transcribed spacer (ITS) sequence showed only 95% identity, suggesting that it is a novel species or subspecies within a complex of organisms that includes M. triplex. Mycolic acid high-performance liquid chromatography analysis also identified this isolate as distinct from M. triplex, and differences in susceptibility to streptomycin and rifampin between this strain and M. triplex were also observed. These data support the value of further testing of clinical isolates that test negative with the MAC nucleic acid probes and suggest that standard methods used for the identification of mycobacteria may underestimate the complexity of the genus Mycobacterium. ITS sequence analysis may be useful in this setting because it is easy to perform and is able to distinguish closely related species and subspecies. This level of discrimination may have significant clinical ramifications, as closely related organisms may have different antibiotic susceptibility patterns.
Assuntos
DNA Espaçador Ribossômico/genética , Linfadenite/microbiologia , Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Mycobacterium/genética , Sequência de Bases , Pré-Escolar , DNA Bacteriano/genética , Feminino , Humanos , Dados de Sequência Molecular , Mycobacterium/isolamento & purificação , Pescoço , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Análise de Sequência de DNARESUMO
A previously uncharacterized, slowly growing, scotochromogenic Mycobacterium species was detected by HPLC analysis of the cell-wall-bound mycolic acids. The mycolic acid pattern standard was shown to be a late-eluting, contiguous peak cluster occurring at approximately 8-9 min. The mycolic acid pattern was noted to be most similar in number of peaks and range of elution to that reported previously for Mycobacterium asiaticum. However, the relative distribution of peaks within the elution range demonstrated a pattern with prominent peaks that started to emerge later than the characteristic M. asiaticum pattern. Standard biochemical identification test results were similar to those of the photochromogenic species M. asiaticum. Comparative 16S rRNA gene sequence analysis confirmed the genetic uniqueness of the strains and demonstrated the unclassified mycobacteria to be in a unique, intermediate position between slow and rapid growers in the phylogenetic tree of Mycobacterium. The name Mycobacterium kubicae sp. nov. is proposed for this taxon. The type strain is CDC 941078T (= ATCC 700732T = CIP 106428T).
Assuntos
Mycobacterium/classificação , Mycobacterium/crescimento & desenvolvimento , Pigmentos Biológicos/análise , Sequência de Bases , Cromatografia Líquida de Alta Pressão , DNA Ribossômico/análise , DNA Ribossômico/genética , Genes de RNAr , Dados de Sequência Molecular , Mycobacterium/química , Mycobacterium/fisiologia , Ácidos Micólicos/análise , Filogenia , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Análise de Sequência de DNAAssuntos
Traumatismos do Pé/complicações , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium fortuitum/isolamento & purificação , Osteomielite/microbiologia , Ossos do Tarso/microbiologia , Ferimentos Penetrantes/complicações , Criança , Diagnóstico Diferencial , Doenças do Pé/microbiologia , Humanos , Masculino , Infecções por Mycobacterium não Tuberculosas/terapia , Nocardiose/diagnóstico , Radiografia , Ossos do Tarso/diagnóstico por imagemRESUMO
Rapidly growing mycobacteria are capable of causing several clinical diseases in both immunosuppressed and immunocompetent individuals. A previously unidentified, rapidly growing mycobacterium was determined to be the causative agent of central line sepsis in a child with underlying metastatic hepatoblastoma. Four isolates of this mycobacterium, three from blood and one from the central venous catheter tip, were studied. Phenotypic characterization, HPLC and genetic analysis revealed that while this organism most closely resembled members of the Mycobacterium fortuitum complex and Mycobacterium senegalense, it differed from all previously described species. Phenotypic tests useful in differentiating this species from similar rapidly growing mycobacteria included: growth at 42 degrees C, hydrolysis of acetamide, utilization of citrate, production of arylsulfatase (3-d), acidification of D-mannitol and i-myo-inositol, and susceptibility to erythromycin, vancomycin and tobramycin. The name Mycobacterium septicum is proposed for this new species. The type strain has been deposited in Deutsche Sammlung von Mikroorganismen und Zellkulturen as DSM 44393T and in the American Type Culture Collection as strain ATCC 700731T.
Assuntos
Bacteriemia/microbiologia , Cateterismo Venoso Central , Cateteres de Demora/microbiologia , Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Mycobacterium/isolamento & purificação , Composição de Bases , Cromatografia Líquida de Alta Pressão , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes de RNAr , Genótipo , Humanos , Dados de Sequência Molecular , Mycobacterium/fisiologia , Ácidos Micólicos/análise , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Polyphasic taxonomic methods were employed to characterize a new species of slowly growing, nonpigmented mycobacteria. We propose the name Mycobacterium triplex sp. nov. for this new taxon. Conventional identification testing demonstrated a group of similar organisms that were geographically widespread in the United States. Commercially available nucleic-acid probes specific for the Mycobacterium avium complex were unreactive for these strains. High-performance liquid chromatography analysis of the mycolic acids revealed mycolate profiles that closely resembled Mycobacterium simiae. Comparative 16S rRNA sequence data confirmed the phylogenetic relationship of the strains with the slowly growing mycobacteria. Representative-type strains have been deposited in the American Type Culture Collection as strain ATCC 700071 [corrected].
Assuntos
Mycobacterium/classificação , Mycobacterium/isolamento & purificação , Técnicas de Tipagem Bacteriana , Sequência de Bases , Primers do DNA/genética , Humanos , Dados de Sequência Molecular , Mycobacterium/genética , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/microbiologia , Complexo Mycobacterium avium/classificação , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Terminologia como Assunto , Estados Unidos/epidemiologiaRESUMO
A new slowly growing nonphotochromogenic Mycobacterium species of clinical importance is described. The biochemical characteristics of this organism were similar to those of Mycobacterium xenopi and members of the Mycobacterium avium complex. However, none of the strains reacted with commercially available genetic probes for the M. avium complex. The strains were resistant to most antituberculosis drugs. Multilocus enzyme electrophoresis revealed two original electrophoretic types, which was suggestive of new species. The strains contained alpha-, keto-, and dicarboxylic mycolates, as determined by thin-layer chromatography. A mycolic acid analysis by high-performance liquid chromatography revealed a chromatographic pattern similar to that of M. xenopi, but distinct from the patterns of previously described Mycobacterium species. Hexadecanoic and tuberculostearic acids were identified as the major cell wall fatty acids by gas-liquid chromatographic analysis; hexacosanoic acid was the major mycolic acid cleavage product, and 2-eicosanol was the major alcohol. Evaluation of the 16S rRNA sequence confirmed the phylogenetic position of the organism among the slowly growing Mycobacterium species. Cultures representing this new species have been deposited in the American Type Culture Collection as strains ATCC 51130 and ATCC 51131T (T = type strain). The name Mycobacterium celatum is proposed.
Assuntos
Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Técnicas de Tipagem Bacteriana , Sequência de Bases , DNA Ribossômico/genética , Ácidos Graxos/análise , Genes Bacterianos , Proteínas de Choque Térmico/genética , Humanos , Dados de Sequência Molecular , Mycobacterium/isolamento & purificação , Infecções por Mycobacterium/epidemiologia , Ácidos Micólicos/análise , Filogenia , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética , Homologia de Sequência do Ácido Nucleico , Estados Unidos/epidemiologiaRESUMO
Two hundred mycobacterial cultures were used to evaluate two alkaline-phosphatase-labeled DNA probe (SNAP) kits developed by Syngene (San Diego, CA) for identification of Mycobacterium tuberculosis complex and M. avium complex. The M. tuberculosis complex SNAP probe, when compared with standard biochemical identification tests, gave results that were in agreement at 100% sensitivity and 98.7% specificity. Ninety-nine M. avium complex strains that were previously tested by the Gen-Probe M. avium complex probe assays and mycolic acid analysis were included to evaluate the M. avium complex SNAP assay which contained three probes, A (avium), I (intracellulare), and X. Eight strains identified as members of the M. avium complex by biochemical tests did not react with the three SNAP probes. These strains were also negative by the Gen-Probe assays. However, 23 strains identified as M. avium complex by biochemical tests and mycolic acid analysis and negative with the Gen-Probe assays gave positive results with the X probe and negative results with the A and I probes of the SNAP assay.
Assuntos
DNA Bacteriano/análise , Complexo Mycobacterium avium/classificação , Mycobacterium tuberculosis/classificação , Sondas de Oligonucleotídeos , Fosfatase Alcalina , Estudos de Avaliação como Assunto , Complexo Mycobacterium avium/genética , Complexo Mycobacterium avium/isolamento & purificação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Kit de Reagentes para Diagnóstico , Sensibilidade e EspecificidadeRESUMO
Profile analysis of mycolic acid ester patterns of Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium bovis bacillus Calmette-Gúerin (BCG) using high-performance liquid chromatography indicated that separation of BCG from M. tuberculosis and M. bovis by elution and relative retention times is possible. Mycolic acid patterns of BCG eluted from the column 0.5 min before M. tuberculosis or M. bovis, resulting in relative retention times for two peaks not seen in the pattern of M. tuberculosis or M. bovis. Identification was confirmed by phage typing, which has been the standard procedure for confirmation of BCG strains. These results showed that high-performance liquid chromatographic analysis of mycolic acid esters can be used in the mycobacterial reference laboratory for separation of BCG from M. tuberculosis and M. bovis.
Assuntos
Mycobacterium bovis/química , Mycobacterium tuberculosis/química , Ácidos Micólicos/análise , Tipagem de Bacteriófagos , Cromatografia Líquida de Alta Pressão , Mycobacterium bovis/classificação , Mycobacterium tuberculosis/classificaçãoRESUMO
Recent outbreaks of nosocomial infections caused by organisms identified as the Mycobacterium fortuitum complex suggest that species and subspecies identification is epidemiologically important. In a study of 170 strains, M. fortuitum was differentiated from M. chelonei by nitrate reduction and iron uptake. M. fortuitum was further divided into biovariant fortuitum, biovar peregrinum, and an unnamed third biovar by inositol and mannitol utilization. M. chelonei was further divided into subsp. chelonei, subsp. abscessus, and an unnamed subspecies by tolerance to 5% sodium chloride, utilization of mannitol and sodium citrate, and uptake of iron.