A Case of Mycobacterium gordonae Pulmonary Disease in a Patient with Ulcerative Colitis Treated with Infliximab / 대한내과학회지

Tumor necrosis factor-alpha (TNF-alpha) is a key component of the host defense against mycobacterial infection. Mycobacterium gordonae (M. gordonae) is one of the least virulent mycobacteria, and is generally considered non-pathogenic if detected from a clinical specimen. Here, we report a rare case of pulmonary M. gordonae infection in a patient with ulcerative colitis who had been treated with infliximab, a TNF-alpha antagonist. M. gordonae infection was treated successfully with clarithromycin, rifampin, and ethambutol. We believe this to be the first report of M. gordonae pulmonary disease associated with TNF-alpha antagonist treatment.

Plastic Expander-Related Gordonia Sputi Infection: Case Report and Literature Review / 生物医学与环境科学（英文）

Gordonia sputi causes rare bacterial infections resulting from a contaminated indwelling medical device. We report the case of a postoperative plastic expander abscess in a woman, with G. sputi identification by 16S ribosomal RNA sequencing. This report indicates that Gordonia spp. should be included in the list of organisms causing plastic implant infections.

Isolation Trend of Nontuberculosis Mycobacteria at a Tertiary-care Hospital in 2003-2011 / 고신대학교의과대학학술지

OBJECTIVES: This study was performed to investigate the prevalence of nontuberculous mycobacteria (NTM) species and to determine the clinical significance of NTM isolates. METHODS: From January 2003 to July 2011, NTMs were identified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or reverse blot hybridization assay (REBA). And pulmonary NTM infection was diagnosed by clinical history, underlying disease, radiological and microbiological findings according to the diagnostic criteria of 2007 American Thoracic Society (ATS). RESULTS: Of the 697 AFB culture-positive specimens, NTM was detected in 149 (21.4%) specimens. Among 154 NTM isolates from 149 specimens, M. avium-intracellulare complex (MAC) (48.1%) was the most frequently isolated organisms followed by M. abscessus (13.6%), M. gordonae (9.1%), M. kansasii (8.4%), M. szulgai (3.9%), M. fortuitum complex (3.3%), M. scrofulaceum (2.0%), M. malmoense (1.3%), M. chelonae (1.3%), M. marinum (1.3%), M. genavense (1.3%), M. lentiflavum (1.3%) and M. mucogenicum (0.6%). Among 147NTM isolates from 142 respiratory specimens, 54 NTM isolates (36.7%) were causative organisms in NTM pulmonary infection. CONCLUSIONS: The isolation rate of NTM was 21.4% in clinical specimen, and in some cases NTM species results in pulmonary NTM infection. Because the treatment of pulmonary NTM infection depends on the infecting species, accurate identification and clinical significance of NTM are required for adequate treatment.

Gordonia polyisoprenivorans from groundwater contaminated with landfill leachate in a subtropical area: characterization of the isolate and exopolysaccharide production

Uma linahgem de Gordonia sp. (linhagem Lc), proveniente de águas subterrâneas contaminadas por chorume, foi caracterizada por taxonomia polifásica e estudada quanto à produção de exopolissacarídeos (EPS). As células, bastonetes agregados, isolados ou aos pares em formato de V, típico de bactérias corineformes, apresentaram reação Gram positiva, catalase positiva, oxidase negativa, não apresentaram motilidade. O organismo cresceu em aerobiose e em ambiente anóxico na presença de NaNO3. A linhagem apresentou características morfológicas, bioquímicas e propriedades quimiotaxônomicas típicas do gênero Gordonia e perfil de ácidos micólicos e ácidos graxos correspondentes aos de G. polyisoprenivorans DSM44302T. A análise do seqüenciamento dos primeiros 500 pares de bases do rDNA16S da linhagem mostrou 100 po cento de similaridade com Gordonia polyisoprenivorans DSM44302T. Experimentos conduzidos em condições anaeróbias em meio E com sacarose ou glicose como principal fonte de carbono, mostraram que a linhagem não cresceu quando cultivada com sacarose. Entretanto, utilizando-se glicose, a velocidade específica máxima de crescimento foi 0,17h-1, o tempo de geração de aproximadamente 4 horas e o máximo de produção de EPS total ocorreu durante a fase exponencial (126,17 ± 15,63 g l-1). A produção de EPS livre excedeu à de capsular e a relação EPS livre/EPS capsular aumentou de 1,9, durante a fase exponencial para 7,8 durante a fase estacionária. Até então, foram isoladas seis linhagens de G. polyisoprenivorans de diferentes ambientes. A linhagem Lc é a sexta linhagem de G. polyisoprenivorans descrita, a segunda detectada nas águas subterrâneas em questão e a primeira cuja produção de EPS está sendo estudada.

Identification of Nontuberculous Mycobacteria by Sequence Analysis of the 16S Ribosomal RNA, the Heat-shock Protein 65 and the RNA Polymerase beta-Subunit Genes / 대한진단검사의학회지

BACKGROUND: The diagnosis of diseases caused by nontuberculous mycobacteria (NTM) is difficult, because NTM are prevalent in the environment such as soil and water, and because they have fastidious properties. In this study we investigated clinical isolates of NTM for their distribution pattern and accurate species identification. METHODS: We selected presumptive NTM isolates negative for probe hybridization for M. tuberculosis complex, cultured in a third referral hospital from 21 January 2003 to 20 January 2004. Ninety seven-isolates were identified to the species level by direct sequencing of fragments of 16S rRNA, hsp65 and rpoB genes. A total of 120 isolates were studied for the distribution analysis. RESULTS: Frequently identified NTM species were M. avium (30.8%), M. intracellulare (23.3%) and M. abscessus (18.3%). Others were M. gordonae, M. senegalense, M. fortuitum, M. peregrinum, M. kansasii, M. terrae complex, M. lentiflavum, M. chelonae, and M. szulgai. Three M. tuberculosis complex (2.5%) were also identified among the presumptive NTM isolates. The identification rate by sequencing of 16S rRNA, rpoB, and hsp65 were 65%, 82% and 87%, respectively. The hsp65 or rpoB gene was more efficient than 16S rRNA for the identification of NTM by sequencing. CONCLUSIONS: Some NTM are increasingly considered to be the causative organisms in clinical diseases. Thus, direct sequencing could be adapted to routine work of clinical laboratories for accurate identification of NTM to the species level.

Clinical Significance of Low-colony Count Scotochromogen Nontuberculous Mycobacteria / 결핵및호흡기질환

BACKGROUND: Even though it has been suggested that low-colony, scotochromogen nontuberculous mycobacteria (NTM) are usually contaminants and not true pathogens, evidence for this hypothesis has not been provided. This study investigated the colony characteristics, organism identification, and clinical significance of low-colony scotochromogen. METHODS: The laboratory cultured 6,898 respiratory clinical specimens for an examination of mycobacteria over a three-month period. A low-colony count was arbitrarily defined as < or = 20 colonies. This study analyzed the recovery rate of the mycobacteria, the number of colonies and their gross characteristics, and their clinical significance. PCR- restriction fragment length polymorphism analysis was carried out to identify the NTM species. NTM pulmonary disease was defined according to the American Thoracic Society. RESULTS: A total of 6,898 respiratory specimens for mycobacterium were cultured. Of these, 263 (3.8%) grew NTM, and 382 (5.5%) grew M. tuberculosis. Of the 263 cultured NTM specimens, 124 (47.1%) were scotochromogens. The smear-positive rate was significantly lower in these scotochromogens (4.8%) than in the non-scotochromogens (23.7%) (p<0.05). The most common isolates were M. gordonae (83/102, 81.4%) in the scotochromogens, and MAC (52/121, 43.0%) in the non-scotochromogens. Even though three out of 113 patients with a low-colony scotochromogen has been diagnosed with NTM pulmonary disease, the isolated scotochromogen was not considered to be the cause of the NTM disease but was just a contaminant. CONCLUSION: In this study, the most common isolate of a low-colony count scotochromogen was M. gordonae, which appeared to be contaminants and not true pathogens. Greater efforts in the quality control of a mycobacterium laboratory are needed in cases where there is a high recovery rate of low-colony count scotochromogen.

Diagnosis and Treatment of Nontuberculous Mycobacterial Pulmonary Diseases

Eight years before the Robert Koch's identification of Mycobacterium tuberculosis, Mycobacterium leprae, which is the firstly identified nontuberculous mycobacteria (NTM), was reported by G.H. Armauer Hansen in 1874. Thereafter a total of 71 species of Mycobacterium have been recognized or proposed. Despite the fact that NTM have been occasionally identified from clinical specimens, it is only recently that they draw a serious attention. In Korea, the frequency of isolation of NTM increased from 448 in 1992 to 1562 in 2002, while the prevalence of active tuberculosis over the same period decreased from 1.8% to 0.5%. The most commonly isolated NTM was M. avium-intracellulare complex (MAC) throughout the period of 1992~2002. M. abscessus was the second common, followed by M. fortuitum, M. gordonae and M. kansasii. In this article, we will overview the NTM-related lung diseases in terms of their diagnosis, clinical characteristics,and treatment.

Clinical Evaluation of 10 Cases of Nontuberculous Mycobacteria Isolated from Sputum / 대한진단검사의학회지

Infections due to Nontuberculous Mycobacteria (NTM) have been recognized increasingly worldwide. We report 10 cases of nontuberculous mycobacteria isolated from sputa, being eight cases of M. szulgai, one of M. gordonae, and one of M. abscessus. All but one M. abscessus-isolating case was developed in the same period in one episode. Therefore, it is likely to be contaminated. NTM is a possible pathogen and infections due to NTM are clinically important. Thus, correct identification and determination of clinical significance should be verified.

Production of glycolipids containing biosurfactant by Pseudomonas species.

Microorganisms, that degrade hydrocarbon were isolated and screened for their biosurfactant activity. A total of 68 strains were isolated and tested for their glycolipid activity of which 4 isolates showed good glycolipid activity. Isolate K10 gave the maximum biosurfactant production in medium A (containing kerosene as a sole carbon source) as compared to medium B (containing glucose as a sole carbon source). Characterization of isolate K10 showed that it belongs to Pseudomonas species.

Identification of Mycobacterium Species by Multiplex PCR-Restriction Fragment Length Polymorphism Assay / 감염

BACKGROUND: Recently the clinical significance of several mycobacterial species has been increased and there is a growing need to identify mycobacteria to the species level. We evaluated multiplex polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assay for identification of mycobacterial isolates. METHODS: Reference strains of 6 species of mycobacteria and 88 clinical isolates were lysed by boiling method. The lysates were used for multiplex PCR reactions incorporating three pairs of PCR primers, which were expected to amplify fragments from the 65-kDa gene common to all mycobacteria, genes of M. tuberculosis complex and M. avium, respectively. The resultant amplicons were digested with the restric-tion enzymes PspEI and HaeIII. Multiplex PCR products and digested products were visualized by electrophoresis on agarose gels. RESULTS: Six reference strains yielded compatible results. Eighty-eight clinical isolates were identified as M. tuberculosis complex (81 strains), M. avium (2 strains), M. intracellulare (2 strains), M. fortuitum biovariant peregrinum (2 strains), and M. gordonae III (1 strain). CONCLUSION: Multiplex PCR-RFLP assay appears to be a reliable method for rapid identification of mycobacteria to species level.

Mycolic Acid Analysis for Identification of Mycobacterium spp. using High-Performance Liquid Chromatography / 대한임상병리학회지

BACKGROUND: Mycobacteria are traditionally identified with biochemical reactions. Since it takes 2 to 6 weeks, more rapid method is needed for timely treatment of mycobacterial infection. Mycolic acid analysis by high-performance liquid chromatography (HPLC) was recently introduced, which showed species-specificity with more than 95% sensitivity and 100% specificity for identifing Mycobacterium spp. within 2-4 hours. In this study, We performed mycolic acid analyses of standard strains of Mycobacterium spp. and two clinical isolates of known M. tuberculosis for demonstrating their species-specific nature and evaluated its reproduciblity. METHODS : 8 standard strains of Mycobacterium spp. (M. tuberculosis H37Rv, M. intracellurae, M. avium, M. fortuitum, M. chelonae subsp. chelonae, M. scrofulaceum, M. kansasii, M. gordonae) and 2 clinical isolates of known M. tuberculosis were analyzed. The extracted mycolic acids which were prepared by 3 steps were analyzed by HPLC with rC18 column. RESULTS: Mean retention time (MRT) of low and high molecular weight internal standards were 3.757min+/-0.017 (C.V. <0.455%) and 9.829min+/-0.015 (C.V. <0.015%), respectively (n=30). The C.V. of MRT for M. intracellurae for positive control showing double cluster pattern was less than 0.3% from 4 injection. The C.V. of MRT for M. tuberculosis H37Rv and 2 clinical isolates of M. tuberculosis with single cluster pattern were less than 0.4%, and 0.9%, respectively. The chromatographic patterns of M. kansasii and M. gordonae showed a single cluster pattern, and M. avium, M. fortuitum, M. chelonae subsp. chelonae, and M. scrofulaceum showed a double cluster pattern which were species-specific nature. CONCLUSIONS: We demonstrated HPLC method was rapid and highly reproducible.