Objective: To understand the etiological characteristics and drug susceptibility of Mycobacterium thermoresistibile and Mycobacterium elephantis isolated from a cow with mastitis and provide evidence for the prevention and control of infectious mastitis in cows. Methods: The milk sample was collected from a cow with mastitis, which was pretreated with 4% NaOH and inoculated with L-J medium for Mycobacterium isolation. The positive cultures were initially identified by acid-fast staining and multi-loci PCR, then Mycobacterium species was identified by the multiple loci sequence analysis (MLSA) with 16S rRNA, hsp65, ITS and SodA genes. The drug sensitivity of the isolates to 27 antibiotics was tested by alamar blue assay. Results: Two anti-acid stain positive strains were isolated from the milk of a cow with mastitis, which were identified as non-tuberculosis mycobacterium by multi-loci PCR, and multi-loci nucleic acid sequence analysis indicated that one strain was Mycobacterium thermoresistibile and another one was Mycobacterium elephantis. The results of the drug susceptibility test showed that the two strains were resistant to most antibiotics, including rifampicin and isoniazid, but they were sensitive to amikacin, moxifloxacin, levofloxacin, ethambutol, streptomycin, tobramycin, ciprofloxacin and linezolid. Conclusions:Mycobacterium thermoresistibile and Mycobacterium elephantis were isolated in a cow with mastitis and the drug susceptibility spectrum of the pathogens were unique. The results of the study can be used as reference for the prevention and control the infection in cows.
Animals ; Anti-Bacterial Agents/pharmacology* ; Antitubercular Agents/pharmacology* ; Cattle ; Drug Resistance, Bacterial ; Female ; Humans ; Mastitis, Bovine/microbiology* ; Microbial Sensitivity Tests ; Milk/microbiology* ; Mycobacterium/isolation & purification* ; Mycobacterium Infections/veterinary* ; Mycobacterium tuberculosis/drug effects* ; Nontuberculous Mycobacteria/isolation & purification* ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics*

We evaluate the performance of Xpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis (EPTB) in China. The performance of Xpert was evaluated compared to the composite reference standard (CRS), drug susceptibility testing (DST), and imaging examination. The overall sensitivity and specificity of Xpert were 64.1% (195/304) and 100% (24/24), respectively, using CRS as the gold standard. The sensitivity was significantly higher than that of culture for pus (P<0.05). The proportion of EPTB-positive cases diagnosed by imaging was two times more than that diagnosed using Xpert; however, 6 out of 19 cases may have been overdiagnosed by imaging. Compared to phenotypic DST, the sensitivity and specificity of Xpert were 80% (12/15) and 100% (75/75), respectively. Considering its high sensitivity and specificity, Xpert MTB/RIF may be used as a rapid initial test for EPTB diagnosis, and may also support a quicker decision on the treatment regimen. The combination of imaging and Xpert testing could provide high efficiency and accurate diagnosis of suspected EPTB.
Bacterial Proteins ; genetics ; metabolism ; China ; DNA-Directed RNA Polymerases ; genetics ; metabolism ; Diagnostic Tests, Routine ; instrumentation ; methods ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; metabolism ; Retrospective Studies ; Rifampin ; pharmacology ; Sensitivity and Specificity ; Sputum ; Tuberculosis ; Tuberculosis, Pulmonary ; diagnosis ; microbiology

In order to evaluate the performance of a molecular Hain line probe assay (Hain LPA) for rapid detection of rifampicin and isoniazid resistance of Mycobacterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing (DST). The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.
China ; Genotyping Techniques ; methods ; Humans ; Isoniazid ; pharmacology ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Rifampin ; pharmacology ; Tuberculosis, Multidrug-Resistant ; diagnosis ; microbiology

OBJECTIVETo induce Mycobacterium tuberculosis (MTB) resistance with ofloxacin (Ofx) of stepwise increasing concentration in vitro, investigate stability to fluoroquinolone (FQs) antibiotic of MTB, and analyze the molecular mechanism and mutation specialty of drug resistance preliminarily.

METHODSMTB Standard strain H37RV and 24 clinical isolates susceptible to Ofx were selected and experimentally serially subcultured in liquid culture medium containing increasing concentration of Ofx and induced the drug resistance to Ofx. Variety of Minimal Inhibitory Concentrations (MICs) to FQs drugs were detected by microwell-MIC-test method. Mutations of quinolone resistance determining region (QRDR) of gyrA gene were sequenced and identified. Relationship of different mutation sites and drug resistant degree were analyzed. A total of 6 MTB clinical isolates resistant to Ofx and induced drug resistant isolates in vitro were serially subcultured in liquid culture medium without drug. Variety of drug resistant stability, including MIC and mutation of gyrA gene were detected.

RESULTSMIC values of 21 Ofx susceptible isolates after induction were eight times higher than before, which were induced to drug resistant strains successfully and also resistant to Lfx and Mfx. Hot mutations of QRDR of gyrA gene were detected by sequencing, except one strain. Mutation of codon 94 occurred in 60% (12/20) of the strains with mutations and corresponding value of 50% Minimal Inhibitory Concentrations(MIC50) was ≥ 8 µg/ml. In all, 4 of 6 MTB clinical isolates resistant to Ofx harbored mutation of codon 90 (67%) , but the corresponding value of MIC50 was 2 µg/ml. After 21 serially subcultured in liquid culture medium without drug, MIC values of 6 clinical isolates resistant to Ofx were not changed obviously and mutations were also not changed. After 11 times serially subcultured in culture medium without drug, MIC values of induced drug resistant strains were also not changed obviously, but new mutations were detected in QRDR of 3 isolates.

CONCLUSIONMTB strains resistant to three kinds of FQs antibiotic were obtained by induction in vitro with Ofx. Codons 88, 94 mutations of QRDR of gyrA gene were related to the high level FQs drug resistance of MTB. Drug resistant stability of MTB to FQs was strong, and it is difficult for MTB to resume susceptibility.

Antitubercular Agents ; pharmacology ; DNA Gyrase ; genetics ; Drug Resistance, Bacterial ; genetics ; Microbial Sensitivity Tests ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Ofloxacin ; pharmacology

Tuberculous liver abscesses are rare. Paradoxical response in tuberculosis is common and occurred between 2 weeks and 12 weeks after anti-tuberculous medication. We report here a case of tuberculous liver abscess that developed in a paradoxical response during chemotherapy for tuberculous peritonitis in a 23-year-old male. He was hospitalized, complaining of ascites, epigastric pain. He was diagnosed tuberculous peritonitis by expiratory laparoscopic biopsy and took medication for tuberculosis. After 2 months, a hepatic lesion was detected with CT scan incidentally. Chronic granulomatous inflammation was seen in ultrasound-guided liver biopsy, and tuberculous liver abscess was diasnosed. It was considered as paradoxical response, rather than treatment failure or other else because clinical symptoms of peritoneal tuberculosis and CT scan improved. After continuing initial anti-tuberculous medication, he was successfully treated. Herein, we report a case of tuberculous liver abscess as paradoxical response while treating peritoneal tuberculosis without changing anti-tuberculous treatment regimen.
Antitubercular Agents/*adverse effects/*therapeutic use ; DNA, Bacterial/analysis ; Humans ; Laparoscopy ; Liver/pathology/ultrasonography ; Liver Abscess/*chemically induced/*diagnosis/microbiology ; Male ; Mycobacterium tuberculosis/genetics/isolation & purification ; Necrosis/pathology ; Peritoneum/pathology ; Peritonitis, Tuberculous/*drug therapy ; Tomography, X-Ray Computed ; Tuberculosis/*diagnosis/microbiology ; Young Adult

A slowly growing, non-chromogenic mycobacterial strain was isolated from sputum and bronchial lavage fluid samples of a patient presenting with productive cough, blood-tinged sputum, low-grade fever, and weakness. A positive acid-fast bacilli sputum smear result prompted the initiation of an anti-tuberculosis regimen. Multiplex real-time PCR showed a negative result for Mycobacterium tuberculosis complex and a positive result for nontuberculous mycobacteria. The DNA chip test confirmed this organism as a member of the genus Mycobacterium, but could not specify the species. Interestingly, the mycolic acid patterns obtained by HPLC nearly overlapped with those of M. simulans. The sequences of the Mycobacterium 16S rRNA gene and 16S-23S internal transcribed spacer region were unique and were found to have 100% similarity with those of M. riyadhense. After a review of the literature, we report this case as the first Korean case of M. riyadhense lung infection.
Adult ; Antitubercular Agents/pharmacology ; Chromatography, High Pressure Liquid ; Female ; Humans ; Lung Diseases/*microbiology ; Microbial Sensitivity Tests ; Mycobacterium/classification/drug effects/*isolation & purification ; Mycobacterium Infections/microbiology ; Mycobacterium tuberculosis/genetics/isolation & purification ; Mycolic Acids/analysis ; Oligonucleotide Array Sequence Analysis ; Phylogeny ; RNA, Ribosomal, 16S/chemistry/genetics ; RNA, Ribosomal, 23S/chemistry/genetics ; Republic of Korea ; Sequence Analysis, DNA

OBJECTIVETo understand the characteristics of pncA gene in multidrug-resistant Mycobacterium tuberculosis isolates and its correlation with drug resistance to pyrazinamide.

METHODSA total of 127 clinical isolates of multidrug-resistant mycobacterium tuberculosis were collected from Shenzhen from year 2007 to 2009. PZA susceptibility was determined by the BACTEC MGIT 960 PZA method. Pyrazinamidase (PZase) activity testing and pncA gene sequencing were performed in all the isolates. The type and frequency of mutations in pncA were determined. Correlation analysis among PZA susceptibility and PZase activity, pncA mutation was performed.

RESULTSAmong the 127 isolates, 62 isolates (48.8%) were found resistance to PZA. Among the 62 PZA resistant isolates, 45 isolates which had various pncA mutations were negative for PZase. Mutation rate was 77.4% (48/62) in total PZA resistance isolates. Different types of 48 resistant isolates were identified in the pncA gene, including base substitution (33 isolates), frame shift mutation (12 isolates) and codon mutation (3 isolates). No mutations except one isolate (N11D) existed in all PZA-susceptibility isolates which were positive for PZase. A total of 5 mutations which have not been described previously were found as follows: H57P, P62Q, G108R, D110Y and G162V. The correlation among the PZA susceptibility and the PZase activity (r = 0.895, P < 0.05), the pncA mutation (r = 0.779, P < 0.05) were significant in 127 multidrug-resistant isolates.

CONCLUSIONA high diversity of pncA gene mutation was found among PZA resistant strains of MTB. This study revealed five new mutations of the pncA gene that were not previously described, which scattered in the hot-spot regions located in the metal coordination site and active site of the enzyme. Mutations had a high correlation with the PZA resistance.

Antitubercular Agents ; pharmacology ; DNA, Bacterial ; genetics ; Humans ; Mutation ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Pyrazinamide ; pharmacology ; Tuberculosis, Multidrug-Resistant ; genetics ; microbiology

OBJECTIVETo explore the correlation between Beijing genotype (Beijing family) strains of Mycobacterium tuberculosis (MTB) and drug resistance.

METHODSA computer retrieval of Medline, Embase, SCI, EBSCO, CNKI, Weipu and Wanfang databases from 1990 to 2010 was conducted. A total of 525 articles exploring the relationship of Beijing genotype of MTB and drug resistance were found through literature search. Following the inclusion and exclusion criteria, a Meta-subgroup analysis was conducted in Beijing genotype of MTB and drug resistance.

RESULTSA total of 38 articles were selected, including 22 articles on isoniazid resistance, 24 articles on rifampin resistance, 19 articles on ethambutol resistance, 18 articles on ethambutol resistance, 26 articles on multi-drug resistance (MDR). Meta-subgroup analysis showed that in China, there was an association between Beijing genotype and resistance to rifampin, ethambutol and MDR: rifampin (OR = 1.62, 95%CI: 1.13 - 2.31), ethambutol (OR = 1.67, 95%CI: 1.16 - 2.40), MDR (OR = 1.79, 95%CI: 1.20 - 2.68); in Russia, there was an association between Beijing genotype and resistance to isoniazid, rifampin, ethambutol and MDR: isoniazid (OR = 4.82, 95%CI: 3.19 - 7.29), rifampin (OR = 4.84, 95%CI: 3.84 - 6.10), ethambutol (OR = 3.32, 95%CI: 2.51 - 4.40), MDR (OR = 5.42, 95%CI: 3.36 - 8.74); in Vietnam, there was an association between Beijing genotype and resistance to isoniazid, rifampin, ethambutol and MDR: isoniazid (OR = 2.12, 95%CI: 1.55 - 2.91), rifampin (OR = 4.71, 95%CI: 3.01 - 7.36), ethambutol (OR = 3.78, 95%CI: 1.63 - 8.77), MDR (OR = 4.21, 95%CI: 1.58 - 11.18); in other countries, there was an association between Beijing genotype and resistance to isoniazid, rifampin, ethambutol and MDR: isoniazid (OR = 1.69, 95%CI: 1.19 - 2.42), rifampin (OR = 2.48, 95%CI: 1.92 - 3.19), ethambutol (OR = 3.04, 95%CI: 2.13 - 4.33), MDR (OR = 2.36, 95%CI: 1.52 - 3.68).

CONCLUSIONBeijing genotype of MTB was positively associated with three kinds of first-line anti-tuberculosis drugs (isoniazid, rifampin, ethambutol) and MDR, and the relationship intensity was different in different countries.

Antitubercular Agents ; pharmacology ; China ; DNA, Bacterial ; Drug Resistance, Multiple, Bacterial ; Genotype ; Humans ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Russia ; Tuberculosis, Multidrug-Resistant ; genetics ; microbiology ; Vietnam

OBJECTIVETo study the characteristics of drug-resistant genetic mutation of rpoB in multiple drugs resistant bacillus tuberculosis (MDR-TB) among patients of pneumoconiosis complicated with pulmonary tuberculosis.

METHODSA total of 114 clinical isolated strains of Mycobacterium tuberculosis were collected, MDR-TB were identified by conventional antimicrobial susceptibility test (AST). Their genomes DNA were extracted, the target genes were amplified by PCR, and the hot regions in the rpoB gene were analyzed by automated DNA sequenator.

RESULTSThe results by AST showed that there were 31 strains of MDR-TB in the 114 clinical isolated strains, the rate of drug resistance was 27.19% (31/114). No mutation of rpoB was identified in 10 rifampicin-sensitive strains that randomly chosen, while conformation changes were found in MDR-TB strains, and the mutation rate of rpoB was 93.55% (29/31) in resistant strains, mainly concentrated in codon 531 (45.16%, 14/31) and 526 (29.03%, 9/31), happened base substitutions, including 27 unit point mutation and 2 two point mutation.

CONCLUSIONSThe substitution of highly conserved amino acids encoded by rpoB gene results in the molecular mechanism responsible for RFP resistance in MDR-TB among patients of pneumoconiosis complicated with pulmonary tuberculosis. It also proves that rpoB gene is diversiform.

Adult ; Aged ; Bacterial Proteins ; genetics ; DNA-Directed RNA Polymerases ; Drug Resistance, Multiple, Bacterial ; genetics ; Genes, Bacterial ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Mining ; Mutation Rate ; Mycobacterium tuberculosis ; drug effects ; genetics ; isolation & purification ; Pneumoconiosis ; microbiology ; Sequence Analysis ; Tuberculosis, Pulmonary ; microbiology

LysinB (LysB) in mycobacteriophage D29 was cloned and expressed and its enzymatic properties were analysed. The lysB gene was amplified by PCR from mycobacteriophage D29 genomic DNA and inserted into pET22b vector. The constructed recombinant plasmid was transformed into Escherichia coli BL21(DE3) to express fusion protein, which was purified by Ni-NTA column and enzymatic activity detected. The results showed that expression plasmid pET22b-lysB was constructed successfully. Highly purified recombination protein (His-LysB) was obtained 33.2 mg from 1 L LB culture medium. A screening for His-LysB activity on esterase and lipase substrates confirmed the lipolytic activity. With p-nitrophenyl butyrate as substrate, the thermal stability of the enzyme was poor when the temperature was above 30 degrees C. The enzyme exhibited higher stability at pH 5.0-9.5. The optimum temperature and pH for the lipolytic activity of His-LysB were 23 degrees C and 7.5 respectively. Under the optimum conditions, the specific activity of His-LysB was 1.3 U/mg. Zn2+, CU2+, Mg2+, Mn2+ and phenylmethane sulfonyl fruoride severely inhibited the lipolytic activity of His-LysB. The result provides a new option for tuberculosis drug research and development.
Cloning, Molecular ; Enzyme Stability ; Escherichia coli ; genetics ; metabolism ; Mycobacteriophages ; enzymology ; Mycobacterium tuberculosis ; drug effects ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification ; metabolism ; Viral Proteins ; biosynthesis ; genetics