AIMTo study a continuous, on-line and automatic monitoring method for dissolution of drugs.

METHODSA new fiber optical chemical sensor prepared by sol-gel immobilization of molecular probe was reported. Based on multiple quenching of flurescence, an instrument and software system was designed to on-line monitor the drug dissolution of rifampicin.

RESULTSThe concentration of rifampicin was linear with ln(F0/F) when concentration was in the range of 10-170 micrograms/mL-1. The relative coefficient was 0.9993. The procession of dissolution can be on-line monitored. Parameters were obtained directly from the dissolution curve. There is no distinctly difference when compared with the method of the Pharmacopoeia of People's Republic of China (P > 0.05).

CONCLUSIONThis procession analysis can reflect the real dissolution of drug and obtain the total information.

Antibiotics, Antitubercular ; administration & dosage ; chemistry ; Automatic Data Processing ; Capsules ; Rifampin ; administration & dosage ; chemistry ; Solubility

With the emergence of drug resistant tuberculosis, it is very urgent to find novel anti-tuberculosis drugs, especially novel anti-drug-resistant tuberculosis drugs. Because of the slow growth and the need to work in a biosafty environment of Mycobacterium tuberculosis, the development of evaluation of drug effect is severely impeded. In order to solve these issues, non-pathogenic fast-growing Mycobacterium smegmatis is introduced as test organism. The inhA is one of a target of isoniazid (INH) overexpression or mutation of this gene in Mycobacterium tuberculosis conferring resistant to INH. A recombinant plasmid bearing inhA was constructed and electroporated into Mycobacterium smegmatis, using shuttle expression vector pMV261. Transformants were induced to express a protein of inhA, identified by SDS-PAGE. Results show that Mycobacterium smegmatis containing inhA plasmids exhibited 100-fold or greater increased resistance to INH, but it conferred no increased resistance to others first-line anti-tuberculosis drugs. Resazurin microtiter assay plate testing of Mycobacterium smegmatis susceptibility to drugs is a rapid, simple, and inexpensive method and could decrease color background of drugs by detecting fluorescence. It will be benefit for high-throughout screening of drugs of anti-isoniazid-resistant Mycobacteria.
Anti-Bacterial Agents ; pharmacology ; Antibiotics, Antitubercular ; pharmacology ; Antitubercular Agents ; pharmacology ; Bacterial Proteins ; genetics ; metabolism ; Drug Resistance, Bacterial ; Electroporation ; Ethambutol ; pharmacology ; Isoniazid ; pharmacology ; Microbial Sensitivity Tests ; Mycobacterium smegmatis ; drug effects ; genetics ; metabolism ; Oxidoreductases ; genetics ; metabolism ; Plasmids ; Rifampin ; pharmacology ; Streptomycin ; pharmacology

Pseudomembranous colitis is known to develop with long-term antibiotic administration, but antitubercular agents are rarely reported as a cause of this disease. We experienced a case of pseudomembranous colitis associated with rifampin. The patient was twice admitted to our hospital for the management of frequent bloody, mucoid, jelly-like diarrhea and lower abdominal pain that developed after antituberculosis therapy that included rifampin. Sigmoidoscopic appearance of the rectum and sigmoid colon and mucosal biopsy were compatible with pseudomembranous colitis. The antitubercular agents were discontinued and metronidazole was administered orally. The patient's symptoms were resolved within several days. The antituberculosis therapy was changed to isoniazid, ethambutol and pyrazinamide after a second bout of colitis. The patient had no further recurrence of diarrhea and abdominal pain. We report here on a case of pseudomembranous colitis associated with rifampin.
Aged ; Aged, 80 and over ; Antibiotics, Antitubercular/*adverse effects ; Diarrhea/etiology ; Enterocolitis, Pseudomembranous/*chemically induced ; Humans ; Male ; Rifampin/*adverse effects ; Tuberculosis, Pulmonary/drug therapy

Pseudomembranous colitis is a dangerous but unusual side effect of antibiotics usage. We report a case of pseudomembranous colitis that developed in a 50-year-old female patient with diabetes mellitus during first line anti-tuberculous therapy including rifampicin. The patient was diagnosed with active pulmonary tuberculosis 70 days earlier. On admission, she suffered intermittent abdominal pain and watery diarrhea for 2 weeks. Colonoscopy revealed exudative, punctuate, raised plaques with skip areas or edematous hyperemic mucosa, and histopathologic findings were consistent with pseudomembranous colitis with typical volcano-like exudate. Symptoms improved on treatment with metronidazole. There was no recurrence after reinstitution of the anti-tuberculous agents excluding rifampicin. In patients with persistent diarrhea receiving anti-tuberculosis treatment, rifampicin associated pseudomembranous colitis should always be kept in mind.
Antibiotics, Antitubercular/*adverse effects ; English Abstract ; Enterocolitis, Pseudomembranous/*chemically induced/diagnosis/drug therapy ; Female ; Humans ; Middle Aged ; Rifampin/*adverse effects ; Tuberculosis, Pulmonary/drug therapy

We performed an in vitro cell culture experiment to ascertain whether rifampin exhibits bactericidal effects against Orientia tsutsugamushi, the causative agent of scrub typhus. ECV304 cells were infected with the Boryong or AFSC-4 strain of O. tsutsugamushi and then, the cultures were maintained in media with increasing concentrations of rifampin, azithromycin, doxycycline, or chloramphenicol for 4 days. On day 5, the media were replaced with fresh antibiotic-free medium and the cultures were maintained until day 28. On days 5, 13, and 28, immunofluorescence (IF) staining of O. tsutsugamushi was performed. IF staining on days 13 and 28 revealed increasing numbers of IF-positive foci in all cultures, even in cultures initially exposed to the highest concentration of rifampin (80 microg/mL), azithromycin (80 microg/mL), doxycycline (20 microg/mL), or chloramphenicol (100 microg/mL). The present study reveals that rifampin has no bactericidal effect against O. tsutsugamushi as observed for azithromycin, doxycycline, and chloramphenicol. A subpopulation of the bacteria that are not killed by high concentrations of the antibiotics may explain the persistence of O. tsutsugamushi in humans even after complete recovery from scrub typhus with antibiotic therapy.
Antibiotics, Antitubercular/*pharmacology ; Cell Line, Tumor ; Drug Resistance, Bacterial ; Fluorescent Antibody Technique ; Humans ; Orientia tsutsugamushi/*drug effects/growth & development/metabolism ; Rifampin/*pharmacology

BACKGROUND: Infection caused by nontuberculous mycobacteria (NTM) has been increasing. Awareness of this infection is crucial yet problematic. Delayed management may lead to destructive results. We empirically treated a series of patients with clinical suspicion of NTM infection prior to the identification of the pathogen. METHODS: A total of 12 patients who developed surgical site infections between January 2011 and February 2014 were reviewed. Patients with a skin and subcutaneous infection resistant to standard management over two weeks, and previous history of aesthetic procedures within three months were regarded as highly suspected of having an NTM infection. A variety of diagnostic modalities were examined simultaneously, along with starting empirical treatment including a combination of clarithromycin and moxifloxacin, and surgical debridement. RESULTS: All wounds healed completely within 4 weeks. The mean follow-up duration was 7.2 months, and none of the patients developed relapse. Specific NTM pathogens were identified in six patients. Eight patients showed caseating granuloma implying an NTM infection. One patient showed an uncommon Stenotrophomonas infection, which was successfully treated. Three patients had no evidence of a pathogen despite repeated microbial tests. Complications such as scarring, pigmentation, and disfigurement were common in all the patients. CONCLUSIONS: NTM should be considered in the differential diagnosis of an unusual skin and soft-tissue infection. We propose an empirical regimen of clarithromycin and moxifloxacin as an efficient treatment option for an NTM infection.
Antibiotics, Antitubercular ; Cicatrix ; Clarithromycin ; Debridement ; Diagnosis, Differential ; Early Diagnosis ; Follow-Up Studies ; Granuloma ; Humans ; Mycobacterium Infections, Nontuberculous ; Nontuberculous Mycobacteria* ; Pigmentation ; Recurrence ; Skin ; Stenotrophomonas ; Wounds and Injuries

BACKGROUNDThe Xpert MTB/RIF showed high sensitivity and specificity in previous studies carried out in different epidemiological and geographical settings and patient populations in high-burden tuberculosis (TB) countries. However, there were little data obtained by validation or demonstration study of the assay in China. In this study, the performance of Xpert MTB/RIF was investigated in two county-level laboratories in Hunan Province, China.

METHODSConsecutive patients with suspected pulmonary tuberculosis (PTB) and suspicion for multidrug-resistant tuberculosis (MDR-TB) were enrolled. For each patient suspected to have PTB, three sputum specimens (one spot sputum, one night sputum, and one morning sputum) were collected and each sputum was tested with smear microscopy, Löwenstein-Jensen (LJ) culture, and Xpert MTB/RIF test. For comparison across subgroups and testing methods, 95% confidence intervals were calculated. All analyses were done with SPSS 16.0, and P < 0.05 was regarded as significant.

RESULTSFor case detection, the sensitivity of Xpert MTB/RIF was 100% for smear- and culture-positive TB and 88.6% for smear-negative and culture-positive TB; the overall sensitivity was 94.5% for all culture-positive patients. The specificity was 99.8%. The sensitivity of Xpert MTB/RIF assay was 22.0% in clinical TB patients and the specificity reached 100.0% in the group of patients who are infected with nontuberculous mycobacteria. For the detection of rifampin resistance, the sensitivity of MTB/RIF RIF-resistance detection was 92.9%, and the specificity was 98.7%. Of the 26 Xpert MTB/RIF-positive and RIF-resistant patients confirmed by LJ proportion tests, 20 (76.9%) patients were infected by MDR-TB.

CONCLUSIONSThe Xpert MTB/RIF assay is a highly sensitive and specific method for diagnosis of TB and RIF resistance, which will enable it to have the potential to be used in county-level laboratories and lead to the reduction of the infectious pool and improvements in TB control in China. Further evaluations in county-level laboratories for implementing the assay are still required.

Adult ; Antibiotics, Antitubercular ; therapeutic use ; China ; Female ; Humans ; Male ; Middle Aged ; Rifampin ; therapeutic use ; Tuberculosis ; diagnosis ; drug therapy ; Tuberculosis, Multidrug-Resistant ; Tuberculosis, Pulmonary ; diagnosis ; drug therapy ; Young Adult

OBJECTIVE: To systematically review the diagnostic accuracy of Xpert^® Mycobacterium tuberculosis/rifampicin (Xpert^® MTB/RIF) for the detection of active tuberculosis (TB) and rifampicin-resistance TB in Chinese patients. METHODS: Four Chinese databases (SinoMed, CNKI, WanFang database, and VIP) and three English databases (PubMed, Embase, and The Cochrane Library) were searched from January 1, 2000 to September 15, 2017, to identify diagnostic tests about the accuracy of Xpert^® MTB/RIF in Chinese patients. Two investigators screened the articles and extracted the information independently, and then the quality of each included study was evaluated by Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2. Bivariate random-effects meta-analysis was conducted to pool the sensitivity and specificity. In addition, subgroup analyses were performed based on patient type (TB patient and TB suspected patient), sample type (sputum, bronchoalveolar lavage fluid and others). All statistical analyses were conducted with Stata version 13.0. RESULTS: A total of 47 articles were included in this systematic review. Most of them (38 articles) were in Chinese and only 9 articles were in English. All the articles were published during 2014 to 2017, and the sample size ranged from 31 to 3 151. Forty articles including 42 comparisons about TB were finally included with the pooled sensitivity of 0.94 (95%CI: 0.92, 0.95) and the pooled specificity of 0.87 (95%CI: 0.84, 0.91). Subgroup analysis showed that different patient and specimen types had no significant differences on sensitivity, but the specificity of sputum group was higher than that of bronchoalveolar lavage fluid. As for the detection of rifampicin-resistant TB, 33 articles (38 comparisons) were analyzed, the pooled sensitivity and specificity were 0.92 (95%CI: 0.89, 0.94) and 0.98 (95%CI: 0.97, 0.99) respectively. There were no significant differences between the patient and specimen in the subgroup analyses. The Deeks funnel plot showed a possible publication bias for detecting active tuberculosis (P=0.08) and no publication bias for rifampicin-resistant TB (P=0.24). The likelihood ratio scatter gram showed that in clinical applications, Xpert^® MTB/RIF had a good diagnostic ability for detecting active tuberculosis, and it had good clinical diagnostic value in detecting rifampicin-resistant TB. CONCLUSION Xpert^® MTB/RIF has good sensitivity and specificity in detecting TB and rifampicin-resistant TB in Chinese people. In particular, it has good clinical value in diagnosing rifampicin-resistance TB.
Antibiotics, Antitubercular/therapeutic use* ; China ; Diagnostic Tests, Routine ; Drug Resistance, Bacterial ; Humans ; Rifampin/pharmacology* ; Sensitivity and Specificity ; Tuberculosis/drug therapy* ; Tuberculosis, Multidrug-Resistant/drug therapy* ; Tuberculosis, Pulmonary/drug therapy*

BACKGROUND: Tuberculosis (TB) remains an important cause of morbidity and mortality throughout the world. The surge of TB has been accompanied by an increase in multi-drug-resistant tuberculosis (MDR-TB). In this study, we developed a denaturing HPLC (DHPLC) method for detecting rpoB gene mutation as a rifampin resistance based on sequence. METHODS: In this study, we used 99 mycobacterial isolates grown in Ogawa media. At first, we used a PCR method that can amplify the 235 bp and 136 bp rpoB DNAs of Mycobacterium tuberculosis complex (MTB) and Non-tuberculous mycobacteria (NTM). And then, PCR-restriction fragment length polymorphism (RFLP) of rpoB DNA (342 bp), which comprises the Rif(T) region, was used for the differential identification of Mycobacteria. Finally, we detected these amplicons by DHPLC, compared to PCR-RFLP results, and performed sequencing. RESULTS: Among 99 mycobacterial isolates, 80 (81%) were MTB and 19 (19%) were NTM. NTM were identified to 7 different species by DHPLC and PCR-RFLP. rpoB mutation was detected in 9 (11%) of the MTB specimens. These results were confirmed by using sequencing. CONCLUSIONS: DHPLC provided a rapid, simple, and automatable performance for detection of rifampin resistant Mycobacterium tuberculosis complex and would be helpful as a supplemental method in high-throughput clinical laboratories.
Antibiotics, Antitubercular/*pharmacology ; Bacterial Typing Techniques ; Chromatography, High Pressure Liquid/*methods ; DNA, Bacterial ; Drug Resistance, Bacterial/genetics ; Humans ; Mutation ; Mycobacterium tuberculosis/*drug effects/genetics/*isolation & purification ; Rifampin/*pharmacology ; Tuberculosis/*microbiology

No abstract available.
Antibiotics, Antitubercular/*adverse effects ; Female ; Humans ; Kidney Transplantation/*adverse effects ; Middle Aged ; Neutropenia/blood/*chemically induced/diagnosis ; Opportunistic Infections/microbiology/*prevention & control ; Recurrence ; Rifabutin/*adverse effects ; Severity of Illness Index ; Time Factors ; Tuberculosis/microbiology/*prevention & control