[Multidrug-resistant tuberculosis]

High-dose gatifloxacin-based shorter treatment regimens for MDR/RR-TB

SETTING

The shorter treatment regimen (STR) for multidrug- or rifampicin-resistant tuberculosis (MDR/RR-TB) has achieved successful outcomes in many countries. However, there are few studies on high-dose gatifloxacin-based STR with adverse drug reactions (ADRs) and management.

DESIGN

A prospective observational study was conducted with MDR/RR-TB patients who were treated with a standardized 9 or 12 - month regimen: including gatifloxacin (Gfx), clofazimine (Cfz), ethambutol (EMB), and pyrazinamide (PZA), and supplemented by amikacin (Am), isoniazid (INH), and prothionamide (Pto) during an intensive phase of 4 or 6 - month. Monitored ADRs monthly until treatment completion and then followed up every three months for one year.

RESULTS

Among the 42 eligible patients, 35 (83.3%) completed treatment successfully, 1 (2.4%) lost to follow-up (LTFU), and 6 (14.3%) failed due to ADRs, with no death. The most important ADR was drug-induced liver damage, which occurred in 24 out of 42 (57.1%) patients and resulted in 4 (9.5%) failed treatments and 4 (9.5%) adjusted treatments. QT interval prolongation occurred in 17 out of 42 (40.5%) patients, 9 (21.4%) of them with the corrected QT interval according to Fridericia (QTcF) > 500 ms resulting in 7 (16.7%) adjusted treatments.

CONCLUSIONS

This study confirmed the effectiveness of the high-dose gatifloxacin-based STR but severe ADRs, especially hepatotoxicity and QT interval prolongation should never be ignored.

Adverse drug reaction prevalence and mechanisms of action of first-line anti-tubercular drugs

PURPOSE

Understanding the appearance of anti-tubercular drug-related adverse drug reactions (ADRs) in patients receiving tuberculosis (TB) treatment is important, and may be related to morbidity and mortality if not recognized early. Here, we aimed to characterize the mechanisms underlying adverse drug reactions due to combination anti-tuberculosis therapy of the Revised National Tuberculosis Control Program (RNTCP).

METHODS

This was a prospective observational study conducted in 9 DOTS centers of New Delhi, India. All enrolled TB patients receiving first-line tuberculosis treatment as per RNTCP guidelines were monitored for ADRs. All ADRs that appeared during the treatment were recorded and analyzed.

RESULTS

The study included 1011 TB patients on anti-TB treatment under DOTS. According to Naranjo's probability scale, of a total 351 (34.72%) reported adverse events, 102 (10.09%) were definite, 59 (5.83%) probable, 123 (12.17%) possible, and 67 (6.63%) doubtful. On the Hartwig severity scale, of the 351 adverse drug events, 225 (22.26%) were mild, 105 (10.38%) were moderate, and 21 (2.08%) were severe. Out of 102 reported adverse drug reactions, 81 (79.41%) were moderate and 21 (20.59%), while 65.28% did not experience any ADRs.

CONCLUSIONS

Directly Observed Treatment (DOT) is effective and safe compared to daily treatment regimens. Patients receiving DOTS therapy needed close monitoring for adverse events. Therefore, a pharmacovigilance program should be added at the National level to accesses the adverse event incidence.

Recent Synthetic Approaches and Biological Evaluations of Amino Hexahydroquinolines and Their Spirocyclic Structures

In this review, the recent synthetic approaches of amino hexahydroquinolines and their spirocyclic structures were highlighted. The synthetic routes include, two-components, three-components or fourcomponents reactions. The two-component [3+3] atom combination reaction represents the simplest method. It involves Michael addition of the electron rich β-carbon of β-enaminones to the activated double bond of cinnamonitriles followed by cyclization to yield hexahydroquinoline compounds. The bioactivity profiles and SAR studies of these compounds were also reviewed with emphasis to the utility of these substances as antimicrobial, anticancer and antitubercular agents, as well as calcium channel modulators.

Performance of a real-time PCR assay for the rapid identification of Mycobacterium species

Mycobacteria cause a variety of illnesses that differ in severity and public health implications. The differentiation of Mycobacterium tuberculosis (MTB) from nontuberculous mycobacteria (NTM) is of primary importance for infection control and choice of antimicrobial therapy. The diagnosis of diseases caused by NTM is difficult because NTM species are prevalent in the environment and because they have fastidious properties. In the present study, we evaluated 279 clinical isolates grown in liquid culture provided by The Catholic University of Korea, St. Vincent's Hospital using real-time PCR based on mycobacterial rpoB gene sequences. The positive rate of real-time PCR assay accurately discriminated 100% (195/195) and 100% (84/84) between MTB and NTM species. Comparison of isolates identified using the MolecuTech REBA Myco-ID(®) and Real Myco-ID® were completely concordant except for two samples. Two cases that were identified as mixed infection (M. intracellulare-M. massiliense and M. avium-M. massiliense co-infection) by PCRREBA assay were only detected using M. abscessus-specific probes by Real Myco-ID(®). Among a total of 84 cases, the most frequently identified NTM species were M. intracellulare (n=38, 45.2%), M. avium (n=18, 23.7%), M. massiliense (n=10, 13.2%), M. fortuitum (n=5, 6%), M. abscessus (n=3, 3.9%), M. gordonae (n=3, 3.9%), M. kansasii (n=2, 2.4%), M. mucogenicum (n=2, 2.4%), and M. chelonae (n= 1, 1.2%). Real Myco-ID(®) is an efficient tool for the rapid detection of NTM species as well as MTB and sensitive and specific and comparable to conventional methods.

Diagnosis of latent tuberculosis in patients with systemic lupus erythematosus: T.SPOT.TB versus tuberculin skin test

Early studies in patients with systemic lupus erythematosus (SLE) reported increased incidence of tuberculosis. The tuberculin skin test (TST) is the technique of choice to detect latent tuberculosis infection (LTBI) but has several limitations. Objectives. We compared TST and the newer T.SPOT.TB test to diagnose LTBI in SLE patients. Methods. In this observational cohort study conducted between August 2009 and February 2012, we recruited 92 patients from those attending the SLE clinic of our university hospital. Data recorded were epidemiological and sociodemographic characteristics. Laboratory analyses included TST and T.SPOT.TB tests. Results. Of the patients studied, 92% were women with an average age of 42.7 years. Overall, the degree of correlation between the two tests was low (Kappa index = 0.324) but was better in patients not receiving corticosteroids (CTC)/immunosuppressive (IS) therapy (Kappa = 0.436) and in those receiving hydroxychloroquine (Kappa = 0.473). While TST results were adversely affected by those receiving CTC and/or IS drugs (P = 0.021), the T.SPOT.TB results were not. Conclusion. Although the TST test remains a useful tool for diagnosing LTBI in SLE patients, the T.SPOT.TB test is perhaps better employed when the patient is receiving CTC and/or IS drugs.

Antitubercular effect of 8-[(4-Chloro phenyl) sulfonyl]-7-Hydroxy-4-Methyl-2H-chromen-2-One in guinea pigs

OBJECTIVE

TO EVALUATE THE ANTITUBERCULAR EFFICACY AND SAFETY OF NEW CHEMICAL ENTITY (NCE): 8-[(4-Chloro phenyl) sulfonyl]-7-Hydroxy-4-Methyl-2H-chromen-2-One (CSHMC) in guinea pigs.

MATERIALS AND METHODS

This pilot study was carried out in guinea pigs. They were infected with M. tuberculosis H(37)Rv (1.5 × 10(4) cfu/guinea pig) via intramuscular route. After 30 days, infections were confirmed in 6 guinea pigs by histopathology of spleen, lung, and liver. After that CSHMC (5 and 20 mg/kg) was administered for 1 month and its effect was compared with vehicle, rifampicin (60 mg/kg) and isoniazid (30 mg/kg). Efficacy of CSHMC was evaluated on the basis of histopathologic scoring of lesion in lung, spleen, liver, and safety on the basis of measuring hemogram, liver and renal function parameters.

RESULTS

Isoniazid, rifampicin, and CSHMC (20 mg/kg) significantly reduce the median lesion score in lung, spleen, and liver as compared to disease control group. Reduction in median lesion score for lung and spleen were not statistically significant for CSHMC 5 mg/kg. CSHMC (20 and 5 mg/kg) did not produce any changes in hemogram, liver and renal function parameters with respect to normal values.

CONCLUSIONS

CSHMC had shown significant antitubercular efficacy comparable to isoniazid and rifampicin and did not show hematological, hepato- and nephrotoxicity.

Molecular analysis of porin gene transcription in heterogenotypic multidrug-resistant Escherichia coli isolates from scouring calves

BACKGROUND

Despite evidence that altered membrane porins may impair microbial drug uptake thereby potentially compounding efflux pump-mediated multidrug resistance, few studies have evaluated gene transcription to identify multidrug-resistance-associated porins and other potential drug targets.

METHODS

Genes that encode six membrane porins (fadL, lamB, ompC, ompF, ompW and yiaT) and two membrane proteins (tolC and ompT) were assessed by PCR and by quantitative real-time PCR (qRT-PCR) analysis of 10 multidrug-resistant (MDR) and 10 antibiotic-susceptible (AS) Escherichia coli isolates. The mean DeltaDeltaCt values for the study E. coli genes were analysed by the Wilcoxon test (P = 0.05).

RESULTS

All 20 E. coli isolates tested positive for tolC, lamB, ompC, ompF genes, while 10 MDR and 9/10 (90%) AS isolates were positive for the fadL gene. Seven out of 10 (70%) MDR and 7/10 (70%) AS isolates were positive for the yiaT gene, while 7/10 (70%) MDR and only 4/10 (40%) AS isolates were positive for the ompT gene. The mean DeltaDeltaCt values for the tolC and yiaT genes were significantly higher in MDR than in AS isolates (Wilcoxon test; P < 0.05). No significant difference was seen with respect to fadL, lamB, ompC, ompF, ompT and ompW gene transcription (Wilcoxon test; P > 0.05).

CONCLUSIONS

Findings suggest up-regulated transcription of tolC and yiaT genes in the MDR E. coli isolates. These results indirectly suggest that TolC and YiaT proteins may play some role(s) in multidrug resistance, but proteomic studies are needed before the two proteins are considered potential drug targets.

[Diagnosis of tuberculosis in pediatrics. Consensus document of the Spanish Society of Pediatric Infectology (SEIP) and the Spanish Society of Pediatric Pneumology (SENP)]

Tuberculosis is one of the most important health problems worldwide. There are an increased number of cases, including children, due to different reasons in developed countries. The most likely determining cause is immigration coming from high endemic areas. Measures to optimize early and appropriate diagnosis of the different forms of tuberculosis in children are a real priority. Two Societies of the Spanish Pediatric Association (Spanish Society of Pediatric Infectology and Spanish Society of Pediatric Pneumology) have agreed this Consensus Document in order to homogenize diagnostic criteria in pediatric patients.

[Tuberculosis-related hospitalization in Spain: a cost analysis]

OBJECTIVE

To evaluate the number and cost of hospitalizations due to tuberculosis occurring in the Spanish National Health System (NHS) during 1999 to 2006.

METHODS

The specific diagnosis-related groups (DRG) for tuberculosis (DRGs 705, 709, 711 and 798-802) were analyzed.

RESULTS

We observed a striking decrease in hospitalizations (-25%), concomitant tuberculosis-HIV infection (-8.7%), and tuberculosis-related deaths (-0.5%, NS). In addition, there was a drop in the absolute number of hospital admissions and overall cost (from 31.3 to 30.8 and from 40.6 to 40.1 million euro), and a significant decrease in the relative hospitalizations and cost with respect to the overall number and hospital budget (from 0.21% to 0.10% and from 0.15% to 0.07%).

CONCLUSIONS

There is a marked decrease in tuberculosis-related hospitalizations and mortality, but the disease remains a considerable health burden.