A significant knowledge gap exists concerning the geographical distribution of nontuberculous mycobacteria (NTM) isolation worldwide.To provide a snapshot of NTM species distribution, global partners in the NTM-Network European Trials Group (NET) framework (www.ntm-net.org), a branch of the Tuberculosis Network European Trials Group (TB-NET), provided identification results of the total number of patients in 2008 in whom NTM were isolated from pulmonary samples. From these data, we visualised the relative distribution of the different NTM found per continent and per country.We received species identification data for 20 182 patients, from 62 laboratories in 30 countries across six continents. 91 different NTM species were isolated. Mycobacterium avium complex (MAC) bacteria predominated in most countries, followed by M. gordonae and M. xenopi. Important differences in geographical distribution of MAC species as well as M. xenopi, M. kansasii and rapid-growing mycobacteria were observed.This snapshot demonstrates that the species distribution among NTM isolates from pulmonary specimens in the year 2008 differed by continent and differed by country within these continents. These differences in species distribution may partly determine the frequency and manifestations of pulmonary NTM disease in each geographical location. @ERSpublications Species distribution among nontuberculous mycobacteria isolates from pulmonary specimens is geographically diverse
Two regions of rpoB associated with rifampin resistance were sequenced in 29 rifampin-resistant (determined by the proportion method) isolates of Mycobacterium tuberculosis obtained from patients from three counties in Hungary. Of the 29 resistant strains, 27 had a mutation in either the 81-bp region (26 strains) or the N-terminal region (1 strain), while the other 2 strains had no mutations in either region. The locations and frequencies of the mutations differed from those previously reported. The most common mutation in this study, D516V, was found in 38% of the Hungarian strains, a frequency 2 to 10 times higher than that found in studies from other countries. These same 29 isolates were also evaluated with the Inno-LiPA Rif. TB test (LiPA), a reverse hybridization assay for the rapid detection of rifampin resistance. Although LiPA detected the presence of an rpoB mutation in 26 of the resistant isolates, the type of mutation could not be determined in 4 isolates because the mutations present were not among those included on the LiPA strip. In addition, a silent mutation in one of the rifampin-susceptible control strains was interpreted as rifampin resistant by LiPA. These findings demonstrate the importance of validating this rapid molecular test by comparison with DNA sequence results in each geographic location before incorporating the test into routine diagnostic work.The recent worldwide increase in the incidence of drugresistant strains of Mycobacterium tuberculosis has highlighted the need for faster and more accurate detection of resistance to rifampin (RMP), one of the most important antituberculosis drugs (17). RMP is most effective in killing actively metabolizing M. tuberculosis, and resistance to RMP often results in high clinical relapse rates (5, 15). Because of the prolonged turnaround time for conventional susceptibility testing, patients infected with drug-resistant tuberculosis may be inadequately treated and thus remain infectious for longer periods than those infected with susceptible strains.Based on collective observations that mutations resulting in an amino acid change within the 81-bp core region of the RNA polymerase -subunit (rpoB) gene are found in more than 96% of RMP-resistant M. tuberculosis strains, several molecular methods have been developed for the rapid (24-to 48-h) detection of mutations in this region (3,10,16,18,24,25,(28)(29)(30). In addition, other studies revealed that mutations associated with RMP resistance can also occur in other regions of the rpoB gene, although less frequently (6,7,23). It has also been shown elsewhere that the information provided by these molecular tests can serve as a molecular epidemiological marker since the relative frequency of the alleles associated with resistance can vary geographically (10,20).Therefore, the aim of the present study was to determine the drug resistance profile of 29 RMP-resistant M. tuberculosis isolates obtained in East Hungary and to detect and identify mutations present in the rpoB gene. Two molecular assays we...
Data regarding the epidemiology of callosal anomalies are contradictory. We performed a population-based retrospective survey to study the birth prevalence and clinical features of agenesis/hypoplasia of the corpus callosum and accompanying central nervous system and somatic abnormalities in southeastern Hungary between July 1, 1992 and June 30, 2006. Among 185,486 live births, 38 patients (26 boys and 12 girls) manifested agenesis/hypoplasia of the corpus callosum, corresponding to a prevalence of 2.05 per 10,000 live births (95% confidence interval, 1.4-2.7). Callosal anomalies were isolated in 18 patients, and were associated with other central nervous system malformations in five children. Both central nervous system and noncentral nervous system abnormalities were evident in seven patients, whereas callosal dysgenesis was accompanied only by somatic anomalies in eight children. Five of 18 patients with isolated agenesis/hypoplasia of the corpus callosum remained asymptomatic. Developmental delay, intellectual disability, or epilepsy occurred in all patients, except one, when callosal anomalies were combined with other brain or somatic abnormalities. Five patients with multiplex malformations died. Callosal anomalies form a clinically significant and relatively frequent group of central nervous system malformations.
Mycobacterium tuberculosis is a successful pathogen, and it can survive in infected macrophages in dormant phase for years and decades. The therapy of tuberculosis takes at least six months, and the slow-growing bacterium is resistant to many antibiotics. The development of novel antimicrobials to counter the emergence of bacteria resistant to current therapies is urgently needed. In silico docking methods and structure-based drug design are useful bioinformatics tools for identifying new agents. A docking experiment to M. tuberculosis dUTPase enzyme, which plays a key role in the bacterial metabolism, has resulted in 10 new antitubercular drug candidates. The uptake of antituberculars by infected macrophages is limited by extracellular diffusion. The optimization of the cellular uptake by drug delivery systems can decrease the used dosages and the length of the therapy, and it can also enhance the bioavailability of the drug molecule. In this study, improved in vitro efficacy was achieved by attaching the TB5 antitubercular drug candidate to peptide carriers. As drug delivery components, (i) an antimicrobial granulysin peptide and (ii) a receptor specific tuftsin peptide were used. An efficient synthetic approach was developed to conjugate the in silico identified TB5 coumarone derivative to the carrier peptides. The compounds were effective on M. tuberculosis H37Rv culture in vitro; the chemical linkage did not affect the antimycobacterial activity. Here, we show that the OT20 tuftsin and GranF2 granulysin peptide conjugates have dramatically enhanced uptake into human MonoMac6 cells. The TB5-OT20 tuftsin conjugate exhibited significant antimycobacterial activity on M. tuberculosis H37Rv infected MonoMac6 cells and inhibited intracellular bacteria.
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