The Cobas TaqMan MTB test, based on real-time PCR technology, was evaluated for direct detection of Mycobacterium tuberculosis complex (MTBC) in respiratory specimens. A total of 1,093 samples from 446 patients, including 118 acid-fast smear-positive and 975 acid-fast smear-negative specimens, were investigated. Diagnostic cultures performed with 7H11 agar, Löwenstein-Jensen medium, and the Bactec MGIT 960 system were considered the reference methods. When discrepant results between the Cobas TaqMan MTB test and culture occurred, additional results from the BD MGIT TBc identification test and the GenoType Mycobacterium CM test performed on growth-positive and acid-fast-stain-positive MGIT tubes and review of the patient's medical history were used for discrepancy analysis. The overall sensitivity, specificity, positive predictive value, and negative predictive value for the Cobas TaqMan MTB test were 91.5%, 98.7%, 91.5%, and 98.7%, respectively. In general, the performance of the new Cobas TaqMan MTB test was comparable to that of the replaced Cobas Amplicor MTB system. The most prominent feature of the new system was its extraordinarily high sensitivity (79.5%) for detecting MTBC in smear-negative specimens; out of 44 smear-negative but culture-positive specimens, 35 were positive by the new system. The Cobas TaqMan MTB assay, including DNA extraction, can be completed within 3 h. Tuberculosis (TB) is one of the most threatening curable infectious diseases. The disease afflicts approximately 8.6 million patients and causes about 2 million deaths annually (25). The increasing global burden of mycobacteriosis is associated with improper antibiotic therapy and immunocompromised patients, such as those with AIDS (1). Early diagnosis of TB and the prompt use of adequate antibiotics to interrupt transmission remain the top priorities for TB control (5).The conventional diagnosis of mycobacterial infections is based primarily on demonstration of the presence of acid-fast bacilli (AFB) in the smear, followed by a positive culture and identification of the isolate by biochemical characteristics. In the past decades, several commercial systems are gaining popularity for direct detection of Mycobacterium tuberculosis complex (MTBC) in clinical specimens, for instance, the Cobas Amplicor MTB test (Roche, Basel, Switzerland), the amplified M. tuberculosis direct test (Gen-Probe, San Diego, CA), the BDProbe Tec ET system (Becton, Dickinson and Company, Sparks, MD), and the GenXpert MTB/RIF system (Cepheid, Sunnyvale, CA). These systems, being able to reduce the diagnostic time from weeks to hours, have been acquiring great attention in TB diagnosis. In general, the specificity of these systems is very high while the sensitivity varied widely (16). For most commercial tests, the assay sensitivities (87.5% to 100%) seem to be satisfactory for AFB smear-positive specimens, but the sensitivities (50.0% to 70.8%) varied greatly for AFB smear-negative samples (16).The Cobas Amplicor MTB assay for direct detection of MTBC in pulmon...

The new cell culture method can be used to develop gastric epithelial cell clones with sustained growth from endoscopic biopsy. The gastric cell clone showed several stem and/or progenitor cell phenotypes (i.e. the ability of AIG, high differentiation capacity, high susceptibility to spontaneous immortalization and the expression of Oct-4). The telomerase expression in these gastric stem and/or progenitor cells can be upregulated by exposure to H. pylori culture products and MNNG, an important step in neoplastic transformation. These results show that putative human gastric stem and/or progenitor cell clones can be developed by our method and these cells could be useful for studying the mechanisms of human gastric carcinogenesis including the mechanism of action of H. pylori, as well as the regulation of the proliferation and differentiation of human gastric mucosa.

High-level amoxicillin resistance is associated with beta-lactamase production in H. pylori. Low-level amoxicillin resistance is linked to a point mutation on pbp1A. Because H. pylori can exchange DNA through natural transformation, spreading of bla(TEM-1) amoxicillin resistance gene among H. pylori is a potential threat when treating H. pylori infection.