Extrapulmonary tuberculosis (EPTB) accounts for more than 20% of tuberculosis (TB) cases. Xpert MTB/RIF (Xpert) (Cepheid, Sunnyvale, CA, USA) is a fully automated amplification system, for which excellent results in the diagnosis of pulmonary TB in highly endemic countries have been recently reported. We aimed to assess the performance of the Xpert system in diagnosing EPTB in a low incidence setting.We investigated with Xpert a large number of consecutive extrapulmonary clinical specimens (1,476, corresponding to 1,068 patients) including both paediatric (494) and adult samples.We found, in comparison with a reference standard consisting of combination of culture and clinical diagnosis of TB, an overall sensitivity and specificity of 81.3% and 99.8% for Xpert, while the sensitivity of microscopy was 48%. For biopsies, urines, pus and cerebrospinal fluids the sensitivity exceeded 85%, while it was slightly under 80% for gastric aspirates. It was, in contrast, lower than 50% for cavitary fluids. High sensitivity and specificity (86.9% and 99.7%, respectively) were also obtained for paediatric specimens.Although the role of culture remains central in the microbiological diagnosis of EPTB, the sensitivity of Xpert in rapidly diagnosing the disease makes it a much better choice compared to smear microscopy. The ability to rule out the disease still remains suboptimal.

Background Gram-negative bacteremia (GNB) is a major cause of illness and death after hematopoietic stem cell transplantation (HSCT), and updated epidemiological investigation is advisable. Methods We prospectively evaluated the epidemiology of pre-engraftment GNB in 1118 allogeneic HSCTs (allo-HSCTs) and 1625 autologous HSCTs (auto-HSCTs) among 54 transplant centers during 2014 (SIGNB-GITMO-AMCLI study). Using logistic regression methods. we identified risk factors for GNB and evaluated the impact of GNB on the 4-month overall-survival after transplant. Results The cumulative incidence of pre-engraftment GNB was 17.3% in allo-HSCT and 9% in auto-HSCT. Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most common isolates. By multivariate analysis, variables associated with GNB were a diagnosis of acute leukemia, a transplant from a HLA-mismatched donor and from cord blood, older age, and duration of severe neutropenia in allo-HSCT, and a diagnosis of lymphoma, older age, and no antibacterial prophylaxis in auto-HSCT. A pretransplant infection by a resistant pathogen was significantly associated with an increased risk of posttransplant infection by the same microorganism in allo-HSCT. Colonization by resistant gram-negative bacteria was significantly associated with an increased rate of infection by the same pathogen in both transplant procedures. GNB was independently associated with increased mortality at 4 months both in allo-HSCT (hazard ratio, 2.13; 95% confidence interval, 1.45–3.13; P <.001) and auto-HSCT (2.43; 1.22–4.84; P = .01). Conclusions Pre-engraftment GNB is an independent factor associated with increased mortality rate at 4 months after auto-HSCT and allo-HSCT. Previous infectious history and colonization monitoring represent major indicators of GNB. Clinical Trials registration NCT02088840.

Drug-resistant Mycobacterium tuberculosis strains are a real threat to tuberculosis (TB) control worldwide, as strains resistant to major anti-TB drugs have emerged. Multidrug-resistant TB (MDR-TB; resistant at least to rifampin and isoniazid) requires prolonged and expensive chemotherapy, with low cure and high fatality rates (8). In several Eastern European countries economic crisis and health system weaknesses have led to an increase in the numbers of TB cases, together with the establishment of hot spots for MDR-TB. Laboratory surveillance of drug resistance and early identification of resistant strains are critical steps for the beginning of appropriate treatment. Any delay in resistant strain identification jeopardizes the efforts to control the transmission of the disease.Rifampin (RIF) resistance is due to mutation in a relatively small fragment (81 bp) of the rpoB gene encoding for the ␤-subunit of the RNA polymerase (12, 29, 35); isoniazid (INH) resistance is caused by mutations in one of several regions of the katG gene, the inhA regulatory and coding region, and the ahpC-oxyR, ndh, and kasA genes (3,4,18,19,26,29,32,33,36,39). Analysis of strains collected in different countries shows different prevalences of the mutations (24).Easy-to-perform, rapid, and cost-effective assays based on molecular techniques that are suitable for application in clinical mycobacteriology laboratories are necessary to evaluate the presence of genomic mutations conferring resistance. Detection of resistance by conventional methods is inadequate due to the slow growth rate of M. tuberculosis; in addition, direct detection of known mutations could be more reliable in predicting the response to therapy.The Genotype MTBDR (Hain Lifescience, Nehren, Germany) is a new commercial and easy-to-perform assay developed for the detection of RIF and/or INH resistance in TB strains. The test is based on reverse hybridization between amplicons derived from a multiplex PCR and nitrocellulosebound wild-type and mutated probes for the mutations of interest.The aim of the present study was to evaluate Genotype MTBDR as a rapid diagnostic tool to detect rpoB and katG gene mutations that are associated with RIF and INH resistance, respectively, in TB isolates.We tested 206 M. tuberculosis strains isolated in Italy during the past 3 years, including 139 MDR strains and 30 fully susceptible ones. A total of 69 strains were collected from Italian patients, and 137 were obtained from foreign-born people. In order to show that the test is suitable for the direct detection on clinical specimens, we also performed the test on respiratory samples collected from active TB patients. (Table 1). A total of 85% of the MDR strains were isolated from retreatment cases. MATERIALS AND METHODS Strains

The aim of this study was to compare the performance of the T-SPOT.TB TM test, a Tcell-based test, with the tuberculin skin test (TST) in the diagnosis of latent tuberculosis (TB) infection.The study was carried out in 138 immunosuppressed haematology patients who had been nosocomially exposed to a case of smear-positive TB.Overall, 44.2% of the contacts were positive by T-SPOT.TB TM test, and 17.4% by TST (concordance 67.8%). The apparent prevalence of infection fell from 25.9 to 14.5% with the TST with increasing immunosuppression, although this difference was not significant. In contrast, the apparent prevalence of infection with the T-SPOT.TB TM test was unaffected at 44.6 and 44.3%, respectively. The T-SPOT.TB TM test had an overall indeterminate rate of 4.3%, and this was also unaffected by the level of immunosuppression. This study suggests that the T-SPOT.TB TM test maintains its sensitivity and performance in immunocompromised patients, identifying a large number of truly infected patients anergic to the tuberculin skin test.

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