The GeneXpert MTB/RIF assay was evaluated with microscopically negative and positive pulmonary and extrapulmonary specimens from patients with substantial clinical indications for tuberculosis. For the pulmonary samples, the sensitivity, specificity, and positive and negative predictive values were 90.6%, 94.3%, 93.5%, and 91.7%, and for the extrapulmonary samples, they were 100%, 91.6%, 50%, and 100%, respectively. For microscopically negative specimens, the respective values were 86.3%, 93%, 79%, and 95.6%. The assay correctly detected rifampin resistance in all but one specimen, which harbored a mixed population. The GeneXpert assay was highly effective for tuberculosis diagnosis and identification of rifampin-resistant strains in smear-negative samples.Tuberculosis (TB) remains a major public health problem, accounting for more than 9.4 million incident cases and 1.3 million deaths every year, worldwide (10). The emergence and spread of multidrug (MDR) and extensively (XDR) drug-resistant Mycobacterium tuberculosis complex (MTBC) strains poses significant challenges to disease control (11). In order to overcome conventional methods' low sensitivity and diagnostic delays, nucleic acid amplification (NAA) tests have been introduced. The NAA tests' sensitivities are high for specimens that are acid-fast bacillus (AFB) microscopy positive but lower for AFB-negative specimens (3). The identification of mutations associated with drug resistance depends on additional NAA tests, whose application on clinical samples is indicated only for AFB-positive specimens.The recently introduced Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA) detects the presence of MTBC DNA and its susceptibility to rifampin (RMP) in a single reaction (4,8). Monoresistance to RMP is rare; however, Ͼ90% of RMPresistant isolates also exhibit resistance to isoniazid (INH). Therefore, the detection of RMP resistance may serve as a surrogate marker for MDR M. tuberculosis (9). The assay is based on a heminested real-time PCR (RT-PCR) that targets the rpoB gene hot spot region. Any deviation from the wildtype sequence resulting in a delay in the appearance of the signal exceeding a predetermined ⌬C T value (Ͼ3.5), between the earliest and latest cycle threshold (C T ) values, is reported as RIF resistant. The test is carried out within 2 h in a disposable cartridge. The only manual step is the mixing of a bactericidal buffer with the sample prior to addition to the cartridge. This preamplification step reduces the viability of MTBC organisms, making the assay suitable for use near patients in settings with limited biocontainment facilities (1).A prospective study was conducted between September 2009 and May 2010 at the National Reference Laboratory for Mycobacteria (NRLM), Athens, Greece, in order to assess the performance of the Xpert MTB/RIF assay in AFB-negative respiratory and nonrespiratory specimens in a routine hospital laboratory setting. Specimens were selected from patients with strong clinical indications for TB. A small number of AFBpositiv...

The case of an elderly immunocompromised man with non-Hodgkin's lymphoma who presented with fever, abdominal pain and bloody diarrhea is described. Brachyspira pilosicoli was isolated from culture. The patient was treated with penicillin G i.v. and became afebrile. B. pilosicoli is a recently recognized enteric pathogen of humans and animals. Intestinal spirochetosis should be included in the differential diagnosis of any immunocompromised or critically ill patient with dysentery.

In our settings, active TB is decreasing among children of Greek origin; disease epidemiology and drug resistance is influenced by the increasing influx of immigrants from areas where the disease is highly prevalent.

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A prediction model based on the variables of purulent sputum, FEV(1) and BMI predicted sputum culture result with about 90% accuracy. Pending further validation, this model may save valuable healthcare resources.