Treating Primary Arthroprosthesis Infection Caused by subsp. a.

Prosthetic joint infections (PJI) caused by nontuberculous mycobacteria are very rare, and results of treatment can be unpredictable. A 72-year-old female underwent hip replacement after an accidental fall in a local hospital in Santo Domingo. The postoperative period was uneventful except for a traumatic wound near the surgical scar.

Comparative evaluation of Xpert MTB/RIF and the new Xpert MTB/RIF ultra with respiratory and extra-pulmonary specimens for tuberculosis case detection in a low incidence setting.

Background: The Xpert MTB/RIF assay (Xpert) is an automated molecular test for the detection of tuberculosis and rifampin resistance (RIF-R), but it lacks sensitivity in smear-negative samples and some limitations in determination of RIF-R have also been reported. The new Xpert MTB/RIF Ultra (Ultra) was developed to overcome these limitations. We aimed to compare Ultra and Xpert diagnostic accuracy setting culture and drug susceptibility testing as reference standards.

Revisiting problems and solutions to decrease Mycobacterium tuberculosis pyrazinamide false resistance when using the Bactec MGIT 960 system.

Pyrazinamide (PZA) is a first-line key drug used in combination with other agents for the treatment of tuberculosis (TB). Phenotypic and molecular assays for testing susceptibility of Mycobacterium tuberculosis (Mtb) to PZA have been developed, with the assay in liquid medium at acidic pH in the Bactec MGIT 960 (M960) system being routinely used in the mycobacteriology laboratories. However, false resistance to PZA by this method was reported to occur by several investigators, mostly due to high Mtb inoculum, which may impair drug activity by increasing the pH of the medium.

Pyrazinamide susceptibility testing: proposed new standard with the BACTECTM MGITTM 960 system.

The susceptibility of 253 Mycobacterium tuberculosis complex isolates to pyrazinamide (PZA) was assessed using the BACTECTM MGITTM 960 (M960) system. Resistant strains underwent paired repeat testing using 1) a critical concentration of 200 g/ml (PZA-200), and 2) a reduced inoculum of 0.25 ml.

Mycobacterial infections in solid organ transplant recipients.

Mycobacterial infections represent a growing challenge for solid organ transplant recipients (SOT). The adverse effects of tuberculosis (TB) therapy present a major difficulty, due to the interactions with immunosuppressive drugs and direct drug toxicity. While TB may be donor-transmitted or community-acquired, it usually develops at a latent infection site in the recipient.

The geographic diversity of nontuberculous mycobacteria isolated from pulmonary samples: an NTM-NET collaborative study.

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.

Prevention of false resistance results obtained in testing the susceptibility of Mycobacterium tuberculosis to pyrazinamide with the Bactec MGIT 960 system using a reduced inoculum.

The susceptibility of 211 clinical isolates of Mycobacterium tuberculosis complex (201 M. tuberculosis and 10 Mycobacterium bovis isolates) to pyrazinamide (PZA) was assessed by the nonradiometric Bactec MGIT 960 system (M960). Detection of PZA resistance was followed by a repeat testing using a reduced inoculum (RI) of 0.

Nontuberculous mycobacteria infection in solid organ transplant recipients.

Although advances in surgical technique, drug-induced immunosuppression, and supportive medical therapy have led to improved survival and quality of live after solid organ transplantations, infections still represent a major threat for transplant recipients.Infections with non tuberculous mycobacteria (NTM) are infrequent, but can be associated with relevant morbidity and mortality. With the exception of few comprehensive studies, the available literature consists predominantly of case reports and institutional experiences.

Performance of a commercial nucleic acid amplification test with extrapulmonary specimens for the diagnosis of tuberculosis.

The laboratory diagnosis of tuberculosis (TB) on extrapulmonary specimens is particularly challenging. A number of commercial nucleic acid amplification tests able to detect and identify Mycobacterium tuberculosis (MTB) complex directly from respiratory secretions have been developed, but their use on extrapulmonary samples still calls for validation. The BDProbeTec ET Mycobacterium tuberculosis Complex Direct Detection Assay (DTB) was applied to 918 consecutive extrapulmonary specimens (collected from 863 patients), including 84 gastric aspirates, 145 urine, 136 sterile body fluids, 83 cerebrospinal (CSF) fluids, 237 fine-needle aspirates, 175 pus, 56 biopsies, and two stool specimens.

Tuberculosis in kindergarten and primary school, Italy, 2008-2009.

An outbreak of tuberculosis (TB) in Italy involved 19 schoolchildren with active TB and 43 with latent infection. The source of the outbreak was a school assistant born in Italy who had a family history of TB. This outbreak highlights the need for maintaining clinical and public health expertise in countries with low TB incidence.

Extrapulmonary infections associated with nontuberculous mycobacteria in immunocompetent persons.

Over the past several years, the prevalence of human disease caused by nontuberculous mycobacteria (NTM) has increased. Whether the increase in cases is real or whether more cases are being recognized remains unclear. Despite a considerable increase in knowledge about NTM infections, they still represent a diagnostic and therapeutic challenge for several reasons: 1) pathogenic isolates may be indistinguishable from contaminant or saprophytic isolates; 2) timely and reliable identification of isolates may depend on proper communication between clinicians and laboratory staff; 3) lack of standardized susceptibility testing makes adoption of tailored therapies unrealistic; and 4) lack of treatment guidelines exposes patients to toxic drugs and disappointing outcomes.

Unreliable detection of Mycobacterium xenopi by the nonradiometric Bactec MGIT 960 culture system.

From June 2006 to December 2007, 3,648 clinical specimens consecutively received for mycobacterial culture were investigated. Each processed sample was inoculated into Bactec MGIT 960 liquid medium and a Löwenstein-Jensen slant. Tubes that were flagged as positive by the instrument as well as those determined to be negative after 42 days of incubation were removed, visually inspected for growth, and checked for the presence of acid-fast bacilli.

Diagnostic accuracy of in-house PCR for pulmonary tuberculosis in smear-positive patients: meta-analysis and metaregression.

In-house PCR (hPCR) could speed differential diagnosis between tuberculosis (TB) and nontuberculous mycobacterial disease in patients with positive smears and pulmonary infiltrates, but its reported accuracy fluctuates across studies. We conducted a systematic review and meta-analysis of hPCR sensitivity and specificity for smear-positive TB diagnosis, using culture as the reference standard. After searching English language studies in MEDLINE and EMBASE, we estimated cumulative accuracy by means of summary receiver operating characteristic analysis.

Pulmonary infections associated with non-tuberculous mycobacteria in immunocompetent patients.

A decline in the prevalence of tuberculosis in the developed world over the past several years has been accompanied by an increase in the rate of mycobacterial disease caused by non-tuberculous mycobacteria. However, it is still unclear whether there is a real increase in prevalence or whether non-tuberculous mycobacterial disease is being recognised more frequently by clinicians in a variety of clinical settings, thus enhancing the competence of microbiologists to detect the more unusual and fastidious mycobacteria. The introduction of liquid media for isolation of mycobacteria coupled with more accurate methods for identification have allowed several new species associated with human disease to be recognised.

Validation of the agar proportion and 2 liquid systems for testing the susceptibility of Mycobacterium tuberculosis to moxifloxacin.

Moxifloxacin (MOX), an 8-methoxyquinolone compound, is now widely used for the treatment of bacterial infections and also accepted as 2nd-line drug for the treatment of multidrug-resistant (MDR) tuberculosis. To tentatively correlate the clinical outcome with in vitro results, we sought to set up susceptibility test conditions for Mycobacterium tuberculosis against MOX by using the reference agar proportion method, the BACTEC 460 radiometric system, and the recently validated nonradiometric BACTEC MGIT 960 system. Our aim was to determine the critical MOX test concentration to be used with the abovementioned methods for routine susceptibility testing.

Comparison of tuberculin skin test and Quantiferon immunological assay for latent tuberculosis infection.

Background: Correct identification of individuals with latent tuberculosis infection (LTBI) is a crucial element of the elimination strategy, allowing their adequate treatment. In addition to tuberculin skin test (TST), the Quantiferon test (QFT, based on whole blood gamma-interferon release) had been recently proposed. Aim of the study is to compare this test to TST for identification of LTBI in a non-selected population, in order to verify their value in identifying truly infected individuals (entitled to receive preventive chemotherapy), and to exclude from treatment those having a positive TST for other reasons (e.

Clinical suspicion as a primary guidance to use commercial amplification tests for rapid diagnosis of pulmonary tuberculosis.

The Abbott LCx (Abbott Park, IL) Mycobacterium tuberculosis complex is a commercial amplification assay discontinued from the European market in 2002. A prospective clinical study was carried out to evaluate the clinical utility of the above test as applied by specialists for the rapid diagnosis of active pulmonary tuberculosis (PTB). According to the physician's clinical judgment, patients were classified into 3 groups (low, intermediate, and high) aiming to estimate the probability of active disease.

Drug resistance evolution of a Mycobacterium tuberculosis strain from a noncompliant patient.

The emergence and spread of multidrug-resistant (MDR) Mycobacterium tuberculosis (MT) represents a worldwide health care problem because of the difficulty in treating these infections. Development of drug resistance in MT arises mainly by mutation of chromosomal genes. To investigate the evolution of a MT population during a long-lasting infection, the phenotypic and genotypic changes in the drug resistance of 10 sequential MT isolates from a noncompliant chronically infected patient were investigated.

Mycobacterial testing in hospital laboratories: results from a questionnaire survey in Italy.

Between 1999 and 2001, 355 hospital laboratories in Italy were asked to complete a questionnaire addressing mycobacterial test methods, 1-year workloads and laboratory safety features. Analysis of the data showed that rapid methods for mycobacterial testing were being used by most larger laboratories; however, sub-optimal methods were still in use in small and medium-size laboratories. In a country such as Italy, which has a low prevalence of tuberculosis cases, implementation of rapid technologies, combined with regionalisation of mycobacterial diagnostic services, seems to be the most reasonable and cost-effective strategy.

Mycobacterium triplex pulmonary disease in immunocompetent host.

Mycobacterium triplex, a recently described, potentially pathogenic species, caused disease primarily in immunocompromised patients. We report a case of pulmonary infection due to this mycobacterium in an immunocompetent patient and review the characteristics of two other cases. In our experience, Mycobacterium triplex pulmonary infection is unresponsive to antimycobacterial chemotherapy.