Sampling strategy for bacteriological diagnosis of intrathoracic tuberculosis.

BACKGROUND: Pulmonary tuberculosis (TB) is the most frequent site of TB and the one leading its spread worldwide. Multiple specimens are commonly collected for TB diagnosis including those requiring invasive procedures. This study aimed to review the sampling strategy for the microbiological diagnosis of pulmonary TB. METHODS: A retrospective analysis of collected samples from September 1st 2014 to May 1st 2016 in the Bacteriology laboratory of Pitié-Salpêtrière Hospital (Paris, France) was performed. All the samples collected in patients aged over 18 years for the bacteriological diagnosis of pulmonary TB were included. RESULTS: A total of 6267 samples were collected in 2187 patients. One hundred and twenty-six patients (6%) had a culture confirmed pulmonary TB. Among them, multiple sputum collections were sufficient for TB diagnosis in 63.5%, gastric lavages permitted to avoid bronchoscopy in only 7.1%, and bronchoscopy was necessary in 29.4%. The culture positivity of sputa (8.6%) was higher than that of bronchial aspirations (3.1%), bronchiolo-alveolar lavages (BAL) (2.3%) or gastric lavages (4.8%) (P<0.001). From its 70.0% theoretical PPV value, the 46.1% selection in bronchial aspirations allocated to molecular test increased PPV up to 88.9%. CONCLUSIONS: Based on our data, we suggest to collect sputum consistently. If smear negative a bronchoscopy should be performed and molecular diagnosis be performed on a subset of bronchial aspirations based on expertise of the bronchoscopist.

Multidrug and extensively drug-resistant tuberculosis.

The emergence of drug-resistant tuberculosis (TB) compromises global tuberculosis control. The incidence of multidrug-resistant strains (MDR) defined as resistant to the two main antituberculosis drugs, rifampicin and isoniazid, was raised in the 1990s. Ten percent of these strains have developed additional resistance to the main second-line antituberculosis drugs: fluoroquinolones and aminoglycosides. These strains are defined as extensively drug-resistant (XDR). The prognosis of MDR-TB and XDR-TB is poor due to limited therapeutic resources. However, many new innovations may lead to a radical change in this field. Genotypic testing is now able to detect drug resistance within a few hours. Genotypic diagnosis of rifampicin resistance is now recommended in France for each new case of TB. The currently recommended treatment for MDR-TB is long (18-24 months) and toxic. It is, however, on the verge of being replaced by a 9-month treatment. New antituberculosis drugs such as bedaquiline and delamanid should also improve the prognosis of MDR-TB and XDR-TB.

The reversed halo sign: pathognomonic pattern of pulmonary mucormycosis in leukemic patients with neutropenia?

BACKGROUND: Pulmonary mucormycosis (PM) is a life-threatening fungal infection with an increasing incidence among patients with acute leukemia. In some immunocompromised hosts, the reversed halo sign (RHS) has been described on the pulmonary computed tomographic (CT) scan of patients with mucormycosis. METHODS: This study reports a single-center experience with PM exclusively in patients with acute leukemia. Clinical records, laboratory results, and CT scans were retrospectively analyzed to evaluate the clinical usefulness of the RHS for the early identification and treatment of PM, with regard to outcomes in these patients. RESULTS: Between 2003 and 2012, 16 cases of proven PM were diagnosed among 752 consecutive patients receiving chemotherapy for acute myeloblastic or lymphoblastic leukemia. At the time PM was diagnosed, all patients but one were neutropenic. The study of sequential thoracic CT scans showed that during the first week of the disease, the RHS was observed in 15 of 16 patients (94%). Initially, other radiologic findings (multiple nodules and pleural effusion) were less frequent, but appeared later in the course of the disease (6% and 12% before vs 64% and 55% after the first week). After the diagnosis of PM, median overall survival was 25 weeks (range, 3-193 weeks), and 6 patients (38%) died before day 90. CONCLUSIONS: In the particular setting of neutropenic leukemia patients with pulmonary infection, the presence of the RHS on CT was a strong indicator of PM. It could allow the early initiation of appropriate therapy and thus improve the outcome.

Galanin receptor 2 overexpressing mice display an antidepressive-like phenotype: possible involvement of the subiculum.

The behavioral phenotype of a transgenic mouse overexpressing a galanin receptor 2 (GalR2)-enhanced, green fluorescent protein (EGFP)-construct under the platelet-derived growth factor-B promoter, and of controls, was assessed in various behavioral tests, such as the Porsolt forced swim test, as well as the open field, elevated plus maze and passive avoidance tests. In addition, the distribution of GalR2-EGFP expressing cell bodies and processes was studied in the brain of these mice using histochemical methods. Three age groups of the transgenic mice demonstrated decreased levels of immobility in the forced swim test, indicative of antidepressive-like behavior and/or increased stress resistance. Anxiety-like behaviors, measured in two different tests, did not differ between the GalR2-overexpressing and the wild-type mice, nor did motor activity levels, emotional learning or memory behaviors. High levels of GalR2 mRNA and protein expression were observed in the presubiculum, subiculum, cingulate cortex, retrosplenial granular and agranular cortices, subregions of prefrontal cortex, and the olfactory bulb, regions which are directly or indirectly implicated in depression-like behavior. These results may contribute to the understanding of the pathophysiology of major depressive disorder and the role of GalR2 in the regulation of mood, and suggest a potential therapeutic effect by targeting the GalR2 for treatment of depressive disorders.