Detection of multiple viral and bacterial infections in acute exacerbation of chronic obstructive pulmonary disease: a pilot prospective study.

Few studies have evaluated the contribution of multiple virus and bacterial infections in acute exacerbation of chronic obstructive pulmonary disease. This study estimated the burden of multiple viral and bacterial respiratory infections in moderate to very severe chronic obstructive pulmonary disease patients that were prospectively followed-up during a 12-month pilot study. Clinical data were collected monthly and sputum was collected at the time of each acute exacerbation event. Classical culture techniques for bacteria and multiplex polymerase chain reaction (PCR) and microarray detection assays were performed to identify viral and atypical bacterial pathogens in the sputum. Overall, 51 patients were included and 45 acute exacerbation events were investigated clinically and microbiologically. Among the 45 acute exacerbation events, 44% had evidence of viral infection involving human rhinovirus (HRV) and metapneumovirus (hMPV) in 20% and 18%, respectively. Intracellular bacteria were not found in sputum by PCR. Common bacterial pathogens were identified in 42% of acute exacerbation patients, most frequently Branhamella catarrhalis, Streptococcus pneumoniae and Haemophilus influenzae. Viral or virus and bacteria co-infections were detected in 27% of acute exacerbation events (n = 12) with HRV and hMPV involved in 92% of cases. Patients with co-infections did not present greater clinical severity scores at exacerbation and more recurrence of acute exacerbation events at 3 and 6 months than those with single infections (P > 0.4). These results suggest that HRV and hMPV may be contributors or cofactors of AECOPD. These findings indicate that viral or virus and bacterial co-infections do not impact significantly on the clinical severity of acute exacerbation of chronic obstructive pulmonary disease and recurrence at 3 and 6 months.

Rapid detection of aac(6')-Ib-cr quinolone resistance gene by pyrosequencing.

Pyrosequencing was used to rapidly detect aac(6')-Ib and aac(6')-Ib-cr genes. This plasmid-mediated quinolone resistance determinant is increasing in extended-spectrum beta-lactamase-producing Enterobacteriaceae. This method is faster and more cost-effective than the methods previously described. Sequences obtained with this pyrosequencing method showed 100% concordance with conventional sequencing.

[Differences between species involved and fluoroquinolone resistance patterns of strains isolated from bacteriuria according to nosocomial, health-related or community-acquired onset]. / Différences d'espèces en cause et de résistance aux fluoroquinolones des souches isolées dans les bactériuries selon leur caractère nosocomial, lié au soin ou communautaire.

PURPOSE: To describe and to compare species and antibiotics resistance patterns of bacteria involved among bacteriuria from hospital and city laboratories and among health-related and community-acquired bacteriuria. METHODS: Epidemiologic transversal study conducted among Bacteriology laboratories of University Hospital (UH) and the whole city of Reims, during the week 21 to 26 June 2010. A standardized investigation form was completed after telephonical interview with the prescriber. RESULTS: One hundred and eighty-nine strains have been isolated among 179 urocultures. One hundred and seven strains were isolated in city laboratories and 82 in UH laboratory. Strains were community-acquired, health-related and nosocomial in 136, 22 and 31 cases, respectively. More Gram positive bacteria and ofloxacin resistant strains were isolated among UH strains (P=0.001 and P=0.015, respectively) and among health-related strains (P=0.01 and P=0.003, respectively). When analysis was restricted only to Enterobacteriaceae or to Escherichia coli, the ofloxacin resistance rate was no more elevated among health-related or UH strains. Ofloxacin resistant Enterobacteriaceae were more frequently resistant to all other classes of antibiotics except nitrofurans. DISCUSSION: Strains isolated in health-related bacteriuria are more frequently ofloxacin resistant principally because of the greater proportion of Gram positive bacteria and because of a non-significant higher ofloxacin resistance rate among Enterobacteriaceae. Numerous studies only focus on Enterobacteriaceae, and the data from our study need to be confirmed on larger samples, in order to validate the predictive value of health-related bacteriuria for ofloxacin resistance.

Low SCL/TAL1 expression reveals its major role in adult hematopoietic myeloid progenitors and stem cells.

Stem cell leukemia/T cell acute leukemia 1 (SCL/TAL1) plays a key role in the development of murine primitive hematopoiesis but its functions in adult definitive hematopoiesis are still unclear. Using lentiviral delivery of TAL1-directed shRNA in human hematopoietic cells, we show that decreased expression of TAL1 induced major disorders at different levels of adult hematopoietic cell development. Erythroid and myeloid cell production in cultures was dramatically decreased in TAL1-directed shRNA-expressing cells, whereas lymphoid B-cell development was normal. These results confirm the role of TAL1 in the erythroid compartment and show TLA1's implication in the function of myeloid committed progenitors. Moreover, long-term cultures and transplantation of TAL1-directed shRNA-expressing CD34+ cells into irradiated nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice led to dramatically low levels of human cells of all lineages including the B-lymphoid lineage, strongly suggesting that TAL1 has a role in the early commitment of hematopoietic stem cells (HSCs) in humans. Cultures and transplantation experiments performed with mouse Sca1+ cells gave identical results. Altogether, these observations definitively show that TAL1 participates in the regulation of hematopoiesis from HSCs to myeloid progenitors, and pinpoint TAL1 as a master protein of human and murine adult hematopoiesis.