Véronique Duval

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. J. Med. Virol. 85:866–873, 2013.

Rapid Detection of aac(6′)-Ib-cr Quinolone Resistance Gene by Pyrosequencing

ABSTRACT 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.

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

ABSTRACT 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.

Mise au point d’une technique de PCR en temps réel pour la détection rapide des gènes qnr chez des entérobactéries productrices de bêta-lactamases à spectre étendu

AIM OF THE STUDY To develop a fast and reliable real time PCR technique for detecting plasmid-mediated quinolone resistance genes qnrA, qnrB and qnrS. METHODS A real-time PCR assay using SYBR Green I and Roche LightCycler(®) was developed to detect qnr genes. Detection of qnr genes was based on comparison of melting temperature differences with a positive control of each qnr genes. This assay was performed to study 138 isolates collected from diagnostic and screening samples in the Champagne-Ardenne region in 2004 (France). RESULTS In optimized conditions, the three positive controls tested alone and with isolates confirmed the specificity of the PCR primers. Each PCR assay was able to test 30 strains in 60min for 1 qnr gene. Out of 138 isolates screened, 3.6 % isolates were positive for a qnrA1, 1.5 % for qnrS1 and no qnrB-like gene. Prevalence of qnr determinants was 5 % and reached 9.5 % in clinical isolates. CONCLUSION Real-time PCR is a fast and reliable technique for screening of qnr-positive strains. This study shows a relatively high prevalence of qnr determinants (5 %) among ESBL-producing Enterobacteriaceae.

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.

COL8-03 Évaluation de l’antigénurie Streptococcus pneumoniae dans le diagnostic précoce de 333 pneumonies de l’adulte en réanimation

Introduction L’importance pronostique sur la mortalite et sur l’incidence des complications d’un traitement precoce et adapte des pneumonies a pneumocoque est connue. Streptococcus pneumoniae constitue l’etiologie la plus frequente et la plus grave. Le but de cette etude etait d’evaluer le test BINAX NOW S. pneumoniae dans le diagnostic precoce des pneumonies chez les patients ventiles en reanimation. Materiel et methodes Etude prospective de 2003 a 2006, incluant les pneumopathies communautaires hypoxemiantes (score de FINE V). Le diagnostic de pneumonie reposait sur les criteres d’ANDREW. Recueil : âge, sexe, IGS II, antibiotherapie prealable. Un lavage broncho-alveolaire (LBA), des hemocultures (HC), une antigenurie S. pneumoniae etaient effectues des l’admission. Deux groupes etaient individualises. Groupe I : patients infectes a S. pneumoniae , Groupe II : patients non infectes a S. pneumoniae . Resultats Inclusion de 333 patients. Âge moyen : 59 ans, sex ratio de 3, IGS II a 41, 65 % avaient recu une antibiotherapie avant les prelevements. 52 patients (groupe I) presentaient une pneumonie a S. pneumoniae dont 11 associes a une bacteriemie. Le groupe II comprenait 281 patients. 60 patients avaient une antigenurie positive, 21 patients du groupe I et 39 patients du groupe II. La sensibilite (Se) est egale a 40,4 % [24 %-62,8 %] IC 95 % et la specificite (Sp) a 86,1 % [64,4 %-85,6 %] IC 95 %. La VPP n’etait que de 35 % alors que la VPN etait de 88,6 %. En prenant comme test de reference l’HC seule, la Se etait de 45,5 % [22,1 %-59,3 %] IC 95 % et la Sp de 82,9 % [57,7 %-85,6 %] IC 95 %. Conclusions L’interet du test reside dans la rapidite du resultat et du caractere non invasif de cette technique, mais la sensibilite mediocre de ce test incite a ne plus pratiquer cet examen en reanimation.