Nicolas Degand

Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Nonfermenting Gram-Negative Bacilli Isolated from Cystic Fibrosis Patients

ABSTRACT The identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis (CF) patients is usually achieved by using phenotype-based techniques and eventually molecular tools. These techniques remain time-consuming, expensive, and technically demanding. We used a method based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the identification of these bacteria. A set of reference strains belonging to 58 species of clinically relevant nonfermenting gram-negative bacilli was used. To identify peaks discriminating between these various species, the profile of 10 isolated colonies obtained from 10 different passages was analyzed for each referenced strain. Conserved peaks with a relative intensity greater than 0.1 were retained. The spectra of 559 clinical isolates were then compared to that of each of the 58 reference strains as follows: 400 Pseudomonas aeruginosa, 54 Achromobacter xylosoxidans, 32 Stenotrophomonas maltophilia, 52 Burkholderia cepacia complex (BCC), 1 Burkholderia gladioli, 14 Ralstonia mannitolilytica, 2 Ralstonia pickettii, 1 Bordetella hinzii, 1 Inquilinus limosus, 1 Cupriavidus respiraculi, and 1 Burkholderia thailandensis. Using this database, 549 strains were correctly identified. Nine BCC strains and one R. mannnitolilytica strain were identified as belonging to the appropriate genus but not the correct species. We subsequently engineered BCC- and Ralstonia-specific databases using additional reference strains. Using these databases, correct identification for these species increased from 83 to 98% and from 94 to 100% of cases, respectively. Altogether, these data demonstrate that, in CF patients, MALDI-TOF-MS is a powerful tool for rapid identification of nonfermenting gram-negative bacilli.

Nocardia pseudobrasiliensis as an Emerging Cause of Opportunistic Infection after Allogeneic Hematopoietic Stem Cell Transplantation

ABSTRACT We report the case of a 55-year-old man who exhibited a nodular pneumonia 4 months after an allogeneic hematopoietic stem cell transplantation. Culture of the bronchoalveolar lavage fluid revealed Nocardia pseudobrasiliensis. This recently described carbapenem-resistant species should be included in the differential diagnosis of fungal infection in this setting.

Impact of the 13-valent pneumococcal conjugate vaccine on nasopharyngeal carriage of Streptococcus pneumoniae among children attending group daycare in southeastern France.

Regular surveys of pneumococcal nasopharyngeal carriage have been conducted among children attending daycare centers in Southeastern France from 1999 to 2012. We compared carriage rate, susceptibility patterns and serotype distribution in 2012, following implementation of the 13-valent pneumococcal conjugate vaccine, with findings from 5 previous surveys. Carriage rate was stable, antibiotic susceptibility improved and only serotype 19A persisted among vaccine-types.

Epidemic spread of Pandoraea pulmonicola in a cystic fibrosis center

BackgroundPandoraea spp. are recently discovered bacteria, mainly recovered from cystic fibrosis (CF) patients, but their epidemiology and clinical significance are not well known. We describe an epidemic spread of Pandoraea pulmonicola from 2009 in our CF center, involving 6 out of 243 CF patients.MethodsBacterial identification used amplified ribosomal DNA restriction analysis (ARDRA), MALDI-TOF mass spectrometry (MALDI-TOF MS) and 16S rDNA gene sequencing. The clonal link between strains was assessed with pulsed field gel electrophoresis (PFGE) using XbaI. Clinical data were gathered for all patients.ResultsThe index case was chronically colonized since 2000. The main hypothesis for this bacterial spread was a droplet cross-transmission, due to preventive measures not being strictly followed. Antibiotic susceptibility testing revealed resistance to beta-lactams, ciprofloxacin and colistin. However, there was susceptibility to trimethoprim-sulfamethoxazole. All patients were chronically colonized with Pseudomonas aeruginosa, and the acquisition of P. pulmonicola resulted in chronic colonization in all patients. Three patients died, and two patients remained clinically stable, whereas one patient had a decline in lung function.ConclusionsThis study, which is the first to describe an epidemic spread of P. pulmonicola, notes the potential transmissibility of this bacterial species and the need for infection control measures.

Lumbar Discitis Caused by Clostridium perfringens

ABSTRACT We report here a rare case of chronic lumbar discitis caused by Clostridium perfringens in an elderly patient that was treated with a combination of β-lactams and clindamycin. Molecular analysis performed on the strain revealed an unusual toxin gene pattern.

Improved quality of care for patients infected or colonised with ESBL-producing Enterobacteriaceae in a French teaching hospital: impact of an interventional prospective study and development of specific tools

The increasing incidence of ESBL-producing Enterobacteriaceae (ESBL-E) in France prompted the publication of national recommendations in 2010. Based on these, we developed a toolkit and a warning system to optimise management of ESBL-E infected or colonised patients in both community and hospital settings. The impact of this initiative on quality of care was assessed in a teaching hospital. The ESBL toolkit was developed in 2011 during multidisciplinary meetings involving a regional network of hospital, private clinic and laboratory staff in Southeastern France. It includes antibiotic treatment protocols, a check list, mail templates and a patient information sheet focusing on infection control. Upon identification of ESBL-E, the warning system involves alerting the attending physician and the infectious disease (ID) advisor, with immediate, advice-based implementation of the toolkit. The procedure and toolkit were tested in our teaching hospital. Patient management was compared before and after implementation of the toolkit over two 3-month periods (July–October 2010 and 2012). Implementation of the ESBL-E warning system and ESBL-E toolkit was tested for 87 patients in 2010 and 92 patients in 2012, resulting in improved patient management: expert advice sought and followed (16 vs 97%), information provided to the patient’s general practitioner (18 vs 63%) and coding of the condition in the patient’s medical file (17 vs 59%), respectively. Our multidisciplinary strategy improved quality of care for in-patients infected or colonised with ESBL-E, increasing compliance with national recommendations.

Managing ESBL-producing Enterobacteriaceae-related urinary tract infection in primary care: a tool kit for general practitioners

In Southern France, approximately 4% of E. coli isolates from community-acquired urinary tract infections are extended spectrum beta-lactamase producers, while carriage rates for enterobacteriaceae (ESBL-E) range from 3 to 6%. General practitioners (GP) are unfamiliar with the management of patients harboring ESBL-E. Providing them with a specific tool kit should assist in their therapeutic approach and optimize antimicrobial prescription an ESBL-E tool kit was developed by a multidisciplinary team: infectious diseases (ID) specialists, microbiologists, pharmacologists, and nursing home staff. This tool kit includes treatment protocols, GP and patient information leaflets, a list of infection control measures, and contact details of ID physicians for specialized advice. A community-based (including nursing homes) prospective study was conducted in 2012 in Southeastern France to test the tool kit in the context of ESBL-E-related urinary tract infections (UTI). ESBL-E-related UTI were identified in 88 patients, 66 GPs were contacted by the microbiology laboratory, 56 stated they were offered the tool kit, 48 said they had received it, and 41 stated they had read its contents. Use of the tool kit was significantly correlated with appropriate antibiotic prescription, which concerned 36/39 tool kit users versus 13/20 non-users (p = 0.0125) and 40 GPs expressed an average satisfaction rate of 4.2 on a scale of 0 to 5. Availability of a specific tool for managing patients harboring ESBL-E, now completed with a website, can assist community-based GPs and improve antimicrobial prescription.