Characterization of biofilms formed by Candida parapsilosis, C. metapsilosis, and C. orthopsilosis

Infections due to Candida parapsilosis have been associated with the ability of this fungus to form biofilms on indwelling medical devices. Recently, C. parapsilosis isolates were reclassified into 3 genetically non-identical classes: C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Little information is available regarding the ability of these newly reclassified species to form biofilms on biomedical substrates. In this study, we characterized biofilm formation by 10 clinical isolates each of C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Biofilms were allowed to form on silicone elastomer discs to early (6 h) or mature (48 h) phases and quantified by tetrazolium (XTT) and dry weight assays. Surface topography and three-dimensional architecture of the biofilms were visualized using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), respectively. Metabolic activity assay revealed strain-dependent biofilm forming ability of the 3 species tested, while biomass determination revealed that all 3 species formed equivalent biofilms (P>0.05 for all comparisons). SEM analyses of representative isolates of these species showed biofilms with clusters of yeast cells adherent to the catheter surface. Additionally, confocal microscopy analyses showed the presence of cells embedded in biofilms ranging in thickness between 62 and 85 μm. These results demonstrate that similar to C. parapsilosis, the 2 newly identified Candida species (C. orthopsilosis and C. metapsilosis) were able to form biofilms.     

Emergence of Candida parapsilosis candidemia at Cochin hospital. Characterization of isolates and search for risk factors

Candida parapsilosis is a normal saprophyte of the skin, characterized by their affinity for catheters. This species has, in vitro, a level of sensitivity against the echinocandins, significantly lower than that observed with other Candida species. Recently, new species: Candida orthopsilosis and Candida metapsilosis, phenotypically identical to C. parapislosis, have been identified by molecular biology. From 2003 to 2007, in the Cochin hospital, the proportion of C. parapsilosis among non-albicans species isolated from blood cultures increased from 17 (3/18) to 38% (5/13). To understand the reasons for this emergence, we retrospectively characterized isolates, conducted a case-control and researched a link between the emergence and introduction of caspofungin in our hospital. We analysed data from 26 patients who had candidemia with C. parapsilosis. Genotypic analysis of isolates has not identified the new species C. orthopsilosis and C. metapsilosis. The case-control study showed a broad-spectrum antibiotics was significantly more frequent for candidemia with C. parapsilosis compared to C. albicans (52 versus 26%, P = 0.04) as a previous treatment with caspofungin (11 versus 0%, P = 0.04). The introduction of caspofungin is contemporary with the emergence of candidemia with C. parapsilosis with a tendency to be related to its level of consumption in the ICU. Our results should encourage biologists to closely monitor the frequency and level of sensitivity of strains of C. parapsilosis isolated in hospital.     

Place de Streptococcus pyogenes dans les angines au Maroc et état actuel de sa sensibilité aux antibiotiques

Objective

In this study we report the prevalence of the throat infections to Streptococcus pyogenes in child and adult in Morocco, and the current antimicrobial susceptibility of the aminopenicillins and erythromycin.

Patients and methods

A prospective surveillance study was made from March 2006 to February 2007 in four primary health care in Rabat and Sale cities. Six hundred and ninety-seven patients (494 children and 203 adults) were the object of samplings by throat cotton swab probe, for researching the group A Streptococcus (GAS). The patients were those proposed by their doctors for the treatment of throat infections. The antimicrobial susceptibility was realized by two methods: the disc-diffusion method on Mueller–Hinton agar plates and MICs were determined by E-test. The antibiotics tested were the penicillin G, the amoxicillin and the erythromycin.

Results

S. pyogenes was identified in 65 cases (9.3%): 45 strains in children (9.1%) and 20 strains in adults (9.9%). Two peaks of throat infections to S. pyogenes were recorded in children aged 12 to 15 years and in adults between 36 and 39 years old. All strains were susceptible to penicillin G and amoxicillin. One strain was resistant to erythromycin with a MIC greater than 256 μg/mL.     

Évaluation des risques microbiologiques hydriques associés à Stenotrophomonas maltophilia et Pseudomonas aeruginosa au CHU d’Amiens

Background

Pseudomonas aeruginosa (Psa) and Stenotrophomonas maltophilia (Smalto) are major opportunistic waterborne pathogens causing hospital-acquired infections. This study aimed to assess the biocontamination level of cold water used in Amiens’ university hospital wards, from March to June 2008.

Methods

We cultivated 122 pairs of cold water first jet and taps cotton-swabs on Cetrimide agar for Psa, on Stenotrophomonas maltophilia selective medium with coloured indicator (SM2i) for Smalto, on Mueller Hinton agar used as isolation medium reference for both, 48 h at 30 °C. Data analysed with Épi-Info 6.04dFr were compared with chi² test, significant at p < .05.

Results

Psa and Smalto were isolated in 26.2 and 14.8% of water samples and in 21.3 and 10.7% of swab samples respectively. They were associated in 11.5% of water samples and 5% of swab samples. Psa was alone in 13.1% of water samples and 7.4% of swab samples whereas Smalto was found in 6.6% of water and 2.5% of swabs. Psa and Smalto were isolated from 14.8% of water samples and 8.2% of swab samples of the same tap. Finally, respectively 35.2 and 17.2% of the cold water taps were biocontaminated by Psa and Smalto. In fact, microbiologic water taps contamination risk was two-fold higher for Psa than for Smalto, p < .001, without variation between wards.

Conclusion

Sm2i and Cetrimide are suited and efficient medium respectively for Smalto and Psa isolation. Cold-water samples are sufficient for waterborne pathogens biocontamination risk appraisal. Our results urged healthcare workers on efficient water fittings microbiologic risk control to prevent healthcare associated waterborne infections, notably due to Psa and Smalto.     

Évolution du nombre d’infections à Rotavirus et à virus respiratoire syncytial chez les enfants hospitalisés au CHU de Dijon entre 1998 et 2005

Aim

Respiratory syncytial virus (RSV) and Rotavirus infections represent up to 30% of cross infections in pediatric units. As they are a major public health problem, we studied their evolution and distribution at the Dijon University Hospital.

Population and methods

This exhaustive retrospective study included children under 15 with a new Rotavirus or RSV infection who were hospitalised at the Dijon University Hospital between 1998 and 2005. The general trend was determined by using moving averages, and the Spearman correlation coefficient r_s was calculated.

Results

From 1998 to 2005, 1886 new RSV (n = 981) or Rotavirus (n = 905) infections were identified in hospitalised children. The number of the infections decreased significantly, both for RSV (r_s = −0.71 ; p < 0.0001) and for Rotavirus (r_s = −0.77 ; p < 0.0001). Almost half of Rotavirus infections were nosocomial (46.3%) vs 5.3% of RSV infections, p < 0.0001. There was no significant difference in the proportion of RSV nosocomial infections between the epidemic and non-epidemic period (4.9% of nosocomial infections vs 7.1% respectively, p = 0.25). Rotavirus nosocomial infections were less frequent in epidemic period (41.6%) than in non-epidemic period (54.6%); p = 0.0002.

Conclusion

RSV and Rotavirus infections significantly decreased between 1998 and 2005. Proportion of RSV or Rotavirus infections didn’t increase in epidemic period, which could be explained both by an increased attention from healthcare professionals and by the effectiveness of hygiene measures taken.     

Évaluation des activités antioxydante et anti-inflammatoire de Erica arborea L. du Maroc

Aim

The present study was carried out to evaluate the antioxidant and anti-inflammatory capacity, and acute toxicity of Moroccan Erica arborea leaves.

Methods

Antioxidant capacity was assessed by diphenyle-picryl-hydrazyl (DPPH), phosphomolybdate (PPM) and ferric reducing antioxidant power (FRAP) tests and anti-inflammatory capacity was evaluated by hind paw oedema model using carrageenan-induced inflammation in rat. The acute toxicity was evaluated using mice.

Results

Acute toxicity of ethanolic extract of E. arborea showed no sign of toxicity at dose of 5 g/kg B.W. Our extracts have important antioxidant properties. The efficient concentration of the ethanolic extract (10.22 μg/ml) required for decreasing initial DPPH concentration by 50% was comparable to that of standard solution butyl-hydroxy-toluene (BHT) (8.87 μg/ml). The administration of ethanolic extract at doses of 200 and 400 mg/kg B.W. was able to prevent plantar oedema and exhibited a significant inhibition against carrageenan-induced inflammation when compared to the control group (NaCl 0.9%) but comparable to those of diclofenac (reference drug).

Conclusions

Our results show that the leaves of E. arborea may contain some bioactive compounds which are responsible for the antioxidant and anti-inflammatory activities observed here. Our finding may indicate the possibility of using the extracts of this plant to prevent the antioxidant and inflammatory processes.     

Phénotypes de l’alpha-1-antitrypsine dans la population togolaise : mise en évidence d’une fréquence élevée de l’allèle rare Pi dans une ethnie isolat

Objectives

The study, which is a ethnobiologic characterization, investigated α₁-antitrypsin gene polymorphism in the togolese ethnic groups. We aimed to determine the existence of rare or deficient alleles predisposing to pulmonary or hepatic genetic diseases.

Patients and methods

We focused our study on healthy subjects of two samples by comparing 205 Adélé from relative isolated ethnic group alive in mountain region and 255 subjects from pluriethnic population living on Atlantic coastal region. Data analysis was performed by α₁-antitrypsin level quantification and serum isoelectric focusing.

Results

The two alleles Pi^M et Pi^F frequencies are respectively 0.834 and 0.166 in Adélé; 0.989 and 0.011 in the subjects from pluriethnic population. Phenotypes MM and FM distribution in the two groups is significantly different (p < 0.001). However, α₁-antitrypsin polymorphism does not significantly influence proteinic and lipidic profiles of the subjects in the two samples.

Conclusion

The Pi^F allele of α₁ antitrypsin is rare allele in the world global populations. Its very high frequency in Adélé explained by preferential endogamic marriage in this ethnic group. Compared to the subjects from pluriethnic population, more than 30 Adélé subjects present a higher risk to develop pulmonary diseases according to isoform F properties.     

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 60 min 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.     

Évolution de la résistance aux antibiotiques de Pseudomonas aeruginosa dans un centre hospitalier universitaire entre 2002 et 2006

Aim of study

Monitor evolution of antibiotic resistance of Pseudomonas aeruginosa from 2002 to 2006 in our hospital to optimize antibiotherapy.

Patients and method

The infections/colonizations with P. aeruginosa have been identified by the hospital's informatic database. Bacteriological samples realized 48 hours after patient's admission was considered as nosocomial. A Cochran-Armitage test was conducted to assess the evolution of resistance.

Results

During this period, 2098 infections/colonizations with P. aeruginosa have been identified. Bacteriological samples (68.5%) were nosocomial. Among the β-lactam antibiotics, ceftazidime and imipenem were the most active (R = 16.8% and 15.2%, respectively), followed by piperacillin and piperacillin–tazobactam (R = 24.8%, 18.4%, respectively). Amikacin and tobramycin were more active than gentamicin (R = 19.9%; 22.2% and 40.6%, respectively). 28.9% of strains were resistant to ciprofloxacin. Nosocomial strains were significantly more resistant than non-hospital strains: ceftazidime: 17.9% versus 14.2%, p = 0.0346; ticarcillin–clavulanic acid: 47.5% versus 39.6%, p = 0.0009; piperacillin–tazobactam: 20.0% versus 14.8%, p = 0.0046; ciprofloxacin: 30.7% versus 25.2%, p = 0.0112. A significant increase in the resistance of nosocomial strains to ceftazidime, ticarcillin–clavulanic acid and piperacillin–tazobactam was noted. Resistance from non-hospital strains to fluoroquinolones, aminoglycosides, ceftazidime, piperacillin and ticarcillin–clavulanic acid decreased significantly.

Conclusion

P. aeruginosa is a predominantly nosocomial microorganism. There is a decrease of resistance for non-hospital strains. But the resistance of nosocomial strains to antibiotics widely prescribed in hospital is worrying.     

Importance de la PCR dans la gestion d’une épidémie à Mycoplasma pneumoniae au centre hospitalier de Béthune (Pas-de-Calais)

Subject

Molecular amplification (PCR) provides adequate rapid and specific diagnosis of Mycoplasma pneumoniae infection (first agent responsible for community-wide bacterial pneumonia in children above 5 years of age).

Method

Positive (Chlamylège^®, Argène) PCR in nasopharyngeal aspirate, respiratory samples and nasopharyngeal swab and/or positive serological test (ELISA).

Results

Diagnosis of M. pneumoniae infection in 39 cases: 31 between September and December 2008 (30 children and one adult) and eight since June 2009 (three adults and five children). Children (mean age: 3.6 years) were hospitalized in 88.6% of cases, mean hospitalization duration was 2.9 days for respiratory tract infections, mainly due to lack of response to β-lactamines therapy (65.7%). Four adults (mean age: 29.5 years) presented a pneumonia, with hospitalization for three of them with one in intensive care unit. Twenty-eight PCR have proved positive (87%): without associated serology (13), eight negative serologies, IgG and IgM positive (five), and IgG alone (two). Seven patients had only serological test for diagnosis: IgM ± IgG. For two children, IgM positive only in isolation, with a PCR probably false negative.

Conclusion

The sensitivity of the serology in the diagnosis of mycoplasma infection is limited: IgM, which appear traditionally 1 week after clinical signs are mostly inexistent for adults and IgG rise at a later stage. Early diagnosis of child pneumoniae by PCR helped rapidly characterize this epidemic phenomenon and adapt the treatment.     

Activité du doripénème sur les bactéries anaérobies strictes

Aims of the study

This study examines the activity of doripenem, a new carbapenem compound compared with amoxicillin-clavulanic acid, piperacillin + tazobactam, imipenem, clindamycin and metronidazole against 316 anaerobes.

Methods

Inoculum preparation and agar dilution method were performed according to the CLSI method for anaerobes (M11A7).

Results

At a concentration of 4 μg/ml doripenem and imipenem (IMP) inhibited 122 (96 %) and 126 (99 %) strains of the Bacteroides fragilis group, respectively. In contrast, doripenem appeared more potent than IMP against Gram-positive anaerobes inhibiting at the same concentration of 4 μg/ml 145/145 strains (100 %) versus 115/145 for IMP (79.3 %). Against 316 anaerobic strains, the carbapenem doripenem had an MIC₅₀ of 0.25 μg/ml and an MIC₉₀ of 2 μg/ml. Results were similar to those for imipenem (MIC₅₀ of 0.125 μg/ml and MIC₉₀ of 4 μg/ml). If we consider the resistant breakpoints of the two carbapenems as defined by EUCAST, the resistance rate for doripenem (MIC > 4 μg/ml) 1.6 % is similar to that of imipenem (MIC > 8 μg/ml) 1.3 %.

Conclusion

Thus independently of the PK/PD parameters the two carbapenems demonstrated very close activity; doripenem was more potent on Gram-positive anaerobes and slightly less potent against Gram-negative anaerobes mainly the B. fragilis group. Further clinical studies are needed to assess its usefulness in patients.     

La mise au point d’un milieu sensible,spécifique et prédictif de recherche de Stenotrophomonas maltophilia dans l’environnement des soins

Bacground

Stenotrophomonas maltophilia (Smalto) is a prominent nosocomial pathogen, commonly isolated in the hospital environment. Multiple Smalto nosocomial outbreaks have been linked to contaminated water sources. This study aimed to develop a medium able to ease healthcare environment Smalto isolation.

Methods

Financed, from March 2007 to June 2008, by a university hospital of Amiens’ clinical research program, this study allowed Stenotrophomonas maltophilia selective medium with coloured indicator (SM2i) development. SM2i is constituted of Mueller Hinton agar (MH), maltose, DL-methionine, bromothymol blue. The mixture sterilized is refreshed at 50 °C, its pH adjusted to 7.1, and render selective by addition of vancomycin, imipenem and amphotericin B. Then, SM2i agar is sunk into 90 cm diameter Petri dish dated and stored at 4 °C for 4 weeks. SM2i is developed using Pasteur Institute culture type collection (CIP) strains of Smalto, Burkholderia cepacia, Pseudomonas aeruginosa (Psa) and a Smalto strain of our hygiene laboratory collection. It was validate on Psa imipenem-resistant and Enterococcus faecium vancomycin-resistant strains, then, tested on cold water first jet and faucet cotton-swabs samples. SM2i tests were made in comparison with the MH agar, MH agar plus four paper disks loaded 10 μg of imipenem and Cetrimed agar. Its sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, accuracy, likehood-ratio (LR) and Youden index have been determined.

Results

SM2i agar is better in culturing Smalto test-strains. On SM2i, Smalto colonies are smooth, round, greeny, olive or lime green, have a green olive centre with a peripheral lighter or a dark green centre with an olive green suburb surrounded by a blue halo. SM2i is a selective, specific, predictive, accurate medium to search for Smalto in healthcare environment. In 122 pairs of cold water first jet and taps cotton-swabs samples, Smalto was isolated from 14.8% of water samples, 10.7% of cotton-swabs samples. It was isolated alone in 6.6% of water samples and 2.5% of swab samples. Thus, smalto has biocontaminated 17.2% of cold water taps. Compared to MH agar, SM2i sensitivity, specificity, PPV, NPV, accuracy, LR were 100, 100, 100, 100, 100% and ∞, and 87.5, 100, 100, 98.1, 98.4% and ∞ for water and cotton-swabs samples respectively.

Conclusion

SM2i is a selective, specific, predictive medium which can allow easily isolating and identifying accurately Smalto in environmental samples. Its evaluation on clinical samples is on going.     

Caractérisation phénotypique et génotypique (randomly amplified polymorphic DNA analysis et multiple-locus variable-number tandem-repeat analysis) de 96 isolats cliniques de Pseudomonas aeruginosa à l’hôpital F. Bourguiba (Monastir,Tunisie)

Aim of the study

Phenotypic and genotypic characterization of 96 clinical isolates of Pseudomonas aeruginosa recovered in a Tunisian teaching hospital during a 16-month period.

Materials and methods

All the isolates were characterized by serotyping, antimicrobial susceptibility typing and genotyping with randomly amplified polymorphic DNA (RAPD) analysis and multiple-locus variable-number tandem-repeat analysis (MLVA).

Results

Forty-one isolates out of 96 (43%) were recovered from two intensive care units (medical and chirurgical). Most of the isolates (48%) belonged to serotype O:11. Among the 13 antibiotypes, three multidrug resistant ones were mostly observed within the two intensive care units. Genotyping showed 83 RAPD types and 52 MLVA types. Isolates showing the same serotype could show different genotypes. A limited number of clusters was highlighted with MLVA typing, of which an outbreak of nine cases within the surgical intensive care unit.

Conclusion

Except this outbreak of nine cases, the heterogeneity observed for most of the P. aeruginosa isolates showed that outbreak situations were rare in the F. Bourguiba hospital during the study period. MLVA genotyping is a good tool for genotyping P. aeruginosa clinical isolates.     

Portage digestif d’entérobactéries résistantes aux céphalosporines de troisième génération dans une population d’adultes jeunes asymptomatiques : évolution entre 1999 et 2009

Objectives

The aim of this work was to evaluate the fecal carriage of third generation cephalosporins resistant Enterobacteriaceae in nonhospitalized asymptomatic young adults.

Methods

A total of 517 normal fecal samples were spread onto plates agar containing cefotaxime. Isolated strains were identified and studied with agar disk diffusion antibiogram, minimal inhibition concentration in liquid medium and phenotypic and molecular study. Data were compared with a previous study realised in the same conditions in 1999.

Results

In 2009, the prevalence of cefotaxime resistant enterobacteria was 4.2%. Of these 22 Enterobacteriaceae, 11 harboured overexpressed cephalosporinase and 11 produced extended-spectrum-betalactamase (ESBL). Among ESBL, six E. coli produced CTX-M from group 1 (n = 6), group 2 (n = 1), group 9 (n = 2), one E. coli produced SHV-12 and one Klebsiella pneumoniae produced CTX-M from group 1. All ESBL were multiresistant. In 1999, all the CTX resistant isolates recovered produced a cephalosporinase and no ESBL was found.

Conclusions

This study highlights the increasing prevalence of fecal carriage of ESBL-producing enterobacteria in asymptomatic young patients in the community (0% in 1999 versus 2.1% in 2009; P < 0.001). E. Coli with CTX-M from group 1 was the most frequent ESBL identified, while fecal carriage of Enterobacteteriaceae overproducing cephalosporinase was similar (2.1%).     

Observatoire régional du pneumocoque en région Pays de la Loire : résistance de Streptococcus pneumoniae aux antibiotiques en 2007

Objectives

Between 1st January and 31st December 2007, 331 Streptococcus pneumoniae strains were collected from 20 participating laboratories in the Pneumococcus Network Pays de la Loire county to assess their susceptibility to antibiotics and to evaluate serogroups of strains.

Method

The coordinating centre performed MICs of penicillin G, amoxicillin and cefotaxime by the reference agar dilution method. Results were interpreted according to CA-SFM breakpoints. Sensitivity to other antibiotics were studied and serotyping of each strain performed.

Results

Three hundred and thirty one strains were isolated in 2007. They were collected from 30 cerebrospinal fluids, 239 blood samples, 53 middle ear fluids and nine pleural fluids. The percentage of pneumococci with decreased susceptibility to penicillin G (PDSP) was 39% and was higher in children (51%) than in adults (35%). The PDSP were often multidrug resistants especially with a high percentage of resistance to erythromycin (87.6% versus 8.4% for pneumococci sensitive to penicillin G). Finally, the most prevalent serogroup was the serogroup 19 (29.6% of isolates).

Conclusion

A decrease of PDSP was observed since 2001 and high-level resistant strains to β-lactams remain low. The rate of PDSP in Pays de la Loire is in the national average.     

Analyse immunoprotéomique comparative des sécrétomes de souches de Staphylococcus aureus et S. epidermidis chez les patients souffrant d’infections sur prothèses articulaires

Aim of the study

Staphylocci such as Staphylococcus aureus and S. epidermidis are the most frequently pathogens associated to prosthesis joint infections (PJI), counting for 75% among the isolated bacteria. In this study, we identified PJI-related antigens using two-dimensional immunoblots of S. aureus and S. epidermidis exoproteins probed with serum samples from patients with confirmed PJIs. We further analysed by ELISA tests the response of patients to the identified proteins.

Patients and methods

Secreted proteins from Mu50 strain (S. aureus) and RP62A strain (S. epidermidis) were separated by 2D gel electrophoresis and analyzed by western blot with serum samples from patients with confirmed S. aureus and S. epidermidis PJIs. Recombinant proteins corresponding to the identified proteins were expressed and screened with an in-house ELISA to evaluate their interest for the diagnosis of S. aureus and S. epidermidis PJIs.

Results

Fifty-two antigenic exoproteins were identified: 42 belonging to Mu50 strain, and 10 to RP62A strain. Twenty-two proteins were identified as S. aureus specific. Among these proteins, five were most frequently recognized by patients with S. aureus PJI.

Conclusion

Our results showed that few exoproteins were antigenic by RP62A strain compared to Mu50 strain. We identified five antigenic and S. aureus specific proteins, which may contribute to diagnosis, prevention and treatment of these infections.     

Identification bactérienne par spectrométrie de masse de type MALDI-TOF : évaluation au CHU de Lille

Purpose

The aim of our study was to evaluate the capacity of MALDI-TOF mass spectrometry to identify clinical bacterial isolates, as compared to the automated identification system Vitek 2 (bioMérieux) used routinely in a teaching hospital.

Methods

Three hundred and sixty-two strains representing 178 species from the laboratory collection were analysed by a Microflex spectrometer (Bruker Daltonics) and Vitek 2. Discrepancies between MALDI-TOF and Vitek 2 identifications were investigated by genetic identification (rrS, sodA, rpoB), considered as a reference.

Results

Among the 362 isolates, 264 (73%) were consistently identified by Vitek 2 and Microflex. Taking into account genetic identification, we found that 44 (44.9%) of the 98 remaining isolates were correctly identified by mass spectrometry but not by Vitek 2. Conversely, 33 isolates (33.7%) were correctly identified by Vitek 2, but not by Microflex. The genetic identification of the 21 remaining isolates (21,4%) did not match either Vitek 2 or Microflex results.

Conclusion

The performances of MALDI-TOF mass spectrometry for bacterial identification correspond to those of a reference automated identification system.     

Méningo-encéphalite à Bartonella quintana chez un sujet immunocompétent : une observation rare

Introduction

Bartonella quintana (Bq) is responsible of various clinical pictures. Neuromeningeal complications are rarely reported.

Case

A 20-year-old woman was admitted for fever, headache lasting for 5 days. On admission, she was febrile at 39.3 °C and had a stiff neck. Symptoms, contact with animals, biological tests and lumbar puncture (PL) rendered viral meningitis a likely diagnosis. She had received symptomatic treatment and the outcome was favorable. Three days later, the patient had headache, agitation and confusion with fever. The PL noted 130/mm³ whites, 90% lymphocytes. The albuminorachie was 0.98 g/L, glucorachie was normal. The patient was treated with 400 mg of ofloxacine/day, seven days. Serologic tests for B. quintana were reactive. The outcome was favorable.

Conclusion

B. quintana infection should be considered in neurological symptoms of unknown etiology.     

Panic disorder and serotonergic genes (SLC6A4, HTR1A and HTR2A): Association and interaction with childhood trauma and parenting

Objective

The aim of this study is to evaluate the association between HTR1A, HTR2A and the 5-HTTLPR in panic disorder (PD) patients and controls. In addition, this study also aims to evaluate the interaction between these genes and two environmental factors previously associated with PD: childhood trauma and parental bonding.

Methods

This is a case–control candidate gene association study (107 PD patients and 125 controls). Genes were analyzed using a gene-based test in PLINK followed by single marker association tests and haplotype test only for genes that reached experiment-wide significance in the gene-based test in order to minimize multiple testing. Logistic regression was used to test the relationships between genotype in the additive model, trauma, optimal paternal parenting and optimal maternal parenting and their interactions.

Results

Only HTR1A was associated with PD in gene-based test after correction for multiple tests (p_corrected = 0.027) and one HTR1A haplotype comprising four SNPs was associated with PD (p_corrected = 0.032). In the interaction analysis, no significant gene–environment interaction was found with the genes evaluated.

Conclusion

This study reinforces the association between HTR1A and PD. No major evidence of gene–environment interaction in PD with parenting or trauma was found. Further studies are necessary in order to confirm these findings.     

Le dépistage en ambulatoire des patients porteurs de Staphylococcus aureus ou présentant une colonisation urinaire et devant bénéficier d’une chirurgie orthopédique est-il réaliste ?

Aim of the study

Evaluate the feasibility of Staphylococcus aureus nasal colonization and bacteriuria screening in outpatients before realizing a decolonization treatment in S. aureus carriers and a bacteriuria treatment before hospitalization.

Méthods

All patients undergoing hip, knee or back surgery in which prosthesis were implanted between October 2007 until the end of June 2008 were included. Microbiological studies were performed before hospitalization. Notice for S. aureus decolonization regimen was delivered to each patient and to the general practitioner only if the patient had nasal carriage.

Results

Only 91.2 % (240/263) of patients had microbiological results. Prevalence of S. aureus colonization was 21.4 % (48 positives/224). Three patients were colonized with methicillin-resistant staphylococci. Decolonization regimen was applied before surgery to 70.8 % (n = 34) of the colonized patients. Among the patients, 8.9 % (20/225) had bacteriuria, Escherichia coli being the most frequent micro-organism (n = 16).

Conclusion

Preoperative search and management of S. aureus colonization and of bacteriuria in outpatients is possible. Monitoring record must be performed by a member of the hospital staff.