A Deplano

Publications of A Deplano

• Previous healthcare exposure is the main antecedent for methicillin-resistant Staphylococcus aureus carriage on hospital admission in Belgium.

  Authors: S Vandendriessche, M Hallin, B Catry, B Jans, A Deplano, C Nonhoff, S Roisin, R De Mendonça, M J Struelens, O Denis

  European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 03/2012;

  This study aimed to estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage upon hospital admission and to study the molecular epidemiology of MRSA in order to assessThis study aimed to estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage upon hospital admission and to study the molecular epidemiology of MRSA in order to assess the proportion of Panton-Valentine leukocidin (PVL)-positive community-associated (CA) and livestock-associated (LA) MRSA strains. Epidemiological data on MRSA carriage upon hospital admission (2006-2009) were collected in a compulsory, continuous, national MRSA surveillance in Belgian acute-care hospitals. Additionally, 328 MRSA strains in 2005 and 314 strains in 2008 were collected in a separate, multicenter microbiological survey. Spa-typing, SCCmec-typing and MLST were performed; toxin genes were detected by PCR. The overall prevalence of MRSA carriage upon hospital admission was 8.9 cases/1,000 admissions between 2006 and 2009. Of MRSA carriers, 37.5% had a known MRSA history, 39.4% had stayed in a care facility, 12.2% reported no contact with healthcare. Over 90% of MRSA belonged to five healthcare-associated clones. Of these, MRSA spa-CC038-ST45-IV was in decline, mainly in favor of spa-CC008-ST8-IV. MRSA spa-CC002-ST5-IV, spa-CC002-ST5-II and spa-CC032-ST22-IV remained relatively stable. The proportion of PVL-positive CA-MRSA and LA-MRSA ST398 was below 2% of all MRSA. The extra-hospital MRSA reservoir in Belgium mainly consists of persons with previous healthcare exposure. PVL-positive CA-MRSA and LA-MRSA strains remained infrequent among hospitalized patients.

• Pseudo-Outbreak of Extremely Drug-Resistant Pseudomonas aeruginosa Urinary Tract Infections Due to Contamination of an Automated Urine Analyzer.

  Authors: M Hallin, A Deplano, S Roisin, V Boyart, R De Ryck, C Nonhoff, B Byl, Y Glupczynski, O Denis

  Journal of clinical microbiology. 01/2012; 50(3):580-2.

  By the end of May 2010, an increase in the number of urine specimens that were culture positive for extremely drug-resistant (XDR) Pseudomonas aeruginosa was observed in our 800-bed universityBy the end of May 2010, an increase in the number of urine specimens that were culture positive for extremely drug-resistant (XDR) Pseudomonas aeruginosa was observed in our 800-bed university hospital. This led to an infection control alert. No epidemiological link between the patients and no increase in the frequency of XDR P. aeruginosa in non-urine samples were observed. Therefore, a pseudo-outbreak due to analytical contamination in the laboratory was rapidly suspected. A prospective and retrospective search of cases was initiated, and the sampling of the automated urine analyzers used in the laboratory was performed. Antibiotypes were determined by disc diffusion, and genotypes were determined by pulsed-field gel electrophoresis (PFGE). From February to July 2010, 17 patients admitted to 12 different departments and 6 outpatients were included. The mixing device of the cytometric analyzer used for the numeration of urinary particles (Sysmex UF1000i) proved to be heavily contaminated. Isolates recovered from 12 patients belonged to the same antibiotype and PFGE type as the isolate recovered from the analyzer. Extensive disinfection with a broad-spectrum disinfectant and the replacement of the entire tubing was necessary to achieve the complete negativity of culture samples taken from the analyzer. A pseudo-outbreak caused by an XDR P. aeruginosa clone was proven to be due to the contamination of the cytometric analyzer for urinary sediment. Users of such analyzers should be aware that contamination can occur and should always perform culture either before the processing of the urine sample on the analyzer or on a distinct sample tube.

• Detection of a VIM-27-producing Klebsiella pneumoniae isolate in a patient following surgical tourism in Greece.

  Authors: P Bogaerts, R Rezende de Castro, A Deplano, W Bouchahrouf, C Tsobo, O Denis, Y Glupczynski

  Antimicrobial agents and chemotherapy. 09/2011; 55(9):4488-9.

• Positive predictive value of the Xpert MRSA assay diagnostic for universal patient screening at hospital admission: influence of the local ecology.

  Authors: S Roisin, C Laurent, C Nonhoff, A Deplano, M Hallin, B Byl, M J Struelens, O Denis

  European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 08/2011;

  The purpose of this study was to assess the accuracy of the Xpert MRSA assay (XP) for the detection of methicillin-resistant Staphylococcus aureus (MRSA) carriage upon hospital admission. Nasal swabsThe purpose of this study was to assess the accuracy of the Xpert MRSA assay (XP) for the detection of methicillin-resistant Staphylococcus aureus (MRSA) carriage upon hospital admission. Nasal swabs were prospectively collected for MRSA screening from 1,891 patients admitted to a teaching hospital. XP results were compared to chromogenic agar culture results. MRSA was cultured in 61 specimens (3%). Compared with culture, XP had a sensitivity, specificity, positive, and negative predictive value of 60.7, 97.3, 37.8, and 98.9%, respectively. The median turnaround time (TAT) for the results was 3 h. Of 24 MRSA isolated from XP-negative samples, three harbored composite SCCmec. Among 61 samples with culture-negative but XP-positive results, 15 methicillin-susceptible S. aureus (MSSA) isolates tested positive by XP on pure colony lysates. These MSSA included: (i) strains with SCCmec deletion encompassing mecA and (ii) multilocus sequence typing (MLST) clonal complex (CC) 1 strains harboring a chromosomal sequence homologous to one of the orfX-SCCmec junction sequences targeted by XP. On account of the low sensitivity and positive predictive value in a hospital patient population with moderate prevalence of MRSA, culture still appears to be necessary in order to confirm polymerase chain reaction (PCR) results. The emergence of new SCCmec variants and the presence of MSSA harboring cross-reactive SCCmec-like elements may challenge the successful implementation of such detection systems.

• Heterogeneity of disease and clones of community-onset methicillin-resistant Staphylococcus aureus in children attending a paediatric hospital in Belgium.

  Authors: A Vergison, A Nobre Machado, A Deplano, M Doyen, J Brauner, C Nonhoff, R de Mendonça, G Mascart, O Denis

  Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 07/2011;

  Clin Microbiol Infect ABSTRACT: The increase in the number of methicillin-resistant Staphylococcus aureus (MRSA) infections in children has prompted paediatricians to broaden th empirical treatmentClin Microbiol Infect ABSTRACT: The increase in the number of methicillin-resistant Staphylococcus aureus (MRSA) infections in children has prompted paediatricians to broaden th empirical treatment of common community-onset (CO) infections in children in several countries. Most European countries have reported low rates of CO-MRSA infection, but limited data on paediatric CO-MRSA infections are available. A prospective study was conducted from January 2002 to December 2004 in Brussels. CO-MRSA was defined as MRSA first detected by culture within 48 h of admission or in outpatients. Clinical and epidemiological data were recorded. CO-MRSA strains were genotyped by pulsed-field gel electrophoresis and multilocus sequence typing. Staphylococcal chromosomal cassette mec, toxin (Panton-Valentin leukocidin (PVL), toxic shock syndrome toxin 1, and Eta/b), enterotoxin and antibiotic resistance genes were detected by PCR. The antibiotic resistance phenotype was determined by disk diffusion. S. aureus was isolated in 1681 children. Among these, 107 harboured MRSA. Fifty-one children were colonized or infected by CO-MRSA, 20% of whom had no healthcare exposure. Twelve infants <3 months old and five cystic fibrosis patients were colonized. None of the 22 infected patients (59% with acute otitis media and 36% with skin and soft tissue infections (SSTIs)) required hospitalization. Two-thirds of them failed to respond to empirical antibiotic therapy. The 37 characterized CO-MRSA strains were genetically diverse. Most of them had healthcare-associated genotypes. Only six strains were PVL-positive, all of which were ciprofloxacin-susceptible and more common in children with SSTIs (p 0.001). CO-MRSA remains uncommon in our paediatric population. So far, there is no need to modify the empirical treatment of common S. aureus infections. Monitoring of MRSA rates in S. aureus CO infections remains mandatory, and further investigation is warranted to establish the source of colonization in young infants.

• Rapid emergence of carbapenemase-producing Enterobacteriaceae isolates in Belgium.

  Authors: T D Huang, P Bogaerts, C Berhin, B Jans, A Deplano, O Denis, Y Glupczynski

  Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin. 01/2011; 16(26).

• Trends in production of extended-spectrum beta-lactamases among Enterobacteriaceae of clinical interest: results of a nationwide survey in Belgian hospitals.

  Authors: H Rodriguez-Villalobos, P Bogaerts, C Berhin, C Bauraing, A Deplano, I Montesinos, R de Mendonça, B Jans, Y Glupczynski

  The Journal of antimicrobial chemotherapy. 10/2010; 66(1):37-47.

  to assess the frequency and diversity of extended-spectrum β-lactamases (ESBLs) in Enterobacteriaceae isolates in Belgium. during 2006 and 2008, non-duplicate clinical isolates of Enterobacteriaceaeto assess the frequency and diversity of extended-spectrum β-lactamases (ESBLs) in Enterobacteriaceae isolates in Belgium. during 2006 and 2008, non-duplicate clinical isolates of Enterobacteriaceae resistant to ceftazidime and/or cefotaxime were collected in 100 Belgian hospitals. ESBL production was confirmed by phenotypic and genotypic tests. MICs of 13 antimicrobial agents were determined by Etest. ESBL-encoding genes were identified by PCR sequencing and the bla(CTX-M) environment was characterized by PCR mapping. Selected isolates were genotyped by PFGE, multilocus sequence typing analysis and phylogenetic grouping by PCR. overall, 733 isolates were confirmed as ESBL producers. Carbapenems and temocillin were active against ≥ 95% of all tested isolates. Co-resistance to co-trimoxazole and to ciprofloxacin was found in almost 70% and 80% of the strains, respectively. Overall, Escherichia coli (49%), Enterobacter aerogenes (32%) and Klebsiella pneumoniae (9%) represented the most prevalent species. Isolates harboured predominantly TEM-24 (30.7%), CTX-M-15 (24.2%) and TEM-52 (12.1%). Compared with 2006, the proportion of CTX-M-type enzymes increased significantly in 2008 (54% versus 23%; P < 10(-6)), mostly linked to a rising proportion of CTX-M-15-producing E. coli. TEM-24 decreased (19% in 2008 versus 43% in 2006; P < 10(-6)) during the same period, while the prevalence of TEM-52 remained unchanged (10% in 2008 versus 14% in 2006; not significant). Over 80% of the CTX-M-15-producing E. coli isolates clustered into a single PFGE type and phylogroup B2, corresponding to the sequence type (ST) 131 clone. Intra- and inter-species gene dissemination (CTX-M-15, CTX-M-2 and CTX-M-9) and wide epidemic spread of the CTX-M-15-producing E. coli ST131 clone in several Belgian hospitals were observed. the rapid emergence of multiresistant CTX-M-15-producing E. coli isolates is of major concern and highlights the need for further surveillance in Belgium.

• Evaluation of the Xpert MRSA assay for rapid detection of methicillin-resistant Staphylococcus aureus from nares swabs of geriatric hospitalized patients and failure to detect a specific SCCmec type IV variant.

  Authors: C Laurent, P Bogaerts, D Schoevaerdts, O Denis, A Deplano, C Swine, M J Struelens, Y Glupczynski

  European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 08/2010; 29(8):995-1002.

  Rapid and reliable detection of methicillin-resistant Staphylococcus aureus (MRSA) carriers is crucial for control of MRSA nosocomial transmission. We aimed to evaluate the performance of theRapid and reliable detection of methicillin-resistant Staphylococcus aureus (MRSA) carriers is crucial for control of MRSA nosocomial transmission. We aimed to evaluate the performance of the GeneXpert real-time PCR system using the Xpert MRSA assay on a collection of 40 representative Belgian MRSA strains and for MRSA screening of geriatric inpatients. Double nasal swabs were used: the first swab for the Xpert MRSA assay and the second for culture onto chromogenic selective medium and enrichment broth. All but 1 of the 40 collection strains were recognized as MRSA by the Xpert MRSA assay. Nares swabs were prospectively collected from 246 inpatients including 25 nasal MRSA carriers. Compared with enriched cultures, the sensitivity, the specificity, and the positive and negative predictive values of the Xpert MRSA assay were 69.2%, 97.7%, 78.3%, and 96.3% respectively. The 7 evaluable false-negative results according to the assay were due to its possible lack of sensitivity (n = 3) and to the occurrence of a Belgian MRSA clone carrying a particular staphylococcal chromosomal cassette mec (SCCmec) type IV variant (n = 4) not targeted by the current Xpert MRSA assay. Because of the evolution of SCCmec in MRSA, new primers should be designed and further studies are warranted to ensure continuous monitoring of this assay.

• Detection and characterization of class A extended-spectrum-beta-lactamase-producing Pseudomonas aeruginosa isolates in Belgian hospitals.

  Authors: Y Glupczynski, P Bogaerts, A Deplano, C Berhin, T-D Huang, J Van Eldere, H Rodriguez-Villalobos

  The Journal of antimicrobial chemotherapy. 03/2010; 65(5):866-71.

  To investigate the presence of extended-spectrum beta-lactamases (ESBLs) among Pseudomonas aeruginosa clinical isolates referred to two Belgian reference laboratories. Antibiograms were analysed forTo investigate the presence of extended-spectrum beta-lactamases (ESBLs) among Pseudomonas aeruginosa clinical isolates referred to two Belgian reference laboratories. Antibiograms were analysed for P. aeruginosa isolates referred between 2004 and 2008. Isolates resistant to ceftazidime (MIC > 8 mg/L) and with a positive double-disc synergy test between ceftazidime and clavulanate were serotyped and screened for the presence of ESBL-encoding genes. Genes encoding metallo-beta-lactamases (bla(MBL)) were sought by PCR in ESBL-producing isolates with positive imipenem/EDTA synergy tests. PFGE of SpeI-digested genomic DNA was used to compare isolates and selected strains were characterized by multilocus sequence typing. Forty-eight (2.2%) of 2150 P. aeruginosa isolates were confirmed as class A ESBL-producing isolates by molecular testing. bla(BEL) and bla(PER) alleles were detected, respectively, in 39 and 10 P. aeruginosa isolates originating from 16 hospitals (two isolates were simultaneously positive for BEL and PER). Fifteen of the isolates were found to co-produce ESBLs and VIM carbapenemases. These strains were pan-resistant and remained susceptible only to colistin (MICs <or= 2 mg/L). The majority of the ESBL-producing isolates belonged to the same PFGE clone and were identified as ST235; serotype O11. BEL enzymes were produced by 80% of P. aeruginosa isolates with phenotypic evidence of ESBL production. BEL or PER ESBLs co-existed with VIM carbapenemases in 15 isolates and caused outbreaks in four hospitals. Our data further highlight the epidemic potential of the international clone ST235, which may have acquired bla(BEL-1) gene cassettes from a yet unidentified local gene reservoir.

• Emergence of clonally related Klebsiella pneumoniae isolates of sequence type 258 producing KPC-2 carbapenemase in Belgium.

  Authors: P Bogaerts, I Montesinos, H Rodriguez-Villalobos, L Blairon, A Deplano, Y Glupczynski

  The Journal of antimicrobial chemotherapy. 12/2009;

• Molecular characterization of AmpC-producing Escherichia coli clinical isolates recovered at two Belgian hospitals.

  Authors: P Bogaerts, H Rodriguez-Villalobos, C Bauraing, A Deplano, C Laurent, C Berhin, M J Struelens, Y Glupczynski

  Pathologie-biologie. 11/2009;

  OBJECTIVE: To characterize the genetic determinants associated with an AmpC phenotype in clinical Escherichia coli isolates. METHODS: E. coli strains recovered at two Belgian hospitals between 2004OBJECTIVE: To characterize the genetic determinants associated with an AmpC phenotype in clinical Escherichia coli isolates. METHODS: E. coli strains recovered at two Belgian hospitals between 2004 and 2006 were selected on the basis of an AmpC-producing phenotype. Plasmid-mediated cephalosporinases coding genes and the sequence of chromosomal ampC genes were identified by PCR/sequencing. The isolates were submitted to phylotyping and genotyping analysis using rep-PCR (Diversilab) and PFGE. A novel chromosomal ampC gene was cloned. RESULTS: Eighty-three out of 6850 E. coli isolates were selected. Seventy-two isolates were found to overexpress their chromosomal cephalosporinases while 11 contained plasmid-mediated cephalosporinases. Among chromosomal AmpC overproducers, 12 were extended-spectrum AmpC (ESAC) expressing isolates which all displayed reduced susceptibility to cefepime. Cloning of a new ESAC allele suggested that L293P mutation was responsible of the extension of the hydrolysis spectrum to cefepime. AmpC overproducers, including ESAC producers, predominantly belonged to phylogenetic group A and B1, while plasmid-mediated AmpC-producing isolates preferentially belong to phylogroup B2 and D. According to rep-PCR, the majority of the E. coli isolates belonging to phylogroup A were clonally related which was further confirmed by PFGE for the 11 ESAC expressing isolates. CONCLUSIONS: Chromosomal AmpC overproduction was the most common resistance mechanism, and the occurrence of ESAC was found to be as frequent as plasmid-mediated cephalosporinases. The detection of a new ESAC allele, of an ESAC producing strain belonging to phylogroup D and the existence of a clonal relationship between ESAC producing strains underline the need for study of the clinical relevance of this mechanism of resistance.

• Evolutionary relationships between sporadic and epidemic strains of healthcare-associated methicillin-resistant Staphylococcus aureus.

  Authors: M Hallin, O Denis, A Deplano, R De Ryck, S Crèvecoeur, S Rottiers, R De Mendonça, M J Struelens

  Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 08/2008; 14(7):659-69.

  National surveillance of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) isolates by pulsed-field gel electrophoresis (PFGE) typing allowed identification of rarelyNational surveillance of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) isolates by pulsed-field gel electrophoresis (PFGE) typing allowed identification of rarely occurring 'sporadic' isolates with patterns significantly distinct from those of major epidemic clones of methicillin-resistant S. aureus (MRSA) circulating in Belgian hospitals. The aim of the present study was to compare the genetic background, antibiotic susceptibility profile and in vitro growth rates of 36 MRSA isolates with either 'epidemic' or 'sporadic' PFGE profiles to identify factors that could be involved in the epidemic behaviour of S. aureus. Sequence analysis of seven housekeeping genes (multilocus sequence typing) and seven surface-associated genes, combined with staphylococcal cassette chromosome mec (SCCmec) typing and spa typing results, segregated sporadic isolates into four groups: (1) isolates phylogenetically distant from epidemic HA-MRSA clones that possessed several properties of community-acquired MRSA strains; (2) isolates derived from the same methicillin-susceptible S. aureus ancestor as epidemic isolates but possessing a distinct type of SCCmec; and (3) and (4) isolates that were closely related to epidemic strains, either as recent descendants of these or as intermediate evolutionary steps between epidemic HA-MRSA strains and their putative ancestors. Sporadic isolates did not show slower growth in vitro than epidemic isolates. These findings suggest that the SCCmec type and insertion/deletion of other mobile genetic elements may be involved in modulating the epidemic behaviour of MRSA strains of similar genetic background, independently of fitness cost.

• High occurrence of methicillin-resistant Staphylococcus aureus ST398 in equine nasal samples.

  Authors: A Van den Eede, A Martens, U Lipinska, M Struelens, A Deplano, O Denis, F Haesebrouck, F Gasthuys, K Hermans

  Veterinary microbiology. 08/2008;

  Methicillin-resistant Staphylococcus aureus (MRSA) infections do occur in equine patients. Little is known, however, about their origin and the general equine MRSA colonization status. In WestMethicillin-resistant Staphylococcus aureus (MRSA) infections do occur in equine patients. Little is known, however, about their origin and the general equine MRSA colonization status. In West European horses in particular, neither the colonization rate nor the present strains or their antimicrobial susceptibility patterns are known. In the present study, a sample of 110 (Belgian, French, Dutch and Luxemburg) horses presented at a Belgian equine clinic was screened for nasal MRSA carriage. An indirect culturing protocol using a 0.001% colistin and nalidixic acid containing broth was compared to a direct agar method. Phenotypic identification following growth on a chromogenic MRSA screening agar (ChromIDtrade mark MRSA) was combined with genotypic analysis (PCR, PFGE, SCCmec, spa, and MLST typing). Antimicrobial susceptibility was tested through disk diffusion. Twelve (10.9%) horses carried MRSA, with the enrichment protocol resulting in a significantly higher isolation rate. None of the isolated strains were typeable through SmaI PFGE. They all harboured SCCmec type IVa or V and belonged to spa type t011 or t1451 of the ST398 lineage. All isolates were tetracycline resistant and sulfonamide and enrofloxacin susceptible. Macrolide, lincosamide, trimethoprim and aminoglycoside susceptibility varied and in total five different antimicrobial resistance patterns were distinguished. These results show that ST398 is certainly present in West European horses. Due to its known interspecies transmission and the structure of the equine industry, the presence of this clone in horses poses a substantial health hazard for both animals and humans.

• Intensive care unit outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae controlled by cohorting patients and reinforcing infection control measures.

  Authors: C Laurent, H Rodriguez-Villalobos, F Rost, H Strale, J L Vincent, A Deplano, M J Struelens, B Byl

  Infection control and hospital epidemiology : the official journal of the Society of Hospital Epidemiologists of America. 07/2008; 29(6):517-24.

  OBJECTIVE: To describe an outbreak of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in the intensive care units (ICUs) of a hospital and the impact of routine and reinforcedOBJECTIVE: To describe an outbreak of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in the intensive care units (ICUs) of a hospital and the impact of routine and reinforced infection control measures on interrupting nosocomial transmission. DESIGN: Outbreak report. SETTING: A 31-bed intensive care department (composed of 4 ICUs) in a university hospital in Belgium. INTERVENTION: After routine infection control measures (based on biweekly surveillance cultures and contact precautions) failed to interrupt a 2-month outbreak of ESBL-producing K. pneumoniae, reinforced infection control measures were implemented. The frequency of surveillance cultures was increased to daily sampling. Colonized patients were moved to a dedicated 6-bed ICU, where they received cohorted care with the support of additional nurses. Two beds were closed to new admissions in the intensive care department. Meetings between the ICU and infection control teams were held every day. Postdischarge disinfection of rooms was enforced. Broad-spectrum antibiotic use was discouraged. RESULTS: Compared with a baseline rate of 0.44 cases per 1,000 patient-days for nosocomial transmission, the incidence peaked at 11.57 cases per 1,000 patient-days (October and November 2005; rate ratio for peak vs baseline, 25.46). The outbreak involved 30 patients, of whom 9 developed an infection. Bacterial genotyping disclosed that the outbreak was polyclonal, with 1 predominant genotype. Reinforced infection control measures lasted for 50 days. After the implementation of these measures, the incidence fell to 0.08 cases per 1,000 patient-days (rate ratio for after the outbreak vs during the outbreak, 0.11). CONCLUSION: These data indicate that, in an intensive care department in which routine screening and contact precautions failed to prevent and interrupt an outbreak of ESBL-producing K. pneumoniae, reinforced infection control measures controlled the outbreak without major disruption of medical care.

• Outbreak of hospital-adapted clonal complex-17 vancomycin-resistant Enterococcus faecium strain in a haematology unit: role of rapid typing for early control.

  Authors: A Deplano, O Denis, C Nonhoff, F Rost, B Byl, F Jacobs, V Vankerckhoven, H Goossens, M J Struelens

  The Journal of antimicrobial chemotherapy. 11/2007; 60(4):849-54.

  OBJECTIVES: To describe the investigation and molecular characterization of a vancomycin-resistant Enterococcus faecium (VREF) strain responsible for a nosocomial outbreak in the haematology unit ofOBJECTIVES: To describe the investigation and molecular characterization of a vancomycin-resistant Enterococcus faecium (VREF) strain responsible for a nosocomial outbreak in the haematology unit of a tertiary-care university hospital. PATIENTS AND METHODS: Two patients admitted to the haematology unit developed infection/colonization with VREF over a 3 month period when compared with none in the 2 previous years. On the basis of the identification of a clonal link between these two strains, weekly rectal screening was implemented for all patients in the haematology unit and contact precautions were extended to VREF carriers. In the following 6 month period, 11 patients colonized with VREF were detected. No further case was detected in the following 1 year period. RESULTS: VREF isolates from the haematology unit carried the vanA gene and were multiresistant to antimicrobial agents, including high-level resistance to vancomycin, teicoplanin and ampicillin. This resistance profile restricted the choice of antimicrobial therapy to linezolid or investigational drugs such as tigecycline. Molecular analysis showed that 11 of 13 (85%) VREF isolates belonged to pandemic clonal complex-17 carrying the esp and hyl virulence genes. CONCLUSIONS: Rapid typing and infection control measures, including early reinforcement of barrier precautions combined with weekly rectal surveillance cultures, were followed by control of nosocomial spread of this VREF clone.

• National survey of molecular epidemiology of Staphylococcus aureus colonization in Belgian cystic fibrosis patients.

  Authors: A Vergison, O Denis, A Deplano, G Casimir, G Claeys, F DeBaets, K DeBoeck, N Douat, H Franckx, J Gigi, M Ieven, C Knoop, P Lebeque, F Lebrun, A Malfroot, F Paucquay, D Pierard, J Van Eldere, M J Struelens

  The Journal of antimicrobial chemotherapy. 06/2007; 59(5):893-9.

  OBJECTIVES: Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is poorly defined in cystic fibrosis (CF) patients, and S. aureus detection may be hampered by the presence of smallOBJECTIVES: Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is poorly defined in cystic fibrosis (CF) patients, and S. aureus detection may be hampered by the presence of small colony variants (SCVs). We conducted a multicentre survey to determine the prevalence of S. aureus and MRSA colonization in Belgian CF patients and characterize the phenotype and clonal distribution of their staphylococcal strains. METHODS: S. aureus isolated from CF patients attending nine CF centres were collected. Oxacillin resistance was detected by oxacillin agar screen and mecA PCR. Antibiotic susceptibility was tested by microdilution. MRSA strains were genotyped by PFGE and SCCmec typing and compared with hospital-associated MRSA strains. RESULTS: Laboratories used a diversity of sputum culture procedures, many of which appeared substandard. S. aureus was isolated from 275/627 (44%) CF patients (20% to 72% by centre). The prevalence of SCV colonization was 4%, but SCVs were almost exclusively recovered from patients in two centres performing an SCV search. Phenotypically, 14% of S. aureus isolates were oxacillin-resistant: 79% carried mecA and 19% were SCVs lacking mecA. The mean prevalence of 'true' MRSA colonization was 5% (0% to 17% by centre). By PFGE typing, 67% of CF-associated MRSA were related to five epidemic clones widespread in Belgian hospitals. CONCLUSIONS: This first survey of S. aureus colonization in the Belgian CF population indicated a diversity in local prevalence rates and in proportion of oxacillin-resistant and SCV phenotypes, probably related to variation in bacteriological methods. These findings underscore the need for standard S. aureus detection methods and MRSA control policies in Belgian CF centres.

• Prospective evaluation of imipenem/EDTA combined disc and Etest for detection of metallo-beta-lactamase-producing Pseudomonas aeruginosa.

  Authors: L Bergès, H Rodriguez-Villalobos, A Deplano, M J Struelens

  The Journal of antimicrobial chemotherapy. 05/2007; 59(4):812-3.

• Genetic relatedness between methicillin-susceptible and methicillin-resistant Staphylococcus aureus: results of a national survey.

  Authors: M Hallin, O Denis, A Deplano, R De Mendonça, R De Ryck, S Rottiers, M J Struelens

  The Journal of antimicrobial chemotherapy. 04/2007; 59(3):465-72.

  OBJECTIVES: Surveillance of hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) infections has shown the emergence and spread of several epidemic MRSA clones over the past 10OBJECTIVES: Surveillance of hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) infections has shown the emergence and spread of several epidemic MRSA clones over the past 10 years in Belgium. Whether these clones have been imported from abroad or else have arisen locally via staphylococcal cassette chromosome mec (SCCmec) acquisition by successful methicillin-susceptible S. aureus (MSSA) clones is unknown. METHODS: We determined by PFGE, spa typing, multi-locus sequence typing (MLST) and agr group analysis the genetic relatedness of 103 MSSA and 511 MRSA strains from a national survey of patients admitted to 112 Belgian hospitals in 2003. RESULTS: The 103 MSSA strains presented very diverse genetic backgrounds, they were distributed into 40 distinct PFGE types and clustered in 15 distinct MLST CCs. Up to 45% harboured the same genotype as five major epidemic HA-MRSA clones. These MRSA clones all harbour a type IV SCCmec element. CONCLUSIONS: These findings are consistent with multiple recent acquisitions of the more mobile type IV SCCmec by MSSA and suggest that certain genetic backgrounds are conferring a selective advantage, regardless of the resistance profile. However, since the predominant MSSA and MRSA lineages identified in Belgium are disseminated worldwide, importation of epidemic MRSA strains remains an alternative hypothesis.

• Emergence and dissemination of multidrug resistant clones of Pseudomonas aeruginosa producing VIM-2 metallo-beta-lactamase in Belgium.

  Authors: A Deplano, H Rodriguez-Villalobos, Y Glupczynski, P Bogaerts, D Allemeersch, A Grimmelprez, G Mascart, L Bergès, B Byl, C Laurent, M J Struelens

  Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin. 02/2007; 12(1):E070118.2.

• Validation of pulsed-field gel electrophoresis and spa typing for long-term, nationwide epidemiological surveillance studies of Staphylococcus aureus infections.

  Authors: M Hallin, A Deplano, O Denis, R De Mendonça, R De Ryck, M J Struelens

  Journal of clinical microbiology. 02/2007; 45(1):127-33.

  Pulsed-field gel electrophoresis (PFGE) of genomic macrorestriction fragments has been used by the Belgian Reference Laboratory for Staphylococci for national hospital surveys ofPulsed-field gel electrophoresis (PFGE) of genomic macrorestriction fragments has been used by the Belgian Reference Laboratory for Staphylococci for national hospital surveys of methicillin-resistant Staphylococcus aureus since 1992. The sequencing of the polymorphic X region of the protein A gene (spa typing) offers significant advantages over PFGE in terms of speed, ease of interpretation, and exportability. To validate its potential use for national surveillance, we evaluated the robustness of spa typing compared with that of PFGE based on a collection of 217 S. aureus strains representative of the Belgian S. aureus epidemiology during the last 13 years. spa typing and PFGE both showed high discriminatory power (discriminatory indexes of 0.98 and 0.96, respectively) and achieved high concordance (95.9%) in type classification. Both methods also showed good concordance with multilocus sequence typing (MLST) (95.5%). However, we observed occasional "violations" of MLST clonal complex assignment by spa typing. Our results suggest that both PFGE and spa typing are reliable methods for long-term, nationwide epidemiological surveillance studies. We suggest that spa typing, which is a single-locus-based method, should preferably be used in combination with additional markers, such as staphylococcal cassette chromosome mec typing or resistance or virulence gene detection.