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Ariane Deplano

Publications and source records attributed to Ariane Deplano.

11 recordsLinked to original sources
PubMed2007

Emergence of ArmA and RmtB aminoglycoside resistance 16S rRNA methylases in Belgium.

OBJECTIVES: 16S rRNA methylase-mediated high-level resistance to aminoglycosides has been reported recently in clinical isolates of Gram-negative bacilli only from a limited number of countries. This study was conducted to investigate the occurrence of this type of resistance in clinical isolates of Enterobacteriaceae from two Belgian hospitals and the characteristics of the strains. METHODS: We screened for high-level gentamicin, tobramycin and amikacin resistance in clinical isolates of Enterobacteriaceae consecutively collected between 2000 and 2005 at two laboratories by PCR for the armA, rmtA and rmtB 16S rRNA methylase genes. The beta-lactamase presence in the strains was also determined by phenotypic and genotypic methods. RESULTS: Overall armA genes were detected in 18 Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae and Citrobacter amalonaticus whereas rmtB was detected in a single E. coli isolate. The rmtA gene was not found. All 16S rRNA methylase-bearing strains produced extended-spectrum beta-lactamases (ESBLs), predominantly type CTX-M-3, as well as various types of beta-lactamases. In the majority of the strains, the armA gene was carried by conjugative plasmids of the IncL/M incompatibility group whereas rmtB was borne by an IncFI plasmid. CONCLUSIONS: This is the first report of the emergence of 16S rRNA methylases in Enterobacteriaceae in Belgium. The rapid spread of multidrug-resistant isolates producing both ESBLs and 16S rRNA methylases raises clinical concern and may become a major therapeutic threat in the future.

Aminoglycosides↗
PubMed2006

In vitro activities of ceftobiprole, tigecycline, daptomycin, and 19 other antimicrobials against methicillin-resistant Staphylococcus aureus strains from a national survey of Belgian hospitals.

The in vitro activities of 22 antimicrobial agents, including ceftobiprole, daptomycin, and tigecycline, against 511 methicillin-resistant Staphylococcus aureus (MRSA) isolates from 112 Belgian hospitals were studied by using the CLSI agar dilution method. Isolates were characterized by pulsed-field gel electrophoresis (PFGE) analysis and by PCR detection of determinants of resistance to aminoglycosides, macrolides-lincosamides-streptogramins, and tetracyclines. A representative set of isolates with different PFGE genotypes was further characterized by multilocus sequence typing, determination of staphylococcal cassette chromosome mec (SCCmec) type, and multiplex PCR for toxic shock syndrome type 1 (TSST-1) and Panton-Valentine leukocidin genes. MRSA isolates belonged to nine epidemic MRSA clones, of which sequence type 45 (ST45)-SCCmec IV and ST8-SCCmec IV were predominant, accounting for 49 and 20% of isolates, respectively. The distribution of antimicrobial resistance and TSST-1 genes was strongly linked to clonal types. Ceftobiprole, daptomycin, and tigecycline showed high activity against all isolates of these sporadic and epidemic MRSA clones, as indicated by MIC(90)s of 2 mg/liter, 0.5 mg/liter, and 0.25 mg/liter, respectively. The MIC distribution of daptomycin and tigecycline was not different in isolates with decreased susceptibility to glycopeptides or tetracyclines, respectively. Ceftobiprole MICs were not correlated with oxacillin and cefoxitin MICs. These data indicate excellent activity of the newly developed agents ceftobiprole, daptomycin, and tigecycline against MRSA isolates recently recovered from hospitalized patients in Belgium, supporting their therapeutic potential for nosocomial MRSA infections.

Anti-Bacterial Agents↗
PubMed2004

National surveillance of methicillin-resistant Staphylococcus aureus in Belgian hospitals indicates rapid diversification of epidemic clones.

Methicillin-resistant Staphylococcus aureus (MRSA) strains (n = 455) collected in 2001 from 100 Belgian hospitals were characterized by molecular typing and by resistance gene distribution to macrolides-lincosamides-streptogramins and to aminoglycoside antibiotics. Rapid diversification of MRSA clones, compared with results of previous surveys, was evidenced by the broad geographic distribution of seven major clones belonging to the pandemic MRSA clonal complexes 5, 8, 22, 30, and 45 by multilocus sequence typing.

Aminoglycosides↗
PubMed2003

Emergence and spread of gentamicin-susceptible strains of methicillin-resistant Staphylococcus aureus in Belgian hospitals.

The aim of this study was to follow the evolution of the clonal distribution and antimicrobial susceptibility of clinical strains of methicillin-resistant Staphylococcus aureus (MRSA) recovered from Belgian hospitals between 1995 and 1997-1998. MRSA strains were genotyped by inter-IS256 spacer length polymorphism PCR and SmaI macrorestriction analysis. MICs of 18 antimicrobials were determined by the agar dilution method. MRSA strains from the 1997-1998 survey were further tested by vancomycin screen agar, E-test, broth microdilution methods, and population analysis. Between 1995 and 1997-1998, epidemic group A strains decreased in proportion from 73% to 44%, whereas MRSA Group B and C strains increased from 17% to 38% and from 5% to 8%. The proportion of strains susceptible to gentamicin increased between the surveys from 22% to 48%. This was associated with a higher proportion of group B and C strains in the last survey. Heterogeneous vancomycin-intermediate S. aureus (hetero-VISA) strains were found in 2% isolates from 1997 to 1998. These hetero-VISA isolates were genotypically related to the MRSA group A strains and were resistant to gentamicin. In conclusion, two emerging epidemic MRSA genotypes, susceptible to gentamicin, have spread among Belgian hospitals during the 1990s. Hetero-VISA were present at low frequency among MRSA strains belonging to a widespread endemic genotype.

Aged↗
PubMed2003

Harmonization of pulsed-field gel electrophoresis protocols for epidemiological typing of strains of methicillin-resistant Staphylococcus aureus: a single approach developed by consensus in 10 European laboratories and its application for tracing the spread of related strains.

Pulsed-fieldgel electrophoresis (PFGE) is the most common genotypic method used in reference and clinical laboratories for typing methicillin-resistant Staphylococcus aureus (MRSA). Many different protocols have been developed in laboratories that have extensive experience with the technique and have established national databases. However, the comparabilities of the different European PFGE protocols for MRSA and of the various national MRSA clones themselves had not been addressed until now. This multinational European Union (EU) project has established for the first time a European database of representative epidemic MRSA (EMRSA) strains and has compared them by using a new "harmonized" PFGE protocol developed by a consensus approach that has demonstrated sufficient reproducibility to allow the successful comparison of pulsed-field gels between laboratories and the tracking of strains around the EU. In-house protocols from 10 laboratories in eight European countries were compared by each center with a "gold standard" or initial harmonized protocol in which many of the parameters had been standardized. The group found that it was not important to standardize some elements of the protocol, such as the type of agarose, DNA block preparation, and plug digestion. Other elements were shown to be critical, namely, a standard gel volume and concentration of agarose, the DNA concentration in the plug, the ionic strength and volume of running buffer used, the running temperature, the voltage, and the switching times of electrophoresis. A new harmonized protocol was agreed on, further modified in a pilot study in two laboratories, and finally tested by all others. Seven laboratories' gels were found to be of sufficiently good quality to allow comparison of the strains by using a computer software program, while two gels could not be analyzed because of inadequate destaining and DNA overloading. Good-quality gels and inclusion of an internal quality control strain are essential before attempting intercenter PFGE comparisons. A number of clonally related strains have been shown to be present in multiple countries throughout Europe. The well-known Iberian clone has been demonstrated in Belgium, Finland, France, Germany, and Spain (and from the wider HARMONY collection in Portugal, Slovenia, and Sweden). Strains from the United Kingdom (EMRSA-15 and -16) have been identified in several othercountries, and other clonally related strains have also been identified. This highlights the need for closer international collaboration to monitor the spread of current epidemic strains as well as the emergence of new ones.

Bacterial Typing Techniques↗
PubMed2002

Intercenter reproducibility of binary typing for Staphylococcus aureus.

The reproducibility of the binary typing (BT) protocol developed for epidemiological typing of Staphylococcus aureus was analyzed in a biphasic multicenter study. In a Dutch multicenter pilot study, 10 genetically unique isolates of methicillin-resistant S. aureus (MRSA) were characterized by the BT assay as presented by van Leeuwen et al. [J. Clin. Microbiol. 2001 39 (1) 328]. The BT assay, including a standardized DNA extraction protocol was performed in duplicate in eleven medical microbiology laboratories. Two different hybridization detection procedures were applied and a prelabeled DNA sample as process control was included. Only three laboratories accurately identified all strains. Divergence in technical procedures resulted in misinterpretation due to an increasing number of faint or absent hybridization signals in combination with high background staining. The binary type of the process control was determined correctly by all participating laboratories. The feasibility of the BT protocol was related directly to the skill of the laboratory personnel. On the basis of the national study, we concluded that the DNA extraction protocol needed modification to improve DNA yield and purity. Subsequently, seven European laboratories participated in an international study to determine the reproducibility of the modified BT protocol. Each center was asked to analyze 10 DNA samples previously extracted from 10 MRSA strains (phase 1) and, additionally, to analyze 10 MRSA strains, using the standardized or their in-house DNA isolation protocol (phase 2). A prelabeled DNA process control sample was included again. The binary types of all DNA samples were identified correctly by all but one laboratories. This latter laboratory diverged from the protocol by adding an excess of labeled DNA to the hybridization mixture, resulting in a high background and, therefore, noninterpretable BT results. All centers produced identical BT results for the process control. Five of the seven centers correctly identified the binary types of all 10 MRSA strains in phase 2 of the international study. Three of these centers used their in-house DNA extraction protocol. Divergence from the standard BT protocol in the remaining two centers resulted in no interpretable BT data for the 10 MRSA strains. The study demonstrated that each center that followed the BT protocol to the letter could generate reproducible results, irrespective whether or not an in-house DNA isolation protocol was used. The current BT protocol thus represents a simple method generating robust, reproducible genotype data for S. aureus strains.

Bacterial Typing Techniques↗
PubMed2002

Risk factors for infection and molecular typing in patients in the intensive care unit colonized with nosocomial Enterobacter aerogenes.

OBJECTIVES: To determine the frequency of colonization by Enterobacter aerogenes in patients in the intensive care unit (ICU) for more than 48 hours and to evaluate the risk factors for infection in patients colonized by this bacteria. DESIGN: An 8-month prospective study. SETTING: A 12-bed medical-surgical ICU in a 450-bed, university-affiliated, tertiary-care hospital in Belgium. METHOD: Pulsed-field gel electrophoresis was used to determine the genotypes of E. aerogenes isolates. RESULTS: We observed two major clones of E. aerogenes in the ICU. Interestingly, 87.5% of infected patients had the same genomic profile for colonization and infection. Risk factors for infection in this particular population included younger age, prolonged hospital stay, mechanical ventilation, and bronchoscopy. CONCLUSIONS: Colonization is a major prerequisite for infection. The identification of risk factors for infection in colonized patients can optimize the quality of treatment in the ICU.

Aged↗