Prevalence and mechanisms of resistance to carbapenems in Enterobacteriaceae

Objectives: To determine the point prevalence of carbapenem-non-susceptible Enterobacteriaceae (CNSE) and carbapenemase-producing Enterobacteriaceae (CPE) isolates among hospitalized patients in Belgium. Methods: Twenty-four hospital-based laboratories prospectively collected 200 non-duplicated Enterobacteriaceae isolates from clinical specimens of hospitalized patients over a 2 month period. All isolates were screened locally for decreased susceptibility to carbapenem drugs using a disc diffusion method according to CLSI interpretative criteria. CNSE strains were referred centrally for confirmation of carbapenemase by phenotypic and molecular testing. Results: From February to April 2012, 158 of the 4564 screened Enterobacteriaceae isolates were categorized as non-susceptible to carbapenems, resulting in a point prevalence of CNSE of 3.5% (95% CI: 2.9%–4.2%; range per centre: 0.5%–8.5%). Of the 125 referred CNSE isolates, 11 Klebsiella pneumoniae isolates [OXA-48 (n=7), KPC type (n=3) and NDM type (n=1)], 1 OXA-48-positive Escherichia coli isolate and 1 KPC-positive Klebsiella oxytoca isolate were detected in eight hospitals. None of the 72 carbapenem-non-susceptible Enterobacter spp. isolates were confirmed as CPE. The minimal estimated point prevalence of CPE isolates was 0.28% (13/ 4564; 95% CI: 0.13%–0.44%) overall (range per centre: 0%–1.5%). Conclusions: Despite the overall low prevalence of CNSE found in this study, the detection of CPE isolates in one-third of the participating centres raises concerns and highly suggests the spread and establishment of CPE in Belgian hospitals

Evaluation of gas-liquid chromatography (GLC) for rapid detection of Clostridium difficile in fecal specimens.

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Antimicrobial susceptibility among Gram-positive and Gram-negative isolates collected in Europe between 2004 and 2010

Here we report on the in vitro activity of a suite of antimicrobial agents against Gram-negative and Gram-positive pathogens collected in Europe between 2004 and 2010 as part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.). Clinical and Laboratory Standards Institute (CLSI) broth microdilution methodologies were used to determine minimum inhibitory concentrations. CLSI interpretive criteria were applied for all antimicrobial agents to establish susceptibility; European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints were used for tigecycline. In total, 46,921 Gram-negative and 19,174 Gram-positive isolates were included in this study. Extended-spectrum β-lactamases increased in proportion from 15.7% to 21.1% among Klebsiella pneumoniae and from 9.7% to 16.1% among Escherichia coli isolates between 2004-2007 and 2010. E. coli susceptibility decreased to most antimicrobials but it remained highly susceptible (>98%) to tigecycline and meropenem. Acinetobacter baumannii susceptibility also decreased to most agents. The proportion of meticillin-resistant Staphylococcus aureus (MRSA) decreased from 25.7% to 19.4% over the study period. Antimicrobial susceptibility has decreased among many of the pathogens observed in the T.E.S.T. surveillance study between 2004-2007 and 2010. © 2014 International Society for Chemotherapy of Infection and Cancer.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Low prevalence of methicillin-resistant Staphylococcus aureus with reduced susceptibility to glycopeptides in Belgian hospitals

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Evaluation of New Vitek 2 Card and Disk Diffusion Method for Determining Susceptibility of Staphylococcus aureus to Oxacillin

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

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

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Comparative epidemiology of Staphylococcus epidermidis isolated from patients with catheter-related bacteremia and from healthy volunteers.

Introduction Staphylococcus epidermidis (SE) is a major cause of catheter-related bloodstream infections (CRBSI). Recent studies suggested the existence of well adapted, highly resistant, hospital-associated SE clones. The molecular epidemiology of SE in the Belgian hospitals and community has not been explored yet.Objectives We compared a set of 33 SE isolates causing CRBSI in hospitalized patients with a set of 33 commensal SE isolates. Analyzed factors included resistance to antibiotics and genetic diversity as determined by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and SCCmec typing. Additionally, the presence of virulence-associated mobile genetic elements, the ica operon and the arginine catabolic mobile element (ACME), was assessed and confronted to clinical data.Results CRBSI SE isolates were significantly resistant to more antibiotics than commensal SE isolates. The two populations studied were very diverse and genetically distinct as only 23% of the 37 PFGE types observed were harbored by both CRBSI and commensal isolates. ACME was found in 76% of SE strains, regardless of their origin while the ica operon was significantly more prevalent in CRBSI isolates than in commensal isolates (P< 0.05). Nine patients presented a clinically severe CRBSI, eight of which were due to an ica positive multi-resistant isolate belonging to ST2 or ST54.Conclusions SE isolates causing CRBSI were more resistant and more often ica positive than commensal SE isolates, that were genetically heterogeneous and susceptible to the majority of antibiotics tested. Clinically severe CRBSI were due to isolates belonging to two closely related MLST types, ST2 and ST54.JOURNAL ARTICLESCOPUS: ar.jinfo:eu-repo/semantics/publishe

Evaluation of the automated Vitek 2 system for detection of various mechanisms of macrolide and lincosamide resistance in Staphylococcus aureus

We evaluated the performance of the automated Vitek 2 system against disk diffusion for susceptibility testing of Staphylococcus aureus strains showing various resistance mechanisms to macrolides and lincosamides (ML). The Vitek 2 system showed 100% concordance with the D-zone test in detection of the most common resistance mechanisms to ML, including methylase and efflux systems.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Prospective Two-Center Comparison of Three Chromogenic Agars for Methicillin-Resistant Staphylococcus aureus Screening in Hospitalized Patients

Three chromogenic media, chromID MRSA SMART (SMART), chromID MRSA first generation (chromID), and Brilliance MRSA (OX2), were evaluated for methicillin-resistant Staphylococcus aureus (MRSA) screening using 1,220 samples. The sensitivity at 24 h was significantly better with the SMART agar (66.4%) than that with chromID agar (50.5%). Enrichment and incubation until 48 h are still needed for an optimal yield

National surveillance of Staphylococcus epidermidis recovered from bloodstream infections in Belgian hospitals

Objectives: The objectives of this study were: (i) to determine the species diversity of CoNS isolated from bloodstream infections collected during a national surveillance study; and (ii) to examine the antimicrobial resistance and genomic diversity among Staphylococcus epidermidis isolates. Methods: Eighty CoNS were identified by MALDI-TOF. Antimicrobial resistance determination, molecular characterization of resistance and virulence genes, and molecular typing were performed for S. epidermidis isolates. Results: The majority (76%) of CoNS were identified as S. epidermidis. Among these S. epidermidis, 77% were resistant to methicillin [methicillin-resistant S. epidermidis (MRSE)] and showed multiresistance to other antimicrobials. Genes implicated in resistance were erm(C), erm(A) and msr(A) for erythromycin, aacA-aphD and aadC for aminoglycosides, tet(K) for tetracycline and mupA for high-level resistance to mupirocin. Molecular typing showed that 34/40 MRSE isolates (85%) belonged to clonal complex (CC) 2 that could be subdivided into CC2-I (ST2) and CC2-II (ST5, ST59 and ST88). In contrast, methicillin-susceptible S. epidermidis displayed high genomic diversity. The majority (70%) of S. epidermidis isolates contained an icaA or arcA gene. The icaA gene was found in the CC2-I subgroup, whereas arcA was more common in methicillin-susceptible S. epidermidis. Conclusions: S. epidermidis was frequently recovered among CoNS isolated from bloodstream infections with a high proportion of MRSE being multiresistant. A large number of S. epidermidis belonged to CC2, a clone that is disseminated worldwide. More studies are needed to understand its clonal evolutionary success.SCOPUS: ar.jinfo:eu-repo/semantics/publishe