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.

No abstract

This work illustrates the inter-country spread of VEB-1-producing A. baumannii isolates as well as the emergence of PER-1-producing A. baumannii strains in Belgium.

During an 8-month period, 24 Corynebacterium striatum isolates recovered from lower respiratory tract specimens of 10 hospitalized patients were characterized. The organisms were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and by 16S rRNA gene sequencing. The cluster of C. striatum exclusively affected patients who had been admitted to an intensive care unit and/or subsequently transferred to one medium-size respiratory care unit. Prolonged duration of hospitalization, advanced stage of chronic obstructive pulmonary disease, recent administration of antibiotics and exposure to an invasive diagnostic procedure were the most commonly found risk factors in these patients. Seven patients were colonized and three infected. All strains displayed a similar broad spectrum resistance to antimicrobial agents, remaining susceptible to vancomycin only. Typing analysis by MALDI-TOF MS and by semi-automated repetitive sequence-based PCR (DiversiLab typing) showed that all outbreak-associated C. striatum isolates clustered together in one single type while they differed markedly from epidemiologically unrelated C. striatum isolates. Pulsed-field gel electrophoresis (PFGE) profiles revealed three distinct PFGE types among the C. striatum isolates associated with the outbreak while all external strains except one belonged to a distinct type. We conclude that C. striatum is an opportunistic nosocomial pathogen in long-term hospitalized patients and can be at the origin of major outbreaks. The routine use of MALDI-TOF MS greatly facilitated the recognition/identification of this organism in clinical samples and this technique could also offer the potential to be used as an easy and rapid epidemiological typing tool for outbreak investigation.

Microbial resistance through extended-spectrum ␤-lactamase (ESBL) was first reported in the early 1980s in Europe and subsequently in the United States soon after the introduction of third-generation cephalosporins in clinical practice (12). Today, this resistance mechanism has emerged globally, and ESBL-producing Enterobacteriaceae are recognized worldwide as nosocomial pathogens of major importance (19,28). Many clinical microbiology laboratories have problems with the detection of ESBL-mediated resistance, and the recent emergence and spread of novel types of community-acquired ESBLs, such as the CTX-M enzymes (2, 4), have created additional challenges that further complicate the detection of this resistance mechanism (1, 13). Several phenotypic tests have been recommended for screening and confirmation of ESBLs, but these are usually performed on isolated organisms following culture and antibiotic susceptibility testing (7, 24).The failure to detect ESBL-mediated resistance has led to treatment failure (17, 26) and contributed to uncontrolled spread of ESBL-producing organisms (18). On the other hand, laboratory-based detection of patients infected or colonized by ESBL-producing organisms by surveillance cultures has proven useful to control and terminate nosocomial outbreaks (16,19,21).Various selective media have been proposed to assess the carriage of ESBL producers in stools. Examples of such media include Drigalski agar supplemented with cefotaxime (27), MacConkey agar supplemented with ceftazidime (20), and nutrient agar supplemented with ceftazidime, vancomycin, and amphotericin B (21). In recent years, chromogenic media were initially developed for the detection and presumptive identification of urinary tract pathogens (6, 11) as well as for the improved isolation of Staphylococcus aureus from clinical specimens (5, 10). Recently, selective antibiotic-containing chromogenic media have been made available for the rapid detection of methicillin-resistant S. aureus (9, 23). One of the great advantages of such chromogenic selective media is that they allow the rapid and reliable screening of methicillin-resistant S. aureus colonization directly from contaminated clinical specimens (14).The purpose of this study was to evaluate the sensitivity and specificity of a novel prototype of selective chromogenic agar medium (ESBL-Bx; bioMérieux, Marcy l'Etoile, France) that enables the detection and presumptive identification of ESBLproducing Enterobacteriaceae directly from clinical specimens. MATERIALS AND METHODS Specimens.A total of 644 clinical samples, including 561 stool, 63 lower respiratory tract (sputum, bronchial, or endotracheal aspirates), and 20 miscellaneous samples (wound swabs or ear-nose-throat specimens), were referred to our department for the screening of ESBL-producing organisms. The specimens originated from 460 patients who had been hospitalized in various wards (geriatric unit, general medicine, oncohematology, and general surgery departments) for more than 48 h.Inoculation of media and i...