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Poster (Scientific congresses and symposiums)
Phenotypical and Genotypical Surveillance of Macrolide and Lincosamide Resistance in Group B Streptococcus in Belgium
DESCY, Julie; Ackermans, Yannick; BOREUX, Raphaël et al.
201252nd ICAAC


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Keywords :
Group B streptococcus; Macrolide; resistance
Abstract :
[en] Background: Constant increase of erythromycin (E) and clindamycin (C) resistance (R) has been observed worldwide among isolates of group B streptococci (GBS). In Belgium, through the 2000s, E R increased rapidly from 10% to up to 30%. Therefore phenotypical and molecular surveillance of E and C R has to be conducted. Methods: 275 clinical isolates (N1) were obtained from a Belgian surveillance for invasive GBS disease in newborns (59 isolates with 32 early- and 27 late-onset diseases) and adults (216 strains) during 2008 to 2011 and 53 isolates (N2) from vagino-rectal colonization in pregnant women in 2010. E and C MICs were determined by using Etest® (EUCAST interpretive criteria). Furthermore, for the E R isolates, the inducible (iMLS), constitutive (cMLS) and M phenotypes were assessed by a double disk diffusion test; the distribution of genes encoding RNA methylases and efflux pumps was investigated by PCR. Results: Of the N1 and N2 isolates, 92 (33.5%) and 15 (28.3%) were respectively R to E, with a higher rate among serotype V (p <0.001) and serotype IV (p <0.05). Among these 107 E-R isolates, 100 (93.5%) exhibited the MLS phenotype (R to E and CC): 73 were cMLS with E MIC50 >256 mg/L and 27 iMLS with E MIC50/MIC90 12/>256 mg/L. The M phenotype (R to E and S to C) was expressed by 7 (6.5%) of E R isolates with E MIC50/MIC90 4/12 mg/L. One colonizing strain presented a newly described resistance mechanism in GBS: the L phenotype (S to E and R to C) with a C MIC at 8 mg/L. For cMLS, the most common E R genotype was ermB (66%) (p <0.05) followed by ermTR (29%) and ermB+ermTR (5%). All iMLS isolates harbored an ermTR gene except 3 (2 with ermB, 1 with both ermB and ermTR); and all M phenotype were positive for mefA/B gene. Conclusions:1) In Belgium, by year 2010, prevalence of macrolides R in GBS exceeded 30%, 2) MLS R phenotypes (target-site modification) were the majority mechanism; M phenotype (efflux R mechanism) was also prevalent. 3) E and C susceptibility testing and surveillance are mandatory to guide prophylaxis and treatment of serious GBS infections in penicillin-allergic patients (at high risk for anaphylaxis) but also to identify emergence of newly acquired resistance mechanisms such as the L phenotype.
Research center :
National Reference Centre for Group B Streptococci
Disciplines :
Public health, health care sciences & services
Reproductive medicine (gynecology, andrology, obstetrics)
Immunology & infectious disease
Laboratory medicine & medical technology
Author, co-author :
DESCY, Julie ;  Centre Hospitalier Universitaire de Liège - CHU > Microbiologie médicale
Ackermans, Yannick;  Centre Hospitalier Universitaire de Liège - CHU > microbiologie médicale
BOREUX, Raphaël ;  Centre Hospitalier Universitaire de Liège - CHU > Microbiologie médicale
MEEX, Cécile ;  Centre Hospitalier Universitaire de Liège - CHU > Microbiologie médicale
Rémont, Leslie ;  Université de Liège - ULiège > 4e an. méd.
Rodriguez Cuns, Grisel ;  Université de Liège - ULiège > Doct. sc. bioméd. & pharma. (Bologne)
MELIN, Pierrette  ;  Centre Hospitalier Universitaire de Liège - CHU > Microbiologie médicale
Language :
Title :
Phenotypical and Genotypical Surveillance of Macrolide and Lincosamide Resistance in Group B Streptococcus in Belgium
Publication date :
September 2012
Event name :
52nd ICAAC
Event organizer :
American Society of Microbiology
Event place :
San Francisco, United States
Event date :
du 9 septembre 2012 au 12 septembre 2012
Audience :
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since 04 June 2013


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