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We analyzed group B Streptococcus (GBS) neonatal invasive infections reported during 2007-2019 in France. The hypervirulent clonal complex (CC) 17 GBS was responsible for 66% (827/1,262) of cases. The role of CC17 GBS increased over time (p for trend = 0.0001), together with the emergence of a multidrug-resistant CC17 GBS sublineage.

Group B Streptococcus (GBS) is the leading cause of neonatal invasive infections and an emerging pathogen in the elderly. Our objectives were to describe the evolution of GBS resistance to antibiotics in France and to investigate the emergence of fluoroquinolone (FQ)-resistant isolates. A total of 8,757 unrelated GBS isolates were collected and tested for antibiotic susceptibility from 2007 to 2014 according to EUCAST recommendations. All isolates were susceptible to penicillin G, amoxicillin, and vancomycin. Resistance to macrolides decreased from 47.0% to 30.0%, whereas high-level resistance to aminoglycosides, especially amikacin, increased from 6.4% to 8.8% and 24 isolates (0.3%) were highly resistant to gentamicin. FQ resistance gradually increased from 0.2% in 2007 (n = 1) to 1.5% in 2014 (n = 18, P < 0.01). Capsular polysaccharide (CPS) genotyping, multilocus sequence typing, and sequencing of the quinolone resistance-determining region (QRDR) showed that GBS isolates of sequence type 19 (ST-19) CPS type V were largely overrepresented in FQ-resistant isolates (n = 30, 45.5%). All 30 strains displayed the same QRDR mutations and were often associated with cross-resistance to macrolides (93.3%) and gentamicin (30%). In conclusion, we report the rise of FQ- and aminoglycoside-resistant GBS in France over an 8-year study period, an evolution likely linked to the clonal expansion of ST-19 CPS V-resistant isolates. This study emphasizes the need for a continuous surveillance of GBS epidemiology and antibiotic susceptibility., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Among 1,827 group B Streptococcus (GBS) strains collected between 2006 and 2013 by the French National Reference Center for Streptococci, 490 (26.8%) strains were erythromycin resistant. The erm(T) resistance gene was found in six strains belonging to capsular polysaccharides Ia, III, and V and was carried by the same mobilizable plasmid, which could be efficiently transferred by mobilization to GBS and Enterococcus faecalis recipients, thus promoting a broad dissemination of erm(T)., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Objectives: Actinobaculum schaalii is a Gram-positive bacillus increasingly reported as a causative agent of urinary tract infections as well as invasive infections, mainly in the elderly and patients with underlying urological conditions. Since little is known about the molecular basis of antimicrobial resistance in A. schaalii, the aim of this study was to investigate resistance to macrolides, lincosamides and streptogramins (MLS) in this emerging pathogen., Methods: A total of 32 A. schaalii clinical isolates from France and Switzerland were studied. MICs of erythromycin, spiramycin, lincomycin, clindamycin and quinupristin/dalfopristin were determined by the agar dilution method. Resistance genes erm(A), erm(B), erm(C), erm(F), erm(G), erm(X), msr(A) and mef(A) were screened by PCR. The genetic environment was determined by random cloning and PCR mapping., Results: Out of 32 isolates tested, 21 were highly resistant to erythromycin, spiramycin, lincomycin and clindamycin (MICs >256 mg/L), whereas 11 exhibited low MICs (MICs < 0.12 mg/L). On the other hand, quinupristin/dalfopristin remained active against all the isolates. An inducible MLSB resistance phenotype was noted in all cases. The erm(X) gene was detected among all resistant strains, whereas none was detected in susceptible strains. Analysis of genetic support and environment revealed that erm(X) was probably part of the chromosome of A. schaalii., Conclusions: This study is the first molecular characterization of MLS resistance in A. schaalii. In all cases, it was due to the presence of erm(X), a methylase gene previously identified in other clinically relevant Gram-positive bacilli., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)