Current Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in Elderly French People: Troublesome Clones on the Horizon.

In 2015, we conducted at 44 healthcare facilities (HCFs) and 21 nursing homes (NHs) a 3-month bloodstream infection (BSI) survey, and a 1-day prevalence study to determine the rate of carriage of methicillin-resistant Staphylococcus aureus (MRSA) in 891 patients and 470 residents. We investigated the molecular characteristics of the BSI-associated and colonizing MRSA isolates, and assessed cross-transmission using double-locus sequence typing and pulsed-field gel electrophoresis protocol. The incidence of MRSA-BSI was 0.040/1000 patient-days (19 cases). The prevalence of MRSA carriage was 4.2% in patients (n = 39) and 8.7% in residents (n = 41) (p < 0.001). BSI-associated and colonizing isolates were similar: none were PVL-positive; 86.9% belonged to clonal complexes 5 and 8; 93.9% were resistant to fluoroquinolones. The qacA/B gene was carried by 15.8% of the BSI-associated isolates [3/3 BSI cases in intensive care units (ICUs)], and 7.7% of the colonizing isolates in HCFs. Probable resident-to-resident transmission was identified in four NHs. Despite generally reassuring results, we identified two key concerns. First, a worryingly high prevalence of the qacA/B gene in MRSA isolates. Antisepsis measures being crucial to prevent healthcare-associated infections, our findings raise questions about the potential risk associated with chlorhexidine use in qacA/B(+) MRSA carriers, particularly in ICUs. Second, NHs are a weak link in MRSA control. MRSA spread was not controlled at several NHs; because of their frequent contact with the community, conditions are favorable for these NHs to serve as reservoirs of USA300 clone for local HCFs

Molecular Characterization of Human-Colonizing Streptococcus agalactiae Strains Isolated from Throat, Skin, Anal Margin, and Genital Body Sites▿

Streptococcus agalactiae carriage was evaluated by sampling four body sites in a group of 249 healthy individuals including both sexes and a wide range of ages; the aims were to study the population structure of colonizing strains by multilocus sequence typing (MLST) and to evaluate their diversity by serotyping, SmaI macrorestriction analysis, and PCR screening for genetic markers of highly virulent clones for neonates. The prevalences of carriage were 27% in women and 32% in men. The major positive body site was the genital tract (23% in women and 21% in men); skin, throats, and anal margins were also positive in 2%, 4%, and 14%, respectively. These human-colonizing strains belonged mostly to serotypes III (24%), Ia (21%), V (18%), and Ib (17%). Twenty-three sequence types (STs) were identified. The MLST characteristics of the strains isolated from a single anatomic site—genital (vagina [women] or from a sample of the first urination after arising from a night's sleep [men]), throat, skin, or anal margin—suggest a body site colonization specificity for particular STs: strains of STs 2, 10, 19, and 196 were isolated only from genital sites; strains of STs 1, 8, and 23 were isolated more frequently from throat florae; and strains recovered only from anal margin samples were more closely related to strains isolated from throats than to those from genital sites. Most strains of STs 1, 8, and 23—STs that are increasingly described as being responsible for adult infections—did not carry any markers of strains virulent for neonates, suggesting that the virulence of these strains is probably associated with other genetic determinants. In addition, the genetic diversities of the strains varied between STs: STs 2, 8, 10, 23, and 196 were the most diverse; STs 1 and 19 were more homogeneous; and ST 17 strains formed three distant groups

Staphylococcus capitis isolated from bloodstream infections: a nationwide 3-month survey in 38 neonatal intensive care units

International audienceTo increase the knowledge about S. capitis in the neonatal setting, we conducted a nationwide 3-month survey in 38 neonatal intensive care units (NICUs) covering 56.6% of French NICU beds. We demonstrated 14.2% of S. capitis BSI (S.capBSI) among nosocomial BSIs. S.capBSI incidence rate was 0.59 per 1000 patient-days. A total of 55.0% of the S.capBSIs were late onset catheter-related BSIs. The S. capitis strains infected preterm babies (median gestational age 26 weeks, median birth weight 855 g). They were resistant to methicillin and aminoglycosides and belonged to the NRCS-A clone. Evolution was favorable in all but one case, following vancomycin treatment