<i>Bacillus cereus</i>, a serious cause of nosocomial infections: Epidemiologic and genetic survey

<div><p><i>Bacillus cereus</i> is the 2^nd most frequent bacterial agent responsible for food-borne outbreaks in France and the 3^rd in Europe. In addition, local and systemic infections have been reported, mainly describing individual cases or single hospital setting. The real incidence of such infection is unknown and information on genetic and phenotypic characteristics of the incriminated strains is generally scarce. We performed an extensive study of <i>B</i>. <i>cereus</i> strains isolated from patients and hospital environments from nine hospitals during a 5-year study, giving an overview of the consequences, sources and pathogenic patterns of <i>B</i>. <i>cereus</i> clinical infections. We demonstrated the occurrence of several hospital-cross-contaminations. Identical <i>B</i>. <i>cereus</i> strains were recovered from different patients and hospital environments for up to 2 years. We also clearly revealed the occurrence of inter hospital contaminations by the same strain. These cases represent the first documented events of nosocomial epidemy by <i>B</i>. <i>cereus</i> responsible for intra and inter hospitals contaminations. Indeed, contamination of different patients with the same strain of <i>B</i>. <i>cereus</i> was so far never shown. In addition, we propose a scheme for the characterization of <i>B</i>. <i>cereus</i> based on biochemical properties and genetic identification and highlight that main genetic signatures may carry a high pathogenic potential. Moreover, the characterization of antibiotic resistance shows an acquired resistance phenotype for rifampicin. This may provide indication to adjust the antibiotic treatment and care of patients.</p></div

Correlation clusters of the quantitative variables characterizing each <i>B</i>. <i>cereus</i> strain isolated from patients.

<p>The percentages of variation explained by the principal components (PC1 and PC2) are indicated in brackets. The factors involved in PC1 (Dim1: age of patients and NHE indice) and PC2 (Dim2: HBL indice) are indicated in the variable factor map at the top right of the figure. The strains located inside a colored circle belong to the same cluster, as determined by the hierarchical cluster analysis performed after PCA. Each dot corresponds to a strain. The squares represent the representative value for the cluster.</p

Characteristics of patients or hospital environment displaying <i>B</i>. <i>cereus</i> positive samples.

<p>Characteristics of patients or hospital environment displaying <i>B</i>. <i>cereus</i> positive samples.</p

M13-PCR fingerprint patterns of <i>B</i>. <i>cereus</i> strains showing eight possible cross contaminations between patients/patients or patients/environment.

<p>Top panel, lane 1: 1kb DNA ladder. Lane 2: reference strain <i>B</i>. <i>cereus</i> ATCC14579. Lane 2 to 23: <i>B</i>. <i>cereus</i> strains. Bottom: divergence tree between eight samples obtained by hierarchical clustering based on the matrix of pairwise divergences after WGS data.</p

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