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

Abstract

<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