Management of unexpected laboratory exposure to Burkholderia pseudomallei.

Burkholderia pseudomallei is a Gram-negative saprophytic bacillus that causes melioidosis. The infection is endemic in South-East of Asia and Northern Australia. B. pseudomallei has been designated as bioterrorism agent and its manipulation should be done in a biological safety level 3 capability. Workers in laboratories may be accidentally exposed to B. pseudomallei before its identification, with a risk of laboratory-acquired melioidosis. We want to describe a case of melioidosis occurred in our hospital and its management at laboratory. The objective of this article is to provide guidance to microbiologists confronted with a suspicious case of B. pseudomallei on the management of the exposition. We report here a couple of microbiological arguments that can usually guide microbiologists towards presumptive identification of B. pseudomallei. This case report shows the importance of MALDI-TOF MS accurate databases to ensure accurate microbial identification and antibiotic prophylaxis adapted to individuals who were exposed. We also want to underline the importance of developing an effective strategy of prevention against any accidental exposure that can occur in a microbiological laboratory.

Assessment of calcium hypochlorite for Bacillus anthracis spore surface's decontamination.

Contamination with microorganisms occurs in laboratories but is also of high concern in the context of bioterrorism. Decontamination is a cornerstone that promotes good laboratory practices and occupational health and safety. Among the most resistant structures formed by microorganisms are spores, produced notably by Clostridium and Bacillus species. Here, we compared six products containing four different molecules (hydrogen peroxide, peracetic acid, sodium and calcium hypochlorite) on B. anthracis Sterne spores. We first selected the most efficient product based on its activity against spore suspensions using French and European standards. Four products showed sporicidal activity, of which only two did so in a time frame consistent with good laboratory practices. Then, we tested one of these two products under laboratory conditions on fully virulent B. anthracis spores, during common use and after contamination through a spill of a highly concentrated spore suspension. We, thus, robustly validated a decontaminant based on calcium hypochlorite not only on its ability to kill spores but also on its effectiveness under laboratory conditions. At the end, we were able to assure a complete disinfection in 1 min after spillover and in 2 min for common use.