Bacillus spp. bacteraemia in children on parenteral nutrition

Abstract number: p1008

Lebessi  E., Antonaki  G., Zafiropoulou  A., Malliou  K., Paleologou  N., Foustoukou  M.

Objectives: 

To study the epidemiologic and clinical data concerning bacteremia due to Bacillus spp. associated with total parenteral nutrition (TPN), during a four-year period (2002–2005).

Methods: 

Patients, who presented clinical signs of bacteremia while receiving TPN, with blood and/or TPN solution culture positive for Bacillus spp. were included. Blood drawn from peripheral veins and samples of the discontinued TPN solutions were cultured by the BacT/Alert system (bioMerieux, France). TPN solutions were also cultured quantitatively. Identification of microorganisms was carried out using Gram stain, colony morphology, motility test and lecithinase production at egg yolk agar (Oxoid, England), BBL Crystal Positive ID kit (Becton Dickinson, USA) and/or API20E/50CHB (bioMerieux, France). Three epidemiological environment surveys in TPN preparation room (PPR) were performed, according to the hospital infection control guidelines, when clusters of episodes occurred (Sept 2003, Jun 2004, Oct 2005).

Results: 

During the study period, 23 episodes occurred in 20 patients ranged in age from 6 days to 14 years. Bacteremia due to Bacillus spp. was documented by positive blood culture in 14 cases. TPN was discontinued in 7 cases and TPN solutions were found to be contaminated with the same organism. Bacillus spp. was also isolated from TPN solutions involved in 9 episodes, with negative (n = 5) or not performed (n = 4) blood culture. B. cereus (11 strains) and B.megaterium (10 strains) were the most common species isolated, followed by B. pumilus (1 strain) and Brevibacillus brevis (1 strain). The implicated organisms were also recovered from the laminar flow-hood of PPR. Abrupt onset, presented with fever and/or chills, occurred in all patients, accompanied with vomiting and diarrhoea (one case) and thrombophlebitis (one case). Dramatic clinical response was observed to discontinuing the infusion. No deaths were observed.

Conclusions: 

The isolation of Bacillus spp. from the laminar flow-hood and the TPN solutions suggested the in-use contamination during the preparation and compounding of admixtures. Bacillus spp. due to spores formation can resist to disinfectants. We emphasize the need for stringent asepsis in the hospital pharmacy, in order to avoid the contamination of infusates with potential pathogens, widely distributed in the environment, such as Bacillus spp.