Mapping of the bacterial flora of products entering the Controlled Atmosphere Zone: catch them all!

Goals
To ensure the effectiveness of a decontamination chamber, the initial biocharge must be as low as possible. Some of our samples from the CAZ (Controlled Atmosphere Zone) have returned positive. The analysis of these results is subcontracted. Our study aims to map the bacterial flora in order to compare our results with those of the subcontractor laboratory.

Materials & method
We define the nature and location of the samples: solutes (folds, pocket), medical devices (MD), bottles of chemotherapy (bottle and cap), environment (cell phone, wheels of the storage trolley, trash, floor). We took our samples in the cytotoxic storage room, by using swabs. In the hospital laboratory, they were seeded in different types of agars and identified by MALDI TOF.

Results & Discussion
Of 28 samples, 18 came back positive (36%): 3 from solutes, 1 from MD, 6 from the environment, 0 for chemotherapy bottles. We found 42% Staphylococcus, 50% Bacillus, 8% Enterococcus. The solutes, especially the folds (all tested were positive), infusion device and the trash presented Bacillus, bacteria of the environment. MD, mostly solute folds can enter germs into isolators. The phone presented Staphylococcus, from the skin flora. The wheels had Staphylococcus, Bacillus, and Enterococcus from the intestinal flora. This last result is explained by the fact that the wheels are not tested. The trolley is moved from the storage room to the preparation room, so there is a risk of transfer germs. The absence of positives in the bottles may be due to laboratory rinsing which seems effective.

Conclusion
Our study provides an overview of the potential gateways to the CAZ. Comparing with laboratory positives, we confirm the presence of Staphylococcus and Bacillus. The study highlights the presence of a new species: Enterococcus. Special attention should be paid to the solute folds which can be a risk zone of escape during decontamination. Regarding the procedures put in place: the wheels will be cleaned monthly and will be tested in routine. We will limit the movement of the trolley. The removal of the overpack before decontamination, subject to the safety of the decontaminant on the bag and solvent, is being considered. It would be interesting to test risk areas from the solutes after entering the insulator and to take samples after procedures are in place to assess their effectiveness.

Key words: Controlled Atmosphere Zone, bacterial flora, storage room,swaps

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