Comparison of different incubation conditions for microbiological environmental monitoring.

Abstract

Microbiological environmental monitoring confirms that pharmaceutical cleanrooms are in an appropriate hygienic condition for manufacturing of drug products. Guidance documents from different health authorities or expert groups differ regarding recommendation of the applied incubation time, incubation temperature, or nutrient media. Therefore, many pharmaceutical manufacturers perform studies that aim to identify the optimal incubation setup for environmental monitoring samples. An informal survey of the results of such studies, which had been performed at Novartis or European manufacturing sites of different pharmaceutical companies, highlighted no consensus regarding the optimal incubation conditions for microbial recovery. All these studies had been conducted in the laboratory using selections of cultured microbial strains. We tried to solve this disagreement by collecting a significant amount of real environmental monitoring samples directly from the environment in pharmaceutical production and packaging rooms during manufacturing operation. These samples were then incubated under different conditions suggested in the regulatory guidelines. We believe that the results of our study are more meaningful than laboratory-based experiments because we used environmental samples with microorganisms directly isolated from the manufacturing area. Therefore, we believe that our results should represent a valuable reference for definition of the incubation strategy of microbiological environmental monitoring samples.