Seasonal Assessment of Microbial Contamination and Disinfectant Efficacy in Cleanroom using MALDI-TOF MS in a NABL-Accredited Pharmaceutical Testing Laboratory

Background: Microbial bioload control in clean rooms is critical for ensuring pharmaceutical product quality. Regular monitoring and effective disinfection practices are essential to minimize contamination risks. This study aimed to identify and analyze microbial contamination in clean rooms across different seasons using MALDI TOF MS for rapid microbial identification. Materials and Methods: Microbial samples were collected pre- and post-fogging from a NABL-accredited cleanroom using settle plates and active air sampling methods. The fogging was performed with a QUAT-based disinfectant. Samples were analyzed using Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI TOF MS) for rapid and reliable identification of microbial species. The study was conducted across three seasonal periods-summer, monsoon, and winter-to assess seasonal variation in microbial contamination. Results: MALDI TOF MS identified common microbial contaminants such as Pseudomonas stutzeri, Staphylococcus spp., Bacillus spp., and Micrococci spp. Significant seasonal variations were observed in microbial populations. Post-fogging, the microbial load was reduced by approximately 90% during the monsoon, 40% in summer, and 57% in winter. The identification process using MALDI TOF MS allowed for rapid and reliable analysis of the cleanroom microbial environment. Conclusion: MALDI TOF MS proved effective for quick and accurate identification of cleanroom microbial contaminants. The QUAT-based fogging process effectively reduced microbial loads, though efficacy varied seasonally. Regular monitoring, coupled with rotational disinfectant use, supports enhanced contamination control strategies in pharmaceutical cleanroom environments.