<i>Pseudomonas aeruginosa</i> contamination in purified water systems: case study in a pharmaceutical industry

Purified water is critical to the pharmaceutical industry. It is used at various stages of production and is subject to strict quality standards. This paper presents a case study of <i>Pseudomonas aeruginosa</i> microbiological contamination in a Brazilian pharmaceutical company9s purified water generation and distribution system. The study investigates the causes of contamination, its microbiological and operational impacts on the production process, and the corrective and preventive measures adopted. The analysis involved examining internal documents, physicochemical and microbiological monitoring records, sanitation procedures, and system qualification reports. The results revealed operational failures during sanitation, mainly due to insufficient Standard Operating Procedures instructions for the aseptic handling of the mixed-bed resin and the risk of recontamination after system opening. The sanitizer that was routinely used, sodium metabisulfite, was ineffective at eliminating the microorganism and was replaced by peracetic acid, which eradicated the <i>P. aeruginosa</i> contamination. However, incompatibility of the new agent with system components was observed, which compromised water quality parameters. In conclusion, effective microbiological control requires efficient sanitizers, well-defined procedures, material compatibility, and alignment with good manufacturing practices. Additionally, the importance of continuous monitoring, a culture of quality, and structured change management to ensure sanitary industrial processes should be emphasized.