Prevent Future Sterility Failures by Identifying Contaminating Microorganisms
James Zellner, Technical Sales
Identification of a contaminant in a sterile preparation is vital to determining the origin of the microorganism and its avenue of entry. The organism’s identity, combined with environmental monitoring data, provides actionable information to improve a pharmacy’s processes and prevent future contamination.
Organisms can enter a drug product through:
The source of microorganisms can potentially be determined by considering their normal habitat. For example, a large group of organisms are considered normal skin flora. Microorganisms like Staphylococcus aureus, Micrococcus luteus, and Propionibacterium acnes are found on every technician that enters a cleanroom. If skin flora is found in a sterile preparation, it could indicate improper gowning and gloving or insufficient preparation of supplies and materials handled by personnel brought into the controlled area.
Another common organism group recovered from sterility samples and controlled areas are soil organisms. This includes members of the bacterial genus Bacillus and fungal organisms like Aspergillus and Cladosporium. If these microorganisms are found, it may indicate improper cleaning procedures, technicians tracking in contaminants on their shoes from outdoors, or failure to properly seal a controlled area, causing dust and debris from outside to be drawn in.
Water-borne organisms may also be found in compounded products. This list includes E. coli and Enterococcus. Recovery of these genera indicates a contaminated water source near the controlled area, or the water used to clean or compound is not suitable for the process.
Knowing the identity of the organism is the only way to determine how the contamination occurred, where the contaminant came from, and how to prevent it from entering a future drug product. Pharmacists can determine the likely origin of an identified organism by testing and consulting literature or a trained microbiologist. The specific identity of microorganisms recovered from a contamination also assists pharmacists in the development, regular use, and continued improvement of cleaning and sanitization plans. Compounders and testing labs must work together to generate reliable sterility testing results and examine test failures to ensure quality end products for patients.