SES202a - The Costs of Microbial (Mis) Identifications

When contamination events occur, it is critical to quickly and accurately identify the source of contamination so effective corrective and preventive actions can be implemented. Currently available methods of identification range from genotypic to phenotypic, with 16S rRNA gene sequencing being the gold standard for microbial identifications. There is very little complexity in the data from phenotypic systems and the methods are highly error prone, variable, and subjective. This microbial investigation case study examines the challenges and consequences of inaccurate microbial identification methods. The identification of a Gram-positive organism during an endotoxin out-of-specification event, not surprisingly, led the company down an erroneous investigation path. Although an extensive review of historical environmental monitoring tracking and trending data was performed, an initial incorrect microbial identification proved that exercise futile. After three discarded batches, production line work stoppages, and countless months spent sampling and cleaning equipment, DNA sequencing of the offending isolate revealed a Gram-negative organism. This finding led the company down the correct path to a root cause and lessons learned regarding accurate microbial identification methods.