Quantitative and qualitative evaluation of microorganism profile identified in bioburden analysis in a biopharmaceutical facility in Brazil: Criteria for classification and management of results

Abstract

Microbiological contamination may cause microbial proliferation and consequently additional problems for pharmaceutical companies through production stoppage, product contamination, investigations of process deviations, out-of-specification results and product disposal. This is one of the major concerns of the regulatory health agencies. Microbiological load (bioburden) may represent a potential risk for patients if the sterilization process is not effective and/or due to the production of toxins. Although bioburden can be eliminated by terminal sterilization or filtration processes, it is important to monitor the amount and determine the identity and characteristics of the microorganisms present prior to final processing. The application of microorganism identification systems is crucial for identifying the type of contamination, which can be extremely useful for investigating. The aim of this study was to evaluate the profiles of microorganisms identified in bioburden assays from solutions, culture medias, and products (SCP) from a pharmaceutical industry facility. From 2018-2020, a total of 1,078 samples from 857 different lots of SCP were analyzed and isolated microorganisms were identified. A prefiltering step was included after March 2020, in order to reduce the bioburden before sterilizing filtration. Criteria for the definition and management of microorganisms identified were evaluated after an integrative bibliographic review, and three groups were proposed (critical, objectionable, and nonobjectionable microorganisms). For the samples that did not include prefiltering (n=636), 227 (35.7%) presented microbial growth. For those that included prefiltering, before prefiltering (n=221), 60.6% presented microbial growth, and after prefiltering, this value was reduced to 4.1%, which can be attributed to a contamination during the sampling or a wrong filtering. From the samples that presented microbial growth, 678 microorganisms were identified as bacteria and 59 as molds and yeasts. A total of 120 microorganisms (56 and 27 Gram-positive and negative bacteria, respectively, 31 yeasts, and six filamentous molds) could not be identified, and the remaining microorganisms were classified as objectionable (n=507; 82.2%), nonobjectionable (n=103; 16.7%) and critical (n=7; 1.1%). Most of the bioburden species (>80.0%) were considered objectionable microorganisms. A process for classification and management of bioburden analysis results based on a literature review of pathogenic and physiological characteristics of the microorganisms was proposed.