Understanding the Non-Equivalency of Bio-Fluorescent Particle Counts versus the Colony-Forming Unit.

Adopting emerging microbiological methods is often desirable because it enables more advantageous, real-time monitoring practices. However, when the newer method measures contamination based on a different detection principle and provides results that are based on different units of measure, a paradigm shift is necessary. That shift can be one of the most difficult challenges in any such project and requires careful consideration. In this article, we explore the challenges presented by the bio-fluorescent particle counting (BFPC) technology, when considering that the traditional colony-forming unit (CFU) is the gold standard that any change is measured against. We examine why attempts to correlate newer units of measure used by biofluorescent particle counters, namely the auto-fluorescent units (AFUs), to the traditional CFUs are not necessarily appropriate. The article explores in depth why there is no consistent correlation factor between the two units of measure, and why that should not be a barrier to fully leveraging, implementing, and using such modern technologies in routine monitoring.

Challenges Encountered in the Implementation of Bio-Fluorescent Particle Counting Systems as a Routine Microbial Monitoring Tool.

The transition from traditional growth-based microbial detection methods to continuous bio-fluorescent particle counting methods represents a paradigm shift, because the results will be non-equivalent in terms of microbial counts, and a continuous, rather than periodic, data stream will be available. Bio-fluorescent particle counting technology, a type of rapid microbiological method, uses the detection of the intrinsic fluorescence of microbial cells to enumerate bioburden levels in air or water samples, continuously. The reported unit is commonly referred to as an autofluorescence unit, which is not dependent upon growth, as is the traditional method. The following article discusses challenges encountered when implementing this modern technology, and the perspective from a consortium of four industry working groups on navigating these challenges.

Multisite Qualification of an Automated Incubator and Colony Counter for Environmental and Bioburden Applications in Pharmaceutical Microbiology.

Traditional microbiological techniques have been used for well over a century as the basis for contamination testing of pharmaceutical products and processes. With more recent focus on faster product release and concerns around the integrity of the test data, new technologies have been implemented to detect and enumerate organisms faster and provide paperless processes to minimize data integrity issues. Manual colony counting technologies, where incubation is performed in a standard incubator, and the plate is manually transferred to the colony counter for a single read at the end of incubation, have been used for many years to reduce the potential for human error; however, they pose validation challenges due to poor counting accuracy. Colony counters that automatically perform both the incubation and enumeration functions (multiple enumeration calculations through the incubation phase) have recently been implemented for quality control (QC) laboratory analytical processes, supporting a cGMP environment. This article summarizes the findings of eight companies demonstrating the qualification of an automated colony counter technology to perform the majority of microbial tests required for QC, environmental monitoring, and bioburden for in-process, bulk drug substance, and water system testing. Comparable analytical performance and time to result data generated during individual studies at all companies allows the system to be qualified and implemented for cGMP processes while reducing data integrity risks.

A novel serine protease inhibitor as potential treatment for dry eye syndrome and ocular inflammation.

Dry eye syndrome (DES), a multifactorial disorder which leads to ocular discomfort, visual disturbance and tear film instability, has a rising prevalence and limited treatment options. In this study, a newly developed trypsin-like serine protease inhibitor (UAMC-00050) in a tear drop formulation was evaluated to treat ocular inflammation. A surgical animal model of dry eye was employed to investigate the potential of UAMC-00050 on dry eye pathology. Animals treated with UAMC-00050 displayed a significant reduction in ocular surface damage after evaluation with sodium fluorescein, compared to untreated, vehicle treated and cyclosporine-treated animals. The concentrations of IL-1α and TNF-α were also significantly reduced in tear fluid from UAMC-00050-treated rats. Additionally, inflammatory cell infiltration in the palpebral conjunctiva (CD3 and CD45), was substantially reduced. An accumulation of pro-MMP-9 and a decrease in active MMP-9 were found in tear fluid from animals treated with UAMC-00050, suggesting that trypsin-like serine proteases play a role in activating MMP-9 in ocular inflammation in this animal model. Comparative qRT-PCR analyses on ocular tissue indicated the upregulation of tryptase, urokinase plasminogen activator receptor (uPAR) and protease-activated receptor 2 (PAR2). The developed UAMC-00050 formulation was stable up to 6 months at room temperature in the absence of light, non-irritating and sterile with compatible pH and osmolarity. These results provide a proof-of-concept for the in vivo modifying potential of UAMC-00050 on dry eye pathology and suggest a central role of trypsin-like serine proteases and PAR2 in dry eye derived ocular inflammation.

Optimization and validation of an existing, surgical and robust dry eye rat model for the evaluation of therapeutic compounds.

The aim of this research was to optimize and validate an animal model for dry eye, adopting clinically relevant evaluation parameters. Dry eye was induced in female Wistar rats by surgical removal of the exorbital lacrimal gland. The clinical manifestations of dry eye were evaluated by tear volume measurements, corneal fluorescein staining, cytokine measurements in tear fluid, MMP-9 mRNA expression and CD3(+) cell infiltration in the conjunctiva. The animal model was validated by treatment with Restasis(®) (4 weeks) and commercial dexamethasone eye drops (2 weeks). Removal of the exorbital lacrimal gland resulted in 50% decrease in tear volume and a gradual increase in corneal fluorescein staining. Elevated levels of TNF-α and IL-1α have been registered in tear fluid together with an increase in CD3(+) cells in the palpebral conjunctiva when compared to control animals. Additionally, an increase in MMP-9 mRNA expression was recorded in conjunctival tissue. Reference treatment with Restasis(®) and dexamethasone eye drops had a positive effect on all evaluation parameters, except on tear volume. This rat dry eye model was validated extensively and judged appropriate for the evaluation of novel compounds and therapeutic preparations for dry eye disease.