A comparison of common trends of microorganisms isolated from NHS aseptic manufacturing units in the North of England
28 October 2018Courtney Smith , Vicky Tickle, Wayne Goddard
- This research aims to identify the most common micro flora found in aseptic units in the North of England, comparing them to 2016 data.
Bacillus spp. was the most common isolate found, despite the increased use of sporicidal agents following 2015 Q&As.
- The use of VHP gassing and triple wrapped items should strongly be considered in order to minimise the risk of micro-bacterial contamination.
Recent MHRA Q&A 2015 regulations state that a sporicidal agent is now required in the item transfer process, where this does not cause detrimental effects to the product being manufactured. This process aims to eliminate the presence of spore forming organisms in aseptic manufacturing units. The effectiveness of this is being evaluated by building a portfolio of the micro flora present in each individual unit.
400 isolates were identified from 329 environmental monitoring excursion results. This information was collected between January and June 2017 from several NHS aseptic manufacturing units from the North of England. Identifications were performed on a Matrix Assisted Laser Desorption/Ionisation Time of Flight (MALDI-TOF) based at Stockton Quality Control Laboratory. These results were then compared to a comparison data set from 2016.
Overall, the total number of isolates identified was very similar to 2016. The isolate found in
the highest numbers was Bacillus spp., similar to 2016 results. There was a reduction in spore forming organisms identified in both pharmacy and medical physics units who have
and have not implemented the use of sporicidal agents; although this reduction is greater in units not using a sporicide.
The fact that Bacillus spp. remains the most common organism identified in aseptic manufacturing units suggests that operator technique is an issue and cannot be standardised. This therefore highlights the importance of consideration of VHP decontamination and the use of triple wrapped items, despite the cost implications. If this is not a viable option there is a clear requirement for regular item transfer competencies for all operators and assistants, ensuring sufficient item coverage and contact time.
Medical physics units; who are not using a sporicidal agent, saw a greater reduction of spore forming organisms, this may have resulted from the added alcohol spray and wipe stage in the transfer phase to manually remove these organisms. The continued presence of non-sporing organisms, which should be readily eradicated by sporicidal agents, reinforces that operator technique and contact time are an essential factor for effectiveness of the process.