Browsing by Subject "disinfection"

A clean area is an area isolated from its environment to prevent contamination of final product during aseptic processing. The clean area can be divided into four different grades from A to D, which all have different cleanliness standards. Grade A is the highest grade where preparing products that are not terminally sterilized must be performed. Airlocks are located between different grades to prevent free airflow, and enable necessary precautions, such as putting on protective garments and disinfecting material surface. These procedures reduce risk of contamination of the higher grade. The purpose of this study was to create a protocol to help evaluate material disinfection and transfer processes in the hospital pharmacy of Turku University Central Hospital and to determine surface bioburden of material stored in the grade C area. Surface samples of the examined material were taken in accordance with in-house guidelines by using contact plates and swabs depending on the surface of the material examined. After incubation, colony forming units were counted. Samples were taken from primary packages of ingredients and equipment stored in grade C area, as well as from material transfer boxes and cut flush plastic folders used in the clean area. Samples were taken both before and after routine disinfection of this material. 45 % of the samples taken before disinfection were contaminated. The lowest contamination rates were observed from items made from glass and those that were stored in their secondary package. In five plates grew more than 25 colonies, of which two had biofilm covering the whole surface of the plate. These samples were taken from larger plastic items, such as an infusion bag and a plastic folder. High bioburden is possible on the surface of material stored in grade C clean room, despite precautions. 25 % of the samples taken after routine disinfection were contaminated with a maximum of two colonies per plate. Despite disinfection, viable microbes may remain on the surface of material. Material with risk of high bioburden were selected for the protocol. Items were disinfected and transferred to grade B area as a simulation of normal processes. Different operators performed the protocol a total of eight times. 14 % of samples were contaminated with a maximum of two colonies per plate, except for one plate with 15 colonies. This repetition exceeded the limits set for the protocol. One repetition had zero contaminated samples. The bioburden of material surface after disinfection is affected by operators, cleanliness of the grade C area, and manipulation of the storage. A high bioburden increases risk of unsuccessful disinfection, and recontamination is possible in a non-sterile environment. Bacillus and Staphylococcus -species were identified from the samples taken during the protocol. Bacillus-species are usually isolated from soil, can tolerate harsh and low nutrient environments, and can form spores. Staphylococcus-species are part of the human skin microbiome. Microbes inside clean area are originated from personnel or surface of material transferred there. Material surface bioburden creates a contamination risk of aseptically prepared products, and thus material transfer and disinfection are critical stages during aseptic processing.

Tässä työssä käytettiin pohjana aikaisemmin julkaistua työtä (Nuanualsuwan ja Cliver, 2002), ja tarkoituksena oli tutkia työssä kuvatun menetelmän soveltuvuutta noroviruksen havaitsemiseen sekä sitä, kuinka erilaiset desinfektioaineet tehoavat noroviruksen eliminoinnissa. Menetelmä perustuu esikäsittelyyn, jossa ennen reaaliaikaista RT-PCR geenimonistusta lisätään näytteisiin proteinaasi K:ta ja ribonukleaasia (RNAsi). Esikäsittelyllä on tarkoitus poistaa vaurioituneet ei-infektiiviset viruspartikkelit ja genomit näytteestä, joka helpottaisi ihmiselle vaarallisen noroviruksen tunnistamista. Norovirusta sisältäviä näytteitä analysoitiin reaaliaikaisella RT-PCR:llä nukleiinihapposaostuksen jälkeen. Tulokset vahvistivat mm. etanolin ja kloorin tehon noroviruksen eliminoinnissa. Työssä huomattiin myös, että monet aineet jättivät jälkeensä suuren määrän inaktivoitua virusta, mikä on aikaisemmin saattanut johtaa esimerkiksi etanolin tehon aliarviointiin. Menetelmän käyttökelpoisuus sai myös vahvistuksen, mutta osoitti, että menetelmässä on vielä runsaasti kehittämisen varaa. Esikäsittelymenetelmiä tulisi kehittää spesifisemmiksi jotta niitä voisi hyödyntää käytännössä esimerkiksi epidemioiden yhteydessä ja tutkittaessa uusia desinfektioaineita.