Anaerobe opportunist Clostridium difficile causes the majority of hospital-acquired antibiotic-associated diarrhea. Infections can be severe because of its ability to withstand many antibiotics, to sporulate and to produce toxins (A, B and binary). In Sundsvall Hospital C. difficile is detected with real-time PCR, which targets the sequences of toxin B, binary toxin and a regulatory gene deletion seen in the virulent ribotype 027. All positive samples are stored frozen for one month, available for further analysis or outbreak investigation. The aim of this study was to investigate if temperature and transportation time may affect the viability of C. difficile, and the PCR-result. Frozen feces samples were cultivated, identified with MALDI-TOF and analyzed with real-time PCR after at least one month of storage. To simulate the effect of transportation time, samples were stored at 4-8°C for three and seven days before cultivation and identification. Controls were cultivated after freezing for comparison. Ninety percent of the frozen samples contained viable C. difficile. Discrepancies between PCR-results were found for two of the oldest samples collected (six months), which turned negative. Fresh samples showed lower amount of viable C. difficile after three days (50 %) than after seven days (60 %) of storage, perhaps because of competition with other bacteria and sporulation. The frozen control group contained a higher viable amount, 75 %. The results indicate that C. difficile tolerates to be stored at low temperatures as practiced today at the laboratory. Transportation time seem to affect the outcome of cultivation, but not the PCR-result.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-295127 |
| Date | January 2016 |
| Creators | Hörnström, Eva |
| Publisher | Uppsala universitet, Institutionen för kvinnors och barns hälsa |
| Source Sets | DiVA Archive at Upsalla University |
| Language | Swedish |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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