Severe Clostridium difficile infection in New Zealand associated with an emerging strain, PCR-ribotype 244.

Aim: To compare disease severity and clinical outcome of Clostridium difficile infection (CDI) due to PCR-ribotype (RT) 244 with CDI due to other strains present in Auckland.

Method: A retrospective, case-control study was conducted. Ten cases with CDI due to RT 244 were compared with 20 controls infected with other C. difficile strains. RT 244 isolates were further analysed for antimicrobial susceptibility, binary toxin genes and mutations in the tcdC gene.

Results: Cases were significantly more likely to have severe disease than controls (OR 9.33; p=0.015). 50% of cases had community-associated CDI compared with 15% of controls (p=0.078). All RT 244 isolates produced binary toxin and had a single-base pair deletion in tcdC at position 117.

Conclusion: C. difficile RT 244 is a newly recognised strain in New Zealand. It shares several features that characterise RT 027. Given its propensity to cause severe community-associated disease, a heightened awareness of this strain is needed to ensure early testing in patients admitted from the community with identified risk factors for CDI.