Host factors are more important in predicting recurrent Clostridium difficile infection than ribotype and use of antibiotics

OBJECTIVE

A frequent complication of Clostridium difficile infection (CDI) is recurrent disease. The aim of this study was to determine whether early recurrence risk was higher after infection with ribotype 027 (outbreak strain) compared with infection with endemic strain types of C. difficile.

METHODS

Consecutive patients diagnosed with CDI between May 2013 and March 2014 were included (outbreak strain, and non-outbreak strains). Patients who developed recurrent CDI within 30 days after completion of CDI treatment, were compared with patients without a recurrence. Medical charts were reviewed for demographic and clinical characteristics. General practitioners were contacted to complete data about the occurrence of recurrent CDI, and the use of medication after hospital discharge.

RESULTS

In total, 135 patients were at risk for the development of recurrent CDI; 74 patients were infected by ribotype 027, and 61 patients by other ribotypes. Thirty-nine patients (29%) developed recurrent CDI within 30 days after completion of CDI treatment. In multivariable analysis, age ≥70 years (HR 3.05, 95% CI 1.54-6.03), and a duration of CDI treatment ≥11 days (HR 1.92, 95% CI 1.00-3.69) were clearly associated with recurrence; infection with ribotype 027 showed a HR of 1.72 (95% CI 0.88-3.33).

CONCLUSION

During this outbreak of C. difficile in a tertiary care centre, age and a prolonged duration of CDI therapy (which is most likely a marker of underlying disease severity) were the main risk factors for recurrent CDI. This points to host factors as more important predictors for recurrent CDI than strain type or antibiotic use.

Effect of low molecular weight organic acids on the uptake of 226Ra by corn (Zea mays L.) in a region of high natural radioactivity in Ramsar-Iran

To study the benefit of including citric and oxalic acid treatments for phytoremediation of ²²⁶Ra contaminated soils a greenhouse experiment with corn was conducted. A soil was sampled from a region of high natural ²²⁶Ra radioactivity in Ramsar, Iran. After cultivation of corn seed and using organic acid treatments at 1, 10 and 100 mM concentrations, plants (shoots and roots) were harvested, digested and prepared to measure ²²⁶Ra activity. Simultaneously, sequential selective extraction were performed to estimate the partitioning of ²²⁶Ra among geochemical extraction. Results showed that the maximum uptake of ²²⁶Ra in plants was observed in citric acid (6.3%) and then oxalic acid (6%) at 100 mM concentration. These treatments increased radium uptake by a factor of 1.5 than the control. Enhancement of radium uptake by plants was related to soil pH reduction of organic acids in comparison to control. Also, the maximum uptake of this radionuclide in all treatments was obtained in roots compared to shoots. ²²⁶Ra fractionations results revealed that 91.8% of radium was in the residual phase of the soil and the available fractions were less than 2%. As the main percent of ²²⁶Ra was in the residual phase of the soil in this region, it seems that organic acids had not significant effect on the uptake of ²²⁶Ra for phytoremediation by corn in this condition.