Clostridium difficile and vancomycin-resistant enterococcus: the new nosocomial alliance

The aims of this study were to determine the frequency of the association between Clostridium difficile (C. difficile) and vancomycin-resistant Enterococcus (VRE) and delineate the role of C. difficile coinfection as a predictor of VRE infection versus colonization and adverse outcome.

Patients with both C. difficile colitis and VRE (CD/VRE) were compared to patients with VRE alone with regard to demographics, comorbidity, prior antibiotic therapy, and coinfection with methicillin-resistant Staphylococcus aureus and funguria. C. difficile as a predictor of VRE infection (VRE-I) versus colonization (VRE-C) and adverse outcome was also studied.

Eighty-nine patients with VRE infection or colonization were studied. This included 31 cases of VRE-I and 58 VRE-C. C. difficile was isolated in 17 (19.1%) of patients; of these C. difficile was isolated before VRE in 9 patients and after VRE in 8. The two groups did not differ in age, residence, or comorbidity. C. difficile coinfection was not predictive of VRE-I versus VRE-C, nor was it associated with increased length of stay or mortality. However, the mortality rates in both groups was high, around 30%. A significant association was noted between the use of vancomycin and metronidazole (before the isolation of VRE) and C. difficile coinfection (p = 0.03 and p = 0.001, respectively). A high incidence of nosocomial coinfection with methicillin-resistant Staphylococcus aureus, funguria, and gram-negative sepsis was noted in both groups; the association with funguria was statistically significant (p = 0.029).

In conclusion, C. difficile coinfection is common in patients with VRE infection or colonization and is significantly associated with other nosocomial dilemmas like funguria. This may result in the emergence of highly virulent pathogens including vancomycin-resistant C. difficile, posing new challenges in the management of nosocomial diarrheas.