Objectives: Our goals were to study the molecular epidemiology and the antimicrobial susceptibilities of C.difficile strains and the prevalence of the epidemic clone BI/NAP1/027 in Israel.
Methods: A prospective national survey conducted in January-February 2014. Six general hospitals (GH) across Israel, and long-term care facilities (LTCF) submitted all adult stool samples tested positive for C. difficile toxins. C.difficile toxigenic cultures were identified by morphology and PCR for tpi, tcdA & tcdB genes. Antimicrobial susceptibility testing was done for vancomycin, metronidazole and moxifloxacin (EUCAST recommendations). Identification of BI/NAP1/027 was by PCR for the 18-bp deletion in the tcdC gene and the cdtB gene and PCR Ribotyping. Non-027 isolates were typed by PCR and sequencing of the variable region of the slpA gene (Kato`s nomenclature) and by Ribotyping.
Results: 211/217(97.2%) C.difficile isolates were recovered. Ribotype 027 was the most common type, with 65 samples (31.8%), found in all except one center and was predominant in three GH and LTCF`s with the highest incidence of C.difficile infections (CDI). Other common strains were slpA types cr-02 (n=45), hr-02 (n=19), and hr-05 (Ribotype 014, n=13). Vancomycin MIC values>2 mg/L were in the 2 most common strains, 027 (57/65, 87.7%) and cr-02 (40/45, 88.8%). Metronidazole MIC values>2 mg/L were 29/65 in the 027 strains (44.6%) and 8/45 in the cr-02 strains (17.8%).
Conclusions: The epidemic clone, Ribotype 027, characterized by diminished susceptibility to vancomycin and metronidazole, has disseminated across Israel and is now the most common clone, especially in centers with high incidence of CDI.
