Molecular characteristics and antibiotic resistance of Clostridioides difficile isolated from patients with diarrhea under 5 years old

  Objective  To understand the molecular characteristics and antibiotic resistance of Clostridioides difficile isolated from patients with diarrhea under 5 years old and provide basic data support for future research and clinical medication of C. difficile infection treatment in children.

  Methods  From 2010 to 2020, stool samples were collected from the patients with diarrhea under 5 years old in Yunnan, Shandong, Shanghai, Shaanxi, Henan and Beijing. Anaerobic culture was used to isolate and identify C. difficile strains. The multilocus sequence typing, tcdA, tcdB, binary toxin coding gene detection as well as ribotyping were performed by polymerase chain reaction (PCR). And the antibiotic resistance test was performed by Etest strips against 10 antibiotics.

  Results  Among the 99 strains of C. difficile isolated, ST3, ST54, and ST35 were the major types, tcdA + tcdB + cdtA - cdtB - was predominant type. Type RT012/ICDC007/ST54 was the most common type, and one highly virulent strain belonged to type RT078/ICDC028/ST11. All the strains were sensitive to vancomycin and metronidazole, and 7 isolates from children under 2 years old were confirmed as multidrug resistant (MDR). There were more tcdA-tcdB+isolates than tcdA+tcdB+isolates in MDR isolates (P=0.008).

  Conclusion  Most toxigenic C. difficile were isolated from patients with diarrhea under 5 years old, including ST37 (tcdA-tcdB+), and the hyper virulent C. difficile (RT078) from children under 2 years old. It is necessary to pay close attention to the protection both at family and in hospital. The detection, prevention and control of C. difficile infection needs to be further strengthened in the children by taking targeted measures.