Antibiotic Resistances and Molecular Characteristics of Clostridioides difficile in ICUs in a Teaching Hospital From Central South China.

Xiujuan Meng,Chenchao Fu,Xun Huang,Sidi Liu,Cui Zeng,Anhua Wu,Juping Duan,Chunhui Li,Ximao Wen,Zhong Peng,Yaowang Wang

doi:10.3389/fmed.2021.745383

Abstract

Clostridioides (C.) difficile is a major healthcare-associated pathogen inducing infectious diarrhea. Approximately 25–33% of patients with antibiotic-associated diarrhea (AAD) and 90% of patients with pseudomembranous enteritis are caused by C. difficile infection (CDI). Stool samples were collected from hospitalized adults with presumptive AAD in four nonneonatal intensive care units (ICUs). Diagnosis of CDI was based on both clinical symptoms and laboratory results. The stool specimens were transferred onto CDIF (C. difficile agar), and C. difficile was finally confirmed by the latex agglutination test. Toxin-producing genes tcdA (A), tcdB (B), and cdt (CDT) were detected by PCR, and all isolates were performed multilocus sequence typing analysis. The antibiotic susceptibility of C. difficile isolates was assessed by the agar dilution method. A total of 184 C. difficile were isolated from 857 specimens in our study, the isolation rate of C. difficile was 21.5% (184/857). The 184 C. difficile were isolated from 179 patients, among these 115 patients were toxin-positive, giving the incidence of CDI being 58.0/10,000 patient days in the four ICUs. Among these 115 toxin-positive C. difficile isolates, 100 (87.0%) isolates produced two toxins (A+B+CDT-), three (2.6%) isolates were A+B+ with binary toxin-producing (A+B+CDT+), and 12 (10.4%) isolates only produced one toxin (A-B+CDT-). A total of 27 sequencing types (STs) were obtained. The most prevalent was ST3 (34 isolates), followed by ST39 (27 isolates), ST54 (19 isolates), ST26 (16 isolates), ST35 (15 isolates), and ST2 (13 isolates). All the ST26 isolates were nontoxigenic. Meanwhile, five STs were newly discovered. Although multidrug resistance was present in ≥50% of these C. difficile isolates, all of them were susceptible to tigecycline, fidaxomicin, metronidazole, and vancomycin. In conclusion, C. difficile isolates producing two toxins (A+B+CDT-) were dominant in our hospital. The most prevalent was ST3, and all ST26 isolates were NTCD. Although multidrug resistance was present in ≥50% of the C. difficile isolates, metronidazole, tigecycline, fidaxomicin, and vancomycin were still effective treatments for CDI in our hospital.

Highlights

Clostridioides difficile is a major healthcare-associated pathogen inducing infectious diarrhea, which is responsible for a wide spectrum of diseases, ranging from mild diarrhea to fulminant colitis and even death [1]
The susceptibility of C. difficile isolates to 11 types of antibiotics, namely, chloramphenicol (CHL), metronidazole (MTZ), vancomycin (VAN), rifaximin (RFX), fidaxomicin (FDX), ampicillin (AMP), clindamycin (CLI), tigecycline, fusidic acid (FSA), levofloxacin (LVX), and tetracycline (TE) were tested by agar dilution according to the procedures of the Clinical and Laboratory Standards Institute (CLSI-M100-S29)
Among the total 774 patients with diarrhea, 179 patients were positive for C. difficile culture, while the other 595 patients were C. difficile negative (Figure 1)

Summary

Introduction

Clostridioides difficile is a major healthcare-associated pathogen inducing infectious diarrhea, which is responsible for a wide spectrum of diseases, ranging from mild diarrhea to fulminant colitis and even death [1]. 25–33% of patients with antibiotic-associated diarrhea and 90% of patients with pseudomembranous enteritis are due to C. difficile infection (CDI) [2]. The CDI has been associated with increased morbidity and decreased quality of life in patients, accompanied by prolonged hospitalization [3,4,5]. The incidence of CDI has been reported to increase in various countries. China, and several other countries have reported an incidence rate of 17.1/10,000 admission to hospitals [6]. CDI has been recognized to initiate from unusual antibiotic exposure of intestinal microbiota. The most important risk factor for CDI is broad-spectrum antimicrobial drugs that induce intestinal microfloral dysbiosis [8]

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Discussion

Conclusion