Phenotypic and Genotypic Characteristics of Clostridium difficile Isolates in Patients with Type 2 Diabetes in Iran

Abstract

Purpose

This study aimed to investigate the phenotypic and genotypic characterization of Clostridium difficile isolates in type 2 diabetes patients with hospital-acquired diarrhea in four teaching hospitals in Isfahan, Iran.

Patients and Methods

A total of 104 hospitalized patients with type 2 diabetes and nosocomial diarrhea were included in the current study over a 2-year period (2015–2017). C. difficile isolates were characterized by conventional microbiological methods including the presence of toxin genes, antibiotic resistance testing and molecular methods including multilocus sequence typing (MLST) and random amplification of polymorphic DNA (RAPD).

Results

All 21 C. difficile isolates (20.2%) were detected from 104 studied patients. All isolates were susceptible to metronidazole and vancomycin. The antimicrobial resistance rates were distinctly higher for clindamycin and for moxifloxacin. Based on PCR amplification of tcdA and tcdB, 13 isolates (12.5%) carried both of these genes and were considered toxigenic. Thirteen toxigenic C. difficile strains were classified into two sequence types (STs), that is, ST54 and ST2 types. The RAPD-PCR amplification patterns of the detected toxigenic C. difficile revealed three distinct but related RAPD clusters. RAPD cluster 1 had the highest similarity with RAPD types 2 and 3.

Conclusion

A relatively high rate of CDI was observed in patients with type 2 diabetes and was associated with poorer health outcomes. These patients were exposed to multiple antibiotics and other therapeutic agents. We recommend close screening for the coexistence of CDI and type 2 diabetes in patients with diarrhea using a combination of conventional and molecular methods.

Keywords:

• Clostridium difficile
• hospital-acquired diarrhea
• RAPD
• MLST
• molecular characterization
• risk factor
• type 2 diabetes

Acknowledgments

We would like to thank Dr. Behrooz Ataei and Mr. Abbas Daei naser for their special co-operation in this study.

Ethics Approval and Consent to Participate

The study was approved by the human research ethics committee at Isfahan University of Medical Sciences and the study was carried out in accordance with the approved guidelines. All the patients provided written informed consent before study entry to their stool being collected and for use in this study. This study was conducted in accordance with the Declaration of Helsinki.

Data Sharing Statement

Data generated or analyzed during this study are available and some are included in this article. (Gel pictures of different PCRs are available).

Author Contributions

Shoaei P: contributed to acquisition of data and drafting the work and performed microbial and molecular experiments. Shojaei H: Designed and supervised the research, interpreted data, and co-wrote the paper. Shirani K: contributed to the conception of design and revising the draft critically and collected the patient data. All authors read and approved the final manuscript and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Disclosure

The authors have no conflicts of interest to declare regarding this paper.