Original Article

Toxin gene profiles and antimicrobial resistance of Clostridioides difficile infection: a single tertiary care center study in Iran


Background and Objectives: Due to the reduced susceptibility of clinical Clostridioides difficile strains in hospitals to various antimicrobial agents, the importance of antimicrobial susceptibility testing (ASTs) has increased. This study aimed to investigate the toxin gene profiles and the antimicrobial resistance of C. difficile isolated from hospitalized patients suspected of having Clostridioides difficile infection (CDI) in Tehran, Iran.
Materials and Methods: The stool samples were obtained from a hospitalized patients. The samples were shocked by alcohol and the patients cultured on cycloserine-cefoxitin-fructose agar in anaerobic Conditions. Toxin assay was performed for detection of toxinogenic isolates. An antibiotic susceptibility test was done. Furthermore, their genome was extracted for PCR to confirm C. difficile and detect toxin gene profile.
Results: Toxigenic C. difficile were identified in 21 of the 185 stool samples (11.3%). PCR detected seven toxin gene profiles; the highest prevalence was related to tcdA+B+, cdtA+B- toxin gene profile (57.1%). There were 14.3% and 28.6% resistant rates of the isolates towards vancomycin and metronidazole with the toxin gene profiles; tcdA+B+, cdtA±B+; and tcdA+B-, cdtA-B+. All resistant isolates to moxifloxacin, clindamycin, and tetracycline were belonged to the toxin gene profiles; tcdA+B+, cdtA+B+; tcdA+B+, cdtA+B-, and tcdA-B+, cdtA+B-.
Conclusion: Relative high resistance was detected towards metronidazole and vancomycin, although, still have acceptable activity for CDI treatment. However, a proper plan for the use of antibiotics and more regular screening of C. difficile antibiotic resistance seems necessary.

1. Papatheodorou P, Barth H, Minton N, Aktories K. Cellular uptake and mode-of-action of Clostridium difficile toxins. Adv Exp Med Biol 2018;1050:77-96.
2. Wang R, Suo L, Chen HX, Song LJ, Shen YY, Luo YP. Molecular epidemiology and antimicrobial susceptibility of Clostridium difficile isolated from the Chinese people's liberation army general hospital in China. Int J Infect Dis 2018;67:86-91.
3. Kouhsari E, Douraghi M, Barati M, Fakhre Yaseri H, Talebi M, Abbasian S, et al. Rapid simultaneous molecular stool-based detection of toxigenic Clostridioides difficile by Quantitative TaqMan Real-Time PCR assay. Clin Lab 2019;65: 10.7754/Clin.Lab.2018.180735.
4. Elliott B, Androga GO, Knight DR, Riley TV. Clostridium difficile infection: evolution, phylogeny and molecular epidemiology. Infect Genet Evol 2017;49:1-11.
5. Smits WK. Hype or hypervirulence: a reflection on problematic C. difficile strains. Virulence 2013;4:592-596.
6. Carson KC, Boseiwaqa LV, Thean SK, Foster NF, Riley TV. Isolation of Clostridium difficile from faecal specimens--a comparison of chromID C. difficile agar and cycloserine-cefoxitin-fructose agar. J Med Microbiol 2013;62:1423-1427.
7. Kouhsari E, Douraghi M, Krutova M, Fakhre Yaseri H, Talebi M, Baseri Z, et al. The emergence of metronidazole and vancomycin reduced susceptibility in Clostridium difficile isolates in Iran. J Glob Antimicrob Resist 2019;18:28-33.
8. Baghani A, Ghourchian S, Aliramezani A, Yaseri M, Mesdaghinia A, Douraghi M. Highly antibiotic-resistant Clostridium difficile isolates from Iranian patients. J Appl Microbiol 2018;125:1518-1525.
9. Persson S, Jensen JN, Olsen KE. Multiplex PCR method for detection of Clostridium difficile tcdA, tcdB, cdtA, and cdtB and internal in-frame deletion of tcdC. J Clin Microbiol 2011;49:4299-4300.
10. Clinical and Laboratory Standards Institute (CLSI). Performance standards for antimicrobial susceptibility testing. 28th ed. CLSI supplement M100. Wayne, PA: USA, 2018.
11. Karlowsky JA, Adam HJ, Kosowan T, Baxter MR, Nichol KA, Laing NM, et al. PCR ribotyping and antimicrobial susceptibility testing of isolates of Clostridium difficile cultured from toxin-positive diarrheal stools of patients receiving medical care in Canadian hospitals: the Canadian Clostridium difficile surveillance study (CAN-DIFF) 2013-2015. Diagn Microbiol Infect Dis 2018;91:105-111.
12. Stubbs S, Rupnik M, Gibert M, Brazier J, Duerden B, Popoff M. Production of actin-specific ADP-ribosyltransferase (binary toxin) by strains of Clostridium difficile. FEMS Microbiol Lett 2000;186:307-312.
13. The European Committee on Antimicrobial Susceptibility Testing-EUCAST. Breakpoint tables for interpretation of MICs and zone diameters. 2018.
14. Marroki A, Zúñiga M, Kihal M, Pérez-Martínez G. Characterization of Lactobacillus from algerian goat’s milk based on phenotypic, 16S rDNA sequencing and their technological properties. Braz J Microbiol 2011;42:158-171.
15. Honda H, Yamazaki A, Sato Y, Dubberke ER. Incidence and mortality associated with Clostridium difficile infection at a Japanese tertiary care center. Anaerobe 2014;25:5-10.
16. Hassan SA, Othman N, Idris FM, Abdul Rahman Z, Maning N, Abdul Rahman R, et al. Prevalence of Clostridium difficile toxin in diarhoeal stool samples of patients from a tertiary hospital in north eastern Penisular Malaysia. Med J Malaysia 2012;67:402-405.
17. Moukhaiber R, Araj GF, Kissoyan KA, Cheaito KA, Matar GM. Prevalence of Clostridium difficile toxinotypes in infected patients at a tertiary care center in Lebanon. J Infect Dev Ctries 2015;9:732-735.
18. Khoshdel A, Habibian R, Parvin N, Doosti A, Famouri F, Eshraghi A, et al. Molecular characterization of nosocomial Clostridium difficile infection in pediatric ward in Iran. Springerplus 2015;4:627.
19. Goudarzi M, Goudarzi H, Alebouyeh M, Azimi Rad M, Shayegan Mehr FS, Zali MR, et al. Antimicrobial susceptibility of Clostridium difficile clinical isolates in Iran. Iran Red Crescent Med J 2013;15:704-711.
20. Barbut F, Mastrantonio P, Delmée M, Brazier J, Kuijper E, Poxton I, et al. Prospective study of Clostridium difficile infections in Europe with phenotypic and genotypic characterisation of the isolates. Clin Microbiol Infect 2007;13:1048-1057.
21. Vindigni SM, Surawicz CM. C. difficile infection: changing epidemiology and management paradigms. Clin Transl Gastroenterol 2015;6(7):e99.
22. Kilic A, Alam MJ, Tisdel NL, Shah DN, Yapar M, Lasco TM, et al. Multiplex Real-Time PCR method for simultaneous identification and toxigenic type characterization of Clostridium difficile from stool samples. Ann Lab Med 2015;35:306-313.
23. Kouhsari E, Douraghi M, Fakhre Yaseri H, Talebi M, Ahmadi A, Sholeh M, et al. Molecular typing of Clostridioides difficile isolates from clinical and non-clinical samples in Iran. APMIS 2019;127:222-227.
24. Sholeh M, Krutova M, Forouzesh M, Mironov S, Sadeghifard N, Molaeipour L, et al. Antimicrobial resistance in Clostridioides (Clostridium) difficile derived from humans: a systematic review and meta-analysis. Antimicrob Resist Infect Control 2020;9:158.
25. Melillo KD. Clostridium difficile and older adults: what primary care providers should know. Nurse Pract 1998;23:25-26, 29 -30, 39-43; quiz 44-5.
26. Gardner E, Meghani N, Mancuso P, Thomson A. Recognizing metronidazole resistant C. difficile. Nurse Pract 2011;36:8-11.
27. Shayganmehr FS, Alebouyeh M, Azimirad M, Aslani MM, Zali MR. Association of tcdA+/tcdB+ Clostridium difficile genotype with emergence of multidrug-resistant strains conferring metronidazole resistant phenotype. Iran Biomed J 2015;19:143-148.
28. Leroi MJ, Siarakas S, Gottlieb T. E test susceptibility testing of nosocomial Clostridium difficile isolates against metronidazole, vancomycin, fusidic acid and the novel agents moxifloxacin, gatifloxacin, and linezolid. Eur J Clin Microbiol Infect Dis 2002;21:72-74.
29. Ackermann G, Degner A, Cohen SH, da Silva JA Jr, Rodloff AC. Prevalence and association of macrolide–lincosamide–streptogramin B (MLSB) resistance with resistance to moxifloxacin in Clostridium difficile. J Antimicrob Chemother 2003;51:599-603.
30. Cheng JW, Yang QW, Xiao M, Yu SY, Zhou ML, Kudinha T, et al. High in vitro activity of fidaxomicin against Clostridium difficile isolates from a university teaching hospital in China. J Microbiol Immunol Infect 2018;51:411-416.
31. Snydman DR, McDermott LA, Jacobus NV, Thorpe C, Stone S, Jenkins SG, et al. U.S.-based national sentinel surveillance study for the epidemiology of Clostridium difficile-associated diarrheal isolates and their susceptibility to fidaxomicin. Antimicrob Agents Chemother 2015;59:6437-6443.
32. Tickler IA, Goering RV, Whitmore JD, Lynn AN, Persing DH, Tenover FC, et al. Strain types and antimicrobial resistance patterns of Clostridium difficile isolates from the United States, 2011 to 2013. Antimicrob Agents Chemother 2014;58:4214-4218.
33. Mutlu E, Wroe AJ, Sanchez-Hurtado K, Brazier JS, Poxton IR. Molecular characterization and antimicrobial susceptibility patterns of Clostridium difficile strains isolated from hospitals in south-east Scotland. J Med Microbiol 2007;56:921-929.
34. Zheng L, Keller SF, Lyerly DM, Carman RJ, Genheimer CW, Gleaves CA, et al. Multicenter evaluation of a new screening test that detects Clostridium difficile in fecal specimens. J Clin Microbiol 2004;42:3837-3840.
35. Sadeghifard N, Salari MH, Ghassemi MR, Eshraghi S, Amin Harati F. The incidence of nosocomial toxigenic Clostridium difficile associated diarrhea in Tehran tertiary medical centers. Acta Med Iran 2010;48:320-325.
36. Dong D, Zhang L, Chen X, Jiang C, Yu B, Wang X, et al. Antimicrobial susceptibility and resistance mechanisms of clinical Clostridium difficile from a Chinese tertiary hospital. Int J Antimicrob Agents 2013;41:80-84.
37. Freeman J, Vernon J, Morris K, Nicholson S, Todhunter S, Longshaw C, et al. Pan-European longitudinal surveillance of antibiotic resistance among prevalent Clostridium difficile ribotypes. Clin Microbiol Infect 2015;21(3):248.e9-248.e16.
38. Peng Z, Addisu A, Alrabaa S, Sun X. Antibiotic resistance and toxin production of Clostridium difficile isolates from the hospitalized patients in a large hospital in Florida. Front Microbiol 2017;8:2584.
IssueVol 13 No 6 (2021) QRcode
SectionOriginal Article(s)
DOI https://doi.org/10.18502/ijm.v13i6.8081
Clostridioeides difficile; Multiplex-polymerase chain reaction; Toxin gene profiles; Antimicrobial resistance; Iran

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
Sholeh M, Kouhsari E, Talebi M, Hallajzadeh M, Godarzi F, Amirmozafari N. Toxin gene profiles and antimicrobial resistance of Clostridioides difficile infection: a single tertiary care center study in Iran. Iran J Microbiol. 2021;13(6):793-800.