Antibiotic Susceptibility Profile of Clostridium Difficile Bacteria Isolated from Older Residents of a Nursing Home in Iran

Objectives: Clostridium difficile (C. diff) is a gram-positive anaerobic bacterium knwon as the most common cause of nosocomial diarrhea in nursing homes. The antibiotic susceptibility profile is the basic way for successful treatment due to antimicrobial resistance. This present study aims to assess the antibiotic susceptibility profile of C. diff isolated from older residents of a nursing home in Tehran, Iran. Methods & Materials: Forty-two isolates of C. diff were used in this study collected from 289 residents of Kahrizak Nursing Home. Antibiotic susceptibility testing was conducted by using disk-diffusion method, agar dilution method, and Epsilometer test (E-test). Results: All C. diff strains were susceptible to Metronidazole, Vancomycin, Rifampicin, Linezolid and Tigecycline. By using the disk-diffusion method, the highest rate of resistance was related to Clindamycin (100%), Levofloxacin (96.2%), Imipenem (81%), Azithromycin (61%) and Erythromycin (54.8%). All C. diff strains were susceptible to Metronidazole under E-test. Furthermore, 100% and 59.5% of strains were susceptible to Vancomycin and Erythromycin, respectively under agar dilution test. Conclusion: C. diff strains are sensitive to Vancomycin and Metronidazole. These two antibiotics can be used to treat C. diff infections in older adults. The disk diffusion method can be used as a screening test to determine antibiotic resistance.