Isolates and antibiotic resistance of culture-proven endophthalmitis cases presented to a referral center in Tehran

Abstract

Purpose:To evaluate the spectrum of organisms causing endophthalmitis and their resistance pattern to standard antimicrobial agents.Materials and Methods:Medical records of culture positive eyes treated at Rassoul Akram Hospital for endophthalmitis during the past 5 years were reviewed. Specimens were obtained during pars plana vitrectomy or vitreous tap.Results:Sixty-five isolates including 36 (55.4%) gram-positive organisms, 28 gram-negative organisms (43.1%), and 1 (1.5%) fungus were studied. The most common organism identified was Coagulase-negative staphylococcus in 16 eyes (24.6%). Among the antibiotics available for intravitreal injection, the least antibiotic resistance was for vancomycin in gram-positive organisms and amikacin and ceftazidime in gram-negative isolates.Conclusions:Gram-positive isolates were the most prevalent organisms; however, a high isolation rate for gram-negative organisms was obtained. Considering that no single antibiotic provides coverage for all of the organisms, a combination therapy using vancomycin/amikacin or vancomycin/ceftazidime seems to be useful as the initial empiric treatment of suspected bacterial endophthalmitis.

Susceptibility of bacterial isolates to vancomycin and ceftazidime from patients with endophthalmitis: Is there a need to change the empirical therapy in suspected bacterial endophthalmitis?

“…Another study by Sharma et al reported 4/11 GNB isolated from patients with endophthalmitis are resistant to ceftazidime [10]. Study from Tehran by Falavarjani et al has reported low resistance of ceftazidime (10 %) in GNB [11]. Schimel et al from USA reviewed the spectrum and susceptibilities of isolates from patients with endophthalmitis and found all GNB (100 %) susceptible to ceftazidime [9].…”

“…The spectrum and antibiotic susceptibility of organisms isolated from patients with endophthalmitis vary by region and country. Several reports have shown that all the Gram positive bacterial isolates are susceptible to vancomycin [8][9][10][11] except few cases of endophthalmitis with vancomycin resistant Enterococcus species [12,13]. Khera et al from Hyderabad, India have shown that 1.5 % of the total Gram positive isolates are resistant to vancomycin [14].…”

PCR Detection and Identification of Bacterial Contaminants in Ocular Samples from Post- Operative Endophthalmitis

“…[ In their investigation the most common organism was Coagulasenegative staphylococcus [27]. In another study which was conducted in 2012, Staphylococcus, Streptococcus, Bacillus cereus and Pseudomonas aeruginosa were detected in Iranian endophthalmitis specimens [28].…”

Endophthalmitis in the Tertiary Referral Center in Iran; Etiology and Causative Organisms

“…Somani et al 31 (Canada), Pei-Chang et al 32 (Taiwan), and Falavarjani et al 33 (Iran) reported that cataract surgery was the most common predisposing surgical procedure in postoperative endophthalmitis patients. Since cataract surgery is the most common intraocular surgery, most cases of post-operative endophthalmitis occur after cataract extraction.…”