Combined ceftazidime and amikacin resistance among Gram-negative isolates in acute-onset postoperative endophthalmitis: prevalence, antimicrobial susceptibilities, and visual acuity outcome

Abstract

BackgroundThe purpose of this study is to evaluate the prevalence, antimicrobial susceptibilities, and visual acuity outcome of acute-onset postoperative Gram-negative bacterial endophthalmitis cases resistant to both ceftazidime and amikacin seen between 2005 and 2010 at L. V. Prasad Eye Institute, a tertiary care ophthalmic Centre in South India. Medical records of all patients with Gram-negative bacterial endophthalmitis resistant to both amikacin and ceftazidime between 1 January 2005 and 31 December 2010 were reviewed in this non-comparative, consecutive, retrospective case series. Favorable outcome was defined as a best-corrected visual acuity of ≥20/200.ResultsSixty five (39.6%) of 164 culture-positive postoperative endophthalmitis were caused by Gram-negative organisms. Among these 65 isolates, 32 (49%; 95% confidence interval (CI) 37% to 61%) were resistant to ceftazidime, 17 (26%; 95% CI 15% to 37%) to amikacin, and 12 (18.5%; 95% CI 9% to 27%) to both ceftazidime and amikacin. Eight Pseudomonas isolates, three Enterobacter isolates, and one Haemophilus isolate were resistant to both ceftazidime and amikacin. The isolates were sensitive to fluoroquinolones (42%) and imipenem (50%). Presenting visual acuity was light perception in 10 (83.3%) cases. A final visual acuity ≥20/200 was achieved in 5/12 (41.7%) of these patients.ConclusionIn the current study, Pseudomonas was the most common Gram-negative bacteria resistant to both amikacin and ceftazidime. The emergence of multidrug-resistant bacteria causing endophthalmitis is a matter of concern in India. Alternative antibiotics like imipenem or fluoroquinolones may be considered for the management of these resistant organisms.

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?

“…Jindal et al have reported 32/65 (49 %) GNB isolates from patients with acute onset post-operative endophthalmitis are resistant to ceftazidime [15]. The same groups of authors have reported 22 % of GNB isolated from patients with open globe injuries are resistant to ceftazidime [16].…”

“…Five isolates of Pseudomonas species which are resistant to ceftazidime are susceptible to amikacin. Jindal et al have reported low resistant to amikacin (26 %) compared to ceftazidime (49 %) in GNB isolates [15]. Although there are reports on low resistance to amikacin compared to ceftazidime in GNB, intravitreal amikacin injection is associated with macular toxicity.…”

Reply

“…Jindal et al previously administered intravitreal imipenem for MDR P. aeruginosa , and Arora et al have now demonstrated intravitreal piperacillin-tazobactam as an alternative. 2,7 However, the poor outcomes in this latest outbreak unfortunately confirm that outcomes in these cases remain poor despite early and appropriate treatment.…”

Acute-onset postoperative endophthalmitis caused by multidrug-resistant Klebsiella pneumoniae

“…It acts by inhibiting cell wall synthesis of various Gram-positive and Gram-negative bacteria. It is stable to hydrolysis by the common plasmid-mediated β-lactamases produced by various bacteria and lacks cross-resistance with penicillins and third-generation cephalosporins 11. One case series reported use of intravitreal imipenem in the treatment of endophthalmitis caused by Acinetobacter baumannii .…”