An outbreak of post-cataract surgery endophthalmitis caused by Pseudomonas aeruginosa.
OBJECTIVE
Infectious endophthalmitis is among the most serious complications of cataract surgery. Gram-negative bacteria, including Pseudomonas aeruginosa, are responsible for less than 30% of cases; however, their rapidity of infection and virulence often results in poor visual outcome despite prompt antibiotic treatment. The purpose of this study was to investigate an outbreak of post-cataract surgery P. aeruginosa endophthalmitis in India.


METHODS
Hospital-based case series.


METHODS
Twenty patients with acute postoperative endophthalmitis who underwent cataract surgery at one of the peripheral centers of Joseph Eye Hospital, Tiruchirapalli, Tamil Nadu, India, from February 23 to April 2, 2008.


METHODS
Vitreous aspirates and environmental surveillance specimens were inoculated for culture. Antibiotic susceptibility testing was performed by agar diffusion method. Polymerase chain reaction (PCR) with enterobacterial repetitive intergenic consensus (ERIC) primers (ERIC-PCR) was used to establish the clonal relationship between clinical and environmental isolates.


METHODS
Post-cataract surgery P. aeruginosa endophthalmitis.


RESULTS
Pseudomonas aeruginosa was isolated from 20 eyes with postoperative endophthalmitis, the phacoemulsifier's internal tubes, the povidone-iodine solution, and the operating theater air-conditioning system. All strains were multidrug-resistant to cefazolin, chloramphenicol, tetracycline, aminoglycosides, and fluoroquinolones; conversely, most of them were susceptible to polymyxin B. Polymerase chain reaction with enterobacterial repetitive intergenic consensus primers disclosed 2 major clusters: six genetically identical clinical isolates shared 94% of similarity with the air-conditioning isolate; 11 other clinical isolates had 88% of similarity with the former strain. Despite the prompt use of intravitreal antibiotics, 10 patients had evisceration or phthisis of the affected eye.


CONCLUSIONS
The outcome of cataract surgery-related P. aeruginosa endophthalmitis is poor. The detection of multidrug-resistant isolates is a serious problem, jeopardizing an appropriate choice of treatment. Polymerase chain reaction with enterobacterial repetitive intergenic consensus results strongly suggest that the main source of infection in this outbreak was the contaminated air-conditioning system. Polymerase chain reaction with enterobacterial repetitive intergenic consensus is an inexpensive, fast, reproducible, and discriminatory DNA typing tool for effective epidemiologic surveillance of clinical and environmental isolates of P. aeruginosa.
Pinna
Antonio
A
Institute of Ophthalmology, University of Sassari, Sassari, Italy. apinna@uniss.it
Usai
Donatella
D
Sechi
Leonardo A
LA
Zanetti
Stefania
S
Jesudasan
Nelson C A
NC
Thomas
Philip A
PA
Kaliamurthy
Jayaraman
J
D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002387:Cataract Extraction; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D009877:Endophthalmitis / Q000453:epidemiology* / Q000382:microbiology / Q000628:therapy; D017234:Eye Evisceration; D015818:Eye Infections, Bacterial / Q000453:epidemiology* / Q000382:microbiology / Q000628:therapy; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology / Q000628:therapy; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000302:isolation & purification; D014822:Vitreous Body / Q000382:microbiology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial