Related Experiment Video
Updated: Jan 4, 2026
The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms
Published on: July 2, 2013
Outbreak of Multidrug-resistant Pseudomonas Aeruginosa Endophthalmitis Due to Contaminated Trypan Blue Solution
Pritam Bawankar1, Harsha Bhattacharjee1, Manabjyoti Barman1
1Department of Vitreo-Retina Surgery, Sri Sankaradeva Nethralaya, Guwahati, Assam, India.
Purpose:
To report the investigation of an outbreak of multidrug-resistant (MDR) Pseudomonas aeruginosa endophthalmitis in 13 patients after cataract surgery and to emphasize on the importance of clinical profile, risk factors, and treatment outcomes.
Methods:
This was a hospital-based, retrospective case study with 13 consecutive patients who had man- ual small-incision cataract surgery with intraocular lens (IOL) implantation and developed acute postoperative Pseudomonas aeruginosa endophthalmitis. The anterior chamber taps, vitreous aspirates, and environ- mental surveillance specimens were inoculated for culturing. Antibiotic susceptibility testing was performed using the agar diffusion method. Pulsed-field gel electrophoresis (PFGE) was used to determine the relation- ship between bacterial isolates recovered from study patients and contaminated surveillance samples.
Results:
Pseudomonas aeruginosa was isolated from all 13 eyes with acute postoperative endophthalmitis and the trypan blue solutions used during surgery. Sensitivity tests revealed that all isolates had an identical resistance to multiple drugs and were only susceptible to imipenem. Genomic DNA typing of Pseudomonas aeruginosa isolates recovered from patients and trypan blue solutions showed an identical banding pattern on the PFGE. Despite the prompt use of intravitreal antibiotics and early vitrectomy with IOL explantation in some patients, the outcome was poor in about 50% of patients.
Conclusion:
Positive microbiology and genomic DNA typing results proved that the contaminated trypan blue solutions were the source of infection in this outbreak. Postoperative endophthalmitis caused by Pseudomonas aeruginosa is often associated with a poor visual prognosis despite prompt treatment with intravitreal antibiotics.
Insights
A multidrug-resistant Pseudomonas aeruginosa outbreak caused endophthalmitis in 13 patients after cataract surgery. Contaminated trypan blue solution was identified as the source, leading to poor visual outcomes despite treatment.
Area of Science:
- Ophthalmology
- Infectious Diseases
- Microbiology
Background:
- Postoperative endophthalmitis is a serious complication following cataract surgery.
- Multidrug-resistant bacterial infections pose a significant challenge in clinical settings.
Purpose of the Study:
- Investigate a multidrug-resistant Pseudomonas aeruginosa endophthalmitis outbreak after cataract surgery.
- Identify risk factors and treatment outcomes in affected patients.
Main Methods:
- Retrospective case study of 13 patients with acute postoperative endophthalmitis.
- Microbiological analysis of ocular and environmental samples.
- Pulsed-field gel electrophoresis (PFGE) for bacterial isolate typing.
Main Results:
- Pseudomonas aeruginosa isolated from all affected eyes and trypan blue solutions.
- All isolates exhibited identical multidrug resistance, susceptible only to imipenem.
- PFGE confirmed identical banding patterns between patient and solution isolates.
- Poor visual outcomes observed in approximately 50% of patients despite prompt treatment.
Conclusions:
- Contaminated trypan blue solutions were identified as the source of the Pseudomonas aeruginosa outbreak.
- Pseudomonas aeruginosa endophthalmitis is associated with poor visual prognosis, even with timely intervention.
