ABSTRACT
Purpose: To analyze the pattern of bacterial pathogens causing infective keratitis and their resistance to the recommended antibiotics over six years. Methods: It was a retrospective study of 9,357 cases of bacterial keratitis from January 2015 to December 2020, at a tertiary care ophthalmic center. A total of 9,547 corneal specimens were obtained from the study subjects. Demographic details of the patients, pathogenic bacteria isolated, and their antimicrobial susceptibility were noted and analyzed. Results: Bacterial pathogens were identified in 23.52% of the specimens. The most common isolates were coagulase?negative Staphylococci (60.75%), followed by Pseudomonas aeruginosa (14.23%), Staphylococcus aureus (13.92%), gram negative bacilli of the family Enterobacterales (8.64%), Streptococcus spp. (1.72%), Acinetobacter spp. (0.13%), and other non?fermenting gram?negative bacilli (0.57%). In Staphylococci, 55–80% of isolates were resistant to erythromycin, and 40–70% to fluoroquinolones, while no resistance was observed against vancomycin. 40–60% of isolates of P. aeruginosa were resistant to cephalosporins, 40–55% to fluoroquinolones, and 30–60% to aminoglycosides. Also, 40–80% of isolates of Enterobacterales were resistant to cephalosporins, and 50–60% to fluoroquinolones. Most gram?negative isolates were susceptible to carbapenems and polymyxin B. Conclusion: To the best of our knowledge, our study is the largest compilation of microbiological profile of bacterial keratitis from North India. It highlights the current trend of the bacterial pathogens that cause infectious keratitis. Staphylococci and Pseudomonas were found to be the most common pathogens. Increased resistance was seen against some of the commonly prescribed empirical antibiotics. Such evidence is useful for restructuring the empirical prescription practices from time to time.
ABSTRACT
Purpose: Real?life comparison of three intravitreal drug regimens used in cases of endophthalmitis at a tertiary care center in India. Methods: In this prospective, comparative study, patients of bacterial endophthalmitis were grouped according to intravitreal antibiotic drug regimens into Group 1 (ceftazidime and vancomycin), Group 2 (piperacillin + tazobactam and vancomycin), and Group 3 (imipenem and vancomycin). Forty?eight hours after injection nonresponding/worsening patients underwent vitrectomy. Vitreous samples were subjected to microbiological and pharmacokinetic tests. Results: A total of 64 patients were included and divided into Group 1: 29, Group 2: 20, and Group 3: 15 cases. Also, 75% of patients were post?surgical endophthalmitis, whereas 25% were post?traumatic. Improvement in vision (V90?0) and vision at 3 months (V90) were comparable between the three groups. Visual recovery was poorer in post?traumatic cases. In post?surgical cases, visual recovery was poorer in those presenting beyond 72 h of onset of symptoms (P = 0.0002). Polymerase chain reaction (PCR) positivity (66%) was higher than BACTECTM (33%) and culture (14%). Antibiotic resistance was comparable amongst the three groups. Most patients (62/64) further underwent vitrectomy. Ceftazidime and vancomycin achieved vitreous concentrations more than the minimum inhibitory concentration (MIC) at 48 h after the first injection. Conclusion: The choice of antibiotics did not affect the rate of vitrectomy and final vision in a real?life scenario. Ceftazidime and vancomycin can still be used as first?line intravitreal antibiotics owing to their comparable microbial sensitivity profile and adequate ocular bioavailability