Microbiological Isolates and Antibiotic Susceptibilities in Cases of Posttraumatic Endophthalmitis: A 15-Year Review

الملخص EN

Purpose.

The objective of this study was to evaluate the microbiological spectrum and antibiotic susceptibilities of isolates in posttraumatic endophthalmitis over a 15-year period.

Methods.

A retrospective study of 3,163 posttraumatic endophthalmitis cases was conducted between July 2004 and July 2019.

The outcome measures included the microbiological spectrum and antibiotic susceptibilities.

Chi-squared tests were conducted to detect trends in changes in antibiotic sensitivity over the 15-year period.

P values of <0.05 were considered statistically significant.

Results.

Of the 3,163 cases of posttraumatic endophthalmitis, 1,003 culture-positive isolates were identified.

Among these, there were 848 (84.5%) Gram-positive isolates, 109 (10.9%) Gram-negative isolates, and 46 (4.6%) fungal isolates.

The most common isolates were Staphylococcal species.

There was a significant increase in the percentage of fungal isolates over the 15-year period (P=0.02).

Gram-positive organisms showed the greatest level of susceptibility to vancomycin (99.6%).

The susceptibilities of the 109 Gram-negative isolated organisms were as follows: levofloxacin (95.8%), meropenem (95.7%), ciprofloxacin (93.5%), tobramycin (90.8%), imipenem (88.9%), trimethoprim-sulfamethoxazole (TMP-SMX) (87.7%), ertapenem (80%), and ceftazidime (79.1%).

The susceptibility of Gram-positive organisms to several antibiotics, including levofloxacin (P=0.004), ciprofloxacin (P<0.001), and chloramphenicol (P=0.001) decreased over time, whereas the susceptibility to TMP-SMX increased over time (P<0.001).

The susceptibility of Gram-negative bacilli to ceftazidime decreased over time (P=0.03).

Conclusions.

Over the 15-year study period, most isolates were Gram-positive cocci, especially coagulase-negative staphylococci (CNS).

Vancomycin seemed to be the most effective antibiotic for Gram-positive bacteria.

Gram-negative bacteria appeared to be most susceptible to fluoroquinolones.

A number of antibiotics showed an increasing trend of microbial resistance.