Phenotypic Screening and Antibiogram of Infectious Ulcerative Keratitis Cases in Tripoli Eye Hospital, Libya

Aims: This study to investigate the most prevalent pathogens that cause corneal ulcer in Tripoli-Libya, and to recognize the antibiogram of the isolated pathogens

Study Design: This study was a prospective study performed in eye hospital (Zawyet-Aldahmany eye hospital).

Place and Duration of Study: It was conducted at the microbiology laboratory of the hospital over a year from December 2018 to January 2020, The overall size of the sample enrolled in this study was 50 inpatients in the admission department, which was taken according to the incidence of the corneal ulceration cases admitted to the hospital.

Methodology: The corneal scrapings and swabs were collected and subjected to microbiological examination. Demographic data and risk factors were collected for each patient. The antibiotic susceptibility of the bacterial microorganisms was determined by the Kirby-Bauer disk diffusion method, to identify the most appropriate antibiotic for each bacterial isolate.

Results: 60% of the patients were males, the mean age of the patients was 46.5 years, unilateral right eye keratitis was involved in (54%) of cases, trauma was the major risk factor (24%), followed by systemic disease (14%). Concerning the seasonal distribution of the cases between months, our study revealed that summer and winter seasons in Libya (January, July, August, and September) involved most of the cases, and interestingly, fungal keratitis (Aspergillus) was higher in (July, August), which is the summer season in Libya. The culture positive rate was (80%), of which (36%) were bacterial, and (22%) were fungal pathogens, and the other (22%) were mixed fungal and bacterial cultures. The most common bacterial isolate was (26%) P.aeruginosa and (16%) staphylococcus aureus, while Aspergillus (40%) was the most common fungal isolate, followed by Penicillium and fusarium species. Our results showed that P.aeruginosa was the responsible microorganism for rapid keratitis progression in three cases who were using cosmetic lenses promptly. Concerning antibiotic sensitivity, all gram-negative bacteria and positive isolates were susceptible to old-generation fluoroquinolones such as ciprofloxacin and levofloxacin, while ceftazidime showed resistance to penicillins.

Conclusion: In conclusion, with early suspicion and microbiological diagnostic procedures, appropriate therapy can only reduce the incidence of this threatening ocular case.