Bacterial isolates and antimicrobial susceptibility pattern of ocular infection at a tertiary referral hospital in the South of Italy

Abstract

Purpose

The present study aimed to determine the prevalence of bacterial and fungal infections of the eye and also to assess the antibiotic susceptibility pattern of bacterial isolates at a tertiary referral eye care hospital in Bari, Italy.

Methods

Two hundred seventy three samples collected during a 2-year observation period. Culture, Gram's stain, potassium hydroxide mount and occasionally Giemsa staining was done for the clinical specimens. Antibiotic susceptibility testing was performed for bacterial growth.

Results

Out of 273 samples processed, 236 (86.4%) yielded growth: of them, 183 (77,5%) were bacterial, 26 (11%) fungal, and 23 (9,7%) specimens showed the presence of Acanthamoeba. Among bacterial infections, 99 (54.5%) bacterial isolates were Gram-positives, and 82 (44.8%) were Gram-negatives. Among Gram positives, Tigecycline showed the greatest susceptibility (93.8%), followed by Linezolid (97%) and Daptomycin (95.18%). Gram negative bacteria strains were susceptible to Imipenem (95%), Meropenem (98,5%) and Amikacin (91%) Multidrug in vitro resistance (resistance >3 classes of antibiotics) was found in 45 Gram positive (63%). and 33 Gram negative (44%).

Conclusion

Conjunctival specimens yielded mainly bacterial growth with Staphylococcus species being the predominant isolate followed by Pseudomonas species. Findings from the current analysis evidence a substantial level of in vitro resistance to ≥3 antibiotics.