Conjunctival cytological examination, bacteriological culture, and antimicrobial resistance profiles of healthy Mediterranean buffaloes (Bubalus bubalis) from Southern Italy

Objective: To assess normal conjunctival cytological and bacteriological/fungal flora features in the Mediterranean buffalo (Bubalus bubalis). Methods: Swabs were taken from the inferior conjunctival sac of both eyes of 57 healthy female buffaloes aged 24–36 months, with no evidence of ocular disease, farmed in Campania region (Southern Italy), for microbiological analysis. Conjunctival eye specimens of both eyes were subsequently obtained by a cyto-brush, for cytological analysis. The antimicrobial susceptibility of bacterial isolates was also determined using the diskdiffusion method on Mueller Hinton agar plates. Results: Cytological examination of conjunctival swab specimens (114 eyes) revealed epithelial cells (basal, intermediate, columnar and superficial) in all samples, whereas neutrophils, lymphocytes and plasma cells were present in 70%, 10% and 2% of samples, respectively. Microorganisms, for a total of 261 aerobic bacteria and 6 fungi, were isolated from 112/114 conjunctival samples [98.25%; 95% confidence interval (CI): 93.18– 99.70]. Only two conjunctival swabs did not yield bacteria and/or fungi (2/114, 1.75%; 95% CI: 0.30–6.82). Gram-positive aerobes were most commonly cultured (181/261, 69.35%; 95% CI: 63.31–74.81), with Enterococcus faecium and Staphylococcus lentus predominating. Escherichia coli was the most frequently isolated as Gram-negative bacteria (80/261, 30.65%; 95% CI: 25.19–36.69). The antimicrobial resistance patterns of the isolated bacteria showed amoxycillin/clavulanic acid and cephalothin as the least sensitive antibiotics for both Gram-positive and Gram-negative bacteria. Conclusions: These results provided first information on normal conjunctival ocular microflora and cytological features in Mediterranean buffalo.