Bacterial flora of the conjunctival sac of healthy Makni and Ghezel sheep in Urmia

Microbiological studies of diseased eyes are difficult to interpret unless they can be compared with similar studies performed on clinically normal eyes. The purpose of this study was to determine the normal eye bacterial flora of sheep in Urmia, Iran.The study was carried out in summer 2009 at slaughterhouse of Urmia. One hundred swabs were taken from the inferior conjunctival sac of 50 normal sheep (78 male, 11 female). All animals were of two makui (64%) and ghezel (36%) ecotypes, and divided into three age groups - yearlings (12%), 2-3 years (66%) and more than 4 years (22%). The samples were inoculated on blood and EMB agar, and examined for aerobic bacteria. One hundred fifty six isolates were identified in all 100 eyes. Single bacteria were isolated in 46 eyes. Two bacteria were isolated in 52 eyes; 3 bacteria were isolated in 2 eyes. There was no positive correlation between the number of isolates from each eye and age (p>0.05). The isolates included Bacillus cereus (47.74%), Enterobacter aerogenes (12.9%), Staphylococcus epidermidis (8.91%), Escherichia coli (8.91%), Dermatophilus congolensis (7%), Klebsiella spp. (5.8%), Streptococcus spp. (4.5%) and Staphylococcus aureus (4.5%). There was no significant difference in the number of bacterial isolates between sexes, age groups and ecotypes (p>0.05). Bacillus cereus was the most frequent isolate in both sexes, ecotypes and all age groups, and Enterobacter aerogenes was the second frequent isolate in both sexes, all age groups and makui ecotype, but in ghezel ecotype, Klebsiella spp. was the second frequent isolate. Regarding the frequency of each of isolates, there was no significant difference between the two sexes, three age groups and two ecotypes (p>0.05). Gram-positive aerobes were most commonly cultured from the conjunctival sac of normal sheep (72.43%), with Bacillus cereus predominating.