Comparison of microbial isolates isolated from external ear canal of sheep and their susceptibility to antibiotics

Abstract

One hundred sheep with bilateral otitis externa were studied one year and a half .The
exudates of both external ears obtained using sterile swabs, and microorganisms were isolated
according to standard microbiological techniques. There was bacterial and fungal growth in
many of the samples. The total numbers of isolates from right ear was 104 , and the most
common pathogens isolated in right ear were Staphylococcus aureus 30.76 % , then
Staphylococcus epidermidis 9.61% and Pseudomonas aeruginosa 9.61 % while E.coli ,
Proteus mirabilis and Streptococcus pyogenes were 7.69% for each of them , Candida
albicans 5.76% , Klebsiella pneumonia 3.84% ,Nocardia spp 3.84% , Pasteurella multucida
3.84% ,Mannheimia haemolytica 3.84% , Aspergillus spp. 3.84 % and Streptomyces spp.
1.23% . The total number of isolates from left ear was 96 ,the most pathogens were
Staphylococcus aureus 27.08% while Pseudomonas aeruginosa 12.5% and Streptococcus
pyogenes were 12.5% , Klebsiella pneumonia 8.33 % and Proteus mirabilis 8.33 % ,
Staphylococcus epidermidis , Nocardia spp 6.25 % , then Streptomyces spp , Pasteurella
multucida and Mannheimia haemolytica were 4.16% , the last E.coli , Aspergillus spp and
Candida albicans were 2.08 % for each of them . The result were showed significant
differences at level P ˂0.05 between bacteria and fungi isolates, and have no significant
differences at level P˃ 0.05 between right and left ear . High susceptible rates of gram
positive Staphylococcus aureus to (Amoxicillin + Clavulaunic acid) and Chloramphenicol
were 100 % , while high susceptible rates of gram negative Pseudomonas aeruginosa was
90.90 % to Ciprofloxacin, (Amoxicillin+ Clavulaunic acid) and Chloramphenicol .