Abstract
Bacterial agents are considered important pathogens causing external otitis in dogs. It is essential to carry out bacterial culture and antimicrobial susceptibility test in the case of otitis externa, particularly for chronic or recurring cases. Sterile swab samples were obtained from terminal part of vertical ear canals of 74 dogs with otitis externa for cytology, bacterial culture and antimicrobial susceptibility test. Cytologic smears were stained using Gram and Giemsa staining methods. Aerobic bacterial culture performed on blood agar and MacConkey agar. Among total number of 92 isolated bacteria, 68 were Staphylococcus intermedius. Other isolated bacteria included: Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Pasteurella canis, and six other species of coagulase-negative Staphylococcus. Antimicrobial susceptibility test were performed for all isolated bacteria using 14 antibiotics. Based on the results of this study, all isolated Staphylococcus spp. were sensitive to amikacin, enrofloxacin, and rifampin, and had low resistance to gentamicin, cephalothin and ceftriaxone. More than half of gram-positive isolates were resistant to penicillin and ampicillin. Generally, all isolated gram-negative bacteria, were sensitive to amikacin and enrofloxacin, and had low resistance to ceftriaxone and gentamicin. They were highly resistant to penicillin, eythromycin, and cephalothin. Regarding the results of this study, in cases of uncomplicated otitis externa, it is possible to select antimicrobial drugs merely based on cytology, but it is recommended to perform bacterial culture and antimicrobial susceptibility test. However, in complicated or refractory cases, antimicrobials should be selected based on bacterial culture and antimicrobial susceptibility test.
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References
Angus JC (2004) Otic cytology in health and disease. Vet Clin Small Anim 34:411–424. doi:10.1016/j.cvsm.2003.10.005
Blue JL, Wooley RE (1977) Antimicrobial sensitivity patterns of bacteria isolated from dogs with otitis externa. J of Am Vet Med Assoc 171:362–363
Cole LK (2004) Otoscopic evaluation of the ear canal. Vet Clin Small Anim 34:397–410. doi:10.1016/j.cvsm.200310.004
Cole LK, Kwochka KW, Kowalski JJ, Hillier A (1998) Microbial flora and antimicrobial susceptibility patterns of isolated pathogens from the horizontal ear canal and middle ear in dogs with otitis media. J of Am Vet Med Assoc 212:534–538
Greene CE (2006) Otitis Externa. In: Greene CE (ed) infectious Diseases of the Dog and Cat, 3rd edn. Saunders, Missouri, pp 815–823
Hariharan H, Coles M, Poole D, Lund L, Page R (2006) Update on antimicrobial susceptibility of bacterial isolates from canine and feline otitis externa. Can Vet J 47:253–255.
Harvey RG, Harari J, Delauche AJ (2001) Ear Diseases of the Dog and Cat. Manson Publishing, London
Kiss G, Radvanyi S, Szigeti G (1997) New combination for the therapy of canine otitis externa I Microbiology of otitis externa. J of Small Animal Prac 38: 51–56
Lilenbaum W, Aquino MHC, Costa MNA, Souza Netto BA, Souza ET (1987) Bacterial otitis in dogs. Medical Science 6: 47–52
Lilenbaum W, Veras M, Blum E, Souza GN (2000) Antimicrobial susceptibility of staphylococci isolated from otitis externa in dogs. Letters in Applied Microbiology 31:42–45.
Lyskova P, Vydrzalova M, Mazurova J (2007) Identification and antimicrobial susceptibility of bacteria and yeasts isolated from healthy dogs and dogs with otitis externa. J Vet Med A Physiol Pathol Clin Med 54(10): 559–563. doi:10.1111/j.1439-0442.2007.00996.x
Martin Barrasa JL, Lupiola Gomez P, Gonzalez Lama Z, Tejedor Junco MT (2000) Antibacterial susceptibility patterns of Pseudomonas strains isolated from chronic otitis externa. J Vet Med B Infec Dis Vet Public Health 47(3):191–196. doi:10.1046/j.1439-0450.2000.00336.x
Quinn PJ, Carter ME, Markey B (1994) Clinical Veterinary Microbiology. Mosby, Spain
Rosser EJ (2004) Causes of otitis externa. Vet Clin Small Anim 34:459–468. doi:10.1016/j.cvsm.2003.10.006
Sarchahi AA, Haghkhah M, Firouzi R, Yarinasab F (2007) Bacterial and fungal normal flora of the external ear canal of dogs. Online J of Vet Research 11(1): 29–38.
Scott DW, Miller WH, Griffin CE (2001) Muller & Kirk’s small animal dermatology. Saunders, Philadelphia
Silva N (2001) Identification and antimicrobial susceptibility patterns of Staphylococcus spp. Isolated from canine chronic otitis externa. Arquivo Brasileiro de medicina veterinaria e zootecnia 53(2):1–5. doi:10.1590/S0102-09352001000200001
Wildermuth BE, Griffin CE, Rosenkrantz WS, Boord MJ (2007) Susceptibility of Pseudomonas isolates from the ears and skin of dogs to Enrofloxacin, marbofloxacin, and ciprofloxacin. J Am Anim Hosp Assoc 43(6):337–341.
Zahraei Salehi T, Farashi Bonab S (2006) Antibiotic susceptibility pattern of Escherichia coli strains isolated from chickens with colisepticemia in Tabriz province, iran. Inter J of Poultry Science 5(7): 677–684.
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The authors wish to acknowledge the cooperation received from colleagues in Small Animal Hospital and Microbiology department of Faculty of Veterinary Medicine of University of Tehran.
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Zamankhan Malayeri, H., Jamshidi, S. & Zahraei Salehi, T. Identification and antimicrobial susceptibility patterns of bacteria causing otitis externa in dogs. Vet Res Commun 34, 435–444 (2010). https://doi.org/10.1007/s11259-010-9417-y
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DOI: https://doi.org/10.1007/s11259-010-9417-y