Abstract

Septicemia is one of the infectious diseases which have zoonotic and economic importance all over the world. Therefore, this study isolated and identified some of the aerobic, septicemic bacteria and then antimicrobial susceptibility test was done in the period November 2006 to May 2007 on 830 sick cattle of different age groups, which were brought to Sebeta veterinary clinic from Sebeta and its surrounding of parts Ethiopia. From these cattle, only 70 cattle found with sign of septicemia. Accordingly, the study was carried out on these 70 Septicemic cattle with objectives of isolation and identification of septicemic, aerobic bacteria and establishing of antimicrobial susceptibility test. Hence, from the study animals, whole blood samples were collected aseptically from jugular vein for bacteria culture. As a result, out of 70 blood samples, 42 (60%) cultures were found with aerobic gram positive and negative bacteria, which consists 28 (66.67%) gram positive and 14 (33.33%) gram negative bacteria. The isolated bacterial species wereStaphylococcus aureus 5 (11.9%), other Staphylococcus species 14 (33.33%),Streptococcus species 2 (4.8%), Listeria monocytogenes 3 (7.1%), other Listeria species 2 (4.8%), B. anthracis 2 (4.8%), Escherichia coli 4 (9.5%), Pasteurella multocida 9 (21.4%) and Pseudomonas aeruginosa 1 (2.4%). On the other hand, the in vitroantimicrobial susceptibility test showed that all bacterial isolates were susceptible to Novobiocin and Chloraphenenicol except P. aeruginosa. Generally, the bacterial isolates revealed various degree of susceptibility against gentamicin, trimethoprim-sulphamethoxazole, methicillin, polymixin B, oxytetracycline, penicillin G and ampicillin.Conversely, from all isolates, Ps. aeruginosa showed highest resistance to all antimicrobials except to gentamicin. Also almost all bacterial isolates were resistant to bacitracin. Of course, further study is required to elucidate the true nature of septicemic agents and rational use of antimicrobial therapy.

Key words: Septicemia, infectious diseases, and antimicrobial susceptibility test.