Avian pathogenic Escherichia coli (APEC) is an important bacterial pathogen of chickens and causes colibacillosis such as airsacculitis, perihepatitis, omphalitis, peritonitis, salpingitis and pericarditis. As the transfer of antibiotic resistance from animal to humans can be possible surveillance on antibiotic resistance of APEC is very important. A total 34 APEC isolates from diseased chickens during the period from 2007 to 2009 were obtained. The susceptibility of the isolates to 13 antibiotics was determined by disc diffusion assay. Resistance to erythromycin was found in 97.1% of APEC isolated, followed by resistance to tetracycline (85.3%), doxycycline (82.3%), ampicillin (73.5%), sulfisoxazole (67.6%), enrofloxacin (67.6%), ciprofloxacin (64.7%), norfloxacin (61.7%) trimethoprim/sulfamethoxazole (52.9%), gentamycin (26.5%), amoxicillin (8.8%), colistin (5.9%), and amikacin (2.9%). The blaTEM genes were detected in 25 (100%) of the 25 ampicillin-resistant APEC isolates. Among the 29 tetracycline-resistant APEC isolates, tetA and tetB genes were detected in 18 (62.1%) and 9 (31%) isolates, respectively. Twenty six (76.5%) isolates were multiresistant to at least 6 antibiotics and seven (20.1%) isolates were multiresistant to at least 10 antibiotics. This results indicated that multiple antibiotic-resistant APEC is widespread in chicken flocks in Korea.

In the present study, ten herbal extracts, Citirus unchiu Markovich, root and stem of Berberis koreana, Morus alba, Dendrobium moniliforme, Aster gramineus, A. scabar, Alisma canaliculatum, Fallopia japonica and Origamum (O.) vulgare were determined to examine anti-mycoplasmal activity. Among them, O. vulgare extract (OVE) showed strong anti-mycoplasmal activity and was analyzed by gas-chromatography/mass spectrometry (GC/MS). As the results, OVE was consisted of carvacrol (68.78%), o-cymene (9.80%), terpinene (7.61%) and thymol (4.03%) as main ingredients. To investigate inflammatory activity by intact pathogenic Mycoplasma hyoneumoniae (M. hyo) at 30 ㎍/mL, we examined induced transcription of proinflammatory cytokines such as cyclooxygenase-2, tumor necrosis factor-a, interleukin (IL)-1, IL-6 and inducible nitric oxide synthase in RAW 264.7 cells. With the above results, we further investigated whether OVE could reduce inflammation induced by M. hyo at minimal inhibitory concentration. The result showed that 32 ㎍/mL of OVE inhibited nitric oxide production by 60%. This study also evaluated the combination of OVE with antibacterials against M. hyo for application. Based on these results, it could be concluded that M. hyo induces inflammation in RAW 264.7 cells and OVE protects this inflammation, indicating that OVE may be useful for industrial animals.

Study of sensitivity of Paenibacillus alvei to different antibiotic preparations (penicillin, tetracycline, neomycine, kanamycin, ampicillin, polymyxin, laevomycetin, enrofloxacin, tylosin, and streptomycin) was realized in the conditions of the Republic of Belarus. As the material of the research there was used the culture of agent the European foul brood caused by Paenibacillus alvei. Determination of therapeutic effectiveness of antibacterial agents in vitro conditions made it possible to choose the appropriate preparation for its use at beeyards with European foul brood caused by Paenibacillus alvei. During the experimental work there were used 10 antibacterial disks with various antibiotics. The best result against Paenibacillus alvei was shown by Tilozin, the diameter zone of growth inhibition was about 47,2+/-3,43 mm.

Sensitivity of European Faulbrut causative agent to Gentavet preparation was studied in the conditions liquid nutritive media in vitro in the Republic of Belarus. Research results showed that the studied preparation rendered the poisonous influence on European Faulbrut causative agent in concentration of 0,3 mkg/ml with the maximum rate 1:131072. The antibiotic showed the bacteriostatic ability in concentration of 0,15 mkg/ml. The antibacterial preparation did not influence the European Faulbrut causative agent in concentration of 0,01 mkg/ml. The total bacteriostatic effect the drug showed in concentration of 0,22 mkg/ml and its dilution of 1:196608.

For the well-timed prevention and treatment of sick animals there was analyzed the therapeutic efficiency of a produced survivor serum against acute respiratory diseases of sheep and lambs, as well as Catosal in combination with Nitox 200 against the mixed flow of parainfluenza-3, adenovirus, respiratory syncytial, chiamydial and pasteurellosis infection. Comparative efficiency of all mentioned preparations was presented. Research results showed the correct and timely application of drug preparations as well as their qualitative selection made it possible to lower the death cases. Application of the presented survivor serum in combination with Nitox 200 and Catosal made it possible to lower the loss of cattle in 4-5 times and increase the viability rate of animals