On Distribution Of Pseudomonas Aeruginosa And Selection Of Antibiotics And Disinfectantsin From Farm Of Moschus Berezovskii

This study acquisited 52 samples on soil, water, air, body surface of animals, manure and urine, etc were acquired from a farm of Moschus Berezovskii in Zhenping County of Shanxi Province,among which 16 samples(comes from manure,urine, soil,sleeping areas,wound and nasal mucus)were detected to contain pseudomonas aeruginosa After analyzing total bacterial count and number of pseudomonas aeruginosa, it was found that pseudomonas aeruginosa mostly existed in manure, wound soil and nasal mucus, where the average bacterial count ranged from 106～ 1010CFU/g(mL).Isolated strains were identified by routine bacteriology and 16SrRNA.14 isolated strains from manure, urine, soil, sleeping areas and nasal mucus were detected to be short rod-shaped Gram-negative brevibacteria generating water-soluble green pigments. Two isolated strains from wounds were moderately long rod-shaped Gram-negative bacteria which didn’t produce water-soluble green pigments.Main findings of biochemical tests for 16 strains were consistent with literature reports.To be exact, sequencing results of 16 strains’target 16SrRNA fragments were homogenous with standard strains at a level above 99%. Thus, all of those 16 strains were eventually confirmed to be pseudomonas aeruginosa, numbered from PAsp-4 to PAsp-19. The virulence experiment on mice (LD50) suggested that the strains from wounds,manure, nasal mucus and urine of animals were far more virulent than those isolated from the environment of a farm such as soil and sleeping areas. The LD50 of the former strains was approximately 106CFU,and that of the latter strains was within 108-109CFU.According to the results of the susceptibility test,isolated 16 strains of pseudomonasae ruginosa were susceptible to Ciprofloxacin,Ofloxacin, Amikacin,Azlocillin, Cefixime and Imipenem.They were moderately susceptible to Cefperazone-Sulbactam,Gentamicin,and streptomycin,Polymyxin B,but unsusceptible to carbenicillin, Cefazolin,Ampicillin,Erythromyc in,tetracycline,SMZ/TMP,Florfenicol,and Cefurxime. After comparing the MIC ofseven antibi otics, including Cefperazone-Sulbactam, Gentamicin, tetracycline and SMZ/TMP,the MIC of Ciprofloxacin was found to be the lowest(0.15625-0.625μg/mL),followed byGentamicin(2.5-10μg/mL),streptomycin(20-160μg/mL),Florfenicol(160-640μg/mL),tetracycline(64-512μg/mL),c arbenicillin (160-1280μg/mL) and SMZ/TMP,which was still ineffective forbacteriostasis eve n its solubility reached saturaation.Therefore,Ciprofloxacin was the foremost choice for treati ng the infection by pseudomonas aeruginosa. in the farm.Based on the criteria for evaluating the disinfection effect of disinfectant as provided by GB15981-1995,the disinfection effects of four disinfectants commonly used in the farm of Moschus Berezovskii were evaluated,including peroxyacetic acid,benzalkonium bromide, iodophor and sodium hypochlorite.5% peroxyacetic acid was found to be the most effectiv e for disinfection. After 10 minutes of application,it could kill 100% of bacteriain 1.5×104 CFU/mL fresh bacterial liquid.