抗菌肽对抗生素耐药菌株的抑菌活性研究

[目的]研究抗菌肽对抗生素耐药菌株的抑菌活性。[方法]利用抗性平板划线法从腹泻病牛血便中筛选分离出1株耐药菌,通过16S rDNA序列进行鉴定,采用琼脂孔穴扩散法通过梯度盐酸壮观霉素（spectinomycin,Spe⁺）、氨苄青霉素（ampicillin,Amp⁺）、硫酸卡那霉素（kanamycin,Kan⁺）和氯霉素（chloramphenicol,Cm⁺）试验确定该菌药敏特性,并利用1种抗菌肽制剂对该菌株进行药敏试验。[结果]经BLAST比对分析该菌16S rDNA序列,鉴定该耐药菌为科氏葡萄球菌（Staphylococcus cohnii）,此菌对Amp⁺敏感,但对试验中其他抗生素均有耐药性,各梯度抗菌肽对该耐药菌均具有明显的抑菌活性。[结论]抗菌肽能有效抑制耐药科氏葡萄球菌的生长,有望在畜牧生产中代替抗生素使用。

Evaluation of Antibacterial Activity of an Antibacterial Peptide Against a Clinically Isolated Antibiotic Resistant Bacterial Strain

[Objective]To assess the antibacterial activity of an antibacterial peptide against a clinically isolated antibiotic resistant bacterial strain.[Method]A bacterial strain with antimicrobial resistance was isolated from the bloody stool sample of cattle with diarrhea by the resistant plate streaking method,and was subsequently identified by 16S rDNA PCR and sequencing.The antibiotic susceptibility test of the isolate was carried out via agar hole diffusion method with the antimicrobial agents of spectinomycin,ampicillin,kanamycin and chloramphenicol.The antibacterial activity of an antibacterial peptide against the isolate was evaluated.[Result]The obtained isolate was molecularly identified as Staphylococcus cohnii.It was sensitive to ampicillin but resistant to the other tested antimicrobial agents.The antibacterial peptide of different concentrations expressed obvious antibacterial activity against the isolate.[Conclusion]The antibacterial peptide can effectively inhibit the growth of antibiotic resistant Staphylococcus cohnii and has potential to serve as an alternative to antibiotics in livestock production.