甘宁地区蛋鸡源肺炎克雷伯菌的抗菌药物敏感性及耐药基因分析

Antibacterial susceptibility and resistance gene analysis of Klebsiella pneumoniae isolated from laying hens in Gansu and Ningxia

肺炎克雷伯菌是一种可以通过可移动遗传元件携带并传播耐药基因的机会致病菌。本研究对甘肃和宁夏地区蛋鸡源肺炎克雷伯菌进行分离和鉴定,用纸片扩散法和PCR法检测耐药表型和耐药基因型。结果显示,245份样品中分离出肺炎克雷伯菌54株(分离率22.04%),54株(100.00%)分离株均有生物膜形成能力。分离株对大观霉素、复方新诺明、四环素、恩诺沙星和氧氟沙星等抗菌药物耐药严重,92.59%的分离株呈多重耐药表型。qnrB(90.74%)、bla_(SHV)(85.19%)、floR(75.93%)、sul1(72.22%)、gyrA(70.37%)和tetA(64.81%)等耐药基因检出率较高,并与耐药表型具有相关性。另外,发现1株多重耐药肺炎克雷伯菌携带产ESBLs基因bla_(SHV)、bla_(TEM)、bla_(CTX-M)和脂肽类耐药基因mcr-1和mcr-8等11种耐药基因,推测是通过可移动遗传元件形成的多种耐药基因富集株。本研究表明甘宁地区蛋鸡中肺炎克雷伯菌检出率较高,多重耐药情况严重,且耐药基因丰富。

Klebsiella pneumoniae is an opportunistic pathogen that can carry and disseminate antibacterial resistance genes via mobile genetic elements.This study aimed to isolate and identify K.pneumoniae from laying hens in Gansu and Ningxia.Antimicrobial susceptibility testing and detection of resistance phenotypes and genotypes were performed using the disc diffusion test and PCR,respectively.From 245 samples,we isolated 54 strains of K.pneumoniae,resulting in an isolation rate of 22.04%.All 54 strains exhibited the ability to form biofilms.The isolated strains demonstrated significant resistance to antibacterials such as spectinomycin,trimethoprim-sulfamethoxazole,tetracycline,enrofloxacin and ofloxacin,with 92.59%displaying a multidrug-resistant phenotype.High detection rates of resistance genes,including qnr B(90.74%),bla_(SHV)(85.19%),flo R(75.93%),sul1(72.22%),gyr A(70.37%),and tet A(64.81%),were observed,correlating with the resistance phenotype.Furthermore,we discovered a strain of multidrug-resistant K.pneumoniae carrying extended-spectrumβ-lactamase(ESBL)genes bla_(SHV),bla_(TEM),bla_(CTX-M),and colistin resistance genes mcr-1 and mcr-8.Additionally,eight other resistance genes were identified,suggesting a compilation of diverse resistance genes mediated by mobile genetic elements.The findings of the current study underscore a concerning prevalence of K.pneumoniae in laying hens in both Gansu and Ningxia,signifying a critical situation regarding multidrug resistance and a comprehensive array of resistance genes.