Incidence and mechanism of ciprofloxacin resistance in Campylobacter spp. isolated from commercial poultry flocks in the United Kingdom before, during, and after fluoroquinolone treatment
Incidence and mechanism of ciprofloxacin resistance in Campylobacter spp. isolated from commercial poultry flocks in the United Kingdom before, during, and after fluoroquinolone treatment
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DOI：
10.1128/aac.49.2.699-707.2005
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发表时间：
2005-02-01
影响因子：
4.9
通讯作者：
Piddock, LJV
中科院分区：
文献类型：
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作者：
Griggs, DJ;Johnson, MM;Piddock, LJV
用氟喹诺酮治疗5只商品肉鸡群的临床相关感染。在屠宰前、期间和每周处理后，对个体鸡的新鲜粪便和环境样本进行弯曲杆菌培养。在所有处理阶段均分离出空肠弯曲杆菌和大肠杆菌。在治疗期间，喹诺酮耐药菌株的比例增加，并且这些菌株在治疗后持续存在。在所有处理阶段，对每个物种、每个血清型和每个噬菌体型的每个样品进行一个喹诺酮耐药分离物的表型和耐药机制检测。分离到两种抗性表型：Nal(r) Cip(r)和Nal(r) Cip(s)。大多数氟喹诺酮耐药菌株（290株中的269株），无论是空肠杆菌还是大肠杆菌，都有gyrA突变，导致取代Thr- bbb86 - >ile。检测到的其他gyrA突变为Thr- bbb86 ->Ala （n = 17）和Asp-90- >Asn （n = 10）。基于变性高效液相色谱和DNA测序鉴定的gyrA沉默突变的基因型变异用于补充分型数据，并为预先存在的耐药菌株的传播和处理鸡群中自发耐药突变体的选择提供证据。多药耐药与环丙沙星耐药显著相关（P < 0.01）。25%的环丙沙星耐药菌株（290株中的73株），但只有13%的敏感菌株（179株中的24株）对三种或三种以上不相关的抗菌素耐药。结论：经兽用氟喹诺酮治疗后，从商品鸡群中分离出大量喹诺酮耐药弯曲杆菌。大多数环丙沙星耐药菌株具有GyrA取代Thr- bbb86 ->Ile。从一些禽群的粪便中分离出耐药菌株，直至屠宰，这可能对公共卫生产生影响。
Five commercial broiler flocks were treated with a fluoroquinolone for a clinically relevant infection. Fresh feces from individual chickens and environmental samples were cultured for campylobacters before, during, and weekly posttreatment until slaughter. Both Campylobacter jejuni and C coli were isolated during all treatment phases. An increased proportion of quinolone-resistant strains was seen during treatment, and these strains persisted posttreatment. One quinolone-resistant isolate of each species, each serotype, and each phage type from each sample at all treatment phases was examined for its phenotype and mechanism of resistance. Two resistant phenotypes were isolated: Nal(r) Cip(r) and Nal(r) Cip(s). The majority (269 of 290) of fluoroquinolone-resistant isolates, whether they were C.jejuni or C. coli, had a mutation in gyrA that resulted in the substitution Thr-->86-->Ile. The other gyrA mutations detected were Thr-->86-->Ala (n = 17) and Asp-90-->Asn (n = 10). The genotypic variation, based on the silent mutations in gyrA identified by the denaturing high-performance liquid chromatography pattern and DNA sequencing, was used to supplement typing data and provided evidence for both the spread of preexisting resistant strains and the selection of spontaneous resistant mutants in treated flocks. Multidrug resistance was significantly (P < 0.01) associated with resistance to ciprofloxacin. Twenty-five percent (73 of 290) of ciprofloxacin-resistant isolates but only 13% (24 of 179) of susceptible isolates were resistant to three or more unrelated antimicrobial agents. In conclusion, quinolone-resistant campylobacters were isolated from commercial chicken flocks in high numbers following therapy with a veterinary fluoroquinolone. Most ciprofloxacin-resistant isolates had the GyrA substitution Thr-->86-->Ile. Resistant isolates were isolated from the feces of some flocks up to the point of slaughter, which may have consequences for public health.