Oyofo B A, Rollins D M
Infectious Disease Department, Naval Medical Research Institute, Bethesda, Maryland 20889-5607.
Appl Environ Microbiol. 1993 Dec;59(12):4090-5. doi: 10.1128/aem.59.12.4090-4095.1993.
A previously developed polymerase chain reaction (PCR) amplification of a target region in the flaA Campylobacter flagellin gene was evaluated and adapted for use with environmental water samples. The ability to detect Campylobacter jejuni or Campylobacter coli in seeded water samples was tested with various filters after concentration and freeze-thaw lysis of the bacterial cells. A nonradioactive probe for the amplified flagellin gene fragment detected as little as 1 to 10 fg of genomic DNA and as few as 10 to 100 viable C. jejuni cells per 100 ml of water filtered onto Fluoropore (Millipore Corp.) filters. No amplification was obtained with cellulose acetate filters, most likely because of binding of the DNA to the filter. Concentration and lysis of target cells on Fluoropore and Durapore (Millipore Corp.) filters allowed PCR to be performed in the same reaction tube without removing the filters. This methodology was then adapted for use with environmental water samples. The water supply to a broiler chicken production farm was suspected as the source of C. jejuni known to be endemic in grow-out flocks at the farm, despite the inability to culture the organisms by standard methods. The filtration-PCR method detected Campylobacter DNA in more than half of the farm water samples examined. Amplified campylobacter DNA was not detected in small volumes of regional surface water samples collected on a single occasion in February. The filtration-PCR amplification method provided a basis for detection of C. jejuni and C. coli in environmental waters with a high degree of specificity and sensitivity.
对先前开发的用于扩增弯曲杆菌鞭毛蛋白基因(flaA)中靶区域的聚合酶链反应(PCR)进行了评估,并使其适用于环境水样。在对细菌细胞进行浓缩和冻融裂解后,使用各种滤膜对接种水样中检测空肠弯曲杆菌或结肠弯曲杆菌的能力进行了测试。针对扩增的鞭毛蛋白基因片段的非放射性探针能够检测低至1至10 fg的基因组DNA,以及每100 ml过滤到氟孔(密理博公司)滤膜上的水中低至10至100个活的空肠弯曲杆菌细胞。使用醋酸纤维素滤膜未获得扩增产物,很可能是因为DNA与滤膜结合。在氟孔滤膜和聚醚砜(密理博公司)滤膜上对靶细胞进行浓缩和裂解后,无需移除滤膜即可在同一反应管中进行PCR。然后将该方法应用于环境水样。尽管无法通过标准方法培养出相关微生物,但一个肉鸡养殖场的供水被怀疑是空肠弯曲杆菌的来源,该菌在该养殖场的育成鸡群中呈地方性流行。过滤 - PCR方法在检测的一半以上的养殖场水样中检测到了弯曲杆菌DNA。在2月份单次采集的少量区域地表水样本中未检测到扩增的弯曲杆菌DNA。过滤 - PCR扩增方法为在环境水体中高度特异性和灵敏地检测空肠弯曲杆菌和结肠弯曲杆菌提供了依据。