Berge Anna Catharina B, Adaska John M, Sischo William M
Veterinary Medicine Teaching and Research Center, University of California-Davis, Tulare, California 93274, USA.
Appl Environ Microbiol. 2004 Jan;70(1):318-23. doi: 10.1128/AEM.70.1.318-323.2004.
Recently, multi-drug-resistant (MDR) Salmonella enterica subspecies enterica serovar Newport reemerged as a public and animal health problem. The antibiotic resistance of 198 isolates and the pulsed-field gel electrophoresis patterns (PFGE) of 139 isolates were determined. Serovar Newport isolates collected between 1988 and 2001 were included in the study. One hundred seventy-eight isolates were collected from the San Joaquin valley in California and came from dairy cattle clinical samples, human clinical samples, bulk tank milk samples, fecal samples from preweaned calves, and waterways. Twenty clinical isolates from humans from various regions of the United States were also included in the study. Resistance to 18 antibiotics was determined using a disk diffusion assay. PFGE patterns were determined using a single enzyme (XbaI). The PFGE and antibiogram patterns were described using cluster analysis. Although the antibiotic resistance patterns of historic (1988 to 1995) and contemporary (1999 to 2001) isolates were similar, the contemporary isolates differed from the historic isolates by being resistant to cephalosporins and florfenicol and in their general sensitivity to kanamycin and neomycin. With few exceptions, the contemporary isolates clustered together and were clearly separated from the historic isolates. One PFGE-antibiogram cluster combination was predominant for the recent isolates, which were taken from human samples from all parts of the United States, as well as in the isolates from California, indicating a rapid dissemination of this phenotypic strain. The data are consistent with the hypothesis that the reemergence of MDR serovar Newport is not simply an acquisition of further antibiotic resistance genes by the historic isolates but reflects a different genetic lineage.
最近，多重耐药性肠炎沙门氏菌肠炎亚种新港血清型再度成为一个公共卫生和动物健康问题。测定了198株菌株的抗生素耐药性以及139株菌株的脉冲场凝胶电泳图谱（PFGE）。研究纳入了1988年至2001年间收集的新港血清型菌株。178株菌株从加利福尼亚州的圣华金谷收集，来自奶牛临床样本、人类临床样本、储奶罐奶样、断奶前犊牛粪便样本和水道。来自美国不同地区的20株人类临床分离株也纳入了研究。使用纸片扩散法测定对18种抗生素的耐药性。使用单一酶（XbaI）确定PFGE图谱。使用聚类分析描述PFGE和抗菌谱模式。尽管历史时期（1988年至1995年）和当代（1999年至2001年）分离株的抗生素耐药模式相似，但当代分离株与历史分离株的不同之处在于对头孢菌素和氟苯尼考耐药，以及对卡那霉素和新霉素的总体敏感性。除少数例外，当代分离株聚集在一起，并与历史分离株明显分开。一种PFGE-抗菌谱聚类组合在近期分离株中占主导地位，这些分离株取自美国各地的人类样本以及加利福尼亚州的分离株，表明这种表型菌株正在迅速传播。数据与以下假设一致，即多重耐药新港血清型的再度出现并非仅仅是历史分离株进一步获得抗生素耐药基因，而是反映了不同遗传谱系。
