AEROBACTIN AND OTHER VIRULENCE FACTOR GENES AMONG STRAINS OF ESCHERICHIA-COLI CAUSING UROSEPSIS - ASSOCIATION WITH PATIENT CHARACTERISTICS
AEROBACTIN AND OTHER VIRULENCE FACTOR GENES AMONG STRAINS OF ESCHERICHIA-COLI CAUSING UROSEPSIS - ASSOCIATION WITH PATIENT CHARACTERISTICS
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DOI：
10.1128/iai.56.2.405-412.1988
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发表时间：
1988-02-01
影响因子：
3.1
通讯作者：
STAMM, WE
中科院分区：
文献类型：
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作者：
JOHNSON, JR;MOSELEY, SL;STAMM, WE
为了评估需氧菌素作为尿路致病性大肠杆菌毒力因子的作用，我们确定了 58 种引起菌血症性尿路感染的大肠杆菌菌株中需氧菌素决定簇的流行率、位置和表型表达。我们将需氧菌素系统的存在与抗菌药物耐药性、其他泌尿道致病毒力因子决定因素（P菌毛、溶血素和1型菌毛）的存在和表型表达以及患者特征相关联。总DNA和质粒DNA与每种毒力因子的DNA探针的菌落和Southern杂交表明，需氧菌素决定簇存在于78%的菌株中，21%的菌株与质粒相关，而P菌毛、溶血素和1型菌毛决定簇分别存在于74%、43%和98%的菌株中，并且总是染色体上的。染色体需氧菌素、P菌毛和溶血素决定簇在染色体上同时出现在来自没有泌尿科或医学疾病倾向的患者的菌株中更常见（P = 0.04）。带有质粒编码的需氧菌素的菌株缺乏 P 菌毛 (P = 0.004) 和溶血素 (P = 0.0004) 决定簇，对多种抗菌药物具有耐药性 (P = 0.0001)，并且仅在受损患者中发现。交配实验表明，一些需氧杆菌素质粒也编码抗菌剂耐药性。这些发现表明，需氧菌素、菌毛和溶血素的决定因子在侵入非受损患者的抗菌剂敏感的尿路致病性大肠杆菌菌株的染色体上是保守的。相比之下，在受损宿主中引起尿脓毒症的大肠杆菌菌株中通常不存在这些染色体毒力因子。这些菌株可能获得与抗菌剂抗性基因结合的质粒需氧菌素。
To assess the role of aerobactin as a virulence factor among uropathogenic Escherichia coli, we determined the prevalence, location, and phenotypic expression of aerobactin determinants among 58 E. coli strains causing bacteremic urinary tract infections. We correlated the presence of the aerobactin system with antimicrobial-agent resistance, the presence and phenotypic expression of other uropathogenic virulence factor determinants (P fimbriae, hemolysin, and type 1 fimbriae), and characteristics of patients. Colony and Southern hybridization of total and plasmid DNA with DNA probes for each virulence factor showed that aerobactin determinants were present in 78% of the strains and were plasmid associated in 21%, whereas P fimbria, hemolysin, and type 1 fimbria determinants were present in 74, 43, and 98% of the strains, respectively, and were always chromosomal. Chromosomal aerobactin, P fimbria, and hemolysin determinants occurred together on the chromosome more often in strains from patients without predisposing urological or medical conditions (P = 0.04). Strains with plasmid-encoded aerobactin lacked determinants for P fimbriae (P = 0.004) and hemolysin (P = 0.0004), were resistant to multiple antimicrobial agents (P = 0.0001), and were found only in compromised patients. Mating experiments demonstrated that some aerobactin plasmids also encoded antimicrobial-agent resistance. These findings suggest that the determinants for aerobactin, P fimbriae, and hemolysin are conserved on the chromosome of the antimicrobial-agent-susceptible uropathogenic strains of E. coli which invade noncompromised patients. In contrast, these chromosomal virulence factors are often absent from E. coli strains causing urosepsis in compromised hosts; these strains may acquire plasmid aerobactin in conjunction with antimicrobial-agent resistance genes.