Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, Aichi, Japan.
Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, Aichi, Japan.
J Infect Chemother. 2018 Jan;24(1):45-52. doi: 10.1016/j.jiac.2017.08.018. Epub 2017 Nov 6.
The increased prevalence of the virulence factor exoU + genotype among multidrug-resistant Pseudomonas aeruginosa has been previously reported. However, the genes that are related to the multidrug resistance of the exoU + genotype strain have not been analyzed and remain to be elucidated. The objective of this study was to analyze the correlations between virulence factors and resistance genes. The exoU + genotype was frequently found in carbapenem and fluoroquinolone non-susceptible strains. The imp carbapenemase genotype, the quinolone-resistance-determining region mutation in GyrA and ParC and the defective mutation in OprD were not frequently found in the exoU + genotype and carbapenem and fluoroquinolone non-susceptible strains. On the other hand, mexY and ampC mRNA overexpressing strains were more frequently found in the exoU + genotype and carbapenem and fluoroquinolone non-susceptible strains. Moreover, sequence type 235, a high risk clone of multidrug-resistant P. aeruginosa, was prevalent among the exoU + genotype and carbapenem and fluoroquinolone non-susceptible strains. ExoU is highly virulent protein, and the overexpression of efflux pumps and AmpC β-lactamase induce a multidrug-resistant phenotype. Therefore, the increased prevalence of P. aeruginosa strains with an exoU + genotype and the overexpression of efflux pumps and AmpC β-lactamase are likely to make P. aeruginosa infections difficult to treat. An understanding of the prevalence of both the exoU + genotype and the mRNA overexpression of resistance genes may help to select empirical therapy for the treatment of nosocomial infections caused by P. aeruginosa.
先前已有报道称，毒力因子 exoU + 基因型在多重耐药铜绿假单胞菌中的流行率有所增加。然而，与 exoU + 基因型菌株的多药耐药性相关的基因尚未被分析，仍有待阐明。本研究旨在分析毒力因子与耐药基因之间的相关性。exoU + 基因型在碳青霉烯类和氟喹诺酮类药物不敏感菌株中经常发现。在 exoU + 基因型和碳青霉烯类和氟喹诺酮类药物不敏感菌株中，未发现 imp 碳青霉烯酶基因型、GyrA 和 ParC 区喹诺酮耐药决定区突变和 OprD 缺陷突变。另一方面，mexY 和 ampC mRNA 过表达菌株在 exoU + 基因型和碳青霉烯类和氟喹诺酮类药物不敏感菌株中更为常见。此外，235 型序列是多重耐药铜绿假单胞菌的高危克隆，在 exoU + 基因型和碳青霉烯类和氟喹诺酮类药物不敏感菌株中较为流行。ExoU 是一种高毒力蛋白，外排泵和 AmpC β-内酰胺酶的过度表达会导致多药耐药表型。因此，exoU + 基因型铜绿假单胞菌菌株和外排泵及 AmpC β-内酰胺酶的过度表达的增加可能使铜绿假单胞菌感染更难治疗。了解 exoU + 基因型和耐药基因 mRNA 过表达的流行情况，可能有助于选择经验性治疗医院获得性铜绿假单胞菌感染。
