Rosales-Reyes Roberto, Rodríguez-Alvarado Marian, Lezana-Fernández José Luis, Sánchez-Lozano Joselin Yleana, Gayosso-Vázquez Catalina, Jarillo-Quijada Ma Dolores, Toledano-Tableros José Eduardo, Arredondo-Mercado Martha Jimena, Alcántar-Curiel María Dolores, Lincopan Nilton, Vidal Jorge E, Lascurain Ricardo, Valvano Miguel A, Santos-Preciado José Ignacio
From the Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Laboratorio de Fisiología Pulmonar, Clinica de Fibrosis Quistica, Hospital Infantil de México Federico Gómez, Mexico City, Mexico.
Pediatr Infect Dis J. 2020 Oct;39(10):899-906. doi: 10.1097/INF.0000000000002714.
Long-term persistence of Pseudomonas aeruginosa in the lung of individuals with cystic fibrosis (CF) is associated with progressive selection of diverse genotypes and phenotypes. This bacterial adaptation leads to chronic infection and increased morbidity and mortality. The aim of this study was to establish the prevalence, clonal relatedness, antimicrobial susceptibility and virulence-associated phenotypes of P. aeruginosa isolates in a cohort of 50 Mexican children with CF-associated chronic lung infection.
Clonal relatedness of P. aeruginosa isolates was verified by pulsed-field gel electrophoresis. The antimicrobial susceptibility was determined by an automated system that performs bacterial identificación and antibiotic susceptibility testing (VITEK 2) and/or broth microdilution method. Biofilm formation was quantified with the crystal violet method; swarming motility was measured on soft agar, and susceptibility to normal human serum determined by reduction of colony formed units (CFUs).
High prevalence of P. aeruginosa colonization among Mexican children with CF was confirmed; 20% (10/49) of clones identified showed a multidrug-resistant phenotype and 8.2% (4/49) an extensive drug resistance phenotype; 26.5% (13/49) of the isolates were resistant to colistin, 42.9% (21/49) presented a phenotype of adaptation associated with chronic infection and 79.6% (39/49) showed increased ability to survive in normal human serum.
This cohort of children with CF reveals that colonizing P. aeruginosa strains predominantly display resistance to several first-line antibiotics, although most isolates were susceptible to meropenem and tobramycin; 42.9% of isolates showed a phenotype consistent with adaptation to chronic lung infection.
囊性纤维化（CF）患者肺部铜绿假单胞菌的长期持续存在与多种基因型和表型的逐步选择有关。这种细菌适应性导致慢性感染，并增加发病率和死亡率。本研究的目的是确定50名患有CF相关慢性肺部感染的墨西哥儿童队列中铜绿假单胞菌分离株的流行率、克隆相关性、抗菌药敏性和毒力相关表型。
通过脉冲场凝胶电泳验证铜绿假单胞菌分离株的克隆相关性。抗菌药敏性通过执行细菌鉴定和抗生素药敏试验的自动化系统（VITEK 2）和/或肉汤微量稀释法测定。用结晶紫法对生物膜形成进行定量；在软琼脂上测量群集运动性，并通过菌落形成单位（CFU）的减少来确定对正常人血清的敏感性。
证实墨西哥CF儿童中铜绿假单胞菌定植的患病率很高；鉴定出的克隆中有20%（10/49）表现出多重耐药表型，8.2%（4/49）表现出广泛耐药表型；26.5%（13/49）的分离株对黏菌素耐药，42.9%（21/49）表现出与慢性感染相关的适应表型，79.6%（39/49）在正常人血清中的存活能力增强。
这一CF儿童队列表明，尽管大多数分离株对美罗培南和妥布霉素敏感，但定植的铜绿假单胞菌菌株主要对几种一线抗生素耐药；42.9%的分离株表现出与慢性肺部感染适应一致的表型。
