Evaluation of the Pathogenic Potential of Escherichia coli Strains Isolated from Eye Infections

Author(s)

Nunes, Pedro Henrique Soares ; Valiatti, Tiago Barcelos ; Santos, Ana Carolina de Mello ; Nascimento, Jullia Assis da Silva ; Santos-Neto, Jose Francisco ; Rocchetti, Talita Trevizani ; Yu, Maria Cecilia Zorat ; Hofling-Lima, Ana Luisa ; Gomes, Tania Aparecida Tardelli

• Document type: Journal article
• Source: MICROORGANISMS; v. 10, n. 6, p. 16-pg., 2022-06-01.

Abstract

While primarily Gram-positive bacteria cause bacterial eye infections, several Gram-negative species also pose eye health risks. Currently, few studies have tried to understand the pathogenic mechanisms involved in E. coli eye infections. Therefore, this study aimed to establish the pathogenic potential of E. coli strains isolated from eye infections. Twenty-two strains isolated between 2005 and 2019 from patients with keratitis or conjunctivitis were included and submitted to traditional polymerase chain reactions (PCR) to define their virulence profile, phylogeny, clonal relationship, and sequence type (ST). Phenotypic assays were employed to determine hemolytic activity, antimicrobial susceptibility, and adhesion to human primary corneal epithelial cells (PCS-700-010). The phylogenetic results indicated that groups B2 and ST131 were the most frequent. Twenty-five virulence genes were found among our strains, with ecp, sitA, fimA, and fyuA being the most prevalent. Two strains presented a hemolytic phenotype, and resistance to ciprofloxacin and ertapenem was found in six strains and one strain, respectively. Regarding adherence, all but one strains adhered in vitro to corneal cells. Our results indicate significant genetic and virulence variation among ocular strains and point to an ocular pathogenic potential related to multiple virulence mechanisms. (AU)

• FAPESP's process: 17/14821-7 - Exploring novel virulence strategies in Escherichia coli
• Grantee: Tânia Aparecida Tardelli Gomes do Amaral
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/21947-7 - Analysis of the genome and virulence potential of a uropathogenic Escherichia coli (UPEC) strain carrying diarrheogenic E. coli (DEC) markers
• Grantee: Tiago Barcelos Valiatti
• Support Opportunities: Scholarships in Brazil - Master