Virulence factors and antimicrobial resistance genes of Enterococcus spp. isolated from Hospitalized Patients in the context of the COVID-19 pandemic

SCHELL, C; BLANCATO, VS; CARBONE, R; BORTURO, M; MAGNI, C

Buenos Aires

Simposio; XXI Simposio Internacional Mundo Sano; 2023

Mundo Sano

Introduction: The escalating resistance of bacteria to antimicrobials presents asignificant global public health threat in the upcoming years. The surveillance andinvestigation of antimicrobial resistance (AR) and virulence factor (VF) genes,particularly in multidrug-resistant (MDR) nosocomial pathogens, have not beenadequately prioritized within health institutions, especially in the context ofCOVID-19. This lack of attention is attributed to the pandemic, which has furthercomplicated the rational utilization of antimicrobials. The objective was to conductan epidemiological and molecular study in Enterococcus spp. strains isolatedfrom hospitalized patients using a "One Health" approach in the middle of theCOVID-19 pandemic.Materials and Methods: Enterococcus spp. strains were isolated from differentclinical sources of patients hospitalized at the H.I.G.A. Prof. Dr. Rodolfo Rossi (LaPlata) between September 2019 and August 2021. All strains were identified withconventional biochemical tests and confirmed by BD Phoenix™ M50. DNA wasextracted from all Enterococcus strains by heat lysis method (100°C, 15 min).The DNA (ng/µL) concentration was evaluated by absorbance in a microplatereader at 260 nm and the purity was quantified according to the 260/280 ratio.vanA, vanB, vanC, aac(6′)-Ie-aph(2″)-Ia, aph(2’’)-Ic, aph(2’’)-Id, gelE, cylA andesp genes were evaluated by PCR assay. This project was approved by therespective Bioethics Committee.Results: 17 enterococcal strains were selected from clinical samples, includingthose from the bone marrow transplant unit. 11 (64.7%) were identified as E.faecium and 6 (35.3%) as E. faecalis. The highest number of isolates wasobserved in the post-pandemic cohort (n=10 Enterococcus spp. in 2021).Notably, 35.3% of the strains were associated with healthcare-associatedinfections (HAIs). 10 (58.8%) were identified as vancomycin-resistant E. faecium(VREFM) and exhibited an MDR profile (resistance to ampicillin (100%),ampicillin/sulbactam (100%), high-level gentamicin resistance (70%), amikacin(90%), ciprofloxacin (90%), and linezolid (10%). The vanA genotype wasdetected in 10 VREFM strains (90.9%-p=0.000). aac(6′)-Ie-aph(2″)-Ia gen wasfound in E. faecium (n=7) and E. faecalis (n=1). Among the E. faecalis and E.faecium isolates, the esp gene was the most frequently detected (58.8%),followed by gelE (41.2%) and cylA (5.9%). Statistically significant association wasobserved with gelE (p=0.009) and esp (p=0.027) between species.Discussion and Conclusions: Understanding the characteristics of theresistome in each healthcare institution enables targeted interventions andstrategies. Nosocomial pathogens and commensal bacteria such as enterococcihave an essential role in spreading AR and VF using genome plasticity. Thisproject focused on implementing specific objectives outlined in the Preventionand Control of Antimicrobial Resistance (New Law No. 27680) in Argentina.Adjusting and complying with biosecurity protocols to contain the spread ofnosocomial pathogens is crucial in reducing HAIs.