Analysis of genomic profile and resistance to antimicrobials in Salmonella Heidelberg strains

Author(s)

Andrei Itajahy Secundo de Souza

• Document type: Master's Dissertation
• Press: Jaboticabal. 2020-05-21.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2019-09-02
• Advisor: Angelo Berchieri Junior; Mauro de Mesquita Souza Saraiva

Abstract

Salmonella Heidelberg (SH) is one of the serovars of the Salmonella genus capable of infecting both humans and animals. Infectious outbreaks in humans are mainly related to the consumption of products of poultry origin and the treatment is carried out with the use of antimicrobials. However, these drugs are also used in poultry production as performance enhancers, which results in bacterial resistance in SH, already reported in the literature. Thus, the aim of this study was to characterize 62 SH isolates regarding the phenotype of resistance to 20 antimicrobials; identify the genotype of resistance to β-lactams by means of PCR; and to evaluate the similarity of the isolates using the ERIC-PCR, REP-PCR, BOX-PCR and PFGE methodologies. All strains of SH were confirmed by PCR and subjected to sensitivity tests to 20 antimicrobials. Resistance was observed in 16 of the 20 antimicrobials used, highlighting the high resistance to β-lactams (CEF, FOX, AMP, CTX, AMX, AMC and IMP) with the identification of 41 multidrug resistant strains. From the PCR, genes encoding ESBL and AmpC enzymes were identified with a predominance of the blaCMY-2 gene. The PFGE proved to be the methodology with the greatest diversity compared to the others used with the majority of strains being grouped according to the isolation source. From the results of this study, it is possible to observe the diversity of SH isolates in Brazil harboring AmpC genes and presenting different profiles of phenotypic multidrug resistance, making SH a concern for public health. (AU)

• FAPESP's process: 17/25200-3 - Analysis of genomic and antimicrobial resistance profiles of Salmonella Heidelberg strains
• Grantee: Andrei Itajahy Secundo de Souza
• Support Opportunities: Scholarships in Brazil - Master