Salmonella Heidelberg isoladas na cadeia produtiva de frangos de corte:biofilmes e controle, virulência, resistência antimicrobiana e implicações em saúde pública.

Abstract

Salmonella Heidelberg is considered an emerging serovar because of its increased isolation in food, especially in chicken meat and its derivatives, as well as its involvement in outbreaks of infections in humans. The thesis is divided into three chapters, the first consisting of the general considerations of the theme, addressing key issues that helps in contextualizing what will be discussed in the next chapters. The second chapter aimed to analyze 20 strains of S. Heidelberg, from poultry samples originated from the southern region of the country regarding the genes related to virulence (ompC, invA, sodC, avrA, lpfA, agfA and luxS) and antimicrobial resistance (qnrS and qnrA - fluoroquinolones; blaTEM and blaSHV - β-lactams), as well as to determine the antimicrobial resistance profiles of drugs / classes of importance in veterinary and human medicine (amoxicillin with clavulanate: β-lactams class, subclass of penicillins; colistin: class of polymyxins; ciprofloxacin: fluoroquinolone class; ceftriaxone: β-lactam class, subclass of 3rd generation cephalosporins). For the research of virulence and resistance genes in the second chapter, the PCR technique was used and the antimicrobial sensitivity was determined by the minimum inhibitory concentration (MIC). The third chapter aimed to analyze two strains of S. Heidelberg, isolated from broiler samples produced in southern Brazil, regarding the adhesion, formation and inhibition of biofilms with and without the addition of chicken juice at three different temperatures, 4, 25 and 37 ° C. It also evaluated the microscopic structure of the biofilm and the total genomic sequencing of the strains. In the third chapter, biofilm formation analyzes were performed in traditional microbiology using Tryptic Soy Broth (TSB) and in parallel in TSB supplemented with chicken juice (TSB + CJ) in quantitative and qualitative ways. Biofilm morphology was evaluated by scanning electron microscopy (SEM). Inhibition tests were performed with sanitizers used in industry (hypochlorite, chlorhexidine and peracetic acid) and genomic sequencing was performed on the Illumina HiSeq system and fastQC software was used to assemble the sequencing readings.