Salmonella enterica Serovar Minnesota Biofilms, Susceptibility to Biocides, and Molecular Characterization

Abstract

The presence of virulence genes, phylogenetic relationships, biofilm formation index (BFI), and ultrastructure in S. Minnesota at different temperatures (4, 25, and 36 °C) were analyzed. In addition, the ability of biocidal agents (chlorhexidine1%, sodium hypochlorite 1%, and peracetic acid 0.8%) to inhibit biofilms formed by 20 strains isolated from broiler slaughter plants from two Brazilian companies in 2009, 2010, and 2014 was determined. The presence of specific genes was evaluated by PCR and phylogeny between strains by pulsed-field gel electrophoresis. The BFI was determined using tryptone soy broth with 5% of chicken juice, and its structure was observed by scanning electron microscopy. The presence of specific genes indicated that S. Minnesota has the potential to cause disease in humans, adapting to adverse conditions. Temperatures of 25 and 36 °C favored biofilm formation, although at 4 °C, there was still biomass that could contaminate the final product. Tolerance to all biocides was identified in 12/20 (60%), representing a real risk of adaptation mechanisms development, especially regarding to resistance to sodium hypochlorite. Phylogenetic analysis indicated cross-contamination and spread among companies, which was probably related to biofilms formation. Results show the necessity of attention to this serovar considering its resistance to sodium hypochlorite, including the need for rigorous control, adopting low temperatures to prevent biofilms formation in the poultry industry.

Salmonella Heidelberg and Salmonella Minnesota in Brazilian broilers: Genomic characterization of third‐generation cephalosporin and fluoroquinolone‐resistant strains

“…The same point-mutations here detected in gyrA (p.S83F), parC (p.T57S), and qnrB19, have been reported in Brazilian poultry (de Melo et al, 2021;Monte et al, 2019) and all our isolates but one (which only harboured parC) showed complete or low-level resistance to ciprofloxacine and resistance to nalidixic acid according to the breakpoints (European Committee on Antimicrobial Susceptibility Testing…”

“…Genes involved in biofilm formation and acid tolerance were found in all of our isolates (Table 1 ). de Melo et al ( 2021 ) analysed the in vitro biofilm formation in SM from Brazilian poultry detecting genes for adhesion ( agfA/csg ), biofilm formation ( lpfA ), and survival under oxidative stress ( sodC ). These were also present in our isolates, except for sodC in SM, exemplifying the variety of circulating strains, even if sampled in the same geographical regions (Southeast Brazil).…”

Molecular Characterization and Survive Abilities of Salmonella Heidelberg Strains of Poultry Origin in Brazil

“…CJ contains a complex mixture of carbohydrates (0.06%) and protein (2.79%), giving an ideal medium for the proliferation and survival of bacteria and allows the formation of microlayers on the surfaces that aid in bacterial fixation. The influence of the increase promoted by the CJ was also identified in the Campylobacter jejuni, S. Typhimurium, S. Enteritidis, and S. Minnesota (Cappitelli et al, 2014;Li et al, 2017;Melo et al, 2017;de Melo et al, 2021). Despite the increase of extracellular matrix, CJ did not increase the number of viable cells, which is a strain-dependent characteristic.…”

“…The sessile structures of SH showed an effective increase in their intensity, according to the BFI, at higher temperatures (25 and 37 • C). According to de Melo et al (2021), the use of higher temperatures also favors the production of biofilms in S. Minnesota. The influence of temperature on the establishment of biofilms is described as a serovar-and strain-dependent characteristic.…”