Contribution of the colicin receptor CirA to biofilm formation, antibotic resistance, and pathogenicity of Salmonella Enteritidis

Abstract

Salmonella Enteritidis is an important foodborne pathogen that can infect a wide range of animal species including human beings, resulting in great losses to commercial husbandry and human health. CirA is an outer membrane receptor involved in iron uptake and colicin1A/B‐mediated competitive killing. Although iron uptake is crucial to bacterial virulence, limited literature is available about the role of CirA in infection. In the present work, we aimed to evaluate the role of CirA during S. Enteritidis infection. For this purpose, we generated a CirA‐deficient mutant of the S. Enteritidis strain C50336 and examined its biological characteristics. The results showed that cirA gene inactivation caused sharply decreased biofilm formation and apparently impaired antibiotic resistance. Furthermore, the cirA gene deletion mutant showed markedly reduced adhesion and invasion to human epithelial cell line Caco‐2 cells and decreased proliferation in mouse macrophage cell line RAW264.7 cells. Moreover, attenuated virulence was determined by a mouse model, with an LD50 increase of approximately 1,000‐fold. These data indicated that CirA plays critical roles in the S. Enteritidis infection process.

Increased Drug Resistance and Biofilm Formation Ability in ST34-Type Salmonella Typhimurium Exhibiting Multicellular Behavior in China

“…The identification of multicellular behavioral phenotypes was carried out based on methods in previous reports, with slight modifications (Zhang et al, 2019). Briefly, 10 μl of the strains cultured overnight was dropped on a salt-free LB agar plate containing 40 mg/ml Congo Red and 20 mg/ml Coomassie Brilliant Blue G, and cultured at 27°C for 5 d. Subsequently, colony morphology on the plate was observed to determine whether the strain exhibited multicellular behavior, which was characterized based on the RDAR (red, dry, and rough) phenotype.…”

Analysis of antibiotic-induced drug resistance of Salmonella enteritidis and its biofilm formation mechanism

“…However, due to the extensive use of antibiotics in clinical, animal husbandry and veterinary, and animal-derived food processing, the drug resistance of Salmonella is increasing, and the phenomenon of multi-drug resistance (MDR) is also becoming more and more serious. Salmonella has an important impact on human society, so the monitoring of its drug resistance data is of great significance for analyzing the evolution of its drug resistance spectrum, guiding clinical medication, and preventing the infection and prevalence of Salmonella [ 3 ]. Salmonella typhimurium and Salmonella enteritidis are the most common Salmonella enteritidis that can infect humans.…”

In vivo and in silico Virulence Analysis of Leptospira Species Isolated From Environments and Rodents in Leptospirosis Outbreak Areas in Malaysia

“…Another potential virulence factor is cirA, a gene that encodes the colicin I receptor. CirA mutant Salmonella enteritidis strain C50336 showed a sharp decrease in biofilm formation and impaired antibiotic resistance (Zhang et al, 2020). The genome of L. interrogans strain HP358 also contains sspH1 gene that encodes the E3 ubiquitin-protein ligase SspH1.…”