Comparative virulence studies and transcriptome analysis of Staphylococcus aureus strains isolated from animals

Abstract

Several studies have been conducted to check the prevalence of methicillin-resistant strains of Staphylococcus aureus (MRSA) in animals and animal-derived food products but limited data are available regarding their virulence and associated gene expression profile. In the present study, antibiotic resistance and virulence of MRSA and methicillin-sensitive S. aureus animal isolates were determined in vitro by agar dilution, biofilm formation, adhesion, invasion and intracellular survivability assays. In addition, the pathogenicity of these isolates was examined in a murine model of S. aureus sepsis. MRSA1679a, a strain isolated from chicken, was observed to be highly virulent, in cell culture and in mouse model, and exhibited extensive resistant profile. Comparative gene expression profile of MRSA1679a and the reference human MRSA strain (ATCC 29213) was performed using Illumina-based transcriptome and RT-qPCR analyses. Several virulence elements including 22 toxin genes were detected in MRSA animal-isolate. In addition, we observed enhanced expression of crucial virulence regulators, such as sarA and KdpDE in MRSA animal-isolate compared to the human isolate. Collectively, gene expression profile including several virulence and drug-resistance factors confirmed the unique and highly virulent determinants of the MRSA strain of poultry origin which warrants further attention due to significant threat to public health.

Differences in virulence between the two more prevalent Staphylococcus aureus clonal complexes in rabbitries (CC121 and CC96) using an experimental model of mammary gland infection

“…The profile of the bacterial virulence genes detected in strains ST121 and ST96 matched those previously described for clonal complexes CC121 and CC96 [29]. Although variation in molecular profiles has already been described depending on the genotype [14,29,48,49], the detected genetic differences could justify variations in virulence between strain ST121 and strain ST96 as the gene expression and regulation of virulence elements in S. aureus isolates are generally controlled by global gene regulators [50]. Therefore, it would be necessary to increase knowledge about the gene expression and regulation of these virulence elements in strains ST121 and ST96 to better understand their role in the pathogenesis of staphylococcal infections.…”

Phenotypic and genotypic characterization of methicillin-resistant Staphylococcus aureus from bovine mastitis

“…The structural virulence factors include protein A, capsular polysaccharide, peptidoglycan and adhesions, while as secretory includes coagulase, lipase, hyaluronidase, proteases and hemolysins [7,8]. …”

Antimicrobial Activity of Novel Functionally Substituted Monocyclic and Spirocyclic Cyclohexane Derivatives

“…Numerous microorganisms like methicillin-resistant Staphylococcus aureus, multidrug resistant Escherichia coli, drug resistant Mycobacterium tuberculosis,multidrug resistant Pseudomonas aeruginosa. pose greater challenge for clinicians for treatment of infectious diseases (Iqbal et al, 2016;Hussain et al, 2017;Li and Webster, 2018). Currently there is emergence of pan drug resistant bacteria showing resistance to almost all the available antibiotics in the market (Bielawski et al, 2017).…”