title: 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.
authors.affiliation: MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China.
authors.forename: Zahid
authors.initials: Z
authors.lastname: Iqbal
authors.affiliation: Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA.
authors.forename: Mohamed N
authors.initials: MN
authors.lastname: Seleem
authors.affiliation: MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China.
authors.forename: Hafiz Iftikhar
authors.initials: HI
authors.lastname: Hussain
authors.affiliation: MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China.|Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Huazhong Agricultural University, Wuhan, China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Huang
authors.affiliation: MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China.
authors.forename: Haihong
authors.initials: H
authors.lastname: Hao
authors.affiliation: MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, China.|Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Huazhong Agricultural University, Wuhan, China.|National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, China.
authors.forename: Zonghui
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002645:Chickens; D005260:Female; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D051379:Mice; D008807:Mice, Inbred BALB C; D011201:Poultry Diseases / Q000382:microbiology*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C088021:SarA protein, bacterial; D015534:Trans-Activators; D011494:Protein Kinases; C075616:kdpD protein, Bacteria