Keywords

Staphylococcus aureus; genomic epidemiology; MRSA; MSSA; zoonotic infection; geographic distribution

Abstract

Staphylococcus aureus (S. aureus) is a gram-positive bacterial pathogen that colonizes human nasal passages, mucous membranes, or the skin of carriers, with colonization commonly found in 20-30% of healthy people. S. aureus has the potential for two types of infection within human hosts: methicillin-susceptible (MSSA) and methicillin-resistant (MRSA). These infections can be further classified based on their route of infection, either known as community-associated (CA), healthcare-associated (HA), or healthcare-associated community-onset (HACO). Upon further investigation of infected populations, specific genetic subtypes of S. aureus, known as sequence types (ST), have been identified globally, with some exhibiting increased virulence among populations. Each ST may possess a distinct evolutionary background and unique epidemiology. ST97 has been recently recognized as an epidemiologically important lineage with global distribution after comparison with a plethora of other sequenced S. aureus genomes. Analysis of sequencing data has identified isolates in the United States, Japan, and Brazil. The genomic epidemiology of S. aureus ST97 highlights its significant role as a zoonotic pathogen associated with livestock-associated (LA) infections. This study investigates the evolutionary and epidemiological impacts of ST97 through an extant literature review followed by meta-analysis of extant publicly available sequencing data. ST97 was found to have high levels of carriage primarily through human hosts in Europe and North America. Further phylogenetic analyses of the genetic diversity of ST97 resolved the population structure into four monophyletic clades. Antibiotic resistance and virulence factors were also characterized to determine the proportion of MRSA and other antibiotic resistance determinants. Ultimately, understanding these dynamics is critical for developing targeted interventions to mitigate the impact of ST97 among vulnerable populations.

Thesis Completion Year

2025

Thesis Completion Semester

Fall

Thesis Chair

Azarian, Taj

College

College of Medicine

Department

Burnett School of Biomedical Sciences

Thesis Discipline

Biomedical Sciences

Language

English

Access Status

Open Access

Length of Campus Access

None

Campus Location

Orlando (Main) Campus

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