Comparison of Staphylococcus aureus strains isolated from milk and humans on dairy farms
Conference Year
January 2019
Abstract
Staphylococcus aureus is a commensal and pathogen of several mammalian species, particularly humans and cattle. It is a common cause of food poisoning, community-acquired skin infections, and a major cause of hospital-acquired infections like bacteremia and pneumonia. S. aureus is also the most common etiological agent of contagious bovine mastitis, causing significant losses in the dairy industry. Although antimicrobial therapy is an important strategy for mastitis control as well as human infections, S. aureus exhibits resistance to multiple classes of antimicrobial agents narrowing the therapeutic options for clinicians and veterinarians. Additionally, the proximity of humans and animals in the dairy environment has caused transmission of such drug-resistant bacteria like Methicillin Resistant S. aureus (MRSA) between animal and human hosts. So, it is necessary to monitor bacterial populations at the animal-human interface. Henceforth, we proposed a study to isolate S. aureus from cattle milk and humans to compare the genetic diversity of those isolates along with their antimicrobial resistance patterns. To this end, we have collected milk samples and human hand and nose swab samples from 16 farmstead cheese producers in Vermont. We, then, isolated presumptive S aureus using cultural and biochemical tests. Moving further, we will confirm presumptive S. aureus isolates by PCR amplification of the thermonuclease gene and strain-typing by multilocus sequence typing (MLST). After strain typing, we plan to perform antimicrobial sensitivity testing on all S. aureus strains by disc diffusion assay. PCR screening of those isolates will be done for antibiotic resistance determinants. Therefore, this study aims to investigate the presence of genetic similarities and antimicrobial resistant pattern of S. aureus strains among human and cattle hosts. This will be useful to determine the prevalence of human and livestock-associated MRSA strains of S. aureus in the farmstead cheese farms as well as their potential to colonize and infect both hosts.
Primary Faculty Mentor Name
John W. Barlow
Status
Graduate
Student College
College of Agriculture and Life Sciences
Program/Major
Animal, Nutrition and Food Sciences
Primary Research Category
Biological Sciences
Comparison of Staphylococcus aureus strains isolated from milk and humans on dairy farms
Staphylococcus aureus is a commensal and pathogen of several mammalian species, particularly humans and cattle. It is a common cause of food poisoning, community-acquired skin infections, and a major cause of hospital-acquired infections like bacteremia and pneumonia. S. aureus is also the most common etiological agent of contagious bovine mastitis, causing significant losses in the dairy industry. Although antimicrobial therapy is an important strategy for mastitis control as well as human infections, S. aureus exhibits resistance to multiple classes of antimicrobial agents narrowing the therapeutic options for clinicians and veterinarians. Additionally, the proximity of humans and animals in the dairy environment has caused transmission of such drug-resistant bacteria like Methicillin Resistant S. aureus (MRSA) between animal and human hosts. So, it is necessary to monitor bacterial populations at the animal-human interface. Henceforth, we proposed a study to isolate S. aureus from cattle milk and humans to compare the genetic diversity of those isolates along with their antimicrobial resistance patterns. To this end, we have collected milk samples and human hand and nose swab samples from 16 farmstead cheese producers in Vermont. We, then, isolated presumptive S aureus using cultural and biochemical tests. Moving further, we will confirm presumptive S. aureus isolates by PCR amplification of the thermonuclease gene and strain-typing by multilocus sequence typing (MLST). After strain typing, we plan to perform antimicrobial sensitivity testing on all S. aureus strains by disc diffusion assay. PCR screening of those isolates will be done for antibiotic resistance determinants. Therefore, this study aims to investigate the presence of genetic similarities and antimicrobial resistant pattern of S. aureus strains among human and cattle hosts. This will be useful to determine the prevalence of human and livestock-associated MRSA strains of S. aureus in the farmstead cheese farms as well as their potential to colonize and infect both hosts.