Bovine mastitis is most significant disease seen in dairy farms worldwide, resulting in the largest profit loss of any other disease affecting dairy cows. The aim of this thesis was to determine the predominant species responsible for bovine mastitis in a subset of ten Kentucky dairy herds, and to assess the presence of antibiotic resistance in these pathogens. In this study, 308 milk samples were obtained from cow's selected based on their recent somatic cell count. Samples positive for growth were identified using the gram stain and various biochemical tests. After identification, resistance to 11 antimicrobial agents was assessed using the Kirby-Bauer test. Staphylococcus aureus was found to be the most common species causing bovine mastitis, which was identified in 13% of milk samples. Coagulase negative Staphylococci (11%) and streptococci species (10%) were also found to be major causes of mastitis in Kentucky. Only one isolate of Streptococcus agalactiae was identified, indicating that this species is not prevalent in this state. S. aureus isolates were highly susceptible to all antibiotics used in the laboratory, with the only minor resistance seen in penicillin (7%), ampicillin (5%), oxacillin (2%), and cephalothin (2%). Coagulase negative Staphylococci species showed their highest resistance to oxacillin (31%), pirlimycin (23%), tetracycline (17%), and ampicillin (14%). Streptococci species were the least susceptible group of all the major pathogens identified, with many of these species resistance to kanamycin (69%), tetracycline (59%), and oxacillin (50%). Overall, the major pathogens recovered in this study were largely susceptible to cephalosporins, indicating that this group of antibiotics may be effective in the treatment of Kentucky's common bovine mastitis infections.
","abstract_html":"<p>Bovine mastitis is most significant disease seen in dairy farms worldwide, resulting in the largest profit loss of any other disease affecting dairy cows. The aim of this thesis was to determine the predominant species responsible for bovine mastitis in a subset of ten Kentucky dairy herds, and to assess the presence of antibiotic resistance in these pathogens. In this study, 308 milk samples were obtained from cow's selected based on their recent somatic cell count. Samples positive for growth were identified using the gram stain and various biochemical tests. After identification, resistance to 11 antimicrobial agents was assessed using the Kirby-Bauer test. <em>Staphylococcus aureus</em> was found to be the most common species causing bovine mastitis, which was identified in 13% of milk samples. Coagulase negative Staphylococci (11%) and streptococci species (10%) were also found to be major causes of mastitis in Kentucky. Only one isolate of <em>Streptococcus agalactiae</em> was identified, indicating that this species is not prevalent in this state. <em>S. aureus</em> isolates were highly susceptible to all antibiotics used in the laboratory, with the only minor resistance seen in penicillin (7%), ampicillin (5%), oxacillin (2%), and cephalothin (2%). Coagulase negative Staphylococci species showed their highest resistance to oxacillin (31%), pirlimycin (23%), tetracycline (17%), and ampicillin (14%). Streptococci species were the least susceptible group of all the major pathogens identified, with many of these species resistance to kanamycin (69%), tetracycline (59%), and oxacillin (50%). Overall, the major pathogens recovered in this study were largely susceptible to cephalosporins, indicating that this group of antibiotics may be effective in the treatment of Kentucky's common bovine mastitis infections. </p>","abstract_has_math":false,"creators":["West, Erica Denise"],"institution":"Eastern Kentucky University","degree_name":"Master of Science (MS)","degree_level":"Master's","degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-01-01T08:00:00Z","date_published":"2013-01-01T08:00:00Z","updated_at":"2026-07-24T02:15:19Z","subjects":["antibiotic","antimicrobial","bovine","mastitis","Animal Sciences"],"languages":[],"rights":["Copyright 2013 Erica Denise West"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://encompass.eku.edu/etd/145","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["West, Erica Denise"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Encompass Digital Archive, Eastern Kentucky University"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Master's"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Eastern Kentucky University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["antibiotic","antimicrobial","bovine","mastitis","Animal Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2013 Erica Denise West"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://encompass.eku.edu/etd/145"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Bovine mastitis is most significant disease seen in dairy farms worldwide, resulting in the largest profit loss of any other disease affecting dairy cows. The aim of this thesis was to determine the predominant species responsible for bovine mastitis in a subset of ten Kentucky dairy herds, and to assess the presence of antibiotic resistance in these pathogens. In this study, 308 milk samples were obtained from cow's selected based on their recent somatic cell count. Samples positive for growth were identified using the gram stain and various biochemical tests. After identification, resistance to 11 antimicrobial agents was assessed using the Kirby-Bauer test. Staphylococcus aureus was found to be the most common species causing bovine mastitis, which was identified in 13% of milk samples. Coagulase negative Staphylococci (11%) and streptococci species (10%) were also found to be major causes of mastitis in Kentucky. Only one isolate of Streptococcus agalactiae was identified, indicating that this species is not prevalent in this state. S. aureus isolates were highly susceptible to all antibiotics used in the laboratory, with the only minor resistance seen in penicillin (7%), ampicillin (5%), oxacillin (2%), and cephalothin (2%). Coagulase negative Staphylococci species showed their highest resistance to oxacillin (31%), pirlimycin (23%), tetracycline (17%), and ampicillin (14%). Streptococci species were the least susceptible group of all the major pathogens identified, with many of these species resistance to kanamycin (69%), tetracycline (59%), and oxacillin (50%). Overall, the major pathogens recovered in this study were largely susceptible to cephalosporins, indicating that this group of antibiotics may be effective in the treatment of Kentucky's common bovine mastitis infections.
"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:source","label":"Dc Source","values":["Encompass Digital Archive: Online Theses and Dissertations"]},{"key":"dc:title","label":"Title","values":["Assessment of Antimicrobial Resistance in Pathogens Responsible for Causing Bovine Mastitis in Kentucky"]}]}],"canonical_facts":{"dc:creator":["West, Erica Denise"],"dc:description.abstract":["Bovine mastitis is most significant disease seen in dairy farms worldwide, resulting in the largest profit loss of any other disease affecting dairy cows. The aim of this thesis was to determine the predominant species responsible for bovine mastitis in a subset of ten Kentucky dairy herds, and to assess the presence of antibiotic resistance in these pathogens. In this study, 308 milk samples were obtained from cow's selected based on their recent somatic cell count. Samples positive for growth were identified using the gram stain and various biochemical tests. After identification, resistance to 11 antimicrobial agents was assessed using the Kirby-Bauer test. Staphylococcus aureus was found to be the most common species causing bovine mastitis, which was identified in 13% of milk samples. Coagulase negative Staphylococci (11%) and streptococci species (10%) were also found to be major causes of mastitis in Kentucky. Only one isolate of Streptococcus agalactiae was identified, indicating that this species is not prevalent in this state. S. aureus isolates were highly susceptible to all antibiotics used in the laboratory, with the only minor resistance seen in penicillin (7%), ampicillin (5%), oxacillin (2%), and cephalothin (2%). Coagulase negative Staphylococci species showed their highest resistance to oxacillin (31%), pirlimycin (23%), tetracycline (17%), and ampicillin (14%). Streptococci species were the least susceptible group of all the major pathogens identified, with many of these species resistance to kanamycin (69%), tetracycline (59%), and oxacillin (50%). Overall, the major pathogens recovered in this study were largely susceptible to cephalosporins, indicating that this group of antibiotics may be effective in the treatment of Kentucky's common bovine mastitis infections.
"],"dc:format":["application/pdf"],"dc:identifier":["https://encompass.eku.edu/etd/145"],"dc:publisher":["Encompass Digital Archive, Eastern Kentucky University"],"dc:rights":["Copyright 2013 Erica Denise West"],"dc:source":["Encompass Digital Archive: Online Theses and Dissertations"],"dc:subject":["antibiotic","antimicrobial","bovine","mastitis","Animal Sciences"],"dc:title":["Assessment of Antimicrobial Resistance in Pathogens Responsible for Causing Bovine Mastitis in Kentucky"],"dc:type":["Master Thesis"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_level":["Master's"],"thesis:degree_name":["Master of Science (MS)"],"thesis:institution_name":["Eastern Kentucky University"]},"updated_at":"2026-07-24T02:15:19Z"}