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Cal Poly

Presence of Antibiotic Resistant Salmonella spp. in Backyard Poultry and Their Environment

Abstract

dc:description.abstract

<p>As keeping backyard poultry rises, human contact with zoonotic pathogens will increase. One such pathogen that backyard enthusiasts have exposure risks to is <em>Salmonella </em>spp<em>.</em> which may cause a potential public health threat due to its increasing multidrug resistancy.<em> Salmonella </em>spp. were present in 33 of 50 samples collected from 29 sites with backyard poultry coops in San Luis Obispo County during March to May in 2014. Two different Hardy-CHROME™ <em>Salmonella</em> Selective Media plates were used to culture and isolate positive samples of <em>Salmonella </em>spp.. Each positive isolate was tested for antimicrobial sensitivity to 6 standard antibiotics: Ampicillin, Bacitracin, Erythromycin, Gentamicin, Penicillin, and Tetracycline, at the standard disk concentration levels. The Kirby-Bauer antimicrobial sensitivity test determined that 12 different profiles emerged from the <em>Salmonella </em>spp. isolates. All antimicrobial sensitivity profiles showed multidrug resistance <em>in vitro</em> with only high susceptibility to 2 major antibiotics, Gentamicin at 97% and Ampicillin at 51%. All profiles were resistant to 1 or more of the antimicrobials tested, plus the control. One <em>Salmonella</em> isolated was resistant to all 6 antimicrobials and another isolate to 5. The <em>Salmonella </em>spp. isolates proved multidrug resistance between 73%-100% to the other 4 antibiotics tested.</p> <p>The 24 <em>Salmonella </em>spp. positive sites displayed a lack of proper biosecurity and poultry husbandry practices. The criteria developed for accessing the poultry’s environment ranged from dedicated shoes for cleaning, egg handling, access to other animals and wildlife, number of birds and breeds or species in a coop, cleaning routine, over-all biosecurity and human interactions. Human exposure to <em>Salmonella </em>spp<em>.</em> pathogenic strains could increase due to environmental cross contamination and deficiencies in sanitation. The presence of <em>Salmonella </em>spp. with a diversity of antibiotic resistance serotypes is an important source of zoonotic pathogens for animal and human diseases that has public health risk implications.</p>

Degree

thesis:*
Name thesis:degree_name
MS in Agriculture - Animal Science
Discipline thesis:degree_discipline
Animal Science
Year dc:date.available
2018

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Land, Nicole
Contributors dc:contributor
  • Jaymie Noland

Subjects

dc:subject × 7

Identifiers

dc:identifier.*
OAI identifier oai:identifier
oai:digitalcommons.calpoly.edu:theses-3349

Chain of custody

source
Harvested from
Cal Poly
Base URL
digitalcommons.calpoly.edu/do/oai/
Last updated
2026-07-24
Source record
OAI-PMH GetRecord
citation

Land, Nicole. Presence of Antibiotic Resistant Salmonella spp. in Backyard Poultry and Their Environment. 2018. https://digitalcommons.calpoly.edu/theses/2005