Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae and risk factors associated with high total bacterial count in bulk tank milk from dairy farms in Colombia

ABSTRACT: The objective of the study was to evaluate the frequency and genetic characteristics of ESBL-producing Escherichia coli and Klebsiella spp. and the risk factors associated with a high total bacterial count in bulk tank milk samples of dairy farms in three municipalities of the Antioquia Department, Colombia. Fifteen samples were positive for E. coli and Klebsiella spp. Subsequent analysis of the 16 S rRNA gene sequences confirmed these isolates included E. coli (n=3), K. oxytoca (n=11), and K. pneumoniae (n=1). None of the isolates was positive for ESBL identification by phenotypic methods, but the only the isolate of K. pneumoniae was positive for the blaSHV61 gene by sequence analysis. The antibiotic susceptibility evaluation for all Klebsiella spp. isolates identified resistance to fosfomycin (50%; 6/12) and ampicillin (100%; 12/12). While most of the herds maintain adequate hygienic quality, specific risk factors such as having more than 60 milking cows, frequent changes in milkers, milking in paddocks, and using a chlorinated product for pre-dipping have been identified as associated with a high total bacterial count>100,000 CFU/mL in bulk tank milk. However, certain variables including the milker being the owner of the animals and the proper washing and disinfection of the milking machine contribute to maintain a high level of hygiene and quality in the raw milk stored in the tanks. In conclusion, the frequency of ESBL producers was relatively low, with only K. pneumoniae testing positive for the blaSHV ESBL type. The presence of these bacteria in milk tanks represents a potential risk to public health for consumers of raw milk and its derivatives.

• Autores: Ágredo Campos, Ángela Sofía; Fernández Silva, Jorge Arturo; Ramírez Vásquez, Nicolás Fernando; Akineden, Ömer
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2024
• Institución: Universidad de Antioquia
• Repositorio: Repositorio UdeA
• Idioma: eng
• OAI Identifier: oai:bibliotecadigital.udea.edu.co:10495/42373
• Acceso en línea: https://hdl.handle.net/10495/42373
• Palabra clave: Antibacterianos; Anti-Bacterial Agents; Colombia; Infecciones por Klebsiella; Klebsiella Infections; Klebsiella pneumoniae; Pruebas de Sensibilidad Microbiana; Microbial Sensitivity Tests; Leche - microbiología; Milk - microbiology; beta-Lactamasas; beta-Lactamases; Tanques de leche; Milk tanks; Conteo bacteriano; Bacterial counting; Resistencia a los antimicrobianos; Antimicrobial resistance; Ganado bovino; Cattle; Ganadería lechera; Dairying; Escherichia coli; Explotaciones agrarias; Farms; http://aims.fao.org/aos/agrovoc/c_25810; http://aims.fao.org/aos/agrovoc/c_16691; http://aims.fao.org/aos/agrovoc/c_662faf6f; http://aims.fao.org/aos/agrovoc/c_1391; http://aims.fao.org/aos/agrovoc/c_10274; http://aims.fao.org/aos/agrovoc/c_33700; http://aims.fao.org/aos/agrovoc/c_2809; https://id.nlm.nih.gov/mesh/D000900; https://id.nlm.nih.gov/mesh/D003105; https://id.nlm.nih.gov/mesh/D007710; https://id.nlm.nih.gov/mesh/D007711; https://id.nlm.nih.gov/mesh/D008826; https://id.nlm.nih.gov/mesh/D008892; https://id.nlm.nih.gov/mesh/D001618
• Rights: openAccess
• License: http://creativecommons.org/licenses/by/2.5/co/