A Field Study on Antibiotic Resistant Escherichia Coli Isolated from Livestock, Wild Animals and Wastewater in a Stock Farm

摘要

Livestock administered an antibiotic treatment has a high potential to acquire antibiotic resistant bacteria. Then, the antibiotic resistant bacteria are exhausted with livestock excrement, and discharge to the outside a barn via drainage ditch. In addition, wild animals inhabiting the livestock farm such as mice and crows may be also affected by the antibiotic resistant bacteria. In this study, the existence and distribution of antibiotic resistant Escherichia coli were investigated in a livestock farm. Feces samples were collected from cattle, mice and crows in the Sumiyoshi Livestock Science Station, University of Miyazaki, Japan. Water samples were also collected form a drainage pit and a wastewater reservoir tank. Susceptibility of the E. coli isolates from the samples to 12 antibiotics was tested by a disk diffusion method. During the investigation period, antibiotic resistant E. coli were isolated 15% from cattle, 30% from mice, 22% from crows, 10% from the pit wastewater, and 27% from the tank wastewater. Based on the antibiotic resistance profiling, it assumed that the antibiotic resistant E. coli isolated from cattle feces was transported to the wastewater reservoir tank via the drainage pit.