Isolation,identification,and antimicrobial susceptibility test of Escherichia fergusonii from alpacas
Liu Huadong
Lu Zihan
Wang Rui
Han Xinrun
Li Jun
Li Tingting
Wang Guoyan
Tang Juan
Abstract：A case of abortions,weak births,and neonatal mortality in alpacas occurred on a farm in Shanxi Province.This study aimed to identify the causative pathogen and provide diagnostic and disease control strategies for the farm.Heart,liver,spleen,and kidney samples from deceased alpacas were aseptically collected and inoculated onto multiple culture media,for bacterial isolation.Colony growth was observed,and single colonies were subjected to Gram staining for morphological analysis.The isolates were further identified by PCR and antimicrobial susceptibility testing.Results showed bacterial growth on all media.Colonies appeared pink on MacConkey and SS agar,while small colonies with metallic sheen were observed on eosin methylene blue(EMB)agar.Microscopic examination revealed abundant uniform Gram-negative bacilli.These morphological characteristics aligned with Escherichia fergusonii.PCR amplification,sequencing,and BLAST analysis confirmed the isolates as Escherichia fergusonii.Antimicrobial susceptibility testing indicated that the isolates were susceptible to fluoroquinolones,aminoglycosides,cephalosporins,azithromycin,and florfenicol.The study identified Escherichia fergusonii as the causative pathogen responsible for the alpaca infections on this farm,demonstrating susceptibility to fluoroquinolones,aminoglycosides,cephalosporins,azithromycin,and florfenicol.
Keywords：AlpacaEscherichia fergusoniiAbortionDiarrheaPCR identification
Publication Date：2025-08-15
Online Publishing Date：2025-09-22(First online date of this platform, not the publication date of the document)
Pages：5( 60-64 )