Isolation and Identification of Aeromonas veronii in Sheep with Fatal Infection in China: A Case Report

Abstract

According to the findings of a sheep breeding farm in Shaanxi, China, 2.53% (15/594) of sheep exhibited respiratory (clinical) symptoms such as dyspnoea, nasal discharge, wet cough, fever, and progressive emaciation. Although multi-drug treatment strategies (including ampicillin, tylosin, florfenicol, and ceftiofur) have been attempted to improve clinical outcomes, they have only been met with limited success, with a mortality rate of 40%. Ultimately, Aeromonas veronii (A. veronii) was identified as the causative pathogen for respiratory disease. The rates of symptomatic and asymptomatic sheep positive to A. veronii were 64.28% (95% CI 52.25–76.31%) and 8.02% (95% CI 6.96–9.08%), respectively. Pathogenicity tests demonstrated that the A. veronii is pathogenic to sheep and mice. The results of the antibiotic susceptibility tests revealed that the strain was sensitive to cefotaxime, gentamicin, and enrofloxacin and resistant to ampicillin, ceftiofur, amoxicillin, kanamycin, neomycin, streptomycin, tetracycline, florfenicol, and tylosin. We suggest that the combination of cefotaxime and gentamicin is an effective treatment based on the results of an antimicrobial susceptibility test, which exhibited good therapeutic efficacy. To the best of our knowledge, this is the first report in which pathogenic A. veronii has been documented as the cause of death in sheep in China. We concluded that pathogenic A. veronii poses a potential risk to the industry of sheep husbandry. This study’s findings can help guide prevention and treatment plans for A. veronii infection in sheep.

Detection of Virulence Genes, Antimicrobial Susceptibility and Pathogenicity of Aeromonas veronii Isolates from Labeo rohita and Catla catla

“…Furthermore, the current investigation discovered that A. veronii is susceptible to antibiotics of aminoglycosides group; gentamycin (10 µg), fluroquinolones group; endrofloxacin (10 µg) and quinolones group; nalidixic acid (30 µg), there is a possibility that these antibiotics could control the A. veronii infections in fish farms. Hassan et al (2017) also found A. veronii to be sensitive to nalidixic acid, however Miao et al (2023) discovered resistance to gentamycin and enrofloxacin. Antimicrobial resistance has become a serious issue in aquaculture due to abuse of antibiotics not only as disease control agents but also as growth boosters.…”

Isolation, Identification, and Characterization of Aeromonas veronii from Chinese Soft-Shelled Turtle (Trionyx sinensis)

“…The LD 50 of A. veronii varies for different aquatic animals [ 28 ]. The LD 50 for longsnout catfish and largemouth bass was 3.47 × 10 4 CFU/g [ 29 ] and 3.72 × 10 4 CFU/g [ 30 ], respectively.…”

Characterization of Lung Microbiomes in Pneumonic Hu Sheep Using Culture Technique and 16S rRNA Gene Sequencing

“…The dominant colonies were picked for purification culture. Identification was performed as previously described [14]. The genomic DNA of isolates were extracted by a genomic DNA purification kit (DAKEWE, Shenzhen, China) according to manufacturer recommendations.…”

“…Hu sheep, a renowned sheep breed in China, stands out for its remarkable characteristics of early maturation and exceptional productivity [13]. There have been a growing number of reported cases of sheep pneumonia in China in recent years [9,14]. Moreover, numerous studies have endeavored to characterize the variability of lung microbiotas in healthy sheep [15,16].…”