Potential pathogenic bacteria, antibiotic resistance genes, and virulence factors from the feces of Chroicocephalus ridibundus overwintering in Kunming

Abstract:

[Background] A large number of black-headed gulls (Chroicocephalus ridibundus) overwinter in Kunming and have close contact with people. Whether their fecal bacteria can be a source of infections or not arouses public concern. [Objective] To explore the potential pathogenic bacteria, antibiotic resistance genes (ARGs), and virulence factors (VFs) in the feces of C. ridibundus. [Methods] Firstly, the bacteria in the feces were isolated and identified, and the antibiotic resistance of some potential pathogens was examined. Secondly, metagenomic sequencing was employed to detect the potential pathogens, ARGs, and VFs in the feces. [Results] Enterococcus faecalis, Aeromonas veronii, and Shigella flexneri were the main potential pathogenic bacteria detected by the isolation method, and Escherichia coli, Escherichia albertii, and Enterococcus faecium were the main potential pathogenic bacteria detected by metagenomic sequencing. These bacteria were frequently detected in the intestines of other animals and humans. Some isolated potential pathogenic bacteria were resistant to few antibiotics. The ARGs and VFs detected through metagenomic sequencing were abundant and had rich sources in addition to potential pathogenic bacteria. However, the ARGs receiving clinical concerns were not detected with high identity and coverage. In addition, some potential pathogenic bacterial genera and ARGs had high associations between the feces and the water in the Dianchi Lake. [Conclusion] No pathogenic bacteria belonging to the risk group II (China) or the ARGs arousing clinical concern were detected in the feces of C. ridibundus. Therefore, we conclude that the bacteria from the feces of C. ridibundus do not pose an infection threat to healthy people.