Surveillance of drug resistance and extended-spectrum beta-lactamase genes in Enterobacteriaceae from migratory birds in Nansha Wetland Park, Guangzhou

Abstract:

[Background] Resistance genes can be transferred among environment, animal, and human, and transferred for a long distance by migratory birds, thus posing a great threat to public health. [Objective] We isolated and identified the main Enterobacteriaceae bacteria from the feces of migratory birds in Nansha Wetland Park, Guangzhou, and explored the resistance to common antibiotics and the main resistance extended-spectrum beta-lactamase (ESBL) genes. On this basis, we assessed the risk of migratory birds in Guangzhou carrying and transferring resistance bacteria and genes. [Methods] From January to December 2019, 393 fecal samples were collected, and the bacteria were isolated, cultured, and identified. Through drug susceptibility test, the resistance of the bacteria was detected. PCR was performed to amplify the resistance genes bla_CTX-M, bla_TEM, and bla_SHV, followed by sequencing and BLAST alignment. [Results] A total of 59 Enterobacteriaceae strains (isolation rate 15.01%) were detected from the 393 fecal samples, among which Pantoea agglomerans (36 strains, 61.02%) was most abundant. Of the 59 strains, 89.83% were resistant to the tested antibiotics, and the resistance rates to cefazolin (81.36%), sulfisoxazole (52.54%), and ampicillin (44.07%) were particularly high. Moreover, 55.93% of the strains were resistant to multiple antibiotics. In addition, 7 strains were resistant to carbapenems. The sequencing result showed that 23 strains carried the resistance gene bla_TEM-1 (5.85%). [Conclusion] Enterobacteriaceae bacteria in the feces of migratory birds in Nansha Wetland Park, Guangzhou are intricacy, and the rates of drug resistance and multi-drug resistance are high. The result suggests the risk of the migratory birds carrying carbapenem-resistant Enterobacteriaceae bacteria, which has important public health significance.