Characterization of Escherichia coli Isolated from Day-old Chicken Fluff in Taiwanese Hatcheries
Journal
Avian diseases
Journal Volume
63
Journal Issue
1
Pages
9月16日
Date Issued
2018
Author(s)
Abstract
Avian colibacillosis resulting from avian pathogenic Escherichia coli (APEC) seriously disrupts poultry production. Hatcheries are the main source of chickens for commercial farms. To characterize the potential pathogenicity of E. coli strains isolated from hatcheries, 2344 fluff samples from 1-day-old chickens were collected from hatching incubators between October 2016 and November 2017. Among the hatcheries, the incidence of E. coli varied from 0% to 16.9%, with an overall incidence of 2.0%. High incidences reflected inadequate sanitation in some hatcheries. We also compared 20 clinically isolated APEC strains with fluff-originated E. coli in terms of existence of 10 virulence-associated genes (VAGs) and antimicrobial-resistance genes, and antimicrobial resistance using minimum inhibitory concentration (MIC) values. Our results showed that APEC more-frequently possessed most of the assessed VAGs (papC, astA, cvaC, hlyF, fyuA, iroN, iutA, iss, and ompT), suggesting that fluff-originated E. coli is less likely to cause avian colibacillosis. However, fluff-originated E. coli more-frequently expressed the adhesion gene fimC, which could confer higher upper respiratory tract adhesion. Both APEC and fluff-originated E. coli demonstrated multidrug resistance including 100% resistance to ampicillin, amoxicillin, cephalexin, florfenicol, and trimethoprim-sulfamethoxazole. Based on median MIC values, fluff-originated E. coli was more susceptible to antibiotics. However, resistance-gene existence did not significantly differ between groups, suggesting that fluff-originated E. coli should still be a public health concern. Molecular subtyping with XbaI-digested pulsed-field gel electrophoresis revealed that only a few strains showed identical patterns, indicating that a variety of contamination sources were present within individual hatcheries. Identical strains within the same hatchery may indicate vertical transmission from parent flocks. Overall, this is the first study to characterize fluff-originated E. coli. Our results suggest that it has lower pathogenicity than APEC and that thorough sanitation should be performed to reduce the occurrence of fluff-originated E. coli in hatcheries.Caracterizaci?n de Escherichia coli aislada de plum?n de pollitos de un d?a en plantas de incubaci?n en Taiw?n. La colibacilosis aviar resultante de Escherichia coli patog?nica aviar (APEC) puede afectar de manera severa a la producci?n av?cola. Las plantas de incubaci?n son la fuente principal de pollos para las granjas comerciales. Para caracterizar la patogenicidad potencial de las cepas de E. coli aisladas de las plantas de incubaci?n, se recolectaron 2344 muestras de plum?n de pollos de un d?a de edad de plantas de incubaci?n entre octubre del 2016 a noviembre del 2017. Entre las plantas de incubaci?n, la incidencia de E. coli fue del cero por ciento hasta el 16.9%, con una incidencia global del 2.0%. Las altas incidencias reflejaron una sanidad inadecuada en algunas plantas. Tambi?n se compararon 20 cepas de E. coli patog?nica aviar aisladas de casos cl?nicos con E. coli originada del plum?n con relaci?n a la presencia de 10 genes asociados a la virulencia (VAG), con genes asociados con la resistencia a los antimicrobianos y se evalu? la resistencia a los antimicrobianos mediante valores de concentraci?n m?nima inhibitoria (MIC). Los resultados mostraron que la E. coli patog?nica aviar pose?a con mayor frecuencia la mayor?a de los genes asociados con virulencia evaluados (papC, astA, cvaC, hlyF, fyuA, iroN, iutA, iss y ompT), lo que sugiere que la E. coli originada del plum?n es menos probable que cause colibacilosis aviar. Sin embargo, la E. coli originada de plum?n expres? con mayor frecuencia el gene de adhesi?n fimC, que podr?a conferir una mayor adhesi?n en el tracto respiratorio superior. Tanto la E. coli patog?nica aviar como la E. coli originada del plum?n demostraron resistencia a m?ltiples f?rmacos, incluida una resistencia del 100% a la ampicilina, amoxicilina, cefalexina, florfenicol y trimetoprimsulfametoxazol. Con base la mediana de los valores de la concentraci?n m?nima inhibitoria, la E. coli originada del plum?n fue m?s susceptible a los antibi?ticos. Sin embargo, la existencia del gene de resistencia no fue diferente significativamente entre los grupos, lo que sugiere que la E. coli originada del plum?n puede ser un problema de salud p?blica. El subtipo molecular con electroforesis en gel de campo pulsado digerido con XbaI revel? que solo unas pocas cepas mostraron patrones id?nticos, lo que indica que una variedad de fuentes de contaminaci?n estaban presentes en las plantas de incubaci?n individuales. Las cepas id?nticas dentro de la misma planta de incubaci?n pueden indicar transmisi?n vertical a partir de las parvadas paternas. En general, este es el primer estudio en caracterizar E. coli originada del plum?n. Estos resultados sugieren que tiene una patogenicidad m?s baja que la E. coli patog?nica aviar y que se debe realizar una limpieza y desinfecci?n exhaustivas para reducir la aparici?n de E. coli originada de plum?n en las plantas de incubaci?n.
Subjects
antimicrobial resistance; Escherichia coli; fluff; hatcheries; molecular subtyping; virulence-associated genes
SDGs
Other Subjects
antiinfective agent; virulence factor; animal; animal husbandry; antibiotic resistance; bird disease; chicken; Escherichia coli; Escherichia coli infection; feather; genetics; incidence; microbiology; newborn; pathogenicity; physiology; prevalence; pulsed field gel electrophoresis; Taiwan; veterinary medicine; virulence; Animal Husbandry; Animals; Animals, Newborn; Anti-Bacterial Agents; Chickens; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Feathers; Incidence; Poultry Diseases; Prevalence; Taiwan; Virulence; Virulence Factors
Type
journal article