Characteristics of colistin-resistant Escherichia coli from pig farms in Central China
Abstract The emergence and dissemination of colistin resistance in Enterobacteriaceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health. In this study, we isolated and characterized colistin-resistant and/or mcr-positive E. coli from pig farms in Central China. B...
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| Format: | Article |
| Language: | English |
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BMC
2021-07-01
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| Series: | Animal Diseases |
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| Online Access: | https://doi.org/10.1186/s44149-021-00009-5 |
| _version_ | 1818918955245371392 |
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| author | Zhong Peng Xiaoxue Zhang Xiaosong Li Zizhe Hu Zugang Li Chaoying Jia Menghong Dai Chen Tan Huanchun Chen Xiangru Wang |
| author_facet | Zhong Peng Xiaoxue Zhang Xiaosong Li Zizhe Hu Zugang Li Chaoying Jia Menghong Dai Chen Tan Huanchun Chen Xiangru Wang |
| author_sort | Zhong Peng |
| collection | DOAJ |
| description | Abstract The emergence and dissemination of colistin resistance in Enterobacteriaceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health. In this study, we isolated and characterized colistin-resistant and/or mcr-positive E. coli from pig farms in Central China. Between 2018 and 2019, 594 samples were collected and recovered 445 E. coli isolates. Among them, 33 with colistin resistance phenotypes and 37 that were positive for mcr genes were identified, including 34 positive for mcr-1, one positive for mcr-3, and two positive for both mcr-1 and mcr-3. An insertion of nine bases (“CTGGATACG”) into mcr-1 in four mcr-positive isolates led to gene dysfunction, and therefore did not confer the colistin resistance phenotype. Antimicrobial susceptibility testing revealed that 37 mcr-positive isolates showed severe drug resistance profiles, as 50% of them were resistant to 20 types of antibiotics. Multilocus sequence typing revealed a heterogeneous group of sequence types in mcr-positive isolates, among which ST10 (5/37), ST156 (5/37), and ST617 (4/37) were the predominant types. Plasmid conjugation assays showed that mcr-carrying plasmids of 25 mcr-positive isolates were conjugated with E. coli recipient, with conjugation frequencies ranging from 1.7 × 10-6 to 4.1 × 10-3 per recipient. Conjugation of these mcr genes conferred a colistin resistance phenotype upon the recipient bacterium. PCR typing of plasmids harbored in the 25 transconjugants determined six types of plasmid replicons, including IncX4 (14/25), FrepB (4/25), IncI2 (3/25), IncHI2 (2/25), FIB (1/25), and IncI1 (1/25). This study contributes to the current understanding of antibiotic resistance and molecular characteristics of colistin-resistant E. coli in pig farms. |
| first_indexed | 2024-12-20T00:58:11Z |
| format | Article |
| id | doaj.art-f9888170620446f88b48d83c010f0058 |
| institution | Directory Open Access Journal |
| issn | 2731-0442 |
| language | English |
| last_indexed | 2024-12-20T00:58:11Z |
| publishDate | 2021-07-01 |
| publisher | BMC |
| record_format | Article |
| series | Animal Diseases |
| spelling | doaj.art-f9888170620446f88b48d83c010f00582022-12-21T19:59:04ZengBMCAnimal Diseases2731-04422021-07-011111110.1186/s44149-021-00009-5Characteristics of colistin-resistant Escherichia coli from pig farms in Central ChinaZhong Peng0Xiaoxue Zhang1Xiaosong Li2Zizhe Hu3Zugang Li4Chaoying Jia5Menghong Dai6Chen Tan7Huanchun Chen8Xiangru Wang9State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityKey Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityState Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityAbstract The emergence and dissemination of colistin resistance in Enterobacteriaceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health. In this study, we isolated and characterized colistin-resistant and/or mcr-positive E. coli from pig farms in Central China. Between 2018 and 2019, 594 samples were collected and recovered 445 E. coli isolates. Among them, 33 with colistin resistance phenotypes and 37 that were positive for mcr genes were identified, including 34 positive for mcr-1, one positive for mcr-3, and two positive for both mcr-1 and mcr-3. An insertion of nine bases (“CTGGATACG”) into mcr-1 in four mcr-positive isolates led to gene dysfunction, and therefore did not confer the colistin resistance phenotype. Antimicrobial susceptibility testing revealed that 37 mcr-positive isolates showed severe drug resistance profiles, as 50% of them were resistant to 20 types of antibiotics. Multilocus sequence typing revealed a heterogeneous group of sequence types in mcr-positive isolates, among which ST10 (5/37), ST156 (5/37), and ST617 (4/37) were the predominant types. Plasmid conjugation assays showed that mcr-carrying plasmids of 25 mcr-positive isolates were conjugated with E. coli recipient, with conjugation frequencies ranging from 1.7 × 10-6 to 4.1 × 10-3 per recipient. Conjugation of these mcr genes conferred a colistin resistance phenotype upon the recipient bacterium. PCR typing of plasmids harbored in the 25 transconjugants determined six types of plasmid replicons, including IncX4 (14/25), FrepB (4/25), IncI2 (3/25), IncHI2 (2/25), FIB (1/25), and IncI1 (1/25). This study contributes to the current understanding of antibiotic resistance and molecular characteristics of colistin-resistant E. coli in pig farms.https://doi.org/10.1186/s44149-021-00009-5Escherichia coliColistin resistancemcr positivityAntimicrobial resistanceSequence typesPlasmid types |
| spellingShingle | Zhong Peng Xiaoxue Zhang Xiaosong Li Zizhe Hu Zugang Li Chaoying Jia Menghong Dai Chen Tan Huanchun Chen Xiangru Wang Characteristics of colistin-resistant Escherichia coli from pig farms in Central China Animal Diseases Escherichia coli Colistin resistance mcr positivity Antimicrobial resistance Sequence types Plasmid types |
| title | Characteristics of colistin-resistant Escherichia coli from pig farms in Central China |
| title_full | Characteristics of colistin-resistant Escherichia coli from pig farms in Central China |
| title_fullStr | Characteristics of colistin-resistant Escherichia coli from pig farms in Central China |
| title_full_unstemmed | Characteristics of colistin-resistant Escherichia coli from pig farms in Central China |
| title_short | Characteristics of colistin-resistant Escherichia coli from pig farms in Central China |
| title_sort | characteristics of colistin resistant escherichia coli from pig farms in central china |
| topic | Escherichia coli Colistin resistance mcr positivity Antimicrobial resistance Sequence types Plasmid types |
| url | https://doi.org/10.1186/s44149-021-00009-5 |
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