Genetic Characterization of the blaTEM Gene in Escherichia coli Isolated from Pork and Slaughterhouse Environments in the Mekong Delta
Downloads
This study aimed to characterize the genetic features of the antibiotic resistance gene blaTEM in Escherichia coli isolates recovered from pork and slaughterhouse environments in the Mekong Delta, Vietnam. A total of 435 E. coli isolates recovered from feces, pork carcasses, wastewater, and slaughterhouse floor surfaces were screened for the blaTEM gene using polymerase chain reaction (PCR). Ten representative blaTEM-positive isolates were selected for nucleotide sequencing. The obtained sequences were analyzed using BioEdit and MEGA 11 to determine nucleotide sequence identity and reconstruct a phylogenetic tree using the Neighbor-Joining method with 1,000 bootstrap replicates. The blaTEM gene was detected in 117 of 435 (26.90%) E. coli isolates. The prevalence of blaTEM among sample types ranged from 16.67% to 29.33%, with no statistically significant differences (P > 0.05). Nucleotide sequence analysis revealed a high degree of sequence identity (99.992–100.000%) among the 10 representative isolates. Phylogenetic analysis grouped the sequences into two major genetic clusters with short genetic distances. No clustering according to sample origin was observed, indicating that the blaTEM gene is highly conserved among E. coli isolates circulating within the slaughterhouse environment.
Bajaj, P., Singh, N. S., and Virdi, J. S. (2016). Escherichia coli β-lactamases: What really matters. Frontiers in Microbiology, 7, 417. https://doi.org/10.3389/fmicb.2016.00417
Bradford, P. A. (2001). Extended-spectrum β-lactamases in the 21st century: Characterization, epidemiology, and detection of this important resistance threat. Clinical Microbiology Reviews, 14(4), 933–951. https://doi.org/10.1128/CMR.14.4.933-951.2001
Caniça, M. M., Lu, C. Y., Krishnamoorthy, R., & Paul, G. (1997). Molecular diversity and evolution of blaTEM genes encoding β-lactamases resistant to clavulanic acid in clinical Escherichia coli. Journal of Molecular Evolution, 44(1), 57–65. https://doi.org/10.1007/PL00006118
Carattoli, A. (2013). Plasmids and the spread of resistance. International Journal of Medical Microbiology, 303(6–7), 298–304. https://doi.org/10.1016/j.ijmm.2013.02.001
Carroll, L. M., Wiedmann, M., Mukherjee, M., et al. (2021). Whole-genome sequencing for surveillance of antimicrobial resistance: Current status and future prospects. Clinical Microbiology Reviews, 34(4), e00105-19. https://doi.org/10.1128/CMR.00105-19
Dorado-García, A., Smid, J. H., van Pelt, W., et al. (2018). Molecular relatedness of ESBL/AmpC-producing Escherichia coli from humans, animals, food and the environment: A pooled analysis. Clinical Microbiology and Infection, 24(8), 904–913. https://doi.org/10.1016/j.cmi.2017.10.030
Hall, B. G., Barlow, M., & Smith, H. (2013). Evolution of the serine β-lactamases: Past, present and future. Drug Resistance Updates, 16(4–5), 105–117. https://doi.org/10.1016/j.drup.2013.08.002
Hu Z., et al. (2021). Prevalence and Molecular Characterization of Antimicrobial-Resistant Escherichia coli in Pig Farms, Slaughterhouses, and Terminal Markets in Henan Province of China. Foodborne Pathogens and Disease, 18(10). DOI: 10.1089/fpd.2021.0011.
Leverstein-van Hall, M. A., Dierikx, C. M., Stuart, J. C., et al. (2011). Dutch patients, retail chicken meat and poultry share the same ESBL genes, plasmids and strains. Clinical Microbiology and Infection, 17(6), 873–880. https://doi.org/10.1111/j.1469-0691.2011.03497.x
Madec, J. Y., Haenni, M., Nordmann, P., & Poirel, L. (2017). Extended-spectrum β-lactamase/AmpC- and carbapenemase-producing Enterobacteriaceae in animals: A threat for humans? Clinical Microbiology Reviews, 30(4), 881–919. https://doi.org/10.1128/CMR.00110-16
Paterson, D. L., & Bonomo, R. A. (2005). Extended-spectrum β-lactamases: A clinical update. Clinical Microbiology Reviews, 18(4), 657–686. https://doi.org/10.1128/CMR.18.4.657-686.2005
Poirel, L., Madec, J. Y., Lupo, A., Schink, A. K., Kieffer, N., Nordmann, P., & Schwarz, S. (2018). Antimicrobial resistance in Escherichia coli. Microbiology Spectrum, 6(4). https://doi.org/10.1128/microbiolspec.ARBA-0026-2017
Silva, A.; Silva, V.; Pereira, J.E.; Maltez, L.; Igrejas, G.;Valentão, P.; Falco, V.; Poeta, P. Antimicrobial Resistance and Clonal Lineages of Escherichia coli from Food-Producing Animals. Antibiotics 2023, 12, 1061. https://doi.org/ 10.3390/antibiotics12061061
The hidden threat: Comprehensive assessment of antibiotic and disinfectant resistance in commercial pig slaughterhouses. Science of the Total Environment, 2024. DOI: 10.1016/j.scitotenv.2024.174222.
Thong N.V., Thuan.N.K., Minh.B.T.L (2025). Prevalence of antibiotic resistance genes of Escherichia coli at the pig slaughterhouses in the Mekong Delta. Veterinary Integrative Sciences, 23. DOI: 10.12982/VIS.2025.005.
Thuan N.K., Linh D.C., Tuyen.N.H.T and Minh B.T.L. (2024). Prevalence of some pathogenic and antibiotic resistance genes of Escherichia coli isolated from pig slaughterhouses in An Giang province. Journal of Science Can Tho University, 60(5):91–100. DOI: 10.22144/ctujos.2024.411.
WHO (World Health Organization). (2024). Global Antimicrobial Resistance and Use Surveillance System (GLASS) report 2024. World Health Organization.
Yang H., Wei. S.H., Hobman. J.L., Dodd.C.E.R (2020). Antibiotic and Metal Resistance in Escherichia coli Isolated from Pig Slaughterhouses in the United Kingdom. Antibiotics, 9(11):746. DOI: 10.3390/antibiotics9110746.
Copyright (c) 2026 Ngo Văn Thong; Tran Thi Huu Hanh
This work is licensed under a Creative Commons Attribution 4.0 International License.
All Content should be original and unpublished.
