Minh Ngoc Nguyen1, Ha Thi Thu Hoang2, Basil Britto Xavier1, Christine Lammens1, Hai Thanh Le3, Ngoc Thi Bich Hoang3, Son Thai Nguyen4, Ngoc Thi Pham5, Herman Goossens1, Anh Duc Dang3, Surbhi Malhotra-Kumar6. 1. Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium. 2. National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam. 3. Vietnam National Children's Hospital, Hanoi, Viet Nam. 4. Military Hospital 103, Hanoi, Viet Nam. 5. National Institute of Veterinary Research, Hanoi, Viet Nam. 6. Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium. Electronic address: surbhi.malhotra@uantwerpen.be.
Abstract
OBJECTIVES: We performed a One Health surveillance in Hanoi-a region with a high-density human population and livestock production, and a recognized hotspot of animal-associated antimicrobial resistance (AMR)-to study the contribution of blaCTX-M-carrying Escherichia coli and plasmids from food-animal sources in causing human community-acquired urinary tract infections (CA-UTIs). METHODS: During 2014-2015, 9090 samples were collected from CA-UTI patients (urine, n = 8564), pigs/chickens from farms and slaughterhouses (faeces, carcasses, n = 448), and from the slaughterhouse environment (surface swabs, water, n = 78). E. coli was identified in 2084 samples. Extended-spectrum β-lactamase (ESBL) production was confirmed in 235 and blaCTX-M in 198 strains by PCR with short-read plasmid sequencing. Fourteen strains were long-read sequenced to enable plasmid reconstruction. RESULTS: The majority of the ESBL-producing E. coli strains harboured blaCTX-M (n = 198/235, 84%). High clonal diversity (48 sequence types, STs) and distinct, dominant STs in human sources (ST1193, n = 38/137; ST131, n = 30/137) and non-human sources (ST155, n = 25/61) indicated lack of clonal transmission between habitats. Eight blaCTX-M variants were identified; five were present in at least two sample sources. Human and food-animal strains did not show similar plasmids carrying shared blaCTX-M genes. However, IS6 elements flanking ISEcp1-blaCTX-M-orf477/IS903B structures were common across habitats. CONCLUSIONS: In this study, animal-associated blaCTX-ME. coli strains or blaCTX-M plasmids were not direct sources of CA-UTIs or ESBL resistance in humans, respectively, suggesting evolutionary bottlenecks to their adaptation to a new host species. Presence of common IS6 elements flanking blaCTX-M variants in different plasmid backbones, however, highlighted the potential of these transposable elements for AMR transmission either within or across habitats.
OBJECTIVES: We performed a One Health surveillance in Hanoi-a region with a high-density human population and livestock production, and a recognized hotspot of animal-associated antimicrobial resistance (AMR)-to study the contribution of blaCTX-M-carrying Escherichia coli and plasmids from food-animal sources in causing human community-acquired urinary tract infections (CA-UTIs). METHODS: During 2014-2015, 9090 samples were collected from CA-UTI patients (urine, n = 8564), pigs/chickens from farms and slaughterhouses (faeces, carcasses, n = 448), and from the slaughterhouse environment (surface swabs, water, n = 78). E. coli was identified in 2084 samples. Extended-spectrum β-lactamase (ESBL) production was confirmed in 235 and blaCTX-M in 198 strains by PCR with short-read plasmid sequencing. Fourteen strains were long-read sequenced to enable plasmid reconstruction. RESULTS: The majority of the ESBL-producing E. coli strains harboured blaCTX-M (n = 198/235, 84%). High clonal diversity (48 sequence types, STs) and distinct, dominant STs in human sources (ST1193, n = 38/137; ST131, n = 30/137) and non-human sources (ST155, n = 25/61) indicated lack of clonal transmission between habitats. Eight blaCTX-M variants were identified; five were present in at least two sample sources. Human and food-animal strains did not show similar plasmids carrying shared blaCTX-M genes. However, IS6 elements flanking ISEcp1-blaCTX-M-orf477/IS903B structures were common across habitats. CONCLUSIONS: In this study, animal-associated blaCTX-ME. coli strains or blaCTX-M plasmids were not direct sources of CA-UTIs or ESBL resistance in humans, respectively, suggesting evolutionary bottlenecks to their adaptation to a new host species. Presence of common IS6 elements flanking blaCTX-M variants in different plasmid backbones, however, highlighted the potential of these transposable elements for AMR transmission either within or across habitats.