The increased prevalence of antimicrobial resistance (AMR) among Enterobacteriaceae has had major clinical and economic impacts on human medicine. Many of the multidrug-resistant (multiresistant) Enterobacteriaceae found in humans are community acquired, and some of them are possibly linked to food animals (i.e., livestock raised for meat and dairy products). In this study, we examined whether numerically dominant commensal Escherichia coli strains from humans (n = 63 isolates) and domestic animals (n = 174 isolates) in the same community and with matching phenotypic AMR patterns were clonally related or shared the same plasmids. We identified 25 multiresistant isolates (i.e., isolates resistant to more than one antimicrobial) that shared identical phenotypic resistance patterns. We then investigated the diversity of E. coli clones, AMR genes, and plasmids carrying the AMR genes using conjugation, replicon typing, and whole-genome sequencing. All of the multiresistant E. coli isolates (from children and domestic animals) analyzed had at least 90 or more whole-genome SNP differences between one another, suggesting that none of the strains was recently transferred. While the majority of isolates shared the same antimicrobial resistance genes and replicons, DNA sequencing indicated that these genes and replicons were found on different plasmid structures. We did not find evidence of the clonal spread of AMR in this community: instead, AMR genes were carried on diverse clones and plasmids. This presents a significant challenge for understanding the movement of AMR in a community. IMPORTANCE Even though Escherichia coli strains may share nearly identical phenotypic AMR profiles and AMR genes and overlap in space and time, the diversity of clones and plasmids challenges research that aims to identify sources of AMR. Horizontal gene transfer appears to play a more significant role than clonal expansion in the spread of AMR in this community.

Background: There is a significant gap in our understanding of the sources of multidrug-resistant bacteria and resistance genes in community settings where human–animal interfaces exist. Objectives: This study characterized the relationship of third-generation cephalosporin-resistant Escherichia coli (3GCR-EC) isolated from animal feces in the environment and child feces based on phenotypic antimicrobial resistance (AMR) and whole genome sequencing (WGS). Methods: We examined 3GCR-EC isolated from environmental fecal samples of domestic animals and child fecal samples in Ecuador. We analyzed phenotypic and genotypic AMR, as well as clonal relationships (CRs) based on pairwise single-nucleotide polymorphisms (SNPs) analysis of 3GCR-EC core genomes. CRs were defined as isolates with fewer than 100 different SNPs. Results: A total of 264 3GCR-EC isolates from children ( ), dogs ( ), and chickens ( ) living in the same region of Quito, Ecuador, were identified. We detected 16 CRs total, which were found between 7 children and 5 domestic animals (5 CRs) and between 19 domestic animals (11 CRs). We observed that several clonally related 3GCR-EC isolates had acquired different plasmids and AMR genes. Most CRs were observed in different homes ( ) at relatively large distances. Isolates from children and domestic animals shared the same allelic variants, and the most prevalent were and , which were found in isolates from children, dogs, and chickens. Discussion: This study provides evidence of highly dynamic horizontal transfer of AMR genes and mobile genetic elements (MGEs) in the E. coli community and shows that some 3GCR-EC and (extended-spectrum ) ESBL genes may have moved relatively large distances among domestic animals and children in semirural communities near Quito, Ecuador. Child–animal contact and the presence of domestic animal feces in the environment potentially serve as important sources of drug-resistant bacteria and ESBL genes. https://doi.org/10.1289/EHP7729

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Domestic animals in the household environment have the potential to affect a child's carriage of zoonotic enteric pathogens and risk of diarrhea. This study examines the risk factors associated with pediatric diarrhea and carriage of zoonotic enteric pathogens among children living in communities where smallholder livestock production is prevalent. We conducted an observational study of children younger than 5 years that included the analysis of child (n = 306) and animal (n = 480) fecal samples for Campylobacter spp., atypical enteropathogenic Escherichia coli, Shiga toxin-producing E. coli, Salmonella spp., Yersinia spp., Cryptosporidium parvum, and Giardia lamblia. Among these seven pathogens, Giardia was the most commonly identified pathogen among children and animals in the same household, most of which was found in child-dog pairs. Campylobacter spp. was also relatively common within households, particularly among child-chicken and child-guinea pig pairs. We used multivariable Poisson regression models to assess risk factors associated with a child being positive for at least one zoonotic enteric pathogen or having diarrhea during the last week. Children who interacted with domestic animals-a behavior reported by nearly three-quarters of households owning animals-were at an increased risk of colonization with at least one zoonotic enteric pathogen (prevalence ratio [PR] = 1.56, 95% CI: 1.00-2.42). The risk of diarrhea in the last seven days was elevated but not statistically significant (PR = 2.27, CI: 0.91, 5.67). Interventions that aim to reduce pediatric exposures to enteric pathogens will likely need to be incorporated with approaches that remove animal fecal contamination from the domestic environment and encourage behavior change aimed at reducing children's contact with animal feces through diverse exposure pathways.

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL), a family of bacteria that includes Escherichia coli, have emerged as a global health threat. This study examined risks associated with carriage of third-generation cephalosporin-resistant (3GC-R) E. coli, including ESBL-producing, multidrug-resistant, and extensively drug-resistant (XDR) strains in children living in semirural parishes of Quito, Ecuador. We conducted a longitudinal study with two cycles of sampling (N = 374, N = 366) that included an analysis of child fecal samples and survey questions relating to water, sanitation, and hygiene, socioeconomic status, household crowding, and animal ownership. We used multivariate regression models to assess risk factors associated with a child being colonized. Across the two cycles, 18.4% (n = 516) of the 3GC-R isolates were ESBL-producing E. coli, and 40.3% (n = 516) were XDR E. coli. Children living in households that owned between 11 and 20 backyard animals had an increased odds of being colonized with XDR E. coli (odds ratio [OR] = 1.94, 95% confidence interval [CI]: 1.05–3.60) compared with those with no animals. Households that reported smelling odors from commercial poultry had increased odds of having a child positive for XDR E. coli (OR = 1.72, 95% CI: 1.11–2.66). Our results suggest that colonization of children with antimicrobial-resistant E. coli is influenced by exposure to backyard and commercial livestock and poultry. Future studies should consider community-level risk factors because child exposures to drug-resistant bacteria are likely influenced by neighborhood and regional risk factors.

Background The rapid spread of extended-spectrum beta-lactamase-producing E. coli (ESBL-EC) is an urgent global health threat. We examined child caretaker knowledge, attitudes, and practices (KAP) towards proper antimicrobial agent use and whether certain KAP were associated with ESBL-EC colonization of their children. Methods Child caretakers living in semi-rural neighborhoods in peri-urban Quito, Ecuador were visited and surveyed about their KAP towards antibiotics. Fecal samples from one child (less than 5 years of age) per household were collected at two time points between July 2018 and May 2019 and screened for ESBL-EC. A repeated measures analysis with logistic regression was used to assess the relationship between KAP levels and child colonization with ESBL-EC. Results We analyzed 740 stool samples from 444 children living in households representing a range of environmental conditions. Of 374 children who provided fecal samples at the first household visit, 44 children were colonized with ESBL-EC (11.8%) and 161 were colonized with multidrug-resistant E. coli (43%). The prevalences of ESBL-EC and multidrug-resistant E. coli were similar at the second visit (11.2% and 41.3%, respectively; N = 366). Only 8% of caretakers knew that antibiotics killed bacteria but not viruses, and over a third reported that they “always” give their children antibiotics when the child’s throat hurts (35%). Few associations were observed between KAP variables and ESBL-EC carriage among children. The odds of ESBL-EC carriage were 2.17 times greater (95% CI: 1.18–3.99) among children whose caregivers incorrectly stated that antibiotics do not kill bacteria compared to children whose caregivers correctly stated that antibiotics kill bacteria. Children from households where the caretaker answered the question “When your child’s throat hurts, do you give them antibiotics?” with “sometimes” had lower odds of ESBL-EC carriage than those with a caretaker response of “never” (OR 0.48, 95% CI 0.27–0.87). Conclusion Caregivers in our study population generally demonstrated low knowledge regarding appropriate use of antibiotics. Our findings suggest that misinformation about the types of infections (i.e. bacterial or viral) antibiotics should be used for may be associated with elevated odds of carriage of ESBL-EC. Understanding that using antibiotics is appropriate to treat infections some of the time may reduce the odds of ESBL-EC carriage. Overall, however, KAP measures of appropriate use of antibiotics were not strongly associated with ESBL-EC carriage. Other individual- and community-level environmental factors may overshadow the effect of KAP on ESBL-EC colonization. Intervention studies are needed to assess the true effect of improving KAP on laboratory-confirmed carriage of antimicrobial resistant bacteria, and should consider community-level studies for more effective management.

The increased prevalence of antimicrobial resistance (AMR) among Enterobacteriaceae has had major clinical and economic impacts in human medicine. Many of the multi-drug resistant (MDR) Enterobacteriaceae found in humans are community-acquired and linked to food animals (i.e. livestock raised for meat and dairy products). In this study, we examined whether numerically dominant, commensal Escherichia coli strains from humans (n=63 isolates) and domestic animals (n=174 isolates) in the same community and with matching phenotypic AMR patterns, were clonally related or shared the same plasmids. We identified 25 multi-drug resistant isolates (i.e. resistant to 3 or more antimicrobial classes) that shared identical phenotypic resistance patterns. We then investigated the diversity of E. coli clones, AMR genes and plasmids carrying the AMR genes using conjugation, replicon typing and whole genome sequencing. None of the MDR E. coli isolates (from children and domestic animals) analyzed were clonal. While the majority of isolates shared the same antimicrobial resistance genes and replicons, DNA sequencing indicated that these genes and replicons were found on different plasmid structures. Our findings suggest that nonclonal resistance gene dissemination is common in this community and that diverse plasmids carrying AMR genes presents a significant challenge for understanding the movement of AMR in a community.IMPORTANCEEven though Escherichia coli strains may share nearly identical AMR profiles, AMR genes, and overlap in space and time, the diversity of clones and plasmids challenges to research that aims to identify sources of AMR. Horizontal gene transfer appears to play a much larger role than clonal expansion in the spread of AMR in the community.

Extended-spectrum β-lactamase (ESBL)-producing and other antimicrobial resistant (AR) Escherichia coli threaten human and animal health worldwide. This study examined risk factors for domestic animal colonization with ceftriaxone-resistant (CR) and ESBL-producing E. coli in semirural parishes east of Quito, Ecuador, where small-scale food animal production is common. Survey data regarding household characteristics, animal care, and antimicrobial use were collected from 304 households over three sampling cycles, and 1195 environmental animal fecal samples were assessed for E. coli presence and antimicrobial susceptibility. Multivariable regression analyses were used to assess potential risk factors for CR and ESBL-producing E. coli carriage. Overall, CR and ESBL-producing E. coli were detected in 56% and 10% of all fecal samples, respectively. The odds of CR E. coli carriage were greater among dogs at households that lived within a 5 km radius of more than 5 commercial food animal facilities (OR 1.72, 95% CI 1.15–2.58) and lower among dogs living at households that used antimicrobials for their animal(s) based on veterinary/pharmacy recommendation (OR 0.18, 95% CI 0.04–0.96). Increased odds of canine ESBL-producing E. coli carriage were associated with recent antimicrobial use in any household animal (OR 2.69, 95% CI 1.02–7.10) and purchase of antimicrobials from pet food stores (OR 6.83, 95% CI 1.32–35.35). Food animals at households that owned more than 3 species (OR 0.64, 95% CI 0.42–0.97), that used antimicrobials for growth promotion (OR 0.41, 95% CI 0.19–0.89), and that obtained antimicrobials from pet food stores (OR 0.47, 95% CI 0.25–0.89) had decreased odds of CR E. coli carriage, while food animals at households with more than 5 people (OR 2.22, 95% CI 1.23–3.99) and located within 1 km of a commercial food animal facility (OR 2.57, 95% CI 1.08–6.12) had increased odds of ESBL-producing E. coli carriage. Together, these results highlight the complexity of antimicrobial resistance among domestic animals in this setting.