Salmonella Prevalence and antibiotic resistance profile in raw poultry meat sold in North Lebanon: Insights from the COVID-19 pandemic and economic crisis

Salmonella-related foodborne illness is a significant public health concern, with the primary source of human infection being animal-based food products, particularly chicken meat. Lebanon is currently experiencing a dual crisis: the COVID-19 pandemic and an unprecedented economic crisis, which has resulted in substantial challenges to the public health system and food safety. This study aims to assess the prevalence and antibiotic resistance profile of Salmonella in raw poultry meat sold in North Lebanon during this dual crisis. A cross-sectional study was carried out between May 2021 and April 2022 across six different districts in North Lebanon. A total of 288 whole, unprocessed chickens were examined. The isolation and identification of Salmonella isolates were done based on cultural and biochemical properties. All isolates were subjected to antimicrobial susceptibility testing and phenotypic assays for Extended-Spectrum Beta-lactamase (ESBL) detection. The prevalence of Salmonella in raw poultry meat purchased in North Lebanon reached 18.05 % (52/288). The dry season and chilled chicken were significantly associated with an increased risk of Salmonella contamination (P < 0.05). Additionally, 34.61 % of the isolates were potential ESBL producers, and 57.69 % exhibited multidrug resistance (MDR). This study highlights the existence of MDR in chicken meat in North Lebanon, posing a potential health risk if undercooked chicken meat is consumed. This emphasizes the importance of the implementation of preventive strategies and hygienic procedures throughout the food chain to reduce the risk of Salmonella spp. contamination in chicken meats and its potential transmission to humans.

Environment, animals, and food as reservoirs of antibiotic-resistant bacteria for humans: One health or more?

Antimicrobial resistance (AMR) is a major public health challenge. For several years, AMR has been addressed through a One Health approach that links human health, animal health, and environmental quality. In this review, we discuss AMR in different reservoirs with a focus on the environment. Anthropogenic activities produce effluents (sewage, manure, and industrial wastes) that contaminate soils and aquatic environments with antibiotic-resistant bacteria (ARB), antibiotic-resistant genes (ARGs), and selective agents such as antibiotics, biocides, and heavy metals. Livestock treated with antibiotics can also contaminate food with ARB. In high-income countries (HICs), effective sanitation infrastructure and limited pharmaceutical industries result in more controlled discharges associated with human activities. Hence, studies using genome-based typing methods have revealed that, although rare inter-reservoir transmission events have been reported, human acquisition in HICs occurs primarily through person-to-person transmission. The situation is different in low- and middle-income countries (LMICs) where high population density, poorer sanitation and animal farming practices are more conducive to inter-reservoir transmissions. In addition, environmental bacteria can be a source of ARGs that, when transferred to pathogenic species under antibiotic selection pressure in environmental hotspots, produce new antibiotic-resistant strains that can potentially spread in the human community through human-to-human transmission. The keys to reducing AMR in the environment are (i) better treatment of human waste by improving wastewater treatment plants (WWTPs) in HICs and improving sanitation infrastructure in LMICs, (ii) reducing the use of antibiotics by humans and animals, (iii) prioritizing the use of less environmentally harmful antibiotics, and (iv) better control of pharmaceutical industry waste.

Global antimicrobial resistance and use surveillance system (GLASS 2022): Investigating the relationship between antimicrobial resistance and antimicrobial consumption data across the participating countries

For the first time since 2015, the World Health Organization's (WHO) global Antimicrobial Resistance and Use Surveillance (GLASS) featured both global reports for antimicrobial resistance (AMR) and antimicrobial consumption (AMC) data in its annual reports. In this study we investigated the relationship of AMR with AMC within participating countries reported in the GLASS 2022 report. Our analysis found a statistically significant correlation between beta-lactam/cephalosporin and fluoroquinolones consumption and AMR to these antimicrobials associated with bloodstream E. coli and Klebsiella pneumoniae among the participating countries (P<0.05). We observed that for every 1 unit increase in defined daily dose DDD of beta-lactam/cephalosporins and quinolone consumptions among the countries, increased the recoveries of bloodstream-associated beta-lactam/cephalosporins-resistant E. coli/Klebsiella spp. by 11-22% and quinolone-resistant E. coli/Klebsiella spp. by 31-40%. When we compared the antimicrobial consumptions between the antimicrobial ATC (Alphanumeric codes developed by WHO) groups and countries, we observed a statistically significant higher daily consumption of beta-lactam-penicillins (J01C, DDD difference range: 5.23-8.13) and cephalosporins (J01D, DDD difference range: 2.57-5.13) compared to other antimicrobial groups among the countries (adjusted for multiple comparisons using Tukey's method). Between the participating countries, we observed a statistically significant higher daily consumption of antimicrobial groups in Iran (DDD difference range: 3.63-4.84) and Uganda (DDD difference range: 3.79-5.01) compared to other participating countries (adjusted for multiple comparisons using Tukey's method). Understanding AMC and how it relates to AMR at the global scale is critical in the global AMR policy development and implementation of global antimicrobial stewardship.

Antimicrobial resistance of avian pathogenic Escherichia coli isolated from broiler, layer, and breeder chickens

Background and Aim

Antimicrobials are extensively used in poultry production for growth promotion as well as for the treatment and control of diseases, including avian pathogenic Escherichia coli (APEC). Poor selection, overuse, and misuse of antimicrobial agents may promote the emergence and dissemination of antimicrobial resistance (AMR) in APEC. This study aimed to assess antimicrobial susceptibility patterns and detect antibiotic resistance genes (ARGs) in APEC isolated from clinical cases of colibacillosis in commercial broiler, layer, and breeder chickens.

Materials and Methods

A total of 487 APEC were isolated from 539 across 300 poultry farms in various regions of Nepal. Antimicrobial susceptibility patterns was determined using the Kirby-Bauer disk diffusion and broth microdilution methods. The index of AMR, such as multiple antibiotic resistance (MAR) index, resistance score (R-score), and multidrug resistance (MDR) profile, were determined. Polymerase chain reaction was employed to detect multiple ARGs and correlations between phenotypic and genotypic resistance were analyzed.

Results

The prevalence of APEC was 91% (487/539). All of these isolates were found resistant to at least one antimicrobial agent, and 41.7% of the isolates were resistant against 8-9 different antimicrobials. The antibiogram of APEC isolates overall showed the highest resistance against ampicillin (99.4%), whereas the highest intermediate resistance was observed in enrofloxacin (92%). The MAR index and R-score showed significant differences between broiler and layers, as well as between broiler breeder and layers. The number of isolates that were resistant to at least one agent in three or more antimicrobial categories tested was 446 (91.6%) and were classified as MDR-positive isolates. The ARGs were identified in 439 (90.1%) APEC isolates, including the most detected mobilized colistin resistance (mcr1) which was detected in the highest (52.6%) isolates. Overall, resistance gene of beta-lactam (blaTEM), mcr1, resistance gene of sulphonamide (sul1) and resistance gene of tetracycline (tetB) (in broiler), were detected in significantly higher than other tested genes (p < 0.001). When examining the pair-wise correlations, a significant phenotype-phenotype correlation (p < 0.001) was observed between levofloxacin and ciprofloxacin, chloramphenicol and tetracycline with doxycycline. Similarly, a significant phenotype-genotype correlation (p < 0.001) was observed between chloramphenicol and the tetB, and colistin with blaTEM and resistance gene of quinolone (qnrA).

Conclusion

In this study, the current state of APEC AMR in commercial chickens is revealed for the first time in Nepal. We deciphered the complex nature of AMR in APEC populations. This information of molecular surveillance is useful to combat AMR in APEC and to contribute to manage APEC associated diseases and develop policies and guidelines to enhance the commercial chicken production.

Associations between Isolation Source, Clonal Composition, and Antibiotic Resistance Genes in Escherichia coli Collected in Washington State, USA

Antimicrobial resistance (AMR) is a global health problem stemming from the use of antibiotics in humans, animals, and the environment. This study used whole-genome sequencing (WGS) of E. coli to explore patterns of AMR across sectors in Washington State, USA (WA). The WGS data from 1449 E. coli isolates were evaluated for isolation source (humans, animals, food, or the environment) and the presence of antibiotic resistance genes (ARGs). We performed sequence typing using PubMLST and used ResFinder to identify ARGs. We categorized isolates as being pan-susceptible, resistant, or multidrug-resistant (MDR), defined as carrying resistance genes for at least three or more antimicrobial drug classes. In total, 60% of isolates were pan-susceptible, while 18% were resistant, and 22% exhibited MDR. The proportion of resistant isolates varied significantly according to the source of the isolates (p < 0.001). The greatest resistance was detected in isolates from humans and then animals, while environmental isolates showed the least resistance. This study demonstrates the feasibility of comparing AMR across various sectors in Washington using WGS and a One Health approach. Such analysis can complement other efforts for AMR surveillance and potentially lead to targeted interventions and monitoring activities to reduce the overall burden of AMR.

Prevalence and antimicrobial resistance profiles of extended-spectrum beta-lactamase-producing Escherichia coli in East Tennessee dairy farms

Introduction

The extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, such as Escherichia coli, are emerging as a serious threat to global health due to their rapid spread and their multidrug-resistant (MDR) phenotypes. However, limited information is available regarding the prevalence and antimicrobial resistance (AMR) profile of ESBL-E. coli in the United States dairy farms. This study aimed to determine the prevalence and AMR pattern of ESBL-E. coli in East Tennessee dairy cattle farms.

Methods

Rectal fecal samples from dairy cattle (n = 508) and manure (n = 30), water (n = 19), and feed samples (n = 15) were collected from 14 farms. The presumptive E. coli was isolated on CHROMagar™ ESBL and confirmed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing was performed on the ESBL-E. coli isolates.

Results and discussion

From 572 fecal and farm environmental samples, a total of 233 (41%, n = 572) ESBL-E. coli were identified. The prevalence of fecal ESBL-E. coli was 47.5% (95% CI: 46.2-49.2). The within-farm prevalence of ESBL-E. coli ranged from 8 to 100%. Recent treatment history with third-generation cephalosporins (3GC), cow parity ≥3, and calves were the independent risk factors associated (P < 0.05) with fecal carriage of ESBL-E. coli. Overall, 99.6% (n = 231) ESBL-E. coli tested were phenotypically resistant to at least one of the 14 antimicrobial agents tested. The most common AMR phenotypes were against beta-lactam antibiotics, ampicillin (99.1%; n = 231 isolates), and ceftriaxone (98.7%, n = 231). Most ESBL-E. coli isolates (94.4%) were MDR (resistance to ≥3 antimicrobial classes), of which 42.6% showed co-resistance to at least six classes of antimicrobials. ESBL-E. coli isolates with concurrent resistance to ceftriaxone, ampicillin, streptomycin, tetracycline, sulfisoxazole, and chloramphenicol are widespread and detected in all the farms. The detection of MDR ESBL-E. coli suggests that dairy cattle can be a reservoir for these bacteria, highlighting the associated public health risk.

One Health Determinants of Escherichia coli Antimicrobial Resistance in Humans in the Community: An Umbrella Review

To date, the scientific literature on health variables for Escherichia coli antimicrobial resistance (AMR) has been investigated throughout several systematic reviews, often with a focus on only one aspect of the One Health variables: human, animal, or environment. The aim of this umbrella review is to conduct a systematic synthesis of existing evidence on Escherichia coli AMR in humans in the community from a One Health perspective. PubMed, EMBASE, and CINAHL were searched on "antibiotic resistance" and "systematic review" from inception until 25 March 2022 (PROSPERO: CRD42022316431). The methodological quality was assessed, and the importance of identified variables was tabulated across all included reviews. Twenty-three reviews were included in this study, covering 860 primary studies. All reviews were of (critically) low quality. Most reviews focused on humans (20), 3 on animals, and 1 on both human and environmental variables. Antibiotic use, urinary tract infections, diabetes, and international travel were identified as the most important human variables. Poultry farms and swimming in freshwater were identified as potential sources for AMR transmission from the animal and environmental perspectives. This umbrella review highlights a gap in high-quality literature investigating the time between variable exposure, AMR testing, and animal and environmental AMR variables.

Extended-Spectrum β-Lactamases (ESBL): Challenges and Opportunities

The rise of antimicrobial resistance, particularly from extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-E), poses a significant global health challenge as it frequently causes the failure of empirical antibiotic therapy, leading to morbidity and mortality. The E. coli- and K. pneumoniae-derived CTX-M genotype is one of the major types of ESBL. Mobile genetic elements (MGEs) are involved in spreading ESBL genes among the bacterial population. Due to the rapidly evolving nature of ESBL-E, there is a lack of specific standard examination methods. Carbapenem has been considered the drug of first choice against ESBL-E. However, carbapenem-sparing strategies and alternative treatment options are needed due to the emergence of carbapenem resistance. In South Asian countries, the irrational use of antibiotics might have played a significant role in aggravating the problem of ESBL-induced AMR. Superbugs showing resistance to last-resort antibiotics carbapenem and colistin have been reported in South Asian regions, indicating a future bleak picture if no urgent action is taken. To counteract the crisis, we need rapid diagnostic tools along with efficient treatment options. Detailed studies on ESBL and the implementation of the One Health approach including systematic surveillance across the public and animal health sectors are strongly recommended. This review provides an overview of the background, associated risk factors, transmission, and therapy of ESBL with a focus on the current situation and future threat in the developing countries of the South Asian region and beyond.

The Susceptibility Trends of Respiratory and Enteric Porcine Pathogens to Last-Resource Antimicrobials

Monitoring the antimicrobial susceptibility of last-resource antimicrobials for veterinary pathogens is urgently needed from a one-health perspective. The objective of this study was to analyze the antimicrobial susceptibility trends of Spanish porcine bacteria to quinolones, cephalosporins, and polymyxins. Isolates of Actinobacillus pleuropneumoniae, Pasteurella multocida, and Escherichia coli were isolated from sick pigs from 2019 to 2022. An antimicrobial susceptibility test was determined based on the minimal inhibitory concentration (MIC) following an internationally accepted methodology. The MIC categorization was based on distributing the range of MIC values in four categories, with category one being the most susceptible (lowest MIC value) and category four the least susceptible (highest MIC value). Moreover, clinical susceptibility (susceptible/non-susceptible) was also determined according to the CLSI and EUCAST clinical breakpoints. A logistic and multinomial logistic regression model was used to analyze the susceptibility data for dichotomized and categorized MIC data, respectively, for any pair of antimicrobial/microorganism. In general terms, the antimicrobial susceptibility of pig bacteria to these antimicrobials remained stable or increased in the last four years in Spain. In the case of A. pleuropneumoniae and quinolones, a significant temporal trend was observed where isolates from 2020 had significantly increased odds of being more susceptible than isolates from 2019. In the case of E. coli and polymyxins, a significant temporal trend was observed where isolates from 2020 and 2021 had significantly increased odds of being more susceptible than isolates from 2019 and 2020, respectively. Finally, significant odds of being less susceptible were only observed for cephalosporins and E. coli for 2020 versus 2019, stagnating for the rest of study period. These results provide sound data on critically important antimicrobials in swine medicine.

Genome analysis of third-generation cephalosporin-resistant Escherichia coli and Salmonella species recovered from healthy and diseased food-producing animals in Europe

The animal reservoir of Enterobacterales producing Extended-Spectrum-β-Lactamases (ESBL) and plasmid-borne cephalosporinases (pAmpC) is a global concern. Using genome data, we analyzed a population of Escherichia coli and Salmonella species resistant to third-generation cephalosporins (3GC-R) recovered from healthy food animals (HA) and diseased food animals (DA) across Europe. Among the isolates collected from HA (n = 4,498) and DA (n = 833) in up to twelve European countries, 62 (1.4%) and 45 (5.4%) were 3GC-R, respectively. The genomes of these 3GC-R 107 isolates were sequenced to identify blaESBL and blaAmpC, sequence types (STs), virulence-associated genes, and Salmonella serovars. We also assessed their population structure using core genome multilocus sequence typing. The 78 3GC-R Escherichia coli originated from poultry (n = 27), swine (n = 26), and cattle (n = 25). Almost all (n = 77; 98.7%) harbored at least one blaESBL or blaAmpC, with blaCTX-M-1 predominating. We identified 51 STs, with ST10 and ST101 being the most frequent. The population of 3GC-R E. coli was polyclonal. The 29 3GC-R Salmonella spp. were mostly retrieved from healthy broiler (96.5%). blaCMY-2 dominated in this population. We found two clusters of CMY-2-producing Salmonella spp. in Germany: one with 15 isolates of S. Heidelberg isolates and another with six S. Minnesota, all of them with blaCMY-2. Our results confirm the low prevalence of 3GC-R E. coli and Salmonella spp. in HA and DA. blaCTX-M-1 was dominating in a highly diverse population of E. coli. 3GC-R E.coli isolated from HA and DA were genetically unrelated, with high clonal diversity suggesting multiple origins of contamination. This contrasted with the clonal population of 3GC-R Salmonella spp. in which blaCMY-2 dominated through two dominant serovars in this collection.

Susceptibility trends of swine respiratory pathogens from 2019 to 2022 to antimicrobials commonly used in Spain

BACKGROUND

Antimicrobial resistance is one of the most important health challenges in humans and animals. Antibiotic susceptibility determination is used to select the most suitable drug to treat animals according to its success probability following the European legislation in force for these drugs. We have studied the antibiotic susceptibility pattern (ASP) of Actinobacillus pleuropneumoniae (APP) and Pasteurella multocida (PM) isolates, collected during the period 2019-2022 in Spain. ASP was measured by determining minimum inhibitory concentration using standardized laboratory methods and its temporal trend was determined by logistic regression analysis of non-susceptible/susceptible isolates using clinical breakpoints.

RESULTS

It was not observed any significant temporal trends for susceptibility of Actinobacillus pleuropneumoniae to ceftiofur, florfenicol, sulfamethoxazole/trimethoprim, tulathromycin and tildipirosin during the study period (p > 0.05). Contrarily, a significant temporal trend (p < 0.05) was observed for quinolones (enrofloxacin and marbofloxacin), tetracyclines (doxycycline and oxyteracycline), amoxicillin, tiamulin and tilmicosin. On the other hand, it was not observed any significant temporal trends for susceptibility of Pasteurella multocida to quinolones (enrofloxacin and marbofloxacin), amoxicillin, ceftiofur, florfenicol and macrolides (tildipirosin, tulathromycin and tilmicosin) during the study period (p > 0.05). Contrarily, a significant temporal trend (p < 0.05) was observed for tetracyclines (oxyteracycline), tiamulin and sulfamethoxazole/trimethoprim.

CONCLUSIONS

In general terms, pig pathogens (APP and PM) involved in respiratory diseases analysed herein appeared to remain susceptible or tended to increase susceptibility to antimicrobials over the study period (2019-2022), but our data clearly showed a different pattern in the evolution of antimicrobial susceptibility for each combination of drug and microorganism. Our results highlight that the evolution of antimicrobial susceptibility must be studied in a case-by-case situation where generalization for drug families and bacteria is not possible even for bacteria located in the same ecological niche.

Knowledge and practice of antimicrobial usage and resistance among poultry farmers: A systematic review, meta-analysis, and meta-regression

A systematic review was conducted to summarize and synthesize the existing research on poultry farmers' knowledge, practices, and awareness regarding antimicrobial use (AMU) and antimicrobial resistance (AMR). It was undertaken by systematically searching databases, screening and characterizing relevant studies, extracting data, and evaluating the risk of bias. The outcomes were stratified into several subgroups, and pooled prevalence of each subgroup was calculated using a random-effect meta-analysis. Meta-regression was used for selected outcomes to further investigate the potential sources of heterogeneity across studies. Poultry farmers had knowledge and practice gaps on antimicrobial use. While most (65%; 95% CI: 50%-80%) used antimicrobials on poultry for therapeutic purposes, a portion used them to prevent disease (45%; 95% CI: 34%-55%) or boost growth (29%; 95% CI: 13%-46%) and productivity (20%; 95% CI: 6%-34%). 60% (95% CI: 50%-69%) of farmers approached veterinarians for antimicrobial advice, although many consulted drug sellers and fellow farmers. Insufficient antimicrobial residue knowledge (45%; 95% CI: 29%-62%), as well as inadequate awareness and faulty practice on withdrawal periods, were identified. Only 43% (95% CI: 34%-53%) were knowledgeable about AMR. Around half of farmers understood AMR's impacts on poultry, human health, and the environment. Meta-regression demonstrated that the source of heterogeneity for therapeutic antimicrobial use was the type of poultry farmers sampled and their educational qualifications; geographical region was significantly associated with antimicrobial usage based on farmers' experience; and the country's economic state was correlated with farmers' understanding of antimicrobial residue. This study recommends implementing legislation for judicious antimicrobial use, and farmer awareness campaigns to reinforce knowledge about prudent AMU and AMR.

Antimicrobial Resistance in Escherichia coli and Its Correlation with Antimicrobial Use on Commercial Poultry Farms in Bangladesh

Antimicrobial resistance is a global concern, posing risks to human and animal health. This research quantified antimicrobial resistance (AMR) in E. coli isolates from poultry fecal and environmental samples in Bangladesh and explored their association with antimicrobial use (AMU). We screened 725 fecal and 250 environmental samples from 94 conventional broilers and 51 Sonali farms for E. coli presence using MALDI-TOF mass spectrometry. AMU data were collected at flock levels, expressed as treatment incidence (TI), while minimum inhibitory concentrations (MIC) for 14 antibiotics were determined on five fecal E. coli isolates per farm and on all environmental isolates. MIC results were interpreted using human clinical breakpoints and EUCAST epidemiological cut-off values (ECOFFs). Acquired resistance against commonly used antimicrobial agents such as ciprofloxacin, tetracycline and ampicillin, was extremely high and predominantly clinically relevant. There was a moderate correlation between fecal and environmental antibiotic resistance index (ARI), but there was no significant correlation between AMU and AMR, suggesting that the observed AMR prevalence is unrelated to current AMU in poultry, but may be due to high historical AMU. A high level of multidrug resistance, including against critically important antimicrobials, was found in both farm types. Therefore, an AMR/AMU surveillance program is urgently needed in the poultry production sector of Bangladesh.

Animal sources of antimicrobial-resistant bacterial infections in humans: a systematic review

Bacterial antimicrobial resistance (AMR) is among the leading global health challenges of the century. Animals and their products are known contributors to the human AMR burden, but the extent of this contribution is not clear. This systematic literature review aimed to identify studies investigating the direct impact of animal sources, defined as livestock, aquaculture, pets, and animal-based food, on human AMR. We searched four scientific databases and identified 31 relevant publications, including 12 risk assessments, 16 source attribution studies, and three other studies. Most studies were published between 2012 and 2022, and most came from Europe and North America, but we also identified five articles from South and South-East Asia. The studies differed in their methodologies, conceptual approaches (bottom-up, top-down, and complex), definitions of the AMR hazard and outcome, the number and type of sources they addressed, and the outcome measures they reported. The most frequently addressed animal source was chicken, followed by cattle and pigs. Most studies investigated bacteria-resistance combinations. Overall, studies on the direct contribution of animal sources of AMR are rare but increasing. More recent publications tailor their methodologies increasingly towards the AMR hazard as a whole, providing grounds for future research to build on.

Risk Factors for Community Colonization With Extended-Spectrum Cephalosporin-Resistant Enterobacterales (ESCrE) in Botswana: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study

BACKGROUND

The epidemiology of extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) in low- and middle-income countries (LMICs) is poorly described. Identifying risk factors for ESCrE colonization is critical to inform antibiotic resistance reduction strategies because colonization is typically a precursor to infection.

METHODS

From 15 January 2020 to 4 September 2020, we surveyed a random sample of clinic patients at 6 sites in Botswana. We also invited each enrolled participant to refer up to 3 adults and children. All participants had rectal swabs collected that were inoculated onto chromogenic media followed by confirmatory testing. Data were collected on demographics, comorbidities, antibiotic use, healthcare exposures, travel, and farm and animal contact. Participants with ESCrE colonization (cases) were compared with noncolonized participants (controls) to identify risk factors for ESCrE colonization using bivariable, stratified, and multivariable analyses.

RESULTS

A total of 2000 participants were enrolled. There were 959 (48.0%) clinic participants, 477 (23.9%) adult community participants, and 564 (28.2%) child community participants. The median (interquartile range) age was 30 (12-41) and 1463 (73%) were women. There were 555 cases and 1445 controls (ie, 27.8% of participants were ESCrE colonized). Independent risk factors (adjusted odds ratio [95% confidence interval]) for ESCrE included healthcare exposure (1.37 [1.08-1.73]), foreign travel [1.98 (1.04-3.77]), tending livestock (1.34 [1.03-1.73]), and presence of an ESCrE-colonized household member (1.57 [1.08-2.27]).

CONCLUSIONS

Our results suggest healthcare exposure may be important in driving ESCrE. The strong links to livestock exposure and household member ESCrE colonization highlight the potential role of common exposure or household transmission. These findings are critical to inform strategies to curb further emergence of ESCrE in LMICs.

The effect of antibiotic usage on resistance in humans and food-producing animals: a longitudinal, One Health analysis using European data

This paper estimates the effect of antibiotic usage in humans and food-producing animals on the prevalence of resistance in zoonotic bacteria in both humans and animals. Using comprehensive longitudinal data from annual surveillance reports on resistance and usage in Europe, we find that antibiotic usage in food-producing animals and antibiotic usage in humans are independently and causally related to the prevalence of resistance in both humans and animals. The study considers simultaneous and total usage of antibiotics in humans and food-producing animals to identify the marginal effects and joint effects of usage on resistance of both groups. By employing lagged-dependent variable and fixed-effects specifications, we provide a lower and an upper bound on the effects on resistance. The paper also contributes to the scant literature on how antibiotic use in humans is related to resistance in other animals.

Zoonotic sources and the spread of antimicrobial resistance from the perspective of low and middle-income countries

BACKGROUND

Antimicrobial resistance is an increasing challenge in low and middle-income countries as it is widespread in these countries and is linked to an increased mortality. Apart from human and environmental factors, animal-related drivers of antimicrobial resistance in low- and middle-income countries have special features that differ from high-income countries. The aim of this narrative review is to address the zoonotic sources and the spread of antimicrobial resistance from the perspective of low- and middle-income countries.

MAIN BODY

Contamination with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is highest in poultry (Africa: 8.9-60%, Asia: 53-93%) and there is a risk to import ESBL-producing E. coli through poultry meat in Africa. In aquacultures, the proportion of ESBL-producers among E. coli can be high (27%) but the overall low quality of published studies limit the general conclusion on the impact of aquacultures on human health. ESBL-producing E. coli colonization of wildlife is 1-9% in bats or 2.5-63% birds. Since most of them are migratory animals, they can disperse antimicrobial resistant bacteria over large distances. So-called 'filth flies' are a relevant vector not only of enteric pathogens but also of antimicrobial resistant bacteria in settings where sanitary systems are poor. In Africa, up to 72.5% of 'filth flies' are colonized with ESBL-producing E. coli, mostly conferred by CTX-M (24.4-100%). While methicillin-resistant Staphylococcus aureus plays a minor role in livestock in Africa, it is frequently found in South America in poultry (27%) or pork (37.5-56.5%) but less common in Asia (poultry: 3%, pork: 1-16%).

CONCLUSIONS

Interventions to contain the spread of AMR should be tailored to the needs of low- and middle-income countries. These comprise capacity building of diagnostic facilities, surveillance, infection prevention and control in small-scale farming.

Effect of Group Housing of Preweaned Dairy Calves: Health and Fecal Commensal Antimicrobial Resistance Outcomes

The objectives of this study were to investigate the effects of group housing (three calves per group) on bovine respiratory disease (BRD), diarrhea and antimicrobial resistance (AMR) to fecal commensal Escherichia coli (EC) and enterococci/streptococci (ES). Our study comprised two arms, one experimental and one observational. In the experimental arm, preweaned calves on a California dairy were randomized to either individual (IND; n = 21) or group (GRP; n = 21) housing, using a modified California-style wooden hutch. The study period lasted from birth to 56 days of age, during which calves were health scored daily. Cumulative incidence and hazard ratios were estimated for disease. Antimicrobial resistance outcomes were assessed using a prospective cohort design; feces were collected from each calf three times per week and EC and ES were evaluated for AMR using the broth microdilution method against a panel of 19 antimicrobial drugs (AMD). Analysis of treatment records was used to select calves that had been exposed (EXP) to an AMD-treated calf. In GRP, exposure occurred when a calf was a hutchmate with an AMD-treated calf. In IND, exposure occurred when a calf was a neighbor with an AMD-treated calf (TRT). Age-matched unexposed calves (UNEXP) were then selected for comparison. Proportions of AMR in fecal commensals among EXP, UNEXP, and TRT calves were compared between GRP and IND. Accelerated failure time survival regression models were specified to compare differences in minimum inhibitory concentration (MIC) of fecal commensals between EXP and UNEXP calves within each of GRP and IND calves separately. Group calves had a BRD hazard 1.94 times greater that of IND calves (p = 0.03), using BRD treatment records as the outcome. For AMR in EC isolates, higher resistance to enrofloxacin was detected in enrofloxacin-EXP GRP isolates compared with enrofloxacin-EXP IND isolates, and UNEXP GRP calves had lower resistance to ceftiofur compared with enrofloxacin-EXP and enrofloxacin-TRT calves. A significant housing-by-time interaction was detected for EC ceftiofur MIC in EXP GRP calves at 4-14 days post exposure to enrofloxacin (MIC EXP-UNEXP: µg/mL (95% CI): 10.62 (1.17, 20.07)), compared with UNEXP calves. The findings of this study show an increase in BRD hazard for group-housed calves and an increase in ceftiofur resistance in group-housed calves exposed to an enrofloxacin-treated calf.

Molecular characterization and antibiotic resistance profile of ESBL-producing Escherichia coli isolated from healthy cow raw milk in smallholder dairy farms in Bangladesh

Background and Aim

The emergence of antimicrobial-resistant bacteria, such as Escherichia coli in milk, is a serious public health concern as milk is considered a complete food and an important part of daily human diet worldwide, including in Bangladesh. However, there have been no reports on the molecular characterization and antibiotic resistance profile of extended-spectrum beta-lactamase (ESBL)-producing E. coli from milk of healthy cows in Bangladesh. Therefore, this study aimed to detect and characterize ESBL-producing E. coli (ESBL-Ec) in milk samples from healthy cows in smallholder dairy farms in Mymensingh district, Bangladesh, and assess the potential risk of consuming this milk.

Materials and Methods

A total of 100 milk samples were collected from apparently healthy cows on smallholder dairy farms. Escherichia coli was isolated from the collected samples using standard methods. The detection of ESBL-Ec was performed phenotypically using cultural methods and genotypically by ESBL genetic determinants using multiplex polymerase chain reaction. Antimicrobial susceptibility testing of the ESBL-Ec isolates was performed using the disk diffusion method with 15 common antimicrobials.

Results

In this study, out of the 100 samples tested, 70 (70%) were found to be positive for E. coli. Among these, 41 (58.6%) strains were identified as ESBL-producing, both phenotypically and genotypically, with the presence of blaCTX-M, blaTEM, and blaSHV individually or combined (blaCTX-M plus blaTEM plus blaSHV). The antibiogram of these ESBL-positive isolates revealed high resistance against commonly used antibiotics, such as ampicillin, cefotaxime, and gentamicin (100%), azithromycin (88%), oxytetracycline (27%), nalidixic acid, cotrimoxazole/trimethoprim (24%), and streptomycin (22%). In addition, one isolate showed resistance to 4th generation of cephalosporin (cefepime). Most importantly, extensive multidrug resistance was found in many ESBL-Ec isolates. However, the isolates were highly sensitive to drugs such as ceftriaxone (100%) and imipenem (100%). This is the first study to detect ESBL-Ec in raw milk from healthy cows on smallholder dairy farms in Bangladesh.

Conclusion

More than 58% of the E. coli isolated from raw milk of healthy cows tested positive for ESBL production and showed resistance to most commonly used antimicrobials which may be alarming for human health. A limitation of our study is that we had a small size of sample collected from one district in Bangladesh. Therefore, a larger sample size covering a wider geographic area, and using multi-locus sequence typing and whole genome sequencing could provide a more comprehensive understanding of the prevalence and characteristics of ESBL-Ec in Bangladesh.

Antimicrobial Susceptibility of Commensal E. coli Isolated from Wild Birds in Umbria (Central Italy)

The role of wildlife, including birds, in antimicrobial resistance is nowadays a speculative topic for the scientific community as they could be spreaders/sources of antimicrobial resistance genes. In this respect, we aimed to investigate the antimicrobial susceptibility of 100 commensal Escherichia coli strains, isolated from wild birds from an Umbrian rescue centre and admitted to the Veterinary Teaching Hospital of Perugia (Central Italy) mainly for traumatic injuries. The possible presence of Salmonella spp. and ESBL-producing E. coli was also estimated. The highest prevalence of resistance was observed for ampicillin (85%) and amoxicillin/clavulanic acid (47%), probably due to their extensive use in human and veterinary medicine. Seventeen out of the one hundred E. coli isolates (17%) displayed a multidrug-resistance profile, including the beta-lactam category, with the most common resistance patterns to three or four classes of antibiotics. Resistance to ciprofloxacin, cefotaxime and ceftazidime exhibited values of 18%, 17% and 15%, respectively. Eight out of the hundred E. coli isolates (8%) were ESBL and seven showed multidrug resistance profiles. Salmonella spp. was not isolated. Resistance to third-generation cephalosporins, also detected in long-distance migratory birds, suggests the need for monitoring studies to define the role of wild birds in antimicrobial resistance circuits.

The use of aminopenicillins in animals within the EU, emergence of resistance in bacteria of animal and human origin and its possible impact on animal and human health

Aminopenicillins have been widely used for decades for the treatment of various infections in animals and humans in European countries. Following this extensive use, acquired resistance has emerged among human and animal pathogens and commensal bacteria. Aminopenicillins are important first-line treatment options in both humans and animals, but are also among limited therapies for infections with enterococci and Listeria spp. in humans in some settings. Therefore, there is a need to assess the impact of the use of these antimicrobials in animals on public and animal health. The most important mechanisms of resistance to aminopenicillins are the β-lactamase enzymes. Similar resistance genes have been detected in bacteria of human and animal origin, and molecular studies suggest that transmission of resistant bacteria or resistance genes occurs between animals and humans. Due to the complexity of epidemiology and the near ubiquity of many aminopenicillin resistance determinants, the direction of transfer is difficult to ascertain, except for major zoonotic pathogens. It is therefore challenging to estimate to what extent the use of aminopenicillins in animals could create negative health consequences to humans at the population level. Based on the extent of use of aminopenicillins in humans, it seems probable that the major resistance selection pressure in human pathogens in European countries is due to human consumption. It is evident that veterinary use of these antimicrobials increases the selection pressure towards resistance in animals and loss of efficacy will at minimum jeopardize animal health and welfare.

Impact of California's Senate Bill 27 on Antimicrobial-Resistant Escherichia coli Urinary Tract Infection in Humans: Protocol for a Study of Methods and Baseline Data

BACKGROUND

Overuse of antibiotics contributes to antimicrobial resistance (AMR) and is a growing threat to human health worldwide. Previous work suggests a link between antimicrobial use in poultry and human AMR extraintestinal pathogenic Escherichia coli (E coli) urinary tract infections (UTIs). However, few US-based studies exist, and none have comprehensively assessed both foodborne and environmental pathways using advanced molecular and spatial epidemiologic methods in a quasi-experimental design. Recently, California enacted Senate Bill 27 (SB27), which changed previous policy to require a veterinarian's prescription for the use of antibiotic drugs, and which banned antibiotic use for disease prevention in livestock. This provided an opportunity to evaluate whether SB27 will result in a reduction in antimicrobial-resistant infections in humans.

OBJECTIVE

We describe in detail the methods implemented to achieve the overarching objective of this study to evaluate the impact of SB27 on downstream antibiotic resistance rates in human UTIs.

METHODS

A summary of the overall approach and the partnerships between Columbia University, George Washington University (GWU), Johns Hopkins Bloomberg School of Public Health, Kaiser Permanente Southern California (KPSC) Research and Evaluation, the Natural Resources Defense Council, Sanger Institute at Stanford University, Sutter Health Center for Health Systems Research, the University of Cambridge, and the University of Oxford is presented. The collection, quality control testing, and shipment of retail meat and clinical samples are described. Retail meat (chicken, beef, turkey, and pork) was purchased from stores throughout Southern California from 2017 to 2021. After processing at KPSC, it was shipped to GWU for testing. From 2016 to 2021, after clinical specimens were processed for routine clinical purposes and immediately before discarding, those with isolated colonies of E coli, Campylobacter, and Salmonella from KPSC members were collected and processed to be shipped for testing at GWU. Detailed methods of the isolation and testing as well as the whole-genome sequencing of the meat and clinical samples at GWU are described. KPSC electronic health record data were used to track UTI cases and AMR patterns among the cultured specimens. Similarly, Sutter Health electronic health record data were used to track UTI cases in its Northern California patient population.

RESULTS

From 2017 to 2021, overall, 12,616 retail meat samples were purchased from 472 unique stores across Southern California. In addition, 31,643 positive clinical cultures were collected from KPSC members during the same study period.

CONCLUSIONS

Here, we presented data collection methods for the study, which was conducted to evaluate the impact of SB27 on downstream antibiotic resistance rates in human UTI. To date, it is one of the largest studies of its kind to be conducted. The data collected during this study will be used as the foundation for future analyses specific to the various objectives of this large body of work.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/45109.

Global antimicrobial-resistance drivers: an ecological country-level study at the human-animal interface

BACKGROUND

Antimicrobial resistance (AMR) is a pressing, holistic, and multisectoral challenge facing contemporary global health. In this study we assessed the associations between socioeconomic, anthropogenic, and environmental indicators and country-level rates of AMR in humans and food-producing animals.

METHODS

In this modelling study, we obtained data on Carbapenem-resistant Acinetobacter baumanii and Pseudomonas aeruginosa, third generation cephalosporins-resistant Escherichia coli and Klebsiella pneumoniae, oxacillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium AMR in humans and food-producing animals from publicly available sources, including WHO, World Bank, and Center for Disease Dynamics Economics and Policy. AMR in food-producing animals presented a combined prevalence of AMR exposure in cattle, pigs, and chickens. We used multivariable β regression models to determine the adjusted association between human and food-producing animal AMR rates and an array of ecological country-level indicators. Human AMR rates were classified according to the WHO priority pathogens list and antibiotic-bacterium pairs.

FINDINGS

Significant associations were identified between animal antimicrobial consumption and AMR in food-producing animals (OR 1·05 [95% CI 1·01-1·10]; p=0·013), and between human antimicrobial consumption and AMR specifically in WHO critical priority (1·06 [1·00-1·12]; p=0·035) and high priority (1·22 [1·09-1·37]; p<0·0001) pathogens. Bidirectional associations were also found: animal antibiotic consumption was positively linked with resistance in critical priority human pathogens (1·07 [1·01-1·13]; p=0·020) and human antibiotic consumption was positively linked with animal AMR (1·05 [1·01-1·09]; p=0·010). Carbapenem-resistant Acinetobacter baumanii, third generation cephalosporins-resistant Escherichia coli, and oxacillin-resistant Staphylococcus aureus all had significant associations with animal antibiotic consumption. Analyses also suggested significant roles of socioeconomics, including governance on AMR rates in humans and animals.

INTERPRETATION

Reduced rates of antibiotic consumption alone will not be sufficient to combat the rising worldwide prevalence of AMR. Control methods should focus on poverty reduction and aim to prevent AMR transmission across different One Health domains while accounting for domain-specific risk factors. The levelling up of livestock surveillance systems to better match those reporting on human AMR, and, strengthening all surveillance efforts, particularly in low-income and middle-income countries, are pressing priorities.

FUNDING

None.

Bacterial genome sequencing tracks the housefly-associated dispersal of fluoroquinolone- and cephalosporin-resistant Escherichia coli from a pig farm

The regular use of antimicrobials in livestock production selects for antimicrobial resistance. The potential impact of this practice on human health needs to be studied in more detail, including the role of the environment for the persistence and transmission of antimicrobial-resistant bacteria. During an investigation of a pig farm and its surroundings in Brandenburg, Germany, we detected abundant cephalosporin- and fluoroquinolone-resistant Escherichia coli in pig faeces, sedimented dust, and house flies (Musca domestica). Genome sequencing of E. coli isolates revealed large phylogenetic diversity and plasmid-borne extended-spectrum beta lactamase (ESBL) genes CTX-M-1 in multiple strains. [Correction added on 28 February 2023, after first online publication: In the preceding sentence, 'and TEM-1' was previously included but has been deleted in this version.] Close genomic relationships indicated frequent transmission of antimicrobial-resistant E. coli between pigs from different herds and across buildings of the farm and suggested dust and flies as vectors for dissemination of faecal pathogens. Strikingly, we repeatedly recovered E. coli from flies collected up to 2 km away from the source, whose genome sequences were identical or closely related to those from pig faeces isolates, indicating the fly-associated transport of diverse ESBL-producing E. coli from the pig farm into urban habitation areas. The observed proximity of contaminated flies to human households poses a risk of transmission of antimicrobial-resistant enteric pathogens from livestock to man.

Prevalence, Characterization, and Antimicrobial Resistance of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli from Domestic Free-Range Poultry in Agogo, Ghana

Poultry has been suggested as an important source for extended-spectrum beta-lactamase (ESBL)-producing bacteria that can lead to difficult-to treat infections in humans. Therefore, this study aims to determine the frequency, the genetics, and antimicrobial resistance profiles of ESBL-producing Escherichia coli in domestic free-range poultry in Agogo, Ghana. The study was set up and piloted from January 2019 until June 2019. Between June and December 2019, fecal samples (N = 144) were collected from free-roaming chickens from domestic farms in the regions of Sukuumu, Bontodiase, and Freetown and cultured on ESBL screening agar. Strain identification and antibiotic susceptibility were performed using the VITEK 2 compact system. ESBL-producing E. coli were confirmed using the double disk synergy test. Molecular characterization of ESBL-associated genes (bla_TEM, bla_SHV, and bla_CTX-M) were performed using conventional polymerase chain reaction (PCR) and further sequencing of obtained PCR amplicons. The result showed that 56.2% (n/N = 81/144) of collected fecal samples were positive for ESBL-producing E. coli. Majority of the isolates showed resistance to tetracycline (93.8%, n/N = 76/81) and trimethoprim-sulfamethoxazole (66.7, n/N = 54/81), whereas resistance to carbapenems was not found. The majority of ESBL-producing E. coli carried the bla_CTX-M genes, with bla_CTX-M-15 being the dominant (95.1%, n/N = 77/81) genotype. In this study, we report high frequencies of ESBL-producing E. coli in smallholder free-range poultry representing a potential source of infection, highlighting the need for control of antibiotic use and animal hygiene/sanitation measures, both important from a One Health perspective.

Biofilm Formation Ability of ESBL/pAmpC-Producing Escherichia coli Isolated from the Broiler Production Pyramid

Escherichia coli able to produce extended spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (pAmpCs) represents a serious threat to public health, since these genes confer resistance to critically important antimicrobials (i.e., third generation cephalosporins) and can be transferred to non-resistant bacteria via plasmids. E. coli are known to be able to form a biofilm, which represents a favorable environment for the exchange of resistance determinants. Here, we assessed the ability of 102 ESBL/pAmpC-producing E. coli isolated from the broiler production pyramid to form a biofilm and to identify genetic factors involved in biofilm formation. All but one of the ESBL/pAmpC-producing E. coli were able to form a biofilm, and this represents a great concern to public health. E. coli belonging to phylogroups D, E, and F, as well as strains harboring the blaCTX-M-type gene, seem to be associated with an increased biofilm capability (p < 0.05). Furthermore, virulence genes involved in adherence and invasion (i.e., csgBAC, csgDEFG, matABCDEF, and sfaX) seem to enhance biofilm formation in E. coli. Efforts should be made to reduce the presence of ESBL/pAmpC- and biofilm-producing E. coli in the broiler production pyramid and, therefore, the risk of dissemination of resistant bacteria and genes.

Molecular detection and antimicrobial resistance profiles of Extended-Spectrum Beta-Lactamase (ESBL) producing Escherichia coli in broiler chicken farms in Malaysia

Antimicrobial resistance is one of the major public health threats globally. This challenge has been aggravated with the overuse and misuse of antibiotics in food animals and humans. The present study aimed to investigate the prevalence of Extended-Spectrum β-lactamase (ESBL) genes in Escherichia coli (E. coli) isolated from broiler chickens in Kelantan, Malaysia. A total of 320 cloacal swabs were collected from farms in different districts of Kelantan and were analyzed using routine bacteriology, antimicrobial susceptibility test, and molecular techniques for further identification and characterization of ESBL encoding genes. Based on PCR detection for the E. coli species-specific Pho gene, 30.3% (97/320) of isolates were confirmed as E. coli, and 84.5% (82/97) of the isolates were positive for at least one ESBL gene. Majority of the isolates, 62.9% (61/97) were harboring blaCTX-M followed by 45.4% (44/97) of blaTEM genes, while 16.5% (16/97) of the isolates were positive for both mcr-1 and ESBL genes. Overall, 93.8% (90/97) of the E. coli were resistant to three or more antimicrobials; indicating that the isolates were multi-drug resistance. 90.7% of multiple antibiotic resistance (MAR) index value greater than 0.2, would also suggest the isolates were from high-risk sources of contamination. The MLST result shows that the isolates are widely diverse. Our findings provide insight into the alarmingly high distribution of antimicrobial resistant bacteria, mainly ESBL producing E. coli in apparently healthy chickens indicating the role of food animals in the emergence and spread of antimicrobial resistance, and the potential public health threats it may pose.

European-wide antimicrobial resistance monitoring in commensal Escherichia coli isolated from healthy food animals between 2004 and 2018

OBJECTIVES

To describe the susceptibility of Escherichia coli to medically important antibiotics, collected over four periods (2004-2006, 2008-2009, 2013-2014, 2017-2018), from food-producing animals at slaughter.

METHODS

Intestinal contents from cattle, pigs and broilers were randomly sampled (5-6 countries/host; ≥4 abattoirs/country; one sample/animal/farm) for isolation of Escherichia coli; antimicrobial susceptibilities were centrally determined by CLSI agar dilution. Clinical breakpoints (CLSI) and epidemiological cut-off values (EUCAST) were applied for data interpretation.

RESULTS

In total, 10 613 E. coli strains were recovered. In broilers, resistance percentages were the lowest (P ≤ 0.01) in the latest time period. A significant decrease in MDR over time was also observed for broilers and a tendency for a decrease for pigs. Resistance to meropenem and tigecycline was absent, and resistance to azithromycin was 0.2%-2.0%. Also, low resistance to third-generation cephalosporins (1.1%-7.4%) was detected in broilers. Resistance to colistin varied between 0.1%-4.8%. E. coli from broilers showed high resistance to ciprofloxacin (7.3%-23.3%), whereas for cattle and pigs this was 0.2%-2.5%. Low/moderate resistance to chloramphenicol (9.3%-21.3%) and gentamicin (0.9%-7.0%) was observed in pigs and broilers. The highest resistance was noted for ampicillin (32.7%-65.3%), tetracycline (41.3%-67.5%), trimethoprim (32.0%-35.7%) and trimethoprim/sulfamethoxazole (27.5%-49.7%) from pigs and broilers, with marked country differences. MDR peaked in pigs and broilers with 24 and 26 phenotypes, with 21.9%-26.2% and 18.7%-34.1% resistance, respectively.

CONCLUSIONS

In this pan-EU survey antibiotic susceptibility of commensal E. coli varied largely between antibiotics, animal species and countries. Resistance to critically important antibiotics for human medicine was absent or low, except for ciprofloxacin in broilers and ampicillin in pigs and broilers.

An Overview of Macrolide Resistance in Streptococci: Prevalence, Mobile Elements and Dynamics

Streptococcal infections are usually treated with beta-lactam antibiotics, but, in case of allergic patients or reduced antibiotic susceptibility, macrolides and fluoroquinolones are the main alternatives. This work focuses on studying macrolide resistance rates, genetic associated determinants and antibiotic consumption data in Spain, Europe and also on a global scale. Macrolide resistance (MR) determinants, such as ribosomal methylases (erm(B), erm(TR), erm(T)) or active antibiotic efflux pumps and ribosomal protectors (mef(A/E)-mrs(D)), are differently distributed worldwide and associated with different clonal lineages and mobile genetic elements. MR rates vary together depending on clonal dynamics and on antibiotic consumption applying selective pressure. Among Streptococcus, higher MR rates are found in the viridans group, Streptococcus pneumoniae and Streptococcus agalactiae, and lower MR rates are described in Streptococcus pyogenes. When considering different geographic areas, higher resistance rates are usually found in East-Asian countries and milder or lower in the US and Europe. Unfortunately, the availability of data varies also between countries; it is scarce in low- and middle- income countries from Africa and South America. Thus, surveillance studies of macrolide resistance rates and the resistance determinants involved should be promoted to complete global knowledge among macrolide resistance dynamics.

Human Colonization with Antibiotic-Resistant Bacteria from Nonoccupational Exposure to Domesticated Animals in Low- and Middle-Income Countries: A Critical Review

Data on community-acquired antibiotic-resistant bacterial infections are particularly sparse in low- and middle-income countries (LMICs). Limited surveillance and oversight of antibiotic use in food-producing animals, inadequate access to safe drinking water, and insufficient sanitation and hygiene infrastructure in LMICs could exacerbate the risk of zoonotic antibiotic resistance transmission. This critical review compiles evidence of zoonotic exchange of antibiotic-resistant bacteria (ARB) or antibiotic resistance genes (ARGs) within households and backyard farms in LMICs, as well as assesses transmission mechanisms, risk factors, and environmental transmission pathways. Overall, substantial evidence exists for exchange of antibiotic resistance between domesticated animals and in-contact humans. Whole bacteria transmission and horizontal gene transfer between humans and animals were demonstrated within and between households and backyard farms. Further, we identified water, soil, and animal food products as environmental transmission pathways for exchange of ARB and ARGs between animals and humans, although directionality of transmission is poorly understood. Herein we propose study designs, methods, and topical considerations for priority incorporation into future One Health research to inform effective interventions and policies to disrupt zoonotic antibiotic resistance exchange in low-income communities.

Genetic Diversity of Escherichia coli Coharboring mcr-1 and Extended Spectrum Beta-Lactamases from Poultry

Background. The emergence of resistance to beta-lactam agents in poultry results in multidrug-resistant (MDR) phenotypes in Escherichia coli isolates from poultry birds. The appearance of mobile colistin resistance (mcr) genes in the poultry sector has further worsened the situation. Therefore, the current study is aimed at investigating the molecular epidemiology of mcr harboring colistin-resistant E. coli among poultry. Methods. The isolation and identification of colistin-resistant E. coli (CR-Ec) were done from the broiler’s fecal samples through culturing using selective media supplemented with colistin sulfate (4 μg/ml). The antibiogram studies of the isolates were performed using the disc diffusion method and broth microdilution method as per CLSI guidelines. The screening for the genes conferring resistance to colistin as well as beta-lactam agents was performed by PCR. The genetic diversity of mcr-positive strains was assessed by multilocus sequencing typing (MLST). Results. Out of 500 fecal samples, 7% (35/500) were found positive for the presence of colistin-resistant E. coli (CR-Ec). Among the CR-Ec isolates, 74.28% (26/35) were detected as ESBL producers carrying the blaCTX-M-1 gene in 15/35 (42.85%) isolates and blaCTX-M-15 and blaTEM genes in 21/35 (60%) and 35/35 (100%) isolates, respectively. E. coli isolates were found positive for the presence of mcr-1, although none of the isolates exhibited the mcr-2 or mcr-3 genes. The MLST of CR-Ec has shown the ST1035 as the most prevalent genotype, while 82.85% (29/35) of CR-Ec strains belonged to clonal complex (CC) 131 comprising ST1035, ST131, ST1215, ST1650, and ST2279. Conclusions. The findings suggest a continuous monitoring system in veterinary and clinical settings to avoid unnecessary antibiotics. Further studies are needed at the national level to help control the increasing resistance among Enterobacterales in poultry settings.

Application of Plant-Derived Nanoparticles (PDNP) in Food-Producing Animals as a Bio-Control Agent against Antimicrobial-Resistant Pathogens

Antibiotics are regularly used in animal husbandry to treat diseases. This practice is beneficial to animals' health and helps ensure food security. However, the misuse of antibiotics, especially in food-producing animals, has resulted in the advent of antimicrobial resistance (AMR) and its dissemination among foodborne pathogens. The occurrence of AMR in bacteria pathogens that cause infections in animals and those associated with food spoilage is now considered a global health concern affecting humans, animals and the environment. The search for alternative antimicrobial agents has kindled the interest of many researchers. Among the alternatives, using plant-derived nanoparticles (PDNPs) for treating microbial dysfunctions in food-producing animals has gained significant attention. In traditional medicine, plant extracts are considered as safe, efficient and natural antibacterial agents for various animal diseases. Given the complexity of the AMR and concerns about issues at the interface of human health, animal health and the environment, it is important to emphasize the role of a One Health approach in addressing this problem. This review examines the potential of PDNPs as bio-control agents in food-producing animals, intending to provide consumers with microbiologically safe food while ensuring food safety and security, better health for animals and humans and a safe environment.

Photoreactive Coating Material as an Effective and Durable Antimicrobial Composite in Reducing Bacterial Load on Surfaces in Livestock

Titanium dioxide (TiO2) is a well-known photocatalytic compound that can be used to effectively reduce the presence of pathogens in human and animal hospitals via ROS release. The aim of this study was to investigate the efficacy of a polymer-based composite layer containing TiO2 and zinc oxide (ZnO) against Escherichia coli (E. coli) of animal origin. We showed that the photocatalyst coating caused a significant (p < 0.001) reduction in pathogen numbers compared to the control with an average reduction of 94% over 30 min. We used six light sources of different wattages (4 W, 7 W, 9 W, 12 W, 18 W, 36 W) at six distances (35 cm, 100 cm, 150 cm, 200 cm, 250 cm, 300 cm). Samples (n = 2160) were taken in the 36 settings and showed no significant difference in efficacy between light intensity and distance. We also investigated the influence of organic contaminant that resulted in lower activity as well as the effect of a water jet and a high-pressure device on the antibacterial activity. We found that the latter completely removed the coating from the surface, which significantly (p < 0.0001) reduced its antibacterial potential. As a conclusion, light intensity and distance does not reduce the efficacy of the polymer, but the presence of organic contaminants does.

Current Insights Regarding the Role of Farm Animals in the Spread of Antimicrobial Resistance from a One Health Perspective

Antimicrobial resistance (AMR) represents a global threat to both human and animal health and has received increasing attention over the years from different stakeholders. Certain AMR bacteria circulate between humans, animals, and the environment, while AMR genes can be found in all ecosystems. The aim of the present review was to provide an overview of antimicrobial use in food-producing animals and to document the current status of the role of farm animals in the spread of AMR to humans. The available body of scientific evidence supported the notion that restricted use of antimicrobials in farm animals was effective in reducing AMR in livestock and, in some cases, in humans. However, most recent studies have reported that livestock have little contribution to the acquisition of AMR bacteria and/or AMR genes by humans. Overall, strategies applied on farms that target the reduction of all antimicrobials are recommended, as these are apparently associated with notable reduction in AMR (avoiding co-resistance between antimicrobials). The interconnection between human and animal health as well as the environment requires the acceleration of the implementation of the 'One Health' approach to effectively fight AMR while preserving the effectiveness of antimicrobials.

Emergence and spread of antibiotic-resistant foodborne pathogens from farm to table

Antibiotics have been overused and misused for preventive and therapeutic purposes. Specifically, antibiotics are frequently used as growth promoters for improving productivity and performance of food-producing animals such as pigs, cattle, and poultry. The increasing use of antibiotics has been of great concern worldwide due to the emergence of antibiotic resistant bacteria. Food-producing animals are considered reservoirs for antibiotic resistance genes (ARGs) and residual antibiotics that transfer from the farm through the table. The accumulation of residual antibiotics can lead to additional antibiotic resistance in bacteria. Therefore, this review evaluates the risk of carriage and spread of antibiotic resistance through food chain and the potential impact of antibiotic use in food-producing animals on food safety. This review also includes in-depth discussion of promising antibiotic alternatives such as vaccines, immune modulators, phytochemicals, antimicrobial peptides, probiotics, and bacteriophages.

Occurrence and transfer characteristics of blaCTX-M genes among Escherichia coli in anaerobic digestion systems treating swine waste

Livestock waste is a known reservoir of Escherichia coli (E. coli) carrying clinically important CTX-M-type extended-spectrum β-lactamase genes (bla_CTX-M), however, the occurrence and transfer characteristics of bla_CTX-M genes during anaerobic digestion (AD) remain unclear. Herein, four full-scale and two parallel lab-scale AD systems treating swine waste under ambient and mesophilic conditions were investigated by both molecular- and culture-based methods to reveal the occurrence and transfer behaviors of bla_CTX-M genes during AD. Real-time TaqMan polymerase chain reaction revealed 1.3 × 10⁴-6.8 × 10⁵ and 3.0 × 10⁴-7.0 × 10⁵ copies/mL of bla_CTX-M groups 1 and 9 in all feeding substrates. While AD reduced the absolute abundance of groups 1 and 9 by 0.63-2.24 and 0.08-1.30 log (P < 0.05), 5.0 × 10²-4.1 × 10³ and 1.1 × 10⁴-3.5 × 10⁴ copies/mL of groups 1 and 9 remained in the anaerobic effluent, respectively. In total, 141 bla_CTX-M-carrying E. coli isolates resistant to cefotaxime were obtained from the AD reactors. Whole-genome sequencing showed that bla_CTX-M-65 mainly carried by E. coli ST155 was the most frequently detected group 9 subtype in the feeding substrate; whereas bla_CTX-M-14 associated with the dominant clones E. coli ST6802 and ST155 became the major subtype in AD effluent. Furthermore, bla_CTX-M-14 was flanked by ΔIS26 upstream and ΔIS903B downstream. The ΔIS26-bla_CTX-M-14-ΔIS903B element was mainly located on the IncHI2 plasmid in E. coli ST48 and ST6802 and also the IncFIB plasmid in ST155 in anaerobic effluent. Conjugation assays showed that the plasmids harboring bla_CTX-M-14 could be successfully transferred at a frequency of 10^-3-10^-2 cells per recipient cell. This study revealed that bla_CTX-M genes remained in both the full-scale and lab-scale AD effluents of swine waste. Thus, additional efforts should be implemented to block the discharge and spread of antibiotic resistance genes to the environment.

Highly Virulent and Multidrug-Resistant Escherichia coli Sequence Type 58 from a Sausage in Germany

Studies have previously described the occurrence of multidrug-resistant (MDR) Escherichia coli in human and veterinary medical settings, livestock, and, to a lesser extent, in the environment and food. While they mostly analyzed foodborne E. coli regarding phenotypic and sometimes genotypic antibiotic resistance and basic phylogenetic classification, we have limited understanding of the in vitro and in vivo virulence characteristics and global phylogenetic contexts of these bacteria. Here, we investigated in-depth an E. coli strain (PBIO3502) isolated from a pork sausage in Germany in 2021. Whole-genome sequence analysis revealed sequence type (ST)58, which has an internationally emerging high-risk clonal lineage. In addition to its MDR phenotype that mostly matched the genotype, PBIO3502 demonstrated pronounced virulence features, including in vitro biofilm formation, siderophore secretion, serum resilience, and in vivo mortality in Galleria mellonella larvae. Along with the genomic analysis indicating close phylogenetic relatedness of our strain with publicly available, clinically relevant representatives of the same ST, these results suggest the zoonotic and pathogenic character of PBIO3502 with the potential to cause infection in humans and animals. Additionally, our study highlights the necessity of the One Health approach while integrating human, animal, and environmental health, as well as the role of meat products and food chains in the putative transmission of MDR pathogens.

Retail Chicken Carcasses as a Reservoir of Multidrug-Resistant Salmonella

Salmonella is a major cause of foodborne disease outbreaks worldwide, mainly through poultry. Recently, there has been an increase in multidrug-resistant (MDR) Salmonella infections globally. The increased drug resistance results in increased costs and poorer health outcomes due to unavailability or delayed treatment. This study aims to determine the prevalence of Salmonella in retail raw chicken meat and identify their antimicrobial resistance profiles. A total of 270 retail raw chicken carcasses (local and imported) were collected from three hypermarket chains in Qatar between November 2017 and April 2018. Thirty carcasses were contaminated with Salmonella (11.11%). The prevalence of Salmonella in locally produced chicken was higher than in imported chicken (OR = 2.56, 95% CI: 1.18-5.53, p = 0.016). No significant differences were found between the prevalence and storage temperature or hypermarket chain. The highest resistance rates in the isolates were reported to tetracycline (73.7%) followed by nitrofurantoin (53.3%), ampicillin (50%), amoxicillin-clavulanic acid, ceftriaxone (26.7%), and ciprofloxacin (23.3%). Eight isolates were potential extended-spectrum β-lactamase-producers, all in imported frozen chicken (p < 0.0001). Additionally, 43.3% of the isolates were MDR and associated with frozen chicken (OR = 16.88, 95% CI: 2.55-111.47, p = 0.002). The findings indicate that while the prevalence of Salmonella in retail chicken in Qatar is moderate, a large proportion of them are MDR.

Genomic diversity of genus Limosilactobacillus

The genus Limosilactobacillus (formerly Lactobacillus) contains multiple species considered to be adapted to vertebrates, yet their genomic diversity has not been explored. In this study, we performed comparative genomic analysis of Limosilactobacillus (22 species; 332 genomes) isolated from different niches, further focusing on human strains (11 species; 74 genomes) and their adaptation features to specific body sites. Phylogenomic analysis of Limosilactobacillus showed misidentification of some strains deposited in public databases and existence of putative novel Limosilactobacillus species. The pangenome analysis revealed a remarkable genomic diversity (only 1.3 % of gene clusters are shared), and we did not observe a strong association of the accessory genome with different niches. The pangenome of Limosilactobacillus reuteri and Limosilactobacillus fermentum was open, suggesting that acquisition of genes is still occurring. Although most Limosilactobacillus were predicted as antibiotic susceptible (83%), acquired antibiotic-resistance genes were common in L. reuteri from food-producing animals. Genes related to lactic acid isoform production (>95 %) and putative bacteriocins (70.2%) were identified in most Limosilactobacillus strains, while prophages (55.4%) and CRISPR-Cas systems (32.0%) were less prevalent. Among strains from human sources, several metabolic pathways were predicted as conserved and completed. Their accessory genome was highly variable and did not cluster according to different human body sites, with some exceptions (urogenital Limosilactobacillus vaginalis, Limosilactobacillus portuensis, Limosilactobacillus urinaemulieris and Limosilactobacillus coleohominis or gastrointestinal Limosilactobacillus mucosae). Moreover, we identified 12 Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologues that were significantly enriched in strains from particular body sites. We concluded that evolution of the highly diverse Limosilactobacillus is complex and not always related to niche or human body site origin.

The role of Musca domestica and milk in transmitting pathogenic multidrug-resistant Escherichia coli and associated phylogroups to neonatal calves

Escherichia coli, as a global source of antimicrobial resistance, is a serious veterinary and public health concern. The transmission of pathogenic multidrug-resistant (MDR) E. coli within diarrheic calves and its correlation with Musca domestica and milk strains have been investigated. In total, 110, 80, and 26 E. coli strains were obtained from 70 rectal swabs from diarrheic calves, 60 milk samples and 20 M. domestica, respectively. Molecular pathotyping of E. coli revealed the presence of pathogenic E. coli with a higher percentage of shigatoxigenic strains within diarrheic calves and M. domestica at 46.4% and 34.6%, respectively. Phenotypic antimicrobial resistance revealed higher β-lactams resistance except for cefquinome that exhibited low resistance in M.domestica and milk strains at 30.8% and 30%, respectively. The extended-spectrum cephalosporin (ESC) resistant strains were detected within fecal, M. domestica, and milk strains at 69.1%, 73.1%, and 71.3%, respectively. All E. coli strains isolated from M. domestica exhibited MDR, while fecal and milk strains were harboring MDR at 99.1% and 85%, respectively. Molecular detection of resistant genes revealed the predominance of the bla_TEM gene, while none of these strains harbored the bla_OXA gene. The highest percentages for bla_CTXM and bla_CMYII genes were detected in M. domestica strains at 53.8% and 61.5%, respectively. Regarding colistin resistance, the mcr-1 gene was detected only in fecal and milk strains at 35.5% and 15%, respectively. A high frequency of phylogroup B2 was detected within fecal and M. domestica strains, while milk strains were mainly assigned to the B1 phylogroup. Pathogenic E. coli strains with the same phenotypic and genotypic antimicrobial resistance and phylogroups were identified for both diarrheic calves and M. domestica, suggesting that the possible role of M. domestica in disseminating pathogenic strains and antimicrobial resistance in dairy farms.

The microbial ecology of Escherichia coli in the vertebrate gut

Escherichia coli has a rich history as biology's 'rock star', driving advances across many fields. In the wild, E. coli resides innocuously in the gut of humans and animals but is also a versatile pathogen commonly associated with intestinal and extraintestinal infections and antimicrobial resistance-including large foodborne outbreaks such as the one that swept across Europe in 2011, killing 54 individuals and causing approximately 4000 infections and 900 cases of haemolytic uraemic syndrome. Given that most E. coli are harmless gut colonizers, an important ecological question plaguing microbiologists is what makes E. coli an occasionally devastating pathogen? To address this question requires an enhanced understanding of the ecology of the organism as a commensal. Here, we review how our knowledge of the ecology and within-host diversity of this organism in the vertebrate gut has progressed in the 137 years since E. coli was first described. We also review current approaches to the study of within-host bacterial diversity. In closing, we discuss some of the outstanding questions yet to be addressed and prospects for future research.

One Health Surveillance of Antimicrobial Resistance Phenotypes in Selected Communities in Thailand

Integrated surveillance of antimicrobial resistance (AMR) using the One Health approach that includes humans, animals, food, and the environment has been recommended by responsible international organizations. The objective of this study was to determine the prevalence of AMR phenotypes in Escherichia coli and Klebsiella species isolated from humans, pigs, chickens, and wild rodents in five communities in northern Thailand. Rectal swabs from 269 pigs and 318 chickens; intestinal contents of 196 wild rodents; and stool samples from 69 pig farmers, 155 chicken farmers, and 61 non-farmers were cultured for E. coli and Klebsiella species, which were then tested for resistance to ceftriaxone, colistin, and meropenem. The prevalence of ceftriaxone-resistant E. coli and Klebsiella species in pigs, chickens, rodents, pig farmers, chicken farmers, and non-farmers was 64.3%, 12.9%, 4.1%, 55.1%, 38.7%, and 36.1%, respectively. Colistin resistance in pigs, chickens, rodents, pig farmers, chicken farmers, and non-farmers was 41.3%, 9.8%, 4.6%, 34.8%, 31.6%, and 24.6%, respectively. Meropenem resistance was not detected. The observed high prevalence of AMR, especially colistin resistance, in study food animals/humans is worrisome. Further studies to identify factors that contribute to AMR, strengthened reinforcement of existing regulations on antimicrobial use, and more appropriate interventions to minimize AMR in communities are urgently needed.

Minas Artisanal Cheese As Potential Source of Multidrug-Resistant Escherichia coli

Bacteria develop resistance to antibiotics naturally, but the inappropriate and widespread use of antibiotics in humans and animals has made antimicrobial resistance one of the biggest threats to modern medicine. Raw milk cheese can represent an important source of antimicrobial resistance. Thus, the objective of this study was to evaluate the prevalence and sensitivity of Escherichia coli isolated from artisanal cheese made from raw milk produced in Minas Gerais, Brazil. E. coli counts were determined using the most probable number method. An antibiogram was performed using the disk diffusion method, following the protocol described by the Brazilian Committee on Antimicrobial Susceptibility Testing (BrCAST) for 14 antibiotics of nine classes. E. coli was detected in 35 (71.4%) of the samples, with populations between 0.56 to 4.87 log (NMP/g) of cheese. The presence of E. coli resistant to multiple antimicrobials was more frequent in cheeses, with an E. coli population below the levels established by regulatory limits. Only four samples (11.4%) had all E. coli isolates susceptible to the 14 antimicrobials evaluated. The results showed the heterogeneity of antimicrobial resistance in E. coli between the producing regions of Minas artisanal cheese. Multidrug resistance was detected in 29% of the E. coli isolates and in almost 40% (38.8%) of the cheese samples. The frequency of multidrug-resistant (MDR) isolates was different between the production regions (p < 0.05). The presence of MDR E. coli in cheese from region D was 14, 4, and 20 times more likely than in cheese from regions A, B, and C, respectively. A multiple antibiotic resistance index of 0.200 predicted the presence of MDR E. coli in raw milk artisanal cheese with 99% probability. In conclusion, artisanal cheese can act as sources of MDR E. coli to colonize the human gastrointestinal tract.

F Plasmid Lineages in Escherichia coli ST95: Implications for Host Range, Antibiotic Resistance, and Zoonoses

Escherichia coli sequence type 95 (ST95) is an extraintestinal pathogenic E. coli (ExPEC) renowned for its ability to cause significant morbidity and mortality in humans and poultry. A core genome analysis of 668 ST95 isolates generated 10 clades (A to J), 5 of which are reported here for the first time. F plasmid replicon sequence typing showed that almost a third (178/668 [27%]) of the collection carry pUTI89 (F29:B10) and were restricted to clade A and a sublineage of clade B. In contrast, almost half (328/668 [49%]) of the collection across multiple clades harbor ColV plasmids (multiple F types). Strikingly, ST95 lineages with pUTI89 were almost exclusively from humans, while ColV⁺ ST95 lineages were sourced from poultry and humans. Clade I was notable because it comprises temporally and geographically matched ColV⁺ isolates sourced from human and retail poultry meat, suggesting interspecies transmission via food. Clade F contained ST95 isolates of bovine origin, none of which carried ColV or pUTI89 plasmids. Remarkably, an analysis of a cohort of 34,176 E. coli isolates comprising 2,570 sequence types mirrored what was observed in ST95: (i) pUTI89 was overwhelmingly linked to E. coli sourced from humans but almost entirely absent from 13,027 E. coli isolates recovered from poultry, pigs, and cattle, and (ii) E. coli isolates harboring ColV plasmids were from multiple sources, including humans, poultry, and swine. Overall, our data suggest that F plasmids influence E. coli host range, clade structure, and zoonotic potential in ST95 and ExPEC more broadly.

IMPORTANCEE. coli ST95 is one of five dominant ExPEC lineages globally and noted for causing urinary tract and bloodstream infections and neonatal meningitis in humans and colibacillosis in poultry. Using high-resolution phylogenomics, we show that F replicon sequence type is linked to ST95 clade structure and zoonotic potential. Specifically, human centric ST95 clades overwhelmingly harbor F29:B10 (pUTI89) plasmids, while clades carrying both human- and poultry-sourced isolates are typically ColV⁺ with multiple replicon types. Importantly, several clades identified clonal ColV⁺ ST95 isolates from human and poultry sources, but clade I, which housed temporally and spatially matched isolates, provided the most robust evidence. Notably, patterns of association of F replicon types with E. coli host were mirrored within a diverse collection of 34,176 E. coli genomes. Our studies indicate that the role of food animals as a source of human ExPEC disease is complex and warrants further investigation.

Molecular Detection of Colistin Resistance mcr-1 Gene in Multidrug-Resistant Escherichia coli Isolated from Chicken

Zoonotic and antimicrobial-resistant Escherichia coli (hereafter, E. coli) is a global public health threat which can lead to detrimental effects on human health. Here, we aim to investigate the antimicrobial resistance and the presence of mcr-1 gene in E. coli isolated from chicken feces. Ninety-four E. coli isolates were obtained from samples collected from different locations in Bangladesh, and the isolates were identified using conventional microbiological tests. Phenotypic disk diffusion tests using 20 antimicrobial agents were performed according to CLSI-EUCAST guidelines, and minimum inhibitory concentrations (MICs) were determined for a subset of samples. E. coli isolates showed high resistance to colistin (88.30%), ciprofloxacin (77.66%), trimethoprim/sulfamethoxazole (76.60%), tigecycline (75.53%), and enrofloxacin (71.28%). Additionally, the pathotype eaeA gene was confirmed in ten randomly selected E. coli isolates using primer-specific polymerase chain reaction (PCR). The presence of mcr-1 gene was confirmed using PCR and sequencing analysis in six out of ten E. coli isolates. Furthermore, sequencing and phylogenetic analyses revealed a similarity between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, indicating that the six tested isolates were colistin resistant. Finally, the findings of the present study showed that E. coli isolated from chicken harbored mcr-1 gene, and multidrug and colistin resistance. These findings accentuate the need to implement strict measures to limit the imprudent use of antibiotics, particularly colistin, in agriculture and poultry farms.

OUP accepted manuscript

Background

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) is a major cause of infections worldwide. An understanding of the reservoirs and modes of transmission of these pathogens is essential, to tackle their increasing frequency.

Objectives

We investigated the contributions of various compartments (humans, animals, environment), to human colonization or infection with ESBL-Ec over a 3 year period, on an island.

Methods

The study was performed on Reunion Island (Southwest Indian Ocean). We collected ESBL-Ec isolates prospectively from humans, wastewater and livestock between April 2015 and December 2018. Human specimens were recovered from a regional surveillance system representative of the island’s health facilities. These isolates were compared with those from livestock and urban/rural wastewater, by whole-genome sequencing.

Results

We collected 410 ESBL-Ec isolates: 161 from humans, 161 from wastewater and 88 from animals. Phylogenomic analysis demonstrated high diversity (100 STs), with different STs predominating among isolates from humans (ST131, ST38, ST10) and animals (ST57, ST156). The large majority (90%) of the STs, including ST131, were principally associated with a single compartment. The CTX-M-15, CTX-M-27 and CTX-M-14 enzymes were most common in humans/human wastewater, whereas CTX-M-1 predominated in animals. Isolates of human and animal origin had different plasmids carrying bla_CTX-M genes, with the exception of a conserved IncI1-ST3 bla_CTX-M-1 plasmid.

Conclusions

These molecular data suggest that, despite their high level of contamination, animals are not a major source of the ESBL-Ec found in humans living on this densely populated high-income island. Public health policies should therefore focus primarily on human-to-human transmission, to prevent human infections with ESBL-Ec.

Antibiotic Resistance: One Health One World Outlook

Antibiotic resistance (ABR) is a growing public health concern worldwide, and it is now regarded as a critical One Health issue. One Health’s interconnected domains contribute to the emergence, evolution, and spread of antibiotic-resistant microorganisms on a local and global scale, which is a significant risk factor for global health. The persistence and spread of resistant microbial species, and the association of determinants at the human-animal-environment interface can alter microbial genomes, resulting in resistant superbugs in various niches. ABR is motivated by a well-established link between three domains: human, animal, and environmental health. As a result, addressing ABR through the One Health approach makes sense. Several countries have implemented national action plans based on the One Health approach to combat antibiotic-resistant microbes, following the Tripartite’s Commitment Food and Agriculture Organization (FAO)-World Organization for Animal Health (OIE)-World Health Organization (WHO) guidelines. The ABR has been identified as a global health concern, and efforts are being made to mitigate this global health threat. To summarize, global interdisciplinary and unified approaches based on One Health principles are required to limit the ABR dissemination cycle, raise awareness and education about antibiotic use, and promote policy, advocacy, and antimicrobial stewardship.

Extended-Spectrum Beta-Lactamase-Producing and Carbapenem-Resistant Enterobacterales in Companion and Animal-Assisted Interventions Dogs

Animal-assisted interventions (AAIs) are being implemented in many countries for the beneficial effects they have on humans. Patients involved in AAI are often individuals at greater risk of acquiring infections, and these activities involve close contact between humans and animals, as is the case with humans living with a pet. The spread of multidrug-resistant Enterobacterales is a serious problem for human health; an integrated One Health strategy is imperative to combat this threat. Companion dogs can be a reservoir of multidrug-resistant pathogens, and animal-to-human transmission could occur during AAI sessions. The aim of this review was to collect the available data on the carriage of extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in companion dogs and in an AAI context. Several papers have generally addressed the issue of microbial transmission during AAIs. Studies on the intestinal carriage of extended-spectrum beta-lactamase and/or carbapenem-resistant Enterobacterales have mainly been conducted in companion animals while few data are available on the carriage in dogs participating in AAI sessions. This review aims to draw attention to the antibiotic resistance problem in a One Health context and to the importance of extending infection control measures to this human-animal interface, to keep the balance of benefits/risks for AAIs shifted towards the benefits of these activities.