Genomic characterization of a WHO critical priority isolate Enterobacter kobei ST2070 harboring OXA-10, KPC-2, and CTX-M-12 recovered from a water irrigation channel in Ecuador.

The discharge of untreated or partially treated wastewater can have detrimental impacts on the quality of water bodies, posing a significant threat to public health and the environment. In Ecuador, previous research indicates a high prevalence of antimicrobial resistant (AMR) bacteria in surface waters affected by human activities, including irrigation channels. In this study, we analyzed sediment samples collected from an irrigation channel utilized for agricultural purposes in northern Ecuador, using microbiological techniques and whole-genome sequencing (WGS). Our investigation revealed the first documented occurrence of E. kobei in Ecuador and the initial report of environmental E. kobei ST2070. Furthermore, we identified the coexistence of OXA-10-type class D ß-lactamase and KPC-2-type class A ß-lactamase in the E. kobei isolate (UTA41), representing the first report of such a phenomenon in this species. Additionally, we detected various antibiotic resistance genes in the E. kobei UTA41 isolate, including blaCTX-M-12, fosA, aac(6')-lb, sul2, msr(E), and mph(A), as well as virulence genes such as bacterial efflux pump and siderophore biosynthesis genes. We also identified two intact prophage regions (Entero_186 and Klebsi_phiKO2) in the isolate. Our study presents the first evidence of E. kobei isolate containing two carbapenemase-encoding genes in environmental samples from Latin America. This finding indicates the potential spread of critical-priority bacteria in water samples originating from anthropogenic sources, such as urban wastewater discharges and livestock facilities.

Co-Harboring of Beta-Lactamases and mcr-1 Genes in Escherichia coli and Klebsiella pneumoniae from Healthy Carriers and Backyard Animals in Rural Communities in Ecuador.

Few studies have addressed drug resistance of Enterobacterales in rural communities in developing countries. This study aimed to determine the coexistence of extended-spectrum ß-lactamase (ESBL) and carbapenemase genes in Escherichia coli and Klebsiella pneumoniae strains carrying the mcr-1 gene in rural communities in Ecuador from healthy humans and their backyard animals. Sixty-two strains, thirty E. coli and thirty-two K. pneumoniae strains carrying the mcr-1 gene were selected from a previous study. PCR were performed for the presence of ESBLs and carbapenemase genes. The strains were further characterized, and the genetic relationship was studied with multi-locus sequencing typing (MLST) of seven housekeeping genes. Fifty-nine of the sixty-two mcr-1 isolates (95%) harbored at least on ß-lactam resistance gene. The most prevalent ESBL genes were the blaTEM genes (present in in 80% of the E. coli strains) and the blaSHV gene (present in 84% of the K. pneumoniae strains). MSLT analysis revealed 28 different sequence types (ST); 15 for E. coli and 12 for K. pneumoniae, with most ST never described in humans and animals. The coexistence of mcr-1 and ß-lactams resistant genes in E. coli and K. pneumoniae strains is alarming and threatens the efficacy of last-resort antibiotics. Our findings highlight backyard animals as a reservoir of mcr-1/ß-lactams resistant genes.

Colistin resistance in Escherichia coli and Klebsiella pneumoniae in humans and backyard animals in Ecuador.

Objective: Colistin is an antibiotic of last resort for treating serious Gram-negative bacterial infections. However, the misuse of colistin, especially as an animal growth promoter, has contributed to increasing antimicrobial resistance, mediated mainly through plasmid transfer of the mcr-1 gene. This study assessed the prevalence of phenotypic and molecular colistin resistance in Escherichia coli and Klebsiella pneumoniae in Ecuador in healthy humans and their chickens and pigs. Methods: Fecal samples were collected from humans and their chickens and pigs in two rural coastal and Amazon regions between April and August 2020. Gram-negative bacteria were isolated and identified using conventional techniques. Phenotypic resistance was determined using the broth microdilution technique, and the mcr-1 gene was detected using conventional polymerase chain reaction. Results: A total of 438 fecal samples were obtained from 137 humans, 147 pigs and 154 chickens. The prevalence of E. coli isolates was 86.3% (378/438) and K. pneumoniae, 37.4% (164/438). Overall, the mcr-1 gene was found in 90% (340/378) of E. coli isolates, with higher prevalences found in isolates from coastal regions (96.5%, 191/198), humans (95.6%, 111/116) and chickens (91.8%, 123/134); for K. pneumoniae, the gene was found in 19.5% (32/164) of isolates, with equal distribution between regions and hosts. Only four isolates, two E. coli and two K. pneumoniae, showed phenotypic resistance: mcr-1 was present in both E. coli strains but absent in the K. pneumoniae strains. Conclusions: Despite a low prevalence of phenotypic resistance to colistin, the high prevalence of the mcr-1 gene in E. coli is of concern. Ecuador's ban on using colistin in animal husbandry must be enforced, and continual monitoring of the situation should be implemented.

Whole-genome sequencing for surveillance of antimicrobial resistance in Ecuador: present and future implications.

Whole-genome sequencing is becoming the gold standard for pathogen characterization and offers considerable advantages for understanding the evolution and dissemination of new determinants of antimicrobial resistance. Despite the benefits of whole-genome sequencing for pathogen characterization, implementation costs and lack of expertise may limit its use by public health laboratories. This article reviews the advantages of whole-genome sequencing for pathogen characterization and the current status of the use of whole-genome sequencing for antimicrobial resistance surveillance in Ecuador. A roadmap is suggested for including whole-genome sequencing for pathogen characterization based on the needs of the health reference institutions through alliances with Ecuadorian universities. Establishing a partnership between public health institutions and academia would be valuable for clinicians, policy-makers, and epidemiologists who could then take reasonable measures in those areas and establish a basis for adapting One Health strategies to tackle antimicrobial resistance in Ecuador.

La secuenciación del genoma completo, que está pasando a ser el estándar de referencia para la caracterización de agentes patógenos, ofrece ventajas considerables para comprender la evolución y la diseminación de los nuevos determinantes de la resistencia a los antimicrobianos. Sin embargo, a pesar de los beneficios que genera, los costos de ejecución y la falta de experiencia pueden limitar su uso por parte de los laboratorios de salud pública. En este artículo se evalúan las ventajas de la secuenciación del genoma completo para la caracterización de agentes patógenos y el estado actual del uso de la secuenciación del genoma completo en la vigilancia de la resistencia a los antimicrobianos en Ecuador. Se propone una hoja de ruta para incluir la secuenciación del genoma completo para la caracterización de agentes patógenos según las necesidades de las instituciones de salud de referencia, lo que se haría por medio de alianzas con universidades ecuatorianas. Establecer una asociación entre las instituciones de salud pública y los círculos académicos sería sumamente valioso para los médicos, los responsables de las políticas y los epidemiólogos, que podrían adoptar medidas razonables en sus ámbitos y sentar una base para adaptar las estrategias de "Una salud" a fin de abordar la resistencia a los antimicrobianos en Ecuador.

O sequenciamento do genoma completo está se tornando o padrão ouro para a caracterização de patógenos e oferece vantagens consideráveis para a compreensão da evolução e disseminação de novos determinantes de resistência aos antimicrobianos. Apesar dos benefícios do sequenciamento do genoma completo para a caracterização de patógenos, os custos de implementação e a falta de especialização podem limitar seu uso pelos laboratórios de saúde pública. Este artigo analisa as vantagens do sequenciamento do genoma completo para a caracterização de patógenos e a situação atual do uso desta técnica para a vigilância da resistência aos antimicrobianos no Equador. Sugere-se um roteiro para incluir o sequenciamento de genomas completos para caracterização de patógenos com base nas necessidades das instituições de saúde de referência, por meio de alianças com universidades equatorianas. A criação de uma parceria entre instituições de saúde pública e entidades acadêmicas seria valiosa para clínicos, formuladores de políticas e epidemiologistas, que poderiam, assim, tomar medidas razoáveis nessas áreas e estabelecer uma base para adaptar estratégias de Saúde Única para combater a resistência aos antimicrobianos no Equador.

Colistin resistance in Escherichia coli and Klebsiella pneumoniae in humans and backyard animals in Ecuador

[ABSTRACT]. Objective. Colistin is an antibiotic of last resort for treating serious Gram-negative bacterial infections. However, the misuse of colistin, especially as an animal growth promoter, has contributed to increasing antimicrobial resistance, mediated mainly through plasmid transfer of the mcr-1 gene. This study assessed the prevalence of phenotypic and molecular colistin resistance in Escherichia coli and Klebsiella pneumoniae in Ecuador in healthy humans and their chickens and pigs. Methods. Fecal samples were collected from humans and their chickens and pigs in two rural coastal and Amazon regions between April and August 2020. Gram-negative bacteria were isolated and identified using conventional techniques. Phenotypic resistance was determined using the broth microdilution technique, and the mcr-1 gene was detected using conventional polymerase chain reaction. Results. A total of 438 fecal samples were obtained from 137 humans, 147 pigs and 154 chickens. The preva- lence of E. coli isolates was 86.3% (378/438) and K. pneumoniae, 37.4% (164/438). Overall, the mcr-1 gene was found in 90% (340/378) of E. coli isolates, with higher prevalences found in isolates from coastal regions (96.5%, 191/198), humans (95.6%, 111/116) and chickens (91.8%, 123/134); for K. pneumoniae, the gene was found in 19.5% (32/164) of isolates, with equal distribution between regions and hosts. Only four isolates, two E. coli and two K. pneumoniae, showed phenotypic resistance: mcr-1 was present in both E. coli strains but absent in the K. pneumoniae strains. Conclusions. Despite a low prevalence of phenotypic resistance to colistin, the high prevalence of the mcr-1 gene in E. coli is of concern. Ecuador’s ban on using colistin in animal husbandry must be enforced, and con- tinual monitoring of the situation should be implemented.

[RESUMEN]. Objetivo. La colistina es un antibiótico de último recurso para tratar infecciones graves por bacterias gramneg- ativas. Sin embargo, su uso indebido, especialmente para estimular el crecimiento animal, ha contribuido con el aumento de la resistencia a los antimicrobianos, mediada principalmente por la transferencia de plásmidos del gen mcr-1. En este estudio se evaluó la prevalencia de la resistencia fenotípica y molecular a la colistina de las bacterias Escherichia coli y Klebsiella pneumoniae en humanos sanos, sus pollos y cerdos en Ecuador. Métodos. Se recolectaron muestras fecales de humanos, así como de sus pollos y cerdos, en dos zonas rurales de la región costera y la región amazónica entre abril y agosto del 2020. Se aislaron las bacterias gramnegativas y se identificaron empleando técnicas convencionales. Se determinó la resistencia fenotípica mediante la técnica de microdilución en caldo y se detectó el gen mcr-1 con la técnica convencional de reac- ción en cadena de la polimerasa. Resultados. Se obtuvo un total de 438 muestras fecales de 137 humanos, 147 cerdos y 154 pollos. La preva- lencia de E. coli en las cepas aisladas fue del 86,3% (378/438) y la de K. pneumoniae, del 37,4% (164/438). En general, se detectó el gen mcr-1 en el 90% (340/378) de las cepas aisladas de E. coli y la mayor prevalencia encontrada fue en cepas aisladas de la región costera (96,5%, 191/198), humanos (95,6%, 111/116) y pollos (91,8%, 123/134); en el caso de K. pneumoniae, el gen se encontró en el 19,5% (32/164) de las cepas, con una distribución equitativa entre regiones y hospedadores. Únicamente cuatro cepas aisladas, dos de E. coli y dos de K. pneumoniae, mostraron resistencia fenotípica: el gen mcr-1 estaba presente en ambas cepas de E. coli y ausente en las cepas de K. pneumoniae. Conclusiones. Si bien hubo una baja prevalencia de resistencia fenotípica a la colistina, la alta prevalencia del gen mcr-1 en E. coli es preocupante. Es necesario hacer cumplir la prohibición del uso de colistina en la cría de animales en Ecuador, así como realizar un seguimiento continuo de la situación.

[RESUMO]. Objetivo. A colistina é um antibiótico de último recurso para o tratamento de infecções graves por bac- térias Gram-negativas. Entretanto, o uso indevido da colistina, principalmente como promotor de crescimento animal, tem contribuído para o aumento da resistência a antimicrobianos, principalmente por transferência horizontal do gene mcr-1 mediada por plasmídeos. Este estudo avaliou a prevalência de resistência fenotípica e molecular à colistina em Escherichia coli e Klebsiella pneumoniae no Equador em humanos hígidos e em galinhas e porcos por eles criados. Métodos. Entre abril e agosto de 2020, foram coletadas amostras de fezes de habitantes de duas regiões litorâneas e amazônicas do Equador e de galinhas e porcos por eles criados. Bactérias Gram-negativas foram isoladas e identificadas por meio de técnicas convencionais. A resistência fenotípica foi determinada pela técnica de microdiluição em caldo, e o gene mcr-1 foi detectado por reação em cadeia da polimerase convencional. Resultados. Foram obtidas 438 amostras fecais de 137 humanos, 147 suínos e 154 galinhas. A prevalência de isolados de E. coli foi de 86,3% (378/438), e de K. pneumoniae, 37,4% (164/438). Em geral, o gene mcr-1 foi encontrado em 90% (340/378) dos isolados de E. coli, com maiores prevalências encontradas em isola- dos de regiões litorâneas (96,5%, 191/198), humanos (95,6%, 111/116) e galinhas (91,8%, 123/134); para K. pneumoniae, o gene foi encontrado em 19,5% (32/164) dos isolados, com igual distribuição entre regiões e hospedeiros. Somente quatro isolados, dois de E. coli e dois de K. pneumoniae, demonstraram resistência fenotípica: o gene mcr-1 estava presente em ambas as cepas de E. coli, mas ausente nas de K. pneumoniae. Conclusões. Apesar da baixa prevalência de resistência fenotípica à colistina, a alta prevalência do gene mcr-1 em E. coli é preocupante. É preciso fiscalizar a proibição ao uso agropecuário de colistina no Equador e implementar o monitoramento contínuo da situação.

Whole-genome sequencing for surveillance of antimicrobial resistance in Ecuador: present and future implications

[ABSTRACT]. Whole-genome sequencing is becoming the gold standard for pathogen characterization and offers consid- erable advantages for understanding the evolution and dissemination of new determinants of antimicrobial resistance. Despite the benefits of whole-genome sequencing for pathogen characterization, implementation costs and lack of expertise may limit its use by public health laboratories. This article reviews the advantages of whole-genome sequencing for pathogen characterization and the current status of the use of whole-ge- nome sequencing for antimicrobial resistance surveillance in Ecuador. A roadmap is suggested for including whole-genome sequencing for pathogen characterization based on the needs of the health reference insti- tutions through alliances with Ecuadorian universities. Establishing a partnership between public health institutions and academia would be valuable for clinicians, policy-makers, and epidemiologists who could then take reasonable measures in those areas and establish a basis for adapting One Health strategies to tackle antimicrobial resistance in Ecuador.

[RESUMEN]. La secuenciación del genoma completo, que está pasando a ser el estándar de referencia para la caracteri- zación de agentes patógenos, ofrece ventajas considerables para comprender la evolución y la diseminación de los nuevos determinantes de la resistencia a los antimicrobianos. Sin embargo, a pesar de los beneficios que genera, los costos de ejecución y la falta de experiencia pueden limitar su uso por parte de los laborato- rios de salud pública. En este artículo se evalúan las ventajas de la secuenciación del genoma completo para la caracterización de agentes patógenos y el estado actual del uso de la secuenciación del genoma completo en la vigilancia de la resistencia a los antimicrobianos en Ecuador. Se propone una hoja de ruta para incluir la secuenciación del genoma completo para la caracterización de agentes patógenos según las necesidades de las instituciones de salud de referencia, lo que se haría por medio de alianzas con universidades ecua- torianas. Establecer una asociación entre las instituciones de salud pública y los círculos académicos sería sumamente valioso para los médicos, los responsables de las políticas y los epidemiólogos, que podrían adoptar medidas razonables en sus ámbitos y sentar una base para adaptar las estrategias de “Una salud” a fin de abordar la resistencia a los antimicrobianos en Ecuador.

[RESUMO]. O sequenciamento do genoma completo está se tornando o padrão ouro para a caracterização de patógenos e oferece vantagens consideráveis para a compreensão da evolução e disseminação de novos determi- nantes de resistência aos antimicrobianos. Apesar dos benefícios do sequenciamento do genoma completo para a caracterização de patógenos, os custos de implementação e a falta de especialização podem lim- itar seu uso pelos laboratórios de saúde pública. Este artigo analisa as vantagens do sequenciamento do genoma completo para a caracterização de patógenos e a situação atual do uso desta técnica para a vig- ilância da resistência aos antimicrobianos no Equador. Sugere-se um roteiro para incluir o sequenciamento de genomas completos para caracterização de patógenos com base nas necessidades das instituições de saúde de referência, por meio de alianças com universidades equatorianas. A criação de uma parceria entre instituições de saúde pública e entidades acadêmicas seria valiosa para clínicos, formuladores de políticas e epidemiologistas, que poderiam, assim, tomar medidas razoáveis nessas áreas e estabelecer uma base para adaptar estratégias de Saúde Única para combater a resistência aos antimicrobianos no Equador.

Colistin resistance in Escherichia coli and Klebsiella pneumoniae in humans and backyard animals in Ecuador / Resistencia a la colistina de las bacterias Escherichia coli y Klebsiella pneumoniae en humanos y animales de granja en Ecuador / Resistência à colistina em Escherichia coli e Klebsiella pneumoniae em humanos e animais de quintal no Equador

ABSTRACT Objective. Colistin is an antibiotic of last resort for treating serious Gram-negative bacterial infections. However, the misuse of colistin, especially as an animal growth promoter, has contributed to increasing antimicrobial resistance, mediated mainly through plasmid transfer of the mcr-1 gene. This study assessed the prevalence of phenotypic and molecular colistin resistance in Escherichia coli and Klebsiella pneumoniae in Ecuador in healthy humans and their chickens and pigs. Methods. Fecal samples were collected from humans and their chickens and pigs in two rural coastal and Amazon regions between April and August 2020. Gram-negative bacteria were isolated and identified using conventional techniques. Phenotypic resistance was determined using the broth microdilution technique, and the mcr-1 gene was detected using conventional polymerase chain reaction. Results. A total of 438 fecal samples were obtained from 137 humans, 147 pigs and 154 chickens. The prevalence of E. coli isolates was 86.3% (378/438) and K. pneumoniae, 37.4% (164/438). Overall, the mcr-1 gene was found in 90% (340/378) of E. coli isolates, with higher prevalences found in isolates from coastal regions (96.5%, 191/198), humans (95.6%, 111/116) and chickens (91.8%, 123/134); for K. pneumoniae, the gene was found in 19.5% (32/164) of isolates, with equal distribution between regions and hosts. Only four isolates, two E. coli and two K. pneumoniae, showed phenotypic resistance: mcr-1 was present in both E. coli strains but absent in the K. pneumoniae strains. Conclusions. Despite a low prevalence of phenotypic resistance to colistin, the high prevalence of the mcr-1 gene in E. coli is of concern. Ecuador's ban on using colistin in animal husbandry must be enforced, and continual monitoring of the situation should be implemented.

resumen está disponible en el texto completo

RESUMO Objetivo. A colistina é um antibiótico de último recurso para o tratamento de infecções graves por bactérias Gram-negativas. Entretanto, o uso indevido da colistina, principalmente como promotor de crescimento animal, tem contribuído para o aumento da resistência a antimicrobianos, principalmente por transferência horizontal do gene mcr-1 mediada por plasmídeos. Este estudo avaliou a prevalência de resistência fenotípica e molecular à colistina em Escherichia coli e Klebsiella pneumoniae no Equador em humanos hígidos e em galinhas e porcos por eles criados. Métodos. Entre abril e agosto de 2020, foram coletadas amostras de fezes de habitantes de duas regiões litorâneas e amazônicas do Equador e de galinhas e porcos por eles criados. Bactérias Gram-negativas foram isoladas e identificadas por meio de técnicas convencionais. A resistência fenotípica foi determinada pela técnica de microdiluição em caldo, e o gene mcr-1 foi detectado por reação em cadeia da polimerase convencional. Resultados. Foram obtidas 438 amostras fecais de 137 humanos, 147 suínos e 154 galinhas. A prevalência de isolados de E. coli foi de 86,3% (378/438), e de K. pneumoniae, 37,4% (164/438). Em geral, o gene mcr-1 foi encontrado em 90% (340/378) dos isolados de E. coli, com maiores prevalências encontradas em isolados de regiões litorâneas (96,5%, 191/198), humanos (95,6%, 111/116) e galinhas (91,8%, 123/134); para K. pneumoniae, o gene foi encontrado em 19,5% (32/164) dos isolados, com igual distribuição entre regiões e hospedeiros. Somente quatro isolados, dois de E. coli e dois de K. pneumoniae, demonstraram resistência fenotípica: o gene mcr-1 estava presente em ambas as cepas de E. coli, mas ausente nas de K. pneumoniae. Conclusões. Apesar da baixa prevalência de resistência fenotípica à colistina, a alta prevalência do gene mcr-1 em E. coli é preocupante. É preciso fiscalizar a proibição ao uso agropecuário de colistina no Equador e implementar o monitoramento contínuo da situação.

Whole-genome sequencing for surveillance of antimicrobial resistance in Ecuador: present and future implications / Secuenciación del genoma completo para la vigilancia de la resistencia a los antimicrobianos en Ecuador: implicaciones actuales y futuras / Sequenciamento do genoma completo para vigilância da resistência aos antimicrobianos no Equador: implicações presentes e futuras

ABSTRACT Whole-genome sequencing is becoming the gold standard for pathogen characterization and offers considerable advantages for understanding the evolution and dissemination of new determinants of antimicrobial resistance. Despite the benefits of whole-genome sequencing for pathogen characterization, implementation costs and lack of expertise may limit its use by public health laboratories. This article reviews the advantages of whole-genome sequencing for pathogen characterization and the current status of the use of whole-genome sequencing for antimicrobial resistance surveillance in Ecuador. A roadmap is suggested for including whole-genome sequencing for pathogen characterization based on the needs of the health reference institutions through alliances with Ecuadorian universities. Establishing a partnership between public health institutions and academia would be valuable for clinicians, policy-makers, and epidemiologists who could then take reasonable measures in those areas and establish a basis for adapting One Health strategies to tackle antimicrobial resistance in Ecuador.

RESUMEN La secuenciación del genoma completo, que está pasando a ser el estándar de referencia para la caracterización de agentes patógenos, ofrece ventajas considerables para comprender la evolución y la diseminación de los nuevos determinantes de la resistencia a los antimicrobianos. Sin embargo, a pesar de los beneficios que genera, los costos de ejecución y la falta de experiencia pueden limitar su uso por parte de los laboratorios de salud pública. En este artículo se evalúan las ventajas de la secuenciación del genoma completo para la caracterización de agentes patógenos y el estado actual del uso de la secuenciación del genoma completo en la vigilancia de la resistencia a los antimicrobianos en Ecuador. Se propone una hoja de ruta para incluir la secuenciación del genoma completo para la caracterización de agentes patógenos según las necesidades de las instituciones de salud de referencia, lo que se haría por medio de alianzas con universidades ecuatorianas. Establecer una asociación entre las instituciones de salud pública y los círculos académicos sería sumamente valioso para los médicos, los responsables de las políticas y los epidemiólogos, que podrían adoptar medidas razonables en sus ámbitos y sentar una base para adaptar las estrategias de "Una salud" a fin de abordar la resistencia a los antimicrobianos en Ecuador.

RESUMO O sequenciamento do genoma completo está se tornando o padrão ouro para a caracterização de patógenos e oferece vantagens consideráveis para a compreensão da evolução e disseminação de novos determinantes de resistência aos antimicrobianos. Apesar dos benefícios do sequenciamento do genoma completo para a caracterização de patógenos, os custos de implementação e a falta de especialização podem limitar seu uso pelos laboratórios de saúde pública. Este artigo analisa as vantagens do sequenciamento do genoma completo para a caracterização de patógenos e a situação atual do uso desta técnica para a vigilância da resistência aos antimicrobianos no Equador. Sugere-se um roteiro para incluir o sequenciamento de genomas completos para caracterização de patógenos com base nas necessidades das instituições de saúde de referência, por meio de alianças com universidades equatorianas. A criação de uma parceria entre instituições de saúde pública e entidades acadêmicas seria valiosa para clínicos, formuladores de políticas e epidemiologistas, que poderiam, assim, tomar medidas razoáveis nessas áreas e estabelecer uma base para adaptar estratégias de Saúde Única para combater a resistência aos antimicrobianos no Equador.

A PMAxxTM qPCR Assay Reveals That Dietary Administration of the Microalgae Tetraselmis chuii Does Not Affect Salmonella Infantis Caecal Content in Early-Treated Broiler Chickens.

Salmonella enterica serovars cause infections in humans. S. enterica subsp. enterica serovar Infantis is considered relevant and is commonly reported in poultry products. Evaluating innovative approaches for resisting colonization in animals could contribute to the goal of reducing potential human infections. Microalgae represent a source of molecules associated with performance and health improvement in chickens. Tetraselmis chuii synthesizes fermentable polysaccharides as part of their cell wall content; these sugars are known for influencing caecal bacterial diversity. We hypothesized if its dietary administration could exert a positive effect on caecal microbiota in favor of a reduced S. Infantis load. A total of 72 one-day-old broiler chickens (COBB 500) were randomly allocated into three groups: a control, a group infected with bacteria (day 4), and a group challenged with S. Infantis but fed a microalgae-based diet. Caecal samples (n = 8) were collected two days post-infection. A PMAxxTM-based qPCR approach was developed to assess differences regarding bacterial viable load between groups. The inclusion of the microalga did not modify S. Infantis content, although the assay proved to be efficient, sensitive, and repeatable. The utilized scheme could serve as a foundation for developing novel PCR-based methodologies for estimating Salmonella colonization.

Data on antibiograms and resistance genes of Enterobacterales isolated from ready-to-eat street food of Ambato, Ecuador.

Foodborne pathogens represent a significant cause of negative impacts on human health and the economy worldwide. Unfortunately, information about epidemiological insights in Latin American countries is scarce. The consumption of ready-to-eat street food in Ecuador is extensive, and information about the presence of foodborne pathogens, their virulence factors, and antimicrobial resistance is negligible. This data includes the occurrence, phenotypic antibiotic resistance profiles, and antibiotic resistance genes of Enterobacterales isolated from ready-to-eat street food in Ambato, central Ecuador during 2020 and 2021. The most common genera detected were Escherichia coli, Klebsiella spp., and Cronobacter spp. Agar disk diffusion assays were performed to determine their phenotypic resistance. The presence of antibiotic resistance genes conferring resistance against colistin, ß-Lactams, aminoglycosides, tetracyclines, sulfonamides, fluoroquinolones, and amphenicols was detected via polymerase chain reaction (PCR) amplification.

Data on antibiogram and resistance genes of Enterobacterales isolated from fresh vegetables in Ecuador.

This article describes the occurrence, antibiograms, and detection of antibiotic resistance genes of Enterobacterales isolated from fresh vegetables commercialized in Riobamba, Ecuador. Escherichia coli isolates were screened to detect diarrheagenic pathotypes via PCR. Agar diffusion assay was performed to determine the phenotypic antibiotic resistance of the Enterobacterales strains. The presence of antibiotic resistance genes conferring resistance against beta-lactams, mobile colistin resistance, carbapenems, quinolones, tetracyclines, and sulphonamides was detected via PCR amplification.

Characterization of the genetic structure of mcr-1 gene among Escherichia coli isolates recovered from surface waters and sediments from Ecuador.

Although anthropogenic activities contribute to the selection and spread of antibiotic resistance in aquatic environments, limited information is available from countries with absent or incomplete sewage treatment systems and the impact of their discharges onto water bodies. This study therefore aimed to characterize the genetic structure of colistin resistance (mcr) genes among Escherichia coli isolates recovered from surface waters and sediments in Ecuador. Out of 459 isolates, four Escherichia coli showed multidrug-resistant phenotypes, which harbored the mcr-1 gene and ß-lactamases, such as blaTEM, blaCTX-M-15, blaCTX-M-55, or blaCTX-M-65 genes. Three E. coli isolates (U20, U30 and U144) shared a similar genetic environment surrounding the mcr-1 gene, which was located on plasmids. Only one E. coli isolate (U175) showed that the mcr-1 gene was chromosomally located. Moreover, the core genome multilocus sequence typing (cgMLST) analysis revealed that these isolates belong to different lineages. This study represents the first detection of the mcr-1 gene in multidrug-resistant E. coli isolates from environmental samples in Ecuador.

Genomic insights of mcr-1 harboring Escherichia coli by geographical region and a One-Health perspective.

The importance of the One Health concept in attempting to deal with the increasing levels of multidrug-resistant bacteria in both human and animal health is a challenge for the scientific community, policymakers, and the industry. The discovery of the plasmid-borne mobile colistin resistance (mcr) in 2015 poses a significant threat because of the ability of these plasmids to move between different bacterial species through horizontal gene transfer. In light of these findings, the World Health Organization (WHO) recommends that countries implement surveillance strategies to detect the presence of plasmid-mediated colistin-resistant microorganisms and take suitable measures to control and prevent their dissemination. Seven years later, ten different variants of the mcr gene (mcr-1 to mcr-10) have been detected worldwide in bacteria isolated from humans, animals, foods, the environment, and farms. However, the possible transmission mechanisms of the mcr gene among isolates from different geographical origins and sources are largely unknown. This article presents an analysis of whole-genome sequences of Escherichia coli that harbor mcr-1 gene from different origins (human, animal, food, or environment) and geographical location, to identify specific patterns related to virulence genes, plasmid content and antibiotic resistance genes, as well as their phylogeny and their distribution with their origin. In general, E. coli isolates that harbor mcr-1 showed a wide plethora of ARGs. Regarding the plasmid content, the highest concentration of plasmids was found in animal samples. In turn, Asia was the continent that led with the largest diversity and occurrence of these plasmids. Finally, about virulence genes, terC, gad, and traT represent the most frequent virulence genes detected. These findings highlight the relevance of analyzing the environmental settings as an integrative part of the surveillance programs to understand the origins and dissemination of antimicrobial resistance.

Administration of Dietary Microalgae Ameliorates Intestinal Parameters, Improves Body Weight, and Reduces Thawing Loss of Fillets in Broiler Chickens: A Pilot Study.

This pilot investigation aimed at studying the feasibility of using a low dose (0.2%) of dietary microalgae as a means of improving intestinal morphometry, body weight, and selected meat quality parameters in broilers. A total of 72 one-day-old ROSS 308 male chicks were randomly separated into four groups; three experimental pens in which the birds were fed with biomass from Tysochrysis lutea, Tetraselmis chuii, and Porphyridium cruentum over 30 days and a control group. T. chuii and P. cruentum had a positive effect with regard to body weight. In treated animals, duodenal and ileal sections showed characteristic tall and thin villi, with serrated surfaces and goblet cell differentiation. In both sections, values of the villus-height-to-crypt-depth ratio were increased by microalgae ingestion. The thawing weight loss of fillets was reduced in T. chuii-fed animals. The positive effects exerted by T. chuii and P. cruentum on intestinal architecture were associated with the improved body weight. Arguably, these outcomes exhibit the potential of using these species to enhance growth performance in broiler chickens by promoting gut homeostasis and thus nutrient absorption.

Population genomics and antimicrobial resistance dynamics of Escherichia coli in wastewater and river environments.

Aquatic environments are key niches for the emergence, evolution and dissemination of antimicrobial resistance. However, the population diversity and the genetic elements that drive the dynamics of resistant bacteria in different aquatic environments are still largely unknown. The aim of this study was to understand the population genomics and evolutionary events of Escherichia coli resistant to clinically important antibiotics including aminoglycosides, in anthropogenic and natural water ecosystems. Here we show that less different E. coli sequence types (STs) are identified in wastewater than in rivers, albeit more resistant to antibiotics, and with significantly more plasmids/cell (6.36 vs 3.72). However, the genomic diversity within E. coli STs in both aquatic environments is similar. Wastewater environments favor the selection of conserved chromosomal structures associated with diverse flexible plasmids, unraveling promiscuous interplasmidic resistance genes flux. On the contrary, the key driver for river E. coli adaptation is a mutable chromosome along with few plasmid types shared between diverse STs harboring a limited resistance gene content.

Selection for feed efficiency using the social effects animal model in growing Duroc pigs: evaluation by simulation.

BACKGROUND: Traits recorded on animals that are raised in groups can be analysed with the social effects animal model (SAM). For multiple traits, this model specifies the genetic correlation structure more completely than the animal model (AM). Our hypothesis was that by using the SAM for genetic evaluation of average daily gain (ADG) and backfat thickness (BF), a high rate of improvement in feed conversion ratio (FCR) might be achieved, since unfavourable genetic correlations between ADG and BF reported in a Duroc pig line could be partially avoided. We estimated genetic and non-genetic correlations between BF, ADG and FCR on 1144 pigs using Bayesian methods considering the SAM; and responses to selection indexes that combine estimates of indirect (IGE) and direct (DGE) genetic effects for ADG and BF by stochastic simulation. RESULTS: Estimates of the ratio of the variance of DGE to the phenotypic variance were 0.31, 0.39 and 0.25 and those of the total genetic variance to the phenotypic variance were 0.63, 0.74 and 0.93 for ADG, BF and FCR, respectively. In spite of this, when the SAM was used to generate data and for the genetic evaluations, the average economic response was worse than that obtained when BV predictions from the AM were considered. The achieved economic response was due to a direct reduction in BF and not to an improvement in FCR. CONCLUSIONS: Our results show that although social genetic effects play an important role in the traits studied, their proper consideration in pig breeding programs to improve FCR indirectly is still difficult. The correlations between IGE and DGE that could help to overcome the unfavourable genetic correlations between DGE did not reach sufficiently high magnitudes; also, the genetic parameters estimates from the SAM have large errors. These two factors penalize the average response under the SAM compared to the AM.