RESUMEN

This study investigates the presence of virulence-associated genes and antimicrobial resistance (AMR) in Escherichia fergusonii isolates obtained from ostrich chicks. A total of 287 isolates were recovered from 106 fecal samples from ostrich chicks suffering from diarrhea and subjected to molecular identification and biochemical characterization. E. fergusonii was detected in 10 samples (9.4 %) using two PCR-detection protocols. Notably, the isolates lacked various virulence genes commonly associated with pathogenic E. coli including elt, est, stx, eae, ehly, cdt, iss, iutA, iroN, hlyA, ompT, except for one isolate harboring the astA gene. Antimicrobial susceptibility testing revealed that all isolates were susceptible to ciprofloxacin, while high resistance was observed against amoxicillin clavulanate (AMC), trimethoprim-sulfamethoxazole (SXT), and doxycycline (D). Moreover, eight isolates displayed multidrug resistance (MDR) and four exhibited resistance to 9-11 antimicrobials. The most frequent resistance gene was sul2, which was present in all isolates; the other resistance genes detected consisted of int1 (4/10), int2 (3/10), blaCMY (2/10), and qnrS, blaTEM, blaCMY, blaCTX-M, and flo each were detected only in one E. fergusonii Isolate. Plasmid replicon typing identified the presence of I1 (7/10), N (5/10), and Y (1/10). This study provides valuable insights into the virulence and antimicrobial resistance of E. fergusonii isolates from ostrich chicks, highlighting the complexity of antimicrobial resistance mechanisms exhibited by these bacteria. Further research is essential to understand the transmission dynamics and clinical implications of these findings in veterinary and public health settings.

Asunto(s)

Antibacterianos , Escherichia , Heces , Pruebas de Sensibilidad Microbiana , Struthioniformes , Animales , Struthioniformes/microbiología , Antibacterianos/farmacología , Escherichia/genética , Escherichia/efectos de los fármacos , Escherichia/patogenicidad , Escherichia/aislamiento & purificación , Heces/microbiología , Virulencia/genética , Factores de Virulencia/genética , Farmacorresistencia Bacteriana Múltiple/genética , Diarrea/microbiología , Diarrea/veterinaria , Infecciones por Enterobacteriaceae/veterinaria , Infecciones por Enterobacteriaceae/microbiología , Farmacorresistencia Bacteriana/genética , Enfermedades de las Aves/microbiología , Genes Bacterianos/genética

RESUMEN

Introducción: El apego a las normas oficiales sanitarias sirve para prevenir riesgos a la salud humana. Objetivo: Evaluar la calidad higiénico-sanitaria y las buenas prácticas de manufactura de alimentos (BPMA) de un comedor estudiantil en México. Materiales y métodos: Estudio cuasiexperimental y analítico. Durante el año 2020, se realizaron pruebas bacteriológicas a muestras de alimentos, agua, superficies y manos de manipuladores de alimentos, además de también evaluar las BPMA. Conforme a las normas oficiales sanitarias vigentes en México, se recolectaron 57 muestras, se aislaron y se lograron identificar patógenos. Las BPMA se valoraron en 20 manipuladores, antes y después de una intervención educativa de 10 semanas de duración y se utilizó la prueba t con α=0,05. Resultados: Más del 50 % de las muestras resultaron con microorganismos de riesgo para la salud, como Escherichia coli, Staphylococcus aureus, Pseudomonas, Acinetobacter baumanni complex y Coliformes totales. Las evaluaciones, antes y después de la intervención educativa de BPMA, evidenciaron diferencias estadísticamente significativas en el número de aciertos (p≤0,05). Conclusiones: La calidad higiénico-sanitaria del comedor analizado representó riesgo para la salud de los estudiantes, lo cual tuvo relación con la primera evaluación de las BPMA entre los manipuladores, las cuales mejoraron después de la intervención.

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Introduction: Adherence to official health standards is essential to prevent human health risks. Objective: To assess the hygienic-sanitary quality and good food manufacturing practices (GMP) in a student cafeteria in Mexico. Materials and methods: Quasi-experimental and analytical study. During 2020, bacteriological tests were carried out on samples taken from food, water, surfaces, and hands of food handlers. In addition, GMP were evaluated. Based on the current Mexican official health regulations, 57 samples were collected to isolate and identify pathogens. GMP were assessed in 20 food handlers before and after a 10-week training intervention and a test was used with α=0.05. Results: More than 50% of samples were found to have microorganisms associated with health risks, including Escherichia coli, Staphylococcus aureus, Pseudomonas, Acinetobacter baumanni complex and total Coliforms. The analyses before and after the GMP training intervention showed statistically significant differences in terms of the presence of these pathogens (p≤0.05). Conclusions: The hygienic-sanitary quality of the analyzed cafeteria turned out to be a risk for the health of students, which was related to the first assessment of GMP in food handlers. Consequently, the results improved after the intervention.

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Introdução: A adesão às normas sanitárias oficiais serve para prevenir riscos à saúde humana. Objetivo: Avaliar a qualidade higiênico-sanitária e as boas práticas de fabricação de alimentos (BPMA) de um refeitorio estudantil no México. Materiais e métodos: Estudo quase-experimental e analítico. Durante 2020, foram realizados testes bacteriológicos em amostras de alimentos, água, superfícies e mãos de manipuladores de alimentos, além de avaliação de BPMA. De acordo com as normas sanitárias oficiais em vigor no México, foram coletadas e isoladas 57 amostras e identificados patógenos. Os BPMA foram avaliados em 20 manipuladores, antes e após uma intervenção educativa de 10 semanas e foi utilizado o teste t com α=0,05. Resultados: Verificou-se que mais de 50% das amostras continham microrganismos de risco à saúde, como Escherichia coli, Staphylococcus aureus, Pseudomonas, complexo Acinetobacter baumanni e Coliformes totais. As avaliações, antes e após a intervenção educativa BPMA, apresentaram diferenças estatisticamente significativas no número de acertos (p≤0,05). Conclusões: A qualidade higiênico-sanitária do refeitório analisado representou um risco para a saúde dos alunos, o que esteve relacionado à primeira avaliação do BPMA entre os manipuladores, que melhorou após a intervenção.

Asunto(s)

Humanos , Masculino , Femenino , Educación en Salud , Enterobacteriaceae , Vigilancia Sanitaria de Productos , Salmonella , Escherichia , Alimentos

RESUMEN

Ubiquitination pathways have crucial roles in protein homeostasis, signalling and innate immunity1-3. In these pathways, an enzymatic cascade of E1, E2 and E3 proteins conjugates ubiquitin or a ubiquitin-like protein (Ubl) to target-protein lysine residues4. Bacteria encode ancient relatives of E1 and Ubl proteins involved in sulfur metabolism5,6, but these proteins do not mediate Ubl-target conjugation, leaving open the question of whether bacteria can perform ubiquitination-like protein conjugation. Here we demonstrate that a bacterial operon associated with phage defence islands encodes a complete ubiquitination pathway. Two structures of a bacterial E1-E2-Ubl complex reveal striking architectural parallels with canonical eukaryotic ubiquitination machinery. The bacterial E1 possesses an amino-terminal inactive adenylation domain and a carboxy-terminal active adenylation domain with a mobile α-helical insertion containing the catalytic cysteine (CYS domain). One structure reveals a pre-reaction state with the bacterial Ubl C terminus positioned for adenylation, and a second structure mimics an E1-to-E2 transthioesterification state with the E1 CYS domain adjacent to the bound E2. We show that a deubiquitinase in the same pathway preprocesses the bacterial Ubl, exposing its C-terminal glycine for adenylation. Finally, we show that the bacterial E1 and E2 collaborate to conjugate Ubl to target-protein lysine residues. Together, these data reveal that bacteria possess bona fide ubiquitination systems with strong mechanistic and architectural parallels to canonical eukaryotic ubiquitination pathways, suggesting that these pathways arose first in bacteria.

Asunto(s)

Proteínas Bacterianas , Bacteriófagos , Escherichia , Enzimas Activadoras de Ubiquitina , Enzimas Ubiquitina-Conjugadoras , Ubiquitinación , Ubiquitinas , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Bacteriófagos/química , Bacteriófagos/inmunología , Bacteriófagos/metabolismo , Dominio Catalítico , Cristalografía por Rayos X , Cisteína/química , Cisteína/metabolismo , Enzimas Desubicuitinizantes/química , Enzimas Desubicuitinizantes/metabolismo , Escherichia/química , Escherichia/enzimología , Escherichia/inmunología , Escherichia/virología , Evolución Molecular , Lisina/química , Lisina/metabolismo , Modelos Moleculares , Operón/genética , Dominios Proteicos , Enzimas Activadoras de Ubiquitina/metabolismo , Enzimas Activadoras de Ubiquitina/química , Enzimas Ubiquitina-Conjugadoras/metabolismo , Enzimas Ubiquitina-Conjugadoras/química , Ubiquitinas/metabolismo , Ubiquitinas/química , Eucariontes/enzimología , Eucariontes/metabolismo

RESUMEN

Hyaluronidase, an enzyme that degrades hyaluronic acid (HA), is utilized in clinical settings to facilitate drug diffusion, manage extravasation, and address injection-related complications linked to HA-based fillers. In this study, a novel hyaluronate lyase EsHyl8 was cloned, expressed, and characterized from Escherichia sp. A99 of human intestinal origin. This lyase belongs to polysaccharide lyase (PL) family 8, and showed specific activity towards HA. EsHyl8 exhibited optimal degradation at 40 °C and pH 6.0. EsHyl8 exhibited a high activity of 376.32 U/mg among hyaluronidases of human gut microorganisms. EsHyl8 was stable at 37 °C and remained about 70 % of activity after incubation at 37 °C for 24 h, demonstrating excellent thermostability. The activity of EsHyl8 was inhibited by Zn2+, Cu2+, Fe3+, and SDS. EsHyl8 was an endo-type enzyme whose end-product was unsaturated disaccharide. This study enhances our understanding of hyaluronidases from human gut microorganisms.

Asunto(s)

Clonación Molecular , Polisacárido Liasas , Polisacárido Liasas/genética , Polisacárido Liasas/química , Polisacárido Liasas/aislamiento & purificación , Polisacárido Liasas/metabolismo , Humanos , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/aislamiento & purificación , Escherichia/genética , Escherichia/enzimología , Ácido Hialurónico/química , Ácido Hialurónico/metabolismo , Estabilidad de Enzimas , Proteínas Bacterianas/genética , Proteínas Bacterianas/química , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Concentración de Iones de Hidrógeno , Especificidad por Sustrato

RESUMEN

Neonatal sepsis leads to severe morbidity and occasionally death among neonates within the first week following birth, particularly in low- and middle-income countries. Empirical therapy includes antibiotics recommended by WHO. However, these have been ineffective against antimicrobial multidrug-resistant bacterial strains such as Klebsiella spp, Escherichia coli, and Staphylococcus aureus species. To counter this problem, new molecules and alternative sources of compounds with antibacterial activity are sought as options. Actinobacteria, particularly pathogenic strains, have revealed a biotechnological potential still underexplored. This study aimed to determine the presence of biosynthetic gene clusters and the antimicrobial activity of actinobacterial strains isolated from clinical cases against multidrug-resistant bacteria implicated in neonatal sepsis. In total, 15 strains isolated from clinical cases of actinomycetoma were used. PCR screening for the PKS-I, PKS-II, NRPS-I, and NRPS-II biosynthetic systems determined their secondary metabolite-producing potential. The strains were subsequently assayed for antimicrobial activity by the perpendicular cross streak method against Escherichia fergusonii Sec 23, Klebsiella pneumoniae subsp. pneumoniae H1064, Klebsiella variicola H776, Klebsiella oxytoca H793, and Klebsiella pneumoniae subsp. ozaenae H7595, previously classified as multidrug-resistant. Finally, the strains were identified by 16S rRNA gene sequence analysis. It was found that 100% of the actinobacteria had biosynthetic systems. The most frequent biosynthetic system was NRPS-I (100%), and the most frequent combination was NRPS-I and PKS-II (27%). All 15 strains showed antimicrobial activity. The strain with the highest antimicrobial activity was Streptomyces albus 94.1572, as it inhibited the growth of the five multidrug-resistant bacteria evaluated.

Asunto(s)

Antibacterianos , Farmacorresistencia Bacteriana Múltiple , Pruebas de Sensibilidad Microbiana , Sepsis Neonatal , Nocardia , Streptomyces , Antibacterianos/farmacología , Humanos , Recién Nacido , Sepsis Neonatal/microbiología , Nocardia/efectos de los fármacos , Nocardia/genética , Nocardia/aislamiento & purificación , Streptomyces/genética , Klebsiella/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Escherichia/efectos de los fármacos , Reacción en Cadena de la Polimerasa

RESUMEN

The objective of this study was to evaluate the occurrence of E. coli in hunted wild boars in Sardinia (Italy) and to further characterize the isolates with Whole Genome Sequencing to assess the genetic relatedness and the presence of virulence and antimicrobial resistance (AMR) genes. Samples were taken from 66 wild boars between 2020 and 2022 slaughtered in five hunting houses. A total of 181 samples were tested, including 66 samples from mesenteric lymph nodes, 66 samples from colon content and 49 samples from carcass surface. Isolates referable to Escherichia species were detected in all of the wild boars sampled. On a selection of 61 isolates, sequencing was conducted and antimicrobial susceptibility was tested. Among these, three isolates were confirmed to be two Escherichia marmotae (cryptic clade V) and one Escherichia ruysiae (cryptic clade III). E. coli pathotypes identified were UPEC (13 %), ExPEC-UPEC (5.6 %) and ETEC (3.7 %). Moreover, 3/6 E. marmotae isolates had typical ExPEC genes. Genetic similarity was observed in isolates collected from animals slaughtered in the same hunting house; this suggests epidemiological links deriving from the presence of animals infected with closely related strains or the result of cross-contamination. Antimicrobial resistance genes were detected in three non-pathogenic E. coli isolates: one isolate had sul2, tet(B), aph(6)-ld and aph(3″)-lb resistance genes and two had the fosA7 gene. This study confirmed that wild boars can act as reservoirs and spreaders of pathogenic Escherichia species and it provides information for future comparative genomic analysis in wildlife. Although isolates showed a limited resistome, the detection of resistance in non-pathogenic isolates underlines the need to monitor antimicrobial resistance in the wild boar population. To the best of our knowledge, this is the first detection of E. mamotae and E. ruysiae isolates in wild boars in Italy and the presence of this pathogen in wildlife and livestock need to be investigated further.

Asunto(s)

Antibacterianos , Farmacorresistencia Bacteriana , Escherichia coli , Sus scrofa , Animales , Italia , Sus scrofa/microbiología , Porcinos , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Antibacterianos/farmacología , Escherichia/genética , Escherichia/aislamiento & purificación , Escherichia/efectos de los fármacos , Escherichia/patogenicidad , Enfermedades de los Porcinos/microbiología , Enfermedades de los Porcinos/epidemiología , Pruebas de Sensibilidad Microbiana , Virulencia/genética , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/epidemiología , Secuenciación Completa del Genoma

RESUMEN

The rapid and sensitive detection of Escherichia/Shigella genera is crucial for human disease and health. This study introduces a novel series of piezoelectric quartz crystal (SPQC) sensors for detecting Escherichia/Shigella genera. In this innovative biosensor, we propose a new target and novel method for synthesizing long-range DNA. The method relies on the amplification of two DNA probes, referred to as H and P amplification (HPA), resulting in the products of long-range DNA named Sn. The new target was screened from the 16S rRNA gene and utilized as a biomarker. The SPQC sensor operates as follows: the Capture probe is modified on the electrodes. In the presence of a Displace probe and target, the Capture can form a complex with the Displace probe. The resulting complex hybridizes with Sn, bridging the gap between the electrodes. Finally, silver wires are deposited between the electrodes using Sn as a template. This process results in a sensitive response from the SPQC. The detection limit of the SPQC sensor is 1 CFU/mL, and the detection time is within 2 h. This sensor would be of great benefit for food safety monitoring and clinical diagnosis.

Asunto(s)

Técnicas Biosensibles , Escherichia , Técnicas Biosensibles/métodos , Escherichia/genética , ADN Bacteriano/análisis , ADN Bacteriano/genética , ARN Ribosómico 16S/genética , Electrodos , Cuarzo/química , Límite de Detección , Sondas de ADN/química , Humanos , Técnicas de Amplificación de Ácido Nucleico , Técnicas Electroquímicas

RESUMEN

Cadmium (Cd) is a highly toxic metal that frequently contaminates our environment. In this study, the bioflocculant-producing, cadmium-resistant Escherichia fergusonii ZSF-15 was characterized from Paharang drain, Bawa Chak, Faisalabad, Pakistan. The Cd-resistant E. fergusonii was used to determine the bioflocculant production using yeast-peptone-glycerol medium (pH 6.5) supplemented with 50 mg L-1 of Cd. The culture was incubated for 3 days at 37 °C in a rotary shaker at 120 rpm. The fermentation broth was centrifuged at 4000 g for 10 min after the incubation period. The maximum flocculating activity by isolate ZSF-15 was found to be 71.4% after 48 h of incubation. According to the Fourier transform infrared spectroscopy analysis, the bioflocculant produced by strain ZSF-15 was comprised of typical polysaccharide and protein, i.e. hydroxyl, carboxyl, and amino groups. The strain ZSF-15 exhibited bioflocculant activity at range of pH (6-8) and temperature (35-50℃). Maximum flocculation activity (i.e. 71%) was observed at 47℃, whereas 63% flocculation production was observed at pH 8. In the present study, antioxidant enzyme profile of ZSF-15 was also evaluated under cadmium stress. A significant increase in antioxidant enzymes including superoxide dismutase (118%) and ascorbate peroxidase (28%) was observed, whereas contents of catalase (86%), glutathione transferase (13%), and peroxidase (8%) were decreased as compared to control.

Asunto(s)

Antioxidantes , Cadmio , Escherichia , Cadmio/toxicidad , Concentración de Iones de Hidrógeno , Monitoreo del Ambiente , Floculación

RESUMEN

Gut microbiota communicates bidirectionally with the brain through the nervous, immune, and endocrine systems of the gut. In our preliminary study, the fecal microbiota of volunteers with mild cognitive impairment (Fmci) exhibited a higher abundance of Escherichia fergusonii (NK2001), Veillonella infantium (NK2002), and Enterococcus faecium (NK2003) populations compared with those of healthy volunteers. Therefore, we examined the effects of Fmci, NK2001 (gram-negative), NK2002 (gram-negative-like), and NK2003 (gram-positive) on cognitive impairment-like behavior, neuroinflammation, and colitis in mice with or without antibiotics. Fmci transplantation increased cognitive impairment-like behavior, hippocampal tumor necrosis factor (TNF)-α expression, and the size of toll-like receptor (TLR)4+Iba1+, TLR2+Iba1+, and NF-κB+Iba1+ cell populations independent of antibiotic treatment. Oral gavage of NK2001, NK2002, or NK2003, which induced TNF-α expression in Caco-2 cells, significantly increased cognitive impairment-like behavior and hippocampal TNF-α expression and Iba1-positive cell populations and decreased brain-derived neurotrophic factor (BDNF) expression in mice. Celiac vagotomy significantly decreased NK2001- or NK2002-induced cognitive impairment-like behavior and hippocampal Iba1+ cell population and TNF-α expression and increased NK2001- or NK2002-suppressed hippocampal BDNF expression. However, NK2003-induced cognitive impairment-like behavior and hippocampal Iba1+ cell population and TNF-α expression were partially, but not significantly, attenuated by celiac vagotomy. Furthermore, celiac vagotomy did not affect NK2001-, NK2002-, or NK2003-induced lipopolysaccharide (LPS) levels in the blood and feces and TNF-α expression and NF-κB-positive cell population in the colon. In conclusion, LPS-producing NK2001 and NK2002 and LPS-nonproducing NK2003 may induce NF-κB-mediated neuroinflammation through the translocation of byproducts such as LPS and peptidoglycan into the brain through gut-blood/vagus nerve-brain and gut-blood-brain pathways, respectively, resulting in cognitive impairment.

Asunto(s)

Disfunción Cognitiva , Escherichia , Lipopolisacáridos , Veillonella , Humanos , Ratones , Animales , Lipopolisacáridos/farmacología , FN-kappa B/metabolismo , Factor Neurotrófico Derivado del Encéfalo , Factor de Necrosis Tumoral alfa/metabolismo , Enfermedades Neuroinflamatorias , Células CACO-2 , Nervio Vago , Ratones Endogámicos C57BL

RESUMEN

This study is focused on Escherichia spp. isolates resistant to critically important antibiotics (cefotaxime, ciprofloxacin and colistin) among Caspian gull's (Larus cachinnans) chicks nesting in the Nove Mlyny Water Reservoir, Czech Republic. The prevalence of antimicrobial resistance (AMR) in bacteria within wild birds is commonly evaluated using a single sampling event, capturing only a brief and momentary snapshot at a particular location. Therefore, the Caspian gulls in our study were sampled in May 2018 (n = 72) and May 2019 (n = 45), and a water sample was taken from the reservoir (2019). We obtained 197 isolates identified as E. coli by MALDI-TOF MS. A total of 158 representative isolates were whole-genome sequenced, 17 isolates were then reclassified to Escherichia albertii. We observed a higher (86 %; 62/72) occurrence of ESBL/AmpC-producing Escherichia spp. among gulls in 2018 compared to 38 % (17/45) in 2019 (p < 0.00001). The decrease in prevalence was linked to clonal lineage of E. coli ST11893 predominating in 2018 which carried blaCMY-2 and which was not recovered from the gulls in 2019. Oppositely, several Escherichia STs were found in gulls from both years as well as in the water sample including STs commonly recognized as internationally high-risk lineages such as ST10, ST58, ST88, ST117, ST648 or ST744. Phylogenetic analysis of E. coli from EnteroBase from countries where these particular gulls wander revealed that some STs are commonly found in various sources including humans and a portion of them is even closely related (up to 100 SNPs) to our isolates. We demonstrated that the occurrence of AMR in Escherichia can vary greatly in time in synanthropic birds and we detected both, a temporary prevalent lineage and several persistent STs. The close relatedness of isolates from gulls and isolates from EnteroBase highlights the need to further evaluate the risk connected to wandering birds.

Asunto(s)

Antibacterianos , Charadriiformes , Charadriiformes/microbiología , Animales , Antibacterianos/farmacología , República Checa , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Escherichia/efectos de los fármacos , Escherichia/genética , Farmacorresistencia Bacteriana , Estudios Longitudinales

Asunto(s)

Pollos , Escherichia , Carne , Plásmidos , Animales , Plásmidos/genética , Pollos/microbiología , China , Carne/microbiología , Escherichia/genética , Escherichia/efectos de los fármacos , Escherichia/aislamiento & purificación , Antibacterianos/farmacología , Proteínas de Escherichia coli/genética , Farmacorresistencia Bacteriana/genética , Colistina/farmacología , Pruebas de Sensibilidad Microbiana , Microbiología de Alimentos

RESUMEN

Escherichia albertii is an emerging foodborne pathogen that causes diarrhea. E. albertii has been isolated from various foods, including pork and chicken meat, and environmental waters, such as river water. Although many food poisoning cases have been reported, there have been insufficient analyses of bacterial population behaviors in food and environmental water. In this study, we inoculated 2-5 log CFU of E. albertii into 25 g of pork, chicken meat, Japanese rock oyster, Pacific oyster, and 300 mL of well water and seawater at 4°C, 10°C, 20°C, and 30°C, and analyzed the bacterial population behavior in food and environmental water. After 3 days at 4°C, the population of E. albertii strain EA21 and EA24 in foods maintained approximately 4 log CFU/25 g. After 3 days at 10°C, the population of E. albertii strains in pork and oysters maintained approximately 4 log CFU/25 g, and that in chicken meat increased to approximately 5-6 log CFU/25 g. After 2 days at 20°C, E. albertii strains grew to approximately 6-7 log CFU/25 g in pork and chicken meat, and E. albertii strain EA21 but not EA24 grew to 4.5 log CFU/25 g in Japanese rock oyster, E. albertii strain EA21 but not EA24 slightly grew to 3.1 log CFU/25 g in Pacific oyster. After 1 day at 30°C, E. albertii strains grew to approximately 7-8 log CFU/25 g in chicken meat and pork, grew to approximately 4-6 log CFU/25 g in Japanese rock oyster, and 6-7 log CFU/25 g in Pacific oyster. These results suggest that E. albertii survives without growth below 4°C and grew rapidly at 20°C and 30°C in foods, especially in meat. E. albertii strains did not grow in well water and seawater at 4°C, 10°C, 20°C, and 30°C. The population of E. albertii strains in well water and seawater decreased faster at 30°C than at 4°C, 10°C, and 20°C, suggesting that E. albertii has low viability at 30°C in environmental water.

Asunto(s)

Escherichia , Manipulación de Alimentos , Agua , Temperatura , Manipulación de Alimentos/métodos , Carne/microbiología , Microbiología de Alimentos , Recuento de Colonia Microbiana

RESUMEN

Escherichia albertii is an emerging enteropathogen. Although E. albertii-specific detection and isolation methods have been developed, their efficiency on food samples have not yet been systematically studied. To establish a series of effective methods for detecting E. albertii in food, an interlaboratory study was conducted in 11 laboratories using enrichment with modified E. coli broth supplemented with cefixime and tellurite (CT-mEC), real-time PCR assay, and plating on four kinds of selective agars. This study focused on the detection efficiency of an E. albertii-specific real-time PCR assay (EA-rtPCR) and plating on deoxycholate hydrogen sulfide lactose agar (DHL), MacConkey agar (MAC), DHL supplemented with rhamnose and xylose (RX-DHL), and MAC supplemented with rhamnose and xylose (RX-MAC). Chicken and bean sprout samples were inoculated with E. albertii either at 17.7 CFU/25 g (low inoculation level) or 88.5 CFU/25 g (high inoculation level), and uninoculated samples were used as controls. The sensitivity of EA-rtPCR was 1.000 for chicken and bean sprout samples inoculated with E. albertii at low and high inoculation levels. The Ct values of bean sprout samples were higher than those of the chicken samples. Analysis of microbial distribution by 16S rRNA gene amplicon sequencing in enriched cultures of bean sprout samples showed that approximately >96 % of the population comprised unidentified genus of family Enterobacteriaceae and genus Acinetobacter in samples which E. albertii was not isolated. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a high inoculation level of E. albertii was 1.000 and 0.848-0.970, respectively. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a low inoculation level of E. albertii was 0.939-1.000 and 0.515-0.727, respectively. The E. albertii-positive rate in all colonies isolated in this study was 89-90 % in RX-DHL and RX-MAC, and 64 and 44 % in DHL and MAC, respectively. Therefore, the sensitivity of RX-supplemented agar was higher than that of the agars without these sugars. Using a combination of enrichment in CT-mEC and E. albertii isolation on selective agars supplemented with RX, E. albertii at an inoculation level of over 17.5 CFU/25 g of food was detected with a sensitivity of 1.000 and 0.667-0.727 in chicken and bean sprouts, respectively. Therefore, screening for E. albertii-specific genes using EA-rtPCR followed by isolation with RX-DHL or RX-MAC is an efficient method for E. albertii detection in food.

Asunto(s)

Escherichia coli , Escherichia , Xilosa , Agar , Reacción en Cadena en Tiempo Real de la Polimerasa , ARN Ribosómico 16S , Ramnosa , Medios de Cultivo , Carne , Microbiología de Alimentos , Lactosa

RESUMEN

Antibiotic resistance is a growing global concern, with many ecological niches showing a high abundance of antibiotic resistance genes (ARGs), including the human gut. With increasing indications of ARGs in infants, this study aims to investigate the gut resistome profile during early life at a wider geographic level. To achieve this objective, we utilized stool samples data from 26 studies involving subjects aged up to 3 years from different geographical locations. The 32,277 Metagenome Assembled Genomes (MAGs) previously generated from shotgun sequencing reads from these studies were used for resistome analysis using RGI with the CARD database. This analysis showed that the distribution of ARGs across the countries in our study differed in alpha diversity and compositionally. In particular, the abundance of ARGs was found to vary by socioeconomic status and healthcare access and quality (HAQ) index. Surprisingly, countries having lower socioeconomic status and HAQ indices showed lower ARG abundance, which was contradictory to previous reports. Gram-negative genera, including Escherichia, Enterobacter, Citrobacter, and Klebsiella harbored a particularly rich set of ARGs, which included antibiotics that belong to the Reserve, Access or Watch category, such as glycopeptides, fluoroquinolones, sulfonamides, macrolides, and tetracyclines. We showed that ARG abundance exponentially decreased with time during the first 3 years of life. Many highly ARG-abundant species including Escherichia, Klebsiella, Citrobacter species that we observed are well-known pathobionts found in the infant gut in early life. High abundance of these species and a diverse range of ARGs in their genomes point toward the infant gut, acting as an ARG reservoir. This is a concern and further studies are needed to examine the causal effect and its consequences on long-term health.

Asunto(s)

Microbioma Gastrointestinal , Genes Bacterianos , Lactante , Humanos , Anciano , Microbioma Gastrointestinal/genética , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Escherichia/genética , Clase Social

RESUMEN

This study aimed to reveal the prevalence of heat-labile enterotoxin (LT) gene-positive Escherichia fergusonii in retail chicken meat and genetically characterize these strains. E. fergusonii harboring LT gene was isolated from 6 out of 60 (10%) retail chicken samples in Okinawa, Japan. Whole-genome sequencing analysis revealed that LT gene-positive E. fergusonii from chicken meat and feces contain an IncFII plasmid harboring elt1AB, and suggested to spread clonally to retail chicken through fecal contamination. Additionally, it was found that these strains harbor multidrug-resistant genes on their plasmids. Their pathogenicity and continuous monitoring are required for confirmation.

Asunto(s)

Enterotoxinas , Escherichia coli , Escherichia , Animales , Escherichia coli/genética , Enterotoxinas/genética , Pollos , Japón , Calor , Plásmidos/genética , Carne , Antibacterianos/farmacología , Farmacorresistencia Bacteriana

RESUMEN

Lytic bacteriophages are promising biocontrol agents against pathogenic bacteria for food and therapeutic applications. Investigating the feasibility of combining phage and physical lethal agents, such as heat, as an effective hurdle combination could lead to beneficial applications. The current research was initiated to compare the thermal inactivation kinetics of a lytic phage (Escherichia phage OSYSP) and its host (Shiga toxin-producing Escherichia coli O157:H7 EDL933), considering they have different critical thermal targets in their structures. To provide a basis for comparison, thermal inactivation kinetics were determined on suspensions of these agents in buffered peptone water using a thermally controlled circulating water bath. Results showed that the bacteriophage virions have a remarkable heat resistance (p < 0.05) compared to their host cells. The D-values of the populations of phage (PFU/mL) and EDL933 strain (CFU/mL) were 166.7 and 7.3 min at 55°C, compared to 44.4 and 0.3 min at 60°C, respectively. Additionally, D-values were significantly (p < 0.05) more influenced by temperature changes in the case of E. coli O157:H7 EDL933 (z-value 3.7°C) compared to that for phage OSYSP (z-value 7.7°C). When the phage suspension was heat-treated in a thermal cycler instead of a water bath, no significant differences between the two treatment procedures (p > 0.05) in estimating virus D- and z-values were observed. Based on these findings, it may be feasible to combine phage OSYSP with mild heat during processing of food to selectively inactivate E. coli O157:H7 EDL933 and subsequently maintain product safety during storage by the surviving phage population; however, the feasibility of this application needs to be investigated. Additionally, the relatively heat-resistant phage OSYSP could qualify as a biological indicator to validate thermal treatments of minimally processed foods in which E. coli O157:H7 EDL933 is the pathogen-of-concern.

Asunto(s)

Bacteriófagos , Escherichia coli O157 , Bacteriófagos/fisiología , Escherichia , Escherichia coli O157/fisiología , Microbiología de Alimentos , Cinética , Agua

RESUMEN

Escherichia coli is one of the most common causes of urinary tract infections. However, a recent upsurge in antibiotic resistance among uropathogenic E. coli (UPEC) strains has provided an impetus to explore alternative antibacterial compounds to encounter this major issue. In this study, a lytic phage against multi-drug-resistant (MDR) UPEC strains was isolated and characterized. The isolated Escherichia phage FS2B of class Caudoviricetes exhibited high lytic activity, high burst size, and a small adsorption and latent time. The phage also exhibited a broad host range and inactivated 69.8% of the collected clinical, and 64.8% of the identified MDR UPEC strains. Further, whole genome sequencing revealed that the phage was 77,407 bp long, having a dsDNA with 124 coding regions. Annotation studies confirmed that the phage carried all the genes associated with lytic life cycle and all lysogeny related genes were absent in the genome. Further, synergism studies of the phage FS2B with antibiotics demonstrated a positive synergistic association among them. The present study therefore concluded that the phage FS2B possesses an immense potential to serve as a novel candidate for treatment of MDR UPEC strains.

Asunto(s)

Bacteriófagos , Infecciones por Escherichia coli , Infecciones Urinarias , Escherichia coli Uropatógena , Humanos , Escherichia coli Uropatógena/genética , Bacteriófagos/genética , Escherichia , Infecciones Urinarias/microbiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Infecciones por Escherichia coli/microbiología

RESUMEN

Escherichia albertii has increasingly been recognized as an important emerging zoonotic enteropathogen. Raccoon is shown to be one of the most vital reservoirs of this pathogen. E. albertii has been detected in 993 (62%) out of 1,606 wild raccoons in Osaka, Japan from 2017 to 2020 by Eacdt-PCR. The detection rate of E. albertii was increased from May to December (winter) and gradually decreased from January to April (spring). Furthermore, we could isolate E. albertii from 30% (196/664) of Eacdt-PCR positive samples and the monthly isolation rate seems to correlate with its detection rate. These data indicate that there is a seasonality regarding the prevalence of E. albertii in wild raccoon being higher in winter and lower in spring.

Asunto(s)

Escherichia , Mapaches , Animales , Japón/epidemiología , Estaciones del Año

RESUMEN

The gut microbiota is closely related to the development of sepsis. The aim of this study was to explore changes in the gut microbiota and gut metabolism, as well as potential relationships between the gut microbiota and environmental factors in the early stages of sepsis. Fecal samples were collected from 10 septic patients on the first and third days following diagnosis in this study. The results showed that in the early stages of sepsis, the gut microbiota is dominated by microorganisms that are tightly associated with inflammation, such as Escherichia-Shigella, Enterococcus, Enterobacteriaceae, and Streptococcus. On sepsis day 3 compared to day 1, there was a significant decrease in Lactobacillus and Bacteroides and a significant increase in Enterobacteriaceae, Streptococcus, and Parabacteroides. Culturomica_massiliensis, Prevotella_7 spp., Prevotellaceae, and Pediococcus showed significant differences in abundance on sepsis day 1, but not on sepsis day 3. Additionally, 2-keto-isovaleric acid 1 and 4-hydroxy-6-methyl-2-pyrone metabolites significantly increased on sepsis day 3 compared to day 1. Prevotella_7 spp. was positively correlated with phosphate and negatively correlated with 2-keto-isovaleric acid 1 and 3-hydroxypropionic acid 1, while Prevotella_9 spp. was positively correlated with sequential organ failure assessment score, procalcitonin and intensive care unit stay time. In conclusion, the gut microbiota and metabolites are altered during sepsis, with some beneficial microorganisms decreasing and some pathogenic microorganisms increasing. Furthermore, Prevotellaceae members may play different roles in the intestinal tract, with Prevotella_7 spp. potentially possessing beneficial health properties and Prevotella_9 spp. potentially playing a promoting role in sepsis.(AU)

Asunto(s)

Humanos , Masculino , Femenino , Sepsis , Microbioma Gastrointestinal , Streptococcus/metabolismo , Enterobacteriaceae/metabolismo , Enterococcus , Escherichia/metabolismo , Microbiología , Técnicas Microbiológicas , Metabolómica , Heces/microbiología , ARN Ribosómico

RESUMEN

Feed quality influences insect cannibalistic behavior and gut microbial communities. In the present study, Spodoptera exigua larvae were fed six different artificial diets, and one of these diets (Diet 3) delayed larval cannibalistic behavior and reduced the cannibalism ratio after ingestion. Diet 3-fed larvae had the highest gut bacterial load (1.396 ± 0.556 × 1014 bacteria/mg gut), whereas Diet 2-fed larvae had the lowest gut bacterial load (3.076 ± 1.368 × 1012 bacteria/mg gut). The gut bacterial composition and diversity of different diet-fed S. exigua larvae varied according to the 16S rRNA gene sequence analysis. Enterobacteriaceae was specific to the Diet 3-fed larval gut. Fifteen culturable bacterial isolates were obtained from the midgut of Diet 3-fed larvae. Of these, ten belonged to Escherichia sp. After administration with Diet 1- or 2-fed S. exigua larvae, two bacterial isolates (SePC-12 and -37) delayed cannibalistic behavior in both tested larval groups. Diet 2-fed larvae had the lowest Juvenile hormone (JH) concentration and were more aggressive against intraspecific predation. However, SePC-12 loading increased the JH hormone levels in Diet 2-fed larvae and inhibited their cannibalism. Bacteria in the larval midgut are involved in the stabilization of JH levels, thereby regulating host larval cannibalistic behavior.

Asunto(s)

Canibalismo , Escherichia , Animales , Spodoptera/genética , Larva/fisiología , ARN Ribosómico 16S/genética , Bacterias