RESUMEN

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen associated with severe disease. Cattle are recognized as the primary animal reservoir of STEC. This study reports the occurrence and characterization of STEC from dairy cows and evaluates the inhibition of adherence by cattle anti-STEC antibodies to the HEp-2 cell. From 151 samples, 30% (n = 45) were positive for stx by PCR screening (25.21% of dairy cows and 46.8% of growing calves). From these positive samples, 17 STEC isolates were characterized. In dairy cows, 3 out of 17 samples carried stx2, 3 out of 17 possessed stx1, and 2 out of 17 carried stx1/stx2. In growing cows, 8 out of 17 samples carried stx1 and 1 out of 17 carried stx1/stx2. Other virulence factors such as ehxA, saa, iha, cah, and eae were detected. The strains were typed into 3 E. coli O groups (O26, O91, and O130). The analysis of the HEp-2 adherence assays indicated that all serum from both cattle categories presented high levels of inhibition of adherence. Considering the severity of the symptoms caused by STEC in humans, searching for factors influencing the colonization of STEC in cattle would help identify strategies to avoid transmission and STEC infection.

Asunto(s)

Enfermedades de los Bovinos , Infecciones por Escherichia coli , Escherichia coli Shiga-Toxigénica , Animales , Bovinos , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/inmunología , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/microbiología , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/inmunología , Femenino , Anticuerpos Antibacterianos/sangre , Adhesión Bacteriana , Humanos

RESUMEN

The current study aimed to detect virulence, hetero-pathogenicity, and hybridization genes in Escherichia coli strains, previously isolated from cloacal swabs in commercial breeding psittacines and zoological collections, via multiplex PCR. A total of 68 strains of E. coli, previously isolated from psittacines in zoos and commercial breeding facilities in Ceará, Brazil, were assessed for the presence of the following genes and/or probes: eae, bfpA (EPEC - Enteropathogenic E. coli), CVD432 (EAEC - Enteroaggregative E. coli); LT gene and ST gene (ETEC - Enterotoxigenic E. coli); ipaH (EIEC - Enteroinvasive E. coli); stx1 and stx2 (STEC - Shiga toxin-producing E. coli); iroN, ompT, hlyF, iss, and iutA (APEC - Avian pathogenic E. coli). Of the 68 E. coli strains analyzed, 61 (98.7 %) were positive for the following genes and/or probes: Stx1 (61/98.7 %), ST gene (54/79.4 %), CVD432 (49/72 %), bfpA (44/64.7 %), eae (42/61.8 %), Stx2 (41/60.3 %), ipaH (34/50 %), LT gene (33/48.5 %), iroN (21/30.9 %), hlyF (11/6.2 %), iss (06/8.8 %) and iutA (06/8.8 %). The following diarrheagenic pathotypes were identified: 66 (97 %) from STEC, 49 (72 %) from EAEC, 35 (52 %) from EIEC, 25 (37 %) from ETEC, and one (1.5 %) from EPEC. Regarding hetero-pathogenicity, 50 (74 %) heterogeneous strains were identified. Positivity for APEC was seen in four (6 %) strains, all characterized as pathogenic hybrids. This study describes significant associations of virulence factors in E. coli strains DEC/DEC and DEC/APEC, which were isolated from psittacines and may be potentially harmful to One Health.

Asunto(s)

Animales de Zoológico , Enfermedades de las Aves , Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli , Factores de Virulencia , Animales , Brasil , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Animales de Zoológico/microbiología , Enfermedades de las Aves/microbiología , Escherichia coli/genética , Escherichia coli/patogenicidad , Escherichia coli/aislamiento & purificación , Escherichia coli/clasificación , Proteínas de Escherichia coli/genética , Factores de Virulencia/genética , Virulencia/genética , Escherichia coli Enteropatógena/genética , Escherichia coli Enteropatógena/patogenicidad , Escherichia coli Enteropatógena/aislamiento & purificación , Escherichia coli Enteropatógena/clasificación , Reacción en Cadena de la Polimerasa Multiplex , Psittaciformes/microbiología , Cloaca/microbiología , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Escherichia coli Shiga-Toxigénica/patogenicidad , Escherichia coli Shiga-Toxigénica/clasificación , Escherichia coli Enterotoxigénica/genética , Escherichia coli Enterotoxigénica/patogenicidad , Escherichia coli Enterotoxigénica/aislamiento & purificación , Escherichia coli Enterotoxigénica/clasificación

RESUMEN

The indiscriminate use of antimicrobials has led to the emergence of resistant bacteria, especially pathogenic strains of Escherichia coli, which are associated with diseases in animals and humans. The aim of the present study was to characterize E. coli isolates in calves with regards to the presence of virulence genes and investigate the resistance of the isolates to different antimicrobials. Between 2021 and 2023, 456 fecal samples were collected from calves in the Pantanal and Cerrado biomes of the state of Mato Grosso do Sul, Brazil. All samples were subjected to microbiological analysis and disc diffusion antibiogram testing. The polymerase chain reaction method was used to detect virulence genes. Bacterial growth was found in 451 of the 456 samples and biochemically identified as Escherichia coli. All 451 isolates (100 %) exhibited some phenotypic resistance to antimicrobials and 67.62 % exhibited multidrug resistance. The frequency of multidrug-resistant isolates in the Cerrado biome was significantly higher than that in the Pantanal biome (p = 0.0001). In the Cerrado, the most common pathotype was Shiga toxin-producing Escherichia coli (STEC) (28 %), followed by toxigenic Escherichia coli (ETEC) (11 %), enterohemorrhagic Escherichia coli (EHEC) (8 %) and enteropathogenic Escherichia coli (EPEC) (2 %). In most cases, the concomitant occurrence of pathotypes was more common, the most frequent of which were ETEC + STEC (33 %), ETEC + EHEC (15 %) and ETEC + EPEC (3 %). The STEC pathotype (30 %) was also found more frequently in the Pantanal, followed by EHEC (12 %), ETEC (9 %) and EPEC (6 %). The STEC pathotype had a significantly higher frequency of multidrug resistance (p = 0.0486) compared to the other pathotypes identified. The frequency of resistance was lower in strains from the Pantanal biome compared to those from the Cerrado biome. Although some factors are discussed in this paper, it is necessary to clarify the reasons for this difference and the possible impacts of these findings on both animal and human health in the region.

Asunto(s)

Antibacterianos , Enfermedades de los Bovinos , Farmacorresistencia Bacteriana Múltiple , Infecciones por Escherichia coli , Escherichia coli , Heces , Pruebas de Sensibilidad Microbiana , Factores de Virulencia , Animales , Bovinos , Brasil , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/epidemiología , Heces/microbiología , Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/epidemiología , Factores de Virulencia/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/efectos de los fármacos , Escherichia coli Enterohemorrágica/genética , Escherichia coli Enterohemorrágica/aislamiento & purificación , Escherichia coli Enterohemorrágica/efectos de los fármacos , Escherichia coli Enterotoxigénica/efectos de los fármacos , Escherichia coli Enterotoxigénica/genética , Escherichia coli Enterotoxigénica/aislamiento & purificación , Proteínas de Escherichia coli/genética

RESUMEN

Shiga toxigenic E. coli are important foodborne zoonotic pathogens. The present study was envisaged to standardize loop-mediated isothermal amplification assays targeting stx1 and stx2 genes for rapid and visual detection of STEC and compare its sensitivity with PCR. The study also assessed the effect of short enrichment on the detection limit of LAMP and PCR. The developed LAMP assays were found to be highly specific. Analytical sensitivity of LAMP was 94 fg/µLand 25.8 fg/µL for stx-1 and stx-2 while LOD of 5 CFU/g of carabeef was measured after 6-12 h enrichment. The study highlights the importance of short (6-12 h) enrichment for improving the sensitivity of LAMP. The entire detection protocol could be performed within 9 h yielding results on the same day. The developed LAMP assays proved to be a handy and cost-effective alternative for screening STEC contamination in meat.

Asunto(s)

Carne , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Sensibilidad y Especificidad , Escherichia coli Shiga-Toxigénica , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Animales , Técnicas de Diagnóstico Molecular/métodos , Carne/microbiología , Microbiología de Alimentos/métodos , Toxina Shiga I/genética , Toxina Shiga II/genética , Contaminación de Alimentos/análisis

RESUMEN

Although it has been hypothesized that the acquisition of plasmids-especially those bearing virulence factors and antimicrobial resistance genes-increases the energetic burden and reduces the fitness of a bacterium in general, some results have challenged this view, showing little or no effect on fitness after plasmid acquisition, which may lead to change in the view that there are evolutionary barriers for a wide spread of such plasmids among bacteria. Here, to evaluate the fitness impact of plasmid-encoded antibiotic resistance and virulence genes, plasmids from O26:H11, O111:H8, and O118:H16 Shiga toxin-producing Escherichia coli (STEC) human and bovine isolates were transferred to the non-virulent E. coli HS and K-12 MG1655 strains. Sequencing and PCR were used to characterize plasmids, and to identify the presence of antimicrobial resistance and/or virulence genes. The fitness impact of plasmids encoding virulence and antimicrobial resistance upon bacterial hosts was determined by pairwise growth competition. Plasmid profile analysis showed that STEC strains carried one or more high and low molecular weight plasmids belonging to the B/O, F, I, K, P, Q, and/or X incompatibility groups encoding virulence genes (SPATE-encoding genes) and/or antimicrobial resistance genes (aadA1, strAB, tetA, and/or tetB). Competition experiments demonstrated that the biological cost of carriage of these plasmids by the commensal E. coli strain HS or the laboratory strain E. coli K-12 MG1655 was low or non-existent, ranging from - 4.7 to 5.2% per generation. This suggests that there are few biological barriers-or, alternatively, it suggests that there are biological barriers that we were not able to measure in this competition model-against the spread of plasmid encoding virulence and resistance genes from STEC to other, less pathogenic E. coli strains. Thus, our results, in opposition to a common view, suggest that the acquisition of plasmids does not significantly affect the bacteria fitness and, therefore, the theorized plasmid burden would not be a significant barrier for plasmid spread.

Asunto(s)

Infecciones por Escherichia coli , Plásmidos , Escherichia coli Shiga-Toxigénica , Factores de Virulencia , Plásmidos/genética , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/efectos de los fármacos , Animales , Bovinos , Factores de Virulencia/genética , Humanos , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Virulencia/genética , Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Aptitud Genética , Farmacorresistencia Bacteriana/genética , Antibacterianos/farmacología

RESUMEN

Shiga-toxin-producing Escherichia coli (STEC) is associated with diarrhea and hemolytic uremic syndrome (HUS). STEC infections in Costa Rica are rarely reported in children. We gathered all the records of STEC infections in children documented at the National Children's Hospital, a tertiary referral hospital, from 2015 to 2020. Clinical, microbiological, and genomic information were analyzed and summarized. A total of 3,768 diarrheal episodes were reviewed. Among them, 31 STEC were characterized (29 fecal, 1 urine, and 1 bloodstream infection). The prevalence of diarrheal disease due to STEC was estimated at 0.8% (n = 29/3,768), and HUS development was 6.4% (n = 2/31). The stx1 gene was found in 77% (n = 24/31) of STEC strains. In silico genomic predictions revealed a predominant prevalence of serotype O118/O152:H2, accompanied by a cluster exhibiting allele differences ranging from 33 to 8, using a core-genome multilocus sequence typing (cgMLST) approach. This is the first study using a genomic approach for STEC infections in Costa Rica.IMPORTANCEThis study provides a comprehensive description of clinical, microbiological, genomic, and demographic data from patients who attended the only pediatric hospital in Costa Rica with Shiga-toxin-producing Escherichia coli (STEC) infections. Despite the low prevalence of STEC infections, we found a predominant serotype O118/O152:H2, highlighting the pivotal role of genomics in understanding the epidemiology of public health threats such as STEC. Employing a genomic approach for this pathogen for the first time in Costa Rica, we identified a higher prevalence of STEC in children under 2 years old, especially those with gastrointestinal comorbidities, residing in densely populated regions. Limitations such as potential geographic bias and lack of strains due to direct molecular diagnostics are acknowledged, emphasizing the need for continued surveillance to uncover the true extent of circulating serotypes and potential outbreaks in Costa Rica.

Asunto(s)

Infecciones por Escherichia coli , Síndrome Hemolítico-Urémico , Escherichia coli Shiga-Toxigénica , Niño , Humanos , Lactante , Escherichia coli Shiga-Toxigénica/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Estudios Retrospectivos , Centros de Atención Terciaria , Costa Rica/epidemiología , Diarrea/epidemiología , Diarrea/microbiología , Síndrome Hemolítico-Urémico/complicaciones , Síndrome Hemolítico-Urémico/epidemiología , Síndrome Hemolítico-Urémico/microbiología , Genómica

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) are recognized as being responsible for many cases of foodborne diseases worldwide. Cattle are the main reservoir of STEC, shedding the microorganisms in their feces. The serogroup STEC O91 has been associated with hemorrhagic colitis and hemolytic uremic syndrome. Locus of Adhesion and Autoaggregation (LAA) and its hes gene are related to the pathogenicity of STEC and the ability to form biofilms. Considering the frequent isolation of STEC O91, the biofilm-forming ability, and the possible role of hes in the pathogenicity of STEC, we propose to evaluate the ability of STEC to form biofilms and to evaluate the expression of hes before and after of biofilm formation. All strains were classified as strong biofilm-forming. The hes expression showed variability between strains before and after biofilm formation, and this may be due to other genes carried by each strain. This study is the first to report the relationship between biofilm formation, and hes expression and proposes that the analysis and diagnosis of LAA, especially hes as STEC O91 virulence factors, could elucidate these unknown mechanisms. Considering that there is no specific treatment for HUS, only supportive care, it is necessary to know the survival and virulence mechanisms of STEC O91.

Asunto(s)

Biopelículas , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Biopelículas/crecimiento & desarrollo , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/fisiología , Escherichia coli Shiga-Toxigénica/patogenicidad , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica , Animales , Bovinos , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/microbiología , Transcripción Genética

RESUMEN

OBJECTIVES: Shiga toxin-producing Escherichia coli strains LAA-positive are important cause of human infection. The capability to adhere to epithelial cells is a key virulence trait, and genes codified in LAA pathogenicity island could be involved in the adhesion during the pathogenesis of LAA-positive STEC strains. Thus, our objectives were to compare hes-negative and hes-positive STEC strains in their adherence capability to epithelial cells (HEp-2) and to evaluate the expression levels of the hes, iha, and tpsA in the bacteria adhered and non-adhered to HEp-2 cells. These genes are encoded in LAA, and are virulence factors that participate in adhesion and autoaggregation. RESULTS: We could not observe differences between the adhesion of strains but also in the expression level of of hes, iha, and tpsA. Genes encoded in LAA contribute to the adhesion phenotype though the expression of STEC adhesins is a coordinated event that depends not only the strain but also on the environment as well as its genetic background. Therefore, the results of this study suggest that LAA ,the most prevalent PAI among LEE-negative STEC strains, plays a role in pathogenesis.

Asunto(s)

Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Humanos , Adhesinas Bacterianas/genética , Células Epiteliales/microbiología , Infecciones por Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Línea Celular

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) is an important pathogen with public health implications, including its potential association with vegetables. In this study, we investigated the presence of STEC in vegetables obtained from organic producers located in São Paulo city, Brazil. As part of a routine surveillance study conducted over (years of isolation), a total of 200 samples of organic vegetables were screened using biochemical and PCR methods. Among the vegetable samples tested, 30 (15%) were positive for non-Shiga toxin-producing E. coli. While no STEC was detected in the organic vegetables in this study, the presence of non-STEC in vegetables raises concerns about the lack of proper hygiene practices during vegetable handling. This contamination represents a public health risk, particularly considering that these isolates can still be pathogenic, and vegetables are often consumed raw. To address this important issue, continuous monitoring of these farms is recommended to ensure the quality and safety of organic vegetables produced for both domestic consumption and exportation.

Asunto(s)

Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Humanos , Escherichia coli Shiga-Toxigénica/genética , Brasil , Proteínas de Escherichia coli/genética , Reacción en Cadena de la Polimerasa , Infecciones por Escherichia coli/microbiología

RESUMEN

Foodborne diseases are characterized by conditions that can induce symptomatic illnesses in their carriers, and therefore represent a serious problem. They are important conditions from a clinical and epidemiological point of view, and are associated with the occurrence of serious public health problems, with a strong impact on morbidity and mortality. The Escherichia coli (E. coli) is an enterobacterium associated with enteric conditions of variable intensity and which are accompanied by blood. The transmission routes are mainly based on the consumption of contaminated food and water sources. Shiga toxin-producing E. coli (STEC) are considered a serogroup of E. coli, are capable of producing Shiga-type toxins (Stx 1 and Stx 2) and the O157:H7 strain is one of the best-known serotypes. The early detection of this pathogen is very important, especially due to the capacity of contamination of carcasses destined for food consumption and supply of productive markets. Sanitary protocols must be developed and constantly reviewed in order to prevent/control the presence of the pathogen.

Asunto(s)

Infecciones por Escherichia coli , Escherichia coli O157 , Proteínas de Escherichia coli , Enfermedades Transmitidas por los Alimentos , Escherichia coli Shiga-Toxigénica , Animales , Bovinos , Escherichia coli O157/genética , Escherichia coli Shiga-Toxigénica/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Infecciones por Escherichia coli/microbiología , Enfermedades Transmitidas por los Alimentos/microbiología

RESUMEN

In Argentina, hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli (STEC-HUS) infection is endemic, and reliable data about prevalence and risk factors have been available since 2000. However, information about STEC-associated bloody diarrhea (BD) is limited. A prospective study was performed during the period October 2018-June 2019 in seven tertiary-hospitals and 18 referral units from different regions, aiming to determine (i) the frequency of STEC-positive BD cases in 714 children aged 1-9 years of age and (ii) the rate of progression of bloody diarrhea to HUS. The number and regional distribution of STEC-HUS cases in the same hospitals and during the same period were also assessed. Twenty-nine (4.1%) of the BD patients were STEC-positive, as determined by the Shiga Toxin Quik Chek (STQC) test and/or the multiplex polymerase chain reaction (mPCR) assay. The highest frequencies were found in the Southern region (Neuquén, 8.7%; Bahía Blanca, 7.9%), in children between 12 and 23 month of age (8.8%), during summertime. Four (13.8%) cases progressed to HUS, three to nine days after diarrhea onset. Twenty-seven STEC-HUS in children under 5 years of age (77.8%) were enrolled, 51.9% were female; 44% were Stx-positive by STQC and all by mPCR. The most common serotypes were O157:H7 and O145:H28 and the prevalent genotypes, both among BD and HUS cases, were stx2a-only or -associated. Considering the endemic behavior of HUS and its high incidence, these data show that the rate of STEC-positive cases is low among BD patients. However, the early recognition of STEC-positive cases is important for patient monitoring and initiation of supportive treatment.

Asunto(s)

Infecciones por Escherichia coli , Síndrome Hemolítico-Urémico , Escherichia coli Shiga-Toxigénica , Niño , Humanos , Femenino , Preescolar , Lactante , Masculino , Escherichia coli Shiga-Toxigénica/genética , Infecciones por Escherichia coli/epidemiología , Argentina/epidemiología , Estudios Prospectivos , Diarrea/epidemiología , Síndrome Hemolítico-Urémico/epidemiología

RESUMEN

Antimicrobial-resistant Escherichia coli strains have been circulating in various sectors and can be cross-transferred between them. Among pathogenic E. coli strains, Shiga toxin-producing E. coli (STEC) and hybrid pathogenic E. coli (HyPEC) emerged as responsible for outbreaks worldwide. As bovine are reservoir of STEC strains, these pathogens primarily spread to food products, exposing humans to risk. Therefore, this study aimed to characterize antimicrobial-resistant and potentially pathogenic E. coli strains from fecal samples of dairy cattle. In this regard, most E. coli strains (phylogenetic groups A, B1, B2, and E) were resistant to ß-lactams and non-ß-lactams and were classified as multidrug-resistant (MDR). Antimicrobial resistance genes (ARGs) related to multidrug resistance profiles were detected. Furthermore, mutations in fluoroquinolone and colistin resistance determinants were also identified, highlighting the deleterious mutation His152Gln in PmrB that may have contributed to the high level (> 64 mg/L) of colistin resistance. Virulence genes of diarrheagenic and extraintestinal pathogenic E. coli (ExPEC) pathotypes were shared among strains and even within the same strain, evidencing the presence of HyPEC (i.e., ExPEC/STEC), which were assigned as unusual B2-ST126-H3 and B1-ST3695-H31. These findings provide phenotypic and molecular data of MDR, ARGs-producing, and potentially pathogenic E. coli strains in dairy cattle, contributing to the monitoring of antimicrobial resistance and pathogens in healthy animals and alerting to potential bovine-associated zoonotic infections.

Asunto(s)

Antiinfecciosos , Enfermedades de los Bovinos , Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Humanos , Animales , Bovinos , Escherichia coli Shiga-Toxigénica/genética , Infecciones por Escherichia coli/veterinaria , Colistina , Filogenia , Proteínas de Escherichia coli/genética , Enfermedades de los Bovinos/epidemiología

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens causing severe diseases. The ability of STEC to produce disease is associated with Shiga toxin (Stx) production. We investigated the occurrence of STEC on bovine and pork carcasses and walls of trucks where they were transported, and we characterized virulence genes and serotypes of STEC strains. We compared the whole genomic sequencing of a STEC O157:H7 strain isolated from a bovine carcass in this work and a STEC O157:H7 strain isolated from a child with HUS, both isolated in 2019. We studied the relationship between these isolates and others collected in the database. The results show a 40% of STEC and two different serogroups were identified (O130 and O157). STEC O157:H7 were isolated from bovine carcasses and harbored stx2, eae, ehxA, katP, espP, stcE, ECSP_0242/1773/2687/2870/2872/3286/3620 and were classified as lineage I/II. In STEC non-O157 isolates, three isolates were isolated from bovine carcasses and harbored the serogroup O130 and one strain isolated from pork carcasses was O-non-typeable. All STEC non-O157 harbored sxt1 gene. The analysis from the whole genome showed that both STEC O157:H7 strains belonged to the hypervirulent clade 8, ST11, phylogroup E, carried the allele tir 255 T > A T, and they were not clonal. The analysis of information allows us to conclude that the STEC strains circulate in pork and bovine carcasses arriving in transport. This situation represents a risk for the consumers and the need to implement an integrated STEC control in the food chain.

Asunto(s)

Infecciones por Escherichia coli , Escherichia coli O157 , Proteínas de Escherichia coli , Carne de Cerdo , Carne Roja , Escherichia coli Shiga-Toxigénica , Niño , Animales , Bovinos , Humanos , Porcinos , Escherichia coli Shiga-Toxigénica/genética , Proteínas de Escherichia coli/genética , Escherichia coli O157/genética , Infecciones por Escherichia coli/veterinaria

RESUMEN

AIMS: Characterize Escherichia coli and E. coli -producing (STEC) isolates from Brazilian beef to determine heat resistance and the presence of the transmissible locus of stress tolerance (tLST). METHODS AND RESULTS: Twenty-two STEC previously isolated from beef and characterized as STEC by PCR were subjected to different heat survival challenges (60°C and 71°C). Furthermore, the three tLST-positive isolates and one tLST-negative isolate by PCR were selected for WGS analysis. Phenotypic results indicated that 3/22 (13.64%) were heat resistant, 12/22 (54.54%) were moderately resistant, and 7/22 (31.82%) were sensitive to heat treatments. WGS analyses showed that three isolates with heat resistance showed tLST with up to 80% and 42% of similarity by BLAST analysis, with the major tLST genes being responsible for the homeostasis module. However, WGS showed the absence of stx genes associated with tLST-positive isolates, albeit with virulence and resistance genes found in extraintestinal pathogenic E. coli (ExPEC). CONCLUSION: Our findings demonstrate the presence of heat-resistant E. coli as well as confirm some tLST genes in E. coli isolated from Brazilian beef.

Asunto(s)

Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Animales , Bovinos , Calor , Brasil , Proteínas de Escherichia coli/genética , Escherichia coli Shiga-Toxigénica/genética , Factores de Virulencia/genética , Genómica

RESUMEN

BACKGROUND: Hemolytic uremic syndrome secondary to Shiga-toxin-producing Escherichia coli infection (STEC-HUS) generally shows a favorable outcome. Few cases develop extra-renal complications, since neurological involvement is an important cause of morbidity and mortality. The role of complement in STEC-HUS has been recently highlighted, and the use of eculizumab in severe cases has been communicated. HUS results from environmental and genetic factors, but the simultaneous occurrence of STEC and complement mutations remains undetermined. METHODS: A pediatric case with severe STEC-HUS carrying CFH mutations, with favorable response to eculizumab is analyzed. RESULTS: STEC-HUS was diagnosed in a 4-year-old girl with classic HUS, including low C3. Peritoneal dialysis was started due to hypertension, oligoanuria, and pleural effusion. She evolved with generalized tonic-clonic seizures and required mechanical ventilation. MRI reported multiple supra- and infratentorial ischemic lesions with laminar/striatal cortical necrosis and leukoencephalopathy. After two eculizumab doses, a significative stabilization in diuresis, blood pressure, creatinine, and C3 was achieved. At the third week, episodes of massive digestive bleeding and a life-threatening condition required a colectomy thus preserving the ileocecal valve. Due to atypical evolution, a genetic study was considered, identifying two heterozygous variants (CFH S1191L/V1197A). CONCLUSION: STEC-HUS in patients with a genetic predisposition has been previously reported, but the low frequency of occurrence makes it a rare disease. As in the present case, patients with atypical course might benefit from genetic analysis to evaluate early eculizumab initiation and to better understand its phenotype. A higher resolution version of the Graphical abstract is available as Supplementary information.

Asunto(s)

Infecciones por Escherichia coli , Síndrome Hemolítico-Urémico , Escherichia coli Shiga-Toxigénica , Femenino , Humanos , Infecciones por Escherichia coli/complicaciones , Escherichia coli Shiga-Toxigénica/genética , Síndrome Hemolítico-Urémico/complicaciones , Síndrome Hemolítico-Urémico/tratamiento farmacológico , Síndrome Hemolítico-Urémico/genética , Proteínas del Sistema Complemento , Mutación

RESUMEN

Shiga Toxin-producing Escherichia coli (STEC) is recognized as being responsible for a large number of foodborne illnesses around the world. The pathogenicity of STEC has been related to Stx toxins. However, the ability of STEC to colonize the host and other surfaces can be essential for developing its pathogenicity. Different virulence profiles detected in STEC could cause the emergence of strains carrying new genes codified in new pathogenicity islands linked to metabolism and adherence. Biofilm formation is a spontaneous mechanism whereby STEC strains resist in a hostile environment being able to survive and consequently infect the host through contaminated food and food contact surfaces. Biofilm formation shows intra-and inter-serotype variability, and its formation does not depend only on the microorganisms involved. Other factors related to the environment (such as pH, temperature) and the surface (stainless steel and polystyrene) influence biofilm expression. The «One Health¼ concept implies the interrelation between public, animal, and environmental health actors to ensure food safety, prevent cross-contamination and resistance to sanitizers, highlighting the need to identify emerging pathogens through new molecular markers of rapid detection that involve STEC strains carrying the Locus of Enterocyte Effacement or Locus of Adhesion and Autoaggregation.

Asunto(s)

Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Animales , Escherichia coli Shiga-Toxigénica/genética , Virulencia/genética , Biopelículas , Factores de Virulencia/genética , Islas Genómicas/genética , Proteínas de Escherichia coli/genética

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) is estimated to cause over two million cases of human disease annually. Trinidad and Tobago is one of the largest livestock producer and consumer of sheep and goat meat in the Caribbean, however, the potential role of these animals in the epidemiology of STEC infections has not been previously described. To fill this critical gap in knowledge, the prevalence of Shiga toxin genes (stx1 and stx2) shed in the faeces of healthy sheep (n = 204) and goats (n = 105) in Trinidad was investigated. Based on PCR screening, goats had a higher stx prevalence than sheep (46% vs 35%, P = 0.06). Most of the recovered STEC isolates were positive for stx1 only; and only three isolates were positive for the eae gene. None of the recovered isolates belonged to the O157 serogroup. In both species, the prevalence of stx was higher in young animals versus older animals. Sheep reared on deep litter flooring (43%) had a higher prevalence than sheep reared other flooring types, however this was not the same for goats. The presence of cows on the same premise was not an associated predictor for STEC carriage in sheep or goats. This study demonstrates that although sheep and goats in Trinidad are reservoirs for stx-positive E. coli isolates, no fecal samples tested positive for O157 STEC, harbored. Furthermore, it appears that non-O157 stx-positive isolates harbored by these animals do not pose a significant threat to human health.

Asunto(s)

Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Humanos , Femenino , Ovinos , Animales , Bovinos , Toxina Shiga/genética , Cabras , Trinidad y Tobago/epidemiología , Serogrupo , Factores de Virulencia/genética , Escherichia coli Shiga-Toxigénica/genética , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética

RESUMEN

The presence of Escherichia coli in the vaginal microbiome has been associated with pregnancy complications. In previous works, we demonstrated that Shiga toxin-producing Escherichia coli (STEC) can produce abortion and premature delivery in rats and that Shiga toxin type 2 (Stx2) can impair human trophoblast cell lines. The hypothesis of this work was that STEC may colonize the lower female reproductive tract and be responsible for adverse pregnancy outcomes. Thus, the aim of this work was to evaluate the presence and prevalence of virulence factor genes from STEC in the endocervix of asymptomatic pregnant women. For that purpose, endocervical swabs were collected from pregnant women during their prenatal examination. Swab samples were enriched in a differential medium to select Enterobacteria. Then, positive samples were analyzed by PCR to detect genes characteristic of Escherichia sp. (such as uidA and yaiO), genes specific for portions of the rfb (O-antigen-encoding) regions of STEC O157 (rfbO157), and STEC virulence factor genes (such as stx1, stx2, eae, lpfAO113, hcpA, iha, sab, subAB). The cytotoxic effects of stx2-positive supernatants from E. coli recovered from the endocervix were evaluated in Vero cells. Our results showed that 11.7% of the endocervical samples were positive for E. coli. Additionally, we found samples positive for stx2 and other virulence factors for STEC. The bacterial supernatant from an isolate identified as E. coli O113:NT, carrying the stx2 gene, exhibited cytotoxic activity in Vero, Swan 71 and Hela cells. Our results open a new perspective regarding the presence of STEC during pregnancy.

Asunto(s)

Escherichia coli O157 , Proteínas de Escherichia coli , Resultado del Embarazo , Toxina Shiga II , Escherichia coli Shiga-Toxigénica , Factores de Virulencia , Animales , Cuello del Útero/microbiología , Chlorocebus aethiops , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Femenino , Células HeLa , Humanos , Embarazo , Resultado del Embarazo/genética , Mujeres Embarazadas , Ratas , Factores de Riesgo , Toxina Shiga II/genética , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/metabolismo , Células Vero , Factores de Virulencia/genética

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen capable of causing illness in humans. In a previous study, our group showed that a STEC isolate belonging to O22:H8 serotype (strain 154) can interfere with STEC O157:H7 colonization both in vitro and in vivo. Using whole-genome sequencing and genomic comparative, we predicted a subset of genes acquired by O22:H8 strain 154 through horizontal gene transfer that might be responsible for the phenotype previously described by our group. Among them were identified genes related to the pathogenesis of non-LEE (locus of enterocyte effacement) STEC, specific metabolic processes, antibiotic resistance and genes encoding for the T6SS-1 that is related to inter-bacterial competition. In addition, we showed that this strain carries stx1c and stx2dact, a mucus-inducible variant. The results obtained in this study provide insights into STEC genomic plasticity and the importance of genomic islands in the adaptation and pathogenesis of this pathogen.

Asunto(s)

Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Animales , Bovinos , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Filogenia , Toxina Shiga/genética , Escherichia coli Shiga-Toxigénica/genética , Factores de Virulencia/genética , Factores de Virulencia/metabolismo

RESUMEN

Capybaras are rodent widely distributed in South America, which inhabit lakeside areas including ecological parks and urban sites. Due to anthropological interaction, monitoring zoonotic pathogens in wildlife is essential for One Health. We investigated faecal samples from capybaras living in an urban area in Rio Branco (Acre, Brazil) for the presence diarrhoeagenic E. coli. Virulence factors from shiga toxin-producing E. coli (STEC), enterohaemorrhagic E. coli (EHEC), and enteropathogenic E. coli (EPEC) were screened by PCR. We detected at least one virulence factor in 81% of the animals, being classified as STEC and EHEC pathotypes. The presence of zoonotic E. coli in capybaras is a warning due to the highly frequent anthropological interactions with wild animals in this area. Our findings highlight the importance of investigating wild animals as carriers of zoonotic E. coli, requiring further investigations into wildlife surveillance and epidemiological monitoring.

Asunto(s)

Escherichia coli Enteropatógena , Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Animales , Animales Salvajes , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Roedores , Toxina Shiga/genética , Escherichia coli Shiga-Toxigénica/genética , Factores de Virulencia/genética