Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.316
Filtrar
1.
Emerg Microbes Infect ; 9(1): 535-538, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32122270

RESUMEN

Worldwide emergence of Salmonella enterica serovar Newport (S. Newport) infection in humans, in parallel with a significant increasing prevalence of antimicrobial resistance (AR), is a serious public health concern. However, the prevalence of S. Newport resistance in China remains largely unknown. A retrospective study of 287 S. Newport clinical isolates collected during 1997-2018 was undertaken for characterization of AR profiles using the micro-dilution assay. We found a recent emergence of colistin resistance in four Chinese clinical isolates, including mcr-1-positive isolates. Importantly, phylogenomic and microbiological investigations indicate multiple independent clonal transmission of colistin-resistant S. Newport isolates of different seafood origins. Our study highlights potential reservoirs for transmission of colistin resistance and suggests that the global food supply chain may facilitate this dissemination.


Asunto(s)
Colistina/farmacología , Infecciones por Salmonella/microbiología , Salmonella enterica/aislamiento & purificación , Farmacorresistencia Bacteriana , Humanos , Salmonella enterica/efectos de los fármacos
2.
PLoS Negl Trop Dis ; 14(2): e0008036, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32106221

RESUMEN

BACKGROUND: Multi-drug resistant typhoid fever remains an enormous public health threat in low and middle-income countries. However, we still lack a detailed understanding of the epidemiology and genomics of S. Typhi in many regions. Here we have undertaken a detailed genomic analysis of typhoid in urban Dhaka, Bangladesh to unravel the population structure and antimicrobial resistance patterns in S. Typhi isolated between 2004-2016. PRINCIPAL FINDINGS: Whole genome sequencing of 202 S. Typhi isolates obtained from three study locations in urban Dhaka revealed a diverse range of S. Typhi genotypes and AMR profiles. The bacterial population within Dhaka were relatively homogenous with little stratification between different healthcare facilities or age groups. We also observed evidence of exchange of Bangladeshi genotypes with neighboring South Asian countries (India, Pakistan and Nepal) suggesting these are circulating throughout the region. This analysis revealed a decline in H58 (genotype 4.3.1) isolates from 2011 onwards, coinciding with a rise in a diverse range of non-H58 genotypes and a simultaneous rise in isolates with reduced susceptibility to fluoroquinolones, potentially reflecting a change in treatment practices. We identified a novel S. Typhi genotype, subclade 3.3.2 (previously defined only to clade level, 3.3), which formed two localized clusters (3.3.2.Bd1 and 3.3.2.Bd2) associated with different mutations in the Quinolone Resistance Determining Region (QRDR) of gene gyrA. SIGNIFICANCE: Our analysis of S. Typhi isolates from urban Dhaka, Bangladesh isolated over a twelve year period identified a diverse range of AMR profiles and genotypes. The observed increase in non-H58 genotypes associated with reduced fluoroquinolone susceptibility may reflect a change in treatment practice in this region and highlights the importance of continued molecular surveillance to monitor the ongoing evolution of AMR in Dhaka. We have defined new genotypes and lineages of Bangladeshi S. Typhi which will facilitate the identification of these emerging AMR clones in future surveillance efforts.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/microbiología , Salmonella typhi/efectos de los fármacos , Bangladesh/epidemiología , ADN Bacteriano/genética , Genoma Bacteriano , Genotipo , Humanos , Internacionalidad , Polimorfismo de Nucleótido Simple , Estudios Retrospectivos , Infecciones por Salmonella/transmisión , Salmonella typhi/genética , Salmonella typhi/aislamiento & purificación , Factores de Tiempo , Viaje , Población Urbana
3.
PLoS One ; 15(1): e0220427, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32004341

RESUMEN

Identifying and controlling the emergence of antimicrobial resistance (AMR) is a high priority for researchers and public health officials. One critical component of this control effort is timely detection of emerging or increasing resistance using surveillance programs. Currently, detection of temporal changes in AMR relies mainly on analysis of the proportion of resistant isolates based on the dichotomization of minimum inhibitory concentration (MIC) values. In our work, we developed a hierarchical Bayesian latent class mixture model that incorporates a linear trend for the mean log2MIC of the non-resistant population. By introducing latent variables, our model addressed the challenges associated with the AMR MIC values, compensating for the censored nature of the MIC observations as well as the mixed components indicated by the censored MIC distributions. Inclusion of linear regression with time as a covariate in the hierarchical structure allowed modelling of the linear creep of the mean log2MIC in the non-resistant population. The hierarchical Bayesian model was accurate and robust as assessed in simulation studies. The proposed approach was illustrated using Salmonella enterica I,4,[5],12:i:- treated with chloramphenicol and ceftiofur in human and veterinary samples, revealing some significant linearly increasing patterns from the applications. Implementation of our approach to the analysis of an AMR MIC dataset would provide surveillance programs with a more complete picture of the changes in AMR over years by exploring the patterns of the mean resistance level in the non-resistant population. Our model could therefore serve as a timely indicator of a need for antibiotic intervention before an outbreak of resistance, highlighting the relevance of this work for public health. Currently, however, due to extreme right censoring on the MIC data, this approach has limited utility for tracking changes in the resistant population.


Asunto(s)
Antibacterianos/farmacología , Cefalosporinas/farmacología , Cloranfenicol/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Salmonella enterica/efectos de los fármacos , Animales , Teorema de Bayes , Conjuntos de Datos como Asunto , Humanos , Modelos Lineales , Pruebas de Sensibilidad Microbiana , Salud Pública , Infecciones por Salmonella/microbiología , Salmonella enterica/crecimiento & desarrollo , Salmonella enterica/aislamiento & purificación , Porcinos , Enfermedades de los Porcinos/microbiología
4.
PLoS One ; 15(1): e0220484, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31990938

RESUMEN

The growing occurrence of multidrug-resistant (MDR) Salmonella enterica in poultry has been reported with public health concern worldwide. We reported, recently, the occurrence of Escherichia coli and Salmonella enterica serovars carrying clinically relevant resistance genes in dairy cattle farms in the Wakiso District, Uganda, highlighting an urgent need to monitor food-producing animal environments. Here, we present the prevalence, antimicrobial resistance, and sequence type of 51 Salmonella isolates recovered from 379 environmental samples from chicken farms in Uganda. Among the Salmonella isolates, 32/51 (62.7%) were resistant to at least one antimicrobial, and 10/51 (19.6%) displayed multiple drug resistance. Through PCR, five replicon plasmids were identified among chicken Salmonella isolates including IncFIIS 17/51 (33.3%), IncI1α 12/51 (23.5%), IncP 8/51 (15.7%), IncX1 8/51 (15.7%), and IncX2 1/51 (2.0%). In addition, we identified two additional replicons through WGS (Whole Genome Sequencing; ColpVC and IncFIB). A significant seasonal difference between chicken sampling periods was observed (p = 0.0017). We conclude that MDR Salmonella highlights the risks posed to animals and humans. Implementing a robust, integrated surveillance system will aid in monitoring MDR zoonotic threats.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Genes Bacterianos , Plásmidos/metabolismo , Enfermedades de las Aves de Corral/epidemiología , Infecciones por Salmonella/epidemiología , Salmonella enterica/genética , Animales , Antibacterianos/clasificación , Antibacterianos/farmacología , Pollos/microbiología , Granjas , Humanos , Vigilancia Inmunológica , Plásmidos/química , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/transmisión , Prevalencia , Replicón , Infecciones por Salmonella/microbiología , Infecciones por Salmonella/transmisión , Salmonella enterica/efectos de los fármacos , Salmonella enterica/aislamiento & purificación , Estaciones del Año , Uganda/epidemiología , Secuenciación Completa del Genoma
5.
Food Microbiol ; 87: 103394, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31948635

RESUMEN

Salmonella is a major pathogen having a public health and economic impact in both humans and animals. Six serotypes of the Salmonella genus are mentioned in the Belgian and European regulation as to be rapidly excluded from the food chain (EU regulation N°2160/2003, Belgian royal decree 27/04/2017). The reference method for Salmonella serotyping, including slide-agglutination and biochemical tests, is time-consuming, expensive, not always objective, and therefore does not match the fast identification criteria required by the legislation. In this study, a molecular method, using genetic markers detected by Multiplex Oligonucleotide Ligation - PCR and Luminex technology, was developed for the identification of the 6 Salmonella serotypes and their variants subjected to an official control. The resulting method was validated with the analysis of 971 Salmonella isolated from different matrixes (human, animal, food or environment) and 33 non-Salmonella strains. The results were compared with the reference identifications, achieving an accuracy of 99.7%. The cost-effective high-throughput genoserotyping assay is performed in 1 day and generates objective results, thanks to the automatic interpretation of raw data using a barcode system. In conclusion, it is fully adapted to the implementation in first line laboratories and meets the requirements of the regulation.


Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Oligonucleótidos/genética , Salmonella/aislamiento & purificación , Animales , Microbiología Ambiental , Humanos , Salmonella/clasificación , Salmonella/genética , Infecciones por Salmonella/microbiología , Sensibilidad y Especificidad
6.
J Agric Food Chem ; 68(1): 128-137, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31825613

RESUMEN

Salmonellosis is a world-wide epidemic, and n-3 long chain polyunsaturated fatty acids (LCPUFAs) possess various health benefits. This study is aimed to investigate the preventive effects of n-3 LCPUFAs against Salmonella infection. By pretreatment with n-3 LCPUFAs, but not n-6 LCPUFAs, the survival rate of the infected mice was increased. Further studies showed that n-3 LCPUFAs significantly increased the fecal contents of short-chain fatty acids (SCFAs). The cytokine expression in the liver and production in serum were both modulated by n-3 LCPUFAs into an anti-inflammatory profile against infection. Moreover, the changes in gut microbiota by n-3 LCPUFAs favored the host against pathogens, closely related to the modified SCFA production and immune responses. In conclusion, n-3 LCPUFAs prevented Salmonella infection through multiple mechanisms, especially by the interaction with gut microbiota and host immunology. Our results suggested great perspectives for n-3 LCPUFAs and their related products to control the prevalence of Salmonella, a most predominant food-borne pathogen.


Asunto(s)
Suplementos Dietéticos/análisis , Ácidos Grasos Omega-3/administración & dosificación , Infecciones por Salmonella/prevención & control , Animales , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Modelos Animales de Enfermedad , Ácidos Grasos Volátiles/metabolismo , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Humanos , Ratones , Ratones Endogámicos C57BL , Salmonella/efectos de los fármacos , Salmonella/fisiología , Infecciones por Salmonella/microbiología
7.
Nat Immunol ; 21(1): 86-100, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31844327

RESUMEN

By developing a high-density murine immunophenotyping platform compatible with high-throughput genetic screening, we have established profound contributions of genetics and structure to immune variation (http://www.immunophenotype.org). Specifically, high-throughput phenotyping of 530 unique mouse gene knockouts identified 140 monogenic 'hits', of which most had no previous immunologic association. Furthermore, hits were collectively enriched in genes for which humans show poor tolerance to loss of function. The immunophenotyping platform also exposed dense correlation networks linking immune parameters with each other and with specific physiologic traits. Such linkages limit freedom of movement for individual immune parameters, thereby imposing genetically regulated 'immunologic structures', the integrity of which was associated with immunocompetence. Hence, we provide an expanded genetic resource and structural perspective for understanding and monitoring immune variation in health and disease.


Asunto(s)
Infecciones por Enterobacteriaceae/inmunología , Variación Genética/genética , Ensayos Analíticos de Alto Rendimiento/métodos , Inmunofenotipificación/métodos , Infecciones por Salmonella/inmunología , Animales , Citrobacter/inmunología , Infecciones por Enterobacteriaceae/microbiología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Animales , Salmonella/inmunología , Infecciones por Salmonella/microbiología
8.
Emerg Microbes Infect ; 9(1): 1-4, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31859589

RESUMEN

CRISPR-based typing was performed to subtype isolates of S. Typhimurium and its monophasic variant Salmonella 4,[5],12:i:- from humans and animals between 2009 and 2017 in China. CRISPR typing classified all isolates into two lineages and four sub-lineages. All isolates from Lineage II and Lineage IB-1 were Salmonella Typhimurium. All of Salmonella 4,[5],12:i: - isolates were distributed in Lineage IA and Lineage IB-2, which all belonged to ST34 by MLST typing. Only Lineage IB-2 contained ST34 isolates from both Salmonella Typhimurium and Salmonella 4,[5],12:i:-. Among the isolates of ST34, TST4 was identified as the most common CRISPR type representing 86.5% of Salmonella 4,[5],12:i:- and 14.5 % of Salmonella Typhimurium mainly from pigs and humans. This study demonstrated that TST4-ST34 isolates were predominant in Salmonella 4,[5],12:i:-, and pig was the main reservoir for Salmonella 4,[5],12:i:- in China, which might have the potential to transmit to humans by pig production.


Asunto(s)
Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Reservorios de Enfermedades , Técnicas de Genotipaje/métodos , Carne/microbiología , Salmonella typhimurium/clasificación , Salmonella typhimurium/aislamiento & purificación , Sus scrofa , Animales , China , Diarrea/microbiología , Electroforesis en Gel de Campo Pulsado , Humanos , Tipificación de Secuencias Multilocus , Filogenia , Infecciones por Salmonella/microbiología , Salmonella typhimurium/genética
9.
Pol J Microbiol ; 68(4): 439-447, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31880888

RESUMEN

Salmonella infection is most common in patients with infected aortic aneurysm, especially in Asia. When the aortic wall is heavily atherosclerotic, the intima is vulnerable to invasion by Salmonella, leading to the development of infected aortic aneurysm. By using THP-1 macrophage-derived foam cells to mimic atherosclerosis, we investigated the role of three Salmonella enterica serotypes - Typhimurium, Enteritidis, and Choleraesuis - in foam cell autophagy and inflammasome formation. Herein, we provide possible pathogenesis of Salmonella-associated infected aortic aneurysms. Three S. enterica serotypes with or without virulence plasmid were studied. Through Western blotting, we investigated cell autophagy induction and inflammasome formation in Salmonella-infected THP-1 macrophage-derived foam cells, detected CD36 expression after Salmonella infection through flow cytometry, and measured interleukin (IL)-1ß, IL-12, and interferon (IFN)-α levels through enzyme-linked immunosorbent assay. At 0.5 h after infection, plasmid-bearing S. Enteritidis OU7130 induced the highest foam cell autophagy - significantly higher than that induced by plasmid-less OU7067. However, plasmid-bearing S. Choleraesuis induced less foam cell autophagy than did its plasmid-less strain. In foam cells, plasmid-less Salmonella infection (particularly S. Choleraesuis OU7266 infection) led to higher CD36 expression than did plasmid-bearing strains infection. OU7130 and OU7266 infection induced the highest IL-1ß secretion. OU7067-infected foam cells secreted the highest IL-12p35 level. Plasmid-bearing S. Typhimurium OU5045 induced a higher IFN-α level than did other Salmonella serotypes. Salmonella serotypes are correlated with foam cell autophagy and IL-1ß secretion. Salmonella may affect the course of foam cells formation, or even aortic aneurysm, through autophagy.Salmonella infection is most common in patients with infected aortic aneurysm, especially in Asia. When the aortic wall is heavily atherosclerotic, the intima is vulnerable to invasion by Salmonella, leading to the development of infected aortic aneurysm. By using THP-1 macrophage-derived foam cells to mimic atherosclerosis, we investigated the role of three Salmonella enterica serotypes ­ Typhimurium, Enteritidis, and Choleraesuis ­ in foam cell autophagy and inflammasome formation. Herein, we provide possible pathogenesis of Salmonella-associated infected aortic aneurysms. Three S. enterica serotypes with or without virulence plasmid were studied. Through Western blotting, we investigated cell autophagy induction and inflammasome formation in Salmonella-infected THP-1 macrophage-derived foam cells, detected CD36 expression after Salmonella infection through flow cytometry, and measured interleukin (IL)-1ß, IL-12, and interferon (IFN)-α levels through enzyme-linked immunosorbent assay. At 0.5 h after infection, plasmid-bearing S. Enteritidis OU7130 induced the highest foam cell autophagy ­ significantly higher than that induced by plasmid-less OU7067. However, plasmid-bearing S. Choleraesuis induced less foam cell autophagy than did its plasmid-less strain. In foam cells, plasmid-less Salmonella infection (particularly S. Choleraesuis OU7266 infection) led to higher CD36 expression than did plasmid-bearing strains infection. OU7130 and OU7266 infection induced the highest IL-1ß secretion. OU7067-infected foam cells secreted the highest IL-12p35 level. Plasmid-bearing S. Typhimurium OU5045 induced a higher IFN-α level than did other Salmonella serotypes. Salmonella serotypes are correlated with foam cell autophagy and IL-1ß secretion. Salmonella may affect the course of foam cells formation, or even aortic aneurysm, through autophagy.


Asunto(s)
Aneurisma de la Aorta/microbiología , Infecciones por Salmonella/microbiología , Salmonella typhimurium/patogenicidad , Animales , Aneurisma de la Aorta/genética , Aneurisma de la Aorta/inmunología , Línea Celular , Humanos , Interferón-alfa/genética , Interferón-alfa/inmunología , Interleucina-12/genética , Interleucina-12/inmunología , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Antígeno Ki-1/genética , Antígeno Ki-1/inmunología , Macrófagos/inmunología , Macrófagos/microbiología , Monocitos/inmunología , Monocitos/microbiología , Plásmidos/genética , Plásmidos/metabolismo , Infecciones por Salmonella/genética , Infecciones por Salmonella/inmunología , Salmonella typhimurium/genética , Salmonella typhimurium/fisiología , Serogrupo , Virulencia
10.
PLoS Negl Trop Dis ; 13(10): e0007782, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31609964

RESUMEN

BACKGROUND: Salmonella Typhimurium and Enteritidis are major causes of bloodstream infection in children in sub-Saharan Africa. This study assessed evidence for their zoonotic versus human reservoir. METHODS: Index patients were children with blood culture confirmed Salmonella infection recruited during a microbiological surveillance study in Nanoro, rural Burkina between May 2013 and August 2014. After consent, their households were visited. Stool from household members and livestock (pooled samples per species) as well as drinking water were cultured for Salmonella. Isolates with identical serotype obtained from index patient and any household sample were defined as "paired isolates" and assessed for genetic relatedness by multilocus variable number tandem-repeat analysis (MLVA) and whole-genome sequencing (WGS). RESULTS: Twenty-nine households were visited for 32/42 (76.2%) eligible index patients: two households comprised two index patients each, and in a third household the index patient had a recurrent infection. Among the 32 index patients, serotypes were Salmonella Typhimurium (n = 26), Salmonella Enteritidis (n = 5) and Salmonella Freetown (n = 1). All Typhimurium isolates were sequence type (ST)313. Median delay between blood culture sampling and household visits was 13 days (range 6-26). Salmonella was obtained from 16/186 (8.6%) livestock samples (13 serotypes) and 18/290 (6.2%) household members (9 serotypes). None of the water samples yielded Salmonella. Paired Salmonella Typhimurium isolates were obtained from three households representing four index patients. MLVA types were identical in two pairs and similar in the third (consisting of two index patients and one household member). WGS showed a strong genetic relatedness with 0 to 2 core genome SNPs difference between pairs on a household level. Livestock samples did not yield any Salmonella Typhimurium or Salmonella Enteritidis, and the latter was exclusively obtained from blood culture. Other serotypes shared by human and/or livestock carriers in the same household were Salmonella Derby, Drac, Tennessee and Muenster. CONCLUSIONS/SIGNIFICANCE: The current study provides further evidence of a human reservoir for invasive non-Typhoidal Salmonella (iNTS) in sub-Saharan Africa.


Asunto(s)
Reservorios de Enfermedades/microbiología , Composición Familiar , Infecciones por Salmonella/microbiología , Salmonella/clasificación , Salmonella/aislamiento & purificación , Adolescente , Animales , Burkina Faso/epidemiología , Niño , Preescolar , Monitoreo del Ambiente , Heces/microbiología , Femenino , Humanos , Lactante , Ganado , Masculino , Tipificación de Secuencias Multilocus , Filogenia , Salmonella/genética , Infecciones por Salmonella/epidemiología , Salmonella enterica/genética , Salmonella enterica/aislamiento & purificación , Salmonella enteritidis/genética , Salmonella enteritidis/aislamiento & purificación , Salmonella typhimurium/genética , Salmonella typhimurium/aislamiento & purificación , Serogrupo , Microbiología del Agua , Secuenciación Completa del Genoma
11.
Artículo en Inglés | MEDLINE | ID: mdl-31610774

RESUMEN

An outbreak of Salmonella enterica serovar Typhimurium with closely related Multiple Locus Variable-number Tandem Repeat Analysis (MLVA) patterns was detected by routine surveillance by the Australian Capital Territory Health Protection Service in May 2018. The outbreak consisted of three cases in 2018 (MLVA 03-10-10-09-496) and one in 2016 (MLVA 03-10-09-09-496), who reported eating home-cooked eggs from the same local producer. Environmental investigations found significant problems with egg cleaning, hand hygiene and documentation of food safety procedures on farm. Environmental samples collected from the farm were found to have the same MLVA pattern as the 2018 cases. Although poor farm practices most likely led to contamination of the eggs, this outbreak highlights the need for consumer education about safe handling of eggs in the home.


Asunto(s)
Huevos/microbiología , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/microbiología , Adolescente , Adulto , Territorio de la Capital Australiana/epidemiología , Niño , Brotes de Enfermedades , Monitoreo del Ambiente , Femenino , Microbiología de Alimentos , Gastroenteritis/epidemiología , Gastroenteritis/microbiología , Humanos , Masculino , Persona de Mediana Edad , Repeticiones de Minisatélite , Salud Pública , Salmonella typhimurium , Serogrupo , Adulto Joven
12.
Nat Struct Mol Biol ; 26(10): 941-945, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31570877

RESUMEN

Bacterial locomotion by rotating flagella is achieved through the hook, which transmits torque from the motor to the filament. The hook is a tubular structure composed of a single type of protein, yet it adopts a curved shape. To perform its function, it must be simultaneously flexible and torsionally rigid. The molecular mechanism by which chemically identical subunits form such a dynamic structure is unknown. Here, we show the complete structure of the hook from Salmonella enterica in its supercoiled 'curved' state, at 2.9 Å resolution. Subunits in the curved hook are grouped into 11 distinctive conformations, each shared along 11 protofilaments. The domains of the elongated hook subunit behave as rigid bodies connected by two hinge regions. The reconstituted model demonstrates how identical subunits can dynamically change conformation by physical interactions while bending. These multiple subunit states contradict the two-state model, which is a key feature of flagellar polymorphism.


Asunto(s)
Proteínas Bacterianas/ultraestructura , Flagelos/ultraestructura , Salmonella typhimurium/ultraestructura , Proteínas Bacterianas/química , Microscopía por Crioelectrón , Flagelos/química , Humanos , Modelos Moleculares , Conformación Proteica , Infecciones por Salmonella/microbiología , Salmonella typhimurium/química
13.
BMC Vet Res ; 15(1): 312, 2019 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-31477105

RESUMEN

BACKGROUND: Salmonella is generally considered as a human pathogen causing typhoid fever and gastrointestinal infections called salmonellosis, with S. Enteritidis and S. Typhimurium strains as the main causative agents. Salmonella enterica strains have a wide host array including humans, birds, pigs, horses, dogs, cats, reptiles, amphibians and insects. Up to 90% of reptiles are the carriers of one or more serovars of Salmonella. Extraintestinal bacterial infections associated with reptiles pose serious health threat to humans. The import of exotic species of reptiles as pet animals to Europe correlates with the emergence of Salmonella serotypes, which not found previously in European countries. The presented study is a new report about Salmonella serotypes associated with exotic reptiles in Poland. The goal of this research was to examine the zoonotic potential of Salmonella strains isolated from reptiles by comparative analysis with S. Enteritidis strains occurring in human population and causing salmonellosis. RESULTS: The main findings of our work show that exotic reptiles are asymptomatic carriers of Salmonella serovars other than correlated with salmonellosis in humans (S. Enteritidis, S. Typhimurium). Among the isolated Salmonella strains we identified serovars that have not been reported earlier in Poland, for example belonging to subspecies diarizonae and salamae. Restriction analysis with Pulsed-field Gel Electrophoresis (PFGE), showed a great diversity among Salmonella strains isolated from reptiles. Almost all tested strains had distinct restriction patterns. While S. Enteritidis strains were quite homogeneous in term of phylogenetic relations. Most of the tested VGs were common for the two tested groups of Salmonella strains. CONCLUSIONS: The obtained results show that Salmonella strains isolated from reptiles share most of virulence genes with the S. Enteritidis strains and exhibit a greater phylogenetic diversity than the tested S. Enteritidis population.


Asunto(s)
Electroforesis en Gel de Campo Pulsado , Reptiles/microbiología , Infecciones por Salmonella/microbiología , Salmonella enterica/genética , Animales , Portador Sano , Cromatografía de Gases , ADN Bacteriano , Genotipo , Humanos , Salmonella enterica/patogenicidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrometría de Masas en Tándem , Virulencia , Zoonosis
14.
J Microbiol ; 57(11): 1012-1018, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31555991

RESUMEN

Although phosphatase and tensin homolog (PTEN) is typically considered a tumor-suppressor gene, it was recently suggested that PTEN regulates TLR5-induced immune and inflammatory responses in intestinal epithelial cells (IECs), suggesting an immunomodulatory function of PTEN in the gut. However, this alternative function of PTEN has not yet been evaluated in an in vivo context of protection against enteropathogenic bacteria. To address this, we utilized IEC-restricted Pten knockout (PtenΔIEC/ΔIEC) and littermate Pten+/+ mice. These mice were subjected to the streptomycin-pre-treated mouse model of Salmonella infection, and subsequently given an oral gavage of a low inoculum (2 × 104 CFU) of Salmonella enterica serovar Typhimurium (S. Typhimurium). This bacterial infection not only increased the mortality of PtenΔIEC/ΔIEC mice compared to Pten+/+ mice, but also induced deleterious gastrointestinal inflammation in PtenΔIEC/ΔIEC mice manifested by massive histological damage to the intestinal mucosa. S. Typhimurium infection up-regulated pro-inflammatory cytokine production in the intestine of PtenΔIEC/ΔIEC mice compared to controls. Furthermore, bacterial loads were greatly increased in the liver, mesenteric lymph node, and spleen of PtenΔIEC/ΔIEC mice compared to controls. Together, these results suggest that IEC-restricted Pten deficiency renders the host greatly susceptible to Salmonella infection and support an immune-regulatory role of PTEN in the gut.


Asunto(s)
Células Epiteliales/inmunología , Eliminación de Gen , Intestinos/inmunología , Fosfohidrolasa PTEN/genética , Infecciones por Salmonella/inmunología , Salmonella typhimurium/inmunología , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Células Epiteliales/microbiología , Mucosa Intestinal/microbiología , Intestinos/microbiología , Hígado/microbiología , Hígado/patología , Ganglios Linfáticos/microbiología , Ganglios Linfáticos/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosfohidrolasa PTEN/metabolismo , Infecciones por Salmonella/microbiología , Infecciones por Salmonella/patología , Bazo/microbiología , Bazo/patología , Receptores Toll-Like
15.
Nat Commun ; 10(1): 4039, 2019 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-31492864

RESUMEN

Antibiotic therapy is usually not recommended for salmonellosis, as it is associated with prolonged fecal carriage without reducing symptom duration or severity. Here we show that antibiotics encapsulated in hydrogen sulfide (H2S)-responsive glycovesicles may be potentially useful for the treatment of salmonellosis. The antibiotics are released in the presence of Salmonella, which is known to produce H2S. This approach prevents the quick absorption of antibiotics into the bloodstream, allows localized targeting of the pathogen in the gut, and alleviates disease symptoms in a mouse infection model. In addition, it reduces antibiotic-induced changes in the gut microbiota, and increases the abundance of potentially beneficial lactobacilli due to the release of prebiotic xylooligosaccharide analogs.


Asunto(s)
Antibacterianos/farmacología , Glucuronatos/química , Sulfuro de Hidrógeno/farmacología , Oligosacáridos/química , Infecciones por Salmonella/tratamiento farmacológico , Salmonella/efectos de los fármacos , Animales , Antibacterianos/química , Antibacterianos/farmacocinética , Ciprofloxacino/química , Ciprofloxacino/farmacocinética , Ciprofloxacino/farmacología , Liberación de Fármacos , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/fisiología , Glucuronatos/metabolismo , Sulfuro de Hidrógeno/química , Sulfuro de Hidrógeno/farmacocinética , Ratones , Oligosacáridos/metabolismo , Salmonella/fisiología , Infecciones por Salmonella/microbiología , Resultado del Tratamiento
16.
Int J Mol Sci ; 20(18)2019 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-31487966

RESUMEN

Salmonella enterica serovar Typhimurium is a facultative intracellular pathogen that infects humans and animals. Survival and growth in host macrophages represents a crucial step for S. Typhimurium virulence. Many genes that are essential for S. Typhimurium proliferation in macrophages and associated with virulence are highly expressed during the intracellular lifecycle. yaeB, which encodes an RNA methyltransferase, is also upregulated during S. Typhimurium growth in macrophages. However, the involvement of YaeB in S. Typhimurium pathogenicity is still unclear. In this study, we investigated the role of YaeB in S. Typhimurium virulence. Deletion of yaeB significantly impaired S. Typhimurium growth in macrophages and virulence in mice. The effect of yaeB on pathogenicity was related to its activation of pstSCAB, a phosphate (Pi)-specific transport system that is verified here to be important for bacterial replication and virulence. Moreover, qRT-PCR data showed YaeB was induced by the acidic pH inside macrophages, and the acidic pH passed to YeaB through inhibiting global regulator histone-like nucleoid structuring (H-NS) which confirmed in this study can repress the expression of yaeB. Overall, these findings identified a new virulence regulatory network involving yaeB and provided valuable insights to the mechanisms through which acidic pH and low Pi regulate virulence.


Asunto(s)
Proteínas Bacterianas/metabolismo , Salmonella typhimurium/patogenicidad , ARNt Metiltransferasas/metabolismo , Animales , Carga Bacteriana , Proteínas Bacterianas/genética , Replicación del ADN , Femenino , Concentración de Iones de Hidrógeno , Ratones , Ratones Endogámicos BALB C , Células RAW 264.7 , Infecciones por Salmonella/microbiología , Salmonella typhimurium/genética , Virulencia/genética , ARNt Metiltransferasas/genética
17.
Rev Med Suisse ; 15(661): 1574-1577, 2019 Sep 04.
Artículo en Francés | MEDLINE | ID: mdl-31496191

RESUMEN

Gastroenteritis due to non-typhoidal Salmonella (NTS) is usually considered as a benign infection. NTS can nevertheless cause severe diseases with high mortality. Invasive NTS infections may present as bacteremia without other manifestations, particularly in immunocompromised hosts. They may also correspond to extra-digestive infections in various body sites. Patients with cardiovascular diseases are at risk for endovascular infections, aortitis being the most frequent. These infections are difficult to diagnose and require surgery.


Asunto(s)
Aortitis/microbiología , Infecciones por Salmonella/microbiología , Salmonella/patogenicidad , Anciano , Bacteriemia/microbiología , Enfermedades Cardiovasculares/microbiología , Gastroenteritis/microbiología , Humanos
19.
Food Microbiol ; 84: 103237, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31421774

RESUMEN

Between 1991 and 2014 the per capita notification rate of salmonellosis in Australia increased from 31.9 to 69.7 cases per 100,000 people. Salmonella Typhimurium accounted for nearly half the human cases until the end of 2014. In this study, we used cluster analysis tools to compare S. Typhimurium isolates from a chicken-meat study with those reported to the National Enteric Pathogen Surveillance System (NEPSS) from the coincident human and non-human populations. There was limited phage type diversity within all populations and a lack of specificity of MLVA profiling within phage types. The chicken-meat study isolates were not significantly clustered with the human cases and at least 7 non-human sources, based on typing profiles (PT/MLVA combination), could be implicated as a source of human cases during the same period. In the absence of a strong surveillance system representative of all putative sources, MLVA and phage typing alone or in combination are insufficient to identify the source of human cases.


Asunto(s)
Tipificación de Bacteriófagos , Brotes de Enfermedades , Fagos de Salmonella/clasificación , Salmonella typhimurium/clasificación , Animales , Técnicas de Tipificación Bacteriana , Bovinos , Pollos , Análisis por Conglomerados , Humanos , Repeticiones de Minisatélite , Aves de Corral/microbiología , Intoxicación Alimentaria por Salmonella/diagnóstico , Intoxicación Alimentaria por Salmonella/microbiología , Infecciones por Salmonella/diagnóstico , Infecciones por Salmonella/microbiología , Salmonella typhimurium/virología
20.
Food Funct ; 10(9): 5398-5412, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31397465

RESUMEN

In this study, the effects of three doses (diets containing <0.01, 0.15, 0.40 mg kg-1 Se) and two forms (sodium selenite and selenomethionine) of dietary Se supplementation on the intestinal physiology of untreated, dextran sodium sulfate-treated, and Salmonella typhimurium-infected mice were evaluated. The underlying modes of action of the varied doses and forms of Se supplementation were analyzed using fecal metabolomic and jejunal proteomic approaches. Compared with adequate Se (0.15 mg kg-1 Se) supplementation, Se-deficiency supplementation adversely affected the gut barrier and intestinal immune responses of the untreated mice and increased their susceptibility to experimental colitis and pathogen infection. In contrast, supranutritional Se (0.40 mg kg-1 Se) supplementation improved mouse intestinal physiology compared with adequate Se supplementation. Varied doses of Se supplementation differentially perturbed the fecal metabolic profiles of and jejunal protein expression in mice. Further, both forms of dietary Se supplementation, i.e., sodium selenite and selenomethionine, showed similar effects on the gut barrier and intestinal immune homeostasis but differentially affected fecal metabolites, such as neurosubstances and immunomodulators, and induced significant proteomic variations in various pathways, including the xenobiotic detoxification pathway and glutathione metabolism. Our results indicate that the doses and chemical forms of Se should be considered when developing dietary nutritional supplements for gut health.


Asunto(s)
Intestinos/inmunología , Infecciones por Salmonella/inmunología , Selenometionina/administración & dosificación , Selenito de Sodio/administración & dosificación , Animales , Suplementos Dietéticos/análisis , Humanos , Intestinos/efectos de los fármacos , Intestinos/microbiología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteómica , Infecciones por Salmonella/tratamiento farmacológico , Infecciones por Salmonella/microbiología , Salmonella typhimurium/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA