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1.
Rafael Oliveira dos Reis Margarida Neves Souza Maria Cristina Piccoli Cecconi Loeci Timm Nilo Ikuta Daniel Simon Jonas Michel Wolf Vagner Ricardo Lunge 《The Brazilian journal of infectious diseases》2018,22(5):424-432
Introduction
Nontyphoidal Salmonella serotypes are the main cause of human food-borne infection, including several hospitalization cases in the developing countries.Aim
To detect the main serotypes and to characterize the antibiotic resistance of human non-enteric and enteric nontyphoidal Salmonella from clinical isolates in Brazil.Methods
Salmonella serotypes were identified by microbiological and molecular methods. Susceptibility testing to antibiotics was performed by agar disk diffusion. Real-time PCRs were carried out for the detection of the genus Salmonella as well as serotypes Typhimurium and Enteritidis.Results
A total of 307 nontyphoidal Salmonella were isolated from 289 different patients in a reference laboratory (LACEN-RS) from Southern Brazil in a six-year period (2010–2015). There were 45 isolates from emerging cases and 244 from sporadic cases in hospitalized patients. Non-enteric isolates were detected in 42.6% of the patients from sources such as urine, blood and other clinical fluids. Serological and PCR-specific tests demonstrated that Typhimurium (48.4%) and Enteritidis (18.3%) were the most frequent serotypes. Typhimurium isolates were generally resistant to three or more antibiotic classes, while Enteritidis isolates to one or two classes. Typhimurium was the most frequent serotype in all samples (48.4%), mainly among the hospitalized patients (55.6%), and presented the highest rates of multidrug resistance (59.3% of the isolates of this serotype). Further, the prevalence of this serotype increased along the years of the study in comparison to other nontyphoidal Salmonella serotypes.Conclusion
Greater public health attention should be given to prevent salmonellosis in the community and in hospital settings to reduce the rates of Typhimurium strains with multidrug resistance. 相似文献2.
Purpose
To characterize the clinical and laboratory manifestations of non-typhi Salmonella gastroenteritis associated with bacteremia in children less than 36?months old.Methods
The study group included 17 patients, aged 2?C34?months, with non-typhi Salmonella gastroenteritis and bacteremia, hospitalized in a tertiary pediatric medical center during the period 1995?C2010. Clinical data were collected by medical chart review. Culture-related data were taken from the microbiology laboratory files. The results were compared with an assigned, age-matched, control group of 17 infants hospitalized with non-typhi Salmonella gastroenteritis without bacteremia.Results
Eleven cases (65%) occurred during the summer season. All patients presented with diarrhea, usually mixed with blood or mucus (clinical dysentery 65%). All but one had a high-grade fever (average 39.5°C). Three patients (19%) experienced convulsions during the acute episode of gastroenteritis. None of the patients had been previously treated with antibiotics. The most prevalent Salmonella serotype identified in the stool and blood was group C. Toxic appearance and convulsions on admission were more common among children with non-typhi Salmonella bacteremia, as opposed to those with non-typhi Salmonella gastroenteritis alone. No other epidemiological or laboratory differences were found.Conclusions
Non-typhi Salmonella gastroenteritis poses a risk of bacteremia not only in infants younger than 3?months of age, but also in children younger than 36?months of age. 相似文献3.
Nikaido E Giraud E Baucheron S Yamasaki S Wiedemann A Okamoto K Takagi T Yamaguchi A Cloeckaert A Nishino K 《Gut pathogens》2012,4(1):5-13
Background
Many Gram-positive and Gram-negative bacteria produce large quantities of indole as an intercellular signal in microbial communities. Indole demonstrated to affect gene expression in Escherichia coli as an intra-species signaling molecule. In contrast to E. coli, Salmonella does not produce indole because it does not harbor tnaA, which encodes the enzyme responsible for tryptophan metabolism. Our previous study demonstrated that E. coli-conditioned medium and indole induce expression of the AcrAB multidrug efflux pump in Salmonella enterica serovar Typhimurium for inter-species communication; however, the global effect of indole on genes in Salmonella remains unknown.Results
To understand the complete picture of genes regulated by indole, we performed DNA microarray analysis of genes in the S. enterica serovar Typhimurium strain ATCC 14028s affected by indole. Predicted Salmonella phenotypes affected by indole based on the microarray data were also examined in this study. Indole induced expression of genes related to efflux-mediated multidrug resistance, including ramA and acrAB, and repressed those related to host cell invasion encoded in the Salmonella pathogenicity island 1, and flagella production. Reduction of invasive activity and motility of Salmonella by indole was also observed phenotypically.Conclusion
Our results suggest that indole is an important signaling molecule for inter-species communication to control drug resistance and virulence of S. enterica. 相似文献4.
Background
Although antimicrobial resistance and persistence of resistant bacteria in humans and animals are major health concerns worldwide, the impact of antimicrobial resistance on bacterial intestinal colonization in healthy domestic animals has only been rarely studied. We carried out a retrospective analysis of the antimicrobial susceptibility status and the presence of resistance genes in intestinal commensal E. coli clones from clinically healthy pigs from one production unit with particular focus on effects of pheno- and/or genotypic resistance on different nominal and numerical intestinal colonization parameters. In addition, we compared the occurrence of antimicrobial resistance phenotypes and genotypes with the occurrence of virulence associated genes typical for extraintestinal pathogenic E. coli.Results
In general, up to 72.1% of all E. coli clones were resistant to ampicillin, chloramphenicol, kanamycin, streptomycin, sulfamethoxazole or tetracycline with a variety of different resistance genes involved. There was no significant correlation between one of the nominal or numerical colonization parameters and the absence or presence of antimicrobial resistance properties or resistance genes. However, there were several statistically significant associations between the occurrence of single resistance genes and single virulence associated genes.Conclusion
The demonstrated resistance to the tested antibiotics might not play a dominant role for an intestinal colonization success in pigs in the absence of antimicrobial drugs, or cross-selection of other colonization factors e.g. virulence associated genes might compensate "the cost of antibiotic resistance". Nevertheless, resistant strains are not outcompeted by susceptible bacteria in the porcine intestine.Trial Registration
The study was approved by the local animal welfare committee of the "Landesamt für Arbeitsschutz, Gesundheitsschutz und technische Sicherheit" Berlin, Germany (No. G0037/02). 相似文献5.
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Background
Apart from localized gastrointestinal infections, Escherichia coli and Salmonella species are major causes of systemic disease in both humans and animals. Salmonella spp. cause invasive infections such as enteric fever, septicemia, osteomyelitis and meningitis while certain types of E. coli can cause systemic infections, including pyelonephritis, meningitis and septicemia. These characteristic requires the involvement of a myriad of virulence factors.Methods
This study investigated the virulence factors of Escherichia coli and Salmonella species in clinical specimens from patients with diarrhoea presenting to health care centres in Oliver R. Tambo District Municipality, Eastern Cape Province, Republic of South Africa. Microbiology analysis involved the use of cultural and molecular techniques.Results
Out of a total of 315 samples screened, Salmonella isolates were obtained in 119 (37.8%) of cases and these comprised: S. choleraesuis (6%), S. enteritidis (4%), S. eppendorf (1%), S. hadar (1%), S. isangi (8%), S. panama (1%), S. typhi (52%), S. typhimurium (25%) and untyped Salmonella spp. (2%). Among the Salmonella species 87 (73.1%) were invasive. Using molecular diagnostic methods, diarrheagenic E. coli were detected in 90 cases (28.6%): the greater proportion of this were enteroaggregative E. coli (EAEC) 37 (41.1%), enteropathogenic E. coli (EPEC) 21 (23.3%) and enterohemorrhagic E. coli (EHEC) 21 (23.3%). The predominant virulence gene among the diarrheagenic E. coli was EAEC heat-stable enterotoxin astA genes while the virulence genes identified in the Salmonella strains were 15 (12.6%) flic and 105 (88.2%) inv genes. The amino acid identity of the representative genes showed 95-100% similarity to corresponding blast searched sequence.Conclusions
This study showed the diversity of virulence gene expression in two major enteric pathogens. S. typhi and enteroaggregative E. coli were the predominant enteropathogens in our study area with an indication that EAEC is endemic within our study population. It was observed among other things that some diarrheagenic E. coli isolated from apparently asymptomatic subjects expressed some virulence genes at frequency as high as seen in diarrheagenic cases. This study underlines the importance of understanding the virulence composition and diversity of pathogens for enhanced clinico-epidemiological monitoring and health care delivery. 相似文献8.
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Salmonella enterica serovar Typhimurium adhesion and cytotoxicity during epithelial cell stress is reduced by Lactobacillus rhamnosus GG 总被引:2,自引:0,他引:2
Background
Physiological stressors may alter susceptibility of the host intestinal epithelium to infection by enteric pathogens. In the current study, cytotoxic effect, adhesion and invasion of Salmonella enterica serovar Typhimurium (S. Typhimurium) to Caco-2 cells exposed to thermal stress (41°C, 1 h) was investigated. Probiotic bacteria have been shown to reduce interaction of pathogens with the epithelium under non-stress conditions and may have a significant effect on epithelial viability during infection; however, probiotic effect on pathogen interaction with epithelial cells under physiological stress is not known. Therefore, we investigated the influence of Lactobacillus rhamnosus GG and Lactobacillus gasseri on Salmonella adhesion and Salmonella-induced cytotoxicity of Caco-2 cells subjected to thermal stress.Results
Thermal stress increased the cytotoxic effect of both S. Typhimurium (P = 0.0001) and nonpathogenic E. coli K12 (P = 0.004) to Caco-2 cells, and resulted in greater susceptibility of cell monolayers to S. Typhimurium adhesion (P = 0.001). Thermal stress had no significant impact on inflammatory cytokines released by Caco-2 cells, although exposure to S. Typhimurium resulted in greater than 80% increase in production of IL-6 and IL-8. Blocking S. Typhimurium with anti-ShdA antibody prior to exposure of Salmonella decreased adhesion (P = 0.01) to non-stressed and thermal-stressed Caco-2 cells. Pre-exposure of Caco-2 cells to L. rhamnosus GG significantly reduced Salmonella-induced cytotoxicity (P = 0.001) and Salmonella adhesion (P = 0.001) to Caco-2 cells during thermal stress, while L. gasseri had no effect.Conclusion
Results suggest that thermal stress increases susceptibility of intestinal epithelial Caco-2 cells to Salmonella adhesion, and increases the cytotoxic effect of Salmonella during infection. Use of L. rhamnosus GG as a probiotic may reduce the severity of infection during epithelial cell stress. Mechanisms by which thermal stress increases susceptibility to S. Typhimurium colonization and by which L. rhamnosus GG limits the severity of infection remain to be elucidated. 相似文献11.
José María Moreno-Navarrete Francisco Ortega María Moreno Wifredo Ricart José Manuel Fernández-Real 《Diabetologia》2014,57(9):1957-1967
Aims/hypothesis
Adipose tissue from obese and insulin-resistant individuals showed altered expression of several iron-related genes in a recent study, suggesting that iron might have an important role in adipogenesis. To investigate this possible role, we aimed to characterise the effects of iron on adipocyte differentiation.Methods
Intracellular iron deficiency was achieved using two independent approaches: deferoxamine administration (20 and 100 μmol/l) and transferrin knockdown (TF KD). The effects of added FeSO4, holo-transferrin and palmitate were studied during human and 3T3-L1 adipocyte differentiation. Finally, the relationship between iron-related and mitochondrial-related genes was investigated in human adipose tissue.Results
Most adipose tissue iron-related genes were predominantly expressed in adipocytes compared with stromal vascular cells. Of note, transferrin gene and protein expression increased significantly during adipocyte differentiation. Both deferoxamine and TF KD severely blunted adipocyte differentiation in parallel with increased inflammatory mRNAs. These effects were reversed in a dose-dependent manner after iron supplementation. Palmitate administration also led to a state of functional intracellular iron deficiency, with decreased Tf gene expression and iron uptake during adipocyte differentiation, which was reversed with transferrin co-treatment. On the other hand, iron in excess impaired differentiation, but this antiadipogenic effect was less pronounced than under iron chelation. Of interest, expression of several genes involved in mitochondrial biogenesis occurred in parallel with expression of iron-related genes both during adipogenesis and in human adipose tissue.Conclusions/interpretation
Precise and fine-tuned iron availability is essential to achieve optimal adipocyte differentiation, possibly modulating adipocyte mitochondrial biogenesis. 相似文献12.
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P. G. Larsson T. Lakshmikanth E. Svedin C. King M. Flodström-Tullberg 《Diabetologia》2013,56(4):867-874
Aims/hypothesis
Enterovirus (e.g. Coxsackie B virus serotypes [CVBs]) infections may be associated with development of type 1 diabetes. Studies conducted in several European countries have, however, shown an inverse correlation between the incidence of type 1 diabetes and the prevalence of enterovirus infections. These findings could in part be explained by an extension of the poliovirus hypothesis, suggesting that the absence of maternally transferred antibodies protecting offspring from early infection increases the risk for diabetes development. Experimental evidence supporting this hypothesis in type 1 diabetes is, however, lacking. As maternally transferred protection from infection is a crucial component of the extended poliovirus hypothesis, we here tested the hypothesis that previously infected females transfer protection against infection and diabetes to offspring.Methods
The induction of CVB-specific maternal antibodies and transfer of protection from virus infection, replication and development of virus-induced diabetes to offspring was assessed using NOD and Socs1-transgenic NOD mice.Results
Infected mice produced neutralising antibodies to CVB. Offspring from infected females were positive for neutralising antibodies and were strongly protected from both infection and experimental diabetes.Conclusions/interpretation
Our study shows that maternally transferred antibodies protect offspring from enterovirus infection and virus-induced diabetes. This suggests that the absence of maternally provided protection increases the risk for severe outcomes after an enterovirus infection in offspring. Moreover, our findings may have implications for the design of prospective studies aimed at investigating the possible role of enterovirus infections in the aetiology of human type 1 diabetes. 相似文献14.
Stine C. Jacobsen Linn Gillberg Jette Bork-Jensen Rasmus Ribel-Madsen Ester Lara Vincenzo Calvanese Charlotte Ling Agustin F. Fernandez Mario F. Fraga Pernille Poulsen Charlotte Brøns Allan Vaag 《Diabetologia》2014,57(6):1154-1158
Aims/hypothesis
The association between low birthweight (LBW) and risk of developing type 2 diabetes may involve epigenetic mechanisms, with skeletal muscle being a prime target tissue. Differential DNA methylation patterns have been observed in single genes in muscle tissue from type 2 diabetic and LBW individuals, and we recently showed multiple DNA methylation changes during short-term high-fat overfeeding in muscle of healthy people. In a randomised crossover study, we analysed genome-wide DNA promoter methylation in skeletal muscle of 17 young LBW men and 23 matched normal birthweight (NBW) men after a control and a 5 day high-fat overfeeding diet.Methods
DNA methylation was measured using Illumina’s Infinium BeadArray covering 27,578 CpG sites representing 14,475 different genes.Results
After correction for multiple comparisons, DNA methylation levels were found to be similar in the LBW and NBW groups during the control diet. Whereas widespread DNA methylation changes were observed in the NBW group in response to high-fat overfeeding, only a few methylation changes were seen in the LBW group (χ2, p?<?0.001).Conclusions/interpretation
Our results indicate lower DNA methylation plasticity in skeletal muscle from LBW vs NBW men, potentially contributing to understanding the link between LBW and increased risk of type 2 diabetes. 相似文献15.
J. A. SoRelle T. Itoh H. Peng M. A. Kanak K. Sugimoto S. Matsumoto M. F. Levy M. C. Lawrence B. Naziruddin 《Diabetologia》2013,56(4):814-824
Aims/hypothesis
Beta cell death triggered by pro-inflammatory cytokines plays a central role in the pathogenesis of type 1 diabetes and loss of transplanted islets. The nuclear factor κB (NF-κB) signalling pathway is a key regulator of beta cell stress response, survival and apoptosis. Withaferin A (WA), a steroidal lactone derived from Withania somnifera, has been demonstrated to be a potent, safe, anti-inflammatory molecule that can inhibit NF-κB signalling. Therefore, we evaluated the ability of WA to protect mouse and human islets from the damaging effects of pro-inflammatory cytokines in vitro and following intraportal transplantation.Methods
Mouse and human islets were treated with a cytokine cocktail, and NF-κB activation was measured by immunoblots, p65 nuclear translocation and chromatin immunoprecipitation of p65-bound DNA. Intraportal transplantation of a marginal mass of syngeneic mouse islets was performed to evaluate the in vivo protective effect of WA.Results
Treatment with WA substantially improved islet engraftment of syngeneic islets (83% for infusion with 200 islets + WA; 0% for 200 islets + vehicle) in a mouse model of diabetes, compared with marginal graft controls with superior islet function in WA-treated mice confirmed by glucose tolerance test. Treatment of human and mouse islets with WA prevented cytokine-induced cell death, inhibited inflammatory cytokine secretion and protected islet potency.Conclusions
WA was shown to be a strong inhibitor of the inflammatory response in islets, protecting against cytokine-induced cell damage while improving survival of transplanted islets. These results suggest that WA could be incorporated as an adjunctive treatment to improve islet transplant outcome. 相似文献16.
Ruth Estela Gravato Rowlands Christiane Asturiano Ristori Alice A. Ikuno Maria Luisa Barbosa Miyoko Jakabi Bernadette Dora Gombossy de Melo Franco 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(6):461-467
Salmonella is the most common etiological agent of
cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread
of Salmonella spp., which has become multi-drug resistant and
potentially more pathogenic, have increased the concern with this pathogen. In
this study, 237 Salmonella spp., associated or not with
foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis,
were tested for antimicrobial susceptibility and the presence of the virulence
genes spvC, invA, sefA and
pefA. Of the isolates, 46.8% were sensitive to all
antimicrobials and 51.9% were resistant to at least one antimicrobial
agent. Resistance to more than one antimicrobial agent was observed in
10.5% of the strains. The highest rates of resistance were observed for
streptomycin (35.9%) and nalidixic acid (16.9%).
No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin,
ciprofloxacin and imipenem. The invA gene was detected in all
strains. Genes spvC and pefA were found in
48.1% and 44.3% of strains, respectively. The gene
sefA was detected in 31.6% of the strains and only
among S. Enteritidis. Resistance and virulence determinants
were detected in Salmonella strains belonging to several
serotypes. The high rates of antibiotic-resistance in strains isolated from
poultry products demonstrate the potential risk associated with the consumption
of these products and the need to ensure good food hygiene practices from farm
to table to reduce the spread of pathogens relevant to public health. 相似文献
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Yee Soo Chae Jong Gwang Kim Sang Kyun Sohn Su Jeong Lee Byung Woog Kang Joon Ho Moon Jae Yong Park Seong Woo Jeon Han-Ik Bae Gyu Seog Choi Soo-Han Jun 《Journal of cancer research and clinical oncology》2011,137(4):705-713
Background
Since apoptosis plays a key role in cancer progression, the present study analyzed the polymorphisms of apoptosis-related genes and their impact on survival after curative resection in patients with colorectal cancer.Materials and methods
Three hundred and seventy-seven patients were enrolled in the present study. The genomic DNA was extracted from fresh colorectal mucosal tissue, and 15 SNPs of 12 apoptosis-related genes were determined using a Sequenom MassARRAY system.Results
During the median follow-up of 41.8 (range, 1.1?C85.5) months patients alive at last follow-up, 65 relapses and 57 deaths occurred. Among the target polymorphisms, the RIPK1 rs2272990 in a dominant model and the CASP7 rs2227310 in a recessive model of the minor allele were associated with survival in a log-rank test. Moreover, the GA+AA genotype of the RIPK1 rs2272990 and the GG genotype of the CASP7 rs2227310 were significantly correlated with a worse disease-free (hazard ratio [HR]?=?2.093; P?=?0.007 and HR?=?2.641; 0.002, respectively) and disease-specific survival (HR?=?2.222; P?=?0.013 and HR?=?2.247; P?=?0.031, respectively) in a multivariate survival analysis.Conclusion
The RIPK1 and CASP7 polymorphisms can be considered as possible prognostic markers for survival after curative resection in patients with colorectal cancer. 相似文献20.
Hyun-Chul Lee Jong Gwang Kim Yee Soo Chae Sang Kyun Sohn Byung Woog Kang Joon Ho Moon Seong Woo Jeon Myung-Hoon Lee Kyoung-Hoon Lim Jin Young Park Gyu Seog Choi Soo-Han Jun 《Journal of cancer research and clinical oncology》2010,136(7):1073-1078