The Role of the AggR Regulon in the Virulence of the Shiga Toxin-Producing Enteroaggregative Escherichia coli Epidemic O104:H4 Strain in Mice

An O104:H4 Shiga toxin (Stx)-producing enteroaggregative Escherichia coli (EAEC) strain caused a large outbreak of bloody diarrhea and the hemolytic uremic syndrome in 2011. We previously developed an ampicillin (Amp)-treated C57BL/6 mouse model to measure morbidity (weight loss) and mortality of mice orally infected with the prototype Stx-EAEC strain C227-11. Here, we hypothesized that mice fed C227-11 cured of the pAA plasmid or deleted for individual genes on that plasmid would display reduced virulence compared to animals given the wild-type (wt) strain. C227-11 cured of the pAA plasmid or deleted for the known pAA-encoded virulence genes aggR, aggA, sepA or aar were fed to Amp-treated C57BL/6 mice at doses of 1010-1011CFU. Infected animals were then either monitored for morbidity and lethality for 28 days or euthanized to determine intestinal pathology and colonization levels at selected times. The pAA-cured, aggR, and aggA mutants of strain C227-11 all showed reduced colonization at various intestinal sites. However, the aggR mutant was the only mutant attenuated for virulence as it showed both reduced morbidity and mortality. The aar mutant showed increased expression of the aggregative adherence fimbriae (AAF) and caused greater systemic effects in infected mice when compared to the C227-11 wt strain. However, unexpectedly, both the aggA and aar mutants displayed increased weight loss compared to wt. The sepA mutant did not exhibit altered morbidity or mortality in th...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research

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CONCLUSIONS: Xyloglucan/gelose plus ORS was effective and safe in treating acute diarrhea in children. PMID: 33028102 [PubMed - as supplied by publisher]
Source: Expert Review of Gastroenterology and Hepatology - Category: Gastroenterology Tags: Expert Rev Gastroenterol Hepatol Source Type: research
Conclusions: (1) Data at our center suggests at least a regional implementation gap in GBS screening and IAP. (2) The decline in the resistance rate ofE. coli for all antimicrobial substances might indicate that the reduction of prenatal antibiotics use is beneficial and that neonatal antibiotic stewardship programs should include pregnant women as well.What is Known:• GBS screening and intrapartum antibiotic prophylaxis led to a 32%-reduction in GBS disease in Germany with a 0.75 (92:122) ratio of early-onset disease to late-onset disease in 2009–2010.• Prenatal antibiotic use might increase the risk of E....
Source: European Journal of Pediatrics - Category: Pediatrics Source Type: research
Conclusion: The incidence of atypical haemolytic uraemic syndrome in the Czech paediatric population corresponds to the reported incidence in Europe. We detected the unusually high rate ofCFHR1/CFHR3 deletions associated with anti-complement factor H antibodies in Czech paediatric patients. Treatment by eculizumab led to superior outcomes and prevention of the disease relapses compared with plasma exchange therapy. Our results may help to understand the polygenic nature of atypical haemolytic uraemic syndrome as a disease that results from a combination of various risk factors.What is Known:•Atypical haemolytic uraemi...
Source: European Journal of Pediatrics - Category: Pediatrics Source Type: research
Authors: Arab JP, Dirchwolf M, Álvares-da-Silva MR, Barrera F, Benítez C, Castellanos-Fernandez M, Castro-Narro G, Chavez-Tapia N, Chiodi D, Cotrim H, Cusi K, de Oliveira CPMS, Díaz J, Fassio E, Gerona S, Girala M, Hernandez N, Marciano S, Masson W, Mendez-Sanchez N, Leite N, Lozano A, Padilla M, Panduro A, Paraná R, Parise E, Perez M, Poniachik J, Restrepo JC, Ruf A, Silva M, Tagle M, Tapias M, Torres K, Vilar-Gomez E, Costa Gil JE, Gadano A, Arrese M Abstract Non-alcoholic fatty liver disease (NAFLD) currently represents an epidemic worldwide. NAFLD is the most frequently diagnosed chr...
Source: Annals of Hepatology - Category: Gastroenterology Tags: Ann Hepatol Source Type: research
Publication date: Available online 9 October 2020Source: The Journal of Allergy and Clinical Immunology: In PracticeAuthor(s): Manuel Jorge Rial, Marcela Valverde, Victoria del Pozo, Francisco Javier González-Barcala, Carlos Martínez-Rivera, Xavier Muñoz, José María Olaguibel, Vicente Plaza, Elena Curto, Santiago Quirce, Pilar Barranco, Javier Domínguez-Ortega, Joaquin Mullol, César Picado, Antonio Valero, Irina Bobolea, Ebymar Arismendi, Paula Ribó, Joaquín Sastre
Source: The Journal of Allergy and Clinical Immunology: In Practice - Category: Allergy & Immunology Source Type: research
This study investigated antibacterial-producing Streptomyces isolated from the gut of estuarine fish Chanos chanos, emphasizing screening for the producer of peptide-containing antibacterial compounds. Eighteen isolates were found during preliminary screening, in which four isolates showed the best antibacterial activities. Based on the morphological, physiological, and biochemical characterization, as well as 16S rRNA partial sequencing, all of the four isolates belonged to Streptomyces. Three isolates were suspected as novel isolate candidates based on homology presentations and phylogenetic tree analysis. Disk-diffusion...
Source: International Journal of Microbiology - Category: Microbiology Tags: Int J Microbiol Source Type: research
Trump plans in-person rally on Monday as next presidential debate cancelled; Europe records 100,000 daily cases for first time; Canada at ‘tipping point’. Follow latest updatesEurope: Spain declares emergency in Madrid as Berlin emerges as hotspotUK workers to get two-thirds of wages if firms told to shutAustralia: Is Victoria ready to come out of lockdown?US presidential debate cancelled – live updatesSee all our coronavirus coverage5.42amBSTMy colleagueLuke Henriques-Gomes has this story giving you a summary of the main Covid-19 stories from Australia.A main point of the day has beenVictoria ’s pr...
Source: Guardian Unlimited Science - Category: Science Authors: Tags: Coronavirus outbreak Infectious diseases Science World news France Trump administration Donald Trump Source Type: news
After being epidemic in China, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) infection has rapidly spread in many countries as a global pandemic, with the number of affected cases dramatically increasing worldwide on a daily basis. Although the median age of hospitalized patients with confirmed infection is usually more advanced 1, with older age reported to be associated to higher mortality rate 2, physiological adaptations occurring during pregnancy have been claimed to be potentially responsible for a more severe respiratory disease, thus leading to higher rates of maternal and fetal complications 3,4.
Source: European Journal of Obstetrics, Gynecology, and Reproductive Biology - Category: OBGYN Authors: Tags: Correspondence Source Type: research
WHO emergencies chiefwarns ‘there are no new answers’ as cases surge globally. This blog has now closed. Follow our latest blog belowCoronavirus – latest updates12.58amBSTWe are closing this live blog now, but you can stay up to date on all the latest news, including a press conference from Victoria at 11am, hosted by Daniel Andrews, on our new blog below:Related:Coronavirus live news: France sets daily record 20,000 cases; Australian state of Victoria reports 14 new infections12.43amBSTI ’ve just got some clarification on the “positive test result” reported for Goodna, near Ipswich, wes...
Source: Guardian Unlimited Science - Category: Science Authors: Tags: Coronavirus outbreak World news UK news US news Australia news Science Infectious diseases Source Type: news
In April 2011, a food-poisoning outbreak caused by Escherichia coli O111 occurred in Toyama, Japan. A total of 326 patients had complaints of gastrointestinal symptoms, such as abdominal pain and bloody diarrhea. Thirty-four of these cases were diagnosed with hemolytic–uremic syndrome (HUS). In addition, 21 of these 34 HUS cases developed encephalopathy and five cases eventually died due to brain edema, encephalopathy, and HUS.
Source: International Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Case Report Source Type: research
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