1.Characterisation of Escherichia coli isolates from the blood of haematological adult patients with bacteraemia: translocation from gut to blood requires the cooperation of multiple virulence factors.
Krawczyk B1, Śledzińska A, Szemiako K, Samet A, Nowicki B, Kur J. Eur J Clin Microbiol Infect Dis. 2015 Jun;34(6):1135-43. doi: 10.1007/s10096-015-2331-z. Epub 2015 Feb 6.
The aim of the study was to investigate whether there are unique pathotypes of Escherichia coli capable of transmission from the gastrointestinal tract to the vascular bed. The study included E. coli strains isolated from clinical materials collected from 115 patients suffering from haematologic malignancies diagnosed with bacteraemia. The genotyping techniques established that 89 E. coli isolates from the blood had the same genotype as the E. coli from the patient's bowel. The presence of 21 genes encoding virulence factors typical of various E. coli pathotypes and their relationship with the phylogenetic group was established. One-dimensional analysis showed that the focG gene occurred more frequently in the control bowel group, while the ampicillin-resistant afa/dr E. coli were associated with bacteraemia. Blood isolates with the highest occurrence of virulence factors belonged to pathogenic group B2 and non-pathogenic group A. The co-occurrence of multiple genes encoding papC, sfa, usp and cnf1 virulence factors probably predisposes E.
2.Serogroups and virulence genotypes of Escherichia coli isolated from patients with sepsis.
Ananias M1, Yano T. Braz J Med Biol Res. 2008 Oct;41(10):877-83.
Sixty strains of Escherichia coli, isolated by hemoculture, from septicemic Brazilian patients were evaluated to determine their serogroup and invasivity to Vero cells. All 60 patients died within 2 days of hospitalization. Furthermore, the molecular study of the following extraintestinal pathogenic E. coli-associated virulence factor (VF) genes was performed by PCR: i) adhesins: type 1 fimbria (fimH), S fimbria (sfaD/E), P fimbria (papC and papG alleles) and afimbrial adhesin (afaB/C); ii) capsule K1/K5 (kpsMTII); iii) siderophores: aerobactin (iucD), yersiniabactin (fyuA) and salmochelin (iroN); iv) toxins hemolysin (hlyA), necrotizing cytotoxic factor type 1 (cnf1) and secreted autotransporter toxin (sat); v) miscellaneous: brain microvascular endothelial cells invasion (ibeA), serum resistance (traT), colicin V (cvaC) and specific uropathogenic protein (usp). Our results showed that isolates are able to invade Vero cells (96.6%), differing from previous research on uropathogenic E.
3.Mitochondrial oxidative stress index, activity of redox-sensitive aconitase and effects of endogenous anti- and pro-oxidants on its activity in control, Alzheimer's disease and Swedish Familial Alzheimer's disease brain.
Raukas M1, Rebane R, Mahlapuu R, Jefremov V, Zilmer K, Karelson E, Bogdanovic N, Zilmer M. Free Radic Res. 2012 Dec;46(12):1490-5. doi: 10.3109/10715762.2012.728286. Epub 2012 Sep 27.
Efficient function of the mitochondrial respiratory chain and the citric acid cycle (CAC) enzymes is required for the maintenance of human brain function. A conception of oxidative stress (OxS) was recently advanced as a disruption of redox signalling and control. Mitochondrial OxS (MOxS) is implicated in the development of Alzheimer's disease (AD). Thus, both pro- and anti-oxidants of the human body and MOxS target primarily the redox-regulated CAC enzymes, like mitochondrial aconitase (MAc). We investigated the specific activity of the MAc and MOxS index (MOSI) in an age-matched control (Co), AD and Swedish Familial AD (SFAD) post-mortem autopsies collected from frontal cortex (FC) and occipital primary cortex (OC) regions of the brain. We also examined whether the mitochondrial neuroprotective signalling molecules glutathione, melatonin and 17-β-estradiol (17βE) and mitochondrially active pro-oxidant neurotoxic amyloid-β peptide can modulate the activity of the MAc isolated from FC and OC regions similarly or differently in the case of Co, AD and SFAD.
4.Diet-induced swine model with obesity/leptin resistance for the study of metabolic syndrome and type 2 diabetes.
Torres-Rovira L1, Astiz S, Caro A, Lopez-Bote C, Ovilo C, Pallares P, Perez-Solana ML, Sanchez-Sanchez R, Gonzalez-Bulnes A. ScientificWorldJournal. 2012;2012:510149. doi: 10.1100/2012/510149. Epub 2012 May 2.
The objective of the present study was to determine the suitability of a swine breed with leptin resistance and predisposition to obesity (the Iberian pig) as model for studies on metabolic syndrome and type 2 diabetes. Thus, six Iberian sows had ad libitum access to food enriched with saturated fat (SFAD group; food consumption was estimated to be 4.5 kg/animal/day) whilst four females acted as controls and were fed with 2 kg/animal/day of a commercial maintenance diet. After three months of differential feeding, SFAD animals developed central obesity, dyslipidemia, insulin resistance and impaired glucose tolerance, and elevated blood pressure; the five parameters associated with the metabolic syndrome. Thus, the current study characterizes the Iberian pig as a robust, amenable, and reliable translational model for studies on nutrition-associated diseases.