Effector and memory CD4+ and CD8+ T cells in the chronic infection process.

T cell memory in comparison with B cell memory is not well understood. This review focuses on CD8+ and CD4+ memory T cells. In this article we try to define memory cells and also present models of memory T cells formation. We would also like to delineate their differentiation into distinct subsets. Long-lived memory T cells consist in two main subsets: TCM and TEM. Recent studies have shown that not all cells considered to be memory cells differentiate into TCM and TEM, but a small proportion of theses cells exhibit naive cells phenotype. Memory T cells constitute a heterogeneous population of cells. In this study we lay stress on characteristic of main memory T cells subsets and their alleged participation in immune response upon reexposure to the Ag

Comparison of biofilm-producing Enterococcus faecalis, Enterococcus faecium, and unusual Enterococcus strains

The present study focused on determining the prevalence of biofilm-forming ability in Enterococ-cus faecalis, E. faecium, and unusual Enterococcus clinical isolates, and comparison of resistance and the prevalence of selected virulence factors among biofilm-positive strains. The ability to form biofilm was detected in 13.3% of E. faecalis, 90% of E. faecium, and 57.1% of unusual Enterococcus strains (p=0.026). All E. faecalis strains were susceptible to β-lactams, while 37.5% of unusual and all E. faecium isolates were resistant to these antibiotics. Resistance to gentamicin was detected in 75% of E. faecalis, 55.5% of E. faecium, and 25% of other strains; resistance to streptomycin in 25%, 83.3%, and 50%, respectively. Analysis of the virulence revealed that the enterococcal surface protein (esp) gene was found in all E. faecium, 75.0% of E. faecalis, and 37.5% of other strains; collagen adhesin gene (ace) in 100%, 25.0%, and 37.5%; and hyaluronidase gene (hyl) in 83.3%, 0%, and 37.5%, respectively. Analysis of the resistance and virulence patterns showed that E. faecium isolates had the greatest variety of virulence and resistance determinants, while the lowest variety was exhibited by unusual strains. These findings indicate that unusual biofilm-producing Enterococcus strains have lower resistance and virulence potency than E. faecalis and E. faecium. DOI: http://dx.doi.org/10.5281/zenodo.100083

Susceptibility, phenotypes of resistance, and extended-spectrum β-lactamases in Acinetobacter baumannii strains

Acinetobacter baumannii plays an increasing role in the pathogenesis of infections in humans. The bacilli are frequently isolated from patients treated in intensive care units. A growing resistance to antibiotics is leading to the emergence of strains that are multidrug-resistant and resistant to all available agents. The objective of this study was to assess susceptibility to antibiotics and to determine the presence and current level of the extended-spectrum β-lactamases (ESBLs) and attempt to isolate the Acinetobacter baumannii strain carrying the blaPER gene. A total of 51 strains of A. baumannii identified by phenotypic features were examined. That the strains belonged to the species was confirmed by the presence of the blaOXA-51-like; gene. A broth microdilution method was used for antibacterial susceptibility testing. The occurrence of ESBLs was determined using phenotypic double-disk synergy tests. The PCR technique was used to confirm the presence of the blaPER-1; gene encoding ESBL. The most active antibiotics were meropenem, cefepime and ampicillin/sulbactam, with susceptibility shown by 76.5%, 60.8% and 56.9% of the strains, respectively. The strains exhibited the highest resistance (> 75%) to piperacillin, tetracycline, ciprofloxacin and cefotaxime. Phenotypic tests revealed ESBL mechanism of resistance in approximately 20% of Acinetobacter baumannii isolates. However, the PCR technique did not confirm the presence of the blaPER-1; gene in any of the Acinetobacter baumannii strains examined in our hospital. Acinetobacter baumannii strains demonstrate considerable resistance to many groups of antibiotics. Our findings indicate the involvement of enzymes belonging to families other than PER β-lactamase in resistance to β-lactams in A. baumannii

The inflammatory reaction during chronic venous disease of lower limbs.

Chronic venous disease (CVD) is an insufficiency of distal veins caused by their partial or total obstruction, endothelial distension and functional disorders. Chronic venous disease of lower limbs is common problem and affects millions of people. In this article we suggest that inflammatory process is involved in the structural remodeling in venous valves and in the venous wall, leading to valvular incompetence and the development of varicose veins

Profiles of phenotype resistance to antibiotic other than β-lactams in Klebsiella pneumoniae ESBLs-producers, carrying blaSHV genes.

Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extended spectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinical specimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers named ESBL(+). The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extended spectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested

Profiles of phenotype resistance to antibiotic other than β-lactams in Klebsiella pneumoniae ESBLs-producers, carrying blaSHV genes

Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extendedspectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinicalspecimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers namedESBL(+). The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extendedspectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested

Evaluation of the memory CD4+ and CD8+ T cells homeostasis during chronic venous disease of lower limbs.

More and more is known about the role of venous wall abnormalities and valvular incompetence in the development of chronic venous disorders (CVD). Unfortunately detailed mechanisms of CVD pathophysiology are not well understood. Recent studies focus on involvement of the inflammatory process in the structural remodeling of venous valves and venous wall. The aim of this study is to investigate and to document the memory T cells homeostasis in CVD patients. In this study we present lymphocytic changes in blood from varicose veins in terms of total CD4+ and CD8+ T cells and their particular subsets of memory T cells: TN, TCM and TEM. Results suggest that immunological memory may be involved in the CVD development