A rapid and reliable method for the clonal isolation of Acanthamoeba from environmental samples

Acanthamoeba are abundant in a wide range of environments, and some species are responsible for cutaneous infections, keratitis, and granulomatous amoebic encephalitis (GAE). The conventional detection and isolation of amoeba from clinical and environmental samples involves sampling and culture on non-nutrient Ágar medium. Although efficient, this system requires several transfers in order to eliminate contaminants, and is not appropriate for the isolation of individual amoeba from samples with a biodiverse community. In this study we propose an alternative method for the isolation of monocystic clones of Acanthamoeba. The propose method involves sampling, enrichment, encystment induction, and direct cysts micromanipulation and culture on Ágar plates

Genetic variation among South Brazilian accessions of Lippia alba Mill. (Verbenaceae) detected by ISSR and RAPD markers

Twenty-seven accessions of Lippia alba Mill. collected in Rio Grande do Sul state, Brazil, were analysed by ISSR and RAPD markers to evaluate their genetic variability and relationships. Six ISSR primers and four RAPD primers generated 120 amplified fragments, most of which were polymorphics. The overall genetic variability among accessions was very high when compared with other plant species. The hierarchical analysis of molecular data (UPGMA) showed low relationship between accessions, and no grouping between accessions of the same chemotype. Canonical functions allowed identifying some variables related with the chemical characteristics of the essential oils. Both ISSR and RAPD markers were efficient to address the genetic diversity of L. alba, and may contribute to the conservation and breeding of this increasingly important aromatic and medicinal species

Comparison of PCR-based molecular markers for the characterization of Proteus mirabilis clinical isolates

Proteus mirabilis is one of the most important pathogens associated with complicated urinary tract infections (acute pyelonephritis, bladder infections, kidney stones) and bacteremia, affecting patients with anatomical abnormalities, immunodeficiency, and long-term urinary catheterization. For epidemiological purposes, various molecular typing methods, such as pulse-field gel electrophoresis (PFGE) or ribotyping, have been developed for this pathogen. However, these methods are labor intensive and time-consuming. We evaluated the discriminatory power of several PCR-based fingerprinting methods (RAPD, ISSR, ERIC-PCR, BOX-PCR and rep-PCR) for P. mirabilis clinical isolates. Typing patterns and clustering analysis indicated that RAPD, BOX-PCR and ERIC-PCR differentiated P. mirabilis strains from Escherichia coli, Hafnia alvei, and Morganella morganii. With the exception of rep-PCR, the methods gave medium to high discriminatory efficiency in P. mirabilis. In general, the results obtained with RAPD, BOX-PCR and ERIC-PCR were in good agreement. We concluded that a combination of ERIC-PCR and BOX-PCR results is a rapid and reliable alternative for discrimination among P. mirabilis clinical isolates, contributing to epidemiological studies

The Effect of Monoterpenes on Swarming Differentiation and Haemolysin Activity in Proteus mirabilis

Urinary tract infection by Proteus mirabilis depends on several virulence properties that are coordinately regulated with swarming differentiation. Here we report the antibacterial and anti-swarming effect of seventeen terpenoids, and the effect of subinhibitory concentrations of five selected terpenoids on swarming, biofilm formation and haemolysin activity. The results showed that all the terpenes evaluated, particularly oxygenated terpenoids, inhibited P. mirabilis with MIC values ranging between 3 and 10 mg/L. Moreover, citral, citronellol and geraniol effectively inhibit P. mirabilis swarming in a dose dependent manner, reducing swimming/swarming cell differentiation and haemolysin activity at 1/10 MIC concentration. The inhibition of P. mirabilis swarming and virulence factor expression by selected oxygenated terpenoids suggest that essential oils with high concentration of these compounds have the potential to be developed as products for preventing P. mirabilis infections