scholarly journals Molecular Epidemiology Reveals Low Genetic Diversity among Cryptococcus neoformans Isolates from People Living with HIV in Lima, Peru, during the Pre-HAART Era

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 665
Author(s):  
Nathalie van de Wiele ◽  
Edgar Neyra ◽  
Carolina Firacative ◽  
Felix Gilgado ◽  
Carolina Serena ◽  
...  

Cryptococcosis, a mycosis presenting mostly as meningoencephalitis, affecting predominantly human immunodeficiency virus (HIV)-infected people, is mainly caused by Cryptococcus neoformans. The genetic variation of 48 C. neoformans isolates, recovered from 20 HIV-positive people in Lima, Peru, during the pre-highly active antiretroviral therapy (HAART) era, was studied retrospectively. The mating type of the isolates was determined by PCR, and the serotype by agglutination and CAP59-restriction fragment length polymorphism (RFLP). Genetic diversity was assessed by URA5-RFLP, PCR-fingerprinting, amplified fragment length polymorphism (AFLP), and multilocus sequence typing (MLST). All isolates were mating type alpha, with 39 molecular type VNI, seven VNII, corresponding to C. neoformans var. grubii serotype A, and two VNIII AD hybrids. Overall, the cryptococcal population from HIV-positive people in Lima shows a low degree of genetic diversity. In most patients with persistent cryptococcal infection, the same genotype was recovered during the follow-up. In four patients with relapse and one with therapy failure, different genotypes were found in isolates from the re-infection and from the isolate recovered at the end of the treatment. In one patient, two genotypes were found in the first cryptococcosis episode. This study contributes data from Peru to the ongoing worldwide population genetic analysis of Cryptococcus.

2005 ◽  
Vol 28 (2) ◽  
pp. 267-270 ◽  
Author(s):  
Michelle Mantovani Gonçalves ◽  
Manoel Victor Franco Lemos ◽  
Pedro Manoel Galetti Junior ◽  
Patrícia Domingues de Freitas ◽  
Manuel Antonio Andrade Furtado Neto

2005 ◽  
Vol 83 (10) ◽  
pp. 1322-1328 ◽  
Author(s):  
Yong-Bi Fu ◽  
Bruce E. Coulman ◽  
Yasas S.N. Ferdinandez ◽  
Jacques Cayouette ◽  
Paul M. Peterson

Fringed brome ( Bromus ciliatus L.) is found in native stands throughout a large area of North America. Little is known about the genetic diversity of this species. The amplified fragment length polymorphism (AFLP) technique was applied to assess the genetic diversity of 16 fringed brome populations sampled in Canada from the provinces of Alberta, British Columbia, Quebec, and Saskatchewan. Four AFLP primer pairs were employed to screen 82 samples with four to six samples per population and 83 polymorphic AFLP bands scored for each sample. The frequencies of the scored bands in all assayed samples ranged from 0.01 to 0.99 and averaged 0.53. Analysis of molecular variance revealed that 52.6% of the total AFLP variation resided among the 16 populations and 20.6% among the four provinces. The five Quebec populations appeared to be genetically the most diverse and distinct. The AFLP variability observed was significantly associated with the geographic origins of the fringed brome populations. These findings are useful for sampling fringed brome germplasm from natural populations for germplasm conservation and should facilitate the development of genetically diverse regional cultivars for habitat restoration and revegetation.


2008 ◽  
Vol 133 (4) ◽  
pp. 587-592 ◽  
Author(s):  
Joseph C. Kuhl ◽  
Veronica L. DeBoer

The genus Rheum L., commonly known as rhubarb, is composed of ≈60 species, primarily distributed throughout northern and central Asia. Rhubarb species have been used for medicinal purposes for thousands of years; however, it was not until the 18th century that the culinary use of petioles was first reported. Although the origin(s) of culinary rhubarb is not clear, it is thought that they originated from hybridization of rhubarb species originally brought to Europe for medicinal purposes. Most rhubarb cultivars lack pedigree information, and the genetic relationship among cultivars is largely unknown. Amplified fragment length polymorphism (AFLP) markers were generated for fingerprint analysis of 37 cultivars and four putative Rheum species accessions. Ten EcoRI and MseI primer combinations were analyzed for a total of 1400 scored polymorphisms, with an average of 140 polymorphisms per primer combination. Results show at least two clusters of related cultivars, as well as distantly related accessions. This study provides an estimate of rhubarb cultivar genetic diversity using AFLP analysis.


1996 ◽  
Vol 42 (11) ◽  
pp. 1121-1130 ◽  
Author(s):  
Bruce E. Urtz ◽  
Gerald H. Elkan

Symbiotic gene diversity and other measures of genetic diversity were examined in Bradyrhizobium isolates that form an effective symbiosis with peanut (Arachis hypogaea). Initially, restriction fragment length polymorphism (RFLP) analysis using a nitrogenase (nif) gene probe was performed on 33 isolates along with one Bradyrhizobium elkanii and two Bradyrhizobium japonicum strains. Considerable diversity was observed among the RFLP patterns of many of the isolates, especially those from South America. Some isolates, however, were found to have similar nif and subsequent nod (nodulation) gene RFLP patterns, indicating symbiotic gene relatedness. With some noted exceptions, symbiotic gene relatedness correlated with relatedness based on total DNA homology and ribotyping analyses. Symbiotic gene relatedness also correlated with symbiotic effectiveness. The RFLP and DNA homology analyses indicate that bradyrhizobia effective with peanut are genetically diverse and consist of at least three different species. This diversity, however, was not particularly evident with partial 16S rRNA gene sequencing. Sequences obtained from the isolates were very similar to each other as well as to sequences previously reported for other Bradyrhizobium strains.Key words: Bradyrhizobium, nif, peanut, restriction fragment length polymorphism, 16S rRNA.


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