scholarly journals Molecular epidemiology of clinical and environmental isolates of theCryptococcus neoformansspecies complex reveals a high genetic diversity and the presence of the molecular type VGII mating type a in Colombia

2006 ◽  
Vol 6 (4) ◽  
pp. 625-635 ◽  
Author(s):  
Patricia Escandón ◽  
Adriana Sánchez ◽  
Marcela Martínez ◽  
Wieland Meyer ◽  
Elizabeth Castañeda
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
Mating Type ◽  
Type A ◽  
Environmental Isolates ◽  
Molecular Type ◽  
High Genetic Diversity

HIV Type 1 Molecular Epidemiology in Cuba: High Genetic Diversity, Frequent Mosaicism, and Recent Expansion of BG Intersubtype Recombinant Forms

2006 ◽  
Vol 22 (8) ◽  
pp. 724-733 ◽  
Author(s):  
Lissette Pérez ◽  
Michael M. Thomson ◽  
María J. Bleda ◽  
Carlos Aragonés ◽  
Zoila González ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
High Genetic Diversity ◽  
Hiv Type 1

Genetic Diversity and Population Structure of Phyllosticta citriasiana in China

2020 ◽  
Author(s):  
Yibing Zeng ◽  
Tao Xiong ◽  
Bei Liu ◽  
Elma Carstens ◽  
Xiangling Chen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Mating Type ◽  
Tan Spot ◽  
Long Distance ◽  
High Genetic Diversity ◽  
Geographic Population ◽  
Sexual And Asexual Reproduction ◽  
Geographic Populations ◽  
Genetic Clusters

Phyllosticta citriasiana is the causal agent of citrus tan spot, an important pomelo disease in Asia. At present, there is little or no information on the epidemiology or population structure of P. citriasiana. Using simple sequence repeat (SSR) markers, 94 isolates obtained from three pomelo production regions in southern/southeastern China were analyzed. The analyses showed high genetic diversity in each of the three geographic populations. A STRUCTURE analysis revealed two genetic clusters among the 94 isolates, one geographic population was dominated by genotypes in one cluster while the other two geographic populations were dominated by genotypes of the second cluster. P. citriasiana has a heterothallic mating system with two idiomorphs, MAT1-1 and MAT1-2. Analyses using mating type-specific primers revealed that both mating types were present in all three geographic populations, and in all three populations the mating type ratios were in equilibrium. Although the sexual stage of the fungus has not been discovered yet, analyses of allelic associations indicated evidence for sexual and asexual reproduction within and among populations. Despite the observed genetic differentiation among the three geographic populations, evidence for long-distance gene flow was found.

scholarly journals Increasing Incidences and Clonal Diversity of Methicillin-Resistant Staphylococcus aureus in the Nordic Countries - Results From the Nordic MRSA Surveillance

2021 ◽  
Vol 12 ◽  
Author(s):  
Andreas Petersen ◽  
Kjersti W. Larssen ◽  
Frode W. Gran ◽  
Hege Enger ◽  
Sara Hæggman ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Staphylococcus Aureus ◽  
Molecular Epidemiology ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Diversity ◽  
Nordic Countries ◽  
High Genetic Diversity ◽  
Molecular Surveillance ◽  
Methicillin Resistant ◽  
Country Specific

Methicillin-resistant Staphylococcus aureus (MRSA) is notifiable in Denmark, Finland, Iceland, Norway and Sweden. The prevalence of MRSA in this region has been low for many years, but all five countries experience increasing numbers of new cases. The aim of the study was to describe the molecular epidemiology in the Nordic countries 2009-2016. Numbers of new cases of MRSA from 1997 to 2016 were compared, and a database containing information on spa-type and place of residence or acquisition, for all new MRSA isolates from 2009 to 2016 was established. A website was developed to visualize the geographic distribution of the spa-types. The incidence of new MRSA cases increased in all Nordic countries with Denmark having 61.8 new cases per 100,000 inhabitants in 2016 as the highest. The number of new cases 2009 to 2016 was 60,984. spa-typing revealed a high genetic diversity, with a total of 2,344 different spa-types identified. The majority of these spa-types (N = 2,017) were found in 1-10 cases. The most common spa-types t127/CC1, t223/CC22, and t304/CC6:8 increased significantly in all Nordic countries during the study period, except for Iceland, while spa-type t002/CC5 decreased in the same four countries. The trends of other common spa-types were different in each of the Nordic countries. The Nordic countries were shown to share similar trends but also to have country-specific characteristics in their MRSA populations. A continued increasing numbers of MRSA will challenge the surveillance economically. A more selected molecular surveillance will probably have to be employed in the future.

scholarly journals Molecular Epidemiology Characteristics of Brucella Abortus Strains in China and Their Relationships With World Lineages

2020 ◽  
Author(s):  
Xu-Ming Wang ◽  
Zhongzhi Zhao ◽  
Miao Wang ◽  
Buyun Cui ◽  
Zhiguo Liu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
Brucella Abortus ◽  
Variable Number Tandem Repeat ◽  
Northern China ◽  
Variable Number ◽  
Snp Analysis ◽  
High Genetic Diversity ◽  
Geographic Origins ◽  
Epidemic Area

Abstract Background Brucella abortus is a facultative intracellular Gram-negative bacterium that causes chronic persistent infections in humans and livestock. In this study, conventional bio-typing, multiple-locus variable-number tandem repeat analysis (MLVA), and whole-genome sequencing-single-nucleotide polymorphism (WGS-SNP) were used to investigate the molecular epidemiology characteristics of Brucella abortus strains in China and their relationships to world lineages. Results A total of 100 strains were collected from 1953 to 2013, suggesting that B. abortus circulated in China in the past five decades. Moreover, most strains were mainly distributed in the Northwest areas, suggest that provinces in the Northwest were a dominant epidemic area of this disease. During this period, seven biovars were found, indicating that B. abortus had a high diversity of biovars and it is also a potential reason for the disease ongoing spread in the Northern provinces. Strains have high genetic diversity, and bruce07 is the most helpful locus for genotyping of this population. Moreover, 17 MLVA-11 genotypes were found; 13 of them are of known genotypes and four are unassigned genotypes, indicating that B. abortus in this study had several geographic origins. Still, strains from unassigned genotypes may originate from China. Many shared MLVA-16 genotypes were observed in strains from the same provinces in Northern China, which confirmed a B. abortus brucellosis outbreak within Northern regions. WGS-SNP analysis showed that eight Chinese strains formed a ladder-like phylogram (C. Ⅶ) with strains from nine countries, including Uganda, Iraq, Russia, Georgia, Spain, Italy, Egypt, Mongolia, and China; suggest that strains were introduced to these countries from a single source. Conclusions Chinese B. abortus strains had high biovars and genetic diversity as well as represent characteristics of multiple geographic origins, and B. abortus strains from several mainly epidemic areas were closely related to strains from Russia and Mongolia; frequent animal (cattle) trade and exchanges may promote this process. We will provide new and valuable information to strengthening surveillance and control of B. abortus brucellosis in China.

scholarly journals Mating Type Idiomorphs, Heterothallism and High Genetic Diversity in Venturia carpophila, Cause of Peach Scab

2020 ◽  
Author(s):  
Clive Bock ◽  
Carolyn Young ◽  
Minling Zhang ◽  
Chunxian Chen ◽  
Phillip Michael Brannen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating Type ◽  
Population Genetic ◽  
Pleckstrin Homology Domain ◽  
Gene Encoding ◽  
Population Genetic Analysis ◽  
High Genetic Diversity ◽  
Genetic Diversity And Structure ◽  
Mating Type Gene ◽  
Type Gene

Scab (caused by Venturia carpophila) is a major disease affecting peach in the eastern U.S.A. The aims of the study were to characterize the mating type loci in V. carpophila, determine whether they are in equilibrium, and to assess the population genetic diversity and structure of the pathogen. The mating type gene MAT1-1-1 was identified in isolate JP3-5 in an available genome sequence, and the MAT1-2-1 gene was PCR amplified from isolate PS1-1, thus indicating a heterothallic structure. Mating type loci structure were consistent with those of other Venturia species (V. effusa and V. inaequalis): the mating type gene is positioned between APN2 encoding a DNA lyase and a gene encoding a Pleckstrin homology domain. Primers designed to each of the mating type genes and a reference gene TUB2 were used as a multiplex PCR reaction to screen a population (n = 81) of V. carpophila from various locations in the eastern U.S.A. Mating types in five of the nine populations studied were in equilibrium. Among the 81 isolates, there were 69 multilocus genotypes. A population genetic analysis of the populations with >10 individuals (four populations) showed them to be genetically diverse. Linkage disequilibrium was found in five of nine populations with ≥4 isolates. A discriminant analysis of principal components indicated three genetic clusters, although extensive admixture was observed. Mating type identification in V. carpophila provides a basis for understanding reproductive methods of the pathogen and can be a basis for further studies of genetics of the peach scab pathogen.

scholarly journals crAssphage is not associated with diarrhoea and has high genetic diversity

2016 ◽  
Vol 144 (16) ◽  
pp. 3549-3553 ◽  
Author(s):  
Y. Y. LIANG ◽  
W. ZHANG ◽  
Y. G. TONG ◽  
S. P. CHEN
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
Healthy Adults ◽  
Infants And Children ◽  
Chinese Patients ◽  
Genotype 1 ◽  
High Genetic Diversity ◽  
Viral Loads ◽  
Positive Ratio ◽  
Genotype 2

SUMMARYcrAssphage is a newly discovered gut bacteriophage. However, its pathogenicity and molecular epidemiology in humans are as yet unclear. In this study, we investigated the association between crAssphage and diarrhoea, as well as the molecular epidemiology of crAssphage in Chinese patients from our hospital. Our results indicated that there were no significant differences in the crAssphage-positive ratio and viral loads in faecal supernatants between adults with diarrhoea and healthy adults. Of infants and children with diarrhoea, 2·8% were found to be crAssphage-positive, including two infants aged <1 month. Markedly, of all confirmed crAssphage-positive strains, 100% had the ORF00039 deletion and 77·8% had low identity of ORF00018 compared to crAssphage (GenBank accession no. NC_024711, designated genotype 1). Thus, crAssphage was not associated with diarrhoea and most strains of crAssphage in Chinese patients (designated genotype 2) were characterized by the ORF00039 deletion and low identity of ORF00018.

Human rhinovirus infections in hospitalized children: clinical, epidemiological and virological features

2015 ◽  
Vol 144 (2) ◽  
pp. 346-354 ◽  
Author(s):  
D. N. TRAN ◽  
Q. D. TRINH ◽  
N. T. K. PHAM ◽  
T. M. H. PHAM ◽  
M. T. HA ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Epidemiology ◽  
Influenza A ◽  
Viral Infections ◽  
Respiratory Infections ◽  
Human Rhinovirus ◽  
Hospitalized Children ◽  
High Genetic Diversity ◽  
Tropical Regions ◽  
Syncytial Virus

SUMMARYMolecular epidemiology and clinical impact of human rhinovirus (HRV) are not well documented in tropical regions. This study compared the clinical characteristics of HRV to other common viral infections and investigated the molecular epidemiology of HRV in hospitalized children with acute respiratory infections (ARIs) in Vietnam. From April 2010 to May 2011, 1082 nasopharyngeal swabs were screened for respiratory viruses by PCR. VP4/VP2 sequences of HRV were further characterized. HRV was the most commonly detected virus (30%), in which 70% were diagnosed as either pneumonia or bronchiolitis. Children with single HRV infections presented with significantly higher rate of hypoxia than those infected with respiratory syncytial virus or parainfluenza virus (PIV)-3 (12·4% vs. 3·8% and 0%, respectively, P < 0·05), higher rate of chest retraction than PIV-1 (57·3% vs. 34·5%, P = 0·028), higher rate of wheezing than influenza A (63·2% vs. 42·3%, P = 0·038). HRV-C did not differ to HRV-A clinically. The genetic diversity and changes of types over time were observed and may explain the year-round circulation of HRV. One novel HRV-A type was discovered which circulated locally for several years. In conclusion, HRV showed high genetic diversity and was associated with significant morbidity and severe ARIs in hospitalized children.

Sign in / Sign up

Export Citation Format

Share Document