scholarly journals Molecular Epidemiology of Photobacterium damselae subsp. damselae Outbreaks in Marine Rainbow Trout Farms Reveals Extensive Horizontal Gene Transfer and High Genetic Diversity

2018 ◽  
Vol 9 ◽  
Author(s):  
Mateus S. Terceti ◽  
Ana Vences ◽  
Xosé M. Matanza ◽  
Inger Dalsgaard ◽  
Karl Pedersen ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rainbow Trout ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Molecular Epidemiology ◽  
High Genetic Diversity ◽  
Photobacterium Damselae ◽  
Trout Farms

scholarly journals Natural Transformation as a Mechanism of Horizontal Gene Transfer in Aliarcobacter butzleri

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 909
Author(s):  
Marina Bonifácio ◽  
Cristiana Mateus ◽  
Ana R. Alves ◽  
Emanuel Maldonado ◽  
Ana P. Duarte ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Natural Transformation ◽  
Stationary Phases ◽  
Genetic Material ◽  
Transformation Method ◽  
Biphasic System ◽  
Chromosomal Dna ◽  
High Genetic Diversity

Aliarcobacter butzleri is an emergent enteropathogen, showing high genetic diversity, which likely contributes to its adaptive capacity to different environments. Whether natural transformation can be a mechanism that generates genetic diversity in A. butzleri is still unknown. In the present study, we aimed to establish if A. butzleri is naturally competent for transformation and to investigate the factors influencing this process. Two different transformation procedures were tested using exogenous and isogenic DNA containing antibiotic resistance markers, and different external conditions influencing the process were evaluated. The highest number of transformable A. butzleri strains were obtained with the agar transformation method when compared to the biphasic system (65% versus 47%). A. butzleri was able to uptake isogenic chromosomal DNA at different growth phases, and the competence state was maintained from the exponential to the stationary phases. Overall, the optimal conditions for transformation with the biphasic system were the use of 1 μg of isogenic DNA and incubation at 30 °C under a microaerobic atmosphere, resulting in a transformation frequency ~8 × 10−6 transformants/CFU. We also observed that A. butzleri favored the transformation with the genetic material of its own strain/species, with the DNA incorporation process occurring promptly after the addition of genomic material. In addition, we observed that A. butzleri strains could exchange genetic material in co-culture assays. The presence of homologs of well-known genes involved in the competence in the A. butzleri genome corroborates the natural competence of this species. In conclusion, our results show that A. butzleri is a naturally transformable species, suggesting that horizontal gene transfer mediated by natural transformation is one of the processes contributing to its genetic diversity. In addition, natural transformation can be used as a tool for genetic studies of this species.

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

Genomic Analysis of Citrobacter Portucalensis Sb-2 Identifies a Phage Predation Driven Metalloid Resistance

2021 ◽  
Author(s):  
Yanshuang Yu ◽  
Zhenchen Xie ◽  
Jigang Yang ◽  
Jinxuan Liang ◽  
YuanPing Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Significant Role ◽  
Genome Analysis ◽  
Extreme Environments ◽  
Genomic Analysis ◽  
Resistant Bacterium ◽  
Bacterial Adaptation ◽  
Resistance Determinants

Abstract Bacterial adaptation to extreme environments is often mediated by horizontal gene transfer (HGT). At the same time, phage mediated HGT for conferring bacterial arsenite and antimonite resistance has not been documented before. In this study, a highly arsenite and antimonite resistant bacterium, C. portucalensis strain Sb-2, was isolated and subsequent genome analysis showed that putative arsenite and antimonite resistance determinants were flanked or embedded by prophages. We predict these phage-mediated resistances play a significant role in maintaining genetic diversity within the genus of Citrobacter and are responsible for endowing the corresponding resistances to C. portucalensis strain Sb-2.

scholarly journals Horizontal Gene Transfer Clarifies Taxonomic Confusion and Promotes the Genetic Diversity and Pathogenicity of Plesiomonas shigelloides

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Zhiqiu Yin ◽  
Si Zhang ◽  
Yi Wei ◽  
Meng Wang ◽  
Shuangshuang Ma ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Evolutionary Dynamics ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Content Type ◽  
Pan Genome ◽  
Long Time ◽  
Taxonomic Confusion

The taxonomic position of P. shigelloides has been the subject of debate for a long time, and until now, the evolutionary dynamics and pathogenesis of P. shigelloides were unclear. In this study, pan-genome analysis indicated extensive genetic diversity and the presence of large and variable gene repertoires. Our results revealed that horizontal gene transfer was the focal driving force for the genetic diversity of the P. shigelloides pan-genome and might have contributed to the emergence of novel properties. Vibrionaceae and Aeromonadaceae were found to be the predominant donor taxa for horizontal genes, which might have caused the taxonomic confusion historically. Comparative genomic analysis revealed the potential of P. shigelloides to cause intestinal and invasive diseases. Our results could advance the understanding of the evolution and pathogenesis of P. shigelloides, particularly in elucidating the role of horizontal gene transfer and investigating virulence-related elements.

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 High Genetic Diversity in Flavobacterium psychrophilum Isolates from Healthy Rainbow Trout (Oncorhynchus mykiss) Farmed in the Same Watershed, Revealed by Two Typing Methods

2020 ◽  
Vol 87 (2) ◽  
Author(s):  
Ségolène Calvez ◽  
Nora Navarro-Gonzalez ◽  
Charlène Siekoula-Nguedia ◽  
Catherine Fournel ◽  
Eric Duchaud
Keyword(s):  
Genetic Diversity ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Clonal Complex ◽  
Economic Losses ◽  
High Genetic Diversity ◽  
Content Type ◽  
Flavobacterium Psychrophilum ◽  
Sequence Types ◽  
Apparently Healthy

ABSTRACT Flavobacterium psychrophilum affects salmonid health worldwide and causes economic losses. The genetic diversity of the pathogen must be considered to develop control methods. However, previous studies have reported both high and low levels of genetic diversity. The present longitudinal study aimed at assessing the genetic diversity of F. psychrophilum at a small temporal and geographic scale. Four farms located on the same watershed in France were studied. Rainbow trout (Oncorhynchus mykiss) batches were monitored, and apparently healthy individuals were sampled over 1 year. A total of 288 isolates were recovered from fish organs (gills and spleen) and eggs. Pulsed field gel electrophoresis revealed high genetic diversity. Multilocus sequence typing performed on a selection of 31 isolates provided congruent results, as follows: 18 sequence types (STs) were found, of which 13 were novel. The mean gene diversity (H = 0.8413) was much higher than that previously reported for this host species, although the sampling was restricted to a single watershed and 1 year. Seven isolates out of 31 were assigned to clonal complex ST10 (CC-ST10), which is the predominant clonal complex in the main salmonid production areas. A split decomposition tree reflected a panmictic population. This finding is important for aquaculture veterinarians in their diagnostic procedure, as the choice of adequate antibiotic treatment is conditioned by the correct identification of the causative agent. Furthermore, this study expands our knowledge on genetic diversity required for the development of an effective vaccine against F. psychrophilum. IMPORTANCE The bacterium Flavobacterium psychrophilum is a serious pathogen in many fish species, especially salmonids, that is responsible for considerable economic losses worldwide. In order to treat infections and to develop vaccines, the genetic diversity of this bacterium needs to be known. We assessed the genetic diversity of F. psychrophilum isolates from apparently healthy rainbow trout raised in several fish farms in the same watershed in France. Two different genotyping methods revealed high diversity. The majority of isolates were unrelated to clonal complex sequence type 10 (CC-ST10), the clonal complex that is predominant worldwide and associated with disease in rainbow trout. In addition, we found 13 novel sequence types. These results suggest that a diverse subpopulation of F. psychrophilum may be harbored by rainbow trout.

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