scholarly journals Cryptic prophages within a Streptococcus pyogenes genotype emm4 lineage

2020 ◽  
Author(s):  
Alex Remmington ◽  
Samuel Haywood ◽  
Julia Edgar ◽  
Luke R. Green ◽  
Thushan de Silva ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Type Species ◽  
Gene Loss ◽  
Content Type ◽  
Regulatory Modules ◽  
Link Type ◽  
Genes Encoding ◽  
Variable Extent ◽  
The Usa ◽  
The Uk

The major human pathogen Streptococcus pyogenes shares an intimate evolutionary history with mobile genetic elements, which in many cases carry genes encoding bacterial virulence factors. During recent whole-genome sequencing of a longitudinal sample of S. pyogenes isolates in England, we identified a lineage within emm4 that clustered with the reference genome MEW427. Like MEW427, this lineage was characterized by substantial gene loss within all three prophage regions, compared to MGAS10750 and isolates outside of the MEW427-like lineage. Gene loss primarily affected lysogeny, replicative and regulatory modules, and to a lesser and more variable extent, structural genes. Importantly, prophage-encoded superantigen and DNase genes were retained in all isolates. In isolates where the prophage elements were complete, like MGAS10750, they could be induced experimentally, but not in MEW427-like isolates with degraded prophages. We also found gene loss within the chromosomal island SpyCIM4 of MEW427-like isolates, although surprisingly, the SpyCIM4 element could not be experimentally induced in either MGAS10750-like or MEW427-like isolates. This did not, however, appear to abolish expression of the mismatch repair operon, within which this element resides. The inclusion of further emm4 genomes in our analyses ratified our observations and revealed an international emm4 lineage characterized by prophage degradation. Intriguingly, the USA population of emm4 S. pyogenes appeared to constitute predominantly MEW427-like isolates, whereas the UK population comprised both MEW427-like and MGAS10750-like isolates. The degraded and cryptic nature of these elements may have important phenotypic and fitness ramifications for emm4 S. pyogenes , and the geographical distribution of this lineage raises interesting questions on the population dynamics of the genotype.

scholarly journals Cryptic prophages within a Streptococcus pyogenes genotype emm4 lineage

2020 ◽  
Author(s):  
Alex Remmington ◽  
Samuel Haywood ◽  
Julia Edgar ◽  
Claire E. Turner
Keyword(s):  
Streptococcus Pyogenes ◽  
Gene Loss ◽  
Sequence Data ◽  
Genome Data ◽  
The United Kingdom ◽  
Ncbi Short Read Archive ◽  
Genes Encoding ◽  
Variable Extent ◽  
The Usa ◽  
The Uk

AbstractThe major human pathogen Streptococcus pyogenes shares an intimate evolutionary history with mobile genetic elements, which in many cases, carry genes encoding bacterial virulence factors. During recent whole genome sequencing of a longitudinal sample of S. pyogenes isolates in the United Kingdom, we identified a lineage within emm4 that clustered with the reference genome MEW427. Like MEW427, this lineage was characterised by substantial gene loss within all three prophage regions, compared to MGAS10750 and isolates outside of the MEW427-like lineage. Gene loss primarily affected lysogeny, replicatory and regulatory modules, and to a lesser and more variable extent, structural genes. Importantly, prophage-encoded superantigen and DNase genes were retained in all isolates. In isolates where the prophage elements were complete, like MGAS10750, they could be induced experimentally, but not in MEW427-like isolates with degraded prophages. We also found gene loss within the chromosomal island SpyCIM4 of MEW427-like isolates, although surprisingly, the SpyCIM4 element could not be experimentally induced in either MGAS10750-like or MEW427-like isolates. This did not, however, appear to abolish expression of the mismatch repair operon, within which this element resides. The inclusion of further emm4 genomes in our analyses ratified our observations and revealed an international emm4 lineage characterised by prophage degradation. Intriguingly, the USA population of emm4 S. pyogenes appeared to constitute predominantly MEW427-like isolates, whereas the UK comprised both MEW427-like and MGAS10750-like strains. The degradation and cryptic nature of these elements may have important phenotypic ramifications for emm4 S. pyogenes and the geographical distribution of this lineage raises interesting questions on the population dynamics of the genotype.Data summaryAll raw sequence data used in this study has been previously published and was obtained from NCBI short read archive. Accession numbers and citations for the genome data for each individual isolate is provided in Supplementary Table 1.

Kerstersia similis sp. nov., isolated from human clinical samples

2012 ◽  
Vol 62 (Pt_9) ◽  
pp. 2156-2159 ◽  
Author(s):  
Peter Vandamme ◽  
Evie De Brandt ◽  
Kurt Houf ◽  
Thierry De Baere
Keyword(s):  
Type Strain ◽  
Type Species ◽  
Gene Sequence ◽  
Clinical Samples ◽  
Content Type ◽  
Biochemical Characteristics ◽  
Link Type ◽  
Gene Sequence Analysis ◽  
The Usa ◽  
Kerstersia Gyiorum

Analysis of gyrB gene sequences, (GTG)5-primed PCR fingerprinting and biochemical characteristics determined in the Biolog GEN III microtest system were used to differentiate an unnamed Kerstersia species from Kerstersia gyiorum , the type and only named species in this genus. The inability to oxidize d-galacturonic and d-glucuronic acids and the ability to oxidize d-serine, along with gyrB gene sequence analysis and (GTG)5-PCR fingerprints, readily differentiated the unnamed taxon from the type species. Therefore, we propose to formally classify this unnamed taxon as Kerstersia similis sp. nov. with strain LMG 5890T ( = CCUG 46999T), isolated from a leg wound in the USA in 1983, as the type strain.

scholarly journals Transcriptomic analysis of cyanobacterial alkane overproduction reveals stress-related genes and inhibitors of lipid droplet formation

2020 ◽  
Vol 6 (10) ◽  
Author(s):  
Daisy B. Arias ◽  
Kevin A. Gomez Pinto ◽  
Kerry K. Cooper ◽  
Michael L. Summers
Keyword(s):  
Type Species ◽  
Transcriptomic Analysis ◽  
Lag Phase ◽  
Content Type ◽  
Link Type ◽  
Production Platform ◽  
Genes Encoding ◽  
Transcriptional Changes ◽  
Stress Related Genes ◽  
Upregulated Genes

The cyanobacterium Nostoc punctiforme can form lipid droplets (LDs), internal inclusions containing triacylglycerols, carotenoids and alkanes. LDs are enriched for a 17 carbon-long alkane in N. punctiforme , and it has been shown that the overexpression of the aar and ado genes results in increased LD and alkane production. To identify transcriptional adaptations associated with increased alkane production, we performed comparative transcriptomic analysis of an alkane overproduction strain. RNA-seq data identified a large number of highly upregulated genes in the overproduction strain, including genes potentially involved in rRNA processing, mycosporine-glycine production and synthesis of non-ribosomal peptides, including nostopeptolide A. Other genes encoding helical carotenoid proteins, stress-induced proteins and those for microviridin synthesis were also upregulated. Construction of N. punctiforme strains with several upregulated genes or operons on multi-copy plasmids resulted in reduced alkane accumulation, indicating possible negative regulators of alkane production. A strain containing four genes for microviridin biosynthesis completely lost the ability to synthesize LDs. This strain exhibited wild-type growth and lag phase recovery under standard conditions, and slightly faster growth under high light. The transcriptional changes associated with increased alkane production identified in this work will provide the basis for future experiments designed to use cyanobacteria as a production platform for biofuel or high-value hydrophobic products.

scholarly journals Sneathia amnii bacteraemia and chorioamnionitis leading to second trimester abortion: a case report

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Lien Gruwier ◽  
Aaron Sprenkels ◽  
Sofie Hulsbosch ◽  
Anne Vankeerberghen ◽  
Reinoud Cartuyvels
Keyword(s):  
Type Species ◽  
Culture Broth ◽  
Second Trimester ◽  
Trimester Abortion ◽  
Content Type ◽  
Link Type ◽  
First Case ◽  
Gene Sequence Analysis ◽  
The Usa ◽  
Septic Abortion

Background. Sneathia amnii (formerly designated as Leptotrichia amnionii ) was first described in 2002 in the USA. Members of the genus Sneathia can be part of the normal flora of the genitourinary tract, but have been implicated in invasive (mostly gynaecological) infections. Case presentation. To the best of our knowledge, here we present the first case of S. amnii infection in Belgium, in a young woman presenting with fever leading to second trimester septic abortion. Conclusions. Despite its pathogenicity, S. amnii remains an underrated cause of infections due to inherent difficulties with conventional laboratory methods. By extracting the bacterial DNA directly from the blood culture broth and performing a 16S ribosomal RNA gene sequence analysis we succeeded in identifying S. amnii as the most probable cause of the septic abortion in our patient.

scholarly journals Co-existence of multiple distinct lineages in Vibrio parahaemolyticus serotype O4:K12

2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Lin Zhao ◽  
Hongyou Chen ◽  
Xavier Didelot ◽  
Zhenpeng Li ◽  
Yinghui Li ◽  
...  
Keyword(s):  
Genome Analysis ◽  
Vibrio Parahaemolyticus ◽  
Type Species ◽  
Genomic Islands ◽  
Content Type ◽  
Pan Genome ◽  
Link Type ◽  
Gene Segregation ◽  
Strain Collection ◽  
The Usa

Vibrio parahaemolyticus is an important cause of foodborne gastroenteritis globally. Thermostable direct haemolysin (TDH) and the TDH-related haemolysin are the two key virulence factors in V. parahaemolyticus. Vibrio pathogenicity islands harbour the genes encoding these two haemolysins. The serotyping of V. parahaemolyticus is based on the combination of O and K antigens. Frequent recombination has been observed in V. parahaemolyticus , including in the genomic regions encoding the O and K antigens. V. parahaemolyticus serotype O4:K12 has caused gastroenteritis outbreaks in the USA and Spain. Recently, outbreaks caused by this serotype of V. parahaemolyticus have been reported in China. However, the relationships among this serotype of V. parahaemolyticus strains isolated in different regions have not been addressed. Here, we investigated the genome variation of the V. parahaemolyticus serotype O4:K12 using the whole-genome sequences of 29 isolates. We determined five distinct lineages in this strain collection. We observed frequent recombination among different lineages. In contrast, little recombination was observed within each individual lineage. We showed that the lineage of this serotype of V. parahaemolyticus isolated in America was different from those isolated in Asia and identified genes that exclusively existed in the strains isolated in America. Pan-genome analysis showed that strain-specific and cluster-specific genes were mostly located in the genomic islands. Pan-genome analysis also showed that the vast majority of the accessory genes in the O4:K12 serotype of V. parahaemolyticus were acquired from within the genus Vibrio . Hence, we have shown that multiple distinct lineages exist in V. parahaemolyticus serotype O4:K12 and have provided more evidence about the gene segregation found in V. parahaemolyticus isolated in different continents.

scholarly journals Emergence of ciprofloxacin-resistant Neisseria meningitidis B from asymptomatic carriers during an outbreak in Peru, 2017

2020 ◽  
Author(s):  
Eduardo Juscamayta-López ◽  
Faviola Valdivia ◽  
Sara Morales ◽  
Luis Fernando Donaires ◽  
Victor Fiestas-Solórzano ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Type Species ◽  
Acquired Resistance ◽  
Whole Genome Sequence ◽  
Fluoroquinolone Resistance ◽  
Content Type ◽  
Asymptomatic Carriers ◽  
Link Type ◽  
Ciprofloxacin Resistance ◽  
The Uk

Asymptomatic carriers are a likely source of transmission of Neisseria meningitidis to close contacts who are placed at a higher risk for invasive meningococcal disease (IMD). Although N. meningitidis ciprofloxacin-resistance is rare, there have been an increase in the reports of resistant isolates mainly in patients diagnosed with IMD, and little is known about the N. meningitidis ciprofloxacin-resistance in the carrier populations. We performed a pharyngeal carriage study during a 2017 military setting outbreak in Peru, caused by a ciprofloxacin-resistant N. meningitidis B. The isolates analysed came from two hospitalized cases and six asymptomatic carriers. Whole-genome sequence-based analysis was performed and showed that strains carrying the Thr91Ile mutation, in the gene encoding for subunit A of DNA gyrase (gyrA), were responsible for the fluoroquinolone resistance (MICs ≥0.256 µg ml−1) and were closely related to highly virulent strains from France, Norway and the UK. Phylogenetic analysis of the gyrA gene revealed that likely these Peruvian isolates acquired resistance through horizontal gene transfer from Neisseria lactamica . Our study provides evidence for the emergence and propagation of ciprofloxacin-resistant N. meningitidis B from asymptomatic carriers, and recommends the introduction of serogroup B vaccines for high-risk populations.

scholarly journals Domestication of Campylobacter jejuni NCTC 11168

2019 ◽  
Vol 5 (7) ◽  
Author(s):  
Ben Pascoe ◽  
Lisa K. Williams ◽  
Jessica K. Calland ◽  
Guillaume Meric ◽  
Matthew D. Hitchings ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Campylobacter Jejuni ◽  
Type Species ◽  
Reference Strain ◽  
Careful Consideration ◽  
Trait Variation ◽  
Content Type ◽  
Link Type ◽  
The Uk ◽  
Reference Strains

Reference and type strains of well-known bacteria have been a cornerstone of microbiology research for decades. The sharing of well-characterized isolates among laboratories has run in parallel with research efforts and enhanced the reproducibility of experiments, leading to a wealth of knowledge about trait variation in different species and the underlying genetics. Campylobacter jejuni strain NCTC 11168, deposited at the National Collection of Type Cultures in 1977, has been adopted widely as a reference strain by researchers worldwide and was the first Campylobacter for which the complete genome was published (in 2000). In this study, we collected 23 C . jejuni NCTC 11168 reference isolates from laboratories across the UK and compared variation in simple laboratory phenotypes with genetic variation in sequenced genomes. Putatively identical isolates, identified previously to have aberrant phenotypes, varied by up to 281 SNPs (in 15 genes) compared to the most recent reference strain. Isolates also display considerable phenotype variation in motility, morphology, growth at 37 °C, invasion of chicken and human cell lines, and susceptibility to ampicillin. This study provides evidence of ongoing evolutionary change among C. jejuni isolates as they are cultured in different laboratories and highlights the need for careful consideration of genetic variation within laboratory reference strains. This article contains data hosted by Microreact.

scholarly journals Isolation of the human-associated bla CTX-M-15-harbouring Klebsiella pneumoniae ST307 from a tortoise in the UK

2020 ◽  
Vol 2 (12) ◽  
Author(s):  
Geoffrey Foster ◽  
Manal AbuOun ◽  
Romain Pizzi ◽  
Bryn Tennant ◽  
Margaret McCall ◽  
...  
Keyword(s):  
Public Health ◽  
Klebsiella Pneumoniae ◽  
Type Species ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Public Health Concern ◽  
Emerging Pathogen ◽  
Content Type ◽  
Link Type ◽  
The Uk

The ST307 multidrug-resistant CTX-M-15-producing Klebsiella pneumoniae is an emerging pathogen, which has become disseminated worldwide in humans but is rarely reported from other reservoirs. We report the first isolation of K. pneumoniae from an animal in Europe and also from a reptile, a captive tortoise, whose death it probably caused. Detection of this clone from an animal adds to evidence of niche expansion in non-human environments, where it may amplify, recycle and become of greater public health concern.

scholarly journals Niche-specific adaptation of Lactobacillus helveticus strains isolated from malt whisky and dairy fermentations

2021 ◽  
Vol 7 (4) ◽  
Author(s):  
Yoshihiko Kido ◽  
Shintaro Maeno ◽  
Hiroki Tanno ◽  
Yuko Kichise ◽  
Yuh Shiwa ◽  
...  
Keyword(s):  
Type Species ◽  
Stop Codon ◽  
Lactobacillus Helveticus ◽  
Content Type ◽  
Link Type ◽  
Milk Fermentation ◽  
Genes Encoding ◽  
Metabolic Properties ◽  
Malt Whisky

Lactobacillus helveticus is a well characterized lactobacillus for dairy fermentations that is also found in malt whisky fermentations. The two environments contain considerable differences related to microbial growth, including the presence of different growth inhibitors and nutrients. The present study characterized L. helveticus strains originating from dairy fermentations (called milk strains hereafter) and malt whisky fermentations (called whisky strains hereafter) by in vitro phenotypic tests and comparative genomics. The whisky strains can tolerate ethanol more than the milk strains, whereas the milk strains can tolerate lysozyme and lactoferrin more than the whisky strains. Several plant-origin carbohydrates, including cellobiose, maltose, sucrose, fructooligosaccharide and salicin, were generally metabolized only by the whisky strains, whereas milk-derived carbohydrates, i.e. lactose and galactose, were metabolized only by the milk strains. Milk fermentation properties also distinguished the two groups. The general genomic characteristics, including genomic size, number of coding sequences and average nucleotide identity values, differentiated the two groups. The observed differences in carbohydrate metabolic properties between the two groups correlated with the presence of intact specific enzymes in glycoside hydrolase (GH) families GH1, GH4, GH13, GH32 and GH65. Several GHs in the milk strains were inactive due to the presence of stop codon(s) in genes encoding the GHs, and the inactivation patterns of the genes encoding specific enzymes assigned to GH1 in the milk strains suggested a possible diversification manner of L. helveticus strains. The present study has demonstrated how L. helveticus strains have adapted to their habitats.

scholarly journals Alterations in chromosomal genes nfsA, nfsB, and ribE are associated with nitrofurantoin resistance in Escherichia coli from the United Kingdom

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Yu Wan ◽  
Ewurabena Mills ◽  
Rhoda C.Y. Leung ◽  
Ana Vieira ◽  
Xiangyun Zhi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Type Species ◽  
Genetic Alterations ◽  
Uncomplicated Urinary Tract Infection ◽  
Insertion Sequences ◽  
Evolutionary Analysis ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
The Uk

Antimicrobial resistance in enteric or urinary Escherichia coli is a risk factor for invasive E. coli infections. Due to widespread trimethoprim resistance amongst urinary E. coli and increased bacteraemia incidence, a national recommendation to prescribe nitrofurantoin for uncomplicated urinary tract infection was made in 2014. Nitrofurantoin resistance is reported in <6% urinary E. coli isolates in the UK, however, mechanisms underpinning nitrofurantoin resistance in these isolates remain unknown. This study aimed to identify the genetic basis of nitrofurantoin resistance in urinary E. coli isolates collected from north west London and then elucidate resistance-associated genetic alterations in available UK E. coli genomes. As a result, an algorithm was developed to predict nitrofurantoin susceptibility. Deleterious mutations and gene-inactivating insertion sequences in chromosomal nitroreductase genes nfsA and/or nfsB were identified in genomes of nine confirmed nitrofurantoin-resistant urinary E. coli isolates and additional 11 E. coli isolates that were highlighted by the prediction algorithm and subsequently validated to be nitrofurantoin-resistant. Eight categories of allelic changes in nfsA, nfsB, and the associated gene ribE were detected in 12412 E. coli genomes from the UK. Evolutionary analysis of these three genes revealed homoplasic mutations and explained the previously reported order of stepwise mutations. The mobile gene complex oqxAB, which is associated with reduced nitrofurantoin susceptibility, was identified in only one of the 12412 genomes. In conclusion, mutations and insertion sequences in nfsA and nfsB were leading causes of nitrofurantoin resistance in UK E. coli . As nitrofurantoin exposure increases in human populations, the prevalence of nitrofurantoin resistance in carriage E. coli isolates and those from urinary and bloodstream infections should be monitored.

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