Comparative genome analysis of three Group A Streptococcus dysgalactiae subsp. equisimilis strains isolated in Japan

2021 ◽  
Vol 70 (3) ◽  
Author(s):  
Haruka Ishihara ◽  
Kohei Ogura ◽  
Van An Nguyen ◽  
Tohru Miyohi-Akiyama ◽  
Shigefumi Okamoto ◽  
...  

Introduction . Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a β-hemolytic streptococcus that causes severe invasive streptococcal infections, especially in the elderly and people with underlying diseases. SDSE strains are primarily characterized by Lancefield group G or C antigens. Hypothesis/Gap Statement. We have previously reported the prevalence of Lancefield group A SDSE (GA-SDSE) strains in Japan and have analysed the draft genome sequences of these strains. As GA-SDSE is a rare type of SDSE, only one complete genome has been sequenced to date. Aim. The present study is focused on genetic characteristics of GA-SDSE strains. In order to examine molecular characteristics, we also tested growth inhibition of other streptococci by GA-SDSE. Methodology. We determined the complete genome sequences of three GA-SDSE strains by two new generation sequencing systems (short-read and long-read sequencing data). Using the sequences, we also conducted a comparative analysis of GA-SDSE and group C/G SDSE strains. In addition, we tested multiplex and quantitative PCRs targeting the GA-SDSE, group G SDSE, and S. pyogenes . Results. We found a group-specific conserved region in GA-SDSE strains that is composed of genes encoding predicted anti-bacteriocin and streptococcal lantibiotic (Sal) proteins. Multiplex and quantitative PCRs targeting the GA-SDSE-specific region were able to distinguish between GA-SDSE, other SDSE, and S. pyogenes strains. The growth of GA-SDSE was suppressed in the presence of group G SDSE, indicating a possible explanation for the low frequency of isolation of GA-SDSE. Conclusion. The comparative genome analysis shows that the genome of GA-SDSE has a distinct arrangement, enabling the differentiation between S. pyogenes , GA-SDSE, and other SDSE strains using our PCR methods.

2020 ◽  
Author(s):  
Dhiviya Prabaa Muthuirulandi Sethuvel ◽  
Shalini Anandan ◽  
Dhivya Murugan ◽  
Kalaiarasi Asokan ◽  
Karthick Vasudevan ◽  
...  

Azithromycin is increasingly being used for the treatment of shigellosis despite a lack of interpretative guidelines and with limited clinical evidence. The present study determined azithromycin susceptibility and correlated this with macrolide-resistance genes in Shigella spp. isolated from stool specimens in Vellore, India. The susceptibility of 332 Shigella isolates to azithromycin was determined using the disc diffusion method. Of these, 31 isolates were found to be azithromycin resistant. The azithromycin minimum inhibitory concentration (MIC) was determined using the broth microdilution method. In addition, isolates were screened for mphA and ermB genes using conventional PCR. Furthermore, an isolate that was positive for resistance genes was subjected to complete genome analysis, and was analysed for mobile genetic elements. The azithromycin MIC for the 31 resistant Shigella isolates ranged between 2 and 16 mg l−1. PCR results showed that a single isolate of Shigella sonnei carried a mphA gene. Complete genome analysis revealed integration of an IncFII plasmid into the chromosome of S. sonnei , which was also found to carry the following resistance genes: sul1, bla DHA1, qnrB4, mphA, tetR. Mutations in the quinolone-resistance-determining region (QRDR) were also observed. Additionally, prophages, insertion sequences and integrons were identified. The novel finding of IncFII plasmid integration into the chromosome of S. sonnei highlights the potential risk of Shigella spp. becoming resistance to azithromycin in the future. These suggests that it is imperative to monitor Shigella susceptibility and to study the resistance mechanism of Shigella to azithromycin considering the limited treatment choices for shigellosis.


2019 ◽  
Vol 69 (4) ◽  
pp. 998-1000 ◽  
Author(s):  
Wenjing Wu ◽  
Zhiyong Zong

The aim of this study was to further clarify the taxonomic relationship between the two recently described bacterial species, Lelliottia jeotgali sp. nov. and Lelliottia aquatilis sp. nov. Whole genome sequences of types strains of the two species are available for analysis. Average nucleotide identity (ANI) and in silico DNA–DNA hybridization (isDDH) values between the two type strains were determined. The ANI and isDDH values between type strains of the two species are 98.7 and 91.0 %, respectively, which are higher than cut-offs to define a bacterial species. It is therefore clear that the two species actually belong to the same species. The name of L.aquatilis was published at an earlier date than that of L. aquatilis . We therefore propose that L. aquatilis is a later heterotypic synonym of L. jeotgali .


2021 ◽  
Vol 70 (8) ◽  
Author(s):  
Haruka Ishihara ◽  
Kohei Ogura ◽  
Van An Nguyen ◽  
Tohru Miyoshi-Akiyama ◽  
Shigefumi Okamoto ◽  
...  

Author(s):  
Nay C. Dia ◽  
Johan Van Vaerenbergh ◽  
Cinzia Van Malderghem ◽  
Jochen Blom ◽  
Theo H. M. Smits ◽  
...  

This paper describes a novel species isolated in 2011 and 2012 from nursery-grown Hydrangea arborescens cultivars in Flanders, Belgium. After 4 days at 28 °C, the strains yielded yellow, round, convex and mucoid colonies. Pathogenicity of the strains was confirmed on its isolation host, as well as on Hydrangea quercifolia. Analysis using MALDI-TOF MS identified the Hydrangea strains as belonging to the genus Xanthomonas but excluded them from the species Xanthomonas hortorum . A phylogenetic tree based on gyrB confirmed the close relation to X. hortorum . Three fatty acids were dominant in the Hydrangea isolates: anteiso-C15 : 0, iso-C15 : 0 and summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c). Unlike X. hortorum pathovars, the Hydrangea strains were unable to grow in the presence of lithium chloride and could only weakly utilize d-fructose-6-PO4 and glucuronamide. Phylogenetic characterization based on multilocus sequence analysis and phylogenomic characterization revealed that the strains are close to, yet distinct from, X. hortorum . The genome sequences of the strains had average nucleotide identity values ranging from 94.35–95.19 % and in silico DNA–DNA hybridization values ranging from 55.70 to 59.40 % to genomes of the X. hortorum pathovars. A genomics-based loop-mediated isothermal amplification assay was developed which was specific to the Hydrangea strains for its early detection. A novel species, Xanthomonas hydrangeae sp. nov., is proposed with strain LMG 31884T (=CCOS 1956T) as the type strain.


2020 ◽  
Vol 70 (6) ◽  
pp. 3921-3923 ◽  
Author(s):  
Stephen L. W. On ◽  
William G. Miller ◽  
David J. Kelly ◽  
Peter Vandamme

Arcobacter anaerophilus was originally described as the first obligate anaerobe in this genus by Sasi Jyothsna et al. 2013. The complete genome sequence of the type strain of this species was determined and analysed. Genes characteristic for organisms capable of aerobic growth were identified, and the ability of the organism to grow under microaerobic and aerobic conditions was confirmed in two independent laboratories. The description of A. anaerophilus is thus emended and the wider ramifications of these findings are discussed.


2020 ◽  
Vol 70 (5) ◽  
pp. 3547-3552 ◽  
Author(s):  
Mari Tohya ◽  
Shin Watanabe ◽  
Tatsuya Tada ◽  
Htay Htay Tin ◽  
Teruo Kirikae

This study was conducted to clarify the taxonomic status of the species Pseudomonas fuscovaginae and Pseudomonas shirazica . Whole genome sequences for the type strains of P. fuscovaginae and P. shirazica were compared against the closely related type strains of the Pseudomonas putida group and the Pseudomonas fluorescens group species. Average nucleotide identity and digital DNA–DNA hybridization values between P. fuscovaginae LMG 2158T and Pseudomonas asplenii ATCC 23835T were 98.4 and 85.5 %, and between P. shirazica VM14T and Pseudomonas asiatica RYU5T were 99.3 and 95.3 %. These values were greater than recognized thresholds for bacterial species delineation, indicating that they belong to the same genomospecies, respectively. Therefore, P. fuscovaginae and P. shirazica should be reclassified as later heterotypic synonyms of P. asplenii and P. asiatica , respectively.


2020 ◽  
Vol 70 (3) ◽  
pp. 1903-1911 ◽  
Author(s):  
Nawarat Nantapong ◽  
Minenosuke Matsutani ◽  
Pawina Kanchanasin ◽  
Naoya Kataoka ◽  
Pawantree Paisrisan ◽  
...  

Strain N24T was isolated from soil contaminated with starling’s feces collected from Roi-Et province, Thailand. Cells of N24T were Gram-stain-positive rods, aerobic and non-spore-forming. N24T was positive for catalase, urease, citrate utilization, nitrate reduction and Methyl Red (MR) test but negative for oxidase, casein, gelatin liquefaction, tyrosine, Voges–Proskauer (VP) reaction and starch hydrolysis. Meso-diaminopimelic acid, rhamnose, ribose, arabinose and galactose were detected in its whole-cell hydrolysates. The results of the 16S rRNA gene sequence analysis indicated that N24T represented a member of the genus Corynebacterium . N24T was closely related to Corynebacterium glutamicum ATCC 13032T, with 99.0 % 16S rRNA gene sequence similarity. According to results obtained using in silico DNA–DNA hybridization approaches, N24T showed highest DNA–DNA relatedness (27.6 %) and average nucleotide identity (84.1 %) to Corynebacterium glutamicum ATCC 13032T. The DNA G+C content of N24T was 51.8 mol% (genome based). The major cellular fatty acids of N24T were C16 : 0, and C18 : 1ω9c. N24T had the nine isoprenes unit, MK-9(H2) as the predominant menaquinone. The predominant polar lipids were phosphatidylglycerol, phosphatidylinositol and diphosphatidylglycerol. Mycolic acids were also present. According to the complete genome sequence data, strain N24T and C. glutamicum ATCC 13032T are close phylogenetic neighbours, but have different genome characteristics. On the basis of the results of the genotypic and genomic studies and phenotypic characteristics including chemotaxonomy, strain N24T should be classified as representing a novel species of the genus Corynebacterium , for which the name Corynebacterium suranareeae sp. nov. is proposed. The type strain is N24T (TBRC 5845T=NBRC 113465T).


2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Lin Zhao ◽  
Hongyou Chen ◽  
Xavier Didelot ◽  
Zhenpeng Li ◽  
Yinghui Li ◽  
...  

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.


2019 ◽  
Vol 8 (10) ◽  
Author(s):  
James R. Winton ◽  
William N. Batts ◽  
Rachel L. Powers ◽  
Maureen K. Purcell

We report here the genome sequences of two index strains of Pacific salmon paramyxovirus isolated in 1982 and 1983 from adult salmon in Oregon. The isolates are most closely related to Atlantic salmon paramyxovirus, the type species of the genus Aquaparamyxovirus, but are sufficiently distinct to be considered two genotypes of a novel species.


2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Preetha Shibu ◽  
Frazer McCuaig ◽  
Anne L. McCartney ◽  
Magdalena Kujawska ◽  
Lindsay J. Hall ◽  
...  

As part of the ongoing studies with clinically relevant Klebsiella spp., we characterized the genomes of three clinical GES-5-positive ST138 strains originally identified as Klebsiella oxytoca. bla OXY gene, average nucleotide identity and phylogenetic analyses showed the strains to be Klebsiella michiganensis . Affiliation of the strains to ST138 led us to demonstrate that the current multi-locus sequence typing scheme for K. oxytoca can be used to distinguish members of this genetically diverse complex of bacteria. The strains encoded the kleboxymycin biosynthetic gene cluster (BGC), previously only found in K. oxytoca strains and one strain of Klebsiella grimontii . The finding of this BGC, associated with antibiotic-associated haemorrhagic colitis, in K. michiganensis led us to carry out a wide-ranging study to determine the prevalence of this BGC in Klebsiella spp. Of 7170 publicly available Klebsiella genome sequences screened, 88 encoded the kleboxymycin BGC. All BGC-positive strains belonged to the K. oxytoca complex, with strains of four ( K. oxytoca , K. pasteurii , K. grimontii , K. michiganensis ) of the six species of complex found to encode the complete BGC. In addition to being found in K. grimontii strains isolated from preterm infants, the BGC was found in K. oxytoca and K. michiganensis metagenome-assembled genomes recovered from neonates. Detection of the kleboxymycin BGC across the K. oxytoca complex may be of clinical relevance and this cluster should be included in databases characterizing virulence factors, in addition to those characterizing BGCs.


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