scholarly journals Global phylogenomics of multidrug-resistant Salmonella enterica serotype Kentucky ST198

2019 ◽  
Vol 5 (7) ◽  
Author(s):  
Jane Hawkey ◽  
Simon Le Hello ◽  
Benoît Doublet ◽  
Sophie A. Granier ◽  
Rene S. Hendriksen ◽  
...  

Salmonella enterica serotype Kentucky can be a common causative agent of salmonellosis, usually associated with consumption of contaminated poultry. Antimicrobial resistance (AMR) to multiple drugs, including ciprofloxacin, is an emerging problem within this serotype. We used whole-genome sequencing (WGS) to investigate the phylogenetic structure and AMR content of 121 S. e nterica serotype Kentucky sequence type 198 isolates from five continents. Population structure was inferred using phylogenomic analysis and whole genomes were compared to investigate changes in gene content, with a focus on acquired AMR genes. Our analysis showed that multidrug-resistant (MDR) S. enterica serotype Kentucky isolates belonged to a single lineage, which we estimate emerged circa 1989 following the acquisition of the AMR-associated Salmonella genomic island (SGI) 1 (variant SGI1-K) conferring resistance to ampicillin, streptomycin, gentamicin, sulfamethoxazole and tetracycline. Phylogeographical analysis indicates this clone emerged in Egypt before disseminating into Northern, Southern and Western Africa, then to the Middle East, Asia and the European Union. The MDR clone has since accumulated various substitution mutations in the quinolone-resistance-determining regions (QRDRs) of DNA gyrase (gyrA) and DNA topoisomerase IV (parC), such that most strains carry three QRDR mutations which together confer resistance to ciprofloxacin. The majority of AMR genes in the S. e nterica serotype Kentucky genomes were carried either on plasmids or SGI structures. Remarkably, each genome of the MDR clone carried a different SGI1-K derivative structure; this variation could be attributed to IS26-mediated insertions and deletions, which appear to have hampered previous attempts to trace the clone’s evolution using sub-WGS resolution approaches. Several different AMR plasmids were also identified, encoding resistance to chloramphenicol, third-generation cephalosporins, carbapenems and/or azithromycin. These results indicate that most MDR S. e nterica serotype Kentucky circulating globally result from the clonal expansion of a single lineage that acquired chromosomal AMR genes 30 years ago, and has continued to diversify and accumulate additional resistances to last-line oral antimicrobials. This article contains data hosted by Microreact.

2019 ◽  
Author(s):  
Jane Hawkey ◽  
Simon Le Hello ◽  
Benoît Doublet ◽  
Sophie Granier ◽  
Rene Hendriksen ◽  
...  

Salmonella enterica serotype Kentucky (S. Kentucky) can be a common causative agent of salmonellosis, usually associated with consumption of contaminated poultry. Antimicrobial resistance (AMR) to multiple drugs, including ciprofloxacin, is an emerging problem within this serotype. We used whole-genome sequencing (WGS) to investigate the phylogenetic structure and AMR content of 121 S. Kentucky ST198 isolates from five continents. Population structure was inferred using phylogenomic analysis and whole genomes were compared to investigate changes in gene content, with a focus on acquired AMR genes. Our analysis showed that multidrug resistant (MDR) S. Kentucky isolates belonged to a single lineage, which we estimate emerged circa 1989 following the acquisition of the AMR-associated Salmonella genomic island 1 (variant SGI1-K) conferring resistance ampicillin, streptomycin, gentamicin, sulfamethoxazole, and tetracycline. Phylogeographic analysis indicates this clone emerged in Egypt before disseminating into Northern, Southern and Western Africa, then to the Middle East, Asia and the European Union. The MDR clone has since accumulated various substitution mutations in the quinolone resistance determining regions (QRDR) of DNA gyrase (gyrA) and DNA topoisomerase (parC), such that most strains carry three QRDR mutations which together confer resistance to ciprofloxacin. The majority of AMR genes in the S. Kentucky genomes were carried either on plasmids or SGI structures. Remarkably, each genome carried a different SGI1-K derivative structure; this variation could be attributed to IS26-mediated insertions and deletions, which appear to have hampered previous attempts to trace the clone's evolution using sub-WGS resolution approaches. Several different AMR plasmids were also identified, encoding resistance to chloramphenicol, third-generation cephalosporins, carbapenems, and/or azithromycin. These results indicate that most MDR S. Kentucky circulating globally result from the clonal expansion of a single lineage that acquired chromosomal AMR genes 30 years ago, and has continued to diversify and accumulate additional resistances to last-line oral antimicrobials.


2021 ◽  
Vol 7 (10) ◽  
Author(s):  
Winnie W. Y. Lee ◽  
Jennifer Mattock ◽  
David R. Greig ◽  
Gemma C. Langridge ◽  
David Baker ◽  
...  

Salmonella enterica serovar Infantis is the fifth most common Salmonella serovar isolated in England and Wales. Epidemiological, genotyping and antimicrobial-resistance data for S . enterica Infantis isolates were used to analyse English and Welsh demographics over a 5 year period. Travel cases associated with S . enterica Infantis were mainly from Asia, followed by cases from Europe and North America. Since 2000, increasing numbers of S . enterica Infantis had multidrug resistance determinants harboured on a large plasmid termed ‘plasmid of emerging S . enterica Infantis’ (pESI). Between 2013 and 2018, 42 S . enterica Infantis isolates were isolated from humans and food that harboured resistance determinants to multiple antimicrobial classes present on a pESI-like plasmid, including extended-spectrum β-lactamases (ESBLs; bla CTX-M-65). Nanopore sequencing of an ESBL-producing human S . enterica Infantis isolate indicated the presence of two regions on an IncFIB pESI-like plasmid harbouring multiple resistance genes. Phylogenetic analysis of the English and Welsh S . enterica Infantis population indicated that the majority of multidrug-resistant isolates harbouring the pESI-like plasmid belonged to a single clade maintained within the population. The bla CTX-M-65 ESBL isolates first isolated in 2013 comprise a lineage within this clade, which was mainly associated with South America. Our data, therefore, show the emergence of a stable resistant clone that has been in circulation for some time in the human population in England and Wales, highlighting the necessity of monitoring resistance in this serovar.


Author(s):  
Juan Du ◽  
Yang Liu ◽  
Tao Pei ◽  
Ming-Rong Deng ◽  
Honghui Zhu

A novel Gram-stain-negative, aerobic and rod-shaped bacterial strain designated as 6D45AT was isolated from mangrove soil and characterized using a polyphasic taxonomic approach. Strain 6D45AT was found to grow at 10–37 °C (optimum, 28 °C), at pH 6.0–9.0 (optimum, 7.0) and in 0–5 % (w/v) NaCl (optimum, 2%). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6D45AT fell into the genus Salipiger and shared 99.1 % identity with the closest type strain Salipiger pacificus CGMCC 1.3455T and less than 97.2 % identity with other type strains of this genus. The 34.8 % digital DNA–DNA hybridization (dDDH) and 88.3 % average nucleotide identity (ANI) values between strain 6D45AT and the closest relative above were well below recognized thresholds of 70 % DDH and 95–96 % ANI for species definition, implying that strain 6D45AT should represent a novel genospecies. The phylogenomic analysis indicated that strain 6D45AT formed an independent branch distinct from reference strains. The predominant cellular fatty acid of strain 6D45AT was summed feature 8 (C18 : 1  ω6c and/or C18 : 1  ω7c, 66.9 %); the polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids, two unidentified glycolipids and an unknown lipid; the respiratory quinone was Q-10. The genomic DNA G+C content was 66.5 mol %. Based on the phenotypic and genotypic characteristics, strain 6D45AT is concluded to represent a novel species of the genus Salipiger , for which the name Salipiger mangrovisoli sp. nov., is proposed. The type strain of the species is 6D45AT (=GDMCC 1.1960T=KCTC 82334T). We also propose the reclassification of Paraphaeobacter pallidus as Salipiger pallidus comb. nov. and ‘ Pelagibaca abyssi ’ as a species of the genus Salipiger .


2021 ◽  
Author(s):  
Mattia Palmieri ◽  
Kelly L. Wyres ◽  
Caroline Mirande ◽  
Zhao Qiang ◽  
Ye Liyan ◽  
...  

Klebsiella pneumoniae is a frequent cause of nosocomial and severe community-acquired infections. Multidrug-resistant (MDR) and hypervirulent (hv) strains represent major threats, and tracking their emergence, evolution and the emerging convergence of MDR and hv traits is of major importance. We employed whole-genome sequencing (WGS) to study the evolution and epidemiology of a large longitudinal collection of clinical K. pneumoniae isolates from the H301 hospital in Beijing, China. Overall, the population was highly diverse, although some clones were predominant. Strains belonging to clonal group (CG) 258 were dominant, and represented the majority of carbapenemase-producers. While CG258 strains showed high diversity, one clone, ST11-KL47, represented the majority of isolates, and was highly associated with the KPC-2 carbapenemase and several virulence factors, including a virulence plasmid. The second dominant clone was CG23, which is the major hv clone globally. While it is usually susceptible to multiple antibiotics, we found some isolates harbouring MDR plasmids encoding for ESBLs and carbapenemases. We also reported the local emergence of a recently described high-risk clone, ST383. Conversely to strains belonging to CG258, which are usually associated to KPC-2, ST383 strains seem to readily acquire carbapenemases of different types. Moreover, we found several ST383 strains carrying the hypervirulence plasmid. Overall, we detected about 5 % of simultaneous carriage of AMR genes (ESBLs or carbapenemases) and hypervirulence genes. Tracking the emergence and evolution of such strains, causing severe infections with limited treatment options, is fundamental in order to understand their origin and evolution and to limit their spread. This article contains data hosted by Microreact.


Author(s):  
Zhaobin Huang ◽  
Xiaomei Wei ◽  
Qiliang Lai ◽  
Shiyong Chen ◽  
Jianjun Yuan

Two marine bacterial strains, designated S2-4-21T and MT2-5-19, were isolated from two tidal flat sediments of cordgrass Spartina alterniflora and adjacent oyster culture field in Quanzhou bay, China, respectively. Both strains were Gram-staining-negative, rod-shaped, non-flagellated, non-motile, aerobic, had NaCl requirements, and contained carotenoid and flexirubin pigments. The 16S rRNA gene sequence similarity (99.8%), average nucleotide identity value (99.4%) and average amino acid identity (99.3%) between strain S2-4-21T and strain MT2-5-19 strongly supported that they belonged to a single species. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S2-4-21T and strain MT2-5-19 formed a monophyletic branch affiliated to the family Flavobacteriaceae , sharing similarities of 94.6% with Euzebyella marina CY01T and E. saccharophila 7SM30T, and of 94.1 and 92.8% with E. algicola MEBiC 12267T and Pseudozobellia thermophile DSM 19858T, respectively. Phylogenomic analysis based on the whole genome sequences supported that the two strains formed a distinct monophyletic clade within Flavobacteriaceae members, which was phylogenetically different from the clades of Euzebyella and Pseudozobellia . The major respiratory quinone was menaquinone MK-6. The major fatty acids (>10%) consisted of C15 : 0 iso, C16 : 0, summed feature 9 (C17 : 1 iso ω9c/C16 : 0 10-methyl) and C17 : 0 iso 3-OH. The polar lipid profiles of strain S2-4-21T and strain MT2-5-19 are identical, including phosphatidylethanolamine, four unidentified aminolipids, and four unidentified lipids. The genomic size was 4.9–5.0 Mb with genomic DNA G+C content of 41.5 mol%. Based on the above characteristics, strains S2-4-21T and MT2-5-19 represented a novel species of a novel genus in the family Flavobacteriaceae . Thus, Pareuzebyella sediminis gen. nov. sp. nov. is proposed with type strain S2-4-21T (=MCCC 1K03818T=KCTC 72152T), and another strain MT2-5-19 (=KCTC 72539=MCCC 1K03874).


2020 ◽  
Vol 70 (9) ◽  
pp. 5032-5039 ◽  
Author(s):  
Jae-Chan Lee ◽  
Kyung-Sook Whang

A Gram-stain-positive actinobacterial strain, designated ANK073T, was isolated from rhizosphere soil sampled at a spinach farming field in Shinan, Republic of Korea. Cells of strain ANK073T were found to be aerobic, non-motile, non-spore-forming rods which could grow at 20–40 °C (optimum, 30 °C), at pH 6.0–10.0 (optimum, pH 6.5–7.5) and at salinities of 0–4 % (w/v) NaCl (optimum, 0 % NaCl). The 16S rRNA gene sequence analysis showed that strain ANK073T belongs to the genus Agromyces with high sequence similarities to Agromyces humatus CD5T (98.8 %), Agromyces tardus SJ-23T (98.5 %) and Agromyces iriomotensis IY07-20T (98.4 %). The phylogenetic analysis indicated that strain ANK073T formed a distinct phyletic line in the genus Agromyces and the results of DNA–DNA relatedness and phylogenomic analysis based on whole genome sequences demonstrated that strain ANK073T could be separated from its closest relatives in the genus Agromyces . The strain contained 2,4-diaminobutylic acid, glycine, d-glutamic acid and d-alanine in the peptidoglycan. The predominant menaquinones were identified as MK-12 and MK-11, and the major fatty acids were anteiso-C17 : 0, anteiso-C15 :  0 and iso-C15:0. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The G+C content of the genome was determined to be 70.2 mol%. On the basis of its phenotypic and chemotaxonomic properties and the results of phylogenetic and phylogenomic analyses, strain ANK073T is considered to represent a novel species in the genus Agromyces , for which the name Agromyces humi sp. nov. is proposed. The type strain is ANK073T (=KACC 18683T=NBRC 111825T).


2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Ahmad-Kamal Ghazali ◽  
Su-Anne Eng ◽  
Jia-Shiun Khoo ◽  
Seddon Teoh ◽  
Chee-Choong Hoh ◽  
...  

Burkholderia pseudomallei , a soil-dwelling Gram-negative bacterium, is the causative agent of the endemic tropical disease melioidosis. Clinical manifestations of B. pseudomallei infection range from acute or chronic localized infection in a single organ to fulminant septicaemia in multiple organs. The diverse clinical manifestations are attributed to various factors, including the genome plasticity across B. pseudomallei strains. We previously characterized B. pseudomallei strains isolated in Malaysia and noted different levels of virulence in model hosts. We hypothesized that the difference in virulence might be a result of variance at the genome level. In this study, we sequenced and assembled four Malaysian clinical B. pseudomallei isolates, UKMR15, UKMPMC2000, UKMD286 and UKMH10. Phylogenomic analysis showed that Malaysian subclades emerged from the Asian subclade, suggesting that the Malaysian strains originated from the Asian region. Interestingly, the low-virulence strain, UKMH10, was the most distantly related compared to the other Malaysian isolates. Genomic island (GI) prediction analysis identified a new island of 23 kb, GI9c, which is present in B. pseudomallei and Burkholderia mallei , but not Burkholderia thailandensis . Genes encoding known B. pseudomallei virulence factors were present across all four genomes, but comparative analysis of the total gene content across the Malaysian strains identified 104 genes that are absent in UKMH10. We propose that these genes may encode novel virulence factors, which may explain the reduced virulence of this strain. Further investigation on the identity and role of these 104 proteins may aid in understanding B. pseudomallei pathogenicity to guide the design of new therapeutics for treating melioidosis.


2020 ◽  
Vol 70 (4) ◽  
pp. 2873-2878 ◽  
Author(s):  
María José León ◽  
Cristina Galisteo ◽  
Antonio Ventosa ◽  
Cristina Sánchez-Porro

A comparative taxonomic study of Spiribacter and Halopeptonella species was carried out using a phylogenomic approach based on comparison of the core genome, orthologous average nucleotide identity (OrthoANIu), Genome-to-Genome Distance Calculator (GGDC) and average amino acid identity (AAI). Phylogenomic analysis based on 976 core translated gene sequences obtained from their genomes showed that Spiribacter aquaticus SP30T, S. curvatus UAH-SP71T, S. roseus SSL50T, S. salinus M19-40T and Halopeptonella vilamensis DSM 21056T formed a robust cluster, clearly separated from the remaining species of closely related taxa. AAI between H. vilamensis DSM 21056T and the species of the genus Spiribacter was ≥73.1 %, confirming that all these species belong to the same single genus. On the other hand, S. roseus SSL50T and S. aquaticus SP30T showed percentages of OrthoANIu and digital DNA–DNA hybridization of 98.4 % and 85.3 %, respectively, while these values among those strains and the type strains of the other species of Spiribacter and H. vilamensis DSM 21056T were ≤80.8 and 67.8 %, respectively. Overall, these data show that S. roseus SSL50T and S. aquaticus SP30T constitute a single species and thus that S. aquaticus SP30T should be considered as a later, heterotypic synonym of S. roseus SSL50T based on the rules for priority of names. We propose an emended description of S. roseus , including the features of S. aquaticus . We also propose the reclassification of H. vilamensis as Spiribacter vilamensis comb. nov.


Author(s):  
Yang Liu ◽  
Tao Pei ◽  
Juan Du ◽  
Meijie Chao ◽  
Ming-Rong Deng ◽  
...  

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped and non-motile bacterial strain, designated as 4C16AT, was isolated from a tidal flat sediment and characterized by using a polyphasic taxonomic approach. Strain 4C16AT was found to grow at 10–40 °C (optimum, 28 °C), at pH 5.0–10.0 (optimum, pH 6.0–7.0) and in 0–6 % (w/v) NaCl (optimum, 1 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 4C16AT fell into the genus Roseibium , and shared the highest identity of 98.9 % with the closest type strain Roseibium suaedae KACC 13772T and less than 98.0 % identity with other type strains of recognized species within this genus. The phylogenomic analysis indicated that strain 4C16AT formed an independent branch within this genus. The 28.6 % digital DNA–DNA hybridization estimate and 85.0 % average nucleotide identity between strains 4C16AT and R. suaedae KACC 13772T were the highest, but still far below their respective threshold for species definition, implying that strain 4C16AT should represent a novel genospecies. The predominant cellular fatty acid was summed feature 8; the polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylmonomethylethanolamine; the respiratory quinones were Q-9 and Q-10. The genomic DNA G+C content was 59.8mol %. Based on phylogenetic analyses and phenotypic and chemotaxonomic characteristics, strain 4C16AT is concluded to represent a novel species of the genus Roseibium , for which the name Roseibium litorale sp. nov. is proposed. The type strain of the species is 4C16AT (=GDMCC 1.1932T=KACC 22078T). We also propose the reclassification of Labrenzia polysiphoniae as Roseibium polysiphoniae comb. nov. and ‘Labrenzia callyspongiae’ as Roseibium callyspongiae sp. nov.


Author(s):  
Soon Dong Lee ◽  
In Seop Kim ◽  
Hanna Choe ◽  
Ji-Sun Kim

A Gram-negative, facultatively anaerobic bacterium, designated SAP-6T, was isolated from sap extracted from Acer pictum in Mt. Halla in Jeju, Republic of Korea and its precise taxonomic status was determined by a polyphasic approach. Cells were non-sporulating, motile, short rods and showed growth at 4–37 °C, pH 6.0–8.0 and 0–4% NaCl. Phylogenomic analysis based on 92 core gene sequences showed that strain SAP-6T belonged to the family Pectobacteriaceae and formed a distinct clade between members of the genera Sodalis and Biostraticola with gene support index of 89. The closest phylogenetic neighbours were Biostraticola tofi DSM 19580T (97.3% 16S rRNA gene sequence similarity) and Sodalis praecaptivus HS1T (96.8%), with the average amino acid identity values of 75.3% and 74.0%, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminophospholipid. The major isoprenoid quinones were Q-7 and Q-8. The predominant fatty acids were C16:0, C17:0 cyclo and summed feature 3. The DNA G+C content was 57.0%. On the basis of data presented here, strain SAP-6T (=KCTC 52622T=DSM 104038T) represents a novel species of a new genus in the family Pectobacteriaceae , for which the name Acerihabitans arboris gen. nov., sp. nov. is proposed.


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