scholarly journals Improved molecular characterization of the Klebsiella oxytoca complex reveals the prevalence of the kleboxymycin biosynthetic gene cluster

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.

2020 ◽  
Author(s):  
Preetha Shibu ◽  
Frazer McCuaig ◽  
Anne L. McCartney ◽  
Magdalena Kujawska ◽  
Lindsay J. Hall ◽  
...  

ABSTRACTAs part of ongoing studies with clinically relevant Klebsiella spp., we characterized the genomes of three clinical GES-5-positive strains originally identified as Klebsiella oxytoca. Average nucleotide identity and phylogenetic analyses showed the strains to be Klebsiella michiganensis. In addition to encoding GES-5, the strains encoded SHV-66, a β-lactamase not previously identified in K. michiganensis. The strains further encoded a range of virulence factors and the kleboxymycin biosynthetic gene cluster (BGC), previously only found in K. oxytoca strains and one strain of Klebsiella grimontii. This BGC, associated with antibiotic-associated haemorrhagic colitis, has not previously been reported in K. michiganensis, and this finding led us to carry out a wide-ranging study to determine the prevalence of this BGC in Klebsiella spp. Of 7,170 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 the 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.Data statementSupplementary data associated with this article are available from figshare.Data summaryDraft genome sequences for PS_Koxy1, PS_Koxy2 and PS_Koxy4 have been deposited with links to BioProject accession number PRJNA562720 in the NCBI BioProject database.IMPACT STATEMENTExtended analyses of the genomes of Klebsiella spp. have revealed the kleboxymycin biosynthetic gene cluster (BGC) is restricted to species of the Klebsiella oxytoca complex (K. oxytoca, K. michiganensis, K. pasteurii and K. grimontii). Species- and/or gene-specific differences in the cluster’s sequences may be relevant to virulence of K. oxytoca and related species. The finding of the kleboxymycin BGC in the preterm infant gut microbiota may have implications for disease presentation in a subset of neonates.


Author(s):  
Silvio Hering ◽  
Moritz K. Jansson ◽  
Michael E. J. Buhl

A novel species within the genus Eikenella is described, based on the phenotypical, biochemical and genetic characterization of a strain of a facultatively anaerobic, Gram-negative rod-shaped bacterium. Strain S3360T was isolated from the throat swab of a patient sampled during routine care at a hospital. Phylogenetic analyses (full-length 16S rRNA gene and whole-genome sequences) placed the strain in the genus Eikenella , separate from all recognized species but with the closest relationship to Eikenella longinqua (NML 02-A-017T). Eikenella is one of the genera in the HACEK group known to be responsible for rare cases of endocarditis in humans. Until the recent descriptions of Eikenella exigua , Eikenella halliae and Eikenella longinqua , Eikenella corrodens had been the only validly published species in this genus since its description as Bacteroides corrodens in 1958. Unlike these species, strain S3360T is able to metabolize carbohydrates (glucose). The average nucleotide identities of strain S3360T with E. longinqua (NML 02-A-017T) and E. corrodens (NCTC 10596T), the type species of the genus, were 90.5 and 84.7 %, respectively, and the corresponding genome-to-genome distance values were 41.3 and 29.0 %, respectively. The DNA G+C content of strain S3360T was 58.4 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3360T is considered to represent a novel species within the genus Eikenella , for which the name Eikenella glucosivorans sp. nov. is proposed. The type strain is S3360T (DSM 110714T=CCOS 1935T=CCUG 74293T). In addition, an emendation of the genus Eikenella is proposed to include species which are saccharolytic.


2020 ◽  
Vol 70 (4) ◽  
pp. 2288-2297 ◽  
Author(s):  
Sabrina Duranti ◽  
Gabriele Andrea Lugli ◽  
Alice Viappiani ◽  
Leonardo Mancabelli ◽  
Giulia Alessandri ◽  
...  

Two Bifidobacterium strains, i.e., 2176BT and 2177BT, were isolated from Golden-Headed Lion Tamarin (Leontopithecus chrysomelas) and Goeldi's monkey (Callimico goeldii). Isolates were shown to be Gram-positive, non-motile, non-sporulating, facultative anaerobic and d-fructose 6-phosphate phosphoketolase-positive. Phylogenetic analyses based on 16S rRNA sequences, multilocus sequences (including hsp60, rpoB, dnaJ, dnaG and clpC genes) and the core genome revealed that bifidobacterial strains 2176BT and 2177BT exhibit close phylogenetic relatedness to Bifidobacterium felsineum DSM 103139T and Bifidobacterium bifidum LMG 11041T, respectively. Further genotyping based on the genome sequence of the isolated strains combined with phenotypic analyses, clearly show that these strains are distinct from each of the type strains of the so far recognized Bifidobacterium species. Thus, Bifidobacterium cebidarum sp. nov. (2176BT=LMG 31469T=CCUG 73785T) and Bifidobacterium leontopitheci sp. nov. (2177BT=LMG 31471T=CCUG 73786T are proposed as novel Bifidobacterium species.


2014 ◽  
Vol 64 (Pt_11) ◽  
pp. 3655-3659 ◽  
Author(s):  
Sarah A. Hensley ◽  
Jong-Hyun Jung ◽  
Cheon-Seok Park ◽  
James F. Holden

Two heterotrophic hyperthermophilic strains, ES1T and CL1T, were isolated from Paralvinella sp. polychaete worms collected from active hydrothermal vent chimneys in the north-eastern Pacific Ocean. Both were obligately anaerobic and produced H2S in the presence of elemental sulfur and H2. Complete genome sequences are available for both strains. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strains are more than 97 % similar to most other species of the genus Thermococcus . Therefore, overall genome relatedness index analyses were performed to establish that these strains are novel species. For each analysis, strain ES1T was determined to be most similar to Thermococcus barophilus MPT, while strain CL1T was determined to be most similar to Thermococcus sp. 4557. The average nucleotide identity scores for these strains were 84 % for strain ES1T and 81 % for strain CL1T, genome-to-genome direct comparison scores were 23 % for strain ES1T and 47 % for strain CL1T, and the species identification scores were 89 % for strain ES1T and 88 % for strain CL1T. For each analysis, strains ES1T and CL1T were below the species delineation cut-off. Therefore, based on their whole genome sequences, strains ES1T and CL1T are suggested to represent novel species of the genus Thermococcus for which the names Thermococcus paralvinellae sp. nov. and Thermococcus cleftensis sp. nov. are proposed, respectively. The type strains are ES1T ( = DSM 27261T = KACC 17923T) and CL1T ( = DSM 27260T = KACC 17922T).


2020 ◽  
Vol 70 (5) ◽  
pp. 3278-3286 ◽  
Author(s):  
Sukriti Gujarati ◽  
Diptaraj Chaudhari ◽  
Ashwini Hagir ◽  
Mitesh Khairnar ◽  
Yogesh Shouche ◽  
...  

A novel bacterial strain, designated TOUT106T, was isolated from the surface of a tomato. The cells were rod-shaped, Gram-negative, encapsulated and non-motile. Strain TOUT106T grows best at 28 °C and pH 7.0 and can tolerate up to 2 % (w/v) NaCl. Based on 16S rRNA gene phylogeny, strain TOUT106T was placed close to the Salmonella clade, with close similarity to Salmonella enterica subsp. arizonae strain NCTC 8297T (98.42 %). Results of genome-based phylogenetic analysis revealed that strain TOUT106T is placed well in the Klebsiella–Raoultella clade, by forming a distinct branch with Klebsiella michiganensis DSM25444T, Klebsiella oxytoca NCTC132727T, Klebsiella grimontii 06D021T and Klebsiella pasteurii SB6412T. The genomic DNA G+C content of strain TOUT106T is 53.53 mol%. The average nucleotide identity values of TOUT106T were less than 86.5 % with closely related members of the family Enterobacteriaceae . The major fatty acids of strain TOUT106T were C16 : 0, C17:0 cyclo, C14:0 3OH/C16:1 iso, C14 : 0, C19:0 cyclo ω8c, C18:1 ω6c/C18:1 ω7c, C12 : 0 and C16:1 ω7c/C16:1 ω6c. Strain TOUT106T showed differences in physiological, phenotypic and protein profiles by MALDI-TOF MS compared to its closest relatives. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain TOUT106T could be distinguished from the recognized species of the genus Klebsiella . It is suggested to represent a novel species of this genus, for which the name Klebsiella indica sp. nov. is proposed. The type strain is TOUT106T (=MCC 2901T=KACC 21384T=JCM 33718T).


2021 ◽  
Vol 7 (7) ◽  
Author(s):  
Agustina Undabarrena ◽  
Ricardo Valencia ◽  
Andrés Cumsille ◽  
Leonardo Zamora-Leiva ◽  
Eduardo Castro-Nallar ◽  
...  

Natural products (NPs) are synthesized by biosynthetic gene clusters (BGCs), whose genes are involved in producing one or a family of chemically related metabolites. Advances in comparative genomics have been favourable for exploiting huge amounts of data and discovering previously unknown BGCs. Nonetheless, studying distribution patterns of novel BGCs and elucidating the biosynthesis of orphan metabolites remains a challenge. To fill this knowledge gap, our study developed a pipeline for high-quality comparative genomics for the actinomycete genus Rhodococcus , which is metabolically versatile, yet understudied in terms of NPs, leading to a total of 110 genomes, 1891 BGCs and 717 non-ribosomal peptide synthetases (NRPSs). Phylogenomic inferences showed four major clades retrieved from strains of several ecological habitats. BiG-SCAPE sequence similarity BGC networking revealed 44 unidentified gene cluster families (GCFs) for NRPS, which presented a phylogenomic-dependent evolution pattern, supporting the hypothesis of vertical gene transfer. As a proof of concept, we analysed in-depth one of our marine strains, Rhodococcus sp. H-CA8f, which revealed a unique BGC distribution within its phylogenomic clade, involved in producing a chloramphenicol-related compound. While this BGC is part of the most abundant and widely distributed NRPS GCF, corason analysis unveiled major differences regarding its genetic context, co-occurrence patterns and modularity. This BGC is composed of three sections, two well-conserved right/left arms flanking a very variable middle section, composed of nrps genes. The presence of two non-canonical domains in H-CA8f’s BGC may contribute to adding chemical diversity to this family of NPs. Liquid chromatography-high resolution MS and dereplication efforts retrieved a set of related orphan metabolites, the corynecins, which to our knowledge are reported here for the first time in Rhodococcus . Overall, our data provide insights to connect BGC uniqueness with orphan metabolites, by revealing key comparative genomic features supported by models of BGC distribution along phylogeny.


Gene ◽  
2001 ◽  
Vol 278 (1-2) ◽  
pp. 107-114 ◽  
Author(s):  
Antonella Morea ◽  
Kalai Mathee ◽  
Michael J. Franklin ◽  
Alessio Giacomini ◽  
Michael O'Regan ◽  
...  

2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 516-521 ◽  
Author(s):  
Gaiyun Zhang ◽  
Yubian Zhang ◽  
Xijie Yin ◽  
Shuang Wang

A Gram-staining-positive, aerobic, motile and non-spore-forming actinobacteria, designated strain F10T, was isolated from a deep-sea sediment of the western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Nesterenkonia . Strain F10T shared highest 16S rRNA gene sequence similarity of 96.8 % with Nesterenkonia aethiopica DSM 17733T, followed by Nesterenkonia xinjiangensis YIM 70097T (96.7 %) and Nesterenkonia alba CAAS 252T (96.6 %). The organism grew at 4–50 °C, at pH 7.0–12.0 and in the presence of 0–12 % (w/v) NaCl, with optimal growth occurring at 40 °C, at pH 9.0 and in the presence of 1 % (w/v) NaCl. The peptidoglycan type was A4(alpha), l-Lys–Gly–l-Glu. The polar lipid profile of strain F10T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and two unknown lipids. The isolate contained MK-9 (92 %) and MK-8 (5.8 %) as the major components of the menaquinone system, and anteiso-C17 : 0 (50.9 %) and anteiso-C15 : 0 (29.8 %) as the predominant fatty acids. The G+C content of the genomic DNA of strain F10T was 66.2 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain F10T represents a novel species of the genus Nesterenkonia for which the name Nesterenkonia alkaliphila sp. nov. is proposed. The type strain is F10T ( = LMG 28112T = CGMCC 1.12781T = JCM 19766T = MCCC 1A09946T).


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