This study aimed to define the taxonomic position and structure of a novel, taxonomically unique group of 26 Acinetobacter strains, provisionally designated Taxon 24 (T24). The strains were recovered from soil and freshwater ecosystems (n = 21) or animals (n = 5) in Czechia, Scotland, Germany, the Netherlands and Turkey between 1993 and 2015. They were non-glucose-acidifying, nonhemolytic, nonproteolytic, growing at 32 °C and on acetate and ethanol as single carbon sources, but not on 4-hydroxybenzoate and mostly not at 37 °C. Their whole-genome sequences were 3.0-3.7 Mb in size, with GC contents of 39.8-41.3%. Based on core genome phylogenetic analysis, the 26 strains formed a distinct clade within the genus Acinetobacter, with strongly supported subclades termed T24A (n = 11), T24B (n = 8), T24C (n = 2), T24D (n = 3) and T24E (n = 2). The internal genomic ANIb values for these subclades were >94.8%, while the ANIb values between them were <92.5%. The results of MALDI-TOF MS-based analyses agreed with this classification. The five subclades differed from each other in the results of one to six carbon source assimilation tests. Given the genomic and phenotypic distinctness, internal coherence, numbers of available strains and geographically diverse origin of T24A and T24B, we propose the names Acinetobacter terrae sp. nov. and Acinetobacter terrestris sp. nov. for these two taxa, respectively. The type strains are ANC 4282v (= CCM 8986T = CCUG 73811T = CNCTC 8082T) and ANC 4471T (= CCM 8985T = CCUG 73812T = CNCTC 8093T), respectively. We conclude that these two species together with the other T24 strains represent a widely dispersed Acinetobacter clade primarily associated with terrestrial ecosystems.
- MeSH
- Acinetobacter * klasifikace MeSH
- bakteriální geny MeSH
- DNA bakterií genetika MeSH
- ekosystém MeSH
- fylogeneze * MeSH
- hybridizace nukleových kyselin MeSH
- půdní mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- sladká voda mikrobiologie MeSH
- techniky typizace bakterií MeSH
- zastoupení bazí MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Německo MeSH
- Nizozemsko MeSH
- Skotsko MeSH
- Turecko MeSH
In 1986, Bouvet and Grimont delineated two related taxa of the genus Acinetobacter termed genospecies (GS) 8 and 9. They proposed the name Acinetobacter lwoffii for GS8, which included the supposed type strain (CIP 64.10). As the authenticity of CIP 64.10 was later questioned, this study aimed at reassessing the taxonomy of these genospecies. We investigated 52 strains of GS8 or GS9, including CIP 64.10 and the genuine type strain of A. lwoffii (NCTC 5866T). All strains were subjected to the genus-wide comparative analyses of MALDI-TOF whole-cell mass spectra, rpoB gene sequences and metabolic traits while whole-genome sequences were analysed for 16 strains. The strains were classified into two distinct groups corresponding to GS8 (n=15) and GS9 (n=37). CIP 64.10 fell within GS8 whereas NCTC 5866T belonged to GS9. Intraspecies ANIb values for the genomes of GS8 (n=6) and GS9 (n=10) were ≥96.1% and ≥95.4%, respectively, whereas the ANIb values between them were 86.8-88.6%. Based on core genome phylogeny, GS8 and GS9 formed a distinct clade within the genus, with two respective, strongly supported subclades. GS8 and GS9 were similar in physiological and catabolic properties but were separable by MALDI-TOF MS. We conclude that the name A. lwoffii pertains to GS9 and not to GS8 as originally assumed and that these groups represent two species. We propose the name Acinetobacter pseudolwoffii sp. nov. for GS8, with ANC 5044T (=CCM 8638T=CCUG 67963T=CIP 111642T) as the type strain, and provide the emended description of A. lwoffii.
We studied the taxonomic position of six phenetically related strains of the genus Acinetobacter, which were recovered from hospital sewage in China and showed different patterns of resistance to clinically important antibiotics. Whole-genome sequencing of these strains and genus-wide phylogeny reconstruction based on a set of 107 Acinetobacter core genes indicated that they formed a separate and internally cohesive clade within the genus. The average nucleotide identity based on BLAST and digital DNA-DNA hybridization values between the six new genomes were 97.25-98.67% and 79.2-89.3%, respectively, whereas those between them and the genomes of the known species were ≤78.57% and ≤28.5%, respectively. The distinctness of the strains at the species level was also supported by the results of the cluster analysis of the whole-cell protein fingerprints generated by MALDI-TOF MS. Moreover, the strains displayed a catabolically unique profile and could be differentiated from the phylogenetically closest species at least by their inability to grow on d,l-lactate. A total of 18 different genes were found in the six genome sequences which encode resistance to seven classes of antimicrobial agents, including clinically important carbapenems, oxyimino-cephalosporins, or aminoglycosides. These genes occurred in five different combinations, with three to 10 different genes per strain. We conclude that the six strains represent a novel Acinetobacter species, for which we propose the name Acinetobacter cumulans sp. nov. to reflect its ability to acquire and cumulate diverse resistance determinants. The type strain is WCHAc060092T (ANC 5797T=CCTCC AB 2018119T=GDMCC 1.1380T=KCTC 62576T).
- MeSH
- Acinetobacter chemie klasifikace účinky léků genetika MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální geny * MeSH
- DNA bakterií genetika MeSH
- fylogeneze MeSH
- genom bakteriální genetika MeSH
- hybridizace nukleových kyselin MeSH
- mnohočetná bakteriální léková rezistence genetika MeSH
- nemocnice * MeSH
- odpadní vody mikrobiologie MeSH
- peptidové mapování MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
A set of 204 taxonomically well-defined strains belonging to 17 Acinetobacter spp., including 11 recently described species (A. albensis, A. bohemicus, A. colistiniresistens, A. courvalinii. A. dispersus, A. gandensis, A. modestus, A. proteolyticus, A. seifertii, A. variabilis, and A. vivianii) and six species of the so-called haemolytic clade (A. beijerinckii, A. gyllenbergii, A. haemolyticus, A. junii, A. parvus, and A. venetianus), were subjected to MALDI-TOF mass spectrometric profiling. The identification outputs were evaluated using the current version (8.0.0.0) of the commercially available Bruker Daltonics, Biotyper database, which does not contain reference entries for six of the species tested. Up to 29% of the strains were falsely identified as different Acinetobacter spp. present in the Biotyper database, resulting mostly from the close phylogenetic relationship of species of the haemolytic clade. To obtain more reliable identification, extending the commercial database showed only partial improvement, while the use of an alternative MALDI matrix solution (strongly acidified ferulic acid) allowed correct identification of nearly all problematic strains.
- MeSH
- Acinetobacter klasifikace genetika izolace a purifikace MeSH
- bakteriální geny MeSH
- databáze genetické MeSH
- fylogeneze MeSH
- infekce bakteriemi rodu Acinetobacter diagnóza mikrobiologie MeSH
- limita detekce * MeSH
- RNA ribozomální 16S genetika MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice přístrojové vybavení metody MeSH
- techniky typizace bakterií přístrojové vybavení metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We recovered eight strains of the genus Acinetobacter from hospital sewage at West China Hospital in Chengdu, China. Based on the comparative analysis of the rpoB sequence, these strains formed a strongly supported and internally coherent cluster (intra-cluster identity of ≥98.0 %), which was clearly separated from all known Acinetobacter species (≤91.1 %). The eight strains also formed a tight and distinct cluster based on the genus-wide comparison of whole-cell mass fingerprints generated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In addition, the combination of their ability to assimilate 2,3-butanediol and phenylacetate, but not 4-hydroxybenzoate, and the inability to grow at 37 °C could distinguish these eight strains from all known Acinetobacter species. Whole-genomic sequencing has been performed for two selected strains, WCHA60T and WCHA62. There were 96.65 % average nucleotide identity (ANI) and 72 % in silico DNA-DNA hybridization (isDDH) values between WCHA60T and WCHA62, suggesting that the two strains indeed belonged to the same species. In contrast, the ANI and isDDH values between the two strains and the known Acinetobacter species were <83 and <30 %, respectively; both of which were far below the cut-off to define a bacterial species. Therefore, the eight strains should be considered to represent a novel species of the genus Acinetobacter, for which the name Acinetobacterwuhouensis sp. nov. is proposed. The type strain is WCHA60T (=CCTCC AB 2016204T=GDMCC 1.1100T=KCTC 52505T).
- MeSH
- Acinetobacter klasifikace genetika izolace a purifikace MeSH
- DNA bakterií genetika MeSH
- fylogeneze * MeSH
- hybridizace nukleových kyselin MeSH
- mastné kyseliny chemie MeSH
- nemocnice * MeSH
- odpadní vody mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- techniky typizace bakterií MeSH
- zastoupení bazí MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
Acinetobacter seifertii is a recently described species that belongs to the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. It has been recovered from clinical samples and is sometimes associated with antimicrobial resistance determinants. We present here the case of three A. seifertii clinical isolates which were initially identified as Acinetobacter sp. by phenotypic methods but no identification at the species level was achieved using semi-automated identification methods. The isolates were further analysed by whole genome sequencing and identified as A. seifertii. Due to the fact that A. seifertii has been isolated from serious infections such as respiratory tract and bloodstream infections, we emphasize the importance of correctly identifying isolates of the genus Acinetobacter at the species level to gain a deeper knowledge of their prevalence and clinical impact.
- MeSH
- Acinetobacter baumannii genetika MeSH
- Acinetobacter klasifikace účinky léků genetika izolace a purifikace MeSH
- antibakteriální látky farmakologie MeSH
- DNA bakterií genetika MeSH
- DNA gyráza genetika MeSH
- genom bakteriální MeSH
- infekce bakteriemi rodu Acinetobacter krev epidemiologie mikrobiologie MeSH
- katétrové infekce mikrobiologie MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- RNA ribozomální 16S genetika MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Bolívie epidemiologie MeSH
A draft whole-genome sequence was obtained for Acinetobacter guangdongensis strain KCTC 42012T and compared against those of the type strains of all Acinetobacter species with validly published names. High similarity was found to Acinetobacter indicus CCM 7832T (average nucleotide identity based on blast and digital DNA-DNA hybridization values of 96.3 and 70.4 %, respectively). In addition, the metabolic, physiological and chemotaxonomic features of KCTC 42012T were shown to be congruent with those of A. indicus. We conclude that Acinetobacter guangdongensisFeng et al. 2014 is a later heterotypic synonym of Acinetobacter indicus Malhotra et al. 2012.
Strains of the genusAcinetobacter, classified as genomic species 13BJ/14TU have been previously associated with human infections and resistance to colistin. To clarify the taxonomy of this provisional group, we investigated 24 strains that have been isolated from humans since the 1960s in 10 countries. The genus-wide analysis of the rpoB and gyrB sequences of all strains and whole-genome sequences of strains representing different rpoB/gyrB genotypes showed that the 24 strains formed a distinct monophyletic group within the so-called haemolytic clade of the genus Acinetobacter. The distinctness of the group at the species level was supported by the results of the cluster analysis of the whole-cell protein fingerprints generated by matrix-assisted laser desorption ionization-time-of-flight MS. The 24 strains had very similar metabolic features and could be distinguished from other members of the genus by the combination of strong haemolytic and proteolytic activities and the ability to oxidize d-glucose and grow on phenylacetate and/or l-phenylalanine. The minimum inhibitory concentrations of the 24 strains to colistin and polymyxin B ranged from 16 to 64 mgl-1 and from 4 to 32 mgl-1, respectively, so uniformly reaching the current clinical resistance breakpoint (4 mg l-1) for these drugs. Genus-wide comparison revealed that such a consistently high level of resistance to polymyxins is a unique feature among species of the genus Acinetobacter,which occur in humans. We conclude that genomic species 13BJ/14TU represents a biologically meaningful and medically relevant species, for which the name Acinetobacter colistiniresistens sp. nov. is proposed. The type strain is NIPH 2036T (=CCM 8641T=CIP 110478T=CCUG 67966T=CNCTC 7573T).
- MeSH
- Acinetobacter klasifikace genetika izolace a purifikace MeSH
- bakteriální geny MeSH
- bakteriální léková rezistence * MeSH
- DNA bakterií genetika MeSH
- fylogeneze * MeSH
- infekce bakteriemi rodu Acinetobacter mikrobiologie MeSH
- lidé MeSH
- polymyxiny farmakologie MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- zastoupení bazí MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Two novel species names, Acinetobacter bohemicus and Acinetobacter pakistanensis, appeared on validation list no. 161 (January 2015) under priority numbers 26 and 28, respectively. As the published data suggested a high similarity of the organisms associated with these names, we aimed to define their taxonomic relationship. The study set included all strains used in the original nomenclatural proposals, i.e. 25 strains of A. bohemicus and one strain of A. pakistanensis. The average nucleotide identity values (95.9 and 96.1 % based on blast and MUMmer, respectively) between the whole-genome sequences of A. bohemicus ANC 3994T and A. pakistanensis KCTC 42081T supported the identity of these type strains at the species level. Based on the genus-wide comparative analyses of the rpoB sequences and whole-cell fingerprints generated by matrix-assisted laser desorption/ionization-time-of-flight MS, A. pakistanensis KCTC 42081T fell within the respective clusters formed by the 25 A. bohemicus strains. The same picture was obtained on the basis of comparative analysis of 16S rRNA gene sequences of KCTC 42081T and three A. bohemicus strains. Finally, the metabolic and physiological features of KCTC 42081T were found to be congruent with those of A. bohemicus. Based on these results, we conclude that Acinetobacter pakistanensis is a later heterotypic synonym of Acinetobacter bohemicus.
A novel, taxonomically unique group of six strains of the genus Acinetobacter was discovered during an exploratory study on strains culturable from soil and water natural ecosystems in the Bohemian part of the Czech Republic. Based on the comparative analyses of the 16S rRNA gene, gyrB and rpoB sequences, these strains formed strongly supported and internally coherent clusters (intracluster identities of ≥99.9, ≥96.1 and ≥97.3 %, respectively), which were clearly separated from all known species of the genus Acinetobacter (≤98.7, ≤83.2 and ≤88.9 %, respectively). The distinctness of the group at the species level was evidenced also by the results of the genus-wide analyses of the whole-cell mass fingerprints of the six strains generated by matrix-assisted laser desorption/ionization-time-of-flight MS and the whole-genome sequence of a group member, ANC 4603T. Compared with the known species of the genus Acinetobacter, all six strains exhibited a unique phenotype, characterized by psychrotolerance (growth at 1 °C through 28 °C), the inability to grow at 32 °C and the ability to assimilate l-aspartate and malonate but not 2,3-butanediol or citrate. Based on these results, the name Acinetobacter celticus sp. nov. is proposed for the taxon represented by the six strains. The type strain is ANC 4603T (=CCM 8700T=CCUG 69239T=CNCTC 7549T).
- MeSH
- Acinetobacter klasifikace genetika izolace a purifikace MeSH
- bakteriální geny MeSH
- DNA bakterií genetika MeSH
- ekosystém MeSH
- fenotyp MeSH
- fylogeneze * MeSH
- hybridizace nukleových kyselin MeSH
- mikrobiologie vody * MeSH
- půdní mikrobiologie * MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- techniky typizace bakterií MeSH
- zastoupení bazí MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
