Acinetobacter silvestris sp. nov. discovered in forest ecosystems in Czechia

Abstract

We investigated a taxonomically novel group of the genus Acinetobacter , which included five strains isolated from soil and water samples collected in preserved forest areas in Czechia between 2013 and 2021. The whole-genome sequences of the strains were 3.1–3.2 Mb in size, with G+C contents of 38.0–38.2 mol%. Core genome-based phylogenetic analysis showed that they formed a compact and deeply branched clade within the genus. The genomic average nucleotide identity based on blast/digital DNA–DNA hybridization values for the novel strains were 99.2–99.6 %/95.2–98.4 %, whereas those between the novel strains and the type strains of the known Acinetobacter species reached <78 %/<24 %. The results of the genus-wide analysis of whole-cell MALDI-TOF mass spectra supported the sharp distinctness of the group. The five strains were non-glucose acidifying, nonhaemolytic, nonproteolytic and growing at 28 °C, but not at 32 °C; they assimilated acetate, benzoate, ethanol, l-histidine, 4-hydroxybenzoate, dl-lactate and malonate but not 4-aminobutyrate, l-aspartate or 2,3-butanediol; this phenotype is unique among the known Acinetobacter species. We conclude that the five strains represent a novel environmental species, for which the name Acinetobacter silvestris sp. nov. is proposed, with the type strain ANC 4999T (=CCM 9207T=CCUG 75877T=CNCTC 8124T).

On the ecology ofAcinetobacter baumannii– jet stream rider and opportunist by nature

“…Possibly, the situation in Europe differs from that in China or the general trend for the genus Acinetobacter does not represent the situation for A. baumannii. In line with the latter explanation, several Acinetobacter species such as A. silvestris(83) and A. bohemicus(60) have been isolated from forests. Although the microbial communities of forest soils are largely defined by pH(52) and dominant tree species (6), we could not observe a correlation of either of the two parameters with the lack of A. baumannii in forests (data not shown).…”

“…The Gram-negative Acinetobacter baumannii is notorious for its potential to act as an opportunistic pathogen in hospitals, facilitated by an exceptional resistance to desiccation stress and intrinsic as well as acquired resistance to antibiotics and disinfectants. The genus Acinetobacter currently comprises of around 100 described or tentative species (80, 83), the majority of which consist of environmental species, or commensals of human and animals that rarely cause any disease. Some species like A. lwoffii and A. johnsonii , which are regularly found on human skin, mucosa and within the gut of humans and animals, appear to play an essential role in the development of immune tolerance (29, 37, 98, 99).…”

Endophytic Bacteria Can Replace the Need for Synthetic Auxin during In Vitro Rooting of Pyrus communis

“…The same was observed in a study conducted by Quambusch et al [25] with six P. avium genotypes, where only five morphologically distinct isolates were identified from plants derived from tissue culture. The genus Acinetobacter is ubiquitous in nature and can be isolated from soil and/or water, and its high concentration, to the detriment of other genera, may be linked to its resistance to antibiotics and heavy metals [55][56][57].…”

Acinetobacter amyesii sp. nov., widespread in the soil and water environment and animals

“…In contrast, other species are widely dispersed in soil and water ecosystems [5][6][7], with some of them also colonizing animals and humans [8,9]. The present study is the continuation of the systematic effort of the Laboratory of Bacterial Genetics in Prague and collaborating laboratories to clarify the taxonomy of the genus Acinetobacter, which, since 2000, has resulted in the valid publication of 29 species names [2,10]. The aim of the current study was to define the taxonomic status of a novel provisional species, Taxon 36, which included six strains, collected in geographically distant areas.…”