Naturally transformable Acinetobacter sp. strain ADP1 belongs to the newly described species Acinetobacter baylyi

Abstract

Genotypic and phenotypic analyses were carried out to clarify the taxonomic position of the naturally transformable Acinetobacter sp. strain ADP1. Transfer tDNA-PCR fingerprinting, 16S rRNA gene sequence analysis, and selective restriction fragment amplification (amplified fragment length polymorphism analysis) indicate that strain ADP1 and a second transformable strain, designated 93A2, are members of the newly described species Acinetobacter baylyi. Transformation assays demonstrate that the A. baylyi type strain B2(T) and two other originally identified members of the species (C5 and A7) also have the ability to undergo natural transformation at high frequencies, confirming that these five strains belong to a separate species of the genus Acinetobacter, characterized by the high transformability of its strains that have been cultured thus far.

FIG. 1.

Dendrogram based on a similarity matrix between tDNA-PCR fingerprints constructed by the differential base pairs algorithm (1). Strain designations from the American Type Culture Collection (ATCC), Czech Collection of Microorganisms (CCM), and the BCCM/LMG Bacteria Collection Laboratorium Microbiologie (LMG) are indicated where available. Underlining indicates designations used in the original publication of the strain.

FIG. 2.

Rooted 16S rRNA gene sequence-based dendrogram, revealing the different relationships between all published Acinetobacter genomic sequences as available from GenBank. The cluster analysis was performed using Genebase (Applied Maths) and was based on the neighbor-joining method using Psychrobacter immobilis as an outgroup. An open gap penalty of 100% and a unit gap cost of 25% were used. The 16S rRNA gene sequence used corresponds to nucleotides 99 through 1434 of the Escherichia coli gene (accession no. X80725). Bootstrap analysis (100×) values are shown at the branching points. Strain designations from the American Type Culture Collection (ATCC), Czech Collection of Microorganisms (CCM), and the BCCM/LMG Bacteria Collection Laboratorium Microbiologie (LMG) are indicated where available. Underlining indicates designations used in the original publication of the strain.

FIG. 3.

Dendrogram based on AFLP data of A. baylyi strains and one representative reference strain of each named and unnamed Acinetobacter species which are part of the Leiden University Medical Center AFLP fingerprint database, containing approximately 200 strains previously identified by DNA-DNA hybridization. Pearson product moment correlation was used as a similarity measure, and the unweighted pair group average linkage method (UPGMA) was used for clustering. Optimization was set at 0.01%, and zones of profiles used were within 4% and 97% of the total profile. The arrow (50%) denotes the species delineation level. Strain designations from the American Type Culture Collection (ATCC), Czech Collection of Microorganisms (CCM), and the BCCM/LMG Bacteria Collection Laboratorium Microbiologie (LMG) are indicated where available. Underlining indicates designations used in the original publication of the strain.