ABSTRACT
The name 'Acinetobacter venetianus' has been used previously to designate three marine hydrocarbon-degrading Acinetobacter strains, of which strain RAG-1 (=ATCC 31012) has industrial applications for the production of the bioemulsifier emulsan. However, to date, the name of this taxon has not been validly published. In this study, five strains were examined to corroborate the delineation of this taxon by means of phenotypic characterization, DNA-DNA hybridization, selective restriction fragment amplification (AFLP), amplified rDNA restriction analysis (ARDRA), rpoB gene sequence analysis and tRNA intergenic spacer length polymorphism analysis (tDNA-PCR) and to emend the description of 'Acinetobacter venetianus' (ex Di Cello et al. 1997). AFLP analysis showed that the five strains formed a tight cluster at 56.8+/-5.0 % genomic relatedness that was separated from strains of other haemolytic species of the genus Acinetobacter and from the type and reference strains of other Acinetobacter species at Subject(s)
Acinetobacter/classification
, Industrial Microbiology
, Seawater/microbiology
, Acinetobacter/genetics
, Acinetobacter/isolation & purification
, Acinetobacter/physiology
, Amplified Fragment Length Polymorphism Analysis
, Animals
, Bacterial Typing Techniques
, Base Composition
, DNA, Bacterial/analysis
, DNA, Ribosomal
, DNA, Ribosomal Spacer/analysis
, DNA-Directed RNA Polymerases/genetics
, Fuel Oils
, Hemolysis
, Molecular Sequence Data
, Nucleic Acid Hybridization
, Phenotype
, Phylogeny
, Polymerase Chain Reaction
, RNA, Transfer/genetics
, Restriction Mapping
, Sequence Analysis, DNA
, Species Specificity
ABSTRACT
Since 1986, 68% of the Listeria monocytogenes isolates from human cases of invasive listeriosis in Sweden are available for retrospective studies. The aim of the present study was to characterize 601 human invasive isolates of L. monocytogenes in Sweden from 1986 to 2007 by using serotyping and pulsed-field gel electrophoresis. Since 1996, serovar 4b was permanently reduced to the second or third most common serovar in human cases in Sweden. During the latter period, 2000-2007, only 13% belonged to serovar 4b and 71% to 1/2a. The dendrogram, based on pulsovars, reveals two clusters with different serovars. Cluster 1 exhibits serovars 4b and 1/2b, whereas cluster 2 consists of serovar 1/2a. Serovar 1/2a seems to be more heterogeneous than serovar 4b.
Subject(s)
Listeria monocytogenes/classification , Listeria monocytogenes/pathogenicity , Listeriosis/microbiology , Phylogeny , Cluster Analysis , Electrophoresis, Gel, Pulsed-Field , Food Contamination/analysis , Food Microbiology , Humans , Retrospective Studies , Serotyping , SwedenABSTRACT
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.
