PCR differentiation of seventeen genospecies of Acinetobacter

Abstract

In the present study, strains of 17 reference Acinetobacter genospecies were investigated by using the polymerase chain reaction (PCR). We used primers to amplify spacer regions between the 16S and 23S genes in the prokaryotic rRNA genetic loci. When the spacer amplification products were resolved by electrophoresis, the resulting patterns could be used to distinguish all of the tested acinetobacters into 15 groups. The genospecies 5 (Acinetobacter junii), 7 (Acinetobacter johnsonii) and 10 produced the same characteristic PCR patterns, suggesting the identity of these three genospecies. A preliminary evaluation of the proposed scheme for PCR diagnostics was carried out. Using the proposed scheme, tested clinical strains were identified correctly to the genospecies level, and the identifications confirmed by conventional biochemical tests. On the basis of our results, PCR amplification of the 16S-23S spacer region shows significant promise as a tool for the simple identification of genospecies belonging to Acinetobacter sp. The nucleotide sequences of our primers are sufficiently highly conserved among these organisms as to permit PCR reactions to be carried out with a single set of reaction conditions and amplification parameters irrespective of species or genus.

Dissemination of a Clone of Unusual Phenotype of Pandrug-Resistant Acinetobacter baumannii at a University Hospital in Taiwan

“…Because of problems with the identification of Acinetobacter species in routine clinical microbiology laboratories, a phenotypic scheme for the identification of genomospecies 1 to 12 has been described previously (3); however, by using this system, discrepancies with the identities obtained by DNA-DNA hybridization, 16S rRNA sequencing, and 16S-23S ITS PCR-RFLP analysis and sequencing have been found (6,10,16,23). In the present study, the biochemical profiles of these asaccharolytic isolates (glucose-, lactose-, xylose-, and mannitol-nonoxidizing strains) of Acinetobacter species generated by three commercial biochemical identification kits did not allow categorization of the isolates as any particular genomospecies of Acinetobacter (3,7,25).…”

Discrimination of Acinetobacter Genomic Species by AFLP Fingerprinting

“…However, most of these studies either included only strains of the first 12 genomic species originally described in 1986 by Bouvet and Grimont (56,75) or contained only the type and/or reference strain of each genomic species (51)(52)(53)73). In addition, some of the techniques used in these studies failed to delineate all investigated genomic species, and strains belonging to the same species could not always be differentiated from each other.…”

“…Over the past few years, various molecular techniques have been employed for the phylogenetic analysis of the genus Acinetobacter, including PCR fingerprinting (73), amplified ribosomal DNA restriction analysis (ARDRA) (17,67), analysis of amplified 16s to 23s ribosomal DNA intergenic spacer regions (22,51), restriction analysis of amplified recA gene sequences (53), a multiplex PCR assay that simultaneously targets RecAand 16s rRNA-encoding genes (52), tRNA fingerprinting (24), and DNA sequence analysis of genes encoding 16s rRNA (38,56) or gyrase subunit B (75). However, most of these studies either included only strains of the first 12 genomic species originally described in 1986 by Bouvet and Grimont (56,75) or contained only the type and/or reference strain of each genomic species (51)(52)(53)73).…”

Comparison of ARDRA and recA-RFLP analysis for genomic species identification of Acinetobacter spp.

“…and was validated using 128 strains [4]. Analysis of PCR products of the 16S-23S spacer regions [13] and sequence variations in gyrB genes [14] have also been proposed as methods that can discern the genotype of strains but have yet to be validated with large numbers of strains. Both the ARDRA and recA methods require restriction digestion of PCR amplimers and thus take similar amounts of time to perform.…”