RT Journal Article SR Electronic(1) A1 Viezens, Juliane A1 Arvand, MardjanYR 2008 T1 Simultaneous presence of two different copies of the 16S rRNA gene in Bartonella henselae JF Microbiology, VO 154 IS 9 SP 2881 OP 2886 DO https://doi.org/10.1099/mic.0.2008/018630-0 PB Microbiology Society, SN 1465-2080, AB Bartonella henselae is an emerging pathogen of increasing medical significance. Previous investigations have revealed two different 16S rRNA gene variants among B. henselae isolates, resulting in delineation of the B. henselae population into 16S RNA type I and type II isolates. While studying 191 B. henselae isolates by multi-locus sequence typing (MLST) we detected three isolates that could not be assigned to a distinct 16S RNA type upon direct sequencing because of ambiguous nucleotides in a distinct region of the 16S rRNA gene. Cloning and sequencing of the target region of the 16S rRNA gene suggested that these atypical isolates contained different 16S rRNA gene copies. Southern blot and hybridization experiments confirmed the presence of two different 16S RNA gene copies in each isolate. The isolates were further analysed by 16S RNA type-specific PCR, which assigned them to both 16S RNA types I and II. These results suggest that a small percentage of B. henselae isolates may harbour two different 16S rRNA gene copies. These isolates, which accounted for 1.6 % of the isolates in our study, have probably emerged by horizontal gene transfer. The implications of these findings for identification and genotyping studies on B. henselae are discussed., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2008/018630-0