Multispacer Typing To Study the Genotypic Distribution ofBartonella henselaePopulations

Abstract

Bartonella henselae, a worldwide fastidious bacterium, has a feline reservoir and is pathogenic for humans. However, the relationship between human and cat isolates of B. henselae, as well as its population dynamics and geographic heterogeneity, is not fully understood, in part because of the absence of appropriate typing methods. Multilocus sequence typing (MLST), the most discriminatory genotyping method for B. henselae, identified seven genotypes and suggested that human isolates arose from a limited number of cat isolates. Herein, we estimated the discriminatory power of multispacer typing (MST) by studying 126 B. henselae cat isolates from various areas of Europe, Asia, and the United States. We identified the nine most variable intergenic spacers conserved by both B. henselae and Bartonella quintana genomes. By comparing the sequences obtained from these nine spacers for each studied isolate, we identified 39 MST genotypes. The distribution of isolates into MST genotypes matched their phylogenetic organization into four clusters. MST showed that European and Asian isolates were different, in contrast with American isolates, but failed to identify pandemic strains. Our study demonstrated that MST is a powerful method for genotyping B. henselae at the strain level and may serve in studying the population dynamics of this bacterium and understanding the relationships between cat and human isolates. Finally, we provide a free-access MST-Rick online software program (http: //ifr48.timone.univ-mrs.fr/MST_BHenselae/mst) that investigators may use to compare their own MST sequences to our database.

Development of discriminatory multiple-locus variable number tandem repeat analysis for Bartonella henselae

“…The performance of MLST has been convincingly demonstrated to be comparable with that of PFGE by Iredell et al (2003), using the same isolates for testing both techniques. In their study, Li et al (2006) conclude that MST is more discriminatory than MLST. Some findings of our study suggest that MLVA is even more discriminatory than MST, at least when considering Using an isolate from the Philippines -which had MLVA patterns very different from the European isolates -as an outgroup, two main groups were detected in the NJ tree.…”

“…One such study has been initiated by Chang et al (2002), using the PFGE technique; however, a more userfriendly technique could help to investigate this link more easily. Comparison of isolates from different countries would help to establish their biodiversity and to determine whether some geographic markers can be identified, as suggested by the recent results of Li et al (2006). Also, we would look for the presence of dominant isolates or clusters with potential epidemic significance, which has not been described to date (Li et al, 2006).…”

“…The multilocus sequence technique (MLST) (Iredell et al, 2003) has a discriminatory power equivalent to that of PFGE. The multispacer typing technique (MST) (Li et al, 2006) appears to be a highly efficient method for genotyping B. henselae (39 profiles for 126 isolates). As these two techniques are based on sequencing, they are easily transferable; nevertheless, the necessity to sequence up to nine DNA regions (sometimes in both senses) for each isolate to be tested makes them costly, and not easily accessible for routine typing, for many potential users.…”

“…Comparison of isolates from different countries would help to establish their biodiversity and to determine whether some geographic markers can be identified, as suggested by the recent results of Li et al (2006). Also, we would look for the presence of dominant isolates or clusters with potential epidemic significance, which has not been described to date (Li et al, 2006). Furthermore, the role of fleas as selective carriers of B. henselae isolates remains unknown.…”

Canine bartonellosis: serological and molecular prevalence in Brazil and evidence of co-infection withBartonella henselaeandBartonella vinsoniisubsp.berkhoffii

“…Potentially, the discrepancy among sequenced genes from Dog #1 can be explained by the absence of CAL-1 and Fizz rpoB sequences in the GenBank database and by the high homology of rpoB gene among Bartonella species. Sequences of longer length and targeting additional genes would be necessary for a more complete phylogenetic classification of this B. henselae isolate [31].…”