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

Abstract

Bartonella henselae is a zoonotic bacterium that infects cats and humans. Several attempts have been made to develop typing techniques for epidemiological purposes; however, most of the techniques developed do not appear to be sufficiently discriminatory or easy to use. In order to develop multilocus variable number tandem repeat (VNTR) analysis (MLVA) for B. henselae, 30 VNTR candidates were selected from the genome sequence of the reference strain Houston 1 (H1).The VNTR candidates were initially tested by PCR on six B. henselae isolates from different geographical areas. Five VNTRs were selected from those that showed two or more alleles. These five B. henselae VNTRs (BHVs) were tested on 42 feline B. henselae isolates and strains from France (23 isolates), Denmark (17 isolates), the Philippines (one isolate) and the USA (F1 strain), on one human isolate from Germany, and on the H1 reference strain. These BHVs were sufficiently discriminatory to obtain 31 different profiles (corresponding to two different groups) among the 44 isolates and strains of B. henselae tested. Thirty-five profiles were obtained using these BHVs and two variant alleles. The combination of the five markers led to a diversity index of 0.98. The stability of the five BHVs was demonstrated on the feline F1 strain, with no change in stability observed after 2, 21 and 41 passages. This is believed to be the first study conducted on B. henselae typing using MLVA, and it demonstrates the high quality of this technique for discriminating between B. henselae isolates.

Molecular typing of Mycobacterium intracellulare using multilocus variable-number of tandem-repeat analysis: identification of loci and analysis of clinical isolates

“…Final selection of VNTR loci was based on the following criteria of Monteil et al (2007): (i) candidate loci with less than two different alleles were excluded, (ii) when two VNTR loci candidates were isomorphic, one was excluded, and (iii) the full band patterns had to be readable.…”

Microevolution of Pandemic Vibrio parahaemolyticus Assessed by the Number of Repeat Units in Short Sequence Tandem Repeat Regions

“…Although recombination that produces large differences also occurs, it is less frequent [14]. This system has been highly successful for epidemiological studies of genetically homogeneous bacterial pathogens, such as Yersinia pestis [15], V. cholerae O1 and O139 [16], Escherichia coli O157:H7 [17], Bartonella henselae [18], and Mycobacterium leprae [19], providing useful genetic discrimination whether the populations were worldwide, regional, or from a local outbreak. MLVA of VNTRs has also been employed to study within-host evolution of Burkholderia pseudomallei infection [20].…”

Molecular Epidemiology of Feline and HumanBartonella henselaeIsolates

“…Genotype I was more frequently observed in humans in some countries where most cats are infected with genotype II ( 2 , 3 ). Genotype II is more prevalent in cats in Europe, Australia, and the United States ( 2 – 6 ), and most feline isolates from Asia belong to genotype I ( 7 – 9 ). In a recent study, 3 (1.6%) of 191 B. henselae isolates harbored 2 different 16S rDNA copies and could not be assigned to a distinct genotype ( 10 ).…”

“…Multiple-locus variable number tandem repeat analysis (MLVA) was recently developed for B. henselae typing ( 6 ). The results are produced in an intrinsically quantitative form, called a profile, corresponding to the number of basic units in an isolate for each variable number tandem repeat (VNTR).…”