Longitudinal monitoring of the dynamics of infections due to Bartonella species in UK woodland rodents

Abstract

Blood samples were repeatedly collected from 12 sympatric woodland rodents over a 12-month period and DNA extracts from each were incorporated into a bartonella-specific PCR targeting a fragment of the 16S/23S rRNA intergenic spacer region (ISR). The composition of each amplicon was analysed using restriction enzyme analysis (REA) and base sequence comparison. Bartonella DNA was detected in 70 of 109 samples. Eleven samples contained DNA derived from more than one strain. Sequence analysis of 62 samples found 12 sequence variants (ISR genotypes) that were provisionally assigned to 5 different species, 2 of which were newly recognized. Up to five different species were detected in each animal. On about two-thirds of occasions, a species detected I month was not there the next, but never was a genotype superseded by another of the same species. However, a genotype could be re-encountered months later in the same animal, even if interim samples contained other genotypes. Our results suggest that although most animals are bacteraemic most of the time, specific infections are often superseded and that a complex and dynamic epidemiology of bartonella bacteraemias exists in woodland rodents.

The effect of ecological and temporal factors on the composition of Bartonella infection in rodents and their fleas

“…In addition, we showed that the assemblage of those lineages greatly vary among individual carriers. In contrast to the majority of previous studies, in which bartonellae co-infection represented only a low percentage of the positive samples (Birtles et al, 2001;Kosoy et al, 2004;Telfer et al, 2007), our results indicate that co-infections are more common than singlegenotype infections in wild rodents and their fleas. It is likely that previous reports underestimated the occurrence of co-infection due to the challenge that low abundant genotypes represent when most of the Figure 4 Average of the relative abundance of bartonellae genotype diversity in the samples according to their origin (blood, flea sex, collection period).…”

“…Rodents are considered to be important reservoirs of bartonellae, as they host a great variety of Bartonella species and strains (Birtles et al, 2001;Kosoy et al, 2012). To date, 417 Bartonella species have been isolated from wild rodents (Gundi et al, 2004(Gundi et al, , 2009Kosoy, 2010;Sato et al, 2012).…”

ESTABLISHMENT OF A HEALTH SURVEILLANCE PROGRAM FOR REINTRODUCTION OF THE EURASIAN BEAVER (CASTOR FIBER) INTO SCOTLAND

“…Mycobacterium microti (Cavanagh et al, 2002), cowpox virus (Carslake et al, 2005), Cryptosporidium parvum (Quy et al, 1999), Eimeria spp. (Lewis and Ball, 1983), Bartonella (Birtles et al, 2001), Toxoplasma (Hay et al, 1983), and Leptospira (Salt and Little, 1977) have all been reported in UK wild rodent populations, and thus released beavers may become exposed. Ideally, wild rodents in the vicinity of the release sites should also be trapped and screened.…”

BartonellaInfection in Rodents and Their Flea Ectoparasites: An Overview

“…To describe the temporal dynamics of Bartonella infection in rodent communities, longitudinal field studies have been carried out (Fichet-Calvet et al 2000, Birtles et al 2001, Kosoy et al 2004a, Telfer et al 2007a, Bai et al 2008b, Welc-Faleciak et al 2010, Bai et al 2011. These studies have shown interesting variations in the pattern of Bartonella infections among seasons, rodent age cohorts, rodent sexes, in dependence of the level of flea parasitism, persistence of infection, and other factors in different rodent species and communities.…”

“…Through sequential screenings of tagged individual rodents, the Bartonella infection has shown to be very dynamic. Some rodents demonstrated a clearance of the infection in a short time (Birtles et al 2001), whereas others remained infected for periods as long as 9 months (Kosoy et al 2004a). In addition, reappearance of bacteremia after an apparent infection clearance has also been observed in wild rodents (Kosoy et al 2004b, Jardine et al 2006a, Bai et al 2011.…”