Abstract
Background
This research aimed to investigate the prevalence and diversity of Bartonella in small mammals and their ectoparasites from the Central Highlands of Madagascar and to refine existing information on potential associated zoonotic diseases.
Methods
A retrospective analysis was performed on mammals and their ectoparasites collected in the Fandriana and Ankazobe districts, including 253 spleen samples from seven small mammal species and 183 individual ectoparasites (132 fleas and 51 ticks). Genomic DNA was extracted and amplified by polymerase chain reaction (PCR) targeting the nuoG gene (346 bp). Sanger sequencing of the PCR products was performed to assess Bartonella diversity using phylogenetic analysis.
Results
In total, 60.1% (152/253) of small mammals and 15.9% (21/132) of fleas tested positive for Bartonella, with Rattus rattus (69.1%, 137/198) and the associated flea Synopsyllus fonquerniei (21.2%, 14/66) having the highest infection rates. At the same sampled locations, adult R. rattus were more frequently infected with Bartonella than juveniles. Phylogenetic analysis revealed five associated clades of Bartonella with two clades recognized as a potential zoonotic species (B. elizabethae and B. kosoyi).
Conclusions
Using molecular tools, we report a high prevalence of Bartonella in small mammals and their fleas in the Central Highlands of Madagascar. Two potential Bartonella zoonotic species were identified in R. rattus and their fleas. As these bacteria are generally vector-borne, they could have a significant impact on public health in the vicinity of our study areas and, in general, in Madagascar, and merit further investigation.
Graphical Abstract
Supplementary Information
The online version contains supplementary material available at 10.1186/s13071-025-07233-9.
Keywords: Bartonella, Fandriana and Ankazobe districts, Fleas, Small mammals, Zoonoses
Background
Small mammals are recognized as reservoirs of different zoonotic bacteria that cause infectious diseases in humans, such as leptospirosis (Leptospira spp.), plague (Yersinia pestis), murine typhus (Rickettsia typhi), Lyme disease (Borrelia spp.), and bartonellosis (Bartonella spp.) [1]. Members of the genus Bartonella (family Bartonellaceae; order Rhizobiales) are emerging vector-borne zoonotic bacteria of medical and veterinary importance that are distributed worldwide and represent a global public health concern [2, 3]. These microorganisms are fastidious, Gram-negative, facultative intracellular bacteria with a marked tropism for erythrocytes and endothelial cells [4, 5]. They infect a broad range of vertebrate hosts, with small mammals, particularly rodents, shrews, and bats, acting as the principal reservoirs [4, 6]. Infections have also been reported in other mammals, including carnivorans and humans [7]. Small mammals, especially rodents, harbor the greatest diversity of Bartonella species, facilitating transmission within the mammalian community or to humans upon exposure [2, 8]. Globally, approximately 90 rodent species are recognized as hosts for more than 22 species of Bartonella [4, 9]. Currently, the List of Prokaryotic names with Standing in Nomenclature (LPSN) records 42 species and subspecies of Bartonella [10], of which at least 15 are associated with human diseases [7]. Transmission to humans and other animals occurs through blood-sucking arthropod vectors (such as fleas, ticks, lice, and sandflies), direct contact with infectious feces of arthropod vectors, or scratches or bites of infected animals [2, 5].
Among the described species of Bartonella, B. rattimassiliensis, B. rochalimae, B. elizabethae, B. grahamii, B. tamiae, B. vinsonii subsp. arupensis, B. vinsonii subsp. berkhoffii, B. birtlessi, B. tribocorum, and B. washoensis are associated with rodents and may cause fever, endocarditis, lymphadenitis, neuroretinitis, myocarditis, and meningitis in humans [2, 4, 7, 8].
Madagascar is a biodiversity hotspot and accordingly also for zoonotic risks owing to important levels of human–wildlife contact, environmental change, and the presence of multiple potential reservoirs and vectors [11–17]. Despite the increasing worldwide recognition of Bartonella associated with emerging zoonotic agents, available data from Madagascar are notably limited. A few studies have reported the presence of Bartonella in fruit bats [18], rodents [19], and mammal ectoparasites [20]. However, the prevalence, diversity, and potential risk to public health associated with Bartonella in small mammals and their ectoparasites in Madagascar are still poorly understood.
Understanding the circulation of Bartonella in small mammals and their ectoparasites is crucial to assess their diversity, elucidate their role in zoonotic transmission, anticipate potential outbreaks, and provide insights into their impact on public health. Herein, we investigated the prevalence and diversity of Bartonella in small mammals and their ectoparasites to provide new insights into their potential implication for public health in Madagascar.
Methods
Study sites
The study was carried out in two areas of Madagascar’s Central Highlands: Ankazobe District, located in the northern part of the former Antananarivo Province (now Analamanga Region), and Fandriana District, located in the northern part of former Fianarantsoa Province (now Amoron’i Mania Region). Small mammals were captured at four localities, representing two different habitats: rural zones with no natural forest cover (Ambohitromby at 18° 26.07′ S, 47° 10.12′ E, 1260 m elevation; Kiangara at 17° 58.31′ S, 47° 1.78′ E, 904 m elevation; and Fandanana at 20° 19.9′ S, 47° 25.9′ E, 1417 m elevation), and an area of natural montane forest (Réserve Spéciale d’Ambohitantely at 18° 10.26′ S, 47° 16.90′ E, 1595 m elevation) (Fig. 1).
Fig. 1.
Map showing elevation gradients in (A) Ankazobe District and (B) Fandriana District in the Central Highlands of Madagascar
Small mammals and ectoparasite sampling
The study was conducted in strict accordance with the terms of a research permit issued by the Malagasy authority (Direction du Système des Aires Protégées, Direction Générale de l’Environnement et des Forêts) and associated field collecting permit (number 225/16/MEEF/SG/DGF/DSAP/SCB.Re, issued 19 September 2016).
Small mammals were captured during September and December 2016 using two types of traps: Sherman (H.B. Sherman Trap, Tallahassee, FL; 23 long × 7.5 width × 9 cm high) and National (Tomahawk Live Trap, Hazelhurst, WI; 39.2 long × 12.3 wide × 12.3 cm high). Each trap was baited with peanut butter, which was renewed daily. Small mammals were captured on three successive nights at each of the four sites. All captured animals were euthanized by cervical dislocation. Ectoparasites were removed by rigorously brushing the fur of each individual within a 30-cm-deep basin, and they were preserved in ethanol; the subsequent steps involved ectoparasite species identification and molecular screening. The ectoparasites species were identified morphologically using available taxonomic keys for fleas [21] and ticks [22].
Biological data collection
Identification of small mammal species was performed using body measurements and available taxonomic keys [23]. Blood samples were collected by cardiac puncture, dropped onto filter paper disks (LDA22, Zoopole, Ploufragan, France), and centrifuged to obtain sera. A spleen sample for each individual were aseptically collected and conserved in Cary Blair medium.
For black rats (Rattus rattus), their age was inferred on the basis of different characters. For males, body weight, testicular position (abdominal or scrotal), and epididymes development (undeveloped or developed) were noted to estimate age class and reproductive status. For females, in addition to weight, mammae state (small, large or lactating), vaginal condition (perforated or imperforate), embryos (present or absent), and placental scars (absent or present) were used to extrapolate age class and reproductive status. Three age categories were used for black rats (juvenile, subadult, and adult) [24, 25].
Molecular screening of Bartonella
The spleen sample was smashed with 1× phosphate-buffered saline (PBS). Genomic DNA was extracted according to the manufacturer’s protocol using QIAmp DNA mini kit (Qiagen, Germany). For ectoparasites, DNA extraction was performed using DNeasy Blood and Tissue kit (Qiagen, Germany) after mechanical grinding with the Tissue Lyser II (Qiagen, Germany). Subsequently, conventional PCR was carried out to amplify a 346-bp region of gamma subunit of nicotinamide adenine dinucleotide hydrogen (NADH) dehydrogenase (nuoG) of Bartonella, using a set of primers nuoG-F (5′-GCGTGATTGTTCTCGTTA-3′) and nuoG-R (5′-CACGACCACGGCTATCAAT-3′). Cycling conditions for the PCR included: 94 °C for 2 min, 45 cycles of 94 °C for 30 s, 55 °C for 1 min, 72 °C for 1 min, and a final extension of 72 °C for 7 min [26]. In addition to extraction control (no sample) during DNA extraction, positive and negative controls were also amplified to avoid the presence of false positive and false negative results. Amplicons obtained were run for electrophoresis on a 1.5% agarose gel under a 120-V generator for 90 min. PCR products were visualized using Gelscan (Vilber Lourmat, France) and subsequently sent to Genoscreen (Lille, France) for Sanger sequencing using the same primers as the initial PCR assay.
Phylogenetic analysis
Nucleotide sequences obtained from nuoG-positive individuals were manually edited using Geneious Prime sequence alignment editor version 2024.0.7 [27]. The program Basic Local Alignment Search Tool (BLAST, https://blast.ncbi.nlm.nih.gov) [28] was used to compare identified nucleotide sequences with those available on GenBank. Before performing the phylogenetic analysis, the best substitution model was determined with jModelTest 2.1.10 [29] using the lowest Akaike information criterion score. Phylogenetic trees were constructed using maximum likelihood method, and bootstrap analyses were performed with 10,000 iterations using MEGA X software [30].
Statistical analyses
Chi-squared tests were carried out to verify the difference in Bartonella infection according to host species and sex of small mammals. For Rattus rattus, we performed generalized linear models (GLM) using a binomial distribution to examine the infection risk of Bartonella according to the predictor variables (age class, sex, and locality). Selection of the best model was based on the Akaike information criterion (AIC). Odds ratios and p-values indicate correlations of Bartonella infection in R. rattus with the analyzed variables. Statistical analyses were performed using R software [31].
Results
Molecular detection of Bartonella in small mammals
A total of 253 spleen-derived DNA samples from small mammals were tested by conventional PCR targeting the nuoG gene of Bartonella. Of these animals, 152 individuals were infected, with an overall prevalence of 60.1% (152/253), with 54.1% (137/253) of these infected individuals being Rattus rattus. Overall infection rates varied between 48.3% and 80.9% at the four study sites, ranging from 48.3% (29/60) at Ambohitromby, 52.1% (37/71) at Kiangara, 59.3% (35/59) at Ambohitantely, to 80.9% (51/63) at Fandriana (Table 1). According to host species, 92.3% (12/13) of Eliurus minor, 69.1% (137/198) of R. rattus, 50.0% (1/2) of E. majori, 50.0% (1/2) of Nesogale dobsoni, and 20.0% (1/5) of Microgale cowani were infected by Bartonella (Table 1). Variation in Bartonella prevalence was significant associated with host species (chi-squared test, χ2 = 65.67, df = 6, P < 0.001, Table 1). In analyses of infected individuals at the four localities based on sex, 62.4% (78/125) of individual females and 57.8% (74/128) of individual males were not statistically significant (chi-squared test, χ2 = 0.554, df = 1, P = 0.456, Table 1).
Table 1.
Prevalence of Bartonella in small mammals collected in the Central Highland areas of Madagascar
| Parameter | Location | Total (%) | df | χ2 value | P | ||||
|---|---|---|---|---|---|---|---|---|---|
| Forest | Rural | ||||||||
| Ambohitantely | Ambohitromby | Kiangara | Fandriana | ||||||
| Family | Species | 6 | 65.67 | 0.00001 | |||||
| Muridae | Mus musculus | 0/7 | 0/4 | 0/14 | 0/7 | 0/32 | |||
| Rattus rattus | 20/29 (68.9) | 29/56 (51.7) | 37/57 (64.9) | 51/56 (91) | 137/198 (69.1) | ||||
| Nesomyidae | Eliurus majori | 1/2 (50.0) | – | – | – | 1/2 (50.0) | |||
| E. minor | 12/13 (92.3) | – | – | – | 12/13 (92.3) | ||||
| Tenrecidae | Microgale cowani | 1/5 (20.0) | – | – | – | 1/5 (20.0) | |||
| Nesogale dobsoni | 1/2 (50.0) | – | – | – | 1/2 (50.0) | ||||
| Setifer setosus | 0/1 | – | – | – | 0/1 | ||||
| Sex | 1 | 0.55 | 0.456 | ||||||
| Female | 17/26 (65.3) | 12/29 (41.3) | 22/36 (61.1) | 27/34 (79.4) | 78/125 (62.4) | ||||
| Male | 18/33 (54.5) | 17/31 (54.8) | 15/35 (42.8) | 24/29 (82.7) | 74/128 (57.8) | ||||
| Overall prevalence | 35/59 (59.3) | 29/60 (48.3) | 37/71 (52.1) | 51/63 (80.9) | 152/253 (60.1) | ||||
DNA-positive specimens of Bartonella / total specimens (prevalence %); “–” indicates that no animal of this species was captured
For R. rattus, 51.7% (29/56) were infected by Bartonella at Ambohitromby, 64.9% (37/57) at Kiangara, 68.9% (20/29) at Ambohitantely, and 91.0% (51/56) at Fandriana. Using GLM analysis, we found significant differences in R. rattus of Bartonella infection rates at the sampled localities (P = 0.016) (Fig. 2). According to R. rattus age classes, 36.1% (13/36) of juveniles, 78.4% (40/51) of subadults, and 75.6% (84/111) of adults were positive (P < 0.001) (Fig. 2). Further, on the basis of sex, 71.7% (71/99) of individual females and 66.6% (66/99) of individual males were infected by Bartonella (P = 0.56) (Fig. 2).
Fig. 2.
Factors associated with Bartonella infection in Rattus rattus by sex, age class, and different study sites in the Central Highlands of Madagascar. The odds ratio (OR) measure is the chance of Bartonella infection relative to a reference group
Molecular detection of Bartonella in ectoparasites of small mammals
For ectoparasites, 132 individual fleas comprising five species (three introduced Xenopsylla cheopis, Pulex irritans, and Echidnophaga gallinacea, and two endemic Synopsyllus fonquerniei and Dinopsyllus brachypecten) were tested by conventional PCR. Among the 132 DNA flea samples, 15.9% (21/132) tested positive with overall prevalence of 17.5% (7/40) at Fandriana, 17.4% (11/63) at Kiangara, 11.1% (1/9) at Ambohitantely, and 10.0% (2/20) at Ambohitromby. Fleas were collected from R. rattus at all four localities. According to flea species, infection rates of Bartonella were 21.2% (14/66) for S. fonquerniei, 15.7% (3/19) for X. cheopis, 11.7% (2/17) for D. brachypecten, 3.4% (1/29) for E. gallinacea, and 100% (1/1) for P. irritans. When found on small mammal species, S. fonquerniei were infected at all four localities (Table 2). For ticks, 51 individuals composed of seven species (Haemaphysalis sp., H. elongata, Ixodes sp. 1, Ixodes sp. 2, I. lunatus, I. nesomys, and I. colasbelcouri) were tested by conventional PCR. Bartonella was not detected in any of the tested tick samples (Table 2).
Table 2.
Prevalence of Bartonella in ectoparasite of small mammals collected in the Central Highlands of Madagascar (N: number of individuals, Prev: prevalence)
| Host | Ambohitantely | Ambohitromby | Kiangara | Fandriana | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rattus rattus | Eliurus minor | Setifer setosus | R. rattus | R. rattus | R. rattus | ||||||||
| N | Prev | N | Prev | N | Prev | N | Prev | N | Prev | N | Prev | ||
| Fleas | Synopsyllus fonquerniei | 7 | 1/7 (14.2) | 1 | 0/1 | 1 | 0/1 | 12 | 2/12 (16.6) | 23 | 7/23 (30.4) | 22 | 4/22 (18.1) |
| Xenopsylla cheopis | – | – | – | – | – | – | 4 | 0 | 15 | 3/15 (20.0) | – | – | |
| Echidnophaga gallinacea | – | – | – | – | – | – | 4 | 0 | 25 | 1/25(4.0) | – | – | |
| Pulex irritans | – | – | – | – | – | – | – | – | – | – | 1 | 1/1 | |
| Dinopsyllus brachypecten | – | – | – | – | – | – | – | – | – | – | 17 | 2/17(11.7) | |
| Ticks | Haemaphysalis sp. | – | – | – | – | – | – | – | – | – | – | 22 | 0/22 |
| H. elongata | – | – | – | – | 1 | 0/1 | – | – | – | – | – | – | |
| Ixodes sp. 1 | – | – | – | – | – | – | – | – | – | – | 12 | 0/12 | |
| Ixodes sp. 2 | – | – | – | – | – | – | – | – | – | – | 1 | 0/1 | |
| I. lunatus | – | – | – | – | – | – | – | – | – | – | 1 | 0/1 | |
| I. nesomys | – | – | – | – | – | – | – | – | – | – | 2 | 0/2 | |
| I. colasbelcouri | 12 | 0/12 | – | – | – | – | – | – | – | – | – | – | |
DNA-positive specimens of Bartonella / total specimens (prevalence %); “–” indicates that no ectoparasite of this species was collected
BLAST results and phylogenetic analysis of Bartonella species
A total of 22 Bartonella nuoG sequences were obtained and compared with those deposited in GenBank to assess sequence similarity. Among them, eight sequences, viz. two from Rattus rattus, five from Synopsyllus fonquerniei, and one from Dinopsyllus brachypecten showed 100% similarity with sequences of uncultured Bartonella sp. deposited in GenBank (JX131676). Two sequences, one from Echidnophaga gallinacea and one from S. fonquerniei, also showed 100% similarity with B. kosoyi (CP031843). Four sequences from Eliurus minor showed 95% similarity with Bartonella sp. (OR187492). Seven sequences, viz. five from R. rattus, one from S. fonquerniei, and one from Xenopsylla cheopis, highlighted 100% similarity with uncultured Bartonella sp. (MF498850). One sequence from Nesogale dobsoni showed 89% similarity with Bartonella sp. (MN529408).
On the basis of the phylogenetic analysis (maximum likelihood method and Tamura–Nei model), five clades of Bartonella were identified. The first falls within B. elizabethae (JH725139) identified in R. rattus, D. brachypecten, and S. fonquerniei from Ambohitromby, Fandriana, and Kiangara. The second clade, which is referable to B. kosoyi (CP031843), was identified in S. fonquerniei and E. gallinacea from Kiangara. The third clade included a Bartonella sequence from E. minor collected in Ambohitantely, which clustered near Bartonella sp. (OR187492). The fourth clade corresponded to B. phoceensis (CADEAD010000003) and included R. rattus and two species of fleas, S. fonquerniei from Ambohitantely and X. cheopis from Kiangara. The last clade, with a Bartonella sequence from N. dobsoni collected in Ambohitantely, grouped with Bartonella sp. (MN529408). New sequences obtained in this study were deposited in GenBank under accession numbers PX349281 to PX349303 (Fig. 3, Additional file 1).
Fig. 3.
Phylogenetic reconstruction of Bartonella species in small mammals and fleas collected in Ankazobe and Fandriana district using maximum likelihood method on the basis of the nuoG gene. The phylogenetic tree was performed using Tamura–Nei model (TrN + I + G) as the best substitution model according to jModelTest with 10,000 iterations. Scale bar indicates the number of substitutions per site. Sequences obtained in this study are highlighted in bold
Discussion
Small mammals contribute to ecosystem functioning on the basis of a number of natural history aspects, including seed dispersal, regulating arthropod populations, playing a role in the food chain (as invertebrate predators and carnivore animal prey), and in the maintenance and transmission of zoonotic agents within their community and to humans [32]. Madagascar is home to 64 species of nonvolant small mammals, grouped in three orders (Afroscoricida, Soricomorpha, and Rodentia), with an endemism rate of 92% [33]. Invasive and introduced rodents such as Rattus rattus are the most abundant species in rural and forest habitats, possibly being responsible for the decline of endemic rodent species through competition or disease transmission [34]. Moreover, R. rattus host numerous zoonotic agents such as Yersinia pestis, which have a notable impact on public health in Madagascar, particularly in the Central Highlands [35].
As reported herein, the presence of Bartonella spp. was confirmed on the basis of molecular tools in endemic rodents (Nesomyidae: Eliurus majori and E. minor), endemic tenrecs (Tenrecidae: Microgale cowani and Nesogale dobsoni), introduced rodents (Muridae: R. rattus), and their associated fleas (Pulicidae: Synopsyllus fonquerniei, Echidnophaga gallinacea, Pulex irritans, and Xenopsylla cheopis, and Ctenophthalmidae: Dinopsyllus brachypecten). According to age class, our data indicate notable variation of Bartonella infection rates in R. rattus, with subadults and adults having rates than juveniles. Krügel et al. [36] also found this same relationship in Bartonella infection rates of R. rattus, but with a two-category age classification, with juveniles being significantly less infected than adults. The life cycle of Bartonella species, such as B. tribocorum, can explain why older animals are more likely to be infected by Bartonella, as this bacterium can be maintained in the host without apparent deleterious consequences [37, 38]. Regarding differences between sampling localities, our study showed a higher prevalence of Bartonella at Fandriana, which may be explained by the greater diversity and abundance of ectoparasites observed in captured R. rattus at this locality (Table 2).
The density of vectors is a major factor influencing Bartonella prevalence and transmission within small mammal communities or in humans [4]. Furthermore, all flea species tested in this study were infected by Bartonella, but with different prevalence rates. The endemic flea, S. fonquerniei, is the most frequently infected by Bartonella at the four study localities. A previous study undertaken at Ambohitantely also showed higher Bartonella infection rates in S. fonquerniei, as compared with other rodent flea species [19], but the vectorial competence of this endemic flea in the transmission of Bartonella remains unknown.
On the basis of our phylogenetic inference, three species of Bartonella were identified (B. kosoyi, B. elizabethae, and B. phoceensis), as well as two unidentified clades from endemic mammal species (Eliurus minor and Nesogale dobsoni). To the best of our knowledge, this is the first detection of B. kosoyi in Madagascar. These three identified species of Bartonella were generally hosted by R. rattus, with B. kosoyi and B. elizabethae recognized as potential zoonotic agents [8, 39]. Furthermore, our study along with that conducted by Brook et al. [19] confirmed the presence of four potentially zoonotic Bartonella species (B. tribocorum, B. rattimassiliensis, B. elizabethae, and B. kosoyi) identified in R. rattus and their ectoparasites in Madagascar. Although no human cases of bartonellosis have been reported on the island, these pathogens constitute a potential zoonotic threat associated with anthropogenic pressure and climatic change. Ecological degradation increases the risk of contact between humans, reservoirs, and vectors, and facilitates the maintenance and transmission of vector-borne diseases such as bartonellosis. However, on Madagascar, our knowledge is limited of Bartonella epidemiology, its distribution, as well as genetic diversity of rodent-borne zoonotic diseases. Metagenomic analysis of rodent-associated pathogens for countries such as Madagascar are needed to elucidate the presence, abundance, and areas at risk of rodent-borne diseases. These different aspects taken together, and how little is known about bartonellosis risks in Madagascar, highlight the need for further study on the diversity and drivers of infection related to rodent-related zoonotic disease surveillance on the island and identify their potential impact on public health.
Conclusions
This study extends our knowledge on the prevalence and diversity of Bartonella species in small mammal and their ectoparasites in the Central Highlands of Madagascar. Molecular analyses confirmed the presence of Bartonella in four endemic small mammal species (Eliurus minor, E. majori, Microgale cowani, and Nesogale dobsoni), in one introduced species (Rattus rattus), and their associated fleas (Synopsyllus fonquerniei, Dinopsyllus brachypecten, Echidnophaga gallinacea, Pulex irritans, and Xenopsylla cheopis) with high prevalence in Eliurus minor, R. rattus, and S. fonquerniei. Two potential zoonotic agents (B. kosoyi and B. elizabethae) were identified in R. rattus and their fleas, highlighting their potential public health importance. Future work incorporating additional molecular markers and broader geographic sampling are essential to better assess the diversity of Bartonella species on the island and to achieve a more comprehensive understanding of their spatial distribution. Research should also evaluate the impact of environmental and anthropogenic factors on the maintenance and transmission of the bacterial genus through a multidisciplinary “One Health” approach and assess their potential impacts on public health.
Supplementary Information
Acknowledgements
We are grateful to the technical teams in the different study sites that helped with fieldwork. We also thank the Plague Unit of the Institut Pasteur de Madagascar for their help in the laboratory analysis.
Author contributions
BR, LAM, SMG, and MR designed the study methodology; MNJP, FR, and BR were responsible for data collection; LAM, MNJP, and BR performed data analysis; LAM, MNJP, FR, AA, LOR, VS, MR, SR, MR, DR, MR, SMG, and BR drafted the manuscript.
Funding
Financial support to conduct this work was graciously provided by Institut Pasteur de Madagascar, Antananarivo.
Availability of data and materials
All data analyzed during this study are included in this published article and its supplementary information files.
Declarations
Ethical approval and consent to participate
The study was conducted in strict accordance with the terms of research permission issued by Malagasy authority (Direction du Système des Aires Protégées, Direction Générale de l’Environnement et des Forêts) and based on a permit (no. 225/16/MEEF/ SG/DGF/DSAP/SCB.Re of 19 September 2016). Individual small mammals were manipulated and euthanized in accordance with guidelines accepted by the scientific community for the handling of wild animals [40]
Consent for publication
All of the authors contributed critically to the drafts and gave final approval for publication.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Meerburg BG, Singleton GR, Kijlstra A. Rodent-borne diseases and their risks for public health. Crit Rev Microbiol. 2009-35-221-70. 10.1080/10408410902989837. [DOI] [PubMed] [Google Scholar]
- 2.Krügel M, Król N, Kempf VAJ, Pfeffer M, Obiegala A. Emerging rodent-associated Bartonella: a threat for human health? Parasit Vectors. 2022;15:113. 10.1186/s13071-022-05162-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Mogollon-Pasapera E, Otvos L, Giordano A, Cassone M. Bartonella: emerging pathogen or emerging awareness? Int J Infect Dis. 2009;13:3-8. 10.1016/j.ijid.2008.04.002. [DOI] [PubMed] [Google Scholar]
- 4.Gutiérrez R, Krasnov B, Morick D, Gottlieb Y, Khokhlova IS, Harrus S. Bartonella infection in rodents and their flea ectoparasites: an overview. Vector Borne Zoonotic Dis. 2015;15:27–39. 10.1089/vbz.2014.1606. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Jin X, Gou Y, Xin Y, Li J, Sun J, Li T, et al. Advancements in understanding the molecular and immune mechanisms of Bartonella pathogenicity. Front Microbiol. 2023; 14:1196700. 10.3389/fmicb.2023.1196700. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Jiyipong T, Morand S, Jittapalapong S, Rolain JM. Bartonella spp. infections in rodents of Cambodia, Lao PDR, and Thailand: identifying risky habitats. Vector Borne Zoonotic Dis. 2015;15:48–55. 10.1089/vbz.2014.1621. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Okaro U, Addisu A, Casanas B, Anderson B. Bartonella species, an emerging cause of blood-culture-negative endocarditis. Clin Microbiol Rev. 2017;30:709-46. 10.1128/CMR.00013-17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Jiyipong T, Jittapalapong S, Morand S, Rolain JM. Bartonella species in small mammals and their potential vectors in Asia. Asian Pac J Trop Biomed. 2014;4:757-67. 10.12980/apjtb.4.2014c742. [Google Scholar]
- 9.Buffet JP, Kosoy M, Vayssier-Taussat M. Natural history of Bartonella-infecting rodents in light of new knowledge on genomics, diversity and evolution. Future Microbiol. 2013;8:1117-28. 10.2217/fmb.13.83. [DOI] [PubMed] [Google Scholar]
- 10.Genus Bartonella. List of Prokaryotic names with Standing in Nomenclature (LPSN). https://lpsn.dsmz.de/genus/bartonella. (Accessed 09 Dec 2025).
- 11.Ganzhorn JU, Porter P, Lowry II, Schatz GE, Sommer S. The biodiversity of Madagascar: one of the world’s hottest hotspots on its way out. Oryx. 2001;35:346-8. 10.1046/j.1365-3008.2001.00201.x. [Google Scholar]
- 12.Tortosa P. Introducing microbes in the context of the Madagascar biodiversity hotspot. In: Goodman SM, Jungers WL, editors. The new natural history of Madagascar. Princeton: Princeton University Press; 2022. p. 265-7. [Google Scholar]
- 13.Dietrich M, Gomard Y, Cordonin C, Tortosa P. Leptospira bacteria on Madagascar. In: Goodman SM, Jungers WL, editors. The new natural history of Madagascar. Princeton: Princeton University Press; 2022. p. 268-77. [Google Scholar]
- 14.Héraud JM, Andriamandimby SF, Olive MM, Guis H, Rasamoelina VM, Tantely L. Arthropod-borne viruses of Madagascar. In: Goodman SM, Jungers WL, editors. The new natural history of Madagascar. Princeton: Princeton University Press; 2022. p. 285-91. [Google Scholar]
- 15.Wilkinson D, Mavingui P. Arthropod-borne bacteria metabarcoding. In: Goodman SM, Jungers WL, editors. The new natural history of Madagascar. Princeton: Princeton University Press; 2022. p. 291-3. [Google Scholar]
- 16.Ramasindrazana B, Rasoanoro M, Ranaivoson HC, Randrianarivelojosia M, Tortosa P, Goodman SM. Blood parasites of small mammals on Madagascar. In: Goodman SM, Jungers WL, editors. The new natural history of Madagascar. Princeton: Princeton University Press; 2022. p. 294-7. [Google Scholar]
- 17.Rasambainarivo F, Zohdy S. Pathogen pollution: pathogen transmission between introduced and endemic species on Madagascar. In: Goodman SM, Jungers WL, editors. The new natural history of Madagascar. Princeton: Princeton University Press; 2022. p. 298-310. [Google Scholar]
- 18.Brook CE, Bai Y, Dobson AP, Osikowicz LM, Ranaivoson HC, Zhu Q, et al. Bartonella spp. in fruit bats and blood-feeding ectoparasites in Madagascar. PLoS Negl Trop Dis. 2015;9:e0003532. 10.1371/journal.pntd.0003532. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Brook CE, Bai Y, Yu EO, Ranaivoson HC, Shin H, Dobson AP, et al. Elucidating transmission dynamics and host-parasite-vector relationships for rodent-borne Bartonella spp. in Madagascar. Epidemics. 2017;20:56-66. 10.1016/j.epidem.2017.03.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Ehlers J, Krüger A, Rakotondranary SJ, Ratovonamana RY, Poppert S, Ganzhorn JU, et al. Molecular detection of Rickettsia spp., Borrelia spp., Bartonella spp. and Yersinia pestis in ectoparasites of endemic and domestic animals in southwest Madagascar. Acta Trop. 2020;205:105339. 10.1016/j.actatropica.2020.105339. [DOI] [PubMed] [Google Scholar]
- 21.Harimalala M, Ramihangihajason TR, Rakotobe Harimanana R, Girod R, Duchemin JB. Illustrated morphological keys for fleas (Siphonaptera) in Madagascar. J Med Entomol. 2021;58:1701-16. 10.1093/jme/tjab023. [DOI] [PubMed] [Google Scholar]
- 22.Uilenberg G, Hoogstraal H, Klein JM. Les tiques (Ixodea) de Madagascar et leur rôle vecteur. Institut Pasteur de Madagascar, Antananarivo. 2021;58:1701-16.
- 23.Soarimalala V, Goodman SM. Les petits mammifères de Madagascar. Antananarivo: association Vahatra; 2011. p.176.
- 24.Parany MNJ, Stenseth NC, Rasoamalala F, Rahelinirina S, Rahajandraibe S, Andrianaivoarimanana V, et al. Plague in small mammals from an endemic focus of the Malagasy Central Highlands: a longitudinal survey with a special reference on black rats (Rattus rattus). Integr Zool. 2025;21:37-47. 10.1111/1749-4877.12944. [DOI] [PubMed] [Google Scholar]
- 25.Rahelinirina S, Duplantier JM. Suivi mensuel de la dynamique des populations de rats noirs (Rattus rattus) dans les foyers de peste de la région de Mandoto. Rongeurs et lutte anti-murine à Madagascar : recueil des exposés. 1997. p. 91-107.
- 26.Billeter SA, Cáceres AG, Gonzales-Hidalgo J, Luna-Caypo D, Kosoy MY. Molecular detection of Bartonella species in ticks from Peru. J Med Entomol. 2011;48:1257-60. 10.1603/ME10240. [DOI] [PubMed] [Google Scholar]
- 27.Biomatters. Geneious Prime, version 2024.0.7. Auckland: Biomatters Ltd.; 2024. Available from: https://www.geneious.com (Accessed 12 Jul 2024)
- 28.Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ. Basic local alignment search tool. J Mol Biol. 1990;215:403-10. 10.1016/S0022-2836(05)80360-2. [DOI] [PubMed] [Google Scholar]
- 29.Darriba D, Taboada GL, Doallo R, Posada D. jModelTest 2: more models, new heuristics and parallel computing. Nat Methods. 2012;9:772. 10.1038/nmeth.2109. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Kumar S, Stecher G, Li M, Knyaz C, Tamura K. MEGA X: molecular evolutionary genetics analysis across computing platforms. Mol Biol Evol. 2018;35:1547-9. 10.1093/molbev/msy096. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.R Core Team. R: a language and environment for statistical computing. Vienna: R foundation for statistical computing; 2023. https://www.R-project.org/
- 32.Torre I, Balčiauskas L. The abundance and dynamics of small mammals and their predators: an editorial. Life. 2023;14:41. 10.3390/life14010041. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Goodman SM, Soarimalala V. Introduction to mammals. In: Goodman SM, Jungers WL, editors. The New Natural History of Madagascar. Princeton: Princeton University Press; 2022. p. 1737–69. [Google Scholar]
- 34.Goodman SM. Rattus on Madagascar and the dilemma of protecting the endemic rodent fauna. Conserv Biol. 1995;9:450-3. 10.1046/j.1523-1739.1995.9020450.x. [Google Scholar]
- 35.Ramasindrazana B, Parany MNJ, Rasoamalala F, Rasoanoro M, Rahajandraibe S, Vogler AJ, et al. Local-scale diversity of Yersinia pestis: a case study from Ambohitromby, Ankazobe District, Madagascar. Zoonoses Public Health. 2022;69:61-70. 10.1111/zph.12892. [DOI] [PubMed] [Google Scholar]
- 36.Krügel M, Pfeffer M, Król N, Imholt C, Baert K, Ulrich RG, et al. Rats as potential reservoirs for neglected zoonotic Bartonella species in Flanders, Belgium. Parasit Vectors. 2020;13:235. 10.1186/s13071-020-04098-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Harms A, Dehio C. Intruders below the radar: molecular pathogenesis of Bartonella spp. Clin Microbiol Rev. 2012;25:42-78. 10.1128/CMR.05009-11. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Schülein R, Seubert A, Gille C, Lanz C, Hansmann Y, Piémont Y. Invasion and persistent intracellular colonization of erythrocytes: a unique parasitic strategy of the emerging pathogen Bartonella. J Exp Med. 2001;193:1077-86. 10.1084/jem.193.9.1077. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39.Gutiérrez R, Shalit T, Markus B, Yuan C, Nachum-Biala Y, Elad D, et al. Bartonella kosoyi sp. nov. and Bartonella krasnovii sp. nov., two novel species closely related to the zoonotic Bartonella elizabethae, isolated from black rats and wild desert rodent-fleas. Int J Syst Evol Microbiol. 2020;70:1656-65. 10.1099/ijsem.0.003952. [DOI] [PubMed] [Google Scholar]
- 40.Sikes RS. 2016 guidelines of the American Society of Mammalogists for the use of wild mammals in research and education. J Mammal. 2016;97:663-88. 10.1093/jmammal/gyw078. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
All data analyzed during this study are included in this published article and its supplementary information files.