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Bacteria of the genus Bartonella have been known as emerging zoonotic pathogens for several human diseases including cat scratch disease, Carrion's disease and trench fever. Numerous species of small mammals have been reported to play a role as a suitable reservoir to many pathogenic Bartonella. These infections are thought to be transmitted through blood-feeding arthropod vectors such as ticks, fleas and lice. The purpose of this study is to detect the presence of Bartonella species from tick samples collected from small mammals in mangrove forests of Peninsular Malaysia. Herein, 38 individual ticks and their small mammals host were evaluated for the presence of Bartonella DNA by conventional PCR targeting the 16S rRNA intergenic spacer region (ITS) and partial sequencing of 460 bp from this locususing Bartonella genus-specific primers. Two tick individuals from Dermacentor auratus and Haemaphysalis hystricis collected from Rattus tiomanicus (host), were PCR-positive for Bartonella DNA amplification. No Bartonella amplification was possible in other tick species (Amblyomma sp.). Phylogenetic analysis of ITS fragments demonstrated that the sequences from ticks were closely related to Bartonella phoceensis, a species that has been reported from black rats (Rattus rattus) in Australia. This is the first report of a Bartonella bacteria detected in ticks from small mammals in Malaysia. Further research should be warranted to investigate the transmission of Bartonella and the potential impact of this zoonotic pathogen in animals and humans as this mangrove ecosystem is significant for local economy and tourism.

Bartonella spp. prevalence in small mammals and their ectoparasites was investigated in Taiwan. Blood samples were obtained from 66 rats, 20 shrews, 276 mites (Laelaps spp.), 74 fleas (Xenopsylla cheopis), 81 lice (Polyplax spp.), and 47 ticks (41 Dermacentor spp. and 6 Ixodes spp.). Bartonellae were isolated or detected in 27 (31.4%) animals. Bartonella DNA was detected in 48 (64.9%) fleas and 11 (64.7%) pooled lice samples, but not in mite and tick samples. Bartonella phoceensis, B. queenslandensis, B. tribocorum, B. elizabethae, and B. rattimassiliensis were isolated or detected in bacteremic mammals. For the first time in Taiwan, B. tribocorum, B. elizabethae, B. queenslandensis, and a B. rochalimae-like strain were detected in fleas, and B. tribocorum, B. phoceensis, and B. rattimassiliensis were detected in lice obtained from small mammals. A broader range of Bartonella species was identified in the ectoparasites than in the small mammals.

To study the distribution and diversity of Bartonella in rodents from Thailand, 330 rodents belonging to 13 species were tested. The majority (80.6%) of rodents examined belonged to the genus Rattus. Bartonellae were cultured from 41.5% of the rodents with a wide range of prevalence by host species and regions. Sequencing of gltA revealed diverse Bartonella strains. Bartonellae from Rattus spp. belonged to 23 variants and clustered with Bartonella coopersplainensis, Bartonella elizabethae, Bartonella phoceensis, Bartonella rattimassiliensis, Bartonella tribocorum, and an unknown geno-group. Bartonellae from Bandicota spp. belonged to six variants and clustered with B. coopersplainensis, B. rattimassilliensis, and B. tribocorum. Three variants from Mus spp. clustered with B. coopersplainensis or B. rattimassilliensis. The only isolate from a Berylmys berdmorei fell into the B. tribocorum group. The observations highlight the need to study these agents for their role in human febrile illnesses of unknown etiology in Thailand and elsewhere in Asia.

Thirty-three isolates of Bartonella spp., including 11 isolates not belonging to previously known species, were isolated from 66 Rattus norvegicus subjects trapped in the city of Marseille, France. Based on seven different gene sequences, the 11 isolates were assigned to Bartonella rattimassiliensis sp. nov. and Bartonella phoceensis sp. nov.