Mycoplasma and Bartonella in cats from the tropical tourist Gili Islands, Indonesia.

Bartonella spp. and haemotropic Mycoplasma spp. are important vector-borne bacteria of veterinary and zoonotic relevance, yet information on their circulation in Indonesian island ecosystems remains limited. We investigated their occurrence and molecular diversity in 117 domestic and free-roaming cats from the Gili Islands, Indonesia, using full-length 16S rRNA nanopore metagenomics followed by targeted PCR, sequencing, phylogenetic analysis and multilocus sequence typing (MLST). Bartonella DNA was detected in 18/117 (15.4%) cats and haemotropic Mycoplasma DNA in 40/117 (34.2%). Sequence analysis identified Bartonella henselae as the predominant species together with Bartonella clarridgeiae. MLST of B. henselae revealed three sequence types (ST1, ST16 and ST42), with ST1, a lineage reported in both feline and human isolates, predominating. Comparison with the PubMLST database showed significant geographical differences in the distribution of ST1 and ST42, supporting regional variation in the circulation of B. henselae lineages. Haemoplasma characterization identified Candidatus Mycoplasma haemominutum, Mycoplasma haemofelis, Candidatus Mycoplasma turicensis and a Mycoplasma feliminutum-like organism, comprising ten distinct sequence variants. Haemoplasma positivity was significantly associated with age, with adults showing higher positivity than younger animals (P < 0.001), whereas Bartonella infection was not associated with age, sex or island of origin. The detection of zoonotically relevant B. henselae lineages and the genetic diversity of feline haemoplasmas provide evidence of the circulation of vector-borne bacteria among cats in this tropical island ecosystem. These findings provide the first molecular epidemiological baseline for this region and contribute to understanding the circulation and genetic diversity of feline vector-borne pathogens in Southeast Asia.