Haemoplasma Prevalence and Diversity in Three Invasive Rattus Species from Gauteng Province, South Africa

Invasive Rattus species are carriers of haemotropic Mycoplasmas (haemoplasmas) globally, but data from Africa are lacking. Using a PCR-sequencing approach, we assessed haemoplasma prevalence and diversity in kidney and buccal swabs collected from three invasive Rattus species (Rattus rattus, R. norvegicus and R. tanezumi) in Gauteng Province, South Africa. Whilst the overall sequence-confirmed haemoplasma prevalence was 38.4%, infection rates in R. rattus (58.3%) were significantly higher (χ2 = 12.96; df = 2; n = 99 p < 0.05) than for R. tanezumi (14.3%). Differences between host sex (χ2 = 3.59 × 10−31; df = 1; n = 99; p = 1.00) and age (χ2 = 4.28; df = 2; n = 99; p = 0.12) were not significant. Whilst buccal (1.01%) and ectoparasite positivity (2.13%) were low, these results suggest that multiple transmission routes are possible. Three phylogenetically distinct lineages, consistent with global rat-associated strains described to date, were detected, namely, ‘Candidatus Mycoplasma haemomuris subsp. Ratti’, and two Rattus-specific haemoplasmas that are yet to be formally described. These results expand the known distribution of invasive rat-associated haemoplasmas and highlight the potential for pathogen co-invasion of new territories together with invading rodent hosts.