Prevalence and diversity of gastrointestinal pathogens in native and invasive New Zealand lizards

The rainbow skink (<i>Lampropholis delicata</i>) is the only invasive reptile in New Zealand, and its role in disease ecology with native lizards is unknown. We investigated the prevalence and diversity of <i>Salmonella </i>species<i> </i>and <i>Cryptosporidium </i>species<i> </i>in native lizards and <i>L. delicata</i>. Fifty-five <i>L. delicata </i>and 355 native lizards of eight species were sampled from three locations in 2021. <i>Salmonella </i>was detected in 4.4% (95% confidence interval 2.6-7.4%) of native lizards and two serovars were identified. <i>Cryptosporidium</i> was detected in native lizards at a prevalence of 31.3% (CI, 26.2-37.0%) and included mostly <i>C. parvum </i>of five subtypes and a single sample of <i>C. cuniculus</i>. No<i> </i>pathogens<i> </i>were<i> </i>detected in <i>L. delicata, </i>even in locations where the species overlapped with native lizards carrying these pathogens. Native lizards were more likely to be carrying gastrointestinal pathogens in areas where <i>L. delicata </i>was present, suggesting their fitness may be decreased in these areas. We conclude that native lizards, particularly skinks, are wildlife reservoirs for gastrointestinal pathogens of zoonotic concern.