A multipronged next‐generation sequencing metabarcoding approach unearths hyperdiverse and abundant dog pathogen communities in Cambodia

Abstract

Recent surveys in Southeast Asia, including Cambodia, have identified canine vector‐borne pathogens (VBPs), including those with zoonotic potential, as highly prevalent. The lack of veterinary care alongside the close association semidomesticated dogs have with humans in the region exacerbates these zoonotic risks. Nonetheless, the number of studies investigating such pathogens and the threats they pose to dog and human health is limited. Here, we utilize a next‐generation sequencing (NGS)‐based metabarcoding protocol to conduct an assumption‐free characterization of the bacterial, apicomplexan, and kinetoplastid blood‐borne pathogens of free‐roaming dogs from across Cambodia. From 467 dogs at five field sites, 62% were infected with one of eight confirmed pathogens, comprising Anaplasma platys (32%), Ehrlichia canis (20%), Hepatozoon canis (18%), Babesia vogeli (14%), Mycoplasma haemocanis (13%), the zoonotic pathogen Bartonella clarridgeiae (3%), Candidatus Mycoplasma haematoparvum (0.2%), and Trypanosoma evansi (0.2%). Coinfections of between two and four VBPs were common with 28% of dogs found to have a mixed infection. Moreover, DNA from putatively infectious agents belonging to the bacterial family and genera Coxiella, Mycobacterium, Neisseria, Rickettsiaceae, Treponema, and two uncharacterized Mycoplasma species were identified, in addition to protozoan genera Colpodella, Parabodo, and Bodo. Using a multiple logistic regression model, the presence of ectoparasites, abnormal mucous membranes, anemia, and total protein were found as predictors of canine VBP exposure. This study represents the first time an NGS metabarcoding technique has been used to holistically detect the bacterial and protozoan hemoparasites communities of dogs through an in‐depth survey, highlighting the power of such methods to unearth a wide spectrum of pathogenic organisms in an unbiased manner.

Nanopore Sequencing Using the Full-Length 16S rRNA Gene for Detection of Blood-Borne Bacteria in Dogs Reveals a Novel Species of Hemotropic Mycoplasma

“…Hence, coinfection with VBB is not uncommon, making accurate diagnosis even more complex ( 11 ). To alleviate these issues, diagnostic methods capable of accurately detecting and characterizing VBB coinfections in a time-effective manner are essential, particularly in regions where canine pathogen diversity is high, such as the tropics ( 12 , 13 ).…”

High‐throughput microfluidic real‐time PCR for the simultaneous detection of selected vector‐borne pathogens in dogs in Bosnia and Herzegovina

“…Our identification of the haemotropic M. haematoparvum and M. haemocanis in Bosnian dogs, as well as A. platys , is also novel data that extends the known endemic geographical range of these canine VBPs. Although none of these pathogen species is associated with significant lethality in dogs, A. platys is the aetiological agent of infectious canine cyclic thrombocytopaenia, a disease known to exacerbate clinical signs in dogs when identified in the context of VBP coinfections (Gaunt et al., 2010; Huggins et al., 2022). In addition, haemotropic Mycoplasma spp.…”

Occurrence and bacterial loads of Bartonella and haemotropic Mycoplasma species in privately owned cats and dogs and their fleas from East and Southeast Asia

“…Nevertheless, direct transmission through bites and blood transfusion have also been described (Tasker, 2010; Willi et al, 2007). Few studies have investigated the occurrence of haemoplasmas in EA and SEA, and have reported high prevalence in community dogs (40%), stray cats (23% to 38%) and client‐owned cats (23%) and their fleas (34%) from Thailand (Assarasakorn et al, 2012; Do et al, 2020; Huggins et al, 2019; Kaewmongkol et al, 2017) as well as in free‐ranging dogs (~13%) from Cambodia (Huggins et al, 2021; Inpankaew et al, 2016).…”