AUTHOR=Galay Remil L. , Llaneta Carina R. , Monreal Maria Karla Faye B. , Armero Antero L. , Baluyut Arianne Bel D. , Regino Czarina Marie F. , Sandalo Kristina Andrea C. , Divina Billy P. , Talactac Melbourne R. , Tapawan Lennox P. , Mojares Maarten Czar L. , Alvarez Cherry R. , Mago Emmanuel R. , Encarnacion Noemi D. , Andoh Masako , Tanaka Tetsuya 

TITLE=Molecular Prevalence of Anaplasma marginale and Ehrlichia in Domestic Large Ruminants and Rhipicephalus (Boophilus) microplus Ticks From Southern Luzon, Philippines

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.746705

DOI=10.3389/fvets.2021.746705

ISSN=2297-1769

ABSTRACT=<p>Anaplasmosis and ehrlichiosis are tick-borne rickettsial diseases that cause significant economic losses in the livestock industry worldwide. Although bovine anaplasmosis is known to be endemic in the Philippines, epidemiological data is fragmented. Moreover, little is known about bovine ehrlichiosis in the country. In this study, the prevalence of <italic>Anaplasma marginale</italic> and <italic>Ehrlichia</italic> in cattle and water buffalo from provinces in the southern part of Luzon, Philippines, was investigated through PCR. Blood samples from 620 animals comprised of 512 cattle and 108 water buffalo and 195 tick samples were subjected to nested PCR targeting the <italic>groESL</italic> gene of Anaplasmataceae. Positive samples were further subjected to another nested PCR and conventional PCR to amplify the <italic>A. marginale groEL</italic> gene and the <italic>Ehrlichia dsbA</italic> gene, respectively. Selected <italic>A. marginale</italic>-positive samples were also subjected to nested PCR targeting the <italic>msp5</italic> gene. Regardless of the animal host, the overall prevalence in blood samples obtained was 51.9% for Anaplasmataceae, 43% for <italic>A. marginale</italic>, and 1.1% for <italic>Ehrlichia</italic>. No water buffalo were positive for <italic>Ehrlichia</italic>. Meanwhile, 15.9, 6.7, and 2% of the tick samples, all morphologically identified as <italic>Rhipicephalus</italic> (<italic>Boophilus</italic>) <italic>microplus</italic>, were positive for Anaplasmataceae, <italic>A. marginale</italic>, and <italic>Ehrlichia</italic>, respectively. Sequence analysis of selected <italic>A. marginale msp5</italic> amplicons showed that the isolates from the region share 94–98% identity to reported <italic>A. marginale</italic> from other countries. The phylogenetic tree showed clustering of isolates in the region and a close relationship with <italic>A. marginale</italic> isolates from other countries. Sequences of <italic>Ehrlichia</italic> amplicons from cattle and ticks were 97–100% similar to reported <italic>Ehrlichia minasensis</italic> isolates. This study showed the high prevalence of <italic>A. marginale</italic> in Luzon, Philippines, and provided the first molecular evidence of <italic>E. minasensis</italic> in the country.</p>