Metagenomic profile of the bacterial communities associated with Ixodes granulatus (Acari: Ixodidae): a potential vector of tick-borne diseases

• Published in: Journal of medical entomology Vol. 60; no. 4; pp. 753 - 768
• Main Authors: Che Lah, Ernieenor Faraliana, Ahamad, Mariana, Dmitry, Apanaskevich, Md-Zain, Badrul Munir, Yaakop, Salmah
• Format: Journal Article
• Language: English
• Published: US Entomological Society of America 12.07.2023; Oxford University Press
• Subjects: Acari; Animals; Arachnids; Bacteria; bacterial; Borrelia; Borrelia - genetics; Coxiellaceae; Ehrlichia; Female; Granulation; Health aspects; Humans; Ixodes - microbiology; Ixodes granulatus; Ixodidae - microbiology; Medical research; Medicine, Experimental; Metagenomics; Microbial activity; Microbiomes; Microorganisms; Next-generation sequencing; Parasitic diseases; Public health; Recreation areas; Ribosomal RNA; Rickettsia - genetics; Rickettsiales; rRNA 16S; Spirochaetales; Tick-borne diseases; Tick-Borne Diseases - microbiology; Ticks; vector; VECTOR/PATHOGEN/HOST INTERACTION, TRANSMISSION; Canada; Malaysia; Thailand; Japan; Germany; next-generation sequencing; vector; bacterial; Ixodes granulatus; Borrelia
• ISSN: 0022-2585; 1938-2928
• DOI: 10.1093/jme/tjad044

Ixodes granulatus Supino, 1897 (Acari: Ixodida) is one of Malaysia's most common hard ticks and is a potential vector for tick-borne diseases (TBDs). Despite its great public health importance, research on I. granulatus microbial communities remains largely unexplored. Therefore, this study aimed to investigate the bacterial communities of on-host I. granulatus collected from three different recreational areas on the East Coast of Peninsular Malaysia using high throughput Next Generation Sequencing (NGS). A total of 9 females on-host I. granulatus were subjected to metabarcoding analysis targetingV3–V4 regions of 16S ribosomal RNA (rRNA) using the Illumina MiSeq platform.This study identified 15 bacterial phyla corresponding to 19 classes, 54 orders, and 90 families from 435 amplicon sequence variants (ASVs), revealing a diverse bacterial community profile. Together with 130 genera assigned, local I. granulatus harbored 4 genera of pathogens, i.e., Rickettsia da Rocha Lima, 1916 (Rickettsiales: Rickettsiaceae) (58.6%), Borrelia Swellengrebel 1907 (Spirochaetales: Borreliaceae) (31.6%), BorreliellaAdeolu and Gupta 2015 (Spirochaetales: Borreliaceae) (0.6%), and Ehrlichia Cowdria Moshkovski 1947 (Rickettsiales: Ehrlichiaceae) (39.9%). Some endosymbiont bacteria, such as Coxiella (Philip, 1943) (Legionellales: Coxiellaceae), Wolbachia Hertig 1936 (Rickettsiales: Ehrlichiaceae), and Rickettsiella Philip, 1956 (Legionellales: Coxiellaceae), were also detected at very low abundance. Interestingly, this study reported the co-infection of Borrelia and Ehrlichia for the first time, instilling potential health concerns in the context of co-transmission to humans, especially in areas with a high population of I. granulatus.This study successfully characterized the tick microbiome and provided the first baseline data of I. granulatus bacterial communities in Malaysia.These results support the need for way-forward research on tick-associated bacteria using NGS, focusing on medically important species toward TBD prevention.