Isolation and Identification of a Highly Divergent Kaeng Khoi Virus from Bat Flies (Eucampsipoda sundaica) in China

Abstract

Background: Kaeng Khoi virus (KKV), which belongs to the genus Orthobunyavirus, family Perbunyaviridae, was originally isolated from the brain tissue of bats and may cause infection in humans. In this study, the KKV strain WDBC1403 was isolated from bat flies (Eucampsipoda sundaica), ectoparasites of the bat Rousettus leschenaultia, collected from Yunnan Province of China at the Sino-Burmese border. Methods and Results: The bat fly specimens were ground and inoculated in culture cells. The WDBC1403 strain was shown to induce cytopathic effects in Vero, baby hamster kidney (BHK-21), and Tb1Lu cells, but not in C6/36 cells; however, viral gene amplification was detected in the supernatants of C6/36 cells. Using electron microscopy, the virus was determined to be spherical, enveloped, and 80-90 nm in diameter; it was also shown to form plaques in BHK-21 cells and the titer reached 1 • 10 6.57 plaque-forming units/mL 24 h after infection. The phylogenetic analysis showed that WDBC1403 is a KKV strain, but is independent of the original KKV strain (PSC-19). Viral genome analysis revealed that the nucleotide and amino acid sequence identities of the S, M, and L segments of WDBC1403 with PSC-19 were 88.2% and 96.1%, 76.7% and 85.0%, and 78.3% and 88.9%, respectively. Two amino acids were removed at the end of the open reading frame of the M segment, and 47 nucleotides were removed in the 3¢-untranslated region of the M segment of the WDBC1403 strain compared with the PSC-19 strain. Conclusions: The WDBC1403 strain is a highly divergent KKV strain, suggesting that there are a variety of KKV strains that exhibit molecular differences. Moreover, because of the large variations in nucleotide and amino acid sequence in the M segment, which encodes an important membrane protein, further research on antigenicity and pathogenicity in humans and animals is needed.

Parasitization of bats by bat flies (Streblidae) in fragmented habitats

“…The response of bats to habitat alteration has recently caused them to become the focus of several studies, in part due to their importance as model organisms for topics related to eco‐health and zoonoses (Brook & Dobson, ; Hiller, Rasche, et al, ; Streicker et al, ). However, the importance of parasites to affect host populations directly by controlling reproductive success, as well as their potential role as vectors for pathogens (Morse et al, ; Xu et al, ), is often neglected and severely understudied. While bat flies are known vectors of Polychromophilus blood parasites (Witsenburg et al, ), and bats react to infections with blood parasites with elevated white blood cell counts (Cottontail, Wellinghausen, & Kalko, ), consequences on bat health remain to be explored.…”

Bat Flies and Their Microparasites: Current Knowledge and Distribution

“…Most of the reports on viruses in bat flies are relatively recent (87, 92–96). As such, it is possible that the number of isolated viruses in bat ectoparasites might thus rise in the future with improvement in diagnostic methods.…”

“…Viruses are only known from bat flies infecting the New World leaf-nosed bats Phyllostomidae and the Old World fruit bats Pteropodidae, but observations are still scarce. These observed viruses represent distant groups, such as Dengue virus (family Flaviviridae ) isolated from the bat flies of the common vampire bat, Desmodus rotundus (87); Kaeng Khoi virus ( Peribunyaviridae ), Kanyawara virus ( Rhabdoviridae ), Mahlapitsi virus ( Reoviridae ), and Wolkberg virus ( Bunyaviridae ), isolated from Myonycteris and Rousettus species (92–96).…”

Current Arboviral Threats and Their Potential Vectors in Thailand

“…Overall, these results have important zoonotic implications for humans. [6], and may cause infections in humans [87]. KKV is a member of the genus Orthobunyavirus, Family Peribunyaviridae, Order Bunyavirales.…”

“…After the initial discovery, KKV has been reported in bat flies (Eucampsipoda sundaica) from China [89] and was isolated from dead bats (Chaerephon plicata) from Cambodia [90]. The original KKV strain (PSC-19) was isolated from bats (T. plicata (Buchannan)) in Thailand, while KKV strain WDBC1403 was isolated from bat flies (E. sundaica) in China [87,89,90], was presented the highly divergent KKV from bat flies [87]. Therefore, further research on antigenicity and pathogenicity in humans and animals is required.…”