Bat Flies of the Family Streblidae (Diptera: Hippoboscoidea) Host Relatives of Medically and Agriculturally Important “Bat-Associated” Viruses

Abstract

Bat flies (Hippoboscoidea: Nycteribiidae and Streblidae) are obligate hematophagous ectoparasites of bats. We collected streblid bat flies from the New World (México) and the Old World (Uganda), and used metagenomics to identify their viruses. In México, we found méjal virus (Rhabdoviridae; Vesiculovirus), Amate virus (Reoviridae: Orbivirus), and two unclassified viruses of invertebrates. Méjal virus is related to emerging zoonotic encephalitis viruses and to the agriculturally important vesicular stomatitis viruses (VSV). Amate virus and its sister taxon from a bat are most closely related to mosquito- and tick-borne orbiviruses, suggesting a previously unrecognized orbivirus transmission cycle involving bats and bat flies. In Uganda, we found mamucuso virus (Peribunyaviridae: Orthobunyavirus) and two unclassified viruses (a rhabdovirus and an invertebrate virus). Mamucuso virus is related to encephalitic viruses of mammals and to viruses from nycteribiid bat flies and louse flies, suggesting a previously unrecognized orthobunyavirus transmission cycle involving hippoboscoid insects. Bat fly virus transmission may be neither strictly vector-borne nor strictly vertical, with opportunistic feeding by bat flies occasionally leading to zoonotic transmission. Many “bat-associated” viruses, which are ecologically and epidemiologically associated with bats but rarely or never found in bats themselves, may actually be viruses of bat flies or other bat ectoparasites.

The complete mitochondrial genomes and phylogenetic analysis of two Nycteribiidae bat flies (Diptera: Hippoboscoidea)

“…As ectoparasites of bats, the bat flies are important vectors of medically and agriculturally important ‘bat-associated’ viruses (Ramírez-Martínez et al. 2021 ) and microorganisms (Morse et al. 2012 ; Szentiványi et al.…”

Revising the paradigm: Are bats really pathogen reservoirs or do they possess an efficient immune system?

“…Moreover, many of the reported isolations are unconvincing: (1) Several viruses were only isolated from a single individual bat ( Charlier et al., 2002 ); (2) In some cases isolation was performed from a homogenate of internal tissues from which transmission is unlikely (e.g., the liver and spleen) and not from oral swabs or saliva glands, urine, feces, or even blood or sera. ( Mortlock et al., 2015 ; Hayman, 2016 ); (3) Several of the local viruses were also isolated from other animals in the region, including non-bat-specific ectoparasites ( Ramírez-Martínez et al., 2021 ); and (4) Some isolations were taken from sick or dead individuals ( Osborne et al., 2003 ; Kuzmin et al., 2010 ), which would probably not have transmitted the disease—sick bats have been shown to remain in the roost and refrain from social interactions ( Moreno et al., 2021 ). Seroprevalence by itself doesn’t reflect the ability or even the potential for being a reservoir or creating spillover events ( Barrantes Murillo et al., 2022 ).…”

“…Found in bedbugs as well. ( Osborne et al., 2003 ; Williams et al., 1976 ) 10 Japanaut virus Bunyaviridae, unassigned no yes no ( Fagre et al., 2019 ; Ramírez-Martínez et al., 2021 ) 11 Ife virus Bunyaviridae, unassigned yes no yes ( Kemp et al., 1988 ; Fagre et al., 2019 ) 12 Fomede virus Bunyaviridae, unassigned yes yes no ( Fagre et al., 2019 ) 13 Bangui virus Bunyaviridae, unassigned no no yes ( Mourya et al., 2014 ) 14 SARS virus Coronaviridae, Betacoronavirus no no no The overall nucleotide sequence identity between Sars Like-CoV and SARS-CoV T was 94%. ( Drexler et al., 2014 ; Banerjee et al., 2019 ) we suggest caution with conclusions on the zoonotic potential of bat viruses, based only on genomic sequence data.…”

Remarkably low host specificity in the bat fly Penicillidia fulvida (Diptera: Nycteribiidae) as assessed by mitochondrial COI and nuclear 28S sequence data

“…As obligate parasites feeding exclusively on bat blood, bat flies warrant increased attention as potential vectors of these pathogens [29]. Bat flies have been identified as vectors of protozoan parasites [30] and bacterial pathogens in genus Bartonella [31,32], and have recently been found to harbor bat-associated viruses related to medically impactful zoonoses [33][34][35].…”