Hokudai Center for Zoonosis Control in Zambia, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.
Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.
PLoS Negl Trop Dis. 2021 Sep 7;15(9):e0009768. doi: 10.1371/journal.pntd.0009768. eCollection 2021 Sep.
Pteropine orthoreovirus (PRV) is an emerging bat-borne zoonotic virus that causes severe respiratory illness in humans. Although PRVs have been identified in fruit bats and humans in Australia and Asia, little is known about the prevalence of PRV infection in Africa. Therefore, this study performed an PRV surveillance in fruit bats in Zambia.
Egyptian fruit bats (Rousettus aegyptiacus, n = 47) and straw-colored fruit bats (Eidolon helvum, n = 33) captured in Zambia in 2017-2018 were screened for PRV infection using RT-PCR and serum neutralization tests. The complete genome sequence of an isolated PRV strain was determined by next generation sequencing and subjected to BLAST and phylogenetic analyses. Replication capacity and pathogenicity of the strain were investigated using Vero E6 cell cultures and BALB/c mice, respectively.
An PRV strain, tentatively named Nachunsulwe-57, was isolated from one Egyptian fruit bat. Serological assays demonstrated that 98% of sera (69/70) collected from Egyptian fruit bats (n = 37) and straw-colored fruit bats (n = 33) had neutralizing antibodies against PRV. Genetic analyses revealed that all 10 genome segments of Nachunsulwe-57 were closely related to a bat-derived Kasama strain found in Uganda. Nachunsulwe-57 showed less efficiency in viral growth and lower pathogenicity in mice than another PRV strain, Miyazaki-Bali/2007, isolated from a patient.
A high proportion of Egyptian fruit bats and straw-colored fruit bats were found to be seropositive to PRV in Zambia. Importantly, a new PRV strain (Nachunsulwe-57) was isolated from an Egyptian fruit bat in Zambia, which had relatively weak pathogenicity in mice. Taken together, our findings provide new epidemiological insights about PRV infection in bats and indicate the first isolation of an PRV strain that may have low pathogenicity to humans.
果蝠正呼肠孤病毒（PRV）是一种新兴的蝙蝠传播的人畜共患病病毒，可导致人类严重的呼吸道疾病。尽管在澳大利亚和亚洲的果蝠和人类中已鉴定出 PRV，但对非洲 PRV 感染的流行情况知之甚少。因此，本研究在赞比亚对果蝠进行了 PRV 监测。
2017 年至 2018 年在赞比亚捕获的埃及果蝠（Rousettus aegyptiacus，n = 47）和棕果蝠（Eidolon helvum，n = 33）使用 RT-PCR 和血清中和试验筛查 PRV 感染。通过下一代测序确定分离的 PRV 株的完整基因组序列，并进行 BLAST 和系统发育分析。使用 Vero E6 细胞培养和 BALB/c 小鼠分别研究该菌株的复制能力和致病性。
从一只埃及果蝠中分离出一种 PRV 株，暂命名为 Nachunsulwe-57。血清学检测表明，从埃及果蝠（n = 37）和棕果蝠（n = 33）采集的 70 份血清中有 98%（69/70）具有针对 PRV 的中和抗体。遗传分析表明，Nachunsulwe-57 的所有 10 个基因组片段均与在乌干达发现的蝙蝠来源的 Kasama 株密切相关。Nachunsulwe-57 在病毒生长效率和对小鼠的致病性方面均低于从患者中分离出的另一种 PRV 株 Miyazaki-Bali/2007。
在赞比亚，发现相当比例的埃及果蝠和棕果蝠对 PRV 呈血清阳性。重要的是，从赞比亚的一只埃及果蝠中分离出了一种新的 PRV 株（Nachunsulwe-57），该株在小鼠中具有相对较弱的致病性。综上所述，我们的研究结果为蝙蝠中 PRV 感染提供了新的流行病学见解，并表明首次分离到对人类可能具有低致病性的 PRV 株。
