Although many severe acute respiratory syndrome-like coronaviruses (SARS-like CoVs) have been identified in bats inC oronaviruses (CoVs) in the subfamily Coronavirinae are important pathogens of mammalian and avian animals and currently compose four genera: Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus (1). Members of Alphacoronavirus and Betacoronavirus are found exclusively in mammals, e.g., human CoV 229E, NL63, and OC43, and cause human respiratory diseases (2). A CoV is also the causative agent of severe acute respiratory syndrome (SARS), the first global human pandemic disease of the 21st century, which spread to 30 countries in five continents, resulting in Ͼ8,000 human cases with 774 deaths (3, 4). SARS CoV is a member of the Betacoronavirus genus and is largely distinct from previously known human CoVs OC43 and 229E (5-7). To identify the transmission source of SARS, largescale animal screening was implemented in May 2003, and several strains of SARS CoVs were isolated from nasal and/or fecal swabs of six masked palm civets (Paguma larvata) and one raccoon dog (Nyctereutes procyonoides) collected from a wet market in Shenzhen retailing wild animals for exotic foods (8). Their full genome sequences were 99.8% identical to that of human SARS CoV, and therefore civets were deemed to be an animal reservoir of this virus (8). Further serological studies over a larger area revealed that only civets in the market were SARS seropositive, while farmed civets were seronegative, indicating that civets likely became infected from an unknown source in wet markets, not in the farming environment (9). Moreover, a comprehensive analysis of cross-host

Bats are considered important animal reservoirs for many viruses pathogenic to humans. An approach based on viral metagenomics was used to study gut specimens from 78 insectivorous bats in Yunnan Province, China. Seventy-four reads were found to be related to group A rotavirus (RVA). Further reverse transcription-PCR screening and viral isolation on cell cultures confirmed the presence of a novel RVA strain, named RVA/Bat-tc/MSLH14/2012/G3P[3], in 1 (6%) of 16 lesser horseshoe bats. Full genomic sequencing analyses showed that MSLH14 possessed the genotype constellation G3-P[3]-I8-R3-C3-M3-A9-N3-T3-E3-H6, which is akin to human and animal rotaviruses believed to be of feline/canine origin. Phylogenetic analysis indicated that VP7 was most closely related to bovine RVA strains from India, whereas VP4 was most closely related to an unusual human RVA strain, CMH222, with animal characteristics isolated in Thailand. The remaining gene segments were only distantly related to a range of animal RVA strains, most of which are believed to be related to feline/canine RVAs. Experimental infection showed that bat RVA strain MSLH14 was highly pathogenic to suckling mice, causing 100% mortality when they were inoculated orally with a titer as low as 5 ؋ 10 2 50% tissue culture infective doses. As this virus is not closely related to any known RVA strain, it is tempting to speculate that it is a true bat RVA strain rather than a virus transmitted between species. However, further screening of bat populations, preferably juvenile animals, will be crucial in determining whether or not this virus is widely distributed in the bat population.

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Hantaviruses cause life-threatening diseases in human worldwide. Rodents, insectivores and bats are known hantaviral reservoirs, but lack of complete genomic sequences of bat-borne hantaviruses impedes phylogenetic and evolutionary comparison with those of rodents and insectivores. Here, a novel bat-borne hantavirus, Laibin virus (LBV), has been identified in a black-bearded tomb bat in China. The complete genomic sequence shows that LBV is only distantly related to all previously known bat-borne hantaviruses.