Isolation and Characterization of Akhmeta Virus from Wild-Caught Rodents ( Apodemus spp.) in Georgia

Abstract

Akhmeta virus is a unique Orthopoxvirus that was described in 2013 from the country of Georgia. This paper presents the first isolation of this virus from small mammal (Rodentia; Apodemus spp.) samples and the molecular characterization of those isolates. The identification of the virus in small mammals is an essential component to understanding the natural history of this virus and its transmission to human populations and could guide public health interventions in Georgia. Akhmeta virus genomes harbor evidence suggestive of recombination with a variety of other orthopoxviruses; this has implications for the evolution of orthopoxviruses, their ability to infect mammalian hosts, and their ability to adapt to novel host species. In 2013, a novel orthopoxvirus was detected in skin lesions of two cattle herders from the Kakheti region of Georgia (country); this virus was named Akhmeta virus. Subsequent investigation of these cases revealed that small mammals in the area had serological evidence of orthopoxvirus infections, suggesting their involvement in the maintenance of these viruses in nature. In October 2015, we began a longitudinal study assessing the natural history of orthopoxviruses in Georgia. As part of this effort, we trapped small mammals near Akhmeta ( n = 176) and Gudauri ( n = 110). Here, we describe the isolation and molecular characterization of Akhmeta virus from lesion material and pooled heart and lung samples collected from five wood mice ( Apodemus uralensis and Apodemus flavicollis ) in these two locations. The genomes of Akhmeta virus obtained from rodents group into 2 clades: one clade represented by viruses isolated from A. uralensis samples, and one clade represented by viruses isolated from A. flavicollis samples. These genomes also display several presumptive recombination events for which gene truncation and identity have been examined. IMPORTANCE Akhmeta virus is a unique Orthopoxvirus that was described in 2013 from the country of Georgia. This paper presents the first isolation of this virus from small mammal (Rodentia; Apodemus spp.) samples and the molecular characterization of those isolates. The identification of the virus in small mammals is an essential component to understanding the natural history of this virus and its transmission to human populations and could guide public health interventions in Georgia. Akhmeta virus genomes harbor evidence suggestive of recombination with a variety of other orthopoxviruses; this has implications for the evolution of orthopoxviruses, their ability to infect mammalian hosts, and their ability to adapt to novel host species.