Reverse-zoonotic infections of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) from humans to wildlife species internationally raise concern over the emergence of new variants in animals. A better understanding of the transmission dynamics and pathogenesis in susceptible species will mitigate the risk to humans and wildlife occurring in Africa. Here we report infection of an exotic puma (July 2020) and three African lions (July 2021) in the same private zoo in Johannesburg, South Africa. One Health genomic surveillance identified transmission of a Delta variant from a zookeeper to the three lions, similar to those circulating in humans in South Africa. One lion developed pneumonia while the other cases had mild infection. Both the puma and lions remained positive for SARS-CoV-2 RNA for up to 7 weeks.
A high prevalence of G12 rotavirus strains has previously been reported in southern Mozambique. In this study, the full genomes of five Mozambican G12 strains were determined directly from stool using an Illumina Miseq platform. One sample (0060) contained an intergenogroup co-infection of a G12P[8] Wa-like strain and a GXP[14] DS-1-like strain. The sequences of seven genome segments, detected for the GXP[14] strain, clustered with a diverse group of mostly animal strains, suggesting co-infection with a strain of possible animal origin. The stool samples contained G12P[6] rotavirus strains with Wa-like backbones. Phylogenetic analyses of the VP4 and VP7 encoding segments of the G12P[6] strains suggested that they were reassortants containing backbones that are similar to that of the G12P[8] strain. The study confirms previous observations of interspecies transmission and emphasizes the importance of whole-genome sequencing in order to evaluate rotavirus co-infections and reassortants.
1 November 2020 in Infection, Genetics and Evolution
Rotaviruses (RVs) are known to infect various avian and mammalian hosts, including swine. The most common RVs associated with infection in pigs are A, B, C and H (RVA-C; RVH). In this study we analysed rotavirus strains circulating on a porcine farm in the Western Cape province of South Africa over a two-year period. Whole genomes were determined by sequencing using Illumina MiSeq without prior genome amplification. Fifteen RVA genomes, one RVB genome and a partial RVC genome were identified. Phylogenetic analyses of the RVA data suggested circulation of one dominant strain (G5-P[6]/P[13]/P[23]-I5-R1-C1-M1-A8-N1-T7-E1-H1), typical of South African porcine strains, although not closely related to previously detected South African porcine strains. Reassortment with three VP4-encoding P genotypes was detected. The study also reports the first complete RVB genome (G14-P[5]-I13-R4-C4-M4-A10-T4-E4-H7) from Africa. The partial RVC (G6-P[5]-IX-R1-C1-MX-A9-N6-T6-EX-H7) strain also grouped with porcine strains. The study shows the continued circulation of an RVA strain, with a high reassortment rate of the VP4-encoding segment, on the porcine farm. Furthermore, incidents of RVB and RVC on this farm emphasize the complex epidemiology of rotavirus in pigs.
This study presents whole genomes of seven bovine rotavirus strains from South Africa and Mozambique. Double-stranded RNA, extracted from stool samples without prior adaptation to cell culture, was used to synthesise cDNA using a self-annealing anchor primer ligated to dsRNA and random hexamers. The cDNA was subsequently sequenced using an Illumina MiSeq platform without prior genome amplification. All strains exhibited bovine-like artiodactyl genome constellations (G10/G6-P[11]/P[5]-I2-R2-C2-M2-A3/A11/A13-N2-T6-E2-H3). Phylogenetic analysis revealed relatively homogenous strains, which were mostly related to other South African animal strains or to each other. It appears that these study strains represent a specific bovine rotavirus population endemic to Southern Africa that was derived through multiple reassortment events. While one Mozambican strain, MPT307, was similar to the South African strains, the second strain, MPT93, was divergent from the other study strains, exhibiting evidence of interspecies transmission of the VP1 and NSP2 genes. The data presented in this study not only contribute to the knowledge of circulating African bovine rotavirus strains, but also emphasise the need for expanded surveillance of animal rotaviruses in African countries in order to improve our understanding of rotavirus strain diversity.
Mozambique introduced the Rotarix® vaccine into the National Immunization Program in September 2015. Following vaccine introduction, rotavirus A (RVA) genotypes, G9P[4] and G9P[6], were detected for the first time since rotavirus surveillance programs were implemented in the country. To understand the emergence of these strains, the whole genomes of 47 ELISA RVA positive strains detected between 2015 and 2018 were characterized using an Illumina MiSeq-based sequencing pipeline. Of the 29 G9 strains characterized, 14 exhibited a typical Wa-like genome constellation and 15 a DS-1-like genome constellation. Mostly, the G9P[4] and G9P[6] strains clustered consistently for most of the genome segments, except the G- and P-genotypes. For the G9 genotype, the strains formed three different conserved clades, separated by the P type (P[4], P[6] and P[8]), suggesting different origins for this genotype. Analysis of the VP6-encoding gene revealed that seven G9P[6] strains clustered close to antelope and bovine strains. A rare E6 NSP4 genotype was detected for strain RVA/Human-wt/MOZ/HCN1595/2017/G9P[4] and a genetically distinct lineage IV or OP354-like P[8] was identified for RVA/Human-wt/MOZ/HGJM0644/2015/G9P[8] strain. These results highlight the need for genomic surveillance of RVA strains detected in Mozambique and the importance of following a One Health approach to identify and characterize potential zoonotic strains causing acute gastroenteritis in Mozambican children.