Molecular characterization of rotavirus isolated from alpaca (Vicugna pacos) crias with diarrhea in the Andean Region of Cusco, Peru

Abstract

Alpacas (Vicugna pacos), a species of South American camelids (SAC), suffer high morbidity and mortality from infectious diseases. Diarrhea is one of the leading causes of alpaca cria mortality in Peru and elsewhere. In order to develop appropriate control and/or treatment, it is necessary to identify infectious pathogens that cause diarrhea in crias. Rotavirus was isolated in cell culture from feces collected from crias with acute diarrhea that tested positive to rotaviral antigen by rapid immunochromatographic methods in an earlier study. The isolates were identified as rotaviruses by RT-PCR run with specific primers for human rotavirus VP7 coding sequences using total RNA extracted from cells displaying cytopathic effects as template. These alpaca isolates were further identified as group A rotaviruses by means of a VP6-specific PCR and were designated as ALRVA-K'ayra/Perú/3368-10 and ALRVA-K'ayra/Perú/3386-10. Molecular G and P typing, placed the former as G3/P11 and the latter as G3/P?. Sequence analysis of two genome segments (coding for VP4 and VP7) from the alpaca isolates revealed partial homologies to swine and human rotaviruses, respectively. These results demonstrate that rotaviruses are associated with a proportion of cases of diarrhea in crias, although prevalence and impact remain to be determined. The isolation of rotaviruses from alpaca crias with diarrhea will contribute positively to further understand the pathogen and its role in the diarrhea complex.

Keywords: Alpaca; Cria; Diarrhea; Group A rotavirus.

Fig. 1

Molecular characterization of alpaca rotavirus isolates. RNA extracted from cell culture isolates was amplified by RT-PCR using either VP7 sequence-specific primers (1A) or VP6 sequence specific primers (1B). (A and B) DNA ladder (M); ALRVA/K’ayra/Perú/3368-10, ALRVA/K’ayra/Perú/3386-10 (2, 3); negative control (4); NVSL bovine rotavirus (BRV) as positive control (5). (C) molecular G and P typing. ALRVA/K’ayra/ Perú/3368-10 and ALRVA/K’ayra/ Perú /3386-10 cDNAs amplified by PCR using P11/Con2 primer combination (2 and 3); negative control (4) or G3/END9 primer combination (5 and 6).