A Polymerase Chain Reaction Strategy for the Diagnosis of Camelpox

Abstract

Abstract. Camelpox is a contagious viral skin disease that is mostly seen in young camels. The disease is caused by the Camelpox virus (CMLV). In the present study, a polymerase chain reaction (PCR) assay based on the C18L gene (encoding ankyrin repeat protein) and a duplex PCR based on the C18L and DNA polymerase (DNA pol ) genes were developed. The former assay yields a specific amplicon of 243 bp of the C18L gene, whereas the duplex PCR yields 243-and 96-bp products of the C18L and DNA pol genes, respectively, in CMLV, and only a 96-bp product of the DNA pol gene in other orthopoxviruses. The limit of detection was as low as 0.4 ng of viral DNA. Both PCR assays were employed successfully for the direct detection and differentiation of CMLV from other orthopoxviruses, capripoxviruses, and parapoxviruses in both cell culture samples and clinical material. Furthermore, a highly sensitive SYBR Green dye-based, realtime PCR was optimized for quantitation of CMLV DNA. In the standard curve of the quantitative assay, the melting temperature of the specific amplicon at 77.6uC with peak measured fluorescence in dissociation plot was observed with an efficiency of 102%. To the authors' knowledge, this is the first report to describe a C18L gene-based PCR for specific diagnosis of camelpox infection.

Camelpox and Buffalopox: Two Emerging and Re-emerging Orthopox Viral Diseases of India

“…In recent times, PCR based on species specific C18L gene have been utilized to distinguish CMLV from buffalopox virus (BPXV) and other OPVs (Balamurugan et al, 2009). OPV genus specific PCR based on A-type inclusion protein (ATIP) gene of CMLV yields 881 bp specific amplicon (Meyer et al 1994), while, PCR based on hemagglutinin (HA) -gene yields 1100 bp amplicon (Damaso et al, 2000).…”

Isolation and characterization of Indian isolates of camel pox virus

“…The incubation period varies from 4 to 15 days with an initial rise in temperature followed by papules on labia, vesicles, pustules, and finally formation of scabs. Camel pox infection is diagnosed based on clinical symptoms, isolation, and electron microscopy and differentiated from other orthopoxviruses (OPXVs) by employing either restriction enzyme analysis or C18L gene-based PCR (Balamurugan et al 2009). Various cell lines such as Hela, GMK-AH1, BSC-1, WISH, and Vero are being used for isolation of viruses.…”

Orthopoxviruses—Plagues of Mankind, Strategists in Immune Evasion, Teachers in Vaccination

“…Whether this lack of human disease is due to the absence of MPXV in rodents is unknown (Salzer et al 2013). Sporadic outbreaks of CMLV infections have been reported among camels from a wide range of countries in Asia and Africa, especially in the Middle East (Bahrain, Iran, Iraq, Oman, Saudi Arabia, United Arab Emirates and Yemen), in Africa (Algeria, Egypt, Ethiopia, Kenya, Mauritania, Morocco, Niger, Somalia and Sudan), and in Asia (Afghanistan, India, Pakistan, the Asian part of Russia, Turkmenistan, and United Arab Emirates) (Baxby 1972;Wernery and Kaaden 2002;Balamurugan et al 2009;Bhanuprakash et al 2010a;Touil et al 2012;Ayelet et al 2013). Although the occurrence of camelpox is reported frequently by field veterinarians and camel herders, and despite the fact that CMLV is genetically the closest known virus to VARV, the epidemiology of the disease remains poorly studied.…”

“…Since 2001, real-time PCRs have been developed (e.g. Czerny et al 2001;Kulesh et al 2004;Balamurugan et al 2009;Gavrilova et al 2010;Li et al 2010;Shchelkunov et al 2011;Venkatesan et al 2012a). A DNA oligonucleotide microarray with the TNF receptor gene crmB (Lapa et al 2002) and loopmediated isothermal amplification (LAMP) assays are alternative rapid methods for OPXV detection or differentiation (Iizuka et al 2009;Venkatesan et al 2012b).…”