Sharif et al. Acta Veterinaria Scandinavica 2010, 52:1 http://www.actavetscand.com/content/52/1/1 B R I E F C O M M U N I C A T I O N Open Access Descriptive distribution and phylogenetic analysis of feline infectious peritonitis virus isolates of Malaysia Saeed Sharif1, Siti S Arshad1*, Mohd Hair-Bejo1, Abdul R Omar1, Nazariah A Zeenathul1, Lau S Fong2, Nor-Alimah Rahman3, Habibah Arshad2, Shahirudin Shamsudin2, Mohd-Kamarudin A Isa1 Abstract The descriptive distribution and phylogeny of feline coronaviruses (FCoVs) were studied in cats suspected of hav- ing feline infectious peritonitis (FIP) in Malaysia. Ascitic fluids and/or biopsy samples were subjected to a reverse transcription polymerase chain reaction (RT-PCR) targeted for a conserved region of 3’untranslated region (3’UTR) of the FCoV genome. Eighty nine percent of the sampled animals were positive for the presence of FCoV. Among the FCoV positive cats, 80% of cats were males and 64% were below 2 years of age. The FCoV positive cases included 56% domestic short hair (DSH), 40% Persian, and 4% Siamese cats. The nucleotide sequences of 10 selected ampli- fied products from FIP cases were determined. The sequence comparison revealed that the field isolates had 96% homology with a few point mutations. The extent of homology decreased to 93% when compared with reference strains. The overall branching pattern of phylogenetic tree showed two distinct clusters, where all Malaysian iso- lates fall into one main genetic cluster. These findings provided the first genetic information of FCoV in Malaysia. Findings Feline infectious peritonitis (FIP) is a highly fatal disease of cats caused by generalized infection with a feline cor- onavirus (FCoV). FCoVs belong to subgroup 1a of Coro- naviruses in the family Coronaviridae, order Nidovirales. Other members of this subgroup include porcine trans- missible gastroenteritis virus, canine coronavirus, rac- coon/dog coronavirus and Chinese ferret badger coronavirus [1,2]. FCoVs are enveloped, positive-strand RNA viruses with a large, capped and polyadenylated RNA genome of about 29 kb. The cap structure at the 5’ end of genome is followed by an untranslated region (UTR). At the 3’ end of the genome is another UTR of 275 nucleotides, followed by the poly (A) tail. The sequences of the both 3’- and 5’-UTR are important for RNA replication and transcription [3]. Two biotypes of FCoV are described in cats: feline infectious peritonitis virus (FIPV) and feline enteric cor- onavirus (FECV). Infection with FECV is usually unap- parent or manifested by a transient gastroenteritis. In * Correspondence: suri@vet.upm.edu.my 1Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia contrast, FIPV infection causes a fatal immune-mediated disease with a wide spectrum of clinical signs. FIP refers to the more common effusive (wet) form of the disease characterized by peritonitis and/or pleuritis. The effusive form is caused by complement-mediated vasculitis and results in inflammatory exudation into body cavities. In some FIP cases, partial cell-mediated immunity cause non-effusive (dry) form which is characterized by granu- lomatous involvement of various organs particularly central nervous system and eyes. However, the FIP forms can transform to each other [4-6]. It has been suggested that virulent FIPV arises by mutation from parental FECV in the individual, persistently infected host [4,7,8]. It is not yet clear which alterations in the FCoV genome are responsible for the generation of FIPV from FECV [3,6]. FIP occurs worldwide and is ubiquitous in virtually all cat populations [6]. The disease was reported as a major factor of kitten mortality in UK [9] and it is currently one of the leading infectious diseases causing death among young cats from shelters and catteries [6]. The first case of FIP in Malaysia was reported in 1981 [10] and the feature of cats with FIP were described in a © 2010 Sharif et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.