Short communication Identification of avian strains of Pasteurella multocida in India by conventional and PCR assays S.B. Shivachandra * , A.A. Kumar, R. Gautam, Vijendra P. Singh, M.K. Saxena, S.K. Srivastava Division of Bacteriology and Mycology, Indian Veterinary Research Institute, Izatnagar-243122, UP, India Abstract The prevalence of capsular and somatic serotypes were studied among 123 Pasteurella multocida strains isolated from chickens (n = 94), ducks (22), quails (4), turkeys (2) and geese (1) from different geographical regions of India. All strains exhibited similar cultural and morphological characteristics. Ninety-two of the isolates belonged to serotype A:1, the most prevalent serotype, with serotypes A:3, A:1,3, D:3 and F:3 having two isolates each. Only one isolate was positive for serotypes A:4 and D:1. Twenty isolates were untyped. A multiplex capsular PCR assay generated amplicons of sizes 460, 1044, 657 and 854 bp in 106 isolates iden- tified as capsular serotype-A, 15 in serotype D and two in serotype F. Capsular types B and E were not detected in any of the avian isolates studied. The present findings suggest that a multiplex capsular PCR assay may be suitable for the rapid initial identification serotypes P. multocida during epidemiological studies of fowl cholera. Ó 2005 Elsevier Ltd. All rights reserved. Keywords: Avian; Pasteurella multocida; PCR Pasteurella multocida, a Gram-negative, nonmotile, coccobacillus known to affect a wide range of avian spe- cies including wild and domestic animals, has been con- sidered a highly variable pathogen due to the diversity observed among serotypes with respect to host predilec- tion, pathogenicity, biochemical, cultural and antigenic specificity (Carter and Chengappa, 1981). Five capsular serogroups (A, B, D, E and F) based on indirect hae- magglutination assay (IHA) (Carter, 1955) and 16 so- matic serogroups (1–16) based on agar gel precipitation test (Heddleston et al., 1972) are currently used for serotyping. Fowl cholera may result from infec- tion with strains of P. multocida of several capsular and somatic serotypes (Rhoades and Rimler, 1990). The diagnosis of fowl cholera is based on clinical signs, pathological findings and the isolation and identi- fication of P. multocida on the basis of its cultural and biochemical characteristics (Rimler and Glisson, 1997). Conventional methods of characterizing isolates of P. multocida are based on capsular and somatic serotyping, which are often time-consuming and do not type all strains (Rimler et al., 1998). More recently, DNA-based identification and typing systems are emerging as reli- able alternatives, providing results within a short time (Blackall and Miflin, 2000; Townsend et al., 2001). As- says based on the polymerase chain reaction (PCR) are becoming reliable alternatives for the identification of pathogens more quickly (Hunt et al., 2000; Blackall and Miflin, 2000). Recently, the multiplex capsular PCR typing system has been shown to provide a rapid, sensitive and highly type-specific identification method instead of the more complicated method of capsular serogrouping (Townsend et al., 2001). 1090-0233/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.tvjl.2005.05.007 * Corresponding author. Present address: Department of Biology, The Catholic University of America, 103 McCort Ward Hall, 620 Michigan Ave, NE, Washington, DC 20064, USA. Tel.: +1 301 755 3311; fax: +1 202 319 5721. E-mail address: shivachandra@cua.edu (S.B. Shivachandra). www.elsevier.com/locate/tvjl The Veterinary Journal 172 (2006) 561–564 The Veterinary Journal