Identification and molecular characterization of the infectious bursal disease virus (IBDV) from an outbreak in a broiler flock in midwestern Brazil

Abstract

In order to identify and characterize the agent of a suggestive clinical case of Gumboro disease (GD) that affected a 34-day-old broiler flock in Buriti Alegre (Goias State, Midwestern Brazil) in the year 2001, we carried out a combination of classic and modern virological methods. Histopathological analysis of the bursa revealed necrosis, presence of depleted follicles, some infiltration of heterophils, edema and formation of cystic cavities that are compatible with lesions observed in GD. Inoculation of embryonated eggs of specific pathogen-free (SPF) chickens with macerated bursa suspension resulted in embryo mortality and lesions which were also compatible with those caused by IBDV. A sample of bursa was submitted to a nested reverse transcriptase-polymerase chain reaction (RT-PCR) procedure to amplify the hypervariable region of the VP2 gene. The amplicon that was obtained from this sample (BR-GO) was digested with the restriction enzymes TaqI, StyI and SspI, but not with SacI, a pattern similar to that observed with very virulent IBDV (vvIBDV) strains. Furthermore, nucleotide sequence analysis revealed alanine, isoleucine, and isoleucine at amino acid positions 222, 256, and 294, respectively, which are also found in vvIBDV strains. Finally, phylogenetic analysis grouped BR-GO isolate with other vvIBDV strains.

Genotypic characterization of Indian isolates of infectious bursal disease virus strains by reverse transcription-polymerase chain reaction combined with restriction fragment length polymorphism analysis

“…Loss of SacI RE site off ered a rapid method of RFLP analysis and proved that RT-PCR/RFLP was simple and a sensitive method for detection of genetic variation among isolates that are closely related serologically. Our study is also in agreement with Sellers et al (1999) andDe Paula et al (2004) that the SacI site is present only in cvIBDV. Th e SacI RE site might have been introduced into the genome of cvIBDV strain by silent mutation at the nucleotide position 867 (Zierenberg et al, 2001).…”

“…Our result was in accordance with Shoshtari et al (2004) as they reported that only vvIBDV had single site for SspI enzyme. De Paula et al (2004) reported that an amino acid substitution was observed in the SspI site in non-vvIBDV strains. Juneja et al (2008) reported the presence of SspI restriction enzyme site in all the fi eld isolates and not in vaccine strain (Lin et al, 1993;Hoque et al, 2001).…”

Sequence analysis of VP2 hypervariable region of the field isolates of infectious bursal disease viruses from southern region of India

“…De Paula et al (2004) also reported the presence of serine at position 299 in BR-GO strain (Brazil). However, they didn't observe this change exclusively in all vvIBDV strains.…”

Viral Agents Associated With Retarded Growth in Broiler Chickens

“…Significant decrease in FCR observed in all groups when compared with control group, FCR was 3.55 ±0.058, 3.42 ± 0.047, 3.4 ± 0.04, %and 1.99 ± 0.023 %) in all groups these results agreed with Okoye and Aba Adulugba (1998). ; and Paula et al (2004) they mentioned that birds survived the diseases lost weight from 1190 to 1320 g (Group I) than those broilers which did not have Gumboro (Group II; 1585-1620 g). Thus, there is a significant variation in body weight of Gumboro affected broilers due to existing and imposed vaccination program.…”