Since this study was designed to investigate the capacity of different vaccine strains to neutralize field isolates from Swedish pet cats, it is not possible to draw any conclusions about the connection between clinical indications and disease neutralization based on the clinical information stated from the veterinary clinicians at submission of samples

Since this study was designed to investigate the capacity of different vaccine strains to neutralize field isolates from Swedish pet cats, it is not possible to draw any conclusions about the connection between clinical indications and disease neutralization based on the clinical information stated from the veterinary clinicians at submission of samples. Conclusions This study confirms previous observations that antibodies raised against more recently introduced vaccine FCV strains, or vaccine strains used less widely, cross neutralize a higher proportion of circulating field isolates than antibodies raised against strains that have been used in vaccines extensively for a long time. G1 and 431). Results The anti-sera raised against F9 and 255 neutralised 20.5 and 11.5?%, and 47.4 and 64.1?% JNJ-5207852 of field isolates tested, respectively. The anti-sera against the more recently launched vaccine strains G1 and 431 neutralized 33.3 and 70.5?% and 69.2 and 89.7?%, respectively. Dual vaccine strains displayed a higher cross-neutralization. Conclusions This study confirms earlier observations that more recently launched vaccine strains induce antibodies with a higher neutralizing capacity compared to vaccine strains that have been used extensively over a long period of time. This study also suggests that dual FCV vaccine strains might neutralize more field isolates compared to solitary vaccine strains. Vaccine strains should ideally be selected based on updated knowledge within the antigenic properties of field isolates in the local setting, and there is thus a need for continuously studying the development of FCV together with the neutralizing capacity of vaccine strain induced antibodies against field isolates at a national and/or regional level. Electronic supplementary JNJ-5207852 material The online version of this article (doi:10.1186/s13028-015-0178-z) contains supplementary material, which is available to authorized users. strong class=”kwd-title” Keywords: Feline calicivirus, Vaccine, Disease neutralization, Feline top respiratory tract disease Background Feline calicivirus (FCV) is one of the primary causes of infectious upper respiratory tract disease in pet cats, an important disease worldwide [1]. In addition to respiratory indications, FCV is frequently associated with chronic gingivostomatitis, and highly virulent strains have been associated with an acute systemic virulent disease with a high case fatality rate [2, 3]. Feline calicivirus is definitely a single-stranded RNA-virus of positive sense genome with a high genetic and antigenic variability [4C6], associated with escape from your humoral immune response induced by natural illness and/or vaccination. FCV is definitely distributed world-wide in the cat population and is estimated to become the etiological cause of upper respiratory tract disease in 10C50?% of instances [1]. The prevalence of FCV varies depending on the management and quantity of pet cats in a household [7]. In multi-cat households, such as breeding catteries, cat shelters and cat colonies, FCV is definitely more prevalent [8, 9]. In Sweden, 18?% of feline medical samples submitted for disease isolation to the National Veterinary Institute during the yr 2000 tested positive for FCV, while healthy service providers of FCV in Swedish catteries were estimated at 2.6?% [10]. Several commercial vaccines consisting of numerous vaccine strains are available, but due to the high mutation rate of FCV, vaccines are not constantly efficacious [11C13]. There is consequently a need to investigate and adhere to the ability of vaccine strain induced antibodies to neutralize field isolates of FCV, in order to evaluate and provide updated suggestions on vaccination strategies at local and/or regional levels. In a earlier study, the cross-neutralization of FCV field strains isolated in the UK by vaccine strain induced antibodies JNJ-5207852 was examined [14]. Here, we used a similar approach to investigate whether JNJ-5207852 similar findings would apply inside a different Western country, namely Sweden. Methods FCV field isolates A panel of 78 field isolates of FCV cultivated in vitro was selected Rabbit Polyclonal to FRS3 from samples submitted between October 2008 and February 2012 to the National Veterinary Institute in Sweden. The samples were all collected from pet cats showing clinical indications compatible with FCV infection, even though clinical signs were not always expressed in the referral form (Additional file 1), and FCV analysis had been confirmed by transmission electron microscopy (TEM). Disease neutralization test The isolated FCV isolates were expanded following a inoculation of 2??105 cell/mL of feline embryo A (FEA) cells [15] in T25?cm2 flasks (Corning, NY). Cells were incubated at 37?C in an atmosphere of 5?% CO2. Ethnicities were observed for evidence of cytopathic effect (CPE) for up to 4?days post-infection. Once CPE became obvious, culture fluids were harvested, approved through a 0.45?m filter Minisart syringe filter (Sartorius, UK), aliquoted and stored at ?80?C prior to titration. To titrate the disease isolates, fourfold dilutions of the viral stocks (starting at a dilution of 1/500) were prepared and then incubated (in quadruplicate, per dilution per isolate) in 96-well.