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Borrelia persica, a bacterium transmitted by the soft tick Ornithodoros tholozani, causes tick-borne relapsing fever in humans in the Middle East, Central Asia and the Indian peninsula. Immunocompetent C3H/HeOuJ mice were infected intradermally with B. persica at varying doses: 1 x 106, 1 x 104, 1 x 102 and 4 x 100 spirochetes/mouse. Subsequently, blood samples were collected and screened for the presence of B. persica DNA. Spirochetes were detected in all mice infected with 1 x 106, 1 x 104 and 1 x 102 borrelia by real-time PCR targeting the flaB gene of the bacterium. Spirochetemia developed with a one- to two-day delay when 1 x 104 and 1 x 102 borrelia were inoculated. Mice injected with only four organisms were negative in all tests. No clinical signs were observed when infected mice were compared to negative control animals. Organs (heart, spleen, urinary bladder, tarsal joint, skin and brain) were tested for B. persica-specific DNA and cultured for the detection of viable spirochetes. Compiled data show that the target organs of B. persica infections are the brain and the skin. A newly developed serological two-tiered test system (ELISA and western blot) for the detection of murine IgM, IgG and IgA antibody titers against B. persica showed a vigorous antibody response of the mice during infection. In conclusion, the infection model described here for B. persica is a platform for in vivo studies to decipher the so far unexplored survival strategies of this Borrelia species. [ABSTRACT FROM AUTHOR]

The objective of the present study was to assess safety and immune responses in gilts after intradermal application of Porcilis® PRRS in two different application sites under field conditions. Forty-four gilts were allocated to one of three groups: Gilts of group 1 (n = 10) served as non-vaccinated controls, gilts of group 2 (n = 17) were vaccinated intradermally in the neck and gilts of group 3 (n = 17) received an intradermal vaccination in the perianal region. Clinical observations, local injection site reactions and histopathologic examination of the injection site were used for safety assessments. Frequency and degree of clinical signs were not significantly different between all three groups. Minor local reactions for both vaccination groups were observed; however, at 6, 7, 8, 9 and 15 days post-vaccination (dpv), the mean injection site reaction score was significantly lower in pigs vaccinated in the perianal region. In histopathologic examination, an extended inflammatory dimension was observed more frequently in pigs vaccinated in the neck. Blood samples were analyzed to quantify the post-vaccination humoral (ELISA and virus neutralization test) and cellular (IFN-γ ELISPOT) immune responses. PRRSV-specific antibodies were present in the serum of all vaccinated animals from 14 dpv onwards, whereas all control pigs remained negative throughout the study. Neutralizing antibody titers were significantly higher in pigs vaccinated in the perianal region at 28 dpv. At 14, 21 and 28 dpv, PRRSV-specific IFN-γ secreting cells were significantly increased in both vaccination groups compared to non-vaccinated gilts. Analysis of mean numbers of PRRSV-specific IFN-γ secreting cells did not result in statistically significant differences between both vaccination groups. The results of this study indicate that the perianal region is a safe alternative application site for intradermal vaccination of gilts with Porcilis PRRS. Furthermore, the intradermal application of Porcilis PRRS induced humoral and cellular immune responses independent of the administration site. [ABSTRACT FROM AUTHOR]

Summary Growth hormone has been shown to possess stimulatory effects on various connective tissues. We observed that skin growth in male rat phosphoenolpyruvate carboxykinase-bovine growth hormone transgenic mice (serum growth hormone levels: 740–1940 ng per ml) is progressive with age, resulting in an ‘‘oversized coat’’ phenotype with a marked increase in absolute and relative skin weight and surface area, and in thickness of the dermis. Histologic changes include severe dermal fibrosis and replacement of subdermal adipose tissue by fibrous tissue. Apart from an increase in skin surface area, these changes were not noted in female transgenic mice, arguing for a specific interaction of growth hormone with male sex hormones. To clarify this point, 6 wk old male transgenic mice and control mice were castrated and compared with their noncastrated counterparts in parameters of skin growth at an age of 8 mo. The skin weight of castrated transgenic mice was smaller (p < 0.01) than that of intact transgenic mice both absolutely and relative to body weight. The relative skin weight of castrated transgenic mice was in the same range as in intact and castrated control mice. Absolute and relative skin area of castrated transgenic mice was greater (p < 0.001 and p < 0.05) than in controls but lower than in intact transgenic mice (p < 0.001 and p < 0.05). When compared with control mice, intact transgenic mice displayed an increase (p < 0.01) in the thickness of dermis. In castrated transgenic mice the thickness of the dermis was in the same range as in control mice. Our findings demonstrate a specific interaction of growth hormone with male sex hormones resulting in a marked stimulation of skin growth. [ABSTRACT FROM AUTHOR]