Staphylococcal mastitis is a major health problem in humans and livestock that leads to economic loss running in millions. This process is currently one of the main reasons for culling adult rabbit does. Surprisingly, the two most prevalent S. aureus lineages isolated from non-differentiable natural clinical mastitis in rabbits (ST121 and ST96) generate different immune responses. This study aimed to genetically compare both types of strains to search for possible dissimilarities to explain differences in immune response, and to check whether they showed similar virulence in in vitro tests as in experimental intramammary in vivo infection. The main differences were observed in the enterotoxin gene cluster (egc) and the immune-evasion-cluster (IEC) genes. While isolate ST121 harboured all six egc cluster members (seg, sei, selm, seln, selo, selu), isolate ST96 lacked the egc cluster. Strain ST96 carried a phage integrase Sa3 (Sa3int), compatible with a phage integrated into the hlb gene (β-haemolysin-converting bacteriophages) with IEC type F, while isolate ST121 lacked IEC genes and the hlb gene was intact. Moreover, the in vitro tests confirmed a different virulence capacity between strains as ST121 showed greater cytotoxicity for erythrocytes, polymorphonuclear leukocytes and macrophages than strain ST96. Differences were also found 7 days after experimental intramammary infection with 100 colony-forming units. The animals inoculated with strain ST121 developed more severe gross and histological mastitis, higher counts of macrophages in tissue and of all the cell populations in peripheral blood, and a significantly larger total number of bacteria than those infected by strain ST96.
The aim of this study was to determine how genetic type could affect the physiological 14 and immune status of commercial rabbits at weaning, as well as their performance and 15 health during the growing period. The study was conducted on a total of 2904 young 16 rabbits weaned at 30 days, belonging to three different genetic types (line H, founded for 17 litter size at birth and selected for litter size at weaning during 17 generations; line LP, 18 founded for reproductive longevity criteria and selected for litter size at weaning for 7 19 generations; and line R, founded and selected during 25 generations for average daily 20 gain from the 4 th to the 9 th week of life). Two different diets were used during lactation. 21The two diets were both isoenergetic and isoproteic but their main energy source differed, 22 being either animal fat (AF) or cereal starch (CS). Leukocyte subsets were characterised 23 at weaning, and growing performance was studied until 58 days of age (feed intake, live 24 weight, mortality by digestive disorders and morbidity) for both medicated and non-25 medicated dietary versions. At weaning, young rabbits fed an AF lactating diet evidenced 26 greater B lymphocyte count (+ 46%) than those fed a CS diet. Blood from LP rabbits had 27 higher counts for total B, T CD5 + and CD8 + lymphocytes with respect to H and R (on av. 28 +40, +57, +28, and +27%, respectively; P<0.05), and CD4 + lymphocytes, monocytes and 29 granulocytes with respect to R (on av. +24, +32 and +44%, respectively; P<0.05) at 30 weaning. LP line rabbits also showed lower mortality by digestive disorders (on av. −8 31 points of percentage) and morbidity (on av. −4 points) than those from H and R lines 32 during the growing period (P<0.05). R animals presented higher feed intake and daily 33 weight gain, and a lower feed conversion ratio than H and LP animals (on av. +16.7±2.7 34 g dry matter/day, +10.3±0.4 g/day and −0.22±0.04 g dry matter/g, respectively). In 35 conclusion, the foundation of a line for reproductive longevity, which has been previously 36 reported to give greater robustness (low environmental sensitivity) to their reproductive 37 3 stock, could have also conferred a greater immunological development at weaning to their 38 offspring, as well as a better ability to confront digestive disorders as compared to other 39 lines founded or selected exclusively for productive criteria. 40
Three successive umbilical cord accidents (UCAs) were diagnosed in the same female bottlenose dolphin Tursiops truncatus during consecutive gestations. In 2 of these, transabdominal ultrasonographic examination revealed coiling of the UC around the peduncle of the foetus. All 3 foetuses were male, died in utero during the last third of gestation and were spontaneously aborted. The 3 UCs were elongated, flattened and congested. For 3 subsequent pregnancies, a different sire was used for mating, handling protocols and treatments were adjusted, and 3 live female calves were successfully delivered. UC lengths were normal. UCAs are associated with excessively long UCs and are not uncommon in humans and horses but are unusual in other species. We believe this is the first detailed report of recurrent UCAs in a dolphin.
We have assessed the spectral transmittance of the different layers of the human cornea in the ultraviolet (UV), visible, and near-infrared (IR) spectral ranges. Seventy-four corneal sample donors were included in the study. Firstly, the corneal transmittance was measured using a spectrophotometer. Then, all samples were fixed for histopathological analysis, which allowed us to measure the thickness of each corneal layer. Finally, the absorption coefficients of the corneal layers were computed by a linear model reproducing total transmittance. The results show that corneal transmission was almost in unity at the visible and IR ranges but not at the UV range, in which the layer with higher transmission is Descemet’s membrane, whereas the stroma showed the lowest transmittance. Regarding the absorption coefficient, the most absorptive tissue was Bowman’s layer, followed by the endothelium. Variations on transmittance due to changes in the stroma, Bowman’s layer, or Descemet layer were simulated, and important transmission increases were found due to stroma and Bowman changes. To conclude, we have developed a method to measure the transmittance and thickness for each corneal layer. All corneal layers absorb UV light to a greater or lesser extent. The absorption coefficient is higher for Bowman’s layer, while the stroma is the layer with the lowest transmittance due to its thickness. Variations in stroma thickness or changes in the corneal tissue of Bowman’s layer or the endothelium layer due to some pathologies or surgeries could affect, to a greater or lesser degree, the total transmission of the cornea. Thus, obtaining accurate absorption coefficients for different layers would help us to predict and compensate these changes.
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