Phage therapy combined with Gum Karaya injectable hydrogels for treatment of methicillin-resistant Staphylococcus aureus deep wound infection in a porcine model.

Skin and soft tissue infections (SSTIs) represent a significant healthcare challenge, particularly in the context of increasing antibiotic resistance. This study investigates the efficacy of a novel therapeutic approach combining bacteriophage (phage) therapy with a gum Karaya (GK)-based hydrogel delivery system in a porcine model of deep staphylococcal SSTIs. The study exploits the lytic activity and safety of the Staphylococcus phage 812K1/420 of the Kayvirus genus, which is active against methicillin-resistant Staphylococcus aureus (MRSA). The GK injectable hydrogels and hydrogel films, developed by our research group, serve as effective, non-toxic, and easy-to-apply delivery systems, supporting moist wound healing and re-epithelialization. In the porcine model, the combined treatment showed asynergistic effect, leading to a significant reduction in bacterial load (2.5 log CFU/gram of tissue) within one week. Local signs of inflammation were significantly reduced by day 8, with clear evidence of re-epithelialization and wound contraction. Importantly, no adverse effects of the GK-based delivery system were observed throughout the study. The results highlight the potential of this innovative therapeutic approach to effectively treat deep staphylococcal SSTIs, providing a promising avenue for further research and clinical application in the field of infections caused by antibiotic-resistant bacteria.

Experimental oral and ocular Encephalitozoon cuniculi infection in rabbits.

Encephalitozoon cuniculi is an obligate intracellular pathogen that has a wide host distribution, but primarily affects rabbits. The aim of this study was to characterize both the cell-mediated and the antibody response in rabbits after experimental infection using 2 different infection routes: oral and ocular. SPF rabbits were infected with low (10³ spores) and high (107 spores) infection doses. Monitored parameters included clinical signs, detection of spores in urine, antibody response detected with ELISA, and cell-mediated immunity detected by antigen-driven lymphocyte proliferation. At week 13 post-infection, half of the rabbits in each group were suppressed by intramuscular administration of dexamethasone. At week 18 post-infection, animals were euthanized. Clinical signs were mild with exacerbation after immunosuppression. Spores in urine and antigen-specific cell-mediated immunity were detected from weeks 5 and 4 post-infection, respectively. Specific IgM was detected 1 week after infection, and IgG antibodies followed 1 week later in rabbits infected with the high dose. Immunological responses were dose dependent. The authors can conclude that both oral and ocular experimental infection with E. cuniculi resulted in an immune response of the infected animals. Rabbits could be used as an experimental model for the study of ocular microsporidiosis.

Age-related changes in selected haematology parameters in rabbits.

Even though there is an abundance of information on the reference values of haematological parameters in adult rabbits, a little is known about the changes in haematology in newborn rabbits or during their postnatal development. Therefore, the aim of our study was to investigate changes in red blood cells (RBC), white blood cells (WBC) and differential leukocyte counts in SPF New Zealand White rabbits from the age of one day to 20 weeks. Significant age-related changes during the first four weeks of life were detected. These included an increase of RBC and WBC, reversal of the neutrophil/lymphocyte ratio and increase of total counts of eosinophils and basophils. From the age of six weeks of life, all of the studied haematological parameters were comparable to those of adult rabbits.

Diseases in pet guinea pigs: a retrospective study in 1000 animals.

Guinea pigs are commonly kept as pet animals; however, information about particular disease prevalence is lacking. The objective of this article was to present disease prevalence in 1000 pet guinea pigs from private owners divided into three age groups: under two years; between two and five years; and above five years. Medical records of guinea pigs (Cavia aperea f. porcellus) that were presented to the authors' clinic in the period from January 2008 to August 2013 were reviewed. The most commonly diagnosed disease in guinea pigs was dental disease (36.3 per cent), with higher prevalence in the middle age group (P<0.001) and in males (P<0.001) rather than females. Skin problems were seen as the second most common disease (33.3 per cent), with higher prevalence in male guinea pigs (P<0.001) and in animals younger than two years (P<0.001). Ovarian cystic disease was the third most commonly seen disorder, with higher prevalence in females older than two years (P<0.001). Other common health disorders included gastrointestinal stasis, heterotopic ciliary body calcifications, fatty eye and tibiofemoral osteoarthritis. Only 81 guinea pigs from a total of 1000 animals were healthy. This is the first study to describe the disease prevalence in three age groups of pet guinea pigs.

Impact of a high-phosphorus diet on the sonographic and CT appearance of kidneys in degus, and possible concurrence with dental problems.

The main aim of this study was to investigate the impact of pelleted diet of different mineral composition on the sonographic and CT appearance of kidneys in degus (Octodon degus). A total of 35 animals were randomly divided into five groups, fed diets containing different calcium and phosphorus contents (13.5 g/kg calcium and 6.3 g/kg phosphorus, or 9.1 g/kg calcium and 9.5 g/kg phosphorus) and given different amounts of exposure to UV light. Endoscopic examination of the oral cavity as well as renal ultrasonography and CT was performed four times at four-month intervals throughout the study. After 14 months of feeding an experimental diet, all degus were euthanased and subsequently all kidneys were collected for histopathological examination. Animals fed a diet with high dietary phosphate and improper calcium to phosphorus ratio showed severe nephrocalcinosis. Ultrasonographic and CT kidney abnormalities presented as hyperechogenicity and hyperdensity (interpreted as nephrocalcinosis), respectively. The most striking changes were seen at the corticomedullary zone. Ultrasonography and CT correlated in all cases with histopathological findings. Dental disease developed quickly in groups fed diets with an improper calcium and phosphorus content, with obvious apical and coronal elongation of all the teeth. A possible influence of UV light access could not be proved in this study.

Selected haematological and plasma chemistry parameters in juvenile and adult degus (Octodon degus).

Thirty-five juvenile (mean age 6.3 weeks) and 35 adult (mean age 2.0 years) healthy degus (Octodon degus) were studied to investigate selected haematological and plasma biochemistry parameters. Animals were anaesthetised with isoflurane, and blood was withdrawn from the cranial vena cava. Erythrocyte, haematocrit and neutrophil counts (including the percentage of neutrophils) were significantly higher in the adult degus than in the juveniles. In contrast, the reticulocyte count, mean corpuscular volume, mean corpuscular haemoglobin, number of platelets and percentage of lymphocytes were significantly lower in the adult animals. Total protein and globulin levels were significantly higher in the adult degus. The albumin:globulin ratio and plasma levels of urea nitrogen, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, potassium, total calcium and inorganic phosphorus were significantly lower in adults than in juveniles.

Impact of pelleted diets with different mineral compositions on the crown size of mandibular cheek teeth and mandibular relative density in degus (Octodon degus).

The impact of pelleted diets with different mineral compositions on the crown size of the mandibular cheek teeth, as well as the mandibular bone and cheek teeth density, in degus (Octodon degus) was investigated. A total of 28 animals were randomly divided into four groups and fed different calcium or phosphorous dietary content, in the presence or absence of UV light, for 14 months. Dental radiographs and CT images of the head were taken, and the crown size of premolar and molar teeth was recorded. Apical and coronal crown elongation of all cheek teeth and significantly smaller relative cheek teeth and mandibular densities were recorded in degus fed a high-phosphorus diet with an improper calcium:phosphorus ratio. A diet with a calcium:phosphorus ratio of 1:1 was also responsible for the rapid development of dental disease with subsequent severe health impairment.