ABSTRACT: The molecular epidemiology and antimicrobial resistance of Staphylococcus Pseudintermedius canine clinical isolates submitted to a veterinary diagnostic laboratory in South Africa.
Project description:Mesenchymal Stromal Cells (MSCs) are widely studied in regenerative medicine because of their unique biological properties. The MSC-derived secretome is a cell-free product containing soluble factors and extracellular vesicles that mediate many of the biological properties of MSCs, including immunomodulatory and antimicrobial activities. This study aimed to evaluate the antimicrobial activity of a freeze-dried secretome derived from canine adipose tissue MSCs (canine lyosecretome, c-Lyo) against pathogens relevant to canine infections. The antimicrobial activity of c-Lyo was assessed using minimal inhibitory concentration (MIC) assays against six bacterial species (Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus pseudintermedius and Pseudomonas aeruginosa) and one yeast (Malassezia pachydermatis). Potential interactions between c-Lyo and commonly used veterinary antimicrobials (gentamicin, amoxicillin, enrofloxacin, and ketoconazole) were evaluated using checkerboard assays (CkA). Proteomic characterization of the c-Lyo and transcriptomic analysis of canine MSCs were also conducted to explore molecular mechanisms underlying antimicrobial activity. The results demonstrated that c-Lyo exerts antimicrobial activity against all tested microorganisms, with variable sensitivity among species. CkA exhibited predominantly additive interactions with conventional antimicrobials and occasional synergistic effects, with no evidence of antagonism. Proteomic and transcriptomic analyses supported the presence of antimicrobial peptides and immune-related pathways that potentially contribute to both direct antimicrobial activity and the modulation of host defense mechanisms. These findings indicate that c-Lyo may represent a promising cell-free biologic approach for antimicrobial strategies in veterinary medicine.
Project description:This project applies SWATH approach to analyse ex-diagnostic sheep serum samples from actual clinical cases submitted to The University of Queensland's School of Veterinary Science, Veterinary Laboratory Services (VLS) compared with serum of normal sheep.
Project description:We previously showed that doxycycline and carprofen , a veterinary non-steroidal anti-inflammatory drug, have synergistic antimicrobial activity against methicillin-resistant Staphylococus pseudintermedius (MRSP) carrying the tetracycline resistance determinant TetK. To elucidate the molecular mechanism of this synergy, we investigated the effects of the two drugs, individually and in combination, using a comprehensive approach including two-dimensional differential in-gel electrophoresis (2D DIGE).
Project description:This study aims to determine the epidemiology of Enterobacteriaceae resistant to antibiotics of last resort in pregnant women in labour at a tertiary hospital, Pretoria, South Africa. Rectal swabs shall be used to screen for colonisation with CRE and colistin-resistant Enterobacteriales in pregnant women during labour. Carbapenem and colistin-resistant Enterobacterales can cause the following infections: bacteraemia; nosocomial pneumonia; urinary tract infections, and intra-abdominal infections. Due to limited treatment options, infections caused by these multidrug-resistant organisms are associated with a mortality rate of 40-50%. Screening for colonisation of carbapenem-resistant Enterobacteriaceae (CRE) and colistin-resistant Enterobacteriaceae will help implement infection and prevention measures to limit the spread of these multidrug-resistant organisms.
Project description:The emergence and fast global spread of COVID-19 has presented one of the greatest public health challenges in modern times with no proven cure or vaccine. Africa is still early in this epidemic, therefore the extent of disease severity is not yet clear. We used a mathematical model to fit to the observed cases of COVID-19 in South Africa to estimate the basic reproductive number and critical vaccination coverage to control the disease for different hypothetical vaccine efficacy scenarios. We also estimated the percentage reduction in effective contacts due to the social distancing measures implemented. Early model estimates show that COVID-19 outbreak in South Africa had a basic reproductive number of 2.95 (95% credible interval [CrI] 2.83–3.33). A vaccine with 70% efficacy had the capacity to contain COVID-19 outbreak but at very higher vaccination coverage 94.44% (95% Crl 92.44–99.92%) with a vaccine of 100% efficacy requiring 66.10% (95% Crl 64.72–69.95%) coverage. Social distancing measures put in place have so far reduced the number of social contacts by 80.31% (95% Crl 79.76–80.85%). These findings suggest that a highly efficacious vaccine would have been required to contain COVID-19 in South Africa. Therefore, the current social distancing measures to reduce contacts will remain key in controlling the infection in the absence of vaccines and other therapeutics.
2024-09-02 | BIOMD0000000978 | BioModels
Project description:Molecular epidemiology of Klebsiella pneumoniae isolates causing invasive disease from a private laboratory in South Africa
Project description:We performed a veterinary clinical oncology trial in client-owned dogs to determine if immune modulating drugs could be combined in rational approaches to treat spontaneous canine diffuse large B cell lymphoma (DLBCL).
