Project description:The study reports a differential proteomic analysis of the Mediterranean buffalo milk to evaluate the changes induced by Staphylococcus spp. during a subclinical intramammary infection (IMI). A number of 12 quarter milk samples, 6 of which with somatic cell count (SCC) < 50,000 cells/mL and culture-negative, and the other 6 with SCC ˃ 3,000,000 cells/mL and culture-positive to Staphylococcus aureus (SAU, n=3), SAU, or non-aureus staphylococci (NAS, n=3) was selected. Samples were analyzed using a shotgun proteomics approach, based on filter-aided sample preparation (FASP) followed by LC-MS/MS and label-free analysis. Here, the largest buffalo milk protein dataset described so far was reported. Moreover, the results demonstrated that staphylococcal IMI mostly affected proteins involved in structural functions and in innate immune defense, with changes in their abundance that were generally more intense in SAU than in NAS samples. Further, an increase in the abundance of different cathelicidins was observed, as already reported for other animals with mastitis disease (1,2). (1) Addis MF, Pisanu S, Marogna G, Cubeddu T, Pagnozzi D, Cacciotto C, et al. Production and release of antimicrobial and immune defense proteins by mammary epithelial cells following Streptococcus uberis infection of sheep. Infect Immun. 2013;81: 3182–3197. (2) Addis MF, Tedde V, Dore S, Pisanu S, Puggioni GMG, Roggio AM, et al. Evaluation of milk cathelicidin for detection of dairy sheep mastitis. J Dairy Sci. Elsevier; 2016;99: 6446–6456. In conclusion, our results provide the first in depth characterization of buffalo milk proteins, describe the changes induced by SAU and NAS subclinical intramammary infection and suggest indications to reveal subclinical staphylococcal mastitis in buffalo by the milk proteome investigation.
Project description:The aim of this experiment was to understand the different transcriptomic profiles of Staphylococcus aureus strains when cultured in 50% milk media with TSB media as a control. Bovine S. aureus strains that are capable of clotting milk where compared to both bovine and human S. aureus strains unable to clot milk. All strains are from sequence type 97.
Project description:To determine if significant genomic changes are associated with the development of vancomycin intermediate Staphylococcus aureus, genomic DNA microarrays were performed to compare the initial vancomycin susceptible Staphylococcus aureus (VSSA) and a related vancomycin intermediate Staphylococcus aureus (VISA) isolate from five unique patients (five isolate pairs). Keywords: comparative genomic hybridization
Project description:Milk is an essential source of nutrients to all mammalian offspring, and is rich in a wide variety of immunological components. Recently reported miRNAs that are present in breast milk and are selectively packaged into the exosomes, a type of membrane vesicles, secreted by most cell types. These exosomal miRNAs could be actively delivered into recipient cells, and play a key role in the regulation of innate and adaptive immunity. In the present study we analyzed the lactation-related miRNA expression profiles in bovine milk exosomes at 2 days post-infection with Staphylococcus aureus (S. aureus) using a deep sequencing. Analyzing over 76.44 million sequencing reads, a total of 720 miRNAs including 303 high-confident miRNA candidates were identified by two different approaches. The top 10 highly expressed miRNAs accounted for approximately 80% of all aligned reads, with the remaining miRNAs showing much lower expression. Bta-miR-101, -142-5p, -183, -2285g-3p, -223 and -99a-5p were significantly differentially regulated in S. aureus infected milk compared to their uninfected controls. Target prediction of the differently expressed miRNAs revealed 219 potential target candidates, and 22 unique target genes identified by David Gene Ontology analysis were significantly related to host immune processes and inflammation. This new knowledge of milk miRNA expression in response to S. aureus infection significantly provides new and comprehensive information on milk miRNA composition in general as well as changes occurring during an infection.
Project description:Staphylococci are major pathogens in humans and animals and emerging antibiotic-resistant strains have further increased the importance of this health issue. The existence of a genetic basis of host response to bacterial infections has been widely documented but the underlying mechanisms and genes are still largely unknown. Previously, two divergent lines of sheep selected on their milk somatic cell count called high and low SCS lines, have been showed to be respectively more and less susceptible to intra mammary infections (IMI). Transcriptional profiling of milk somatic cells (MSC) of high and low SCS sheep infected successively by S. epidermidis and S. aureus was performed to provide enhanced knowledge about the genetic basis of differential host response to IMI with Staphylococci. Gene expression in MSC of high and low SCS sheep collected 12h post-challenge was performed on a 15K gene ovine oligoarray (Agilent). MSC were mainly neutrophils. The high number of differentially expressed genes between the two bacterial strains indicated, among others, increased number of T-cells in MSC after S. aureus, compared to S. epidermidis challenge. Differential regulation of 366 genes between resistant and susceptible animals was largely associated with immune and inflammatory response (including pathogen recognition TLR2 pathway and cell migration), signal transduction, cell proliferation and apoptosis. Close biological connection between most of differentially expressed genes into Ingenuity Pathway Analysis networks further indicated consistency between the genes that were differentially-expressed between resistant and susceptible animals. Gene profiling in high and low SCS sheep provided strong candidates for biological pathway and gene underlying genetically determined resistance and susceptibility towards Staphylococci infections opening new fields for further investigation. Keywords: Staphylococcus epidermidis, Staphylococcus aureus, milk somatic cells, mammalian, transcriptome, immunity, mastitis 22 samples in a two-colour dye-swap experimental design
Project description:Staphylococci are major pathogens in humans and animals and emerging antibiotic-resistant strains have further increased the importance of this health issue. The existence of a genetic basis of host response to bacterial infections has been widely documented but the underlying mechanisms and genes are still largely unknown. Previously, two divergent lines of sheep selected on their milk somatic cell count called high and low SCS lines, have been showed to be respectively more and less susceptible to intra mammary infections (IMI). Transcriptional profiling of milk somatic cells (MSC) of high and low SCS sheep infected successively by S. epidermidis and S. aureus was performed to provide enhanced knowledge about the genetic basis of differential host response to IMI with Staphylococci. Gene expression in MSC of high and low SCS sheep collected 12h post-challenge was performed on a 15K gene ovine oligoarray (Agilent). MSC were mainly neutrophils. The high number of differentially expressed genes between the two bacterial strains indicated, among others, increased number of T-cells in MSC after S. aureus, compared to S. epidermidis challenge. Differential regulation of 366 genes between resistant and susceptible animals was largely associated with immune and inflammatory response (including pathogen recognition TLR2 pathway and cell migration), signal transduction, cell proliferation and apoptosis. Close biological connection between most of differentially expressed genes into Ingenuity Pathway Analysis networks further indicated consistency between the genes that were differentially-expressed between resistant and susceptible animals. Gene profiling in high and low SCS sheep provided strong candidates for biological pathway and gene underlying genetically determined resistance and susceptibility towards Staphylococci infections opening new fields for further investigation. Keywords: Staphylococcus epidermidis, Staphylococcus aureus, milk somatic cells, mammalian, transcriptome, immunity, mastitis
Project description:Bovine mastitis, predominantly caused by pathogenic Staphylococcus aureus, is a major impediment to milk production. Although its prevalence varies from cows to buffaloes, it lacks relevant markers that mark the phases and progression of the disease. Thus, the focus of this study was to identify key proteins that mark the transition from subclinical to clinical states in a species specific manner. Whey proteins isolated from healthy and S. aureus infected milk from both Holstein Friesian cow and Murrah buffalo were characterized by label free quantification using mass spectrometry. Collectively, 662 proteins were identified with atleast two peptides, of which 51 and 80 proteins were found significant by ANOVA (p value < 0.05) with increasing or decreasing trends in the disease progression in HF and Mu, respectively. Linear change in expression of proteins like haptoglobin and fibronectin in HF and spermadhesin and osteopontin in Mu correlated with the stage of the disease and progression in a species specific manner. Similarly, high mobility group proteins, angiogenin, cofilin-1 that were previously reported in oxidative stress were overexpressed whilemembers of ubiquitin family which remove aggregated proteins were downregulated during the progression of infection. Subsequently, selected differentially expressed proteins (e.g. osteopontin, CAP-1 and fibrinogen α) were validated by Western blot analysis. Results of this study provide deeper insights on whey proteome dynamics and a signature pattern indicative of disease progression.
Project description:Staphylococcus aureus is one of the most important pathogens in humans and animals, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Rhein, a natural plant product, has potential antimicrobial activity against Staphylococcus aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with rhein. Results provided insight into mechanisms involved in rhein - Staphylococcus aureus interactions. Keywords: rhein response
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. magnolol has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with magnolol. Keywords: gene expression array-based, count
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Cryptotanshinone, a natural plant product, has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with cryptotanshinone. Keywords: gene expression array-based, count