Phenotypic characteristics and comparative proteomics of Staphylococcus aureus strains with different vancomycin-resistance levels

Proteomic Analysis of Staphylococcus aureus Treated with ShangKeHuangShui

Staphylococcus aureus (SAU) stands as the prevailing pathogen in post-traumatic infections, with the emergence of antibiotic resistance presenting formidable treatment hurdles. The pressing need is to explore novel antibiotics to address this challenge. ShangKeHuangShui (SKHS), a patented traditional Chinese herbal formula, has gained widespread use in averting post-traumatic infections, but its biological effects remain incomplete understanding. This study's primary objective was to delve into the antibacterial properties, potential antibacterial compounds within SKHS, and their associated molecular targets. In vitro SKHS antibacterial assays demonstrated that the minimum inhibitory concentration (MIC) was 8.625 mg/mL and the minimum bactericide concentration (MBC) was 17.25 mg/mL. Proteomic analysis based on tandem mass tag (TMT) showed significant changes in the expression level of 246 proteins in SKHS treated group compared to control group, with 79 proteins upregulated and 167 proteins downregulated (>1.5-fold, p < 0.05). Subsequently, thirteen target proteins related to various biological processes and multiple metabolic pathways were selected to conduct parallel reaction monitoring (PRM) and molecular docking screen. In protein tyrosine phosphatase PtpA (ptpA) docking screening, phellodendrine and obacunone can bind to ptpA with the binding energy of - 8.4 and - 8.3 kcal/mol, respectively. This suggests their potential impact on antibacterial activity by modulating the two-component system of SAU. The discovery lays a groundwork for future research endeavors for exploring new antibacterial candidates and elucidating specific active chemical components within SKHS that match target proteins. Further investigations are imperative to unveil the biological effects of these monomers and their potential synergistic actions.

Proteomic Profiles and Protein Network Analysis of Primary Human Leukocytes Revealed Possible Clearance Biomarkers for Staphylococcus aureus Infection

Staphylococcus aureus is a serious pathogen that can survive within host cells after a typical course of treatment completion, leading to chronic infection. Knowledge of host proteomic patterns after clearance of this pathogen from cells is limited. Here, we looked for S. aureus clearance biomarkers produced by in vitro-infected leukocytes. Extracellular proteins from primary human leukocytes infected with S. aureus ATCC 25923 were investigated as possible treatment-monitoring clearance biomarkers by applying a proteomics approach combining liquid chromatography with tandem mass spectrometry (LC-MS/MS) and protein interaction network analysis. It was found that the expression patterns of proteins secreted by S. aureus-infected leukocytes differed among stages of infection. Proteomic profiles showed that an ATPase, aminophospholipid transporter-like, Class I, type 8A, member 2 (ATP8A2) was expressed in the clearance stage and was not detected at any earlier stage or in uninfected controls. Protein network analysis showed that TERF2 (telomeric repeat-binding factor 2), ZNF440 (zinc finger protein 440), and PPP1R14A (phosphatase 1 regulatory subunit 14A) were up-regulated, while GLE1, an essential RNA-export mediator, was suppressed in both infection and clearance stages, suggesting their potential roles in S. aureus infection and clearance. These findings are the first to report that the ATP8A2 has potential as a clearance biomarker for S. aureus infection.

The Cell Wall, Cell Membrane and Virulence Factors of Staphylococcus aureus and Their Role in Antibiotic Resistance

Antibiotic resistant strains of bacteria are a serious threat to human health. With increasing antibiotic resistance in common human pathogens, fewer antibiotics remain effective against infectious diseases. Staphylococcus aureus is a pathogenic bacterium of particular concern to human health as it has developed resistance to many of the currently used antibiotics leaving very few remaining as effective treatment. Alternatives to conventional antibiotics are needed for treating resistant bacterial infections. A deeper understanding of the cellular characteristics of resistant bacteria beyond well characterized resistance mechanisms can allow for increased ability to properly treat them and to potentially identify targetable changes. This review looks at antibiotic resistance in S aureus in relation to its cellular components, the cell wall, cell membrane and virulence factors. Methicillin resistant S aureus bacteria are resistant to most antibiotics and some strains have even developed resistance to the last resort antibiotics vancomycin and daptomycin. Modifications in cell wall peptidoglycan and teichoic acids are noted in antibiotic resistant bacteria. Alterations in cell membrane lipids affect susceptibility to antibiotics through surface charge, permeability, fluidity, and stability of the bacterial membrane. Virulence factors such as adhesins, toxins and immunomodulators serve versatile pathogenic functions in S aureus. New antimicrobial strategies can target cell membrane lipids and virulence factors including anti-virulence treatment as an adjuvant to traditional antibiotic therapy.

Monitoring of distribution of antibiotic-resistant strains of microorganisms in patients with dysbiosis of the urogenital tract

Currently, the problem of the development of resistance to drugs among microorganisms that colonize the urogenital system is becoming especially relevant due to broadly distributed dysbiotic conditions of the reproductive system of men and women. Therefore, there should be constant monitoring of the qualitative and quantitative composition of microbiota of the urogential tract and determination of the levels of antibiotic-resistance of strains of conditionally pathogenic microorganisms in the reproductive system of various layers of the population. We monitored 774,375 people of various age and sex – patients of the independent diagnostic laboratory INVITRO in the city Dnipro in 2017–2019. Among the examined people, 640,783 of the patients were diagnosed with the development of dysbiotic disorders, accounting for 82.7% of the total amount of the applications for medical help. According to the results of identification of the range of dysbiotic conditions of the urogenital system of patients of different ages and sexes, we determined the dominating role of facultative anaerobes in the development of dysbiotic impairments caused by colonizations by large numbers of conditionally-pathogenic microorganisms: in women, Gardnerella accounted for 86.1%, Staphylococcus – 63.2%, Streptococcus – 54.1%, Candida – 69.3%; in men, Streptococcus were found in 83.0%, Staphylococcus – 79.4%, Corynebacterium – 54.2% and Candida – 37.6% of the cases. Share of obligate anaerobes was also quite large: women were diagnosed with Prevotella in 59.7%, Peptostreptococcus in 53.2%, Fusobacterium in 45.4% of the cases cases; men were observed to have Peptostreptococcus 62.4%, Clostridium in 54.3%, Bacteroides in 32.5% of the cases. We determined high parameters of frequency of diagnosing antibiotic-resistant isolates of conditionally pathogenic microorganisms that circulate in the urogenital tract of patients with dysbiotic impairments, belonging to the following families: Mycoplasmataceae – 78.6%, Enterobacteriaceae – 56.0% and genera – Staphylococcus – 76.1%, Gardnerella – 24.3%, Corynebacterium – 21.2%. The research revealed increase in the frequency of detection of strains of urapathogenic bacteria resistant to the applied antibiotic preparations in 2018–2019 compared with the data of 2017: increases of 10.3% and 6.4% in representatives of family Mycoplasmataceae resistant to ciprofloxacin and ofloxacin respectively, 4.8% and 4.0% in Enterobacteriaceae resistant to chloramphenicol and ampicillin respectively, and 8.9% in the genus Staphylococcus resistant to vancomycin.

iTRAQ®-based quantitative proteomics reveals the proteomic profiling of methicillin-resistant Staphylococcus aureus-derived extracellular vesicles after exposure to imipenem

This study sought to reveal the proteomic profiling of methicillin-resistant Staphylococcus aureus (MRSA)-derived extracellular vesicles (EVs) after exposure to imipenem. The advanced isobaric tags for relative and absolute quantitation (iTRAQ®) proteomic approach were used to analyze the alterations in MRSA-derived EV protein patterns upon exposure to imipenem. A total of 1260 EV proteins were identified and quantified. Among these, 861 differentially expressed exosome proteins (P < 0.05) were found. Multivariate analysis, Gene Ontology (GO) annotation, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to analyze the identified proteins. Enrichment analysis of GO annotations indicated that imipenem primarily regulated the metabolic processes in MRSA. The metabolism of differentially expressed proteins was found to be the most significant in the combined analysis of the KEGG pathway analysis. Based on the results from the STRING analysis, 50S ribosomal protein L16 (RplP) and 30S ribosomal protein S8 (RpsH) were involved in the imipenem-induced MRSA-derived EVs. These results provide vital information on MRSA-derived EVs, increasing our knowledge of the proteome level changes in EVs upon exposure to imipenem. Moreover, these results pave the way for developing novel MRSA treatments.