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Revue Medicale Suisse Oct 2022Methicillin-susceptible staphylococcus aureus bacteremia is frequent and constantly increasing in Switzerland. It is associated with a high morbidity/mortality, despite...
Methicillin-susceptible staphylococcus aureus bacteremia is frequent and constantly increasing in Switzerland. It is associated with a high morbidity/mortality, despite antibiotic treatments. Through two clinical cases we discuss the epidemiology, pathophysiology, clinical presentation and treatment of this "disease", for which the history and clinical examination remain central in order to guarantee an optimal management.
Topics: Anti-Bacterial Agents; Bacteremia; Humans; Methicillin; Methicillin-Resistant Staphylococcus aureus; Staphylococcal Infections; Staphylococcus aureus
PubMed: 36226450
DOI: 10.53738/REVMED.2022.18.799.1889 -
Portuguese Journal of Cardiac Thoracic... Oct 2022A 59 year-old male presents with fever and left parasternal pain. Past medical history included arterial hypertension, dyslipidemia, smoking, obesity. His clinical exam...
A 59 year-old male presents with fever and left parasternal pain. Past medical history included arterial hypertension, dyslipidemia, smoking, obesity. His clinical exam was unremarkable. Both C-reactive protein and leucocytes were elevated. Chest computed tomography (CT) demonstrated a 18mm saccular pseudoaneurysm of the aortic arch with extensive adjacent densification and adenopathy (Figure 1 and 2). Methicillin-sensible Staphylococcus aureus was isolated from blood cultures. A transesophageal echocardiogram excluded endocarditis. Control Angio-CT after seven days showed a contained rupture and increase in diameter of the pseudoaneurysm. He underwent emergent surgery with circulatory arrest and anterograde cerebral perfusion; extensive resection of the pseudoaneurysmal aorta was performed, with reconstruction of the aortic arch using autologous pericardium, without implantation of foreign or synthetic material (Figure 3 and 4). He completed 4 weeks of Flucloxacillin IV, having been discharged under oral antibiotics.
Topics: Aneurysm, False; Aneurysm, Infected; Anti-Bacterial Agents; Aorta, Thoracic; C-Reactive Protein; Floxacillin; Humans; Male; Methicillin; Middle Aged
PubMed: 36197810
DOI: 10.48729/pjctvs.308 -
Veterinary Microbiology Jul 2014Staphylococcus pseudintermedius is a commensal and a common opportunistic pathogen causing mainly infections of the integumentary system in dogs. The recent emergence of... (Review)
Review
Staphylococcus pseudintermedius is a commensal and a common opportunistic pathogen causing mainly infections of the integumentary system in dogs. The recent emergence of multidrug-resistant S. pseudintermedius isolates, in particular methicillin-resistant strains (MRSP) is a threat to small animal health and highlights the need for antimicrobial resistance surveillance to detect trends and potentially perform timeous interventions. We systematically reviewed 202 published articles to investigate temporal changes in antimicrobial resistance in clinical and commensal S. pseudintermedius isolated from dogs in 27 countries between 1980 and 2013. Resistance to the most common antimicrobials tested for in published studies and important for the treatment of staphylococcal infections in dogs were assessed separately for methicillin resistant (MRSP) and methicillin susceptible (MSSP) isolates. Stratified by MSSP and MRSP, no significant increases in antimicrobial resistance were observed over time, except for the penicillinase-labile penicillins (penicillin and ampicillin) among MSSP. However, in recent years, a few studies have reported higher-level of resistance to amikacin, gentamicin and enrofloxacin amongst MSSP. The review highlights inconsistencies between studies as a result of several factors, for example the use of different antimicrobial susceptibility testing methods and interpretation criteria. We recommend that data on susceptibility in important companion animal pathogens are collected and presented in a more harmonized way to allow more precise comparison of susceptibility patterns between studies. One way to accomplish this would be through systematic surveillance either at the country-level or at a larger scale across countries e.g. EU level.
Topics: Animals; Anti-Bacterial Agents; Dog Diseases; Dogs; Male; Methicillin; Methicillin Resistance; Staphylococcal Infections; Staphylococcus
PubMed: 24613081
DOI: 10.1016/j.vetmic.2014.02.008 -
Revista Chilena de Infectologia :... 2018Staphylococcus aureus isolates resistant to several antimicrobials have been gradually emerged since the beginning of the antibiotic era. Consequently, the first... (Review)
Review
Staphylococcus aureus isolates resistant to several antimicrobials have been gradually emerged since the beginning of the antibiotic era. Consequently, the first isolation of methicillin-resistant S. aureus occurred in 1960, which was described a few years later in Chile. Currently, S. aureus resistant to antistaphylococcal penicillins is endemic in Chilean hospitals and worldwide, being responsible for a high burden of morbidity and mortality. This resistance is mediated by the expression of a new transpeptidase, named PBP2a or PBP2', which possesses lower affinity for the β-lactam antibiotics, allowing the synthesis of peptidoglycan even in presence of these antimicrobial agents. This new enzyme is encoded by the mecA gene, itself embedded in a chromosomal cassette displaying a genomic island structure, of which there are several types and subtypes. Methicillin resistance is mainly regulated by an induction mechanism activated in the presence of β-lactams, through a membrane receptor and a repressor of the gene expression. Although mec-independent methicillin resistance mechanisms have been described, they are clearly infrequent.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Chromosomes, Bacterial; Genes, Bacterial; Genetic Structures; Methicillin; Methicillin-Resistant Staphylococcus aureus; Molecular Structure; Penicillin-Binding Proteins
PubMed: 29652966
DOI: 10.4067/s0716-10182018000100007 -
Journal of Dairy Science Jun 2016Staphylococcus aureus is involved in a wide variety of diseases in humans and animals, and it is considered one of the most significant etiological agents of...
Staphylococcus aureus is involved in a wide variety of diseases in humans and animals, and it is considered one of the most significant etiological agents of intramammary infection in dairy ruminants, causing both clinical and subclinical infections. In this study, the intra-farm prevalence and circulation of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) were investigated on an Italian dairy sheep farm previously identified as MRSA-positive by testing bulk tank milk (first isolation in 2012). Human samples (nasal swabs, hand skin samples, and oropharyngeal swabs) from 3 persons working in close contact with the animals were also collected, and the genetic characteristics and relatedness of the MRSA isolates from human and animal sources within the farm were investigated. After 2yr from the first isolation, we confirmed the presence of the same multidrug-resistant strain of MRSA sequence type (ST)1, clonal complex (CC)1, spa type t127, staphylococcal cassette chromosome mec (SCCmec) type IVa, showing identical pulsed field gel electrophoresis (PFGE) and resistance profiles at the farm level in bulk tank milk. Methicillin-resistant S. aureus isolates were detected in 2 out of 556 (0.34%) individual milk samples, whereas MSSA isolates were detected in 10 samples (1.8%). The MRSA were further isolated from udder skin samples from the 2 animals that were MRSA-positive in milk and in 2 of the 3 examined farm personnel. All MRSA isolates from both ovine and human samples belonged to ST(CC)1, spa type t127, SCCmec type IVa, with some isolates from animals harboring genes considered markers of human adaptation. In contrast, all MSSA isolates belonged to ruminant-associated CC130, ST700, spa type t528. Analysis by PFGE performed on selected MRSA isolates of human and animal origin identified 2 closely related (96.3% similarity) pulsotypes, displaying only minimal differences in gene profiles (e.g., presence of the immune evasion cluster genes). Although we observed low MRSA intra-farm prevalence, our findings highlight the importance of considering the possible zoonotic potential of CC1 livestock-associated MRSA, in view of the ability to persist over years at the farm level. Biosecurity measures and good hygiene practices could be useful to prevent MRSA spread at the farm level and to minimize exposure in the community and in categories related to farm animal industry (e.g., veterinarians, farmers, and farm workers).
Topics: Animals; Anti-Bacterial Agents; Farms; Humans; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Sheep; Staphylococcal Infections; Staphylococcus aureus
PubMed: 27060817
DOI: 10.3168/jds.2016-10912 -
Antimicrobial Agents and Chemotherapy Dec 2023is the most prevalent cystic fibrosis (CF) pathogen. Several phenotypes are associated with worsened CF clinical outcomes including methicillin-resistance and...
is the most prevalent cystic fibrosis (CF) pathogen. Several phenotypes are associated with worsened CF clinical outcomes including methicillin-resistance and small-colony-variants. The inoculum effect (IE) is characterized by reduced β-lactam susceptibility when assessed at high inoculum. The IE associates with worse outcomes in bacteremia and other high-density infections, and may therefore be relevant to CF. The prevalence of IE amongst a CF cohort (age ≥18 years), followed from 2013 to 2016, was investigated. Yearly methicillin-sensitive (MSSA) isolates were screened at standard (5 × 10 CFU/mL) and high (5 × 10 CFU/mL) inoculum against narrow-spectrum anti-Staphylococcal β-lactams and those with anti-pseudomonal activity common to CF. A ≥ 4-fold increase in minimum inhibitory concentration between standard and high inoculum defined IE. Isolates underwent sequencing and genotyping and were compared against published genomes. Fifty-six percent (99/177) of individuals had MSSA infection. MSSA was observed at ≥10 CFU/mL in 44.8% of entry sputum samples. The prevalence of the IE was 25.0%-cefazolin; 13.5%-cloxacillin; 0%-meropenem; 1.0%-cefepime; 5.2%-ceftazidime; and 34.4%-piperacillin-tazobactam amongst baseline MSSA isolates assessed. A associated with cefazolin IE ( = 0.0011), whereas C associated with piperacillin-tazobactam IE ( < 0.0001). Baseline demographics did not reveal specific risk factors for IE-associated infections, nor were long-term outcomes different. Herein, we observed the IE in CF-derived MSSA disproportionally for cefazolin and piperacillin-tazobactam and this phenotype strongly associated with underlying genotype. The confirmation of CF being a high density infection, and the identification of high prevalence of MSSA with IE in CF supports the need for prospective pulmonary exacerbation treatment studies to understand the impact of this phenotype.
Topics: Adult; Humans; Adolescent; Methicillin; Cefazolin; Staphylococcus aureus; Anti-Bacterial Agents; Prospective Studies; Cystic Fibrosis; Staphylococcal Infections; Monobactams; Piperacillin, Tazobactam Drug Combination; Ceftazidime; beta Lactam Antibiotics; Microbial Sensitivity Tests
PubMed: 37966229
DOI: 10.1128/aac.00136-23 -
Microbial Pathogenesis Jun 2023Staphylococcus aureus is a common disease-causing bacterium that has developed resistances to a wide variety of antibiotics. This increasing antibiotic resistance has...
Staphylococcus aureus is a common disease-causing bacterium that has developed resistances to a wide variety of antibiotics. This increasing antibiotic resistance has made management of these infections difficult. A better understanding of the general differences among clinical S. aureus strains beyond the well characterized resistance mechanisms may help in identifying new anti-microbial targets. This study aimed to identify and compare the general differences in protein profiles among clinical strains of S. aureus sensitive and resistant to methicillin. The proteomic profiles of five methicillin sensitive (MSSA) and five methicillin resistant (MRSA) S. aureus strains were analyzed by ultra-performance liquid chromatography-mass spectrometry. Protein identification was done using Progenesis QI for Proteomics and the UniProt S. aureus database. Proteins that play roles in virulence, metabolism, and protein synthesis were found to be present at different abundances between MSSA and MRSA (Data available via ProteomeXchange with identifier PXD021629). This study shows differences in protein profiles between antibiotic sensitive and antibiotic resistant clinical strains of S. aureus that may affect the resistance mechanism. Further research on these differences may identify new drug targets against methicillin resistant S. aureus strains.
Topics: Humans; Methicillin; Methicillin Resistance; Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus; Proteomics; Anti-Bacterial Agents; Staphylococcal Infections; Microbial Sensitivity Tests
PubMed: 37086911
DOI: 10.1016/j.micpath.2023.106121 -
Communicable Diseases Intelligence... Nov 2023From 1 January to 31 December 2022, fifty-five institutions across Australia participated in the Australian Staphylococcus aureus Surveillance Outcome Program (ASSOP)....
From 1 January to 31 December 2022, fifty-five institutions across Australia participated in the Australian Staphylococcus aureus Surveillance Outcome Program (ASSOP). The aim of ASSOP 2022 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that were antimicrobial resistant, with particular emphasis on susceptibility to methicillin and on characterisation of the molecular epidemiology of the methicillin-resistant isolates. A total of 3,214 SAB episodes were reported, of which 77.5% were community-onset. Overall, 15.0% of S. aureus were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 21.4%, which was significantly different to the 16.8% all-cause mortality associated with methicillin-susceptible SAB (p = 0.02). With the exception of the β-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus was rare. However, in addition to the β-lactams, approximately 31% of methicillin-resistant S. aureus (MRSA) were resistant to ciprofloxacin; 30% to erythromycin; 13% to tetracycline; 11% to gentamicin; and 2% to co-trimoxazole. One MRSA isolate, with a daptomycin MIC of 1.5 mg/L, harboured the A302V mprF and A23V cls2 mutations. When applying the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, teicoplanin resistance was detected in one MRSA isolate. Resistance to vancomycin or linezolid was not detected. Resistance to non-β-lactam antimicrobials was largely attributable to the healthcare-associated MRSA (HA-MRSA) clone ST22-IV [2B] (EMRSA-15), and to the community-associated MRSA (CA-MRSA) clone ST45-V [5C2&5] which has acquired resistance to multiple antimicrobials including ciprofloxacin, clindamycin, erythromycin, gentamicin, and tetracycline. The ST22-IV [2B] (EMRSA-15) clone is the predominant HA-MRSA clone in Australia. Nonetheless, 86% of methicillin-resistant SAB episodes were due to CA-MRSA clones. Although polyclonal, approximately 72% of CA-MRSA clones were characterised as ST93-IV [2B] (Queensland clone); ST5-IV [2B]; ST45-V [5C2&5]; ST1-IV [2B]; ST30-IV [2B]; ST97-IV [2B]; ST953-IV [2B]; and ST8-IV [2B]. As CA-MRSA is well established in the Australian community, it is important to monitor antimicrobial resistance patterns in community- and healthcare-associated SAB as this information will guide therapeutic practices in treating S. aureus bacteraemia.
Topics: Humans; Staphylococcal Infections; Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus; Anti-Bacterial Agents; Bacteremia; Agar; Cross Infection; Methicillin; Australia; Drug Resistance, Bacterial; Anti-Infective Agents; Erythromycin; Ciprofloxacin; Gentamicins; Tetracycline
PubMed: 37968066
DOI: 10.33321/cdi.2023.47.67 -
Proteomics Jan 2020Staphylococcus aureus is a highly successful human pathogen responsible for a wide range of infections. This study provides insights into the virulence, pathogenicity,...
Staphylococcus aureus is a highly successful human pathogen responsible for a wide range of infections. This study provides insights into the virulence, pathogenicity, and antimicrobial resistance determinants of methicillin-susceptible and methicillin-resistant S. aureus (MSSA; MRSA) recovered from non-healthcare environments. Three environmental MSSA and three environmental MRSA are selected for proteomic profiling using isobaric tag for relative and absolute quantitation tandem mass spectrometry (iTRAQ MS/MS). Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway annotation are applied to interpret the functions of the proteins detected. 792 proteins are identified in MSSA and MRSA. Comparative analysis of MRSA and MSSA reveals that 8 of out 792 proteins are upregulated and 156 are downregulated. Proteins that have differences in abundance are predominantly involved in catalytic and binding activity. Among 164 differently abundant proteins, 29 are involved in pathogenesis, antimicrobial resistance, stress response, mismatch repair, and cell wall synthesis. Twenty-two proteins associated with pathogenicity including SPA, SBI, CLFA, and DLT are upregulated in MRSA. Moreover, the upregulated pathogenic protein ENTC2 in MSSA is determined to be a super antigen, potentially capable of triggering toxic shock syndrome in the host. Enhanced pathogenicity, antimicrobial resistance, and stress response are observed in MRSA compared to MSSA.
Topics: Anti-Bacterial Agents; Methicillin; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Proteomics; Staphylococcus aureus; Tandem Mass Spectrometry
PubMed: 31872541
DOI: 10.1002/pmic.201900221 -
ACS Biomaterials Science & Engineering Mar 2021Polyphenols have been extensively exploited in the biomedical field because of their wide range of bioactive properties and historical use as traditional medicines. They...
Polyphenols have been extensively exploited in the biomedical field because of their wide range of bioactive properties and historical use as traditional medicines. They typically present antioxidant, antimicrobial, antiamyloidogenic, and/or antitumor activities. In particular, cork water extracts and their components, have been previously reported to present antioxidant and antiamyloidogenic properties. On the basis of this knowledge, we tested cork water extract (CWE), cork water enriched extract (CWE-E), vescalagin/castalagin (two of the main polyphenols present in CWE and CWE-E) for their antibacterial activity against four bacterial strains, namely, methicillin-resistant (MRSE), (SA), methicillin-resistant (MRSA), and (PA). Vescalagin and castalagin presented bactericidal activity against all the tested bacterial strains, in particular toward the methicillin-resistant ones, i.e., MRSA and MRSE, as well as the ability to inhibit the formation of biofilms and to disrupt preformed ones. Moreover, vescalagin/castalagin seem to modulate the normal assembly of the peptidoglycans at the bacteria surface, promoting the disruption of their cell wall, leading to bacterial cell death. We also demonstrate that vescalagin/castalagin can be loaded into alginate hydrogels to generate antibacterial biomaterials that are not toxic to eukaryotic cells.
Topics: Hydrolyzable Tannins; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests
PubMed: 33596039
DOI: 10.1021/acsbiomaterials.0c01698