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Purpose: Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a known risk factor for periprosthetic joint infection (PJI). In our facility, preoperative prophylaxis with mupirocin without the chlorhexidine soap scrub or vancomycin was consistently implemented for more than 15 years. This study aimed to evaluate the current screening and treatment of intranasal MRSA colonization in our elective primary THA patient population. Methods: All patients who underwent primary THA between April 2011, and March 2021 were included in this analysis. All patients were screened preoperatively for nasal MRSA approximately 1 month before surgery. Patients with nasal MRSA contamination are treated with topical mupirocin to eradicate the bacteria before surgery. The patients were examined again approximately two weeks before surgery. We evaluated the current screening and treatment of intranasal colonization with MRSA in our elective primary total hip arthroplasty (THA) patient population. Results: Out of 6251 patients, 106 (1.7%) had nasal MRSA contamination. The bacteria were not eradicated in three (3.6%) patients at the second screening. Twenty-two joints (0.35%) out of the 6251 had deep infections. Only 1 patient out of the 106 MRSA nasal carriers suffered from PJI. Twenty-one of the 6145 non-carriers had PJI. The difference between the prevalence of nasal MRSA contamination and the incidence of deep infections was not statistically significant. Conclusion: Our findings suggest that screening of all patients for nasal MRSA before THA followed by mupirocin calcium treatment if needed is sufficient PJI prophylaxis.
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Background and Aim: In the past, the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections in both humans and animals has increased across Thailand. Staphylococcus argenteus has been associated with infections among humans, exotic pets, and livestock. Both species have been identified in non-human primate species from geographically diverse locations but not from non-human primates in Thailand. This study aimed to determine the presence of MRSA/methicillin-susceptible S. aureus (MSSA) and S. argenteus isolates collected from buccal swab samples in Macaca fascicularis at Kosumpee Forest Park (KFP), Maha Sarakham, Northeast Thailand. Materials and Methods: Aseptic buccal swab samples were collected from 30 free-ranging macaques in November 2018. All isolates were tested using multiple biochemical tests and S. aureus latex slide agglutination test. Presumptive S. aureus isolates were tested for the presence of the mecA gene using polymerase chain reaction (PCR) assays. The isolates were phenotypically determined to be resistant to a ß-lactam antibiotic using the disk diffusion method with a 30 mg cefoxitin disk. The isolates were analyzed by PCR for the non-ribosomal peptide synthetase (NRPS) gene to distinguish S. argenteus from S. aureus. Results: Fifteen macaques (50%) were colonized with S. aureus and 21 isolates were characterized. Three of the macaques carried both the MRSA and MSSA isolate. One animal carried both MRSA and S. argenteus isolate, and one animal carried only S. argenteus. The NRPS gene analysis confirmed that 2 isolates (9.52%) were S. argenteus and 19 isolates (90.48%) were S. aureus [five MSSA and 14 MRSA]. Conclusion: This study is the first to identify MRSA/MSSA and S. argenteus in wild free-ranging M. fascicularis from Thailand at the KFP in Maha Sarakham. This study is also the first report on the occurrence of S. argenteus carriage in M. fascicularis from Thailand.
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OBJECTIVES: The increasing prevalence of antibiotic-resistant Staphylococcus aureus, besides the inadequate numbers of effective antibiotics, emphasises the need to find new therapeutic agents against this lethal pathogen. METHODS: In this study, to obtain antibody fragments against S. aureus, a human single-chain fragment variable (scFv) library was enriched against living methicillin-resistant S. aureus (MRSA) cells, grown in three different conditions, that is human peripheral blood mononuclear cells with plasma, whole blood and biofilm. The antibacterial activity of scFvs was evaluated by the growth inhibition assay in vitro. Furthermore, the therapeutic efficacy of anti-S. aureus scFvs was appraised in a mouse model of bacteraemia. RESULTS: Three scFv antibodies, that is MEH63, MEH158 and MEH183, with unique sequences, were found, which exhibited significant binding to S. aureus and reduced the viability of S. aureus in in vitro inhibition assays. Based on the results, MEH63, MEH158 and MEH183, in addition to their combination, could prolong the survival rate, reduce the bacterial burden in the blood and prevent inflammation and tissue destruction in the kidneys and spleen of mice with MRSA bacteraemia compared with the vehicle group (treated with normal saline). CONCLUSION: The combination therapy with anti-S. aureus scFvs and conventional antibiotics might shed light on the treatment of patients with S. aureus infections.
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As the burden of antibacterial resistance worsens and treatment options become narrower, rhodomyrtone-a novel natural antibiotic agent with a new antibacterial mechanism-could replace existing antibiotics for the treatment of infections caused by multi-drug resistant Gram-positive bacteria. In this study, rhodomyrtone was detected within the cell by means of an easy an inexpensive method. The antibacterial effects of rhodomyrtone were investigated on epidemic methicillin-resistant Staphylococcus aureus. Thin-layer chromatography demonstrated the entrapment and accumulation of rhodomyrtone within the bacterial cell wall and cell membrane. The incorporation of radiolabelled precursors revealed that rhodomyrtone inhibited the synthesis of macromolecules including DNA, RNA, proteins, the cell wall, and lipids. Following the treatment with rhodomyrtone at MIC (0.5-1 µg/mL), the synthesis of all macromolecules was significantly inhibited (p ≤ 0.05) after 4 h. Inhibition of macromolecule synthesis was demonstrated after 30 min at a higher concentration of rhodomyrtone (4× MIC), comparable to standard inhibitor compounds. In contrast, rhodomyrtone did not affect lipase activity in staphylococci-both epidemic methicillin-resistant S. aureus and S. aureus ATCC 29213. Interfering with the synthesis of multiple macromolecules is thought to be one of the antibacterial mechanisms of rhodomyrtone.
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Foot infections, being one of the major complications, account for nearly 15% of people with diabetes, and increase their risk for amputation in lower extremities. Though various factors contribute to the development of diabetic foot infection, poor glycemic control poses a greater risk paving the way for a number of micro-organisms to colonize the wound. In order to restore the lost granulation tissue at the ulcer site, the prime aim should not only be attaining glycemic control but also must focus on performing culture by clinically differentiating the stage of infection as well as to manage or control the infection by selecting a rational empiric antibiotic regimen, amidst the uncertainty that exists in choosing best antimicrobial therapy in emerging multi-drug resistance worldwide. This review mainly analyzes that although among the existence of various undefined microbiome being prevalent in causing diabetic foot infections, how the current trend of antibiotics in use aids in treating foot infections in diabetes.
Subject(s)
Communicable Diseases , Diabetes Mellitus , Diabetic Foot , Anti-Bacterial Agents/therapeutic use , Communicable Diseases/drug therapy , Diabetic Foot/drug therapy , HumansABSTRACT
Objective To establish the method of identifying MRSA with Taqman-fluorescence quantitative PCR basing on mecA/nuc/fem B three gene combined detecting.Methods Taking the coagulase positive MRSA,which isolated from the clinical samples and confirmed by VITEK 2 compact microbial analyzer,as the research obj ect,designed mecA/nuc/fem B specific PCR primers and Taqman fluorescent probe by bio-software PrimerPremier 5 and Designer Beacon 7,FAM,HEX and ROX markers were used to label the fluorescent probe at 5’,and the end of 3’was labeled with BHQ1,detected by fluo-rescence quantitative PCR instrment.Results ①1 g/dl gel electrophoresis results showed that the primer’s specificity of mec A/nuc/fem B were good,and molecular weight of the amplification band consistent with the expected molecular weight and no non-specific amplification band.②Three genes were obtained specific amplification in a single tube single channel and single tube multiple channel detection in PCR,and the three gene amplification effect in a single tube single tube single chan-nel and multichannel PCR similar.Conclusion Successfully established a method of multi channel Taqman-probe fluores-cence quantitative PCR identification of MRSA,mec A/nuc/fem B combined detection can effectively differentiate coagulase negative and positive MRSA,improve the accuracy of identification.
ABSTRACT
Staphylococcus aureus is one of the common cause of respiratory tract infections in children.Methi-cillin -resistant staphylococcusaureus was reported in 1 960s,then the resistance of other drugs were found in recent years,which leading to many problems in the clinical treatment.Clinician have to master the resistance trend and mechanism of this bacteria and decrease the speed of resistance as much as possible.
