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Microorganisms Sep 2023Antibiotic resistance is a serious global health problem that poses a threat to the successful treatment of various bacterial infections, especially those caused by... (Review)
Review
Antibiotic resistance is a serious global health problem that poses a threat to the successful treatment of various bacterial infections, especially those caused by methicillin-resistant (MRSA) and vancomycin-resistant (VRE). Conventional treatment of MRSA and VRE infections is challenging and often requires alternative or combination therapies that may have limited efficacy, higher costs, and/or more adverse effects. Therefore, there is an urgent need to find new strategies to combat antibiotic-resistant bacteria. Probiotics and antimicrobial peptides (AMPs) are two promising approaches that have shown potential benefits in various diseases. Probiotics are live microorganisms that confer health benefits to the host when administered in adequate amounts. AMPs, usually produced with probiotic bacteria, are short amino acid sequences that have broad-spectrum activity against bacteria, fungi, viruses, and parasites. Both probiotics and AMPs can modulate the host immune system, inhibit the growth and adhesion of pathogens, disrupt biofilms, and enhance intestinal barrier function. In this paper, we review the current knowledge on the role of probiotics and AMPs in targeting multi-drug-resistant bacteria, with a focus on MRSA and VRE. In addition, we discuss future directions for the clinical use of probiotics.
PubMed: 37894051
DOI: 10.3390/microorganisms11102393 -
Journal of Global Antimicrobial... Mar 2024Staphylococcus epidermidis is a member of the human skin microbiome. However, in recent decades, multidrug-resistant and hospital-adapted S. epidermidis clones are...
OBJECTIVES
Staphylococcus epidermidis is a member of the human skin microbiome. However, in recent decades, multidrug-resistant and hospital-adapted S. epidermidis clones are increasingly involved in severe human infections associated with medical devices and in immunocompromised patients. In 2016, we reported that a linezolid- and methicillin-resistant S. epidermidis ST2 clone, bearing the G2576T mutation, was endemic in an Italian hospital since 2004. This study aimed to retrospectively analyse 34 linezolid- and methicillin-resistant S. epidermidis (LR-MRSE) strains collected from 2018 to 2021 from the same hospital.
METHODS
LR-MRSE were typed by Pulsed-Field Gel Electrophoresis and multilocus sequence typing and screened for transferable linezolid resistance genes. Representative LR-MRSE were subjected to whole-genome sequencing (WGS) and their resistomes, including the presence of ribosomal mechanisms of linezolid resistance and of rpoB gene mutations conferring rifampin resistance, were investigated.
RESULTS
ST2 lineage was still prevalent (19/34; 55.9%), but, over time, ST5 clone has been widespread too (15/34; 44.1%). Thirteen of the 34 isolates (38.2%) were positive for the cfr gene. Whole-genome sequencing analysis of relevant LR-MRSE displayed complex resistomes for the presence of several acquired antibiotic resistance genes, including the SCCmec type III (3A) and SCCmec type IV (2B) in ST2 and ST5 isolates, respectively. Bioinformatics and polymerase chain reaction (PCR) mapping also showed a plasmid-location of the cfr gene and the occurrence of previously undetected mutations in L3 (ST2 lineage) and L4 (ST3 lineage) ribosomal proteins and substitutions in the rpoB gene.
CONCLUSION
The occurrence of LR-MRSE should be carefully monitored in order to prevent the spread of this difficult-to-treat pathogen and to preserve the efficacy of linezolid.
Topics: Humans; Linezolid; Staphylococcus epidermidis; Methicillin-Resistant Staphylococcus aureus; Interleukin-1 Receptor-Like 1 Protein; Methicillin Resistance; Retrospective Studies; Staphylococcal Infections; Hospitals; Italy
PubMed: 38331029
DOI: 10.1016/j.jgar.2024.01.020 -
Journal of Basic Microbiology Apr 2024Free-living amoebae of the genus Acanthamoeba are infected by various bacteria in nature, and thus bacteria can protect themselves from adverse environmental conditions....
Free-living amoebae of the genus Acanthamoeba are infected by various bacteria in nature, and thus bacteria can protect themselves from adverse environmental conditions. Contrary to this ameba-bacteria relationship whether Acanthamoeba has antibacterial effects on bacteria is the different aspect of the relationship between these microorganisms. In this study, we investigate various Acanthamoeba strains have antibacterial effects on various Staphylococcus strains. Three environmental Acanthamoeba strains, isolated from various aquatic environments in Turkey, and Acanthamoeba castellanii ATCC 50373 standard strains were used in the study. The antistaphylococcal effect of cell-free supernatant (CFS) obtained from these amoebae against 12 different Staphylococcus bacteria was investigated by colony counting method. In addition, the pathogenicity of the tested Acanthamoeba strains was determined using osmotolerance and thermotolerance tests. CFSs obtained from Acanthamoeba were found to have varying degrees of antistaphylococcal effects on various Staphylococcus strains (0%-100%). It was determined that the CFS of the standard Acanthamoeba strain showed 100% inhibitory effect against one clinical methicillin-resistant Staphylococcus aureus strain (M2). Also, CFS of Ugöl strain showed 99.97% inhibitory effect against one clinical methicillin-sensitive Staphylococcus epidermidis strain (L3). It was determined that all Acanthamoeba isolates had no pathogenic potential. According to the results, it has been observed that Acanthamoeba produces antibacterial substance(s) against Staphylococcus bacteria and that the ameba-bacteria relationship may also result in the detriment of the bacteria. Furthermore, the current study indicates that new and natural antimicrobial agents from Acanthamoeba can be used as an alternative to infections caused by Staphylococcus.
Topics: Staphylococcus; Methicillin-Resistant Staphylococcus aureus; Acanthamoeba castellanii; Anti-Infective Agents; Anti-Bacterial Agents; Bacteria
PubMed: 38416601
DOI: 10.1002/jobm.202300551 -
Microbial Biotechnology Nov 2023Staphylococcus capitis is a member of the human and mammal skin microbiomes and is considered less harmful than Staphylococcus aureus. S. capitis subsp. urealyticus BN2...
Staphylococcus capitis is a member of the human and mammal skin microbiomes and is considered less harmful than Staphylococcus aureus. S. capitis subsp. urealyticus BN2 was isolated from a cat and expressed strong antibacterial activity against a range of Gram-positive species, most notably including S. aureus strains with resistance to methicillin (MRSA) and strains with intermediate resistance to vancomycin (VISA). These latter strains are normally relatively resistant to bacteriocins, due to cell wall and cell membrane modifications. Genomic sequencing showed that the strain harboured at least two complete gene clusters for biosynthesis of antagonistic substances. The complete biosynthetic gene cluster of the well-known lantibiotic gallidermin was encoded on a large plasmid and the mature peptide was present in isopropanol cell extracts. In addition, a chromosomal island contained a novel non-ribosomal peptide synthetase (NRPS) gene cluster. Accidental deletion of two NRPS modules and partial purification of the anti-VISA activity showed that this novel bacteriocin represents a complex of differently decorated, non-ribosomal peptides. Additionally, a number of phenol-soluble modulins (PSMs) was detected by mass spectrometry of whole cells. Producing these compounds, the strain was able to outcompete several S. aureus strains, including MRSA and VISA, in tube cultures.
Topics: Animals; Humans; Staphylococcus aureus; Staphylococcus capitis; Anti-Bacterial Agents; Bacteriocins; Staphylococcal Infections; Peptides; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Mammals
PubMed: 37850940
DOI: 10.1111/1751-7915.14356 -
Expert Opinion on Drug Safety Jan 2024Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep... (Review)
Review
Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future.
INTRODUCTION
Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA.
AREAS COVERED
The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.
EXPERT OPINION
The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.
Topics: Humans; Methicillin-Resistant Staphylococcus aureus; Staphylococcal Infections; Cephalosporins; Anti-Bacterial Agents; Ceftaroline; Bacteremia; Endocarditis
PubMed: 38145925
DOI: 10.1080/14740338.2023.2299377 -
Yi Chuan = Hereditas Nov 2023The disease caused by methicillin-resistant Staphylococcus aureus (MRSA) is a global public health challenge that threatens society and patients seriously. Therefore,...
The disease caused by methicillin-resistant Staphylococcus aureus (MRSA) is a global public health challenge that threatens society and patients seriously. Therefore, the molecular epidemiology and change trend of MRSA is essential for the control and treatment of diseases caused by the pathogen in their regions. To explore molecular epidemiology of MRSA in Hangzhou, we collected 162 MRSA isolates from 2012 to 2018, conducted the antimicrobial susceptibility and used polymerase chain reaction(PCR) to test the molecular typing including multilocus sequence typing (MLST), staphylococcal chromosome cassette mec (SCCmec), staphylococcal protein A (spa A) and Panton-Valentine leucocidin (PVL). All the strains was divided into community-associated MRSA (CA-MRSA) or hospital-associated MRSA (HA-MRSA). 162 MRSA isolates were divided into 16 STs and 30 spa types. The major ST type was ST5 (96/162, 59.3%) and the predominant spa type was t311 (83/162, 51.2%). Five SCCmec types were found and the most common SCCmec type was type II (101/162, 61.7%). ST5-II-t311 was the predominant MRSA clone. And the prevalence of ST5 MRSA gradually declined from 2014 to 2018 but the prevalence of ST59 MRSA significantly increased. At the same time, livestock-associated methicillin-resistant Staphylococcus aureus(LA-MRSA) ST398 and ST9 were detected. Twenty-eight isolates were PVL gene positive (28/162, 17.3%). The most prevalent PVL-positive clone was ST59-IVa-t437. Comparing with HA-MRSA, CA-MRSA had a lower probability of ST5 (9.1% vs 67.1%, P=0.000) but a higher probability of ST59 (63.6% vs 11.4%, P=0.000), not only that, it was more likely to carrying PVL-positive gene (36.4% vs 14.3%, P=0.028). In summary, the molecular types of MRSA were getting complex over time. ST5-II-t311 was the predominant clone of MRSA isolate with a downward incidence from 2014 to 2018. ST59 MRSA strains, which is thought community related strain are spreading into hospitals and has an upward incidence from 2014 to 2018.
Topics: Methicillin-Resistant Staphylococcus aureus; Staphylococcal Infections; China; Humans; Molecular Epidemiology; Multilocus Sequence Typing; Cross Infection; Hospitals; Microbial Sensitivity Tests; Bacterial Toxins; Leukocidins; Anti-Bacterial Agents; Exotoxins
PubMed: 38764272
DOI: 10.16288/j.yczz.23-166 -
Iranian Journal of Public Health Aug 2023Over the last decade, we were facing medical struggle by the emergence of multi-resistant bacteria, especially methicillin-resistant (MRSA). MRSA infections are still... (Review)
Review
Over the last decade, we were facing medical struggle by the emergence of multi-resistant bacteria, especially methicillin-resistant (MRSA). MRSA infections are still causing a growing global concern due to the rapid adaptive multidrug resistance to conventional antibiotics in human, community and veterinary medicine. Here we provide an overview about MRSA epidemiology, transmission and alternative potential treatments particularly new discovered phytochemicals with biological activity. In this narrative review, bibliographic data was collected from literature search databases: Google Scholar, web of science and PubMed/MEDLINE during recent years (2016 to 2021). MRSA is responsible of wide spectrum life threatening infections such us septicemia, endocarditis, and wound infections. It has epidemic potential in hospitals, that is responsible of most nosocomial infections leading to mortality and constitute a real burden for the healthcare systems. Effective preventive strategies for management of MRSA are highly required moreover, the identification and development of novel drugs or active biomolecules through phytochemicals are time challenging to face new resistant strains.
PubMed: 37744540
DOI: 10.18502/ijph.v52i8.13395 -
Antimicrobial Agents and Chemotherapy Nov 2023Daptomycin (DAP) is effective against methicillin-resistant (MRSA). However, reduced susceptibility to DAP in MRSA may lead to treatment failures. We aim to determine...
Daptomycin (DAP) is effective against methicillin-resistant (MRSA). However, reduced susceptibility to DAP in MRSA may lead to treatment failures. We aim to determine the distribution of DAP minimum inhibitory concentrations (MICs) and DAP heteroresistance (hDAP) among MRSA lineages in China. A total of 472 clinical MRSA isolates collected from 2015 to 2017 in China were examined for DAP susceptibility. All isolates ( = 472) were found to be DAP susceptible, but 35.17% (166/472) of them exhibited a high DAP MIC (MIC >0.5 µg/mL). The high DAP MIC group contained a larger proportion of isolates with a higher vancomycin or teicoplanin MIC (>1.5 µg/mL) than the low DAP MIC group (19.3% vs 7.8%, < 0.001; 22.3% vs 8.2%, < 0.001). We compared the clonal complex (CC) distributions and clinical characteristics in MRSA isolates stratified by DAP MIC. CC5 isolates were less susceptible to DAP (MIC = 1 µg/mL) than CC59 isolates (MIC = 0.5 µg/mL, < 0.001). Population analysis profiling revealed that 5 of 10 ST5 and ST59 DAP-susceptible MRSA isolates investigated exhibited hDAP. The results also showed that CC5 MRSA with an mutation (I238K) had a higher DAP MIC than those with a wild-type ( < 0.001). The -I238K mutation was found to be associated with dysfunction as indicated by the loss of δ-hemolysin production. In addition, defectiveness was associated with hDAP in MRSA. Whole-genome sequencing analysis revealed mutations in and / in DAP-resistant subpopulations, and most DAP-resistant subpopulations (6/8, 75%) were stable. Our study suggests that the increased DAP resistance and hDAP in MRSA may threaten the effectiveness against MRSA infections.
Topics: Humans; Daptomycin; Methicillin-Resistant Staphylococcus aureus; Anti-Bacterial Agents; Staphylococcal Infections; Vancomycin; Microbial Sensitivity Tests
PubMed: 37902403
DOI: 10.1128/aac.00563-23 -
Journal of Medical Microbiology Sep 2023Antibiotic resistance is a major threat to public health, particularly with methicillin-resistant (MRSA) being a leading cause of antimicrobial resistance. To combat...
Antibiotic resistance is a major threat to public health, particularly with methicillin-resistant (MRSA) being a leading cause of antimicrobial resistance. To combat this problem, drug repurposing offers a promising solution for the discovery of new antibacterial agents. Menadione exhibits antibacterial activity against methicillin-sensitive and methicillin-resistant strains, both alone and in combination with oxacillin. Its primary mechanism of action involves inducing oxidative stress. Sensitivity assays were performed using broth microdilution. The interaction between menadione, oxacillin, and antioxidants was assessed using checkerboard technique. Mechanism of action was evaluated using flow cytometry, fluorescence microscopy, and analysis. The aim of this study was to evaluate the antibacterial potential of menadione against planktonic and biofilm forms of methicillin-sensitive and resistant strains. It also examined its role as a modulator of oxacillin activity and investigated the mechanism of action involved in its activity. Menadione showed antibacterial activity against planktonic cells at concentrations ranging from 2 to 32 µg ml, with bacteriostatic action. When combined with oxacillin, it exhibited an additive and synergistic effect against the tested strains. Menadione also demonstrated antibiofilm activity at subinhibitory concentrations and effectively combated biofilms with reduced sensitivity to oxacillin alone. Its mechanism of action involves the production of reactive oxygen species (ROS) and DNA damage. It also showed interactions with important targets, such as DNA gyrase and dehydroesqualene synthase. The presence of ascorbic acid reversed its effects. Menadione exhibited antibacterial and antibiofilm activity against MRSA strains, suggesting its potential as an adjunct in the treatment of infections. The main mechanism of action involves the production of ROS, which subsequently leads to DNA damage. Additionally, the activity of menadione can be complemented by its interaction with important virulence targets.
Topics: Oxacillin; Methicillin-Resistant Staphylococcus aureus; Vitamin K 3; Methicillin; Staphylococcus aureus; Reactive Oxygen Species; Anti-Bacterial Agents; Biofilms
PubMed: 37707372
DOI: 10.1099/jmm.0.001751 -
Cureus Oct 2023Nasal carriage of species plays an important role in the epidemiology and pathogenesis of both community and healthcare-associated infections. Coinciding the emergence...
Prevalence of Mupirocin and Methicillin-Resistant Staphylococcus aureus in Nasal Carriage Among Healthcare Workers in an Intensive Care Unit and Post-decolonization Screening Outcomes at a Tertiary Care Hospital: A Prospective Study.
INTRODUCTION
Nasal carriage of species plays an important role in the epidemiology and pathogenesis of both community and healthcare-associated infections. Coinciding the emergence of methicillin-resistant (MRSA) is a challenge for clinicians to prevent their spread. Mupirocin is a topical antimicrobial agent approved for eradicating nasal carriage of staphylococcal species in adult patients and healthcare workers (HCWs). The increasing prevalence of mupirocin resistance among and coagulase-negative staphylococci species could be an important threat to the future use of mupirocin against MRSA.
OBJECTIVE
The aim of this study is to determine the prevalence of MRSA from nasal swabs of HCWs in intensive care units and its level of resistance pattern of mupirocin in all isolates of species by disk diffusion and epsilometer test (E-test) and to determine post decolonization screening.
MATERIALS AND METHODS
A total of 67 HCWs (doctors, nursing staff, technicians, and housekeeping staff) in the medical and surgical intensive care units were included in the study. Nasal swabs were collected from the subjects and cultured onto nutrient and blood agar, which were then incubated at 37ºC for 18 to 24 hours. and coagulase-negative species (CoNS) were identified by standard biochemical techniques. Methicillin resistance was detected by the disk diffusion method using a 30 µg cefoxitin disk as per the Clinical and Laboratory Standards Institute (CLSI) guidelines, and mupirocin resistance was detected using a 5 µg mupirocin disk. The resistance strains were further subjected to E-strip testing to determine the level of mupirocin resistance.
RESULTS
A total of 72 isolates were grown from the 67 subjects used in this study. Nine strains (12.5%) grew and 52 strains (72.2%) grew CoNS. Methicillin resistance was seen in five isolates (6.9%) of and 45 isolates (62.5%) of CoNS. Mupirocin resistance was seen in 11 isolates of methicillin-resistant coagulase-negative species (MRCoNS), where three isolates (4.1%) showed low-level mupirocin resistance MuL and eight isolates (11.11%) showed high-level mupirocin resistance MuH. None of the isolates of MRSA, methicillin-sensitive (MSSA), and methicillin-sensitive coagulase-negative species (MSCoNS) were resistant to mupirocin. Seven out of nine HCWs (77.8%) showed clearance of the organism after decolonization therapy.
CONCLUSION
The prevalence of emerging resistance to mupirocin in MRSA and MRCoNS is of great concern, especially in the nasal carrier state of HCWs. Hence, methicillin and mupirocin resistance in and CoNS must be detected in HCWs as a routine protocol, and decolonization measures should be undertaken to prevent healthcare-associated infections.
PubMed: 37927697
DOI: 10.7759/cureus.46435