Microbial drug resistance最新文献

{"title":"N-Acetyl Cysteine and Vitamin C Modulate the Antibiotic Efficacy Against <i>Escherichia coli</i> Cells.","authors":"Princi Sharma, Ram Kumar, Anushka Bari, Sudheer Kumar Singh","doi":"10.1089/mdr.2024.0135","DOIUrl":"10.1089/mdr.2024.0135","url":null,"abstract":"<p><p>Supplements with their own beneficial effect on hosts are consumed by us. N-acetyl cysteine (NAC) and Vitamin C (Vit C) are antioxidants and supplements, consumed for their beneficial properties. The present investigation evaluates the effect of their antioxidant property on antibiotic efficacy against <i>Escherichia coli</i> cells from different physiological states, including exponential and stationary-phase, cell aggregates, and <i>in-vitro</i> stress-induced persister cells. Survival was measured in cfu/mL by cfu (colony-forming unit) counting, with efficacy determined by log-fold change in survival by comparing CFUs in antibiotics alone and antibiotic + antioxidant combinations. Fluoroquinolones in the presence of NAC reduced ∼1 log CFUs of log-phase and persister cells, while Vit C reduced CFUs (∼1-3-log increase) of cells from all physiological states. Aminoglycosides results were inconclusive; streptomycin's activity declined (∼1-3-log increase in survival), whereas amikacin's activity potentiated (∼1-log reduction in cfu/mL). Rifampicin's showed reduced activity (∼2-3 log increase in survival) with Vit C in all the states and a ∼1-2 log increase with NAC, especially in cell aggregates and persisters. Beta-lactams activity showed variability, with amoxicillin and ampicillin not being influenced, but ceftriaxone showed significant reduction of efficacy (∼2-3-log increase in survival) in all the treatments. The findings suggest that the overall impact of antioxidants on antibiotic efficacy varies depending on the antibiotic class.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"87-93"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CRISPR Elements and Their Association with Macrolide and Aminoglycoside Resistance Genes in Enterococci.","authors":"Rafael L do Rêgo, Felipe P G Neves, Filipe M Miranda, Amanda B da Silva, Amanda S Cabral, Bárbara A Dos Santos, Jailton L C Lima, Aline R V de Souza","doi":"10.1089/mdr.2024.0236","DOIUrl":"10.1089/mdr.2024.0236","url":null,"abstract":"<p><p>CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems are common among enterococci and may prevent the acquisition of mobile genetic elements carrying antimicrobial resistance genes. In this study, we correlate the presence of CRISPR with genes associated with macrolide resistance and high-level resistance to aminoglycosides (HLR-A) among 216 <i>Enterococcus faecalis</i> and 82 <i>Enterococcus faecium</i> isolates. We used PCR to detect genes associated with macrolide resistance, HLR-A, and type II-A CRISPR elements. We used two-tailed Fisher's exact test to evaluate correlation between CRISPR and resistance genes. One hundred and seven (35.9%) isolates had at least one HLR-A gene; the prevalent genes were <i>aac(6')-Ie-aph(2″)-Ia</i> and <i>ant(6)-Ia</i> found in 61 (57%) and 46 (43%) isolates, respectively. The macrolide resistance genes <i>erm</i>(A) and <i>erm</i>(B) were found in 116 (38.9%) isolates. Overall, 174 (58.4%) isolates had at least one CRISPR element; the predominant one was CRISPR3-Cas (<i>n</i> = 117; 39.2%). The presence of three genes, two related to HLR-A [<i>aph(2″)-Ic</i> and <i>ant(6)-Ia</i>] and one macrolide resistance gene [<i>erm</i>(B)], was associated with the absence of CRISPR (<i>p</i> < 0.05), mainly in <i>E. faecalis</i> lacking CRISPR3-Cas. We observed the association between the absence of CRISPR and the presence of major aminoglycoside and macrolide resistance determinants, contributing to the understanding of the evolution of resistance in enterococci.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"75-79"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143605728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Letter to the Editor:</i> Isolation of Carbapenemase-Producing <i>Pseudomonas aeruginosa</i> from a Waste-Water Sample Collected from a Greek University Hospital.","authors":"Lazaros A Gagaletsios, Ibrahim Bitar, Costas C Papagiannitsis","doi":"10.1089/mdr.2024.0226","DOIUrl":"10.1089/mdr.2024.0226","url":null,"abstract":"","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"94-95"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143370877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial Efficacy of Electrolyzed Waters and Chlorine-Based Disinfectants: The Role of pH, Free Chlorine, and Oxidation-Reduction Potential Over Time.","authors":"Angelica Luevanos-Aguilera","doi":"10.1089/mdr.2024.0213","DOIUrl":"10.1089/mdr.2024.0213","url":null,"abstract":"<p><p>This study evaluated the antimicrobial efficacy of electrolyzed water (EW) and chlorine-based disinfectant (CLD) over time, focusing on the impact of pH, free chlorine (FCL), and oxidation-reduction potential (ORP). EW and CLD are commonly used for wound care and surgical instrument disinfection, but their chemical instability limits their use. The study was conducted in the Microbiology Laboratory of the University of Guanajuato, using <i>Escherichia coli</i> ATCC 25922 as the test organism. Disinfectants were maintained at 40°C, with systematic monitoring of pH, FCL, and ORP. Minimum bactericidal concentration was used to assess antimicrobial activity before and after thermal exposure. Statistical analyses included Kruskal-Wallis one-way ANOVA, and the Friedman test. Results showed that the antimicrobial activity of EW depended on FCL concentration, with a significant correlation between the absence of FCL and increased minimum bactericidal concentration (<i>p</i> < 0.01). Disinfectants with alkaline pH demonstrated greater stability over time (<i>p</i> < 0.01). The findings highlight the importance of FCL, pH, and ORP in the effectiveness of these disinfectants and underscore their limitations due to chemical instability in clinical settings.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"80-86"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143605724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic Potential of Curcumin-Vancomycin Therapy in Combating Methicillin-Resistant <i>Staphylococcus aureus</i> Infections: Exploring a Novel Approach to Address Antibiotic Resistance and Toxicity.","authors":"Anupam Guleria, Nida Fatima, Anuj Shukla, Ritu Raj, Chinmoy Sahu, Narayan Prasad, Ashutosh Pathak, Dinesh Kumar","doi":"10.1089/mdr.2024.0231","DOIUrl":"10.1089/mdr.2024.0231","url":null,"abstract":"<p><p>Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) infections pose serious treatment challenges, particularly in peritoneal dialysis patients due to their increased susceptibility to infections and antibiotic resistance. Vancomycin, a standard antibiotic treatment for MRSA, is currently being compromised due to the evolution of multidrug-resistant microorganisms. Therefore, there is an urgent need for alternative therapeutic strategies to obstruct the increasing antibiotic resistance and bacterial biofilm formation. The present study explores curcumin, a natural bioactive compound possessing antimicrobial and anti-inflammatory properties, as a potential therapeutic for MRSA. The standard optical density method confirmed the antibacterial activity of curcumin against <i>Staphylococcus aureus</i> (MTCC-3160). Furthermore, we investigated the impact of curcumin on bacterial metabolism. Metabolic analysis of <i>S. aureus</i> culture media over a 20-h period revealed that curcumin exerts bacteriostatic effects by inhibiting specific metabolic pathways, potentially linked to energy and sugar metabolism. Furthermore, the synergistic effect of curcumin combined with vancomycin was assessed against 20 clinical MRSA strains using the broth microdilution method. The results demonstrated that curcumin enhanced the antibacterial activity of vancomycin in 17 strains by reducing its minimum inhibitory concentration (MIC) significantly. The MIC of curcumin and vancomycin has been found to decrease significantly when used in combination, with curcumin's MIC decreased to as low as 0.5 µg/mL and vancomycin's MIC to 0.5 µg/mL for all strains. Synergistic effects were seen in 17 out of 20 strains, having fractional inhibitory concentration index values between 0.04 and 0.56. These findings suggest that curcumin-vancomycin combination therapy could offer an effective treatment strategy for MRSA infections which may combat antibiotic resistance and reduce treatment-related toxicity.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"65-74"},"PeriodicalIF":2.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding Compound Efflux from Gram-Negative Bacteria, a Final Frontier for Antibiotic Discovery.","authors":"Rebecca J Ulrich, Paul J Hergenrother","doi":"10.1089/mdr.2024.0195","DOIUrl":"https://doi.org/10.1089/mdr.2024.0195","url":null,"abstract":"<p><p>Multidrug-resistant bacterial infections are a rising threat to human health and currently account for 1.3 million deaths annually. Notably, 70% of these deaths are due to gram-negative pathogens, and no new classes of gram-negative-active antibiotics have been approved by the US Food and Drug Administration in the past 55 years. The challenges of converting compounds with <i>in vitro</i> biochemical activity to whole cell gram-negative antibacterial activity are significant, as the outer membrane and promiscuous efflux pumps thwart the potential of most antibiotic candidates. Significant strides have been made toward understanding compound penetration and accumulation in gram-negative bacteria, but efflux remains a major obstacle for antibiotic drug discovery. Recent advances in machine learning (ML) algorithms and increased accessibility of code and programs for the nonexpert suggest artificial intelligence could help address the efflux problem. Here, we discuss work toward understanding efflux and cast a vision for how ML can be utilized to address compound efflux from gram-negative bacteria.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influential Factors in the Treatment of <i>Pseudomonas aeruginosa</i> Infections at a Tertiary Hospital in Vietnam.","authors":"Tiep Khac Nguyen, Ngoc Khanh Le, Pham Hong Nhung, Thao Thi Huong Bui, Gang Wang, Françoise Van Bambeke, Phung Thanh Huong","doi":"10.1089/mdr.2024.0191","DOIUrl":"10.1089/mdr.2024.0191","url":null,"abstract":"<p><p>As an opportunistic pathogen, <i>Pseudomonas aeruginosa</i> is often associated with severe respiratory infections. A study conducted in an ICU of a tertiary hospital in Vietnam, where infection management is relatively good, yielded only 18 clinical isolates of <i>P. aeruginosa</i> over 6 months. Though the number is small, treating <i>P. aeruginosa</i> infections is highly complicated. Out of 18 patients, 15 showed no improvement after treatment, leading to worsening conditions or death, possibly due to various factors. High rates of mechanical ventilation (83.3%) may be a contributing factor, suggesting a certain correlation between ventilation and treatment failure. The antibiotic resistance rate in these isolates is relatively high, with a multidrug-resistant rate of 44.4%, resulting in treatment failures when empirical antibiotics are used without susceptibility testing. All isolates have the ability to form biofilms. Moreover, bacteria in stationary phase or within biofilms exhibited poor responses to meropenem and amikacin (about 10% of bacteria survive after antibiotic exposure). Conversely, ciprofloxacin shows much better efficacy, indicating that fluoroquinolones should be used in combination therapy for <i>P. aeruginosa</i> infection to eliminate persistent cells and biofilm-embedded microorganisms, thus enhancing treatment effectiveness.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"27-33"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142932298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of Multidrug-Resistant NDM-5-Producing ST307 <i>Klebsiella pneumoniae</i> in Uruguay, 2023.","authors":"Carmen Magallanes, Eliana Eugster, Felipe Clavijo, María Inés Siri, Jorge Cantero, Patricia Echeverría, Josefina Torello, Mercedes Castro, Carolina Márquez","doi":"10.1089/mdr.2024.0065","DOIUrl":"10.1089/mdr.2024.0065","url":null,"abstract":"<p><p>Carbapenem and colistin-resistant <i>Klebsiella pneumoniae</i> pose a significant threat to public health, particularly in intensive care units, due to high morbidity and mortality rates. This study aimed to analyze five NDM carbapenemase-producing multidrug-resistant <i>K. pneumoniae</i> isolates from different hospitals. Antimicrobial susceptibility testing, hypermucoviscosity analysis, biofilm production assessment, MLST, PCR, and whole-genome sequencing were conducted. All isolates harbored NDM-5 metallo-β-lactamase, belonging to MLST 307, were biofilm producers and exhibited a stop codon (Q30) along MgrB. Genomic analysis revealed multiple-replicon plasmids carrying resistance genes, notably <i>bla</i>_NDM-5, <i>bla</i>_CTX-M-15, <i>rmtB</i>, and <i>qnrB1</i>, with complex genetic structures encoding several mobile genetic elements, including the Tn3 family and IS26. All isolates harbored <i>wzi</i>173 (capsule-locus KL102), <i>iutA</i> (a siderophore-associated gene), and the type 3 fimbriae <i>mrkABCDFHIJ</i> operon. The core genome single nucleotide polymorphisms (SNPs) analysis suggests the circulation of two strains of ST307 clone (SNPs range differences 4-77). These findings highlight the potential plasticity of the high-risk ST307 clone and the urgent need for surveillance and intervention strategies to combat antimicrobial resistance. To our knowledge, this is the first report of <i>K. pneumoniae</i> ST307 carrying <i>bla</i>_NDM-5 and the first description of ST307 in Uruguay. The presence of <i>bla</i>_NDM-5 and pan-aminoglycoside resistance <i>rmtB</i> genes are identified for the first time in Uruguay.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"42-51"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143255568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Characterization of Colistin- and Carbapenem-Resistant <i>Klebsiella pneumoniae</i>: <i>mgrB</i> Mutations and Clonal Diversity in Pediatric Intensive Care Isolates.","authors":"Ayşe Hande Türk, Alper Tekeli, Duygu Öcal, Devran Gerçeker","doi":"10.1089/mdr.2024.0110","DOIUrl":"10.1089/mdr.2024.0110","url":null,"abstract":"<p><p>Colistin- and carbapenem-resistant <i>Klebsiella pneumoniae</i> (ColR CrKp) cause important health problems in pediatric intensive care units (PICUs) due to its ability to harbor multiple resistance genes and spread of high-risk clones. In this study, molecular epidemiological characteristics, transferable resistance genes, and <i>mgrB</i> alterations of ColR CrKp isolated from PICU were investigated. Isolates were identified by MALDI-TOF MS, and antimicrobial susceptibility tests were performed using disk diffusion method, gradient strip test, and broth microdilution method. Extended spectrum beta-lactamase, AmpC beta-lactamase, carbapenemase, 16S rRNA methyltransferase, plasmid-mediated quinolone resistance, and <i>mcr-1</i> to <i>-5</i> genes were investigated by polymerase chain reaction. Sanger sequencing was performed to obtain <i>bla</i>_OXA-48-like and <i>mgrB</i> sequences. Pulsed-field gel electrophoresis and multilocus sequence typing were used to determine the clonal spread of the isolates. Ten ColR CrKp harboring <i>bla</i>_OXA-48 (70%), <i>bla</i>_OXA-232 (20%), <i>bla</i>_CTX-M (90%), <i>armA</i> (20%), <i>qnrB</i> (20%), and <i>qnrS</i> (50%) were identified. No <i>mcr</i> genes were found, whereas <i>mgrB</i> mutations through modifications (A7T, C88T, and A121G) and insertion of an IS-1-like insertion sequence were determined. Isolates belonged to ST 14, ST 37, ST 101, ST 147, ST 661, ST 985, and ST 2096. It is crucial to determine the antimicrobial resistance properties and the clonal spread of the isolates to guide the treatment decisions, implement effective infection control measures, and develop novel antimicrobial strategies.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"34-41"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143033699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity and Evolution of the Mobilome Associated with Antibiotic Resistance Genes in <i>Streptococcus anginosus</i>.","authors":"Yingting Wang, Taoran Liu, Yi Sida, Yuanting Zhu","doi":"10.1089/mdr.2024.0229","DOIUrl":"10.1089/mdr.2024.0229","url":null,"abstract":"<p><p><i>Streptococcus anginosus</i> is an important cause of pyogenic infections, bacteremia, and chronic maxillary sinusitis. Mobile genetic elements (MGEs) play a key role in lateral gene transfer, resulting in broad transfer of antibiotic resistance genes (ARGs). However, studies on ARG-associated MGEs in <i>S. anginosus</i> are still rare. To fill this gap, we used sequencing data from 11 clinical <i>S. anginosus</i> to characterize their mobilome diversity through comparative analysis. We found 47 well-characterized MGEs, including 23 putative integrative and conjugative elements (ICEs), 16 prophages/integrative mobilizable elements, and 8 composites. They were inserted into 16 positions, 4 of which were hot spots. A comprehensive analysis revealed that ARG-associated ICEs belong to four groups as follows: single serine integrases (ICE<i>San</i>49.2), tyrosine integrases (ICE<i>San</i>26.2), triple serine integrase ICEs (ICE<i>San</i>195.1), and a putative transposon integrase (ICE<i>San</i>49.1), all of which were similar to ICEs/transposons widely distributed among other streptococci. The eight composites were composed of multiple ICEs or transposons through successive accretion events (tandem or/and internal integration). In conclusion, we found that <i>S. anginosus</i> accumulates a variety of ARG-associated ICE/composites that may enable <i>S. anginosus</i> to serve as an ARG-associated MGE repository for other streptococci. The analysis of composites here provides a paradigm to further study mobilome evolution.</p>","PeriodicalId":18701,"journal":{"name":"Microbial drug resistance","volume":" ","pages":"52-63"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143008483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}