Search Results (74)

Healthcare-associated infection, mainly through medical device-associated infection, remains a critical issue in hospital care. Bacterial adhesion, proliferation, and biofilm formation on the device surface have been considered the foremost cause of medical device-associated infection. Different means have been explored to reduce microbial attachment and proliferation, including forming a bactericidal or microbial adhesion-resistant surface layer. Fear of limited bactericidal capability if the dead microbes remained adhered to the surface has withheld the widespread use of a bactericidal surface in medical devices if it was intended for long-term use. By contrast, constructing a microbial adhesion-resistant or antifouling surface, such as a surface with zwitterionic functionality, would be more feasible for devices intended to be used for the long term. Nevertheless, a sophisticated multi-step chemical reaction process would be needed. Instead, a simple immersion method that utilized a novel mussel-inspired catechol compound with zwitterionic sulfobetaine functionality, ZDS, was explored in this investigation for the surface modification of substrates with distinctively different surface characteristics, including titanium and polyvinyl chloride. Dopamine, NaIO₄ oxidants, and chemicals that could affect ionic interactions (NaCl and polyethyleneimine) were added to the ZDS-containing immersion solution to compare their effects on modifying titanium and PVC substrates. Furthermore, a layer-by-layer immersion method, in which the substrate was first immersed in the no-ZDS-added dopamine-containing solution, followed by the ZDS-containing solution, was also attempted on the PVC substrate. By properly selecting the immersion solution formulation and additional NaIO₄ oxidation modification, the antibacterial capability of ZDS-modified substrates can be optimized without causing cytotoxicity. The maximum antibacterial percentages against S. aureus were 84.2% and 81.7% for the modified titanium and PVC substrate, respectively, and both modified surfaces did not show any cytotoxicity. Full article

Background: Reusable tourniquets are commonly used to aid venipuncture and blood collection. However, inadequate disinfection may lead to bacterial contamination and increase the risk of healthcare-associated infections (HAIs). Tourniquets can function as fomites, facilitating the spread of pathogenic bacteria. This study assessed microbial contamination of reusable tourniquets in the emergency department and operating theatre, focusing on clinically relevant HAI-associated pathogens. Methods: Tourniquets from four hospital departments (emergency: adult observation and resuscitation; surgical theatres: pediatric and adult general surgery) were sampled at three time points (n = 12). DNA was extracted and analyzed via 16S rRNA sequencing using NGS technology to identify microbial contamination and taxonomic composition. Results: Sequencing revealed 131 bacterial species across the 12 tourniquets, including clinically important pathogens. Among the top ten HAI-associated groups, Klebsiella spp. were detected in 5/12 samples, Enterococcus spp. in 9/12, Staphylococcus aureus in 1/12, Pseudomonas aeruginosa in 9/12, and Acinetobacter spp. in 10/12. No Escherichia coli, Clostridium difficile, coagulase-negative staphylococci, Proteus spp., or Enterobacter spp. were found. Emergency department tourniquets showed higher bacterial loads; operating theatres had greater species diversity. Conclusions: Reusable tourniquets harbor significant bacterial contamination. Considering disinfection challenges and the lack of guidelines, single-use tourniquets should be considered to reduce HAI risk. Full article

Ventilator-associated pneumonia (VAP) develops in patients who stay on mechanical ventilation for more than 48 h. In the presence of causative pathogens, the patient develops clinical signs such as purulent tracheal discharge, fever, and respiratory distress. A prospective observational study was carried out in the Intensive Care Unit (ICU) of Max Healthcare Centre, New Delhi, from 2020 to 2023. The study comprised 70 samples from patients diagnosed with VAP. This study thoroughly examined VAP-associated microorganisms and resistance in the hospital ICU. Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa were the most commonly reported pathogens. Significant drug resistance was seen in P. aeruginosa, K. pneumoniae, A. baumannii and Staphylococcus aureus. The heatmap also supported the antibiotic resistance data patterns obtained from conventional and automated systems of determination. Notably, Serratia marcescens, Escherichia coli, Klebsiella pneumoniae, Ralstonia insidiosa, and Ralstonia mannitolilytica, showed 60 to 100% of resistance to a number of antibiotics. Among all VAP patients, 31.42% early-onset and 68.57% late-onset VAP cases were detected. Out of 70 patients, 43 patients died (mortality rate 61.4%); majority of them suffered from late-onset VAP. The study goal was to describe the antibiotic resistance patterns and microbial ecology of the pathogens that were isolated from VAP patients. According to the heatmap analysis, a varied VAP microbiome with high prevalences of MDR in A. baumannii, P. aeruginosa, K. pneumoniae, and S. aureus was identified. To address the increasing prevalence of MDR VAP, the study highlights the critical need for improved VAP monitoring, strong infection control, and appropriate antibiotic usage. Full article

Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), poses significant challenges in healthcare settings due to its ability to form biofilms on various surfaces. These biofilms enhance bacterial survival and increase resistance to conventional treatments, complicating infection control efforts. This study evaluated the efficacy of combined povidone-iodine (PVP-I) and hydrogen peroxide (H₂O₂) to disrupt pre-formed S. aureus biofilms. A series of assays—including crystal violet staining, colony-forming unit (CFU) enumeration, gene expression analysis, and confocal laser scanning microscopy—were performed to assess the effects of each treatment individually and in combination. The combined treatment resulted in significantly greater reductions in biofilm biomass and viable bacteria compared with either agent alone. Gene expression analysis revealed downregulation of key biofilm-associated genes (icaA, icaB, icaD, icaR, and clfA), suggesting interference with biofilm stability and maintenance. While formal synergy quantification was not conducted, the observed effects suggest a potentially synergistic or additive interaction between the two agents. These findings support the use of dual antiseptic strategies as a promising approach to biofilm eradication and highlight the potential clinical utility of dual antiseptic strategies. However, we underscore the need for further optimization and safety evaluation. Full article

Background: Data from African neonatal units conducting bloodstream infection (BSI) surveillance is limited. Methods: Prospective clinical and laboratory surveillance of incident BSI episodes was conducted among in-patients at the 132-bed neonatal service at Tygerberg Hospital, Cape Town, South Africa (2017–2021), describing patient demographics, BSI rates, pathogen profiles, and empiric antibiotic concordance rates. Results: In total, 842 BSI episodes were identified in 740 neonates; most were preterm (661/740; 89.3%) and of low birth weight (640/740; 86.5%). The early onset BSI rate (<3 days of life) was 2.9/1000 live births, with S. agalactiae, K. pneumoniae, and E. coli predominating. Over time, ampicillin plus gentamicin coverage rates for early onset BSI pathogens declined from 93.8% to 63.6%. The healthcare-associated BSI rate (onset >3 days of life) was 3.4/1000 in-patient days, with K. pneumoniae, S. aureus, and S. marcescens predominating. Antibiotic coverage rates for healthcare-associated BSIs improved over time, from 72.2% to 89.2% (piperacillin plus amikacin) and from 68.1% to 84.6% (meropenem). Nearly one-third of BSI episodes were fatal (244/842; 29.0%), with two-thirds of these deaths considered BSI-attributable. Gram-negative BSIs increased mortality (OR 2.88; 95% CI 1.93–4.32) compared to Gram-positive BSIs (p < 0.001). Discordant empiric antibiotic therapy (OR 1.55; 95% CI 1.10–2.17) increased the risk of death compared to concordant therapy (p = 0.012). Conclusions: Neonatal BSI surveillance demonstrated that Gram-negative pathogens remain important causes of early onset and healthcare-associated BSIs in this resource-limited neonatal service. Declining coverage rates for empiric antibiotics prescribed for early onset BSI highlight the need for a change in treatment guidelines to minimise discordant therapy. Full article

Background: In the US, 120,000 cases of Staphylococcus aureus bacteremia (SAB) occur annually. Apart from mortality, little is known about other unfavorable outcomes (UOs). We developed a multifaceted definition for UOs in SAB and examined their incidence and predictors. Methods: We conducted a multicenter (~300 hospitals) retrospective cohort study between 2020 and 2022 of adult hospitalized patients with at least one blood culture (BC) positive for S. aureus. UOs were any of the following: hospital mortality, antibiotic escalation, persistently positive BCs, prolonged post-infection length of stay (LOS), 30-day readmission, and disease worsening. We compared the group with UOs to favorable outcomes (FOs). Regression models identified predictors of UOs. Results: Among 4080 patients with SAB, 2427 (59.5%) experienced a UO, most commonly 30-day readmission (42.0%) and antibiotic escalation (37.7%). Those with UOs more frequently had septic shock at admission (5.7% vs. 1.2%), requiring the ICU (18.8% vs. 14.7%) and dialysis (4.4% vs. 1.9%) prior to SAB onset. Community-onset SAB predominated in both groups, with more complicated SAB in the UO group (39.8% vs. 22.3%). Vancomycin use was similar, while daptomycin was more common in the UO group (8.5% vs. 3.0%). Variables with the highest odds ratios predicting a UO were septic shock on admission (3.498, 95% CI 2.145, 5.704), empiric daptomycin (2.723, 95% CI 1.943, 3.821), and complicated SAB (2.476, 95% CI 2.047, 2.994). Conclusions: UOs occur frequently in the setting of SAB. A broader perspective exploring issues other than mortality demonstrates the substantial implications of SAB both for patients and healthcare systems. Select clinical variables are associated with UOs, some of which may not be modifiable. Full article

Background/Objectives: Infection poses a significant threat of mortality in patients with chronic kidney disease (CKD) undergoing hemodialysis. Staphylococcus aureus (S. aureus) is a common etiological agent, with prior nasal colonization identified as a risk factor for infection. The aim of the present cross-sectional study was to determine the prevalence of nasal S. aureus carriage among patients with CKD undergoing dialysis at a university hospital and identify potential factors associated with colonization. Methods: Nasal swabs were obtained, and bacterial isolates were identified using matrix-assisted laser desorption/ionization time-of-flight spectrometry and antibiogram testing with the Vitek 2 system. Demographic and clinical data were collected for the investigation of risk factors associated with colonization. Results: Among the 96 patients analyzed, 34 were carriers of S. aureus. Among these carriers, three (8.8%) harbored oxacillin-resistant strains. More than half of the S. aureus strains exhibited resistance to clindamycin but susceptibility to oxacillin. Colonization was associated with age and the use of corticosteroids/immunosuppressants. Conclusions: The prevalence of nasal S. aureus carriage was high among patients undergoing dialysis at the university hospital, exceeding that found in the general population. Nasal colonization by S. aureus was linked to corticosteroid use and age. Understanding factors associated with S. aureus nasal colonization in patients on dialysis can assist healthcare providers in preventing the spread of infection and cross-contamination, while reducing risk in this population. Full article

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant burden globally, particularly in the Arabian Gulf region. The United Arab Emirates (UAE) has experienced rising MRSA prevalence, with increasing diversity in the clonal complexes (CCs) identified. The COVID-19 pandemic, with its increased hospitalization rates and antibiotic use, may have further influenced MRSA’s genetic evolution and epidemiology in the country. Methods: To investigate this influence, genomic profiling of 310 MRSA clinical isolates collected between February and November 2022 was performed using a DNA microarray-based assay. Results: Isolates were assigned to 22 clonal complexes and 72 distinct strain assignments. The predominant clonal complexes were CC5, CC6, CC361, CC22, CC1, and CC8. Community-acquired MRSA lineages were dominant, with only one healthcare-associated MRSA lineage isolate identified. Upward trends of CC1153 were observed along with rare CCs, such as CC121-MRSA and CC7-MRSA, with the latter being reported for the first time in the Arabian Gulf region. The presence of pandemic strains USA300 CC8-MRSA-[IVa + ACME1] and CC8-MRSA-IV strains were also observed, including variants lacking Panton–Valentine leukocidin (pvl) genes and missing tst1 or enterotoxin genes. The PVL-negative CC772-MRSA-V/VT was identified, representing its first report in the UAE. A novel variant, CC361-MRSA-IV (tst1+/PVL+), was identified. Pvl genes were observed in 36% of the isolates, primarily from skin and soft tissue infections, while fusC (SCC-borne fusidic acid resistance) was identified in 13% of the isolates. Conclusions: The findings highlight the ongoing evolution of MRSA in the UAE, with the persistence and emergence of diverse and rare clonal complexes, driving the need for continuous genomic surveillance. Full article

Staphylococcus aureus (S. aureus) represents one of the most frequent worldwide causes of morbidity and mortality due to an infectious agent. It is a part of the infamous ESKAPE group, which is highly connected with increased rates of healthcare-associated infections and antimicrobial resistance. S. aureus can cause a large variety of diseases. Protein A (PrA) is a cell-wall-anchored protein of S. aureus with multiple key roles in colonization and pathogenesis and can be considered as a marker of S. aureus. The development of aptasensors, having an aptamer as a specific biorecognition element, increases selectivity, especially when working with complex matrices. The association with state-of-the-art materials, such as MXenes, can further improve the analytical performance. A competitive aptasensor configuration based on a ferrocene (Fc)-labeled cDNA hybridized (cDNA-Fc S13) on a specific aptamer (APT) for PrA in the presence of MXene nanosheets was designed for the indirect detection of S. aureus. The aptasensor displayed a linear range of 10–125 nM, an LOD of 3.33 nM, and a response time under 40 min. This configuration has been tested in real samples from volunteers diagnosed with S. aureus infections with satisfactory results, enabling the perspective to develop decentralized devices for the rapid detection of bacterial strains. Full article

The high prevalence of catheter-associated urinary tract infections (CAUTIs) is causing significant concern in healthcare systems. Antibacterial urinary catheters have been developed to prevent CAUTIs in clinical application. In this work, a copper sulfide nanorod (CuS NR)-embedded urinary catheter (CuS/UC) was designed as an antibacterial urinary catheter with photothermal sterilization. The CuS NRs with low cytotoxicity were synthesized via the hydrothermal method. The CuS NRs were embedded into urinary catheters at different weight percentages. The CuS/UC exhibited homogenous surface roughness, low wettability, hydrophobicity, and low adhesiveness, promoting minimal interaction with bacteria and healthy cells. Under near-infrared (NIR) laser irradiation, the 0.8 weight percentage of CuS NRs in the urinary catheter (0.8CuS/UC) reached a temperature of 67.4 °C, demonstrating its photothermal antibacterial activity and suitability for catheter sterilization. Agar plate test verified that CuS/UCs exhibited a superior photothermal antibacterial activity against both Gram-negative Escherichia coli (E. coli) and Gram-positive Streptococcus aureus (S. aureus). Moreover, the 0.8CuS/UC exhibited excellent biocompatibility and anti-cell adhesion properties. The 0.8CuS/UC with photothermal performance, excellent biocompatibility, and anti-cell adhesion properties demonstrated its potential as a photothermal antibacterial catheter for clinical applications. Full article

Background: The oral cavity is an important but often overlooked reservoir for Staphylococcus aureus. The effective control and prevention of S. aureus colonization and infection in the oral and maxillofacial regions are crucial for public health. Fluoride is widely used in dental care for its remineralization and antibacterial properties. However, its effectiveness against S. aureus has not been thoroughly investigated. Objectives: This study aimed to evaluate the potential of combining sodium fluoride (NaF) with compounds to enhance its antibacterial and antibiofilm effects against S. aureus. Method: We found that a urea derivative significantly enhances the efficacy of fluoride by promoting the retention of fluoride ions within the cells. The synergistic antibacterial and antibiofilm effects of BPU with NaF were confirmed through various assays, including checkerboard assays, time-kill assays, and growth curve analysis. These findings were further supported by additional methods, including transmission electron microscopy (TEM), in silico simulations, and gene overexpression studies. Results: These findings suggest that targeting fluoride ion membrane exporters could enhance antibacterial efficacy. When combined with fluoride, 1,3-Bis [3,5-bis(trifluoromethyl)phenyl]urea (BPU) showed increased effectiveness in inhibiting S. aureus growth and reducing established biofilms. Conclusions: This novel combination represents a promising therapeutic strategy for treating biofilm-associated S. aureus infections, offering a new strategy in oral healthcare. To fully evaluate the clinical potential of this synergistic therapy, further in vivo studies are essential. Full article

Staphylococcus aureus is a biofilm-forming bacterium responsible for various human infections, one particularly challenging to treat due to its antibiotic resistance. Biofilms can form on both soft tissues and medical devices, leading to persistent and hard-to-treat infections. Combining multiple antimicrobials is a potential approach to overcoming this resistance. This study explored the effects of ursodeoxycholic acid (UDCA) combined with the antibiotic ciprofloxacin against S. aureus biofilms, aiming to evaluate any synergistic effects. Results showed that UDCA and ciprofloxacin co-treatment significantly reduced biofilm formation and disrupted pre-formed biofilms more effectively than either agent alone (p < 0.01). The combination also displayed a slight synergistic effect, with a fractional inhibitory concentration of 0.65. Additionally, the treatment reduced the production of extracellular polymeric substances, increased reactive oxygen species production, decreased metabolic activity, altered cell membrane permeability, and lowered cell surface hydrophobicity in S. aureus. Furthermore, it diminished biofilm-associated pathogenic factors, including proteolytic activity and staphyloxanthin production. Overall, the UDCA–ciprofloxacin combination shows considerable promise as a strategy to combat infections related to staphylococcal biofilms, offering a potential solution to the healthcare challenges posed by antibiotic-resistant S. aureus. Full article

Background/Objectives. The rise of antibiotic-resistant pathogens represents a significant global challenge in infectious disease control, which is amplified by the decline in the discovery of novel antibiotics. Staphylococcus aureus continues to be a highly significant pathogen, causing infections in multiple organs and tissues in both healthcare institutions and community settings. The bacterium has become increasingly resistant to all available antibiotics. Consequently, there is an urgent need for novel small molecules that inhibit the growth or impair the survival of bacterial pathogens. Given their large structural and chemical diversity, as well as often unique mechanisms of action, natural products represent an excellent avenue for the discovery and development of novel antimicrobial treatments. Anaephene A and B are two such naturally occurring compounds with significant antimicrobial activity against Gram-positive bacteria. Here, we report the rapid syntheses and biological characterization of five novel anaephene derivatives, which display low cytotoxicity against mammalian cells but potent antibacterial activity against various S. aureus strains, including methicillin-resistant S. aureus (MRSA) and the multi-drug-resistant community-acquired strain USA300LAC. Methods. A Sonogashira cross-coupling reaction served as the key step for the synthesis of the alkyl pyridinol products. Results/Conclusions. Using the compound JC-01-074, which displays bactericidal activity already at low concentrations (MIC: 16 μg/mL), we provide evidence that alkyl pyridinols target actively growing and biofilm-forming cells and show that these compounds cause disruption and deformation of the staphylococcal membrane, indicating a membrane-associated mechanism of action. Full article

Bacterial infections pose significant global health challenges, often underestimated due to difficulties in accurate diagnosis, especially when culture-based diagnostics fail. This study assesses the effectiveness of 16S-based metagenomic next generation sequencing (NGS) for identifying pathogens in culture-negative clinical samples across various medical settings. Overall, 48% of samples were collected from orthopedics, 15% from neurosurgery, and 12% in cardiac surgery, among others. The detection rate of monomicrobial infections was 68.6%, and 5.7% for polymicrobial infections. In addition, NGS detected bacteria in all samples from the lungs, head and neck, and eye specimens. Cutibacterium acnes (11%, 12/105) was the most frequent microorganism, followed by Staphylococcus epidermidis (10.4%, 11/105), and Staphylococcus aureus (9.5%, 10/105). In conclusion, 16S-targeted metagenomic sequencing enhances pathogen detection capabilities, particularly in instances where traditional cultures fail. By the combination of NGS and bacterial cultures, microbiologists might provide a more accurate diagnosis, guiding more effective treatments and potentially reducing healthcare costs associated with empirical treatments. Full article

Staphylococcus aureus, particularly drug-resistant strains, poses significant challenges in healthcare due to its ability to form biofilms, which confer increased resistance to antibiotics and immune responses. Building on previous knowledge that several flavonoids exhibit antibiofilm activity, this study sought to identify a novel flavonoid capable of effectively inhibiting biofilm formation and virulence factor production in S. aureus strains including MRSA. Among the 19 flavonoid-like compounds tested, 3,2′-dihydroxyflavone (3,2′-DHF) was identified for the first time as inhibiting biofilm formation and virulence factors in S. aureus with an MIC 75 µg/mL. The antibiofilm activity was further confirmed by microscopic methods. Notably, 3,2′-DHF at 5 µg/mL was effective in inhibiting both mono- and polymicrobial biofilms involving S. aureus and Candida albicans, a common co-pathogen. 3,2′-DHF reduces hemolytic activity, slime production, and the expression of key virulence factors such as hemolysin gene hla and nuclease gene nuc1 in S. aureus. These findings highlight the potential of 3,2′-DHF as a novel antibiofilm and antivirulence agent against both bacterial and fungal biofilms, offering a promising alternative to traditional antibiotics in the treatment of biofilm-associated infections. Full article