Prevalence of multidrug-resistant strains in device associated nosocomial infection and their in vitro killing by nanocomposites

Antibacterial and Antibiofilm Potential of Ethanolic Extracts of Duguetia vallicola (Annonaceae) against in-Hospital Isolates of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen that is especially dominant in people with cystic fibrosis; the drug resistance expressed by this pathogen and its capacity for adaptation poses a significant challenge to its treatment and control, thereby increasing morbidity and mortality rates globally. In this sense, the search for new treatment alternatives is imminent today, with products of plant origin being an excellent alternative for use. The objective of this research was to evaluate the antibacterial and antibiofilm potential and to explore the possible effect of ethanolic extracts from the wood and bark of Duguetia vallicola on the cell membrane. Microdilution assays showed the inhibition of bacterial growth by more than 50%, with the lowest concentration (62.5 μg/mL) of both extracts evaluated. Furthermore, we report the ability of both extracts to inhibit mature biofilms, with inhibition percentages between 48.4% and 93.7%. Intracellular material leakage experiments (260/280 nm), extracellular pH measurements, and fluorescence microscopy with acridine orange (AO) and ethidium bromide (EB) showed cell membrane damage. This indicates that the antibacterial action of ethanolic extracts of D. vallicola is associated with damage to the integrity of the cell membrane and consequent death of these pathogens. These results serve as a reference for future studies in establishing the mechanisms of action of these extracts.

Enhanced in-vitro anti-Candida efficacy of Euphorbia milii Des Moul mediated copper nanoparticles against clinically isolated Candida albicans

Background and Purpose

Emergence of fungi as a pathogenic threat presents a significant challenge to public health, notably in intensive care units (ICUs) and among immunocompromised patients. Various factors, including sepsis-induced barrier disruptions, immune system dysfunction, and extremes of age, contribute to increased susceptibility to fungal infections. Hospital practices, such as prolonged surgeries, broad-spectrum antibiotic use, and invasive procedures, further exacerbate the risk. Fungal bloodstream infections, particularly those caused by Candida albicans, rank among the most common hospital-acquired infections, leading to substantial morbidity and mortality. The global rise in invasive candidiasis, particularly due to non-albicans Candida species, presents challenges in the diagnosis and treatment due to nonspecific symptoms and emerging antifungal resistance. Nanotechnology interventions particularly by utilizing green synthesized copper nanoparticles could possibly provide a novel solution to combat microbial colonization, biofilm formation, and drug resistance. This study aimed to assess the prevalence of candidemia, identify the distribution of causative Candida species, and understand their susceptibility patterns to commonly used antifungal agents for effective management in ICU settings. Additionally, the study sought to explore the in vitro anti-Candida activity of green copper nanoparticles synthesized using Euphorbia milii des moul extract.

Materials and Methods

This study was conducted at Microbiology Laboratory of Maharishi Markandeshwar Institute of Medical Sciences and Research from January to December 2022, focused on ICU patients suspected of bloodstream infections. Blood samples were collected aseptically and processed using BD BACTECTM culture vials. Identification of organisms was performed via the Vitek-2 system by confirming candidemia with positivity in both blood samples. After that antifungal susceptibility testing was also performed against Clinical and Laboratory Standards Institute recommended antifungal drug using Vitek 2 system. G-CuNPs were synthesized using E. milii Des moul extract and possessed for physiochemical characterization. The anti-Candida activity of G-CuNPs was evaluated through the MTT assay and time kill assay. After that generation of intracellular reactive oxygen species and DNA degradation were evaluated to understand its mechanism.

Results

This study identified a candidemia rate of 7.3% (58/789). Age and gender analysis revealed higher Candida colonization rates in individuals above 60 years old and females. Antifungal sensitivity profiling indicated notable resistance to fluconazole (27.59%) and voriconazole (25.86%). Synthesizing G-CuNPs using E. milii des moul extract represents a novel approach exhibiting significant fungicidal potency against clinically isolated C. albicans, supporting potential therapeutic applications.

Conclusion

the findings concluded that synthesized G-CuNPs have tremendous potential to battle against medical device-borne infections by surface coating.

Device-Associated Nosocomial Infections in Intensive Care Units at Al-Ahsa Hospitals, Saudi Arabia

Introduction Patients admitted to intensive care units (ICU), especially those with devices used to support their condition, are at a higher risk of getting healthcare-associated infections (HAIs). The aim of the present study was to analyze the surveillance data and assess the device-associated infection (DAI) rates such as central line-associated blood-stream infection (CLABSI), catheter-associated urinary tract infection (CAUTI), ventilator-associated pneumonia (VAP) and ventilator-associated event (VAE) in ICUs of the Ministry of Health (MoH) hospitals in Al-Ahsa region. Methodology The study was conducted retrospectively using the surveillance data of governmental hospitals' intensive care units in the Al-Ahsa region. The surveillance data was collected from 10 ICUs at six MoH hospitals in the Al-Ahsa region during the year 2022. The data from the participating hospitals was entered into the Health Electronic Surveillance Network (HESN) plus program by trained infection prevention control practitioners of the respective hospitals. Results An overall CLABSI rate of 4.29 per 1000 central line days was reported during the study period. The CAUTI rate was 0.55 with a range from 0 to 1.29 cases per 1000 urinary catheter days. VAP rate ranged from 0.33 to 2.21 cases per 1000 ventilator days (average of 1.17). The study reported VAE only for the adult medical-surgical ICU (3.36 per 1000 ventilator days). Conclusion The present study revealed that the most common DAIs in the Al-Ahsa region are CLABSI and CAUTI. DAI rates generated from this study may be used as benchmarks for regional hospitals. An educational program regarding the prevention and control of DAIs targeting all healthcare workers, especially ICU staff, has to be done in the Al-Ahsa region.

Mechanistic insights of Euphorbia milii des moul mediated biocompatible and non-cytotoxic, antimicrobial nanoparticles: an answer to multidrug resistant bacteria

The emergence of drug-resistant microbial pathogens is a matter of global concern and become more serious if they linked with healthcare-associated infections (HAIs). As per World Health Organization statistics, multidrug-resistant (MDR) bacterial pathogens account for between 7 and 12% of the worldwide burden of HAIs. The need for an effective and environmentally sustainable response to this situation is urgent. The primary goal of this study was to create copper nanoparticles that are biocompatible and non-toxic by using an extract of Euphorbia des moul, and then to test these nanoparticles' bactericidal efficacy against MDR strains of Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa, and Acinetobacter baumannii. UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy techniques were used to characterize the biogenic G-CuNPs. It was found that G-CuNPs were spherical in shape, with an average diameter of ~ 40 nm and a charge density of - 21.52 mV. The G-CuNPs fully eradicated the MDR strains at a dosage of 2 mg/ml with 3 h of incubation time. Mechanistic analysis showed that the G-CuNPs efficiently disrupted the cell membrane and damaged the DNA and by generating more reactive oxygen species. Moreover, cytotoxic examination revealed that G-CuNPs displayed < 5% toxicity at 2 mg/ml concentration on human RBCs, PBMCs, and A549 cell lines, suggesting that they are biocompatible. This nano-bioagent is an eco-friendly, non-cytotoxic, non-hemolytic organometallic copper nanoparticles (G-CuNPs) with a high therapeutic index for possible use in the prevention of biomedical device-borne infections by preparing an antibacterial layer on indwelling medical devices. However, its potential clinical use has to be further studied through in vivo testing with an animal model.

Novel Biocompatible Green Silver Nanoparticles Efficiently Eliminates Multidrug Resistant Nosocomial Pathogens and Mycobacterium Species

Bacterial infection is a major crisis of 21st era and the emergence of multidrug resistant (MDR) pathogens cause significant health problems. We developed, green chemistry-based silver nanoparticles (G-Ag NPs) using Citrus pseudolimon fruit peel extract. G-Ag NPs has a spherical shape in the range of ~ 40 nm with a surface charge of - 31 Mv. This nano-bioagent is an eco-friendly tool to combat menace of MDR. Biochemical tests prove that G-Ag NPs are compatible with human red blood cells and peripheral blood mononuclear cells. There have been many reports on the synthesis of silver nanoparticles, but this study suggests a green technique for making non-cytotoxic, non-hemolytic organometallic silver nanoparticles with a high therapeutic index for possible use in the medical field. On the same line, G-Ag NPs are very effective against Mycobacterium sp. and MDR strains including Escherichia coli, Klebsiella species, Pseudomonas aeruginosa, and Acinetobacter baumannii isolated from patient samples. Based on it, we filed a patent to Indian Patent Office (reference no. 202111048797) which can revolutionize the prevention of biomedical device borne infections in hospital pre/post-operated cases. This work could be further explored in future by in vivo experimentation with mice model to direct its possible clinical utility.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01061-0.

Antibacterial Screening of Isoespintanol, an Aromatic Monoterpene Isolated from Oxandra xylopioides Diels

The incidence of nosocomial infections, as well as the high mortality and drug resistance expressed by nosocomial pathogens, especially in immunocompromised patients, poses significant medical challenges. Currently, the efficacy of plant compounds with antimicrobial potential has been reported as a promising alternative therapy to traditional methods. Isoespintanol (ISO) is a monoterpene with high biological activity. Using the broth microdilution method, the antibacterial activity of ISO was examined in 90 clinical isolates, which included 14 different species: (Escherichia coli (38), Pseudomonas aeruginosa (12), Klebsiella pneumoniae (13), Acinetobacter baumannii (3), Proteus mirabilis (7), Staphylococcus epidermidis (3), Staphylococcus aureus (5), Enterococcus faecium (1), Enterococcus faecalis (1), Stenotrophomonas maltophilia (2), Citrobacter koseri (2), Serratia marcescens (1), Aeromonas hydrophila (1), and Providencia rettgeri (1). MIC90 minimum inhibitory concentration values ranged from 694.3 to 916.5 µg/mL and MIC50 values from 154.2 to 457.3 µg/mL. The eradication of mature biofilms in P. aeruginosa after 1 h of exposure to ISO was between 6.6 and 77.4%, being higher in all cases than the percentage of biofilm eradication in cells treated with ciprofloxacin, which was between 4.3 and 67.5%. ISO has antibacterial and antibiofilm potential against nosocomial bacteria and could serve as an adjuvant in the control of these pathogens.

Therapeutic Intervention for Various Hospital Setting Strains of Biofilm Forming Candida auris with Multiple Drug Resistance Mutations Using Nanomaterial Ag-Silicalite-1 Zeolite

Candida auris (C. auris), an emerging multidrug-resistant microorganism, with limited therapeutical options, is one of the leading causes of nosocomial infections. The current study includes 19 C. auris strains collected from King Fahd Hospital of the University and King Fahad Specialist Hospital in Dammam, identified by 18S rRNA gene and ITS region sequencing. Drug-resistance-associated mutations in ERG11, TAC1B and FUR1 genes were screened to gain insight into the pattern of drug resistance. Molecular identification was successfully achieved using 18S rRNA gene and ITS region and 5 drug-resistance-associated missense variants identified in the ERG11 (F132Y and K143R) and TAC1B (H608Y, P611S and A640V) genes of C. auris strains, grouped into 3 clades. The prophylactic and therapeutic application of hydrothermally synthesized Ag-silicalite-1 (Si/Ag ratio 25) nanomaterial was tested against the 3 clades of clinical C. auris strains. 4wt%Ag/TiZSM-5 prepared using conventional impregnation technique was used for comparative study, and nano formulations were characterized using different techniques. The antibiofilm activity of nanomaterials was tested by cell kill assay, scanning electron microscopy (SEM) and light microscopy. Across all the clades of C. auris strains, 4 wt%Ag/TiZSM-5 and Ag-silicalite-1 demonstrated a significant (p = 1.1102 × 10^-16) inhibitory effect on the biofilm's survival rate: the lowest inhibition value was (10%) with Ag-silicalite-1 at 24 and 48 h incubation. A profound change in morphogenesis in addition to the reduction in the number of C.auris cells was shown by SEM and light microscopy. The presence of a high surface area and the uniform dispersion of nanosized Ag species displays enhanced anti-Candida activity, and therefore it has great potential against the emerging multidrug-resistant C. auris.