Antibiotic-resistant Bacteria Research Articles

Prevalence, Molecular Characterization and Antibiogram Pattern of Livestock Associated Methicillin Resistant Staphylococcus aureus in Livebird Markets Gusau, Zamfara State, Nigeria

Study’s Excerpt The prevalence and antibiotic resistance patterns of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in poultry markets within the Gusau metropolis was examined. Phenotypic and molecular (PCR) detection methods were combined to identify the LA-MRSA isolates. Multidrug resistance (MDR) phenotypes were observed in 72.2% of the isolates. Full Abstract Poultry farms have been identified as hotspots for the emergence and spread of antibiotic-resistant bacteria, especially livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA). In this study, a total of 320 swab samples were randomly collected from fecal litter, Hands of poultry handlers, Soil, Feed, and Water from five different poultry markets in the Gusau metropolis. The LA-MRSA isolates involved were detected culturally and identified phenotypically by the use of PCR assay. The pooled prevalence of the LAMRSA isolates in the samples was 22(100%). The chi-square test was used to compare the prevalence of LAMRSA among the samples collected at 95% confidence interval and 0.05 level of significance. There is no statistically significant difference in the prevalence of LAMRSA among the samples. Findings from the antibiogram study conducted revealed that all the 22(100%) LAMRSA isolates were resistant to Penicillin antibiotics, with resistance to other antibiotics following the order: Nitrofurantoin, 17(77.3%), Sulphamethoxazole, 13(59.1%), Chloramphenicol 6(27.28%), Ciprofloxacin 5(22.7%) and Erythromycin 4(18.2%). A total of 14 multidrug resistant phenotypes were identified from the 22 LAMRSA isolates with 16(72.2%) demonstrating cross resistant to ≥3 of the six different classes of antibiotics used. The MDR rate in soil samples was the highest (27.3%) (p<0.05) compared to other MDR isolates from the other sources. Of all the isolates, 22(100%) demonstrated a MAR Index ranging from 0.2-0.8. These are disturbing trends with significant risks to humans and animals. Suggesting a potential for inoculation of self and transmission to others, particularly through those who sell and make daily contact with live birds. Therefore, the government should awaken the consciousness of poultry farmers/handlers by way of sensitization on the need to improve water quality and practice routine personal and environmental hygiene as it relates to poultry management, with a focus on antibiotic stewardship within the one health framework so as to lower endemicity and equally break the chain of transmission of LA- MRSA across the farm to fork continuum.

Synergistic effects of bacteriophage cocktail and antibiotics combinations against extensively drug-resistant Acinetobacter baumannii

BackgroundThe extensively drug-resistant (XDR) strains of Acinetobacter baumannii have become a major cause of nosocomial infections, increasing morbidity and mortality worldwide. Many different treatments, including phage therapy, are attractive ways to overcome the challenges of antibiotic resistance.MethodsThis study investigates the biofilm formation ability of 30 XDR A. baumannii isolates and the efficacy of a cocktail of four tempetate bacteriophages (SA1, Eve, Ftm, and Gln) and different antibiotics (ampicillin/sulbactam, meropenem, and colistin) in inhibiting and degrading the biofilms of these strains.ResultsThe majority (83.3%) of the strains exhibited strong biofilm formation. The bacteriophage cocktail showed varying degrees of effectiveness against A. baumannii biofilms, with higher concentrations generally leading to more significant inhibition and degradation rates. The antibiotics-bacteriophage cocktail combinations also enhanced the inhibition and degradation of biofilms.ConclusionThe findings suggested that the bacteriophage cocktail is an effective tool in combating A. baumannii biofilms, with its efficacy depending on the concentration. Combining antibiotics with the bacteriophage cocktail improved the inhibition and removal of biofilms, indicating a promising strategy for managing A. baumannii infections. These results contribute to our understanding of biofilm dynamics and the potential of bacteriophage cocktails as a novel therapeutic approach to combat antibiotic-resistant bacteria.

Probiotic-Loaded Bacterial Cellulose as an Alternative to Combat Carbapenem-Resistant Bacterial Infections

Background: Carbapenems are one of the mainstays of treatment for antibiotic-resistant bacteria (ARB). This has made the rise of carbapenem-resistant bacteria a threat to global health. In fact, the World Health Organization (WHO) has identified carbapenem-resistant bacteria as critical pathogens, and the development of novel antibacterials capable of combating infections caused by these bacteria is a priority. Objective: With the aim of finding new alternatives to fight against ARB and especially against carbapenem-resistant bacteria, we have developed a series of living materials formed by incorporating the probiotics Lactobacillus plantarum (Lp), Lactobacillus fermentum (Lf), and a mixture of both (L. plantarum+L. fermentum) into bacterial cellulose (BC). Results: These probiotic-loaded bacterial celluloses inhibited the proliferation of three ARB, including two carbapenem-resistant enterobacteria (CRE), identified as Klebsiella pneumoniae and Enterobacter cloacae, and a carbapenem-resistant Pseudomonas aeruginosa. Interestingly, while the probiotics L. plantarum, L. fermentum, and the mixture of both were found to be inactive against these ARB, they became active once incorporated into BC. Conclusions: The increase in activity is due to the known effect that cells increase their activity once incorporated into a suitable matrix, forming a living material. For the same reasons, the probiotics in the living materials BC–L. plantarum, BC–L. fermentum, and BC–L. plantarum+L. fermentum showed increased stability, allowing them to be stored with bacterial activity for long periods of time (two months).

Far-UVC light (222 nm) efficiently inactivates clinically significant antibiotic-resistant bacteria on diverse material surfaces.

This study is crucial, providing compelling evidence on Far-ultraviolet radiation C (Far-UVC) light's efficacy against clinically significant antibiotic-resistant bacteria-a pressing issue in microbiology and infection control. Our research employs antibiotic-resistant strains from clinically isolated bacteria, emphasizing real-world relevance. Simultaneously, we assess Far-UVC light (222 nm) across diverse material surfaces commonly found in clinical settings. This dual approach ensures practical applicability and broad relevance. Our comprehensive setup and rigorous methodologies unequivocally demonstrate Far-UVC light's potency in combating antibiotic-resistant bacteria. Since 222 nm far-UVC has a disinfection capability and is harmless to mammalian cells, this dual effectiveness positions Far-UVC as a secure tool for infection control, with potential applications in healthcare settings, mitigating antibiotic-resistant bacteria spread, and reducing healthcare-associated infections.

The Role of Reactive Oxygen Species from Heavy Metal: Effect on reactivity of Fish and Defensive Mechanism of Antibiotic Resistant Bacteria in Aquatic Environment

The Role of Reactive Oxygen Species from Heavy Metal: Effect on reactivity of Fish and Defensive Mechanism of Antibiotic Resistant Bacteria in Aquatic Environment

A Systematic Review of Aquatic Organism Antimicrobial Peptides

Antimicrobial peptides (AMPs), sourced from various organisms, including aquatic life, are promising alternatives to combat antibiotic resistance. Their investigation is essential amid global antibiotic resistance concerns. The invaluable impact of antibiotics on human health, having saved numerous lives, is currently at risk. The growing global incidence of antibiotic-resistant bacteria poses a serious challenge to their ability to effectively treat various illnesses. This situation demands immediate attention and the exploration of alternative medical solutions. One of the most promising alternatives to antibiotics is antimicrobial peptides (AMPs), which can treat bacterial infections, particularly those brought by multi-drug-resistant pathogens. With a particular focus on their antimicrobial properties, this systematic review aims to evaluate and classify recent AMPs isolated from aquatic organisms. This review advances knowledge of these aquatic life-derived AMPs’ potential as alternatives to conventional antibiotics by examining their unique antibacterial characteristics and modes of action. A systematic review of articles published in English between 2014 and 2024 was carried out in the Science Direct, PubMed NCBI and Google Scholar databases using keywords and inclusion and exclusion criteria. A total of 33 potential AMPs isolated from aquatic organisms had been reported, and 21 of the AMPs were reported to have functional antimicrobial activities. Continuous research and study of natural substances, particularly AMPs, remain critical in pursuing alternatives to conventional antibiotics for effective treatments in combating antibiotic resistance. Therefore, ongoing research holds significant importance in identifying and harnessing the potential of AMPs for future medical applications.

Occurrence of Multi-Drug-Resistant Bacteria in Rainbow Trout–Lettuce Bio-Integrated Culture Systems in Chile

In an aquaponic system, fish and plants are cultivated together in a symbiotic environment where they mutually benefit, using significantly less water than traditional farming methods. The main aim of this study was to investigate the occurrence of antimicrobial resistance in two aquaponic systems implemented in two Chilean high schools using rainbow trout and lettuce cultures. When water samples (fish tank, biofilter, and plant raft) were analyzed over a three-month period, no resistance to oxytetracycline was detected, whereas the occurrence of resistance to florfenicol was rather small, ranging from 0.01% to 3.1% of bacterial culturable counts. Eighteen isolates were recovered from various sources as representatives of the florfenicol-resistant population, and all of them belonged to the Pseudomonas genus, showing a multi-drug-resistance phenotype and exhibiting simultaneous resistance to 7–13 antimicrobials. All isolates exhibited resistance to amoxicillin, chloramphenicol, florfenicol, and furazolidone and susceptibility to meropenem, oxytetracycline, oxolinic acid, flumequine, ciprofloxacin, and enrofloxacin. Five and two isolates carried the amphenicol-resistance-encoding genes floR and cmlA, respectively, whereas no carriage of integrons or the fexA, fexB, pexA, optrA, and cfr genes encoding for florfenicol resistance was detected. Eleven isolates carried plasmids, but only two of them were able to transfer their plasmid content by conjugation. The knowledge of the microbiome associated with aquaponic systems is still scarce, and their role as potential reservoirs of antimicrobial-resistant bacteria and related genes of these systems must be elucidated.

A pan-genomic analysis based multi-epitope vaccine development by targeting Stenotrophomonas maltophilia using reverse vaccinology method: an in-silico approach.

Antibiotic resistance in bacteria leads to high mortality rates and healthcare costs, a significant concern for public health. A colonizer of the human respiratory system, Stenotrophomonas maltophilia is frequently associated with hospital-acquired infections in individuals with cystic fibrosis, cancer, and other chronic illnesses. The importance of this study is underscored by its capacity to meet the critical demand for effective preventive strategies against this pathogen, particularly among susceptible groups of cystic fibrosis and those undergoing cancer treatment. In this study, we engineered a multi-epitope vaccine targeting S. maltophilia through genomic analysis, reverse vaccination strategies, and immunoinformatic techniques by examining a total of 81 complete genomes of S. maltophilia strains. Our investigation revealed 1945 core protein-coding genes alongside their corresponding proteomic sequences, with 191 of these genes predicted to exhibit virulence characteristics. Out of the filtered proteins, three best antigenic proteins were selected for epitope prediction while seven epitopes each from CTL, HTL, and B cell were chosen for vaccine development. The vaccine was refined and validated, showing highly antigenic and desirable physicochemical features. Molecular docking assessments revealed stable binding with TLR-4. Molecular dynamic simulation demonstrated stable dynamics with minor alterations. The originality of this investigation is rooted in the thorough techniques aimed at designing a vaccine that directly targets S. maltophilia, a microorganism of considerable clinical relevance that currently lacks an available vaccine. This study not only responds to a pressing public health crisis but also lays the groundwork for subsequent research endeavors focused on the prevention of S. maltophilia outbreaks. Further evidence from studies in mice models is needed to confirm immune protection against S. maltophilia.

Insights into Acinetobacter baumannii AMA205's Unprecedented Antibiotic Resistance.

The rise of antibiotic-resistant bacteria in clinical settings has become a significant global concern. Among these bacteria, Acinetobacter baumannii stands out due to its remarkable ability to acquire resistance genes and persist in hospital environments, leading to some of the most challenging infections. Horizontal gene transfer (HGT) plays a crucial role in the evolution of this pathogen. The A. baumannii AMA205 strain, belonging to sequence type ST79, was isolated from a COVID-19 patient in Argentina in 2021. This strain's antimicrobial resistance profile is notable as it harbors multiple resistance genes, some of which had not been previously described in this species. The AmpC family β-lactamase blaCMY-6, commonly found in Enterobacterales, had never been detected in A. baumannii before. Furthermore, this is the first ST79 strain known to carry the carbapenemase blaNDM-1 gene. Other acquired resistance genes include the carbapenemase blaOXA-23, further complicating treatment. Susceptibility testing revealed high resistance to most antibiotic families, including cefiderocol, with significant contributions from blaCMY-6 and blaNDM-1 genes to the cephalosporin and carbapenem resistance profiles. The A. baumannii AMA205 genome also contains genetic traits coding for 111 potential virulence factors, such as the iron-uptake system and biofilm-associated proteins. This study underscores A. baumannii's ability to acquire multiple resistance genes and highlights the need for alternative therapies and effective antimicrobial stewardship to control the spread of these highly resistant strains.

A survey of healthcare workers on the acceptance and value of personal protective equipment for patient care.

Assess healthcare workers' (HCW) attitudes toward universal masking, and gowns and gloves used as part of transmission-based precautions. Cross-sectional survey. Academic, tertiary care medical center in Baltimore, Maryland. HCW who work in patient care areas and have contact with patients. In May 2023, a 15-question web-based survey was distributed by the hospital's communications team via email. The survey contained questions to assess HCW perceptions of universal masking policies prior to the availability of COVID-19 vaccines and at the time of the survey, and the use of gowns and gloves for transmission-based precautions. Descriptive statistics were used to summarize data. Differences in agreement with universal masking over time, level of agreement with gown and glove policies, and with all PPE types across respondent characteristics were assessed. 257 eligible respondents completed the survey. Nurses and patient care technicians (43%) and providers (17%) were the most commonly reported roles. Agreement with universal mask use decreased from 84% early in the pandemic to 55% at the time of the survey. 70% and 72% of HCW agreed masks protect themselves and others, respectively. 63% expressed any level of annoyance with mask wearing, the most often due to communication challenges or physical discomfort. 75% agreed with gown use for antibiotic-resistant bacteria compared with 90% for glove use. The majority of HCW agree with the use of PPE to prevent pathogen transmission in the healthcare setting. Agreement with universal mask use for patient care shifted during the COVID-19 pandemic.

Surface immobilization and properties optimization of phage hydrolase against Gram-negative bacteria

Immobilized hydrolase not only reduces the production of antibiotic-resistant bacteria, but also effectively improves the stability of hydrolase in external use. In this study, phage hydrolase LysSSE1 against Gram-negative bacteria were surface immobilized and optimized for their bactericidal activity. Different anti-pathogen surface materials were prepared, where LysSSE1 was immobilized on the glass surface with a silica-affinity peptide and into which different peptide linkers were introduced. Immobilized enzymes inserted into the natural amino acid peptide linker exhibited higher bactericidal activity, greater stability, and more consistent bactericidal performance compared to those without the peptide linker. Among these immobilized enzymes, LysSSE1-NL-SiAP1 exhibited the strongest bactericidal activity and the best repeatable bactericidal performance, which only reduced the original performance by about 5% after three bactericidal cycles. Modeling analysis suggested that the presence of peptide linker might increase the molecular flexibility of the proximal hydrolase domain to better interact with the bacterial substrate. Our surface immobilization strategy could be extended to other lytic proteins, providing support for the development of surface sterilization methods and materials.

Antimicrobial Resistance and Pathotypes of Escherichia coli Isolates from Yellow-Legged Seagulls (Larus michahellis) in Central Italy.

Seagulls are synanthropic wild birds that can contaminate, through their droppings, beaches, urban and peri-urban environments. This concern is more serious when seagulls eliminate antimicrobial-resistant pathogenic bacteria. This study analyzed the fecal samples from 137 yellow-legged seagulls (Larus michahellis) from Central Italy. A total of 218 Escherichia coli strains were isolated and analyzed for phenotypic and genotypic antimicrobial resistance and to identify the virulence genes characterizing different pathotypes. The disk diffusion method on all isolates found relevant resistance rates to ampicillin (38.99%), tetracycline (23.85%), and enrofloxacin (21.10%). On the basis of all results obtained with this test, 62 (28.44%) isolates were classified as multidrug-resistant (MDR) and 6 (2.75%) as extensive drug-resistant (XDR). Molecular analyses conducted on the strains phenotypically resistant to carbapenems, cephalosporins, and penicillins found 9/37 (24.32%) strains positive for blaOXA-48, 52/103 (50.49%) for blaTEM, 12/103 (11.65%) for blaCMY2, 3/103 (2.91%) for blaCTX, and 1/103 (0.97%,) for blaSHV. PCR to detect virulence genes characterizing different pathotypes found that 40 (18.35%) isolates had the astA gene, indicative of the enteroaggregative (EAEC) pathotype, 2 (0.92%) had cnf1, 2 (0.92%) had cnf2, and 1 (0.46%) had cdt-IV. All five (2.29%) strains were reportable as necrotoxigenic (NTEC), while 4 (1.83%) had both eaeA and escV, reportable as enteropathogenic (EPEC). Measures to limit seagulls' access where humans and other animals reside are pivotal to reduce the risk of infection with antimicrobial-resistant and pathogenetic E. coli strains.

Antibiotic resistance and resistome risks of inhalable bioaerosols at aeration tank of a full-scale wastewater treatment plant

Antibiotic resistome could be aerosolized under wastewater aeration processes, however, their seasonal variation, mobility, hosts, aerosolization behavior, and risk, are largely unknown. Herein, the antibiotic resistant pollution associated with fine particulate matter (PM2.5) from the actual aeration tank (AerT), was analyzed using metagenomic assembly. The antibiotic resistance of AerT-PM2.5 was characterized by significant seasonality. Antibiotic resistance genes (ARGs) in AerT-PM2.5, exhibited higher enrichment and mobility and were harbored more by pathogens than those in upwind-PM2.5, regardless of sampling season. Mobile ARGs were mainly flanked by transposase. Totally, 18 pathogenic antibiotic-resistant bacteria (PARB) carried more than one ARG, including 9 PARB with multiple ARG types. Although wastewater exerted a dominant source contribution for the airborne ARGs (47.31–55.56 %) and PARB (46.18–64.32 %), aeration endowed differential aerosolization capacity for various ARGs and PARB from wastewater. Airborne antibiotic resistome was mainly determined by bacterial community and indirectly influenced by meteorological conditions (i.e., relative humidity). Higher PM2.5-borne resistome risk was observed in AerT than upwind, and the most serious resistome risk of AerT-PM2.5 was found in winter. This study emphasizes the importance of wastewater aeration processes in emission of airborne antibiotic resistome and offers referenced information for mitigating air pollution in wastewater treatment plants.

Characterization and genomic analysis of phage vB_SmaP_c9-N, a novel Stenotrophomonas maltophilia podophage with antibiofilm activity.

Stenotrophomonas maltophilia strains are increasingly emerging as multidrug-resistant pathogens. Moreover, S. maltophilia commonly produces biofilms that enhance antibiotic resistance in bacteria. Phages are effective alternative drugs for treating S. maltophilia infections. In this study, the lytic phage vB_SmaP_c9-N (abbreviated as Φc9-N), which is specific for S. maltophilia, was isolated from Nanhu Lake, Wuhan, China. Electron microscopy observation revealed that Φc9-N is a podophage. Φc9-N is stable over a wide pH range, from pH 4 to 10, and its activity did not change after storage at 4°C for 2months. The latency period of Φc9-N is 5 min, and its outbreak period is 35min. Antibacterial tests showed that Φc9-N could effectively inhibit the growth of S. maltophilia c24. Moreover, the biofilm production of S. maltophilia c24 decreased when Φc9-N was administered either to the forming biofilm or to the mature biofilm. These results suggest that Φc9-N has application potential in clinical treatment. The genome of Φc9-N is a dsDNA of 43,170 bp with 55 putative unidirectional genes, 18 of which were assigned putative functions, while other genes encoded hypothetical proteins. Genome sequence comparisons and phylogenetic analysis indicated that Φc9-N represents a new species, and, together with the Stenotrophomonas phages BUCT700, BUCT703, BUCT598, and vB_SmaS_P15, can be included in the newly proposed genus "Maltovirus" in the family Autographiviridae.

Enhancing antibacterial efficacy through macrocyclic host complexation of fluoroquinolone antibiotics for overcoming resistance

The use of supramolecular assemblies in pharmaceuticals has garnered significant interest. Recent studies have shown that the activities of antibacterial agents can be enhanced through complexation with cyclic oligomers and metal ions. Notably, these complexes sometimes possess greater therapeutic properties than the parent drugs. To develop microbiologically potent supramolecular drugs, the complexation of macrocyclic hosts with fluoroquinolone (FQ) antibiotics was investigated. FQs are a successful family of antibiotics that target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, leading to bacterial cell death through the inhibition of DNA synthesis. However, antibiotic resistance resulting from the repeated use of FQs over time has limited their effectiveness against resistant pathogens. To overcome this issue, the encapsulation of FQs in polyphenolic macrocycles was investigated. This study highlights resorcinarene, a polyphenolic host with antibacterial properties, and its ability to chemically interact with FQs. The inclusion complexation process was analyzed using NMR and FTIR techniques. The binding constants determined by 1H-NMR titration revealed that levofloxacin forms more stable complexes with resorcinarene than with β-cyclodextrin, which aligned with MD simulations. Assessment of the geometric characteristics of the inclusion complexes using 2D NMR analysis confirmed that different moieties of various FQs can fit into a single host cavity and improve activity against gram-negative bacteria. Overall, these findings suggest that encapsulation in polyphenolic macrocycles is a promising strategy for utilizing FQs against antibiotic-resistant bacteria.

The STING signaling pathways and bacterial infection.

As antibiotic-resistant bacteria continue to emerge frequently, bacterial infections have become a significant and pressing challenge to global public health. Innate immunity triggers the activation of host responses by sensing "non-self" components through various pattern recognition receptors (PRRs), serving as the first line of antibacterial defense. Stimulator of interferon genes (STING) is a PRR that binds with cyclic dinucleotides (CDN) to exert effects against bacteria, viruses, and cancer by inducing the production of type I interferon and inflammatory cytokines, and facilitating regulated cell death. Currently, drugs targeting the STING signaling pathway are predominantly applied in the fields of modulating host immune defense against cancer and viral infections, with relatively limited application in treating bacterial infections. Given the significant immunomodulatory functions of STING in the interaction between bacteria and hosts, this review summarizes the research progress on STING signaling pathways and their roles in bacterial infection, as well as the novel functions of STING modulators, aiming to offer insights for the development of antibacterial drugs.

Antibiotics in broilers chicken production: a review of impacts, challenges and potential alternatives

Globally, the use of antibiotic in animal industry was well known in the 20th century. Antibiotics usage as therapeutic and subtherapeutic means of improving growth and feed efficiency in livestock was well documented in literature. However, continuous use of antibiotics in food animals for increased growth and disease prevention has resulted in the development of antibiotic resistant bacteria in animals. This has led to disease treatment failure in the affected animals. The problem of transmission of antibiotic resistant bacteria to human through food chain and contamination of environment is another challenge of antibiotic usage in poultry production. Hence, the ban was placed on antibiotic usage in animal production. The restriction to the use of animal growth promoting antibiotic has gained high compliance in the developed countries. However, in the third world countries, this is still a battle that is on-going. To achieve the 2023 Global Action Plan on Antimicrobial Resistance goal, a lot is still left to be done. This review synthesized information on implications of antibiotics use on broiler chickens’ production cost efficiency and profitability; impact of antibiotics mode of action, diseases prevention and treatments of infection in broiler chickens’ production; challenges of antibiotics residual effect on meat quality and safety and alternatives to synthetic antibiotic for broiler chickens’ production.

Investigating the impact of nanoplastics in altering the efficacy of clarithromycin antibiotics through In vitro studies

Plastics have significant global implications due to their environmental contamination from extensive use and improper disposal. Among plastic particles, nanoplastics (<1 μm) pose notable risks to organisms and ecosystems due to their high surface area, reactivity, and potential to carry environmental pollutants. This study explores the interaction between polystyrene nanoplastics (PSNPs) and clarithromycin (CLA), a broad-spectrum antibiotic, focusing on their combined impact on insulin (INS) and antibiotic-resistant (AMR) bacteria. PSNPs can adsorb CLA, leading to structural changes in insulin and affecting its physiological functions, potentially causing insulin resistance. Additionally, PSNPs reduce CLA's inhibitory effects on pathogenic bacteria, facilitating antibiotic resistance. Our research utilized UV–Vis Spectroscopy, FTIR, Fluorescence spectroscopy, and Circular dichroism (CD) spectroscopy to assess INS structural changes, alongside the Kirby-Bauer disk diffusion method for microbiological examination. The findings highlight the synergistic and antagonistic effects of PSNPs and CLA, underscoring the enhanced toxicity of CLA when adsorbed onto PSNPs and the complex interactions affecting both human health and bacterial resistance. Further studies are essential to fully understand these mechanisms and their broader implications.

Photoinactivation of Multidrug-Resistant mcr-1-Positive E. coli Using PCPDTBT Conjugated Polymer Nanoparticles under White Light.

The issue of antimicrobial resistance is an escalating concern within the scope of global health. It is predicted that the existence of antibiotic-resistant bacteria might result in an estimated annual death of up to 10 million by 2050, along with possible economic losses ranging from 100 to 210 trillion. This study reports the production of poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] nanoparticles (PCPDTBT-NPs) by nanoprecipitation as an alternative to tackle this problem. The size, shape, and optical features of these conjugated polymer NPs were analyzed. Their efficacy as photosensitizers against nonresistant (ATCC) and multidrug-resistant mcr-1-positive Escherichia coli was assessed under white light doses of 250 and 375 J·cm-2. PCPDTBT-NPs inactivated both E. coli strains exposed to white light at an intensity of 375 J·cm-2, while no antimicrobial effect was observed in the group not exposed to white light. Reactive oxygen species and singlet oxygen were detected using DCFH-DA and DPBF probes, allowing the investigation of the photoinactivation pathways. This work showcases PCPDTBT-NPs as photosensitizers to eliminate multidrug-resistant bacteria through photodynamic inactivation employing visible light.

A novel system for removing examinee’s exhaled air using an open, lightweight non-sealing facemask-a proof-of-concept study

Patients with respiratory infections (e.g., COVID-19, antimicrobial resistant bacteria) discharge pathogens to the environment, exposing healthcare workers and inpatients to deleterious complications. This study tested the performance of SPEAR-P1 (synchronized personal exhaled air removal system - prototype 1), which actively detects expiration and removes exhaled air using an open, non-sealing lightweight facemask connected to a deep vacuum generating unit (DVGU). Fourteen healthy examinees practiced breathing through facemasks at 30, 25 and 20 breaths per minute; oxygen and nebulized saline were added at later steps. To test the efficacy of removing exhaled air, CO2 was used as a proxy and its level was measured from the outer surface of the open facemask. Compared to the baseline recording, SPEAR-P1 reduced CO2 escaping from the facemask by 66% on average for all study steps and respiratory rates (p<0.001), reaching 85.55% on average at 20 breaths per minute (p<0.001). This study shows that removing exhaled air from examinees using an open, non-sealing lightweight facemask is feasible. Future development of this system will enhance its efficacy and provide a method to remove a patient's contaminating aerosol without the need to "seal" the patient, especially in settings where isolation rooms are not readily available.