Resistant Bacteria Research Articles

Toxic Effect of Heavy Metal Poisoning on Living Organisms in Water and Health Risk: A Central India Study

The main causes of this environmental catastrophe are pollutants such as iron, zinc, lead, nickel, and chromium that have entered the water system as a result of uncontrolled industrial effluent discharge in the area. This study finds resistant bacteria and shows the toxicity of heavy metals in industrial effluent near the steel industry. Five separate locations were used for water sampling, and 16s RNA sequencing of the microorganisms that were found was done along with physicochemical parameter analysis and atomic absorption spectrophotometer use. Different water samples’ conductivity, TDS, salinity, DO, turbidity, and pH levels indicate changes in the quality of the water. In addition to having higher values for each of these characteristics, Sample D3’s water samples had greater concentrations of heavy metals, suggesting contamination. Aspergillus niger and Aspergillus terreus were identified in all samples. Both Gram-negative and Gram-positive Bacilli’s resistance to heavy metals has been found to be a sign of microbial adaptation to exposure to heavy metals. 16s rRNA sequencing of microorganisms revealed their roles in heavy metal bioremediation processes. The delicate balance between the flora and fauna in the affected water bodies has been upset by the devastating losses in aquatic life. In this study, we presented the biological methods for eliminating heavy metals, which comprised both metabolically dependent and independent techniques.

Aeromonas and mcr–3: A Critical Juncture for Transferable Polymyxin Resistance in Gram-Negative Bacteria

Polymyxin antibiotics B and colistin are considered drugs of last resort for the treatment of multi-drug and carbapenem-resistant Gram-negative bacteria. With the emergence and dissemination of multi-drug resistance, monitoring the use and resistance to polymyxins imparted by mobilised colistin resistance genes (mcr) is becoming increasingly important. The Aeromonas genus is widely disseminated throughout the environment and serves as a reservoir of mcr–3, posing a significant risk for the spread of resistance to polymyxins. Recent phylogenetic studies and the identification of insertion elements associated with mcr–3 support the notion that Aeromonas spp. may be the evolutionary origin of the resistance gene. Furthermore, mcr–3-related genes have been shown to impart resistance in naïve E. coli and can increase the polymyxin MIC by up to 64-fold (with an MIC of 64 mg/L) in members of Aeromonas spp. This review will describe the genetic background of the mcr gene, the epidemiology of mcr-positive isolates, and the relationship between intrinsic and transferable mcr resistance genes, focusing on mcr–3 and mcr–3-related genes.

Risk factors for Beta-lactam and carbapenem-resistant bacteria causing post-burn infections

Background: Burn patients are predisposed to infection because of the loss of skin barrier protection and low immunity. This study aims to evaluate the risk factors of post-burn infections due to beta-lactam and carbapenem-resistant bacteria (CR) isolated from a major burn unit.Methods: The descriptive study was conducted at Jinnah Hospital Lahore’s Burn and Reconstructive Surgery Centre (JB & RSC) and the Institute of Microbiology and Molecular Genetics (MMG), University of the Punjab, Lahore. The clinical specimens of wound swabs, including the age, gender, socio-economic status, residence, occupation, hospital stay, wards, burn degree, total burnt surface area (TBSA%), etiology of burn, and other factors were recorded. Antimicrobial susceptibility testing (AST), ESBL and CR screening (Beta- lactam and carbapenem resistant bacteria) were performed using CLSI guidelines 2017.Results: The most dominant strain was Pseudomonas spp. 26.5% (n=106), followed by 15% (n=60) Klebsiella spp., and 7.5% (n=30) Acinetobacter spp. with ESBL-producing strains. Compared to nosocomial infections, community-acquired infections were observed in 314 (78.5%) patients with more ESBL production. There was a significant relation between burnt people having an age of ≤ 29 years with ESBL (p=0.985) and carbapenemases (p=0.694) infections. None of the other factors, like low socioeconomic status and more hospital stays had a significant correlation (p > 0.05).Concluded: It has been concluded that MDR gram-negative strains play a serious role in burn infections and demand suitable methods to decrease their number. Pseudomonas spp. was the most common post-burn infection causing bacteria. Unfortunately, a high frequency of burn infections was observed in the patients at a young age.Keywords: Post burn infections; Gram negative; MDR; Beta- lactam; Carbapenem resistant

Detection of PhoP-mediated colistin resistance in Gram-negative bacteria without mcr genes in human population in the Ho Municipality, Ghana

IntroductionAntimicrobial resistance (AMR) has become a global public health threat, with colistin emerging as a last-resort treatment option for multidrug-resistant Gram-negative infections. However, the emergence of colistin resistance, mediated by mechanisms like mutations in the PhoP gene, raises concerns about the future utility of this antibiotic. This study aimed to determine the prevalence of PhoP-mediated colistin resistance in Gram-negative bacteria isolated from the stool of residents in the Ho Municipality, Ghana. MethodsIn this cross-sectional study, 110 stool samples were collected from June 2021 to December 2022. Gram-negative bacteria were isolated, and colistin susceptibility was determined by broth microdilution. Genomic DNA from resistant isolates was extracted and sequenced using the Nanopore platform to detect the presence of the PhoP gene. ResultsOf the 107 Gram-negative isolates, 57 % were resistant to colistin. The PhoP gene was detected in 61.4 % of the colistin-resistant isolates, with the highest prevalence observed in Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. ConclusionThe study reveals a high prevalence of PhoP-mediated colistin resistance among Gram-negative bacteria colonizing residents in the Ho Municipality, highlighting the role of the gut microbiota as a reservoir for antibiotic resistance. Continued surveillance and a collaborative One Health approach are crucial to address this growing threat.

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.

Clinical pilot of bacterial transcriptional profiling as a combined genotypic and phenotypic antimicrobial susceptibility test.

Antimicrobial resistance is a growing health threat, but standard methods for determining antibiotic susceptibility are slow and can delay optimal treatment, which is especially consequential in severe infections such as bacteremia. Novel approaches for rapid susceptibility profiling have emerged that characterize either bacterial response to antibiotics (phenotype) or detect specific resistance genes (genotype). Genotypic and Phenotypic AST through RNA detection (GoPhAST-R) is a novel assay, performed directly on positive blood cultures, that integrates rapid transcriptional response profiling with the detection of key resistance gene transcripts, thereby providing simultaneous data on both phenotype and genotype. Here, we performed the first clinical pilot of GoPhAST-R on 42 positive blood cultures: 26 growing Escherichia coli, 15 growing Klebsiella pneumoniae, and 1 with both. An aliquot of each positive blood culture was exposed to nine different antibiotics, lysed, and underwent rapid transcriptional profiling on the NanoString platform; results were analyzed using an in-house susceptibility classification algorithm. GoPhAST-R achieved 95% overall agreement with standard antimicrobial susceptibility testing methods, with the highest agreement for beta-lactams (98%) and the lowest for fluoroquinolones (88%). Epidemic resistance genes including the extended spectrum beta-lactamase blaCTX-M-15 and the carbapenemase blaKPC were also detected within the population. This study demonstrates the clinical feasibility of using transcriptional response profiling for rapid resistance determination, although further validation with larger and more diverse bacterial populations will be essential in future work. GoPhAST-R represents a promising new approach for rapid and comprehensive antibiotic susceptibility testing in clinical settings.IMPORTANCEExposure to antibiotics causes differential transcriptional signatures in susceptible vs resistant bacteria. These differences can be leveraged to rapidly predict resistance profiles of Escherichia coli and Klebsiella pneumoniae in clinically positive blood cultures.

Whole-genome sequencing of toxigenic Clostridioides difficile reveals multidrug resistance and virulence genes in strains of environmental and animal origin

BackgroundClostridioides difficile has been recognized as an emerging pathogen in both humans and animals. In this context, antimicrobial resistance plays a major role in driving the spread of this disease, often leading to therapeutic failure. Moreover, recent increases in community-acquired C. difficile infections have led to greater numbers of investigations into the animal origin of the disease. The aim of this study was to evaluate the genetic similarities between 23 environmental and animal isolates by using whole-genome sequencing and to determine antimicrobial resistance and virulence factor genes in toxigenic C. difficile strains to provide important data for the development of diagnostic methods or treatment guidelines.ResultsThe most common sequence type was ST11 (87%), followed by ST2 (9%) and ST19 (4%). In addition, 86.95% of the strains exhibited multidrug resistance, with antimicrobial resistance to mainly aminoglycosides, fluoroquinolones, tetracycline and B-lactams; nevertheless, one strain also carried other resistance genes that conferred resistance to lincosamide, macrolides, streptogramin a, streptogramin b, pleuromutilin, oxazolidinone and amphenicol. In addition, a wide range of virulence factor genes, such as those encoding adherence factors, exoenzymes and toxins, were found. However, we observed variations between toxinotypes, ribotypes and sequence types.ConclusionsThe results of this study demonstrated significant genetic similarity between ST11 strains isolated from environmental sampling and from animal origin; these strains may represent a reservoir for community-acquired C. difficile infection, which is becoming a growing public health threat due to the development of multridug resistant (MDR) bacteria and the number of virulence factors detected.

Green synthesis of anethole-loaded zinc oxide nanoparticles enhances antibacterial strategies against pathogenic bacteria.

The threat of antibiotic resistance is escalating, diminishing the effectiveness of numerous antibiotics due to the rapid development of resistant bacteria. In response, the use of green-synthesized nanoparticle, alone or combined with antimicrobial agents, appears promising. This study explores the effectiveness of zinc oxide nanoparticles (ZnONPs) synthesized using Loranthus cordifolius leaf extracts and subsequently coated with anethole. The fabrication of these nanoparticles was confirmed via UV-Vis, FTIR and TEM analyses, ensuring the nanoparticles were produced as intended. Utilizing a nanoprecipitation process that excludes evaporation and drying, a high drug loading capacity of 16.59% was accomplished. The encapsulation efficiency for anethole was recorded at 88.23 ± 4.98%. Antibacterial efficacy was assessed by com paring the green-synthesized ZnONPs (average size: 14.47nm), anethole-loaded ZnONPs (average size: 14,75nm), and commercially sourced ZnONPs. The ZnONPs with anethole demonstrated superior inhibition against all tested bacterial strains, including Gram-negative species like Pseudomonas aeruginosa and Escherichia coli, and Gram-positive species like Bacillus subtilis and Staphylococcus aureus, outperforming the commercially available ZnONPs. Additionally, anethole-coated ZnONPs showed the greatest inhibition of Gyr-B activity (IC50 = 0.78 ± 0.2M), better than both green-synthesized and commercially available ZnONPs. These findings emphasize the enhanced antimicrobial properties of ZnONPs, particularly when combined with green synthesis and anethole loading, highlighting their potential in various biomedical applications.

Assessing the spread of sulfachloropyridazine in poultry environment and its impact on Escherichia coli resistance

Sulfachloropyridazine (SCP) is an antimicrobial (AM) commonly used in the poultry industry. This drug is excreted as the original compound, which may accumulate in litter. This work was done to assess whether SCP residues from droppings of broiler chickens that were treated with therapeutic doses of this drug spread into the production environment and to determine if these events were associated with the selection of resistant bacteria. To this end, broiler chickens were raised under controlled conditions, and their droppings and litter were processed to detect and identify SCP residues using an HPLC-MS/MS technique. This study selected Escherichia coli as an indicator bacterium for AM resistance. Its phenotypic resistance was determined using the Kirby-Bauer disk diffusion method, and its genotypic resistance was determined by performing a conventional PCR test. Our results showed that SCP residues did spread from the treated group to untreated sentinel groups because SCP residues in the litter reached levels up to 43.05 µg·kg−1 in a group placed immediately adjoining to the treated group, while another group placed 30 cm away showed a concentration of 29.79 µg·kg−1. Meanwhile, only trace concentrations were detected in droppings collected from sentinel groups. Of 239 strains of E. coli isolated from droppings, 12.13 % were resistant to sulfonamides, whereas 23.91 % of 92 E. coli isolated from broiler litter were resistant. The most prevalent resistance gene was the sul2 gene, both in droppings and litter, followed by the sul1 gene. The SCP concentrations were associated with the probability of E. coli being resistant to sulfonamides (p-value = 0.01). A Multiple Correspondence Analysis (MCA) also showed that phenotypic and genotypic resistances were associated and that both genes sul1 and sul2 would determine phenotypic resistance to sulfonamides in E. coli. The results presented in this study show that inedible by-products of the poultry industry are potentially a source of drug resistance that can spread from the animal production line to the environment, so awareness of the correct use of antimicrobials is essential to combat antimicrobial resistance.

Anti-Bacterial Action of Silver Nanoparticles Against MDR Bacteria Isolated from Hospital

Hospital-associated infections (HAIs) are considered to be a major source of infections in patients, especially in patients with permanently impaired immunity. There is alarming increase of multi drug resistant (MDR) bacteria and Antibacterial medication resistance has been deemed a serious hazard to public health by the World Health Organisation (WHO). The study aimed to isolate and identify main bacteria caused nosocomial infection, and trying to treatments by using nanoparticles. By measuring the antibacterial activity of the synthesised AgNPs using the agar disc diffusion technique, AgNPs demonstrated antibacterial properties against the Pseudomonas aeruginosa and Staphylococcus aureus MDR.

Biosynthesis of silver nanoparticles by endophytic fungus Fusarium porliferutum isolated from Allium Sativum and its antimicrobial effect against multidrug resistant bacteria

Biosynthesis of silver nanoparticles by endophytic fungus Fusarium porliferutum isolated from Allium Sativum and its antimicrobial effect against multidrug resistant bacteria

Membrane Composition Allows the Optimization of Berberine Encapsulation in Liposomes.

Berberine (BBR) is a natural molecule with noteworthy pharmacological properties, including the prevention of antibiotic resistance in Gram-negative bacteria. However, its oral bioavailability is poor, thus resulting in an impaired absorption and efficacy in humans. In combination with other drugs, liposomes have been shown to enhance the availability of the drug, representing a smart delivery system to target tissues and reduce negative side effects. To date, there is a lack of studies on BBR and liposomes that enable the rationalization and molecular-based design of such formulations for future use in humans. In this work, the encapsulation of BBR into liposomes is proposed to overcome current limitations using a combination of experimental and computational assays to rationalize the membrane composition of liposomes that maximizes BBR encapsulation. First, the encapsulation efficiency was measured for several membrane compositions, revealing that it is enhanced by cholesteryl hemisuccinate and, to a lesser extent, by cholesterol. The physical basis of the BBR encapsulation efficiency and permeability was clarified using molecular dynamics simulation: using the lipid composition, one can tune the capability of membranes to attract, i.e., to adsorb, the molecules onto their surface. Overall, these findings suggest a rational strategy to maximize the encapsulation efficiency of liposomes by using negatively charged lipids, thus representing the basis for designing delivery systems for BBR, useful to treat, e.g., antibiotic resistance.

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.

Clinical features of chronic tibial osteomyelitis: a single-center retrospective study of 282 cases in Xinjiang, China.

Chronic osteomyelitis is a highly prevalent and severe orthopaedic complication, representing a critical unresolved issue. The clinical symptoms of osteomyelitis are influenced by various factors, including geography, lifestyle, and pre-existing medical conditions.This study aims to provide theoretical basis for treatment and prevention of osteomyelitis by investigating and analyzing clinical features and pathogen distribution among 282 patients with chronic tibial osteomyelitis in xinjiang. A total of 282 patients with chronic tibial osteomyelitis from January 1, 2012 to January 1, 2022 in the First Affiliated Hospital of Xinjiang Medical University were retrospectively analyzed. All data were collected from electronic medical record (EMR) system including demographics, etiology, risk factors, osteomyelitis location and clinical classification. Farmers, students, unemployed and retirees accounted for a relatively large proportion of the 282 patients. There were 233 males and 49 females with a gender ratio of 4.75:1. The average age was 40.21 ± 15.68 years and was mainly concentrated in 41-50 years, specifically, the mean age of females was slightly older than that of males. Education level was mostly primary and secondary school education, and illiteracy. Risk factors of chronic tibial osteomyelitis included history of smoking and drinking, history of multiple repeated surgeries, and impaired immunity. Frequent clinical symptoms were in the order of pain, local swelling, pus discharge and skin ulceration. Among all inflammatory markers, proportion of positive results were 30.85%, 59.93% and 53.90% for white blood cell (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), respectively. Positive rate of pathogenic microorganism culture was low and the three most common bacteria were Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). The most frequent site of infection was middle tibia. According to Cierny-Mader osteomyelitis classification, the most common types were type IIIA, IVA and IIA. Number of visits due to chronic osteomyelitis increased year by year, with young and middle-aged male farmers and low education level as the main groups. Smoking and drinking were two considerable risk factors that should be attached to a great importance. No significant increase was found in inflammatory markers and lower positive rate of pathogenic microorganism culture was observed. Multi-drug resistant bacteria were common and S. aureus remained the most frequent pathogen. Elevated ESR had certain diagnostic value for osteomyelitis. Type III and type IV osteomyelitis accounted for a large proportion which posed great challenges for clinical diagnosis and treatment.

Detection of carbapenem-resistant gram-negative bacilli in Japan using the fully automated bacterial testing device RAISUS S4

ObjectiveWe investigated a rapid detection method for carbapenemase-producing gram-negative bacilli (CP-GNR) using meropenem (MEPM) to assess the efficiency of the antimicrobial susceptibility testing. MethodsWe used the function that can monitor the growth curve with the resistant bacteria monitoring function (RAISUS S4). Rapid detection of CP-GNR was performed using RAISUS S4 in two types of antimicrobial susceptibility testing, the RAISUS 18-hour method (18-h method) and RAISUS rapid method (rapid method) for Enterobacterales (F-GNR) and non-fermenting Gram-negative bacilli (NF-GNR). ResultsWhen F-GNR were based on MEPM MIC ≥ 0.25 μg/mL, CP-GNR were detected with a sensitivity of 100% (58/58) for the 18-h method and 98.3% (57/58) for the rapid method; the shortest detection times were 5.3 and 4.0 h, respectively. When NF-GNR were based on MEPM MIC > 8 μg/mL, it was possible to detect CP-GNR with 100% sensitivity (58/58) in both methods. Furthermore, in the analysis using the 18-h method for monitoring resistant bacteria, when ≥ 2 µg/mL was used as the screening concentration for F-GNR, approximately 50% of the resistant genotypes, NDM, GES, and KPC, were detected in approximately 7 h. However, detecting the IMP and VIM took 11–12 h. ConclusionsThe 18-h and rapid methods with RAISUS S4 were highly correlated with the results of the microdilution method of CLSI, and CP-GNR detection was rapid using a function that can monitor the growth curve with RAISUS S4.

Electrochemical sensor for the detection of serine β-lactamase catalytic activity

A new approach is proposed based on the use of electrodes modified with carbon nanomaterials to determine enzymatic activity and screening for inhibitors of serine β-lactamases such as extended spectrum β-lactamases (ESBLs). These enzymes are responsible for the development of antibiotic resistance of pathogenic bacteria to β-lactam antibiotics. Electrochemical oxidation of cephalosporin antibiotic cefotaxime was effectively registered at a potential E from +596 to +625 mV (relative to Ag/AgCl). This property makes it possible to determine the change in cefotaxime concentration in solution upon interaction with serine β-lactamases. By analyzing the electrochemical characteristics of the cefotaxime oxidation reaction, the kinetic parameters of its hydrolysis catalyzed by the serine β-lactamase CTX-M-116 were determined. The Michaelis constant was KM = 50 µM and the maximum rate of the catalytic reaction was 1.67∙10–6 M/min. A comparative analysis of the electrochemical parameters of the enzyme/substrate cefotaxime and enzyme/substrate cefotaxime/inhibitor sulbactam (SBT) systems was carried out. Inhibition of β-lactamase by sulbactam was characterized by an IC50 value of 2.5 μM. The proposed approach can be used for screening new substrates and inhibitors of β-lactamases.

Boosting Expression of a Specifically Targeted Antimicrobial Peptide K in Pichia pastoris by Employing a 2A Self-Cleaving Peptide-Based Expression System.

Background/Objectives: The current epidemic of drug-resistance bacterial strains is one of the most urgent threats to human health. Antimicrobial peptides (AMPs) are known for their good activity against multidrug resistance bacteria. Specifically targeted AMPs (STAMPs) are a fraction of AMPs that target specific bacteria and maintain the balance of the healthy microbiota of a host. We reported a STAMP Peptide K (former name: peptide 13) for E. coli. The aim of this study was to effectively produce peptide K using methylotrophic yeast Pichia pastoris. Methods: Three inserts (sequence of peptide K (K), two copies of peptide K fused with 2A sequence (KTK), and two copies of peptide K fused with 2A and an extra α mating factor (KTAK)) were designed to investigate the effect of the number of repeats and the trafficking of peptide on the yield. Results: The yield from KTK was the highest-more than two-fold higher compared with K-implying the role of the 2A sequence in heterologous peptide expression apart from the co-translation. Then, the fermentation condition for KTK was optimized. The optimized yield of KTK was 6.67 mg/mL, suggesting the efficiency of the expression system. Selectivity, antibacterial activity, biocompatibility, and the stability of the fermentation product were equivalent to the chemically synthesized peptide. The actional mechanism of the fermentation product included membrane permeabilization and ROS induction. Conclusions: Together, our work provided a new perspective to augment the yield of the antimicrobial peptide in the microbial system, building a technological foundation for their large-scale production and expanding the market application of AMPs.

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.

Antimicrobial Resistance Gene Carriage is not Associated with Uremic Toxin Levels in Chronic Kidney Disease Patients

In chronic kidney disease (CKD), uremic toxin molecules build up and risk of infection increase overtime, making the presence of antimicrobial resistant (AMR) bacteria in the gut more problematic with advancing disease. This study assessed if serum levels of uremic toxins and gut carriage of AMR genes are correlated in individuals with CKD. Whole metagenomic sequencing of stool samples and measured levels of 4 uremic toxins from 21 individuals with CKD were obtained. Multivariable, multivariate linear regression was performed with total abundance of AMR genes and abundance of specific drug classes of AMR genes as outcome variables and serum levels of four uremic toxins as predictor variables. Beta diversity differences of AMR genes were visualized using non-metric multidimensional scaling (NMDS) based on robust Aitchison distances and tested using PERMANOVA. There were no significant associations between uremic toxin levels and AMR gene abundance, or with any of the drug classes of AMR genes. There were no significant differences in beta diversity of AMR genes. These null findings suggest that increased uremic toxin levels are not associated with an increase in AMR carriage, and therefore uremia does not appear to be a direct cause of increased resistant bacteria in patients with more severe CKD.

Assessment of community-acquired urinary tract infections treatment in the emergency department: a retrospective study.

Urinary tract infection (UTI) is one of the most common medical complaints in the emergency department (ED). The aim of this study was to assess the real indication of an initial broad-spectrum treatment administered in the ED for hospitalized patients with a diagnosis of community-acquired UTI (CAUTI). This is a monocentric observational retrospective study conducted in the ED of one of the largest tertiary care centers in Lebanon, on a two-year period, including adult patients admitted to the hospital for a CAUTI. The primary outcome was to evaluate the need of downgrading empirical antibiotherapy started in the ED. Secondary outcomes included a description of CAUTIs characteristics: prevalence and risk factors for (extended spectrum beta lactamases) ESBL-related infection, complicated and uncomplicated UTIs, empirical and targeted treatment, and finally the rate of adherence to local guidelines. The most isolated strains on urine cultures were gram negative bacilli (GNB) with 29.1% producing ESBL; 69.4% of patients received an ESBL-targeting empirical treatment in the ED, in agreement with local guidelines, 46% of which needed a downgrade. Amikacin adjunction was only indicated in 42.8% of the cases. Patients who received antibiotics in the last 6 months had a 2.36 times higher risk of developing an ESBL-related infection. This study showed a high adherence rate to local recommendations suggesting the use of empirical ESBL-targeting antibiotherapy even in uncomplicated UTIs. However, the frequent need of de-escalation highlights the importance of establishing an efficient multi-drug resistant (MDR) bacteria surveillance system in the community in order to elaborate a stewardship program with more solid local guidelines.