Broad-spectrum Antimicrobials Research Articles

Low rates of complications and β-lactam resistance in viridans group streptococci bloodstream infection among cancer patients receiving chemotherapy.

Viridans group streptococci (VGS) bloodstream infection (BSI) frequently occurs in cancer patients receiving chemotherapy, and is associated with infective endocarditis (IE) in up to 20% of cases in the general population. In cancer patients receiving chemotherapy with VGS BSI, we aimed to: (i) determine the incidence of infective complications including IE, (ii) assess the utility of echocardiography in this patient population, (iii) determine the duration and type of antimicrobial therapy received for monomicrobial infections, and (iv) determine the evolution of antimicrobial resistance. VGS BSIs (excluding Streptococcus pneumoniae and Streptococcus pseudopneumoniae) in cancer patients receiving chemotherapy were identified from a statewide public pathology database between 2013 and 2022 at our tertiary centre. Medical records were accessed for clinical, microbiological and radiological data. Of 581 patient episodes screened, 183 episodes involving 171 patients met inclusion criteria. Of these, 51% were bone marrow transplantation (BMT) patients, 40% were non-BMT haematology patients, and 8% were solid organ malignancy patients. The median age was 55 years, and 96% were neutropenic at the time of blood culture collection. A transthoracic echocardiogram was performed for 71% of episodes, and one patient met modified Duke's criteria for definite IE, although this diagnosis was not suspected on clinical grounds. Other complications were uncommon. Benzylpenicillin resistance was rare (2.9%) and did not change over time. Most episodes (75%) were treated with piperacillin/tazobactam. For monomicrobial BSIs, the median antibiotic duration was 5 days (IQR 2-7) post-neutropenia resolution. Infective complications and antimicrobial resistance are rare in cancer patients with VGS BSI. This may provide a safe opportunity to limit both investigations (e.g. echocardiogram) and prolonged exposure to broad-spectrum antimicrobials.

Efficient removal of sulfamethazine and sulphanilamide using modified amberlite with metal organic framework based copper and cobalt

The presence of antimicrobial sulfa chemicals in water is becoming a more serious problem and action must be taken to create an effective decontamination process for wastewater treatment. In this way, current thinking has focused on removing sulfa drugs as broad-spectrum antimicrobials from water by metal organic framework ((Cu&Co)-benzenetricarboxylate, M−BTC) bound within the amberlite polymer. Here, M(Cu&Co)-BTC is synthesized and incorporated within amberlite polymer in a single step. Moreover, the adsorptive capacities of the various sulfa drugs (sulfamethazine and sulphanilamide) were investigated using M−BTC@amberlite compounds for the first time. The adsorption efficiency of the sulfa drugs was monitored (higher performance for sulfamethazine rather than sulfanilamide), and the adsorption uptake was reached 99 % within about 60 min. The adsorption isotherms were best fitted using the Langmuir and pseudo-second-order model, individually. The greatest potencies for Cu-BTC@amberlite and Co-BTC@amberlite were 205 and 306 mg/g for sulfamethazine and 326 and 488 mg/g for sulfanilamide, separately. By incorporating Co-BTC within amberlite, the absorption capacity of sulfamethazine and sulfanilamide was extended by 1.72 and 1.83 times, respectively, while incorporation of Cu-BTC within amberlite, the adsorption capacity of sulfamethazine and sulfanilamide was extended by 2.56 and 2.73 times, respectively. The attached MOFs with polymer showed very high reusability and their efficacy in uptake of sulfamethazine and sulfanilamide diminished by 14.8–15.9 % and 11.3–12.7 %, separately, after five sequential adsorption cycles. Hence, in agreement with the adsorption result, a conceivable tool is proposed. The sulfa drug adsorption performed on a range of BTC-MOFs with diverse physicochemical properties and point-by-point characterization confirmed that the highest adsorption capacity of MOFs is achieved through bi-bi interaction; H-bonding between NH sites of sulfa drug particles and O sites of carboxyl units within MOFs. In scale-up, M−BTC@amberlite has demonstrated remarkable reusability, which is enticing for potential applications in the adsorption of sulfa drugs from wastewater

The combination of taurine and cepharanthine as a composite antibacterial agent

The indiscriminate application of diverse broad-spectrum antimicrobials has escalated nosocomial infections into a critical global public health quandary. Currently, traditional antibiotics' efficacy against these infections becomes limited, necessitating a concerted pursuit of more efficacious antimicrobial agents. It is noteworthy that taurine (tau) and cepharanthine (cep) are both biologically active compounds, with taurine constituting a vital nutrient to human health and cepharanthine exhibiting certain antibacterial attributes. However, while cepharanthine displays intrinsic antibacterial features, its monomeric utility is constrained. This study thus investigated the formulation process of merging taurine with cepharanthine, and rigorously assessed the antimicrobial potential of the taurine-cepharanthine complex (denoted as [cep][tau]). The outcomes indicated that this complex, [cep][tau], exhibited antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae, which was on par with the efficacy of cepharanthine on its own. This observation implies that taurine did not antagonize the antibacterial potency of cepharanthine, offering novel avenues for the development of innovative pharmaceuticals targeting hospital-acquired infections.

Investigating the Effectiveness of Ceragenins against Acinetobacter baumannii to Develop New Antimicrobial and Anti-Adhesive Strategies.

A growing body of experimental data indicates that ceragenins (CSAs), which mimic the physicochemical properties of the host's cationic antimicrobial peptide, hold promise for the development of a new group of broad-spectrum antimicrobials. Here, using a set of in vivo experiments, we assessed the potential of ceragenins in the eradication of an important etiological agent of nosocomial infections, Acinetobacter baumannii. Assessment of the bactericidal effect of ceragenins CSA-13, CSA-44, and CSA-131 on clinical isolates of A. baumannii (n = 65) and their effectiveness against bacterial cells embedded in the biofilm matrix after biofilm growth on abiotic surfaces showed a strong bactericidal effect of the tested molecules regardless of bacterial growth pattern. AFM assessment of bacterial cell topography, bacterial cell stiffness, and adhesion showed significant membrane breakdown and rheological changes, indicating the ability of ceragenins to target surface structures of A. baumannii cells. In the cell culture of A549 lung epithelial cells, ceragenin CSA-13 had the ability to inhibit bacterial adhesion to host cells, suggesting that it interferes with the mechanism of bacterial cell invasion. These findings highlight the potential of ceragenins as therapeutic agents in the development of antimicrobial strategies against bacterial infections caused by A. baumannii.

The impact of meropenem shortage and post-prescription review and feedback on broad-spectrum antimicrobial use: An interrupted time-series analysis

Meropenem (MEPM) holds significance in treating severe infections and drug-resistant bacteria. There are concerns that antimicrobial shortages may lead to the use of alternative antimicrobials that are less effective and safer. We have responded to the MEPM shortage with post-prescription monitoring and feedback (PPRF) with no restrictions on MEPM initiation. We aimed to assess the impact of the MEPM shortage and the PPRF on broad-spectrum antimicrobial use and mortality. This retrospective study was conducted in a single hospital in Japan. The period from October 2021 to August 2022 was defined as the period before the MEPM shortage, and the period from September 2022 to March 2023 was defined as the period during the MEPM shortage. To support the appropriate use of antimicrobials during MEPM shortages, the antimicrobial stewardship team (AST) developed a list of alternatives to MEPM. An interrupted time series analysis was used to assess changes in use and mortality among patients receiving broad-spectrum antimicrobials over the study period. The shortage of MEPM and PPRF temporarily increased the use of alternative cefepime; however, the subsequent change in days of therapy and days of coverage of broad-spectrum antimicrobials suggests a decrease in the use of these antimicrobials. Despite these shifts, the mortality rates remained stable, suggesting that the response to the shortage did not adversely affect treatment outcomes. In the context of antimicrobial shortages, AST support plays an important role in enabling physicians to make optimal use of antimicrobials.

Systematic review on the safety of the use of quinolones in the pediatric population

Background: The safety of fluoroquinolones in the pediatric population has been a matter of concern due to the potential for adverse effects such as growth cartilage toxicity. Despite their broad antimicrobial spectrum and efficacy, the prescription of fluoroquinolones in children and adolescents is limited by the risk of arthralgias and other side effects. This study aims to evaluate the safety of fluoroquinolones in pediatric patients and the impact of regulatory actions on their prescription. Material and methods: A systematic review of studies investigating the safety of fluoroquinolones in the pediatric population was conducted. Studies that met specific inclusion criteria were selected, and relevant information on the decrease in fluoroquinolone prescriptions and their adverse effects was extracted. Results: In the study on the safety and tolerability of quinolones in the pediatric population, 22% (199/904) of patients experienced adverse events following treatment with quinolones. Gastrointestinal disorders, such as nausea and diarrhea, were the most frequent, affecting 12% (108/904) of patients. This was followed by skin rashes and effects on the central nervous system, at 5% (45/904) and 3% (27/904) respectively. Moxifloxacin demonstrated good tolerability across all age cohorts, without significant joint or neuropathic adverse findings. Specific safety studies of moxifloxacin confirmed its safety, showing no significant differences in safety variables compared to other antibiotics. Conclusion: It is crucial to continue monitoring the safety of fluoroquinolones in the pediatric population to ensure an adequate balance between the benefits and risks of their use.

Assessment of Postbiotic, Mundticin-like Substance EM 41/3 Application in Broiler Rabbits

Nowadays, the use of probiotics, postbiotics, parabiotics and other beneficial natural substances dominate health status sustainability in animals. Mundticin-like substance EM 41/3 (MLS) is a thermo-stable substance of proteinaceous character—a bacteriocin (postbiotic) with a broad antimicrobial (inhibitory) spectrum produced by the horse-derived strain Enterococcus mundtii EM 41/3. The aim of this study was to find if this new one bacteriocin can have an effect and/or a similar effect in rabbits as was achieved previously by using enterocins detected and characterized in our laboratory. In addition, these tests have been conducted to secure the health of rabbits as food-derived animals. Moreover, the aim of this study was also to test the effect of MLS EM 41/3 in broiler rabbits as an animal model before its use in horses. The parameters tested were analyzed by validated methods. Administration of MLS EM 41/3 lead to a significant increase in the non-specific immunity parameter (phagocytic activity, p < 0.05), while microbiota in feces, caecum and appendix were not negatively influenced. However, the total enterococcal count was significantly increased in the EG compared to the CG (p < 0.001). Application of MLS EM 41/3 did not have a negative impact on blood biochemistry. No oxidative stress was noted. However, higher growth parameters were noted and also hydrolytic activity was increased after MLS EM 41/3 application. Finally, to check physico-chemical parameters, no negative influence on rabbit meat quality was noted. Postbiotic MLS EM 41/3 administration seems to be a contributing factor in the feeding strategy for animal health status sustainability.

Emodin Alcohols: Design, Synthesis, Biological Evaluation and Multitargeting Studies with DNA, RNA, and HSA.

A series of novel emodin alcohols were designed and prepared in an effort to overcome the increasing microorganism resistance. Novel emodin alcohols were prepared from commercial emodin and different nitrogen-containing heterocycles via different synthetic strategies, such as O-alkylation and N-alkylation. The antimicrobial activity of synthesized emodin compounds was evaluated in vitro by a two-fold serial dilution technique. The interaction of emodin compound 3d with biomolecule was researched using UV-vis spectroscopic method and fluorescence spectroscopy. Emodin compound 3d containing 2-methyl-5-nitro imidazole ring showed relatively good antimicrobial activity. Notably, it exhibited equivalent activity against S. aureus in comparison to the reference drug norfloxacin (MIC = 4 μg/mL). The combination of strong active compound 3d with reference drugs showed better antimicrobial activity with less dosage and a broader antimicrobial spectrum than their separate use. Further research displayed that emodin compound 3d could intercalate into S. aureus DNA to form the 3d-DNA complex, which might correlate with the inhibitory activity. The hydrogen bonds were found between S. aureus DNA gyrase and strong active compound 3d during the docking research, which were in accordance with the spectral experiment results. The interaction with yeast RNA of compound 3d could also form a complex via hydrogen bonds. The hydrogen bonds were found to play a major role in the transportation of emodin compound 3d by human serum albumin (HSA), as confirmed by molecular simulation. This work provides a promising starting point to optimize the structures of emodin derivatives as potent antimicrobial agents.

Activity of Cannabidiol on Ex Vivo Amino Acid Fermentation by Bovine Rumen Microbiota

Amino-acid-fermenting bacteria are wasteful organisms within the rumens of beef cattle that remove dietary amino nitrogen by producing ammonia, which is then excreted renally. There are currently no on-label uses for the control of this microbial guild, but off-label use of broad-spectrum antimicrobials has shown efficacy, which contributes to antimicrobial resistance. Plant-derived antimicrobials supplemented into the diets of cattle may offer worthwhile alternatives. This study sought to investigate the role of cannabidiol (CBD) as a terpenophenolic antimicrobial. Ex vivo cell suspensions were harvested from the rumen fluid of Angus × Holstein steers in non-selective media with amino acid substrates. The suspensions were treated with five concentrations of CBD (860 μg mL−1–0.086 μg mL−1) and incubated (24 h), after which ammonia production and viable number of cells per substrate and treatment were measured. The data demonstrated a ~10–15 mM reduction in ammonia produced at the highest concentration of CBD and negligible changes in the viable number of amino-acid-fermenting bacteria. CBD does not appear to be a biologically or economically viable terpenophenolic candidate for the control of amino acid fermentation in beef cattle.

Efficacy of empirical Ciprofloxacin or Cefixime plus Metronidazole therapy for the treatment of liver abscess: a randomized control clinical trial

Liver abscess is a potentially life-threatening medical emergency. Prompt empirical antimicrobial with or without percutaneous aspiration or drainage is therapeutic. The rational for using empirical intravenous broad-spectrum antimicrobials upfront instead of oral Fluoroquinolone or Cephalosporin is contentious. In this double blind randomized control clinical trial 69 participants received Ciprofloxacin (500 mg q 12 hourly) and 71 participants received Cefixime (200 mg q 12 hourly) orally for 2 weeks. Both the group received oral Metronidazole (800 mg q 8 hourly) for 2 weeks and percutaneous drainage or aspiration of the abscess was done as per indication and followed-up for 8 weeks. Out of 140 participants, 89.3% (N = 125) achieved clinical cure, 59 (85.5%) in Ciprofloxacin group and 66 (93%) in Cefixime group (p = 0.154). Mean duration of antimicrobial therapy was 16.2 ± 4.3 days, 15.1 ± 4.5 days in Ciprofloxacin group and 16.0 ± 4.2 days in Cefixime group (p = 0.223). Total 15 (10.7%) participants had treatment failure, 10 (14.5%) in Ciprofloxacin group and 5 (7.0%) in Cefixime group (p = 0.154). The most common reason for treatment failure was need of prolong (> 4 weeks) antimicrobial therapy due to persistent hepatic collection requiring drainage, which was significantly (p = 0.036) higher in Ciprofloxacin (14.5%, N = 10) group, compared to the Cefixime (4.2%, N = 3) group. In conclusion, both, the Ciprofloxacin or Cefixime plus Metronidazole for duration of 2–3 weeks were efficacious as empirical oral antimicrobial regimen along with prompt percutaneous drainage or aspiration for the treatment of uncomplicated liver abscess with similar efficacy. Oral Cefixime was better than Ciprofloxacin in term of lesser chance of treatment failure due to persistent collection which is required to be investigated further in larger clinical trial.Trial registration: clinicaltrials.gov PRS ID: NCT03969758, 31/05/2019.

Impact of timing of antimicrobial therapy on outcome and mortality in severe sepsis and septic shock

Even though new antimicrobial treatments have been available for over 60 years, the fatality rate from septic shock has not decreased. Evolutionary pressure on microbial pathogens has, as expected, led to selection towards resistant species as a consequence of the creation of ever more broad-spectrum and strong antimicrobials. The ineffectiveness of antibiotic treatment of septic shock un the decades that followed may have been a result of this phenomena. The treatment of septic shock has traditionally focused on resuscitative measures. The management of these serious illnesses has not prioritised the prompt provision of effective antibiotic treatment.

Point-of-Care Method T2Bacteria®Panel Enables a More Sensitive and Rapid Diagnosis of Bacterial Blood Stream Infections and a Shorter Time until Targeted Therapy than Blood Culture.

Rapid diagnosis and identification of pathogens are pivotal for appropriate therapy of blood stream infections. The T2Bacteria®Panel, a culture-independent assay for the detection of Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa in blood, was evaluated under real-world conditions as a point-of-care method including patients admitted to the internal medicine ward due to suspected blood stream infection. Patients were assigned to two groups (standard of care-SOC vs. T2). In the SOC group 2 × 2 blood culture samples were collected, in the T2 group the T2Bacteria®Panel was performed additionally for pathogen identification. A total of 94 patients were included. Pathogens were detected in 19 of 50 patients (38%) in the T2 group compared to 16 of 44 patients (36.4%) in the SOC group. The median time until pathogen detection was significantly shorter in the T2 group (4.5 h vs. 60 h, p < 0.001), as well as the time until targeted therapy (antibiotic with the narrowest spectrum and maximal effectiveness) (6.4 h vs. 42.2 h, p = 0.043). The implementation of the T2Bacteria®Panel for patients with sepsis leads to an earlier targeted antimicrobial therapy resulting in earlier sufficient treatment and decreased excessive usage of broad-spectrum antimicrobials.

Comparison of fidaxomicin, thuricin CD, vancomycin and nisin highlights the narrow spectrum nature of thuricin CD

ABSTRACT Vancomycin and metronidazole are commonly used treatments for Clostridioides difficile infection (CDI). However, these antibiotics have been associated with high levels of relapse in patients. Fidaxomicin is a new treatment for CDI that is described as a narrow spectrum antibiotic that is minimally active on the commensal bacteria of the gut microbiome. The aim of this study was to compare the effect of fidaxomicin on the human gut microbiome with a number of narrow (thuricin CD) and broad spectrum (vancomycin and nisin) antimicrobials. The spectrum of activity of each antimicrobial was tested against 47 bacterial strains by well-diffusion assay. Minimum inhibitory concentrations (MICs) were calculated against a select number of these strains. Further, a pooled fecal slurry of 6 donors was prepared and incubated for 24 h with 100 µM of each antimicrobial in a mini-fermentation system together with a no-treatment control. Fidaxomicin, vancomycin, and nisin were active against most gram positive bacteria tested in vitro, although fidaxomicin and vancomycin produced larger zones of inhibition compared to nisin. In contrast, the antimicrobial activity of thuricin CD was specific to C. difficile and some Bacillus spp. The MICs showed similar results. Thuricin CD exhibited low MICs (<3.1 µg/mL) for C. difficile and Bacillus firmus, whereas fidaxomicin, vancomycin, and nisin demonstrated lower MICs for all other strains tested when compared to thuricin CD. The narrow spectrum of thuricin CD was also observed in the gut model system. We conclude that the spectrum of activity of fidaxomicin is comparable to that of the broad-spectrum antibiotic vancomycin in vitro and the broad spectrum bacteriocin nisin in a complex community.

How Should We Manage Antimicrobial Resistance in Resource-Limited Settings?

Patients living in low- and middle-income countries (LMICs) shoulder the greatest burden of infections caused by antimicrobial-resistant pathogens. Speedy access to appropriate broad-spectrum antimicrobials significantly improves health outcomes and reduces transmission of antimicrobial-resistant pathogens, but persons living in LMICs have compromised access to these antimicrobials. This article considers how inequities in microbiology diagnostics, antimicrobial access, and antimicrobial affordability influence outcomes for patients infected with antimicrobial-resistant pathogens who live in resource-limited settings.

Assessment of antimicrobial prescribing patterns, guidelines compliance, and appropriateness of antimicrobial prescribing in surgical-practice units: point prevalence survey in Malaysian teaching hospitals.

Objectives: This study sought to investigate the quality of antimicrobial prescribing among adult surgical inpatients besides exploring the determinants of non-compliance and inappropriate prescribing to inform stewardship activities. Methods: A cross-sectional point prevalence study employing Hospital National Antimicrobial Prescribing Survey (Hospital NAPS) was conducted in April 2019 at two teaching hospitals in Malaysia. Results: Among 566 surgical inpatients, 44.2% were receiving at least one antimicrobial, for a total of 339 prescriptions. Antimicrobials belonging to the World Health Organization's Watch group were observed in 57.8% of cases. Both hospitals exhibited similar types of antimicrobial treatments prescribed and administration routes. A significant difference in antimicrobial choice was observed between hospitals (p < 0.001). Hospital with electronic prescribing demonstrated better documentation practice (p < 0.001). Guidelines compliance, 32.8% (p = 0.952) and appropriateness, 55.2% (p = 0.561) did not significantly differ. The major contributors of inappropriateness were incorrect duration, (15%) and unnecessary broad-spectrum coverage, (15.6%). Non-compliance and inappropriate prescribing were found to be 2 to 4 times significantly higher with antimicrobial prophylaxis prescription compared to empirical therapy. Conclusion: Antimicrobial stewardship efforts to improve appropriate surgical prescribing are essential. These initiatives should prioritize surgical prophylaxis prescribing, focusing on reducing unnecessarily prolonged use and broad-spectrum antimicrobials, raising awareness among prescribers and promoting proper documentation.

Wide use of broad-spectrum antibiotics in very low birth weight infants with spontaneous focal intestinal perforation-is it really justified?

Very low birth weight (VLBW) infants are at a risk of spontaneous focal intestinal perforation (FIP). Treatment includes supportive care, antibiotics, and drainage with/without surgery. Broad-spectrum antibiotic agents like carbapenems are applied frequently, although their use is not well-supported by the limited evidence of causal pathogens. We hypothesize that the use of carbapenems may not be necessary in VLBW infants with FIP. Our primary objective was to evaluate the antimicrobial use in VLBW infants with FIP in a cohort of the German Neonatal Network (GNN). The secondary objective was to characterize a subset in detail as a benchmark for future targets of stewardship. Data on VLBW infants with FIP was collected prospectively within the GNN, a collaboration of 68 neonatal intensive care units (NICU). With regards to the primary objective, patient characteristics and antimicrobial treatment were extracted from the predefined GNN database. To address our secondary objective, an additional on-site assessment of laboratory and microbiological culture results were performed. In the GNN cohort, 613/21,646 enrolled infants (2.8%) developed FIP requiring surgery. They were frequently treated with carbapenems (500/613 (81.6%)) and vancomycin (497/613 (81.1%)). In a subset of 124 VLBW infants, 77 (72.6%) had proof of gram-positive bacteria in the abdominal cavity, coagulase-negative staphylococci (CoNS) predominantly. Despite the low prevalence of gram-negative bacteria (n = 6 (4.8%)), the combination of meropenem and vancomycin was prescribed most frequently (n = 96 (78.0%)). The use of carbapenems as broad-spectrum antimicrobials agents might not be justified in most VLBW infants with FIP. Knowledge on the development of the neonatal gut microbiota, local resistance patterns and individual microbiological findings should be taken into consideration when implementing antimicrobial stewardship programs (ASPs).

Secondary Intention Healing After Debridement for Bilateral Periorbital Necrotizing Fasciitis.

A 75-year-old male with a history of poorly controlled diabetes, hypertension, coronary artery disease, chronic obstructive pulmonary disease, and obesity presented with severe bilateral periorbital edema with necrosis and purulent discharge. Although hemodynamically stable, laboratory markers indicated systemic toxicity. Imaging showed bilateral periorbital edema extending into the frontal scalp, temporal fossa, and right orbit. Suspected to have necrotizing fasciitis, the patient underwent urgent debridement of bilateral upper and lower eyelids and was found to have postseptal extension of necrosis into the right orbit. During his hospitalization, he was treated with broad-spectrum antimicrobials and underwent a second surgery for exploration and debridement. The patient was lost to follow-up and found to have healed by secondary intention without any surgical reconstruction. Our case demonstrates not only a rare case of necrotizing fasciitis involving all 4 eyelids, but also an exceptional cosmetic and functional result after secondary intention healing.

Knowledge, attitudes, and practices on antimicrobial use and antimicrobial resistance among poultry practitioner veterinarians.

Antimicrobial resistance (AMR) poses a serious global threat to human and animal health. In the context of antimicrobial usage (AMU) in livestock production, veterinarians are key stakeholders. However, there is a lack of comprehensive situational analysis regarding the current Knowledge, Attitudes, and Practices (KAP) among veterinarians concerning AMU and AMR in poultry production in Nepal. The primary objective of this study was to evaluate the situation of AMU and KAP regarding AMU and AMR of among poultry practitioner veterinarians in Nepal. A total of 327 respondents from 56 districts across seven provinces participated. Demographic information and AMU situation were collected and analyzed using descriptive statistics, and factors affecting KAP on AMU and AMR were performed using logistic regression analysis. Nearly half of veterinarians (49.2%) were from Bagmati, followed by Lumbini (16.5%) and Gandaki (8.9%) provinces. Most of the respondents (85.0%) identified themselves as male with a mean age of 31.9 ± 7.8 years, with a range of 24-74 years. A large proportion of veterinarians held a master's degree (43.8%). Regarding reasons for AMR, 51.1% of them attributed it to the irrational use of antimicrobials. Other identified reasons for AMR, including over-the-counter sales (27.8%), low-dose administration (12.3%), and low-quality antimicrobials (6.7%). Based on antibiotic prescription rates, most veterinarians (50.8%) prescribed antimicrobials at a rate of 20-40%, while 25.9% prescribed at a rate of less than 20.0 and 18.9% at a rate of 40-60%. Approximately 89.0% of veterinarians agreed that vaccination could reduce the use of antimicrobials in poultry, and 75.6% preferred narrow-spectrum antimicrobials than broad-spectrum antimicrobials. A combination of broad-spectrum antimicrobials such as colistin with amoxicillin, gentamicin, tylosin, and tetracycline was commonly used in poultry production. In logistic regression analysis, it was observed that veterinarians aged 45-60 years demonstrated significantly higher levels of knowledge concerning AMU and AMR (p = 0.02) compared to those in the 24-30 age group. This study indicates that the need for robust regulatory mechanisms in veterinary drug administration and increased awareness among veterinarians to address the AMR issue livestock production.

Engineering a nanoantibiotic system displaying dual mechanism of action

In recent decades, peptide amphiphiles (PAs) have established themselves as promising self-assembling bioinspired materials in a wide range of medical fields. Herein, we report a dual-therapeutic system constituted by an antimicrobial PA and a cylindrical protease inhibitor (LJC) to achieve broad antimicrobial spectrum and to enhance therapeutic efficacy. We studied two strategies: PA-LJC nanostructures (Encapsulation) and PA nanostructures + free LJC (Combination). Computational modeling using a molecular theory for amphiphile self-assembly captures and explains the morphology of PA-LJC nanostructures and the location of encapsulated LJC in agreement with transmission electron microscopy and two-dimensional (2D) NMR observations. The morphology and release profile of PA-LJC assemblies are strongly correlated to the PA:LJC ratio: high LJC loading induces an initial burst release. We then evaluated the antimicrobial activity of our nanosystems toward gram-positive and gram-negative bacteria. We found that the Combination broadens the spectrum of LJC, reduces the therapeutic concentrations of both agents, and is not impacted by the inoculum effect. Further, the Encapsulation provides additional benefits including bypassing water solubility limitations of LJC and modulating the release of this molecule. The different properties of PA-LJC nanostructures results in different killing profiles, and reduced cytotoxicity and hemolytic activity. Meanwhile, details in membrane alterations caused by each strategy were revealed by various microscopy and fluorescent techniques. Last, in vivo studies in larvae treated by the Encapsulation strategy showed better antimicrobial efficacy than polymyxin B. Collectively, this study established a multifunctional platform using a versatile PA to act as an antibiotic, membrane-penetrating assistant, and slow-release delivery vehicle.

Antimicrobial stewardship and molecular diagnostics: a symbiotic approach to combating resistance in the ED and ICU.

This review aims to evaluate the incorporation of rapid molecular diagnostics (RMD) in antimicrobial stewardship programs (ASPs) in the management of patients in the emergency department (ED) and intensive care unit (ICU), highlighting a shift from conventional microbiological diagnostic tests to RMD strategies to optimize antimicrobial use and improve patient outcomes. Recent advances in RMD have demonstrated the superior accuracy of RMD in identifying pathogens, combined with shorter turnaround times. RMD allows speeding up of antimicrobial decision making in the ED and facilitates faster escalation when empirical therapy was inappropriate, as well as more efficient de-escalation of empirical therapy later in the course of the treatment. Implementation of RMD however may be challenging. RMD hold great value in simplifying patient management and mitigating antimicrobial exposure, particularly in settings with high levels of antimicrobial resistance where the use of broad-spectrum antimicrobials is high. While the impact on the use of antimicrobials is significant, the impact on patient outcomes is not yet clear. Successful integration of RMD in clinical decision making in the ED and ICU requires a team approach and continued education, and its use should be adapted to the local epidemiology and infrastructure.