Myrtus communis leaves: source of bio - actives, traditional use, their biological properties, and prospects / Hojas de Myrtus communis: fuente de bioactivos, uso tradicional, sus propiedades biológicas y perspectivas

Myrtus communis L., commonly known as true myrtle, is a medicinal plant native to the Mediterranean area. Since ancient times, the inhabitant s of this area have been using it for its cultural and medicinal properties. Because of the vast diversity of biomolecules in its aerial parts, it exhibits several biological properties, including antioxidant, antimicrobial, and anticancer properties. This review retrospect the research on the source, biological activities with empirical evidence, chemical composition, applications, and cellular targets of extracts and essential oils obtained from M. communis leaves, which provides a perspective for further studies on the applications and formulations of extract and EO of M. communis leaves. The efficacy of constituents' individually, in association with other bioactive constituents, or in combination with available commercial drugs would provide insights in to the development of these bio - actives as future drugs and their evolving future potential applications in the pharmaceutical, food, and aroma industries.

Myrtus communis L., comúnmente conocido como arrayán verdadero, es una planta medicinal originaria de la zona mediterránea. Desde la antigüedad, los habitantes de esta zona lo utilizan por sus propiedades culturales y medicinales. Debido a la gran div ersidad de biomoléculas en sus partes aéreas, exhibe varias propiedades biológicas, incluidas propiedades antioxidantes, antimicrobianas y anticancerígenas. Esta revisión retrospectiva de la investigación sobre la fuente, las actividades biológicas con evi dencia empírica, la composición química, las aplicaciones y los objetivos celulares de los extractos y aceites esenciales obtenidos de las hojas de M. communis , lo que brinda una perspectiva para futuros estudios sobre las aplicaciones y formulaciones de l os extractos y EO de M. communis . La eficacia de los componentes individualmente, en asociación con otros componentes bioactivos o en combinación con medicamentos comerciales disponibles proporcionaría información sobre el desarrollo de estos bioactivos co mo medicamentos futuros y sus futuras aplicaciones potenciales en las industrias farmacéutica, alimentaria y aromática

Chemical composition, antioxidant and antimicrobial activities of essential oil from the aerial parts of Chuquiraga arcuataHarling grown in the highlands of Ecuador / Composición química, actividades antioxidantes y antimicrobianas del aceite esencial de las partes aéreas de Chuquiraga arcuataHarling cultivado en las tierras altas del Ecuador

Thechemical composition, antioxidant and antimicrobial activities of the essential oil from aerial parts (leaves and flowers) of Chuquiraga arcuataHarling grown in the Ecuadorian Andes were studied. One hundred and twenty-six compounds were identified in the essential oil. Monoterpene hydrocarbons (45.8%) and oxygenated monoterpenes (44.1%) had the major percentages. The most abundant compounds were camphor (21.6%), myrcene (19.5%), and 1,8-cineole (13.4%). Antioxidant activity was examined using DPPH, ABTS,and FRAP assays. The essential oil had a moderate scavenging effect and reduction of ferric ion capacity through FRAP assay. Antimicrobial activity of the essential oil was observed against four pathogenic bacteria and a fungus. The essential oil exhibited activity against all microorganism strains under test, particularly against Candida albicansand Staphylococcus aureuswith MICs of 2.43-12.10 µg/mL.

Se estudió la composición química, actividades antioxidantes y antimicrobianas del aceite esencial procedente de las partes aérea (hojas y flores) de Chuquiraga arcuataHarling cultivadas en los Andes ecuatorianos. Se identificaron 126 compuestos en el aceite esencial. Los hidrocarburos monoterpénicos (45,8%) y los monoterpenos oxigenados (44,1%) tuvieron el mayor porcentaje. Los compuestos más abundantes fueron alcanfor (21,6%), mirceno (19,5%) y 1,8-cineol (13,4%). La actividadantioxidante se examinó mediante ensayos DPPH, ABTS y FRAP. El aceite esencial tuvo un efecto eliminador moderado y una reducción de la capacidad de iones férricos mediante el ensayo FRAP. Se observó actividad antimicrobiana del aceite esencial contra cuatro bacterias y un hongo patógenos. El aceite esencial mostró actividad contra todas las cepas de microorganismos bajo prueba, particularmente contra Candida albicansy Staphylococcus aureuscon CMI de 2,43-12,10 µg/mL.

Past, present and future of Psoralea glandulosa Linn, Chilean medicinal plant, an inexhaustible resource: a literature review / Pasado, presente y futuro de Psoralea glandulosa Linn, planta medicinal chilena fuente inagotable de recursos: una revisión de la literatura

Culén is the popular term used in Chile for the only endemic species of the Fabaceae family, Psoralea glandulosaLinn. It is one of the most widely used medicinal plants in Chile and in some regions of South America, not only as a home remedy, but also recommended by medicine and widely used in the gastronomic industry. Many properties are known, supported by biological tests both in vitroand in vivo. Because it is so highly appreciated, it is included in the book "Medicamentos HerbariosTradicionales" (Traditional Herbal Medicines) of the Chilean Ministry of Health. Given the great interest in this plant since time immemorial, this review contains information on its history, popular uses and scientific studies, for a better knowledge, management and sustainable care of this Chilean natural resource.

Culén es el término popular utilizado en Chile para la única especie endémica de la familia Fabaceae, Psoralea glandulosaLinn. Se trata de una de las plantas medicinales más utilizadas en Chile y en algunas regiones de Sudamérica, no solamente como remedio curativo casero, sino también recomendada por la medicina y con amplia utilización en la industria gastronómica. De ella se conocen un gran número propiedades avaladas por ensayos biológicos tanto in vitrocomo in vivo. Por ser tan apreciada, se encuentra incluida en el libro "Medicamentos Herbarios Tradicionales" del Ministerio de Salud de Chile. Dado el gran interés que despierta esta planta desde tiempos inmemoriales, se recoge en este capítulo la información sobre su historia, usos populares y estudios científicos, para un mejor conocimiento, manejo y cuidado de manera sustentable de este recurso natural chileno.

Clinical manifestations, antimicrobial resistance and genomic feature analysis of multidrug-resistant Elizabethkingia strains.

BACKGROUND: Elizabethkingia is emerging as an opportunistic pathogen in humans. The aim of this study was to investigate the clinical epidemiology, antimicrobial susceptibility, virulence factors, and genome features of Elizabethkingia spp. METHODS: Clinical data from 71 patients who were diagnosed with Elizabethkingia-induced pneumonia and bacteremia between August 2019 and September 2021 were analyzed. Whole-genome sequencing was performed on seven isolates, and the results were compared with a dataset of 83 available Elizabethkingia genomes. Genomic features, Kyoto Encyclopedia of Genes and Genomes (KEGG) results and clusters of orthologous groups (COGs) were analyzed. RESULTS: The mean age of the patients was 56.9 ± 20.7 years, and the in-hospital mortality rate was 29.6% (21/71). Elizabethkingia strains were obtained mainly from intensive care units (36.6%, 26/71) and emergency departments (32.4%, 23/71). The majority of the strains were isolated from respiratory tract specimens (85.9%, 61/71). All patients had a history of broad-spectrum antimicrobial exposure. Hospitalization for invasive mechanical ventilation or catheter insertion was found to be a risk factor for infection. The isolates displayed a high rate of resistance to cephalosporins and carbapenems, but all were susceptible to minocycline and colistin. Genomic analysis identified five ß-lactamase genes (blaGOB, blaBlaB, blaCME, blaOXA, and blaTEM) responsible for ß-lactam resistance and virulence genes involved in stress adaptation (ureB/G, katA/B, and clpP), adherence (groEL, tufA, and htpB) and immune modulation (gmd, tviB, cps4J, wbtIL, cap8E/D/G, and rfbC). Functional analysis of the COGs revealed that "metabolism" constituted the largest category within the core genome, while "information storage and processing" was predominant in both the accessory and unique genomes. The unique genes in our 7 strains were mostly enriched in KEGG pathways related to microRNAs in cancer, drug resistance (ß-lactam and vancomycin), ABC transporters, biological metabolism and biosynthesis, and nucleotide excision repair mechanisms. CONCLUSION: The Elizabethkingia genus exhibits multidrug resistance and carries carbapenemase genes. This study presents a comparative genomic analysis of Elizabethkingia, providing knowledge that facilitates a better understanding of this microorganism.

Genetic diversity of KPC-2-producing Klebsiella pneumoniae complex from aquatic ecosystems.

During the COVID-19 pandemic, the occurrence of carbapenem-resistant Klebsiella pneumoniae increased in human clinical settings worldwide. Impacted by this increase, international high-risk clones harboring carbapenemase-encoding genes have been circulating in different sources, including the environment. The blaKPC gene is the most commonly disseminated carbapenemase-encoding gene worldwide, whose transmission is carried out by different mobile genetic elements. In this study, blaKPC-2-positive Klebsiella pneumoniae complex strains were isolated from different anthropogenically affected aquatic ecosystems and characterized using phenotypic, molecular, and genomic methods. K. pneumoniae complex strains exhibited multidrug-resistant and extensively drug-resistant profiles, spotlighting the resistance to carbapenems, ceftazidime-avibactam, colistin, and tigecycline, which are recognized as last-line antimicrobial treatment options. Molecular analysis showed the presence of several antimicrobial resistance, virulence, and metal tolerance genes. In-depth analysis showed that the blaKPC-2 gene was associated with three different Tn4401 isoforms (i.e., Tn4401a, Tn4401b, and Tn4401i) and NTEKPC elements. Different plasmid replicons were detected and a conjugative IncN-pST15 plasmid harboring the blaKPC-2 gene associated with Tn4401i was highlighted. K. pneumoniae complex strains belonging to international high-risk (e.g., ST11 and ST340) and unusual clones (e.g., ST323, ST526, and ST4216) previously linked to clinical settings. In this context, some clones were reported for the first time in the environmental sector. Therefore, these findings evidence the occurrence of carbapenemase-producing K. pneumoniae complex strains in aquatic ecosystems and contribute to the monitoring of carbapenem resistance worldwide.

Design and synthesis of new quinazolinone derivatives: investigation of antimicrobial and biofilm inhibition effects.

New quinazolin-4-ones 9-32 were synthesized in an attempt to overcome the life-threatening antibiotic resistance phenomenon. The antimicrobial screening revealed that compounds 9, 15, 16, 18, 19, 20 and 29 are the most broad spectrum antimicrobial agents in this study with safe profile on human cell lines. Additionally, compounds 19 and 20 inhibited biofilm formation in Pseudomonas aeruginosa, which is regulated by quorum sensing system, at sub-minimum inhibitory concentrations (sub-MICs) with IC50 values 3.55 and 6.86 µM, respectively. By assessing other pseudomonal virulence factors suppression, it was found that compound 20 decreased cell surface hydrophobicity compromising bacterial cells adhesion, while both compounds 19 and 20 curtailed the exopolysaccharide production which constitutes the major component of the matrix binding biofilm components together. Also, at sub-MICs Pseudomonas cells twitching motility was impeded by compounds 19 and 20, a trait which augments the cells pathogenicity and invasion potential. Molecular docking study was performed to further evaluate the binding mode of candidates 19 and 20 as inhibitors of P. aeruginosa quorum sensing transcriptional regulator PqsR. The achieved results demonstrate that both compounds bear promising potential for discovering new anti-biofilm and quorum quenching agents against Pseudomonas aeruginosa without triggering resistance mechanisms as the normal bacterial life cycle is not disturbed.

A framework for leveraging network course-based undergraduate research experience (CURE) faculty to develop, validate, and administer an assessment instrument.

Over the last several years, nationally disseminated course-based undergraduate research experiences (CUREs) have emerged as an alternative to developing a novel CURE from scratch, but objective assessment of these multi-institution (network) CUREs across institutions is challenging due to differences in student populations, instructors, and fidelity of implementation. The time, money, and skills required to develop and validate a CURE-specific assessment instrument can be prohibitive. Here, we describe a co-design process for assessing a network CURE [the Prevalence of Antibiotic Resistance in the Environment (PARE)] that did not require support through external funding, was a relatively low time commitment for participating instructors, and resulted in a validated instrument that is usable across diverse PARE network institution types and implementation styles. Data collection efforts have involved over two dozen unique institutions, 42 course offerings, and over 1,300 pre-/post-matched assessment record data points. We demonstrated significant student learning gains but with small effect size in both content and science process skills after participation in the two laboratory sessions associated with the core PARE module. These results show promise for the efficacy of short-duration CUREs, an educational research area ripe for further investigation, and may support efforts to lower barriers for instructor adoption by leveraging a CURE network for developing and validating assessment tools.

A Quality Improvement Project to Increase Compliance With a Facility Protocol on Surgical Antimicrobial Prophylaxis.

Surgical site infections (SSIs) contribute to negative outcomes for patients and health care organizations. Compliance with clinical practice guidelines likely can help prevent SSIs. An interdisciplinary team at a regional referral center in Michigan sought to reduce SSIs by improving compliance with the facility's preoperative antibiotic selection, dosing, timing, and redosing protocol. The interventions for the quality improvement project included adding the preprocedural antibiotics and doses to the master OR schedule; holding an education session for all preoperative nurses, intraoperative nurses, and anesthesia professionals; and posting a reference guide in the preoperative and intraoperative areas. Compliance with the facility's protocol for antibiotic selection, dosing, and timing significantly improved. However, SSI rates and compliance with redosing recommendations did not change significantly. The team decided to add the antibiotic order information to the master OR schedule permanently. The team plans to consider providing education sessions on administering preprocedural antibiotics outside the OR.

When the solution becomes the problem: a review on antimicrobial resistance in dairy cattle.

Antibiotics' action, once a 'magic bullet', is now hindered by widespread microbial resistance, creating a global antimicrobial resistance (AMR) crisis. A primary driver of AMR is the selective pressure from antimicrobial use. Between 2000 and 2015, antibiotic consumption increased by 65%, reaching 34.8 billion tons, 73% of which was used in animals. In the dairy cattle sector, antibiotics are crucial for treating diseases like mastitis, posing risks to humans, animals and potentially leading to environmental contamination. To address AMR, strategies like selective dry cow therapy, alternative treatments (nanoparticles, phages) and waste management innovations are emerging. However, most solutions are in development, emphasizing the urgent need for further research to tackle AMR in dairy farms.

Antibiotics are becoming less effective at fighting infections because of antimicrobial resistance (AMR). This phenomenon is mainly caused by the abuse and misuse of antibiotics in both human and veterinary medicine. In the dairy cow industry, the use of antibiotics to treat diseases is a big concern. Ways to tackle this include the promotion of the responsible use of antibiotics, the development of alternative treatments and the discovery of better methods to deal with animal waste. However, much of these are still in development.

Diacetylcurcumin: a novel strategy against Enterococcus faecalis biofilm in root canal disinfection.

Aim: We evaluated Diacetylcurcumin (DAC), a derivative of curcumin, for its antibacterial and antibiofilm properties against Enterococcus faecalis. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined, along with antibiofilm potential and toxicity in Galleria mellonella. Additionally, in silico computational analysis was performed to understand its mechanisms of action. Results & conclusion: DAC demonstrated significant antibacterial effects, with MIC and MBC values of 15.6 and 31.25 µg/ml, respectively, and reduced biofilm formation. A synergistic effect, reducing biofilm by 77%, was observed when combined with calcium hydroxide. G. mellonella toxicity tests confirmed DAC's safety at tested concentrations, suggesting its potential for use in root canal disinfection products.

Diacetylcurcumin (DAC) comes from turmeric, a natural spice often used in food. DAC may have the ability to fight germs, including the bacteria Enterococcus faecalis. We tested DAC's ability to kill E. faecalis and stopping the formation of films of the bacteria. We found that a small amount of DAC did kill E. faecalis. When used with calcium hydroxide, DAC works even better to reduce the formation of bacterial films by 77%. DAC is safe to be used on teeth, so may be a useful ingredient for preserving mouth health.

Gut bacterium Burkholderia cepacia (BsNLG8) and immune gene Defensin A contribute to the resistance against Nicotine-induced stress in Nilaparvata lugens (Stål).

Nicotine, a naturally occurring alkaloid found in tobacco, is a potent neurotoxin extensively used to control Nilaparvata lugens (Stål), a destructive insect pest of rice crops. The insect gut harbors a wide array of resident microorganisms that profoundly influence several biological processes, including host immunity. Maintaining an optimal gut microbiota and immune homeostasis requires a complex network of reciprocal regulatory interactions. However, the underlying molecular mechanisms driving these symbiotic exchanges, particularly between specific gut microbe and immunity, remain largely unknown in insects. Our previous investigations identified and isolated a nicotine-degrading Burkholderia cepacia strain (BsNLG8) with antifungal properties. Building on those findings, we found that nicotine intake significantly increased the abundance of a symbiotic bacteria BsNLG8, induced a stronger bacteriostatic effect in hemolymph, and enhanced the nicotine tolerance of N. lugens. Additionally, nicotine-induced antimicrobial peptides (AMPs) exhibited significant antibacterial effects against Staphylococcus aureus. We adopted RNA-seq to explore the underlying immunological mechanisms in nicotine-stressed N. lugens. Bioinformatic analyses identified numerous differentially expressed immune genes, including recognition/immune activation (GRPs and Toll) and AMPs (i.e., Defensin, Lugensin, lysozyme). Temporal expression profiling (12, 24, and 48 hours) of immune genes revealed pattern recognition proteins and immune effectors as primary responders to nicotine-induced stress. Defensin A, a broad-spectrum immunomodulatory cationic peptide, exhibited significantly high expression. RNA interference-mediated silencing of Defensin A reduced the survival, enhanced nicotine sensitivity of N. lugens to nicotine, and decreased the abundance of BsNLG8. The reintroduction of BsNLG8 improved the expression of immune genes, aiding nicotine resistance of N. lugens. Our findings indicate a potential reciprocal immunomodulatory interaction between Defensin A and BsNLG8 under nicotine stress. Moreover, this study offers novel and valuable insights for future research into enhancing nicotine-based pest management programs and developing alternative biocontrol methods involving the implication of insect symbionts.

Combining deep learning and droplet microfluidics for rapid and label-free antimicrobial susceptibility testing of colistin.

Efficient tools for rapid antibiotic susceptibility testing (AST) are crucial for appropriate use of antibiotics, especially colistin, which is now often considered a last resort therapy with extremely drug resistant Gram-negative bacteria. Here, we developed a rapid, easy and miniaturized colistin susceptibility assay based on microfluidics, which allows for culture and high-throughput analysis of bacterial samples. Specifically, a simple microfluidic platform that can easily be operated was designed to encapsulate bacteria in nanoliter droplets and perform a fast and automated bacterial growth detection in 2 h, using standardized samples. Direct bright-field imaging of compartmentalized samples proved to be a faster and more accurate detection method as compared to fluorescence-based analysis. A deep learning powered approach was implemented for the sensitive detection of the growth of several strains in droplets. The DropDeepL AST method (Droplet and Deep learning-based method for AST) developed here allowed the determination of the colistin susceptibility profiles of 21 fast-growing Enterobacterales (E. coli and K. pneumoniae), including clinical isolates with different resistance mechanisms, showing 100 % categorical agreement with the reference broth microdilution (BMD) method performed simultaneously. Direct AST of bacteria in urine samples on chip also provided accurate results in 2 h, without the need of complex sample preparation procedures. This method can easily be implemented in clinical microbiology laboratories, and has the potential to be adapted to a variety of antibiotics, especially for last-line antibiotics to optimize treatment of patients infected with multi-drug resistant strains.

Preparation, biological activity and antibacterial properties of tantalum surface-doped Ca2+/Zn2+nanorods.

In this research, we utilize porous tantalum, known for its outstanding elastic modulus and biological properties, as a base material in biomedical applications. The human skeletal system is rich in elements like Ca and Zn. The role of Zn is crucial for achieving a spectrum of sterilizing effects, while Ca is known to effectively enhance cell differentiation and boost cellular activity. The focus of this study is the modification of porous tantalum using a hydrothermal method to synthesize Ca2+/Zn2+-doped Ta2O5nanorods. These nanorods are subjected to extensive characterization techniques to confirm their structure and composition. Additionally, their biological performance is evaluated through a range of tests, including antibacterial assessments, MTT assays, and bacteria/cell scanning electron microscopy (SEM) analyses. The objective is to determine the most effective method of surface modification for porous tantalum, thereby laying a foundational theoretical framework for its surface enhancement. .

Mapping the future of antimicrobial use data collection in US animal agriculture: insights from FDA-funded pilot studies.

Antimicrobial use (AMU) contributes to the emergence of antimicrobial resistance, necessitating antimicrobial stewardship actions across all sectors using a One Health approach to preserve antimicrobial effectiveness. This overview delves into 2 FDA-funded projects focused on collecting and analyzing AMU data in major food-producing animal species (cattle, swine, turkeys, and chickens). Initiated in 2016, the projects aimed to establish baseline AMU information and pilot methodologies. This article describes the methodologies used by grantees for data collected from 2016 to 2021, emphasizing the diverse data sources and metrics utilized. Instead of summarizing the trends, it provides a list of publications generated from the grants. Factors contributing to successful data collection included early interaction and trust building between the producers/data holders and researchers. Shared challenges include limitations stemming from convenience sampling, variable industry participation, and lack of data covering all segments of a particular commodity (eg, data on breeding or young animals were lacking). Future collaborative efforts are needed to enhance data standardization, contextualization, representativeness, and reporting of national-scale AMU data going forward. Addressing these challenges and data gaps is essential for effective monitoring of AMU in veterinary settings and animal agriculture, in alignment with national strategies to combat antimicrobial resistance.

Transpiration-Inspired Fabric Dressing for Acceleration Healing of Wound Infected with Biofilm.

In chronic wound management, efficacious handling of exudate and bacterial infections stands as a paramount challenge. Here we introduced a novel biomimetic fabric, inspired by the natural transpiration mechanisms in plants. Uniquely, the fabric combines a commercial polyethylene terephthalate (PET) fabric with asymmetrically grown 1D rutile titanium dioxide (TiO2) micro/nanostructures, emulating critical plant features: hierarchically porous networks and hydrophilic water conduction channels. This structure endows the fabric with exceptional antigravity wicking-evaporation performance, evidenced by a 780% one-way transport capability and a 0.75 g h-1 water evaporation rate, which significantly surpasses that of conventional moisture-wicking textiles. Moreover, the incorporated 1D rutile TiO2 micro/nano-structures presented solar-light induced antibacterial activity, crucial for disrupting and eradicating wound biofilms. The biomimetic transpiration fabric has been employed to drain exudate and eradicate biofilms in Staphylococcus aureus (S. aureus)-infected wounds, demonstrating a much faster infection eradication capability compared to clinically common ciprofloxacin irrigation. These findings illuminate the path for developing high-performance, textile-based wound dressings, offering efficient clinical platforms to combat biofilms associated with chronic wounds. This article is protected by copyright. All rights reserved.

Broad-Spectrum Activity of Membranolytic Cationic Macrocyclic Peptides Against Multi-Drug Resistant Bacteria and Fungi.

The emergence of multidrug-resistant (MDR) strains causes severe problems in the treatment of microbial infections owing to limited treatment options. Antimicrobial peptides (AMPs) are drawing considerable attention as promising antibiotic alternative candidates to combat MDR bacterial and fungal infections. Herein, we present a series of small amphiphilic membrane-active cyclic peptides composed, in part, of various nongenetically encoded hydrophilic and hydrophobic amino acids. Notably, lead cyclic peptides 3b and 4b showed broad-spectrum activity against drug-resistant Gram-positive (MIC = 1.5-6.2 µg/mL) and Gram-negative (MIC = 12.5-25 µg/mL) bacteria, and fungi (MIC = 3.1-12.5 µg/mL). Furthermore, lead peptides displayed substantial antibiofilm action comparable to standard antibiotics. Hemolysis (HC50 = 230 µg/mL) and cytotoxicity (>70% cell viability against four different mammalian cells at 100 µg/mL) assay results demonstrated the selective lethal action of 3b against microbes over mammalian cells. A calcein dye leakage experiment substantiated the membranolytic effect of 3b and 4b, which was further confirmed by scanning electron microscopy. The behavior of 3b and 4b in aqueous solution and interaction with phospholipid bilayers were assessed by employing nuclear magnetic resonance (NMR) spectroscopy in conjunction with molecular dynamics (MD) simulations, providing a solid structural basis for understanding their membranolytic action. Moreover, 3b exhibited stability in human blood plasma (t1/2 = 13 h) and demonstrated no signs of resistance development against antibiotic-resistant S. aureus and E. coli. These findings underscore the potential of these newly designed amphiphilic cyclic peptides as promising anti-infective agents, especially against Gram-positive bacteria.

No evidence of difference in mortality with amoxicillin versus co-amoxiclav for hospital treatment of community-acquired pneumonia.

OBJECTIVES: Current guidelines recommend broad-spectrum antibiotics for high-severity community-acquired pneumonia (CAP), potentially contributing to antimicrobial resistance (AMR). We aim to compare outcomes in CAP patients treated with amoxicillin (narrow-spectrum) versus co-amoxiclav (broad-spectrum), to understand if narrow-spectrum antibiotics could be used more widely. METHODS: We analysed electronic health records from adults (≥16y) admitted to hospital with a primary diagnosis of pneumonia between 01-January-2016 and 30-September-2023 in Oxfordshire, United Kingdom. Patients receiving baseline ([-12h,+24h] from admission) amoxicillin or co-amoxiclav were included. The association between 30-day all-cause mortality and baseline antibiotic was examined using propensity score (PS) matching and inverse probability treatment weighting (IPTW) to address confounding by baseline characteristics and disease severity. Subgroup analyses by disease severity and sensitivity analyses with missing covariates imputed were also conducted. RESULTS: Among 16,072 admissions with a primary diagnosis of pneumonia, 9,685 received either baseline amoxicillin or co-amoxiclav. There was no evidence of a difference in 30-day mortality between patients receiving initial co-amoxiclav vs. amoxicillin (PS matching: marginal odds ratio 0.97 [0.76-1.27], p=0.61; IPTW: 1.02 [0.78-1.33], p=0.87). Results remained similar across stratified analyses of mild, moderate, and severe pneumonia. Results were also similar with missing data imputed. There was also no evidence of an association between 30-day mortality and use of additional macrolides or additional doxycycline. CONCLUSIONS: There was no evidence of co-amoxiclav being advantageous over amoxicillin for treatment of CAP in 30-day mortality at a population-level, regardless of disease severity. Wider use of narrow-spectrum empirical treatment of moderate/severe CAP should be considered to curb potential for AMR.

Antimicrobial activity of Southern African medicinal plants on Helicobacter pylori and Lactobacillus species.

ETHNOPHARMACOLOGICAL RELEVANCE: Numerous medicinal plants have been used traditionally in South Africa for gastric ulcer treatment. Helicobacter pylori is known for causing inflammation and the onset of gastric ulcers. While several studies explored medicinal plants against H. pylori, investigation of medicinal plants used for gastric ulcers has been neglected, as well as the effects these plants would have on bacteria occurring naturally in the gut microbiome. AIM OF THE STUDY: This study aimed to investigate Southern African medicinal plants used traditionally for treating gastric ulcers against H. pylori and against Lactobacillus species, as well as the effects of these plants combined with the Lactobacillus species against H. pylori. METHODOLOGY: Based on evidence from the ethnobotanical literature, 21 plants were collected. Their antimicrobial activity was assessed against five clinical H. pylori strains, and in combination with each of three Lactobacillus species, using the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) broth microdilution assays. Toxicity was assessed using the brine shrimp lethality assay. RESULTS: Noteworthy activity was observed against at least one H. pylori strain for 12 plant species. The lowest mean MICs were from organic extracts of Carissa edulis Vahl (0.18 mg/mL) and Chironia baccifera L. (0.20 mg/mL), and aqueous extracts of Sansevieria hyacinthoides (L.) Druce (0.26 mg/mL) and Dodonaea viscosa Jacq. (0.30 mg/mL). Aqueous extracts of the investigated plants were combined with Lactobacillus species, and the majority of combinations showed increased antimicrobial activity compared with the extracts alone. Combinations of Lactobacillus rhamnosus with 18 of the 21 aqueous plant extracts showed at least a two-fold decrease in the mean MBC against all H. pylori strains tested. Lactobacillus acidophilus combined with either Protea repens L., Carpobrotus edulis (L.) L.Bolus or Warburgia salutaris (Bertol.f.) Chiov. aqueous extracts had the best anti-H. pylori activity (mean MBCs of 0.10 mg/mL for each combination). Only four organic and one aqueous extract(s) were considered toxic. CONCLUSION: These results highlight the potential of medicinal plants to inhibit H. pylori growth and their role in traditional treatments for the management of ulcers. The results also indicate that aqueous extracts of these plants do not hinder the growth of bacteria that occur naturally in the gut microbiome and play a role in maintaining gut health, as well as show the potential benefit of including Lactobacillus species in treatment as potentiators of H. pylori activity.

Modelling Plasmid-Mediated Horizontal Gene Transfer in Biofilms.

In this study, we present a mathematical model for plasmid spread in a growing biofilm, formulated as a nonlocal system of partial differential equations in a 1-D free boundary domain. Plasmids are mobile genetic elements able to transfer to different phylotypes, posing a global health problem when they carry antibiotic resistance factors. We model gene transfer regulation influenced by nearby potential receptors to account for recipient-sensing. We also introduce a promotion function to account for trace metal effects on conjugation, based on literature data. The model qualitatively matches experimental results, showing that contaminants like toxic metals and antibiotics promote plasmid persistence by favoring plasmid carriers and stimulating conjugation. Even at higher contaminant concentrations inhibiting conjugation, plasmid spread persists by strongly inhibiting plasmid-free cells. The model also replicates higher plasmid density in biofilm's most active regions.

Prevalence and Resistance Patterns of Urinary Tract Infection in Al-Madinah Al-Munawarah, Saudi Arabia: A Retrospective Study.

BACKGROUND: Urinary tract infections (UTIs) are among the most common infections and can cause numerous complications of the renal system. This study aimed to assess the prevalence of uropathogens and their antibiotic susceptibility patterns in Al-Madinah Al-Munawarah, Saudi Arabia. METHODS: Data was collected from patients with UTIs presented at King Fahad General Hospital in Al-Madinah Al-Munawarah, Saudi Arabia. In this retrospective cross-sectional study, UTI microbial-causing agents and antimicrobial resistance profiles identified using automated systems, Phoenix and VITEK2, were collected between July 2022 and June 2023. In addition, minimal demographic data, including date of collection and sex and age of patients were collected and analyzed using Chi-square test. RESULTS: The study included 1394 patients positive for UTI, comprising 50.57% males and 49.43% females (chi-square goodness-of-fit, p > 0.999). Microbial identification and antimicrobial susceptibility tests were performed on UTI-positive cultures. Among UTIs, mono-infection, caused by a single pathogen, was the most prevalent, accounting for 88.16% of cases, whereas poly-infection (caused by multiple pathogens) presented at 11.9%. The most prevalent UTIs' pathogens were E. coli (30.59%), followed by Klebsiella pneumoniae (21.40%), Enterococcus faecalis (8.46%), Pseudomonas aeruginosa (7.81%), Streptococcus agalactiae (6.35%), Enterococcus faecium (3.01%), Proteus mirabilis (3.01%), Enterobacter cloacae (2.52%), Candida sp. (2.44%), Acinetobacter calcoaceticus-baumannii (1.95%), Staphylococcus aureus (1.79%), and Enterobacter aerogenes (1.30%). The most dominant pathogens that coexisted with other uropathogens to cause UTIs were K. pneumoniae and P. mirabilis (9.32%, chi-square 5.550, p = 0.018), K. pneumoniae and P. aeruginosa (8.07%, chi-square 6.285, p = 0.012), K. pneumoniae and E. faecalis (7.45%, chi-square 5.785, p = 0.016), Candida sp. and Enterococcus faecium (4.97%, chi-square 9.176, p = 0.002, and Candida sp. and Acinetobacter calcoaceticus-baumannii (3.11%, chi-square 4.312, p=0.038)). Among the uropathogens, gram-negative pathogens showed resistance to most of the tested antimicrobials (ampicillins, cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, aztreonam, and nitrofurantoin). High rates of resistance were identified to cephalosporins, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole. CONCLUSION: This study reported UT mono-infection and poly-infection in Al-Madinah Al-Munawarah, Saudi Arabia, with a predominant representation from gram-negative bacteria, Enterobacteriaceae. Most of the UT microbial strains showed a highly resistant profile.