Spectrum Antibiotics Research Articles

Silk Sericin and Its Composite Materials with Antibacterial Properties to Enhance Wound Healing: A Review.

Wound infections may disrupt the normal wound-healing process. Large amounts of antibiotics are frequently used to prevent pathogenic infections; however, this can lead to resistance development. Biomaterials possessing antimicrobial properties have promising applications for reducing antibiotic usage and promoting wound healing. Silk sericin (SS) has been increasingly explored for skin wound healing applications owing to its excellent biocompatibility and antioxidant, antimicrobial, and ultraviolet-resistant properties. In recent years, SS-based composite biomaterials with a broader antimicrobial spectrum have been extensively investigated and demonstrated favorable efficacy in promoting wound healing. This review summarizes various antimicrobial agents, including metal nanoparticles, natural extracts, and antibiotics, that have been incorporated into SS composites for wound healing and elucidates their mechanisms of action. It has been revealed that SS-based biomaterials can achieve sustained antimicrobial activity by slow-release-loaded antimicrobial agents. The antimicrobial-loaded SS composites may promote wound healing through anti-infection, anti-inflammation, hemostasis, angiogenesis, and collagen deposition. The manufacturing methods, benefits, and limitations of antimicrobial-loaded SS materials are briefly discussed. This review aims to enhance the understanding of new advances and directions in SS-based antimicrobial composites and guide future biomedical research.

Evaluation of antimicrobial stewardship activities using antibiotic spectrum coverage

Recently, the days of antibiotic spectrum coverage (DASC) using the antibiotic spectrum coverage (ASC) score was reported as a new tool for measuring antimicrobial use. The days of therapy (DOT) are required to calculate the DASC, making it impossible to use when patient-level information is unavailable. Therefore, we have defined a new measure of antimicrobial use for antimicrobial spectrum coverage (AUSC) using antimicrobial use density (AUD) and ASC scores. In this study, we have investigated the use of antimicrobial agents retrospectively examined for monthly prescriptions between 2016 and 2022, and whether the AUSC could be used as a new measure. Our data showed that the AUD, AUSC, DOT, and DASC increased, whereas AUSC/AUD and DASC/DOT decreased over the study period. In addition, no correlation was found between DOT and DASC/DOT (ρ = − 0.093, p = 0.399), whereas there was a weak correlation between AUD and AUSC/AUD (ρ = − 0.295, p = 0.006). Therefore, in this study, the use of AUSC is considered less beneficial when DASC can be calculated based on DOT. On the other hand, in institutional settings where DOT cannot be calculated, AUSC may be useful as a new measure to evaluate antimicrobial use.

Different Oligosaccharides Induce Coordination and Promotion of Root Growth and Leaf Senescence during Strawberry and Cucumber Growth

Oligosaccharides, as a wide type of polysaccharide, have a broad antimicrobial spectrum and promote development as plant growth stimulants. To investigate the regulation effects of different oligosaccharides on the dynamic changes of chlorophyll content, leaf fluorescence, root activity and morphology, and chloroplast ultrastructure, as well as the yields and yield components of strawberry and cucumber, typical greenhouse experiments were conducted over two years (2021–2022). The experimental plants were foliar sprayed with tap water (CK), chitosan oligosaccharide (CSOS), and mixed oligosaccharides (MixOS) five times before flowering. The conventional management (CM) was conducted as a conventional control. The findings of the present study suggest that the application of MixOS has the greatest regulation effects on delayed leaf senescence, well-developed roots, and higher fruit productions of strawberry and cucumber. Exogenous MixOS resulted in significant increases in SPAD values, maximum photochemical efficiency (Fv/Fm), and photochemical quenching coefficiency (qP); they were increased by 1.94–28.96%, 5.41–33.89%, and 9.93–62.07%, compared to the CSOS, CM, and CK treatments, respectively. The orderly and steady structure of thylakoids in the chloroplast, and the randomly distributed starch grains, could be clearly observed in the MixOS treatment, while the non-photochemical quenching (NPQ) was correspondingly reduced by 19.04–45.92%. Meanwhile, the remarkable promotion of root activity and root surface morphology indicators (i.e., root length, surface area, average diameter, and volume) could be observed when exposed to the MixOS treatments, and the total yields of strawberry and cucumber were all increased by 12.40–25.57%. These findings suggest that the mixed oligosaccharides mainly promote the coordinated growth of root and shoot, which leads to the improved yields of strawberry and cucumber.

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.

Effects of prolonged application of peracetic acid-based disinfectant on recirculating aquaculture systems stocked with Atlantic salmon parr

The use of recirculating aquaculture systems (RAS) for Atlantic salmon (Salmo salar) production has become increasingly common. RAS water disinfection plays a crucial role on its biosecurity. Peracetic acid (PAA) is a promising disinfectant due to its powerful oxidative properties, broad antimicrobial spectrum, and rapid degradation into no harmful compounds. This study focused on assessing the consequences of prolonged application of a PAA-based disinfectant in a RAS stocked with salmon parr. The experiment included three treatment groups in triplicate: 0 mg/L PAA (control), 0.1 mg/L PAA, and 1 mg/L PAA, using nine-replicated RAS with a total of 360 fish (14.8 ± 2.3 g; N = 40/RAS). The study spanned 28 days, with samples collected on days 0, 14, and 28. The analyzed parameters were water quality, and fish parameters, including external welfare indicators, gill histology, total antioxidant capacity (TAC), reactive oxygen species/reactive nitrogen species (ROC/RNC), oxidative stress biomarkers related to DNA and protein, cellular DNA damage, and global gene expression. While water quality remained relatively stable, there was an increase in bacterial populations in the groups exposed to PAA, particularly 1 mg/L PAA. Fish weight did not differ between the control and PAA-exposed groups. TAC, ROC/RNC, and oxidative stress biomarkers exhibited similar trends. The study identified >400 differentially expressed genes (DEGs) in the skin, gill, and olfactory organ, with many of these DEGs associated with immune responses. Comparing the transcriptomic profiles of the three tissue organs revealed that the olfactory organ was the most reactive to PAA treatment. This study shows that calculated PAA concentrations of 0.1 mg/L and 1 mg/L in the pump-sump, contributed to an increase of bacteria whereas no detectable differences in health and welfare of salmon parr were found. These findings are promising for the implementation of PAA-based disinfectants in RAS stoked with Atlantic salmon parr.

Joint effects about antibiotics combined using with antibiotics or phytochemicals on Aeromonas hydrophila

Aeromonas hydrophila is highly prevalent in aquaculture animals and aquaculture environment. Due to the abuse of antibiotics, A. hydrophila can change the antibiotic resistance spectrum directly and affect human health indirectly. The use of combined drugs replacement therapy and the long-term coexistence with drug-resistant bacteria are the reality that human beings have to face in dealing with the problem of antibiotic resistance in the future. This study showed the characteristics and trends through abundant results of combined effects related with the combinations of antibiotic and the combinations of antibiotic and phytochemical on A. hydrophila, and revealed the antagonism probability of combinations of antibiotic and phytochemical is significantly higher than that of the combinations of antibiotic. Meanwhile, the combinations of antibiotic and phytochemical could protect the host cells which also achieved the same effectiveness as combination of antibiotics, and the enrichment pathway was proved to be relatively discrete. In addition, the possible mechanism about the reverse “U" shape of the combined effect curve on wild/antibiotic-resistant bacteria was clarified, and it was confirmed that the antagonism for the combinations of antibiotic and phytochemical might has the significance in inhibiting the evolution of bacterial resistance mutations. This study was aims to provide theoretical basis and some clues for the antibiotic resistance control associated with A. hydrophila.

Antimicrobial Resistance of Listeria monocytogenes Strains Isolated in Food and Food-Processing Environments in Italy

Listeria monocytogenes, along with various other pathogenic bacteria, may show resistance against a broad spectrum of antibiotics. Evaluating the extent of resistance in harmful microorganisms like Listeria monocytogenes holds significant importance in crafting novel therapeutic strategies to mitigate or combat the rise of infections stemming from antibiotic-resistant bacteria. The present work aims to investigate the occurrence of antimicrobial resistance among Listeria monocytogenes strains in meat products (n = 173), seafood (n = 54), dairy products (n = 19), sauces (n = 2), confectionary products (n = 1), ready-to-eat rice dishes (n = 1), and food-processing environments (n = 19). A total of 269 Listeria monocytogenes strains belonging to eight different serovars were tested against 10 antimicrobials. In the classes of antibiotics, most of the strains were resistant antibiotics belonging to the family of β-lactams (92.94%). High proportions of L. monocytogenes isolates were resistant to oxacillin (88.48%), followed by fosfomycin (85.87%) and flumenique (78.44%). The lowest level of resistance was observed against gentamycin (1.49%). A total of 235 strains (n = 87.36%) showed a profile of multidrug resistance. In conclusion, a high occurrence of resistant and multidrug-resistant strains of Listeria monocytogenes was observed among the examined serotypes isolated from different food sources. This understanding enables the adoption of suitable measures to avert contamination and the spread of resistant bacteria via food.

P262 Lack of association between antibiotic regimen spectrum and pulmonary exacerbation treatment responses

P262 Lack of association between antibiotic regimen spectrum and pulmonary exacerbation treatment responses

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.

A randomised trial comparing preoperative administration of single-dose kefazolin to kefazolin plus metronidazole as prophylactic antibiotics at caesarean section.

Caesarean section is a life-saving procedure which is associated with high rates of maternal and neonatal complications. It has been estimated that globally, 29.7 million births occur by caesarean section annually. The risk of postpartum infection is estimated to be five to ten times higher compared with normal vaginal delivery. Pregnancy-related sepsis was listed as a top-six cause of maternal mortality in the South African Saving Mothers report between 2017 and 2019. Multiple trials have been conducted in an attempt to optimise administration of prophylactic antibiotics in an effort to reduce postpartum infection and maternal sepsis, and current practice guidelines suggest that there is sufficient evidence that extended-spectrum antibiotics, in combination with kefazolin, result in reduction of postpartum infections. To investigate the effect of perioperative administration of kefazolin alone compared with kefazolin plus metronidazole on postpartum infection in women undergoing caesarean section at Kalafong Provincial Tertiary Hospital, Pretoria, South Africa. All patients undergoing emergency or elective caesarean section were randomised and then sequentially numbered in opaque sealed envelopes, which were placed in the caesarean section operating theatre. The intervention group received kefazolin and a sealed envelope with metronidazole. The control group received kefazolin and a sealed envelope with normal saline. A total of 57/1 010 patients (5.64%) had surgical site infections, of which 27 (5.33%) were in the control group, and 30 (5.96%) were in the intervention group (p=0.66). Two patients in each arm (0.40% in the intervention arm and 0.39% in the control arm) underwent laparotomy procedures, while three women (0.60%) in the intervention arm and four women (0.79%) in the control arm underwent hysterectomy procedures. There were no statistically significant differences in all the measured secondary outcomes between the two groups. The overall sepsis rate in this study was 5.64%. Postpartum infection is multifactorial and there are multiple factors that can be addressed in strengthening the sepsis care bundle. We do not recommend the addition of metronidazole to kefazolin as prophylaxis at caesarean section.

Antibiotic exposure and depression incidence: A cohort study of the Korean population

Recent research highlights the crucial role of the gut-brain axis in understanding depression etiologies. While burgeoning studies suggest an association between disruptions in gut microbiota and the development of depression, limited longitudinal studies have investigated this link. To address this gap, we conducted a retrospective cohort study using National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) data in South Korea, involving 199,144 individuals aged 40–79. We examined the impact of cumulative antibiotic exposure (2004–2008) on subsequent depression incidence (2009–2013) by conducting Cox proportional hazards regressions. Our findings show an increasing depression risk with extended antibiotic exposure after adjusting for comorbidities and behavioral covariates. A broader antibiotic spectrum was associated with a higher depression risk. These trends persisted after adjusting for the original antibiotic indications. In conclusion, our study highlights the duration-dependent association between antibiotic exposure and increased depression risk, offering insights into depression etiologies and relevant novel therapeutic tools, and advocating for heightened antibiotic stewardship considering their impact on mental health.

Optimization of Culturing Conditions for the Production of Antimicrobial Metabolite by Bacillus Carotarum

Forest soil antagonistic bacteria Bacillus carotarum was isolated and tested for optimum antimicrobial metabolite production. Maximum antimicrobial metabolite production was found at temperature 30°C and pH 7.0 and on Ist day of incubation at stationary condition. The medium consisting of beef extract - 0.3%, peptone - 0.5% and NaCl - 0.05%, was screened out as a suitable medium for maximum antimicrobial production supplemented individually with four carbon sources of which starch was found as the best carbon source. The active agent was best extracted with petroleum ether. Homogeneity of the crude bioactive metabolites were also tested by paper chromatographic analysis where a single type of bioactive metabolite was found with a Rf value of 0.94 in the solvent system n- butanol: acetic acid : water = 4 : 1 : 5 . The antimicrobial spectrum of the metabolite was wide and showed activity against Shigella dysenteriae (AE14612), Salmonella typhi(AE14296), Vibrio cholerae (A214748), Pseudomonas aeruginosa (CRL, ICDDR’ B), Bacillus cereus (BTCC19), and Bacillus subtilis (BTTC17). The Chittagong Univ. J. B. Sci. 8(1&2): 01-10, 2013

New Naphthalene Derivatives from the Mangrove Endophytic Fungus Daldinia eschscholzii MCZ-18.

Five new naphthalene derivatives dalesconosides A-D, F (1-4, 6), a known synthetic analogue named dalesconoside E (5), and eighteen known compounds (7-24) were isolated from Daldinia eschscholzii MCZ-18, which is an endophytic fungus obtained from the Chinese mangrove plant Ceriops tagal. Differing from previously reported naphthalenes, compounds 1 and 2 were bearing a rare ribofuranoside substituted at C-1 and the 5-methyltetrahydrofuran-2,3-diol moiety, respectively. Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. Compounds 1, 3, 13-17 and 19 showed broad ranges of antimicrobial spectrum against five indicator test microorganisms (Enterococcus faecalis, Methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans); especially, 1, 16 and 17 were most potent. The variations in structure and attendant biological activities provided fresh insights concerning structure-activity relationships for the naphthalene derivatives.

Biotechnological potential of actinomycetes in the 21st century: a brief review.

This brief review aims to draw attention to the biotechnological potential of actinomycetes. Their main uses as sources of antibiotics and in agriculture would be enough not to neglect them; however, as we will see, their biotechnological application is much broader. Far from intending to exhaust this issue, we present a short survey of the research involving actinomycetes and their applications published in the last 23years. We highlight a perspective for the discovery of new active ingredients or new applications for the known metabolites of these microorganisms that, for approximately 80years, since the discovery of streptomycin, have been the main source of antibiotics. Based on the collected data, we organize the text to show how the cosmopolitanism of actinomycetes and the evolutionary biotic and abiotic ecological relationships of actinomycetes translate into the expression of metabolites in the environment and the richness of biosynthetic gene clusters, many of which remain silenced in traditional laboratory cultures. We also present the main strategies used in the twenty-first century to promote the expression of these silenced genes and obtain new secondary metabolites from known or new strains. Many of these metabolites have biological activities relevant to medicine, agriculture, and biotechnology industries, including candidates for new drugs or drug models against infectious and non-infectious diseases. Below, we present significant examples of the antimicrobial spectrum of actinomycetes, which is the most commonly investigated and best known, as well as their non-antimicrobial spectrum, which is becoming better known and increasingly explored.

The complete catalog of antimicrobial resistance secondary active transporters in Clostridioides difficile: evolution and drug resistance perspective

Secondary active transporters shuttle substrates across eukaryotic and prokaryotic membranes, utilizing different electrochemical gradients. They are recognized as one of the antimicrobial efflux pumps among pathogens. While primary active transporters within the genome of C. difficile 630 have been completely cataloged, the systematical study of secondary active transporters remains incomplete. Here, we not only identify secondary active transporters but also disclose their evolution and role in drug resistance in C. difficile 630. Our analysis reveals that C. difficile 630 carries 147 secondary active transporters belonging to 27 (super)families. Notably, 50 (34%) of them potentially contribute to antimicrobial resistance (AMR). AMR-secondary active transporters are structurally classified into five (super)families: the p-aminobenzoyl-glutamate transporter (AbgT), drug/metabolite transporter (DMT) superfamily, major facilitator (MFS) superfamily, multidrug and toxic compound extrusion (MATE) family, and resistance-nodulation-division (RND) family. Surprisingly, complete RND genes found in C. difficile 630 are likely an evolutionary leftover from the common ancestor with the diderm. Through protein structure comparisons, we have potentially identified six novel AMR-secondary active transporters from DMT, MATE, and MFS (super)families. Pangenome analysis revealed that half of the AMR-secondary transporters are accessory genes, which indicates an important role in adaptive AMR function rather than innate physiological homeostasis. Gene expression profile firmly supports their ability to respond to a wide spectrum of antibiotics. Our findings highlight the evolution of AMR-secondary active transporters and their integral role in antibiotic responses. This marks AMR-secondary active transporters as interesting therapeutic targets to synergize with other antibiotic activity.

Early online.

Caesarean section is a life-saving procedure which is associated with high rates of maternal and neonatal complications. It has been estimated that globally, 29.7 million births occur by caesarean section annually. The risk of postpartum infection is estimated to be five to ten times higher compared to normal vaginal delivery. Pregnancy-related sepsis was listed as a top six cause of maternal mortality in the South African Saving Mothers report between 2017 and 2019. Multiple trials have been conducted in an attempt to optimise administration of prophylactic antibiotics in an effort to reduce postpartum infection and maternal sepsis, and current practice guidelines suggest that there is sufficient evidence that extended spectrum antibiotics, in combination with kefazolin, result in reduction of postpartum infections Objectives. To investigate the effect of perioperative administration of kefazolin alone compared to kefazolin plus metronidazole on postpartum infection in women undergoing caesarean section at Kalafong Provincial Tertiary Hospital. All patients undergoing emergency or elective caesarean section were randomised and then sequentially numbered in opaque sealed envelopes, which were placed in the caesarean section operating theatre. The intervention group received kefazolin and a sealed envelope with metronidazole. The control group received kefazolin and a sealed envelope with normal saline. A total of 57/1 010 patients (5.64%) had surgical site infections, of which 27 (5.33%) were in the control group, and 30 (5.96%) were in the intervention group (p=0.66). Two patients in each arm (0.40% in the intervention arm and 0.39% in the control arm) underwent laparotomy procedures, while three women (0.60%) in the intervention arm and four women (0.79%) in the control arm underwent hysterectomy procedures. There were no statistically significant differences in all the measured secondary outcomes between the two groups. The overall sepsis rate in this study was 5.64%. Postpartum infection is multifactorial and there are multiple factors that can be addressed in strengthening the sepsis care bundle. We do not recommend the addition of metronidazole to kefazolin as prophylaxis at caesarean section.

A study on clinico-demographic and microbiological profile of surgical site infection (SSI) in a tertiary care hospital, Kolkata: An alarming trend

The Centres for Disease Control and Prevention (CDC) estimates surgical site infections SSI is major contributor of healthcare associated infections (HAI). Multidrug resistant (MDR) Gram-negative bacilli are emerging pathogens. This study aimed to determine the magnitude of SSI and identify predominant pathogens with their antimicrobial susceptibility patterns. It is a hospital-based descriptive cross-sectional study including 2070 suspected SSI specimens from 25809 surgeries between 1July 2021 to 30 June 2023. Organisms’ identification and AST was done by both conventional and automated methods. Data was collected and analysed on MS-Excel sheet with various charts and tables. In our study SSI rate was 6.3%, much higher than previous study (2.83%) from this institution. SSI rate was highest in plastic surgery (8.2%). Major pathogens of SSI were Gram-negative bacilli e.g., (26.34%), (25.59%) and (74.69%) was predominant among Gram-positive cocci. Gram-negative bacilli including enterobacterales and non-fermenter and showed resistance to major classes of broad- spectrum antibiotics. Methicillin resistance (MRSA) was 43.9%, which indicates need to improve infection control practices. Our study showed significant higher proportion of SSI as compared to previous studies from the same institute with alarming number of isolated MDR Gram-negative bacilli. So, this study focusses the need of robust infection control practices and strict implementation of antimicrobial stewardship to overcome challenges of antimicrobial resistance.

An essential component of antimicrobial stewardship during the COVID-19 pandemic in the intensive care unit: de-escalation

BackgroundThe antimicrobial de-escalation strategy (ADE) plays a crucial role in antimicrobial stewardship, reducing the likelihood of bacterial resistance. This study aims to evaluate how often the intensive care unit (ICU)...

Insights into the novel Enterococcus faecalis phage: A comprehensive genome analysis.

Enterococcus faecalis, a Gram-positive bacterium, poses a significant clinical challenge owing to its intrinsic resistance to a broad spectrum of antibiotics, warranting urgent exploration of innovative therapeutic strategies. This study investigated the viability of phage therapy as an alternative intervention for antibiotic-resistant E. faecalis, with a specific emphasis on the comprehensive genomic analysis of bacteriophage SAM-E.f 12. The investigation involved whole-genome sequencing of SAM-E.f 12 using Illumina technology, resulting in a robust dataset for detailed genomic characterization. Bioinformatics analyses were employed to predict genes and assign functional annotations. The bacteriophage SAM-E.f 12, which belongs to the Siphoviridae family, exhibited substantial potential, with a burst size of 5.7 PFU/infected cells and a latent period of 20 min. Host range determination experiments demonstrated its effectiveness against clinical E. faecalis strains, positioning SAM-E.f 12 as a precise therapeutic agent. Stability assays underscore resilience across diverse environmental conditions. This study provides a comprehensive understanding of SAM-E.f 12 genomic composition, lytic lifecycle parameters, and practical applications, particularly its efficacy in murine wound models. These results emphasize the promising role of phage therapy, specifically its targeted approach against antibiotic-resistant E. faecalis strains. The nuanced insights derived from this research will contribute to the ongoing pursuit of efficacious phage therapies and offer valuable implications for addressing the clinical challenges associated with E. faecalis infections.

Influence of Antibiotic Exposure Intensity on the Risk of Clostridioides difficile Infection.

Antibiotics are a strong risk factor for Clostridioides difficile infection (CDI), and CDI incidence is often measured as an important outcome metric for antimicrobial stewardship interventions aiming to reduce antibiotic use. However, risk of CDI from antibiotics varies by agent and dependent on the intensity (i.e., spectrum and duration) of antibiotic therapy. Thus, the impact of stewardship interventions on CDI incidence is variable, and understanding this risk requires a more granular measure of intensity of therapy than traditionally used measures like days of therapy (DOT). We performed a retrospective cohort study to measure the independent association between intensity of antibiotic therapy, as measured by the antibiotic spectrum index (ASI), and hospital-associated CDI (HA-CDI) at a large academic medical center between January 2018 and March 2020. We constructed a marginal Poisson regression model to generate adjusted relative risks for a unit increase in ASI per antibiotic day. We included 35,457 inpatient encounters in our cohort. Sixty-eight percent of patients received at least one antibiotic. We identified 128 HA-CDI cases, which corresponds to an incidence rate of 4.1 cases per 10,000 patient-days. After adjusting for known confounders, each additional unit increase in ASI per antibiotic day is associated with 1.09 times the risk of HA-CDI (Relative Risk = 1.09, 95% Confidence Interval: 1.06 to 1.13). ASI was strongly associated with HA-CDI and could be a useful tool in evaluating the impact of antibiotic stewardship on HA-CDI rates, providing more granular information than the more commonly used days of therapy.