Alternative Antibiotics Research Articles

Characterization of Newly Isolated Bacteriophages Targeting Carbapenem-Resistant Klebsiella pneumoniae.

Klebsiella pneumoniae, a Gram-negative opportunistic pathogen, is increasingly resistant to carbapenems in clinical settings. This growing problem necessitates the development of alternative antibiotics, with phage therapy being one promising option. In this study, we investigated novel phages targeting carbapenem-resistant Klebsiella pneumoniae (CRKP) and evaluated their lytic capacity against clinical isolates of CRKP. First, 23 CRKP clinical isolates were characterized using Multi-Locus Sequence Typing (MLST), carbapenemase test, string test, and capsule typing. MLST classified the 23K. pneumoniae isolates into 10 sequence types (STs), with the capsule types divided into nine known and one unknown type. From sewage samples collected from a tertiary hospital, 38 phages were isolated. Phenotypic and genotypic characterization of these phages was performed using Random Amplification of Polymorphic DNA-PCR (RAPD-PCR), transmission electron microscopy (TEM), and whole genome sequencing (WGS) analysis. Host spectrum analysis revealed that each phage selectively lysed strains sharing the same STs as their hosts, indicating ST-specific activity. These phages were subtyped based on their host spectrum and RAPD-PCR, identifying nine and five groups, respectively. Fourteen phages were selected for further analysis using TEM and WGS, revealing 13 Myoviruses and one Podovirus. Genomic analysis grouped the phages into three clusters: one closely related to Alcyoneusvirus, one to Autographiviridae, and others to Straboviridae. Our results showed that the host spectrum of K. pneumoniae-specific phages corresponds to the STs of the host strain. These 14 novel phages also hold promise as valuable resources for phage therapy against CRKP.

Synergistic antimicrobial activity of lynronne-1 and EDTA against bovine mastitis pathogens.

Bovine mastitis is the costliest disease in the dairy sector and the main cause of antibiotic use in dairy cattle, potentially contributing to the antimicrobial resistance crisis. Antimicrobial peptides (AMPs) offer promise as antibiotic alternatives for controlling mastitis pathogens. The efficacy of five AMPs (Lynronne-1 [Lyn-1], Lynronne-2 [Lyn-2], Bovicin HC5, AMP 660, and AMP 1043) and two bioactive compounds (disodium ethylenediaminetetraacetic acid [EDTA] and glycerol monolaurate) was assessed against a range of 35 mastitis-causing pathogens. The fractional inhibitory concentrations index (FICI) was calculated to determine the interaction effect and values ≤0.5 were indicative of synergism. Time-dependent killing assays were performed to assess bactericidal efficacy of the combination. Cytotoxicity was evaluated using the MTT assay and haemolytic activity was assessed against fresh bovine erythrocytes. Lyn-1 and EDTA exhibited the highest broad spectrum antimicrobial activity and reduced bacterial growth (OD600 nm) by 95.1% and 86.9%, respectively. FICI values ranged from 0.1 to 0.5, indicating synergism. The combination of lyn-1 (0.03 mg/mL) and EDTA (1.02 mg/mL) exhibited higher antimicrobial activity against all bacterial strains, at significantly lower concentrations than each compound individually. Lyn-1-EDTA combination reduced viable population by >10 000-fold within 12 h. The combination was non-haemolytic in concentrations up to 8-fold the established MIC values (P > 0.05), although cytotoxic effects were observed at concentrations above MIC (P < 0.01). These findings highlight the therapeutic potential of Lyn-1 and Lyn-1-EDTA for developing antibiotic-free formulations to combat contagious and environmental mastitis pathogens and treat udder infections.

Macrolide-resistant Mycoplasma pneumoniae, North Dakota 2024.

A cluster of macrolide-resistant Mycoplasma pneumoniae causing community-acquired pneumonia was observed in children in North Dakota in 2024. Suspicion was raised by non-response to macrolides, with confirmation via a PCR assay. Prompt improvement occurred after initiation of alternative antibiotics.

Assessment of the Safety of Alternative Antibiotics in Children with Confirmed Beta-Lactam Antibiotic Allergy

Introduction: Beta-lactam antibiotics (BLAs) are the most common cause of drug hypersensitivity reactions in children, and it is important to find safe alternative antibiotics for these children. This study evaluates the selection, safety to alternative antibiotics in patients with confirmed BLA allergies based on diagnostic tests. Methods: At the Pediatric Immunology and Allergy Clinic of Ankara Bilkent City Hospital, a retrospective evaluation of diagnostic tests (including skin prick, intradermal, and drug provocation tests) was conducted to identify alternative antibiotics for patients with confirmed BLA. Patients were also contacted by telephone to assess their use of these alternative drugs. Results: The study included 80 patients with confirmed beta-lactam allergy (BLA). The BLAs causing reactions were categorized into two groups: penicillins (75%, n = 60) and cephalosporins (25%, n = 20). Among the penicillins, amoxicillin-clavulanic acid (ACA) was the most common at 68.8%, while among the cephalosporins, ceftriaxone was the most common at 16.3%. Of the 55 patients with ACA allergy, 53 underwent controlled administration with clarithromycin, with 52 showing no reaction. In addition, no reaction was observed in patients who received DPT with cefuroxime (n: 16), phenoxymethyl penicillin (n: 9), cefdinir (n: 1), and cefixime (n: 1), while there was no reaction in the controlled administration with clindamycin. Alternative treatments were tested in 13 patients with a confirmed ceftriaxone allergy. No adverse reactions were observed in 9 patients who underwent DPT with ACA and in 10 patients who were exposed to clarithromycin under controlled conditions. Finally, 54 of the 80 patients (67.5%) were successfully contacted and none reported a reaction to the alternative drugs. Conclusion: For patients with confirmed BLA, macrolides may be considered as preferred alternatives. In addition, beta-lactams with different side chains may be safe alternatives after diagnostic evaluation, taking into account the risk of cross-reactivity.

Aquaculture oxidant (ClO2) or antibiotic disinfection induces unique bimodal aggregation and boosts exDNA sedimentation: A disinfection-driven great spatial shift of antibiotic resistance risk

ClO2 has been ever-increasingly used as an alternative disinfectant to alleviate antibiotic resistance risk in aquaculture. However, the feasibility of ClO2 disinfection in reducing antibiotic resistance has not been clarified yet. We comparatively explored the aggregation mechanisms and their effect on extracellular DNA (exDNA) partition and settlement in disinfected aquaculture waters and natural waters. In contrast to the unimodal aggregation in natural non-aquaculture waters, a unique bimodal size distribution pattern of micron-sized aggregates was found in aquaculture waters regardless of the disinfectants (macro-aggregates – 200–700 μm in diameter and micro-aggregates – 2–200 μm in diameter). The bimodal aggregates had 2–4 orders of magnitude higher content of Ferron cations and enriched hundred-fold exDNA in aquaculture waters than in natural waters. ExDNA was adsorbed on the surface of aggregates and conglutinated mainly by carbohydrates and coagulative cations. Macro-aggregates had lower fractal dimension but greater sedimentation velocities compared with micro-aggregates. Polylithionite was the key ballast mineral facilitating fast sedimentation of aggregates in aquaculture waters. Loading more antibiotic resistance genes and mobile gene elements, the aquaculture aggregates sank more rapidly from water to sediments than the natural-water aggregates. It indicates that disinfection with ClO2 or antibiotics facilitated the spatial transfer of antibiotic resistance risk with high horizontal transfer potential from water column to sediment through forming bimodal aggregates. These findings imply that the adoption of antibiotic alternatives such as the oxidant of ClO2 is far from sufficient to alleviate antibiotic resistance in aquaculture.

Effects of clindamycin and amoxycillin as prophylaxis against early implant failure: double-blinded randomized clinical trial.

The objective of this randomized controlled clinical trial (RCT) was to compare the frequency of early implant failure, postoperative infection, and pain/inflammation and the degree of implant stability between healthy non-penicillin-allergic individuals receiving a single prophylactic dose of 600mg clindamycin versus 2g amoxicillin at 1h before implant surgery. A single-center double-blinded RCT study with parallel groups was undertaken. Eighty-two patients fulfilled study inclusion criteria and were randomly assigned to the amoxicillin (n = 41) or clindamycin (n = 41) group. The primary outcome variable was early implant failure. The presence of infection was evaluated immediately after surgery and on days 7, 14, 30, and 90, and postoperative pain/inflammation was assessed daily on days 1 to 7 post-surgery. Resonance frequency analysis was used to measure primary and secondary implant stability. One early implant failure was observed (1/81), in a patient from the amoxicillin group. No statistically significant between-group differences were observed in early implant failure rate, postoperative infection rate up to 90 days, pain/inflammation scores during the first week post-surgery, or primary or secondary stability values. A single dose of 600mg clindamycin before implant surgery does not increase the risk of early implant failure or infection. These findings suggest that a single dose of 600mg clindamycin at 1h before implant surgery is a safe antibiotic prophylactic approach; however, when a more prolonged antibiotic therapy is required, it appears advisable to prescribe an alternative antibiotic to avoid adverse effects.

Biochemistry and Future Perspectives of Antibiotic Resistance: An Eye on Active Natural Products.

Antibiotic resistance poses a serious threat to the current healthcare system, negatively impacting the effectiveness of many antimicrobial treatments. The situation is exacerbated by the widespread overuse and abuse of available antibiotics, accelerating the evolution of resistance. Thus, there is an urgent need for novel approaches to therapy to overcome established resistance mechanisms. Plants produce molecules capable of inhibiting bacterial growth in various ways, offering promising paths for the development of alternative antibiotic medicine. This review emphasizes the necessity of research efforts on plant-derived chemicals in the hopes of finding and creating novel drugs that can successfully target resistant bacterial populations. Investigating these natural chemicals allows us to improve our knowledge of novel antimicrobial pathways and also expands our antibacterial repertoire with novel molecules. Simultaneously, it is still necessary to utilize present antibiotics sparingly; prudent prescribing practices must be encouraged to extend the effectiveness of current medications. The combination of innovative drug research and responsible drug usage offers an integrated strategy for managing the antibiotic resistance challenge.

Comparison of Different Antibiotic Alternatives for Safe Broiler Production

The use of growth-promoting antibiotics in broiler feed, once widespread, is now recognized as risky due to antibiotic resistance and residue concerns in meat. To mitigate these risks, the goal of this study was to compare different alternative additives like organic acids, neem, enzymes, and probiotics for producing a safe broiler. A total of 360 Cobb-500-day-old broiler chicks were indiscriminately assigned into six treatment groups, i.e., Control (T1), Basal feed + Antibiotic (T2), Basal feed + Organic acid (T3), Basal feed + Enzyme (T4), Basal feed + Probiotic (T5), and Basal feed + Medicinal plant (T6) having four replications of 15 birds in each. During the experiment, significant differences (P &lt; 0.05) in body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) among the experimental groups were observed only in the 5th week. At the end of the study, the highest BW, BWG, and FCR were found in organic acid, followed by the enzyme, antibiotic, probiotic, neem, and control group. There were no significant differences (P &gt; 0.05) in BW, BWG, and FI among the dietary groups during the 1st, 2nd, 3rd, and 4th weeks. No significant differences (P &gt; 0.05) in meat yield (drumstick meat, thigh meat, wing weight, and breast meat), bone development, and dressing parameters were observed among the dietary groups. Supplementation of different additives significantly (P &lt; 0.05) affects cholesterol and glutamic oxaloacetic transaminase content, whereas HDL, LDL, triglyceride, GPT, and creatinine were not affected among the groups. The neem and organic acid groups had the lowest cholesterol and glutamic oxaloacetic transaminase values, respectively, compared to the others. It can be concluded that supplementing organic acid, probiotics, enzymes, and neem enhanced the growth performance, carcass quality, and blood biochemical profiles of the broilers, potentially serving as antibiotic alternatives. Mainly, the organic acid gives the best results among all the antibiotic alternatives.

Rutin and luteolin purified from Gerbera jamesonii and Chrysanthemum ‘dante purple’ flowers exert remarkable protection against the enteropathogen, E. coli O78, in poultry

Recently, the world directed to the use of natural products as antibiotic alternatives to substitute antibiotics, particularly in livestock animals and poultry to avoid antibiotic resistance and antibiotic residues in all products used for human consumption. Therefore, this study aimed to evaluate in vitro and in vivo antibacterial activities of Gerbera jamesonii and Chrysanthemum “dante purple” flowers extracts as well as rutin and luteolin previously isolated from Gerbera jamesonii and Chrysanthemum “dante purple”, respectively, against the enteropathogen Escherichia coli (E. coli O78) as well as, the detection of their effects on the blood parameters and the clinical signs of the treated birds. Firstly, in vitro antimicrobial activity of the total methanolic extracts, and fractions (petroleum ether or hexane, ethyl acetate and butanol) of Gerbera jamesonii and Chrysanthemum “dante purple” flowers as well as the pure isolated compounds; rutin and luteolin were tested against different pathogens. Further in vivo antimicrobial activity of the pure compounds, rutin and luteolin against E. coli was evaluated. The two pure compounds remarkably protected against the infection induced by the enteropathogen, E. coli O78, in infected chicks. This could prove the efficacy of using the two natural compounds, rutin and luteolin, as protective supplements in poultry.

Pediococcus pentosaceus RC007 and Saccharomyces boulardii RC009 as antibiotic alternatives for gut health in post-weaning pigs.

The aim of the present study was to evaluate a novel probiotic Pediococcus pentosaceus RC007 used alone and convined with Saccharomyces cerevisiae var. boulardii RC009, as in-feed additives to substitute the non-therapeutic use of antibiotics, and evaluate the different structural characteristics of intestinal bacterial populations between groups, correlated with pig production performance. The in vivo study was conducted on post-weaning pigs, from 21 to 56 days-old. Three dietary treatments were included: T1- basal diet (BD - Control group); T2- BD with P. pentosaceus RC007; and T3- BD with a mix of P. pentosaceus RC007 and S. boulardii RC009. The weight gain increase of pigs consuming non-therapeutic antibiotics was similar to those that did not consume antibiotics during the study (p=0.0234), but had better health indicators. The use of a probiotic combination increased carcass weight and significantly reduced the lumbar fat thickness. In terms of taxonomic composition, there was a tendency to modify the abundance of Proteobacteria, Cyanobacteria, Enterobacteriaceae and Lactobacillaceae in pigs that consumed the additives. The genus Butyricicoccus, Collinsella and Ruminococcus tended to be more abundant in the microbiota of pigs at T3. For the first time, the results of the present study indicate that P. pentosaceus RC007 and S. boulardii RC009, a probiotic combination, could be a good substitute for antibiotics in improving pig production performance, while also contributing to a healthier gut microbiota, especially with the reduced abundance of Proteobacteria and Cyanobacteria.

Harnessing the microbiome: probiotics, antibiotics and their role in canine and feline gastrointestinal disease.

Unfavourable alterations of the host microbial environment, known as dysbiosis, have been identified in many canine and feline gastrointestinal (GI) diseases. As a result, normalisation of microbial composition and function has become an important therapeutic target. Given the complex and individualistic interplay between the resident microbiota, host and environment, a multimodal approach is often necessary when addressing dysbiosis in dogs and cats with GI disease. Systemic antibiotics are often empirically used to treat acute and chronic GI diseases. However, with modern genomic techniques demonstrating the profound negative effect antibiotics can have on the GI microbiota and the rapid emergence of resistant bacteria globally, there has been an increased focus on identifying antibiotic alternatives for use in small animal practice. Biotics, such as prebiotics, probiotics and synbiotics, are of growing interest due to their potential supportive effect on the microbiota. This article reviews the evidence for the use of biotics in canine and feline GI disease, highlighting how judicious use of antibiotics and targeted probiotic supplementation can enhance patient outcomes by promoting a balanced gut microbial environment.

Evaluation of the Antimicrobial Effects of Olive Mill Wastewater Extract Against Food Spoiling/Poisoning, Fish-Pathogenic and Non-Pathogenic Microorganisms.

Although antibiotics are the main therapy for bacterial infections, the reports showed that the overuse (or misuse) of antibiotics will results in several problems such as the development of antibiotic-resistant strains, persistence of drug residues, and numerous environmental concerns. Therefore, finding antibiotic alternatives is considered of vital importance. Investigation of the antimicrobial properties of several plant substances and extracts is of great value to replace antibiotics. With this objective, this study aimed to evaluate the antimicrobial activities of an ethanolic extract prepared from olive mill wastewater (OMWW), which is a by-product of olive oil production with considerable environmental burden, against 38 bacterial strains, including fish-associated pathogens, non-pathogenic isolates, collection strains, and one yeast strain, Candida albicans. Disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration (MBC/MFC) tests were used to determine the antimicrobial activity of the OMWWE. According to the results, OMWWE provoked strong inhibitory effects against Shewanella baltica strain SY-S145. It also showed a moderate inhibitory effect on Plesiomonas shigelloides strain SY-PS16 and Vibrio anguillarum strain SY-L24. The MIC and MBC of OMWWE on Shewanella baltica SY-S145, Vibrio gigantis strain C24, and V. anguillarum strain SY-L24 were 500 µg/mL. The MIC and MBC on V. parahaemolyticus ATCC 17802 were 1000 µg/mL, whereas the values for Aeromonas salmonicida ATCC 33658 were 500 µg/mL and 1000 µg/mL, respectively. To put it briefly, the OMWW extract showed high antimicrobial activity and can act as an environmentally friendly additive for the control and prevention of diseases caused by A. veronii, A. hydrophila, P. shigelloides, S. baltica, V. anguillarum, and V. parahaemolyticus. Its active agents also prevented infections of both fish-associated pathogens and food spoiling bacteria, which means it can not only help in the disease control mechanism but also in improving the safety of food by reduction of the microbial contamination.

Antimicrobial Peptide with a Bent Helix Motif Identified in Parasitic Flatworm Mesocestoides corti.

The urgent need for antibiotic alternatives has driven the search for antimicrobial peptides (AMPs) from many different sources, yet parasite-derived AMPs remain underexplored. In this study, three novel potential AMP precursors (mesco-1, -2 and -3) were identified in the parasitic flatworm Mesocestoides corti, via a genome-wide mining approach, and the most promising one, mesco-2, was synthesized and comprehensively characterized. It showed potent broad-spectrum antibacterial activity at submicromolar range against E. coli and K. pneumoniae and low micromolar activity against A. baumannii, P. aeruginosa and S. aureus. Mechanistic studies indicated a membrane-related mechanism of action, and circular dichroism spectroscopy confirmed that mesco-2 is unstructured in water but forms stable helical structures on contact with anionic model membranes, indicating strong interactions and helix stacking. It is, however, unaffected by neutral membranes, suggesting selective antimicrobial activity. Structure prediction combined with molecular dynamics simulations suggested that mesco-2 adopts an unusual bent helix conformation with the N-terminal sequence, when bound to anionic membranes, driven by a central GRGIGRG motif. This study highlights mesco-2 as a promising antibacterial agent and emphasizes the importance of structural motifs in modulating AMP function.

A national survey of first line antibiotic use in neonatal units - and the potential scope for iatrogenic sensorineural hearing loss prevention.

National Institute for Clinical Excellence (NICE) guidance for the management of neonatal sepsis recommends a first-line antibiotic regimen containing an aminoglycoside (gentamicin). Aminoglycoside exposure causes sensorineural hearing loss in individuals with a specific mitochondrial genetic variant (m.1555A>G). This variant can be detected promptly (in <30 min) by a point of care test. NICE does allow for variation in antibiotic regimes depending on local microbiology guidance. As practices can vary, this survey aimed to determine the current use of first-line antibiotic agents within neonatal units and postnatal wards across the UK. A telephone survey was conducted across all neonatal units in the United Kingdom. Responses were requested from a member of the neonatal team experienced in neonatal septic screening processes. One response was recorded per unit. Of the 187 neonatal units, 186 (99%) responded to the survey. One unit declined to participate. The survey results show most neonatal units (93%) and postnatal wards (74%) across the United Kingdom use aminoglycosides as first-line antibiotic agents. Antibiotic regimes varied between different units and between different locations within the same hospital (NICU vs. postnatal wards). In cases where there was a contraindication to aminoglycosides, the most common alternative antibiotic was cefotaxime. Most neonatal units in the UK use an aminoglycoside antibiotic as first-line agent for suspected sepsis. This places infants with the m.1555A>G genetic variant at risk of iatrogenic hearing loss. There needs to be integration of point-of-care genetic testing within the neonatal septic screening pathway.

Consumer acceptance of bacteriophage technology for microbial control

As global concerns and awareness of the threat posed by antimicrobial resistance (AMR) grow, the One Health initiative provides a framework to advance public understanding of and willingness to address AMR. The use of bacteriophages as a non-antibiotic means to control bacterial infections aligns with this framework, but it is unknown whether the use of new antibiotic alternatives, and bacteriophages in particular, will find acceptance among consumers. Within the context of poultry production and consumption, we sampled 1497 Pakistani consumers studying their knowledge of and familiarity with antibiotics, bacteriophages and AMR, whether they perceived AMR as a threat, and their willingness to accept alternative microbial control technologies. Additionally, we tested the impact information about bacteriophages had on the different concepts as well as respondents’ perception of different chicken quality attributes. Using both Probit and Multivariate Probit models we found that familiarity with antibiotics and bacteriophages is significantly associated with the acceptance of alternative microbial control technologies and perceptions of resulting products. Moreover, we find that providing information about the technology does not significantly alter respondent’s perception of most quality attributes.

Anti-inflammatory properties of Bacillus pumilus TS1 in lipopolysaccharide-induced inflammatory damage in broilers

This study investigates whether Bacillus pumilus TS1 improves growth performance and alleviates inflammatory damage in broilers and explored its feasibility as an antibiotic alternative. We divided 240 one-day-old AA308 white-finned broilers into five groups (con, LPS, TS1L + LPS, TS1M + LPS and TS1H + LPS). The TS1L + LPS, TS1M + LPS and TS1H + LPS groups were fed TS1 for 15 days by gavage. The LPS, TS1L + LPS, TS1M + LPS and TS1H + LPS groups were injected intraperitoneally with 1 mg/kg LPS for three days. We investigated the probiotic and anti-inflammatory activities by measuring body weight, sequencing the intestinal flora and examining the structure of tissues by using pathological stain, real-time PCR, Western blotting and immunohistochemical detection. TS1 could improve growth performance and intestinal flora composition, also reduced different organ damage and inflammatory cytokine expression in serum and organs. The mechanism may involve upregulating HSP60 and HSP70 expression, targeting and regulating Nrf2 and P38 MAPK and modulating NF-κB and HO-1 expression at the transcriptional level in different organs. B. pumilus TS1 alleviated Inflammatory injury caused by LPS and attenuated the inflammatory response in broilers, and these effects were achieved through MAPK and Nrf2 regulation of HSPs/HO-1 in different organs. The above results suggested broilers fed with TS1 could release the LPS caused organ damage, and the most suggested dosage was 1.4 × 108 CFU/mL.

Preparation, in vitro and in vivo assessment of novel carvacrol@pro-phytomicelles for the treatment of Salmonella enteritidis infection in mice

In livestock and poultry farming, the use of antibiotics has been abused, which seriously endangers human health. Thus, antibiotic alternatives are urgently needed. The phytochemical carvacrol (CAR) has attracted attention as an antibiotic alternative due to its excellent antibacterial activity and anti-inflammatory activity. However, CAR has high volatility and low water solubility, which seriously affect its antibacterial activity. In this study, two plant-derived small-molecule phytochemicals—glycyrrhizin and rebaudioside A—were selected as nanocarriers for the preparation of a novel solid pro-phytomicelle formulation named as CAR@PP. Using a simple fabrication method, the encapsulation efficiency of CAR reached 98.74 ± 1.14 %. CAR@PP was found to rapidly dissolve in water, resulting in a transparent solution (named as CAR@M) and a 59-fold increase in solubility compared to CAR. CAR@M contained uniform nanoparticles with a particle size, polydispersity index, and zeta potential of 3.52 ± 0.93 nm, 0.17 ± 0.01, and −10.63 ± 0.45 mV, respectively. The in vitro antibacterial activity of CAR@M was evaluated, and the minimum inhibitory concentration for the tested strains was 125–250 μg/ml. The antibacterial mechanisms were found that CAR@M disrupted the bacterial wall and biomembranes and efficiently inhibited bacterial biofilm growth. To the in vivo activity evaluation, treatment with 50 mg/kg CAR@M could effectively improve bacterial liver abscesses, decrease the inflammatory cytokine levels in the liver and cecum, and reduce the bacterial load in the liver and feces in Salmonella enteritidis-infected mice. In conclusion, CAR@PP is a promising alternative to antibiotics in livestock and poultry farming warranting further research.

Antibacterial activity of green synthesized copper oxide nanoparticles against multidrug-resistant bacteria

Using plant extracts in the green synthesis of nanoparticles has become an environmentally acceptable approach. In our study, copper oxide nanoparticles (CuO NPs) were synthesized using ethanolic extracts of Azadirachta indica and Simmondsia chinensis. CuO NP formation was confirmed by the change in color and by UV‒visible spectroscopy (CuO NPs peaked at a wavelength of 344 nm). TEM images confirmed the semispherical shape of the CuO NPs, with particle sizes ranging from 30.9 to 10.7 nm. The antibacterial activity of these NPs was evaluated by using the agar diffusion method against clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Pseudomonas aeruginosa, Acinetobacter spp., Klebsiella pneumoniae, and Stenotrophomonas maltophilia. The minimum inhibitory concentration (MIC) of CuO NPs ranged from 62.5 to 125 µg/ml. In contrast, the antioxidant activity and antibiofilm activity of CuO NPs ranged from 31.1 to 92.2% at 125–500 µg/ml and 62.2–95%, respectively, at 125 –62.5 µg/ml. Our results confirmed that CuO NPs had IC50s of 383.41 ± 3.4 and 402.73 ± 1.86 at 250 µg/mL against the HBF4 cell line. Molecular docking studies with CuO NPs suggested that penicillin-binding protein 4 (PBP4) and beta-lactamase proteins (OXA-48) strongly bind to S. aureus and K. pneumoniae, respectively, with CuO NPs. Our study confirms the promising use of CuO NPs in treating pathogenic bacteria and that CuO NPs could be possible alternative antibiotics. This study supports the pharmaceutical and healthcare sectors in Egypt and worldwide.

Bacteriophage entrapment strategies for the treatment of chronic wound infections: a comprehensive review.

The growing threat of antimicrobial resistance has made the quest for antibiotic alternatives or synergists one of the most pressing priorities of the 21st century. The emergence of multidrug-resistance in most of the common wound pathogens has amplified the risk of antibiotic-resistant wound infections. Bacteriophages, with their self-replicating ability and targeted specificity, can act as suitable antibiotic alternatives. Nevertheless, targeted delivery of phages to infection sites remains a crucial issue, specifically in the case of topical infections. Hence, different phage delivery systems have been studied in recent years. However, there have been no recent reviews of phage delivery systems focusing exclusively on phage application on wounds. This review provides a compendium of all the major delivery systems that have been used to deliver phages to wound infection sites. Special focus has also been awarded to phage-embedded hydrogels with a discussion on the different aspects to be considered during their preparation.

Changes in Microbial Ecosystems and Serum Metabolomics by Diet Supplementation With Enramycin in Weaning Piglets.

Antibiotics are used in swine production for growth promotion and disease prevention, raising concerns about environmental contamination and antibiotic resistance. In this study, we investigated the effects of enramycin supplementation on piglet growth, gut microbiota and blood metabolites. Enramycin promotes piglet growth and temporarily reduces diarrhoea. Gut microbiota analysis revealed changes in microbial composition, including an increase in the abundance of Limosilactobacillus reuteri. Metabolomic analysis has identified elevated levels of dimethylglycine, a known growth-promoting factor, in the enramycin group. Liver gene expression analysis revealed increased mRNA levels of ALDH and dimethylglycine dehydrogenase, which are enzymes involved in dimethylglycine metabolism. The enramycin-treated group had a higher concentration of acetic acid in caecal contents, and their caecal acetic acid concentrations were positively correlated with the abundance of L. reuteri and the content of serum dimethylglycine, respectively. These findings suggest that the promotion effect of enramycin on piglet growth is related to the gut microbiota, blood metabolites and liver gene expression, which provide insights into antibiotic alternatives for swine production.