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The use of supramolecular assemblies in pharmaceuticals has garnered significant interest. Recent studies have shown that the activities of antibacterial agents can be enhanced through complexation with cyclic oligomers and metal ions. Notably, these complexes sometimes possess greater therapeutic properties than the parent drugs. To develop microbiologically potent supramolecular drugs, the complexation of macrocyclic hosts with fluoroquinolone (FQ) antibiotics was investigated. FQs are a successful family of antibiotics that target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, leading to bacterial cell death through the inhibition of DNA synthesis. However, antibiotic resistance resulting from the repeated use of FQs over time has limited their effectiveness against resistant pathogens. To overcome this issue, the encapsulation of FQs in polyphenolic macrocycles was investigated. This study highlights resorcinarene, a polyphenolic host with antibacterial properties, and its ability to chemically interact with FQs. The inclusion complexation process was analyzed using NMR and FTIR techniques. The binding constants determined by 1H-NMR titration revealed that levofloxacin forms more stable complexes with resorcinarene than with β-cyclodextrin, which aligned with MD simulations. Assessment of the geometric characteristics of the inclusion complexes using 2D NMR analysis confirmed that different moieties of various FQs can fit into a single host cavity and improve activity against gram-negative bacteria. Overall, these findings suggest that encapsulation in polyphenolic macrocycles is a promising strategy for utilizing FQs against antibiotic-resistant bacteria. [ABSTRACT FROM AUTHOR]

Background: The World Health Organization (WHO) published in 2017 a global priority pathogens (GPP) list for research and development of effective antibiotics. It is a catalog of bacteria that should be prioritized in the fight against antibiotic resistance. Objective: To collect and assess the scientific evidence on bacteria listed as GPP in animal food products and by-products in Colombia, identifying knowledge gaps and providing evidence-based recommendations. Materials and Methods: This review was conducted following PRISMA guidelines. Only original articles published in peer-reviewed journals were considered. Results: Twenty-one articles published between 2001 and 2021 met the inclusion criteria. The geographical areas of study were in the provinces of Antioquia, Cundinamarca (including Bogotá district), Santander, and Tolima. The main bacteria reported from the WHO's list were fluoroquinolone-resistant Salmonella, methicillinresistant and vancomycin-intermediate and resistant Staphylococcus aureus, and carbapenem-resistant ESBL-producing Enterobacteriaceae. The sources were feces, facilities, equipment, feed, animal drinking water, bedding material, animal tissues, and carcasses from broiler, laying hen, cattle, and pig production systems. Conclusion: Our findings enhance the understanding of the current dynamics of bacterial resistance in Colombia. Nevertheless, several aspects need to be further researched, such as defining standardized methods for microbiological identification in veterinary medicine, as well as evaluating antibiotic susceptibility patterns of bacteria in accordance to what is done in humans, among other aspects. [ABSTRACT FROM AUTHOR]

This study aimed to explore the phytochemical analyses and antibacterial potential of three essential oils (EOs) using both in-vitro and in-silico experiments for drug discovery. The Eos of Rosmarinus officinalis, Lavandula angustifolia , and Salvia officinalis were extracted by hydrodistillation, and GC–MS determined the chemical composition. The antibacterial activities of each EO were studied by the disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these EOs were determined by micro-dilution. In addition, the EOs were combined with ineffective antibiotics (Aztreonam et al.) against clinical bacteria (P. aeruginosa and K. pneumoniae) to determine this association's effect. The in-vitro toxicological study was based on the MTT cytotoxicity assay. Finally, in-silico methods were employed to estimate their possible antibacterial mechanisms. Molecular docking was performed to calculate the predictive binding affinities of five major volatile components to three proteins key in the bacterial cycle using the AutoDock Vina program; prediction of drug-likeness properties and Toxicity prediction were carried out respectively by SwissADME and ProToxII online server. The results showed that the three EOs possessed antibacterial activity against ATCC and clinical K. pneumoniae. We note that P. aeruginosa was resistant to lavender and sage EOs. Surprisingly, adding EOs to antibiotics ineffective against resistant bacteria showed a significant synergistic antibacterial effect. Cytotoxicity assay of essential oils showed different values ranging from 0.22 to 0.43 µL/mL. Finally, the molecular docking study revealed that both compounds (1,8-Cineol, 1-Dodecene, Linalool, cis-Thujone, and Camphor) from the three EOs have a significant potential to inhibit the protein target involved in bacteria resistance. Furthermore, the SwissADME prediction results showed that all five components satisfy the rule of five and exhibit acceptable drug-like characteristics. findings suggest that the three EOs have interesting antibacterial activity. The in-vitro and in-silico studies gave a great potentiation and may constitute a promising option to control the emergence of MDR P. aeruginosa and K. pneumoniae. [ABSTRACT FROM AUTHOR]

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With the widespread use of tetracycline antibiotics (TCs) and the application of manure fertilizer in farmland, TCs and their metabolites especially 4-epimers have been heavily detected in agricultural soil. However, existing studies have focused on the residual and environmental behavior of maternal TCs, and few studies have looked at the ecotoxicity of their 4-epimers in soil. In this study, the degradation and interconversion of tetracycline (TC), oxytetracycline (OTC) and their 4-epimers (4-epitetracycline, ETC; 4-epioxytetracycline, OTC) were revealed. Their effects on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and bacterial community in soil were also investigated in comparison. The results showed that the 4-epimers could be substantially transformed to their parents and degraded as a whole. The degradation rates of four selected pollutants are followed: TC > OTC > ETC > EOTC. This indicated that when TCs entered the soil, part of TCs transformed into slower-degraded 4-epimers, and these 4-epimers could also be converted back to their antibiotic parents, causing the long-term residue of TCs in soil. When added to the soil alone, TC and OTC significantly promoted the proliferation of most ARGs and MGEs, among them, trb-C, IS1247 and IS1111 were the top three genes in abundance. ETC and EOTC had little effect at the beginning. However, as the 4-epimers continuously converted into their parents after one month of cultivation, ETC and EOTC treatments showed similar promoting effect on ARGs and MGEs, indicating that the effect of ETC and EOTC on soil resistome was lagged and mainly caused by their transformed parents. Nocardioides, unclassified_Rhizobiaceae, norank_Sericytochromatia, Microlunatus, Solirubrobacter and norank_67-14 were the most frequent hosts of ARGs, Most of which belong to the phylum Actinobacteria. Due to their large transformation to TCs, slow degradation rate and potential effects on soil microbes and ARGs, the harm of TCs’ 4-epimers on soil ecosystem cannot be ignored.

The menace of microbial resistance and re-emerging disease is still a problem for healthcare givers globally, and the need for newer sources of potent antibiotics has become paramount. This study investigated the antimicrobial and antiulcer activities of Streptomyces isolate SOM013. Streptomyces isolates were cultivated and purified following standard microbiological protocols. Secondary metabolites were recovered and characterized from Streptomyces isolate SOM013 via broth fermentation and extraction. Varying concentrations (0.5 mg/mL, 0.025 mg/mL and 0.0125 mg/mL) of the SOM013 extract were used for antimicrobial screening against resistant bacteria and medically important fungi (methicillin-resistant Escherichia coli, Oxacillin resistant Helicobacter pylori, Shigella spp, extended broad-spectrum resistant Pseudomonas aeruginosa, Streptococcus spp, Campylobacter spp, Candida albicans, Aspergillus niger, and Aspergillus flavus). The antiulcer activity of the SOM013 was also examined in a methanol-induced gastric ulcer animal model. A total of 23 Streptomyces spp were recovered from the study. Methanolic extract of the SOM013 isolates was more potent across the clinical test microorganisms compared to water extract. The antimicrobial activity was dose dependent, with methanolic extract at 0.05 g/mL displaying the highest zone of inhibition (18.8 ± 0.3 mm) when tested against extended broad-spectrum resistant Pseudomonas aeruginosa. Further, the extract's ulcer index and protection efficacy were significant as the concentration increased (P

Antimicrobial photodynamic treatment (aPDT) is a photooxidative process based on the excitation of a photosensitizer (PS) in the presence of molecular oxygen, under specific wavelengths of light. It is a promising method for advanced treatment of water and wastewater, particularly targeting disinfection challenges, such as antibiotic-resistant bacteria (ARB). Research in improved aPDT has been exploring new PS materials, and additives in general. Hydrogen peroxide (H2O2) a widely applied disinfectant, mostly in the food industry and clinical settings, present environmentally negligible residuals at the usually applied concentrations, making it friendly for the water and wastewater sectors. Here, we explored the effects of preoxidation with H2O2 followed by blue light-mediated (450 nm) aPDT using curcumin (a natural-based PS) against methicillin-resistant Staphylococcus aureus (MRSA). Results of the sequential treatment pointed to a slight hampering in aPDT efficiency at very low H2O2 concentrations, followed by an increasing cooperative effect up to a deleterious point (≥7 log10 inactivation in CFU mL–1), suggesting a synergistic interaction of preoxidation and aPDT. The increased performance in H2O2-pretreated aPDT encourages studies of optimal operational conditions for the assisted technology and describes potentials for using the described strategy to tackle the issue of ARB spread. HIGHLIGHTS Preoxidation with H2O2 followed by aPDT led to absence of planktonic MRSA.; Preincubation with H2O2 did not damage curcumin as analyzed by UV–Vis spectroscopy.; A cooperative effect was obtained for the sequential treatment.;

In the middle of the late century, the concept of medicine has been reshaped and reformed by the discovery of antibiotics. Untreatable infectious diseases have become treatable, However, with time microbes adapt to resist the antibiotic treatments due to their enormous adaptive ability. Therefore, new antibiotics were required to combat these resistant bacteria. But the enormous adaptive ability of bacteria has turned the next generation of antibiotics obsolete. Thus, Nanoparticles play a crucial role due to their antibacterial activity. Besides, these can act as carriers for various antibiotics to increase their efficiency against superbugs. The current review provides an in-depth overview of nanoparticles, their biosynthesis, antibacterial activity, and synergistic effects with various antibiotics. [ABSTRACT FROM AUTHOR]

The overuse and misuse of antibiotics to treat diseases and promote the growth of animals lead to the deposition of antibiotics in animal tissues, and subsequently, antibiotics come into the human body through the food chain. In this paper, comparative studies on antibiotic residue (AR) in foodstuffs from animal source and human health risks are reviewed in detail. The early part of this review is focused on the use of different veterinary antibiotics in animal farms and the marine environment as a reservoir of ARs. Later on, ARs in foodstuffs, including meat, milk, and marine foods have been comprehensively discussed. Review studies on human health issues associated with antibiotics show that people from poor and developing countries are the most vulnerable to infectious diseases caused by antibiotic-resistant bacteria. At the end of the review, some alternative approaches that include the use of phytogenic feed additive, organic acid, probiotic, prebiotic, and other substances are summarized, considering their potential exposure to replace antibiotics as growth promoters and mitigate the prevalence of antibiotic-resistant genes. [ABSTRACT FROM AUTHOR]

Antimicrobial photodynamic treatment (aPDT) is a photooxidative process based on the excitation of a photosensitizer (PS) in the presence of molecular oxygen, under specific wavelengths of light. It is a promising method for advanced treatment of water and wastewater, particularly targeting disinfection challenges, such as antibiotic-resistant bacteria (ARB). Research in improved aPDT has been exploring new PS materials, and additives in general. Hydrogen peroxide (H2O2) a widely applied disinfectant, mostly in the food industry and clinical settings, present environmentally negligible residuals at the usually applied concentrations, making it friendly for the water and wastewater sectors. Here, we explored the effects of preoxidation with H2O2 followed by blue light-mediated (450 nm) aPDT using curcumin (a natural-based PS) against methicillin-resistant Staphylococcus aureus (MRSA). Results of the sequential treatment pointed to a slight hampering in aPDT efficiency at very low H2O2 concentrations, followed by an increasing cooperative effect up to a deleterious point (-7 log10 inactivation in CFU mL-1), suggesting a synergistic interaction of preoxidation and aPDT. The increased performance in H2O2-pretreated aPDT encourages studies of optimal operational conditions for the assisted technology and describes potentials for using the described strategy to tackle the issue of ARB spread. [ABSTRACT FROM AUTHOR]

Nosocomial infection is acquired contamination of hospitals and health care units caused by multidrug resistant bacteria. Currently, bacterial resistance to antimicrobial medication represents a complicated public health problem. Recent studies on the antimicrobial activity of silver nanoparticles (AgNPs) attracted researchers worldwide to focus on the safe synthesis of AgNPs as antimicrobial agents against multidrug resistant bacteria. The antimicrobial efficacy of AgNPs on pathogenic bacteria isolated from clinical cases of acquired hospital infection was targeted in this project. Fifty specimens of stool were collected through private laboratories in Baghdad from patients who suffered diarrheal symptoms. Bacterial isolation, identification, and characterization via culturing on MacConkey agar, Salmonella shigella agar, and IMVic analysis were done besides, using polymerase chain reaction (PCR) through amplifying inf B gene for molecular characterization. The obtained isolates were tested for antimicrobial sensitivity via disk diffusion assay against; Gentamycin, Amoxicillin, Tetracycline, Ceftriaxone and a suspension of silver nanoparticles (1mM AgNo3 reduced by 1% tri-sodium citrate). Results of isolation and IMVic showed the obtained isolates were Klebsiella spp., Enterobacter spp., Citrobacter spp., and PCR assay confirmed their pathogenicity. Disc diffusion assay showed the sensitivity of the isolates (mm); Gentamycin (24.94 ± 0.1), Amoxicillin (2.11 ± 0.13), Tetracycline (12.15 ± 0.1), Ceftriaxone (12.35 ± 0.1). Whereas, all isolates are sensitive to AgNPs (24.12 ± 0.3). This result of the antimicrobial effect of AgNPs on nosocomial infection promises for developing AgNPs solution as a product used in the sterilization of furniture, floors and hospital water cycles

The presence of macrophytes in constructed wetlands (CW) applied within the concept of nature-based solution (NBS) is crucial. Besides their role in the phytoremediation of pollutants, the cultivated plants, if properly selected, can also produce a range of bioactive compounds, including those with potential inhibitory effects against pathogenic bacteria. Bioactive compounds, such as flavonoids and ellagitannins, known for their remarkable antimicrobial properties, offer a sustainable solution to the global challenge of antibiotic resistance. In this study, we investigated macrophyte species adapted to the water variations in the Pantanal region (flood and dry seasons), focusing on those with both antimicrobial and ornamental potential, that could improve the ability of a CW system to treat greywater. Seven different macrophyte species were collected, cultivated, and evaluated for their antimicrobial activity (AA) against five standard bacterial strains and five multidrug-resistant clinical bacterial strains. Extracts from the leaf, stem, and root of Polygonum acuminatum showed the best AA against clinical multidrug-resistant strains of Staphylococcus aureus, Enterococcus faecium, and Escherichia coli, with minimum inhibitory concentration (MIC) values ranging from 78.13 to 312.5 µg.mL−1. Furthermore, the leaves of Ludwigia lagunae and P. acuminatum also showed considerable AA against standard strains of Enterococcus faecalis (MIC = 19.5 and 39.06 µg.mL−1, respectively) and Pseudomonas aeruginosa (MIC = 156.25 µg.mL−1 for both). High-Performance Liquid Chromatography with Ultraviolet and Mass Spectrometry analysis of these extracts identified important bioactive compounds, including flavonoids (quercetin 3-rhamnoside, hydropiperoside, quercetin 3-O-rutinoside, quercetin, myricetin 3-O-rhamnoside, kaempferol 3-O-rhamnoside, formononetin, and calycosin) and ellagitannins (3,3′4-tri-O-methylelagic acid, galloys-HHDP-glucose, and ellagic acid), along with other bioactive compounds. These results indicate that P. acuminatum and L. lagunae hold potential for application in CW owing to their antimicrobial property, local adaptability, and ornamental appeal.

ABSTRACT: Objectives: Antimicrobial resistance (AMR) is a global challenge that has raised concern globally, owing to its detrimental effects on the health and economy of countries. The ever-growing threat of AMR and sources of AMR are still being investigated. Wastewater plays an important role as a habitat for bacteria and an environment conducive to gene transfer. The primary aim of this review was to highlight the contribution of wastewater to AMR. Methods: Evidence of AMR in wastewater was drawn from literature published in the last 10 years, from 2012 to 2022. Results: Wastewater from agricultural practices, pharmaceutical manufacturing plants, and hospital effluents was established to promote AMR. Furthermore, stress factors such as the presence of antibiotics, heavy metals, pH, and temperature initiate and propagate AMR in bacteria living in wastewater. AMR in bacteria from wastewater was established to be either natural or acquired. Wastewater treatment techniques such as membrane filtration, coagulation, adsorption, and advanced oxidation processes have been used to remove resistant bacteria with varying success levels. Conclusion: Wastewater is a major contributor to AMR, and an understanding of its role in AMR is necessary to find a lasting solution. In this regard, the spread of AMR in wastewater should be considered a threat that requires a strategy to stop further damage.

The search for efficient antimicrobial therapies that can alleviate suffering caused by infections from resistant bacteria is more urgent than ever before. Infections caused by multi-resistant pathogens represent a significant and increasing burden to healthcare and society and researcher are investigating new classes of bioactive compounds to slow down this development. Antimicrobial peptides from the innate immune system represent one promising class that offers a potential solution to the antibiotic resistance problem due to their mode of action on the microbial membranes. However, challenges associated with pharmacokinetics, bioavailability and off-target toxicity are slowing down the advancement and use of innate defensive peptides. Improving the therapeutic properties of these peptides is a strategy for reducing the clinical limitations and synthetic mimics of antimicrobial peptides are emerging as a promising class of molecules for a variety of antimicrobial applications. These compounds can be made significantly shorter while maintaining, or even improving antimicrobial properties, and several downsized synthetic mimics are now in clinical development for a range of infectious diseases. A variety of strategies can be employed to prepare these small compounds and this review describes the different compounds developed to date by adhering to a minimum pharmacophore based on an amphiphilic balance between cationic charge and hydrophobicity. These compounds can be made as small as dipeptides, circumventing the need for large compounds with elaborate three-dimensional structures to generate simplified and potent antimicrobial mimics for a range of medical applications. This review highlight key and recent development in the field of small antimicrobial peptide mimics as a promising class of antimicrobials, illustrating just how small you can go.

Vanadium (V) contamination in soil has received extensive attention due to its high toxicity. The change of mobility and bioavailability of soil V and the effects of V on the soil microbial community were studied under conditions of different V(V) spiking concentrations (0, 100, 250, and 500 mg kg−1) and aging time (1, 7, 14, 30, 45, and 60 d). The results showed that soil V mainly presented as V(IV) of all treatments throughout the aging process. At high levels of V(V) loading (250 and 500 mg kg–1), soil V(V) showed a downward trend, while bioavailable V did not change significantly within 60 d’s aging. The analysis of soil bacterial community showed that Proteobacteria was the most abundant phylum in all soils, and the dominant genera Sphingomonas and Lysobacter can well adapt to high concentration V. These microorganisms exhibited great potential for bioremediation of V-contaminated soils. [ABSTRACT FROM AUTHOR]

To understand which type of hospital waste may contain the highest amount of antibiotic resistant microorganisms that could be released into the environment, the bacterial strains entering and leaving a hospital wastewater treatment plant (HWTP) were identified and tested for their antibiotic susceptibility. To achieve this goal, samples were collected from three separate sites, inlet and outlet wastewater positions, and sludge generated in a septic tank. After microbiological characterization according to APHA, AWWA, and WEF protocols, the relative susceptibility of the bacterial strains to various antibiotic agents was assessed according to the Clinical and Laboratory Standards Institute guidelines, to determine whether there were higher numbers of resistant bacterial strains in the inlet wastewater sample than in the outlet wastewater and sludge samples. The results showed more antibiotic resistant bacteria in the sludge than in the inlet wastewater, and that the Enterobacteriaceae family was the predominant species in the collected samples. The most antibiotic-resistant families were found to be Streptococcacea and non-Enterobacteriaceae. Some bacterial strains were resistant to all the tested antibiotics. We conclude that the studied HWTP can be considered a source of resistant bacterial strains. It is suggested that outlet water and sludge generated in HWTPs should be monitored, and that efficient treatment to eliminate all bacteria from the different types of hospital waste released into the environment is adopted. [ABSTRACT FROM AUTHOR]

Antibiotic resistance challenges the treatment of bacterial biofilm-related infections, but the use of nanoparticles as a treatment is a promising strategy to overcome bacterial infections. This study applied nitrogen-doped titanium dioxide (N–TiO2) conjugated with folic acid (FA) on biofilm-forming resistant bacteria. The photocatalytic effect of TiO2 nanoparticles (NPs) was studied under ultraviolet (UV), visible light, and dark conditions at 60, 120, and 180 min against planktonic cells and biofilms of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. TiO2 NPs were in the anatase phase, spherical shaped with sizes of 10-13 nm, and effectively doped and conjugated with N and FA. The FA-conjugated nanoparticles (N–TiO2-FA and FA-TiO2) were shown to have a bactericidal effect on all bacteria between 60 and 180 min under UV and visible light conditions. Concerning biofilms, N–TiO2-FA was shown to have a highly disruptive effect on all bacterial biofilms under UV irradiation at 180 min. Meanwhile, the nanoparticles did not show DNA damaging potential and they had no cytostatic effect, indicating that these NPs are biocompatible. In sum, nanoparticle conjugation with FA promoted photocatalytic effectiveness, revealing the promise this nanomaterial holds as a biocompatible antimicrobial agent.

Post-wound infections have remained a serious threat to society and healthcare worldwide. Attempts are still being made to develop an ideal antibacterial wound dressing with high wound-healing potential and strong antibacterial activity against extensively drug-resistant bacteria (XDR). In this study, a biological-based sponge was made from decellularized human placenta (DPS) and then loaded with different concentrations (0, 16 µg/mL, 32 µg/mL, 64 µg/mL) of an antimicrobial peptide (AMP, CM11) to optimize an ideal antibacterial wound dressing. The decellularization of DPS was confirmed by histological evaluations and DNA content assay. The DPS loaded with different contents of antimicrobial peptides (AMPs) showed uniform morphology under a scanning electron microscope (SEM) and cytobiocompatibility for human adipose tissue-derived mesenchymal stem cells. Antibacterial assays indicated that the DPS/AMPs had antibacterial behavior against both standard strain and XDR Acinetobacter baumannii in a dose-dependent manner, as DPS loaded with 64 µg/mL showed the highest bacterial growth inhibition zone and elimination of bacteria under SEM than DPS alone and DPS loaded with 16 µg/mL and 32 µg/mL AMP concentrations. The subcutaneous implantation of all constructs in the animal model demonstrated no sign of acute immune system reaction and graft rejection, indicating in vivo biocompatibility of the scaffolds. Our findings suggest the DPS loaded with 64 µg/mL as an excellent antibacterial skin substitute, and now promises to proceed with pre-clinical and clinical investigations. [ABSTRACT FROM AUTHOR]

Pharmaceutical compounds have been introduced into the aquatic ecosystems in multiple ways and sources, which negatively affects the health of the environment and humans. The river near the hospital sewage disposal is host environments for pharmaceuticals resistance bacteria (PRB). In this context, the aim of the research is to detect the presence of pharmaceuticals in hospital wastewater, after treatment, at river point followed by isolation bacteria and test for resistant pharmaceutical compound. Fifteen species of bacteria isolated by angiogenic methods were identified and tested using the well diffusion test to determine the resistance of selected bacteria to ibuprofen by survival assessment. This study showed that ibuprofen detected by GC-mass was available in all selected points at a concentration of 3 to 120 mg/L. Lecuco. mesen.cremris and Koc.rosea have a high ability to break down ibuprofen compound. Thus, the bacteria isolated from hospital wastewater can biologically crack ibuprofen.

The COVID-19 pandemic led to tremendously use of antimicrobial due to the lack of proper treatment strategies, raising concerns about emergence of antimicrobial resistance (AMR). This study aimed at determining the prevalence and antibiotic resistance pattern of selected bacteria isolates in 02 referral health facilities in Yaoundé before and during the COVID-19 pandemic era. We conducted a retrospective study over a period of 03 years (from 1 January 2019 to 31 December 2021) in the bacteriology units of the Central and General Hospitals of Yaoundé, Cameroon. Data on bacteria genera (Streptococcus, Staphylococcus, Neisseria meningitidis and Enterobacteriaceae) as well as their corresponding specifics antibiotics: Cefixime, azythromycin and erythromycin were obtained from laboratory records. The global resistance rate of bacteria as well as their correlation with antibiotics according to COVID-19 pandemic era was determined and compared. For p < 0.05, the difference was statistically significant. In all, 426 bacterial strains were included. It appeared that the highest number of bacteria isolates and lowest rate of bacterial resistance were recorded during the pre-COVID-19 period in 2019 (160 isolates vs. 58.8% resistance rate). Conversely, lower bacteria strains but greater resistance burden were recorded during the pandemic era (2020 and 2021) with the lowest bacteria amount and peak of bacteria resistance registered in 2020, the year of COVID-19 onset (120 isolates vs. 70% resistance in 2020 and 146 isolates vs. 58.9% resistance in 2021). In contrast to almost all others groups of bacteria where the resistance burden was quite constant or decreasing over years, the Enterobacteriaceae exhibited greater resistance rate during the pandemic period [60% (48/80) in 2019 to 86.9% (60/69) in 2020 and 64.5% (61/95) in 2021)]. Concerning antibiotics, unlike erythromycin, azythromycin related resitance increased during the pandemic period and the resistance to Cefixim tends to decrease the year of the pandemic onset (2020) and re-increase one year therafter. A significant association was found between resistant Enterobacteriaceae strains and cefixime (R = 0.7; p = 0.0001) and also, between resistant Staphylococcus strains and erythromycin (R = 0.8; p = 0.0001). These retrospective data showed a herogeneous MDR bacteria rate and antibiotic resistance pattern over time before and during the COVID-19 pandemic era suggesting that antimicrobial resistance needs to be more closely monitored. [ABSTRACT FROM AUTHOR]

ATP, the power of all cellular functions, is constantly used and produced by cells. The enzyme called ATP synthase is the energy factory in all cells, which produces ATP by adding inorganic phosphate (Pi) to ADP. It is found in the inner, thylakoid and plasma membranes of mitochondria, chloroplasts and bacteria, respectively. Bacterial ATP synthases have been the subject of multiple studies for decades, since they can be genetically manipulated. With the emergence of antibiotic resistance, many combinations of antibiotics with other compounds that enhance the effect of these antibiotics have been proposed as approaches to limit the spread of antibiotic-resistant bacteria. ATP synthase inhibitors, such as resveratrol, venturicidin A, bedaquiline, tomatidine, piceatannol, oligomycin A and N,N-dicyclohexylcarbodiimide were the starting point of these combinations. However, each of these inhibitors target ATP synthase differently, and their co-administration with antibiotics increases the susceptibility of pathogenic bacteria. After a brief description of the structure and function of ATP synthase, we aim in this review to highlight therapeutic applications of the major bacterial ATP synthase inhibitors, including animal's venoms, and to emphasize their importance in decreasing the activity of this enzyme and subsequently eradicating resistant bacteria as ATP synthase is their source of energy. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic bacterium that has drawn attention due to its resistance to carbapenem antibiotics. The treatment of patients with severe infections has been challenging. Thus, silver nanoparticles (AgNPs) have been applied for their antimicrobial effects. This work aims to analyze the synergistic effect of the carbapenem antibiotic Imipenem with AgNPs against different susceptibility clinical profiles of K. pneumoniae. The silver nanoparticles were synthesized by bottom-up methodology and capped with alpha-lipoic acid. Susceptibility tests were performed using four K. pneumoniae strains with different susceptibility profiles to Imipenem. The strains were induced to form a biofilm for 48 h. Crystal violet and Resazurin assays were performed to determine biofilm formation and minimal inhibitory concentration, respectively. The reduction in Imipenem concentration with the association of nanoparticles was found in all strains studied in planktonic form, and the synergism between silver nanoparticles and Imipenem was demonstrated through the analysis of the fractional inhibitory concentration index. The viability percentage was reduced at rates ≥80% in the biofilm analysis, characterized by the minimal biofilm inhibitory concentration. The study's proposed association resulted in inhibitory effects on different K. pneumoniae profiles, both in planktonic forms and biofilm, with peculiar behavior in the Imipenem-resistant profile. [ABSTRACT FROM AUTHOR]

The growing concern about the emergence of increasingly antibiotic-r4esistant bacteria imposes the need to search and develop drugs to combat these microorganisms. This, combined with the search for low-cost synthesis methods, was the motivation for the elaboration of this work. Abietic acid present in the resin of Pinus elliotti var. elliotti was used to generate a sodium salt by salification. The synthesis route was low-cost, consisting of only two reaction steps at mild temperatures without toxic organic solvents, and eco-friendly and easy to conduct on an industrial scale. Sodium abietate (Na-C20H29O2) was characterized by mass spectrometry, infrared spectroscopy, elemental analysis, X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. To perform the antimicrobial tests, the determination of minimum inhibitory concentration and the disk diffusion assay was performed. The results obtained showed that the salt Na abietate performed an antimicrobial action against the bacterial strains S. aureus, E. coli, L.monocytogenes, and S. enterica Typhimurium and the yeast C. albicans. The disk diffusion test showed a high inhibition potential against S. enterica compared to the standard antimicrobial tetracycline, as an inhibition index of 1.17 was found. For the other bacterial strains, the inhibition values were above 40%. The MIC test showed promising results in the inhibition of E. coli, L. monocytogenes, and C. albicans, indicating bacteriostatic activity against the first microorganism and bactericidal and fungicidal activities against the others. Therefore, the results showed the action of Na abietate as a possible effective antimicrobial drug, highlighting its sustainability within a circular economy. [ABSTRACT FROM AUTHOR]

In the present study, we investigated in vitro the antimicrobial activity of the pygidial gland secretion of the guanophilic ground beetle Laemostenus (Pristonychus) punctatus (Dejean, 1828) and some of its chemicals against resistant and non-resistant bacteria and Candida species, the synergistic and additive potential of combinations of selected chemicals and antimicrobial drugs against resistant bacterial and fungal strains, anti-adhesive and anti-invasive potential of the secretion and formic acid alone and in selected combinations with antimicrobial drugs against methicillin-resistant Staphylococcus aureus (MRSA) toward spontaneously immortalized human keratinocyte cell line (HaCaT cells). In addition, we examined the antiproliferative activity of the secretion and formic acid in vitro. The tested secretion and the standards of formic and oleic acids possessed a significant level of antimicrobial potential against all tested strains (P < 0.05). The isolate from guano Pseudomonas monteilii showed the highest resistance to the secretion and formic acid, while MRSA achieved a significantly high level of susceptibility to all agents tested, particularly to the combinations of formic acid and antibiotics, but at the same time showed a certain level of resistance to the antibiotics tested individually. Candida albicans and C. tropicalis were found to be the most sensitive fungal strains to the secretion. Formic acid (MIC 0.0005 mg/mL) and gentamicin (MIC 0.0010 mg/mL) in the mixture achieved synergistic antibacterial activity against MRSA (FICI = 0.5, P < 0.05). The combination of formic acid, gentamicin and ampicillin accomplished an additive effect against this resistant bacterial strain (FICI = 1.5, P < 0.05). The secretion achieved a better inhibitory effect on the adhesion ability of MRSA toward HaCaT cells compared to formic acid alone, while formic acid showed better results regarding the invasion (P < 0.001). The combinations of gentamicin and ampicillin, as well as of formic acid and gentamicin and ampicillin achieved similar anti-adhesive and anti-invasive effects, with a slight advantage of formic acid and antibiotics in combination (P < 0.001). The secretion and formic acid were found to be non-toxic to HaCaT cells in vitro (IC50 ≥ 401 μg/mL).

Degefa Dhengesu,1 Hailu Lemma,1 Lechisa Asefa,1 Dagnamyelew Tilahun2 1Department of Environmental Health, Institute of Health, Bule Hora University, Bule Hora Town, Oromia, Ethiopia; 2Department of Medical Laboratory, Institute of Health, Bule Hora University, Bule Hora Town, Oromia, EthiopiaCorrespondence: Degefa Dhengesu, Department of Environmental Health, Institute of Health, Bule Hora University, P.O. Box 144, Bule Hora Town, Oromia, Ethiopia, Tel +251-912-090-879, Email Degefad@gmail.comBackground: Antimicrobial resistance bacteria and unsafe water are contributing to the growing burden of diseases. Hence, isolation and antimicrobial susceptibility tests for drinking water samples are currently becoming vital to address the human health risks from drinking unsafe water.Objective: This study aimed to assess the antimicrobial resistance profile of Enterobacteriaceae and quality of drinking water among households in Bule Hora Town, South Ethiopia.Methods and Materials: A community-based cross-sectional study was used from June to August 2021. A total of 75 water samples were collected and analyzed at the Microbiological Laboratory of Bule Hora University within 6 hours. A membrane filtration method and biochemical tests were used for the isolation and identification of bacteria. An antimicrobial susceptibility test was performed using Kirby–Bauer disc-diffusion method on Mueller–Hinton Agar. Systematic and simple random probability sampling techniques were used to draw representative samples. The data were entered into Epi Data 3.1 and then exported to SPSS version 25 where univariate and bivariate analyses of the data were conducted.Results: This study indicated that 59 (78.6%), 30 (40%), and 20 (26.6%) of water samples from the storage of households were contaminated with total coliforms, thermo-tolerant coliforms, and Escherichia coli, respectively. Similarly, Salmonella accounted for 18 (24%), Shigella 12 (16%), and other members of the Enterobacteriaceae such as Proteus, Citrobacter, Klebsiella, Escherichia coli, and Enterobacter species were also isolated. All isolates of Enterobacteriaceae showed resistance to amoxicillin plus clavulanic acid and ampicillin. Besides, Shigella showed 10 (83.3%), 2 (16.6%) and 10 (83.3%) and Salmonella showed 16 (88.9%), 5 (27.8%) and 15 (83.3%) resistant to cotrimoxazole, chloramphenicol and tetracycline, respectively. All the tested drinking water samples had no free chlorine at all at point of use.Conclusion: There was contamination of drinking water with coliform and antibiotic-resistant Enterobacteriaceae in most surveyed households.Keywords: antimicrobial agents, resistant bacteria, coliform, drinking water

Resistance of bacterial pathogens to conventional antibiotics has remained a significant challenge in managing post-wound infections, especially in developing countries. Here, a nanofibrous chitosan/poly (vinyl alcohol) (CS/PVA) mat was designed for controlled delivery of three different concentrations of two antibiotics (colistin/meropenem ratio of 32/64 μg/ml (AB1), 64/128 μg/ml (AB2), and 128/256 (AB3) μg/ml) with synergistic antibacterial activity against ATCC and extensively drug-resistant (XDR) Acinetobacter baumannii clinical isolates. The scaffolds showed a uniform fibrous structure with no bead formation with a sustained release of the antibiotics for one week. The elongation at break, wettability, porosity, and average fiber diameter decreased with increased antibiotics concentrations. Young's modulus and tensile strength showed a significant increase after adding antibiotics. All the constructs showed excellent in vitro cytocompatibility for fibroblasts and biocompatibility in an animal model. The antibacterial assays confirmed the dose-dependent antibacterial activity of the CS/PVA. The scaffolds loaded with AB2 and AB3 showed biocidal properties against ATCC, while only CS/PVA/AB3 had antibacterial activity against XDR clinical isolates. This study suggests the CS/PVA/AB3 nanofibrous scaffold contained 128/256 μg/ml colistin/meropenem as an excellent antibacterial wound dressing for protection of skin wounds from XDR clinical isolates and now promises to proceed with pre-clinical investigations. [Display omitted] • Optimization of synergistic antibiotics-loaded CS/PVA nanofibrous mat • Optimization of dual (colistin-meropenem) antibiotics release behavior • Optimization of antibacterial activity against drug resistant bacteria • In vitro and in vivo biocompatibility of antibacterial CS/PVA nanofibers • Optimal meropenem/colistin- loaded CS/PVA is suitable for infected wounds therapy. [ABSTRACT FROM AUTHOR]

The reuse of household greywater is increasing globally. Wastewater and greywater treatment processes are not fully effective in removing all contaminants, such as emerging micropollutants, antimicrobial-resistant bacteria, and antibiotic resistance genes. The dynamics between emerging micropollutants and antibiotic resistance genes in greywater treatment systems are complex. Thus, this review aims to analyze the current knowledge on sources, spread, and the fate of emerging micropollutants, antibiotic-resistance genes, and antimicrobial-resistant bacteria in microbial communities of greywater and downstream recipients. The fate of antimicrobial resistance and emerging micropollutants from greywater in the environment has not been determined. More studies are needed to identify the mechanism/s involved in the degradation of emerging micropollutants and the presence of transformation pathways in the microbial metagenome. In the review, we aim to describe the link between the persistence of emerging micropollutants and the emergence of antimicrobial resistance. We showed that the effect of irrigation with treated wastewater was variable. In addition, we tried to summarize the impact of emerging micropollutants on bacteria and their fate in the soil microbiome, demonstrating that emerging micropollutants induce changes in the diversity of soil bacteria. The fate and transport of emerging micropollutants, antimicrobial-resistant bacteria, and antibiotic resistance genes can vary with soil properties. It is, therefore, necessary to better understand how widely antibiotic-resistance genes are disseminated. [ABSTRACT FROM AUTHOR]

Currently, one of the priorities of the World Health Organization is antibiotic-resistant bacteria. Bacteria have a great capacity for dissemination and make it difficult to treat infectious diseases. It is known that they have high morbidity and mortality worldwide, which is considered a global public health problem. The objective is to carry out a documentary review of the latest generation antimicrobials, which may constitute a therapeutic alternative. An analysis of the information available and documented in the scientific literature consulted was carried out. The sampling was carried out between the years 2015-2022, to cover the last years. Google academic, PubMed and MDPI search engines were used as an infotechnology tool. At present there are new antibiotic alternatives among which are Ceftolozano-tazobactam, Ceftazidime-avibactam, Ceftaroline, Ceftobiprole, Dalbavancin, Telavancin, Tedizolid, Omadacycline, Delafloxacin and Lefamulin. Also, the use of peptides that have activity against bacterial, fungal or viral infections was confirmed, as well as bacteriophages that different studies have shown the efficacy of phage therapy against infections. In recent years, the scientific community has been attracted by the socalled photothermal therapy to combat pathogens (nanomaterials and metals), plant-derived antimicrobials and other advances such as bisphocins and hydrogels that can be used in the treatment of infections caused by antibiotic resistant bacteria. It is concluded that there are state-of-the-art antimicrobials that could be part, now or in the future, of a new therapeutic arsenal. [ABSTRACT FROM AUTHOR]

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New antibiotic agents were prepared using Povarov and Ugi multicomponent reactions upon the known drugs sulfadoxine and dapsone. The prepared derivatives, with increased lipophilicity, showed improved efficiency against Mycolata bacteria. Microbiological guidance for medicinal chemistry is a powerful tool to design new and effective antimicrobials. In this case, the readily synthesized compounds open new possibilities in the search for antimicrobials active on mycolic acid-containing bacteria. [ABSTRACT FROM AUTHOR]

The hexanic extracts of Hypericum austrobrasiliense, H. caprifoliatum, H. denudatum, H. pedersenii and H. polyanthemum, and three isolated dimeric acylphloroglucinols (uliginosin B, japonicine A and hyperbrasilol B) were assayed for their antimicrobial activity against some Gram-positive and Gram-negative bacteria (including resistant strains). These extracts were assayed using the disc diffusion test, and the results indicated that the tested species did non exhibit activity on the Gram-negative strains. Subsequently, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were measured using the broth dilution technique adopted to macrodillution. The most susceptible strains were the MRSA and the S. aureus MLSb. Regarding these pathogens, the better MIC values were obtained with the extracts from H. austrobrasiliense, H. caprifoliatum and H. pedersenii. The acylphloroglucinols uliginosin B and hyperbrasilol B presented the lowest MIC values against Enterococcus faecalis, Staphylococcus aureus, MRSA and S. aureus MLSb resistance. [ABSTRACT FROM AUTHOR]

Pharmaceutical compounds have been introduced into the aquatic ecosystems in multiple ways and sources, which negatively affects the health of the environment and humans. The river near the hospital sewage disposal is host environment for drug-resistant bacteria (DRB). In this context, the aim of the research was to detect the presence of pharmaceuticals in hospital wastewater, after treatment, at river point followed by isolation of bacteria and test for resistant pharmaceutical compound. Fifteen species of bacteria isolated by angiogenic methods were identified and tested using the well diffusion test to determine the resistance of selected bacteria to ibuprofen by survival assessment. This study showed that the ibuprofen detected by GC-mass was available in all selected points at a concentration of 3 to 120 mg/L. Lecuco. mesen.cremris and Koc.rosea have a high ability to break down the ibuprofen compound. Thus, the bacteria isolated from hospital wastewater can biologically degrade ibuprofen. [ABSTRACT FROM AUTHOR]

Chromium is one of the most widely used metals in industry. Hexavalent form [Cr(VI)], which is found in industrial discharges, is very toxic and very soluble in water. From soil taken from an abandoned lead and iron mine, a bacterial strain capable of reducing Cr(VI) was isolated and identified as Brachybacterium paraconglomeratum ER41. Objective of this work was to evaluate the power of this bacterium to reduce Cr(VI). Results obtained showed that this bacterium is capable of eliminating 100 mg/L of Cr(VI) after 48 h (pH 8 and temperature 30 °C). For modeling biosorption kinetics, pseudo-first-order and intraparticle diffusion models gave a better fit. Furthermore, the adsorption mechanism conformed well to Langmuir’s isothermal model indicating monolayer type sorption. Biomass analysis of this bacterium before and after contact with chromium by scanning electron microscopy–energy-dispersive X-ray and by Fourier transform infrared spectroscopy showed that the surface ligands of bacterial wall are probably responsible for biosorption and bioreduction process. These results suggest a potential application of B. paraconglomeratum ER41 in bioremediation of polluted discharges. [ABSTRACT FROM AUTHOR]

The quality of many freshwater environments is impacted by human activities, so that many rivers may represent a vehicle for the transmission of health-related microorganisms. This work aimed to isolate and identify genetically free-living amoeba (FLA) of the genus Acanthamoeba from a recreational river in Salta, Argentina, and isolate, if possible, an endocytobiont. Sampling took place at four points (P1–P4) throughout the river in the winter and the summer seasons. Free-living amoebae and Acanthamoeba were recovered from 20-L water concentrated through an ultrafiltration system. Isolation was performed in agar plates, confirmation of Acanthamoeba genus by PCR, and fellow identification and classification based on their sequence analyses. High concentrations of indicator bacteria were found especially in P2, which is intensively used for recreation. Out of a total of 29 FLA isolations, 9 were identified as Acanthamoeba genotype T4 subtype A, the most frequent genotype found in nature and associated with causing human disease. From an axenic culture of Acanthamoeba spp. (KY751412), a bacterial endocytobiont was isolated, and identified as Stenotrophomonas maltophilia. The endocytobiont showed resistance and intermediate resistance to a wide range of widely used antibiotics. Results were in concordance with the cosmopolitan behavior of Acanthamoeba, and showed the importance of studying this group of amoebae and related microorganisms in recreational environments. [ABSTRACT FROM AUTHOR]

The expansion of industry, climate change, deforestation, and pollution of oceans, and exponential increase in the multidrug-resistant bacteria, humans are more to danger than ever before. In recent years, humans have been affected more than ever by bacterial and fungal infections and even mosquito-related diseases such as lymphatic filariasis, malaria, and cellulitis. For example, Candida albicans and Aspergillus fumigatus can cause invasive fungal infections in any organ of humans, and their resistance to antibiotics is increasing. For a long period of time, plant components have been used for curing the various ailments. Herbs were the basis of medicine in the past and also are extensively used in some countries such as China and India. The study of antimicrobial effects of plants is increasing continuously, which is due to the presence of diverse levels of their bioactive compounds. Humans are so interested in using natural antibacterial compounds like plant extracts and spices because they have their own characteristic flavor. Plants are useful for supporting human health and some parts of the plant (flowers, leaves, stems, and roots) have medicinal activities such as analgesics, antispasmodics, antimicrobials. With recent advances, in addition to plants, polymers and nanoparticles have come to the help of medical cures. Polymers and nanoparticles due to their unique properties, can be used in a variety of fields such as prosthesis, antibacterial and antifungal surfaces, drug carrier, gene delivery, cancer diagnosis, colorimetric detection of cancer cells, and cancer imaging. In this study, researches on plants, polymers, and nanoparticles antibacterial are reviewed.

Interactions between species are essential in ecosystems, but sometimes competition dominates over mutualism. The transition between mutualism-competition can have several implications and consequences, and it has hardly been studied in experimental settings. This work studies the mutualism between cross-feeding bacteria in strains that supply an essential amino acid for their mutualistic partner when both strains are exposed to antimicrobials. When the strains are free of antimicrobials, we found that, depending on the amount of amino acids freely available in the environment, the strains can exhibit extinction, mutualism, or competition. The availability of resources modulates the behavior of both species. When the strains are exposed to antimicrobials, the population dynamics depend on the proportion of bacteria resistant to the antimicrobial, finding that the extinction of both strains is eminent for low levels of the resource. In contrast, competition between both strains continues for high levels of the resource. An optimal control problem was then formulated to reduce the proportion of resistant bacteria, which showed that under cooperation, both strains (sensitive and resistant) are immediately controlled, while under competition, only the density of one of the strains is decreased. In contrast, its mutualist partner with control is increased. Finally, using our experimental data, we did parameters estimation in order to fit our mathematical model to the experimental data.

Resistensi antibiotik merupakan isu yang genting dijadikan topik penelitian beberapa tahun belakangan ini, dimana salah satu penyebab terjadinya resistensi antibiotik adalah penggunaan antibiotik secara terus menerus dengan dosis yang tidak tepat. Salah satu alternatif yang memiliki peluang untuk melawan bakteri resisten adalah dengan menggunakan bakteriosin. Bakteriosin merupakan senyawa protein yang secara biologis aktif, memiliki berat molekul kecil dan memiliki sifat antibakteri yang umumnya bersifat bakterisidal. Penelitian ini dilakukan dengan metode kajian pustaka dari literatur yang sesuai dengan topik penelitian. Hasil penelitian menunjukkan bahwa bakteriosin banyak dihasilkan oleh bakteri asam laktat, salah satunya dari genus Lactobacillus, seperti L. paracasei, L. plantarum, L. coryniformis, dan L. crustorum, yang memiliki karakteristik menguntungkan seperti stabil terhadap pH dan suhu dan mampu bekerja pada spektrum luas dengan menghambat pertumbuhan bakteri Gram-positif dan Gram-negatif yang resistan terhadap antibiotik, dan pada umumnya memiliki mekanisme antibakteri melalui pembentukan pori-pori yang akan mempengaruhi permeabilitas membran sel dan pada akhirnya menyebabkan kematian sel

Frequent and unlimited use of antibiotics caused the development of antibiotic resistance by microorganisms. Therefore, there is an argent need to discover novel antibacterial agents or a combination of agents as a safe treatment strategy for various infections. In the present study the synergistic effects of cLFchimera, an antimicrobial peptides, and Vancomycin antibiotic were evaluated using checkerboard method against Methicillin Resistant Staphylococcus aureus (MRSA) bacteria strain. cLFchimera had antimicrobial activity against MRSA and Methicillin Sensitive Staphylococcus aureus (MSSA) (MIC: 256 and 512 µg/mL, respectively). A synergistic effect was observed in the combination of cLFchimera with Vancomycin (FIC: 0.375). The results showed that at FIC concentrations, release cytoplasmic materials from bacterial cells and the number of surviving cells were significantly (P≤0.05) higher and lower, respectively, than when peptides or antibiotic were used alone. SEM electron microscopic analysis at FIC concentration showed severe membrane damage of bacterial cells. In conclusion, the use of cLFchimera and Vancomycin at FIC concentration reduces the consumption of both substances.

Resistant infectious diseases caused by gram-negative bacteria are among the most serious worldwide health problems. Antimicrobial peptides (AMPs) have been explored as promising antibacterial, antibiofilm, and anti-infective candidates to address these health challenges. Here we report the potent antibacterial effect of the peptide PaDBS1R6 on clinical bacterial isolates and identify an immunomodulatory peptide fragment incorporated within it. PaDBS1R6 was evaluated against Acinetobacter baumannii and Escherichia coli clinical isolates and had minimal inhibitory concentration (MIC) values from 8 to 32 μmol L−1. It had a rapid bactericidal effect, with eradication showing within 3 min of incubation, depending on the bacterial strain tested. In addition, PaDBS1R6 inhibited biofilm formation for A. baumannii and E. coli and was non-toxic toward healthy mammalian cells. These findings are explained by the preference of PaDBS1R6 for anionic membranes over neutral membranes, as assessed by surface plasmon resonance assays and molecular dynamics simulations. Considering its potent antibacterial activity, PaDBS1R6 was used as a template for sliding-window fr agmentation studies (window size = 10 residues). Among the sliding-window fragments, PaDBS1R6F8, PaDBS1R6F9, and PaDBS1R6F10 were ineffective against any of the bacterial strains tested. Additional biological assays were conducted, including nitric oxide (NO) modulation and wound scratch assays, and the R6F8 peptide fragment was found to be active in modulating NO levels, as well as having strong wound healing properties. This study proposes a new concept whereby peptides with different biological properties can be derived by the screening of fragments from within potent AMPs. [Display omitted] • PaDBS1R6 has a preference for Gram-negative bacterial membranes. • PaDBS1R6 showed a potent and fast bactericidal activity. • PaDBS1R6 undergoes a coil-to-α-helix transition in membrane-like environments. • PaDBS1R6 crosses outer membranes and ends up attached to inner membranes. • PaDBS1R6 has an immunomodulatory peptide encrypted within its sequence. [ABSTRACT FROM AUTHOR]

We report here on the structure-activity relationships of hybrids combining 3-descladinosyl clarithromycin with quinolones linked by extended diamine connectors. Several hybrids, exemplified by 23Bc , 23Be , 23Bf , 26Be , and 30Bc , not only restored potency against inducibly resistant pathogens but also exhibited significantly enhanced activities against constitutively resistant strains of Staphylococcus pneumoniae and Staphylococcus pyogenes , which express high-level resistance independent of clarithromycin or erythromycin induction. Additionally, the novel hybrids showed susceptibility against Gram-negative Haemophilus influenzae. Notably, hybrid 23Be demonstrated dual modes of action by inhibiting both protein synthesis and DNA replication in vitro and in vivo. Given these promising characteristics, 23Be emerges as a potential candidate for the treatment of community-acquired bacterial pneumonia. [Display omitted] • The SARs of non-ketolides with extended sidechains at the 3-OH were illuminated. • The sidechain at 9-oxime resulted in synergistic effects that increase efficacy. • Compound 23Be demonstrated inhibitory effects on both DNA gyrase and ribosomes. • Compound 23Be exhibited improved potencies against constitutively resistant bacteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • The SARs of alkylides with extended sidechains at the 3-OH were elucidated. • The quinolone moiety exerts extra effects on enhancing antibacterial activity. • Compound 31f demonstrated inhibitory effects on both ribosomes and topoisomerases. • Compound 31f exhibited improved potency against constitutively resistant bacteria. Ketolides (3-keto) such as TE-802 and acylides (3- O -acyl) like TEA0929 are ineffective against constitutively resistant pathogens harboring erythromycin ribosomal methylation (erm) genes. Following our previous work on alkylides (3- O -alkyl), we explored the structure–activity relationships of hybrids combining (R/S) 3-descladinosyl erythromycin with 6/7-quinolone motifs, featuring extended ether-linked spacers, with a focus on their efficacy against pathogens bearing constitutive erm gene resistance. Optimized compounds 17a and 31f not only reinstated efficacy against inducibly resistant pathogens but also demonstrated significantly augmented activities against constitutively resistant strains of Streptococcus pneumoniae and Streptococcus pyogenes , which are typically refractory to existing C-3 modified macrolides. Notably, hybrid 31f (coded ZN-51) represented a pioneering class of agents distinguished by its dual modes of action, with ribosomes as the primary target and topoisomerases as the secondary target. As a novel chemotype of macrolide-quinolone hybrids, alkylide 31f is a valuable addition to our armamentarium against macrolide-resistant bacteria. [ABSTRACT FROM AUTHOR]

Conjugated benzimidazole derivatives have been proven in numerous studies to have a variety of biological activities, including antibacterial characteristics. Using methlene linkers, we created and synthesized N-substituted alkylbenzimidazole derivatives in this study that were attached to tetrazole (an1-an5). The prepared molecules were confirmed using FTIR and NMR spectroscopies. The outcomes demonstrated that the synthesized benzimidazole compounds boosted the activity effects on Escherichia coli and Staphylococcus aureus strains. These derivatives included a 5-membered ring with nitrogen and an alkyl chain. (an2) compound shown good action against Staphylococcus Aureus strains whereas (an4 and na5) exhibited good activity against Escherichia Coli strains among the produced compounds. [ABSTRACT FROM AUTHOR]

N-substituted alkylbenzimidazole derivatives connected to 1,2,3-triazole through methlene linkers (tb1, tb2, tb3, tb4 and tb5) were prepared and designed with the goal of estimating their anti-organism activity such as anti-bacterial activity. FTIR and NMR spectroscopies were used to analyzed the prepared compounds. The biological potential of these substances was examined for antibacterial activity against tow type of microorganisms, the first [gram-negative (Escherichia Coli)] and the second [gram-positive (Staphylococcus Aureus)]. Compared with Gramnegative bacteria, all compounds showed a strong effect against Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

This is a retrospective study of our experience with Gentamicin intravesical instillation as therapy and prophylaxis in patients with lower urinary tract infections (UTIs) undergoing clean intermittent catheterization because of a neurogenic bladder. It is an alternative therapy when all other systemic treatments have failed as it is still an off-label prescription. [ABSTRACT FROM AUTHOR]

The need for discovering new compounds that can act selectively on pathogens is becoming increasingly evident, given the number of deaths worldwide due to bacterial infections or tumor cells. New multifunctional biotechnological tools are being sought, including compounds present in spider venoms, which have high biotechnological potential. The present work aims to perform the rational design and functional evaluation of synthetic peptides derived from Lachesana tarabaevi spider toxin, known as latarcin- 3a. The antimicrobial activity was tested against Gram-positive and -negative bacteria, with minimum inhibitory concentrations (MIC) between 4 and 128 µg.ml-1. Anti-biofilm tests were then performed to obtain MICs, where the peptides demonstrated activity from 4 to 128 µg.ml-1. In vitro cell cytotoxicity assays were carried out from tumor cell lines, lineages C1498, Kasumi-1, K-562, Jurkat, MOLT4, and Raji. Erythrocyte integrity was evaluated in the presence of synthetic peptides analog, which did not promote hemolysis at 128 µg.ml-1. The peptide that showed the best antibacterial activity was Lt-MAP3 and the best antitumor was Lt-MAP2. In conclusion, rational design of multifunctional antimicrobial peptides may be promising alternative tools in the treatment of emerging diseases such as bacterial infections and tumor cells. [ABSTRACT FROM AUTHOR]

Antibiotics have long been used for the prevention and treatment of common diseases and for prophylactic purposes in dairy animals. However, in recent decades it has become a matter of concern due to the widespread belief that there has been an abuse or misuse of these drugs in animals and that this misuse has led to the presence of residues in derived foods, such as milk and dairy products. Therefore, this review aims to compile the scientific literature published to date on the presence of antibiotic residues in these products worldwide. The focus is on the reasons that lead to their presence in food, on the potential problems caused by residues in the characteristics of dairy products and in their manufacturing process, on the development and spread of antibiotic-resistant bacteria, and on the effects that both residues and resistant bacteria can cause on human and environmental health. [ABSTRACT FROM AUTHOR]