Search

Nowadays, there has been an increasing research interest into N-halamine compounds due to their wide antimicrobial properties and no drug resistance. Most of the research mainly focuses on small molecular N-halamines, while few studies are on macromolecule N-halamines. In this work, antibacterial N-halamine polymer materials based on proteins (GS-Cl) were synthesized with an antibacterial component of oxidative chlorine, a support component of a gelatin sponge. After carrying out systematic characterization, the GS-Cls exhibited well-defined porous morphology and had a high efficiency in the killing of Gram-positive bacteria (E. coli) and Gram-negative bacteria (S. aureus). The loading of oxidative chlorine (Cl+%) could be controlled by changing the NaClO concentrations and chlorination times. The biocompatibility was confirmed as well. In vivo experiments suggested that the GS-Cl sample could effectively promote the healing of skin wounds in mice E. coli and S. aureus infection models. These studies show that proteins can be chlorinated and endowed with antimicrobial properties, which has great application potential in the treatment of bacteria-infected wounds. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is an opportunistic Gram-negative pathogen with exquisite survival capabilities under various environmental conditions and displays widespread resistance to common antibiotics. A. baumannii is a leading cause of nosocomial infections that result in high morbidity and mortality rates. Accordingly, when multidrug resistance rates surpass threshold levels, the percentage of A. baumannii clinical isolates surges. Research into A. baumannii has increased in the past decade, and multiple mechanisms of pathogenesis have been identified, including mechanisms underlying biofilm development, quorum sensing, exotoxin production, secretion system utilization, and more. To date, the two gold-standard strains used to investigate different aspects of A. baumannii pathogenesis include ATCC 17978 and ATCC 19606. Here, we report a comparative characterization study of three additional A. baumannii clinical isolates obtained from different infection types and derived from different anatomical regions of infected patients. The comparison of three clinical isolates in addition to the ATCC strains revealed that the hypervirulent bacteremia clinical isolate, known as HUMC1, employs a completely different mechanism of pathogenesis when compared to all its counterparts. In stark contrast to the other genetic variants, the hypervirulent HUMC1 isolate does not form biofilms, is antibiotic-susceptible, and has the capacity to reach higher levels of quorum compared to the other clinically relevant strains. Our data also reveal that HUMC1 does not shed endotoxin into the extracellular milieu, rather secretes the evolutionarily conserved, host-mimicking, Zonula occludens toxin (Zot). Taken together, our hypothesis that HUMC1 cells have the ability to reach higher levels of quorum and lack biofilm production and endotoxin shedding, accompanied by the substantial elaboration of Zot, suggests a novel mechanism of pathogenesis that appears to afford the hypervirulent pathogen with stealth-like capabilities when disseminating through the circulatory system in a state of bacteremia. [ABSTRACT FROM AUTHOR]

Quorum sensing (QS) is a mechanism by which bacteria detect and respond to cell density, regulating collective behaviors. Burkholderia plantarii, the causal agent of rice seedling blight, employs the LuxIR-type QS system, common among Gram-negative bacteria, where LuxI-type synthase produces QS signals recognized by LuxR-type regulators to control gene expression. This study aimed to elucidate the QS mechanism in B. plantarii KACC18965. Through whole-genome analysis and autoinducer assays, the plaI gene, responsible for QS signal production, was identified. Motility assays confirmed that C8-homoserine lactone (C8-HSL) serves as the QS signal. Physiological experiments revealed that the QS-defective mutant exhibited reduced virulence, impaired swarming motility, and delayed biofilm formation compared to the wild type. Additionally, the QS mutant demonstrated weakened antibacterial activity against Escherichia coli and decreased phosphate solubilization. These findings indicate that QS in B. plantarii significantly influences various pathogenicity and survival traits, including motility, biofilm formation, antibacterial activity, and nutrient acquisition, highlighting the critical role of QS in pathogen virulence and adaptability. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a ubiquitous environmental Gram-negative bacterium and also an opportunistic pathogen for both humans and animals, causing acute or chronic infections. It has been frequently detected in healthy and diseased reptiles, more commonly in captive ones. Since most studies are primarily on clinical isolates, the pathogenic potential of strains originating from wild animals is poorly explored. We isolated the strain P. aeruginosa PM1012 from the cloacal microbiota of a common wall lizard (Podarcis muralis Laurenti, 1768) from a free-living population. The effect of temperature, pH and salinity on its growth was evaluated. Antibiotic resistance, the expression of several virulence factors as some extracellular enzymes, pyocyanin production and biofilm formation were also assessed. Apart from intrinsic resistance, the newly isolated strain P. aeruginosa PM1012 presented an antibiotic susceptibility profile with a low resistance rate limited to meropenem and intermediate to ceftazidime and aztreonam. Protease, lipase and gelatinase secretion was detected. Strong pyocyanin production was observed in the optimal range of growth conditions. An excellent biofilm-forming capacity was manifested. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic bacteria frequently linked to burn wound infections. These bacteria can grow as biofilms, which increases their level of drug resistance to current antibiotics. The purpose of the present study is to analyze the effect of biofilm formation, phage and phage cocktail action on single species and dual species biofilms I, e the coexistence of Gram positive (S. aureus) and Gram negative (P. aeruginosa). To this scenario, we employed multi-drug resistant bacteria (P. aeruginosa and S. aureus at 109 CFU/µL) biofilm as single and in combination of both Gram-positive and Gram-negative bacterial biofilms of 24 h grown with respective phage (109 PFU/µL) and phage cocktail (109 PFU/µL) at 4 h of incubation under static conditions. The bacteriolytic activity of phages vB_SAnS_SADP1 and vB_PAnP_PADP4 on 24-h-old biofilms of P. aeruginosa (0.761 ± 0.031) and S. aureus (0.856 ± 0.055), both alone and in combination (0.67 ± 0.02), was the focus of this investigation. The structural organization of biofilms in single- or dual-species combinations under in vitro conditions was validated by scanning and confocal laser scanning microscopy investigations. After 24 h of incubation, single-species biofilms are denser and more resilient whereas dual species biofilms are more loosely associated. Loose association of dual-species biofilm under scanning electron microscopic images at the same conditions, indicated the interspecies -competition of the Gram-positive and Gram-negative bacteria and dual-species biofilms (0.67 ± 0.02) have weak associations and are readily impacted by phage and a phage cocktail (0.16 ± 0.02). Dual-species biofilms were more readily impacted in in vitro settings. [ABSTRACT FROM AUTHOR]

Cannabis sativa L. has garnered attention as a potential source for new antimicrobial agents, particularly due to the increased prevalence of microbial resistance to conventional antimicrobials and the emergence of multidrug-resistant pathogens. This review, conducted according to the PRISMA 2020 statement, systematically analyzed the antimicrobial properties of C. sativa extracts and cannabinoids against various bacteria, fungi, viruses, and parasites. Data were collected from the scientific literature (102 papers) and clinical trials (5 studies) from 2014 to June 2024. Findings revealed that cannabinoids, especially CBD, demonstrate significant antimicrobial activity against Gram-positive bacteria like MRSA, Gram-negative bacteria such as Pseudomonas aeruginosa, various Candida species, SARS-CoV-2, and HIV. Additionally, CBD showed efficacy against parasitic infections like Echinococcus granulosus and Leishmania species. These results suggest that cannabinoids may represent a new class of antimicrobial agents with unique and diverse mechanisms of action, potentially effective in broad-spectrum therapies. This study highlights the urgent need for further research and standardized clinical trials to validate these findings and to develop cannabinoid-based treatments. The antimicrobial properties of C. sativa align with WHO priorities and support global health initiatives, offering promising avenues for addressing antimicrobial resistance and improving public health outcomes. [ABSTRACT FROM AUTHOR]

Rice–Xanthomonas oryzae pv. oryzicola (Xoc) is one of the commonly used rice models of host–pathogen interactions. Xoc causes bacterial leaf streak (BLS) and has quarantine status. As a Gram-negative pathogen, Xoc usually employs type III secretion effectors (T3SEs), including transcription activator-like effectors (TALEs) and non-TALEs, to interfere with the innate immunity of rice. However, few major resistance genes corresponding to Xoc are found in rice cultivations; only Rxo1-AvrRxo1 and Xo1-TALEs interactions have been discovered in rice–Xoc. In this review, we focus on the role of the T3S system (T3SS) in Xoc virulence and consider the reported non-TALEs, including AvrRxo1, AvrBs2, XopN, XopC2, XopAP, and XopAK, as well as TALEs including Tal2g/Tal5d, Tal2h, Tal2a, Tal7, Tal10a, TalI, Tal2b, and Tal2c. Interestingly, AvrRxo1, XopC2, and XopAP disturb stomatal opening to promote infection through targeting diverse signaling pathways in rice. Otherwise, Tal2b and Tal2c, respectively, activate two rice salicylic acid (SA) hydroxylation genes to redundantly suppress the SA-mediated basal defense, and TalI, which has unknown targets, suppresses the SA signaling pathway in rice. In addition, other Xoc virulence factors are discussed. In conclusion, several T3SEs from Xoc interfere with similar defense pathways in rice to achieve invasion, providing an outlook for the control of this disease through manipulating the conserved pathways. [ABSTRACT FROM AUTHOR]

Abstract: Cell surface signaling (CSS) is a means of rapidly adjusting transcription in response to extracellular stimuli in Gram-negative bacteria. The pseudobactin BN7/8 uptake (Pup) system not only imports iron but also upregulates its own transcription through CSS in Pseudomonas capeferrum. In the absence of ferric pseudobactin BN7/8, the signaling components are maintained in a resting state via the formation of a periplasmic complex between the N-terminal signaling domain (NTSD) of the outer membrane iron-transporter, PupB, and the C-terminal CSS domain (CCSSD) of the sigma regulator, PupR. The previously determined 1.6 Å crystal structure of this periplasmic complex has allowed us to probe the structural and thermodynamic consequences of mutating key interfacial residues. In this report, we describe the solution structure of the PupB NTSD and use Nuclear Magnetic Resonance spectroscopy, Isothermal Titration Calorimetry, and Circular Dichroism spectroscopy together with thermal denaturation to investigate whether three PupB point mutations, Q69K, H72D, and L74A, influence the interaction merely due to the chemical nature of the amino acid substitution or also cause changes in overall protein structure. Our results demonstrate that binding to the PupR CCSSD does not alter the structure of PupB NTSD and that the individual mutations have only minor effects on structure. The mutations generally lower thermodynamic stability of the NTSD and weaken binding to the CCSSD. These findings validate the X-ray crystal structure interface, emphasizing the importance of amino acid chemical nature at the interface. [ABSTRACT FROM AUTHOR]

The ability of bacteria to recycle exogenous amino acid-based peptides and amino sugars for peptidoglycan biosynthesis was extensively investigated using optical imaging. In particular, fluorescent AeK–NBD was effectively utilized to study the peptidoglycan recycling pathway in Gram-negative bacteria. Based on these promising results, we were inspired to develop the radioactive AeK conjugate [68Ga]Ga-DOTA-AeK for the in vivo localization of bacterial infection using PET/CT. An easy-to-implement radiolabeling procedure for DOTA-AeK with [68Ga]GaCI3 followed by solid-phase purification was successfully established to obtain [68Ga]Ga-DOTA-AeK with a radiochemical purity of ≥95%. [68Ga]Ga-DOTA-AeK showed good stability over time with less protein binding under physiological conditions. The bacterial incorporation of [68Ga]Ga-DOTA-AeK and its fluorescent Aek-NBD analog were investigated in live and heat-killed Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Unfortunately, no conclusive in vitro intracellular uptake of [68Ga]Ga-DOTA-AeK was observed for E. coli or S. aureus live and heat-killed bacterial strains (p > 0.05). In contrast, AeK-NBD showed significantly higher intracellular incorporation in live bacteria compared to the heat-killed control (p < 0.05). Preliminary biodistribution studies of [68Ga]Ga-DOTA-AeK in a dual-model of chronic infection and inflammation revealed limited localization at the infection site with non-specific accumulation in response to inflammatory markers. Finally, our study demonstrates proof that the intracellular incorporation of AeK is necessary for successful bacteria-specific imaging using PET/CT. Therefore, Ga-68 was not a suitable radioisotope for tracing the bacterial uptake of AeK tripeptide, as it required chelation with a bulky metal chelator such as DOTA, which may have limited its active membrane transportation. An alternative for optimization is to explore diverse chemical structures of AeK that would allow for radiolabeling with 18F or 11C. [ABSTRACT FROM AUTHOR]

The reaction of thiophene-2-carbohydrazide 1 or 5-bromothiophene-2-carbohydrazide 2 with various haloaryl isothiocyanates and subsequent cyclization by heating in aqueous sodium hydroxide yielded the corresponding 4-haloaryl-5-(thiophen-2-yl or 5-bromothiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 5a-e. The triazole derivatives 5a and 5b were reacted with different secondary amines and formaldehyde solution to yield the corresponding 2-aminomethyl-4-haloaryl-2,4-dihydro-3H-1,2,4-triazole-3-thiones 6a–e, 7a–e, 8, 9, 10a and 10b in good yields. The in vitro antimicrobial activity of compounds 5a–e, 6a–e, 7a–d, 8, 9, 10a and 10b was evaluated against a panel of standard pathogenic bacterial and fungal strains. Compounds 5a, 5b, 5e, 5f, 6a–e, 7a–d, 8, 9, 10a and 10b showed marked activity, particularly against the tested Gram-positive bacteria and the Gram-negative bacteria Escherichia coli, and all the tested compounds were almost inactive against all the tested fungal strains. In addition, compounds 5e, 6a–e, 7a–d and 10a exhibited potent anti-proliferative activity, particularly against HepG-2 and MCF-7 cancer cell lines (IC50 < 25 μM). A detailed structural insight study based on the single crystals of compounds 5a, 5b, 6a, 6d and 10a is also reported. Molecular docking studies of the highly active antibacterial compounds 5e, 6b, 6d, 7a and 7d showed a high affinity for DNA gyrase. Meanwhile, the potent anti-proliferative activity of compounds 6d, 6e and 7d may be attributed to their high affinity for cyclin-dependent kinase 2 (CDK2). [ABSTRACT FROM AUTHOR]

Some antibiotics that are frequently employed are β-lactams. In light of the hydrolytic process of β-lactamase, found in Gram-negative bacteria, inhibitors of β-lactamase (BLIs) have been produced. Examples of first-generation β-lactamase inhibitors include sulbactam, clavulanic acid, and tazobactam. Many kinds of bacteria immune to inhibitors have appeared, and none cover all the β-lactamase classes. Various methods have been utilized to develop second-generation β-lactamase inhibitors possessing new structures and facilitate the formation of diazabicyclooctane (DBO), cyclic boronate, metallo-, and dual-nature β-lactamase inhibitors. This review describes numerous promising second-generation β-lactamase inhibitors, including vaborbactam, avibactam, and cyclic boronate serine-β-lactamase inhibitors. Furthermore, it covers developments and methods for synthesizing MβL (metallo-β-lactamase inhibitors), which are clinically effective, as well as the various dual-nature-based inhibitors of β-lactamases that have been developed. Several combinations are still only used in preclinical or clinical research, although only a few are currently used in clinics. This review comprises materials on the research progress of BLIs over the last five years. It highlights the ongoing need to produce new and unique BLIs to counter the appearance of multidrug-resistant bacteria. At present, second-generation BLIs represent an efficient and successful strategy. [ABSTRACT FROM AUTHOR]

The arsRBC operon encodes a three-protein arsenic resistance system. ArsR regulates the transcription of the operon, while ArsB and ArsC are involved in exporting trivalent arsenic and reducing pentavalent arsenic, respectively. Previous research into Agrobacterium tumefaciens 5A has demonstrated that ArsR has regulatory control over a wide range of metal-related proteins and metabolic pathways. We hypothesized that ArsR has broad regulatory control in other Gram-negative bacteria and set out to test this. Here, we use differential proteomics to investigate changes caused by the presence of the arsR gene in human microbiome-relevant Escherichia coli during arsenite (AsIII) exposure. We show that ArsR has broad-ranging impacts such as the expression of TCA cycle enzymes during AsIII stress. Additionally, we found that the Isc [Fe-S] cluster and molybdenum cofactor assembly proteins are upregulated regardless of the presence of ArsR under these same conditions. An important finding from this differential proteomics analysis was the identification of response mechanisms that were strain-, ArsR-, and arsenic-specific, providing new clarity to this complex regulon. Given the widespread occurrence of the arsRBC operon, these findings should have broad applicability across microbial genera, including sensitive environments such as the human gastrointestinal tract. [ABSTRACT FROM AUTHOR]

We developed a synthesis strategy involving a diazo transfer reaction and subsequent click reaction to conjugate a murine cathelicidin-related antimicrobial peptide (CRAMP18–35) to chitosan and hydroxypropyl chitosan (HPC), confirmed the structure, and investigated the antimicrobial activity. Chitosan azide and HPC-azide were prepared with a low degree of azidation by reacting the parent chitosan and HPC with imidazole sulfonyl azide hydrochloride. CRAMP18–35 carrying an N-terminal pentynoyl group was successfully grafted onto chitosan and HPC via copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. The chitosan–peptide conjugates were characterized by IR spectroscopy and proton NMR to confirm the conversion of the azide to 1,2,3-triazole and to determine the degree of substitution (DS). The DS of the chitosan and HPC CRAMP18–35 conjugates was 0.20 and 0.13, respectively. The antibacterial activity of chitosan–peptide conjugates was evaluated for activity against two species of Gram-positive bacteria, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and two species of Gram-negative bacteria, Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). The antimicrobial peptide conjugates were selectively active against the Gram-negative bacteria and lacking activity against Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

Outer membrane vesicles (OMVs) are nanostructures derived from the outer membrane of Gram-negative bacteria. We previously demonstrated that vaccination with endotoxin-free OMVs isolated from an Acinetobacter baumannii strain lacking lipooligosaccharide (LOS) biosynthesis, due to a mutation in lpxD, provides full protection in a murine sepsis model. The present study characterizes the protein content of highly-purified OMVs isolated from LOS-replete and LOS-deficient strains. Four purification methods were evaluated to obtain highly purified OMV preparations: ultracentrifugation, size exclusion chromatography (SEC), ultracentrifugation followed by SEC, and Optiprep™. OMVs from each method were characterized using nanoparticle tracking analysis and electron microscopy. OMVs from LOS-deficient and LOS-replete strains purified using the Optiprep™ method were subjected to LC-MS/MS analysis to determine protein content. Significant differences in protein composition between OMVs from LOS-deficient and LOS-replete strains were found. Computational analyses using Bepipred 3.0 and SEMA 2.0 indicated that the lack of LOS led to the overexpression of immunogenic proteins found in LOS-containing OMVs and the presence of immune-stimulating proteins absent in LOS-replete OMVs. These findings have important implications for developing OMV-based vaccines against A. baumannii, using both LOS-containing and LOS-free OMVs preparations. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate natural products for their potential against pathogenic microorganisms. Sabinene hydrate (SH), a monoterpenoid, is synthesised by numerous different plants as a secondary metabolite. At present, there is a lack of definite investigations regarding the antimicrobial activity of SH itself and its different isomers. The antimicrobial effects of commercially available SH (composed mainly of trans-isomer) were evaluated within a range of concentrations in three types of contact tests: solid and vapor diffusion and the macro-broth dilution method. Moreover, the effects of SH on the rate of linear growth and spore germination were also examined. Ethanolic SH solutions were tested against an array of microorganisms, including blue-stain fungi (Ceratocystis polonica, Ophiostoma bicolor, O. penicillatum), frequently originating from bark beetle galleries; three fungal strains (Musicillium theobromae, Plectosphaerella cucumerina, and Trichoderma sp.) isolated from a sapwood underneath bark beetle galleries (Ips typographus) on spruce (Picea abies) stems; Verticillium fungicola, isolated from diseased I. typographus larvae; two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa); five yeasts (Candida albicans, C. krusei, C. parapsilosis, Saccharomyces cerevisiae, and Rhodotorula muscilaginosa), and two saprophytic fungi (Aspergillus niger and Penicillium notatum). In solid agar disc diffusion tests, Gram-positive bacteria exhibited greater susceptibility to SH than Gram-negative bacteria, followed by yeasts and fungi. The most resistant to SH in both the disc diffusion and broth macro-dilution methods were P. aeruginosa, A. niger, and Trichoderma sp. strains. Blue-stain fungi and fungi isolated from the Picea sapwood were the most resistant among the fungal strains tested. The minimum inhibition concentrations (MICs) generated by SH and determined using a disc volatilization method were dependent on the fungal species and played an important role in the development of microorganism inhibition. The two Gram-positive bacteria, B. subtilis and S. aureus (whose MICs were 0.0312 and 0.0625 mg/mL, respectively), were the organisms most susceptible to SH, followed by the Gram-negative bacterium, E. coli (MIC = 0.125 mg/mL) and two yeasts, C. albicans and C. kruei (MIC was 0.125 mg/mL and 0.25 mg/mL, respectively). C. parapsilosis (MIC = 0.75 mg/mL) was the yeast most resistant to SH. The investigation of antimicrobial properties of plant secondary metabolites is important for the development of a new generation of fungicides. [ABSTRACT FROM AUTHOR]

Background: Urinary tract infection is a worldwide health problem. According to the Clinical Laboratory Improvement Amendments and the European Urinalysis Guideline, urine samples should be tested within 2 h of collection. Thus, using chemical preservatives that guarantee the pre-analytical conditions is a practical tool. However, the effects of temperature and storage time as uropathogenic bacteria stressors are unclear. Methods: Gram-negative and -positive ATTC strains, E. coli, P. mirabilis, E. faecalis, and S. aureus, were used in this study. Strains in liquid media were stored at 4, 25, and 37 °C for 0, 2, 12, 24, and 48 h in tubes with and without preservatives. Then, reactive oxygen species (ROS) levels, viable but non-culturable bacteria (VBNC), and bacteria growth were analyzed. Results: A high ROS level was associated with the presence of VBNC and dead bacteria with low CFU counts, but a low ROS level increased the CFU number, depending on temperature and storage time in tubes without preservatives (boric acid, sodium borate, and formate). The BD Vacutainer™ Urine Culture & Sensitivity Preservative PLUS Plastic Tubes (C&S-PP) prevent this ROS increase, maintaining the CFU number for longer. Conclusions: C&S-PP tubes minimize the stressor effects (temperature and time storage) on uropathogenic bacteria when stored, improving the pre-analytical conditions of cultures realized by the clinical laboratory. [ABSTRACT FROM AUTHOR]

Objective: An increase in antimicrobial resistance (AMR) is observed worldwide, partly due to the overuse and misuse of antibiotics, which are ineffective in certain population subgroups. This negatively impacts both the healthcare system and patients. Our study aimed to investigate the current AMR profiles for the most commonly used antibiotics in treating urinary tract infections (UTIs) caused by gram-negative bacteria (GNB) across different age and gender subpopulations. By doing so, we provide valuable information for doctors managing prophylactic and empiric therapeutic treatments. Materials and Methods: We retrospectively analysed over 650,000 urine cultures collected in the Microbiology Department of a referral university hospital in Southern England from January 2014 to December 2022. A population-based analysis for subgroups was performed to rule out differences in AMR patterns. Our report was recorded at UHS as an internal audit (UHS7670). Results: 146,867 cultures were found positive for GNB growth. Nitrofurantoin showed the best sensitivity patterns for all age subgroups (0.93% for patients aged ≤ 18; 1.22% for patients aged 19–40; 2.17% for patients aged 40–60; and 3.48% for patients aged > 60), regardless of gender (male: 6.37%, female: 2.59%). Ampicillin/amoxicillin and trimethoprim showed a poor AMR profile for all age groups (>55% and >28%, respectively) and genders (>60% and >28%, respectively). All the other tested antibiotics (cefalexin, cefotaxime, ceftazidime, ciprofloxacin, co-amoxiclav, gentamicin) showed an overall good profile for GNB resistance across all subgroups. For all antibiotics except trimethoprim, the risk of developing AMR was significantly higher in the male population. We also found that people aged over 60 had a higher risk of AMR compared to the other age groups for all antibiotics, with the exception of cefotaxime and co-amoxiclav. Conclusions: With an overall rise in resistance patterns for GNB-related UTIs, certain antibiotics—particularly ampicillin/amoxicillin and trimethoprim—now exhibit very poor sensitivity profiles. However, antibiotics such as nitrofurantoin and gentamicin remain excellent options for empirically treating UTIs. It is important to note that AMR can vary across different populations, with higher resistance often found in elderly and male patients. Clinicians must stay informed about current guidelines and research to provide the best treatment options while minimizing the risk of further AMR development. [ABSTRACT FROM AUTHOR]

Urinary tract infections (UTIs) constitute one of the main complications in kidney recipients, increasing both morbidity and mortality. Due to the resurgence of antimicrobial resistance, new prophylactic approaches are being investigated. Nitrofurantoin is an antibiotic from the nitrofuran group that is effective against several Gram-negative and Gram-positive organisms; hence, there has been a resurgence in its prescription for treating MDR pathogens. Objectives: This study aims to assess the effectiveness of nitrofurantoin as an add-on to conventional therapy (amikacin + ceftriaxone or cefotaxime) for the treatment of urinary tract infections in kidney recipients. Methods: In a prospective cohort study, we included patients who received a kidney in a tertiary-care hospital. According to the intensive care specialist, group 1 patients were treated with the conventional prophylactic treatment plus nitrofurantoin as an add-on. Group 2 patients were treated only with the conventional prophylactic treatment. They were followed-up for 3 months, and the incidence of urinary tract infections was reported. Results: The UTI incidence for group 1 at 3 months was 20.6%, and for group 2, it was 20.0%; no statistical difference between treatments was observed (p = 0.9). The most commonly isolated pathogens were E. coli (28.5) and K. pneumonie (28.5%). The factor most associated with developing a UTI was female gender (aHR: 7.0; 95% IC 2.3–20.9, p < 0.001). Conclusions: In our cohort study, nitrofurantoin as an add-on in conventional therapy did not prove to be effective in preventing UTI development; therefore, other treatment options should be considered as a part of prophylactic treatment. [ABSTRACT FROM AUTHOR]

The synthesis of Al-ZnO nanoparticles (NPs) was achieved using a green synthesis approach, utilizing leaf extract from Anisomeles indica (L.) in a straightforward co-precipitation method. The goal of this study was to investigate the production of Al-ZnO nanoparticles through the reduction and capping method utilizing Anisomeles indica (L.) leaf extract. The powder X-ray diffraction, UV spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy with EDAX analysis were used to analyze the nanoparticles. X-ray diffraction analysis confirmed the presence of spherical structures with an average grain size of 40 nm in diameter, while UV–visible spectroscopy revealed a prominent absorption peak at 360 nm. FTIR spectra demonstrated the presence of stretching vibrations associated with O-H, N-H, C=C, C-N, and C=O as well as C-Cl groups indicating their involvement in the reduction and stabilization of nanoparticles. SEM image revealed the presence of spongy, spherical, porous agglomerated nanoparticles, confirming the chemical composition of Al-ZnO nanoparticles through the use of the EDAX technique. Al-ZnO nanoparticles showed increased bactericidal activity against both Gram-positive and Gram-negative bacteria. The antioxidant property of the green synthesized Al-ZnO nanoparticles was confirmed by DPPH radical scavenging with an IC50 value of 23.52 indicating excellent antioxidant capability. Green synthesized Al-ZnO nanoparticles were shown in in vivo studies on HeLa cell lines to be effective for cancer treatment. Additionally, α-amylase inhibition assay and α-glucosidase inhibition assay demonstrated their potent anti-diabetic activities. Moving forward, the current methodology suggests that the presence of phenolic groups, flavonoids, and amines in Al-ZnO nanoparticles synthesized with Anisomeles indica (L.) extract exhibit significant promise for eliciting biological responses, including antioxidant and anti-diabetic effects, in the realms of biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Effective disinfection processes have been investigated to provide pathogen-free drinking water. Due to growing concern about the potential negative effects of cyanobacteria in portable water, their treatment has gained more attention recently. This study aims to compare the inhibition efficiencies of Gram-negative bacteria (Escherichia coli; E. coli), Gram-positive bacteria (Bacillus subtilis; B. subtilis), and cyanobacteria (Microcystis aeruginosa; M. aeruginosa) using UV-C and solar irradiation, and their combination process with H2O2. Over 6 log removal value (LRV) of E. coli and B. subtilis was achieved within 1 min of UV-C irradiation (0.76 ± 0.02 mW/cm2). The solar and solar/H2O2 (50 mg/L) processes effectively reduced (>99%) both bacteria after 20 min. E. coli was more sensitive to hydroxyl radicals (•OH) compared to the B. subtilis due to a different cell wall structure, resulting in a 0.18–0.62 higher LRV than B. subtilis. However, solar-based processes did not effectively inhibit M. aeruginosa (>52.23%). The UV-C/H2O2 (50 mg/L) process showed the highest inhibition rate for M. aeruginosa (77.83%) due to the generation of •OH, leading to oxidative damage to cells. Additionally, chlorophyll-a (Chl-a) was measured to indicate cell lysis of M. aeruginosa. The removal rate of Chl-a extracted by viable M. aeruginosa was higher using the UV-C process (93.03%) rather than the UV-C/H2O2 process (80.95%), because UV-C irradiation could be most effective in damaging Chl-a. [ABSTRACT FROM AUTHOR]

Synthetic and untreated dyes discharged in wastewater effluents are a threat to an ecosystem. This study investigated dye degradation and detoxification efficiency of crude lignin peroxidase separately obtained from the cultures of Escherichia coli (LR0250096.1) and Pseudomonas aeruginosa (CP031449.2). The ability of the crude lignin peroxidase to degrade Malachite Green (MG), Remazol Brilliant Blue R (RBBR), Congo Red (CR), and Azure B (AZ) was evaluated at different operating conditions (enzyme, dye, and hydrogen peroxide concentrations; pH; temperature; and contact time). The ability of the degraded dyes to support the growth of bacteria was also investigated. The observed optimum operating conditions for lignin peroxidase extracts of the Escherichia coli on AZ were 20 mg/mL enzyme concentration, 50 mg/L dye, pH 7.0, temperature 50 °C, and 1.5 mM hydrogen peroxide within 20–50 min of incubation time and on MG were 20 mg/mL, 50 mg/L, 9.0, 30 °C, 0.1 mM, and 20 min, respectively. The enzyme extract from Pseudomonas aeruginosa on AZ demonstrated optimum operation conditions of 20 mg/mL, 50 mg/L, pH 9.0, 40 °C, 1.5 mM, and 50 min, respectively and on MG, they were 20 mg/mL, 50 mg/L, 6.0, 30 °C, 1.0 mM, and 20 min, respectively). The prepared enzyme showed an appreciable degradative effect on CR and RBBR compared with commercial lignin peroxidase. The degraded dyes were able to support the growth of two Gram-positive (Bacillus cereus and Staphylococcus aureus), and two Gram-negative (Proteus mirabilis and Escherichia coli) bacteria, indicating the efficiency and the potential use of the enzyme complexes in the clean-up of industrial dyes' waste. [ABSTRACT FROM AUTHOR]

Background: The escalating resistance of uropathogens in pediatric febrile urinary tract infection (F-UTI) is a global concern. This study examined changing trends in F-UTI epidemiology and resistance patterns among Israeli pediatric inpatients over a decade. Methods: Demographic, clinical, and laboratory data for children between 3 months and 18 years old with febrile UTI from 2010 to 2021 were retrieved from electronic medical records. Results: A total of 761 cases of F-UTI were identified (702 females, mean age 43 months). Escherichia coli was the most common pathogen (85.9%), followed by Pseudomonas aeruginosa (3.5%) and Klebsiella pneumoniae (3.4%). Compared with the non-complicated UTI group, the complicated UTI group had significantly higher rates of Pseudomonas aeruginosa (5.3% vs. 1.0%, p = 0.002) and Klebsiella pneumoniae (4.6% vs. 1.6%, p = 0.03). Antibiotic resistance analysis revealed significant differences between the groups: resistance to cephalexin was higher in the complicated UTI group (19.3%) compared with the non-complicated UTI group (13.4%, p = 0.03). Notably, relatively low resistance rates were observed for ceftriaxone (4.4%) and gentamicin (6.0%). Over time, a significant decreasing trend in resistance to ampicillin was observed (slope = −0.0193, p = 0.011). No significant trends were found for trimethoprim–sulfamethoxazole, cephalexin, amoxicillin–clavulanic acid, ceftriaxone, and cefuroxime. Conclusions: Significant differences in pathogen distribution and resistance patterns between complicated UTI and non-complicated UTI groups highlight the need for continuous resistance monitoring and adherence to local guidelines. For the treatment of severe community F-UTI, ceftriaxone could be a reasonable option for first-onset F-UTI. Further studies are needed to implement antibiotic stewardship and optimize usage. [ABSTRACT FROM AUTHOR]

Simple Summary: Standard wound management involving topical antibiotics or essential oils can enhance the healing process. Organic plant oil extracts, such as totarol, have demonstrated efficacy in wound healing as adjunctive treatments. This study focuses on evaluating the antibacterial properties of totarol and its efficacy in clinical wound healing in dogs. This result reveals that totarol exhibited antimicrobial activity against both standard pathogens and clinical wound pathogens. Clinically, the use of totarol as an adjunctive therapy significantly improved wound healing, as indicated by a greater percentage of wound area reduction. This study investigates the susceptibility of common pathogens to totarol and assesses its clinical effectiveness in promoting wound healing in client-owned dogs with open wounds. Twenty-three client-owned dogs with open wounds were divided into two groups: (1) the treatment group (T-group) and (2) the control group (C-group). Clinical samples were collected from the wounds for the bacterial identification and determination of the minimum inhibitory concentrations (MICs) of totarol. In the T-group, wounds were treated with standard wound care together with the application at a dosage of 0.3 mL (two sprays) of commercial totarol product per 25 cm2 of the wound area. The C-group received only standard wound care. This in vitro study found that totarol exhibited antimicrobial activity against both standard pathogens and clinical wound pathogens. The MIC values of totarol dissolved in absolute ethyl alcohol were 4 µg/mL for Gram-positive pathogens and ranged from 256 to 512 µg/mL for Gram-negative pathogens. However, the MIC values of the commercial totarol product ranged from 512 to 1024 for both Gram-positive and Gram-negative pathogens. Clinically, the use of a commercial totarol product as an adjunctive therapy significantly improved wound healing, as indicated by a greater percentage of wound area reduction (p < 0.05). From day 2 to day 7 of the treatment, the percentage of wound area reduction differed significantly between the T-group and the C-group. At the end of the study, the average percentage of wound area reduction was 69.18% ± 18.12 and 41.50% ± 20.23 in the T-group and C-group, respectively. The finding of this study illustrates the antimicrobial properties of totarol and its product against prevalent wound pathogens. These results suggest the potential of totarol as an adjunctive option for canine wound care. [ABSTRACT FROM AUTHOR]

Antibiotic misuse in Romania has exacerbated the issue of antibiotic resistance, as patients often use antibiotics without proper medical consultation. This study aimed to assess the resistance of prevalent bacteria to different antibiotics. In this observational study conducted over six months, we analyzed 31 pediatric patients aged from 12 days to 13 years using the disk diffusion method. We identified 31 bacterial isolates, including 8 Gram-negative and 8 Gram-positive strains, with the most common being Pseudomonas aeruginosa, Escherichia coli, Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, Streptococcus species, and Elizabethkingia meningoseptica. Our findings revealed that the most effective antibiotics were linezolid, ertapenem, and teicoplanin. In contrast, nearly all tested bacteria exhibited resistance to penicillin, followed by oxacillin and ampicillin. Resistance to cephalosporins varied with generation, showing higher resistance to lower-generation cephalosporins. The study highlights significant antibiotic resistance among common bacterial pathogens in Romanian pediatric patients, emphasizing the urgent need for controlled antibiotic use and alternative treatment strategies to combat this growing issue. Effective antibiotics such as linezolid and ertapenem offer potential solutions, whereas reliance on penicillin and lower-generation cephalosporins is increasingly futile. [ABSTRACT FROM AUTHOR]

Endolysin, a bacteriophage-derived lytic enzyme, has emerged as a promising alternative antimicrobial agent against rising multidrug-resistant bacterial infections. Two novel endolysins LysPEF1-1 and LysPEF1-2 derived from Enterococcus phage PEF1 were cloned and overexpressed in Escherichia coli to test their antimicrobial efficacy against multidrug-resistant E. faecalis strains and their biofilms. LysPEF1-1 comprises an enzymatically active domain and a cell-wall-binding domain originating from the NLPC-P60 and SH3 superfamilies, while LysPEF1-2 contains a putative peptidoglycan recognition domain that belongs to the PGRP superfamily. LysPEF1-1 was active against 89.86% (62/69) of Enterococcus spp. tested, displaying a wider antibacterial spectrum than phage PEF1. Moreover, two endolysins demonstrated lytic activity against additional gram-positive and gram-negative species pretreated with chloroform. LysPEF1-1 showed higher activity against multidrug-resistant E. faecalis strain E5 than LysPEF1-2. The combination of two endolysins effectively reduced planktonic cells of E5 in broth and was more efficient at inhibiting biofilm formation and removing biofilm cells of E. faecalis JCM 7783T than used individually. Especially at 4 °C, they reduced viable biofilm cells by 4.5 log after 2 h of treatment on glass slide surfaces. The results suggest that two novel endolysins could be alternative antimicrobial agents for controlling E. faecalis infections. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance poses a major threat to global health and food security and is primarily driven by antimicrobial use in human and veterinary medicine. Understanding its epidemiology at farm level is crucial for effective control measures. Despite the significant reduction in antibiotic use in conventional livestock production, the swine sector traditionally has a higher level of antibiotic use in veterinary medicine. Consequently, multidrug resistance (MDR) among microbial isolates of swine origin has been relatively frequent. The aim of this study was to assess the presence of multidrug-resistant (MDR) bacteria, enteric pathogens and resistance genes to the main antibiotics used in clinical practice, both within the environment and in animals across pig farms characterized by varying degrees of sanitary status. A total of 274 samples were collected. Of these, 34 samples were collected from the environment (wall swabs, slat swabs and slurry pit), and 240 samples were collected from animals (sows' and piglets' rectal faeces). All samples were analysed for MDR bacteria and enteric pathogens. The study revealed a high frequency of extended-spectrum beta-lactamases (ESBL)-producing Enterobacterales and Campylobacter spp., with ESBL-producing Enterobacterales predominating in high health status farms (environment and animals) and Campylobacter spp. in both high health status and low health status environments. Additionally, a high percentage of methicillin-resistant Staphylococcus aureus (MRSA) was found, mainly in environmental samples from high health status farms, and Clostridioides difficile was distributed ubiquitously among farms and samples. Furthermore, though less frequently, vancomycin-resistant Enterococcus faecium (VRE) was isolated only in high health status farms, and Gram-negative bacilli resistant to carbapenems were isolated only in environmental samples of high health status and low health status farms. This study underscores the importance of surveillance for MDR bacteria in farm animals and their environment, including their waste. Such ecosystems serve as crucial reservoirs of bacteria, requiring national-level surveillance to promote responsible antibiotic use and pandemic control. [ABSTRACT FROM AUTHOR]

VIM-type-producing Gram-negative bacteria (GNB) infections are difficult to treat. This is a retrospective single-center study of 34 patients who received cefiderocol for the treatment of VIM-type-producing GNB infections, including 25 Pseudomonas spp., 7 Enterobacterales, and 5 Achromobacter sp. Primary outcomes were clinical failure (defined as death, lack of clinical improvement, or a switch to another drug) at day 14 and 30-day all-cause mortality. The median age was 59 years (IQR 53.7–73.4), and the median Charlson comorbidity index was 3.5 (IQR 2–5). The main infections were respiratory tract infections (n = 9, 27%) and skin and soft tissue infections (n = 9, 27%). Eight patients exhibited bacteremia. In 9/17 patients with a drainable focus, drainage was performed. The median cefiderocol treatment duration was 13 days (IQR 8–24). Five patients (15%) experienced clinical failure on day 14, and the thirty-day mortality rate was 9/34 (27%); two cases occurred because of an uncontrolled infection source, and one was due to a new infection caused by the same bacteria. The other six deaths were unrelated to the index infection. Five patients experienced microbiological recurrence within three months. Susceptibility testing revealed the development of cefiderocol resistance in 1/7 cases with persistent or recurrent positive cultures. Cefiderocol, even in monotherapy, could be considered for the treatment of VIM-type-producing GNB infections. [ABSTRACT FROM AUTHOR]

This study focused on the discovery of the antimicrobial peptide (AMP) derived from mangrove bacteria. The most promising isolate, NNS5-6, showed the closest taxonomic relation to Paenibacillus thiaminolyticus, with the highest similarity of 74.9%. The AMP produced by Paenibacillus thiaminolyticus NNS5-6 exhibited antibacterial activity against various Gram-negative pathogens, especially Pseudomonas aeruginosa and Klebsiella pneumoniae. The peptide sequence consisted of 13 amino acids and was elucidated as Val-Lys-Gly-Asp-Gly-Gly-Pro-Gly-Thr-Val-Tyr-Thr-Met. The AMP mainly exhibited random coil and antiparallel beta-sheet structures. The stability study indicated that this AMP was tolerant of various conditions, including proteolytic enzymes, pH (1.2–14), surfactants, and temperatures up to 40 °C for 12 h. The AMP demonstrated 4 µg/mL of MIC and 4–8 µg/mL of MBC against both pathogens. Time-kill kinetics showed that the AMP acted in a time- and concentration-dependent manner. A cell permeability assay and scanning electron microscopy revealed that the AMP exerted the mode of action by disrupting bacterial membranes. Additionally, nineteen biosynthetic gene clusters of secondary metabolites were identified in the genome. NNS5-6 was susceptible to various commonly used antibiotics supporting the primary safety requirement. The findings of this research could pave the way for new therapeutic approaches in combating antibiotic-resistant pathogens. [ABSTRACT FROM AUTHOR]

Flavonoids are secondary metabolites that exhibit remarkable biological activities, including antimicrobial properties against Klebsiella pneumoniae, a pathogen responsible for several serious nosocomial infections. However, oral administration of these compounds faces considerable challenges, such as low bioavailability and chemical instability. Thus, the encapsulation of flavonoids in nanosystems emerges as a promising strategy to mitigate these limitations, offering protection against degradation; greater solubility; and, in some cases, controlled and targeted release. Different types of nanocarriers, such as polymeric nanoparticles, liposomes, and polymeric micelles, among others, have shown potential to increase the antimicrobial efficacy of flavonoids by reducing the therapeutic dose required and minimizing side effects. In addition, advances in nanotechnology enable co-encapsulation with other therapeutic agents and the development of systems responsive to more specific stimuli, optimizing treatment. In this context, the present article provides an updated review of the literature on flavonoids and the main nanocarriers used for delivering flavonoids with antibacterial properties against Klebsiella pneumoniae. [ABSTRACT FROM AUTHOR]

Sodium hypochlorite (NaOCl) is widely used in public healthcare facilities; this exposure can result in the development of bacterial tolerance to disinfectants, which has known links to antibiotic cross-resistance. However, the mechanism through which cross-resistance to antibiotics and disinfectants develops remains ambiguous. Therefore, this study aimed to examine the phenotypic and transcriptomic changes caused by disinfectant exposure in Gram-negative bacteria and determine the cause of cross-resistance to antibiotics. The results demonstrated that the misuse of disinfectants plays an important role in the emergence of disinfectant resistance and in the increase in antibiotic resistance. Antibiotic resistance may occur from the exposure of Gram-negative bacteria to subminimal inhibitory concentrations (MICs) of NaOCl. Ten passages of Gram-negative bacteria in increasingly higher subMICs of the NaOCl disinfectant were sufficient to increase the MIC to >2500 µg/mL NaOCl, particularly in K. pneumoniae and P. aeruginosa. To determine the development of cross-resistance to antibiotics due to NaOCl exposure, the MICs for each antibiotic before and after the exposure of each strain to sublethal concentrations of NaOCl were compared. After overnight incubation with a sublethal concentration of NaOCl, a statistically significant increase in MIC was only observed for imipenem (p < 0.01). An investigation of the mechanism of cross-resistance by means of transcriptome analysis revealed that 1250 µg/mL of NaOCl-adapted K. pneumoniae and P. aeruginosa strains increased resistance to imipenem due to the increased expression of resistance-nodulation-cell division (RND) efflux pumps, such as AcrAB-TolC and MexAB/XY-OprM. Therefore, we suggest that exposure to NaOCl can influence the expression of RND efflux pump genes, contributing to imipenem cross-resistance. [ABSTRACT FROM AUTHOR]

Infections represent a major complication for burn-injured patients. The aim of this study was to highlight the changes in the incidence and antimicrobial resistance of bacterial strains isolated from burn patients, at the end of the COVID-19 pandemic, in relation to the antibiotics used during the pandemic. A comparative analysis of the demographic data and the microorganisms identified in the clinical samples of two groups of burn patients admitted to a university hospital in Romania was carried out. The first group consisted of 48 patients and the second of 69 patients, hospitalized in January–August 2020 and 2023, respectively. The bacterial species with the highest incidence were S. aureus, A. baumannii, Pseudomonas spp. The significant changes between 2023 and 2020 are reflected in the increase in the frequency of non-fermentative Gram-negative bacteria, especially S. maltophilia, and the increase in antimicrobial resistance of Pseudomonas and Klebsiella spp. Klebsiella spp. did not change in frequency (7%), but there was a significant increase in the incidence of K. pneumoniae strains with pan-drug resistant behaviour to antibiotics (40%), including colistin. The phenomenon can be explained by the selection of specimens carrying multiple resistance genes, as a result of antibiotic treatment during the COVID-19 period. The post-pandemic antimicrobial resistance detected in burn patients indicates the need for permanent surveillance of the resistance trends, primarily due to the limited therapeutic options available for these patients. [ABSTRACT FROM AUTHOR]

The rapid emergence and spread of multidrug-resistant microorganisms is threatening our ability to treat common infections, with serious medical, social, and economic consequences. Despite substantial progress in the global fight against antibiotic resistance, the number of effective antibiotics is rapidly decreasing, underlying the urgent need to develop novel antimicrobials. In the present study, the green synthesis of novel iodine-substituted tricyclic flavonoids has been accomplished using an eco-friendly reagent, HPW-SiO2, as a cyclization agent for the precursor 3-dithiocarmamic flavanones. In vitro antimicrobial activity of the new compounds was evaluated using minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentrations. All tested compounds displayed potent inhibitory activity against all tested microbial strains, with the lowest MIC values of 0.12 µg/mL and 0.48 µg/mL recorded for compound 5c against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus. Higher MIC values (7.81 µg/mL) were registered for several flavonoids against Gram-negative bacteria Escherichia coli and Acinetobacter pittii. No inhibitory activity was evidenced against Pseudomonas aeruginosa strain. The highest antifungal activity was displayed by flavonoid 5d against Candida krusei (MIC = 3.9 µg/mL). The same compound also exhibited the most potent bactericidal and fungicidal activity against Bacillus subtilis (0.9 µg/mL) and Staphylococcus aureus (1.97 µg/mL), Candida albicans, and Candida krusei (7.81 µg/mL). Based on the reported results, we believe that the novel iodine-substituted tricyclic flavonoids have good potential to become new antimicrobial agents effective against bacterial and fungal strains, including WHO-priority pathogens. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a multidrug-resistant Gram-negative pathogen and one of the leading causes of ventilator-associated pneumonia and infections in patients with chronic obstructive pulmonary disease and cystic fibrosis. Murepavadin is a peptidomimetic that specifically targets outer-membrane lipopolysaccharide transport protein LptD of P. aeruginosa. In this study, we find that murepavadin enhances the bactericidal efficacy of ciprofloxacin. We further demonstrate that murepavadin increases intracellular accumulation of ciprofloxacin by suppressing drug efflux. In addition, the murepavadin–ciprofloxacin combination exhibits a synergistic bactericidal effect in an acute murine pneumonia model. In conclusion, our results identify an effective drug combination for the treatment of P. aeruginosa infections. [ABSTRACT FROM AUTHOR]

Objective: The objective was to compare the microbiological characteristics and treatment of early and late surgical site infections (SSIs) in instrumented spinal surgery. Methods: Those patients admitted for SSIs in a single center between January 2010 and December 2022 were included. The subjects were divided into early (eSSIs) and late (lSSIs) SSIs, and demographic, microbiological, treatment, and follow-up data were collected. Results: Instrumented spinal surgery was performed in 2136 patients. Ninety-six cases of infections were identified (prevalence = 4.5%), with 47.9% eSSIs and 52.1% lSSIs. In 58.7% of the cases, the eSSIs were monomicrobial: Staphylococcus aureus (37%) and Enterobacterales (33.3%) were the main bacteria involved. In 66% of the cases, the lSSIs, were monomicrobial: Cutibacterium acnes (30.3%) and staphylococci were predominant. Enterobacterales were isolated in more than 70% of the polymicrobial samples in both the eSSIs and lSSIs. The treatment of the eSSIs mostly consisted of lavage-debridement surgery associated with antibiotic treatment, while the treatment of the lSSIs combined hardware removal or replacement and long-duration antibiotic treatment. A negative outcome was observed in 17.1% of the eSSIs and 5.7% of the lSSIs. Enterobacterales were associated with negative outcomes of eSSIs. Conclusions: Enterobacterales were found in most of the polymicrobial infections regardless of the time of infection onset. Further large studies should be conducted to precisely determine the management and prevention regarding the increasing Gram-negative bacteria SSIs. [ABSTRACT FROM AUTHOR]

The cluster of genes determining the production of botulinum toxins is an attribute of not only the Clostridium botulinum species. This cluster is also found in other members of the Clostridium genus, such as C. baratii, C. butyricum, and C. sporogenes. The occurrence of a botulinum-like cluster has also been recorded in strains of other genera, i.e., Enterococcus faecium, as well as in a Gram-negative species isolated from freshwater sediments; however, the biological activity of bont-related genes has not been noted. It can be said that the mentioned species have a dual nature. Another species with a dual nature is C. butyricum. This bacterium is a common human and animal gut commensal bacterium and is also frequently found in the environment. Although non-toxigenic strains are currently used as probiotics in Asia, other strains have been implicated in pathological conditions, such as botulism in infants or necrotizing enterocolitis in preterm neonates. Additionally, C. baratii strains are rare opportunistic pathogens associated with botulism intoxication. They have been isolated from food and soil and can be carried asymptomatically or cause botulism outbreaks in animals and humans. In addition to the mentioned clostridia, the other microorganisms considered as non-toxigenic have also been suspected of carrying botulinum cluster Gram-negative bacteria, such as Chryseobacterium piperi isolated from freshwater sediments; however, the biological activity of bont-related genes has not been noted. Additionally, Enterococcus faecium strains have been discovered carrying BoNT-related clusters (BoNT/En). Literature data regarding the heterogeneity of BoNT-producing strains indicate the requirement to reclassify C. botulinum species and other microorganisms able to produce BoNTs or possess botulinum-like gene clusters. This article aims to show the dual nature of Clostridium strains not belonging to the C. botulinum species that are sporadically able to carry bont clusters, which are usually considered saprophytic and even probiotic, and bont-like clusters in microorganisms from other genera. The aim was also to consider the genetic mechanisms of botulinum cluster expression in strains that are considered opportunistic and the microbiological safety aspects associated with their occurrence in the environment. [ABSTRACT FROM AUTHOR]

This review strives to assemble a set of molecular design principles that enables the delivery of antibiotic warheads to Gram-negative bacterial targets (ESKAPE pathogens) using iron-chelating siderophores, known as the Trojan Horse strategy for antibiotic development. Principles are derived along two main lines. First, archetypical siderophores and their conjugates are used as case studies for native iron transport. They enable the consideration of the correspondence of iron transport and antibacterial target location. The second line of study charts the rationale behind the clinical antibiotic cefiderocol. It illustrates the potential versatility for the design of new Trojan Horse-based antibiotics. Themes such as matching the warhead to a location where the siderophore delivers its cargo (i.e., periplasm vs. cytoplasm), whether or not a cleavable linker is required, and the relevance of cheaters to the effectiveness and selectivity of new conjugates will be explored. The effort to articulate rules has identified gaps in the current understanding of iron transport pathways and suggests directions for new investigations. [ABSTRACT FROM AUTHOR]

The increasing emergence of multidrug-resistant (MDR) pathogens due to antibiotic misuse translates into obstinate infections with high morbidity and high-cost hospitalizations. To oppose these MDR superbugs, new antimicrobial options are necessary. Although both quaternary ammonium salts (QASs) and phosphonium salts (QPSs) possess antimicrobial effects, QPSs have been studied to a lesser extent. Recently, we successfully reported the bacteriostatic and cytotoxic effects of a triphenyl phosphonium salt against MDR isolates of the Enterococcus and Staphylococcus genera. Here, aiming at finding new antibacterial devices possibly active toward a broader spectrum of clinically relevant bacteria responsible for severe human infections, we synthesized a water-soluble, sterically hindered quaternary phosphonium salt (BPPB). It encompasses two triphenyl phosphonium groups linked by a C12 alkyl chain, thus embodying the characteristics of molecules known as bola-amphiphiles. BPPB was characterized by ATR-FTIR, NMR, and UV spectroscopy, FIA-MS (ESI), elemental analysis, and potentiometric titrations. Optical and DLS analyses evidenced BPPB tendency to self-forming spherical vesicles of 45 nm (DLS) in dilute solution, tending to form larger aggregates in concentrate solution (DLS and optical microscope), having a positive zeta potential (+18 mV). The antibacterial effects of BPPB were, for the first time, assessed against fifty clinical isolates of both Gram-positive and Gram-negative species. Excellent antibacterial effects were observed for all strains tested, involving all the most concerning species included in ESKAPE bacteria. The lowest MICs were 0.250 µg/mL, while the highest ones (32 µg/mL) were observed for MDR Gram-negative metallo-β-lactamase-producing bacteria and/or species resistant also to colistin, carbapenems, cefiderocol, and therefore intractable with currently available antibiotics. Moreover, when administered to HepG2 human hepatic and Cos-7 monkey kidney cell lines, BPPB showed selectivity indices > 10 for all Gram-positive isolates and for clinically relevant Gram-negative superbugs such as those of E. coli species, thus being very promising for clinical development. [ABSTRACT FROM AUTHOR]

We investigated the activity of cefiderocol/β-lactamase inhibitor combinations against clinical strains with different susceptibility profiles to cefiderocol to explore the potentiality of antibiotic combinations as a strategy to contain the major public health problem of multidrug-resistant (MDR) pathogens. Specifically, we evaluated the synergistic activity of cefiderocol with avibactam, sulbactam, or tazobactam on three of the most "Critical Priority" group of MDR bacteria (carbapenem-resistant Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii). Clinical isolates were genomically characterized by Illumina iSeq 100. The synergy test was conducted with time-kill curve assays. Specifically, cefiderocol/avibactam, /sulbactam, or /tazobactam combinations were analyzed. Synergism was assigned if bacterial grow reduction reached 2 log10 CFU/mL. We reported the high antimicrobial activity of the cefiderocol/sulbactam combination against carbapenem-resistant Enterobacterales, P. aeruginosa, and A. baumannii; of the cefiderocol/avibactam combination against carbapenem-resistant Enterobacterales; and of the cefiderocol/tazobactam combination against carbapenem-resistant Enterobacterales and P. aeruginosa. Our results demonstrate that all β-lactamase inhibitors (BLIs) tested are able to enhance cefiderocol antimicrobial activity, also against cefiderocol-resistant isolates. The cefiderocol/sulbactam combination emerges as the most promising combination, proving to highly enhance cefiderocol activity in all the analyzed carbapenem-resistant Gram-negative isolates, whereas the Cefiderocol/tazobactam combination resulted in being active only against carbapenem-resistant Enterobacterales and P. aeruginosa, and cefiderocol/avibactam was only active against carbapenem-resistant Enterobacterales. [ABSTRACT FROM AUTHOR]

Solidago virgaurea L., or European goldenrod, has a long tradition in folk medicine due to the wide range of its biological activity. This paper aimed to investigate the antimicrobial and antioxidative potential of S. virgaurea essential oil and hydrolates obtained by traditional and novel extraction techniques. For that purpose, hydrodistillation, microwave-assisted hydrodistillation and solvent-free extraction were performed. Analysis of the composition of essential oils indicated the presence of 59 different compounds with cyclocolorenone, germacrene D and spathulenol being the dominant in all essential oil samples. Antimicrobial activity was detected in all the analyzed samples, with higher effect on Gram-positive microorganisms compared to Gram-negative. Regarding the type of performed extraction process, the introduction of microwaves induced higher antimicrobial and antioxidative potential in both essential oils and hydrolates. Hydrolates obtained in microwave-assisted processes had pronounced antioxidative activity, which creates a good basis for further investigation of this side product's potential use in the food, cosmetic and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Microbial infections pose a significant global health threat, affecting millions of individuals and leading to substantial mortality rates. The increasing resistance of microorganisms to conventional treatments requires the development of novel antimicrobial agents. Pyrroloquinoline quinone (PQQ), a natural medicinal drug involved in various cellular processes, holds promise as a potential antimicrobial agent. In the present study, our aim was, for the first time, to explore the antimicrobial activity of PQQ against 29 pathogenic microbes, including 13 fungal strains, 8 Gram-positive bacteria, and 8 Gram-negative bacteria. Our findings revealed potent antifungal properties of PQQ, particularly against Syncephalastrum racemosum, Talaromyces marneffei, Candida lipolytica, and Trichophyton rubrum. The MIC values varied between fungal strains, and T. marneffei exhibited a lower MIC, indicating a greater susceptibility to PQQ. In addition, PQQ exhibited notable antibacterial activity against Gram-positive and -negative bacteria, with a prominent inhibition observed against Staphylococcus epidermidis, Proteus vulgaris, and MRSA strains. Remarkably, PQQ demonstrated considerable biofilm inhibition against the MRSA, S. epidermidis, and P. vulgaris strains. Transmission electron microscopy (TEM) studies revealed that PQQ caused structural damage and disrupted cell metabolism in bacterial cells, leading to aberrant morphology, compromised cell membrane integrity, and leakage of cytoplasmic contents. These findings were further affirmed by shotgun proteomic analysis, which revealed that PQQ targets several important cellular processes in bacteria, including membrane proteins, ATP metabolic processes, DNA repair processes, metal-binding proteins, and stress response. Finally, detailed molecular modeling investigations indicated that PQQ exhibits a substantial binding affinity score for key microbial targets, including the mannoprotein Mp1P, the transcriptional regulator TcaR, and the endonuclease PvuRTs1I. Taken together, our study underscores the effectiveness of PQQ as a broad-spectrum antimicrobial agent capable of combating pathogenic fungi and bacteria, while also inhibiting biofilm formation and targeting several critical biological processes, making it a promising therapeutic option for biofilm-related infections. [ABSTRACT FROM AUTHOR]

Achillea cucullata is a perennial herbaceous plant that has a long history of medical use in many cultures. The present research focuses on the biological activity and therapeutic potential of A. cucullata, namely its antibacterial and anticancer properties. While previous studies have shed light on the cytotoxic and antibacterial capabilities of Achillea cucullata aerial parts, there is still a considerable gap in knowledge concerning the anticancer potential of leaf and flower extracts. A. cucullata's leaves and flowers were extracted using methanol. The total phenolic and flavonoid contents were evaluated. The antioxidant, cytotoxic, and antibacterial properties were evaluated against both Gram-positive and Gram-negative bacteria. The Gas Chromatography–Mass Spectrometry (GC–MS) analysis of A. cucullata leaf and flower extracts showed numerous amounts of bioactive components, including carvacrol, a TBDMS derivative; 2-Myristynoyl-glycinamide, acetylaminobenzothiazol-2-yl)-2-(adamantan-1-yl); Isolongifolol; (3E,10Z)-Oxacyclotrideca-3,10-diene-2,7-dione; and 3-Heptanone, 5-hydroxy-1,7-diphenyl. The extract has a high level of phenols and flavonoids. Cytotoxicity studies found that A. cucullata leaves and flowers had dose-dependent toxicity against MCF-7 and HepG2 cancer cell lines, with flowers being more effective. Apoptotic genes (caspase-3, 8, 9, and Bax) were upregulated in treated MCF-7 and HepG2 cells, whereas anti-apoptotic genes (Bcl-xL and Bcl-2) were reduced. Antibacterial screening revealed significant activity against both Gram-positive and Gram-negative pathogens. Overall, the research highlights the varied therapeutic potentials of A. cucullata, adding to the knowledge of plant-derived extracts in lowering disease risks. Future research should concentrate on in vivo studies to assess the effectiveness and safety of these substances. [ABSTRACT FROM AUTHOR]

This study reports for the first time the isolation of four diterpenoid compounds: 15-Hydroxy-12-oxo-abietic acid (1), 12α-hydroxyabietic acid (2), (−)-Jolkinolide E (3), and 15-Hydroxydehydroabietic acid (4) from Clinopodium bolivianum (C. bolivianum). The findings demonstrate that both the dichloromethane/methanol (DCMECB) extract of C. bolivianum and the isolated compounds exhibit significant anti-inflammatory (inhibition of NF-κB activation), antibacterial (primarily against Gram-positive bacteria), and anti-biofilm (primarily against Gram-negative bacteria) activities. Among the isolated diterpenes, compounds 3 and 4 showed notable anti-inflammatory effects, with IC50 values of 17.98 μM and 23.96 μM for compound 3, and 10.79 μM and 17.37 μM for compound 4, in the HBEC3-KT and MRC-5 cell lines. Regarding their antibacterial activity, compounds 3 and 4 were particularly effective, with MIC values of 0.53–1.09 μM and 2.06–4.06 μM, respectively, against the S. pneumoniae and S. aureus Gram-positive bacteria. Additionally, these compounds demonstrated significant anti-biofilm and anti-quorum sensing activities, especially against Gram-negative bacteria (H. influenzae and L. pneumophila). We also explain how compound 3 (BIC = 1.50–2.07 μM, Anti-QS = 0.31–0.64 μM) interferes with quorum sensing due to its structural homology with AHLs, while compound 4 (BIC = 4.65–7.15 μM, Anti-QS = 1.21–2.39 μM) destabilises bacterial membranes due to the presence and position of its hydroxyl groups. These results support the traditional use of C. bolivianum against respiratory infections caused by both Gram-positive and Gram-negative bacteria. Furthermore, given the increasing antibiotic resistance and biofilm formation by these bacteria, there is a pressing need for the development of new, more active compounds. In this context, compounds 3 and 4 isolated from C. bolivianum offer promising potential for the development of a library of new, more potent, and selective drugs. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas aeruginosa (P. aeruginosa), is a diverse Gram-negative pathogen commonly associated with a wide spectrum of infections. It is indicated to be the most prevalent causative agent in the development of bacterial keratitis linked with the use of contact lens. Corneal infections attributed to P. aeruginosa frequently have poor clinical outcomes necessitating lengthy and costly therapies. Therefore, this review looks at the aetiology of P. aeruginosa bacterial keratitis as well as the bacterial drivers of its virulence and the potential therapeutics on the horizon. Method: A literature review with the articles used for the review searched for and retrieved from PubMed, Scopus, and Google Scholar (date last accessed 1 April 2024). The keywords used for the search criteria were "Pseudomonas and keratitis, biofilm and cornea as well as P. aeruginosa". Results: P. aeruginosa is implicated in the pathogenesis of bacterial keratitis associated with contact lens usage. To reduce the potential seriousness of these infections, a variety of contact lens-cleaning options are available. However, continuous exposure to a range of antibiotics doses, from sub-inhibitory to inhibitory, has been shown to lead to the development of resistance to both antibiotics and disinfectant. Generally, there is a global public health concern regarding the rise of difficult-to-treat infections, particularly in the case of P. aeruginosa virulence in ocular infections. This study of the basic pathogenesis of a prevalent P. aeruginosa strain is therefore implicated in keratitis. To this effect, anti-virulence methods and phage therapy are being researched and developed in response to increasing antibiotic resistance. Conclusion: This review has shown P. aeruginosa to be a significant cause of bacterial keratitis, particularly among users of contact lens. It also revealed treatment options, their advantages, and their drawbacks, including prospective candidates. [ABSTRACT FROM AUTHOR]

The goal of this research was to analyse the synergistic effect between selected plant extracts with zinc oxide particles, and zinc stearate. The influence of ZnO on the antimicrobial effectiveness of the selected extracts was confirmed in previous research carried out by the authors. However, the impact of zinc stearate on extract activity has yet to be analysed. The aim was to cover PLA films with active coatings based on hydroxy-propyl-methyl-cellulose (HPMC), or/and ethyl cellulose (EC) containing plant extracts and ZnO which has a synergistic effect. An additional aim was to use a CO2 extract of raspberry seed (RSE) with zinc stearate as active additives within the coatings. An examination of the antimicrobial properties (against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas syringae and Φ6 bacteriophage) of the covered films, as well as an investigation of layer presence with regards to PLA morphology (SEM, ATR-FTIR analysis) was carried out. The research work that was performed indicated that black chokeberry extract (ChE) and zinc oxide particles were effective against S. aureus, P. syringae and B. subtilis strains. In addition, the ChE with zinc stearate (ZnSt) was active against all analysed strains. The HPMC with ChE and ZnO as additives had antimicrobial properties against S. aureus, P. syringae and E. coli strains. The ChE was found to inhibit the growth of all of the analysed bacterial strains. When considering the coatings based on EC with the CO2 extract of raspberry seed (RSE) and ZnO, it was noted that they were only active against Gram-negative bacteria. The results of the experiments confirmed that AC1 (EC with RSE with ZnO) and AC2 (EC with RSE with ZnSt) coatings were not active against a phi6 bacteriophage. The HPMC coating containing the AC3 layer (ChE and ZnO) eliminated Φ6 particles, confirming its antiviral properties. In addition, the presence of the active (AC1, AC2 and AC3) coatings was confirmed by SEM and FTIR analysis. [ABSTRACT FROM AUTHOR]

In this study, a comparative analysis of silver nanoparticles treatment and chitosan coating on packaging paper barrier properties was carried out. In order to examine the water, grease, and antibacterial barrier properties of silver nanoparticle-treated and chitosan-coated laboratory-obtained paper samples, a mixture of bleached softwood and hardwood celluloses was used. In order to conduct the comparative analysis SEM, water contact angle, Cobb60, and Kit tests were carried out on a cellulose sample, and four paper samples (three of them treated with silver nanoparticles—1, 2, and 3 mL/20 cm2 or chitosan coated—0.5, 1, and 2 g/m2) together with the inhibition activity against nine Gram-positive and Gram-negative bacteria, yeast, and fungal strains. The study found out that increasing the silver nanoparticle treatment and chitosan coating led to improved water resistance, while grease resistance was improved only for chitosan coated paper samples. Additionally, paper treated with 3 mL/20 cm2 of silver nanoparticles had the highest antibacterial protection (81.6%) against the Gram-positive bacterium Staphylococcus aureus, followed by Gram-negative Escherichia coli (75.8%). For the rest of the studied microorganisms, the average efficiency of the treated paper was 40.79%. The treatment of the paper with 1 and 2 mL/20 cm2 of silver nanoparticles was less effective—27.13 and 39.83%, respectively. The antibacterial protection of 2 g/m2 chitosan-coated paper samples was the most effective (average 79%) against the tested bacterial, yeast, and fungal strains. At 1 and 0.5 g/m2 chitosan coatings, the efficiency was 72.38% and 54.67%, respectively. Gram-positive bacteria, yeasts, and fungal strains were more sensitive to chitosan supplementation. [ABSTRACT FROM AUTHOR]

Herein, we report an efficient and facile strategy for the preparation of imidazolium-based ionic liquid (IL) monomers ([CnVIm][Br], n = 2, 4, 6, 8, 10, and 12) and their corresponding polymeric ionic liquids (PILs) with potent antimicrobial activities against Gram-negative and Gram-positive bacteria and fungi. The electrospinning technique was utilized to tailor the polymers with the highest antimicrobial potency into porous membranes that can be easily implemented into diverse systems and extend their practical bactericidal application. The antimicrobial mechanism of obtained ILs, polymers, and nanomaterials is considered concerning the bearing chain length, polymerization process, and applied processing technique that provides a unique fibrous structure. The structure composition was selected due to the well-established inherent amphiphilicity that 1-alkylimidazolium ILs possess, coupled with proven antimicrobial, antiseptic, and antifungal behavior. The customizable nature of ILs and PILs complemented with electrospinning is exploited for the development of innovative antimicrobial performances born from the intrinsic polymer itself, offering solutions to the increasing challenge of bacterial resistance. This study opens up new prospects toward designer membranes providing a complete route in their designing and revolutionizing the approach of fabricating multi-functional systems with tunable physicochemical, surface properties, and interesting morphology. [ABSTRACT FROM AUTHOR]

The spread of multidrug-resistant mycobacterium strains requires the development of new approaches to combat diseases caused by these pathogens. For that, photodynamic inactivation (PDI) is a promising approach. In this study, a tricarbocyanine (TCC) is used for the first time as a near-infrared (740 nm) activatable PDI photosensitizer to kill mycobacteria with deep light penetration. For better targeting, a novel tricarbocyanine dye functionalized with two trehalose units (TCC2Tre) is developed. The photodynamic effect of the conjugates against mycobacteria, including Mycobacterium tuberculosis, is evaluated. Under irradiation, TCC2Tre causes more effective killing of mycobacteria compared to the photosensitizer without trehalose conjugation, with 99.99% dead vegetative cells of M. tuberculosis and M. smegmatis. In addition, effective photoinactivation of dormant forms of M. smegmatis is observed after incubation with TCC2Tre. Mycobacteria treated with TCC2Tre are more sensitive to 740 nm light than the Gram-positive Micrococcus luteus and the Gram-negative Escherichia coli. For the first time, this study demonstrates the proof of principle of in vitro PDI of mycobacteria including the fast-growing M. smegmatis and the slow-growing M. tuberculosis using near-infrared activatable photosensitizers conjugated with trehalose. These findings are useful for the development of new efficient alternatives to antibiotic therapy. [ABSTRACT FROM AUTHOR]

The first example of applying salicylaldehyde derivatives, as well as coumarin with the formyl group at the C8 position in its structure, as carbonyl partners in a three-component Passerini reaction, is presented. As a result of research on the conditions of the Passerini reaction, the important role of the hydroxyl group in the salicylaldehyde used in the course of the multicomponent reaction was revealed. When an aldehyde with an unprotected hydroxyl group is used, only two-component α-hydroxy amide products are obtained. In contrast, the use of acylated aldehyde results in three-component α-acyloxy amide products with high efficiency. The developed protocol gives access to structurally diversified peptidomimetics with good yield. The compounds were also evaluated as antimicrobial agents against selected strains of nosocomial pathogenic bacteria. The structure–activity relationship revealed that inhibitory activity is strongly related to the presence of the trifluoromethyl group (CF3) or the methyl group at the C4 position in an unsaturated lactone ring of the coumarin scaffold. MIC and MBC studies were carried out on eight selected pathogenic bacteria strains (Gram-positive pathogenic Staphylococcus aureus strain (ATCC 23235), as well as on Gram-negative E. coli (K12 (ATCC 25404), R2 (ATCC 39544), R3 (ATCC 11775), and R4 (ATCC 39543)), Acinetobacter baumannii (ATCC 17978), Pseudomonas aeruginosa (ATCC 15442), and Enterobacter cloacae (ATCC 49141) have shown that the tested compounds show a strong bactericidal effect at low concentrations. Among all agents investigated, five exhibit higher antimicrobial activity than those observed for commonly used antibiotics. It should be noted that all the compounds tested showed very high activity against S. aureus, which is the main source of nosocomial infections that cause numerous fatalities. Additionally, the cytotoxicity of sixteen derivatives was measured with the use of the MTT test on BALB/c3T3 mouse fibroblast cell lines. The cytotoxicity studies revealed that the tested substances exert a similar or lower effect on cell proliferation than that observed for commonly used antibiotics within the range of therapeutic doses. A parallel MTT assay using ciprofloxacin, bleomycin, and cloxacillin showed that these antibiotics are more cytotoxic when tested in mammalian cells, and cell viability is in the range of 85.0–89.9%. Furthermore, we have shown that the studied coumarin-based peptidomimetics, depending on their structural characteristics, are nonselective and act efficiently against various Gram-positive and Gram-negative pathogens, which is of great importance for hospitalised patients. [ABSTRACT FROM AUTHOR]

Transparent films with excellent antibacterial properties and strong mechanical properties are highly sought after in packaging applications. In this study, Ag/SiO2 nanoparticles were introduced into a mixed solution of chitosan (CS) and polyvinyl alcohol (PVA) and a Ag/SiO2-CS-PVA transparent film was developed. The excellent properties of the film were confirmed by light transmittance, water contact angle tests and tensile tests. In addition, for the antibacterial test, the antibacterial properties of the sample against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were explored, and the average size of the bacteriostatic circle was measured by the cross method. The final results show that Ag/SiO2-CS-PVA transparent film has the advantages of good antibacterial properties, high transparency and high mechanical strength. [ABSTRACT FROM AUTHOR]

Timely pathogen identification in bloodstream infections is crucial for patient care. A comparison is made between positive blood culture (BC) pellets from serum separator tubes using a direct identification (DI) method and colonies on agar plates from a short-term incubation (STI) method with a matrix-assisted laser desorption/ionization Biotyper for the evaluation of 354 monomicrobial BCs. Both the DI and STI methods exhibited similar identification rates for different types of bacteria, except for Gram-positive and anaerobic bacteria. The DI method's results aligned closely with the STI method's results for Enterobacterales, glucose-non-fermenting Gram-negative bacilli (GNB), and carbapenem-resistant Enterobacterales. The DI method exhibited high concordance with the conventional method for GNB identification, achieving 88.2 and 87.5% accuracy at the genus and species levels, respectively. Compared with the STI method, the DI method showed a less successful performance for Gram-positive bacterial identification (50.5 vs. 71.3%; p < 0.01). The DI method was useful for anaerobic bacterial identification of slow-growing microorganisms without any need for colony growth, unlike in the STI method (46.7 vs. 13.3%; p = 0.04). However, both methods could not identify yeast in positive BCs. Overall, the DI method provided reliable results for GNB identification, offering many advantages over the STI method by significantly reducing the turnaround time and enabling quicker pathogen identification in positive BCs. [ABSTRACT FROM AUTHOR]