Resistant Bacterial Strains Research Articles

AIE-Active Antibacterial Photosensitizer Disrupting Bacterial Structure: Multicenter Validation against Drug-Resistant Pathogens.

Antimicrobial resistance (AMR) has emerged as a global challenge in treating bacterial infections, creating an urgent need for broad-spectrum antimicrobial agents that can effectively combat multidrug-resistant (MDR) bacteria. Despite advancements in novel antimicrobial agents, many fail to comprehensively cover common resistant bacterial strains or undergo rigorous multi-center validation. Herein, a cationic AIE-active photosensitizers are developed, ITPM, derived from a triphenylamine-pyridine backbone to address the MDR challenge. Rigorous validation demonstrates that ITPM possesses superior fluorescence imaging capabilities and exceptional antibacterial efficacy. And its broad-spectrum activity is verified through a multi-center study involving six clinically relevant MDR strains. Additionally, resistance development studies and comparisons with advanced clinical antibiotics reveal that ITPM exhibits potent, broad-spectrum antimicrobial activity with minimal resistance development. This efficacy is attributed to its unique antibacterial mechanism involving disrupting bacterial internal structures. These findings establish ITPM as a promising candidate for broad-spectrum antimicrobial therapy, offering a potential solution to the growing crisis of AMR in clinical settings.

Studying the Implications of Antibiotics Resistance in Dental Infection

Background:Antibiotic resistance is a global health issue, complicating infection management, including dental infections. Overuse or misuse of antibiotics in dentistry has led to resistant strains, highlighting the importance of proper treatment to prevent severe complications. Objective:This study aims to assess the prevalence of antibiotic resistance in dental infections and evaluate its implications on clinical outcomes, therapeutic efficacy, and future dental treatment protocols. Method:This cross-sectional study examined antibiotic resistance in dental infections among 200 patients (aged 18–65) from 2023 to 2024. Samples from abscesses, periodontitis, and periapical infections were cultured, and bacterial isolates were identified through Gram staining and biochemical tests. Antibiotic susceptibility was assessed using the Kirby-Bauer method. Resistance genes were analyzed via PCR, and data were evaluated using SPSS version 26.0. Results:Out of 200 samples, 68% (n = 136) showed resistance to at least one antibiotic. Penicillin had the highest resistance (45%), followed by clindamycin (32%) and amoxicillin (28%). Metronidazole had the lowest (11%). PCR identified blaTEM (38%), ermB (25%), and tetM (20%). Patients with prior antibiotic use had a 2.5-fold higher risk of resistant strains. Conclusion:Antibiotic resistance is a growing concern in dental practice, with significant implications for the management of dental infections. The findings suggest that overuse of antibiotics may not only contribute to resistance but also lead to complications that require more invasive treatments. This study highlights the need for stricter antibiotic stewardship in dental care and the exploration of alternative therapies to combat resistant bacterial strains in dental infections

Cytotoxic and antibacterial activity of naturally occurring agglutinin produced from the root of Rhizophora mucronata Poir

Lectins are naturally occurring agglutinins which are produced more from plants sources compared to animal sources. The present study aims to screen the potential applications of lectin isolated from the mangrove plant, Rhizophora mucronata Poir. This root agglutinin of R. mucronata showed highest HA titre with buffalo erythrocytes. The agglutinin activity was pH dependent, thermolabile, calcium dependent and sensitive to divalent EDTA chelators. The agglutinability was dominantly inhibited by simple sugars, glucose and melibiose. The agglutinin was partially purified by biospecific adsorption using formalinized buffalo erythrocytes yield 21.81 fold increase in activity. Purified R. mucronata root lectin (RmrL) showed cytotoxic activity against HeLa (Cervical cancer) cell lines (IC50 value-161.305 µg/ml) and also exhibited antimicrobial activity against multidrug resistant bacterial strains.

Chemical Characterization and Antimicrobial Activity of Green Propolis from the Brazilian Caatinga Biome.

Green propolis, particularly from the unique flora of the Brazilian Caatinga biome, has gained significant interest due to its diverse chemical composition and biological activities. This study focuses on the chemical characterization and antimicrobial evaluation of Caatinga green propolis. Twelve compounds were isolated through different chromatographic techniques, including flavanones (naringenin, 7-O-methyleriodictyol, sakuranetin), flavones (hispidulin, cirsimaritin), flavonols (quercetin, quercetin-3-methyl ether, kaempferol, 6-methoxykaempferol, viscosine, penduletin), and one chalcone (kukulkanin B). Using liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-QToF-MS), a total of 55 compounds excluding reference standards were tentatively identified, which include flavonoids, phenolic acids derivatives, and alkaloids, with flavonols, flavanones, and flavones being predominant. Antimicrobial testing against pathogens revealed that the crude extract exhibited low inhibitory activity, against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) (IC50: 148.4 and 120.98 µg/mL, respectively). Although the isolated compounds showed limited individual activity, a fraction containing sakuranetin and penduletin (Fraction 8) exhibited moderated activity against Cryptococcus neoformans (IC50: 47.86 µg/mL), while a fraction containing quercetin and hispidulin showed moderated activity against VRE (IC50: 16.99 µg/mL). These findings highlight the potential application of Caatinga green propolis as an antimicrobial agent, particularly against resistant bacterial strains, and underscore the importance of synergistic interactions between compounds in enhancing biological effects.

Non-peroxide antibacterial activity of honey produced by an Afrotropical stingless bee, Meliponula (Axestotrigona) ferruginea

Honey is a medicinal food that is widely utilized in traditional and complementary medicine. Amidst the contemporary challenge of antibiotic resistance, honey emerges as a promising natural antimicrobial agent. The efficacy of honey in therapy hinges on its mechanisms of antimicrobial activity. Therefore, this study investigated the non-peroxide antibacterial properties of honey sourced from Meliponula (Axestotrigona) ferruginea, a stingless bee species that is commonly managed in the African tropics. The findings reveal that stingless bee honey exhibits remarkable inhibitory effect against both resistant and susceptible bacterial strains. Notably, the studied honey samples retained a substantial portion of their antibacterial potency (89.9 - 98.7%) after the removal of hydrogen peroxide. Interestingly, the antibacterial activity of honey did not correlate with its total phenolic and flavonoid content, suggesting the influence of specific bioactive compounds rather than the overall phytochemical content. Stingless bee honey was most effective against Gram-positive bacterial strains, particularly Staphylococcus aureus. These results underscore the therapeutic potential of stingless bee honey for the management of pathogenic bacteria, including resistant strains. Future investigations should focus on elucidating the specific bioactive compounds present in stingless bee honey to bolster its clinical applications.

Phylogrouping, Virulence Profile and Antibiogram of Escherichia coli Strains Associated with Canine Pyometra

Background: Multi-drug resistant bacterial strains with biofilm-forming ability are one of the significant reasons contributing to the failure of medical management and recurrence of canine pyometra. The predominant bacterial agent implicated in canine pyometra is Escherichia coli, the different strains of which can be grouped into distinct phylogroups with the same ecological niches, characteristics and tendency to cause disease. The identification of a phylogroup of an unknown strain can facilitate the control, prevention and treatment of infections. Methods: The isolates of E.coli obtained from 25 clinical cases of pyometra were identified based on the cultural, morphological and biochemical characteristics. The antibiogram of the isolates were done employing Kirby-Bauer disk diffusion method. Biofilm forming ability of theisolates were detected by tissue culture plate method and the presence of virulence genes among them were detected using a multiplex PCR. The phylogrouping of E. coli was done employing the novel quadruplex PCR method. Result: In the antibiogram, most isolates were found sensitive to Amoxycillin-clavulanate (90%), Gentamicin (80%),Tetracycline (50%) and Amikacin (50%), while 100% resistance were shown towards ceftazidime-clavulanate, enrofloxacin,ceftriaxone-tazobactam, ciprofloxacin and cefotaxime-clavulanate. Among the E. coli isolates, strong and moderate biofilm producers showed resistance to a wide range of antibiotics compared to non-biofilm producers. Around 80% of the isolates belonged to the phylogroup B2 and all of these had the presence of fimH, sfa, and csgA genes. Among the isolates belonged to the phylogroup B2, 87.5% of the isolates had pap gene while none of them possessed afa gene.

Analysis of the Antibiotic-Potentiating Activity, Absorption, Distribution, Metabolism, and Excretion (ADME) and the Molecular Docking Properties of Phytol Against Multi-Drug-Resistant (MDR) Strains.

Background: Phytol is a diterpene from the long-chain unsaturated acyclic alcohols, known for its diverse biological effects, including antimicrobial and anti-inflammatory activities. Present in essential oils, phytol is a promising candidate for various applications in the pharmaceutical and biotechnological sectors. This study aimed to evaluate the in vitro antibacterial and drug-potentiating effects of phytol against multidrug-resistant bacteria and to evaluate its in silico properties: ADME and molecular docking. Methods: The in vitro antibacterial activity of phytol and the phytol combined with conventional drugs was evaluated by microdilution tests against standard and resistant bacterial strains. Finally, the SwissADME platform was employed to analyse the physicochemical and pharmacokinetic characteristics of phytol. Results: Phytol significantly reduced the Minimum Inhibitory Concentration (MIC) of norfloxacin and gentamicin required to inhibit multidrug-resistant strains of Escherichia coli and Staphylococcus aureus, respectively. Additionally, ADME analysis revealed that phytol exhibits low toxicity and favourable pharmacokinetic properties; in addition, it is revealed through molecular docking that phytol showed a relevant affinity with the proteins 6GJ1 and 5KDR, however, with values lower than the drugs gentamicin and ampicillin. Conclusions: Collectively, these findings suggest that phytol holds potential as an effective adjuvant in combating antimicrobial resistance.

Phytochemical screening of multiple Turmeric (Curcuma longa L.) extracts against multidrug resistant bacteria

Turmeric, a naturally occurring kitchen spice, possesses a wide range of medicinal properties. It has been reported to exhibit analgesic, anti-inflammatory, anti-bacterial, antifungal, antioxidant and wound healing properties. Yet, a detailed investigation is required for its screening against clinical isolates of multidrug resistant bacteria, so that it could be used as, cost effective, indigenous and readily available kitchen spice in crude form for the treatment of these bacterial infections at home. In current study, three fractions of ethyl acetate extracts of turmeric were screened against four multidrug resistant bacterial strains. Disc diffusion method was used to perform antibacterial activity and by calculation the Minimum Inhibitory Concentration (MIC). It was confirmed that all bacterial strains were highly sensitive towards all turmeric fractions. GCMS analysis of various fractions exhibited the presence of various flavonoids and polyphenols, their presence was further ascertained by chemical tests. It has been proposed that the synergistic effect of curcumin as well phenolics, crude extracts of turmeric showed promising antibacterial potential against multidrug resistant bacteria.Turmeric, a naturally occurring kitchen spice, possesses a wide range of medicinal properties. It has been reported to exhibit analgesic, anti-inflammatory, anti-bacterial, antifungal, antioxidant and wound healing properties. Yet, a detailed investigation is required for its screening against clinical isolates of multidrug resistant bacteria, so that it could be used as, cost effective, indigenous and readily available kitchen spice in crude form for the treatment of these bacterial infections at home. In current study, three fractions of ethyl acetate extracts of turmeric were screened against four multidrug resistant bacterial strains. Disc diffusion method was used to perform antibacterial activity and by calculation the Minimum Inhibitory Concentration (MIC). It was confirmed that all bacterial strains were highly sensitive towards all turmeric fractions. GCMS analysis of various fractions exhibited the presence of various flavonoids and polyphenols, their presence was further ascertained by chemical tests. It has been proposed that the synergistic effect of curcumin as well phenolics, crude extracts of turmeric showed promising antibacterial potential against multidrug resistant bacteria.

Antimicrobial risk assessment-Aggregating aquatic chemical and resistome emissions.

Urban water systems receive and emit antimicrobial chemicals, resistant bacterial strains, and resistance genes (ARGs), thus representing "antimicrobial hotspots". Currently, regional environmental risk assessment (ERA) is carried out using drug consumption data and threshold concentrations derived based on chemical-specific minimum inhibitory concentration values. A legislative proposal by the European Commission released in 2022 addresses the need to include selected ARGs besides the chemical concentration-based ERAs. The questions arise as to (A) how to improve chemical concentration-based risk assessment and (B) how to integrate resistome-related information with chemical-based risk - the main focal areas of this study. A tiered chemical risk prediction method is proposed by considering effluents of sewer networks and water resource recovery facilities (WRRFs). To improve predicted environmental concentrations (PEC in recipient water bodies), the impact of antimicrobial bio- and re-transformation in WRRFs is assessed using reliable global data. To combine chemical and genetic risks, a new parameter, i.e., the gene response efficiency (GRE) is proposed. A regression analysis show four orders of magnitude differences in GRE values amongst the seven antimicrobial classes studied. Higher GRE values in wastewater are obtained for antimicrobials with relatively low consumption rate levels.

Green Synthesis and Characterization of Silver Nanoparticles Using Zingiber officinale Extracts to Investigate Their Antibacterial Potential.

Antimicrobial resistance (AMR) has emerged as a significant global concern. To combat this growing threat, various strategies have been employed, including the use of plant extracts and the biosynthesis of nanoparticles (NPs). The current study was designed to evaluate the phytochemical analysis of ginger (Zingiber officinale) extracts, characterize the silver nanoparticles (AgNPs) and to see their antibacterial potentials against multi-drug resistant (MDR) bacterial strains. The extracts were prepared and initially assessed for their phytochemical composition and antibacterial activity. Then, AgNPs were synthesized from these extracts at room temperature, and various analytical techniques, including UV-visible spectroscopy, X-ray diffraction (XRD), ATIR-FTIR, zeta sizer, scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDXA), were used to characterize the NPs. After confirmation of prepared NPs, they were subjected to their antibacterial activity. HPLC analysis demonstrated the presence of eight phytoconstituents in organic ginger extracts. The absorption spectra of the silver suspension exhibited surface plasmon resonance peaks with maxima between 420 and 448 nm. Functional groups like C-H, N-H, OH, C-O-C, C=O, and C-O were identified in both the organic and aqueous extracts of Z. officinale, playing a key role in the formation of AgNPs, as characterized by ATR-FTIR analysis. Both ginger organic and aqueous extract synthesized AgNPs crystalline structure was shown in XRD analysis and the particle size distribution showed average diameter of 200.5 nm of AgNPs from aqueous extracts. Scanning Electron Microscopy displayed spherical structure and EDA results showed the percentage of elements in synthesized AgNPs using plant extracts. Most promising antibacterial activity was obtained against Escherichia coli ie 20.83±0.53 for 100µg/mL. The results of the current study showed that AgNPs synthesized from different ginger extracts have promising antibacterial properties and can be potential candidates for alternative treatment options for bacterial infections.

Assessing Bacteriological Profiles and Targeting Resistant Bacterial Superbugs to Develop an Antibiogram Aiding in Antibiotic Selection.

Introduction The success of surgical procedures is becoming more threatened by the advent of multi-drug resistant (MDR) bacterial strains, sometimes known as superbugs. These resistant microorganisms frequently cause post-surgical infections, which raise morbidity, death, and medical expenses. With an emphasis on resistant strains, this seeks to create an antibiogram and a thorough microbiological profile of surgical infections in order to help choose the most effective antimicrobial therapy. The outcomes will lessen the effects of resistant microbial superbugs in surgical settings, optimize the use of antibiotics in turn, and improve infection control techniques. Objectives To identify and isolate the bacterial microbes that trigger post-surgical infections in patients. To determine the antibiotic resistance profiles of these bacterial isolates. To construct a local antibiogram for post-surgical infections, aiding in the appropriate selection of antibiotics. Method A prospective cross-sectional study was carried out in Government General Hospital, Nellore. Based on the sample size, 738 patients were taken. Patients were recruited based on eligibility criteria. A questionnaire was prepared, and details were collected. Gram-staining techniques were used to identify organisms. Biochemical tests were done to confirm the bacteria. Culture sensitivity tests were carried out by disk diffusion method to know the zone of inhibition. A structured antibiogram was developed. Results Of the 738 patients, 324 were found to have Surgical Site Infections (SSI). One-hundredand seventy two females were prone to SSI, which is a high number. Three-hudred and thirty eight organisms were identified among 324 SSI patients, mostly comprised of staphylococcus (28.6%) followed by Escherichia coli (E.coli) (21.3%). The gynecology department comprises more SSI followed by surgical (31.7%). Cephalosporins are commonly used antibiotics before and after surgery. It is found to be resistant to most organisms, whereas Gentamicin is found to be sensitive. Discussion It was evident that the more contaminated the wounds being operated on, the higher the SSI. Compared to scheduled elective surgeries, the infection rate for emergency procedures was nearly twice as high. There was no bacterial growth in 404 patients out of 738. Conclusion This study emphasizes the increasing difficulty in treating surgical infections caused by antibiotic-resistant organisms and the urgent need for accurate, data-driven methods of infection management. It is advised to employ an antibiogram to reduce the spread of resistant organisms because a significant percentage of samples are resistant to the most commonly used medications. National surveillance of microbes resistant to antibiotics must be established.

Nature-Inspired Antimicrobial Agents: Cinnamon-Derived Copper Oxide Nanoparticles for Effective Aspergillus Niger Control.

The emergence of resistant bacterial and fungal strains poses significant challenges in various industrial processes including food, medicines, and leather industry. It necessitates the development of novel and effective antimicrobial agents. In the present work, we have developed an ecofriendly and sustainable approach to synthesize silver-doped copper oxide nanoparticles by using cinnamon bark extract (C-CuO/Ag). The nanoparticles were characterized via UV-visible spectroscopy at 190-800 nm, FT-IR, SEM-EDAX, XRD, and further subjected to determine antimicrobial potential, minimum inhibitory concentration (MIC), and anti-biofilm potential against both bacterial and fungal species. UV-visible spectrum showed maximum absorption at 210 nm in ultraviolet range and 419 nm in visible range. Various strong and weak peaks were obtained in FT-IR spectra, which defined the presence of corresponding functional groups in C-CuO/Ag nanoparticles. SEM analysis revealed the tightly packed confirmation, while EDS confirmed the elemental analysis of C-CuO/Ag nanoparticles. XRD spectrum of C-CuO/Ag nanoparticles showed strong diffraction peaks at 2Ө of 31.92˚, 35.67˚, and 48.51˚, which confined with the plane indices of (-110), (111), and (-202), respectively, while weak diffraction peaks at 2Ө of 56.31˚, 58.9˚, and 77.4˚, which leads to the crystal planes of (202), (-220), and (311), respectively. Antimicrobial assays showed clear zones of inhibition against microbial strains as maximum inhibition diameter was observed against Aspergillus niger (31.5 ± 0.7 mm) followed by Escherichia coli (30.1 ± 0.3 mm) and Staphylococcus aureus (29.5 ± 0.7 mm). These findings provide support clear evidence that CuO nanoparticles can serve as potent antibacterial and antifungal compounds against highly resistive and pathogenic microbial strains.

Exploring the Efficacy of pH-Responsive Vancomycin/Ag/ZIF-8 Nanoparticles Modified with Hyaluronic Acid for Enhanced Antibacterial Therapy and Wound Healing.

This study introduces a novel type of metal-organic framework material, specifically zeolitic imidazolate framework-8 (ZIF-8), that is integrated with silver nanoparticles and further enhanced by incorporating vancomycin (Van) to create a composite named as Van/Ag/ZIF-8. This composite demonstrates a potent and smart antimicrobial effect due to its ability for releasing silver ions and Van in a controlled manner, especially in the microacidic conditions surrounding bacterial cells. Furthermore, we used hyaluronic acid to modify Van/Ag/ZIF-8, resulting in a composite denoted as Van/Ag/ZIF-8@HA. This composite exhibits a significant inhibition effect against the proliferation of both Gram-negative (Escherichia coli 100%) and Gram-positive (Staphylococcus aureus 99.9%) resistant bacterial strains while exerting no adverse effects on animal cellular growth. These findings underscore its favorable biocompatibility profile. The experimental results show a combined antibacterial action against prevalent bacterial infections, which is supported by in vivo experiments using a skin wound model. This work confirms the composite's significant role in fighting pathogenic infections and aiding in healing skin wounds. The innovative strategy not only tackles the pressing issue of antibiotic-resistant bacterial infections but also marks a significant advancement in the areas of wound healing and medical research, offering a promising path for future investigations and therapeutic uses.

Physicochemical properties, GC–MS profiling, and antibacterial potential of Allium sativum essential oil: In vitro and in silico approaches

Antibiotic resistance remains a critical challenge for public health. In this study, we investigate the antibacterial potential of Moroccan Allium sativum L. essential oil (EO) through both in vitro and in silico approaches. The EO was extracted using hydrodistillation, and its physicochemical properties were analyzed alongside its chemical composition via gas chromatography-mass spectrometry (GC/MS). We assessed antibacterial efficacy through disk diffusion assays targeting Escherichia coli (E. coli), methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa (P. aeruginosa), and determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Finally, an in silico molecular docking analysis and ADMET (absorption, distribution, metabolism, excretion, and toxicity) prediction were performed. Our analysis identified 13 sulfur-based compounds within the EO, with diallyl disulfide (42.85 %), methylallyl disulfide (18.84 %), methylallyl trisulfide (15.38 %), and diallyl trisulfide (13.11 %) as major constituents. The EO demonstrated robust activity against MRSA, with an inhibition zone of 22 mm and an MIC of 0.75 mg/mL, whereas E. coli exhibited lower sensitivity, with an MIC of 1.51 mg/mL. Molecular docking analysis suggested that the primary sulfur compounds may effectively inhibit bacterial resistance-related enzymes. These findings highlight the potential of Allium sativum L. EO as a natural antibacterial agent, attributed largely to its sulfur compound content. This activity is likely linked with the EO's interaction with the complex structures of bacterial cell membranes, offering promise in combating resistant bacterial strains.

Metagenomics insights into bacterial diversity and antibiotic resistome of the sewage in the city of Belém, Pará, Brazil.

The advancement of antimicrobial resistance is a significant public health issue today. With the spread of resistant bacterial strains in water resources, especially in urban sewage, metagenomic studies enable the investigation of the microbial composition and resistance genes present in these locations. This study characterized the bacterial community and antibiotic resistance genes in a sewage system that receives effluents from various sources through metagenomics. One liter of surface water was collected at four points of a sewage channel, and after filtration, the total DNA was extracted and then sequenced on an NGS platform (Illumina® NextSeq). The sequenced data were trimmed, and the microbiome was predicted using the Kraken software, while the resistome was analyzed on the CARD webserver. All ecological and statistical analyses were performed using the. RStudio tool. The complete metagenome results showed a community with high diversity at the beginning and more restricted diversity at the end of the sampling, with a predominance of the phyla Bacteroidetes, Actinobacteria, Firmicutes, and Proteobacteria. Most species were considered pathogenic, with an emphasis on those belonging to the Enterobacteriaceae family. It was possible to identify bacterial groups of different threat levels to human health according to a report by the U.S. Centers for Disease Control and Prevention. The resistome analysis predominantly revealed genes that confer resistance to multiple drugs, followed by aminoglycosides and macrolides, with efflux pumps and drug inactivation being the most prevalent resistance mechanisms. This work was pioneering in characterizing resistance in a sanitary environment in the Amazon region and reinforces that sanitation measures for urban sewage are necessary to prevent the advancement of antibiotic resistance and the contamination of water resources, as evidenced by the process of eutrophication.

Niche-specific metabolic phenotypes can be used to identify antimicrobial targets in pathogens.

Bacterial pathogens pose a major risk to human health, leading to tens of millions of deaths annually and significant global economic losses. While bacterial infections are typically treated with antibiotic regimens, there has been a rapid emergence of antimicrobial resistant (AMR) bacterial strains due to antibiotic overuse. Because of this, treatment of infections with traditional antimicrobials has become increasingly difficult, necessitating the development of innovative approaches for deeply understanding pathogen function. To combat issues presented by broad- spectrum antibiotics, the idea of narrow-spectrum antibiotics has been previously proposed and explored. Rather than interrupting universal bacterial cellular processes, narrow-spectrum antibiotics work by targeting specific functions or essential genes in certain species or subgroups of bacteria. Here, we generate a collection of genome-scale metabolic network reconstructions (GENREs) of pathogens through an automated computational pipeline. We used these GENREs to identify subgroups of pathogens that share unique metabolic phenotypes and determined that pathogen physiological niche plays a role in the development of unique metabolic function. For example, we identified several unique metabolic phenotypes specific to stomach pathogens. We identified essential genes unique to stomach pathogens in silico and a corresponding inhibitory compound for a uniquely essential gene. We then validated our in silico predictions with an in vitro microbial growth assay. We demonstrated that the inhibition of a uniquely essential gene, thyX, inhibited growth of stomach-specific pathogens exclusively, indicating possible physiological location-specific targeting. This pioneering computational approach could lead to the identification of unique metabolic signatures to inform future targeted, physiological location-specific, antimicrobial therapies, reducing the need for broad-spectrum antibiotics.

Resistance tofluoroquinolones among Klebsiella pneumoniae isolates collected from patients referred to the teaching hospitals of Ardabil university of medical sciences in 2020

Background. Klebsiella pneumoniae (KP) is one of the most important causes of hospital-acquired infection and one of the most important causes of ventilator-associated pneumonia. During the present study, we investigated the resistance to fluoroquinolones among KP isolates collected from patients referred to hospitals affiliated with Ardabil University of Medical Sciences in 2020. Methods. In this descriptive, cross-sectional study, the minimum inhibitory concentration (MIC) of ciprofloxacin (CLX) was determined by the agar dilution method, and mutations in the gyrA and parC genes and the presence of resistance genes, such as accA, qnr, and qepA, were evaluated using the polymerase chain reaction method. Results. Out of 100 isolates, 43% (n = 43) were resistant to CLX. The MIC range of CLX was 0.5 µg/mL to 1024 µg/mL. Isolates with a high MIC of CLX were investigated for mutations in the gyrA and parC genes. In the investigation of mutations in gyrA, a substitution from serine to isoleucine was observed at position 83, while no mutation was found in parC. In 10 isolates (10%), the presence of the aac (6')-Ib-cr gene was detected, while qepA and qnr resistance genes were not observed in any of the isolates. Conclusion. Based on the findings, a high frequency of the aac (6')-Ib-cr gene was reported in this study. Since this gene is located on a plasmid, it can be easily transferred between KP strains in a hospital setting and leads to the spread of resistance to fluoroquinolones. Practical Implications. The emergence of bacterial resistant strains is on the rise and has become a serious public health problem worldwide. Infection with these strains leads to complicated diseases with worse outcomes, prolonged hospitalization, increased healthcare costs, an increased need to use second-line drugs with costs, and treatment failures.

Extended-spectrum β - lactamase inhibitory potential of Dichrocephala integrifolia: an in vitro and computational studies

Extended-spectrum β-lactamases (ESBL) producing enterobacteriales are a major global health concern since they often result in the ineffectiveness of empirical antibiotic therapy with β-lactams. This study aims to identify potential medicinal plants that can inhibit β-lactamase and subsequently enhance the activity of the β-lactams against resistant bacterial strains. A synergistic study of Dichrocephala integrifolia extract exhibited good synergistic activity against a CTX-M-producing organism, which was confirmed using an agar-based diffusion bioassay method. Further validation was done by Molecular docking in which, the phytocompound Propanamide, N-[4-(4-chlorophenyl)-2-thiazolyl]-3-(1-pyrrolidinyl)-/NSC339591, obtained from the GC-MS study showed a good binding affinity with favourable hydrogen bond interactions with the active sites of CTX-M-14. This phytocompound was further selected for a Molecular Dynamic Simulation (MD) study with CTX-M-14, where the complex exhibited good stability and maintained a consistent conformation throughout the simulation. NSC339591 cleared the drug-likeness filters.

Activated Charcoal-Alginate Platform for Simultaneous Local Delivery of Bioactive Agents: At the Nexus of Antimicrobial and Cytotoxic Activity of Zn2+ Ions.

Antimicrobial resistance (AMR) is a global public health threat that affects cancer patients more than the general population. In this work, a composite system based on Zn-alginate hydrogel and activated charcoal (AC) particles that, upon contact with physiological fluids, simultaneously releases bioactive agents (Zn2+ and AC particles impregnated with povidone-iodine) was designed to locally address specific problems characteristic for malignant wounds (MWs). This composite was comprehensively investigated in vitro regarding its morphology (field-emission scanning electron microscopy), Zn2+ release (flame atomic absorption spectrometry), iodine adsorption and desorption from AC particles (energy dispersive X-ray analysis and UV-visible spectroscopy) as well as its antimicrobial and antitumor activity. With respect to the ongoing AMR crises, antimicrobial activity was tested against a wide range of wild multi-drug resistant bacterial and yeast strains, all isolated from patient wounds. Since Zn2+ ions proved to be selectors of resistant strains of bacteria, the synergistic activity of AC particles and adsorbed iodine was shown to be crucial for excellent antibacterial activity. On the other hand, the synergy of AC particles and Zn2+ ions showed an equally strong antifungal effect. In addition, antimicrobial concentrations of Zn2+ ions showed cytotoxic activity against two cancer cell lines derived from cancers affecting skin either as metastatic cancer (breast cancer MDA-MB-453 cell line) or primary cancer of the skin (malignant melanoma Fem-X cell line), which enables Zn2+ ions to be further investigated as potent local agents targeting malignant cells.

Plant Based Antimicrobials Against Multi Drug Resistant Bacterial Strains (MDRS)

Plant Based Antimicrobials Against Multi Drug Resistant Bacterial Strains (MDRS)