Enterobacter Aerogenes Research Articles

Mechanism of antimony oxidation and adsorption using immobilized Klebsiella aerogenes HC10 in soil

Klebsiella aerogenes HC10 is one of the few strains isolated from contaminated soil that efficiently oxidizes Sb. However, the sensitivity of microorganisms to environmental conditions limits Sb-oxidizing bacteria applications in soil remediation. Immobilizing Sb-oxidizing bacteria is a promising strategy to improve colonization rates and microorganism inefficiencies and to strengthen bioremediation in Sb-contaminated soil. This study evaluated the feasibility of an immobilization approach to enhance Sb oxidation and the remediation performance of strain HC10 in soil. The results indicated that a mixed matrix of polyvinyl alcohol and sodium alginate as fixed carriers provided a porous microstructural environment conducive to HC10 colonization and proliferation. Sb(III) concentration was reduced by 9.8 mg/L. The total Sb decreased by 3.8 mg/L by immobilized HC10 after 7 d. Key metabolites involved in Sb oxidation and adsorption were significantly upregulated. In soil, immobilized HC10 removed 48.68 % and 61.74 % of water-extractable and citric acid-extractable Sb(III), respectively. Some well-crystallized (hydr)oxide Sb fractions binding to the mineral surface were transformed into the mineral lattice form, creating an inner-sphere complex that effectively immobilized Sb. Immobilized HC10 enhanced hydrogen peroxidase, urease, and sucrase activities related to soil antioxidants and nutrient cycling. Immobilized HC10 promoted the proliferation of indigenous bacteria, which emerged as the dominant bacterial community with the potential for Sb oxidation. The ars operon genes associated with Sb resistance and transport were significantly expressed in HC10 treatments, providing a crucial basis for colonization in the soil. These results highlight the potential of immobilized Sb-oxidizing bacteria for enhanced bioremediation of Sb-contaminated soil.

Microbial Bioremediation of Spent Engine Oil: Current Advances, Challenges, and Future Directions

Study’s Excerpt Recent advancements in microbial bioremediation of spent engine oil (SEO) are presented. Specifically, the efficiency of bacterial and fungal species in degrading SEO hydrocarbons are reviewed. Key factors that influence degradation rates, such as strain specificity and environmental parameters in relation to different microorganisms are also highlighted. Full Abstract The extensive pollution of soil and water by spent engine oil (SEO) presents a considerable environmental hazard, especially because of its poisonous and recalcitrant characteristics. Traditional remediation approaches typically fall short in managing these toxins successfully, leading to an increased interest in bioremediation as a sustainable option. This review aims to compile current achievements/advancements in the microbial bioremediation of SEO, with emphasis on the effectiveness of several bacterial and fungal species in degrading the hydrocarbons in SEO under diverse environmental settings. Various studies published in the last decade (accessible via Google Scholar, Google, Scopus, and PubMed), reporting on microbial degradation rates on SEO, the impact of environmental conditions, and the efficacy of microbial consortia were objectively selected and analysed. Key findings showed that various genera such as Alcaligenes, Acinetobacter, Bacillus, Candida, Flavobacterium, Pseudomonas, and Rhodococcus were the most commonly reported microorganisms with potential SEO remediation because they have been reported to significantly degrade and used hydrocarbons in SEO as an energy source. Notably, Pseudomonas alcaligenes and Klebsiella aerogenes exhibited significant degradation rates of SEO, up to 68%, over 21 days under optimal conditions; Acinetobacter, Bacillus, Micrococcus, Flavobacterium, and Pseudomonas were found to exhibit a total hydrocarbon reduction of 86.7% over 60 days; while species like Ochrobactrum thiophenivorans were found to effectively degrade waste lubricating oil. However, there are significant differences in degradation rates among the reported species due to physiological factors such as temperature, pH, and available nutrients. Hence, it is inferential to conclude that microbial bioremediation shows promise in SEO management but its effectiveness is highly dependent on the type of microbial strain used and optimizing environmental conditions. Therefore, this review identifies several key knowledge gaps and proposed future research directions, such as the integration of bioremediation with emerging technologies to improve and ensure efficiency and scalability in real-world applications.

The respiratory chain of Klebsiella aerogenes in urine-like conditions: critical roles of NDH-2 and bd-terminal oxidases

Klebsiella aerogenes is an opportunistic nosocomial bacterial pathogen that commonly causes urinary tract infections. Over the past decades, K. aerogenes strains have acquired resistance to common antibiotics that has led to the rise of multidrug-resistant and even pandrug-resistant strains. Infections produced by these strains are nearly impossible to treat, which makes K. aerogenes a global priority to develop new antibiotics and there is an urgent need to identify targets to treat infections against this pathogen. However, very little is known about the metabolism and metabolic adaptations of this bacterium in infection sites. In this work, we investigated the respiratory metabolism of K. aerogenes in conditions that resemble human urine, allowing us to identify novel targets for antibiotic development. Here we describe that, unlike other gram-negative pathogens, K. aerogenes utilizes the type-2 NADH dehydrogenase (NDH-2) as the main entry point for electrons in the respiratory chain in all growth conditions evaluated. Additionally, in urine-like media, the aerobic metabolism as a whole is upregulated, with significant increases in succinate and lactate dehydrogenase activity. Moreover, our data show that the bd-I type oxidoreductases are the main terminal oxidases of this microorganism. Our findings support an initial identification of NDH-2 and bd-I oxidase as attractive targets for the development of new drugs against K. aerogenes as they are not found in human hosts.

In vivo emergence of resistance to ceftazidime/avibactam through modification of chromosomal AmpC β-lactamase in Klebsiella aerogenes.

We describe the in vivo emergence of resistance to ceftazidime/avibactam via modification of AmpC in a clinical Klebsiella aerogenes isolate during therapy with this combination. Paired ceftazidime/avibactam-susceptible/resistant isolates were obtained before and during ceftazidime/avibactam treatment. Whole genome sequencing revealed a differential mutation in AmpC (R148W) in the ceftazidime/avibactam-resistant isolate. Molecular cloning and structural studies confirmed the impact of this substitution, which affects the architecture of the H10 helix, on the evolved resistant phenotype.

Biodegradation of Deep Eutectic Solvent Pre-Treated Natural Rubber Gloves by Klebsiella aerogenes: A Sustainable Approach to Rubber Waste Management

This study investigates the potential of deep eutectic solvents (DES) to enhance the biodegradation of natural rubber gloves (NRG) by Klebsiella aerogenes. Choline chloride and urea (ChCl: urea) DES was employed to pre-treat NRG at various temperatures (80°C to 140°C) and durations (0.5h to 5h). Pre-treated rubber (p-NRG) underwent significant physical and chemical changes, enhancing its biodegradability. Analytical techniques such as dry weight analysis, bacteria cell concentration, FTIR TGA, and SEM were used to characterize the pre-treated and biodegraded samples. The results have demonstrated a significant weight loss and structural modifications in p-NRG, with the highest degradation efficiency of 43% observed at 140°C for 5hours of pretreatment before biodegradation. Meanwhile, merely 17% of biodegradation was observed in biodegradation without pre-treatment. DES pre-treatment notably enhanced NRG biodegradability, achieving a 50.6% weight loss at pH 7 and 35°C. The highest cell concentration, 0.75g/L, was recorded in the second week of the biodegradation process. Results has indicated that the maximum protein concentration of 697.3µg/mL, along with the highest enzyme activities for laccase and manganese peroxidase (MnP) at 0.46 ± 0.05 IU and 0.30 ± 0.05 IU respectively, were recorded at the second week of the biodegradation process. DES pre-treatment has significantly improved the biodegradability of NRG by Klebsiella aerogenes, offering a promising and eco-friendly solution for rubber waste management.

Antibacterial Potential and Phytochemical Analysis of Two Ethnomedicinally Important Plants

Medicinal plants exhibited great role in drug industries. Herbal medicines and their derivative products are often prepared from crude plant extracts. Echinops echinatus and Tridax procumbens both are belonging to Asteraceae family and these plants are ethnomedicinally important due to their utilization as traditional medicine to cure various diseases. Aim of the current study is to evaluate the antimicrobial properties, preliminary phytochemical and GC-MS analysis of these ethnomedicinally important plants to identify the compounds which are responsible for antimicrobial properties. Their extracts exhibited antimicrobial activity against Enterobacter aerogenes, Escherichia coli, Agrobacterium tumefaciens, Staphylococcus aureus, Bacillus subtilis, Pseudomonas syringae and Pseudomonas putida. Both plants contain the active principles like flavonoids, alkaloids, glycosides, saponins, terpenoids and tannins. Result of GC-MS analysis showed the presence of many compounds such as n-Hexadecanoic acid, Hexadecanoic Acid, Methyl ester, Octadecanoic acid, Stigmasterol, Naphthalene, Squalene, 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-, Squalene, 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-,5 Hydroxymethylfurfural, Lupeol, Dodecanoic acid, Vitamin E (α-Tocopherol), Neophytadiene, Phytol and many other compounds. These compounds are responsible for antimicrobial, anticancer and medicinal properties.

The Impact of Beneficial Microorganisms on Soil Vitality: A Review

The paper summarizes the literature on the critical impact of beneficial microorganisms on soil vitality. Common soil microorganisms, including bacteria, fungi, algae, protozoa, and viruses contribute significantly to enhancing soil fertility through processes such as nitrogen fixation, phosphorus solubilization and mobilization, sulfur cycle, composting, and heavy metal remediation. Their abundance and biomass vary significantly across taxa within the uppermost 15 cm of soil, with bacteria dominating numerically and fungi contributing substantially to biomass. These microorganisms mediate essential biogeochemical cycles in soil, including carbon, nitrogen, and phosphorus cycles, by facilitating the decomposition of organic matter and recycling soil nutrients. Nitrogen-fixing bacteria like Rhizobium are prevalent symbionts capable of biologically fixing nitrogen. Additionally, bacteria such as Micrococcus spp., Enterobacter aerogens, Pseudomonas capacia, fungi including Aspergillus niger, A. flavus, A. japonicas, Penicillum spp., and actinomycetes like Streptomyces play crucial roles in phosphorus solubilization, making phosphorus available for plant uptake. This synthesis underscores the critical role of beneficial microorganisms in maintaining soil vitality. These organisms interact with plants through beneficial relationships, influencing soil fertility dynamics by enhancing nutrient availability, promoting plant growth, and controlling pathogens. The use of biofertilizers has emerged as a sustainable strategy to improve crop yields and restore soil fertility, reducing environmental impacts linked to chemical fertilizers. Understanding the intricate dynamics of soil-beneficial microorganism and their interactions with Plants are pivotal for optimizing agricultural practices, ensuring long-term soil health, and enhancing productivity in sustainable farming systems.

Assessment of Nitrate Reduction by Microbes in Artificial Groundwater Medium

There are significant reasons for nitrate contamination in groundwater (Delhi, India): sewage, runoff from landfill sites, nitrogenous chemical fertilisers, and pesticides from agricultural lands. The highest recorded concentration of nitrate in Delhi’s groundwater is reported to be 1500 mg/l. Consumption of high nitrate through water may pose serious health problems in humans, especially children (below five years). The study’s primary objective was to isolate and identify nitrate-remediating microbes from the nitrate-contaminated site Okhla Barrage, located on the Yamuna River in Delhi, India. A total of 11 different strains were isolated from this site. Among these four strains exhibited 40%–50% remediation efficiency at a nitrate concentration of 1000 mg/l. Molecular characterisation revealed that these four strains, Enterobacter aerogenes, E. coli K12, <i>Klebsiella oxytoca</i> and <i>Lelliottia amnigena</i>, belong to the Enterobacteriaceae family. This study assessed the nitrate remediation potential of isolated microbes in groundwater with 1000 and 1500 mg/l nitrate concentrations. By using a 2% inoculum, the microbes were incubated anaerobically at room temperature for ten days. Nitrate concentrations were monitored every 48 hours. <i>Lelliottia</i>, <i>E. coli</i>, and <i>Enterobacter</i> reduced nitrate (1500 mg/l) by approximately 42%, 24%, and 29%, respectively, while <i>K. oxytoca</i> showed minimal reduction. <i>L. amnigena</i> exhibited superior nitrate removal efficiency compared to other strains. According to the reported data, these strains are known to reduce nitrate concentrations of 620 mg/l. However, our findings demonstrate a remarkable nitrate remediation capacity of 1500 mg/l, showcasing a novel contribution to this study. Further detailed analysis for condition optimisation and association of microbe-microbe could be more helpful.

Microorganism microneedle micro-engine depth drug delivery

As a transdermal drug delivery method, microneedles offer minimal invasiveness, painlessness, and precise in-situ treatment. However, current microneedles rely on passive diffusion, leading to uncontrollable drug penetration. To overcome this, we developed a pneumatic microneedle patch that uses live Enterobacter aerogenes as microengines to actively control drug delivery. These microbes generate gas, driving drugs into deeper tissues, with adjustable glucose concentration allowing precise control over the process. Our results showed that this microorganism-powered system increases drug delivery depth by over 200%, reaching up to 1000 μm below the skin. In a psoriasis animal model, the technology effectively delivered calcitriol into subcutaneous tissues, offering rapid symptom relief. This innovation addresses the limitations of conventional microneedles, enhancing drug efficiency, transdermal permeability, and introducing a creative paradigm for on-demand controlled drug delivery.

Emergence of blaOXA-181-bearing tigecycline-resistant Klebsiella aerogenes in China.

We report the isolation of a blaOXA-181-positive, tigecycline-resistant Klebsiella aerogenes strain KA04 from a Chinese inpatient's fecal sample. Species identification was performed using MALDI-TOF MS. The antibiotic susceptibilities were assessed via the broth microdilution method. To elucidate the transmission and genetic structure of the blaOXA-181 gene, conjugation assays and whole-genome sequencing (WGS) were performed. KA04 displayed resistance to carbapenems, quinolones, piperacillin/tazobactam and tigecycline. Through WGS and conjugation experiments, it was possible to confirm blaOXA-181 and qnrS1 genes causing antibiotic resistance were located on a 51-kb IncX3 type mobile plasmid, blaOXA-181 gene could be successfully transferred into E. coli EC600 at a conjugation frequency of 1.1 × 10- 4. tet(A) gene was located on both the chromosome and non-transmissible IncFIB(K) plasmid. This is a tigecycline-resistant K. aerogenes harboring blaOXA-181 isolate from human fecal sample, highlighting a significant public health concern. Further comprehensive surveillance is needed.

Surveillance on antimicrobial Resistance pattern of Third Generation Cephalosporins at the Benjamin Mkapa Tertiary Hospital in Tanzania

Abstract Background Antimicrobial resistance is a burden in Tanzania and the world economy, resulting in financial losses from lower production brought on by illness due to greater treatment expenses and death. Second- and third-line antibiotics like third generations of cephalosporins should be used rather than first-line, which is an expensive option, due to AMR. The direct effects of AMR include severe prolonged illnesses, prolonged hospital stays death, and (Global Action Plan on Antimicrobial Resistance., 2015) Methodology The retrospective study design was used to review AST to assess the AMR patterns from 2020-2022 for urine, pus, and blood samples as stated in the National Action Plan-Antimicrobial Resistance 2017. Results Three years (2020, 2021, and 2022) of antibiograms based on priority samples, priority pathogens and third generations of cephalosporins for both gram-negative and gram-positive bacteria see Tables 1 and 2. The surveillance identified sensitive (S), intermediate(I), and resistance(R) for tested bacteria. The N is the isolate number. Our antibiograms for third-generation cephalosporins were represented by cefotaxime, ceftazidime and ceftriaxone. The antimicrobial resistance to ceftriaxone for Acinetobacter species was 62.5% while 76% for Citrobacter. E. coli at 60.26%, Enterobacter aerogenes at 67.86%, Klebsiella species at 73.48% at 22.73%, Morganella morganii 65.75% and Staphylococcus aureus at 62.5%, Serratia marcescens 64.56%. Similar resistance trends have been observed in cefotaxime and ceftazidime. Conclusion Antimicrobial susceptibility surveillance, antimicrobial rotation and presentation of findings to clinicians for increased awareness and the promotion of a multi-disciplinary approach to successful AMS programmers is essential. Evidence found will optimize the use of antibiotics. Clinicians, pharmacists, and scientists will use obtained evidence in the development of guidelines and protocols for surgical prophylaxis, setting IPC programs, management of bacterial blood infections (septicemia and sepsis) and managing urinary tract infections by focusing on red flags antibiotics and bacteria such E. coli and K. pneumoniae. Avoiding delay of AST results by enough resources, and technology advancement. This enable identification of the causative pathogens facilitated the correct diagnosis, de-escalation, and use of targeted agents, which are necessary to promote the prudent use of antimicrobials. Antibiograms Table 1: Antibiogram of gram-negative bacteria Table 2: Antibiogram of gram-positive bacteria

Bacterial metabolites influence the autofluorescence of Clostridioides difficile.

Clostridioides difficile is a bacterial pathogen that has been implicated in severe gastrointestinal infections. C. difficile has intrinsic green autofluorescence and the level of this autofluorescence is known to be increased by growth time and oxygen. Currently, it is unclear if dietary compounds or metabolites from the gut microbiota are able to enhance C. difficile autofluorescence. Here, we aimed to determine potential factors that affect C. difficile autofluorescence. After screening a large repertoire of compounds, we identified several substances, like L-lysine and pantothenate, that led to an increased C. difficile autofluorescence. We also found that several members of the gut microbiota, such as Enterococcus faecalis, Klebsiella aerogenes and K. pneumoniae, can increase C. difficile autofluorescence through their secreted compounds. We further focused on the effect of K. pneumoniae on C. difficile autofluorescence and found that multiple enteric strains of K. pneumoniae could enhance C. difficile's autofluorescence. We used this enhanced autofluorescence to identify C. difficile in K. pneumoniae co-cultures by flow cytometry. Our findings shed light on the relationship between C. difficile and other members of the gut microbiota, as well as different factors that can affect C. difficile autofluorescence.

Pomegranate peel mediated silver nanoparticles: antimicrobial action against crop pathogens, antioxidant potential and cytotoxicity assay

Biologically produced silver nanoparticles are becoming a more appealing option than chemically produced antioxidants and antimicrobial agents, because they are safer, easier to manufacture and have medicinal properties at lower concentrations. In this work, we employed the aqueous pomegranate peel extract (PPE) to synthesize silver nanoparticles (PPE-AgNPs), as peel extract is a rich source of phytochemicals which functions as reducing agent for the synthesis of PPE-AgNPs. Additionally, the PPE was examined quantitatively for total phenolics and total flavonoids content. PPE-AgNPs were characterized using analytical techniques including UV–Vis spectroscopy, DLS, FTIR, XRD, HRTEM and FESEM, evaluated in vitro against the plant pathogenic microbes and also for antioxidant activities. Analytical techniques (HRTEM and FESEM) confirmed the spherical shape and XRD technique revealed the crystalline nature of synthesized PPE-AgNPs. Quantitative analysis revealed the presence of total phenolics (269.93 ± 1.01 mg GAE/g) and total flavonoids (119.70 ± 0.83 mg CE/g). Biosynthesized PPE-AgNPs exhibited significant antibacterial activity against Klebsiella aerogenes and Xanthomonas axonopodis, antifungal activity against Colletotrichum graminicola and Colletotrichum gloesporioides at 50 µg/mL concentration. The antioxidant potential of biosynthesized PPE-AgNPs was analysed via ABTS (IC50 4.25 µg/mL), DPPH (IC50 5.22 µg/mL), total antioxidant (86.68 g AAE/mL at 10 µg/mL) and FRAP (1.93 mM Fe(II)/mL at 10 µg/mL) assays. Cytotoxicity of PPE-AgNPs was valuated using MTT assay and cell viability of 83.32% was determined at 100 µg/mL concentration. These investigations suggest that synthesized PPE-AgNPs might prove useful for agricultural and medicinal purposes in the future.

Utilization of water chestnut waste for biohydrogen production and enhanced power generation by stacked microbial fuel cell

A novel two-stage approach combining dark fermentation with microbial fuel cell (MFC) technology is proposed which enable biohydrogen production and bioelectricity generation from residual substrate energy. In the present study, batch fermentation of water chestnut waste using Enterobacter aerogenes (MTCC 2822) resulted in the production of biohydrogen. In the batch process, the highest production was 3.2 L/L. Further, single-parameter optimization and multi-parameter optimization were conducted via Response Surface Methodology (RSM) using the Central Composite Design (CCD) model. The maximum biohydrogen reached 3.44 g/L with 55% COD removal. The biohydrogen yield was 7.163 g H2/kg CODreduced with a maximum production rate of 712 mL/L/h. Further, the waste fermentation medium or spent media was used as a substrate in a Microbial Fuel Cell (MFC) to produce power using Pseudomonas aeruginosa PA1_NCHU as inoculum. MFCs were operated with various concentrations of phosphate buffer in the anolyte. As the output is limited in a single MFC, MFCs were operated in parallel stacks to increase power output. A maximum of 28% increase in the power density was observed in stacked MFCs. The energy recovered from the dark fermentation process was around 10.39% and a single MFC was around 10.67%. Hence, this study highlights the innovative use of agricultural waste and the effective combination of dark fermentation with stacked MFC, presenting a sustainable method of maximizing biohydrogen production and bioelectricity from spent media. By leveraging stacked MFC configuration, the potential of higher power output is demonstrated, underscoring the significance of this integrated system for energy recovery.

Dopaminergic neuronal regulation determines innate immunity of Caenorhabditis elegans during Klebsiella aerogenes infection

The innate immune signals are the front line of host defense against bacterial pathogens. Pathogen-induced harmful effects, such as reduced neuronal signals to the intestine, affect the host's food sensing and dwelling behavior. Here, we report that dopamine and kpc-1 signals control the intestinal innate immune responses through the p38/PMK-1 MAPK signaling pathway in C. elegans. K. aerogenes infection in C. elegans affects the food-dwelling behavior, which depends on dopamine regulation. The absence of the dopamine receptor (dop-1) and transporter (dat-1) increases attraction to the pathogen instead of avoidance. The K. aerogenes infection affects age-1 regulation through the furin-like proprotein convertase (kpc-1); the absence of kpc-1 affects environment-dependent dauer formation. In contrast, the dop-1 mutation antagonistically regulates intestinal immune regulation, while the kpc-1 mutation partially regulates the p38/PMK-1 MAPK pathway. Our findings indicate that dopamine and kpc-1signaling from the nervous system control intestinal immunity in an antagonistic and agonistic manner, respectively.

Investigation of in vitro susceptibility and resistance mechanisms to amikacin among diverse carbapenemase-producing Enterobacteriaceae

ObjectiveThis study aims to assess the in vitro drug susceptibility of various Carbapenemase-Producing Enterobacteriaceae (CPE) genotypes and elucidate the underlying mechanisms of amikacin resistance.MethodsA total of 72 unique CPE strains were collected from the Second Hospital of Jiaxing between 2019 and 2022, including 51 strains of Klebsiella pneumoniae, 11 strains of Escherichia coli, 6 strains of Enterobacter cloacae, 2 strains of Klebsiella aerogenes, 1 strain of Citrobacter freundii, and 1strain of Citrobacter werkmanii. Among these strains, 24 carried blaKPC gene, 20 carried blaNDM gene, 23 carried blaOXA−48−like gene, and 5 carried both blaKPC and blaNDM. We measured the in vitro activity of amikacin and other common antibiotics. Strains carrying blaOXA−48-like gene were selected for whole genome sequencing (WGS) via next-generation sequencing to identify genes related to antimicrobial resistance (AMR) and virulence factor (VF).ResultsOut of the 72 CPE strains tested, 41.7% exhibited resistance to amikacin. The drug resistance rates for K. pneumoniae, E. coli, and Enterobacter spp. were 51.0%, 27.3%, and 10.0%, respectively. The majority of the CPE strains (> 90%) displayed resistance to cephalosporins and carbapenems, while most of them were sensitive to polymyxin B and tigecycline (97.2% and 94.4%). The amikacin resistance rate was 100% for strains carrying blaOXA−48, 20.8% for those with blaKPC, 5.0% for those with blaNDM, and 20.0% for those with both blaKPC and blaNDM. These differences were statistically significant (P < 0.05). Through sequencing, we detected aminoglycoside resistance genes rmtF and aac(6’)-Ib, VF genes iucABCD and rmpA2 in OXA-48-producing multidrug resistance and highly virulent strains. These genes were located on a IncFIB- and IncHI1B-type plasmid, respectively. Both plasmids were highly homologous to the plasmid from OXA-232 strains in Zhejiang province and Shanghai province. Integration of these resistance genes into the IncFIB plasmid, facilitated by the IS6 and/or Tn3 transposons, resulted in OXA232-producing K. pneumoniae with amikacin resistance.ConclusionThis study identified significant amikacin resistance in CPE strains, particularly in those carrying the blaOXA−48 gene. Resistance genes rmtF and aac(6’)-Ib were identified on plasmids. These results highlight the need for careful monitoring of amikacin resistance.

In vitro Study of Biofilm Sensitivity of to the Enzyme Complex Included in Wobenzym

Background. Bacterial films are a marker of chronic recurrent infections. Biofilms on mucous membranes block the inflammatory response of the macroorganism, suppressing the activity of immunocytes, and thereby allow microorganisms to reach high concentrations. Currently, research is being conducted to find medications that can act on biofilms. Enzymes, especially their complexes, are substances that can destroy bacterial films. Objective. Еo determine in vitro the sensitivity of bacterial biofilms formed by vaginal microorganisms to the complex of enzymes included in Wobenzym. Materials and methods. The study included 72 clinical isolates of pure microorganism cultures isolated from the vaginal biotope: Gardnerella vaginalis (3), Enterococcus faecalis (9), Escherichia coli (18), Klebsiella pneumoniae (15), Klebsiella aerogenes (3), Lactobacillus crispatus (3), Streptococcus pyogenes (3), Acinetobacter baumanii (3), Staphylococcus aureus (3), Candida albicans (3), Enterococcus faecium (3), Streptococcus agalactiae (3), Lactobacillus acidophilus (3). Bacterial biofilm formation was determined in polystyrene flat-bottom plates using a modified method of Christensen et al. (1985). The tablet form of Wobenzym was used in the study. The tablet shell was washed with saline, the tablet itself was dissolved in 10 ml of 0.9% NaCl and used for in vitro studies. The result was determined using a reader on a spectrophotometer to determine the optical density (OD) of the formed biofilm. It was believed that the drug acted on the bacterial film, reducing the OD by more than three times. Results. An in vitro study revealed clinical isolates of bacteria that formed biofilms of varying severity. Of the 72 clinical bacterial isolates, 38 formed biofilms. A pronounced effect of the complex of enzymes included in Wobenzym on biofilms formed by microorganisms such as A. baumanii, S. aureus, G. vaginalis and E. faecalis was noted. Conclusion. Wobenzym has an effective destructive effect on biofilms formed by various microorganisms, including G. vaginalis, common causative agents of bacterial vaginosis, as well as staphylococci and enterococci, causative agents of aerobic (nonspecific) vaginitis. Conclusion. The drug Wobenzym has an effective destructive effect on biofilms formed by various microorganisms, including Gardnerella vaginalis, common causative agents of bacterial vaginosis, as well as staphylococci and enterococci, causative agents of aerobic (nonspecific vaginitis).

Assessment of Bryophyllum pinnatum mediated Ag and ZnO nanoparticles as efficient antimicrobial and cytotoxic agent.

Bryophyllum pinnatum is used to cure infections worldwide. Although the flavonoids of this plant are well known, it is still unknown how much of the plant's Ag and ZnO nanoparticles are beneficial. In the current research work, silver and zinc oxide nanoparticles were prepared using Bryophyllum pinnatum extract. The synthesized particles were characterized by UV-visible spectroscopy, SEM, EDS, XRD and FTIR. Synthesized particles were subjected to evaluation of their bactericidal and antifungal activity at various doses. Uv vis spectra at 400nm corresponding to AgNPs confirmed their synthesis. Strong peaks in the EDS spectra of Ag and ZnO indicate the purity of the sample. The scanning electron microscopic images of ZnONPs showed a size of about 60nm ± 3nm, which demonstrated the presence of triangular-shaped ZnO nanoparticles. Green synthesized nanoparticles showed bactericidal activity against both Gram-positive (Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Agrobacterium tumifaciens, Salmonella setubal, Enterobacter aerogenes) strains. AgNPs proved to be more effective against Gram-negative bacterial strains compared to Gram-positive owing to MIC values (10 ppm and 20 ppm respectively). Whereas, ZnONPs were found more effective against Gram-positive bacteria with lower MIC values (10 ppm) as compared to Gram-negative ones (20 ppm). Also, the synthesized nanoparticles exhibited moderate dose-dependent antifungal activity against tested fungal strains ranging from 10 to 70%. Cytotoxicity of nanoparticles was found significant using Brine shrimp's lethality assay with IC50 values of 4.09 ppm for AgNPs, 13.72 ppm for ZnONPs, and 24.83 ppm for plant extract. Conclusively, Ag and ZnO nanoparticles were more effective than plant extract and AgNPs had higher activities than those of ZnONPs. Further research is warranted to explore the precise mechanism of action and the potential applications of these nanoparticles in the medical field.

Green synthesized AgNPs of the Anchusa arvensis aqueous extract resulting in impressive protein kinase, antioxidant, antibacterial, and antifungal activities.

This study focused on analyzing the pharmacological activities of AgNPs synthesized from an aqueous plant extract of Anchusa arvensis. The effectiveness of AgNPs was evaluated for protein kinase inhibition, antioxidant, antibacterial, and antifungal activities. The AgNPs and plant were used to regulate the protein kinase activity using the liquid TSB and ISP4 medium protein kinase inhibition study demonstrated that nanoparticles exhibited a larger zone of inhibition (9.1 ± 0.8) compared to the plant extract (8.1 ± 0.6). The antioxidant activity was assessed using DPPH reagent, and the results indicated that AgNPs displayed potent free radical scavenging properties. In terms of antibacterial activity, AgNPs showed higher efficacy against Enterobacter aerogens (20.1 ± 0.9), Bordetella bronchiseptaca (19.1 ± 0.9), and Salmonella typhimurium (17.2 ± 0.8) at 4 mg/mL. The antifungal activity of AgNPs was prominent against Aspergillus fumagatus (14.1 ± 0.9), Mucor species (19.2 ± 0.8), and Fusarium solani (11.2 ± 0.8) at 20 mg/mL. These findings suggest that AgNPs possess multiple beneficial properties, including bactericidal/fungicidal effects, protein kinase inhibition, and potential free radical scavenging abilities. Therefore, AgNPs have potential applications in various fields, such as biomedicine and industry, due to their ability to counteract the harmful effects of free radicals.

Fortification of cotton fabrics with dithiocarbamate-metal complexes to prepare durable antimicrobial fabrics

In this study, a simple and practical method is reported to fortify cotton fabrics with dithiocarbamate (DTC-Ct), dithiocarbamate-Cu (Cu-Ct) and dithiocarbamate-Ni (Ni-Ct) complexes via impregnation process to prepare durable antimicrobial fabrics. FTIR analysis indicates the presence of characteristic peaks corresponding to cellulose functional groups in the fortified fabrics. SEM micrographs illustrate the transition from a closed-packed, smooth surface in untreated cotton to a rough texture enveloped with metal complexes in fortified fabrics. EDX images confirm successful impregnation, with prominent peaks due to C and O in the untreated cotton, while additional signals of S, Cu, and Ni were observed in the fortified samples. TEM images revealed irregular, spherical nanoparticles within fortified cotton, compared with the rough surface of untreated fabrics. The average size of the treated cotton fabric fell within the range of 2.20–7.32, 3.83–28.50, and 2.70–7.32 nm for DTC-Ct, Cu-Ct and Ni-Ct, respectively. Untreated cotton fabric exhibits no inherent antibacterial properties, whereas fortified cotton fabrics demonstrate enhanced antibacterial efficacy against strains including Salmonella typhi, Enterobacter aerogenes, Shigella dysenteriae, and Klebsiella pneumonia, with Ni-Ct-fortified cotton proving most effective. Furthermore, the durability of additive adhesion to cotton fabrics was evaluated through washing tests, revealing robust adherence even after multiple cycles, with sustained antimicrobial inhibition observed for up to five wash cycles.