Strains Of Pathogenic Bacteria Research Articles

Comparative evaluation of antimicrobial activity of spinel structured transition metal ferrites supported on reduced graphene oxide against pathogenic strains of bacteria and fungi.

One of the global challenges for living things is to provide pollution and harmful microbes-free environment. In this study, magnetically retrievable spinel-structured manganese zinc ferrite (Mn0.5Zn0.5Fe2O4) (MZF) was synthesized by a facile solvothermal method. Further, the MZF with different weight percentages (10wt%, 50wt%, and 80wt%) were supported on reduced graphene oxide (rGO). The phase purity and morphology of MZF and MZF/rGO nanocomposite were confirmed by X-ray diffraction technique and scanning electron microscopy, respectively. The Fourier transform infrared spectroscopy, Raman, UV-visible spectroscopy, and thermogravimetric analyses of the as-synthesized nanocomposites were examined for the detection of various chemical groups, band gap, and thermal properties, respectively. The MZF/rGO nanocomposite exhibited significant antibacterial and antifungal activity against Eggerthella lenta, Enterococcus faecalis, Klebsiella pneumonia, Pseudomonas aeruginosa, and Candida albicans compared to bare MZF and rGO. The high surface area of rGO plays a crucible role in antimicrobial analysis. Additionally, the anti-bacterial and fungal activity is compared by synthesizing various metal ferrites such as MnFe2O4, ZnFe2O4, and Fe3O4. The 50wt% MZF/rGO nanocomposite exhibits significantly high antibacterial activity. However, 10wt% MZF/rGO nanocomposite shows good antifungal activity than Fe3O4, MnFe2O4, ZnFe2O4, MnZnFe2O4, 50wt%, and 80wt% MZF/rGO nanocomposites. These findings suggest that the prepared ferrite nanocomposites hold promise for microbial inhibition.

[Distribution and Drug Resistance of Pathogens Causing Bloodstream Infection in Patients with Hematological Malignancies].

To investigate distribution and drug resistance of pathogens of bloodstream infection in patients with hematological malignancies, in order to provide reference for clinical infection control and treatment. The clinical information of blood culture patients in the hematology department of our hospital from January 2016 to December 2021 was reviewed. They were divided into transplantation group and non-transplantation group according to whether they had undergone hematopoietic stem cell transplantation. The types of pathogens and their drug resistance were analyzed. Two hundred and ninety-nine positive strains of pathogenic bacteria were detected. In the transplantation group, Gram-negative bacteria accounted for 68.5% (50/73), Gram-positive bacteria accounted for 6.8% (5/73), and fungi accounted for 24.7% (18/73). The resistance rate of Escherichia coli to the third-generation cephalosporins was 77.8%, and 11.5% to carbapenems. The resistance rate of Klebsiella pneumoniae to the third-generation cephalosporins was 50.0%, and 56.2% to carbapenems. In the non-transplantation group, Gram-negative bacteria accounted for 64.1% (145/226), Gram-positive bacteria accounted for 31.0% (70/226), and fungi accounted for 4.9% (11/226). Gram-positive bacteria were mainly Enterococcus faecium (6.6%, 15/226) and Coagulase-negative Staphylococci (6.2%, 14/226). The fungi were all Candida tropicalis. The resistance rate of Escherichia coli to the third-generation cephalosporins was 63.8%, and 10.3% to carbapenems. The resistance rate of Klebsiella pneumoniae to the third-generation cephalosporins was 46.3%, and 26.8% to carbapenems. The types of pathogenic bacteria in bloodstream infection in patients with hematological malignancies are varied. Gram-negative bacteria is the main pathogenic bacteria. The resistance of pathogenic bacteria to antibiotics is severe. Antibiotics should be used scientifically and reasonably according to the detection and resistance of pathogenic bacteria.

New Hydroxyphenylacetic Acids and α-Pyrone Derivative from the Deep-Sea Cold Seep Sediment-Derived Fungus Penicillium corylophilum CS-682.

Two pairs of new enantiomeric hydroxyphenylacetic acid derivatives, (±)-corylophenols A and B ((±)-1 and (±)-2), a new α-pyrone analogue, corylopyrone A (3), and six andrastin-type meroterpenoids (4-9) were isolated and identified from the deep-sea cold-seep sediment-derived fungus Penicillium corylophilum CS-682. Their structures and stereo configurations were determined by detailed spectroscopic analysis of NMR and MS data, chiral HPLC analysis, J-based configuration analysis, and quantum chemical calculations of ECD, specific rotation, and NMR (with DP4+ probability analysis). Compound 3 showed inhibitory activity against some strains of pathogenic bacteria.

Antimicrobial activity of the aqueous extract of Acacia (Acacia nilotica) in inhibiting the growth of some pathogenic bacterial strains

The study was conducted in the laboratory of the Department of Biology at the College of Science and Arts in Baljurashi- Baha Region-Kingdom of Saudi Arabia. The aim of the research was studying the effectiveness of the aqueous extract of the Acacia plant Acacia Nilotica on the growth of some of pathogenic bacteria strains and comparing it with Myrrha essential oil (Commiphora Myrrha). The result indicated that the aqueous extract of the Acacia plant (Acacia Nilotica) has a potent antimicrobial activity against all tested organisms expect Pseudomonas spp. which showed resistance against it. The inhibitory level among all tested organisms (Stenotrophomona spp., Achromobacter spp., Shewa Nell spp., Pseudoxanthomas spp., Pseudomonas spp., Bacillus spp. were   14 , 28, 16, 20, 0 and 12 mm  respectively. The highest antibacterial effect was against Achromobacter spp. where the inhibition zone (28mm) and the lowest antimicrobial effect was against Bacillus spp. where the inhibition zone (12mm). By the other hand Myrrha (Commiphora Myrrha) essential oil was very weak or did not cause any inhibition in the tested strains. More studies are needed to determine the antimicrobial activity of aqueous extract of the Acacia plant on other organisms which cause food spoilage, poisoning and food borne diseases.

Rapid Nucleic Acid Detection of Listeria monocytogenes Based on RAA-CRISPR Cas12a System.

Listeria monocytogenes (L. monocytogenes) is a food-borne pathogenic bacteria that frequently contaminates animal-derived food and low-temperature preserved food. Listeriosis caused by its infection has a high mortality rate and poses a serious threat to human health. Therefore, it is crucial to establish a sensitive, rapid and easy-to-operate technique. In this study, a Recombinase Aided Amplification (RAA) assisted CRISPR/Cas12a (RAA-CRISPR/Cas12a) fluorescence platform was established for highly sensitive nucleic acid detection of L. monocytogenes. The established RAA-CRISPR/Cas12a showed high sensitivity and high specificity, with the sensitivity of 350 CFU/mL and 5.4 × 10-3 ng/μL for pure bacterial solution and genomic DNA, and good specificity for 5 strains of Listeria spp. and 14 strains of other common pathogenic bacteria. L. monocytogenes could be detected at an initial concentration of 2.3 CFU/25g within 2 h of enriching the beef in the food matrix, and this method could be applied to food samples that were easily contaminated with L. monocytogenes The results of RAA-CRISPR/Cas12a could be observed in 5 min, while the amplification was completed in 20-30 min. The speed and sensitivity of RAA-CRISPR/Cas12a were significantly higher than that of the national standard method. In conclusion, the RAA-CRISPR/Cas12a system established in this study has new application potential in the diagnosis of food-borne pathogens.

Antimicrobial activity of geranium (Pelargonium graveolens) essential oil and its encapsulation in carioca bean starch ultrafine fibers by electrospinning

Geranium (Pelargonium graveolens) is known for being an aromatic plant rich in bioactive compounds with antibacterial properties. In this study, geranium essential oil (GEO) was extracted and encapsulated in ultrafine bean starch fibers produced by electrospinning as an antibacterial agent. GEO revealed a composition rich in volatile compounds, including citronellol, cis-geraniol, β-linalool, citronellyl formate, and linalool formate. In its free form, GEO exhibited high antibacterial activity against pathogenic bacteria strains (L. monocytogenes, S. aureus, and E. coli). The bean starch fibers, produced with and without the addition of GEO, were uniform and continuous, with an average diameter ranging from 249 to 373 nm. Confocal analysis indicated a uniform distribution of GEO in the fibers, with a loading capacity of 54.0 %, 42.9 %, and 36.5 % for 20 %, 30 %, and 40 % GEO concentrations, respectively. Remarkably, fibers containing 40 % GEO showed a significant reduction in tested bacteria (L. monocytogenes, S. aureus, and E. coli), suggesting promising applications in preventing losses and extending the shelf life of food through active packaging.

Analysis of the Current Situation and Risk Factors of Lower Respiratory Tract Infection among ICU Patients in Guizhou, China During 2019–2022

Objective: This study aims to explore the prevalence, features, and risk factors of lower respiratory tract infections (LRTIs) in the intensive care unit (ICU) of a newly established hospital in Zunyi City. The goal is to devise strategies for preventing LRTIs in the ICU of new hospitals, thereby mitigating the incidence of nosocomial LRTIs in ICU patients. Methods: A case-control study was conducted from March 2019 to December 2022 to investigate the incidence rate of LRTIs in the ICU of a newly constructed hospital in Zunyi City. Patients with LRTIs constituted the case group, while those without LRTIs constituted the control group, where a 1:1 matching principle was adhered to. A single-factor chi-squared (χ2) test was employed to analyze the risk factors, with independent risk factors being explored using a multivariate logistic regression analysis. Results: A total of 169 strains of pathogenic bacteria were isolated, comprising 66.28% gram-negative bacteria, 17.75% gram-positive bacteria, and 15.97% fungi. The most prevalent pathogens included Acinetobacter baumannii (43.20%), Candida albicans (10.65%), and Pseudomonas aeruginosa (8.88%). Of the 82 strains infected by multidrug-resistant bacteria in patients with LRTIs, 81.7% were carbapenem-resistant Acinetobacter baumannii, 9.8% were multidrug-resistant Pseudomonas aeruginosa, and 6.1% were carbapenem-resistant Escherichia coli. Identified risk factors included smoking history, total hospitalization days, ICU stay length, hypoproteinemia, indwelling gastric tube, intubation type, duration of mechanical ventilation, usage of antibacterial drugs, and administration of protein drugs (P < 0.05). Multivariate logistic regression analysis demonstrated that these factors were independent risk factors for nosocomial LRTIs in ICU patients (P < 0.05). Conclusion: ICU patients in our hospital were mainly infected by carbapenem-resistant Acinetobacter baumannii. To prevent LRTIs in patients, tailored preventive measures should be developed and the rational use of antibacterial drugs should be promoted.

The intricate relationship of G-Quadruplexes and bacterial pathogenicity islands

The dynamic interplay between guanine-quadruplex (G4) structures and pathogenicity islands (PAIs) represents a captivating area of research with implications for understanding the molecular mechanisms underlying pathogenicity. This study conducted a comprehensive analysis of a large-scale dataset from reported 89 pathogenic strains of bacteria to investigate the potential interactions between G4 structures and PAIs. G4 structures exhibited an uneven and non-random distribution within the PAIs and were consistently conserved within the same pathogenic strains. Additionally, this investigation identified positive correlations between the number and frequency of G4 structures and the GC content across different genomic features, including the genome, promoters, genes, tRNA, and rRNA regions, indicating a potential relationship between G4 structures and the GC-associated regions of the genome. The observed differences in GC content between PAIs and the core genome further highlight the unique nature of PAIs and underlying factors, such as DNA topology. High-confidence G4 structures within regulatory regions of Escherichia coli were identified, modulating the efficiency or specificity of DNA integration events within PAIs. Collectively, these findings pave the way for future research to unravel the intricate molecular mechanisms and functional implications of G4-PAI interactions, thereby advancing our understanding of bacterial pathogenicity and the role of G4 structures in pathogenic diseases.

EFFECT OF DIFFERENT SOLVENT EXTRACTS ON THE YIELD AND IN VITRO ANTIBACTERIAL ACTIVITY, WITH GC-MS ANALYSIS OF ACTIVE EXTRACTS FROM VERNONIA AMYGDALINA LEAVES

Vernonia amygdalina, commonly known as ‘Bitter leaf’, is a small perennial shrub with various medicinal properties including the treatment of stomach disorders, fever symptoms, diabetes, hypertension, and coughs. V. amygdalina is a potent source of antibacterial properties that may be beneficial in preventing bacterial infections and associated diseases such as fever and diarrhea. V. amygdalina also has been extensively studied for its antioxidant, anti-inflammatory, antifungal, anticancer and antidiabetic properties. The present study aims to determine the most efficient solvent for extracting antibacterial-rich V. amygdalina extracts. Dried leaves of V. amygdalina were extracted using several solvents (methanol, ethanol, and dichloromethane) to assess the extraction yield. The antibacterial potential of all extracts against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated using the agar disc diffusion assay. The profiling of the active extract was accomplished using gas chromatography coupled with mass spectrometry (GC-MS). Among the solvents tested, ethanol exhibited the highest extraction productivity, with a percentage yield of 49.20%. The dichloromethane extract displayed the highest inhibition zones against all bacteria strains ranging from 16.67 ± 1.20 mm to 21.33 ± 0.5 mm at 200 mg/mL. The GC-MS analysis of dichloromethane extract identified compounds such as phytol, flavonoids, vitamin E, and squalene. The findings of this study revealed that the choice of the extraction solvent is greatly affecting the antibacterial efficacy of V. amygdalina. In conclusion, the efficacy of V. amygdalina against pathogenic bacteria strains could be explored for further pharmaceutical application and should be encouraged in the development and production of new antibiotics.

Effect of sunflower oil nanoemulsions on the growth and lifespan extension of the Caenorhabditis elegans

Caenorhabditis elegans has been used as a central model system for broad-spectrum research studies across diverse modern biological domains. A study was conducted to evaluate the potential of sunflower oil-based nanoemulsions for lifespan enhancement in stressed C. elegans worms, that had been fed on nematode growth media (NGM) seeded with two strains of pathogenic bacteria (Salmonella enterica serovar Typhimurium and Staphylococcus aureus). Nanoemulsions were fabricated using HI-CAP® 100 modified food starch, and their stability was tested under different processing conditions (temperature, pH, ionic strength) over a period of 5 months. Lifespan assay results demonstrated that sunflower-oil-based nanoemulsions with droplet size 170.2±9.3 nm, significantly facilitated the growth of C. elegans under stress conditions and increased the lifespan of the worms from the previously recorded 11 days to 26 days in the current research study.

Aspercitrininone A, novel antibacterial polyketide featuring unusual spiral skeleton from Aspergillus cristatus

Aspercitrininone A (1), a novel polyketide featuring an unprecedented tetracyclic 6/6/6/5 spiral skeleton, was obtained from the rice fermentation cultures of the fungus Aspergillus cristatus together with five known compounds (2–6). Their structures were determined by HRESIMS data, 1D and 2D NMR spectroscopic analysis, and electronic circular dichroism (ECD) calculations. Aspercitrininone A was revealed as a new type of C/D cycle spiral structure and an unusual addition product of o-quinoid form citrinin with 2-methylterrefuranone. Compounds 1, 4, and 5 exhibited potent antibacterial activities with minimal inhibitory concentration (MIC) values from 13.2 to 67.3 μg/mL against four strains of human pathogenic bacteria in vitro.

Studies on bioactivities of Manuka and regional varieties of honey for their potential use as natural antibiotic agents for infection control related to wound healing and in pharmaceutical formulations

<abstract> <p>Presently, most of the reported infections are of a bacterial origin; however, this leads to a limit within the literature and research around infections caused by fungal pathogens, which are now developing resistance to antibiotic medicines. Of the natural antimicrobial agents, honey has been observed with demonstrable and highly exploitable antimicrobial and infection control related to wound healing properties; therefore, it has been incorporated into many standard pharmaceutical formulations. Generally, these products utilize a pure sample of honey as a bioactive ingredient in a product which has been purposely designed for the convenience of application. This article aims to review information available from published reports on various bioactivities of a variety of medical-grade honey products, including manuka and other conventional non-manuka types sourced from different floral types and geographical regions. Additionally, this review highlights the antibiotic activities of various types of honey products tested against pathogenic strains of bacteria, yeast and fungi, and their applications in the formulation of healthcare products.</p> </abstract>

Wpływ metody inokulacji roślin kukurydzy patogenami bakteryjnymi na powstawanie i rozwój objawów chorobowych

The basis of phytopathological diagnostics are Koch’s postulates, the fulfillment of which allows determining whether the examined microorganism is the cause of a given disease. The third of these postulates specifies that inoculation of a healthy host plant with a pure culture of the putative pathogen must result in the induction of disease symptoms similar or the same to those occurring in natural con¬ditions. To meet Koch’s third postulate, a pathogenicity test result is required, and incorrect interpretation may lead to rejection of cor¬rect results. Many years of research on bacteriosis of crop plants, including corn, have shown that the symptoms of the disease resulting from inoculation with the tested strain of bacteria may vary, depending on the inoculation method used and the incubation conditions of the inoculated plants. The conducted research determined the impact of various methods of inoculating corn plants with selected strains of pathogenic bacteria isolated from diseased corn plants on the occurrence and development of disease symptoms. These strains belonged to the species Pectobacterium carotovorum subsp. carotovorum, Dickeya zeae, Pantoea ananatis, Pantoea agglomerans and Enterobacter cloaceae subsp. dissolvens. It was observed that the symptoms of the disease caused by the inoculation methods used dif¬fer from the symptoms observed in natural conditions. Moreover, regardless of the species affiliation of the tested bacterial strains, the observed symptoms were similar within a given inoculation method. Also, regardless of the species affiliation of the tested strain, incuba¬tion of inoculated plants in a culture chamber with optimal conditions for the development of the disease resulted in the acceleration of symptoms and disease development.

Dihydrobenzothiazole coupled N-piperazinyl acetamides as antimicrobial agents: Design, synthesis, biological evaluation and molecular docking studies.

Substituted saturated N-heterocycles have gained momentum as effective scaffolds for the development of new drugs. In this study, we coupled partly saturated benzothiazoles with substituted piperazines and evaluated their antimicrobial activity. Following a three-step reaction sequence from commercially available cyclic 1,3-diones, a series of novel 2-[4-substituted-1-piperazinyl]-N-(7-oxo-4,5,6,7-tetrahydrobenzo[d]thiazol-2-yl)acetamides (7a-af) were synthesised. 2-Amino-5,6-dihydro-benzo[d]thiazol-7(4H)-ones, obtained through the condensation of cyclohexane-1,3-diones with thiourea, were acetylated with chloroacetic chloride and then reacted with N-substituted piperazines 6a-p to give the desired products 7a-af in excellent yields. All 32 new compounds were fully characterised by their 1 H-nuclear magnetic resonance (NMR), 13 C-NMR and high-resolution mass spectrometry spectra. The synthetic compounds 7a-af were tested in vitro for their efficacy as antimicrobials against pathogenic strains of Gram-positive and Gram-negative bacteria, Streptococcus mutans and Salmonella typhi, respectively, as well as against fungal strains, including Candida albicans 3018 and C. albicans 4748. Ciprofloxacin and fluconazole served as the reference drugs. While compounds 7c and 7l showed inhibition against fungal strains with zones of inhibition of 11 and 1 mm, respectively, four analogues (7d, 7l, 7n, and 7r) demonstrated strong antibacterial action (zone of inhibition in the range of 10-15 mm). Three compounds (7j, 7l, and 7w) also exhibited moderate antitubercular activity (MIC: 6.25 µg/mL) against Mycobacterium tuberculosis H37Rv. Molecular docking investigations and the predicted physicochemical and ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties for the potent compounds made this scaffold useful as a pharmacologically active framework for the development of potential antimicrobial hits.

7295 elderly hospitalized patients with catheter-associated urinary tract infection: a case-control study

BackgroundCatheter-associated urinary tract infection (CAUTI) ranks second among nosocomial infections in elderly patients after lung infections. Improper treatment can lead to death. This study analysed the risk factors, pathogen distribution, clinical characteristics and outcomes of CAUTI in elderly inpatients with a large sample size to provide evidence for clinical prevention and control.MethodsBased on the HIS and LIS, a case‒control study was conducted on all hospitalized patients with indwelling urinary catheters ≥ 60 years old from January 1, 2019, to December 31, 2022, and the patients were divided into the CAUTI group and the non-CAUTI group.ResultsCAUTI occurred in 182 of 7295 patients, and the infection rate was 3.4/per 1000 catheter days. Urine pH ≥ 6.5, moderate dependence or severe dependence in the classification of self-care ability, age ≥ 74 years, male sex, hospitalization ≥ 14 days, indwelling urinary catheter ≥ 10 days, diabetes and malnutrition were independent risk factors for CAUTI (P < 0.05). A total of 276 strains of pathogenic bacteria were detected in urine samples of 182 CAUTI patients at different times during hospitalization. The main pathogens were gram-negative bacteria (n = 132, 47.83%), followed by gram-positive bacteria (n = 91, 32.97%) and fungi (n = 53, 19.20%). Fever, abnormal procalcitonin, positive urinary nitrite and abnormal urination function were the clinical characteristics of elderly CAUTI patients (P < 0.001). Once CAUTI occurred in elderly patients, the hospitalization days were increased by 18 days, the total hospitalization cost increased by ¥18,000, and discharge all-cause mortality increased by 2.314 times (P<0.001).ConclusionThe situation of CAUTI in the elderly is not optimistic, it is easy to have a one-person multi-pathogen infection, and the proportion of fungi infection is not low. Urine pH ≥ 6.5, moderate or severe dependence on others and malnutrition were rare risk factors for elderly CAUTI in previous studies. Our study analysed the clinical characteristics of CAUTI in the elderly through a large sample size, which provided a reliable basis for its diagnosis and identified the adverse outcome of CAUTI.

Complex effects of the exo-xis region of the Shiga toxin-converting bacteriophage Φ24B genome on the phage development and the Escherichia coli host physiology

Lambdoid bacteriophages are excellent models in studies on molecular aspects of virus-host interactions. However, some of them carry genes encoding toxins which are responsible for virulence of pathogenic strains of bacteria. Shiga toxin-converting bacteriophages (Stx phages) encode Shiga toxins that cause virulence of enterohemorrhagic Escherichia coli (EHEC), and their effective production depends on Stx prophage induction. The exo-xis region of the lambdoid phage genome consists of genes which are dispensable for the phage multiplication under laboratory conditions; however, they might modulate the virus development. Nevertheless, their exact effects on the phage and host physiology remained unclear. Here, we present results of complex studies on the role of the exo-xis region of bacteriophage Φ24B, one of Stx2b phages. Transcriptomic analyses, together with proteomic and metabolomic studies, provided the basis for understanding the functions of the exo-xis region. Genes from this region promoted lytic development of the phage over lysogenization. Moreover, expression of the host genes coding for DnaK, DnaJ, GrpE, and GroELS chaperones was impaired in the cells infected with the Δexo-xis phage mutant, relative to the wild-type virus, corroborating the conclusion about lytic development promotion by the exo-xis region. Proteomic and metabolomic analyses indicated also modulation of gad and nrf operons, and levels of amino acids and acylcarnitines, respectively. In conclusion, the exo-xis region controls phage propagation and host metabolism by influencing expression of different phage and bacterial genes, directing the virus to the lytic rather than lysogenic developmental mode.

Comparative Study of Antibacterial Activity of Elephantopus scaber Linn. and Elephantopus mollis Kunth. Extract

Elephantopus scaber Linn.  and E. mollis Kunth. are medicinal plant that are traditionally used in Indonesia. This research aimed to determine and compare the antibacterial activity of leaf, stem, and root extracts of the two Elephantopus species against various pathogen bacteria strains. The leaves, stem, and roots of E. scaber Linn. and E. mollis Kunth. were extracted using a Soxhlet apparatus. The disk diffusion method for screening antibacterial activity was conducted with a concentration of 50 mg/mL. The activities of the extracts were determined by Minimum Inhibitory Concentration (MIC) assay using broth microdilution method at a concentration range of 2500 to 1.2 µg/mL against nine human pathogenic bacteria. The results showed that all tested extracts demonstrated antibacterial activitied at varying degrees on all pathogen bacteria strains used in this study. The n-hexane and ethyl acetate extracts from both plants were potent antibacterials with MIC values of 19-156 µg/mL against Staphylococcus aureus ATCC 25923, Streptococcus mutans ATCC 25 175, Vibrio cholerae Inaba, and Pseudomonas aeruginosa ATCC 27853. The present study also revealed that among the bacteria tested, S. mutans ATCC 25175 was the most susceptible to antibacterial properties of E. scaber Linn. and E. mollis Kunth., especially in ethyl acetate fractions (MIC 19 and 39 µg/mL, respectively).    The findings suggested that the leaves of both plants hold promise as sustainable bioresources for the development of antibacterial agents. Additionally, ethyl acetate and n-hexane extracts were found to be particularly effective for obtaining natural antibacterial agents from these plants. However, further optimization of the extraction process is needed.

Acidifying remediation and microbial bioremediation decrease ammoniacal nitrogen, orthophosphates, and total suspended solids levels in intensive Nile tilapia farming under biofloc conditions

In biofloc technology (BFT) systems, the formation of bioflocs and accumulation of suspended solids are constant, which can cause impairments in water quality parameters and negatively impact the growth performance of farmed animals. We herein investigated two integrated solutions for intensive farming of Nile tilapia under BFT conditions. In this study, EUROGUARD® SOFT F60 (60% formic acid and 40% lignosulfonic acid) was used as the acidifying remediator, while ADD LIFE PRO BACIL ACQUA based on a mixture of Bacillus spp. was used as the microbial bioremediator. First, assays were conducted for in vitro inhibition tests of acidifying remediator against seven different strains of pathogenic bacteria. A dose-response test was performed for both acdifying bioremediator and microbial bioremediator. Then, an in vivo assay was conducted over four weeks. In 12 BFT units with a capacity of 250 L each, one group received the acidifying remediator at a concentration of 2.5 part per million (ppm), while another group received the bioremediator Bacillus spp. at a concentration of 0.10 g m−3 directly in tank water. A control group without aditives was also established, all in quadruplicate. The culture environment was evaluated daily by measuring dissolved oxygen, temperature, floc volume and weekly by measuring total ammonia nitrogen (TAN), ammoniacal nitrogen (N−NH3), nitrite (N-NO2), nitrate (N-NO3), alkalinity (CaCO3), orthophosphate (PO43−), electrical conductivity (μS−1), potential of hydrogen (pH) and total suspended solids (TSS). At the end of the period, in the in vivo assay, the bacterial community in the BFT, hematological parameters, and zootechnical performance of the tilapia were evaluated. In in vitro inhibition tests, the acidifying remediator inhibited the growth of all pathogenic bacteria evaluated. All concentrations reduced the count of filamentous bacteria, and the pH values were dose-dependent. Both in vivo treatments altered bacterial communities. Both treatment groups had lower concentrations of N-NH3, N-NO2 and N-NO3. PO43− content was lower in the acidifying remediator group. CaCO3 was higher in the treatment groups, while TSS was higher in the control group. Both remediation strategies were efficient in removing nitrogenous chemical compounds. However, the acidifying remediator concomitantly reduced N-NH3, N-NO2− and PO43− levels, becoming a powerful ally in the reduction of aquaculture effluents, as well as in the reduction of potentially pathogenic bacteria in tilapia culture.

Two different coordination polyhedra in the crystal structure of a novel Zn(II) hybrid complex: DFT investigation, biological activities and emission properties

This work centers around the search for sophisticated hybrid compounds with versatile applications. A new compound, denoted as (C6H8NO)3[ZnCl4][ZnCl3(H2O)] (1), was synthesized and thoroughly characterized. The structural features were determined through the use of various analytical techniques, including spectroscopy (FT-IR, Raman), thermo-gravimetric analysis, and optical studies encompassing ultraviolet-visible spectroscopy, nonlinear optical (NLO), and fluorescence measurements. The crystalline arrangement was explored through single crystal X-ray diffraction analysis, revealing a triclinic crystal system with the P1¯ space group. The molecular composition comprises three distinct mono-protonated p-aminophenol (C6H8NO)+ cations alongside two isolated tetrahedral anions ([ZnCl4]2− and [ZnCl3(H2O)]−). The stabilization of this hybrid compound accounts for a wide array of interactions, including hydrogen bonds and π–π (ring-ring) interactions, as deduced from comprehensive analyses. Theoretical investigations were conducted employing density functional theory (DFT) at the Cam-B3LYP/Lanl2dz level, accompanied by a detailed examination of the atoms in molecules (AIM) utilizing the BCP point. Furthermore, the nonlinear optical (NLO) properties were assessed, encompassing the evaluation of dipole moment, linear polarizability, and second hyperpolarizability. Notably, the compound exhibited pronounced solid-state fluorescence when excited at 350 nm, displaying intense emission within the blue spectrum. The correlated color temperature (CCT) value was measured at 7011 K, indicative of a "cool" white light emission. Basically, the synthesized compound exhibited antibacterial efficiency against several strains of human pathogenic bacteria in vitro and considerable enzyme inhibitory activity against pathogenic microorganisms. This research underscores the characteristics of (1), making it an appealing contender for a variety of applications.

Drug resistance and influencing factors of biofilm bacteria in upper urinary calculi patients with double J stent indwelling

ObjectiveTo analyze the distribution and drug resistance of biofilm bacteria infected with upper urinary calculi patients with double J stent indwelling, and to explore the influencing factors of Biofilm Bacteria Infections.MethodsA total of 400 patients with upper urinary calculi who adopted double J stent inserting in our hospital from January 2019 to January 2022 were included. Urine and double J stent samples were collected, pathogen cultures were performed, and then drug sensitivity test analysis was carried out for isolates. Univariate and multivariate logistic regression analyzes were used to analyze the influencing factors of patients with double J stent associated biofilm bacteria infections.ResultsA total of 13 strains (3.2%) of biofilm bacteria were detected in urine samples and 168 strains (42%) in double J stent samples (P < 0.05), 95 strains (23.7%) of pathogenic bacteria were separated from urine samples and 117 strains (29.2%) from double J-stent samples (P > 0.05). Escherichia coli were the most common bacteria. There was significantly higher drug resistance observed in biofilm bacteria versus urine-cultured pathogens (P < 0.05). Advanced age, long-term catheterization, inadequate water intake, hypoproteinemia, abnormal renal function, and diabetes mellitus were independent risk factors for biofilm bacteria infection associated with double J stent(P < 0.05).ConclusionAmong the upper urinary calculi patients with double J stent indwelling, the positive rate and drug resistance of biofilm bacteria obtained from double J stent were significantly higher than that from urine. More attention should be paid to the factors that influence biofilm bacteria infections.