Inhibition Of Nucleic Acid Synthesis Research Articles

Medicinal Herbs: Promising Immunomodulators for the Treatment of Infectious Diseases.

Humans are constantly at high risk of emerging pandemics caused by viral and bacterial infections. The emergence of new pandemics is mainly caused by evolved viruses and bacteria that are highly resistant to existing medications. The rapid evolution of infectious agents demands the urgent investigation of new therapeutic strategies to prevent and treat these infections at an early stage. One of these therapeutic strategies includes the use of medicinal herbs for their antibacterial and antiviral properties. The use of herbal medicines as remedies is very ancient and has been employed for centuries. Many studies have confirmed the antimicrobial activities of herbs against various pathogens in vitro and in vivo. The therapeutic effect of medicinal herbs is mainly attributed to the natural bioactive molecules present in these plants such as alkaloids, flavonoids, and terpenoids. Different mechanisms have been proposed for how medicinal herbs enhance the immune system and combat pathogens. Such mechanisms include the disruption of bacterial cell membranes, suppression of protein synthesis, and limitation of pathogen replication through the inhibition of nucleic acid synthesis. Medicinal herbs have been shown to treat a number of infectious diseases by modulating the immune system's components. For instance, many medicinal herbs alleviate inflammation by reducing pro-inflammatory cytokines (e.g., tumor necrosis factor-alpha (TNF-α), interleukin-1, IL-6) while promoting the production of anti-inflammatory cytokines (e.g., IL-10). Medicinal herbs also play a role in defense against viral and intracellular infections by enhancing the proliferation and functions of natural killer cells, T-helper-1 cells, and macrophages. In this review, we will explore the use of the most common herbs in preventing and treating infectious and non-infectious diseases. Using current and recently published studies, we focus on the immunomodulatory and therapeutic effects induced by medicinal herbs to enhance immune responses during diseases.

Unlocking the Antibacterial Potential of Xanthone from Calophyllum Species: Inhibition of Nucleic Acid Synthesis

AbstractPlants are valuable resources for the development of novel pharmaceutical products. The increasing threat to global health caused by antibiotic resistance remains a serious concern, driven a need to discover and evaluate novel anti‐bacterial agents. Calophyllum species are known for having excellent biological activity due to its secondary metabolites, such as xanthone. Numerous xanthones have been found to possess anti‐bacterial properties that are effective against plant pathogens, hence can be applied to fight human pathogens. Topoisomerase enzymes (DNA gyrase and topoisomerase IV) are DNA metabolism enzymes that possess distinct roles as unlinking enzymes during DNA replication. Nucleic acid synthesis inhibition reduces bacteria proliferation through the inhibition of topoisomerase enzymes that are essential for bacterial growth. The xanthone isolated from Calophyllum and its anti‐bacterial were discussed in this review. Besides, molecular docking simulations were applied to explore the potential binding mode of xanthones to DNA metabolism enzymes. The docking study displayed that biscaloxanthone is a good topoisomerase enzymes inhibitor compared to their co‐cystalize ligand, novobiocin and BDBM50198240. The complied information and molecular docking simulations suggested that xanthone isolated possesses potential anti‐bacterial agents inhibiting nucleic acid synthesis. Besides, it suggested that the anti‐microbial activity of xanthone contributes from the topoisomerase enzyme‘s inhibition.

Antibacterial spectrum of medicinal plants: A review

Medicinal plants exerted their antibacterial effects through many mechanisms included inhibition of cell wall synthesis, inhibition of cell membrane synthesis, disruption of cytoplasmic membrane, inhibition of bacterial proteins synthesis, inhibition of nucleic acid synthesis, inhibition of energy metabolism, as well as inhibition of bacterial virulence factors. The current review highlighted the medicinal plants with antibacterial activity with their spectrum of action.

The potency of kitolod leaves (Hipobroma longiflora) as traditional medicine for conjunctivitis during the COVID-19 pandemic: a brief review

During the coronavirus disease 2019 (COVID-19) pandemic, most activities have transformed into digital ones, including computer usage. The digital screen on the computer has blue light radiation which can activate inflammatory cytokines of the eye surface and cause various disorders including includes conjunctivitis. Kitolod leaves (Hippobroma longiflora) have been used traditionally to treat conjunctivitis. This paper aimed to describe the potency of kitolod leaves for conjunctivitis. This is a narrative literature review using publications gathering from PubMed and Google Scholar published since 2013 with exclusion criteria were the animal studies. The keywords of COVID-19 pandemic, blue light, conjunctivitis, H. longiflora, traditional therapy were used. Boolean logic "AND" was used to find specific international scientific publications in PubMed. Forty selected publications were gathered, summarized and then narrated. The kitolod leaves contains bioactive substances i.e. flavonoids, alkaloids, and saponins which can inhibit S. aureus growth as the main cause of conjunctivitis. The mechanism of antibacterial of these bioactive substances through inhibition of nucleic acid synthesis, disruption of cytoplasmic membrane function, and inhibition of energy formation process. Kitolod leaves is potential to develop as traditional medicine for conjunctivitis. However, further studies are required to obtain the best standardized extract and to evaluate its clinical efficacy and safety.

THE ANTIOXIDANT PROTECTION SYSTEM STATE OF RATS UNDER EXPERIMENTAL DOXORUBICIN INTOXICATION AND THE EFFECTS OF CORRECTING FACTORS

Introduction. The doxorubicin model was used for research, which, according to many authors, most adequately reproduces heart failure of varying degrees of severity. Doxorubicin is an antibiotic that has a cytostatic effect. The mechanism of its action consists of interaction with DNA, formation of free radicals, and inhibition of nucleic acid synthesis. The doxorubicin action and the development of hypoxia are accompanied by the activation of oxidative stress, the strengthening of free radical processes, and changes in the metabolism of carbohydrates, proteins, and lipids.
 The aim of the study – the effect of the drug “Bendamine” on the indicators of antioxidant protection of the body of rats under experimental simulation of heart failure.
 Research Methods. Modeling of heart failure was performed on sexually mature male Wistar rats with a body weight of 180–200 g. In blood and myocardial homogenate, the level of lipid peroxidation products, the activity of antioxidant enzymes, and the level of reduced glutathione were determined against the background of doxorubicin intoxication and when using the drug “Bendamine”.
 Results and Discussion. During doxorubicin intoxication, LPO processes are enhanced in rats, which is indicated by the increased lipid hydroperoxides, diene conjugates, and TBA-active products in the blood and the homogenate of the rat myocardium of the first experimental group. It is worth noting that the inhibition of the antioxidant defense system was also established in intoxicated rats, as indicated by the low level of both enzymatic and non-enzymatic links of the antioxidant system. It was established that bendamine has a corrective effect on rats' oxidative stress conditions inherent in doxorubicin-induced heart failure. The drug “Bendamine” inhibits the excessive formation of POL products in pathologically changed tissues of the heart of rats and has an inducing effect on the system of antioxidant protection.
 Conclusions. The influence of the drug "Bendamine" on the indicators of antioxidant protection of the body of rats under experimental simulation of heart failure was studied. Its antioxidant properties have been proven.
 
 

Chemical Constitution, In-silico Molecular Docking Studies and Antibacterial Activity of Flower Essential Oil of Artabotrys hexapetalus

The isolation of the volatile constituents from the flowers of Artabotrys hexapetalus was carried out using a simple headspace solvent-trapping technique and identified by GC-MS analysis. The major compounds are ethyl acetate 53.6%, isobutyl acetate (29.4%) and ethyl benzoate (14.2%). The odour of the solution obtained from this method was found to be similar to that of the fresh flowers. Further the essential oil from A. hexapetalus was obtained for the first time from India by hydro distillation using a Clevenger type apparatus and analysed by GC-MS. The plant yielded 1.26%, of the essential oils from the flower. The analysis lead to the identification of 28 compounds representing 96.17% of the total oil. The essential oil consists of predominantly oxygenated sesquiterpenes (51.91%) followed by sesquiterpenes (43.31%) and small quantities of monoterpenes (1.24%) and other compounds (1.34%). The main constituents of the essential oil obtained from the flowers of A.hexapetalus are β-caryophyllene (18.69%), caryophyllene oxide (14.54%), cubenol (12.53%) and ledol (11.5%). The essential oil showed antibacterial activity against bacterial strains Streptococcus pneumonia, Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa exhibiting a zone of inhibition of 16.4, 15.7, 17.5 and 14.5 mm and MIC value of 2.5, 5.0, 2.5, 5.0 mg/ml respectively. Molecular docking analysis indicated that the essential oil constituents are nucleic acid and cell wall synthesis inhibitors. So it is worth to include this in cosmetics and fragrances.

High-Throughput Chemical Screen on Acute Myeloid Leukemia Stem Cells Identifies Novel Anti-LSC Compounds

Acute myeloid leukemia (AML) is an aggressive form of blood cancer defined by the uncontrolled proliferation and clonal expansion of immature myeloblast cells in the blood and bone marrow, leading to hematopoietic failure. Despite the use of aggressive and cytotoxic standard-of-care drugs, patients often relapse and succumb to the disease partially due to the inability of medically unfit patients to withstand the cytotoxic treatments, regrowth from minimal residual disease and the chemo-resistant nature of leukemic stem cells (LSCs) which can remain in a quiescent state and reside in a protective bone marrow niche. Hence, novel therapies targeting unique leukemic stem cell biology are highly needed to eliminate and avoid reoccurrence.High-throughput screens of human AML LSCs are not performed due to technical issues such as low LSC frequency within primary samples, an inability to purify LSCs, and the difficulty maintaining and expanding primary patient samples and LSCs in vitro. We were able to optimize conditions for a 4-week in vitro large-scale expansion (>600 million bulk) of the primary human AML sample 8227 (OCI-AML-8227), functionally validated to be enriched for LSCs in long-term xenotransplant assays (Eppert et al., 2011). These optimized conditions enabled the isolation and maintenance of the LSC-containing fraction for a chemical screen. We isolated the CD34+ LSC-containing fraction (>90% purity) and performed a high-throughput screen of 11,166 chemical molecules using a CellTiter Glo assay followed by a counter screen against normal CD34+ cord blood (CB) hematopoietic stem and progenitor cells.From this HT screen, a total of 61 hits had >70% inhibition on CD34+ 8227 cells and <30% inhibition on CD34+ CB cells. We also identified glucocorticoids, which were also identified in our prior small-scale anti-LSC screen where they were found to specifically drive human LSCs to terminally differentiate (Laverdière & Boileau, et al., 2018).We then performed dose response assays for each candidate compounds and confirmed 35 potent anti-LSC compounds with IC 50 < 1 μM. This refined the types of compounds to including anti-apoptotic inhibitors, GSK inhibitors, protease inhibitors, metabolism inhibitors, HDAC inhibitors, BET inhibitors, nucleic acid synthesis inhibitors, cell cycle inhibitors and Wnt/β-catenin inhibitors. This is interesting as some of the classes of these compounds (inhibitors of GSK, BET, nucleic acid synthesis, Wnt/β-catenin and metabolism) have been shown to target bulk and leukemic stem cells in AML in vitro and in vivo.We now aim to examine LSC eradication in a panel of genetically defined primary AMLs confirmed through in vitro and in vivo assays. Our goal is to be able to understand and establish the molecular mechanisms and biomarkers on primary functional LSCs. DisclosuresNo relevant conflicts of interest to declare.

Is the Antibacterial Activity of Multi-Walled Carbon Nanotubes (MWCNTs) Related to Antibiotic Resistance? An Assessment in Clinical Isolates.

Antimicrobial resistance has spread globally, compromising the treatment of common infections. This feature is particularly harmful for nosocomial pathogens that can survive on hospital surfaces. Research studies have been conducted to evaluate new materials that are able to counteract the microbial growth and the colonization of the hospital environment. In this context, nanotechnologies have showed encouraging applications. We investigated the antibacterial activity of multi-walled carbon nanotubes (MWCNTs), both pristine (p) and functionalized (f), at concentrations of 50 and 100 μg mL−1, against bacterial strains isolated from hospital-acquired infections, and this activity was correlated with the antibiotic susceptibility of the strains. The inhibiting effect of MWCNTs occurred for both types and doses tested. Moreover, f-MWCNTs exerted a greater inhibiting effect, with growth decreases greater than 10% at 24 h and 20% at 48 h compared to p-MWCNTs. Moreover, a lower inhibitory effect of MWCNTs, which was more lasting in Gram-positives resistant to cell wall antibiotics, or temporary in Gram-negatives resistant to nucleic acid and protein synthesis inhibitors, was observed, highlighting the strong relation between antibiotic resistance and MWCNT effect. In conclusion, an antimicrobial activity was observed especially for f-MWCNTs that could therefore be loaded with bioactive antimicrobial molecules. However, this potential application of CNTs presupposes the absence of toxicity and therefore total safety for patients.

Aerobacterial Vaginosis among Women Attending an Infertility Clinic at a Tertiary Care Hospital in Chennai, India and Susceptibility Pattern of Isolates

Genital infections and subsequent vaginosis diagnosed through high vaginal swab in women is caused due to fungi or bacteria. The presented study focused on determining the types, numbers and antibacterial susceptibility pattern of aerobic bacteria causing vaginosis in 147 female patients attending infertility centre in Chennai, Tamil Nadu, India. Candida spp. caused 17% of infections with 15.7% of vaginosis caused by E.coli, Klebsiella spp., Acinetobacter spp., Citrobacter spp. and Gram positive cocci – Methicillin Sensitive Staphylococcus aureus (MSSA), Coagulase Negative Staphylococci(CONS), Staphylococcus aureus and Enterococcus spp. causing 12.9% of vaginitis in the study population. A total of 20 different antibiotics – cell wall inhibitors, protein synthesis inhibitors and nucleic acid synthesis inhibitors; were tested to determine the response of bacterial isolates by Kirby-Bauer disc diffusion method. The study result determined that the most effective drug for treating Gram positive bacterial vaginitis as per CLSI guidelines based on susceptibility pattern as: Linezolid(100%), Gentamycin(91.6%), Amikacin(87.5%),Erythromycin(79.2%), Co-Trimoxazole(72.2%), Ciprofloxacin(65.6%) and least Chloramphenicol(44.3%). High level gentamycin(83.3%) was found to be effective in treating Enterococci. The descending order of susceptibility of Gram negative aerobacteria causing vaginitis as per CLSI guidelines are: Amikacin(87.5%), Gentamycin(82.5%), Cefoperazone sulbactam (76.3%), Ciprofloxacin(68.5%), Ceftazidime(62.5%) and least Amoxyclav(25%).All Gram negative bacteria tested were susceptible to– Imipenem and Meropenem as well as Chloramphenicol. Ceftriaxone (87.5%) and Nitrofurantoin(72.3%) among other antibiotics was effective against Gram negative bacteria while all Enterobacteriaceae members were found to be resistant to tetracycline.

A review: Mechanism of action of antiviral drugs

Antiviral drugs are a class of medicines particularly used for the treatment of viral infections. Drugs that combat viral infections are called antiviral drugs. Viruses are among the major pathogenic agents that cause number of serious diseases in humans, animals and plants. Viruses cause many diseases in humans, from self resolving diseases to acute fatal diseases. Developing strategies for the antiviral drugs are focused on two different approaches: Targeting the viruses themselves or the host cell factors. Antiviral drugs that directly target the viruses include the inhibitors of virus attachment, inhibitors of virus entry, uncoating inhibitors, polymerase inhibitors, protease inhibitors, inhibitors of nucleoside and nucleotide reverse transcriptase and the inhibitors of integrase. The inhibitors of protease (ritonavir, atazanavir and darunavir), viral DNA polymerase (acyclovir, tenofovir, valganciclovir and valacyclovir) and of integrase (raltegravir) are listed among the Top 200 Drugs by sales during 2010s. Still no effective antiviral drugs are available for many viral infections. Though, there are a couple of drugs for herpesviruses, many for influenza and some new antiviral drugs for treating hepatitis C infection and HIV. Action mechanism of antiviral drugs consists of its transformation to triphosphate following the viral DNA synthesis inhibition. An analysis of the action mechanism of known antiviral drugs concluded that they can increase the cell’s resistance to a virus (interferons), suppress the virus adsorption in the cell or its diffusion into the cell and its deproteinisation process in the cell (amantadine) along with antimetabolites that causes the inhibition of nucleic acids synthesis. This review will address currently used antiviral drugs, mechanism of action and antiviral agents reported against COVID-19.

Structural aspects, conformational preference and other physico-chemical properties of Artesunate and the formation of self-assembly with graphene quantum dots: A first principle analysis and surface enhancement of Raman activity investigation

Artesunate and its derivatives belong to a family of compounds that are highly effective against Malaria. This drug is active against several other conditions like neurodegerative diseases and cancer. The compound forms a metabolite dihydroartemisinine, which contain an endoperoxide bridge that is stimulated by heme iron leading to oxidative stress, protein and nucleic acid synthesis inhibition, morphologic changes and reduced growth and survival of parasites. This manuscript examines the structure and conformational preferences of the compound and investigates the energy and reactivity descriptors using computational simulations. Studies indicates that the compound forms stable self-assemblies with graphene quantum dots and modified graphene quantum dots, where the more stable complex was formed with the modified system. This self-assembly formation leads to enhancement in Raman activity of the compound after complex formation, hence can be used an analytical tool for the detection of the compound in a mixture. Natural bond orbital analysis examines the various intramolecular electron delocalisations. This drug is found to be a nonlinear optically active compound with respect to standards materials like urea and paranitroacetanilide. We also report the non covalent interactions present in the molecule, reduced density gradient, Lapalcian electron density and local information entropy of the molecule.

Isolation and selection of Bacillus strains with high potential probiotic that used in catfish farming (Pangasianodon hypophthalmus)

In this study, we isolated 28 strains of Bacillus spp. from water samples, catfish pond mud samples and earthworm manure (Perionyx excavates). By the cross-streak agar methods, 22 Bacillus strains showed the inhibition ability to Edwardsiella ictaluri, which caused Bacillary Necrosis Pangasius (BNP) in catfish (Pangasianodon hypophthalmus). Both Bacillus sp. Q16 and Q111 strains showed the highest inhibition to E. ictaluri by the double-layer agar methods. Finally, two Bacillus strains (Q16, Q111) were selected as a source of potential probiotic because of the ability of extracellular enzyme secretion (protease, amylase, cellulose) strong growth at 0,1-1% salt concentrations, survival within the pH range 6-8, resistance to low pH and low bile salts, inability to produce haemolysin enzyme, sensitivity to eight antibiotics in the three impacting groups (inhibition of wall synthesis, inhibition mechanism of protein synthesis, inhibition of nucleic acid synthesis). Two Bacillus strains (Q16, Q111) were identified that they belong to Bacillus subtilis by biochemical method and 16S rRNA gene sequencing method. This study indicated that two Bacillus strains (Q16, Q111) isolated from catfish pond can be applied as high potential probiotics that used to farm catfish.

The Role of TMPRSS2 and TMPRSS2- Inhibitors in Cell Entry Mechanism of COVID-19

The enzymes trypsin, furine and other proprotein convertases, cathepsin, transmembrane proteases (TMPRSS) and elastases play a role in the cell entry of coronaviruses (Coronaviridae). The proteases TMPRSS2 and TMPRSS11a, which are abundant in the respiratory tract and expressed on cell surfaces, promote the entry of SARS-CoV-1 viruses. For the TMPRSS protease TMPRSS11d - also known as human airway trypsin-like protease (HAT) - a proteolytic activation of the S- protein of SARS-CoV-1 was demonstrated. TMPRSS2, in turn, complexes with the ACE2 receptor, which allows efficient penetration of the virus directly at the cell surface. TMPRSS2 and TMPRSS11D activate the S protein by cleaving it into the S1 and S2 subunits, thus allowing endosome-independent cell entry at the cell membrane. Virus-based therapies include monoclonal antibodies, antiviral peptides that dock to the S protein of viruses, viral nucleic acid synthesis inhibitors and inhibitors for docking to other viral structures and accessory proteins.

CASE REPORT ON METRONIDAZOLE INDUCED RASH

Metronidazole is a synthetic nitroimidazole. It acts by disruption of DNA and inhibition of nucleic acid synthesis. Hypersensitivity reactions, including urticaria, pruritus, erythematous rash, and flushing have been reported; however, the frequency of reactions is not known. This is a case report of 7 year old female Child patient who was admitted in paediatric ward in King George Hospital, Visakhapatnam with a chief complaint of fever with vomiting and loose stools since 7 days. On the 2nd day of her treatment, she developed rashes and facial flushing associated with redness of face. Metronidazole was stopped after 3 days of appearance of these complaints so we suspect that it is a condition of metronidazole induced rash. Physician must suspect if such reactions occur during the treatment with metronidazole and must cautiously evaluate such drug-associated rashes.

Antimicrobial Drug Interactions: Systematic Evaluation of Protein and Nucleic Acid Synthesis Inhibitors.

Antimicrobial multidrug resistance and its transmission among strains are serious problems. Success rate is decreased and treatment options are narrowed due to increasing bacterial multidrug resistance. On the other hand, the need for long-term efforts to discover new antibiotics and difficulties finding new treatment protocols make this problem more complex. Combination therapy, especially with synergistic use of antimicrobials is a rational treatment option with huge benefits. Thus, screening antibiotic interactions is crucial for finding better treatment options. Clinicians currently use combinatorial antibiotic treatment as an effective treatment option. However, antibiotics can show synergistic or antagonistic interactions when used together. In our study, we aimed to investigate interactions of antibiotics with different mechanisms of action. Antibiotics, which act as protein synthesis inhibitors (P) and nucleic acid synthesis inhibitors (N) were used in our study. We tested 66 (PN), 15 (NN), and 55 (PP) drug pairs on the Escherichia coli strain. The Loewe additivity model was used and alpha scores were calculated for analysis of interactions of drug combinations. Drug interactions were categorized as synergistic or antagonistic. Accordingly, pairwise combinations of protein synthesis inhibitors (PP) showed stronger synergistic interactions than those of nucleic acid synthesis inhibitors (NN) and nucleic acid synthesis–protein synthesis inhibitors (PN). As a result, the importance of mechanisms of action of drugs is emphasized in the selection of synergistic drug combinations.

ANTIBACTERIAL ACTIVITY OF AKAR KUNING (ARCANGELISIA FLAVA) SECONDARY METABOLITES: MOLECULAR DOCKING APPROACH

Objectives: Akar kuning (Arcangelisia flava) was known to have various pharmacological activities including as antibacterial. Several Gram-positive and Gram-negative bacteria show response to akar kuning secondary metabolites, although the type of metabolites that inhibit the growth of each type of bacteria not yet known. This study aims to obtain the prediction of metabolites from akar kuning with the greatest antibacterial potential against various types of antibacterial receptors.Methods: Molecular docking was performed using Autodock Vina 1.1.2 on several secondary metabolites of akar kuning against active site of several antibacterial receptors that were known for many antibiotics including as cell wall, protein, nucleic acid synthesis inhibitors, and antimetabolites. The main parameter used was the free energy of binding as affinity marker.Results: The docking results show that among 11 metabolites studied, 6-hydroxyfibraurin, berberine, and fibleucin provided the lowest free energy of binding between 11 antibacterial receptors compared with natural substrates or inhibitors from each receptor. Interesting results show by berberine as inhibitor of protein synthesis with possibility of allosteric site discovery. Berberine also shows more than 75% similarity with natural substrate of cell wall inhibition receptor, indicating possible similar type of interaction.Conclusion: Overall, it seems that for the selected secondary metabolites of akar kuning, the main mechanism of action was the inhibition of protein and cell wall synthesis, which was shown by berberine.

PH plays a role in the mode of action of trimethoprim on Escherichia coli.

Metabolomics-based approaches were applied to understand interactions of trimethoprim with Escherichia coli K-12 at sub-minimum inhibitory concentrations (MIC≈0.2, 0.03 and 0.003 mg L-1). Trimethoprim inhibits dihydrofolate reductase and thereby is an indirect inhibitor of nucleic acid synthesis. Due to the basicity of trimethoprim, two pH levels (5 and 7) were selected which mimicked healthy urine pH. This also allowed investigation of the effect on bacterial metabolism when trimethoprim exists in different ionization states. UHPLC-MS was employed to detect trimethoprim molecules inside the bacterial cell and this showed that at pH 7 more of the drug was recovered compared to pH 5; this correlated with classical growth curve measurements. FT-IR spectroscopy was used to establish recovery of reproducible phenotypes under all 8 conditions (3 drug levels and control in 2 pH levels) and GC-MS was used to generate global metabolic profiles. In addition to finding direct mode-of-action effects where nucleotides were decreased at pH 7 with increasing trimethoprim levels, off-target pH-related effects were observed for many amino acids. Additionally, stress-related effects were observed where the osmoprotectant trehalose was higher at increased antibiotic levels at pH 7. This correlated with glucose and fructose consumption and increase in pyruvate-related products as well as lactate and alanine. Alanine is a known regulator of sugar metabolism and this increase may be to enhance sugar consumption and thus trehalose production. These results provide a wider view of the action of trimethoprim. Metabolomics indicated alternative metabolism areas to be investigated to further understand the off-target effects of trimethoprim.

Phenotypic and Genotypic Characterization of Some Pseudomonas sp. Associated with Burkholderia cepacia Isolated from Various Infected Fishes

This study aims to characterize Pseudomonas species that had been isolated from various naturally diseased fresh and marine water fishes, Nile tilapia, catfish, gilt-head bream, and Sea bass using phenotypic method, morphology and biochemistry characters using API 20NE, and genotypic method (16S rRNA gene sequencing) with some of the histopathological characteristics. Six of seven presumptive Pseudomonas sp. were successfully identified by API 20NE method to level species; they were identified as 2 P. fluorescens, one P. putida, one Pseudomonas sp and 3 Burkholderia cepacia while genotypically with 16S rRNA gene sequencing that proved successful for all the four pseudomonas isolates (three as P. fluorescens and one P. putida). The results of phylogenetic analysis placed the isolates in the genus Pseudomonas based on 99% homology. Challenged test revealed that, P. fluorescens and P. putida are to be classified as pathogenic for O. niloticus and they also exhibited clinical signs and mortality rates up to 70% and showed histopathological changes of both liver and kidney which lead to death. The antibiogram study showed that no significant differences between P. fluorescens and P. putida which had intrinsically high sensitivity to nucleic acid synthesis inhibitors such as ciprofloxacin, norfloxacin, gentamycin, gatifloxacin, lomefloxacin and kanamycin. This study concluded that good overall agreement between phenotypic and genotypic identification procedures was found for the isolates with some minor differences in biochemical and physiological characteristics were observed between P. fluorescens strains, while the genotypic differences were significant observed between P. fluorescens and P. putida isolated from various fishes.

Accidental Cymoxanil (TANOS) Pesticide Poisoning (Case Report)

Background: Pesticides are a group of chemicals used in agriculture in order to achieve higher and better-quality crops. The vast majority of these are synthetic substances whose effect on the human organism is unfavorable, even toxic. Methods: We provide a brief overview of available Slovak and world literature on these issues. In the next section, we deal with the case of a patient, whose leading symptoms were headache and behavioral changes. After excluding organic lesions, we made a diagnosis „per exclusionem“ and diagnosed cymoxanil poisoning. Conclusions: We consider the relatively low number of recorded poisonings to be a result of strict regulation of pesticide use. Original Articles 28 Clinical Social Work and Health Intervention Clinical Social Work and Health Intervention Vol. 7 No. 3 2016 Introduction Pesticides are chemicals used to protect vegetables against animal pests, fungi and weeds. These are organic or inorganic substances. They are applied as a spray, powder, granules or mordant. The most important pesticides are insecticide substances used for destroying insects; fungicides substances used to destroy harmful parasitic fungi; herbicide substances used for weed control; rodenticides substances used for destroying rodents1. (1) If one uses pesticides it is important to work with extreme caution. How to use them and health at work are regulated by provisions having the force of law2,3.(2-3) TANOS 50WG is a combined two-component fungicide to protect potatoes against potato blight and potato Alternaria leaf spot, tomatoes against potato blight; cucumbers and zucchini against cucumber Peronospora; vines against Peronospora. Active substance: cymoxanil 250g/kg + famoxadone 250g/kg. Formulated as: dispersible granule Mechanism of action: systemic and contact. Antracol Combi WP 76 is a combined two-component fungicide intended for plant care, with a spectrum of activity similar to the product TANOS 50WG. Active substance: propineb 70% + cymoxanil 6%. Formulated as: dispersible powder4. Characterization of cymoxanil: Chemical characterization: N-ethylaminocarbonyl-2-cyano-2-methoxyiminoacetamide. The substance belongs to the class of acylureas. It acts primarily in systemic, but partly also in contact, fashion on plants. The effects of cymoxanil in plants include inhibition of nucleic acid synthesis, reduction in the permeability of cell membranes, limiting respiration and disruption of serine, glycine and cysteine synthesis. This results in inhibition of mycelial growth, reduction of sporulation and spores germination5. Symptoms of cymoxanil poisoning are presented in Table 1. Case description A 50-year-old, otherwise healthy man was brought into the internal medicine emergency room with a headache lasting 4 days and body temperature up to 38 °C. Beside the headache he complained about dry mucous membranes of the mouth, loss of appetite, fatigue, increased sweating, also at night. Targeted questions specified that four days before admission, i.e. before symptoms started, he sprayed vegetables against fungi. He could not specify the product name. During the spraying he was exposed to direct sunlight and despite knowledge of safety he did not use any respirator. The symptoms started the next morning and persisted during the consultation with a doctor. Objective finding reads that the patient was obese (BMI 33), skin was sweaty, body temperature 36.5 °C, isocoric pupils in middle position, bulbs without nystagmus, injected conjunctiva. Overall, psychomotor restlessness was present. The patient was restless & fussed to find a relief position. Neither neurological focality nor laterality were observed. Signs of meningeal irritation were indicated. The laboratory tests showed neutrophilic leukocytosis, adequate coagulation parameters, a high level of C-reactive protein, a normal procalcitonin, slightly increased GMT activity (Table 2). CT scan of the brain + skull trauma program were indicated. The finding was negative. The condition was evaluated as susp. Meningitis. We indicated parenteral antibiotic therapy. We examined the eye-ground with age-appropriate findings. The patient was IV hydrated and orally hydrated at the same time. During hospitalization the body temperature repeatedly exceeded 38 °C, we took a blood culture but it was completed with negative results. 29 Original Articles Clinical Social Work and Health Intervention Vol. 7 No. 3 2016 Family members delivered packaging of the spraying used. It was a TANOS preparation (active substances: cymoxanil + famoxadone). From the available literature we found that symptoms may indicate a cymoxanil poisoning. Tests for focal infection were conducted. Echokg, dental and ENT findings were normal. The eyeground finding was negative. Hydration, antibiotic, anti-edematous (mannitol) and analgesic treatment continued. The patient‘s condition gradually improved. On the fifth day he was in good condition released to outpatient care.

Inhibition of nucleic acid biosynthesis makes little difference to formation of amphotericin B-tolerant persisters in Candida albicans biofilm.

Candida albicans persisters constitute a small subpopulation of biofilm cells and play a major role in recalcitrant chronic candidiasis; however, the mechanism underlying persister formation remains unclear. Persisters are often described as dormant, multidrug-tolerant, nongrowing cells. Persister cells are difficult to isolate and study not only due to their low levels in C. albicans biofilms but also due to their transient, reversible phenotype. In this study, we tried to induce persister formation by inducing C. albicans cells into a dormant state. C. albicans cells were pretreated with 5-fluorocytosine (planktonic cells, 0.8 μg ml(-1); biofilm cells, 1 μg ml(-1)) for 6 h at 37°C, which inhibits nucleic acid and protein synthesis. Biofilms and planktonic cultures of eight C. albicans strains were surveyed for persisters after amphotericin B treatment (100 μg ml(-1) for 24 h) and CFU assay. None of the planktonic cultures, with or without 5-fluorocytosine pretreatment, contained persisters. Persister cells were found in biofilms of all tested C. albicans strains, representing approximately 0.01 to 1.93% of the total population. However, the persister levels were not significantly increased in C. albicans biofilms pretreated with 5-fluorocytosine. These results suggest that inhibition of nucleic acid synthesis did not seem to increase the formation of amphotericin B-tolerant persisters in C. albicans biofilms.