Commercial Antibiotics Research Articles

High Antibacterial Activity and Selectivity of the Versatile Polysulfoniums that Combat Drug Resistance.

Sulfonium-ion-containing polymers exhibit significant potential benefits for various applications. An efficient strategy to synthesize a type of antibacterial sulfonium-ion-bearing polypeptoids via a combination of ring-opening polymerization and a post-polymerization functionalization with various functional epoxides is presented. A systematic investigation is further performed in order to explore the influence of the overall hydrophobic/hydrophilic balance on the antimicrobial activity and selectivity of the prepared polysulfoniums. Notably, those chlorepoxypropane-modified polysulfoniums with an optimized amphiphilic balance show higher selectivity toward both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, than to red blood cells. The polymers also show great efficiency in inhibiting S. aureus biofilm formations, as well as in further eradicating the mature biofilms. Remarkably, negligible antibacterial resistance and cross-resistance to commercial antibiotics is shown in these polymers. The polysulfoniums further show their potent in vivo antimicrobial efficacy in a multidrug-resistant S. aureus infection model that is developed on mouse skin. Similar to the antimicrobial peptides, the polysulfoniums are demonstrated to kill bacteria through membrane disruption. The obtained polypeptoid sulfoniums, with high selectivity and potent antibacterial property, are excellent candidates for antibacterial treatment and open up new possibilities for the preparation of a class of innovative antimicrobials.

Comparison of Different Herbal Additives on Immune Response and Growth Performance of Broiler Chickens

This experiment was conducted to compare the effects of four commercial herbal additives (Noviherb®, Bioessence®, Biostrong®, and Novigrow®), and a commercial antibiotic (virginiamycin) on growth performance, carcass yield, visceral organs weight, thyroid hormones, and humoral immune responses of broiler chickens. Nine hundred day-old Ross 308 male broiler chicks were reared in litter-covered floor cages and distributed into five experimental groups with six replicates of 30 birds. Five dietary treatments tested were diets supplemented with Noviherb®, Bioessence®, Biostrong® (each of them 100g/ton of diet), Novigrow® (1000g/ton of diet), and virginiamycin (100g/ton of diet) as a positive control. Feed intake, body weight, mortality, feed conversion ratio, European broiler index, and feed cost per kilogram of body weight were measured during the experiment. Antibody titers against sheep red blood cells (SRBC), immunoglobulin G, immunoglobulin M, and plasma concentrations of thyroxine (T4) and triiodothyronine (T3) were evaluated at the age of 42 days. Then, four birds per replicate were killed to determine the relative weight of carcass and organs. The GLM procedures of SAS software and Duncan’s multiple range test were applied to analyze data in a completely randomized design with five treatments and six replicates of 30 birds per each. The effects of herbal additives on productive traits feed cost per kilogram of body weight and relative weight of organs were not significant in comparison with antibiotic treatment. Dietary inclusion of Noviherb®, Biostrong®, and Novigrow® significantly decreased feed cost per kilogram of carcass compared with Bioessence® or antibiotic treatments (p<0.05). The titers of IgG in Noviherb® and virginiamycin were significantly higher (p<0.05) than in Biostrong® and Novigrow® fed groups. The plasma concentration of triiodothyronine was significantly decreased (p<0.05) by dietary inclusion of Noviherb® and Novigrow® compared to the antibiotic. In conclusion, all the evaluated herbal additives could act as a substitute for the growth-promoting antibiotic.

Antibacterial effects of mangrove ethanolic leaf extract against zoonotic fish pathogen Salmonella arizonae

The emergence of multiple drug-resistant pathogens, affecting aquaculture and public health, has put the spotlight on alternative medicine research. This study was conducted to evaluate the In vitro and In vivo antibacterial activity of mangrove ethanolic leaf extract (MLEE) against Salmonella arizonae isolated from Carassius auratus. In vitro, antimicrobial activity of 10 mangrove species and 13 commercial antibiotics were determined using the agar diffusion method. MLEE with the highest antimicrobial activity were subjected to qualitative phytochemical tests and bioassay experiments. In vivo antibacterial activity of MLEE was assessed using C. auratus intraperitoneally injected with S. arizonae. Results showed that Sonneratia alba has the highest antimicrobial activity against S. arizonae followed by Avicennia marina, A. officinalis, Sonneratia ovata, Rhizophora mucronata, Excoecaria agallocha, and Bruguiera cylindrica. However, bacterial isolate was resistant to A. rhumpiana, Scyphiphora hydrophyllacea, and Laguncularia racemosa. Interestingly, S. alba has comparable antimicrobial activity with amoxicillin, trimethoprim, novobiocin, and cefixime. The activity of S. alba could be attributed to the presence of flavonoids, saponin, sterols, tannin, and terpenoids. Moreover, S. alba has reduced and delayed the onset of goldfish mortality infected with S. arizonae. Based on these findings, the S. alba MLEE, is a potential antimicrobial resource against S. arizonae.

Efficiency of Basil Essential Oil Antimicrobial Agents under Different Shading Treatments and Harvest Times

The aim of this study was to determine the antimicrobial activity of essential oils obtained from sweet basil (Ocimum basilicum L. cv. ‘Genovese’) cultivated in the open field under different shading conditions (red, blue, and pearl nets with a shade index of 50% and full sunlight exposure (control plants)), harvested at different times. The antimicrobial activity of basil essential oils (BEOs) obtained from all samples was determined for four microorganisms, while determinations for an additional five microorganisms included samples from non-shaded plants, plants grown under red and pearl nets, and second harvest of plants grown under blue net. Basil essential oil exhibited antimicrobial activity surpassing the activity of relevant commercial antibiotics regardless of growing conditions in the case of B. cereus, K. pneumoniae and C. albicans, while superior antimicrobial activity was exhibited in the case of essential oils from plants grown under blue nets in the case of S. aureus, E. coli and P. vulgaris. The influence of the application of colored shading nets was highly significant (p < 0.01) in the cases of all analyzed microorganisms except C. albicans and P. aeruginosa, while the influence of harvest time was proven in the cases of all microorganisms except K. pneumoniae. ANOVA proved that antimicrobial activities are highly dependent on the methods of plant production, shading treatment, and harvest time. Obtained results are discussed in relation to previously determined composition and yield of essential oils from basil grown under shade nets and harvested in different periods.

Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

Optimization and production of antimicrobial compounds by Aspergillus flavus MTCC 13062 and its synergistic studies

The current study was focused on the antimicrobial activities of Aspergillus flavus MTCC 13062 strain isolated from solid waste dumping site, Hisar (INDIA) which showed remarkable inhibitory effect against the test organisms ( Streptococcus gordonii, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella enterica , Pseudomonas aeruginosa, Pseudomonas florescens and Candida albicans ). Response Surface Methodology (RSM) was performed to optimize the production of bioactive compounds by Aspergillus flavus MTCC 13062 which considerably increased the antimicrobial activity by 22%, 75% and 50% in E. coli , S. aureus and C. albicans, respectively at pH 7.5, temperature 28 °C and incubation period of 7 days. LC-MS was used to confirm the molecular weight and purity of the bioactive compound, while FTIR spectroscopy confirmed its structural characterization. Minimum inhibitory concentration (MIC) assay was carried out using dichloromethane extracts of Aspergillus flavus MTCC 13062 and results indicated MIC value as low as 25 μg/mL against S. aureus and E. coli while 50 μg/mL against C. albicans. Antifungal susceptibility test of Aspergillus flavus MTCC 13062 revealed that it was susceptible to Itraconazole, Fluconazole, Terbinafine, Kanamycin and Amphotericin B with zone of inhibition ranging from 10 to 24 mm . Furthermore, synergistic studies were carried out using commercial antibiotics in combination with the fungal extract and promising results were observed. We conclude that future implementation of the combinatorial results may help reduce the prescribed dosage of these antibiotics and thereby reducing the potential risks associated with the high doses of these harmful antibiotics. • A. flavus MTCC 13062 with antimicrobial potential was isolated from solid waste. • Optimization (RSM) yielded increase in antimicrobial activity by 1.1–1.7 fold. • Glycenopyrin (C 9 H 13 NO 5 ) identified as the bioactive compound using LC-MS analysis. • Purified extracts showed MIC values as 25 μg/mL against E. coli and S. aureus. • Synergism was observed on combining fungal extract with selected antibiotics.

Small Molecule-Capped Gold Nanoclusters for Curing Skin Infections.

With the long-term and extensive abuse of antibiotics, bacteria can mutate into multidrug-resistant (MDR) strains, resist the existing antibiotics, and escape the danger of being killed. MDR bacteria-caused skin infections are intractable and chronic, becoming one of the most significant and global public-health issues. Thus, the development of novel antimicrobial materials is urgently needed. Non-antibiotic small molecule-modified gold nanoclusters (AuNCs) have great potential as a substitute for commercial antibiotics. Still, their narrow antibacterial spectrum hinders their wide clinical applications. Herein, we report that 4,6-diamino-2-pyrimidinethiol (DAPT)-modified AuNCs (DAPT-AuNCs) can fight against Gram-negative and Gram-positive bacterial strains as well as their MDR counterparts. By modifying DAPT-AuNCs on nanofibrous films, we develop an antibiotic film as innovative dressings for curing incised wounds, which exhibits excellent therapeutic effects on wounds infected by MDR bacteria. Compared to the narrow-spectral one, the broad-spectral antibacterial activity of the DAPT-AuNCs-modified film is more suitable for preventing and treating skin infections caused by various kinds of unknown bacteria. Moreover, the antibacterial films display excellent biocompatibility, implying the great potential for clinical applications.

Atypically Modified Carbapenem Antibiotics Display Improved Antimycobacterial Activity in the Absence of β-Lactamase Inhibitors.

Commercial carbapenem antibiotics are being used to treat multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis. Like other β-lactams, carbapenems are irreversible inhibitors of serine d,d-transpeptidases involved in peptidoglycan biosynthesis. In addition to d,d-transpeptidases, mycobacteria also utilize nonhomologous cysteine l,d-transpeptidases (Ldts) to cross-link the stem peptides of peptidoglycan, and carbapenems form long-lived acyl-enzymes with Ldts. Commercial carbapenems are C2 modifications of a common scaffold. This study describes the synthesis of a series of atypical, C5α modifications of the carbapenem scaffold, microbiological evaluation against Mycobacterium tuberculosis (Mtb) and the nontuberculous mycobacterial species, Mycobacterium abscessus (Mab), as well as acylation of an important mycobacterial target Ldt, LdtMt2. In vitro evaluation of these C5α-modified carbapenems revealed compounds with standalone (i.e., in the absence of a β-lactamase inhibitor) minimum inhibitory concentrations (MICs) superior to meropenem-clavulanate for Mtb, and meropenem-avibactam for Mab. Time-kill kinetics assays showed better killing (2–4 log decrease) of Mtb and Mab with lower concentrations of compound 10a as compared to meropenem. Although susceptibility of clinical isolates to meropenem varied by nearly 100-fold, 10a maintained excellent activity against all Mtb and Mab strains. High resolution mass spectrometry revealed that 10a acylates LdtMt2 at a rate comparable to meropenem, but subsequently undergoes an unprecedented carbapenem fragmentation, leading to an acyl-enzyme with mass of Δm = +86 Da. Rationale for the divergence of the nonhydrolytic fragmentation of the LdtMt2 acyl-enzymes is proposed. The observed activity illustrates the potential of novel atypical carbapenems as prospective candidates for treatment of Mtb and Mab infections.

Effect of the Combination of Levofloxacin with Cationic Carbosilane Dendron and Peptide in the Prevention and Treatment of Staphylococcus aureus Biofilms.

Antibiotic resistance and biofilm-related infections, persistent in conventional antimicrobial treatment, are continuously increasing and represent a major health problem worldwide. Therefore, the development of new effective treatments to prevent and treat biofilm-related infections represents a crucial challenge. Unfortunately, the extensive use of antibiotics has led to an increase of resistant bacteria with the subsequent loss of effectivity of commercial antibiotics, mainly due to antibiotic resistance and the ability of some bacteria to form microbial communities in biotic or abiotic surfaces (biofilms). In some cases, these biofilms are resistant to high concentrations of antibiotics that lead to treatment failure and recurrence of the associated infections. In the fight against microbial resistance, the combination of traditional antibiotics with new compounds (combination therapy) is an alternative that is becoming more extensive in the medical field. In this work, we studied the cooperative effects between levofloxacin, an approved antibiotic, and peptides or cationic dendritic molecules, compounds that are emerging as a feasible solution to overcome the problem of microbial resistance caused by pathogenic biofilms. We studied a new therapeutic approach that involves the use of levofloxacin in combination with a cationic carbosilane dendron, called MalG2(SNHMe2Cl)4, or a synthetic cell-penetrating peptide, called gH625, conjugated to the aforementioned dendron. To carry out the study, we used two combinations (1) levofloxacin/dendron and (2) levofloxacin/dendron-peptide nanoconjugate. The results showed the synergistic effect of the combination therapy to treat Staphylococcus aureus biofilms. In addition, we generated a fluorescein labeled peptide that allowed us to observe the conjugate (dendron-peptide) localization throughout the bacterial biofilm by confocal laser scanning microscopy.

Prevalence, Sensitivity Profile and Resistance of Gram-Positive Bacteria in Wounds to Conventional Antibiotics

Aim: The prevalence, sensitivity profile and resistance of Gram-positive bacteria in wounds to commercial antibiotics were ascertained in this study.
 Place and duration of study: University of Medical Sciences Teaching Hospital, Akure, Nigeria, between January and June 2019.
 Methodology: Wound swabs sample collection, isolation of bacteria, identification of Gram-positive bacteria isolates and antibiotics sensitivity testing of isolated bacteria were determined employing standard protocols.
 Result: Three Gram-positive bacteria were isolated and presumptively identified to be S. aureus, S. epidermidis and S. pyogenes. S. aureus had the highest prevalence of 53% followed by S. epidermidis with 42% and S. pyogenes accounting for the least occurrence of 5%. Ninety percent (90%) of ten S. aureus strains were resistant to ciprofloxacin while only 10% had intermediate activity. The least resistance of S. aureus strains was against pefloxacin (40%), while to streptomycin, 87.5% of eight S. epidermidis strains were resistant and 12.5% had intermediate sensitivity. Susceptibility was observed in S. epidermidis against pefloxacin (12.5%) while 50% had intermediate sensitivity and 37.5% were resistant. The highest zone of inhibition of S. epidermidis was observed in strain 7 against pefloxacin (16.00±1.00 mm) and in S. aureus by strain 5 against pefloxacin (16.50±2.50 mm).
 Conclusion: Pefloxacin-sensitive Staphylococcus and Streptococcus species from wound swabs could become resistant overtime and this calls for incessant vigilance on Gram-positive wound bacteria antibiotic-susceptibility appraisal particularly in an antibiotics-abuse setting.

Formulation of Insect Chitosan Stabilized Silver Nanoparticles with Propolis Extract as Potent Antimicrobial and Wound Healing Composites

Skin wounds are frequently influenced with microbial infections and inflammation, which need innovative agents for disputing them. Chitosan (Csn) was extracted from larvae of BSF “black soldier fly, Hermetia illucens” and ethanolic propolis extract (Pro) was employed for synthesizing silver nanoparticles (Ag-NPs), using facile biogenic protocol. The BSF-Csn was acquired with a yield of 1.56%, 91.3% deacetylation degree, and 88.600 Dalton molecular weight. The Ag-NPs were effectually biosynthesized using Pro, with a mean diameter of 8.73 nm and zeta potential of -21.34 mV. The antimicrobial activities assessment of insect Csn, Pro, synthesized Ag-NPs with Pro, and their composite against skin pathogens (Staphylococcus aureus and Candida albicans) revealed the elevated efficiency of the individual agents and the superior action of their composite (Csn/Pro/Ag-NPs), with 26.3 and 23.4 mm inhibition zones and inhibitory concentrations of 35.0 and 45.0 μg/mL from the composite toward S. aureus and C. albicans, respectively, which exceeded the actions of commercial antibiotics. The treatment of rat’s wounds with this composite promisingly led to faster healing of wounds and absence of inflammation and infection signs. The powerful actions of Csn/Pro/Ag-NPs as antimicrobial and wound healing composite strongly advocate their applications for skin protection, disinfection, and regeneration.

SCREENING OF SELECTED MALAYSIAN HERBS AS THE POTENTIAL BROAD SPECTRUM ANTIMICROBIAL AGENT AGAINST BACTERIAL DISEASES OF FISH

The control of fish disease is mostly based on synthetic antimicrobial agents. Indiscriminate usage of antimicrobial agents has resulted in antibiotics resistance. Therefore, the present study aims to evaluate the potential antimicrobial properties of herbal plants as an alternative antimicrobial agent. The susceptibility of fish pathogens namely Bacillus sp., Enterococcus faecalis, Staphylococcus aureus, Streptococcus agalactiae, Aeromonas hydrophila, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Vibrio alginolyticus towards aqueous and methanolic extracts of Cosmos caudatus, Curcuma mangga, Justicia gendarussa, Piper betle and Zingiber zerumbet were assessed using the agar well diffusion, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The methanolic extracts were found active against all tested bacteria, compared to aqueous extracts. The best antibacterial activity was demonstrated by methanolic extract of P. betle, followed by Z. zerumbet, C. caudatus, C. mangga and J. gendarussa, with the lowest MIC and MBC values of 0.39 and 1.56 mg/mL, respectively. The methanolic extracts of P. betle and Z. zerumbet also had greater inhibitory effects than some of the commercial antibiotics, particularly tetracycline and erythromycin. Overall findings suggested that the methanolic extracts of P. betle and Z. zerumbet are potential to be developed as new antimicrobial agents to prevent fish bacterial diseases.

The antibacterial activity of Kasumba turate (Carthamus tintorius L.) against Salmonella pullorum and Escherichia coli as an alternative feed additive for poultry

Kasumba turate (Carthamus tinctorius Linn) is a kind of traditional plant which has been widely used by the people of South Sulawesi to cure measles disease and chicken pox. Kasumba turate contains flavonoid and volatile oil. Some compounds have activity potential as antibacterial. This research aimed to determine the antibacterial activity of kasumba turate against Salmonella pullorum and Escherichia coli bacteria. This study was conducted based on a completely randomized design with 4 treatments and 5 replications. The treatment consisted of PO (tetracycline as control), P1 (0.5% kasumba turate extract), P2 (0.75% kasumba turate extract), P3 (1% kasumba turate extract), and P4 (1.25% kasumba turate extract), respectively. The results of this study showed that kasumba turate extract could inhibit the Salmonella pullorum and Escherichia coli growth with an inhibition zone of approximately 11-19 mm. Increasing the level of kasumba turate extract up to 1.25% did not show any differences of inhibition zone compared to the lower levels, however, its effectivenss was significantly lower than commercial antibiotic as the positive control. It concluded that a low level of Kasumba turate extract (0.5%) showed inhibition activity on bacterial growth so that it could be used as an alternative to feed additive poultry.

Effect of Sunlight on the Efficacy of Commercial Antibiotics Used in Agriculture.

Antibiotic stewardship is of paramount importance to limit the emergence of antibiotic-resistant bacteria in not only hospital settings, but also in animal husbandry, aquaculture, and agricultural sectors. Currently, large quantities of antibiotics are applied to treat agricultural diseases like citrus greening disease (CGD). The two commonly used antibiotics approved for this purpose are streptomycin and oxytetracycline. Although investigations are ongoing to understand how efficient this process is to control the spread of CGD, to our knowledge, there have been no studies that evaluate the effect of environmental factors such as sunlight on the efficacy of the above-mentioned antibiotics. We conducted a simple disc-diffusion assay to study the efficacy of streptomycin and oxytetracycline after exposure to sunlight for 7- or 14-day periods using Escherichia coli and Bacillus subtilis as the representative strains of Gram-negative and Gram-positive organisms, respectively. Freshly prepared discs and discs stored in the dark for 7 or 14 days served as our controls. We show that the antibiotic potential of oxytetracycline exposed to sunlight dramatically decreases over the course of 14 days against both E. coli and B. subtilis. However, the effectiveness of streptomycin was only moderately impacted by sunlight. It is important to note that antibiotics that last longer in the environment may play a deleterious role in the rise and spread of antibiotic-resistant bacteria. Further studies are needed to substantively analyze the safety and efficacy of antibiotics used for broader environmental applications.

The Use of Lavender (Lavandula angustifolia) Essential Oil as an Additive to Drinking Water for Broiler Chickens and Its In Vitro Reaction with Enrofloxacin.

Simple SummaryEssential oils can stimulate the growth and functioning of the body, which translates into both chickens’ health and enhanced production parameters. Given the increasing restrictions imposed on poultry production in terms of food safety, it seems appropriate to look for the use of new, natural substances to be applied in poultry production. The article presents the results of the study of lavender essential oil in this context, with a particular focus on its antimicrobial and immunostimulatory properties. The purpose of the study was to determine the influence of lavender essential oil (added to drinking water at concentrations of 0.4 mL/L) on the production parameters and selected blood parameters in broiler chickens and to assess the lavender oil in vitro reaction combined with a commercial antibiotic, enrofloxacin, against Escherichia coli. The results of the experiment showed that the lavender essential oil exerts antimicrobial and antioxidant activity and it also showed a positive effect on the production results of broiler chickens.Biological activity of lavender essential oil is a property that can potentially find an application in poultry nutrition. Nowadays, the use of bioactive compounds is encouraged in many areas of industry and agriculture, since these substances have similar properties as withdrawn antibiotic growth promoters. Additionally, antibiotic resistance bacteria are one of the most important current threats to animal health. The purpose of the study was to determine the influence of lavender essential oil on the production parameters and blood parameters in broiler chickens and to assess the lavender oil’s in vitro reaction in a combination with enrofloxacin towards Escherichia coli. One-day-old non-sexed chicks (Ross 308) were divided into three experimental groups, each consisting of 100 individuals (five replicate of 20 boiler chicken each). The chickens in the control group received drinking water with no addition of lavender essential oil. In the experimental groups, lavender oil was added to the drinking water at a concentration of 0.4 mL/L, in the LEO1–42 from 1 to 42 days of age and the LEO22–42 group from the 22 to 42 days of age. The chickens’ body weight, feed consumption, water consumption, deaths and elimination due to health reasons were determined in the experiment. On day 42 of the chickens’ lives, blood samples were collected based on which selected parameters were identified. An in vitro experiment of lavender oil in combination with enrofloxacin was investigated with a checkerboard method. The results of the experiment showed the antimicrobial and antioxidant activity of lavender essential oil and its positive effect on the production results of broiler chickens. The study results proved that the addition of lavender oil positively impacted the chickens’ final body weight and feed conversion ratio (p < 0.01). No differences were observed between the groups for water consumption, death rate and the examined biochemical and immunological blood serum indices. Lavender essential oil was demonstrated to increase the blood serum’s total antioxidant status. A synergistic reaction in vitro was observed for lavender oil combined with enrofloxacin against resistant strains of Escherichia coli. Based on our study, a health-promoting effect of adding LEO to water for broiler chickens was found. Moreover, in vitro studies indicate a significant effect of lavender essential oil on the inhibition of the resistant strains of Escherichia coli growth and synergistic reaction with enrofloxacin.

Prenylated Flavonoids with Potential Antimicrobial Activity: Synthesis, Biological Activity, and In Silico Study.

Prenylated flavonoids are an important class of naturally occurring flavonoids with important biological activity, but their low abundance in nature limits their application in medicines. Here, we showed the hemisynthesis and the determination of various biological activities of seven prenylated flavonoids, named 7–13, with an emphasis on antimicrobial ones. Compounds 9, 11, and 12 showed inhibitory activity against human pathogenic fungi. Compounds 11, 12 (flavanones) and 13 (isoflavone) were the most active against clinical isolated Staphylococcus aureus MRSA, showing that structural requirements as prenylation at position C-6 or C-8 and OH at positions C-5, 7, and 4′ are key to the antibacterial activity. The combination of 11 or 12 with commercial antibiotics synergistically enhanced the antibacterial activity of vancomycin, ciprofloxacin, and methicillin in a factor of 10 to 100 times against drug-resistant bacteria. Compound 11 combined with ciprofloxacin was able to decrease the levels of ROS generated by ciprofloxacin. According to docking results of S enantiomer of 11 with ATP-binding cassette transporter showed the most favorable binding energy; however, more studies are needed to support this result.

Mechanism of action of various terpenes and phenylpropanoids against Escherichia coli and Staphylococcus aureus.

Foodborne, disease-causing microorganisms are increasingly resistant to commercial antibiotics. Thus, there is a need for the development of new agents capable of acting efficiently in the control of these pathogens. Terpenoids and phenylpropanoids stand out for having high biological activity and a broad spectrum of action. The objectives of this study were to evaluate the antibacterial potential of limonene, β-citronellol, carvone, carvacrol, eugenol and trans-cinnamaldehyde and to investigate the mechanism of activity of these compounds against the bacteria Escherichia coli and Staphylococcus aureus. The terpene and phenylpropanoid compoundswere purchased and their antibacterial potential was assessed by macrodilution. The mechanism of action was verified by tests of potassium ion efflux, salt tolerance, extravasation of cellular contents, absorption of crystal violet and morphological changes analyzed by electron microscopy. Bacteriostatic and bactericidal effects caused by the compounds carvone, carvacrol, eugenol and transcinemaldehyde were observed in both species; antibacterial activity against only S. aureus was observed for β-citronelol and limonene. Reduced salt tolerance was found for strains of E. coli treated with carvacrol and S. aureus treated with β-citronelol. There was extravasation of cellular materials induced by treatments with carvone, carvacrol, eugenol and trans-cinnamaldehyde in both microorganisms. The absorption of crystal violet increased for E. coli after incubation with each treatment. Deleterious effects and morphological changes were observed. Therefore, the monoterpenes and phenylpropanoids under study are potentially applicable for antimicrobial use against E. coli and S. aureus, and the mechanism of action involves changes in membrane permeability without cell lysis.

Study of Aerobic Agents that Causes Secondary Infection Associated with Atopic Dermatitis (Eczema) in an Affected Patients Admitted to Ramadi Teaching Hospital and Private Clinics in Ramadi City-Western of Iraq

Background : Atopic dermatitis or Atopic Eczema(AE) is a chronic, inflammatory skin disease which usually develops in early stage of life (childhood). In spite of the intensive investigations, the causes of Atopic Eczema still unclear, but are more likely to be multifactorial in nature. The interaction between environmental factors and genetic-factor seem to play a key role in the progression of disease. This study aimed to determine the prevalence of secondary bacterial infections associated with Eczema and the antibiograms of the most common bacterial isolates toward available commercial antibiotics. Patients and Methods: Swabs were taken from the affected patients with Eczema. Specimens were examined microscopically as soon as possible (within one hour) by direct Gram-stained smears and indirectly by cultivation aerobically using suitable culture media. Bacterial isolates were diagnosed and confirmed using suitable diagnostic techniques. The antibiotics susceptibility was determined by the Kirby Bauer Disc diffusion method and the results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines2018. Results: A total of 44 bacterial isolates were isolated from 55 patients affected with Eczema during a period from August to December 2019. Staphylococcus epidermidis took the first rank of isolation 18 (40.9%) fallowed by Staphylococcus aureus (14, 31.8%), Klebisella pneumonia (7, 15.9%), Pseudomonas aeruginosa (4, 9.1%) and Proteus spp (1, 2.3%). Conclusion: Gram-positive bacteria including Staphylococcus epidermidis and Staphylococcus aureusappeared to be the most bacterial agent that caused secondary bacterial infection with Eczema.

Extracellular metabolites of endophytic fungi from Azadirachta indica inhibit multidrug-resistant bacteria and phytopathogens.

Aim: To evaluate antimicrobial activity of extracellular metabolites (EMs) of endophytic fungal isolates (EFIs) from Azadirachta indica. Materials & methods: EFIs were identified by internal transcribed spacer (ITS) sequencing. Antimicrobial activity, and minimum inhibitor concentration(MIC) and minimum bactericidal concentration (MBC) were determined using agar diffusion and microdilution method, respectively. Results: Seventeen EFIs were isolated from different organs of A. indica. Eight of them were identified based on ITSsequencing. The EMs of EFIs inhibited the growth of six multidrug-resistant (MDR) bacterial superbugs and three phytopathogenic fungi. The MDR bacterial superbugs are resistant to six commercial antibiotics of different generations but susceptible to EMsof EFIs. The MIC (0.125-1.0μg/μl), MBC(0.5-4.0μg/μl) and minimum fungicidal concentration (1.0-4.0μg/μl) of the EMs from EFIs are lower enough. Conclusion: The EMs of the EFIs have promising antimicrobial activity against MDR bacteria and phytopathogenic fungi.

Wound Healing Potential of Polyherbal Formulation in Rats

Chronic wound infections are significant medical burden as the patients have to go through severe discomfort and distress. Invasion of various pathogenic microorganisms at the injured site further leads to damage of tissue which may results in resection of the organ. Appropriate wound healing is necessary to regain the functional and anatomical status of the damaged tissue that got disturbed due to wound. Conventional antibiotics used for the treatment of infections are associated with various drawbacks such as high cost and high incidence of resistance. Moreover, the dressing used for wounds are also unable to provide adequate moisture to the injured tissue. All these factors emphasise on the development of new advanced technologies for wound care. Polyherbal formulations, which comprise of various medicinal plant extracts, exhibit antioxidant and anti-inflammatory properties and can be much better alternative to commercial antibiotics for treatment of wound infections. In the present study, wound healing potential of “Septaheal” (a Polyherbal formulation) was evaluated in Wistar albino rats using incision, excision and burn wound models. The formulation exhibited wound healing property due to its angiogenic and mitogenic potential.