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The development of natural antimicrobial agents has attracted long-term attention due to the increasing demand for food preservation. Papaya, a widely cultivated nutritious tropical fruit, has benzyl isothiocyanate (BITC) as one of the most important secondary metabolites in its seeds. And the antibacterial activity of BITC toward different strains and the main antibacterial pathway remain unclear. The current study focused on characterizing the antibacterial effect and exploring the major bacteriostatic pathway of BITC. BITC was shown to have a broad-spectrum antibacterial effect, with a minimum inhibitory concentration of 1 µL/mL for Escherichia coli, Bacillus subtilis, and Aspergillus niger, and 0.5 µL/mL for Salmonella enterica, Staphylococcus aureus, and Penicillium citrinum. Additionally, BITC was identified to affect the integrity of the biological oxidation system rather than the permeability or morphology of cell membranes. Furthermore, BITC was found not only to affect ATP production but also to hinder a series of important chemical reactions of the coenzymes involved in the transfer of hydrogen ions in the respiratory chain. The bacteriostatic pathway of BITC was shown to be implicated in an incomplete respiratory chain and the deregulation of the metabolism system. These results indicate the potential of BITC as a natural preservative in the food industry. PRACTICAL APPLICATION: BITC is present in papaya seeds and can be extracted and purified. Exploring its antibacterial activity and main action pathway may facilitate its application as a new bacteriostatic agent in food industry.

The aqueous and ethanolic leaves and seeds extract of M. oleifera varieties, ‘Jaffna’, ‘PKM-1’ (Periyakulam-1), ‘PKM-2’ (Periyakulam-2), ‘ODC’ and ‘Conventional’ were analyzed for their free radical scavenging effect on DPPH (2, 2-diphenyl-2-picryl hydrazyl) and ABTS (2, 2-azinobis,3-ethyl-benzothiazolin-6-sulfonic acid). The DPPH and ABTS activity (based on IC50 values) trend with leaves extract was: Conventional > ODC > PKM-2 > PKM-1 > Jaffna and Conventional > ODC > PKM-2 > PKM-1 > Jaffna respectively. Similarly, the DPPH and ABTS radical scavenging activities of seeds extract was: Conventional > ODC > PKM-2 > PKM-1 > Jaffna and Conventional > ODC > PKM-2 > PKM-1 > Jaffna respectively. The trend observed with total phenolic content (TPC) and total flavonoid content (TFC) values for both leaves and seeds extracts was: Jaffna > PKM-1 > PKM-2 > ODC > Conventional. The antibacterial activity (disc-diffusion method) of the aqueous and ethanolic leaves and seeds extracts of the five varieties on Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, and Staphylococcus aureus showed a similar trend: Jaffna > PKM-1 > PKM-2 > ODC > Conventional. A comparative assessment of the plant growth promoting potential of the leaves extracts on Stevia rebaudiana was also performed. The trend observed was: Jaffna > PKM-1 > PKM-2 > ODC > Conventional. Therefore, the comparative study reveals that ethanolic leaf and seed extracts of Jaffna variety possess strong antioxidant and antibacterial properties with a high TPC and TFC, as compared to the other varieties. It also exhibits a promising plant growth promoting activity. Thus, this variety can be explored further as a reliable source of natural bacteriostatic agent, antioxidants and plant growth enhancer.

Significance Scleral lenses have become an increasingly common treatment for ocular surface disease and irregular corneas. Multidose, preservative-free saline solutions are frequently used off-label to fill scleral lenses. Because the fluid resides over the ocular surface during lens wear, contaminated solutions may increase the risk of infectious complications. Purpose We sought to assess the viability of skin microorganisms and pathogens associated with keratitis once introduced into a multidose preservative-free saline (MDPFS) solution containing the bacteriostatic agent boric acid (PuriLens Plus; The Lifestyle Co., Inc., Freehold, NJ). Methods Eleven bacterial and one yeast isolate were each inoculated to three lots of MDPFS as well as to sterile normal saline for comparison. Microorganism concentrations were enumerated at baseline and days 1, 3, 7, 14, 21, and 28. Persistence of microorganism viability was compared between MDPFS lots and between MDPFS and normal saline for each organism. Results Duration of microorganism viability was ≥24 hours in MDPFS with no significant difference in the distribution of survival duration of microorganisms in MDPFS versus normal saline (P = .15). Candida albicans concentrations declined 14 days earlier in MDPFS, whereas concentrations of viable organisms in MDPFS remained within 1 log of baseline for the longest durations for Pseudomonas aeruginosa (7 days), Escherichia coli (14 days), and Achromobacter xylosoxidans (≥28 days). Gram-positive organism concentrations remained within 1 log of baseline for no more than 3 days. Mild lot-to-lot variation in organism concentrations was noted near the end points of viability. Bacteriostasis was demonstrated in that concentrations of all organisms remained at or below baseline levels throughout the 28-day period. Conclusions After microbial contamination, persistence of organism viability was similar in PuriLens and normal saline. Environmental gram-negative organisms, many of which can contribute to infectious keratitis, can persist for weeks once introduced into saline solutions.

The spread of antibiotic-resistance poses a great threat, making it a growing need to develop other antibacterial strategies and therapeutics. Recently, owing to their excellent physicochemical pro...

The widespread of carbapenem-resistant Acinetobacter baumannii (CRAB) is of great concern in clinical settings worldwide. It is urgent to develop new therapeutic agents against this pathogen. This study aimed to evaluate the therapeutic potentials of compound 62520, which has been previously identified as an inhibitor of the ompA promoter activity of A. baumannii, against CRAB isolates, both in vitro and in vivo. Compound 62520 was found to inhibit the ompA expression and biofilm formation in A. baumannii ATCC 17978 at sub-inhibitory concentrations in a dose-dependent manner. These inhibitory properties were also observed in clinical CRAB isolates belonging to sequence type (ST) 191. Additionally, compound 62520 exhibited a bacteriostatic activity against clinical clonal complex (CC) 208 CRAB isolates, including ST191, and ESKAPE pathogens. This bacteriostatic activity was not different between STs of CRAB isolates. Bacterial clearance was observed in mice infected with bioimaging A. baumannii strain 24 h after treatment with compound 62520. Compound 62520 was shown to significantly increase the survival rates of both immunocompetent and neutropenic mice infected with A. baumannii ATCC 17978. This compound also increased the survival rates of mice infected with clinical CRAB isolate. These results suggest that compound 62520 is a promising scaffold to develop a novel therapeutic agent against CRAB infections.

Combinations of phytochemical(s) and engineered nanoparticles have attracted immense research interest due to their superior antimicrobial effects against contaminations. Herein, a Pickering emulsion is developed with capsulized phytochemicals including borneol and citral (BC-Cap) stabilized by hydrophilic amine-functionalized silica nanoparticles (SiO2 ─NH2 NPs). The droplet sizes of Pickering emulsion were 5.2 ± 1.4 µm under the condition that the concentrations of SiO2 ─NH2 NPs ranged from 0.6 to 1.2 wt.%, and the emulsion showed desirable stability during storage at 40°C for 365 days. In addition, the antibacterial and antibiofilm activities of the Pickering emulsion were investigated. The antibacterial effect of BC-Cap increased by two- to fourfold compared with citral or borneol alone. Treatment of BC/BC-Cap for 4 h eliminated the formation of biofilms generated by Listeria monocytogenes (at 5/1.25 mg/ml; 2 × MIC concentration) and Pseudomonas aeruginosa (at 5/2.5 mg/ml; 2 × MIC concentration). Further mechanistic studies revealed that the antibiofilm effects of BC-Cap were attributed to its ability to increase the porosity and lytic effects on the cell membrane of bacteria. Findings from the current study support the antibacterial and antibiofilm effects of BC-Cap Pickering emulsion as a promising food additive. PRACTICAL APPLICATION: The Pickering emulsion has potential applications as bacteriostatic agent in packaging materials and general surface disinfectant. The combination of borneol and citral is stabilized by hydrophilic amine-functionalized silica nanoparticles (SiO2 ─NH2 NPs). With the synergistic effects of borneol and citral, the Pickering emulsion shows a promising elimination effect against the formation of biofilms produced by Listeria monocytogenes and Pseudomonas aeruginosa.

Treating post-surgical wound is one of the major challenges in the field of medical Science due to the several disadvantages posed by the antibiotics. The antimicrobial and Wound healing activity of metal based nanoparticles were well known, but the effects of carbon dot nanoparticles (C-Dots) are less explored. In the present study a wet chemical method for the synthesis of C-Dots from sucrose, glucose and fructose was developed and they were characterized by UV-Visible, Fluorescent spectroscopic techniques and the pharmaceutical applications such as antibacterial and the wound healing activities were evaluated. The study revealed that the C-Dots synthesized from Sucrose (SCD) and Glucose (GCD) showed potent antibacterial activity against both positive and negative bacterial strains at 12.5µl/ml (0.1 ± 0.003) and Fructose (FCD) at 50 µl/ml (0.1 ± 0.01) compared to the vehicle Control (0.61 ± 0.06). The wound healing of SCD (367.8 ± 15.2) was observed better than the Control (280.8 ± 10.72) and FCD (326.8 ± 9.41). GCD (166.8 ± 10.83) skin tissues indicated best healing as compared to FCD (135.8 ± 8.29), SCD (157.3 ± 16.97) and Control (135.8 ± 8.29). The results suggest that C-Dots applied topically possess wound healing activity and have potential applications as a bacteriostatic agent.

The effect of aqueous unmodified fullerene C60 dispersions (AFD) at a concentration of 5 mg/L on the total number and metabolic activity of heterotrophic river bacteroplankton was investigated. The stimulating effect of AFD on the number of bacterioplankton and on the activity of electron transport chains in its cells is shown. It is established that, in the presence of AFD, the bactericidal activity of antibiotics decreases. The stimulating effect of fullerene on the natural heterotrophic bacterioplankton, which we discovered, casts doubt on the expediency of using AFD as a bacteriostatic agent.

In general, potent non-ketolide versions of erythromycin possessed conformationally constricted two- or three-atom-length sidechains at 3-OH. Novel 14-membered non-ketolides possessing long spacers beyond three-atom length were evaluated for antibacterial activity. The most potent one is 34a, featuring a five-atom-length flexible linker from of a pyridine ring to the aglycone. Conversion of the pyridine of 34a to other aryl groups, changing the linker's length of 34a to longer or shorter ones, and variation of the linker flexibility to a rigid olefin or alkyne led to decreased antibacterial activity. The hybrids of macrolides and quinolones 28b, 31 and 34b possessing various sidechains, unlike their 15-membered counterparts, were ineffective compared to 34a. Similar to the marketed ketolide telithromycin, the non-ketolide 34a proved to be a time-dependent bactericidal agent, but it exhibited superior in vivo pharmacokinetic properties such as longer half-life, higher plasma concentration, lower clearance and shorter time to reach the highest drug concentration relative to telithromycin. Molecular docking suggested 34a might π - π interact with the bacterial ribosomal RNA base G2505Ec. This study suggested that the bacteriostatic agent erythromycin can be structurally modified to afford a new bactericidal chemotype that targets the ribosome and is superior to ciprofloxacin with regard to its minimum bactericidal concentration.

Streptococcus mutans plays an important role in the development of dental caries in humans by synthesizing adhesive insoluble glucans from sucrose by mutansucrase activity. To explore the anti-cariogenic characteristics of rubusoside (Ru), a natural sweetener component in Rubus suavissimus S. Lee (Rosaceae), we investigated the inhibitory effect of Ru against the activity of mutansucrase and the growth of Streptococcus mutans. Ru (50 mM) showed 97% inhibitory activity against 0.1 U/mL mutansucrase of S. mutans with 500 mM sucrose. It showed competitive inhibition with a Ki value of 1.1 ± 0.2 mM and IC50 of 2.3 mM. Its inhibition activity was due to hydrophobic and hydrogen bonding interactions based on molecular docking analysis. Ru inhibited the growth of S. mutans as a bacteriostatic agent, with MIC and MBC values of 6 mM and 8 mM, respectively. In addition, Ru showed synergistic anti-bacterial activity when it was combined with curcumin. Therefore, Ru is a natural anti-cariogenic agent with anti-mutansucrase activity and antimicrobial activity against S. mutans. Electronic Supplementary Material (ESM) The online version of this article (doi: 10.1007/s12257-018-0408-0) contains supplementary material, which is available to authorized users.

Litsea cubeba essential oil (LCEO) extracted from the fruit of the Litsea tree is a broad-spectrum bacteriostatic agent that has been used to treat ailments for thousands of years in China. The objective of our study was to assess the inhibitory effect of LCEO on Botrytis cinerea, a fungus that causes the putrification of fruits and vegetables. After being treated with 1.0% LCEO, the electrical conductivity of the fungal cells increased, and the contents of soluble reducing sugars and proteins slowly increased over treatment time. After being treated for 48 h with 1.0% LCEO, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images clearly showed damage to hyphae cells when compared with the normal growth of the control groups. Additional studies showed that the ergosterol content in the cell membrane significantly decreased with an increase in the LCEO concentration, and the electrophoretic bands of the proteins assayed using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis method significantly changed at different LCEO concentrations. LCEO damaged the cell membrane and changed the cell membrane permeability, leading to the changes in some components in the cytoplasm, such as soluble reducing sugars, proteins, and ergosterol. In general, the antimicrobial activity of LCEO is attributable to a unique pathway and involves a series of events both on the surface and within the cytoplasm of the fungal cell.

The rapid rise of antibiotic resistance causes an urgent need for new antimicrobial agents with unique and different mechanisms of action. The respiratory chain is one such target involved in the redox balance and energy metabolism. As a natural quinone compound isolated from the root of Salvia miltiorrhiza Bunge, cryptotanshinone (CT) has been previously demonstrated against a wide range of Gram-positive bacteria including multidrug-resistant pathogens. Although superoxide radicals induced by CT are proposed to play an important role in the antibacterial effect of this agent, its mechanism of action is still unclear. In this study, we have shown that CT is a bacteriostatic agent rather than a bactericidal agent. Metabolome analysis suggested that CT might act as an antibacterial agent targeting the cell membrane. CT did not cause severe damage to the bacterial membrane but rapidly dissipated membrane potential, implying that this compound could be a respiratory chain inhibitor. Oxygen consumption analysis in staphylococcal membrane vesicles implied that CT acted as respiratory chain inhibitor probably by targeting type II NADH:quinone dehydrogenase (NDH-2). Molecular docking study suggested that the compound would competitively inhibit the binding of quinone to NDH-2. Consistent with the hypothesis, the antimicrobial activity of CT was blocked by menaquinone, and the combination of CT with thioridazine but not 2-n-heptyl-4-hydroxyquinoline-N-oxide exerted synergistic activity against Staphylococcus aureus. Additionally, combinations of CT with other inhibitors targeting different components of the bacterial respiratory chain exhibit potent synergistic activities against S. aureus, suggesting a promising role in combination therapies.

In this study, a bilayer antibacterial chromogenic material has been prepared using chitosan (CS) and hydroxyethyl cellulose (HEC) as the inner substrates, mulberry anthocyanins (MA) as natural tracers, and titanium dioxide nanoparticles (nano-TiO2) as bacteriostatic agent for the outer layer. By investigating its apparent viscosity and suitability for three-dimensional (3D) printing, the optimal ratio of the substrates was determined to be CS:HEC = 3:3 (CH). The CH viscosity was observed to be moderate. The printing process was consistent with no breakage or clogging, and the printed image was of high stability, and not susceptible to collapse and diffusion. Scanning electron microscopy and infrared spectroscopy indicated that the intermolecular binding between the substances exhibited good compatibility. Nano-TiO2 was evenly distributed in the CH, and no agglomeration occurred. The inner membrane fill rates affected the overall performance of the chromogenic material, with strong inhibitory effects against Escherichia coli and Staphylococcus aureus at different temperatures, as well as strong color stability. The experimental results indicated that the double-layer antibacterial chromogenic material can, to a certain extent, extend the shelf life of litchi fruit and determine the extent of its freshness. Therefore, from this study, we can infer that the research and development of intelligent materials have a certain reference value.

Intestinal microbiota dysregulation is considered the primary trigger of low-grade inflammation responsible for weight loss due to heat stress. 1,8-Cineole is the major bacteriostatic agent in eucalypt and possesses remarkable anti-inflammatory properties. However, the mechanisms of its effect on intestinal microbiota remain unclear. In this study, 1,8-cineole was prepared into microcapsules prior to use as feed supplement in chickens. The microencapsulation efficiency and chemical stability of 1,8-cineole microcapsules were evaluated. The chicken treatment with 1,8-cineole microcapsules (1 or 3%) for 45 days, in the presence or absence of heat stress for fifteen days, commenced on Day 31, with or without an antibiotics mix (Abx) for three days on Day 27. Performance parameters were measured once a week from Day 30 through Day 45. Surface and entrapped concentration of 1,8-cineole was estimated as 7.89 g/100 g powder in the microcapsules. The time to maximal concentration (Tmax), terminal half-life (T1/2), and the area under plasma concentration-time curve (AUC0-t) of the encapsulated 1,8-cineole were higher than those of the nonencapsulated in treated chickens, although the maximal concentrations (Cmax) were similar. Chickens treated under higher temperatures with 1,8-cineole microcapsules exhibited lower levels of grade inflammation and higher body weight gain. Dietary 1,8-cineole microcapsules recovered the normal structure of upper ileum and altered the ratio of gut microbiota under heat stress and increased the ratio of Lactobacillus and Escherichia, whereas the proportion of Salmonella decreased based on 16S rRNA analysis of the upper ileum microbiota. In vitro, 1,8-cineole effectively inhibited the growth of Salmonella as demonstrated by inhibition zone assay. In summary, our findings elucidated the interaction between 1,8-cineole and intestinal microbiota as a new mechanism for the anti-heat stress effect of 1,8-cineole in preventing low-grade inflammation and weight loss. The results suggest that 1,8-cineole microcapsules may be a good feed supplement to protect against heat stress injury.

Ever since the introduction of calcium hydroxide in 1920, it has been widely used in dentistry. This is dueto the therapeutic properties of calcium hydroxide imparted by its high pH and dissociation to form ionsCa+2 and OH?. This makes it a remineralizing agent, a bactericidal or bacteriostatic agent based on the pHconcentration and also an anti-inflammatory agent. It is being applied for various purposes in dentistry likeintracanal medicament, pulp capping agent, root canal sealer, cavity liner, apexification, pulpotomy, canalswith exudate, perforation management and root resorption. This review article aims to describe in detail thevarious properties of calcium hydroxide and applications marking 100 years of its use in dentistry.

We report the synthesis and antimicrobial properties of a partially reduced dihydronathphthoquinone analogue of 2-methoxy, 5-acetoxy calamenene, extracted from Subergorgia reticulata. The growth of a pathogenic Vibrio harveyi strain was effectively controlled by the calamenene derivative 1 (Cala1) and its synthetic analog 2 (Cala2). Complete mortality of V. harveyi was observed with 2.5 and 0.5 µg mL−1 concentrations of Cala1 and Cala2, respectively. The metabolic assays demonstrated that Cala1 is a bacteriostatic agent while Cala2 showed bactericidal properties. It was confirmed that translocation of Cala2 into the cytoplasm does not induce any change to the integrity of the bacterial cell wall. The Cala2 induced damage to the genetic material of 70% of cells while genetic material of 91% of cells treated with Cala1 remained intact. The Cala2 is, therefore, proposed as a potential bactericidal compound against the aquaculture pathogen V. harveyi. The fact that the Cala2 exhibited minimal cytotoxicity to Artemia nauplii indicates its potential use as an antimicrobial agent for aquaculture operations.

Sulfadiazine (SDZ), a bacteriostatic agent, was hosted in a metal–organic framework, specifically in MIL-53(Al) and modified-zinc MIL-53(Al,Zn). Materials were characterized structural, and texturally. Both hosts loaded sulfadiazine but they were differenced regarding the release of sulfadiazine. The presence of zinc plays a significant role to the modulation of sulfadiazine–MOF interactions. Release of sulfadiazine from sulfadiazine@MOFs was monitored in vitro and ex vivo conditions. A kinetic release model is proposed for in vitro sulfadiazine release. Remarkably, the materials did not show cytotoxicity against eukaryote cells.

Methylene blue and proflavine are fluorescent dyes used to stain nucleic acid from the molecular level to the tissue level. Already clinically used for sentinel node mapping, detection of neuroendocrine tumors, methemoglobinemia, septic shock, ifosfamide-induced encephalopathy, and photodynamic inactivation of RNA viruses, the antimicrobial, anti-inflammatory, and antioxidant effect of methylene blue has been demonstrated in different in vitro and in vivo studies. Proflavine was used as a disinfectant and bacteriostatic agent against many gram-positive bacteria, as well as a urinary antiseptic involved in highlighting cell nuclei. At the tissue level, the anti-inflammatory effects of methylene blue protect against pulmonary, renal, cardiac, pancreatic, ischemic-reperfusion lesions, and fevers. First used for their antiseptic and antiviral activity, respectively, methylene blue and proflavine turned out to be excellent dyes for diagnostic and treatment purposes. In vitro and in vivo studies demonstrated that both dyes are efficient as perfusion and tissue tracers and permitted to evaluate the minimal efficient concentration in different species, as well as their pharmacokinetics and toxicity. This review aims to identify the optimal concentrations of methylene blue and proflavine that can be used for in vivo experiments to highlight the vascularization of the skin in the case of a perforasome (both as a tissue tracer and in vascular mapping), as well as their effects on tissues. This review is intended to be a comparative and critical presentation of the possible applications of methylene blue (MB) and proflavine (PRO) in the surgical field, and the relevant biomedical findings from specialized literature to date are discussed as well.

As a bacteriostatic agent, nitrite has been used in food preservation for centuries. When used in combination with antibiotics, nitrite is reported to work either cooperatively or antagonistically. However, the mechanism underlying these effects remains largely unknown. Here we show that nitrite mediates tolerance to aminoglycosides in both Gram-negative and Gram-positive bacteria, but has little interaction with other types of antibiotics. Nitrite directly and mainly inhibits cytochrome heme-copper oxidases (HCOs), and by doing so, the membrane potential is compromised, blocking uptake of aminoglycosides. In contrast, reduced respiration (oxygen consumption rate) resulting from nitrite inhibition is not critical for aminoglycoside tolerance. While our data indicate that nitrite is a promising antimicrobial agent targeting HCOs, cautions should be taken when used with other antibiotics, aminoglycosides in particular., Zhang et al. show that nitrite mediates bacterial tolerance to aminoglycosides without affecting other antibiotics. They find that nitrite inhibits cytochrome heme-copper oxidases, blocking bacterial uptake of aminoglycosides. This study suggests nitrite as a promising antimicrobial agent while discouraging its combined use with aminoglycosides.

Contains fulltext : 229215.pdf (Publisher’s version ) (Closed access) Following its introduction as an antituberculosis agent close to 75 years ago, the use of para-aminosalicylic acid (PAS) has been limited by gastrointestinal intolerance and multiple formulations were produced in attempts to reduce its occurrence. More recently, an enteric-coated, granular, slow-release PAS formulation (PASER) was introduced and is now in wide-spread use for the treatment of drug-resistant tuberculosis. The current PASER dosing regimen is based on recommendations derived from older studies using a variety of different PAS formulations and relegate PAS to a role as an exclusively bacteriostatic agent. However, there is ample evidence that if sufficiently high serum concentrations are reached, PAS can be bactericidal and that intolerance following once daily dosing, that aids the achievement of such concentrations, is no worse than that following intermittent daily dosing. In particular, prevention of resistance to companion drugs appears to be dependent on the size of the single dose, and hence the peak concentrations, and not on maintaining serum levels consistently above minimum inhibitory concentration. We present a narrative review of the development of PAS formulations, dosing practices, and published data regarding pharmacokinetics and pharmacodynamics and the relationship of PAS dosage to intolerance and efficacy. Our conclusions suggests that we are at present not using PAS to its maximum ability to contribute to regimen efficacy and protect companion drugs.

β-Acids, important part of hops extract, are consisted by three main homologues (co-lupulone, ad-lupulone and n-lupulone). To study the properties of β-acids homologues, co-lupulone monomer was obtained from hops extract. The structure was explored by Fourier transform infrared spectroscopy (FTIR), UV-Visible Spectrophotometer (UV–Vis), Mass Spectrometer (MS), Nuclear magnetic resonance hydrogen spectrometer(1HNMR) and single-crystal X-ray diffraction. Five β-acids samples with different contents (30%,50%,70%, 90% and 100%) of co-lupulone were prepared by recrystallization method. The antioxidant experiment results showed that there were significant differences of samples with different contents of co-lupulone. The experiment result of antibacterial indicated that all samples against gram-positive bacteria (S. aureus and B. subtilis) was better than gram-negative bacteria (E. coli and S. paratyphi B), especially had no effect on S. paratyphi B. Interestingly, it could be concluded that the sample with higher the content of co-lupulone would have better antibacterial performance; in which the minimum inhibitory concentration (MIC) of pure co-lupulone against the three strains was all 37.5 μg/ml, while the sample containing 30% co-lupulone was only 75.0 μg/ml. These finding suggest that β-acids with high content of co-lupulone could be more value as a high quality natural bacteriostatic agent, as well as contribute to the hop variety breeding.

In this study, surfactant assisted synthesis of zinc oxide nanostructures (ZnO NSs) by facile atmospheric microplasma electrochemical processes at room temperature have been reported. We have investigated the effect of ionic surfactants and nonionic fructose on the morphology of synthesized samples and their antibacterial activity against various bacterial pathogens. The samples were examined by scanning electron microscope (SEM), X-ray diffraction (XRD), Photoluminescence (PL) spectroscopy and Fourier Transform infrared (FTIR) Spectroscopy. We obtained nanosheets, nanodrums and nanoneedles using different type of surfactants. XRD spectra indicated ZnO nanomaterial with hexagonal phase. The antibacterial activity of the as synthesized samples against various bacteria of clinical interests was carried out by diffusion well method. The results showed the significant antibacterial activity against all bacterial strains. Thus, ZnO nanomaterial exhibited potential application as a bacteriostatic agent in the visible light and could be developed as antibacterial agent to control and prevent the spreading of bacterial infections.

In this study, the essential oil loading microcapsules (E-UMs) of the urushiol microcapsules (UMs) as shell material containing essential oil (EO) as core material were prepared by in-situ polymerization technology, where for the first time the E-UMs acted as bacteriostatic agent, for end use in long-term antibacterial coating. The results showed that high core content of EO in E-UMs was up to 30 wt%, release rate was less than 1.87% after 6 h at 100 °C and a char residue of 19 wt% at 400 °C after thermal degradation. The mean diameter of three saturations (Ω = 1, 2, 3) of E-UMs was about (15, 43 and 69) μm, respectively, and all E-UMs were spherical shape-like. Similarly, the diameter of UMs formed by concentrated urushiol was between 7 and 74 μm. The release of EO from E-UMs showed a sustained-release effect under different storage temperatures (25, 100 and 150 °C). Specifically, by adding low content of E-UMs (10 wt%), the functionalization of epoxy coatings loaded with E-UMs (E-UMs@ER) were obtained, and played an important role in inhibiting the proliferation of drug resistant Helicobacter pylori and resistant Staphylococcus aureus on the medium of the final coatings. The results of this article contributed to the foundation and application of urushiol microcapsules.

We sought to determine if clinical data validate the dogma that bactericidal antibiotics are more clinically effective than bacteriostatic agents. We performed a systematic literature review of published, randomized, controlled trials (RCTs) that compared a bacteriostatic agent to a bactericidal agent in the treatment of clinical, bacterial infections. Of 56 identified trials published since 1985, 49 found no significant difference in efficacy between bacteriostatic and bactericidal agents. In 6 trials it was found that the bacteriostatic agent was superior to the bactericidal agent in efficacy. Only 1 trial found that the bactericidal agent was superior; in that case, the inferiority of the static agent was explainable by underdosing of the drug based on pharmacokinetic–pharmacodynamic analysis. Thus, virtually all available data from high-quality, RCTs demonstrate no intrinsic superiority of bactericidal compared to bacteriostatic agents. Other drug characteristics such as optimal dosing, pharmacokinetics, and tissue penetration may be more important efficacy drivers.

The increasing occurrence of multidrug resistant bacteria causing bacteremia infection, constitutes a major health problem, difficult-to-treat bacteremia due to its ability to form biofilm. Buffalo milk lactoperoxidase (BMLpo) is effective and safe to use as bacteriostatic agent. The MIC of BMLpo and amikacin were used to evaluate the antibiofilm activity against resistant L. monocytogenes and S. typhi. Prophylactic effects of BMLpo against L. monocytogenes and S. typhi bacteremia in vivo have been tested and ELISA test used to evaluate serum cytokines. Significant antibiofilm activity of BMLpo observed against the highest biofilm producer isolates. Our results showed that the prophylactic effect of BMLpo in BALB/c mice bacteremic model. A significant clearance of L. monocytogenes and S. typhi, investigated in blood and different organs tissues in BMLpo-treated infected groups when compared to the non-treated groups. Further, analysis of serum cytokines levels revealed that BMLpo prophylaxis modulates their release in different way when it compared to the control. This study showed, BMLpo effects as an alternative antibiofilm agent to compact gram negative pathogens, and protects the host against bacteremia infection. Moreover, the BMLpo role as an immunomodulatory. These investigations indicated the BMLpo crucial role in the practical clinical applications.