Use of the National Committee for Clinical Laboratory Standards guidelines for disk diffusion susceptibility testing in New York state laboratories

Aeromonas veronii tolC modulates its virulence and the immune response of freshwater pearl mussels, Hyriopsis cumingii

Aeromonas veronii is an opportunistic pathogen that causes diseases in aquatic animals, but its key virulence factors remain unclear. We screened the gene tolC with significantly different expression levels in the two isolates, A. veronii GL2 (higher virulence) and A. veronii FO1 (lower virulence). Therefore, we constructed mutant strain ΔtolC and analyzed its immunological properties. ΔtolC exhibited the reduced ability of biofilms formation, inhibited envelope stress response mediated by several antibiotics except cefuroxime, implying the ability to evade host immunity might be restrained. Challenge tests showed that the LD50 of ΔtolC was 10.89-fold than that of GL2. Enzymatic activities of ΔtolC group were significantly lower and peak time was delayed to 12 h, as demonstrated by qRT-PCR results. Histopathological examination displayed that the degree of tissue damage in ΔtolC group was alleviated. The results show that tolC is an important virulence factor of A. veronii, which provides references for live-attenuated vaccine.

Chemical Composition and Bioactivity of Dill Seed (Anethum graveolens L.) Essential Oil from Plants Grown under Shading

This study determined the content and composition of dill seed (Anethum graveolens L.) essential oil under varying light conditions: non-shaded plants in open fields and plants covered with pearl shade nets (40% shade index). Essential oil was extracted using Clevenger hydrodistillation. The essential oil content was 4.63% for non-shaded plants and 4.81% for shaded plants. GC/MS analysis revealed twenty-one and twenty-two components in dill seed from non-shaded and shaded plants, respectively. The terpenic fraction of essential oil from non-shaded plants consisted mainly of oxygen-containing monoterpene derivatives (53.6%), with carvone (46.1%) as the primary component, followed by monoterpene hydrocarbons (46.4%), predominantly limonene (43.8%). Essential oil from shaded plants contained a higher content of carvone (49.8%) and a lower content of limonene (37.8%) compared to essential oil from non-shaded plants. Non-shaded plant essential oil exhibited stronger antioxidant activity (EC50 value: 26.04 mg mL-1) than shaded plant essential oil (54.23 mg mL-1). Dill seed essential oil showed the most potent antimicrobial activity (disc diffusion method) against Escherichia coli (inhibition zone: 15-18 mm). Shaded plants demonstrated a positive influence of essential oil against Klebsiella pneumoniae. Carvone and its derivatives, as the main components, hold significant potential in the food industry and alternative medicines. A practical implication of this study could be higher plant densities or intercropping of dill, as it thrives with minimal light.

Process optimization for green synthesis of silver nanoparticles using Rubus discolor leaves extract and its biological activities against multi-drug resistant bacteria and cancer cells

Multi-drug resistant (MDR) bacteria are considered a serious public health threat. Also, increasing rate of resistance to anticancer drugs, as well as their toxicity, is another point of concern. Therefore, the new antibacterial and anticancer agents are always needed. The synthesizing silver nanoparticles (AgNPs) using medicinal plants, is an effective approach for developing novel antibacterial and anticancer agents. Rubus discolor, a native species of the Caucasus region, produces leaves that are typically discarded as a by-product of raspberry production. The present study has focused on optimizing the green synthesis of AgNPs using R. discolor leaves extract through response surface methodology. The optimal values for AgNPs synthesis were an AgNO3 concentration of 7.11 mM, a time of 17.83 h, a temperature of 56.51 °C, and an extract percentage of 29.22. The production of AgNPs was confirmed using UV-visible spectroscopy (λmax at 456.01 nm). TEM analysis revealed well-dispersed AgNPs (an average size of 37 nm). The XRD analysis confirmed the crystalline structure. The EDX detected a strong peak at 3 keV corresponded to Ag. The zeta potential value (- 44.2 mV) indicated the stability of nanoparticles. FT-IR spectra showed the presence of various functional groups from plant compounds, which play an important role in the capping and bio-reduction processes. The AgNPs revealed impressive antibacterial activities against MDR Escherichia coli and Pseudomonas aeruginosa (MIC ranging from 0.93 to 3.75 mg ml-1). The phytochemical analysis indicated the presence of phenolics, tannins, and flavonoids on the surface of AgNPs. They also showed significant cytotoxic effects on A431, MCF-7, and HepG2 cells (IC50 values ranging from 11 to 49.1 µg ml-l).

Development of thermosensitive hydrogel of Amphotericin-B and Lactoferrin combination-loaded PLGA-PEG-PEI nanoparticles for potential eradication of ocular fungal infections: In-vitro, ex-vivo and in-vivo studies

The most prevalent conditions among ocular surgery and COVID-19 patients are fungal eye infections, which may cause inflammation and dry eye, and may cause ocular morbidity. Amphotericin-B eye drops are commonly used in the treatment of ocular fungal infections. Lactoferrin is an iron-binding glycoprotein with broad-spectrum antimicrobial activity and is used for the treatment of dry eye, conjunctivitis, and ocular inflammation. However, poor aqueous stability and excessive nasolacrimal duct draining impede these agens' efficiency. The aim of this study was to examine the effect of Amphotericin-B, as an antifungal against Candida albicans, Fusarium, and Aspergillus flavus, and Lactoferrin, as an anti-inflammatory and anti-dry eye, when co-loaded in triblock polymers PLGA-PEG-PEI nanoparticles embedded in P188-P407 ophthalmic thermosensitive gel. The nanoparticles were prepared by a double emulsion solvent evaporation method. The optimized formula showed particle size (177.0 ± 0.3 nm), poly-dispersity index (0.011 ± 0.01), zeta-potential (31.9 ± 0.3 mV), and entrapment% (90.9 ± 0.5) with improved ex-vivo pharmacokinetic parameters and ex-vivo trans-corneal penetrability, compared with drug solution. Confocal laser scanning revealed valuable penetration of fluoro-labeled nanoparticles. Irritation tests (Draize Test), Atomic force microscopy, cell culture and animal tests including histopathological analysis revealed superiority of the nanoparticles in reducing signs of inflammation and eradication of fungal infection in rabbits, without causing any damage to rabbit eyeballs. The nanoparticles exhibited favorable pharmacodynamic features with sustained release profile, and is neither cytotoxic nor irritating in-vitro or in-vivo. The developed formulation might provide a new and safe nanotechnology for treating eye problems, like inflammation and fungal infections.

Usefulness of smear microscopy for therapeutic decision-making in patients with infectious keratitis

PURPOSE

To determine the usefulness of smears in the diagnosis of infectious keratitis by comparing smears and 2 different culture methods.

STUDY DESIGN

Retrospective, observational study.

METHODS

The foci of 73 patients diagnosed with infectious keratitis at Hiroshima University Hospital between July 2011 and September 2015 were abraded, and smear microscopy and culturing were performed. The microorganism detection rates and other parameters were compared.

RESULTS

Microorganisms were detected in 47 of 73 specimens. Microorganisms were identified in 32 of 69 cases cultured on plain medium (detection rate, 46.4%) compared with 22 of 61 cases cultured on swab transport medium (detection rate, 36.1%). There was no significant difference in the microbial detection rate between the plain medium method and the swab transport medium method (P = 0.23). Smear microscopy and culture findings were concordant in 21 (28.8%) cases, and different microorganisms were detected in 9 cases. In 17 cases, the culture was negative, despite the presence of microorganisms on smear microscopy, and in 7 cases, the culture was positive, despite the absence of microorganisms on smear microscopy. The positivity rate of microbial detection was significantly higher when no antimicrobial agents had been administered previously (odds ratio 7.50, P = 0.017).

CONCLUSION

Smear microscopy of abrasions from lesions is useful for the initiation of treatment for infectious keratitis. However, culture studies should be conducted at the same time to confirm antimicrobial sensitivity. If possible, smear microscopy should be performed before the initiation of antimicrobial therapy.

Fabrication, Characterization and Biomedical Evaluation of a Statistically Optimized Gelatin Scaffold Enriched with Co-Drugs Loaded into Controlled-Release Silica Nanoparticles

The current study focused on the fabrication of a well-designed, biocompatible, physically stable, non-irritating and highly porous gelatin scaffold loaded with controlled-release triamcinolone acetonide (TA) and econazole nitrate (EN) co-loaded into mesoporous silica nanoparticles (EN-TA-loaded MSNs) to provide a better long-lasting antifungal therapeutic effect with minimal unfavorable effects. Optimization of the MSNs-loaded scaffold was performed using central composite rotatable design (CCRD), where the effect of gelatin concentration (X1), plasticizer (X2) and freezing time (X3) on the entrapment of EN (Y1) and TA (Y2) and on the release of EN (Y3) and TA (Y4) from the scaffold were studied. The significant compatibility of all formulation ingredients with both drugs was established from XRD, DSC and FT-IR spectra analyses while SEM and zeta studies represented a very precise unvarying distribution of the loaded MSNs in the porous structure of the scaffold. The stability of the optimized scaffold was confirmed from zeta potential analysis (-16.20 mV), and it exhibited higher entrapment efficiency (94%) and the slower (34%) release of both drugs. During in vitro and in vivo antifungal studies against Candida albicans, the MSNs-loaded scaffold was comparatively superior in the eradication of fungal infections as a greater zone of inhibition was observed for the optimized scaffold (16.91 mm) as compared to the pure drugs suspension (14.10 mm). Similarly, the MSNs-loaded scaffold showed a decreased cytotoxicity because the cell survival rate in the scaffold presence was 89% while the cell survival rate was 85% in the case of the pure drugs, and the MSNs-loaded scaffold did not indicate any grade of erythema on the skin in comparison to the pure medicinal agents. Conclusively, the scaffold-loaded nanoparticles containing the combined therapy appear to possess a strong prospective for enhancing patients' adherence and therapy tolerance by yielding improved synergistic antifungal efficacy at a low dose with abridged toxicity and augmented wound-healing impact.

Antimicrobial, antioxidant activities, and total phenolic contents of Pycnanthus angolensis Sap and Cryptolepis sanguinolenta root extracts

The death of many people in tropical countries can be attributed to microbial infection, probably, because synthetic antibiotics are failing in the treatment of most microbial infections, attributed to the ability of the microorganisms to mutate and adapt to harsh conditions. This study evaluated, in vitro, the antimicrobial activities, antioxidant potentials, and the total phenolic as well as phytochemical contents of aqueous and ethanol extracts of the root of Cryptolepis sanguinolenta (Lindl.) and the crude sap of Pycnanthus angolensis (Welw) using selected standard bacteria strains (Staphylococcus aureus (ATCC 25,923), Staphylococcus saprophyticus (ATCC 15,305), Escherichia coli (ATCC 25,922), Salmonella typhi (ATCC 19,430), Pseudomonas aeruginosa (ATCC 27,853), and Proteus mirabilis (ATCC 49,565). The modified agar well diffusion method was used to evaluate the antimicrobial activities of the plant extracts. Chloramphenicol and tetracycline were used as positive controls. The extracts were screened for specific phytochemicals with total phenolic contents were determined using Folin Ciocalteu reagent test. The phytoconstituents observed were alkaloids, cardiac glycosides, and saponins in both Cryptolepis sanguinolenta and Pycnanthus angolensis. For the antimicrobial activities, all the test bacteria were susceptible to the crude sap of Pycnanthus angolensis except Proteus mirabilis. In the case of the Cryptolepis sanguinolenta, only S. aureus was susceptible to both aqueous and ethanol extracts. The total phenolic content, expressed in g/100 g GAE, recorded values of 55.427 ± 4.248 for the crude sap of Pycnanthus angolensis, and 11.642 ± 4.248 and 26.888 ± 4.248 for the aqueous and ethanol extracts of Cryptolepis sanguinolenta, respectively. It is concluded that Cryptolepis sanguinolenta and Pycnanthus angolensis are excellent candidates for further development of antimicrobial agents in the fight against microbial infections given the pressing need for novel efficacious agents.

Food wastes as a potential hotspot of antibiotic resistance: synergistic expression of multidrug resistance and ESBL genes confer antibiotic resistance to microbial communities

This study investigated antibiotic resistance (ABR) and extended-spectrum ß-lactamases (ESBL) patterns in bacterial isolates collected from the dairy, hotel, meat, and canteen food waste samples. A total of 144 bacterial strains were collected and screened for resistance against 9 standard antibiotics belonging to three generations and ESBL production. The ABR profile of the bacterial isolates was observed against all four major antibiotic groups (aminoglycosides, β-lactams, quinolone, and others), where resistance against cefotaxime (> 70%) and methicillin (> 50%) was high. Though the ABR pattern of strains from dairy waste (> 50%) was high against first-generation antibiotics, the strains from meat waste (> 50%) showed considerable resistance against second- and third-generation antibiotics. ESBL-producing isolates were screened (> 60%, n = 144) through primary identification tests (combined disk test and double disk synergy tests) and further confirmed through Hexa G-minus 23 and 24 and MIC E-stripe following CLSI guidelines. Genes conferring ESBL resistance bla_CTX-M, bla_SHV, bla_OXA, bla_TEM, bla_KPC genes and multidrug resistance (MDR) mexF gene were detected in the selected isolates with ABR and ESBL traits. Isolates with multidrug ABR and ESBL phenotype were further genotypically identified through 16 s rRNA gene sequencing. The synergy of ABR was detected through the co-expression of ESBL and MDR in isolates with a high occurrence of ABR and ESBL. The results demonstrate the significance of food waste as a natural reservoir of ABR and ESBL-producing pathogens, highlighting the importance of resistance monitoring and its interventions.

Cross-linked CMC/Gelatin bio-nanocomposite films with organoclay, red cabbage anthocyanins and pistacia leaves extract as active intelligent food packaging: colorimetric pH indication, antimicrobial/antioxidant properties, and shrimp spoilage tests

Multifunctional food packaging films were produced from crosslinked carboxymethyl cellulose/gelatin (CMC/Ge) bio-nanocomposites incorporated with Ge-montmorillonite (OM) nanofiller, anthocyanins (ATH) from red cabbage as colorimetric pH-indicator, and pistacia leaves extract (PE) as active agent. The influence of additives on the structural, physical, and functional properties of the films was investigated. The results showed that ATH and PE caused color alteration and reduced transparency. However, they improved the UV light barrier ability by 98 %, with less impact from OM, despite its well-dispersed state in the matrix. Increasing PE content in the bio-nanocomposite films caused an increase in compactness and surface roughness, reduction in moisture content (15.10-12.33 %), swelling index (354.55-264.58 %), surface wettability (contact angle 80.1-92.49°), water vapor permeability (7.37-5.69 × 10¹⁰ g m^-1s^-1Pa^-1), and nano-indentation mechanical parameters, without affecting the thermal stability. ATH-included films demonstrated color pH-sensitivity with improved ATH color stability through the ATH-Al³⁺ chelates formation. PE-added films exhibited effective antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, reaching 93 % of inhibition, and antimicrobial properties with biocidal effects for PE-rich film. The shrimp spoilage test showed that the T-1.5PE film offered the strongest active intelligent response. The CMC/Ge-based bio-nanocomposite films endowed with antioxidant/antimicrobial properties and colorimetric pH-sensitivity have promising potential for food packaging application.

Antibiotic resistance profiling and valorization of food waste streams to starter culture biomass and exopolysaccharides through fed-batch fermentations

The present study evaluated antibiotic resistance (ABR) in bacteria isolated from different food wastes viz., meat slaughterhouses, dairy and restaurants. About 120 strains isolated from the food waste were subjected to ABR screening. More than 50% of all the strains were resistant to Vancomycin, Neomycin and Methicilin, which belong to third-generation antibiotics. Two lactic acid bacteria (LAB) free of ABR were chosen to be used as starter cultures in media formulated from food waste. Food waste combination (FWC-4) was found to be on par with the nutrient broth in biomass production. The non-ABR LAB strains showed excellent probiotic properties, and in the fed-batch fermentation process, adding a nitrogen source (soya protein) enhanced the microbial biomass (3.7 g/l). Additionally, exopolysaccharide production was found to be 2.3 g/l. This study highlights the ABR incidence in food waste medium and its economic advantage for starter culture biomass production.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01222-9.

Comparative Bioactivity Evaluation of Chemically Characterized Essential Oils Obtained from Different Aerial Parts of Eucalyptus gunnii Hook. f. (Myrtaceae)

Essential oils (EOs) obtained by hydro-distillation from different parts of twigs (EOT), leaves (EOL), and fruits (EOF) of Eucalyptus gunnii Hook. f. were screened for their chemical composition, insecticidal, repellence, and antibacterial properties. Based on GC and GC/MS analysis, 23 constituents were identified across the twigs, leaves, and fruits, with 23, 23, and 21 components, respectively. The primary significant class was oxygenated monoterpenes (82.2–95.5%). The main components were 1,8-cineole (65.6–86.1%), α-terpinyl acetate (2.5–7.6%), o-cymene (3.3–7.5%), and α-terpineol (3.3–3.5%). All three EOs exhibited moderate antibacterial activities. EOL was found to have higher antibacterial activity against all tested strains except Dickeya solani (CFBP 8199), for which EOT showed more potency. Globally, Dickeya solani (CFBP 8199) was the most sensitive (MIC ≤ 2 mg/mL), while the most resistant bacteria were Dickeya dadantii (CFBP 3855) and Pectobacterium carotovorum subsp. carotovorum (CFBP 5387). Fumigant, contact toxicity, and repellent bioassays showed different potential depending on plant extracts, particularly EOT and EOL as moderate repellents and EOT as a medium toxicant.

Diversity of enterobacterales in sediments of lagoons with fish farming activity and analysis of antibiotic resistance

The use of antibiotics in fish production can induce bacterial populations to develop resistance to multiple antibiotics and transfer antibiotic resistance genes to other bacteria, including clinically relevant bacteria. This study evaluated the diversity of Enterobacterales in sediment from lagoons with fish farming activity and analyzed antibiotic resistance in the central region of Peru. Sediment samples were collected from four fish-active ponds and transported to the laboratory for analysis. Bacterial diversity was analyzed using DNA sequencing and antibiotic resistance was tested using the disk diffusion method. The results showed variability of bacterial diversity in the ponds with fish farming activity. Simpson's index indicated that the Habascocha lagoon is the most diverse in bacterial species of the order Enterobacterales (0.8), but the least dominant. The Shannon-Wiener index revealed that it is the most diverse (2.93) and the Margalef index revealed that species richness in this lagoon is high (5.72). Similarity percentage analysis (SIMPER) allowed the identification of the main Enterobacterales with the highest percentage contribution in the frequencies of individuals. In general, the Enterobacterales species isolated showed multi-resistance to the antibiotics used and Escherichia coli was the most resistant.

Going Back in Time: Increasing Penicillin Susceptibility among Methicillin-Susceptible Staphylococcus aureus Osteoarticular Infections in Children

In the late 1940s to 1950s, Staphylococcus aureus isolates first-gained resistance to penicillin. Recently, some centers have described an increase in the proportion of methicillin susceptible S. aureus (MSSA) which are also susceptible to penicillin (PSSA). There are little data on the frequency of PSSA infections in children. We investigated the prevalence of penicillin susceptibility among pediatric MSSA acute hematogenous osteoarticular infection (OAI) isolates. MSSA OAI isolates were obtained through surveillance studies at Texas Children's and St. Louis Children's Hospitals from January 2011 to December 2019. All isolates underwent PCR for blaZ β-lactamase, PVL genes and agr group. All blaZ negative isolates then underwent penicillin MIC determination. blaZ negative isolates with penicillin MIC ≤ 0.125 μg/mL were considered PSSA. Multilocus sequence typing (MLST) was conducted on a subset of isolates. A total of 329 unique isolates were included in the study. The median patient age was 9.2 years (IQR:5.1 to 12.2). Overall, 6.7% of isolates were penicillin susceptible. No PSSA were detected prior to 2015 but increased yearly thereafter. By the final study year, 20.4% of isolates were PSSA (P = 0.001). PSSA were similar to penicillin-resistant MSSA (PR-MSSA) isolates in terms agr group and PVL carriage as well as clinical presentation and outcomes. PSSA were of distinct sequence types compared to PR-MSSA. PSSA appears to be increasing among OAI in U.S. children. Overall, PSSA isolates are associated with a similar clinical presentation as penicillin-resistant isolates. The potential for use of penicillin treatment in PSSA OAI warrants further study.

Antibiotic Susceptibility and Minimum Inhibitory Concentration for Stenotrophomonas maltophilia Ocular Infections

Stenotrophomonas maltophilia (S. maltophilia) is a Gram-negative, opportunistic pathogen that can lead to ocular infections, such as keratitis and endophthalmitis. The purpose of this study was to determine the antibiotic susceptibility and minimum inhibitory concentrations (MICs) of S. maltophilia isolates from ocular infections and to evaluate the differences in antibiotic MICs between keratitis and endophthalmitis isolates. The disc diffusion method revealed that S. maltophilia isolates exhibited 91% susceptibility to levofloxacin and moxifloxacin and 61% susceptibility to trimethoprim−sulfamethoxazole (TMP−SMX). The E-test indicated that S. maltophilia isolates exhibited 40%, 100%, 72%, 91%, 91%, and 93% susceptibility to ceftazidime, tigecycline, TMP−SMX, levofloxacin, gatifloxacin, and moxifloxacin, respectively. The MIC90 values of amikacin, ceftazidime, cefuroxime, tigecycline, TMP−SMX, levofloxacin, gatifloxacin, and moxifloxacin were >256, >256, >256, 3, >32, 1, 2, and 0.75 µg/mL, respectively. The geometric mean MICs of ceftazidime, TMP−SMX, levofloxacin, gatifloxacin, and moxifloxacin were significantly lower for the keratitis isolates than for the endophthalmitis isolates (p = 0.0047, 0.003, 0.0029, 0.0003, and 0.0004, respectively). Fluoroquinolones showed higher susceptibility and lower MICs for the S. maltophilia isolates when compared with other antibiotics. Fluoroquinolones can be recommended for treating S. maltophilia ocular infections. Tigecycline and TMP−SMX could be alternative antibiotics for S. maltophilia ocular infections.

M, Fatima A, Mahdi YK, Abdullah NH. Evaluation of Catechin Synergistic and Antibacterial Efficacy on Biofilm Formation and acrA Gene Expression of Uropathogenic E. coli Clinical Isolates

Uropathogenic Escherichia coli has a propensity to build biofilms to resist host defense and antimicrobials. Recurrent urinary tract infection (UTI) caused by multidrug-resistant, biofilm-forming E. coli is a significant public health problem. Consequently, searching for alternative medications has become essential. This study was undertaken to investigate the antibacterial, synergistic, and antibiofilm activities of catechin isolated from Canarium patentinervium Miq. against three E. coli ATCC reference strains (ATCC 25922, ATCC 8739, and ATCC 43895) and fifteen clinical isolates collected from UTI patients in Baghdad, Iraq. In addition, the expression of the biofilm-related gene, acrA, was evaluated with and without catechin treatment. Molecular docking was performed to evaluate the binding mode between catechin and the target protein using Autodock Vina 1.2.0 software. Catechin demonstrated significant bactericidal activity with a minimum inhibitory concentration (MIC) range of 1–2 mg/mL and a minimum bactericidal concentration (MBC) range of 2–4 mg/mL and strong synergy when combined with tetracycline at the MBC value. In addition, catechin substantially reduced E. coli biofilm by downregulating the acrA gene with a reduction percent ≥ 60%. In silico analysis revealed that catechin bound with high affinity (∆G = −8.2 kcal/mol) to AcrB protein (PDB-ID: 5ENT), one of the key AcrAB-TolC efflux pump proteins suggesting that catechin might inhibit the acrA gene indirectly by docking at the active site of AcrB protein.

Antimicrobial Activity of Essential Oils Evaluated In Vitro against Escherichia coli and Staphylococcus aureus

The spread of extended-spectrum β-lactamase-producing Escherichia coli and methicillin-resistant Staphylococcus aureus has caused a reduction in antibiotic effectiveness and an increase in mortality rates. Essential oils (EOs), known for their therapeutic efficacy, can be configured as novel broad-spectrum biocides. Accordingly, the bacteriostatic–bactericidal activity of Citrus Lemon (LEO), Pinus Sylvestris (PEO), Foeniculum Vulgaris (FEO), Ocimum Basilicum (BEO), Melissa Officinalis (MEO), Thymus Vulgaris (TEO), and Zingiber Officinalis Rosc. (GEO), at concentrations ranging from 1.25 to 40% (v/v), were tested in vitro against different E. coli and S. aureus strains using minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). The chemical compositions of the EOs were analyzed using GC/MS. The major components of all seven tested oils were limonene, α-pinene, anethole, estragole, citral, thymol, and zingiberene, respectively. We found that the bacteriostatic–bactericidal activity of the EOs was related to their chemotypes and concentrations, as well as the strain of the bacteria. A dose–effect correlation was found when testing GEO against S. aureus strains, whilst FEO was found to have no activity regardless of concentration. PEO, MEO, and BEO were found to have bactericidal effect with a MIC and MBC of 1.25% (v/v) against S. aureus strains, and LEO was found to have values of 1.25% (v/v) and 5% (v/v) against ATCC and clinical isolate, respectively. Interestingly, the antimicrobial activity of TEO was not related to oil concentration and the complete inhibition of growth across all E. coli and S. aureus was observed. Although preliminary, our data demonstrate the efficacy of EOs and pave the way for further investigations on their potential synergistic use with traditional drugs in the human and veterinary fields.

Asperopiperazines A and B: Antimicrobial and Cytotoxic Dipeptides from a Tunicate-Derived Fungus Aspergillus sp. DY001

Investigation of the cytotoxic fractions of the ethyl acetate extract of the fermentation broth of the tunicate-derived Aspergillus sp. DY001 afforded two new dipeptides, asperopiperazines A and B (1 and 2), along with the previously reported compounds (+)-citreoisocoumarin (3) and (−)-6,8-di-O-methylcitreoisocoumarin (4). Analyses of the 1D and 2D NMR spectroscopic data of the compounds supported their structural assignments. Asperopiperazine A (1) is a cyclic dipeptide of leucine and phenylalanine moieties, which are substituted with an N-methyl and an N-acetyl group, respectively. On the other hand, asperopiperazine B (2) is a cyclic dipeptide of proline and phenylalanine moieties with a hydroxyl group at C-2 of the proline part. The absolute configuration of the amino acid moieties in 1 and 2 were determined by Marfey’s analyses and DFT NMR chemical shift calculations, leading to their assignment as cyclo(l-NMe-Leu-l-NAc-Phe) and cyclo(d-6-OH-Pro-l-Phe), respectively. Asperopiperazines A and B displayed higher antimicrobial effects against Escherichia coli and Staphylococcus aureus than Candida albicans. Furthermore, compounds 1–4 displayed variable growth inhibitory effects towards HCT 116 and MDA-MB-231 cells, with asperopiperazine A as the most active one towards HCT 116.

GC/MS Analyses of the Essential Oils Obtained from Different Jatropha Species, Their Discrimination Using Chemometric Analysis and Assessment of Their Antibacterial and Anti-Biofilm Activities

The essential oils of Jatropha intigrimma, J. roseae and J. gossypifolia (Euphorbiaceae) were analyzed employing GC/MS (Gas Chromatography coupled with Mass Spectrometry) analyses. A total of 95 volatile constituents were identified from J. intigrimma, J. gossypifolia and J. roseae essential oils, accounting for 91.61, 90.12, and 86.24%, respectively. Chemometric analysis using principal component analysis (PCA) based on the obtained GC data revealed the formation of three discriminant clusters due to the placement of the three Jatropha species in three different quadrants, highlighting the dissimilarity between them. Heneicosane, phytol, nonacosane, silphiperfol-6-ene, copaborneol, hexatriacontane, octadecamethyl-cyclononasiloxane, 9,12,15-Octadecatrienoic acid, methyl ester and methyl linoleate constitute the key markers for their differentiation. In vitro antibacterial activities of the essential oils were investigated at doses of 10 mg/mL against the Gram-negative anaerobe Escherichia coli using the agar well diffusion method and broth microdilution test. J. gossypifolia essential oil showed the most potent antimicrobial activity, demonstrating the largest inhibition zone (11.90 mm) and the least minimum inhibitory concentration (2.50 mg/mL), followed by the essential oil of J. intigrimma. The essential oils were evaluated for their anti-adhesion properties against the Gram-negative E. coli biofilm using a modified method of biofilm inhibition spectrophotometric assay. J. intigrimma essential oil showed the most potent biofilm inhibitory activity, demonstrating the least minimum biofilm inhibitory concentration (MBIC) of 31.25 µg/mL. In silico molecular docking performed within the active center of E. coli adhesion protein FimH showed that heneicosane, followed by cubebol and methyl linoleate, displayed the best fitting score. Thus, it can be concluded that the essential oils of J. gossypifolia and J. intigrimma leaves represent promising sources for antibacterial drugs with antibiofilm potential.

Enhanced Antifungal and Wound Healing Efficacy of Statistically Optimized, Physicochemically Evaluated Econazole-Triamcinolone Loaded Silica Nanoparticles

Co-encapsulated econazole nitrate-triamcinolone acetonide loaded biocompatible, physically stable, and non-irritating mesoporous silica nanoparticles (EN-TA–loaded MSNs) were prepared and optimized by using a central composite rotatable design (CCRD) for providing better therapeutic efficacy against commonly prevailed resistant fungal infections. These drugs loaded MSNs can significantly overcome the deficiencies and problems like short duration of action, requirement of frequent administration, erythema, and burning sensation and irritation associated with conventional drug delivery systems. The stability of optimized drugs loaded MSNs prepared with 100 gm of oil at pH 5.6 with a stirring time of 2 h was confirmed from a zeta potential value of −25 mV. The remarkable compatibility of formulation ingredients was depicted by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) spectra while scanning electron microscopy (SEM) and size analysis represented a very fine size distribution of nanoparticles ranging from 450–600 nm. The CCRD clearly predicted that the optimized parameters of drugs loaded MSNs have better values of percentage yield (85%), EN release (68%), and TA release (70%). Compared to pure drugs, the decreased cytotoxicity of EN-TA–loaded MSNs was quite evident because they showed a cell survival rate of 90%, while in the case of pure drugs, the survival rate was 85%. During in vivo antifungal testing against Candida albicans performed on three different groups, each consisting of six rabbits, the EN-TA–loaded MSNs were relatively superior in eradicating the fungal infection as a single animal exhibited a positive culture test. Rapid recovery of fungal infection and a better therapeutic effect of EN-TA–loaded MSN were quite evident in wound healing and histopathology studies. Likewise, on the 14th day, a larger inhibitory zone was measured for optimized nanoparticles (15.90 mm) compared to the suspension of pure drugs (13.90 mm). In skin irritation studies, MSNs did not show a grade of erythema compared to pure drugs, which showed a four-fold grade of erythema. As a result, MSNs loaded with combination therapy seem to have the potential of improving patient compliance and tolerability by providing enhanced synergistic antifungal effectiveness at a reduced dose with accelerated wound healing and reduced toxicity of therapeutics.

Evaluation of anticandidal activities and phytochemical examination of extracts prepared from Vitex agnus-castus: a possible alternative in treating candidiasis infections

BACKGROUND

Candidiasis infection is associated with high morbidity and mortality. Fungicidal resistance of some commercially used fungicides ascended the need for a naturally effective alternative. The current study aimed to evaluate the fungicidal activity of Vitex agnus-castus extracts in vitro against some Candida species.

METHODS

The bioactive compounds contained in the crude and alcoholic extracts were compared, and the antioxidant activity was tested, as well. The phytochemical analysis was carried out by Fourier Transform-Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC/MS). The scavenger activity of the tested extracts was tested, as well. The anticandidal activity was tested to detect the effect of the tested extracts on the mycelial growth of Candida albicans, Candida krusei, Candida parapsilosis, Candia tropicalis, Candida famata, Candida rhodotorula, and Candida dublinesis. The minimum inhibitory concentrations were calculated for all reported activities. The Scanning Electron Microscopy (SEM) and the Transmission Electron Microscopy (TEM) were used to detect the morphological and ultrastructure response in some selected species.

RESULTS

FTIR and GC/MS revealed the existence of different bioactive chemical groups such as polyphenols, fatty acids, terpenes, terpenoids, steroids, aldehydes, alcohols, and esters, phytol which is a diterpene. DPPH results confirmed the antioxidant activity of all extracts where the methanolic extract was the strongest scavenging substrate. All extracts showed strong inhibitory effects against different species at a concentration of 200 µg/ml (P < 0.001). SEM and TEM showed morphological and ultrastructure changes in C. famata.

CONCLUSION

The current study suggested a reliable antifungal activity of different extracts of Vitex agnus-castus against different Candida species and strains. However, further studies are required to confirm the safety of these extracts to be used in medical applications.

Phytochemical analysis, antioxidant, cytotoxic, and antimicrobial activities of golden chamomile (Matricaria aurea (Loefl.) Schultz Bip)

Matricaria aurea (Loefl.) Schultz Bip. (Asteraceae), known as golden chamomile, has been traditionally used for the treatment of various diseases. In this study, total phenolic, flavonoid, and tannin contents of total extract and different fractions of this plant were determined. The antioxidant, cytotoxic, and antimicrobial activities were also evaluated. Moreover, the phenolic profiles of selected fractions were determined by HPLC and LC-MS/MS analysis. Results demonstrated total phenolic contents of 37.8-57.2 mg GAE/g and total flavonoid contents of 3.0-111.2 mg QE/g. The ethyl acetate and methanol fractions (EF and MF) had the highest concentrations of phenolic, tannin, and flavonoid compounds. In both DPPH radical scavenging assay and phosphomolybdenum reduction assay, EF showed the best antioxidant activity, followed by MF. EF and MF indicated also the best antibacterial activities against Bacillus subtilis (MIC 1.56 and 12.5 mg ml^-1) and Staphylococcus aureus (MIC 0.78 and 12.5 mg ml^-1). Hexane fraction (HF) had no antibacterial effect. None of the samples had antifungal effect. MTT (3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay revealed for EF and HF the highest antiproliferative activities (IC₅₀ values ranged from 111.8 to 294.6 μg ml^-1). The presence of chlorogenic acid, ferulic acid, and luteolin-7-O-glucoside in MF, and p-coumaric acid in EF was confirmed and quantified.

Total Phenolic Content and Antioxidant and Antimicrobial Activities of Papaver rhoeas L. Organ Extracts Growing in Taounate Region, Morocco

The objective of this study is to valorize Papaver rhoeas L. from the Taounate region of Morocco by determining the total polyphenol content (TPC), the total flavonoid content (TFC) and the antioxidant and antimicrobial activities of four organs. The quantification of TPC and TFC in root, stem, leaf and flower extracts (RE, SE, LE and FE, respectively) was estimated by the Folin–Ciocalteu reaction and the aluminum trichloride method, respectively. Two tests were used to assess antioxidant power: the DPPH test and TAC assay. The antimicrobial activity was studied against five pathogenic bacteria and yeast, using two methods: disk diffusion and microdilution. The TPC in LE and LF was twice as high as that in RE and SE (24.24 and 22.10 mg GAE/g, respectively). The TFC values in the four extracts were very close and varied between 4.50 mg QE/g in the FE and 4.38 mg QE/g in the RE. The LE and FE showed low DPPH values with IC50 = 0.50 and 0.52 mg/mL, respectively. The TAC measurement revealed the presence of a significant amount of antioxidants in the studied extracts, mainly in LE and FE (6.60 and 5.53 mg AAE/g, respectively). The antimicrobial activity results revealed significant activity on almost all of the tested strains. The MIC of FE and SE against E. coli 57 was 1.56 and 0.78 mg/mL, respectively, while against the S. aureus it was 50 and 25 mg/mL, respectively. The low MLC value (1.56 mg/mL) was recorded against E. coli 57 by RE and SE.

Contribution to the Evaluation of Physicochemical Properties, Total Phenolic Content, Antioxidant Potential, and Antimicrobial Activity of Vinegar Commercialized in Morocco

Vinegar is a natural product widely used in food and traditional medicine thanks to its physicochemical properties and its richness in bioactive molecules. However, its direct use by consumers can have complications and undesirable effects. Therefore, this study contributes to investigating the physicochemical and biological properties of eleven vinegars marketed in Morocco. Determination of pH, acetic acid, conductivity, total soluble solids and alcohol content in vinegar was carried out. The polyphenols (TP), flavonoids (TF), and condensed tannins (CT) content was determined, and their antioxidant activities were evaluated using 2,2-diphenyl-1-picryl Hydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Phosphomolybdenum Reduction Assay (TAC). Then, the antimicrobial activity was studied against four pathogenic bacteria and two fungal strains, using the disk diffusion and the microdilution method. This study showed a wide range of acetic acid values from 0.65 ± 0.29 to 5.15 ± 0.20%. The high value of TP, TF, and CT in our samples V10, V9, and V4 was 655.00 ± 22.2 µgGAE/mL, 244.53 ± 11.32 µgQE/mL and 84.63 ± 1.00 µgTAE/mL, respectively. The tested strains showed variable sensitivities to the different samples with inhibition zones ranging from 6.33 ± 2.08 to 34.33 ± 0.58 mm. The lowest minimum inhibition concentrations were recorded against Staphylococcus aureus ATCC29213 ranging from 1.95 to 7.81 µL/mL. While Aspergillus niger ATCC16404 showed resistance against all of the analyzed samples. In general, vinegar commercialized in Morocco presents a variable range of products with variable properties. Indeed, must take into account this diversity when using it. A future study is needed to identify the phytochemical composition that will further the comprehension of this variability and contribute to its valorization.

Synthesis, characterization, in silico molecular docking, and antibacterial activities of some new nitrogen-heterocyclic analogues based on a p-phenolic unit

Compounds 6a and 6b (with pyrimidine moiety, amide linkage, and phenolic substrate) might be potent bacterial flavohemoglobin (flavoHB) inhibitors and they could set a promising starting point for future design of antibacterial agents.

Hemimycalins C-E; Cytotoxic and Antimicrobial Alkaloids with Hydantoin and 2-Iminoimidazolidin-4-one Backbones from the Red Sea Marine Sponge Hemimycale sp

In the course of our continuing efforts to identify bioactive secondary metabolites from Red Sea marine sponges, we have investigated the sponge Hemimycale sp. The cytotoxic fraction of the organic extract of the sponge afforded three new compounds, hemimycalins C–E (1–3). Their structural assignments were obtained via analyses of their one- and two-dimensional NMR spectra and HRESI mass spectrometry. Hemimycalin C was found to differ from the reported hydantoin compounds in the configuration of the olefinic moiety at C-5–C-6, while hemimycalins D and E were found to contain an 2-iminoimidazolidin-4-one moiety instead of the hydantoin moiety in previously reported compounds from the sponge. Hemimycalins C–E showed significant antimicrobial activity against Escherichia coli and Candida albicans and cytotoxic effects against colorectal carcinoma (HCT 116) and the triple-negative breast cancer (MDA-MB-231) cells.

Phytochemical analysis, antioxidant, antibacterial, and cytotoxic activities of leaves and roots of Rubus hyrcanus Juz

Rubus hyrcanus Juz. (Rosaceae), known as Caspian blackberry, is wildly distributed around the Caspian Sea. This study focused on antioxidant, cytotoxic, and antibacterial activities of total extracts and different fractions from the roots and leaves of this species. The total phenolics and flavonoid contents were also evaluated. Finally, the phenolic profiles of selected fractions were determined using HPLC–DAD and LC–MS/MS. The results indicated that the total phenolics content (TPC) of root total extract (RTE) was 3.5 times that of leaves (340.4 and 102.7 mg GAE/g, respectively). The TPC of three root fractions ranged from 226.6 to 392.9 mg GAE/g, while in leaves fractions, it ranged between 68.3 and 101.8 mg GAE/g. The total extract of leaves had higher contents of total flavonoids than roots (70.5 and 8.9 mg QE/g, respectively). The methanol fractions of both parts had the highest amounts of flavonoids. The root methanol fraction (RMF) had the best antioxidant effect in both DPPH radical scavenging assay (IC50: 9.16 μg ml−1) and total antioxidant capacity test (1010.5 mg ɑTE/g). The RMF and RTE had potent antibacterial activities against Bacillus subtilis and Staphylococcus aureus (MIC 1.5 mg ml−1). In the MTT assay, ethyl acetate fractions of roots and leaves exhibited the best cytotoxicity (IC50 247 and 227 μg ml−1, respectively) and the highest selectivity indexes (4.73 and 5.31, respectively). Phytochemical analysis revealed the presence of gallic acid, p-coumaric acid, and chlorogenic acid in leaves ethyl acetate fraction, chlorogenic acid in leaves methanol fraction, and gallic acid in the root ethyl acetate fraction.

The Impact of Apple Variety and the Production Methods on the Antibacterial Activity of Vinegar Samples

Apple vinegar is a natural product widely used in food and traditional medicine as it contains many bioactive compounds. The apple variety and production methods are two factors that play a major role in determining the quality of vinegar. Therefore, this study aims to determine the quality of apple vinegar samples from different varieties (Red Delicious, Gala, Golden Delicious, and Starking Delicious) prepared by three methods using small apple pieces, apple juice, and crushed apple, through determining the physicochemical properties and antibacterial activity of these samples. The antibacterial activity was studied against five pathogenic bacteria: Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli (ATB: 57), Escherichia coli (ATB: 97), and Pseudomonas aeruginosa, using two methods, disk diffusion and microdilution, for determining the minimum inhibitory concentrations and the minimum bactericidal concentrations. The results of this study showed that the lowest pH value was 3.6 for Stark Delicious, obtained by liquid fermentation, and the highest acetic acid values were 4.7 and 4% for the vinegar of Red Delicious and Golden Delicious, prepared by solid fermentation, respectively. The results of the antibacterial activity showed considerable activity of apple vinegar on the tested strains. Generally, the Staphylococcus aureus strain appears less sensitive and Pseudomonas aeruginosa seems to be very sensitive against all samples, while the other strains have distinct sensitivities depending on the variety studied and the method used. A higher antibacterial activity was found in vinegar obtained by the apple pieces method and the Red Delicious variety, with a low MIC and MBC recorded, at 1.95 and 3.90 µL/mL, respectively. This study has shown that the choice of both apple variety and production method is therefore an essential step in determining and aiming for the desired quality of apple vinegar.

Fusaripyridines A and B; Highly Oxygenated Antimicrobial Alkaloid Dimers Featuring an Unprecedented 1,4-Bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione Core from the Marine Fungus Fusarium sp. LY019

The fungal strain, Fusarium sp. LY019, was obtained from the Red Sea sponge Suberea mollis. Bioassay-directed partition of the antimicrobial fraction of the extract of the culture of the fungus provided two dimeric alkaloids, fusaripyridines A and B (1 and 2). The compounds possess a previously unreported moiety, 1,4-bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione. Further, the compounds display a highly oxygenated substitution pattern on the dihydropyridine moieties, representing an additional feature of the fusaripyridines. Fusaripyridines A and B are the first examples of natural products possessing 1,4-bis(2-hydroxy-1,2-dihydropyridin-2-yl)butane-2,3-dione backbone. Careful analyses of the one- and two-dimensional NMR and HRESIMS spectra of the compounds secured their structural mapping, while their absolute stereochemistry was established by analyses of their ECD spectra. The production of such dimeric alkaloids with an unprecedented moiety in the culture of Fusarium sp. LY019 supports further understanding of the biosynthetic competences of the cultured marine-derived fungi. Fusaripyridines A and B selectively inhibited the growth of Candida albicans with MIC values down to 8.0 µM, while they are moderately active against S. aureus, E. coli and HeLa cells.

Bioactivity evaluation for volatiles and water extract of commercialized star anise

Background

Usually, it takes about a year since the harvested fresh star anise fruit (SAF) reaches the market for consumer usage, all this time with different handling processes and different storage circumstances greatly affect its quality as well as its chemical composition and biological activity.

Aim

This study investigated the chemical constituents for volatiles and water extracts of commercialized SAF, as well as, their bioactivities.

Results

The chemical constituents were dominated by Trans-Anethole (47.16 %), estragole (14.4 %), and foeniculin (8.86 %) in the essential oils. Meanwhile, Coumarin, Apigenin, and Rosmarinic were the predominant phenolics of water extract. The result reflects a distinction of water extract to minimize mycotoxin secretion in liquid media. The SAF-volatiles were more effective in inhibiting microbial growth of the investigated bacterial and fungal strains.

Conclusion

Although samples were commercially collected from markets, their extracts were still capable to inhibit up to 55 % of fungal growth. The SAF water extract exhibited a moderate and selective cytotoxic effect (IC₅₀ = 114.9 μg/ml) against HepG2 cell lines compared to the low impact of essential oil (IC₅₀ = 513.8 μg/ml). Which led to the conclusion that despite the long-time span for SAF till it reaches the market, aqueous extract maintained a good ability for reducing mycotoxins-secretion from fungi grown in liquid media. This result emphasizes the role of the phenolics of water extracts' as an anti-mycotoxigenic agent.

Development of edible Thai rice film fortified with ginger extract using microwave-assisted extraction for oral antimicrobial properties

This study aimed to investigate microwave-assisted extraction (MAE) of dried ginger and to develop a rice-based edible film incorporating ginger extract. The optimal MAE conditions of 400 W microwave power and an extraction time of 1 min were determined using a 32 full factorial design. The optimized extract showed total phenolic compounds (TPC, 198.2 ± 0.7 mg gallic acid equivalent/g), antioxidant activity measured by DPPH (91.4 ± 0.6% inhibition), ABTS (106.4 ± 3.1 mg Trolox/g), and FRAP (304.6 ± 5.5 mg Trolox/g), and bioactive compounds including 6-gingerol (71.5 ± 3.6 mg/g), 6-shogaol (12.5 ± 1.0 mg/g), paradol (23.1 ± 1.1 mg/g), and zingerone (5.0 ± 0.3 mg/g). Crude extract of dried ginger showed antimicrobial activity against Streptococcus mutans DMST 18777, with a minimum inhibitory concentration and minimum bactericidal concentration of 0.5 and 31.2 mg/mL, respectively. The rice-based edible film incorporating 3.2% (w/v) ginger extract tested against S. mutans DMST 18777 had a mean zone of inhibition of 12.7 ± 0.1 mm. Four main phenolic compounds, 6-gingerol, 6-shogaol, paradol, and zingerone, and six volatile compounds, α-curcumene, α-zingiberene, γ-muurolene, α-farnesene, β-bisabolene, and β-sesquiphellandrene, were found in rice film fortified with crude ginger extract.

Antibiotic Susceptibility Profile of Pseudomonas aeruginosa Canine Isolates from a Multicentric Study in Romania

Treating infections caused by Pseudomonas aeruginosa is increasingly difficult due to high antibiotic resistance, materialized through the presence of multiple resistance strains, as well as due to rapid development of resistance throughout treatment. The present survey was conducted to investigate the antibiotic susceptibility profile of Pseudomonas aeruginosa pathogens in two University Veterinary hospitals from different geographical regions of Romania (i.e., Southwest Timișoara county and Northeast Iași county) involved in superficial canine infections. A total of 142 swab specimens were collected from dogs with superficial infections (superficial skin infections, otitis externa, and perianal abscess) to assess the presence of Pseudomonas aeruginosa, based on phenotypic and molecular characterization. According to their confirmed morphological and molecular features, 58 samples (40.84%; 58/142) were positive for Pseudomonas aeruginosa (according to their confirmed morphological and molecular features). Antibiotic susceptibility testing for 12 antibiotics was conducted using the Kirby–Bauer disc diffusion method. Drug resistance was observed in the case of all tested antibiotics. The susceptibility rate of P. aeruginosa strains that were tested in this study was in the following order: ceftazidime (53.44%; 31/58), followed by aztreonam (51.72%; 30/58), amikacin (44.82%; 26/58), azithromycin (41.37%; 24/58), gentamicin (37.93%; 22/58), cefepime (36.20%; 21/58), meropenem (25.86%; 13/58), piperacillin-tazobactam (25.86%; 13/58), imipenem (22.41%; 13/158), ciprofloxacin (17.24%; 10/58), tobramycin (8.62; 5/58), and polymyxin B (1.72; 1/58). The results highlight the importance of antibiotic susceptibility testing in Pseudomonas aeruginosa isolates from dogs with superficial infections to use an adequate treatment plan to manage the skin condition and other pathologies (otitis externa and perianal abscesses).

A plant endophyte Staphylococcus hominis strain MBL_AB63 produces a novel lantibiotic, homicorcin and a position one variant

Here we report a jute endophyte Staphylococcus hominis strain MBL_AB63 isolated from jute seeds which showed promising antimicrobial activity against Staphylococcus aureus SG511 when screening for antimicrobial substances. The whole genome sequence of this strain, annotated using BAGEL4 and antiSMASH 5.0 to predict the gene clusters for antimicrobial substances identified a novel antimicrobial peptide cluster that belongs to the class I lantibiotic group. The predicted lantibiotic (homicorcin) was found to be 82% similar to a reported peptide epicidin 280 having a difference of seven amino acids at several positions of the core peptide. Two distinct peaks obtained at close retention times from a RP-HPLC purified fraction have comparable antimicrobial activities and LC-MS revealed the molecular mass of these peaks to be 3046.5 and 3043.2 Da. The presence of an oxidoreductase (homO) similar to that of epicidin 280- associated eciO or epilancin 15X- associated elxO in the homicorcin gene cluster is predicted to be responsible for the reduction of the first dehydrated residue dehydroalanine (Dha) to 2-hydroxypropionate that causes an increase of 3 Da mass of homicorcin 1. Trypsin digestion of the core peptide and its variant followed by ESI-MS analysis suggests the presence of three ring structures, one in the N-terminal and other two interlocking rings at the C-terminal region that remain undigested. Homicorcin exerts bactericidal activity against susceptible cells by disrupting the integrity of the cytoplasmic membrane through pore formation as observed under FE-SEM.

Investigation of the antimicrobial activity and hematological pattern of nano-chitosan and its nano-copper composite

Novel synthesized Chitosan–Copper oxide nanocomposite (Cs–CuO) was prepared using pomegranate peels extract as green precipitating agents to improve the biological activity of Cs-NP's, which was synthesized through the ionic gelation method. The characterization of biogenic nanoparticles Cs-NP's and Cs–CuO-NP's was investigated structurally, morphologically to determine all the significant characters of those nanoparticles. Antimicrobial activity was tested for both Cs-NP's and Cs–CuO-NP's via minimum inhibition concentration and zone analysis against fungus, gram-positive and gram-negative. The antimicrobial test results showed high sensitivity of Cs–CuO-NP's to all microorganisms tested in a concentration less than 20,000 mg/L, while the sensitivity of Cs-NP's against all microorganisms under the test started from a concentration of 20,000–40,000 mg/L except for the C. albicans species. The hematological activity was also tested via measuring the RBCs, platelet count, and clotting time against healthy, diabetic, and hypercholesteremia blood samples. The measurement showed a decrease in RBCs and platelet count by adding Cs-NP’s or Cs–CuO-NP's to the three blood samples. Cs-NP's success in decreasing the clotting time for healthy and diabetic blood acting as a procoagulant agent while adding biogenic CuO-NP’s to Cs-NP’s increased clotting time considering as an anti-coagulant agent for hypercholesteremia blood samples.

Magnificines A and B, Antimicrobial Marine Alkaloids Featuring a Tetrahydrooxazolo[3,2-a]azepine-2,5(3H,6H)-dione Backbone from the Red Sea Sponge Negombata magnifica

Investigation of the Red Sea sponge Negombata magnifica gave two novel alkaloids, magnificines A and B (1 and 2) and a new β-ionone derivative, (±)-negombaionone (3), together with the known latrunculin B (4) and 16-epi-latrunculin B (5). The analysis of the NMR and HRESIMS spectra supported the planar structures and the relative configurations of the compounds. The absolute configurations of magnificines A and B were determined by the analysis of the predicted and experimental ECD spectra. Magnificines A and B possess a previously unreported tetrahydrooxazolo[3,2-a]azepine-2,5(3H,6H)-dione backbone and represent the first natural compounds in this class. (±)-Negombaionone is the first β-ionone of a sponge origin. Compounds 1-3 displayed selective activity against Escherichia coli in a disk diffusion assay with inhibition zones up to 22 mm at a concentration of 50 µg/disc and with MIC values down to 8.0 µM. Latrunculin B and 16-epi-latrunculin B inhibited the growth of HeLa cells with IC₅₀ values down to 1.4 µM.

Levels of Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Testosterone and Prolactin at Moderate Altitude Inhabitant Male

BACKGROUND AND OBJECTIVE

Male fertility depends on the availability of the potent androgen called testosterone. Testosterone production is regulated by the hypothalamic anterior pituitary axis. Two anterior pituitary hormones Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) are involved in spermatogenesis and testosterone production, respectively. Hypoxia, resulting from high altitude, may induce a change in these four hormones and may affect male fertility. This study was done to evaluate and compare the changes that occur in FSH, LH, testosterone and prolactin in males lived in moderate versus low altitude.

MATERIALS AND METHODS

This study was conducted on 300 individuals who were categorized based on the altitude of their habitat into two equal groups, namely: Inhabitants at moderate altitudes and inhabitants at low altitudes. A venous blood sample was collected from each individual to measure the levels of FSH, LH and prolactin.

RESULTS

Both LH and testosterone levels were significantly lower in high altitude inhabitants compared with low altitude inhabitants (p<0.01). The FSH level showed a significant statistical difference between two groups with a lower level in individuals living at high altitudes compared with low altitude inhabitants but on a value (p<0.05).

CONCLUSION

Moderate altitude hypoxia suppresses LH, FSH and testosterone levels as much as high altitude hypoxia does and these changes may depend on prolactin level.

Development of an enzyme-enhancer system to improve laccase biological activities

The present investigation reports an in-vitro study using combination of laccase and an enhancer capable of inhibiting the growth of pathogenic microorganisms, preventing biofilm formation, and whitening teeth. Laccase-cinnamic acid system remarkably inhibited the growth of Aggregatibacter actinomycetemcomitans, Candida albicans, S. aureus, and Streptococcus mutans whilst showed no significant effects on Gram-negative bacteria. Data presented that cinnamic acid (10 mM) with laccase (0.125 U ml^-1) led to a maximum decrease of about 90%, in S. mutans biofilm formation. The confocal laser scanning microscopy showed considerable detachment of S. mutans cells from glass substratum. The combined laccase-cinnamic acid system could remove teeth discoloration caused by coffee. SEM of the teeth surface exhibited no damages such as surface cracking or fracture. Liquid chromatography-tandem mass spectrometry (LC-MS) and cyclic voltammetry (CV) studies showed that laccase can catalyze the one-electron oxidation of cinnamic acid to the respective radical. This radical can then undergo several fates, including recombination with another radical to form a dimeric species, dismutation of the radical back to cinnamic acid or decarboxylation to give various reduced oxygen species. Therefore, the redox potential values of phenolic monomers/oligomers are related with their biological activities.

Oral microorganisms and bloodstream infection in allogeneic hematopoietic stem cell transplantation

OBJECTIVES

We aimed to compare oral and pathogenic microorganisms in bloodstream infections (BSIs) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We also investigated the relationship between BSIs and oral mucositis to identify the ratio of BSIs caused by oral microorganisms and the pathogenic microorganisms involved.

MATERIALS AND METHODS

We collected data on BSIs in 96 patients who underwent allo-HSCT in our institute between April 2009 and December 2019, including BSI pathogens isolated from blood cultures (BBSIs) and microorganisms isolated from washing the oral cavity with sterile distilled water. Oral microorganisms obtained at the onset of BSI (OBSIs) and during allo-HSCT (OSCTs) were defined as isolates collected during the week of blood culturing. Study entry was limited to samples collected up to 1 month after allo-HSCT without BSI. When the BBSI and OBSI were the same, we considered the oral microorganism to have caused the BSI.

RESULTS

The incidence rate of BSIs was 27%, and the predominant microorganism was coagulase-negative Staphylococci. Normal bacterial flora were decreased to 15.8% in OBSIs and 25.5% in OSCTs. The distribution of microorganisms without normal bacterial flora showed significant difference between BBSIs and OSCTs (p < 0.05). Oral mucositis was found in 72.9%, and BSI caused by oral microorganisms occurred in 46.2% of BSIs in allo-HSCT patients.

CONCLUSION

The distribution of microorganisms obtained from blood in patients with BSI during allo-HSCT was found to be similar to that of microorganisms from oral cultures.

CLINICAL RELEVANCE

Oral microorganism monitoring may be able to predict BSI during allo-HSCT.

Effect of nurse-led, goal-directed lung physiotherapy on prognosis of patients with sepsis caused by Acinetobacter baumannii pulmonary infection

OBJECTIVES

To investigate the role of nurse-led, goal-directed lung physiotherapy on the prognosis of patients with sepsis caused by Acinetobacter baumannii pulmonary infection.

METHODS

Patients with sepsis caused by A. baumannii pulmonary infection were recruited and divided into a control group (phase 1) and a treatment group (phase 2). Both groups received standard therapy for sepsis, and patients in phase 2 also received nurse-led, goal-directed lung physiotherapy. The primary outcome measure was 28-day mortality.

RESULTS

Among 742 patients with sepsis, 201 were diagnosed with A. baumannii pulmonary infection. Compared with patients in phase 1, patients in phase 2 had a significantly shorter duration of mechanical ventilation {median 4 (interquartile range (IQR) 3-5] vs 5 (IQR 3-12) days; P = 0.004}, lower intensive care unit (ICU) mortality [13.6% (18/132) vs 27.5% (19/69); P = 0.016] and lower 28-day mortality [21.2% (28/132) vs 37.7% (26/69); P = 0.012]. As a protective factor, nurse-led, goal-directed lung physiotherapy (odds ratio 0.341, 95% confidence interval 0.155-0.751; P = 0.008) was an independent risk factor for 28-day mortality.

CONCLUSIONS

Nurse-led, goal-directed lung physiotherapy shortened the duration of mechanical ventilation and ICU stay, and decreased ICU mortality and 28-day mortality in patients with sepsis caused by A. baumannii pulmonary infection.

The antibacterial and antihemolytic activities assessment of zinc oxide nanoparticles synthesized using plant extracts and gamma irradiation against the uro-pathogenic multidrug resistant Proteus vulgaris

In the case of Proteus vulgaris infection, the increased occurrence of multidrug-resistance strains has become a critical challenge in the treatment of urinary tract diseases. Therefore, using plant extracts as eco-friendly antibacterial provides an attractive solution to battle bacterial infection. The current study investigates the antibacterial and antihemolytic activity of nine medicinal plant extracts against P. vulgaris. Citrus limon extract at 150 µg/ml exhibited the highest antimicrobial action against P. vulgaris (the inhibition zone diameter; 22.7 mm). Zinc oxide nanoparticles (ZnO NPs) are synthesized using the plant extracts of C. limon, Allium sativum, Sonchus bulbosus, Allium cepa, and Asparagus racemosus. The antibacterial activity of ZnO NPs synthesized using C. limon extract at 150 µg/ml is significantly increased (33.8 mm). ZnO NPs synthesized using A. cepa, A. racemosus, and C. limon plant extracts are effectively protective for human red blood cells. The ZnO NPs synthesized using C. limon extract are characterized using UV-Visible spectroscopy, FTIR, XRD, and TEM. FTIR revealed that the plant extracts may serve as reducing and capping agents of ZnO NPs. XRD spectra confirmed the crystallinity of ZnO NPs. TEM image demonstrated the formation of spherical shapes of ZnO NPs with an average size of 37.05 nm. SEM of P. vulgaris cells treated with ZnO NPs showed cellular morphological damage compared to the untreated cells. ZnO NPs are synthesized by gamma irradiation as a clean and novel method. This study recommended the promising uses of the biosynthesized ZnO NPs using plant extracts as a natural, unique approach, to control the pathogenicity of P. vulgaris.

Synthesis, Characterization, Cyclic Voltammetry, and Biological Studies of Co(II), Ni(II), and Cu(II) Complexes of a Tridentate Schiff Base, 1-((E)-(2-Mercaptophenylimino) Methyl) Naphthalen-2-ol (H2L1)

A novel tridentate Schiff base, 1-((E)-(2-mercaptophenylimino) methyl) naphthalen-2-ol (H2L1), was synthesized by the condensation reaction of 2-hydroxy-1-naphthaldehyde with 2-aminothiophenol in absolute ethanol. The resulting ligand was reacted with Co(II), Ni(II), and Cu(II) ions to obtain tetrahedral CoL1, NiL1, and square planar CuL1 complexes. The Schiff base and its metal complexes were characterized using 1H-NMR, microanalysis, FT-IR, UV-visible, and mass spectroscopy (ESI-MS). All the compounds are soluble in DMSO and DMF. Spectroscopic studies show that the ligand coordinates to the metal center through the azomethine nitrogen, naphthoxide oxygen, and thiophenoxide sulfur to form a tridentate chelate system. Conductance measurements show that these compounds are molecular in solution. Cyclic voltammetry studies show Co(III)/Co(II) and Cu(II)/Cu(I) redox systems to be quasi-reversible involving a monoelectronic transfer while Ni(III)/Ni(II) was irreversible. In vitro antibacterial and antifungal activity against five bacterial strains (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, and Proteus mirabilis) and five fungal strains (Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, and Candida parapsilosis) showed no antifungal activity but moderate antibacterial activity on E. coli, S. aureus, P. aeruginosa, and P. mirabilis bacterial strains. Antioxidant studies reveal that the ligand and its Cu(II) complex are more potent than Co(II) and Ni(II) complexes to eliminate free radicals.

Pseudoceratonic Acid and Moloka'iamine Derivatives from the Red Sea Verongiid Sponge Pseudoceratina arabica

During an investigation of the chemistry of the Red Sea Verongiid sponge Pseudoceratina arabica, we discovered a small molecule, pseudoceratonic acid (1), along with the new moloka'iamine derivatives, ceratinines N (2), O (3), and the previously reported compounds moloka'iamine (4), hydroxymoloka'iamine (5) and ceratinamine (6). The structural assignments of 1-6 were accomplished by interpretation of their NMR and HRESIMS spectral data. Pseudoceratonic acid possesses a dibrominated hydrazine-derived functional group not found in any reported chemical compound. Pseudoceratonic acid selectively inhibited the growth of E. coli and S. aureus, while ceratinine N selectively inhibited C. albicans. Further, ceratinine N showed potent cytotoxic effects against the triple-negative breast cancer, colorectal carcinoma, and human cervical carcinoma cell lines down to 2.1 µM.

Synthesis, antimicrobial evaluation, DNA gyrase inhibition, and in silico pharmacokinetic studies of novel quinoline derivatives

Herein, we report the synthesis and in vitro antimicrobial evaluation of novel quinoline derivatives as DNA gyrase inhibitors. The preliminary antimicrobial activity was assessed against a panel of pathogenic microbes including Gram-positive bacteria (Streptococcus pneumoniae and Bacillus subtilis), Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), and fungal strains (Aspergillus fumigatus, Syncephalastrum racemosum, Geotrichum candidum, and Candida albicans). Compounds that revealed the best activity were subjected to further biological studies to determine their minimum inhibitory concentrations (MICs) against the selected pathogens as well as their in vitro activity against the E. coli DNA gyrase, to realize whether their antimicrobial action is mediated via inhibition of this enzyme. Four of the new derivatives (14, 17, 20, and 23) demonstrated a relatively potent antimicrobial activity with MIC values in the range of 0.66-5.29 μg/ml. Among them, compound 14 exhibited a particularly potent broad-spectrum antimicrobial activity against most of the tested strains of bacteria and fungi, with MIC values in the range of 0.66-3.98 μg/ml. A subsequent in vitro investigation against the bacterial DNA gyrase target enzyme revealed a significant potent inhibitory activity of quinoline derivative 14, which can be observed from its IC₅₀ value (3.39 μM). Also, a molecular docking study of the most active compounds was carried out to explore the binding affinity of the new ligands toward the active site of DNA gyrase enzyme as a proposed target of their activity. Furthermore, the ADMET profiles of the most highly effective derivatives were analyzed to evaluate their potentials to be developed as good drug candidates.