Negative Strains Research Articles

Synthesis, Spectroscopic, Antibacterial, Antioxidant, DNA Binding and Cleavage, Molecular Docking Studies of Ni(II) and Cu(II) Complexes of S and N Donor Schiff Base Ligands

Binary metal complexes of the ligands (L), H3FPT and H3FP4MT with Ni(II) and Cu(II) metal ions (M) were synthesized and characterized by different spectral and analytical techniques. Among these complexes, Ni(II)- H3FPT complex was found to be polymeric. The ligands and their complexes inhibited the growth of gram positive and gram negative bacterial strains to a moderate extent. The antioxidant nature of ligands and complexes was also established. Intercalative mode of binding of the complexes with calf thymus (CT) DNA was proposed from electronic absorption titrations, fluorescence quenching studies and viscosity measurements. The complexes showed hydrolytic cleavage of plasmid pBR322. Docking studies of metal complexes with DNA revealed that the complexes of H3FP4MT are more active than H3FPT.

Antibacterial Activity of Mangrove Root Extracts from Ngurah Rai Mangrove Forest, Denpasar-Bali

The increasing rate of antimicrobial resistance in the past decades has motivated the search for novel antibacterial compounds to overcome infectious diseases. Among diverse natural sources, mangrove ecosystems offer untapped sources of biological active compounds for future antibacterial medicine. This research was aimed to evaluate antibacterial activities of crude extracts of four dominant mangrove plants from the Ngurah Rai Mangrove Forest namely Rhizophora mucronata, Avicennia marina, Rhizophora apiculata, and Sonneratia alba. Roots of these four plants were extracted using methanol, chloroform, and n-hexane. These crude extracts were tested against two Gram positive bacteria (Staphylococcus aureus and Streptococcus mutans) and two Gram negative bacteria (Escherichia coli dan Klebsiella pneumoniae) by disc difussion assay. We found that 3 mg/mL of N-hexane crude extracts from R. apiculata yielded the highest zone of inhibition of 8.64 mm against S. aureus. While, 3 mg/mL of chloroform crude extract of R. apiculata yielded the highest inhibition of 19.83 mm against S. mutans. Unfortunately, no zone of inhibition was observed when crude extracts were tested against Gram negative indicator strains. Our results indicate that the root crude extracts of R. apiculata yielded the highest zone of inhibition against Gram positive indicator strains compared to root crude extracts of R. mucronata, S. alba, and A. marina. Further research is required to determine the antibacterial activities of the mangrove crude extracts against other bacterial indicator strains to determine their spectrum of activities.

Economic and ecological complexity in the wake of COVID-19 pandemic: evidence from 60 countries

The coronavirus disease 2019 is a deadly disease that globally infected millions of people. It enormously increases economies national healthcare bills and death tolls that deprive the global world. The negative environmental externality further strains the country's healthcare sustainability agenda, causing to decline in global income. The study evaluates the different socio-economic and environmental factors to assess ecological complexity in a large, cross-country data set that includes 60 countries. The study used the following variables for estimation, i.e., coronavirus cases, cost of carbon emissions, per capita economic growth, foreign direct investment inflows, and population growth. Markov Switching Regression, VAR Granger causality and variance decomposition analysis applied on the given dataset. The results show that the COVID-19 cases have a rebound effect on environmental quality. Economic activities started after a lifted lockdown, and unsustainable production and consumption led to a deteriorating natural environment. The U-shaped relationship is found between carbon pollution and per capita income. On the other hand, the inverted U-shaped relationship is found between coronavirus cases and carbon pollution. The foreign direct investment inflows and population density increases carbon pollution. The study concludes that stringent environmental policies and incentive-based regulations help to minimize coronavirus cases and mitigate carbon pollution.

Fabrication of zero-valent iron nanoparticles by green and chemical reduction methods: Application in the field of antibacterial activities for medicinal point of view

In the area of life sciences,iron nanoparticles (Fe NPs) have many applications. In this paper, the unique properties of iron nanoparticles as antimicrobials are studied. In this study, nanoparticles of iron have been fabricated by green and chemical reduction method. With the help of FESEM analysis and Zeta size analysis, the usual value of nanoparticles was found to be 10-30 nm in size. Furthermore, the prepared nanoparticles were examined for antibacterial perspective aligned with gram-positive and negative strains namely Staphylococcus aureus & Bacillus subtilis and Escherichia coli, using agar plate method and IC was also estimated using tube dilution assay.

Ni(II), Pd(II) and Pt(II) complexes of N,N-bis(3,3-dimethyl-allyl)-dithiocarbamate: Synthesis, spectroscopic characterization, antimicrobial and molecular docking studies

A potassium salt of N,N-bis(3,3-dimethyl-allyl)-dithiocarbamate has been synthesized from three step processes involving the synthesis of bis(3,3-dimethyl-allyl)-cyanamide and subsequent conversion to N,N-bis(3,3-dimethyl-allyl)amine. The dithiocarbamate ligand was obtained in a rapid exothermic reaction involving the amine and carbon disulfide in alkali medium, and its Ni(II), Pt(II) and Pd(II) complexes are reported. The characterization of the ligand and its metal complexes were carried out using various spectroscopic (FTIR, NMR, Mass) and magnetic susceptibility measurements. Square planar structures were proposed for the complexes as obtained from single crystal X-ray diffraction studies for Pt (II) and Pd(II) complexes and magnetic moment study for the Ni(II) complex. Antimicrobial susceptibility screening of the compounds was carried out using Gram positive strains: Bacillus subtilis and Staphylococcus aureus, Gram negative strains: Escherichia coli and Pseudomonas aeruginosa, and a fungal species: C. albicans. The drugs ciprofloxacin and ketoconazole were used as the reference standard drugs. The metal complexes showed significant antimicrobial activity. Thus, further study on this approach could pave a way for the development of dithiocarbamate-metal complex based antimicrobial agents.

Assessment of bactericidal role of epidermal mucus of Heteropneustes fossilis and Clarias batrachus (Asian cat fishes) against pathogenic microbial strains

This research was directed to understand the bactericidal effect of epidermal mucus of two Asian cat fish species viz. Clarias batrachus and Heteropneustes fossilis. Epidermal mucus extracts (raw and diluted) of both cat fish species were tested against several Gram negative (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, A. hydrophila) and Gram positive bacterial strains (Bacilliuscereus, Staphylococcus aureus, S. epidermidis) and antibacterial results were also compared with two standard antibiotics viz. amikacin and chloramphenicol used as positive control. An A. hydrophila challenge experiment was also performed on all selected test fish species to examine the change in the amount of mucus production and its bactericidal impact.. Both epidermal mucus extracts (raw and diluted) of all selected normal and bacterial challenged test objects showed potent bactericidal effect against all pathogenic bacterial strains taken under study. However, former was more effective than later. Also raw epidermal mucus extracts of both normal and bacterial challenged cat fish species exhibited significantly higher ZOI values against all selected microbial strains than diluted mucus extracts and antibiotic chloramphenicol. Hence, these outcomes have clearly revealed that this cost effective natural product acquired from fishes is the key component of their defensive system. Therefore, it could be utilized as a novel ‘antimicrobial’ in human as well as veterinary sector for combating against several bacterial diseases.

Stress response mechanisms and description of three novel species Shewanella avicenniae sp. nov., Shewanella sedimentimangrovi sp. nov. and Shewanella yunxiaonensis sp. nov., isolated from mangrove ecosystem.

Three Gram-staining negative, facultatively anaerobic, rod-shaped and motile strains, FJAT-51800T, FJAT-52962T and FJAT-54481T were isolated from the sediment samples of Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. The 16S rRNA gene sequencing results indicated they could be novel members of the genus Shewanella. The optimum temperature for growth was 30°C. The respiratory quinones of the strains were ubiquinone Q-7 or Q-8, and menaquinone MK-7. Polar lipids of the strains FJAT-52962T and FJAT-51800T were phosphatidyl glycerol, phosphatidyl ethanolamine, and unidentified aminophospholipids while strain FJAT-54481 consist of phosphatidylglycerol, phosphatidylethanolamine, unidentified aminophospholipids, two unidentified aminolipids and four unidentified lipids. The major fatty acid of the three strains was iso-C15:0. The genomic DNA G + C contents of strains FJAT-51800T, FJAT-52962T and FJAT-54481T were 48.2, 55.3 and 48.1%, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strains FJAT-51800T, FJAT-52962T and FJAT-54481T and other closely related Shewanella members were below the cut-off level (95-96%) for species identification. Genome analysis showed that these strains encode genes for osmo-regulation. Based on the results of phenotypic, chemotaxonomic and genome analyses, strains FJAT-51800T, FJAT-52962T and FJAT-54481T represent three novel species of the genus Shewanella, for which the names Shewanella avicenniae sp. nov., Shewanella sedimentimangrovi sp. nov., and Shewanella yunxiaonensis sp. nov., are proposed. The type strains are FJAT-51800T (= GDMCC 1.2204T = KCTC 82448T), FJAT-52962T (= MCCC 1K05496T = KCTC 82445T) and FJAT-54481T (= GDMCC 1.2348T = KCTC 82646T).

Effects of lattice strain on noble metal (110) surface: Missing row reconstruction and adsorption properties

Strain engineering of noble metals may optimize their adsorption properties and catalytic performance. On the other hand, while it has been shown that lattice strain may change surface reconstruction for some crystals, it remains to be seen whether strain-induced surface phase transition will modify the adsorption and catalysis properties. In this contribution, we address this issue by density functional methods. We show that 4d elements of Rh, Pd, and Ag change from unreconstruction to 1 × 2 missing row reconstruction under negative strains, while 5d ones including Ir, Pt, and Au change from reconstruction to unreconstruction under positive strains. Strain-induced surface phase transition results in abrupt changes in hydrogen adsorption strength. The present results imply that it is important to consider possible modifications in surface reconstruction to understand catalytic performance of strained noble metals.

Determination of Ferrous Oxide Nanoparticles Minimum Inhibitory Concentration against Local Virulent Bacterial Isolates.

The improvement of multi-resistance properties of the bacterial pathogen has recently been discussed as an emerging issue. In this regard, iron oxide nanoparticles have attracted the researchers' attention due to their wide application in the realm of medicine. Iron oxide nanoparticles have a high specific surface area that enables them to interact with the bacterial surface structure and has considerable antibacterial activity. The current study aimed to synthesize a novel antimicrobial agent from iron oxide nanoparticles and determine its minimum inhibitory concentration (MIC) on different gram-positive and negative variant bacterial strains isolated and characterized from the infected urinary tract of Iraqi elderly patients. This study was conducted from September 2020 to December 2020 on 75 urine samples collected from the infected urinary tract of elderly patients in the ages range of 60-75 years admitted to Al-Yarmouk Medical Hospital, Baghdad, Iraq. Isolation of bacterial isolates was carried out using differential and selective media. Afterward, they were characterized and confirmed using different biochemical tests and VITEK 2 system, respectively. Magnetic nanoparticles were fabricated by co-precipitation of ferric ions (Fe3+) and ferrous ions (Fe2+) in presence of ammonium hydroxide solution (25%). The characterization of synthesized nanoparticles was performed subsequently using UV-VIS spectroscopy analysis, Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy analysis, X-ray Diffraction analysis (XRD), and Energy-dispersive X-ray spectrum (EDX). The MIC of synthesized sonicated Fe3O4NP against different bacterial strains was determined using the broth culture dilution method through making serial dilutions of 50, 100, 200, 400, 500, 600, 800, 900 µg/ml from a 5mg/ml nanoparticle stock solution. Afterward, the lowest concentration of nanoparticles required to arrest the growth of bacteria was determined through the colony-forming unit of each treated bacteria on brain heart infusion agar. In total, 17bacterial isolates were identified from the infected urinary tract, five bacterial isolates (E. coli, Pseudomanas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, and Micrococcus luteus). In addition, two Proteus mirabilis strains were identified separately and were tested against synthesized Fe3O4NP to determine the MIC. The novel synthesized antibacterial agent showed excellent bioactivity, compared with controls (consisting of bacterial suspension without ferrous oxide nanoparticles), and the synthesized antibacterial agent was considered significantly active against all the bacterial strains at a p-value less than 0.05. The Fe3O4NP were active against gram-negative more than gram-positive bacteria. The MIC of synthesized and characterized Fe3O4NP wasapplied on seven gram-positive and negative bacterial isolates using bacteria-Fe3O4NP complex. Significant effects were observed on all strains, compared with controls, and this complex could significantly inhibit gram-negative more than gram-positive bacteria.

Control of Staphylococcus aureus methicillin resistant isolated from auricular infections using aqueous and methanolic extracts of Ephedra alata

In the current study the potential use of aqueous and methanolic extracts of Ephedra alata aerial parts as biological control agent against pathogenic bacteria and especially Staphylococcus aureus methicillin resistant isolated from auricular infections was evaluated. Chemical tests and spectrophotometric methods were used for screening and quantification of phytochemicals. The assessment of the antioxidant activity was accomplished by DPPH and ABTS radicals scavenging assays. Extracts were evaluated for their antibacterial efficacy by diffusion and microdilution methods. Biofilm inhibition was tested using XTT assay and the cytotoxicity of extracts was carried out on Vero cell line. The GC-FID analysis revealed that E. alata was rich in unsatured fatty acids. In addition, the aqueous extract had the highest flavonoid and protein contents (30.82 mg QE /g dry extract and 98.92 mg BSAE/g dry extract respectively). However, the methanolic extract had the highest phenolic, sugars and tannins. The antioxidant activity demonstrated that the aqueous extract exhibited the strong potency (IC50 ranged between 0.001 and 0.002 mg/mL).Both extracts displayed antimicrobial activity on Gram negative and positive strains. They were effective against S. aureus isolated from auricular infections. The tested extracts were able to inhibit biofilm formation with concentration-dependent manner.Moreover, no cytotoxic effect on Vero cells line was demonstrated for the extracts. Overall, our findings highlight the potential use of E. alata extract as a novel source of bioactive molecules with antioxidant, antibacterial and antiobiofilm effects for the control of infectious disease especially those associated to S. aureus methicillin resistant.

Electrocaloric Effect of (110) Oriented KNbO₃ Film.

The room temperature electrocaloric effect is researched for (110) oriented KNbO₃ film based on Landau-Devonshire theory. The phase map with different ferroelectric states is built at room temperature with the considerations of thermodynamic equilibrium conditions and minimum of thermodynamic potential. Five ferroelectric structural phases are obtained theoretically. The negative in-plane misfit strains are conducive to form the tetragonal c phase and the positive strains are in favor of the stability of tetragonal a1 and a₂ phases. The electrocaloric effect relies on both misfit strain and electric field. Moreover, large electrocaloric effect is achieved in the orthorhombic phases.

Development of Antibacterial, Degradable and pH-Responsive Chitosan/Guar Gum/Polyvinyl Alcohol Blended Hydrogels for Wound Dressing.

The present research is based on the fabrication preparation of CS/PVA/GG blended hydrogel with nontoxic tetra orthosilicate (TEOS) for sustained paracetamol release. Different TEOS percentages were used because of their nontoxic behavior to study newly designed hydrogels’ crosslinking and physicochemical properties. These hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and wetting to determine the functional, surface morphology, hydrophilic, or hydrophobic properties. The swelling analysis in different media, degradation in PBS, and drug release kinetics were conducted to observe their response against corresponding media. The FTIR analysis confirmed the components added and crosslinking between them, and surface morphology confirmed different surface and wetting behavior due to different crosslinking. In various solvents, including water, buffer, and electrolyte solutions, the swelling behaviour of hydrogel was investigated and observed that TEOS amount caused less hydrogel swelling. In acidic pH, hydrogels swell the most, while they swell the least at pH 7 or higher. These hydrogels are pH-sensitive and appropriate for controlled drug release. These hydrogels demonstrated that, as the ionic concentration was increased, swelling decreased due to decreased osmotic pressure in various electrolyte solutions. The antimicrobial analysis revealed that these hydrogels are highly antibacterial against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains. The drug release mechanism was 98% in phosphate buffer saline (PBS) media at pH 7.4 in 140 min. To analyze drug release behaviour, the drug release kinetics was assessed against different mathematical models (such as zero and first order, Higuchi, Baker–Lonsdale, Hixson, and Peppas). It was found that hydrogel (CPG2) follows the Peppas model with the highest value of regression (R2 = 0.98509). Hence, from the results, these hydrogels could be a potential biomaterial for wound dressing in biomedical applications.

SYNTHESIS, SPECTRAL CHARACTERIZATION AND ANTIMICROBIAL ACTIVITIES OF BIS(CYCLOPENTADIENYL)TITANIUM(IV) COMPLEXES WITH SCHIFF BASES DERIVED FROM5-(SUBSTITUTED ARYL)-2-HYDRAZINO-1, 3, 4-OXADIAZOLE AND INDOLINE-2, 3-DIONE

Titanium(IV) complexes of type[(η5-C5H5)2TiCl(L)] have been synthesized by the reactions of bis(cyclopentadienyl)titanium(IV)dichloride with Schiff bases (LH) derived by the condensation of 5-(substituted aryl)-2-hydrazino-1,3,4-oxadiazole and indoline-2,3-dione in tetrahydrofuranin the presence oftriethylamine. All these complexes are soluble in PhNO2, DMF and DMSO.The complexes were characterized by elemental analyses, electrical conductance, magnetic susceptibility, UV-Vis, IR, 1H NMR, 13C NMR, XRD and SEM spectral techniques. Low molar conductance values indicate that they are non-electrolytes. The spectral data indicate5-coordinate geometry for the complexes.XRD pattern indicate that the complexes have monoclinic crystal system and particle sizes were found 49.36 nm (nano-size). In vitro antifungal activity of synthesized compounds was evaluated against fungi Aspergillusniger, Aspergillusflavus,ColletotrichumfalcatumandIn vitro antibacterial activity was determined by screening the compounds against gram negative (P. aeruginosa, S.typhi) and gram positive (S. aureus and B.subtilis) bacterial strains using minimum inhibition concentration method (MIC) by serial dilution technique. The titanocene(IV) complexes have higher antimicrobial effect than the parent Schiff bases.

Enrichment Free qPCR for Rapid Identification and Quantification of Campylobacter jejuni, C. coli, C. lari, and C. upsaliensis in Chicken Meat Samples by a New Couple of Primers.

Campylobacter is the main cause of bacterial foodborne disease and poultry meat is the principal source of human infections. Rapid methods for Campylobacter detection are urgently needed to decrease high bacterial prevalence in poultry products. In this study, we developed new primers, CampyPFw and CampyPRv, that target the 16S-23S rRNA genes of Campylobacter jejuni, C. coli, C. lari and C. upsaliensis. The primers were tested on positive and negative reference strains in pure cultures and in inoculated poultry meat samples before their application in real-time PCR (qPCR) protocol for analyzing chicken meat samples. In parallel, the samples were tested by using the ISO 10272-1:2006 method. The qPCR protocol based on CampyPFw and CampyPRv showed good sensitivity, with the limit of detection of 4.6 × 102 cells/mL in chicken samples without enrichment steps.

Resistance of biofilm- and pellicle-embedded strains of Escherichia coli encoding the transmissible locus of stress tolerance (tLST) to oxidative sanitation chemicals

Biofilm formation in food processing plants reduces the efficacy of sanitation. The presence of transmissible locus of stress tolerance (tLST) also enhances resistance of planktonic cells of Escherichia coli to sanitation chemicals but the role of tLST in resistance of biofilm-embedded cells remains unclear. This study investigated the link of tLST to biofilm formation and its contribution to resistance of biofilm-embedded E. coli to sanitation. Biofilms were formed as single-strain and as dual-strain biofilms in association with E. coli, Aeromonas australensis or Carnobacterium maltaromaticum. Biofilms on stainless steel were compared to floating biofilms formed at the air-liquid interface (pellicles). The resistance of biofilm-embedded tLST positive strains of E. coli to chlorine, hydrogen peroxide, and peroxyacetic acid was higher than the resistance of tLST negative strains. Higher biofilm density as measured by crystal violet staining was observed in tLST-positive strains of E. coli when compared to tLST negative strains. Biofilm density positively correlated to resistance to disinfectants. The use of confocal laser scanning microscopy detected more compact structure of pellicles compared to solid surface-attached biofilms, resulting in higher chlorine resistance despite the absence of tLST in strains of E. coli. Collectively, the findings of this study elucidated the impact of tLST in strains of E. coli on biofilm formation and sanitizer resistance. These findings may inform the development of improved sanitization protocols for food facilities.

IN SILICO ANALYSIS OF GCR1 GENE IN CRABTREE POSITIVE AND CRABTREE NEGATIVE YEAST SPECIES

The use of fermentation in the presence of oxygen and at high glucose concentrations is referred to as the Crabtree effect. Yeast species that have the Crabtree effect are called Crabtree positive, and yeast species that do not have the Crabtree effect are called Crabtree negative. While Crabtree negative yeast strains are mostly used for heterologous protein production in the industrial field, Crabtree positive yeast strains are used to understand metabolic events in cancer cells. The genes encoding the enzymes involved in the glycolytic pathway in S. cerevisiae yeast cells are controlled by Gcr1p. Gcr1p binds to CT elements located in the promoter regions of glycolytic genes and activates their transcription. In our study, Crabtree positive and negative yeast strains containing Sc-Gcr1p similar proteins were determined, and protein similarity analyzes and promoter analyzes of genes encoding the relevant proteins in these yeast strains were compared in silico using different databases and analysis programs. For this purpose, SGD, UNIPROT, NCBI-Genome and Yeastract databases and BLASTp-NCBI, MEGA-X and Chromatin Folding V2 programs were used. Using the SGD database, 32 different yeast strains were identified that matched with Sc-Gcr1p. Five different Crabtree positive and 5 different Crabtree negative yeast strains were selected from these yeast strains and in silico analyzes were performed using these yeast strains. After protein analysis and promoter analysis, it was determined that the similarities and differences between yeast species were not specific for Crabtree positive and Crabtree negative yeast species, but varied between species.

Mesoporous silica incorporated PCL/Curcumin nanofiber for wound healing application

Electrospinning, a recent fast-emerging technique highly applicable in the production of nanofibers has gained vast recognition owing to its explicit applications in various domains. Amongst which, the production of nanoscaffolds for wound healing applications has been focused recently due to advantages over conventional wound healing methods. In the present research, a composite nanoscaffold comprising SBA-15 (Santa Barbara Amorphous), amine functionalized SBA-15 polycaprolactone (PCL) and curcumin was investigated for its potentiality in wound healing therapeutics. The high biocompatibility and cell adhesion of amine functionalized SBA-15 and the widely explored antimicrobial properties of curcumin added benefit for the wound healing target. The prepared highly interconnected electrospun fibers with porous structure were characterized through various studies such as FTIR, XRD, SEM and EDAX. Further, antibacterial studies against both Gram positive (Bacillus subtilis) and Gram negative (Escherichia coli) strains revealed an improved zone of inhibition. Major invitro studies such as cell migration, proliferation, bio-compatibility was experimented through cell adhesion and live and dead assay using Swiss 3T6 cell lines. In vivo studies on female Wister rats using the fabricated nanofibers incorporated with curcumin and amine functionalized SBA-15 showed 99% scar-less wound healing within 21 days. Re-epithelization of tissue, collagen deposition and formation of granulation tissue were observed from the results of Hematoxylin-Eosin and Masson's tri-chrome staining. From the observations, it can be concluded that the fabricated nanoscaffold could be an effective substrate for wound healing therapeutics.

Antimicrobial Resistance Profiles and Genetic Typing of Salmonella Serovars from Chicken Embryos in China.

Salmonella continues to be a major food and public health burden worldwide that can threaten human health via eating contaminated meats, particularly those originating from chicken. In this study, the antimicrobial resistance profiles, epidemiological characteristics of resistance genes, and pulsed field gel electrophoresis (PFGE-XbaI) typing of 120 non-Pullorum/Gallinarum Salmonella isolates recovered from chicken embryos in Henan province were determined. The antimicrobial resistant phenotypes and evaluation of the extended-spectrum beta-lactamases (ESBLs) producing strains of Salmonella were investigated by the Kirby–Bauer test and the double-disk synergy test. Additionally, 37 antimicrobial resistance genes encoding resistance to five different categories, including aminoglycosides, cephalosporins, sulphonamides, tetracyclines, and β-lactams, were examined by conventional PCR. However, genotyping analysis was conducted by macro-restriction using enzyme XbaI followed by the separation of the restricted DNA fragments by PFGE. The results of this study showed that the studied Salmonella strains were highly resistant to ampicillin (66.67%) and sulfisoxazole (66.67%), while they were all susceptible to meropenem, imipenem, colistin, and chloramphenicol. Additionally, 67.5% (81/120) of the studied strains were multidrug resistant, and 21.67% (26/120) were phenotypically confirmed as ESBLs positive. The statistical analysis showed that resistance depends on the serovars, and ESBLs positive strains showed more multi-resistance than ESBLs negative strains (p < 0.05). The genotypic antimicrobial resistance showed the detection of 14 among the 37 tested genes, and the concordance between genotypic and phenotypic antimicrobial resistance ranged from 0% to 100% depending on the serovars. However, the PFGE-XbaI typing results showed that the examined Salmonella strains were divided into 22 individual subtypes and were grouped in nine clusters, with similarity values ranging from 64.7% to 100%. From this study, we can conclude that the antimicrobial resistance of Salmonella serovars isolated from chicken embryos in Henan province was alarming, with rigorous multidrug resistance, which requires the urgent mitigation of the use of antimicrobial drugs in chicken hatcheries. Additionally, our results showed evidence of the presence of different PFGE patterns among the studied Salmonella serovars, suggesting the presence of different sources of contamination.

Fe(III), Co(II) &amp; Cu(II) Complexes of N,N’-Bis[2-salicylideneamino]ethane-1,2-diamine: Preparation, characterisation and in vitro antibacterial activity

Salicylaldehyde derived hexadentate Schiff base N,N’-Bis[2-salicylideneamino]ethane-1,2-diamine (TTS) and its complexes with Fe(III), Co(II) and Cu(II) metal ions have been prepared and characterised by elemental analysis, UV-visible, IR, 1 H NMR, EPR spectral analysis, mass spectrometry and XRD method. In vitro antibacterial activity of the Schiff base and its metal complexes against Gram positive bacterial strains Staphylococus aureus , Bacillus subtilis and Gram negative bacterial strains Enterobacter , Escherichia coli has revealed that the metal complexes are more active to the bacterial strains as compared to that of the Schiff base. The Co-TTS has the highest antibacterial activity against Escherichia coli , while the Fe-TTS complex is highly active against Enterobacter , Staphylococcus aureus and Bacillus subtilis.

Isolation and identification of the oral bacteria and their characterization for bacteriocin production in the oral cavity.

Oral cavity is a diverse ecosystem which harbors immense diversity of microorganisms like fungi, virus and bacteria. Some of these microorganisms are involved in causing multiple infections. Oral flora is continuously changing due to connection with the external environment and produce bacteriocin against each other to compete for nutrient in this mini ecosystem. Current study was aimed to explore and compare the bacterial fauna of both healthy and non-healthy dental samples, by isolation and identification with biochemical tests to characterize the bacteriocin production. During study 120 swabs were taken from both healthy and unhealthy subjects. Samples were collected from the dental clinics of Makkah City, in sterile eppendorfs containing 1 ml nutrient broth, and were incubated overnight using shaking incubator. Bacteria were isolated following identification through Gram staining, microscopy and biochemical test. Total 15 strains of bacteria were isolated during the study amongst which 8 strains were gram positive and 7 strains were gram negative. The most dominant species of the gram positive strains was Streptococcus pneumoniae (n = 26). On the other hand, Escherichia coli (n = 26) was the prominent specie amongst the gram negative strains. Overall, the dominated family was Enterobacteriaceae (19.36%) followed by Streptococcaceae with 13.83% abundance. One of the most cariogenic strain Klebsiella pneumoniae (n = 14) was also isolated. The bacterial strain diversity between these two type of ecosystem was approximately the same, with slight variation in Shannon (HS:2.627187, NHS:2.653594) and Simpson diversity (HS:0.923461, NHS: 0.92684) index. The current research revealed that bacteriocin production in the Enterobacter species was prominent against Escherichia coli and Klebsiella pneumoniae. Apart from this other strains like Klebsiella pneumoniae and Exiguobacterium spp were also able to produce bacteriocin against Enterobacter species and Bacillus cereus respectively.