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Background: Staphylococcus aureus is a very important hospital and community-acquired pathogen that is prevalent in burn wounds, so finding the sources of contamination and infection with it are important for its control. The aim of this study was to do SCCmec typing and determine the prevalence of pvl, ACME, sea and seb genes among S. aureus isolates from burn patients. Methods: Fifty S. aureus isolates were sampled from burn patients and were identified. These isolates were typed based on SCCmec typing and detection of mecA and pvl genes using multiplex polymerase chain reaction (PCR) method and also were screened for the presence of ACME, sea and seb genes by PCR. Results: Three isolates were identified as methicillin-resistant strains. The sea gene was identified in 22% of isolates while pvl, ACME and seb genes were not found in the isolates. Multiplex PCR SCCmec typing of 3 methicillin resistant S. aureus (MRSA) isolates showed that 2 isolates belong to SCCmec type II and 1 isolate to type I. Conclusions: The results suggest that methicillin resistant S. aureus isolates are prevalent in burn patients and mecA gene is involved in resistance to methicillin. These strains belonged to SCCmec type II and I which can affect horizontal gene transfer among S. aureus isolates and hence distribution of virulence genes. Therefore, it is necessary to frequently monitor S. aureus isolates through typing and screening virulence genes to control this pathogen.

Removing the precipitated asphaltenes from the facilities of oil industry is of vital importance. In this study, the possibility of the precipitated asphaltene biodegradation from a crude oil sampl...

Microbial Enhanced Oil Recovery (MEOR) is a term which is attributed to the process of utilizing bacterial activity for increasing the recovery factor of oil reservoirs. This process relies on several mechanisms especially interfacial tension reduction and wettability alteration mechanisms. The main purpose of this work is to evaluate the impact of these mechanisms during MEOR process for microorganism isolated from formation water of one of the Iranian southwest carbonate oil reservoirs. The isolated microorganism was identified to be Alcaligenes faecalis. The optimum condition for growth of microorganism was found at 28 °C, pH = 7, carbon to nitrogen ratio of 30 and 3% salinity. Results show that the selected microorganism is able to reduce the interfacial tension between formation brine and crude oil from 28.1 mN/m to 8.4 mN/m and alter the wettability of reservoir rock from approximately 156° to 86° which represents a change from oil-wet condition toward intermediate-wet. Results show that the isolated microorganism is able to produce 8.2% and 5.2% additional oil recovery in respective shut in and quick flooding scenarios. This show that the isolated microorganism is efficient in production of additional oil as a part of tertiary oil recovery process.

Five dinuclear organotin(IV) complexes, R4Sn2La (R = Me, Ph) and R4Sn2Lb (R = Me, Ph and Bu) have been synthesized from reaction of R2SnCl2 with 2,4′- and 2,2′-bis-substituted diphenylamine arylidene hydrazones, H4La and H4Lb, respectively. The synthesized compounds have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopy. The structures of Me4Sn2Lb and Ph4Sn2Lb have been also confirmed by X-ray crystallography. The results show that the fully deprotonated bis-hydrazone ligand provides two contiguous ONO tridentate domains that coordinate to the two SnR2 moieties in the enolate form. Each tin atom in the complexes adopts a five-coordinate environment. Ligands and complexes showed no antibacterial activity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. However, both ligands and their methyl complexes were found to degrade DNA, an observation that adapt with the mode of interaction suggested by molecular docking.

Cell surface hydrophobicity (CSH) is one of the key physicochemical features of biodemulsifier-producing bacteria that influence their demulsification capability maintenance in petroleum contaminated environments. In present study, biodemulsifier-producing bacteria were isolated from petroleum contaminated environments using different isolation media and the correlation between their CSH and demulsifying ability was investigated. The demulsifying ability of isolates was measured through demulsification tests on water in kerosene emulsions. The microbial adhesion to the hydrocarbon (MATH) assay was used to denote their CSH. The evaluation of CSH showed that majority of biodemulsifier producing bacteria have high CSH which indicating a positive correlation between CSH and demulsifying capability. According to these results it can be concluded that CSH can be used as an indicator for assessment of biodemulsifier-producing bacteria and screening of new isolates for their biodemulsifier production.

The TiO 2 hollow spheres were synthesized using a green, cheap, and easy process, in which carbonaceous spheres were chosen as the removable template. The prepared materials were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), Atomic force microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. According to the results, the obtained mesoporous TiO 2 hollow spheres demonstrated an external diameters less than 200 nm with shell thickness around 40 nm. The antibacterial activities of the TiO 2 hollow spheres were evaluated against gram-positive ( Bacillus subtilis and Staphylococcus aureus ) and gram-negative ( Escherichia coli and Pseudomonas aeruginosa ). No antibacterial activity was found for TiO 2 hollow spheres in the used concentrations. TiO 2 hollow spheres were loaded with gentamycin as a selected antibiotic to magnify their benefits in biomedical applications. TiO 2 hollow spheres exhibited good antibiotic carrier activity for the direct delivery of gentamicin, which was attributed to interaction between gentamicin and surface due to their larger specific surface area, more abundant porous structure, and their spherical morphology. The application of TiO 2 hollow spheres as gentamicin carrier undoubtedly opens an avenue to use hollow sphere materials in other drug delivery applications.

Seismic and well data are utilised to describe the tectono-stratigraphic evolution of the eastern Persian Gulf during the Late Mesozoic and Cenozoic. The structural framework of the study area is the result of the Late Cretaceous to Early Miocene Oman Orogeny overprinted by the southwestward advance of the Zagros Orogeny through the Late Miocene and Pliocene. Two structural domains can be identified; The NE-SW trending Musandam Fold-Thrust Belt (MFTB) and the NW-SE trending Persian Gulf foredeep basin. The MFTB formed as a result of multiple compressional events (Late Cretaceous, Late Paleocene to Early Eocene and Late Oligocene to Early Miocene). The first compressional event (Cenomanian- Turonian to the Maastrichtian) is characterized by emplacement-obduction of the allochthonous rocks onto the passive continental margin of the Arabian plate in the Oman Mountains. This event led to regional deformation and uplift which caused deep erosion of the Albian to Santonian units. During the Santonian to Maastrichtian, in addition to regional deformation, a NE-SW trending foredeep basin developed in front of the Late Cretaceous thrust sheets creating accommodation space for turbiditic deposits of the Gurpi Formation. During the Late Paleocene- Early Eocene, initiation of a new compressional deformation led to establishment of the Pabdeh foredeep basin. In this stage, the basin depocenter migrated ∼30 km to the west. The third compressional event began in the Late Oligocene reaching a climax in the Early Miocene. This event resulted in regional deformation and uplift which caused deep erosion of the pre-Middle Miocene strata. The Persian Gulf foredeep basin has developed in front of the rising Zagros Mountains since Late Miocene- Pliocene. Folding related to advancement of the Zagros Orogeny into the Persian Gulf is mainly restricted to northeastern flank (near the coast of Iran). The effect of folding decreases to the south of the Zagros Deformational Front.

Coordination polymers [CdCl(NCS)L]n (1) and {[Cd2I4(L)2]·H2O·DMF}n (2) (where L = 1, 1-(1,4-butanediyl)bis(1,3-dihydro-3-methyl-1H-imidazole- 2-thione)) were synthesized and structurally characterized. Compounds 1 and 2 both possess a tetrahedral arrangement with CdS2NCl and CdS2I2 cores, respectively. In these structures, the flexible thione ligands adopt a μ- bridging coordination mode to form 1D chains along the b-axis. The 1D chains are join together by C–H---Cl hydrogen bonds (in 1) and water molecules (in 2) to create a 2D supramolecular framework with an ABAB…packing mode. Remarkably, compounds 1 and 2 in particular polymer 1 exhibit excellent capacity to adsorb Congo red (CR) with high selectivity. The experimental data demonstrate that the mechanism of sorption process can be described by the Elovich and pseudo second order kinetic models for 1 and 2, respectively. Furthermore, the possible mechanism of CR absorption was investigated by UV–Vis and solid state fluorescence spectra for the title polymers. In addition, the antibacterial assessment of these compounds have also been studied.

Mesoporous silica nanoparticles (MSNs) were prepared by sol-gel method and functionalized with 3-aminopropyltriethoxysilane. Schiff base grafted mesoporous silica nanoparticle was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and amine-functionalized MSNs. The latter material was then treated with Cu(II) and Ni(II) salts separately to obtain copper and nickel complexes anchored mesoporous composites. The newly prepared hybrid organic-inorganic nanocomposites have been characterized by several techniques such as FT-IR, LA-XRD, FE-SEM, TEM, EDS, BET and TGA. The results showed all samples have MCM-41 type ordered mesoporous structure and functionalization occurs mainly inside the mesopore channel. The presence of all elements in synthesized nanocomposites and the coordination of Schiff base via imine nitrogen and phenolate oxygen were confirmed. MSNs and all functionalized MSNs have uniform spherical nanoparticles with a mean diameter less than 100 nm. The as-synthesized mesoporous nanocomposites were investigated for antibacterial activity against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria, as carrier for gentamicin and also for immobilization of DNase, coagulase and amylase enzymes. MSN-SB-Ni indicated bacteriocidal effect against S.aureus and all compounds were found to be good carrier for gentamicin. Results of enzyme immobilization for DNase and coagulase and α-amylase revealed that supported metal complexes efficiently immobilized enzymes.

The aim of this study is to investigate the role of interaction pattern between the Fe3O4 exposed by magnetic field as a temporary nanomagnets (TNMs) against bacterial interfaces, affecting antimicrobial trends of TNMs. The magnetite nano particles were prepared by the coprecipitation of Fe3 + and Fe2 + ions. The Fe3O4 nanoparticles without any modification is called MNPs and Fe3O4 nanoparticles treated in the magnetic field is called TNMs. Functionalization by azo compounds using 3-Amino propyl triethoxysilane as a linker resulted in azo-compound @ MNPs. Azo-compound @ TNMs is a temporary nanomagnets treated by external magnetic field and during all tests it has magnetic property. The structural and magnetic properties of magnetic nanomaterials are identified by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) instruments. FT-IR and XRD were also used for the identification of these structures. All of the antibacterial tests were performed using MNPs and TNMs against two Gram positive and two Gram negative bacterial species. It is determined that the exposing of magnetic fields to magnetic nanoparticles can change the biological activity and increase the bacteriostaticity of these nano composites in bacterial medium. The TNMs may serve as a useful model system to apply electromagnetic interactions of Nano particles in biological system. Since TNMs are very unstable and oxidized in aqueous solution, surface modification of TNMs is crucial for biomedical applications. Functionalizations of TNMs by azo compounds protect them from red-ox reactions and improve their stability making nanoparticles better antibacterial nanocomposite.

Dual function silica-iron oxide hybrid nanocomposite, (Fe3O4@SiO2 PEG/NH2) was newly designed and prepared by grafting of PEG and 3-aminopropyltriethoxysilane (APTES) on the silica-coated magnetic nanoparticles (Fe3O4@SiO2). The resulting nanocomposite was characterized by Fourier transform infrared spectroscopy (FT–IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The nanocomposite demonstrated a catalytic performance in the one-pot multicomponent synthesis of polyhydroacridines and polyhydroquinolines via the Hantzsch reaction under solvent free conditions. Atom economy, high yields, easy work-up procedure, environmentally benign, easy separation of the catalyst through an external magnet and mild reaction conditions are some of the important features of this protocol.

Two bis-hydrazone, H4La and H4Lb, have been synthesized from reaction of 5,5′-methylene-bis-salicylaldehyde with benzhydrazide and furan-2-carbohydrazide, respectively. New organotin(IV) complexes, (R2Sn)2L [L = La: R = Me (1), Ph (2); L = Lb: R = Me (3), Ph (4)] have been synthesized by reaction of dihydrazone ligands with R2SnCl2 (R = Me or Ph). The synthesized compounds have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopy. The structures of 1 and 2 have been also confirmed by X-ray crystallography. The results show that the dihydrazone acts as a tetrabasic ligand in the enolic form and is coordinated to two SnR2 moieties via ONO donor domains by the imine nitrogen and phenolic and enolic oxygen atoms. All complexes are binuclear and the coordination number of both tin is five. The in vitro antibacterial activity of ligands and complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and compared with standard drugs. The synthesized compounds also have been investigated for the chromosomal and plasmid DNA cleavage activity. The complexes significantly inhibited bacterial growth, while none of compounds showed DNA cleavage activity.

A 3-D cadmium-based coordination polymer, [CdCl2L]n (1) (where L = 1,1-(1,6-hexanediyl)bis(1,3-dihydro-3-methyl-1H-imidazole-2-thione), was synthesized and structurally characterized. The capability of the polymer as an efficient sorbent for Congo red (CR) removal from aqueous solution has been evaluated. Compound 1 has a tetrahedral arrangement with a CdS2Cl2 core. L in 1 is bidentate to two neighboring CdII centers via the methimidazole sulfurs to create 1D chains propagating along the c-axis. The remaining coordination sites are occupied by two terminal chlorides. The chains are further stabilized by intermolecular C–H⋯Cl hydrogen bonds between the chlorides and hydrogens of the imidazole rings. Parallel chains stack in the 3-D structure. The CdII polymer sorbent was characterized by infrared spectroscopy, elemental analysis, UV–vis, solid fluorescence and X-ray single-crystal diffraction. Sorption kinetics were studied by three kinetic models, second order, Elovich and intraparticle diffusion. The results indicate that the mechanism of the sorption process followed Elovich kinetic model. Sorption equilibrium was also studied with Langmuir, Temkin, and Freundlich isotherm models. The sorption process followed the Temkin isotherm. MIC, MBC, and DNA cleavage activities of 1 were also studied. Furthermore, the UV–vis and solid state fluorescence spectra of 1 were measured.

Two new isostructural Zn(II) and Cd(II) coordination polymers, namely {[Zn 2 (bbit) 3 Cl 2 ][ZnCl 4 ]} n ( 1 ) and {[Cd 2 (bbit) 3 Cl 2 ][CdCl 4 ]} n ( 2 ), have been synthesized and structurally characterized. These compounds represent the first examples of cationic coordination polymers with a tetrahedral MS 3 Cl [M = Zn(II) and Cd(II)] repeating unit. Each of these units is bridged to three symmetry-related ones through the bbit ligands. The 2D [M 2 (bbit) 3 Cl 2 ] 2+ cationic networks stack in an ABAB… sequence along the c -direction. From MIC, MBC and DNA cleavage activity studies, it can be concluded that the title compounds possess antibacterial activity.

The Dezful Embayment is located in the foreland part of the Zagros fold-and-thrust belt. Structural style of folding and thrusting vary in the Dezful Embayment. In this study, balanced cross sections and subsurface data including 2D seismic profiles and wells data decoded structural style of the subsurface structures in the northern Dezful Embayment. Presence of the multiple decollement horizons is the main controlling factor of the structural style in this area. The subsurface anticlines have been formed between two main decollement horizons, which include the Miocene Gachsaran Formation as upper decollement and Permian Dashtak evaporites and Lower Cretaceous Garau shales as the middle decollement horizons. Geometry of the subsurface anticlines differs much vertically and horizontally. Growth strata indicate folding is started in Middle Miocene time in this region. Anticlines formed as open, wide and disharmonic structures. Active processes in the evolution of anticlines are limb rotation and hinge migration, which was resulted in increase of inhomogeneous shortening rate. More shortening rate indicates more structural relief in anticlines. These anticlines are formed as a detachment folds in initiation and then during their evolution converted to fault propagation fold and fault-bend fold. Final geometric shape of these anticlines depends on the geometry of thrusts propagation that formed in the forelimb.

An investigation of the impact of alkyl spacer length of the flexible ligands and influence of shape and coordination ability of the counterions has been done on a series of five silver(I)-bis(imidazole-2-thione) coordination polymers. The five compounds, namely, [Ag2L4(NO3)2]n, {[AgL4]2[CF3SO3]2}n, [Ag2L6(CF3SO3)2]n, [Ag2L6(NO3)(ClO4)]n, and [Ag2L6Br2]n (L4 = 1,1′-(butane-1,4-diyl)bis(3-methylimidazoline-2-thione) and L6 = 1,1′-(hexane-1,4-diyl)bis(3-methylimidazoline-2-thione) have been characterized by elemental analysis, IR spectra, thermogravimetric analysis (TGA), powder X-ray diffraction, and single crystal X-ray diffraction. In the title polymers, the L4 and L6 ligands exhibit unprecedented coordination modes, and the Ag(I) centers adopt a range of coordination geometries. The single crystal structural analysis of the title compounds shows that polymers based on the L4 ligand predominately adopt AgS4 core structure which does not appear in the polymers containing L6 ligand. The TGA experimental da...

A new silver complex [Ag(C4H6N2)2]2Cr2O7 (1) derived from Ag2[CrO4] and 2-methylimidazole has been synthesized and fully characterized by Single crystal X-ray diffraction, UV–Vis, FT-IR, elemental analysis, DFT and AIM calculations. The crystal structure of 1 shows that the discrete, ionic compound of [Ag(C4H6N2)2]2Cr2O7 consists of two [Ag(C4H6N2)2]+ cations bridged by a [Cr2O7]2− counter anion. In each of the [Ag(C4H6N2)2]+ complexes, the Ag center is coordinated by two N atoms from two distinct neutral monodentate 2-methylimidazole ligands in an almost linear geometry with Ag N distances between 2.068(4) A and 2.076(4) A and N Ag N bond angles of 179.4(2)° and 173.8(2)°. The N H⋯O and C H ⋯ O hydrogen bonds, π⋯π stacking, C H⋯ π and Ag⋯O interactions play an important role in the structural stabilization of the complex to generate a three-dimensional framework. The antibacterial activity and molecular docking studies of the free 2-methylimidazole ligand and the title complex show that these compounds have ability to inhibit the growth of the tested bacteria. A scanning probe microscopy (SPM) study of the treated bacteria was carried out to investigate the structural changes caused by the interactions between the complex and target bacteria. The interaction of the complex 1 with the E.coli DNA (E-DNA) has been studied by UV–Vis absorption, competitive DNA-binding studies with ethidium bromide by fluorescence and gel electrophoresis techniques. These experiments indicate that the complex interacts with DNA by intercalative binding.

Background and Objectives: Fibrinolytic drugs are commonly used for fibrin clot lysis but due to their inappropriate side effects, as well as their high costs, using fibrinolytic enzymes has been paid attention. Bacterial sources of this enzyme are a good alternative for this purpose. The aim was fibrinolysin production through screening of fibrinolysin producing bacteria from environmental samples. Materials and Methods: Bacterial isolation was performed from different environmental samples and was screened based on sheep blood clot digestion and culture on plasma plate. The most potent isolate was optimized for different growth parameters including temperature, pH and fibrinolysin production at optimum growth conditions. The stability of produced enzyme at various temperatures and pH and treatment with MgSO4, NiSO4, SDS and EDTA was then investigated. Finally this isolate was identified based on the 16S rRNA sequencing. Results: As a result, from 79 different isolates, the most potent fibrinolysin producer was identified as Alcaligenes faecalis strain 26. This isolate produced 12 mm halo zone on plasma plate. Its optimum growth temperature and pH was 43°C and 7, respectively. The produced enzyme had the best stability at pH 7 and was also active up to 60°C. The fibrinolytic activity of this isolate was reduced following treatment with MgSO4, NiSO4 and also with protease inhibitors, such as SDS and EDTA. Conclusion: Based on the obtained results it can be suggested that Alcaligenes faecalis strain 26 has appropriate efficiency for fibrinolysin production that can be used in food industry and medicine.

Resistance to methicillin in methicillin resistant Staphylococcus aureus (MRSA) is dependent on mecA gene located on staphylococcal cassette chromosome (SCC). Both SCCmec type and Panton-Valentine leukocidin (PVL) affect S. aureus pathogenicity. Aim of this study was to investigate the prevalence of SCCmecA types and pvl genes among MRSA isolates from inpatients. During this cross-sectional study on 100 clinical isolates, following antibiotic susceptibility test, screening of mecA and pvl genes, as well as SCCmec typing, was done in a multiplex PCR technique. From the studied samples, 58 isolates were recognized as MRSA. The frequency of mecA and pvl was 58% and 4%, respectively. All of the MRSA were resistant to cefoxitin and had the highest sensitivity to chloramphenicol. The majority (77.5%) of MRSA was originated from wound samples. The SCCmec III was the most frequent type (22.4%) in these samples. The pvl positive isolates were from SCCmec IVb and V, thus meaning they are from CA-MRSA. These results show a high prevalence of MRSA in the studied region and a widespread prevalence of SCCmec I-V types. Furthermore, high prevalence of SCCmec III indicates the prevalence of multidrug resistant MRSA. This finding is a serious alarm for medical health care practitioners for the correct use of antibiotics in order to limit the spread of multidrug resistant strains. In addition, with regard to life threatening infections caused by pvl harbouring strains, early diagnosis and treatment of infections caused by these isolates should be mandatory.

One of the serious problems in the oil industry is precipitation and deposition of asphaltenes in the different oil production stages including formation, wellbore, production tubing, flow lines, and separation units. This phenomenon causes a dramatic increase in the cost of oil production, processing, and transferring. Thus, it seems to be very necessary to use the removing methods for precipitated asphaltenes in different crude oil production and transferring stages. In this study, the ability of microorganisms for biodegradation of precipitated asphaltenes was investigated. For this purpose, four bacterial consortiums were isolated from oil-contaminated soil, crude oil, reservoir water, and oil sludge samples of an oil field located in the southwest of Iran. Based on the results of the designed experiments, by using response surface methodology (RSM) and central composite design, the bacterial consortiums were cultured in the flasks. Three levels of temperatures, salinity, pH, and initial asphaltene concentration as the substrate were considered as the parameters of culture medium and incubated growth mediums for 60 days. The maximum asphaltene biodegradation was 46.41% caused by the crude oil consortium including Staphylococcus saprophyticus sp. and Bacillus cereus sp. at 45 °C, salinity 160 g·L-1, pH 6.5, and 25 g·L-1 initial asphaltene concentration. Also, it was observed that the negative or positive impacts of culture media conditions such as temperature and salinity on asphaltene degradation depended on the type of the available bacterial consortium. The carbon-hydrogen-nitrogen-sulfur analysis showed that carbon, hydrogen, nitrogen, and in some cases, the sulfur in biodegraded samples are less than in control samples. Moreover, Fourier transform infrared analysis indicated that the alkyne groups were less resistant to biodegradation and were eliminated thoroughly after 2 months of incubation. In addition, alkane components were partially removed in treated asphaltene fraction. The parameters of culture medium were optimized by RSM, and besides, their effects on the performance of bacteria in the asphaltene biodegradation process were discussed. The validity of some available kinetic models to describe the behavior of the studied bacteria consortium was investigated, and it was observed that Tessier, Moser, and Contois models accurately predict the values of asphaltenes and biomass concentration at 30, 45, and 60 °C, respectively.

Three organotin(IV) complexes, Ph4Sn2L (1), Me2Sn(H2L) (2) and Bu2Sn(H2L) (3) have been formed from reaction of R2SnCl2 (R = Ph, Me and Bu) with a multiprotic dihydrazone, 1,5-bis((2-hydroxynaphthaldehyde) thiocarbohydrazone (H4L). The synthesized compounds have been investigated by elemental analysis, IR, 1H NMR, and 119Sn NMR spectroscopy. The structure of 1 has been also confirmed by X-ray crystallography. The results show 1 is binuclear and fully deprotonated thiocarbohydrazone supplies two different tridentate dianionic domains, NNO and ONS, for coordination to two diphenyltin(IV) moieties. Coordination number of both tin(IV) center is five and it is maintain in solution. In 1 and 2 only one part of ligand as doubly deprotonated ONS donor was coordinated with tin and a mononuclear organotin complex with coordination number of five was formed. The in vitro antibacterial activity of ligand and complexes has been evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria and compared with standard drugs. The synthesized compounds also have been investigated for the chromosomal and plasmid DNA cleavage activity. All complexes significantly inhibited bacterial growth and completely degrade the treated DNA.

The termite gut contains different kinds of lignin and lignocellulose degrading microbes. This study was conducted to isolate and identify termite gut symbiotic bacteria with lignocellulose-degrading potential, and evaluate their effects on the chemical composition and in vitro digestibility of wheat straw and date leaves. Termite gut contents were extracted and cultured in 9 different culture media containing lignin and lignocellulosic materials that had been prepared from water-extracted sawdust and wheat straw. Three superior bacteria capable of growing on all media, and with higher lignin peroxidase activity, were selected and subjected to molecular identification. Following this, wheat straw and date leaves were incubated with the isolated bacteria in liquid medium for 6 weeks. 16S rRNA sequence analysis showed that these isolates possessed 97, 99 and 97% similarity with Bacillus licheniformis , Ochrobactrum intermedium and Microbacterium paludicola , respectively. The highest (P B. licheniformis . In the case of wheat straw, the organic matter (OM) and neutral detergent fiber (NDF), and for date leaves OM, NDF and acid detergent lignin (ADL) contents were not influenced by the treatments (P > 0.05). The greatest and lowest (P B. licheniformis and O. intermedium , respectively. However, bacterial treatments decreased (P M. paludicola and O. intermedium treatments, respectively. For date leaves, the CP content of the control treatment was highest (P O. intermedium and M. paludicola , respectively. For date leaves, treatment with B. licheniformis significantly increased (P 0.05) between experimental groups. Overall, the results of this study showed that the isolated bacteria partially changed the chemical composition of wheat straw and date leaves while, they improved digestibility of nutrients. These bacteria are suitable candidates for increasing nutritive value of by-products for ruminants.

Reaction of 1,1′-(butane-1,4-diyl)bis(3-methylimidazoline-2-thione) (bbit) with appropriate silver(I) and copper(I) salts at room temperature leads to the formation of {[Ag(μ2-bbit)](BF4)}n (1) and {[Cu2(μ-bbit)3](PF6)2}n (2) coordination polymers. These compounds have been fully characterized by using the single crystal X-ray diffraction, XRPD, TGA, elemental analysis, infrared spectroscopy, antibacterial activity and molecular docking studies. Crystal structure of (bbit) shows that the molecule has a center of symmetry lies at the mid-point of the (CH2)4 spacer between the two imidazole-2-thione rings. In the cationic 3D structure of 1, silver atom has a distorted tetrahedral coordination geometry and each of the centrosymmetric μ2-bbit ligands with an anticonformation bridging two crystallographically related silver atoms to form a double-bridged Ag(μ2-S)2Ag core as a basic building block. Coordination mode of the bbit ligands and geometry around the metal ions in polymers 1 and 2 are different. Each of the copper atoms in 2 has a trigonal planar CuS3 environment and μ-bbit act as a bridging bidentate ligand, so that two of the CuS3 motifs are interconnected by a pair of μ-bbit ligands through the thione sulfur atoms to generate a 22-membered [Cu2(μ-bbit)2]2+ ring. The adjacent [Cu2(μ-bbit)2]2+ cores are linked by a single μ-bbit ligand to form a 1D chain structure. Additionally, the adjacent 1D chains are extended into a non-covalent 3D network structure by the intermolecular P F…H hydrogen bonds. The in vitro antibacterial studies of bbit, polymers 1 and 2 showed that, polymer 1 was able to inhibit growth of the tested bacteria, whereas the bbit ligand has a weak and polymer 2 showed no antibacterial activity against these bacteria.

A series of copper-based polymers of [Cu(bbit)I]n (1), {[Cu(bbit)2](HSO4).(S8)0.5}n (2), [Cu4(CN)4 (bbit)2]n (3) and [Cu(bbit)Cl]n (4) have been designed and synthesized from reaction of CuX (X ​= ​I, Cl and CN) with 1,1-(1,4-butanediyl) bis (1,3-dihydro-3-methyl-1H-imidazole- 2-thione) (bbit) ligand. These compounds were characterized by IR, CHNS, PL, TGA, PXRD and their crystal structures were determined by X-ray crystallography. The final structure of synthesized polymers was affected by applied co-ligand and reaction conditions. Treating copper(I) iodide with equimolar ratio of bbit ligand afforded 1D wavelike polymer 1 with a distorted trigonal planar geometry by branched tube method. Polymer 2 has synthesized by the same starting material for 1 through unexpected process by solvothermal method with a distorted S4 tetrahedral environment. With addition of CN− to the reaction mixture of 1, 2D wavelike polymer of 3 with distorted trigonal CNS and tetrahedral CNS2 coordination environments was formed. Polymer 4 is analogue of 1 and was prepared by the same method as for 1 using copper chloride instead of copper iodide. The action of the title polymers on several pathogens were verified via antibacterial, MIC and MBC tests. The obtained results displayed that the polymers 1, 2 and 4 have bactericidal behavior, while the polymer 3 is a bacteriostatic agent.

International audience; This study shows the inactivation of antibacterial and dye removal in aqueous solution via photocatalysis with an easy fabrication route of silver deposited titanium dioxide/cobalt ferrite composite nanoparticles through a three-stage process applied under ultrasonic irradiation. An adsorption kinetic and equilibrium isotherm were investigated by four kinetic and five isotherm models. Then, photocatalytic potential and antibacterial activity were assessed, respectively, by photodegradation of cationic dye under UV light and four bacteria employing MIC and MBC indices coupled to SPM observation, which illustrated that the bactericidal effect is desirable to inhibit growth. Moreover, the nanocomposite can be easily isolated from the solution via magnetic decantation for removing catalytic pollutants.

This account describes our recent studies on zwitterionic mercury(II) complexes with two diphosphonium salts, [PPh2(CH2)nPPh2CH2C(O)C6H4Cl)]Br (n = 1 (S1) and 2 (S2)), derived from 1,2-bis(diphenyl-phosphino)methane (dppm) and 1,2-bis(diphenyl-phosphino)ethane (dppe). These complexes were synthesized through reactions between diphosphonium salts and HgX2 in equimolar ratio and characterized by elemental analysis, IR, 1H, 13C and 31P NMR spectroscopic methods. The structure of complex [HgI2Br(PPh2(CH2)2PPh2CH2C(O)C6H4Cl)] (6) was determined by a single crystal X-ray structural analysis. The results indicated that the mercury center in this complex is four-coordinated in a distorted tetrahedral configuration. The results confirmed that the coordination of ligand to metal occurred through the phosphine group (P-coordination mode). Furthermore, antibacterial/antifungal activities of the diphosphonium ligands and their complexes were tested against two Gram-negative bacteria Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 9027) and two Gram-positive bacteria Staphylococcus aureus (ATCC 6538) and Bacillus subtilis (ATCC 6633) as well as two fungi (Geotrichum sp. and Candida albicans). It seems that the chemical compounds reported herein may be used for control of pathogenic bacteria/fungi.

Herein, a competition between the different anions with different size, shape and coordination ability was used for the synthesis of three silver(I)-coordination polymers (Ag-CPs) was investigated. In this study, three 3D-supra-molecular coordination compounds namely, [Ag2L(NO3)2]n (1), {[Ag2L][PF6]2}n (2) and [AgLBr]n (3) (L = 1,1′-(1,5-pentadienyl)bis-(1,3-dihydro-3-methyl-1H-imidazole-2-thione)) have been synthesized and fully characterized via a single crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis (CHN), FT-IR spectra and thermo gravimetric analysis (TGA). Structural analysis revealed that the counter ions have a notable impact in directing the conformation and coordination mode of ligand, but they have no effect on the structural dimension of the polymers. Furthermore, by increasing the coordination ability of the anions, the coordination geometry of the AgI centers change, from a distorted linear (for 2) to a distorted square pyramidal coordination geometry (for 1). The chains are further stabilized by the intermolecular C H⋯O and C H⋯N for 1, P–F…H C for 2, C H⋯Br and C H⋯N interactions for 3 to form a 3D non-covalent lattice network structure. In contrast to the 1 and 3, polymer 2 exhibits a large capacity and selectivity to adsorb dye from aqueous solutions. Sorption kinetic was investigated by three kinetic models. The electronic band structure and the projection densities of states (PDOS) of compounds 1 and 3 were investigated by means of DFT-D3. The results demonstrated that both compounds are non-magnetic and show a semiconducting character with a direct band gap of ~3 eV. All of the synthesized compounds, possess antibacterial activity against the selected strain of Gram- negative (Escherichiacoli, Pseudomonas aeruginosa) and Gram- positive (Staphylococcus aureus, Bacillus subtilis) bacteria.

The feasibility of using a locally abundant bulking material (sugarcane bagasse) in Khuzestan province, Iran, to remove petroleum hydrocarbons from oil-based drill cuttings (OBDCs), using composting process, was investigated. OBDCs were collected from the discharge point of a drilling rig and bagasse was collected from a sugarcane agro-industry near Ahwaz. Experiments were performed in the dark and at room temperature, using different bagasse to OBDCs ratios. Degradation extent and kinetics of total petroleum hydrocarbons (TPHs) and poly aromatic hydrocarbons (PAHs), as well as dehydrogenase and urease enzymes activities and number of heterotroph bacteria during the co-composting of OBDCs and bagasse were studied and measured. Highest PAHs and TPH removals were observed when OBDCs were composted with 15% bagasse. After 70 days of incubation, PAHs and TPH were removed up to 24.8% and 67.5%, respectively. Studying the enzymes activities and number of heterotrophs with TPH and PAHs concentrations over time suggests that biodegradation is the main mechanism in the degradation process. The first-order kinetic model was fitted to the TPH and PAHs degradation data and contaminants half-lives were estimated to be in the range of 40–80 and 170–240 days respectively. DT90 values for TPH and PAHs were in the range of 120–260 and 560–1260 days, depending on the bagasse content.

The Fars geological province is located in the southern part of the Zagros belt, which extends from the Kazerun fault zone to the Strait of Hormuz and is marked mostly by emergent Hormuz salt plugs and east–west structural trends. The sedimentary succession in the Zagros is 10–14 km thick resting on the metamorphic basement. Main detachment horizons in the Fars geological province are Hormuz salt, with the basal detachment horizon and evaporites of the Dashtak formation as the intermediate detachment layer. The structure of the Fars geological province is a result of the interaction of the Zagros orogeny and Hormuz salt diapirism. The geometrical characteristics of the folded structures change dramatically across the north–south trending Fars High. In the central Fars area, variations in the mechanical stratigraphy inherited from basement geometry are the main reason behind this difference in structural style. The folding style in the Fars geological province also is significantly affected by the interaction of the Hormuz salt diapirism and tectonics associated with the Zagros orogeny. The preexisting diapirs of the Hormuz salt controlled the spatial distribution, shape, size, and orientation of folds.

Introduction: Staphylococcus aureus enterotoxins play an important role in the incidence of food poisoning and various other syndromes are occurred such as staphylococcal scalded skin syndrome and toxic shock syndrome. Objectives: The purpose of the present study was to investigate the frequency of enterotoxin B and C genes among S. aureus isolates from clinical samples obtained from inpatients of a hospital by polymerase chain reaction (PCR). Materials and Methods: This cross-sectional study conducted during the period July to December 2015. Clinical samples including blood, urine, wounds and nasal mucosa samples were collected from a hospital in Ahvaz, southwest of Iran and screened for S. aureus strains by several phenotypic and biochemical tests. A total of 132 clinical samples were collected from which 60 samples were infected with the S. aureus strains. Then PCR assay was carried out to determine the entB and entC genes prevalence among these isolates. Results: Molecular analysis revealed that only 8 (13.3%) isolates harbored the entB and/or entC genes. Five strains (8.3%) contained only entB gene, 2 strains (3.3%) contained entC gene and only one strain (1.7%) was simultaneously positive for both entB and entC genes. There was no significant difference among various age groups regarding enterotoxin genes (P=0.551). Conclusion: These results demonstrated that enterotoxin-producing strains have a relatively low incidence in clinical samples in understudy hospital, but monitoring of their prevalence is necessary in regular screening programs in order to find the possible increase in their prevalence and prevention of their outcomes.

Nanoparticles due to their unique properties have attracted more attention and their bacterial biosynthesis is more favorable because is environmental friendly and the size and yield of nanoparticles can be optimized. The aim of the present study was biosynthesis of Selenium nanoparticles using Bacillus cereus. For this purpose, bacterial culture was prepared in the presence of sodium selenate solution and incubated (30°C, 24 h). The produced nanoparticles were purified through consequent centrifugation, washing with 0.9% NaCl, sonication, washing with Tris- HCl containing Sodium dodecyl sulfate (SDS) and finally isolation with water- octanol two phase systems. Then using Ultraviolet-Visible spectroscopy, dynamic light scattering (DLS), scaning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, nanoparticle production was confirmed. The bioavailability of nanoparticles was also investigated in rat. As a result of this study spherical selenium nanoparticles with a mean diameter of 170 nm were biosynthesized. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of selenium for Bacillus cereus were same and equal to 75mM. Absorption and secretion of nanoselenium was significantly higher than bulk Selenium (P

Two new diorganotin(IV) complexes, Me2SnL and Ph2SnL, have been synthesized from the reaction of Me2SnCl2 and Ph2SnCl2 with the hydrazone H2L [H2L = (Furan-2-yl) (5-hydroxy-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)-methanone] derived from furan-2-carbohydrazide and benzoylacetone. The new compounds have been characterized by elemental and spectroscopic analyses. The crystal structures of the monohydrate form of the ligand and of the Me2SnL derivative have been also determined by X-ray crystallography. Experimental evidences confirm the existence of the hydrazone ligand exclusively in cyclic form in both solution and solid state. On coordination to tin the hydrazone undergoes a ring opening reaction and a doubly deprotonation to act as a tridentate ligand via imine nitrogen and enolic oxygens. The tin atom in the complexes is five coordinate with geometry between square-pyramidal and trigonal-bipyramidal. The in vitro antibacterial activity of ligand and its complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The interaction between compounds with bacterial DNA was also studied by molecular docking. Our findings indicate that diphenyltin(IV) complex, by binding to DNA via minor groove to TATA sequence in genes upstream, has good activities along with the standard antibacterial drugs. Our agarose-gel electrophoresis experiments show that the ligand exert DNA cleavage, while Me2SnL and Ph2SnL did not.

The reaction of mercury(II) halides with the phosphine–phosphonium salts [PPh2(CH2)2PPh2CH2C(O)C6H4R]Br (R = Br (S1), NO2 (S2) in methanol affords the zwitterionic mercury(II) complexes {HgX2Br(PPh2(CH2)2PPh2CH2C(O)C6H4R)} [R = Br: X = Cl (1), Br (2), I (3); R = NO2: X = Cl (4), Br (5), I (6)]. These complexes were fully characterized by elemental analysis and spectroscopic techniques such as IR, 1H, 31P, and 13C NMR. The structure of complex 4 has been characterized crystallographically. Single crystal X-ray analysis reveals the presence of mononuclear P-coordinated complex containing Hg(II) in a distorted tetrahedral environment. Theoretical studies using density functional theory have been performed on the free ligands (S1 and S2) and their corresponding complexes (1–6). Electronic and structural properties of latter compounds were examined and general trends were derived. The natural bonding orbital calculations have also been carried out to understand the nature of the Hg–P bond. The results show that the interactions between the metal atom and phosphorus atom of phosphine group are mainly an electrostatic interaction. In addition, there is a decrease in the charge distribution on the ligand reflecting electron transfer from the ligand to the metal and halogens atoms. The in vitro antibacterial activities of the entitled compounds were evaluated against Gram-negative as Escherichia coli and Pseudomonas aeruginosa bacteria and Gram-positive as Bacillus subtilis and Staphylococcus aureus and compared with the standard antibacterial drugs.

In this research, we report a straightforward route for the synthesis of a cationic supramolecular structure via covalently anchoring an ionic liquid-containing pyridinium moiety onto c-methylcalix[4]resorcinarene. Antibacterial activity of the new functionalized c-methylcalix[4]resorcinarene was evaluated against Gram-positive and Gram-negative bacteria. Surprisingly, this compound exhibited a selective antibacterial effect on Gram-positive bacteria, which is very important from the industrial and medicinal point of view. These preliminary results are attractive for the development of a new antibacterial agent.

Metal nanoparticles are one option for targeted drug delivery. In order to increase antibiotic efficiency and decrease its side effects, antibiotic conjugated nanoparticles have been known as a suitable approach. The aim of this study was optimization of gold nanoparticle biosynthesis byEscherichia coliDH5α and its conjugation with gentamicin. For this purpose gold nanoparticles were biosynthesized from HAuCl4and confirmed by Uv/ Vis, XRD, DLS and SEM. Then the effects of different parameters on optimum conditions for gold nanoparticles production were investigated. The MIC and MBC of gentamicin and its conjugate were investigated againstE. coli,Clostridium perfringensandClostridium botulinum. The results revealed that among different treatments, centrifuge (10000 rpm, 10 min) and sonication are the optimum conditions for gold nanoparticle production with less than 10 nm sizes. Filtration was also the best method for purifying nanoparticles. The conjugated nanoparticles significantly reduced the MIC of gentamicin againstE. coliand also overcame the natural resistance of tested anaerobic bacteria. In conclusion, the optimized method is an effective, inexpensive and environmental friendly method for biosynthesis of gold nanoparticles. Overcoming natural resistance of anaerobic bacteria using antibiotic conjugates with nanoparticles provides hopes for further experiments and in vivo studies.

In the present contribution, we have described a facile fabrication of silver-deposited silanized cobalt ferrite composite (CoFe2O4/SiO2/Ag) through a three-step procedure. A pre-synthesized CoFe2O4 was first coated with silica using Stober method and then silver nanoparticles were deposited onto the surface of silica shell. After characterization of this three-component composite by various techniques, such as FT-IR, XRD, SEM, EDX, TEM and VSM, it was impregnated with streptomycin antibiotic. The antibacterial activity of CoFe2O4/SiO2/Ag alone and in combination with streptomycin was investigated against some Gram-positive and Gram-negative bacteria employing disc diffusion assay. It was observed that the bactericidal effect of this composite, evaluated through the diameter of inhibition zones, was enhanced in combination with streptomycin. This clearly indicates synergistic effect of streptomycin on CoFe2O4/SiO2@Ag composite. The present study has demonstrated that the newly synthesized CoFe2O4/SiO2/Ag composite, when combined with streptomycin, becomes an excellent antibacterial agent. The as-made composite can be readily isolated from aqueous solution via magnetic decantation avoiding contamination of the environment.

Background: Infections due to resistant Staphylococcus aureus strains are progressively increased annually. So, finding new antibiotic resources is of great importance. Medicinal plants as a natural source of antibiotics are considered a good option. Teucrium polium, a native plant in Khouzestan, has been used for a long time in folk medicine. The aim of the present study was to investigate the antibacterial potential of this plant against methicillin resistant S. aureus (MRSA) strains. Methods: Methanolic extract was prepared from the flowers of T. polium, and its antibacterial activity was evaluated against 50 MRSA isolates by Kirby-Bauer disc diffusion method. These isolates were also screened for mec and pvl genes. Results: From 50 isolates, 20 isolates were selected and subjected to antibacterial analysis. From these, 14 isolates were positive for mecA gene, 2 of them were positive for pvl gene and 4 of them didn't have mec or pvl genes. None of MRSA isolates were positive for both genes. The results showed that the methanolic extract of T. polium has considerable inhibitory effect against MRSA, even at the lowest concentration. mecA and pvl negative strains were more sensitive to methanolic extract, but the presence of mecA didn not have any significant effect on their resistance. Conclusion: Based on these findings and with regard to the increasing trend in hospital-acquired S. aureus infections, it can be suggested that T.polium is an effective medicinal plant for treatment of infections caused by this bacterium and can be used as a natural source to produce new antibiotics.

The microbiological quality of drinking water has long been a critical element in public health. Considering the high clinical relevance of Pseudomonas aeruginosa, we examined the filters of household water treatment systems for its presence and characteristics to determine the systems' efficiency in eliminating the bacteria. In total, filters of 50 household water treatment systems were examined. Microbiological and molecular methods were used for the detection and confirmation of P. aeruginosa isolates. Random Amplification of Polymorphic DNA-polymerase chain reaction (RAPD-PCR) was performed to detect similarities and differences among P. aeruginosa isolates. Combined disk (CD) method and double disk synergy test (DDST) were performed to detect metallo-beta-lactamase (MBL)-producing P. aeruginosa isolates. Finally, PCR was performed to detect MBL genes in MBL-producing strains. From the 50 analyzed systems, 76 colonies of P. aeruginosa were identified. In some systems, isolated bacteria from different filters harbored similar genetic profiles, indicating that these isolates may be able to pass through the filter and reach higher filters of the system. Phenotypic tests revealed 7 (9.2%) MBL-producing strains. Two isolates were positive for blaVIM-1, whereas one isolate was positive for blaNDM and blaIMP-1. The wide distribution of resistant phenotypes and genetic plasticity of these bacteria in household water treatment systems indicate that resistance mechanisms circulate among P. aeruginosa isolates in the environment of the filtration systems. The presence of MBL-producing genes in these systems and P. aeruginosa as a potential reservoir of these resistance genes can be a major concern for public health.

A three-component composite consisted of graphene oxide, cobalt ferrite, and silver nanoparticles has been prepared by a facile method and fully characterized. The antibacterial activity of this composite has been greatly enhanced after being combined with ciprofloxacin drug. This clearly showed the occurrence of a strong synergistic effect between ciprofloxacin and the Ag NPs in the composite. The ciprofloxacin-conjugated composite was found to be a potent antimicrobial agent while having rather low cytotoxicity and high stability. The studies based on field emission scanning electron microscopy (FESEM) analysis and zeta potential measurement have revealed that the composite sticks to the bacterial cell wall causing irreversible cell damage. This multifunctional magnetic nanocomposite was also examined as drug delivery system for ciprofloxacin in solutions with different pH. It was observed that the release of ciprofloxacin in this system is pH-sensitive with gradual and controlled manner. Mechanisms for the synergistic effect and drug release behavior, as well as explanation for the antibacterial action, of the nanocomposite were also demonstrated.

Background: With regard to the rapid emerging antibiotic resistance bacteria, plants as one of the most common natural sources of antimicrobial agents can be used as alternative for treatment of infectious diseases. This study was designed to investigate antibacterial activity of Mentha pulegium L. (Lamiaceae family). Materials and Methods: In this experimental study, the antibacterial effect of 4, 8, 16 and 24 mg/disc of alcoholic extracts were assessed using standard disc diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. Furthermore, the structural changes following to the exposure with these extracts were also investigated in test bacteria. Results: Both extracts of this plant showed considerable antibacterial activity against some Gram positive (Bacillus cereus and Staphylococcus aureus) and also Gram negative (Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis) bacteria. All of the tested bacteria were resistant to nafcillin. The maximum effects was observed in the case of both ethanolic and methanolic extracts in all concentrations on P. mirabilis (25 mm) and the lowest effect was on P. aeruginosa. MIC and MBC values of both extracts against S. aureus were equal (MIC=MBC=8 mg/mL) and P. mirabilis were MIC=4 mg/mL and MBC=8 mg/mL. The SEM analysis revealed deformation and cell wall disruption of affected bacteria. Conclusion: Based on these results it can be suggested that M. pulegium L. is an effective antibacterial plant that can be used as a new source for antibiotic discovery against bacterial pathogens especially food poisoning pathogens such as S. aureus, B. cereus and also for treatment of P. mirabilis infection.

A new magnetically responsive three-component nanocomposite consisting of CoFe2O4, polyaniline (PANI) and nanosilver has been prepared by coating of CoFe2O4 nanoparticles with PANI and subsequent immobilization of silver nanoparticles onto the surface of the polyaniline shell. The as-prepared CoFe2O4/PANI/Ag nanocomposite has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Inlaying the pre-synthesized CoFe2O4/PANI composite with silver nanoparticles enhances its electrical conductivity as well as its catalytic and antibacterial activities. The CoFe2O4/PANI/Ag nanocomposite shows good antibacterial activity against some Gram-positive and Gram-negative bacteria. Although the saturation magnetization of the CoFe2O4 core decreases significantly on coating with PANI and nanosilver shells, the CoFe2O4/PANI/Ag nanocomposite can be still separated from water solution through magnetic decantation.

The new diorganotin(IV) complexes R2SnL (L = La: R = Me 1, Ph 2; L = Lb: R = Me 3, Ph 4, L = Lc: R = Me 5, Ph 6, Bu 7) have been synthesized by the reaction of the hydrazone ligands N′-(5-bromo-2-hydroxybenzylidene) isonicotinohydrazide (H2La), N′-((2-hydroxynaphthalen-1-yl)methylene) isonicotinohydrazide (H2Lb) and N′-(2,4-dihydroxybenzylidene) isonicotinohydrazide (H2Lc) with diorganotin(IV) dichloride. The synthesised compounds have been investigated by elemental analysis, together with IR, 1H and 119Sn NMR spectroscopy. The structures of H2La, H2Lb and 3 have also been confirmed by X-ray crystallography. On the basis of these data, H2La and H2Lb are present in the keto-amine tautomeric form and intermolecular N–H⋯N hydrogen bonds form 1D chain structures. The hydrazone ligands act as tridentate dibasic in the enol form and are coordinated via the imine nitrogen, phenolate and enolate oxygen atoms. The in vitro antibacterial activity of the ligands and their complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and compared with standard antibacterial drugs. The R2SnLc complexes exhibited greater activities than the other compounds.

A new three-component and magnetically responsive NiFe2O4@PANI@Ag nanocomposite has been fabricated by coating of nickel ferrite, NiFe2O4, nanoparticles with polyaniline (PANI) and subsequent immobilization of silver nanoparticles onto the surface of polyaniline shell. The as-prepared nanocomposite has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The saturation magnetization of the NiFe2O4 core decreases dramatically after coating with polyaniline and silver nanoparticles, however, the nanocomposite NiFe2O4@PANI@Ag can be still separated from solution media through magnetic decantation. The antibacterial activity of the synthesized nanocomposite was studied and compared with those of naked NiFe2O4, NiFe2O4@PANI and some standard antibacterial drugs.

Two new mercury (II) polymeric complexes namely, [Hg2(µ-bbit)Cl4]n (1) and [Hg(µ-bbit)(SeCN)2]n (2) [bbit = 1,1-(1,4-butanediyl)bis(1,3-dihydro-3-methyl-1H-imidazole-2-thione] have been successfully synthesized and characterized by the single crystal X-ray diffraction analysis, IR, CHNS, PXRD and TGA. X-ray analysis shows that reaction of the bbit ligand with HgCl2 leads to the formation of 2D honeycomb coordination polymer of 1. Polymer 2 with an unpresented 1D wave-like structure was prepared by addition of selenocyanate to the reaction mixture of polymer 1. In both complexes, the coordination geometry about each mercury atom can best be described as trigonal pyramidal with core structures of HgCl3S (for 1) and HgSe2S2 (for 2) and the bbit ligands adopt a bridging mode through two sulfur atoms between the mercury atoms. The title polymers are further stabilized by the intermolecular hydrogen bonds to form a 3D polymeric network structure. Their antibacterial and DNA cleavage activities were also evaluated. On the base of the obtained results, these compounds have a broad antibacterial activity against both Gram-positive and Gram-negative species, while the Gram-positive species were more effected with these polymers. It may suggest that the functional groups present in the envelope of these bacteria are the main target for S-donor sites in the considered compounds.