Search

In this study, three algae (Corallina officillica, Ulva lactuca, and Pterocaldia capallicia) and three aromatic herbs (Ocimum basilicum, Mentha longifoila, and Salvia officinalis) were investigated. Phytochemicals, P. capallicia had the highest total carbohydrate content (17.50%), while M. longifoila had the highest total proteins ratio (17.95%). Mentha longifoila possessed the maximum total lipids percent (32.14%), while C. officillica had the highest ash content (58.83%). As well as, M. longifoila had the highest phenolics and carotenoids values, while U. lactuca had the highest total flavonoids. To antioxidant activity estimated, the S. officinalis (M6) extract showed the highest scavenging activity (89.88%). Regarding antibacterial activities, the C. officillica extract exhibited the most powerful activity against P. aeruginosa ATCC 9027 (44 mm), followed by S. officinalis extract against the same bacterium (40 mm). The GC-MS assessment revealed the existence of several bioactive constituents, involving fatty acids, terpenoids, steroids, flavonoids, carotenoids, phenolic compounds, and other compounds. [ABSTRACT FROM AUTHOR]

The present study aims to search for a nano-delivery system that enables access of antimicrobial compounds to the targeting site of the microbial pathogens. To achieve this obiective, the antimicrobial compounds extracted from the local isolate Streptomyces rimosus were loaded on chitosan (CS) and calcium phosphate (CaP) nanoparticles (NPs) to facilitate drug delivery to some species of bacteria (Escherichia coli ATCC25922, Staphylococcus aureus ATCC25923 and Bacillus cereus ATCC6633) and the yeast Candida albicans ATCC10231. The best incubation period for the production of antifungal and antibacterial compounds, pH, temperature, carbon sources and nitrogen sources were around the third day, 7.0, 30°C, starch and potassium nitrate, respectively. The extracted compounds were identified using gas chromatography-mass spectrometry (GC-MS) analysis which revealed to the identification of nine antimicrobial organic acids. The prepared NPs were characterized using transmission electron microscopy (TEM) and Zeta potential analyser. Results showed those chitosan nanoparticles (CSNPs) were spherical shaped NPs with an average size ≈22 ± 2 nm. The CSNPs loaded with the antimicrobial molecule's diameter was ranged from 55 upto 100 nm. Calcium phosphates nanoparticles (CaPNPs) were also spherical shaped NPs with diameter range from 70 to 95 nm. Loading of antimicrobial compounds onto CaPNPs made them appeared in rod shape with width varying from 14 to 27 nm and length from 274 to 397 nm. The synthesized NPs showed negative values confirming their high dispersity and long-term stability. The tested strains were resistant to solo NPs; but the loaded NPs with the extracted antimicrobial compounds, particularly the CaPNPs, augmented the potency of the isolated antimicrobial compounds, with emergence of differential antimicrobial activity. The activity of the NPs-bound antimicrobial compounds was more evident against bacteria than fungi, Grampositive bacteria than Gram-negative bacteria and against B. cereus than S. aureus. [ABSTRACT FROM AUTHOR]

A novel series of mixed‐ligand complexes of 5,5′‐{(1E,1E′)‐1,4‐phenelynebis(diazene‐2,1‐diyl)}bis(quinolin‐8‐ol) (H2L1) as a primary ligand and 4‐aminoantipyrine(L2) as a secondary ligand with Mn(II) ion were prepared using two general formulae: [Mn2(H2L1)2(L2)2X4].4Cl (X = OH2(1), ONO2−(2), Cl=nil; OAc(3), Cl = nil) and [Mn2(H2L1)(L2)2(O2SO2)2](4). Free ligands and their complexes were characterized. Electronic absorption spectra of the mixed‐ligand complexes indicate a distorted octahedral geometry around the central metal ion, and the anions X− are in the axial positions for all compounds. The ligands behave in a neutral bidentate manner, through nitrogen atoms and oxygen atoms of the carbonyl group (L2), whereas H2L1 coordinated through nitrogen and OH groups as a neutral bidentate ligand. All complexes do not contain coordinated water molecules, but complex (1) contains four water molecules. The water molecules are removed in a single step. The complexes exhibited magnetic susceptibility corresponding to five unpaired electrons. The antimicrobial activity of the Mn(II) mixed‐ligand complexes (1–4) against two gram‐positive bacteria, three local gram‐negative bacteria, and three fungi species was tested. Mn(II) mixed‐ligand complex (2) exhibited significant antibacterial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas sp. Mixed‐ligand complex (2) exhibited a high potential cytotoxicity against the growth of human lung cancer cells. [ABSTRACT FROM AUTHOR]

AmyLa α-amylase gene from Laceyella sp. DS3 was heterologously expressed in E. coli BL21. E. coli BL21 maximally expressed AmyLa after 4 h of adding 0.02 mM IPTG at 37 °C. The recombinant AmyLa α-amylase was purified 2.19-fold through gel filtration and ion exchange chromatography. We immobilized the purified recombinant AmyLa α-amylase on four carriers; chitosan had the best efficiency. The recombinant free and the immobilized AmyLa α-amylase showed optimum activity in the pH ranges of 6.0–7.0 and 4.0–7.0, respectively and possessed an optimum temperature of 55 °C. The free enzyme had activation energy, Km, and Vmax of 291.5 kJ, 1.5 mg/ml, and 6.06 mg/min, respectively. The immobilized enzyme had activation energy, Km, and Vmax of 309.74 kJ, 6.67 mg/ml, and 50 mg/min, respectively. The immobilized enzyme was calcium-independent and insensitive (relative to the free enzyme) to metals. It could also be reused for seven cycles. [ABSTRACT FROM AUTHOR]

α-Amylase (AmyLa) from Laceyella sp. DS3 was purified 13.8-fold by ammonium sulfate precipitation, gel filtration, and ion exchange chromatography. The purified AmyLa showed an optimum pH of 7 and an optimum temperature 55°C. It had activation energy, Km, and Vmax of 196.1 kJ, 0.81 mg/mL, and 2.85 mg/min, respectively. Co2+, Cu2+, Hg2+, and Na+ were strong inhibitors of AmyLa whereas Cl- was an activator. Although AmyLa is a Ca2+ independent α-amylase, it was activated by Ca2+. The AmyLa gene encoding α-amylase activity was sequenced. It revealed putative triple promoters and an open reading frame of 1449 bp (483 amino acids) including a 29 amino acid putative signal peptide. AmyLa was shown to possess four conserved sequence regions of the GH13 family. Polyacrylamide gel electrophoresis identified 69.2 and 72.5 kDa proteins whose α-amylase activities were confirmed by native gel staining. Modeling of AmyLa revealed three domains A-C with domain A containing a catalytic (α/β)8 barrel. Phylogenetic and evolutionary tree analysis suggests that AmyLa might be have been transferred from fungi to an ancient thermoactinomycete ancestor, then adapted to bacterial genome features. [ABSTRACT FROM AUTHOR]

Silver nanomaterials are usually applied as antimicrobial agents; however, they can cause toxic effects on human health. The current investigation was performed to study the combined effects of chitosan and silver nanoparticles (AgNPs) using the cell-free supernatant of Escherichia coli (MF062579). The produced chitosan/silver nanocomposite (CS/AgNC) showed good antibacterial activity and high stability. The biosynthesized CS/AgNC contained homogeneous spherical AgNPs with an average size of ~12.3 nm and a net surface charge of +30.9 ± 3.2 mV. CS/AgNC revealed a good minimum inhibitory concentration (MIC) result against Gram-negative (G-ve, E. coli) and Gram-positive (G+ve, Bacillus cereus) bacteria with inhibition ratios of 80.7% and 75.5%, respectively. Nanocomposite-treated cells displayed complete lysis of the bacterial cell, a low amount of DNA, and cell membrane and wall disruption. Glutamate dehydrogenase (GDH) and malate dehydrogenase (MDH) activities of tested bacterial strains were demonstrated using spectrophotometry and electrophoresis on a non-denaturing acrylamide gel. In CS/AgNC-treated strains, enzyme production and activity were fewer than in untreated strains. The obtained results suggested that CS/AgNC seems to be more effective against G-ve than G+ve bacteria. [ABSTRACT FROM AUTHOR]

Central composite design (CCD) as one of response surface designs was employed to optimize the biosynthesis process of silver nanoparticles (AgNPs). In this design, fungal cell-free filtrate of Talaromyces stipitatus was applied as a biosource for the biosynthesis of AgNPs. Different variables with five levels were used to optimize AgNPs biosynthesis. Independent variables were concentration of silver nitrate (AgNO3; mmole), temperature (°C), time, pH and ratio of AgNO3 to cell free extract. While dependent variable was peak intensity of surface plasmon resonance (SPR) at wavelength 420 nm. The predicted optimal setup parameters were AgNO3 concentration of 7 mmol, temperature of 25 °C, time of 91.2 hr, pH of 8 and ratio of AgNO3 solution to cell-free extract of 2:1. The characteristics of biosynthesized AgNPs were revealed using Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), zeta potential, energy dispersive x-ray analysis (EDX), and transmission electron microscopy (TEM). Biosynthesized AgNPs appeared to be spherical, with mean size of 13.95 nm and zeta potential of 9.85 mV. Biosynthesized AgNPs were also examined for their antimicrobial properties against selected bacterial and fungal pathogens including Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Aspergillus flavus, A. niger, Fusarium oxysporum and Alternaria alternata. [ABSTRACT FROM AUTHOR]

Characterization of bacteriophages facilitates better understanding of their biology, host specificity, genomic diversity, and adaptation to their bacterial hosts. This, in turn, is important for the exploitation of phages for therapeutic purposes, as the use of uncharacterized phages may lead to treatment failure. The present study describes the isolation and characterization of a bacteriophage effective against the important clinical pathogen Escherichia coli, which shows increasing accumulation of antibiotic resistance. Phage fEg-Eco19, which is specific for a clinical E. coli strain, was isolated from an Egyptian sewage sample. Phage fEg-Eco19 formed clear, sharp-edged, round plaques. Electron microscopy showed that the isolated phage is tailed and therefore belongs to the order Caudovirales, and morphologically, it resembles siphoviruses. The diameter of the icosahedral head of fEg-Eco19 is 68 ± 2 nm, and the non-contractile tail length and diameter are 118 ± 0.2 and 13 ± 0.6 nm, respectively. The host range of the phage was found to be narrow, as it infected only two out of 137 clinical E. coli strains tested. The phage genome is 45,805 bp in length with a GC content of 50.3% and contains 76 predicted genes. Comparison of predicted and experimental restriction digestion patterns allowed rough mapping of the physical ends of the phage genome, which was confirmed using the PhageTerm tool. Annotation of the predicted genes revealed gene products belonging to several functional groups, including regulatory proteins, DNA packaging and phage structural proteins, host lysis proteins, and proteins involved in DNA/RNA metabolism and replication. [ABSTRACT FROM AUTHOR]

This study highlights the optimization of extracellular biosynthesis and antimicrobial efficiency of silver nanoparticles (AgNPs) using the crude metabolite of Escherichia coli D8 (MF06257) strain. The bacterial strain had been isolated from a sewage water stream located in Damietta City, Egypt. The optimum conditions for AgNPs production were at temperature 35°C, pH 7 and 1.5mM silver nitrate. The AgNPs biosynthesis was detected in culture filtrate within 1-2 minutes at room temperature (25±2°C) and sunlight. The characterization of AgNPs was studied by UV-Vis spectroscopy (maximum absorbance at 429 nm), X-ray diffraction (XRD) pattern (crystal planes were 110, 111, 200, 211, 220, and 311), transmission electron microscopy (TEM) (AgNPs were spherical in shape ranging from 6 to 17 nm), Fourier transform-infrared (FTIR) spectroscopy (the bands of symmetric and asymmetric amines were assigned at 3421.1 and 2962.13 cm-1, the stretching vibration band of aromatic and aliphatic (C-N) exist at 1392.35 and 1122.37 cm-1 bands), Zeta potential analyser (AgNPs had a negative charge value; -33.6 mV) and size distribution by volume (the presence of capping agent enveloping the AgNPs with a mean size of 136.0-294.3 nm). Nitrate reductase (NR) was assayed as an important partner in the optimized production (the rate of NR reached to 2.18 U/ml). The study demonstrated that AgNPs are potent inhibitors of Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, Alternaria alternata, Fusarium oxysporum and Aspergillus flavus. The antimicrobial activity of AgNPs was studied by TEM. TEM micrographs showed an inhibition of S. aureus cell multiplication. In case of F. oxysporum, a reduction in the size of treated cells, formation of a mucilage matrix connecting the hyphal cells together, the appearance of a big vacuole, lipid droplets an a severe leakage of cytoplasmic contents were detected. AgNPs exhibited MIC values of 6.25μg/ml and 50 μg/ml against S. aureus and Candida albicans, respectively. In addition, AgNPs showed synergy effects by their combination with fluconazole that increased fold areas especially against A. niger, A. flavus and F. oxysporum. [ABSTRACT FROM AUTHOR]

Residents in many developing countries store treated drinking water in tanks or reservoirs because of intermittent and infrequent water supplies. Many studies have focused on bacterial contamination of domestic reservoir waters, the cyanobacterial and algal contamination is largely unexplored. Therefore, the present study investigates toxic cyanobacteria and their microcystin (MC) toxins in some domestic water storage reservoirs in Egypt as an example for developing countries. Three phytoplankton groups including cyanobacteria, green algae and diatoms were found in domestic reservoirs. Among these species, the toxic cyanobacterium Microcystis aeruginosa had the highest cell density during warm months (4.2-5.92 cells ? 106 L-1). This cell density increased along the time, indicating that environmental conditions in these reservoirs promoted the proliferation of this species. Intra- and extracellular MCs were also detected in reservoir waters at concentrations of 3.5-40 and 1-7.6 µg L-1, respectively, exceeding the WHO guideline limit of 1 µg L-1 for these toxins in drinking water. Heterotrophic bacteria were found in association with cyanobacteria in reservoir waters. The study suggests that treated-water storage reservoirs should be monitored for the presence of toxic cyanobacteria to protect the public from exposure to their potent toxins. [ABSTRACT FROM AUTHOR]

Conventional antifungal agents have failed to treat several infectious diseases of many Aspergillus strains. These strains have been linked to the production of high-potency mycotoxins, which cause mould diseases on fruits and vegetables and have negative health consequences. The current study aimed to develop new effective nanomaterials using efficient methods that were stable and antifungal. The current work has been carried out to use the free cell supernatant of Escherichia coli D8 (MF062579) in the biosynthesis of reduced graphene oxide/silver nanocomposite (rGO/AgNC). At room temperature, the nanocomposite was prepared by an economical and simple one-step approach. Different parameters were optimized in the biofabrication of rGO/AgNC such as silver nitrate concentration, bacterial supernatant concentration, pH value, and temperature. Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Zeta analyses were used to evaluate the optimized rGO/AgNC. The biosynthesis process was performed within minutes in the incidence of solar irradiation. The mean size of silver nanoparticles (AgNPs) was estimated to be 9-18 nm. The biogenesis of spherical-shaped, well-dispersed AgNPs was validated by TEM images. AgNPs have a positive potential value, as seen by the zeta potential graph. rGO/AgNC had a harmful effect on the ultrastructure of rGO/AgNC-treated Aspergillus including membranes damage, malformation, and complete lysis of fungal cells in addition to enzymatic inhibition in lactate dehydrogenase activity. This study states a well-designed approach to develop a new antimicrobial agent, rGO/AgNC, against pathogenic human and phytopathogenic Aspergillus spp. in addition to a probable mechanism for the nanomaterial’s antimicrobial action. [ABSTRACT FROM AUTHOR]

Cu (II), Ni (II), Co (II), and Mn (II) acetato in addition to Cu (II) chloro and nitrato mixed ligand complexes of 4‐([quinolin‐2‐yl]methyleneamino)‐1,2‐dihydro‐2,3‐dimethyl‐1‐phenylpyrazol‐5‐one (L), as a primary ligand and 2,4‐dihydroxy benzaldehyde (H2L), as a secondary ligand have been isolated. The structural features and geometrical arrangements of the synthesized mixed ligand complexes were identified by elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), conductivity measurements, UV‐Vis spectra, magnetic moment measurements, X‐ray diffraction, and electron spin resonance (ESR) spectral and thermogravimetric techniques studies of the mixed ligand complexes confirming the molar ratio 1:1:1 (primary ligand: M: secondary ligand) for Cu (II), Co (II), Mn (II), and UO2(II) chelates. The spectral techniques also confirmed the metal chelates have the formulae (Cu[H2L][L][X]2), where X = Cl− (1); NO3− (2); and (M[L][HL][OAc])YH2O, where M = Cu (II) (3), Co (II) (4); Y = 1, Mn (II) (5); Y = 1 and UO2(II) (6); Y = 2. The kinetic and thermodynamics parameters of the mixed ligand complexes at different decomposition steps were calculated using Coast‐Redfern and Horowiz‐Metzger methods. Also, the antimicrobial activities of ligands and their mixed ligand complexes were screened by Disc Diffusion method. It was found that all mixed ligand complexes (1–6) have high antibacterial activity against Klebsiella pneumoniae than penicillin G. By studying the molecular docking between the quinoline‐2‐carbaldehyde, the ligand and the receptors (Escherichia coli (PDB code: 3t88), Staphylococcus aureus (PDB code: 3q8u), lung cancer (PDB code: 1x2j), and colon cancer (PDB code: 2hq6)), it was found that the ligand is efficient compound for all the receptors than the quinoline‐2‐carbaldehyde. The DNA cleavage properties of the two ligands and their complexes have been investigated by gel electrophoresis and the results showed that complex (1) without H2O2 and complex (6) with H2O2 exhibited a significant partial oxidative cleavage among other complexes. [ABSTRACT FROM AUTHOR]

Metal complexes of Schiff base ligand 4‐((Z)‐(4‐nitrophenylimino)methyl)benzene‐1,3‐diol (H2L) derived from condensation of 2,4‐dihydroxybenzaldehyde and p‐nitroaniline were synthesized and characterized by elemental analysis, IR, 1H NMR spectra, magnetic moment, molar conductance, and ultraviolet (UV)–Visible and thermal analysis. The complexes were proposed to have the formula [M (HL)(OAc)2] where M = Cu (II), Co(II), Ni(II), Mn(II), and Cd(II). The Fourier transform infrared (FT‐IR) spectra showed that ligand is coordinated to the metal ions in bidentate manner with donor sites of the azomethine‐N, phenolic‐OH. The synthesized Schiff base ligand and its metal complexes (1)–(5) were screened for their antibacterial activity. Antifungal activities were determined against Fusarium oxysporum, Aspergillus niger, and Candida albicans. Complex (5) showed a high potential cytotoxic activity against growth human lung cancer tumor cell lines. The DNA cleavage properties of the ligand and its complexes have been investigated by gel electrophoresis whose results showed that the Cu(II) complex has a significant oxidative cleavage among other complexes. Addition of H2O2 to the cleavage reaction enhanced the complete DNA degradation for Cu(II) and Co(II) complexes and DNA cleavage for Mn(II) complex. Molecular docking study between the ligand and the receptors (Escherichia coli [3t88], Staphylococcus aureus [3q8u], prostate cancer [2q7l Hormone], breast cancer [1jnx Gene regulation], lung cancer [1x2j], and colon cancer [2hq6]) was carried out, and it was found that the ligand is an efficient compound for all these receptors. [ABSTRACT FROM AUTHOR]

Background: Hypertrophy of the nucleolus is a distinctive cytological feature of malignant cells and corresponds to aggressive behaviour. This study aimed to identify the key gene associated with nucleolar prominence (NP) in breast cancer (BC) and determine its prognostic significance.Methods: From The Cancer Genome Atlas (TCGA) cohort, digital whole slide images identified cancers having NP served as label and an information theory algorithm was applied to find which mRNA gene best explained NP. Dyskerin Pseudouridine Synthase 1 (DKC1) was identified. DKC1 expression was assessed using mRNA data of Molecular Taxonomy of Breast Cancer International Consortium (METABRIC, n = 1980) and TCGA (n = 855). DKC1 protein expression was assessed using immunohistochemistry in Nottingham BC cohort (n = 943).Results: Nuclear and nucleolar expressions of DKC1 protein were significantly associated with higher tumour grade (p < 0.0001), high nucleolar score (p < 0.001) and poor Nottingham Prognostic Index (p < 0.0001). High DKC1 expression was associated with shorter BC-specific survival (BCSS). In multivariate analysis, DKC1 mRNA and protein expressions were independent risk factors for BCSS (p < 0.01).Conclusion: DKC1 expression is strongly correlated with NP and its overexpression in BC is associated with unfavourable clinicopathological characteristics and poor outcome. This has been a detailed example in the correlation of phenotype with genotype. [ABSTRACT FROM AUTHOR]

The optimal conditions for the production of xylanase and peroxidase from Streptomyces sp. K37 were investigated. The production of xylanase and peroxidase increased during the growth phase of the cultures after 72 hours. This indicates that the productions of such enzymes are wholly growth associated in these organisms. The optimum pH for xylanase and peroxidase production from Streptomyces sp. K37 occurred at pH 8.0 and pH 7.0. The optimum temperature for xylanase and peroxidase production by Streptomyces sp. K37 occurred at 50°C and 40°C respectively. Oat spelt xylan was the best carbon source for the production of xylanase and peroxidase from Streptomyces sp. K37. The optimum concentration of ball milled straw for the production of xylanase from Streptomyces sp. K37 was 1.0%, while the concentration for the production of peroxidase was 0.20%. The optimal concentration of yeast extract and casamino acid for the production of xylanase and peroxidase from Streptomyces sp. K37 was found to be 0.2%. [ABSTRACT FROM AUTHOR]

Abstract: Background: The identification of native HCV antigens may prove very useful in the diagnosis and early treatment of HCV infection. Here, we aimed to identify and partially characterize a native HCV-NS4 antigen. Methods: The western blot, ELISA and immunohistochemical staining were used to identify the native antigen in sera and liver biopsies of HCV serotype 4 infected patients. Results: The native NS4 antigen was identified in serum at 27-kDa molecular weight, in addition to a lower ∼21-kDa antigen. The purified HCV antigen showed a polypeptide band at 27-kDa when analyzed by silver stained SDS-PAGE and a single peak at 7.6 min by capillary zone electrophoresis. The immunostaining pattern of hepatocytes was cytoplasmic with mainly coarse granular and diffuse pattern based on specific rabbit antisera to the native HCV antigen. A highly significant correlation (r =0.797, p <0.0001) was shown between serum concentrations of the HCV-NS4 antigen and HCV-RNA. Also, antigen detection rates were increased (p <0.05) with the progression of liver disease. Conclusion: A native HCV-NS4 antigen was identified and partially characterized as 27-kDa protein and the NS4 antigenemia based ELISA test can serve as a useful addition to HCV diagnostic methods, especially under field condition. [Copyright &y& Elsevier]

Acinetobacter baumannii is an opportunistic pathogen that presents a serious clinical challenge due to its increasing resistance to all available antibiotics. Phage therapy has been introduced recently to treat antibiotic-incurable A. baumannii infections. In search for new A. baumannii specific bacteriophages, 20 clinical A. baumannii strains were used in two pools in an attempt to enrich phages from sewage. The enrichment resulted in induction of resident prophage(s) and three temperate bacteriophages, named vB_AbaS_fEg-Aba01, vB_AbaS_fLi-Aba02 and vB_AbaS_fLi-Aba03, all able to infect only one strain (#6597) of the 20 clinical strains, were isolated. Morphological characteristics obtained by transmission electron microscopy together with the genomic information revealed that the phages belong to the family Siphoviridae. The ca. 35 kb genomic sequences of the phages were >99% identical to each other. The linear ds DNA genomes of the phages contained 10 nt cohesive end termini, 52–54 predicted genes, an attP site and one tRNA gene each. A database search revealed an >99% identical prophage in the genome of A. baumannii strain AbPK1 (acc. no. CP024576.1). Over 99% identical prophages were also identified from two of the original 20 clinical strains (#5707 and #5920) and both were shown to be spontaneously inducible, thus very likely being the origins of the isolated phages. The phage vB_AbaS_fEg-Aba01 was also able to lysogenize the susceptible strain #6597 demonstrating that it was fully functional. The phages showed a very narrow host range infecting only two A. baumannii strains. In conclusion, we have isolated and characterized three novel temperate Siphoviridae phages that infect A.baumannii. [ABSTRACT FROM AUTHOR]