scholarly journals Characterization of a bacteriophage from urban sewage obtained with the bacterium Staphylococcus aureus

2020 ◽  
Vol 10 (1) ◽  
pp. 20-24
Author(s):  
Anderson Luiz Pena da Costa ◽  
Antonio Carlos Freitas Souza ◽  
Rafael Lima Resque
Keyword(s):  
Host Range ◽  
Pathogenic Bacteria ◽  
Fragment Length Polymorphism ◽  
Bacterial Species ◽  
Pharmaceutical Product ◽  
Urban Sewage ◽  
Viral Host Range ◽  
Significant Attention

Bacteriophages are viruses of bacteria that have received significant attention in the last decades due to their potential as an alternative to the antibiotics, as well as their applicability in the selective control of bacterial species harmful to food. In this context, this work reports the partial results of a viral filtrate named P4CSa that was obtained with the bacterium Staphylococcus aureusand characterized by the viral host range and the restriction fragment length polymorphism technique. The results indicate that the phage P4CSa probably belongs to the order Caudovirales, it presents a polyvalent host range, and it can be preserved for the long term in the form of filtrated lysates stored at 4°C, suggesting that the phage P4CSa may have the potential for the development of a pharmaceutical product indicated for the biocontrol of pathogenic bacteria. Stamford Journal of Microbiology, Vol.10 (1) 2020: 20-24

scholarly journals Discovery and Characterization of Low-Molecular Weight Inhibitors of Erwinia tracheiphila

2020 ◽  
Vol 110 (5) ◽  
pp. 989-998
Author(s):  
Cláudio M. Vrisman ◽  
Loïc Deblais ◽  
Yosra A. Helmy ◽  
Reed Johnson ◽  
Gireesh Rajashekara ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
High Throughput Screening ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Bacillus Species ◽  
Erwinia Tracheiphila ◽  
Static Activity ◽  
Low Toxicity

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.

scholarly journals Recovery of Salmonella from biofilms in a headwater spring ecosystem

2011 ◽  
Vol 9 (3) ◽  
pp. 458-466 ◽  
Author(s):  
James P. Gaertner ◽  
Joseph A. Mendoza ◽  
Michael R. J. Forstner ◽  
Dittmar Hahn
Keyword(s):  
Pathogenic Bacteria ◽  
Chain Reaction ◽  
Selective Enrichment ◽  
Animal Wastes ◽  
San Marcos ◽  
Polymerase Chain ◽  
Spring Lake ◽  
Precipitation Events

Salmonellae are pathogenic bacteria often detected in waters impacted by human or animal wastes. In order to assess the fate of salmonellae in supposedly pristine environments, water and natural biofilm samples along with snails (Tarebia granifera) and crayfish (Procambarus clarkia) were collected before and up to 7 days following four precipitation events from sites within the headwater springs of Spring Lake, San Marcos, TX. The samples were analyzed for the presence of salmonellae by polymerase chain reaction (PCR) after semi-selective enrichment. Salmonellae were detected in one water sample directly after precipitation only, while detection in ten biofilm and two crayfish samples was not related to precipitation. Salmonellae were not detected in snails. Characterization of isolates by rep-PCR revealed shared profiles in water and biofilm samples, biofilm and crayfish samples, and biofilm samples collected 23 days apart. These results suggest that salmonellae are infrequently washed into this aquatic ecosystem during precipitation runoff and can potentially take up residency in biofilms which can help facilitate subsequent long-term persistence and eventual transfer through the food chain.

scholarly journals Characterization of novel bacteriophage phiC119 capable of lysing multidrug-resistant Shiga toxin-producingEscherichia coliO157:H7

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2423 ◽  
Author(s):  
Luis Amarillas ◽  
Cristóbal Chaidez ◽  
Arturo González-Robles ◽  
Yadira Lugo-Melchor ◽  
Josefina León-Félix
Keyword(s):  
Host Range ◽  
Shiga Toxin ◽  
Pathogenic Bacteria ◽  
Genetic Material ◽  
Multidrug Resistant ◽  
Broad Host Range ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Tract Infections

BackgroundShiga toxin-producingEscherichia coli(STEC) is one of the most common and widely distributed foodborne pathogens that has been frequently implicated in gastrointestinal and urinary tract infections. Moreover, high rates of multiple antibiotic-resistantE. colistrains have been reported worldwide. Due to the emergence of antibiotic-resistant strains, bacteriophages are considered an attractive alternative to biocontrol pathogenic bacteria. Characterization is a preliminary step towards designing a phage for biocontrol.MethodsIn this study, we describe the characterization of a bacteriophage designated phiC119, which can infect and lyse several multidrug-resistant STEC strains and someSalmonellastrains. The phage genome was screened to detect thestx-genes using PCR, morphological analysis, host range was determined, and genome sequencing were carried out, as well as an analysis of the cohesive ends and identification of the type of genetic material through enzymatic digestion of the genome.ResultsAnalysis of the bacteriophage particles by transmission electron microscopy showed that it had an icosahedral head and a long tail, characteristic of the familySiphoviridae. The phage exhibits broad host range against multidrug-resistant and highly virulentE. coliisolates. One-step growth experiments revealed that the phiC119 phage presented a large burst size (210 PFU/cell) and a latent period of 20 min. Based on genomic analysis, the phage contains a linear double-stranded DNA genome with a size of 47,319 bp. The phage encodes 75 putative proteins, but lysogeny and virulence genes were not found in the phiC119 genome.ConclusionThese results suggest that phage phiC119 may be a good biological control agent. However, further studies are required to ensure its control of STEC and to confirm the safety of phage use.

scholarly journals Structural and functional characterization of CMP-N-acetylneuraminate synthetase fromVibrio cholerae

2019 ◽  
Vol 75 (6) ◽  
pp. 564-577
Author(s):  
Sucharita Bose ◽  
Debayan Purkait ◽  
Deepthi Joseph ◽  
Vinod Nayak ◽  
Ramaswamy Subramanian
Keyword(s):  
Sialic Acid ◽  
Vibrio Cholerae ◽  
Active Site ◽  
Drug Targets ◽  
Pathogenic Bacteria ◽  
Pasteurella Multocida ◽  
Bacterial Species ◽  
Functional Characterization ◽  
Gut Colonization

Several pathogenic bacteria utilize sialic acid, including host-derivedN-acetylneuraminic acid (Neu5Ac), in at least two ways: they use it as a nutrient source and as a host-evasion strategy by coating themselves with Neu5Ac. Given the significant role of sialic acid in pathogenesis and host-gut colonization by various pathogenic bacteria, includingNeisseria meningitidis,Haemophilus influenzae,Pasteurella multocidaandVibrio cholerae, several enzymes of the sialic acid catabolic, biosynthetic and incorporation pathways are considered to be potential drug targets. In this work, findings on the structural and functional characterization of CMP-N-acetylneuraminate synthetase (CMAS), a key enzyme in the incorporation pathway, fromVibrio choleraeare reported. CMAS catalyzes the synthesis of CMP-sialic acid by utilizing CTP and sialic acid. Crystal structures of the apo and the CDP-bound forms of the enzyme were determined, which allowed the identification of the metal cofactor Mg2+in the active site interacting with CDP and the invariant Asp215 residue. While open and closed structural forms of the enzyme from eukaryotic and other bacterial species have already been characterized, a partially closed structure ofV. choleraeCMAS (VcCMAS) observed upon CDP binding, representing an intermediate state, is reported here. The kinetic data suggest that VcCMAS is capable of activating the two most common sialic acid derivatives, Neu5Ac and Neu5Gc. Amino-acid sequence and structural comparison of the active site of VcCMAS with those of eukaryotic and other bacterial counterparts reveal a diverse hydrophobic pocket that interacts with the C5 substituents of sialic acid. Analyses of the thermodynamic signatures obtained from the binding of the nucleotide (CTP) and the product (CMP-sialic acid) to VcCMAS provide fundamental information on the energetics of the binding process.

scholarly journals THE IDENTIFICATION, PRODUCTION AND CHARACTERIZATION OF NATTOKINASE, BACTERIOCIN FROM BACTERIAL SPECIES

2019 ◽  
Vol 2 (4) ◽  
pp. 91
Author(s):  
Lal Krishna
Keyword(s):  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Blood Clot ◽  
Bacterial Species ◽  
Antagonistic Activity ◽  
Bacterial Strains ◽  
Wide Range

The study was aimed at identification, production and characterization of nattokinase, bacteriocin from bacterial species. Nattokinase and bacteriocins finds a wide range of applications in Pharmaceutical industry, health care and medicine. Nattokinase is a highly active fibrinolytic enzyme secreted by Bacillus subtilis and bacteriocins are proteinaceous toxins produced by Lactobacillus to inhibit the growth of closely related bacterial strains. Bacillus subtilis and Lactobacillus isolates shown positive results to microscopic, biochemical analysis.  The nattokinase and bacteriocins were produced by optimizing the media. The enzymes were purified by ammonium sulfate precipitation and HPLC. The enzyme activity for nattokinase was found at 7 mg/ml, pH 8.0 and temperature 48 ºC and the enzyme activity for bacteriocin was found at 3.9 mg/ml, pH 6.5 and temperature 30 °C. Bacteriocins from Lactobacillus showed good antagonistic activity against pathogenic bacteria. Nattokinase from Bacillus subtilis played a significant role in thrombolytic and anti-coagulation at in vitro. The results indicated that the pure enzyme has a potential in dissolving blood clot.

scholarly journals Towards Understanding the Molecular Basis of Nitric Oxide-Regulated Group Behaviors in Pathogenic Bacteria

2018 ◽  
Vol 11 (3) ◽  
pp. 205-215 ◽  
Author(s):  
Dominique E. Williams ◽  
Elizabeth M. Boon
Keyword(s):  
Nitric Oxide ◽  
Legionella Pneumophila ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Planktonic Cell ◽  
Antibiotic Resistant ◽  
Abiotic Surfaces ◽  
Biofilm Dispersal ◽  
Identification And Characterization

Pathogenic bacteria have many strategies for causing disease in humans. One such strategy is the ability to live both as single-celled motile organisms or as part of a community of bacteria called a biofilm. Biofilms are frequently adhered to biotic or abiotic surfaces and are extremely antibiotic resistant. Upon biofilm dispersal, bacteria become more antibiotic susceptible but are also able to readily infect another host. Various studies have shown that low, nontoxic levels of nitric oxide (NO) may induce biofilm dispersal in many bacterial species. While the molecular details of this phenotype remain largely unknown, in several species, NO has been implicated in biofilm-to-planktonic cell transitions via ligation to 1 of 2 characterized NO sensors, NosP or H-NOX. Based on the data available to date, it appears that NO binding to H-NOX or NosP triggers a downstream response based on changes in cellular cyclic di-GMP concentrations and/or the modulation of quorum sensing. In order to develop applications for control of biofilm infections, the identification and characterization of biofilm dispersal mechanisms is vital. This review focuses on the efforts made to understand NO-mediated control of H-NOX and NosP pathways in the 3 pathogenic bacteria Legionella pneumophila, Vibrio cholerae, and Pseudomonas aeruginosa.

Physicochemical Characterization of Bioactive Compounds in Nanocarriers

2020 ◽  
Vol 26 (33) ◽  
pp. 4163-4173
Author(s):  
Rafaella M. Barros ◽  
Maísa S. de Oliveira ◽  
Kammila M. N. Costa ◽  
Mariana R. Sato ◽  
Karen L. M. Santos ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Excretion Rate ◽  
Drug Carrier ◽  
Physicochemical Characterization ◽  
Pharmaceutical Product ◽  
Degree Of Crystallinity ◽  
Long Term Stability ◽  
New Methods

The encapsulation of bioactive compounds is an emerging technique for finding new medicines since it provides protection against ambient degradation factors before reaching the target site. Nanotechnology provides new methods for encapsulating bioactive compounds and for drug carrier development. Nanocarriers satisfactorily impact the absorption, distribution, metabolism, and excretion rate when compared to conventional carriers. The nanocarrier material needs to be compatible and bind to the drug and be bio-resorbable. In this context, the physicochemical characterization of encapsulated bioactive compounds is fundamental to guarantee the quality, reproducibility, and safety of the final pharmaceutical product. In this review, we present the physicochemical techniques most used today by researchers to characterize bioactive compounds in nanocarriers and the main information provided by each technique, such as morphology, size, degree of crystallinity, long-term stability, the efficacy of drug encapsulation, and the amount released as a function of time.

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

Distribution of Enteric Viruses and Microorganisms in Long-Term Sewage-Treated Soil

1983 ◽  
Vol 15 (5) ◽  
pp. 129-135 ◽  
Author(s):  
Z Filip ◽  
K Seidel ◽  
H Dizer
Keyword(s):  
Soil Bacteria ◽  
Pathogenic Bacteria ◽  
Sewage Treatment ◽  
Anaerobic Bacteria ◽  
Enteric Viruses ◽  
Sewage Irrigation ◽  
Groundwater Samples ◽  
West Berlin ◽  
Aerobic Soil

To determine whether long-term sewage treatment can take place without a pollution risk for soil and groundwater, samples from sewage irrigation fields in West Berlin which have been in use since about 1890 were analyzed for enteric viruses and microorganisms. Enteric viruses were detected in only seven samples from a total number of eighty seven taken from different soil depths. With only one exception, no viruses were found below 60 cm. No viruses were detected in groundwater samples. Long-term sewage irrigation did not result in significant changes in the colony courts of aerobic soil bacteria, but the counts of anaerobic bacteria and actinomycetes were slightly elevated and those of microscopic fungi slightly decreased. Potentially pathogenic bacteria were not detected in soil below 90 cm.

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