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.

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 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 Identification and characterization of two amylase producing bacteria Cellulosimicrobium sp. and Demequina sp. isolated from marine organisms

2015 ◽  
Vol 20 ◽  
pp. 8 ◽  
Author(s):  
Laila S.H. Al-Naamani ◽  
Sergey Dobretsov ◽  
Jamal Al-Sabahi ◽  
Bassam Soussi
Keyword(s):  
Cell Growth ◽  
Bacterial Species ◽  
Marine Organisms ◽  
Ulva Rigida ◽  
Wide Range ◽  
Amylase Production ◽  
Maximum Cell ◽  
Commercial Applications ◽  
Identification And Characterization

Marine sources have been known to yield novel compounds with a wide range of bioactivity with various commercial applications. In this study, the abilities of bacteria isolated from eight marine organisms to produce α-amylase were examined. All eight organisms were found to harbor amylase producing bacteria. Two bacterial species isolated from the green alga Ulva rigida and the sponge Mycale sp. were further identified and their α-amylases were purified and characterized. The bacterial species isolated from U. rigida and Mycale sp. were identified by DNA sequencing as Cellulosimicrobium sp. and Demequina sp., respectively. Cellulosimicrobium sp. obtained maximum cell growth and amylase production at 29.C and in the presence of lactose as a carbon source. Optimal cell growth and amylase production by Demequina sp. was observed at 35.C. While lactose enhanced cell growth of Demequina sp., maximum amylase production was found when fructose and glycerol were the available sources of carbon. Both strains grew better in the presence of tryptone, whilst peptone stimulated amylase production. Maximal cell growth and amylase production by both of the strains was found at a medium salinity of 3% NaCl. 

scholarly journals Characterization of Antibioticproducing Bacterium Isolated From Anthill Sediment With Activity Against ESKAPE Pathogens

Fine Focus ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. 189-201
Author(s):  
Cody A. Postich ◽  
Kevin B. Kiser
Keyword(s):  
Pathogenic Bacteria ◽  
Acinetobacter Calcoaceticus ◽  
Organic Substrates ◽  
Antibiotic Resistant ◽  
Local Environments ◽  
Small Molecule Analysis ◽  
Eskape Pathogens ◽  
The Impact ◽  
Ethyl Acetate Extracts

Healthcare institutions have seen an increase in infections caused by antibiotic-resistant ESKAPE pathogens. Current antibiotics have become less potent against pathogenic bacteria due to their overuse and misuse. In recent years, scientists have revisited local environments in search of novel antibioticproducing microbes to address the increasing threat of resistance. One species of bacteria was isolated from anthill sediment in coastal North Carolina. This environment was selected for its abiotic properties, including organic substrates, moisture saturation and aeration. Anthill isolate A2, inhibited various Grampositive and negative ESKAPE pathogens or their surrogates, including Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter calcoaceticus, in crossstreak tests. 16S rRNA sequencing identified isolate A2 as Pseudomonas koreensis. Mass spectrometry and small-molecule analysis performed on ethyl-acetate extracts of culture supernatant were used to evaluate bioactivity and identify the probable structure of one potential antimicrobial compound, monolauryl maleate. Discovery of novel antimicrobial compounds to replace overused antibiotics may help reduce the impact of antibiotic-resistant pathogens.

scholarly journals Development of a DNA microarray assay for rapid detection of fifteen bacterial pathogens in pneumonia

2020 ◽  
Author(s):  
Xiuqing Ma ◽  
Yanqin Li ◽  
Yuan Liang ◽  
Yang Liu ◽  
Ling Yu ◽  
...  
Keyword(s):  
Dna Microarray ◽  
Legionella Pneumophila ◽  
Burkholderia Cepacia ◽  
Pathogenic Bacteria ◽  
Chlamydia Pneumoniae ◽  
Bacterial Pathogens ◽  
Bacterial Species ◽  
Simultaneous Detection ◽  
Clinical Isolates ◽  
Microarray Assay

Abstract Background: The rapid identification of pathogenic bacteria is important for determining an appropriate antimicrobial therapy for pneumonia, but traditional bacterial culture is time-consuming and labourious. The aim of this study was to develop and evaluate a DNA microarray assay for the simultaneous detection of fifteen bacterial species directly from respiratory tract specimens in patients with pneumonia. These species included Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Mycoplasma pneumoniae, Enterococcus faecalis, Enterococcus faecium, Enterobacter cloacae, Stenotrophomonas maltophilia, Burkholderia cepacia, Legionella pneumophila and Chlamydia pneumoniae. The 16S rDNA genes and other specific genes of each pathogen were chosen as the amplification targets, amplified via multiplex polymerase chain reaction (PCR), and hybridized to oligonucleotide probes in a microarray.Results: The DNA microarray detection limit was 103 copies/μL. Nineteen standard strains and 119 clinical isolates were correctly detected with our microarray, and 3 nontarget species from 4 clinical isolates were not detected. Additionally, bacterial pathogens were accurately identified when two or three bacterial targets were mixed together. Furthermore, the results for 99.4% (156/157) of clinical specimens were the same as those from a conventional assay.Conclusions: We developed a DNA microarray that could simultaneously detect various bacterial pathogens in pneumonia. The method described here has the potential to provide considerable labour and time savings due to its ability to screen for 15 bacterial pathogens simultaneously.

Phage-mediated dissemination of virulence factors in pathogenic bacteria facilitated by antibiotic growth promoters in animals: a perspective

2017 ◽  
Vol 18 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Migma Dorji Tamang ◽  
Hoon Sunwoo ◽  
Byeonghwa Jeon
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Growth Promotion ◽  
Bacterial Species ◽  
Agricultural Practice ◽  
Growth Promoters ◽  
Antibiotic Resistant ◽  
The World ◽  
Antibiotic Growth Promoters

AbstractAddition of sub-therapeutic antibiotics to the feed of food-producing animals for growth promotion and disease prevention has become a common agricultural practice in many countries. The emergence of antibiotic-resistant pathogens is a looming concern associated with the use of antibiotic growth promoters (AGPs) around the world. In addition, some studies have shown that AGPs may not only affect antibiotic resistance but may also stimulate the dissemination of virulence factors via bacteriophages. Although only a few studies are currently available in the literature regarding this topic, in this article we endeavor to provide a perspective about how AGPs would impact the transmission of virulence factors by horizontal gene transfer via phages in a few pathogenic bacterial species significant to livestock production.

scholarly journals The Prevalence and Characterization of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Bacteria from Hospital Sewage, Treated Effluents and Receiving Rivers

2020 ◽  
Vol 17 (4) ◽  
pp. 1183 ◽  
Author(s):  
Luhua Zhang ◽  
Xinyue Ma ◽  
Li Luo ◽  
Nan Hu ◽  
Jiayao Duan ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Carbapenem Resistant ◽  
High Prevalence ◽  
Treated Effluents ◽  
Hospital Sewage

Hospital sewage plays a key role in the dissemination of antibiotic-resistant genes (ARGs) by serving as an environmental antimicrobial resistance reservoir. In this study, we aimed to characterize the cephalosporin- and carbapenem-resistant isolates from hospital sewage and receiving rivers. The results showed that ESBL (blaCTX-M) and carbapenemase genes (blaNDM and blaKPC) were widely detected in a number of different bacterial species. These resistance genes were mainly harbored in Enterobacteriaceae, followed by Acinetobacter and Aeromonas isolates. More attention should be given to these bacteria as important vectors of ARGs in the environment. Furthermore, we showed that the multidrug resistance phenotype was highly prevalent, which was found in 85.5% Enterobacteriaceae and 75% Acinetobacter strains. Notably, the presence of carbapenemase genes in isolates from treated effluents and receiving rivers indicates that the discharges of wastewater treatment plants could be an important source for high-risk resistance genes propagation to the environment. In conclusion, this study shows a high prevalence of ESBL- and carbapenemase-producing bacteria in hospital sewage and receiving rivers in China. These findings have serious implications for human health, and also suggest the need for more efforts to control the dissemination of resistant bacteria from hospital sewage into the environment.

scholarly journals Anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones as a New Class of Antistaphylococcal Agents: Synthesis and Biological Evaluation

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4581
Author(s):  
Viktor Zvarych ◽  
Maryna Stasevych ◽  
Volodymyr Novikov ◽  
Eduard Rusanov ◽  
Mykhailo Vovk ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Modern Medicine ◽  
Biological Evaluation ◽  
Dilution Method ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Mrsa Strains ◽  
Time Kill

The development and spread of resistance of human pathogenic bacteria to the action of commonly used antibacterial drugs is one of the key problems in modern medicine. One of the especially dangerous and easily developing antibiotic resistant bacterial species is Staphylococcus aureus. Anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones 22–38 have been developed as novel effective antistaphylococcal agents. These compounds have been obtained by sequential conversion of 1-amino-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid (1) and 1-amino-4-bromo-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid (2) into the corresponding amides 5–21, followed by subsequent endo-cyclization under the influence of sodium nitrite in acetic acid. Evaluation of the antimicrobial activity of the synthesized compounds against selected species of Gram-positive and Gram-negative bacteria as well as pathogenic yeasts of the Candida genus has been carried out by the serial dilution method. It has been established that anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones exhibit selective antibacterial activity against Gram-positive bacteria. Eight, six and seven, out of seventeen compounds tested, effectively inhibited the growth of S. aureus ATCC 25923, S. aureus ATCC 29213 and S. epidermidis ATCC12228, respectively, at a concentration equal to 1 µg/mL or lower. The high antistaphylococcal potential of the most active compounds has been also confirmed against clinical isolates of S. aureus, including the MRSA strains. However, bacteria of the Staphylococcus genus have demonstrated apparent resistance to the novel compounds when grown as a biofilm. None of the four selected compounds 3234 and 36 at a concentration of 64 µg/mL (128 or 256 × MIC—against planktonic cells) has caused any decrease in the metabolic activity of the staphylococcal cells forming the biofilm. The kinetic time–kill assay revealed some important differences in the activity of these substances. Compound 33 is bacteriostatic, while the other three demonstrate bactericidal activity.

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