Association of nuisance filamentous algae Cladophora spp. with E. coli and Salmonella in public beach waters: impacts of UV protection on bacterial survival

2014 ◽  
Vol 16 (6) ◽  
pp. 1267-1274 ◽  
Author(s):  
Aubrey Beckinghausen ◽  
Alexia Martinez ◽  
David Blersch ◽  
Berat Z. Haznedaroglu
Keyword(s):  
Uv Protection ◽  
Filamentous Algae ◽  
Bacterial Survival ◽  
E Coli ◽  
Nuisance Algae

This study presents evidence of nuisance algae commonly found in public beach waters providing UV protection toE. coliandSalmonella.

scholarly journals The Influence of the Degradation of Tetracycline by Free Radicals from Riboflavin-5′-Phosphate Photolysis on Microbial Viability

2019 ◽  
Vol 7 (11) ◽  
pp. 500 ◽  
Author(s):  
Shiuh-Tsuen Huang ◽  
Shwu-Yuan Lee ◽  
Song-Hua Wang ◽  
Chun-Yi Wu ◽  
Jeu-Ming P. Yuann ◽  
...  
Keyword(s):  
Blue Light ◽  
Treatment Method ◽  
Light Irradiation ◽  
Flavin Mononucleotide ◽  
Molecular Formula ◽  
Bacterial Survival ◽  
Exact Mass ◽  
E Coli ◽  
Environmentally Sound ◽  
Antibiotic Degradation

Tetracycline (TC) is a broad-spectrum antibiotic compound. Wastewater with TC may have an adverse effect on ecosystems. Riboflavin-5′-phosphate (FMN or flavin mononucleotide) is a non-toxic product of the phosphorylation of vitamin B2 and is required for the proper functioning of the humans. FMN is sensitized to ultraviolet (UV) and blue light radiation, as evidenced by the generation of reactive oxygen species (ROS). This study inspects feasible applications of blue light on FMN so as to develop a valid way of degrading TC by FMN photolysis. We used the increased rate of bacterial survival as a practical indicator of antibiotic degradation. TC in the presence of FMN solution decomposed completely after 20 W/m2 of blue light irradiation (TCF treatment), and the degradation of TC (D-TCF) occurred after the photolytic process. After TCF treatment, colony-forming units (CFUs) of Escherichia coli (E. coli) were determined for the D-TCF solution. The CFU of E. coli preservation was 93.2% of the D-TCF solution (50 μg/mL of TC in the presence of 114 μg/mL of FMN solution treated with 20 W/m2 of blue light irradiation at 25 °C for 1 h) cultivation. The mass spectrum of D-TCF showed diagnostic ion signals at m/z 431.0 and 414.0 Da. The molecular formula of D-TCF was C21H22N2O8, and the exact mass was 430.44 g/mol. TC degradation by FMN photolysis can significantly decrease the antimicrobial ability of TC. The results expressed here regarding the influence of FMN photolysis on TC degradation offer an environmentally sound wastewater treatment method.

scholarly journals Occurrence and ecological determinants of the contamination of floodplain wetlands with Klebsiella pneumoniae and pathogenic or antibiotic-resistant Escherichia coli.

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
Charles P Henriot ◽  
Daniel Martak ◽  
Quentin Cuenot ◽  
Christophe Loup ◽  
Hélène Masclaux ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistant Bacteria ◽  
Bacterial Survival ◽  
Floodplain Wetlands ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Physico Chemical ◽  
Chemical Conditions ◽  
One Year ◽  
Three Rivers

ABSTRACT The survival and multiplication of human pathogenic and antibiotic-resistant bacteria in ecosystems is of increasing concern but has been little explored. Wetlands can be contaminated by water fluxes from rivers and may present environmental conditions leading to bacterial survival and multiplication. To test this hypothesis, we sampled 16 wetlands located along three rivers of the Jura Massif, France. The bacterial contamination of the wetland and river waters was measured monthly over a one-year cycle together with the water physico-chemical characteristics. We assessed the abundance of three pathogenic species: Escherichia coli,Klebsiella pneumoniaeand Pseudomonas aeruginosa. The concentrations of E. coli producing extended-spectrum β-lactamase (ESBL E. coli) or belonging to the phylogenetic group B2 (E. coli B2–more pathogenic) were also measured. We found that rivers carried total E. coli, ESBL E. coli, and K. pneumoniae to wetlands. ESBL E. coli poorly survived in wetlands, whereas total E. coli and K. pneumoniae possibly met favourable physico-chemical conditions for survival and multiplication in these habitats. K. pneumoniae peaked in summer in warm and shallow wetlands. Total E. coli and E. coli B2 potentially reached wetlands through sources other than rivers (hillslope groundwater or leaching from contaminated fields).

scholarly journals Guarea kunthiana Bark Extract Enhances the Antimicrobial Activities of Human and Bovine Neutrophils

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Natalja Jerjomiceva ◽  
Hisham Seri ◽  
Ragheda Yaseen ◽  
Nicole de Buhr ◽  
William N. Setzer ◽  
...  
Keyword(s):  
Cell Types ◽  
Antimicrobial Activities ◽  
Bark Extract ◽  
Bacterial Survival ◽  
First Line ◽  
E Coli ◽  
Microbial Infections ◽  
Survival Assay ◽  
Folk Remedies ◽  
Bovine Neutrophils

Guarea kunthiana is used in folk remedies for the treatment of several diseases including microbial infections. The mechanism behind this phenomenon still needs to be elucidated. Here, we investigated the effect of G. kunthiana bark extract on antimicrobial functions of human and bovine neutrophils as the first line of defense against infections. For this aim, neutrophils were isolated from either human or bovine blood and treated with G. kunthiana bark extract. The antimicrobial activity of the neutrophils against Staphylococcus (S.) aureus and Escherichia (E.) coli was tested in a bacterial survival assay and a fluorescence-based phagocytosis assay. Furthermore, the formation of neutrophil extracellular traps (NETs) was visualized by immunofluorescence microscopy. We show that neutrophils treated with G. kunthiana extract distinctly increased phagocytosis of S. aureus or E. coli. Interestingly, we demonstrate that G. kunthiana bark extract induces the formation of NETs in both cell types. This effect was abolished when treating the cells with diphenyleniodonium chloride (DPI) pointing to a direct implication of the NADPH oxidase-dependent formation of reactive oxygen species in this process. In summary, our data strongly suggest that G. kunthiana bark extract boosts the antimicrobial activities of neutrophils as the first line of defense against invading pathogens.

scholarly journals mcr-1 Gene Expression Modulates the Inflammatory Response of Human Macrophages to Escherichia coli

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Giorgio Mattiuz ◽  
Sabrina Nicolò ◽  
Alberto Antonelli ◽  
Tommaso Giani ◽  
Ilaria Baccani ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lipid A ◽  
Nuclear Translocation ◽  
Interleukin 12 ◽  
Bacterial Survival ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Human Macrophages ◽  
E Coli ◽  
The Impact

ABSTRACT MCR-1 is a plasmid-encoded phosphoethanolamine transferase able to modify the lipid A structure. It confers resistance to colistin and was isolated from human, animal, and environmental strains of Enterobacteriaceae, raising serious global health concerns. In this paper, we used recombinant mcr-1-expressing Escherichia coli to study the impact of MCR-1 products on E. coli-induced activation of inflammatory pathways in activated THP-1 cells, which was used as a model of human macrophages. We found that infection with recombinant mcr-1-expressing E. coli significantly modulated p38-MAPK and Jun N-terminal protein kinase (JNK) activation and pNF-κB nuclear translocation as well as the expression of genes for the relevant proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-12 (IL-12), and IL-1β compared with mcr-1-negative strains. Caspase-1 activity and IL-1β secretion were significantly less activated by mcr-1-positive E. coli strains than the mcr-1-negative parental strain. Similar results were obtained with clinical isolates of mcr-1-positive E. coli, suggesting that, in addition to colistin resistance, the expression of mcr-1 allows the escape of early host innate defenses and may promote bacterial survival.

Survival of Pathogenic Bacteria in Pesticide Solutions and on Treated Tomato Plants

2005 ◽  
Vol 68 (2) ◽  
pp. 296-304 ◽  
Author(s):  
TIFFANY T. Y. GUAN ◽  
GREGORY BLANK ◽  
RICHARD A. HOLLEY
Keyword(s):  
Membrane Filtration ◽  
Salmonella Enteritidis ◽  
Pathogenic Bacteria ◽  
Incubation Temperature ◽  
Bacterial Survival ◽  
Salmonella Spp ◽  
Tomato Plants ◽  
Sterile Saline ◽  
E Coli ◽  
Pesticide Formulations

The ability of Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Shigella to survive or grow in pesticide solutions (Ambush 240EC, Benlate T-N-G, Bravo 500, Botran 75WP, Captan 80WDG, Parasol, and Vendex 50W) used by the horticultural industry was examined. In the laboratory, individual cultures were inoculated at 4 log CFU/ml in pesticides diluted with sterile saline to the lowest recommended spray concentrations. During 21°C incubation for ≤96 h, bacterial survivors in the samples and a control consisting of saline were enumerated either by agar surface plating or hydrophobic grid membrane filtration. Most formulations tested were somewhat inhibitory to the pathogenic bacteria. All inoculated bacteria survived or grew in Bravo 500. Among bacteria tested, Salmonella spp. were best able to survive and Listeria spp. were least able to survive in pesticide solutions. When the incubation temperature or pesticide concentration was increased, survival of Salmonella varied depending on the type of formulation. In the field, when a bacterial cocktail containing E. coli O157:H7 and Salmonella Enteritidis was added to Bravo 500 at 6 log CFU/ml, both organisms were recovered from leaves and fruit skins of sprayed tomato plants after the recommended 1 day-to-harvest interval. E. coli and Salmonella survived longer on tomato leaves when sprayed in saline (at least 26 and 56 days, respectively) than when sprayed in Bravo 500 (>45 h and <15 days, respectively). While Salmonella serovars Typhimurium and Heidelberg grew in the fungicide Bravo, and Enteritidis grew in the insecticide Vendex within 96 h at 21°C in the laboratory, pathogen growth in other pesticide formulations did not occur. Higher temperature (≤30°C) or doubling pesticide concentrations had either no or a negative effect on Salmonella Heidelberg survival. Use of unexpired pesticide formulations may have contributed to the reduced bacterial survival and growth found in the laboratory and during the field trials with Bravo.

Survival of Escherichia coli in agricultural soil and presence in tile drainage and shallow groundwater

2010 ◽  
Vol 90 (3) ◽  
pp. 495-505 ◽  
Author(s):  
A C VanderZaag ◽  
K J Campbell ◽  
R C Jamieson ◽  
A C Sinclair ◽  
L G Hynes
Keyword(s):  
Escherichia Coli ◽  
Fecal Contamination ◽  
Shallow Groundwater ◽  
Drainage Water ◽  
Tile Drainage ◽  
Subsurface Water ◽  
Bacterial Survival ◽  
Manure Application ◽  
Monitoring Wells ◽  
E Coli

Animal agriculture and the use of manure as a soil amendment can lead to enteric pathogens entering water used for drinking, irrigation, and recreation. The presence of Escherichia coli in water is commonly used as an indicator of recent fecal contamination; however, a few recent studies suggest some E. coli populations are able to survive for extended time periods in agricultural soils. This important finding needs to be further assessed with field-scale studies. To this end, we conducted a 1-yr study within a 9.6-ha field that had received fertilizer and semi-solid dairy cattle manure annually for the past decade. Escherichia coli concentrations were monitored throughout the year (before and after manure application) in the effluent from tile drains (at approximately 80 cm depth) and in 5- to 8-m-deep groundwater wells. Escherichia coli was detected in both groundwater and tile drain effluent at concentrations exceeding irrigation and recreational water-quality guidelines. Within two of the monitoring wells, concentrations of E. coli, and frequency of detections, were greatest several months after the manure application. In two monitoring wells and one tile drain the frequency of E. coli detections was higher before manure was applied than after. This suggests the presence and abundance of E. coli was not strongly related to the timing of manure application. A laboratory study using naladixic acid resistant E. coli showed the bacteria could survive at least two times longer in soil samples collected from the study field than in soil from the adjacent riparian area, which had not received manure applications. Together, field and lab results suggest that a consistent source of E. coli exists within the field, which may include “naturalized” strains of E. coli. Further studies are required to determine the specific source of E. coli detected in tile drainage water and shallow groundwater. If the E. coli recovered in subsurface water is primarily mobilized from naturalized populations residing within the soil profile, this indicator organism would have little value as an indicator of recent fecal contamination. Key words: Bacterial survival, naturalized Escherichia coli, groundwater, tile drainage

scholarly journals Nickel Promotes Biofilm Formation by Escherichia coli K-12 Strains That Produce Curli

2009 ◽  
Vol 75 (6) ◽  
pp. 1723-1733 ◽  
Author(s):  
Claire Perrin ◽  
Romain Briandet ◽  
Gregory Jubelin ◽  
Philippe Lejeune ◽  
Marie-Andrée Mandrand-Berthelot ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Molecular Mechanisms ◽  
Selective Advantage ◽  
Bacterial Survival ◽  
Toxic Compounds ◽  
E Coli ◽  
Transcriptional Effect ◽  
K 12 ◽  
Encoding Genes

ABSTRACT The survival of bacteria exposed to toxic compounds is a multifactorial phenomenon, involving well-known molecular mechanisms of resistance but also less-well-understood mechanisms of tolerance that need to be clarified. In particular, the contribution of biofilm formation to survival in the presence of toxic compounds, such as nickel, was investigated in this study. We found that a subinhibitory concentration of nickel leads Escherichia coli bacteria to change their lifestyle, developing biofilm structures rather than growing as free-floating cells. Interestingly, whereas nickel and magnesium both alter the global cell surface charge, only nickel promotes biofilm formation in our system. Genetic evidence indicates that biofilm formation induced by nickel is mediated by the transcriptional induction of the adhesive curli-encoding genes. Biofilm formation induced by nickel does not rely on efflux mechanisms using the RcnA pump, as these require a higher concentration of nickel to be activated. Our results demonstrate that the nickel-induced biofilm formation in E. coli is an adaptational process, occurring through a transcriptional effect on genes coding for adherence structures. The biofilm lifestyle is obviously a selective advantage in the presence of nickel, but the means by which it improves bacterial survival needs to be investigated.

scholarly journals Involvement of the Escherichia coli O157:H7(pO157) ecf Operon and Lipid A Myristoyl Transferase Activity in Bacterial Survival in the Bovine Gastrointestinal Tract and Bacterial Persistence in Farm Water Troughs

2005 ◽  
Vol 73 (4) ◽  
pp. 2367-2378 ◽  
Author(s):  
Jang W. Yoon ◽  
Ji Youn Lim ◽  
Yong H. Park ◽  
Carolyn J. Hovde
Keyword(s):  
Escherichia Coli ◽  
Membrane Structure ◽  
Lipid A ◽  
Transferase Activity ◽  
Bacterial Membrane ◽  
Dna Curvature ◽  
Bacterial Survival ◽  
Genetic Redundancy ◽  
E Coli

ABSTRACT Escherichia coli O157:H7 is an important food-borne pathogen that causes hemorrhagic colitis and the hemolytic-uremic syndrome in humans. Recently, we reported that the pO157 ecf (E. coli attaching and effacing gene-positive conserved fragments) operon is thermoregulated by an intrinsically curved DNA and contains the genes for bacterial surface-associated proteins, including a second copy of lipid A myristoyl transferase, whose chromosomal copy is the lpxM gene product. E. coli O157:H7 survives and persists well in diverse environments from the human and bovine gastrointestinal tracts (GIT) to nutrient-dilute farm water troughs. Transcriptional regulation of the ecf operon by intrinsic DNA curvature and the genetic redundancy of lpxM that is associated with lipid A modification led us to hypothesize that the pO157 ecf operon and lpxM are associated with bacterial survival and persistence in various in vivo and ex vivo environments by optimizing bacterial membrane structure and/or integrity. To test this hypothesis, three isogenic ecf operon and/or lpxM deletion mutants of E. coli O157:H7 ATCC 43894 were constructed and analyzed in vitro and in vivo. The results showed that a double mutant carrying deletions in the ecf and lpxM genes had an altered lipid A structure and membrane fatty acid composition, did not survive passage through the bovine GIT, did not persist well in farm water troughs, had increased susceptibility to a broad spectrum of antibiotics and detergents, and had impaired motility. Electron microscopic analyses showed gross changes in bacterial membrane structure.

scholarly journals MurF Inhibitors with Antibacterial Activity: Effect on Muropeptide Levels

2009 ◽  
Vol 53 (8) ◽  
pp. 3240-3247 ◽  
Author(s):  
Ellen Z. Baum ◽  
Steven M. Crespo-Carbone ◽  
Barbara D. Foleno ◽  
Lee D. Simon ◽  
Jerome Guillemont ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pharmacophore Model ◽  
Polymyxin B ◽  
Bacterial Survival ◽  
Wild Type ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Activity Effect ◽  
Modest Activity

ABSTRACT MurF catalyzes the last cytoplasmic step of bacterial cell wall synthesis and is essential for bacterial survival. Our previous studies used a pharmacophore model of a MurF inhibitor to identify additional inhibitors with improved properties. We now present the characterization of two such inhibitors, the diarylquinolines DQ1 and DQ2. DQ1 inhibited Escherichia coli MurF (50% inhibitory concentration, 24 μM) and had modest activity (MICs, 8 to 16 μg/ml) against lipopolysaccharide (LPS)-defective E. coli and wild-type E. coli rendered permeable with polymyxin B nonapeptide. DQ2 additionally displayed activity against gram-positive bacteria (MICs, 8 to 16 μg/ml), including methicillin (meticillin)-susceptible and -resistant Staphylococcus aureus isolates and vancomycin-susceptible and -resistant Enterococcus faecalis and Enterococcus faecium isolates. Treatment of LPS-defective E. coli cells with ≥2× MIC of DQ1 resulted in a 75-fold-greater accumulation of the MurF substrate compared to the control, a 70% decline in the amount of the MurF product, and eventual cell lysis, consistent with the inhibition of MurF within bacteria. DQ2 treatment of S. aureus resulted in similar effects on the MurF substrate and product quantities. At lower levels of DQ1 (≤1× MIC), the level of accumulation of the substrate was less pronounced (15-fold greater compared to the amount for the control). However, a 50% increase in the amount of the MurF product compared to the control was reproducibly observed, consistent with the possible upregulation of muropeptide biosynthesis upon partial inhibition of this pathway. The overexpression of cloned MurF appeared to partly alleviate the DQ1-mediated inhibition of muropeptide synthesis. The identification of MurF inhibitors such as DQ1 and DQ2 that disrupt cell wall biosynthesis suggests that MurF remains a viable target for an antibacterial agent.

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