scholarly journals Toxicity of herbicides on Escherichia coli growth

2012 ◽  
Vol 72 (1) ◽  
pp. 141-146 ◽  
Author(s):  
RG Botelho ◽  
CM Froes ◽  
JB Santos
Keyword(s):  
Escherichia Coli ◽  
Weed Control ◽  
The Other ◽  
Aquatic Environments ◽  
Other Hand ◽  
Aquatic Microorganisms ◽  
Increase Productivity ◽  
Huge Variety ◽  
Coli Growth

Agriculture uses a huge variety and quantity of chemicals. If, on one hand, the goal is to increase productivity, on the other hand these products contaminate aquatic environments. Among these products, herbicides deserve greater attention in relation to contamination of aquatic environments due to their extensive use to weed control. This study was carried out because the effects of these molecules on aquatic microorganisms such as Escherichia coli, is still unclear. Using microdilution plate assays, Escherichia coli were exposed to various commercial formulations of herbicides widely used in Brazil. The herbicide paraquat was the only one able to prevent the growth of Escherichia coli and is characterized as bacteriostatic.

EFFECT OF SEVERAL HERBICIDES ON GERMINATION, SURVIVAL, AND EARLY GROWTH OF CARAGANA AND ON WEEDS

1965 ◽  
Vol 45 (5) ◽  
pp. 477-486
Author(s):  
R. Grover
Keyword(s):  
Weed Control ◽  
Early Growth ◽  
The Other ◽  
Weed Species ◽  
Other Hand ◽  
Weed Seeds ◽  
Caragana Arborescens ◽  
Hand Weeding ◽  
Greenhouse Tests

Several pre-emergence herbicides were tested, both in the greenhouse and in the field, for tolerance to germinating and 1-year-old seedlings of caragana (Caragana arborescens Lam.) and for effectiveness in controlling weeds.Dinoseb (4,6-dinitro-o-sec-butylphenol) and its alkanolamine salt at 8 lb/ac, trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) at 4 to 6 lb/ac, DCPA (dimethyl 2,3,5,6-tetrachloroterephthalate) at 15 lb/ac, swep (methyl 3,4-dichlorocarbanilate) at 6 to 9 lb/ac, and Tenoran (N-4-(p-chlorophenoxy)-phenyl-1,1-dimethylurea) at 6 lb/ac gave satisfactory weed control with no injury to germinating caragana seedlings. Liquid formulations of dinoseb or dinoseb-amine were more effective than the granular dinoseb formulation at rates of 8 lb/ac or less. Mixtures of dinoseb, trifluralin, and DCPA were also effective and these may be used where a wider weed species spectrum is encountered.Trifluralin at 6 lb/ac and mixtures of granular dinoseb at 8 to 12 lb/ac with DCPA at 10 lb/ac also provided satisfactory weed control with no injury to 1-year-old caragana seedlings.In the greenhouse tests, pre-emergence applications of trifluralin, diphenamid (N,N-dimethyl-2,2-diphenylacetamide), swep, DCPA, and DMPA (Q-(2,4-dichlorophenyl) O-methyl isopropylphosphoramidothioate) did not retard the germination of weed seeds, but the young weed seedlings were either killed or retarded in growth as the experiments progressed. On the other hand, linuron (3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea), dichlobenil (2,6-dichlorobenzonitrile), and dinoseb affected the emergence of weed seedlings. The weeds surviving the dinoseb treatment grew well. Hand-weeding stimulated the germination of more weed seeds.

scholarly journals Effect of inhibition of DNA synthesis on mating inEscherichia coliK12

1965 ◽  
Vol 6 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Susan Hollom ◽  
R. H. Pritchard
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Amino Acid Starvation ◽  
The Other ◽  
Thymine Starvation ◽  
Other Hand ◽  
Inhibition Of Dna Synthesis ◽  
Polynucleotide Chain

From studies involving inhibition of DNA synthesis in Hfr strains ofEscherichia coliK12, either by thymine starvation (Pritchard, 1963) or amino-acid starvation (Suit, Matney, Doudney & Billen, 1964), during mating withF−strains, it has been concluded that transfer of DNA from males to females can occur in the absence of DNA synthesis. This conclusion is at variance with the hypothesis (Jacob, Brenner & Cuzin, 1963) that the energy required for transfer is derived from the process of DNA replication. On the other hand, a second prediction from this hypothesis, that one polynucleotide chain of the DNA transferred during mating will have been synthesized during transfer, is strongly supported by recent experiments (Ptashne, 1965; Blinkova, Bresler & Lanzov, 1965; Gross & Caro, 1965).

Gut Flora in Autistic Children as Biomarker for Autism in Thi-Qar Province/Iraq

2020 ◽  
pp. 73-79
Keyword(s):  
Escherichia Coli ◽  
Enterococcus Faecalis ◽  
The Other ◽  
Bacterial Isolates ◽  
Autistic Children ◽  
Gram Positive ◽  
Gram Negative ◽  
Other Hand ◽  
Significant Difference ◽  
Gram Positive Cocci

This is the first study that investigated the microbial factor as biomarker in autistic children and discuss roles of this factor in the pathogenesis of autism. The participants in current study were 145 persons, only 50 sample of stool could collected (35 autistic children and 15 healthy children). Autistic children were attended to autism unit at Disabled Hospital in Thi-Qar province, Iraq during the period from January to November 2016. The results showed males (81%) more than female (19%) with ratio 4:1 and also results explain the age group of 3-5 years recorded the highest percentage (41.05%). Distribution of autistic children according to sibling showed six were brotherly with occurrence rate 6.3%. Stool samples were subjected to examination and culture. The total aerobic count of isolated bacteria was 140 isolates. Gram-negative isolates were identified by API Enterobacteriaceae system. The results were Escherichia coli, Enterobacter cloacae, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus mirabilis with percentage 38.5%, 19.23%, 11.53%,7.69%, and 3.84% respectively. On the other hand, gram positive cocci isolates included Enterococcus faecalis, Staphylococcus aureus and Staph. epidermidis with percentage 11.53%, 4.80% and 2.88% respectively. A significant difference (P≤0.05) was recorded between bacterial isolates. Quantity and quality of isolated bacteria (colony/g *104) were done. E.coli isolates were the highest count with 261*104 colony/g while, Staphylococci epidermidis were recorded the worse colony count with 30*104 colony/g. The quality results showed Escherichia coli the most common gram negative bacterial isolates (38.46%). On the other hand, the highest gram positive cocci isolates were included Enterococcus faecalis (11.53%), with significant difference (P≤0.05) between bacterial isolates. The ability of bacterial isolates to produce histidine decarboxylase was examined on Niven medium. The positive result include colonies with purple halo around them. Only 10 isolates (25%) from all isolates were produce histidine belong to E.coli. On other hand, result of parasite examination explain no parasite in all samples. From this study can conclusion the altered gut microflora may play an essential role in the pathogenesis of autism. Despite the accurate evidence, this etiological heterogeneity is still not recognized by autism researchers, and most studies fail to take it into account.

Bactericidal efficacy of electrospun pure and Fe-doped titania nanofibers

2010 ◽  
Vol 25 (9) ◽  
pp. 1761-1770 ◽  
Author(s):  
Abdul-Majeed Azad ◽  
Ryan Hershey ◽  
Saqib Ali ◽  
Vijay Goel
Keyword(s):  
Escherichia Coli ◽  
Wound Healing ◽  
Titanium Dioxide ◽  
Bacterial Colonization ◽  
The Other ◽  
Bactericidal Efficacy ◽  
Other Hand ◽  
Iron Doped ◽  
Doped Titanium Dioxide ◽  
Doped Titania

This paper reports the development of nonwoven nanofibers of pure and iron-doped titanium dioxide (TiO2) and evaluation of their antimicrobial attributes for using them as disinfectant gauze for wound healing upon brief activation by ultraviolet/infrared (UV/IR) illumination. It was found that the fibers exhibited superior bactericidal affinity when exposed briefly (3–12 s) to either multiphoton laser or infrared radiations. On the other hand, exposure to a UV beam for up to 20 min was not effective in mitigating the bacterial colonization of the Escherichia coli.

Bacteria and Virus Removal from Secondary Effluent in Sand and Red Mud Columns

1991 ◽  
Vol 23 (1-3) ◽  
pp. 261-270 ◽  
Author(s):  
Goen E. Ho ◽  
Robyn A. Gibbs ◽  
Kuruvilla Mathew
Keyword(s):  
Escherichia Coli ◽  
Red Mud ◽  
Breakthrough Curves ◽  
The Other ◽  
Column Experiments ◽  
Secondary Effluent ◽  
Soil Columns ◽  
Virus Removal ◽  
E Coli ◽  
Other Hand

Column experiments were conducted to determine the improvement in the removal of Escherichia coli, Salmonella adelaide and poliovirus-1 through sands by amendment with bauxite refining residue. The residue (red mud) was neutralized using 5 % gypsum and incorporated to form 30% of the amended sands. In 65 cm long soil columns the removal of the three organisms in the amended sand columns was excellent with over seven orders of magnitude reduction in concentration. Removal in unamended sands was poor. From breakthrough curves in unamended sand columns filtration, die-off and adsorption all appear to play a role in organism removal. The results also show that E. coli can be used as an indicator for contamination, though S.adelaide was less efficiently removed than E. coli. Poliovirus was on the other hand better removed than E. coli.

scholarly journals Evaluación de la mezcla de ametrina + clomazone en caña de azúcar.

2006 ◽  
Vol 12 (2) ◽  
pp. 161 ◽  
Author(s):  
Valentín A. Esqueda ◽  
Liviana Altamirano ◽  
Yanett Hernández ◽  
Alicia López
Keyword(s):  
Plant Height ◽  
Weed Control ◽  
The State ◽  
The Other ◽  
Sucrose Content ◽  
Plant Leaves ◽  
Sugarcane Varieties ◽  
Other Hand ◽  
Stalk Yield ◽  
Bleached Area

An experiment was established at Rancho Casablanca, located in the Municipality of Puente Nacional, in the State of Veracruz, Mexico, in order to evaluate the toxicity caused by the mixture of the herbicides ametryn + clomazone to the sugarcane varieties MEX-79-431, MEX- 69-290, MEX-68-P23 and CP-72-2086. Four weed control treatments were evaluated: 1. Ametryn + clomazone (1200 + 800 g/ha), 2. Ametryn + clomazone (1800 + 1200 g/ha), 3. Ametryn + 2,4-D (1225 + 650 g/ha) and 4. Weeded control. Herbicides were applied when sugarcane plants had from two to four leaves. The mixture of ametryn + clomazone caused leaf bleaching in all the sugarcane varieties. The bleached area varied from 36.3 to 47.5% with the highest dose of the mixture, and from 25 to 39.4%, with the lowest dose, and it practically disappeared about 45 days after application. On the other hand, the mixture of ametryn + 2,4-D did not cause any bleaching. Toxicity caused by the mixture of ametryn + clomazone did not affect the number of plant leaves, the number of stalks in 2 linear m, nor the plant height. Stalk yield and sucrose content were not affected either.

scholarly journals Genetic Plurality of OXA/NDM-Encoding Features Characterized From Enterobacterales Recovered From Czech Hospitals

2021 ◽  
Vol 12 ◽  
Author(s):  
Katerina Chudejova ◽  
Lucie Kraftova ◽  
Vittoria Mattioni Marchetti ◽  
Jaroslav Hrabak ◽  
Costas C. Papagiannitsis ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Risk ◽  
Klebsiella Pneumoniae ◽  
The Other ◽  
Travel History ◽  
Genetic Environment ◽  
E Coli ◽  
Resistance Determinants ◽  
Other Hand ◽  
Previous Hospitalization

The aim of this study was to characterize four Enterobacterales co-producing NDM- and OXA-48-like carbapenemases from Czech patients with travel history or/and previous hospitalization abroad. Klebsiella pneumoniae isolates belonged to “high risk” clones ST147, ST11, and ST15, while the Escherichia coli isolate was assigned to ST167. All isolates expressed resistance against most β-lactams, including carbapenems, while retaining susceptibility to colistin. Furthermore, analysis of WGS data showed that all four isolates co-produced OXA-48- and NDM-type carbapenemases, in different combinations (Kpn47733: blaNDM–5 + blaOXA–181; Kpn50595: blaNDM–1 + blaOXA–181; Kpn51015: blaNDM–1 + blaOXA–244; Eco52418: blaNDM–5 + blaOXA–244). In Kpn51015, the blaOXA–244 was found on plasmid p51015_OXA-244, while the respective gene was localized in the chromosomal contig of E. coli Eco52418. On the other hand, blaOXA–181 was identified on a ColKP3 plasmid in isolate Kpn47733, while a blaOXA–181-carrying plasmid being an IncX3-ColKP3 fusion was identified in Kpn50595. The blaNDM–1 gene was found on two different plasmids, p51015_NDM-1 belonging to a novel IncH plasmid group and p51015_NDM-1 being an IncFK1-FIB replicon. Furthermore, the blaNDM–5 was found in two IncFII plasmids exhibiting limited nucleotide similarity to each other. In both plasmids, the genetic environment of blaNDM–5 was identical. Finally, in all four carbapenemase-producing isolates, a diverse number of additional replicons, some of these associated with important resistance determinants, like blaCTX–M–15, arr-2 and ermB, were identified. In conclusion, this study reports the first description of OXA-244-producing Enterobacterales isolated from Czech hospitals. Additionally, our findings indicated the genetic plurality involved in the acquisition and dissemination of determinants encoding OXA/NDM carbapenemases.

scholarly journals Prevalence of Fosfomycin Resistance among CTX-M-Producing Escherichia coli Clinical Isolates in Japan and Identification of Novel Plasmid-Mediated Fosfomycin-Modifying Enzymes

2010 ◽  
Vol 54 (7) ◽  
pp. 3061-3064 ◽  
Author(s):  
Jun-ichi Wachino ◽  
Kunikazu Yamane ◽  
Satowa Suzuki ◽  
Kouji Kimura ◽  
Yoshichika Arakawa
Keyword(s):  
Escherichia Coli ◽  
The Other ◽  
Clinical Isolates ◽  
Clinical Settings ◽  
Transferase Activity ◽  
The Novel ◽  
Resistance Determinants ◽  
Other Hand ◽  
Fosfomycin Resistance

ABSTRACT We evaluated the in vitro activity of fosfomycin against a total of 192 CTX-M β-lactamase-producing Escherichia coli strains isolated in 70 Japanese clinical settings. Most of the isolates (96.4%) were found to be susceptible to fosfomycin. On the other hand, some of the resistant isolates were confirmed to harbor the novel transferable fosfomycin resistance determinants named FosA3 and FosC2, which efficaciously inactivate fosfomycin through glutathione S-transferase activity.

Penentuan Tempoh Kritikal Untuk Mengawal Rumpai dalam Kawasan Penanaman Padi Wangi MRQ 76, Q 88 dan Q 89

2014 ◽  
Vol 70 (6) ◽  
Author(s):  
Chong Tet Vun ◽  
Azimah Abd Kadir ◽  
Azmi Man ◽  
Chew See Eng ◽  
Baharudin Abas ◽  
...  
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Slow Growth ◽  
The Other ◽  
Fragrant Rice ◽  
Other Hand ◽  
Hot Climate ◽  
Competition Ability ◽  
Loss Level

A study on critical period (CP) for weed control in fragrant rice MRQ 76, Q 88 and Q 89 was conducted in main season 2012/2013 and off season 2013 at MARDI Seberang Perai. The results showed that the CPs (based on 5% acceptable yield loss level (AYL)) for weed control of MRQ 76, Q 88 and Q 89 planted in main season were from 5 to 64, 13 to 68 and 8 to 66 DAS (Days after sowing), respectively. On the other hand, CPs of MRQ 76, Q 88 and Q 89 planted in off season were from 6 to 73, 9 to 81 and 3 to 83 DAS, respectively. If based on 10% AYL, CPs of MRQ76, Q 88 and Q 89 planted in main season were from 19 to 38, 28 to 41 and 14 to 53 DAS, respectively. CPs (based on 10% AYL) of MRQ76, Q 88 and Q 89 planted in off season were from 15 to 55, 19 to 68 and 10 to 66 DAS, respectively. The study clearly demonstrated that CPs of off season were longer than CPs of main season. The dry and hot climate in off season probably caused the slow growth of fragrant rice and eventually affected the competition ability of rice against the weeds. 

scholarly journals The Serine 31 Residue of the B Subunit of Shiga Toxin 2 Is Essential for Secretion in Enterohemorrhagic Escherichia coli

2007 ◽  
Vol 75 (5) ◽  
pp. 2189-2200 ◽  
Author(s):  
Takeshi Shimizu ◽  
Satomi Kawakami ◽  
Toshio Sato ◽  
Terumi Sasaki ◽  
Masato Higashide ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Enterohemorrhagic Escherichia Coli ◽  
The Other ◽  
Supernatant Fraction ◽  
Isogenic Mutant ◽  
B Subunit ◽  
Related Information ◽  
Other Hand ◽  
Shiga Toxin 2

ABSTRACT Shiga toxins produced by enterohemorrhagic Escherichia coli (EHEC) include Shiga toxin 1 (Stx1) as well as Shiga toxin 2 (Stx2). Stx1 is cell associated, whereas Stx2 is localized to the culture supernatant. We have analyzed the secretion of Stx2 by generating histidine-tagged StxB (StxB-H). Although neither StxB1-H nor StxB2-H was secreted in StxB-H-overexpressed EHEC, StxB2-H-overexpressed EHEC showed inhibited Stx2 secretion. On the other hand, StxB1-H-overexpressed EHEC showed no alteration of Stx2 secretion. B-subunit chimeras of Stx1 and Stx2 were used to identify the specific residue of StxB2 that the Stx2 secretory system recognizes. Alteration of the serine 31 residue to an asparagine residue (S31N) in StxB2-H enabled the recovery of Stx2 secretion. On the other hand, alteration of the asparagine 32 residue to a serine residue (N32S) in StxB1-H caused the partial secretion of a point-mutated histidine-tagged B subunit in EHEC. Based on the evidence, it appeared possible that this residue might contain secretion-related information for Stx2 secretion. To investigate this hypothesis, we constructed an isogenic mutant EHEC (Stx1B subunit, N32S) strain and an isogenic mutant EHEC (Stx2B subunit, S31N) strain. Although the mutant Stx2 was cell associated in isogenic mutant EHEC, mutant Stx1 was not extracellular. However, when we used plasmids for the expression of the mutant holotoxins, the overexpressed mutant Stx1 was found in the supernatant fraction, and the overexpressed mutant Stx2 was found in the cell-associated fraction in mutant holotoxin gene-transformed EHEC. These results indicate that the serine 31 residue of the B subunit of Stx2 contains secretion-related information.

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