Esherichia Coli Research Articles

Research on the production of the kit for rapid detection of Vibrio cholerae in water

Vibrio cholerae is a causative agent of the epidemic diarrheal. Vibrio cholerae is a noninvasive organism affecting the small intestine through the secretion of the enterotoxin. For rapid detection of Vibrio cholerae, we have developed the kit based on PCR amplification of the gene encoding enterotoxin (ctx) of this agent. The bacteria is captured from water by the bacterial filter with the aid of a pump and enriched in the specific medium for Vibrio cholerae. The genetic material are released from bacteria by heat treatment and the specific fragment is amplified by PCR. The kit has been tested with different enterobacteria such as Esherichia coli, Salmonella typhi, Shigella flexneri and the result showed that the test was sensitive and specific for the Vibrio cholerae detection.

POTENTIAL IN VITRO ANTI-HELICOBACTER ACTIVITY OF BACTERIOCIN AND BACTERIOCIN-LIKE COMPOUNDS PRODUCED BY LACTOBACILLI

The study was designed for screening of the potential activity of lactic acid bacteria against Helicobacter pylori and other enteropathogenic organisms. A total of 40 samples including natural cow milk and fresh infant stools were tested for the presence of lactic acid bacteria. Of these samples, 73 lactic acid bacterial isolates were recovered on MRS agar medium using the streak-plate method. Isolates inducing probiotic effect were tested under microaerophilic conditions against standard cultures of H. pylori, Esherichia coli and Salmonella enteritidis. The data obtained showed that five isolates of lactic acid bacteria were able to produce bacteriocin or bacteriocin-like compounds. Sequencing of 16S rRNA gene revealed that five isolates belonged to Lactobacillus rhamnosus and Lactobacillus plantarum in addition to other lactic acid bacteria. The most effective isolate (LAB1) showed a marked large inhibition zone against H. pylori. The bacteriocin or bacteriocin like compound(s) produced by lactobacilli were further analyzed and characterized. We can conclude that probiotics might be useful in the prophylaxis or as co-therapy for treatment of H. pylori infections.

ANTIMICROBIAL ACTIVITY OF FLAVONOID COMPOUND ISOLATED FROM INULA GREAVEOLENS L. PLANT ON SELECTED PATHOGENIC BACTERIA

The antibacterial activity of the flavonoid compound (B3) isolated from Inula greaveolens plant by column – chromatography was determined against several of clinical microbial isolates including Gram positive: ( Streptococcus spp. Staphylococcus aureus ) and isolates of Gram negative : ( Klebsiella pneumonia, Pseudomonas aeroginosa and Esherichia coli ) by using three concentrations of the extract (125 mg /ml , 250mg /ml ,500 mg /ml ).The results revealed that the falvonoid compound B3 has varying degrees of inhibition tested microorganisms. The cytotoxic activity of the falvonoid compound (B3) was determined against the fresh human red blood celles with several concentrations of the extract and the results shown that flavonoid compound did not had toxicity against the human red blood cells.

Determinants of quinolone resistance in Escherichia coli causing community-acquired urinary tract infection in Bejaia, Algeria

ObjectiveTo investigate the mechanisms of quinolone resistance and the association with other resistance markers among Esherichia coli (E. coli) strains isolated from outpatient with urinary tract infection in north of Algeria. MethodsA total of 30 nalidixic acid-resistant E. coli isolates from outpatient with urinary tract infections from January 2010 to April 2011 in north of Algeria (Bejaia) were studied. Antimicrobial susceptibility was determined by disc diffusion assay, minimal inhibitory concentrations (MIC) of quinolone were determined by microdilution. Mutations in the Quinolone Resistance-Determining Region (QRDR) of gyrA and parC genes and screening for qnr (A, B and S) and bla genes were done by PCR and DNA sequencing. ResultsMost of the E. coli isolates (56.66%) were shown to carry mutations in gyrA and parC (gyrA: Ser83Leu + Asp87Asn and parC:Ser80Ile). While, 16.66% had only an alteration in gyrA: Ser83Leu. One isolate produced qnrB-like and two qnrS-like. Four isolates were CTX-M-15 producers associated with TEM-1 producing in one case. Co-expression of blaCTX-M-15 and qnrB was determined in one E. coli isolate. ConclusionsOur findings suggested the community emergence of gyrA and parC alterations and Qnr determinants that contributed to the development and spread of fluoroquinolone resistance in Algerian E. coli isolates.

Synthesis, Characterization and Biological Activity of Some Ferrocenyl Complexes Containing Antipyrine Moiety

Manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), mercury(II) and lead(II)complexes of ferrocenyl Schiff base ligand containing antipyrine moiety were prepared in a good yield. They were characterized using IR, 1H NMR, UV/Vis., mass spectra, magnetic susceptibility and molar conductivity measurements as well as elemental analysis. The analyses showed that the ligand behaved as neutral tetradentate ligand coordinated to the metal ions via the carbonyl oxygen and azomethine nitrogen atoms forming an octahedral geometry around the metal ions. The biological activity of the ligand and its complexes were carried out against fungal strains of Aspergillus niger and bacterial strains of Bacillus subtilis (+ve), Esherichia coli (-ve) using the disk diffusion method. The biological results indicated that the ligand is inactive while its complexes have mild activity. The complexes showed mild antibacterial activity against Bacillus subtilis (+ve), Esherichia coli (-ve) and Aspergillus niger (fungi). The biological results are compared with a standard drugs.

Evaluation of systemic and mucosal immune responses in mice administered with novel recombinant Salmonella vaccines for avian pathogenic Esherichia coli

Abstract : Avian pathogenic Escherichia coli (APEC) is a causative agent for a number of extra intestinal diseasesand account for significant losses to the poultry industry. Since protective immunity against APEC is largely directedto virulence antigens, we have individually expressed four different viulence antigens, papA, papG, IutA, and CS31A,using an attenuated Salmonella Typhimurium and a plasmid pBB244. Following oral immunization of mice withcombination of two or four of these strains, serum IgG and mucosal IgA responses were elicited against eachantigen represented in the mixture. The antigen-specific mucosal IgA responses were significantly higher in thegroup of mice immunized with the heat-labile Escherichia coli enterotoxin B subunit (LTB) strain than those inthe group of mice immunized without the LTB strain. While, there was no significant difference between thesetwo groups in antigen-specific serum IgG responses. The results showed that LTB could act as mucosal immuneadjuvant. To assess the nature of immunity, the distribution of antigen-specific IgG isotypes was analyzed. Allgroups promoted Th1-type immunity as determined by the IgG2a/IgG1 ratio. Thus, our findings provided evidencethat immunization with a combination of several vaccine strains is one of the strategies of developing effectivevaccines against APEC.Keywords : Avian pathogenic Escherichia coli, heat-labile Escherichia coli enterotoxin B subunit, immune response,pBB244, Salmonella vaccine delivery

Comparison of the antibacterial activity of essential oils and extracts of medicinal and culinary herbs to investigate potential new treatments for irritable bowel syndrome

BackgroundIrritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, which may result from alteration of the gastrointestinal microbiota following gastrointestinal infection, or with intestinal dysbiosis or small intestinal bacterial overgrowth. This may be treated with antibiotics, but there is concern that widespread antibiotic use might lead to antibiotic resistance. Some herbal medicines have been shown to be beneficial, but their mechanism(s) of action remain incompletely understood. To try to understand whether antibacterial properties might be involved in the efficacy of these herbal medicines, and to investigate potential new treatments for IBS, we have conducted a preliminary study in vitro to compare the antibacterial activity of the essential oils of culinary and medicinal herbs against the bacterium, Esherichia coli.MethodsEssential oils were tested for their ability to inhibit E. coli growth in disc diffusion assays and in liquid culture, and to kill E. coli in a zone of clearance assay. Extracts of coriander, lemon balm and spearmint leaves were tested for their antibacterial activity in the disc diffusion assay. Disc diffusion and zone of clearance assays were analysed by two-tailed t tests whereas ANOVA was performed for the turbidometric assays.ResultsMost of the oils exhibited antibacterial activity in all three assays, however peppermint, lemon balm and coriander seed oils were most potent, with peppermint and coriander seed oils being more potent than the antibiotic rifaximin in the disc diffusion assay. The compounds present in these oils were identified by gas chromatography mass spectrometry. Finally, extracts were made of spearmint, lemon balm and coriander leaves with various solvents and these were tested for their antibacterial activity against E. coli in the disc diffusion assay. In each case, extracts made with ethanol and methanol exhibited potent antibacterial activity.ConclusionsMany of the essential oils had antibacterial activity in the three assays, suggesting that they would be good candidates for testing in clinical trials. The observed antibacterial activity of ethanolic extracts of coriander, lemon balm and spearmint leaves suggests a mechanistic explanation for the efficacy of a mixture of coriander, lemon balm and mint extracts against IBS in a published clinical trial.

Requirement of Catalytic-Triad and Related Amino Acids for the Acyltransferase Activity ofTanacetum cinerariifoliumGDSL Lipase/Esterase TcGLIP for Ester-Bond Formation in Pyrethrin Biosynthesis

We have recently discovered that a GDSL lipase/esterase (TcGLIP) in Tanacetum cinerariifolium catalyzed acyltransferase activity to form an ester bond in the natural insecticide, pyrethrin. TcGLIP contained Ser40 in Block I, Gly64 in Block II, Asn168 in Block III and Asp318 and His321 in Block V, suggesting underlying hydrolase activity, although little is known about their role in acyltransferase activity. We expressed TcGLIP here in Esherichia coli as a fusion with maltose-binding protein (MBP), part of the fusion being cleaved with a protease to obtain MBP-free TcGLIP. A kinetic analysis revealed that the MBP moiety scarcely influenced the kinetic parameters. The effects on acyltransferase activity of mutations of Gly64, Asn168, Asp318 and His321 were investigated by using MBP-fused TcGLIP. Mutations of these amino acids markedly reduced the acyltransferase activity, suggesting their critical role in the production of pyrethrins.

Antibacterial Effects In Vitro of Several Common Chinese Medicinal Herbs Upon Esherichia coli

Antibacterial Effects <i>In Vitro</i> of Several Common Chinese Medicinal Herbs Upon <i>Esherichia coli</i>

Use of enoyl coenzyme A hydratase of Mycobacterium avium subsp. paratuberculosis for the serological diagnosis of Johne's disease

Johne's disease (JD), caused by Mycobacterium avium subspecies paratuberculosis (MAP), remains difficult to control because of the lack of specific and sensitive diagnostic tests. In order to improve the specificity of sero-diagnosis for JD, the phage display library derived from genomic DNA of MAP was immunoscreened to identify novel antigenic targets. We selected a clone using antibodies from MAP experimentally infected cattle, and annotated its coding sequence as MAP1197 in the MAP genome, which encoded “echA12_2” in the MAP protein (Map-echA) belonging to Enoyl-CoA hydratase, known as a crotonase enzyme. The Map-echA was expressed in Esherichia coli and purified as a histidine-tag recombinant protein (rMap-echA), and the diagnostic potential of the protein was further evaluated by enzyme-linked immunosorbent assays (ELISA). Antibody responses to rMap-echA were higher in MAP-infected cattle than in uninfected cattle. The specificity of the Map-echA ELISA was also confirmed by evaluation with hyper-immune sera against various kinds of Mycobacterium species. Furthermore, in all experimentally infected cattle the antibody against rMap-echA was detected 2–7months earlier than by a commercially available ELISA kit. These results suggested that Map-echA can be used as a specific and sensitive serological diagnostic antigen for the detection of MAP infection.

Phytochemical screening and antibacterial properties of Garcinia kola

Extract of bark, seed and root of Garcinia kola were used to determine the antibacterial properties of the extract as well as determine which extract is most effective. Methanol and ethanol were used for the extraction. Minimum inhibitory concentration (MIC; mg/ml) of the extract as well as zones of inhibition of the extract were determined. Results show that the extracts from bark of Garcinia kola contain higher % Saponins (3.2±0.04), while the root contain higher % of phenol (0.44±0.11). Bark extract of Garcinia kola was more effective in inhibiting the growth of Pseudomonas auraginosa, Esherichia coli and Staphylococcus aureus when compared with the extract from the root and seed. Results also show that inhibition of the test extract in (mm) was higher in extract from the bark, followed by the seed and the least zone of inhibition was found in the root extracts. The variation in the antibacterial activities is presumed to be due to different active compounds present in the extract.

Antibacterial activity of ZygophllumfabagoL. Leaves extracts

The present research consist of qualitative chemical analysis for both aqueous and alcoholic extracts of Zygophyllumfabagoleaves which showed that the glycosides, alkaloids, flavonoids, terpens and steroids were found in both extracts, while saponines and phenolic compounds were found in alcoholic extract only, and both extracts contain no tannins. The other part of research was the determination of the antimicrobial activity of these extracts against eight species of pathogenic bacteria (Esherichia coli, Klebsilla Pneumonia, Proteus volgaris, Proteus mirabilis, Salmonella Sp., Pseudomonas aeruginosa, Streptococcus Pyogens, Staphyllococcusaureus) with six different concentration began with 40 mg/ml to 100 mg/ml by using agar well diffusion method which showed that alcoholic extracts more effective than aqueous ones and that both Staphyllococcousaureusand Escherishia coli were the most affected species.

The Antimicrobial Activity and the Median Lethal Dose of Thyme (Thymus vulgaris) Ethanolic Extract on Mice

The antimicrobial activities of thyme (thymes vulgaris) ethanolic extract was studied by agar well diffusion technique against tested organisms (Esherichia coli, Staphylococcus aureus and Candida albicans). The results were showed that the extract have antibacterial and antifungal activity against tested microorganisms. The results were also showed that the median lethal dose (LD50) of ethanolic extract of thyme in laboratory mice was about (4220 mg/kg B.w). The toxic signs during 24 hours after oral administration of thyme extract were rapid breathing, dullness, contraction of abdominal muscles, paralysis then death.

English

The purpose of this study was to determine the microbiological quality of retailmayonnaise-based salads&nbsp;samples.&nbsp;A total&nbsp;of 432 samples were collected between 1 February 2008 and 31 July&nbsp; 2009 in Ankara.&nbsp;In the present study, pH values of the samples were measured in the range of&nbsp;4.05-7.10 (average pH=5.69). The samples with pH higher than 4.6 (n=236/432, 54.6 %) were carried out for microbiological analysis.&nbsp;In the present study,&nbsp;the samples were analysed for the presence of total aerobic bacteria (TAB),Esherichia coli, Salmonella spp. and&nbsp;Staphylococcus aureus.&nbsp;According to microbiological analysis, TAB was detected in 210 of 236&nbsp;(89.4 %) retail mayonnaise based salads (range: 1.1x102-2.9&acute;106&nbsp;cfu/g).&nbsp;E.coli,&nbsp;Salmonella&nbsp;and&nbsp;S. aureus&nbsp;were detected in 143 (60.6.%) of 236 samples each, with a range of 1.3&acute;102-3.6&acute;104&nbsp;cfu/g, 2.4&acute;102-7.1&acute;104&nbsp;cfu/g (62 samples, 26.3%) and 1.8&acute;102-8.3&acute;103&nbsp;cfu/g (41 samples, 17.40%), respectively. The results indicate that the type of mayonnaise based salads analysed may contain pathogenic bacteria and thereby represent a risk to the consumers in regard to foodborne diseases. Thus, it is essential to include the effective hygiene practices as an important safety measure in the production of mayonnaise- based salads. &nbsp; Key words:&nbsp;Mayonnaise-based salads, microbiological analysis, pathogens.

Investigation of the final stages of a P4-like coliphage infection in Escherichia coli through scanning, transmission and nano-scanning-auger electron microscopy (NanoSAM)

Enlargement of bacterial cells during bacteriophage replication has been observed in the past with T-even, Lambda and N4 bacteriophages by the use of transmission electron microscopy (TEM) and light microscopy techniques and hypotheses explaining the enlargement of bacteriophage-infected cells have been postulated in literature. In this study, enlarged Escherichia coli cells were observed using scanning electron microscopy (SEM) after 45 min of a P4-like bacteriophage infection. These bacteria were also studied using scanning auger microscopy (SAM) in combination with anthe Argon-ion gunof a scanning Auger microscope (SAM) by which the bacteria were etched. Neither SEM nor SAM have been used during the analysis of bacteriophage infected enlarged host cells, making this study unique. The use of SAM on bacteriophage-related investigations is also novel. Small phage-like particles were observed inside the etched enlarged and etched normal bacteriophage-exposed host cells. The presence of bacteriophage-like particles inside both types of cells confirmed that the enlarged cells, which were scarce in this sample, were not artifacts of some kind such as contamination by other microorganisms. Due to the scarcity of these enlarged cells, it was concluded that a previous hypothesis on tThe enlargement of bacteriophage infected host cells coincides with previous studies reported in literature, did not apply to thebut never before with P4-like bacteriophages. used in this study. Key words: Bacteriophage, coliphage, replication cycle, Esherichia coli, Nano scanning electron microscopy.

Antimicrobial activity of leaf and flower extracts of Lippia Nodiflora L. (Verbenacea)

Abstract Antimicrobial activities of the methanolic extracts from the leaves and flowers of Lippia nodiflora L. (Verbenaceae), were studied by the disk diffusion method. The extracts showed antimicrobial impact on bacteria such as Bacillus subtilis, B. cereus, Micrococcus luteus, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, K. oxytoca and Esherichia coli as well as fungi such Aspergillus niger and Candida albicanse. The results showed that increasing concentrations of extracts increased the antimicrobial activities in all of the microorganisms. Bacteria were more sensitive than fungi, and gram positive bacteria were more sensitive than gram negative ones.

Variation in the annual unsatisfactory rates of selected pathogens and indicators in ready-to-eat food sampled from the point of sale or service in Wales, United Kingdom.

The Welsh Food Microbiological Forum "shopping basket" survey is a long running, structured surveillance program examining ready-to-eat food randomly sampled from the point of sale or service in Wales, United Kingdom. The annual unsatisfactory rates for selected indicators and pathogens for 1998 through 2008 were examined. All the annual unsatisfactory rates for the selected pathogens were <0.5%, and no pattern with the annual rate was observed. There was also no discernible trend observed for the annual rates of Listeria spp. (not moncytogenes), with all rates <0.5%. However, there was a trend observed for Esherichia coli, with a decrease in rate between 1998 and 2003, rapid in the first few years, and then a gradual increase in rate up to 2008. It was concluded that there was no discernible pattern to the annual unsatisfactory rates for Listeria spp. (not monocytogenes), L. monocytogenes, Staphylococcus aureus, and Bacillus cereus, but that a definite trend had been observed for E. coli.

IN VITRO INHIBITION ZONE TEST OF BINAHONG (ANREDERA CORDIFOLIA) TOWARDS STAPHYLOCOCCUS AUREUS, ENTEROCOCCUS FAECALIS, ESCHERICHIA COLI, AND PSEUDOMONAS AERUGINOSA

ABSTRACT This is a true experimental research with post test-only control group design. The study was conducted to test the inhibitory zone of the Binahong leaf extract (Anredera cordifolia) against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Binahong leaf extract is prepared using maceration technique, by soaking it in a sealed jar for 24 hours with 95% methanol. Then subsequently filtered using a funnel with filter paper, and the filtrate is collected inside an erlenmeyer. The filtrate then concentrated using a rotavapor, this concentrated extract dissolved into aquadest with a concentration of 50 ppm, 100 ppm and 1000 ppm. By taking a few colonies with a sterile loop into a stock of Staphylococcus aureus, Enterococcus faecalis, Esherichia coli, Pseudomonas aeruginosa then scratch it into MH blood agar medium, and incubate it for 24 hours with a temperature of 370C. The next day, bacterial suspension was made in test tube, which already contains 0.9% NaCl. The suspension tturbidity is equivalent to 0.5 Mc Farland. Bacterial inhibition zone of binahong leaf extract (Anredera cordifolia) is tested using absorbance disc method or better known as the Kirby-Bauer method. First, pour 10 ml of agar medium (± 400C) into a cup (petridish) and then wait until it’s cold. After the medium becomes solid, the suspension of bacteria Staphylococcus aureus, Enterococcus faecalis, Esherichia coli, and Pseudomonas aeruginosa are slowly smeared with sterile cotton sticks on the surface of the media. Soak the paper discs into binahong leaf extract (Anredera cordifolia) with concentrations of 50, 100, and 1000 ppm, for about 5 minutes, and placed it on the surface of the petridish, together with the positive control (amoxicillin) and negative control (aquadest). Then incubate it at 370C for 24 hours. The effectiveness of binahong leaf extract (Anredera cordifolia) inhibition zone, can be determined by measuring the diameter of clear zone around the paper using a sliding-term. Binahong leaf extract (Anredera cordifolia) zone of inhibition is negative, a very slight different is showed by the amoxicillin inhibition zone, for having a clear zone diameter of 28 mm for Staphylococcus aureus and Esherichia coli, and 21 mm for Enterococcus faecalis. This fact is probably caused by several things concerning the mechanism of action of a substance as an anti bacterial of the binahong leaf extract (Anredera cordifolia).Â

Microbiological Effectiveness of Mineral Pot Filters in Cambodia

Mineral pot filters (MPFs) are household water treatment (HWT) devices that are manufactured and distributed by the private sector, with millions of users in Southeast Asia. Their effectiveness in reducing waterborne microbes has not been previously investigated. We purchased three types of MPFs available on the Cambodian market for systematic evaluation of bacteria, virus, and protozoan surrogate microbial reduction in laboratory challenge experiments following WHO recommended performance testing protocols. Results over the total 1500 L testing period per filter indicate that the devices tested were highly effective in reducing Esherichia coli (99.99%+), moderately effective in reducing bacteriophage MS2 (99%+), and somewhat effective against Bacillus atrophaeus, a spore-forming bacterium we used as a surrogate for protozoa (88%+). Treatment mechanisms for all filters included porous ceramic and activated carbon filtration. Our results suggest that these commercially available filters may be at least as effective against waterborne pathogens as other, locally available treatment options such as ceramic pot filters or boiling. More research is needed on the role these devices may play as interim solutions to the problem of unsafe drinking water in Cambodia and globally.

892 Pediatricians Responsible for Early Detetction and Survelliance of Urinary Tract Infections from Infants to Preschool Children

IntroductionUrinary tract infections (UTI) represent substantial pathology of children’s morbidity. The frequency is just behind respiratory tract infections. The symptoms may be very diverse and non-specific. Early diagnosis very important...