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Search Results: 1 - 10 of 4121 matches for " pathogenic bacteria "
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Actividad antibacteriana de extracto de hojas de Melia azedarach L.
Rojas Sierra,Johanna Norela; Pérez Cordero,Alexander Francisco; Martínez Avilez,Jose Gregorio; Mieles Galindo,Jorge Ulises;
Revista Colombiana de Biotecnología , 2012,
Abstract: the work was objective to evaluate the antibacterial activity of extracts from leaves of melia azedarach (l) on six pathogenic bacteria. total ethanol extract was obtained initially by extraction with method soxhlet and from this prepared liquid-liquid fractions with petroleum ether and ethyl acetate. the total extract and the two fractions were diluted at different concentrations (ppm) to evaluate its antibacterial activity in vitro. more susceptible bacteria were the pathogenic human enterococcus faecalis, escherichia coli, pseudomonas aeruginosa and klebsiella oxytoca, in relation to the plant pathogen burkholderia glumae who showed resistance to all treatments. pathogenic bacteria were more susceptible to the fraction of petroleum ether to the minimum concentration of 25 ppm. screen plant phytochemical indicated presence of secondary metabolites type alkaloids, terpenes/sterols, saponins, tannins and anthocyanins. these results demonstrate the potential use of m. azederach as biological control alternatively on analysed bacterial.
Phytochemical Determination and Antibacterial Activity of Punica granatum Peel Extracts against Plant Pathogenic Bacteria  [PDF]
Ayad Ismael Khaleel, Kamaruzaman Sijam, Tavga Sulaiman Rashid, Khairulmazmi Bin Ahmad
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.71017
Abstract: Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control agent for plant pathogenic bacteria. P. granatum peel was successfully extract using n-hexane, methanol and ethyl acetate by maceration. The highest yield obtained by ethyl acetate showed that ethyl acetate extracted more compounds that readily soluble to methanol and n-hexane. For in-vitro antibacterial activity, three different species of plant pathogenic bacteria were used namely Erwinia carotovorum subsp. Carotovorum, Ralstonia solanacearum, and Xanthomonas gardneri. For all crude extracts, four different concentrations 25, 50, 100 and 200 mg/ml were used in cup-plate agar diffusion method. Streptomycin sulfate at concentration 30 μg/ml was used as positive control while each respective solvent used for peel extraction was used as negative control. The results obtained from in vitro studies showed only ethyl acetate extract possessed antibacterial activity tested on the plant pathogenic bacteria. Methanol and n-hexane did not show any antibacterial activity against plant pathogenic bacteria selected where no inhibition zones were recorded. R. solanacearum recorded the highest diameter of inhibition zones for all range of concentrations introduced followed by E. carotovorum subsp. Carotovorum and X. gardneri. For the minimum inhbitory concentration (MIC) and minimum bactericidal concentration (MBC), only the ethyl acetate extract was subjected to the assay as only ethyl acetate extract exhibited antibacterial activity. The minimum concentration of ethyl acetate extract that was able to inhibit plant pathogenic bacteria was recorded at a concentration of 3.12 mg/ml which inhibited R. solancearum and E. carotovorum subsp. Carotovorum, followed by X. gardneri at concentration 6.25 mg/ml. For the minimum bactericidal concentration (MBC), the results showed that at the concentration of 12.5 mg/ml, the extract was still capable of killing the pathogenic bacteria, R. solanacearum, and P. caratovora sub.sp. caratovora while for the bacteria X. gardneri, the concentration that was able to kill the bacteria was 25 mg/ml. The qualitative estimation of phytochemical constituents within P. granatum L. ethyl acetate peel extracts had revealed the presence of tannins, flavonoids, phenols alkaloid, Saponins, and terpenoids. This
Synergistic Effect of Combined Antibiotics against Some Selected Multidrug Resistant Human Pathogenic Bacteria Isolated from Poultry Droppings in Akure, Nigeria  [PDF]
Funmilola Oluyemi Omoya, Kehinde Oluyemi Ajayi
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.614100
Abstract:
Antibiotic resistant bacteria pass between humans, between animals and between humans and animals in both directions, the use of antibiotics in poultry has contributed to multiple antibiotic resistant in pathogenic bacteria and use of two antibiotics might prevent the emergence of resistance to either. In this study, synergistic effect of combined antibiotics against multidrug resistant human pathogenic bacterial isolates from poultry droppings in Akure, Nigeria was examined. Collection of samples, isolation and identification of bacteria were carried out using standard microbiological method, antibiotic sensitivity test was performed by disc diffusion method and zone of inhibition was used to interpret the sensitivity test as resistant, susceptible or intermediate while combined effects of two antibiotics were investigated by macrobroth dilution and checkerboard assay methods while the synergetic effects of combined antibiotics were calculated using Fractional Inhibitory Concentration (FIC) and percentage synergistic interaction was calculated. All the ten (10) species of bacterial isolates were multidrug resistant and are less resistant to ofloxacin. The highest percentage synergistic interactions observed were Ofloxacin + Amoxicillin (90%), Ciprofloxacin + Amoxicillin (90%), Tetracycline + Amoxicillin (70%), Tetracycline + Augmentin (80%), Cotrimoxazol + Amoxicillin (50%), Cotrimoxazol + Augmentin (70%), Chloramphenicol + Amoxicillin (70%) and Chloramphenicol + Augmentin (80%). Poultry droppings is a potential source of human pathogenic bacteria, high frequency of multiple antibiotic resistance bacteria observed in this study is of great treat to man as this may cause the treatment of infection caused by these bacteria to be difficult. Combination of beta-lactam antibiotic with fluoroqunolones, tetracycline, Chloramphenicol and Cotrimoxazole was synergetic and this will reduce dose related toxicity and prevent resistance to single antibiotic.
Genomic research for important pathogenic bacteria in China
RuiFu Yang,XiaoKui Guo,Jian Yang,YongQiang Jiang,Bo Pang,Chen Chen,YuFeng Yao,JinHong Qin,QingTian Li
Science China Life Sciences , 2009, DOI: 10.1007/s11427-009-0009-4
Abstract: Rapid accumulation of bacterial genomic data offered an unprecedented opportunity to understand bacterial biology from a holistic view of point. We can thus closely look at the way in which a pathogen is evolved, and these data has been applied to molecular epidemiology and microbial forensics, and screening of novel diagnostic, vaccine and drug targets. The newly developed high-throughput low-cost sequencing technologies, such as 454, Solexa and SOLiD, will promote the acquisition and application of genomic data in new research areas that we dared not imagine previously, such as the metagenomics of human gastric-intestinal tract, for better and comprehensive understanding of human health and disease.
Análisis de Pseudomonas Fitopatógenas Usando Métodos Inteligentes de Aprendizaje: Un Enfoque General Sobre Taxonomía y Análisis de ácidos Grasos Dentro del Género Pseudomonas
Slabbinck, Bram;De Baets, Bernard;Dawyndt, Peter;De Vos, Paul;
Revista mexicana de fitopatología , 2010,
Abstract: the identification of plant-pathogenic bacteria is often of high importance. in this paper, we evaluate the identification of plant-pathogenic species within the genus pseudomonas by fatty acid methyl ester (fame) analysis. starting from a fame database, high quality data sets were generated. two research questions were investigated: can plant-pathogenic pseudomonas species be discriminated from each other and can the group of plant-pathogenic pseudomonas species be distinguished from the group of non-plant-pathogenic pseudomonas species. in a first stage, a principal component analysis was performed to evaluate the variability within the data. secondly, the machine learning method random forests was evaluated for identification purposes. this intelligent method allows to learn from the variability and patterns in the data and to improve the species identification. the principal component analysis of plant-pathogenic species clearly showed overlapping data clouds. a random forests model was developed that achieved a species identification performance of 71.1%. discriminating the group of plant-pathogenic plant-pathogenic species from the group of non-plant-pathogenic species was more straightforward, given by the random forests identification performance of 85.9%. moreover, it was shown that a statistical relation exists between the fatty acid profiles and plant pathogenesis.
Microbiological Safety of Raw Milk in Khartoum State, Sudan: 1-Khartoum and Omdurman Cities
Asmahan Azhari Ali,N.B. Irshad,S.A. Razaz,A.A. Manahil
Pakistan Journal of Nutrition , 2010,
Abstract: Twenty four random samples of raw cow milk were collected from Khartoum and Omdurman Cities. Samples were analyzed for microbiological population, included Total Plate Count (TPC), Total Coliforms (TC), Escherichia coli, Staphylococcus aureus, Salmonella, Lactic Acid Bacteria (LAB) and spore forming bacteria. Microbiological enumeration revealed for the counts of total mesophilic aerobic bacteria, 5.86 log cfu/ml; lactic acid bacteria, 4.47 log cfu/ml; coliforms 2.76 log cfu/ml; E. coli 1.63 log cfu/ml; Staphylococcus aureus, 1.92 log cfu/ml and 2.38 log cfu/ml Spore forming bacteria. The microbial profiles found had non-conformance to the Standard. Based on the exceedingly high microbial counts found in this study, it could be concluded that this milk type poses a serious health risk in the study areas.
In vitro Antibacterial Activity of the Extracts and a Glycoside from Sida rhombifolia Linn
Md. Ekramul Islam,Naznin Ara Khatune,Md. Ekramul Haque
Journal of Medical Sciences , 2002,
Abstract: The research work was conducted to investigate the in vitro anti-bacterial activity of a glycoside, phenyl ethyl β-D-glucopyranoside, isolated from the stem of the plant Sida rhombifolia. The petroleum ether (C2H5-O-C2H5), chloroform (CHCl3) and ethylacetate (CH3-CO-O-C2H5) extracts of the plant were screened against eleven pathogenic bacteria for their antimicrobial activities. The test materials were found to be significant in vitro antibacterial activities, against most of the test bacteria. The zones of inhibition produced by the test materials were found to be between 8 and 24 mm. The minimum inhibitory concentration (MIC) values of the isolated compound was also determined against Bacillus subtilis, Sarcinia lutea, Escherichia coli and Shigella shiga which were 128, 64, 64 and 128 μg ml-1, respectively.
Pathogenic and opportunistic respiratory bacteria-induced apoptosis
Lancellotti, Marcelo;Pereira, Rafaella Fabiana Carneiro;Cury, Gisele Gentile;Hollanda, Luciana Maria de;
Brazilian Journal of Infectious Diseases , 2009, DOI: 10.1590/S1413-86702009000300014
Abstract: several pathogenic or opportunistic bacteria have the ability to either induce or inhibit host cell apoptosis. the capacity to modulate cell pathways that result in the induction or delay of host cell apoptosis is considered to be an important bacterial virulence mechanism. these processes could be mediated by different host cell signaling pathways that are subverted by the bacteria. pathogens are able to activate apoptotic proteins, such as caspases, or inactivate anti-apoptotic proteins, such as nfkb and the mapkks, or even up-regulate the endogenous receptor/ligand system that induces apoptosis, generally when the bacteria are bound to the host cell surface. the bacteria-induced apoptotic or anti-apoptotic processes are often related with the fact that the bacteria acquire the ability to reach the host tissues. however, apoptosis is also considered to be a host defense mechanism against infectious agents. thus, the apoptosis phenomenon plays a central role in host-pathogen interactions.
Pathogenic Bacteria Associated with Different Public Environmental Sites in Mecca City  [PDF]
Samy S. Ashgar, Hamdy M. El-Said
Open Journal of Medical Microbiology (OJMM) , 2012, DOI: 10.4236/ojmm.2012.24020
Abstract: Background: The hygiene of environmental surfaces from shopping, ATM machines, telephones and computers and miscellaneous sites play role in spreading fecal and total coliform bacteria as well as pathogenic bacteria. Objectives: This study addresses the contaminated common sites by pathogenic or potentially pathogenic bacteria in Mecca, SA. Materials and Methods: A total 648 swab samples were collected and analyzed for presence or absence of pathogenic bacteria. Results: Of the total samples 422 were negative bacterial count (71%) and 226 (29%) were positive. All collected samples (100%) of glass windows in the fish markets were bacterial counted; most dominated was Bacillus spp. (n = 97) and the highest population of species was Enterococcus faecalis (n = 40) and E. coli (n = 16). Conclusion: Some public sites were very contaminated with different types of fecal coliform group of bacteria such as shopping cart handles, inner surfaces and child seats in supermarkets, and the glass windows in the fish market. Acinetobacter haemolyticus and other hemolytic bacteria were isolated from more than site.
Evaluación del efecto del cultivo probiótico Lactobacillus rhamnosus adicionado a yogurt natural y con probióticos comerciales sobre poblaciones de Staphylococcus aureus, Escherichia coli O157:H7, Listeria monocytogenes y Salmonella enteritidis
Calderón,Oscar; Padilla,Carolina; Chaves,Carolina; Villalobos,Laura; Laura Arias,María;
Archivos Latinoamericanos de Nutrición , 2007,
Abstract: evaluation of the effect of lactobacillus rhamnosus probiotic culture added to yogurt over staphylococcus aureus, escherichia coli o157:h7, listeria monocytogenes and salmonella enteritidis populations. the effect of different types of probiotics present in yogurt over known populations of staphylococcus aureus, escherichia coli o157:h7, listeria monocytogenes and salmonella enteritidis was evaluated. the three types of yogurt used were: without added probiotics, with added probiotics (lactobacillus casei crl_431 and l. acidophilus crl_730 chr hansen?) and another one with the same probiotics mentioned above and lactobacillus rhamnosus (lr-35) culture. about 109 cfu/ ml of each potentially pathogenic bacteria was added to each type of yogurt tested, and kept in refrigeration at 4oc during its shelf life, about 30 days. bacterial count was done the initial day and every four days. results obtained show that there is a difference in the inhibition between yogurts without added probiotics and the commercial yogurt with added probiotics; there is a clear inhibitory effect of the last one over s. aureus, e coli o157:h7 and listeria monocytogenes. the yogurt with added probiotics and l. rhamnosus did not show any additional inhibitory effect over the bacteria tested when compared with the yogurt with added probiotics. s. enteritidis could not be evaluated because it was not detectable in any yogurt samples evaluated four days after its inoculation. this study confirms the antagonic effect of probiotic cultures over potentially pathogenic bacteria for human beings and animals that may be present in food. nevertheless, the use of l. rhamnosus did not produce any additional inhibitory effect.
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