Enterococcus Sp Research Articles

Toxic effect of high concentration of sonochemically synthesized polyvinylpyrrolidone-coated silver nanoparticles on Citrobacter sp. A1 and Enterococcus sp. C1.

Currently, silver nanoparticles (AgNPs) have gained importance in various industrial applications. However, their impact upon release into the environment on microorganisms remains unclear. The aim of this study was to analyze the effect of polyvinylpyrrolidone-capped AgNPs synthesized in this laboratory on two bacterial strains isolated from the environment, Gram-negative Citrobacter sp. A1 and Gram-positive Enterococcus sp. C1. Polyvinylpyrrolidone-capped AgNPs were synthesized by ultrasound-assisted chemical reduction. Characterization of the AgNPs involved UV-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. Citrobacter sp. A1 and Enterococcus sp. C1 were exposed to varying concentrations of AgNPs, and cell viability was determined. Scanning electron microscopy was performed to evaluate the morphological alteration of both species upon exposure to AgNPs at 1000mg/L. The synthesized AgNPs were spherical in shape, with an average particle size of 15nm. The AgNPs had different but prominent effects on either Citrobacter sp. A1 or Enterococcus sp. C1. At an AgNP concentration of 1000mg/L, Citrobacter sp. A1 retained viability for 6 hours, while Enterococcus sp. C1 retained viability only for 3 hours. Citrobacter sp. A1 appeared to be more resistant to AgNPs than Enterococcus sp. C1. The cell wall of both strains was found to be morphologically altered at that concentration. Minute and spherical AgNPs significantly affected the viability of the two bacterial strains selected from the environment. Enterococcus sp. C1 was more vulnerable to AgNPs, probably due to its cell wall architecture and the absence of silver resistance-related genes.

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The detection of bacteriocinogenic potential of Enterococcus sp. isolates from Algerian raw milk coded LO4 and LO12 and from traditional butter coded BRO2 was carried on M17 buffered medium. PCR amplification of Enterococcus sp. DNA using specific enterococcal primers gave 733 bp fragments. The phylogenetic analysis using the neighbour joining method further supported the identification of the three strains as Enterococcus faecium . These bacteria were bacteriocinogenic against Pseudomonas sp , Proteus mirabilis and E. faecium . Lyophilisate extracts were tested for sensitivity to enzymes, heating and effect of pH. Complete inactivation in bacteriocinogenic activity was observed after treatment with proteolytic enzymes. The antibacterial activity from E faecium LO12 was stable (1280 AU/ml) for range pH 2 to 12. Maximal activity from BRO2 strain was at pH 7 (20480 AU/ml) and from LO4 strain was at pH 7 and 6 (2560 AU/ml). Antibacterial activities of E. faecium BRO2 (5120 AU/ml) and E. faecium LO12 (640 AU/ml) remained stable at 60°C for 30 min. The antibacterial activity of . E faecium LO4 was stable at 100°C for 30 min (5120 AU/ml).

Beneficial effects of native phosphate solubilizing bacteria on peanut (Arachis hypogaea L) growth and phosphorus acquisition

This study analyses the effect of inoculation of native phosphate solubilizing bacteria on peanut (Arachis hypogaea L.) growth and phosphorus acquisition. Peanut plants were inoculated individually with 18 native phosphate solubilizing bacteria in microcosm studies using a low content P soil from the producing area. Survival of inoculated bacteria in soil at the end of the experiment was determined by streaking serial dilutions of dry soil samples and subsequent rep-fingering analysis of the colonies. The ability of peanut plants to increase P levels without bacteria was determined in hydroponic culture. The results obtained indicated that inoculation of native phosphate solubilizing bacteria on peanut seedlings led to an increase in at least one of the plant growth parameters analyzed. The beneficial effect of bacteria inoculation was mainly observed in aerial organs of peanut plants. Inoculation of Serratia sp. J260, Enterobacter sp. J33, Acinetobacter sp. L176, Enterococcus sp. L185, Enterococcus sp. L191 and Bacillus sp. L55 on peanut plants led to an increase in plant or soil P content. Plant assay in hydroponic conditions indicated that peanut plants growing with tricalcium phosphate were able to release soluble P into the growth medium reaching values similar to those of plants growing with available P. The beneficial effects of the bacteria analyzed in this study and their ability to survive encourage us to consider them for the production of a potential P-bioinoculant for peanut crops.

Characterization of the spoilage lactic acid bacteria in "sliced vacuum-packed cooked ham".

The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples.

Bioactivity and Molecular Docking of Secondary Metabolites produced byStreptomyces xanthochromogenesJAR5

The present investigation was aimed to explore in vitro and in silico antimicrobial potential of secondary metabolites produced by terrestrial actinomycetes, S. xanthochromogenes JAR5 isolated from deep forest of Kodaikanal, Tamil Nadu, India and was confirmed by 16S rRNA gene sequencing analysis. The bioactive metabolites produced by the strain JAR5 were obtained from the optimized culture medium through solvent extraction method. The crude extract obtained was purified using silica gel column chromatography and partially purified active elute was characterized using UV, FTIR and GC-MS spectroscopic analysis. The partially purified bioactive metabolites produced by strain JAR5 showed 23.333±0.471 diameter zone of inhibition and minimum inhibitory concentration of 80 μg/ml against Enterococcus sp. In silico molecular docking studies revealed binding into crystal structure of topoisomerase II using Autodock vina 4.2 program. The molecular docking of biological active compounds is in good agreement with in vitro antimicrobial screening where the bioactive metabolites showed effective inhibitory effect against Enterococcus sp.

Antibacterial and cytotoxic potential of silver nanoparticles synthesized using latex of Calotropis gigantea L.

The present study aimed to synthesis silver nanoparticles (AgNPs) in a greener route using aqueous latex extract of Calotropis gigantea L. toward biomedical applications. Initially, synthesis of AgNPs was confirmed through UV–Vis spectroscopy which shows the surface plasmonic resonance peak (SPR) at 420nm. Fourier transform infrared spectroscopy (FTIR) analysis provides clear evidence that protein fractions present in the latex extract act as reducing and stabilizing bio agents. Energy dispersive X-ray (EDAX) spectroscopy confirms the presence of silver as a major constituent element. X-ray diffractograms displays that the synthesized AgNPs were biphasic crystalline nature. Electron microscopic studies such as Field emission scanning electron microscopic (Fe-SEM) and Transmission electron microscope (TEM) reveals that synthesized AgNPs are spherical in shape with the size range between 5 and 30nm. Further, crude latex aqueous extract and synthesized AgNPs were evaluated against different bacterial pathogens such as Bacillus cereus, Enterococci sp, Shigella sp, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Compared to the crude latex aqueous extract, biosynthesized AgNPs exhibits a remarkable antimicrobial activity. Likewise invitro anticancer study manifests the cytotoxicity value of synthesized AgNPs against tested HeLa cells. The output of this study clearly suggesting that biosynthesized AgNPs using latex of C. gigantea can be used as promising nanomaterial for therapeutic application in context with nanodrug formulation.

Deglycosylation of isoflavone C-glycosides by newly isolated human intestinal bacteria.

Plant isoflavones are mostly present in the glycoside form. Isoflavone aglycones produced by intestinal microflora are reported to be more bioactive than the glycoside form. However, the deglycosylation of isoflavone C-glycosides is known to be rare, and is less studied. Three new bacteria were isolated from human faecal samples, two of which hydrolysed the C-glycosidic bond of puerarin, daidzein-8-C-glucoside. They were identified as two Lactococcus species, herein designated as MRG-IFC-1 and MRG-IFC-3, and an Enterococcus species, herein designated MRG-IFC-2, based on their 16S rDNA sequences. From a reactivity study, it was found that Lactococcus sp. MRG-IFC-1 and Enterococcus sp. MRG-IFC-2 hydrolysed isoflavone C- and O-glycosides, as well as the flavone O-glycoside apigetrin, but could not hydrolyse the flavone C-glycosidic bond of vitexin. The other Lactococcus sp., MRG-IF-3, could not hydrolyse the C-glycosidic linkage of puerarin, while it showed a broad substrate spectrum of O-glycosidase activity similar to the other two bacteria. Puerarin was completely converted to daidzein within 100 min by Lactococcus sp. MRG-IFC-1 and Enterococcus sp. MRG-IFC-2, which is the fastest conversion among the reported human intestinal bacteria. Two new puerarin-metabolising human intestinal bacteria were isolated and identified, and the deglycosylation activity for various flavonoid glycosides was investigated. The results could facilitate the study of C-glycosidase reaction mechanisms, as well as the pharmacokinetics of bioactive C-glycoside natural products.

Water microbial quality during drinking water treatment technology and distribution provided by two Romanian companies

Under European Economic Area Agreement, Romania and Norway have developed a project for monitoring the quality of raw and potable water (from production technology until distribution) supplied by two Romanian water companies. In the present study was investigated the microbiological quality of water, which was compared with organic matter loads. Resulting free chlorine and trihalomethane compounds after disinfection processes were also analysed. The raw water collected from Danube hydrographical basin showed significant pollution with potential pathogenic microorganisms with faecal origin such as Salmonella sp., Escherichia coli, Enterobacter sp., Klebsiella pneumoniae, Proteus mirabilis, Citrobacter braakii, Providencia stuartii, and Enterococcus sp. Also other bacteria such as Pseudomonas aeruginosa, Acinetobacter, total number of bacteria at 22 and 37 °C were detected, being related to high water oxidability. The microbial load was reduced considerably after the disinfection process. However, the total number of bacteria at 22 or 37 °C was constantly higher than the imposed limit and Clostridium perfringens was identified occasionally. The tap water presented a sporadic microbial loading with Enterococcus sp., Pseudomonas aeruginosa and E. coli and constantly with total number of bacteria due to an improper water distribution network.

The incidence and risk factors of meningitis after major craniotomy in China: a retrospective cohort study.

BackgroundMeningitis after neurosurgery can result in severe morbidity and high mortality. Incidence varies among regions and limited data are focused on meningitis after major craniotomy.AimThis retrospective cohort study aimed to determine the incidence, risk factors and microbiological spectrum of postcraniotomy meningitis in a large clinical center of Neurosurgery in China.MethodsPatients who underwent neurosurgeries at the Department of Neurosurgery in Huashan Hospital, the largest neurosurgery center in Asia and the Pacific, between 1stJanuary and 31st December, 2008 were selected. Individuals with only shunts, burr holes, stereotactic surgery, transsphenoidal or spinal surgery were excluded. The complete medical records of each case were reviewed, and data on risk factors were extracted and evaluated for meningitis.ResultsA total of 65 meningitides were identified among 755 cases in the study, with an incidence of 8.60%. The risk of meningitis was increased by the presence of diabetes mellitus (odds ratio [OR], 6.27; P = 0.009), the use of external ventricular drainage (OR, 4.30; P = 0.003) and the use of lumbar drainage (OR, 17.23; P<0.001). The isolated microorganisms included Acinetobacter baumannii, Enterococcus sp, Streptococcus intermedius and Klebsiella pneumonia.ConclusionsMeningitis remains an important source of morbidity and mortality after major craniotomy. Diabetic patients or those with cerebral spinal fluid shunts carry significant high risk of infection. Thus, identification of the risk factors as soon as possible will help physicians to improve patient care.

Production of mixed acids from non-pretreated red algae Gelidium amansii

The present study investigates the production of mixed acids by anaerobic fermentation using non-pretreated red algae Gelidium amansii as a substrate. The production levels of mixed acids were increased 1.6-fold in enrichment cultures of anaerobic digester sludge and tidal field soil compared with fresh sludge. The enrichment culture was composed of four major groups of microbial strains belonging to Clostridium sp. and Enterococcus sp. A defined mixed culture established based on the identified isolates increased mixed acids production level by up to 50.9% (g/g). Semi-continuous fermentation with a biomass-loading rate of 2.77 g/L/d and hydraulic retention time of 30 days yielded a productivity of 1.41 g/L/d. This is the first report of the production of mixed acids from the red algae G. amansii.

Anticancer peptides from bacteria

Cancer is a leading cause of death in the world. The rapid development of medicine and pharmacology allows to create new and effective anticancer drugs. Among modern anticancer drugs are bacterial proteins. Until now has been shown anticancer activity among others azurin and exotoxin A from Pseudomonas aeruginosa , Pep27anal2 from Streptococcus pneumoniae , diphtheria toxin from Corynebacterium diphtheriae , and recently discovered Entap from Enterococcus sp. The study presents the current data regarding the properties, action and anticancer activity of listed peptides. DOI: http://dx.doi.org/10.3329/bjp.v8i3.15704 Bangladesh Journal of Pharmacology Vol.8(3) 2013 343-348

Optimization of Marine bacteria Enterococcus sp. Biomass Growth by using Response Surface Methodology

Enterococcus sp . is one of the most important causes of substantial infections worldwide. It is a fastidious micro organism with fine nutritional and environmental requirements to cultivate, a characteristic that prevents the development of useful animal models to study the biology of the micro organism. This study was designed to determine optimal conditions for culture and growth of Enterococcus sp. The bacteria Enterococcus sp. was selected from isolates of marine water. Response surface methodology was employed to optimize a bacterial biomass growth. The five variables involved in the study of growth conditions were Yeast extract, beef extract, NaCl concentration, pH and Temperature. This is an estimate of the fraction of overall variation in the data accounted by the model, and thus the model is capable of explaining 99.96% of the variation in response

PCR–RFLP analysis of the diversity of phytate-degrading bacteria in the Tibetan Plateau

Phytases play a very important role in increasing phytate digestion and reducing phosphorus pollution in the environment, and phytate-degrading bacteria have a ubiquitous distribution in the environment. Due to its extremely harsh environment, the Tibetan Plateau breeds possibly abundant, extreme microorganisms. In this research, 67 phytate-degrading bacteria were isolated from different habitats in the Tibetan Plateau. Among all isolates, 40.3% were screened from farmland, 25.3% from wetland, 4.5% from saline-alkaline soil, 7.5% from hot springs, and 22.4% from lawns, which showed that the distribution of the phytate-degrading bacteria varied with habitats. By the PCR-RFLP method, 16 different species were identified and named, 4 of which are reported for the first time as phytate-degrading bacteria, that is, Uncultured Enterococcus sp. GYPB01, Bacillaceae bacterium strain GYPB05, Endophytic bacterium strain GYPB16, and Shigella dysenteria strain GYPB22. Through the assay of phytase activity of 16 strains, Klebsiella sp. strain GYPB15 displayed the highest capability of phytase production. Through analysis of the optimum pH, the optimum temperature, and the thermal stability of enzyme from 16 strains, some especial phytate-degrading bacteria were obtained. Our findings clearly indicate a good relation between the composition of the soils from the different environments in the Tibetan Plateau and populations of cultivable phytate-degrading bacteria. Moreover, extreme harsh soils are logically the best soils in which to find some strains of phytate-degrading bacteria for exploiting in the fields of biotechnology and industry.

Impact on bacterial community in midguts of the Asian corn borer larvae by transgenic Trichoderma strain overexpressing a heterologous chit42 gene with chitin-binding domain.

This paper is the first report of the impact on the bacterial community in the midgut of the Asian corn borer (Ostrinia furnacalis) by the chitinase from the transgenic Trichoderma strain. In this study, we detected a change of the bacterial community in the midgut of the fourth instar larvae by using a culture-independent method. Results suggested that Proteobacteria and Firmicutes were the most highly represented phyla, being present in all the midgut bacterial communities. The observed species richness was simple, ranging from four to five of all the 16S rRNA clone libraries. When using Trichoderma fermentation liquids as additives, the percentages of the dominant flora in the total bacterial community in larval midgut changed significantly. The community of the genus Ochrobactrum in the midgut decreased significantly when the larvae were fed with the fermentation liquids of the transgenic Trichoderma strain Mc4. However, the Enterococcus community increased and then occupied the vacated niche of the Ochrobactrum members. Furthermore, the Shannon–Wiener (H) and the Simpson (1-D) indexes of the larval midgut bacterial library treated by feeding fermentation liquids of the transgenic Trichoderma strain Mc4 was the lowest compared with the culture medium, fermentation liquids of the wild type strain T30, and the sterile artificial diet. The Enterococcus sp. strain was isolated and characterized from the healthy larvae midgut of the Asian corn borer. An infection study of the Asian corn borer larvae using Enterococcus sp. ACB-1 revealed that a correlation existed between the increased Enterococcus community in the larval midgut and larval mortality. These results demonstrated that the transgenic Trichoderma strain could affect the composition of the midgut bacterial community. The change of the midgut bacterial community might be viewed as one of the factors resulting in the increased mortality of the Asian corn borer larvae.

Oral administration of heparin or heparosan increases the Lactobacillus population in gut microbiota of rats

Heparin and heparosan have been confirmed to be effective blockers in inhibiting adhesion of pathogens in vitro. However, their effects on gut microbiota in vivo remain unknown. Here we have studied the effects of oral administration of heparin or heparosan on gut microbiota in rats by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results showed that the predominant bacterial communities in the feces of heparin- or heparosan-treated animals were different from those of the saline-treated animals, with increased Lactobacillus spp. and decreased Enterococcus sp. Different DGGE banding patterns were also observed for the subpopulations of Lactobacillus and Bacteroides groups. In conclusion, heparin or heparosan may be used as an effective gut microbiota modulator by increasing the subpopulation of Lactobacillus.

Growth Inhibition of Some Phytopathogenic Bacteria by Cell-Free Extracts from Enterococcus sp

Aims: To inhibit of bacterial growth of three important phyto-pathogenic bacteria: Erwinia carotovora, Clavibacter michiganensis sp. michiganensis and Xanthomonas axonopodis by cell-free extracts from submerged cultures of two strains of Enterococcus sp. was tested. Study Design: A complete randomized experimental design with factorial fix was used to evaluate the efficiency of growth inhibition against the phytopathogenic bacteria. Place and Duration of Study: Laboratory of Bioprocesses, Department of Food Science and Technology, School of Chemistry, Universidad Autonoma de Coahuila, Mexico, between December 2011 and July 2012. Methodology: Enterococci strains were isolated from goat milk, buttermilk and whey by typical microbiological procedures and primarily identified based on biochemical tests. Short Communication British Biotechnology Journal, 3(3): 359-366, 2013 360 Strains were subsequently activated in MRS broth and cells were separated by centrifugation and filtration. Cell-free extracts were tested against plant pathogenic bacteria to determine their growth inhibition potential. Results: Strains of Enterococcus MII-1 and MIV-2 were able to inhibit the growth of three pathogenic bacteria, demonstrating to be an attractive alternative for biological control assays. Conclusion: The cell-free extracts of Enterococcus spp. show inhibition potential to inhibit phytopathogenic bacteria that cause diseases in horticultural crops. Further studies are needed to completely evidence the high potential of use of cell-free extracts from Enterococcus MII-1 and MIV-2.

Bacteriological and Physicochemical Analyses of Borehole and Well Water Sources in Ijebu-Ode, Southwestern Nigeria

An investigative study was carried out to determine the bacteriological and physicochemical qualities of borehole and well water samples in Ijebu-Ode, Southwestern Nigeria. Ten water samples each of borehole and well water sources were collected within the geographical location. Physicochemical parameters were determined using standard methods. The total bacterial count was determined by pour plate technique and total coliform determined using 3-3-3 regimen. Identifications of isolates were done using standard methods. The colour and turbidity of water samples were within the normal range. Eight genera of bacteria which include Escherichia coli, Klebsiella sp, Salmonella sp, Shigella sp, Enterococcus sp, Proteus sp, Pseudomonas aeruginosa and Staphylococcus aureus were isolated from the water samples. Total bacterial count in borehole and well waters sampled ranged from zero to 2.5 x 10 2 cfu/ml and zero to 8.1 x 10 2 cfu/ml, respectively. The total coliform count of the borehole waters analyzed ranged from zero to 16 MPN index of coliform/100 ml while that of well waters ranged from 16 to 1100 MPN index of coliform/100 ml of the water samples. All borehole water samples had zero faecal coliform count while in well water samples, count ranged from zero to 4.1 x 10 2 cfu/ml. It was concluded that not all borehole waters are safe for consumption and well waters were of poorer bacteriological qualities indicative of health risk to the inhabitants of the geographical location.

Bacterial Flora of African Catfish (Clarias gariepinus ) Harvested From Ponds In Uyo South-South Nigeria

The bacteria flora of Clarias gariepinus was investigated using standard microbiological procedures. The total heterotrophic bacteria count of pond water, skin, gills and intestine of Clarias gariepinus ranged from 1.2 x 10 4 cfu/g in the gills to 2.16 x 10 6 cfu/cm 2 on the skin while the total coliform count ranged from nil in pond water to 3.5 x 10 4 cfu/g of the gills. The Salmonella - Shigella count was higher in the intestine of the catfish obtained from all the ponds under investigation while the total vibrio count was higher in pond water and intestine of catfish from all the ponds studied but was low in gills and skin. The bacteria flora included Streptococcus sp., Escherichia coli, Salmonella sp., Staphylococcus sp., Vibrio sp., Pseudomonas sp., Serratia sp., Klebsiella sp., Shigella sp. , Enterococcus sp. and Proteus sp. Enterococcus sp had the highest frequency of occurrence of 77% followed by Salmonella sp (75%) while Klebsiella sp had the least frequency of occurrence of 8% . The bacterial flora was composed of potential spoilage and pathogenic organisms that could constitute a public heath risk and economic loss. Catfish should be properly processed before consumption or preservation.

Attribute of Enterococcus sp. CFR 3003 to combat gamma-aminobutyric acid (GABA) deficiency

Attribute of Enterococcus sp. CFR 3003 to combat gamma-aminobutyric acid (GABA) deficiency

Genome Sequence of Enterococcus sp. Strain C1, an Azo Dye Decolorizer

Enterococcus sp. strain C1 is a facultative anaerobe which was coisolated with Citrobacter sp. strain A1 from a sewage oxidation pond. Strain C1 could degrade azo dyes very efficiently via azo reduction and desulfonation in a microaerophilic environment. Here the draft genome sequence of Enterococcus sp. C1 is reported.