Reference Bacteria Research Articles

FusionDB: assessing microbial diversity and environmental preferences via functional similarity networks.

Microbial functional diversification is driven by environmental factors, i.e. microorganisms inhabiting the same environmental niche tend to be more functionally similar than those from different environments. In some cases, even closely phylogenetically related microbes differ more across environments than across taxa. While microbial similarities are often reported in terms of taxonomic relationships, no existing databases directly link microbial functions to the environment. We previously developed a method for comparing microbial functional similarities on the basis of proteins translated from their sequenced genomes. Here, we describe fusionDB, a novel database that uses our functional data to represent 1374 taxonomically distinct bacteria annotated with available metadata: habitat/niche, preferred temperature, and oxygen use. Each microbe is encoded as a set of functions represented by its proteome and individual microbes are connected via common functions. Users can search fusionDB via combinations of organism names and metadata. Moreover, the web interface allows mapping new microbial genomes to the functional spectrum of reference bacteria, rendering interactive similarity networks that highlight shared functionality. fusionDB provides a fast means of comparing microbes, identifying potential horizontal gene transfer events, and highlighting key environment-specific functionality.

Effect of a static magnetic field on the microscopic characteristics of highly efficient oil-removing bacteria.

To better understand the microbial oil removal enhancement process by a magnetic field, the effect of a static magnetic field (SMF) on the microscopic characteristics of highly efficient biodegradation oil-removing bacteria was studied. The Acinetobacter sp. B11 strain with a 53.6% oil removal rate was selected as the reference bacteria. The changes in the microscopic characteristics of Acinetobacter sp. B11 such as the cell surface morphology, cell permeability and cell activity of the bacteria were investigated. The results showed that low-intensity magnetic fields (15-35 mT) improved the ability of Acinetobacter sp. B11 to remove oil by 11.9% at 25 mT compared with that of bacteria with no magnetic field. Without destroying the cell membrane, the low-intensity magnetic fields increased the cell membrane permeability and improved the activity of superoxide dismutase (SOD), which effectively enhanced the oil degradation performance of the bacteria.

Possible involvement of ROS generation in vorinostat pretreatment induced enhancement of the antibacterial activity of ciprofloxacin.

The mechanism underlying ciprofloxacin action involves interference with transcription and replication of bacterial DNA and, thus, the induction of double-strand breaks in DNA. It also involves elevated oxidative stress, which might contribute to bacterial cell death. Vorinostat was shown to induce oxidative DNA damage. The current work investigated a possible interactive effect of vorinostat on ciprofloxacin-induced cytotoxicity against a number of reference bacteria. Standard bacterial strains were Escherichia coli ATCC 35218, Staphylococcus aureus ATCC29213, Pseudomonas aeruginosa ATCC 9027, Staphylococcus epidermidis ATCC 12228, Acinetobacter baumannii ATCC 17978, Proteus mirabilis ATCC 12459, Klebsiella pneumoniae ATCC 13883, methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), and Streptococcus pneumoniae (ATCC 25923). The antibacterial activity of ciprofloxacin, with or without pretreatment of bacterial cells by vorinostat, was examined using the disc diffusion procedure and determination of the minimum inhibitory concentration (MIC) and zones of inhibition of bacterial growth. All tested bacterial strains showed sensitivity to ciprofloxacin. When pretreated with vorinostat, significantly larger zones of inhibition and smaller MIC values were observed in all bacterial strains compared to those treated with ciprofloxacin alone. In correlation, generation of reactive oxygen species (ROS) induced by the antibacterial action of ciprofloxacin was enhanced by treatment of bacterial cells with vorinostat. Results showed the possible agonistic properties of vorinostat when used together with ciprofloxacin. This could be related to the ability of these agents to enhance oxidative stress in bacterial cells.

Antibacterial efficacy of local plants and their contribution to public health in rural Ethiopia

BackgroundProper hand hygiene with soap and detergents prevents the transmission of many infectious diseases. However, commercial detergents are less likely to be accessible or affordable to poor people in remote rural areas. These people traditionally use some plant parts as a detergent even though their antibacterial activity has not been yet investigated. Therefore, this study aims to determine the antibacterial activities of some of the plants against bacteria isolated from humans.MethodsPlants selected for this study are Phytolacca dodecandra fruits, Rumex nepalensis leaves, Grewia ferruginea bark and leaves. The samples of these plants were collected from rural areas of Jimma town based on their ethno-botanical survey and information on their local use. Acetone was used as a solvent to extract the bioactive constituents of the plants. The antibacterial activities of the plants were evaluated against reference strains and bacteria isolated from humans using disc diffusion and macro dilution methods.ResultsThe plant extracts have shown varying antimicrobial activities against the bacterial species tested. Susceptibility testing shows zones of inhibition ranging from 8.0 ± 1.0 mm to 20.7 ± 5.5 mm. The MIC and MBC of the plants against the bacterial species tested were 3.13 and 12.5 mg/ml respectively. These variations are attributed to different concentrations of the bioactive constituents of the extracts like saponins, tannins, flavonoids and terpenoids.ConclusionThe studied plants can contribute to achieve better personal hygiene since they are effective against different bacterial agents and are freely available in rural areas.

Atividade bactericida de três desinfetantes sobre Staphylococcus aureus resistentes a meticilina (MRSA)

Justificativa e Objetivos: os Staphylococcus aureus resistentes a meticilina (MRSA) estão envolvidos em infecções nosocomiais (HA-MRSA), em infecções adquiridas na comunidade (CA-MRSA), nos animais de companhia e em animais para produção de alimentos (LA-MRSA). Na conduta para o controle da sua transmissão, a ação sobre os agentes causais presentes nas superfícies dos ambientes exige atenção, sendo decisiva a escolha de desinfetantes e anti-sépticos. O objetivo deste estudo foi avaliar a atividade bactericida, sobre 21 isolados MRSA e bactéria controle, dos compostos químicos hipoclorito de sódio (HS), iodofór (I) e quaternário de amônio (QAC - cloreto de cetil trimetilamônio), usados rotineiramente em ambientes hospitalares e igualmente nos de produção e saúde animal, bem como testar hipótese da possibilidade de resistência cruzada entre antibióticos e desinfetantes. Métodos: pelo teste de suspensão, usando densidade populacional inicial dos inóculos em 107UFC/mL, avaliou-se a atividade bactericida de quatro diluições sucessivas dos desinfetantes, nos tempos de contato de cinco, 15 e 30 minutos. Resultados: observou-se que os desinfetantes nas concentrações HS 25 ppm, I 12,5 ppm e QAC 125 ppm, aos cinco minutos de contato, foram suficientes para inativar a bactéria de referência S. aureus ATCC 6538 e todos os MRSA. Conclusão: controlados os fatores que interferem na eficácia dos desinfetantes, o hipoclorito de sódio, o iodofor e o quaternário de amônio são adequados para controlar os MRSA nas fontes de infecção, e que nos isolados resistentes ao antibiótico meticilina não foi observada relação de resistência com os estes compostos químicos.
 DESCRITORES: Staphylococcus aureus Resistente a Meticilina. Desinfetantes. Higiene.

Rubber elastomeric nanocomposites with antimicrobial properties

In this paper we show an elastomeric nanocomposite that exhibits antibacterial and antifungal activity. It comprises a rubber blend matrix and a nanofiller, which is a modified bentonite clay (Nanobent® ZR2). We have developed innovative technology for the nanofiller incorporation into the rubber matrix. This new approach was successfully implemented in pilot production at the Polish chemical manufacturer Spoiwo (Spoldzielnia Pracy Chemiczno–Wytworczej ‘Spoiwo’, Radom, Poland). Here we reveal that addition of the functionalised bentonite affects the mechanical and thermal behaviour of elastomers. For example, by adding 1–3% of bentonite nanoparticles we strongly enhanced elongation and tensile stress at break, whereas stiffness remained unchanged. We observed improvement of the thermal properties of the nanocomposites yielded and extension of the temperature usage range (from −29 to 311°C). As a proof of concept we present the antimicrobial effect of elastomeric nanocomposites verified on a wide range of both pathogenic and opportunistic reference bacteria strains, as well as reference strains of yeasts. The proposed method of hydrophilic nanofiller introduction into the rubber elastomer is economically viable and enables fabrication of elastomeric elements with high added value. Their significant antibacterial and antifungal activity makes them desirable in medicine, biomedical engineering, and the food industry.

The prophylactic effect of Acetobacter syzygii probiotic species against squamous cell carcinoma.

Background. Squamous cell carcinoma is a prevalent carcinoma of the oral cavity. Recently anti-proliferative effect of probiotics has been considered and assessed against different cancers. The aim of this study was to evaluate the cytotoxicity of Acetobacter syzygii strain supernatant on KB human oral cancer cell line and KDR human epithelial normal cell line. Methods. The cytotoxicity assessments were performed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) as well as through qualitative (4',6-diamidino-2-phenylindole staining) and quantitative (flow cytometry assessments using the BD Biosciences Annexin V-FITC Kit) evaluations of apoptosis. Results. A. syzygii secretions exhibited significant cytotoxicity against KB cancer cell lines similar to cisplatin (75.7% apoptosis) while the rate of apoptosis in KDR normal cells was only 9.36%. The prophylactic effects of Lactobacillus acidophilus (PTCC 1643), as a reference bacterium, was similar to A. syzygii, indicating beneficial effects of useful bacteria on prevention of oral diseases. Conclusion. The anticancer bioactivity of A. syzygii strain secretions depends on the induction of apoptosis in KB cancer cells. However, several investigations should be conducted to precisely determine effective compounds to be used as anticancer therapeutics in the future.

Bioactive Constituents, Radical Scavenging, and Antibacterial Properties of the Leaves and Stem Essential Oils from Peperomia pellucida (L.) Kunth.

Background:Peperomia pellucida is an annual herbaceous ethnomedicinal plant used in the treatment of a variety of communicable and noncommunicable diseases in the Amazon region.Objective:The study aimed at profiling the bioactive constituents of the leaves and stem essential oils (LEO and SEO) of P. pellucida, their in vitro antibacterial and radical scavenging properties as probable lead constituents in the management of oxidative stress and infectious diseases. Materials andMethods:The EOs were obtained from the leaves and stem P. pellucida using modified Clevenger apparatus and characterized by a high-resolution gas chromatography-mass spectrometry, while the radicals scavenging and antibacterial effects on four oxidants and six reference bacteria strains were examined by spectrophotometric and agar diffusion techniques, respectively.Results:The EOs exhibited strong antibacterial activities against six bacteria (Escherichia coli [180], Enterobacter cloacae, Mycobacterium smegmatis, Listeria ivanovii, Staphylococcus aureus, Streptococcus uberis, and Vibrio paraheamolyticus) strains. The SEO antibacterial activities were not significantly different (P < 0.05) from the LEO against most of the test bacteria with minimum inhibitory concentration ranging between 0.15 and 0.20 mg/mL for both EOs. The two oils were bactericidal at 0.20 mg/mL against S. aureus while the minimum bactericidal concentration (0.15 mg/mL) of LEO against L. ivanovii was lower than of SEO (0.20 mg/mL) after 24 h. The LEO IC50 value (1.67 mg/mL) revealed more radical scavenging activity than the SEO (2.83 mg/mL) and reference compounds against 2,2-diphenyl-1-picrylhydrazyl radical. The EOs also scavenged three other different radicals (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical, lipid peroxyl radical, and nitric oxide radical) in concentration-dependent manner.Conclusion:Our results suggest that apart from the indigenous uses of the plant extracts, the EO contains strong bioactive compounds with antibacterial and radicals scavenging properties and may be good alternative candidates in the search for novel potent antibiotics in this present era of increasing multidrug-resistant bacterial strains as well as effective antioxidants agents.SUMMARY Established gas chromatography-mass spectrometry technique was applied to quantitatively and qualitatively analyze the volatile constituents in Peperomia pellucida essential oil (EO)The Clinical and Laboratory Standards Institute (2014) guidelines were employed to evaluate the antibacterial effects of the EOsAmong the known prominent bioactive terpenoids, linalool 17.09%, limonene 14.25%, β-caryophyllene 12.52%, and linalyl acetate 10.15% were the main constituents of the EOs in this current studyThe leaf and stem EOs were bactericidal at a concentration below 0.23 mg/mL against three multidrug-resistant bacteria and significantly scavenged known free radicals reported to be associated with contagious and oxidative stress-related disorders. Abbreviations used: GC-MS: Gas chromatography-mass spectrometry, DPPH: 2,2-diphenyl-1-picrylhydrazyl, ABTS: 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, DMSO: Dimethyl sulfoxide, LP•: Lipid peroxide radical, NO•: Nitric oxide radical, LEO: Leaf essential oil, SEO: Stem essential oil, RC: Reference compound, TBARS: Thiobarbituric acid

Diagnosis of bacterial pathogens in the dialysate of peritoneal dialysis patients with peritonitis using surface-enhanced Raman spectroscopy

BackgroundBacterial peritonitis is the most common cause of peritoneal dialysis (PD) therapy drop-out. A quick and accurate diagnosis of the bacterial pathogen can reduce the PD drop-out rate. Surface-enhanced Raman spectroscopy (SERS) can rapidly identify bacteria using chips coated with nano-sized metal particles. MethodsKnown bacteria were loaded in the SERS-chips and illuminated with laser light to establish a reference Raman spectra library. Dialysate from PD peritonitis patients was concentrated by centrifuge and examined with the same SERS, and the resulting Raman spectra were compared with library spectra for bacteria identification. Principal component analysis was used for further confirmation. The same batches of dialysate were sent to routine culture as a reference bacteria identification method. The results of the 2 identification methods were compared. ResultsA total of 43 paired-samples were sent for study. There were 37 samples with bacteria identified but 6 were culture-negative by the reference method. 31 bacteria were identified in paired-samples by SERS, among which, 29 bacteria were exactly the same as those identified by the reference method. Bacteria not included in the reference library spectra cannot be identified. ConclusionsSERS techniques can rapidly identify bacterial pathogens in the dialysate of PD peritonitis patients.

The Immunopathogenic Potential of Arcobacter butzleri - Lessons from a Meta-Analysis of Murine Infection Studies.

BackgroundOnly limited information is available about the immunopathogenic properties of Arcobacter infection in vivo. Therefore, we performed a meta-analysis of published data in murine infection models to compare the pathogenic potential of Arcobacter butzleri with Campylobacter jejuni and commensal Escherichia coli as pathogenic and harmless reference bacteria, respectively.Methodology / Principal FindingsGnotobiotic IL-10-/- mice generated by broad-spectrum antibiotic compounds were perorally infected with A. butzleri (strains CCUG 30485 or C1), C. jejuni (strain 81-176) or a commensal intestinal E. coli strain. Either strain stably colonized the murine intestines upon infection. At day 6 postinfection (p.i.), C. jejuni infected mice only displayed severe clinical sequelae such as wasting bloody diarrhea. Gross disease was accompanied by increased numbers of colonic apoptotic cells and distinct immune cell populations including macrophages and monocytes, T and B cells as well as regulatory T cells upon pathogenic infection. Whereas A. butzleri and E. coli infected mice were clinically unaffected, respective colonic immune cell numbers increased in the former, but not in the latter, and more distinctly upon A. butzleri strain CCUG 30485 as compared to C1 strain infection. Both, A. butzleri and C. jejuni induced increased secretion of pro-inflammatory cytokines such as IFN-γ, TNF, IL-6 and MCP-1 in large, but also small intestines. Remarkably, even though viable bacteria did not translocate from the intestines to extra-intestinal compartments, systemic immune responses were induced in C. jejuni, but also A. butzleri infected mice as indicated by increased respective pro-inflammatory cytokine concentrations in serum samples at day 6 p.i.Conclusion / SignificanceA. butzleri induce less distinct pro-inflammatory sequelae as compared to C. jejuni, but more pronounced local and systemic immune responses than commensal E. coli in a strain-dependent manner. Hence, data point towards that A. butzleri is more than a commensal in vertebrate hosts.

Effect and mechanism of a High Gradient Magnetic Separation (HGMS) and Ultraviolet (UV) composite process on the inactivation of microbes in ballast water

The patented technology of a High Gradient Magnetic Separation (HGMS)-Ultraviolet (UV) composite process was used to treat ballast water. Staphylococcus aureus (S. aureus) was selected as the reference bacteria. After treatment by the HGMS-UV process, the concentration of S. aureus on the log 10 scale was lower than 2 at different flow rates, S. aureus suffered the most serious damage, and K+ leakage of the bacteria was 1.73mg/L higher than separate 60min UV irradiation (1.17mg/L) and HGMS (0.12mg/L) processes. These results demonstrated that the HGMS-UV composite process was an effective approach to treat ballast water. Further, the HGMS process had synergistic action on the subsequent UV irradiation process and accelerated cell membrane damage. Meanwhile, the results of superoxide dismutase (SOD) activities of bacteria and DNA band analyses indicated that the inactivation mechanisms were different for HGMS and UV irradiation.

Ciprofloxacin-Induced Antibacterial Activity Is Atteneuated by Pretreatment with Antioxidant Agents.

Ciprofloxacin works through interfering with replication and transcription of bacterial DNA, which leads to increased oxidative stress, and death of bacterial cells. Drugs with strong antioxidant such as tempol, melatonin and pentoxifylline might interfere with the antibacterial activity of ciprofloxacin. In the current study, the effect of these drugs on the cytotoxicity of ciprofloxacin was investigated against several reference bacteria. Standard bacterial strains included Escherichia coli ATCC 35218, Staphylococcus aureus ATCC29213, Pseudomonas aeruginosa ATCC 9027, Staphylococcus epidermidis ATCC 12228, Acinetobacter baumannii ATCC 17978, Proteus mirabilis ATCC 12459, Klebsiella pneumoniae ATCC 13883, methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), and Streptococcus pneumoniae (ATCC 25923). The antibacterial activity of ciprofloxacin with or without treatment of bacterial cells by tempol, melatonin or pentoxifylline was assessed using the disc diffusion method and by measuring the minimum inhibitory concentration (MIC) and zones of inhibition of bacterial growth. All of the tested bacterial strains were sensitive to ciprofloxacin. When treated with tempol, melatonin or pentoxifylline, all bacterial strains showed significantly smaller zones of inhibition and larger MIC values compared ciprofloxacin alone. In correlation, reactive oxygen species (ROS) generation induced by ciprofloxacin antibacterial action was diminished by treatment of bacterial cells with tempol, melatonin or pentoxifylline. In conclusion, results indicate the possible antagonistic properties for agents with antioxidant properties such as tempol, melatonin and pentoxifylline when they are used concurrently with flouroquinolones. This could be related to the ability of these agents to inhibit oxidative stress in bacterial cells.

Characterization of the in vitro production of N-acyl homoserine lactones by cultivable bacteria inhabiting the sponge Suberites domuncula

Sponges together with associated bacteria form complex holobionts governed by various relationships established between the partners. Molecules of communication may participate in the homeostasis of these biological associations. Bacteria produce N-acyl homoserine lactones to communicate. In the present study, we characterized 102 cultivable bacteria isolated from the sponge Suberites domuncula at the genus level and described their production of AHLs during 96 h of culture in a Marine Broth medium. The presence of AHLs was monitored using the Escherichia coli pSB406 reporter strain. Sixty-seven bacteria were AHLs positive. Among them, 46 were related to the Gammaproteobacteria, eight to the Alphaproteobacteria, seven to the Firmicutes and six to the Flavobacteria. The kinetic production of AHLs was determined and compared with a reference bacterium, Pseudomonas aeruginosa PAO1 (pDA224). We established three profiles of AHLs production with no definitive pattern related to an order, a family or a genus of bacteria.

Nanosized inorganic metal oxides as heterogeneous catalysts for the degradation of chemical warfare agents

Nanosized inorganic metal oxides, such as TiO2, ZnO, γ-Al2O3, are proposed as heterogeneous catalysts for the oxidative degradation of chemical warfare agents (CWA), particularly of organosulfur toxic agents, into oxidised products with reduced toxicity. The morphology, structural and textural properties of the catalysts were investigated. Furthermore, their catalytic properties were evaluated in the oxidative abatement of (2-chloroethyl)ethylsulfide, CEES, a simulant of sulfur mustard (blistering CWA). Their performance was also compared to a conventional decontamination powder and a commercial Nb2O5 sample. The metal oxides powders were then employed in the active oxidative decontamination of CEES from a cotton textile substrate, mimicking a real contamination occurrence. Remarkable results in terms of abatement and degradation into desired products were recorded, achieving good conversions and decontamination efficiency with Nb2O5, TiO2 and γ-Al2O3, under very mild conditions, with hydrogen peroxide (as aqueous solution or as urea-hydrogen peroxide adduct), at room temperature and ambient pressure. In the aim of a real on-field use, the potential environmental impact of these solids was also evaluated by bioluminescence toxicity tests on reference bacteria (Photobacterium leiognathi Sh1), showing a negligible negative impact for TiO2, γ-Al2O3, and Nb2O5. A major biotoxic effect was only found for ZnO.

Antimicrobial Activity Potential of Enterococcus spp. Isolated from Some Traditional Turkish Cheeses

Enterococci can produce enterocins which have antimicrobial activity against Gram-positive and also Gram-negative pathogenic, toxigenic and food-spoilage bacteria. The aim of this study was to determine the antimicrobial activity of Enterococcus spp. isolated from traditional Turkish cheeses such as Kashar, Manyas, Sepet, Kelle, Mihalic, Tulum. The isolates were tested against Listeria monocytogenes, Listeria innocua, Listeria ivanovii, Staphylococcus aureus and Enterococcus faecalis and also detected the presence of entA and entB genes of these isolates. Total 66 of enterococcal isolates were obtained from 34 of cheese samples and 25 of these isolates showed antimicrobial activity against tested reference bacteria by using agar spotting method. Also it was determined most of Enterococcus spp. carried enterocin encoding entA and entB genes. We concluded that these isolates or their enterocins may have a potential for food preservation, however they should be evaluated in terms of food safety.

In vitro antimicrobial activity of fermented spices and &lt;i&gt;Capsicum Frutescens&lt;/i&gt; against multi drug resistance clinical isolate and standard reference bacteria

Introduction : Food preservation is required to maintain for a long period of time. Traditional organic food preservative, “Datta” is spice mainly made up of Chili Peppers which frequently used in southern and western part of Ethiopia. can be consumed almost with every kind of foods and it is believed as appetizer and antimicrobial agent against food borne pathogen. This study aimed to assess in vitro antimicrobial activity of fermented condiment and Capsicum frutescens against multi drug resistance clinical isolate and standard reference bacteria. Method: samples collected from different level hotels and Capsicum frutescens (Chili peppers) were extractedin different solvents.Agar well diffusion assay was used to determine antimicrobial activity and minimum inhibitory concentration (MIC) and minimum bactericidal concentration was determined by tube dilution method. One way analysis of variant was used in comparison of the finding. Results: Extracted fermented condiment (Datta) sample and Chili Pepper showed antimicrobial activities against multidrug resistant clinical isolate and standard reference bacteria in well diffusion assay. extract showed MIC ranged from 25 mg/L to 66.7 mg/L and MBC ranged from 25 mg/L to 100 mg/L. The and Chili pepper extracts showed high antimicrobial activities against standard Staphylococcus aureus . The water based extract of sample were exhibited significantly low antimicrobial activities (P=0.000) as compared to the other extraction solvents. Conclusion: Water was weak extractor of active compounds having antimicrobial activities. Reference S. aureuswasmore susceptible organism while ATCC Salmonella enteritidis and clinical isolated multi-drug resistant E. coli less susceptible. The traditional use of fermented condiment for food preservation by the local people is supported by this study. Key words: Antimicrobial activity; Chili Pepper extract; Fermented condiment; Minimum bactericidal concentration; Minimum inhibition contraction Activite antimicrobienne en vitro d'epices fermentees et de fruits de capsicume pour la resistance aux medicaments isolate clinique et bacteries de reference standard Introduction: La conservation des aliments est necessaire pour maintenir pendant une longue periode de temps. Conservateur de nourriture organiqu et raditionnel, Datta est l'epice compose principalement de Chili Peppers qui frequemment utilize dans le sud et l'ouest de l'Ethiopie. peu tetre consomme presque avec toutes sortes d'aliments et on le croit comme un aperitif et un agent antimicrobien contre l'agent pathogene alimentaire. Cette etude visait a evaluer l'activite antimicrobienne in vitro du condiment fermente et Capsicum frutescens contre l'isolement clinique de resistance aux medicaments multiples et les bacteries de reference standard. Methode: Les echantillons de preleves dans des hotels de differents niveaux et Capsicum frutescens (Chili Peppers) ont ete extraits dans differents solvants. Un dosage de diffusion de puits a ete utilise pour determiner l'activite antimicrobienne et la concentration inhibitrice minimale (MIC) et la concentration bactericide minimale a ete determine par la methode de dilution du tube. Une analyse a sens unique de la variante a ete utilisee en comparaison de la decouverte. Resultats: L'echantillon extrait de condiments fermentes (Datta) et Chili Pepper ont montre des activites antimicrobiennes contre l'isolement Clinique resistant aux medicaments multiples et les bacteries de reference standard dans le dosage par diffusion de puits. L'extrait de a montreque le MIC variait de 25 mg / L a 66,7 mg / L et le MBC variait de 25 mg / L a 100 mg / L. Les extraits de poisson de et de Chili ont montre des activites antimicrobiennes elevees contre Staphylococcus aureus standard. L'extrait a base d'eau de l'echantillon de a montre des activites antimicrobiennes significativement faibles (P = 0,000) par rapport aux autres solvants d'extraction. Conclusion: L'eauetaitun extracteur faible de composes actifs ayant des activites antimicrobiennes. Reference S. aureus etait un organisme plus susceptible tandisque ATCC Salmonella enteritidis et E.coli . E. coli resistant aux medicaments multiples isoles etait moins susceptible. L'utilisation traditionnelle du condiment fermente pour la conservation des aliments par les populations locales est soutenue par cette etude. Mots cles: Activiteantimicrobienne; Extrait de poivre de piment; Condiment fermente; Concentration bactericide minimum; Contraction minimaled'inhibition

English

Lactic acid bacteria (LAB) arise in KaAŸar cheese, an artisanal pasta filata cheese produced in Turkey from raw milk without starter addition or pasteurized milk with starter culture. In this study, 13 samples of KaAŸar cheese that were produced from raw milk were used as reference materials. LAB were characterized by using phenotypic, API and Fourier transform infrared (FTIR) spectroscopy methods. One hundred and fifty-seven (157) strains were isolated from 13 cheese samples, and identification test was performed for 83 strains. At the end of the study, a total of 22 Lactococcus sp., 36 Enterecoccus sp. and 25 Lactobacillus sp. were determined in the isolated strains by phenotypic identification. After identification with FTIR spectroscopy and statistical analysis, expected results were not taken by FTIR spectroscopy due to higher correlation (> % 99) obtained with more than one reference culture. Fewer number of reference strains was a limitation of the analysis. Therefore, identification should be made with more reference bacteria in the FTIR analysis and should also be supported with molecular techniques. Key words: KaAŸar cheese, lactic acid bacteria, identification, Fourier Transform Infrared (FTIR).

Bacteria sensitivity index of UV disinfection of bacteria with shoulder effect

In research, design, and validation of UV disinfection systems of a given bacteria, shoulder effect makes prediction of fluence required difficult. This study theoretically analyzes the fluence required to inactivate any bacteria vs. E. coli as the reference bacteria, at the same Log I. Bacteria sensitivity index (BSI) is defined as the ratio between the inactivation rate constant ki of any bacteria for the linear portion of the dose response curve to that kir of E. coli. Among three sets of fluence requirement reported by the US EPA [4], Sommer et al. [5,20], and Chang et al. [6], the fluence required from the EPA is selected as the most suitable reference according to its predictive power as well as regulatory purpose. In the present study, shoulder broadness (SB), H0, is approximated with the intercept of the linear portion at the Log I=0. A universal equation which can be used to predict the fluence required of any bacteria with a shoulder: H=(0.914±0.055)*(BSI)E*(Log I)+H0. Furthermore, shoulder broadness index (SBI) is defined as the ratio between the fluence difference of any bacteria and the reference bacteria such as E. coli divided by the SB of E. coli. To validate the equation, an independent set of fluence data during UV disinfection of four different ARBs reported by McKinney and Pruden [8] was used. When the predicted fluence by using BSI of the ARBs is compared with the reported fluence at different Log I levels with less than 10% error with Log I up to 5.

Cave Cyanobacteria showing antibacterial activity

Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates). Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer) method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC) are given only for T. calypsus. Antibacterial activity was demonstrated against the Gram-positive clinical and reference bacteria, mostly pronounced in enterococci; no activity was observed against the Gram-negative bacteria. The above screening is the first record of antibacterial activity from lipid extracts of cave Cyanobacteria enhancing the importance of cave microbiota and the necessity for cave conservation. cave Cyanobacteria; Toxopsis calypsus; Phormidium melanochroun; antimicrobial susceptibility screening

Novel synthesis scheme and in vitro antimicrobial evaluation of a panel of (E)-2-aryl-1-cyano-1-nitroethenes

Drug resistance has become a major concern in the field of infection management, therefore searching for new antibacterial agents is getting more challenging. Our study presents an optimized and eco-friendly synthesis scheme for a panel of nitroalkenes bearing various functional groups in the aromatic moiety and bromine or cyano substituents in 1 position of nitrovinyl moiety. The presence of nitrolefine group outside the ring minimalizes genotoxic properties while conjugation of aryl group with nitrovinyl moiety increases stability of the compounds. Then our research focused on evaluation of biological properties of such obtained (E)-2-aryl-1-cyano-1-nitroethenes. As they exhibit strong bacteriostatic and bactericidal activities against reference bacteria and yeast species with no detectable cytotoxicity towards cultured human HepG2 and HaCaT cells, they could be promising candidates for the replacement of traditional nitrofurane-containing antibacterial drugs. Nevertheless, validation of the obtained data in an in vivo model and additional safety studies on mutagenicity are still required.