Gram-negative bacteria

Halitosis is an unpleasant condition that may be the origin of concern not only for a possible health condition but also for frequent psychological alterations which may lead to social and personal isolation. The most frequent sources of halitosis that exist in the oral cavity include bacterial reservoirs such as the dorsum of the tongue, saliva and periodontal pockets. Volatile sulphur compounds (VSCs) are the prominent elements of oral malodour. Genuine halitosis and pseudo-halitosis should be in the treatment realm of dental practitioners. Clinical Relevance: Halitosis can be a symptom of underlying systemic disease, therefore the exact diagnosis and its source (oral or non-oral) is important in the proper approach to its management.

Yersinia enterocolitica and Yersinia pseudotuberculosis have been identified as causative organisms of reactive arthritis in humans. We evaluated a Western blot assay which uses Yersinia outer membrane proteins as antigens for the detection of Yersinia antibodies as a replacement for the complement fixation (CF) assay. Clinical agreement, sensitivity, and specificity were determined by testing 19 positive and 21 negative serum samples by the CF assay, Western blot assay, and enzyme-linked immunosorbent assay (ELISA). The CF assay and ELISA were compared to the Western blot assay, which was the reference method used in this study. Sera with antibodies that could potentially cross-react with Yersinia were also tested by the Western blot assay. The agreement, sensitivity, and specificity of the CF method were 61%, 26%, and 95%, respectively; and those for the ELISA were 89%, 95%, and 82%, respectively. The prevalences of Yersinia antibodies in 50 healthy donors were 6% for immunoglobul...

Background: Parenteral medications are usually given out in multidose vials (MDVs) and can be used for a prolonged period for 1 or more patients. The risk of extrinsic contamination of MDVs and its consequences may be serious and may lead to an outbreak, especially in hospitals. Therefore, bacterial contamination of multiple-dose medication vials in Namazi Hospital, the major referral teaching hospital, in Shiraz, southwestern Iran, was evaluated. Methods: In a period of 4 months, all used MDVs in Namazi Hospital were collected by the infection control nurses. Information was recorded about the medication, labeling of vials, storing temperature, wards, and dates of opening. Remained contents of each vial were also tested for aerobic bacteria. Microbial contamination was confirmed by microbiologic methods. Results: Bacterial contamination was identified in 36 of 637 (5.6%) of vials, with no difference in contamination among different wards in the hospital or the medication type. Most commonly identified organisms were part of the normal commensally flora. Gram-positive bacteria (88.9%) were more significantly involved than gram-negative ones (11.1%), with the highest frequency for Staphylococcus epidermidis (44.4%) and the lowest for Actinomyces viscosus (2.8%). Conclusion: Although the clinical significance is not resolved at this point, infection control practices should be emphasized considering this potential source of nosocomial infection.

A total 67 strains were isolated from five different stations of Aksu River. Total aerobic bacteria number in the river was determined as 2 x 10 7 CFU/mL and fecal coliforms were determined >1100 MPN/100 mL. Strains of Enterobacteriaceae (66 isolates), representative of the human and animal commensal flora, and Pseudomonas sp. (1 isolate) were selected for antibiotic susceptibility testing. Among the isolates, 67,2% were Escherichia coli, 29,8% Klebsiella spp., 1,5% Citrobacter spp., and 1,5% Pseudomonas spp. Eleven antibiotics (Meropenem, Cefoxitin, Ceftazidime, Ceftriaxone, Imipenem, Sulbactam/Cefoperazone, Cefazoline, Cefotaxime, Aztreonam, Ampicillin/Sulbactam, Penicillin G) were used for determination of antibiotic resistance of isolates. Multiple antibiotic resistances were determined in 27 isolates (40%) and they were resistant to five or over antibiotics and 49,3% of the isolates were found to be β-lactamase producing.

The development of antibiotics and arthroscopic treatment have been two major turning points in the management of septic arthritis of the knee joint. We report a retrospective review of 78 patients managed in three surgery units and one rheumatology unit. Management practices varied between the units. Joint aspiration was proposed for all patients seen by rheumatologists. Certain surgeons proposed arthroscopy systematically at admission while others preferred a more selective approach. Arthroscopic wash-out was proposed as the first-line procedure for only 33 patients. All were given systemic antibiotics using a variety of protocols. The course under antibiotic treatment confirmed the potential gravity of septic arthritis of the knee joint since two patients died and 34 required surgery, half of which had more than one operation. The functional outcome at mean 19 months was rather poor. Only 65 knees were free of any implant and only 40 (62%) were pain free. Mean flexion was 116° and 11 patients (17%) had significant flexion contracture. Factors of poor prognosis were initially high sedimentation rate, advanced stage according to Gächter, presence of specific germs (meti-R S. aureus, Gram-negative bacilli), and failure of first-line treatment.

Multi-resistant gram-negative rods are important pathogens in intensive care units (ICU), cause high rates of mortality, and need infection control measures to avoid spread to another patients. This study was undertaken prospectively with all of the patients hospitalized at ...

Periodontitis is an infectious inflammatory disease that destroys the tooth-supporting tissues. It is caused by the formation of subgingival biofilms on the surface of the tooth. Characteristic bacteria associated with subgingival biofilms are the Gram-negative anaerobes Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, collectively known as the "red complex" species. Interepithelial junctions ensure the barrier integrity of the gingival epithelium. This may however be disrupted by the biofilm challenge. The aim of this in vitro study was to investigate the effect of subgingival biofilms on the expression of inter-epithelial junctions by gingival epithelia, and evaluate the relative role of the red complex. Multi-layered human gingival epithelial cultures were challenged with a 10-species in vitro subgingival biofilm model, or its variant without the red complex, for 3 h and 24 h. A low-density array microfluidic card platform was then used for analysing the expression of 62 genes encoding for tight junctions, gap junctions, adherens junctions, and desmosomes. Although there was a limited effect of the biofilms on the expression of tight, adherens and gap junctions, the expression of a number of desmosomal components was affected. In particular, Desmoglein-1 displayed a limited and transient up-regulation in response to the biofilm. In contrast, Desmocollin-2, Desmoplakin and Plakoglobin were down-regulated equally by both biofilm variants, after 24 h. In conclusion, this subgingival biofilm model may downregulate selected desmosomal junctions in the gingival epithelium, irrespective of the presence of the "red complex". In turn, this could compromise the structural integrity of the gingival tissue, favouring bacterial invasion and chronic infection.

The emergence of strains of multidrug-resistant Gram-negative bacteria mandates a search for new types of antimicrobial agents. Alyteserin-2a (ILGKLLSTAAGLLSNL.NH 2) is a cationic, a-helical peptide, first isolated from skin secretions of the midwife toad, Alytes obstetricans, which displays relatively weak antimicrobial and haemolytic activities. Increasing the cationicity of alyteserin-2a while maintaining amphipathicity by the substitution Gly 11 ! Lys enhanced the potency against both Gram-negative and Gram-positive bacteria by between fourfold and 16-fold but concomitantly increased cytotoxic activity against human erythrocytes by sixfold (mean concentration of peptide producing 50% cell death; LC 50 = 24 mM). Antimicrobial potency was increased further by the additional substitution Ser 7 !Lys, but the resulting analogue remained cytotoxic to erythrocytes (LC 50 = 38 mM). However, the peptide containing D-lysine at positions 7 and 11 showed high potency against a range of Gram-negative bacteria, including multidrugresistant strains of Acinetobacter baumannii and Stenotrophomonas maltophilia (minimum inhibitory concentration = 8 mM) but appreciably lower haemolytic activity (LC 50 = 185 mM) and cytotoxicity against A549 human alveolar basal epithelial cells (LC 50 = 65 mM). The analogue shows potential for treatment of nosocomial pulmonary infections caused by bacteria that have developed resistance to commonly used antibiotics.

The antimicrobial activities of Circium arvense extracts were evaluated against two human gram positive (Staphylococcus aureus, Micrococcus luteus) and four gram negative pathogen (Escherichia coli, pseudomonas aeruginosa, Enterobacter, Klebsiella pneumoniae). The Methanol extracts of Circium arvense were used to obtain various fractions (X1) n-hexane, (X2) chloroform, (X3) ethyl acetate and (X4) n-butanol. The agar well diffusion assay and agar dilution susceptibility testing were carried out to determine the zone of inhibitions and the minimum inhibitory concentration respectively. Antifungal activity was employed by agar well diffusion method. The Ampicilline, Ofloxacine and Itraconazole were used as standard agents. Almost all fractions exhibited more or less antimicrobial activity. The X2 (Chloroform) fraction was reported as highly active fraction with good antimicrobial activity MIC 0.312 mg/ml against staphylococcus areous. The MBC values of fraction X2 (chloroform) was 2 ti...

Clinical mercury resistant (Hg r ) Gram-negative bacteria carrying Gram-positive mercury reductase (merA)-like genes were characterized using DNA-DNA hybridization, PCR and sequencing. A PCR assay was developed which discriminated between the merA genes related to Staphylococcus and those related to the Bacillus/Streptococcus merA genes by the difference in size of the PCR product. DNA sequence analysis correlated with the PCR assay. The merA genes from Acinetobacter junii, Enterobacter cloacae and Escherichia coli were sequenced and shared 98-99% identical nucleotide (nt) and 99.6-100% amino acid identity with the Staphylococcus aureus MerA protein. A fourth merA gene, from Pantoeae agglomerans, was partially sequenced (60%) and had 99% identical nt and 100% amino acid identity with the Streptococcus oralis MerA protein. All the Hg r Gram-negative bacteria transferred their Gram-positive merA genes to a Gram-positive Enterococcus faecalis recipient with the resulting transconjugants expressing mercury resistance. These Gram-positive merA genes join Gram-positive tetracycline resistance and Gram-positive macrolide resistance genes in their association with mobile elements which are able to transfer and express in Gram-negative bacteria.

We compared the abilities of Biolog’s GN and ECO plates to distinguish among aerobic and heterotrophic bacterial communities in samples from six aquatic environments. The Biolog system is based on interpreting patterns of sole-carbon substrate utilization indicated by color development in a 96-well microtiter plate. Whether of fresh or saltwater origin, bacterial communities utilized >95% of substrates in both types of plates. Samples from any one environment exhibited similar time courses of average well color development (AWCD) in both GN and ECO plates. Principal component analysis was performed on data sets resulting from combinations of algorithms (AWCD and curve-integration methods) and levels of color development (end-point and set-point approaches). In all cases, the two types of plates demonstrated an equal capacity to discriminate among the heterotrophic expressions of the six microbial communities. Substantial deviation from an anticipated 1:1 correspondence occurred when color development of 25 substrates common to both types of plates was compared. The discrepancies likely are related to the different formulations of low-nutrient media in GN and ECO plates.

Molecular mechanisms of multidrug resistance in Vibrio cholerae belonging to non-O1, non-O139 serogroups isolated during 1997 to 1998 in Calcutta, India, were investigated. Out of the 94 strains examined, 22 strains were found to have class I integrons. The gene cassettes identified were dfrA1, dfrA15, dfrA5, and dfrA12 for trimethoprim; aac(6)-Ib for amikacin and tobramycin; aadA1 and aadA2 for streptomycin and spectinomycin; and ereA2 for erythromycin resistance. To our knowledge, this is the first report of the presence of dfrA5, dfrA12, aac(6)-Ib, and ereA2 cassettes in class I integrons of V. cholerae. Forty-three of 94 strains also had plasmids, and out of these, 14 contained both class I integrons and plasmids. Pulsed-field gel electrophoresis followed by Southern hybridization revealed that in the 14 plasmid-bearing strains, class I integrons resided either on chromosomes, on plasmids, or on both. Our results indicated that besides class I integrons and plasmids, a conjugative transposon element, SXT, possibly contributed to the multiple antibiotic resistance.

GTPases of the p47 family involved in intracellular pathogen control. We tested TNF-α α α α and p47-GTPase induction in macrophages using classical LPSs [lipid As with glucosamine backbones, ester-and amidelinked C14:0(3-OH) and C12 to C16 in acyloxyacyl groups] of wild type and mutant Escherichia coli and Yersinia species and non-classical LPSs [lipid As with diaminoglucose, ester-linked 3-OH-fatty acids and C28:0(27-OH) and C23:0(29-OH) in acyloxyacyl groups] of plant endosymbionts ( Rhizobium ), intracellular pathogens ( Brucella and Legionella ) and phylogenetically related opportunistic bacteria ( Ochrobactrum ). Classical but not non-classical LPSs efficiently induced TNF-α α α α , IIGP and IGTP p47-GTPase expression. Remarkably, the acyloxyacyl groups in classical LPSs necessary to efficiently induce TNF-α α α α

Helaeomyia petrolei (oil fly) larvae inhabit the asphalt seeps of Rancho La Brea in Los Angeles, Calif. The culturable microbial gut contents of larvae collected from the viscous oil were recently examined, and the majority (9 of 14) of the strains were identified as Providencia spp. Subsequently, 12 of the bacterial strains isolated were tested for their resistance or sensitivity to 23 commonly used antibiotics. All nine strains classified as Providencia rettgeri exhibited dramatic resistance to tetracycline, vancomycin, bacitracin, erythromycin, novobiocin, polymyxin, colistin, and nitrofurantoin. Eight of nine Providencia strains showed resistance to spectinomycin, six of nine showed resistance to chloramphenicol, and five of nine showed resistance to neomycin. All 12 isolates were sensitive to nalidixic acid, streptomycin, norfloxacin, aztreonam, cipericillin, pipericillin, and cefotaxime, and all but OF008 (Morganella morganii) were sensitive to ampicillin and cefoxitin. The oil fly bacteria were not resistant to multiple antibiotics due to an elevated mutation rate. For each bacterium, the number of resistant mutants per 10 8 cells was determined separately on rifampin, nalidixic acid, and spectinomycin. In each case, the average frequencies of resistant colonies were at least 50-fold lower than those established for known mutator strain ECOR 48. In addition, the oil fly bacteria do not appear to excrete antimicrobial agents. When tested, none of the oil fly bacteria produced detectable zones of inhibition on Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, or Candida albicans cultures. Furthermore, the resistance properties of oil fly bacteria extended to organic solvents as well as antibiotics. When pre-exposed to 20 g of tetracycline per ml, seven of nine oil fly bacteria tolerated overlays of 100% cyclohexane, six of nine tolerated 10% xylene, benzene, or toluene (10:90 in cyclohexane), and three of nine (OF007, OF010, and OF011) tolerated overlays of 50% xylene-50% cyclohexane. The observed correlation between antibiotic resistance and organic solvent tolerance is likely explained by an active efflux pump that is maintained in oil fly bacteria by the constant selective pressure of La Brea's solvent-rich environment. We suggest that the oil fly bacteria and their genes for solvent tolerance may provide a microbial reservoir of antibiotic resistance genes.

This study evaluates the association between dental procedures and bacteremia in dogs, including a comparison of bacteria isolated from plaque and blood, severity of the bacteremia versus the severity of dental disease, and the longevity of bacteremia. Study Design-Bacteria cultured from the blood over time were compared with those isolated from the plaque and crevicular fluid and in relation to severity of dental disease. Animals or Sample Population-Twenty adult greyhounds. Methods-Blood samples were collected for culture before induction of general anesthesia, immediately after intubation, 20 minutes after initiation of the dental procedure, and at 10minute intervals until 10 minutes after the dental procedure was completed. Samples of plaque were taken for microbiological culture. Results-Sixty to ninety percent of the bacterial genera isolated from the plaque were present in the blood. Dogs classified according to severity of dental disease showed no difference in the total number of different species or number of different Gram-negative, Gram-positive, or anaerobic bacteria isolated from plaque or blood (P < .05). Bacteremia was present in all of the dogs studied, within 40 minutes from the initiation of the dental procedure, regardless of the severity of oral disease. Conclusions-Gram-negative, Gram-positive, and anaerobic bacteria are present in blood during dental procedures; the bacteremia can persist beyond the dental procedure, and is not associated with the severity of dental disease. Clinical Relevance-The nature and extent of bacteremia occuring during routine dental procedures is important in understanding a potential risk to dogs.

Although several strains ofB. subtiliswith antifungal activity have been isolated worldwide, to date there are no published reports regarding the isolation of a nativeB. subtilisstrain from strawberry plants in Mexico. A native bacterium (Bacillus subtilis21) demonstratedin vitroantagonistic activity against different plant pathogenic fungi. Under greenhouse conditions, it was shown that plants infected withRhizoctonia solaniandFusarium verticillioidesand treated withB. subtilis21 produced augment in the number of leaves per plant and an increment in the length of healthy leaves in comparison with untreated plants. In addition,B. subtilis21 showed activity against pathogenic bacteria. Secreted proteins byB. subtilis21 were studied, detecting the presence of proteases and bacteriocin-like inhibitor substances that could be implicated in its antagonistic activity. Chitinases and zwittermicin production could not be detected. Then,B. subtilis21 could potentially be used to control phyt...

The objective of this study was to compare aspiration pneumonia (AP)-associated microflora, calculus, and oral hygiene/care seeking behaviors in special health care needs children (SC) with gastrostomy (GT) and without. Methods: Twenty-seven GT SC, ages 3 to 12 years old and matched for age and gender with 27 non-GT SC, were examined by 2 trained investigators who recorded calculus and gingival inflammation and reconciled differences. Plaque was obtained using preweighed dry paper points and saliva sampled using sterile pipettes and cultured using standard bioassay procedures in a hospital laboratory. Parent/caretakers completed a medical and oral health questionnaire. Results: No significant differences were noted for age, gender, weight, primary diagnosis, vomiting, constipation, or swallowing disorder, but GT children received 4 medications vs 1 for non-GT and were significantly more likely to have had AP, need special feeding, and drool (P≤.05). Oral health measures were not significantly different for brushing frequency, dentifrice use, brushing problems, frequency of dental care, or gingival inflammation, but GT patients had significantly more plaque and calculus. GT patients had significantly more Haemophilus influenzae, with trends toward more gram negative enteric rods, pseudomonas, and Streptococcus pneumoniae and higher concentrations in several GT-patients and little or none in non-GT patients. GT SC had significantly less β-streptococci than non-GT patients (P≤.05). Conclusions: GT SC had significantly more of 1 AP-associated organism than non-GT SC and significantly more calculus and plaque, in spite of similar care seeking and hygiene behaviors. (Pediatr Dent. 2004;26:283-288)

The aim of this work was to isolate a lectin from Myracrodruon urundeuva heartwood and to evaluate its antimicrobial activity against bacteria and fungi that attack plants, including woods. The lectin was isolated from heartwood through affinity chromatography on a chitin column monitored by hemagglutination assay. The lectin inhibited Gram-negative and Gram-positive bacteria and was more effective than antifungal Cercobin in growth inhibition of phytopathogenic fungi. The detected antimicrobial activity reveals the possible role of the lectin in the resistance of M. urundeuva heartwood against deteriorative biological agents. The M. urundeuva lectin is the first bioactive peptide found in heartwood, probably stored as a chemical protection against biodegradation.

A total of 103 isolates of basidiomycetes, representing 84 species from different Brazilian ecosystems, were evaluated for their antifungal and antibacterial activity in a panel of pathogenic and non-pathogenic microorganisms. Tissue plugs of the fruiting bodies were cultivated in liquid media and the whole culture extracted with ethyl acetate. Crude extracts from Agaricus cf. nigrecentulus, Agrocybe perfecta, Climacodon pulcherrimus, Gloeoporus thelephoroides, Hexagonia hydnoides, Irpex lacteus, Leucoagaricus cf. cinereus, Marasmius cf. bellus, Marasmius sp., Nothopanus hygrophanus, Oudemansiella canarii, Pycnoporus sanguineus, Phellinus sp., and Tyromyces duracinus presented significant activity against one or more of the target microorganisms. Eight isolates were active only against bacteria while three inhibited exclusively the growth of fungi. Two extracts presented wide antimicrobial spectrum and were active against both fungi and bacteria. Differences in the bioactivity of extracts obtained from isolates from the same species were observed.

The intestinal mucosal surface is colonised by the comensal microflora that attains very high numbers of bacterial cells in the distal intestine, more specifically in the colon. At the same time these extensive areas are the interface with the external environment, through which most pathogens initiate infectious processes in mammals. Intestinal mechanisms of defense need to discriminate accurately between comensal, symbiotic microflora, and exogenous pathogens. Today we do not fully understand the essence of the mechanism of discrimination but, probably, innate as well as adaptive immune responses participate in this process. We have explored , in in vitro models, the capacity of mucosal immunocompetent cells to discriminate amongst signals delivered by different types of bacteria. We have found at least two different patterns of innate response to gram-negative and gram-positive bacteria, and within this last group big differences are observed between species. We have only worked with non-pathogenic bacteria in what may represent the modulation of the physiological host status. The understanding of these modulatory functions could render a unique possibility for the use of food-borne bacteria to prevent or correct intestinal problems associated with food allergy, inflammatory bowel disease, and autoimmunity.

Propolis or bee-glue is a sticky substance collected in the hives by the honeybee (Apis mellifica L., Apidae) from various tree sources. In the northern hemisphere (Europe, North and South America and western Asia), the tree sources are: Populus spp., Betula spp., Ul-423 Acta Pharm. 55 (2005) 423-430

A collaborative study involving seven laboratories was undertaken to evaluate the reproducibility and the reliability of the broth disk elution test against anaerobic bacteria by comparing with the reference agar dilution method. A two breakpoint broth test was also evaluated. Assays were performed using the same testing conditions (i.e. medium, temperature, atmosphere and incubation time). One hundred Gram-negative and Gram-positive clinical isolates were initially studied. Overall agreement of 98.5% and 97.5%, were found for disk elution and the two breakpoint tests, respectively. In order to assess the reliability of the disk elution test, two different lots (LOT1 and LOT2) of disks of piperacillin and clindamycin were selected, to obtain two final concentrations after dilution (10 and 60 mg/mL; 1 and 4 mg/mL, respectively). Two hundred and eighty assays were performed against one strain of both Bacteroides fragilis(piperacillin MIC, 8.0 mg/mL; clindamycin MIC, &amp;lt;0.5 mg/mL) and Bacteroides thetaiotaomicron(piperacillin MIC, 16.0 mg/mL; clindamycin MIC, &amp;lt;0.5 mg/mL). With LOT 1, considering both species and both antibiotics, the agreement among six laboratories ranged from 85% to 100% (P &amp;gt; 0.05) with the higher concentration. Overall agreement among all laboratories was 91%. No optimal agreement (&amp;gt;90%) for clindamycin-Bacteroides thetaiotaomicron using the LOT1 (77%) was found. Since this finding was not observed with LOT2 (100% agreement), discrepancies were attributed to variation between lots. Overall agreement with LOT2 was 100% for all centres. The present study indicates that the broth disk elution method proved to be a reliable and suitable alternative for routine susceptibility testing for anaerobic bacteria, as a resistance screening method for clinical purposes.

A nonmotile, nonspore-forming, Gram-negative, aerobic, small rod-shaped bacterium, isolated from soil, was identified as Chryseobacterium gleum on the basis of 16S rRNA gene sequence analysis. It was observed to grow luxuriously at pH 9 and tolerate highly alkaline environment up to pH 12. Orange red color was a peculiar character of these cells which on purification obtained 60-80 mg/l and found to be sphingosine type of sulfonolipid "sulfobacin A" on the basis of infrared, nuclear magnetic resonance, and mass spectral data. Inhibition of sulfobacin A synthesis by incorporation of L-cycloserine in culture growth medium suggested presence of serine palmitoyl transferase which is one of the important enzymes involved in its biosynthesis. Sulfobacin A from C. gleum LMG P-22264 exhibited cytotoxicity against four cell lines tested. Maximum activity against human mammary adenocarcinoma cells was indicative of its potential as an anticancer agent.

Solvent extracts from the carnivorous plant Dionaea muscipula (Venus flytrap) were prepared using eight different organic solvents, and examined for antibacterial activity against food-related pathogenic and putrefactive bacteria. All solvent extracts showed higher antibacterial activity against gram positive bacteria than against gram negative bacteria. The TLC-bioautography analysis of the extracts revealed that a yellow spot was detected at Rf value of 0.85, which showed strong antibacterial activity. The UV, MS, and NMR analyses revealed that the antibacterial compound was plumbagin.

Steroidal [oxazolo(4,5-b)quinoxaline-2-yl-hydrazone] derivative (7a-9a) (7b-9b) were prepared by the multi-step reactions of steroid. It is prepared via the reaction of steroidal semicarbazones with 2,3-dichloroquinoxaline at 80°C in ethanol. The structures of the compounds were evident by IR, 1H NMR and mass spectrometry and their purities were confirmed by elemental analyses. The antibacterial activity of these compounds was evaluated by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria and then the minimum inhibitory concentration (MIC) of compounds was determined. The results showed that compounds (7a, 7b, 8a, 8b) are better antibacterial agent as compared with the standard drug amoxicillin.

Characterization of psychrotrophic lactic acid bacteria (LAB) and Brochothrix thermosphacta communities is needed to understand the microbial ecology of spoilage of modified atmosphere-packed (MAP) meats. To overcome the limitations of the currently used methods for the characterization of psychrotrophic bacterial communities in meat, we developed a culture-independent, 16S rRNA gene-targeted terminal restriction fragment length polymorphism (T-RFLP) method. An identification library

Bacterial infections are a global health concern with high levels of mortality and morbidity associated. The resistance of pathogens to drugs is one leading cause of this problem, being common the administration of multiple drugs to improve the therapeutic effects. This review critically explores diverse aspects involved in the treatment of bacterial infections through multi-drug therapies, from a mathematical and within-host perspectives. Five recent models were selected and are reviewed. These models fall into the following question: which drugs to select, the respective dose, the administration period to effectively eradicate the infection in the shortest period of time and with reduced side effects? In this analysis, three groups of variables were considered: pharmacokinetics, pharmacodynamics and disturbance variables. To date, there is no model that fully answers to this issue for a living organism and it is questionable whether this would be possible for any case of infection.

Acacia nilotica subsp. kraussiana was reported in African traditional medicine for the treatment of various ailments. Isolation of an active compound in this study from the bark extract may lead to the validation of its efficiency as a traditional crude drug.This study aimed to isolate active compound(s) from an ethyl acetate bark extract of Acacia nilotica subsp. kraussiana and to investigate some of its biological activity.The isolation process was carried out using bioassay-guided fractionation. The isolated compound was tested for antibacterial activity using the micro-dilution assay; anti-inflammatory activity using the COX-1 and COX-2 assays and investigated for inhibitory effect against acetylcholinesterase using the microplate assay.A new bioactive compound was isolated and identified as a cassane diterpene, niloticane. Niloticane showed antibacterial activity against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus with MIC values of 4 and 8 μg/mL, respectively. With Gram-negative bacteria, niloticane showed weak activity. MIC values obtained were 16 and 33 μg/mL against Klebsiella pneumonia and Escherichia coli, respectively. In the cyclooxygenase test, niloticane possessed activity with IC50 values of 28 and 210 μM against COX-1 and COX-2, respectively. IC50 values observed with indomethacin (positive control) were 3.6 μM for COX-1 and 189 μM for COX-2. In the acetylcholinesterase test, niloticane showed anti-cholinesterase activity with an IC50 value of 4 μM. IC50 values obtained by the galanthamine (positive control) was 2.0 μM.The results obtained support the traditional uses of the bark of Acacia nilotica subsp. kraussiana in African traditional medicine for the treatment of some ailments that relate to microbial diseases, inflammation and central nervous system disorders.

Eighty isolates of Riemerella anatipestifer representing 71 outbreaks of riemerellosis in Thailand between 1994 and 1999 were serotyped using the gel diffusion precipitin test. Based on the precipitation patterns, 25 serological profiles containing one to three antigenic determinants were recognized. Heatstable antigens of the organism reacted with antisera raised against 16 known serotypes and an untypable strain 698/ 95. The most prevalent serotype appeared to be serotype 7, followed by serotypes 5, 10, 21 and 1. Further study demonstrated that the untypable strain probably represents a new serotype. Analysis of the polymerase chain reaction-amplified rrs genes for restriction fragment length polymorphisms verified the inclusion of strain 698/ 95 within the species R. anatipestifer and supported earlier work excluding strain 670/ 89, which had originally been designated the reference strain of serotype 20. Therefore, it is suggested that the strain 698/ 95 could be adopted as a replacement for the reference strain of serotype 20. Attention should be paid to strains with multiple antigenic factors as they may be useful for the preparation of vaccines.

Chlorhexidine gluconate is a relatively commonly used chemotherapeutic in the treatment of periodontitis (P), exhibiting antimicrobial capabilities against Gram-negative and Gram-positive bacteria, and fungi. This compound is a component of various preparations for topical use in the form of solutions for mouthrinsing or peri-irrigation, gels, varnishes, chips and even chewing gums. The aim of the study was the clinical evaluation of periodontium after treatment with one of the drugs containing chlorhexidine gluconate (Corsodyl) as compared to professional tooth cleaning in patients with chronic periodontitis. MATERAL AND METHODS: Forty subjects enrolled in the study were divided into four groups, 10 in each group, according to the mode of treatment (Corsodyl rinse, Corsodyl gel, Corsodyl gel + surgical dressing, scaling). The greatest differences between baseline and follow-up examinations were observed in the group where surgical dressing was applied in addition to Corsodyl gel an...

The aerobic degradation of cholesterol, testosterone, androsterone, progesterone, and further steroid compounds as sole carbon source has been observed in the newly isolated bacterial Gram-positive strain Chol-4. The 16S rRNA gene sequence shares the greatest similarity with members of the genus Rhodococcus, with the closest shared nucleotide identities of 98-99% with Rhodococcus ruber (DSM 43338 T ) and Rhodococcus aetherivorans (DSM 44752 T ). Phylogenetic analysis of Rhodococcus 16S rRNA gene sequences consistently places strain Chol-4 in a clade shared with those both type strains within the Rhodococcus rhodochrous subclade. The results of DNA-DNA hybridization against its two phylogenetically closest neighbors as well as the results of morphological, physiological, and biochemical tests allowed genotypic and phenotypic differentiation of strain Chol-4 from Rhodococcus ruber (DSM 43338 T ) on the species level and from the other validly described Rhodococcus species on the genus level. Strain Chol-4 therefore merits recognition as a novel strain of the species Rhodococcus ruber and demonstrates for the first time the capability of this species to utilize a great variety of steroid compounds as growth substrates never shown for other species of this genus so far. The genome of strain Chol-4 harbors at least one gene cluster that may be responsible for the degradation of steroid compounds. This gene cluster was identified in a cloned 5458 bp BamHI-EcoRV DNA fragment and compared to similar genes from other Gram-positive and Gram-negative bacteria described so far.

The pathogenesis of sepsis begins with the proliferation of microorganisms at a site of infection, followed by invasion of the bloodstream and other organs. Gram-negative bacteria account for a large part of sepsis cases. The structural component of Gram-negative bacteria, endotoxin or lipopolysaccharide (LPS), induces the synthesis and release of endogenous mediators of sepsis. A growing number of investigations of the molecular mechanisms occurring in sepsis, point to endotoxin as a central mediator leading to multi-organ failure and death. In numerous clinical trials, attempts to target molecules downstream of endotoxin have been made, but have not been associated with improved survival. We describe an affinity-based system for the selective removal of endotoxin from plasma. The small-scale device, a 1.5 ml cartridge, contains beads that bind endotoxin with high specificity and efficiency. In addition, evidence is presented that this device does not affect plasma hemostasis, nor does it activate the complement system. Taken together, these results represent a proof of principle for endotoxin removal from plasma, which may be of clinical value to treat sepsis by extracorporeal circulation of the blood through a scaled-up version of this endotoxin-removing device.

The nano-sized coupled oxides ZnO/SnO 2 thin films in a molar ratio of 2:1 (Z2S), 1:1 (ZS) and 1:2 (ZS2) were prepared using sol-gel dip coating method and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectroscopy. Escherichia coli (E. coli, ATCC 25922) was selected as a model for the Gram-negative bacteria to evaluate antibacterial property of composite samples compared with single ZnO (Z) and single SnO 2 (S) films. The antibacterial activity has been studied applying the so-called antibacterial drop test under UV illumination. The bactericidal activity was estimated by relative number of bacteria survived calculated from the number of viable cells which form colonies on the nutrient agar plates. The influence of the SnO 2-ZnO nanocomposite composition on the structural features and on the antibacterial properties of the thin films are reported and discussed. It is found that all coatings exhibited a high antibacterial activity. The coupled oxide photocatalyst Z2S has better photocatalytic activity to bacteria inactivation than ZS, ZS2, Z and S films. Furthermore, nanostructured films were active even in the absence of irradiation.

An eco-friendly microbial method for synthesis of silver colloid solution with antimicrobial activity is developed using a fungal strain of Peni-cillium purpurogenum NPMF. It is observed that increase in concentration of AgNO3 increases the formation of silver nanoparticle. At ...

Ethnopharmacological relevance: Buddleja salviifolia leaves are used for the treatment of eye infections and neurodegenerative conditions by various tribes in South Africa. Aim of study: This study was designed to isolate the phenolic constituents from the leaf extracts of Buddleja salviifolia and evaluate their antimicrobial and acetylcholinesterase (AChE) activities. Material and methods: Three phenolic compounds were isolated from the ethyl acetate fraction of a 20% aqueous methanol leaf extract of Buddleja salviifolia using Sephadex LH-20 and silica gel columns. Structure elucidation of the isolated compounds was carried out using spectroscopic techniques: mass spectrometry (ESI-TOF-MS) and NMR (1D and 2D). The extracts and isolated compounds were evaluated for antimicrobial and acetylcholinesterase activities using the microdilution technique. The bacteria used for the antimicrobial assays were Gram-positive Bacillus subtilis and Staphylococcus aureus and Gramnegative Escherichia coli and Klebsiella pneumoniae. Results: The isolated compounds were characterized as: 4′-hydroxyphenyl ethyl vanillate (1) a new natural product, acteoside (2) and quercetin (3). The crude extract, fractions and the isolated compounds from the leaves of the plant exhibited a broad spectrum of antibacterial activity. The EtOAc fraction exhibited good activity against Bacillus subtilis and Staphylococcus aureus with MIC values ranging from 780.0 to 390.0 mg/mL. Isolated compound 2 exhibited good activity against Staphylococcus aureus with an MIC value of 62.5 mg/mL. The hexane and DCM fractions of leaves showed the best activity against Candida albicans with MIC and MFC values of 390.0 mg/mL. In the AChE inhibitory test, among the tested extracts, the hexane fraction was the most potent with an IC 50 value of 107.4 mg/mL, whereas for the isolated compounds, it was compound (3) (quercetin) with an IC 50 value of 66.8 mg/mL. Conclusions: Activities demonstrated by the extracts and isolated compounds support the ethnopharmacological use of Buddleja salviifolia against eye infections and neurodegenerative diseases.

A series of novel 3-tert-butyl-7-(aryloxymethyl)-4H-[1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-4-ones (5a e5n) were synthesized by refluxing 3,3-dimethyl-2-oxobutanoic acid (trimethyl pyruvic acid) (1) and thiocarbohydrazide (2) in ethanol as solvent for 12 h, to yield 3-mercapto-4-amino-6-tert-butyl-1,2,4triazine-5(4H)-one (3) (Scheme 1), then the compound (3) was condensed with different substituted aryloxyacetic acids (4) in POCl 3 at 90 C for 8 h (Scheme 2). The structures of the newly synthesized compounds were confirmed by IR, 1 H NMR, 13 C NMR, elemental analyses and mass spectroscopic studies. Few of the synthesized compounds exhibited moderate mosquito-larvicidal and antibacterial activities. Among the novel derivatives, the compound (5f) showed relatively high larvicidal activity against a malaria vector. Compounds (5i) and (5m) exhibited a broad spectrum antibacterial activity against Gram positive and Gram negative species and hence they may be considered as drug candidates for bacterial pathogens.

Critical illness polyneuromypathy has not previously been reported as a complication of diabetic coma. We describe a patient with hyperosmolar non-ketotic coma (HONK) complicating gram-negative sepsis in whom persistent coma and profound tetraplegia caused considerable concern. Although, initially, it was feared that the patient had suffered a central neurological complication such as stroke or cerebral oedema, a diagnosis of critical illness motor syndrome (CIMS) was subsequently confirmed neurophysiologically. Profound limb weakness associated with HONK is not necessarily due to a catastrophic cerebral event, rather it may be a result of CIMS, which has an excellent prognosis for full neurological recovery.

To evaluate enteropathogens and other factors associated with severe disease in children with diarrhea, 381 children !5 years of age with diarrhea and moderate to severe dehydration (in-patients) and 381 age-, sex-, and date-of-visit-matched children with mild diarrhea (outpatients) presenting to a hospital in Peru, were studied. Rotavirus was detected in 52% of the in-patients and 35% of the out-patients (odds ratio , 95% confidence interval [95% [OR] ϭ 2.3 ); 95% of the rotaviruses among in-patients were of serotypes G1-G4. The risk CI] ϭ 1.6-3.2 of severe diarrhea was particularly great in children who were not exclusively breast-fed in early infancy and who also lacked piped water in their homes (for children with both characteristics , 95% ). The high prevalence of rotavirus and its association OR ϭ 6.8 CI ϭ 3.6-12.8 with severe diarrhea underscores the need for rotavirus vaccines. Interventions to educate mothers and improve access to safe water should augment the impact of rotavirus vaccines in preventing severe diarrhea.