Significant Reduction In Bacterial Counts Research Articles

Ciprofloxacin plus erythromycin or ambroxol ameliorates endotracheal tube-associated Pseudomonas aeruginosa biofilms in a rat model

Background and objectivePseudomonas aeruginosa is a multi-drug resistant bacterium, with its biofilm-growing mucoid (alginate-producing) strains being particularly resistant. As atomized drug administration is a common practice in pediatric patients, we compared the effect of inhalational therapy with erythromycin plus ciprofloxacin, with that of ambroxol plus ciprofloxacin, against biofilm producing strains of P. aeruginosa. ResultsBoth combined treatment regimens were associated with a significant reduction in bacterial counts in endotracheal (ET) tubes and lungs, as compared to that observed with ambroxol and erythromycin monotherapies (P<0.05). Ciprofloxacin plus ambroxol appeared to have a higher efficacy than ciprofloxacin plus erythromycin, both in lowering bacterial counts (P<0.05) and in disrupting the structural integrity of biofilm. Histopathological changes in the lungs were milder in the two combined treatment groups, as compared to that in groups treated with single drugs. ConclusionErythromycin or ambroxol in combination with ciprofloxacin could eliminate P. aeruginosa biofilms. When combined with ciprofloxacin, ambroxol outperformed erythromycin in eradicating P. aeruginosa biofilm.

Antimicrobial and anti-adherence activity of various combinations of coffee-chicory solutions on Streptococcus mutans: An in-vitro study.

Context:Several studies have demonstrated the activity of natural plants on the dental biofilm and caries development. But few studies on the antimicrobial activity of coffee-based solutions were found in the literature. Further there was no study available to check the antimicrobial effect of coffee solutions with different percentages of chicory in it.Aims:To evaluate the antimicrobial activity of different combinations of coffee-chicory solutions and their anti-adherence effect on Streptococcus mutans to glass surface.Materials and Methods:Test solutions were prepared. For antimicrobial activity testing, tubes containing test solution and culture medium were inoculated with a suspension of S. mutans followed by plating on Brain Heart Infusion (BHI) agar. S. mutans adherence to glass in presence of the different test solutions was also tested. The number of adhered bacteria (CFU/mL) was determined by plating method.Statistical Analysis:Statistical significance was measured using one way ANOVA followed by Tukey's post hoc test. P value < 0.05 was considered statistically significant.Results:Pure chicory had shown significantly less bacterial count compared to all other groups. Groups IV and V had shown significant reduction in bacterial counts over the period of 4 hrs. Regarding anti-adherence effect, group I-IV had shown significantly less adherence of bacteria to glass surface.Conclusions:Chicory exerted antibacterial effect against S. mutans while coffee reduced significantly the adherence of S. mutans to the glass surface.

The antimicrobial effects of helium and helium–air plasma on Staphylococcus aureus and Clostridium difficile

Healthcare-associated infections (HCAI) affect 5-10% of acute hospital admissions. Environmental decontamination is an important component of all strategies to prevent HCAI as many bacterial causes survive and persist in the environment, which serve as ongoing reservoirs of infection. Current approaches such as cleaning with detergents and the use of chemical disinfectant are suboptimal. We assessed the efficacy of helium and helium-air plasma in killing Staphylococcus aureus and Clostridium difficile on a glass surface and studied the impact on bacterial cells using atomic force microscopy (AFM). Both plasma types exhibited bactericidal effects on Staph.aureus (log3·6 - >log7), with increased activity against methicillin-resistant strains, but had a negligible effect on Cl.difficile spores (<1log). AFM demonstrated cell surface disruption. The addition of air increased the microbicidal activity of the plasma and decreased the exposure time required for an equivalent log reduction. Further evaluation of cold plasma systems is warranted with, for example, different bacteria and on surfaces more reminiscent of the health care environment as this approach has potential as an effective decontaminant. Many bacterial causes of healthcare infection can survive in the inanimate environment for lengthy periods and be transmitted to patients. Furthermore, current methods of environmental decontamination such as detergents, chemical disinfectants or gaseous fumigation are suboptimal for a variety of reasons. We assessed the efficacy of helium and helium-air plasma as a decontaminant and demonstrated a significant reduction in bacterial counts of Staphylococcus aureus on a glass surface. Atomic force microscopy morphologically confirmed the impact on bacterial cells. This approach warrants further study as an alternative to current options for hospital hygiene.

Ozone therapy as an adjunct to vancomycin enhances bacterial elimination in methicillin resistant Staphylococcus aureus mediastinitis

BackgroundWe aimed to investigate the influence of intraperitoneal ozone therapy on bacterial elimination and mediastinal inflammation in experimental Staphylococcus aureus mediastinitis. Materials and methodsForty Wistar-Albino rats were randomized into five groups (eight per group) as follows: uncontaminated group, untreated contaminated group, ozone group, vancomycin group, and vancomycin + ozone group. Uncontaminated group underwent upper median sternotomy. The remaining four groups were inoculated with 0.5 mL 108 colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Untreated contaminated group had no treatment. Rats in the vancomycin group received intramuscular vancomycin (40 mg/kg/d), and ozone was administered intraperitoneally (70 μg/mL, 1 mg/kg/d) in the ozone group for the treatment of mediastinitis. Vancomycin + ozone group rats were treated by the combination of both methods. At the end of 10 d, quantitative bacterial cultures and sternal tissue samples were obtained for determination of bacterial counts and histologic degree of inflammation. ResultsBoth the vancomycin and the ozone treatments caused significant reduction of bacterial counts in quantitative bacterial cultures. Combination of vancomycin and ozone treatments resulted in further reduction of bacterial counts in mediastinum and sternum. Histologic examination of tissue samples revealed significant reduction in severity of mediastinitis related inflammation in vancomycin and vancomycin + ozone groups compared with untreated contaminated group. ConclusionsOzone therapy as an adjunct to vancomycin leads to enhanced bacterial elimination in infected sternal and mediastinal tissues in experimental methicillin-resistant Staphylococcus aureus mediastinitis. The benefit of adjuvant ozone therapy is suggested to be related to its bactericidal effect.

Antimicrobial effect of turmeric (Curcuma longa) on chicken breast meat contamination

The aim of this study was to evaluate the efficacy of turmeric (Curcuma longa), also known in Brazil as saffron, on the reduction of Staphylococcus aureus and Escherichia coli counts in chicken meat. Forty breast meat samples were divided in two groups (A and B). In group A, 10³-10(4)E. coli (ATCC 25922) cells were inoculated and group B samples were inoculated with 10(4)-10(5)S. aureus (ATCC 9801) cells, after which each group was divided in three samples. The first sample was analyzed immediately after inoculation. The second sample (control group) was stored at 4 ºC for 48 hours and turmeric at 1% (w/w) was added to the third sample, which was homogenized and then stored under the same conditions as the second sample. E. coli and S. aureus were enumerated in all samples. Mean bacterial counts determined for the control samples and for the samples with turmeric addition after 48h of storage were 1.83 x 10(4) CFU g-1 and 1.80 x 10(4) CFU g-1 for S. aureus, and 9.36 x 10³ CFU g-1 and 7.25 x 10³ CFU g-1 for E. coli, respectively. The results showed that there was no significant reduction in bacterial counts with the addition of 1% turmeric to chicken breast meat.

Comparative evaluation of antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate and Tween as surfactants: An in vivo study

The aim of the study was to determine the antibacterial property and substantivity of chlorhexidine containing dentifrices with sodium lauryl sulfate (SLS) and Tween as surfactants. It is a double-blind cross over the study, a total of 20 children within their mixed dentition period (7-13 year) having Streptococci mutans count more than 10(6) were selected for the main study. Three types of chlorhexidine containing dentifrices were used with a washout period of 1 week. Out of the three toothpastes, one was without surfactant and other two toothpastes contained SLS and Tween as surfactants respectively. 20 volunteers brushed for 1 min during the study day with their assigned toothpaste. Saliva samples were collected before brushing, immediately after brushing and 1, 3, 5, and 7 hand sent for microbial analysis. The culture carried out by inoculating saliva sample onto Mitis salivarius agar for selective isolation of S. mutans followed by counting of colony forming unit. Group I and III (Chlorhexidine and CHX + Tween) had shown statistically significant reduction in bacterial count until 7 h when compared to their baseline values ( P < 0.001). Group II toothpaste (CHX + SLS) had shown significant reduction in bacterial count until 3 h only. On inter group comparison, Group III had shown good amount of percentage reduction in bacterial count when compared to other groups. CHX + Tween toothpaste had shown statistically significant reduction in antibacterial activity and substantivity than other groups. These findings show chlorhexidine containing toothpaste with non-ionic surfactant will be able to maintain the antibacterial property and substantivity of chlorhexidine.

광역동 치료가 구강 내에서 분리한 수종의 Streptococcus mutans의 생존력에 미치는 영향

Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. The aim of this study was to evaluate the effect of PDT on Streptococcus mutans in planktonic conditions, previously treated with different photosensitive concentrations of erythrosine, using halogen and LED curing unit as a light source. And we compared the effects of PDT on six strains of S. mutans isolated from oral cavity and reference strain. As a result, S. mutans was susceptible to the combination of hand held photopolymerizer (HHP) and erythrosine. The higher concentration of erythrosine in the presence of light irradiation induced greater effects in reduction of viability of S. mutans. Isolated S. mutans showed a significant reduction in bacterial counts of the groups submitted to PDT compared to the control groups. And they appeared to be similar or slightly lower antimicrobial effect compared with reference strain. However, the difference was not significant (p < 0.05). In conclusion, PDT using erythrosine as a photosensitizing agent and HHP as a light source could be an efficient option for diseases caused by S. mutans.

862 DEVELOPMENT AND EVALUATION OF A NOVEL GEL-BASED URETERAL STENT WITH BIOFILM RESISTANT CHARACTERISTICS

You have accessJournal of UrologyTechnology & Instruments: Surgical Education & Skills Assessment/Ureteroscopy I1 Apr 2012862 DEVELOPMENT AND EVALUATION OF A NOVEL GEL-BASED URETERAL STENT WITH BIOFILM RESISTANT CHARACTERISTICS Brian M. Rosman, Joao A. Barbosa, Marc Cendron, Alan B. Retik, Hiep T. Nguyen, and Bartley G. Cilento Brian M. RosmanBrian M. Rosman Boston, MA More articles by this author , Joao A. BarbosaJoao A. Barbosa Boston, MA More articles by this author , Marc CendronMarc Cendron Boston, MA More articles by this author , Alan B. RetikAlan B. Retik Boston, MA More articles by this author , Hiep T. NguyenHiep T. Nguyen Boston, MA More articles by this author , and Bartley G. CilentoBartley G. Cilento Boston, MA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.955AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Ureteral stents are utilized following surgery in order to ensure the patency of the ureter. Current stents, while effective at maintaining a ureteral lumen, are both a cause of discomfort for the patient and a substrate for bacterial growth. This increased propensity for biofilm formation can be a nidus for growth leading to infection, and a reason for early removal of a stent before it is clinically indicated. A new stent material, composed of a highly hydrated partially hydrolyzed polyacrylonitrile, is believed to have antibacterial properties. The objective of this study is to evaluate the biofilm growth and antibacterial properties of this novel stent. METHODS Sections of the experimental and conventional (control) stent (polymer stent, Boston Scientific, Natick MA) were incubated for 3 days in the following: Soy Trypticase broth (“broth”), broth and sterile urine, and broth and swine blood. After the incubation period, 5mL of broth laden with J96 human pathogenic E.Coli (OD 0.6-0.7 relative to sterile broth) was added to each vial. One segment of the control and experimental stents were removed at 3, 6, 9, 12, and 15 days. At each time point, the stents were washed in sterile saline to remove any bacteria laden fluid, leaving only the biofilm. After 4 successive washes, the stents were sonicated in an ultrasonic bath to break up any biofilm present. The solution was diluted and plated on permissive media. Subsequent quantification of bacterial growth by CFU counts provides a direct assessment of the biofilm growth. Incubated stents were sent for Scanning Electron Microscopy (SEM) imaging to confirm biofilm formation. RESULTS Experimental stents demonstrated significant reductions in bacterial counts when compared to control stents in all conditions tested: in broth (100 to 1000 fold reduction); in broth + urine (10 to 100-fold reduction); and broth + blood (10 to 100 fold reduction). SEM imaging demonstrated biofilm formation on both types of stents in all media, with a relative reduction in apparent cell debris and bacteria on the experimental stent. CONCLUSIONS In this study, the gel based stent shows a demonstrable reduction in bacterial counts and biofilm formation. The use of this novel stent may reduce the risk of infection associated with stent usage, avoiding the need for prophylactic antibiotics. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e352 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Brian M. Rosman Boston, MA More articles by this author Joao A. Barbosa Boston, MA More articles by this author Marc Cendron Boston, MA More articles by this author Alan B. Retik Boston, MA More articles by this author Hiep T. Nguyen Boston, MA More articles by this author Bartley G. Cilento Boston, MA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Cefoxitin as an Alternative to Carbapenems in a Murine Model of Urinary Tract Infection Due to Escherichia coli Harboring CTX-M-15-Type Extended-Spectrum β-Lactamase

We investigated the efficiency of the cephamycin cefoxitin as an alternative to carbapenems for the treatment of urinary tract infections (UTIs) due to Escherichia coli producing CTX-M-type extended-spectrum β-lactamases. The susceptible, UTI-inducing E. coli CFT073-RR strain and its transconjugant CFT073-RR Tc (pbla(CTX-M-15)), harboring a bla(CTX-M-15) carrying-plasmid, were used for all experiments. MICs of cefoxitin (FOX), ceftriaxone (CRO), imipenem (IMP), and ertapenem (ETP) for CFT073-RR and CFT073-RR Tc (pbla(CTX-M-15)) were 4 and 4, 0.125 and 512, 0.5 and 0.5, and 0.016 and 0.032 μg/ml, respectively. Bactericidal activity was similarly achieved in vitro against the two strains after 3 h of exposure to concentrations of FOX, IMI, and ETP that were 2 times the MIC, whereas CRO was not bactericidal against CFT073-RR Tc (pbla(CTX-M-15)). The frequencies of spontaneous mutants of the 2 strains were not higher for FOX than for IMP or ETP. In the murine model of UTIs, mice infected for 5 days were treated over 24 h. Therapeutic regimens in mice (200 mg/kg of body weight every 3 h or 4 h for FOX, 70 mg/kg every 6 h for CRO, 100 mg/kg every 2 h for IMP, and 100 mg/kg every 4 h for ETP) were chosen in order to reproduce the percentage of time that free-drug concentrations above the MIC are obtained in humans with standard regimens. All antibiotic regimens produced a significant reduction in bacterial counts (greater than 2 log(10) CFU) in kidneys and bladders for both strains (P < 0.001) without selecting resistant mutants in vivo, but the reduction obtained with CRO against CFT073-RR Tc (pbla(CTX-M-15)) in kidneys was significantly lower than that obtained with FOX. In conclusion, FOX appears to be an effective therapeutic alternative to carbapenems for the treatment of UTIs due to CTX-M-producing E. coli.

Chemomechanical preparation by hand instrumentation and by Mtwo engine-driven rotary files, an ex vivo study

Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root canal preparation with stainless steel hand files, taper 0.02 and nickel-titanium Mtwo files with taper 0.04-0.06. Study Design: 40 extracted human teeth were sterilized, and then inoculated with Enterococcus faecalis (ATCC 29212). After 6 day incubation time the root canals were prepared by hand with K-files (n=20) and by engine-driven Mtwo files (VDW, Munich, Germany) (n=20). Irrigation was carried out with 2.5% NaOCl in both cases. Samples were taken and determined in colony forming units (CFU) from the root canals before and after the preparation with instruments #25 and #35. Results: Significant reduction in bacterial count was determined after filing at both groups. The number of bacteria kept on decreasing with the extension of apical preparation diameter. There was no significant difference between the preparation sizes in the bacterial counts after hand or engine-driven instrumentation at the same apical size. Statistical analysis was carried out with Mann-Whitney test, paired t-test and independent sample t-test. Conclusions: Significant reduction in CFU was achieved after the root canal preparation completed with 2.5% NaOCl irrigation, both with stainless steel hand or nickel-titanium rotary files. The root canal remained slightly infected after chemo mechanical preparation in both groups. Key words:Chemomechanical preparation, root canal disinfection, nickel-titanium, conicity, greater taper, apical size.

Mannosylated gelatin nanoparticles bearing isoniazid for effective management of tuberculosis

The mannosylated gelatin nanoparticles (Mn-GNPs) were prepared for the selective delivery of an antitubercular drug, isoniazid (INH), to the alveolar macrophages. The gelatin nanoparticles (GNPs) were prepared by using a two-step desolvation method and efficiently conjugated with mannose. Various parameters such as particle size, polydispersity index, zeta potential, % entrapment efficiency, in vitro drug release, macrophage uptake, in vivo biodistribution, antitubercular activity and hepatotoxicity of plain and Mn-GNPs were determined. The size of nanoparticles (both plain and Mn-GNPs) was found to be in range of 260–380 nm, and maximum drug payload was found to be 40–55%. Average particle size of Mn-GNPs was more, whereas drug entrapment was lesser compared to plain GNPs. The organ distribution studies demonstrated the efficiency of Mn-GNPs for spatial delivery of INH to alveolar tissues. Intravenous administration of INH loaded Mn-GNPs (I-Mn-GNPs) resulted in significant reduction in bacterial counts in the lungs and spleen of tuberculosis-infected (TB-infected) mice and also reduction in the hepatotoxicity of the drug. This study revealed that mannose conjugated GNPs may be explored as potential carrier for safer and efficient management of TB through targeted delivery of INH when compared to plain GNPs and free drug.

Microbiological quality of high-pressure (HP) treated fresh cheese of bovine milk

High pressure (HP) treatment at ambient temperature (25°C) was applied to freshly-prepared rennetcoagulated cheese of bovine (pasteurized) milk and the microbiological quality was examined for up to Day 31 using a Central Composite Design (CCD) of experiment. Bacterial counts were significantly (p < 0.05) reduced at the highest applied pressure. Estimated shelf-life was 17 days for control samples but approached 31 days at HP treatments of 150 MPa at 1 and 15 min. Treatments above 150 MPa with treatment time up to 29 min caused highly significant reductions in bacterial counts (p < 0.01 to p < 0.001). Gram-positive cocci and rods as well as Gram-negative rods were found during spoilage of the fresh cheese.

Gelatin nanocarriers as potential vectors for effective management of tuberculosis

The aim of the research work was to develop and characterize rifampicin (RIF) loaded gelatin nanoparticulate delivery system for the effective management of tuberculosis. Gelatin nanoparticles (GPs) containing RIF were prepared using two-step desolvation method. Formulations were characterized through transmission electron microscopy (TEM), atomic force microscopy (AFM), size and size distribution analysis, polydispersity index (PDI), zeta potential, percent drug entrapment, percent nanoparticulate yield and in vitro drug release. Formulations were further characterized for in vitro cytotoxicity, in vivo biodistribution, and antitubercular activity. The nanoparticles were found to be spherical in shape. The size of nanoparticles was found to be 264 ± 11.2 nm with low PDI suggesting the narrow particle size distribution. The drug release showed the biphasic pattern of release i.e. initial burst followed by a sustained release pattern. The cytotoxicity studies revealed that nanoparticles are safe, non toxic as compared to free drug. In vivo biodistribution study showed higher localization of RIF loaded GPs in various organs, as compared to plain RIF solution in PBS (pH 7.4). In contrast to free drug, the nanoparticles not only sustained the plasma level but also enhanced the AUC and mean residence time (MRT) of the drug, suggesting improved pharmacokinetics of drug. RIF GPs additionally resulted in significant reduction in bacterial counts in the lungs and spleen of TB-infected mice. Hence, GPs hold promising potential for increasing drug targetability vis a vis reducing dosing frequency with the interception of minimal side effects, for efficient management of tuberculosis.

Comparison of Tigecycline and Vancomycin for Treatment of Experimental Foreign-Body Infection Due to Methicillin-Resistant Staphylococcus aureus

Twice-daily 7-day regimens of tigecycline (7 mg/kg) and vancomycin (50 mg/kg) were compared in a rat tissue cage model of chronic foreign-body infection due to methicillin (meticillin)-resistant Staphylococcus aureus strain MRGR3. Subcutaneously administered tigecycline reached levels in tissue cage fluid that were nearly equivalent or slightly superior to the antibiotic MIC (0.5 microg/ml) for strain MRGR3. After 7 days, equivalent, significant reductions in bacterial counts were recorded for tigecycline-treated and vancomycin-treated rats, compared with those for untreated animals.

Preoperative antiseptics in clean/contaminated maxillofacial and oral surgery: prospective randomized study

In order to show the effectiveness of preoperative antiseptic mouthwash the authors undertook a prospective study in 120 patients who underwent elective surgery under general or local anesthesia. Patients were allocated toone of 4 groups, depending on whether the oral cavity was washed preoperatively with 1% cetrimide, chlorhexidine, povidon-iodine or sterilized normal saline solution (control group). Aerobic and anaerobic bacterial samples were taken from the inferior vestibulum mucosa before surgery, 5 min after the start of the operation and at the end of the procedure. The results show a statistically significant reduction in bacterial counts during procedures in which antiseptics are used to wash the oral cavity preoperatively. 1% cetrimide solution was the most successful in reducing intra-oral bacterial counts and produced the longest lasting antiseptic effect. Chlorhexidine is a good option for procedures longer than 1 hour, while povidon-iodine is recommended for procedures lasting up to 1 hour. Normal saline reduced bacterial counts in the specimen taken 5 min after washing but this short-lasting effect is due to mechanical cleansing rather than the antiseptic effect.

ENHANCED IMMUNE RESPONSE OF RED DEER (CERVUS ELAPHUS) TO LIVE RB51 VACCINE STRAIN USING COMPOSITE MICROSPHERES

Brucellosis is an important zoonotic disease of nearly worldwide distribution. The occurrence of the infection in humans is largely dependent on the prevalence of brucellosis in animal reservoirs, including wildlife. The current vaccine used for cattle Brucella abortus strain RB51, has proven ineffective in protecting bison (Bison bison) and elk (Cervus nelsoni) from infection and abortion. To test possible improvements in vaccine efficacy, a novel approach of immunization was examined from April 2004 to November 2006 using alginate composite microspheres containing a nonimmunogenic, eggshell-precursor protein of the parasite Fasciola hepatica (Vitelline protein B, VpB) to deliver live vaccine strain RB51. Red deer (Cervus elaphus), used as a model for elk, were vaccinated orally (PO) or subcutaneously (SC) with 1.5x10(10) viable organisms per animal. Humoral responses postvaccination (immunoglobulin G [IgG] levels), assessed at different time points, indicated that capsules containing live RB51 elicited an anti-Brucella specific IgG response. Furthermore, the encapsulated vaccine elicited a cell-mediated response that the nonencapsulated vaccinates failed to produce. Finally, red deer were challenged with B. abortus strain 19 by conjunctival exposure. Only animals that received encapsulated RB51 vaccine by either route exhibited a significant reduction in bacterial counts in their spleens. These data suggest that alginate-VpB microspheres provide a method to enhance the RB51 vaccine performance in elk.

Efficacy of the Combination of Tachyplesin III and Clarithromycin in Rat Models of Escherichia coli Sepsis

We investigated the efficacy of tachyplesin III and clarithromycin in two experimental rat models of severe gram-negative bacterial infections. Adult male Wistar rats were given either (i) an intraperitoneal injection of 1 mg/kg Escherichia coli 0111:B4 lipopolysaccharide or (ii) 2 x 10(10) CFU of E. coli ATCC 25922. For each model, the animals received isotonic sodium chloride solution, 1 mg/kg tachyplesin III, 50 mg/kg clarithromycin, or 1 mg/kg tachyplesin III combined with 50 mg/kg clarithromycin intraperitoneally. Lethality, bacterial growth in the blood and peritoneum, and the concentrations of endotoxin and tumor necrosis factor alpha (TNF-alpha) in plasma were evaluated. All the compounds reduced the lethality of the infections compared to that for the controls. Tachyplesin III exerted a strong antimicrobial activity and achieved a significant reduction of endotoxin and TNF-alpha concentrations in plasma compared to those of the control and clarithromycin-treated groups. Clarithromycin exhibited no antimicrobial activity but had a good impact on endotoxin and TNF-alpha plasma concentrations. A combination of tachyplesin III and clarithromycin resulted in significant reductions in bacterial counts and proved to be the most-effective treatment in reducing all variables measured.

A novel cell wall-anchored peptidoglycan hydrolase (autolysin), IspC, essential for Listeria monocytogenes virulence: genetic and proteomic analysis

We have recently concluded that a Listeria monocytogenes 86 kDa immunogenic surface protein, IspC, is a cell wall-anchored peptidoglycan hydrolase (autolysin), capable of degrading the cell wall peptidoglycan of the bacterium itself. To determine if this enzyme has any biological functions and/or plays a role in virulence, we in-frame-deleted the ispC gene from the L. monocytogenes chromosome. This DeltaispC mutant exhibited complete abrogation of expression of IspC and displayed no defects in in vitro growth, colony and microscopic morphologies, or biochemical characteristics. Lack of IspC led to attenuated virulence in mice, evidenced by a significant reduction in bacterial counts in livers and brains and no mortality compared with the wild-type. Furthermore, the data from assays using various eukaryotic cells for adhesion, invasion, actin tail formation, plaque formation and intracellular growth indicated that the mutant was severely attenuated in virulence in a cell culture model in a cell type-dependent manner. The findings that (i) the mutant was impaired for adhesion to certain eukaryotic cells, and (ii) both purified IspC and its C-terminal cell wall-binding domain were capable of binding sheep choroid plexus (SCP) epithelial cells and Vero cells, supported the role of IspC as an adhesin in virulence. The DeltaispC mutant exhibited a marked defect in adhesion to and invasion of SCP cells but not human brain microvascular endothelial cells (HBMEC), suggesting that IspC is necessary for crossing the blood-cerebrospinal fluid barrier. Proteomic and immunological analysis showed a reduced surface expression of some known or putative virulence factors (e.g. ActA, InlC2 and a flagellin homologue, FlaA) due to IspC deficiency. Altogether, this study demonstrates that IspC, expressed as a minor autolysin in vitro, is not important for cell division or separation but is essential for full virulence of L. monocytogenes in vivo.

Triphala Promotes Healing of Infected Full-Thickness Dermal Wound

Infection is a major problem in the management of wounds. Even though the development of synthetic antimicrobial agents persists, drug resistance and toxicity hinder their way. Many plants with multi-potent pharmaceutical activities may offer better treatment options, and Triphala (dried fruits of Terminalia chebula, Terminalia bellirica, and Phyllanthus emblica) are potential formulations evaluated for healing activity on infected wound as it possesses numerous activities. Alcoholic extract of Triphala has shown in vitro antimicrobial activity against wound pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pyogenes. An ointment was prepared from the Triphala extract (10% w/w) and assessed for in vivo wound healing on infected rat model by rate of healing, bacterial count, biochemical analysis, and expression of matrix metalloproteinases. The treated group has shown significantly improved wound closure. Assessment of granulation tissue on every fourth day showed significant reduction in bacterial count with significant level of collagen, hexosamine, uronic acid, and superoxide dismutase in the treated group (P < 0.01). Reduction of matrix metalloproteinase expression observed in the treated group by gelatin zymography and immunoblotting confirms our in vivo assessment. The above results showed the antibacterial, wound healing, and antioxidant activities of Triphala ointment, necessary for the management of infected wounds. Active principles of the Triphala may be further evaluated and used as an excellent therapeutic formulation for infected wounds.

Efficacy of colistin/rifampin combination in experimental rat models of sepsis due to a multiresistant Pseudomonas aeruginosa strain*

To investigate the efficacy of rifampin and colistin in three experimental rat models of Pseudomonas aeruginosa sepsis. Prospective, randomized, controlled animal study. Research laboratory in a university hospital. Adult male Wistar rats. Adult male Wistar rats were given a) an intraperitoneal injection of 1 mg of P. aeruginosa 10 lipopolysaccharide; b) 2 x 10(10) colony-forming units of P. aeruginosa ATCC 27853; and c) 2 x 10(10) colony-forming units of one clinically multiresistant strain of P. aeruginosa. For each model, all animals were randomized to receive intravenously isotonic sodium chloride solution, 10 mg/kg rifampin, 1 mg/kg colistin, and 10 mg/kg rifampin plus 1 mg/kg colistin. Lethality, bacterial growth in blood and peritoneum, and endotoxin and tumor necrosis factor-alpha concentrations in plasma were measured. Colistin exerted a strong antimicrobial activity and achieved a significant reduction of plasma endotoxin and tumor necrosis factor-alpha concentration compared with control and rifampin-treated groups. Rifampin exhibited no antimicrobial activity with no substantial impact on endotoxin and tumor necrosis factor-alpha plasma concentrations. The combination of colistin and rifampin resulted in a significant reduction in bacterial count compared with colistin monotherapy, whereas no significant difference was found in positive hem cultures and mortality rates between the two groups. Colistin and rifampin might have a role in the therapy of multiresistant P. aeruginosa infection.