A Natural Alternative Treatment for Urinary Tract Infections: Itxasol©, the Importance of the Formulation.

Genito-urinary tract infections have a high incidence in the general population, being more prevalent among women than men. These diseases are usually treated with antibiotics, but very frequently, they are recurrent and lead to the creation of resistance and are associated with increased morbidity and mortality. For this reason, it is necessary to develop new compounds for their treatment. In this work, our objective is to review the characteristics of the compounds of a new formulation called Itxasol© that is prescribed as an adjuvant for the treatment of UTIs and composed of ß-arbutin, umbelliferon and n-acetyl cysteine. This formulation, based on biomimetic principles, makes Itxasol© a broad-spectrum antibiotic with bactericidal, bacteriostatic and antifungal properties that is capable of destroying the biofilm and stopping its formation. It also acts as an anti-inflammatory agent, without the adverse effects associated with the recurrent use of antibiotics that leads to renal nephrotoxicity and other side effects. All these characteristics make Itxasol© an ideal candidate for the treatment of UTIs since it behaves like an antibiotic and with better characteristics than other adjuvants, such as D-mannose and cranberry extracts.

Spectroscopic and Antibacterial Properties of CuONPs from Orange, Lemon and Tangerine Peel Extracts: Potential for Combating Bacterial Resistance.

Green synthesis of nanoparticles using citrus peel extracts is known to be environmentally friendly and non-toxic when compared to chemical methods. In this study, different citrus peel extracts obtained with the solvents acetone and distilled water were used to synthesize copper oxide nanoparticles (CuONPs). The nanoparticles were characterized using cyclic voltammetry, ultraviolet-visible spectroscopy, energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The absorption spectrum of CuONPs prepared with acetone exhibited characteristic peaks at the wavelengths between 280-293 nm, while those with distilled water had peaks at 290 nm. The acetone-synthesized CuONPs were spherical while those produced using distilled water were rod-shaped. Based on EDS, the analysis revealed a trace spectrum of CuO nanoparticles with different weight compositions that varied with the type of citrus peel and solvent used. FTIR measurements were carried out in the range of 500-4000 cm-1 for citrus peel extract mediated CuONPs. The spectra had five vibrations occurring at approximately 473, 477, 482, 607 and 616 cm-1 for all samples, which can be attributed to the vibrations of CuO, validating the formation of highly pure CuONPs.

Evaluation of the Antibacterial Activity of Spathiphyllum wallisii Extracts Against Human Pathogenic Bacteria.

BACKGROUND AND OBJECTIVE: The urgent of finding new antibiotics due to the rising of antibiotic-resistant bacteria. The plant is the main source of new antibiotic substances. The purpose of this research was to evaluate the antibacterial activity of Spathiphyllum wallisii extracts against nine human pathogenic bacteria. MATERIALS AND METHODS: The stalks, leaf, rhizome and root of S. wallisii were extracted by using hexane, dichloromethane, ethyl acetate, ethanol and methanol. The disc diffusion assay was used to screen the antibacterial activity of S. wallisii extracts. Broth dilution and colorimetric assay were used to determine the Minimal inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) values of extracts. RESULTS: The lowest MIC values at 0.048 mg mL-1 were presented in the stalks extract with dichloromethane, ethyl acetate, methanol and ethanol against B. subtilis TISTR 008, the leaf extracted with hexane, dichloromethane, ethyl acetate, methanol and ethanol against B. subtilis TISTR 008; the leaf extracted with ethyl acetate, methanol and ethanol against S. aureus TISTR 1466, the leaf extracted with dichloromethane, ethyl acetate, methanol and ethanol against S. aureus PK; the rhizome extracted with methanol against S. aureus PK. The lowest of MBC value of 0.048 mg mL-1 was obtained from methanolic rhizome extract against B. subtilis TISTR 008. CONCLUSION: The methanolic rhizome extract of S. wallisii demonstrated the highest of pathogenic bacterial growth inhibition. This is the first report about the antibacterial activity of S. wallisii extracts that will add new information in natural drug discovery and development in industrial pharmacology.

Potential of antimicrobial topical gel with synthesized biogenic silver nanoparticle using Rhodomyrtus tomentosa leaf extract and silk sericin.

OBJECTIVE: Silver nanoparticles synthesized using Rhodomyrtus tomentosa leaf extract and silk sericin were used to functionalize carbopol 940 gel for topical applications. RESULTS: UV-vis spectra presented surface plasmon resonance at 426 nm, transmission electron microscopy revealed that nanoparticles were spherical with an average size of 25-50 nm. X-ray diffraction presented crystalline silver nanoparticles with zeta potential of ≈ - 30 mV. FTIR spectra showed a reduction of silver nitrate indicated by the shift in -OH at 2958 cm-1. The silver nanoparticle demonstrated broad-spectrum antimicrobial activity against Gram-positive, Gram-negative and fungi with MIC ranging between 0.26 and 2.10 µg mL-1, respectively. MIC of hydrogel ranged between 1.05-2.10 µg mL-1 with cell viability of 89%. Spreadability and extrudability of gel were 9.3 ± 0.85 s and 19.85 ± 0.03%, respectively with first order of fickian diffusion. CONCLUSIONS: The silver nanoparticle gel exhibited an effective antimicrobial property, hence can be exploited for topical applications.

Phenolic and Nonpolar Fractions of Elaeagnus rhamnoides (L.) A. Nelson Extracts as Virulence Modulators-In Vitro Study on Bacteria, Fungi, and Epithelial Cells.

Butanol extracts from leaves, twigs, and fruits of Elaeagnus rhamnoides (L.) A. Nelson (sea buckthorn, SBT) were fractionated into phenolic and nonpolar lipid components, the chemical composition of which was analyzed. Assuming that an effect on natural microbiota and host epithelial cells needs to be assessed, regardless of the purpose of using SBT formulations in vivo, the minimal inhibitory/biocidal/fungicidal concentrations (MICs/MBCs/MFCs) of the fractions and reference phytocompounds were screened, involving 17 species of Gram-positive and Gram-negative bacteria and Candida species. The MICs of SBT extracts were in the range of 0.25⁻2.0 mg∙mL−1. Since direct antimicrobial activity of the extracts was quite low and variable, the impact of subMIC on the important in vivo persistence properties of model microorganisms S. aureus and C. albicans was evaluated. Tests for adhesion and biofilm formation on an abiotic surface and on surfaces conditioned with fibrinogen, collagen, plasma, or artificial saliva showed the inhibitory activity of the fractions. The effects on fluorescein isothiocyanate (FITC)-labeled staphylococci adhesion to fibroblasts (HFF-1) and epithelial cells (Caco-2), and on fungal morphogenesis, indicated that SBT extracts have high antivirulence potential. Cytotoxicity tests (MTT reduction) on the standard fibroblast cell line showed variable biological safety of the fractions depending on their composition and concentration. The new information afforded by this study, additional to that already known, is of potential practical value in the application of SBT-derived preparations as antivirulence agents.

Enhanced antibacterial effects of green synthesized ZnO NPs using Aristolochia indica against Multi-drug resistant bacterial pathogens from Diabetic Foot Ulcer.

BACKGROUND: Increased incidence of Multi-drug resistance in microorganisms has become the greatest challenge in the treatment of Diabetic Foot Ulcer (DFU) and urges the need of a new antimicrobial agent. In this study, we determined the bactericidal effects of ZnO nanoparticles (ZnO NPs) green synthesized from Aristolochia indica against Multi-drug Resistant Organisms (MDROs) isolated from pus samples of DFU patients attending in a tertiary care hospital in South India. METHODS: ZnO NPs were characterized by UV-vis-DRS spectroscopy, Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) and for its zeta potential value. MIC/MBC assays were performed to determine bactericidal or bacteriostatic effects. Time-kill assays, Protein leakage and Flow cytometric analysis evaluated bacterial cell death at 1x MIC and 2x MIC concentrations of ZnO NPs. RESULTS: ZnO NPs of size 22.5nm with a zeta potential of -21.9±1mV exhibited remarkable bactericidal activity with MIC/MBC ranging from 25 to 400µg/ml with a significant reduction in viable count from 2h onwards. Protein leakage and Flow cytometric analysis confirmed bacterial cell death due to ZnO NPs. CONCLUSION: This study concluded that green synthesis protocol offers reliable, eco-friendly approach towards the development of antimicrobial ZnO NPs to combat antibiotic drug resistance.

A post-planktonic era of in vitro infectious models: issues and changes addressed by a clinically relevant wound like media.

Medical science is pitted against an ever-increasing rise in antibiotic tolerant microorganisms. Concurrently, during the past decade, biofilms have garnered much attention within research and clinical practice. Although the significance of clinical biofilms is becoming very apparent, current methods for diagnostics and direction of therapy plans in many hospitals do not reflect this knowledge; with many of the present tools proving to be inadequate for accurately mimicking the biofilm phenomenon. Based on current findings, we address some of the fundamental issues overlooked by clinical labs: the paradigm shifts that need to occur in assessing chronic wounds; better simulation of physiological conditions in vitro; and the importance of incorporating polymicrobial populations into biofilm models. In addition, this review considers using a biofilm relevant in vitro model for cultivating and determining the antibiotic tolerance and susceptibility of microorganisms associated with chronic wounds. This model presents itself as a highly rapid and functional tool that can be utilized by hospitals in an aim to improve bedside treatments.

Perilla Oil Has Similar Protective Effects of Fish Oil on High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease and Gut Dysbiosis.

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in developed countries. Recent studies indicated that the modification of gut microbiota plays an important role in the progression from simple steatosis to steatohepatitis. Epidemiological studies have demonstrated consumption of fish oil or perilla oil rich in n-3 polyunsaturated fatty acids (PUFAs) protects against NAFLD. However, the underlying mechanisms remain unclear. In the present study, we adopted 16s rRNA amplicon sequencing technique to investigate the impacts of fish oil and perilla oil on gut microbiomes modification in rats with high-fat diet- (HFD-) induced NAFLD. Both fish oil and perilla oil ameliorated HFD-induced hepatic steatosis and inflammation. In comparison with the low-fat control diet, HFD feeding significantly reduced the relative abundance of Gram-positive bacteria in the gut, which was slightly reversed by either fish oil or perilla oil. Additionally, fish oil and perilla oil consumption abrogated the elevated abundance of Prevotella and Escherichia in the gut from HFD fed animals. Interestingly, the relative abundance of antiobese Akkermansia was remarkably increased only in animals fed fish oil compared with HFD group. In conclusion, compared with fish oil, perilla oil has similar but slightly weaker potency against HFD-induced NAFLD and gut dysbiosis.

Chemical biology applied to the study of bacterial pathogens.

In recent years, chemical biology and chemical genomics have been increasingly applied to the field of microbiology to uncover new potential therapeutics as well as to probe virulence mechanisms in pathogens. The approach offers some clear advantages, as identified compounds (i) can serve as a proof of principle for the applicability of drugs to specific targets; (ii) can serve as conditional effectors to explore the function of their targets in vitro and in vivo; (iii) can be used to modulate gene expression in otherwise genetically intractable organisms; and (iv) can be tailored to a narrow or broad range of bacteria. This review highlights recent examples from the literature to illustrate how the use of small molecules has advanced discovery of novel potential treatments and has been applied to explore biological mechanisms underlying pathogenicity. We also use these examples to discuss practical considerations that are key to establishing a screening or discovery program. Finally, we discuss the advantages and challenges of different approaches and the methods that are emerging to address these challenges.

Short-term inactivation rates of selected Gram-positive and Gram-negative bacteria attached to metal oxide mineral surfaces: role of solution and surface chemistry.

Metal oxides such as ferric or aluminum oxides can play an important role in the retention of bacteria in granular aquatic environments; however, their role in bacterial inactivation is not well understood. Herein, we examined the role of water chemistry and surface chemistry on the short-term inactivation rates of three bacteria when adhered to surfaces. To evaluate the role of water chemistry on the inactivation of attached bacteria, the loss in membrane integrity of bacteria attached to an iron oxide (Fe2O3) surface was measured over a range of water ionic strengths of either monovalent or divalent salts in the absence of a growth substrate. The influence of surface chemistry on the inactivation of attached bacteria was examined by measuring the loss in membrane integrity of cells attached to three surfaces (SiO2, Fe2O3, and Al2O3) at a specific water chemistry (10 mM KCl). Bacteria were allowed to attach onto the SiO2 or metal oxide coated slides mounted in a parallel-plate flow cell, and their inactivation rate (loss in membrane integrity) was measured directly without removing the cells from the surface and without disturbing the system. X-ray photoelectron spectroscopy analysis revealed a high correlation between the amounts of C-metal or O-metal bonds and the corresponding bacterial inactivation rates for each surface. Finally, for all three surfaces, a consistent increase in inactivation rate was observed with the type of bacterium in the order: Enterococcus faecalis, Escherichia coli O157:H7, and Escherichia coli D21f2.

Defense peptides from barnyard grass (Echinochloa crusgalli L.) seeds.

A number of defense polypeptides from latent seeds of weed cereal barnyard grass (Echinochloa crusgalli L.) has been isolated and characterized using an acidic extraction and high performance liquid chromatography methods in combination with MALDI-TOF mass spectrometry and Edman sequencing. Members of three antimicrobial peptide families and two protease inhibitor families were found to be localized in barnyard grass seeds. Their biological activity concerning to Gram-Positive and Gram-Negative phytopathogenic bacteria, as well as oomycete Phytophthora infestans, has been investigated. Diversity of barnyard grass defense peptides is a significant factor that provides a resistance of E. crusgalli seeds to germination and latent phases.

In vitro antibacterial potential of some Vitex species against human pathogenic bacteria.

OBJECTIVE: To study the antibacterial activity of the leaf methanol extracts of five different species of Vitex namely, Vitex altissima (V. altissima), Vitex diversifolia (V. diversifolia), Vitex negundo (V. negundo), Vitex peduncularis (V. peduncularis) and Vitex trifolia (V. trifolia). METHODS: Antibacterial assay was carried out by using disc diffusion method, determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) against five strains of Gram-positive and seven strains of Gram-negative human pathogenic bacterial strains. RESULTS: The results of antibacterial activity of Vitex species showed that the extracts possessed a broad spectrum of antibacterial activity. The V. peduncularis possessed the highest activity against all the microorganisms screened. It produced a zone of inhibition ranged between (11.000 ± 0.577) and (22.670 ± 0.667) mm and the MIC values were from 62.5 to 1 000.0 µg/mL and the MBC values were from 125.0 to 2 000.0 µg/mL. CONCLUSIONS: Based on the present study, V. peduncularis is recommended for the isolation of antibacterial molecule responsible for the activity against the tested human pathogenic bacterial strains.

Outcomes in severe sepsis and patients with septic shock: pathogen species and infection sites are not associated with mortality.

OBJECTIVES: We evaluated the respective influence of the causative pathogen and infection site on hospital mortality from severe sepsis related to community-, hospital-, and intensive care unit-acquired infections. DESIGN: We used a prospective observational cohort 10-yr database. We built a subdistribution hazards model with corrections for competing risks and adjustment for potential confounders including early appropriate antimicrobial therapy. SETTING: Twelve intensive care units. PATIENTS: We included 4,006 first episodes of acquisition-site-specific severe sepsis in 3,588 patients. INTEVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included 1562 community-acquired, 1432 hospital-acquired, and 1012 intensive care unit-acquired episodes of severe sepsis. After adjustment, we found no independent associations of the causative organism, multidrug resistance of the causative organism, infection site, or presence of bacteremia with mortality. Early appropriate antimicrobial therapy was consistently associated with better survival in the community-acquired (0.64 [0.51-0.8], p = .0001), hospital-acquired (0.72 [0.58-0.88], p = .0011), and intensive care unit-acquired (0.79 [0.64-0.97], p = .0272) groups. CONCLUSION: The infectious process may not exert as strong a prognostic effect when severity, organ dysfunction and, above all, appropriateness of early antimicrobials are taken into account. Our findings emphasize the importance of developing valid recommendations for early antimicrobial therapy.

The changing spectrum of neonatal infectious disease.

To understand the changing spectrum of neonatal infectious disease, one must first be familiar with the history, the variety of organisms and the progression of change of neonatal infections over the years. As progressively more immature neonates are surviving, the spectrum of infectious disease has changed in response to current medical practice responsible for this success and to selective pressures on the microorganisms. The surviving very low birth weight infants are at a significant risk for contracting infections from this expanding repertoire of pathogens. Microorganisms once thought seemingly benign and nonpathogenic are now commonly accepted as pathogens and are among the most likely organisms to cause infections in this extremely vulnerable patient population. When considering the possible identity of infecting organisms and attempting to tailor specific therapies to decrease unwanted consequences, one must consider the level of maturity and the age of neonate, as well as the intensity of care necessary for a successful outcome. This brief review focuses primarily on the changing spectrum of bacterial and fungal infections and will not substantially address viral infections.

Changing trends of in vitro antimicrobial resistance patterns in blood isolates in a tertiary care hospital over a period of 4 years.

CONTEXT: Multidrug-resistant organisms continue to be a problem for clinicians worldwide. AIMS: To analyze the changing trend of antimicrobial susceptibility patterns in the blood isolates over a period of 4 years in our hospital. SETTINGS AND DESIGN: This is a retrospective study done in tertiary care cardiac institute over a period of 4 years. MATERIALS AND METHODS: We retrospectively analyzed blood culture positive isolates and studied the antimicrobial susceptibility patterns of microorganisms during the period starting from January 2007 to December 2010. STATISTICAL ANALYSIS USED: Statistical analysis was conducted using SPSS for windows version 13.0. Fisher exact test or chi-square test was applied for comparison of categorical variables. P values less than .05 were considered as statistically significant. RESULTS: The rate of blood culture positivity was 3.72%. Gram-negative bacteria were more common than Gram-positive bacteria. There was a gradual increase in Gram-negative bacteria especially Klebsiella pneumoniae and Acinetobacter species. Klebsiella pneumoniae showed a significant increase of resistance to cefoperazone sulbactam (P = .023), piperacillin tazobactam (P < 0.001), imipenem (P < 0.001), and meropenem (P < 0.001) between the first (2007-2008) and second period (2009-2010) of study. The carbapenems resistance is on rise in Gram-negative bacteria including Enterobacteriaceae and non-fermenters. CONCLUSIONS: Our findings suggest that there is a definite increase in the multidrug resistant organisms. The data on the changing trends in antibiotic resistance, we believe is an important pillar in our efforts at improving infection control practices.

Assessment of the bacterial diversity of human colostrum and screening of staphylococcal and enterococcal populations for potential virulence factors.

In contrast to breast milk, little is known about the bacterial composition of human colostrum. The objective of this work was to analyze the bacterial diversity of colostrum obtained from healthy women and to characterize the dominant bacterial species for the presence of possible virulence factors. Samples of colostrum obtained from 36 healthy women were inoculated into different culture media. Several isolates from each medium were selected and identified. Staphylococcal and enterococcal isolates were submitted to genetic profiling. One representative of each profile was included in a genetic and phenotypic characterization scheme, including detection of potential virulence traits/genes and sensitivity to antibiotics. Staphylococcus epidermidis and Enterococcus faecalis were the dominant species, followed by Streptococcus mitis, Propionibacterium acnes and Staphylococcus lugdunensis. Among the 48 S. epidermidis isolates selected on the basis of their genetic profiles, the biofilm-related icaD gene and the mecA gene were detected in only 11 and six isolates, respectively. In parallel, 10 enterococcal isolates were also characterized and none of them contained the cylA, vanA, vanB, vanD, vanE and vanG genes. All of them were sensitive to vancomycin. There were no indications that the colostrum samples contained harmful bacteria.

Responses of a bacterial pathogen to phosphorus limitation of its aquatic invertebrate host.

Host nutrition is thought to affect the establishment, persistence, and severity of pathogenic infections. Nutrient-deficient foods possibly benefit pathogens by constraining host immune function or benefit hosts by limiting parasite growth and reproduction. However, the effects of poor elemental food quality on a host's susceptibility to infection and disease have received little study. Here we show that the bacterial microparasite Pasteuria ramosa is affected by the elemental nutrition of its aquatic invertebrate host, Daphnia magna. We found that high food carbon:phosphorus (C:P) ratios significantly reduced infection rates of Pasteuria in Daphnia and led to lower within-host pathogen multiplication. In addition, greater virulent effects of bacterial infection on host reproduction were found in Daphnia-consuming P-deficient food. Poor Daphnia elemental nutrition thus reduced the growth and reproduction of its bacterial parasite, Pasteuria. The effects of poor host nutrition on the pathogen were further evidenced by Pasteuria's greater inhibition of reproduction in P-limited Daphnia. Our results provide strong evidence that elemental food quality can significantly influence the incidence and intensity of infectious disease in invertebrate hosts.

Plasmodium berghei ookinetes induce nitric oxide production in Anopheles pseudopunctipennis midguts cultured in vitro.

The Anopheles pseudopunctipennis nitric oxide synthase gene (ApNOS) was identified and its partial sequence showed high homology with NOS from A. stephensi, A. gambiae (putative sequence), and Drosophila melanogaster. ApNOS was mainly expressed in male and female adult mosquitoes and was induced by a blood meal. Nitric oxide (NO) was produced by in vitro-cultured mosquito midguts inoculated by enema with Plasmodium berghei ookinetes, Saccharomyces cerevisiae, Gram-positive bacteria (Micrococcus luteus), but not with Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli or Serratia marcescens). Dihydroxyphenylalanine (L-DOPA) oxidation induced the generation of NO in midguts in vitro, and hydrogen peroxide generated during its oxidation induced ApNOS expression. P. berghei ookinetes exposed in vitro to L-DOPA and sodium nitroprusside (a NO generator) were killed. These observations demonstrate that reactive oxygen and nitrogen intermediates constitute a part of the cytotoxic arsenal employed by Anopheles mosquitoes against microbial pathogens and Plasmodium ookinetes.