Using prodigiosin against some gram-positive and gram-negative bacteria and Trypanosoma cruzi

BACKGROUND: This work aimed to explore the action of natural prodigiosin on both bacterial organisms and Trypanosoma cruzi cells. METHODS: Natural prodigiosin pigment was extracted and purified from cultures of Serratia marcescens. Two media, peanut broth and peptone glycerol broth, both recommended in the literature for prodigiosin production, were compared. The prodigiosin obtained was employed to explore its antimicrobial properties against both bacteria and Trypanosoma cruzi cells. RESULTS: Peanut broth yielded four times more prodigiosin. The prodigiosin showed remarkable activity (minimal inhibitory concentrations in the range of 2-8 µM for bacteria and half maximal inhibitory concentration of 0.6 µM for Trypanosoma cruzi). In fact, the prodigiosin concentration required to inhibit parasite growth was as low as 0.25 mg/l versus 4.9 mg/l of benznidazole required. Furthermore, atomic force microscopy revealed marked morphological alterations in treated epimastigote forms, although no pore-formation activity was detected in protein-free environments. CONCLUSIONS: This work demonstrates the potential usefulness of prodigiosin against some gram-positive and gram-negative bacteria and Trypanosoma cruzi although further studies must be done in order to assess its value as a candidate molecule

Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers

Aim: To visualize by atomic force microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. Material and methods: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by atomic force microscopy (AFM) and its surface roughness determined. Results: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. Conclusions: AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability

Determination of the spatiotemporal dependence of Pseudomonas aeruginosa biofilm viability after treatment with NLC-colistin

The emergence of colistin-resistant Pseudomonas aeruginosa in cystic fibrosis (CF) patients, particularly after long-term inhalation treatments, has been recently reported. Nanoencapsulation may enable preparations to overcome the limitations of conventional pharmaceutical forms. We have determined the time-dependent viability of P. aeruginosa biofilms treated with both free and nanoencapsulated colistin. We also examined the relationship between the optimal anti-biofilm activity of nanostructured lipid carrier (NLC)-colistin and the structural organization of the biofilm itself. The results showed the more rapid killing of P. aeruginosa bacterial biofilms by NLC-colistin than by free colistin. However, the two formulations did not differ in terms of the final percentages of living and dead cells, which were higher in the inner than in the outer layers of the treated biofilms. The effective anti-biofilm activity of NLC-colistin and its faster killing effect recommend further studies of its use over free colistin in the treatment of P. aeruginosa infections in CF patients

Diabetic foot infection in Spain

Introduction: The associated complications of diabetes mellitus significantly impair the quality of life of affected patients. The disease leads to a wide variety of complications; among them foot ulcers are common being the most frequent cause of hospitaliza- tion of diabetic patients. Moreover, foot ulcers predict disability, morbidity, and mortality in diabetic patients in addition to incurring considerable healthcare costs. We investigate the bacteria involved in diabetic foot ulcers infection and record the evolution and epi- demiological data of a group of patients. Materials and methods: The study population consisted of prospectively enrolled diabetic patients who attended two hospitals in Barcelona: one specializing in foot care (Hospital Podologic of the University of Barcelona) and the other a tertiary referral hospital (Hospital de Sant Pau). A comparison of microbiological results and their dependence on the sampling method (swab or punch) was done. Results: Diabetic Foot Syndrome was more prevalent in males than in females and more prevalent in patients with type 2 than type 1 diabetes. It becomes apparent that individuals living alone (singles, widowers and widows, etc.) tend to request medical assi- stance later or perhaps they take less attention to their feet, thus percentage of singles increased with the severity. Relatives and nur- sing care seem to play a relevant role in the evolution and prognosis of diabetic foot ulcers. Conclusion: Relatives and nursing care seem to play a crucial role in the evolution and prognosis of diabetic foot ulcers. Pseudomonas and Staphylococcus were the most frequent bacteria infecting ulcers. The use of ciprofloxacin should be discouraged since resistance accounted up to a 40%

Draft genome sequence of the bacterium Gordonia jacobaea, a new member of the Gordonia genus

Gordonia jacobaea was isolated and characterized in the Department of Microbiology, University of Santiago de Compostela, in 2000. Here we present the draft genome sequence of this species, which will improve our understanding of the diversity and the relation of the cell wall proteins of G. jacobaea with other mycolata

An overview of antimicrobial peptides and the latest advances in their development

INTRODUCTION: The recent dramatic increase in the incidence of antimicrobial resistance has been recognized by organizations such as the United Nations and World Health Organization as well as the governments of the USA and several European countries. A relatively new weapon in the fight against severe infections caused by multi-drug resistant bacteria is antimicrobial peptides (AMPs). These include colistin, currently regarded as the last line of antimicrobial therapy against multi-drug resistant microorganisms. Areas covered: Here, the authors provide an overview of the current research on AMPs. The focus is AMPs currently being developed for the treatment of recalcitrant bacterial infections, the synergies of AMPs and antibiotics, and the activity of AMPs against biofilm. This review also includes a brief introduction into the use of AMPs in infections caused by Mycobacterium, fungi, and parasites. Expert opinion: In research into new antimicrobials, AMPs are gaining increasing attention. While many are natural and are produced by a wide variety of organisms, others are being newly designed and chemically synthesized in the laboratory to achieve novel antimicrobial agents. The same strategy to fight infections in nature is thus being effectively exploited to safeguard human and animal health

Infection by Strongyloides stercoralis in immigrants with Chagas disease: evaluation of eosinophilia as screening method in primary care

Objectives: to evaluate co-infection of Strongyloides stercoralis and Trypanosoma cruzi and to assess eosinophilia as a screening test for the detection of S. stercoralis infection in patients with Chagas disease (CD). Methods: a retrospective diagnostic validation study was performed on serum samples from primary care patients diagnosed with CD in the southern Barcelona metropolitan area. All samples with eosinophilia (n = 87) and a random sample of non-eosinophilic sera (n = 180) were selected. Diagnosis of CD was based on positive serology by means of two tests: ORTHO® T. cruzi ELISA test, and BIO-FLASH® Chagas or Bioelisa CHAGAS. SCIMEDX ELISA STRONGY-96 was used to diagnose strongyloidiasis. Results: strongyloides stercoralis serology was positive in 15% of patients of whom 95% showed eosinophilia, vs. 21% of those with negative serology (P < 0.001), with differences in the mean eosinophil count (0.49 vs. 0.27 × 109 /l). Only 1.1% of patients with CD but without eosinophilia presented positive serology for S. stercoralis, whereas 44% of patients with CD and eosinophilia did (P < 0.001). Sensitivity and specificity values for eosinophilia were thus 95% and 79%, respectively. PPV was 42.5% and NPV, 98.9%. Conclusions: the prevalence of co-infection by T. cruzi and S. stercoralis is not negligible and has probably been underestimated for years in many areas, due to frequently subclinical infections. Therefore, serology seems mandatory for these patients and the use of eosinophilia as initial screening could facilitate the task, decreasing the number of analyses to be performed

Systemic antibiotic prophylaxis to reduce early implant failure: a systematic review and meta-analysis

Systemic antibiotics are routinely prescribed in implant procedures, but the lack of consensus causes large differences between clinicians regarding antibiotic prophylaxis regimens. The objectives of this systematic review are to assess the need to prescribe antibiotics to prevent early implant failure and find the most appropriate antibiotic prophylaxis regimen. The electronic search was conducted in PubMed/MEDLINE, Scielo and Cochrane Central Trials Database for randomized clinical trials of at least 3 months of follow-up. Eleven studies were included in the qualitative analysis. Antibiotics were found to statistically significantly reduce early implant failures (RR = 0.30, 95% CI: 0.19-0.47, p < 0.00001; heterogeneity I2 = 0%, p = 0.54). No differences were seen between preoperative or both pre- and postoperative antibiotic regimens (RR = 0.57, 95% CI: 0.21-1.55, p = 0.27; heterogeneity I2 = 0%, p = 0.37). A single preoperative antibiotic prophylaxis dose was found to be enough to significantly reduce early implant failures compared to no antibiotic (RR = 0.34, 95% CI: 0.21-0.53, p < 0.00001; heterogeneity I2 = 0%, p = 0.61). In conclusion, in healthy patients a single antibiotic prophylaxis dose is indicated to prevent early implant failure

Novel synthetic polymyxins kill Gram-positive bacteria

Background: Staphylococcus aureus, including 'superbug' MRSA, is a major cause of nosocomial infections. In the European Union, up to 171 200 new nosocomial MRSA infections are acquired annually, and in the USA S. aureus causes more deaths than HIV/AIDS and tuberculosis combined. MRSA is also the first group of pathogens that infect the pulmonary tract in young patients with cystic fibrosis. Objectives: We describe two newly developed and synthesized colistin (polymyxin E)-inspired molecules. Methods: A collection of several isolates of S. aureus [including MRSA and vancomycin-resistant S. aureus (VRSA)] was tested. To check the antimicrobial activity, we performed time-kill curves, growth curves, biofilm eradication, toxicity and isothermal titration calorimetry. Results: Both peptides showed high antimicrobial activities (MIC 4 mg/L) and low relative toxicities (selectivity index close to 23). Conclusions: Successful production of polymyxin-scaffold molecules active against S. aureus, both MRSA and VRSA, opens up new approaches to the treatment of these complicated infections

Toxins Secreted by Bacillus Isolated from Lung Adenocarcinomas Favor the Penetration of Toxic Substances

The aim was to explore the eventual role of bacteria in the induction of lung cancer by smoking habits. Viable bacteria closely related to the genus Bacillus were detected at high frequencies in lung-cancer biopsies. Similar, if not identical, microbes were isolated from cigarettes and in smog. Bacteria present in cigarettes could be transferred to a physiological solution via a "smoker" device that mimicked their potential transfer during smoking those bacteria produce exotoxins able to open transmembrane pores. These channels can be used as a way to penetrate cells of benzopyrenes and other toxic substances present in tobacco products. We hypothesize that Bacillaceae present in tobacco play a key role in the development of lung cancer