MDRPA to MDSPA

In July 2011, I was so bummed to be admitted to the hospital with very, very few antibiotic options to treat my PA. Basically I had colistin and sorta kinda beta-lactams (intermediate resistance). Not too fun.

Well, thanks to the amazing wisdom of Ms. Mandy - who is always giving me great ideas), I have been taking Chilated Magnesium every day since October.

And in clinic on Jan 12, for the first time in 3 years, my clinic took me off isolation because I no longer have multi-drug resistant PA. Meaning all 3 of my PA strains are susceptible to nearly all classes of antibiotics (one strain is resistant to one class).

Talk about amazing. Incredible. Truly, a God-send.



Here are some studies supporting this outcome (thank you to Mandy's blog for these references):

Proteomic analysis of Pseudomonas aeruginosa grown under magnesium limitation.

Guina T, Wu M, Miller SI, Purvine SO, Yi EC, Eng J, Goodlett DR, Aebersold R, Ernst RK, Lee KA.

Department of Pediatrics, Division of Infectious Diseases, University of Washington, Seattle, Washington 98195, USA. tguina@u.washington.edu 

In this study, large-scale qualitative and quantitative proteomic technology was applied to the analysis of the opportunistic bacterial pathogen Pseudomonas aeruginosa grown under magnesium limitation, an environmental condition previously shown to induce expression of various virulence factors. For quantitative analysis, whole cell and membrane proteins were differentially labeled with isotope-coded affinity tag (ICAT) reagents and ICAT reagent-labeled peptides were separated by two-dimensional chromatography prior to analysis by electrospray ionization-tandem mass spectrometry (ESI-MS/MS) in an ion trap mass spectrometer (ITMS). To increase the number of protein identifications, gas-phase fractionation (GPF) in the m/z dimension was employed for analysis of ICAT peptides derived from whole cell extracts. The experiments confirmed expression of 1331 P. aeruginosa proteins of which 145 were differentially expressed upon limitation of magnesium. A number of conserved Gram-negative magnesium stress-response proteins involved in bacterial virulence were among the most abundant proteins induced in low magnesium. Comparative ICAT analysis of membrane versus whole cell protein indicated that growth of P. aeruginosa in low magnesium resulted in altered subcellular compartmentalization of large enzyme complexes such as ribosomes. This result was confirmed by 2-D PAGE analysis of P. aeruginosa outer membrane proteins. This study shows that large-scale quantitative proteomic technology can be successfully applied to the analysis of whole bacteria and to the discovery of functionally relevant biologic phenotypes. 

PMID: 12837596 [PubMed - indexed for MEDLINE] 

Effects of Ginseng on PA motility and biofilm formation.

FEMS Immunol Med Microbiol. 2011 Feb 8. doi: 10.1111/j.1574-695X.2011.00787.x. [Epub ahead of print]

Effects of Ginseng on Pseudomonas aeruginosa motility and biofilm formation.

Wu H, Lee B, Yang L, Wang H, Givskov M, Molin S, Høiby N, Song Z.

Department of Clinical Microbiology, Rigshospitalet, Copenhagen, DENMARK Department of Systems Biology, Technical University of Denmark, Lyngby, DENMARK Department of International health, Immunology and Microbiology, University of Copenhagen, Copenhagen, DENMARK ESCMID Study Group on Biofilms.

Abstract

Biofilm associated chronic Pseudomonas aeruginosa lung infections in patients with Cystic Fibrosis (CF) are virtually impossible to eradicate with antibiotics because biofilm growing bacteria are highly tolerant to antibiotics and host defence mechanisms. Previously we found that Ginseng treatments protected animal models from development of chronic lung infection by P. aeruginosa. In the present study, the effects of Ginseng on the formation of P. aeruginosa biofilms were further investigated in vitro and in vivo. Ginseng aqueous-extract at concentrations of 0.5-2.0% did not inhibit growth of P. aeruginosa, but significantly prevented P. aeruginosa from forming biofilm. Exposure to 0.5% Ginseng aqueous-extract for 24 h destroyed most of 7-day-old mature biofilms formed by both mucoid and non-mucoid P. aeruginosa strains. Ginseng treatment enhanced swimming and twitching motility, but reduced swarming of P. aeruginosa at concentrations as low as 0.25%. Oral administration of ginseng extracts in mice promoted phagocytosis of P. aeruginosa PAO1 by airway phagocytes, but did not affect phagocytosis of a PAO1-filM mutant. Our study suggests that Ginseng treatment may help to eradicate the biofilm associated chronic infections caused by P. aeruginosa.

© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

PMID: 21303421 [PubMed - as supplied by publisher]

New Method Attacks PA

New Method Attacks Bacterial Infections on Contact Lenses

ScienceDaily (Jan. 25, 2011) — Researchers at National Jewish Health and the University of Texas Southwestern Medical Center have discovered a new method to fight bacterial infections associated with contact lenses. The method may also have applications for bacterial infections associated with severe burns and cystic fibrosis. The results were published online January 18 in the journalInvestigative Ophthalmology and Visual Science.

"Infections by the bacteriaPseudomonas aeruginosa can cause severe scarring and vision loss when they spread to the cornea," said senior author Jerry Nick, MD, Associate Professor of Medicine at National Jewish Health. "By breaking apart a molecular scaffolding that encases the organisms and makes them more difficult to eradicate, we were able to significantly reduce bacterial infection of the cornea."

The eye normally fights infections through a variety of defense mechanisms including blinking of the eyes, which helps remove bacterial organisms from the surface of the eye. Contact lenses, however, inhibit the effectiveness of blinking eyelids.

Thus, bacteria can adhere to the surface of the contact lens that sits against the eye. If those bacteria infect the corneal surface they can destroy the delicate corneal cells, which can lead to scarring and vision loss. The condition is known as microbial keratitis, and affects about two to four lens wearers per 10,000 each year.

Eye infections can be treated with antibiotics. However, it can be difficult to eliminate the bacteria on the contact lenses, especially when they form a biofilm. A biofilm is a matrix that harbors and encases communities of the organisms, making them harder to eradicate.

The researchers confirmed earlier findings that cellular debris from immune cells fighting the infection actually provide the raw materials for the biofilm -- DNA, actin and histones. So, they used the enzyme DNAase together with negatively charged poly aspartic acid to break down the chemical bonds of these elements that support the biofilm.

This treatment reduced biofilms on the contact lenses by 79.2 percent. The same treatment reduced infection of the cornea in an animal model by 41 percent. There was no evidence of any harm caused by the treatments. (Abstract)

"These are very promising early results that point to potentially new methods for removing bacterial biofilms from contact lens surfaces, thereby reducing the risk of microbial keratitis, as well as the for the treatment of infections by Pseudomonas that are associated with cystic fibrosis and severe burns,' said Danielle Robertson, OD, PhD, first author and Assistant Professor of Ophthalmology at UT Southwestern, and first author on the study.

Garlic as an inhibitor of Pseudomonas aeruginosa quorum sensing in cystic fibrosis--a pilot randomized controlled trial.

Pediatr Pulmonol. 2010 Apr;45(4):356-62.

Garlic as an inhibitor of Pseudomonas aeruginosa quorum sensing in cystic fibrosis--a pilot randomized controlled trial.

Smyth AR, Cifelli PM, Ortori CA, Righetti K, Lewis S, Erskine P, Holland ED, Givskov M, Williams P, Cámara M, Barrett DA, Knox A.

Division of Child Health, University of Nottingham, Nottingham, UK. alan.smyth@nottingham.ac.uk

Pseudomonas aeruginosa forms biofilms in the cystic fibrosis lung. Quorum sensing (QS) controls biofilm maturation, immune evasion, antibiotic tolerance and virulence factor production. Garlic shows QS inhibitory activity in vitro and in animal models. We report the first clinical trial in man of a QS inhibitor.

We randomized 34 patients to garlic or olive oil capsules (both 656 mg daily). Clinical outcomes and safety bloods were measured at baseline and after 8 weeks treatment. In this exploratory study, analysis was per protocol. Eight patients withdrew, leaving 26 for analysis (13 garlic).

With placebo, there was a greater decline in mean (SD) percentage change from baseline FEV(1) [-3.6% (11.3)] than with garlic [-2.0% (12.3)]. This was not significant (mean difference = 1.6, 95% CI -12.7 to 15.9, P = 0.8). The mean (SD) increase in weight was greater with garlic [1.0% (2.0)] than with placebo [0.6% (2.0)]--non-significant (mean difference = 0.4%, 95% CI -1.3 to 2.0, P = 0.6).

The median (range) change in clinical score with garlic was -1 (-3 to 5) and 1 (-1 to 4) with placebo (negative score means improvement). This was non-significant [median difference = -1 (-3 to 0), P = 0.16]. In the garlic group, seven patients had IV antibiotics versus five placebo. There was a highly significant correlation between plasma and sputum measurements of the QS molecule 3-oxo-C12-HSL (Pearson correlation coefficient = 0.914, P = 0.004). At the end of treatment five patients in each group had abnormal liver function or triglycerides and five garlic patients (one placebo) reported minor adverse effects.

Garlic capsules were well tolerated. Although there was no significant effect of garlic compared to placebo in this pilot study, there was a suggestion of improvement with garlic which should be investigated in a larger trial.

PMID: 20306535 [PubMed - in process]

Two-pronged model could help foil tough cystic fibrosis infections

Two-pronged model could help foil tough cystic fibrosis infections

Hanover, NH--Dartmouth Medical School researchers have devised a novel approach for thwarting the relentless bacterial infections that thrive in the lungs of people with cystic fibrosis (CF), unlocking new possibilities against a tenacious and toxic hallmark of the common genetic disease.

Combining a mainstay antibiotic with drugs to deprive the bacteria of iron, which facilitates their persistent growth, appears to boost infection killing, they found.

Their research, reported in the American Journal of Respiratory Cell and Molecular Biology online and scheduled for publication, builds on the collaborative expertise of DMS microbiology and lung physiology labs studying cystic fibrosis infections.

Cystic fibrosis patients are plagued by infections of the bacteria Pseudomonas aeruginosa. Their mucous-clogged lungs are fertile incubators for the bacteria to breed and cluster in slimy communities called biofilms that become increasingly drug resistant and damaging. Tobramycin, the antibiotic routinely used against the microbes, can control, but not efficiently eliminate Pseudomonas established on CF airway cells.

Last year, the DMS researchers reported that it took far more tobramycin to destroy biofilm pockets than can be delivered to the lungs. Using a surrogate tissue culture system they created to simulate human airways, they determined that up to 10 times the maximum tobramycin dosage was needed. They were also studying iron overload in CF lungs. Airway cells with the CF gene mutation release more iron, and the bacteria depend on that iron to form their resilient biofilms, the investigators discovered.

Now, applying their findings to the clinical front, the team demonstrated that two agents already approved by the Federal Drug Administration to treat acute iron poisoning or overload can enhance the ability of tobramycin against Pseudomonas infection.

"The beauty is that we are mixing FDA-approved drugs-- antibiotics and iron chelators-- to potentiate the effect of tobramycin on biofilm formation," said lead author Dr. Sophie Moreau-Marquis, a research associate. "It's an exciting translational framework that opens the door to potentially treating CF patients, taking the novel model we developed from the lab hopefully to the clinic."

Co-authors of the study are DMS professors Dr. Bruce Stanton of physiology, who heads the laboratory where Moreau-Marquis works, and Dr. George O'Toole of microbiology and immunology.

The research combines two results: "We were first to show iron is definitive for biofilms forming on live human airway cells. And the highest concentration of tobramycin that can reach CF lungs is below what we've shown to be barely enough to eradicate biofilms on airway cells," Moreau-Marquis said.

The team used two FDA-approved iron chelators, deferoxamine and deferasirox, that can remove excess iron from the system by binding to the metal in a process called chelation. To mimic the clinical environment, they stuck to the maximum possible tobramycin dose of 1,000 micrograms per milliliter, mixed with a chelator.

The combination had a dramatic effect: it disrupted the mass of established and highly resistant bacteria in human airway cells by 90 percent and it also prevented formation of damaging biofilms. In contrast, neither an iron chelator nor tobramycin alone had such success.

"We built on the idea that if more iron helps bacteria to grow, maybe taking iron away will help kill them," said O'Toole. "The concept is to reformulate one of these iron chelators to be inhaled with tobramycin, which is already inhalable, to treat the bacteria locally in the lungs."

Still, the team found evidence that a chelator can get into lungs from the bloodstream. Using a permeable support in the lab, they mimicked giving tobramycin to the lung side and a chelator to the blood side and showed that the iron chelator is able to work its way through to lungs.

KaloBios' KB001 Antibody Shows Encouraging Safety And Activity In New Approach To Fighting Pseudomonas Infection In Cystic Fibrosis Patients

KaloBios' KB001 Antibody Shows Encouraging Safety And Activity In New Approach To Fighting Pseudomonas Infection In Cystic Fibrosis Patients


Article Date: 18 Oct 2009 - 0:00 PDT


Phase 1/2 clinical trial results with KB001, a Humaneered™, high-affinity antibody fragment under development by KaloBios Pharmaceuticals, Inc. in cystic fibrosis patients showed an acceptable safety profile as well as trends toward reducing tissue inflammation and clearance of the bacterium. Results of the multi-center, randomized, double-blind, single-dose, placebo-controlled study are being presented today at the North American Cystic Fibrosis Conference in Minneapolis, MN. KaloBios is developing KB001 for the treatment and/or prevention of Pseudomonas aeruginosa infections in both cystic fibrosis patients and intensive care patients on ventilation, for whom Pseudomonas-caused pneumonia is a major costly health care problem.

"KB001 is designed to fight Pseudomonas aeruginosa (Pa) by blocking a virulence mechanism (the Type Three Secretion System or TTSS) on the bacterium's external surface that enables Pa to perforate and kill white blood cells and epithelial cells, and trigger tissue-damaging inflammation," said Dr. Geoff Yarranton, Kalobios' chief scientific officer. "By blocking Pa's killing mechanism, KB001 is intended to reduce the inflammation and exacerbations that are associated with the damage done to the lungs by Pa, and potentially enable the patient's own immune system to effectively fight and clear the bacterium from sites of infection. This contrasts with antibiotics like tobramycin that directly kill Pa, but quickly lose effectiveness if the bacteria become resistant to the drug."

The Phase 1/2 study enrolled two cohorts of approximately 12 patients who were randomized at a 2:1 ratio to receive a single IV infusion of KB001 or placebo at either 3.0 mg/kg or 10 mg/kg. Patients were followed for eight weeks. Results showed KB001 to be safe and non-immunogenic. An analysis of exploratory endpoints showed that there was an encouraging anti-inflammatory impact as measured by dose-related reductions in inflammatory markers, including neutrophils, IL-8, elastase, MPO, macrophages, and IL-1. There was also a trend in reducing mucoid and total Pa burden at day 56.

"We are very pleased with these initial clinical results for KB001, which we believe support conducting larger randomized clinical trials to further evaluate KB001's safety and clinical benefits for patients with cystic fibrosis," said Tillman Pearce, KaloBios' chief medical officer. "KB001 is a highly novel approach to treating Pseudomonas and now has shown promising data in both ventilator-associated pneumonia patients and cystic fibrosis patients."

Pseudomonas infection is a major unmet medical need with strains found all over the world that are resistant to common antibiotics. KaloBios is actively seeking a partner to help move this program forward and to ultimately capture the potential market of over $500 million that would exist for a safe and effective anti-Pseudomonas therapy.

For more information about KB001, please visit the KaloBios website.

Source
KaloBios

NanoBio's Nanoemulsion Kills Drug-Resistant Bacteria Found In Cystic Fibrosis Patients

NanoBio's Nanoemulsion Kills Drug-Resistant Bacteria Found In Cystic Fibrosis Patients


NanoBio Corporation today announced compelling preclinical data for NB-401, a nebulized nanoemulsion-based agent that kills highly drug-resistant strains of bacteria commonly found in cystic fibrosis patients. Currently there are limited treatment options available that effectively address these resistant bacteria. The study results are being presented today at the 2009 Annual North American Cystic Fibrosis Conference (NACFC) in Minneapolis, Minn.

"Given that cystic fibrosis patients are susceptible to respiratory failure following repeated bacterial infections of the lung, there is a tremendous need to develop new treatments that can overcome drug-resistant bacteria," said James R. Baker, Jr., MD, NanoBio's CEO and founder. "In laboratory studies, NB-401 is a very potent killer against these difficult strains."

NB-401 has been shown to be highly efficacious in vitro against Pseudomonas aeruginosa, Burkholderia, Acinetobacter, Stenotrophomonas and other multidrug-resistant bacterial strains from cystic fibrosis (CF) patients, including colistin-resistant isolates of Burkholderia and Stenotrophomonas. In addition, the nanoemulsion is effective against organisms that are grown in biofilm and the sputum from CF patients. Resistance to the nanoemulsion is not anticipated based on its unique mechanism of action of interacting with the bacterial membrane and causing physical lysis of the organism.

These findings suggest that the use of NB-401 may have clinical benefit in treating CF patients. NanoBio has completed additional studies demonstrating that NB-401 can effectively be nebulized for the treatment of pulmonary infections. The company is currently conducting toxicity studies prior to advancing to clinical testing of NB-401 for the treatment of bacterial infections associated with cystic fibrosis.

Cystic fibrosis affects an estimated 30,000 individuals in the United States and a total of 70,000 people worldwide.

Trends in pathogens colonising the respiratory tract of adult patients with cystic fibrosis, 1985-2005.

J Cyst Fibros. 2009 Sep 7. [Epub ahead of print]

Trends in pathogens colonising the respiratory tract of adult patients with cystic fibrosis, 1985-2005.

Millar FA, Simmonds NJ, Hodson ME.

Adult Cystic Fibrosis Dept, NHLI/Imperial College and Royal Brompton Hospital, London, United Kingdom.

INTRODUCTION: The treatment of patients with CF has continued to evolve. We hypothesised that sputum microbiology may have changed as a result of this.

METHOD: Retrospective analysis of sputum microbiology from adult CF patients (1985 to 2005) using the Royal Brompton Hospital CF database.

RESULTS: Colonisation with Pseudomonas aeruginosa or Staphylococcus aureus between 1985 and 2005 remained stable (77 to 82%, p=0.159; 54 to 47%, p=0.108; respectively). Haemophilus influenzae (48 to 6%; p<0.001), Aspergillus species (18 to 9%; p=0.002) and Burkholderia cepacia complex (9 to 4%; p=0.041) prevalence decreased. Stenotrophomonas maltophilia and MRSA increased (1 to 4%, p=0.02; 1 to 6%, p=0.002, respectively).

CONCLUSION: P. aeruginosa colonisation has remained stable; there has been a decline in B. cepacia complex, H. influenzae and Aspergillus sp., and only a small increase in S. maltophilia and MRSA. Intensive antibiotic strategies have been employed, which, so far, have not resulted in clinically significant emergence of new pathogens.

Liposomal Tobramycin Receives Second Orphan Drug Designation Within Weeks

ZURICH, July 16 /PRNewswire/ -- An innovative treatment for infections of the respiratory tract in cystic fibrosis patients has received a second orphan drug designation in the US only weeks after a first designation was granted. The recent designation relates to Burkholderia cepacia pathogens that can cause lethal infections in cystic fibrosis patients. For Axentis Pharma AG of Zurich, Switzerland, both designations affirm the therapeutic potential of its product candidate Fluidosomes(TM)-tobramycin, whose unique microbiological profile sets it apart from other antibiotic formulations (including free tobramycin).

Axentis Pharma (Switzerland) announced today that the Office of Orphan Products Development of the US Food and Drug Administration (FDA) has granted a second orphan drug designation to its lead product candidate Fluidosomes(TM)-tobramycin. This drug is a liposomal formulation of tobramycin and an innovative treatment for infections of the respiratory tract in patients with cystic fibrosis. Only three months ago, the FDA granted Fluidosomes(TM)-tobramycin orphan drug designation for the treatment of pulmonary infections caused by Pseudomonas aeruginosa. The newly granted second designation relates to pulmonary infections caused by Burkholderia cepacia (B. cepacia) pathogens.

Despite stringent infection control practices, B. cepacia infections still occur in cystic fibrosis patients and can lead to fatal sepsis. The cell envelopes of these especially virulent bacteria are impermeable to most antibiotics, which makes them particularly difficult to treat. Due to its unique mode of action, which allows the antibiotics to penetrate into the bacteria, Fluidosomes(TM)-tobramycin could become a particularly effective treatment for B. cepacia infections.

Prof. Dr. Miguel A Valvano, MD, Medical Advisor to Axentis Pharma, comments on the development: "Burkholderia cepacia is almost always multi-resistant to antibiotics and this, in conjunction with the poor prognosis of patients with B. cepacia infection, makes the treatment of these patients exceedingly complex. Tobramycin is in principle an effective antibiotic. The drug is however rather ineffective due to the impermeability of B. cepacia's cell envelope. In addition, B. cepacia - just like many other pathogens - has developed mechanisms to eliminate antibiotics once they have entered the cell. Fluidosomes(TM)-tobramycin seems to overcome these limitations by packing tobramycin into liposomes, which, by allowing effective penetration of the antibiotic into the bacterial cell, completely changes the microbiological profile of this antibiotic. Hence, Fluidosomes(TM)-tobramycin could be a totally new antibiotic formulation that addresses microbiological needs that no other antibiotic can."

What exactly happens when Fluidosomes(TM)-tobramycin encounters the bacterium is still not entirely clear, but pre-clinical data indicate a novel mode of action. Dr. Helmut Brunar, CEO of Axentis Pharma explains: "Once at the site of infection, tobramycin-containing liposomes seem to fuse with the cell membrane of the pathogen. In this way, the entire load of tobramycin contained in the Fluidosomes(TM) is released into the bacterial cell. Additionally, our data indicate that bacterial rescue mechanisms that pump tobramycin out of the cell are inhibited by the fusion process. The efficient delivery and maximum release of tobramycin into the bacterial cell together with inhibition of the clearance mechanism indicate that Fluidosomes(TM)-tobramycin has a highly efficient therapeutic effect."

About Axentis Pharma AG (http://www.axentispharma.com)

Axentis Pharma is a respiratory specialty pharmaceutical company whose core competence is the combination of a fully patented, liposome-based drug delivery system with already established and well-characterized therapeutic agents. The company is using its platform delivery technology, named Fluidosomes(TM) technology, for the development of its lead product, an inhalable liposomal formulation of tobramycin. Axentis Pharma's lead product is designed to treat bacterial infections in the lungs.

About Fluidosomes(TM) technology

Axentis Pharma's Fluidosomes(TM) technology uses biocompatible lipids endogenous to the lung that are formulated into small liposomes. This nanocapsule platform offers wide-ranging potential for unmet medical needs, including chronic respiratory infections of the lung. In the case of Fluidosomes(TM)-tobramycin, the interaction between tobramycin and the microbial cell is triggered when the liposomes undergo a fusion process with the outer membrane of the bacterial cell wall. Tobramycin then penetrates into the inner cell compartment and triggers bacterial cell death.

   
   For further information, please contact:
   Dr. Helmut Brunar, Ph.D., CEO
   Axentis Pharma AG
   Limmatquai 138
   8001 Zurich, Switzerland
   T +41-44-202-7878
   E board@axentispharma.com
   W http://www.axentispharma.com

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Importance of DNase and alginate lyase for enhancing free and liposome encapsulated aminoglycoside activity against Pseudomonas aeruginosa

J Antimicrob Chemother. 2009 May 22.

Importance of DNase and alginate lyase for enhancing free and liposome encapsulated aminoglycoside activity against Pseudomonas aeruginosa.

Alipour M, Suntres ZE, Omri A.

The Novel Drug & Vaccine Delivery Systems Facility, Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada.

Objectives This study evaluated the potential of DNase, alginate lyase (AlgL) and N-acetylcysteine (NAC) in enhancing the in vitro bactericidal activity of conventional (free) and vesicle-entrapped (liposomal) gentamicin, amikacin and tobramycin.

Methods The MICs and biofilm eradication for two clinical isolates of Pseudomonas aeruginosa (a mucoid strain and a non-mucoid strain) were determined in the presence and absence of AlgL. The co-activity of aminoglycosides with DNase and/or AlgL against endogenous P. aeruginosa in cystic fibrosis (CF) sputum was also measured. The inhibitory effects of mucin in the presence and absence of the mucolytic agent NAC on aminoglycosidic activity were also examined.

Results The MIC values of the liposomal aminoglycosides were similar to or lower than those of free aminoglycosides. Biofilm formation increased the bactericidal concentrations of these drugs by 8- to 256-fold and treatment with AlgL improved killing of the mucoid strain. The activity of some aminoglycosides against the sputum was increased by the addition of DNase or AlgL (P <> 0.05). Tobramycin was the most effective aminoglycoside to reduce biofilms and sputum.

Conclusions Liposomal aminoglycosides do not fare better than conventional forms. The co-administration of DNase and AlgL is essential for enhanced activity in reducing biofilm growth and sputum bacterial counts. While mucin retards bactericidal activity, NAC does not improve aminoglycosidic activity.

Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions.

J Med Microbiol. 2009 Jun;58(Pt 6):765-73.

Related Articles

Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions.

O'May CY, Sanderson K, Roddam LF, Kirov SM, Reid DW.

1Menzies Research Institute, University of Tasmania Clinical School, 43 Collins Street, Hobart, Tasmania 7001, Australia.

The success of Pseudomonas aeruginosa in cystic fibrosis (CF) and other chronic infections is largely attributed to its ability to grow in antibiotic-resistant biofilm communities. This study investigated the effects of limiting iron levels as a strategy for preventing/disrupting P. aeruginosa biofilms. A range of synthetic and naturally occurring iron-chelating agents were examined. Biofilm development by P. aeruginosa strain PAO1 and CF sputum isolates from chronically infected individuals was significantly decreased by iron removal under aerobic atmospheres.

CF strains formed poor biofilms under anaerobic conditions. Strain PAO1 was also tested under anaerobic conditions. Biofilm formation by this model strain was almost totally prevented by several of the chelators tested. The ability of synthetic chelators to impair biofilm formation could be reversed by iron addition to cultures, providing evidence that these effective chelating compounds functioned by directly reducing availability of iron to P. aeruginosa. In contrast, the biological chelator lactoferrin demonstrated enhanced anti-biofilm effects as iron supplementation increased.

Hence biofilm inhibition by lactoferrin appeared to occur through more complex mechanisms to those of the synthetic chelators. Overall, our results demonstrate the importance of iron availability to biofilms and that iron chelators have potential as adjunct therapies for preventing biofilm development, especially under low oxygen conditions such as encountered in the chronically infected CF lung.

PMID: 19429753 [PubMed - in process]

The Denmark Way

Pediatr Pulmonol. 2009 May 5. [Epub ahead of print]

The Denmark Way is characterized by that country's practice of doing IV antibiotics for those CFer's with PA every 3 months, regardless of how they are feeling. Danish CFer's readily live into their 50's.... very different than the rest of the Western World.

Pseudomonas aeruginosa biofilms in the respiratory tract of cystic fibrosis patients.

Bjarnsholt T, Jensen PO, Fiandaca MJ, Pedersen J, Hansen CR, Andersen CB, Pressler T, Givskov M, Høiby N.

Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Denmark.

The present study was undertaken to investigate the appearance and location of Pseudomonas aeruginosa in the cystic fibrosis (CF) lung and in sputum. Samples include preserved tissues of CF patients who died due to chronic P. aeruginosa lung infection prior to the advent of intensive antibiotic therapy, explanted lungs from 3 intensively treated chronically P. aeruginosa infected CF patients and routine sputum from 77 chronically P. aeruginosa infected CF patients. All samples were investigated microscopically using hematoxylin-eosin (HE), Gram and alcian-blue stain, PNA FISH and immunofluorescence for alginate.Investigation of the preserved tissues revealed that prior to aggressive antibiotic therapy, P. aeruginosa infection and destruction of the CF lung correlated with the occurrence of mucoid (alginate) bacteria present in aggregating structures surrounded by pronounced polymorphonuclear-leukocyte (PMN) inflammation in the respiratory zone (9/9). Non-mucoid bacteria were not observed here, and rarely in the conductive zone (1/9). However, in the explanted lungs, the P. aeruginosa aggregates were also mucoid but in contrast to the autopsies, they were very rare in the respiratory zone but abundant in the sputum of the conductive zone (3/3), which also contained abundances of PMNs (3/3). Non-mucoid and planktonic P. aeruginosa were also observed here (3/3).In conclusion, the present intensive antibiotic therapy of chronic P. aeruginosa infections, at the Copenhagen CF Centre, seems to restrain but not eradicate the bacteria from the conductive zone, whereas the remaining healthy respiratory zone appears to be protected, for a long period, from massive biofilm infection. This strongly suggests that the conductive zone serves as a bacterial reservoir where the bacteria are organized in mucoid biofilms within the mucus, protected against antibiotics and host defenses. Pediatr Pulmonol. (c)2009 Wiley-Liss, Inc.

PMID: 19418571 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/19418571?dopt=Abstract

Eradication of early Pseudomonas infection in cystic fibrosis.

I'm sorry that I don't have the full article. Please contact your local library or CF office to see if they subscribe to this journal....

Chron Respir Dis. 2009;6(2):99-107.

Eradication of early Pseudomonas infection in cystic fibrosis.

Lee T.

Leeds Regional Paediatric Cystic Fibrosis Centre, Childrens' Day Hospital, St James's University Hospital, Leeds, UK . timlee@doctors.org.uk.

Chronic infection with the environmental bacterium Pseudomonas aeruginosa is associated with greater morbidity and mortality for people with cystic fibrosis. Strict infection control measures including segregation appear to reduce but not eliminate the risk of initial acquisition of the organism. There is now good evidence from randomized controlled trials that early eradication regimens consisting of anti-pseudomonal antibiotics are effective in clearing P. aeruginosa and delaying the development of chronic infection in the majority of subjects. These regimens are safe and cost-effective. Ensuring that such regimens are widely adopted is therefore of considerable importance to improving outcomes for people with cystic fibrosis. The most effective antibiotic regimen, and the effects of new nebulizer technologies and methods to improve concordance remain to be determined.

PMID: 19411571 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/pubmed/19411571?dopt=Abstract

Fosfomycin for the treatment of infections caused by multidrug-resistant non-fermenting Gram-negative bacilli

Falagas ME, Kastoris AC, Karageorgopoulos DE, Rafailidis PI.

Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece; Department of Medicine, Henry Dunant Hospital, Athens, Greece; Department of Medicine, Tufts University School of Medicine, Boston, MA, USA.

The treatment of multidrug-resistant (MDR), extensively drug-resistant or pandrug-resistant non-fermenting Gram-negative bacterial infections constitutes a challenge in an era of few new antibiotic choices. This mandates the re-evaluation of already existing antibiotics such as fosfomycin. We systematically reviewed the literature to assess the clinical and microbiological effectiveness of fosfomycin in the treatment of these infections by searching PubMed, Scopus and the Cochrane Library databases. In 23 microbiological studies identified, 1859 MDR non-fermenting Gram-negative bacterial isolates were examined. The susceptibility rate to fosfomycin of MDR Pseudomonas aeruginosa isolates was >/=90% and 50-90% in 7/19 and 4/19 relevant studies, respectively. Cumulatively, 511/1693 (30.2%) MDR P. aeruginosa isolates were susceptible to fosfomycin. Serotype O12 isolates exhibited greater susceptibility. Only 3/85 (3.5%) MDR Acinetobacter baumannii and 0/31 MDR Burkholderia spp. isolates were susceptible to fosfomycin. Variable criteria of susceptibility were used in the included studies. Fosfomycin was synergistic in combination with a beta-lactam, aminoglycoside or ciprofloxacin in 46/86 (53.5%) MDR P. aeruginosa isolates. One animal study found a good therapeutic effect of the combination fosfomycin/gentamicin against MDR P. aeruginosa endocarditis. In six clinical studies, 33 patients with MDR P. aeruginosa infections (mainly pulmonary exacerbations of cystic fibrosis) received fosfomycin (25/33 in combination with other antibiotics); 91% of the patients clinically improved. In conclusion, fosfomycin could have a role as a therapeutic option against MDR P. aeruginosa infections. Further research is needed to clarify the potential utility of this agent.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T7H-4W5M091-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=676d2b06ca06225a6d41063877624c63

Bugs, biofilms, and resistance in cystic fibrosis

Respir Care. 2009 May;54(5):628-40.

Bugs, biofilms, and resistance in cystic fibrosis.

Davies JC, Bilton D.

Department of Gene Therapy, Imperial College, Emmanuel Kaye Building, Manresa Road, London SW3 6NP, United Kingdom. j.c.davies@imperial.ac.uk.

Bacteria infect the respiratory tract early in the course of cystic fibrosis disease, often fail to be eradicated, and together with an aggressive host inflammatory response, are thought to be key players in the irreversible airway damage from which most patients ultimately die. Although incompletely understood, certain aspects of the cystic fibrosis airway itself appear to favor the development of chronic modes of survival, in particular biofilm formation; this and the development of antibiotic resistance following exposure to multiple antibiotic courses lead to chronic, persistent infection. In addition to the common cystic fibrosis pathogens, such as Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa, several newer species are becoming more common. Furthermore, new molecular techniques have led to the identification of multiple different organisms within respiratory secretions, many of which are not cultured with conventional tools. Future work should aim to develop clinically applicable methods to identify these and to determine which have the potential to impact pulmonary health. We outline the basic tenets of infection control and treatment.

*Full text should be up and running soon.....

Two-pronged Model Could Help Foil Tough Cystic Fibrosis Infections

ScienceDaily (Apr. 24, 2009) — Dartmouth Medical School researchers have devised a novel approach for thwarting the relentless bacterial infections that thrive in the lungs of people with cystic fibrosis (CF), unlocking new possibilities against a tenacious and toxic hallmark of the common genetic disease.

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Combining a mainstay antibiotic with drugs to deprive the bacteria of iron, which facilitates their persistent growth, appears to boost infection killing, they found.

Their research, reported in the American Journal of Respiratory Cell and Molecular Biology online and scheduled for publication, builds on the collaborative expertise of DMS microbiology and lung physiology labs studying cystic fibrosis infections.

Cystic fibrosis patients are plagued by infections of the bacteria Pseudomonas aeruginosa. Their mucous-clogged lungs are fertile incubators for the bacteria to breed and cluster in slimy communities called biofilms that become increasingly drug resistant and damaging. Tobramycin, the antibiotic routinely used against the microbes, can control, but not efficiently eliminate Pseudomonas established on CF airway cells.

Last year, the DMS researchers reported that it took far more tobramycin to destroy biofilm pockets than can be delivered to the lungs. Using a surrogate tissue culture system they created to simulate human airways, they determined that up to 10 times the maximum tobramycin dosage was needed. They were also studying iron overload in CF lungs. Airway cells with the CF gene mutation release more iron, and the bacteria depend on that iron to form their resilient biofilms, the investigators discovered.

Now, applying their findings to the clinical front, the team demonstrated that two agents already approved by the Federal Drug Administration to treat acute iron poisoning or overload can enhance the ability of tobramycin against Pseudomonas infection.

"The beauty is that we are mixing FDA-approved drugs-- antibiotics and iron chelators-- to potentiate the effect of tobramycin on biofilm formation," said lead author Dr. Sophie Moreau-Marquis, a research associate. "It's an exciting translational framework that opens the door to potentially treating CF patients, taking the novel model we developed from the lab hopefully to the clinic."

Co-authors of the study are DMS professors Dr. Bruce Stanton of physiology, who heads the laboratory where Moreau-Marquis works, and Dr. George O'Toole of microbiology and immunology.

The research combines two results: "We were first to show iron is definitive for biofilms forming on live human airway cells. And the highest concentration of tobramycin that can reach CF lungs is below what we've shown to be barely enough to eradicate biofilms on airway cells," Moreau-Marquis said.

The team used two FDA-approved iron chelators, deferoxamine and deferasirox, that can remove excess iron from the system by binding to the metal in a process called chelation. To mimic the clinical environment, they stuck to the maximum possible tobramycin dose of 1,000 micrograms per milliliter, mixed with a chelator.

The combination had a dramatic effect: it disrupted the mass of established and highly resistant bacteria in human airway cells by 90 percent and it also prevented formation of damaging biofilms. In contrast, neither an iron chelator nor tobramycin alone had such success.

"We built on the idea that if more iron helps bacteria to grow, maybe taking iron away will help kill them," said O'Toole. "The concept is to reformulate one of these iron chelators to be inhaled with tobramycin, which is already inhalable, to treat the bacteria locally in the lungs."

Still, the team found evidence that a chelator can get into lungs from the bloodstream. Using a permeable support in the lab, they mimicked giving tobramycin to the lung side and a chelator to the blood side and showed that the iron chelator is able to work its way through to lungs.

The researchers are working with the CF clinic at Dartmouth-Hitchcock Medical Center to develop clinical trials. Their study is part of Dartmouth's interdisciplinary Lung Biology and Cystic Fibrosis Research Development programs, and is supported by the National Institutes of Health and the Cystic Fibrosis Foundation.

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Journal reference:

1. Sophie Moreau-Marquis, George A O'Toole, and Bruce A Stanton. Tobramycin and FDA-approved Iron Chelators Eliminate P. aeruginosa Biofilms on Cystic Fibrosis Cells. American Journal of Respiratory Cell and Molecular Biology, 2009; DOI: 10.1165/rcmb.2008-0299OC

Cystic Fibrosis: Sugar On Bacteria Surface Serves As Base For Web Of Resistance

http://www.sciencedaily.com/releases/2009/04/090421120902.htm

A vaccine promotes enhanced clearance of nonmucoid Pseudomonas aeruginosa.

http://snipurl.com/fhlvj