New drug that combines methicillin with polymer BPEI can combat MRSA

A University of Oklahoma team of chemists has developed a new antibiotic formulation to fight the sometimes deadly staph infection  caused by methicillin-resistant  S. aureus or MRSA and other antibiotic-resistant infectious bacteria. The new drug to treat MRSA combines traditional Food and Drug Administration-approved antibiotics, such as methicillin, with the polymer BPEI.

Charles Rice, principal investigator and professor in the Department of Chemistry and Biochemistry, OU College of Arts and Sciences, with team members Robert Cichewicz and Daniel Glatzhofer, both OU chemistry professors, has been able to invigorate older drugs from the penicillin family by combining them with BPEI. While this new formulation requires FDA approval, the approach restores efficacy to obsolete antibiotics.

"The use of first-line antibiotics to kill MRSA or other infectious bacteria will improve patient outcomes and lower the economic burden,"  Rice said. "The discovery in our laboratory has made it possible to create an effective antibiotic that can reduce expensive hospitalization costs."

Leading up to the discovery, Rice was working in his laboratory when he discovered a way to neutralize the MRSA bacteria so that it is no longer resistant to methicillin. This method can be used to neutralize other infectious bacteria. The takeaway from these experiments is that any number of penicillin-type drugs combined with BPEI or related polymers could create a new first-line drug for treating infectious diseases and change how MRSA and other infectious bacteria are treated.

The Centers for Disease Control considers MRSA a serious threat to human health. MRSA infected 80,500 people in 2011 and nearly one in seven cases resulted in death. When MRSA colonies invade host tissue, they release toxins that cause tissue injury leading to patient morbidity. Until now, more costly and highly toxic antibiotics of last resort were used to treat MRSA. The new first-line combo drug developed at OU by Rice and his team has the potential to change how patients with MRSA are treated.

Ref : https://ou.edu/content/publicaffairs/archives/OUTeamDevelopsNewAntibioticFormulationtoFightMRSAandOtherAntibioticResistantBacteria.html

Natural product darwinolide may help combat fatal MRSA infection

A serious and sometimes fatal bacterial infection, known as methicillin-resistantStaphylococcus aureus (MRSA), may soon be beatable thanks to the efforts of University of South Florida scientists who have isolated and tested an extract from a sponge found in Antarctica. The sponge extract, known as Dendrilla membranosa, yields a new, natural product chemical which has shown in laboratory tests that it can eliminate more than 98 percent of MRSA cells. The research team has named the new chemical "darwinolide."

The study describing their methods and results was published this week in the American Chemical Society's journal Organic Letters.

While years ago the highly-resistant MRSA infection was particularly problematic in places such as hospitals and nursing homes, it has developed into an infection that can be found in commonly-used places such as gyms, locker rooms and schools.

"In recent years, MRSA has become resistant to vancomycin and threatens to take away our most valuable treatment option against staph infections," said study co-author and USF microbiologist Dr. Lindsey N. Shaw.

MRSA is unique in that it can cause infections in almost every niche of the human host, from skin infections, to pneumonia, to endocarditis, a serious infection of tissues lining the heart. Unfortunately, the pace of the pharmaceutical industry's efforts to find new antibiotics to replace those no longer effective has slowed in recent years, said Shaw.

Like many other bacterium, the MRSA bacteria forms a biofilm.

"Biofilms, formed by many pathogenic bacteria during infection, are a collection of cells coated in a variety of carbohydrates, proteins and DNA," said Shaw. "Up to 80 percent of all infections are caused by biofilms and are resistant to therapy. We desperately need new anti-biofilm agents to treat drug resistant bacterial infections like MRSA."

USF chemistry professor Dr. Bill Baker and colleagues have literally gone to the 'ends of the Earth' to help in the fight against MRSA. Baker, who also serves as director of the USF Center for Drug Discovery and Innovation (CDDI), studies the chemical ecology of Antarctica and dives in the frigid waters near Palmer Station to retrieve marine invertebrates, such as sponges, to carry out "natural product isolation," which means drawing out, modifying and testing natural substances that may have pharmaceutical potential.

His group led the effort to extract and characterize chemical structures to create darwinolide from the freeze-dried Antarctic sponges and then test in Shaw's lab to determine its effectiveness against the MRSA bacteria.

"When we screened darwinolide against MRSA we found that only 1.6 percent of the bacterium survived and grew. This suggests that darwinolide may be a good foundation for an urgently needed antibiotic effective against biofilms," said Baker, whose research team "rearranged" the chemical composition of the extracted sponge.

In the last 70 years, despite the discovery and use of antibiotics to treat infections, bacterial disease remains the second-leading cause of death globally, especially among children and the elderly, noted the researchers. In the U.S. alone there are two million hospital acquired infections annually with at least 100,000 deaths, many resulting from bacteria resistant to current antibiotics.

"We suggest that darwinolide may present a highly suitable scaffold for the development of urgently needed, novel, anti-biofilm-specific antibiotics," concluded the researchers.

Ref : http://pubs.acs.org/doi/abs/10.1021/acs.orglett.6b00979?journalCode=orlef7

Natural product darwinolide may help combat fatal MRSA infection: A serious and sometimes fatal bacterial infection, known as methicillin-resistant Staphylococcus aureus (MRSA), may soon be beatable thanks to the efforts of University of South Florida scientists who have isolated and tested an extract from a sponge found in Antarctica.

New experimental antibiotic can help combat MRSA infections

A new experimental antibiotic developed by a team of scientists at Rutgers University successfully treats the deadly MRSA infection and restores the efficacy of a commonly prescribed antibiotic that has become ineffective against MRSA.

In research published in the July issue of Antimicrobial Agents and Chemotherapy, Rutgers scientists say that the combination of their newly developed antibiotic, TXA709, with cefdinir, an antibiotic that has been on the market for almost two decades, successfully treated the MRSA infection in animals.

"This is important because even though TXA709 is effective on its own in treating MRSA, combining it with cefdinir - used to treat a wide range of bacterial infections like strep throat, pneumonia, bronchitis and middle ear and sinus infections - makes it even more efficacious, while also significantly reducing the potential for the MRSA bacteria to become resistant in the future," said Daniel Pilch, associate professor in the Department of Pharmacology at Robert Wood Johnson Medical School.

Pilch and fellow scientists are racing to develop a new class of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) infections, which are responsible for 19,000 deaths annually and represent $3 billion in annual health care costs.

The threat of MRSA and other antibiotic-resistant infections has become so severe that the World Health Organization predicts that common infections and minor injuries could become life-threatening because of a lack of drug treatments available to destroy these bacterial infections. Last month the first case in the United States of a patient with an infection resistant to all known antibiotics was reported by the U.S. Centers for Disease Control and Prevention.

"Current standard-of-care drugs for the treatment of MRSA infections are limited," said Pilch. "Furthermore, resistance to these drugs is on the rise, and their clinical effectiveness is likely to diminish in the future."

Pilch said that TXA709 kills MRSA bacteria in a unique manner unlike any other antibiotic in current clinical use, inhibiting the function of a protein, FtsZ, essential for the bacteria to divide and survive. By combining TXA709 with cefdinir, a cephalosporin antibiotic that acts much like penicillin, scientists were able to lower the dosage of the new antibiotic required to eradicate the MRSA infection.

This is significant, Rutgers scientists say, because it decreases the potential for any drug-induced toxicity and side effects that might occur from a higher dosage.

"What is also good about this experimental treatment is that both drugs can be taken orally, which means they can be administered on an outpatient basis," said Pilch, who collaborated with Edmond LaVoie, professor and chair of the Department of Medicinal Chemistry at the Ernest Mario School of Pharmacy at Rutgers. "All but two of the current antibiotics being used clinically to treat MRSA need to be administered intravenously," he said.

Researchers say Phase I clinical trials on the new antibiotic, which will assess and evaluate its safety and effectiveness in humans, are expected to begin next spring.

Ref : http://aac.asm.org/content/59/8/4845.full?sid=949e5603-f4b2-4eec-8e5f-f79d0c758e44

Two common antibiotic treatments equally effective against MRSA skin infections

Researchers funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, have found that two common antibiotic treatments work equally well against bacterial skin infections caused by methicillin-resistant Staphylococcus aureus (MRSA) acquired outside of hospital settings. Known as community-associated MRSA, or CA-MRSA, these skin infections have been reported in athletes, daycare-age children, students, military personnel and prison inmates, among others, and can lead to hospitalization, surgical procedures, bacteria in the blood, and in severe cases, death. 

Although MRSA is an increasingly common pathogen and the most common cause of skin infection in the United States, there is no standard treatment approach for CA-MRSA. As CA-MRSA emerged in community settings, there were concerns about how to identify the best treatment options and preserve the effectiveness of last-line drugs. Two older antibiotics that are no longer under patent, clindamycin and TMP-SMX, are recommended to treat CA-MRSA. It was unknown whether one antibiotic was associated with better outcomes in patients.

To answer this question, scientists tested clindamycin and TMP-SMX in adults and children with uncomplicated skin infections for 10 days. Of 466 study participants who received either antibiotic, the cure rate was 89.5 percent for clindamycin (below structure)

  

and 88.2 percent for TMP-SMX (Trimethoprim/sulfamethoxazole or co-trimoxazole) -(below structure)...

The side effects of both drugs were comparable. The findings, which appear in the New England Journal of Medicine, suggest that uncomplicated skin infectious acquired outside of hospitals can be treated inexpensively and successfully with either drug, according to the researchers.

Two common antibiotic treatments equally effective against MRSA skin infections

Novel class of antimicrobials could be effective in fighting drug-resistant MRSA infection

A novel class of antimicrobials that inhibits the function of a key disease-causing component of bacteria could be effective in fighting methicillin-resistant Staphylococcus aureus (MRSA), one of the major drug-resistant bacterial pathogens, according to researchers at Georgia State University.

Their study showed that small molecule analogs that target the functions of SecA, a central part of the general bacterial secretion system required for viability and virulence, have potent antimicrobial activities, reduce the secretion of toxins and can overcome the effect of efflux pumps, which are responsible for multi-drug resistance.

Their findings indicate that targeting SecA is an attractive antimicrobial strategy against MRSA and may be several times more effective than the antibiotics now available for treating the infection.

MRSA causes serious hospital and community-acquired infections. Healthcare-associated MRSA infections are typically linked to invasive procedures or devices, such as surgeries, intravenous tubing or artificial joints. Community-acquired MRSA often begins as a skin boil and is spread by skin-to-skin contact. Individuals at risk include competitive wrestlers, child care workers and those living in crowded conditions.

"We've found that SecA inhibitors are broad-spectrum antimicrobials and are very effective against strains of bacteria that are resistant to existing antibiotics," said Binghe Wang, Regents' Professor of Chemistry at Georgia State, Georgia Research Alliance Eminent Scholar in Drug Discovery and Georgia Cancer Coalition Distinguished Cancer Scholar. He co-led the study with Phang C. Tai, Regents' Professor of Biology at Georgia State, who is an expert on the functions of SecA in bacteria. Their findings were published in the journal Bioorganic & Medicinal Chemistry in November.

Novel class of antimicrobials could be effective in fighting drug-resistant MRSA infection

Innovative compound with anti-MRSA qualities may help develop new class of antibiotics

With global health services increasingly worried about the rise of antibiotic resistant diseases, researchers at Maynooth University have discovered a compound whose anti-MRSA qualities pave the way for the development of a new class of antibiotics. The new research is published today in the internationally renowned journalBioorganic and Medicinal Chemistry Letters. The findings mark the culmination of three years of work on the part of the team led by Dr John Stephens, Maynooth University Department of Chemistry, in collaboration with Dr Kevin Kavanagh, Maynooth University Department of Biology.

According to recent studies, on any given day one in 18 hospitalised patients are suffering from healthcare associated infections, with MRSA and E. coli responsible for 64% of cases. Doctors struggling with these infections are confronted with the increased prevalence of antibiotic resistant strains, but this represents only part of the problem. Of the antibiotics used today, almost all of them belong to classes discovered before the 1980s and this research was motivated by the urgent need to identify and synthesise new antibiotic classes.

Commenting on this discovery, Dr John Stephens observes:

As today’s infections develop increasing resistance to the antibiotics of the past, there is an urgent need for researchers to develop new therapeutics. Without this action, we are seriously at risk of entering a post-antibiotic world where common and traditionally minor infections could once again prove fatal. Discovering the antibacterial properties of our lead compound, the highly active quinoline thiourea, at Maynooth University is a significant first step. With further research and development, it has the potential to pave the way for a new class of antibiotic.

Ref : http://www.sciencedirect.com/science/article/pii/S0960894X15302663

Innovative compound with anti-MRSA qualities may help develop new class of antibiotics

Theravance Biopharma Announces FDA Approval of Expanded Label for Vibativ (telavancin)

In continuation of my update on telavancin

Theravance Biopharma, Inc. (NASDAQ: TBPH) ("Theravance Biopharma" or the "Company") today announced that the U.S. Food and Drug Administration (FDA) has approved the Company's supplemental New Drug Application (sNDA) for Vibativ (telavancin) to expand the product's label to include data describing the treatment of patients with concurrent Staphylococcus aureus (S. aureus) bacteremia in both of the antibiotic's currently approved indications in the United States. Vibativ is approved in the U.S. for the treatment of adult patients with hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by susceptible isolates of S. aureus when alternative treatments are not suitable. In addition, Vibativ is approved in the U.S. for the treatment of adult patients with complicated skin & skin structure infections (cSSSI) caused by susceptible isolates of Gram-positive bacteria, including S. aureus, both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains.

Bacteremia is the presence of bacteria in the bloodstream and can occur spontaneously or in the presence of other infections. Bacteremia continues to represent a significant unmet medical need. Concurrent bacteremia, which in its most serious form is fatal, occurs when bacteria spreads from its initial infection site and enters the bloodstream. As a secondary infection, it introduces significant challenges to the treatment of the primary infection, as well as the concurrent bacteremia itself.

"When patients with cSSSI or HABP/VABP present with concurrent bacteremia, their treatment becomes more difficult for healthcare practitioners. With this action by the FDA, we believe an important advance has been made in addressing the unique challenges in this area. The additional data that are now reflected in the Vibativ label address the use of Vibativ in cSSSI and HABP/VABP with concurrent bacteremia and we are now implementing a strategy to communicate this information to targeted healthcare practitioners," said Frank Pasqualone, Senior Vice President and Global Head, Acute Care Business at Theravance Biopharma. "With the broader medical need for effective bacteremia treatments in mind, we are also conducting a Phase 3 registrational study of telavancin in primary complicated S. aureus bacteremia, which we expect to complete in late 2017 or early 2018. Should we prove successful with this trial and secure approval in this infection type, Vibativ would possess the broadest set of indications of any branded anti-MRSA agent."

The sNDA filing was based on the combined data from Theravance Biopharma's previously conducted pivotal trials of Vibativ in its two approved indications -- cSSSI (ATLAS I and II) and HABP/VABP (ATTAIN I and II). The trials were large, multi-center, multinational, double-blind, randomized Phase 3 clinical studies enrolling and treating 3,370 adult patients, including a portion of patients with concurrent bacteremia. Importantly, these studies involved two of the largest cohorts of patients ever studied in these diseases and included one of the largest cohorts of patients with MRSA infections studied to date.

Expanded Vibativ Label Data

The data added to the Vibativ label describe patients with concurrent S. aureus bacteremia in the Phase 3 ATLAS and ATTAIN trials. These include:

• In the all-treated cSSSI patient population with baseline S. aureus bacteremia in the ATLAS I and II trials, clinical cure rates at test-of-cure were 57.1% for Vibativ-treated patients vs. 54.6% for vancomycin-treated patients.
• In the HABP/VABP patient population with at least one Gram-positive respiratory pathogen at baseline who had concurrent S. aureus bacteremia in the ATTAIN I and II trials, the 28-day all-cause mortality rate was 40.0% for Vibativ-treated patients vs. 39.5% for vancomycin-treated patients.

Separately, Theravance Biopharma is currently conducting a Phase 3 registrational study of telavancin in patients with complicated S. aureus bacteremia. The trial is a multi-center, randomized, open-label study that is enrolling approximately 250 adult patients with confirmed MSSA or MRSA bacteremia at about 70 clinical sites in the U.S. and around the world. Researchers are evaluating telavancin in treating these patients as compared to standard therapies such as vancomycin, daptomycin and anti-staphylococcal penicillins. The trial is expected to be completed in late 2017 or early 2018.

Scripps Research Institute Chemists Modify Antibiotic to Vanquish Resistant Bacteria

Scientists at The Scripps Research Institute (TSRI) have devised a new antibiotic based on vancomycin that is powerfully effective against vancomycin-resistant strains of MRSA and other disease-causing bacteria.

The new vancomycin analog appears to have not one but two distinct mechanisms of anti-microbial action, against which bacteria probably cannot evolve resistance quickly.

“This is the prototype of analogues that once introduced will still be in clinical use a generation or maybe even two generations from now,” said Dale L. Boger, the Richard and Alice Cramer Professor of Chemistry at TSRI.

The report by Boger and members of his laboratory was published recently online ahead of print by the Journal of the American Chemical Society.

Increasing Reports of Resistance

Vancomycin entered clinical use in 1958, five years after its isolation from microbes in a soil sample gathered by an American missionary in Borneo. For nearly six decades it has been useful against a wide range of bacteria, and it remains a standard weapon against methicillin-resistant Staphylococcus aureus (MRSA), a major cause of hospital-acquired infections. A compound closely related to vancomycin also has been widely used to protect livestock.

Since the late 1980s, there have been increasing reports of vancomycin resistance in classes of bacteria that usually succumb to the antibiotic, including MRSA. Although vancomycin remains useful, scientists have been looking for new drugs to replace it in cases—often life-threatening—where it no longer can help patients.

The Boger laboratory has focused on inventing improved versions of vancomycin rather than entirely new compounds. “Vancomycin has lasted in clinical use for more than 50 years, in part because it isn’t very vulnerable to antibiotic resistance,” Boger said. “Our thought has been that if we find a vancomycin analog that addresses this current source of resistance we’ll get another 50 years of use out of it.”

Vancomycin works by binding to the building blocks of bacterial cell walls, in a way that prevents their proper assembly and leaves bacteria too leaky to live and replicate. The resistance comes from a single amino-acid alteration that some bacteria make to those building blocks, so that the antibiotic molecule can no longer get a firm grip. That drops vancomycin’s potency by a factor of about 1,000.

‘Incredibly Potent’

In 2012, Boger and his team reported making a vancomycin analog—informally termed vancomycin amidine—with a subtly altered binding pocket that fastens about equally well to the original and resistant sites on bacterial cell wall subunits. To get the precise structural modification they needed, they had to come up with a method for the “total synthesis” of this vancomycin-based compound—a controlled, step-by-step construction using organic chemistry reactions in the lab, rather than a natural enzyme-mediated production within cells.

“Years of work in this lab culminated in a total synthesis strategy that not only allowed us access to this target compound, but also gave us the ability to perform almost any other chemical modification of vancomycin that we wished,” said Akinori Okano, first author of the new report, who is an assistant professor of chemistry at TSRI.

Vancomycin amidine turned out to have acceptable level of activity against vancomycin-resistant and -sensitive bacteria, yet there was room for improvement. Thus in the new study, Okano, Boger and their colleagues used their vancomycin synthesis methods to add an additional feature to the molecule—a peripheral chlorobiphenyl (CBP), long known as a general booster of vancomycin’s potency.

“To our delight, the combination of these modifications led to an incredibly potent molecule, well beyond anything we had expected,” said Okano.

Scripps Research Institute Chemists Modify Antibiotic to Vanquish Resistant Bacteria

White light-activated antibacterial coating-a new weapon against superbugs ?

I read in an article that infection costs the NHS around £1 billion per year and it is estimated that as many as 5,000 patients die each year in the UK as a direct result of an HCAI.

Cutting rates of healthcare associated infections (HCAIs) such as Methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (C.Diff) is a key priority for healthcare professionals. Recently in my earlier blog, I did mention that they were able to culture many bacterii from the cell phones of the health workers !.

Thogh govts., are taking many intiatives with sterlisation of the instrements, the rooms still something has to be done. But this is really something interesting which I read recently and want to share with...

Miss Zoie Aiken and her colleagues presented the work at the Society for General Microbiology meeting in Harrogate on 31 March, 2009. The veneer-like surface, made of titanium dioxide with added nitrogen. When it is activated by white light, similar to those used in hospital wards and operating theatres, it produced a decrease in the number of bacteria surviving on the test surface. Really interesting and the basis for this research is that "Titanium dioxide based coatings can kill bacteria after activation with UV light. The addition of nitrogen to these coatings enables photons available in visible light to be utilised to activate the surface and kill bacteria".

The following are the conclusions :

1. the activity of the coating is assessed against a range of different bacteria such as MRSA and other organisms which are known to cause infections in hospitals. At present researchers claim that the coating is active against Escherichia coli. However, E. coli is more difficult to kill than bacteria from the Staphylococcus group which includes MRSA and the results to date are encouraging.

2. the coating has currently been applied onto glass using a method called APCVD (atmospheric pressure chemical vapour deposition and the researchers want to try out plastic.

Once again congrats and best wishes for further research..

Source : http://www.sgm.ac.uk/

Scientists develop new drug as alternative to antibiotics

In a breakthrough, scientists have developed the first effective alternative to antibiotics that may aid the fight against drug-resistant infections. 

In a small patient trial, the drug was shown to be effective at eradicating the superbug Methicillin-resistant Staphylococcus aureus (MRSA). 

Researchers said it is unlikely that the infection could develop resistance against the new treatment, which is already available as a cream for skin infections. 

They hope to develop a pill or an injectable version of the drug within five years. 

The treatment marks "a new era in the fight against antibiotic-resistant bacteria," according to Mark Offerhaus, chief executive of the biotechnology company Micreos, which is behind the advance. 

The treatment attacks infections in an entirely different way from conventional drugs and, unlike them, exclusively targets the Staphylococcus bacteria responsible for MRSA, and leaves other microbes unaffected. 

The approach is inspired by naturally occurring viruses that attack bacteria using enzymes called endolysins. It uses a 'designer' endolysin, Staphefekt, which the scientists engineered to latch on to the surface of bacteria cells and tear them apart, 'The Times' reported. 

"Endolysins exist in nature, but we've made a modified version that combines the bit that is best at binding to the bacteria with another bit that is best at killing it," said Bjorn Herpers, a clinical microbiologist, who tested the drug at the Public Health Laboratory in Kennemerland, the Netherlands. 

Conventional antibiotics need to reach the inside of the cell to work, and part of the reason they are becoming less effective is that certain strains of bacteria, such as MRSA, have evolved impenetrable membranes. 

Scientists develop new drug as alternative to antibiotics  

2-aminoimidazole/triazole conjugate re-sensitizes multi-drug resistant strains of bacteria to the effects of conventional antibiotics...

We know that infections from antibiotic-resistant bacteria such as MRSA  are especially difficult to get rid of because the bacteria can attach to surfaces and then create biofilms, sticky layers of cells that act as a shield and prevent antibiotics from destroying the bacteria underneath. While a limited number of existing antibiotics may destroy part of the biofilm, enough bacteria survive to create a recurring infection as soon as antibiotic therapy stops, and over time the surviving bacteria build resistance to that antibiotic. Though I have covered some recent developments in the MRSA field, the following findings are  really interesting for me...

Now researchers lead by Dr. Christian Melander, from North Carolina State University have found that, 2-aminoimidazole/triazole conjugate will  re-sensitize multi-drug resistant strains of bacteria to the effects of conventional antibiotics (including MRSA and multi-drug resistant Acinetobacter baumannii), apart from the synergistic effect between  the  conjugate and antibiotics toward dispersing pre-established biofilms. 

Melander and his team, in collaboration with NC State biochemist John Cavanagh, found that pre-treating the bacteria with their compound and then introducing the antibiotic penicillin one hour later increased the penicillin's effectiveness 128-fold, even when the bacteria was penicillin resistant. The antibiotics also provided a 1,000-fold enhancement to the ability of the 2-aminoimidazole to disperse biofilms. 

Researchers conclude that, compound cooperates with conventional antibiotics, overcoming an infectious threat that would otherwise persist if treated with either agent individually.....

Ref : http://aac.asm.org/cgi/content/abstract/AAC.01418-09v1

Tamoxifen drug clears MRSA, reduces mortality

In continuation of my update on Tamoxifen

Researchers at University of California, San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences have found that the breast cancer drug tamoxifen gives white blood cells a boost, better enabling them to respond to, ensnare and kill bacteria in laboratory experiments. Tamoxifen treatment in mice also enhances clearance of the antibiotic-resistant bacterial pathogen MRSA and reduces mortality.

The study is published October 13 by Nature Communications.

"The threat of multidrug-resistant bacterial pathogens is growing, yet the pipeline of new antibiotics is drying up. We need to open the medicine cabinet and take a closer look at the potential infection-fighting properties of other drugs that we already know are safe for patients," said senior author Victor Nizet, MD, professor of pediatrics and pharmacy. "Through this approach, we discovered that tamoxifen has pharmacological properties that could aid the immune system in cases where a patient is immunocompromised or where traditional antibiotics have otherwise failed."

Tamoxifen targets the estrogen receptor, making it particularly effective against breast cancers that display the molecule abundantly. But some evidence suggests that tamoxifen has other cellular effects that contribute to its effectiveness, too. For example, tamoxifen influences the way cells produce fatty molecules, known as sphingolipids, independent of the estrogen receptor. Sphingolipids, and especially one in particular, ceramide, play a role in regulating the activities of white blood cells known as neutrophils.

"Tamoxifen's effect on ceramides led us to wonder if, when it is administered in patients, the drug would also affect neutrophil behavior," said first author Ross Corriden, PhD, project scientist in the UC San Diego School of Medicine Department of Pharmacology.

To test their theory, the researchers incubated human neutrophils with tamoxifen. Compared to untreated neutrophils, they found that tamoxifen-treated neutrophils were better at moving toward and phagocytosing, or engulfing, bacteria. Tamoxifen-treated neutrophils also produced approximately three-fold more neutrophil extracellular traps (NETs), a mesh of DNA, antimicrobial peptides, enzymes and other proteins that neutrophils spew out to ensnare and kill pathogens. Treating neutrophils with other molecules that target the estrogen receptor had no effect, suggesting that tamoxifen enhances NET production in a way unrelated to the estrogen receptor. Further studies linked the tamoxifen effect to its ability to influence neutrophil ceramide levels.

Ref : http://www.nature.com/ncomms/2015/151013/ncomms9369/full/ncomms9369.html

Tamoxifen drug clears MRSA, reduces mortality

FDA Approves Kimyrsa (oritavancin) for the Treatment of Adult Patients with Acute Bacterial Skin and Skin Structure Infections (ABSSSI)

Melinta Therapeutics, LLC (Melinta), a commercial-stage company focused on the development and commercialization of novel antibiotics, today announced that the U.S. Food and Drug Administration (FDA) has approved Kimyrsa (oritavancin)  for the treatment of adult patients with acute bacterial skin and skin structure infections (ABSSSI) caused by susceptible isolates of designated Gram-positive microorganisms, including methicillin-resistant Staphylococcus aureus (MRSA). Kimyrsa is a lipoglycopeptide antibiotic that delivers a complete course of therapy for ABSSSI in a single, one hour 1,200 mg infusion.

“The approval of Kimyrsa demonstrates Melinta’s commitment to provide innovative therapies to patients with acute and life-threatening illnesses,” said Christine Ann Miller, President and Chief Executive Officer of Melinta. “We have responded to the requests of the medical community to provide an oritavancin product with a shorter infusion time.  We believe that with the approval of Kimyrsa and product availability this summer, physicians and patients will now have a compelling new one-dose alternative to the current standard of multi-dose regimens for ABSSSI.”

ABSSSI affect approximately 14 million patients in the U.S. each year, are responsible for over 3 million visits to the Emergency Room annually and represent the 8th most common cause of Emergency Department hospital admissions1,2. ABSSSI cost U.S. hospitals $4 billion each year, with a 4.1-day average length of stay for hospitalized ABSSSI patients.2

“Kimyrsa is an important new treatment option that will provide clinicians with additional flexibility to treat ABSSSI patients in multiple care settings, without the need for hospitalization,” said Andrew Dold, D.O., member of a private infectious disease practice covering the Greater Atlanta Region. “Single-dose, long-acting antibiotics, such as Kimyrsa, may be especially beneficial for patients who lack the support or resources to adhere to multiple intravenous administrations.”

The efficacy and safety of Kimyrsa were established in the SOLO clinical trials with another oritavancin product, Orbactiv. The SOLO trials were randomized, double-blind, multicenter studies that evaluated a single 1,200 mg IV dose of oritavancin against twice-daily vancomycin for the treatment of ABSSSI in 1,987 adult patients and assessed one of the largest subsets of documented MRSA infection (405 patients). These trials demonstrated that 1,200 mg one-dose IV oritavancin infusion was as effective as 7-to-10 days of twice-daily vancomycin (1 g or 15 mg/kg) for the primary and secondary endpoints.  Kimyrsa approval is based on the results of an open-label, multi-center, pharmacokinetics study, which compared Kimyrsa administered over 1 hour (N=50) to Orbactiv administered over 3 hours (N=52) for the treatment of adult patients with ABSSSI.

Michael Waters, M.D. and lead investigator in the PK clinical trial stated, “Kimyrsa was shown to be comparable to Orbactiv with a favorable safety profile.  I’m pleased that these outcomes support the approval of Kimyrsa to provide oritavancin with a shorter infusion time and lower infusion volume.  With these features, Kimyrsa can further enhance the treatment experience for the patient and efficiency of administration in clinical practice.”

https://en.wikipedia.org/wiki/Oritavancin

Linezolid more effective than vancomycin in treating ventilated patients with MRSA pneumonia: Study

In continuation of my update on Linezolid and Vancomycin...

Linezolid more effective than vancomycin in treating ventilated patients with MRSA pneumonia: Study

Lytix Biopharma receives approval to initiate Phase I/IIa clinical trial of Lytixar for MRSA

Lytix Biopharma receives approval to initiate Phase I/IIa clinical trial of Lytixar for MRSA 

New Antibiotic May Treat Skin Infections in Shorter Time - Drugs.com MedNews

Torezolid (also known as TR-701 and now tedizoli) is an oxazolidinone drug being developed by Trius Therapeutics(originator Dong-A Pharmaceuticals) for complicated skin and skin-structure infections (cSSSI), including those caused by Methicillin-resistant Staphylococcus aureus (MRSA). 

New Antibiotic May Treat Skin Infections in Shorter Time - Drugs.com MedNews

Plectasin - a new weapon against highly resistant microbes ?..

We know that Plectasin, found in Pseudoplectania nigrella (see picture), is the first defensin to  be isolated from a fungus. Plectasin has a chemical structure resembling defensins found in spiders, scorpions, dragonflies and mussels. In laboratory tests, Plectasin was especially active in inhibiting the growth of the common human pathogen Streptococcus pneumoniae, including strains resistant to conventional antibiotics. Plectasin has a low toxicity in mice, and cured them of peritonitis and pneumonia caused by S. pneumoniae as efficiently as vancomycin and penicillin, suggesting that it may have therapeutic potentia.

Now researchers lead by Prof. Dr. Hans-Georg Sahl of   Universities of Bonn, Utrecht, Aalborg and of the Danish company Novozymes AS have shed light on how the substance Plectasin,  destroy highly resistant bacteria. As per the claim by the researchers Plectasin binds to a cell-wall building block called lipid II and thus prevents it from being incorporated and thus disrupting the forming of the cell wall in bacteria so that the pathogens can no longer divide. 

In this process, plectasin behaves like a thief which steals the stones off a mason. 'It binds to a cell-wall building block called lipid II and thus prevents it from being incorporated ,' Professor Sahl explains. 'However, bacteria cannot live without a cell wall.' It comes as no surprise that the most famous antibiotic penicillin also inhibits cell-wall synthesis...

Researchers claims that, plectasin is more similar in its mode of action to another widely used drug, vancomycin. Vancomycin had been the drug of choice in combating MRSA strains since the 1980s. Meanwhile, though, there are more and more bacteria that are also resistant to vancomycin. 'However, these strains are still susceptible to plectasin,' Dr. Tanja Schneider emphasises. Nevertheless, there is no permanent solution to the resistance problem even with a new antibiotic . 'It is always just a question of time until the pathogens mutate and become insensitive ,' she says. 'It's a never ending arms race..' authors conclude that plectasin will be promising lead compound for new antibiotics...

Ref : http://www.sciencemag.org/cgi/content/abstract/328/5982/1168

Promising discovery in fight against antibiotic-resistant bacteria .....

Researchers at  the  University  of British  Columbia  have identified a small molecule  that prevents  bacteria from forming into biofilms, a frequent cause of infections. The anti-biofilm peptide works on a range of bacteria including many that cannot be treated by antibiotics...

Hancock and his colleagues found that the peptide known as 1018  consisting of just 12 amino acids, the building blocks of protein  destroyed biofilms and prevented them from forming.

Bacteria are generally separated into two classes, Gram-positives and Gram-negatives, and the differences in their cell wall structures make them susceptible to different antibiotics. 1018 worked on both classes of bacteria as well as several major antibiotic-resistant pathogens, including Pseudomonas aeruginosa, E. coli and MRSA.

"Antibiotics are the most successful medicine on the planet. The lack of effective antibiotics would lead to profound difficulties with major surgeries, some chemotherapy treatments, transplants, and even minor injuries," says Hancock. "Our strategy represents a significant advance in the search for new agents that specifically target bacterial biofilms."

Promising discovery in fight against antibiotic-resistant bacteria 

Allergan Announces FDA Approval of Updated Label for New Dosing Regimen for Dalvance (dalbavancin)

In continuation of my update on Dalbavancin

Allergan plc (NYSE: AGN), a leading global pharmaceutical company, today announced the U.S. Food and Drug Administration (FDA) has approved the company's supplemental new drug application (sNDA) to update the label for Dalvance (dalbavancin) for injection. The expanded label will include a single dose administered as a 30-minute intravenous (IV) infusion of Dalvance for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by designated susceptible Gram-positive bacteria in adults, including infections caused by methicillin-resistant Staphylococcus aureus (MRSA).

Allergan Announces FDA Approval of Updated Label for New Dosing Regimen for Dalvance (dalbavancin)

MSRA can be stopped before it becomes dangerous ....

In continuation of my update on MRSA (methicillin-resistant Staphylococcus aureus), I found the following info interesting.

C. Jeffrey Brinker research group has determined that the very first stage of staph infection, when bacteria switch from a harmless to a virulent form, occurs in a single cell and that this individual process can be stopped by the application of a simple protein (as against the belief that, staph infections are caused by many bacterial cells that signal each other to emit toxins. The signaling process is called quorum sensing). The most significant results from the researchers are :

1. isolation of Staphylococcus aureus bacteria in individual (isolation of an individual bacterium
previously had been achieved only computationally);

2. demonstration of release of signaling peptides from a single cell, not a quorum &

3. introduction of an inexpensive, very low-density lipoprotein (VLDL) to bind to the
messenger peptide, they stopped the single cell from reprogramming itself.

One aspect of experimental rigor was the team's ability to organize living cells into a nanostructured matrix. The researchers has already done it with yeast, and just extended the process to bacteria. Researchers are optimistic about finding a mechanism to locate bacteria reprogramming in the body so that the antidote can be delivered in time. If they achieve what they are optimistic, so there will selectivity of targeting the bacteria (human gastro-intestinal system contains many useful bacteria) which in my opinion will be a remarkable feat....

Ref : http://www.nature.com/nchembio/journal/vaop/ncurrent/full/nchembio.264.html