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

New Antibiotic Discovered in the Nose

German researchers analyzed germs that inhabit the human body and found that about 30 percent of people had Staphylococcus aureus bacteria in their noses, but 70 percent did not, the Associated Press reported.

Those without S. aureus have another type of bacteria -- Staphyloccus lugdunensis -- in the nose that produces an antibiotic that keeps S. aureus in check, according to the study published online in the journal Nature.

Lugdunin is an antibiotic compound, a thiazolidine-containing cyclic peptide. It was isolated in 2016 after Staphylococcus lugdunensis was identified as the species of bacteria from the human nose that suppressed growth of species of disease-causing bacteria in that part of the humanmicrobiome. 

Ludgunin is a non-ribosomally synthesized cyclic peptide that inhibits growth of Staphylococcus aureus strain. The lugdunin genes are located on a 30-kbp operon. The genes lugA, lugB, lugC, and lugD encode four non-ribosomal peptide synthases, which are preceded by a putative regulator gene lugR

The scientists isolated this antibiotic, which they call lugdunin, and found that it was effective in treating mice whose skin was infected with S. aureus, the AP reported.

Lugdunin may offer a new way to fight antibiotic-resistant staph bacteria, one of the superbugs that pose a major health threat worldwide. Tests of lugdunin in humans have yet to be conducted.

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

Cempra Completes NDA Submissions for Solithromycin in the Treatment of Community-Acquired Bacterial Pneumonia

Cempra, Inc.  , a clinical-stage pharmaceutical company focused on developing antibiotics to meet critical medical needs in the treatment of bacterial infectious diseases, announced the completion of its rolling submission of the New Drug Applications (NDA) for solithromycin to the U.S. Food and Drug Administration (FDA) for the treatment of community-acquired bacterial pneumonia (CABP). Based on the Qualified Infectious Disease Product (QIDP) designation by the FDA of solithromycin, Cempra has Priority Review and has been granted Fast Track for both the oral capsule and intravenous formulations for the treatment of CABP, which could result in an FDA decision on solithromycin's NDA within eight months, or by the end of 2016, based on the Prescription Drug User Fee Act (PDUFA) performance goals.

 Solithromycin

"Completion of the rolling submission of our first NDAs during Cempra's ten year anniversary year represents a major milestone for the company and a significant step toward our goal of developing antibiotics to meet the critical medical needs of patients in the treatment of bacterial infectious diseases," stated Prabhavathi Fernandes, Ph.D., president and chief executive officer of Cempra. "We believe the intravenous and capsule formulations will provide dosing flexibility that could lead to fewer hospital admissions, earlier discharge if admitted, and increased treatment of CABP on an outpatient basis. We are confident we have a strong data package for solithromycin."

"The management of CABP remains a challenge to healthcare professionals and I firmly believe that solithromycin has the potential to be a significant part of the treatment of this life threatening illness, given its published clinical efficacy and potential for multiple formulations," stated Thomas M. File, M.D., principal investigator for solithromycin clinical trials, Northeast Ohio Medical University. "Solithromycin's potency, spectrum of activity and tolerability could help to offset the rising problem of bacterial resistance, and it is gratifying to note that patients could be closer to benefiting from this potential new treatment."

The FDA has a 60-day filing review period to determine whether the NDAs are complete and acceptable for filing, and to confirm that Priority Review has been granted. Cempra expects to communicate the agency's decision regarding acceptance of the NDAs and its PDUFA date when it is known. Cempra's submissions in the EU remain on track for completion by the end of June 2016.

About Solithromycin

Solithromycin is a highly potent next-generation macrolide, the first fluoroketolide, which has potent activity against most macrolide-resistant strains. In vitro and in vivo studies have shown potent activity against S. pneumoniae as well as an extended spectrum of activity against CA-MRSA, streptococci, Haemophilus, enterococci, Mycobacterium avium and in animal models of malaria. It is also active against atypical bacteria, such as legionella, chlamydia, mycoplasma and ureaplasma, and against gonococci and other organisms that cause genitourinary tract infections. It is 8-16 times more potent than azithromycin against many bacteria and is active against azithromycin-resistant strains. Solithromycin's activity against resistant strains is driven by its ability to interact with three sites on the bacterial ribosome, compared to one for current macrolides. The binding to bacterial ribosomes and interaction with three ribosomal sites is expected to limit the development of bacterial resistance to solithromycin.

Allergan Receives FDA Approval of Teflaro (ceftaroline fosamil) for Pediatric Patients

Allergan plc, a leading global pharmaceutical company,  announced the U.S. Food and Drug Administration (FDA) has approved the company's supplemental New Drug Application (sNDA) for Teflaro (ceftaroline fosamil), granting new indications for pediatric patients 2 months of age to less than 18 years of age with acute bacterial skin and skin structure infections (ABSSSI), including infections caused by methicillin-resistant Staphylococcus aureus (MRSA), and community-acquired bacterial pneumonia (CABP) caused by Streptococcus pneumoniae and other designated susceptible bacteria.

"The impact of ABSSSI and CABP among children is significant, as these infections often require hospitalization and are met with limited pediatric treatment options, particularly as resistance increases among the pathogens that cause these infections," said David Nicholson, Chief R&D Officer, Allergan. "These new indications are yet another testament to our ongoing research and development in anti-infectives to address the evolving challenges of serious infections. Importantly, it allows us to educate physicians on the data they need to prescribe Teflaro to appropriate pediatric patients in need of an option that is safe and effective against some of the most difficult-to-treat pathogens in ABSSSI and CABP."

ABSSSI and CABP are common causes of healthcare visits and hospitalizations among children. Studies show more than 70,000 hospitalizations for ABSSSI occur among children per year – a rate that has more than doubled over the past 13 years.1 A study conducted by the Centers for Disease Control and Prevention (CDC) also found children younger than 5 years of age accounted for 70 percent of children hospitalized for community-acquired pneumonia.

These new indications were approved based on results from clinical studies evaluating TEFLARO in pediatric patients (2 months to less than 18 years of age), including one active-controlled study in ABSSSI and two active-controlled studies in CABP. In the ABSSSI active-controlled study, the efficacy and safety of Teflaro was compared with vancomycin or cefazolin (each with optional aztreonam). In the CABP studies, Teflaro was compared with ceftriaxone. Use of Teflaro in pediatric patients 2 months to less than 18 years of age is supported by evidence from adequate and well-controlled studies of Teflaro in adults, as well as additional pharmacokinetic and safety data from pediatric trials.

The primary objective of the pediatric ABSSSI and CABP studies was to evaluate the safety and tolerability of Teflaro. These studies were not powered for comparative inferential efficacy analysis, and no efficacy endpoints were identified as primary.

To evaluate the treatment effect of Teflaro in the ABSSSI pediatric trial, an analysis was conducted in 159 patients with ABSSSI in the Modified Intent-to-Treat (MITT) population. This analysis evaluated responder rates based on achieving both cessation of lesion spread and absence of fever on Study Day 3. Patients treated with Teflaro showed a higher response at Study Day 3 versus the comparator group, with clinical response achieved in 80.4 percent (86/107) of patients treated with Teflaro and 75 percent (39/52) of patients in the comparator group, with a treatment difference of 5.4 percent (95 percent Confidence Interval [CI] -7.8, 20.3). Clinical cure rates at the test of cure (TOC) visit (8 to 15 days after the end of therapy) for the ABSSSI pediatric trial were 94.4 percent (101/107) for patients treated with Teflaro and 86.5 percent (45/52) for the comparator, with a treatment difference of 7.9 (95 percent CI -1.2, 20.2).

To evaluate the treatment effect of Teflaro in the CABP trial submitted for this pediatric filing, an analysis was conducted in 143 patients with CABP in the MITT population. This analysis evaluated responder rates at Study Day 4 based on achieving improvement in at least two out of seven symptoms (cough, dyspnea, chest pain, sputum production, chills, feeling of warmth/feverish and exercise intolerance or lethargy), and worsening in none of these symptoms. The clinical response at Study Day 4 was 69.2 percent (74/107) for patients treated with Teflaro and 66.7 percent (24/36) for the comparator, with a treatment difference of 2.5 percent (95 percent CI -13.9, 20.9). Clinical cure rates at TOC were 87.9 percent (94/107) for patients treated with TEFLARO and 88.9 percent (32/36) for the comparator, with a treatment difference of -1.0 (95 percent CI -11.5, 14.1).

Results from the clinical studies in pediatric patients showed that Teflaro demonstrated a safety profile that was compatible with treatment of ABSSSI and CABP at the clinical dosages studied. The safety findings were similar to those seen in the adult studies, and no safety concerns were identified beyond those already known to be cephalosporin class effects.

Teflaro is the first and only cephalosporin indicated in adults and pediatric patients 2 months of age and older for the treatment of ABSSSI and CABP due to designated susceptible pathogens that can be administered by intravenous (IV) infusion in five minutes to one hour.

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.

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.

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)

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

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

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

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

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  

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

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 

Compound Anthracimycin, discovered at sea shows potency against anthrax

Fenical's team in the Scripps Center for Marine Biotechnology and Biomedicine, working in conjunction with San Diego-based Trius Therapeutics, used an analytical technique known as spectroscopy to decipher the unusual structure of a molecule from a microscopic species known as Streptomyces. Initial testing of the compound, which they named anthracimycin, revealed its potency as a killer of anthrax, the infectious disease often feared as a biological weapon, as well as MRSA.

"The real importance of this work is the fact that anthracimycin has a new and unique chemical structure," said Fenical, who added that the finding is a basic research discovery, which could lead to testing and development, and eventually a drug. "The discovery of truly new antibiotic compounds is quite rare. This discovery adds to many previous discoveries that show that marine bacteria are genetically and chemically unique."

The discovery provides the latest evidence that the oceans, and many of its unexplored regions, represent a vast resource for new materials that could one day treat a variety of diseases and illnesses. Fenical, a distinguished professor of oceanography and pharmaceutical science, helped found the field of marine biomedicine as a researcher at Scripps. He is a pioneer in discovering and identifying these novel compounds. His research has helped bring attention to the need for continued exploration of the ocean for science and society....

More at  https://scripps.ucsd.edu/news/13060

Ref : http://onlinelibrary.wiley.com/doi/10.1002/anie.201302749/abstract

Compound discovered at sea shows potency against anthrax

FDA Approves Vibativ for Hospitalized Patients with Bacterial Pneumonia

We know that, Telavancin (trade name Vibativ) is a bactericidal lipoglycopeptide for use in MRSA or other Gram-positive infections. Telavancin is a semi-synthetic derivative of vancomycin. The FDA approved the drug in September 2009 for complicated skin and skin structure infections (cSSSI)...

Now U.S. Food and Drug Administration today expanded the approved use of the antibiotic Vibativ (telavancin) to treat patients with hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by Staphylococcus aureus. Vibativ should be used for the treatment of HABP/VABP only when alternative treatments are not suitable...

FDA Approves Vibativ for Hospitalized Patients with Bacterial Pneumonia