High blood pressure, or hypertension, affects approximately 1.28 billion adults (ages 30-79) globally. (1) This condition increases the risk of severe health issues, including heart attacks, heart failure, aneurysms, strokes, and other serious health conditions. While lifestyle adjustments and medications can mitigate these risks, many individuals with hypertension may not be aware they are affected.

Research suggests that the gut, once viewed primarily for food digestion, may be a central player in cardiovascular well-being. So, could probiotics be used to reduce high blood pressure?

______________________________

Two probiotics were found to

significantly lower blood pressure!

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Previous studies show that imbalances of gut microbiota are correlated with an increased risk of hypertension. (2) Studies also indicated that probiotics might provide antihypertensive, or blood pressure reducing, effects. (3) Although we do not fully understand the precise mechanisms by which the gut microbiota influences blood pressure, a recent study provided promising data on the effects of Bifidobacterium lactis and Lactobacillus rhamnosus.

Researchers monitored hypertensive mice for alterations in the animals' gut microbial composition over a 16-week period. They pinpointed specific microbes and metabolic pathways that could cause an observable protective effect. (4) Mice subjected to a high-fructose diet and treated with either Bifidobacterium lactis or Lactobacillus rhamnosus exhibited significantly lower blood pressures compared to their counterparts who were solely on a high fructose regimen without probiotic intervention. In fact, the diastolic pressure was reduced by over 20%.

There were no discernible differences in blood pressure readings between fructose-fed mice receiving these probiotics and a control group consuming only water, indicating that the probiotics were effective with a high carbohydrate diet. The probiotics induced changes in the gut microbiome composition, favoring bacteria associated with lower blood pressure and decreasing those linked to higher blood pressure. (4) This may indicate probiotic interventions could help reduce high blood pressure levels and maintain them.

Despite promising results, additional trials are needed to further explore the role of these probiotics in human cardiovascular health. While researchers continue to investigate the link between the gut and the heart, perhaps consider adding more probiotic-rich foods, such as yogurt, kefir, and fermented vegetables to your diet. Once again, we discover the importance of a healthy and diverse microbiome that helps us maintain optimal health.

By Lauren Hamilton

Lead Performance Studies Microbiologist, Hardy Diagnostics

References: 1, 2, 3, 4

Clostridial gas gangrene (CGG) is an unusual but fast-spreading necrotic infection of soft tissue resulting in high mortality rates. Though rare, a 2020 case report published in Frontiers in Surgery shares the complete timeline of a 65-year old male patient who after laparoscopic rectal cancer surgery died following a necrotizing fasciitis infection.

Postoperative infections are one of the most common complications in general surgery, and rates have been reduced with the routine administration of perioperative antibiotics (1). CGG is reportedly more common after penetrating trauma or major surgery and is rarely reported without obvious predisposing events, such as edema, fever, malaise, and pain. Previous documents have only once reported Gas Gangrene after an open rectal surgery of laparoscopic

cholecystectomy (2, 3). However, the authors of the case documented in the Frontiers in Surgery report say this is the first time CGG of the pelvic wall, after laparoscopic resection for rectal cancer occurred.

Twenty-four hours after surgery, the patient started complaining of incisional pain in his lower abdomen. The following night the patient’s pain intensified and his condition continued to deteriorate. The patient was transferred to the intensive care unit where his healthcare team administered antibiotic therapy with meropenem, provided IV fluids, and high-oxygen flow treatments. Unfortunately, 10 hours later, just two days post-op, he went into septic shock and he was declared deceased.  

The CGG diagnosis in this patient was difficult due to a number of reasons including very acute onset, rapid progression of symptoms, limited time and underlying health issues. Ultimately, discharge from the patient’s incision was examined by the microbiologist where plentiful infiltrated leucocytes and large Gram-positive bacilli were discovered. The microbiologist concluded that the Gram-positive bacilli were most likely an anaerobe that was cultivated on an anaerobic medium. The health care team also sent peripheral blood samples to perform next-generation sequencing (NGS) to specify the kind of bacilli and it was then that the peripheral blood sample confirmed the diagnosis of CGG.

The gold standard of diagnosis of CGG is a frozen-section biopsy. According to the authors of the 2022 report, anaerobic culture of tissue or discharge is of “great diagnostic value, especially when necrotizing fasciitis or CGG is suspected.” 

Hardy Diagnostics offers a pre-reduced anaerobic media in oxygen flushed pouches called AnaeroGRO. Read more about AnaeroGRO and related anaerobic media on our website.  See Hardy's complete Anaerobic Bacteriology catalog here.

By Megan Roesner, Clinical Microbiology Product Manager

References: 1, 2, 3

The Debate Continues...

Do masks work?

In last month's MicroBytes edition we asked our readers to comment on the effectivity of mask wearing. Many of our readers offered their opinions. See a selection of those comments HERE.

New Therapies for Difficult-to-Treat Pathogens:

Sulbactam-Durlobactam

and Rezafungin

Healthcare professionals face a constant challenge with ever-evolving bacterial and fungal infections. Multidrug-resistant pathogens threaten the efficacy of existing treatments and highlight the need for new antimicrobial therapies. These microorganisms are typically resistant to the majority of antimicrobial agents, including carbapenems, making them difficult to treat. The Centers for Disease Control and Prevention (CDC) has identified carbapenem-resistant Acinetobacter baumannii (CRAB) as an urgent public health threat.

Sulbactam-Durlobactam (Xacduro) was FDA approved in May to treat hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP) caused by Acinetobacter baumannii-calcoaceticus complex. HardyDisk™ AST Sulbactam-Durlobactam was subsequently FDA cleared 44 days later. The intravenous drug developed by Entasis Therapeutics Inc., provides a promising solution to treatment of CRAB.

Rezafungin (Rezzayo) is a new antifungal agent that gained FDA approval in March. HardyDisk™ AST Rezafungin was subsequently FDA cleared 71 days later. Cidara Therapeutics developed this echinocandin antifungal agent to combat invasive fungal infections. This marks the first new treatment option approved for individuals with candidemia and invasive candidiasis in over 10 years.

Drug-resistant fungal infections are becoming more common, especially in patients with weakened immune systems. Serious fungal infections are often life-threatening with a mortality rate of up to 60%. Candida is part of the normal human microflora and invasive infections can occur if the organism is introduced into the bloodstream via catheter insertions, injections, endocarditis, or peritonitis. Candidemia and invasive candidiasis are often treated with antifungal agents such as fluconazole, caspofungin, and amphotericin B. However, the emergence of antimicrobial resistance in Candida species has complicated treatment strategies.

The introduction of Sulbactam-Durlobactam and Rezafungin expands the armamentarium of healthcare professionals. These new therapies provide hope for improved patient outcomes when drug-resistant microorganisms are encountered.

HardyDisk™ AST Sulbactam-durlobactam and HardyDisk™ AST Rezafungin will allow clinicians to make informed treatment decisions, ultimately improving patient care, and contributing to the global fight against antimicrobial resistance. Click here to see Hardy's complete selection of products for Antimicrobial Susceptibility Testing.

By Anna Klavins and Lauren Hamilton

Sulbactam-Durlobactam (Xanduro)

   Catalog# Z9461 - Single Pack

   Catalog# Z9465 - 5 Pack

Rezafungin (Rezzayo)

   Catalog# Z9471 - Single Pack

Gut bacteria found to produce anti-Staph molecules

Nearly a century ago, Alexander Fleming discovered penicillin (pictured at left), which was considered to be the first widely used antibiotic in modern medicine. Since then, a revolution in antibiotic therapy has generated several new compounds used to fight life-threatening infections.

Today, there are over one hundred antibiotics in common use and yet, this number is still not enough. Historically, scientists have discovered novel compounds found in environmentally sourced microbes. Recently, however, a newer approach to drug discovery was uncovered using the human microbiome. Scientists at the University of Tübingen, led by Dr. Bernhard Krismer, have discovered two molecules that play a key role in controlling bacterial infections. (1, 2, 3)

The first molecule discovered by the group is called lugdunin. Isolated from Staphylococcus lugdunensis, lugdunin has a unique thiazolidine-containing cyclic peptide structure shown to be effective against Staphylococcus aureus. (1) Researchers found that pretreatment with lugdunin on primary human keratinocytes, or mouse skin showed a significant reduction in S. aureus colonization. (1) Lugdunin increased immune factors in host cells, which in turn increased the activity of monocytes and neutrophils to fight off the invading pathogen. (1)

In addition to lugdunin, researchers also identified epifadin. This molecule is produced by Staphylococcus epidermidis in the nasal mucosa. (2,3) Epifadin shows promise as an antibiotic due to its novel structure, described as containing a non-ribosomally synthesized peptide, a polyketide, and a terminal modified acid moiety. (3) Studies found that administration of this compound to S. aureus cells caused cell lysis via cellular membrane disruption. (2)

Additional lab studies found that co-cultivation of S. aureus with epifadin producing S. epidermidis resulted in the elimination of S. aureus from the culture. (3) Discovery of this molecule was a challenge because, unlike many drugs, epifadin efficacy as an antimicrobial has a very short half-life of only a few hours. Although this is not ideal for drug discovery, scientists believe this molecule could still be a benefit to research by maintaining localized antimicrobial exposure in the body. (2) Consequently, the new structure and mechanism provided by epifadin may bring new drug models to the pharmaceutical industry. (2)

While studies show there is still much to learn about the human microbiome, this research demonstrates the rich complexity and potential that normal flora plays in the field of drug discovery. Lugdunin and epifadin are just two of the many natural compounds at our disposal as we continue to expand research into novel antibiotics.

References: 1, 2, 3

By Miles Amby, R&D Microbiologist, Hardy Diagnostics

Are you involved with a compounding pharmacy? If so, you will want to see our summary of the changes that are happening with USP <797>.

Click here to see the new revisions!