Wednesday 28 June 2023

New class of antibiotics to fight resistant bacteria


Researchers have modified the chemical structure of naturally occurring peptides to develop antimicrobial molecules that bind to novel targets in the bacteria's metabolism.


The University of Zurich and the company Spexis have modified the chemical structure of naturally occurring peptides to develop antimicrobial molecules that bind to novel targets in the bacteria's metabolism. This has led to a new class of antibiotics that fight Gram-negative bacteria in a novel way. This includes carbapenem-resistant enterobacteria.


The starting point for the researchers' study was a naturally occurring peptide called thanatin, which insects use to fend off infections. Thanatin disrupts an important lipopolysaccharide transport bridge between the outer and inner membrane of Gram-negative bacteria. As a result, these metabolites build up inside the cells, and the bacteria perish. 


Antimicrobial peptides (AMPs) possess great potential for combating drug-resistant bacteria. Thanatin is a pathogen-inducible single-disulfide-bond.


However, thanatin is not suitable for use as an antibiotic drug, among other things due to its low effectiveness and because bacteria quickly become resistant to it.


The researchers therefore modified the chemical structure of thanatin to enhance the peptide's characteristics. Here, the scientists synthetically assembled the various components of the bacterial transport bridge and then used nuclear magnetic resonance (NMR) to visualize where and how thanatin binds to and disrupts the transport bridge.


Using this information, researchers from Spexis AG planned the chemical modifications that were necessary to boost the peptide's antibacterial effects. Further mutations were made to increase the molecule's stability, among other things.


The synthetic peptides were then tested in mice with bacterial infections -- and yielded good results, being effective against carbapenem-resistant enterobacteria.


Journal Reference:


Matthias Schuster, Emile Brabet, Kathryn K. Oi, et al. Peptidomimetic antibiotics disrupt the lipopolysaccharide transport bridge of drug-resistant Enterobacteriaceae. Science Advances, 2023; 9 (21) DOI: 10.1126/sciadv.adg3683


Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

Tuesday 27 June 2023

5 Pieces of Safety Equipment to Have on Hand in the Lab

 Image: By Jogi don - Own work, CC BY-SA 4.0

Safety should always be the top priority in any science lab. A safe working environment is crucial to protecting researchers, preventing accidents, and maintaining the integrity of experiments. One of the fundamental aspects of lab safety is having the appropriate safety equipment readily available.


The Importance of Safety Equipment in a Science Lab


Safety equipment plays a vital role in safeguarding laboratory personnel from potential hazards. It serves as a protective shield against accidents, chemical spills, and exposure to harmful substances. Using appropriate safety equipment, researchers can promote a safety culture within the lab.


Five Pieces of Safety Equipment to Have On Hand in the Lab


Here are five essential safety equipment items for a well-prepared lab environment.


1. Hood Vent


A hood vent, also known as a fume hood, is a critical safety gadget that effectively removes hazardous fumes, vapors, and gases from the lab environment. It ensures proper ventilation, protecting researchers from inhaling potentially harmful substances.


2. Lab Coats


Lab coats are designed to shield the body and clothing from chemical spills and splashes. They act as a barrier between researchers and hazardous substances, reducing the risk of skin contact and contamination. Lab coats should be made of suitable materials and properly fastened to ensure full coverage.


3. Protective Gloves


Protective gloves are essential for hand protection in the lab. They create a barrier between the skin and chemicals, preventing direct contact and potential harm. Choosing gloves made from compatible materials is crucial based on the nature of the substances being handled.


4. Safety Goggles


Safety goggles are indispensable for eye protection in the lab. They shield the eyes from chemical splashes, flying debris, and potential exposure to harmful radiation. It is essential to wear goggles that meet the appropriate safety standards and fit properly for eye protection.


5. Fire Extinguishers


Fire extinguishers are a crucial safety feature in any lab setting. They enable rapid response to fire emergencies, helping to suppress flames and prevent the spread of fires. Fire extinguishers should be strategically located and regularly inspected to ensure they are fully functional and easily accessible.


What to Avoid in a Scientific Lab for Safety Reasons


The following practices should be avoided to maintain a safe lab environment.


1.Inappropriate Labeling of Samples


Proper labeling of samples and materials is crucial for accurate identification and preventing mix-ups. Failing to label containers can lead to confusion, compromised experiments, and potential safety hazards.


2. Wearing Open-Toed Shoes


Open-toed shoes leave the feet vulnerable to chemical spills, falling objects, and potential injuries. Closed-toe shoes provide necessary protection and should always be worn in the lab.


3. Eating or Drinking


Consuming food or beverages in the lab is strictly prohibited. Accidental ingestion of hazardous substances or contamination of consumables can have severe health consequences.


Safety equipment is an indispensable aspect of any science lab. Researchers can ensure a safer working environment by having essential pieces of equipment readily available, such as hood vents, safety goggles, lab coats, protective gloves, and fire extinguishers. Additionally, avoiding risky practices like wearing open-toed shoes, eating or drinking, wearing shorts, and inappropriate labeling of samples is essential to maintaining a safe laboratory. Prioritizing safety not only protects researchers but also enhances the reliability and integrity of scientific experiments.


Written by Taylor McKnight, Author for LOC Scientific

Pharmaceutical Microbiology Resources (

Aspergillus fumigatus - new insight into pathogenicity


Image: By CDC/Dr. Libero Ajello (PHIL #4297)


An interesting article from The Scientist looks at the pathogenicity of Aspergillus fumigatus, a common filamentous fungus that can cause pulmonary infections in people and which is especially problematic to those with weakened immune systems.


The organism is a saprotrophic fungus with a cosmopolitan distribution and is typically found in soil and decomposing organic material, such as compost heaps. It plays an essential role in carbon and nitrogen recycling. It is one of the most common ubiquitous airborne saprophytic fungi and is predominantly found in the air, hence it is constantly inhaled in the form of conidia by humans and animals.



Aspergillus fumigatus is the most frequent cause of invasive fungal infection in immunosuppressed individuals. In immunocompromised individuals, such as organ transplant recipients and people with AIDS or leukaemia, the fungus is more likely to become pathogenic, over-running the host's weakened defences and causing a range of diseases generally termed aspergillosis.


The article describes how A. fumigatus avoids the host immune system by entering into mammalian cells by using membrane-enclosed vesicles known as phagosomes. The pathogen-containing vesicles are adept at avoiding intracellular elimination.


For details see:

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (

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