The antibacterial spectrum expansion of Nisin

Nisin, also known as nisin streptococcus lactis, is a natural preservative initially widely used for its outstanding performance in food preservation. In recent years, its antibacterial spectrum has continuously expanded, demonstrating great potential in the medical field. The following is a detailed introduction:

I. Traditional Applications in the Food Industry and Basis of Antibacterial Spectrum

1. Traditional Antibacterial Spectrum

Nisin primarily exhibits potent inhibitory and bactericidal effects against Gram-positive bacteria, particularly common foodborne pathogens such as Bacillus and Listeria. For example, it effectively suppresses the growth and reproduction of Staphylococcus aureus and Bacillus subtilis, preventing food spoilage and extending shelf life.

2. Applications in the Food Industry

Due to its excellent antibacterial properties and safety, Nisin is widely used in various foods, including fruit juices, dairy products, meat products, and canned foods.

In dairy products, it inhibits excessive fermentation of lactic acid bacteria, maintaining product stability and taste.

In meat products, it effectively suppresses harmful microorganisms like Clostridium botulinum, ensuring food safety.

II. Potential for Expanding the Antibacterial Spectrum in the Medical Field

1. Action Against Drug-Resistant Bacteria

Addressing Gram-Positive Drug-Resistant Bacteria

With the widespread use of antibiotics, drug resistance in Gram-positive bacteria has become increasingly severe, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Nisin exhibits certain antibacterial activity against these drug-resistant bacteria, offering new treatment options for related infections. Studies show that Nisin disrupts bacterial cell membrane structures and interferes with normal physiological functions to inhibit or kill drug-resistant bacteria.

Potential Action Against Gram-Negative Bacteria

Although Nisin traditionally targets Gram-positive bacteria, recent research has found that chemical modification or combination with other substances can enhance its effect on Gram-negative bacteria. The complex outer membrane structure of Gram-negative bacteria acts as a natural barrier to many antibacterial agents, but Nisin may exert effects by altering outer membrane permeability and entering bacterial interiors.

2. Anti-Biofilm Formation

Harm of Biofilms

Biofilms are complex aggregates of bacteria formed on surfaces, protecting bacteria from external environments, including antibiotics and host immune attacks. Biofilm formation is closely linked to many chronic infections and medical device-related infections, such as catheter-related bloodstream infections and prosthetic joint infections.

Mechanism of Nisin's Action

Nisin interferes with biofilm formation, inhibits bacterial adhesion and aggregation, and disrupts established biofilm structures. It interacts with components such as polysaccharides and proteins in biofilms to prevent bacterial colonization and growth on surfaces, reducing the risk of infection.

3. Expanded Application Scenarios in Medicine

Wound Care

Infection is a common issue during wound healing. Nisin can be added to wound dressings as an antibacterial agent to prevent and treat wound infections. Its natural and safe properties make it suitable for various wound types, including burns, trauma, and surgical incisions.

Oral Hygiene

The oral cavity harbors numerous bacteria, some of which are closely linked to dental caries, periodontitis, and other diseases. Nisin can be added to oral care products such as toothpaste and mouthwash to inhibit harmful oral bacteria and prevent oral diseases.

Treatment of Ocular Infections

Ocular infections (e.g., conjunctivitis, keratitis) are common ophthalmological diseases. Nisin’s antibacterial properties make it a potential candidate for ophthalmic medications to treat bacterial ocular infections. Its relatively mild nature also minimizes irritation to ocular tissues.

III. Challenges and Future Prospects

1. Challenges

Despite its great potential in expanding the antibacterial spectrum, widespread medical application of Nisin faces challenges:

Its stability needs further improvement to maintain effective antibacterial activity in different medical environments and scenarios.

In-depth research on its safety and pharmacokinetic characteristics in humans is required to provide a more solid basis for clinical use.

2. Prospects

With ongoing research and technological advancements, Nisin’s antibacterial spectrum in the medical field is expected to further expand. It may become a novel antibacterial drug or material, offering new ideas and methods for addressing bacterial drug resistance and treating infectious diseases.