Bakteriye saldıran bakteriyofaj virüslerinin çizimi.
Bilim adamları, kontaminasyona ve enfeksiyona karşı güçlü ve yeni bir silah yaratmak için bakteri yiyen virüslerden yararlanıyor.
Araştırmacılar, bakteriyofajları (bakterileri yiyen zararsız virüsler) birbirine bağlayıp mikroskobik boncuklar oluşturmaya ikna etmenin bir yolunu geliştirdiler. Bu boncuklar, zararlı patojenlerden kurtulmak için gıda ve diğer malzemelere güvenle uygulanabilir. E. coli O157. Her boncuk yaklaşık 20 mikron (milimetrenin 50’de biri) çapındadır ve milyonlarca fajla yüklüdür.
E. coli O157, bakterinin yüzlerce suşundan biridir Escherichia coli. Çoğu suş E. coli Zararsızdırlar ve sağlıklı insan ve hayvanların bağırsaklarında yaşarlar. Bununla birlikte, O157 suşu, ciddi hastalığa neden olabilecek güçlü bir toksin üretir. Enfeksiyon belirtileri şiddetli ishal (genellikle kanlı) ve karın kramplarını içerir.
Buluşun arkasındaki McMaster mühendislik ekibi, mikro boncuklardan başka bir şey kullanmadan bir sprey yarattı. Ekip, Bakteriyofaj Biyomühendisliğinde Kanada Araştırma Kürsüsü’nü elinde bulunduran profesörler Zeinab Hosseinidoust ve Nano-Biyomateryaller’de Kanada Araştırma Kürsüsü’nü elinde bulunduran Tohid Didar ve yüksek lisans öğrencisi Lei Tian tarafından yönetiliyor.
Etkili dergide bugün (5 Aralık) yayınlanan bir makalede açıkladıkları gibi, püskürtülebilir yeni süper dezenfektanları gıda için güvenli ve oldukça etkilidir. 
Researchers tested their food-safe antibacterial spray on foods including beef and romaine lettuce. Credit: McMaster University
Graduate student and Vanier scholar Shadman Khan worked with Tian to test the antibacterial spray on food products.
“When we spray it on food, we basically gather billions of mini-soldiers to protect our food from bacterial contamination,” says Tian, who led the study as part of his PhD research.
The research builds on the same chemistry work that Hosseinidoust’s lab had previously used to trigger phages to connect to one another in quantities sufficient to form a gel.
“They link together like microscopic LEGO pieces,” she says. “This organized natural structure makes them much more durable and easier to package, store and use.”
McMaster University researcher Lei Tian. Credit: McMaster University
Before the introduction of penicillin in the 1940s, research into phage disinfectants and therapies had been very promising, but interest in developing their potential dimmed once antibiotics made from penicillin came onto the market. With antimicrobial resistance now sapping the power of existing antibiotics, there is intense new interest in phage research.
When phages – which occur naturally in the body and in the environment – contact target bacteria, they multiply, explosively increasing their antimicrobial power as they work.
“It’s a chain reaction, creating a dynamic and ongoing response that is even more overpowering than antibiotics,” Didar says. “No other antibacterial product – not even bleach – has the special properties that phages do.”
McMaster University researcher Zeinab Hosseinidoust. Credit: McMaster University
Another major advantage of using phages in agriculture and food production is that they can be directed very specifically to take out harmful strains of bacteria without killing beneficial bacteria that enhance foods’ taste, smell, and texture.
The new phage spray has promising potential for commercial application, the researchers say, especially since phages have already earned approval from the US Food and Drug Administration for use in food.
The research paper shows the sprayable material can eliminate E. coli O157 in lettuce and meat, which are often the sources of disease outbreaks.
McMaster University researcher Tohid Didar. Credit: McMaster University
The researchers say the same approach can readily be used against other bacteria which cause food poisoning, such as Salmonella and Listeria – individually or in combination.
Phage sprays could be used in food processing, packaging, and cleaning, and even as a treatment for irrigation water and equipment, stopping contamination at the source, the researchers say.
The research, completed under the umbrella of McMaster’s Global Nexus for Pandemics and Biological Threats, combines and extends the previous work of Hosseinidoust’s lab with work that Didar and other McMaster colleagues had done to create microscopic sensors and surfaces to detect and repel food pathogens.
Reference: “Self-assembling nano!brous bacteriophage microgels as sprayable antimicrobials targeting multidrug-resistant bacteria” 5 December 2022, Nature Communications.
DOI: 10.1038/s41467-022-34803-7
Co-authors on the paper also include Leon He, Kyle Jackson, Ahmed Saif, and Zeqi Wan.
The group next plans to test the new material’s promising applications in medicine, where it might be used in disinfecting wounds, for example. Medical applications will take more time to be proven safe and effective, but a product made for disinfection in food processing could make it to market much more quickly.