Short communication: Cold atmospheric plasma inactivation of Prototheca zopfii isolated from bovine milk

Genotypic and phenotypic diversity of Prototheca spp. recovered from bovine mastitis in terms of antimicrobial resistance and biofilm formation ability

BACKGROUND

The Prototheca algae have recently emerged as an important cause of bovine mastitis globally. Isolates from bovine mastitis in several countries were nearly all identified as P. bovis, suggesting that it was the main causative agent of bovine protothecal mastitis. The aim of the present study was to evaluate the presence and isolation of Prototheca spp. in dairy farms, detect the genetic diversity among strains, determine the capacity of producing biofilm and their resistance to antifungal and antimicrobial drugs.

RESULTS

A total of 48 Prototheca isolates from four different farms were randomly selected to be investigated. Multiplex PCR showed all isolated colonies were Prototheca bovis. Performing RAPD-PCR by using OPA-4 primer, it was revealed that there was a clear amplification pattern. Different levels of biofilm production were observed among strains. Among 48 isolates, only 4 of them (8.33%) showed strong biofilm production. By using E-test strips, amphotericin B was able to inhibit the growth of all the strains tested. Disc diffusion method used for antimicrobial sensitivity test showed that the highest activity was demonstrated by gentamicin and colistin with 95.83% (46/48) and 89.58% (43/48) of sensitive strains, respectively.

CONCLUSIONS

The present study showed that RAPD-PCR was a rapid tool for discriminating P. bovis strains. Also, gentamicin and colistin can be considered as potential antimicrobial drugs which can prevent the growth of the mentioned strains in vitro, although there is no effective clinical treatment yet. Further studies are needed in order to detect an effective clinical therapy considering biofilm production by Prototheca spp. and their probable role in Prototheca pathogenicity.

Recent trends and technological development in plasma as an emerging and promising technology for food biosystems

The rising need for wholesome, fresh, safe and “minimally-processed” foods has led to pioneering research activities in the emerging non-thermal technology of food processing. Cold plasma is such an innovative and promising technology that offers several potential applications in the food industry. It uses the highly reactive, energetic and charged gas molecules and species to decontaminate the food and package surfaces and preserve the foods without causing thermal damage to the nutritional and quality attributes of food. Cold plasma technology showed promising results about the inactivation of pathogens in the food industry without affecting the food quality. It is highly effective for surface decontamination of fruits and vegetables, but extensive research is required before its commercial utilization. Recent patents are focused on the applications of cold plasma in food processing and preservation. However, further studies are strongly needed to scale up this technology for future commercialization and understand plasma physics for getting better results and expand the applications and benefits. This review summarizes the emerging trends of cold plasma along with its recent applications in the food industry to extend shelf life and improve the quality of food. It also gives an overview of plasma generation and principles including mechanism of action. Further, the patents based on cold plasma technology have also been highlighted comprehensively for the first time.

Disinfection and Sterilization Using Plasma Technology: Fundamentals and Future Perspectives for Biological Applications

Recent studies have shown that plasma can efficiently inactivate microbial pathogens such as bacteria, fungi, and viruses in addition to degrading toxins. Moreover, this technology is effective at inactivating pathogens on the surface of medical and dental devices, as well as agricultural products. The current practical applications of plasma technology range from sterilizing therapeutic medical devices to improving crop yields, as well as the area of food preservation. This review introduces recent advances and future perspectives in plasma technology, especially in applications related to disinfection and sterilization. We also introduce the latest studies, mainly focusing on the potential applications of plasma technology for the inactivation of microorganisms and the degradation of toxins.