and #1057;haracterization of lytic activity of Phage SAvB14 on Staphylococcus aureus variant bovis

Abstract

Objective: The objective of this study was to investigate the intensity of phage infection caused by Phage SAvB14 , which was isolated from dairy farms, depending on the initial number of Staphylococcus aureus cells in the medium. Material and methods: To evaluate the impact of the viable bacteria S. aureus var. bovis on the intensity of phage infection caused by Phage SAvB14 , 1 mg of phagolysate (phage titer 10 5 CFU/ ml) was introduced in 9 ml of nutrient broth with an appropriate amount of daily culture of S. aureus var. bovis under study. The number of viable staphylococci was determined by total viable count/ml. Results: In this experiment, we found that the intensity of phages lytic activity was dependent on the number of sensitive bacterial cells in the volume of the culture medium. Effective phage therapy requires a high concentration of phages in the medium (inflammation foci) for rapid contact of the virus with bacteria. Conclusion: When developing a phage drug to treat subclinical mastitis, it is necessary to increase the phage titer in the drug or its dosage compared to the clinical form, as there is a lower probability of phage contact with a susceptible microbial cell. Besides, at a high concentration of bacteria, there is a gradual decrease in nutrients in the medium, resulting in phages going back to the condition of lysogeny.

Sensitivity of Staphylococcus aureus cultures of different biological origin to commercial bacteriophages and phages of Staphylococcus aureus var. bovis

“…Interest in lytic bacteriophages as antimicrobial agents is growing, due to their ability to self-replicate, their ubiquity in nature, and their high specificity to target bacteria. Phages which have high lytic activity and a wide range of hosts are therapeutically promising [ 6 , 12 , 19 ]. This study was performed to determine the lytic properties and to evaluate the range of hosts of bacteriophages of S. aureus var .…”

“…This study complements our earlier data on laboratory studies of phages of S. aureus var . bovis , including their morphology, lytic activity, and the effect of Phage SAvB14 on staphylococcal biofilms [ 3 , 6 , 26 ]. Prototypes of a drug based on Phage SAvB14 have been created, and clinical trials are underway.…”

“…The bacteriophages Phage SAvB07 , Phage SAvB08 , Phage SAvB12 , and Phage SAvB14 were previously isolated and described by us [ 6 ]. We also used drugs based on commercially available bacteriophages: Staphylococcal bacteriophage (Microgen, Russia) and Intestifag (Pharmex Group, Boryspil, Ukraine).…”

“…The genus Staphylococcus includes commensals and pathogens in both humans and animals [ 4 ]. Diseases caused by staphylococci, range from common food poisonings to serious nosocomial and livestock infections, including mastitis and endometritis [ 5 , 6 ]. As a result of the high frequency of carriers of staphylococci, the variety of pathologies caused by these bacteria, and the lack of an effective licensed vaccine, research into the development of new drugs against staphylococci is becoming increasingly important [ 7 , 8 ].…”

Toxicological evaluation of the drug "Fagomast" for the treatment of mastitis in cows

“…Однак, існуючі методи не завжди ефективні та потребують пошуку нових альтернатив (Yengkho, Gupta, Lokesha, Handique, & Singh, 2019). Одним із нових методів лікування є фаготерапія, тобто використання бактеріальних вірусів для знищення бактеріальних інфекцій (Gill et al, 2006;Horiuk, Horiuk, Kukhtyn, Tsvihun, & Kernychnyi, 2020).…”