Physical stability and biological and physicochemical properties of twelve Pseudomonas aeruginosa bacteriophages

Characterization studies were performed on two psychrophilic phages which were isolated from ground beef samples. Phage inactivation by exposure to heat, low pH, osmotic shock conditions, and freezing showed that these two isolates were different. One-step growth experiments indicated that one isolate had a burst size five times as large (500) and a latent period two times as long (4 hr) as the other when tested at 7 C. Nucleic acid type was 2-deoxyribonucleic acid for both. Electron micrographs showed one to belong to Bradley's phage group A and the other to phage group C.

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“…The effect of low pH was exerted at pH 5 and below for both phages (Table 2). These values agree well with those of other workers (11,13).…”

Section: Resultssupporting

confidence: 93%

Characterization of Two Psychrophilic Pseudomonas Bacteriophages Isolated from Ground Beef 1

Whitman

Marshall

1971

Applied Microbiology

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“…As shown in Table (1), lysed zones were formed by all five phage isolates at all pH levels (pH 3-12). Similarly, many previous studies refer to the stability of phages to different pH values, were reported by Roslycky et al (1962); Challaghan et al (1969); Hammad and Ali (1999); Fathy (2008). Whereas, bacteriophage isolates No.…”

Section: Characteristics Of the Isolated Phages The Optimum Ph For Ph...mentioning

confidence: 58%

Controlling foodborne pathogenic Citrobacter freundii via lytic bacteriophages

Mohamed,

Kelany,

Hammad

et al. 2023

SVU-International Journal of Agricultural Sciences

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Recently, foodborne diseases caused by pathogenic bacteria have been expanding. This requires searching for ways to control or get rid of these diseases. Using bacteriophages to control, prevent and treatment of foodborne diseases is one of the important actions due to their killer effect on bacteria. Many species of pathogenic bacteria can be transmitted through food, including Citrobacter freundii which can cause food poisoning, urethritis, abscess, and meningitis in infants. This study aimed to isolate and characterize bacteriophages specific to Citrobacter freundii to be used to control the contamination of food with Citrobacter freundii. C. freundii and its specific bacteriophages were isolated from sewage water. Isolated phages were found to be belonging to two phage species. These two phages had a head and tail and were designated Citro 1 and Citro 2. Phage Citro 1 has a long contractile tail and Citro 2 has a long non-contractile tail. Therefore, they were classified into Family Myoviridae and Family Siphoviridae, respectively. Application of bacteriophages to green salad artificially contaminated with C. freundii resulted in a high reduction in the density of C. freundii in green salad kept at both room temperature and at 4°C. Moreover, when the density of C. freundii decreased the number of phage particles increased. Such results may indicate that bacteriophages can be used to control the contamination of foodstuffs with pathogenic bacteria.

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