A New Phage Cocktail Against Multidrug, ESBL-Producer Isolates of Shigella sonnei and Shigella flexneri with Highly Efficient Bacteriolytic Activity

Abstract

The globally increasing incidence of antibiotic resistance in pathogenic microorganisms such as Shigella, a cause of human acute gastrointestinal infections, calls for developing effective alternatives. In this study, the antibiotic resistance pattern, extended-spectrum b-lactamase (ESBL)-production, and molecular characteristics of 70 multidrug-resistant isolates belong to the two most frequent species of Shigella genus, that is, Shigella sonnei (44 isolates) and Shigella flexneri (26 isolates) were investigated. These isolates were used to evaluate both specificity and activity of Shigella-specific bacteriophages, vB_SflS-ISF001, vB_SsoS-ISF002, and a cocktail of both. Twelve out of the 21 tested resistance genes were detected in the isolates. About 59% of S. sonnei and 46% of S. flexneri isolates were identified as ESBL producers. The bacteriophages showed a high efficiency of plating (EOP ‡0.5) in about 75% of the isolates. Moreover, the growth of >85% of the isolates was inhibited by the phage cocktail of vB_SflS-ISF001 and vB_SsoS-ISF002. The phage cocktail was effective against a wide range of ESBL-positive and -negative isolates of S. sonnei and S. flexneri. Therefore, this phage cocktail has the potential to inhibit or significantly decrease the spread of drug-resistant Shigella in humans, food chains, and water/wastewater sanitation systems.

An in‐vitro study on a novel six‐phage cocktail against multi‐drug resistant‐ESBL Shigella in aquatic environment

“…In other words, the anti-Shigella effect of the phages against the non-specific species could be considered as a complementary privilege guaranteeing a higher or even complete elimination of pathogens and preventing the formation of phage-resistant isolates through the synergistic effect of the specific phages. In our previous study, we reported the potential application of the bacteriolytic activity of a phage cocktail consists of vB_SflS-ISF001 and vB_SsoS-ISF002 against food and clinical Shigella isolates (Shahin et al 2019d(Shahin et al , 2020. Moreover, bacterial resistance against bacteriophages occurs through different mechanisms such as R/M, CRISPR-cas, defence genes encoded by plasmids or prophages.…”

Bacteriophage Cocktails Protect Dairy Cows Against Mastitis Caused By Drug Resistant Escherichia coli Infection

“…The infection and lysis capacity of phages were determined using the spot test method, as previously described (Shahin et al, 2020). Briefly, 100 µL of 20 exponential growth strains were mixed evenly with 10 mL semisolid LB medium and overlaid on the LB Agar (1.5% agar).…”

“…Understanding the genetic information of phage is essential for the safe and efficient clinical application (Shahin et al, 2020). All three isolated phages lacked harmful genes, such as lysogenic genes, antimicrobial resistance, and bacterial virulence, suggesting that they met the first criterion for phage therapy (Shahin et al, 2020).…”

“…Understanding the genetic information of phage is essential for the safe and efficient clinical application (Shahin et al, 2020). All three isolated phages lacked harmful genes, such as lysogenic genes, antimicrobial resistance, and bacterial virulence, suggesting that they met the first criterion for phage therapy (Shahin et al, 2020). Moreover, the genomes of all the three phages showed 90% similarities to the already existing phage genomes in the database indicating that there is abundance of these phages in the environment and is valuable to study the interaction of phages and their host for therapeutic purpose (Manohar et al, 2019).…”

Biodiversity of new lytic bacteriophages infecting Shigella spp. in fresh water environment

“…Ten microliters of the phage suspension (10 9 PFU mL − 1 ) was spotted onto double-layered BHI agar plates of each host strains (Additional le 1, Table S1). After an overnight incubation, the plates were checked for appearance of clear plaque (++), cloudy plaque (+) or no plaque (−).The e ciency of plating assay (EOP) was carried out against the Shigella isolates as described previously [27]. The EOP of the phage on their primary host strain (reference host) was considered as 1 and EOP of each strain were calculated as the ratio of phage titer on the tested bacterium to the phage titer on the reference host.…”