Assessment of synergistic combination potential of probiotic and bacteriophage against antibiotic-resistant Staphylococcus aureus exposed to simulated intestinal conditions

Abstract

This study was designed to evaluate the combined effect of probiotic Lactobacillus rhamnosus and bacteriophage SA11 on the control of antibiotic-sensitive Staphylococcus aureus (ASSA) and antibiotic-resistant S. aureus (ARSA) under the simulated intestinal conditions. The survivability of ASSA and ARSA were determined in the simulated phosphate-buffered saline (PBS)-, trypticase soy broth (TSB)-, and milk-based gastric juices adjusted to pH 2.0, 3.0, and 5.0 at 37 °C for 30 min. The inhibitory effect of bacteriophage SA11 and probiotic on the growth of ASSA and ARSA was evaluated in the simulated intestinal juices at 37 °C for 20 h. The least reductions in the numbers of ASSA and ARSA were observed in the milk-based gastric juices at pH 2.0 (<1 log). No significant changes in the teichoic acid-mediated sliding motility were observed for ASSA and ARSA after 30-min exposure to the simulated gastric juices (pH 2.0, 3.0, and 5.0), responsible for the enhanced bacterial attachment to the epithelial cells. The bacteriophage SA11 was stable down to pH 5.0 and up to 0.06 % bile salts. The bacteriophage SA11 combined with probiotic effectively inhibited the growth of ASSA and ARSA in the simulated intestinal conditions, showing more than 4 log reduction. The relative expression levels of adhesion-related genes (clfA, eno, and fnbA) and efflux-related genes (mdeA, norB, and norC) were less decreased in ARSA than in ASSA after exposure to the simulated gastrointestinal conditions. These results might shed light on the application of bacteriophage to control the ingested antibiotic-resistant foodborne pathogens in the intestinal tract.

Evaluation of lytic bacteriophages for control of multidrug-resistant Salmonella Typhimurium

“…2 b). This is in good agreement with previous study showing most bacteriophages are highly stable at pHs between 4 and 9 [ 17 , 18 ]. The observations suggest that the adsorption rates of Salmonella bacteriophages tested in this study may not be changed at the broad ranges of temperature and pH, which are the important environmental factors for the lytic activity of bacteriophages [ 19 ].…”

Application of chitosan–alginate microspheres for the sustained release of bacteriophage in simulated gastrointestinal conditions

“…coli O157:H7 was reduced by 3.8 and 0.3 log units, respectively, after 5 and 10 h of incubation in the simulated intestinal conditions treated with free bacteriophages. This observation suggests that the susceptibility of free bacteriophages to intestinal condition decreased with increasing the incubation time, resulting in the loss of lytic activity (Woo & Ahn, ). The encapsulated bacteriophages effectively inactivated the growth of E .…”

Antimicrobial Activity of a Phage Mixture and a Lactic Acid Bacterium against Staphylococcus aureus from Bovine Mastitis

“…The results of the present investigations are partly comparable to the results of Woo and Ahn (2014) for their examination of a combined use of phage SA11 and a Lactobacillus (Lb.) rhamnosus strain against Staphylococcus aureus for modeled intestinal conditions in vitro at different pH values [61]. Phage SA11 inhibited the growth of antibiotic-sensitive and -resistant S. aureus strains if compared to the control cultures after 10 h, whereas the single use of Lb.…”

“…rhamnosus led to an inhibition of the germ density first after 20 h in comparison to the corresponding values of the control culture without phages. Thus, the authors suggested that phage lytic activity was predominant after 10 h of incubation and the antimicrobial activity of LAB after 20 h. The authors described the highest reduction ability for a combined application of phage and LAB after 10 h and 20 h [61].…”

“…These include, among others, the protection of the apathogenic flora when using phages [21], the modulation of the immune system by LAB as a probiotic property [34] as well as a self-limitation of phages at low S. aureus concentrations [17] and, in contrast, a possible long-term effect of LAB by establishing themselves in the udder. There are already investigations on a combined use of phages and probiotics against different pathogens [61,64,65]. Dini et al (2016) demonstrated pathogen reduction in the treatment of in vitro EHEC infection using the phage CA933P and a probiotic mixture, with a diminishing cytotoxic effect.…”