Thymol Nanoemulsion: A New Therapeutic Option for Extensively Drug Resistant Foodborne Pathogens

Abstract

Foodborne pathogens have been associated with severe and complicated diseases. Therefore, these types of infections are a concern for public health officials and food and dairy industries. Regarding the wide-spread multidrug resistant (MDR) and extensively drug resistant (XDR) foodborne pathogens such as Salmonella Enteritidis (S. Enteritidis), new and alternative therapeutic approaches are urgently needed. Therefore, we investigated the antimicrobial, anti-virulence, and immunostimulant activities of a stable formulation of thymol as thymol nanoemulsion in an in vivo approach. Notably, treatment with 2.25% thymol nanoemulsion led to a pronounced improvement in the body weight gain and feed conversion ratio in addition to decreases in the severity of clinical findings and mortality percentages of challenged chickens with XDR S. Enteritidis confirming its pronounced antimicrobial activities. Moreover, thymol nanoemulsion, at this dose, had protective effects through up-regulation of the protective cytokines and down-regulation of XDR S. Enteritidis sopB virulence gene and interleukins (IL)-4 and IL-10 cytokines as those hinder the host defenses. Furthermore, it enhanced the growth of gut Bifidobacteria species, which increases the strength of the immune system. For that, we suggested the therapeutic use of thymol nanoemulsion against resistant foodborne pathogens. Finally, we recommended the use of 2.25% thymol nanoemulsion as a feed additive for immunocompromised individuals as well as in the veterinary fields.

Synthesis of Gold Nanoparticles by Using Green Machinery: Characterization and In Vitro Toxicity

“…To determine the ability of synthesized GNPs to inhibit bacterial growth, the agar diffusion method was used according to the Clinical Laboratory and Standards Institute Guidelines (CLSI 2015) [38]. Standardized suspensions of the tested strains (equivalent to the 0.5 McFarland) were prepared from overnight cultures in TSB and swabbed over the surface of Müeller-Hinton agar plates.…”

“…The MICs were the lowest concentrations of synthesized GNPs that completely inhibited the bacterial growth after incubation at 37 • C for 20 h and the bacterial cells were viably counted from each well. Meanwhile, the lowest concentrations of GNPs that showed no visible growth upon subculturing onto fresh medium were considered minimum bactericidal concentrations (MBCs) [38]. Colistin sulfate was used as a positive control, sterile PBS was involved as a negative control, and the experiment was repeated in triplicate.…”

“…Many reports tackle the problem of bacterial resistance by renewal of the therapeutic applications of the medicinal plants or drug repurposing [4,46,47]. Moreover, new approaches were developed to improve the distribution, penetration, targeting, and pharmacokinetics of antimicrobial drugs; one of these is drug nanoparticle formulations [36,38]. Metallic nanoparticles were employed for delivering antimicrobials efficiently, showing a magnificent enhancement in targeting and improvement of pharmacokinetics [5,6,8,9,28,49].…”

Not Only Antimicrobial: Metronidazole Mitigates the Virulence of Proteus mirabilis Isolated from Macerated Diabetic Foot Ulcer

“…Without affecting the bacterial growth, this strategy decreases the possibility of the bacterial resistance development [19][20][21]. In this direction, several groups investigated the anti-virulence and anti-QS activities of safe naturally products or FDA approved drugs [16,17,[21][22][23][24][25][26][27]. Metronidazole is very widely used antimicrobial mainly against most anaerobic Gram-negative and -positive bacteria and protozoans [28].…”

Xylitol Inhibits Growth and Blocks Virulence in Serratia marcescens

“…The cDNA amplification was performed with the SYBR Green Quantitative RT-qPCR Kit (Thermo Fisher Scientific, Waltham, MA, USA). The expression levels of virulence genes fimA , fimC , rssB , bsmB , rsmA , shlA , pigB , flhC and flhD were standardized in relation to the critical threshold (CT) mean values of rplU as a housekeeping gene by the 2 −∆∆Ct method [ 32 , 33 , 34 ]. The designed genes’ primers and PCR cycles used in this study have been designated formerly [ 7 , 25 ].…”