Antimicrobial activity of a novel Spanish propolis against planktonic and sessile oral Streptococcus spp

Abstract

Increased bacterial resistance to traditional antimicrobial agents has prompted the use of natural products with antimicrobial properties such as propolis, extensively employed since ancient times. However, the chemical composition of propolis extracts is extremely complex and has been shown to vary depending on the region and season of collection, due to variations in the flora from which the pharmacological substances are obtained, being therefore essential for their antimicrobial activity to be checked before use. For this purpose, we evaluate the in vitro antimicrobial and anti-biofilm activity of a new and promising Spanish ethanolic extract of propolis (SEEP) on Streptococcus mutans and Streptococcus sanguinis, responsible, as dominant ‘pioneer’ species, for dental plaque. Results reveal that S. sanguinis is more sensitive to SEEP, slowing and retarding its growth considerably with lower concentrations than those needed to produce the same effect in S. mutans. SEEP presents concentration- and time-dependent killing activity and, furthermore, some of the subinhibitory concentrations employed increased biofilm formation even when bacterial growth decreased. Mono and dual-species biofilms were also inhibited by SEEP. Findings obtained clearly show the relevance of using biofilm and subinhibitory concentration models to determine optimal treatment concentrations.

The Combination Effect of Ceftriaxone and Chloramphenicol on Staphylococcus aureus Isolate of Diabetic Gangrene

“…CTX has bactericidal effect whereas CML has bacteriostatic effect. When two antibiotics above are combined, the activity of bactericidal antibiotic will be inhibited by bacteriostatic antibiotic meaningful (Ocampo et al, 2014;Navarro-Pérez et al, 2021). CTX works through inhibiting the formation of cell wall, meanwhile CML blocking protein synthesis especially at ribosome sub unit 50S (Eyler and Shvets, 2019;Inayah et al, 2020).…”

“…CML cause slow growth of S. aureus furthermore it impairs bactericidal effect of CTX (Ocampo et al, 2014;Navarro-Pérez et al, 2021). The combination CTX and CML result antagonistic interaction based on AZDAST method.…”

“…Conditions at the site of infection that favor no growth or slow growth of bacteria will disrupt bactericidal action. Thus, whether a bactericidal or a bacteriostatic effect is achieved can vary depending on not only the antibiotic, however, the organisms and the growth conditions also (Eyler and Shvets, 2019;Navarro-Pérez et al, 2021). Antibiotic was classified as bacteriostatic and bactericidal sketchily, bacteriostatic inhibits replication and growth of bacteria.…”

“…The combination of antibiotics which include fixed combination has been proven and recognized as a fixed drug combination. Several combinations of antibiotics having bactericidal and bacteriostatic effect are not known exactly due to they are influenced by the dose (Navarro-Pérez et al, 2021). Theoretically, the combination of antibiotics is confirmed antagonist, however, it is still used because it is considered not clinically meaningful (Ocampo et al, 2014;Otoupal et al, 2021).…”

“…Treatment of diabetic foot infection using the combination of bactericidal antibiotic like Ceftriaxone (CTX) and bacteriostatic antibiotic like Chloramphenicol (CML) can produce antagonistic interactions based on theory (Navarro-Pérez et al, 2021;Złoch et al, 2021). Their interaction will reduce the efficacy of antibiotic.…”