Antibacterial Activity of Propolis Extracts from the Central Region of Romania against Neisseria gonorrhoeae

(1) Background: Sexually transmitted infections (STIs) are among the most common infections worldwide, many of these being caused by Neisseria gonorrhoeae (NG). Increased antimicrobial NG resistance has been reported in recent decades, highlighting the need for new sources of natural compounds with valuable antimicrobial activity. This study aims to determine the effect of propolis extracts on NG strains, including antibiotic-resistant strains. (2) Methods: First void urine samples from presumed positive STI subjects were harvested. DNA was extracted, purified, and amplified via PCR for the simultaneous detection of 6 STIs. The presence of the dcmH, gyrA, and parC genes was checked in the DNA samples from NG-positive patients. The antimicrobial activity of 5 aqueous propolis extracts from central Romania was investigated in vitro against some isolated NG strains. ANOVA tests were employed to assess differences and interactions between the inhibition zone for NG strains and propolis extracts. (3) Results: 7.07% of the patients presented NG infections, some strains being resistant or intermediate-resistant to ciprofloxacin. All propolis samples exhibited an antibacterial effect, including on resistant strains. (4) Conclusions: Statistical analysis demonstrated that the diameter of the inhibition zone was influenced both by the NG strain type and the source of the propolis extracts.