Objective: This study aimed to determine the antimicrobial property of oregano (Plectranthus amboinicus) crude leaf extract against pathogens that infect the throat, specifically Streptococcus pyogenes and Candida albicans using the broth and checkerboard dilution methods.

Methods: This study employed an experimental study design using broth dilution method for the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) against Streptococcus pyogenes ATCC 19615, and minimum fungicidal concentration (MFC) against Candida albicans ATCC 14053 of P. amboinicus crude extract (PA extract). Checkerboard dilution method was then used for determination of the synergy between PA extract and the standard antimicrobials.

Results: In vitro growth inhibition of S. pyogenes (MIC 0.13 g/mL) and C. albicans (MIC 0.03 g/mL) was exhibited by the PA extract. The highest concentration of PA extract used in this study was not sufficient to demonstrate bactericidal and fungicidal activity (MBC >0.25 g/mL, MFC >0.25 g/mL). Results of checkerboard dilution method revealed that PA extract when combined with either penicillin (for S. pyogenes) or nystatin (for C. albicans) demonstrated indifference.

Conclusion: The crude extract of Plectranthus amboinicus has the capability to inhibit the growth of both S. pyogenes and C. albicans. This demonstrates its potential use in the treatment of throat infections caused by these organisms.

Key Words: Plectranthus amboinicus, oregano, antimicrobial, throat infections, herbal medicine

Origanum ; Herbal Medicine

Objective: We examined sociobehavioural factors associated with SARS-CoV-2 infection and estimated COVID-19 vaccine effectiveness against symptomatic SARS-CoV-2 infection in the Philippines. Such studies are limited in low- and middle-income countries, especially in Asia and the Pacific. Methods: A case-control study was conducted in two hospitals in Manila, Philippines, from March 2022 to June 2023. Sociobehavioural factors and vaccination history were collected. PCR-positive individuals were cases, while PCR-negative individuals were controls. Adjusted odds ratios (aORs) were calculated to examine associations between sociobehavioural factors/vaccination and medically attended SARS-CoV-2 infection. Results: The analysis included 2489 individuals (574 positive cases, 23.1%; 1915 controls, 76.9%; median age [interquartile range]: 35 [27–51] years). Although education and household income were not associated with infection, being a health-care worker was (aOR: 1.45; 95% confidence interval [CI]: 1.03–2.06). The odds of infection were higher among individuals who attended gatherings of five or more people compared to those who attended smaller gatherings (aOR: 2.58; 95% CI: 1.14–5.83). Absolute vaccine effectiveness for vaccination status was not estimated due to a high risk of bias, for example, unascertained prior infection. Moderate relative vaccine effectiveness for the first booster (32%; 95% CI: -120–79) and the second booster (48%; 95% CI: -23–78) were observed (both with wide CI), albeit with a waning trend after half a year. Discussion: The higher odds of infection among health-care workers emphasize the importance of infection prevention and control measures. Moderate relative vaccine effectiveness with a waning trend reiterates the need for more efficacious vaccines against symptomatic infection caused by circulating variants and with longer duration of protection.