Antimicrobial Activity of Aqueous Citrus limon Extract against Streptococcus pyogenes (Group A) Isolated from Sore Throat Patients in Jeddah City, Saudi Arabia

Abstract

Plant-based therapeutics known to be easily biodegradable, natural and available, with minimal adverse side effects and is easily accessible at low prices. This study was aimed to determine the antimicrobial activity of aqueous Citrus limon on clinically isolated Streptococcus pyogenes from sore throat patients in Jeddah, Saudi Arabia, during the period from October 2018 to December 2019. A total of 135 throat swab samples were collected from patients suffering from sore throat patients, Streptococcus pyogenes were isolated by rapid strep test and standerd cultural techniques and identification by using Gram’s stain and biochemical tests. Also, the antimicrobial activity of aqueous Citrus limon extract was done using a cup plate method. A total of 135 infected patients with sore throat were enrolled in this study, their age ranged from 3-54 years, with a mean age of 8.84 ± in and 7.54 SD. Patients age were classified into four groups as follow: age ranged (<15) years was 123(91.1%) patients, (15-30) years was 7(5.2%)patients, (31-45) years was 4(3%) patients and (>45) years was 1(0.7%) patient. Females were 74 (54.8%), while males were 61(45.2%). Out of 135, 72(53.3%) were showed positive growth of S. pyogenes by rapid strep test showing (100%) specificity and sensitivity. All 72/135 (53.3%) were showed fever and difficult to swallow, while 64/72 (88.9%) were showed exudate production, only 1/72 (0.7%) patient was on antibiotic treatment and history of recurrent infection. Regarding age group 68/72 (88.6%) of patients were showed positive growth of S. pyogenes in age group (1-15) years, 2/72(2.8%) in (16-30) years, and 2/72 (2.8%) in (31-45) years which showed statistically insignificant difference between S. pyogenes growth and age (P. value = 0.67). S. pyogenes were 40/72 (55.6%) isolated from females, and 32/72 (44.4%) from males, there was an insignificant association between the S. pyogenes and the gender (P. value =0.85). Regarding exudate, S. pyogenes were isolated from 64/72(88.9%) patients with exudate production which showed a highly statistically significant difference between S. pyogenes throat infection and exudate production (P. value = 0.00). Considering penicillin treatment and history of recurrent infection, only 1/72 (1.4%) were re-infected with Streptococcus pyogenes and was under treatment which showed the statistically insignificant difference between S. pyogenes growth, treatment, and history of recurrent infection (P. value = 0.34) The different concentration (12.5%, 25% 50%, and 100%) (v/v) of Citrus limon juice extract was evaluated, Citrus limon aqueous extract was showed antimicrobial activity against tested bacteria; the highest mean of zone of inhibition observed in concentration 100% with mean of 21.5± 1.35 STD, 50% the mean was of 17.8 ± 1.59 STD, 25% was 14.2 ± 2.86 STD, while 12.5% was showed no zone of inhibition. In conclusion Streptococcus pyogenes was the most frequent bacterial causes sore throat with no association of Streptococcus pyogenes pharyngitis with age and sex as a risk factors, treatment, and history of recurrent infection. Highly associations were found between Streptococcus pyogenes and exudate production. Citrus limon juice extract was found to be effective against Streptococcus pyogenes the effect was found to be increased when increasing the extract concentration.