Bacterial Aetiology and Susceptibility of Pathogens Associated with Acne Vulgaris

Abstract

Introduction: Acne vulgaris is a pilosebaceous disorder among youth during puberty and also in young adults. Hormonal imbalance, bacterial activity and inflammation can cause acne formation. Due to some anti-inflammatory effects and temporary self treatment of acne using some antibiotics, there is overuse/ improper use of antimicrobial agents which leads to resistance in bacterial strains. Aim: To provide an overview of bacteria that may cause acne and determine their susceptibility to antibiotics and reduce the overuse of antibiotics which leads to antibiotic resistance. Materials and Methods: This was a cross-sectional study done on samples from from 100 patients with chief complaints of acne, attending Dermatology Department at Konaseema Institute of Medical Sciences and Research Foundation (KIMS RF). This study was done between November 2019 to February 2021. Acne pustules were cultured on all the basic media like blood agar and Mac Conkey agar, under aerobic and anaerobic conditions. Bacterial identification was performed by gram staining and relevant biochemical tests. Antibiotic susceptibility was done based on the Clinical and Laboratory Standards Institute (CLSI) 2019. Data was calculated and analysed statistically by Statistical Package for Social Science (SPSS) version 21.0. Results: Total 100 participants were taken for the study. Females (63%) were more commonly affected as compared to males (37%) and the most commonly affected age group was teenage i.e., 10 to 20 years in both male and females. Among 100 subjects, 77 cases showed bacterial growth by aerobic and anaerobic culture and 23 cases showed negative for bacterial culture. All isolates were susceptible to rifampin (100%) (p<0.001). Propionibacterium acnes (P. acnes) was susceptible to doxycycline (88.8%) and minocycline (88.8%), while 22.3% was resistant to erythromycin, clindamycin, and tetracycline while 33.3% showed resistance to ofloxacin. Gram positive cocci like Staphylococcus epidermidis (S.epidermidis) was susceptible to the antibiotic minocycline and rifampin (100%); but resistant to quinolines like ofloxacin (52.5%) macrolides like erythromycin (62.5%), clindamycin (47.5%) and tetracycline (17.5%). The susceptibility of gram positive cocci like S. epidermidis to doxycycline was (87.5%), which was lower than that of P. acnes (88.8%). Staphylococcus aureus (S. aureus) was found to be sensitive to minocycline (90.9%), doxycycline (72.7%), clindamycin (63.6%), and tetracycline (63.6%); but it was resistant to macrolide like erythromycin (45.5%) and quinolines like ofloxacin (36.5%). Conclusion: This study suggested that bacterial culture and antibiotic sensitivity can be better suggested if the culture and sensitivity is available so that, sensitivity and resistant pattern is known. The use of clindamycin and macrolide (erythromycin) needs to be reduced as most gram positive cocci like S. epidermidis were resistant to both.