title: Cross-sectional Pilot Study of Antibiotic Resistance in Propionibacterium Acnes Strains in Indian Acne Patients Using 16S-RNA Polymerase Chain Reaction: A Comparison Among Treatment Modalities Including Antibiotics, Benzoyl Peroxide, and Isotretinoin.
abstract: BACKGROUND
  Antibiotic resistance is a worldwide problem in acne patients due to regional prescription practices, patient compliance, and genomic variability in Propionibacterium acnes, though the effect of treatment on the resistance has not been comprehensively analyzed.
  
  
  OBJECTIVE
  Our primary objective was to assess the level of antibiotic resistance in the Indian patients and to assess whether there was a difference in the resistance across common treatment groups.
  
  
  METHODS
  A cross-sectional, institutional based study was undertaken and three groups of patients were analyzed, treatment naïve, those on antibiotics and patients on benzoyl peroxide (BPO) and/isotretinoin. The follicular content was sampled and the culture was verified with 16S rRNA polymerase chain reaction, genomic sequencing, and pulsed-field gel electrophoresis. Minimum inhibitory concentration (MIC) assessment was done for erythromycin (ERY), azithromycin (AZI), clindamycin (CL), tetracycline (TET), doxycycline (DOX), minocycline (MINO), and levofloxacin (LEVO). The four groups of patients were compared for any difference in the resistant strains.
  
  
  RESULTS
  Of the 52 P. acnes strains isolated (80 patients), high resistance was observed to AZI (100%), ERY (98%), CL (90.4%), DOX (44.2%), and TETs (30.8%). Low resistance was observed to MINO (1.9%) and LEVO (9.6%). Statistical difference was seen in the resistance between CL and TETs; DOX/LEVO and DOX/MINO (P < 0.001). High MIC90 (≥256 μg/ml) was seen with CL, macrolides, and TETs; moreover, low MIC90 was observed to DOX (16 μg/ml), MINO (8 μg/ml), and LEVO (4 μg/ml). Though the treatment group with isotretinoin/BPO had the least number of resistant strains there was no statistical difference in the antibiotic resistance among the various groups of patients.
  
  
  CONCLUSIONS
  High resistance was seen among the P. acnes strains to macrolides-lincosamides (AZI and CL) while MINO and LEVO resistance was low.
authors.affiliation: Department of Dermatology, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi - 110 025, India.
authors.forename: Kabir
authors.initials: K
authors.lastname: Sardana
authors.affiliation: Department of Dermatology, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi - 110 025, India.
authors.forename: Tanvi
authors.initials: T
authors.lastname: Gupta
authors.affiliation: CSIR-Institute of Genomics and Integrative Biology, Department of Microbial Biotechnology, Sukhdev Vihar, Mathura Road, New Delhi - 110 025, India.
authors.forename: Bipul
authors.initials: B
authors.lastname: Kumar
authors.affiliation: CSIR-Institute of Genomics and Integrative Biology, Department of Microbial Biotechnology, Sukhdev Vihar, Mathura Road, New Delhi - 110 025, India.
authors.forename: Hemant K
authors.initials: HK
authors.lastname: Gautam
authors.affiliation: Department of Dermatology, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi - 110 025, India.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Garg
keywords: Acne; antibiotics; azithromycin; benzoyl peroxide; clindamycin; levofloxacin; minocycline; resistance