The Effect Of Antimicrobials On P. Acnes Biofilm Formation

4.0 Discussion Despite the ubiquitous presence of P. acnes on human tissues, information about its role in human diseases still remains debated (Portillo et al. 2013). Several studies have reported the ability of this organism to act as an opportunistic pathogen, with suggested pathological roles in a variety of inflammatory diseases such as acne vulgaris and discitis (Achermann et al. 2014, Rollason et al. 2013). Studies have revealed that this organism comprises of several distinct evolutionary clades which have been further discriminated based on Multilocus sequence typing into phylogenetically distinct clusters (type IA, IB, IC, II, and III) (Kilian et al. 2012). These clades differ in their production of virulence factors which can†¦show more content†¦Resistance patterns comprise both isolates with moderately increased MICs and isolates with very high MICs (Oprica et al. 2006). In this study, low level resistance to vancomycin due to a slightly increased MIC (2  µg/ml) was observed in type IB (90) isolate and also reduced susceptibility to tetracycline due to a slightly increased MIC (2  µg/ml) was observed in types IA1 (35), IA1 (56), and AC (7) test isolates. Literatures have reported the emergence of resistance of types (IA and IB) associated with moderate to severe acnes (Oprica et al. 2004, Nord and Oprica 2006). Resistance to tetracycline occurs due to a single G-C transition in the 16S rRNA of the small ribosomal subunit in P. acnes (Ross et al. 1998, Nonaka et al. 2005). Nakase et al. (2014) reported that tetracycline resistance can also arise as a result of mutation of drug binding sites, ribosomal protection or increased efflux pump activities Resistance of planktonic acne isolates to vancomycin has not been reported (Oprica and Nord 2005, Piggott et al. 2016). Tetracycline has been reported to penetrate bacterial cell wall by an energy dependent process. It then binds reversibly to the 30S ribosomal subunit thus preventing the attachment of amino acyl-tRNA to the ribosomal acceptor A-site in the RNA-ribosome complex (Kohanski et al. 2010) was bacteriostatic at all concentrations tested in the MBC assay.