title: A study on the characterization of Propionibacterium acnes isolated from ocular clinical specimens.
abstract: OBJECTIVE
  There are only a few reports available on characterization of Propionibacterium acnes isolated from various ocular clinical specimens. We undertook this study to evaluate the role of P. acnes in ocular infections and biofilm production, and also do the phylogenetic analysis of the bacilli.
  
  
  METHODS
  One hundred isolates of P. acnes collected prospectively from ocular clinical specimens at a tertiary care eye hospital between January 2010 and December 2011, were studied for their association with various ocular disease conditions. The isolates were also subjected to genotyping and phylogenetic analysis, and were also tested for their ability to produce biofilms.
  
  
  RESULTS
  Among preoperative conjunctival swabs, P. acnes was a probably significant pathogen in one case; a possibly significant pathogen in two cases. In other clinical conditions, 13 per cent isolates were probably significant pathogens and 38 per cent as possibly significant pathogens. The analysis of 16S rRNA gene revealed four different phylogenies whereas analysis of recA gene showed two phylogenies confirming that recA gene was more reliable than 16S rRNA with less sequence variation. Results of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) had 100 per cent concordance with phylogenetic results. No association was seen between P. acnes subtypes and biofilm production.
  
  
  CONCLUSIONS
  RecA gene phylogenetic studies revealed two different phylogenies. RFLP technique was found to be cost-effective with high sensitivity and specificity in phylogenetic analysis. No association between P. acnes subtypes and pathogenetic ability was observed. Biofilm producing isolates showed increased antibiotic resistance compared with non-biofilm producing isolates.
authors.forename: Murali
authors.initials: M
authors.lastname: Sowmiya
authors.affiliation: L&T Microbiology Research Centre, Kamal Nayan Bajaj Institute for Research in Vision & Ophthalmology, Vision Research Foundation, Chennai, India.
authors.forename: Jambulingam
authors.initials: J
authors.lastname: Malathi
authors.forename: Sen
authors.initials: S
authors.lastname: Swarnali
authors.forename: Jeyavel Padma
authors.initials: JP
authors.lastname: Priya
authors.forename: Kulandai Lily
authors.initials: KL
authors.lastname: Therese
authors.forename: Hajib N
authors.initials: HN
authors.lastname: Madhavan
mesh_terms: D018441:Biofilms; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004352:Drug Resistance, Microbial / Q000235:genetics; D005123:Eye / Q000382:microbiology* / Q000473:pathology; D005128:Eye Diseases / Q000235:genetics / Q000382:microbiology* / Q000473:pathology; D005838:Genotype; D006801:Humans; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D011425:Propionibacterium acnes / Q000302:isolation & purification* / Q000472:pathogenicity; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D011938:Rec A Recombinases