title: High-resolution genotyping of Pseudomonas aeruginosa strains linked to acute post cataract surgery endophthalmitis outbreaks in India.
abstract: BACKGROUND
  Investigation of two independent outbreaks of post cataract surgery endophthalmitis identified the reservoir of epidemic strains of P. aeruginosa.
  
  
  METHODS
  Patient isolates cultured from vitreous fluid of all the nine cases and from the peripheral devices of phacoemulsification machine were subjected to high-resolution Fluorescent Amplified Fragment Length Polymorphism (FAFLP) analysis.
  
  
  RESULTS
  FAFLP based genotyping of the isolates confirmed nosocomial transmission. Although biochemical characterization and antibiotic susceptibility profiles grouped all the isolates together, FAFLP based genotyping revealed that, all the outbreak isolates were derived from 2 different strains, with independent origins. One group of isolates was traced to phacoprobe and the second one to the internal tubing system of the phacoemulsification machine used in cataract surgery. In silico analysis indicated possible evolution in both the clusters of P. aeruginosa isolates due to genetic polymorphisms. The polymorphisms were mapped to gene products (cell envelope, outer membrane proteins) possibly having significant role in pathogenesis.
  
  
  CONCLUSIONS
  The present study is probably the first one to apply FAFLP typing successfully to investigate outbreaks of postoperative endophthalmitis (POE) in an ophthalmic setting, which was able to identify the source, and helped to make rational decisions on sterilization procedures that halted more cases of infection in these hospitals.
authors.affiliation: Pathogen Evolution Group, Centre for DNA Fingerprinting and Diagnostics (CDFD), Nacharam, Hyderabad, India. prashant@cdfd.org.in
authors.forename: Prashanth
authors.initials: P
authors.lastname: Kenchappa
authors.forename: Virender S
authors.initials: VS
authors.lastname: Sangwan
authors.forename: Niyaz
authors.initials: N
authors.lastname: Ahmed
authors.forename: K Rajender
authors.initials: KR
authors.lastname: Rao
authors.forename: Avinash
authors.initials: A
authors.lastname: Pathengay
authors.forename: Annie
authors.initials: A
authors.lastname: Mathai
authors.forename: Tarannum
authors.initials: T
authors.lastname: Mansoori
authors.forename: Taraprasad
authors.initials: T
authors.lastname: Das
authors.forename: Seyed E
authors.initials: SE
authors.lastname: Hasnain
authors.forename: Savitri
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000208:Acute Disease; D001483:Base Sequence; D002386:Cataract / Q000382:microbiology*; D002387:Cataract Extraction / Q000009:adverse effects*; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D017931:DNA Primers; D004196:Disease Outbreaks; D009877:Endophthalmitis / Q000453:epidemiology / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D009873:Operating Rooms; D011552:Pseudomonas Infections / Q000453:epidemiology*; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015183:Restriction Mapping; D014822:Vitreous Body / Q000382:microbiology*
chemical_list: D017931:DNA Primers; D004247:DNA