title: N-chlorotaurine and its analogues N,N-dichloro-2,2-dimethyltaurine and N-monochloro-2,2-dimethyltaurine are safe and effective bactericidal agents in ex vivo corneal infection models.
abstract: OBJECTIVE
  N-chlorotaurine (NCT) and its analogues N-monochloro-2,2-dimethyltaurine (NVC-612) and N-dichloro-2,2-dimethyltaurine (NVC-422) are new anti-infectives for topical treatment for conjunctivitis. The aim of this study was to show that these compounds are safe in an EpiOcular model and effective in corneas infected ex vivo.
  
  
  METHODS
  Corneal buttons were excised from porcine eyes. In 183 of the 229 corneas, erosion and artificial superficial stromal incision were induced. They were bathed in suspensions of Pseudomonas aeruginosa or Staphylococcus aureus for 24 hr at 37°C and incubated in solutions of the test substances at 37°C and pH 7.1. Subsequently, they were subjected to histology (n = 20) or homogenized followed by quantitative bacterial cultures (n = 209). Ocular irritation was tested using the EpiOcular™ tissue system (MatTek Corporation).
  
  
  RESULTS
  Bacterial accumulations were detected histologically both on the corneal surface and also in the anterior third of the stroma of incised corneal buttons. All three test compounds at a concentration of 55 mm (equals 1% NCT) reduced the bacterial counts of P. aeruginosa and S. aureus by approximately 5 log10 after 60- and 120-min incubation, respectively. Significant killing was observed as early as after 5-min incubation. Also intrastromal bacteria were inactivated. In the EpiOcular™ tissue model, NCT, NVC-422 and NVC-612 had no or very low potential to irritate corneal tissue.
  
  
  CONCLUSIONS
  N-chlorotaurine, NVC-422 and NVC-612 are non-irritating in cornea and kill P. aeruginosa and S. aureus, even following penetration into the deeper corneal stromal layers.
authors.affiliation: Department of Ophthalmology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Teuchner
authors.forename: Christian
authors.initials: C
authors.lastname: Eitzinger
authors.forename: Matthias
authors.initials: M
authors.lastname: Lutz
authors.forename: Thomas
authors.initials: T
authors.lastname: Hager
authors.forename: Eduard
authors.initials: E
authors.lastname: Schmid
authors.forename: Nikolaos E
authors.initials: NE
authors.lastname: Bechrakis
authors.forename: Meghan
authors.initials: M
authors.lastname: Zuck
authors.forename: Andreas
authors.initials: A
authors.lastname: Jekle
authors.forename: Dmitri
authors.initials: D
authors.lastname: Debabov
authors.forename: Mark
authors.initials: M
authors.lastname: Anderson
authors.forename: Markus
authors.initials: M
authors.lastname: Nagl
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000633:toxicity; D015169:Colony Count, Microbial; D003315:Cornea / Q000382:microbiology / Q000473:pathology; D004195:Disease Models, Animal; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D013552:Swine; D013654:Taurine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000633:toxicity; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; C573019:N-monochloro-2,2-dimethyltaurine; D013654:Taurine; C043410:N-chlorotaurine; C560851:NVC-422