16S rDNA PCR analysis of infectious keratitis: a case series.
OBJECTIVE
To discuss the value of polymerase chain reaction (PCR) in the management of bacterial infectious keratitis.


METHODS
Corneal scrapings of four patients with severe infectious keratitis were analysed by culture and PCR of 16S ribosomal DNA (rDNA), followed by direct sequencing of the resulting amplicon. The medical history of the patients included laser-assisted in-situ keratomileusis (LASIK), penetrating keratoplasty (PKP) and trauma.


RESULTS
Using PCR we were able to identify a possible pathogen in all four cases, while bacterial cultures were either negative or did not correspond to the clinical picture. The identified bacteria were a Pseudomonas species, Abiotrophia defectiva, Stenotrophomonas maltophilia and Porphyromonas gingivalis.


CONCLUSIONS
Analysis of corneal scrapings by 16S rDNA PCR should be considered as a supplement to standard microbiological procedures. However, the results of this relatively new method have to be interpreted carefully.
Department of Ophthalmology, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden. thiemo.rudolph@web.de
Thiemo
T
Rudolph
Christina
C
Welinder-Olsson
Lena
L
Lind-Brandberg
Ulf
U
Stenevi
D000328:Adult; D000368:Aged; D015373:Bacterial Typing Techniques; D003315:Cornea / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis*; D004275:DNA, Ribosomal / Q000737:chemistry*; D015818:Eye Infections, Bacterial / Q000382:microbiology*; D005260:Female; D006095:Gram-Positive Cocci / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007634:Keratitis / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000302:isolation & purification; D011549:Pseudomonas / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D020615:Stenotrophomonas maltophilia / Q000235:genetics / Q000302:isolation & purification
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S