Ocular pathogen or commensal: a PCR-based study of surface bacterial flora in normal and dry eyes.

Purpose: To compare the bacterial population of the ocular surface of normal and dry eye subjects using conventional culture and 16S rDNA PCR.

Methods: Ninety-one subjects were classified as normal (n = 57) or dry eye (n = 34) by using tear break-up time, McMonnies survey, goblet cell density, and meibomian gland assessment. Conventional bacterial culture and broad-range 16S rDNA PCR, cloning, and DNA sequencing were used for bacterial identification.

Purulent rhinitis and otitis caused by Pseudomonas aeruginosa in sheep showered with contaminated 'shower wash'.

Three crossbred lowland ewes developed a severe purulent rhinitis and another three ewes developed a severe purulent otitis externa/media after being showered with a wash that had been used 24 to 48 hours before on a separate group of Cheviot ewes with lesions of dermatitis. Pseudomonas aeruginosa was isolated in pure growth from the aural and nasal abscesses and also from the dermatitis lesions. Extended antibiotic susceptibility testing and the random amplification of polymorphic DNA indicated that a single clonal type was associated with the rhinitis and otitis and with the dermatitis, providing strong evidence of an epidemiological link between the lesions of dermatitis and the aural and nasal abscesses through the use of the contaminated 'shower wash'.

False identification of Coccidioides immitis: do molecular methods always get it right?

rRNA sequence analysis of a partial region of the 18S and 5.8S-internal transcribed spacer 2 (ITS2) region of Chrysosporium keratinophilum highlights its potential molecular misidentification as Coccidioides immitis. Molecular identification of medically important fungi should not be based solely on sequence analysis of the 18S rRNA gene but should be confirmed by sequence analysis of an additional rRNA gene locus, such as the ITS region(s).

Rapid characterization of the genomovars of the Burkholderia cepacia complex by PCR-single-stranded conformational polymorphism (PCR-SSCP) analysis.

Four polymerase chain reaction (PCR) primer pairs (A-D), specific for the Burkholderia cepacia complex of organisms were designed to encompass the entire gene (approximately 1300 bp) from sequence alignments of the rec A operon of B. cepacia. Genomic bacterial DNA from type strains and wild-type B.

A simple and sensitive method to extract bacterial, yeast and fungal DNA from blood culture material.

This study investigated the various commercially available kits and 'in-house' methods to extract DNA from Gram-negative and Gram-positive bacteria, yeast and fungal agents in commonly employed blood culture material. The main methods investigated were as follows; Qiagen QIAmp Blood kit, Roche high PCR template preparation kit, Puregene DNA extraction kit, boiling, glass beads/sonication and wash/alkali/heat lysis. The results indicated that a simple wash/alkali/heat lysis method was the most sensitive, reproducible, simple and cost-effective extraction method.