116 cystic fibrosis patients were observed, by monthly examinations over an eight-month period, to investigate the importance of non-bacterial respiratory infections (NBI) in exacerbations of the respiratory disease. Sputum was examined for bacteria, and serum investigated for antibody response against virus, mycoplasma and chlamydia and for antibodies against Pseudomonas aeruginosa. During this period each patient had, on an average, 2.9 exacerbations of which 76% were associated with bacteria, most frequently P. aeruginosa (51%), and 20% with NBI, although bacteria were also present in most of these cases. No etiology was established in 18% of the exacerbations. The NBI were caused by respiratory syncytial virus (RSV) (9%), parainfluenza virus (5%), influenza virus (3.6%), adenovirus (2.4%), mycoplasma (0.6%) and chlamydia (0.6%). The incidence of exacerbations was higher in patients with chronic P. aeruginosa infections. RSV infections were more common in patients who developed chronic P. aeruginosa infection during the study period, and RSV infections were frequently associated with a rise of P. aeruginosa antibodies in patients who harboured these bacteria. The important role of NBI as mediators of onset of chronic P. aeruginosa infections in cystic fibrosis patients is suggested.

No abstract

We have used the polymerase chain reaction to detect Mycoplasma genitalium in artificially seeded human throat swab samples as well as in clinical material. On the basis of the published nucleotide sequence of the M. genitalium 140-kDa adhesin gene, primers were chosen to produce an amplified fragment of 281 bp. Five different previously isolated strains, including the type strain of M. genitalium, could all be detected by the polymerase chain reaction, and DNAs from other mycoplasmal and bacterial species yielded negative results. The detection limits were estimated to be approximately 50 organisms by inspection of ethidium bromidestained agarose gels and 4 organisms when a biotinylated oligonucleotide probe was used in filter hybridization. The amplified DNA fragments were subjected to restriction enzyme analysis. DNAs from the five different isolates all possessed EcoRI, SspI, AluI, Sau3AI, and DdeI restriction sites, as predicted from the published sequence. A total of 150 urogenital swabs collected from 100 patients for culturing of Chiamydia trachomatis were tested for the presence of M. genitalium DNA. Ten samples from eight patients were found positive. The amplified DNA fragments from all of our clinical samples possessed the AluI, Sau3AI, and DdeI restriction sites, but three samples from two patients did not contain the SspI site and none of the samples contained the EcoRI site.

No abstract

Mycoplasma genitalium is a human mycoplasma species which, on the basis of detection by PCR, has been incriminated as a cause of nongonococcal urethritis. Previously, only two strains from the urogenital tract and five strains from extragenital sites have been isolated. We have developed a method for the isolation of this fastidious microbe. M. genitalium from PCR-positive urethral specimens was initially propagated in Vero cell cultures grown in serum-free medium supplemented with Ultroser HY serum substitute. Growth was monitored by PCR. The M. genitalium strains grown in cell cultures could subsequently be subcultured in modified Friis's FF broth medium. Several passages in broth medium were required before growth on agar medium was attained. A total of 11 urethral specimens positive for M. genitalium by PCR from male patients with urethritis were investigated. Six strains were adapted to growth in broth medium, and four of these strains were cloned. Three specimens were overgrown by other mycoplasmas during propagation in the cell cultures. In only two PCR-positive specimens was propagation of M. genitalium unsuccessful. The use of cell culture combined with PCR monitoring of mycoplasmal growth may prove to be more widely applicable for the isolation of other fastidious mollicutes.