George E. Kenny

Association of Mycoplasma genitalium with nongonococcal urethritis in heterosexual men.

Chlamydia trachomatis and Neisseria gonorrhoeae are universally acknowledged as urethral pathogens, yet the etiology in the majority of cases of urethritis is unclear. Our case-control study assessed the association of Mycoplasma genitalium, Ureaplasma urealyticum, and other potential pathogens with acute nongonococcal urethritis (NGU) in heterosexual men presenting to an urban sexually transmitted diseases clinic. M. genitalium was detected in 27 (22%) of 121 NGU case patients and in 5 (4%) of 117 control subjects (P<.01). Although C. trachomatis was detected in 36 (30%) of 121 NGU case patients and in 4 (3%) of 117 control subjects (P<.01), only 3 men with NGU were infected with both C. trachomatis and M. genitalium. U. urealyticum was not associated with NGU. By multivariate analyses, controlling for age, race, history of prior urethritis, and chlamydial infection, M. genitalium was associated with a 6.5-fold increased risk of urethritis (95% confidence interval, 2.1-19.5), which supports a role of this organism in the etiology of NGU.

Susceptibilities of Mycoplasma hominis, M. pneumoniae, and Ureaplasma urealyticum to GAR-936, Dalfopristin, Dirithromycin, Evernimicin, Gatifloxacin, Linezolid, Moxifloxacin, Quinupristin-Dalfopristin, and Telithromycin Compared to Their Susceptibilities to Reference Macrolides, Tetracyclines, and Quinolones

ABSTRACT The susceptibilities of Mycoplasma hominis,Mycoplasma pneumoniae, and Ureaplasma urealyticum to eight new antimicrobial agents were determined by agar dilution.M. pneumoniae was susceptible to the new glycylcycline GAR-936 at 0.12 μg/ml and evernimicin at 4 μg/ml, but it was resistant to linezolid. It was most susceptible to dirithromycin, quinupristin-dalfopristin, telithromycin, reference macrolides, and josamycin. M. hominis was susceptible to linezolid, evernimicin, and GAR-936. It was resistant to macrolides and the ketolide telithromycin but susceptible to quinupristin-dalfopristin and josamycin. U. urealyticum was susceptible to evernimicin (8 to 16 μg/ml) and resistant to linezolid. It was less susceptible to GAR-936 (4.0 μg/ml) than to tetracycline (0.5 μg/ml). Telithromycin and quinupristin-dalfopristin were the most active agents against ureaplasmas (0.06 μg/ml). The new quinolone gatifloxacin was active against M. pneumoniae and M. hominis at 0.12 to 0.25 μg/ml and active against ureaplasmas at 1.0 μg/ml. The MICs of macrolides were markedly affected by pH, with an 8- to 32-fold increase in the susceptibility of M. pneumoniae as the pH increased from 6.9 to 7.8. A similar increase in susceptibility with increasing pH was also observed with ureaplasmas. Tetracyclines showed a fourfold increase of activity as the pH decreased 1 U, whereas GAR-936 showed a fourfold decrease in activity with a decrease in pH.

Epidemiology of viral and mycoplasmal agents associated with childhood lower respiratory illness in a civilian population.

The incidence of lower respiratory illnesses (croup, bronchiolitis, and pneumonia) reported to the clinic was measured for one year from December 1, 1966, in children under 6 years of age in a representative civilian population in greater Seattle. A total of 574 illnesses were recorded in 10,933 children, suggesting an incidence of 52.5 per 1,000 children per year in Seattle. Most illnesses occurred in the fall and winter. Isolation and serologic studies associated 5 groups of respiratory pathogens with 47.5 per cent of the illnesses. They were parainfluenza viruses (15.5 per cent), respiratory syncytial virus (14 per cent), adenovirus (9 per cent), Mycoplasma pneumoniae (7.5 per cent), and influenza viruses (1.5 per cent).

The immune response in immunized and naturally infected rainbow trout (Salmo gairdneri) to Diplostomum spathaceum as detected by enzyme-linked immunosorbent assay (ELISA).

The enzyme-linked immunosorbent assay (ELISA) procedure was modified and adapted for detection of circulating antibodies in rainbow trout (Salmo gairdneri) against metacercariae of the digenean trematode Diplostomum spathaceum, the causative agent for diplostomiasis. Rainbow trout (Salmo gairdneri) were injected with sonicated metacercariae representing 10, 40, and 100 metacercariae per fish. Three weeks after immunization the average titers for trout injected with 10, 40, and 100 metacercariae were 874, 841, and 525, and by six weeks the titers had fallen to 299, 349, and 203, respectively. Nine weeks after initial immunization, two remaining fish initially immunized with 100 metacercariae per fish were injected with a booster of 50 sonicated metacercariae per fish. Four weeks later the average titer was 1204. Serum samples from naturally infected wild fish tested for the presence of circulating antibodies against Diplostomum spathaceum showed 25 of 27 with positive titers.

Isolation of Mycoplasma hominis, T-strains, and cytomegalovirus from the cervix of pregnant women

Abstract Mycoplasma hominis was isolated from 37 of 199 cervical cultures from women attending the prenatal clinic at the University Hospital in Seattle. The isolation rate was higher among Negroes (32 per cent), than among Caucasians (16 per cent). T-strains were isolated from 56 per cent of the pregnant Caucasian women and 75 per cent of the pregnant Negro women. Nearly all (92 per cent) of those who carried M. hominis also carried T-strains. No adverse effect of pregnancy or on the infant from the presence of either M. hominis or T-strains was observed. Both organisms were transmitted to infants of positive mothers (M. hominis to 2 of 11 such infants and T-strains to 4 of 15 such infants). Cytomegalovirus (CMV) was isolated from cervical cultures of 5 of 140 pregnant women. Congenital cytomegalovirus disease or transmission to the infant was not seen in any of these 5 patients. On the other hand, the presence of CMV in the cervix was associated with lower than average birth weight.

Chromosomal DNA Probes for the Identification of Bacteroides Species

We compared 22 Bacteroides species by DNA-DNA homology studies using the S1 endonuclease method. None of the currently defined species shared more than 30% DNA homology with any other species examined with the exception of B. buccae and B. capillus (which along with B. pentosaceus are now considered a single species), which shared 86% of their DNA sequences. Two clusters showed weak genetic relationships, with DNA homology greater than 10%. The first cluster included B. coporis, B. disiens, B. bivius, B. intermedius and B. melaninogenicus. The second cluster included B. fragilis, B. eggerthii, B. ovatus, B. thetaiotaomicron and B. uniformis. Five of the oral species, B. asaccharolyticus, B. gingivalis, B. loescheii, B. intermedius and B. melanogenicus, were chosen for study as whole chromosomal probes in dot blot assays. These were tested against 243 clinical strains biochemically identified as Bacteroides species. The DNA probes correctly identified 94% of the clinical strains. DNA probe and biochemical identification was 100% for two of the five species. In contrast, only 86% of the strains biochemically identified as B. intermedius were identified by the DNA probe. The DNA probes gave a species identification to seven strains which could not be biochemically identified.

Standardized Methods and Quality Control Limits for Agar and Broth Microdilution Susceptibility Testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum

ABSTRACT An international multilaboratory collaborative study was conducted to develop standard media and consensus methods for the performance and quality control of antimicrobial susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum using broth microdilution and agar dilution techniques. A reference strain from the American Type Culture Collection was designated for each species, which was to be used for quality control purposes. Repeat testing of replicate samples of each reference strain by participating laboratories utilizing both methods and different lots of media enabled a 3- to 4-dilution MIC range to be established for drugs in several different classes, including tetracyclines, macrolides, ketolides, lincosamides, and fluoroquinolones. This represents the first multilaboratory collaboration to standardize susceptibility testing methods and to designate quality control parameters to ensure accurate and reliable assay results for mycoplasmas and ureaplasmas that infect humans.

Isolation of mycoplasmas and bacteria from the blood of postpartum women

Mycoplasmas and/or bacteria were recovered from the blood cultures of 26 (20.8%) of 125 febrile postpartum women. Genital mycoplasmas were recovered from 16 (12.8%) of the 125 febrile women and from none of 60 afebrile postpartum women (p less than 0.005). The presence of mycoplasmaemia was associated with a young age, primigravidity, and nulliparity. The isolation of organisms from the blood was also associated with fever during labor, internal monitor use, and a cesarean delivery.

CLOSE SEROLOGICAL RELATIONSHIP BETWEEN GLYCOLIPIDS OF MYCOPLASMA PNEUMONIAE AND GLYCOLIPIDS OF SPINACH

The major complement-fixing antigens of Mycoplasma pneumoniae are found in the lipid fraction.1 The serologically active lipid components are largely glyceroglycolipids containing both glucose and ga lac to~e .~ ,~ Plackett and associates3 have shown that as many as seven distinct serologically active components may be demonstrated. Two of the major components were characterized as digalactosyl diglyceride and trigalactosyl diglyceride. Several other glycolipid fractions were obtained that contained both glucose and galactose. Our results generally support these findings. Since Plackett and co-workers3 also showed that a digalactosyl diglyceride preparation from spinach cross-reacted with animal antisera to M . pneumoniae, we sought to confirm these results with commercial digalactosyl diglyceride. This preparation proved to have poor serological activity against the human antisera it was tested against. Therefore, we sought to fractionate digalactosyl diglyceride from spinach to determine whether the spinach glycolipid might differ serologically from commercial digalactosyl diglyceride. In the course of the fractionation of spinach chloroplast lipids, we observed an additional glycolipid component with migration characteristics on thin-layer chromatography similar to that of presumed trigalactosyl diglyceride from M . pneumoniae. This compound was found to have substantial serological activity against human convalescent sera from patients with M . pneumoniae pneumonia and forms the subject of this preliminary report.

HEAT‐LABILITY AND ORGANIC SOLVENT‐SOLUBILITY OF MYCOPLASMA ANTIGENS*

Detection of antibody to mycoplasma in man and animals has been handicapped by a lack of knowledge of the antigens involved. Solvent-soluble C F antigens have been described for M . mycoides’a and M . pneumoniae.3 It is the purpose of this paper to present further data on the extraction of antigens from other mycoplasma species with organic solvents. Heat-lability of mycoplasma antigens was also studied as a guide to the relative stability of these antigens toward chemical fractionation.