The prevalence rates of Mycoplasma genitalium infections and coinfections with other sexually transmitted organisms and the frequency of a macrolide antibiotic resistance phenotype were determined in urogenital specimens collected from female and male subjects enrolled in a multicenter clinical study in the United States. Specimens from 946 subjects seeking care from seven geographically diverse clinical sites were tested for M. genitalium and for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Sequencing was used to assess macrolide antibiotic resistance among M. genitalium-positive subjects. M. genitalium prevalence rates were 16.1% for females and 17.2% for males. Significant risk factors for M. genitalium infections were black race, younger age, non-Hispanic ethnicity, and female symptomatic status. Female M. genitalium infections were significantly more prevalent than C. trachomatis and N. gonorrhoeae infections, while the M. genitalium infection rate in males was significantly higher than the N. gonorrhoeae and T. vaginalis infection rates. The macrolide-resistant phenotype was found in 50.8% of females and 42% of males. These results show a high prevalence of M. genitalium single infections, a lower prevalence of coinfections with other sexually transmitted organisms, and high rates of macrolide antibiotic resistance in a diverse sample of subjects seeking care across a wide geographic area of the United States.

To date, the clinical pharmacology of large intravenous doses of azithromycin has not been described. In the present study, single 2-h intravenous infusions of 1, 2, and 4 g of azithromycin were administered to three parallel groups (in each group, six received active drug and two received placebo) of healthy male subjects. Toleration (assessed by scores of subject-administered visual analog scale tests spanning 0 [good] to 10 [poor]), safety, pharmacokinetics, and serum motilin levels were monitored for up to 240 h after the start of each intravenous infusion. Mean nausea scores of 0.0, 0.0, 1.0, and 0.5 and abdominal cramping scores of 0.0, 0.0, 0.4, and 0.4 for 12-h periods after doses of 0, 1, 2, and 4 g of azithromycin, respectively, suggested that azithromycin was well tolerated. Because of the standardized 1-mg/ml infusates, all subjects in the 4-g dosing group complained of an urgent need to urinate. There were no consistent trends in endogenous motilin levels throughout the study. The maximum concentration of azithromycin in serum (10 g/ml after a 4-g dose) and the area under the concentration-time curve (82 g ⅐ h/ml after a 4-g dose) were dose related. The mean pharmacokinetic parameters were an elimination half-life of 69 h, total systemic clearance of 10 ml/min/kg, and a volume of distribution at steady state of 33.3 liters/kg. The pharmacokinetic results suggest that the long half-life of azithromycin is due to extensive uptake and slow release of the drug from tissues rather than an inability to clear the drug. Single intravenous doses of up to 4 g of azithromycin in healthy subjects are generally well tolerated, and quantifiable concentrations may persist in serum for 10 days or more.

Background This study evaluated the distribution of macrolide-resistant Mycoplasma genitalium in multiple urogenital specimens collected from women enrolled in a prospective multi-center US clinical study. Methods Four female urogenital specimens (vaginal swab, urine, endocervical swab, ectocervical brush/spatula) collected from each subject were tested using a transcription-mediated amplification (TMA) assay for M. genitalium. TMA-positive specimens were evaluated by reverse transcription-PCR and bi-directional Sanger sequencing of M. genitalium 23S rRNA to identify the presence of macrolide resistance-mediating mutations (MRM) at base positions 2058/2059. Results Of 140 women with one or more TMA-positive specimens, 128 (91.4%) yielded M. genitalium 23S rRNA sequence. MRM were found in 52% of vaginal specimens, 46.3% of urine specimens, 37.8% of endocervical specimens, and 46% of ectocervical specimens. There were 44 unique specimen type/sequence phenotype combinations of M. genitalium infection. The majority (81, 63.3%) of women had single specimen-sequence phenotype (macrolide-susceptible, MRM, or both) infections, while 24 (18.8%) women had multiple specimen-sequence phenotype concordant infections, and 23 (17.9%) women had multiple specimen-sequence phenotype discordant infections. The sensitivity for any single specimen type to detect overall urogenital tract macrolide-resistant M. genitalium infection status was 96.3% for vaginal swab samples, 82.6% for urine samples, 70.8% for endocervical swab samples, and 82.1% for ectocervical brush/spatula liquid Pap samples. Conclusions The distribution of M. genitalium infections in female urogenital tract specimens is highly complex, with multiple phenotypic combinations of the organism infecting a significant proportion of women at different anatomic specimen collection sites. Vaginal swab sampling yielded the highest sensitivity for identifying women with macrolide resistant M. genitalium urogenital tract infections.

Mucus‐secreting epithelia protect marine gastropods from abrasive particles and microbes in seawater. We studied the morphology and function of the epithelium in the giant keyhole limpet Megathura crenulata. All exposed surfaces of the limpets were covered by a mucus‐secreting, simple columnar epithelium, in which most cells on the sole of the foot bore cilia, while the majority of cells on the side of the foot and three mantle regions bore microvilli. None of the coatings had antibacterial properties. The epithelium of the foot was distinct from that of other regions, in that the mucus secreted was used for locomotion and was left behind as the limpet moved. The glycocalyx bound to the microvilli of the mantle cells appeared to be clean in visual and SEM examinations, and attempts to enhance the binding of inert particles and bacteria were unsuccessful. Because studies have shown that standard tissue processing may cause artifactual shrinkage of mucous layers, cryostat sections and additives to standard fixatives were tested, but we found no change in the thickness of the mucous layers of the limpets compared to routinely processed tissues. Sloughing of the glycocalyx in vertebrate systems removes bound microbes, and alterations of the glycocalyx layers are associated with disease conditions. Sloughing of the glycocalyx on limpets was rarely observed. In one case, the outer mantle of the limpet was covered with silt and the glycocalyx appeared to be detaching. This process could be experimentally induced by dousing the outer mantle with talc particles. The types of secretory cells producing the mucus in each region of the skin were characterized using standard histological stains and lectin staining. Because analysis was hampered by their small size, classification of the types of secretory cells was based on TEM descriptions of granule morphology, which allowed for comparison to the secretory cells described from skin of the abalone. The possible roles of the numerous secretions, and the mechanisms of mucus production and loss, are compared to what is known in vertebrate systems and to our relative lack of knowledge regarding invertebrate systems.

Introduction This study evaluated the prevalence and anatomical distribution of Mycoplasma genitalium (Mgen) 23s rRNA mutations (23s-MTs) conferring macrolide resistance among male and female subjects enrolled in a prospective multi-site US clinical study. Methods Specimens obtained from symptomatic and asymptomatic men and women enrolled from 7 diverse US clinical sites, including obstetrics and gynaecology, family planning, public health, and sexually transmitted disease clinics, were tested using a research TMA assay for Mgen (Hologic, Inc.) on the DTS System or TIGRIS DTS System. Samples positive for Mgen by TMA were evaluated by nested PCR or RT-PCR and Sanger sequencing of Mgen 23S rRNA to identify the presence of macrolide resistance mutations at position 2058 (A2058G, A2058C, A2058T) or position 2059 (A2059G). Results Of 50 male subjects with Mgen 23s rRNA sequence results, 21 (42%) contained 23s-MTs. Slightly more 23s-MTs were found in urethral swabs vs male urine samples (44.8% vs 36.7%, respectively). For female subjects, 65 of 128 (50.8%) harboured 23s-MTs, with higher prevalence found in vaginal swab samples (50.2%) compared to urine (46%), Thinprep liquid Pap (41.7%), and endocervical swabs (37.8%). Sequencing of samples collected from anatomically distinct female urogenital sites (vagina, cervix, urine) revealed 18 of 35 (51.4%) subjects had a unique complement of Mgen 23s-MT and/or wild-type sequences at each anatomic site. For male subjects with both urine and urethral swab samples, 3 of 9 (33.3%) subjects had unique Mgen 23s-MT/WT sequences in each sample type. Conclusion Mgen strains harbouring 23s rRNA-mediated macrolide resistance phenotypes were highly prevalent in this US cohort of male and female subjects. Detection of different macrolide-resistant Mgen strains in samples collected from different anatomical locations suggests that previous estimates for resistance rates that relied on a single anatomical site sample collection may have underestimated the extent of Mgen macrolide resistance in the population.