Acyclovir and transmission of HIV-1 from persons infected with HIV-1 and HSV-2.

BACKGROUND: Most persons who are infected with human immunodeficiency virus type 1 (HIV-1) are also infected with herpes simplex virus type 2 (HSV-2), which is frequently reactivated and is associated with increased plasma and genital levels of HIV-1. Therapy to suppress HSV-2 reduces the frequency of reactivation of HSV-2 as well as HIV-1 levels, suggesting that suppression of HSV-2 may reduce the risk of transmission of HIV-1. METHODS: We conducted a randomized, placebo-controlled trial of suppressive therapy for HSV-2 (acyclovir at a dose of 400 mg orally twice daily) in couples in which only one of the partners was seropositive for HIV-1 (CD4 count, > or = 250 cells per cubic millimeter) and that partner was also infected with HSV-2 and was not taking antiretroviral therapy at the time of enrollment. The primary end point was transmission of HIV-1 to the partner who was not initially infected with HIV-1; linkage of transmissions was assessed by means of genetic sequencing of viruses. RESULTS: A total of 3408 couples were enrolled at 14 sites in Africa. Of the partners who were infected with HIV-1, 68% were women, and the baseline median CD4 count was 462 cells per cubic millimeter. Of 132 HIV-1 seroconversions that occurred after randomization (an incidence of 2.7 per 100 person-years), 84 were linked within couples by viral sequencing: 41 in the acyclovir group and 43 in the placebo group (hazard ratio with acyclovir, 0.92, 95% confidence interval [CI], 0.60 to 1.41; P=0.69). Suppression with acyclovir reduced the mean plasma concentration of HIV-1 by 0.25 log(10) copies per milliliter (95% CI, 0.22 to 0.29; P<0.001) and the occurrence of HSV-2-positive genital ulcers by 73% (risk ratio, 0.27; 95% CI, 0.20 to 0.36; P<0.001). A total of 92% of the partners infected with HIV-1 and 84% of the partners not infected with HIV-1 remained in the study for 24 months. The level of adherence to the dispensed study drug was 96%. No serious adverse events related to acyclovir were observed. CONCLUSIONS: Daily acyclovir therapy did not reduce the risk of transmission of HIV-1, despite a reduction in plasma HIV-1 RNA of 0.25 log(10) copies per milliliter and a 73% reduction in the occurrence of genital ulcers due to HSV-2. (ClinicalTrials.gov number, NCT00194519.)

The psychosocial impact of serological herpes simplex type 2 testing in an urban HIV clinic.

BACKGROUND/OBJECTIVES: Herpes simplex virus type 2 (HSV-2) is a common infection among HIV infected people. HSV type specific serologies permit the diagnosis of previously unrecognised HSV-2 infection. While substantial psychosocial morbidity has been associated with a clinical diagnosis of genital herpes, the burden associated with a serological diagnosis of HSV-2 is unclear. This study prospectively measured the psychosocial response to a new serological HSV-2 diagnosis in patients receiving care at an urban HIV clinic. METHODS: At entry, sera were tested for HSV-1 and HSV-2 antibodies by western blot. Participants completed a 90 item psychosocial and life quality questionnaire at enrollment, and at 2 weeks, 3 months, and 6 months after receiving test results. RESULTS: Of 248 HIV infected participants, 172 (69.4%) were HSV-2 seropositive and 116 (67.4%) seropositive people did not have a previous history of genital herpes. After correction for multiple comparisons, no statistically significant differences were detected on the psychosocial and life quality scales between those who received a new HSV-2 serological diagnosis compared with those who were HSV-2 seropositive with a history of genital herpes, or those who tested HSV-2 seronegative. Additionally, no significant changes in scores were observed during follow up. CONCLUSIONS: HSV-2 was a common but often unrecognised infection in this urban HIV clinic and participants coped well with a positive HSV-2 result. Concerns about psychosocial burden should not deter serological testing for HSV-2. Given the epidemiological and clinical interaction between HSV-2 and HIV, these data support routine HSV-2 testing of HIV infected people.

Avoiding risky sex partners: perception of partners' risks v partners' self reported risks.

BACKGROUND: Key strategies advocated for lowering personal risk of sexual exposure to STD/HIV include having fewer partners and avoiding risky partners. However, few studies have systematically examined how well people can actually discern their sex partners' risk behaviours. METHODS: We conducted face to face interviews with 151 heterosexual patients with gonorrhoea or chlamydial infection and 189 of their sex partners. Interviews examined the patients' perceptions of their sex partners' sociodemographic characteristics and risk behaviours. Patients' perceptions of partners were then sociometrically compared for agreement with partner self reports, using the kappa statistic for discrete variables and concordance correlation for continuous variables. RESULTS: Agreement was highest for perceived partner age, race/ethnicity, and duration of sexual partnership; and lowest for knowledge of partner's work in commercial sex, number of other sex partners, and for perceived quality of communication within the partnership. Index patients commonly underestimated or overestimated partners' risk characteristics. Reported condom use was infrequent and inconsistent within partnerships. CONCLUSION: Among people with gonorrhoea or chlamydial infection, patients' perceptions of partners' risk behaviours often disagreed with the partners' self reports. Formative research should guide development and evaluation of interventions to enhance sexual health communication within partnerships and within social networks, as a potential harm reduction strategy to foster healthier partnerships.

Quantitative culture of Chlamydia trachomatis: relationship of inclusion-forming units produced in culture to clinical manifestations and acute inflammation in urogenital disease.

The relationship of Chlamydia trachomatis inclusion-forming units in quantitative culture to clinical manifestations and inflammation in urogenital disease was assessed in 1179 patients attending a sexually transmitted diseases clinic. In women, greater inclusion-forming unit counts were associated with cervical mucopus (3000 vs. 450 ifu), amount and character of cervical discharge, > or =30 polymorphonuclear cells (PMNL) per high-power field (hpf) on Gram stain (2050 vs. 320 ifu), and diagnoses of mucopurulent cervicitis (MPC; 2550 vs. 300 ifu) and pelvic inflammatory disease (PID; 3000 vs. 578 ifu). In men, greater inclusion-forming unit counts were associated with urethral discharge (85 vs. 44 ifu), amount and character of discharge, and > or =10 PMNL/hpf (95 vs. 50 ifu). These associations persisted on multivariate analysis. Thus, chlamydial replication is associated with MPC and PID in women, urethritis in men, and inflammation in both. Since infections with high inclusion counts may be the most transmissible, identification and treatment of patients with these chlamydia-associated syndromes is important in control programs.

Partner management for gonococcal and chlamydial infection: expansion of public health services to the private sector and expedited sex partner treatment through a partnership with commercial pharmacies.

BACKGROUND: Public health partner notification (PN) services currently affect only a small minority of patients with gonorrhea or chlamydial infection and new approaches to PN are needed. OBJECTIVES: To expand PN for gonorrhea and chlamydial infection to private sector patients and to assess the feasibility of treating sex partners through commercial pharmacies. METHODS: Selected patients were offered PN assistance and were randomly offered medication to deliver to their partners. RESULTS: Providers permitted the health department to contact 3613 (91%) of 3972 potentially eligible patients, and 1693 (67%) of 2531 successfully contacted patients consented to interview. Of these, 1095 (65%) reported at least one untreated partner. Most patients (90%) wished to notify partners themselves. Patients were more likely to have partners who had not yet been treated and to request PN assistance if they had more than one sex partner in the preceding 60 days or a partner they did not anticipate having sex with in the future. These two factors characterized 49% of all patients interviewed, 70% of those with a partner that was untreated 7 or more days after index patient treatment, and 83% of those accepting PN assistance. Among 458 randomly selected patients with untreated partners at time of study interview, 346 (76%) agreed to deliver treatment to a partner. Of these, most (266) chose to obtain medication for a partner at a pharmacy, of whom 223 (84%) successfully did so. CONCLUSION: A substantial minority of private sector patients have untreated partners more than 7 days after their own treatment; some need help with PN, but most will agree to deliver medication to partners themselves.

Gonorrhea in the HIV era: a reversal in trends among men who have sex with men.

OBJECTIVES: Gonorrhea cases among men who have sex with men (MSM) declined in the early years of the HIV epidemic. We evaluated more recent trends in gonorrhea among MSM through the Centers for Disease Control and Prevention's Gonococcal Isolate Surveillance Project. METHODS: Isolates and case information were collected from 29 US sexually transmitted disease (STD) clinics. Gonococcal urethritis cases among MSM were compared with those among heterosexual men, and cases among MSM in 1995 to 1999 were compared with earlier MSM cases. RESULTS: Of 34,942 cases, the proportion represented by MSM increased from 4.5% in 1992 to 13.2% in 1999 (P < .001). Compared with heterosexuals, MSM were older, more often White, and more often had had gonorrhea previously, although fewer had had gonorrhea in the past year. MSM with gonorrhea in 1995 to 1999 were slightly older than those with gonorrhea in 1992 to 1994, and a higher proportion had had gonorrhea in the past year. CONCLUSIONS: MSM account for an increasing proportion of gonococcal urethritis cases in STD clinics. Given recent evidence that gonorrhea may facilitate HIV transmission, these trends demand increased attention to safe sexual behaviors and reducing STDs among MSM.

Urine-based screening for Chlamydia trachomatis in men attending sexually transmitted disease clinics.

BACKGROUND: Nucleic acid-amplified tests for Chlamydia trachomatis are accurate but costly. Screening strategies for asymptomatic men are needed. GOAL: To assess C trachomatis screening strategies for asymptomatic males. STUDY DESIGN: Men attending a sexually transmitted disease clinic were tested for C trachomatis with ligase chain reaction and culture, and for urethral inflammation with urine leukocyte esterase and urethral Gram stain. RESULTS: C trachomatis prevalence was 5.5% among 1,625 asymptomatic men. Ligase chain reaction increased detection by 49% among men without urethral inflammation. An age of younger than 25 years and urethral inflammation were associated with positive ligase chain reaction results. The negative predictive value of urine leukocyte esterase was highest among older men, but urethral Gram stain was equally sensitive in predicting infection regardless of age. An age of younger than 30 years or urethral inflammation identified the highest proportion of infections (92%) and reduced the percentage of men screened by 43%. CONCLUSIONS: Urine ligase chain reaction increased C trachomatis detection, particularly among men without urethral inflammation. Testing all asymptomatic men younger than 30 years is optimal, whereas negative urine leukocyte esterase or urethral Gram stain results in men 30 years or older support no testing.

A randomized trial of ciprofloxacin versus cefixime for treatment of gonorrhea after rapid emergence of gonococcal ciprofloxacin resistance in The Philippines.

From 1994 through 1996-1997, high-level ciprofloxacin resistance (minimum inhibitory concentration [MIC], > or = 4.0 microg/mL) increased from 9% to 49% of gonococcal isolates recovered from consecutive female sex workers in Cebu and Manila, The Philippines (P < .01). During 1996-1997, 105 female sex workers with gonorrhea were prospectively randomized to receive treatment with oral ciprofloxacin, 500 mg, or cefixime, 400 mg, and followed for test of cure. Neisseria gonorrhoeae was reisolated within 28 days after treatment from 1 (3.8%) of 26 women given cefixime versus 24 (32.3%) of 72 women given ciprofloxacin (P < .01). Treatment failure (reisolation of pretreatment auxotype/serovar) occurred in 14 (46.7%) of 30 women infected with strains with MICs of ciprofloxacin > or = 4.0 microg/mL versus 1 (3.6%) of 28 infected by strains with MICs < 4.0 microg/mL (P < .01). High-level, clinically significant gonococcal resistance to ciprofloxacin has rapidly emerged in The Philippines, and spread of fluoroquinolone resistance through commercial sex poses a threat to control of gonorrhea and prevention of human immunodeficiency virus infection and the acquired immunodeficiency syndrome.

Determinants of persistent and recurrent Chlamydia trachomatis infection in young women: results of a multicenter cohort study.

BACKGROUND: Sequelae of genital Chlamydia trachomatis infection in women are more strongly linked to repeat infections than to initial ones, and persistent or subsequent infections foster continued transmission. OBJECTIVE: To identify factors associated with persistent and recurrent chlamydial infection in young women that might influence prevention strategies. METHODS: Teenage and young adult women with uncomplicated C trachomatis infection attending reproductive health, sexually transmitted disease, and adolescent medicine clinics in five US cities were recruited to a cohort study. Persistent or recurrent chlamydial infection was detected by ligase chain reaction (LCR) testing of urine 1 month and 4 months after treatment. RESULTS: Among 1,194 women treated for chlamydial infection, 792 (66.4%) returned for the first follow-up visit, 50 (6.3 %) of whom had positive LCR results. At that visit, women who resumed sex since treatment were more likely to have chlamydial infection (relative risk [RR], 2.0; 95% CI, 1.03-3.9), as were those who did not complete treatment (RR, 3.4; 95% CI, 1.6-7.3). Among women who tested negative for C trachomatis at the first follow-up visit, 36 (7.1%) of 505 had positive results by LCR at the second follow-up visit. Reinfection at this visit was not clearly associated with having a new sex partner or other sexual behavior risks; new infection was likely due to resumption of sex with untreated partners. Overall, 13.4% of women had persistent infection or became reinfected after a median of 4.3 months, a rate of 33 infections per 1,000 person months. CONCLUSIONS: Persistent or recurrent infection is very common in young women with chlamydial infection. Improved strategies are needed to assure treatment of women's male sex partners. Rescreening, or retesting of women for chlamydial infection a few months after treatment, also is recommended as a routine chlamydia prevention strategy.

Use of a glycoprotein G-based type-specific assay to detect antibodies to herpes simplex virus type 2 among persons attending sexually transmitted disease clinics.

BACKGROUND: Most genital herpes simplex virus type 2 (HSV-2) infections are unrecognized, thus, strategies to reduce the sexual transmission of HSV-2 are partly dependent on serologic screening. GOAL: To define performance characteristics of the Gull/ Meridian glycoprotein G-based HSV-2 enzyme-linked immunosorbent assay among sexually transmitted disease clinic attendees and correlates of test acceptance. STUDY DESIGN: The cross-sectional study was conducted during two periods. Serologic testing was offered at a US $15 charge during the first period and at no charge during the second period. Sera were tested by a type-specific glycoprotein G enzyme-linked immunosorbent assay and Western blot analysis, with the latter test used as the reference standard. RESULTS: Acceptance of HSV-2 testing was associated with free testing (odds ratio, 7.5; 95% CI, 6.0-9.9), older age, and white race. Sensitivity of the HSV-2 assay was 80.5% and specificity was 98.5%. The HSV-2 positive and negative predictive values were 95.8% (95% CI, 91.6-98.0%) and 92.2% (95 % CI, 89.6 -94.2%), respectively. Antibodies to HSV-2 were detected in 25.9% of 606 persons with no history of genital herpes. CONCLUSION: Acceptance of HSV-2 serologic testing was cost sensitive. In this high-prevalence population, the positive predictive value of the enzyme-linked immunosorbent assay was sufficient to warrant its use without a confirmatory test. This assay could be useful in the screening of sexually active adults to detect unrecognized HSV-2 infection.

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.

Identification of the conjugative mef gene in clinical Acinetobacter junii and Neisseria gonorrhoeae isolates.

The mef gene, originally described for gram-positive organisms and coding for an efflux pump, has been identified in clinical isolates of Acinetobacter junii and Neisseria gonorrhoeae. These strains could transfer the mef gene at frequencies ranging from 10(-6) to 10(-9) into one or more of the following recipients: gram-negative Moraxella catarrhalis, Neisseria perflava/sicca and Neisseria mucosa and gram-positive Enterococcus faecalis. Three Streptococcus pneumoniae strains could transfer the mef gene into Eikenella corrodens, Haemophilus influenzae, Kingella denitrificans, M. catarrhalis, Neisseria meningitidis, N. perflava/sicca, and N. mucosa at similar frequencies. The mef gene can thus be transferred to and expressed in a variety of gram-negative recipients.

Gonorrhea among men who have sex with men: outbreak caused by a single genotype of erythromycin-resistant Neisseria gonorrhoeae with a single-base pair deletion in the mtrR promoter region.

During 1995-1997, an outbreak of 66 cases of gonorrhea caused by an erythromycin-resistant (Ery(r); MIC >/=1.0 microgram/mL) prototrophic (proto) auxotype IB-1 serovar of Neisseria gonorrhoeae occurred in King County, Washington; 65 cases involved men who have sex with men (MSM), which accounted for approximately 37% of infections among MSM during this period. Isolates from 19 of these 65 cases of infection were analyzed by DNA sequencing of the polymerase chain reaction-amplified promoter region of the mtrR gene and by pulsed-field gel electrophoresis (PFGE) analysis of genomic DNA after NheI and SpeI digestion. Eighteen of the 19 isolates had a 1-bp A/T deletion in a 13-bp inverted repeat of the mtrR promoter region and shared a single PFGE type. Among MSM who provided data about sexual behavior, 37 (64%) of 58 MSM infected by the proto/IB-1 Ery(r) strain reported having >2 sex partners during the past 60 days, compared with 32 (30%) of 106 MSM infected by other strains (P<.001). This clonal outbreak of gonorrhea illustrates the ongoing need for behavioral preventive interventions among MSM.

To notify or not to notify: STD patients' perspectives of partner notification in Seattle.

BACKGROUND AND OBJECTIVES: To obtain patients' perspectives on why only some partners are notified in partner-notification programs, the cornerstone of sexually transmitted disease (STD) control, although low proportions of partners are located and evaluated. GOALS: To describe patterns of partner notification reported by persons with STD infection. STUDY DESIGN: In-depth interviews conducted in Seattle with 60 heterosexual men and women with gonorrhea, chlamydial infection, or nongonoccocal urethritis, and 19 men with gonorrhea reporting sex with men (MSM) were tape recorded, transcribed verbatim, and content analyzed. RESULTS: The typical notification pattern was to notify a main partner but not others. Least likely to be notified were partners perceived as transmitters, contacts preceding the onset of symptoms, the oral sex and anonymous contacts of MSM, one-time partners of men, and incarcerated and former partners of women. Fears among young heterosexual participants included gossip and violence (women). Fears among MSM included rejection. CONCLUSIONS: Partner-notification programs should develop innovative approaches for partners perceived as transmitters, oral-sex only contacts of MSM, and contacts preceding symptom onset.

Comparative epidemiology of heterosexual gonococcal and chlamydial networks: implications for transmission patterns.

OBJECTIVE: Networks of sex-partner interaction affect differential risk of acquiring sexually transmitted infections. The authors evaluated sociodemographic and behavioral factors that correlated with membership in networks of gonococcal and chlamydial transmission. METHODS: Face-to-face interviews were conducted with 127 patients with gonorrhea and 184 patients with chlamydia (index cases) and their named sex partners, as well as the partners of infected partners. Detailed information was obtained regarding demographic, behavioral, and sexual-history characteristics of all respondents. RESULTS: Gonococcal-network members differed significantly from chlamydial-network members in a number of demographic variables, including race or ethnicity, education, and unemployment status. Gonococcal-network members were more likely to report past history of crack-cocaine use, sexual assault, and having been in jail. Gonococcal-network members also reported having more sex partners during the past 1 year and 3 months than did chlamydial-network members. Gonococcal and chlamydial mixing matrices demonstrated assortativeness for sex partner selection by race or ethnicity but not by sexual activity level, and no systematic differences between networks were noted. Gonococcal networks were larger than chlamydial networks. CONCLUSIONS: Network analyses of gonococcal and chlamydial infections demonstrated significant differences in sociodemographic and behavioral variables. Further research is required to delineate specific predictors of network membership among persons at risk for sexually transmitted infections.

Unique gonococcal phenotype associated with asymptomatic infection in men and with erroneous diagnosis of nongonococcal urethritis.

The percentage of gonococcal isolates in King County, Washington, requiring citrulline and uracil (CU auxotype) increased from 1.6% in 1986 to 16.5% in 1997. Among men, urethral infection with the CU auxotype (n=93), in comparison with infection by other auxotypes (n=1211), was associated with coexisting chlamydial infection, younger age, heterosexual contact, and fewer new recent partners (P<. 05). Among heterosexual men, urethral infection with the CU auxotype, compared with infection with other auxotypes, less often produced symptoms of urethral discharge (75% vs. 92%) or dysuria (47% vs. 74%) or signs of moderate or profuse urethral discharge (57% vs. 89%, P<.05 for each comparison), produced symptoms of longer duration (7. 0 vs. 4.5 days, P<.01), less often resulted in urethral smears showing gram-negative intracellular diplococci (67% vs. 95%, P<.01), and thus more often was erroneously diagnosed as nongonococcal urethritis. Several mechanisms could explain reduced inflammatory response to the CU auxotype and its recent spread.

Partner notification for chlamydial infections among private sector clinicians in Seattle-King County: a clinician and patient survey.

BACKGROUND & OBJECTIVES: To describe partner notification practices for chlamydial infections among private sector clinicians. STUDY DESIGN: Telephone interviews of clinicians and patients identified through public health case reports in Seattle-King County, August-October 1998. RESULTS: Clinicians reported advising 135 of 150 (90%) patients to notify their sex partners, but knew that all partners of only 26 (17%) patients received treatment. While 71 (57%) clinicians acknowledged ever providing medicine-to a patient to give to a partner, only 6 (4%) so treated a patient about whom they were interviewed. Most (87%) clinicians believed the health department should routinely contact all patients about partner notification. Almost all patients (72/76-95%) reported that their provider had advised them to notify their partners and 59 (78%) stated they did so. Most patients (11/17-65%) who did not notify all of their partners would have been willing to allow their clinician or the heath department to do it for them. CONCLUSION: Private sector clinicians and their patients are generally unaware of chlamydial partner notification outcomes but are receptive to expanded partner notification services.

Alterations within the quinolone resistance-determining regions of GyrA and ParC of Neisseria gonorrhoeae isolated in the Far East and the United States.

The genetic mutations within the quinolone resistance-determining regions (QRDRs) of gyrA and parC of 234 Neisseria gonorrhoeae strains isolated in the Far East and the United States, which exhibited either clinically significant ciprofloxacin resistance (CipR) or intermediate ciprofloxacin resistance (CipI) were characterized. A number of GyrA/ParC amino acid alteration patterns were identified, the most prevalent alteration pattern among CipR isolates being GyrA-91,95/ParC-Asp-86- > Asn (91,95/Asp-86- > Asn). Isolates containing 91,95/Asp-86- > Asn belonged to a number of A/S classes, penicillin/tetracycline resistance phenotypes, and plasmid profiles. These results strongly suggest that the continuing emergence of ciprofloxacin-resistant gonococci is not due to the spread of a single or a few strains but to numerous factors such as 'spread of existing strains, importation of new strains and, possibly, de novo development of ciprofloxacin resistance in previously susceptible strains.

Elimination and reintroduction of primary and secondary syphilis.

OBJECTIVES: This study was conducted to define factors associated with the epidemic spread, elimination, and reintroduction of primary and secondary syphilis in King County, Washington, from 1987 through 1998. METHODS: Reports of primary and secondary syphilis in King County from 1987 through 1998 were reviewed retrospectively. RESULTS: During the epidemic spread of syphilis, only 15.8% of cases were imported. A total of 24.0% of patients reported cocaine use, and 18.3% of female patients reported having commercial sex. During the elimination of syphilis, significantly higher percentages of cases were imported and lower percentages of patients reported cocaine use or female commercial sex. During the reintroduction of syphilis in 1997-1998, 68% of patients were men who reported sex with men; of this 68%, 66% were sero-positive for HIV. Most men reporting sex with men were 30 years or older and recruited many anonymous partners. CONCLUSIONS: As syphilis wanes, local control must focus on outbreaks following its reintroduction. Resurgence of syphilis among men reporting sex with men recapitulates the epidemiology of syphilis before the historical advent of AIDS, warranting immediate attention to this problem.

Erythromycin-resistant Neisseria gonorrhoeae and oral commensal Neisseria spp. carry known rRNA methylase genes.

Two Neisseria gonorrhoeae isolates from Seattle and two isolates from Uruguay were resistant to erythromycin (MIC, 4 to 16 microg/ml) and had reduced susceptibility to azithromycin (MIC, 1 to 4 microg/ml) due to the presence of the self-mobile rRNA methylase gene(s) ermF or ermB and ermF. The two Seattle isolates and one isolate from Uruguay were multiresistant, carrying either the 25.2-MDa tetM-containing plasmid (Seattle) or a beta-lactamase plasmid (Uruguay). Sixteen commensal Neisseria isolates (10 Neisseria perflava-N. sicca, 2 N. flava, and 4 N. mucosa) for which erythromycin MICs were 4 to 16 microg/ml were shown to carry one or more known rRNA methylase genes, including ermB, ermC, and/or ermF. Many of these isolates also were multiresistant and carried the tetM gene. This is the first time that a complete transposon or a complete conjugative transposon carrying an antibiotic resistance gene has been described for the genus Neisseria.