The Relationship Between Insertive Oral and Anal Sex and Select Measures of the Composition of the Urethral Microbiota Among Men Who Have Sex With Men.

BACKGROUND: Sexual behavior may influence the composition of the male urethral microbiota, but this hypothesis has not been tested in longitudinal studies of men who have sex with men (MSM). METHODS: From December 2014 to July 2018, we enrolled MSM with nongonococcal urethritis (NGU) attending a sexual health clinic. Men attended 5 in-clinic visits at 3-week intervals, collected weekly urine specimens at home, and reported daily antibiotics and sexual activity on weekly diaries. We applied broad-range 16S rRNA gene sequencing to urine. We used generalized estimating equations to estimate the association between urethral sexual exposures in the prior 7 days (insertive oral sex [IOS] only, condomless insertive anal intercourse [CIAI] only, IOS with CIAI [IOS + CIAI], or none) and Shannon index, number of species (observed, oral indicator, and rectal indicator), and specific taxa, adjusting for recent antibiotics, age, race/ethnicity, HIV, and preexposure prophylaxis. RESULTS: Ninety-six of 108 MSM with NGU attended ≥1 follow-up visit. They contributed 1140 person-weeks of behavioral data and 1006 urine specimens. Compared with those with no urethral sexual exposures, those with IOS only had higher Shannon index ( P = 0.03 ) but similar number of species and presence of specific taxa considered, adjusting for confounders; the exception was an association with Haemophilus parainfluenzae . CIAI only was not associated with measured aspects of the urethral microbiota. IOS + CIAI was only associated with presence of H. parainfluenzae and Haemophilus . CONCLUSIONS: Among MSM after NGU, IOS and CIAI did not seem to have a substantial influence on measured aspects of the composition of the urethral microbiota.

Should We Be Testing for Mycoplasma genitalium on Initial Presentation? Trends in Persistent/Recurrent Urethritis Among Men Presenting for Care in STD Clinics, 2015-2019, STD Surveillance Network.

BACKGROUND: Mycoplasma genitalium is a major contributor to persistent/recurrent urethritis cases. However, there are limited published studies on recent trends of persistent/recurrent urethritis. METHODS: A retrospective analysis was conducted of men presenting with symptomatic urethritis in 16 sexually transmitted disease (STD) clinics from 2015 to 2019. Poisson regression was used to assess trends in the annual proportions of urethritis episodes with follow-up (FU) characterized with persistent/recurrent urethritis symptoms. Results were also stratified by results of chlamydia (CT) and gonorrhea (NG) testing and treatment prescribed. RESULTS: There were 99,897 urethritis episodes, from 67,546 unique men. The proportion of episodes with persistent/recurrent symptomatic FU visits increased 50.8% over a 4-year period (annual percentage change [APC], 11.3%; 95% confidence interval [CI], 6.5-16.3). Similar trends were observed in nonchlamydial nongonococcal urethritis episodes (APC, 12.7%; 95% CI, 6.8-18.9) but increases among those positive for NG (APC, 12.1%; 95% CI, -2.3 to -28.5) or for CT (APC, 7.3%; 95% CI, -6.7 to 23.5) were not statistically significant. Among episodes who received azithromycin as first-line treatment, increases in the proportion of persistent/recurrent FU visits were observed (APC, 12.6%; 95% CI, 8.6-16.7). For episodes where first-line treatment was doxycycline, no significant increases were detected (APC, 4.3%; 95% CI, -0.3 to 9.2). CONCLUSIONS: We found an increase in the proportion of urethritis episodes with persistent or recurrent symptoms over time. Given these observed trends in episodes negative for NG or CT, an etiology not detectable by routine diagnostics was a likely factor in increased persistence, suggesting patients with urethritis may benefit from diagnostic testing for M. genitalium during an initial symptomatic presentation.

Isolation and Genomic Characterization of Schaalia turicensis from a Patient with Gonococcal Urethritis, Thailand.

Schaalia turicensis is facultative anaerobic Gram-positive bacillus that commonly inhabits the oropharynx, gastrointestinal, and genitourinary tract of healthy individuals. This organism has been co-isolated with Neisseria gonorrhoeae from 15-year-old Thai male patient with gonococcal urethritis in Bangkok, Thailand. In this study, we characterized the class 1 integron in S. turicensis isolate using whole-genome sequencing and bioinformatics analysis. Sequencing analysis confirmed the presence of an imperfect class 1 integron located on chromosome and a novel 24.5-kb-long composite transposon, named Tn7083. The transposon Tn7083 carried genes encoding chloramphenicol resistance (cmx), sulfonamide resistance (sul1), and aminoglycoside resistance [aph(6)-Id (strB), aph(3'')-Ib (strA), aph(3')-Ia].

Characterization of Virulence-Associated Traits in Mycoplasma penetrans Strains Acting as Likely Etiological Agents of Idiopathic Nongonococcal Urethritis.

Mycoplasma penetrans is an emerging pathogen with a reduced genome. This bacterium has only previously been cultured from individuals with chronic immunodeficiencies. Here we report the characteristics of 4 M. penetrans isolates from the urine of immunocompetent males with nongonococcal urethritis, in comparison with strain HF-2 from an immunocompromised patient. Several features exhibited distinct differences between these isolates and HF-2. Unlike HF-2, all 4 were resistant to azithromycin. They exhibited greater sialic acid-dependent binding to erythrocytes, gliding motility speed, and H2O2 production than HF-2. All new isolates produced thinner capsules than HF-2. Invasiveness varied, with some isolates being more invasive than HF-2 and some less invasive. Cytotoxicity to HeLa cells was similar to HF-2, and all strains could clear extracellular traps produced by innate immune cells. We conclude that subtle differences among M. penetrans strains may be critical for this organism to establish an infection in an otherwise healthy individual.

Detection of Novel US Neisseria meningitidis Urethritis Clade Subtypes in Japan.

Neisseria meningitidis causes invasive meningococcal diseases and has also been identified as a causative agent of sexually transmitted infections, including urethritis. Unencapsulated sequence type 11 meningococci containing the gonococcal aniA-norB locus and belonging to the United States N. meningitidis urethritis clade (US_NmUC) are causative agents of urethral infections in the United States, predominantly among men who have sex with men. We identified 2 subtypes of unencapsulated sequence type 11 meningococci in Japan that were phylogenetically close to US_NmUC, designated as the Japan N. meningitidis urethritis clade (J_NmUC). The subtypes were characterized by PCR, serologic testing, and whole-genome sequencing. Our study suggests that an ancestor of US_NmUC and J_NmUS urethritis-associated meningococci is disseminated worldwide. Global monitoring of urethritis-associated N. meningitidis isolates should be performed to further characterize microbiologic and epidemiologic characteristics of urethritis clade meningococci.

Latest Advances in Laboratory Detection of Mycoplasma genitalium.

Mycoplasma genitalium is an important sexually transmitted pathogen affecting both men and women. Its extremely slow growth in vitro and very demanding culture requirements necessitate the use of molecular-based diagnostic tests for its detection in clinical specimens. The recent availability of U.S. Food and Drug Administration (FDA)-cleared commercial molecular-based assays has enabled diagnostic testing to become more widely available in the United States and no longer limited to specialized reference laboratories. Advances in the knowledge of the epidemiology and clinical significance of M. genitalium as a human pathogen made possible by the availability of molecular-based testing have led to updated guidelines for diagnostic testing and treatment that have been published in various countries. This review summarizes the importance of M. genitalium as an agent of human disease, explains the necessity of obtaining a microbiological diagnosis, describes currently available diagnostic methods, and discusses how the emergence of antimicrobial resistance has complicated treatment alternatives and influenced the development of diagnostic tests for resistance detection, with an emphasis on developments over the past few years.

Bacterial vaginosis-associated bacteria in cisgender men who have sex with women: prevalence, association with non-gonococcal urethritis and natural history.

OBJECTIVES: Bacterial vaginosis-associated bacterium 2 (BVAB2), Mageeibacillus indolicus and Sneathia spp are highly predictive of bacterial vaginosis (BV) in cisgender women. They have been associated with non-gonococcal urethritis (NGU) in cisgender men in some but not all populations. We evaluated this association in a cross-sectional study of cisgender men who have sex with women only (MSW). METHODS: MSW without gonorrhoea attending a sexual health clinic (SHC) from 2014 to 2018 completed a computer-assisted self-interview, clinical interview and examination. NGU was defined as ≥5 polymorphonuclear leucocytes/high-power field in urethral exudates plus either urethral symptoms or visible discharge. Urine was tested for Chlamydia trachomatis and Mycoplasma genitalium using Aptima (Hologic) and for BVAB2, M. indolicus, Sneathia spp, Trichomonas vaginalis, Ureaplasma urealyticum, Haemophilus influenzae, herpes simplex virus and adenovirus using quantitative PCR. RESULTS: Of 317 MSW age 17-71, 67 (21.1%) had Sneathia spp, 36 (11.4%) had BVAB2, and 17 (5.4%) had M. indolicus at enrolment. Having ≥3 partners in the past 2 months was the only characteristic that was more common among MSW with than those without these bacteria (BVAB2: 47% vs 23%, M. indolicus: 53% vs 24%, Sneathia spp: 42% vs 22%; p≤0.03 for all). One-hundred seventeen men (37%) were diagnosed with NGU at enrolment. There was no significant association of BVAB2, M. indolicus or Sneathia spp with NGU (adjusted OR=0.59, 95% CI 0.14 to 2.43; aOR=3.40, 95% CI 0.68 to 17.06; aOR=0.46, 95% CI 0.16 to 1.27). Of 109 MSW with monthly samples, 34 (31.2%) had one of the bacteria at one or more follow-up visits, 22 of which were co-colonised with >1. Median persistence over 6 months did not differ significantly (BVAB2=30.5 days, IQR=28-87; M. indolicus=87 days, IQR=60-126; Sneathia spp=70 days, IQR=30-135; p≥0.20 for each comparison). CONCLUSIONS: Neither BVAB2, M. indolicus nor Sneathia spp were associated with increased risk of prevalent NGU in MSW attending an SHC.

Novel use of oral chloramphenicol for treatment-resistant Mycoplasma genitalium.

We describe the novel use of oral chloramphenicol for treatment-resistant Mycoplasma genitalium (M. genitalium) infection in a 20-year-old heterosexual cisgender male presenting with recurrent symptomatic non-gonococcal urethritis. M. genitalium urethritis is an increasingly common clinical conundrum in sexual health clinics and in cases of second-line treatment failure (such as moxifloxacin), UK and international guidelines struggle to make recommendations for third-line treatments. As shown in our case, the evidence base for third-line treatments is lacking, with poor success rates, and may be poorly tolerated. Here we demonstrate the novel use of a well-tolerated oral antimicrobial, chloramphenicol, resulting in rapid microbiological and clinical cure in treatment-resistant M. genitalium urethritis.

A case of chronic bacterial prostatitis due to Mycoplasma genitalium.

Mycoplasma genitalium (MG) is a common cause of non-gonococcal urethritis, but a role in acute or chronic prostatitis has not been described. We describe the case of a 42-year-old man with recurrent urinary tract infections since 2018 who developed chronic prostatitis despite several and prolonged antibiotic courses. Multiparametric prostatic magnetic resonance showed peripheral inflammatory alterations. A 4-glass Meares-Stamey test detected MG in the third voided bladder (VB3) sample. Moxifloxacin 400 mg daily for 28 days resulted in sustained clinical and microbiological cure.

Chlamydia trachomatis Coinfection Does Not Influence Mycoplasma genitalium Bacterial Load in Urogenital Samples.

BACKGROUND: Mycoplasma genitalium (MG) is associated with urethritis in men and weakly associated with pelvic inflammatory disease in women. Mycoplasma genitalium coinfections with Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) are commonly reported; however, little is known about their interaction. One study suggested that MG/NG coinfections might increase the bacterial load of NG, which has been shown to have a higher transmission potential. As even less is known about the impact of a simultaneous MG/CT infection, we assessed whether patients with urogenital MG/CT coinfections have a higher bacterial load than patients with a single infection. METHODS: There were 1673 urogenital samples from patients from a population-based chlamydia study, and our sexually transmitted infection clinic tested for both CT and MG. When positive, the load was quantified. Nonparametric tests compared the CT and MG load, and linear regression analyses tested the association of the CT and MG load within a patient. RESULTS: In 60 MG-positive patients, MG load ranged from 1.7 to 6.0 log10 copies/ml, similar to the CT load distribution. Only 6 patients were MG-positive and CT-negative, but the MG load distribution was similar to that of CT-positive patients (n.s.). The MG and CT load was unrelated in coinfected persons (n.s.). CONCLUSIONS: We found no correlation between the CT and MG load in urogenital samples, and the MG load distribution was similar in CT-positive and CT-negative patients. These results could have implications for the transmission risk of these infections.

The third nationwide surveillance of antimicrobial susceptibility against Neisseria gonorrhoeae from male urethritis in Japan, 2016-2017.

Neisseria gonorrhoeae is one of the important pathogens of sexually transmitted infections. N. gonorrhoeae is rapidly becoming antimicrobial resistant, and there are few drugs that are effective in the initial treatment of gonorrhea. To understand the trends of antimicrobial susceptibility of N. gonorrhoeae, the Surveillance Committee of the Japanese Society of Infectious Diseases, the Japanese Society for Chemotherapy, and the Japanese Society of Clinical Microbiology conducted the third nationwide antimicrobial susceptibility surveillance of N. gonorrhoeae isolated from male urethritis. The specimens were collected from male patients with urethritis at 30 facilities from May 2016 to July 2017. From the 159 specimens collected, 87 N. gonorrhoeae strains were isolated, and 85 were tested for susceptibility to 21 antimicrobial agents. All strains were non-susceptible to penicillin G. Seven strains (8.2%) were ß-lactamase-producing strains. The rates of susceptibility to cefixime and cefpodoxime were 96.5% and 52.9%, respectively. Three strains were non-susceptible with a minimum inhibitory concentration (MIC) of 0.5 mg/L for cefixime. None of the strains were resistant to ceftriaxone or spectinomycin. The susceptibility rate for ciprofloxacin was 23.5% (20 strains), and no strains showed intermediate susceptibility. The susceptibility rate against azithromycin was 81.2%, with one strain isolated with a MIC of 8 mg/L against azithromycin. The results of this surveillance indicate that ceftriaxone and spectinomycin, which are currently recommended for gonococcal infections in Japan, appear to be effective. It will be necessary to further expand the scale of the next surveillance to understand the current status of drug-resistant N. gonorrhoeae in Japan.

Meningococcal Urethritis: Old and New.

Neisseria meningitidis is a common commensal bacterium found in the respiratory tract, but it can also cause severe, invasive disease. Vaccines have been employed which have been successful in helping to prevent invasive disease caused by encapsulated N. meningitidis from the A, C, W, Y, and B serogroups. Currently, nonencapsulated N. meningitidis groups are more common commensals in the population than in the prevaccine era. One emerging nonencapsulated group of bacteria is the U.S. N. meningitidis urethritis clade (US_NmUC), which can cause meningococcal urethritis in men. US_NmUC has unique genotypic and phenotypic features that may increase its fitness in the male urethra. It is diagnostically challenging to identify and distinguish meningococcal urethritis from Neisseria gonorrhoeae, as the clinical presentation and microbiological findings are overlapping. In this review, the history of meningococcal urethritis, emergence of US_NmUC, laboratory diagnosis, and clinical treatment are all explored.

Culture obtained from urethral swab of asymptomatic men who screen positive for Neisseria gonorrhoeae by urine nucleic acid amplification testing.

BACKGROUND: In a previous study of men attending Melbourne Sexual Health Centre who had Neisseria gonorrhoeae detected by urine Aptima Combo 2 (AC2) testing, 11% were asymptomatic. This study aimed to determine whether N. gonorrhoeae can be cultured from asymptomatic men screening positive for N. gonorrhoeae by nucleic acid amplification testing (NAAT) of urine. METHODS: Between 1 July 2017 and 31 March 2019, all men attending Melbourne Sexual Health Centre were tested for N. gonorrhoeae by AC2 testing of urine whether urethral symptoms were reported or not. NAAT-positive men were recalled and a urethral swab performed for gonococcal culture using modified Thayer-Martin media with determination of minimum inhibitory concentrations (MICs) by agar dilution. RESULTS: There were 1001 cases (860 individuals) positive for N. gonorrhoeae by urine AC2: 892 (89%) reported urethral symptoms; 109 (11%) did not. Twenty-five asymptomatic cases were excluded because of antibiotic use at or following screening. Of the remaining 84 asymptomatic men, 41 (49%) had a urethral swab performed a median of 5 days after screening. Twenty-one men had urethral discharge at the return visit, 11 of whom reported the discharge at the return visit. Of the 41 men who were swabbed, 31 (76%; 95% CI 60% to 88%) were culture positive for N. gonorrhoeae. Among the 21 men who subsequently developed discharge, 19 (90%; 95% CI 70% to 99%) were culture positive. Among the 20 men who remained asymptomatic, 12 (60%; 95% CI 36% to 81%) were culture positive. MIC profiles were obtained from all isolates. CONCLUSIONS: Gonorrhoea was isolated in most but not all asymptomatic men screening positive for N. gonorrhoeae by urine NAAT. Clinicians should consider performing urethral culture in such men to ensure optimal surveillance for antimicrobial resistance. Isolation of N. gonorrhoeae by culture in men without discharge indicates these are true infections with viable organisms.

Evaluation of Clinical, Gram Stain, and Microbiological Cure Outcomes in Men Receiving Azithromycin for Acute Nongonococcal Urethritis: Discordant Cures Are Associated With Mycoplasma genitalium Infection.

BACKGROUND: In men with nongonococcal urethritis (NGU), clinicians and patients rely on clinical cure to guide the need for additional testing/treatment and when to resume sex, respectively; however, discordant clinical and microbiological cure outcomes do occur. How accurately clinical cure reflects microbiological cure in specific sexually transmitted infections (STIs) is unclear. METHODS: Men with NGU were tested for Neisseria gonorrhoeae, Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Trichomonas vaginalis, urethrotropic Neisseria meningitidis ST-11 clade strains, and Ureaplasma urealyticum (UU). Men received azithromycin 1 g and returned for a 1-month test-of-cure visit. In MG infections, we evaluated for the presence of macrolide resistance-mediating mutations (MRMs) and investigated alternate hypotheses for microbiological treatment failure using in situ shotgun metagenomic sequencing, phylogenetic analysis, multilocus sequence typing analyses, and quantitative PCR. RESULTS: Of 280 men with NGU, 121 were included in this analysis. In the monoinfection group, 52 had CT, 16 had MG, 7 had UU, 10 had mixed infection, and 36 men had idiopathic NGU. Clinical cure rates were 85% for CT, 100% for UU, 50% for MG, and 67% for idiopathic NGU. Clinical cure accurately predicted microbiological cure for all STIs, except MG. Discordant results were significantly associated with MG-NGU and predominantly reflected microbiological failure in men with clinical cure. Mycoplasma genitalium MRMs, but not MG load or strain, were strongly associated with microbiological failure. CONCLUSIONS: In azithromycin-treated NGU, clinical cure predicts microbiological cure for all STIs, except MG. Nongonococcal urethritis management should include MG testing and confirmation of microbiological cure in azithromycin-treated MG-NGU when MRM testing is unavailable.

Gonococcal tysonitis, a rare local complication of gonorrhea: a clinical study of 15 cases.

To investigate the incidence, clinical manifestations, and treatments of gonococcal tysonitis in men. We enrolled men with gonococcal tysonitis and men with gonococcal urethritis from January 2000 to December 2020. Demographic data, interval from non-marital sexual contact to the onset of symptoms of gonococcal tysonitis, occurrence sites, and manifestations were recorded for all patients. Ceftriaxone (1 g) was injected intramuscularly once daily for 5 days in patients with lesions comprising abscesses or nodules. A single dose of ceftriaxone (1 g) was injected intramuscularly in patients with sinus-like lesions. Incision and drainage were performed in patients with non-ruptured abscesses. Fifteen patients with gonococcal tysonitis (0.29%; 95% confidence interval: 0.15-0.44%) were observed among 5087 patients with gonococcal urethritis. The mean age was 38.64 years (range, 17-74 years). The mean gonococcal tysonitis incubation period was 6.02 ± 1.37 days (range, 2-11 days). Lesions were present in the right side of the preputial frenulum in seven patients (46.67%), in the left side of the preputial frenulum in six patients (40%), and in both sides of preputial frenulum in two patients (13.33%). The lesions manifested as abscesses in 7 patients (46.67%), nodules in six patients (40%), and sinus-like lesions in two patients (13.33%); all lesions exhibited tenderness. All 15 patients were cured after treatment. Gonococcal tysonitis is a rare local complication of gonorrhea. Gonococcal urethritis with concurrent gonococcal tysonitis was less common than gonococcal urethritis with concurrent paraurethral gonococcal infection or gonococcal urethritis with concurrent gonococcal epididymitis. Gonococcal tysonitis lesions manifest as abscesses, nodules, and sinus-like lesions. Treatment with ceftriaxone is effective for gonococcal tysonitis.

Emergence of a novel urogenital-tropic Neisseria meningitidis.

PURPOSE OF REVIEW: Neisseria meningitidis (Nm) is primarily associated with asymptomatic nasopharyngeal carriage and invasive meningococcal disease (sepsis and meningitis), but like N. gonorrhoea (Ng), Nm can colonize urogenital and rectal mucosal surfaces and cause disease. First noted in 2015, but with origins in 2011, male urethritis clusters caused by a novel Nm clade were reported in the USA (the US_NmUC). This review describes research developments that characterize this urogenital-tropic Nm. RECENT FINDINGS: The US_NmUC evolved from encapsulated Nm serogroup C strains. Loss of capsule expression, lipooligosaccharide (LOS) sialylation, genetic acquisition of gonococcal alleles (including the gonococcal anaerobic growth aniA/norB cassette), antimicrobial peptide heteroresistance and high surface expression of a unique factor-H-binding protein, can contribute to the urethra-tropic phenotype. Loss-of-function mutations in mtrC are overrepresented in clade isolates. Similar to Ng, repeat US_NmUC urethritis episodes can occur. The US_NmUC is now circulating in the UK and Southeast Asia. Genomic sequencing has defined the clade and rapid diagnostic tests are being developed for surveillance. SUMMARY: The US_NmUC emerged as a cause of urethritis due to acquisition of gonococcal genetic determinants and phenotypic traits that facilitate urogenital tract infection. The epidemiology and pathogenesis of this urogenital-tropic pathogen continues to be defined.

Urethritis: Rapid Evidence Review.

Urethritis refers to inflammation of the urethra and is classified as gonococcal (caused by Neisseria gonorrhoeae) or nongonococcal in origin (most commonly caused by Chlamydia trachomatis, Mycoplasma genitalium, or Trichomonas vaginalis). The most common signs and symptoms include dysuria, mucopurulent urethral discharge, urethral discomfort, and erythema. Diagnostic criteria include typical signs, symptoms, or history of exposure in addition to mucopurulent discharge, Gram stain of urethral secretions showing at least two white blood cells per oil immersion field, first-void urinalysis showing at least 10 white blood cells per high-power field, or a positive leukocyte esterase result with first-void urine. First-line empiric treatment consists of ceftriaxone and doxycycline; however, the antibiotic regimen may be targeted to the isolated organism. Repeat testing is not recommended less than three weeks after treatment because false-positive results are possible during this time. Patients treated for a sexually transmitted infection should have repeat screening in three months, with shared decision-making about future screening intervals. Patients treated for urethritis should abstain from sex for seven days after the start of treatment, until their partners have been adequately treated, and until their symptoms have fully resolved.

The Role of Ureaplasma spp. in the Development of Nongonococcal Urethritis and Infertility among Men.

Ureaplasma spp. are a genus of bacteria for which two human-associated species exist: Ureaplasma urealyticum and Ureaplasma parvum Their definition as a pathogen in the context of nongonococcal urethritis (NGU) and infertility among males remains highly controversial, largely due to historically high rates of isolation of these bacteria from the urethra of seemingly healthy men. This review summarizes the emerging evidence suggesting a true pathogenic role of these bacteria under specific conditions, which we term risk factors. We examine the historical, clinical, and experimental studies which support a causal role for Ureaplasma spp. in the development of NGU as well as some of the proposed mechanisms behind the association of Ureaplasma spp. and the development of infertility. Finally, we discuss the potential for developing a case-by-case risk-based approach toward the management of men who present with seemingly idiopathic NGU but who are positive for Ureaplasma spp.

Neisseria meningitidis Urethritis Outbreak Isolates Express a Novel Factor H Binding Protein Variant That Is a Potential Target of Group B-Directed Meningococcal (MenB) Vaccines.

Factor H binding protein (FHbp) is an important Neisseria meningitidis virulence factor that binds a negative regulator of the alternative complement pathway, human factor H (FH). Binding of FH increases meningococcal resistance to complement-mediated killing. FHbp also is reported to prevent interaction of the antimicrobial peptide (AMP) LL-37 with the meningococcal surface and meningococcal killing. FHbp is a target of two licensed group B-directed meningococcal (MenB) vaccines. We found a new FHbp variant, peptide allele identification no. 896 (ID 896), was highly expressed by an emerging meningococcal pathotype, the nonencapsulated urethritis clade (US_NmUC). This clade has been responsible for outbreaks of urethritis in multiple U.S. cities since 2015, other mucosal infections, and cases of invasive meningococcal disease. FHbp ID 896 is a member of the variant group 1 (subfamily B), bound protective anti-FHbp monoclonal antibodies, bound high levels of human FH, and enhanced the resistance of the clade to complement-mediated killing in low levels of human complement likely present at human mucosal surfaces. Interestingly, expression of FHbp ID 896 resulted in augmented killing of the clade by LL-37. FHbp ID 896 of the clade was recognized by antibodies elicited by FHbp in MenB vaccines.

Heteroresistance to the model antimicrobial peptide polymyxin B in the emerging Neisseria meningitidis lineage 11.2 urethritis clade: mutations in the pilMNOPQ operon.

Clusters of Neisseria meningitidis (Nm) urethritis among primarily heterosexual males in multiple US cities have been attributed to a unique non-encapsulated meningococcal clade (the US Nm urethritis clade, US_NmUC) within the hypervirulent clonal complex 11. Resistance to antimicrobial peptides (AMPs) is a key feature of urogenital pathogenesis of the closely related species, Neisseria gonorrhoeae. The US_NmUC isolates were found to be highly resistant to the model AMP, polymyxin B (PmB, MICs 64-256 µg ml-1 ). The isolates also demonstrated stable subpopulations of heteroresistant colonies that showed near total resistant to PmB (MICs 384-1024 µg ml-1 ) and colistin (MIC 256 µg ml-1 ) as well as enhanced LL-37 resistance. This is the first observation of heteroresistance in N. meningitidis. Consistent with previous findings, overall PmB resistance in US_NmUC isolates was due to active Mtr efflux and LptA-mediated lipid A modification. However, whole genome sequencing, variant analyses and directed mutagenesis revealed that the heteroresistance phenotypes and very high-level AMP resistance were the result of point mutations and IS1655 element movement in the pilMNOPQ operon, encoding the type IV pilin biogenesis apparatus. Cross-resistance to other classes of antibiotics was also observed in the heteroresistant colonies. High-level resistance to AMPs may contribute to the pathogenesis of US_NmUC.