Orogenital Transmission of Neisseria meningitidis Causing Acute Urethritis in Men Who Have Sex with Men

[Urethritis-spectrum of pathogens, diagnostics and treatment]

A broad spectrum of bacteria, fungi, protozoa and viruses can cause urethritis. In particular, N. gonorrhoeae, C. trachomatis, M. genitalium and T. vaginalis are the focus of diagnostic considerations as classic pathogens associated with sexually transmitted infections (STI). A step-by-step procedure is needed to make a definitive diagnosis. Microscopy with a staining preparation provides an initial differentiation between gonoccocal and non-gonococcal urethritis in symptomatic men as a point-of-care (POC) test. Nucleic acid amplification technology (NAAT) is used for specific and sensitive pathogen detection and, as a multiplex diagnostic test, offers the possibility of detecting several organisms from the same sample. In addition, compared to culture, no vital organisms are required, which allows the collection and use of more diverse and less invasive biological samples (e.g. first stream urine in men or vaginal swabs). Susceptibility testing by culture remains essential for N. gonorrhoeae as resistance is emerging. The treatment of urethritis depends on the suspected or proven pathogen according to the current guidelines. Treatment failure can be caused by many factors (coinfection, lack of therapy adherence, reinfection or resistance of the pathogen) and requires a repeated diagnostic and therapeutic procedure and differentiated approach.

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.

Global epidemiology and changing clinical presentations of invasive meningococcal disease: a narrative review

Neisseria meningitidis (the meningococcus) causes significant morbidity and mortality worldwide through an epidemic or sporadic invasive infections. The epidemiology of N. meningitidis is changing and unpredictable. Certain emerging meningococcal genotypes seem to be associated with increasing unusual clinical presentations. Indeed, early symptoms may vary and are frequently non-specific. However, atypical clinical forms including abdominal presentations, septic arthritis, and bacteremic pneumonia may lead to misdiagnosis and some are usually associated with higher case fatality rates due to delayed optimal management. Improving awareness of clinicians and public health specialists about these unusual but potentially severe presentations should help establish prompt diagnoses and provide appropriate management of cases. In this review, we described unusual panels of clinical presentations of invasive meningococcal disease linked to the recent changes in meningococcal epidemiology.

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.

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11–14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

Clinical Conundrum: Neisseria meningitidis Septic Abortion

Septic shock after abortion is an important cause of global maternal mortality but is rarely encountered in developed countries. We describe a case of septic abortion with a novel associated pathogen: Neisseria meningitidis. A 30-year-old multiparous woman presented in septic shock after an incomplete spontaneous abortion. She received empiric antibiotics and vasopressors, underwent an urgent dilatation and curettage, and was admitted to the intensive care unit. Her blood cultures and endometrial tissue were positive for N. meningitidis. Antibiotics were adjusted based on culture, and the patient recovered. Septic shock requires prompt identification, antibiotic administration, and source control. Here, we identify an uncommon pathogen associated with septic abortion and highlight the importance of broad empiric and subsequent culture-guided antibiotic choice to ensure coverage.

Carriage of Neisseria meningitidis in Men Who Have Sex With Men Presenting to Public Sexual Health Clinics, New York City

BACKGROUND

We conducted a Neisseria meningitidis (Nm) carriage study among men who have sex with men (MSM) to explore possible sexual transmission.

METHODS

We paired information on patient characteristics with oropharyngeal, rectal, and urethral Nm culture results to assess associations with Nm carriage among 706 MSM at New York City sexual health clinics. The Nm isolates were characterized by whole genome sequencing.

RESULTS

Twenty-three percent (163 of 706) of MSM were Nm carriers. Oropharyngeal carriage was 22.6% (159 of 703), rectal 0.9% (6 of 695), and urethral 0.4% (3 of 696). Oropharyngeal carriage was associated with the following recent (past 30 days) exposures: 3 or more men kissed (adjusted relative risk [aRR], 1.38; 95% confidence interval [CI], 1.03-1.86), performing oral sex (aRR, 1.81; 95% CI, 1.04-3.18), and antibiotic use (aRR, 0.33; 95% CI, 0.19-0.57). Sixteen clonal complexes were identified; 27% belonged to invasive lineages.

CONCLUSIONS

Our findings suggest that oral sex and the number of recent kissing partners contribute to Nm carriage in MSM.

Raisonnement clinique : Avortement septique à Neisseria meningitidis

Le choc septique post-avortement est une cause mondiale importante de mortalité maternelle, mais on l'observe rarement dans les pays développés. Nous décrivons ici un cas d'avortement septique associé à un nouvel agent pathogène : Neisseria meningitidis. Une femme multipare de 30 ans s'est trouvée en choc septique après un avortement spontané incomplet. Elle a reçu un traitement empirique par antibiotiques et vasopresseurs, a subi une dilatation-aspiration d'urgence et a été admise à l'unité de soins intensifs. L'hémoculture et l'analyse de tissus endométriaux se sont révélées positives à la bactérie N. meningitidis. L'antibiothérapie a été ajustée en fonction de la culture et la patiente s'est rétablie. Il importe de reconnaître le choc septique, d'administrer l'antibiothérapie et de neutraliser la source d'infection dans les plus brefs délais. Ici, nous décrivons un cas d'avortement septique associé à un agent pathogène inhabituel. Nous soulignons aussi l'importance d'utiliser une antibiothérapie empirique à large spectre suivie d'une antibiothérapie spécifique aux résultats de culture pour obtenir la meilleure couverture possible.

Genomic Characterization of Emerging Bacterial Uropathogen Neisseria meningitidis, Which Was Misidentified as Neisseria gonorrhoeae by Nucleic Acid Amplification Testing

Neisseria meningitidis and Neisseria gonorrhoeae are pathogenic bacteria that can cause human infections. While N. meningitidis infections are associated with bacterial meningitis and bacteremia, a strain of N. meningitidis, isolated from the urogenital system, has recently been associated with urethritis. As this strain is becoming prominent as an emerging pathogen, it is essential to assess identification tools for N. meningitidis and N. gonorrhoeae urogenital isolates. Consecutive N. meningitidis isolates recovered from urogenital cultures of symptomatic patients with presumptive diagnoses of gonorrhea and a random selection of N. gonorrhoeae isolates recovered from the same population within the same time frame were characterized with routine identification systems, antimicrobial susceptibility testing, and whole-genome sequencing. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), multilocus sequence typing, 16S rRNA gene sequence, and average nucleotide identity methods accurately identified 95% (18/19) of N. meningitidis and N. gonorrhoeae isolates. With the Aptima Combo 2 CT/NG test, 30% (3/10) of N. meningitidis isolates were misidentified as N. gonorrhoeae, but no misidentifications were found with the Xpert CT/NG nucleic acid amplification test (NAAT). Phylogenetic core genome and single nucleotide polymorphism (SNP)-based grouping analyses showed that urogenital N. meningitidis isolates were highly related and phylogenetically distinct from N. gonorrhoeae and respiratory N. meningitidis isolates but similar to urogenital N. meningitidis isolates from patients with urethritis in the United States. Urogenital N. meningitidis isolates were predominantly azithromycin resistant, while N. gonorrhoeae isolates were azithromycin susceptible. These data indicate that urogenital isolates of N. meningitidis can cause false-positive detections with N. gonorrhoeae diagnostic assays. Misidentification of urogenital N. meningitidis isolates may confound public health-related activities for gonorrhea, and future studies are needed to understand the impact on clinical outcome of N. meningitidis urogenital infection.

Repeat Episodes of Symptomatic Urethritis Due to a Uropathogenic Meningococcal Clade

In 2015, we identified a non-groupable clade of Neisseria meningitidis that causes urethritis in men (the US_NmUC). Because repeat infection is common with Neisseria gonorrhoeae, we examined whether reinfection also occurs with the US_NmUC. We provide evidence that men are susceptible to repeat episodes of urethritis from the US_NmUC.

Meningococcal disease and sexual transmission: urogenital and anorectal infections and invasive disease due to Neisseria meningitidis

Neisseria meningitidis is an obligate human commensal bacterium that frequently colonises the upper respiratory tract. Person-to-person transmission occurs via direct contact or through dispersion of respiratory droplets from a carrier of the bacteria, and can lead to invasive meningococcal disease. Rare sporadic cases of meningococcal urogenital and anorectal infections, including urethritis, proctitis, and cervicitis, have been reported, typically following orogenital contact with an oropharyngeal meningococcal carrier. The resulting infections were clinically indistinguishable from infections caused by Neisseria gonorrhoeae. Over the past two decades, there have also been multiple outbreaks across North America and Europe of invasive meningococcal disease among men who have sex with men (MSM). The responsible meningococci belong to a highly virulent and predominantly serogroup C lineage, including strains that are able to express nitrite reductase and grow in anaerobic environments, such as the urogenital and anorectal tracts. More recently, a distinct clade within this lineage has expanded to cause urethritis predominantly among men who have sex with women. Evolutionary events giving rise to this clade included the loss of the ability to express a capsule, and acquisition of several gonococcal alleles, including one allele encoding a highly efficient gonococcal nitrite reductase. Members of the clade continue to acquire gonococcal alleles, including one allele associated with decreased antibiotic susceptibility. This evolution has implications for the clinical and public health management of those who are infected and their close contacts, in terms of both antibiotic treatment, and prevention through vaccination.