The Laboratory Diagnosis of Neisseria gonorrhoeae: Current Testing and Future Demands

Advances in genotypic antimicrobialresistance testing: a comprehensive review

Antimicrobial resistance (AMR) represents a substantial threat to global public health, complicating the treatment of common infections and leading to prolonged illness and escalated healthcare expenses. To effectively combat AMR, timely and accurate detection is crucial for AMR surveillance and individual-based therapy. Phenotypic antibiotic resistance testing (AST) has long been considered the gold standard in clinical applications, serving as the foundation for clinical AMR diagnosis and optimized therapy. It has significantly contributed to ensuring patients' health and the development of novel antimicrobials. Despite advancements in automated culture-based AST technologies, inherent limitations impede the widespread use of phenotypic AST in AMR surveillance. Genotypic AST technologies offer a promising alternative option, exhibiting advantages of rapidity, high sensitivity, and specificity. With the continuous advancement and expanding applications of genotypic AST technologies, such as microfluidics, mass spectrometry, and high-resolution melting curve analysis, new vigor has been injected into the development and clinical implementation of genotypic AST technologies. In this narrative review, we discuss the principles, applications, and advancements of emerging genotypic AST methods in clinical settings. The comprehensive review aims to highlight the significant scientific potential of emerging genotypic AST technologies in clinical AMR diagnosis, providing insights to enhance existing methods and explore novel approaches.

Neisseria gonorrhoeae treatment failure to the recommended antibiotic regimen-Québec, Canada, 2015-19

OBJECTIVE

To describe Neisseria gonorrhoeae treatment failure to the recommended antimicrobial regimens (azithromycin, cefixime and ceftriaxone).

METHODS

Our study was a longitudinal analysis of treatment failures from an observational open cohort of gonococcal infection cases collected in Québec, Canada (n = 2547) between September 2015 and December 2019. Epidemiological and clinical data were collected using a self-administered questionnaire, direct case interviews and chart reviews. Antimicrobial susceptibility testing was performed using the agar dilution method. To be retained as a treatment failure, cases must have had (i) a laboratory-confirmed gonococcal infection; (ii) a documented treatment; (iii) a positive test of cure (TOC) performed within a defined period and (iv) no sexual contact (vaginal, oral or anal), even protected with a condom, between the beginning of treatment and the positive TOC. A broader definition, including suspected cases, was also examined.

RESULTS

Among 1593 cases where a TOC was performed, 83 had a positive TOC: 11 were retained as treatment failure, and 6 were considered suspected cases (overall = 17/1593; 1.1%). Possible explanations for retained or suspected treatment failure included resistance to the antibiotics used for treatment (n = 1), pharyngeal infection (n = 9, of which 5 had been treated with ceftriaxone and 4 with other regimens); and azithromycin monotherapy (n = 1). Some cases had more than one potential explanation.

CONCLUSIONS

Treatment failure occurred in 1.1% of cases of Neisseria gonorrhoeae infection for which a TOC was performed, including some cases of pharyngeal infection treated with ceftriaxone.

Promoting molecular diagnostic equity: assessing in-house real-time PCR for Neisseria gonorrhoeae in anal samples from MSM recruited in an outpatient setting in Morocco

Objectives

Gonorrhea is a prevalent sexually transmitted infection among men who have sex with men (MSM). In Morocco, the basic laboratory diagnosis of Neisseria gonorrhoeae (NG) is based on microscopy and, in some settings, on culture. However, no nucleic acid amplification test (NAAT) has been implemented for routine diagnosis of gonorrhoeae.The aim of this study is to assess the effectiveness of an in-house real-time PCR test for detecting N. gonorrhoeae DNA in anal swabs samples collected during an Integrated Behavioral and Biological survey.

Patients and methods

Samples from 245 MSM, recruited using a Respondent Driven Sampling, were collected and tested for NG infection using GeneXpert CT/NG assay (Cepheid, USA). An In-House real-time PCR technique targeting the pseudo gene porA was developed and used for a parallel investigation of the same infection. The reliability of the in-house RT-PCR was validated through tests of reproducibility, repeatability, limit of detection, and cross-reactivity with other bacteria. The intrinsic performance characteristics of the qRT-PCR were assessed, namely, the sensitivity, the specificity, the positive predictive value (PPV), and the negative predictive value (NPV). The GeneXpert CT/NG assay was adopted as a reference method.

Results

For N. gonorrhoeae detection, the in-house real-time PCR assay showed a sensitivity and specificity of 80% and 100%, respectively. The PPV of the assay was 100% and the NPV was 97.3%.

Conclusion

The in-house real-time PCR assay has high specificity and sensitivity, and it emerges as a promising approach for detecting N. gonorrhoeae in clinical specimens, particularly in decentralized settings such as regional laboratories.

Performance evaluation of loop-mediated isothermal amplification, polymerase chain reaction and real-time polymerase chain reaction methods to detect Neisseria gonorrhoeae among symptomatic patients from India

Background: Neisseria gonorrhoeae is one of the most important causative organisms in causing sexually transmitted infections. The clinical presentation of gonorrhoea mimics the symptoms of other sexually transmitted infections, and a proper diagnosis of the same is therefore crucial in patient management. The current study intended to compare different in-house molecular methods: that is, conventional PCR, real-time PCR, and LAMP assay for detection of N. gonorrhoeae. Methods: A total of 163 samples were collected from 145 patients who presented with urethral and vaginal discharge. Collected samples were processed for culture on GC agar base, and three different molecular diagnostic tests (conventional PCR, real-time PCR, and LAMP assay) were performed simultaneously on all the samples. Results: Culture of N. gonorrhoeae was positive in 17 out of 21 (80.9%) swab samples. With culture as the gold standard method, conventional and real-time PCR had a sensitivity of 94.1%, whereas the sensitivity of the LAMP assay was found to be 88.2%. All three methods had a specificity of 100%. In addition to swab samples, evaluation of urine samples by different molecular methods yielded a good concordance with a kappa value of 0.85 by conventional PCR and real-time PCR showing a perfect level of agreement, while the LAMP assay was found to have a substantial level of agreement. Conclusion: LAMP assay had a comparable diagnostic accuracy to other molecular methods for the detection of N. gonorrhoeae and can be used as a point-of-care test in resource-limited settings.

A systematic review of Neisseria gonorrhoeae drug resistance development in South Africa

In South Africa, basic healthcare centres treat sexually transmitted infections (STIs) using a syndromic approach. In line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a complete study of all randomised controlled trials and surveillance data relevant to N. gonorrhoeae antibiotic resistance was conducted. To discover papers published between 2002 and 2022, searches were undertaken using PubMed, EMBASE and any other relevant databases. This systematic review extracted a total of 463 articles published between 2002 and 2022 from a variety of online research sources. Seven South African provinces were represented in the studies that were assessed. Mpumalanga and the North West Province did not have any studies that described the identification and monitoring of antimicrobial resistance (AMR). This study presents data obtained from a comprehensive analysis of 2140 isolates, in which we examined the presence of one or more antibiotic resistance. Our findings revealed that out of these samples, 1891 isolates exhibited antimicrobial properties; tetracycline was the antimicrobial resistance that was found the most often (30%), followed by ciprofloxacin (19%) and penicillin (17%). The mean of the isolates was 143, the upper 95% mean was 243, and the standard deviation (SD) was 181.6. All microbiological identification and susceptibility testing processes must be standardised and improved so national organisations can monitor AMR. The nation's health community must address all identified areas of concern to avoid AMR.

Integrated molecular, phenotypic and epidemiological surveillance of antimicrobial resistance in Neisseria gonorrhoeae in Germany

Numbers of infections with Neisseria gonorrhoeae are among the top three sexually transmitted infections (STI) worldwide. In addition, the emergence and spread of antimicrobial resistance (AMR) in Neisseria gonorrhoeae pose an important public-health issue. The integration of genomic, phenotypic and epidemiological data to monitor Neisseria gonorrhoeae fosters our understanding of the emergence and spread of AMR in Neisseria gonorrhoeae and helps to inform therapy guidelines and intervention strategies. Thus, the Gonococcal resistance surveillance (Go-Surv-AMR) was implemented at the Robert Koch Institute in Germany in 2021 to obtain molecular, phenotypic and epidemiological data on Neisseria gonorrhoeae isolated in Germany. Here, we describe the structure and aims of Go-Surv-AMR. Furthermore, we point out future directions of Go-Surv-AMR to improve the integrated genomic surveillance of Neisseria gonorrhoeae. In this context we discuss current and prospective sequencing approaches and the information derived from their application. Moreover, we highlight the importance of combining phenotypic and WGS data to monitor the evolution of AMR in Neisseria gonorrhoeae in Germany. The implementation and constant development of techniques and tools to improve the genomic surveillance of Neisseria gonorrhoeae will be important in coming years.

Maximizing the Neisseria gonorrhoeae confirmatory rate and the genotypic detection of ciprofloxacin resistance for samples screened with cobas CT/NG

Supplementary nucleic acid amplification testing for Neisseria gonorrhoeae (NG) is widely used to circumvent specificity problems associated with extragenital sites. Here, we compared different supplementary approaches for confirming NG-positive samples from the cobas 4800 CT/NG (c4800) and cobas 6800 CT/NG (c6800) assays using the ResistancePlusGC (RP-GC) assay, which in addition to detecting NG, also predicts ciprofloxacin susceptibility via NG gyrA characterization. Two different nucleic acid extraction techniques were investigated for RP-GC detection; extracts from c4800 (c4800-RP-GC) and MagNA Pure 96 (MP96-RP-GC). NG-positive (n = 300) and -negative (n = 150) samples in cobas PCR media from routine c4800 testing were retrospectively retested with c4800, c6800, c4800-RP-GC, and MP96-RP-GC. Selected samples were also tested with Xpert CT/NG (Xpert) for discrepant analysis. The gyrA status was compared to ETEST ciprofloxacin susceptibility or non-susceptibility for recovered isolates (n = 63). Extragenital confirmatory rates were higher for MP96-RP-GC (131/140; 93.6%) compared to c4800-RP-GC (126/146; 86.3%), albeit not significantly (P = 0.6677). Of 9 samples testing positive by c6800 and negative by MP96-RP-GC, 7/9 (77.8%) were also negative by Xpert. By contrast, the number of samples returning a valid gyrA status was significantly (P = 0.0003) higher for MP96-RP-GC (270/293; 92.2%) compared to c4800-RP-GC (245/298; 82.2%). The overall MP96-RP-GC gyrA status correlated 98.4% (61/62) with the reported ciprofloxacin sensitive (35/36; 97.2%) or non-susceptible (26/26; 100%) phenotype. Improved RP-GC confirmatory rates and reported gyrA status were observed using MP96 nucleic acids compared to c4800 extracts. The data further highlight the ongoing need for NG supplemental testing for oropharyngeal samples.

An isothermal CRISPR-based diagnostic assay for Neisseria gonorrhoeae and Chlamydia trachomatis detection

IMPORTANCE

A method for Neisseria gonorrhoeae (NG)/Chlamydia trachomatis (CT) detection is developed using multiplex-recombinase polymerase amplification and Cas12a/Cas13a. This method can detect NG and CT simultaneously with high sensitivity and specificity. This method has great potential to be further developed into larger-scale screening and point-of-care testing (POCT).

Impact of time of culture specimen collection on the recovery of Neisseria gonorrhoeae after a positive nucleic acid amplification test

OBJECTIVES

Culture of Neisseria gonorrhoeae remains essential for antimicrobial resistance (AMR) surveillance. We evaluated the effect of time of specimen collection on culture yield following a positive nucleic acid amplification test (NAAT).

METHODS

We retrospectively assessed N. gonorrhoeae culture yield among asymptomatic individuals (largely men who have sex with men) who attended for sexual health screening and had a positive NAAT. Participants underwent either same-day testing and notification (Drassanes Exprés) or standard screening with deferred testing.

RESULTS

Among 10 423 screened individuals, 809 (7.7%) tested positive for N. gonorrhoeae. A total of 995 different anatomical sites of infection culture was performed in 583 of 995 (58.6%) of anatomical sites (Drassanes Exprés 278 of 347, 80.1%; standard screening 305 of 648, 47.1%; p<0.001). Recovery was highest when culture specimens were collected within 3-7 days of screening with only a slight drop in recovery when the interval extended to 7 days . Recovery from pharynx was 38 of 149 (25.5%) within 3 days, 19 of 81 (23.4%) after 4-7 days (p=0.7245), 11 of 102 (10.7%) after 8-14 days (p<0.0036) and 1 of 22 (4.5%) with longer delays (p=0.00287). Recovery from rectum was 49 of 75 (65.3%) within 3 days, 28 of 45 (62.2%) after 4-7 days (p=0.7318), 41 of 69 (59.4%) after 8-14 days (p=0.4651) and 6 of 18 (33.3%) with longer delays (p=0.0131). Median culture specimen collection time was 1 day within Drassanes Exprés vs 8 days within standard screening. Consequently, the overall culture yield was slightly higher within Drassanes Exprés (102/278, 36.6% vs 99/305, 32.5%; p=0.2934).

CONCLUSION

Reducing the interval between screening and collection of culture specimens increased N. gonorrhoeae recovery in extragenital samples. Implementing a same-day testing and notification programme increased collection of culture samples and culture yield in our setting, which may help AMR surveillance.

Selection of DNA Aptamers Against Neisseria gonorrhoeae Causing Sexually Transmitted Infection (STI)

Neisseria gonorrhoeae (NG) is the second most common bacterial sexually transmitted infection (STI) worldwide. Gonorrhoea is a very serious infection because if untreated, it can lead to significant ramifications to reproductive, maternal, & newborn health and increase transmission of HIV. Infections are very often asymptomatic and symptoms when present manifest differently in men and women. The cornerstone of gonorrhoea control is to assure rapid diagnosis and prompt treatment of patients to prevent the onward spread of infection. The resource-rich settings are utilizing nucleic acid amplification tests (NAATs) for diagnosis, whereas resource-limited settings like ours where laboratory infrastructure is lacking, reliance is placed on syndromic approach. In view of the limitations of each, there is a compelling need for development of a point of care test (POCT). Aptamers offer such potential. These are short oligonucleotides that bind to its target with high affinity and specificity and therefore can be maneuvred for use in diagnostics. In this study, we performed live cell-SELEX (Systematic Evolution of Ligands by EXponential enrichment) to select 12 single-stranded DNA (ssDNA) aptamers that bind strongly to a cocktail of Neisseria gonorrhoeae strains, with Kd values ranging from 8.58 to 596 nM. Gold nanoparticle (GNP) assay revealed that one of the aptamers, E8 19 was highly specific for Neisseria gonorrhoeae (Kd = 24.5 nM). More importantly, it did not demonstrate any binding to Neisseria meningitidis and commensal Neisseria sp. The identified aptamer holds much promise for the development of a rapid test for diagnosis of gonorrhoea.

Rapid Minimum Inhibitory Concentration (MIC) Analysis Using Lyophilized Reagent Beads in a Novel Multiphase, Single-Vessel Assay

Antimicrobial resistance (AMR) is a global threat fueled by incorrect (and overuse) of antibiotic drugs, giving rise to the evolution of multi- and extreme drug-resistant bacterial strains. The longer time to antibiotic administration (TTA) associated with the gold standard bacterial culture method has been responsible for the empirical usage of antibiotics and is a key factor in the rise of AMR. While polymerase chain reaction (PCR) and other nucleic acid amplification methods are rapidly replacing traditional culture methods, their scope has been restricted mainly to detect genotypic determinants of resistance and provide little to no information on phenotypic susceptibility to antibiotics. The work presented here aims to provide phenotypic antimicrobial susceptibility testing (AST) information by pairing short growth periods (~3-4 h) with downstream PCR assays to ultimately predict minimum inhibitory concentration (MIC) values of antibiotic treatment. To further simplify the dual workflows of the AST and PCR assays, these reactions are carried out in a single-vessel format (PCR tube) using novel lyophilized reagent beads (LRBs), which store dried PCR reagents along with primers and enzymes, and antibiotic drugs separately. The two reactions are separated in space and time using a melting paraffin wax seal, thus eliminating the need to transfer reagents across different consumables and minimizing user interactions. Finally, these two-step single-vessel reactions are multiplexed by using a microfluidic manifold that allows simultaneous testing of an unknown bacterial sample against different antibiotics at varying concentrations. The LRBs used in the microfluidic system showed no interference with the bacterial growth and PCR assays and provided an innovative platform for rapid point-of-care diagnostics (POC-Dx).

[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.

PivNG primers and probes set used in the cobas omni Utility Channel is a reliable supplemental test for detection of Neisseria gonorrhoeae in oropharyngeal, urogenital and rectal specimens collected in cobas PCR Media

OBJECTIVE

To evaluate the clinical performance of the novel PivNG primers and probes set (PivNG test) used in the cobas omni Utility Channel for supplemental testing of Neisseria gonorrhoeae (NG).

METHODS

Oropharyngeal, urogenital and rectal samples were self-collected during routine testing at Barts Health sexual health clinics, London, UK. Samples were tested by the cobas CT/NG test and PivNG cobas omni Utility Channel test on cobas 6800/8800 Systems. Supplemental testing was carried out with the Xpert CT/NG test. PivNG overall percent agreements, positive percent agreements (PPAs)/negative percent agreements (NPAs) and positive/negative predictive values were calculated for each sample type. Microscopy and/or culture data were included for a randomised subset of concordant/discordant results, and a composite reference standard (cobas CT/NG, Xpert CT/NG and culture results) adjusted for partial verification bias was used to determine PivNG PPA and NPA.

RESULTS

Of 447 evaluable samples with valid results from all three assays (cobas CT/NG, PivNG and Xpert CT/NG), 288 (64.4%) were NG-positive by both PivNG and cobas CT/NG; 117 (26.2%) were NG-negative in both tests; and 42 (9.4%) had discordant results (with NG-negative supplementary Xpert) CT/NG results in 40/42 instances). Of 19 PivNG/Xpert CT/NG-discordant samples, 11 were confirmed NG-positive by microscopy and/or culture results. PivNG PPA and NPA were 100% and 91% for oropharyngeal swabs, 100% and 100% for vaginal swabs, 100% and 100% for male urine samples, and 100% and 97% for rectal swabs, respectively, compared with the partially adjusted composite reference standard.

CONCLUSIONS

PivNG is a reliable supplementary test with high sensitivity for confirming NG infection when used in conjunction with the cobas CT/NG test and samples collected in cobas PCR Media. Moreover, the PivNG test offers a convenient, high-throughput solution for supplemental NG testing of various sample types, with the potential to reduce the number of indeterminate reports.

A retrospective evaluation of the Euroarray STI-11 multiplex system for the detection of eight STI causing agents

With an incidence of more than > 1,000,000/day, sexually transmitted diseases remain a major challenge for health care systems worldwide. To reduce disease burden, complications, and spread, rapid diagnosis permitting early therapy is pivotal. The range of pathogens is wide and co-infections are common. This complicates pre-analytics, which are based on different laboratory techniques with potentially long turnaround times, e.g., cultivation and multistep serologies. Multiplex PCR provides the opportunity to overcome these limitations. In this study, we evaluated a novel assay, the Euroarray STI-11 microarray (EA; Euroimmun Medizinische Labordiagnostika), for the detection of eight obligate or facultative pathogens. Three-hundred-thirteen clinical specimens, which had been tested and pre-characterized for STI causing agents as part of routine diagnostics, were used as cases and controls in this retrospective study. The EA detected 34/44 Chlamydia trachomatis, 48/50 HSV-1, 50/50 HSV-2, 48/48 Mycoplasma hominis, 45/47 Neisseria gonorrhoeae, 9/11 Treponema pallidum, 46/46 Ureaplasma parvum, and 49/49 Ureaplasma urealyticum infections, respectively. 293 samples were EA positive, with polymicrobial infections (positive for two to six microbial or viral agents) detected in 130/293 cases. Specificities were 100% in the respective control groups (n = 18-48 depending on targeted pathogen) except for N. gonorrhoeae (25/26) and U. urealyticum (44/45). The broad spectrum of obligate and facultative pathogens targeted by the EA makes it a valuable tool in the setting of STI diagnostics and surveillance. The test has the potential to diagnose diseases neglected or overlooked in routine clinical practice. Besides a low sensitivity for C. trachomatis, the EA demonstrated high performance for all analyzed parameters. Further studies are warranted in order to capture a larger variety of the tested pathogens.

Challenges in Managing Gonorrhea and New Advances in Prevention

Gonorrhea is the second most common bacterial sexually transmitted infection in the United States. Rates are increasing, and multiple challenges compound management, including worsening antimicrobial resistance. New therapeutics, enhanced screening and partner notification, and treatment through point-of-care testing and expedited partner therapy, as well as primary prevention efforts provide opportunities for success in combating these trends.

Rapid Molecular Phenotypic Antimicrobial Susceptibility Test for Neisseria gonorrhoeae Based on Propidium Monoazide Viability PCR

Neisseria gonorrhoeae (NG) is an urgent threat to antimicrobial resistance (AMR) worldwide. NG has acquired rapid resistance to all previously recommended treatments, leaving ceftriaxone monotherapy as the first and last line of therapy for uncomplicated NG. The ability to rapidly determine susceptibility, which is currently nonexistent for NG, has been proposed as a strategy to preserve ceftriaxone by using alternative treatments. Herein, we used a DNA-intercalating dye in combination with NG-specific primers/probes to generate qPCR cycle threshold (Ct) values at different concentrations of 2 NG-relevant antimicrobials. Our proof-of-concept dual-antimicrobial logistic regression model based on the differential Ct measurements achieved an AUC of 0.93 with a categorical agreement for the susceptibility of 84.6%. When surveying the performance against each antimicrobial separately, the model predicted 90 and 75% susceptible and resistant strains, respectively, to ceftriaxone and 66.7 and 83.3% susceptible and resistant strains, respectively, to ciprofloxacin. We further validated the model against the individual replicates and determined the accuracy of the model in classifying susceptibility agnostic of the inoculum size. We demonstrated a novel PCR-based approach to determine phenotypic ciprofloxacin and ceftriaxone susceptibility information for NG with reasonable accuracy within 30 min, a significant improvement compared to the conventional method which could take multiple days.

Leak-proof probe for accurate detection of Neisseria gonorrhoeae by recombinase polymerase amplification-mediated lateral flow strip

Neisseria gonorrhoeae is the only pathogen contributing to gonorrhea, a common infectious disease. Clinically, approximately 50-80% of female and 40% of male patients are asymptomatic, and these carriers are the key to gonorrhea transmission. The rapid detection of N. gonorrhoeae recessive infection is vital to curb the spread of gonorrhea. Therefore, the development of a specific, sensitive, rapid, and convenient method for the diagnosis of N. gonorrhoeae is a priority. In this study, we identified the highly conserved fitA gene of N. gonorrhoeae as a detection target through bioinformatics analysis. Then, we constructed a convenient, economical, and effective biosensor to detect N. gonorrhoeae without false-positive results based on recombinase polymerase amplification-mediated lateral flow strip by leak-proof probe. The biosensor has high sensitivity, is capable of detecting N. gonorrhoeae at concentrations as low as 10² copies/μL within 28 min, and has high specificity, which allows N. gonorrhoeae to be differentiated from other genito-urinary bacteria and fungi. Finally, this biosensor has been successfully applied to the detection of N. gonorrhoeae in clinical samples, and the results have been consistent with those determined using qRT-PCR.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium among Patients with Urogenital Symptoms in Istanbul

Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium are the three most commonly reported sexually transmitted bacteria. The present study aimed to investigate the presence of C. trachomatis, N. gonorrhoeae, and M. genitalium in urogenital samples collected from 18-68-year-old Turkish patients who were admitted to the hospital with various urogenital symptoms. A total of 360 patients with symptoms of STD were included in the study. Following DNA extraction by QIAamp Mini Kit, the presence of C. trachomatis, N. gonorrhoeae, and M. genitalium were investigated using multiplex real-time PCR. Causative organisms were identified in 68 (18.9%) of 360 patients. C. trachomatis, N. gonorrhoeae, and M. genitalium were detected in 40 (11.1%), 14 (3.9%), and 28 (7.8%) of the patients, respectively. Patients 21-30 years of age represented more than one-third (37.8%) of positive patients. Of all patients, dual infections of C. trachomatis-M. genitalium, N. gonorrhoeae-C. trachomatis, N. gonorrhoeae-M. genitalium, and triple infection of C. trachomatis-N. gonorrhoeae-M. genitalium were determined in 1.6% (6/360), 1.3% (5/360), 0.2% (1/360), and 0.2% (1/360) of the patients, respectively. In CT-, NG-, and MG-positive patients, different STI agents were also found such as HIV, HBV, HPV, HSV2, T. pallidum, and T. vaginalis. In conclusion, among C. trachomatis, N. gonorrhoeae, and M. genitalium, CT was the most frequently detected bacterial cause of STDs in our hospital at Istanbul. Co-infections, which comprise more than one-fifth of the cases, should not be underestimated. Regular screening and following up of STD agents using multiplex real-time PCR-based diagnostic methods enabling the immediate detection of co-infections are essential for the treatment and primary prevention of STDs.

Global prevalence of Neisseria gonorrhoeae infection in pregnant women: a systematic review and meta-analysis

BACKGROUND

Neisseria gonorrhoeae infection (gonorrhoea) is associated with several pregnancy complications, including preterm labour, spontaneous abortion, stillbirth, miscarriage, growth retardation, and intrauterine death.

OBJECTIVES

We performed a systematic review and meta-analysis to estimate the global and regional prevalence of gonorrhoea in pregnant women as a scientific basis for further studies.

DATA SOURCES

We systematically searched PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO databases from inception to 10 July 2022.

STUDY ELIGIBILITY CRITERIA

We included cross-sectional, cohort, and case-control studies that reported the prevalence of gonorrhoea in pregnant women. In addition, we included baseline data for randomized controlled trials.

PARTICIPANTS

Pregnant women who were tested for gonorrhoea.

METHODS

Pooled prevalence estimates at 95% CIs were calculated using a random-effects meta-analysis model. We stratified countries according to WHO-defined regions and socio-economic factors. Moreover, sub-group-, meta-regression, and sensitivity analyses were conducted to investigate the effects of pre-determined factors on prevalence estimates and heterogeneity.

RESULTS

We identified 235 studies (249 datasets) on 19 104 175 pregnant women from 71 countries. The worldwide pooled prevalence of gonorrhoea in pregnant women was estimated at 1.85% (95% CI 1.73-1.97%), with the highest rate in the African region (3.53%) (2.84-4.29%) and the lowest rate in the European region (0.52%) (0.27-0.84%). Overall, the prevalence estimates were high among low-income countries (3.03%), pregnant women with HIV (2.81%), and pregnant women <20 years old (8.06%). A significant decreasing trend in prevalence was observed over time (β = -0.0008, 95% CI -0.0012 to -0.0004, p 0.001).

DISCUSSION

Our findings indicate that a substantial number of pregnant women have been infected with gonorrhoea globally, which calls for immediate public health measures to reduce the potential risk of infection. The study highlights the inadequacy or lack of data for many countries, emphasizing the need to expand systematic data collection efforts at national and regional levels.

Abnormal vaginal discharge among women of reproductive age in sub-Saharan Africa: the need for a paradigm shift from a syndromic approach to specific pathogen identification and directed treatment

Background

An abnormal vaginal discharge is a frequent manifestation of reproductive tract infections, including sexually transmitted infections (STIs) and vulvovaginal candidiasis. It is also a manifestation of bacterial vaginosis, which has a prevalence of up to 50% among women of reproductive age. Reproductive tract infections are associated with a range of reproductive health challenges and increase the risk of HIV acquisition.

Methods

This study was performed to critically review and discuss the current diagnostic and treatment approaches to abnormal vaginal discharge among women of reproductive age in sub-Saharan Africa, and to call for a paradigm shift from the syndromic approach to specific pathogen identification and directed antimicrobial therapy.

Discussion

Young women have the highest incidence of HIV infection in sub-Saharan Africa. Countries in sub-Saharan Africa where the prevalence of both STIs and bacterial vaginosis is very high have been employing a syndromic approach for the treatment of abnormal vaginal discharge since around 1984. However, the syndromic approach has several limitations, with the potential to miss infections, over-diagnose and over-treat STIs, and propagate antimicrobial resistance, which is one of the greatest global health challenges of the 21st century.

Conclusions

The low to middle-income countries of sub-Saharan Africa must innovate and leverage improved diagnostics to capacitate primary health care and other levels for point-of-care diagnostic testing, in order to provide an immediate diagnosis and treatment for women with an abnormal vaginal discharge.

Resistance profiles of Neisseria gonorrhoeae isolates in Vienna, Austria: a phenotypic and genetic characterization from 2013 to 2020

OBJECTIVES

International surveillance data show a constant rise in the number of Neisseria gonorrhoeae infections and an increase in drug resistance of N. gonorrhoeae. As recent N. gonorrhoeae surveillance data in Austria are scarce, this study investigated phenotypic and genotypic antimicrobial resistance in N. gonorrhoeae isolates.

METHODS

In total, 440 N. gonorrhoeae samples were collected at the Medical University of Vienna, and the minimal inhibitory concentrations (MICs) for a range of different antibiotics were determined. Sampling sites and treatments were recorded, and whole-genome sequencing of N. gonorrhoeae isolates was performed using allele libraries to determine genotypic resistance.

RESULTS

The median MICs for ceftriaxone, cefixime, azithromycin, ciprofloxacin, tetracycline and penicillin were <0.002 µg/mL, <0.016 µg/mL, 0.25 µg/mL, 2.0 µg/mL, 1.5 µg/mL and 0.25 µg/mL, respectively. Annual comparison showed that MICs were generally stable for all antimicrobial agents except azithromycin, for which an increase in median MIC was observed from 2017 (0.25 µg/mL). There was no genetic resistance to ceftriaxone; 8% of samples displayed resistance mutations against cefixime, primarily located in the penA gene. Resistance to azithromycin increased from 2% in 2013 to 12% in 2020. MtrD mosaic had the highest impact on azithromycin susceptibility; 47% of the resistant isolates showed this mutation. The majority of cases of gonorrhoea were treated successfully with either ceftriaxone or a ceftriaxone/azithromycin regime. Two treatment failures occurred under monotherapy with doxycycline. Overall, genotypic resistance corresponded significantly to all respective MICs.

CONCLUSIONS

The resistance rate of N. gonorrhoeae to antibiotics has remained stable in Vienna over the last decade, except for azithromycin. The strong correlation found between genetic and phenotypic patterns in this study holds promise for future diagnostics of N. gonorrhoeae resistance based on genotypes.

Research on point-of-care tests in outpatient care in Germany: A scoping review and definition of relevant endpoints in evaluation studies

BACKGROUND

The fast turnaround time and user-friendliness of point-of-care tests (POCTs) offer a great potential to improve outpatient health care where clinical decisions have to be made during the physician-patient encounter and time resources are limited. The aim of this scoping review is to describe the extent and nature as well as gaps in German research activities on POCT in outpatient care. In addition, we define research endpoints that should be addressed in the comprehensive evaluation of POCTs targeted for outpatient care.

METHODS

We performed a scoping review with a systematic literature search in Medline (via PubMed), Scopus, Web of Science, Cochrane library and Google Scholar for German publications on POCT with relevance to German outpatient care published from January 2005 to November 2020.

RESULTS

Our literature search identified 2,200 unique records. After literature selection 117 articles were included in this scoping review. Just over half of the articles (67/117, 57.3%) were primary research studies with original data, while one third of all the studies (33.3%) were secondary research articles (e.g., review articles). The remaining articles were clinical recommendations / position papers (7/117, 6.0%) and other types of articles (3.4%). The majority of articles focused on POCT use in infectious diseases (44/117, 37.6%), diabetic syndromes (15.4%), cardiac disease (12.0%) or coagulopathies and thrombosis (10.3%), while the remaining articles did not specify the disease (13.7%) or investigated other diseases (11.1%). Similar to international studies, most primary research studies investigated the diagnostic performance of POCT (e.g., sensitivity, specificity). Evidence beyond diagnostic accuracy remains scarce, such as the impact on therapeutic decisions and practice routines, clinical effectiveness, and user perspectives. In line with this, interventional studies (such as RCTs) on the effectiveness of POCT use in German outpatient care are limited. We define six endpoint domains that should be addressed in the evaluation of POCTs targeted for outpatient care: (i) diagnostic performance, (ii) clinical performance, (iii) time and costs, (iv) impact on clinical routines / processes, (v) perspectives of medical professionals and patients, and (vi) broader aspects.

CONCLUSION

There is considerable research activity on POCTs targeted for use in outpatient care in Germany. Data on their potential benefits beyond diagnostic accuracy is often lacking and should be addressed in future POCT research studies.

Benign Anorectal Disorder Management in Low-Resource Settings

There are many benign anorectal disorders, which can make patients seek care. In low-resource settings, the incidence of those pathologies is not different from the industrialized and western world. However, an interesting difference colorectal surgeons and gastroenterologists can face is the fact that many patients do not seek help or are not aware and have little opportunities to be helped. Latin America population is estimated to be around 8% of the world population, with Brazil having the largest percentage. Infectious diseases, which were previously under control or were steadily declining, have emerged. For example, we have seen resurgence of dengue, malaria, and syphilis in pregnancy, as well as other sexually transmitted diseases that can affect the anorectal region. In this article, we will address the most common benign anorectal disorders.

Neisseria gonorrhoeae culture growth rates from asymptomatic individuals with a positive nucleic acid amplification test

Gonorrhoea infections are frequently diagnosed at extragenital locations in asymptomatic individuals and are historically related to poor recovery in culture, which hinders antimicrobial susceptibility testing. The aim of this study was to evaluate recovery rates of N. gonorrhoeae by culture among asymptomatic individuals who tested positive by nucleic acid amplification tests between 2018 and 2019 in Barcelona (Spain). In total, 10,396 individuals were tested for N. gonorrhoeae on first-void urine, rectal, pharyngeal, and/or vaginal swabs depending on sexual behaviour. Overall infection prevalence was 5.5% (95% confidence interval [CI] 5.0 to 5.9%). Seven hundred and ten samples were positive corresponding to 567 individuals. The most common site of infection was the pharynx (71.3%), followed by rectum (23.1%) and genitals (4.7%) (p<0.0001). The N. gonorrhoeae recovery rate in culture, time from positive screening to culture specimen, and inoculation delay were calculated. Recovery rate was 21.7% in pharynx, 66.9% in rectum, and 37.0% in genitals (25.0% vagina, 71.4% urethra) (p<0.0001). Median culture collection time was 1 [0; 3] days, and median inoculation delay was 5.01 [4.99-7.99] hours, with no impact on N. gonorrhoeae recovery, p=0.8367 and p=0.7670, respectively. Despite efforts towards optimizing pre-analytical conditions, the N. gonorrhoeae recovery rate in asymptomatic individuals is unacceptably low (especially for pharynx), representing a problem for monitoring antimicrobial-resistant infections.

Rapid Detection of Neisseria gonorrhoeae Genomic DNA Using Gold Nanoprobes Which Target the Gonococcal DNA Uptake Sequence

The rapid spread of antimicrobial resistant Neisseria gonorrhoeae continues to pose a serious threat to global health. To successfully treat and control gonococcal infections, rapid diagnosis is critical. Currently, nucleic acid amplification tests are the recommended diagnostic, however, these are both technically demanding and time consuming, making them unsuitable for resource-poor clinics. Consequently, there is a substantial need for an affordable, point-of-care diagnostic to use in these settings. In this study, DNA-functionalised gold nanoparticles (gold nanoprobes), with the ability to specifically detect the DNA Uptake Sequence (DUS) of Neisseria gonorrhoeae, were prepared. Using complementary annealing, the gold nanoprobes were shown to hybridise to genomic gonococcal DNA, causing a significant shift in their salt stability. By exploiting the shift in nanoprobe stability under the presence of target DNA, a solution-based colorimetric diagnostic for gonococcal DNA was prepared. Detection of purified genomic DNA was achieved in under 30 minutes, with a detection limit of 15.0 ng. Significantly, testing with DNA extracted from an off-target control organism suggested specificity for Neisseria. These results highlight the potential of DUS-specific gold nanoprobes in the rapid point-of-care diagnosis of gonococcal infections.

Epidemiology of symptomatic infective anoproctitis in a population of men having sex with men (MSM)

PURPOSE

Anoproctitis due to Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are Sexual Transmitted Infections (STIs) reported in MSM population. This study describes clinical and microbiological epidemiology of infective anoproctitis in MSM population.

METHODS

All patients with symptomatic anoproctitis consulting at the proctology Institute of Saint-Joseph's Hospital, Paris, were included. Detection of CT/NG was performed by PCR GeneXpert^R and other STIs pathogens Mycoplasma sp., HSV, CMV and T. pallidum were detected by multiplex PCR Allplex (mPCR).

RESULTS

Symptoms most frequently reported were pain, rectal bleeding and purulent flow in 66%, 52% and 49% of cases, respectively. On the 311 rectal samples collected, 171 (55.2%) were positive to CT/NG. Among the 194 used for mPCR, 148 were positive to STIs pathogens (76.2%) including 106 samples (71.6%) positive in coinfections. Among NG infections, 22.6% of the strains were resistant to azithromycin and 26.8% to tetracyclines.

CONCLUSIONS

Anorectal infections in this MSM population showed a high prevalence of not only CT/NG but also other pathogens involved in STIs. The high level of coinfections confirms the requirement of accurate PCR tests to improve diagnosis. This study describing increasing antibiotic resistances for NG strains confirms the updating of international guidelines on antibiotic treatments recommendations.

Bridging the gap between development of point-of-care nucleic acid testing and patient care for sexually transmitted infections

The incidence rates of sexually transmitted infections (STIs), including the four major curable STIs - chlamydia, gonorrhea, trichomoniasis and, syphilis - continue to increase globally, causing medical cost burden and morbidity especially in low and middle-income countries (LMIC). There have seen significant advances in diagnostic testing, but commercial antigen-based point-of-care tests (POCTs) are often insufficiently sensitive and specific, while near-point-of-care (POC) instruments that can perform sensitive and specific nucleic acid amplification tests (NAATs) are technically complex and expensive, especially for LMIC. Thus, there remains a critical need for NAAT-based STI POCTs that can improve diagnosis and curb the ongoing epidemic. Unfortunately, the development of such POCTs has been challenging due to the gap between researchers developing new technologies and healthcare providers using these technologies. This review aims to bridge this gap. We first present a short introduction of the four major STIs, followed by a discussion on the current landscape of commercial near-POC instruments for the detection of these STIs. We present relevant research toward addressing the gaps in developing NAAT-based STI POCT technologies and supplement this discussion with technologies for HIV and other infectious diseases, which may be adapted for STIs. Additionally, as case studies, we highlight the developmental trajectory of two different POCT technologies, including one approved by the United States Food and Drug Administration (FDA). Finally, we offer our perspectives on future development of NAAT-based STI POCT technologies.

Surveillance for Disseminated Gonococcal Infections, Active Bacterial Core surveillance (ABCs) - United States, 2015-2019

BACKGROUND

Disseminated gonococcal infections (DGI) are thought to be uncommon; surveillance is limited and case reports are analyzed retrospectively or in case clusters. We describe the population-level burden of culture-confirmed DGI through the Active Bacterial Core surveillance (ABCs) system.

METHODS

During 2015-2016, retrospective surveillance was conducted among residents in two ABCs areas and prospectively in three ABCs areas during 2017-2019. A DGI case was defined as isolation of Neisseria gonorrhoeae (Ng) from a normally sterile site. A case report form was completed for each case and antimicrobial susceptibility testing (AST) was performed on available isolates.

RESULTS

During 2015-2019, 77 DGI cases were identified (~a rate of 0.13 cases per 100,000 population) and accounted for 0.06% of all reported gonorrhea cases in the three surveillance areas. Most DGI cases were male (64%), non-Hispanic Black (68%), and ranged from 16-67 years; blood (55%) and joint (40%) were the most common sterile sites. Among 29 isolates with AST results during 2017-2019, all were susceptible to ceftriaxone.

CONCLUSIONS

DGI is an infrequent complication of Ng; since Ng can quickly develop antimicrobial resistance, continued DGI surveillance, including monitoring trends in antimicrobial susceptibility, could help inform DGI treatment recommendations.

Placental acute inflammation infiltrates and pregnancy outcomes: a retrospective cohort study

Chorioamnionitis can be either an infection or a sterile inflammation. This study aims to analyze the prevalence of acute inflammatory lesions of the placenta, the association with a positive result of the microbiological examination, and the fetal-maternal outcomes. This retrospective study considered all single, consecutive pregnancies and their placental pathological examination during 2014-2017. The evidence of funisitis, chorionic vasculitis, and chorioamnionitis was assessed by a pathologist, including stage and grade. Moreover, maternal fever, placental microbiological examination, and neonatal outcomes were also recorded. Among the 5910 pregnancies in the considered period, 1770 had a placental pathological examination, and 358 (6.06%) had acute placental inflammation. Microbiological examination was performed in 125 cases, revealing 64 cases with a positive microbiological outcome. In the presence of acute placental inflammation, there was a higher rate of neonatal cardiopulmonary resuscitation, admission to neonatal intensive care unit, and postnatal death of the newborn. Multivariate analysis inferred that acute inflammation of membranes was a risk factor for neonatal cardiopulmonary resuscitation (OR 2.12; CI.95 1.36-3.31; p < 0.05), acute funisitis was a risk factor for admission to intensive neonatal care unit (OR 3.2; CI.95 1.67-6.12; p < 0.05), and chorionic vasculitis was a risk factor for postnatal death of the newborn (OR 5.38; CI.95 1.37-21.06; p < 0.05). The prevalence of chorioamnionitis was 6.06%, and about half of the cases were sterile inflammation. Chorioamnionitis was associated with higher rates of adverse fetal and neonatal outcomes; in particular, chorionic vasculitis was a risk factor for postnatal death.

Detection and Drug Susceptibility Testing of Neisseria gonorrhoeae Using Isothermal Microcalorimetry

Background: Gonorrhea is a frequently encountered sexually transmitted disease that results in urethritis and can further lead to pelvic inflammatory disease, infertility, and possibly disseminated gonococcal infections. Thus, it must be diagnosed promptly and accurately. In addition, drug susceptibility testing should be performed rapidly as well. Unfortunately, Neisseria gonorrhoea is a fastidious microorganism that is difficult to grow and requires culturing in an opaque medium. Methods: Here, we used isothermal microcalorimetry (IMC) to monitor the growth and the antimicrobial susceptibility of N. gonorrhoea. Results: Using IMC, concentrations of N. gonorrhoea between 2000 and 1 CFU·mL⁻¹ were detected within 12 to 33 h. In addition, drug susceptibility could be monitored easily. Conclusions: The use of isothermal microcalorimetry provides an interesting and useful tool to detect and characterize fastidious microbes such as N. gonorrhoea that require media incompatible with optical detection conventionally used in many commercial systems.

A Nanoparticle-Based Biosensor Combined With Multiple Cross Displacement Amplification for the Rapid and Visual Diagnosis of Neisseria gonorrhoeae in Clinical Application

Gonorrhea is a sexually transmitted disease caused by the host-adapted human pathogen, Neisseria gonorrhoeae. The morbidity is increasing and poses a major public health concern, especially in resource-scarce regions. Therefore, a rapid, visual, sensitive, specific, cost-saving, and simple assay for N. gonorrhoeae detection is critical for prompt treatment and the prevention of further transmission. Here, for the first time, we report a novel assay called the multiple cross displacement amplification combined with gold nanoparticle-based lateral flow biosensor (MCDA-LFB), which we constructed for the rapid and visual identification of N. gonorrhoeae in clinical samples. We successfully devised a set of MCDA primers based on the N. gonorrhoeae-specific gene, orf1. Optimal assay conditions were determined at 67°C, including genomic DNA preparation (∼15 min), MCDA amplification (30 min), and LFB reading (∼2 min), which can be completed within 50 min. The limit of detection (LoD) of the assay was 20 copies/test (in a 25-μl reaction mixture). Assay specificity was 100%, with no cross-reactions with other pathogens. Thus, our N. gonorrhoeae-MCDA-LFB is a rapid, specific, visual, cost-saving, and easy-to-use assay for N. gonorrhoeae diagnostics, and may have great potential for point-of-care (POC) testing in clinical settings, especially in resource-limited regions.

Prediction of ceftriaxone MIC in Neisseria gonorrhoeae using DNA microarray technology and regression analysis

BACKGROUND

Decreased susceptibility of Neisseria gonorrhoeae to extended-spectrum cephalosporins is a major concern. Elucidation of the phenotypic and genetic characteristics of such isolates is a priority task.

METHODS

We developed a method for predicting the N. gonorrhoeae ceftriaxone susceptibility level (MICcro) by identifying genetic determinants of resistance using low-density hydrogel microarrays and a regression equation. A training dataset, containing 5631 isolates from the Pathogenwatch database and 181 isolates obtained in the Russian Federation during 2018-19, was used to build a regression model. The regression equation was tested on 14 WHO reference strains. Ceftriaxone resistance determinants for the 448 evaluated clinical isolates collected in Russia were identified using microarray analysis, and MICcro values were calculated using the regression equation and compared with those measured by the serial dilution method.

RESULTS

The regression equation for calculating MICcro values included 20 chromosomal resistance determinants. The greatest contributions to the increase in MICcro were shown to be PBP2: Ala-501→Pro, Ala-311→Val, Gly-545→Ser substitutions, Asp(345-346) insertion; and PorB: Gly-120→Arg substitution. The substitutions PBP2: Ala-501→Thr/Val, PorB: Gly-120→Asn/Asp/Lys and PBP1: Leu-421→Pro had weaker effects. For 94.4% of the isolates in the evaluation set, the predicted MICcro was within one doubling dilution of the experimentally determined MICcro. No ceftriaxone-resistant isolates were identified in the analysed samples from Russia, and no interpretative errors were detected in the MICcro calculations.

CONCLUSIONS

The developed strategy for predicting ceftriaxone MIC can be used for the continuous surveillance of known and emerging resistant N. gonorrhoeae isolates.

Visual and Rapid Diagnosis of Neisseria gonorrhoeae Using Loop-Mediated Isothermal Amplification Combined With a Polymer Nanoparticle-Based Biosensor in Clinical Application

Neisseria gonorrhoeae is a host-adapted human pathogen that causes sexually transmitted gonorrhea and remains to be a serious global public health challenge, especially in low- and middle-income regions. It is vital to devise a reliable, simple, cost-saving, and easy-to-use assay for detecting the N. gonorrhoeae agent. In the current study, we firstly report a novel approach, loop-mediated isothermal amplification linked with a polymer nanoparticle-based biosensor (LAMP-PNB), that was used for identifying N. gonorrhoeae in clinical samples. The results showed that the LAMP primers based on the orf1 gene were valid for development of the N. gonorrhoeae-LAMP-PNB assay. The detection system with optimal conditions could be performed at a fixed temperature of 64°C for 40 min. The whole process, including genomic DNA preparation (approximately 10 min), LAMP reaction (40 min), and PNB reporting (approximately 2 min), could be accomplished within 60 min. The limit of detection (LoD) of the N. gonorrhoeae-LAMP-PNB assay was 50 copies per test. The specificity of the current assay was 100%, and no cross-reactions to non-N. gonorrhoeae isolates were observed. These results confirmed that the N. gonorrhoeae-LAMP-PNB technique is a reliable, specific, sensitive, rapid, low-cost, and easy-to-use method for detecting gonococci isolates. More importantly, this assay has great potential to develop a point-of-care (POC) testing method in clinical practice, especially in resource-constrained regions.

A profile of the binx health io® molecular point-of-care test for chlamydia and gonorrhea in women and men

Introduction: Point-of-care (POC) tests for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are urgently needed to control the STI epidemic in order to offer patients an immediate diagnoses and accurate treatment before they leave a clinical encounter and thus reduce transmission and sequelae. Nucleic acid amplification tests (NAATs) have increased sensitivity and specificity, but very few POC assays can provide results of such tests within the usual time of the patient visit.Areas covered: This review describes the technology and performance characteristics of the binx health io® [Boston, MA] (binx io) CT/NG assay, a new rapid molecular POC assay. The assay is compared to other available molecular POC tests. We also describe the importance of time to results and assay performance for this POC assay.Expert opinion: The binx io CT/NG assay offers the ability to incorporate the use of POC tests to identify and immediately treat chlamydia and gonococcal infections into the clinical visit, which will provide improved outcomes for patients. Additional implementation studies are needed to optimize the adoption of this new test.

Reactive Arthritis Update: Spotlight on New and Rare Infectious Agents Implicated as Pathogens

Purpose of Review

This article presents a comprehensive narrative review of reactive arthritis (ReA) with focus on articles published between 2018 and 2020. We discuss the entire spectrum of microbial agents known to be the main causative agents of ReA, those reported to be rare infective agents, and those reported to be new candidates causing the disease. The discussion is set within the context of changing disease terminology, definition, and classification over time. Further, we include reports that present at least a hint of effective antimicrobial therapy for ReA as documented in case reports or in double-blind controlled studies. Additional information is included on microbial products detected in the joint, as well as on the positivity of HLA-B27.

Recent Findings

Recent reports of ReA cover several rare causative microorganism such as Neisseria meningitides, Clostridium difficile, Escherichia coli, Hafnia alvei, Blastocytosis, Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, Entamoeba histolytica/dispar, Strongyloides stercoralis, β-haemolytic Streptococci, Mycobacterium tuberculosis, Mycoplasma pneumoniae, Mycobacterium bovis bacillus Calmette-Guerin, and Rickettsia rickettsii. The most prominent new infectious agents implicated as causative in ReA are Staphylococcus lugdunensis, placenta- and umbilical cord–derived Wharton’s jelly, Rothia mucilaginosa, and most importantly the SARS-CoV-2 virus.

Summary

In view of the increasingly large spectrum of causative agents, diagnostic consideration for the disease must include the entire panel of post-infectious arthritides termed ReA. Diagnostic procedures cannot be restricted to the well-known HLA-B27-associated group of ReA, but must also cover the large number of rare forms of arthritis following infections and vaccinations, as well as those elicited by the newly identified members of the ReA group summarized herein. Inclusion of these newly identified etiologic agents must necessitate increased research into the pathogenic mechanisms variously involved, which will engender important insights for treatment and management of ReA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11926-021-01018-6.

Neisseria gonorrhoeae Multivalent Maxibody with a Broad Spectrum of Strain Specificity and Sensitivity for Gonorrhea Diagnosis

Gonorrhea is one of the most common, but still hidden and insidious, sexually transmitted diseases caused by Neisseria gonorrhoeae (gonococci). However, the diagnosis and treatment of gonorrhea are hampered by antigenic variability among gonococci, the lack of acquired immunity, and antimicrobial resistance. Further, strains resistant to cephalosporins, including ceftriaxone, the last line of defense, represent a growing threat, which prompted us to develop gonococci-specific diagnostic antibodies with broad-spectrum binding to gonococci strains to generate gonorrhea-detecting reagents. This study reports the identification of gonococci antibodies via bio-panning on gonococci cells using scFv-phage libraries. Reformatting the lead scFv-phage Clones 1 and 4 to a multivalent scFv1-Fc-scFv4 maxibody increased the sensitivity by up to 20-fold compared to the single scFv-Fc (maxibody) alone. Moreover, the multivalent maxibody showed broader cross-reactivity with clinical isolates and the ceftriaxone antibiotic-resistant World Health Organization (WHO) reference strain L. In contrast, the selected antibodies in the scFv-phage, maxibody, and multivalent maxibody did not bind to N. sicca, N. meningitides, and N. lactamica, suggesting the clinical and pharmaceutical diagnostic value of these selected antibodies for gonorrheal infections. The present study illustrates the advantages and potential application of multivalent maxibodies to develop rapid and sensitive diagnostic reagents for infectious diseases and cancer.

Current and Future Trends in the Laboratory Diagnosis of Sexually Transmitted Infections

Sexually transmitted infections (STIs) continue to exert a considerable public health and social burden globally, particularly for developing countries. Due to the high prevalence of asymptomatic infections and the limitations of symptom-based (syndromic) diagnosis, confirmation of infection using laboratory tools is essential to choose the most appropriate course of treatment and to screen at-risk groups. Numerous laboratory tests and platforms have been developed for gonorrhea, chlamydia, syphilis, trichomoniasis, genital mycoplasmas, herpesviruses, and human papillomavirus. Point-of-care testing is now a possibility, and microfluidic and high-throughput omics technologies promise to revolutionize the diagnosis of STIs. The scope of this paper is to provide an updated overview of the current laboratory diagnostic tools for these infections, highlighting their advantages, limitations, and point-of-care adaptability. The diagnostic applicability of the latest molecular and biochemical approaches is also discussed.

Aptamer-Based Detection of Ampicillin in Urine Samples

The misuse of antibiotics in health care has led to increasing levels of drug resistant infections (DRI's) occurring in the general population. Most technologies developed for the detection of DRI's typically focus on phenotyping or genotyping bacterial resistance rather than on the underlying cause and spread of DRI's; namely the misuse of antibiotics. An aptameric based assay has been developed for the monitoring of ampicillin in urine samples, for use in determining optimal antibiotic dosage and monitoring patient compliance with treatment. The fluorescently labelled aptamers were shown to perform optimally at pH 7, ideal for buffered clinical urine samples, with limits of detection as low as 20.6 nM, allowing for determination of ampicillin in urine in the clinically relevant range of concentrations (100 nM to 100 µM). As the assay requires incubation for only 1 h with a small sample volume, 50 to 150 µL, the test would fit within current healthcare pathways, simplifying the adoption of the technology.

Neisseria gonorrhoeae Infections

Gonorrhea is a sexually transmitted disease with a high morbidity burden. Despite having guidelines for its treatment, the incidence of the disease follows an increasing trend worldwide. This is mainly due to the appearance of antibiotic-resistant strains, inefficient diagnostic methods and poor sexual education. Without an effective vaccine available, the key priorities for the control of the disease include sexual education, contact notification, epidemiological surveillance, diagnosis and effective antibiotic treatment. This Special Issue focuses on some of these important issues such as the molecular mechanisms of the disease, diagnostic tests and different treatment strategies to combat gonorrhea.