Gonorrhea

Microfluidic systems for infectious disease diagnostics

Microorganisms, encompassing both uni- and multicellular entities, exhibit remarkable diversity as omnipresent life forms in nature. They play a pivotal role by supplying essential components for sustaining biological processes across diverse ecosystems, including higher host organisms. The complex interactions within the human gut microbiota are crucial for metabolic functions, immune responses, and biochemical signalling, particularly through the gut-brain axis. Viruses also play important roles in biological processes, for example by increasing genetic diversity through horizontal gene transfer when replicating inside living cells. On the other hand, infection of the human body by microbiological agents may lead to severe physiological disorders and diseases. Infectious diseases pose a significant burden on global healthcare systems, characterized by substantial variations in the epidemiological landscape. Fast spreading antibiotic resistance or uncontrolled outbreaks of communicable diseases are major challenges at present. Furthermore, delivering field-proven point-of-care diagnostic tools to the most severely affected populations in low-resource settings is particularly important and challenging. New paradigms and technological approaches enabling rapid and informed disease management need to be implemented. In this respect, infectious disease diagnostics taking advantage of microfluidic systems combined with integrated biosensor-based pathogen detection offers a host of innovative and promising solutions. In this review, we aim to outline recent activities and progress in the development of microfluidic diagnostic tools. Our literature research mainly covers the last 5 years. We will follow a classification scheme based on the human body systems primarily involved at the clinical level or on specific pathogen transmission modes. Important diseases, such as tuberculosis and malaria, will be addressed more extensively.

An Evasive Case of Gonococcal Endocarditis

Neisseria gonorrhoeae is one of the most common sexually transmitted infections in the United States, and disseminated infection can lead to a variety of complications. This includes the less common, but potentially life-threatening complication of gonococcal endocarditis. The authors report a case of a formerly incarcerated middle-aged man with a three-day history of dyspnea on exertion, fever, headache, and productive cough with green sputum. He endorsed a several-week history of an untreated right molar infection but denied any history of genitourinary symptoms. Given concerns for heart failure, a transthoracic echocardiogram was obtained showing mitral regurgitation with a mass on the mitral valve leaflet, as well as a smaller aortic valve mass that was subsequently confirmed with a transesophageal echocardiogram. Initially, the patient was transferred from an outside hospital (OSH), and discrepancies were noted between the blood cultures obtained at the OSH and a private lab. Given that the patient was already started on antibiotics prior to transfer, a Karius assay was sent and returned positive for N. gonorrhoeae. He was started on empiric antibiotic coverage before ultimately undergoing mitral valve replacement with a mosaic valve. The patient completed six weeks of intravenous ceftriaxone with complete resolution of symptoms. This case demonstrates a rare incident of N. gonorrhoeae bacteremia without any common symptoms causing endocarditis and valvular destruction. Timely diagnosis, a multidisciplinary approach, and treatment of gonococcal endocarditis led to positive outcomes in this case.

Actions of a Novel Bacterial Topoisomerase Inhibitor against Neisseria gonorrhoeae Gyrase and Topoisomerase IV: Enhancement of Double-Stranded DNA Breaks

Novel bacterial topoisomerase inhibitors (NBTIs) are an emerging class of antibacterials that target gyrase and topoisomerase IV. A hallmark of NBTIs is their ability to induce gyrase/topoisomerase IV-mediated single-stranded DNA breaks and suppress the generation of double-stranded breaks. However, a previous study reported that some dioxane-linked amide NBTIs induced double-stranded DNA breaks mediated by Staphylococcus aureus gyrase. To further explore the ability of this NBTI subclass to increase double-stranded DNA breaks, we examined the effects of OSUAB-185 on DNA cleavage mediated by Neisseria gonorrhoeae gyrase and topoisomerase IV. OSUAB-185 induced single-stranded and suppressed double-stranded DNA breaks mediated by N. gonorrhoeae gyrase. However, the compound stabilized both single- and double-stranded DNA breaks mediated by topoisomerase IV. The induction of double-stranded breaks does not appear to correlate with the binding of a second OSUAB-185 molecule and extends to fluoroquinolone-resistant N. gonorrhoeae topoisomerase IV, as well as type II enzymes from other bacteria and humans. The double-stranded DNA cleavage activity of OSUAB-185 and other dioxane-linked NBTIs represents a paradigm shift in a hallmark characteristic of NBTIs and suggests that some members of this subclass may have alternative binding motifs in the cleavage complex.

Polymicrobial Prosthetic Valve Endocarditis Due to Neisseria gonorrhoeae and Pseudomonas fluorescens in a Patient With Tetralogy of Fallot: A Case Report

Disseminated gonococcal infections are rare clinical entities and a few progress to endocarditis. Endocarditis caused by Pseudomonasis even more infrequent, with the few reported cases associated with either intravenous drug use, prosthetic heart valves, or pacemakers. We report a case of a 25-year-old male patient with Tetralogy of Fallot presenting with anasarca and diagnosed with endocarditis due to Neisseria gonorrhoeae and Pseudomonas fluorescens. To our knowledge, this is the first case of tissue-proven infective endocarditis due to P. fluorescens with concomitant N. gonorrhoeae bacteremia. Clinical management of polymicrobial endocarditis in young adults includes obtaining a detailed sexual history, using multiple diagnostic methods to confirm endocarditis, and promptly initiating broad-spectrum antibiotic therapy.

Meningococcal Carriage in 'Men Having Sex With Men' With Pharyngeal Gonorrhoea

We assessed the characteristics of Neisseria meningitidis pharyngeal carriage in a cohort of ‘men having sex with men’, including patients with pharyngeal Neisseria gonorrhoeae infection. In the period 2017-2019, among all the oropharyngeal samples tested for gonorrhoea from MSM attending a STI Clinic in Bologna (Italy), we randomly selected 244 N. gonorrhoeae-positive samples and 403 negatives (n=647). Pharyngeal specimens were tested for N. meningitidis presence, by the detection of sodC gene. N. meningitidis-positive samples were further grouped by PCR tests for the major invasive genogroups (i.e., A, B, C, W, and Y). A molecular assay, targeting capsule transporter gene, was used to determine meningococcal capsular status. Overall, 75.8% (491/647) of samples tested positive for sodC gene, indicating a pharyngeal meningococcal carriage. Meningococcal colonisation was significantly more frequent in younger subjects (P=0.009), with no association with HIV infection. Non-groupable meningococci represented most of pharyngeal carriages (about 71%). The commonest N. meningitidis serogroup was B (23.6%), followed by C (2.1%), Y (1.8%) and W (1.1%). Meningococci were often characterized by the genetic potential of capsule production. Interestingly, a negative association between N. meningitidis and N. gonorrhoeae was found: pharyngeal gonorrhoea was significantly more present in patients without meningococcal carriage (P=0.03). Although preliminary, our data added knowledge on the epidemiology of meningococcal carriage in MSM communities at high risk of gonococcal infections, gaining new insights into the interactions/dynamics between N. meningitidis and N. gonorrhoeae.

Gonococcal Infective Endocarditis Returns

Disseminated gonococcal infection occurs in 0.5%-3% of gonorrhea cases, usually in the form of either a triad of arthralgia, tenosynovitis, and skin lesions or purulent arthritis. Other rare complications include gonococcal infective endocarditis that occurs in 1%-2% of cases with 99 cases reported in the literature since 1938. Our case presents an additional rare case of aortic valve gonococcal endocarditis requiring surgical intervention and a prolonged antibiotic course, despite the absence of genitourinary symptoms or mucosal evidence of infection. This case was found to have sepsis and gonococcal endocarditis, which was clearly confirmed with positive blood cultures and aortic valve vegetation. It was further complicated by the evidence of splenic embolization and severe aortic regurgitation requiring surgical valve replacement and debridement of an annular perivalvular abscess. A high degree of suspicion is needed to early diagnose these unusual cases of gonococcal endocarditis, especially in sexually active individuals, for its known virulence causing valve destruction and high mortality. Our case represents a valuable addition to the reported cases of this diagnosis and is complemented by a short literature review.

Role of Vaginal Microbiota Dysbiosis in Gynecological Diseases and the Potential Interventions

Vaginal microbiota dysbiosis, characterized by the loss of Lactobacillus dominance and increase of microbial diversity, is closely related to gynecological diseases; thus, intervention on microbiota composition is significant and promising in the treatment of gynecological diseases. Currently, antibiotics and/or probiotics are the mainstay of treatment, which show favorable therapeutic effects but also bring problems such as drug resistance and high recurrence. In this review, we discuss the role of vaginal microbiota dysbiosis in various gynecological infectious and non-infectious diseases, as well as the current and potential interventions.

Gonococcal endocarditis: A rare manifestation of a common disease in the COVID-19 era

Gonococcal infections have been increasing worldwide and in the United States. Rarely, Neisseria gonorrhoeae can cause disseminated disease, including endocarditis. We present a case of gonococcal endocarditis, confirmed by blood cultures and 16S rRNA sequencing on excised valvular tissue. Prior to presentation with heart failure, our patient was asymptomatic. Most gonococcal infections are diagnosed through routine screening of individuals at risk. During the COVID-19 pandemic, healthcare contact for nonurgent complaints has decreased, and test kit shortage has been a factor. With increased incidence and decreased opportunities for screening, healthcare providers should be aware of rising gonococcal infections, as well as potential complications.

Genital Tract Infection during Pregnancy and its Association with Preterm Delivery

Genital tract infection (GTI) remains a significant health concern. It is estimated that in 2016, there were 370 million people who suffer from chlamydia, gonorrhea, and trichomoniasis; and 708 million others suffer from genital herpes and condyloma acuminatum. It has been reported that in pregnant women, GTI is associated with preterm delivery. The mechanisms of GTI-associated preterm delivery need to be further understood to prevent neonatal mortality and morbidity that could be the risk factor for neonates’ growth and development disorders. This article aims to describe various types of GTI and the associated pathogenesis causing preterm birth. A literature search was conducted to retrieve recent articles published in English from online databases including Pubmed, ScienceDirect, and Google Scholar. This literature study found that GTI evokes inflammatory responses that trigger several mechanisms leading to preterm delivery. The inflammatory responses in GTI include the production of proinflammatory cytokines and robust activation of neutrophils. The key mechanisms that stimulate preterm delivery in GTI include the events of early uterine contraction, preterm premature rupture of membranes, and induction of cervical ripening; which are under normal circumstances in a full-term pregnancy, those mechanisms are regulated by progesterone and prostaglandin levels along with suppression of the inflammatory responses. In conclusion, this paper has described the underlying mechanisms of preterm delivery in pregnant women with ISG. However, such mechanisms remain unclear in candida and gonococcal infection; thus, prompting the need for further studies. 

Surveillance and molecular epidemiology of Neisseria gonorrhoeae isolates in Shenzhen, China, 2010-2017

OBJECTIVES

The development and emergence of antimicrobial resistance in Neisseria gonorrhoeae (NG) have become a major public-health problem worldwide. This study aimed to analyse the antimicrobial susceptibility and molecular characteristics of NG isolates in Shenzhen, China.

METHODS

A total of 1282 NG isolates were consecutively collected between 2010 and 2017. Patient demographic information was also collected. MICs of ceftriaxone, spectinomycin, ciprofloxacin, azithromycin and penicillin were determined by agar dilution. Isolates were genotyped using N. gonorrhoeae multi-antigen sequence typing (NG-MAST).

RESULTS

Among the isolates, 97.4% were resistant to ciprofloxacin and 68.2% to penicillin. Moreover, 5.0% showed decreased susceptibility to ceftriaxone (CRO^D) and 17.3% were resistant to azithromycin (AZM-R); 1.3% were simultaneously CRO^D and AZM-R. All isolates were susceptible to spectinomycin. Increasing ceftriaxone MICs were found from 2010 to 2017. A total of 427 sequence types (STs) and 68 genogroups were identified from 724 isolates. ST5061, ST3741 and ST1766 were observed across the study years. ST14638 (n = 3) was predominant among 32 CRO^D isolates. Prevalent STs were ST5061 (n = 6), ST1866 (n = 5) and ST11133 (n = 5) among 96 AZM-R isolates.

CONCLUSIONS

A high prevalence of isolates resistant to ciprofloxacin and penicillin was found in this study. Azithromycin, one antimicrobial of dual antimicrobial therapy recommended by the WHO, showed a high prevalence of resistance. The other, ceftriaxone, can be used continuously in this region owing to lower resistance levels. However, the emergence of CRO^D and decreasing susceptibility to ceftriaxone indicate that continuous antimicrobial resistance surveillance is essential.

Effectiveness of Bazhengsan formula as an adjunctive therapy to ceftriaxone for female patients with uncomplicated gonorrhea: A pilot study

BACKGROUND

This pilot study aimed to investigate the feasible effectiveness and safety of Bazhengsan formula (BZSF) as an adjunctive therapy to ceftriaxone for female patients with uncomplicated gonorrhea.

METHODS

This pilot randomized controlled trial compared BZSF as an adjunctive therapy to ceftriaxone with ceftriaxone alone for Chinese female patients with uncomplicated gonorrhea. A total of 40 eligible patients were randomly allocated to a treatment group (received BZSF and ceftriaxone) or a control group (received ceftriaxone alone). All patients in both groups were treated for a total of 10 days. The primary outcome included bacteriological cure. It was assessed by the eradication of urogenital gonorrhea at any site cultured after taken the study medications. The secondary outcome was clinical response. For the safety assessment, adverse events were recorded during the study period.

RESULTS

After treatment, patients in both groups achieved promising effectiveness. However, no significant differences in bacteriological cure (P = .34), clinical response (P = .11), and safety were found between 2 groups.

CONCLUSION

The findings of this study showed that BZSF as an adjunctive therapy to ceftriaxone may be not superior to the ceftriaxone alone for Chinese female patients with uncomplicated gonorrhea after 10 days treatment.

Maternal Prenatal Screening and Serologies

BACKGROUND

Maternal prenatal screening is essential in preventing pregnancy complications as well as preventing and/or predicting neonatal and infant medical issues after delivery that are due to certain communicable diseases.

PURPOSE

This article is aimed at gathering and presenting the most recent information regarding the most common prenatal screening laboratory studies and the implications with the various diseases.

METHODS/SEARCH STRATEGY

An extensive medical database search was performed and the most relevant medical texts regarding the subject of prenatal screening were obtained.

FINDINGS/RESULTS

Maternal screenings should be performed at the first provider visit once pregnancy has been confirmed. Additional screenings vary based on the specific disease and on maternal risk factors. Methods of screenings involve measuring antigen or antibody titers, a combination of antigen/antibody titers, or by specialized genetic tests.

IMPLICATIONS FOR PRACTICE

Providers responsible for pregnant women should be able to identify which diseases they need to screen for and how to interpret the findings. Neonatal providers should be able to interpret the findings and they should also be able to manage neonates appropriately.

IMPLICATIONS FOR RESEARCH

Future research should be aimed at developing better, cost-effective tests for both existing diseases and new diseases that either impact large or small populations of pregnant women and their fetuses.

Vaginal Lactobacilli Reduce Neisseria gonorrhoeae Viability through Multiple Strategies: An in Vitro Study

The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae (GC) underline the need of “antibiotic-free” strategies for the control of gonorrhea. The aim of this study was to assess the anti-gonococcal activity of 14 vaginal Lactobacillus strains, belonging to different species (L. crispatus, L. gasseri, L. vaginalis), isolated from healthy pre-menopausal women. In particular, we performed “inhibition” experiments, evaluating the ability of both lactobacilli cells and culture supernatants in reducing GC viability, at two different contact times (7 and 60 min). First, we found that the acidic environment, associated to lactobacilli metabolism, is extremely effective in counteracting GC growth, in a pH- and time-dependent manner. Indeed, a complete abolishment of GC viability by lactobacilli supernatants was observed only for pH values < 4.0, even at short contact times. On the contrary, for higher pH values, no 100%-reduction of GC growth was reached at any contact time. Experiments with organic/inorganic acid solutions confirmed the strict correlation between the pH levels and the anti-gonococcal effect. In this context, the presence of lactate seemed to be crucial for the anti-gonococcal activity, especially for pH values in the range 4.4–5.3, indicating that the presence of H⁺ ions is necessary but not sufficient to kill gonococci. Moreover, experiments with buffered supernatants led to exclude a direct role in the GC killing by other bioactive molecules produced by lactobacilli. Second, we noticed that lactobacilli cells are able to reduce GC viability and to co-aggregate with gonococci. In this context, we demonstrated that released-surface components with biosurfactant properties, isolated from “highly-aggregating” lactobacilli, could affect GC viability. The antimicrobial potential of biosurfactants isolated from lactobacilli against pathogens has been largely investigated, but this is the first report about a possible use of these molecules in order to counteract GC infectivity. In conclusion, we identified specific Lactobacillus strains, mainly belonging to L. crispatus species, able to counteract GC viability through multiple mechanisms. These L. crispatus strains could represent a new potential probiotic strategy for the prevention of GC infections in women.