Mycoplasma genitalium: A Review

An overview regarding the relationship between Mollicutes, infertility and antibiotic resistance (Review)

Throughout the past decades, physicians have increasingly conferred regarding the role of Mollicutes in infertility in both male and female patients. Although Ureaplasma and Mycoplasma do not represent a leading cause of infertility, whether dermatovenerologists, gynecologists and urologists should not disregard them when screening patients with infertility problems is discussed in the present review. While these infections are completely asymptomatic in ~80% of cases, they do lead to both chronic inflammation of the genital tract and reproductive disorders. Different Mollicute strains and/or serovars, genomic traits and proteomic markers have been examined in order to understand not only the exact mechanism by which they cause infertility, but also their relationship with the worldwide spreading resistance to antibiotics. The current review provided an overview of the latest studies regarding the new findings on the relationship between Mollicutes, infertility and antibiotic resistance. Awareness should be raised among clinicians to screen sexually active adults wishing to conceive who have failed to achieve a pregnancy; in addition, an antibiogram should be performed and treatment should be carried out according to the guidelines.

Mycoplasma genitalium's Antibiotic Resistance in Sexually Transmitted Infections Clinics in Israel

OBJECTIVES

To determine the prevalence of antibiotic resistance rate in Mycoplasma genitalium, and distribution of mutations associated with this resistance, among patients that attended sexually transmitted infections (STI) investigation clinics.

MATERIALS AND METHODS

This cross-sectional study included M. genitalium-positive samples (urine, vaginal, rectal, and pharyngeal swabs) collected from 170 patients attending two STI investigation clinics, which were subjected to macrolide and quinolone resistance mutations analyses. Data regarding patient age, sex, and material/anatomical site of testing were collected.

RESULTS

Macrolide-resistance mutations were identified in 48.8% of samples and were more common among males (p < .0001) and in rectal samples (p < .05). A2059C was the most prevalent macrolide-resistance mutation (18.2%). Quinolone resistance was detected in 23% of the samples, with S83I being the most common (17.1%) mutation. Rate of co-resistance to macrolides and quinolones was 21.2%.

CONCLUSIONS

The high rate of antibiotic resistance found in the current study, especially to macrolides, underscores the importance of antibiotic resistance monitoring in M. genitalium isolates in cases of persistent or recurrent urethritis/cervicitis, in cases of treatment failure and among specific populations. Such surveillance will improve treatment regimens and cure rates.

Intervention effects of low-molecular-weight chondroitin sulfate from the nasal cartilage of yellow cattle on lipopolysaccharide-induced behavioral disorders: regulation of the microbiome-gut-brain axis

Chondroitin sulfate (CS) is a sulfated linear polysaccharide with different functional activities, including antioxidant, anti-inflammatory, lipid-lowering, and immune regulation. As natural sulfated polysaccharides have high molecular weight, high apparent viscosity, low water solubility, complex structure, and high negative charge, they have difficulty binding to receptors within cells across tissue barriers, resulting in low bioavailability and unclear structure-activity relationships. In this study, an H2O2-Vc oxidative degradation system was employed to perform environmentally friendly and controllable degradation of CS extracted from the nasal cartilage of Shaanxi Yellow cattle. Two low-molecular-weight chondroitin sulfates (LMWCSs), CS-1 (14.8 kDa) and CS-2 (50.9 kDa), that exhibit strong in vitro free radical scavenging ability were obtained, and their structures were characterized. Mice intraperitoneally administered lipopolysaccharide (LPS) were used to explore the cognitive intervention effects of LMWCS. Supplementing CS-1 and CS-2 significantly downregulated the levels of the serum inflammatory factors, TNF-α and IL-1β, promoted the expression of GSH in the brain, and inhibited the production of the lipid peroxidation product, malondialdehyde (MDA), ultimately inhibiting LPS-induced cognitive impairment in mice. Surprisingly, compared to the LPS model group, the abundances of Streptococcus, Eisenbergiella, Vampirovibrio, Coprococcus, Enterococcus and Lachnoanaerobaculum were significantly increased in the intestines of mice in the CS-1 and CS-2 group, whereas those of Parabacteroides and Mycoplasma were significantly decreased. Altogether, this study provides a theoretical basis for the comprehensive utilization of agricultural and animal resources and the application of brain nutrition, anti-inflammatory, and LMWCS health products.

Osteomyelitis of the femur caused by Metamycoplasma orale in an immunocompromised patient using metagenomic next-generation sequencing: A case report

Background

Metamycoplasma orale (M.orale), a symbiotic bacterium observed in the human oral cavity, is generally regarded as non-pathogenic to humans. Although infrequent, symptomatic infections caused by M.orale may occur in individuals with compromised humoral immunity. Accurate identification and early diagnosis of M.orale still present significant challenges due the limitations associated with conventional detection methods. Although metagenomic next-generation sequencing (mNGS) is currently widely utilized in clinical practices and exhibits a remarkable specificity and sensitivity for detecting various pathogens, its application in the diagnosis of M.orale-induced osteomyelitis remains largely unexplored.

Case description

In this report, we present a case study of osteonecrosis caused by M.orale in a 20-year-old female patient with nephrotic syndrome and other comorbidities. She was administered long-term hormone therapy and immunosuppressants, leading to her admission to the hospital due to recurrent fever, hip abscess and left thigh pain. Imaging examination revealed bilateral mid-femoral lesions, with the extensive nature of the left femoral lesion suggesting a potential secondary infection. Although no pathogen was detected in pus culture, mNGS analysis identified M.orale in the sample. Following treatment with doxycycline and levofloxacin, the patient's symotoms improved and she was discharged with favorable outcomes.

Conclusion

mNGS enables rapid identification of etiology in patients with osteomyelitis caused by the rare pathogen M.orale. This case accentuate the strength of mNGS for early detection and targeted clinical treatment of infectious diseases caused by uncommon pathogens.

Computational approach for identifying immunogenic epitopes and optimizing peptide vaccine through in-silico cloning against Mycoplasma genitalium

Mycoplasma genitalium is a pathogenic microorganism linked to a variety of severe health conditions including ovarian cancer, prostate cancer, HIV transmission, and sexually transmitted diseases. A more effective approach to address the challenges posed by this pathogen, given its high antibiotic resistance rates, could be the development of a peptide vaccine. In this study, we used experimentally validated 13 membrane proteins and their immunogenicity to identify suitable vaccine candidates. Thus, based on immunogenic properties and high conservation among other Mycoplasma genitalium sub-strains, the P110 surface protein is considered for further investigation. Later on, we identified T-cell epitopes and B-cell epitopes from the P110 protein to construct a multiepitope-based vaccine. As a result, the 'NIAPISFSFTPFTAA' T-cell epitope and 'KVKYESSGSNNISFDS' B-cell epitope have shown 99.53% and 87.50% population coverage along with 100% conservancy among the subspecies, and both epitopes were found to be non-allergenic. Furthermore, focusing on molecular docking analysis showed the lowest binding energy for MHC-I (-137.5 kcal/mol) and MHC-II (-183.3 kcal/mol), leading to a satisfactory binding strength between the T-cell epitopes and the MHC molecules. However, the constructed multiepitope vaccine (MEV) consisting of 54 amino acids demonstrates favorable characteristics for a vaccine candidate, including a theoretical pI of 4.25 with a scaled solubility of 0.812 and high antigenicity probabilities. Additionally, structural analyses reveal that the MEV displays substantial alpha helices and extended strands, vital for its immunogenicity. Molecular docking with the human Toll-like receptors TLR1/2 heterodimer shows strong binding affinity, reinforcing its potential to elicit an immune response. Our immune simulation analysis demonstrates immune memory development and robust immunity, while codon adaptation suggests optimal expression in E. coli using the pET-28a(+) vector. These findings collectively highlight the MEV's potential as a valuable vaccine candidate against M. genitalium.

Navigating fungal infections and antifungal stewardship: drug resistance, susceptibility testing, therapeutic drug monitoring and future directions

Antifungal stewardship refers to the rational use of antifungal agents. Historically, in some instances, the misuse or overuse of antifungal agents has predisposed patients to an elevated risk of systemic side-effects and treatment resistance, as well as increased healthcare costs. Superficial mycoses, such as onychomycosis, are sometimes treated without any diagnostic testing and is associated with a high likelihood of self-diagnosis and self-treatment, potentially leading to the emergence of resistance against commonly used antifungals like terbinafine. Practitioners need to ensure that a proper clinical diagnosis is backed up by appropriate testing. This may include the traditional light microscopy and culture; additionally, molecular techniques (such as polymerase chain reaction, terbinafine gene mutational analysis) and antifungal susceptibility testing are considerations as appropriate. The choice of antifungal agent should be guided by what is the standard of care in the location where the clinician practices as well as more broadly state and national prescription patterns. Recently, reports of treatment resistance concerning both superficial and deep fungal infections have added another layer of difficulty to clinical practice. This review aims to explore the phenomenon of antifungal drug resistance, and highlights the importance of adopting antifungal stewardship programs. We provide an overview of treatment resistance and mechanisms of resistance reported thus far in dermatophytes. Challenges of performing antifungal susceptibility testing and therapeutic drug monitoring are discussed, as well as principles, recommendations and future directions of antifungal stewardship programs.

A case of chronic bacterial prostatitis due to Mycoplasma genitalium

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

[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.

Detection of macrolide and fluoroquinolone resistance-associated 23S rRNA and parC mutations in Mycoplasma genitalium by nested real-time PCR

Background

Traditional drug susceptibility testing cannot be performed in clinical laboratories due to the slow-growing characteristics of Mycoplasma genitalium when cultured in vitro. Sanger sequencing is the standard method for detecting drug resistance-associated mutations. It has been used in some laboratories to guide the choice of macrolide antibiotics for Mycoplasma genitalium infected patients. Furthermore, resistance to fluoroquinolone has become another emerging clinical challenge.

Objective

Sequencing analysis can detect unknown mutations, but it is time-consuming, requires professional analytical skills and the appropriate testing equipment. The main objective of this study was to establish a nested real-time PCR method for the simultaneous detection of 23S rRNA and parC genotypes in relation to the macrolide and fluoroquinolone resistance.

Results

105 MG-positive samples and 27 samples containing other pathogens were used for validation. The limit of the nested real-time PCR detection was 500 copies/reaction and there was no cross-reaction with Ureaplasma urealyticum, Mycoplasma hominis, Chlamydia trachomatis, Neisseria gonorrhoeae, Human papillomavirus, Herpes simplex virus, Candida albicans and Ureaplasma parvum, but the 23S rRNA assay cross-reacted with Mycoplasma pneumoniae. Compared with sequencing results, the sensitivity of 23S rRNA was 100% (95% CI; 93.3 -100), the specificity was 94.3% (95% CI; 79.4 - 99.0), the overall consistency was 98% (95% CI; 92.5 - 99.7) and kappa value was 0.96 (P < 0.001); the sensitivity of parC was 100% (95% CI; 93.4 - 100), the specificity was 89.7% (95% CI; 71.5 - 97.3) and the overall consistency was 96.9% (95% CI; 90.7 - 99.2) with a kappa value of 0.92 (P < 0.001).

Conclusions

The results of this sensitive and rapid alternative for identifying resistant genotypes of Mycoplasma genitalium are intuitive and easy to interpret, especially for mixed MG populations. Although the relevant 23S rRNA primers need further adjustment, this reliable method would provide an effective diagnostic tool for the selection of antibiotics in clinical practice.

Prevalence and Factors Associated With Mycoplasma genitalium Infection in At-Risk Female Adolescents in Bronx County, New York

BACKGROUND

Mycoplasma genitalium infection can adversely affect female reproductive health, but data are limited about prevalence and characteristics of the infection in female adolescents. We employed a sensitive assay to detect M. genitalium infection, and we describe its characteristics in a clinical sample of women younger than 21 years.

METHODS

We recruited females aged 13 to 20 years in children's hospital clinics whose clinicians were testing for chlamydia/gonorrhea. Participants completed a questionnaire providing demographics, sexual history, and current symptoms. Urine/endocervical samples were tested for chlamydia/gonorrhea and partitioned for M. genitalium testing using Aptima M. genitalium assay. We reviewed records for the clinic visit to document examination, diagnosis, and results of sexually transmitted infection (STI) testing. We compared prevalence of M. genitalium infection by demographics, sexual history, symptoms, and signs.

RESULTS

Of 153 participants mean age 18.07 ± 1.68 years, 58% self-identified as Hispanic, 27% Black, 64% straight/heterosexual, 27% bisexual, 1% gay/lesbian, 29% reported a prior STI diagnosis. Prevalence of M. genitalium was 11.1% (17/153), 13 of 17 were asymptomatic, 2 of 17 had pelvic inflammatory disease (PID), 3 of 17 coinfected with chlamydia or gonorrhea. Prevalence of chlamydia was 6.6% and of gonorrhea 2.6%. A logistic regression model indicated independent associations of bisexual orientation versus all other orientations (adjusted odds ratio [aOR], 4.80; 95% confidence interval [CI], 1.38-16.67), self-reported prior STI (aOR, 3.83; 95% CI, 1.10-13.37), and self-reported prior PID (aOR, 9.12; 95% CI, 1.02-81.72) with higher odds of M. genitalium infection.

CONCLUSIONS

Findings suggest that in at-risk female populations younger than 21 years, M. genitalium is a prevalent STI and symptomatic adolescents may warrant testing and treatment. Further study of harms and benefits of testing asymptomatic bisexual female adolescents or those with prior STI/PID is needed.

Infective anoproctitis in men having sex with men: Don't forget Mycoplasma genitalium

OBJECTIVES

The aim was to describe the clinical characteristics of symptomatic anoproctitis and the occurrence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG) infections in a prospective cohort of MSM patients.

METHODS

From February 2018 to January 2020, all consecutive patients presenting at the Leopold Bellan Proctology Institute of Saint-Joseph Hospital, Paris, France with symptoms of anoproctitis were tested on rectal samples for C. trachomatis (CT), N. gonorrhoeae (NG), M. genitalium (MG). Clinical, microbiological, biological data, STI risk factors, medical history and treatments were collected.

RESULTS

Three hundred and sixty-five patients were included for suspected infective anoproctitis. CT was detected in 84/365 (23%) patients, NG in 45/365 (12%) and MG in 46/315 patients (15%), associated with macrolide resistance in 28/46 MG strains (61%). The most frequent symptoms were rectal pains, rectal bleeding, purulent discharge in 253 (79%), 191 (60%), and 164 (51%) of cases respectively. In comparison with MG infections, ulcerations, erythematous proctitis, rectorragia and false needs were more frequently described in CT infections, while purulent proctitis, functional pain and purulent discharge were more often observed in NG and CT anoproctitis.

CONCLUSION

We found a high prevalence rate of STIs due to CT, NG, while MG detection was associated with a high rate of macrolide resistance in a cohort of MSM patients. Our results confirm that in cases of symptomatic anoproctitis, MG should be tested in association with other STI pathogens.

Nickel exposure induces gut microbiome disorder and serum uric acid elevation

Serum uric acid elevation has been found in long-term nickel (Ni) exposure occupational workers, but the mechanism is unclear. In this study, the relationship between Ni exposure and uric acid elevation was explored in a cohort of 109 participants composed of a Ni-exposed workers group and a control group. The results showed that Ni concentration (5.70 ± 3.21 μg/L) and uric acid level (355.95 ± 67.87 μmol/L) in the serum were increased in the exposure group with a significant positive correlation (r = 0.413, p < 0.0001). The composition of gut microbiota and metabolome revealed that the abundance of uric acid-lowering bacteria, such as Lactobacillus, Lachnospiraceae_Unclassfied and Blautia were reduced while pathogenic bacteria including Parabacteriadies and Escherichia-Shigella were enriched in Ni group, accompanied by impaired intestinal degradation of purines and upregulated biosynthesis of primary bile acids. Consistent with human results, the mice experiments showed that Ni treatment significantly promotes uric acid elevation and systemic inflammation. Lactobacillus and Blautia in gut microbiota were reduced and inflammation-related taxa Alistipes and Mycoplasma were enriched in the Ni treatment. In addition, LC-MS/MS metabolomic analysis indicated that purine nucleosides were accumulated in mice feces, which increased purine absorption and uric acid elevation in the serum. In summary, this study provides evidence that UA elevation was correlated with heavy metals exposure and highlighted the role of gut microbiota in intestinal purine catabolism and in the pathogenesis of heavy metal-induced hyperuricemia.

Point-of-Care Amenable Detection of Mycoplasma genitalium and Its Antibiotic Resistance Mutations

Mycoplasma genitalium (MG) is an emerging sexually transmitted bacterium. Due to its fastidious and slow-growing nature, MG is difficult to detect through culture-based diagnostics. Like Neisseria gonorrheae, another bacterial pathogen linked to sexually transmitted infections (STIs), MG has developed resistance to macrolide and fluoroquinolone antibiotics used to treat STIs. The ability to detect MG and identify genomic mutations associated with antibiotic resistance simultaneously can enable antibiotic stewardship and mitigate the spread of antibiotic-resistant MG. Toward this end, we first developed a multiplexed probe-based PCR-melt assay that detects MG and the presence of macrolide resistance mutations in the 23S rRNA gene and fluoroquinolone resistance mutations in the parC gene. Each target was identified via its unique combination of fluorescence label and melting temperature. This approach allowed differentiation between the different types of mutations at the genes of interest. Following initial assay optimization, the assay was integrated into a droplet magnetofluidic cartridge used in a portable platform to integrate automated sample extraction, PCR amplification, and detection. Lastly, we demonstrated that the integrated assay and droplet magnetofluidic platform could detect MG and antibiotic resistance-associated mutations in clinical isolates spiked into urine samples in 40 min.

Prevalence of Mollicutes among men who have sex with men and transgender women aged 15 to 19 years in Salvador, North-eastern Brazil

BACKGROUND

Some species of Mollicutes have been associated with different pathologies of the urogenital tract in humans, with a high prevalence among adult men who have sex with men (MSM) and transgender women (TGW). However, few studies have been performed to investigate its prevalence among adolescents. In this study, we estimated the initial prevalence of Mycoplasma genitalium (MG), Mycoplasma hominis (MH), Ureaplasma urealyticum (UU), and Ureaplasma parvum (UP); the rate of misdiagnosis at different anatomical sites; and the associated factors with positive tests for Mollicutes among MSM and TGW aged 15 to 19 years enrolled in the PrEP1519 study.

METHODS

PrEP-1519 is the first study to investigate the effectiveness of pre-exposure prophylaxis for human immunodeficiency virus among adolescent MSM and TGW aged 15 to 19 in Latin America. Oral, anal, and urethral swabs were taken from 246 adolescents upon enrolment in the study to detect MG, MH, UU, and UP by quantitative polymerase chain reaction (qPCR). Bivariate and multivariate analyses were conducted by Poisson regression and 95% confidence intervals (95% CI) were estimated.

RESULTS

The prevalence of Mollicutes was 32.1%. UU was the most prevalent species (20.7%), followed by MH (13.4%), MG (5.7%), and UP (3.2%); 67.3% of the positive samples would have been missed if only urethral samples had been taken. Receptive anal sex (prevalence ratio [PR] = 1.79; 95% CI = 1.07-3.01) and clinical suspicion of sexually transmitted infection (PR = 1.62; 95% CI = 1.01-2.61) were factors associated with the detection of Mollicutes in general. Group sex (PR = 1.98; 95% CI = 1.12-3.50) and receptive anal sex (PR = 2.36; 95% CI = 0.95-5.86) were associated with the detection of Mycoplasma spp. No sociodemographic, clinical, or behavioural variable was significantly associated with the detection of Ureaplasma spp.

CONCLUSIONS

A high prevalence of Mollicutes was observed among adolescent MSM and TGW, especially at extragenital sites. Further research is required to understand the epidemiological profile of high-risk adolescents in different regions and contexts, and to investigate the pathogenesis of Mollicutes in the oral and anal mucosa before routine screening can be recommended in clinical practice.

Mycoplasma genitalium antibiotic resistance-associated mutations in genital and extragenital samples from men-who-have-sex-with-men attending a STI clinic in Verona, Italy

Background

Mycoplasma genitalium (MG) is one of the most warning emerging sexually transmitted pathogens also due to its ability in developing resistance to antibiotics. MG causes different conditions ranging from asymptomatic infections to acute mucous inflammation. Resistance-guided therapy has demonstrated the best cure rates and macrolide resistance testing is recommended in many international guidelines. However, diagnostic and resistance testing can only be based on molecular methods, and the gap between genotypic resistance and microbiological clearance has not been fully evaluated yet. This study aims at finding mutations associated with MG antibiotic resistance and investigating the relationship with microbiological clearance amongst MSM.

Methods

From 2017 to 2021, genital (urine) and extragenital (pharyngeal and anorectal swabs) biological specimens were provided by men-who-have-sex-with-men (MSM) attending the STI clinic of the Infectious Disease Unit at the Verona University Hospital, Verona, Italy. A total of 1040 MSM were evaluated and 107 samples from 96 subjects resulted positive for MG. Among the MG-positive samples, all those available for further analysis (n=47) were considered for detection of mutations known to be associated with macrolide and quinolone resistance. 23S rRNA, gyrA and parC genes were analyzed by Sanger sequencing and Allplex™ MG and AziR Assay (Seegene).

Results

A total of 96/1040 (9.2%) subjects tested positive for MG in at least one anatomical site. MG was detected in 107 specimens: 33 urine samples, 72 rectal swabs and 2 pharyngeal swabs. Among them, 47 samples from 42 MSM were available for investigating the presence of mutations associated with macrolide and quinolone resistance: 30/47 (63.8%) showed mutations in 23S rRNA while 10/47 (21.3%) in parC or gyrA genes. All patients with positive Test of Cure (ToC) after first-line treatment with azithromycin (n=15) were infected with 23S rRNA-mutated MG strains. All patients undergoing second-line moxifloxacin treatment (n=13) resulted negative at ToC, even those carrying MG strains with mutations in parC gene (n=6).

Conclusion

Our observations confirm that mutations in 23S rRNA gene are associated with azithromycin treatment failure and that mutations in parC gene alone are not always associated with phenotypic resistance to moxifloxacin. This reinforces the importance of macrolide resistance testing to guide the treatment and reduce antibiotic pressure on MG strains.

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.

Genetic Determinants of Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium and Their Prevalence in Moscow, Russia

Macrolide (MLR) and fluoroquinolone (FQR) resistance in Mycoplasma genitalium (MG) has recently become a major problem worldwide. The available data on the prevalence of MLR and FQR in MG in Russia are limited. In this study, we aimed to evaluate the prevalence and pattern of mutations in 213 MG-positive urogenital swabs from patients in Moscow between March 2021 and March 2022. MLR- and FQR-associated mutations were searched in 23S rRNA as well as in the parC and gyrA genes using Sanger sequencing. The prevalence of MLR was 55/213 (26%), with A2059G and A2058G substitutions being the two most common variants (36/55, 65%, and 19/55, 35%, respectively). FQR detection showed 17% (37/213); two major variants were D84N (20/37, 54%) and S80I (12/37, 32.4%) and three minor variants were S80N (3/37, 8.1%), D84G (1/37, 2.7%), and D84Y (1/37, 2.7%). Fifteen of the fifty-five MLR cases (27%) simultaneously harbored FQR. This study revealed the high frequency of MLR and FQR. We conclude that the improvement of patient examination algorithms and therapeutic approaches should be combined with the routine monitoring of antibiotic resistance based on the sensitivity profiles presented. Such a complex approach will be essential for restraining the development of treatment resistance in MG.

Prevalence of Mycoplasma genitalium infection with antimicrobial resistance mutations among gay sex workers in China

BACKGROUND

Gay sex workers (GSWs) within the population of men who have sex with men in China are known as money boys (MBs). Limited research has been conducted to investigate the infection rate and antimicrobial resistance of Mycoplasma genitalium (M. genitalium) among GSWs in China. This study aimed to evaluate the status of M. genitalium infection among in GSWs.

METHODS

This study was performed among 349 GSWs who were followed up for four years by internet-based sampling collection. The participants were asked to complete an online questionnaire using a mobile app, and trained interviewers took urethral, anorectal, and saliva swab specimens. STIs, including HIV and M. genitalium, were detected. Detection of resistance-associated mutations (RAMs) to macrolides and fluoroquinolones was performed via Sanger sequencing of the 23S rRNA, parC and gyrA genes.

RESULTS

GSWs were enrolled by identifying 10 initial "seeds" from the Blued and WeChat apps. Face-to-face interviews were conducted with 349 GSWs from June 2017 to July 2021. The prevalence of M. genitalium and HIV positivity was 92/349 (26.4%, 95% confidence interval [CI] 21.7-31.0) and 71/349 (20.3%, 95% CI 16.3-24.4), respectively. The proportion of GSWs with M. genitalium infection alone in urethral swabs was 16, and the proportion with symptoms was 2/16 (12.5%). The proportion of GSWs with M. genitalium infection alone in anorectal swabs was 36, and the proportion with symptoms was 3/36 (8.3%). Multivariate regression analysis showed that using new types of drugs in the past 3 months and inconsistent condom usage with clients in the past 30 days were associated with M. genitalium infection. Macrolide resistance within the 23S rRNA gene was detected in 73/88 (83.0%) of the M. genitalium-positive GSWs. Moreover, 79.8% (71/89) of parC and 21.1% (19/90) of gyrA genes had mutations responsible for fluoroquinolone resistance. Three cases had no mutations in any of the three genes, 11 cases had mutations in all three genes, five cases had gyrA and parC gene mutations with no mutation in the 23S rRNA gene, and 42 cases had 23S rRNA and parC gene mutations with no mutation in the gyrA gene.

CONCLUSION

M. genitalium infections in our study displayed a high prevalence and very high levels of macrolide and fluoroquinolone resistance among GSWs in China. Asymptomatic M. genitalium infections are quite common among GSWs. Routine resistance testing of M. genitalium-positive specimens and antimicrobial resistance surveillance are crucial.

Development of a Real-Time PCR Assay for Detection of Macrolide Resistance Mutations in Mycoplasma genitalium and Its Application for Epidemiological Surveillance in Russia

A real-time PCR assay based on probe fluorescence quenching by a primer was developed and validated for detection of macrolide resistance (MR)-associated mutations in the 23S rRNA gene of Mycoplasma genitalium. The assay involves identification of any nucleotide substitutions at positions 2058, 2059, and 2611 of 23S rRNA (Escherichia coli numbering) by the probe-based melting curve analysis immediately after amplification and was capable of detecting target mutations in clinical specimens and spiked samples with 92% sensitivity and 100% specificity. We applied this new assay to assess the prevalence of MR-associated mutations in 949 nonduplicate urogenital samples positive for M. genitalium by routine diagnostic PCR, which were collected from symptomatic patients in five cities in the European part of Russia during the period 2009-2019. Forty-three (4.92%) samples revealed the presence of MR mutations, and no trend toward an increase in resistance prevalence was observed over the 10-year period of the study. The most commonly detected mutations were A2058G (26/43; 60.47%) and A2059G (13/43; 30.23%), while other mutations were rare: A2058T (3/43; 6.98%) and C2611T (1/43; 2.33%). The data obtained underline the need for regular epidemiological monitoring to ensure effective patient management, rational use of antibiotics, and prevention of further spread of resistance.

Emerging multidrug resistance contributes to treatment failure in Mycoplasma genitalium infected patients in China

The increased treatment failure in patients with sexually transmitted Mycoplasma genitalium infection is associated with antimicrobial resistance. We performed a retrospective survey of antimicrobial clinical outcomes in M. genitalium-infected patients. In addition, we detected macrolide, fluoroquinolone and tetracycline resistance-associated markers to determine their role in treatment failure. The overall incidence of treatment failure was 28.29%, regardless of the drug used. In the present study, the prevalence of macrolide resistance-associated mutations in the 23S rRNA gene was 64%; that of fluroquinolone resistance-associated S83/D87 substitutions in the parC gene was 67.5%; and that of the tetracycline resistance-associated C1192T mutation in the 16S rRNA gene was 22.5%. Furthermore, evidence of dual antimicrobial resistance was found in 46.4% of pretreatment samples, and triple antimicrobial resistance was identified in 9.9%. These findings regarding the emergence of multidrug-resistant strains of M. genitalium in China are concerning and emphasize the importance of guiding M. genitalium treatment with antimicrobial resistance assays.

Potential therapeutic targets for combating Mycoplasma genitalium

Mycoplasma genitalium (M. genitalium) has emerged as a sexually transmitted infection (STI) all over the world in the last three decades. It has been identified as a cause of male urethritis, and there is now evidence that it also causes cervicitis and pelvic inflammatory disease in women. However, the precise role of M. genitalium in diseases such as pelvic inflammatory disease, and infertility is unknown, and more research is required. It is a slow-growing organism, and with the advent of the nucleic acid amplification test (NAAT), more studies are being conducted and knowledge about the pathogenicity of this organism is being elucidated. The accumulation of data has improved our understanding of the pathogen and its role in disease transmission. Despite the widespread use of single-dose azithromycin in the sexual health field, M. genitalium is known to rapidly develop antibiotic resistance. As a result, the media frequently refer to this pathogen as the "new STI superbug." Despite their rarity, antibiotics available today have serious side effects. As the cure rates for first-line antimicrobials have decreased, it is now a challenge to determine the effective antimicrobial therapy. In this review, we summarise recent M. genitalium research and investigate potential therapeutic targets for combating this pathogen.

Pathogenicity and virulence of Mycoplasma genitalium: Unraveling Ariadne's Thread

Mycoplasma genitalium, a pathogen from class Mollicutes, has been linked to sexually transmitted diseases and sparked widespread concern. To adapt to its environment, M. genitalium has evolved specific adhesins and motility mechanisms that allow it to adhere to and invade various eukaryotic cells, thereby causing severe damage to the cells. Even though traditional exotoxins have not been identified, secreted nucleases or membrane lipoproteins have been shown to cause cell death and inflammatory injury in M. genitalium infection. However, as both innate and adaptive immune responses are important for controlling infection, the immune responses that develop upon infection do not necessarily eliminate the organism completely. Antigenic variation, detoxifying enzymes, immunoglobulins, neutrophil extracellular trap-degrading enzymes, cell invasion, and biofilm formation are important factors that help the pathogen overcome the host defence and cause chronic infections in susceptible individuals. Furthermore, M. genitalium can increase the susceptibility to several sexually transmitted pathogens, which significantly complicates the persistence and chronicity of M. genitalium infection. This review aimed to discuss the virulence factors of M. genitalium to shed light on its complex pathogenicity and pathogenesis of the infection.

Low prevalence of macrolide resistance in Mycoplasma genitalium infections in a cohort of pregnant women living with human immunodeficiency virus

OBJECTIVE

Macrolide resistance in Mycoplasma genitalium (M. genitalium) is increasing as a result of the widespread use of azithromycin in the treatment of sexually transmitted infections (STIs). To date, there are few published studies on macrolide resistance patterns in South African pregnant women. This study now contributes to the growing body of knowledge.

METHODS

This study included 385 pregnant women living with HIV. Vaginal swabs were collected from consenting pregnant women and used for the detection of M. genitalium using the TaqMan assay. Macrolide resistance-associated mutations in the 23S rRNA gene were determined for all samples that tested positive for M. genitalium using the Allplex^TM MG & AziR assay (Seegene) which allows for the simultaneous detection and identification of M. genitalium and six mutations (A2058C, A2058G, A2058T, A2059C, A2059G and A2059T) responsible for azithromycin resistance. The correlation between the TaqMan assay and Allplex^TM MG & AziR assay (Seegene) for the detection of M. genitalium was also performed in a subset of 121 samples.

RESULTS

Of the 385 samples tested in this study, 14 samples were positive for M. genitalium estimating a prevalence of 3.6%. The same 14 samples also tested positive on the Allplex^TM assay indicating a good correlation between the TaqMan Assay and the Allplex^TM. Of the 14 positive samples, one sample carried a mutation at position A2059G denoting macrolide resistance in this pathogen. Mutations in the other regions of the 23S rRNA were not detected. All assay controls used in the mutation scanning produced the desired results showing the validity of the assay.

CONCLUSION

In this study, macrolide resistance in M. genitalium was detected. Despite the low prevalence of resistance determinants ongoing antimicrobial resistance surveillance is vital considering that azithromycin is used in the syndromic management for the treatment of vaginal discharge syndrome.

Mycoplasma genitalium: To treat or not to treat?

ABSTRACT

Many APRNs are not familiar with Mycoplasma genitalium, even if it is included on a sexually transmitted infection screening panel. This article briefly outlines prevalence, asymptomatic infection, clinical manifestations, diagnostics, and treatment.

Effect of Autolyzed Yarrowia lipolytica on the Growth Performance, Antioxidant Capacity, Intestinal Histology, Microbiota, and Transcriptome Profile of Juvenile Largemouth Bass (Micropterus salmoides)

The improper components of formulated feed can cause the intestinal dysbiosis of juvenile largemouth bass and further affect fish health. A 28 day feeding trial was conducted to investigate the effect of partially replacing fish meal (FM) with autolyzed Yarrowia lipolytica (YL) on juvenile largemouth bass (Micropterus salmoides). We considered four diets—control, YL25, YL50, and YL75—in which 0%, 25%, 50%, and 75% of the FM content, respectively, was replaced with YL. According to results, the weight gain rate (WGR) and specific growth rate (SGR) of the fish with the YL25 and YL50 diets were significantly higher than the WGR and SGR with the control diet, while the YL75 diet significantly reduced fish growth and antioxidant enzymes activities, and shortened the villus height in the intestinal mucosa. The 16S rRNA analysis of the intestinal microbiota showed that the relative abundance of Mycoplasma was significantly increased with the YL25 and YL50 diets, while the Enterobacteriacea content was increased with the YL75 diet. Moreover, our transcriptome analysis revealed that certain differentially expressed genes (DEGs) that are associated with growth, metabolism, and immunity were modulated by YL inclusion treatment. Dietary YL25 and YL50 significantly reduced the mRNA level of ERBB receptor feedback inhibitor 1 (errfi1) and dual-specificity phosphatases (dusp), while the expression of the suppressor of cytokine signaling 1 (socs1), the transporter associated with antigen processing 2 subunit type a (tap2a), and the major histocompatibility complex class I-related gene (MHC-I-l) were sharply increased with YL75 treatment. We determined that the optimum dose of dietary YL required for maximum growth without any adverse influence on intestinal health was 189.82 g/kg (with 31.63% of the fishmeal replaced by YL), while an excessive substitution of YL for fishmeal led to suppressed growth and antioxidant capacity, as well as intestinal damage for juvenile largemouth bass.

Sexually transmitted pathogens causing urethritis: A mini-review and proposal of a clinically based diagnostic and therapeutic algorithm

The purpose of this mini-review was to provide the latest information and concepts on diagnosis and treatment of the most common sexually transmitted pathogens causing urethritis. The incidence of several sexually transmitted infections that cause urethritis is increasing, and this genitourinary syndrome is among the most common reason young men see clinical care. The authors performed a literature search including the currently valid guidelines, and an overview of the most relevant pathogens is given. Moreover, the authors developed a clinically applicable diagnostic and therapeutic algorithm, because early diagnosis and correct treatment can sometimes prevent infected individuals from significant morbidity. Future research will focus on new methods to combat pathogens that cause urethritis, including vaccination.

Molecular Typing Reveals Distinct Mycoplasma genitalium Transmission Networks among a Cohort of Men Who Have Sex with Men and a Cohort of Women in France

Mycoplasma genitalium causes sexually transmitted infecti.ons in men and women. Treatment failures to macrolides and fluoroquinolones have been reported worldwide. Although the mgpB typing method has often been used in M. genitalium-infected men who have sex with men (MSM), limited typing data are available for M. genitalium-infected women. In this study, we aimed to investigate the genetic relationship between M. genitalium strains and their antibiotic resistance profile in a cohort of MSM (86.2% on HIV preexposure prophylaxis [PrEP], 13.8% HIV positive) and a large cohort of women using mgpB/MG309 typing. The mgpB types were determined in 374 samples from 305 women and 65 MSM. Three MSM and one woman had two concurrent or subsequent samples. Macrolide and fluoroquinolone resistance-associated mutations were searched in the 23S rRNA as well as parC and gyrA genes. The mgpB phylogenetic construction revealed three large clusters that differed according to sexual practices and geographical origin of patients. The prevalence of macrolide and fluoroquinolone resistance was significantly higher in MSM compared with women (95.4% vs. 14.1% and 30.6% vs. 7.2%, p < 0.001, respectively). The macrolide resistance spread was polyclonal in both populations, but clonal diffusion of two dual-resistant types was observed in PrEP users in association with high antibiotic pressure and dense connectivity in this population.

Summary of the Fourth Annual American Sexually Transmitted Diseases Association Workshop on Improving Sexually Transmitted Infection Control Efforts Through Cross-Sector Collaboration

ABSTRACT

The American Sexually Transmitted Diseases Association has, for several years, been conducting a cross-sector workshop to bring together a variety of stakeholders to develop ideas for collaboratively improving the sexually transmitted infection control efforts in the United States. In this summary, we share the content of discussions and ideas of the fourth annual workshop for future research and potential changes to practice with a focus on diagnostic capacity.

Mycoplasma genitalium and Chlamydia trachomatis infection among women in Southwest China: a retrospective study

Mycoplasma genitalium (MG) and Chlamydia trachomatis (CT) are the most common sexually transmitted pathogens, which can cause cervicitis, pelvic inflammation and infertility in female. In the present study, we collected the basic information, clinical results of leucorrhoea and human papillomavirus (HPV) infection of patients, who were involved in both MG and CT RNA detection in West China Second Hospital of Sichuan University from January 2019 to April 2021, ranging from 18 to 50 years old. The results showed that the infection frequencies of MG and CT were 2.6% and 6.5%, respectively. The infection rate of CT in gynaecological patients was significantly higher than that of MG (P < 0.001). Moreover, patients with CT infection often had symptoms of gynaecological diseases, while patients with MG infection remain often asymptomatic. By exploring the connection between MG or CT infection and vaginal secretions, we found that the infection of MG or CT promoted to the increase of vaginal leukocytes, and CT infection exacerbated the decrease of the number of Lactobacillus in the vagina. Further analysis suggested that independent infection and co-infection of MG or CT resulted in abnormal vaginal secretion, affecting the stability of vaginal environment, which may induce vaginal diseases. Unexpectedly, our study found no association between MG or CT infection and high-risk HPV infection. In conclusion, our study explored the infection of MG and CT among women in Southwest China for the first time, and revealed that the infection of MG or CT would affect the homeostasis of vaginal environment, which laid a foundation for the clinical diagnosis and treatment of MG and CT infection.

Molecular Tools for Typing Mycoplasma pneumoniae and Mycoplasma genitalium

Mycoplasma pneumoniae and Mycoplasma genitalium are cell wall-less bacteria with strongly reduced genome content and close phylogenetic relatedness. In humans, the only known natural host, the microorganisms colonize the respiratory or genitourinary mucosa and may cause a broad range of clinical presentations. Besides fundamental differences in their tissue specificity, transmission route, and ability to cause prevalence peaks, both species share similarities such as the occurrence of asymptomatic carriers, preferred populations for infection, and problems with high rates of antimicrobial resistance. To further understand the epidemiology of these practically challenging bacteria, typing of strains is necessary. Since the cultivation of both pathogens is difficult and not performed outside of specialized laboratories, molecular typing methods with adequate discriminatory power, stability, and reproducibility have been developed. These include the characterization of genes containing repetitive sequences, of variable genome regions without the presence of repetitive sequences, determination of single and multi-locus variable-number tandem repeats, and detection of single nucleotide polymorphisms in different genes, respectively. The current repertoire of procedures allows reliable differentiation of strains circulating in different populations and in different time periods as well as comparison of strains occurring subsequently in individual patients. In this review, the methods for typing M. pneumoniae and M. genitalium, including the results of their application in different studies, are summarized and current knowledge regarding the association of typing data with the clinical characteristics of infections is presented.

Sexual transmission of infections across Europe: appraising the present, scoping the future

Objectives: Our journal partnered with the Europe section of the International Union against STI (IUSTI) at a workshop held at the 18th European AIDS Conference in London on 30 October 2021. The workshop reviewed epidemiological trends and discussed STI care provision within HIV services across Europe. Methods and Results: We started by highlighting trends in bacterial STIs reported to the European Centre for Disease Prevention and Control from countries in the European Union/European Economic Area. This showed that notifications of bacterial STIs reached an all-time high in 2019, but are expected to be impacted by the COVID-19 pandemic in 2020-2021. We then reviewed the evolving relationship between STIs and HIV and pointed out how antiretroviral treatment and pre-exposure prophylaxis remain highly effective against HIV transmission despite the rising incidence of STIs. Within emerging concepts in STIs, we appraised the benefits and risks of asymptomatic screening for chlamydia, and also considered the potential perils of routinely testing for agents that lack a defined role in disease. Finally, we discussed standards of STI care for people living with HIV, informed by a brief survey of IUSTI Europe country representatives and members of the Euroguidelines in Central and Eastern Europe network. Conclusions: The survey indicated substantial variability and identified key improvement targets: fighting barriers to effective service provision and access, increasing diagnostic capability and taking leadership in driving up the quality of care. We must not forget the STI-related needs of the many people who will be living with HIV for decades into the future.

Mycoplasma genitalium: A new superbug

Mycoplasma genitalium (MG) is an emerging sexually transmitted pathogen. It is an important cause of nongonococcal urethritis in men and is associated with cervicitis and pelvic inflammatory disease in women, putting them at risk of infertility. Multiple factors that aid pathogenesis of MG include its ability of adhesion, gliding motility, and intracellular invasion by means of the tip organelle. Through intracellular localization and antigenic variation, MG could result in treatment-resistant chronic infection. There are limited data on the prevalence of MG in Indian patients with urogenital syndromes. Recently, a high prevalence of extra genital infection with MG has been reported. Molecular assays are the major diagnostic techniques of MG infection. Antimicrobial agents such as macrolides, along with fluoroquinolones, are the treatment of choice for MG infections. The issue of drug resistance to azithromycin and fluoroquinolones in MG is rising globally. As molecular tests are becoming available for MG, both for the diagnosis and the detection of antimicrobial resistance, any patient with MG infection should then be tested for antimicrobial resistance. Consideration of MG as a cause of sexually transmitted disease in the Indian population is crucial in diagnostic algorithms and treatment strategies. The purpose of this review is to understand the prevalence of MG in different clinical scenarios, molecular mechanisms of pathogenesis, current status of antimicrobial resistance, and its impact on MG treatment.

Evaluation of treatment with two weeks of doxycycline on macrolide-resistant strains of Mycoplasma genitalium: a retrospective observational study

BACKGROUND

Increasing macrolide resistance makes treatment of Mycoplasma genitalium infections challenging. The second-line treatment is moxifloxacin, an antibiotic drug best avoided due to the potential of severe side effects and interactions. This study evaluates the effects of treatment with doxycycline 100 mg twice daily for 2 weeks as an alternative to moxifloxacin.

METHODS

This retrospective observational study examined the medical records of patients testing positive for macrolide resistant Mycoplasma genitalium from January 1st, 2016 to September 1st, 2019 in Trondheim, Norway. Information regarding symptoms as well as clinical and microbiological cure was collected.

RESULTS

263 infections from 259 patients (161 females/98 males) were examined. 155 (58.9%) had a negative test of cure following treatment. 34.7% of symptomatic patients not achieving microbiological cure experienced symptom relief or clearance. There was no statistical difference between bacterial loads in symptomatic versus asymptomatic patients. The mean difference was 1.6 × 105 copies/ml (95% CI - 1.4 × 105-4.8 × 105, p = 0.30) for women and 1.4 × 106 copies/ml (95% CI -4.0 × 105-3.2 × 106, p = 0.12) for men.

CONCLUSIONS

The cure rate of doxycycline in this study is higher than previously reported. This adds support to doxycycline's role in treatment before initiating treatment with less favorable drugs such as moxifloxacin.

Novel strategies for prevention and treatment of antimicrobial resistance in sexually-transmitted infections

PURPOSE OF REVIEW

Antimicrobial resistance in sexually acquired infection (STI) pathogens is an important global public health threat. There is an urgent need for novel STI treatment and prevention strategies to tackle the rising incidence of STIs in high-income settings and the static progress in low- and middle-income settings over the past decade. The purpose of this review was to describe the research outlining the emergence of resistance in common STI pathogens and new strategies for their treatment and prevention.

RECENT FINDINGS

Rates of STIs have dramatically increased over the past decade. Further, antimicrobial resistance to first-line agents among key STI pathogens continues to emerge globally. Recent findings demonstrate promising results regarding the efficacy of novel antimicrobial treatment strategies for these pathogens, including several new, repurposed and unique combinations of antimicrobials. In addition, a number of new biomedical prevention strategies, such as antibacterial mouthwash and doxycycline chemoprophylaxis, are being investigated as novel prevention strategies for bacterial STIs.

SUMMARY

Significant progress has been made in the development of novel antimicrobials for the treatment of antimicrobial-resistant sexually acquired pathogens. However, due to the rapid development of resistance to antimicrobials demonstrated by these pathogens in the past, further research and development of effective prevention strategies should be prioritized.

Dietary sodium butyrate supplementation attenuates intestinal inflammatory response and improves gut microbiota composition in largemouth bass (Micropterus salmoides) fed with a high soybean meal diet

The study aimed to investigate the effects of dietary sodium butyrate (NaBT) supplementation on the gut health of largemouth bass (Micropterus salmoides) fed with a high soybean meal diet. Three isonitrogenous and isolipidic diets were formulated: a high fishmeal group (Control); a high soybean meal group (SBM), in which the 30% fishmeal protein in the Control diet was replaced by soy protein; and an NaBT group, in which 0.2% NaBT was added to the SBM diet. Each diet was fed to triplicate tanks (20 fish in each tank). After 8 weeks of feeding trial, the distal intestine and intestinal digesta of the fish in each treatment were sampled. The results showed that fishmeal replacement and NaBT supplementation did not affect fish growth performance. Dietary 0.2% NaBT supplementation improved intestinal morphology, increasing the villus width and villus height and reducing the width of lamina propria. The distal intestine of fish in the control and NaBT groups demonstrated lower activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) and a lower malondialdehyde (MDA) content, compared with the fish in the SBM group. Moreover, the addition of 0.2% NaBT in the feed significantly decreased the expression of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) compared to the SBM diet. PCoA and UPGMA analyses based on weighted UniFrac distances demonstrated that intestinal microbial communities in the NaBT group were closer to those in the control group than to those in the SBM group. In addition, dietary 0.2% NaBT supplementation significantly increased the abundance of Firmicutes and Bacteroidetes and decreased the abundance of Tenericutes at the phylum level. Furthermore, the abundance of Bacteroides, Lachnospiraceae_unclassified, and Lachnospiraceae_uncultured was significantly increased, while that of Mycoplasma was significantly decreased in fish intestine at NaBT group at the genus level. In conclusion, dietary NaBT supplementation had beneficial roles in protecting the gut health of largemouth bass from the impairments caused by soybean meal.

Determination of In Vitro Antimicrobial Susceptibility for Lefamulin (Pleuromutilin) for Ureaplasma Spp. and Mycoplasma hominis

Lefamulin is the first of the pleuromutilin class of antimicrobials to be available for therapeutic use in humans. Minimum inhibitory concentrations of lefamulin were determined by microbroth dilution for 90 characterised clinical isolates (25 Ureaplasma parvum, 25 Ureaplasma urealyticum, and 40 Mycoplasma hominis). All Mycoplasma hominis isolates possessed lefamulin MICs of ≤0.25 mg/L after 48 h (MIC_50/90 of 0.06/0.12 mg/L), despite an inherent resistance to macrolides; while Ureaplasma isolates had MICs of ≤2 mg/L after 24 h (MIC_50/90 of 0.25/1 mg/L), despite inherent resistance to clindamycin. Two U. urealyticum isolates with additional A2058G mutations of 23S rRNA, and one U. parvum isolate with a R66Q67 deletion (all of which had a combined resistance to macrolides and clindamycin) only showed a 2-fold increase in lefamulin MIC (1–2 mg/L) relative to macrolide-susceptible strains. Lefamulin could be an effective alternative antimicrobial for treating Ureaplasma spp. and Mycoplasma hominis infections irrespective of intrinsic or acquired resistance to macrolides, lincosamides, and ketolides. Based on this potent in vitro activity and the known good, rapid, and homogenous tissue penetration of female and male urogenital tissues and glands, further exploration of clinical efficacy of lefamulin for the treatment of Mycoplasma and Ureaplasma urogenital infections is warranted.

Mycoplasma genitalium prevalence and macrolide resistance-associated mutations and coinfection with Chlamydia trachomatis in Southern Jutland, Denmark

This study aims to investigate prevalence of Mycoplasma genitalium and macrolide resistance‐associated mutations and coinfection with other sexually transmitted bacteria in Southern Jutland, Denmark, where this information is very limited. Urinary samples from patients suspected of sexually transmitted bacterial infections collected at primary healthcare facilities in Southern Jutland are routinely tested for Chlamydia trachomatis and Neisseria gonorrhoeae. 601 of these samples were analysed with SpeeDx MG+23S reagents, which can detect M. genitalium and macrolide resistance‐mediating mutations in the 23S rRNA gene. Moreover, 147 C. trachomatis positive urinary samples from routine test were also analysed with the PCR assay to detect M. genitalium. 72 out of 601 samples were detected positive for C. trachomatis (12%), five samples (0.83%) positive for N. gonorrhoeae and 25 samples positive for M. genitalium (4.2%). 14 of the 25 M. genitalium samples were detected having 23S rRNA gene mutations associated with macrolide resistance (56%). 25 of 147 C. trachomatis positive samples were tested positive for M. genitalium (17%) and two of them were positive for M. genitalium and N. gonorrhoeae (1.4%). The high prevalence of M. genitalium and macrolide resistance‐associated mutation and the coinfection with C. trachomatis in the region suggesting that M. genitalium testing should be included in routine sexually transmitted infection screening.

Clinical, epidemiological and therapeutic characteristics of Mycoplasma genitalium infection in a French STI center

OBJECTIVES

We report the characteristics of Mycoplasmagenitalium (MG) infection in patients from a STI center in Paris. We evaluated outcomes after treatment.

METHODS

We included all patients tested for MG, Chlamydiatrachomatis (CT) and Neisseria gonorrhoeae (NG) infection in our center from January 2017 to December 2018, using multiplex PCR on urine specimen, vaginal or rectal swabs. We collected data regarding sex, age, HIV status, PrEP use, sexual behavior, NG and CT co-infection, symptoms and treatment.

RESULTS

MG infection prevalence was 7% (397/5586) (95% CI 6.4-7.8). It ranged from 4.6% in patients consulting for routine STI testing (3.9% in women, 5% in men), to 16% in HIV-positive patients and 25% in PrEP users. Among the 397 MG infected patients, 351 (88%) were asymptomatic and 87 (22%) were co-infected with NG or CT. Among the 270 (68%) treated patients, 249 (92%) received azithromycin. Failure rate was 74% in the 103 patients tested post-treatment. Treatment failure tended to be higher with azithromycin single dose than with 5-day azithromycin (88% vs. 70%; P=0.07). Azithromycin and moxifloxacin were used as second-line treatment in 24 and 23 patients, respectively. Post-treatment PCR remained positive in 55% of the 44 tested patients with a better eradication rate with moxifloxacin than with azithromycin (70% vs. 33%; P=0.04).

CONCLUSION

MG infection is highly prevalent in PrEP users and HIV-positive patients and is mostly asymptomatic. Management of MG infection should be tailored and adapted to the risk of antibiotic resistance and reinfection.

Pelvic inflammatory disease in the adolescent and young adult: An update

Pelvic inflammatory disease (PID) is an infection of the female upper genital tract that is typically polymicrobial with classic core involvement of Neisseria gonorrhoeae and/or Chlamydia trachomatis, though other endogenous flora from the vagino-cervical areas can be involved as well. It is often a sexually transmitted disease but other etiologic routes are also noted. A variety of risk factors have been identified including adolescence, young adulthood, adolescent cervical ectropion, multiple sexual partners, immature immune system, history of previous PID, risky contraceptive practices and others. An early diagnosis and prompt treatment are necessary to reduce risks of PID complications such as chronic pelvic pain, ectopic pregnancy and infertility. Current management principles of PID are also reviewed. It is important for clinicians to screen sexually active females for common sexually transmitted infections such as Chlamydia trachomatis and provide safer sex education to their adolescent and young adult patients. Clinicians should provide comprehensive management to persons with PID and utilize established guidelines such as those from the US Centers for Disease Control and Prevention (CDC).

Antibiotic Resistance and Genotypes of Mycoplasma genitalium during a Resistance-Guided Treatment Regime in a German University Hospital

The treatment of infections from the sexually transmitted pathogen Mycoplasma genitalium is hampered by the rapidly increasing resistance to the recommended first- (macrolides) and second-line antibiotics (quinolones). Thus, resistance-guided therapy (RGT) is key for its successful eradication but the efficiency of this approach can be influenced by re-infections and treatment failures. The typing of strains is helpful to distinguish between ongoing colonization, re-infection or the development of resistance. In the present study, mgpB and MG_309 types as well as mutations associated with macrolide, quinolone and tetracycline resistance of strains in M. genitalium-positive samples accumulated in the years 2019 and 2020 at a university hospital were analyzed. Fifty-eight positive first and sixteen positive follow-up samples from patients (96.6% male, 84.5% men who have sex with men, 74.1% HIV-positive) were included. Twenty-three mgpB types (seven new types), nine MG_309 types and thirty-four mgpB/MG_309 types were identified. The prevalence of mutations associated with macrolide, quinolone and tetracycline resistance was 56.9%, 10.3% and 6.8%, respectively. Despite the fact that many asymptomatic patients were not treated and tests of cure were impossible in different cases, the preliminary rate of successful eradication (93.3%) in this study is promising for the continuation of the RGT strategy.

Molecular epidemiology and antimicrobials resistance mechanism of Mycoplasma genitlaium

Currently, infections caused by Mycoplasma genitalium are ones the most common sexually transmitted infections. Their prevalence is varied from 1.3% to 15.9%. Infections caused by M.genitalium may lead to urethritis in men and a wide spectrum of diseases in women. Antibiotic resistance now is one of the most emerging problems both in the scientific and in the healthcare fields. The usage of antimicrobials inhibiting cell wall synthesis for the treatment of M.genitalium is ineffective, and resistance to macrolides and fluoroquinolones is increasing rapidly. M.genitalium infections diagnostics is complicated due to specific conditions and duration of culture methods. The usage of nucleic acid amplification techniques is the most relevant for laboratory diagnostics, and is used in existing assays. This review compiles current data on the prevalence, molecular mechanisms of pathogenesis and antibiotic resistance, as well as diagnostics methods of M.genitalium.

[Clinical implications of the genus Mycoplasma]

Dentro del género Mycoplasma, las especies que tradicionalmente se han relacionado con cuadros infecciosos han sido principalmente M. pneumoniae, M. genitalium, M. hominis o U. urealyticum. Sin embargo, existen otras muchas que están implicadas y, que muchas veces, son desconocidas para los profesionales sanitarios. El objetivo de esta revisión es identificar todas las especies del género Mycoplasma que se han aislado en el hombre y determinar su participación en la patología infecciosa humana.

High Prevalence and High Rate of Antibiotic Resistance of Mycoplasma genitalium Infections in Men who Have Sex with Men. A Sub-Study of the ANRS Ipergay PrEP Trial

BACKGROUND

Mycoplasma genitalium (MG) is an emerging pathogen among men who have sex with men (MSM) with raising rates of antibiotic resistance. In this study, we assessed the prevalence and incidence of MG infection in MSM enrolled in the open-label phase of the ANRS IPERGAY trial with on demand TDF/FTC for HIV prevention and the impact of doxycycline post-exposure prophylaxis (PEP).

METHODS

210 subjects were tested at baseline and at 6 months by real-time PCR assays for MG detection in urine samples, oro-pharyngeal and anal swabs. Resistance to azithromycin (AZM), to fluoroquinolones (FQ) and to doxycycline were investigated in the French National Reference Centre of bacterial STI.

RESULTS

The all-site prevalence of MG at baseline was 10.5% [6.3% in urine samples, 4.3% in anal swabs and 0.5% in throat swabs] and remained unchanged at 6 months whether or not PEP was used: 9.9% overall, 10.2% with PEP and 9.6% without. The overall rate of MG resistance (prevalent and incident cases) to AZM and FQ was 67.6% and 9.1%, respectively, with no difference between arms. An in vivo mutation of the MG 16S rRNA which could be associated with tetracycline resistance was observed in 12.5% of specimens tested.

CONCLUSIONS

The prevalence of MG infection among MSM on PrEP was high and its incidence was not decreased by doxycycline prophylaxis with a similar high rate of AZM- and FQ-resistance, raising challenging issues for the treatment of this STI and supporting current recommendations to avoid testing or treatment of asymptomatic MG infection.

Mycoplasma genitalium Biofilms Contain Poly-GlcNAc and Contribute to Antibiotic Resistance

Mycoplasma genitalium is an important etiologic agent of non-gonococcal urethritis (NGU), known for chronicity and multidrug resistance, in which biofilms may play an integral role. In some bacterial species capable of forming biofilms, extracellular polymeric substances (EPS) composed of poly-N-acetylglucosamine (PNAG) are a crucial component of the matrix. Monosaccharide analysis of M. genitalium strains revealed high abundance of GlcNAc, suggesting a biofilm-specific EPS. Chromatograms also showed high concentrations of galactose and glucose as observed in other mycoplasma species. Fluorescence microscopy of M. genitalium biofilms utilizing fluor-coupled lectins revealed differential staining of biofilm structures. Scanning electron microscopy (SEM) showed increasing maturation over time of bacterial “towers” seen in biofilm development. As seen with Mycoplasma pneumoniae, organisms within fully mature M. genitalium biofilms exhibited loss of cell polarization. Bacteria associated with disrupted biofilms exhibited decreased dose-dependent viability after treatment with antibiotics compared to bacteria with intact biofilms. In addition, growth index analysis demonstrated decreases in metabolism in cultures with disrupted biofilms with antibiotic treatment. Taken together, these data suggest that M. genitalium biofilms are a contributing factor in antibiotic resistance.

Too Much of a Good Thing: How Ectopic DNA Replication Affects Bacterial Replication Dynamics

Each cell division requires the complete and accurate duplication of the entire genome. In bacteria, the duplication process of the often-circular chromosomes is initiated at a single origin per chromosome, resulting in two replication forks that traverse the chromosome in opposite directions. DNA synthesis is completed once the two forks fuse in a region diametrically opposite the origin. In some bacteria, such as Escherichia coli, the region where forks fuse forms a specialized termination area. Polar replication fork pause sites flanking this area can pause the progression of replication forks, thereby allowing forks to enter but not to leave. Transcription of all required genes has to take place simultaneously with genome duplication. As both of these genome trafficking processes share the same template, conflicts are unavoidable. In this review, we focus on recent attempts to add additional origins into various ectopic chromosomal locations of the E. coli chromosome. As ectopic origins disturb the native replichore arrangements, the problems resulting from such perturbations can give important insights into how genome trafficking processes are coordinated and the problems that arise if this coordination is disturbed. The data from these studies highlight that head-on replication–transcription conflicts are indeed highly problematic and multiple repair pathways are required to restart replication forks arrested at obstacles. In addition, the existing data also demonstrate that the replication fork trap in E. coli imposes significant constraints to genome duplication if ectopic origins are active. We describe the current models of how replication fork fusion events can cause serious problems for genome duplication, as well as models of how such problems might be alleviated both by a number of repair pathways as well as the replication fork trap system. Considering the problems associated both with head-on replication-transcription conflicts as well as head-on replication fork fusion events might provide clues of how these genome trafficking issues have contributed to shape the distinct architecture of bacterial chromosomes.