Comparison of polymerase chain reaction assay with culture for detection of genital mycoplasmas in perinatal infections

Antimicrobial Activity of N,N-Diethyldithiocarbamate against Ureaplasma parvum and Ureaplasma urealyticum

Ureaplasma species (Ureaplasma spp.) are commonly found as commensals in the human urogenital tracts, although their overgrowth can lead to infection in the urogenital tract and at distal sites. Furthermore, ureaplasmas lack a cell wall and do not synthesize folic acid, which causes all β-lactam and glycopeptide antibiotics, and sulfonamides and diaminopyrimidines, to be of no value. The antibiotics used in therapy belong to the fluoroquinolone, tetracycline, chloramphenicol and macrolide classes. However, the growing incidence of antibiotic-resistant Ureaplasma spp. in the population becomes a problem. Thus, there is a need to search for new drugs effective against these bacteria. Since 1951, the FDA-approved, well-tolerated, inexpensive, orally administered drug disulfiram (DSF) has been used in the treatment of chronic alcoholism, but recently, its antimicrobial effects have been demonstrated. The main biological metabolite of DSF, i.e., N,N-diethyldithiocarbamate (DDC), is generally believed to be responsible for most of the observed pharmacological effects of DSF. In the presented studies, the effect of DDC at concentrations of 2 µg/mL, 20 µg/mL and 200 µg/mL on the growth and survival of Ureaplasma urealyticum and Ureaplasma parvum was tested for the first time. The results indicated that all the used DDC concentrations showed both bacteriostatic and bactericidal activity against both tested strains.

Weighing Potential Benefits and Harms of Mycoplasma genitalium Testing and Treatment Approaches

This systematic review demonstrates increasing antimicrobial resistance and incomplete understanding of the bacterium’s natural history.

Since Mycoplasma genitalium was identified 40 years ago, much of the epidemiology has been described, diagnostic tests have been developed and approved, and recommended treatment approaches have been identified. However, the natural history remains incompletely understood, and antimicrobial resistance has rapidly increased. This review summarizes evidence published since the US Centers for Disease Control and Prevention 2015 Sexually Transmitted Diseases Treatment Guidelines. Data on sequelae remain insufficient, macrolide resistance is common, and fluoroquinolone resistance is increasing. Potential benefits of testing and treatment include resolving symptoms, interrupting transmission, and preventing sequelae. Potential harms include cost, patient anxiety, and increasing antimicrobial resistance.

2021 European guideline on the management of Mycoplasma genitalium infections

Mycoplasma genitalium infection contributes to 10-35% of non-chlamydial non-gonococcal urethritis in men. In women, M. genitalium is associated with cervicitis and pelvic inflammatory disease (PID) in 10-25%. Transmission of M. genitalium occurs through direct mucosal contact.

CLINICAL FEATURES AND DIAGNOSTIC TESTS

Asymptomatic infections are frequent. In men, urethritis, dysuria and discharge predominate. In women, symptoms include vaginal discharge, dysuria or symptoms of PID - abdominal pain and dyspareunia. Symptoms are the main indication for diagnostic testing. Diagnosis is achievable only through nucleic acid amplification testing and must include investigation for macrolide resistance mutations.

THERAPY

Therapy for M .genitalium is indicated if M. genitalium is detected. Doxycycline has a cure rate of 30-40%, but resistance is not increasing. Azithromycin has a cure rate of 85-95% in macrolide-susceptible infections. An extended course of azithromycin appears to have a higher cure rate, and pre-treatment with doxycycline may decrease organism load and the risk of macrolide resistance selection. Moxifloxacin can be used as second-line therapy but resistance is increasing.

RECOMMENDED TREATMENT

Uncomplicated M. genitalium infection without macrolide resistance mutations or resistance testing: Azithromycin 500 mg on day one, then 250 mg on days 2-5 (oral). Second-line treatment and treatment for uncomplicated macrolide-resistant M. genitalium infection: Moxifloxacin 400 mg od for 7 days (oral). Third-line treatment for persistent M. genitalium infection after azithromycin and moxifloxacin: Doxycycline or minocycline 100 mg bid for 14 days (oral) may cure 40-70%. Pristinamycin 1 g qid for 10 days (oral) has a cure rate of around 75%. Complicated M. genitalium infection (PID, epididymitis): Moxifloxacin 400 mg od for 14 days. MAIN CHANGES FROM THE 2016 EUROPEAN M.

GENITALIUM GUIDELINE

Due to increasing antimicrobial resistance and warnings against moxifloxacin use, indications for testing and treatment have been narrowed to primarily involve symptomatic patients. The importance of macrolide resistance-guided therapy is emphasised.

Lipoic Acid Does Not Affect The Growth of Mycoplasma hominis Cells In Vitro

Mycoplasma hominis is associated with various infections, for which the treatment can be complex. Lipoic acid (LA) plays a role as a cofactor in eukaryotes, most Bacteria, and some Archea. Research of recent years has increasingly pointed to the therapeutic properties of exogenously supplemented LA. The present study was conducted on 40 strains of M. hominis cultured with the following LA concentrations: 1,200 μg/ml, 120 μg/ml, and 12 μg/ml. The bacterial colonies of each strain were counted and expressed as the number of colony-forming units/ml (CFU). The number of CFU in M. hominis strains obtained in the presence of LA was compared with the number of CFU in the strains grown in the media without LA. The obtained results indicated that the presence of LA in the medium did not affect the growth of M. hominis. The investigation of the influence of LA on the growth and survival of microbial cells not only allows for obtaining an answer to the question of whether LA has antimicrobial activity and, therefore, can be used as a drug supporting the treatment of patients infected with a given pathogenic microorganism. Such studies are also crucial for a better understanding of LA metabolism in the microbial cells, which is also important for the search for new antimicrobial drugs. This research is, therefore, an introduction to such further studies.

Distribution of Chlamydia trachomatis omp A genotypes in patients attending a sexually transmitted disease outpatient clinic in New Delhi, India

Background & objectives:

Limited data are available on the typing of Chlamydia trachomatis in India. Serovars D to K of C. trachomatis are chiefly responsible for urogenital infections. Thus, this study was conducted to determine the distribution of C. trachomatis serovars in patients with urogenital infections and to characterize ompA gene of the detected C. trachomatis isolates by sequence analysis. Presence of other co-infections was also evaluated.

Methods:

Endocervical swabs were collected from 324 women and urethral swabs/urine were collected from 193 men attending the sexually transmitted diseases outpatient clinic. The samples were screened for C. trachomatis by cryptic plasmid PCR and ompA gene PCR. Genotyping was performed by PCR-restriction fragment length polymorphism (RFLP) and sequencing of the ompA gene. Samples were screened for genital mycoplasmas, Neisseria gonorrhoeae, Treponema pallidum and human immunodeficiency virus (HIV).

Results:

C. trachomatis was found in 15.0 per cent men and 10.8 per cent women. Serovar D was the most prevalent followed by serovars E, F, I and G. Twenty two C. trachomatis isolates were selected for ompA gene sequencing. No mixed infection was found. Variability in ompA sequences was seen in 31.8 per cent cases. Both PCR-RFLP and ompA gene sequencing showed concordant results. The presence of Ureaplasma spp. and Mycoplasma hominis was observed in 18.7 and 9.5 per cent patients, respectively. Co-infection of C. trachomatis was significantly associated with Ureaplasma urealyticum and HIV.

Interpretation & conclusions:

The high occurence of C. trachomatis infections warrants its screening in addition to other sexually transmitted infections namely U. urealyticum and HIV. Genotyping of the ompA gene may provide additional information for vaccine development.

Vaginal Mycoplasmataceae colonization and association with immune mediators in pregnancy

OBJECTIVE

To determine the prevalence of Mycoplasmataceae species in pregnant women and evaluate their association with immune system mediators.

METHODS

Women were prospectively enrolled between 16-22 weeks' gestation. Vaginal swabs were self-collected and analyzed with PCR for Mycoplasma hominis (MH) and Mycoplasma genitalium (MG) as well as Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) (collectively, Myc). Immune mediators were measured via Luminex multiplex assay. Women with vaginal Mycoplasmataceae were compared to women without Myc, and women with Mycoplasma species (MH or MG) were compared to women without MH or MG. Linear regression models were used to investigate the relationship of the presence of Mycoplasmataceae on log-transformed immune mediators while controlling for confounders using propensity scores.

RESULTS

One-hundred-twenty women were enrolled and had complete lab data available. Colonization was 20.8, 2.5, 10.0, and 48.3% for MH, MG, UU, and UP, respectively. Women with any Mycoplasmataceae were more likely to be younger, of the Black race, and have public insurance. There were no significant differences in immune mediators between women with vaginal Mycoplasmataceae versus those without. After controlling for confounders, women with MH and/or MG had significantly elevated levels of IL-1β compared to women without MH or MG (estimate =  1.12; 95% CI =  0.33, 1.93). There were no other significant differences in immune mediators in women with MH and/or MG compared to those without.

CONCLUSIONS

Colonization rates were highest for UP and lowest for MG. Higher IL-1β levels were seen in the presence of MH and/or MG, indicating that these less frequently encountered organisms may incite a stronger host response. There were no other significant differences in immune mediator levels.

Mycoplasma genitalium infections: current treatment options and resistance issues

Mycoplasma genitalium is one of the important causes of non-gonococcal urethritis. Rising incidence and emerging antimicrobial resistance are a major concern these days. The poor clinical outcomes with doxycycline therapy led to the use of azithromycin as the primary drug of choice. Single-dose azithromycin regimen over a period of time was changed to extended regimen following studies showing better clinical cures and less risk of resistance development. However, emerging macrolide resistance, either due to transmission of resistance or drug pressure has further worsened the management of this infection. The issues of drug resistance and treatment failures also exist in cases of M. genitalium infection. At present, the emergence of multidrug-resistant (MDR) M. genitalium strains is an alarming sign for its treatment and the associated public health impact due to its complications. However, newer drugs like pristinamycin, solithromycin, sitafloxacin, and others have shown a hope for the clinical cure, but need further clinical trials to optimize the therapeutic dosing schedules and formulate appropriate treatment regimens. Rampant and inappropriate use of these newer drugs will further sabotage future attempts to manage MDR strains. There is currently a need to formulate diagnostic algorithms and etiology-based treatment regimens rather than the syndromic approach, preferably using combination therapy instead of a monotherapy. Awareness about the current guidelines and recommended treatment regimens among clinicians and local practitioners is of utmost importance. Antimicrobial resistance testing and global surveillance are required to assess the efficacy of current treatment regimens and for guiding future research for the early detection and management of MDR M. genitalium infections.

Mollicutes in vaginal microbiology: Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum and Mycoplasma genitalium

Mycoplasma hominis was isolated in 1937 from the human genital tract, followed 17 years later by Ureaplasma urealyticum and 27 years after that by Mycoplasma genitalium. The first two proved relatively easy to culture but the latter required a polymerase chain reaction assay for further studies. In sexually mature women, M. hominis may be found in the vagina/cervix of about 20-50%, ureaplasmas in 40-80% and M. genitalium in 0-5%. Some heterogeneity has been found among strains of all these species, sufficient to divide ureaplasmas into two species, namely U. urealyticum and Ureaplasma parvum. Studies in female mice show that sex hormones have a profound influence on colonization, multiplication and persistence of mycoplasmas/ureaplasmas in the genital tract and provoke the question, unanswered, of whether there is such an effect in the human tract. In women, there is no evidence that any of the mycoplasmal species stimulate an inflammatory vaginitis. M. hominis organisms increase hugely in number in the case of bacterial vaginosis (BV), and to a lesser extent so do ureaplasmas. Despite this, they have not been incriminated as a sole cause of BV. Evidence for the involvement of M. genitalium remains controversial. The strong association of BV with preterm birth raises the possibility that the genital mycoplasmas might play a part, but assurance that any do will be difficult to obtain. Detailed examination of the vaginal microbiome has not yet provided an answer.

Background review for the 2016 European guideline on Mycoplasma genitalium infections

Mycoplasma genitalium is a cause of 10-35% of non-chlamydial non-gonococcal urethritis in men and in women, and is associated with cervicitis and pelvic inflammatory disease (PID). Transmission of M. genitalium occurs through direct mucosal contact. In women, symptoms include vaginal discharge, dysuria or symptoms of PID - abdominal pain and dyspareunia. In men, urethritis, dysuria and discharge predominates. Asymptomatic infections are frequent. In this review, we present the evidence base for the recommendations in the 2016 European guideline on M. genitalium infections and describe indications for testing, recommended diagnostic methods, treatment and patient management. The guideline was prepared on behalf of the European branch of The International Union against Sexually Transmitted Infections; the European Academy of Dermatology and Venereology; the European Dermatology Forum; the European Society of Clinical Microbiology and Infectious Diseases; the Union of European Medical Specialists. The European Centre for Disease Prevention and Control and the European Office of the World Health Organisation also contributed to their development.

Isolation and molecular identification of Mycoplasma hominis in infertile female and male reproductive system

Background:

Infection of urogenital system with Mycoplasma potentially affect reproductive system and increases infants mortalities. Therefore, detection of these organisms is an important issue that should be considered and appropriate diagnostic methods should be used to identify these microorganisms. In the female reproductive system, infection can affect different parts of the cervix, endometrium, and fallopian tube. The extent of this infection in different diseases and its pathogenesis might be related to anatomic site of involvement. Some infections can lead to infertility in both males and females. Genital infection with Mycoplasmas have devastating effects on reproductive organs and cause fertility disorders and mortality in infants. In recent years, many studies have been conducted to isolate these pathogens; however, the isolates have not been identified so far.

Objectives:

The aim of this study was to determine the molecular identity of Mycoplasma hominis isolated from infertile female and male reproductive system in the Infertility Center of Kerman.

Materials and Methods:

This descriptive study was performed purposefully on 100 infertile females and 100 infertile males who were referred to the Infertility Center of Kerman during a six-month period. The collected samples of semen and vaginal swabs were examined for the presence of M. hominis by PCR. The samples with positive results in PCR were selected for molecular identification. Alignment of samples sequence was performed using MEGA 5 software through Neighbor-joining method.

Results:

Among 100 samples from infertile males, the presence of genus Mycoplasma was confirmed in 45 cases of which 15 cases were infected with M. hominis. Among 100 samples from infertile female, the presence of genus Mycoplasma was confirmed in 43 cases of which 18 case were infected with M. hominis. The positive samples were sequenced and the phylogenetic tree was plotted.

Conclusions:

The results showed that 37.5% of infertile males and females were infected with M. hominis. Analysis of the nucleotide sequences of the study isolates indicates a particular variety among these isolates. In comparing the isolates in the study, a very little genotypic similarity was found among some of them.

The role of Mycoplasma and Ureaplasma in adverse pregnancy outcomes

Genital mycoplasmas are frequently found in the vaginal flora across socioeconomic and ethnic groups and have been demonstrated to be involved in adverse perinatal outcomes. Both Mycoplasma and Ureaplasma spp cause inflammation potentially leading to spontaneous preterm birth and PPROM as well as postdelivery infectious complications and neonatal infections. Herein we have provided an overview of the existing literature and supportive evidence for genital mycoplasma's role in perinatal complications. Future research will need to focus on clearly delineating the species, allowing for discrimination of their effects.

Molecular investigation of menstrual tissue for the presence of Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis collected by women with a history of infertility

AIM

At present, routine laboratory investigation of the infectious agents implicated in female genital infections is mainly based on culture/direct fluorescence antibody (DFA) (immunofluorescence antibody test) results of cervicovaginal secretions. In this study the use of the menstrual tissue is introduced for the molecular detection of pathogens which are implicated in female infertility.

MATERIAL AND METHODS

Cervicovaginal secretions and menstrual tissue samples of 87 women (mean age 34.07 ± 5.17) experiencing infertility problems were screened for Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis presence using polymerase chain reaction (PCR, light cycler-PCR). Cervicovaginal secretions were also tested by the culture/DFA technique. The results were compared using the binomial test.

RESULTS

In the overall study group, the prevalence of C. trachomatis was 25.3%, 18.3%, and 13.8%, the prevalence of U. urealyticum was 18.3%, 16.09% and 12.6% and the prevalence of M. hominis was 13.7%, 19.5% and 8.0% in the menstrual tissue, cervicovaginal secretions using PCR and cervicovaginal secretions culture/DFA, respectively. A statistically significant difference was revealed between the two methods for all three microbes and between menstrual tissue and cervicovaginal secretions PCR for chlamydia.

CONCLUSIONS

The use of menstrual tissue along with the PCR method seems to be an effective and thus novel alternative for the investigation of the infectious agents lying in the genital tract. One of the main advantages of this technique compared to cervicovaginal secretions is that it is non-invasive and the sample can be collected at home, thus allowing the early detection and treatment of a condition that can otherwise lead to serious consequences, such as tubal obstruction, pelvic inflammatory disease, ectopic pregnancy, spontaneous abortions and unexplained infertility.

Concomitant infections with human papillomavirus and various mycoplasma and ureaplasma species in women with abnormal cervical cytology

PURPOSE

The objective of the present study is to verify possible association between infections with mycoplasmas and ureaplasmas and the presence of HPV infections in women diagnosed with abnormal cervical cytology.

MATERIAL/METHODS

The investigation included 387 non-pregnant women among whom: 62 were diagnosed with ASCUS, 167 with LSIL, 27 with HSIL, 49 with cervical carcinomas, and 82 females with normal cytology.The presence of HPV infection and identification of both ureaplasma and mycoplasma were confirmed by PCR using specific primers.

RESULTS

HPV infections were demonstrated in 156 females (40%), with mycoplasmas and/or ureaplasmas were confirmed in 93 cases (24%). In HPV-positive patients, infections with mycoplasmas/ureaplasmas were more frequent, particularly for ureaplasmas (U. urealyticum p=0.004, U. parvum p=0.027). The percentage of females infected with U. urealyticum significantly increased in women diagnosed with cervical carcinoma as compared to controls.The statistical analysis demonstrated that the risk of HPV infection while already infected with any of the four analyzed species of Mycoplasmataceae increased two-fold. With concomitant of U. urealyticum infection, the risk of HPV infection was 4.7-fold greater than in the absence U. urealyticum infection.

CONCLUSION

Since the presence of U. urealyticum associates significantly with the HPV infection, genotyping of the ureaplasma species should be recomended.

Simultaneous and rapid differential diagnosis of Mycoplasma genitalium and Ureaplasma urealyticum based on a polymerase chain reaction-restriction fragment length polymorphism

OBJECTIVES

The aim of this investigation was to simultaneously detect and differentiate Mycoplasma genitalium and Ureaplasma urealyticum in female patients suffering from genital complications by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).

MATERIALS AND METHODS

Genital swabs were taken from 210 patients. They were transported to the laboratory in phosphate-buffered saline. For PCR, samples were analysed with genus-specific MyUu-R and MyUu-F primers. This primer set, which was originally designed in our laboratory, amplified a 465 bp fragment (M. genitalium) and a 559 bp fragment (U. urealyticum). Samples containing a band of the expected sizes for the Mycoplasma strains were subjected to digestion with a restriction endonuclease enzyme of TaqI and Cac8I.

RESULTS

Of the 210 samples, a total of 100 (47.6%) samples were found to be positive for Mycoplasmas (seven M. genitalium isolates, 3.3%; and 89 U. urealyticum isolates, 42.4%), and coinfections with both species were detected in four samples (1.9%). The PCR-RFLP results showed that M. genitalium and U. urealyticum are different by enzyme patterns.

CONCLUSION

PCR-RFLP offers a rapid and easily applicable protocol to simultaneous detection and differentiation of M. genitalium and U. urealyticum from clinical samples when specific primers and restriction enzymes are used.

Development of a real-time PCR targeting the yidC gene for the detection of Mycoplasma hominis and comparison with quantitative culture

Mycoplasma hominis is an opportunistic human mycoplasma species that can be either commensal or pathogenic. Its detection by culture is considered to comprise the reference technique. Previously reported PCR techniques target the 16S rRNA or the gap gene, although sequence variations among clinical isolates may lead to variations in clinical sensitivity. The present study aimed to develop a specific TaqMan quantitative real-time PCR assay, targeting a gene conserved in all M. hominis isolates, and to compare it with quantitative culture. With the knowledge of the M. hominis PG21 genome sequence, the yidC gene, encoding a membrane protein translocase, was chosen as target. Its intraspecies heterogeneity was checked at the nucleotide level using 31 reference or clinical strains. The limit of detection, the analytical specificity and the reproducibility of the assay were assessed. Moreover, PCR and culture results were compared using 153 urogenital specimens. The limit of detection was seven copies/μL. The analytical specificity was 100%, with good inter- and intra-assay reproducibility. Among the 153 urogenital specimens, the yidC PCR and culture allowed detection of 55 and 45 M. hominis-positive samples, respectively. Comparison of the bacterial load among the 45 specimens found to be M. hominis-positive by both techniques revealed a statistically significant association between the quantitative results obtained. In conclusion, we developed a specific, sensitive and reproducible real-time PCR to detect all M. hominis clinical isolates. This PCR was shown to have higher sensitivity than culture, although both methods were correlated for quantification of M. hominis loads in urogenital specimens.

Detection and characterization of human Ureaplasma species and serovars by real-time PCR

We designed primers and probes for the detection and discrimination of Ureaplasma parvum and U. urealyticum and their 14 serovars by real-time PCR. The analytical sensitivity and specificity of the multiplex species-specific PCR were determined by testing corresponding American Type Culture Collection (ATCC) type strains, 47 other microbial species, and human genomic DNA. The limits of the multiplex PCR were 2.8 x 10(-2) CFU/microl PCR mixture for detecting U. parvum and 4.1 x 10(-2) CFU/microl PCR mixture for detecting U. urealyticum. Clinical specificity and sensitivity were proven by comparison with culture and traditional PCR. For the detection of any Ureaplasma species, the clinical sensitivity and specificity of real-time PCR were 96.9% and 79.0%, respectively, using culture as a reference. Multiplex real-time PCR was also more sensitive than traditional PCR in discriminating the two Ureaplasma species in culture-positive subcultures. Each of the 14 monoplex serovar-specific PCR assays was specific for the corresponding ATCC type strain serovar. This new species identification PCR is specific and sensitive in the detection of Ureaplasma species in clinical specimens, and the serovar-specific PCR assays are the first set of complete genotypic assays to differentiate all 14 known Ureaplasma serovars. These assays provide quick and reliable means for investigating the epidemiology and pathogenicity of ureaplasmas at the serovar level.

Detection of ureaplasmas by the polymerase chain reaction in the amniotic fluid of patients with cervical insufficiency

AIMS

The purpose of this study was to determine the clinical significance of detecting microbial footprints of ureaplasmas in amniotic fluid (AF) using specific primers for the polymerase chain reaction (PCR) in patients presenting with cervical insufficiency.

METHODS

Amniocentesis was performed in 58 patients with acute cervical insufficiency (cervical dilatation, > or =1.5 cm) and intact membranes, and without regular contractions (gestational age, 16-29 weeks). AF was cultured for aerobic and anaerobic bacteria as well as genital mycoplasmas. Ureaplasmas (Ureaplasma urealyticum and Ureaplasma parvum) were detected by PCR using specific primers. Patients were divided into three groups according to the results of AF culture and PCR for ureaplasmas: those with a negative AF culture and a negative PCR (n=44), those with a negative AF culture and a positive PCR (n=10), and those with a positive AF culture regardless of PCR result (n=4).

RESULTS

1) Ureaplasmas were detected by PCR in 19.0% (11/58) of patients, by culture in 5.2% (3/58), and by culture and/or PCR in 22.4% (13/58); 2) Among the 11 patients with a positive PCR for ureaplasmas, the AF culture was negative in 91% (10/11); 3) Patients with a negative AF culture and a positive PCR for ureaplasmas had a significantly higher median AF matrix metalloproteinase-8 (MMP-8) concentration and white blood cell (WBC) count than those with a negative AF culture and a negative PCR (P<0.001 and P<0.05, respectively); 4) Patients with a positive PCR for ureaplasmas but a negative AF culture had a higher rate of spontaneous preterm birth within two weeks of amniocentesis than those with a negative AF culture and a negative PCR (P<0.05 after adjusting for gestational age at amnio-centesis); 5) Of the patients who delivered within two weeks of amniocentesis, those with a positive PCR for ureaplasmas and a negative AF culture had higher rates of histologic amnionitis and funisitis than those with a negative AF culture and a negative PCR (P<0.05 after adjusting for gestational age at amniocentesis, for each); 6) However, no significant differences in the intensity of the intra-amniotic inflammatory response and perinatal outcome were found between patients with a positive AF culture and those with a negative AF culture and a positive PCR.

CONCLUSIONS

1) Cultivation techniques for ureaplasmas did not detect most cases of intra-amniotic infection caused by these microorganisms (91% of cases with cervical insufficiency and microbial footprints for ureaplasmas in the amniotic cavity had a negative AF culture); 2) Patients with a negative AF culture and a positive PCR assay were at risk for intra-amniotic and fetal inflammation as well as spontaneous preterm birth.

Congenital and opportunistic infections: Ureaplasma species and Mycoplasma hominis

There is strong evidence from clinical and experimental animal studies that ureaplasmas can invade the amnionic sac and induce an inflammatory response resulting in chorioamnionitis, preterm labor and neonatal lung injury. The ability of Ureaplasma spp. and Mycoplasma hominis to cause pneumonia, bacteremia, and meningitis in newborns can no longer be questioned. The association of Ureaplasma spp. with bronchopulmonary dysplasia has been supported by the majority of observational studies, but proof of causality is still lacking. The availability of molecular diagnostic technologies has enabled the designation of the two Ureaplasma biovars as individual species, but additional work must be done to establish whether there is differential pathogenicity between the Ureaplasma spp. or among their respective serovars. Future investigations to prevent prematurity should be directed toward identification and localization of specific micro-organisms combined with targeted antibiotic trials to determine whether such interventions can improve long-term infant outcomes.

Comparison of culture and PCR to detect Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri in ear swabs taken from goats

This study was designed to evaluate the validity of PCR for the direct detection of Mycoplasma (M.) agalactiae and Mycoplasma mycoides subsp. capri (Mmc), as the two species most frequently causing contagious agalactia (CA) in goats. The PCR method was compared with the traditional culture technique to determine which method was most efficient at identifying all auricular carriers present in herds. The samples analyzed were 307 ear swabs taken from goats reared in a CA endemic area. We assessed the validity of each technique to detect each species and agreement between both methods. For each species, the result was taken as true-positive when at least one of the two tests was positive. Of the swabs tested, 246 were scored positive by PCR (235 and 11 for Mmc and M. agalactiae, respectively) and 117 showed a positive culture result (113 for Mmc and 4 for M. agalactiae). 133 of the PCR-positive samples (124 and 9 for Mmc and M. agalactiae, respectively) yielded negative culture results and 4 culture-positive samples tested negative using PCR (2 for each species). Sensitivity and negative predictive values for PCR were 84.62 and 99.32 (for M. agalactiae) and 99.16 and 97.22% (for Mmc) respectively, and for culture were 30.77 and 97.03 (for M. agalactiae) and 47.08 and 36.08% (for Mmc), respectively. PCR proved to be a rapid and sensitive method for the detection of mycoplasmas in the external ear of asymptomatic carriers. Tools such as this are needed to adopt efficient control measures against CA.

Detection of Chlamydia trachomatis and Mycoplasma hominis, genitalium and Ureaplasma urealyticum by polymerase chain reaction in patients with sterile pyuria

PURPOSE

Chlamydia trachomatis and Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum are associated with various diseases of the urogenital tract, but they are usually not detected by routine microbiological diagnosis. To determine the occurrence of Chlamydia trachomatis, Mycoplasma hominis, Mycoplasma genitalium, and Ureaplasma urealyticum in patients with sterile pyuria.

MATERIAL/METHODS

Sterile pyuria urine samples collected during the period from February 2006 to April 2007 were tested by polymerase chain reaction (PCR) for the presence of C. trachomatis, M. hominis, M. genitalium, and U. urealyticum using specific primers for each species. A total of 200 sterile pyuria samples selected from about 2400 urine samples attending the genitourinary clinic at Al-Shifa hospital, Gaza, during the period February 2006 to April 2007 and were analyzed for routine urine examination and cultured on MacConkey agar, blood agar, and sabouraud agar to detect the presence of bacteria and Candida. The 200 samples (96 male, 104 female; aged >or=18 years) containing more than 10 leukocytes / HPF and negative for culture (showing no significant growth after 24 hr) were tested by PCR for C. trachomatis and M. hominis, M. genitalium, and U. urealyticum.

RESULTS

C. trachomatis was detected in 20 samples (10%), U. urealyticum in 10 samples (5%), M. hominis in 6 samples (3%) and M. genitalium in 2 samples (1%). The difference in occurrence of C. trachomatis was statistically insignificant between males and females (P=0.509), but it was significant (P=0.008) for U. urealyticum. M. hominis was detected only in samples collected from female patients. On the other hand, M. genitalium was detected only in men.

CONCLUSION

PCR testing of sterile pyuria showed a significant number of C. trachomatis, Mycoplasma, and Ureaplasma infections. Consequently, PCR is recommended for the detection of those microorganisms in the urine samples of sterile pyuria patients.

Performance of the gen-probe transcription-mediated [corrected] amplification research assay compared to that of a multitarget real-time PCR for Mycoplasma genitalium detection

Mycoplasma genitalium (MG) can cause nongonococcal urethritis and is potentially associated with urethritis, endometritis, and cervicitis. Several assays have been developed to detect MG. Molecular amplification assays for organism detection can be problematic due to the potential for false-positive and false-negative results. Confirmatory testing is often required in these situations, requiring additional time and resources. Use of multigene targets could integrate both detection and verification at lower cost. Utilizing two targets, the MgPa adhesion gene and the 16S rRNA gene, a multitarget real-time (MTRT) PCR for the detection of MG was developed. Samples from patients attending sexually transmitted disease clinics were collected in duplicate. Urine samples from males (n = 286) and self-collected vaginal swabs from females (n = 321) were analyzed by MTRT PCR for MG and the Gen-Probe transcription-mediated [corrected] amplification (TMA) assay, which targets MG rRNA for detection (TMA-MG research use only). Utilizing the criteria of any two targets being positively amplified, the MTRT PCR had a sensitivity and specificity of 91.8% (101 positive samples/110 samples tested) and 99.5% (495/497), respectively, with a positive predictive value (PPV) of 98.1% (101/103) and a negative predictive value (NPV) of 98.2% (495/504). The Gen-Probe TMA-MG assay had a sensitivity, specificity, PPV, and NPV of 98.1% (108/110), 98.1% (488/497), 92.3% (108/117), and 99.5% (488/490), respectively. Comparison between the MTRT PCR and TMA-MG assay by kappa statistic analysis indicated that an overall kappa value was 0.941 (95% confidence interval, 0.907 and 0.976). Both assays demonstrated accuracy in the detection of MG from urine samples from male patients and self-collected vaginal swabs from female patients.

Mycoplasmas and ureaplasmas as neonatal pathogens

The genital mycoplasmas represent a complex and unique group of microorganisms that have been associated with a wide array of infectious diseases in adults and infants. The lack of conclusive knowledge regarding the pathogenic potential of Mycoplasma and Ureaplasma spp. in many conditions is due to a general unfamiliarity of physicians and microbiology laboratories with their fastidious growth requirements, leading to difficulty in their detection; their high prevalence in healthy persons; the poor design of research studies attempting to base association with disease on the mere presence of the organisms in the lower urogenital tract; the failure to consider multifactorial aspects of diseases; and considering these genital mycoplasmas only as a last resort. The situation is now changing because of a greater appreciation of the genital mycoplasmas as perinatal pathogens and improvements in laboratory detection, particularly with regard to the development of powerful molecular nucleic acid amplification tests. This review summarizes the epidemiology of genital mycoplasmas as causes of neonatal infections and premature birth; evidence linking ureaplasmas with bronchopulmonary dysplasia; recent changes in the taxonomy of the genus Ureaplasma; the neonatal host response to mycoplasma and ureaplasma infections; advances in laboratory detection, including molecular methods; and therapeutic considerations for treatment of systemic diseases.

Aetiology of male urethritis in patients recruited from a population with a high HIV prevalence

The aetiology of urethritis, the significance of potential pathogens and the relation of urethritis to HIV infection were determined in 335 men (cases) with and 100 men (controls) without urethral symptoms. Urethral swab specimens were tested for different organisms by PCR or by culture for Neisseria gonorrhoeae. The prevalence of N. gonorrhoeae and Chlamydia trachomatis was 52 and 16%, respectively. The potential pathogens: Mycoplasma genitalium, Ureaplasma urealyticum, Trichomonas vaginalis and herpes simplex virus (HSV), were present in 5, 36, 6 and 6% of the cases respectively. M. genitalium was the only potential pathogen associated with microscopic urethritis. After excluding gonococcal infections, U. urealyticum was more frequent in symptomatic patients, while the prevalence of T. vaginalis was similar among cases and controls. These results strongly suggest an a etiological role for M. genitalium in male urethritis, a possible role for U. urealyticum, but not for T. vaginalis. The control group, with 97% genital ulcer disease patients, was not suitable for the investigation of the role of HSV. The sero-prevalence of HIV was 45%. Current infections were not associated with HIV. However, a history of previous urethral discharge was associated with HIV in a multivariate analysis and supported the hypothesis that non-ulcerative sexually transmitted diseases facilitate HIV transmission.

Development of real-time PCR for the differential detection and quantification of Ureaplasma urealyticum and Ureaplasma parvum

Ureaplasma parvum and Ureaplasma urealyticum are recently recognized species of the genus Ureaplasma. In humans, Ureaplasma spp. can be found on mucosal surfaces, primarily in the respiratory and urogenital tracts. They have been implicated in various human diseases such as nongonococcal urethritis, intrauterine infections in association with adverse pregnancy outcome and fetal morbidity, and pneumonitis in immunocompromised hosts. We have developed two quantitative real-time PCR assays to differentially detect U. parvum and U. urealyticum. Based upon the sequence information of the urease gene (ureB), we designed two TaqMan primer and probe combinations specific for U. parvum and U. urealyticum, respectively. The assays did not react with nucleic acid preparations from 16 bacterial species commonly encountered in relevant clinical specimens, including seven urease-producing species. Each assay had a detection limit of approximately five copies per reaction of the respective gene target. The results suggest that these assays are both sensitive and specific for U. parvum and U. urealyticum. Further investigation of both assays using clinical specimens is appropriate.

High prevalence of genital mycoplasmas among sexually active young adults with urethritis or cervicitis symptoms in La Crosse, Wisconsin

Sexually active young adults in the small college town of La Crosse, Wisconsin, were evaluated for conventional sexually transmitted pathogens and tested for infections with mycoplasmas. The prevalence in 65 symptomatic men or women and 137 healthy volunteers (67 men and 70 women) was compared. Urine specimens from both cohorts were tested by ligase chain reaction for Chlamydia trachomatis or Neisseria gonorrhoeae. In addition, the urethral or cervical swabs from the symptomatic subjects were tested by PCR for Mycoplasma genitalium and cultured for Mycoplasma hominis and the ureaplasmas. The results confirmed a relatively low prevalence of gonorrhea among symptomatic men (12%) and chlamydia among symptomatic men (15%) and normal women (3%). In contrast, infections with mycoplasmas, especially the ureaplasmas (57%), were common and the organisms were the only potential sexually transmitted pathogen detected in 40 (62%) symptomatic subjects. Because of the high prevalence, we also evaluated urethral swabs from an additional 25 normal female volunteers and recovered ureaplasmas from 4 (16%) subjects. Additionally, the participants rarely used protection during sexual intercourse and some symptomatic subjects apparently acquired their infections despite using condoms regularly. The findings demonstrate a strong association between abnormal urogenital findings and detection of myoplasmas, particularly ureaplasmas, and suggest the infections will remain common.

Development of real-time PCR for detection of Mycoplasma hominis

BACKGROUND

Mycoplasma hominis is associated with pelvic inflammatory disease, bacterial vaginosis, post partum fever, sepsis and infections of the central nervous system often leading to serious conditions. Association with development of female infertility has also been suggested, but different publications present different results. We developed a sensitive and fast diagnostic real-time PCR to test clinical samples from women undergoing laparoscopic examination before fertility treatment. To develop a test for the detection and quantification of M. hominis we selected a housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (gap), as a target.

RESULTS

Real-time PCR was optimized to detect 10 copies of M. hominis PG21 genomic DNA. A fluorescence signal was measured for all 20 other M. hominis isolates, and melting curves analysis showed variations in the melting temperature in agreement with sequence variation in the region of the probes. There was no amplification of other mycoplasmal DNA and human DNA. Eighty-three patient cervical swab samples from infertile women were cultured for M. hominis in the BEa medium. Two of the samples (2.4%) were positive after 48 hours of incubation. The real-time PCR detected the same two samples positive, and the DNA concentrations in the clinical specimens were calculated to 37.000 copies/ml and 88.500 copies/ml, respectively.

CONCLUSION

The results demonstrate that real-time PCR may prove to be a rapid alternative to the traditional cultivation method. Information on bacterial load in genital swabs can be obtained. The assay allowed detection of M. hominis in a closed system reducing the risk of contamination by amplicon carry-over.

Comparison of multiplex PCR assay with culture for detection of genital mycoplasmas

Ureaplasma, spp. Mycoplasma genitalium, and Mycoplasma hominis are associated with infection of the genitourinary tract, reproductive failure, and neonatal morbidity and mortality. We have developed a multiplex PCR for the detection of these Mycoplasmatales in a single amplification reaction. The analytical sensitivities of this assay were 10.8, 10.8, and 8.8 CFU for each organism, respectively. This multiplex PCR was compared to culture on 26 cervical swabs, 2 vaginal swabs, 4 female urine specimens, 49 semen samples, 2 male urine specimens, and 1 nonspecified sample. A total of 21 specimens were culture positive (25%); 17 of these were PCR positive. An additional 11 specimens were PCR positive but culture negative. Of the 21 culture-positive specimens, 17 (81%) grew Ureaplasma spp. and 4 (19%) grew Mycoplasma spp. Of the 28 PCR-positive specimens, Ureaplasma spp. was detected in 23 (82%), M. hominis was detected in 3 (11%), and both were detected in 2 (7%). In a confirmatory analysis, all samples were tested by amplification of a second target of the ureaplasma genome. True-positive cases were defined as a positive result by culture or by both amplification assays. The multiplex PCR detected organisms in 26 of the 30 true-positive specimens, as well as in 2 other specimens. Based on a 36% prevalence of infection, the sensitivity, specificity, and positive and negative predictive values of multiplex PCR analyses were 87, 96, 94, and 93%, respectively. Multiplex PCR offers a rapid, sensitive, and easy method to detect genital mycoplasmas.

Mycoplasma Endocarditis: Two Case Reports and a Review

We describe 2 patients with endocarditis for whom blood cultures and cardiac valve cultures were repeatedly sterile. Broad-range eubacterial polymerase chain reaction (PCR) amplification performed on cardiac valve specimens from these 2 patients detected DNA of Mycoplasma hominis, for one patient, and of Ureaplasma parvum, for the other patient. Three other cases of infective endocarditis caused by mycoplasmas were identified in the literature. It is important to rule out a diagnosis of mycoplasma endocarditis because the evolution of the disease may be fatal and it requires an adequate and specific antibiotic therapy.

Human cytomegalovirus transmission from the uterus to the placenta correlates with the presence of pathogenic bacteria and maternal immunity

Prenatal cytomegalovirus infection may cause pregnancy complications such as intrauterine growth restriction and birth defects. How virus from the mother traverses the placenta is unknown. PCR analysis of biopsy specimens of the maternal-fetal interface revealed that DNA sequences from cytomegalovirus were commonly found with those of herpes simplex viruses and pathogenic bacteria. Cytomegalovirus DNA and infected cell proteins were found more often in the decidua than in the placenta, suggesting that the uterus functions as a reservoir for infection. In women with low neutralizing titers, cytomegalovirus replicated in diverse decidual cells and placental trophoblasts and capillaries. In women with intermediate to high neutralizing titers, decidual infection was suppressed and the placenta was spared. Overall, cytomegalovirus virions and maternal immunoglobulin G were detected in syncytiotrophoblasts, villus core macrophages, and dendritic cells. These results suggest that the outcome of cytomegalovirus infection depends on the presence of other pathogens and coordinated immune responses to viral replication at the maternal-fetal interface.

PCR methods in clinical investigations of human ureaplasmas: a minireview

Human ureaplasmas are small, cell-wall-deficient organisms that are implicated in many human infections. Due to their small size and fastidious growth requirements, ureaplasmal infections are hard to diagnose clinically, and ureaplasmal disease is difficult to study in clinical samples. Standard culture methods for ureaplasmas are technically challenging, and 3 to 5 days are required to identify this pathogen. PCR methods have been increasingly used in the diagnosis of these infections and in the study of this pathogen in human specimens from multiple sites. These methods have theoretical advantages over traditional culture methods. Organism identification can occur in the presence of low numbers of bacteria, and viability is not necessary. Rapid identification of organisms within 24 h is also possible. In addition, subtyping of isolates can be performed faster with PCR methods than with culture methods. The use of PCR methods in translational research in multiple human ureaplasmal diseases will be reviewed in this paper, and their usefulness will be compared to culture methods.

Role of erythromycin for treatment of incipient chronic lung disease in preterm infants colonised with Ureaplasma urealyticum

Ureaplasma urealyticum is frequently isolated from tracheal aspirates of very low birthweight infants who go on to develop chronic lung disease. The use of erythromycin has been advocated in ventilated very low birthweight infants who are colonised with U. urealyticum, although the association between U. urealyticum and chronic lung disease remains controversial. There are only two randomised, controlled trials involving a total of 37 U. urealyticum-positive very low birthweight infants. Both trials failed to demonstrate a reduction in the incidence of chronic lung disease after 7 or 10 days of erythromycin. On the other hand, there are reports of rare but serious adverse effects of erythromycin in newborn infants including sudden cardiovascular compromise and hypertrophic pyloric stenosis. We conclude that, at present, there is insufficient evidence to support the use of erythromycin for the treatment of incipient chronic lung disease in very low birthweight infants colonised with U. urealyticum.

The epidemiology of preterm labor

There are many factors that are associated with preterm labor and delivery. These include maternal conditions such as medical illness, anemia and uterine malformation. They may be related to past events such as prior obstetric complication, previous preterm labor, cervical surgery or induced abortion. They may be intrinsic to the current pregnancy, such as reproductive tract infection, multifetal gestation, maternal age, short interpregnancy interval or prolonged menstrual conception interval. Maternal behaviors such as smoking and substance abuse can be risk factors for a short gestation. Demographic variables such as race, employment and socioeconomic status can also be associated with preterm labor. This article briefly reviews these subjects.

Midtrimester vaginal Mycoplasma genitalium in women with subsequent spontaneous preterm birth

OBJECTIVE

We sought to determine the midtrimester prevalence of Mycoplasma genitalium in women who had subsequent spontaneous preterm birth.

STUDY DESIGN

In a prospective study of lower genital tract infections, we identified 127 women who subsequently had spontaneous preterm birth. Vaginal samples were obtained between 21 and 25 weeks' gestation for pH, for bacterial vaginosis Gram stain, and cultures that yielded Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. M genitalium was identified by using validated polymerase chain reaction (PCR) primers, and the results were compared to pregnancy outcomes.

RESULTS

Of 124 women with spontaneous preterm births, only five (3.9%) had PCR assays positive forM genitalium. The mean +/- SD delivery gestational age was similar for women with a positive PCR (34.6 +/- 2.2 weeks) and a negative PCR (34.0 +/- 2.7 weeks) (P =.62). None of the women with positive PCR results tested positive for any other sexually transmitted disease, whereas 36 (30%) women with negative PCR results tested positive.

CONCLUSIONS

The occurrence of M genitalium in the vagina at midtrimester is infrequent in women with subsequent spontaneous preterm birth.

The role of DNA amplification technology in the diagnosis of infectious diseases

Nucleic acid amplification and detection methods developed in the past decade are useful for the diagnosis and management of a variety of infectious diseases. The most widely used of these methods is the polymerase chain reaction (PCR). PCR assays can detect rapidly and accurately the presence of fastidious and slow-growing microorganisms, such as Chlamydia, mycoplasmas, mycobacteria, herpesviruses and enteroviruses, directly from clinical specimens. Commercial PCR assays for the diagnosis of tuberculosis and genital C. trachomatis infection are now routinely used in many diagnostic laboratories. Assays have also been developed that can detect antimicrobial resistance and are used to identify the cause of infection by organisms that cannot be cultivated. The value of viral load measurement by nucleic acid amplification in the management of patients with HIV infection or hepatitis C has also been well established. However, evaluations of this technology for rapid microbial diagnosis have generally been limited by small samples, and the cost of these assays may be as high as Can$125 per test. As nucleic acid amplification methods continue to evolve, their role in the diagnosis and management of patients with infectious diseases and their impact on clinical outcomes will become better defined.

Molecular comparison of Mycoplasma hominis strains isolated from colonized women and women with various urogenital infections

Twenty Mycoplasma hominis strains isolated from colonized women and women with various urogenital infections were investigated for genetic and antigenic homogeneity by different methods. Restriction fragment length polymorphism analysis demonstrated heterogeneity for all strains, with one exception. Two strains sequentially isolated from one patient showed identical patterns. Otherwise, no clonal clustering could be detected within the strains isolated from either of the diagnostic groups. In contrast, SDS-PAGE analysis and the comparison of the immunoblot pattern revealed antigenic similarities of strains isolated from patients with bacterial vaginosis, chorioamnionitis, premature rupture of membranes and preterm delivery as well as endometritis but showed obvious differences in comparison to strains isolated from colonized women.