Serological cross-reactions between Mycoplasma genitalium and Mycoplasma pneumoniae

Antimicrobial treatment and resistance in sexually transmitted bacterial infections

Sexually transmitted infections (STIs) have been part of human life since ancient times, and their symptoms affect quality of life, and sequelae are common. Socioeconomic and behavioural trends affect the prevalence of STIs, but the discovery of antimicrobials gave hope for treatment, control of the spread of infection and lower rates of sequelae. This has to some extent been achieved, but increasing antimicrobial resistance and increasing transmission in high-risk sexual networks threaten this progress. For Neisseria gonorrhoeae, the only remaining first-line treatment (with ceftriaxone) is at risk of becoming ineffective, and for Mycoplasma genitalium, for which fewer alternative antimicrobial classes are available, incurable infections have already been reported. For Chlamydia trachomatis, in vitro resistance to first-line tetracyclines and macrolides has never been confirmed despite decades of treatment of this highly prevalent STI. Similarly, Treponema pallidum, the cause of syphilis, has remained susceptible to first-line penicillin.

Mycoplasma phocimorsus sp. nov., isolated from Scandinavian patients with seal finger or septic arthritis after contact with seals

Seal finger (sealer's finger, spekk finger), an extremely painful hand infection contracted by individuals handling seals, has previously been associated with Mycoplasma phocacerebrale. From 2000 to 2014, six independent strains of a novel Mycoplasma species were isolated at Statens Serum Institut, Denmark, from Scandinavian patients with seal finger (M5725T, M6447, M6620, M6642 and M6879) or septic arthritis (M6921). Prior to the onset of infection, all patients had reported contact with unspeciated seals. All isolates grew within 2-5 days in Friis' modified broth and metabolized glucose and arginine but not urea. Strains M5725T, M6447, M6642 and M6921 also grew in Hayflick-type media. Colonies on agar media were large (0.5-1.0 mm) and had a typical 'fried egg' appearance, reduced tetrazolium, and were digitonin sensitive. Growth occurred at 32 °C but not at 42 °C. Strains were susceptible to doxycycline and moxifloxacin but resistant to azithromycin and erythromycin. The genomes of the six strains were sequenced and relatedness to all known Mycoplasma species was inferred. Phylogenetic analyses using 16S rRNA gene sequences and core genome single nucleotide polymorphisms showed that the isolated strains were highly similar and phylogenetically distinct from all other species within the genus Mycoplasma. The sizes of the genome sequences of the strains ranged from 744 321 to 772409 bp, with a G+C content of 25.0-25.2 mol%. Based on these analyses, we propose a novel species of the genus Mycoplasma with the name Mycoplasma phocimorsus sp. nov. with the first isolate M5725T (NCTC 14922T=DSM 116188T) as the proposed type strain and representative strains M6447, M6620, M6642, M6879 and M6921.

Molecular identification and cross-immunogenic study on two field isolates of Mycoplasma synoviae isolated from broilers in five districts of Khyber Pakhtunkhwa

Background

Mycoplasma synoviae (MS) is an important poultry pathogen causing heavy economic losses Worldwide. Subclinical persistence of this pathogen is the major issue to control its prevalence.

Aim

This study aimed to determine the molecular and cross-immunogenicity of MS among broilers in five Districts of Khyber Pakhtunkhwa (KP).

Methods

This study was conducted by collecting 434 specimen samples from 40 broiler farms and desi poultry in five districts of KP. Specimen samples from the broiler birds (n = 150), broiler farm environment (n = 264), and desi poultry birds (n = 20) were aseptically collected and serially passaged in Modified Frey's broth. The homologous and heterologous antibody reactions were studied in rabbits. Before inoculation into rabbits, the MS isolates were inactivated by formalin and adjuvanted with Montanide.

Results

The overall turbidity prevalence in Frey's broth was observed as 109/434 (25.11%) samples, and these turbidity-positive samples were shifted on Frey's agar. After the appearance of classic fried egg colonies, the Biochemical confirmation was supported by the production of catalase and phosphatase, reduction of tetrazolium, film and spot assay, and fermentation of glucose for species differentiation in avian mycoplasma. The MS prevalence percentage was recorded as 2% (9/434) through biochemical tests. The PCR results showed 0.5% MS prevalence with two field isolates (named MS-1 and MS-2). Both MS-1 and MS-2 field isolates showed similar values (42.2) of homologous geometric mean titer (GMT). While the heterologous GMT for MS-1 serum against MS-2 isolate was lower (27.9) as compared to MS-2 serum against MS1 isolate (38.9). No titer was detected in the control group (Group-III).

Conclusion

In conclusion, the results indicated the existence of MS in broiler birds and high homologous titers recorded between field isolates, which is a perpetual menace to poultry.

High Prevalence of Macrolide and Fluoroquinolone Resistance-Mediating Mutations in Mycoplasma genitalium-Positive Urine Specimens From Saskatchewan

BACKGROUND

Mycoplasma genitalium is an emerging, sexually transmitted infection, which is more prevalent than Chlamydia trachomatis in some regions. An increase in antibiotic resistance, that is, azithromycin and moxifloxacin, recommended for treating M. genitalium infections has been noted. This is the first detailed report on the prevalence of M. genitalium and its antimicrobial resistance in Saskatchewan, Canada.

METHODS

Aptima urine specimens (n = 1977), collected for the diagnosis of C. trachomatis/Neisseria gonorrhoeae, were tested for M. genitalium using the Aptima M. genitalium assay (MG-TMA). Antimicrobial resistance was ascertained using polymerase chain reaction and DNA sequencing of 23S rRNA (azithromycin) and parC (moxifloxacin) from Aptima M. genitalium assay-positive specimens; mutations predictive of resistance were noted.

RESULTS

The prevalence of M. genitalium was 9.6% (189/1977). Predicted resistance to azithromycin (substitutions at positions 2058/2059 in 23S rRNA) was observed in 63.6% (70/110) of the specimens tested, whereas resistance to moxifloxacin (S83I in ParC) was observed in 10.6% (9/85) of the specimens. Mutations in both 23S rRNA and ParC were observed in 2.12% (4/189) of the specimens. Women aged 20 to 24 years had the highest prevalence (18.3%, P < 0.001), and in females, M. genitalium was significantly associated with C. trachomatis or N. gonorrhoeae/C. trachomatis (P < 0.001) coinfection. The prevalence of M. genitalium (9.6%) in the province of Saskatchewan was higher than that of the other 2 bacterial sexually transmitted infections (N. gonorrhoeae (3.09%) and C. trachomatis (6.85%).

CONCLUSIONS

The prevalence of M. genitalium (9.6%) and associated resistance to azithromycin (63.6%) in Saskatchewan high, suggesting that empiric azithromycin therapy may not be adequate for treating M. genitalium infections.

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.

Persistence, immune response, and antigenic variation of Mycoplasma genitalium in an experimentally infected pig-tailed macaque (Macaca nemestrina)

Mycoplasma genitalium is a sexually transmitted pathogen associated with several acute and chronic reproductive tract disease syndromes in men and women. To evaluate the suitability of a pig-tailed macaque model of M. genitalium infection, we inoculated a pilot animal with M. genitalium strain G37 in the uterine cervix and in salpingeal pockets generated by transplanting autologous Fallopian tube tissue subcutaneously. Viable organisms were recovered throughout the 8-week experiment in cervicovaginal specimens and up to 2 weeks postinfection in salpingeal pockets. Humoral and cervicovaginal antibodies reacting to MgpB were induced postinoculation and persisted throughout the infection. The immunodominance of the MgpB adhesin and the accumulation of mgpB sequence diversity previously observed in persistent human infections prompted us to evaluate sequence variation in this animal model. We found that after 8 weeks of infection, sequences within mgpB variable region B were replaced by novel sequences generated by reciprocal recombination with an archived variant sequence located elsewhere on the chromosome. In contrast, mgpB region B of the same inoculum propagated for 8 weeks in vitro remained unchanged. Notably, serum IgG reacted strongly with a recombinant protein spanning MgpB region B of the inoculum, while reactivity to a recombinant protein representing the week 8 variant was reduced, suggesting that antibodies were involved in the clearance of bacteria expressing the original infecting sequence. Together these results suggest that the pig-tailed macaque is a suitable model to study M. genitalium pathogenesis, antibody-mediated selection of antigenic variants in vivo, and immune escape.

Mycoplasma genitalium: from Chrysalis to multicolored butterfly

The history, replication, genetics, characteristics (both biological and physical), and factors involved in the pathogenesis of Mycoplasma genitalium are presented. The latter factors include adhesion, the influence of hormones, motility, possible toxin production, and immunological responses. The preferred site of colonization, together with current detection procedures, mainly by PCR technology, is discussed. The relationships between M. genitalium and various diseases are highlighted. These diseases include acute and chronic nongonococcal urethritis, balanoposthitis, chronic prostatitis, and acute epididymitis in men and urethritis, bacterial vaginosis, vaginitis, cervicitis, pelvic inflammatory disease, and reproductive disease in women. A causative relationship, or otherwise strong association, between several of these diseases and M. genitalium is apparent, and the extent of this, on a subjective basis, is presented; also provided is a comparison between M. genitalium and two other genital tract-orientated mollicutes, namely, Mycoplasma hominis, the first mycoplasma of human origin to be discovered, and Ureaplasma species. Also discussed is the relationship between M. genitalium and infertility and also arthritis in both men and women, as is infection in homosexual and immunodeficient patients. Decreased immunity, as in HIV infections, may enhance mycoplasmal detection and increase disease severity. Finally, aspects of the antimicrobial susceptibility and resistance of M. genitalium, together with the treatment and possible prevention of mycoplasmal disease, are discussed.

Mycoplasma pneumonia: Clinical features and management

Mycoplasma pneumonia is a common respiratory pathogen that produces diseases of varied severity ranging from mild upper respiratory tract infection to severe atypical pneumonia. Apart from respiratory tract infections, this organism is also responsible for producing a wide spectrum of non-pulmonary manifestations including neurological, hepatic, cardiac diseases, hemolytic anemia, polyarthritis and erythema multiforme. This review focuses on molecular taxonomy, biological characteristics, epidemiology, clinical presentation, radiology and various laboratory tools in diagnosis, differential diagnosis, treatment and prevention of mycoplasma pneumonia.

Real-time PCR detection of the mg219 gene of unknown function of Mycoplasma genitalium in men with and without non-gonococcal urethritis and their female partners in England

Real-time PCR was employed to detect a region of the Mycoplasma genitalium mg219 gene, a gene of unknown function, in clinical samples. Amplification of DNA and signal production from 15 other species of human mycoplasmas and 14 other bacteria and viruses did not occur. Using a panel of 208 genital and rectal samples, the sensitivity when compared to the modified mgpa gene (encoding the major surface protein MgPa) real-time PCR assay was found to be 100 % and the specificity of the assay 99.5 % with a positive predictive value of 80 % and a negative predictive value of 100 %. The mg219 gene was found to be in all strains of M. genitalium and was highly conserved. M. genitalium was detected in 3.9 % (11/280, 95 % CI 2.1–6.9) of all male specimens, in 7.7 % (10/130, 95 % CI 4.1–13.7) of patients with non-gonococcal urethritis (NGU) and in 0.7 % (1/150, 95 % CI <0.01–4.1) of patients without urethritis. The presence of M. genitalium was significantly associated with NGU (P ≤0.01; 95 % Cl 0.88–0.98) and non-chlamydial-non-gonococcal urethritis (P=0.0005; 95 % Cl 0.84–0.97).

Analysis identifying common and distinct sequences among Texas clinical strains of Mycoplasma genitalium

Mycoplasma genitalium is a human bacterial pathogen linked to urethritis and other sexually transmitted diseases. Here, we assessed the incidence of M. genitalium infection in patients attending a sexually transmitted disease clinic in San Antonio, TX, by use of diagnostic real-time PCR. Overall, 16.8% of women and 15.1% of men were found M. genitalium positive. Regions of the mgpB gene, which encodes the MgPa adhesin, were amplified from positive clinical specimens and evaluated for sequence variability, which demonstrated transmission of the pathogen between sexual partners. Follow-up analysis of a subset of patient specimens revealed reinfection by a different strain of M. genitalium, indicating the absence of protective immunity. Eighteen DNA sequence variants were obtained and compared with all other available clinical sequences. Detailed analysis revealed silent mutations of six amino acid residues within the encoded region of the MgPa adhesin in numerous clinical strains. In addition, missense mutations of limited numbers of amino acids were observed. Alignment of putative amino acid sequences revealed the simultaneous occurrence of several mutations and the existence of identical or similar protein variants in strains from different locations.

A comparative study of three different PCR assays for detection of Mycoplasma genitalium in urogenital specimens from men and women

The aim of this study was to compare conventional 16S rRNA gene PCR, real-time 16S rRNA gene PCR and real-time Mycoplasma genitalium adhesin protein (MgPa) gene PCR as detection methods for M. genitalium infection. The study also determined the prevalence of M. genitalium in male and female patients attending a sexually transmitted infections clinic in a rural area in the west of Sweden. First void urine (FVU) and/or urethral swabs were collected from 381 men, and FVU and/or cervical swabs and/or urethral swabs were collected from 298 women. A total of 213 specimens were used in the PCR comparative study: 98 consecutively sampled specimens from patients enrolled in the prevalence study, 36 consecutively sampled specimens from patients with symptoms of urethritis and 79 specimens from patients positive for M. genitalium by real-time MgPa gene PCR in the prevalence study. A true-positive M. genitalium DNA specimen was defined as either a specimen positive in any two PCR assays or a specimen whose PCR product was verified by DNA sequencing. The prevalence of M. genitalium infection in men and women was 27/381 (7.1 %) and 23/298 (7.7 %), respectively. In the PCR comparative study, M. genitalium DNA was detected in 61/76 (80.3 %) of true-positive specimens by conventional 16S rRNA gene PCR, in 52/76 (68.4 %) by real-time 16S rRNA gene PCR and in 74/76 (97.4 %) by real-time MgPa gene PCR. Real-time MgPa gene PCR thus had higher sensitivity compared with conventional 16S rRNA gene PCR and had considerably increased sensitivity compared with real-time 16S rRNA gene PCR for detection of M. genitalium DNA. Real-time MgPa gene PCR is well suited for the clinical diagnosis of M. genitalium.

Mycoplasma genitalium, Chlamydia trachomatis, and tubal factor infertility--a prospective study

OBJECTIVE

To determine the presence of M. genitalium and C. trachomatis in women attending fertility clinics and to follow these women for the effects of previous infections or tubal damage on pregnancy rate and outcome.

DESIGN

Prospective study.

SETTING

Fertility clinics and university.

PATIENT(S)

Two hundred twelve couples attending fertility clinics.

INTERVENTION(S)

Blood and cervical swab samples from the women. Tubal status was assessed by culdoscopy and/or laparoscopy.

MAIN OUTCOME MEASURE(S)

Presence of M. genitalium and C. trachomatis was determined by polymerase chain reaction. Serum samples were tested for antibodies against M. genitalium and C. trachomatis.

RESULT(S)

One swap sample was positive to C. trachomatis and none positive to M. genitalium. Thirty of the 194 women had tubal factor infertility (TFI); 23% and 17% of women with TFI had antibodies to C. trachomatis and M. genitalium, respectively, compared with 15% and 4%, respectively, of women with normal tubes; 36% and 14% of women with a self-reported history of pelvic inflammatory disease (PID) were seropositive to C. trachomatis and M. genitalium, respectively, compared with 10% and 6%, respectively, of women without past PID.

CONCLUSION(S)

A strong antibody response against M. genitalium or C. trachomatis but no sign of current or chronic infection was found in women with TFI, indicating that previous infections caused by these microorganisms may have resulted in permanent damage and occlusion of the fallopian tubes.

Symptomatic urethritis is more prevalent in men infected with Mycoplasma genitalium than with Chlamydia trachomatis

OBJECTIVES

To study the prevalence, symptoms, and signs of Mycoplasma genitalium and Chlamydia trachomatis infections in men attending a Swedish STD clinic and to study the criteria for urethritis.

METHODS

A cross sectional study among STD clinic attendees in Orebro, Sweden. Attendees were examined for microscopic urethritis and first void urine (FVU) was tested for M genitalium and C trachomatis.

RESULTS

The prevalence of M genitalium and C trachomatis was 7% (34/512) and 12% (61/512), respectively. Dual infection was diagnosed in four men. In both infections 90% of the patients had signs of microscopic urethritis. M genitalium positive men had symptomatic urethritis significantly more often than those infected with C trachomatis (73% v 40%, RR 1.8; 95% CI 1.2 to 2.7). 63% of female partners of men infected with M genitalium were infected with M genitalium compared with chlamydial infection in 67% of female partners of men infected with C trachomatis. Non-chlamydial non-gonococcal urethritis without evidence of M genitalium infection was diagnosed in 180 men (35%). Symptoms and/or visible discharge were reported in 49% in this group.

CONCLUSIONS

M genitalium is a common infection associated with symptomatic urethritis and with a high prevalence of infected sexual partners supporting its role as a sexually transmitted infection.

Mycoplasma genitalium: the aetiological agent of urethritis and other sexually transmitted diseases

Mycoplasma genitalium was first isolated in 1980 from two of 13 men with non-gonococcal urethritis (NGU). It shares several features with M. pneumoniae, a recognized respiratory tract pathogen. It is extremely difficult to isolate by culture. The development of sensitive and specific polymerase chain reaction (PCR) assays in the early 1990s made clinical studies possible and a significant number of publications have shown a strong association between M. genitalium and NGU, independent of Chlamydia trachomatis. The purpose of this review is to evaluate the currently available information on the associations between M. genitalium and urogenital tract infections in men and women and assess their fulfilment of the Henle-Koch postulates. It is concluded that there is very strong evidence that M. genitalium is a cause of NGU in men and cervicitis in women. Evidence for upper genital tract infections in women has begun to accrue, but further studies are needed. The optimal treatment of M. genitalium infections remains to be determined, but antibiotics of the macrolide group appear to be more active than tetracyclines.

Use of TaqMan 5' nuclease real-time PCR for quantitative detection of Mycoplasma genitalium DNA in males with and without urethritis who were attendees at a sexually transmitted disease clinic

Mycoplasma genitalium is a cause of nongonococcal urethritis, particularly in patients not infected with Chlamydia trachomatis. A quantitative 5' nuclease assay (TaqMan PCR) was developed and validated. The assay detected a fragment of the MgPa adhesin gene by use of a TaqMan MGB (minor groove binder) probe and included an internal processing control to detect PCR inhibition. Urethral swab specimens and first-void urine samples from M. genitalium-positive men were examined, and the M. genitalium DNA load was correlated to symptoms and signs. The assay consistently detected <5 genome copies without cross-reactions with other mycoplasmas. Urine and urethral swab specimens from men with urethritis had higher M. genitalium DNA loads than specimens from men without urethritis. However, a very broad overlap of DNA loads between patients with and without urethritis was observed. Urethral swab specimens from patients with urethral discharge had a significantly higher DNA load than specimens from patients without discharge. This correlation was not found in first-void urine specimens.

Immune response to Mycoplasma pneumoniae P1 and P116 in patients with atypical pneumonia analyzed by ELISA

Background

Serology is often used for the diagnosis of Mycoplasma pneumoniae. It is important to identify specific antigens that can distinguish between the presence or absence of antibodies against M. pneumoniae. The two proteins, P116 and P1, are found to be immunogenic. By using these in ELISA it is possible to identify an immune response against M. pneumoniae in serum samples.

Results

A recombinant protein derived from the P116 protein and one from the P1 protein were used in two ELISA tests, rP116-ELISA and rP1-ELISA. Human serum samples from patients with atypical pneumonia were tested and compared to the results of the complement fixation test. There was a good agreement between the two tests but the rP1-ELISA showed the best discrimination between positive and negative samples.

Conclusion

Two ELISA tests based on recombinant proteins have been analysed and compared to the complement fixation test results. The two ELISA tests were found suitable for use in serodiagnostics of M. pneumoniae infections. The use of specific antigens eliminates the risk of cross reaction to an immune response against other bacteria.

Detection of Mycoplasma genitalium by PCR amplification of the 16S rRNA gene

In order to develop a species-specific PCR for the detection of Mycoplasma genitalium, the sequence of 1,490 bases of the 16S rRNA gene was determined for M. genitalium G37 (type strain) and four Danish isolates of M. genitalium. The sequences of the four Danish strains, mutually different with respect to their MgPa gene, were 100% homologous, although they carried a single common base substitution compared to the type strain. Among members of the Mycoplasma pneumoniae phylogenetic cluster, M. genitalium showed the most-prominent homology to the 16S rRNA sequence of M. pneumoniae (98% homology). From regions showing the least homology to the M. pneumoniae 16S rRNA gene sequence, primers were chosen to amplify DNA from M. genitalium only. Two sets of primers were selected for their ability to detect <10 to 50 M. genitalium genome copies without cross-reactions with M. pneumoniae. The performance of these primers was compared to the performance of two pairs of primers amplifying parts of the MgPa adhesin gene; 1,030 randomly selected specimens submitted for Chlamydia trachomatis culture were screened with one of the 16S rRNA gene primer sets. A total of 41 specimens were found to be positive for this gene; 40 of these could be confirmed by one of the MgPa primer sets, whereas the other MgPa primer set detected only 21 positive specimens out of 40. These results indicate that estimates of the prevalence of M. genitalium in various populations using MgPa PCR primers could be incorrectly low if the PCR primers are located in variable regions of the MgPa gene.

Polymerase chain reaction as a sensitive and rapid method for specific detection of Mycoplasma pneumoniae in clinical samples

The fast diagnosis of Mycoplasma primary atypical pneumonia is impaired by the lack of routinely available culture methods for isolation of Mycoplasma pneumoniae from clinical specimens. Likewise, serological methods commonly used for diagnosis are insensitive and non-specific. In this study, we have established and applied the polymerase chain reaction (PCR) technique to detect M. pneumoniae DNA in clinical samples originating from the respiratory tract. The PCR results were compared with those from culture and serology tests. To standardize the detection of M. pneumoniae by PCR, we first used DNA from culture grown organisms and clinical samples seeded with M. pneumoniae. PCR amplification was performed with M. pneumoniae-specific primers to amplify 144, 153 and 631 bp DNA fragments by using primer pairs MP5-1/MP5-2, P1-178/P1-331 and P1-178/P1-809, respectively. The amplification of the 631 bp DNA fragment was found to be most sensitive for the detection of M. pneumoniae. Using the most sensitive PCR, a total of 47 respiratory specimens from patients suspected of community acquired pneumonia were tested. While none of the specimens were positive for M. pneumoniae in culture, 6 specimens gave positive results by PCR. In 4 out of the 5 PCR positive samples tested serologically, the results were supported by elevated levels of anti-mycoplasma IgG/IgM/IgA. Thus, these results suggest that PCR is the most sensitive method to detect M. pneumoniae in clinical specimens.

High prevalence of Mycoplasma genitalium in the lower genitourinary tract of women attending a sexually transmitted disease clinic in Paris, France

BACKGROUND

Previous studies have suggested that Mycoplasma genitalium is associated with cervicitis and may be a cause of pelvic inflammatory disease. This study attempted to investigate further the possible role of M genitalium in genital symptoms of women attending a sexually transmitted disease (STD) clinic.

GOAL

To determine the prevalence of and the association of clinical and microbiologic features with M genitalium in women presenting with genital symptoms.

STUDY DESIGN

Between April 1994 and June 1996 a prospective study of 170 consecutive women with abnormal vaginal discharge, with or without urethral itching, dysuria, or pelvic pain, was conducted at the STD clinic at Saint-Louis Hospital in Paris. Information was collected on each subject's characteristics, and a clinical vulvar, vaginal, and cervical examination was performed. Cervical, vaginal, and urethral samples were obtained to identify infecting organisms.

RESULTS

DNA of M genitalium was identified by polymerase chain reaction (PCR) at one or more genital sites in 65 women (38%; 95% CI, 31-46%) and was statistically more frequently detected in the vagina (39%) than in the cervix (21%) or urethra (28%) (P = 0.001 and 0.048, respectively). PCR inhibitors were detected in 17 specimens (4%). M genitalium was found in 6/14 (43%) positive for Chlamydia trachomatis, but no significant association between M genitalium and any demographic, clinical, or microbiologic data was noted in univariable or multivariable analysis.

CONCLUSION

This study indicates that M genitalium is frequently encountered in the female genital tract and is not associated with cervicitis or any particular clinical or microbiologic data.

Mycoplasma genitalium: another important pathogen of nongonococcal urethritis

PURPOSE

We reviewed findings on the pathogenic role of Mycoplasma genitalium in nongonococcal urethritis and the treatment of men with M. genitalium positive nongonococcal urethritis.

MATERIALS AND METHODS

We reviewed literature selected from peer reviewed journals listed in MEDLINE and from resources cited in those articles from 1967 to January 2001.

RESULTS

M. genitalium was first isolated from 2 men with nongonococcal urethritis and thereafter it was shown to cause urethritis in subhuman primates inoculated intraurethrally. This mycoplasma has been detected significantly more often in patients with acute nongonococcal urethritis, particularly in those with nonchlamydial nongonococcal urethritis, than in those without urethritis. The prevalence of M. genitalium positive nonchlamydial nongonococcal urethritis is 18.4% to 45.5% of all nonchlamydial nongonococcal urethritis cases. In addition, the persistence of M. genitalium in the urethra after antimicrobial chemotherapy is associated with persistent or recurrent nongonococcal urethritis. M. genitalium is highly susceptible to tetracycline, macrolide and some new fluoroquinolones. The regimen of 100 mg. doxycycline orally twice daily for 7 days, which is recommended for chlamydial nongonococcal urethritis, seems to be effective for M. genitalium positive nongonococcal urethritis, although clinical data to substantiate this regimen are limited.

CONCLUSIONS

The various results reported to date tend to support the proposition that M. genitalium is a pathogen of nongonococcal urethritis. However, currently diagnostic methods for this important mycoplasma are not available in clinical practice. Because of the possible association of the posttreatment presence of M. genitalium in the urethra with persistent or recurrent nongonococcal urethritis, eradication of this mycoplasma from the urethra is essential for managing M. genitalium positive disease. However, clinical data on treating M. genitalium positive nongonococcal urethritis are extremely limited. Thus, further studies are required to develop new diagnostic methods that would be available in clinical settings and establish a new treatment algorithm for nongonococcal urethritis, including M. genitalium positive disease.

Effect of some psychotropic drugs and a barbiturate on mycoplasmas

The inhibitory effect of selected membrane stabilisers on Mycoplasma pneumoniae, M. hominis and Ureaplasma urealyticum was investigated in vitro. The phenothiazine chlorpromazine (CPZ) and the barbiturate thiopental (Leopental(R)) as well as the stereo-isomeric thioxanthene derivatives; cis(Z)-clopenthixol (Zu-clopenthixol(R))/ trans (E)-clopenthixol and cis (Z)-chlorprothixen (Truxal(R))/trans(E)-chlorprothixen, all have antimycoplasmal effect in the range 3.9-312 mg/l, measured as growth inhibition. It was also demonstrated that the enzymatic functions of the different mycoplasma strains, such as breakdown of glucose, arginine and urea, were abolished by concentrations of CPZ that were sufficiently low to allow multiplication of the organisms. A similar effect was obtained with Leopental(R) although the mycoplasmas were generally only half as sensitive to this drug. Also M. gallisepticum and Acholeplasma laidlawii were inhibited by CPZ and Thiopental. The four thioxanthenes were all inhibitory to mycoplasmal growth and the effect was independent of their stereo-isomeric configuration. The clopenthixol stereoisomers, but not the chlorprothixene isomers, inhibited colour change at concentrations lower than those which inhibited growth. While enzyme activity may continue for some time in vitro when classic antibiotics have inhibited mycoplasmal growth, the reverse effect was observed with phenothiazines and thioxanthenes. The membrane stabilisers may be useful tools in the investigation of microbiological activity on the mycoplasma membrane. From these drugs, new 'antibiotics' might be developed with another action than that of the known antimycoplasmal drugs.

Amplified-fragment length polymorphism fingerprinting of Mycoplasma species

Amplified-fragment length polymorphism (AFLP) is a whole-genome fingerprinting method based on selective amplification of restriction fragments. The potential of the method for the characterization of mycoplasmas was investigated in a total of 50 strains of human and animal origin, including Mycoplasma genitalium (n = 11), Mycoplasma pneumoniae (n = 5), Mycoplasma hominis (n = 5), Mycoplasma hyopneumoniae (n = 9), Myco plasma flocculare (n = 5), Mycoplasma hyosynoviae (n = 10), and Mycoplasma dispar (n = 5). AFLP templates were prepared by the digestion of mycoplasmal DNA with BglII and MfeI restriction endonucleases and subsequent ligation of corresponding site-specific adapters. The amplification of AFLP templates with a single set of nonselective primers resulted in reproducible fingerprints of approximately 60 to 80 fragments in the size range of 50 to 500 bp. The method was able to discriminate the analyzed strains at species and intraspecies levels as well. Each of the tested Mycoplasma species developed a banding pattern entirely different from those obtained from other species under analysis. Subtle intraspecies genomic differences were detected among strains of all of the Mycoplasma species analyzed. The extent of polymorphism varied markedly between the analyzed mycoplasmas, comprising pattern similarity levels from 61.7% detected among M. dispar strains to 95.9% detected among M. genitalium strains. The results of the present study provide evidence of the high discriminatory power of AFLP analysis, suggesting the possible applicability of this method to the molecular characterization of mycoplasmas.

Detection and confirmation of Mycoplasma pneumoniae in urogenital specimens by PCR

Following the isolation of Mycoplasma pneumoniae from urogenital specimens (M. Goulet, R. Dular, J. G. Tully, G. Billows, and S. Kasatiya, J. Clin. Microbiol. 33:2823-2825, 1995), a study was undertaken to confirm the observations by PCR. Specific primers directed to the P1 adhesin gene of M. pneumoniae were used. A total of 300 genital specimens were tested for M. pneumoniae and Mycoplasma genitalium by culture and PCR. Of these, 15 were positive by culture and 17 were positive by PCR for M. pneumoniae. No M. genitalium was detected in any of the specimens by either method. The present study demonstrates that PCR is sensitive and rapid compared to cumbersome culture methods and can be used to detect M. pneumoniae in urogenital specimens in a routine diagnostic laboratory.

Mycoplasma genitalium infection and host antibody immune response in patients infected by HIV, patients attending STD clinics and in healthy blood donors

Prevalence of Mycoplasma genitalium in humans is still not clear. We have developed a sensitive and specific serological assay for M. genitalium using lipid-associated membrane proteins (LAMPs) as antigens. Antibodies to LAMPs from M. genitalium showed little cross-reactivity to LAMPs from antigenically similar M. pneumoniae. For validity testing, urines from 104 patients were tested by PCR for M. genitalium. All 15 PCR+ patients had M. genitalium-LAMPs antibodies. Moreover, none of 64 antibody-negative patients were PCR+. Serological study of 1800 patients of various diseased groups and healthy blood donors showed M. genitalium was primarily a sexually transmitted microbe that infected patients with AIDS (44.0%), intravenous drugs users with or without HIV infection (42.5%), and also HIV- patients attending STD clinics (42.6%). Only 5.5% HIV- healthy blood donors and 1.3% HIV+ hemophiliacs tested positive. M. genitalium has been associated with acute non-gonococcal urethritis in male patients. However, many sexually active men and women appear to be chronically infected or colonized by the microbe without apparent clinical symptoms and may continue to transmit the organism through sexual contacts.

Detection of Mycoplasma pneumoniae by polymerase chain reaction in lung aspirates from patients with community-acquired pneumonia

STUDY OBJECTIVE

This study was designed to evaluate the usefulness of polymerase chain reaction (PCR) to detect Mycoplasma pneumoniae DNA in samples obtained by transthoracic needle aspiration (TNA).

DESIGN

Prospective study of cases.

SETTING

A university hospital in Lleida, Spain.

PATIENTS

A total of 101 unselected patients, admitted between January 1993 and March 1994 in the emergency department, with a clinical and radiologic picture of community-acquired pneumonia, and without contraindications for TNA application.

INTERVENTIONS

Patients were studied with conventional diagnostic techniques for community-acquired pneumonia. In addition, a sample obtained by TNA was processed by the following methods: culture in standard media, culture in selective media for Legionella, detection of capsular antigens for Streptococcus pneumoniae and Haemophilus influenzae, and detection of M pneumoniae specific genome by PCR.

RESULTS

Serologic data were not available in eight patients and were excluded from this analysis. M pneumoniae PCR amplification was possible in eight cases, well correlated with serologic responses indicating current infection. Samples from ten additional patients, negative by PCR, were found to be demonstrative of recent M pneumoniae infection by serologic study. Finally, in all the remaining 75 cases, including the 59 patients for whom a different microbial diagnosis was established, M pneumoniae PCR test gave negative results.

CONCLUSION

This study indicates that PCR, applied to samples obtained by TNA, appears to be a moderately sensitive and highly specific method for rapid detection of M pneumoniae lung infection.

Isolation of Mycoplasma genitalium strains from the male urethra

Mycoplasma genitalium is a human mycoplasma species which, on the basis of detection by PCR, has been incriminated as a cause of nongonococcal urethritis. Previously, only two strains from the urogenital tract and five strains from extragenital sites have been isolated. We have developed a method for the isolation of this fastidious microbe. M. genitalium from PCR-positive urethral specimens was initially propagated in Vero cell cultures grown in serum-free medium supplemented with Ultroser HY serum substitute. Growth was monitored by PCR. The M. genitalium strains grown in cell cultures could subsequently be subcultured in modified Friis's FF broth medium. Several passages in broth medium were required before growth on agar medium was attained. A total of 11 urethral specimens positive for M. genitalium by PCR from male patients with urethritis were investigated. Six strains were adapted to growth in broth medium, and four of these strains were cloned. Three specimens were overgrown by other mycoplasmas during propagation in the cell cultures. In only two PCR-positive specimens was propagation of M. genitalium unsuccessful. The use of cell culture combined with PCR monitoring of mycoplasmal growth may prove to be more widely applicable for the isolation of other fastidious mollicutes.

Isolation of Mycoplasma pneumoniae from the human urogenital tract

Mycoplasma pneumoniae is a common etiologic agent of lower respiratory tract infections in humans. However, it has been reported previously that the organism has occasionally been isolated from sites other than the oropharynx and respiratory tract. We report the isolation of 24 strains of M. pneumoniae from urogenital specimens obtained from 22 female patients. Most isolates were of cervical origin from patients attending several local gynecological clinics over a 2-year period. Strains were also isolated from the urethra of one of three healthy male sexual partners of female patients positive for the organism. Single serum specimens obtained from three female patients and three different male sexual partners showed antibody levels suggestive of either recent respiratory infection or genital tract colonization with M. pneumoniae. Although there is no apparent definitive explanation for the localized outbreak of the organism at these unusual sites, the possible transfer through sexual and/or orogenital contact remains the most likely mode of transmission. The occurrence of an organism with obvious pathogenicity for human epithelial tissue in the urogenital tract suggests such transfer could play a role in genital tract infection.

Molecular cloning and characterization of an adherence-related operon of Mycoplasma genitalium

Adhesins and adhesin-related accessory proteins of pathogenic mycoplasmas are required for cytadherence and the subsequent development of disease pathology. The classic example has been Mycoplasma pneumoniae, which causes primary atypical pneumonia in humans. Mutants of M. pneumoniae defective in adhesins (P1 and P30) or in adherence-accessory proteins (HMW1 through HMW4) are unable to colonize host tissues and are avirulent. Mycoplasma genitalium, implicated in nongonococcal, nonchlamydial urethritis, pneumonia, arthritis, and AIDS progression, was found to encode a 140-kDa adhesin that shared both DNA and protein sequence similarities with P1, a major adhesin of M. pneumoniae. In this report, we show that M. genitalium possesses additional homolog sequences to well-characterized adherence-related genes and proteins of M. pneumoniae. The M. genitalium homologs are designated P32 and P69 and correspond to P30 and HMW3 of M. pneumoniae, respectively (J. B. Baseman, p. 243-259, in S. Rottem and I. Kahane, ed., Subcellular biochemistry, vol. 20. Mycoplasma cell membranes, 1993, and D. C. Krause, D. K. Leith, R. M. Wilson, and J. B. Baseman, Infect. Immun. 35:809-817, 1982). Interestingly, the operon-like organizations of P32 and P69 in the M. genitalium genome are similar to the organizations of P30 and HMW3 genes of M. pneumoniae, suggesting that the conservation of these adherence-related genes and proteins might have occurred through horizontal gene transfer events originating from an ancestral gene family.

Mycoplasma pneumoniae and Mycoplasma genitalium mixture in synovial fluid isolate

A mycoplasma cultured from synovial fluid specimens from a patient with pneumonia and subsequent polyarthritis was identified initially as Mycoplasma pneumoniae. In retrospective studies, the culture was shown also to contain Mycoplasma genitalium. In this paper, the laboratory techniques employed in the identification and separation of the two species are presented, and evidence to implicate postinfectious autoimmunity is provided. An increasing number of reports of M. genitalium in human tissue sites and difficulties in isolation and identification of the organism in the clinical laboratory suggest the need for more extensive application of rapid and specific detection systems for both M. genitalium and M. pneumoniae in the clinical laboratory.

Genetic map of the Mycoplasma genitalium chromosome

At 600 kb, the genome of Mycoplasma genitalium is among the smallest known for cellular organisms capable of independent replication. As such, elucidation of the genetic makeup and chromosome architecture of this organism is of considerable interest. We have located 631 markers on the physical map of M. genitalium. The clones have been mapped by hybridizing 20 overlapping cosmid and lambda clones which encompass the entire M. genitalium chromosome to replica filters containing 856 genomic DNA clones. Three hundred fifty-six of these clones represent sequence tag sites, which were previously characterized by database searches. The remaining markers represent clones with an average size of 2.5 kb derived from Sau3A1 partial digestion of genomic DNA. The hybridization data can be divided into three classes: clones which hybridized to only one cosmid; clones which hybridized to two adjacent and overlapping cosmids; and clones which hybridized to several cosmids, which represent repetitive DNA. This rapid approach for placing clones on the physical map has allowed useful comparisons to be made with other bacterial chromosomes, especially that of the closely related organism M. pneumoniae, and has provided insight to the types of events which may have led to the reduction in size of this genome. Future use of these data is discussed.

Intracellular location of Mycoplasma genitalium in cultured Vero cells as demonstrated by electron microscopy

The original two strains of Mycoplasma genitalium were isolated from the human urogenital tract. No other strains have been isolated from this site since then. We have recently succeeded in propagating a third strain from a urogenital specimen from a patient with urethritis in Vero cell cultures. By electron microscopy mycoplasmas were demonstrated intracellularly in about 10% of the examined Vero cells. Various stages of penetration into the cells could be observed. The flask-shaped organisms seemed to penetrate into the cells by the tip-end which included a rodlike structure. The intracellular location of normal mycoplasmas were in membrane-bound vacuoles very close to the nucleus, occasionally together with a few disintegrated organisms. In a few cells additional material was entangling the mycoplasmas in the cytoplasmic vacuoles. The potential for intracellular survival of M. genitalium may help the organism to evade the defence mechanisms of the human body. This trait may be considered a pathogenic property which supports the presumption that M. genitalium has clinical importance.

Mycoplasma genitalium: a cause of male urethritis?

BACKGROUND

Male urethritis may be caused by mycoplasmas. Since Mycoplasma genitalium has previously been isolated from the urethra of two men with non-gonococcal urethritis (NGU), it was the aim of the study further to elucidate its role by measuring the prevalence of this organism in men with NGU.

MATERIAL AND METHODS

The polymerase chain reaction was used. Two different sequences of the gene coding for the main adhesin MgPa were amplified. Urethral, rectal, and throat samples from 99 male sexually transmitted disease (STD) patients with and without urethritis were studied.

RESULTS

M genitalium DNA was demonstrated in 17/99 (17%) of the urethral swabs, but in none of the rectal and throat swabs. Significantly more patients with urethritis (13/52) were positive for M genitalium DNA than were patients without urethritis (4/47) (p < 0.03). In those with urethritis M genitalium DNA was found more often in Chlamydia trachomatis negative NGU (12/34) than in those with chlamydial NGU (1/14) (p = 0.05). Attempts to culture M genitalium from the PCR positive specimens were unsuccessful.

CONCLUSION

M genitalium DNA was found significantly more often in male STD patients with non-chlamydial NGU than in men with chlamydial urethritis (p = 0.05) and in men without urethritis (p = 0.003), suggesting that M genitalium may be a cause of NGU. M genitalium DNA was not demonstrated in any of the throat or rectal swabsindicating that the urogenital tract is probably the primary site of infection or colonisation of this species.

Laboratory diagnosis of Mycoplasma pneumoniae infection. 4. Antigen capture and PCR-gene amplification for detection of the Mycoplasma: problems of clinical correlation

Direct detection assays for Mycoplasma pneumoniae were established by PCR amplification of short sequences within the foot protein/adhesin (P1) gene and the 16S ribosomal RNA gene. Specificity and sensitivity was excellent, no hybridization was observed with M. genitalium and other human Mycoplasma species. In nose and throat washings from subjects with respiratory infection a pattern of high counts (c.f.u./ml) of M. pneumoniae (deduced from the amount of amplified PCR product), and a positive antigen capture assay, was found in 83% of subjects with serological evidence of current infection with M. pneumoniae. A small proportion of subjects with serological patterns suggesting infection in the more distant past had positive PCR assays. This was considered to represent either persistence of the organism from a previous infection or perhaps transient carriage during a reinfection, without substantial change in antibody response. PCR-based assay of M. pneumoniae offers a powerful, rapid, and sensitive substitute for culture of the mycoplasma. Antigen capture, while less sensitive than PCR, offers the advantage that it is more often positive with samples from current infection and requires less stringent laboratory organization to contain false positive results. We conclude however that the laboratory diagnosis of a chosen clinical episode should not rest on the PCR or Ag-EIA assays alone, but must also include antibody assays to confirm whether infection is current or represents persistence from past exposure.

The relationship between prior cervical conization, cervical microbial colonization and preterm premature rupture of the membranes

The occurrence of prior cervical conization and the cervical microbial colonization was investigated in 38 women with idiopathic preterm labor, 35 women with preterm premature rupture of the membranes (PPROM) and 75 normal pregnant women at 26-34 weeks of gestation. Data were analyzed by Fisher's exact test (two-tailed). The frequency of prior cervical conization was significantly higher in PPROM patients compared to normal pregnant women (P < 0.001) and to patients in preterm labor (P < 0.01). Lactobacilli occurred with a lower frequency in patients with PPROM compared to patients in preterm labor (P < 0.05) and control patients (P = 0.0543)-and with a lower frequency in patients with prior cervical conization (P < 0.05). All other microorganisms occurred with the same frequencies in all groups. The absence of lactobacilli may indicate changes in the cervical flora, which could increase the risk of PPROM. Prior cervical conization may impair the antimicrobial defense-mechanisms in the cervix, which could facilitate ascending microbial colonization. This may lead to a release of prostaglandins and proteolytic enzymes and subsequently preterm labor and rupture of the membranes.

Detection of Mycoplasma pneumoniae in clinical samples from pediatric patients by polymerase chain reaction

The polymerase chain reaction (PCR) technique was used to detect Mycoplasma pneumoniae DNA in clinical samples (nasopharyngeal aspirations or bronchoalveolar lavages) obtained from 100 children, 1 month to 16 years old. PCR allowed the detection of M. pneumoniae DNA from 20 out of the 100 patients studied. In 16 cases, PCR positivity was associated with acute respiratory symptomatology. For five PCR-positive patients, a positive culture or a serological response evidenced acute M. pneumoniae infections. A lack of antibody response was observed particularly with immunocompromised children and infants less than 12 months old. The amount of M. pneumoniae DNA in the PCR was estimated in a semiquantitative way by comparison of its hybridization signal with those obtained for 100, 10, and 1 color-changing unit (CCU) of the M. pneumoniae FH strain. Small amounts (less than or equal to 10(2) CCU/ml) of M. pneumoniae were found in samples from asymptomatic patients, while larger amounts (greater than or equal to 10(2) to greater than or equal to 10(4) CCU/ml) were found for 8 out of 10 patients with acute pneumonia.

Enzyme immunoassay for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae

An enzyme immunoassay (EIA) for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae was developed. The EIA was evaluated on the basis of results in the M. pneumoniae complement fixation (MPCF) test and the cold agglutinin test. Serum samples from 430 patients with respiratory infections of known or unknown etiology, from 91 healthy children and adults and from 20 patients with rheumatoid factor, were investigated. By the criteria chosen for positive diagnostic EIA values, we found that the combined measurement of specific IgM and IgG gave a specificity of 99.7% and a sensitivity of 97.8%. If only IgM antibodies were measured, the specificity was 100% and the sensitivity was 88%. For IgG alone the specificity was 99.7%, but the sensitivity was only 46% because of the high EIA cutoff value chosen for IgG. We found no false positives among serum samples from patients with non-M. pneumoniae respiratory infection of known etiology, and there were no false IgM positives due to rheumatoid factor. In some cases the IgM EIA results became positive earlier in the course of illness than the MPCF titer. While children and teenagers responded predominantly with IgM antibodies, patients older than 40 years often had an IgG response only (56% of cases), probably because of reinfection. We conclude that this EIA is a good alternative to the combined MPCF and cold agglutinin tests in the diagnosis of M. pneumoniae infection.

In vitro susceptibilities of Mycoplasma genitalium to antibiotics

The susceptibilities of seven clinical isolates of Mycoplasma genitalium and three strains of Mycoplasma pneumoniae to a variety of antibiotics were examined by an agar dilution method. Macrolides, pristinamycin, and tetracyclines were very active against both species. Sparfloxacin was the most active quinolone tested. None of the 21 antibiotics tested had differential activity toward the two organisms.

Detection and discrimination of Mycoplasma pneumoniae and Mycoplasma genitalium by the in vitro DNA amplification

By using the primers designed on the bases of the sequences of the 16S rRNA genes of Mycoplasma pneumoniae and Mycoplasma genitalium, respectively, specific and sensitive in vitro DNA amplification assay system for the detection and discrimination of these two mycoplasmas was established. The detection limit of the assay was 100 cells for M. pneumoniae and 1,000 cells for M. genitalium. Neither other human mycoplasmas nor oral bacteria existing in human saliva showed any cross-reactions with these primers.

Application of an indirect immunofluorescence test for detection of Mycoplasma pneumoniae in respiratory exudates

We prepared polyclonal antibody specific to Mycoplasma pneumoniae and examined the conditions influencing the ability of an indirect immunofluorescence test to detect the specific antigen in respiratory exudates. The antibody did not cross-react with normal human serum or with respiratory exudates from 10 healthy persons. Cross-reactivity of the antibody with species of mycoplasmas other than M. genitalium was fully diminished when absorbed with horse serum and yeast extract, components of the culture medium. Though the absorbed antibody cross-reacted with M. genitalium, the titer was significantly lower than when tested against M. pneumoniae. Two types of antigen-specific fluorescence were observed in clinical specimens: one is large or small fluorescent granular aggregates found in mucus, and the other is fine fluorescent particles diffused on the entire surface of small epithelial cells. Throat smears from 49 patients with serologically confirmed M. pneumoniae infections were examined by our indirect immunofluorescence method. Positive results were obtained in 42 cases, many of which were positive before a rise in serum antibody titer could be demonstrated, indicating that the method is useful for a preliminary diagnosis at an early stage of the infection.

Ten and a half years seroepidemiology of Mycoplasma pneumoniae infection in Denmark

The study was based on a computerized card index of 9161 patients who had at least one positive blood specimen in the Mycoplasma pneumoniae complement fixation test. A total of 12,562 specimens from these patients had been sent to Statens Seruminstitut from hospitals and general practitioners during a 10.5-year period. The period encompassed a previously described endemic period in a 30-year study of the epidemiological pattern of M. pneumoniae infection in Denmark. The serological data presented support the hypothesis advanced here that a more than sixfold increase of children in day care might have contributed to a change in the epidemiological pattern. The correlation between age and level of specific antibodies, as well as persistence of seropositivity, were also investigated.

Comparison of host responses after intranasal infection of guinea-pigs with Mycoplasma genitalium or with Mycoplasma pneumoniae

Guinea-pigs were infected intranasally with Mycoplasma genitalium or Mycoplasma pneumoniae. The lung lesions produced by the two mycoplasmas were comparable in extent and histological pattern. Sera of both animal groups taken 2 weeks after infection reacted strongly in the complement fixation test with the M. pneumoniae glycolipid extract. In an ELISA using the respective adherence proteins (P1-protein of M. pneumoniae and MgPa of M. genitalium), strong specific activity, but also considerable cross-reactions were found. Epitope analysis by using overlapping octapeptides of a P1-region immunologically active in human M. pneumoniae infections and of the corresponding MgPa-region revealed six common epitopes but also one M. genitalium and two M. pneumoniae specific determinants. For analysis of a possible pathogenicity of M. genitalium in the human respiratory tract species-specific tests have to be developed.

Polymerase chain reaction for detection of Mycoplasma genitalium in clinical samples

We have used the polymerase chain reaction to detect Mycoplasma genitalium in artificially seeded human throat swab samples as well as in clinical material. On the basis of the published nucleotide sequence of the M. genitalium 140-kDa adhesin gene, primers were chosen to produce an amplified fragment of 281 bp. Five different previously isolated strains, including the type strain of M. genitalium, could all be detected by the polymerase chain reaction, and DNAs from other mycoplasmal and bacterial species yielded negative results. The detection limits were estimated to be approximately 50 organisms by inspection of ethidium bromide-stained agarose gels and 4 organisms when a biotinylated oligonucleotide probe was used in filter hybridization. The amplified DNA fragments were subjected to restriction enzyme analysis. DNAs from the five different isolates all possessed EcoRI, SspI, AluI, Sau3AI, and DdeI restriction sites, as predicted from the published sequence. A total of 150 urogenital swabs collected from 100 patients for culturing of Chlamydia trachomatis were tested for the presence of M. genitalium DNA. Ten samples from eight patients were found positive. The amplified DNA fragments from all of our clinical samples possessed the AluI, Sau3AI, and DdeI restriction sites, but three samples from two patients did not contain the SspI site and none of the samples contained the EcoRI site.