In vitro susceptibility of Mycoplasma hominis clinical isolates to tetracyclines, quinolones and macrolides

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

Background

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

Case description

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

Conclusion

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

Mycoplasma hominis necrotising pneumonia in an immunocompetent adult male

Mycoplasma hominis, a common coloniser of the urogenital tract, is a rare cause of respiratory infections in an immunocompetent patient. M. hominis lacks a cell wall and can be difficult to identify with standard culture methods posing difficulties in diagnosis and treatment. We describe a case of M. hominis pneumonia in an immunocompetent man in his early 40s without any risk factors presenting with a cavitary lesion who developed empyema and necrotising pneumonia requiring surgical debridement. Identification of M. hominis and subsequent modification of antibiotic therapy led to favourable outcome. M. hominis should be considered in the differential diagnosis of patients with treatment resistant pneumonia especially in patients with trauma, intracranial injury, lung transplant or if immunocompromised. While M. Hominis is naturally resistant to all antibiotics that target cell wall synthesis, we recommend levofloxacin or other fluoroquinolone to most effectively treat with doxycycline as a potential alternative.

Mycoplasma hominis bursitis in a simultaneous pancreas-kidney transplant recipient: case report and literature review

Mycoplasma hominis can be isolated frequently from the genitourinary tract of some healthy individuals. On rare occasions, it acts as a pathogen in immunocompromised patients such as transplant recipients. Here, we describe the case of a 39-year-old man with end-stage kidney disease secondary to diabetic nephropathy who received a simultaneous pancreas-kidney transplant. He developed pancreatitis and arterial thrombosis 2 weeks post-transplant and required a pancreatectomy. His kidney allograft function remained normal. He developed severe left hip pain 2 weeks post-transplant with a trochanteric bursal effusion detected on magnetic resonance imaging. The effusion grew M. hominis. The patient was treated with 100 mg of doxycycline twice daily for 9 months with full resolution of the effusion at 4 months post-treatment. We also review all previously reported M. hominis infections in transplant recipients.

Investigation of fluoroquinolone resistance mechanism in Mycoplasma hominis isolated from urogenital samples in a Chinese hospital

PURPOSE

Mycoplasma hominis is considered among the causes of urogenital infections and shows increasing resistance to fluoroquinolones. However, data regarding the fluoroquinolone resistance mechanism of M. hominis in Southwest China are limited. This study aimed to investigate gene mutations of quinolone resistance-determining regions (QRDRs) of M. hominis isolated from clinical urogenital samples in a Chinese hospital.

METHODOLOGY

Strains of M. hominis were identified by 16S rRNA gene sequencing. The minimal inhibitory concentrations (MICs) of fluoroquinolones were determined by the broth microdilution method, following CLSI guidelines. PCR was used to amplify the QRDRs of the genes gyrA, gyrB, parC and parE. Positive products were sequenced, and gene mutations and amino acid substitutions were analysed by DNAMAN software and BLAST.

RESULTS

The resistance rates of M. hominis to ciprofloxacin (CIP), levofloxacin (LVX), moxifloxacin (MXF) and gatifloxacin (GAT) were 90.5, 85.7, 73.8 and 71.4 %, respectively. A total of 57 isolates of M. hominis were screened, among which 52 strains demonstrated different resistant phenotypes to fluoroquinolones, 41 harboured amino acid substitutions of GyrA S153L, 51 harboured ParC S91I and 22 harboured ParC K144R. ParE A463S and ParC A154T were recorded for the first time and no amino acid change was detected in GyrB.

CONCLUSION

The resistance of M. hominis to fluoroquinolones in Southwest China is mainly related to mutations in QRDRs of either gyrA or parC. High-level resistance is associated with mutations in both DNA gyrase and topoisomerase IV.

Cardiothoracic Transplant Recipient Mycoplasma hominis: An Uncommon Infection with Probable Donor Transmission

The role of infection with Mycoplasma hominis following cardiothoracic organ transplantation and its source of transmission have not been well-defined. Here, we identify and describe infection with M. hominis in patients following cardiothoracic organ transplantation after reviewing all cardiothoracic transplantations performed at our center between 1998 and July 2015. We found seven previously unreported cases of M. hominis culture positive infection all of whom presented with pleuritis, surgical site infection, and/or mediastinitis. PCR was used to establish the diagnosis in four cases. In two instances, paired single lung transplant recipients manifested infection, and in one of these pairs, isolates were indistinguishable by multilocus sequence typing (MLST). To investigate the prevalence of M. hominis in the lower respiratory tract, we tested 178 bronchoalveolar lavage (BAL) fluids collected from immunocompromised subjects for M. hominis by PCR; all were negative. Review of the literature revealed an additional 15 cases of M. hominis in lung transplant recipients, most with similar clinical presentations to our cases. We recommend that M. hominis should be considered in post-cardiothoracic transplant infections presenting with pleuritis, surgical site infection, or mediastinitis. M. hominis PCR may facilitate early diagnosis and prompt therapy. Evaluation for possible donor transmission should be considered.

First human systemic infection caused by Spiroplasma

Spiroplasma species are organisms that normally colonize plants and insects. We describe the first case of human systemic infection caused by Spiroplasma bacteria in a patient with hypogammaglobulinemia undergoing treatment with biological disease-modifying antirheumatic agents. Spiroplasma turonicum was identified through molecular methods in several blood cultures. The infection was successfully treated with doxycycline plus levofloxacin.

Incidence and antibiotic susceptibility of Mycoplasma hominis and Ureaplasma urealyticum isolated in Brescia, Italy, over 7 years

The prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis collected during 2004-2011 were determined. A total of 9956 individuals was analyzed. Identification was performed by use of the mycoplasma IST-2 kit. Antimicrobial susceptibility against doxycycline, josamycin, ofloxacin, erythromycin, tetracycline, ciprofloxacin, azithromycin, clarithromycin, and pristinamycin was also tested by use of this commercial kit. Our results show a prevalence of 1856 positive patients for genital mycoplasmas (18.6 %). Among positive cultures, 89 and 1.1 % of isolates were Ureaplasma urealyticum and Mycoplasma hominis, respectively. For 9.8 % of isolates both urogenital mycoplasmas were grown. Doxycycline was the most active tetracycline for mycoplasma infections, and this is still the drug of first choice. Among macrolides, josamycin and clarithromycin are the most active agents against ureaplasmas; josamycin is also active against mycoplasmas and is an alternative to tetracyclines and erythromycin for mixed infections, especially for pregnant women and neonates. Fluoroquinolones had low efficacy against urogenital mycoplasmas. For Ureaplasma urealyticum, cross-resistance was found between erythromycin and macrolides (except josamycin) (40-80 %) and between erythromycin and ciprofloxacin (79 %). Antibiotic resistance over the test period did not vary significantly. Because of geographical differences among antibiotic resistance, local in-vitro susceptibility testing is recommended to avoid failure of therapy.

Mycoplasma hominis necrotizing pleuropneumonia in a previously healthy adolescent

Background

Mycoplasma hominis is a fastidious micro-organism causing systemic infections in the neonate and genital infections in the adult. It can also be the cause of serious extra-genital infections, mainly in immunosuppressed or predisposed subjects.

Case Presentation

We describe a case of severe pneumonia and pericarditis due to Mycoplasma hominis in a previously healthy adolescent who did not respond to initial therapy.

Conclusions

Mycoplasma hominis could be an underestimated cause of severe pneumonia in immunocompetent patients and should be particularly suspected in those not responding to standard therapy.

Prevalence and antibiotic susceptibility of Mycoplasma hominis and Ureaplasma urealyticum in pregnant women

BACKGROUND

Mycoplasma hominis and Ureaplasma urealyticum are important opportunistic pathogens implicated in urogenital infections and complicated pregnancy. We aimed to study the role of these pathogens in symptomatic and asymptomatic pregnant women and determine their clinical significance and antibiotic susceptibility.

METHODS

One hundred pregnant women were included in the study, 50 symptomatic patients and 50 asymptomatic controls. Duplicate endocervical samples were taken from each individual and analyzed using the Mycoplasma IST-2 kit and A7 agar medium. Antimicrobial susceptibility was tested against doxycycline, josamycin, ofloxacin, erythromycin, tetracycline, ciprofloxacin, azithromycin, clarithromycin, and pristinamycin using the Mycoplasma IST-2 kit.

RESULTS

Twelve symptomatic pregnant women had spontaneous abortions. Of these, eight (66.7%) cases had been colonized with M. hominis and/or U. urealyticum. Of the pregnant women infected with M. hominis and/or U. urealyticum, 40.7% delivered a low birth weight infant. M. hominis was successfully cultured in five women (5%) and U. urealyticum in 27 (27%). Among positive cultures, 15.6% and 84.4% of isolates were M. hominis and U. urealyticum, respectively. M. hominis and U. urealyticum were uniformly susceptible to doxycycline, tetracycline, and pristinamycin, which may be successfully used in the empirical therapy of infected individuals.

CONCLUSIONS

It can be concluded that genital colonization with M. hominis and U. urealyticum may predispose to spontaneous abortion and low birth weight.

Mycoplasma hominis Meningitis in a 24 Week Premature Neonate: Case Report and Short Literature Review

Over the last 20-year period there have been fewer than 10 reported cases of Mycoplasma hominis central nervous system infection in either premature or full term infants. The optimum management of M hominis infection in premature infants is still unclear. We report the case of a premature infant with persistent central nervous system infection caused by M hominis treated successfully with intravenous chloramphenicol. Previous reports of M hominis central nervous infection and its management are reviewed.

Failure of cefoxitin and doxycycline to eradicate endometrial Mycoplasma genitalium and the consequence for clinical cure of pelvic inflammatory disease

Objectives:

As Mycoplasma genitalium is associated with pelvic inflammatory disease (PID), we examined the efficacy of a commonly used PID antimicrobial in treating M genitalium upper genital tract infection.

Methods:

In the PID Evaluation and Clinical Health study of inpatient versus outpatient treatment, 682 women treated with cefoxitin and doxycycline for clinically suspected PID had stored cervical and endometrial specimens available for analysis. In the current sub study, we compared baseline endometritis, short term treatment failure (continued endometritis and pelvic pain 30 days following treatment) and sequelae among women with and without M genitalium, identified using PCR.

Results:

Endometrial M genitalium was associated with baseline endometritis (adjusted OR 3.0, 95% CI 1.5 to 6.1). Among women with a positive baseline M genitalium test, 41% tested positive again 30 days following treatment. Women testing positive compared to those testing negative for M genitalium at baseline had an increased risk of short-term treatment failure (RR 4.6, 95% CI 1.1 to 20.1). Rates of sequelae, including infertility (22%), recurrent PID (31%) and chronic pelvic pain (42%), were high among women testing positive for endometrial M genitalium at baseline. There was a non-significant trend towards increased infertility, chronic pelvic pain and recurrent PID, and decreased pregnancy and live birth following M genitalium infection.

Conclusions:

M genitalium is associated with endometritis and short-term PID treatment failure. Cefoxitin and doxycycline, a Centers for Disease Control and Prevention recommended PID treatment regimen, is ineffective for the treatment of M genitalium upper genital tract infection.

Klinische Bedeutung der Antibiotikaresistenz in Gynäkologie und Geburtshilfe

Antibiotic resistance of microorganisms that cause infections of the urogenital tract is a clinically relevant problem in obstetrics and gynecology. Due to methodological difficulties, resistance testing is rarely used for the management of these infections. Therefore, solid epidemiological data on resistance rates of most involved pathogens are scarce. Antibiotic resistance of several microorganisms appears to be increasing in various areas of the world, mainly Trichomonas vaginalis and Gardnerella vaginalis (metronidazole),Streptococcus agalactiae (macrolides, clindamycin), Mycoplasma hominis (tetracyclines, intrinsically macrolide resistant). In addition,isolated cases of clinical infections caused by multi-resistant Chlamydia trachomatis have been reported. The presence of antibiotic resistance should therefore be considered in patients with an unfavorable course despite adequate antibiotic therapy. In light of the growing problem of antibiotic resistance and the large gaps in our knowledge in this particular area, research efforts in the field of anti-biotic resistance in gynecological infections should be markedly intensified.

Susceptibility testing of Singapore strains of Mycoplasma hominis to tetracycline, gatifloxacin, moxifloxacin, ciprofloxacin, clindamycin, and azithromycin by the Etest method

The minimal inhibitory concentrations of tetracycline, gatifloxacin, moxifloxacin, ciprofloxacin, clindamycin and azithromycin for 28 Singapore clinical Mycoplasma hominis strains were studied using the Etest method. Different incubation conditions did not affect susceptibility categories, except for tetracycline intermediate-susceptibility strains. Tetracycline-susceptibility was only 35.7%. All strains were susceptible to the fluoroquinolones and clindamycin but resistant to azithromycin.