Life-threatening Mycoplasma hominis mediastinitis

Mollicutes-related infections in thoracic surgery including lung and heart transplantation: A systematic review

BACKGROUND

Urogenital Mollicutes, that is, Mycoplasma hominis and Ureaplasma spp., can colonize the urogenital tract. While urogenital colonization is frequent, infections are rare but should not be missed. Furthermore, extragenital infections are even rarer. Over the past years, they have been increasingly documented as a cause of hyperammonemia syndrome (HS) and post-surgical infections. We review the literature on studies focused on post-surgical infections and HS involving urogenital Mollicutes after thoracic surgery including lung (LTR) and heart (HTR) transplantation.

METHODS

A systematic review was performed by searching PubMed/Medline case reports, case series, cohort studies, and clinical trials. Cases of infections and HS by urogenital Mollicutes after HTR and LTR transplantations were reported.

RESULTS

Overall, urogenital Mollicutes were associated with 15 HS, 31 infections in HTR and LTR, and 18 post-thoracic surgical infections in another context. Post-surgical infections were reported in all contexts. They were mainly due to M hominis, the only species that could cultivate on standard enriched agar forming pinpoint colonies after 3-5 days of incubation. Microbiologists should be prompted to pinpoint colonies even if the examination of Gram-staining is negative. The patients' management required surgical treatment and antimicrobials, almost always tetracyclines and/or fluoroquinolones. Conversely, HS occurred almost exclusively in bilateral LTR and is more likely due to Ureaplasma spp. As Ureaplasma spp. do not cultivate on standard media, the microbiological diagnosis was performed using molecular methods.

CONCLUSIONS

Infections involving urogenital Mollicute should be considered in LTR with HS. The overall rate of mortality is high and might be due in part to delay in etiologic diagnosis. Post-surgical infections were reported in all contexts. The route of contamination with Mollicutes remains unknown in HTR and non-transplant surgery, but evidence of transmission from donors has been documented for LTR.

Isolation of Mycoplasma salivarium in the empyema of a diabetic patient with deep neck infection and necrotizing mediastinitis: A case report

Mycoplasma species (spp.) are predominantly found in the human oropharynx, and extracavity infections are rare. Conventional culture limitations hinder Mycoplasma spp. recovery, potentially causing overlooked infections. Molecular techniques reveal their roles in various infections. Mycoplasma pneumoniae causes pneumonia, while Mycoplasma salivarium (M. salivarium) in empyema is scarcely reported. We present a case of a 61-year-old man who suffered from tonsillitis, deep neck infection, necrotizing mediastinitis, and bilateral pleural infections. Mixed pathogens, mainly M. salivarium, were implicated.

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.

A Case Report of Mycoplasma hominis Subdural Empyema Following Decompressive Craniotomy, and a Review of Central Nervous System Mycoplasma hominis Infections

Background

Mycoplasma hominis is a small cell-wall-free organism, part of the normal microbiota of the genitourinary tract. It is rarely involved in extragenital infections, mainly joint, surgical-site, and respiratory infections.

Methods

We describe a case of M. hominis subdural empyema and lower limb surgical site infections, following decompressive craniotomy, after traumatic brain and extremities injury. In addition, a literature review of 34 cases M. hominis CNS infections was done.

Results

Our case depicts a 25-years old patient who developed subdural empyema and surgical site infections in his cranium and fibula. Both sites were cultured, and small pinpoint colonies grew on blood agar. MALDI-TOF MS identified M. hominis. Simultaneously 16S-rDNA PCR from CSF detected M. hominis. Antimicrobial treatment was switched to doxycycline with improvement. Literature review revealed 21 adults and 13 pediatric cases of M. hominis CNS infection. Risk factors in adults were head trauma, neurosurgery, or post-partum period.

Conclusions

Based upon the literature reviewed, we postulate that adult patients with head trauma or neurosurgical procedure, rarely are infected either through direct contamination during the trauma, or by undergoing urgent, urinary catheterization, and may experience distant infection due to translocation of M. hominis into the bloodstream. In such cases diagnosis is delayed due to difficulties in growing and identifying the bacteria. Empiric antimicrobials are usually not effective against mycoplasmas. These factors contributed to the mortality in adult cases (15%). Our rare case highlights the necessity of combining classical microbiology routines with advanced molecular techniques to establish a diagnosis in complicated cases.

Lung Abscess and Recurrent Empyema After Infection With Mycoplasma hominis: A Case Report and Review of the Literature

Mycoplasma hominis is a rarely identified cause of respiratory infection that can cause significant morbidity and mortality in immunocompromised patients. It is often missed due to the difficult detection of the organism with routine laboratory methods.

We present the case of a 63-year-old male with a history of lymphoma who was transferred to our hospital with recurrent right-sided empyema and lung abscess in the right lower lobe. Advanced microbiological analysis finally revealed infection with M hominis. Despite appropriate antibiotic treatment, prolonged drainage as well as repeated surgery, which eventually resulted in right lower bilobectomy, were necessary for clinical improvement of our patient.

Infection with M hominis may be more prevalent than previously indicated and can cause severe morbidity and mortality in thoracic surgery patients. Due to the diagnostic challenge, the appropriate antimicrobial treatment is often delayed. Inherent resistance to macrolides and inactivity of cell wall-active agents potentially complicate empiric antibiotic therapy. A review of the currently available literature enables a better understanding of the diagnostic difficulties and importance of this infection.

Intracranial Mycoplasma hominis infection following emergent craniectomy

We present a case of a young healthy female who developed recurrent cranial wound infections after a traumatic injury, the etiologic organism finally identified as Mycoplasma hominis, an uncommon and difficult to isolate bacterium.

Mycoplasma hominis: An under recognized pathogen

Mycoplasma hominis, a commensal of the genital tract, is a potential underestimated pathogen causing both genitourinary and extragenital infections including neonatal infections. Septic arthritis, prosthetic joint infection, central nervous system (CNS) infections, infective endocarditis and abscess formation are common extragenital infections associated mainly with immunocompromised patients. Mycoplasma hominis lipoproteins play an important role in pathogenicity and directly interact with the host immune system. Polymerase chain reaction (PCR) is the mainstay of diagnosis. Increasing resistance to tetracyclines and quinolones which are used for treatment, is a matter of global concern. We reviewed PubMed literature and Google search engine on the recent developments of association of Mycoplasma hominis with various diseases, pathogenesis, diagnosis and treatment.

Submicron Particle and Cell Concentration in a Closed Chamber Surface Acoustic Wave Microcentrifuge

Preconcentrating particulate and cellular matter for their isolation or detection is often a necessary and critical sample preparation or purification step in many lab-on-a-chip diagnostic devices. While surface acoustic wave (SAW) microcentrifugation has been demonstrated as a powerful means to drive efficient particle concentration, this has primarily been limited to micron dimension particles. When the particle size is around 1 μm or below, studies on SAW microcentrifugation to date have shown that particle ring-like aggregates can only be obtained in contrast to the localized concentrated clusters that are obtained with larger particles. Considering the importance of submicron particles and bioparticles that are common in many real-world samples, we elucidate why previous studies have not been able to achieve the concentration of these smaller particles to completion, and we present a practical solution involving a novel closed chamber configuration that minimizes sample heating and eliminates evaporation to show that it is indeed possible to drive submicron particle and cell concentration down to 200 nm diameters with SAW microcentrifugation over longer durations.

Mycoplasma hominis Infections Transmitted Through Amniotic Tissue Product

Background

Mycoplasma hominis is a commensal genitourinary tract organism that can cause infections outside the genitourinary tract. We investigated a cluster of M. hominis surgical site infections in patients who underwent spine surgery, all associated with amniotic tissue linked to a common donor.

Methods

Laboratory tests of tissue product from the donor, including culture, quantitative real-time polymerase chain reaction (qPCR), and whole-genome sequencing were performed. Use of this amniotic tissue product was reviewed. A multistate investigation to identify additional cases and locate any unused products was conducted.

Results

Twenty-seven tissue product vials from a donor were distributed to facilities in 7 states; at least 20 vials from this donor were used in 14 patients. Of these, 4 of 14 (29%) developed surgical site infections, including 2 M. hominis infections. Mycoplasma hominis was detected by culture and qPCR in 2 unused vials from the donor. Sequencing indicated >99% similarity between patient and unopened vial isolates. For 5 of 27 (19%) vials, the final disposition could not be confirmed.

Conclusions

Mycoplasma hominis was transmitted through amniotic tissue from a single donor to 2 recipients. Current routine donor screening and product testing does not detect all potential pathogens. Clinicians should be aware that M. hominis can cause surgical site infections, and may not be detected by routine clinical cultures. The lack of a standardized system to track tissue products in healthcare facilities limits the ability of public health agencies to respond to outbreaks and investigate other adverse events associated with these products.

Mycoplasma hominis Empyema in an 18-Year-old Stem Cell and Lung Transplant Recipient: Case Report and Review of the Literature

Mycoplasma hominis has been identified as a rare cause of respiratory infections in immunocompromised adults. Here, we describe a case of Mycoplasma hominis empyema in an 18-year-old immunocompromised patient with a review of the literature highlighting diagnostic challenges associated with this infection.

Meningitis in a Chinese adult patient caused by Mycoplasma hominis: a rare infection and literature review

Background

Mycoplasma hominis, a well known cause of neonatal infection, has been reported as a pathogen in urogenital infections in adults; however, central nervous system (CNS) infections are rare. We report here the first case of M. hominis meningitis in China, post neurosurgical treatment for an intracerebral haemorrhage in a 71-year-old male.

Case presentation

We describe a 71-year-old man who developed M. hominis meningitis after neurosurgical treatment and was successfully treated with combined azithromycin and minocycline therapy of 2 weeks duration, despite delayed treatment because the Gram stain of cerebrospinal fluid (CSF) yielded no visible organisms. The diagnosis required 16S rDNA sequencing analysis of the cultured isolate from CSF. Literature review of M. hominis CNS infections yielded 19 cases (13 instances of brain abscess, 3 of meningitis, 1 spinal cord abscess and 1 subdural empyema each). Delay in diagnosis and initial treatment failure was evident in all cases. With appropriate microbiological testing, antibiotic therapy (ranging from 5 days to 12 weeks) and often, multiple surgical interventions, almost all the patients improved immediately.

Conclusions

Both our patient findings and the literature review, highlighted the pathogenic potential of M. hominis together with the challenges prompted by rare infectious diseases in particular for developing countries laboratories with limited diagnostic resources.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1885-4) contains supplementary material, which is available to authorized users.

Mycoplasma hominis Induces Mediastinitis after a Tonsillar Abscess

Mycoplasma hominis is commonly involved in genitourinary tract infections. We report a 59-year-old man who developed a M. hominis-associated mediastinitis following acute tonsillar infection.

Mycoplasma hominis, a Rare but True Cause of Infective Endocarditis

Mycoplasma spp. are rarely recognized agents of infective endocarditis. We report a case of Mycoplasma hominis prosthetic valve endocarditis diagnosed by 16S ribosomal DNA (rDNA) PCR and culture of valves in a 74-year-old man. We reviewed the literature and found only 8 other cases reported.

A new case of Mycoplasma hominis mediastinitis and sternal osteitis after cardiac surgery

We report a case of nosocomial mediastinitis and sternal osteitis due to M. hominis after open-heart surgery in an immuno-competent patient. This infection has been diagnosed by incubating the culture media for an extended period of time, and sequencing 16S rDNA directly from the clinical samples.

Vacuum-assisted closure (VAC)-Instill(®) with continuous irrigation for the treatment of Mycoplasma hominis mediastinitis

A 56-year-old patient who underwent ascending aorta replacement postoperatively developed mediastinitis with atypical Mycoplasma hominis. We present the first successful treatment of M. hominis mediastinitis after cardiac surgery with vacuum-assisted closure (VAC)-Instill(®) therapy combined with dilute antiseptic irrigation for bacterial eradication.

Cluster or coincidence? An unusual cause of surgical site infections in adult trauma patients

Mycoplasma hominis is a bacteria that colonizes and infects the genitourinary tract; extragenital infections are not common. Three surgical site infections because of M hominis in immunocompetent adult trauma patients were detected at our facility in a 6-month time period. We investigated this case series and hypothesize transmission based on common exposures.

Mycoplasma hominis mediastinitis after acute aortic dissection repair

We report a case of ascending aortic graft infection by an atypical bacteria, Mycoplasma hominis, with mediastinitis, a dreaded complication after cardiac surgery. A 55-year-old patient underwent ascending aorta replacement for acute type A dissection. He developed sternal instability and purulent discharge, requiring sternal wire removal and debridement. Cultures were initially sterile, but showed M. hominis infection after a significant delay and in specific culture media. The patient was treated with doxycycline and moxifloxacine. Cultures became negative and the sternum was closed on the 28th postoperative day after the first debridement. Recovery was favorable, with no signs of infection. Antibiotics were continued for one year. The patient is still asymptomatic 16 months after antibiotic interruption. Atypical organisms should be considered in the differential diagnosis of acute mediastinitis of unknown etiology after routine microbiological investigations.

Direct 16S rRNA gene sequencing from clinical specimens, with special focus on polybacterial samples and interpretation of mixed DNA chromatograms

RipSeq (iSentio, Bergen, Norway) is a web-based application for the analysis of mixed DNA chromatograms. It opens the possibility to analyze chromatograms obtained by direct 16S rRNA gene sequencing from polybacterial human clinical samples. In this study, we used direct 16S rRNA gene sequencing to investigate 264 samples from a wide range of suspected human bacterial infections. The sequence-based identification was compared with the results from routine culture-based identification. A total of 151 samples were positive by the first PCR, producing 85 pure and 66 mixed DNA chromatograms. All mixed chromatograms were analyzed by RipSeq, although seven were so complex that only the dominant bacterial sequences could be identified. In general, sequence-based identification detected a larger number of species than did culture for samples from patients who had received antibiotics prior to sample collection and for samples containing anaerobic bacteria. RipSeq made it possible to apply this supplementary diagnostic tool to typical polybacterial specimens, such as internal abscesses, pleural fluids, and bile.

Abscess formation due to Mycoplasma hominis infection after cesarean section

A 27-year-old female patient underwent cesarean section and a postoperative hematoma occurred at the site of the uterine incision. The patient underwent relaparotomy to remove the hematoma. Four days later she developed a fever of over 39 degrees C and an abscess had formed at the site. Despite therapy with several antimicrobial agents, her fever persisted. Consequently, she underwent transvaginal abscess drainage, after which she promptly became afebrile. Mycoplasma hominis was considered to be the primary causative organism. There are two reasons that could explain why the wound infection became serious: (i) M. hominis is resistant to several antimicrobial agents that are usually used to treat obstetric infections; and (ii) a long time is required to identify the pathogen. In conclusion, M. hominis should be considered as a causative organism if an antimicrobial-resistant infection occurs at the surgical site after a cesarean section.

[Two cases of septic arthritis by Mycoplasma hominis after total knee replacement arthroplasty]

Mycoplasma hominis has been related with pelvic inflammatory illnesses and postpartum and neonatal infections. Extragenital M. hominis infections are rare, but septicemia, septic arthritis, wound infection, meningitis, and other infections in Immunocompromised patients have also been described. Here we report two cases of septic arthritis caused by M. hominis in patients following total knee replacement arthroplasty. After the surgery, the patients presented with knee pain and clinical signs of infection, such as fever, erythema and swelling on the surgical site. Arthroscopic debridement operations were performed on the surgical site. M. hominis was isolated from the joint fluid and identified by the microscopic visualization of the typical "fried-egg-type" colonies on Mycoplasma specific agar (pleuropneumonia-like organism agar). It was also confirmed by 16S rRNA sequencing. To the best of our knowledge, this is the first report of prosthetic joint infections with M. hominis in Korea.

Spontaneous bacterial pericarditis with tamponade due to Ureaplasma spp

Infectious pericardial effusion with tamponade is an uncommon but life-threatening disease. We report an unusual case of spontaneous Ureaplasma pericardial effusion with tamponade associated with pneumonia, pleural effusion, and urinary tract infection. All published cases of clinically invasive Ureaplasma infections in the adult population are also reviewed.

Post-operative mediastinitis, pleuritis and pericarditis due to Mycoplasma hominis and Ureaplasma urealyticum with a fatal outcome

Post-sternotomy mediastinitis, although infrequent, is a potentially life-threatening complication of cardiac surgery. We report an unusual case of Mycoplasma hominis and Ureaplasma urealyticum post-surgical mediastinitis with persistent pleural and pericardial effusion. Clinical manifestations and response to therapy are described, and the difficulties of establishing the diagnosis are discussed.

Mycoplasma hominis osteitis in an immunocompetent man

Mycoplasma hominis has been associated with pelvic inflammatory illness, postpartum and neonatal infections and respiratory tract diseases. It is rarely isolated from patients with other infections. Reported here is a case of tibial osteitis that occurred in a 16-year-old immunocompetent man. Clinical and laboratory findings improved under treatment with clindamycin and fluoroquinolones.

Culture-Negative Surgical Site Infections

BACKGROUND

The appearance of postoperative surgical site infection (SSI) in the absence of culturable bacterial pathogens is a common dilemma for the surgeon.

METHODS

The literature was searched through references to primary articles, as well as a MEDLINE review, for reports of culture-negative SSIs.

RESULTS

Potential causes of culture-negative SSIs include prior antimicrobial therapy; the presence of fastidious or slow-growing microorganisms such as mycobacteria, Mycoplasma spp., and Legionella spp.; infection caused by mundane bacteria that may be dismissed as "contaminants"; factitious infection; and others.

CONCLUSIONS

We review the recognized causes of "culture negative" SSIs and discuss the laboratory capabilities that may enhance recognition of many of these pathogens and management options.

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.

Mycoplasma disease and acute chest syndrome in sickle cell disease

BACKGROUND

Acute chest syndrome (ACS) is the leading cause of hospitalization, morbidity, and mortality in patients with sickle cell disease. Radiographic and clinical findings in ACS resemble pneumonia; however, etiologies other than infectious pathogens have been implicated, including pulmonary fat embolism (PFE) and infarction of segments of the pulmonary vasculature. The National Acute Chest Syndrome Study Group was designed to identify the etiologic agents and clinical outcomes associated with this syndrome.

METHODS

Data were analyzed from the prospective study of 671 episodes of ACS in 538 patients with sickle cell anemia. ACS was defined as a new pulmonary infiltrate involving at least 1 complete segment of the lung, excluding atelectasis. In addition, the patients had to have chest pain, fever >38.5C, tachypnea, wheezing, or cough. Samples of blood and deep sputum were analyzed for evidence of bacteria, viruses, and PFE. Mycoplasma pneumoniae infection was determined by analysis of paired serologies. Detailed information on patient characteristics, presenting signs and symptoms, treatment, and clinical outcome were collected.

RESULTS

Fifty-one (9%) of 598 episodes of ACS had serologic evidence of M pneumoniae infection. Twelve percent of the 112 episodes of ACS occurring in patients younger than 5 years were associated with M pneumoniae infection. At the time of diagnosis, 98% of all patients with M pneumoniae infection had fever, 78% had a cough, and 51% were tachypneic. More than 50% developed multilobar infiltrates and effusions, 82% were transfused, and 6% required assisted ventilation. The average hospital stay was 10 days. Evidence of PFE with M pneumoniae infection was seen in 5 (20%) of 25 patients with adequate deep respiratory samples for the PFE assay. M pneumoniae and Chlamydia pneumoniae was found in 16% of patients with diagnostic studies for C pneumoniae. Mycoplasma hominis was cultured in 10 (2%) of 555 episodes of ACS and occurred more frequently in older patients, but the presenting symptoms and clinical course was similar to those with M pneumoniae.

CONCLUSIONS

M pneumoniae is commonly associated with the ACS in patients with sickle cell anemia and occurs in very young children. M hominis should be considered in the differential diagnosis of ACS. Aggressive treatment with broad-spectrum antibiotics, including 1 from the macrolide class, is recommended for all patients as well as bronchodilator therapy, early transfusion, and respiratory support when clinically indicated.

Mycoplasma hominis infection in heart and lung transplantation

"Culture-negative" wound infection and mediastinitis secondary to Mycoplasma hominis have been reported after cardiothoracic surgery but no case cluster has ever been described. We report 4 cases of infection in 3 cardiac and 1 bilateral sequential lung transplant recipient over 3 weeks of hospitalization. Successful treatment was achieved with early aggressive surgical intervention and combination antibiotics of clindamycin, doxycycline and/or ciprofloxacin. This cluster raises the question of nosocomial transmission of infection and supports a recommendation for single-room isolation and universal precautions for infected individuals.