Confirmed Mycoplasma pneumoniae endocarditis

Infective Endocarditis Secondary to Mycoplasma pneumoniae

Mycoplasma pneumoniae (MP) is a gram-positive bacterium most commonly associated with community-acquired pneumonia in adults. It can also involve other systems of the body. Cardiovascular complications include pericarditis, myocarditis, congestive cardiac failure, and, rarely, infective endocarditis. We report a case of infective endocarditis secondary to MP infection in an adult. We treated our patient with doxycycline, which showed significant improvement.

Prevalence and clinical characteristics of septicemia in children with Mycoplasma pneumoniae pneumonia

Background

Mycoplasma pneumoniae (MP) pneumonia in children can be challenging to treat, and the impact of MP blood infection is unclear. The present study aims to determine the prevalence and clinical characteristics of MP septicemia among pediatric patients.

Methods

Children hospitalized at our center for MP pneumonia between October 2017 and June 2018 were included. Healthy controls visiting our outpatient clinic for regular physical examinations were also enrolled. MP was detected by real-time polymerase chain reaction (qPCR) analysis of plasma and peripheral blood mononuclear cell (PBMC) samples.

Results

Sixty-one children with MP pneumonia and 30 healthy children were included. Among children with MP infection, 31 (50.8%) were positive for MP by qPCR (19 in plasma samples, 8 in PBMC samples, and 4 in both). All healthy controls were negative for MP by qPCR.

Conclusions

The prevalence of MP septicemia in children with MP pneumonia is moderate. However, detection of MP in blood samples may have limited clinical value for guiding treatment.

[Clinical implications of the genus Mycoplasma]

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

Salvage heart transplantation for Mycoplasma hominis prosthetic valve endocarditis: A case report and review of the literature

Heart transplantation (HT) has been rarely performed in patients with infective endocarditis (IE) and is considered a "last resort" procedure. Orthotropic HT with bicaval technique was performed in a man with culture-negative endocarditis. Mycoplasma hominis was later detected using 16S ribosomal DNA PCR from surgically removed valve tissue. Literature review and previous results are summarized. HT may be considered as salvage treatment in selected patients with intractable IE. In cases when there is no growth in culture, 16S ribosomal DNA PCR sequencing can be used to identify the pathogen in excised valvular tissue. Mycoplasma spp. is extremely uncommon and difficult to diagnose cause of infective endocarditis (IE). There are no proposed or defined criteria for heart transplantation (HT) in patients with refractory IE, and HT has been rarely performed in this setting. We report a case of M hominis prosthetic valve endocarditis diagnosed by 16S ribosomal DNA PCR in a patient who underwent a salvage HT. We reviewed in the literature other cases of IE caused by Mycoplasma spp.

Laboratory Approach to the Diagnosis of Culture-Negative Infective Endocarditis

Blood-culture negative endocarditis (BCNE) accounts for up to 35% of all cases of infective endocarditis (IE) and is a serious life-threatening condition with considerable morbidity and mortality. Rapid detection and identification of the causative pathogen is essential for timely, directed therapy. Blood-culture negative endocarditis presents a diagnostic and therapeutic challenge. Causes of BCNE are varied including: treatment with antibiotic agents prior to blood culture collection; sub-optimal specimen collection; and/or infection due to fastidious (eg. nutritionally variant streptococci), intracellular (eg. Coxiella burnetii, Bartonella species) or non-culturable or difficult to culture organisms (eg. Mycobacteria, Tropheryma whipplei and fungi); as well as non-infective aetiologies. Here, we review aetiological and diagnostic approaches to BCNE including newer molecular based techniques, with a brief summary of imaging investigation and treatment principles.

Mycoplasma pneumoniae: Current Knowledge on Macrolide Resistance and Treatment

Mycoplasma pneumoniae causes community-acquired respiratory tract infections, particularly in school-aged children and young adults. These infections occur both endemically and epidemically worldwide. M. pneumoniae lacks cell wall and is subsequently resistant to beta-lactams and to all antimicrobials targeting the cell wall. This mycoplasma is intrinsically susceptible to macrolides and related antibiotics, to tetracyclines and to fluoroquinolones. Macrolides and related antibiotics are the first-line treatment of M. pneumoniae respiratory tract infections mainly because of their low MIC against the bacteria, their low toxicity and the absence of contraindication in young children. The newer macrolides are now the preferred agents with a 7-to-14 day course of oral clarithromycin or a 5-day course of oral azithromycin for treatment of community-acquired pneumonia due to M. pneumoniae, according to the different guidelines worldwide. However, macrolide resistance has been spreading for 15 years worldwide, with prevalence now ranging between 0 and 15% in Europe and the USA, approximately 30% in Israel and up to 90–100% in Asia. This resistance is associated with point mutations in the peptidyl-transferase loop of the 23S rRNA and leads to high-level resistance to macrolides. Macrolide resistance-associated mutations can be detected using several molecular methods applicable directly from respiratory specimens. Because this resistance has clinical outcomes such as longer duration of fever, cough and hospital stay, alternative antibiotic treatment can be required, including tetracyclines such as doxycycline and minocycline or fluoroquinolones, primarily levofloxacin, during 7–14 days, even though fluoroquinolones and tetracyclines are contraindicated in all children and in children < 8 year-old, respectively. Acquired resistance to tetracyclines and fluoroquinolones has never been reported in M. pneumoniae clinical isolates but reduced susceptibility was reported in in vitro selected mutants. This article focuses on M. pneumoniae antibiotic susceptibility and on the development and the evolution of acquired resistance. Molecular detection of resistant mutants and therapeutic options in case of macrolide resistance will also be assessed.

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.

Late-onset prosthetic valve endocarditis caused by Mycoplasma hominis, diagnosed using broad-range bacterial PCR

We report what is believed to be the first case of late-onset prosthetic valve endocarditis caused by Mycoplasma hominis in a case of blood culture-negative endocarditis. The objective of this report is to emphasize the use of a broad-range PCR technique for bacterial 16S rRNA genes in identifying the causative pathogen, thus enabling targeted antimicrobial treatment.