Outbreak of Mycoplasma pneumoniae-Associated Stevens-Johnson Syndrome

Comprehensive bioinformatics analysis of Mycoplasma pneumoniae genomes to investigate underlying population structure and type-specific determinants

Mycoplasma pneumoniae is a significant cause of respiratory illness worldwide. Despite a minimal and highly conserved genome, genetic diversity within the species may impact disease. We performed whole genome sequencing (WGS) analysis of 107 M. pneumoniae isolates, including 67 newly sequenced using the Pacific BioSciences RS II and/or Illumina MiSeq sequencing platforms. Comparative genomic analysis of 107 genomes revealed >3,000 single nucleotide polymorphisms (SNPs) in total, including 520 type-specific SNPs. Population structure analysis supported the existence of six distinct subgroups, three within each type. We developed a predictive model to classify an isolate based on whole genome SNPs called against the reference genome into the identified subtypes, obviating the need for genome assembly. This study is the most comprehensive WGS analysis for M. pneumoniae to date, underscoring the power of combining complementary sequencing technologies to overcome difficult-to-sequence regions and highlighting potential differential genomic signatures in M. pneumoniae.

Erythema Multiforme in Children and Mycoplasma pneumoniae Aetiology

Erythema multiforme (EM) in children is understudied and confused with Stevens-Johnson syndrome (SJS) despite their being separate diseases with unique aetiologies and clinical presentations. The goal of this study was to determine the prevalence of Mycoplasma pneumoniae in paediatric patients with EM minor, EM major (EMM), and SJS. This retrospective cohort at The Hospital for Sick Children accrued all cases of EM minor, EMM, and SJS from 1999 to 2013. Sixty-five cases were identified: 20 of EM minor, 23 of EMM, and 22 of SJS. Aetiologies were attributed in 58% of cases: 79% infection and 21% drug aetiology. Sixty-one percent of patients with EMM were M pneumoniae positive, compared with 14% of those with SJS and 22% of those with EM minor ( P < .01). M pneumoniae patients were older at presentation ( P = .03) and more frequently had sore throat ( P < .01) and atypical targets with central blistering ( P < .01). These findings suggest that M pneumoniae should be suspected and treated until laboratory confirmation becomes available in patients presenting with atypical target lesions with central blistering.

Detection of macrolide resistant Mycoplasma pneumoniae in England, September 2014 to September 2015

Mycoplasma pneumoniae infection can cause pneumonia, particularly in children. Global increase in macrolide-resistant M. pneumoniae is of concern due to limited therapeutic options. We describe the detection of macrolide resistance-conferring mutations in 9.3% of 43 clinical specimens where M. pneumoniae was detected in England and Wales from September 2014‒September 2015. This study aims to impact by highlighting the presence of macrolide resistance in M. pneumoniae positive patients, promoting increased clinical vigilance.

The Evolution of Advanced Molecular Diagnostics for the Detection and Characterization of Mycoplasma pneumoniae

Over the past decade there have been significant advancements in the methods used for detecting and characterizing Mycoplasma pneumoniae, a common cause of respiratory illness and community-acquired pneumonia worldwide. The repertoire of available molecular diagnostics has greatly expanded from nucleic acid amplification techniques (NAATs) that encompass a variety of chemistries used for detection, to more sophisticated characterizing methods such as multi-locus variable-number tandem-repeat analysis (MLVA), Multi-locus sequence typing (MLST), matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), single nucleotide polymorphism typing, and numerous macrolide susceptibility profiling methods, among others. These many molecular-based approaches have been developed and employed to continually increase the level of discrimination and characterization in order to better understand the epidemiology and biology of M. pneumoniae. This review will summarize recent molecular techniques and procedures and lend perspective to how each has enhanced the current understanding of this organism and will emphasize how Next Generation Sequencing may serve as a resource for researchers to gain a more comprehensive understanding of the genomic complexities of this insidious pathogen.

Mycoplasma pneumoniae Epidemiology in England and Wales: A National Perspective

Investigations of patients with suspected Mycoplasma pneumoniae infection have been undertaken in England since the early 1970s. M. pneumoniae is a respiratory pathogen that is a common cause of pneumonia and may cause serious sequelae such as encephalitis and has been documented in children with persistent cough. The pathogen is found in all age groups, with higher prevalence in children aged 5–14 years. In England, recurrent epidemic periods have occurred at ~4-yearly intervals. In addition, low-level sporadic infection occurs with seasonal peaks from December to February. Voluntarily reports from regional laboratories and hospitals in England from 1975 to 2015 were collated by Public Health England for epidemiological analysis. Further data pertaining cases of note and specimens submitted to Public Health England from 2005 to 2015 for confirmation, molecular typing is included.

Classification of Extrapulmonary Manifestations Due to Mycoplasma pneumoniae Infection on the Basis of Possible Pathogenesis

The list of extrapulmonary manifestations due to Mycoplasma pneumoniae infection can be classified according to the following three possible mechanisms derived from the established biological activity of M. pneumoniae; (1) a direct type in which the bacterium is present at the site of inflammation and local inflammatory cytokines induced by the bacterium play an important role (2) an indirect type in which the bacterium is not present at the site of inflammation and immune modulations, such as autoimmunity or formation of immune complexes, play an important role, and (3) a vascular occlusion type in which obstruction of blood flow induced either directly or indirectly by the bacterium plays an important role. Recent studies concerning extrapulmonary manifestations have prompted the author to upgrade the list, including cardiac and aortic thrombi as cardiovascular manifestations; erythema nodosum, cutaneous leukocytoclastic vasculitis, and subcorneal pustular dermatosis as dermatological manifestations; acute cerebellar ataxia, opsoclonus-myoclonus syndrome, and thalamic necrosis as neurological manifestations; pulmonary embolism as a respiratory system manifestation; and renal artery embolism as a urogenital tract manifestation. Continuing nosological confusion on M. pneumoniae–induced mucositis (without skin lesions), which may be called M. pneumoniae-associated mucositis or M. pneumoniae-induced rash and mucositis separately from Stevens-Johnson syndrome, is argued in the dermatological manifestations. Serological methods are recommended for diagnosis because pneumonia or respiratory symptoms are often minimal or even absent in extrapulmonary manifestations due to M. pneumoniae infection. Concomitant use of immunomodulators, such as corticosteroids or immunoglobulins with antibiotics effective against M. pneumoniae, can be considered as treatment modalities for most severe cases, such as encephalitis. Further studies would be necessary to construct a comprehensive therapeutic strategy, covering microbiology (antibiotics), immunology (immunomodulators), and hematology (anticoagulants). The possible influence of the emergence of macrolide-resistant M. pneumoniae on extrapulmonary manifestations, which can be considered of limited clinical threat in Japan where the resistant rate has currently decreased, is discussed on the basis of unique biological characteristics of M. pneumoniae, the smallest self-replicating organism.

Incidence, causative factors and mortality rates of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in northern Italy: data from the REACT registry

PURPOSE

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe cutaneous adverse drug reactions. We assessed incidence, drug exposure and mortality, analysing data obtained from the Lombardy Registry of Severe Cutaneous Reactions (REACT).

METHODS

Data were collected from hospitals in the Italian Lombardy region (9,502,272 people). A trained monitor was sent to the reporting hospital to collect data on drug exposure and clinical features. The algorithm for drug causality for epidermal necrolysis algorithm was applied to assess drug causality. Defined Daily Dose (DDD) was used to express drug consumption.

RESULTS

From April 2009 to November 2014, 17 cases of TEN and 59 cases of SJS were collected. The overall incidence rate was 1.40 cases (95%CI, 1.12-1.76) per million people per year. A total of 15 cases died during hospitalization with a mortality rate of 16.9% for SJS and 29.4% for TEN. Overall, 55.4% of cases had a probable or very probable relation with drug exposure. In a total of five patients (6.6%), no causative drug for the reaction was identifiable. Allopurinol contributed to the highest number of cases (23 cases), while the highest incidence based on more than one case reported was observed for cotrimoxazole and lamotrigine, with 5.37 cases (95%CI, 2.09-13.80) and 3.54 (95%CI, 1.21-10.42) per 10 million DDD/year, respectively.

CONCLUSIONS

We confirmed that SJS and TEN are rare adverse cutaneous reactions. As expected, mortality was influenced by the degree of skin detachment. The profile of drugs associated with the reactions was in agreement with data from other surveillance systems.