Macrolide resistance of Mycoplasma pneumoniae, South Korea, 2000-2011

The Clinical Significance of Pathogen Loads and Macrolide Resistance Levels for Macrolide-Resistant Mycoplasma pneumoniae Pneumonia in Children

Objective

Mycoplasma pneumoniae (M. pneumoniae) pneumonia presses a serious threat on children's health. This study was aimed to investigate the clinical significance of pathogen loads and macrolide resistance levels for macrolide-resistant M. pneumoniae (MRMP)-induced pneumonia in children.

Methods

Serum levels of inflammatory markers including lactic dehydrogenase (LDH), D-dimer, C-reactive protein (CRP) were tested. RT‒PCR was used for the detection of M. pneumoniae infection and the macrolide resistance levels. The patients were classified into high pathogen load and low pathogen load groups based on the Ct values of the p1 gene, and high macrolide resistance level and low macrolide resistance level groups based on the relative levels of macrolide resistance associated mutations to that of the p1 gene. The rates of alternative antibiotic use and hospitalization days were recorded, and the leukocyte counts were tested.

Results

The rates of elevated inflammatory markers from high to low were LDH, CRP and D-dimer. The Ct values of the p1 gene ranged from 19 to 35, and patients with higher pathogen loads had greater rates of alternative antibiotic use; higher levels of LDH, D-dimer, CRP and neutrophil counts (NEUT); and longer hospitalization durations. The range of the macrolide resistance levels was 0.31-2.11, and the rates of alternative antibiotic use, NEUT, CRP and D-dimer levels were higher in patients with higher macrolide resistance levels.

Conclusion

LDH was a more frequently elevated serum inflammatory marker than D-dimer and CRP, and the pathogen load and macrolide resistance levels possessed important clinical significance for MRMP-induced pneumonia in children.

Treatment of Macrolide-resistant Mycoplasma pneumoniae Pneumonia in Children: A Meta-analysis of Macrolides Versus Tetracyclines

BACKGROUND

The global prevalence of macrolide-resistant Mycoplasma pneumoniae (MRMP) pneumonia infections, particularly in children, is on the rise. It is imperative to assess the clinical efficacies of alternative antibiotics such as tetracyclines to ensure effective treatment, mitigate antibiotic resistance, enhance clinical outcomes, and minimize the spread of resistant strains among MRMP-infected children. The objective of this study was to compare the therapeutic efficacies of macrolides and tetracyclines in treating MRMP pneumonia in children.

METHODS

We systematically searched the literature to identify comparative studies that examined the clinical outcomes of macrolide and tetracycline antibiotics in children with MRMP pneumonia. We conducted a meta-analysis of the mean duration of fever, hospital stay duration, therapeutic efficacies, and time to defervescence to compare macrolides and tetracyclines.

RESULTS

Eleven studies involving 1143 patients compared the clinical efficacies of macrolides and tetracyclines in children with MRMP pneumonia. The studies were conducted in China, Japan, and Korea, and the outcomes of febrile days, hospital stay duration, therapeutic efficacy, and time to defervescence were analyzed. The macrolides studied were azithromycin and clarithromycin, whereas the tetracyclines included minocycline and doxycycline. The pooled estimate of 5 studies showed that the mean duration of febrile days and hospital stay was longer in the macrolides group than tetracycline group [weighted mean difference = 1.64 days, 95% confidence interval (CI): 0.68-2.59, weighted mean difference = 1.22 days, 95% CI: 0.82-1.62, respectively]. The therapeutic efficacy was significantly lower in the macrolide group than in the tetracycline group (odds ratio: 0.33, 95% CI: 0.20-0.57).

CONCLUSIONS

The clinical efficacy of tetracycline treatment was superior to that of macrolide treatment in children with MRMP pneumonia. However, further research is required to validate these findings and inform evidence-based clinical practice guidelines.

Association of serum interleukin-17 level and Mycoplasma pneumoniae pneumonia in children: a systematic review and meta-analysis

Background

Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen of community-acquired pneumonia. Interleukin-17 (IL-17) plays a role in host defense and contributes to disease severity in infection. This present study aims to investigate the association between Mycoplasma pneumoniae pneumonia (MPP) and changes of IL-17 level in the serum of pediatric patients.

Methods

The protocol has been registered in PROSPERO (CRD42023489451). A literature search was conducted in PubMed, EMBASE, Scopus, and Web of Science from inception to October 2023. A meta-analysis was performed to pool the mean difference (MD) with 95% confidence intervals (CIs) of IL-17 levels between patients and controls. Publication bias was assessed, and the risk of bias was evaluated using the Newcastle-Ottawa Scale (NOS).

Results

Out of 207 records, 10 studies were included in the review and 9 studies were included in the meta-analysis. Of these, 7 studies compared IL-17 in general MPP patients with controls, 6 studies compared severe MPP patients with mild MPP patients. Serum IL-17 levels were significantly elevated in general MPP patients compared with control (MD =33.94 pg/mL, 95% CI: 24.66, 43.22 pg/mL, P=0.01, I2=99.07%; P=0.01). Subgroup analyses showed a difference in serum IL-17 levels treated by macrolide between patients and control (MD =83.96 pg/mL, 95% CI: 76.62, 91.29 pg/mL, P=0.01). In severe and mild MPP, the IL-17 levels were significantly increased (MD =19.08 pg/mL, 95% CI: 11.51, 26.65 pg/mL, P=0.01) and heterogeneity was appeared (I2=99.39%; P=0.01). For the risks of bias, two studies had a "high risk" in comparability domain, and the 7 studies were classified as "low risk" and "unclear risk".

Conclusions

Our meta-analysis revealed that serum IL-17 levels are significantly elevated in pediatric with general and severe MPP. IL-17 might be a potential biomarker or therapeutic target for pneumonia caused by M. pneumoniae.

The efficacy of azithromycin combined with seven types of Chinese medicine injections in the treatment of Mycoplasma pneumoniae pneumonia in children: a systematic review and Bayesian network meta-analysis

Mycoplasma pneumoniae pneumonia (MPP) is the predominant community-acquired pneumonia (CAP) in children aged 5 years or older. In recent decades, the annual increase in drug resistance rates of macrolide antibiotics, particularly azithromycin (AZ), has led to complex clinical treatment strategies and substantial healthcare costs associated with MPP. Chinese medicine injections (CMIs), recognized as an effective supplementary therapy, are acknowledged by clinicians in China. It is necessary to explore the efficacy of azithromycin in combination with CMIs.

Methods

Randomized controlled trials (RCTs) evaluating azithromycin in combination with seven types of CMIs for MPP in children were identified based on inclusion criteria and assessed using the revised Cochrane risk of bias tool (RoB 2.0). R 4.3.1 and STATA 15.0 were employed to generate ranking probabilities and perform network meta-analysis. Competing interventions were ranked using the surface under the cumulative ranking (SUCRA) probabilities.

Results

A comprehensive analysis was performed on 155 RCTs involving 15,014 patients and 8 therapeutic strategies within this Bayesian network meta-analysis (BNMA). The results indicated that AZ combined with seven types of CMIs was more effective than azithromycin alone in overall outcomes. Notably, azithromycin combined with Chuanhuning injection (AZ + CHN) achieved the highest ranking in improving the clinical effectiveness rate (SUCRA, 80.89%); regarding secondary outcome measures, azithromycin combined with Yanhuning injection (AZ + YHN) had the highest probability of improving four different outcomes: disappearance time of cough (SUCRA, 80.01%), disappearance time of pulmonary rale (SUCRA, 87.77%), disappearance time of fever (SUCRA, 95.70%), and disappearance time of pulmonary shadows in X-ray (SUCRA, 97.34%); furthermore, azithromycin combined with Qingkailing injection (AZ + QKL) was more likely to reduce average hospitalization time (SUCRA, 94.60%).

Conclusion

This study highlights the potential benefits of seven types of Chinese medicine injections as adjunctive therapy for Mycoplasma pneumoniae pneumonia in children. However, further support and validation of these findings are needed through high-quality randomized controlled trials with larger sample sizes and double-blind designs.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails/.

Clinical Manifestations, Macrolide Resistance, and Treatment Utilization Trends of Mycoplasma pneumoniae Pneumonia in Children and Adolescents in South Korea

A resurgence of Mycoplasma pneumoniae (MP)-the leading cause of community-acquired bacterial pneumonia, particularly in children-occurred following the COVID-19 pandemic. We aimed to investigate the clinical manifestations, macrolide resistance patterns, and therapeutic approaches related to the MP pneumonia epidemic. Children and adolescents diagnosed with MP pneumonia in September-December 2023 were screened. Clinical data were retrospectively collected from 13 major hospitals using concordant microbiological criteria, including either a positive PCR result or four-fold increase in serological markers. Demographic characteristics, treatment modalities, and clinical outcomes were analyzed. Of the 474 screened patients, 374 (median age: 7.7 [IQR, 5.4-9.6] years; hospitalization rate: 88.6%) met the microbiological confirmation criteria. Most patients experienced fever (98.9%), and lobular/lobar consolidation (59.1%) was the dominant radiological finding. The macrolide resistance rate remained high at 87.0%; corticosteroids were widely used (55.6%) alongside macrolides, despite resistance. Patients with consolidation had prolonged fever (median 8 vs. 7 days, p = 0.020) and higher hospitalization rates (92.3% vs. 83.0%, p = 0.008). Macrolide resistance did not significantly influence radiological outcomes. This study highlights the ongoing challenge of macrolide resistance in MP pneumonia and need for tailored therapeutic approaches. Despite high resistance, macrolides remain commonly prescribed, often concurrently with corticosteroids.

Macrolide-resistant mycoplasma pneumoniae infection in children observed during a period of high incidence in Henan, China

Objective

Mycoplasma pneumoniae (Mp) is one of the major pathogens that causes respiratory tract infections, and macrolide resistance has increased rapidly in recent years due to the inappropriate use of macrolides in northeastern Asia. In the present study, we aimed to investigate Mp infection and macrolide resistance during a period of high incidence of Mp infection in Henan, China.

Methods

A total of 29473 suspected children with Mp infection were enrolled in the study from July to December 2023. Throat swab specimens were collected from all the study subjects, and real-time PCR was performed to detect the Mp-DNA and macrolide resistance-associated A2063G or A2064G mutations.

Results

The overall percentage of Mp-DNA-positive patients was 51.1 %, and the percentage of macrolide-resistant strains was 91 %. The rate of macrolide resistance remained stable from July to December. The Mp-DNA positivity rates among the different age groups from low to high were 0-1, 1-3, 3-6, 10-18 and 6-10 years. The macrolide resistance rate was the lowest in the 0-1 age group and highest in the 6-10 age group. No difference in the rate of macrolide resistance was observed between male and female children.

Conclusions

The macrolide resistance rate of Mp did not change during the investigated period of high incidence of infection, and no sex difference existed. The macrolide resistance rate of Mp was the lowest in children under 1 year old.

Challenges in the treatment of pediatric Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is an important cause of community-acquired pneumonia in children and young adolescents. Despite macrolide antibiotics effectiveness as a first-line therapy, persistence of fever and/or clinical deterioration sometimes may complicate treatment and may even lead to severe systemic disease. To date, there is no consensus on alternative treatment options, optimal dosage, and duration for treating severe, progressive, and systemic MP pneumonia after macrolide treatment failure. Macrolide-resistant MP pneumonia and refractory MP pneumonia are the two major complex conditions that are clinically encountered. Currently, the vast majority of MP isolates are resistant to macrolides in East Asia, especially China, whereas in Europe and North America, whereas in Europe and North America prevalence is substantially lower than in Asia, varying across countries. The severity of pneumonia and extrapulmonary presentations may reflect the intensity of the host's immune reaction or the dissemination of bacterial infection. Children infected with macrolide-resistant MP strains who receive macrolide treatment experience persistent fever with extended antibiotic therapy and minimal decrease in MP-DNA load. Alternative second-line agents such as tetracyclines (doxycycline or minocycline) and fluoroquinolones (ciprofloxacin or levofloxacin) may lead to clinical improvement after macrolide treatment failure in children. Refractory MP pneumonia reflects a deterioration of clinical and radiological findings due to excessive immune response against the infection. Immunomodulators such as corticosteroids and intravenous immunoglobulin (IVIG) have shown promising results in treatment of refractory MP pneumonia, particularly when combined with appropriate antimicrobials. Corticosteroid-resistant hyperinflammatory MP pneumonia represents a persistent or recrudescent fever despite corticosteroid therapy with intravenous methylprednisolone at standard dosage.

CONCLUSION

 This report summarizes the clinical significance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drugs, with a stepwise approach to the management of MP pneumonia recommended from the viewpoint of clinical practice.

WHAT IS KNOWN

• Although MP pneumonia is usually a benign self-limited infection with response macrolides as first line therapy, severe life-threatening cases may develop if additional treatment strategies are not effectively implemented. • Macrolide-resistant and refractory MP pneumonia are two conditions that may complicate the clinical course of MP pneumonia, increasing the risk for exacerbation and even death.

WHAT IS NEW

• This report summarizes the clinical relevance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drug therapies. • A practical stepwise approach to the management of MP pneumonia is developed based on a comprehensive analysis of existing evidence and expert opinion.

Antibiotics for Pediatric Patients With Laryngotracheobronchitis in Korea: A Nationwide Study Based on Administrative Data

BACKGROUND

Antimicrobial resistance (AMR) is an important global public health concern in adults and children. Laryngotracheobronchitis (croup) is a common acute respiratory infection (ARI) among children, most often caused by a virus, and should not be treated with antibiotics. Reducing the usage of unnecessary antibiotics in ARI using an antimicrobial stewardship program (ASP) is an effective measure against AMR in children. This study investigates the antibiotic prescription pattern in pediatric patients with laryngotracheobronchitis in Korea. Our results will be useful to improve the ASP.

METHODS

The data were obtained from the government agency Health Insurance Review and Assessment Service. We analyzed outpatient prescriptions issued to children ≤ 5 years of age with a first-listed diagnosis code for laryngotracheobronchitis, i.e., International Classification of Disease, 10th Revision, code J050 (croup), J040 (laryngitis), or J041 (tracheitis), during 2017-2020. For each prescription, demographic information and information about medical facilities visited (type of hospital, specialty of physician, location of hospital) were extracted. The overall antibiotic prescription rate was subsequently estimated, and multivariable analysis was conducted to determine the associated factors of antibiotic prescription. Prescribed antibiotics were described and classified into extended-spectrum penicillins, cephalosporin, and macrolides.

RESULTS

Of 2,358,194 prescriptions reviewed, 829,172 (35.2%) contained antibiotics. In the multivariable analysis, management in a hospital was the strongest factor associated with antibiotic prescription (adjusted odds ratio [aOR], 22.33; 95% confidence interval [CI], 20.87-23.89; P < 0.001), followed by management in a clinic (aOR, 12.66; 95% CI, 11.83-13.54; P < 0.001) and management in a general hospital (aOR, 8.96; 95% CI, 8.37-9.59; P < 0.001). Antibiotic prescription was also significantly associated with patients who were ≤ 2 years of age, managed by a pediatric specialist, and treated at a hospital located in a non-metropolitan region. Overall, extended-spectrum penicillins were the most frequently prescribed (18.6%) antibiotics, followed by cephalosporins (9.4%) and macrolides (8.5%).

CONCLUSION

The results of our study suggest that ASPs need to focus on physicians in hospitals, clinics, general hospitals, and pediatric specialties. Providing education programs to these groups to increase awareness of AMR and appropriate antibiotics use could be effective ASP policy and may help to reduce unnecessary prescriptions of antibiotics for laryngotracheobronchitis among pediatric patients and therefore potentially AMR in children in Korea.

Necrotizing pneumonia associated with macrolide-resistant Mycoplasma in a child

We reported a pediatric case of necrotizing pneumonia due to macrolide-resistant Mycoplasma pneumoniae, an uncommon presentation of a common disease. Acquisition of resistance does not increase virulence, but it leads to more difficult treatment and potential complications. Macrolide-resistant M. pneumoniae requires extended antibiotic therapy with the addition of a second-line agent and an immunomodulator to promote clinical improvement with minimal sequelae.

Identification of mycoplasma pneumonia in children based on fusion of multi-modal clinical free-text description and structured test data

Mycoplasma pneumonia may lead to hospitalizations and pose life-threatening risks in children. The automated identification of mycoplasma pneumonia from electronic medical records holds significant potential for improving the efficiency of hospital resource allocation. In this study, we proposed a novel method for identifying mycoplasma pneumonia by integrating multi-modal features derived from both free-text descriptions and structured test data in electronic medical records. Our approach begins with the extraction of free-text and structured data from clinical records through a systematic preprocessing pipeline. Subsequently, we employ a pre-trained transformer language model to extract features from the free-text, while multiple additive regression trees are used to transform features from the structured data. An attention-based fusion mechanism is then applied to integrate these multi-modal features for effective classification. We validated our method using clinic records of 7157 patients, retrospectively collected for training and testing purposes. The experimental results demonstrate that our proposed multi-modal fusion approach achieves significant improvements over other methods across four key performance metrics.

The molecular characteristics, diagnosis, and treatment of macrolide-resistant Mycoplasma pneumoniae in children

The purpose of this study is to review the molecular characteristics, the diagnosis, and treatment of the widespread infection of macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae; MRMP) in children, thus providing a better knowledge of this infection and presenting the associated problems. Single point mutations in the V region of the 23S rRNA gene of M. pneumoniae genome are associated with macrolide resistance. P1-1, MLVA4-5-7-2, and ST3 are usually the predominated genetic types in the M. pneumoniae epidemics. The short-term two times serological IgM (or together with IgG) test in the acute stage can be used for confirmation. Combined serological testing and PCR might be a more prudent method to reduce macrolide consumption and antibiotic selective pressure in a clinical setting. Molecular methods for the detection of single-nucleotide mutations in the V region of the 23S rRNA gene can be used for the diagnosis of MRMP. The routine use of macrolide for the treatment of macrolide-sensitive Mycoplasma pneumoniae (MSMP) infections can get good effect, but the effects are limited for severe MRMP infections. Additional corticosteroids may be required for the treatment of severe MRMP infections in children in China during the era of MRMP.

Epidemiology and surveillance implications of community-acquired pneumonia in children

Community-acquired pneumonia (CAP) is the single largest infectious cause of hospitalization and death in children worldwide. With improved immunizations, the incidence of bacterial pneumonia and the number of colonized bacteria have decreased. However, respiratory viruses are still an important cause of CAP, especially as new infectious agents such severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge. The SARS-CoV-2 virus emerged in 2019 and caused the current coronavirus disease 2019 pandemic. Therefore, it is necessary to elucidate the epidemiology and causative pathogens of CAP. Recently, the Pneumonia and Respiratory Disease Study Group, affiliated with the Korean Academy of Pediatric Allergy and Respiratory Disease, investigated the causative pathogens of respiratory infections in children hospitalized with CAP, the serotype of Streptococcus pneumoniae, and the prevalence of Mycoplasma pneumoniae with gene mutations. Antibiotic resistance and serotype test results can determine the use of empirical antibiotics. Moreover, it is possible to help develop future vaccines by comparing bacterial culture results with vaccine serotype and identifying the changes and prevalence of each serotype. Therefore, we will perform continuous national surveillance and monitor the epidemiology of respiratory pathogens in Korea and worldwide. The surveillance of these respiratory infections can play a role in monitoring the emergence of new infectious diseases such as SARS-CoV-2.

Assessment of variables associated with prolonged admission duration in children with Mycoplasma pneumoniae pneumonia

Introduction

Macrolide‐resistant Mycoplasma pneumoniae (MRMP) has become prevalent in children. This study investigated the clinical and laboratory variables of MRMP and macrolide‐sensitive M. pneumoniae (MSMP) and identified factors associated with prolonged hospital admission in children.

Methods

A prospective multicenter study was conducted in 1063 children <18 years old in July 2018–June 2020. The 454 had a positive M. pneumoniae polymerase chain reaction assay.

Results

Most subjects had MRMP (78.4%), and all mutated strains had the A2063G transition. We defined MRMP* (n = 285) as MRMP pneumonia requiring admission and MSMP* (n = 72) as MSMP pneumonia requiring admission. Patients with MRMP pneumonia were older, more likely to have segmental/lobar pneumonia, and had more febrile days than those with MSMP pneumonia. C‐reactive protein (CRP), lactate dehydrogenase (LDH), and percentage neutrophils were more strongly associated with MRMP* than MSMP* groups. Percentage neutrophils, CRP, and alanine aminotransferase significantly changed between admission and follow‐up measurements in patients with MRMP* (P < 0.05). The duration of admission positively correlated with the number of febrile days after initiation of antibiotic medication and laboratory variables (white blood cell count, CRP, and aspartate aminotransferase [AST]) (P < 0.05). Random forest analysis indicated that the number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission was over five.

Conclusions

This study indicated that children with M. pneumoniae pneumonia with a higher number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission were more likely to have prolonged admission duration.

Macrolide versus Non-Macrolide in Combination with Steroids for the Treatment of Lobar or Segmental Mycoplasma pneumoniae Pneumonia Unresponsive to Initial Macrolide Monotherapy

In the last few decades, macrolide-resistant Mycoplasma pneumoniae (MRMP) has been increasing in proportion. This study aimed to evaluate the treatment outcomes of children with lobar or segmental MP pneumonia unresponsive to the initial 3−5-day macrolide therapy, who then switched to either a non-macrolide, macrolide + steroid, or a non-macrolide + steroid regimen, according to the 2019 KSPID and KAPARD guideline during the 2019−2020 Mycoplasma epidemic in South Korea. A total of 190 patients <18 years old were admitted during the study period for MP lobar or segmental pneumonia, and 16.8% (n = 32/190) were responsive to the initial macrolide monotherapy, whereas 83.2% (158/190) were refractory. The median age of the patients was 7 (interquartile range [IQR], 5−9) years old and 46.2% (n = 73/158) were male. The overall treatment success rates of non-macrolide, macrolide + steroid, and non-macrolide + steroid groups were 46.2%, 80.8%, and 100.0%, respectively. Patients in the non-macrolide + steroid group had the shortest fever duration after a regimen change of 1 (IQR, 0−3) day compared with patients in the non-macrolide group and macrolide + steroid group; 2 (IQR, 1−4) days and 2 (IQR, 1−3.3) days (p = 0.004), respectively. Follow-up CRP (ß, 0.169; CI, 0.050−0.287; p = 0.006), macrolide + steroid therapy (ß, −1.694; CI, −2.463−−0.925; p < 0.001), and non-macrolide+ steroid therapy (ß, −2.224; CI, −3.321−−1.127; p < 0.001) were shown to be significantly associated with the duration of fever after admission. To conclude, in patients with severe MP pneumonia that failed to respond to the initial macrolide therapy, a non-macrolide + steroid had the highest treatment success rate and a shorter duration of fever.

Global prevalence of resistance to macrolides in Mycoplasma pneumoniae: a systematic review and meta-analysis

OBJECTIVES

To determine the prevalence of resistance to macrolides in Mycoplasma pneumoniae worldwide.

METHODS

Prior to 12 December 2020, PubMed, Web of Science, Scopus and Embase databases were searched for epidemiological studies of M. pneumoniae resistance. Two reviewers independently extracted data from included studies. The extracted data include sampling population, total sampling number, the number of resistant strains and the molecular subtype of resistant strains. The estimate of resistance prevalence was calculated using the random-effects model.

RESULTS

A total of 17 873 strains were obtained from five continents and reported in 98 investigations between 2000 and 2020, with 8836 strains characterized as macrolide resistant. In summary, macrolide-resistant M. pneumoniae was most common in Asia (63% [95% CI 56, 69]). In Europe, North America, South America and Oceania, the prevalence was 3% [2, 7], 8.6% [6, 11], 0% and 3.3%, respectively. Over the last 20 years, the prevalence of macrolide-resistant M. pneumoniae has remained high in China (81% [73, 87]), with a significant increasing trend in South Korea (4% [1, 9] to 78% [49, 93], P < 0.0001). Furthermore, a point mutation at 2063 from A to G was mostly related to M. pneumoniae macrolide resistance. In terms of clinical outcomes, longer cough (mean difference [MD]: 2.93 [0.26, 5.60]) and febrile days (MD: 1.52 [1.12, 1.92]), and prolonged hospital stays (MD: 0.76 [0.05, 1.46]) might be induced by macrolide-resistant M. pneumoniae pneumonia.

CONCLUSIONS

The incidence of macrolide-resistant M. pneumoniae varies globally, with eastern Asia having a greater degree of resistance. However, attention is also required in other areas, and antibiotic alternatives should be considered for treatment in high-prevalence countries.

Association between bronchopulmonary dysplasia and early respiratory morbidity in children with respiratory distress syndrome: a case-control study using nationwide data

Bronchopulmonary dysplasia (BPD) can cause respiratory morbidity beyond the neonatal period. We aimed to analyze the association of BPD on childhood lower respiratory illness (LRI) and asthma among patients diagnosed with respiratory distress syndrome (RDS). This case–control study analyzed data between 2002 and 2015 from a nationwide database. We included 55,066 children with RDS. Two-year LRI and asthma at ages 3 and 5 were assessed. Readmission for LRIs within 2 years of birth occurred in 53.9% and 37.9% of the BPD (n = 9470) and non-BPD (n = 45,596) cases, respectively. In the BPD group, the median number of hospitalizations, mechanical ventilation and oxygen use rates were significantly higher, while the hospitalization duration was significantly longer (P < 0.001 for all). The relative risk of BPD was 1.42 (1.39–1.45) on total readmission and 6.53 (5.96–7.15) on intensive care unit readmission. Asthma prevalence was significantly higher in BPD group (57.6% vs. 48.9% at age 3 and 44.3% vs. 38.2% at age 5, P < 0.001). In children with RDS, BPD could affect repetitive and worse LRI as an independent risk factor for respiratory morbidity during the first 2 years of life. BPD may also be a crucial risk factor for asthma in preschoolers.

Association of Tandem Repeat Number Variabilities in Subunit S of the Type I Restriction-Modification System with Macrolide Resistance in Mycoplasma pneumoniae

Mycoplasma pneumoniae is one of the major pathogens responsible for pneumonia in children. Modern molecular genetics has advanced both the management and the epidemiologic study of this disease. Despite these advancements, macrolide resistance remains a global threat in the management of M. pneumoniae infection, for which the genetic background remains unrevealed. In this study, the result of whole genome analysis of 20 sequence type 3 (ST3) M. pneumoniae strains were examined to investigate the gene(s) associated with macrolide resistance. Overall, genetic similarities within M. pneumoniae, and especially ST3, were very high (over 99.99 %). Macrolide resistant ST3 strains shared 20 single nucleotide polymorphisms, of which one gene (mpn085) was found to be associated with resistance. BLAST comparison of M. pneumoniae revealed regular tandem repeat number variabilities between macrolide-susceptible and resistant strains for genes coding the Type I restriction-modification (R-M) system of subunit S (HsdS). Of the ten known HsdS genes, macrolide resistance was determined by the unique tandem repeat of mpn085 and mpn285. In conclusion, the use of whole genome sequencing (WGS) to target macrolide resistance in M. pneumoniae indicates that the determinant of macrolide resistance is variabilities in the tandem repeat numbers of the type I R-M system in subunit S.

Genotype and mutation patterns of macrolide resistance genes of Mycoplasma pneumoniae from children with pneumonia in Qingdao, China, in 2019

OBJECTIVES

This study assessed the incidence and resistance of Mycoplasma pneumoniae (MP) in children in Qingdao, China, in 2019.

METHODS

We detected MP infection in 78 pharyngeal swabs from children with pneumonia by qPCR. The RepMP4 element in the P1 adhesin gene, domain V of the 23S rRNA gene, and the L4/L22 ribosomal proteins were amplified by nested PCR. Evolutionary analysis was conducted based on the P1 gene sequence. Resistance mutations in domain V of the 23S rRNA gene and L4/L22 ribosomal proteins were analysed.

RESULTS

The incidence of MP infection in children with pneumonia was 59.0% (46/78). The mean duration of MP infection was longer than that of non-MP infection. According to P1 gene sequencing of 21 samples, 12 (57.1%) were type 1 and 9 (42.9%) were type 2. Drug resistance mutations A2063G in domain V of 23S rRNA gene and T508C in L22 were identified from all sequenced MP. However, mutations at positions 2064 and 2617 were not found in this study. C162A mutation appeared in most type 2 samples. A430G mutation appeared in one type 1 sample and in several type 2 samples. T279C mutation in L22 was mostly found in type 2 samples.

CONCLUSION

The incidence of MP infection was 59.0% in children with pneumonia in Qingdao in 2019. Type 1 MP infection was slightly more common than type 2, indicating that the genotype of MP is gradually shifting from type 1 to type 2. Macrolide resistance mutation A2063G could be detected in all sequenced MP.

Persistent high macrolide resistance rate and increase of macrolide-resistant ST14 strains among Mycoplasma pneumoniae in South Korea, 2019-2020

BACKGROUND

Expansion of the single sequence type 3 (ST3) was associated with a high macrolide resistance rate among Mycoplasma pneumoniae in Korea during the 2014-2016 epidemic. This study investigates the macrolide resistance rate and genetic diversity of the subsequent epidemic of M. pneumoniae pneumonia in 2019-2020.

METHODS

The culture for M. pneumoniae was developed from 1228 respiratory samples collected from children with pneumonia in four hospitals in Korea between January 2019 and January 2020. Determination of macrolide resistance and multilocus sequence typing analysis were performed on M. pneumoniae isolates. eBURST analysis was applied to estimate the relationships among strains and to assign strains to a clonal complex.

RESULTS

M. pneumoniae was cultured in 93 (7.6%) of 1228 clinical samples. The overall macrolide resistance rate of M. pneumoniae strains was 78.5% (73/93). Of the nine STs identified, three were novel. The most common ST was ST3 (66 [71.0%]) followed by ST14 (18 [19.4%]) and ST7/ST15 (2 [2.2%] each). Three STs (ST3, ST14, and ST17) exhibited macrolide resistance. The macrolide resistance rates of ST3 and ST14 were 98.5% (65 of 66) and 38.9% (7 of 18), respectively.

CONCLUSION

Compared to the previous outbreak in 2014-2016, the overall macrolide resistance remained high; however, an increasing proportion of macrolide resistance was observed within ST14 strains in 2019-2020.

Prediction model for prolonged fever in patients with Mycoplasma pneumoniae pneumonia: a retrospective study of 716 pediatric patients

Objective

To identify patients with Mycoplasma pneumoniae pneumonia (MPP) with a risk of prolonged fever while on macrolides.

Methods

A retrospective study was performed with 716 children admitted for MPP. Refractory MPP (RMPP-3) was defined as fever persisting for > 72 h without improvement in clinical and radiologic findings after macrolide antibiotics (RMPP-3) or when fever persisted for > 120 h (RMPP-5) without improvement in clinical and radiologic findings. Radiological data, laboratory data, and fever profiles were compared between the RMPP and non-RMPP groups. Fever profiles included the highest temperature, lowest temperature, and frequency of fever. Prediction models for RMPP were created using the logistic regression method and deep neural network. Their predictive values were compared using receiver operating characteristic curves.

Results

Overall, 716 patients were randomly divided into two groups: training and test cohorts for both RMPP-3 and RMPP-5. For the prediction of RMPP-3, a conventional logistic model with radiologic grouping showed increased sensitivity (63.3%) than the model using laboratory values. Adding laboratory values in the prediction model using radiologic grouping did not contribute to a meaningful increase in sensitivity (64.6%). For the prediction of RMPP-5, laboratory values or radiologic grouping showed lower sensitivities ranging from 12.9 to 16.1%. However, prediction models using predefined fever profiles showed significantly increased sensitivity for predicting RMPP-5, and neural network models using 12 sequential fever data showed a greatly increased sensitivity (64.5%).

Conclusion

RMPP-5 could not be effectively predicted using initial laboratory and radiologic data, which were previously reported to be predictive. Further studies using advanced mathematical models, based on large-sized easily accessible clinical data, are anticipated for predicting RMPP.

A multisite SNP genotyping and macrolide susceptibility gene method for Mycoplasma pneumoniae based on MALDI-TOF MS

In this study, a multisite SNP genotyping and macrolide (ML) susceptibility gene test method for Mycoplasma pneumoniae (M. pneumoniae) was developed based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The detection limit of this method for nucleic acids was 10² -10³ copies/reaction. Six SNP site-based genotyping and 3 ML susceptibility sites could be detected simultaneously based on multiplex PCR and mass probe. Using the method constructed in this study, 141 Chinese clinical isolates were divided into 8 SNP types. All the SNP test results for the ML susceptibility gene were in line with those of the 23S rRNA sequencing results. With this method, the multisite SNP genotyping and ML susceptibility determination of M. pneumoniae can be completed simultaneously in one test, which greatly reduces the workload and cost, improves the genotyping ability of M. pneumoniae and deserves clinical application.

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An all-in-one genotyping and macrolide resistance testing method for M. pneumoniae

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Multisite SNP detection technology was used for genotyping and resistance testing

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The cost of M. pneumoniae genotyping and macrolide resistance detection was reduced

Clinical efficacy enhancement of a Chinese herbal injection in the treatment of mycoplasma pneumonia in children: A protocol of randomized controlled trial

BACKGROUND

Mycoplasma pneumonia is a common disease in pediatrics, and macrolides is the first choice for the treatment. However, the increase of antibiotic resistance of macrolides makes it more and more complicated for clinical treatment. Due to the long term treatment of macrolides, it may increase the incidence of nausea, vomiting, abdominal pain, diarrhea, and other gastrointestinal symptoms, vascular phlebitis, liver and kidney function damage. Tanreqing injection, a Chinese herbal extraction injection, has advantages in the treatment of mycoplasma pneumonia in children, and it could improve the curative effect, shortening the course of disease, and reducing the side effects. Yet there is a lack of standard clinical studies to verify it, so this randomized controlled trial (RCT) will evaluate the efficacy and safety of Tanreqing injection combined with azithromycin in the treatment of mycoplasma pneumonia in children.

METHODS

This is a prospective RCT to study the efficacy and safety of Tanreqing injection combined with azithromycin in the treatment of mycoplasma pneumonia in children. It is approved by the Clinical Research Society of our hospital. According to the 1:1 ratio, the patients will be randomly divided into Tanreqing injection combined with azithromycin group (observation group) and azithromycin group (control group). Duration of hospitalization, clinical improvement 7 days after admission, changing laboratory tests, pulmonary function, immunoglobulin level, and adverse reactions will be compared between the 2 groups. The data will be analyzed by SPSS 16.0 software.

DISCUSSION

This study will evaluate the efficacy and safety of Tanreqing injection combined with azithromycin in the treatment of mycoplasma pneumonia in children. The results of this experiment will provide clinical basis for the treatment of mycoplasma pneumonia in children with Tanreqing injection combined with azithromycin.

TRIAL REGISTRATION

OSF Registration number: DOI 10.17605/OSF.IO/X6VFS.

Macrolide-Resistant and Macrolide-Sensitive Mycoplasma pneumoniae Pneumonia in Children Treated Using Early Corticosteroids

We have found that early corticosteroid therapy was effective for reducing morbidity during five Korea-wide epidemics. We evaluated the clinical and laboratory parameters of 56 children who received early corticosteroid treatment for pneumonia that was caused by macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae) or macrolide-sensitive M. pneumoniae between July 2019 and February 2020. All subjects had dual positive results from a PCR assay and serological test, and received corticosteroids within 24–36 h after admission. Point mutation of residues 2063, 2064, and 2067 was identified in domain V of 23S rRNA. The mean age was 6.8 years and the male:female ratio was 1.2:1 (31:25 patients). Most of the subjects had macrolide-resistant M. pneumoniae (73%), and all mutated strains had the A2063G transition. No significant differences in clinical and laboratory parameters were observed between macrolide-resistant and macrolide-sensitive M. pneumoniae groups that were treated with early dose-adjusted corticosteroids. Higher-dose steroid treatment may be needed for patients who have fever that persists for >48 h or increased biomarkers such as lactate dehydrogenase concentration at follow-up despite a usual dose of steroid therapy.

Mortality and morbidity in children with asthma: A nationwide study in Korea

OBJECTIVE

Childhood mortality due to asthma remains problematic; however, asthma-related mortality in Korean children has not been previously described. This study aimed to estimate asthma mortality and morbidity and determine to what extent asthma contributes to childhood mortality in Korea.

METHODS

Data from 9 to 12 million children (aged < 18 years) per year recorded for each year between 2002 and 2015 were retrieved from the Korea National Health Insurance claims database. Patients with asthma during the year preceding death were investigated. Causes of death were analysed using data obtained from the Korean Statistical Information Service database. Cause-specific mortality was examined, and the mortality rate of children with asthma was compared to that of the general paediatric population with respect to the cause of death and age. Hospital use by patients with asthma, including intensive care unit admission and hospitalisation, was analysed.

RESULTS

Asthma mortality decreased from 0.09 per 100,000 children in 2003 to 0.02 per 100,000 children in 2014, with an average mortality of 0.06 per 100,000 children. Mortality due to respiratory diseases was four times more common in patients with asthma than in the general population of children aged >5 years, despite decreases in asthma-related mortality. Asthma-related hospitalisations and intensive care interventions tended to decrease throughout the study period.

CONCLUSIONS

Asthma mortality declined in children between 2003 and 2015 in Korea. Children with asthma are at a higher risk of death from respiratory diseases than the general population.

First report of macrolide-resistant and -susceptible Mycoplasma pneumoniae clinical strains isolated from a single case

OBJECTIVES

The aim of this study was to investigate the biological characteristics and effect of antibiotic treatment for different Mycoplasma pneumoniae isolates co-infecting the same patient.

METHODS

Two throat swab specimens from a single patient, on the day of admission (Sp01) and discharge (Sp13), were liquid cultured and subcultured on agar medium to obtain M. pneumoniae monoclones. The 23S rRNA gene of 50 monoclones from specimens Sp01 and Sp13 were analysed. Real-time PCR assay was used for detection of mutations and genotyping. Two typical monoclones were isolated for antimicrobial susceptibility testing.

RESULTS

Genotype 1 monoclones accounted for 70.8% (34/48) in Sp01 and 95.7% (44/46) in Sp13. All genotype 1 monoclones were of the 4-5-7-2 multilocus variable-number tandem-repeat analysis (MLVA) type, while all genotype 2 monoclones were 3-5-6-2 MLVA type. The genotype 1 monoclone, which harboured the A2063G mutation in 23S rRNA gene, was resistant to erythromycin and azithromycin in vitro, whilst genotype 2, which did not carry the mutation, was susceptible to macrolides. The proportion of macrolide-resistant M. pneumoniae monoclones in the specimen cultures collected rose from 70.8% to 95.7% at the time of discharge.

CONCLUSION

This is the first report on the isolation of macrolide-resistant and -susceptible strains of M. pneumoniae from the same patient. After treatment, the proportion of macrolide-resistant M. pneumoniae increased, but the patient still carried viable macrolide-susceptible strains, meaning that the macrolide-susceptible strains did not disappear completely.

Mycoplasma pneumoniae: Atypical Pathogen in Community Acquired Pneumonia

Mycoplasma pneumoniae is a one of most common reasons of respiratory tract infections in both adolescents and children with severity ranged from moderate to high. Many facts in the previous years regarding infections were induced via this organism having extra pathogenic mechanisms. Clinically, resistance to macrolide has produced internationally and represents a treatment trouble. Antimicrobial sensitivity checking out techniques have been applied, and novel antibiotics which are effective towards M. pneumoniae are present processing development. That evaluate concentrates on the several trends occurring in the previous quite a few years which beautify the grasp of that microorganism, which is one of the smallest pathogenic bacteria; however, is of extreme medical significance.

Recent acute reduction in macrolide-resistant Mycoplasma pneumoniae infections among Japanese children

INTRODUCTION

Mycoplasma pneumoniae contributes to numerous pneumonia cases among children and young adults. Therefore, this study aimed to investigate the prevalence of M. pneumoniae infections among Japanese children, occurring since 2008.

METHODS

Nasopharyngeal swab specimens were obtained from all cases, following which real-time PCR was performed to identify M. pneumoniae. Further, the p1 genotypes of isolates were determined using the PCR restriction fragment length polymorphism typing method.

RESULTS

The annual rate of macrolide-resistant M. pneumoniae (MRMP) infections peaked at 81.8% in 2012 and decreased annually until 2015. Although the infection rate increased to 65.3% in 2016, it decreased again to 14.3% in 2018. Although >90% of isolates harbored the type 1 genotype until 2012, this rate decreased, and approximately 80% harbored p1 genotypes other than type 1 in 2018. Furthermore, the occurrence rate of MRMP among the type 1 isolates was very high (82.4%), whereas that among p1 genotypes other than type 1 was very low (6.5%).

CONCLUSIONS

MRMP occurrence potentially decreased owing to changes in not only antibiotic usage but also in the distribution of p1 genotype among isolates.

Comparison of Nucleic Acid Amplification and IgM Tests for the Diagnosis of Mycoplasma pneumoniae Infection in Children During a Recent Korean Outbreak

OBJECTIVE

In the absence of standardized methods for Mycoplasma pneumoniae detection, we evaluated the diagnostic value of polymerase chain reaction (PCR) and IgM assays for detecting M. pneumoniae infection in children during a recent Korean outbreak.

METHODS

The diagnostic performances of PCR and IgM assays for M. pneumoniae in 1,109 clinical specimens were evaluated by the Japanese Respiratory Society (JRS) scoring system as an interim reference standard.

RESULTS

The level of agreement between both tests was fair. As analyzed by the JRS scoring system, the sensitivity of PCR was 45.2% in the group aged <5 years, 86.8% in the group aged 5 years to 10 years group, and 72.2% in the group aged 10 years to 18 years; the sensitivity of the IgM assay was 66.8%, 71.4%, and 55.6% in each group, respectively.

CONCLUSION

The sensitivity of PCR is relatively low but is superior to that of IgM assays such that diagnostic performance can be improved by both test methods in patients aged <5 years.

Immunochromatography for the diagnosis of Mycoplasma pneumoniae infection: A systematic review and meta-analysis

The aim of this study was to evaluate the diagnostic performance of immunochromatographic tests (ICTs) for the detection of Mycoplasma pneumoniae. Medline/Pubmed, Embase, the Cochrane Library, and ISI Web of Science were searched through June 12, 2019 for relevant studies that used ICTs for the detection of M. pneumoniae infection with polymerase chain reaction (PCR) or microbial culturing as reference standards. Pooled diagnostic accuracy with 95% confidence interval (CI) was calculated using a bivariate random effects model. We also constructed summary receiver operating characteristic curves and calculated the area under the curve (AUC). Statistical heterogeneity was evaluated by χ² test or Cochrane’s Q test. Thirteen studies including 2,235 samples were included in the meta-analysis. The pooled sensitivity and specificity for diagnosing M. pneumoniae infection were 0.70 (95% CI: 0.59–0.79) and 0.92 (95% CI: 0.87–0.95), respectively. The positive likelihood ratio (LR) was 8.94 (95% CI: 4.90–14.80), negative LR 0.33 (95% CI: 0.22–0.46), diagnostic odds ratio 29.20 (95% CI: 10.70–64.20), and AUC 0.904. In subgroup analysis, ICTs demonstrated similar pooled sensitivities and specificities in populations of children only and mixed populations (children + adults). Specimens obtained from oropharyngeal swabs exhibited a higher sensitivity and specificity than those of nasopharyngeal swab. Moreover, pooled estimates of sensitivity and accuracy for studies using PCR as a reference standard were higher than those using culture. The pooled sensitivity and specificity of Ribotest Mycoplasma^®, the commercial kit most commonly used in the included studies, were 0.66 and 0.89, respectively. Overall, ICT is a rapid user-friendly method for diagnosing M. pneumoniae infection with moderate sensitivity, high specificity, and high accuracy. This suggests that ICT may be useful in the diagnostic workup of M. pneumoniae infection; however, additional studies are needed for evaluating the potential impact of ICT in clinical practice.

Comparative efficacy of Chinese herbal injections combined with azithromycin for mycoplasma pneumonia in children: A Bayesian network meta-analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

An increasing macrolide resistance leads to complex clinical treatment schemes in mycoplasma pneumonia in children. Chinese herbal injection (CHI) is widely used to treat it and may provide a new treatment regimen. This study was conducted to systematically evaluate the efficacy of CHIs combined with azithromycin for treating mycoplasma pneumonia in children by Bayesian network meta-analysis.

METHODS

Randomized controlled trials (RCTs) of CHIs combined with azithromycin for mycoplasma pneumonia in children were searched in electronic databases and related references from initiation to 30 October 2018. Two researchers conducted data extraction and risk of bias assessment. WinBUGS software and STATA software were adopted to analyse the data.

RESULTS

A total of 167 RCTs were included with 5 CHIs involving 16 144 patients. All CHIs combined with azithromycin had superior effects than azithromycin only among overall outcomes. Yanhuning injection combined with azithromycin ranked highest in four different outcomes and second in two based on surface under the cumulative ranking probabilities (SUCRA). Meanwhile, the results of MD and 95% CIs of concerned outcomes indicated that only Yanhuning injection combined with azithromycin had better response than other CHIs combined with azithromycin. Moreover, cluster analysis results revealed Reduning injection combined with azithromycin was associated with a positive effect on the three group outcomes. Similarly, it was found to be the top three ranking in all outcomes based on SUCRA.

WHAT IS NEW AND CONCLUSION

Yanhuning injection combined with azithromycin and Reduning injection combined with azithromycin were found to be preferable treatments based on the data of this study.

Benefits and risks of therapeutic alternatives for macrolide resistant Mycoplasma pneumoniae pneumonia in children

Although Mycoplasma pneumoniae pneumonia (MPP) has been generally susceptible to macrolides, the emergence of macrolide-resistant MPP (MRMP) has made its treatment challenging. MRMP rapidly spread after the 2000s, especially in East Asia. MRMP is more common in children and adolescents than in adults, which is likely related to the frequent use of macrolides for treating M. pneumoniae infections in children. MRMP is unlikely to be related to clinical, laboratory, or radiological severity, although it likely prolongs the persistence of symptoms and the length of hospital stay. Thereby, it causes an increased burden of the disease and poor quality of life for the patient as well as a societal socioeconomic burden. To date, the only alternative treatments for MRMP are secondary antimicrobials such as tetracyclines (TCs) or fluoroquinolones (FQs) or systemic corticosteroids; however, the former are contraindicated in children because of concerns about potential adverse events (i.e., tooth discoloration or tendinopathy). A few guidelines recommended TCs or FQs as the second-line drug of choice for treating MRMP. However, there have been no evidence-based guidelines. Furthermore, safety issues have not yet been resolved. Therefore, this article aimed to review the benefits and risks of therapeutic alternatives for treating MRMP in children and review the recommendations of international or regional guidelines and specific considerations for their practical application.

Early Corticosteroid Therapy for Mycoplasma pneumoniae Pneumonia Irrespective of Used Antibiotics in Children

Antibiotics’ effect on Mycoplasma pneumoniae (MP) infection still remains controversial. A prospective study of 257 children with MP pneumonia during a recent epidemic (2015–2016) was conducted. All MP pneumonia patients were treated with corticosteroids within 24–36 h after admission. Initially, oral prednisolone (1 mg/kg) or intravenous methylprednisolone (IVMP; 1–2 mg/kg) was administered for mild pneumonia patients, and IVMP (5–10 mg/kg/day) for severe pneumonia patients. If patients showed a persistent fever for 36–48 h or disease progression, additive IVMP (5 mg/kg or 10 mg/kg) was given. Thirty-three percent of patients received only a broad-spectrum antibiotic without a macrolide. The mean age and the male-to-female ratio was 5.6 ± 3.1 years and 1:1, respectively. Seventy-four percent of patients showed immediate defervescence within 24 h, and 96% of patients showed defervescence within 72 h with improvements in clinical symptoms. Three percent of patients (8/257) who received additive IVMP also showed clinical improvement within 48 h without adverse reactions. There were no clinical or laboratory differences between patients treated with a macrolide (n = 172) and without (n = 85). Early corticosteroid therapy might reduce disease morbidity and prevent disease progression in MP pneumonia patients without side effects, and antibiotics may have limited effects on MP infection.

Clonal Expansion of Macrolide-Resistant Sequence Type 3 Mycoplasma pneumoniae, South Korea

To investigate the genetic background for the emergence of macrolide resistance, we characterized the genetic features of Mycoplasma pneumoniae using multilocus sequence typing. Of the 146 M. pneumoniae strains collected during the 5 consecutive outbreaks of M. pneumoniae pneumonia during 2000–2016 in South Korea, macrolide resistance increased from 0% in the first outbreak to 84.4% in the fifth. Among the 8 sequence types (STs) identified, ST3 (74.7%) was the most prevalent, followed by ST14 (15.1%). Macrolide-susceptible strains comprised 8 different STs, and all macrolide-resistant strains were ST3 (98.3%) except 1 with ST14. The proportion of macrolide-resistant strains in ST3 remained 2.2% (1/46) until the 2006–2007 outbreak and then markedly increased to 82.6% (19/23) during the 2010–2012 outbreak and 95.0% (38/40) during the 2014–2016 outbreak. The findings demonstrated that clonal expansion of ST3 M. pneumoniae was associated with the increase in macrolide resistance in South Korea.

Recommendations and guidelines for the treatment of pneumonia in Taiwan

Pneumonia is a leading cause of death worldwide, ranking third both globally and in Taiwan. This guideline was prepared by the 2017 Guidelines Recommendations for Evidence-based Antimicrobial agents use in Taiwan (GREAT) working group, formed under the auspices of the Infectious Diseases Society of Taiwan (IDST). A consensus meeting was held jointly by the IDST, Taiwan Society of Pulmonary and Critical Care Medicine (TSPCCM), the Medical Foundation in Memory of Dr. Deh-Lin Cheng, the Foundation of Professor Wei-Chuan Hsieh for Infectious Diseases Research and Education and CY Lee's Research Foundation for Pediatric Infectious Diseases and Vaccines. The final guideline was endorsed by the IDST and TSPCCM. The major differences between this guideline and the 2007 version include the following: the use of GRADE methodology for the evaluation of available evidence whenever applicable, the specific inclusion of healthcare-associated pneumonia as a category due to the unique medical system in Taiwan and inclusion of recommendations for treatment of pediatric pneumonia. This guideline includes the epidemiology and recommendations of antimicrobial treatment of community-acquired pneumonia, hospital-acquired pneumonia, ventilator-associated pneumonia, healthcare-associated pneumonia in adults and pediatric pneumonia.

Antimicrobial susceptibility and genotyping of Mycoplasma pneumoniae isolates in Beijing, China, from 2014 to 2016

Background

The presence of macrolide-resistant Myocplasma pneumoniae has been frequently reported in recent years, especially in China. In this study, we investigated the antimicrobial susceptibility and genotype against M. pneumoniae isolates from 2014 to 2016, Beijing.

Methods

We investigated the activities of four antibiotics against 81 M. pneumoniae isolates in vitro. All isolates were amplification of domains II and V of the 23S rRNA gene and the L4 and L22 ribosomal protein fragments. All isolates were genotyped with duplex real-time PCR, MLVA and VNTR detection in p1 gene.

Results

The macrolide resistance rate was 65.4% (53/81). Each of the macrolide-resistant M. pneumoniae isolates was resistant to erythromycin (Minimum Inhibitory Concentration, MIC, ≥256 μg/ml) and azithromycin (MIC, 2-64 μg/ml), but susceptible to tetracycline and levofloxacin in vitro. Fifty two macrolide-resistant isolates harbored the A2063G mutation, and only 1 macrolide-resistant isolates harbored the A2064G mutation in domain V of the 23S ribosomal RNA gene. The C162A, A430G, and T279C mutations in the L4 and L22 ribosomal protein genes were not responsible for macrolide resistance, but they were related to the particular genotype of M. pneumoniae. 95.7% of type 1 isolates (45/47) were macrolide-resistance, and 23.5% of the type 2 isolates (8/34) were macrolide-resistance. Type 2 M. pneumoniae macrolide-resistance rate was 50.6% higher than that of the previous reports in China. The eight macrolide-resistant type 2 M. pneumoniae isolates were belong to 3/5/6/2 and 3/5/7/2 MLVA genotypes.

Conclusion

To our knowledge, this phenomenon likely resulted from a combination of genotype shifting from type1 to type 2 and antibiotic selection pressure in M. pneumoniae in China in recent years. The increase of resistance in type 2 is not due to the spread of same clone. However, the relationship between genotype shifts and macrolide resistance in M. pneumoniae needs to be further verified with more extensive surveillance data.

Implementation of Point-of-Care Molecular Diagnostics for Mycoplasma pneumoniae Ensures the Correct Antimicrobial Prescription for Pediatric Pneumonia Patients

Mycoplasma pneumoniae is a leading causative pathogen of pneumonia among pediatric patients, and its accurate diagnosis may aid in the selection of appropriate antimicrobial agents. We established a rapid reporting system of a polymerase chain reaction (PCR) examination for M. pneumoniae that enables physicians to obtain test results approximately 90 minutes after ordering the test. In this study, we evaluated the impact of this system on antimicrobial prescriptions for pediatric pneumonia patients after its implementation from May 2016 to April 2017. In total, we identified 375 pediatric pneumonia patients, and the results of the rapid PCR examinations for Mycoplasma pneumoniae were reported immediately in 90.7% of patients (340/375), with physicians able to use these results to decide on patients' management before the prescription of antimicrobial agents. Of the 375 pediatric pneumoniae patients, M. pneumoniae was detected in 223 (59.5%). Among the 223 M. pneumoniae-positive pneumonia cases, antimicrobial agents for atypical pathogens (macrolides, tetracyclines or quinolones) were prescribed in 97.3% (217/223) at the initial evaluation, and their prescription rates increased to 99.1% (221/223) during management. In contrast, antimicrobial agents for atypical pathogens were prescribed only in 10.5% of 152 M. pneumoniae-negative pneumonia cases at the initial evaluations, and only 1 additional case was prescribed clarithromycin for persistent symptoms during management. In conclusion, we show that molecular technology could be applicable in the field of point-of-care testing in infectious disease, and its implementation will ensure the correct antimicrobial prescription for pediatric pneumonia patients.

Macrolide-resistant Mycoplasma pneumoniae in South Korea: a strong association with M. pneumoniae type 1

Mycoplasma pneumoniae is a main pathogen causing community-acquired pneumonia in children and young adults. Since the emergence of macrolide-resistant M. pneumoniae in the early 2000s in Japan, it has been increasingly reported worldwide as a growing problem in treatment for children. With increasing macrolide-resistant M. pneumoniae and limited data regarding its characterization and molecular analysis, we investigated the dominant M. pneumoniae strains during the recent outbreak in South Korea, and evaluated if there was an association between a specific type and macrolide resistance. Between October 2014 and December 2016 in South Korea, 249 respiratory specimens obtained from patients with confirmed M. pneumoniae pneumonia were genotyped the P1 adhesin gene, and the mutations associated with resistance (A2063G and A2064G) were tested by sequencing the targeted domain V regions of the 23S ribosomal RNA gene. Results revealed that M. pneumoniae type 1 were predominant, which was strongly associated with macrolide-resistance during the whole study period. This is the first study assessing whether M. pneumoniae subtype is related to macrolide resistance during the outbreak of M. pneumoniae.

Therapeutic Efficacy and Safety of Prolonged Macrolide, Corticosteroid, Doxycycline, and Levofloxacin against Macrolide-Unresponsive Mycoplasma pneumoniae Pneumonia in Children

BACKGROUND

We aimed to compare the therapeutic efficacy of prolonged macrolide (PMC), corticosteroids (CST), doxycycline (DXC), and levofloxacin (LFX) against macrolide-unresponsive Mycoplasma pneumoniae (MP) pneumonia in children and to evaluate the safety of the secondary treatment agents.

METHODS

We retrospectively analyzed the data of patients with MP pneumonia hospitalized between January 2015 and April 2017. Macrolide-unresponsiveness was clinically defined with a persistent fever of ≥ 38.0°C at ≥ 72 hours after macrolide treatment. The cases were divided into four groups: PMC, CST, DXC, and LFX. We compared the time to defervescence (TTD) after secondary treatment and the TTD after initial macrolide treatment in each group with adjustment using propensity score-matching analysis.

RESULTS

Among 1,165 cases of MP pneumonia, 190 (16.3%) were unresponsive to macrolides. The proportion of patients who achieved defervescence within 48 hours in CST, DXC, and LFX groups were 96.9% (31/33), 85.7% (12/14), and 83.3% (5/6), respectively. The TTD after initial macrolide treatment did not differ between PMC and CST groups (5.1 vs. 4.2 days, P = 0.085), PMC and DXC groups (4.9 vs. 5.7 days, P = 0.453), and PMC and LFX groups (4.4 vs. 5.0 days, P = 0.283). No side effects were observed in the CST, DXC, and LFX groups.

CONCLUSION

The change to secondary treatment did not show better efficacy compared to PMC in children with macrolide-unresponsive MP pneumonia. Further studies are needed to guide appropriate treatment in children with MP pneumonia.

Increased procalcitonin level is a risk factor for prolonged fever in children with Mycoplasma pneumonia

PURPOSE

Macrolide-resistant Mycoplasma pneumoniae pneumonia (MPP) is characterized by prolonged fever and radiological progression despite macrolide treatment. Few studies have examined serum procalcitonin (PCT) level in children with MPP. We aimed to investigate the association of acute inflammation markers including PCT with clinical parameters in children with MPP.

METHODS

A total of 147 children were recruited. The diagnosis of MPP relied on serial measurement of IgM antibody against mycoplasma and/or polymerase chain reaction. We evaluated the relationships between C-reactive protein (CRP), PCT, and lactate dehydrogenase (LDH) levels and white blood cell (WBC) counts, and clinical severity of the disease. We used multivariate logistic regression analysis to estimate the odds ratio for prolonged fever (>3 days after admission) and hospital stay (> 6 days), comparing quintiles 2-5 of the PCT levels with the lowest quintile.

RESULTS

The serum PCT and CRP levels were higher in children with fever and hospital stay than in those with fever lasting ≤ 3 days after admission and hospital stay ≤ 6 days. CRP level was higher in segmental/lobar pneumonia than in bronchopneumonia. The LDH level and WBC counts were higher in children with fever lasting for >3 days before compared to those with fever lasting for ≤ 3 days. The highest quintile of PCT levels was associated with a significantly higher risk of prolonged fever and/or hospital stay than the lowest quintile.

CONCLUSION

Serum PCT and CRP levels on admission day were associated with persistent fever and longer hospitalization in children with MPP.

Guideline for Antibiotic Use in Adults with Community-acquired Pneumonia

Community-acquired pneumonia is common and important infectious disease in adults. This work represents an update to 2009 treatment guideline for community-acquired pneumonia in Korea. The present clinical practice guideline provides revised recommendations on the appropriate diagnosis, treatment, and prevention of community-acquired pneumonia in adults aged 19 years or older, taking into account the current situation regarding community-acquired pneumonia in Korea. This guideline may help reduce the difference in the level of treatment between medical institutions and medical staff, and enable efficient treatment. It may also reduce antibiotic resistance by preventing antibiotic misuse against acute lower respiratory tract infection in Korea.

Contribution of Co-detected Respiratory Viruses and Patient Age to the Clinical Manifestations of Mycoplasma Pneumoniae Pneumonia in Children

BACKGROUND

The clinical spectrum of Mycoplasma pneumoniae pneumonia is widely variable. This study evaluated the clinical manifestations of M. pneumoniae pneumonia in children of different age groups and by the presence of co-detected respiratory virus.

METHODS

This study included children hospitalized with M. pneumoniae pneumonia between 2010 and 2015. At the time of pneumonia diagnosis, a nasopharyngeal aspirate was analyzed for respiratory viruses by reverse transcription-polymerase chain reaction (RT-PCR). The clinical manifestations and laboratory findings were reviewed from medical records.

RESULTS

Of the 286 children with M. pneumoniae pneumonia, 84 (29.4%) had a co-detected respiratory virus, with the highest co-detection rate in young children (51.9% of children <2 years; P = 0.002). In children <2 years, with and without co-detected virus, wheezing occurred in 35.7% and 15.4%, respectively. Among the 202 children without any virus detected, only 6.4% were <2 years. These young children showed fewer median days of fever than the children ≥2 years (8 vs. 11 days; P = 0.022). Children ≥2 years tended to have accompanying skin rashes (21.7% vs.7.7%; P = 0.310) and elevated liver enzymes (21.7% vs. 0%; P = 0.075) more frequently than children <2 years. Only 53.8% of the patients <2 years were treated with macrolide compared with 94.1% of the patients ≥2 years (P < 0.001).

CONCLUSIONS

The clinical manifestations of M. pneumoniae pneumonia in young children are milder than those in older children. A high prevalence of co-detected respiratory virus in young children suggests that virus might play a role in making pneumonia clinically apparent in this age group.

Recent trends in practice patterns and impact of corticosteroid use on pediatric Mycoplasma pneumoniae-related respiratory infections

BACKGROUND

Mycoplasma pneumoniae is a major pathogen causing community-acquired pneumonia/bronchitis in children, and macrolide-resistant strains are increasing in East Asian countries. Recent practice patterns, especially for antibiotic selection, and benefits of corticosteroid treatment in pediatric Mycoplasma pneumoniae infections remain unclear.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database, we analyzed recent trends in antibiotic selection and corticosteroid use for pediatric Mycoplasma pneumoniae-related respiratory infections, using multivariable mixed effects logistic regressions. In addition, we compared hospital utilization and readmission between children who received corticosteroids and those who did not, using propensity-score matching and instrumental variable analyses.

RESULTS

Overall, 51,633 inpatients were identified. From 2010 to 2014, the use of macrolides and lincosamides decreased from 62.8% to 50.6% and from 25.6% to 13.7% respectively (P_trend < 0.001), whereas fluoroquinolone use increased from 4.6% to 22.6% (P_trend < 0.001). Tetracycline use did not demonstrate a significant change in trend. Propensity score matching analysis showed that hospital stay in the steroid group was 0.90 days longer than in the non-steroid group (95% confidence interval, 0.84-0.96). Total hospitalization cost was higher in the steroid compared to the non-steroid group (57.6 US dollars; 95% CI, 48.8-66.8). A significant difference in 30-day readmission risk was observed between the steroid (1.6%) and non-steroid (1.2%) groups (risk difference 0.4%; 95% CI, 0.1-0.7%). Similar results were observed on instrumental variable analyses.

CONCLUSIONS

Increasing trends in fluoroquinolone use and decreasing trends in macrolide use were observed. Our study did not prove the benefits of corticosteroid use. Further studies are required to confirm the clinical benefits of corticosteroid treatment.