Macrolide-resistant Mycoplasma pneumoniae: characteristics of isolates and clinical aspects of community-acquired pneumonia. J Infect Chemother. 2010;16:78-86. [PMID: 20094751 DOI: 10.1007/s10156-009-0021-4]

Understanding serum inflammatory markers in pediatric Mycoplasma pneumoniae pneumonia

This editorial reflects on the research, which investigates the potential of serum markers to predict the severity of Mycoplasma pneumoniae infections. Mycoplasma pneumoniae pneumonia (MPP) is a prevalent cause of respiratory infections in children, often leading to significant morbidity. Predicting the severity of MPP can significantly enhance patient management and outcomes. This editorial reviews the role of specific laboratory markers: (1) Lactate dehydrogenase; (2) Interleukin (IL)-6; (3) IL-10; (4) Tumor necrosis factor-α; and (5) D-dimer in predicting the severity of MPP in pediatric patients. Elevated levels of these markers are strongly associated with severe cases of MPP, providing clinicians with valuable tools for early diagnosis and targeted intervention.

Laboratory diagnosis and treatment of Mycoplasma pneumoniae infection in children: a review

Mycoplasma pneumoniae (MP) is the cause of Mycoplasma pneumoniae pneumonia (MPP) in children and adolescents, with the clinical manifestations highlighted by intermittent irritating cough, accompanied by headache, fever and muscle pain. This paper aimed to study the research status and focal points in MP infection, especially the common laboratory diagnostic methods and clinical treatment of Mycoplasma pneumoniae. Laboratory diagnostic methods include molecular assay, serological antibody detection, rapid antigen detection and isolation and culture. Polymerase chain reaction (PCR) is the gold standard with high sensitivity and specificity. The serological antibody can detect various immune antibodies qualitatively or quantitatively in serum. Rapid antigen can be detected faster, with no equipment environment requirements, which can be used for the early diagnosis of MP infection. While the culture growth cycle is long and insensitive, not recommended for routine diagnosis. Macrolides were the preferred drug for children with MPP, while the drug resistance rate was rising in China. Tetracycline can be substituted but was not recommended for children under 8 years of age, quinolone drugs are not necessary, severe MPP can be combined with glucocorticoids, involving the nervous or immune system can choose gamma globulin. Other treatments for MPP including symptomatic treatment which can alleviate symptoms, improve lung function and improve prognosis. A safe and effective vaccine needed to be developed which can provide protective immunity to children and will reduce the incidence of MPP.

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.

New Insights into the Epidemiological Characteristics of Mycoplasma pneumoniae Infection before and after the COVID-19 Pandemic

Mycoplasma pneumoniae (M. pneumoniae), a prevalent respiratory pathogen affecting children and adolescents, is known to trigger periodic global epidemics. The most recent significant outbreak commenced in the first half of 2023 and reached its peak globally during the autumn and winter months. Considering the worldwide repercussions of the COVID-19 pandemic, it has become increasingly essential to delve into the epidemiological characteristics of M. pneumoniae both before and after the pandemic. This review aims to provide a comprehensive analysis of the key features of M. pneumoniae epidemics in the pre-and post-COVID-19 contexts, including but not limited to shifts in the susceptible population, the molecular genotypes of the pathogen, the clinical manifestations, and potential new trends in drug resistance. Additionally, we will introduce the latest advancements in the diagnosis of M. pneumoniae.

Expert consensus on the diagnosis and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is a significant contributor to community-acquired pneumonia among children. Since 1968, when a strain of M. pneumoniae resistant to macrolide antibiotics was initially reported in Japan, macrolide-resistant M. pneumoniae (MRMP) has been documented in many countries worldwide, with varying incidence rates. MRMP infections lead to a poor response to macrolide antibiotics, frequently resulting in prolonged fever, extended antibiotic treatment, increased hospitalization, intensive care unit admissions, and a significantly higher proportion of patients receiving glucocorticoids or second-line antibiotics. Since 2000, the global incidence of MRMP has gradually increased, especially in East Asia, which has posed a serious challenge to the treatment of M. pneumoniae infections in children and attracted widespread attention from pediatricians. However, there is still no global consensus on the diagnosis and treatment of MRMP in children.

METHODS

We organized 29 Chinese experts majoring in pediatric pulmonology and epidemiology to write the world's first consensus on the diagnosis and treatment of pediatric MRMP pneumonia, based on evidence collection. The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, CNKI, Medline, and the Cochrane Library. We used variations in terms for "macrolide-resistant", "Mycoplasma pneumoniae", "MP", "M. pneumoniae", "pneumonia", "MRMP", "lower respiratory tract infection", "Mycoplasma pneumoniae infection", "children", and "pediatric".

RESULTS

Epidemiology, pathogenesis, clinical manifestations, early identification, laboratory examination, principles of antibiotic use, application of glucocorticoids and intravenous immunoglobulin, and precautions for bronchoscopy are highlighted. Early and rapid identification of gene mutations associated with MRMP is now available by polymerase chain reaction and fluorescent probe techniques in respiratory specimens. Although the resistance rate to macrolide remains high, it is fortunate that M. pneumoniae still maintains good in vitro sensitivity to second-line antibiotics such as tetracyclines and quinolones, making them an effective treatment option for patients with initial treatment failure caused by macrolide antibiotics.

CONCLUSIONS

This consensus, based on international and national scientific evidence, provides scientific guidance for the diagnosis and treatment of MRMP in children. Further studies on tetracycline and quinolone drugs in children are urgently needed to evaluate their effects on the growth and development. Additionally, developing an antibiotic rotation treatment strategy is necessary to reduce the prevalence of MRMP strains.

Disease burden and macrolide resistance of Mycoplasma pneumoniae infection in adults in the Asia-Pacific region

OBJECTIVES

In the Asia-Pacific region, Mycoplasma pneumoniae (MP) could be a notable pathogen responsible for adult community-acquired pneumonia (CAP), with varying prevalence rates. This comprehensive review aimed to explore the epidemiology, clinical manifestations, macrolide resistance, and molecular characteristics of MP in adults across several countries in Asia.

METHODS

PubMed, Embase, and Google Scholar were searched for relevant articles from 2010-2023 based on the following keywords: adult and Mycoplasma pneumoniae.

RESULTS

The prevalence of MP in CAP patients in these countries ranged from 2.1% in Korea to 25.5% in Japan. Macrolide resistance was prominent, particularly in China, with rates ranging 26.9-100%. Clinical manifestations of MP infection included protean extrapulmonary manifestations, and complications such as rhabdomyolysis and thrombocytopenia. Molecular characteristics, especially the multiple locus variable-number tandem-repeat analysis type 4/5/7/2, remained predominant across various countries, emphasising the importance of ongoing surveillance.

CONCLUSIONS

This review highlights the urgent need for continued monitoring of MP infections, macrolide resistance, and molecular characteristics to inform effective prevention and treatment strategies in the Asia-Pacific region.

Macrolide-Resistant Mycoplasma pneumoniae Infections among Children before and during COVID-19 Pandemic, Taiwan, 2017-2023

Before the COVID-19 pandemic, Mycoplasma pneumoniae infections emerged during spring to summer yearly in Taiwan, but infections were few during the pandemic. M. pneumoniae macrolide resistance soared to 85.7% in 2020 but declined to 0% during 2022-2023. Continued molecular surveillance is necessary to monitor trends in macrolide-resistant M. pneumoniae.

Influence of non-pharmaceutical interventions on epidemiological characteristics of Mycoplasma pneumoniae infection in children during and after the COVID-19 epidemic in Ningbo, China

Background

Since the outbreak of COVID-19, China has implemented a series of non-pharmaceutical interventions (NPIs), effectively containing the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as various respiratory pathogens. With the continuous relaxation of restrictions, China has entered a new phase of the post-pandemic era. However, the epidemiological differences of Mycoplasma pneumoniae (MP) between the two phases in Ningbo and even in China remain unclear.

Methods

Data of children aged 0-14 years who visited the Ningbo Medical Center LiHuiLi Hospital due to acute respiratory tract infections from January 2020 to December 2023 were collected. PCR was used to detect 13 respiratory pathogens and the macrolide-resistance of Mycoplasma pneumoniae.

Results

Among 10,206 children, 2,360 were infected with MP (23.12%). Among the total, the MP positive rate during the NPI phase (6.35%) was significantly lower than that during the non-NPI phase (34.28%), while the macrolide resistance rate increased from 62.5% (NPI phase) to 81.1% (non-NPI phase). The rate of MP co-infection increased from 11.2% (NPI phase) to 30.3% (non-NPI phase). MP infection exhibited obvious seasonality, with the highest prevalence in autumn (30.0%) followed by summer (23.6%). There were differences in MP positivity rates among different age groups, with the highest among school-age children at 39.5%. During the NPI phase, all age groups were less susceptible to MP, while during the non-NPI phase, the susceptible age for MP was 4-12 years, with 8 years being the most susceptible. The susceptible age for MP co-infection was 0-6 years. MP exhibited antagonistic effects against numerous pathogens. Compared to MP single infection, the proportion of pneumonia was higher in MP co-infection cases.

Conclusion

The removal of NPIs significantly impacted the spread of MP, altering population characteristics including age, seasonality, macrolide resistance, and MP co-infection rates.

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.

Novel Knowledge of Macrolide Resistance in Mycoplasma pneumoniae by Azithromycin Exposure

The rise of macrolide-resistant Mycoplasma pneumoniae (MRMP), marked by point mutations in the 23S rRNA gene, poses a growing global concern since its initial detection in 2001. The prominence of the A2063G mutation during this emergence remains unexplained. This study aimed to clarify the possibility of detecting MRMP from recent clinical macrolide-susceptible M. pneumoniae through exposure to azithromycin (AZM), which has a long half-life and was launched immediately before the first MRMP detection. Six strains isolated from Japanese children in 2019 and reference strain (FH), all belonging to the recent dominant P1 genotype, two, or two subtype, were cultivated in a medium containing slightly higher concentrations than the originated minimum inhibitory concentration (MIC) of AZM and underwent sequencing if they grew. Four out of the seven strains grew after exposure to AZM, and C2617G and C2617A were detected, with no mutation in two strains. After another cultivation and sequencing, two of four strains grew, one was changed from C2617G to A2063G, and the other remained C2617A. The MIC of AZM in A2063G strains was 128 mg/mL; for C2617A, it was 0.0156 mg/mL. This is the first study to detect the strains with A2063G mutation from recent macrolide-susceptible M. pneumoniae using AZM exposure.

Characteristics of the Mycoplasma pneumoniae Epidemic from 2019 to 2020 in Korea: Macrolide Resistance and Co-Infection Trends

Mycoplasma pneumoniae, a major etiological agent of community-acquired pneumonia, exhibits distinct cyclic epidemic patterns recurring every three to five years. Several cases of co-infection with severe acute respiratory syndrome coronavirus 2 have been reported globally, resulting in unfavorable clinical manifestations. This study investigated the epidemiological features of the recent M. pneumoniae outbreak (May 2019-April 2020) using retrospective data from the last five years. Molecular test data for macrolide resistance and co-infection were obtained from the Seegene Medical Foundation. National medical expenditure and hospitalization rates were analyzed using data from The Health Insurance Review and Assessment Service of Korea. The macrolide resistance rate was 69.67%, peaking at 71.30% during the epidemic period, which was considerably higher than the 60.89% rate during non-epidemic periods. The co-infection rate with other respiratory pathogens was 88.49%; macrolide-resistant M. pneumoniae strains showed a 2.33% higher co-infection rate than the susceptible strains. The epidemic period had 15.43% higher hospitalization and 78.27% higher medical budget expenditure per patient than non-epidemic periods. The increased rates of macrolide resistance and co-infection observed in macrolide-resistant M. pneumoniae during the epidemic period highlight the importance of monitoring future outbreaks, especially considering macrolide resistance and the risk of co-infection with other pathogens.

Proteomic and Phenotypic Studies of Mycoplasma pneumoniae Revealed Macrolide-Resistant Mutation (A2063G) Associated Changes in Protein Composition and Pathogenicity of Type I Strains

Mycoplasma pneumoniae (MP) is an important respiratory pathogen, the prevalence of macrolide-resistant MP (mainly containing A2063G mutation in 23S rRNA) increased in recent years. Epidemiological studies suggest a higher prevalence of type I resistant (IR) strains than corresponding sensitive (IS/IIS) strains, but not type II resistant (IIR) strains. Here, we aimed to analyze the factors underlying the altered prevalence of IR strains. First, proteomic analyses exhibit the protein compositions were type specific, while more differential proteins were detected between IS and IR (227) than IIS and IIR strains (81). mRNA level detection suggested posttranscriptional regulation of these differential proteins. Differential protein-related phenotypic changes were also detected: (i) P1 abundance was different between genotypes (I < II, IR < IS), the adhesion of MPs showed accordance to P1 abundance within IS and IIS strains; (ii) type I, especially IR, strains had a higher proliferation rate, which is potentially associated with differential proteins participating in glycolysis and one carbon pool metabolisms; (iii) A549 cells infected with IR strains had lower activity of caspase-3 and higher levels IL-8, but the differences were not significant between groups (P > 0.05). Correlations of P1 abundance to caspase-3 activity and proliferation rate to the level of IL-8 were obtained. These results suggest changes in protein composition influenced the pathogenicity of MP, especially in IR strains, which may impact the prevalence of MP strains of different genotypes. IMPORTANCE The prevalence of macrolide-resistant MPs increased the difficulty in treatment of MP infections and posed potential threats to children's health. Epidemiological studies showed a high prevalence of IR-resistant strains (mainly A2063G in 23S rRNA) in these years. However, the trigger mechanisms for this phenomenon are not clear. In this paper, proteomic and phenotypic studies suggest that IR strains have reduced levels of multiple adhesion proteins and increased proliferation rate, which may lead to higher transmission rate of IR strains in the population. This suggests that we should pay attention to the prevalence of IR strains.

Galacto-Oligosaccharides as an Anti-Infective and Anti-Microbial Agent for Macrolide-Resistant and -Sensitive Mycoplasma pneumoniae

The worldwide increase in the incidence of antibiotic resistance of the atypical bacterium Mycoplasma pneumoniae (MP) challenges the treatment of MP infections, especially in children. Therefore, alternative strategies for the treatment of MP infections are warranted. Galacto- and fructo-oligosaccharides (GOS and FOS) are a specific group of complex carbohydrates that were recently shown to possess direct anti-pathogenic properties. In this study, we assessed whether GOS and FOS exert anti-microbial and anti-infective effects against MP and, especially, macrolide-resistant MP (MRMP) in vitro. The MIC values of GOS for MP and MRMP were 4%. In contrast, the MIC values of FOS for both MP and MRMP were 16%. A time-kill kinetic assay showed that FOS possess bacteriostatic properties, while for GOS, a bactericidal effect against MP and MRMP was observed after 24 h at a concentration of 4x MIC. In co-cultures with human alveolar A549 epithelial cells, GOS killed adherent MP and MRMP and also concentration-dependently inhibited their adherence to A549 cells. Further, GOS suppressed (MR)MP-induced IL-6 and IL-8 in A549 cells. None of the aforementioned parameters were affected when FOS were added to these co-cultures. In conclusion, the anti-infective and anti-microbial properties of GOS could provide an alternative treatment against MRMP and MP infections.

Vimentin Is an Attachment Receptor for Mycoplasma pneumoniae P1 Protein

Mycoplasma pneumoniae is the most common pathogen causing respiratory tract infection, and the P1 protein on its adhesion organelle plays a crucial role during the pathogenic process. Currently, there are many studies on P1 and receptors on host cells, but the adhesion mechanism of P1 protein is still unclear. In this study, a modified virus overlay protein binding assay (VOPBA) and liquid chromatography-mass spectrometry (LC-MS) were performed to screen for proteins that specifically bind to the region near the carboxyl terminus of the recombinant P1 protein (rP1-C). The interaction between rP1-C and vimentin or β-4-tubulin were confirmed by far-Western blotting and coimmunoprecipitation. Results verified that vimentin and β-4-tubulin were mainly distributed on the cell membrane and cytoplasm of human bronchial epithelial (BEAS-2B) cells, but only vimentin could interact with rP1-C. The results of the adhesion and adhesion inhibition assays indicated that the adhesion of M. pneumoniae and rP1-C to cells could be partly inhibited by vimentin and its antibody. When vimentin was downregulated with the corresponding small interfering RNA (siRNA) or overexpressed in BEAS-2B cells, the adhesion of M. pneumoniae and rP1-C to cells was decreased or increased, respectively, which indicated that vimentin was closely associated with the adhesion of M. pneumoniae and rP1-C to BEAS-2B cells. Our results demonstrate that vimentin could be a receptor on human bronchial epithelial cells for the P1 protein and plays an essential role in the adhesion of M. pneumoniae to cells, which may clarify the pathogenesis of M. pneumoniae. IMPORTANCE Mycoplasma pneumoniae is the most common pathogen causing respiratory tract infection, and the P1 protein on its adhesion organelle plays a crucial role during the pathogenic process. A variety of experiments, including enzyme-linked immunosorbent assay (ELISA), coimmunoprecipitation, adhesion, and adhesion inhibition assay, have demonstrated that the M. pneumoniae P1 protein can interact with vimentin, that the adhesion of M. pneumoniae and recombinant P1 protein to BEAS-2B cells was affected by the expression level of vimentin. This provides a new idea for the prevention and treatment of Mycoplasma pneumoniae infection.

Insight into potent TLR2 inhibitors for the treatment of disease caused by Mycoplasma pneumoniae based on machine learning approaches

Mycoplasma pneumoniae (MP) is one of the most common pathogens that causes acute respiratory tract infections. Children experiencing MP infection often suffer severe complications, lung injury, and even death. Previous studies have demonstrated that Toll-like receptor 2 (TLR2) is a potential therapeutic target for treating the MP-induced inflammatory response. However, the screening of natural compounds has received more attention for the treatment of bacterial infections to reduce the likelihood of bacterial resistance. Herein, we screened compounds by combining molecular docking and machine learning approaches to find potential lead compounds for treating MP infection. First, all compounds were docked with the TLR2 receptor protein to screen for potential candidates. To predict drug bioactivity, a machine learning model (random forest) was trained for TLR2 inhibitors to obtain the predictive model. The model achieved significant squared correlation coefficient (R²) values for the training set (0.85) and validation set (0.84) of compounds. The developed machine learning model was then used to predict the pIC50 values of the top 50 candidates from the Traditional Chinese compounds and Discovery Diversity sets of compounds. As a result, these compounds are capable of inhibiting the inflammatory response induced by MP. However, prior to bringing these compounds to market, it is necessary to verify these results with additional biological testing, including preclinical and clinical studies. Moreover, the present study provides a theoretical basis for the use of natural compounds as potential candidates to treat pneumonia caused by MP.

The clinical significance of and the factors associated with macrolide resistance and poor macrolide response in pediatric Mycoplasma pneumoniae infection: A retrospective study

BACKGROUND

Macrolide-resistant Mycoplasma pneumoniae (MRMP) infection is increasing worldwide. However, its clinical significance is still uncertain.

METHODS

The data of the Laboratory Medicine Department of Chang Gung Memorial Hospital in northern Taiwan was searched for children with molecular confirmed macrolide-susceptible Mycoplasma pneumoniae (MSMP) and MRMP infections between January 2011 and December 2018. The clinical features, laboratory data, and chest image presentations were compared between patients with MRMP and MSMP infections and between patients with good and poor macrolide response, respectively.

RESULTS

Records from 158 patients were recovered. Of the enrolled patients 34 (22%) suffered MRMP infection, 27 (17%) had pleural effusions, and 47 (32%) had poor macrolide response. The macrolide resistance rate was 12% in 2011, 20% between 2015 and 2016, and 50% between 2017 and 2018, respectively. Other than a poor macrolide response, the MRMP and MSMP infections are clinically indistinguishable. The presence of pleural effusion and MRMP infections were found to be independently associated with a poor macrolide response, with odds ratios (95% confidence interval) of 14.3 (4.9-42.0) and 14.6 (5.4-40), respectively. The macrolide resistance rate of the patients with a poor macrolide response was 49% and 18% among all the patients enrolled and the patients with a pleural effusion, respectively.

CONCLUSION

The macrolide resistance rate had possibly increased in recent years in Taiwan and should be continuously monitored. In addition, the macrolide response could be misleading in predicting a macrolide resistance especially for the patients with a pleural effusion.

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.

The role of flexible bronchoscopy in children with Mycoplasma pneumoniae pneumonia

PURPOSE

To explore the effectiveness of flexible bronchoscopy in pediatric Mycoplasma pneumoniae pneumonia (MPP).

METHODS

This retrospective cohort study included children with MPP admitted between 2016 and 2019 in Shanghai. Tracheobronchial manifestations, etiologic findings, therapeutic effect, and health-economic indicators were assessed in bronchoscopy (plus bronchoalveolar lavage (BAL)) and non-bronchoscopy group. We used propensity-score matching and multivariable logistic regression to investigate the effect of bronchoscopy and BAL on disease recovery.

RESULTS

In 900 children with MPP, 24/278 (8.6%) of those who underwent bronchoscopy had sputum plugs. Coinfection rate was four-fold enhanced by BAL (19.6% vs. 4.5%, p < 0.01) in patients with severe MPP (SMPP) and nearly doubled (10.8% vs. 5.9%, p = 0.03) in those without SMPP, compared with no BAL. Total of 224 (24.9%) patients had multilobar consolidation; after BAL, a significantly shorter lesion-resolution duration was observed on imaging (OR: 0.2, 95% CI: 0.0-0.7). However, longer fever duration (OR: 2.8, 95% CI: 1.7-4.8), hospital stay (OR: 3.1, 95% CI: 1.9-5.1), and higher costs were found in the bronchoscopy group than in the non-bronchoscopy group.

CONCLUSIONS

Through BAL, coinfection may explain one-fifth of causes for SMPP. Bronchoscopy with BAL may increase the detection rate of pathogen and resolve pulmonary lesions in patients with multilobar consolidation.

IMPACT

Flexible bronchoscopy with bronchoalveolar lavage is of great assistance in the timely detection of coinfection, sputum plug and inflammatory polyps in children with Mycoplasma pneumoniae pneumonia (MPP), and improves the recovery of lung damage in MPP patients with multilobar consolidation. This study provides new insights into the indications of flexible bronchoscopy for the diagnosis and treatment of pediatric patients with MPP.

Serum cytokine profiling reveals different immune response patterns during general and severe Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is an important human pathogen that mainly affects children causing general and severe Mycoplasma pneumoniae pneumonia (G/SMPP). In the present study, a comprehensive immune response data (33 cytokines) was obtained in school-age children (3-9 years old) during MPP, aiming to analyze the immune response patterns during MPP. At acute phase, changes of cytokines were both detected in GMPP (24/33) and SMPP (23/33) groups compared to the healthy group (p < 0.05), with 20 identical cytokines. Between MPP groups, the levels of 13 cytokines (IL-2, IL-10, IL-11, IL-12, IL-20, IL-28A, IL-32, IL-35, IFN-α2, IFN-γ, IFN-β, BAFF, and TSLP) were higher and three cytokines (LIGHT, OPN and CHI3L1) were lower in the SMPP group than in the GMPP group (p < 0.05). Function analysis reveals that macrophage function (sCD163, CHI3L1) are not activated in both MPP groups; difference in regulatory patterns of T cells (IL26, IL27, OPN, LIGHT) and defective activation of B cells (BAFF) were detected in the SMPP group compared to the GMPP group. Besides, the level of osteocalcin; sIL-6Rβ and MMP-2 are both decreased in MPP groups at acute and convalescent phases compared to the healthy group, among which the levels of sIL-6Rβ and MMP-2 showed negative correlations (p < 0.1) to the application of bronchial lavage in SMPP group, indicating their roles in the development of MPP. At the convalescent phase, more cytokines recovered in GMPP (18) than SMPP (11), revealing better controlled immune response during GMPP. These results reveal different immune response patterns during GMPP and SMPP. In addition, the differentiated cytokines may serve as potential indicators of SMPP; early intervention on immune response regulations may be helpful in reducing the severity of SMPP.

Recent Trend of Antimicrobial Susceptibility among Mycoplasma pneumoniae Isolated from Japanese Children

Macrolide-resistant Mycoplasma pneumoniae (MRMP) infections have become increasingly prevalent, especially in East Asia. Whereas MRMP strains have point mutations that are implicated in conferring resistance, monitoring the antibiotic susceptibility of M. pneumoniae and identifying mutations in the resistant strains is crucial for effective disease management. Therefore, we investigated antimicrobial susceptibilities among M. pneumoniae isolates obtained from Japanese children since 2011. To establish the current susceptibility trend, we analyzed the minimum inhibitory concentrations (MICs) of M. pneumoniae in recent years (2017−2020) in comparison with past data. Our observation of 122 M. pneumoniae strains suggested that 76 were macrolide-susceptible M. pneumoniae (MSMP) and 46 were macrolide-resistant. The MIC ranges (µg/mL) of clarithromycin (CAM), azithromycin (AZM), tosufloxacin (TFLX), and minocycline (MINO) to all M. pneumoniae isolates were 0.001−>128, 0.00012−>128, 0.25−0.5, and 0.125−4 µg/mL, respectively. None of the strains was resistant to TFLX or MINO. The MIC distributions of CAM and AZM to MSMP and MINO to all M. pneumoniae isolates were significantly lower, but that of TFLX was significantly higher than that reported in all previous data concordant with the amount of recent antimicrobial use. Therefore, continuation of appropriate antimicrobial use for M. pneumoniae infection is important.

Refractory Mycoplasma pneumoniae Pneumonia in Children: Early Recognition and Management

Refractory Mycoplasma pneumoniae pneumonia (RMPP) is a severe state of M. pneumoniae infection that has attracted increasing universal attention in recent years. The pathogenesis of RMPP remains unknown, but the excessive host immune responses as well as macrolide resistance of M. pneumoniae might play important roles in the development of RMPP. To improve the prognosis of RMPP, it is mandatory to recognize RMPP in the early stages, and the detection of macrolide-resistant MP, clinical unresponsiveness to macrolides and elevated proinflammatory cytokines might be clues. Timely and effective anti-mycoplasmal therapy and immunomodulating therapy are the main strategies for RMPP.

Recent Trends in the Epidemiology, Diagnosis, and Treatment of Macrolide-Resistant Mycoplasma pneumoniae

Among Mycoplasma pneumoniae (MP) is one of the major pathogens causing lower respiratory tract infection. Macrolide-resistant Mycoplasma pneumoniae (MRMP) isolates have been increasing and has become a global concern, especially in East Asian countries. This affects the treatment of MP infection; that is, some patients with MRMP infections fever cannot be controlled despite macrolide therapy. Therefore, alternative therapies, including secondary antimicrobials, including tetracyclines, fluoroquinolones, or systemic corticosteroids, were introduced. However, there are insufficient data on these alternative therapies. Thus, this article provides reviews of the recent trends in the epidemiology, diagnosis, and treatment of MRMP.

The investigation of P1 gene in Mycoplasma pneumonia isolated from atypic pneumonia by molecular methods, determine IgG antibody and MIC to ciprofloxacin antibiotic

Mycoplasma pneumoniae, which causes atypical pneumonia, is a well-established pathogen of the respiratory tract. This bacterium is intrinsically susceptible to fluoroquinolones. But recently, drug-resistant forms of this bacterium have been reported. This study aims to determine the prevalence of this bacterium by ELISA and PCR and MIC to ciprofloxacin. The clinical samples (blood and nasopharyngeal swab) were collected from 100 patients, who were referred to selective hospitals in Tehran with respiratory complaints, were enrolled in 2017. Nasopharyngeal swab sample collections were cultured on PPLO broth and PPLO agar. After culturing and DNA extraction, PCR was performed by specific P1 genes primers. Ciprofloxacin's MIC of Mycoplasma pneumonia isolated was determined by the Micro-broth dilution method. The serum of IgG antibody titers was also measured by ELISA Mycoplasma pneumonia. In this study, out of 100 samples, 12 bacteria were isolated on PPLO agar. Using specific primers, 7 samples of Mycoplasma speciesism-specific were positive for the presence of M.pneumoniae and 2 Ciprofloxacin resistant isolates were evaluated. ELISA results show that IgG titer antibody is existent in 19 samples and 5 samples are intermediate as well. IgG antibody titer average in the whole sample is 27/66 U/ml, but it is in Positive samples by P1 PCR is 45/75 U/ml. This study showed that PCR is a sensitive and reliable method for rapid detection of M. pneumoniae bacteria in respiratory infectious samples, but the results of this method are different from the ELISA method. Additionally, it seems that the resistance to ciprofloxacin is relatively common among M. pneumoniae.

Clinical features and risk factors analysis of bronchitis obliterans due to refractory Mycoplasma pneumoniae pneumonia in children: a nomogram prediction model

Background

Early prediction of bronchitis obliterans (BO) is of great significance to the improvement of the long-term prognosis of children caused by refractory Mycoplasma pneumoniae pneumonia (RMPP). This study aimed to establish a nomogram model to predict the risk of BO in children due to RMPP.

Methods

A retrospective observation was conducted to study the clinical data of children with RMPP (1–14 years old) during acute infection. According to whether there is BO observed in the bronchoscope, children were divided into BO and the non-BO groups. The multivariate logistic regression model was used to construct the nomogram model.

Results

One hundred and forty-one children with RMPP were finally included, of which 65 (46.0%) children with RMPP were complicated by BO. According to the multivariate logistic regression analysis, WBC count, ALB level, consolidation range exceeding 2/3 of lung lobes, timing of macrolides, glucocorticoids or fiber bronchoscopy and plastic bronchitis were independent influencing factors for the occurrence of BO and were incorporated into the nomogram. The area under the receiver operating characteristic curve (AUC-ROC) value of nomogram was 0.899 (95% confidence interval [CI] 0.848–0.950). The Hosmer–Lemeshow test showed good calibration of the nomogram (p = 0.692).

Conclusion

A nomogram model found by seven risk factor was successfully constructed and can use to early prediction of children with BO due to RMPP.

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.

Point-of-care molecular diagnosis of Mycoplasma pneumoniae including macrolide sensitivity using quenching probe polymerase chain reaction

Objectives

Macrolides are generally considered to be the drugs of choice for treatment of patients with Mycoplasma pneumoniae infection. However, macrolide-resistant M. pneumoniae has been emerging since about 2000. The Smart Gene^® system (MIZUHO MEDY Co., Ltd., Tosu, Japan) is a novel fully automated system for detection of pathogens using the method of quantitative polymerase chain reaction (qPCR) with QProbe (QProbe PCR). The entire procedure is completed within 50 min and the size of the instrument is small (15 x 34 x 30 cm). The purpose of this study was to evaluate the usefulness of the Smart Gene^® system for detection of M. pneumoniae and detection of a point mutation at domain V of the 23S rRNA gene of M. pneumoniae.

Materials

Pharyngeal swab samples were collected from 154 patients who were suspected of having respiratory tract infections associated with M. pneumoniae.

Results

Compared with the results of qPCR, the sensitivity and specificity of the Smart Gene^® system were 98.7% (78/79) and 100.0% (75/75), respectively. A point mutation at domain V of the 23S rRNA gene was detected from 7 (9.0%) of 78 M. pneumoniae-positive samples by the Smart Gene^® system and these results were confirmed by direct sequencing. The minimum inhibitory concentrations of clarithromycin among the 5 isolates of M. pneumoniae with a point mutation at domain V of the 23S rRNA gene were >64 μg/ml and those among the 33 isolates without a mutation in the 23S rRNA gene were <0.0625 μg/ml.

Conclusion

The Smart Gene^® system is a rapid and accurate assay for detection of the existence of M. pneumoniae and a point mutation at domain V of the 23S rRNA gene of M. pneumoniae at the same time. The Smart Gene^® system is suitable for point-of-care testing in both hospital and outpatient settings.

Macrolide Resistance, Clinical Features, and Cytokine Profiles in Taiwanese Children With Mycoplasma pneumoniae Infection

Background

The factors that predict the progression of Mycoplasma pneumoniae infection remain inconclusive. Therefore, we investigated macrolide resistance prevalence, M pneumoniae genotype, and clinical characteristics of childhood M pneumoniae respiratory tract infections in Taiwan.

Methods

A total of 295 children hospitalized with respiratory tract infections with positive serological M pneumoniae immunoglobulin M test results were enrolled in this 3-year prospective study. Oropharyngeal swabs were obtained for M pneumoniae cultures and polymerase chain reaction tests. All M pneumoniae specimens were further characterized by P1 typing, multilocus variable-number tandem-repeat analysis (MLVA), and macrolide resistance genotyping. The clinical characteristics and blood cytokine profiles were analyzed accordingly.

Results

Of 138 M pneumoniae specimens, type I P1 was the predominant (136 of 138, 98.6%). The MLVA type P (4-4-5-7-2) was the leading strain (42 of 138, 30.4%), followed by type J, U, A, and X. The overall macrolide-resistant rate was 38.4% (53 of 138); the resistance rate increased dramatically yearly: 10.6% in 2017, 47.5% in 2018, and 62.5% in 2019 (P < .001). All macrolide-resistant M pneumoniae (MRMP) harbored the A2063G mutation and were MLVA type 4-5-7-2 (49 of 53, 92.5%), especially type U and X. No significant differences in clinical symptoms, duration of hospital stay, and radiographic findings were identified among patients between MRMP and macrolide-sensitive M pneumoniae (MSMP) groups. Patients with MRMP infection had more febrile days before and during hospitalization and higher interleukin (IL)-13 and IL-33 levels than patients with MSMP infection (P < .05).

Conclusions

Macrolide-resistant M pneumoniae surged in Taiwan throughout the study period, but macrolide resistance was not a determinant factor of clinical severity.

Update on the Epidemiology of Macrolide-Resistant Mycoplasma pneumoniae in Europe: A Systematic Review

Macrolide-resistant Mycoplasma pneumoniae (MR-MP) infections cause upper and lower respiratory tract infections in both children and adults, and are characterized by a longer duration of symptoms. Here, we undertook a systematic review of studies on MR-MP in Europe. The review meets PRISMA guidelines. The PubMed, Scopus, and Science Direct databases were searched using suitable keywords to identify relevant studies published from 2010 to 2021; 21 studies were included. Overall, a low level of MR-MP spread was reported in Europe. MR-MP spread increased during epidemic waves registered in Europe, particularly in Italy and Scotland, where the highest MR-MP infection rates were registered during the 2010–2011 epidemic. By contrast, no MR-MP infections were reported in Finland and the Netherlands. Continued monitoring of MR-MP in Europe is needed to maintain the low rates of infection. Moreover, a coordinated and structured pan-European surveillance program adequate for public health surveillance is advisable, with the purpose of containing the spread of antimicrobial resistance.

Consideration in treatment decisions for refractory Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is the most common cause of childhood bacterial pneumonia. Although macrolide is known to be effective as a first-line therapy, the proportion of macrolide resistance in MP pneumonia has strikingly increased during recent 2 decades in East Asia. This is challenging to physicians since they have to decide more often whether to use secondary treatment. Diagnostic methods to detect macrolide-resistance of MP are currently not available in Korean hospitals. Even in the diagnosis of MP infection, both serologic and molecular test have limitation: inability to differentiate current illness from carriage or asymptomatic infection. Combining these 2 diagnostic methods and excluding infection caused by other respiratory pathogens allow a more reliable diagnosis. This effort is even more demanding in recent years to keep children from unnecessary exposure to secondary antibiotics. Although several observational studies have reported that tetracycline and fluoroquinolone, which are considered in the treatment of refractory MP pneumonia, have efficacy of shortening the duration of fever and respiratory symptoms, those findings need to be proven by well-designed prospective studies. The use of tetracycline and fluoroquinolone in children is generally tolerable, as supported by many observational data. However, since concerns about side effects still remain, careful consideration about benefits and risks is needed to decide their use.

Epidemiology and clinical manifestations of children with macrolide-resistant Mycoplasma pneumoniae pneumonia in Southern Taiwan

BACKGROUND

Mycoplasma pneumoniae is a pneumonia-causing pathogen commonly found in pediatric patients in Taiwan. Recently, macrolide-resistant (MR) strains have been emerging globally. The prevalence of pneumonia due to MR-M. pneumoniae (hereafter, MPP) in northern Taiwan before 2017 has been reported to be 12.3-24%. The prevalence of MR-MPP within a specific location can vary. Hence, we investigated the prevalence of MR-MPP in southern Taiwan.

METHODS

Eighty-one children with PCR-confirmed MPP were enrolled between July 2016 and June 2019. They were assigned to macrolide-sensitive (MS) and MR groups based on their PCR results, and their clinical manifestations and laboratory data were compared.

RESULTS

The proportions of patients with MS-MPP and MR-MPP varied with time. The average ratio of the proportion of MR-MPP was 54.3% in this study. Patients with MR-MPP had lower neutrophil counts, higher lymphocyte counts, and higher platelet counts than those with MS-MPP. In contrast with the 40% of the MR-MPP group that still had a fever after three days of azithromycin treatment, only 11.8% of the MS-MPP group still had a fever.

CONCLUSION

Our study provided valuable epidemiological survey information for children with MR-MPP in southern Taiwan. The prevalence of MR-MPP was different from that reported in previous studies in northern Taiwan. Specific MR strains should be considered in children with MPP if they still have a fever after three days of macrolide treatment.

Biocide-tolerance and antibiotic-resistance in community environments and risk of direct transfers to humans: Unintended consequences of community-wide surface disinfecting during COVID-19?

During the current pandemic, chemical disinfectants are ubiquitously and routinely used in community environments, especially on common touch surfaces in public settings, as a means of controlling the virus spread. An underappreciated risk in current regulatory guidelines and scholarly discussions, however, is that the persisting input of chemical disinfectants can exacerbate the growth of biocide-tolerant and antibiotic-resistant bacteria on those surfaces and allow their direct transfers to humans. For COVID-19, the most commonly used disinfecting agents are quaternary ammonium compounds, hydrogen peroxide, sodium hypochlorite, and ethanol, which account for two-thirds of the active ingredients in current EPA-approved disinfectant products for the novel coronavirus. Tolerance to each of these compounds, which can be either intrinsic or acquired, has been observed on various bacterial pathogens. Of those, mutations and horizontal gene transfer, upregulation of efflux pumps, membrane alteration, and biofilm formation are the common mechanisms conferring biocide tolerance in bacteria. Further, the linkage between disinfectant use and antibiotic resistance was suggested in laboratory and real-life settings. Evidence showed that substantial bacterial transfers to hands could effectuate from short contacts with surrounding surfaces and further from fingers to lips. While current literature on disinfectant-induced antimicrobial resistance predominantly focuses on municipal wastes and the natural environments, in reality the community and public settings are most severely impacted by intensive and regular chemical disinfecting during COVID-19 and, due to their proximity to humans, biocide-tolerant and antibiotic-resistant bacteria emerged in these environments may pose risks of direct transfers to humans, particularly in densely populated urban communities. Here we highlight these risk factors by reviewing the most pertinent and up-to-date evidence, and provide several feasible strategies to mitigate these risks in the scenario of a prolonging pandemic.

Usefulness of Q-probe PCR in Children with Mycoplasma pneumniae infection

To investigate the usefulness of quenching probe polymerase chain reaction (Q-probe PCR) for detection of macrolides-resistant Mycoplasma pneumoniae (MP), we retrospectively analyzed the clinical course of 21 children with MP infection. The rate of macrolides resistant MP was 66.7%. The duration of pyrexia after the initial antibiotics treatment was longer in patients with macrolides-resistant MP infection than in those with macrolides-sensitive MP infection. The duration of pyrexia after Q-probe PCR was not significantly different between patients with macrolides-resistant MP infection and those with macrolides-sensitive MP infection. These results suggest that antibiotic use based on Q-probe PCR will reduce duration of pyrexia. Q-probe PCR contributes to determine appropriate antibiotics and to improve the clinical course of MP infections.

Mutations in domain V of Mycoplasma pneumoniae 23S rRNA and clinical characteristics of pediatric M. pneumoniae pneumonia in Nanjing, China

OBJECTIVE

To investigate the prevalence of mutations in domain V of Mycoplasma pneumoniae (MP) 23S ribosomal RNA (rRNA) and the clinical characteristics of pediatric MP pneumonia (MPP) in Nanjing, China.

METHODS

Domain V of 23S rRNA was sequenced in MP strains collected from children diagnosed with MPP in Nanjing. Clinical and laboratory data were obtained.

RESULTS

Among the 276 MP strains, 255 (92.39%) harbored mutations, primarily A2063G in domain V of MP 23S rRNA. When children were stratified according to the presence or absence of mutations, no significant differences were found in sex, age, the MP DNA load at enrollment, lymphocyte counts, pulmonary complications, immunomodulator levels, fever duration, the duration of fever after macrolide therapy, and hospital stay. The prevalence of refractory MPP in the two groups was similar. Children with refractory MPP exhibited higher MP DNA loads than those with non-refractory MPP.

CONCLUSIONS

Despite the high prevalence of the A2063G mutation in domain V of MP 23S rRNA, mutations were not associated with the clinical characteristics of MPP. The MP DNA load significantly differed between refractory and non-refractory MPP.

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.

Emergent Pneumonia in Children

In recent decades there have been multiple pathogens, viruses and bacteria, which have emerged as causal agents of pneumonia affecting adults, albeit less frequently, to children. For the purposes of this article we have classified emerging pathogens as follows: True emerging, to pathogens identified for the very first time affecting human population (SARS-CoV-1, SARS-CoV-2, MERS-CoV, avian influenza, and hantavirus); Re-emerging, to known pathogens which circulation was controlled once, but they have reappeared (measles, tuberculosis, antimicrobial resistant bacteria such as CA-MRSA, Mycoplasma pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and new serotypes of post-vaccine pneumococcal); and finally, those that we have called old known with new presentations, including common pathogens that, in particular condition, have changed their form of presentation (rhinovirus, and non-SARS coronavirus). We will review for each of them their epidemiology, forms of presentation, therapy, and prognosis in children compared to the adult with the aim of being able to recognize them to establish appropriate therapy, prognostics, and effective control measures.

Molecular Detection and Evaluation of MLـ Resistance M. Pneumoniae Associated with Mutation in 23S RNA Gene among Iranian Patients with Respiratory Infections

Background

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia. The global increased resistance of M. pneumoniae strains to macrolide (ML) has become a worrisome health problem. The widespread use of these medications has led to increased rate of reported ML-resistant M. pneumoniae (MRMP) throughout the world. This study was aimed to evaluate the resistance of M. pneumoniae against erythromycin due to mutations in the 23S rRNA gene of patients with respiratory infections in Iran.

Methods

In this study, 100 samples of throat swab from a patient with respiratory problems were collected. After the cultured of all samples in M. pneumonia-specific PPLO medium, PCR technique was performed with specific primers. Afterwards, the broth micro-dilution MIC assay was employed. Finally, the PCR product of the 23S rRNA gene was sequenced to detect mutations of domain V in 23S rRNA gene of MRMP.

Results

It was found that 17 cases (17%) were positive for mycoplasma genus and six cases (6%) positive for M. pneumoniae species. Also, analysis of the sequence of 23S rRNA gene, revealed that one of the samples had mutations at positions A2431G and G2491A. All positive samples M. pneumoniae with 23S rRNA gene were sensitive to erythromycin.

Conclusion

These use of these antibiotics should be limited to prevent the emergence of MRMP in Iran.

Antibiotics for hospitalized children with community-acquired pneumonia in Japan: Analysis based on Japanese national database

INTRODUCTION

Community-acquired pneumonia (CAP) is one of the most common causes of pediatric infection requiring hospitalization. Antimicrobial resistance due to the inappropriate use poses a threat worldwide. Our objective is to analyze and optimize the trends of antibiotics used for pediatric inpatients with CAP in a claims database provided by the Ministry of Health, Labour and Welfare.

METHODS

Our database randomly sampled 10% of the hospitalized patients every October from 2011 to 2014. Patients aged <15 years in whom antibiotic therapy was initiated within two days of admission were listed. Subsequently, we investigated the antibiotics administered on the first day of prescription.

RESULTS

A total of 4,831 antibiotics were prescribed for 3,909 patients. Many patients aged ≤ five years were treated with β-lactams alone whereas many patients aged ≥ six years were treated with a single antibiotic, such as a macrolide, tetracycline, and quinolone, which covers atypical bacteria. Combination therapy was primarily used in children aged ≥ six years (nearly 30%); the main combination was a β-lactam and non-β-lactam covering atypical bacteria. Ampicillin-sulbactam was the most frequently prescribed β-lactam in children of all ages other than infants. Ampicillin, however, was most often prescribed in infants, but its usage rate was low at other ages.

CONCLUSIONS

Antibiotics were appropriately prescribed and were similar to that recommended in the 2011 guidelines for pediatric inpatients with CAP. However, combination therapy was frequently prescribed in children aged ≥ six years. According to the revised guidelines in 2017, ampicillin should be used more frequently for patients hospitalized with CAP.

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.

Rational stepwise approach for Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae is a common pathogen that causes community-acquired pneumonia. In the past, M. pneumoniae was sensitive to macrolide antibiotics, and M. pneumoniae pneumonia (MPP) was usually a benign and self-limiting disease. However, despite use of the appropriate antibiotics, persistent fever and clinical deterioration may occur, leading to severe disease. Two major complicated conditions that may be clinically encountered are macrolide-resistant MPP and refractory MPP. Regarding the epidemics in Taiwan, before 2017, the mean rate of macrolide resistance was below 30%. Notably, since 2018, the prevalence of macrolide-resistant MPP in Taiwan has increased rapidly. Macrolide-resistant MPP shows persistent fever and/or no radiological regression to macrolide antibiotics and may even progress to severe and complicated pneumonia. Tetracyclines (doxycycline or minocycline) or fluoroquinolones are alternative treatments for macrolide-resistant MPP. Refractory MPP is characterized by an excessive immune response against the pathogen. In this context, corticosteroids have been suggested as an immunomodulator for downregulating the overactive host immune reaction. Overuse of macrolides may contribute to macrolide resistance, and thereafter, an increase in macrolide-resistant MPP. Delayed effective antimicrobial treatment is associated with prolonged and/or more severe disease. Thus, the appropriate prescription of antibiotics, as well as the rapid and accurate diagnosis of MPP, is important. The exact starting point, dose, and duration of the immunomodulator are yet to be established. We discuss these important issues in this review.

Reactive infectious mucocutaneous eruption: Mycoplasma pneumoniae-induced rash and mucositis and other parainfectious eruptions

Mycoplasma pneumoniae-induced rash and mucositis is the most accurate diagnosis for patients with blistering mucocutaneous disease provoked by an infection. Recent literature suggests expansion of the name is required, as other infections have caused a clinically similar presentation. This review provides a concise update on current understanding of M. pneumoniae-induced rash and mucositis and other reactive infectious mucocutaneous eruptions.

Impact of viral coinfection and macrolide-resistant mycoplasma infection in children with refractory Mycoplasma pneumoniae pneumonia

Background

Cases of refractory Mycoplasma pneumoniae pneumonia have been increasing recently; however, whether viral coinfection or macrolide-resistant M. infection contribute to the development of refractory M. pneumoniae pneumonia remains unclear. This study aimed to investigate the impacts of viral coinfection and macrolide-resistant M. pneumoniae infection on M. pneumoniae pneumonia in hospitalized children and build a model to predict a severe disease course.

Methods

Nasopharyngeal swabs or sputum specimens were collected from patients with community-acquired pneumonia meeting our protocol who were admitted to Shanghai Children’s Medical Center from December 1, 2016, to May 31, 2019. The specimens were tested with the FilmArray Respiratory Panel, a multiplex polymerase chain reaction assay that detects 16 viruses, Bordetella pertussis, M. pneumoniae, and Chlamydophila pneumoniae. Univariate and multivariate logistic regression models were used to identify the risk factors for adenovirus coinfection and macrolide-resistant mycoplasma infection.

Results

Among the 107 M. pneumoniae pneumonia patients, the coinfection rate was 56.07%, and 60 (60/107, 56.07%) patients were infected by drug-resistant M. pneumoniae. Adenovirus was the most prevalent coinfecting organism, accounting for 22.43% (24/107). The classification tree confirmed that viral coinfection was more common in patients younger than 3 years old. Adenovirus coinfection and drug-resistant M. pneumoniae infection occurred more commonly in patients with refractory M. pneumoniae pneumonia (P = 0.019; P = 0.001). A prediction model including wheezing, lung consolidation and extrapulmonary complications was used to predict adenovirus coinfection. The area under the receiver operating characteristic curve of the prediction model was 0.795 (95% CI 0.679–0.893, P < 0.001). A prolonged fever duration after the application of macrolides for 48 h was found more commonly in patients infected by drug-resistant M. pneumoniae (P = 0.002). A fever duration longer than 7 days was an independent risk factor for drug-resistant Mycoplasma infection (OR = 3.500, 95% CI = 1.310–9.353, P = 0.012).

Conclusions

The occurrence of refractory M. pneumoniae pneumonia is associated with adenovirus coinfection and infection by drug-resistant M. pneumoniae. A prediction model combining wheezing, extrapulmonary complications and lung consolidation can be used to predict adenovirus coinfection in children with M. pneumoniae pneumonia. A prolonged fever duration indicates drug-resistant M. pneumoniae infection, and a reasonable change in antibiotics is necessary.

The Prevalence of 23S rRNA Mutations in ML-Resistant M. pneumoniae Isolates to Clarithromycin in Patients with Respiratory Infections

BACKGROUND

Mycoplasma pneumoniae is one of the widespread causes of community-acquired pneumonia (CAP). Over recent years, the widespread use of macrolides has led to the emergence of macrolide-resistant M.pneumoniae (MRMP) resulted from mutations at specific positions of domain V of the 23S rRNA gene.

METHODS

We collected 100 samples of throat swabs from patients with respiratory infections. After extraction of DNA from bacterial cell cultured in PPLO broth media using Roche kit (Germany), the PCR was performed on specific samples of M. pneumoniae using specific primers for 23S rRNA gene.Afterwards, for positive samples, minimum inhibitory concentration (MIC) was determined using the broth microdilution with Clarithromycin. Finally, the PCR product was sequenced to detect mutations related to macrolide resistance in domain V of 23S rRNA .

RESULTS

According to the analysis of the sequenced PCR product of M. pneumoniae 23S rRNA gene using Clustalw2 online software, one of the samples were shown to have a mutation at A2431G and G2491A positions. The MIC measurement also revealed that all isolates were sensitive to Clarithromycin, and there was no macrolide resistance to Clarithromycin in all isolates.

CONCLUSION

Sequence analysis of the 23S rRNA gene in M. pneumoniae , revealed no macrolide resistance of M. pneumoniae to Clarithromycin. Thus, the use of these antibiotics should be restricted to prevent the development of macrolide-resistant M. pneumoniae in Iran.

Ameliorative effect of Albizia chinensis synthesized ZnO-NPs on Mycoplasma pneumoniae infected pneumonia mice model

BACKGROUND

Mycoplasma pneumoniae (MP) is a common cause of community-acquired pneumonia (CAP) among the children and adults that results upper and lower respiratory tract infections.

OBJECTIVE

This study was aimed to inspect the ameliorative action of A. chinensis synthesized ZnONPs against M. pneumoniae infected pneumonia mice model.

MATERIALS AND METHODS

ZnO NPs was synthesized from Albizia chinensis bark extract and characterized by UV-Vis spectroscopy, Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), energy dispersive X-ray (EDX) and atomic force microscope (AFM) analyses. The antibacterial effectual of synthesized ZnONPs were examined against clinical pathogens. The pneumonia was induced to BALB/c mice via injecting the M. pneumoniae and treated with synthesized ZnONPs, followed by the total protein content, total cell counts and inflammatory mediators level was assessed in the BALF of experimental animals. The Histopathological investigation was done in the lung tissues of test animals.

RESULTS

The outcomes of this work revealed that the formulated ZnONPs was quasi-spherical, radial and cylindrical; the size was identified as 116.5 ± 27.45 nm in diameter. The in vitro antimicrobial potential of formulated ZnO-NPs displayed noticeable inhibitory capacity against the tested fungal and bacterial strains. The administration of synthesized ZnO-NPs in MP infected mice model has significantly reduced the levels of total protein, inflammatory cells, inflammatory cytokines such as IL-1, IL-6, IL-8, tumour necrosis factor-alpha (TNF-a) and transforming growth factor (TGF). Besides, the histopathological examination of MP infected mice lung tissue showed the cellular arrangements were effectively retained after administration of synthesized ZnO-NPs.

CONCLUSION

In conclusion, synthesized ZnO-NPs alleviate pneumonia progression via reducing the level of inflammatory cytokines and inflammatory cells in MP infected mice model.

Allele-specific real-time PCR testing for minor macrolide-resistant Mycoplasma Pneumoniae

Background

The point mutations in 23S rRNA gene of Mycoplasma pneumoniae (M. pneumoniae) can lead to high-level resistance to macrolides. This study aimed to evaluate allele-specific real-time PCR (ASPCR) to detect the resistance-related mutations located at positions A2063G and A2064G of 23S rRNA gene.

Methods

We detected 178 pharyngeal swab specimens and calculated the proportions of resistant and sensitive quasispecies using ASPCR assays. ASPCR assays can detect down to 10 copies of 23S rRNA gene and achieved sensitivities of < 0.1% for A2063G and A2064G. We also compared the findings of ASPCR with the results of nested PCR with sequencing.

Results

Of 178 samples, 164 were found to have M. pneumoniae including 90.85% (149/164) samples with macrolide-resistant M. pneumoniae (MRMP) quasispecies by ASPCR, while 153 were found to be M. pneumoniae-positive including 71.90% (110/153) samples with MRMP quasispecies by nested PCR with sequencing. Of the 164 M. pneumoniae-positive samples, 61.59% (101/164) had the mixed population of wild-type and mutant M. pneumoniae, and 56.44% (57/101) of the latter contained the mutations at low frequency (≤50%).

Conclusion

ASPCR indicated that sensitive and resistant quasispecies coexisted in most of the M. pneumoniae positive samples. The ASPCR was a highly sensitive, accurate and rapid method for detecting the macrolide resistance-associated mutations and it could provide earlier and more drug-resistant information for M. pneumoniae research and the clinical therapy.

&lt;italic&gt;Mycoplasma Pneumoniae&lt;/italic&gt;-Associated Necrotizing Pneumonia in Children: a case-report

<p>Mycoplasma pneumoniae is the most common bacterial strain causing atypical pneumonia in children and adolencents. Although it is known to cause mild symptoms, it can also cause severe pulmonary or extrapulmonary complications in rare cases. Necrotizing pneumonia (NP) is often reported as a complication of Streptococcus pneumoniae and is very rarely caused by M. pneumoniae. We report a case in which a 5-year-old boy was diagnosed with lobar pneumonia with symptoms that aggravated even with macrolide antibiotic treatment. Anti-mycoplasma pneumoniae Ig-M test yielded high values, and direct polymerase chain reaction results were also positive. NP caused by M. pneumoniae was confirmed on computed tomography. After treatment involving tosufloxacin and systemic steroid, the lesion decreased in size and improved gradually when followed-up for more than 1 year. The patient did not have any predisposing or risk factors for NP.</p>