The study of routine laboratory factors in children with mycoplasma pneumoniae pneumonia: serum uric acid may have anti-inflammatory effect.

BACKGROUND: High uric acid levels are a risk factor for cardiovascular disorders, and metabolic diseases; however, the role of serum uric acid (sUA) during the mycoplasma pneumoniae pneumonia (MPP) of children is poorly known. This study aimed to clarify the effects of sUA during the MPP of children. METHODS: This was a prospective cohort study of children with MPP from multi-center inpatient departments from September 2019 to August 2020. Routine laboratory characteristics analyzed including ALT, AST, BUN, CREA, UA, LDH, CK-MB, WBC, N%, PLT, and CRP. Subjects were divided into 3 groups: non-MPP, mild MPP (MMPP), and severe MPP (SMPP). RESULTS: 949 subjects were enrolled, including 207 in non-MPP, 565 in MMPP, and 177 in SMPP. The optimal cutoff value for sUA is 239 µmmol/L in receiver operating characteristic (ROC) curves analysis. Multivariate logistic regression showed that WBC and sUA had significance for protective effects between non-MPP and SMPP, but CRP did not have significance between the two groups, N and PLT had significance for risk factors; WBC and sUA did not have significance for the protective effects between non-MPP and MMPP, CRP had significance between the two groups, N and PLT had significance for the risk effects. Similarly, binary logistic regression showed UA, WBC, and CRP had significance for the protective effects between non-MPP and MPP, but N and PLT had significance for the risk effects between the two groups. CONCLUSION: Both multivariate and binary logistic regression demonstrated that sUA displayed a protective effect during the MPP of children, which meant sUA is anti-inflammatory.

The Value of High-Sensitivity C-reactive Protein in Evaluating Myocardial Damage and the Prognosis in Children with Mycoplasmal Pneumonia.

OBJECTIVE: To investigate the value of high-sensitivity C-reactive protein (hs-CRP) in evaluating the myocardial damage and prognosis in children with mycoplasmal pneumonia. MATERIALS: A total of 150 children with mycoplasmal pneumonia were selected. According to their serum creatine kinase isoenzyme (CK-MB) level, they were divided into 72 cases of the myocardial damage group and 78 cases of the non-myocardial damage group. Eighty healthy children undergoing physical examination were selected as the control group. The electrocardiography results and serum CK-MB and hs-CRP levels were compared among the subjects. The correlations among the above indexes were analyzed. RESULTS: The levels of hs-CRP and CK-MB in the myocardial damage group were significantly higher than those in the nonmyocardial damage group and control group, respectively (P<0.05). The rates of abnormal hs-CRP and abnormal electrocardiogram in the myocardial damage group were significantly higher than those in the non-myocardial damage group, respectively (P<0.05). In the 150 children with mycoplasmal pneumonia, the serum hs-CRP and CK-MB levels were positively correlated (P<0.001), and the abnormal hs-CRP rate was positively correlated with the abnormal electrocardiogram rate (P<0.001). In the myocardial damage group, the serum levels of hs-CRP and CK-MB after treatment were significantly lower than those before treatment, respectively (P<0.05). After treatment, each index in the myocardial damage group had no significant difference with those in the control group (P>0.05). CONCLUSION: hs-CRP may be an important index for evaluating the myocardial damage and prognosis in children with mycoplasmal pneumonia. The combination of hs-CRP and CK-MB detection has obvious guiding significance for the monitoring and treatment of mycoplasmal pneumonia complicated by myocardial damage.

Prediction of risk factors of bronchial mucus plugs in children with Mycoplasma pneumoniae pneumonia.

BACKGROUND: Recently, many cases of pneumonia in children with Mycoplasma pneumoniae infection have been shown to have varying degrees of intrabronchial mucus plug formation. The clinical, laboratory, radiological characteristics, and treatment of patients with Mycoplasma infection are analyzed in this study. The risk factors for M. pneumoniae pneumonia (MPP) mucus plug formation in children are explored, and a risk factor scoring system is established. METHODS: MPP patients treated with bronchoscopy were retrospectively enrolled in the study from February 2015 to December 2019. The children were divided into a mucus plug group and a control group according to the presence or absence of mucus plug formation. The clinical, laboratory, radiological characteristics, and treatment of the two groups of children were compared. Univariate and multivariate logistic regression models were used to identify the risk factors for MPP mucus plug formation. The receiver operating characteristic (ROC) curve was drawn to evaluate the regression model and establish the MPP mucous plug risk factor scoring system. RESULTS: A univariate analysis showed that the children in the mucous group were older and had a longer fever duration, longer hospital stay, higher fever peak, more cases of wheezing symptoms and allergies, and azithromycin or corticosteroids were administered later. In addition, neutrophil, C-reactive protein (CRP), lactate dehydrogenase (LDH), D-dimer (DD), sputum MP-DNA copy number, and total immunoglobulin A (IgA) levels were higher, while prealbumin (PA) levels were lower. The ROC curve analysis showed that children with MPP had PA ≤144.5 mg/L, had used corticosteroids during the course of the illness of ≥4.5 days, CRP ≥12.27 mg/L, an LDH ≥ 462.65 U/L, and there was a possibility of intra-airway mucus formation. The independent risk factors were scored according to their odds ratio (OR) value. Among the 255 children with MPP, the high-risk group had 44 (83.02%) mucus plugs out of 53; the middle-risk group had 35 (34.3%) mucus plugs out of 102; and the low-risk group had 11 (11%) mucus plugs out of 100. CONCLUSIONS: PA levels, timing of corticosteroid use (use in the first few days), CRP levels, and LDH levels were independent risk factors for MPP mucus plug formation. This provides a basis for the early identification of MPP in children combined with mucus plug formation.

Effects of a combination of erythromycin sequential therapy and azithromycin on lung function and inflammatory factors in children with severe mycoplasma pneumonia.

This study aimed to investigate the effect of erythromycin sequential therapy plus azithromycin on lung function and inflammatory factors in children with severe mycoplasma pneumonia (MP). Ninety-three severe MP children were selected and randomized into azithromycin group, erythromycin group, and combination group, 31 cases in each. The disappearance time of cough, fever, lung rale and X-ray shadow in the combination group were shorter than those in the azithromycin group and erythromycin group. The clinical treatment efficiency of the combination group was higher than that of the azithromycin group. After treatment, FVC, FEV1/FVC and PEF in combination group were higher than before treatment; IL-8, IL-6, CRP in combination group were lower than erythromycin group and azithromycin group. IL-8, IL-6, CRP are negatively correlated with disappearance time of cough, fever, pulmonary rale, X-ray shadow and clinical treatment efficiency; FEV1/FVC is positively correlated with disappearance time of cough and fever, pulmonary rales and X-ray shadow, and clinical treatment efficiency. Sequential erythromycin therapy combined with azithromycin in the treatment of MP can effectively inhibit high inflammatory reactions, control the disease in a timely manner, improve lung function and produce fewer adverse reactions.

Effect of Qingfei Huatan Huoxue Decoction combined with azithromycin on pulmonary function and inflammatory factors in children with Mycoplasma pneumonia.

To investigate the effect of Qingfei Huatan Huoxue Decoction combined with azithromycin on pulmonary function and inflammatory factors in children with Mycoplasma pneumonia. A total of 155 children with Mycoplasma pneumonia of toxic heat blocking lung syndrome were randomly divided into the control group (n=77) and the observation group (n=78) from March 2020 to March 2021. Both groups of children were given conventional treatment and azithromycin intravenous drip and the observation group was additionally given oral administration of Qingfei Huatan Huoxue Decoction, with 7 days as a course of treatment totaling 2 courses. The lung function, inflammatory factor level, immune function and coagulation function were compared between the two groups before and after treatment. After treatment, the symptom integral of fever, cough and pulmonary wet rales in the two groups were reduced, while FEV1, PEF and FEV1/ FVC were significantly increased, serum TNF-α, IFN- γ and IL-6 were significantly reduced, the levels of Immunoglobulin M (IgM), IgG and IgA were significantly reduced and plasma PT and APTT were significantly reduced, with more significant changes observed in the observation group (all P<0.05). The disappearance time of fever, cough and pulmonary moist rales in the observation group was significantly shorter than that in the control group (P<0.05). The recovery rate of the observation group was significantly higher than that of the control group (P<0.05). Qingfei Huatan Huoxue Decoction combined.

A case report of severe mycoplasma pneumonia with autoimmune haemolytic anaemia.

Mycoplasma pneumonia is a common cause of respiratory disease and more so in school going children. The spectrum of the manifestations range from haematological, dermatological, neurological, musculoskeletal, renal, cardiac and also gastrointestinal. The treatment approach has varied over time. In this report we would like to share our experience in a case of M.pneumonia with autoimmune haemolytic anaemia (AIHA).

Bronchoalveolar lavage T cell cytokine profiles and their association with lung function in children with Mycoplasma pneumoniae -associated bronchiolitis obliterans.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) infection may progress to bronchiolitis obliterans (BO), with an underlying chronic inflammatory process. The aim of this study was to investigate the cytokine profiles in pulmonary T-lymphocytes and their associations with lung function in patients with BO following M. pneumoniae infection. METHODS: Bronchoalveolar lavage (BAL) samples were obtained from 10 controls and 18 children with M. pneumoniae-associated BO. We analyzed the BAL T cells for interferon (IFN)-γ, interleukin (IL)-4, IL-9, IL-17, CD25, and Foxp3 by intercellular flow cytometry. The associations with T-cell subpopulations and lung function parameters were determined. RESULTS: In BAL fluid, significantly increased proportions of T-helper 1 (Th1), Th17, and Tc1 cells were found in M. pneumoniae-associated BO patients when compared with controls. The percentages of Th17 cells showed correlations with forced expiratory volume in 1 second % predicted value (r = -0585; P < .05) and forced expiratory flow at 25% to 75% (FEF25%-75% ) % predicted value (r = -.618; P < .01). Higher proportions of Tc1 (r = -.488; P < .05) and Tc17 (r = -.542; P < .05) were significantly correlated with a reduced FEF25%-75% % predicted value in M. pneumoniae-associated BO patients. CONCLUSIONS: Our comprehensive cytokines analysis of BAL T cells revealed correlations of IL-17-producing and IFN-γ-producing T cells with lung function, suggesting that increased T-cell subpopulations may play a role in M. pneumoniae-associated BO progression.

Human adenovirus Coinfection aggravates the severity of Mycoplasma pneumoniae pneumonia in children.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is an important pathogen of community-acquired pneumonia (CAP) in children. The coinfection rate of M. pneumoniae pneumonia (MPP) can reach 52% in some areas, but the effects of coinfection with different pathogens have not been clearly recognized. METHODS: The cases of MPP hospitalized in Beijing Children's Hospital from 1/1/2014 to 12/31/2016 were screened. MPP patients coinfected with Human adenovirus (HAdV) were categorized into the research group. Patients with single M. pneumoniae infection were categorized into the control group, matching the research group by age and admission time with a ratio of 1:3. Clinical manifestations, laboratory examinations, and disease severity were compared between these two groups. RESULTS: A total of 2540 hospitalized MPP cases were screened in Beijing Children's Hospital, among which thirty cases were enrolled in the research group and ninety cases were enrolled in the control group. The results indicated that patients in the research group had longer hospital stays, longer fever durations and a higher rate of dyspnea, as well as a larger proportion applications of oxygen therapy and noninvasive continuous positive airway pressure (NCPAP). No obvious differences were found in lab examinations within the two groups. Regarding disease severity, the proportions of extremely severe pneumonia and severe disease defined by the clinical score system were higher in the research group than in the control group. CONCLUSION: Compared with single M. pneumoniae infection, MPP coinfected with HAdV in children was relatively more serious.

Presenting characteristics, comorbidities, and outcomes of patients coinfected with COVID-19 and Mycoplasma pneumoniae in the USA.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is spreading at a rapid pace, and the World Health Organization declared it as pandemic on 11 March 2020. Mycoplasma pneumoniae is an "atypical" bacterial pathogen commonly known to cause respiratory illness in humans. The coinfection from SARS-CoV-2 and mycoplasma pneumonia is rarely reported in the literature to the best of our knowledge. We present a study in which 6 of 350 patients confirmed with COVID-19 were also diagnosed with M. pneumoniae infection. In this study, we described the clinical characteristics of patients with coinfection. Common symptoms at the onset of illness included fever (six [100%] patients); five (83.3%) patients had a cough, shortness of breath, and fatigue. The other symptoms were myalgia (66.6%), gastrointestinal symptoms (33.3%-50%), and altered mental status (16.7%). The laboratory parameters include lymphopenia, elevated erythrocyte sedimentation rate, C-reactive protein, lactate dehydrogenase, interleukin-6, serum ferritin, and D-dimer in all six (100%) patients. The chest X-ray at presentation showed bilateral infiltrates in all the patients (100%). We also described electrocardiogram findings, complications, and treatment during hospitalization in detail. One patient died during the hospital course.

A plethora of manifestations following a Mycoplasma pneumoniae infection: a case report.

Mycoplasma pneumoniae infection can present with a plethora of symptoms and result in a systemic vasculitis by activating a cascade of autoimmune reactions. In this case report, a young man without relevant past medical history was admitted to the hospital with diarrhea, abdominal pain and spiking fever. A CT-scan showed terminal ileitis. A 5-day broad spectrum antibiotic treatment (ciprofloxacin/clindamycin) did not result in any clinical improvement. On the contrary, the patient developed a cholestatic hepatitis, bilateral anterior uveitis and a dry cough. Extensive serological testing finally led to the diagnosis of a M. pneumoniae infection by paired serology (≥4-fold rise in IgG titer). In the diagnostic work-up, a PET-CT was performed and showed increased tracer uptake in the carotids and vertebral arteries, suggesting the diagnosis of vasculitis. After start of azithromycin and low-dose corticosteroids (0.5 mg/kg/day), a gradual clinical and biochemical improvement was observed. But subsequently, the patients relapsed and presented with an acute coronary syndrome. Coronary angiography revealed aneurysmatic deformation of the three coronary arteries, leading to the assumption of coronary vasculitis. Clinical improvement was achieved with high-dose corticosteroids (1 mg/kg/day). This case shows that M. pneumoniae is not merely a pulmonary infection, but that its primary symptoms can be diverse and misleading. All clinicians should be aware of its extrapulmonary manifestations.

The diagnostic value of serological studies in pediatric patients with acute Mycoplasma pneumoniae infection.

BACKGROUND: Mycoplasma pneumoniae is a common pathogen of respiratory tract infections in pediatric patients. Serological studies are traditional methods for the diagnosis. However, early diagnosis of M. pneumoniae infections remains problematic. We investigate the value of early serum immunoglobulin A (IgA), in addition to immunoglobulin G (IgG), and immunoglobulin M (IgM) levels, in children infected with M. pneumoniae. METHODS: From August 2016 to February 2017, we enrolled pediatric patients based on both clinical symptoms and chest x-ray, and confirmed by positive throat culture for M. pneumoniae. Serum titers of M. pneumoniae IgM, IgG, and IgA during the acute phase were checked. All respiratory samples were further analyzed by polymerase chain reaction (PCR). Diagnostic values of different tests were evaluated. RESULTS: Fifty-six patients fulfilled the diagnostic criteria, with a median age of 4.84 years. Most of them (89.3%) were enrolled within 7 days of disease onset. PCR was positive in 71.4% of the study population. Early IgG samples were of limited value in diagnosing M. pneumoniae infection, of which 89.3% showed a negative result. Positive rates of early serum IgA and IgM were 48.2% and 46.4%, respectively. In combination with IgA and/or IgM, the sensitivity increased to 71.4% during their early clinical course. CONCLUSIONS: In the pediatric population, combined serological tests of M. pneumoniae IgA and IgM, offer an accurate method of early diagnosis comparable to that of PCR, and can be an alternative choice for prompt detection of mycoplasma infections when PCR and culture are not available.

High expression of miR-222-3p in children with Mycoplasma pneumoniae pneumonia.

OBJECTIVES: Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia in children. However, its mechanism of pathogenesis is not fully understood, and microRNAs might play a role. This study aimed to explore the microRNA-222-3p (miR-222-3p) expression and its possible role in children with M.pneumoniae pneumonia (MPP). METHODS: Thirty-six children with MPP and twenty-seven age-matched controls from Children's Hospital of Soochow University were enrolled in this study. MiR-222-3p and cluster of differentiation 4 (CD4) mRNA were detected using real-time PCR in children's peripheral blood plasma samples. THP-1 cells and mice were stimulated with M.pneumoniae lipid-associated membrane proteins(LAMPs). RESULTS: Children with MPP had significantly higher levels of miR-222-3p and lower levels of CD4 in peripheral blood plasma (P <  0.05). Additionally, Sixteen children with MPP complicated with pleural effusion had higher miR-222-3p levels than those without pleural effusion. MiR-222-3p or CD4 in THP-1 cells increased or decreased, respectively, in a dose dependent manner after LAMP stimulation. In LAMP-stimulated mice massive inflammatory cells infiltrates surrounded the bronchioles, and miR-222-3p increased in the bronchoalveolar lavage fluid. In conclusion, miR-222-3p was highly expressed in children with MPP, especially those with pleural effusion. CONCLUSION: Small sample studies showed that M.pneumoniae or its LAMPs could increase miR-222-3p and decrease CD4 in macrophages,both in vitro and vivo.Thus, miR-222-3p might be an MPP biomarker for the diagnosis and prognosis.

Epidemiological relationship between Mycoplasma pneumoniae pneumonia and recurrent wheezing episode in children: an observational study at a single hospital in Korea.

OBJECTIVE: This study was aimed to evaluate epidemiological and clinical relationship between Mycoplasma pneumoniae (MP) infection and childhood recurrent wheezing episode (RWE). DESIGN: Retrospective case note review. SETTING: Paediatric department at a single Korean institution. PARTICIPANTS: Consecutive admitted patients with MP pneumonia and RWE (0-15 years of age) between 2003 and 2014. METHODS: The retrospective medical records of patients with (MP) pneumonia (n=793 for epidemiological analysis and n=501 for clinical analysis) and those with RWE (n=384) from 2003 to 2014 were analysed. Diagnosis of MP pneumonia was made based on two-times titration of IgM antibody during hospitalisation. An RWE patient was defined as one with expiratory wheezing with at least one or more wheezing episodes based on medical records. RESULTS: During three MP pneumonia epidemics, there were no corresponding increases of patients with RWE in the epidemic years. In the 501 MP pneumonia patients, 52 (10.4%) had wheezing at presentation and 15 (3%) had RWE. The MP pneumonia patients with wheezing at presentation (n=52) were younger and were more likely to have an allergic disease history than those without wheezing (n=449). Among wheezing patients at presentation, 10 patients had previously RWE history. In a follow-up study, 13 patients (including 5 RWE) with initial wheezing and 25 patients (including 2 RWE) without wheezing had wheezy episodes after discharge. Among the total 501 patients, it was estimated that at least 31 MP pneumonia patients (6.2%) showed recurrent wheezing after initial MP infection. CONCLUSIONS: A small part of children with MP pneumonia showed recurrent wheezing after MP pneumonia, and patients with RWE had a greater likelihood of experiencing wheezing when they had an initial MP infection. However, there were no increased admitted patients with RWE in MP pneumonia epidemic periods because of rarity of MP reinfection in children including patients with RWE or asthma.

A pilot study of the effects of Mycoplasma ovipneumoniae exposure on domestic lamb growth and performance.

Mycoplasma ovipneumoniae is a globally distributed pathogen that has been associated with pneumonia in both domestic and wild Caprinae. It is closely related to M. hyopneumoniae, a respiratory pathogen of swine that is associated with decreased growth rates of pigs as well as clinical respiratory disease. In order to assess the effects of M. ovipneumoniae on lamb performance, we generated a cohort of lambs free of M. ovipneumoniae by segregation of test negative ewes after lambing, then compared the growth and carcass quality traits of M. ovipneumoniae-free and -colonized lambs from weaning to harvest. Some signs of respiratory disease were observed during the feeding trial in both lamb groups, but the M. ovipneumoniae-exposed group included more affected lambs and higher average disease scores. At harvest, lungs of lambs in both groups showed few grossly visible lesions, although the M. ovipneumoniae-exposed group did exhibit increased microscopic lung lesions (P<0.05). In addition, M. ovipneumoniae exposed lambs produced lower average daily gains (P<0.05), and lower yield grade carcasses (P<0.05) compared to those of non-exposed lambs. The results demonstrated the feasibility of test and segregation for elimination of M. ovipneumoniae from groups of sheep and suggested that this pathogen may impair lamb growth and productivity even in the absence of overt respiratory disease.

Allergic airway sensitization impairs antibacterial IgG antibody responses during bacterial respiratory tract infections.

BACKGROUND: Mycoplasma pneumoniae, an atypical human pathogen, has been associated with asthma initiation and exacerbation. Asthmatic patients have been reported to have higher carriage rates of M pneumoniae compared with nonasthmatic subjects and are at greater risk for invasive respiratory infections. OBJECTIVE: We sought to study whether prior allergen sensitization affects the host response to chronic bacterial infection. METHODS: BALB/cJ and IL-4 receptor α-/- mice were sensitized with ovalbumin (OVA) and then infected with M pneumoniae or Streptococcus pneumoniae. Immune parameters were analyzed at 30 days postinfection and included cellular profiles in bronchoalveolar lavage fluid (BALF) and serum IgG and IgE antibody levels to whole bacterial lysate, recombinant P1 adhesin, and OVA. Total lung RNA was examined for transcript levels, and BALF was examined for cytokine protein profiles. RESULTS: Anti-M pneumoniae antibody responses were decreased in allergen-sensitized, M pneumoniae-infected animals compared with control animals, but OVA-specific IgG responses were unaffected. Similar decreases in anti-S pneumoniae antibody levels were found in OVA-sensitized animals. However, M pneumoniae, but not S pneumoniae, infection augmented anti-OVA IgE antibody responses. Loss of IL-4 receptor signaling partially restored anti-M pneumoniae antibody responses in IgG2a and IgG2b subclasses. Inflammatory cytokine levels in BALF from OVA-sensitized, M pneumoniae-infected or S pneumoniae-infected animals were reduced compared with those in uninfected OVA-sensitized control animals. Unexpectedly, airway hyperreactivity to methacholine was essentially ablated in M pneumoniae-infected, OVA-sensitized animals. CONCLUSIONS: An established type 2-biased host immune response impairs the host immune response to respiratory bacterial infection in a largely pathogen-independent manner. Some pathogens, such as M pneumoniae, can augment ongoing allergic responses and inhibit pulmonary type 2 cytokine responses and allergic airway hyperreactivity.

Bovine Epithelial in vitro Infection Models for Mycoplasma bovis.

Mycoplasma bovis causes bovine mycoplasmosis. The major clinical manifestations are pneumonia and mastitis. Recently an increase in the severity of mastitis cases was reported in Switzerland. At the molecular level, there is limited understanding of the mechanisms of pathogenicity of M. bovis. Host-pathogen interactions were primarily studied using primary bovine blood cells. Therefore, little is known about the impact of M. bovis on other cell types present in infected tissues. Clear in vitro phenotypes linked to the virulence of M. bovis strains or tissue predilection of specific M. bovis strains have not yet been described. We adapted bovine in vitro systems to investigate infection of epithelial cells with M. bovis using a cell line (MDBK: Madin-Darby bovine kidney cells) and two primary cells (PECT: bovine embryonic turbinate cells and bMec: bovine mammary gland epithelial cells). Two strains isolated before and after the emergence of severe mastitis cases were selected. Strain JF4278 isolated from a cow with mastitis and pneumonia in 2008 and strain L22/93 isolated in 1993 were used to assess the virulence of M. bovis genotypes toward epithelial cells with particular emphasis on mammary gland cells. Our findings indicate that M. bovis is able to adhere to and invade different epithelial cell types. Higher titers of JF4278 than L22/93 were observed in co-cultures with cells. The differences in titers reached between the two strains was more prominent for bMec cells than for MDBK and PECT cells. Moreover, M. bovis strain L22/93 induced apoptosis in MDBK cells and cytotoxicity in PECT cells but not in bMec cells. Dose-dependent variations in proliferation of primary epithelial cells were observed after M. bovis infection. Nevertheless, an indisputable phenotype that could be related to the increased virulence toward mammary gland cells is not obvious.

[Clinical features and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children].

OBJECTIVE: To study the clinical features of macrolide-resistant Mycoplasma pneumoniae pneumonia and its treatment regimens in children. METHODS: The samples of throat swab or bronchoalveolar lavage fluid were collected from 136 children with Mycoplasma pneumoniae pneumonia. Quantitative real-time PCR was used to detect 2063/2064 A:G mutation in 23S rRNA, and according to such results, the children were divided into drug-resistance group with 81 children and sensitive group with 55 children. The two groups were compared in terms of age composition, respiratory symptoms, extrapulmonary complications, laboratory markers, imaging changes, treatment regimens, and length of hospital stay. RESULTS: Compared with the sensitive group, the drug-resistance group had significantly longer duration of pyrexia and severe fever, a significantly higher percentage of children with reduced blood oxygen saturation, and significantly higher levels of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) (P<0.05). The conventional azithromycin treatment had a good clinical effect in the sensitive group, while corticosteroid therapy was usually needed in the drug-resistance group. CONCLUSIONS: Macrolide-resistant Mycoplasma pneumoniae infection cannot be identified based on a single clinical feature, but prolonged duration of pyrexia and severe fever, reduced blood oxygen saturation, and increased ALT and LDH can suggest the presence of this disease. Azithromycin combined with glucocorticoids may be a good treatment regimen for children with macrolide-resistant Mycoplasma pneumoniae pneumonia.

Correlation between clinical features, high-resolution computed tomography findings, and a visual scoring system in patients with pneumonia due to Mycoplasma pneumoniae.

BACKGROUND: Mycoplasma pneumoniae (MP) is the primary cause of community-acquired pneumonia. We aimed to evaluate the correlation between clinical features, with special reference to hypoxemia and the total affected area obtained using high-resolution computed tomography (HRCT). METHODS: Medical records of MP pneumonia patients > 15 years of age at Kyorin University Hospital between January 2006 and November 2013 were reviewed retrospectively and compared to patients with Streptococcus pneumoniae pneumonia, diagnosed between January 2013 and September 2014. RESULTS: We identified 65 and 32 patients with MP- and S. pneumoniae pneumonia, respectively. HRCT data were available for 42 and 32 patients with MP- and S. pneumoniae pneumonia, respectively. Data were available for all hypoxemic patients. Hypoxemia was significantly higher in patients with S. pneumoniae (14/32, p = 0.008) than those with MP (5/39). Total visual score on HRCT correlated significantly with hypoxemia in both groups, but showed significantly higher scores with MP- than with S pneumoniae pneumonia in hypoxemic patients. MP pneumonia showed significant positive correlation between the total visual score and serum inflammatory markers (C-reaction protein [r = 0.43, p = 0.025] and lactate dehydrogenase [r = 0.466, p = 0.016]). In both groups, individual scores in the middle and lower lung fields were significantly higher than in the upper field, suggesting zonal predominance. CONCLUSIONS: This study provides the first evidence that the total affected area on lung HRCT was more with MP compared to S. pneumoniae pneumonia in hypoxemic patients and positively correlated with hypoxemia and serum inflammatory markers.

Clinical manifestations in infants and children with Mycoplasma pneumoniae infection.

BACKGROUND: Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in older children. Pulmonary and extra-pulmonary symptoms associated with M. pneumoniae infection are reported. M. pneumoniae is mainly epidemic in Denmark with the recurrence every 4-7th year. AIMS: Retrospectively, to describe the epidemiology and clinical features, in infants and children, during the M. pneumoniae epidemic in 2010 and 2011. METHODS: All children under the age of 16 that were tested for M. pneumoniae during the period 01.02.2010-31.01.2012 were included. Medical charts, as well as radiological findings, were reviewed for all children with M. pneumoniae. A post-hoc analysis of viral co-infections was done on part of the cohort. RESULTS: 134 of 746 children were tested positive for M. pneumoniae by PCR or serology. Positive tests were found in 65% of children seven years and older, in 30% of 2-6-year-olds and 4% of infants (less than two years of age). Viral co-infection was found in 27% of the tested samples. The clinical presentation was a cough, asthma-like symptoms and low-grade fever. Extra-pulmonary symptoms were common and presented as nausea/vomiting by 33% of the children and skin manifestations by 25%. 84% of the children had a chest x-ray taken, and there were positive radiological findings in 94% of these. CONCLUSION: M. pneumoniae also affected infants and young children and symptoms were similar to infections with respiratory viruses, but severe LRTI were also seen. During an up-coming epidemic, assessment of extra-pulmonary manifestations can be helpful when diagnosing M. pneumoniae infections.