Objective: To describe the clinical characteristics of Mycoplasma pneumoniae infection and analyze the factors associated with co-infections with other pathogens in children, and provide evidence for improvement of community acquired pneumonia (CAP) prevention and control in children. Methods: Based on the surveillance of hospitalized acute respiratory infections cases conducted in Soochow University Affiliated Children's Hospital (SCH), the CAP cases aged <16 years hospitalized in SCH between 2018 and 2021 were screened. The pathogenic test results of the cases were obtained through the laboratory information system, and their basic information, underlying conditions, and clinical characteristics were collected using a standardized questionnaire. The differences in clinical characteristics between M. pneumoniae infection and bacterial or viral infection and the effect of the co-infection of M. pneumoniae with other pathogens on clinical severity in the cases were analyzed; logistic regression was used to analyze the factors associated with the co-infections with other pathogens. Results: A total of 8 274 hospitalized CAP cases met the inclusion criteria. Among them, 2 184 were positive for M. pneumoniae (26.4%). The M. pneumoniae positivity rate increased with age (P<0.001), and it was higher in girls (P<0.001) and in summer and autumn (P<0.001). There were statistically significant differences in the incidence of wheezing, shortness of breath, wheezing sounds and visible lamellar faint shadow on chest radiographs, as well as fever and hospitalization days among M. pneumoniae, bacterial, and viral infection cases (all P<0.05). In the cases aged <60 months years, co-infection cases had higher rates of wheezing, gurgling with sputum and stridor; and in the cases aged ≥60 months, co-infection cases had a higher rate of shortness of breath (all P<0.05). Multifactorial logistic regression analysis showed that being boys (aOR=1.38,95%CI:1.15-1.67), being aged <6 months (aOR=3.30,95%CI:2.25-4.89), 6-23 months (aOR=3.44,95%CI:2.63-4.51), 24-47 months (aOR=2.50,95%CI:1.90-3.30) and 48-71 months (aOR=1.77,95%CI:1.32-2.37), and history of respiratory infection within 3 months (aOR=1.28,95%CI:1.06-1.55) were factors associated with co-infections of M. pneumoniae with other pathogens. Conclusions: M. pneumoniae was the leading pathogen in children hospitalized due to CAP. M. pneumoniae infections could cause fever for longer days compared with bacterial or viral infections; M. pneumoniae was often co-detected with virus or bacteria. Being boys, being aged <72 months and history of respiratory infection within 3 months were associated factors for co-infections.
Bacteria ; Child ; Coinfection/epidemiology* ; Community-Acquired Infections/epidemiology* ; Dyspnea ; Female ; Humans ; Male ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma/microbiology* ; Respiratory Sounds ; Respiratory Tract Infections/epidemiology* ; Virus Diseases

OBJECTIVETo investigate the association of drug resistance of Mycoplasma pneumoniae (MP) with DNA load and genotypes in children with MP pneumonia.

METHODSA total of 230 children who were hospitalized and diagnosed with MP pneumonia between January 2012 and December 2016 were enrolled. Throat swabs were collected from the 230 children, and a rapid drug sensitivity assay was used to determine the sensitivity of clinical isolates of MP to nine commonly used antibacterial agents. Quantitative real-time PCR was used to measure MP-DNA load in throat swabs. PCR sequencing was used to determine the genotype of 2063 locus of the MP 23S rRNA V domain.

RESULTSOf the 230 children, 86 (37.4%) had genotype A in 2063 locus, 134 (58.3%) had genotype G, 8 (3.5%) had genotype C, and 2 (0.9%) had genotype T. Mutant strains (genotype G+C+T) had a significantly higher MP-DNA load than wild-type strains (genotype A) (P<0.05). The strains resistant to erythromycin, azithromycin, clarithromycin, and clindamycin had a significantly higher MP-DNA load than non-resistant strains (P<0.05). MP had a high drug resistance rate to macrolide antibiotics. More than 60% of the cases with resistance to macrolides were found to have A2063G mutations. MP was rarely resistant to quinolones (less than 2%).

CONCLUSIONSMutations in 2063 locus of the MP 23S rRNA V domain may result in the resistance of MP to macrolides and the change in DNA load and can be used as a basis for selecting drugs for MP.

Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Drug Resistance, Bacterial ; Female ; Genotype ; Humans ; Infant ; Male ; Mycoplasma pneumoniae ; drug effects ; genetics ; Pneumonia, Mycoplasma ; drug therapy ; microbiology

OBJECTIVETo study the role of Mycoplasma pneumoniae (MP) load and antibody measurements in the diagnosis of MP pneumonia.

METHODSA total of 115 children with MP pneumonia and 400 healthy children were enrolled. The MP load and total antibody level were measured at different stages, and the MP load index (MPLI) was calculated.

RESULTSThe cut-off value of MPLI for MP infection was 6.12. MPLI and total antibody titer increased during the course of the disease, while MP-DNA decreased rapidly. Within the same time of blood collection, the group with a higher MP load had a significantly higher total antibody titer than the group with a lower MP load (P<0.05). Within 2 weeks of the course of the disease, the negative antibody group had a significantly higher MPLI than the positive antibody group (P<0.05).

CONCLUSIONSMPLI provides a standardized quantitative value of MP-DNA and plays an important role in the early diagnosis of MP infection.

Antibodies, Bacterial ; blood ; Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Early Diagnosis ; Female ; Humans ; Infant ; Male ; Pneumonia, Mycoplasma ; diagnosis ; microbiology

Humans ; Mycoplasma pneumoniae ; pathogenicity ; Pneumonia, Mycoplasma ; microbiology

Humans ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; microbiology

OBJECTIVETo compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia.

METHODSA total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA.

RESULTSThe positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05).

CONCLUSIONSMP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.

Adolescent ; Bronchoalveolar Lavage Fluid ; microbiology ; Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Female ; Humans ; Infant ; Male ; Nasopharynx ; microbiology ; Pneumonia, Mycoplasma ; diagnosis

No abstract available.
Acute Kidney Injury/microbiology ; Anti-Bacterial Agents/therapeutic use ; Biopsy ; Humans ; Kidney/*microbiology ; Male ; Middle Aged ; Mycoplasma pneumoniae/drug effects/*isolation & purification ; Nephritis/diagnosis/drug therapy/*microbiology ; Pneumonia, Mycoplasma/diagnosis/drug therapy/*microbiology ; Skin Diseases, Bacterial/diagnosis/drug therapy/*microbiology ; Steroids/therapeutic use ; Treatment Outcome ; Vasculitis/diagnosis/drug therapy/*microbiology

OBJECTIVETo analyze the clinical characteristics of Mycoplasma pneumoniae-associated hemophagocytic syndrome (MP-HLH).

METHODA retrospective investigation of the clinical manifestation, laboratory test, imagelogy, clinical course and outcome of 3 cases with MP-HLH seen between June 2013 and July 2013 in Shenzhen Children's Hospital, and review of relevant literature were conducted.

RESULTOf the 3 cases of MP-HLH, 2 were males, one was female, the ages were 1 year, 3 years and 6 years, respectively. They had no underlying disease previously. All the 3 cases had onset of fever, cough as main symptoms. Diagnosis of refractory Mycoplasma pneumoniae pneumonia was made, which was accompanied by decreased neutrophils [(0.08-0.68)×10(9)/L], hemoglobin [(79-103) g/L], platelet [(64-157)×10(9)/L], plasma fibrinogen [(1.3-1.5) g/L], lactate dehydrogenase [(1,170-1,285) U/L] and increased serum ferritin [(936.7-39 789.0) µg/L] in the third week of course. In two cases the T lymphocytes decreased, and the NK cell activity decreased significantly in one. Bone marrow cytology showed prompted bone marrow hyperplasia, and the phenomenon of phagocytosed blood cells. CT scan was performed for all the cases and consolidation with pleural effusion were shown. Two cases were admitted to PICU, and required endotracheal intubation and mechanical ventilation. Flexible bronchoscopy and bronchial lavage were performed and bronchial cast was found in two cases. All of them were treated with macrolide combined with other antibiotics, glucocorticoids and gamma globulin combination therapy, including one case given dexamethasone [10 mg/(m2·d)], cyclosporine[6 mg/(kg·d)], etoposide [150 mg/(m2·d)] chemotherapy. Two cases were cured, and 1 case died. The authors summarized the 18 cases reported in domestic and foreign literature. Foreign children were diagnosed and treated with steroids in 1-2 weeks, and 10 cases were cured, and 2 cases died. They died of massive hemorrhage and meningoencephalitis, and domestic children were diagnosed and treated within two to 4 weeks after onset, 5 cases were cured, one case died of severe pneumonia.

CONCLUSIONMP-HLH is a rare disease in children, and had acute onset, rapid progression and high mortality. Early treatment with steroids was associated with a good prognosis, the key to successful treatment is early diagnosis and treatment, avoiding the immune cascade. Too late a diagnosis or development of serious complications may lead to death.

Anti-Bacterial Agents ; therapeutic use ; Bronchoalveolar Lavage Fluid ; Bronchoscopy ; Child ; Child, Preschool ; Fatal Outcome ; Female ; Fever ; Glucocorticoids ; therapeutic use ; Humans ; Infant ; Lymphohistiocytosis, Hemophagocytic ; diagnosis ; drug therapy ; microbiology ; Macrolides ; therapeutic use ; Male ; Mycoplasma pneumoniae ; isolation & purification ; Pleural Effusion ; Pneumonia, Mycoplasma ; complications ; diagnosis ; drug therapy ; Respiration, Artificial ; Retrospective Studies ; Tomography, X-Ray Computed ; Treatment Outcome

Anti-Bacterial Agents ; administration & dosage ; therapeutic use ; Anti-Inflammatory Agents ; therapeutic use ; Azithromycin ; administration & dosage ; therapeutic use ; Biomarkers ; blood ; Child ; Eyelids ; pathology ; Humans ; Immunoglobulin M ; blood ; Lip ; pathology ; Male ; Methylprednisolone ; administration & dosage ; therapeutic use ; Mucositis ; diagnosis ; drug therapy ; microbiology ; Mycoplasma pneumoniae ; drug effects ; isolation & purification ; Pneumonia, Mycoplasma ; complications ; diagnosis ; drug therapy

OBJECTIVEMycoplasma pneumoniae (MP) is an important pathogen for community-acquired pneumonia in children. MP infection was considered to be self-limited, but many severe refractory MP pneumonia cases have been reported in recent years. The reason for variation in severity of MP pneumonia remains unclear. MP virulence including drug-resistance and host immunologic function are important influencing factors. The present study aimed to clarify relationship between local MP load and severity of MP pneumonia.

METHODMP DNA was quantitatively detected by fluorescent real-time PCR in bronchoalveolar lavage fluid (BALF) from 77 children with MP pneumonia. They were classified into groups of low MP load ( < 10(3)/ml, n = 14) , moderate MP load (10(3)-10(6)/ml, n = 22) and high MP load ( > 10(6)/ml, n = 41) . Clinical symptoms, main laboratory and imaging results of children among the three groups were compared.

RESULTWhen compared with low load group and moderate load group, high load group had longer fever duration (7 d, 10 d vs. 12 d) , longer time to normalization of temperature with macrolide administration (4 d, 8 d vs. 10 d) , more patients with high fever (50.0%, 68.2% vs. 87.8%) and longer duration of fever than 10 d (35.7%, 50.0% vs. 73.2%).Statistically significant difference existed in CRP among the three groups (1.0 mg/L, 11.5 mg/L, 34 mg/L). Large field of consolidation or atelectasis were found in 58.5% of high load patients, much higher than 22.7% in moderate load and 14.3% in low load patients. Bilateral or massive pleural effusion was not found in low load group, while in moderate load and high load group, they were 13.6% and 24.4%. However, no significant difference was found in symptoms and main laboratory and imaging results among different age groups in high load patients.

CONCLUSIONThere is a close relationship between MP load in BALF and clinical characteristics in children with MP pneumonia. Those with high MP load have a more severe process.

Adolescent ; Bacterial Load ; Bronchoalveolar Lavage Fluid ; microbiology ; Child ; Child, Preschool ; Colony Count, Microbial ; DNA, Bacterial ; genetics ; Female ; Humans ; Infant ; Male ; Mycoplasma pneumoniae ; genetics ; isolation & purification ; Pneumonia, Mycoplasma ; microbiology ; pathology ; Real-Time Polymerase Chain Reaction ; Severity of Illness Index