Establishment of a rapid detection method for Mycoplasma pneumoniae based on RPA-CRISPR-Cas12a technology.

Mycoplasma pneumoniae can cause respiratory infections and pneumonia, posing a serious threat to the health of children and adolescents. Early diagnosis of Mycoplasma pneumoniae infection is crucial for clinical treatment. Currently, diagnostic methods for Mycoplasma pneumoniae infection include pathogen detection, molecular biology techniques, and bacterial culture, all of which have certain limitations. Here, we developed a rapid, simple, and accurate detection method for Mycoplasma pneumoniae that does not rely on large equipment or complex operations. This technology combines the CRISPR-Cas12a system with recombinase polymerase amplification (RPA), allowing the detection results to be observed through fluorescence curves and immunochromatographic lateral flow strips.It has been validated that RPA-CRISPR/Cas12a fluorescence analysis and RPA-CRISPR/Cas12-immunochromatographic exhibit no cross-reactivity with other common pathogens, and The established detection limit was ascertained to be as low as 102 copies/µL.Additionally, 49 clinical samples were tested and compared with fluorescence quantitative polymerase chain reaction, demonstrating a sensitivity and specificity of 100%. This platform exhibits promising clinical performance and holds significant potential for clinical application, particularly in settings with limited resources, such as clinical care points or resource-constrained areas.

Clinical profiles of Mycoplasma pneumoniae pneumonia in children with different pleural effusion patterns: a retrospective study.

BACKGROUND: The clinical significance of the presence or absence of Mycoplasma pneumoniae (MP) in pleural effusion in Mycoplasma pneumoniae pneumonia (MPP) children has not yet been elucidated. Herein, we investigated the clinical implication of pleural fluid MP positive in children with MPP. METHODS: A total of 165 MPP children with pleural effusion requiring thoracocentesis were enrolled in this study. They were subsequently divided into two groups according to the presence or absence of MP in pleural effusion, namely positive group (n = 38) and negative group (n = 127). Information on their clinical manifestations, laboratory findings, radiological characteristics and treatment modalities was retrospectively collected from medical chart reviews. RESULTS: The length of hospitalization (15.00 (10.75-19.25) vs. 11.00 (9.00-14.00) days, p=0.001) and total course of illness (23.00 (18.00-28.00) vs. 20.00 (17.00-24.00) days, p=0.010) were significantly longer in the positive group than in the negative group. The occurrence of pericardial effusion (23.7% vs. 7.9%, p=0.017), atelectasis (73.7% vs. 53.5%, p=0.027) and necrotizing pneumonia (23.7% vs. 7.9%, p=0.017) were more frequent in the positive group compared to the negative group. The levels of neutrophil percentages (82.35% (75.40%-85.78%) vs. 72.70% (64.30%-79.90%), p<0.001), C-reactive protein (CRP) (71.12 (37.75-139.41) vs. 31.15 (13.54-65.00) mg/L, p<0.001), procalcitonin (PCT) (0.65 (0.30-3.05) vs. 0.33 (0.17-1.13) ng/ml, p=0.005), serum lactate dehydrogenase (LDH) (799.00 (589.00-1081.50) vs. 673.00 (503.00-869.00) U/L, p=0.009), D-dimer (6.21 (3.37-16.11) vs. 3.32 (2.12-6.62) mg/L, p=0.001) on admission were significantly higher in the positive group than in the negative group. These pronounced differences significantly contributed to the identification of MPP with MP positive pleural effusion, as evidenced by the ROC curve analysis. Marked elevations in adenosine deaminase (49.25 (36.20-60.18) vs. 36.20 (28.10-46.50) U/L, p<0.001) and LDH levels (2298.50 (1259.75-3287.00) vs. 1199.00 (707.00-1761.00) U/L, p<0.001) were observed in pleural fluid of the positive group when compared to the negative group. Meanwhile, the number of patients on low molecular weight heparin (LMWH) therapy (9 (23.7%) vs. 12 (9.4%), p=0.028) was higher in the positive group. Multivariate logistic regression analysis revealed that D-dimer > 7.33 mg/L was significantly associated with the incidence of MP positive pleural effusion in MPP (OR=3.517). CONCLUSIONS: The presence of MP in pleural fluid in MPP children with pleural effusion indicated a more serious clinical course. D-dimer > 7.33 mg/L was a related factor for MP positive pleural effusion in MPP. The results of the present study would help in the creation of a therapeutic plan and prediction of the clinical course of MPP in children.

A Case of Erythrocyte Condensation Caused by Mycoplasma Pneumoniae Infection.

BACKGROUND: Blood routine testing was the most commonly used laboratory method in clinical practice. The results are often influenced by factors such as instruments, reagents, and samples, among which, the interference of cold agglutinin is a very rare element. In our article, we reported a case of red blood cell agglutination caused by Mycoplasma pneumoniae infection. METHODS: The number of blood cells were detected by blood routine analyzer with or without treatment at 37℃ water bath. The red blood cell agglutination was observed through blood smear staining. The cold agglutination test were performed using O-type red blood cells added into patient's plasma and refrigerated overnight at 4℃. We also used luminescent immunoassay technology to detect the content of MP antibodies in patient's serum. RESULTS: The patient's results were RBC (2.69 x 1012/L), MCH (48.5 pg), MCHC (522 g/L). Through a microscope, we observed red blood cell agglutination. The concentration of MP-igM was 60.37 AU/mL. The cold agglutination test was positive. Following a 37℃ water bath, the patient's results changed: RBC (3.85 x 1012/L), MCH (31.2 pg), MCHC (352 g/L). The phenomenon of massive agglutination of red blood cells has also disappeared. CONCLUSIONS: The cold agglutinin produced by MP infection can alter the results of red blood cell. During the epidemic period of MP infection, it is important to pay attention to the phenomenon of abnormal elevation of MCHC in clinical practice.

Diagnostic value of miR-34a in Mycoplasma pneumoniae pneumonia in children and its correlation with rehabilitation effect.

BACKGROUND: Mycoplasma pneumoniae pneumonia (MPP) is responsible for 20 to 40% of all cases of pneumonia acquired by children and shows an increasing incidence year by year. The aim of this study was to investigate the expression of miR-34a in children with MPP and its diagnostic value, and further explore the relationship between miR-34a and the rehabilitation effect of children with MPP. METHODS: The expression level of miR-34a was detected by RT-qPCR, and the clinical value of miR-34a was analyzed by ROC analysis. In addition, the levels of IL-6, IL-18 and TNF-α in serum of children with MPP were detected by ELISA kit, and the correlation with miR-34a was analyzed. RESULTS: Elevated levels of miR-34a were observed in the serum of children with MPP, and significantly higher expression levels were observed in children with severe symptoms and poor rehabilitation. The study suggested that miR-34a has potential as a diagnostic marker for MPP in children, helping to distinguish between mild and severe cases and predicting rehabilitation from MPP in children. In addition, miR-34a expression was positively correlated with IL-6, IL-8, and TNF-α levels. CONCLUSIONS: miR-34a is closely related to MPP in children and miR-34a may be used as a clinical biomarker for MPP in children.

Routine blood parameters as auxiliary diagnostic tools for Mycoplasma pneumoniae infection in children.

Introduction. Recently, the incidence of Mycoplasma pneumoniae (M. pneumoniae) infection in children has been increasing annually. Early differential diagnosis of M. pneumoniae infection can not only avoid the abuse of antibiotics, but also is essential for early treatment and reduction of transmission.Gap statement. The change of routine blood parameters may have important clinical significance for the diagnosis of M. pneumoniae infection, but it has not been reported so far.Aim. This study aims to establish a predictive model for M. pneumoniae infection and explore the changes and clinical value of routine blood parameters in children with M. pneumoniae infection, serving as auxiliary indicators for the diagnosis and differentiation of clinical M. pneumoniae infection.Methodology. A total of 770 paediatric patients with respiratory tract infections were enrolled in this study, including 360 in the M. pneumoniae group, 40 in the SARS-CoV-2 group, 200 in the influenza A virus group, and 170 in the control group. The differences of routine blood parameters among all groups were compared, and risk factors were analysed using multivariate logistics analysis, and the diagnostic efficacy of differential indicators using ROC curves.Results. This study revealed that Mono% (OR: 3.411; 95% CI: 1.638-7.102; P=0.001) was independent risk factor associated with M. pneumoniae infection, and Mono% (AUC=0.786, the optimal cutoff at 7.8%) had a good discriminative ability between patients with M. pneumoniae infection and healthy individuals. Additionally, Mono% (OR: 0.424; 95% CI: 0.231-0.781; P=0.006) and Lymp% (OR: 0.430; 95% CI: 0.246-0.753; P=0.003) were independent risk factors for distinguishing M. pneumoniae infection from influenza A virus infection, and the Lymp% (AUC=0.786, the optimal cutoff at 22.1%) and Net% (AUC=0.761, the optimal cutoff at 65.2%) had good discriminative abilities between M. pneumoniae infection and influenza A infection. Furthermore, platelet distribution width (OR: 0.680; 95% CI: 0.538-0.858; P=0.001) was independent risk factor for distinguishing M. pneumoniae infection from SARS-CoV-2 infection. Meanwhile, the ROC curve demonstrated that PDW (AUC=0.786, the optimal cutoff at 15%) has a good ability to differentiate between M. pneumoniae infection and SARS-CoV-2 infection.Conclusion. This study demonstrates that routine blood parameters can be used as auxiliary diagnostic indicators for M. pneumoniae infection and provide reference for the diagnosis and differentiation of clinical M. pneumoniae infection.

Epidemiological characteristics of mycoplasma pneumoniae in hospitalized children before, during, and after COVID-19 pandemic restrictions in Chongqing, China.

Background: Mycoplasma pneumoniae (MP) is a significant cause of community-acquired pneumonia with high macrolide resistance rates. Various COVID-19 pandemic restrictions have impacted the prevalence of MP. Objective: To assess the changes in the pattern of MP infections among children before, during, and after the COVID-19 pandemic. Methods: A total of 36685 enrolled patients, aged 0-18 years, diagnosed with pneumonia and admitted to Children's Hospital of Chongqing Medical University from January 2019 to December 2023, were retrospectively reviewed in this study. The epidemiological characteristics of pediatric MP infection were analyzed. Results: Among 36685 patients, 7610 (20.74%) tested positive for MP. The highest positive rate was observed among children aged over 6 years (55.06%). There was no gender disparity in MP infection across the three phases of the COVID-19 pandemic. Hospital stays were longest for children during the COVID-19 pandemic (P <0.001). MP infection was most prevalent in the summer (29.64%). The lowest positive rate was observed during the pandemic, with the highest rate found after easing the measures across all age groups (P <0.001). There was a surge in the positive rate of MP in the third year after the COVID-19 pandemic. Regression analyses demonstrated a shift in the age range susceptible to MP infection, with children aged 3.8 to 13.5 years post-pandemic compared to the pre-pandemic range of 5.3 to 15.5 years old. Additionally, the average macrolide resistance rate was 79.84%. We observed a higher resistance rate during the pandemic than in the pre- and post-pandemic phases (P <0.001). Conclusion: The restrictive measures implemented during the COVID-19 pandemic have influenced the spread of MP to some extent and altered demographic and clinical characteristics, such as age, age group, season, length of stay, and macrolide resistance. We recommend continuous surveillance of the evolving epidemiological characteristics of MP infection in the post-pandemic period when restrictions are no longer necessary.

Persistent elevation in incidence of pneumonia in children in England, 2023/24.

Since November 2023, the absolute number of attendances at emergency departments for pneumonia among children aged 5-14 years in England have been above expected levels for the time of year. This increased signal peaked during March 2024 but then persisted into early summer 2024 despite decreases in prevalence of seasonal respiratory pathogens. Record linkage between emergency department and laboratory databases points to this unusual activity being driven largely by Mycoplasma pneumoniae.

Distinct clinical characteristics of bocavirus and Mycoplasma pneumoniae infection in children plastic bronchitis.

BACKGROUND: This study investigated clinical and laboratory characteristics of human bocavirus type 1 (HBoV1)-plastic bronchiolitis (PB), Mycoplasma pneumoniae (MP)-associated plastic bronchitis (PB) and MP-NPB in children, highlighting inflammation, coagulation, and bronchoscopic needs. METHODS: Data on preschool children with PB during HBoV1 or MP infection were collected, comparing MP-PB to severe Mycoplasma pneumoniae pneumonia. RESULT: Compared with the MP-PB group, the HBoV1-PB group, with younger children, had significantly milder clinical symptoms but higher WBC counts (p = .028). The MP-PB group exhibited notably elevated Fibrinogen (p = .045) and d-dimer levels (p < .001). When contrasting the MP-PB with the MP-NPB group, children in MP-PB group still had higher levels of d-dimer and increased inflammatory indicators such as C-reactive protein, procalcitonin, lactate dehydrogenase, and interleukin-6, which were significantly elevated compared with the MP-NPB group. MP-PB showed a higher prevalence of plastic bronchial casts in lower lobes (p = .016) and a dominance of neutrophils in BALF cytology. Additionally, children in the MP-PB group tended to undergo a greater number of bronchoscopies. CONCLUSION: This study identifies key differences in plastic bronchitis in children due to HBoV1 and MP, highlighting HBoV1's milder inflammation in younger kids and MP's link to severe inflammatory and coagulation responses, guiding clinical diagnosis and treatment.

Predictive signature of murine and human host response to typical and atypical pneumonia.

BACKGROUND: Pneumonia due to typical bacterial, atypical bacterial and viral pathogens can be difficult to clinically differentiate. Host response-based diagnostics are emerging as a complementary diagnostic strategy to pathogen detection. METHODS: We used murine models of typical bacterial, atypical bacterial and viral pneumonia to develop diagnostic signatures and understand the host's response to these types of infections. Mice were intranasally inoculated with Streptococcus pneumoniae, Mycoplasma pneumoniae, influenza or saline as a control. Peripheral blood gene expression analysis was performed at multiple time points. Differentially expressed genes were used to perform gene set enrichment analysis and generate diagnostic signatures. These murine-derived signatures were externally validated in silico using human gene expression data. The response to S. pneumoniae was the most rapid and robust. RESULTS: Mice infected with M. pneumoniae had a delayed response more similar to influenza-infected animals. Diagnostic signatures for the three types of infection had 0.94-1.00 area under the receiver operator curve (auROC). Validation in five human gene expression datasets revealed auROC of 0.82-0.96. DISCUSSION: This study identified discrete host responses to typical bacterial, atypical bacterial and viral aetiologies of pneumonia in mice. These signatures validated well in humans, highlighting the conserved nature of the host response to these pathogen classes.

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.

Mycoplasma pneumoniae-induced Kawasaki disease via PINK1/Parkin-mediated mitophagy.

Kawasaki disease (KD) is a systemic vasculitis with an unknown cause that primarily affects children. The objective of this study was to explore the function and underlying mechanism of mitophagy in Mycoplasma pneumoniae (MP)-induced KD. To create MP-induced KD models, Human coronary endothelial cells (HCAECs) and DBA/2 mice were employed and treated with Mp-Lipid-associated membrane proteins （LAMPs）. Lactate dehydrogenase (LDH) levels were tested to determine cellular damage or death. The inflammatory cytokines tumor necrosis factor (TNF)--α and interleukin (IL)-6 were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) method. RT-qPCR and Western blotting were used to determine the expression of Intercellular Adhesion Molecule(ICAM)-1, vascular cell adhesion molecule (VCAM)-1, inducible nitric oxide synthase(iNOS), LC3, p62, PINK1(a mitochondrial serine/threonine-protein kinase), and PARKIN(a cytosolic E3-ubiquitin ligase). The adenosine triphosphate （ATP）, reactive oxygen species （ROS）, and mitochondrial membrane potential（MMP） levels were measured to determine mitochondrial function. Mitophagy was investigated using immunofluorescence and a mitophagy detection test. Autophagosome and mitochondrial morphology were examined using transmission electron microscopy. To identify inflammatory cell infiltration, hematoxylin and eosin staining was utilized. Mp-LAMPs increased the levels of TNF-α, IL-6, ICAM-1, VCAM-1, and iNOS in an HCAEC cell model, along with LDH release. After Mp-LAMPs exposure, there was a rise in LC3 and a reduction in p62. Meanwhile, the expression of PINK1 and Parkin was increased. Cyclosporin A dramatically increased ATP synthesis and MMP in HCAEC cells treated with Mp-LAMPs, while suppressing ROS generation, demonstrating excessive mitophagy-related mitochondrial dysfunction. Additionally, neither body weight nor artery tissue were affected due to PINK1 and Parkin suppression Cyclosporin A in Mp-LAMPs-treated mice. These findings indicated that PINK1/Parkin-mediated mitophagy inhibition may be a therapeutic target for MP-induced KD.

Mycoplasma pneumoniae infection outbreak in Guangzhou, China after COVID-19 pandemic.

BACKGROUNDS: Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen causing respiratory diseases in children. This study aimed to characterize epidemiological and disease severity shifts of M. pneumoniae: infections in Guangzhou, China during and after the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Throat swab samples were obtained from 5405 hospitalized patients with symptoms of acute respiratory infections to detect M. pneumoniae. Differences in epidemiological and clinical characteristics of M. pneumoniae: infections were investigated during 2020-2022 and after COVID-19 pandemic (2023). RESULTS: M. pneumoniae were detected in 849 (15.6%, 849/5405) patients. The highest annual positive rate was 29.4% (754/2570) in 2023, followed by 5.3% (72/1367) in 2022, 1.2% (12/1015) in 2021, and 2.0% (11/553) in 2020, with significantly increasing annual prevalence from 2020 to 2023. M. pneumoniae incidence peaked between July and December post-COVID-19 pandemic in 2023, with the highest monthly positive rate (56.4%, 165/293). Clinical characteristics and outcomes of patients with M. pneumoniae did not vary between periods during and after COVID-19 pandemic except that patients with M. pneumoniae post-COVID-19 pandemic were more likely to develop fever. Patients with severe M. pneumoniae pneumonia (SMPP) were more likely to develop respiratory complications, myocardial damage, and gastrointestinal dysfunction than those with non-SMPP. Patients with SMPP had lower lymphocytes, CD3+ T cells, CD4+ T cells, CD8+ T cells, B cells, and higher IL-4, IL-6, IL-10 levels than those with non-SMPP. Bronchoalveolar lavage fluid specimens from infected patients were obtained to identify macrolide resistance mutations. Macrolide-resistant M. pneumoniae (MRMP) proportion in 2023 was 91.1% (215/236). CONCLUSION: Outbreaks of M. pneumoniae: occurred in Guangzhou, China in 2023 upon Non-pharmaceutical interventions easing. Despite the increasing incidence of M. pneumoniae, the disease severity remained similar during and after the COVID-19 pandemic.

Comparative genomic analysis identifies potential adaptive variation in Mycoplasma ovipneumoniae.

Mycoplasma ovipneumoniae is associated with respiratory disease in wild and domestic Caprinae globally, with wide variation in disease outcomes within and between host species. To gain insight into phylogenetic structure and mechanisms of pathogenicity for this bacterial species, we compared M. ovipneumoniae genomes for 99 samples from 6 countries (Australia, Bosnia and Herzegovina, Brazil, China, France and USA) and 4 host species (domestic sheep, domestic goats, bighorn sheep and caribou). Core genome sequences of M. ovipneumoniae assemblies from domestic sheep and goats fell into two well-supported phylogenetic clades that are divergent enough to be considered different bacterial species, consistent with each of these two clades having an evolutionary origin in separate host species. Genome assemblies from bighorn sheep and caribou also fell within these two clades, indicating multiple spillover events, most commonly from domestic sheep. Pangenome analysis indicated a high percentage (91.4 %) of accessory genes (i.e. genes found only in a subset of assemblies) compared to core genes (i.e. genes found in all assemblies), potentially indicating a propensity for this pathogen to adapt to within-host conditions. In addition, many genes related to carbon metabolism, which is a virulence factor for Mycoplasmas, showed evidence for homologous recombination, a potential signature of adaptation. The presence or absence of annotated genes was very similar between sheep and goat clades, with only two annotated genes significantly clade-associated. However, three M. ovipneumoniae genome assemblies from asymptomatic caribou in Alaska formed a highly divergent subclade within the sheep clade that lacked 23 annotated genes compared to other assemblies, and many of these genes had functions related to carbon metabolism. Overall, our results suggest that adaptation of M. ovipneumoniae has involved evolution of carbon metabolism pathways and virulence mechanisms related to those pathways. The genes involved in these pathways, along with other genes identified as potentially involved in virulence in this study, are potential targets for future investigation into a possible genomic basis for the high variation observed in disease outcomes within and between wild and domestic host species.

Epidemiological characteristics and early predict model of children Mycoplasma Pneumoniae Pneumonia outbreaks after the COVID-19 in Shandong.

Since October 2023, a significant outbreak of Mycoplasma Pneumoniae Pneumonia (MPP) has been observed in children in northern China. Chinese health authorities have attributed this epidemiological to immune debt resulting from the relaxation of coronavirus disease 2019 (COVID-19) control measures. This study described the epidemiological features of Mycoplasma pneumoniae (MP) prevalence in children and developed a straightforward prediction model to differentiate between MPP and viral pneumonia in children. The infection rate of MP in children notably increased from 8.12 in 2022 to 14.94% in 2023, peaking between October and November, especially among school-age children. Logistic regression screening identified four key indicators: Age, D-Dimer levels, erythrocyte sedimentation rate, and gender. The developed nomogram exhibited a receiver operator characteristic curve-area under the curve (ROC-AUC) of 0.858, with external validation confirming an ROC-AUC of 0.794. This study examined the epidemiological characteristics of MPP prevalence in children in Shandong Province during and after the COVID-19 pandemic. An early predict model was developed and validated to differentiate between Mycoplasma Pneumoniae and viral infections.

Effects of inflammatory stimuli on the development of Mycoplasma bovis pneumonia in experimentally challenged calves.

Many cattle infected with Mycoplasma bovis remain healthy while others develop severe chronic respiratory disease. We hypothesized that inflammatory stimuli such as co-pathogens worsen disease outcomes in M. bovis-infected calves. Calves (n=24) were intrabronchially inoculated with M. bovis and either killed bacterial lysate, transient M. haemolytica infection, or saline. Caseonecrotic lesions developed in 7/7 animals given M. haemolytica and M. bovis compared to 2/8 given M. bovis with no inflammatory stimulus, and 6/9 animals given bacterial lysate and M. bovis (P=0.01). Animals receiving M. haemolytica and M. bovis had more caseonecrotic foci in lungs than those receiving M. bovis with no inflammatory stimulus (median = 21 vs 0; P = 0.01), with an intermediate response (median = 5) in animals given bacterial lysate. In addition to caseonecrotic foci, infected animals developed neutrophilic bronchiolitis that appeared to develop into caseonecrotic foci, peribronchiolar lymphocytic cuffs that were not associated with the other lesions, and 4 animals with bronchiolitis obliterans. The data showed that transient lung inflammation at the time of M. bovis infection provoked the development of caseonecrotic bronchopneumonia, and the severity of inflammation influenced the number of caseonecrotic foci that developed. In contrast, caseonecrotic lesions were few or absent in M. bovis-infected calves without a concurrent inflammatory stimulus. These studies provide insight into how caseonecrotic lesions develop within the lung of M. bovis-infected calves. This and other studies suggest that controlling co-pathogens and harmful inflammatory responses in animals infected with M. bovis could potentially minimize development of M. bovis caseonecrotic bronchopneumonia.

Analysis of the epidemic characteristics of common respiratory pathogens infection in children in a 3A special hospital.

OBJECTIVE: To analyze the epidemic characteristics of common respiratory tract infection pathogens in children with respiratory tract infection, and provide scientific basis for the prevention and control of respiratory tract infection. METHODS: A retrospective collection of clinical data was conducted on 11,538 children with respiratory tract infections at Luoyang Maternal and Child Health Hospital from December 2022 to November 2023. The types of respiratory tract infections, including upper and lower respiratory tract infections, as well as five respiratory pathogens: influenza A virus (influenza A), influenza B virus (influenza B virus, adenovirus (ADV), respiratory syncytial virus (RSV), and Mycoplasma pneumoniae (MP) infections, were analyzed and compared for different genders, ages, temperatures, and air quality in different months; And the changes of five pathogens in children with respiratory tract infections of different disease severity. RESULTS: From December 2022 to November 2023, a total of 11,538 children with respiratory infections were included in the analysis, including 6436 males and 5102 females, with an age of 4.92 ± 2.03 years. The proportion of upper respiratory tract infections is as high as 72.17%, and lower respiratory tract infections account for 27.83%. Among them, 2387 were positive for Flu A antigen, with a positive rate of 20.69%, 51 cases were positive for Flu B antigen, and the positive rate was 0.4%, 1296 cases were positive for adv antigen, with a positive rate of 11.23%, 868 cases were positive for RSV antigen, with a positive rate of 7.52%, 2481 cases were positive for MP IgM antibody or MP antigen, and the positive rate was 21.50%. Flu B in male children The infection rate of ADV and MP was higher than that of female children (p < 0.05); Among children in different age groups, the older the age, the older the Flu A The higher the infection rate of MP (p < 0.05), the higher the positive rate of RSV in children with younger age (p < 0.05). The positive rate of ADV in children aged 3-6 years and > 6 years was higher than that in children aged 0-3 years (p < 0.05); Flu A and MP are popular throughout the year, and the positive rate peaks during the period of temperature rise and air quality decline from February to March, and during the period of temperature drop and air quality index rise from August to November, The positive rate of RSV peaked after the turning point of temperature rise from March to April. The infection rate was higher during the period of sharp decline in air quality from March to May and sharp decline in temperature in November, The positive rate of ADV was higher at the turning point of temperature rise from February to March, and then the infection rate decreased. During the period of sharp temperature drop from August to November, the positive rate increased sharply, and the peak of infection occurred; As the disease worsens, The positive rates of Flu A, Flu B, RSV, MP and combined infection with more than two pathogens were all increased (p < 0.05). CONCLUSION: After the new coronavirus epidemic in 2022, Flu A and MP have the highest infection rate of respiratory pathogens in children, showing a peak growth in general, with epidemic characteristics changing with environmental temperature, air quality and seasons. The main disease type is upper respiratory tract infection, MP and adv infections were mainly in male children, Flu A, MP and ADV infections are more common in older children, RSV infection was more common in younger children; Flu A, Flu B, RSV and MP infection and the co infection of more than two pathogens may more easily lead to the occurrence of severe pneumonia.

[Clinical characteristics and predictive factors for plastic bronchitis in children with severe Mycoplasma pneumoniae pneumonia].

Objective: To explore the clinical characteristics and predictive factors for plastic bronchitis (PB) in children with severe Mycoplasma pneumoniae pneumonia (SMPP). Methods: A retrospective cohort enrolled children with a clinical diagnosis of SMPP who were treated at the Department of Respiratory Medicine of Tianjin Children's Hospital Machang District from January 1, 2018, to October 31, 2023. According to the bronchoscopy and pathological examination results, the patients were divided into 142 cases in the PB group and 274 cases in the non-PB group. The clinical manifestations, laboratory data, imaging findings, and treatments were analyzed.Mann-Whitney U test and Chi-square test were used to analyze the differences between the two groups, and multivariate Logistic regression was used to analyze the risk factors. The receiver operating characteristic (ROC) curve was used to explore the predictive value of PB in SMPP. Results: Among 416 SMPP children, there were 197 males and 219 females; PB group 142 cases, non-PB group 274 cases, the age of disease onset was (6.9±2.9) years and (6.6±2.8) years in the PB group and the non-PB group respectively. The incidence of wheezing symptoms, hypoxemia, heat peak >40 ℃, the duration of fever, neutrophil-lymphocyte ratio, mean platelet volume, C-reactive protein, procalcitonin, interleukin-6, alanine transaminase, aspartate aminotransferase and ferritin were higher in the PB group (16 cases (11.3%) vs. 15 cases (5.5%), 14 cases (9.9%) vs. 12 cases (4.4%), 57 cases (40.1%) vs. 67 cases (24.5%), 10 (8, 12) vs. 9 (8, 12) d, 6.1 (4.1, 13.1)×109 vs. 5.0 (3.7, 6.8)×109/L, 10.2 (9.6, 10.8) vs. 9.4 (8.9, 10.1) fl, 33.4 (16.0, 67.5) vs. 23.0 (10.4, 56.1) mg/L, 0.24 (0.12, 0.48) vs. 0.16 (0.09, 0.31) µg/L, 39.9 (25.1, 81.4) vs. 31.3 (18.3, 59.3) ng/L, 16.0 (12.0, 29.0) vs. 14.0 (10.0, 24.3) U/L, 38.5 (28.0, 52.5) vs. 33.0 (25.0, 44.0) U/L, 233 (136, 488) vs. 156 (110, 293) µg/L, χ2=4.55, 4.79, 11.00, Z=2.25, 4.00, 6.64, 2.76, 2.98, 3.09, 2.22, 2.62, 4.18, all P<0.05). Multivariate Logistic regression analysis showed that the dyspnea (OR=2.97, 95%CI 1.35-6.55, P=0.007), the diminution of respiration (OR=2.40, 95%CI 1.27-4.52, P=0.006), neutrophil-lymphocyte ratio (NLR) (OR=2.07, 95%CI 1.71-2.51, P<0.001), lactate dehydrogenase (LDH) (OR=1.01, 95%CI 1.00-1.01, P<0.001), mean platelet volume/platelet count (MPV/PLT) (OR=1.39, 95%CI 1.13-1.71, P=0.002), pleural effusion (OR=2.23, 95%CI 1.21-4.13, P=0.011),≥2/3 lobe consolidation (OR=1.84, 95%CI 1.04-3.00, P=0.039) and atelectasis (OR=1.98, 95%CI 1.02-3.48, P=0.044) were independent predictors of PB in children with SMPP. ROC curve analysis showed that the cut-off values for NLR, LDH and MPV/PLT in the diagnosis of PB were 2.79 (sensitivity 0.89, specificity 0.69, area under the curve (AUC)=0.86, P<0.001), 474 U/L (sensitivity 0.63, specificity 0.65, AUC=0.70, P=0.003) and 0.04 (sensitivity 0.75, specificity 0.53, AUC=0.68, P=0.005) respectively. Children in the PB group had longer hospital stays and corticosteroid treatment course than those in the non-PB group, the proportion of children in the PB group who received bronchoscopy treatment twice or more was higher (9 (8, 12) vs. 8 (6, 10) d, 7 (5, 8) vs. 6 (5, 7) d, 128 cases (90.1%) vs. 218 cases (79.6%), 106 cases (74.7%) vs. 54 cases (19.7%), Z=6.70, 5.06, χ2=7.48, 119.27, all P<0.05). Conclusions: The dyspnea, respiration diminution, NLR level elevation (>2.79) and pleural effusion were predictive factors for PB in children with SMPP. This provides a basis for the early identification of PB in children with SMPP.

Changes in urinary renal injury markers in children with Mycoplasma pneumoniae pneumonia and a prediction model for related early renal injury.

BACKGROUND: This study aims to analyse changes in urinary kidney injury markers in children with Mycoplasma pneumoniae pneumonia (MPP), investigate the risk factors for MPP-related acute kidney injury (AKI) and establish a model to predict MPP-related AKI. METHODS: Ninety-five children were enrolled based on the study's inclusion and exclusion criteria. They were divided into a severe MPP (SMPP) group and a non-SMPP group and then into an AKI group and a non-AKI group according to the presence of AKI. A univariate logistic regression analysis was performed to explore the early risk factors for AKI. Based on a multivariate logistic regression analysis and a least absolute shrinkage and selection operator regression analysis, appropriate variables were selected to establish a prediction model, and R 4.2.2 software was used to draw nomograms and generate a dynamic nomogram website. RESULTS: Seven urinary kidney injury markers were abnormally elevated in the SMPP group and the non-SMPP group: urinary N-acetyl-ß-D-glucosaminidase (NAG), ß2-microglobulin, α1-microglobulin, retinol-binding protein, urinary immunoglobulin G, urinary transferrin and urinary microalbumin. Sixteen children were identified with AKI during hospitalisation. The AKI group had higher levels of urinary NAG, α1-microglobulin, ß2-microglobulin, urinary microalbumin, urinary transferrin and retinol-binding protein than the non-AKI group (P < 0.05). The MPP-related AKI prediction model consists of four indicators (serum immunoglobulin M [IgM], C-reactive protein [CRP], urine NAG and sputum plug presence) and a dynamic nomogram. CONCLUSION: Urinary kidney injury markers are often elevated in children with MPP; urinary NAG is the marker most likely to be elevated, and it is especially evident in severe cases. The nomogram of the prediction model, comprising serum IgM, CRP, urinary NAG and sputum plug presence, can predict the probability of AKI in children with MPP.

An accurate and convenient method for Mycoplasma pneumoniae via one-step LAMP-CRISPR/Cas12b detection platform.

Introduction: Mycoplasma pneumoniae (MP) is the major cause of respiratory infections that threaten the health of children and adolescents worldwide. Therefore, an early, simple, and accurate detection approach for MP is critical to prevent outbreaks of MP-induced community-acquired pneumonia. Methods: Here, we explored a simple and accurate method for MP identification that combines loop-mediated isothermal amplification (LAMP) with the CRISPR/Cas12b assay in a one-pot reaction. Results: In the current study, the whole reaction was completed within 1 h at a constant temperature of 57°C. The limit of detection of this assay was 33.7 copies per reaction. The specificity of the LAMP-CRISPR/Cas12b method was 100%, without any cross-reactivity with other pathogens. Overall, 272 clinical samples were used to evaluate the clinical performance of LAMP-CRISPR/Cas12b. Compared with the gold standard results from real-time PCR, the present method provided a sensitivity of 88.11% (126/143), specificity of 100% (129/129), and consistency of 93.75% (255/272). Discussion: Taken together, our preliminary results illustrate that the LAMP-CRISPR/Cas12b method is a simple and reliable tool for MP diagnosis that can be performed in resource-limited regions.

Real-time fluorescent multiple cross displacement amplification for rapid and sensitive Mycoplasma pneumoniae detection.

Mycoplasma pneumoniae is a significant pathogen responsible for community-acquired pneumonia, predominantly affecting children and adolescents. Here, we devised a rapid method for M. pneumoniae that combined multiple cross displacement amplification (MCDA) with real-time fluorescence technology. A set of ten primers, which were specifically designed for M. pneumoniae detection, were employed in a real-time fluorescence MCDA reaction. Of these, one primer incorporated a restriction endonuclease recognition sequence, a fluorophore, and a quencher, facilitating real-time fluorescence detection. The real-time (RT)-MCDA reactions were monitored in a simple real-time fluorescence instrument and conducted under optimised conditions (64°C for 40 min). The detection limit of the M. pneumoniae RT-MCDA assay for genomic DNA extracted from M. pneumoniae culture was down to 43 fg/µl. This assay accurately identified M. pneumoniae strains without cross-reacting with other bacteria. To validate its practical application, we tested the M. pneumoniae RT-MCDA assay using genomic DNA extracted from clinical samples. The assay's detection capability proved comparable with real-time PCR, MCDA-based biosensor detection, and visual inspection under blue light. The entire process, including rapid DNA extraction and real-time MCDA detection, was completed within 1 h. Overall, the M. pneumoniae RT-MCDA assay reported here is a simple and effective diagnostic tool for rapid M. pneumoniae detection, which holds significant potential for point-of-care testing and in resource-limited regions.