Predictive Value of Impulse Oscillometry Combined with Fractional Expiratory Nitric Oxide Test for Asthma in Preschool Children.

Objective: Prediction of asthma in preschool children is challenging and lacks objective indicators. The aim is to observe and analyze the variances between impulse oscillometry (IOS) and fractional expiratory nitric oxide (FeNO) in preschool children with wheezing, establish a joint prediction model, and explore the diagnostic value of combining IOS with FeNO in diagnosing asthma among preschool children. Patients and methods: This study enrolled children aged 3-6 years with wheezing between June 2021 and June 2022. They were categorized as asthmatic (n=104) or non-asthmatic (n=109) after a 1-year follow-up. Clinical data, along with IOS and FeNO measurements from both groups, underwent univariate regression and multiple regression analyses to identify predictive factors and develop the most accurate model. The prediction model was built using the stepwise (stepAIC) method. The receiver operating characteristic curve (ROC), calibration curve, Hosmer-Lemeshow test, and decision curve analysis (DCA) were employed to validate and assess the model. Results: During univariate analysis, a history of allergic rhinitis, a history of eczema or atopic dermatitis, and measures including FeNO, R5, X5, R20, Fres, and R5-R20 were found to be associated with asthma diagnosis. Subsequent multivariate analysis revealed elevated FeNO, R5, and X5 as independent risk factors. The stepAIC method selected five factors (history of allergic rhinitis, history of eczema or atopic dermatitis, FeNO, R5, X5) and established a prediction model. The combined model achieved an AUROC of 0.94, with a sensitivity of 0.89 and specificity of 0.88, surpassing that of individual factors. Calibration plots and the HL test confirmed satisfactory accuracy. Conclusion: This study has developed a prediction model based on five factors, potentially aiding clinicians in early identification of asthma risk among preschool children.

Molecular characteristics and biofilm formation capacity of nontypeable Haemophilus influenza strains isolated from lower respiratory tract in children.

With the widespread introduction of the Hib conjugate vaccine, Nontypeable Haemophilus influenzae (NTHi) has emerged as the predominant strain globally. NTHi presents a significant challenge as a causative agent of chronic clinical infections due to its high rates of drug resistance and biofilm formation. While current research on NTHi biofilms in children has primarily focused on upper respiratory diseases, investigations into lower respiratory sources remain limited. In this study, we collected 54 clinical strains of lower respiratory tract origin from children. Molecular information and drug resistance features were obtained through whole gene sequencing and the disk diffusion method, respectively. Additionally, an in vitro biofilm model was established. All clinical strains were identified as NTHi and demonstrated the ability to form biofilms in vitro. Based on scanning electron microscopy and crystal violet staining, the strains were categorized into weak and strong biofilm-forming groups. We explored the correlation between biofilm formation ability and drug resistance patterns, as well as clinical characteristics. Stronger biofilm formation was associated with a longer cough duration and a higher proportion of abnormal lung imaging findings. Frequent intake of ß-lactam antibiotics might be associated with strong biofilm formation. While a complementary relationship between biofilm-forming capacity and drug resistance may exist, further comprehensive studies are warranted. This study confirms the in vitro biofilm formation of clinical NTHi strains and establishes correlations with clinical characteristics, offering valuable insights for combating NTHi infections.

Epidemic Trends and Biofilm Formation Mechanisms of Haemophilus influenzae: Insights into Clinical Implications and Prevention Strategies.

Haemophilus influenzae (H. influenzae) is a significant pathogen responsible for causing respiratory tract infections and invasive diseases, leading to a considerable disease burden. The Haemophilus influenzae type b (Hib) conjugate vaccine has notably decreased the incidence of severe infections caused by Hib strains, and other non-typable H. influenzae (NTHi) serotypes have emerged as epidemic strains worldwide. As a result, the global epidemic trends and antibiotic resistance characteristics of H. influenzae have been altered. Researches on the virulence factors of H. influenzae, particularly the mechanisms underlying biofilm formation, and the development of anti-biofilm strategies hold significant clinical value. This article provides a summary of the epidemic trends, typing methods, virulence factors, biofilm formation mechanisms, and prevention strategies of H. influenzae. The increasing prevalence of NTHi strains and antibiotic resistance among H. influenzae, especially the high ß-lactamase positivity and the emergence of BLNAR strains have increased clinical difficulties. Understanding its virulence factors, especially the formation mechanism of biofilm, and formulating effective anti-biofilm strategies may help to reduce the clinical impact. Therefore, future research efforts should focus on developing new approaches to prevent and control H. influenzae infections.

Acinetobacter baumannii meningitis in children: a case series and literature review.

INTRODUCTION: The incidence of Acinetobacter baumannii meningitis, which typically occurs after neurosurgery, has increased in recent years. Pediatric Acinetobacter baumannii meningitis due to the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains has important clinical significance. METHODOLOGY: We retrospectively reviewed the clinical course and outcome of nine cases of meningitis due to Acinetobacter baumannii in children and reviewed the relevant literature. RESULTS: Seven patients had a history of neurosurgery, and the average time from the first surgery to cerebrospinal fluid (CSF) culture in these seven patients was 23.71 ± 17.43 days. Of all nine patients, four patients showed MDR isolates, two showed XDR isolates, and one showed pan-drug-resistant (PDR) isolates. Three patients received an intrathecal injection of amikacin. Two patients received intravenous colistin (5 mg/kg), and one received polymyxin B (2 mg/kg). The mean hospitalization duration was 39.44 days. Four patients eventually died: two with MDR Acinetobacter, one with PDR Acinetobacter, and one with susceptible Acinetobacter. Two of them still had positive CSF cultures at death. CONCLUSION: Acinetobacter baumannii meningitis is usually associated with neurosurgery and the placement of foreign material, and it usually has a high mortality. Intrathecal or intraventricular polymyxin administration is expected to be an effective choice for meningitis but requires further study.