The clinical significance of macrolide resistance in pediatric Mycoplasma pneumoniae infection during COVID-19 pandemic.

Background: Mycoplasma pneumoniae (MP) is a commonly occurring pathogen causing community-acquired pneumonia (CAP) in children. The global prevalence of macrolide-resistant MP (MRMP) infection, especially in Asian regions, is increasing rapidly. However, the prevalence of MRMP and its clinical significance during the COVID-19 pandemic is not clear. Methods: This study enrolled children with molecularly confirmed macrolide-susceptible MP (MSMP) and MRMP CAP from Beijing Children's Hospital Baoding Hospital, Capital Medical University between August 2021 and July 2022. The clinical characteristics, laboratory findings, chest imaging presentations, and strain genotypes were compared between patients with MSMP and MRMP CAP. Results: A total of 520 hospitalized children with MP-CAP were enrolled in the study, with a macrolide resistance rate of 92.7%. Patients with MRMP infection exhibited more severe clinical manifestations (such as dyspnea and pleural effusion) and had a longer hospital stay than the MSMP group. Furthermore, abnormal blood test results (including increased LDH and D-dimer) were more common in the MRMP group (P<0.05). Multilocus variable-number tandem-repeat analysis (MLVA) was performed on 304 samples based on four loci (Mpn13-16), and M3562 and M4572 were the major types, accounting for 74.0% and 16.8% of the strains, respectively. The macrolide resistance rate of M3562 strains was up to 95.1%. Conclusion: The prevalence of MRMP strains in hospitalized CAP patients was extremely high in the Baoding area, and patients infected with MRMP strains exhibited more severe clinical features and increased LDH and D-dimer. M3562 was the predominant resistant clone.

DNA-scaffolded multivalent vaccine against SARS-CoV-2.

Short peptides are poor immunogens. One way to increase their immune responses is by arraying immunogens in multivalency. Simple and efficient scaffolds for spatial controlling the inter-antigen distance and enhancing immune activation are required. Here, we report a molecular vaccine design principle that maximally drives potent SARS-CoV-2 RBD subunit vaccine on DNA duplex to induce robust and efficacious immune responses in vivo. We expect that the DNA-peptide epitope platform represents a facile and generalizable strategy to enhance the immune response. STATEMENT OF SIGNIFICANCE: DNA scaffolds offer a biocompatible and convenient platform for arraying immunogens in multivalency antigenic peptides, and spatially control the inter-antigen distance. This can effectively enhance immune response. Peptide (instead of entire protein) vaccines are highly attractive. However, short peptides are poor immunogens. Our DNA scaffolded multivalent peptide immunogen system induced robust and efficacious immune response in vivo as demonstrated by the antigenic peptide against SARS-CoV-2. The present strategy could be readily generalized and adapted to prepare multivalent vaccines against other viruses or disease. Particularly, the different antigens could be integrated into one single vaccine and lead to super-vaccines that can protect the host from multiple different viruses or multiple variants of the same virus.

A bat MERS-like coronavirus circulates in pangolins and utilizes human DPP4 and host proteases for cell entry.

It is unknown whether pangolins, the most trafficked mammals, play a role in the zoonotic transmission of bat coronaviruses. We report the circulation of a novel MERS-like coronavirus in Malayan pangolins, named Manis javanica HKU4-related coronavirus (MjHKU4r-CoV). Among 86 animals, four tested positive by pan-CoV PCR, and seven tested seropositive (11 and 12.8%). Four nearly identical (99.9%) genome sequences were obtained, and one virus was isolated (MjHKU4r-CoV-1). This virus utilizes human dipeptidyl peptidase-4 (hDPP4) as a receptor and host proteases for cell infection, which is enhanced by a furin cleavage site that is absent in all known bat HKU4r-CoVs. The MjHKU4r-CoV-1 spike shows higher binding affinity for hDPP4, and MjHKU4r-CoV-1 has a wider host range than bat HKU4-CoV. MjHKU4r-CoV-1 is infectious and pathogenic in human airways and intestinal organs and in hDPP4-transgenic mice. Our study highlights the importance of pangolins as reservoir hosts of coronaviruses poised for human disease emergence.

Maternal and neonatal safety of COVID-19 vaccination during the peri-pregnancy period: A prospective study.

BACKGROUND: To investigate the safety of inactivated COVID-19 vaccine in Chinese pregnant women and their fetuses when inoculated during the peri-pregnancy period. METHODS: Eligible pregnant women were prospectively collected and divided into a vaccine group (n = 93) and control group (n = 160) according to whether they had been vaccinated against COVID-19 within 3 months before their last menstruation period (LMP) and after pregnancy. Demographic data of couples, complications during pregnancy and delivery of pregnant women, and data of newborns at birth were collected. RESULTS: Sixty-six women were vaccinated with a median time of 35.5 (range = 0-91) days before LMP, and 27 women were vaccinated with a median time of 17 (range = 1-72) days after LMP. The incidence of premature rupture of membrane (PROM) in the vaccine group was significantly higher than that in the control group (16.13% vs. 6.88%, p = 0.019). Multivariate logistic regression analysis revealed that maternal peri-pregnancy COVID-19 vaccination was not an independent risk factor for PROM (odds ratio: 2.407, 95% confidence interval: 0.932-6.216, p = 0.069). There was no difference in the incidence of other complications during pregnancy and delivery between the two groups. A total of 253 neonates were delivered, including two cases with congenital abnormalities in each group. The incidence of congenital abnormalities between the two groups was similar (2.15% vs. 1.25%, p = 0.626). There was no difference in neonatal length, weight, head circumference, and Apgar score between the two groups (p > 0.05), but the incidence of neonatal jaundice in the vaccine group was significantly higher than that in the control group (20.43% vs. 7.5%, p = 0.002). Multivariate logistic regression analysis revealed that maternal peri-pregnancy vaccination, postpartum blood loss, cesarean section, 1-min Apgar score, and paternal smoking were independent risk factors for neonatal jaundice. CONCLUSIONS: It is safe for pregnant women and their fetuses to be inoculated the inactivated COVID-19 vaccine during the peri-pregnancy period, but attention should be paid to neonatal jaundice.

The Glycan-Binding Trait of the Sarbecovirus Spike N-Terminal Domain Reveals an Evolutionary Footprint.

The spike protein on sarbecovirus virions contains two external, protruding domains: an N-terminal domain (NTD) with unclear function and a C-terminal domain (CTD) that binds the host receptor, allowing for viral entry and infection. While the CTD is well studied for therapeutic interventions, the role of the NTD is far less well understood for many coronaviruses. Here, we demonstrate that the spike NTD from SARS-CoV-2 and other sarbecoviruses binds to unidentified glycans in vitro similarly to other members of the Coronaviridae family. We also show that these spike NTD (S-NTD) proteins adhere to Calu3 cells, a human lung cell line, although the biological relevance of this is unclear. In contrast to what has been shown for Middle East respiratory syndrome coronavirus (MERS-CoV), which attaches sialic acids during cell entry, sialic acids present on Calu3 cells inhibited sarbecovirus infection. Therefore, while sarbecoviruses can interact with cell surface glycans similarly to other coronaviruses, their reliance on glycans for entry is different from that of other respiratory coronaviruses, suggesting sarbecoviruses and MERS-CoV have adapted to different cell types, tissues, or hosts during their divergent evolution. Our findings provide important clues for further exploring the biological functions of sarbecovirus glycan binding and adds to our growing understanding of the complex forces that shape coronavirus spike evolution. IMPORTANCE Spike N-terminal domains (S-NTD) of sarbecoviruses are highly diverse; however, their function remains largely understudied compared with the receptor-binding domains (RBD). Here, we show that sarbecovirus S-NTD can be phylogenetically clustered into five clades and exhibit various levels of glycan binding in vitro. We also show that, unlike some coronaviruses, including MERS-CoV, sialic acids present on the surface of Calu3, a human lung cell culture, inhibit SARS-CoV-2 and other sarbecoviruses. These results suggest that while glycan binding might be an ancestral trait conserved across different coronavirus families, the functional outcome during infection can vary, reflecting divergent viral evolution. Our results expand our knowledge on the biological functions of the S-NTD across diverse sarbecoviruses and provide insight on the evolutionary history of coronavirus spike.

Identification of Distinct Immune Cell Subsets Associated With Asymptomatic Infection, Disease Severity, and Viral Persistence in COVID-19 Patients.

The cell-mediated protective and pathogenic immune responses to SARS-CoV-2 infection remain largely elusive. Here we identified 76 distinct cell subsets in the PBMC samples that were associated with various clinical presentations of COVID-19 using scRNA-seq technology coupled with a deep and comprehensive analysis of unique cell surface markers and differentially expressed genes. We revealed that (TRAV1-2+CD8+)MAIT cells and (NCAM1hiCD160+)NK cells significantly enriched in the asymptomatic subjects whereas (LAG3+CD160+CD8+)NKT cells increased in the symptomatic patients. We also observed that (CD68-CSF1R-IL1BhiCD14+)classical monocytes were positively correlated with the disease severity. Moreover, (CD33-HLA-DMA-CD14+)classical monocytes and (CLEC10A-S100A9lo)pDC were associated with the viral persistence. The GO and KEGG analyses identified enriched pathways related to immune responses, inflammation, and apoptosis. These findings may enhance our understanding of the immunopathogenesis of COVID-19 and help develop novel strategies against SARS-CoV-2 infection.

Prevalence and prognostic value of preexisting sarcopenia in patients with mechanical ventilation: a systematic review and meta-analysis.

BACKGROUND: Sarcopenia is defined as age-related loss of muscle mass, strength, and/or function in the context of aging. Mechanical ventilation (MV) is one of the most frequently used critical care technologies in critically ill patients. The prevalence of preexisting sarcopenia and the clinical impact of its prognostic value on patients with MV are unclear. This review sought to identify the prevalence and prognostic value of preexisting sarcopenia on MV patient health outcomes. METHODS: Relevant studies were identified by searching MEDLINE, Embase, and the Cochrane library and were searched for all articles published as of December 2021. The prevalence of sarcopenia was determined using the authors' definitions from the original studies. Comparisons were made between patients who did and did not have sarcopenia for prognostic outcomes, including mortality, the number of days of MV, the length of intensive care unit stay, and the length of hospital stay. Odds ratios (ORs) and weighted mean differences with 95% confidence intervals (CIs) were used for pooled analyses of the relationships between sarcopenia and prognostic outcomes. RESULTS: The initial search identified 1333 studies, 17 of which met the eligibility criteria for the quantitative analysis, including 3582 patients. The pooled prevalence was 43.0% (95% CI 34.0-51.0%; I2 = 96.7%). The pooled analyses showed that sarcopenia was related to increased mortality (OR 2.13; 95% CI 1.70, 2.67; I2 = 45.0%), longer duration of MV (MD = 1.22; 95% CI 0.39, 2.05; I2 = 97.0%), longer days of ICU stay (MD = 1.31; 95% CI 0.43, 2.19; I2 = 97.0%), and hospital stay (MD 2.73; 95% CI 0.58, 4.88; I2 = 98.0%) in patients with MV. CONCLUSION: The prevalence of sarcopenia is relatively high in patients with MV, and it will have a negative impact on the prognosis of patients. However, further, large-scale, high-quality prospective cohort studies are required.

Hypophosphatemia is an independent risk factor for AKI among hospitalized patients with COVID-19 infection.

BACKGROUND: This study sought to investigate incidence and risk factors for acute kidney injury (AKI) in hospitalized COVID-19. METHODS: In this retrospective study, we enrolled 823 COVID-19 patients with at least two evaluations of renal function during hospitalization from four hospitals in Wuhan, China between February 2020 and April 2020. Clinical and laboratory parameters at the time of admission and follow-up data were recorded. Systemic renal tubular dysfunction was evaluated via 24-h urine collections in a subgroup of 55 patients. RESULTS: In total, 823 patients were enrolled (50.5% male) with a mean age of 60.9 ± 14.9 years. AKI occurred in 38 (40.9%) ICU cases but only 6 (0.8%) non-ICU cases. Using forward stepwise Cox regression analysis, we found eight independent risk factors for AKI including decreased platelet level, lower albumin level, lower phosphorus level, higher level of lactate dehydrogenase (LDH), procalcitonin, C-reactive protein (CRP), urea, and prothrombin time (PT) on admission. For every 0.1 mmol/L decreases in serum phosphorus level, patients had a 1.34-fold (95% CI 1.14-1.58) increased risk of AKI. Patients with hypophosphatemia were likely to be older and with lower lymphocyte count, lower serum albumin level, lower uric acid, higher LDH, and higher CRP. Furthermore, serum phosphorus level was positively correlated with phosphate tubular maximum per volume of filtrate (TmP/GFR) (Pearson r = 0.66, p < .001) in subgroup analysis, indicating renal phosphate loss via proximal renal tubular dysfunction. CONCLUSION: The AKI incidence was very low in non-ICU patients as compared to ICU patients. Hypophosphatemia is an independent risk factor for AKI in patients hospitalized for COVID-19 infection.

A validation study of UCSD-Mayo risk score in predicting hospital-acquired acute kidney injury in COVID-19 patients.

INTRODUCTION: Acute kidney injury (AKI) in coronavirus disease 2019 (COVID-19) patients is associated with poor prognosis. Early prediction and intervention of AKI are vital for improving clinical outcome of COVID-19 patients. As lack of tools for early AKI detection in COVID-19 patients, this study aimed to validate the USCD-Mayo risk score in predicting hospital-acquired AKI in an extended multi-center COVID-19 cohort. METHODS: Five hundred seventy-two COVID-19 patients from Wuhan Tongji Hospital Guanggu Branch, Wuhan Leishenshan Hospital, and Wuhan No. Ninth Hospital was enrolled for this study. Patients who developed AKI or reached an outcome of recovery or death during the study period were included. Predictors were evaluated according to data extracted from medical records. RESULTS: Of all patients, a total of 44 (8%) developed AKI. The UCSD-Mayo risk score achieved excellent discrimination in predicting AKI with the C-statistic of 0.88 (95%CI: 0.84-0.91). Next, we determined the UCSD-Mayo risk score had good overall performance (Nagelkerke R2 = 0.32) and calibration in our cohort. Further analysis showed that the UCSD-Mayo risk score performed well in subgroups defined by gender, age, and several chronic comorbidities. However, the discrimination of the UCSD-Mayo risk score in ICU patients and patients with mechanical ventilation was not good which might be resulted from different risk factors of these patients. CONCLUSIONS: We validated the performance of UCSD-Mayo risk score in predicting hospital-acquired AKI in COVID-19 patients was excellent except for patients from ICU or patients with mechanical ventilation.