Incidence and clinical features of HHV-7 detection in lower respiratory tract in patients with severe pneumonia: a multicenter, retrospective study.

PURPOSE: The significance of detecting human herpesvirus 7 (HHV-7) in the lower respiratory tract of patients with severe pneumonia is unclear. This study aims to evaluate the clinical characteristics and prognosis of detecting HHV-7 in the lower respiratory tract of patients with severe pneumonia. METHODS: Patients with severe pneumonia requiring invasive mechanical ventilation and underwent commercial metagenomic next-generation sequencing (mNGS) testing of bronchoalveolar lavage fluid from January 2019 to March 2023 were enrolled in 12 medical centers. Clinical data of patients were collected retrospectively, and propensity score matching was used for subgroup analysis and mortality assessment. RESULTS: In a total number of 721 patients, 45 cases (6.24%) were identified with HHV-7 positive in lower respiratory tract. HHV-7 positive patients were younger (59.2 vs 64.4, p = 0.032) and had a higher rate of co-detection with Cytomegalovirus (42.2% vs 20.7%, p = 0.001) and Epstein-Barr virus (35.6% vs 18.2%, p = 0.008). After propensity score matching for gender, age, SOFA score at ICU admission, and days from ICU admission to mNGS assay, there was no statistically significant difference in the 28-day mortality rate between HHV-7 positive and negative patients (46.2% vs 36.0%, p = 0.395). Multivariate Cox regression analysis adjusting for gender, age, and SOFA score showed that HHV-7 positive was not an independent risk factor for 28-day mortality (HR 1.783, 95%CI 0.936-3.400, p = 0.079). CONCLUSION: HHV-7 was detected in the lungs of 6.24% of patients with severe pneumonia. The presence of HHV-7 in patients with severe pneumonia requiring invasive mechanical ventilation is associated with a younger age and co-detected of Cytomegalovirus and Epstein-Barr virus. While HHV-7 positivity was not found to be an independent risk factor for mortality in this cohort, this result may have been influenced by the relatively small sample size of the study.

Clinical characteristics and prognosis of patients with severe pneumonia with Pneumocystis jirovecii colonization: A multicenter, retrospective study.

BACKGROUND: For decades, the incidence and clinical characteristics of Pneumocystis jirovecii (P. jirovecii) colonization in patients with severe pneumonia was remained unclear. RESEARCH QUESTION: What are the clinical features and outcomes associated with P. jirovecii colonization in individuals diagnosed with severe pneumonia? STUDY DESIGN AND METHODS: In this multicenter, retrospective, matched study, severe pneumonia patients who underwent bronchoalveolar lavage clinical metagenomics from 2019 to 2023 in the ICUs of 17 medical centers were enrolled. Patients were diagnosed based on clinical metagenomics, pulmonary CT scans, and clinical presentations. Clinical data were collected retrospectively, and according to propensity score matching and Cox multivariate regression analysis, the prognosis of patients with P. jirovecii colonization was compared to that of P. jirovecii-negative patients. RESULTS: 40% of P. jirovecii positive patients are considered to have P. jirovecii colonization. P. jirovecii colonization group had a higher proportion of patients with immunosuppression and a lower lymphocyte count compared to P. jirovecii-negative group. More frequent detection of cytomegalovirus, Epstein-Barr virus, human herpesvirus-6B, human herpesvirus-7, and torque teno virus in the lungs was associated with P. jirovecii colonization than with P. jirovecii negativity. By constructing two cohorts through propensity score matching, we incorporated codetected microorganisms and clinical features into a Cox proportional hazards model and revealed that P. jirovecii colonization was an independent risk factor for mortality in severe pneumonia patients. According to sensitivity analyses, which included or excluded codetected microorganisms, as well as patients not receiving TMP-SMX treatment, similar conclusions were reached. INTERPRETATION: Immunosuppression and a reduced lymphocyte count were identified as risk factors for P. jirovecii colonization in non-PCP patients. More frequent detection of various viruses was observed in P. jirovecii colonization patients, and P. jirovecii colonization was associated with an increased 28-day mortality in patients with severe pneumonia.

Dual resource utilization for tannery sludge: Effects of sludge biochars (BCs) on volatile fatty acids (VFAs) production from sludge anaerobic digestion.

Resource utilization of organic matters in tannery sludge has drawn great attention. In this paper, the influences of sludge biochars (BCs) on volatile fatty acids (VFAs) production from the anaerobic digestion of sludge supernatant (SST) were investigated. Experimental results demonstrated that the VFAs yields improved in the presence of BCs with rich functional groups. The maximum yield of VFAs was 1037.5 mg/g SCOD with the addition of BC-1 biochar (zeta potential -50.42 mV). BCs decreased ammonia nitrogen concentration, thus reducing inhibition for bacteria during the anaerobic digestion. Microbial community analysis indicated that the BCs affected microbial community structures and contributed to a favorable environment for bacteria. Especially, the BC-1 biochar with rich functional groups enhanced the relative abundance of acid-forming bacteria (Clostridiales). A dual strategy was proposed to improve the resource utilization efficiency for tannery sludge.

Roles of hydrothermal-alkaline treatment in tannery sludge reduction: rheological properties and sludge reduction mechanism analysis.

The hydrothermal-alkaline treatment (HAT) is an efficient sludge reduction method. However, the roles of HAT in tannery sludge reduction are not very clear. In this study, the sludge reduction mechanism of HAT was explored. The results showed that HAT had good performance for the organic dissolution of tannery sludge. The reduction of the sludge mass was calculated by the mass of the separated wet sludge solid (4000 rpm, 10 min) before and after HAT. The HAT parameters for sludge reduction (SR) were optimized by the Box-Behnken, and the sludge reduction was 62.5% under optimal conditions (198 °C, 87 min and 8.7 g L-1 NaOH). The soluble organics, especially a polysaccharide (PS) and ammonia nitrogen (NH3-N), showed a close correspondence with the SR ratio. The rheological properties of the sludge indicated that the reticular structures in the sludge were destroyed after HAT. The tannery sludge solid became more pyknotic than raw sludge after the hydrothermal-alkaline treatment. The tannery sludge reduction can be attributed to the damage of reticular structures, organic dissolution and release of bound water.