Antimicrobial peptides are a type of small-molecule peptide that widely exist in nature and are components of the innate immunity of almost all living things. They play an important role in resisting foreign invading microorganisms. Antimicrobial peptides have a wide range of antibacterial activities against bacteria, fungi, viruses and other microorganisms. They are active against traditional antibiotic-resistant strains and do not easily induce the development of drug resistance. Therefore, they have become a hot spot of medical research and are expected to become a new substitute for fighting microbial infection and represent a new method for treating drug-resistant bacteria. This review briefly introduces the source and structural characteristics of antimicrobial peptides and describes those that have been used against common clinical microorganisms (bacteria, fungi, viruses, and especially coronaviruses), focusing on their antimicrobial mechanism of action and clinical application prospects.

GST-HG171 is a potent, broad-spectrum, orally bioavailable small-molecule 3C like protease inhibitor that has demonstrated greater potency and efficacy compared to Nirmatrelvir in pre-clinical studies. We aimed to evaluate the efficacy and safety of orally administered GST-HG171 plus Ritonavir in patients with coronavirus disease 2019 (COVID-19) infected with emerging XBB and non-XBB variants. This randomised, double-blind, placebo-controlled phase 2/3 trial was conducted in 47 sites in China among adult patients with mild-to-moderate COVID-19 with symptoms onset ≤72 h. Eligible patients were randomised 1:1 to receive GST-HG171 (150 mg) plus Ritonavir (100 mg) or corresponding placebo tablets twice daily for 5 days, with stratification factors including the risk level of disease progression and vaccination status. The primary efficacy endpoint was time to sustained recovery of clinical symptoms within 28 days, defined as a score of 0 for 11 COVID-19-related target symptoms for 2 consecutive days, assessed in the modified intention-to-treat (mITT) population. This trial was registered at ClinicalTrials.gov (NCT05656443) and Chinese Clinical Trial Registry (ChiCTR2200067088). Between Dec 19, 2022, and May 4, 2023, 1525 patients were screened. Among 1246 patients who underwent randomisation, most completed basic (21.2%) or booster (74.9%) COVID-19 immunization, and most had a low risk of disease progression at baseline. 610 of 617 who received GST-HG171 plus Ritonavir and 603 of 610 who received placebo were included in the mITT population. Patients who received GST-HG171 plus Ritonavir showed shortened median time to sustained recovery of clinical symptoms compared to the placebo group (13.0 days [95.45% confidence interval 12.0–15.0] vs. 15.0 days [14.0–15.0], P = 0.031). Consistent results were observed in both SARS-CoV-2 XBB (45.7%, 481/1053 of mITT population) and non-XBB variants (54.3%, 572/1053 of mITT population) subgroups. Incidence of adverse events was similar in the GST-HG171 plus Ritonavir (320/617, 51.9%) and placebo group (298/610, 48.9%). The most common adverse events in both placebo and treatment groups were hypertriglyceridaemia (10.0% vs. 14.7%). No deaths occurred. Treatment with GST-HG171 plus Ritonavir has demonstrated benefits in symptom recovery and viral clearance among low-risk vaccinated adult patients with COVID-19, without apparent safety concerns. As most patients were treated within 2 days after symptom onset in our study, confirming the potential benefits of symptom recovery for patients with a longer duration between symptom onset and treatment initiation will require real-world studies. Fujian Akeylink Biotechnology Co., Ltd.

Background: Under the wave of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) variant Omicron epidemic, the number of infectious cases has increased dramatically in Jilin Province, China since March 2022.The clinical features and severity of SARS-CoV-2 Omicron variant infection in tuberculosis (TB) patients are not yet clear.Methods: Data were obtained from 153 patients with the Omicron variant and TB coinfection and 153 non-TB COVID-19 patients who had been hospitalized at Changchun Infectious Disease Hospital from March to June 2022.Results: Among these coinfection patients, 17 patients showed COVID-19-related pneumonia on chest imaging and 11 were diagnosed with severe COVID-19. The median duration of SARS-CoV-2 clearance was 13 days. The negative conversion time was associated with age, COVID-19-related pneumonia and antibody IgG. A higher white blood cell count, a lower lymphocyte percentage, a higher CRP level, and a higher D-dimer level were found in the severe group. Age and increased PCT were individual risk factors for the severity of COVID-19. Compared with the non-TB patients, the coinfection patients had higher severity of COVID-19 and the elder coinfection patients had a longer negative conversion time.Conclusion: This study found an association between age, pneumonia, antibody IgG and RNA negative conversion time in COVID-19 and TB coinfection patients, and age and increased PCT were risk factors for the severity of COVID-19.

To delineate the clinical differences between Pneumocystis jirovecii pneumonia (PJP) and colonization, identify independent risk factors associated with PJP development, and construct a multidimensional diagnostic model to address the ongoing clinical challenge of accurately distinguishing P. jirovecii infection status in practice. This retrospective study analyzed the clinical characteristics, imaging findings, and laboratory parameters of patients who tested positive for P. jirovecii by next-generation sequencing (NGS) at the First Hospital of Jilin University between January 2014 and October 2024. Multivariable logistic regression was performed to determine independent predictors of PJP. Of the 292 patients included in the analysis (210 diagnosed with PJP and 82 classified as colonized), those with PJP had significantly higher rates of immunosuppression (64.4% vs. 9.9%, P < 0.001) and markedly increased P. jirovecii sequence counts from NGS (median: 1,686 vs. 4, P < 0.001).Human immunodeficiency virus coinfection, decreased lymphocyte count, elevated BDG levels, and increased LDH levels were identified as independent risk factors for PJP. A diagnostic model incorporating these four variables demonstrated excellent predictive capability, yielding an area under the receiver operating characteristic curve of 0.892 (P < 0.001; 95% confidence interval: 0.855–0.929). The optimal NGS sequence count threshold for differentiating PJP from colonization was determined to be 37, achieving a sensitivity of 91% and a specificity of 87.8% (area under the receiver operating characteristic curve: 0.964). The developed risk prediction model—comprising lymphocyte count, BDG, and LDH levels—facilitates rapid, pre-NGS clinical risk stratification for PJP, enabling prompt and informed therapeutic decision-making. When NGS results yield a P. jirovecii-specific sequence reads below the cutoff value of 37, a definitive diagnosis of PJP is unlikely. However, such findings should be interpreted in the context of the patient’s clinical presentation and assessed using the diagnostic model to ensure an accurate evaluation of infection status.

Introduction: Hemophagocytic lymphohistiocytosis (HLH), a rare and deadly disease, is typically classified as either primary (familial) or secondary (acquired), depending on the etiology and underlying cause. Secondary HLH often develops in the presence of infectious, malignant, rheumatologic, or metabolic conditions, with infections, especially Epstein–Barr virus (EBV) infection, being among the leading causes. Brucella infection-induced HLH is relatively rare, with only eight cases reported in the past decade, all of which had a favorable prognosis following timely diagnosis and treatment.Case description: A 53-year-old man with brucellosis who developed secondary HLH and multiple organ dysfunction presented to our hospital with a 2-month history of fever and abnormal liver enzymes. Initial blood culture following admission confirmed Brucella spp. in the aerobic bottle after ⁓87.85 h of incubation. However, after the initial discharge, the patient did not adhere to the prescribed antibiotic therapy and subsequently developed symptoms of fever and abdominal discomfort, and was readmitted to our hospital. Laboratory examination also revealed pancytopenia. An additional blood culture further revealed the growth of Brucella spp. in the aerobic bottle after ⁓113.67 h of incubation. Other findings included decreased fibrinogen, increased ferritin, increased soluble IL-2 receptor α chain (sCD25), decreased Natural Killer (NK) cell activity, presence of hemophagocytic cells in the bone marrow smear, splenomegaly, and abnormal liver and kidney functions. The HScore score was 230 points. A thorough assessment was made, which led to the exclusion of other possible diseases, culminating in the identification of Brucella infection as the most probable cause of HLH. Consequently, the patient was given anti-infection (doxycycline, levofloxacin, etimicin, and rifampin), glucocorticoids (GCs), human immunoglobulin (HIG), and other symptomatic supportive treatments, which ultimately improved his condition.Conclusion: Despite the generally poor prognosis of HLH patients, those with Brucella-induced HLH may have a favorable outcome with prompt intervention. Conversely, a delayed treatment could increase the risk of HLH onset and progression, leading to death in severe cases.