Background: Immunosuppression caused by immune cell apoptosis and an imbalance of T helper 2 cells (T_H2) and T helper 1 cells (T_H1), is associated with poor outcomes in septic patients. Esmolol was reported to improve survival by modulating immune responses in septic shock. Whether esmolol could alleviate sepsis-induced immunosuppression and the optimal dose are unclear. Methods: Four hours after cecal ligation and puncture (CLP), Wistar rats were randomized into CLP, CLP + E-5 (esmolol: 5 mg·kg⁻¹·h⁻¹) and CLP + E-18 (esmolol: 18 mg·kg⁻¹·h⁻¹) groups. Eight rats were underwent sham operation. Eighteen hours after CLP, hemodynamics and organ histological injuries were evaluated, peripheral blood mononuclear cells apoptosis and T-lymphocyte subsets counts were determined by flow cytometry, and the expression of p-Akt, Bcl-2, cleaved Caspase-3, and p-Erk1/2 in splenic CD4⁺ T-lymphocytes was determined by western blot and immunohistochemistry. β₁-Adrenoreceptor expressions were evaluated using real-time polymerase chain reaction and immunohistochemistry. Results: Cecal ligation and puncture induced tachycardia, hypotension, hyperlactatemia, and multiple organ injury. Heart rate was unchanged in the CLP + E-5 group but decreased in the CLP + E-18 group. Hypotension, lactatemia, and multiple organ injuries were improved only in the CLP + E-5 group. T-lymphocyte apoptosis and T_H2/T_H1 ratio was decreased in CLP + E-5 but not in CLP + E-18. p-Akt and Bcl-2 expressions were increased, while cleaved Caspase-3 and p-Erk1/2 expressions were decreased in CLP + E-5. β₁-Adrenoreceptor expressions were unchanged in both CLP + E-5 and CLP + E-18 groups. Conclusions: Low dose of esmolol reduced T-lymphocyte apoptosis and restored T_H2/T_H1 ratio in septic shock. Esmolol might modulate Akt/Bcl-2/Caspase-3 pathway to relieve T-lymphocyte apoptosis and inhibit Erk1/2 activity to decrease T_H0 differentiation to T_H2. Esmolol may be a potential immunoregulator of septic shock.

Background: COVID-19 has been widely spreading. We aim to examine adaptive immune cells in non-severe patients with persistent SARS-CoV-2 shedding. Methods: 37 non-severe patients with persistent SARS-CoV-2 presence transferred to Zhongnan hospital of Wuhan University were retrospectively recruited to PP (persistently positive) group, which was further allocated to PPP group (n=19) and PPN group (n=18), according to their testing results after 7 days (N=negative). Epidemiological, demographic, clinical and laboratory data were collected and analyzed. Data from age- and sex-matched non-severe patients at disease onset (PA [positive on admission] patients, n=37), and lymphocyte subpopulation measurements from matched 54 healthy subjects were extracted for comparison. Results: Compared with PA patients, PP patients had much improved laboratory findings, including WBCs, neutrophils, lymphocytes, neutrophil-to-lymphocyte ratio, albumin, AST, CRP, SAA, and IL-6. The absolute numbers of CD3 ⁺ T cells, CD4 ⁺ T cells, and NK cells were significantly higher in PP group than that in PA group, and were comparable to that in healthy controls. PPP subgroup had markedly reduced B cells and T cells compared to PPN group and healthy subjects. Finally, paired results of these lymphocyte subpopulations from 10 PPN patients demonstrated that the number of T cells and B cells significantly increased when the SARS-CoV-2 tests turned negative. Conclusion: Persistent SARS-CoV-2 presence in non-severe COVID-19 patients is associated with reduced numbers of adaptive immune cells. Monitoring lymphocyte subpopulations could be clinically meaningful in identifying fully recovered COVID-19 patients. Summary: Defects in adaptive immune system, including reduced T cells and B cells, were frequently observed in non-severe COVID-19 patients with persistent SARS-CoV-2 shedding. Assessment of immune system could be clinically relevant for discharge management.

Background: Carbapenem-resistant Gram-negative bacilli (CRGNB) often cause nosocomial infections difficult to treat. Their widespread dissemination, associated high mortality, and increasing disease burden constitute a significant global public health challenge. This situation is further exacerbated by mixed CRGNB infections, which exhibit elevated mortality rates and increased therapeutic complexity. Thus, it is imperative to establish effective antibiotic strategies with minimal adverse effects to address these polymicrobial infections. We present this case to evaluate the efficacy of sulbactam-durlobactam (SUL-DUR) combined with aztreonam for treating mixed carbapenem-resistant Acinetobacter baumannii (CRAB) and metallo-β-lactamase (MBL)-producing carbapenem-resistant Enterobacterales (CRE) infections, also exploring the potential mechanisms. Case Description: An elderly patient with uncontrolled chronic obstructive pulmonary disease (COPD) was admitted presenting with dyspnea, bloody sputum, and somnolence. Etiological workup revealed a pulmonary coinfection with CRAB and MBL-producing CRE. The infection proved refractory to multiple rounds of advanced antibiotic therapy, including meropenem, ceftazidime-avibactam, and a combination of polymyxin B with eravacycline. Guided by antimicrobial susceptibility testing (AST) and clinical guidelines, a regimen of SUL-DUR combined with aztreonam was initiated. This therapeutic strategy led to a successful clinical outcome, with no evidence of disease recurrence during a 2-month follow-up period. Conclusions: This case highlights the significant efficacy of SUL-DUR combined with aztreonam in managing the clinically formidable challenge of mixed CRAB and MBL-producing CRE infections, offering a valuable reference for treating such conditions.

Acinetobacter baumannii is a pathogen that typically causes nosocomial infections. Its resistance to multiple antibiotics poses significant challenges for treatment. Fulminant Mycoplasma pneumoniae pneumonia (FMPP) is relatively rare despite Mycoplasma pneumoniae pneumonia is common among children and young adults. We present a case involving the concurrence of FMPP and lung abscess and empyema caused by extensively drug-resistant (XDR) A.baumanii. The patient was successfully treated through a novel and effective antibacterial regimen combined with timely drainage.

Background: Beta-blockers have been reported to exert potential beneficial effects in sepsis in recent years. However, their clinical application in sepsis remains limited due to concerns regarding hemodynamic impacts. This study aims to explore whether premorbid use of beta-blockers is associated with improvements in cardiac function and favorable clinical outcomes among patients with sepsis. Methods: This single-center, retrospective cohort study was conducted in the Intensive Care Unit (ICU) of a university-affiliated hospital. All patients diagnosed with sepsis admitted between August 2022 and March 2024 were enrolled. Exclusion criteria included age 18 years, hospitalization duration 48 hours, a history of severe underlying cardiac conditions, and incomplete clinical records. Primary outcomes included myocardial injury markers, echocardiographic parameters, and electrocardiographic indices to assess cardiac function. Secondary outcome was mortality. Results: Among 1005 septic patients, 228 had received premorbid beta-blockers. No significant difference in baseline disease severity was observed between the two groups. Patients with premorbid beta-blocker exposure had lower levels of cardiac troponin I (TnI, 87.9 [IQR, 23.4-306.0] vs 142.0 [IQR, 37.8-481.2]), lactic dehydrogenase (LDH, 274.0 [IQR, 175.0-496.0] vs 319.0 [IQR, 229.0-456.8]), and B-type natriuretic peptide (BNP, 267.9 [IQR, 118.1-1065.1] vs 509.3 [IQR, 184.8-1203.0]). Echocardiographic assessments revealed that premorbid beta-blockers were associated with a higher left ventricular ejection fraction (LVEF, 58% [IQR 52-60] vs 55% [IQR 50-60]). Additionally, premorbid beta-blockers were linked to lower 14-day (13.6% [IQR 9.1-18.1] vs 21.5% [IQR 18.6-24.4]), 28-day (17.5% [IQR 12.6-22.5] vs 27.4% [IQR 24.3-30.6]), and in-hospital (18.9% [IQR 13.7-24.0] vs 28.8% [IQR 25.6-32.0]) mortality rates. Conclusions: Among septic patients, premorbid beta-blockers are associated with preserved cardiac function and improved clinical outcomes. These findings highlight the need for prospective or randomized controlled trials to further explore the potential cardioprotective role of beta-blockers in sepsis.