OBJECTIVE To compare the efficacy of ceftazidime and avibactam （CZA） monotherapy and combination therapy in the treatment of carbapenem-resistant Gram-negative bacteria （CRGNB） infections， and analyze the influencing factors. METHODS The data of patients with CRGNB infection who received CZA treatment from January 2020 to March 2025 were collected retrospectively. The patients were divided into the CZA monotherapy group （52 cases） and the CZA combination therapy group （85 cases） according to treatment regimen. The therapeutic effects of the two groups were compared， and the drug susceptibility results of isolated strains were recorded. The multivariate Logistic regression model was used to analyze the factors influencing clinical efficacy of CRGNB patients. RESULTS The bacterial clearance rate of patients was significantly higher in the CZA combination therapy group than in the CZA monotherapy group （P＝0.012）. However， when comparing the 30-day mortality rate and the clinical response rate between the two groups， no statistically significant differences were observed （P＞0.05）. Among the isolates， carbapenem-resistant Klebsiella pneumoniae had the highest sensitivity to tigecycline （87.3%） and carbapenem-resistant Pseudomonas aeruginosa showed 90.9% sensitivity to amikacin. Five isolates were resistant to CZA. The multivariate Logistic regression showed， lung infection， receiving continuous renal replacement therapy （CRRT）， and inadequate treatment courses were significantly correlated with clinical treatment failure （P＜0.05）. CONCLUSIONS For CRGNB infection， the clinical efficacy of CZA combination therapy is similar to that of monotherapy， but the combination therapy has a higher bacterial clearance rate. Lung infections， receiving CRRT and inadequate treatment courses （No. are independent risk factors for clinical treatment failure.

Objective: To investigate a SARS-CoV-2 epidemic reported in Rongcheng City, Weihai, Shandong Province. Methods: The SARS-CoV-2 nucleic acid positive patients and their close contacts were investigated, and the whole genome sequencing and genetic evolution analysis of 9 variant viruses were carried out. An infection source investigation and analysis were carried out from two sources of home and abroad, and three aspects of human, material and environment. Results: A total of 15 asymptomatic infections were reported in this epidemic, including 13 cases as employees of workshop of aquatic products processing company, with an infection rate of 21.67% (13/60). Two cases were infected people's neighbors in the same village (conjugal relation). The first six positive persons were processing workers engaged in the first process of removing squid viscera in the workshop of the company. The nucleic acid Ct value of the first time were concentrated between 15 and 29, suggesting that the virus load was high, which was suspected to be caused by one-time homologous exposure. The whole genome sequence of 9 SARS-CoV-2 strains was highly homologous, belonging to VOC/Gamma (Lineage P.1.15). No highly homologous sequences were found from previous native and imported cases in China. It was highly homologous with the six virus sequences sampled from May 5 to 26, 2021 uploaded by Chile. The infection source investigation showed that the company had used the squid raw materials captured in the ocean near Chile and Argentina from May to June 2021 over the last 14 days. Many samples of raw materials, products and their outer packages in the inventory were tested positive for nucleic acid. Conclusion: This epidemic is the first local epidemic caused by the VOC/Gamma of SARS-CoV-2 in China. It is speculated that the VOC/Gamma, which was prevalent in South America from May to June 2021, could be imported into China through frozen squid.
Humans ; SARS-CoV-2 ; COVID-19 ; Epidemics ; China/epidemiology*