OBJECTIVE To investigate the prevalence of ?-lactamases in nosocomial infections of Enterobacter cloacae,study the different genotyping of ?-lactamases,and analyze its independence in drug resistance. METHODS AmpC ?-lactamases and ESBLs were detected by three-dimensional extract tests.PCR was used to determine the genotype of ?-lactamases and their resistance to 13 kinds of antibiotics was detected by Kirby-Bauer method. RESULTS The sensitivity test showed that they were resistant to the most antibiotics.Among the 80 ESBLs strains,29 strains carried ESBLs gene,3 strains carried two different gene.Such as:TEM existed in 6,SHV-Ⅰ existed in 2,CTX-M-2 existed in 5,CTX-M-3 existed in 8 and CTX-M-9 existed in 11 strains.Twenty-six strains carried ampC.The resistant rate of SSBLs-producing E.cloacae to 12 antibiotics except merapenem was 66.7-100.0%.SSBLs strains of E.cloacae were higher than AmpC ?-lactamases in resistance to levofloxacin,cefepime,aztronem and trimethoprim sulpfamethoxazole with significant difference(P

Objective:To analyze the incidence, risk factors and occurrence time of radiation pneumonia (RP) and immune checkpoint inhibitor-related pneumonia (CIP) in patients with lung cancer and lung metastatic cancer who received both thoracic radiotherapy and immunotherapy.Methods:The clinicopathological data of 137 patients with lung cancer and lung metastatic cancer receiving thoracic radiotherapy and at least one cycle of immunotherapy from January 2019 to January 2022 in Renmin Hospital of Wuhan University were retrospectively analyzed. The occurrence of RP and CIP was determined according to the clinical symptoms and thin-slice chest CT. The risk factors of symptomatic RP were evaluated by univariate and multivariate analyses of clinical data and treatment plan. The relationship between the occurrence time of symptomatic RP and the sequence of thoracic radiotherapy and immunotherapy was compared.Results:In the 137 patients with lung cancer and lung metastatic cancer who received both thoracic radiotherapy and immunotherapy, symptomatic RP was observed in 42 patients (30.7%) , including grade 2 RP in 33 patients (24.1%) , grade 3 RP in 6 patients (4.4%) , grade 4 RP in 1 patient (0.7%) , and grade 5 RP in 2 patients (1.5%) . The incidence of symptomatic RP was 40.0% (28/70) in patients who received thoracic radiation concurrent with immunotherapy and 20.9% (14/67) in non-synchronous patients, and the incidence of severe RP was 10.0% (7/70) and 3.0% (2/67) respectively. CIP was observed in 11 (8.0%) of 137 patients, including grade 2 CIP in 4 patients (2.9%) , grade 3 CIP in 6 patients (4.4%) , grade 5 CIP in 1 patient (0.7%) . There were 54.5% (6/11) of CIP patients with prior or concurrent symptomatic RP. Univariate analysis showed that smoking history ( χ2=9.85, P=0.002) , chronic obstructive pulmonary disease (COPD) history ( χ2=31.34, P<0.001) , thoracic radiotherapy concurrent with immunotherapy ( χ2=5.88, P=0.015) , total radiotherapy dose ( χ2=8.57, P=0.003) were associated with symptomatic RP. Multivariate logistic regression analysis showed that COPD history ( OR=9.96, 95% CI: 3.40-29.14, P<0.001) , thoracic radiotherapy concurrent with immunotherapy ( OR=2.84, 95% CI: 1.15-7.00, P=0.024) , and total radiotherapy dose ≥60 Gy ( OR=4.76, 95% CI: 1.68-13.50, P=0.003) were independent risk factors for symptomatic RP. RP occurred earlier in patients who received immunotherapy before thoracic radiotherapy [68.5 d (47.0 d, 101.8 d) ] than in patients who received immunotherapy after thoracic radiotherapy [117.5 d (79.0 d, 166.3 d) ], with a statistically significant difference ( Z=2.54, P=0.010) . Conclusion:The incidence of symptomatic RP is high in patients who receive both thoracic radiotherapy and immunotherapy. The history of COPD, thoracic radiotherapy concurrent with immunotherapy, and the total radiotherapy dose ≥60 Gy are independent influencing factors of symptomatic RP in patients with thoracic radiotherapy combined with immunotherapy. Symptomatic RP occurs earlier in patients who receive immunotherapy before thoracic radiotherapy than in patients who receive immunotherapy after thoracic radiotherapy.

The combination of thoracic radiotherapy and immunotherapy is increasingly widely used in clinical practice, which not only brings survival benefits but also increases the incidence of pneumonitis. The occurrence of pneumonitis affects the subsequent immunotherapy and can be life-threatening in severe cases. The occurrence and severity of pneumonitis after combination therapy depends on a variety of factors, including patient's age, physical strength, pulmonary function, race, combination therapy mode, radiotherapy dose parameters, type of immune checkpoint inhibitor, history of checkpoint inhibitor-related pneumonitis or radiation pneumonitis, serum indexes and so on. At present, further research is needed to find out the influencing factors of the occurrence and severity of pneumonitis attributed to combined therapy, so as to better avoid, predict, identify and treat related pneumonitis in clinical practice.