RESUMO
PURPOSE: This observational study aimed to identify the independent risk factors for both the acquisition and mortality of carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) bacteremia and further assess the in vitro antimicrobial activities of ceftazidime-avibactam (CAZ/AVI) and aztreonam-avibactam (ATM/AVI) against recent CRE bacteremic isolates. PATIENTS AND METHODS: This observational study was conducted to reveal the risk factors and mortality rate for CP-CRE bacteremia between 2012 and 2018 and also evaluate the in vitro antimicrobial activities of CAZ/AVI and ATM/AVI against recent CRE bacteremic isolates from 2016 to 2018. RESULTS: A total of 81 non-repetitive isolates were collected from 2012 to 2018, with 67.90% (55/81) being CP-CRE. Old age (P = 0.01), transfusion [odds ratio (OR): 17.19; 95% CI: 3.15-93.72; P = 0.001], longer ICU stay (P = 0.02), cancer (OR: 15.91; 95% CI: 3.56-71.37; P < 0.001), and previous carbapenem exposure (OR: 27.86; 95% CI: 5.03-154.19; P = 0.001) were identified as independent risk factors for the acquisition of CP-CRE bacteremia compared with the ESBL bacteremia. The in vitro antimicrobial activities of CAZ/AVI and ATM/AVI against the CRE bacteremic isolates from 2016 to 2018 showed a respective susceptibility rate of 70.68% (41/58) and 100.00% (58/58). CONCLUSION: The findings indicated that both CP-CRE/non-CP-CRE stratification and CRE resistance mechanism determination were necessary for better guiding the clinical management of CRE bacteremia: ATM/AVI probably works with both non-CP-CRE and CP-CRE bacteremia, even the most notorious double-carbapenemase producer with porin loss/deficiency, whereas CAZ/AVI works with most of the non-CP-CRE and KPC-producers in the region.
RESUMO
BACKGROUND AIMS: This study was initiated to investigate the efficacy of myocardial fibrosis intervention via signal transducer and activators of transcription (STAT) signaling using bone marrow (BM) mesenchymal stromal cells (MSC) with the aid of bispecific antibody (BiAb) and ultrasound-mediated microbubbles (MB). METHODS: BiAb (anti-CD29 × anti-myosin light chain antibody; AMLCA) was prepared and combined with isolated MSC from male mice and transfused into female mice with isoproterenol-induced myocardial fibrosis via the tail vein, followed by MB (MSC + BiAb + MB). This study included seven groups: MSC + BiAb + MB; MSC; BiAb; MB; MSC + BiAb; untreated; and control. Five weeks after treatment, expression levels of the sex-determining region of Y-chromosome (SRY), matrix metalloproteinases (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-1 and vascular endothelial growth factor (VEGF) in myocardium were detected by fluorescent quantitative real-time polymerase chain reaction (qRT-PCR). Collagen distribution was observed using Sirius Red staining. The protein expression of signal transducer and activators of transcription (STAT)1 and STAT3 was detected by Western blot. RESULTS: The highest homing number of MSC was in the MSC + BiAb + MB group, second highest in the MSC + BiAb group, and lowest in MSC alone. Compared with the untreated group, MSC + BiAb + MB, MSC + BiAb and MSC groups had decreased levels of MMP-9, TIMP-1, STAT1 and collagen deposition, and increased levels of STAT3. Upregulated STAT3 and downregulated TIMP-1 were significantly different in MSC + BiAb + MB compared with MSC alone or MSC + BiAb. CONCLUSIONS: The homing rate and repairing efficacy of MSC improved with treatment utilizing a combination of BiAb and MB. MSC can improve MMP-TIMP expression in injured myocardium and interfere with myocardial fibrosis after homing, a mechanism that may be related to the STAT-mediated signaling pathway.
