Objective To investigate the role of mitochondrial autophagy mediated by PINK1 (homologous phosphatase tensin induced kinase 1) /Parkin (Parkinson’s protein) signaling pathway in severe pneumonia of rats. Methods Twenty rats were randomly divided into control group and model group (severe pneumonia model), with 10 rats in each group, to explore the effects of severe pneumonia on lung function and pathology in rats. Then, 30 rats were randomly divided into control group, model group and mdivi-1 (mitochondrial autophagy inhibitor) group, with 10 rats in each group, to further explore the effects of severe pneumonia on mitochondrial autophagy indicators of rats. ResultsCompared with the control group, the resting ventilation volume [(3.44±0.22) vs. (1.58±0.18) mL/min] and airway resistance ratio (77.48±3.84 vs. 47.76±5.54) in the model group were decreased (P<0.05). In the model group, the lung tissue was injured and a large number of inflammatory cells were infiltrated. The protein and mRNA expression levels of Parkin, PINK1 and microtubule-associated protein1 light chain 3 in lung tissues of model group were increased (P<0.05). Compared with model group, the ratio of resting ventilator-to-airway resistance in mdivi-1 group increased (P<0.05). The injury and inflammatory infiltration of lung tissue were improved in mdivi-1 group. The expression levels of Parkin, PINK1 and microtubule-associated protein1 light chain 3 protein and mRNA in lung tissues of mdivi-1 group were decreased (P<0.05). Conclusion Mdivi-1 can improve the abnormal lung function structure in rats with severe pneumonia, and the mechanism may be related to mitochondrial autophagy mediated by PINK1/Parkin signaling pathway.
Objective To investigate the antibiotic resistance and their genetic homology of stenotrophomonas maltophilia isolated from January 2005 to February 2006 at intensive care unit（ICU） of 6 hospitals in Bejing area.Methods The minimal inhibitory concentration（MIC） of 12 antibiotics against 82 strenotrophomonas maltophilia was determined by broth dilution method.PFGE was used to analyze the homology of 82 stenotrophomonas maltophilia.Results The drug sensitivity tests in vitro showed these strains were resistance to commonly-used antibiotics.Antibiotics with sensitive rate over 50% included Doxycycline, gatifloxacin,cefoperazone-sulbactam,levofloxacin,Compound sulfamethoxazole,Ceftazidime and ticarcillin- clavulanate. 7-18 DNA bands of different size were present in the gel and different homology was shown among the 82 strains.Four couples with homology over 85% were isolated from the same ICU.Three strain were same clones in PLA General Hospitals first hospital.2 couples from the different wards had homology of 80.6% and 79.6% of，respictively.Others strains had either poor or no homology.Conclusions No clonal outbreak is certified at ICU of 6 hospitals in Beijing area. There are only vertical dissemination of single clone in 6 ICU wards.PFGE is an effective approach for drug resistance test and epidemic analysis.
ObjectiveTo detect the expression level of phosphate and tension homolog deleted on chromsome ten(PTEN) and its downstream signal molecules phosphorylated protein kinase B (p-AKT) in liver cells of rats during intermittent hypoxia,to investigate the effect of PTEN and p-AKT of liver cells on insulin resistance which intermittent hypoxia is relevant. MethodsA total of 24 healthy male SD rats were selected and divided into 3 groups randomly,ie.CIA (chronic intermittent air) group,CIH4 (chronic intermittent hypoxia for 4 weeks) group,and CIH8 (chronic intermittent hypoxia for 8 weeks) group. The fasting blood glucose,fasting insulin,PTEN and p-AKT expressions in the liver cells were detected. The insulin resistance was evaluated systematically by the insulin sensitive index (ISI) and homeostasis model assessment of insulin resistance (HOMA-IR). Average gray value was used to represent the protein expressions of PTEN and p-AKT. ResultsCompared with CIA group,the decline of ISI in CIH4 group and CIH8 group was significant (P<0.05). Furthermore,the decline in CIH8 group was more significant than that in CIH4 group (P<0.05). Compared with CIA group,the rise of HOMA-IR in CIH4 and CIH8 groups was statistically significant (P<0.05). In addition,the rise in CIH8 group was more significant than that in CIH4 group (P<0.05). Compared with CIA group,there was a significant rise in the protein expressions of PTEN in CIH4 and CIH8 groups (P<0.05). Compared with CIH4 group,the rise of the protein expressions of PTEN in CIH8 group was still statistically significant (P<0.05). Compared with CIA group,there was a significant decline in the protein expressions of p-AKT in CIH4 and CIH8 groups (P<0.05). Compared with CIH4 group,the decline of protein expression of p-AKT in CIH8 group was still of statistical significance (P<0.05). There was a significantly increasing trend for the expression of PTEN in the liver cells of rats with intermittent hypoxia along with the decline of ISI and rise of HOMA-IR. The expression increased significantly with the longer duration of intermittent hypoxia. The expression of p-AKT in liver cells of rats with intermittent hypoxia decreased along with the decline of ISI and rise of HOMA-IR. Furthermore,the decline tendency was more significant with the long duration of intermittent hypoxia. ConclusionThe fasting blood glucose of rats and insulin level increase due to the chronic intermittent hypoxia,resulting in the insulin resistance. The degree of insulin resistance increases with the longer duration of intermittent hypoxia. The expression of PTEN protein increases with intermittent hypoxia,and that of p-AKT protein decreases,which is obviously correlated with ISI and HOMA-IR. It is indicated that the PTEN protein possibly play an important role in the mechanism of insulin resistance for rats with intermittent hypoxia.
Objective To investigate the drug resistance and homogeneous analysis of Acinetobacter baumanii in emergency intensive care unit ( EICU) . Methods Four multidrug-resistant Acinetobacter baumannii ( MDR-Ab) strains isolated fromnosocomial inpatients fromJuly 25 to September 7 in 2009 were collected and tested for drug sensitivity and MIC determination as well. The A. baumannii isolates were typed with pulsed-field gel electrophoresis ( PFGE) to determine whether they derived fromthe same clone.Results Four isolates from nosocomial inpatients were resistant to multiple antibiotics including carbapenem. The PFGE types identified from four isolates were A and B. The A. baumannii isolates did not derived from the same clone. Conclusion The prevalence of nosocomial infection is not due to transmission of the same strains among different individuals in EICU.
Objective To analyze the drug resistance genes, virulence genes and homologies of carbapenem-resistant Klebsiella pneumoniae (CRKP) colonized and infected patients in surgical intensive care unit based on whole genome sequencing. Methods Whole genome sequencing analysis was performed on CRKP infected strains isolated from the Department of General Surgery Intensive Care Unit and the Department of Liver Surgery Intensive Care Unit of Zhongshan Hospital, Fudan University in March 2021 and CRKP colonized strains isolated from the above departments between January and March 2021. The drug resistance genes, virulence genes and homologies of the strains were analyzed. ResultsA total of 16 CRKP strains were included, including 10 colonized strains and 6 infected strains. Except for the β-lactamase drug resistance gene CTX (16.7% vs. 100.0%, P<0.05), there was no significant difference in the detection rate of other drug resistance genes between CRKP infected strains and colonized strains (P>0.05). The cluster analysis of drug resistance genes of some strains was relatively close. Whole genome sequencing analysis showed that CRKP strains carried a variety of virulence genes, and the detection rates of entB, irp2, iroN, and rmpA genes were 100.0%, 87.5%, 37.5%, and 62.5%, respectively. There was no significant difference in the detection rate of virulence genes between CRKP infected strains and colonized strains (P>0.05). Homology analysis showed that some strains had close homologous relationships, and there was the possibility of cross transmission. Conclusions Some of CRKP infection strains and colonization strains in surgical intensive care unit patients have the risk of cross transmission. In the future, we should strengthen the prevention and control of nosocomial infection to reduce the incidence of infection.