ObjectiveTo retrospectively analyze antibiotic resistance and clinical characteristics of Klebsiella pneumoniae strains for guiding the rational use of antibiotics in the area of the Bai nationality.MethodsThe antibiotic resistance and clinical characteristics of Klebsiella pneumoniae strains were retrospective analyzed, which were isolated from specimens of inpatients in First People’s Hospital of Dali between May 2016 and May 2017.ResultsAmong the 1 342 samples of various kinds of samples, 262 strains of Klebsiella pneumoniae were isolated, with the detection rate of 19.52% (262/1342). Clinical isolated strains were mainly from the new pediatric, intensive care unit, respiratory medicine, pediatrics, and mostly from sputum specimens (78.24%, 205/262). By screening of 22 kinds of antimicrobial agents, all strains had ampicillin resistance (100.00%), while none of these strains had ertapenem resistance. Extended-spectrum β-lactamases (ESBLs) positive strains’ resistance rate was higher than ESBLs negative strains (χ2=261.992, P<0.01). There were 76 drug resistant profiles, most of which were multidrug-resistant bacteria except 116 (44.27%) strains were resistant to ampicillin antibiotics only. And the number of strains in other resistant types ranged from 1 to 16. Only one of 262 strains had amikacin resistance, two of them were resistant to imipenem and meroenan.ConclusionsThere are many multidrug-resistant bacteria in Klebsiella pneumoniae in the population of Bai nationality, and there are no extensively drug resistant bacteria and pandrug-resistant bacteria strains. The strains of carbapene-resistant antibiotics should be worthy of clinical attention.
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 observe the effect of resveratrol on multidrug resistance (MDR) in human retinoblastoma cells treated. Methods RB cells in logarithmic growth phase were divided into experimental group and control group. RB cells in experimental group were cultured with different concentrations of resveratrol (6.25, 12.50, 25.00, 50.00, 100.00 mu;mol/L) for 24 and 48 hours. The proliferation (absorbance value) was assayed using methyl thiazolyl tetrazolium (MTT). RB cells were cultured with 50.00 mu;mol/L resveratrol for 48 hours. The expressions of MDR-1, cyclooxygenase-2 (COX-2)、multidrug resistance-associated protein-1 (MRP-1), glutathione-S-transferases-pi; (GST-pi;) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The RB cells of the control group were cultured with 0.5% dimethyl sulfoxide. Results Compared with the control group, the absorbance value decreased in experimental groups (6.25, 12.50, 25.00, 50.00 mu;mol/L) in a dose dependent manner (F=4.782，P＜0.05). The difference of absorbance value between 50.00 and 100.00 mu;mol/L experimental groups was not significant (F=6.351,P＞0.05). Compared with the control group, the mRNA (t=9.170, 5.758, 4.152, 4.638) and protein (t=3.848, 5.955, 4.541, 3.514) expression levels of MDR-1, MRP1, COX-2, and GST-pi; decreased in the experimental group (P＜0.05). Conclusion Resveratrol can down-regulate the expression of MDR in RB cells.
ObjectiveTo analyze the curative effect and prognosis of drug resistant tuberculosis meningitis (TBM). MethodsRetrospective analysis was carried out on the clinical data of thirty-two cases of drug resistant tuberculous meningitis patients hospitalized from January 2010 to December 2015. And the prognosis of the patients was evaluated by meliorated Rankin Scale (mRS). ResultsThirty-one cases (96.9%) were improved in 32 patients with drug resistant TBM, and 1 case (3.1%) was ineffective. After treatment, one patient had hormone-related glaucoma and osteoporosis, and one patient had drug Cushing syndrome. Twenty-seven patients (84.4%) had an mRS score equal to or less than 2 points. ConclusionDrug resistant TBM is difficult to diagnose in the early stage, and the curative effect is satisfying with active anti-tuberculosis treatment.
Objective To study the efficacy and safety of combined anti-tuberculosis regimen containing bedaquiline in the treatment of multidrug-resistant tuberculosis (MDR-TB). Methods A total of 69 MDR-TB patients treated by joint regimen combined bedaquiline with other anti-tuberculosis drugs between March 2018 and August 2019 in Public Health Clinical Center of Chengdu were taken as the trial group, and 60 MDR-TB patients received treatment without bedaquiline between June 2016 and December 2017 in the same hospital were taken as the control group. The efficacy and safety of the two groups were compared. Results The 69 patients in the trial group included 44 males and 25 females, aged from 21 to 63 years, with an average of (34.6±11.0) years; 58 patients (84.1%) completed the 24-week treatment with bedaquiline, while 11 patients did not complete the treatment, including 3 deaths (4.3%), 1 loss of follow-up (1.4%), 1 withdrawal from the study (1.4%), and 6 discontinuation due to adverse events (8.7%). Among the 54 patients with positive results of tuberculosis on baseline sputum culture, 49 transformed to negative results within 24 weeks of treatment (the negative conversion rate was 90.7%), and the median negative conversion time was 13.0 weeks. The 60 patients in the control group included 45 males and 15 females, aged from 16 to 66 years, with an average of (35.5±13.2) years. Among the 53 patients with positive results of tuberculosis on baseline sputum culture, 30 transformed to negative results within 24 weeks of treatment (the negative conversion rate was 56.6%), and the median negative conversion time was 12.0 weeks. The negative conversion rate of sputum bacteria in the trial group was significantly higher than that in the control group (χ2=16.133, P<0.001). The most common adverse reactions in the trial group were liver function abnormalities (42 cases, 60.9%), prolonged QTc interval (37 cases, 53.6%), electrolyte disturbances (20 cases, 29.0%), and blood system damage (20 cases, 29.0%). In the 37 patients who experienced prolonged QTc interval, there were 8 patients with QTc intervals≥500 ms and 29 patients with QTc intervals ≥450 ms and <500 ms, with a median occurrence time of 16.0 weeks, among whom 25 patients experienced prolonged QTc interval in 4-48 weeks after the withdrawal of bedaquiline. Conclusion The negative conversion rate of tuberculosis sputum culture of patients with MDR-TB treated by bedaquiline combined with other anti- tuberculosis drugs is high, but electrocardiogram should be closely monitored during and after the treatment in order to guard against the potential cardiac toxic effects of bedaquiline.
Objective To observe the regional expression of hypoxia inducible factor-1alpha; (HIF-1alpha;) in retinoblastoma and its relationships with vascular endothelial growth factor (VEGF), Bax and Ki-67. Methods Immunohistochemical study for HIF-1alpha;, VEGF, Bax and Ki-67 was performed in 39 paraffinaceous examples of retinoblastoma. Each pathological section was divided into five regions: the surface region, the central part, the bottom part, the choroidal region and seeding tumors. The expressions, correlations and distributional differences of these factors were all invested both integrally and regionally. Results In the 39 cases of retinoblastoma, 10 cases (25.6%) were negative for HIF-1alpha;; 29 cases (74.4%) were positive for HIF-1alpha;, including 17 cases (43.6%) (+), 12 cases (30.8%) (++). Regionally, HIF-1alpha; was positive in 71.1%, 36.8%, 84.2%, 54.5% and 82.1% of the cases in the surface region, the central part, the bottom part, the choroidal region and seeding tumors, respectively, which was statistically reliable (chi;2=24.55，P＜0.001). The positive rate of VEGF, Bax and Ki-67 was 53.8%, 66.7% and 59.0%, respectively. In different regions, the positive rates of VEGF and Bax were different (chi;2=26.77, 22.79; P＜0.001), but there was no regional distinctions in the expression of Ki-67 (chi;2=0.47, P=0.976). Both the expression of VEGF and Bax had a positive correlation with that of HIF-1alpha;(rs=0.48, 0.39; P=0.002, 0.021), but there was no relationship between the expressions of Ki-67 and that of HIF-1alpha; (rs=0.09, P=0.606). Regionally, the expressions of VEGF, Bax and HIF-1alpha; shared similar distributional features: positive rates were higher in the surface region, bottom part and seeding tumors, and were lower in the central part and choroidal region, which was different from the expression of Ki-67. Conclusion The anoxic zones are more likely to be located in the marginal parts in retinoblastoma, and the expressions of VEGF and Bax had a positive correlation with that of HIF-1alpha; in different regions in retinoblastoma.
Objective To establish a xenograft model of hydroxycamptothecine (HCPT)-resistant human gastric cancer cell line (SGC-7901/HCPT) in nude mice and study its biological characteristics. Methods The SGC-7901 and SGC-7901/ HCPT cells were cultured in vitro. The cell suspension was injected subcutaneously into the nude mice. When the subcutaneous carcinoma was 1.0 cm in diameter, it was cut off and divided into pieces of 0.1-0.2 cm in diameter． Then the small pieces of tumor were re-transplanted subcutaneously into the second generation nude mice until the fourth generation. The morphological feature, ultramicro-structure, and growth characteristics of the fourth generation transplanted tumor were examined. The drug resistance was measured by methyl thiazolyl tetrazolium (MTT) assay. Results The transplanted tumor in nude mice was round or oval, and many blood vessels were on its surface. Under the light microscope, the sizes of SGC-7901 transplanted tumor cells were similar, and sizes of cell nuclei were also similar; Meanwhile, the morphous of SGC-7901/HCPT transplanted tumor cells were irregular and in disorder, and the size of the cell nuclei was different from each other. Under the electron microscope, the mitochondria and endoplasmic reticulum of SGC-7901 transplanted tumor cells were nearly normal and no swelling in cell nuclei; Meanwhile the cell nuclei of SGC-7901/HCPT transplanted tumor cells were lightly swelled, a the mitochondria and endoplasmic reticulum were obviously swelled. By MTT assay, compared with SGC-7901 transplanted tumor cells, the resistance index of SGC-7901/HCPT transplanted tumor cells was 9.02±0.78 in HCPT, and resistance index to Adriamycin， Mitomycin C, 5-fluorouracil, and Etoposide was 1.24±0.09, 1.31±0.17, 0.96±0.12, and 1.07±0.16, respectively. Conclusions A transplanted tumor model of SGC-7901/HCPT in nude mice is established successfully， and showing stable drug resistance to HCPT and no cross-resistance to other chemotherapeutics, which can be used for further experiments.
ObjectiveTo investigate the distribution and drug resistance of pathogens in neonates with lower respiratory tract infection, and provide evidence for clinical rational antibiotic use. MethodsA retrospective analysis on 998 strains isolated from 5 486 sputum samples during January 1, 2009 to December 31, 2012 collected from hospitalized neonates was performed. ResultsOf the 998 isolated strains, the common pathogens were Klebsiella pneumoniae (23.1%), Escherichia coli (E. coli) (21.2%), Staphylococcus aureus (19.4%), and Enterobacter cloacae (8.4%). Klebsiella pneumonia, E. coli and Enterobacter cloacae were generally resistant to penicillin, but enzyme inhibitors could reduce the resistance rate. A large proportion of Klebsiella pneumonia was resistant to the third generation cephalosporins (78.4%), while E. coli and Enterobacter cloacae had a lower resistance rate (46.7% and 46.5%, respectively). There were 7 strains (3.0%) of Klebsiella pneumoniae and 1 (1.2%) strain of Enterobacter cloacae resistant to imipenem. Twenty-three strains (13.6%) of Klebsiella pneumoniae, 1 strain (0.7%) of E.coli and 1 strain (2.5%) of Enterobacter cloacae were resistant to ertapenem. A total of 97.0% of Staphylococcus aureus was resistant to penicillin, but only 11.0% was resistant to oxacillin, and all the isolates were sensitive to vancomycin. ConclusionGram negative bacteria are the common pathogens in the hospitalized neonates in our hospital. Klebsiella pneumonia, E. coli and Staphylococcus aureus are the common pathogens. The common pathogens show a high resistant level to antibiotics. Clinicians should evaluate the potential pathogens of infections based on the results presented in our study, in order to select antibiotics rationally when treating infections.
The issue of bacterial drug resistance has remained unresolved, and in recent years, biomimetic nanostructured surfaces inspired by nature have garnered significant attention due to their bactericidal properties demonstrated through mechanical mechanisms. This article reviewed the main research progress in the field of nanostructured mechanical bactericidal surfaces, including various preparation methods for nanostructured surfaces with mechanical bactericidal properties, as well as the basic mechanisms and related physical models of the interaction between bacteria and nanostructured surfaces. In addition, the application of nanostructured surfaces in biomedicine was introduced. Finally, the article proposed the major challenges faced by mechanical bactericidal research and the future development direction.
ObjectiveTo summarize progression of growth factor receptor (GFR) signaling pathway in endocrineresistant breast cancer. Method Literatures about mechanisms of GFR signaling pathway in the development of endocrineresistant breast cancer were reviewed. ResultsThe crosstalk between GFR and estrogen receptor (ER) signaling pathway had been reported to be involved in the development of endocrine-resistant breast cancer. Interrupting this signaling pathway could overcome endocrine therapy resistance. Many clinical trails had shown that the utilizing endocrine therapy combined with GFR inhibitors could obviously increase the survival rate of patients with breast cancer. ConclusionSeveral agents targeting GFR signaling pathways show a great potential for treatment of patients with breast cancer.