ObjectiveTo study the influence of myxobacteria metabolites NX52 and NX83 on the proliferation of colorectal carcinoma cells and investigate its probable mechanism.
MethodsThe human colorectal carcinoma cell lines HT-29, SW480, and SW1463 were respectively treated with the two metabolites (NX52 and NX83) at different concentrations (0.1 mg/mL, 1.0 mg/mL, and 10.0 mg/mL), the cells of negative control were treated without metabolite. The proliferation inhibition was examined by methyl tthiazolyl tetrazolium assay. The cell morphology character was compared by inverted microscope, and the apoptosis of cell was analyzed by flow cytometry.
ResultsTwo kinds of metabolites NX52 and NX83 had time-dose inhibitory effects on proliferation of human colorectal carcinoma cells HT-29, SW480, and SW1463 (P < 0.05). The metabolite NX83 had more obvious proliferation inhibition in the colorectal carcinoma cells as compared with the metabolite NX52 (P < 0.05). After 48 h, the apoptosis rate of the metabolite NX83 for SW1463 cell was observably increased as compared with the negative control group (P < 0.01).
ConclusionsThe two kinds of metabolites NX52 and NX83 from myxobacteria could kill colorectal carcinoma cells in vitro. The possible mechanism might be induced by apoptosis of tumor cells.
Objective To investigate the joint effects of selective digestive decontamination (SDD) and glutamine (Gln) on preventing intestinal bacterial translocation of orthotopic piggyback liver transplantation and to observe the incidence of postoperative pneumonia in rabbit. Methods Thirty rabbits received orthotopic piggyback liver transplantation and were randomly divided into three groups (SDD group, SDD+Gln group and control group). Mixed emulsion of tobramycin, polymyxin E and nystatin were given to the rabbits in SDD group. Same dosage of the above components plus Gln were given to the rabbits in SDD+Gln group. Samples of portal vein blood, ileum tissue and lung tissue were obtained in each group at different phases during and after operation, the pathological changes of ileum tissue, the bacterial translocation in blood of portal vein and the incidence of postoperative pneumonia were detected. Results The mixing section area of intestinal blood capillaries in SDD+Gln group was smaller compared with control group (P＜0.05， P＜0.01) and SDD group (P＜0.05) while the portal vein was obstructed for 15, 30 and 45 min, and after the operation, respectively. The length of ileum villus in SDD+Gln group was longer than that in control group (P＜0.05) and in SDD group (P＜0.05) before the portal vein was obstructed, but the length of ileum villus in control group gradually became longer and eventually exceeded that in SDD+Gln group at the time of 45 min after the portal vein was obstructed (P＜0.05). After the operation, the length of ileum villus in SDD+Gln group was significantly longer than that in SDD group (P＜0.05) and control group (P＜0.01). At the time of 45 min after the obstruction of portal vein and 30 hours after operation, the positive rate of cultured bacterial in the blood of portal vein in SDD+Gln group was significantly lower than that in control group (P＜0.05, P＜0.01). The incidence of postoperative pneumonia in SDD+Gln group and SDD group were significantly lower than that in control group (P＜0.05,P＜0.01). Conclusion Gln could nourish intestinal epithelium of mucous membrane.When combined with SDD, it could decreased the incidence of intestinal bacterial translocation occurred during the obstruction of portal vein and after operation, so as to decrease the incidence of postoperative pneumonia.
ObjectivesTo systematically review the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates.MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data, VIP and CBM databases were electronically searched to collect cohort or case-control studies on the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates from inception to May 2020. Two reviewers independently screened literature, extracted data, and assessed risk of bias of included studies, and meta-analysis was performed by RevMan5.3 software.ResultsA total of 9 case-control studies involving 759 patients were included. The results of meta-analysis showed that, maternal factors like placental abruption (OR=6.25, 95%CI 1.47 to 26.61, P=0.01), premature rupture of fetal membranes of parturient (OR=5.62, 95%CI 2.63 to 12.00, P<0.000 01), pregnancy-induced hypertension (OR=2.04, 95%CI 1.49 to 2.80, P<0.000 01), carbapenem antibiotics used in mothers (OR=1.77, 95%CI 1.10 to 2.81, P=0.017), neonatal factors like premature delivery (OR=1.96, 95%CI 1.06 to 3.61, P=0.03), mechanical ventilation (OR=2.14, 95%CI 1.01 to 4.55, P=0.05), surgical procedure (OR=14.17, 95%CI 2.46 to 81.70, P=0.003), umbilical vein catheter (OR=1.93, 95%CI 1.20 to 3.11, P=0.007), peripherally inserted central catheter (OR=4.30, 95%CI 1.86 to 9.93, P=0.000 6), nasogastric feeding (OR=4.37, 95%CI 1.44 to 13.29, P=0.009), use of carbapenems (OR=3.04, 95%CI 1.91 to 4.84, P<0.000 01), and admission to NICU (OR=2.78, 95%CI 1.79 to 4.33, P<0.000 01) were the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates. Breastfeeding (OR=0.30, 95%CI 0.13 to 0.70, P=0.005) was the protective factor of carbapenem-resistant enterobacteriaceae colonization or infection in neonates.ConclusionsThe current evidence shows that maternal factors like placental abruption, premature rupture of fetal membranes, pregnancy-induced hypertension, carbapenem antibiotics used in mothers, and neonatal factors like premature delivery, mechanical ventilation, surgical procedure, umbilical vein catheter, peripherally inserted central catheter, nasogastric feeding, use of carbapenems, and admission to NICU are the risk factors of carbapenem-resistant enterobacteriaceae colonization or infection in neonates; while breastfeeding is the protective factor of carbapenem-resistant enterobacteriaceae colonization or infection in neonates. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the conclusions.
ObjectiveTo observe the impacts of initial therapy on clinical outcome of patients with community-acquired thoracic infection by retrospective analysis.
MethodsClinical data of acute community-acquired thoracic infection patients who met the British Thoracic Society diagnostic criteria were collected. The patients were divided into two groups according to whether adequate initial antibiotic therapy and pleural effusion drainage were performed, namely an adequate group (31 patients) and an inadequate group (17 patients). Clinical manifestations, inflammatory markers, hospital stay and hospital costs were analyzed between the two groups.
ResultsFor age, gender, infection sites, and coincident diseases, there were no significant differences between the two groups. Compared with the inadequate group, temperature of the adequate group was significantly decreased, especially on hospital day 5, 6, 7[(37.4±0.1)℃ vs. (38.3±0.2)℃, P < 0.001; (37.4±0.1)℃ vs. (37.9±0.1)℃, P < 0.05; (37.4±0.1)℃ vs. (38.1±0.2)℃, P < 0.01]. The level of serum C-reactive protein (CRP) in first week was also significantly reduced in the adequate group[(123.1±13.8) mg/L vs. (182.7±25.3) mg/L, P < 0.05]. However, there were no differences in white cell counts, percentage of neutrophils, or erythrocyte sedimentation rate between the two groups in six-week follow-up. The adequate group had shorter hospital stay[(25±4) days vs. (34±4) days, P < 0.05] and lower hospital costs[(28 367±3 328) yuan vs. (43 334±7 134) yuan, P < 0.05] compared with the inadequate group.
ConclusionsThe initial therapy with appropriate antibiotics and effective thoracic drainage can significantly decrease the temperature and CRP of patients with thoracic infection, as well as the cost of hospitalization and the length of stay. Our study reveals that the temperature which is lower than 37.5℃ on the 5th day of therapy and the CRP in the first follow-up week are sensitive predictors of initial treatment effect, which may be helpful to guide the following therapeutic strategies.
Objective To clarify the bacterial spectrum and drug resistance of different biliary diseases through bile culture results. Methods Patients who underwent surgical treatment and retained bile for cultivation at the Chinese PLA General Hospital between January 2015 and December 2016 were retrospectively collected. Clinical data such as bile bacterial culture and antibiotic sensitivity results, surgical reasons, and perioperative complications were recorded. Results A total of 272 patients were included, including 142 males and 130 females, aged (53.4 ± 14.1) years old. Intrahepatic and extrahepatic bile duct stones were the most common surgical cause, accounting for 32.4%. The positive rate of bile culture in benign diseases was 78.7%, which was higher than that in malignant diseases (48.5%). The infection related complications (30.0% vs. 6.7%), bile leakage rate (20.8% vs. 6.7%), and poor wound healing rate (24.0% vs. 0.0%) in the bile culture positive group were higher than those in the bile bacteria culture negative group (P<0.05). Among 183 patients with positive bile bacterial culture, a total of 294 strains of pathogenic bacteria were detected. There were 96 patients with single bacterial infection, 66 patients with two bacterial infections simultaneously, 18 patients with three bacterial infections, and 3 patients with four or more bacterial infections. Escherichia coli was the most common bacterium, accounting for 17.0%. There were differences in the positive rate of bile culture among patients with different etiologies (P<0.05). There were significant differences in the sensitivity rate of Enterococcus faecalis and Enterococcus faecalis for many antibacterial drugs. Conclusions There are differences in the positive rate of bacterial culture in the biliary tract of patients with different etiologies, and there is a possibility of mixed infection. It is necessary to select appropriate antibiotics for empirical treatment based on different etiologies. The use of antibiotics should be changed in a timely manner based on the results of bile culture.
ObjectiveTo review the related studies on the application of nanomaterials in the treatment of osteomyelitis, and to provide new ideas for the research and clinical treatment of osteomyelitis.MethodsThe literature about the treatment of osteomyelitis with nanomaterials at home and abroad in recent years was reviewed and analyzed.ResultsAt present, surgical treatment and antibiotic application are the main treatment options for osteomyelitis. But there are many defects such as antibiotic resistance, residual bone defect, and low effective concentration of local drugs. The application of nanomaterials can make up for the above defects. In recent years, nanomaterials play an important role in the treatment of osteomyelitis by filling bone defects, establishing local drug delivery system, and self-antibacterial properties.ConclusionIt will provide a new idea and an important research direction for the treatment of osteomyelitis to fully study the related characteristics of nanomaterials and select beneficial materials to make drug delivery system or substitute drugs.
Objective To prepare silver-containing hydroxyapatite coating (hydroxyapatite/Ag, HA/Ag) and investigate its antibacterial property and biocompatibil ity in vitro. Methods Vacuum plasma spraying technique was adopted to prepare HA/Ag coating on titanium alloy substrate (3% Ag). After incubating the HA/Ag and the HA coating under staphylococcus aureus and pseudomonas aeruginosa suspensions of 2% tryptic soy broth (TBS) medium for 2, 4 and 7 days, respectively, the biofilm on the coatings was examined by confocal laser scanning microscope, and the bacterial density and viable bacterial percentage of bacterial biofilm were calculated. Meanwhile, the micro-morphology of bacterial biofilm was observed by SEM, the cytotoxicity was detected via MTT and the biocompatibil ity of biofilm was evaluated by acute aemolysis test. Results Compared with HA coating, the bacterial biofilm’s thickness on the surface of HA/Ag coating witnessed no significant difference at 2 days after culture (Pgt; 0.05), but decreased obviously at 4 and 7 days after culture (P lt; 0.01). The bacterial density of the biofilm increased with time, but there was no significant difference between two coatings (P gt; 0.05) at 2, 4 and 7 days after culture. The viable bacterial percentage of the biofilms on the surface of HA/Ag coating decreased obviously compared with that of HA coating at 2, 4 and 7 days after cultureP lt; 0.01). The MTT notified the cytotoxic grade of both coatings was zero. The acute haemolysis assay showed that the hemolytic rate of HA/Ag and HA coating was 0.19% and 0.12%, respectively. Conclusion With good biocompatibil ity, significant antibacterial property against staphylococcus aureus and pseudomonas aeruginosa, no obvious cytotoxicity and no erythrocyte destruction, the vacuum plasma sprayed HA/Ag coating is a promising candidate for the surface of orthopedic metal implants to improve their osseointegration and antibacterial property.
PURPOSE: To investigate the treatment of severe bacterial endophthalmitis. METHODS:The curative effects of vitrectomy after intravitreal antibiotics and steroids (IVAS)for the treatment of 23 patients with bacterial endophthalmitis
(group I)and vitrectomy and IVA at the same time for the treatment of 28 patients with bacterial endopbthalmitis (group I)were analyzed retrospectively. RESULTS: The rate of curative effects of two groups were similar,while the marked curative effects in group I (47.8% )was significantly higher than that of the group I (17.9%). The average period of eliminating infiamation of group I was longer than that of group I , and the incidence of postoperative retinal detachment of group Ⅱ was 3 times more than that of group I . CONCLUSION :It was indicated that vitrectomy after IVAS may increase the security of vitrectomy and the curative effects of severe bacterial ndophthalmitis.
Objective A comparative study of in-hospital mortality and risk factors of ventilator-associated pneumonia (VAP) caused by carbapenem-resistant gram-negative bacteria (CRGNB) and non-carbapenem-resistant gram-negative bacteria (nCRGNB) in China was conducted to investigate whether there is a higher in-hospital mortality of VAP caused by CRGNB and its unique associated risk factors. Methods Relevant literatures published at home and abroad in PubMed, EMBASE, Cochrane library, Web of Science, CNKI and Wanfang databases were retrieved from the date of establishment to June 1, 2021, and the quality of the included literatures was evaluated using Newcastle-Ottawa scale. Meta-analysis of literatures meeting the criteria was performed using RevMan 5.3 software. Results A total of 5 literatures were included, all of which were case-control studies with a total of 574 cases, including 302 cases in the CRGNB group and 272 cases in the nCRGNB group. The results showed that the in-patient mortality of VAP caused by CRGNB infection was significantly increased compared with that of VAP caused by nCRGNB infection (OR=2.51, 95%CI 1.71 - 3.67, P<0.00001). Risk factor analysis of CRGNB infection showed that statistically significant risk factors included mechanical ventilation duration ≥7 days (OR=2.66, 95%CI 1.23 - 5.75, P=0.01), secondary intubation (OR=4.48, 95%CI 2.61 - 7.69], P<0.00001), combined with antibiotics (OR=2.83, 95%CI 1.76 - 4.54, P<0.0001), using carbapenem antibiotics (OR=2.78, 95%CI 1.76 - 4.40, P<0.0001). In addition, two studies showed that tigecycline was sensitive to CRGNB in vitro. Conclusions Compared with nCRGNB-induced VAP, CRGNB infection significantly increases the in-hospital mortality of VAP patients in China, indicating that the in-hospital mortality of CRGNB infection is related to drug resistance, and had little relationship with region and drug resistance mechanism. Among them, mechanical ventilation duration ≥7 days, secondary intubation, combined use of antibiotics and carbapenem antibiotics are risk factors for CRGNB infection in VAP patients. Tigecycline is sensitive to most CRGNB strains in China and is an important choice for the treatment of CRGNB in China.
ObjectiveTo investigate the effect of accessory gene regulator C (agr C) specific binding peptides (named N1) on the biofilm formation of Staphylococcus epidermidis on the surface of polyvinyl chloride (PVC) materials in vitro.MethodsFirstly, the two strains (ATCC35984, ATCC12228) were cultured with N1 at concentrations of 100, 200, 400, 800, and 1 600 μg/mL, respectively. The control group was cultured with agrC specific binding unrelated peptides (named N0) at the same concentrations and the absorbance (A) value was measured after 24 hours to determine the optimal bacteriostatic concentration of N1. The two strains were cultured with N1 and N0 of the optimal concentration, respectively. The A values were measured at 6, 12, 18, 24, 30, and 48 hours to observe the effect of N1 on the biofilm formation ability of Staphylococcus epidermidis. On this basis, the surface structure of the biofilm on the surface of PVC material was observed by scanning electron microscopy after 6, 12, 18, 24, and 30 hours of incubation with PVC material sheet. The thickness of the biofilm was observed by laser confocal microscopy after 6, 12, 18, and 24 hours of incubation with ATCC35984 strain.ResultsThe optimal bacteriostatic concentration of N1 was 800 μg/mL. ATCC 12228 strain did not form obvious biofilm after being cultured with N1 and N0. When ATCC35984 strain was cultured with N1 and N0 for 12 hours, the difference in biofilm formation ability between groups N1 and N0 was statistically significant (P<0.05), but there was no significant difference at 6, 18, 24, 30, and 48 hours (P>0.05). Scanning electron microscopy examination showed that mature biofilm structure was observed in ATCC35984 strain and was not observed in ATCC12228 strain. Laser confocal microscopy observation showed that the number of bacteria in the group N1 was significantly lower than that in the group N0 at 12 hours, and the most of bacteria were dead bacteria. There was no significant difference in the number of bacteria at 6, 18, and 24 hours, and the most of them were live bacteria. The biofilm thickness of group N1 was significantly lower than that of group N0 at 12 and 18 hours (P<0.05).ConclusionThe intensity of N1 inhibiting the formation of Staphylococcus epidermidis biofilm is dose-dependent. During the aggregation period, N1 can inhibit the biofilm formation by hindering the bacterial growth and aggregation. The inhibition effect on mature biofilm is not obvious.
