Bacterial biofilms are associated with at least 80% of human bacterial infections. The clinical treatment of biofilm infection is still arduous, and therefore many new treatment options are under study, such as probiotics and their derivatives, quorum sensing inhibitors, antimicrobial peptides, phage therapy, organic acids, light therapy, and plant extracts. However, most of these schemes are not mature, and it is important to develop new research directions of anti-biofilms.
Abstract A new kind of soft tissue expander with exteriorized injection valve was reported. Two types of expanders were designed: one with single cyst, single tube and single chamber, and the other with single cyst, single tube but double chambers, i.e, an additional drainage chamber. The drainage orifice could be controlled by a valve. An animal experiment had been conducted, and the outcome suggested that the new expander could provide rapid expansion of the soft tissue, sufficient drainage of the expanded area. The bacterial culture showed that among the 42 samples obtained from the expanded cyst, only 3 were positive. (2 of bacteria and 1 of fungus), suggesting comparatively low cyst infection.
ObjectiveTo investigate the condensate pollution in the pipeline of severe pneumonia patients undergoing mechanical ventilation.MethodsFrom January 2017 to January 2019, 120 patients with severe pneumonia treated by mechanical ventilation in our hospital were collected continuously. The lower respiratory tract secretions were collected for bacteriological examination. At the same time, the condensed water in the ventilator exhaust pipe was collected for bacteriological examination at 4, 8, 12, 16, 20 and 24 hours after tracheal intubation and mechanical ventilation. The bacterial contamination in the condensed water at different time points was analyzed and separated from the lower respiratory tract. The consistency of bacteria in secretion and drug resistance analysis of bacterial contamination in condensate water were carried out.ResultsOf the 120 patients with severe pneumonia after mechanical ventilation, isolates were cultured in the lower respiratory tract secretions of 102 patients. One strain was cultured in 88 cases, two strains were cultured in 10 cases, and three strains were cultured in 4 cases. The isolates were mainly Gram-negative bacteria (57.5%) and Gram-positive bacteria (42.5%). The most common isolates were Pseudomonas aeruginosa, Staphylococcus aureus and Acinetobacter baumannii. The contamination rate of condensate water was 5.0% at 4 hours, 37.5% at 8 hours, 60.0% at 12 hours, 76.7% at 16 hours, 95.0% at 20 hours, and 100.0% at 24 hours, respectively. The bacterial contamination rate in condensate water at different time points was statistically significant (P=0.000). The pollution rate at 4 hours was significantly lower than that at 8 hours (P=0.000). Gram-negative bacteria accounted for 57.5% and Gram-positive bacteria accounted for 42.5%. The most common isolates were Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. The consistency of bacteria in lower respiratory tract and condensate water was 83.3% in severe pneumonia patients undergoing mechanical ventilation. The overall resistance of Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus was higher, but the resistance to imipenem/cilastatin was lower.ConclusionsThe bacterial contamination in the condensate of patients with severe pneumonia during mechanical ventilation is serious. The pollution rate is low within 4 hours. It is consistent with the bacterial contamination in lower respiratory tract and the bacterial resistance is high.
Objective To analyze the effectiveness and effect on pregnant outcome about living preparation of lactobacillus versus metronidazole in the treatment of bacterial vaginosis in pregnancy. Methods We searched PubMed, The Cochrane Library, VIP, CNKI, Wangfang, CBM, FMJS, and FEBMT to identify randomized controlled trials (RCT) of living preparation of lactobacillus versus metronidazole for bacterial vaginosis in pregnancy. The quality of the included trials was assessed. RevMan 5.0.24 software was used for meta-analysis. Results Eight trials involving 1 687 patients were included. The results of meta-analysis showed: no significant difference was found in the effectiveness between the two groups (RR=1.04, 95%CI 1.00 to 1.08, P=0.08); living preparation of lactobacillus had lower recurrence rate and lower premature delivery rate compared with metronidazole (RR=0.16, 95%CI 0.06 to 0.43, P=0.0004; RR=0.56, 95%CI 0.33 to 0.94, P=0.03); no significant differences were found in premature rupture of membrane, puerperal infection, infant of low-birth weight, infant infection, and infant jaundice between the two groups. Conclusion The effectiveness about living preparation of lactobacillus versus metronidazole for bacterial vaginosis in pregnancy is similar, but living preparation of lactobacillus has lower recurrence rate and lower premature delivery rate, the others of effect on pregnant outcome are similar.
ObjectiveThe changes of intestinal permeability and relationship of intestinal mucosa and bacterial translocation were studied in rat acute necrotizing pancreatitis (ANP) models.MethodsThe ANP models were made by injection of 5% sodium taurocholate 1.0 ml into pancreatic subcapsula.Then wistar rats were divided into four groups,control group (n=20),ANP group(n=22),treatment model group fed with lactose (n=22) and treatment model group fed with MgSO4 and antibiotic (n=22).After 72 hours,the experimental models were sacrificed.Tissues of pancreas,mesenteric lymph node, ascites were collected for microbiological study.The intestinal permeability was observed by lanthanum tracer.The blood samples were obtained from portal vein and ascites in order to assay the amount of amylase in serum.The pathologic lesions were found in the intestinal villus of the model group, including acute necrosis of intestinal mucosa,necrotichaemorrhage as well as enteroparalysis and a mass of haemorrhagic ascites.ResultsBacterial translocation of model group were markedly elevated than that of control (P＜0.05).There were statistically significant differences in bacterial translocation among three model groups （P＜0.05）.The pathologic lesions were found in the intestinal villus of the model group,including acute necrosis of intestinal mucosa,necrotichaemorrhage as well as enteroparalysis and a mass of haemorrhagic ascites.The lanthanum grain in clearance of intestinal cell of model group can be observed by eletron microscope.ConclusionThere is a severe gut barrier damage and injury in the intestinal mucosa,which lead to bacterial translocation from intestine as the source of pancreatic infection.Cleaning out enteric bacteria,improving intestinal movement and feeding with lactose could decrease bacterial translocation to treat and prevent acute necrotizing pancreatitis.
Objective The intercellular adhesion (ica) gene of Staphylococcus epidermidis (SE) is a key factor to bacterial aggregation, to analysis the genotype of iatrogenic SE and to explore the effect of iatrogenic SE ica operon on theformation of bacterial biofilm on the surface of polyvinyl chloride (PVC). Methods Fifty-six cl inical isolates of iatrogenic SEwere selected, and PCR and gene sequencing were used to detect the genes related with bacterial biofilm formation. The genes contained 16S rRNA, autolysin (atlE), fibrinogen binding protein (fbe), and icaADB. The bacteria suspension of 1 × 105 cfu/mL iatrogenic SE was prepared; according to the test results of target genes, the PVC material and the genotype of icaADB+, atlE+, fbe+ strains were co-cultivated as the ica positive group; the PVC material and the genotype of icaADB-, atlE+, fbe+ strains were co-cultivated as the ica negative group. The thickness of biofilm and bacterial community quantity unit area on PVC materials were measured by confocal laser scanning microscope, and the surface structure of biofilm formation was observed by scanning electron microscope (SEM) at 6, 12, 18, 24, and 30 hours. Results The positive rate of 16S rRNA of iatrogenic SE strains was 100% (56/56). The genotype of icaADB+, atlE+, and fbe+ strains accounted for 57.1% (32/56). The genotype of icaADB-, atlE+, and fbe+ strains accounted for 37.5% (21/56). The sequencing results showed that the product sequences of 16S rRNA, atlE, fbe, and icaADB were consistent with those in GenBank. With time, no significant bacterial biofilm formed on the surface of PVC in ica operon negative group. But in ica operon positive group, the number of bacterial community was gradually increased, and the volume of bacterial biofilms was gradually increased on the surface of PVC. At 24 hours, mature bacterial biofilm structure formed, and at 30 hours, the volume of bacterial biofilms was tending towards stabil ity. The thickness of biofilm (F=6 714.395, P=0.000) and the bacterial community quantity unit area on PVC materials (F=435.985, P=0.000) in ica operon positive groupwere significantly higher than those in ica operon negative group. Conclusion Iatrogenic SE can be divided into 2 types ofica operon negative and ica operon positive bacteria. The iatrogenic SE ica operon can strengthen bacterium biofilm formation capabil ity on PVC materials, bacterium community quantity, and thickness of biofilm, it plays an important role in bacterium biofilm formation on PVC materials.
ObjectiveTo investigate biofilm formation on the surface of silica gel by breast surgery clinical specimens of Staphylococcus epidermidis and to analyze the relationship between biofilm formation and icaA, icaD, and accumulation-associated protein (aap) gene. MethodsBetween December 2011 and January 2013, 44 strains of Staphylococcus epidermidis were isolated from the clinical specimens of the female patients who had no symptom of infection. The icaA, icaD, and aap genes were detected by PCR and 4 genotypic groups were divided:icaA+icaD+/aap+ group (group A), icaA+icaD+/aap- group (group B), icaA-icaD-/aap+ group (group C), and icaA-icaD-/aap- group (group D). Biofilms mass was semi-quantified by semi-quantitative adherence assay after 8, 12, 24, 30, and 36 hours of incubation. The thickness of biofilms was measured by confocal laser scanning microscope (CLSM) at 12 and 24 hours after incubation. The ultrastructure of biofilms was observed by scanning electron microscope (SEM) at 24 hours after incubation. ResultsPCR test showed that 13 strains were icaA+icaD+/aap+(group A), 12 strains were icaA+icaD+/aap-(group B), 16 strains were icaA-icaD-/aap+(group C), and 3 strains were icaA-icaD-/aap-(group D). In 29 strains which had bacterial biofilm formation (65.9%), there were 13 strains in group A, 7 strains in group B, 9 strains in group C, and 0 in group D. The result of semi-quantitative adherence assay showed no significant difference in the absorbance (A) values among 4 groups at 8 hours (P>0.05). The A values of groups A, B, and C were significantly higher than that of group D at 12-36 hours, and group A was significantly higher than groups B and C (P<0.05), but there was no significant difference between groups B and C (P>0.05). The results of CLSM showed that the thickness of biofilm in groups A, B, and C was significantly larger than that in group D at 12 and 24 hours after incubation (P<0.05), and the thickness of biofilm in group A was significantly larger than that in groups B and C (P<0.05), but there was no significant difference between groups B and C (P>0.05). The result of SEM showed that the mature biofilm could be observed on the surface of silica gel in groups A, B, and C, and the ultrastructure of biofilms in group A were the most abundant and extensive among 3 groups. The ultrastructure of biofilm in group B was similar to that in group C. No obvious biofilms formed in group D. ConclusionicaA, icaD, and aap genes all play key roles in the process for biofilm formation of Staphylococcus epidermidis. Futhermore, aap gene enhance the ability of biofilm-forming when aap and ica genes coexist, so the biofilm-forming ability of icaA+icaD+/aap+ is strongest.
Objective To investigate the effect of recombinant human growth hormone (rhGH) on intestinal bacteria and endotoxin translocation in experimental obstructive jaundice. MethodsObstructive jaundice rat models were made and divided into three groups: sham operation (SO) group, obstructive jaundice (OJ) group and obstructive with rhGH (OG) group. The number in each group was 20. The mice in rhGH group underwent subcutaneous injection each day of Saizen, with the dose of 0.75 u/kg, while SO group and OJ group received nitric sodium injection. All these maitained for 2 weeks, then the animals were killed and the endotoxin were determined by limulus test, and bacterial cultures of ascites, blood, mesenchymal lymph node, kidney, spleen and liver were made, and the height of villi and the thickness of intestinal walls were examined.ResultsThe value of endotoxin in OJ group was (0.77±0.03) u/ml, higher than that in OG group and SO group, while it was (0.40±0.02) u/ml and (0.33±0.03) u/ml (Plt;0.01). The bacteria translocation rate in OJ group was 58.8%, much higher than that in OG group, which was 10.0% (Plt;0.01). There was no difference between OG group and SO group (Pgt;0.05). Villi height in OJ group was (183.39±11.09) μm, and thickness was (255.62±16.58) μm. While in OG group was (237.52±13.65) μm, and (320.81±14.34) μm (Plt;0.01) respectively.Conclusion rhGH has significant effect on protecting the injuried mucosa barrier in obstructive jaundice, and can decrease endotoxemia and bacteria translocation.
In order to investigate the mechanism of enterogenous infection, sixty SD rats were randomly allocated into four groups∶ group of intestinal obstruction; group of cyclophosphamide+intestinal obstruction; group of cyclophosphamide and group of sham-operation. Each group included 15 rats. Twenty four hours after obstruction of the terminal ileum, the bacteria in blood of portal vein, blood of heart, peritoneal fluid, mesenteric lymph node (MLN) and content of gut were determined quantitatively, the concentration of endotoxin in portal system were measured. The results showed that early (24 hours) intestinal obstruction led to endotoxemia in portal vein, overgrowth of enteric G－bacili and bacterial translocation into the MLN. The immunosuppressive agent cyclophosphamide not only increased the rate of bacterial translocation into MLN and the number of living bacteria in MLN, but also promoted bacteria to spread into the systemic circulation. The authors conclude that under immunosuppression the bacterial translocation from gut by way of lymphatic channel plays an important role in enterogenous infection.
ObjectiveTo study the relationship between mutation of the p53 gene, p21 gene and bacteria Lform in gallbladder carcinoma. MethodsForty cases of gallbladder carcinoma and 40 cases of chronic cholecystitis were studied by using Gram staining and immunohistochemistry (SP method) to detect the positive rate of Lforms antigen, p21 and p53 protein overpression. And the relationship between the expression of p21 and p53 in Lform infection positive group and that in Lform infection negative group was discussed. ResultsThere was no statistical difference between the Lform positive rate in patients with gallbladder carcinoma with Gram staining and immunohistochemistry (Pgt;0.05). The positive expression rate of p21 and p53 in gallbladder carcinoma was 62.5%(25/40) and 65.0%(26/40) respectively. The expression values of p21 and p53 in chronic cholecystitis was 2.5%(1/40) and 5.0%(2/40) respectively, which was significantly different from that of gallbladder carcinoma (P＜0.05). The expression of p21 and p53 was significantly higher in Lform infection positive group than in that with Lform infection negative group (P＜0.05). ConclusionBacteria Lform may be one of the direct factor leading to mutation of p53 and p21 during gallbladder oncogenesis.