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.
Objective To overview the effect of bacterial biofilms (BBF) on the formation of chronic osteomyel itis and the treatment measure. Methods The original articles in recent years about the relationship between BBF and chronic osteomyel itis were reviewed. Results The diagnosis and treatment of chronic osteomyel itis was very difficult, besides hyperplasia oflocal scar, poor blood supply, drug-resistant, forming of BBF also was an important reason. BBF formed on the surface of necrosis soft tissue and dead bone. Due to the protection of BBF, the bacterium were far more resistant to antimicrobial agents, which caused the recurrence of chronic osteomyel itis. The forming of BBF included three processes which were adhesion, development and maturity. As the major pathogens of chronic osteomyel itis, staphylococcus had its own characteristic. Designing therapeutic programmes according to these characteristics had become the trend of anti-infection treatment of BBF. Conclusion Although there are lots of studies on anti-biofilm due to the key factors during the forming of BBF, the most effective way of anti-biofilm is still debridement.
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.
ObjectivesTo identify the clinical characteristics and prognosis for CRKP (Carbapenem-resistant Klebsiella pneumonia, CRKP) infection among ICU patients in the Second Affiliated Hospital of Anhui Medical University. MethodsWe conducted a retrospectively analysis in which 19 patients infected by CRKP with another 21 CSKP (Carbapenem-sensitive Klebsiella pneumoniae, CSKP) infected patients from January 2017 to April 2018. Risk factors for CRKP infection were assessed. ResultsThe lower respiratory tract is the most common site of CRKP infection in our department. CRKP infection was associated with several clinical symptoms, particularly a higher incidence of sepsis shock (χ2=8.338, P=0.004), more application of the combined medicine (χ2=26.3, P<0.001), prolonged hospital stays (χ2=–2.217, P=0.027) and more expenses on antibiotics (χ2=12.855, P=0.005), and the declined survival rates in 14 days (χ2=4.269, P=0.039) and 21 days (χ2 =5.647, P=0.017). The resistance rate of CRKP strains was high, however no resistance to tegafycline was found. The risk factors of CRKP infection included three generations of cephalosporin and/or hydrocarbonase antibiotics exposure (χ2 =6.388, P=0.041), exposure time of three generations of cephalosporin (U=–2.187, P=0.029), exposure time of hydrocarbonase antibiotics (U=–2.103, P=0.035), tracheal intubation (χ2=6.352, P=0.012), tracheotomy (χ2 =4.821, P=0.028), SOFA score (t=4.505, P<0.001) and Charlson comorbidity index (t=3.041, P=0.004). The SOFA score was the only factor independently associated with CRKP bacteremia (P=0.02). ConclusionsCRKP infections in ICU directly affect the course of disease, survival time and treatment expenses of patients. Therefore, monitoring bacterial resistance, rational use of antibiotics, and protection of the immune function are of great significance for prevention and treatment of CRKP infection.
Objective To evaluate the effect of hepatocyte growth factor(HGF) on intestinal permeability and bacterial translocation after small bowel transplantation in rats. Methods Twenty Wistar rats were as recptors and twenty SD rats as donors. After heterotopic intestinal grafting, cyclosporine A was administered at 6mg/kg·day intramuscularly for inhibiting rejection. The SD rats were divided into 2 groups(n=10). HGF was administered at 150 μg/kg·day (HGF group) and normal saline was administered at 150 μg/kg·day (controlgroup). Intestinal permeability and bacterial translocation to the mesenteric lymph nodes and portal vein were assessed at the 8th postoperative day. Results The lactulose and lactulose/ mannitol of control group (0.0931%±0.008 5% and 0.132± 0.021) were higher than those of normal reference value (0.015 0%±0.002 0% and 0.020±0.005)（Plt;0.05）. The lactulose and lactulose/ mannitol of HGF group (0.039 6%±0.009 0% and 0.056±0.013) were also higher than those of normal reference value（Plt;0.05）.The bacterial culture positive proportion of lymphaden in HGF group and control group were 10% and 60%, showing statistically significant difference（Plt;0.05）. The bacterial culture positive proportion of portal vein in HGF group and control group were 10% and 20% respectively（P＞0.05）. Conclusion HGF can decrease intestinal permeability and bacterial translocation from the lumen of the graft to the mesenteric lymph nodes,thus improve gut barrier function, may be of help to reduce the incidence of septic complications after intestinal grafting.
Objective To determine the effectiveness of percutaneous catheter drainage (PCD) and to compare PCD with percutaneous needle aspiration (PNA) in the management of bacterial liver abscess. Methods The medical records of 206 patients with bacterial liver abscess admitted to this hospital between January 1989 and December 2009 were analyzed retrospectively. The outcomes of 96 patients receiving percutaneous treatment including PCD (PCD group, n=56) and PNA (PNA group, n=40) were compared, including the length of hospital stay, rates of procedure-related complications, treatment success, and death. Results There was no statistical difference in patients’ demographics or abscess characteristics between two groups (Pgt;0.05). The morbidity, mortality, and length of hospital stay in the PCD group and the PNA group were 1.79% vs 2.50%， 1.79% vs 2.50%， and (19.2±13.1) d vs (20.2±12.9) d, respectively, and the P values were 1.000, 1.000, and 0.887, respectively. There was statistically significant difference in successful rate between two groups （96.43% vs 75.00%， P=0.002）, but all simple abscesses with diameter of 5 cm or less were successfully managed in both PNA group and PCD group （13/13 vs 16/17， P=1.000）. Conclusions PCD is more effective than PNA in the management of bacterial liver abscess. PNA can be used as a valid alternative for simple abscesses with 5 cm in diameter or smaller.
Objective To investigate antimicrobial resistance profiles of carbapenem-resistant Enterobacter spp. (CREn) and the bactericidal effects of aztreonam combined with avibactam. Methods The CREn strains isolated from the West China Hospital of Sichuan University between 2016 and 2021 were identified by gyrB gene amplification and subsequent sequencing. The drug sensitivity results, sample types and distribution of relevant patient departments of these strains were summarized. Colistin-resistant and -intermediate strains were selected to carry out the bactericidal test of colistin and aztreonam combined with avibactam. Results A total of 110 clinical strains of CREn were included. The most common strain was Enterobacter xiangfangensis (91 strains), the highest proportion was in the intensive care unit (27.27%), and the proportion of respiratory tract samples was more than 40%. The antimicrobial sensitivity results showed that CREns were all resistant to carbapenems, the resistance rate to colistin was 23.64%, and the resistance rate to aztreonam combined with avibactam was 0. Among other antimicrobial agents, the antimicrobial resistance rate of amikacin and tigecycline were less than 10%. The time-kill curve showed that for colistin-intermediate strains, colistin could achieve bactericidal effect in a shorter time than aztreonam combined with avibactam. However, whether the strain was resistant to colistin or not, the bactericidal rate of 2 μg/mL aztreonam combined with avibactam in 24 hours could exceed 99%. Conclusion CREn is resistant to most commonly used clinical antibacterial drugs, but remains sensitive to aztreonam combined with avibactam, and aztreonam combined with avibactam has bactericidal effect on it.
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.