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.
In order to inquire into the relation between bacterial L-forms and chronic appendictis,appendices removed from 10 patients with appendicitis were cultured with improved kagans’s solid medium and nutrient medium containing blood respectively.Bacterial forms with bacterial L-form transforms to L-forms and 1 strain of bacillus aerogen with its L-form.The result shows that bacterial form transforms to L-form,then to bacterial form may be related with appendicitis attack,alleviation and attack again.
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.
Objective To explore the bacterial translocation of mesenteric lymph nodes （MLNs） of the ileum and the spectrum of bacteria in patients with small bowel obstruction.Methods Total 84 patients were divided into study group （with small bowel obstruction） and control group （without small bowel obstruction）. MLNs were obtained under sterile conditions intraoperatively， and which were processed for culture of aerobic and anaerobic organisms. The rate of bacterial translocation and postoperative infection were compared between two groups and the species of bacterial translocation was identified. Results The bacterial translocation rate in the study group was higher than that in the control group 〔57.1% （24/42） versus 16.7% （7/42），χ2=14.775， P＜0.01〕. Escherichia coil was the most commonly bacteria （20）. Emergency surgery and age over 70 years were associated with bacterial translocation （P＜0.05）. Postoperative infection complications rate in the bacterial translocation patients was higher than that in the patients without bacterial translocation 〔29.0% （9/31） versus 3.8% （2/53），χ2=10.965，P＜0.05〕. Conclusions Bacterial translocation to MLNs occurres more frequently in patients with small bowel obstruction，non-elective surgery， and elderly.
ObjectiveTo establish a methodology for alveolar macrophages (AMs) phagocytosis of AlexaFluor 488 (AF488) labeled bacteria by flow cytometry.MethodsStaphylococcus aureus and Streptococcus pneumoniae were labeled with different concentrations of AF488. A flow cytometric assay was used to quantify in vivo bacterial uptake by AMs. AMs and different ratio of fluorescent-labeled bacteria were incubated at 37 ℃ for 2 hours, 4 hours, 6 hours and 8 hours, respectively. AMs were washed with DPBS and extracellular fluorescence was quenched with 1% (w/v) trypan blue. Trypan blue was aspirated and phagocytosis of fluorescent-labeled bacteria by AMs was measured using a flow cytometry. Confocal microscopy was performed to ensure that bacterial in positive AM had been internalized rather than bound to the cell surface.ResultsWhen the concentration of AF488 was more than 50 μg/mL, the labeling rates of Staphylococcus aureus and Streptococcus pneumoniae were higher than 92% (P<0.05), and has quickly reached the upper limit. With the prolongation of incubation time, the phagocytic rate of AMs increased from 20.4% at 2 hours to 76.5% at 8 hours. With the increase in the number of bacteria, the phagocytic rate of AMs increased from 7.7% by ratio of 1∶10 to 85.1% by ratio of 1∶300.ConclusionDetection of AMs phagocytosis of AF488 labeled bacteria by flow cytometry is an effective method, but the dye concentration, incubation time and the proportion of bacteria will influence the results.
Objective To explore the pathogens and clinical features of immunocompromised hosts with septicaemia.Methods The data including underlying diseases, peripheral blood granulocyte count, temperature at blood sampling, management and prognosis)of 160 immunocompromised hosts with septicaemia were analyzed retrospectively．Results 8 patients had twice septicaemia in hospital stay and 3 patients had plural pathogenic septicaemia.171 strains of microorganisms were isolated from blood cultured of 160 septic immuno- compromised hosts in which 156 strains (91.2%) were bacteria, 37 strains(21.6%) were gram positive cocci, 6 strains(3.5%) were gram positive bacilli, 113 strains (66.1%) were gram negative bacilli and 15 strains (8.8%) were fungi. Staphylococcus spp (17 strains) and Streptococcus spp (14 strains) were the predominant pathogens among gram positive cocci and Corynebacteria (5 strains ) were the main pathogen in gram positive bacilli while Escherichia coli (60 strains), Klebsiella pneumoniae (20 strains) and Pseudomonas aeruginosa (15 strains) were the most common bacteria in gram negative bacilli. There were 12 strains of Staphylococcus aureus among the 17 strains of Staphylococcus spp, all of them were methicillin sensitive (MSSA). 17 strains of Escherichia coli, 2 strains of Klebsiella pneumoniae and 1 strain of Klebsiella oxytoca produced ESBLs. Candida was the only pathogens of fungemia in this study in which 4 strains of Candida albicans and 11 strains of non-albicans Candida were detected. There were 120 patients(75%) with granulocytopeniain which 103 patients were agranulocytosis. 70% of the 160 paitents had hyperpyrexia. All patients received broad spectrum antibiotics therapy in the study while 58.8% received antifungal drugs at the same time. 20 patients died of septicaemia and 19 patients gave up therapy because of their conditions deteriorated.The overall improvement rate were 75.6%. Conclusions Bacteria are the main pathogens in septicaemia of immunocom- promised host and fungemia is increasing in recent years.Agranulocytosis is a risk factor of septicaemia in immunocompromised hosts. Hyperpyrexia is one of characteristic signs of these patients.
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 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 evaluate the rapid diagnosis of bacterial and (or) fungal endophthalmitis by multiplex polymerase chain reaction (MPCR). Methods MPCR was performed to detect the DNA segment of bacteria and (or) fungi from standard strains and 41 samples of intraocular fluid or vitreous from 38 patients (3 with double eyes and 35 with single), and the results were compared with the cultured bacteria and fungi. Results Five hours after detected by MPCR, bacteria and (or) fungi in 34 out of 41 samples (82.9%) from patients were detected，in cluding bacteria in 26，fungi in 6，and both bacteria and fungi in 2. The positive rate of MPCR was obviously higher than the cultured ones（χ2＝9.60, P＜0.05）. Conclusion With the advantages of rapidity, sensibility, and specificity, MPCR can make for the rapid and definitive diagnosis of bacterial and (or) fungal endophthalmitis. (Chin J Ocul Fundus Dis，2004，20：81-83)
Objective To investigate the pathogen distribution and drug resistance in ICU patients, provide reference for prevention of severe infection and empirical antibacterial treatment. Methods The patients admitted in ICU between January 2013 and December 2014 were retrospectively analyzed. The pathogenic data were collected including bacterial and fungal culture results, the flora distribution and drug resistance of pathogenic bacteria. Results A total of 2088 non-repeated strains were isolated, including 1403 (67.2%) strains of Gram-positive bacteria, 496 (23.8%) strains of Gram-negative bacteria, and 189 (9.0%) strains of fungus. There were 1324 (63.42%) strains isolated from sputum or other respiratory specimens, 487 (23.33%) strains from blood specimens, 277 (13.27%) strains from other specimens. The bacteria included Acinetobacter baumannii (17.2%), Klebsiella pneumoniae (14.8%), Pseudomonas aeruginosa (9.9%), C. albicans (6.3%), E. coli (5.6%), E. cloacae (5.4%), Epidermis staphylococcus (5.0%) and Staphylococcus aureus (4.7%). There were 15 strains of penicillium carbon resistant enterobacteriaceae bacteria (CRE) accounting for 2.3%, including 5 strains of Pneumonia klebsiella, 4 strains of E. cloacae. In 117 strains of E. coli, drug-resistant strains accounted for 86.4% including 85.5% of multiple drug-resistant strains (MDR) and 0.9% of extremely-drug resistant (XDR) strains. In 359 strains of Acinetobacter baumannii, drug-resistant strains accounted for 75.2% including 72.1% of XDR strains and 3.1% of MDR strains. MDR strains accounted for 10.6% in Pseudomonas aeruginosa. Detection rate of methicillin resistant Staphylococcus aureus (MRSA) and methicillin resistant coagulase-negative Staphylococci (MRCNS) was 49.0% and 95.5%, respectively. There were 4 strains of vancomycin resistant Enterococcus faecalis. There were 131 (69.3%) strains of C. albicans, 23 (12.2%) strains of smooth candida. C. albicans was sensitive to amphotericin and 5-fluorine cytosine, and the resistance rate was less than 1% to other antifungle agents. The resistance rate of smooth ball candida was higher than C. albicans and nearly smooth candida, but still less than 15%. Conclusions The predominant pathogens in ICU was gram-negative bacteria. The top eight pathogenic bacteria were Acinetobacter baumanni, Klebsiella pneumoniae, Pseudomonas aeruginosa, C. albicans, E. coli, E. cloacae, Epidermis staphylococcus and S. aureus. Sputum and blood are common specimens. CRE accounts for 2.3%. Drug-resistant strains are most common in E. coli mainly by MDR, followed by Acinetobacter baumannii mainly by XDR, and least in Pseudomonas aeruginosa. C. albicans is the most common fungus with low drug resitance.