Peptidoglycan is an important component of bacterial cell wall, which plays an important role in maintaining the integrity of bacterial cell structure, stimulating immune response, and anti-infection. Peptidoglycan recycling is an indispensable process for bacterial cell growth and reproduction. In recent years, it has been reported that the peptidoglycan recycling is closely related to the occurrence and development of bacterial resistance, especially with the antibacterial activity of β-lactam antibiotics. In this paper, the relationship between peptidoglycan recycling and resistance is described by combining relevant reports and taking Mycobacterium tuberculosis and Pseudomonas aeruginosa as examples, so as to promote the understanding of bacterial resistance mechanisms and provide potential targets for the development of new antimicrobial drugs.
ObjectiveTo systematically review the intervention efficacy of resistance exercise on prediabetes and type 2 diabetes. MethodsPubMed, The Cochrane Library, EMbase, Web of Science, EBSCO, VIP, WanFang Data and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) of resistance exercise applied to pre-diabetic and type 2 diabetic population from 2010 to April, 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed using Revman 5.1 and Stata 12.0 software. ResultsA total of 26 RCTs involving 2 078 patients were included. The results of meta-analysis showed that resistance exercise could improve fasting blood glucose (MD=?0.57, 95%CI ?0.69 to ?0.45, P<0.000 01), glycosylated hemoglobin (MD=?0.28, 95%CI ?0.33 to ?0.22, P<0.000 01), high density lipoprotein (MD=0.06, 95%CI 0.01 to 0.11, P=0.01), low density lipoprotein (MD=?0.35, 95%CI ?0.47 to ?0.24 , P<0.000 01), total cholesterol (MD=?0.25, 95%CI ?0.39 to ?0.12, P=0.000 3), steady-state model-insulin resistance index (MD=?0.74, 95%CI ?0.80 to ?0.68, P<0.000 01), and body mass index (MD=?0.54, 95%CI ?1.03 to ?0.05, P=0.03) compared with control group. ConclusionsResistance exercise can improve the blood glucose, blood lipid, and insulin resistance levels of individuals with abnormal glucose and lipid metabolism. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify above conclusions.
Objective To investigate the characteristics of the pathogens causing bloodstream infection after general surgery in infant and young children patients, and to provide the references for disease treatment and nosocomial infection control. Methods The clinical and laboratory examination data after general surgery in infant and young children patients, who were admitted to our hospital from January 2012 to March 2017, were retrospectively collected. The pathogens and drug resistance were analyzed by SPSS 18.0 software. Results In this study, 109 cases were included, and 117 strains of the pathogens were isolated, including 53 isolates (45.3%) of gram negative bacteria, 41 isolates (35.0%) of gram positive bacteria, and 23 isolates (19.7%) of fungi. Escherichia coli (16/117, 13.7%), Enterococcus faecium (13/117, 11.1%), Candida parapsilosis (12/117, 10.3%), Klebsiella pneumoniae (9/117, 7.7%) and Enterococcus faecalis (8/117, 6.8%) were the top 5 species. Strains producing extended-spectrum beta-lactamase accounted for 87.5% of E. coli (14/16) and 44.4% (4/9) of K. pneumoniae isolates. Both E. faecium and E. faecalis were susceptible to vancomycin. C. parapsilosis showed the susceptibility to the antifungal agents. Conclusion Gram negative bacteria are predominant pathogens causing bloodstream infection after general surgery in infant and young children patients, and infection caused by resistant isolates should be prevented and controlled.
Objective To analyze the species distribution and resistance of the pathogens isolated fromblood cultures of the patients in intensive care unit ( ICU) , and provide a basis for prevention and control of bloodstream infections in critically ill patients. Methods The data of blood cultures of the patients in ICUduring January 2009 to December 2011 was investigated retrospectively.Results In the last 3 years, positive rate of blood cultures of ICU patients was 15. 4% , 15. 7% , and 17. 6% respectively. Among the isolates, Gram-positive bacteria were predominant ( 52. 3% ) , followed in order by gram-negative bacteria ( 33. 1% ) and fungi ( 14. 7% ) . Aerobe and facultative anaerobe were the predominant bacterial isolates ( 99. 7% ) . Enterococcus faeciumand Staphylococcus spp. were the most common gram-positive bacteria, and 4. 5% of E. faecium isolates were resistant to vancomycin. Rate of methicillin-resistance for S. aureus and S. epidermidis was 73. 5% and 93. 7% respectively. In terms of gram-negative bacteria, Acinetobacter calcoaceticus- A. baumannii complex were the leading species, 96. 9% of the isolates had multi-drug resistance and 14. 1% of the isolates had extra-drug resistance. Klebsiella pneumonia and Escherichia coli isolates were less frequently isolated and those producing extended spectrum beta-lactamases accou ted for 70. 3% and 80. 0% of the isolates respectively. Candida spp. was the most common fungi isolates ( 96. 7% )with an annual change of species distribution and declining susceptibility to azoles.Conclusions Gram-positive bacteria should be the major target for prevention and control of bloodstream infections in critically ill patients. Whereas, more attention should be paid to the infection caused by candida spp. and multidrug resistant gram-negative bacteria.
Objective To investigate the characteristics of the pathogens isolated from the cerebrospinal fluid (CSF) and the prognosis of the adult patients with central venous system (CNS) infection, and to provide the basis for disease treatment. Methods The clinical data and findings of the laboratory examination of the patients, who were admitted to West China Hospital of Sichuan University from January 2014 to September 2016, and suffered from CNS infection with the positive results of CSF culture, were retrospectively analyzed. The species distribution and in-vitro susceptibility of the pathogens and hospital mortality were analyzed. Results A total of 157 cases, involving 87 (55.4%) community-acquired cases and 70 (44.6%) hospital-acquired cases, were included. One hundred and fifty-eight strains of the pathogens were isolated from the CSF specimens of these patients, including 73 isolates (46.2%) of gram negative bacteria, 64 isolates (40.5%) of fungus, and 21 isolates (13.3%) of gram positive bacteria. In terms of species distribution,Cryptococcus neoformans was the predominant (62/87, 71.3%) species isolated from the patient with community-acquired infection, whileAcinetobacter calcoaceticus-A. baumannii complex (31/71, 43.7%) was the predominant specie from the patients with hospital-acquired infection. Analysis of the resistance phenotypes showed that all theC. neoformans isolates were susceptible to the antifungal agents. More than 90% ofA. calcoaceticus- A. Baumannii complex isolates were resistant to the regular antibiotics. The resistant rates ofK. pneumoniae isolates to the regular antibiotics were no more than 25%. The hospital mortality of the groups infected by gram-negative bacteria, fungi, and gram-positive bacteria were 52.3% (38/72), 32.8% (21/64), and 19.0% (4/21), respectively. There was statistical difference for the hospital mortality among these groups (P=0.006). Conclusion In our hospital,C. neoformans are the common species isolated from CSF of the patients with community-acquired CNS infection. Gram negative bacilli are commonly isolated from CSF of the hospital-acquired cases. The mortality of patients with gram negative bacilli is high.
ObjectiveTo explore the effects of different exercise methods on serum short-chain fatty acids (SCFA) in type 2 diabetic mice, determine the best exercise method to improve SCFAs in type 2 diabetic mice, and provide a theoretical basis for the preventive intervention for patients with early diabetes.MethodsAccording to different exercise methods, 48 8-week-old male db/db type 2 diabetic mice were randomly divided into four groups, including aerobic exercise group, resistance exercise group, combined resistance- aerobic exercise (referred to as combined exercise) group, and the control group; with 10 mice in each group and another 2 as the substitutes. The mice were fed in the same manner in each group. The control group did not perform exercise intervention, the aerobic exercise group performed weightless running exercise, the resistance exercise group performed tail weight-bearing ladder exercise, and the combined exercise group alternated aerobic exercise and resistance exercise. Blood glucose and body weight were measured before and 8 weeks after the intervention. The content of serum SCFAs in mice was determined by gas chromatography-mass spectrometry.ResultsA total of 40 mice completed the experiment successfully. Before the exercise intervention, there was no significant difference in blood glucose or weight among the groups (P>0.05). After 8 weeks of exercise intervention, the blood glucose and weight in each exercise group were significantly lower than those in the control group (P<0.05), and the blood glucose and weight in the combined exercise group were significantly lower than those in the aerobic exercise group and the resistance exercise group (P<0.05). The contents of SCFA were higher in the aerobic exercise group, resistance exercise group, and combined exercise group than those in the control group (P<0.05); the contents of acetic acid and butyric acid in the combined exercise group were better than those in the aerobic exercise group (P<0.05), and the contents of propanoic acid and valeric acid in the combined exercise group were better than those in the resistance exercise group (P<0.05).ConclusionsDifferent exercise methods can improve the SCFA content in serum of type 2 diabetic mice. Compared with aerobic exercise and resistance exercise, combined exercise has the best effect in improving SCFA.
Objective To systematically review the resistance of pseudomonas aeruginosa to quinolone in China. Methods Such databases as CNKI, WanFang Data, CBM, VIP, PubMed, EMbase and The Cochrane Library were electronically searched from inception to December 2012, for relevant studies on the resistance mechanism of pseudomonas aeruginosa to quinolone. Two reviewers independently screened literature according to inclusion and exclusion criteria. Then, meta-analysis was performed using RevMan 5.0 software. Results Totally 19 studies were included, involving 723 strains of quinolone-resistant pseudomonas aeruginosa. The statistical results showed that, in the areas to the north of Huai River, the detection rates of gyrA, gyrB, parC and parE were 88.0%, 13.3%, 31.4% and 16.7%, respectively; and in the areas to the south of Huai River, they were 64.6%, 50.0%, 35.4% and 16.7%, respectively. The detection rates of plasmid mediated resistant genes aac (6’)-Ib-cr was 0 (0/66) in the areas to the north of Huai River, and 39% (25/64) in the areas to the south of Huai River. The outer membrane protein expression rate of active efflux system was 68.1%. Conclusion In China, gyrA gene mutation and the active efflux system mainly account for pseudomonas aeruginosa’s resistance to quinolone. DNA topoisomerase IV abnormalities and plasmid mediated resistance is the secondary mechanism.
ObjectiveTo explore the risk factors for neonatal nosocomial infection and the pathogen resistance, in order to provide the basis for hospital infection control. MethodsSurveillance of hospital infection in newborns hospitalized for more than 48 hours were carried out from January to December 2012, and the risk factors for hospital infection were analyzed. ResultsThere were 54 newborn cases with neonatal nosocomial infection, and the infection rate of newborns was 1.25%. The major infection sites were respiratory tract (66.7%), gastrointestinal tract (18.5%), skin and soft tissues (9.2%). Birth weight (χ2Trend=126.88, P<0.001), hospitalization days (χ2Trend=106.89, P<0.001), invasive operation (χ2=5.338, P=0.021) were the major risk factors. A total of 54 strains of pathogenic bacteria were isolated from 54 newborn cases with neonatal nosocomial infection. Twenty-three strains of gram-positive bacteria accounted for 42.6%, which were generally resistant to penicillin and large ring lactone class antibiotic drugs. Thirty-one strains of gram-negative bacteria accounted for 57.4%, which were mainly resistant to the three generations of cephalosporins. ConclusionThe hospital infection rate of newborns is low. Birth weight, hospitalization days and invasive operation are the major risk factors for neonatal nosocomial infection.
Objective To evaluate the influence on the estimation of respiratory mechanics with dynamic signal analysis approach during noninvasive positive pressure ventilation (NPPV) under different inspiratory effort conditions. Methods The Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in healthy adults with body weight from 65 to 70 kg, and patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress (ARDS). Each lung models was subjected to 4 different muscle pressures (Pmus): 0, 5.0, 10.0, and 15.0 cm H2O. Inspiratory pressure support level was adjusted to maintain tidal volume (VT) achieving 7.0 mL/kg outputted by ventilator respectively. Positive end expiratory pressure was set at 5.0 cm H2O and back-up rate was 10 beats per minute. Measurements were conducted at system leaks with 25 to 28 L/min. The respiratory system compliance (Crs), inspiratory and expiratory resistance (Rinsp and Rexp) were estimated by special equations, which was derived from the exhaled VT, flow rate and airway pressure. Results The driving pressure (DP) was decreased with Pmus increasing, and was 1.0 cm H2O after Pmus exceeding 10.0 cm H2O and the VT was larger than 7.0 mL/kg in normal adult model. The estimated value of Crs was affected by the changes of Pmus in all three lung models. The significant underestimation of Raw and the overestimation of Crs were observed when Pmus level exceed 10.0 cm H2O. The measured errors of Crs and Rexp were within 10% in COPD and ARDS model when Pmus was at 5.0 cm H2O. The underestimation of Rinsp was always existed in all Pmus level (P<0.01). Conclusions Using dynamic signal analysis approach, the real-time estimation of respiratory mechanics (Crs and Raw) is no need to interrupt the spontaneous breathing during NPPV. Excessive effort will increase the patient’s inspiratory workload, which is not benefit to accurate estimation of respiratory mechanics.
Objective To describe and compare the distributions of aminoglycosides modifying enzymes ( AMEs) in imipenem-resistant Pseudomonas aeruginosa ( IRPA) collected from5 cities in China. Methods A total of 146 strains of IRPA were collected from 5 cities of China ( Chengdu, Hangzhou, Beijing, Shanghai, and Guangzhou) . The polymerase chain reaction ( PCR) were used to amplify the genes of AMEs in IRPA. Results Six positive genotypes were amplified out of 16 genotypes of AMEs by PCR. The total positive rate of AMEs is 65. 06% . The positive rates of genes of aac( 3) -Ⅱ, aac( 6′) -Ⅰ, aac( 6′) -Ⅱ, ant( 2″) -Ⅰ, ant ( 3″) -Ⅰ and aph( 3′) -Ⅵ were 33. 6% , 15. 8% , 19. 9% , 28. 8% , 14. 4%, and 4. 8% , respectively. The genotypes of AMEs were discrepant in different areas as 6 genotypes in Huangzhou and Shanghai, 4 genotypes in Chengdu and Beijing, and 3 genotypes in Guangzhou. Conclusion The results show that the positive rate of AMEs genes is high in IRPA, and the distribution is discrepant among different areas.