ABSTRACT
Objective To study the antibacterial property of silver loaded titanium dioxide (TiO2) antibacterial coated endotracheal intubation tube,and to determine the minimum effective antibacterial concentration.Methods Intubation tubes coated with different concentrations of antibacterial agents were prepared with sol gel method.Polyethylene endotracheal intubation tubes were used as substrate,and silver loaded TiO2 was used as the antibacterial agent.According to the different antibacterial concentrations of the antibacterial agent,the tubes were divided into nine groups:10.0％ group,5.0％ group,2.0％ group,1.5％ group,1.0％ group,0.8％ group,0.6％ group,0.2％ group,and conrol group.They were respectively immersed in three standard bacteria suspensions with 1.0 × l05 cfu/mL:Pseudomonas aeruginosa,Staphylococcus aureus,and Escherichia coll Together with standard bacteria liquid group,there were 10 experimental groups.They were kept overnight for 24 hours.10 μL of respective culture medium was smeared on blood agar culture medium.After being cultured overnight in 35 ℃,the number of bacteria colonies was respectively counted.Results In 1.0 × 105 cfu/mL of three standard bacteria liquids with antibacterial agent concentration≥ 1.0％,three bacterial colonies had un-obviously growth rate.Almost the same strong antibacterial effects to achieve sterilizing rates of more than 98％ was shown in each group of the antibacterial coating endotracheal intubation tubes (all P＞0.05).As the antibacterial agent concentration decreased,three bacterial colonies were increasing gradually.Intermediate antibacterial effects were shown in tubes of 0.8％ group,with significant statistic difference as compared with 1.0％ and 0.6％ groups [Pseudomonas aeruginosa:7.300 (4.050,8.350) vs.0.200 (0.050,1.200),9.700 (9.000,10.000); Staphylococcus aureus:4.100 (3.300,4.650) vs.0.000 (0.000,0.150),5.800 (5.350,7.650); Escherichia coli:1.400 (0.750,3.750) vs.0.050 (0.025,0.050),9.500 (8.500,9.800),all P＜0.01].Conclusions Silver loaded TiO2 antibacterial coated endotracheal intubation tube had definite antibacterial properties,which were related to the antibacterial concentration.Strong antibacterial effects were shown when antibacterial concentration was above 1.0％,with bacteria almost completely killed in the immersing liquid.
ABSTRACT
Objective To analyze the bacterial distribution and resistance of clinical isolates from exacerbation of COPD patients in C and D classification in our emergency department.Methods The sputums were taken to culture and antimicrobial susceptibility test.VITEK-2 compact automicrobe system was used to identify bacteria.Disc diffusion test was used to determine the antimicrobial resistance.Results Of 222 clinical isolates,27.0％ were Gram positive bacteria,73.0％ were Gram negative bacteria.The Gram positive bacteria mainly was Staphylococcus aureus and Streptococcus pneumoniae.The detection rates of methicillin-resistant Staphylococcus aureus (MRSA) were 50.00％.The MRSA were more resistant than methicillin-sensitive Staphylococcus aureus (MSSA),and they were all sensitive to vancomycin,linezolid or tigecycline.The Gram negative bacteria mainly was Pseudomonas aeruginosa,Escherichia coli,Klebsiella spp and Acinetobacter baumannii.Pseudomonas aeruginosa and Acinetobacter baumannii had high resistant rates.The extended spectrum β-lactamases (ESBLs) producing strains in Escherichia coli were higher than in Klebsiella spp,which had multiple drug resistance.Conclusions The bacterial resistance situation is very severely in exacerbation of COPD patients in C and D classification in our emergency department.The first isolating rate was Pseudomonas aeruginosa.Surveillance of bacterial resistance is very important and effective control measures to reduce resistance is very necessary.