Objective To investigate the value of bronchial mucosa biopsy and quantitative culture in the differential diagnosis of lower airway bacterial colonization and infection. Methods A prospective observational cohort survey onMDR Pseudomonas aeruginosa and Acinetobacter baumannii was carried out in intubed or tracheotomized patients with invasive ventilation in respiratory intensive care unite ( RICU) . A total of 50 ICU patients were followed for the detection of MDR pathogen colonization or infection from June 2008 to October 2009. All subjects were divided into an infection group and a colonization group according to the outcome of patients discharged fromthe RICU. Baseline information, APACHEⅡ scores, and CPIS scores were recorded on individual forms for each patient untill discharge or death. Bronchial mucosa biopsy was conducted on appropriate time to identify whether the patient was comfirmed as infection. Microbiological diagnosis was performed with quantitative culture. Results Fifty patients were enrolled in this study, of which infected in 23 cases and colonized in 27 cases. The time of invasive mechanical ventilation, length ofICU stay, catheter indwelling time, and the kinds of disease were significantly different between the two groups( P lt; 0. 05) . The kinds of using antibiotics before onset of multi-drug resistance of bacteria showed that cefoxitin/ cefmetazole and mezlocillin also had significant difference between the infection group and the colonization group. The results of dynamic CPIS score of the infection group showed that scores at each timepoint were higher than those in the colonization group. However, the results of t-test showed that there was higher score in the infection group than that in the colonization group on 14 days after intubation ( P lt;0. 05) . The bronchial mucosa biopsy showed that airway inflammation was detected in 19 cases in the infection group and 9 cases in colonization group. The positive rate in the infection and the colonization group were 55. 6% and 25. 0% , respectively assessed by traditional threshold of 103 cfu/mL for PSB in quantitative bacterial culture. In addition, there was more inflammatory cells in the patients with drug-resistant pathogens infection than that in the patients without nosocomial infection. The combination of bronchial mucosa biopsy and microorganism quantitative cultures had the highest sensitivity and specificity and the highest diagnostic accuracy. Conclusions Bronchial mucosa biopsy combining microorganism quantitative culture is feasible in identifying colonized or infected bacteria. Invasive mechanical ventilation time, length of ICU stay and the catheter indwelling time extending are risk factors for bacterial colonization.
ObjectiveTo explore the effects of burn ward cleaning methods on multi-drug resistant bacteria infection, in order to improve and optimize the cleaning process and method. MethodsFrom November 2012 to October 2013, the cleaning and disinfection methods in our burn wards were regarded as the traditional cleaning methods, and from November 2013 to October 2014, the cleaning and disinfection methods were called the improved cleaning methods (new system cleaning methods). By retrospective analysis, we compared the infection rates of multi-drug resistant bacteria before and after the implementation of the new system cleaning methods. ResultsNew system methods were used in the ward environment cleaning and disinfection. The infection rate of multi-drug resistant bacteria before and after the implementation of the new system cleaning methods were 12.414‰ and 5.922‰ respectively. The methicillin resistant Staphylococcus aureus infection rate was 7.286‰ and 3.718‰, and the carbon-resistant Pseudomonas aeruginosa infection rate was 2.699‰ and 0.689‰. Both differences were significant (P < 0.05). The carbon-resistant Acinetobacter baumanii infection rate was 2.429‰ and 1.515‰ before and after the implementation of the new methods with no significant difference (P > 0.05). ConclusionAdopting new system to carry out cleaning can effectively reduce the infection rate of multi-drug resistant bacteria in the burn ward, and it is worthy of clinical popularization and application.
Objective To analyze the distribution of pathogens, drug susceptibility and multi-drug resistant bacteria (MDRB) in elderly patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated with pneumonia. Methods The clinical data of patients whose discharge diagnosis included AECOPD with pneumonia or pulmonary infection from January 2012 to December 2015 were retrospectively analyzed. Strain identification and drug sensitivity analysis were performed in the pathogenic bacterias isolated from sputum culture. Results A total of 1 978 patients were enrolled in this study, and pathogenic bacterias were isolated from the sputum of 708 patients, including 485 cases of community-acquired pneumonia (CAP) and 223 cases of hospital-acquired pneumonia (HAP); and 786 strains of pathogens were isolated (501 strains from CAP cases, 285 strains from HAP cases), including 448 strains of Gram-negative (G–) bacilli (57.0%), 117 strains of Gram-positive (G+) cocci (14.9%), and 221 strains of fungi (28.1%). Susceptibility testing results showed that G– bacilli were highly resistant to penicillins, third generation cephalosporins, ciprofloxacin, gentamicin, etc., and G+ cocci were highly resistant to penicillin, clindamycin and erythromycin. There were 238 strains of MDRB, mainly including 69 strains of Acinetobacter baumanii [multiple drug resistance rate (MDRR)=67.6%], 27 strains of Escherichia coli (MDRR=52.9%), 25 strains of Klebsiella pneumoniae (MDRR=34.2%), 33 strains of Pseudomonas aeruginosa (MDRR=33.0%) and 24 strains of Stenotrophomonas maltophilia (MDRR=100.0%). MDRR of Enterococcus genus and methicillin-resistant Staphylococcus aureus was 50.0% and 48.0%, respectively. Conclusions The pathogenic bacterias in elderly AECOPD patients complicated with pneumonia are mainly G– bacterias, and the proportion of fungal infection tends to increase. Bacterial drug resistance is serious and the MDRB tends to increase, especially in patients with HAP. Physicians should early find out the characteristics of local pathogenic bacteria and drug sensitivity, rationally select antibiotics, reduce the occurrence of drug-resistant strains and superinfection when treating the elderly patients with AECOPD complicated with pneumonia.