Objective To analyze the characteristics of pathogens causing bloodstream infection (BSI) after cardiovascular surgery, and provide instructions for prevention and treatment of such kind of disease. Methods A retrospective investigation of clinical and pathogenic data of the patients suffering from BSI after cardiovascular surgery in West China Hospital of Sichuan University from January 2015 to December 2016 was performed. There were 61 patients with 36 males and 25 females at average age of 48.2±17.1 years. A percentage of 65.6% (40/61) of the underlying diseases was rheumatic heart disease. Results Sixty-five strains were isolated from the blood culture specimens of the 61 patients. Gram-positive bacteria, gram-negative bacteria and fungi isolates accounted for 56.9% (37/65), 35.4% (23/65), and 7.7% (5/65), respectively. Among these isolates, Streptococcus spp. was predominant (19/65, 29.2%), followed by Staphylococcus epidermidis (8/65, 12.3%), Staphylococcus aureus (6/65, 9.2%), Acinetobacter calcoaceticus- A. baumannii (5/65, 7.7%) and Escherichia coli (5/65, 7.7%). The resistance rate of Streptococcus spp. to erythromycin and clindamycin was 73.4% (14/19) and 63.2% (12/19), while its resistance to cefepime, vancomycin or linezolid was not observed. Staphylococcus spp. showed the resistance rate of 71.4% (10/14) to oxacillin. All of A. calcoaceticus-A. baumannii isolates were multidrug resistant (5/5, 100.0%), and 80.0% (4/5) of them were resistant to imipenem. The isolates producing extended spectrum beta-lactamase accounted for 80.0% (4/5) of E. coli. Conclusion Streptococcus spp. was the common pathogen causing BSI after cardiovascular surgery. Staphylococcus spp. and gram-negative bacilli show high resistance.
ObjectiveTo analyze the diagnostic efficacy of colloidal gold immunochromatography assay (GICA) in detection of SARS-CoV-2.MethodsUsing GICA detection kits from three different manufacturers, 33 serum samples were collected from 12 patients with SARS-CoV-2 infection at different time and 45 serum samples from 45 patients without SARS-CoV-2 infection were collected from West China Hospital of Sichuan University from January to February, 2020.ResultsThe sensitivity, specificity, positive predictive value and negative predictive value of the three GICA reagents were 66.7% - 90.9%, 73.3% - 100.0%, 71.4% - 100.0% and 80.4% - 91.7% respectively. The rates of missed diagnosis and misdiagnosis were 9.1% - 33.3% and 0 - 26.7%, respectively. The positive rate decreased with titer increasing. The interference factors mainly included human immunodeficiency virus infection, high rheumatoid factor blood samples, and hemolysis.ConclusionClinical laboratories should pay attention to the differences in the detection ability and potential cross-reaction of different reagents, or use a combination of multiple antibodies.
ObjectiveTo understand the drug resistance of Mycobacterium tuberculosis complex in West China Hospital, Sichuan University, analyze its drug resistance characteristics, and provide reference for the monitoring of drug-resistant tuberculosis.MethodsFrom January 2016 to March 2018, Mycobacterium tuberculosis drug susceptibility testing kit was used to detect the drug susceptibility of Mycobacterium tuberculosis culture-positive strains in Department of Laboratory Medicine, West China Hospital, Sichuan University. The tested drugs included four of the first-line anti-tuberculosis drugs: rifampicin, isoniazid, ethambutol, and streptomycin, and ten of the second-line anti-tuberculosis drugs: capreomycin, ofloxacin, ethionamide, p-aminosalicylic acid, levofloxacin, moxifloxacin, rifabutin, amikacin, kanamycin, and chlorine phenazine.ResultsA total of 130 patients (130 strains) were enrolled, including 82 newly diagnosed patients (82 strains) and 48 re-treated patients (42 strains). The drug resistance rate of the 130 patients was 37.69%. The drug resistance rate of the newly diagnosed patients (28.05%) was significantly lower than that of the re-treated patients (54.17%), and there was a statistical difference (χ2=8.794, P=0.003). The multi-drug resistance rate of the newly diagnosed patients (6.10%) was significantly lower than that of the re-treated patients (25.00%), and the difference was statistically significant (χ2=9.517, P=0.002). The resistance rate of isoniazid, rifampicin, and streptomycin in newly diagnosed patients (23.17%, 8.54%, and 7.32%, respectively) were significantly lower than those in the re-treated patients (45.83%, 41.67%, and 29.17%, respectively), and the differences were statistically significant (P<0.05). The resistance rate of ofloxacin, moxifloxacin, rifabutin and ethionamide in the newly diagnosed patients (9.76%, 8.54%, 7.31%, and 4.88%, respectively) were significantly lower than those in the re-treated patients (39.58%, 27.08%, 25.00%, and 22.92%, respectively), and the differences were statistically significant (P<0.05).ConclusionIt is necessary to strengthen the standardized treatment of patients with newly diagnosed tuberculosis, increase the treatment and management of re-treated tuberculosis patients, and prevent the generation and spread of drug-resistant patients, especially multidrug-resistant patients.