Analysis of drug resistance and risk factors of multi drug resistant bacteria in bloodstream infection / 中国热带医学

@#Abstract: Objective To analyze the antimicrobial resistance rate and risk factors of multi drug resistant organisms (MDRO) in bloodstream infection for rational treatment. Methods　A total of 696 cases of bloodstream infections of Staphylococcus aureus, Enterococcus, Enterobacteriaceae (excluding Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter in our hospital from 2017 to 2021 were selected, and 711 pathogenic strains were isolated from their whole blood samples. The antimicrobial resistance rates of various multi drug resistant strains were analyzed and the risk factors of MDRO infection were analyzed. Results　696 non repeated cases were screened out from 13 187 whole blood culture specimens, with a positive rate of 5.3%, and a total of 711 blood influenza pathogens were detected, among them, 350 strains of MDRO were detected with a detection rate of 49.23% (350/711). Among the pathogenic bacteria of bloodstream infection, Escherichia coli was the most, with 277 strains accounting for 38.96% (277/711), of which 201 strains were MDRO, accounting for 57.43% (201/350); followed by Klebsiella pneumoniae and Staphylococcus aureus, with 155 strains accounting for 21.80% (155/711) and 89 strains accounting for 12.52% (89/711), among which 43 strains of Klebsiella pneumoniae MDRO accounted for 12.29% (43/350) and 38 strains of Staphylococcus aureus MDRO accounted for 10.86% (38/350). The change trend of the three pathogens during 2017-2021 was not obvious. The drug sensitivity test showed that Escherichia coli and Klebsiella pneumoniae were highly resistant to cephalosporins and fluoroquinolones, and the drug resistance rate of aminoglycosides was relatively low. They had almost no resistance to cephalosporins and carbapenems. Staphylococcus aureus has a high resistance rate to lincomycin and macrolides, but no resistance to oxazolidinone, glycopeptides and glycylcyclins. There were 350 cases of MDRO infection and 361 cases of non MDRO infection. Univariate analysis showed that the age, sex, cardiovascular and cerebrovascular history, renal insufficiency, lung disease, hypoalbuminemia, hepatobiliary disease, electrolyte disorder and anemia of the patients had no statistical significance in MDRO infection (P>0.05); diabetes, urinary tract infection, surgical operation and burn were the influencing factors of MDRO (P<0.05). According to logistic analysis, diabetes, urinary tract infection, surgical operation and burn were the risk factors of MDRO infection (P<0.05). Conclusion　The infection of MDRO in patients with bloodstream infection is serious, and early prevention and control should be paid attention to, and the principle of graded use of antibiotics should be strictly observed, and the rational application should be carried out to actively and effectively control the production of MDRO.

Id-1 expression in colorectal adenocarcinoma tissues and its clinical significance

SUMMARY BACKGROUND: This study aims to investigate the expression of Id-1 in human colorectal adenocarcinoma tissues and explore its correlation with the clinical pathological parameters of colorectal cancer. METHODS: The Id-1 mRNA and protein expression levels of 50 specimens of normal colorectal tissues and 50 specimens of colorectal adenocarcinoma tissues were detected using reverse-transcription polymerase chain reaction and western blot. Furthermore, Id-1 protein was detected using immunohistochemistry. The correlation between the expression of Id-1 and clinicopathologic features was analyzed. RESULTS: The mRNA expression level of Id-1 in colorectal adenocarcinoma tissues and normal colorectal tissues was 0.96 ± 0.03 vs. 0.20 ± 0.04, respectively; and the difference was statistically significant (P=0.011). Furthermore, Id-1 protein expression was higher in colorectal adenocarcinoma tissues than in normal colorectal tissues (0.82 ± 0.04 vs. 0.31 ± 0.02, P=0.020). In addition, the positive protein expression rate of Id-1 was higher in colorectal adenocarcinoma tissues than in normal colorectal tissues (72.00% vs. 24.00%, X2=23.431, P=0.000). The expression of Id-1 was correlated with the depth of tumor invasion, TNM stage, lymph node metastasis, vessel invasion, and liver metastasis (P<0.01). However, this expression was not correlated with tumor size and differentiation degrees (P>0.05). CONCLUSIONS: The high Id-1 expression in colorectal adenocarcinoma tissues play an important role in the process of cancer, and is expected to become a new tumor monitoring indicator for clinical diagnosis, treatment, and prognosis judgment.

RESUMO OBJETIVO: O objetivo deste estudo é investigar a expressão de Id-1 em tecidos de adenocarcinoma colorretal em humanos e investigar sua correlação com os parâmetros patológicos clínicos de câncer colorretal. MÉTODOS: Os níveis de expressão de proteína e mRNA Id-1 em 50 amostras de tecido colorretal normal e 50 amostras de tecido de adenocarcinoma colorretal foram detectados através de reação em cadeia de polimerase precedida de transcrição reversa e western blot. Além disso, a proteína Id-1 foi detectada através de imuno-histoquímica. A correlação entre a expressão de Id-1 e características clínico-patológicas foi analisada. RESULTADOS: O nível de expressão de mRNA Id-1 em tecidos de adenocarcinoma colorretal e tecidos colorretais normais foi de 0,96 ± 0,03 versus 0,20 ± 0,04, respectivamente; a diferença foi estatisticamente significativa (P= 0,011). Além disso, a expressão da proteína Id-1 foi maior em tecidos de adenocarcinoma colorretal do que em tecidos colorretais normais (0,82 ± 0,04 versus 0,31 ± 0,02, P= 0,020). Além disso, a taxa de expressão positiva de proteínas Id-1 foi maior em tecidos de adenocarcinoma colorretal do que em tecidos colorretais normais (72,00% vs. 24,00%, X2=23,431, p=0,000). A expressão de Id-1 foi correlacionada com a profundidade da invasão tumoral, estágio TNM, metástases linfonodais, invasão vascular e metástase hepática (P<0,01). Todavia, essa expressão não se correlacionou com o tamanho do tumor e graus de diferenciação (P>0,05). CONCLUSÃO: A alta expressão de Id-1 em tecidos de adenocarcinoma colorretal desempenham um importante papel no processo do câncer, e é esperado que se torne um novo indicador de monitoramento de tumores para o diagnóstico clínico, tratamento e estimativa de prognóstico.

Cultivation and identification of colon cancer stem cell-derived spheres from the Colo205 cell line

Our group established a method to culture spheres under serum-free culture condition. However, the biological characteristics and the tumorigenicity of spheres are unknown. Here, we demonstrate that sphere cells expressed high levels of the putative colorectal cancer stem cell markers CD133 and CD44. The CD133-positive rates were 13.27 ± 5.62, 52.71 ± 16.97 and 16.47 ± 2.45 percent in sphere cells, regular Colo205 cells and differentiated sphere cells, respectively, while the CD44-positive rates were 62.92 ± 8.38, 79.06 ± 12.10 and 47.80 ± 2.5 percent, respectively, and the CD133/CD44-double-positive rates were 10.77 ± 4.96, 46.89 ± 19.17 and 12.41 ± 2.27 percent, respectively (P < 0.05). Cancer sphere cells formed crypt-like structures in 3-D culture. Moreover, cells from cancer spheres exhibited more tumorigenicity than regular Colo205 cells in a xenograft assay. The cancer sphere cells displayed much higher oncogenicity than regular Colo205 cells to initiate neoplasms, as assayed by H&E staining, Musashi-1 staining and electron microscopy. Our findings indicated that the sphere cells were enriched with cancer stem cells (CSCs), and exhibited more proliferation capacity, more differentiation potential and especially more tumorigenicity than regular Colo205 cells in vitro and in vivo. Further isolation and characterization of these CSCs may provide new insights for novel therapeutic targets and prognostic markers.