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Objective: To evaluate the diagnostic efficiency of colloidal gold and dot ELISA rapid tests in clinical screening of influenza A virus., Methods: The pharyngeal swabs were collected from 297 outpatients suspected of influenza between June and October, 2009 for detection with colloid gold and dot ELISA rapid test, with real-time PCR as the golden methods. The discrepant results of colloid gold and dot ELISA methods were confirmed by sequencing, and the diagnostic efficiency of the two methods was evaluated., Results: Among the 166 samples with influenza A virus infection as confirmed by real-time PCR and sequencing, the diagnostic sensitivity of dot ELISA and colloid gold methods was 54.82% (91/166) and 4.22% (7/166), respectively. The total concordance rate with PCR was 66.67% (Kappa value of 0.35). Among the 133 samples negative for influenza A virus, the specificity of dot ELISA and colloid gold methods was 81.68% (107/131) and 98.47% (129/131), respectively, with a total concordance rate with PCR of 45.79% (Kappa value 0.02). Of the 99 H1N1 influenza samples confirmed by real-time PCR, the detection rate of dot ELISA was 67.3%, whereas that of colloid gold was 5.1%. Out of the 107 dot ELISA-positive but colloid gold-negative samples, 84 were confirmed to be influenza A virus-positive by real-time PCR and sequencing. One sample negative for dot ELISA but positive for colloid gold test was confirmed to be influenza A virus-negative. The detection rate and diagnostic concordance rate for influenza A virus by dot ELISA were significantly higher than those of colloid gold (P<0.05)., Conclusion: Dot ELISA is better than colloid gold in influenza A virus detection and shows great prospect in clinical screening.

This study was aimed to establish the method of quantitative PCR (q-PCR) of fungi in peripheral blood for diagnosis of invasive fungal infections in patients with hematologic malignancies, and to preliminarily assess the diagnostic value of this method. The 18S rDNA-ITS1 area of high consensus sequence of fungi was selected to design primer and probe, the DNA of fungal species was extracted and q-PCR was performed to evaluate the sensitivity and specificity of the primer and probe. The standard product of fungal DNA was prepared by using pGEM-T plasmid and the fungal DNA in blood of patients was quantitatively detected. The results showed that the positive was found in 12 Aspergillus and 14 Candida species according to q-PCR detection, while there was no significant difference of fungal distribution between plasma, mononuclear cells and leukocytes (p<0.05). Receiver-operating characteristic analysis of q-PCR showed that the cut-off value for clinical diagnosis of invasive fungal infection was 8 copies/ml whole blood, its sensitivity, specificity, positive and negative predictive value and kappa were 0.84, 0.9, 0.955, 0.692 and 0.679 respectively. It is concluded that the fungal q-PCR assay may be used as an early diagnostic method for invasive fungal infections in patients with hematologic malignancies.

Objective: To investigate the molecular epidemiological characteristics of Staphylococcus aureus associated with bloodstream infection in hospital., Methods: 47 Staphylococcus aureus strains isolated from bloodstream in PLA General Hospital were collected from January 2006 to December 2008. Susceptibility of the strains to 11 antimicrobial agents was detected and DNA homology of them was analyzed with Rep-based DiversiLab(TM) Microbial Typing System. Panton-Valentine leukocidin (PVL) gene was determined by PCR. For methicillin-resistant Staphylococcus aureus (MRSA) strains, the genotypes of SCCmec were determined and ST239 clone was screened with multiplex PCR. Multilocus sequence typing (MLST) was used to determine the STs of the selected isolates., Results: In the 47 Staphylococcus aureus isolated from blood, methicillin-resistant strains accounted for 51.1%, all belonged to SCCmec III type, with only 2 pvl gene positive strains identified. 12 different patterns (A-L) were found among 47 strains with Rep-PCR. All MRSA strains clustered in the A and B subtypes., Conclusion: Most MRSA strains isolated from blood in PLA General Hospital belonged to ST239-MRSA-SCCmec III clone. DiversiLab(TM) Microbial Typing System could provide a rapid and effective method to investigate the molecular epidemiological characteristics of Staphylococcus aureus in the hospital settings.

Invasive fungal infections (IFI) are a kind of the most severe complications after hematopoietic stem cell transplantation (HSCT), Candida and Aspergillus are common causes. Because of immunosuppressive therapy, ablative conditioning regimen, acute or chronic graft-versus-host disease, long-term treatment of broad-spectrum antibiotics and cytomegalovirus infection, IFI has increased in the past few years. Invasive mould infection is a major cause of morbidity and mortality in HSCT recipients. Methods for early diagnosis of IFI include clinical and laboratory examinations, as well as characteristic radiography. Voriconazole is the first-line antifungal agent for prevention of IFI. Combination therapy of two antifungal compounds such as azoles or amphotericin B with echinocandins have shown a good effectiveness and may be a promising future strategy for antifungal treatment. In this review, the early diagnosis and treatment of IFI in HSCT recipients are summarized. As for early diagnosis of IFI, the laboratory diagnosis techniques such as GM test, G test and PCR techniques are discussed. As for prophylaxis and treatment of IFI, the prophylaxis treatment, empirical treatment, preemptive treatment, targeted treatment, combined treatment and immunologic treatment are discussed.

Objective: To investigate antibiotic resistance, carbapenemase genotype and the molecular epidemiology of multidrug-resistant Acinetobacter baumannii (Aba) collected from 3 military hospitals in China., Methods: The minimum inhibitory concentrations (MIC) were examined by ager dilution method. Genotypes of carbapenemases were amplified by multiplex PCR and its products were sequenced. PCR was used to detect per gene. Homology of the resistant isolates was analyzed by pulse-field gel electrophoresis (PFGE)., Results: Among the 64 MDRA strains, 78.1% (50) strains possessed bla(OXA-23) gene, 89.1% (57) carried Class 1 integrase gene, 39.1% (25) with bla(PER-1) gene, and 1 strain with bla(OXA-58-like) gene. PFGE showed that 13 (A, B, C, D, E genotype) different clones were identified in these strains. A, B, and U clones were the predominant clones in three hospitals, respectitively., Conclusion: Outbreaks of multidrug-resistant Aba occurred at 3 military hospitals with the most prevalent carbapenemase as OXA-23 enzyme. OXA-58 type of carbapenemase and per-1 in Aba were also isolated.

Objective: To study the mode of transmission and molecular characteristics on carbapenem-resistant Acinetobacter baumannii strain. Strains were isolated from different parts of samples in various patients., Methods: Clinical information of carbapenem-resistant Acinetobacter baumannii isolates were stored and analyzed by WHONET 5.4 software. The transmission and pathopoiesis of the strains were learned through case file review. Genotypes of isolates were identified by pulse-field gel electrophoresis (PFGE) and genes of carbapenemase were detected by multiple PCR, in order to find molecular characteristics and relatedness between strains., Results: 29 stains of Acinetobacter baumannii resistant to carbapenem were isolated from 2 or more kinds of samples among 13 patients'. Two genotypes were identified by PFGE: genotype A was obtained from 22 isolates in 11 patients and genotype B was obtained from 7 isolates in 4 patients. PCR amplification showed that all strains possessed OXA-23 gene except 1, and all strains possessed Integrase gene I except 3., Conclusion: There were 2 different genotypes from 29 strains of carbapenem-resistant Acinetobacter baumannii with Genotype A as the main type. OXA-23 carbapenemase gene and integrase gene I were detected from most of the isolates. All the strains could be easily transmitted in the body of the patients and among patients, hence becoming the epidemic pathogen of iatrogenic infection.