Bacterial disinfectant resistance is the phenomenon that minimal inhibitory concentration or minimal bactericidal concentration of a certain disinfectant increases after a certain bacterium contacts with it many times. It exists widespread. Many species of bacteria are may resistant to a certain disinfectant, and a species of bacterium is may resistant to many disinfectant Disinfectant selectivity pressure is the extrinsic agent of bacterial disinfectant resistance. Resistance mechanisms include bacterial biochemistry structure, genetics pathway and enzymology pathway. There is relationship in disinfectant resistance and drug resistance. We should strengthen study and monitoring, enact unified standard and application specification to reduce bacterial disinfectant resistance.

To determine the relationship between the intercellular adhesion operon (ica) and the biofilm production in Staphylococcus epidennidis isolates from nosocomial infection, and the affection of ica on the antibiotic susceptibility of the isolates, we collected 106 strains, epidermidis isolates from nosocomial infection specimen to detect their biofilm production by quantitative and qualitative method and investigate the existence of ica operon by PCR. The minimal inhibitory concentration (MIC) to erythromycin, ampicillin, cefoxitin, ceftriaxone, teco-planin, ciprofloxacin, tetracycline, trimethoprim-sulfamethoxazole and vancomycin were tested. Among the isolates, 33 (31. 1% ) of them were detected out carrying ica operon. The rate of biofilm production of the ica-posi-tive isolates was higher than that of the ica-negative (P =0. 001) . By adding glucose and NaCl into the culture the detection rate of biofilm production could be increased. The antibiotic susceptibility of the plankton cells of ica-positive isolates to erythromycin, cefoxitin and ceftriaxone , except ampicillin, ciprofloxacin, tetracycline and tremethoprim-sulfamethoxazole, were lower than those of ica-negative isolates. This study showed that the existence of ica operon was close related to the biofilm formation in 5. epidermidis isolates from nosocomial infection. However, the mechanism of antibiotic resistance of the strains inside the biofilm still needed to be illustrated.

Objective To determine the genotypes and their epidermiology of microlide, lincosamide and streptogramin B(MLS_B)resistant S.epidermidis isolates causing nosocomial infection.Method 126 isolates were collected from inpatients in three hospitals in Beijing from 2003-2004 for testing the antibiotic susceptibility to the macrolide erythromycin,the lincosamide clindamycin.The resistance phenotypes of erythromycin-resistant isolates were determined by the double-disc test with erythromycin and clindamycin.The presence of the relative genes(ermA,ermB,ermC and msrA)to MLS_B resistance was identified by PCR and the similarity of the isolates was analyzed by PFGE.Result The isolates were mostly resistant to macrolide and lincosamide.In the constitutive phenotype cMLS_B isolates,the methicillin resistant S.epidermidis(MRSE)proportion appeared high(78.5%),whereas high methicillin susceptible S.epidermidis(MSSE)proportion was found in the inducible MLS_B phenotype(iMLS_B) (69.2%).ermC was shown as the most frequent determinant to the resistance,not only in MRSE and MSSE (70.8% and 6.8%),but also in iMLS_B and cMLS_B(76.9% and 90.3%).No specific endemic strain was found by PFGE analysis.The same resistance phenotype pattern was not clustered together and distributed into type A～F at the similarity of 60%.Among the phenotypes(cMLS_B,iMLS_B and MS phenotype),no significant difference was shown in the PFGE genotype distribution.Conclusion Our results indicate that the MLS_B resistance in S.epidermidis causing nosocomial infection is prevalent in the hospital and MLS_B antibiotics should be used iudiciously,ermC was shown as the most frequent determinant to the resistance.

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.
Aspergillus ; isolation & purification ; Candida ; isolation & purification ; Female ; Hematologic Neoplasms ; complications ; microbiology ; Humans ; Male ; Mycoses ; complications ; diagnosis ; Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

OBJECTIVETo explore the apoptosis resistance induced by Leptin and its mechanism in breast cancer cells in vitro.

METHODSThe leptin-mediated reduction of docetaxel-induced apoptosis in human breast cancer T47D cells was evaluated by TransAM ELISA, MTT and caspase-9 assay. The leptin-promoted survivin expression was analyzed by Western-blot and RT-PCR. The reversing effect of STAT3 knockdown on leptin-induced survivin upregulation was measured by Western-blot and RT-PCR.

RESULTSLeptin promoted T47D cells proliferation and the inhibitory rate was -63.6%. It reduced docetaxel-induced apoptosis in T47D cells by 31.9%. Leptin at different concentrations promoted survivin protein and mRNA expression in T47D cells. The expression of survivin mRNA was 4.6 fold compared with the T47D cells not treated with leptin(10 nmol/L). The expression of survivin mRNA in T47D cells was 0.55 +/- 0.15 fold after transfected with small interfering RNA (siRNA) of STAT3. The expression of survivin mRNA in STAT3 siRNA group and mock transfected group were 0.56 +/- 0.18 fold and 1.61 +/- 0.22 fold after treated by leptin, respectively. The survivin protein level of T47D mock transfected cells was increased after treated by leptin, but the protein level of T47D transfected with STAT3 siRNA cells were not changed significantly.

CONCLUSIONLeptin/STAT3 signaling is a novel pathway for up-regulation of survivin expression in breast cancer cells.

Apoptosis ; drug effects ; Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; Leptin ; pharmacology ; Microtubule-Associated Proteins ; genetics ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; STAT3 Transcription Factor ; genetics ; metabolism ; Signal Transduction ; Transfection ; Up-Regulation

OBJECTIVEBy measuring airflow and ventilation distribution of ward building, to explore and verify the hypothesis of airborne transmission and risk factor of severe acute respiratory syndrome (SARS) nosocomial infection.

METHODSTracer gas (perfume of plant oil) was emitted to the bathroom of wards when SARS index patient lived. Six different experimental situations were designed to control the status of exhaust fan in bathrooms, exhaust fan in the top of building and fresh air exchange system. The concentration of perfume was separately measured by 4 groups of lab workers and recorded blindly by the scores of "tenth degree".

RESULTSTracer gas was detected from the wards of 8th to 13th floor.

CONCLUSIONArchitecture and ventilation system of the inpatient building in the hospital contributed to the aerodynamic condition of SARS nosocomial infection through airborne transmission. The distribution of tracer gas in the wards was associated with SARS patients in this building. It was possible that SARS could have been transmitted to for distance by aerosol or other carriers.

Air Microbiology ; China ; Cross Infection ; etiology ; Hospitals ; Humans ; SARS Virus ; isolation & purification ; Severe Acute Respiratory Syndrome ; transmission ; Ventilation

China ; Female ; Health Services Needs and Demand ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza Vaccines ; therapeutic use ; Influenza, Human ; prevention & control ; Intention ; Male ; Medical Staff ; Pregnancy ; Students ; Vaccination ; statistics & numerical data

BACKGROUNDThe duration of viral shedding and the transmission of 2009 H1N1 influenza among individuals, especially among the younger population with mild illness, are not well understood now. The aim of this study was to determine the viral shedding of the young adult patients with mild 2009 H1N1 influenza in China.

METHODSFrom September 2009 to January 2010, the clinical data and serial nasopharyngeal swabs of 67 patients with 2009 H1N1 influenza and 37 patients with seasonal influenza aged from 18 years to 35 years were collected. The nasopharyngeal swab samples were detected by real time RT-PCR to determine the viral shedding. All the patients did not receive the antiviral therapy but Chinese medicine for detoxicating.

RESULTSAmong the patients with H1N1 virus infection, 82.1% (55/67) patients presented with fever symptom, while more patients with high fever (≥ 39°C) were found in seasonal influenza patients (P < 0.05). For the H1N1 patients, the median interval between the symptom onset and the undetectable RNA was six days (4 - 10 days). But viral shedding was still found in 31.3% patients after 7 days following illness onset. The median interval between disappearance of fever and an undetectable viral RNA level was three days (2 - 8 days), and 17.9% patients were found to be viral shedding 6 days later after normalization of body temperature. For the seasonal influenza patients, 94.6% patients were detected out viral RNA within 7 days. The median interval of seasonal influenza between the symptom onset and the undetectable RNA was four days (3 - 8 days). The median interval between disappearance of fever and an undetectable viral RNA level was three days (2 - 6 days).

CONCLUSIONIt suggests that 7 days isolation period from the illness onset or 24 hours after the resolution of fever and respiratory symptoms are not long enough to cut off the transmission among Chinese young adults with mild illness.

Adult ; Female ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; pathogenicity ; Influenza, Human ; epidemiology ; virology ; Male ; Real-Time Polymerase Chain Reaction ; Virus Shedding ; genetics ; physiology ; Young Adult

BACKGROUNDThe catheter related infection caused by Staphylococcus epidermidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy. The properties of biofilms that give rise to antibiotic resistance are only partially understood. This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm.

METHODSThe penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457, 1457-msrA, and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve. The RNA/DNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope, respectively.

RESULTSThe penetration ratios of erythromycin through the biofilms of 1457, 1457-msrA, and S68 after cultivation for 36 hours were 0.93, 0.55 and 0.4, respectively. The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours) was higher than that through the other two (0.499 and 0.31 after 24 hours). Lower growth rate of the cells in biofilm was shown, with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain. Compared with the control group observed by transmission electrmicroscope, the cell density of biofilm air face was lower than that of agar face, with more cell debris.

CONCLUSIONSErythromycin could penetrate to the Staphylococcus epidermidis biofilm, but could not kill the cells thoroughly. The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

Acridine Orange ; Anti-Bacterial Agents ; pharmacokinetics ; Biofilms ; DNA, Bacterial ; analysis ; Erythromycin ; pharmacokinetics ; pharmacology ; Microscopy, Electron, Transmission ; RNA, Bacterial ; analysis ; Staphylococcus epidermidis ; drug effects ; metabolism

OBJECTIVETo evaluate the diagnostic efficiency of colloidal gold and dot ELISA rapid tests in clinical screening of influenza A virus.

METHODSThe 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.

RESULTSAmong 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).

CONCLUSIONDot ELISA is better than colloid gold in influenza A virus detection and shows great prospect in clinical screening.

Enzyme-Linked Immunosorbent Assay ; Gold Colloid ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; diagnosis ; virology ; Real-Time Polymerase Chain Reaction ; Sensitivity and Specificity