The term "superbugs" refers to microbes with resistance to almost all antibiotics specifically recommended for the treatment. The superbugs disseminating worldwide included methicillinresistant Staphylococcus aureus ; vancomycin-resistant Staphylococcus aureus ; vancomycin-resistant Enterococcus ;carbapenem-resistant Gram-negative bacillus. Due to abuse of antibiotics, novel "superbug"emerged gradually, which demands optimizing antibiotic use, reinforcing surveillance of "superbugs" as well as nosocomial infection control.

The key to improve the clinic antimicrobial therapy results is correct diagnosis of infection,pathogens and antibiotic resistance.To deal with increasingly complex pathogens and drug resistance,the clinic and lab should cooperate and communicate as often as possible,improve the level of pathogen diagnosis,interpretate of the microbiological examination report correctly and explore the mechanisms and treatment of antimicrobial resistant pathogens.Besides,they should make full use of the inflammatory markers to further enhance anti-infective levels.

Community-acquired methicillin-resistant Staphylococcus aureus ( CA-MRSA ) has been increasingly frequently isolated from patients worldwide, and is an emerging threat to public health.CA-MRSA strains differ from hospital-acquired MRSA strains in their epidemiologies, clinical features and genetic backgrounds, and the predominant CA-MRSA strains vary between geographic settings.This paper reviews literatures on the definition, epidemiology, clinical manifestations, treatment and virulent factors of CA-MRSA or CA-MRSA infection, and points out that we should further promote studies on epidemiology, molecular genetic properties of CA-MRSA and clinical management of CA-MRSA infection.

Objective To analyse the encoding gene sequence of extended spectrum ? lactamase produced by Klebsiella pneumoniae E95 strain in Zhejiang Province and identify its ESBLs subtype. Methods The gene of ESBLs produced by E95 strain was amplified by PCR. The purified PCR product was cloned into pGEM Teasy vector and then sequenced by Sanger's dideoxy chain termination composition method. Results The encoded gene of ESBLs was identified as SHV by PCR. Its PCR product had 812 nucleotides. It had the same gene sequence as the gene encoding SHV 12 discovered in Swiss. Conclusions The ESBLs produced by Klebsiella pneumoniae E95 strain isolated from a patient in Zhejiang Province is SHV 12.

Objectives To investigate the properties and distributions of ampC gene among different drug-resistant strains of Serratia marcescens,and the relationship of control gene ampR with AmpC enzymes′ expressions.Methods According to the results of inducting experiment with 1/2 MIC of beta-lactam antibiotics (CTX),three-dimensional testing and isoelectric focusing electrophoresis testing,143 strains of S.marcescens were classified into three groups:including induction group, continuous low-production group and hyperproduction group. In each group, the sequences of ampC and ampR genes were amplified using the method of PCR. The products of PCR were analyzed. The plasmid-mediated beta-lactamases were detected using the method of conjugation experiment.Results Among 143 strains of S.marcescens, the continuous low -production strains, induction strains and hyperproduction strains were 14,103,and 18, respectively.125 and 99 strains were ampC and ampR gene positive, respectively.The detection rate of ampR in hyperproduction group was lower than other groups.5 sites of ampC genes and 4 sites in the Open Reading Frame (ORF) of ampR gene were easily mutated in 5 induction strains and 2 hyperproduction strains.Conclusions The production of inducing drug-resistance of some S.marcescens might be related to mutation of ampC gene encoding AmpC beta-lactamases and the ORF mutation in ampR. The continuous hyperproduction drug-resistance had something to do with deletion mutation in ampR in segmental hyperproduction strains.The plasmid-mediated AmpC enzymes hadn′t been found in S.marcescens.

Objective To construct the mice pneumonia model with imipenem-resistant Acinetobacter baumannii and provide experimental model in anti-pan-resistant Acinetobacter baumannii therapy study. Methods A total number of 120 4-week-old BALB/C male mice were randomly selected and divided into three groups including micro-intratracheal injection, ultrasonic atomizing and nasal dripping. The mice were treated with methotrexate to induce hypo-immunity in every group. These BALB/C mice of normal immunity and hypo-immunity were infected through Imipenem-resistant Acinetobacter baumannii by microintratracheal injection, ultrasonic atomizing and nasal dripping, respectively. The morbidity, mortality,bacterial clearance rate and histopathology in lung were determined. Results The morbidities of BALB/C mice with hypo-immunity infected by micro-intratracheal injection and ultrasonic atomizing achieved 100%(30/30), while the mortalities were 100% (10/10) and 33.3% (3/10), respectively. Mice in two groups above displayed the influx of neutrophils, lymphocytes and macrophages in the peri-bronchial and alveolar interstitial space 12-24 h after pulmonary infection. In addtion, the mice in micro-intratracheal injection group displayed coUapse of partial alveolar walls, formation of abscesses and bacterial colonies in alveoli. While the lung pathology in mice of ultrasonic atomizing group was characterized by cell degeneration in some regions in the lungs, slight relaxation, congestion in alveolar wall vessels and normal of bronchial and alveolar tissue 24 h after inoculation. Degeneration in peri-tracheal and peri-bronchial areas was observed 24-48 h after inoculation, along with highly expanded pulmonary blood vessels and edems. The inflammation was reduced at 48 hours. There was no obvious pulmonary infection in BALB/C mice with hypo-immunity by nasal dripping with mortality of 0% (0/10) and no significant histopathologic change in lungs. Conclusions BALB/C mice with hypo-immunity pneumonia model with Imipenem-resistant Acinetobacter baumannii can be conducted by micro-intratracheal injection or ultrasonic atomizing, but the latter has the advantages of high-productivity, easy-operation, low-cost, time-saving and usefulness. Mice with normal immunity are not susceptible to imipenem-resistant Acinetobacter baumannii.

Purpose　To investigate the role of urokinase plasminogen activator (uPA),uPA receptor (uPAR),tissue type plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI-1) in the invasiveness of human breast cancer cells.　Methods　Three human breast cancer cell lines with different invasive ability were taken as research targets.RT-PCR and milk plates methods were used to detect the expression of uPA system members and the PA activities,respectively.Modified Boyden's chamber model was employed to detect the invasive ability of cancer cell.　Results　MDA-MB-231 could express high level of uPA,uPAR,PAI-1 and low level of tPA.MDA-MB-435 could express lower level of uPA and hight level of tPA,but no PAI-1 and uPAR were detected.MCF-7 could express lower level of uPAR and high level of PAI-1,but no uPA and tPA were detected.MDA-MB-231 cells showed the highest total PA and uPA activity.MDA-MB-435 cells also showed high total PA activity,but almost all the activity owed to tPA.MCF-7 showed almost no PA activity.Correlated with their PA activities,MDA-MB-231 was found the most invasive in vitro,followed by MDA-MB-435,and MCF-7 almost had no invasive ability.The antibodies against uPA and uPAR were significantly effective in reducing the matrigel invasiveness of MDA-MB-231 by approximately 83.1% and 43.9% respectively (P<0.05).　Conclusions　Co-expression of uPA,uPAR and PAI-1 in human breast cancer highly correlates with the invasiveness in vitro.

Aim To obtain the encoding gene sequences of TEM-type ?-lactamases produced by 4-strain Klebsiella pneumoniae in Zhejian g Province, identify their genotypes and study some properties of these TEM-typ e ?-lactamases.Methods The encoding genes of TEM-type ?-la ctamases produced by 4 isolates were amplified by PCR. The purified PCR products were ligated with pGEM-T easy vectors, expressed in E. coli DH 5?, and sequenced by Sanger's dideoxy chain termin ation composition method. Compared with anino acid sequences in the GenBank,TEM -types of the ?-lactamases was determined. The genes of TEM ?-lactamases were ligated with pET-28 c vector to express recombinant proteins in E. coli DH 5?. Plasmids were extracted from the p ronucleus expression strains and PCR was performed to determine whether the pron ucleus expression was successful or not. Their phenotypes were determined by ESB Ls phenotype affirmative test. The isoelectric points (pIs) of the recombinant p roteins were determined by isoelectric focus. Conjugation test was performed to determine whether their genes existed in plasmid or chromosome. Results The encoding genes of ?-lactamases were determined as TEM by PCR. It s PCR product had 1 009 nucleotides. The pI of the novel TEM ?-lactamase was 5.4. The enzyme was determined as non-ESBLs by ESBLs phenotype affirmative tes t.Transconjugants were successfully selected from the paternal producers in conj ugation tests. The TEM-type ?-lactamase produced by 4 strains was determined as TEM-105(AF516720) by GenBank. Conclusion The ?-lactamase produced by 4-strain K. pneumoniae from 4 patients in Zhejiang Province was TEM-105. It was the first report of TEM-105 type ?-lactamase produced by 4-st ain K. pneumoniae from China in the world.

Objective To study the epidemiology and genotypes of extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli (EC) and Klebsiella pneumoniae (KP) that caused community-onset bloodstream infections (COBSI) in 9 county hospitals of Zhejiang Province.Methods This is a multi-center, prospective, observational study.The cases and isolates with COBSI caused by EC and KP were consecutively collected from 9 county hospitals in Zhejiang Province between 1st March 2014 and 30th April 2015.The double disk diffusion method was used to confirm the production of ESBL.The ESBL genotypes were determined by polymerase chain reaction(PCR) amplification and sequence analysis.Multi-locus Sequence Typing (MLST) was used to analyze the homology of ESBL-producing isolates.Minimal inhibitory concentration (MIC) of frequently used drugs for ESBL-producing isolates was determined by in-vitro antimicrobial susceptibility tests.Results During the study period, a total of 172 cases with COBSI were collected and 171 cases were eligible, among which 126 were caused by EC and 45 were caused by KP.The overall prevalence of ESBL was 34.5% (59/171),and the prevalence of ESBL-EC and-KP was 41.3% (52/126) and 15.6% (7/45), respectively.CTX-M-type ESBL accounted for 96.6% (57/59) of all the ESBLs-producing isolates, and the most common type was CTX-M-14 (27.1%, 16/59), followed by CTX-M-55 (22%, 13/59).MLST analyses revealed significant genetic diversity among ESBL-EC and-KP.The most prevalent ST of ESBL-EC was ST131 (23.1%).In addition to carbapenems, cefoperazone/sulbactam, piperacillin/tazobactam, moxalactam, amikacin and fosfomycin also showed good in-vitro activity against ESBL-EC and-KP.Conclusions The prevalence of ESBL in EC and KP is high in 9 county hospitals of Zhejiang Province, and the most common genotypes are CTX-M-14 and CTX-M-55.The detection rate of ESBL in EC is higher than in KP.It could be considered adequate empirical therapy according to the results of antimicrobial susceptibility tests.Carbapenems, cefoperazone/sulbactam, piperacillin/tazobactam, moxalactam, amikacin and fosfomycin have good in-vitro activity against ESBL-EC and-KP.

OBJECTIVE To identify the antibiotic resistance,homology and the carbapenemases determinants of imipenem-resistant strains of Acinetobacter baumannii isolated from elderly in the Zhejiang Hospital.METHODS All 142 strains of A.baumannii were isolated from Zhejiang Hospital through Jan 2005 to Jan 2007.K-B method was used to screen imipenem-resistant strains.The MICs of imipenem-resistant strains to 14 antimicrobial agents were determined by agar dilution method.The homology of these isolates was analyzed by pulse-field gel electrophoresis(PFGE).The coding genes of carbapenamases and the gene environments were investigated by PCR,clone,and sequencing.RESULTS Ninety-seven strains of imipenem-resistant A.baumannii were isolated from 142 strains.All of the strains of carbapenem resistant A.baumannii belonged to 4 epidemic PFGE-clones.Ninety carbapenem resistant strains contained OXA-23-like carbapenemase gene and 91 isolates were positive for OXA-51-like gene. OXA-23-like gene of 86 strains was just on the down-stream of insert sequence ISAba1.OXA-51-like gene of 6 strains had an ISAba1 sequence just on the up-stream.CONCLUSIONS All imipenem-resistant strains of A.baumannii are pan-resistant isolates.Clone dissemination is the most important style of strains spread.No OXA-24-like,OXA-58like,IMP-like,and VIM-like gene are detected.OXA-23-like and OXA-51-like gene are the most popular carbapenemases coding genes of these strains in the Zhejiang Hospital.ISAba1 has close relationship with OXA type carbapenemases genes in Zhejiang Hospital.