Hypervirulent Klebsiella pneumoniae ( hvKP) mainly infects healthy people and causes serious infections, such as liver abscess, meningitis, necrotizing fasciitis, endophthalmitis and severe pneu-monia. Studies have shown that hvKP is more virulent than classic Klebsiella pneumoniae characterized by ex-pressing more capsular polysaccharide and carrying the virulence factors including magA, rmpA and iron ac-quisition molecules. The greater survival and anti-phagocytosis abilities of hvKP strains contribute to the spread and metastasis of hvKP infection. This review describes the virulence factors, colonization and infec-tion of hvKP as well as the host immunity to hvKP.

OBJECTIVE To construct two-hybrid genomic library of Rhodococcus equi,and study the pathogenic mechanism of R.equi.METHODS The genomic DNA of R.equi was partially digested and cloned into AD vector of two-hybrid system,the number of independent clone and the size of insert fragment were detected as the quality index of the library.RESULTS The independent clone of the library was 1?106 and the average size of insert fragment was 2.3 kb.CONCLUSIONS The pathogenic mechanism of R.equi is not clear and it is very important for this study to construct two-hybrid genomic library.

Objective To survey the bacterial species and drug resistance of bacteria isolated from blood, urine and other samples in 12 military hospitals located at different areas in China. Methods A total of 1099 non-repetitive bacterial isolates were collected from 12 military hospitals and sent to the General Hospital of PLA for re-identification and drug susceptibility test. The minimal inhibitory concentrations (MICs) of antimicrobial agents were determined by agar dilution method. The results were evaluated according to the standards of CLSI (2007) and analyzed by WHONET 5.4 software. ESBLs, AmpC ?-lactamases were detected using the confirmatory test and APB discs method, respectively. Results Gram positive cocci and gram negative bacilli constituted 39.7% and 60.3% of 1099 clinical isolates respectively. Methicillin-resistant Staphylococcus aureus (MRSA) accounted for 62%, and methicillin-resistant coagulase negative Staphylococcus (MRSCN) accounted for 92%. ESBLs-producing and AmpC-producing strains of Escherichia coli accounted for 51.1% and 11.3%, respectively, and of Klebsiella pneumoniae accounted for 45.1% and 16.2%, respectively. As to caftazidime, amikacin, cefotaxime, cefoxitin and levofloxacin, the resistance rate in Escherichia coli (E. coli) and Klebsiella pneumoniae isolated from blood was lower than that isolated from urine. However, as to meropenem, ceftazidime, polymyxin and minocyclin, the resistance rate in Pseudomonas aeruginosa and Acinetobacter spp isolated from blood was higher than that isolated from urine. Conclusion MRSA, MRSCN, and producers of ESBLs and AmpC ?-lactamases are common in military hospitals. Resistance pattern of bacteria from blood differs from that of bacteria from urine. It is necessary for military hospitals to take the bacterial distribution and resistance levels to antimicrobial agents under surveillance in order to guide the proper use of antibiotics for military doctors, and the results may serve as guidelines in the use of antimicrobial agents in war time.

Objective To study 8 isolates of multiple antibiotic-resistant Klebsiella oxytoca in 8 different patients from one surgical ward. Methods Susceptibility test, extended-spectrum ?-lactamases (ESBLs) screening methods and some molecular biological methods were performed. Results 8 isolates of Klebsiella oxytoca were verified as closely related homologous CTX-M-3-producing strains. Conclusions The little outbreak was caused by 8 closely related homologous strains in one ward.

Objective To study the function of aminophenylboronic acid(APB)and clavulanate(CA)for detecting ESBLs in Enterobacter cloacae.Methods The phenotype of ESBLs of 61 Enterobacter cloacae isolates was detected with adding single beta-lactamase inhibitor CA to ceftazidime(CAZ)and cefotaxime(CTX),and double beta-lactamase inhibitors CA/APB to ceftazidime(CAZ)and cefotaxime(CTX)respectively.PCR was used to detect ESBLs genes of 61 Enterobacter cloacae isolates.The results of the enzymatic inhibitor potentiation test and PCR were compared and analyzed.Results With adding single enzymatic inhibitor CA to CAZ,28 isolates of Enterobacter cloacae producing ESBLs were detected,while 14 isolates were detected with adding CA to CTX.With adding double enzymatic inhibitors CA/APB to CAZ,28 isolates of Enterobacter cloacae producing ESBLs were detected,while 44 isolates were detected with adding CA/APB to CTX.By PCR positive ESBLs genes were detected in 47 isolates of Enterobacter cloacaes.Conclusions The potentiation test with double beta-lactamase inhibtion can be used to detect ESBLs in Enterobacter cloacae.

Objective To study the education of medical mycology for undergraduates of medical laboratory specialty and provide a basis for teaching reformation.Method Setting of mycology related courses of medical mycology for undergraduates in 5 medical schools and 85 inspection and technical personnel's detection of fungi in 81 hospitals were investigated through consultation and questionnaire survey.Results More than 140 class hours for medical mycology were arranged in 5 schools,but as to medical mycology,22 class hours in 1 school and less than 10 class hours in 4 schools,the minimum class hours were 5.Although various numbers of Candida and filamentous fungi could be isolated in hospitals investigated,more than half laboratory workers could not identify penicillium,thermally dimorphic fungi,Zygomycetes and Dematiaceous fungi.Conclusion Education on medical mycology for medical laboratory specialty undergraduates is insufficient and the corresponding teaching lacks such content as medically important pathogenic fungi detection methods and identification characteristics.The hospital technical personnel's fungal identification ability cannot meet the situation of increasing fungal infection involved in clinical medicine,so it is necessary to carry out teaching reformation of medical mycology for undergraduates in laboratory medicine,including adding class hours,increasing course contents and so on.

Objective To investigate the resistance of Staphylococcus to erythromycin and clindamycin and detect the percentage and gene for inducible resistance. Methods Disk diffusion method was used to test the resistance phenotype of Staphylococcus aureus and coagulase-negative staphylococcus according to the standards of NCCLS. The inducible resistance of erythromycin to clindamycin was checked by D-test and the gene for erythromycin ribosome methylase was detected by polymerase chain reaction.Results Co-resistance to erythromycin and clindamycin accounted for 62.7% and 54.8% in MRSA and MRCNS respectively. D-test positive rate was 17.7% among all Staphylococcus tested. The rate of inducible resistance to clindamycin (D-test positive) was 67.6% and 45.3% in Staphylococcus aureus and coagulase-negative Staphylococcus which possessed erythromycin resistant and clindamycin sensitive by individual disk diffusion test. The predominant gene for inducible resistance was ermC with the percentage of 74.5%.Conclusion The inducible resistance of erythromycin to clindamycin in Staphylococcus should be checked by D-test in clinical microbiology laboratory in order to help physicians to select MLSB antimicrobial agents correctly.

Objective To study the detection characteristics of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococcus.Methods Disks with 1 ?g of oxacillin and 30 ?g of cefoxitin were used to detect the inhibition zone of staphylococcus aureus and coagulase-negative staphylococcus at both 35℃ and 30℃ according to the method and breakpoint recommended by CLSI.The agar surface of oxacillin plate with sodium chloride was spotted.mecA gene was amplified by PCR.Results For detection of MRSA, disks of oxacillin and cefoxitin at 30℃ have the same sensitivity of 100%, however, the sensitivity of cefoxitin( 94.7%) is a little higher than that of oxacillin (93.3%) at 35℃. For detection of MRCNS, the sensitivity of 100% can be obtained by disks of both oxacillin and cefoxitin at both 30℃ and 35℃.The sensitivity and specificity of oxacillin plate with sodium chloride are the same as those of disks of oxacillin and cefoxitin at 30℃ for detection of MRSA, its sensitivity is lower than that of disks for detection of MRCNS.Conclusion The detection of methicillin-resistant Staphylococcus can be improved by the use of cefoxitin disk.

OBJECTIVE To investigate the prevalence and resistance of extended spectram ?-lactamases(ESBLs) producers in Escherichia coli and Klebsiella pneumoniae.METHODS ESBLs producing strains were screened by double disk test and confirmed by the NCCLS confirmatory test.Susceptibility test to antimicrobial agents was performed by disk diffusion method and analyzed by WHONET 5.3 and Excel.RESULTS The isolated ratio of ESBLs producing E.coli and K.pneumoniae increased from 14% and 15% in 1999 to 30.1% and 30.4% in 2002.Bacteremia caused by the two kinds of ESBLs producers accounted for 30.2% and 30.4%,respectively.ESBLs producing K.pneumoniae and(ESBLs) producing E.coli were 19.8% and 14.0% for outpatient and 26.6% and 31.6% for inpatient.The resistance of(E.coli) to 17 kinds of agents was similar,no matter it was isolated from blood,urine or sputum.Susceptibility of(ESBLs) producing E.coli and K.pneumoniae in urine to cefoperazone/sulbactam,and piperacillin/tazobactam were 85% and 65.2%,66.6% and 29.4%,although to other 15 agents there were no difference.None of the(isolates) showed resistance to imipenem.CONCLUSIONS There is an increasing trend of ESBLs producing E.coli and K.pneumoniae(isolated) from various kinds of specimens and from different wards.It is important for clinical physicians to understand the distribution and the resistance characteristics of ESBLs producing E.coli and(K.pneumoniae) to antibiotics.

OBJECTIVE To study the prevalance and resistance characteristics of clinical isolates of Enterobacter cloacae.METHODS Clinical isolates of E.cloacae were studied by K-B methods,and the data of MIC were(analyzed ) by WHONET 5.3 software.RESULTS Totally 416 clinical isolates of E.cloacae isolated from 2000 to 2004 were studied and they were mainly isolated from department of respiration,surgical ICU and department of(neurology) and their rate was 25.2%,9.6%,and 8.6%,respectively.The E.cloacae strain was(resistant) to ciprofloxacin,amikacin and most of penicillins,cephalosporins and ?-lactams combined with the(?-lactamase) inhibitors.It was susceptible to cefepime,imipenem and etrapenem.CONCLUSIONS The E.cloacae is resistant to many commonly used antibiotics in clinics and it is important to control antibiotic(resistance) by using antibiotics reasonably.