1.Analysis of distribution and drug resistance of pathogenic bacteria in burn wards
Zhengpeng XU ; Su WANG ; Lizhong HAN ; Wenkui WANG
Journal of Shanghai Jiaotong University(Medical Science) 2017;37(4):527-531
Objective·To analyze changes in the type distribution and drug resistance of pathogenic bacteria isolated from burn wards and to provide evidence for rational use of antibiotics, reduction of drug-resistant isolates, and hospital infection control. Methods·Isolates from burn patients were collected from January 2011 to December 2014. Statistical analysis of infection sources, type distribution, and changes in resistance rates of main pathogens during the four year period was performed. Results·A total of 2399 isolates were collected, including 1286 (53.61%) gram-negative bacilli (G-b), 1088 (45.35%) gram-positive cocci (G+c), and 25 (1.04%) fungi. The most common G-b pathogens were Pseudomonas aeruginosa (447, 34.76%) and Acinetobacter baumannii (369, 28.69%). The most common G+c pathogen and fungus were Staphylococcus aureus (489, 44.94%) and Candida albicans (8, 33.33%), respectively. In the last two years, the detection rates of S.aureus and A.baumannii were significantly lower and the detection rate of P.aeruginosa was significantly higher than those in the first two years (P<0.05). P.aeruginosa and A.baumannii showed high resistance (>80%) to the third and fourth generation cephalosporins, carbapenems, aminoglycosides and quinolones, but the changes were not statistically significant (P>0.05). S.aureus was only highly resistant to penicillin (97.58%) and was 100% susceptible to vancomycin. Its resistance rates toward cefazolin, ampicillin/sulbactam, gentamicin, levofloxacin, and rifampin decreased significantly (P<0.05). The detection rate of methicillin-resistant S. aureus (MRSA) dropped from 72.28% to 63.00%. Conclusion·Many types of drug resistant bacteria were detected in burn wards. The drug resistance problem was serious. Improving management and rational use of antibiotics can reduce the occurrence of drug-resistant bacteria and increase the efficacy of clinical anti-infective treatment and nosocomial infection control.
2.Distribution and antimicrobial resistance of pathogens isolated from hospi-talized patients with bloodstream infections
Shengyuan ZHAO ; Shuzhen XIAO ; Lizhong HAN ; Chenrong MI ; Yuxing NI
Chinese Journal of Infection Control 2014;(5):266-270
Objective To investigate the species and drug resistance of pathogens causing bloodstream infections in hospitalized patients,and provide scientific evidence for antimicrobial use and control of healthcare-associated blood-stream infection.Methods From January 1 to December 31,2012,16 428 blood specimens were performed blood culture,pathogens were isolated and performed antimicrobial susceptibility testing.Results Of 16 428 blood speci-mens from 5 546 patients,384 (6.92%)were positive for blood culture,398 pathogenic isolates were detected,of which gram-positive bacteria,gram-negative bacteria,and fungi accounted for 23.62% (n=94),68.34% (n=272),and 8.04% (n=32)respectively,positive rate of blood culture were highest in 61-80 age group(8.26%), the top five departments of positive rate of blood culture were departments of burn,traditional Chinese medicine, cardiac intensive care unit,transplantation and traumatology;gram-positive cocci were highly susceptible to vanco-mycin,teicoplanin and linezolid,one Enterococcus faecium strain was found to be resistant to vancomycin;Among gram-negative bacilli,Enterobacteriaceae were highly susceptible to amikacin and carbapenems;drug resistance rates of Acinetobacterbaumannii and Pseudomonasaeruginosa to carbapenems was 70.97% and 35.90% respective-ly.Conclusion Gram-negative bacteria are the major pathogens causing bloodstream infection,positive rate of blood culture of elderly people is high.It is necessary to conduct regular surveillance on distribution and drug resistance of pathogens.
3.The influence of platelet rich plasma gel applied to adipose-derived stem cells repair soft tissue wounds
Huaiwei LIAO ; Chao HAN ; Lizhong LIU ; Minjun CAO
Chongqing Medicine 2013;(32):3859-3862
Objective To explore the role of ADSCs and PRP in soft tissue defect repairing .Methods Harvest adipose tissue from inguinalis fat pad of SD rats ,isolation ,culture ,and identification the ADSCs through three differentiation method .Take 30 male SD rats about 6-7 weeks old randomly .Randomly selected 12 rats been take blood from heart .Preparation the PRP with modi-fied appel method .To count platelet of whole blood and PRP under microscope .Take the remaining rats .Divided the rat into 3 groups(n=6 in each group) randomly ,of which group A treatment with ADSCs and PRP ;Group B treatment with ADSCs ;Group C treatment whit PRP .Selected one side of skin defect wound for test randomly and the relative side skin defect is for control ,Handle all of the control wound to group D ;Observe the grow th of granulation tissue on the wound surface ;observe the inflammatory sur-rounding and the degree about epithelial .statistical analysis and record the wound size ,and calculation the shrinkage rate of wound in different periods .Record the time of completely healing time .Histologic observation of the wound healing tissue .Results Plate-let counting showed platelet of PRP is 5 .21 times than whole blood .The wound completely healed time :group A (18 .25 ± 1 .44 ) days ,group B(19 .13 ± 1 .28)days ,group C(19 .72 ± 0 .87)days ,group D(22 .31 ± 1 .65) days ,The time of each treatment group and control group was significantly obvious(P< 0 .05) .At 3 ,7 ,11 and 15 days after experimental treatment ,compared with the control group the experiment group of wound contraction rate was significantly obvious (P<0 .05) .Conclusion Application of AD-SCs with PRP can enhance the quality and shorten the wound healing time than used them alone .
4.ESBLs Produced by Enterobacter cloacae
Deping DONG ; Lizhong HAN ; Shilin CHEN ; Yuxing NI
Chinese Journal of Nosocomiology 2006;0(03):-
OBJECTIVE To investigate the ESBLs produced by clinical strains of Enterobacter cloacae.METHODS Production of ESBLs was identified with modification of the double-disk test(MDDT).Eight kinds of primers(CTXM,CTXM-1,CTX-M-2,CTX-M-9,SHV,TEM,VEB,and PER)were used for the PCR amplification.Gene clone and DNA sequencing were performed then.RESULTS The result of MDDT was positive,amplicons were gained by PCR amplification with CTXM-1.DNA sequencing of amplicons of this strain revealed ESBLs of CTX-M-3.CONCLUSIONS ESBLs are the important reason for E.cloacae resisting to the third-generation cephalosporins.
5.Distribution and Antibiotic Resistance Analysis of 1275 Pathogens Isolated from Urinary Tract Infection
Chuanling ZHANG ; Lizhong HAN ; Yuxing NI ; Tiantian LU
Chinese Journal of Nosocomiology 2005;0(11):-
OBJECTIVE To investigate the distribution and antibiotic susceptibility of pathogens causing urinary infection,for the guide of rational use of antimicrobial agents in clinic. METHODS The bacteria isolated from the middle segment urine sample were identified by ATB system,and K-B method was used to study the antimicrobial resistance.The data were analyzed by WHONET 5.3. RESULTS Escherichia coli was one of the most common bacteria in the urinary tract infection(57.6%),and then were Enterococcus(14.4%).The results of antibiotic susceptibility test in vitro showed the susceptibility rate of Enterobacteriaceae and Acinetobacter baumannii to imipenem,was 100.0%,but the resistance rate of Pseudomonas aeruginosa was 13.6%.Gram-positive cocci were sensitive to glycopeptide antibiotics and linezolid. CONCLUSIONS Clinician should pay attention to the kinds of pathogenic bacteria causing urinary tract infection and their susceptibility to clinically common used antibiotics for reasonable use of drugs.
6.Leukocidin prevalence and molecular epidemiology of methicillin-resistant Staphy-lococcus aureus
Hong ZHANG ; Wanhua LI ; Qin CAI ; Lizhong HAN ; Yibo ZHANG
Chinese Journal of Infection and Chemotherapy 2009;09(4):248-251
Objective Methicillin-resistant Staphylococcus aureus (MRSA) is a growing public health concern that has been associated with pediatric fatalities. This study investigated the genotypes of staphylococcal cassette chromosomal mec (SCCmec) and Panton-Valentine Leukocidin (PVL) in MRSA strains isolated from Shanghai Children's Hospital by PCR. Methods A total of 30 strains of MRSA were isolated from various clinical specimens from October 2005 to June 2006. The antimicrobial susceptibility was measured by agar diffusion method. SCCmec typing was conducted using a novel multiplex PCR assay allowing for concomitant detection of methicillin resistance (mecA gene) to facilitate detection and classification of all currently described SCCmec typesⅠ, Ⅱ, Ⅲ, Ⅳa, b, c, d andⅤ. PVL gene was also determined by PCR. Results mecA gene was positive in all the strains. SCCmecⅡ was identified in 6(20.0%) isolates, SCCmecⅢ in 15(50.0%) isolates, SCCmecⅤ in 2 and SCCmecⅣa in 1 isolate. Six MRSA strains were non-typeable. The isolates with SCCmecⅡ or SCCmecⅢ were resistant to multiple antibiotics. The strains harboring SCCmecⅣa or SCCmecⅤwere susceptible to all antibiotics except β-lactams. Eleven (36.7%) isolates were PVL positive. The genotypes and subgenotypes of staphylococcal chromosomal cassette mec of eleven PVL-positive MRSA were SCCmecⅡ(1 isolates), SCCmecⅢ (5 isolates), SCCmecⅣa (1 isolate), SCCmecⅤ (2 iso-Lates) non-typeable (2 isolates). Conclusions SCCmecⅡ and SCCmecⅢ are the major genotypes of MRSA in our hospital. These isolates are multi-resistant to antibiotics. The prevalence of PVL gene is higher in SCCmecⅡ- or SCCmeⅢ-positive MRSA. The isolates with SCCmecⅡ or SCCmecⅢ were resistant to multiple antibiotics.
7.Relationship between antibiotic use and antimicrobial resistance in Acinetobacter baumannii
Shuzhen XIAO ; Guiting XU ; Jie FANG ; Haiqing CHU ; Lizhong HAN ; Yuxing NI
Chinese Journal of Infection and Chemotherapy 2013;(6):446-449
Objective To investigate the relationship between antibiotic use and antimicrobial resistance in Acinetobacter bau-mannii for rational use of antibiotics.Methods Antibiotic use density (AUD)of common antibiotics in hospitalized patients were collected in a tertiary hospital between 2006 and 2010.Clinical isolates of A.baumannii from those patients were collect-ed.The resistance to common antimicrobial agents were tested by disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI,2012)guidelines.Relationship between antibiotic use and antimicrobial resistance in A.baumannii was analysed by SPSS 16.0.Results The resistant rates of A.baumannii isolated from inpatients were high.Consumption of cephalosporins and quinolones were large.There was a positive correlation between the resistant rate of A.baumannii to imi-penem and AUD of carbapenems (r=0.975,P <0.05).The resistant rate of A.baumannii to meropenem showed significantly positive relation to AUD of carbapenems (r= 0.975,P <0.05).Resistant rates of aminoglycosides,quinolones,cephalospo-rins and beta-lactamase inhibitors was not correlated to AUD of those antibiotics.Conclusions We should pay more attention to the high prevalence of resistant A.baumannnii strains.Application of imipenem and meropenem should be strictly controlled.Amikacin and beta-lactamase inhibitors are better choice for empirical antibiotic therapy in the treatment of infections caused by A. baumannii.
8.The evolution and dissemination of macrolide-resistance Streptococcus pneumoniae in Shanghai
Wenjuan WU ; Xiaofei JIANG ; Hong ZHANG ; Fupin HU ; Lizhong HAN ; Demei ZHU ; Yuxing NI
Chinese Journal of Laboratory Medicine 2008;31(10):1124-1127
Objective To determine the genetic background and evolutional route of macrolideresistance Streptococcus pneumoniae(MRSP)strains in Shanghai.Methods Forty-seven MRSP clinical isolates were genotyped by pulse field gel electrophoresis(PFGE)to detect the donal relationship of therm.Serotyping and muhilocus sequence typing(MIST)on 6 multi-resistant strains wag used to investigate the evolutional relationship between serum types and international epidemic strain among MRSP strains in Shanghai.Results There were 2 epidemical clones(type A 45%,type B 17%)in MRSP clinical isolates containing both the ermB and the mefE genes in Shanghai.MIST analysis showed that all 6 multi-resistant strains whose PFGE pattern was A type belonging to Asia clonal complex-CC236(Taiwan19F-14 clone).There was a novel ST-ST2116,which might derived from CC236 due to the recombination with alldic change.Conclusion,The high prevalence of erythromycin-resistant Streptococcus pneumoniae containing both the ermB and the mere genes in Shanghai is partly due to the clonal spread of a few mtdtidrng-resistant clones.
9.Evaluation on the capability of CHROMagar orientation medium combined with simple biochemical tests for identificaction of common oxidase-negtive gram-negative bacilli
Shengyuan ZHAO ; Yiwen CHEN ; Linhui LI ; Chenlu XIAO ; Jie LI ; Chenrong MI ; Lizhong HAN ; Yuxing NI
Chinese Journal of Microbiology and Immunology 2013;(7):525-530
Objective To evaluate the practicability of CHROMagar orientation medium combined with simple biochemical tests for identification of common oxidase-negtive gram-negative bacilli.Methods The CHROMagar orientation medium was used together with biochemical tests including indole test , ornithine decarboxylase test and lysine decarboxylase test for identification of common oxidase -negtive gram-negative bacilli.The sensitivity, specificity, likelihood ratio, Youden index and Kappa value of the diagnostic assays were evaluated .McNemar test was performed to evaluate facticity, accuracy and cost of the method in com-parison with the Vitek-2 system as reference method .Results The identification of oxidase-negtive gram-negative bacilli from 318 bacterial strains showed that the sensitivities and specificities of CHROMagar orien-tation mediumm in combination with simple biochemical tests to Serratia marcescens, Stenotrophomonas mal-tophilia and Acinetobacter baumannii reached 100%, and for Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoiae were above 90%.The specificities for identification of Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Proteus mirabilis were all above 90%, but the sensitivities were around 75%-90%.Kappa values of the assays were above 0.85, howerer, which was only 0.5947 for Citrobacter freundii.McNemar test showed that all P values were above 0.05, and cost of the assays was reduced by 90%.Conclusion CHROMagar orientation medium in combination with simple biochemical tests is a cost-effective assay for identification of common oxidase-negtive gram-negative bacilli .
10.ESBLs′ Genotypes of Escherichia coli and Klebsiella pneumoniae
Huihong CHEN ; Lizhong HAN ; Sufei YU ; Bo SHEN ; Yiman WANG ; Jun ZHOU
Chinese Journal of Nosocomiology 2006;0(02):-
OBJECTIVE To investigate the ESBLs ′ genotypes and the resistance of Escherichia coli and Klebsiella pneumoniae in Taizhou Hospital of Zhejiang Province.METHODS We collected 30 strains of E.coli and K.pneumoniae expressing ESBLs,then analyzed their encoding genotypes of TEM,SHV,PER,VEB and CTX genes by PCR and DNA sequencing technology separately.RESULTS There were 26 strains expressing blaCTS-M gene among 30 strains,in which 16 strains belonged to blaCTS-M-9 subgroup genotype,8 strains to blaCTX-M-1,7 strains to blaCTX-M-2,4 strains to blaCTX-M-1 as well as blaCTX-M-2,1 strain to blaCTX-M-2 as well as blaCTX-M-9 and 1 strain belonged to blaCTX-M-1 as well as blaCTX-M-9.CONCLUSIONS The prevalent clinical genotype of E.coli and K.pneumoniae is blaCTX-M-9.