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Objective To compare the difference of three methods testing the antibiotic susceptibility of mucoid Pseudomonas aeruginosa in order to provide accurate and reliable antibiotic susceptibility result for clinic.Methods A total of 630 mucoid Pseudomonas aeruginosa were collected from Linyi People′s Hospital during January 2015 to December 2016.They mainly come from respiratory medicine and the most common specimen source was sputum.All specimens were examined in 2 h.The strains isolated from the same patient were discarded.Antibiotic susceptibility was tested by the automatic microorganism analyzer VITEK2 compact, E-test, which was reference method, and K-B disk.The results of three methods were analyzed and compared by χ2 test.Results The result of E-test showed that antibiotic sensitivity of 630 mucoid Pseudomonas aeruginosa was above 52.7% except for Cefepime (39.2%).The result of K-B disk was compared with E-test, the antibiotic sensitivity of mucoid Pseudomonas aeruginosa to imipenem (72.4% vs 52.7%) and amikacin (48.6% vs 71.1%)had significant difference (χ2=8.283 7 and 10.533 8, P<0.05).The result of VITEK2 compact showed that the antibiotic susceptibility of mucoid Pseudomonas aeruginosa to imipenem(70.8% vs 52.7%), cefepime(60.8% vs 39.2%), gentamicin (87.6% vs 74.1%)and levofloxacin(81.3% vs 65.4%) was significant higher than the result of E-test (χ2=6.935 2,9.331 2,5.885 6 and 6.466 5, P<0.05).For tobramycin, piperacillin/tazobactam and ciprofloxacin, the result of three methods is more consistent.Compared to VITEK2 compact, the consistency between K-B disk and E-test was higher.The rate of very major error and major error were between 0.0%-4.8% (Amikacin 12.2%) and minor error was 4.6%-20.3%.Conclusions The drug sensitivity of mucoid Pseudomonas aeruginosa is different between various methods.The result of K-B disk and E-test using blood MH is more reliable than VITEK2 compact.
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Objective To analyze the antibiotic resistance of Branhemella catarrhalis strains isolated from sputum specimens of patients with lower respiratory tract infections from Linyi, Shandong Province, and to explore the relationship between bro genotypes of the strains and their resistance to antibiotic agents.Methods Sputum specimens were colleted from the patients with lower respiratory tract infections in Linyi People ’ s Hospital from the January 2010 to December 2014.The specimens were inoculated into 4 different disks for bacterial isolation and cultivation.β-lactamase detection and drug sensitivity tests were performed, and PCR coupled with restriction endonuclease analysis was employed for bro genotyping.χ2 test was used to compare drug resistance of strains with different bro genotypes.Results A total of 497 Branhemella catarrhalis strains were isolated in five years, among which 221 strains were isolated in winter.All strains were sensitive to ertapenem and chloramphenicol, and the resistance rates to amoxicillin/clavulanate and cefaclor were low (≤2.8%).The strains were highly resistant to compound sulfamethoxazole, erythromycin and ampicillin (47.6%-89.8%), and there was a trend of increasing resistance rates with the year, but no statistically significant difference was observed ( P >0.05 ) .β-lactamases was positive in 412 strains (82.9%), and all of these strains were positive for bro gene, and the resistances to erythromycin, compound sulfamethoxazole, levofloxacin and ampicillin were higher in bro positive strains than those in bro negative strains (χ2 =12.16, 16.18, 8.41 and 200.00,P0.05 ).Conclusions Most of Branhemella catarrhalis clinical isolates are β-lactamase producing strains, and bro-1 is the most common genotype.Strains are highly sensitive to carbapenems, cephalosporins andβ-Lactamaseinhibitors, which can be recommended for the treatment of Branhemella catarrhalis-related respiratory tract infections.
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Objective To investigate the drug sensitivity of mucoid Pseudomonas aeruginosa to common antibiotics and the expression of β-lactamase-resistant phenotype.Methods The specimens were inoculated onto different disks to isolate and cultivate bacteria.The antibiotic susceptibility of mucoid Pseudomonas aeruginosa isolates was detected and judged by CLSI 2013.The detection of drug resistance was done by Kirby-Bauer (K-B) method and β lactamase-resistant phenotype was detected by E-test.SPSS19.0 was used to statistic data and x2 test was used to compare the antibiotic susceptibility between different groups.For all statistical test,a P values less than 0.05 was defined as statistically significant.Results The susceptibilities of mucoid Pseudomonas aeruginosa to the regular antibiotics were above 70％,of which the sensitivities to amikacin,to bramycin,gentamicin,imipenem and meropenem were higher than 90％.The positive rate of ampler class C β-lactamase (AmpC) was 28.3％ (56/198).The drug sensitivity of positive strains was lower than that of the negative strains,and the differentiation was significant to piperacillin-tazobactam,amikacin,ceftazidime,levofloxacin,ciprofloxacin and aztreonam (x2 =3.89-14.45,all P ＜0.05).The positive rate of extended spectrum β-lactamase(ESBLs) was 10.6％ (21/198).The drug sensitivity to ceftazidime and aztreonam of positive strains[42.9％ (9/21) and 57.1％ (12/21),respectively].It was lower than that of the negative strains [73.5％ (130/177) and 72.3％ (128/177)],x2 =5.06 and 19.24,both P ＜ 0.05.The difference of the other antibiotics was not significant(x2 =0.01-3.47,all P ＞0.05).The positive rate of metallo-β-lactamase (MBL) was 19.7％ (39/198),and the drug susceptibility of positive strains was lower than that of negative strains except gentamicin and aztreonam(x2 =4.07-15.99,all P ＜ 0.05).All the detected strains were Klebsiella pneumonia carbapenemase (KPC) negative.Conclusions The antibiotic susceptible rate of mucoid Pseudomonas aeruginosa was high,but some enzyme-produced strains were lower.The clinician should adjust medicine program by the results of laboratory.
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Objective To discuss the distributional characteristics and drug-resistance of Enterococcus species isolated from urine specimens.Methods 3096 middle-segment urine specimens were collected since January to December in 2011 for culture.The identification of pathogenic bacteria and antibiotics sensitivity tests were carried out with VITEK2-compact combined with GN,AST-GN13,GP,AST-GP67,and antibiotics sensitivity tested performed by K-B and E-test at the same time.The results were determined by CLSI 2011.Results 1248 of 3096 pathogenic bacteria were isolated (40.31％).549 strains of Escherichia coli were detected (43.99％) which was the most common and 159 strains of Enterococcus were detected (12.74％) which was the second most common.The Enterococcus detection rate in woman (15.02％)was higher than that in man (10.35％),in out-patients (15.54％) than the that in hospitalized patients (12.49％),and in the patients of non-surgical departments (13.65％) than those of surgical departments (11.38％).The Enterococcus was absolutely sensitive to tigecycline,and the sensitive rate to vancomycin and linezolid were over 90％.The antibiotics sensitivity was higher for Enterococcus faecalis than that for Enterococcus faecium,and in surgical departments than non-surgical departments.Conclusions The detection rate of Enterococcus in urinary tract infection patients is quite high and varied between sexes and departments.The difference of drug resistance between species is obvious,and the bacteria species should be identified in order to use the antibiotics reasonably to postpone the development of drug resistant strains.
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Objective To investigate the distribution and antibiotic susceptibilities of quantitatively cultivated bacteria from bronchoalveolar lavage fluid (BALF) samples. Methods Totally 312 BALF samples were streak inoculated to chocolate,blood and MAC plates with 10 μL annulus,and the bacterial colony ＞ 104 CFU/mL was considered pathogenic bacteria. The identification of pathogenic bacteria was carried out with Vitek 2-Compact,and Kirby-Bauer disc agar diffusion method,Etest and dilution method were used for antibiotics sensitivity test.Results Totally 216 (69.2％) strains of pathogenic bacteria were isolated.The major gram-negative strains were Pseudomonas aeruginosa,Acinetobacter baumannii,Klebsiella pneumoniae and Escherichia coli, and the major gram-positive strains were Staphylococcus aureus,Streptococcus pneumoniae and Staphylococcus epidermidis.The resistance rate of Pseudomonas aeruginosa to aztreonam was high,but lower than 30％ to piperacillin/tazobactam,imipenem,cefepime,ofloxacin,ceftazidime and amikacin.Staphylococcus aureus was highly resistant to erythromycin,benzylpenicillin and clindamycin,but it was sensitive to furadantin,vancomycin,quinupristin/dalfoprisdn,tigecycline and linezolid.Conclusion The positive rate of BALF cultivation is high,and the main pathogenic bacteria Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli are resistant to several commonly used antibiotics.
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OBJECTIVE To evaluate VITEK32 expert system(7.02) for detection and analysis of clinically important resistance phenotypes.METHODS A total of 508 known resistant phenotype clinial strains and 9 standards strains were tested by VITEK32 expert system(7.02) and antibiotic susceptibilities were determined by CLSI recommendation.RESULTS The correct phenotype was identified by the expert system in one or more choices for 312 from the 508(61.4%) isolates and standards.The resistant phenotypes for meticillin-susceptible,and resistant Staphylococcus spp,extended-spectrum ?-lactamases(ESBLs) producingEscherichia coli,Klebsiella spp,AmpC producing Enterobacter,cloacae,Serratia marcescens,and vancomycin-resistant Enterococcus faecalis were accurately identified by VITEK32 expert system,this expert system was not including ESBLs producing Proteus mirabilis.CONCLUSIONS VITEK32 expert system can be accurately identified most clinically important bacteria based on phenotype.The data of ESBLs Producing P.mirabilis should be included in the further work on expert system.
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Objective To compare the drug resistance of mucoid Pseudomonas aeFagillosa with that of non-mucoid.Methods All specimens isolated and cultured from patients were identified and the antibiotic sensitivity was tested by automatic microorganism analyzer VITEK-32,GNI+,GNS-448,E-teat and K-B.Results Drug resistant rates of mucoid Pseudomonas aeruginosa to imipenem.levofloxacin.meropenem,cefepime,cefoperazone/sulbactam,amikacin,gentamicin,piperacillin.tazobactam,ceftazidime and cefotaxime were 5.3%, 16.1%, 5.6%, 20.6%, 1.1%, 10.5%,26.9%,5.3%.31.5% and 60.2%,respectively.The drug resistant rates of mucoid Pseudomonas aeruginosa were lower than those of non-mucoid except to ceftazidime.Conclusion Compared with non-mucoid Pseudomonas aeruginosa,antibiotic resistance of mucoid Pseudomonas aeruginosa is weaker in vitro.
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OBJECTIVE To study the three-stage reports method using in clinical diagnosis of urinary system infections,and its value in order to fasten the clinical diagnosis and treatment.METHODS A total of 3349 urines specimens used a sequential three-stage reports method to prospectively evaluate and determine the validity of direct antimicrobial agent susceptibility testing by traditional method and VITEK-32.The first report was by Gram stained,the second report by criteria for initiating direct susceptibility testing,and third report was by standardized disk diffusion method and VITEK-32.RESULTS From 3349 samples the Gram negativstained smears were 746(22.3%),Gram negative bacilli were 1365(40.7%) the Gram positive cocci were 1036(31.0%) and the fungi were 202(6.0%).Escherichia coli rated the top one(55.7%),followed with Staphylococcus saprophyticus subsp saprophyticus 437(42.2%),Enterococcus faecalis 389(37.5%),Proteus,Klebsiella pneumoniae,Pseudomones aeroginose,and fungi.Enterobacteriaceae were showed increasing drug resistance trend,but still sensitive to imipenem(100.0%).G+-cocci were also showed serious drug resistance trend,but still sensitive to vancomycin(100.0%)(except E.faesium).CONCLUSIONS Three-stage method using in clinical diepnosis of urinary system infections is very important.Enterobacteriaceae are the main infectious bacteria in urinary system infection.Rational use of antibiotics should be carried out according to urine culture result.
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OBJECTIVE To evaluate the epidemiology of Pseudomonas aeruginosa(PAE) nosocomial infection and analyze ?-lactamase in multi-resistant strains and the enzymes produced by PAE,and to detect the correlation of the PAE in patients without nosocomial infection and from the hospital environment. METHODS The strains were identified by VITEK32,dynamically the strains of multi-resistant PAE were selected with K-B susceptibility method,then the three-dimensional method,and metal-?-lactamase determined by Etest.The isolated PAE strains from the patients or the environment were analyzed according to the detected time,environmental site as which part of the patient by randomly amplified polymorphism DNA(RAPD). RESULTS Totally 352 strains of PAE were isolated from 4246 specimens,the isolated rate was 8%.Study on the drugfast pathogens and RAPD pathogens indicated that there was no obvious correlation between the PAE from inpatients and from hospital environment. CONCLUSIONS It indicates that PAE exists in the burn ward extensively and hospital environment and exogenous infection are unimportant in nosocomial infection.The most of PAE are derived from the patients themselves.
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OBJECTIVE To develop a prospective evaluation strategy to detect the first 3 days of incubation of the clinically significant isolates. METHODS With blood culture positive sample by BacT/Alert~3D and direct identification and antimicrobial susceptibility tests by VITEK32 in clinics to compare with those obtained from cards(GPI,GPS-106,GNI+,GNS-506) incubated with standardized bacterial suspension obtained following subculture to chocolate agar plates and CHRMagarTM microbiology. RESULTS There were 3 strategy reports performed.The sensitivity was 99.18%,specificity was 99.62%,validity was 98.89%,incidence rate was 25.4%,positive predictive value was 99.18%,negative predictive value was 99.62%,positive likelihood ratio was 261,and negative likelihood rate was 0.008. CONCLUSIONS In the first 3 days of incubation,99.36% of the(1 701) clinically significant isolates were detected,suggesting that routine incubation for more than 3 days be not necessary for FA and FN bottles.These findings suggest that VITEK-32 cards inoculated directly from BacT/Alert culture positive bottles provide acceptable bacterial identification or susceptibility testing for Enterobacteriaceae and Staphylococcus,and decrease the time lapse between initial inoculation of blood culture and the reporting of the results.
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OBJECTIVE To determine the bacterial distribution and resistance status in urinary system infections among old patients with primary susceptibility testing on urine samples. METHODS A total of 990 urine specimens were examined over 3 years to determine the validity of direct antimicrobial agent susceptibility testing.A total of 1149 strains collected from inpatient urine specimens during Oct 2002-Oct 2005 were identified and the drug resistance test was performed. RESULTS Escherichia coli rated the top one(57.9%),followed with Enterococcus,Proteus,Klebsiella pneumoniae,Pseudomonas aeruginosa,Staphylococcus and fungi.Enterobacteriaceae were showed increasing drug resistance trend,but still sensitive to imipenem(100%).G~+-cocci were also showed serious drug resistance trend,but still sensitive to vancomycin(100%)(except Enterococcus faecium). CONCLUSIONS Enterobacteriaceae are the main infectious bacteria in urinary system infection.Rational use of antibiotics should be carried out according to urine culture result.
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OBJECTIVE To investigate the major pathogenic bacteria and drug resistance of hospital infection in pediatrics unit,and to provide laboratory evidence for clinical diagnosis and treatment.METHODS Pathogenic bacteria were isolated from patients who suffered from hospital infection in pediatrics unit from 2004 to 2006.the method was taken to carry out the sensitive test and bacteria identification by VITEK32,Streptococcus pneumoniae,Moraxella catarrhalis and Haemophylus influenzae were assayed with French Bio-Merieux API System ATB STREP5 and ATB HAEMO,respectively.RESULTS Totally isolated strains were 489.Of them,108 strains of coagulase negative Staphylococcus(CONS),being 22.1%.58 strains were S.haemolyticus.The isolated rate of CONS was 53.7%.The drug test for meticillin-resistant coagulase negative Staphylococcus(MRCNS) showed multiple drug-resistance.The detection rate of the ESBLs from the Escherichia coli and the Klebsiella pneumoniae was 18.9% and 12.5%,respectively.CONCLUSIONS MRCNS are the major pathogens in pediatrics unit.The detectable rate of MRCNS is high.Glycopeptide antibiotics are the first-choice drugs for MRCNS infection.
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OBJECTIVE To study the distribution of the nonfermenter(NF) and the change in its resistance between 2002 and 2005 in our hospital ICU,and instruct clinical application of antibiotics reasonably.METHODS The(identification) of bacteria, antibiotic susceptibility and the detection by VITEK-32 of GNI~+、GNS-142 were used.Etest was applied for detection of metallo-?-lactamase.RESULTS The detective rate of the NF was 57.3%,(58.3%),67.5% and 69.8%,(respectively) from 2002 to 2005.Pseudomonas aeruginosa(PAE),Acinetobacter baumannii and (Stenotrophomonas) maltophilia accounted for 34.3%,11.1% and 4.0%,respectively.The highest distribution of the NF was in the sputum.The resistance rate of PAE to imipenem was lower,(however),it had rose from 0.0% to 17.8% in 2005.The resistance rate of S.maltophilia to sulfamethoxazole/(trimethoprim) was lower than the others,and rose from 0.0% in 2002 to 13.8% in 2005.The incidence rates of(metallo)-?-lactamase of PAE was 0.8% and of A.baumannii was 4.8%,respectively;the incidence rates of metallo-?-lactamase of A.baumannii and PAE were 0.8% and 4.8%,respectively.CONCLUSIONS The(detective) rates of PAE, and A.(baumannii) are gradually increased during the last four years.The incidence of(metallo)-?-lactamase of PAE and A.baumannii is also lower,and the other resistance is existed.
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OBJECTIVE To evaluate the pathogens in department of orthopedics infection and the bacterial resistance to antibiotics,and to provide reference of clinical antibiotic therapy.METHODS A total of 603 pathogenic strains isolated from patients with bone and joint purulent infection,from Apr 2004 to Apr 2007 were retrospectively analyzed with the results of their bacterial cultures and antibiotics sensitivity tests by VITEK32,a part of antibiotics sensitivity tests by K-B and Etest.RESULTS The inspection rate of Pseudomonas aeruginosa,Staphylococcus aureus,S.haemolyticus,S.epidermidis,and Acinetobacter baumannii were 17.08%,14.76%,12.94%,12.27% and 9.65%,respectively.Meticillin-resistant S.aureus(MRSA)was higher than 60.00%,pathogen rate of Gram-positive cocci,Gram-negative bacteria,and Candida were 47.76%,43.78%,and 7.96%,respectively.Staphylococcus were major pathogens of bone and joint purulent infection,multidrug-resistant Staphylococcus infections have increased.CONCLUSIONS Bone and joint purulent infection is mainly caused by Staphylococcus which resist to many antibiotics,A.baumannii and P.aeruginosa are also often found these years.Routine blood culture before using of antibiotics should be taken.The sensitive antibiotics are selected and adjusted according to the results of blood culture and sensitivity test.