Objective To analyze the distribution of Escherichia(E .) coli in clinical infection and its drug resistance situation to provide the scientific evidence for the control of outside hospital infection and nosocomial infection and clinical rational drug use . Methods E .coli isolated situation among various types of clinical samples in our hospital during 5 years from January 2010 to De‐cember 2014 ,its department distribution and drug resistance were analyzed .Results The isolated 2 405 strains of E .coli were mainly originated from urine samples (1 049 strains ,43 .60% ) and sputum samples (562 strains ,3 .4% ) .In which the detection rate of extended‐spectrum beta‐lactamase(ESBLs)producing E .coli was 57 .92% ;the resistance rate of E .coli to the most antibacterial drugs including penicillins ,cephalosporins ,fluroquinolones ,aminoglycosides and sulfonamides was more than 50% ,the drugs with the resistance less than 10% were imipenem(0) ,meropenem(0) ,piperacillin/tazobactam(4 .6% ) ,cefoperazone/sulbactam(6 .4% ) and cefoxitin (7 .7% ) ,the resistance to partial third and fourth generation cephalosporins of ceftriaxone ,cefotaxime and cefepime showed the significantly increasing trend .Conclusion E .coli has relatively serious drug resistance situation in hospital‐acquired in‐fections ,clinic should strengthen the pathogen distribution monitoring and drug resistance detection for avoiding the generation of more drug resistant strains in order to reduce the bacterial drug resistance and the hospital infection rate .

Objective To evaluate the value of GeneXpert MTB/RIF assay in the clinical diagnosis of tuberculosis and tuberculosis associated rifampin resistance. Methods A total of 851 patients admitted to the Guangxi Longtan Hospital from September 22, 2015 to May 25, 2016 were enrolled. The smear microscopic examination, solid culture test, and GeneXpert MTB/RIF assay was performed on each patient. Drug sensitivity test of rifampicin using proportion method was done on patients infected with mycobacterium tuberculosis isolated by solid culture, and rifampicin resistance detection was performed on GeneXpert MTB/RIF positive patients. Bacteriological positive consistency test was performed on GeneXpert MTB/RIF and solid culture, and rifampicin resistance detection was compared bwtween GeneXpert MTB/RIF and drug sensitivity using proportion method. Culture and drug susceptibility testing were used as the gold standard, and the MTB sensitivity and specificity of smear microscopic examination, solid culture, and GeneXpert MTB/RIF assay was compared. Results Culture was used as the gold standard. Compared with culture, the sensitivity, specificity, positive predictive value, and negative predictive value of GeneXpert MTB/RIF was 95.48%(211/241), 94.91%(559/569), 87.55%(211/241), and 98.24%(559/569) respectively. The sensitivity of Xpert MTB/RIF for culture positive smear positive specimens and culture positive smear negative specimens was 98.78% (162/164) and 85.96%(49/57) respectively. Drug susceptibility testing was used as the gold standard. Compared with drug susceptibility testing, the sensitivity, specificity, positive predictive value, and negative predictive value of rifampin resistance measured by GeneXpert MTB/RIF was 98.70%(152/154), 92.98%(53/57), 97.44%(152/156) and 96.36%(53/55) respectively. The consistency rate of GeneXpert MTB/RIF and solid culture was 93.83% (Kappa = 0.847), and that of GeneXpert MTB/RIF rifampin resistance detection and proportion method for drug sensitivity was 96.38% (Kappa = 0.904). Conclusions The GeneXpert MTB/RIF detection is easily operated with high sensitivity and specificity compared with smear microscopic examination and solid culture, and it also possesses good consistency with solid culture and traditional drug sensitivity. Moreover, it could also be applied to diagnose the resistance to rifampin, which is very promising in application.

Objective:To explore the characteristics of type 3 secretion system and biofilm of Pseudomonas aeruginosa in diabetic foot wound, and to analyze the relationship between these factors, as well as to the antibiotic sensitivity.Methods:Thirty-three strains of Pseudomonas aeruginosa were collected from the foot wounds of diabetic foot inpatients in Tianjin Medical University Chu Hsien-I Memorial Hospital from February 1, 2018 to December 31, 2018. Thirteen strains of Pseudomonas aeruginosa were collected from non-diabetic wounds. All strains were tested for antibiotic sensitivity. The virulence genes exoS or exoU of Pseudomonas aeruginosa and the ability of biofilm formation were tested. The characteristics of exoS or exoU and biofilm of Pseudomonas aeruginosa were analyzed. Patients′ clinical outcomes were also analyzed.Results:Pseudomonas aeruginosa with exoS gene was the major pathogen, 90.9% found in diabetic foot group and 84.6% in control group, with no significant difference( χ2=0.54, P=0.46). The drug-resistant strains of Pseudomonas aeruginosa with exoS accounted for 16.7% in diabetic foot group and 18.2% in control group, also with no significant difference( χ2=0.18, P=0.83). There were 5 strains of Pseudomonas aeruginosa carrying exoU, 3 strains in diabetic foot group, of which 1 was resistant, 2 in control group, no resistant strain. Pseudomonas aeruginosa increased the ability of biofilm formation in diabetic foot group, accounting for 57.6%, and for resistant strains, 83.3% of them increased the biofilm formation ability. Two kinds of Pseudomonas aeruginosa produced different biofilms, but they were effectiveless for carbapenem antibiotics. The times of debridement ( P<0.01), time of antibiotic use ( P<0.01) were more in biofilm wound, but the healing rate reached 75%-90%. Conclusion:Pseudomonas aeruginosa secreting ExoS is the main one in the diabetic foot wound. The ability of Pseudomonas aeruginosa to produce biofilm in DF wound is increased. Biofilm is one reason for its antibiotic resistance. Multiple debridement combined with sensitive antibiotics is an effective method to remove biofilm.

Objective To analyze the distribution and drug resistance patterns of carbapenem-resistant Acinetobacter baumannii(CRAB),and evaluate the antimicrobial effects in vitro of colistin(COL)combined with cefoperazone/sulbactam(SCF),tigecycline(TGC),imipenem(IPM),meropenem(MEM),amikacin(AK),and levofloxacin(LEV)against CRAB to provide guidance for anti-infective therapy.Methods A total of 75 non-duplicate CRAB strains isolated from clinical specimens in 2022 were collected.WHONET 5.6 software was used for retrospective analysis of their clinical distribution and resistance profiles.Among them,25 strains were selected for combined antimicrobial susceptibility tests using broth microdilution to determine minimum inhibitory concentrations(MICs).The fractional inhibitory concentration(FIC)index was calculated based on checkerboard method to assess the combined effects.Results In 2022,a total of 145 Acinetobacter baumannii strains were isolated,including 75 CRAB(detection rate of 51.7％).CRAB was most prevalent in the patients over 70 years old(40.0％),mainly from blood(41.3％)and sputum(37.3％)specimens,and the intensive care unit was the top isolating department.All the 75 CRAB strains were resistant to piperacillin,piperacillin/tazobactam,ceftriaxone,1PM and MEM with resistance rates of 100％.The resistance rates for ampicillin/sulbactam,cefepime and tri-methoprim/sulfamethoxazole were all exceeded 95％.The resistance rates were 86.7％for LEV,82.7％for SCF,77.4％for AK,2.4％for TGC,and 0.0％for COL.The results of combined tests of 25 strains revealed the synergy rates of 92％and 80％for COL+SCF and COL+TGC respectively with sums of both synergy and additive rates of 100％.Synergy rates for COL combined with IPM,MEM,AK and LEV were 64％,72％,56％and 48％respectively.No antagonism was observed in any combination.Conclusion The drug resist-ance of CRAB exhibited high levels at our hospital,and the elderly and ICU patients were the major susceptible populations.Among all the combinations tests,COL+SCF showed optimal synergy while COL+LEV only had the lowest combined effect with the findings that warrants clinical consideration.

Objective To observe the susceptibility test result in vitro of the combination of two drugs to carbapenem-resistant Enter-obacteriaceae(CRE)for screening the effective anti-infective therapy.Methods A total of 60 CRE strains which were isolated from the specimens from the clinic of Qingdao Eighth People's Hospital from January 2023 to December 2023.Carbapenem enzyme type was detected by colloidal gold immunochromatography.The minimal inhibitory concentration(MIC)was determined by micro broth dilution method.Ceftazidime/avibactam(CZA)combined with aztreonam(ATM),COL combined with tigecycline(TGC),meropenem(MEM),cefoperazone/sulbactam(SCF),amikacin(AK)and levofloxacin(LEV),TGC combined with MEM,SCF and AK,MEM combined with SCF and ertapenem(ETP)were performed by the checkerboard dilution method respectively.Fractional inhibitory con-centration(FIC)index was used to determine the combined effects.Results Carbapenem enzyme was detected in all the 60 CRE strains,including 49 Klebsiella pneumoniae carbapenemases(KPC)-type,10 New Delhi metallo-β-lactamase(NDM)-type and 1 Imi-penem enzyme(IMP)-type.The MICs of CZA to 49 KPC-producing strains were ≤8 mg/L,showing all sensitive,and to 11 NDM-and IMP-producing strains were＞128 mg/L,showing all resistant.The synergy rate of CZA was 100％after combining with ATM.MEM combined with SCF had the highest synergy rate of 63.4％,and the sum of synergistic rate and addition rate was 96.7％.The syn-ergistic rate and additive rate of TGC combined with AK were the lowest,which was 31.7％.Among KPC and NDM enzyme types strains,the sum of synergy rate and addition rate of MEM combined with SCF were the highest,which were 100.0％and 80.0％respec-tively.The sum of synergy rate and addition rate of COL combined with LEV were the lowest,which were 32.6％and 30.0％.None of the 11 combination regimens showed antagonistic effect.The MICrange,MIC50 and MIC90 of combination regimens for CRE strains were decreased to some extent compared with those of each single drug.Conclusion CZA alone or in combination with ATM were effective for CRE strains.The MEM combined with SCF had the highest synergy rate and addition rate,which could provide reference for clinical experience medication.