Objective To compare the yield and speed of detection of Salmonella subsp, enterica serotypo Paratyphi A from the blood of patients with suspected paratyphoid fever A. Methods With the BacT/ALERT 3D system and paired aerobic and anaerobic bottles (AEB, ANB) that were each filled with 5 ml of blood, the blood culture of 13 500 suspected paratyphoid fever A patients were performed. Results A total of 4 060 isolates were detected. About 3 149 were detected from both AEB and ANB. Four hundred and sixty-one isolates were detected only from the AEB and 450 were only from the ANB. The detection rates of the AEB and ANB were all 26.7% (χ<'2>=0.023, P=0.880). The increased detection rate attributed to the additional blood volume in the AEB and ANB were 11.3% and 11.1%, respectively. The detection speed differed between the two medium formulations. The time to detection was (23.66±15.89) h and (25.48±16.92) h for3 149 isolates, respectively (t=7.007, P<0.01).The mean time to detection was 31.80±20. 97 for 461 isolates discovered with AEB and (33.45±20.72) h for 450 isolates discovered with ANB. Conclusion The blood volume is an important factor in determining the detection rate of blood culture. Although no statistical difference for positive rate was found between the AEB and ANB, more isolates was detected earlier in AEB.

Objective To understand the clinical distribution characteristics and antimicrobial resistance of pathogens causing healthcare-associated infection(HAI) in a comprehensive hospital.Methods Clinical data of patients with HAI in this hospital between May 2012 and May 2015 were collected,the distribution and antimicrobial resistance of pathogens isolated from patients were analyzed.Results A total of 6 563 cases of HAI occurred among 183 850 patients,incidence of HAI was 3.57％,445 patients were isolated at least two kinds of pathogens,375 (84.27％) patients were isolated two kinds of pathogens,132 of whom were infected with both gram negative bacilli.4 478 specimens were sent for pathogenic detection,2 503 (55.90％) of which were isolated pathogens;a total of 2 755 pathogens were isolated,including 1 713(62.18％) strains of gram-negative bacilli,732(26.57％) gram positive cocci,304(11.03％) yeast-like fungi,and 6(0.22％) anaerobic bacteria.524(19.02％)strains were mainly from patients in department of neurology.The main specimen was sputum (n =1 340,48.64％).The isolation rates of carbapenem-resistant Escherichia coli (CREC),Klebsiella pneumoniae (CRKP),Acinetobacter baumnannii (CRAB),and Pseudomonas aeruginosa (CRPA) were 0.39％ (2/510),1.66％ (3/181),59.14％ (207/ 350),and 5.29 ％ (11/208) respectively;isolation rate of methicillin-resistant Staphylococcus aureus (MRSA) was 21.55％(25/116).Conclusion Multidrug-resistant organisms causing HAl are various,it is necessary to understand distribution characteristics and prevalence of pathogens,monitor multidrug-resistant organisms,and implement contact isolation measures,so as to prevent the outbreak of HAI.

Objective To understand the elonal expansion and genetic diversity of Salmonella en-terica semtype Paratyphi A (SPA) and to construct a typing method to determine the epidemic clones of the isolates. Methods Antimicrobial susceptibility testing was performed with 3980 SPA isolates by the cen-trolled Kirby-Bauer disc diffusion technique on Muller-Hinton agar plates. A total of 15 SPA with nalidixie acid resistance for mutations in gyrA, gyrB, gyrC and gyrE genes within the quinolone-resistant determina-tion region (QRDR) were examined. Subtyping of 121 isolates of SPA from seven counties in Yuxi were studied using pulsed-field gel eleetrophoresis (PFGE) analysis following digestion of chromosomal DNA with restriction endanucleases Spe Ⅰ and Xba Ⅰ. PFGE patterns were analyzed by duster analysis. Results The nalidixic acid-susceptible isolates predominated in 1999 but was replaced by nalidixic acid -resistant (NAR) isolates after 2000. Amplification by PCR and sequencing of the genes with subsets of 15 NAR strains re-vealed that the resistance mechanisms had resulted from single point mutations in the gyrA gene. Spe Ⅰ and Xba Ⅰ digestion of 121 isolates gave five and four different PFGE patterns with the predominance of the Spe Ⅰ 01 and Spe Ⅰ 02 (or the Xba Ⅰ 01) epidemic patterns, respectively. Spe Ⅰ 01 and Spe Ⅰ 02 consisted of 37.2% and 57.9% of isolates, respectively, or Xba Ⅰ 01 consisted of 95.0% of isolates. Conclusion The incidence of resistance to nalidixic acid of the isolates increased during the study period. PFGE patterns Spe Ⅰ 01 and Spe Ⅰ 02 (or Xba Ⅰ 01), the main clones of the epidemics, are highly prevalent in Yuxi. PFGE with Spe Ⅰ and Xba Ⅰ is a useful technique to differentiate SPA.