Objective To investigate the correlation between biofilm gene,efflux pump gene,biofilm forming ability and drug resistance of Acinetobacter baumarmii(AB)isolated from the patients of clinical infectious diseases.Methods A total of 119 non-repeating Acinetobacter baumannii isolates(74 MDR-AB strains and 45 non-multi-drug resistant strains)were collected.The effector pump genes(adeB,adeJ,adeG,adeS and adeR)and biofilm-related genes(bap,ompA,csuA,csuB,csuC,csuD,csuE,abaI,bfmR,bfmS)were detected by PCR.Bacterial biofilm was constructed in vitro with 24-well cell culture plates,and the formation of biofilm was qualitatively observed by crystal violet staining.Results Acinetobacter baumannii was resistant to most of the commonly used antibiotics and sensitive to tigacycline,polymyxin B and minocycline.The overall detection rate of biofilm-related genes was about 80％,and the detection rates of bap,csuB,csuC and csuD genes in multi-drug resistant bacteria were significantly higher than those in non-multi-drug resistant bacteria(P＜0.05).The detection rate of active effector pump genes was less than 70％,and the detection rate of adeB,adeJ,adeS and adeR genes in multidrug-resistant bacteria was significantly higher than that in non-multidrug-resistant bacteria(P＜0.05).The adeG carrying rate was opposite.Three multidrug-resistant strains and five non-multidrug-resistant strains did not carry the above efflux pump related genes,and no abeM gene was detected in all strains.The formation of biofilm was observed in 95.80％of strains.Conclusion Acinetobacter baumannii in hospital is mostly multidrug-resistant strains,most of which have strong biofilm forming ability.Multidrug-resistant bacteria have higher biofilm gene and effluent-pump gene carrying rate,which may be involved in the regulation and formation of multidrug resistance.

l-cysteine is an important sulfur-containing α-amino acid. It exhibits multiple physiological functions with diverse applications in pharmaceutical cosmetics and food industry. Here, a strategy of coordinated gene expression between carbon and sulfur modules in Escherichia coli was proposed and conducted for the production of l-cysteine. Initially, the titer of l-cysteine was improved to (0.38±0.02) g/L from zero by enhancing the biosynthesis of l-serine module (serA^f, serB and serC^Cg) and overexpression of CysB. Then, promotion of l-cysteine transporter, increased assimilation of sulfur, reduction or deletion of l-cysteine and l-serine degradation pathway and enhanced expression of cysE^f (encoding serine acetyltransferase) and cysB^St (encoding transcriptional dual regulator CysB) were achieved, resulting in an improved l-cysteine titer (3.82±0.01) g/L. Subsequently, expressions of cysM, nrdH, cysK and cysIJ genes that were involved in sulfur module were regulated synergistically with carbon module combined with utilization of sulfate and thiosulfate, resulting in a strain producing (4.17±0.07) g/L l-cysteine in flask shake and (11.94±0.1) g/L l-cysteine in 2 L bioreactor. Our results indicated that efficient biosynthesis of l-cysteine could be achieved by a proportional supply of sulfur and carbon in vivo. This study would facilitate the commercial bioproduction of l-cysteine.
Escherichia coli/metabolism* ; Cysteine/metabolism* ; Bioreactors ; Sulfur/metabolism* ; Serine/metabolism*

Objective To investigate the optimal time for capsule endoscopy in patients with obscure gastrointestinal bleeding (OGIB) .Methods Data of 76 patients with OGIB underwent capsule endoscopy from January 2013 to December 2014 were retro‐spectively analyzed .They were classified into two groups :emergency capsule endoscopy and non‐emergency capsule endoscopy .The demographic and clinical features and outcomes of capsule endoscopy ,complications and the times of hospital stays and hospitaliza‐tion expenses were compared .Results The overall diagnostic yield of capsule endoscopy was 48 lesions(63 .15% ) .The overall di‐agnostic yield of emergency capsule endoscopy group was 73 .68% (28/38) ,which was significantly higher than that in non‐emer‐gency capsule endoscopy group(52 .63% ,20/38) ,with statistical difference (P< 0 .05) .Conclusion Emergency capsule endoscopy have a higher rate of detection ,patients with OGIB should receive capsule endoscopy as soon as possible .

Objective To investigate the clinical significance of B-type natriuretic peptide(BNP) in the process of fluid resuscita-tion with different crystalloid-colloid ratio in the patients with severe acute pancreatitis (SAP) .Methods Clinical data of 85 SAP patients were analyzed retrospectively in the Emergency Center of Chongqing during January of 2010 to December of 2012 .Early goal-directed therapy(EGDT) was confirmed the end criterion of the end point of resuscitation .Low crystalloid-colloid ratio group (n=45) and high crystalloid-colloid ratio group(n=40) were divided according to crystalloid-colloid ratio (3∶1) as the borderline , BNP were observed at the time point of before fluid resuscitation ,and 1 ,2 ,3 days after resuscitation and the day before discharge . Results Different fluid resuscitation of crystalloid-colloid ratio could improve hemodynamics in patients ,BNP increased with the to-tal amount of resuscitation liquid ,were positively correlated with liquid volume .The total amount of fluid of the high crystalloid-colloid ratio group was significantly higher than that of the low crystalloid-colloid ratio group .Conclusion BNP could guide early fluid resuscitation and low crystalloid-colloid ratio should be adopted for SAP patients .