Tigecycline(TGC)is a recently developed broad-spectrum and highly effective glycylcy-cline antibiotic that overcomes traditional tetracycline resistance mechanisms.It is widely used in the treatment of complex skin and intra-abdominal infections.However,the emergence of TGC re-sistance in recent years poses a significant challenge,and its underlying resistance mechanisms re-main incompletely understood,warranting further investigation.This study induced TGC resistance in Klebsiella aerogenes(ATCC-43864)under in vitro conditions and evaluated phenotypic chan-ges,including growth curves,motility,multidrug susceptibility,and ultrastructural alterations,be-fore and after induction.Whole-genome sequencing(WGS)and transcriptome sequencing(RNA-seq)were employed to analyze resistance-related genetic changes,which were further validated.Ef-flux pump inhibition assays and Red homologous recombination were used to investigate the roles of efflux pumps,lon deletion,and rpsM mutation in TGC resistance.A stable resistant strain,CF-T-32,was obtained,with a 32-fold increase in TGC minimum inhibitory concentration(MIC).CF-T-32 exhibited an enlarged periplasmic space between the cell wall and membrane,reduced growth and motility,and no significant changes in susceptibility to 28 antimicrobial agents,including doxy-cycline,gentamicin,and ciprofloxacin.Genomic analysis revealed no significant differences in ge-nome composition or interference from exogenous plasmids between the parental and induced strains.However,two missense mutations were identified in rpsM and lon.Transcriptomic analysis and qPCR validation showed significant upregulation of efflux pump genes(acrA and acrB)in the AcrAB-TolC system and downregulation of ribosomal protein genes(rpsM,rpsJ,and rpsC).Ef-flux pump inhibition and Red homologous recombination experiments demonstrated that the rpsM C287T missense mutation,leading to a Pro96Leu substitution and reduced expression,is likely the primary factor contributing to TGC resistance in the induced strain.

Tigecycline(TGC)is a recently developed broad-spectrum and highly effective glycylcy-cline antibiotic that overcomes traditional tetracycline resistance mechanisms.It is widely used in the treatment of complex skin and intra-abdominal infections.However,the emergence of TGC re-sistance in recent years poses a significant challenge,and its underlying resistance mechanisms re-main incompletely understood,warranting further investigation.This study induced TGC resistance in Klebsiella aerogenes(ATCC-43864)under in vitro conditions and evaluated phenotypic chan-ges,including growth curves,motility,multidrug susceptibility,and ultrastructural alterations,be-fore and after induction.Whole-genome sequencing(WGS)and transcriptome sequencing(RNA-seq)were employed to analyze resistance-related genetic changes,which were further validated.Ef-flux pump inhibition assays and Red homologous recombination were used to investigate the roles of efflux pumps,lon deletion,and rpsM mutation in TGC resistance.A stable resistant strain,CF-T-32,was obtained,with a 32-fold increase in TGC minimum inhibitory concentration(MIC).CF-T-32 exhibited an enlarged periplasmic space between the cell wall and membrane,reduced growth and motility,and no significant changes in susceptibility to 28 antimicrobial agents,including doxy-cycline,gentamicin,and ciprofloxacin.Genomic analysis revealed no significant differences in ge-nome composition or interference from exogenous plasmids between the parental and induced strains.However,two missense mutations were identified in rpsM and lon.Transcriptomic analysis and qPCR validation showed significant upregulation of efflux pump genes(acrA and acrB)in the AcrAB-TolC system and downregulation of ribosomal protein genes(rpsM,rpsJ,and rpsC).Ef-flux pump inhibition and Red homologous recombination experiments demonstrated that the rpsM C287T missense mutation,leading to a Pro96Leu substitution and reduced expression,is likely the primary factor contributing to TGC resistance in the induced strain.

This study aims to analyze the main drug resistance mechanism of Salmonella enteritidis induced by polymyxin in vitro.In this study,the resistance of Salmonella enteritidis CMCC(B)50335(ZK)to polymyxin was induced in vitro,and the growth characteristics,exercise ability,ul-trastructure and sensitivity to 16 antimicrobial agents before and after induction were determined by turbidimetry,semi-solid agar method,transmission electron microscope and disk diffusion method,and the whole genome and single nucleotide polymorphism(SNP)were detected by Illu-mina NovaSeq PE150 method.RT-qPCR was used to detect the differences in the expression levels of six drug-resistant related genes.The recombinant strain △phoPE1-128-1,which induced drug-resistant strain E1-128-1,was constructed by homologous recombination of Red Escherichia coli,and its sensitivity to polymyxin was detected.The results showed that three strains of induced drug-resistant bacteria E1-128-1,E1-128-3 and E2-128-3 were screened out,and the MIC increased by 128,64 and 64 times respectively after drug resistance stability test.Induced drug resistance had no significant effect on the growth ability of the tested bacteria and the sensitivity of 16 antibacte-rial drugs.The exercise ability of E1-128-1was significantly increased,and the cell wall and plasma membrane obviously thicken.There was no significant difference in the genome components of E1-128-1 before and after induction,but eight missense mutations of six drug-resistance related genes,including phoP/phoQ,cpxP,lptD,csrA and acrB,were detected,including four missense mutation sites of phoP,namely Leu185Trp,His189Ser,Thr190Tyr and Ile191His.The corresponding genes were sequenced by PCR,and the results were consistent with those of SNP.RT-qPCR results showed that the expression levels of mutant genes of the three induced strains increased signifi-cantly.Compared with E1-128-1,the MIC of △phoP E1-128-1 decreased to 1 mg/L.It is sug-gested that the mutation and increased expression of phoP gene are important factors for inducing polymyxin resistance of Salmonella CMCC(B)50335 in vitro.

Objective To explore the clinical effect of laparoscopic radical nephrectomy by retroperitoneal in 65 cases.Methods 65 patients who received retroperitoneal laparoscopic radical nephrectomy were selected as the observation group,and their clinical data were analyzed.At the same period,S0 patients treated by open operation were selected as the control group.The clinical effect was compared between the two groups.Results The operation time,intraoperative blood loss,hospital stay,incision infection,pulmonary infection,hypercapnia,intestinal injury of observation group were lower than those of control group (t =7.60,8.38,8.83,x2 =8.33,6.19,4.08,4.08,all P ＜0.05).The positive margin rate,local recurrence rate,distant metastasis rate of two groups were not significantly different (P ＞ 0.05).Conclusion Laparoscopic radical nephrectomy by retroperitoneal has advantages of small wound,quicker recovery,less complications and good prognosis,which is worthy of clinical application.

Objective To approach the clinical curative effect of retroperitoneal laparoscopic adrenalectomy.Methods 120 adrenal tumors patients clinical data of urinary surgery in our hospital were analyzed,who was divided into detection group(80 cases) and control group(40 cases).Results The operation time,bleeding volume,postoperative exhaust time,hospitalization time,incision infection,pulmonary infection,intestinal injury of detection group were lower than those of control group (t =5.59,21.17,26.32,6.01,x2 =7.79,7.79,5.13,all P ＜ 0.05).Conclusion Retroperitoneal laparoscopic adrenalectomy has some advantages:the small incision,less trauma,faster postoperative recovery,less complication,,which was worth of applying.

Objective To evaluate clinical efficacy of retroperitoneal laparoscopic adrenalectomy in patients with adrenal disease.Methods 21 cases of adrenal disease undergoing retroperitoneal laparoscopic adrenalectomy from Jun.2006 to Oct.2010 were retrospectively reviewed.Results All operations were performed successfully except 2 cases were converted to open surgery due to peritoneal rupture,which resulted in difficult exposure of retroperitoneal cavity.The operation time ranged from 55 to 300 minutes,with 90 minutes as the medium.Blood loss volume ranged from 10 to 100 ml during operation (30 ml as the medium ).No blood transfusion was given.No complication such as massive hemorrhage,infection,abdominal visceral injury etc.occurred.19 patients were treated successfully and followed up from 3 to 55 months with 12.3 months as the medium.No tumor recurrence and metastasis was found in the 19 cases.Conclusion Retroperitoneal laparoscopic adrenalectomy has advantages of high safety,less complications and satisfactory efficacy in patients with adrenal diseases.

Objective To study the topoanatomy of anterior perineal plane and adjoining tissue structure in the preparation of ultra-low anterior resection of the rectum. Methods Dissection was performed on 16 male cadavers of semi-pelvis sectioned in the saggital plane. Eight indexes were measured and recorded. Results Anterior perineal plane was clearly found in all 16 cadavers. The median distance of rectum-urethra (R-U) was 14 mm (ranging 10 -17 mm). The contour of perineal body was trapezoid,which was narrow cranially and broad caudally. The median width of cranial perineal body was 8 mm (ranging 6 -9 mm), while the median width of caudal perineal body was 21 mm (ranging 18 -23 mm).The median numerus of thickness of perineal body (TPB), thickness of puborectalis (TPR), arrterior wall of rectum (aPR) -D, pPR-D and width of pelvic diaphragm (WPD) were 20. 5 mm ( ranging 17 - 23 mm),12 mm(ranging 10 -16 mm), 25 mm(ranging 21 -27 mm), 20 mm(ranging 16 -23 mm) and 8 mm (ranging 6 - 10 mm) respectively. Conclusions Anterior perineal plane clearly exists, through which about 20 mm more length of the distal rectum is available which could increase the sphincter-saving rate in cases of low rectal carcinoma.