Objective To investigate the effects of meropenem and amikacin on gut microbiota diversity and composition in a neonatal rat model of necrotizing enterocolitis(NEC).Methods Neonatal SD rats(1～2 d,weighing 5～10 g,both sexes)were subjected to establish a NEC model through artificial formula feeding,hypoxic-cold stress,and lipopolysaccharide(LPS)gavage.The rats were randomly divided into normal control group(Group C,n=12),NEC group(Group N,n=20),meropenem intervention group(Group M,n=20),and amikacin intervention group(Group A,n=20).Following modeling,Group M and Group A received intraperitoneal injections of meropenem(125 mg/kg)or amikacin(468 mg/kg),twice daily for 3 consecutive days.Groups C and N were administered an equal volume of normal saline.At the end of the intervention,colonic contents or fecal samples were collected.The gut microbiota structure was analyzed using 16S rDNA high-throughput sequencing.Bioinformatics analysis was performed using the QIIME2 platform.Alpha diversity was evaluated using Chao1,Shannon,and Simpson indices.Beta diversity was assessed based on Bray-Curtis distance through principal coordinate analysis(PCoA)and non-metric multidimensional scaling(NMDS).Venn and UpSet plots were generated to visualize the composition and overlap of operational taxonomic units(OTUs).Linear discriminant analysis effect size(LEfSe)was applied to identify differentially abundant taxa across groups.Results High-throughput 16S rDNA sequencing showed that the N group had significantly lower 3 indices of α diversity than the C group(P<0.01),that is,a Chao1 index from 230 to 40,a Shannon index from 1.65 to 0.85,and a Simpson index from 0.65 to 0.42.After antibiotic intervention,both the M group and A group obtained obvious increases in the Chao1 index than the N group(P<0.001),with a greater increase observed in the M group than in the A group(P<0.05).However,neither antibiotic group exhibited notable improvements in the Shannon index or Simpson index compared with the N group(P>0.05).Venn and UpSet analyses revealed that the M group had the highest number of unique OTUs(283),while the A group shared the most OTUs(63)with the C group.PCoA and NMDS analyses indicated that the microbial structure of the A group was closer to that of the C group,with better clustering.Taxonomic composition and LEfSe analysis demonstrated that the N group was enriched with potentially pathogenic taxa such as Escherichia coli B2 and Klebsiella under the phylum Proteobacteria,while beneficial bacteria including Lactobacillaceae and Bifidobacteriaceae(phylum Firmicutes)were significantly reduced,indicating severe dysbiosis.In contrast,the A group exhibited a significant increase in beneficial bacteria and a structural tendency toward ecological recovery.The M group,however,was enriched with various conditionally pathogenic and environmentally associated genera,displaying a microbial configuration notably deviating from a healthy state.Conclusion Meropenem and amikacin exhibit differential regulatory effects on the intestinal microbiota in the context of NEC.Amikacin demonstrates superior efficacy in restoring microbial stability and levels of beneficial bacteria,whereas meropenem,although effective for early infection control,warrants caution due to its potential long-term impact on the gut microbiome.

Objective To investigate the current situation of clinical nurses′ rights & interests maintenance and occupational stress in Hengyang, and explore the relationship between nurses′rights&interests maintenance and occupational stress.Methods Totally 690 nurses from ten secondary and tertiary hospitals in Hengyang were surveyed during August and September 2015 by general information questionnaires, nurses′rights & interests maintenance questionnaire and nurses occupational stress scale.Results The scores of nurses′rights & interests maintenance and nurses′occupational stress were (3.47±0.67), (3.21±0.95). The score and dimension scores of nurses′rights&interests maintenance were negative correlated with the total score and factor scores of nurses′occupational stress (r=-0.263- -0.425,P< 0.01). Job stress, one child or not, age, role adaptation, monthly income were indicated as predictive factors of rights & interests maintenance of nurses. Conclusions Rights & interests maintenance and occupational stress of nurses has a significant correlation, therefore, the medical and health institutions should further implement relevant laws and regulations; protect rights and interests of nurses from different aspects to reduce occupational stress;and stabilize the nursing team and promote development of nursing career.

OBJECTIVE:To study the difference between the hydrophilic and hydrophobic fluoroquinolones(FQNLs)in?ducing resistant Klebsiella pneumoniae(Kpn)in vitro.METHODS:Hydrophilic ciprofloxacin(CIP)and hydrophobic sparfloxacin(SPFX)were used to induce FQNLs resistant mutants from a clinical susceptible isolate Kpn909with stepwise selection method,respectively,The susceptivity of bacteria to was determined by the standard method of two fold agar dilu?tion.RESULTS:The resistance of Kpn909to FQNLs was raised up gradually as FQNLs'concentration increased;Minimum inhibitory concentrations(MICs)of Kpn9098Selected by CIP at2?MIC(0.5mg/L)were16～32times higher than that of Kpn909,and showed resistant to ofloxacin(OFX),lomefloxacin(LMFX)and enofloxacin(ENX)with a MIC of8mg/L,16mg/L and8mg/L.Otherwise,SPFX-selected Kpn with a similar resistant level occurred at the concentration of8?MIC(1mg/L).The maximal selecting concentration of CIP and SPFX were128mg/L and64mg/L,and MIC of5FQNLs to the resistant mutants obtained at which were≥256mg/L and32～128mg/L,respectively.CONCLUSION:Both hydrophilic CIP and hydrophobic SPFX could induce Kpn the cross resistance to others FQNLs,but hydrophobic FQNLs may be superior to hydrophilic FQNLs to delay the resistance occurrence in Kpn.

Objective To survey the antimicrobial resistance of nosocomial Klebsiella Pneumoniae (Kpn) isolates. Methods All the 68 Kpn strains were isolated and collected from nosocomial infections during April 2002 to March 2003. The susceptivity of bacteria and the production of extended spectrum ?-lactamases (ESBLs) were determined by Kirby-Bauer disc diffusion test and phenotypic confirmatory testing, respectively. Results All 68 Kpn strains were 100% susceptible to Menopenem and Imipenem but resistant to 14 other antimicrobials to different degrees. The first five drugs of high resistant rate were ampicillin (100%), amoxycillin/clavulanic acid (79.4%), sulphamethoxazole/trimothoprim (67.6%), cefotaxime (58.8%), gentamycin (47.0%). There were 28 isolates producing ESBLs (41.2%), which showed much higher resistance to ?-lactam, aminoglycosides, quinolones and sulphamethoxazole/trimothoprim than the non-ESBLs-producing strains. Conclusion Nosocomial Kpn isolates were most multidrug resistant, of which ESBLs-producing strains showed a higher resistance and which may involve other resistant mechanisms.