CuO Bionanocomposite with Enhanced Stability and Antibacterial Activity against Extended-Spectrum Beta-Lactamase Strains

Worldwide, bacterial resistance to beta-lactam antibiotics is the greatest challenge in public health care. To overcome the issue, metal-based nanoparticles were extensively used as an alternative to traditional antibiotics. However, their unstable nature limits their use. In the present study a very simple, environmentally friendly, one-pot synthesis method that avoids the use of organic solvents has been proposed to design stable, novel nanocomposites. Formulation was done by mixing biogenic copper oxide (CuO) nanomaterial with glycerol and phospholipids isolated from egg yolk in an appropriate ratio at optimum conditions. Characterization was done using dynamic light scattering DLS, Zeta potential, high performance liquid chromatography (HPLC), and transmission electron microscopy (TEM). Further, its antibacterial activity was evaluated against the extended-spectrum beta-lactamase strains based on zone of inhibition and minimal inhibitory concentration (MIC) indices. Results from this study have demonstrated the formulation of stable nanocomposites with a zeta potential of 34.9 mV. TEM results indicated clear dispersed particles with an average of 59.3 ± 5 nm size. Furthermore, HPLC analysis of the egg yolk extract exhibits the presence of phospholipids in the sample and has significance in terms of stability. The newly formed nanocomposite has momentous antibacterial activity with MIC 62.5 μg/mL. The results suggest that it could be a good candidate for drug delivery in terms of bactericidal therapeutic applications.     

耐三代头孢菌素沙门菌的耐药基因分析

目的了解耐三代头孢菌素沙门菌的耐药基因分布特征,为疾病的防控和治疗提供依据。方法选取对头孢噻肟(CTX)和(或)头孢他啶(CAZ)耐药的临床分离的沙门菌157株,进行血清学分型和超广谱β-内酰胺酶(ESBLs)确证试验,采用PCR方法检测7种β-内酰胺类耐药基因。结果157株沙门菌中,分布有20种血清型,以鼠伤寒沙门菌和肠炎沙门菌为主。共127株检出耐药基因,检出率为80.89%,包括bla_TEM103株、bla_CTX-M79株、bla_OXA-109株和bla_SHV1株,未检出bla_PER、bla_CMY和bla_ACC。ESBLs阳性80株,占50.96%;其中23株(28.75%)检出1种耐药基因,50株(62.50%)检出2种耐药基因,7株(8.75%)检出3种耐药基因;携带的耐药基因模式以bla_CTX-M-1G+bla_TEM(35株)、bla_CTX-M-9G+bla_TEM(14株)和bla_CTX-M-9G(12株)多见。ESBLs阴性77株,占49.04%;其中46株(59.74%)检出1种耐药基因,1株(1.30%)检出2种耐药基因,30株(38.96%)未检出耐药基因;携带的耐药基因模式以bla_TEM(46株)为主。对CTX耐药的沙门菌和对CTX不耐药的沙门菌bla_CTX-M的检出率差异有统计学意义(χ²=83.366,P=0.000)。对CAZ耐药的沙门菌和对CAZ不耐药的沙门菌bla_TEM检出率差异无统计学意义(χ²=0.268,P=0.384)。鼠伤寒沙门菌和肠炎沙门菌bla_CTX-M-1G和bla_CTX-M-9G的携带率差异有统计学意义(χ²=6.285,P=0.012;χ²=8.735,P=0.003)。bla_TEM在表型为CAZ耐药、CTX敏感或中介组,CTX耐药、CAZ敏感或中介组及CAZ和CTX均耐药组中的携带率差异无统计学意义(χ²=0.270,P=0.874)。结论耐三代头孢菌素沙门菌携带的耐药基因以bla_TEM和bla_CTX-M为主,同时伴有bla_OXA-10和bla_SHV,呈多样性,需要持续监测和研究。     

2013年河北省细菌耐药监测网三级甲等医院临床分离大肠埃希菌耐药性分析

目的：了解2013年河北省细菌耐药性监测网(Hebarin)三级甲等医院临床分离大肠埃希菌对所监测抗菌药物的敏感和耐药情况。方法收集2013年 Hebarin 上报数据合格单位分离自各类临床标本的8076株大肠埃希菌,采用纸片扩散法(K-B 法)或肉汤稀释法进行药敏实验,按照 CLSI(2012年版)判定标准。结果共收集细菌26659株,其中大肠埃希菌8076株,占总构成比30.3%,位于第一位。超广谱β-内酰胺酶(ESBLs)检出率为62.4%。对哌拉西林、头孢呋辛、头孢哌酮、头孢曲松、庆大霉素、环丙沙星、左氧氟沙星、磺胺甲口恶唑/甲氧苄啶(复方新诺明)及氨苄西林舒巴坦等多种抗生素耐药性较高,耐药率>50%;对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦和阿米卡星耐药性较低,耐药率均<10%。大肠埃希菌对亚胺培南、美罗培南耐药性最低,耐药率为0.6%、0.8%。结论大肠埃希菌 ESBLs 检出率较高,碳青霉烯类抗菌药物活性仍为最强,其次是哌拉西林他唑巴坦、头孢哌酮-舒巴坦和阿米卡星。     

Epidemiology and clinical features of community-acquired,healthcare-associated and nosocomial bloodstream infections in tertiary-care and community hospitals

Classification of bloodstream infections (BSIs) as community-acquired (CA), healthcare-associated (HCA) and hospital-acquired (HA) has been proposed. The epidemiology and clinical features of BSI according to that classification in tertiary-care (TH) and community (CH) hospitals were investigated in a prospective cohort of 821 BSI episodes from 15 hospitals (ten TH and five CH hospitals) in Andalucía, Spain. Eighteen percent were CA, 24% were HCA and 58% were HA. The incidence of CA and HCA BSI was higher in CH than in TH (CA: 3.9 episodes per 1000 admissions vs. 2.2, p <0.01; HCA: 5.0 vs. 2.9, p <0.01), whereas the incidence of HA BSI was lower (7.7 vs. 8.7, p <0.01). In CA and HCA BSI, the respiratory tract was more frequently the source in CH than in TH (CA: 30% vs. 15%; HCA: 20% vs. 9%, p ≤0.03). In HCA BSI, chronic renal insufficiency and tunnelled catheters were less frequent in CH than in TH (11% vs. 26% and 7% vs. 19%, p ≤0.03), although chronic ulcers were more frequent (22% vs. 8%, p 0.008). BSIs as a result of methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa were very rare in CA episodes, although extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC) caused a similar proportion of all BSIs in CA, HCA and HA episodes. Multivariate analysis revealed no significant difference in mortality rates in CH and TH. HCA infections should be considered as a separate class of BSI in both TH and CH, although differences between hospitals must be considered. CA BSIs were not caused by multidrug-resistant pathogens, except for ESBLEC.     

Rapid identification of uropathogenic Escherichia coli of the O25:H4-ST131 clonal lineage using the Diversi-Lab repetitive sequence-based PCR system

Several recent studies have highlighted the emergence of a globally disseminated clone of uropathogenic and invasive Escherichia coli isolates of serotype O25:H4 and sequence type 131. The ability to characterize rapidly E. coli isolates of this lineage would facilitate enhanced surveillance for this pathogen. We have used the semi-automated Diversi-Lab repetitive PCR-based system to analyse a collection of 35 clinical isolates of uropathogenic E. coli from across the UK, with particular focus on the O25:H4-ST131 lineage. All isolates had been characterized using multilocus sequence typing (MLST), and 14 had previously been typed using pulsed-field gel electrophoresis (PFGE). The Diversi-Lab system allowed discrimination of O25:H4-ST131 isolates from those of other E. coli lineages. It was slightly more discriminatory than MLST, but was less discriminatory than PFGE. With an analysis time of <4 h between receipt of a cultured organism and provision of a typing result, the system offers information on a real-time basis, a major advantage over current practice. We suggest that introduction of the Diversi-Lab system would be useful for rapid exclusion of E. coli isolates during outbreak investigations, and that the approach could be employed for surveillance for pathogenic or antibiotic-resistant clones of this organism.     

腹泻病原菌中产超广谱β-内酰胺酶菌株的基因型和同源性分析

目的了解分离的产超广谱β-内酰胺酶(ESBLs)腹泻病原菌的基因流行情况。方法采用TEM型、SHV型和CTX-M型ESBLs编码基因的通用引物对产ESBLs菌株进行扩增,并采用PFGE技术对分离的产ESBLs腹泻病原菌进行了DNA指纹图谱分析。结果在分离的产ESBLs的腹泻病原菌中,CTX-M型是最为常见的ESBLs型别,TEM型次之,SHV型最少,CTX-M亚型中CTX-M-14最多,部分产ESBLs腹泻病原菌同时产生一种以上的β-内酰胺酶,少数菌株的ESBLs基因型不属于上述三种基因型。分离的产ESBLs的大肠杆菌有6种基因型,宋内菌有2种基因型,变形杆菌和克雷伯菌只有1种基因型。结论 ESBLs不仅可以存在于不同种的细菌中,也可以存在同一种细菌的不同基因型中,推测这可能是耐药基因在不同细菌或同一细菌不同基因型中平行转移的结果。     

CTX-M β-Lactamase–producing Klebsiella pneumoniae in Suburban New York City,New York,USA

CTX-M extended-spectrum β-lactamase (ESBL)–producing Klebsiella pneumoniae isolates are infrequently reported in the United States. In this study, we analyzed nonduplicate ESBL-producing K. pneumoniae and Escherichia coli clinical isolates collected during 2005–2012 at a tertiary care medical center in suburban New York City, USA, for the presence of bla_CTX-M, bla_SHV, bla_TEM, and bla_KPC genes. Despite a high prevalence of bla_CTX-M genes in ESBL-producing E. coli since 2005, bla_CTX-M genes were not detected in K. pneumoniae until 2009. The prevalence of CTX-M–producing K. pneumoniae increased significantly over time from 1.7% during 2005–2009 to 26.4% during 2010–2012 (p<0.0001). CTX-M-15 was the dominant CTX-M genotype. Pulsed-field gel electrophoresis and multilocus sequence typing revealed high genetic heterogeneities in CTX-M–producing K. pneumoniae isolates. This study demonstrates the recent emergence and polyclonal spread of multidrug resistant CTX-M–producing K. pneumoniae isolates among patients in a hospital setting in the United States.     

产超广谱β-内酰胺酶大肠埃希菌耐药表型和基因型分析

目的:分析临床分离大肠埃希菌耐药性、产超广谱β-内酰胺酶(ESBLs)阳性率及耐药基因之间的关系。方法:用K-B法检测117株大肠埃希菌耐药性,用酶抑制剂增强实验纸片法检测产ESBLs菌株,用PCR法检测相关耐药基因,用DNA序列分析确认基因亚型。结果:117株大肠埃希菌产ESBLs 49株,阳性率41.9%。产ESBLs菌株对青霉素类和第一、第二代头孢菌素耐药率100%,对第三代头孢菌素中头孢哌酮、头孢噻肟和头孢曲松耐药率>95%,对酶抑制剂哌拉西林/三唑巴坦和头孢哌酮/舒巴坦耐药率<20%,未检测到亚胺培南耐药株。非产ESBLs菌株耐药率明显低于产ESBLs菌株。49株产ESBLs菌株PCR均扩增到CTX-M型耐药基因,44株扩增到TEM型基因,未扩增到其他基因型。DNA序列分析证实为CTX-M-14亚型、CTX-M-3亚型和广谱酶TEM-1亚型基因。结论:大肠埃希菌产ESBLs较高,耐药显著;耐药基因以CTX-M-14亚型为主,其次为CTX-M-3亚型,尚未检出其他ESBLs基因。TEM-1亚型广谱内酰胺酶基因在大肠埃希菌中普遍存在。     

血流感染产超广谱β-内酰胺酶大肠埃希菌的药敏结果及感染危险因素分析

目的 分析血流感染产超广谱β-内酰胺酶(ESBLs)大肠埃希菌的药敏特点和危险因素,为临床诊疗和预防提供依据.方法 回顾性分析商洛市中心医院111例大肠埃希菌血流感染的药敏结果 和临床特点,根据大肠埃希菌是否产ESBLs分为ESBLs组和非ESBLs组,分析两组药敏结果 差异,并探讨产ESBLs大肠埃希菌血流感染的危险...     

Early prediction models for extended-spectrum β-lactamase-producing Escherichia coli infection in emergency department: A protocol for systematic review and meta analysis

Background:Resistance in gram-negative bacteria has gained great importance in recent decades and one reason is the rapid increase of extended spectrum β-lactamase (ESBL)-producing bacteria as a growing problem worldwide. The increasing proportion of ESBL-producing Enterobacteriaceae (ESBL-E) infections acquired in the emergency community is a new feature of ESBLs epidemiology. Early recognition of patients with extended-spectrum β-lactamase-producing Escherichia coli infection is important in the emergency department. To mitigate the burden on the healthcare system, while also providing the best possible care for patients, early recognition of the infection is needed.Methods:For the acquisition of required data of eligible prospective/retrospective cohort study or randomized controlled trials (RCTs), we will search for publications from PubMed, Web of science, EMBASE, Cochrane Library, Google scholar. Two independent reviewers will read the full English text of the articles, screened and selected carefully, removing duplication. Then we evaluate the quality and analyses data by Review Manager (V.5.4). Results data will be pooled and meta-analysis will be conducted if there''s 2 eligible studies considered.Results:This systematic review and meta-analysis will evaluate the value of the early prediction models for Extended-spectrum β-lactamase-producing E coli infection in emergency department.Conclusions:This systematic review and meta-analysis will provide clinical evidence for predicting Extended-spectrum β-lactamase-producing E coli infection in emergency department, inform our understanding of the value of the predictive model in predicting Extended-spectrum β-lactamase-producing E coli infection in emergency department in the early stage. The conclusions drawn from this study may be beneficial to patients, clinicians, and health-related policy makers.Study registration number:INPLASY202130049.