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Low-Level Antibiotic Resistance among Staphylococcus aureus and Gram-Negative Pathogens from Infected Skin and Soft Tissues in Rural Kenya
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作者 Justin Nyasinga Zubair Munshi +3 位作者 Lillian Musila Ephantus Mbugua Geoffrey Omuse Gunturu Revathi 《Open Journal of Medical Microbiology》 2024年第1期23-38,共16页
Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insig... Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insights on antimicrobial susceptibilities in a rural setting, we examined specimens from suspected SSTIs from two public health facilities in Kenya. We additionally assessed antibiotic use, appropriateness of empiric therapy and risk factors for SSTI. Methodology: Between 2021 and 2023, 265 patients at Kisii and Nyamira County Referral hospitals were enrolled. Wound swabs/aspirates were collected and processed following standard microbiological procedures. Identification and antimicrobial susceptibility were performed using the VITEK 2 Compact platform. Demographic, clinical, and microbiological data were analyzed with R Statistical software. Results: S. aureus was isolated in 16.2% (43/265) of patients with a methicillin resistance (MRSA) proportion of 14% (6/43). While 13/15 drugs elicited susceptibilities ranging from 84% - 100%, penicillin (16%) and trimethoprim-sulfamethoxazole [TMP-SXT] (23%) yielded the lowest susceptibilities. Escherichia coli (n = 33), Klebsiella pneumoniae (n = 8), Pseudomonas aeruginosa (n = 8), and Citrobacter species (n = 4) were the most commonly isolated gram-negative species. Gram-negative strains showed high susceptibilities to most of the tested drugs (71% - 100%) with the exception of ampicillin (18%), TMP-SXT (33%), and first and second generation cephalosporins. Conclusions: The low MRSA prevalence and generally high antibiotic susceptibilities for S. aureus and gram-negative bacteria present opportunities for antibiotic stewardship in the study setting. Diminished susceptibilities against penicillin/ampicillin and TMP-SXT accord with prevailing local data and add a layer of evidence for their cautious empiric use. 展开更多
关键词 S. aureus MRSA gram-negative Bacteria Antimicrobial Resistance SSTIs Kenya
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Polyethylene glycol fusion repair of severed sciatic nerves accelerates recovery of nociceptive sensory perceptions in male and female rats of different strains
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作者 Liwen Zhou Karthik Venkudusamy +9 位作者 Emily A.Hibbard Yessenia Montoya Alexa Olivarez Cathy Z.Yang Adelaide Leung Varun Gokhale Guhan Periyasamy Zeal Pathak Dale R.Sengelaub George D.Bittner 《Neural Regeneration Research》 SCIE CAS 2025年第9期2667-2681,共15页
Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Walle... Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits. 展开更多
关键词 autophagia AXOTOMY collateral sprouting neuropathic pain peripheral nerve repair polyethylene glycol fusion(PEG-fusion) saphenous nerve sensory neurons sex and strain Wallerian degeneration
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High mortality associated with gram-negative bacterial bloodstream infection in liver transplant recipients undergoing immunosuppression reduction 被引量:5
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作者 Fang Chen Xiao-Yun Pang +6 位作者 Chuan Shen Long-Zhi Han Yu-Xiao Deng Xiao-Song Chen Jian-Jun Zhang Qiang Xia Yong-Bing Qian 《World Journal of Gastroenterology》 SCIE CAS 2020年第45期7191-7203,共13页
BACKGROUND Immunosuppression is an important factor in the incidence of infections in transplant recipient.Few studies are available on the management of immunosuppression(IS)treatment in the liver transplant(LT)recip... BACKGROUND Immunosuppression is an important factor in the incidence of infections in transplant recipient.Few studies are available on the management of immunosuppression(IS)treatment in the liver transplant(LT)recipients complicated with infection.The aim of this study is to describe our experience in the management of IS treatment during bacterial bloodstream infection(BSI)in LT recipients and assess the effect of temporary IS withdrawal on 30 d mortality of recipients presenting with severe infection.AIM To assess the effect of temporary IS withdrawal on 30 d mortality of LT recipients presenting with severe infection.METHODS A retrospective study was conducted with patients diagnosed with BSI after LT in the Department of Liver Surgery,Renji Hospital from January 1,2016 through December 31,2017.All recipients diagnosed with BSI after LT were included.Univariate and multivariate Cox regression analysis of risk factors for 30 d mortality was conducted in the LT recipients with Gram-negative bacterial(GNB)infection.RESULTS Seventy-four episodes of BSI were identified in 70 LT recipients,including 45 episodes of Gram-positive bacterial(GPB)infections in 42 patients and 29 episodes of GNB infections in 28 patients.Overall,IS reduction(at least 50%dose reduction or cessation of one or more immunosuppressive agent)was made in 28(41.2%)cases,specifically,in 5(11.9%)cases with GPB infections and 23(82.1%)cases with GNB infections.The 180 d all-cause mortality rate was 18.5%(13/70).The mortality rate in GNB group(39.3%,11/28)was significantly higher than that in GPB group(4.8%,2/42)(P=0.001).All the deaths in GNB group were attributed to worsening infection secondary to IS withdrawal,but the deaths in GPB group were all due to graft-versus-host disease.GNB group was associated with significantly higher incidence of intra-abdominal infection,IS reduction,and complete IS withdrawal than GPB group(P<0.05).Cox regression showed that rejection(adjusted hazard ratio 7.021,P=0.001)and complete IS withdrawal(adjusted hazard ratio 12.65,P=0.019)were independent risk factors for 30 d mortality in patients with GNB infections after LT.CONCLUSION IS reduction is more frequently associated with GNB infection than GPB infection in LT recipients.Complete IS withdrawal should be cautious due to increased risk of mortality in LT recipients complicated with BSI. 展开更多
关键词 Immunosuppressive therapy Liver transplantation Bloodstream infection Multidrug-resistant gram-negative bacterium
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Association between infections caused by multidrug-resistant gram-negative bacteria and mortality in critically ill patients 被引量:3
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作者 Elisabeth Paramythiotou Christina Routsi 《World Journal of Critical Care Medicine》 2016年第2期111-120,共10页
The incidence of gram-negative multidrug-resistant(MDR) bacterial pathogens is increasing in hospitals and particularly in the intensive care unit(ICU) setting. The clinical consequences of infections caused by MDR pa... The incidence of gram-negative multidrug-resistant(MDR) bacterial pathogens is increasing in hospitals and particularly in the intensive care unit(ICU) setting. The clinical consequences of infections caused by MDR pathogens remain controversial. The purpose of this review is to summarize the available data concerning the impact of these infections on mortality in ICU patients. Twenty-four studies, conducted exclusively in ICU patients, were identified through Pub Med search over the years 2000-2015. Bloodstream infection was the only infection examined in eight studies, respiratory infections in four and variable infections in others. Comparative data on the appropriateness of empirical antibiotic treatment were provided by only seven studies. In ten studies the presence of antimicrobial resistance was not associated with increased mortality; on the contrary, in other studies a significant impact of antibiotic resistance on mortality was found, though, sometimes, mediated by inappropriate antimicrobial treatment. Therefore, a direct association between infections due to gram-negative MDR bacteria and mortality in ICU patients cannot be confirmed. Sample size, presence of multiple confounders and other methodological issues may influence the results. These data support the need for further studies to elucidate the real impact of infections caused by resistant bacteria in ICU patients. 展开更多
关键词 Critically ILL patients INFECTIONS MULTIDRUG resistance gram-negative pathogens MORTALITY
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Seafood as a Reservoir of Gram-negative Bacteria Carrying Integrons and Antimicrobial Resistance Genes in Japan 被引量:4
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作者 Ashraf M.Ahmed Akito Maruyama +2 位作者 Hazim O.Khalifa Toshi Shimamoto Tadashi Shimamoto 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第12期924-927,共4页
PCR and DNA sequencing were used to screen and characterize integrons and resistance genes in Gram-negative bacteria isolated from seafood products in Japan.A total of 215 Gram-negative bacteria were isolated from loc... PCR and DNA sequencing were used to screen and characterize integrons and resistance genes in Gram-negative bacteria isolated from seafood products in Japan.A total of 215 Gram-negative bacteria were isolated from local and imported seafood samples collected from retail markets in Hiroshima Prefecture.Class 1 integrons containing gene cassettes encoding resistance to trimethoprim 展开更多
关键词 gene Seafood as a Reservoir of gram-negative Bacteria Carrying Integrons and Antimicrobial Resistance Genes in Japan STR CMY
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Impact of Polymyxin Resistance on Virulence and Fitness among Clinically Important Gram-Negative Bacteria 被引量:1
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作者 Yuan Wang Qixia Luo +2 位作者 Tingting Xiao Yunying Zhu Yonghong Xiao 《Engineering》 SCIE EI CAS 2022年第6期178-185,共8页
Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B ... Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review. 展开更多
关键词 POLYMYXIN RESISTANCE VIRULENCE FITNESS gram-negative bacteria Acinetobacter baumannii Escherichia coli Klebsiella pneumoniae
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An Improved Approach for Rapidly Identifying Different Types of Gram-Negative Bacterial Secreted Proteins 被引量:2
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作者 Lezheng Yu Fengjuan Liu +1 位作者 Lixiao Du Yizhou Li 《Natural Science》 2018年第5期168-177,共10页
Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria v... Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria via various secretion systems. These proteins are essential for the virulence of bacteria, so it is crucial to study them for the pathogenesis of diseases and the development of drugs. Using amino acid composition (AAC), position-specific scoring matrix (PSSM) and N-terminal signal peptides, two different substitution models are firstly constructed to transform protein sequences into numerical vectors. Then, based on support vector machine (SVM) and the “one to one”?algorithm, a hybrid multi-classifier named SecretP v.2.2 is proposed to rapidly and accurately?distinguish different types of Gram-negative?bacterial secreted proteins. When performed on the same test set for a comparison with other methods, SecretP v.2.2 gets the highest total sensitivity of 93.60%. A public independent dataset is used to further test the power of SecretP v.2.2 for predicting NCSPs, it also yields satisfactory results. 展开更多
关键词 gram-negative Bacteria SECRETED Protein Position-Specific SCORING Matrix Signal Peptide Support Vector Machine
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Metallo-β-lactamase producing nonfermentative gram-negative bacteria:An increasing clinical threat among hospitalized patients
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作者 Varsha Gupta Shailpreet Sidhu Jagdish Chander 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2012年第9期718-721,共4页
Objective:To detect and evaluate the various methods for metallo-β-lactamases(MBL) production in Pseudomonas aeruginosa(P.aeruginosa) and Acinetobacter species.Methods:A total of 109 P.aeruginosa and 85 Acinetobacter... Objective:To detect and evaluate the various methods for metallo-β-lactamases(MBL) production in Pseudomonas aeruginosa(P.aeruginosa) and Acinetobacter species.Methods:A total of 109 P.aeruginosa and 85 Acinetobacter species were screened for imipenem resistance by Kirby- Bauer disc diffusion methods.Detection of MBL production was(lone by imipenem-EDTA combined disc test,double disc synerygy test(DDST) and imipenem-EDTA MBL E test.Results: A total of 63(57.8%) strains of P.aeruginosa and 46(54.1%) strains of Acinetobacter spp.were found to be resistant to imipenem.Of the 63 imipenem resistant P.aeruginosa tested for MBL production.44(69.89;) were found to be positive and among 46 imipenem resistant Acinetobacter. 19(41.3%) were shown to be the MBL producers.Conclusions:Imipenem-EDTA combined disc test and MBL E test are equally effective for MBL detection in both P.aeruginosa and Acinetobacter spp.,but given the cost-constraints,combined disc can be used as a convenient screening method in the clinical microbiology laboratory. 展开更多
关键词 Carbapenem-imipenem Metallo-β-lactamases Non fermentative gram-negative BACILLI
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Immunogenomics for identification of disease resistance genes in pigs: a review focusing on Gram-negative bacilli
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作者 Shuhong Zhao Mengjin Zhu Hongbo Chen 《Journal of Animal Science and Biotechnology》 SCIE CAS 2013年第1期5-17,共13页
Over the past years, infectious disease has caused enormous economic loss in pig industry. Among the pathogens, gram negative bacteria not only cause inflammation, but also cause different diseases and make the pigs m... Over the past years, infectious disease has caused enormous economic loss in pig industry. Among the pathogens, gram negative bacteria not only cause inflammation, but also cause different diseases and make the pigs more susceptible to virus infection. Vaccination, medication and elimination of sick pigs are major strategies of controlling disease. Genetic methods, such as selection of disease resistance in the pig, have not been widely used. Recently, the completion of the porcine whole genome sequencing has provided powerful tools to identify the genome regions that harboring genes controlling disease or immunity. Immunogenornics, which combines DNA variations, transcriptorne, immune response, and QTL mapping data to illustrate the interactions between pathogen and host immune system, will be an effective genomics tool for identification of disease resistance genes in pigs. These genes will be potential targets for disease resistance in breeding programs. This paper reviewed the progress of disease resistance study in the pig focusing on Gram-negative bacilli. Major porcine Gram-negative bacilli and diseases, suggested candidate genes/pathways against porcine Gram-negative bacilli, and distributions of QTLs for immune capacity on pig chromosomes were summarized. Some tools for immunogenomics research were described. We conclude that integration of sequencing, whole genome associations, functional genomics studies, and immune response information is necessary to illustrate molecular mechanisms and key genes in disease resistance. 展开更多
关键词 PIG gram-negative bacteria Immunogenomics Disease resistance breeding
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Present-day Upper-crustal Strain Rate Field in Southeastern Tibet and its Geodynamic Implications:Constraints from GPS Measurements with ABIC Method 被引量:1
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作者 YANG Shaohua PAN Jiawei +1 位作者 LI Haibing SHI Yaolin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期265-275,共11页
The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic ne... The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic networks.If the discrete observed velocity field is obtained,the velocity related fields,such as dilatation rate and maximum shear strain rate,can be estimated by applying varied mathematical approaches.This study applied Akaike's Bayesian Information Criterion(ABIC)method to calculate strain rate fields constrained by GPS observations in the southeast Tibetan Plateau.Comparison with results derived from other three methods revealed that our ABIC-derived strain rate fields were more precise.The maximum shear strain rate highlighted the Xianshuihe–Xiaojiang fault system as the main boundary for the outward migration of material in southeastern Tibet,indicating rotation of eastern Tibet material around the eastern Himalaya rather than whole extrusion along a fixed channel.Additionally,distinct dilatation rate patterns in the northeast and southwest regions of the fault system were observed.The northeast region,represented by the Longmenshan area,exhibited negative dilatational anomalies;while the southwest region,represented by the Jinsha River area north of 29°N,displayed positive dilatational anomalies.This indicates compression in the former and extension in the latter.Combined with deep geophysical observations,we believe that the upper and lower crusts of the Jinsha River area north of 29°N are in an entire expanding state,probably caused by the escape-drag effect of material.The presence of a large,low-viscosity region south of 29°N may not enable the entire escape of the crust,but instead result in a differential escape of the lower crust faster than the upper crust. 展开更多
关键词 strain rate differential escape ABIC GPS southeastern Tibet
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Epidemiological Characteristics, Resistance Patterns and Spread of Gram-Negative Bacteria Related to Colonization of Patients in Intensive Care Units
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作者 Quésia Souza Damaceno Jacques Nicoli Adriana Cristina Oliveira 《Advances in Infectious Diseases》 2015年第1期14-20,共7页
Our aim was to determine the epidemiological characteristics, the resistance patterns and the spread of Gram negative bacteria related to colonization of patients in adult Intensive Care Units. Methods: A prospective ... Our aim was to determine the epidemiological characteristics, the resistance patterns and the spread of Gram negative bacteria related to colonization of patients in adult Intensive Care Units. Methods: A prospective cohort of patients colonized and/or infected with Gram negative bacteria was conducted at two adult ICUs from hospitals in Brazil (April 2012 to February 2013). Nasal, groin and perineum swabs were performed. Samples were incubated on MacConkey and cetrimide agar (48 h at 37℃) and identification tests (Vitek-BioMérieux), antibiogram (Bauer-Kirby method), Carba NP test, Polymerase Chain Reaction (PCR) and sequencing were performed. The patterns of resistant microorganisms were compared by rep-PCR (Diversilab). Results: There were 53 cases of colonization. In these cases, we identified imipenem-resistant Acinetobacter baumannii (51%), Pseudomonas aeruginosa (32%), Klebsiella pneumoniae ESBL (38%) or imipenem resistant (5.6%). The use of antimicrobials and medical devices were related to colonization (p The resistance patterns expressed by Klebsiella pneumoniae were ESBL (CTX-M, SHV e TEM) and KPC2. A verified profile of Acinetobacter baumannii was related to OXA-23 and OXA-253 (OXA-143 variant). The profiles ESBL and KPC2 expressed by Klebsiella pneumoniae were distributed between the both ICUs. The distribution of OXA-23 and OXA-253 was verified only in one ICU. The similarity of strains ranged from 80% to 95%, highlighting the horizontal transference of these microorganisms. 展开更多
关键词 INTENSIVE Care Unit Bacterial DRUG-RESISTANCE gram-negative AEROBIC Bacteria COLONIZATION
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Detection of 16S rRNA Methylase Genes in Gram-Negative Bacilli Isolated from Hospitals in Changchun, China
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作者 Fan Zhao Hongyan Shi +2 位作者 Jinghua Li Jiaqi Zhou Yanbo Sun 《Advances in Infectious Diseases》 2013年第4期290-294,共5页
Methylation of 16S rRNA is an important mechanism of aminoglycoside resistance among gram-negative pathogens. In this report, 16S rRNA methylase genes were amplified using PCR among gram-negative bacillus isolates fro... Methylation of 16S rRNA is an important mechanism of aminoglycoside resistance among gram-negative pathogens. In this report, 16S rRNA methylase genes were amplified using PCR among gram-negative bacillus isolates from hospitals in the Changchun area of China and 16S rRNA methylase genotypes (armA, rmtB, rmtA, rmtC, rmtD, and npmA) were identified by direct sequencing. Fifty of the isolates (43.1%) harbored 16S rRNA methylase genes. The common 16S rRNA methylase genes were armA and rmtB (12.1% and 31.0%, respectively), whereas the rmtA, rmtC, rmtD, and npmA genes were absent from the sample. It suggests that the predominant 16S rRNA methylase genes among gramnegative bacilli in the Changchun area are armA and rmtB. 展开更多
关键词 16S RRNA Methylases gram-negative BACILLI
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Pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy for activating water and urea oxidation 被引量:1
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作者 Guangfu Qian Wei Chen +5 位作者 Jinli Chen Li Yong Gan Tianqi Yu Miaojing Pan Xiaoyan Zhuo Shibin Yin 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第4期684-694,共11页
Exploitation of oxygen evolution reaction(OER)and urea oxidation reaction(UOR)catalysts with high activity and stability at large current density is a major challenge for energy-saving H_(2) production in water electr... Exploitation of oxygen evolution reaction(OER)and urea oxidation reaction(UOR)catalysts with high activity and stability at large current density is a major challenge for energy-saving H_(2) production in water electrolysis.Herein,we use the pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy activated by NiFe_(2)O_(4)(FeNi/NiFe_(2)O_(4)@NC)for efficiently increasing the performance of water and urea oxidation.Due to the tensile strain effect on FeNi/NiFe_(2)O_(4)@NC,it provides a favorable modulation on the electronic properties of the active center,thus enabling amazing OER(η_(100)=196 mV)and UOR(E_(10)=1.32 V)intrinsic activity.Besides,the carbon-coated layers can be used as armor to prevent FeNi alloy from being corroded by the electrolyte for enhancing the OER/UOR stability at large current density,showing high industrial practicability.This work thus provides a simple way to prepare high-efficiency catalyst for activating water and urea oxidation. 展开更多
关键词 Carbon-encapsulated Tensile strain Catalyst Oxygen evolution reaction Urea oxidation reaction
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Prevalence and Antimicrobial Resistance of Gram-Negative Bacteria Isolates in Shellfish Samples from Two River Estuaries in South-South Nigeria
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作者 Nsikan Samuel Udoekong Bassey Enya Bassey +2 位作者 Anne Ebri Asuquo Otobong Donald Akan Casmir Ifeanyichukwu Cajetan Ifeanyi 《Advances in Microbiology》 2021年第9期428-443,共16页
Antibiotic resistant bacteria pathogens remain the leading cause of shellfish borne diseases and a major health threat to humans worldwide. The objectives of this study were to isolate, identify, and determine the ant... Antibiotic resistant bacteria pathogens remain the leading cause of shellfish borne diseases and a major health threat to humans worldwide. The objectives of this study were to isolate, identify, and determine the antibiotic resistance patterns of Gram-negative bacteria from shellfish. We analyzed a total of 540 shellfish (117 clams, 88 oysters, and 136 periwinkles) samples collected from different vendors at Iko and Douglas Creeks in Akwa Ibom State, South-South Nigeria. Conventional cultural techniques, morphological, biochemical characteristics, and PCR amplification were used to identify the bacterial isolates. Antibiotic susceptibility tests (Kirby-Bauer disk diffusion method) and ESBL phenotype (disk) of the isolates were performed. One hundred and thirty-five (135) Gram-negative bacteria comprising 5 genera and 14 species were detected at a prevalence of: <i>Alcaligenes faecalis</i> <i><b>TRB</b></i>-7 38 (28.2%), <i>Pseudomonas oryzihabitans strain <b>KCB</i>005</b> 16 (11.9%), <i>Paenalcaligenes retgerii strain <b>B</i>5</b> 12 (8.9%) <i>Pseudomonas aeruginosa <b>JB</i>2</b> 10 (7.4%), <i>Providencia stuartii <b>DMC</i>-28b</b> 9 (6.7%), <i>Alcaligenes species <b>TLT</i>151</b> 8 (5.9%), <i>Pseudomonas aeruginosa <b>CIFRI DTSB</i>1</b> 7 (5.2%), <i>Paenalcaligenes species <b>UN</i>24</b> 7 (5.2%), <i>Alcaligenes faecalis <b>BT</i>10</b> 7 (5.2%), <i>Vibrio species strain <b>PrVy</i>108</b> 6 (4.4%), <i>Pseudomonas xiamenensis <b>C</i>10-2</b> 5 (3.7%), <i>Providencia vemicola <b>Bu</i>15_38</b> 4 (2.9%), <i>Pseudomonas anguillisceptica</i> <b>4029</b> 3 (2.2%), and <i>Pseudomonas aeruginosa <b>N</i>15-01092</b> 3 (2.2%). All tested isolates showed various degrees of resistance to the thirteen antimicrobials evaluated. High levels of resistance (100%) to cefepime and imipenem were expressed by all isolates except the <i>Providencia</i> species. For the EBSL indicators, all isolates apart from <i>Alcaligenes</i> species were resistant (100%) to ceftriaxone. All <i>Vibrio</i> species were susceptible to norfloxacin, nalidixic acid, and ceftazidime. The identification of antibiotic resistant Gram-negative bacteria (GNARB) from shellfish in this study highlights the risk of disseminated multi-drug resistance—a serious public health concern. 展开更多
关键词 SHELLFISH gram-negative Bacteria ESBL-Indicators Multi-Drug Resistance Calabar
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Detection of the Production of Klebsiella Pneumoniae Carbapenemase, New Delhi Metallo-Beta-Lactamase and Oxacillinase-48-Type Carbapenemases by Gram-Negative Bacilli in Resource-Limited Setting
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作者 Cecile Okalla Ebongue Gabin Gaël Simo +4 位作者 Jean Pierre Nda Mefo’o Grace Dalle Ngondi Emmanuel Roddy Mengue Guy Pascal Ngaba Dieudonne Adiogo 《Advances in Microbiology》 2021年第10期579-590,共12页
<b>Background:</b> The increasing resistance of bacteria to various antibiotics is a worldwide public health issue. Carbapenems that have elicited great hope in treating infections caused by multidrug-resi... <b>Background:</b> The increasing resistance of bacteria to various antibiotics is a worldwide public health issue. Carbapenems that have elicited great hope in treating infections caused by multidrug-resistant germs have seen their efficacy narrowed over time with the emergence of other novel resistance mechanisms, notably the production of Carbapenemases. <b>Methods:</b> A prospective cross-sectional study was conducted from May 2017 to May 2018 in Douala (Cameroon) to detect carbapenemase-producing Gram-negative bacilli. Isolated strains were identified using the Vitek2<sup>TM</sup> system. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method on agar plates with 20 selected commercially available antibiotic discs. The bacterial strains were tested for the production of three Carbapenemases (OXA-48, NDM, KPC), using an immuno-chromatographic technique, with the “RESIST-3 O.K.N. K-SeT” rapid detection kit. <b>Results:</b> During the study period, 1687 strains of Gram-negative bacilli were isolated in selected laboratories with a total of 200 multi-resistant strains identified (11.9%). Among the multi-resistant strains, <i>E. coli</i> was the species most represented in <i>Enterobacteriaceae</i> (27.5%) followed by <i>K. pneumoniae</i> (15.5%) and the non-fermenting Gram-negative bacilli were predominantly <i>P. aeruginosa</i> (20.5%). These strains mainly came from urine and pus, <i>i.e.</i> 41% and 32% respectively. Thirty-two (16%) strains produced one of the Carbapenemases with a higher frequency at the General Hospital (84%). NDM-type carbapenemase was the most frequently identified (8.5%), OXA-48 type 7.5%, and no KPC production was observed. Among the <i>Enterobacteriaceae</i> 22.9% produced Carbapenemases and only 5.1% of the non-fermenting bacilli produced these enzymes. The isolates strains were completely resistant to all antibiotics except Amikacin and Fosfomycin. The strains producing the NDM-type carbapenemase showed higher rates of resistance to almost all of the antibiotics tested. <b>Conclusion:</b> Multidrug-resistant strains are experiencing an increase in evolution. The apparition of strains producing Carbapenemases prominently, the NDM and OXA-48 favor this increase. The activities of antibiotics with high efficacies on these strains are low. 展开更多
关键词 CARBAPENEMASES gram-negative Bacilli MULTIDRUG-RESISTANCE Cameroon
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Impact of an Antimicrobial Stewardship Program Initiative on Antibiotic Optimization in Patients with Gram-Negative Bacteremia
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作者 Veena Venugopalan Victor Chen Levita Hidayat 《Journal of Pharmacy and Pharmacology》 2014年第9期534-540,共7页
The purpose of this study was to critically evaluate the impact of an institutional blood culture notification protocol called RAIDS (rapid administration of antimicrobials by an infectious diseases specialist) on t... The purpose of this study was to critically evaluate the impact of an institutional blood culture notification protocol called RAIDS (rapid administration of antimicrobials by an infectious diseases specialist) on time to optimization of antimicrobial therapy in hospitalized patients with gram-negative bacteremia. Time to antibiotic optimization was compared in patients with gram-negative bacilli isolated from blood cultures obtained from March-May 2011 (pre-RAIDS) versus March-May 2013 (post-RAIDS). The results show that patients in the pre-RAIDS study group had a significantly longer time to antibiotic optimization when compared to the post-RAIDS group (median (IQR), 27.6 (10.8-75.8) h vs. 3.1 (0.8-34.3) h, p = 0.03). The RAIDS protocol resulted in quicker time to antibiotic de-escalation (pre- vs. post-RAIDS; median (IQR), 27.6 (10.8-134.5) h vs. 4.3 (1.4-32.6) h, p = 0.03). There were no differences in clinical outcomes such as clinical cure, microbiological cure, and 30-day mortality between pre-RAIDS and post-RAIDS study groups. Patients in the post-RAIDS arm were more likely to receive appropriate empiric and definitive treatment. Implementation of the RAIDS protocol, which was an ASP (antimicrobial stewardship program) initiative, resulted in quicker time to antibiotic de-escalation and overall treatment optimization. RAIDS reduced the unnecessary use of broad-spectrum antimicrobial in this study population. 展开更多
关键词 gram-negative bacteremia antimicrobial stewardship antibiotic de-escalation.
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The role of strain in oxygen evolution reaction
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作者 Zihang Feng Chuanlin Dai +5 位作者 Zhe Zhang Xuefei Lei Wenning Mu Rui Guo Xuanwen Liu Junhua You 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期322-344,I0009,共24页
The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER... The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field. 展开更多
关键词 Oxygen evolution reaction strain generation Tensile strain Compressive strain strain mechanism strain effects
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Mechanical behavior of nanorubber reinforced epoxy over a wide strain rate loading
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作者 Yinggang Miao Jianping Yin +1 位作者 Wenxuan Du Lianyang Chen 《Nano Materials Science》 EI CAS CSCD 2024年第1期106-114,共9页
Nanorubber/epoxy composites containing 0,2,6 and 10 wt%nanorubber are subjected to uniaxial compression over a wide range of strain rate from 8×10^(-4) s^(-1) to~2×10^(4) s^(-1).Unexpectedly,their strain rat... Nanorubber/epoxy composites containing 0,2,6 and 10 wt%nanorubber are subjected to uniaxial compression over a wide range of strain rate from 8×10^(-4) s^(-1) to~2×10^(4) s^(-1).Unexpectedly,their strain rate sensitivity and strain hardening index increase with increasing nanorubber content.Potential mechanisms are proposed based on numerical simulations using a unit cell model.An increase in the strain rate sensitivity with increasing nanorubber content results from the fact that the nanorubber becomes less incompressible at high strain,generating a higher hydro-static pressure.Adiabatic shear localization starts to occur in the epoxy under a strain rate of 22,000 s^(-1) when the strain exceeds 0.35.The presence of nanorubber in the epoxy reduces adiabatic shear localization by preventing it from propagating. 展开更多
关键词 strain rate strain hardening Nano rubber EPOXY Adiabatic shearing localization
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Comparison of the serum contents of inflammatory mediators and oxidative stress mediators between patients with gram-positive bacteria and gram-negative bacteria infection
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作者 Yu-Qing Hao Fang Chen +1 位作者 Li-Sha Jiang Wei Huo 《Journal of Hainan Medical University》 2017年第22期132-135,共4页
Objective: To compare the serum contents of inflammatory mediators and oxidative stress mediators between patients with gram-positive bacteria and gram-negative bacteria infection. Methods: Patients who were diagnosed... Objective: To compare the serum contents of inflammatory mediators and oxidative stress mediators between patients with gram-positive bacteria and gram-negative bacteria infection. Methods: Patients who were diagnosed with bloodstream bacterial infection in Zigong Third People's Hospital between March 2015 and April 2017 were selected as the research subjects and divided into gram-positive group and gram-negative group according to the results of blood culture and strain identification, and serum levels of inflammatory mediators PCT, IL-1β, IL-6, sTREM-1, TNF-α, NGAL, SAA, HPT and hs-CRP as well as oxidative stress mediators MDA, AOPP, TAC, CAT and SOD were determined. Results: Serum PCT, IL-1β, IL-6, sTREM-1, TNF-α, NGAL, SAA, HPT, hs-CRP, MDA and AOPP levels of gram-negative group were greatly higher than those of gram-positive group while TAC, CAT and SOD levels were greatly lower than those of gram-positive group. Conclusion: The changes of inflammatory mediators and oxidative stress mediators in the serum of patients with gram-negative bacteria infection are more significant than those of patients with gram-positive bacteria infection. 展开更多
关键词 BLOODSTREAM INFECTION GRAM-POSITIVE BACTERIA gram-negative BACTERIA Inflammatory RESPONSE Oxidative stress RESPONSE
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Screening of Myocardial Cardiotoxicity Induced by Anticancer Chemotherapy and the Importance of Global Longitudinal Strain
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作者 Marguerite Téning Diouf Fatou Aw +20 位作者 Hussein Khadra Sophie Ba Doudou Diouf Michel Ngonar Sarr Joseph Salvador Mingou Malick Ndiaye Simon Antoine Sarr Momar Dioum Aliou Alassane Ngaide Serigne Mor Beye Simon Manga Alain Affangla Youssou Diouf Khadimu Rassoul Diop Malick Bodian Mohamed Leye Mouhamadou Bamba Ndiaye Alassane Mbaye Adama Kane Maboury Diao Abdoul Kane 《World Journal of Cardiovascular Diseases》 CAS 2024年第6期381-391,共11页
Introduction: The improvement of survival in patients with cancer and the expansion of therapeutic options have led to the emergence of a new profile of cardiotoxicity, specifically associated with antimitotic agents.... Introduction: The improvement of survival in patients with cancer and the expansion of therapeutic options have led to the emergence of a new profile of cardiotoxicity, specifically associated with antimitotic agents. Our study aimed to assess the incidence of chemotherapy-induced myocardial toxicity in patients with cancer. Patients and Methods: We conducted a looking-forward longitudinal cohort study including all patients admitted to the Cardiology departments of Aristide le Dantec Hospital and Dalal Jamm National Hospital Centre for apre-chemotherapy check-up. The included patients did not undergo any pre-existing cardiopathy. Results: Over a period of two years ranging from January 2019 to December 2021, a total of 37 patients were included in the study. Notably, there was a female predominance (92%) with an average age of 49.7 years ± 13.69. Breast cancer accounted for 70% of the neoplasms. Laboratory findings revealed moderate anemia in 19 patients (51%). At inclusion, the left ventricle (LV) was of normal size (LV diastole at 44.46 ± 4.97 mm). The systolic function of the left ventricle was normal in all patients, with an average ejection fraction (EF) of 63.1% ± 5.80 and a mean global longitudinal strain (GLS) of −20.4% ± 2.58. The most commonly used agents were anthracyclines. During follow-up, 3 patients (8.1%) developed clinical symptoms of left heart failure, and LV dysfunction on echocardiography was observed in 5 (13.5%) patients, with a significant decrease in EF Conclusion: The incidence of cardiac toxicity is not negligible, hence the importance of early screening. Strain imaging is an essential tool that should be performed as part of the assessment before chemotherapy and re-evaluated during treatment. 展开更多
关键词 Cancer CHEMOTHERAPY Global Longitudinal strain CARDIOTOXICITY
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