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Characteristics of β-Lactamase Synthesis in E. coli and K. pneumanie Strains in Nosocomial Infections
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作者 Saddraddin A. Atakishizadeh Sayyaddin A. Atakishizadeh Mahammad M. Davudov 《Advances in Microbiology》 CAS 2024年第1期25-30,共6页
Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomi... Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomial urinary tract infections, surgical site infections and pneumonia in surgical clinic were studied. ESBL synthesis were observed 38.9% of E. coli strains obtained from urine, 92.3% of strains obtained from surgical site infections, and 50% of strains obtained from sputum. ESBL synthesis were observed 37.5% of K. pneumoniae strains obtained from urine, 85.7% of strains obtained from surgical site infections, and 60% of strains obtained from sputum. Different levels of ESBL synthesize of E. coli and K. pneumoniae strains isolated from different pattern is discussed. Conclusion. ESBL synthesis is common in E. coli and K. pneumoniae strains, which cause nosocomial infections. The frequency of occurrence of ESBL s synthesis among of these strains depends on clinical forms of nosocomial infections. 展开更多
关键词 Nosocomial Infectious Agents β-lactamase Synthesis E. coli and K. pneumoniae
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Occurrence of K1 and K2 serotypes and genotypic characteristics of extended spectrumβ-lactamases-producing Klebsiella pneumoniae isolated from selected hospitals in Malaysia
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作者 Nurul Syazrah Anuar Hazmin Hazman +5 位作者 Sharven Raj Jeyakumar Mohd Nasir Mohd Desa Hasni Idayu Saidi Siti Norbaya Masri Nur Afiza Aziz Nurshahira Sulaiman 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第1期30-38,共9页
Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selecte... Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia.Methods:A total of 192 K.pneumoniae isolates were collected and subjected to antibiotic susceptibility,hypermucoviscosity test and multiplex PCR to detect the presence of K1-and K2-serotype associated genes.Multilocus sequence typing(MLST)was performed on ESBL-producing K.pneumoniae isolates presented with K1 and K2 serotypes,followed by phylogenetic analysis.Results:A total of 87 out of 192(45.3%)of the K.pneumoniae isolates collected were ESBL producers.However,only 8.3%(16/192)and 10.9%(21/192)of the total isolates were detected to carry K1-and K2-serotype associated genes,respectively.Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype(P=0.196).However,they were significantly associated with hypervirulent,as demonstrated by the positive string test(P<0.001).MLST analysis revealed that ST23 as the predominant sequence type(ST)in the K1 serotype,while the ST in the K2 serotype is more diverse.Conclusions:Although the occurrence of ESBL-producing isolates among the hypervirulent strains was low,their coexistence warrants the need for continuous surveillance.MLST showed that these isolates were genetically heterogeneous. 展开更多
关键词 Extended spectrumβ-lactamases Klebsiella pneumoniae Capsular serotypes GENOTYPIC
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Prevalence and Risk Factors of Penicillinase-Type β-Lactamase Producing Neisseria gonorrhoeae Isolated from Patients Attending Health-Facilities in Yaounde, Cameroon
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作者 Cécile Ingrid Djuikoue Laurene Nzangem Doumene +10 位作者 Cedric Seugnou Nana Joviale Magne Talla Herman Koyouo Tagne Blondelle Kitio Messeu Farid Wega Tobie Vianney Kamany Kamdem Willy Yamdeu Djonkouh Ghandhi Fossouo Ndieffouo Carole Tayimetha Benjamin D. Thumamo Pokam Nicolas Antoine-Moussiaux 《Open Journal of Medical Microbiology》 2023年第3期220-233,共14页
Background and Objectives: Mitigation of antibiotic resistant Neisseria gonorrhoeae has become a priority due to considerable health and economical disabilities it generates. In order to tackle the emergence of resist... Background and Objectives: Mitigation of antibiotic resistant Neisseria gonorrhoeae has become a priority due to considerable health and economical disabilities it generates. In order to tackle the emergence of resistant Neisseria gonorrhoeae, this study aimed to determine the prevalence and risk factors of penicillinase type β-lactamase-producing Neisseria gonorrheae among patients consulting for genital infectious disorders in two health-facilities in Yaounde, Cameroon. Materials and Method: A cross-sectional descriptive and analytical study was conducted over a 3-month period, from July 2<sup>nd</sup> to October 2<sup>nd</sup>, 2022. Vaginal and urethral secretions were collected. Biochemical identification tests were performed on colonies grown on chocolate agar + polyvitex using the Api NH gallery. The detection of penicillinases was equally performed using the API NH gallery and confirmed using the antimicrobial susceptibility testing. The Minimum Inhibitory Concentrations of some antibiotics were determined using the E-Test. Results: The results showed that out of the 198 patients sampled, 16 (8.08%) were positive for Neisseria gonorrhoeae, among which 13/16 (81.25%) were penicillinase-type β-lactamase producers. Antimicrobial susceptibility testing results showed high co-resistances to antibiotics, mainly ciprofloxacin (100%), nalidixic acid (92.31%) and azithromycin (84.62%). Moreover, high Minimum Inhibitory Concentrations of ceftriaxone (ranging from 6 to 24 mg/L) was observed toward Neisseria gonorrhoeae isolates. The risk factors of the carriage of penicillinase-type β-lactamase producing Neisseria gonorrhoeae identified were: a history of Sexually Transmitted infections (p = 0.01) and unprotected sexual intercourse (p = 0.01). Conclusion: The emergence of penicillinase-type β-lactamase producing Neisseria gonorrhoeae is increasing and the situation is becoming worrisome. The identified risk factors can constitute a basic outlook to tackle resistant Neisseria gonorrhoeae, and therefore sustain antibiotic stewardship. 展开更多
关键词 Neisseria gonorrhoeae Antimicrobial Resistance β-lactamase PENICILLINASE Cameroon
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Evaluation of Disk Potentiation Test (DPT) and Double Disk Synergy Test (DDST) for The Detection of Metallo-β-Lactamases (MBLs) in Clinical Isolates of Bangladesh
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作者 Sumon Kumar Das Afzal Sheikh +4 位作者 Nikhat Ara Suma Mita Biswas Abhinandan Chowdhury Fatimah Az Zahra Chaman Ara Keya 《Advances in Infectious Diseases》 2023年第4期609-626,共18页
Objective: Increasing the emergence of Metallo-β-lactamase (MBL) producing gram-negative bacteria and their dexterous horizontal transmission demands rapid and accurate detection. This study was conducted to determin... Objective: Increasing the emergence of Metallo-β-lactamase (MBL) producing gram-negative bacteria and their dexterous horizontal transmission demands rapid and accurate detection. This study was conducted to determine a suitable method to promptly detect MBL-producing gram-negative bacteria. Methods: A total of 103 gram-negative bacteria were identified from various clinical samples at a tertiary care hospital in Dhaka city. MBL producers were detected by two phenotypic methods, the Disk Potentiation Test (DPT) and the Double Disk Synergy Test (DDST) based on β-lactam chelator combinations where EDTA/SMA has been used as an inhibitor and Imipenem, Ceftazidime as substrates. Results: 103 isolates which were identified as Escherichia coli spp, Klebsiella spp, Pseudomonas spp, Acinetobacter spp, Proteus spp, Providencia spp were found to be multidrug-resistant in antibiogram test. Isolates showed complete resistance (100%) to Imipenem, Meropenem, and Amoxiclav. The highest carbapenem-resistant etiological agents were Acinetobacter spp 40 (38.8%) followed by Pseudomonas spp 27 (26.2%), Klebsiella spp 26 (25.2%), Escherichia coli 8 (7.8%), Proteus spp 1 (1%) and Providencia spp 1 (1%). DPT method detected significantly (p = 0.000009) a higher number of MBL-producers (Imipenem with 0.5 M EDTA n = 61, 59.2% & Ceftazidime with 0.5 M EDTA n = 56, 54.4%) compared to the DDST method (Imipenem -0.5 M EDTA n = 43, 41.7%, Imipenem – SMA n = 38, 36.9% & Ceftazidime -0.5 M EDTA n = 15, 14.6%). Conclusion: Pieces of evidence suggest that DPT is a more sensitive method than DDST and could be recommended for identifying MBL-producing bacteria in Bangladeshi hospitals for the proper management of patients, to reduce time constraints and treatment costs. 展开更多
关键词 Disk Potentiation Test (DPT) Double Disk Synergy Test (DDST) Metallo-β-lactamase (MBL) Sodium Mercaptoacetate (SMA) and Ethylenediaminetetraacetic Acid (EDTA)
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L1 β-Lactamase催化反应机理研究 被引量:1
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作者 徐定国 鄢国森 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2008年第12期2453-2456,共4页
用混合量子力学和分子力学(QM/MM)方法和密度泛函理论讨论了L1β-Lactamase催化Nitrocefin水解的过程,研究结果表明,反应为多步反应:第一步亲核进攻反应为反应的决速步骤,并且伴随着酰胺键的断裂,第二步反应为质子迁移反应.同时讨论了... 用混合量子力学和分子力学(QM/MM)方法和密度泛函理论讨论了L1β-Lactamase催化Nitrocefin水解的过程,研究结果表明,反应为多步反应:第一步亲核进攻反应为反应的决速步骤,并且伴随着酰胺键的断裂,第二步反应为质子迁移反应.同时讨论了金属锌在反应中的作用. 展开更多
关键词 混合量子力学和分子力学(QM/MM) 密度泛函理论 β-lactamase 水解反应
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Antimicrobial Resistance and Genotype Analysis of Extended-Spectrum-β-Lactamase-Producing Proteus Mirabilis 被引量:1
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作者 Ying Huang Yuanhong Xu +1 位作者 Zhongxin Wang Xianghong Lin 《Open Journal of Clinical Diagnostics》 2014年第1期57-62,共6页
To analyse the genotypes of clinical isolates of Extended-Spectrum-β-Lactamase-Producing (ESBL-producing) Proteus mirabilis (P. mirabilis) and the mechanisms of antimicrobial resistance, to guide reasonable use of an... To analyse the genotypes of clinical isolates of Extended-Spectrum-β-Lactamase-Producing (ESBL-producing) Proteus mirabilis (P. mirabilis) and the mechanisms of antimicrobial resistance, to guide reasonable use of antibiotics and to avoid nosocomial outbreak infections by ESBL-producing P. mirabilis. 125 clinical isolates of P. mirabilis were collected from the Drug-Resistant Bacteria Surveillance Center of Anhui Province (from Jan 2009 to May 2010). Searching for the genotypes of ESBLs was perfomed by PCR amplification and DNA sequencing, and performed conjugation test simultaneously. Among ESBL-producing strains, CTX-M was the major genotype (3 CTX-M-13 and 1 CTX-M-3). TEM-1b spectrum β-lactamase was also prevalence in P. mirabilis. The diversity of β-lactamases in P. mirabilis and the emergency of multi-drug-resistance clinical strains will present serious threat to clinical therapy and even will lead to outbreak of nosocomial infections. Our study emphasizes the need for enhanced supervision of ESBL-producing P. mirabilis. Timely and reasonable drug-resistance data are indispensable to clinical therapy. 展开更多
关键词 GENOTYPE Extended-Spectrum-β-lactamase ANTIMICROBIAL Resistance PROTEUS Mirabilis
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Intestinal carriage of methicillin resistant Staphylococcus aureus and extended-spectrum β-Lactamase-producing Enterobacteriacae in hospitalized and nonhospitalized patients and their clinical implications
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作者 Hanan Ahmed Habib Babay Ali Mohammed Somily 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2009年第3期41-45,共5页
Objective:To determine the clinical implication of and intestinal carriage with methicillin resistant Staphylococcus aureus(MRSA) and extended spectrumβ-lactamase(ESBL)-producing Enterobacteriacae.Methods: A total of... Objective:To determine the clinical implication of and intestinal carriage with methicillin resistant Staphylococcus aureus(MRSA) and extended spectrumβ-lactamase(ESBL)-producing Enterobacteriacae.Methods: A total of 180 stool specimens were screened for MRSA and ESBL-producing enterobacteria.Identification of ESBL- producing Enterobacteriacae was done by MicroScan Walk Away 96 system(Dade Behring Inc.,West Sacramento,CA 95691,USA ) and confirmation by double-disc synergy test.MRSA was identified by disc diffusion using 30μg cefoxitin disc and the MicroScan.Results:The rate of fecal MRSA carriage was 7.8% (14/180),35.7%(5 /14) were recovered from surgical wards.Three patients(21,4%) had MRSA recovered from other body sites,and 2(14.2%) had in addition ESBL -producing Escherichia coli(E.coli) and Klebsiella pneumoniae(K.pneumoniae) respectively.Four(28.5%) patients with MRSA fical carriage died. MRSA fecal carriage was recovered from both inpatients and outpatients.Four(2.2%) cases carried ESBL-producing Enterobacteriacae in feces.Three(75%) were from intensive care unit(ICU).One patient had both ESBL-producing E.coli and K.pneumoniae from stool as well as E.coli from tracheal aspirate.Two ICU patients with fecal ESBL died.Conclusion:Fecal screening for MRSA and ESBL of all patients at high risk admitted to different hospital wards and ICUs and implementing infection control measures were recommended. 展开更多
关键词 INTESTINAL CARRIAGE METHICILLIN resistant Staphylococcus aureus EXTENDED spectrumβ-lactamase Enterobacteriacae
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EXTRACELLULAR RELEASE OF β-LACTAMASE BY OSMOTIC SHOCK IN SYNECHOCOCCUS TRANSFORMANT
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作者 Shin-ichi Yano Yoshikazu Kawata Hiroyuki Kojima(Osaka National Research Institute, Agency of Industrial Science and Technology, Ikeda, Osaka 563, Japan ) 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1998年第S1期105-108,共4页
A unicellular cyanobacterium Synechococcus sp. strain PCC 7002 was transformedwith plasmid pQL1, on which β-lactamase gene (bla) and β-galactosidase gene (lacZ) were encoded.The transformant cells released β-lactam... A unicellular cyanobacterium Synechococcus sp. strain PCC 7002 was transformedwith plasmid pQL1, on which β-lactamase gene (bla) and β-galactosidase gene (lacZ) were encoded.The transformant cells released β-lactamase into medium by an abrupt drop of osmotic pressure. This re-sult indicates that this cyanobacterium recognizes and processes the signal sequence of β-lactamase, andaccumulates the enzyme in periplasm. Repeated release of β-lactamase was possible by repeated osmoticshocks without impairing cell viability. On the other hand, most of the β-galactosidase remained in cyto-plasm under the osmotic shock. 展开更多
关键词 SYNECHOCOCCUS perienzyme β-lactamase OSMOTIC shock
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Studies of β-lactamase production in ampicillin resistant Haemophilus influenzae
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作者 方正 陈海兵 +3 位作者 束学安 修清玉 罗文侗 戴旭明 《Journal of Medical Colleges of PLA(China)》 CAS 2000年第4期244-246,共3页
Objective:To study the molecular mechanisms of β-lactamase production in ampicillin resistant(AmP ) Hae- mophilus influenzae(HI). Methods: Identified the β-lactamases production strain from AmP HI was isolated from ... Objective:To study the molecular mechanisms of β-lactamase production in ampicillin resistant(AmP ) Hae- mophilus influenzae(HI). Methods: Identified the β-lactamases production strain from AmP HI was isolated from clinical cases with K-B method. β-lactamase encoding gene in enzyme production strains were detected by PCR with lactamase gene specific primers, and both plasmid and chromosomal DNA samples. Results: Thirty-two out of 36 (88 .9% ) were found to be β-lactamase production. Twenty-nine out of 32 enzyme production stain were PCR positive (the ratio of PCR positives 90.6% ). There were 25 stains amplified with plasmid DNA positively, and 4 with chromosomal DNA. Conclusion: (l ) Most of the AmPr HI strain produce lactamase is mediated by plasmid. (2) Detection of lactamase encoding gene in HI is a simple and efficient approach to study the molecular basis of ampicillin resistance. 展开更多
关键词 HAEMOPHILUS influenzae β-lactamase DRUG resistant MICROBIAL
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Clinical Isolates of Staphylococcus aureus Show Variation in β-Lactamase Production and Are More Susceptible to Antibiotics Conjugated with β-Lactamase Inhibitors
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作者 Uzal Umar Umar Ahmed Faruk +1 位作者 Damoroem M. Tanko Mohammed B. Yerima 《Open Journal of Medical Microbiology》 2016年第4期143-149,共7页
β-Lactam antibiotics are a cornerstone in the treatment of bacterial infections on account of its high therapeutic index and selective toxicity—they act by inhibiting the biosynthesis of peptidoglycan, a key compone... β-Lactam antibiotics are a cornerstone in the treatment of bacterial infections on account of its high therapeutic index and selective toxicity—they act by inhibiting the biosynthesis of peptidoglycan, a key component in bacterial cell wall. Ninety (90) clinical specimens obtained from the microbiology unit Specialist Hospital Bauchi were screened for S. aureus, positive isolates were examined for β-Lactamase expression by using two Penicillin G concentrations (5000 IU/ml and 25,000 IU/ml) in acidometric agar technique with phenol red as indicator, and the susceptibility pattern of the isolates to β-Lactam antibiotics was also determined. S. aureus prevalence of 31% (28/90) was obtained, of which 96% (27/28) of strains were β-Lactamase positive in the standard test, while 63% (17/27) were able to hydrolyze penicillin G concentration of 25,000 IU/ml (5X the concentration in the standard test), and a strain was found to be β-Lactamase negative. The resistance to five β-Lactams, ampicillin, cephalexin, amoxicillin, cloxacillin and flucloxaillin, were 100%, 96%, 89%, 74% and 56% respectively. When ampicillin and amoxicillin were conjugated to β-Lactamase inhibitors sulbactam and clavulanic acid respectively the resistance to ampicillin decreased to 21% and to amoxicillin to 15%. The antibiotic susceptibility profile revealed β-Lactamase elaboration to be the major mechanism of resistance to the β-Lactams. β-Lactam utilization as therapeutic option would thus require the search for sensitive irreversible β-Lactamase inhibitors for the β-Lactamase enzymes or agents to block the release of β-Lactamase by strains. 展开更多
关键词 β-lactamase PEPTIDOGLYCAN Transpeptidation HAEMOLYSIS Resistance ANTIBIOTICS
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Detection and Characterization of β-Lactamase Encoding Genes in Carbapenem Non-Susceptible Gram-Negative Bacteria and Susceptibility of Isolates to Ceftazidime-Avibactam at a New York City Community Hospital
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作者 Carl Urban Rita Colon-Urban +5 位作者 Vincent J. LaBombardi Noriel Mariano Nishant Prasad Geeti Dhillon Marina Guralnik Sorana Segal-Maurer 《Open Journal of Medical Microbiology》 2016年第4期150-157,共8页
A surveillance study was undertaken to identify prominent β-lactamase encoding genes in 131 carbapenem non-susceptible gram-negative clinical isolates at a New York City community hospital. KPC carbapenemases were de... A surveillance study was undertaken to identify prominent β-lactamase encoding genes in 131 carbapenem non-susceptible gram-negative clinical isolates at a New York City community hospital. KPC carbapenemases were detected in 89% of Enterobacteriaceae as well as additional TEM, SHV, and CTX-M class A enzymes. OXA-23 and OXA-24 were the prevalent class D carbapenemases identified in Acinetobacter species. One OXA-23 in M. morganii and one OXA-48 in K. pneumoniae were also identified. Among class C β-lactamases CMY, ACT/MIR, DHA, and FOX were detected. The in vitro activity of ceftazidime-avibactam by E-test methodology was tested with minimal inhibitory concentrations (MIC) of ≤3 μg/ml for 97.8% of all Enterobacteriaceae, MIC<sub>50/90</sub> of 16/>256 μg/ml for carbapenem non-susceptible Acinetobacter, and 3/6 μg/ml for carbapenem non-susceptible Pseudomonas aeruginosa. Periodic surveillance of isolates to characterize current and emerging β-lactamase genotypes present in local isolates may help identify outbreak situations, provide assistance to infection control and antibiotic stewardship programs, and potentially improve patient outcomes. 展开更多
关键词 Carbapenem Non-Susceptible Check-MDR CT103 XL Microarray β-lactamase Detection Resistance Mechanisms Ceftazidime-Avibactam
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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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Metallo-β-Lactamases:A Major Threat to Human Health 被引量:1
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作者 Emer K.Phelan Manfredi Miraula +3 位作者 Christopher Selleck David L.Ollis Gerhard Schenk Natasa Mitic 《American Journal of Molecular Biology》 2014年第3期89-104,共16页
Antibiotic resistance is one of the most significant challenges facing global healthcare. Since the 1940s, antibiotics have been used to fight infections, initially with penicillin and subsequently with various deriva... Antibiotic resistance is one of the most significant challenges facing global healthcare. Since the 1940s, antibiotics have been used to fight infections, initially with penicillin and subsequently with various derivatives including cephalosporins, carbapenams and monobactams. A common characteristic of these antibiotics is the four-memberedβ-lactam ring. Alarmingly, in recent years an increasing number of bacteria have become resistant to these antibiotics. A major strategy employed by these pathogens is to use Zn(II)-dependent enzymes, the metallo-β-lactamases (MBLs), which hydrolyse theβ-lactam ring. Clinically useful MBL inhibitors are not yet available. Consequently, MBLs remain a major threat to human health. In this review biochemical properties of MBLs are discussed, focusing in particular on the interactions between the enzymes and the functionally essential metal ions. The precise role(s) of these metal ions is still debated and may differ between different MBLs. However, since they are required for catalysis, their binding site may present an alternative target for inhibitor design. 展开更多
关键词 Antibiotic Resistance β-Lactam Antibiotics Metallo-β-lactamases Reaction Mechanism Metal Ion Binding
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Phenotypic and Genotypic Characterization of Extended Spectrum β-Lactamase Klebsiella pneumoniae and Fluorescent Pseudomonas spp. Strains from Market Garden Products and Their Watering Water in Benin (West Africa)
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作者 Wassiyath Moussé Pacôme A. Noumavo +4 位作者 Nicodème W. Chabi Haziz Sina Majoie G. Tohoyessou Théodora A. Ahoyo Lamine Baba-Moussa 《Food and Nutrition Sciences》 2016年第3期192-204,共13页
Market garden products can carry several types of microorganisms, and their consumption is the source of many cases of food poisoning. This work aimed to improve food safety in Benin. In characterizing strains of K. p... Market garden products can carry several types of microorganisms, and their consumption is the source of many cases of food poisoning. This work aimed to improve food safety in Benin. In characterizing strains of K. pneumoniae and fluorescent Pseudomonas spp. at the biochemical and molecular level, the target was to identify contaminated watering water and garden products sold during Cotonou in both the dry and rainy seasons. A total of 164 samples of market garden products and 22 samples of watering water were investigated. The results showed that 5.91% of market garden products and watering water were contaminated by K. pneumoniae and 20.43% by fluorescent Pseudomonas spp. During the dry season, cabbage was most contaminated by fluorescent Pseudomonas spp. (50%). Pool water was more contaminated with K. pneumoniae (17%). All isolated strains were resistant to both amoxicillin and penicillin. All strains of K. pneumoniae and fluorescent Pseudomonas spp. were not resistant to imipenem, and 22% of them produced penicillinase. Among the 49 strains producing penicillinase isolated, 64.29% and 21.43% carried bla<sub>TEM</sub> and bla<sub>SHV</sub> respectively while 14.28% carried bla<sub>CTX-M</sub> genes. In light of the previously-developed results and considering the importance of horticultural products in Beninese food habits, we must improve national awareness of the risk for foodborne illness. 展开更多
关键词 Vegetables Klebsiella pneumoniae Fluorescent Pseudomonas spp. β-lactamaseS Food Safety
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Unravelling Antimicrobial Resistance Phenotypes and Carriage of Extended-Spectrum β-Lactamase Genes in Escherichia coli Isolated from Dairy Farms in Kiambu County, Kenya
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作者 Dan Waithiru John Mwaniki Njeru +4 位作者 John M. Maingi Erastus Mulinge Benjamin Ngugi John Maina John Kiiru 《Advances in Microbiology》 2022年第5期295-315,共21页
The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only ... The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to establish the carriage of multi-drug resistance and extended-spectrum beta-lactamase genes in Escherichia coli from farmers, their cattle, and cattle slurry within Kiambu County. A total of 286 (81%) E. coli isolates were recovered from 352 samples analysed. Antibiotic resistance profiles showed 114 (40%) isolates were resistant to ≥3 antimicrobial classes and were considered multidrug-resistant. Among multidrug-resistant (MDR) E. coli strains, 40 (14%) were resistant to 3 different antimicrobial classes, while 71 (25%) were resistant to between 4 and 7 antibiotic classes. Extended-spectrum β-lactamase resistance was found in 18 isolates: human (n = 14), cattle (n = 2), and environmental (n = 2). Both the bla<sub>CTX-M</sub> and bla<sub>TEM</sub> genes were detected in 10 and 15 strains, respectively. Sequence analysis showed that the isolates carried the bla<sub>TEM-116</sub> (n = 7), bla<sub>TEM-1</sub> (n = 5), and bla<sub>CTX-M-15</sub> (n = 8) genes. Genotyping MDR isolates using (GTG) <sub>5</sub> PCR demonstrated that the isolates were not clonal. This data shows antimicrobial resistance profiles and different types of resistance genes in the E. coli population on dairy farms. As a result, more effective, targeted public health policies and measures need to be put in place to control and prevent the emergence and spread of resistant bacteria. 展开更多
关键词 Humans Cattle Slurry Escherichia coli Multidrug Resistance Extended-Spectrum β-lactamase (ESBL) TEM 116 CTX-M-15 Kenya
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Identification and preliminary characterization of novel B3-type metallo-β-lactamases
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作者 Manfredi Miraula Conor SBrunton +1 位作者 Gerhard Schenk Natasa Mitić 《American Journal of Molecular Biology》 2013年第4期198-203,共6页
Antibiotic resistance has emerged as a major global threat to human health. Among the strategies employed by pathogens to acquire resistance the use of metallo-β-lactamases (MBLs), a family of dinuclear metalloenzyme... Antibiotic resistance has emerged as a major global threat to human health. Among the strategies employed by pathogens to acquire resistance the use of metallo-β-lactamases (MBLs), a family of dinuclear metalloenzymes, is among the most potent. MBLs are subdivided into three groups (i.e. B1, B2 and B3) with most of the virulence factors belonging to the B1 group. The recent discovery of AIM-1, a B3-type MBL, however, has illustrated the potential health threat of this group of MBLs. Here, we employed a bioinformatics approach to identify and characterize novel B3-type MBLs from Novosphingobium pentaromativorans and Simiduia agarivorans. These enzymes may not yet pose a direct risk to human health, but their structures and function may provide important insight into the design and synthesis of a still elusive universal MBL inhibitor. 展开更多
关键词 Antibiotic Resistance β-Lactam Antibiotics Metallo-β-lactamases Sequence Homology Novosphingobium Pentaromativorans Simiduia Agarivorans
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Unusual metallo-β-lactamases may constitute a new subgroup in this family of enzymes
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作者 Chun-Feng D.Hou Emer K.Phelan +3 位作者 Manfredi Miraula David L.Ollis Gerhard Schenk Natasa Mitic 《American Journal of Molecular Biology》 2014年第1期11-15,共5页
Metallo-β-lactamases (MBLs) are a family of Zn2+-dependent enzymes that have contributed strongly to the emergence and spread of antibiotic resistance. Novel members as well as variants of existing members of this fa... Metallo-β-lactamases (MBLs) are a family of Zn2+-dependent enzymes that have contributed strongly to the emergence and spread of antibiotic resistance. Novel members as well as variants of existing members of this family are discovered continuously, compounding their threat to global health care. MBLs are divided into three subgroups, i.e. B1, B2 and B3. The recent discovery of an unusual MBL from Serratia proteamaculans (SPR-1) suggests the presence of an additional subgroup, i.e. B4. A database search reveals that SPR-1 has only one homologue from Cronobacter sakazakii, CSA-1.These two MBLs have a unique active site and may employ a mechanism distinct from other MBLs, but reminiscent of some organophosphate-degrading hydrolases. 展开更多
关键词 Antibiotic Resistance β-Lactam Antibiotics Metallo-β-lactamases Sequence Homology Serratia proteamaculans Cronobacter sakazakii
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Multidrug resistance extended spectrum β-lactamase and AmpC producing Escherichia coli isolated from the environment of Bogor Slaughterhouse,Indonesia
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作者 Mirnawati Bachrum Sudarwanto Denny Widaya Lukman +3 位作者 Trioso Purnawarman Hadri Latif Herwin Pisestyani Eddy Sukmawinata 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2017年第8期708-711,共4页
Objective: To determine the multidrug resistance extended spectrum p-lactamase and AmpC(ESBL/AmpC producing) Escherichia coli(E. coli) isolated from the environment of Bogor slaughterhouse, Indonesia.Methods: A total ... Objective: To determine the multidrug resistance extended spectrum p-lactamase and AmpC(ESBL/AmpC producing) Escherichia coli(E. coli) isolated from the environment of Bogor slaughterhouse, Indonesia.Methods: A total of 35 samples from 7 locations in slaughterhouse i.e., source of water,slaughtering floor, swab of carcass area floor, swab of evisceration area floor, untreated waste water, treated waste water, drinking water for cattle were collected from March to April 2016. Presence of ESBL/AmpC producing E. coli and susceptibility testing against8 antimicrobial agents(penicillin G, streptomycin, gentamycin,ciprofloxacin, enrofloxacin, tetracycline, trimethoprim-sulfamethoxazole, and polymyxin B) were detected by disk diffusion test according to Clinical and Laboratory Standards Institute.Results: ESBL/AmpC producing E. coli were identified in 14.3%(5/35) of the collected samples from the environment of Bogor slaughterhouse. ESBL/AmpC-producing E. coli isolates were detected in untreated waste water(n=3), slaughtering floor(n=1), and carcass area floor(n=1). Most of ESBL/AmpC-producing E. coli isolates(80%) showed multidrug resistance phenotypes against at least three classes of antibiotics. The highest incidence of antibiotics resistance was against penicillin G(100.0%) and streptomycin(100.0%), followed by gentamicin(60.0%), trimethoprim-sulfamethoxazole(60.0%),tetracycline(40.0%), ciprofloxacin(40.0%), enrofloxacin(20.0%), and polymyxin B(0.0%).Conclusions: The transmission of antimicrobial resistant bacteria into the environment may be a potential risk for human health. 展开更多
关键词 Escherichia coli 环境 扩大光谱 -lactamase 屠场
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Selective inhibition of resistant bacterial pathogens using a β-lactamase-activatable antimicrobial peptide with significantly reduced cytotoxicity
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作者 Weipan Xu Zheng Ma +2 位作者 Geetika Dhanda Jayanta Haldar Hexin Xie 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第5期241-245,共5页
The expression ofβ-lactamase,particularly metallo-β-lactamase(MBL)in bacteria has caused significant resistance to clinically importantβ-lactam antibiotics,including life-saving carbapenems.Antimicrobial peptides(A... The expression ofβ-lactamase,particularly metallo-β-lactamase(MBL)in bacteria has caused significant resistance to clinically importantβ-lactam antibiotics,including life-saving carbapenems.Antimicrobial peptides(AMPs)have emerged as promising therapeutic agents to combat antibiotic resistance.However,the cytotoxic AMPs has been one of the major concerns for their applications in clinical practice.Herein,we report a novel cephalosporin-caged AMP,which shows significantly reduced cytotoxicity,hemolytic activity,and antibacterial activity but turns highly active against bacteria upon specific hydrolysis by the antimicrobial resistance-causativeβ-lactamase.Further investigations demonstrate thisβ-lactamaseactivatable AMP selectively inactivates resistant bacterial pathogens over susceptible bacteria.This strategy should be applicable to other AMPs as a potential solution for the treatment of infectious diseases caused byβ-lactamase-expressing pathogenic bacteria. 展开更多
关键词 Antibiotic resistance β-lactamase Antimicrobial peptide CYTOTOXICITY
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An integrated microfluidic chip-mass spectrometry system for rapid antimicrobial resistance analysis of bacteria producingβ-lactamases
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作者 Zhaochen Su Wanting Hu +2 位作者 Lizhen Ye Dan Gao Jin-Ming Lin 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第5期323-326,共4页
Bacteria producingβ-lactamases have become a major issue in the global public health field.To restrain the development of drug resistance and reduce the abuse of antibiotics,it is very important to rapidly identify b... Bacteria producingβ-lactamases have become a major issue in the global public health field.To restrain the development of drug resistance and reduce the abuse of antibiotics,it is very important to rapidly identify bacteria producingβ-lactamases and put forward a reasonable treatment plan.Here,an integrated microfluidic chip-mass spectrometry system was proposed for rapid screening ofβ-lactamaseproducing bacteria and optimization ofβ-lactamase inhibitor dosing concentration.The concentration gradient generator followed by an array of bacterial culture chambers,as well as micro-solid-phase extraction columns was designed for sample pretreatment before mass analysis.By using the combination system,the process of the hydrolysis of antibiotics byβ-lactamase-producing bacteria could be analyzed.To validate the feasibility,four antibiotics and two antibiotic inhibitors were investigated using three strains including negative control,SHV-1 and TEM-1 strains.SHV-1 and TEM-1 strains were successfully distinguished as theβ-lactamase producing strains.And the acquired optimal concentrations ofβ-lactamase inhibitors were in accordance with the results by that obtained from the traditional microdilution broth method.The total analysis time only needed around 2 h,which was faster than conventional methods that require a few days.The technique presented herein provides an easy and rapid protocol forβ-lactamase resistance related studies,which is important for the inhibition of antimicrobial resistance development and the reduction of antibiotics abuse. 展开更多
关键词 MICROFLUIDICS Mass spectrometry β-lactamaseS Antimicrobial resistance INHIBITOR
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