scholarly journals Phenotypic detection of beta-lactamases production in enterobacteriaceae

2014 ◽  
Vol 142 (7-8) ◽  
pp. 457-463 ◽  
Author(s):  
Ivana Cirkovic ◽  
Ljiljana Pavlovic ◽  
Neda Konstantinovic ◽  
Katarina Kostic ◽  
Snezana Jovanovic ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Automated System ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Clinical Center ◽  
Different Types

Introduction. Beta-lactam antibiotics are the most commonly used antibacterial drugs. However, many bacteria have developed resistance to these antibiotics, and the most common form of resistance is the production of beta-lactamase enzymes. Many members of the Enterobacteriaceae family produce different types of these enzymes. Objective. The aim of this study was to perform phenotypic detection of production and identification of beta-lactamase type in Enterobacteriaceae isolated from different clinical specimens from patients hospitalized in the Clinical Center of Serbia. Methods. The strains of Enterobacteriaceae were collected between November 2011 and January 2012 in the laboratory of the Clinical Center of Serbia. The isolates were identified according to the standard microbiology procedures and confirmed by the Vitek2 automated system. Antimicrobial susceptibility testing was performed by the disk diffusion method, and the phenotypic detection of production and identification of betalactamases was performed according to previously described methodologies. Results. In this study, a total of 172 Enterobacteriaceae strains were isolated. Further testing was performed on 54/145 (37.2%) strains showing decreased susceptibility to beta-lactam antibiotics: 13/85 (15.3%) Escherichia coli, 31/46 (67.4%) Klebsiella pneumoniae and 10/14 (71.4%) Proteus mirabilis. Among them, 40/145 (27.6%) strains produced extended spectrum betalactamases (ESBLs), 9/145 (6.2%) - AmpC, 1/145 (0.7%) - K1 beta-lactamase and 4/145 (2.8%) - carbapenemases. Carbapenemases were predominantly detected in K. pneumoniae (75%). Conclusion. Enterobacteriaceae produce different types of betalactamases, and the most common type in our study was ESBLs. Production of carbapenemases detected in Enterobacteriaceae is also an associated problem.

scholarly journals Phenotypic detection of Carbapenamase among Klebsiella pneumoniae isolated from clinical samples using modified Hodged test

2020 ◽  
Vol 13 (3) ◽  
pp. 135-140
Author(s):  
HauwaYakubu ◽  
Mahmud Yerima Iliyasu ◽  
Asma’u Salisu ◽  
Abdulmumin Ibrahim Sulaiman ◽  
Fatima Tahir ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
University Teaching ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Beta Lactam ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Microbiological Techniques ◽  
Tract Infections

Carbapenemases are microbial enzymes that confer resistance to virtually all available beta-lactam antibiotics and the most frequent carbapenemases are the Klebsiella pneumoniae Carbapenamase (KPC). Detection of carbapenemases is a significant infection control strategy as the enzymes are often associated with extensive antimicrobial resistance, therapeutic failures and mortality associated with infectious diseases. A total of 400 clinical samples were collected from different groups of patients in Abubakar Tafawa Balewa University Teaching Hospital, Bauchi, Nigeria and 118 K. pneumoniae were isolated using standard microbiological techniques. The isolates were subjected to antibiotic susceptibility testing by Kirby-Bauer disc diffusion method, then screened for Carbapenamase production using modified Hodge test. The results indicated that the isolates were resistant to Ampicillin (61.9%), Ceftriaxone (50.8%) and Ceftazidime (50.8%), then Ciprofloxacin (54.2%), but predominantly sensitive to Imipenem (66.9%), Eterpenem (60.2%) and Meropenem (65.3%). It was found that 38 (32.2%) of the isolates phenotypically shows the presence of Carbapenamase, with highest frequency of (40.7%) among patients, mainly adult females with cases of Urinary Tract Infections (UTIs) and the least from wound (11.8%).This study revealed that the isolates produced other beta-lactamases than KPC or variants of Carbapenamase that cannot be detected by modified Hodge test, thus shows low resistance to carbapenems. Therefore further studies is needed to genotypically confirm the presence of KPC in these isolates.

scholarly journals First Global Report of Plasmid-Mediated mcr-1 and Extended-Spectrum Beta-Lactamase-Producing Escherichia coli from Sheep in Portugal

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1403
Author(s):  
Josman Dantas Palmeira ◽  
Marisa Haenni ◽  
Jean-Yves Madec ◽  
Helena Maria Neto Ferreira
Keyword(s):  
One Health ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Colistin Resistance ◽  
Disk Diffusion Method ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Beta Lactam Antibiotics ◽  
Extended Spectrum

Resistances to extended-spectrum cephalosporins (ESC) and colistin are One Health issues since genes encoding these resistances can be transmitted between all sectors of the One Health concept, i.e., human, animal, and the environment. Among food-producing animals, sheep farming has long been overlooked. To fill in this knowledge gap, we looked for ESC- and colistin resistance in 21 faecal samples collected from sheep in one farm in the south of Portugal. ESC-resistant isolates were selected on MacConkey agar plates supplemented with cefotaxime. Susceptibility testing was performed by the disk-diffusion method according to CLSI, while colistin MIC was determined by broth microdilution. ESC- and colistin-resistance genes were identified by PCR, and the clonality of all isolates was assessed by XbaI-PFGE. The replicon content was determined by PCR according to the PCR-based replicon typing (PBRT) scheme. Sixty-two non-duplicate ESC-resistant E. coli isolates were identified, which all presented an extended-spectrum beta-lactamase (ESBL) phenotype, mostly due to the presence of CTX-M genes. One CTX-M-1-producing E. coli was concomitantly colistin-resistant and presented the plasmid-mediated mcr-1 gene. Nearly all isolates showed associated resistances to non-beta-lactam antibiotics, which could act as co-selectors, even in the absence of beta-lactam use. The results showed a high proportion of ESBL-producing E. coli in sheep faeces. Their dissemination was very dynamic, with the spread of successful clones between animals, but also a large diversity of clones and plasmids, sometimes residing in the same animal. This study highlights the need for global surveillance in all food-producing sectors, in order to avoid the dissemination of genes conferring resistance to last-resort antibiotics in human medicine.

scholarly journals Growing Menace of Antibacterial Resistance in Clinical Isolates ofPseudomonas aeruginosain Nepal: An Insight of Beta-Lactamase Production

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Shamshul Ansari ◽  
Rabindra Dhital ◽  
Sony Shrestha ◽  
Sangita Thapa ◽  
Ram Puri ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Opportunistic Pathogen ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Microbiological Methods ◽  
Immunosuppressed Patients

Introduction. Pseudomonas aeruginosais the most frequently isolated organism as it acts as the opportunistic pathogen and can cause infections in immunosuppressed patients. The production of different types of beta-lactamases renders this organism resistant to many commonly used antimicrobials. Therefore, the aim of this study was to document the antibiotic resistance rate inPseudomonas aeruginosaisolated from different clinical specimens.Methods. Pseudomonas aeruginosarecovered was identified by standard microbiological methods. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines and all the suspected isolates were tested for the production of ESBLs, MBLs, and AmpC.Results.Out of total (178) isolates, 83.1% were recovered from the inpatient department (IPD). Majority of the isolates mediated resistance towards the beta-lactam antibiotics, while nearly half of the isolates were resistant to ciprofloxacin. Most of the aminoglycosides used showed resistance rate up to 75% but amikacin proved to be better option. No resistance to polymyxin was observed. ESBLs, MBLs, and AmpC mediated resistance was seen in 33.1%, 30.9%, and 15.7% isolates, respectively.Conclusions. Antibiotic resistance rate and beta-lactamase mediated resistance were high. Thus, regular surveillance of drug resistance is of utmost importance.

scholarly journals Presence of different beta-lactamase classes among clinical isolates of Pseudomonas aeruginosa expressing AmpC beta-lactamase enzyme

2010 ◽  
Vol 4 (04) ◽  
pp. 239-242 ◽  
Author(s):  
Supriya Upadhyay ◽  
Malay Ranjan Sen ◽  
Amitabha Bhattacharjee
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Treatment Options ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Extended Spectrum Beta Lactamase ◽  
Extended Spectrum ◽  
Enzyme Detection

Introduction: Infections caused by Pseudomonas aeruginosa are difficult to treat as the majority of isolates exhibit varying degrees of beta-lactamase mediated resistance to most of the beta-lactam antibiotics. It is also not unusual to find a single isolate that expresses multiple β-lactamase enzymes, further complicating the treatment options. Thus the present study was designed to investigate the coexistence of different beta-lactamase enzymes in clinical isolates of P. aeruginosa. Methodology: A total of 202 clinical isolates of P. aeruginosa were tested for the presence of AmpC beta-lactamase, extended spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) enzyme. Detection of AmpC beta-lactamase was performed by disk antagonism test and a modified three-dimensional method, whereas detection of ESBL was done by the combined disk diffusion method per Clinical and Laboratory Standards Institute (CLSI) guidelines and MBL were detected by the Imipenem EDTA disk potentiation test. Results: A total of 120 (59.4%) isolates were confirmed to be positive for AmpC beta-lactamase. Among them, 14 strains (7%) were inducible AmpC producers. Co-production of AmpC along with extended spectrum beta-lactamase and metallo beta-lactamase was reported in 3.3% and 46.6% isolates respectively. Conclusion: The study emphasizes the high prevalence of multidrug resistant P. aeruginosa producing beta-lactamase enzymes of diverse mechanisms. Thus proper antibiotic policy and measures to restrict the indiscriminative use of cephalosporins and carbapenems should be taken to minimize the emergence of this multiple beta-lactamase producing pathogens.

scholarly journals Vancomycin and high-level aminoglycoside resistance in Enterococcus species

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Seyda Ozarslan Kurtgoz ◽  
Burcin Ozer ◽  
Melek Inci ◽  
Nizami Duran ◽  
Erkan Yula
Keyword(s):  
Vancomycin Resistance ◽  
Automated System ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Aminoglycoside Resistance ◽  
Disk Diffusion Method ◽  
Gradient Diffusion ◽  
Gentamicin Resistance ◽  
Polymerase Chain ◽  
High Level

The aim of the study was to investigate vancomycin and high-level aminoglycoside resistance (HLAR) in <em>Enterococcus</em> species by phenotypic and genotypic methods. A hundred <em>Enterococcus</em> strains were included in the study. Antimicrobial susceptibilities of strains were investigated by automated system, betalactamase production was investigated by nitrocefin disks, vancomycin resistance and HLAR were investigated by gradient diffusion method (GDM) and disk diffusion method, respectively. For detection of vancomycin and high-level gentamicin resistance (HLGR) genes, polymerase chain reaction was used. Teicoplanin linezolid, vancomycin, ampicillin, penicillin are the most susceptible antibiotics and strains were detected not to produce beta lactamase. Vancomycin resistance was detected in ten isolates by automated system and in only five isolates by GDM. Five isolates carrying <em>VanA</em> gene were determined. The ratio of HLGR and high-level streptomycin resistance was found 40 and 63% respectively. <em>aac (6’)-1eaph (2’’)-1a</em> gene was detected in 58% of strains. <em>E. faecium</em> strains were found more resistant to the antibiotics than the other species. Beta lactamase was detected in none of strains. The automated system detected vancomycin resistance in more strains than GDM. Therefore it is concluded that strains, which were detected to be resistant to vancomycin, should be confirmed by GDM. The ratio of <em>VanA</em> gene in strains is consistent with other studies. The HLAR ratio was found in about half of strains. The ratio of<em> aac(6’)-1e-aph(2’’)-1a</em> gene, which is the most reported gene in our country and other countries and one of the HLGR genes investigated in our study, was detected 58%.

scholarly journals ESBL Producers in Gram Negative Isolates from Clinical Samples

2020 ◽  
Vol 14 (3) ◽  
pp. 2027-2032
Author(s):  
Mita D. Wadekar ◽  
J.V. Sathish ◽  
C. Pooja ◽  
S. Jayashree
Keyword(s):  
Treatment Options ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Gram Negative ◽  
Extended Spectrum Beta Lactamase ◽  
Beta Lactam Antibiotics ◽  
Esbl Producers

Resistance to beta lactam antibiotics is the most common cause for beta-lactamase production. Increasing number of extended spectrum beta-lactamase (ESBL) producers has reduced the treatment options which resulted in emergence of multidrug resistant strains, treatment failure and hence increased mortality. To detect phenotypically, ESBL producers in Gram negative isolates from different samples and to know their susceptibility pattern. A retrospective study of Gram negative isolates was conducted. Total of 521 isolates were isolated from various samples. They were processed and identified by standard procedures. The antibiotic susceptibility testing was performed by Kirby- Bauer disc diffusion method using CLSI guidelines. ESBL was detected by combination disk test. A total of 521 Gram negative isolates were isolated which included E. coli, Klebsiella pneumoniae, Citrobacter spp., Enterobacter spp., Proteus spp. and Acinetobacter spp. Pseudomonas aeruginosa. Of 521 isolates tested, ESBL was detected in 329 (63.1%) isolates. These isolates showed maximum susceptibility to piperacillin- tazobactam (86%) followed by imipenem (78.4%), amikacin (63.5%), cotrimoxazole (54.4%), ciprofloxacin (51%), amoxi-clav (44.9%), cefepime (44.1%), gentamicin (38.9%), cefoxitin (34.9%) and ampicillin (19.1%). ESBL producers which are resistant to beta lactam antibiotics have become a major problem. Detection of these beta-lactamase enzymes by simple disk method and its reporting will help clinicians in prescribing proper antibiotics.

scholarly journals Evaluation of the presence of AmpC (FOX) beta-lactamase gene in clinical strains of Escherichia coli isolated from hospitalized patients in Tabriz, Iran

2021 ◽  
Vol 38 (3) ◽  
pp. 301-304
Author(s):  
Zahra SADEGHI DEYLAMDEH ◽  
Abolfazl JAFARI SALES
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Hospitalized Patients ◽  
Disk Diffusion ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactamases ◽  
Clinical Strains ◽  
Beta Lactam Antibiotics ◽  
Lactamase Gene

Beta-lactamases are the most common cause of bacterial resistance to beta-lactam antibiotics. AmpC-type beta-lactamases hydrolyze cephalosporins, penicillins, and cephamycins. Therefore, the study aims was to determine antibiotic resistance and to investigate the presence of AmpC beta-lactamase gene in clinical strains of Escherichia coli isolated from hospitalized patients in Tabriz. In this cross-sectional descriptive study, 289 E. coli specimens were collected from clinical specimens. Disk diffusion method and combined disk method were used to determine the phenotype of extended spectrum β-Lactamase producing (ESBLs) strains. Then PCR was used to evaluate the presence of AmpC (FOX) beta-lactamase gene in the strains confirmed in phenotypic tests. Antibiotic resistance was also determined using disk diffusion by the Kibry-Bauer method. A total of 121 isolates were identified as generators of beta-lactamase genes. 72 (59.5 %) isolates producing ESBL and 49 (40.5 %) isolates were identified as AmpC generators. In the PCR test, 31 isolates contained the FOX gene. The highest resistance was related to the antibiotics amoxicillin (76.12%), ceftazidime (70.24%) and nalidixic acid (65.05%). The results indicate an increase in the prevalence of beta-lactamase genes and increased resistance to beta-lactam antibiotics, which can be the result of improper use of antibiotics and not using antibiotic susceptibility tests before starting treatment. Also, using phenotypic and molecular diagnostic methods such as PCR together can be very useful.

scholarly journals Frequency and antimicrobial resistance of bacteria isolated from oral and topical medicaments from Hilla, Iraq

2012 ◽  
Vol 6 (06) ◽  
pp. 489-494 ◽  
Author(s):  
Alaa Hani Al-Charrakh
Keyword(s):  
High Resistance ◽  
Antimicrobial Agents ◽  
Pharmaceutical Products ◽  
High Rate ◽  
Diffusion Method ◽  
Bacterial Isolates ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
Beta Lactam Antibiotics

Introduction: The presence of microorganisms in pharmaceuticals is undesirable because they may cause spoilage of the product and may present an infection hazard to the consumers or patients.  Methodology: A total of 102 samples of oral and topical non-sterile pharmaceutical products were collected at random from different drug houses and pharmacies in Iraq, to investigate the microbial contamination of these products. Bacterial isolates recovered from these medicaments were subjected to susceptibility testing against various antibiotics by disk diffusion method according to Clinical and Laboratory Standards (CLSI) guidelines. Results: The results revealed that the occurrence of Gram-positive bacteria was in oral and topical medicaments while Gram-negative bacteria were only detected in topical medicaments. More than 58% of Bacillus isolates were resistant to lincomycin and Bacillus mycoides isolates were resistant to beta-lactam antibiotics and trimethoprim-sulfamethoxazole. Staphylococcus spp. showed a relatively high resistance to ampicillin, amoxicillin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole. S. epidermidis had the highest number of multi-resistant isolates. Furthermore, 87.5% of isolated Gram-negative rods showed high resistance to beta-lactam antibiotics and 75% of them were highly resistant to erythromycin. One isolate of Pseudomonas aeruginosa was the most resistant among all Gram-negative rod isolates. Conclusion: The high rate of resistance to antimicrobial agents of bacterial isolates recovered from oral and topical medicaments in this study may indicate a widespread antibiotic resistance among bacteria isolated from different sources, including those of anthropological and environmental origin. 

scholarly journals Biochemical Characterization of QPX7728, a New Ultrabroad-Spectrum Beta-Lactamase Inhibitor of Serine and Metallo-Beta-Lactamases

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Ruslan Tsivkovski ◽  
Maxim Totrov ◽  
Olga Lomovskaya
Keyword(s):  
High Efficiency ◽  
Biochemical Characterization ◽  
Molar Ratio ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Content Type ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Class D ◽  
Extended Spectrum Beta Lactamases

ABSTRACT QPX7728 is a new ultrabroad-spectrum inhibitor of serine and metallo-beta-lactamases (MBLs) from a class of cyclic boronates that gave rise to vaborbactam. The spectrum and mechanism of beta-lactamase inhibition by QPX7728 were assessed using purified enzymes from all molecular classes. QPX7728 inhibits class A extended-spectrum beta-lactamases (ESBLs) (50% inhibitory concentration [IC50] range, 1 to 3 nM) and carbapenemases such as KPC (IC50, 2.9 ± 0.4 nM) as well as class C P99 (IC50 of 22 ± 8 nM) with a potency that is comparable to or higher than recently FDA-approved beta-lactamase inhibitors (BLIs) avibactam, relebactam, and vaborbactam. Unlike those other BLIs, QPX7728 is also a potent inhibitor of class D carbapenemases such as OXA-48 from Enterobacteriaceae and OXA enzymes from Acinetobacter baumannii (OXA-23/24/58, IC50 range, 1 to 2 nM) as well as MBLs such as NDM-1 (IC50, 55 ± 25 nM), VIM-1 (IC50, 14 ± 4 nM), and IMP-1 (IC50, 610 ± 70 nM). Inhibition of serine enzymes by QPX7728 is associated with progressive inactivation with a high-efficiency k2/K ranging from 6.3 × 104 (for P99) to 9.9 × 105 M−1 s−1 (for OXA-23). This inhibition is reversible with variable stability of the QPX7728-beta-lactamase complexes with target residence time ranging from minutes to several hours: 5 to 20 min for OXA carbapenemases from A. baumannii, ∼50 min for OXA-48, and 2 to 3 h for KPC and CTX-M-15. QPX7728 inhibited all tested serine enzymes at a 1:1 molar ratio. Metallo-beta-lactamases NDM, VIM, and IMP were inhibited by a competitive mechanism with fast-on–fast-off kinetics, with Kis of 7.5 ± 2.1 nM, 32 ± 14 nM, and 240 ± 30 nM for VIM-1, NDM-1, and IMP-1, respectively. QPX7728’s ultrabroad spectrum of BLI inhibition combined with its high potency enables combinations with multiple different beta-lactam antibiotics.

Sign in / Sign up

Export Citation Format

Share Document