scholarly journals Distribution of beta-lactamases in Acinetobacter baumannii clinical isolates and the effect of Syn 2190 (AmpC inhibitor) on the MICs of different beta-lactam antibiotics

2002 ◽  
Vol 50 (2) ◽  
pp. 261-264 ◽  
Author(s):  
C. Danes
Keyword(s):  
Acinetobacter Baumannii ◽  
Clinical Isolates ◽  
Beta Lactam ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics

The research of the susceptibility to antimicrobial medicines of Acinetobacter baumannii as pathogens of infectious complications in patients with hard burns

2018 ◽  
Vol 22 (2) ◽  
pp. 306-310
Author(s):  
V.I. Nahaichuk ◽  
O.A. Nazarchuk ◽  
N.I. Osadchuk ◽  
D.V. Palyi ◽  
H.H. Nazarchuk ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Local Treatment ◽  
Early Period ◽  
Infectious Complications ◽  
Clinical Isolates ◽  
Beta Lactam ◽  
Clinical Strains ◽  
Beta Lactam Antibiotics ◽  
Microbiological Methods ◽  
Amoxicillin Clavulanate

Antibiotic-resistant strains of Acinetobacter baumannii has become yet recognized one of the most leading causative pathogens of infectious complications in patients with severe burns. This greatly complicates the treatment of such patients and requires in-depth study with a prognostic determination of the dynamics of antimicrobial efficacy of antibacterial agents. The aim — to study the susceptibility to antibiotics in clinical isolates of A. baumannii, pathogens of infectious complications in patients with hard burns. From patients (n=435) with burns of the 2ndb – 3rd degree, isolates of A.baumannii were received in early period after burn trauma before antibiotic therapy. Patients who participated in the study received standard surgical, complex general and local treatment in the required volume according to the protocols for the treatment of this disease. In total, 222 clinical strains of A.baumannii were isolated and identified during 2011–2016. The susceptibility of clinical strains A.baumannii to the following beta-lactam antibiotics: ampicillin-sulbactam, amoxicillin-clavulanate, piperacillin-tazobactam, cefoperazone-sulbactam, imipenem, meropenem, was determined by standard microbiological methods (qualitative disco-diffusion and quantitative double dilution methods). Using statistical methods, mathematical and analytical prognosis of the real sensitivity of A. baumannii strains to these antibiotics with the use of licensed computer programs “STATISTICA 7” was carried out; “Matlab 7.11”. The results of the study demonstrated a low susceptibility of clinical strains of A.baumannii to the studied beta-lactam antibiotics. The change in the antibiotic susceptibility profile of A.baumannii in 2011–2016 was established. Thus, the vast majority of strains were of low susceptibility to cefoperazone-sulbactam (55,6%), imipenem (57,1%) and meropenem (52,8%). In the dynamics, the prognostic decrease of the sensitivity in clinical isolates of Acinetobacteria to the antibiotics has been proved. The susceptibility of A.baumannii to amoxicillin-clavulanate was consistently low (less than 13,3%), and significantly decreased to cefoperazone–sulbactam (25,0%). The resistance of this pathogen to imipenem (up to 75,0%), meropenem (up to 84,3%) has been established to increase. At the same time, the gradual restoration of the susceptibility of A.baumannii to ampicillin–sulbactam (from 3,4% to 70,2%) was determined. The A.baumannii, pathogens of infectious complications in patients with burns, were characterized by a decrease in sensitivity to inhibitor-protected penicillins, carbapenems except ampicillin–sulbactam, that proved their low effectiveness against this pathogen.

scholarly journals Impact of Intrinsic Resistance Mechanisms on Potency of QPX7728, a New Ultrabroad-Spectrum Beta-Lactamase Inhibitor of Serine and Metallo-Beta-Lactamases in Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Olga Lomovskaya ◽  
Kirk Nelson ◽  
Debora Rubio-Aparicio ◽  
Ruslan Tsivkovski ◽  
Dongxu Sun ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Resistance Mechanisms ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Intrinsic Resistance ◽  
Content Type ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Lactamase Inhibitor

ABSTRACT QPX7728 is an ultrabroad-spectrum boronic acid beta-lactamase inhibitor that demonstrates inhibition of key serine and metallo-beta-lactamases at a nanomolar concentration range in biochemical assays with purified enzymes. The broad-spectrum inhibitory activity of QPX7728 observed in biochemical experiments translates into enhancement of the potency of many beta-lactams against strains of target pathogens producing beta-lactamases. The impacts of bacterial efflux and permeability on inhibitory potency were determined using isogenic panels of KPC-3-producing isogenic strains of Klebsiella pneumoniae and Pseudomonas aeruginosa and OXA-23-producing strains of Acinetobacter baumannii with various combinations of efflux and porin mutations. QPX7728 was minimally affected by multidrug resistance efflux pumps either in Enterobacteriaceae or in nonfermenters, such as P. aeruginosa or A. baumannii. Against P. aeruginosa, the potency of QPX7728 was further enhanced when the outer membrane was permeabilized. The potency of QPX7728 against P. aeruginosa was not affected by inactivation of the carbapenem porin OprD. While changes in OmpK36 (but not OmpK35) reduced the potency of QPX7728 (8- to 16-fold), QPX7728 (4 μg/ml) nevertheless completely reversed the KPC-mediated meropenem resistance in strains with porin mutations, consistent with the lesser effect of these mutations on the potency of QPX7728 compared to that of other agents. The ultrabroad-spectrum beta-lactamase inhibition profile, combined with enhancement of the activity of multiple beta-lactam antibiotics with various sensitivities to the intrinsic resistance mechanisms of efflux and permeability, indicates that QPX7728 is a useful inhibitor for use with multiple beta-lactam antibiotics.

scholarly journals Cloning and nucleotide sequence analysis of a gene encoding an OXA-derived beta-lactamase in Acinetobacter baumannii.

1997 ◽  
Vol 41 (12) ◽  
pp. 2757-2759 ◽  
Author(s):  
J Vila ◽  
M Navia ◽  
J Ruiz ◽  
C Casals
Keyword(s):  
Sequence Analysis ◽  
Nucleotide Sequence ◽  
Acinetobacter Baumannii ◽  
Clinical Strain ◽  
Nucleotide Sequence Analysis ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Gene Encoding ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics

A clinical strain of Acinetobacter baumannii (strain Ab41) that was resistant to all beta-lactam antibiotics tested except ceftazidime, ceftriaxone, ceftizoxime, and imipenem produced three beta-lactamases: a presumptive chromosomal cephalosporinase, a TEM-1-like beta-lactamase (pI 5.4), and a novel OXA-derived beta-lactamase named OXA-21 (pI 7.0). The gene encoding OXA-21 was located in an integron. The nucleotide sequence showed three mutations compared with the sequence of OXA-3, with two being silent; the nonsilent mutation generated a substitution of Ile-217 to Met.

scholarly journals In-vitro activities of cefepime and other beta-lactam antibiotics against clinical isolates from a Colombian teaching hospital

1998 ◽  
Vol 42 (4) ◽  
pp. 550-552 ◽  
Author(s):  
S. Mattar ◽  
L. Sanchez ◽  
D. Perez ◽  
A. Arango ◽  
R. Parodi ◽  
...  
Keyword(s):  
Teaching Hospital ◽  
Clinical Isolates ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics

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.

Upregulation of the clpB gene in response to heat shock and beta-lactam antibiotics in Acinetobacter baumannii

2019 ◽  
Vol 47 (2) ◽  
pp. 1499-1505
Author(s):  
Waleska Yana Lazaretti ◽  
Elaine Luzia dos Santos ◽  
José Luis da-Conceição Silva ◽  
Marina Kimiko Kadowaki ◽  
Rinaldo Ferreira Gandra ◽  
...  
Keyword(s):  
Heat Shock ◽  
Acinetobacter Baumannii ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics

Stigmasterol: An adjuvant for beta lactam antibiotics against beta-lactamase positive clinical isolates

Steroids ◽  
2017 ◽  
Vol 128 ◽  
pp. 68-71 ◽  
Author(s):  
Tong Woei Yenn ◽  
Muhammad Arslan Khan ◽  
Nur Amiera Syuhada ◽  
Leong Chean Ring ◽  
Darah Ibrahim ◽  
...  
Keyword(s):  
Clinical Isolates ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics

scholarly journals Extended-spectrum beta-lactamases producing Escherichia coli and Klebsiella pneumoniaei: A Multi-centric Study Across Karnataka

2014 ◽  
Vol 6 (01) ◽  
pp. 007-013 ◽  
Author(s):  
Sridhar PN Rao ◽  
Prasad Subba Rama ◽  
Vishwanath Gurushanthappa ◽  
Radhakrishna Manipura ◽  
Krishna Srinivasan
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolates ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Esbl Production ◽  
Beta Lactamases ◽  
E Coli ◽  
Karnataka State ◽  
Extended Spectrum Beta Lactamases ◽  
Esbl Producers

ABSTRACT Background: There are sporadic reports on detection of extended-spectrum beta-lactamases (ESBL) producers from Karnataka; hence, this is a first multicentric study across Karnataka state to determine the prevalence of ESBL production among clinical isolates of Escherichia coli and Klebsiella pneumoniaei. Aims and objectives: To determine the prevalence of ESBL producing clinical isolates of E. coli and K. pneumoniae from five geographically distributed centers across Karnataka, to study the susceptibility of ESBL producing isolates to other beta-lactam and beta-lactam-beta-lactamase inhibitors and to demonstrate transferability of plasmids coding for ESBL phenotype. Materials and Methods: Two hundred isolates of E. coli and K. pneumoniae each were collected from each of the five centers (Bellary, Dharwad, Davangere, Kolar and Mangalore). They were screened for resistance to screening agents (ceftazidime, cefotaxime, ceftriaxone, aztreonam) and positive isolates were confirmed for ESBL production by test described by Clinical and Laboratory Standards Institute . Co-production of ESBL and AmpC beta-lactamase was identified by using amino-phenylboronic acid disk method. Susceptibility of ESBL producers to beta-lactam antibiotics and beta-lactamase inhibitors was performed. Transferability of plasmids was performed by conjugation experiment. Results: Overall prevalence of ESBL production among E. coli and K. pneumoniae across five centers of the state was 57.5%. ESBL production was found to be 61.4% among E. coli and 46.2% among K. pneumoniae. ESBL production was significantly more among E. coli than K. pneumoniae. Significant variations in distribution of ESBL across the state was observed among E. coli isolates, but not among K. pneumoniae isolates. All ESBL producers demonstrated minimum inhibitory concentration levels ≥2 μg/ml towards cefotaxime, ceftazidime and ceftriaxone. Conclusion: Overall prevalence of ESBL production among clinical isolates of E. coli and K. pneumoniae across Karnataka state was high. The prevalence of ESBL production was significantly higher with E. coli than K. pneumoniae isolates. Higher rates of resistance to ceftriaxone and cefotaxime than to ceftazidime suggests the possibility of presence of CTX-M type ESBLs. Of all the beta-lactam/beta-lactamase inhibitor combinations tested, cefepime-tazobactam demonstrated highest in-vitro activity against ESBL producers. There was no statistical difference in the transferability of plasmids among E. coli and K. pneumoniae.

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