scholarly journals Development of test panel of beta-lactamases expressed in a common Escherichia coli host background for evaluation of new beta-lactam antibiotics

1995 ◽  
Vol 39 (2) ◽  
pp. 308-313 ◽  
Author(s):  
P. A. Bradford ◽  
C. C. Sanders
2021 ◽  
Vol 38 (3) ◽  
pp. 301-304
Author(s):  
Zahra SADEGHI DEYLAMDEH ◽  
Abolfazl JAFARI SALES

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.


2010 ◽  
Vol 55 (No. 3) ◽  
pp. 119-124 ◽  
Author(s):  
M. Kolar ◽  
J. Bardon ◽  
M. Chroma ◽  
K. Hricova ◽  
T. Stosova ◽  
...  

A major reason for resistance of <I>Enterobacteriaceae</I> to beta-lactam antibiotics is production of ESBLs and AmpC beta-lactamases. As their more detailed description in poultry is unavailable in the Czech Republic, the presented study aimed at assessing their occurrence and molecular characteristics. A total of 154 composite samples from broilers and 150 cloacal swabs from turkeys were examined. Production of ESBLs was detected in seven <I>Escherichia coli</I> isolates and AmpC enzymes in two <I>E. coli</I> isolates. The most frequent ESBL types were CTX-M-1 and SHV-12 and the most common AmpC enzymes were the CMY-2 types.


2020 ◽  
Vol 13 (3) ◽  
pp. 135-140
Author(s):  
HauwaYakubu ◽  
Mahmud Yerima Iliyasu ◽  
Asma’u Salisu ◽  
Abdulmumin Ibrahim Sulaiman ◽  
Fatima Tahir ◽  
...  

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.


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