scholarly journals Characterization of genetic determinants of extended-spectrum cephalosporinases (ESCs) in Escherichia coli isolates from Danish and imported poultry meat

2009 ◽  
Vol 64 (1) ◽  
pp. 207-209 ◽  
Author(s):  
R. D. Bergenholtz ◽  
M. S. Jorgensen ◽  
L. H. Hansen ◽  
L. B. Jensen ◽  
H. Hasman
2011 ◽  
Vol 60 (9) ◽  
pp. 1344-1352 ◽  
Author(s):  
Abouddihaj Barguigua ◽  
Fatima El Otmani ◽  
Mustapha Talmi ◽  
Fatna Bourjilat ◽  
Fatima Haouzane ◽  
...  

2015 ◽  
Vol 78 (5) ◽  
pp. 1018-1023 ◽  
Author(s):  
MEILI XI ◽  
QIAN WU ◽  
XIN WANG ◽  
BAOWEI YANG ◽  
XIAODONG XIA ◽  
...  

Extended-spectrum β-lactamase (ESBL)–producing Escherichia coli strains have been reported worldwide; however, the incidence and characterization of foodborne ESBL-producing E. coli strains have been rarely reported in the People's Republic of China. Among a collection of 659 E. coli isolates recovered from retail foods in Shaanxi Province, People's Republic of China, 223 cefoxitin-resistant and/or cefoperazone-resistant isolates were screened for ESBL production with the double disk diffusion test. The ESBL-producing isolates were characterized for antimicrobial resistance and the presence of blaTEM, blaSHV, and blaCTX-M genes. Isolates with blaCTX-M were further classified by PCR as having blaCTX-M-1, blaCTX-M-2, blaCTX-M-8, blaCTX-M-9, or blaCTX-M-25. One hundred forty-seven isolates were identified as ESBL positive. PCR detection revealed that 146 isolates (99.3%) contained the blaCTX-M gene. Among these isolates, 42 (28.8%) were positive for the enzyme CTX-M-1, 5 (3.4%) for CTX-M-2, and 99 (67.8%) for CTX-M-9. No CTX-M-8 and CTX-M-25 were found in this study. One hundred fifteen isolates (78.2%) were positive for the blaTEM gene, but blaSHV was not detected. Among the 147 ESBL-producing E. coli isolates, 75 (51.0%), 35 (23.8%), and 4 (2.7%) isolates were positive for blaTEM and blaCTX-M-9, blaTEM and blaCTX-M-1, and blaTEM and blaCTX-M-2, respectively. All of the 147 ESBL-producing isolates were resistant to three or more non–β-lactam antibiotics. This study provides evidence that foodborne E. coli can harbor ESBL-encoding genes. Thus, food could be a vehicle for the dissemination of ESBL-producing E. coli strains, a situation that requires surveillance and appropriate management strategies.


Author(s):  
Iswar Anand Senapati ◽  
Rajashree Mishra ◽  
Akshaya Kumar Kundu ◽  
Bidyut Prava Mishra ◽  
Prasana Kumar Rath

2021 ◽  
Vol 25 (2) ◽  
pp. 234-245
Author(s):  
A. V. Bardasheva ◽  
N. V. Fomenko ◽  
T. V. Kalymbetova ◽  
I. V. Babkin ◽  
S. O. Chretien ◽  
...  

72 clinical strains of Klebsiella spp. isolated from samples obtained from humans in Novosibirsk, Russia, were analyzed. Species identification of strains was performed using 16S rRNA and rpoB gene sequences. It was revealed that Klebsiella pneumoniae strains were dominant in the population (57 strains), while the remaining 15 strains were K. grimontii, K. aerogenes, K. oxytoca and K. quasipneumoniae. By molecular serotyping using the wzi gene sequence, K. pneumoniae strains were assigned to twenty-one K-serotypes with a high proportion of virulent K1- and K2-serotypes. It was found that K. pneumoniae strains isolated from the hospitalized patients had a higher resistance to antibiotics compared to the other Klebsiella species. Real-time PCR revealed that the population contained genes of the blaSHV, blaTEM, blaCTX families and the blaOXA-48 gene, which are the genetic determinants of beta-lactam resistance. It has been shown that the presence of the blaCTX sequence correlated with the production of extended-spectrum beta-lactamases, and phenotypic resistance to car-bapenems is due to the presence of the blaOXA-48 gene. At the same time, the carbapenemase genes vim, ndm, kpc, imp were not detected. Among the aminoglycoside resistance genes studied, the aph(6)-Id and aadA genes were found, but their presence did not always coincide with phenotypic resistance. Resistance to fluoroquinolones in the vast majority of strains was accompanied by the presence of the aac(6’)-IB-cr, oqxA, oqxB, qnrB, and qnrS genes in various combinations, while the presence of the oqxA and/or oqxB genes alone did not correlate with resistance to fluoroquinolones. Thus, the detection of blaCTX and blaOXA-48 can be used to quickly predict the production of extended-spectrum beta-lactamases and to determine the resistance of Klebsiella to carbapenems. The detection of the aac(6’)-Ib-cr and/or qnrB/qnrS genes can be used to quickly determine resistance to fluoroquinolones.


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