Occurrence of multidrug resistance to oral antibiotics among Escherichia coli urine isolates from outpatient departments in Germany: Extended-spectrum β-lactamases and the role of fosfomycin

2014 ◽  
Vol 44 (4) ◽  
pp. 295-300 ◽  
Author(s):  
Michael Kresken ◽  
Yvonne Pfeifer ◽  
Dieter Hafner ◽  
Rebecca Wresch ◽  
Barbara Körber-Irrgang
2008 ◽  
Vol 53 (1) ◽  
pp. 323-326 ◽  
Author(s):  
Hedi Mammeri ◽  
Moreno Galleni ◽  
Patrice Nordmann

ABSTRACT Two AmpC variants harboring the S287N substitution were obtained by mutagenesis from cephalosporinases representative of the phylogenetic groups A and B2 of Escherichia coli. Their biochemical characterization revealed that the S287N replacement led to an important increase in the catalytic efficiency toward extended-spectrum cephalosporins in the AmpC β-lactamase of group A only.


2021 ◽  
Vol 37 (2) ◽  
pp. 56-73
Author(s):  
F Iseghohi ◽  
J.C Igwe ◽  
M Galadima ◽  
A.F Kuta ◽  
A.M Abdullahi ◽  
...  

Globally, urinary tract infections are one of the most common infections in need of urgent clinical attention. The prevalence of extended spectrum beta-lactamases (ESBL)- producing Escherichia coli isolated from urine samples of some UTI patients and s of apparently healthy individuals in Minna, Nigeria, is investigated. Standard microbiological techniques were used to conduct this study. A total of 170 catch midstream urine samples submitted to the Medical Microbiology Laboratories of 4 different hospitals (and samples from healthy individuals) were randomly collected for 5 months and examined for microbial growths. Female patients (65.9%) submitted more urine samples for UTI test than their male counterpart (34.1%). The age ranges of 21 -30 (26.5%) and 31 - 40 (25.3%) had the highest percentages of infection rate while those within the ages 1- 10 (3.5%) and ≥ 71 (2.3%) were the least infected. This study observed a prevalence of 23.5% of E. coli in Minna metropolis and a significant number (30%) of healthy individuals (HI) was observed to harbor the E. coli in their urine. The isolates were highly susceptible to Gentamicin (65%), Ofloxacin (65%), Tetracycline (62.5%), Cotrimoxazole (62.5%), and Streptomycin (57.5%). Mildly susceptible to Pefloxacin (37.5%), Chloramphenicol (37.5%), and Ciprofloxacin (35%). There were significant resistance to most of the beta-lactames tested [Cefuroxime (80%), Amoxicillin (42.5%), Augmentin (40), Cefotaxime (20%) and Ceftaxidime (7.5%)]. Two of the isolates were resistant to all the 13 antibiotics tested; 70% (28) of the isolates had multiple antibiotics resistance index (MARI) ≥0.3. Multidrug resistance was expressed in 37.5% of the isolates tested. The study showed a vast resistant pool in the environment. Only 25% of the E. coli isolated from the urine samples produced beta-lactamases phenotypically, most of which expressed resistance to more than 5 of the antibiotics tested and had MARI of ≥ 0.5. Further evaluation showed that 25% (10/40) of the E. coli isolated from the UTI patients in Minna, Nigeria, were ESBL- producers and could harbor one or two of the genes. TEM gene was expressed in 70% (7) of the isolates that produced ESBL phenotypically, 60% 6) harbored CTXM gene, 20% (2) had the OXA gene while none of the bacteria harbored the SHV gene. The study established a 5.9% ESBL prevalence among the E. coli isolated from UTI in the environment studied. This study established that E. coli is one of the prevalent bacteri urea majorly isolated from UTI patients in Minna. The prevalent E. coli are multidrug resistant and could harbor more than one ESBL gene . keywords: Escherichia coli, Minna, UTI, ESBL, Multidrug resistance


1996 ◽  
Vol 40 (4) ◽  
pp. 1050-1052 ◽  
Author(s):  
O Lomovskaya ◽  
F Kawai ◽  
A Matin

The mcb operon (which is responsible for microcin B17 production) and the emr operon (which encodes a multidrug resistance pump) share a common negative regulator, EmrR. Nevertheless, compounds that induce the emr operon repress the mcb operon. The pump dedicated to microcin B17 extrusion can also protect the calls against sparfloxacin and other toxic compounds.


Author(s):  
Mohammad Faheem ◽  
Charles J. Zhang ◽  
Monica N. Morris ◽  
Juergen Pleiss ◽  
Peter Oelschlaeger

Nonsynonymous mutations are well documented in TEM β-lactamases. The resulting amino acid changes often alter the conferred phenotype from broad spectrum (2b) conferred by TEM-1 to extended spectrum (2be), inhibitor resistant (2br), or both extended spectrum and inhibitor resistant (2ber). The encoding blaTEM genes also deviate in numerous synonymous mutations, which are not well understood. blaTEM-3 (2be), blaTEM-33 (2br), and blaTEM-109 (2ber) were studied in comparison to blaTEM-1. blaTEM-33 was chosen for more detailed studies, because it deviates from blaTEM-1 by a single nonsynonymous mutation and three additional, synonymous mutations. Genes encoding the enzymes with only nonsynonymous or all, including synonymous, mutations plus all permutations between blaTEM-1 and blaTEM-33 were expressed in Escherichia coli cells. In disc diffusion assays, genes encoding TEM-3, TEM-33, and TEM-109 with all synonymous mutations resulted in higher resistance levels than genes without synonymous mutations. Disc diffusion assays with the 16 genes carrying all possible nucleotide change combinations between blaTEM-1 and blaTEM-33 indicated different susceptibilities for different variants. Nucleotide BLAST searches did not identify genes without synonymous mutations but some without nonsynonymous mutations. Energies of possible secondary mRNA structures calculated with mfold are generally higher with synonymous mutations, suggesting that their role could be to destabilize the mRNA and facilitate its unfolding for efficient translation. In summary, our data indicate that transitions from blaTEM-1 to other variant genes by simply acquiring the nonsynonymous mutations is not favored. Instead, synonymous mutations seem to support the transition to other variant genes with nonsynonymous mutations leading to different phenotypes.


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