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Artificial Enzymes
Published in Yubing Xie, The Nanobiotechnology Handbook, 2012
James A. Stapleton, Agustina Rodriguez-Granillo, Vikas Nanda
Another approach to generating new activity combined rational design and directed evolution to introduce β-lactamase activity into a glyoxalase II (GlyII; αβ/βα) metallo-hydrolase (Park et al. 2006). The C-terminal domain of the parent enzyme was removed to relieve steric constraints, and substrate- and metal cofactor-binding loops derived from a sequence alignment of metallo β-lactamase (MBL) enzymes were inserted into the scaffold along with targeted mutations that introduced catalytic residues. This rationally designed scaffold served as the parent for random directed evolution by error-prone polymerase chain reaction (PCR) and DNA shuffling (Stemmer 1994), resulting in the isolation of a mutant that could support E. coli growth in the presence of a 1.0 μg/mL concentration of the lactam antibiotic cefotaxime. The designed scaffold modifications in this study were inspired by MBL, which belongs to the same structural superfamily as GlyII and provided an example solution for the design of a β-lactamase. While the successful conversion of GlyII into a β-lactamase is remarkable, the application of this approach to the generation of novel artificial enzymes is limited by the requirement for a homologous natural enzyme.
Green Chemistry and Its Applications in Water Remediation
Published in Sanjay K. Sharma, Bioremediation, 2019
S. Atalay, G. Ersöz, Sanjay K. Sharma
Leon et al. in their study focused on the degradation of the antibiotic cefotaxime under sunlight (which is simulated) radiation using heterogeneous catalysts with titanium dioxide (TiO2) and zinc oxide (ZnO) in solutions. They concluded that the studied parameters, pH and initial catalyst loading have an important role in antibiotic degradation in both TiO2 and ZnO suspensions. In addition, the role of photogenerated holes, hydroxyl, and superoxide anion radicals on cefotaxime degradation was investigated to determine the reaction mechanism. Antibiotic removal was described by the pseudo-first-order reaction kinetic model regardless of the catalyst type (León et al., 2017).
The detection of extensive-spectrum beta-lactamase (ESBL) producing genes in Escherichia coli strains, isolated from apparently healthy and enteric pet birds
Published in International Journal of Environmental Health Research, 2023
Elaheh Miranzadeh Mahabadi, Majid Gholami-Ahangaran
Examination of antibiotic resistance in EPE strains showed that these strains showed high resistance to cefotaxime. These strains also contained mainly the CTX-M gene. The presence of high resistance as well as the presence of the CTX-M gene can be related to the presence of this ESBL gene and resistance to cefotaxime, as several reports of the presence of CTX-M gene and the presence of resistance to cefotaxime have been reported. Botelho et al. (2020) reported 58% resistance to cefotaxime in EPE strains isolated from 16 frozen chicken carcasses. Li et al. (2010) reported resistance to cefotaxime in CTX-containing E. coli strains isolated from the cloacal swab obtained from broiler chickens in various Chinese farms ranging from 2% to 90%. Resistance to cefotaxime in CTX-producing strains indicates increasing growth and spread of cefotaxime resistance among E. coli strains. The lack of use of human drugs, especially ceftazidime and cefotaxime in the treatment of infectious diseases of pet birds and the existence of resistance to these antibiotics increases the probability of transmission of resistance genes and requires greater care to prevent infectious diseases by antibiotic alternatives (Gholami‐ahangaran et al. 2022). in the pet birds. This strategy can prevent the progress of antibiotic resistance against broad-spectrum antibiotics used against human infectious diseases.
Detection of extended spectrum beta-lactamase genes in strains of Escherichia coli and Klebsiella pneumoniae isolated from recreational water and tertiary hospital waste water in Zaria, Nigeria
Published in International Journal of Environmental Health Research, 2022
H. I. Atta, S. M. Idris, B. H. Gulumbe, O. J. Awoniyi
The Gram reaction and biochemical tests of the isolates are as shown in Table 1. Twenty-two isolates of E. coli and Klebsiella pneumoniae were identified, seventeen (17) from the hospital wastewater and five (5) from the recreational water body. E. coli had a higher occurrence 13 (59.1%) than Klebsiella pneumoniae 9(40.9%). The antibiotic susceptibility test (Table 3) revealed that a number of isolates have complete resistance (no zone of inhibition) to both Cefotaxime and Ceftazidime, which was mostly observed towards the antibiotic, Ceftazidime. The double disk synergy test for confirmation of ESBL production is as shown in Table 2. Of the 22 isolates isolated from both hospital wastewater and recreational water, 6(27.2%) were found to be ESBL-producers, 3 (50%) were E. coli and 3(50%) were Klebsiella pneumoniae (Figure 1). The only strain of Klebsiella pneumoniae isolated from the recreational water did not produce ESBL.
High rates of antibiotic resistance and biofilm production in Escherichia coli isolates from food products of animal and vegetable origins in Tunisia: a real threat to human health
Published in International Journal of Environmental Health Research, 2022
Souhir Badi, Mohamed Salah Abbassi, Mejdi Snoussi, Rim Werheni, Salah Hammami, Rasha Maal-Bared, Abdennaceur Hassen
Interestingly, no ESBL-producing isolates were detected. Worldwide ESBL-producing E. coli has been increasingly reported in animals, humans and environmental samples [Bush and Bradford (2020); Sghaier et al. (2019), Smet et al. (2009)]. In Tunisia, high rates of ESBL- producing E. coli isolates from livestock and food products of animal origin and vegetables have been reported by many studies [Ben Said et al., (2015); Hassen et al. (2020); Sghaier et al. (2019)]. Data about ESBL-producing E. coli of food products from neighbor countries are scarce; however, it seems also that ESBL-producing E. coli is a growing problem. In an Algerian study, 27.5% of ground beef samples were contaminated by ESBL-producing isolates [Rebbah et al. (2018)]. However, in one Egyptian study, E. coli ESBL producers were isolated from 14.5% of one hundred retail chicken meat samples [Abdallah et al. (2015)]. There were no differences in antibiotic resistance rates between vegetables and animal isolates except for gentamicin and cefotaxime (p < 0.001). The MAR index average value was higher for vegetable isolates (0.91) than for animal isolates. This finding implies that vegetables harbored more multiresistant isolates than food products of animal origin. This result highlights the potential importance of vegetables as vector of multiresistant bacteria, as previously reported [Costerton (1999); Rasheed et al. (2014)]. This might be linked to contaminated waste water containing pathogenic bacteria (urban water effluents) used in irrigation in many regions in Tunisia.