Molecular Detection of New SHV β-lactamase Variants in Clinical Escherichia coli and Klebsiella pneumoniae Isolates from Egypt
Autor: | Ashraf M. Abdelwahab, Adel Attia M. Ahmad, Gamal A. El-mowalid, Shymaa I. Elwan, Norhan K. Abd El-Aziz, Muhammad N. Hassan |
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Rok vydání: | 2018 |
Předmět: |
0301 basic medicine
Klebsiella pneumoniae 030106 microbiology Immunology Genetic relationship Microbial Sensitivity Tests Biology medicine.disease_cause Microbiology beta-Lactamases 03 medical and health sciences Phylogenetics Drug Resistance Multiple Bacterial polycyclic compounds medicine Escherichia coli Immunology and Allergy Animals Humans Point Mutation Peptide sequence Alleles Escherichia coli Infections Phylogeny chemistry.chemical_classification Binding Sites General Veterinary Phylogenetic tree Point mutation General Medicine biochemical phenomena metabolism and nutrition biology.organism_classification Amino acid Anti-Bacterial Agents Klebsiella Infections 030104 developmental biology Infectious Diseases chemistry Egypt Chickens |
Zdroj: | Comparative immunology, microbiology and infectious diseases. 60 |
ISSN: | 1878-1667 |
Popis: | The emergence of multidrug-resistant (MDR) pathogens was reported worldwide. Herein, SHV extended-spectrum β-lactamase (SHV-ESBL) variants detection was investigated in MDR E. coli and K. pneumoniae isolates recovered from human subjects (n = 144), one day-old chicks (n = 36) and broiler clinical samples (n = 90). All examined samples were positive for E. coli (n = 246/270; 91.11%) and Klebsiella pneumoniae (n = 24/270; 8.89%). Antimicrobial susceptibility testing was performed on E. coli and K. pneumoniae. SHV-ESBL producing isolates were defined followed by SHV-ESBL amino acids sequence and proteins structure-function analyses. Phylogenetic analysis of 11 MDR isolates resistant to at least 6 β-lactams was designed to determine their genetic relationship with those previously identified in Egypt. SHV-ESBL variants were detected in 28% and 16% of E. coli and K. pneumoniae isolates, respectively. Among the 11 SHV-ESBL producing isolates, one isolate displayed 100% blaSHV-12 similarity with three point mutations, while the other 10 isolates displayed amino acid substitutions at previously non-reported sites. Amino acid sequence analyses of these 10 isolates displayed 96–100% identity to blaSHV-10 (2 isolates with 3–6 point mutations), blaSHV-18 (one isolate with 4 point mutations), blaSHV-58 (4 isolates with 4–5 point mutations), and blaSHV-91 (3 isolates with 3–7 point mutations). These mutations altered SHV-enzyme pocket dimensions and its binding sites chargeability. The blaSHV phylogeny analysis revealed occurrence of variants in closely related lineages with blaSHV-5 and blaSHV-12 with possibility of blaSHV gene transfer between human and birds. The occurrence of these variants in Egypt could help in epidemiological studies and could explain the emergent resistance to β-lactams. |
Databáze: | OpenAIRE |
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