Molecular Detection of New SHV β-lactamase Variants in Clinical Escherichia coli and Klebsiella pneumoniae Isolates from Egypt

• Published in: Comparative immunology, microbiology and infectious diseases Vol. 60; pp. 35 - 41
• Main Authors: Elmowalid, Gamal A., Ahmad, Adel Attia M., Hassan, Muhammad N., Abd El-Aziz, Norhan K., Abdelwahab, Ashraf M., Elwan, Shymaa I.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2018; Elsevier Science Ltd
• Subjects: Alleles; Amino acid sequence; amino acid sequences; amino acid substitution; Amino acids; Animals; Anti-Bacterial Agents - pharmacology; antibiotic resistance; Bacteria; beta-lactamase; beta-Lactamases - genetics; beta-lactams; Binding Sites; blaSHV alleles; blaSHV binding sites; broiler chickens; Chickens - microbiology; Chicks; Drug Resistance, Multiple, Bacterial - genetics; E coli; Egypt; Egypt - epidemiology; epidemiological studies; Epidemiology; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli Infections - epidemiology; Gene transfer; Genetic relationship; genetic relationships; Humans; Juveniles; Klebsiella; Klebsiella Infections - epidemiology; Klebsiella pneumoniae; Klebsiella pneumoniae - enzymology; Klebsiella pneumoniae - genetics; MDR E. coli; MDR K. pneumoniae; Microbial Sensitivity Tests; Molecules; Multidrug resistance; multiple drug resistance; Mutation; pathogens; Phylogenetics; Phylogeny; Point Mutation; Proteins; sequence analysis; SHV-ESBL; Structure-function relationships; β-Lactam antibiotics; Egypt; MDR E. coli; SHV-ESBL; MDR K. pneumoniae; blaSHV alleles; blaSHV binding sites
• ISSN: 0147-9571; 1878-1667; 1878-1667
• DOI: 10.1016/j.cimid.2018.09.013

•SHV-ESBL was detected in E. coli and K. peumoniae clinical isolates.•blaSHV-10, blaSHV-18, blaSHV-58 and blaSHV-91 were the most predominant variants.•New point mutations were detected in blaSHV and altered blaSHV enzyme binding sites.•blaSHV gene co-transfer was determined among isolates from human and poultry.•These data are valuable in the field of epidemiology and preventive medicine fields. 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.