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. 2024 Dec;52(6):2399-2414.
doi: 10.1007/s15010-024-02297-8. Epub 2024 Jun 2.

Phenotypic and molecular characterization of extended spectrum- and metallo- beta lactamase producing Pseudomonas aeruginosa clinical isolates from Egypt

Eva A Edward  1 , Marwa R El Shehawy  2 , Alaa Abouelfetouh  2   3 , Elsayed Aboulmagd  2   4
Affiliations

Phenotypic and molecular characterization of extended spectrum- and metallo- beta lactamase producing Pseudomonas aeruginosa clinical isolates from Egypt

Eva A Edward et al. Infection. 2024 Dec.

Abstract

Background: Antimicrobial resistance among Pseudomonas aeruginosa (P. aeruginosa), a leading cause of nosocomial infections worldwide, is escalating. This study investigated the prevalence of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) among 104 P. aeruginosa clinical isolates from Alexandria Main University Hospital, Alexandria, Egypt.

Methods: Antimicrobial susceptibility testing was performed using agar dilution technique, or broth microdilution method in case of colistin. ESBL and MBL prevalence was assessed phenotypically and genotypically using polymerase chain reaction (PCR). The role of plasmids in mediating resistance to extended-spectrum β-lactams was studied via transformation technique using plasmids isolated from ceftazidime-resistant isolates.

Results: Antimicrobial susceptibility testing revealed alarming resistance rates to carbapenems, cephalosporins, and fluoroquinolones. Using PCR as the gold standard, phenotypic methods underestimated ESBL production while overestimating MBL production. Eighty-five isolates (81.7%) possessed only ESBL encoding genes, among which 69 isolates harbored a single ESBL gene [blaOXA-10 (n = 67) and blaPER (n = 2)]. Four ESBL-genotype combinations were detected: blaPER + blaOXA-10 (n = 8), blaVEB-1 + blaOXA-10 (n = 6), blaPSE + blaOXA-10 (n = 1), and blaPER + blaVEB-1 + blaOXA-10 (n = 1). Three isolates (2.9%) possessed only the MBL encoding gene blaVIM. Three ESBL + MBL- genotype combinations: blaOXA-10 + blaAIM, blaOXA-10 + blaVIM, and blaPER + blaOXA-10 + blaAIM were detected in 2, 1 and 1 isolate(s), respectively. Five plasmid preparations harboring blaVEB-1 and blaOXA-10 were successfully transformed into chemically competent Escherichia coli DH5α with transformation efficiencies ranging between 6.8 × 10 3 and 3.7 × 10 4 CFU/μg DNA plasmid. Selected tested transformants were ceftazidime-resistant and harbored plasmids carrying blaOXA-10.

Conclusions: The study highlights the importance of the expeditious characterization of ESBLs and MBLs using genotypic methods among P. aeruginosa clinical isolates to hinder the development and dissemination of multidrug resistant strains.

Keywords: bla OXA-10; bla VIM; Curing; Genotype combinations; Transformation.

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Conflict of interest statement

Declarations. Conflict of interest: The authors declare that they have no competing interests. Ethics approval and consent to participate: The study was carried out in accordance with the guidelines and regulations of the Institutional Review Board (IRB) Committee, Faculty of Medicine, Alexandria University (IRB number: 00012098-FWA number: 00018699, serial number: 0306097). Consent to participate is not applicable for this study because this study does not contain any experiments with human participants and animals and the clinical isolates included in this study were obtained from existing clinical collections routinely assembled as part of laboratory practices of the medical microbiology lab at Alexandria Main University Hospital, Alexandria, Egypt. The need of consents was waived as neither the diagnosis nor the treatment was altered. Moreover, the data of the patients were not exposed. Consent for publication: Not applicable.

Figures

Fig. 1
Fig. 1
Correlation matrix showing Spearman’s correlation coefficients (rs) for each pair of antibiotics calculated according to the resistance patterns of 104 tested P. aeruginosa clinical isolates. The boldness of the blue color refers to the strength of the relationship between antibiotics, with stronger correlations having bolder colors. Numbers within boxes indicate correlation coefficient (rs) values. Spearman’s correlation coefficients (rs) written in bold indicate statistically significant levels of correlation at p-value ≤ 0.001. PIT piperacillin-tazobactam, CAZ ceftazidime, CPM cefepime, IPM imipenem, MRP meropenem, GEN gentamicin, CIP ciprofloxacin, LE levofloxacin, MO moxifloxacin, COL colistin
Fig. 2
Fig. 2
Distribution of resistance score (R score) mean values among P. aeruginosa ESBL/MBL profiles
Fig. 3
Fig. 3
Plasmid profile of selected P. aeruginosa clinical isolates. M: 1 kb DNA ladder, lane 1: P23, lane 2: P100, lane 3: P101, lane 4: P108, and lane 5: P121
Fig. 4
Fig. 4
PCR products of a blaVEB-1 gene and b blaOXA-10 gene using plasmid preparations as templates. a blaVEB-1 gene (643 bps); M: a 100 bps DNA ladder, lane 1: P23, lane 2: P78, lane 3: P100, lane 4: P101, lane 5: P108, lane 6: P121, lane 7: P123, b blaOXA-10 gene (276 bps); M: a 100 bps DNA ladder, lane 1: P23, lane 2: P78, lane 3: P100, lane 4: P101, lane 5: P108, lane 6: P121, and lane 7: P123
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References

    1. Peterson LR. Bad bugs, no drugs: no ESCAPE revisited. Clin Infect Dis. 2009;49:992–3. - PubMed
    1. Driscoll JA, Brody SL, Kollef MH. The epidemiology, pathogenesis and treatment of Pseudomonas aeruginosa infections. Drugs. 2007;67:351–68. - PubMed
    1. Gellatly SL, Hancock RE. Pseudomonas aeruginosa: new insights into pathogenesis and host defenses. Pathog Dis. 2013;67:159–73. - PubMed
    1. Chatterjee M, Anju C, Biswas L, Kumar VA, Mohan CG, Biswas R. Antibiotic resistance in Pseudomonas aeruginosa and alternative therapeutic options. Int J Med Microbiol. 2016;306:48–58. - PubMed
    1. Chaudhary M, Payasi A. Rising antimicrobial resistance of Pseudomonas aeruginosa isolated from clinical specimens in India. J Proteomics Bioinform. 2013;6:005–9.

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