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Original Research

Antibiogram and Genetic Characterization of Carbapenem-Resistant Gram-Negative Pathogens Incriminated in Healthcare-Associated Infections

ORCID Icon, , ORCID Icon, , , & ORCID Icon show all
Pages 3991-4002 | Published online: 04 Nov 2020

Figures & data

Table 1 Oligonucleotide Primers and Their Recycling Conditions Used for Detection of Class-A Carbapenemases Genes

Figure 1 (A) Modified Hodge Test; Positive result appeared as a cloverleaf-like indentation of the zone of inhibition of the E. coli ATCC 25922 (indicator organism) along with the streak of inoculum. (B) Combined Disk Test; An inhibition zones with ≥ 17 mm in the inhibition zone diameter of EDTA-containing imipenem disc compared to imipenem disc alone was a positive MBL producer. The negative result appeared as no difference in the zones diameter around the two discs.

Figure 1 (A) Modified Hodge Test; Positive result appeared as a cloverleaf-like indentation of the zone of inhibition of the E. coli ATCC 25922 (indicator organism) along with the streak of inoculum. (B) Combined Disk Test; An inhibition zones with ≥ 17 mm in the inhibition zone diameter of EDTA-containing imipenem disc compared to imipenem disc alone was a positive MBL producer. The negative result appeared as no difference in the zones diameter around the two discs.

Table 2 The Prevalence of Different Bacterial Pathogens Isolated from Various Types of Samples

Table 3 The Antimicrobial Resistance Profiles of the Retrieved Gram-Negative Rods

Table 4 The MIC Value of Carbapenem-Resistant Species Against Different Concentrations of Imipenem (µg ml−1)

Table 5 The Phenotypic and Genotypic Detection of Carbapenem-Resistant Strains

Figure 2 Gel electrophoresis analysis; (A) blaKPC gene (638bp); M 100 bp DNA ladder; C: Negative control; lane 1: Positive control; Lanes: 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13: positive isolates for blaKPC gene with specific amplicon size 638 bp; Lane 8: negative isolate. (B) blaGES gene (323 bp); M 100 bp DNA ladder; lane 1: Positive control; Lanes: 2–6 positive isolates for blaGES gene with specific amplicon size 323 bp.

Figure 2 Gel electrophoresis analysis; (A) blaKPC gene (638bp); M 100 bp DNA ladder; C: Negative control; lane 1: Positive control; Lanes: 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13: positive isolates for blaKPC gene with specific amplicon size 638 bp; Lane 8: negative isolate. (B) blaGES gene (323 bp); M 100 bp DNA ladder; lane 1: Positive control; Lanes: 2–6 positive isolates for blaGES gene with specific amplicon size 323 bp.

Figure 3 Dendrogram of the carbapenem-resistant bacterial pathogen isolated from clinical samples, constructed based on the 16S rRNA gene sequences. Bootstrap support value above branches, newly generated sequences of the isolated carbapenem-resistant Gram-negative bacterial pathogens in bold.

Figure 3 Dendrogram of the carbapenem-resistant bacterial pathogen isolated from clinical samples, constructed based on the 16S rRNA gene sequences. Bootstrap support value above branches, newly generated sequences of the isolated carbapenem-resistant Gram-negative bacterial pathogens in bold.