atpD gene sequencing, multidrug resistance traits, virulence-determinants, and antimicrobial resistance genes of emerging XDR and MDR-Proteus mirabilis

Abstract

Proteus mirabilis is a common opportunistic pathogen causing severe illness in humans and animals. To determine the prevalence, antibiogram, biofilm-formation, screening of virulence, and antimicrobial resistance genes in P. mirabilis isolates from ducks; 240 samples were obtained from apparently healthy and diseased ducks from private farms in Port-Said Province, Egypt. The collected samples were examined bacteriologically, and then the recovered isolates were tested for atpD gene sequencing, antimicrobial susceptibility, biofilm-formation, PCR detection of virulence, and antimicrobial resistance genes. The prevalence of P. mirabilis in the examined samples was 14.6% (35/240). The identification of the recovered isolates was confirmed by the atpD gene sequencing, where the tested isolates shared a common ancestor. Besides, 94.3% of P. mirabilis isolates were biofilm producers. The recovered isolates were resistant to penicillins, sulfonamides, β-Lactam-β-lactamase-inhibitor-combinations, tetracyclines, cephalosporins, macrolides, and quinolones. Using PCR, the retrieved strains harbored atpD, ureC, rsbA, and zapA virulence genes with a prevalence of 100%, 100%, 94.3%, and 91.4%, respectively. Moreover, 31.4% (11/35) of the recovered strains were XDR to 8 antimicrobial classes that harbored bla_TEM, bla_OXA-1, bla_CTX-M, tetA, and sul1 genes. Besides, 22.8% (8/35) of the tested strains were MDR to 3 antimicrobial classes and possessed bla_TEM, tetA, and sul1genes. Furthermore, 17.1% (6/35) of the tested strains were MDR to 7 antimicrobial classes and harbored bla_TEM, bla_OXA-1, bla_CTX-M, tetA, and sul1 genes. Alarmingly, three strains were carbapenem-resistant that exhibited PDR to all the tested 10 antimicrobial classes and shared bla_TEM, bla_OXA-1, bla_CTX-M, tetA, and sul1 genes. Of them, two strains harbored the bla_NDM-1 gene, and one strain carried the bla_KPC gene. In brief, to the best of our knowledge, this is the first study demonstrating the emergence of XDR and MDR-P.mirabilis in ducks. Norfloxacin exhibited promising antibacterial activity against the recovered XDR and MDR-P. mirabilis. The emergence of PDR, XDR, and MDR-strains constitutes a threat alarm that indicates the complicated treatment of the infections caused by these superbugs.

Figure 1

The radar illustrates the prevalence of P. mirabilis in different examined samples of apparently healthy and diseased ducks.

Figure 2

The phylogenetic analyses were based on the atpD gene sequencing. The phylogenetic tree illustrates the genetic relatedness of the retrieved P. mirabilis isolates and other relevant isolates deposited in the GenBank database. The tree topology was assessed by bootstrap analysis of 1000 replicates. The bacteria recovered in the present study are marked with solid red circles.

Figure 3

The heat-map illustrates the different degrees of susceptibility (sensitive, intermediate, and resistant) of the retrieved P. mirabilis to different tested antimicrobial agents.

Figure 4

The heat-map illustrates the correlation-coefficient (r) among various antimicrobial agents. Blue and red color points to the positive and negative correlations, respectively.

Figure 5

Illustrates the prevalence of biofilm-formation among the retrieved P. mirabilis strains. The percentage was calculated according to the total number of the retrieved isolates (n = 35).

Figure 6

The radar reveals the frequency of virulence genes and antimicrobial resistant genes between the retrieved P. mirabilis strains.

Figure 7

Illustrates the distribution of PDR, XDR, and MDR among the retrieved P. mirabilis strains.

Figure 8

The Heat-map demonstrates the correlation-coefficient (r) between different tested antimicrobial agents and the antimicrobial resistance genes.