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Published on: May 4, 2018
Characterization of antibiotic resistance profiles in Pseudomonas aeruginosa isolates from burn patients
Asma Tchakal-Mesbahi1, Merzak Metref2, Vijay K Singh3
1Department of Cellular and Molecular Biology, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene, P.B. 32 El-Alia, Bab-Ezzouar, 16111, Algiers, Algeria.
Objective:
To investigate the prevalence of multidrug-resistant (MDR) Pseudomonas aeruginosa (PA) producing extended-spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) in burn patients in Algeria.
Methods:
Between April 2016 and October 2019, 47 non-redundant isolates of PA were collected from 47 burn patients admitted to the Department of Burns at the Military Hospital of Algiers in Algeria. Antibiotic susceptibility testing was performed by agar diffusion and the Phoenix automated method. Resistance genes were identified by PCR, and molecular typing of isolates was carried out by enterobacterial repetitive intergenic consensus (ERIC) sequences-polymerase chain reaction (PCR).
Results:
Among the 47 non-redundant MDR PA strains isolated, 59.57% were phenotypically ESBLs-positive, and 100% were phenotypically MBL-positive. The ESBL-positive isolates were subsequently screened for six groups of bla genes encoding ESBL-type enzymes, namely blaCTX-M2, blaPER, blaTEM, blaSHV, blaVEB, and blaGES. Out of the 28 ESBL-producing strains, 23 (82.14%) were blaCTX-M2 positive; 18 (38.29%) were blaPER positive, and 16 (34.04%) were blaTEM positive, while 5 (17.9%) were co-harboring blaCTX-M2, blaTEM, and blaPER genes. The blaSHV, blaVEB, and blaGES genes were not detected in any of the ESBL positive isolates. Since all isolates were MBL-positive, all 47 strains were screened for the blaNDM-1, blaIMP, blaVIM genes that produce MBLs; however, none of these genes were detected. Additional screening for the oprD gene demonstrated that 45 (95.74%) of the isolates were positive for this gene. Finally, ERIC PCR revealed 11 distinct PA clones among the blaCTX-M2 positive strains.
Conclusion:
This is the first study to report the presence of CTX-M2-producing PA in the North Africa region and the first to detect blaCTX-M2-positive and blaPER-positive PA clinical isolates in Algeria, therefore demonstrating the spread of such MDR strains to this part of the world. Identification of bacterial genotypic alterations that confer antibiotic resistance is critical in determining the most effective antimicrobial strategies to be employed. Therefore, our findings could potentially facilitate clinical decision making regarding the antibiotics of choice for the treatment of burn patients that suffer from PA infections in Algeria.
Insights
Multidrug-resistant Pseudomonas aeruginosa (MDR PA) producing extended-spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) are prevalent in Algerian burn patients. This study identified blaCTX-M2 and blaPER genes in PA, highlighting the need for targeted antimicrobial strategies.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Pseudomonas aeruginosa (PA) is a significant opportunistic pathogen, particularly in burn wound infections.
- The emergence of multidrug-resistant (MDR) strains, including those producing extended-spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs), poses a critical threat to patient care.
- Algeria, as part of the North Africa region, requires specific data on the prevalence and genetic basis of MDR PA infections.
Purpose of the Study:
- To investigate the prevalence of MDR Pseudomonas aeruginosa (PA) in burn patients in Algeria.
- To identify the presence and genetic markers of ESBL and MBL production in these isolates.
- To understand the molecular epidemiology of MDR PA in this specific patient population.
Main Methods:
- Collection of 47 non-redundant PA isolates from burn patients between April 2016 and October 2019.
- Antibiotic susceptibility testing using agar diffusion and automated methods.
- Identification of resistance genes (bla genes, oprD) via PCR and molecular typing using ERIC sequences-PCR.
Main Results:
- 59.57% of MDR PA isolates were phenotypically ESBL-positive, and 100% were MBL-positive.
- The blaCTX-M2 gene was detected in 82.14% of ESBL-producing strains, along with blaPER (38.29%) and blaTEM (34.04%).
- No blaSHV, blaVEB, blaGES, blaNDM-1, blaIMP, or blaVIM genes were detected; 95.74% of isolates carried the oprD gene. 11 distinct PA clones were identified among blaCTX-M2 positive strains.
Conclusions:
- This study is the first to report CTX-M2-producing PA in North Africa and blaCTX-M2/blaPER-positive clinical isolates in Algeria.
- The findings demonstrate the spread of MDR PA strains carrying specific resistance genes to this region.
- Understanding these genotypic alterations is crucial for guiding effective antimicrobial treatment strategies for burn patients in Algeria.
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