Clinical Specimens are the Pool of Multidrug- resistant Pseudomonas aeruginosa Harbouring oprL and toxA Virulence Genes: Findings from a Tertiary Hospital of Nepal

Abstract

The multidrug- or extensively drug-resistant (MDR/XDR) Pseudomonas aeruginosa carrying some virulence genes has become a global public health threat. However, in Nepal, there is no existing report showing the prevalence of oprL and toxA virulence genes among the clinical isolates of P. aeruginosa. Therefore, this study was conducted for the first time in the country to detect the virulence genes (oprL and toxA) and antibiotic susceptibility pattern of P. aeruginosa. A total of 7,898 clinical specimens were investigated following the standard microbiological procedures. The antibiotic susceptibility testing was examined by the modified disc diffusion method, and virulence genes oprL and toxA of P. aeruginosa were assessed using multiplex PCR. Among the analyzed specimens, 87 isolates were identified to be P. aeruginosa of which 38 (43.68%) isolates were reported as MDR. A higher ratio of P. aeruginosa was detected from urine samples 40 (45.98%), outpatients’ specimens 63 (72.4%), and in patients of the age group of 60–79 years 36 (41.37%). P. aeruginosa was more prevalent in males 56 (64.36%) than in female patients 31 (35.63%). Polymyxin (83.90%) was the most effective antibiotic. P. aeruginosa (100%) isolates harboured the oprL gene, while 95.4% of isolates were positive for the toxA gene. Identification of virulence genes such as oprL and toxA carrying isolates along with the multidrug resistance warrants the need for strategic interventions to prevent the emergence and spread of antimicrobial resistance (AMR). The findings could assist in increasing awareness about antibiotic resistance and suggest the judicious prescription of antibiotics to treat the patients in clinical settings of Nepal.

Roles of intrinsic and acquired resistance determinants in multidrug-resistant clinical Pseudomonas aeruginosa in Bangladesh

“…The high prevalence of significant virulence factors confirms the clinical nature of the isolates of P. aeruginosa 73,74 . A previous study in Nepal shows 95.4% of the clinical P. aeruginosa isolates harbor the toxA gene 75 , which supports our study's observance. As observed in this study, the high prevalence of lasB 76 and plcH 77 in clinical isolates of P. aeruginosa also agrees with previous reports.…”

Bacteriophage as a potential therapy to control antibiotic-resistant Pseudomonas aeruginosa infection through topical application onto a full-thickness wound in a rat model

“…Moreover, the Bla-TEM gene indicates β-lactam resistance [75]. OprL is an essential component of the outer membrane of the bacterial cell, which maintains its integrity and is considered a marker for identifying P. aeruginosa-associated infections [76]. In addition, PlcH encodes a hemolytic toxin that destroys cell membranes and phospholipids [77].…”

Molecular detection of multidrug-resistant Pseudomonas aeruginosa of different avian sources with pathogenicity testing and in vitro evaluation of antibacterial efficacy of silver nanoparticles against multidrug-resistant P. aeruginosa

“…Genomic DNA extraction was performed using a boiling method for 49 highly resistant P. aeruginosa isolates. Specific primers targeting the genes oprL (F: ATggAAATgCTgAAATTCggC and R: CTTCTTCAgCTCgACgCgACg) were used to amplify 504 bp products ( Chand et al, 2021 ). Following optimization, the following reaction mixtures (25 µL) were set up: 5 µL of DNA template, 0.5 µL of each set of primers, 12.5 µL of 2× PCR Master Mix, and 6.5 µL DNase/RNase-free water.…”