Prevalence of drug-resistantPseudomonas aeruginosain Iranian burned patients: A meta-analysis

Surface modified niosomal quercetin with cationic lipid: an appropriate drug delivery system against Pseudomonas aeruginosa Infections

The Increase in infections caused by resistant strains of Pseudomonas aeruginosa poses a formidable challenge to global healthcare systems. P. aeruginosa is capable of causing severe human infections across diverse anatomical sites, presenting considerable therapeutic obstacles due to its heightened drug resistance. Niosomal drug delivery systems offer enhanced pharmaceutical potential for loaded contents due to their desirable properties, mainly providing a controlled-release profile. This study aimed to formulate an optimized niosomal drug delivery system incorporating stearylamine (SA) to augment the anti-bacterial and anti-biofilm activities of quercetin (QCT) against both standard and clinical strains of P. aeruginosa. QCT-loaded niosome (QCT-niosome) and QCT-loaded SA- niosome (QCT-SA- niosome) were synthesized by the thin-film hydration technique, and their physicochemical characteristics were evaluated by field emission scanning electron microscopy (FE-SEM), zeta potential measurement, entrapment efficacy (EE%), and in vitro release profile. The anti-P. aeruginosa activity of synthesized niosomes was assessed using minimum inhibitory and bactericidal concentrations (MICs/MBCs) and compared with free QCT. Additionally, the minimum biofilm inhibitory and eradication concentrations (MBICs/MBECs) were carried out to analyze the ability of QCT-niosome and QCT-SA-niosome against P. aeruginosa biofilms. Furthermore, the cytotoxicity assay was conducted on the L929 mouse fibroblasts cell line to evaluate the biocompatibility of the formulated niosomes. FE-SEM analysis revealed that both synthesized niosomal formulations exhibited spherical morphology with different sizes (57.4 nm for QCT-niosome and 178.9 nm for QCT-SA-niosome). The EE% for cationic and standard niosomal formulations was reported at 75.9% and 59.6%, respectively. Both formulations showed an in vitro sustained-release profile, and QCT-SA-niosome exhibited greater stability during a 4-month storage time compared to QCT-niosome. Microbial experiments indicated that both prepared formulations had higher anti-bacterial and anti-biofilm activities than free QCT. Also, the QCT-SA-niosome exhibited greater reductions in MIC, MBC, MBIC, and MBEC values compared to the QCT-niosome at equivalent concentrations. This study supports the potential of QCT-niosome and QCT-SA-niosome as effective agents against P. aeruginosa infections, manifesting significant anti-bacterial and anti-biofilm efficacy alongside biocompatibility with L929 cell lines. Furthermore, our results suggest that optimized QCT-niosome with cationic lipids could efficiently target P. aeruginosa cells with negligible cytotoxic effect.

Prevalence and antimicrobial-resistant patterns of Pseudomonas aeruginosa among burn patients attending Yekatit 12 Hospital Medical College in Addis Ababa, Ethiopia

BACKGROUND

Burns are one of the most common forms of trauma globally. P. aeruginosa plays a prominent role as an etiological agent among burn patients. There is a paucity of information about the prevalence and antimicrobial resistance patterns of P. aeruginosa among burn patients in Ethiopia. Hence, this study was designed to assess the prevalence and antimicrobial-resistant patterns of P. aeruginosa among burn patients attending Yekatit 12 Hospital Medical College in Addis Ababa, Ethiopia.

METHODS

Hospital-based cross-sectional study was conducted at Yekatit 12 Hospital Medical College among burn patients from November 2020 to April 2021. Identification of P. aeruginosa was performed using Culture, Biochemical tests, and, Gram staining. Antimicrobial resistance testing was done using the Kirby-Bauer disc diffusion method. Logistic regression was computed to determine associated factors.

RESULTS

From 210 burn wound cultures, 27 (12.86%) were found positive for P. aeruginosa. All the isolates showed greater than 70% susceptibility to the tested antibiotics except Gentamycin, Ceftazidime, and, Ciprofloxacin. In addition, 33.33% of P. aeruginosa isolates were multidrug-resistant. Admission type, Hospital stay time and Total body surface area (TBSA) had a statistically significant association (all with P-value <0.05) with the acquisition of P. aeruginosa infection.

CONCLUSION

Overall, the prevalence of P. aeruginosa isolates among burn patients is almost 13%. Most P. aeruginosa isolates were sensitive to Imipenem, while they were most resistant to Gentamycin. One-third of P. aeruginosa were multidrug-resistant. This suggests the need to monitor the treatment of infection with the pathogen to limit the possibility of the emergence of multidrug-resistant isolates in burn centers.

Molecular characterizations of antibiotic resistance, biofilm formation, and virulence determinants of Pseudomonas aeruginosa isolated from burn wound infection

BACKGROUND

Burn injuries result in disruption of the skin barrier against opportunistic infections. Pseudomonas aeruginosa is one of the main infectious agents colonizing burn wounds and making severe infections. Biofilm production and other virulence factors along with antibiotic resistance limit appropriate treatment options and time.

MATERIALS AND METHODS

Wound samples were collected from hospitalized burn patients. P. aeruginosa isolates and related virulence factors identified by the standard biochemical and molecular methods. Antibiotic resistance patterns were determined by the disc diffusion method and β-lactamase genes were detected by polymerase chain reaction (PCR) assay. To determine the genetic relatedness amongst the isolates, enterobacterial repetitive intergenic consensus (ERIC)-PCR was also performed.

RESULTS

Forty P. aeruginosa isolates were identified. All of these isolates were biofilm producers. Carbapenem resistance was detected in 40% of the isolates, and bla_TEM (37/5%), bla_VIM (30%), and bla_CTX-M (20%) were the most common β-lactamase genes. The highest resistance was detected to cefotaxime, ceftazidime, meropenem, imipenem and piperacillin, and 16 (40%) isolates were resistant to these antibiotics. The minimum inhibitory concentrations (MIC) of colistin was lower than 2 μg/mL and no resistance was observed. Isolates were categorized to 17 MDR, 13 mono-drug resistance, and 10 susceptible isolates. High genetic diversity was also observed among the isolates (28 ERIC types) and most carbapenem-resistant isolates were classified into four main types.

CONCLUSION

Antibiotic resistance, particularly carbapenem resistance was considerable among the P. aeruginosa isolates colonizing burn wounds. Combining carbapenem resistance with biofilm production and virulence factors would result in severe and difficult-to-treat infections.