Evaluating the antibacterial effect of meropenem-loaded chitosan/sodium tripolyphosphate (TPP) nanoparticles on Acinetobacter baumannii isolated from hospitalized patients

• Published in: BMC infectious diseases 2024-06, Vol.24 (1), p.631-27, Article 631
• Main Authors: Amini, Marziyeh Sadat, Baseri Salehi, Majid, Bahador, Nima
• Format: Article
• Language: English
• Subjects: Acinetobacter baumannii; Acinetobacter baumannii - drug effects; Acinetobacter Infections - drug therapy; Acinetobacter Infections - microbiology; Amikacin; Ampicillin; Anti-Bacterial Agents - pharmacology; Antibacterial activity; Antibacterial agents; Antibiotic resistance; Antibiotics; Antiinfectives and antibacterials; Antimicrobial therapy; Antitoxins; Bacteria; Biocompatibility; Biological activity; Biological products; Care and treatment; Ceftazidime; Chitosan; Chitosan - analogs & derivatives; Chitosan - chemistry; Chitosan - pharmacology; Clinical isolates; Colistin; Cross infection; Cytotoxicity; Dosage and administration; Drug resistance; Drug resistance in microorganisms; Drug therapy; Encapsulation; Ethylenediaminetetraacetic acid; Genes; Health aspects; Health risks; Hospital patients; Hospitalization; Humans; Imipenem; In vivo methods and tests; Infections; Investigations; Iran; Meropenem; Meropenem - pharmacology; Microbial Sensitivity Tests; Minimum inhibitory concentration; Multidrug resistance; Nanoparticles; Nanoparticles - chemistry; Nosocomial infections; Patient outcomes; Pharmaceutical industry; Plasmids; Pneumonia; Political activity; Political aspects; Polyphosphates - chemistry; Polyphosphates - pharmacology; Prevention; Sodium triphosphate; Sodium tripolyphosphate; Sulbactam; Ticarcillin; Tobramycin; Toxins; Toxins and antitoxins; Zeta potential
• ISSN: 1471-2334; 1471-2334
• DOI: 10.1186/s12879-024-09522-7

Acinetobacter baumannii is a health threat due to its antibiotic resistance. Herein, antibiotic susceptibility and its association with the Toxin-antitoxin (TA) system genes in A. baumannii clinical isolates from Iran were investigated. Next, we prepared meropenem-loaded chitosan nanoparticles (MP-CS) and investigated their antibacterial effects against meropenem-susceptible bacterial isolates. Out of 240 clinical specimens, 60 A. baumannii isolates were assessed. Antibiotic resistance of the isolates against conventional antibiotics was determined alongside investigating the presence of three TA system genes (mazEF, relBE, and higBA). Chitosan nanoparticles were characterized in terms of size, zeta potential, encapsulation efficiency, and meropenem release activity. Their antibacterial effects were assessed using the well diffusion method, minimum inhibitory concentration (MIC), and colony-forming unit (CFU) counting. Their cytotoxic effects and biocompatibility index were determined via the MTT, LDH, and ROS formation assays. Ampicillin, ceftazidime, and colistin were the least effective, and amikacin and tobramycin were the most effective antibiotics. Out of the 60 isolates, 10 (16.7%), 5 (8.3%), and 45 (75%) were multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR), respectively. TA system genes had no significant effect on antibiotic resistance. MP-CS nanoparticles demonstrated an average size of 191.5 and zeta potential of 27.3 mV alongside a maximum encapsulation efficiency of 88.32% and release rate of 69.57%. MP-CS nanoparticles mediated similar antibacterial effects, as compared with free meropenem, against the A. baumannii isolates with significantly lower levels of meropenem. MP-CS nanoparticles remarkably prevented A549 and NCI-H292 cell infection by the A. baumannii isolates alongside demonstrating a favorable biocompatibility index. Antibiotic-loaded nanoparticles should be further designed and investigated to increase their antibacterial effect against A. baumannii and assess their safety and applicability in vivo settings.