Chitosan Nanoparticles: As an Anti-Biofilm Agent against Acinetobacter Strains baumannii Representing the Multidrug Resistance Phenotype

Introduction: Acinetobacter baumannii (A. baumannii) is a non-fermentative gram-negative coccobacillus that shows high resistance to antimicrobial compounds. Biofilm formation is one of the essential features of many Acinetobacter species that leads to high antibiotic resistance. This study aimed to evaluate the ability of biofilm formation and determine the antibiofilm activity of chitosan nanoparticles in clinical isolates of A. baumannii. Material & Methods: This descriptive cross-sectional study was conducted in 2021 and investigated 100 isolates collected from different hospitals. Microscopic, biochemical, and molecular tests were performed to identify the bacteria. The antibiotic resistance pattern of the isolates was evaluated by the disk diffusion method against 10 antibiotics, and the ability to produce biofilm was evaluated by microtiter plate method. Subsequently, 16SrRNA and CsuA genes were identified by multiplex-PCR molecular methods. After the preparation of chitosan nanoparticles and determination of MIC concentration, antibiofilm activity was measured by plate microtiter, and Real-Time PCR was used to examine the expression of the CsuA gene involved in biofilm. Findings: In this study, out of 100 isolates examined, 29 isolates were confirmed as A. baumannii. Among 29 isolates, ceftazidime had the highest drug resistance (75.86%). The CsuA gene was detected in 51.72% of the isolates. Moreover, using a microtiter plate and Real-Time PCR, the level of antibiotic activity of chitosan nanoparticles was determined at a significant level of P<0.01. Discussion & Conclusion: Considering the anti-biofilm effects found in the present study, it seems that chitosan nanoparticles can be used as a pharmaceutical candidate in the pharmaceutical industry

Simultaneous and rapid detection of avian respiratory diseases of small poultry using multiplex reverse transcription-Polymerase Chain Reaction assay

ABSTRACT: Major viral infections, such as Newcastle disease virus, infectious bronchitis virus, avian influenza virus, and infectious bursal disease virus, inflict significant injury to small poultry and tremendous economic damage to the poultry sector. This research aims to develop a multiplex reverse transcriptase polymerase chain reaction (m-RT-PCR) approach to simultaneously determine these important viral pathogens. The conserved segment of various viral genetic sequences was used to design and synthesize specific primers. Moreover, as positive controls, recombinant vectors were synthesized in this investigation. The d-optimal approach was used to improve PCR conditions in this investigation. Positive controls and clinical samples were used to assess the m-PCR assay's specificity, sensitivity, repeatability, and reproducibility. According to the sensitivity test findings, the m-PCR technique could generate the 8 target genes from viral genomes using 1 × 102. In addition, 8 viral pathogens were detected from the infected samples. The findings also suggest that live animal oral swabs were not significantly different from tissue sampling of a dead animal (P < 0.05), and this kit had a high sensitivity for analyzing both types of samples. The suggested m-PCR test may detect and evaluate viral infection in birds with excellent specificity, sensitivity, and throughput