Bacteriology of endotracheal tube biofilms and antibiotic resistance: a systematic review.

Bacteria commonly adhere to surfaces and produce polymeric material to encase the attached cells to form communities called biofilms. Within these biofilms, bacteria can appear to be many times more resistant to antibiotics or disinfectants. This systematic review explores the prevalence and microbial profile associated with biofilm production of bacteria isolated from endotracheal tubes and its associations with antimicrobial resistance. A comprehensive search was performed on databases PubMed, Embase, and Google Scholar for relevant articles published between 1st January 2000 and 31st December 2022. The relevant articles were exported to Mendeley Desktop 1.19.8 and screened by title and abstract, followed by full text screening based on the eligibility criteria of the study. Quality assessment of the studies was performed using the Newcastle-Ottawa Scale (NOS) customized for cross-sectional studies. Furthermore, the prevalence of antimicrobial resistance in biofilm-producers isolated from endotracheal tube specimens was investigated. Twenty studies encompassing 981 endotracheal tubes met the eligibility criteria. Pseudomonas spp. and Acinetobacter spp. were predominant isolates among the biofilm producers. These biofilms provided strong resistance against commonly used antibiotics. The highest resistance rate observed in Pseudomonas spp. was against fluoroquinolones whereas the least resistance was seen against piperacillin-tazobactam. A similar trend of susceptibility was observed in Acinetobacter spp. with a very high resistance rate against fluoroquinolones, third-generation cephalosporins and carbapenems. In conclusion, endotracheal tubes were associated with colonization by biofilm forming bacteria with varying levels of antimicrobial resistance. Biofilms may promote the occurrence of recalcitrant infections in endotracheal tubes which need to be managed with appropriate protocols and antimicrobial stewardship. Research focus should shift towards meticulous exploration of biofilm-associated infections to improve detection and management.

Efficiency and mechanism of intracellular paclitaxel delivery by novel nanopolymer-based tumor-targetes delivery system, Nanoxel

INTRODUCTION: An increasing research interest has been directed toward nanoparticle-based drug delivery systems for their advantages. The appropriate amalgamation of pH sensitivity and tumor targeting is a promising strategy to fabricate drug delivery systems with high efficiency, high selectivity and low toxicity. MATERIALS AND METHODS: A novel pH sensitive Cremophor-free paclitaxel formulation, Nanoxel(TM), was developed in which the drug is delivered as nanomicelles using a polymeric carrier that specifically targets tumors. The efficiency and mechanism of intracellular paclitaxel delivery by Nanoxel(TM) was compared with two other commercially available paclitaxel formulations: Abraxane(TM) and Intaxel(TM), using different cell lines representing target cancers [breast, ovary and non-small cell lung carcinoma (NSCLC)] by transmission electron microscopy and quantitative intracellular paclitaxel measurements by high performance liquid chromatography. RESULTS: The data obtained from the present study revealed that the uptake of nanoparticle-based formulations Nanoxel(TM) and Abraxane(TM) is mediated by the process of endocytosis and the uptake of paclitaxel was remarkably superior to Intaxel(TM) in all cell lines tested. Moreover, the intracellular uptake of paclitaxel in Nanoxel(TM)- and Abraxane(TM)-treated groups was comparable. Hence, the nanoparticle-based formulations of paclitaxel (Nanoxel(TM) and Abraxane(TM)) are endowed with higher efficiency to deliver the drug to target cells as compared to the conventional Cremophor-based formulation. CONCLUSION: Nanoxel(TM) appears to be of great promise in tumor targeting and may provide an advantage for paclitaxel delivery into cancer cells (AU)