Biocidal Polymers: Synthesis, Characterization and Antimicrobial Activity of Bis-Quaternary Onium Salts of Poly(aspartate-co-succinimide)

Assessment of toxicity and antimicrobial performance of polymeric inorganic coagulant and evaluation for eutrophication reduction

In this study, the efficacy of the promising iron-based polymeric inorganic coagulant (POFC) was assessed for the reduction of eutrophication effect (freshwater toxicity) and the microbial loads from wastewater. Toxicity assessment for POFC was conducted on mice and skin cell lines. The results confirm the lower toxicity level of POFC. The POFC showed excellent antibacterial efficacy against Gram-positive and Gram-negative bacteria. Moreover, it demonstrated a remarkable effectiveness against black fungus such as Aspergillus niger and Rhizopus oryzae. Additionally, POFC showed antiviral effectiveness against the highly pathogenic H5N1 influenza virus as well as Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). POFC-based treatment gives excellent removal percentages for phosphate, and phosphorus at doses below 60 ppm with a low produced sludge volume that leads to 84% decrease in the rate of eutrophication and freshwater toxicity. At a POFC concentration of 60 ppm, remarkable reduction rates for total coliforms, fecal coliforms, and E. coli were achieved. After POFC-based coagulation, the produced sludge retains a lower bacterial density due to the antibacterial activity of POFC. Furthermore, it revealed that the observed removal efficiencies for fungi and yeasts in the produced sludge reached 85% at a POFC dose of 60 ppm. Overall, our research indicates that POFC has potential for application in pre-treatment of wastewater and serves as an antimicrobial agent.

Quaternary Ammonium Salts: Insights into Synthesis and New Directions in Antibacterial Applications

The overuse of antibiotics has led to the emergence of a large number of antibiotic-resistant genes in bacteria, and increasing evidence indicates that a fungicide with an antibacterial mechanism different from that of antibiotics is needed. Quaternary ammonium salts (QASs) are a biparental substance with good antibacterial properties that kills bacteria through simple electrostatic adsorption and insertion into cell membranes/altering of cell membrane permeability. Therefore, the probability of bacteria developing drug resistance is greatly reduced. In this review, we focus on the synthesis and application of single-chain QASs, double-chain QASs, heterocyclic QASs, and gemini QASs (GQASs). Some possible structure-function relationships of QASs are also summarized. As such, we hope this review will provide insight for researchers to explore more applications of QASs in the field of antimicrobials with the aim of developing systems for clinical applications.

Emerging Status of Multidrug-Resistant Bacteria and Fungi in the Arabian Peninsula

Simple Summary

The incidence and developing status of multidrug-resistant bacteria and fungi, as well as their related mortality, is reviewed by a systematic published literature search from nine countries in the Arabian Peninsula. In order to analyse the emerging status and mortality, a total of 382 research articles were selected from a comprehensive screening of 1705 papers. More than 850 deaths reported since 2010 in the Arabian Peninsula due to the infection of multidrug-resistant bacteria and fungi. Multidrug-resistant bacteria Acinetobacter baumannii, Mycobacterium tuberculosis, Staphylococcus aureus, and fungi Candida auris are the most prevalent and causing high deaths. To control these infections and associated deaths in the Arabian Peninsula, continuous preventive measures, accurate methods for early diagnosis of infection, active surveillance, constant monitoring, developing vaccines, eradicating multidrug resistance modulators, and data sharing among countries are required.

Abstract

We aimed to identify the prevalence and emerging status of multidrug-resistant bacteria and fungi and their associated mortality in nine countries in the Arabian Peninsula. Original research articles and case studies regarding multidrug-resistant bacteria and fungi in the Arabian Peninsula, published during the last 10 years, were retrieved from PubMed and Scopus. A total of 382 studies were included as per the inclusion and exclusion criteria, as well as the PRISMA guidelines, from a thorough screening of 1705 articles, in order to analyse the emerging status and mortality. The emerging nature of >120 multidrug-resistant (MDR) bacteria and fungi in the Arabian Peninsula is a serious concern that requires continuous monitoring and immediate preventive measures. More than 50% (n = 453) of multidrug-resistant, microbe-associated mortality (n = 871) in the Arabian Peninsula was due to MDR Acinetobacter baumannii, Mycobacterium tuberculosis and Staphylococcus aureus infection. Overall, a 16.51% mortality was reported among MDR-infected patients in the Arabian Peninsula from the 382 articles of this registered systematic review. MDR A. baumannii (5600 isolates) prevailed in all the nine countries of the Arabian Peninsula and was one of the fastest emerging MDR bacteria with the highest mortality (n = 210). A total of 13,087 Mycobacterium tuberculosis isolates were reported in the region. Candida auris (580 strains) is the most prevalent among the MDR fungal pathogen in the Arabian Peninsula, having caused 54 mortalities. Active surveillance, constant monitoring, the development of a candidate vaccine, an early diagnosis of MDR infection, the elimination of multidrug resistance modulators and uninterrupted preventive measures with enhanced data sharing are mandatory to control MDR infection and associated diseases of the Arabian Peninsula. Accurate and rapid detection methods are needed to differentiate MDR strain from other strains of the species. This review summarises the logical relation, prevalence, emerging status and associated mortality of MDR microbes in the Arabian Peninsula.