Phage Therapy as an Alternative Treatment Modality for Resistant Staphylococcus aureus Infections

Isolation and characterization of bacteriophages against E.coli urinary tract infection and evaluating their anti-biofilm activity and antibiotic synergy

Urinary tract infections (UTIs) by Uropathogenic Escherichia coli (UPEC) are a significant health concern, especially due to the increasing prevalence of antibiotic resistance. This study focuses on isolating and characterizing bacteriophages specific to UPEC strains isolated from UTI samples. The isolated phages were assessed for their ability to target and lyse UPEC in vitro, focusing on their efficacy in disrupting biofilms, a key virulence factor contributing to UTI recurrence and antibiotic resistance. The morphological structure observed by TEM belongs to Myoviridae, the phage exhibited icosahedral symmetry with a long non-constricting tail, the approximate measurement of the phage head was 39 nm in diameter, and the phage tail was 105.317 nm in length. One-step growth experiments showed that the latent period was approximately 20 min, followed by a rise period of 40 min, and a growth plateau was reached within 20 min and the burst size observed was 26 phages/infected bacterial cells. These phages were capable of killing cells within the biofilms, leading to a reduction in living cell counts after a single treatment. This study highlights the potential of phages to play a significant role in disrupting, inactivating, and destroying Uropathogenic Escherichia coli (UPEC) biofilms. Such findings could be instrumental in developing treatment strategies that complement antibiotics and disinfectants. The phage-antibiotic synergistic activity was compared to have the possibility to facilitate the advancement of focused and enduring alternatives to traditional antibiotic therapies for UTIs.

Antibiotic resistance and tolerance: What can drug delivery do against this global threat?

Antimicrobial resistance and tolerance (AMR&T) are urgent global health concerns, with alarmingly increasing numbers of antimicrobial drugs failing and a corresponding rise in related deaths. Several reasons for this situation can be cited, such as the misuse of traditional antibiotics, the massive use of sanitizing measures, and the overuse of antibiotics in agriculture, fisheries, and cattle. AMR&T management requires a multifaceted approach involving various strategies at different levels, such as increasing the patient's awareness of the situation and measures to reduce new resistances, reduction of current misuse or abuse, and improvement of selectivity of treatments. Also, the identification of new antibiotics, including small molecules and more complex approaches, is a key factor. Among these, novel DNA- or RNA-based approaches, the use of phages, or CRISPR technologies are some potent strategies under development. In this perspective article, emerging and experienced leaders in drug delivery discuss the most important biological barriers for drugs to reach infectious bacteria (bacterial bioavailability). They explore how overcoming these barriers is crucial for producing the desired effects and discuss the ways in which drug delivery systems can facilitate this process.

Isolation and characterisation of a novel Silviavirus bacteriophage promising antimicrobial agent against methicillin-resistant Staphylococcus aureus infections

The increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) emphasises the urgent need for novel antimicrobial agents as alternatives to antibiotics. Bacteriophage therapy is one of the most promising antimicrobial strategies. Here, we isolated and comprehensively characterized a novel Staphylococcus phage, vB_SauM_VL10 (VL10), from urban sewage. The VL10 genome displays 141,746 bp of linear double-stranded DNA, containing 193 open reading frames and lacking tRNA, virulence, or antibiotic resistance genes. Phylogenetic analysis categorizes VL10 as a novel species within the Silviavirus genus, Twortvirinae subfamily. VL10 exhibits lytic behaviour characterized by efficient adsorption, a short latent period, and substantial burst size, with environmental stability. It demonstrates lytic activity against 79.06% of tested S. aureus strains, highlighting its species specificity. Additionally, VL10 effectively targets MRSA biofilms, reducing biomass and viable cells. In MRSA-infected G. mellonella larvae, VL10 enhances survival rates, supporting its potential for phage therapy applications. Moreover, the emergence of VL10-resistant S. aureus strains associated with fitness trade-offs, including reduced growth, biofilm formation, and virulence. Altogether, these findings emphasize VL10 as a promising candidate for developing therapeutic agents against MRSA infections, providing insights into phage biology and resistance dynamics.

Bacteriophages in nature: recent advances in research tools and diverse environmental and biotechnological applications

Bacteriophages infect and replicate within bacteria and play a key role in the environment, particularly in microbial ecosystems and bacterial population dynamics. The increasing recognition of their significance stems from their wide array of environmental and biotechnological uses, which encompass the mounting issue of antimicrobial resistance (AMR). Beyond their therapeutic potential in combating antibiotic-resistant infections, bacteriophages also find vast applications such as water quality monitoring, bioremediation, and nutrient cycling within environmental sciences. Researchers are actively involved in isolating and characterizing bacteriophages from different natural sources to explore their applications. Gaining insights into key aspects such as the life cycle of bacteriophages, their host range, immune interactions, and physical stability is vital to enhance their application potential. The establishment of diverse phage libraries has become indispensable to facilitate their wide-ranging uses. Consequently, numerous protocols, ranging from traditional to cutting-edge techniques, have been developed for the isolation, detection, purification, and characterization of bacteriophages from diverse environmental sources. This review offers an exploration of tools, delves into the methods of isolation, characterization, and the extensive environmental applications of bacteriophages, particularly in areas like water quality assessment, the food sector, therapeutic interventions, and the phage therapy in various infections and diseases.

Advances in bacteriophage-mediated strategies for combating polymicrobial biofilms

Bacteria and fungi tend to coexist within biofilms instead of in planktonic states. Usually, such communities include cross-kingdom microorganisms, which make them harder to remove from abiotic surfaces or infection sites. Additionally, the produced biofilm matrix protects embedded microorganisms from antibiotics, disinfectants, or the host immune system. Therefore, classic therapies based on antibiotics might be ineffective, especially when multidrug-resistant bacteria are causative factors. The complexities surrounding the eradication of biofilms from diverse surfaces and the human body have spurred the exploration of alternative therapeutic modalities. Among these options, bacteriophages and their enzymatic counterparts have emerged as promising candidates, either employed independently or in synergy with antibiotics and other agents. Phages are natural bacteria killers because of mechanisms of action that differ from antibiotics, phages might answer worldwide problems with bacterial infections. In this review, we report the attempts to use bacteriophages in combating polymicrobial biofilms in in vitro studies, using different models, including the therapeutical use of phages. In addition, we sum up the advantages, disadvantages, and perspectives of phage therapy.

Microbial Biofilms: Applications, Clinical Consequences, and Alternative Therapies

Biofilms are complex communities of microorganisms that grow on surfaces and are embedded in a matrix of extracellular polymeric substances. These are prevalent in various natural and man-made environments, ranging from industrial settings to medical devices, where they can have both positive and negative impacts. This review explores the diverse applications of microbial biofilms, their clinical consequences, and alternative therapies targeting these resilient structures. We have discussed beneficial applications of microbial biofilms, including their role in wastewater treatment, bioremediation, food industries, agriculture, and biotechnology. Additionally, we have highlighted the mechanisms of biofilm formation and clinical consequences of biofilms in the context of human health. We have also focused on the association of biofilms with antibiotic resistance, chronic infections, and medical device-related infections. To overcome these challenges, alternative therapeutic strategies are explored. The review examines the potential of various antimicrobial agents, such as antimicrobial peptides, quorum-sensing inhibitors, phytoextracts, and nanoparticles, in targeting biofilms. Furthermore, we highlight the future directions for research in this area and the potential of phytotherapy for the prevention and treatment of biofilm-related infections in clinical settings.

Recent trends in the use of bacteriophages as replacement of antimicrobials against food-animal pathogens

A major public health impact is associated with foodborne illnesses around the globe. Additionally, bacteria are becoming more resistant to antibiotics, which pose a global threat. Currently, many scientific efforts have been made to develop and implement new technologies to combat bacteria considering the increasing emergence of multidrug-resistant bacteria. In recent years, there has been considerable interest in using phages as biocontrol agents for foodborne pathogens in animals used for food production and in food products themselves. Foodborne outbreaks persist, globally, in many foods, some of which lack adequate methods to control any pathogenic contamination (like fresh produce). This interest may be attributed both to consumers' desire for more natural food and to the fact that foodborne outbreaks continue to occur in many foods. Poultry is the most common animal to be treated with phage therapy to control foodborne pathogens. A large number of foodborne illnesses worldwide are caused by Salmonella spp. and Campylobacter, which are found in poultry and egg products. Conventional bacteriophage-based therapy can prevent and control humans and animals from various infectious diseases. In this context, describing bacteriophage therapy based on bacterial cells may offer a breakthrough for treating bacterial infections. Large-scale production of pheasants may be economically challenging to meet the needs of the poultry market. It is also possible to produce bacteriophage therapy on a large scale at a reduced cost. Recently, they have provided an ideal platform for designing and producing immune-inducing phages. Emerging foodborne pathogens will likely be targeted by new phage products in the future. In this review article, we will mainly focus on the Bacteriophages (phages) that have been proposed as an alternative strategy to antibiotics for food animal pathogens and their use for public health and food safety.

Validity and Reliability of a Questionnaire on the Knowledge, Attitudes, Perceptions and Practices toward Food Poisoning among Malaysian Secondary School Students: A Pilot Study

Children in school settings are at risk of contracting food poisoning due to inadequate food safety practices and safe eating behaviors. This research aimed to develop a valid and reliable questionnaire on the knowledge, attitudes, perceptions, and practices (KAP2) toward food poisoning and its prevention among secondary school students. The questionnaire was developed by considering the Health Belief Model (HBM). A pilot study using a cross-sectional survey was conducted in Tangkak, Johor, among 30 selected students using a convenience sampling method. A pre-test was conducted on 15 secondary school students aged 13–17 years old prior to the pilot study, and they were excluded from the pilot study. The constructed knowledge was assessed using the difficulty and discrimination indices. Meanwhile, the reliability of the attitude, practice, and perception components in the questionnaire were assessed using Cronbach’s alpha. Regarding knowledge (34 items), the difficulty index showed that most items (n = 28) were easy, while one was difficult, and the remaining five were within an acceptable range. In addition, the discrimination index of the knowledge component (34 items) showed that twenty-two, three, and one had good, acceptable, and excellent ranges, respectively. Only eight items had a low discrimination power. All items of the attitude and practice components (10 items for each) showed a corrected item-total correlation value of >0.30. Only four out of twenty-one items of the perception component showed an unacceptable range of <0.30. However, following a discussion with the experts, all items were retained. With the incorporation of the HBM, the 75-item adapted food poisoning KAP2 questionnaire is valid and reliable. It can be utilized to measure and generate food poisoning KAP2 among secondary school students in Malaysia.