Phage therapeutics: from promises to practices and prospectives.

The rise in multi-drug resistant bacteria and the inability to develop novel antibacterial agents limits our arsenal against infectious diseases. Antibiotic resistance is a global issue requiring an immediate solution, including the development of new antibiotic molecules and other alternative modes of therapy. This article highlights the mechanism of bacteriophage treatment that makes it a real solution for multidrug-resistant infectious diseases. Several case reports identified phage therapy as a potential solution to the emerging challenge of multi-drug resistance. Bacteriophages, unlike antibiotics, have special features, such as host specificity and do not impact other commensals. A new outlook has also arisen with recent advancements in the understanding of phage immunobiology, where phages are repurposed against both bacterial and viral infections. Thus, the potential possibility of phages in COVID-19 patients with secondary bacterial infections has been briefly elucidated. However, significant obstacles that need to be addressed are to design better clinical studies that may contribute to the widespread use of bacteriophage therapy against multi-drug resistant pathogens. In conclusion, antibacterial agents can be used with bacteriophages, i.e. bacteriophage-antibiotic combination therapy, or they can be administered alone in cases when antibiotics are ineffective.Key points• AMR, a consequence of antibiotic generated menace globally, has led to the resurgence of phage therapy as an effective and sustainable solution without any side effects and high specificity against refractory MDR bacterial infections.• Bacteriophages have fewer adverse reactions and can thus be used as monotherapy as well as in conjunction with antibiotics.• In the context of the COVID-19 pandemic, phage therapy may be a viable option.

Polybrominated diphenyl ethers with potent and broad spectrum antimicrobial activity from the marine sponge Dysidea.

Three polybrominated diphenyl ethers, 2-(2',4'-dibromophenoxy)-3,5-dibromophenol (1) and 2-(2',4'-dibromophenoxy)-3,4,5-tribromophenol (2) were isolated from the marine sponge Dysidea granulosa; and 2-(2',4'-dibromophenoxy)-4,6-dibromophenol (3) from Dysidea spp. They exhibited potent and broad spectrum in vitro antibacterial activity, especially against methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), Escherichia coli O157:H7, and Salmonella. Minimal inhibitory concentration (MIC) was evaluated against 12 clinical and standard strains of Gram positive and negative bacteria. The observed MIC range was 0.1-4.0mg/L against all the Gram positive bacteria and 0.1-16.0mg/L against Gram negative bacteria. 2-(2',4″-Dibromophenoxy)-3,5-dibromophenol showed stronger broad spectrum antibacterial activity than other two compounds. 2-(2',4″-Dibromophenoxy)-3,5-dibromophenol and 2-(2',4'-dibromophenoxy)-4,6-dibromophenol are thermo-stable. The results suggest that 2-(2',4'-dibromophenoxy)-3,5-dibromophenol could be used as a potential lead molecule for anti-MRSA, anti-E. coli O157:H7, and anti-Salmonella for drug development.

Application of an oregano oil nanoemulsion to the control of foodborne bacteria on fresh lettuce.

Although antimicrobial activities of plant essential oils are well documented, challenges remain as to their application in fresh produce due to the hydrophobic nature of essential oils. Oregano oil nanoemulsions were formulated with a food-grade emulsifier and evaluated for their efficacy in inactivating the growth of foodborne bacteria on fresh lettuce. Lettuce was artificially inoculated with Listeria monocytogenes, Salmonella Typhimurium and Escherichia coli O157:H7, followed by a one-minute dipping in oregano oil nanoemulsions (0.05% or 0.1%). Samples were stored at 4 °C and enumerated for bacteria at fixed intervals (0 h, 3 h, 24 h, and 72 h). Compared to control, 0.05% nanoemulsion showed an up to 3.44, 2.31, and 3.05 log CFU/g reductions in L. monocytogenes, S. Typhimurium, and E. coli O157:H7, respectively. Up to 3.57, 3.26, and 3.35 log CFU/g reductions were observed on the same bacteria by the 0.1% treatment. Scanning Electron Microscopy (SEM) demonstrated disrupted bacterial membranes due to the oregano oil treatment. The data suggest that applying oregano oil nanoemulsions to fresh produce may be an effective antimicrobial control strategy.

Characterization of methicillin-resistant coagulase-negative staphylococci (MRCoNS) in retail meat.

This study was to understand the extent of methicillin-resistant coagulase-negative staphylococci (MRCoNS) serving as a mecA reservoir in retail meat. MRCoNS were isolated from retail meat (beef, chicken, and turkey) in Detroit and characterized by sodA gene sequencing for species identification, staphylococcal cassette chromosome mec (SCCmec) typing, and pulsed-field gel electrophoresis (PFGE). Unique MRCoNS isolates recovered from 25 meat samples were comprised of Staphylococcus sciuri (n = 13), Staphylococcus fleuretti (n = 4), Staphylococcus lentus (n = 3), Staphylococcus epidermidis (n = 2), Staphylococcus vitulinus (n = 1), Staphylococcus saprophyticus (n = 1) and Staphylococcus pasteuri (n = 1). Heterogeneous and composite SCCmec types, including I, III, IV, V, I + V and III + V were identified in 16 isolates. Same SCCmec types were recovered in different staphylococcal species and meat sources. Indistinguishable PFGE patterns were also observed in S. sciuri isolated from beef, chicken, and turkey, and with different SCCmec types. In conclusion, multiple CoNS species can serve as reservoirs for mecA. In addition to the clonal transmission of MRCoNS in meat, horizontal occurrence of SCCmec is observed in staphylococcal species.

Antimicrobial Activity of Polycaprolactone Nanofiber Coated with Lavender and Neem Oil Nanoemulsions against Airborne Bacteria.

The development of efficient, eco-friendly antimicrobial agents for air purification and disinfection addresses public health issues connected to preventing airborne pathogens. Herein, the antimicrobial activity of a nanoemulsion (control, 5%, 10%, and 15%) containing neem and lavender oils with polycaprolactone (PCL) was investigated against airborne bacteria, including Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Various parameters such as the physicochemical properties of the nanoemulsion, pH, droplet size, the polydispersity index (PDI), the minimum inhibitory concentration (MIC), the minimum bacterial concentration (MBC), and the color measurement of the emulsion have been evaluated and optimized. Our results showed that the antimicrobial activity of PCL combined with neem and lavender oil was found to be the highest MIC and MBC against all tested bacteria. The droplet sizes for lavender oil are 21.86-115.15 nm, the droplet sizes for neem oil are 23.92-119.15 nm, and their combination is 25.97-50.22 nm. The range of pH and viscosity of nanoemulsions of various concentrations was found to be 5.8 to 6.6 pH and 0.372 to 2.101 cP. This study highlights the potential of nanotechnology in harnessing the antimicrobial properties of natural essential oils, paving the way for innovative and sustainable solutions in the fight against bacterial contamination.

Comparative Seed Proteome Profile Reveals No Alternation of Major Allergens in High-Yielding Mung Bean Cultivars.

Mung bean contains up to 32.6% protein and is one of the great sources of plant-based protein. Because many allergens also function as defense-related proteins, it is important to determine their abundance levels in the high-yielding, disease-resistant cultivars. In this study, for the first time, we compared the seed proteome of high-yielding mung bean cultivars developed by a conventional breeding approach. Using a label-free quantitative proteomic platform, we successfully identified and quantified a total of 1373 proteins. Comparative analysis between the high-yielding disease-resistant cultivar (MC5) and the other three cultivars showed that a total of 69 common proteins were significantly altered in their abundances across all cultivars. Bioinformatic analysis of these altered proteins demonstrated that PDF1 (a defensin-like protein) exhibited high sequence similarity and epitope matching with the established peanut allergens, indicating a potential mung bean allergen that showed a cultivar-specific response. Conversely, known mung bean allergen proteins such as PR-2/PR-10 (Vig r 1), Vig r 2, Vig r 4, LTP1, ß-conglycinin, and glycinin G4 showed no alternation in the MC5 compared to other cultivars. Taken together, our findings suggest that the known allergen profiles may not be impacted by the conventional plant breeding method to develop improved mung bean cultivars.

Bacteriophage therapy for Escherichia coli-induced urinary tract infection in rats.

Background: The present study evaluates the efficacy of bacteriophage therapy for urinary tract infection (UTI) in rats. Methods: UTI was established by inoculating Escherichia coli (100 µl) at a concentration of 1.5 × 108 CFU/ml per urethra via a cannula in different groups of rats. For treatment, phage cocktails (200 µl) were administered at varying concentrations of 1 × 108 PFU/ml, 1 × 107 PFU/ml and 1 × 106 PFU/ml. Results: The two doses of phage cocktail at the first two concentrations resulted in the cure of UTI. However, the lowest concentration of the phage cocktail warranted more doses to eradicate the causative bacteria. Conclusion: The quantity, frequency and safety of doses could be optimized in a rodent model using the urethral route.

Antimicrobial resistance is primarily caused by antibiotic overuse and misuse, which results in a decline in the ability of antibiotics to treat infections. Urinary tract infections (UTIs) are common but difficult to treat, as they are frequently caused by multidrug-resistant bacteria. Escherichia coli is a common cause of UTIs. Bacteriophages are a potentially viable alternative for the treatment of bacterial infections, and despite the numerous benefits of using phages as antibacterial therapeutics, there are surprisingly few original research articles based on clinical trials, specifically against UTIs. In this study, the efficiency of a customized bacteriophage cocktail for the treatment of UTIs, with varied doses administered directly into the urinary bladder of rats, was evaluated. At higher concentrations, UTIs were completely eradicated after two doses of the bacteriophage cocktail. However, at lower concentrations, additional doses were required to eradicate the infection. Phage therapy appears to have therapeutic potential, and this study indicates the potential frequency of dosages at appropriate concentrations. Phage therapy was both effective and safe.

Bacterial profile and antibiotic susceptibility pattern of uropathogens causing urinary tract infection in the eastern part of Northern India.

Urinary tract infection (UTI) is a common infectious disease that affects men and women. It is a significant health concern due to multidrug-resistant (MDR) organisms. Therefore, it is necessary to have a current understanding of the antibiotic susceptibility (AS) pattern of uropathogens to manage UTI effectively. Since the bacterial pathogen causing UTI and its AS vary with time and place, the prevailing AS pattern of the causative agents are essential for empirical antibiotic therapy. This study aims to determine the prevalence and AS of uropathogens isolated from UTI patients in the eastern part of Northern India. The study was carried out between November 2018 and December 2019. Clean catch midstream urine samples were collected and processed using standard guidelines for microbiological procedures. Positive microbiological cultures were found in 333 of the 427 patients, where 287 were gram-negative bacteria (GNB), and 46 were gram-positive bacteria (GPB). Females had a higher prevalence of UTI (60.7%) than males (39.3%) (p = 0.00024). The most susceptible age group in females was 18-50 years as compared to males, whereas at the age of 51-80 years and >80 years males were more susceptible than females (p = 0.053). The most prevalent pathogen identified were Escherichia coli (55.0%), followed by Proteus sp. (6.9%), Klebsiella pneumoniae (6.6%), Pseudomonas aeruginosa (6.3%), of which 96.0% were MDR bacteria. The susceptibility pattern of our study also revealed that amikacin, gentamycin and imipenem were the most effective drugs against GNB. In contrast, nitrofurantoin, vancomycin, and chloramphenicol were the most effective drugs against GPB. According tothe findings, MDR pathogens are very much prevalent. Since UTI is one of the most frequent bacterial diseases, proper management necessitates extensive investigation and implementation of antibiotic policy based on AS patterns for a particular region.

A modified micro chamber agar spot slide culture technique for microscopic examination of filamentous fungi.

The slide culture technique aids in the study of undisturbed microscopic morphological details of filamentous fungi. The existing methods for setting up of slide culture are quite cumbersome, time-consuming and require elaborate preparation. We describe a modified and easy to perform micro chamber agar spot slide culture technique.

Comparison of phenotypic methods in predicting methicillin resistance in coagulase-negative Staphylococcus (CoNS) from animals.

Phenotypic detection of methicillin resistance in coagulase-negative Staphylococcus (CoNS) of animal origin has been challenging due to the heterogeneous expression of mecA. To compare different phenotypic methods in predicting the mecA presence in CoNS, a total of 87 CoNS isolates from agricultural animals were analyzed in this study by agar dilution, disk diffusion, and broth microdilution. mecA was present in 81 CoNS isolates. Broth microdilution demonstrated the highest sensitivity of 100% in predicting the mecA presence, followed by 72.8% by agar dilution and 70.4% by disk diffusion. The results indicate that broth microdilution may be more suitable for predicting the presence of mecA in CoNS from animals than the other two methods, although staphylococcal species may also be a factor affecting the sensitivities of the methods as the top three staphylococcal species in this study were Staphylococcus lentus, Staphylococcus sciuri, and Staphylococcus xylosus (a total of 75 of 87).