Microbiological Assay Research Articles

In Vitro Biological Activities of Paederia grandidieri Leaf Extracts

In many developing countries, human health problems are solved using local plants. Knowledge of their chemical composition and biological activities can contribute to the creation of natural-based products usefully employed in human health. In this work, we analysed Paederia grandidieri leaves extracted with diverse eco-compatible procedures and subjected to chemical, microbiological, and cellular compatibility assays. Fresh leaves of P. grandidieri were harvested in southern Madagascar, where most of the population relies on P. grandidieri for daily dental care. Leaves were dried and powdered. Distilled water and ethanol at 25 °C and 60 °C from 6 to 24 h were used for extraction. Polyphenol composition, antioxidant activity, and antibacterial, prebiotic, and cytotoxic properties of the extracts were analysed. The aqueous extracts contained higher levels of flavan-3-ols and flavanones, while the hydro-alcoholic extracts were richer in flavonols and flavones. The aqueous extracts showed the highest total phenolic and total flavonoid contents, and antioxidant activity. The hydro-alcoholic extracts showed antibacterial effects against Listeria monocytogenes and Pseudomonas aeruginosa, two key foodborne and environmental pathogens, while the aqueous extracts showed prebiotic effects against Streptococcus salivarius. The cytotoxic effects of P. grandidieri leaf extracts were evaluated using the MTT assay on mouse fibroblasts (L929 cell line). The most cytotoxic extract was the aqueous extract at 25 °C. Given that P. grandidieri is routinely employed by the southern Madagascar population with healthy and strong teeth with fewer cases of tooth decay with respect to other regions, and in light of the significant chemical and microbiological properties, we maintain that P. grandidieri can be a suitable candidate for the production of pro-health products for the oral cavity. More in-depth studies will ensure a broader picture of the impact of extracts, especially for possible oral use.

Salt-Responsive Switchable Block Copolymer Brushes with Antibacterial and Antifouling Properties.

A strategy for multifunctional biosurfaces exploiting multiblock copolymers and the antipolyelectrolyte effect is reported. Combining a polyzwitterionic/antifouling and a polycationic/antibacterial block with a central anchoring block for attachment to titanium oxide surfaces affords surface coatings that exhibit antifouling properties against proteins and allow for surface regeneration by clearing adhering proteins by employing a salt washing step. The surfaces also kill bacteria by contact killing, which is aided by a nonfouling block. The synthesis of block copolymers of 4-vinyl pyridine (VP), dimethyl 4-vinylbenzyl phosphonate (DMVBP), and 4-vinylbenzyltrimethyl ammonium chloride (TMA) is achieved on the multigram scale via RAFT polymerization with good end group retention and narrow dispersities. By polymer analogous reactions, poly(4-vinyl pyridinium propane sulfonate-block-4-vinylbenzyl phosphonic acid-block-4-vinylbenzyl trimethylammonium chloride) (P(VSP64-b-PA14-b-TMA64)) is obtained. The antifouling properties against the model protein pepsin and the salt-induced surface regeneration are shown in surface plasmon resonance (SPR) experiments, while independently the antibacterial and antifouling properties of coated titanium substrates are successfully tested in preliminary microbiological assays against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). This strategy may contribute to the development of long-term effective antibacterial implant surface coatings to suppress biomedical device-associated infections.

Effect of Synthetic Fertilizer on Diazotrophic Bacteria in Secondary Forest and Oil Palm Soils in Central Kalimantan

Soil microorganisms, especially diazotrophic bacteria, are vital for ecosystem sustainability, significantly contributing to nitrogen cycling and biodiversity conservation. Understanding the impact of different land-use practices on soil microorganisms, especially synthetic fertilizer addition, is essential for sustainable agriculture. This study compares soil properties, bacterial densities, and responses to fertilization in secondary forest soils and adjacent oil palm plantation soils located in PT Kerry Sawit Indonesia, Central Kalimantan. A greenhouse experiment was conducted using both secondary forest and oil palm plantation soils to evaluate the impacts of different synthetic fertilizers on nitrogen-fixing bacteria and soybean agronomic performance. Total soil bacteria and diazotrophic bacteria, essential for nitrogen fixation, were analyzed through microbiological assays and qPCR focusing on the nifH gene. Our findings show that oil palm plantation soils had higher levels of nitrogen, phosphate, and nitrate, while secondary forest soils had a higher abundance of diazotrophic bacteria. Furthermore, excessive nitrogen fertilization was found to reduce microbial density, negatively impacting plant sustainability, highlighting the importance of customized fertilizer management. The study highlights the intricate connections between land-use practices and microbial populations, providing valuable insights for balancing agricultural productivity with ecological sustainability.

Antimicrobial activity of CuFe2O4 and CuFe2O4/ZnO: Squaring colorimetric and traditional microbiology assays with atomic force- and holotomography-microscopies

Intensive research efforts seek the discovery of efficient antimicrobial compounds to fight microbial resistance. Magnetic nanoparticles represent a promising option due to their multifunctional antimicrobial properties, as well as their versatility, stability, and the limited microbial resistance they generate. In this study, magnetic nanomaterials (MNMs) are synthesized using a microwave-activated solvothermal method. Characterization data indicate the crystalline nature (cubic spinel CuFe2O4 NMs), superparamagnetic behavior (MCF = 52 emu/g and MCF-ZnO = 29 emu/g) nanometric and regular size (spherical particles with a mean size of 7.4 ± 1.3 nm) of the MNMs. The antimicrobial activity of the as-prepared (naked) MNMs is moderate against bacteria, yeast, and fungal strains due to the aggregation of the MNMs in the exposure media. However, citrate-functionalized MNMs (CuFe2O4-Cit, CF-Cit) show enhanced antimicrobial activity, further increasing upon activation under a high-frequency magnetic field (magnetic hyperthermia). CF-Cit exerts stronger antibacterial activity towards S. aureus (MIC <25 μg/mL) than E. coli (MIC <50 μg/mL In addition, CuFe2O4-ZnO composites were synthesized and fully characterized. The MNMs under study exhibit efficient antifungal and anti-biofilm activity. Working towards the sustainable development of multifunctional (CuFe2O4 and CuFe2O4-ZnO) MNMs, their compatibility and bioactivity was evaluated using traditional assays and advanced microscopy techniques (Atomic Force Microscopy-AFM and Holotomographic Microscopy -HTM). Because of their chemical composition, the MNMs under study lixiviate transition metal ions to the exposure media, interfering with traditional colorimetric assays used to evaluate the bioactivity of the MNMs (antimicrobial, biocompatibility). Thus, AFM and HTM studies render complementary information during the interpretation of the bioactivity mechanisms exhibited by the MNMs.

Comparative Analysis of Quantitative Methods for Campylobacter spp. Quantification: ISO 10272-2:2017, Tempo® and Real-Time PCR in Refrigerated and Frozen Turkey Cuts.

New technologies for more effective microbiological assays are being adopted by the food industry to intervene more rapidly in its production chain. The aim of this study was to evaluate the alternative methods of TEMPO® CAM and real-time PCR (rtPCR) Biotecon® in comparison with the ISO 10272-2:2017 reference method for Campylobacter spp. quantification in turkey meat, aiming to validate a quick and easily replicable method in these meat matrices. A total of 416 samples were analyzed over a one-year period. The TEMPO® methodology showed inadequate performance with a significant difference (p < 0.05) compared with the reference methodology; therefore, its use was not recommended for turkey meat matrices. However, the performance of the rtPCR Biotecon® methodology showed adequate performance with no significant difference (p > 0.05), and its use was recommended in turkey meat matrices. The study was limited to exclusive research in turkey meat matrices, and expansion of the research into other matrices is recommended to verify whether the behavior of alternative methodologies is similar. The findings of this study illustrate the necessity for a thorough and comprehensive evaluation during the implementation of alternative methodologies that may potentially supplant conventional approaches.

Rapid identification of antibiotic residues in bovine kidney using coated blade spray-mass spectrometry

The use of certain antibiotics in food-producing animals is allowed in Europe following Regulation (EU) 2017/625. However, use could result in antibiotic residues in foodstuffs of animal origin. Maximum residue limits (MRLs) are in place to protect consumers. For monitoring purposes, animal matrices are tested to verify their compliance with these MRLs. Initially, matrices of (slaughtered) food animals are screened, often using a microbiological assay. Faster screening tests for antibiotics would be an advantage for control laboratories. Therefore, the present study describes, for the first time, the use of coated blade spray (CBS) followed by direct mass spectrometry (MS) analysis for the screening of tetracyclines, sulfonamides, quinolones, and macrolides residues from the renal area of intact bovine kidneys. An optimized workflow using two different desorption/ionization solutions per blade allowed screening of target compounds within 1 min per sample. The proof-of-principle of the CBS-MS method is validated according to (EU) 2021/808, presenting CCβ screening values of 0.1 × MRL for 43 analytes, 0.5 × MRL for 4 analytes, and 2.5 µg kg−1 for the prohibited substance dapsone, respectively. The developed method was successfully applied to seven official control samples of bovine kidneys. One of these samples was found to be positive using the CBS-MS method, which was confirmed as a true positive by LC-MSMS analysis. The developed method demonstrates that CBS devices can directly extract and analyze kidney samples for food safety testing.

Development of a dry powder formulation for pulmonary delivery of azithromycin-loaded nanoparticles.

The COVID-19 pandemic has raised concern regarding respiratory system diseases and oral inhalation stands out as an attractive non-invasive route of administration for pulmonary diseases such as chronic bronchitis, cystic fibrosis, COVID-19 and community-acquired pneumonia. In this context, we encapsulated azithromycin in polycaprolactone nanoparticles functionalized with phospholipids rich in dipalmitoylphosphatidylcholine and further produced a fine powder formulation by spray drying with monohydrated lactose. Nanoparticles obtained by the emulsion/solvent diffusion-evaporation technique exhibited a mean hydrodynamic diameter around 195-228nm with a narrow monomodal size distribution (PdI < 0.2). Nanoparticle dispersions were spray-dried at different inlet temperatures, atomizing air-flow, aspirator air flow, and feed rate, using lactose as a drying aid, resulting in a maximal process yield of 63% and an encapsulation efficiency of 83%. Excipients and the dry powder formulations were characterized in terms of morphology, chemical structure, thermal analyses and particle size by SEM, FTIR, DSC/TGA and laser light diffraction. The results indicated spherical particles with 90% at 4.06µm or below, an adequate size for pulmonary delivery. Aerosolization performance in a NGI confirmed good aerodynamic properties. Microbiological assays showed that the formulation preserves AZM antimicrobial effect against Staphylococcus aureus and Streptococcus pneumoniae strains, with halos above 18mm. In addition, no formulation-related cytotoxicity was observed against the human cell lines BEAS-2B (lung epithelial), HUVEC (endothelial) and HFF1 (fibroblasts). Overall, the approach described here allows the production of AZM-PCL nanoparticles incorporated into inhalable microparticles, enabling more efficient pulmonary therapy of lung infections.

Development of quercetin loaded biosynthesized chitosan grafted iron oxide nanoformulation and their antioxidant, antibacterial, and anti-cancer properties

In this study, we report the development and characterization of a novel nanoformulation composed of quercetin-loaded biosynthesized chitosan-grafted iron oxide nanoparticles (CH-Fe3O4 NCs). The synthesis of chitosan-grafted iron oxide nanoparticles was achieved through a green synthesis approach, utilizing chitosan derived from crustacean shells and biosynthesized iron oxide nanoparticles. Quercetin, a natural flavonoid with known antibacterial, anti-cancer, and antioxidant properties, was loaded onto the nanoparticles through physical adsorption. The optical property, crystal structure, morphology, chemical composition and surface charge were thoroughly characterized using various analytical techniques including UV–visible spectroscopy, X-ray diffractometer, scanning and transmission electron microscopy, fourier-transform infrared spectroscopy and zeta potential analyzer. The antibacterial activity of the nanoformulation was evaluated against a panel of bacterial strains using standard microbiological assays, revealing promising inhibitory effects against both Gram-positive and Gram-negative bacteria. The antibacterial activity of CH-Fe3O4 NCs was evaluated against E. coli and S. aureus bacterial species. CH-Fe3O4 NCs have a greater ability to inhibit the E.coli than S. aureus. Furthermore, the CH-Fe3O4 NCs demonstrated dose-dependent cytotoxicity and caused apoptotic cell death in the H522 cell line. Additionally, the antioxidant properties of the nanoformulation were evaluated through scavenging assays, highlighting its ability to effectively neutralize free radicals. Overall, our results suggest that the quercetin-loaded biosynthesized chitosan-grafted iron oxide nanoformulation exhibits potent antibacterial, anti-cancer, and antioxidant properties, making it a promising candidate for further development as a multifunctional therapeutic agent.

The Pharmacokinetics of Ceftazidime Following its Intravenous Administration in Dogs

Ceftazidime is a beta-lactam that is used in the treatment of bacterial infections in humans and companion animals, such as dogs and cats. It is prescribed to treat gram-negative infections, especially those caused by Pseudomonas aeruginosa. This study aimed to compare the pharmacokinetics of ceftazidime using a microbiological assay to evaluate the adequacy of the proposed dosage regimens for susceptible gram-negative bacteria. For this purpose, five healthy mongrel male dogs, with a mean age of four years and an average weight of 19.1 kg, were administered a single intravenous bolus dose of ceftazidime (20 mg/kg). Plasma concentrations were measured using a microbiological assay, and dosage regimens were established by integrating pharmacokinetics data with pharmacodynamics parameters. The results showed that ceftazidime was rapidly distributed to the peripheral tissues (0.189 L/kg), with a half-life of 1.15 hours and a clearance rate of 0.166 L/hr./kg. The results obtained from the pharmacokinetics-pharmacodynamic integration suggested 20 mg/kg q8 hours of ceftazidime for susceptible gram-negative bacteria with a Minimum Inhibitory Concentration of ≤ 8 µg/ml, and 20 mg /kg q12 hours of ceftazidime for susceptible gram-negative bacteria with a Minimum Inhibitory Concentration of ≤ 4 µg/ml. In conclusion, a mild correlation was observed between the dogs’ weight and the ceftazidime half-life, which led to an adjustment of the proposed dosage regimen to 20 mg/kg q8 hours.

The Antifungal Activity of Chitosan Nanoparticle-Incorporated Probiotics Against Oral Candidiasis.

Candida species, especially Candida albicans, cause oral candidiasis, also known as oral thrush. It affects the elderly, newborns, patients under antibiotics, chemotherapeutic agents, and patients with weaker immune systems. Although successful, traditional antifungal medications are available, they may have negative effects and do not prevent recurrence. Conventional antifungal medications have a restricted range of effectiveness; hence, the need for a novel antifungal agent arises. Chitosan, a natural polymer made from chitin found in crustaceans, kills fungal cells by damaging membranes. Excellent biocompatibility and biodegradability make it a promising medical material. Probiotics, live bacteria, compete with pathogenic microbes for adhesion sites and nutrients, produce antimicrobials such as lactic acid, hydrogen peroxide, and bacteriocins, and modulate the host's immunological response. Adding probiotics to chitosan nanoparticles (CSNPs) boosts their antifungal activity against Candida species and increases their stability and transport to the infection site. The antifungal activity was evaluated through in vitro experiments utilizing Candida strains that are significant to oral candidiasis. Different concentrations of CSNPs and formulations loaded with probiotics were examined to assess their effectiveness. The antifungal properties were assessed using microbiological assays, specifically agar diffusion and minimum inhibitory concentration (MIC). The study demonstrated a notable fungicidal impact of CSNPs combined with probiotics against oral candidiasis. Furthermore, the MICvalues were lower for the probiotic-loaded CSNPs than for chitosan alone or probiotics alone. The combination of CSNPs and probiotics shows potential in effectively combating oral candidiasis by inhibiting fungal growth. This novel method offers a promising strategy for creating therapeutic treatments for oral candidiasis by utilizing the combined benefits of chitosan and probiotics to combat fungal infections effectively.

Prototyping Ti2Cu intermetallic grain growth heterogeneously in Ti6Al4V matrix through laser additive manufacturing

The Ti2Cu intermetallics compound possessing an ability to release Cu2+ ions has promising antibacterial properties. This research integrates experimental and computational techniques to delve into the interfacial intermetallic (IMC) formation within the Ti6Al4V/Cu system. Heat transfer analysis is performed to numerically outline the thermal history within the microstructure during laser surface alloying (power = 1000 W and scan speed = 200 mm/s), while the phase field method is employed to describe the Ti2Cu IMC grain growth in the Ti6Al4V matrix. As the IMC and the matrix phases respectively have free energy minima of -68.52 and -61.35 kJ/mol at Taverage=1250.0 K, the growth of Ti2Cu IMC grains at the Ti6Al4V matrix located around the depth of 5 μm from the top surface is thermodynamically favorable. Laser processing can cause the nucleation of IMC precipitates of irregular sizes and curvature profiles, in which case the curvature driven effects between the adjacent grains can additionally affect their growth kinetics. Furthermore, microbiological assays underscore the superior antibacterial efficacy of the Ti6Al4V+Ti2Cu heterostructures as compared to the control (Ti6Al4V) counterpart.

Macrolide-loaded nanofibrous inserts with polycaprolactone and cellulose acetate base for sustained ocular delivery: Pharmacokinetic study in Rabbit’s eye

The present study aimed to prepare nanofibrous inserts for sustained ocular drug delivery of Azithromycin (AZM) toward conquering the obstacles of conventional topical drug delivery. Nanofibers were fabricated by electrospinning using polycaprolactone (PCL) and cellulose acetate (CA) which are biocompatible and biodegradable polymers. Prepared nanofibers were evaluated in terms of physicochemical, morphological properties, pharmacokinetic study and ocular irritation. SEM images revealed average diameters of about 160 nm and 190 nm for CA and PCL nanofibers, respectively. These ocular drug delivery systems were strong, flexible, and stable under humid and dry conditions. Quantification was performed using microbiological assay by M. luteus as a microorganism. While PCL-based nanofibrous inserts released AZM in a two-step manner initiated by a burst release via Peppas kinetical model, CA-based inserts showed a gradual release profile without any burst release which followed the first-order model. Results showed that these inserts were non-cytotoxic and non-irritating. The nanofibers showed antibacterial efficacy against Escherichia coli and Staphylococcus aureus. In addition, according to a pharmacokinetic study in Rabbit’s Eye, a higher Cmax and lower Tmax were achieved by PCL nanofibers compared to CA-based ones. The pharmacokinetic study of nanofibers in rabbit eyes showed that all formulations were able to maintain the effective concentration of AZM for about 6 days. In conclusion, the prepared nanofibers can be effectively utilized for prolonged ocular delivery of AZM in the treatment of conjunctival infections.

Pharmacokinetic Profile of Ceftriaxone and Meropenem in Dogs

The principal aim of the study was evaluating the pharmacokinetic of ceftriaxone and meropenem in dogs, eight healthy male dogs were used for this experiment. A microbiological assay was used to determine the pharmacokinetic indices of ceftriaxone and meropenem given intravenously. The values were then fitted to a two-compartment pharmacokinetic open model in order to assess the factors related to distribution and excretion. The obtained results showed that the half-life, volume of distribution, and total body clearance to the samples of plasma of ceftriaxone and meropenem were recorded (0.83 h., 0.35 L/kg and 0.28 L/hr/kg), (0.86 h., 0.48 L/kg and 0.33 L/hr/kg), and the ratio of plasma protein binding were 16.67 %; 9.58 %, respectively. In conclusion, through the pharmacokinetic characteristics of meropenem and ceftriaxone in dogs, they possess an efficacious profile against K. pneumonia as same as other sensitive bacteria which were qualified to be a potential candidate to be one of the most commonly used parenterally administered antibacterial medicines in the treatment of acute bacterial cases that need to be treated quickly in veterinary therapy. However, the differences in the pharmacokinetic profile proved that the effectiveness of meropenem was more than ceftriaxone.

The Dual Mode of Antibacterial Action of the Synthetic Small Molecule DCAP Involves Lipid II Binding.

The synthetic small molecule DCAP is a chemically well-characterized compound with antibiotic activity against Gram-positive and Gram-negative bacteria, including drug-resistant pathogens. Until now, its mechanism of action was proposed to rely exclusively on targeting the bacterial membrane, thereby causing membrane depolarization, and increasing membrane permeability (Eun et al. 2012, J. Am. Chem. Soc. 134 (28), 11322-11325; Hurley et al. 2015, ACS Med. Chem. Lett. 6, 466-471). Here, we show that the antibiotic activity of DCAP results from a dual mode of action that is more targeted and multifaceted than previously anticipated. Using microbiological and biochemical assays in combination with fluorescence microscopy, we provide evidence that DCAP interacts with undecaprenyl pyrophosphate-coupled cell envelope precursors, thereby blocking peptidoglycan biosynthesis and impairing cell division site organization. Our work discloses a concise model for the mode of action of DCAP which involves the binding to a specific target molecule to exert pleiotropic effects on cell wall biosynthetic and divisome machineries.

Antibiotic Residues and Resistance in Three Wastewater Treatment Plants in Romania

This study evaluates antibiotic residues and bacterial loads in influent and effluent samples from three wastewater treatment plants (WWTPs) in Romania, across four seasons from 2021 to 2022. Analytical methods included solid-phase extraction and high-performance liquid chromatography (HPLC) to quantify antibiotic concentrations, while microbiological assays estimated bacterial loads and assessed antibiotic resistance patterns. Statistical analyses explored the impact of environmental factors such as temperature and rainfall on antibiotic levels. The results showed significant seasonal variations, with higher antibiotic concentrations in warmer seasons. Antibiotic removal efficiency varied among WWTPs, with some antibiotics being effectively removed and others persisting in the effluent, posing high environmental risks and potential for antibiotic resistance development. Bacterial loads were higher in spring and summer, correlating with increased temperatures. Eight bacterial strains were isolated, with higher resistance during warmer seasons, particularly to amoxicillin and clarithromycin.

Crotamine derived from Crotalus durissus terrificus venom combined with drugs increases in vitro antibacterial and antifungal activities.

This study investigated crotamine (CTA), a peptide derived from the venom of the South American rattlesnake Crotalus durissus terrificus, known for its exceptional cell penetration potential. The objective was to explore the antibacterial and antifungal activity of CTA, its ability to inhibit efflux pumps and evaluate the effectiveness of its pharmacological combination with antibiotics and antifungals. In microbiological assays, CTA in combination with antibiotics was tested against strains of S. aureus and the inhibition of NorA, Tet(K) and MepA efflux pumps was also evaluated. CTA alone did not present clinically relevant direct antibacterial action, presenting MIC > 209.7µM against strains S. aureus 1199B, IS-58, K2068. The standard efflux pump inhibitor CCCP showed significant effects in all negative relationships to assay reproducibility. Against the S. aureus 1199B strain, CTA (20.5µM) associated with norfloxacin diluted 10 × (320.67µM) showed a potentiating effect, in relation to the control. Against the S. aureus IS-58 strain, the CTA associated with tetracycline did not show a significant combinatorial effect, either with 2304 or 230.4µM tetracycline. CTA at a concentration of 2.05µM associated with ciprofloxacin at a concentration of 309.4µM showed a significant potentiating effect. In association with EtBr, CTA at concentrations of 2.05 and 20.5µM potentiated the effect in all strains tested, reducing the prevention of NorA, Tet(K) and MepA efflux pumps. In the C. albicans strain, a potentiating effect of fluconazole (334.3µM) was observed when combined with CTA (2.05µM). Against the C. tropicalis strain, a significant effect was also observed in the association of fluconazole 334.3µM, where CTA 2.05µM considerably reduced fungal growth and decreased the potentiation of fluconazole. Against the C. krusei strain, no significant potentiating effect of fluconazole was obtained by CTA. Our results indicate that CTA in pharmacological combination potentiates the effects of antibiotics and antifungal. This represents a new and promising antimicrobial strategy for treating a wide variety of infections.

Comparison of microbiological and molecular diagnosis for identification of respiratory secondary infections in COVID-19 patients and their antimicrobial resistance patterns

We report the use of a new multiplex Real-Time PCR platform to simultaneously identify 24 pathogens and 3 antimicrobial-resistance genes directly from respiratory samples of COVID-19 patients. Results were compared to culture-based diagnosis.Secondary infections were detected in 60% of COVID-19 patients by molecular analysis and 73% by microbiological assays, with no significant differences in accuracy, indicating Gram-negative bacteria as the predominant species. Among fungal superinfections, Aspergillus spp. were detected by both methods in more than 7% of COVID-19 patients. Oxacillin-resistant S. aureus and carbapenem-resistant K. pneumoniae were highlighted by both methods.Secondary microbial infections in SARS-CoV-2 patients are associated with poor outcomes and an increased risk of death. Since PCR-based tests significantly reduce the turnaround time to 4 hours and 30 minutes (compared to 48 hours for microbial culture), we strongly support the routine use of molecular techniques, in conjunction with microbiological analysis, to identify co/secondary infections.

Phage based biosensors: Enhancing early detection of emerging pathogens in diagnostics

Global health is seriously threatened by an increase in antibiotic resistance among ESKAPE pathogens- E- E. faecium, S- S.aureus, K- K.pneumoniae, A-A.baumannii, P- P.aeruginosa, and E-Enterobacter. The resistance of many bacteria to traditional antibiotics is increasing, making the search for novel approaches critical. In order to minimize the effect of these diseases, early detection, diagnosis, and treatment are important. However, there are drawbacks to traditional detection techniques such molecular-based, biochemical, and microbiological assays. These include the inability to detect on-site, as well as their time-consuming, expensive, and labour-intensive nature. Viral agents that target bacteria exclusively, known as bacteriophages, have shown promise in combating over infections resistant to antibiotics. Bacteriophage-based biosensors are adaptable to many environmental conditions and offer special features such as host specificity and ability to identify active infections. They're very accurate, very specific, and have quick assay times, which makes them beneficial tools for detection. Also, phages are more easily produced than antibodies and can withstand high pH, temperature, and chemical solvents. The potential of bacteriophage-based biosensors in the fight against ESKAPE pathogens is highlighted by this review. Bacteriophage-based biosensors provide simplified detection processes in contrast to conventional approaches, which makes them invaluable in environmental and clinical situations. Numerous platforms, including electrochemical, magnetoelastic, quartz crystal microbalance, and surface plasmon resonance sensors, being investigated for their potential use to detect pathogenic bacteria in a range of sample types.

Biopolymeric sensor based on natural deep eutectic solvents for monitoring meat spoilage

Ensuring food safety by monitoring freshness is crucial, particularly for high-protein meat products susceptible to spoilage. Smart packaging with pH-sensitive indicators, using natural pigments such as anthocyanin, provides a cost-effective and non-invasive solution. In this work, a novel colorimetric pH sensor based on biopolymer and natural deep eutectic solvents (NADES) is proposed. The NADES composed by Betaine: Glycerol: Water (BGH) was used for the anthocyanin extraction from Brassica oleracea (Purple Cabbage, PC), using the ultrasonic “one-step” method and BGH extraction efficiency was compared with water. Then, the BGH extract was mixed with different concentrations of xanthan gum (XG) 5, 10, 15 and 20%. The biopolymeric materials were characterized in terms of structure, mechanical properties, stability and pH response. The combination containing 10 % of xanthan gum (PC-BGH-XG10) presented suitable features to be used as a sensor. Thus, PC-BGH-XG10 was applied for real-time monitoring of meat spoilage. Interestingly colour changes were visible to the naked eye and they were successfully correlated with microbiological assays. To the best of our knowledge, this is the first integration of NADES and xanthan gum in the development of a colorimetric pH sensor. The proposed approach represents a green strategy for in-situ control of packaged foods intended for final consumption.

Infectious Diseases and Clinical Xenotransplantation.

Xenotransplantation, transplantation into humans of vascularized organs or viable cells from nonhuman species, is a potential solution to shortages of transplantable human organs. Among challenges to application of clinical xenotransplantation are unknown risks of transmission of animal microbes to immunosuppressed recipients or the community. Experience in allotransplantation and in preclinical models suggests that viral infections are the greatest concern. Worldwide, the distribution of swine pathogens is heterogeneous and cannot be fully controlled by international agricultural regulations. It is possible to screen source animals for potential human pathogens before procuring organs in a manner not possible within the time available for surveillance testing in allotransplantation. Infection control measures require microbiological assays for surveillance of source animals and xenograft recipients and research into zoonotic potential of porcine organisms. Available data suggest that infectious risks of xenotransplantation are manageable and that clinical trials can advance with appropriate protocols for microbiological monitoring of source animals and recipients.