Resistant Pathogens Research Articles

Effect of colistin-tigecycline combination on colistin-resistant and carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii.

Colistin resistance in carbapenem-resistant Gram-negative pathogens is a serious challenge in clinical settings. Our study showed that low concentration of colistin can be effective when combined with tigecycline. It presents the possibility of an available treatment option for antibiotic-resistant pathogens.

Understanding Bacterial Resistance to Heavy Metals and Nanoparticles: Mechanisms, Implications, and Challenges.

Antimicrobial resistance is a global health problem as it contributes to high mortality rates in several infectious diseases. To address this issue, engineered nanoparticles/nano-formulations of antibiotics have emerged as a promising strategy. Nanoparticles are typically defined as materials with dimensions up to 100nm and are made of different materials such as inorganic particles, lipids, polymers, etc. They are widely dispersed in the environment through various consumer products, and their clinical applications are diverse, ranging from contrast agents in imaging to carriers for gene and drug delivery. Nanoparticles can also act as antimicrobial agents either on their own or in combination with traditional antibiotics to produce synergistic effects, earning them the label of "next-generation therapeutics." They have also shown great effectiveness against multidrug-resistant pathogens responsible for nosocomial infections. However, overexposure or prolonged exposure to sublethal doses of nanoparticles can promote the development of resistance in human pathogens. The resistance can arise from various factors such as genetic mutation, horizontal gene transfer, production of reactive oxygen species, changes in the outer membrane of bacteria, efflux-induced resistance, cross-resistance from intrinsic antibiotic resistance determinants, plasmid-mediated resistance, and many more. Continuous exposure to nanoparticles can also transform an antibiotic-susceptible bacterial pathogen into multidrug resistance. Considering all these, the current review focuses on the mode of action of different heavy metals and nanoparticles and possible mechanisms through which bacteria attain resistance towards these heavy metals and nanoparticles.

Hemp Microbiome Composition and Function Under Developing Pest Management Solutions

Conventional pesticides used in cropping systems prevent damage caused by pathogens and pests but may also have unintended consequences for non-target organisms associated with plants. For example, fungicide application may affect microbes such as fungal endophytes that potentially confer protective benefits to the host, such as pathogen or pest resistance. Here we investigated how fungicide application and pathogen inoculation altered the communities of pathogenic and non-target endophytic leaf microbes in hemp (Cannabis sativa L.). We found that fungicide application and inoculation with fungal pathogens affected hemp-associated microbial communities. Fungicide application altered fungal endophyte community composition, increased heterogeneity of fungal communities, reduced pathogen abundance, and decreased diversity of the endophytic fungal community. Inoculation with pathogenic fungi decreased the abundance of bacterial endophytes relative to control and fungicide-treated plants. We then investigated the potential of a common fungal endophyte isolated from this study, Ophiocordyceps sp., as a biological control agent for Helicoverpa zea, a common insect pest in hemp. Contrary to our expectations, larvae preferred food inoculated with Ophiocordyceps sp., though it did not alter growth or mortality of larvae. Together, our results indicate that hemp-associated endophyte communities are sensitive to abiotic and biotic manipulations, and that fungicide application impacts non-target microorganisms that could confer important functions for crop health. We encourage future studies to analyze the impact of biological control agents on host ecology in an integrated pest management plan and to examine ways to better utilize existing microbial associations to create biological controls.

Antimicrobial Pattern of Foodborne Bacterial Hazards Isolated from Vegetables in Dhaka City

The prevalence of undesirable microbial contaminants in fresh vegetables, often consumed raw as salad vegetables, is a concern for the global public health community. In this study, samples from different local markets in Dhaka were collected to evaluate the microbiological quality and safety of four raw salad vegetables, namely, lettuce, tomato, cucumber, and coriander leaves. Microbiological analyses revealed a higher total aerobic bacterial count (3.10 to 8.71 log CFU/g) and coliform count (non-detectable to 7.61 log CFU/g) regardless of RSV type. In all of the examined shop types, foodborne pathogens like Escherichia coli and Salmonella spp. were found in more than 60% of the analyzed vegetable samples, and the isolated E. coli and Salmonella spp. were found to be completely resistant to 3 different antibiotics (Amoxicillin, Erythromycin, and Rifampicin) and intermediately resistant to 2 other antibiotics (Bacitracin and Novobiocin). Therefore, the study findings revealed that the presence of multidrug-resistant E. coli and Salmonella spp. in fresh vegetable samples is a cause for worry when consumed raw. Controlled environment production approaches, such as indoor farming of vegetables and washing with plenty of fresh water before consumption, can help to reduce pathogen and antimicrobial resistance bacteria. J. of Sci. and Tech. Res. 6(1): 45-51, 2024

Chitosan-casein as novel drug delivery system for transferring Phyllanthus emblica to inhibit Pseudomonas aeruginosa

This study investigated the ability of Phyllanthus emblica encapsulated within chitosan-coated casein (CS-casein-Amla) nanoparticles to inhibit the growth of multi-drug-resistant Pseudomonas aeruginosa (P. aeruginosa) bacteria and prevent the formation of biofilms. The MDR strains underwent screening, and the morphological characteristics of the resulting nanoparticles were assessed using SEM, DLS, and FTIR. In addition, the efficacy of encapsulation, stability, and drug release were evaluated. The PpgL, BdlA, and GacA biofilm gene transcription quantities were quantified by quantitative real-time PCR. Simultaneously, the nanoparticles were assessed for their antibacterial and cytotoxic effects using the well diffusion and MTT procedures. CS-casein-Amla nanoparticles with a size of 500.73 ± 13 nm, encapsulation efficiency of 76.33 ± 0.81%, and stability for 60 days at 4 °C (Humidity 30%) were created. The biological analysis revealed that CS-casein-Amla nanoparticles exhibited strong antibacterial properties. This was shown by their capacity to markedly reduce the transcription of PpgL, BdlA, and GacA biofilm genes at a statistically significant value of p ≤ 0.01. The nanoparticles demonstrated decreased antibiotic resistance compared to unbound Amla and CS-casein. Compared to Amla, CS-casein-Amla nanoparticles showed very little toxicity against HDF cells at dosages ranging from 1.56 to 100 µg/mL (p ≤ 0.01). The results highlight the potential of CS-casein-Amla nanoparticles as a significant advancement in combating highly resistant P. aeruginosa. The powerful antibacterial properties of CS-casein-Amla nanoparticles against P. aeruginosa MDR strains, which are highly resistant pathogens of great concern, may catalyze the development of novel antibacterial research approaches.

The potential utility of phage therapy in the treatment of periprosthetic infection caused by multidrug-resistant pathogens: a review

Background. One of the main and most costly problems in large joint arthroplasty associated with socially significant losses is periprosthetic infection. Of particular importance is periprosthetic joint infection (PJI) caused by antibiotic-resistant pathogens and followed by the worst treatment results. Currently, when antibiotic-resistant pathogens are spreading rapidly, particularly in health facilities, researchers are constantly looking for alternative treatments for severe cases of PJI. Phage therapy can be one of these methods. The aim of the review was to analyse the application of personalized bacteriophages in the management of periprosthetic infection caused by multidrug-resistant pathogens during arthroplasty of large joints of the lower extremities. Methods. A 20-year literature search (2003-2023) was performed in the eLIBRARY, PubMed, Google Scholar, and Scopus electronic databases. Results. During the search, 1.482 publications meeting the objectives of this review were found. Taking into account the inclusion/non-inclusion criteria adopted by the authors, the review included 12 studies describing 45 cases of the use of bacteriophages in the management of hip and knee PJI caused by multidrug-resistant pathogens. The infection was eradicated without recurrence in 42 cases (89.4%), recurrence was recorded only in 5 cases (10.6%). Conclusions. The analysis of the literature confirms that a combination therapy of personalized phages and antibiotics as adjuvant therapy is safe and effective. Bacteriophage treatment is a promising direction in the fight against resistant pathogens of periprosthetic infection. Its combination with antibiotics seems to be the most promising, as it can significantly increase the effectiveness of therapy for infections caused by multidrug-resistant pathogens due to the synergy of these drug classes.

Atividade antimicrobiana dos extratos hidroalcoólicode Eugenia uniflora L. (Myrtaceae) e Schinus molle L.(Anacardiaceae)

The indiscriminate use of antimicrobials available in the market today has been contributing to the increase in the quantity of resistant pathogens. In recent years, significant attention has been given to the use of antimicrobial compounds of natural origin. This growing demand for new bioactive compounds stems from the knowledge that some medicinal plants often exhibit antimicrobial activity. Thus, the aim of this study was to evaluate the antimicrobial effect of hydroalcoholic extracts from the leaves of E. uniflora (Surinam cherry) and S. molle (Brazilian pepper tree) against clinically relevant microorganisms. The leaves were collected from adult plants, identified at the Herbarium of the University of Vale do Sapucaí, where a voucher specimen was deposited. The extract was prepared using the maceration technique in 70% ethanol. Antimicrobial activity was assessed using the disc diffusion method according to the Kirby-Bauer methodology. The microorganisms used were reference strains of: Escherichia coli ATCC8739, Staphylococcus aureus ATCC6538, Pseudomonas aeruginosa ATCC9027, Salmonella typhimurium ATCC14028, Candida albicans ATCC90028, Candida glabrata MYA2950, Candida Krusei ATCC6258, Candida parapsilosis ATCC22019, and Candida utilis ATCC9950. The extracts showed antifungal and antibacterial activity against the studied microorganisms. These findings contribute to the potential future use of these plants as antimicrobial agents.

Antifungal Properties of Bioactive Compounds Isolated from Fucus vesiculosus Supercritical Carbon Dioxide Extract

The exploration of natural antifungal substances from algal origins is significant due to the increasing resistance of pathogens to conventional antifungal agents and the growing consumer demand for natural products. This manuscript represents the inaugural investigation into the antifungal attributes of bioactive compounds extracted from Fucus vesiculosus via supercritical carbon dioxide (scCO2) extraction utilizing contemporary countercurrent chromatography (CCC). In aligning with the prospective utilization of this extract within the agricultural sector, this study also serves as the preliminary report demonstrating the capability of Fucus vesiculosus scCO2 extract to enhance the activity of plant resistance enzymes. The fractions obtained through CCC were subjected to evaluation for their efficacy in inhibiting the macrospores of Fusarium culmorum. The CCC methodology facilitated the successful separation of fatty acids (reaching up to 82.0 wt.% in a given fraction) and fucosterol (attaining up to 79.4 wt.% in another fraction). All CCC fractions at the concentration of 1.0% were found to inhibit 100% of Fusarium culmorum growth. Moreover, Fucus vesiculosus scCO2 extract was able to activate plant resistance enzymes (Catalase, Ascorbic Peroxidase, Guaiacol Peroxidase, Phenylalanine Ammonia-Lyase, and Phenylalanine Ammonia-Lyase Activity).

Probiotic Potential of Yeasts Isolated from Fermented Beverages: Assessment of Antagonistic Strategies Against Salmonella enterica Serovar Enteritidis

Global concern about pathogenic resistance to antibiotics is prompting interest in probiotics as a strategy to prevent or inhibit infections. Fermented beverages are promising sources of probiotic yeasts. This study aimed to evaluate the antagonistic effects of Kluyveromyces marxianus, Wickerhamomyces anomalus, and Pichia manshurica strains from kefir and wine against Salmonella enterica serovar Enteritidis in intestinal epithelial cells. The ability of these yeasts to adhere to Caco-2/TC-7 cells was evaluated, as well as their influence on the ability of Salmonella to associate and invade these cells. The behavior of the pathogen was analyzed by (a) incubation of enterocytes with yeast before adding Salmonella, (b) co-incubation of Salmonella with yeast before contact with the enterocytes, and (c) incubation of Salmonella with yeast metabolites before contact with enterocytes. All yeast strains demonstrated adherence to Caco-2/TC-7 cells (33–100%) and effectively inhibited Salmonella invasion. Among the treatments, co-culture showed the greatest effect, reducing Salmonella association and invasion by more than 50%. Additionally, these yeasts modulated the epithelial immune response, significantly decreasing CCL20-driven luminescence by 60–81% (p < 0.0001). These results highlight the potential of yeasts from fermented beverages as probiotics to counteract Salmonella infections, offering a promising alternative in the fight against antibiotic resistance.

New Ground in Antifungal Discovery and Therapy for Invasive Fungal Infections: Innovations, Challenges, and Future Directions

This review explores current advancements and challenges in antifungal therapies amid rising fungal infections, particularly in immunocompromised patients. We detail the limitations of existing antifungal classes—azoles, echinocandins, polyenes, and flucytosine—in managing systemic infections and the urgent need for alternative solutions. With the increasing incidence of resistance pathogens, such as Candida auris and Aspergillus fumigatus, we assess emerging antifungal agents, including Ibrexafungerp, T-2307, and N′-Phenylhydrazides, which target diverse fungal cell mechanisms. Innovations, such as nanoparticles, drug repurposing, and natural products, are also evaluated for their potential to improve efficacy and reduce resistance. We emphasize the importance of novel approaches to address the growing threat posed by fungal infections, particularly for patients with limited treatment options. Finally, we briefly examine the potential use of artificial intelligence (AI) in the development of new antifungal treatments, diagnoses, and resistance prediction, which provides powerful tools in the fight against fungal pathogens. Overall, we highlight the pressing need for continued research to advance antifungal treatments and improve outcomes for high-risk populations.

Evaluating Antibiotic Resistance in the Bacterial Pathogens Isolated from Avian Species

The avian population plays a vital role as both a reservoir and sentinel for numerous pathogens. Antimicrobials are widely used for the treatment and control of infections in avian species. However, inappropriate selection, irrational use of these antibiotics may contribute to the development of drug resistance in population. This research evaluates the Antibiogram of Chlamydia psittaci, Klebsiella pneumonia, Escherichia coli, Staphylococcus epidermidis and Pasteurella multocida isolated from caged and free-living birds. Antimicrobial susceptibility was tested using the disk diffusion method on Mueller Hinton Agar, according to instructions by the Clinical and Laboratory Standards Institute. Chlamydia psittaci exhibited sensitivity to sulfamethoxazole (22mm), azithromycin (21mm), doxycycline (20mm) and gentamicin (15mm). In contrast, penicillin G, oxacillin, amoxicillin and chloramphenicol were ineffective. Escherichia coli shown azithromycin (20mm), doxycycline (16mm) and gentamicin (15mm) were most effective. Klebsiella pneumoniae demonstrated high sensitivity to sulfamethoxazole (20mm) and doxycycline (18mm), and showing complete resistance to oxacillin and rifampin. Pasteurella multocida exhibited the highest susceptibility to doxycycline (21mm), sulfamethoxazole (20mm), amoxicillin (20mm), chloramphenicol (19mm), norfloxacin (18mm) and gentamicin (16mm). Staphylococcus epidermidis demonstrated high sensitivity to norfloxacin (23mm), doxycycline (23mm), oxacillin (22mm), chloramphenicol (22mm), sulfamethoxazole (17mm) and gentamicin (15mm). The current study reveals sulfamethoxazole, doxycycline, and azithromycin were highly effective antibiotics against the bacterial pathogens infecting avian species. Penicillin G, amoxicillin, oxacillin, and ampicillin were resistant against the identified bacterial species.

Development of Nanomaterials-Based Agents for Selective Antibacterial Activity.

Bacterial infections continue to threaten public health due to limitations in rapid and accurate diagnostic techniques. While broad-spectrum antibiotics offer empirical treatment, their overuse has fuelled the emergence of antimicrobial resistance (AMR) pathogens, posing a critical global public health challenge. In this critical scenario, nanomaterial-based antibacterial agents emerge as a promising solution to combat bacteria and inhibit their proliferation. However, selective elimination of pathogenic bacteria is paramount. This review highlights recent advancements in developing nanomaterials for selective antibacterial activity. We categorize these agents based on their mode of action, exploring how they selectively interact with bacteria and their potential antibacterial mechanisms. This review offers crucial insights for researchers exploring the potential of nanotechnology to address the growing threat of AMR.

Multispecies emergence of dual blaKPC/NDM carbapenemase-producing Enterobacterales recovered from invasive infections in Chile.

Carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) represent a significant global threat. The emergence of dual CP-CRE is particularly alarming, as they can potentially compromise the efficacy of newer antibiotics, further decreasing therapeutic alternatives. Herein, we report the emergence of multiple species of CP-CRE recovered from invasive infections in Chile that simultaneously harbor blaKPC and blaNDM and provide an in-depth genomic characterization of these worrisome pathogens. We collected carbapenem-resistant Enterobacterales (CRE) isolates from invasive infections over a 4-year period, across 11 healthcare centers in Chile. Bacterial species and the presence of carbapenemase genes were confirmed using MALDI-TOF and PCR assays, respectively. Antimicrobial susceptibility testing was conducted through disk diffusion and broth microdilution methods. Dual CP-CRE isolates were subjected to short- and long-read whole genome sequencing to perform a detailed genomic characterization of the isolates and of the mobile genetic elements harboring the enzymes. From a total of 1,335 CRE isolates, we observed an increase in the prevalence of CP-CRE, from 11% in 2019 to 38% in 2022. A total of 11 dual CP-CRE isolates were recovered, all of them harboring blaKPC and blaNDM. Species corresponded to Escherichia coli (n = 6), Klebsiella pneumoniae (n = 2), Klebsiella oxytoca (n = 2), and Citrobacter freundii (n = 1). Dual CP-CRE isolates exhibited resistance to all tested β-lactams except for cefiderocol. The blaKPC and blaNDM encoding genes were located on independent plasmids. Platforms harboring blaKPC were diverse and included IncN, IncF, and IncFIB plasmids. In contrast, blaNDM-7 was only found on fairly conserved IncX3 plasmids. We report that a rapid increase of CP-CRE in Chile, alongside with the emergence of multiple bacterial species of CP-CRE co-harboring blaKPC-2/3 and blaNDM-7, underscores a critical public health challenge. Our data suggest that the dissemination of blaNDM-7 was predominantly facilitated by IncX3 plasmids, whereas the spread of blaKPC involved multiple plasmid backbones. Active surveillance and genomic monitoring are critical to inform public policy and curtail the spread of these highly resistant pathogens.

Discovery of Highly Effective Antibacterial Agents Based on Chalcone-Benzisothiazolinone against Plant Pathogens.

In this study, a series of novel chalcone compounds containing 1,2-benzisothiazolin-3-one were designed, synthesized, and screened for the prevention and control of plant bacterial diseases. The results showed that most of the target compounds displayed excellent antibacterial activities. Especially, F17 (2-(3-(4-cinnamoylphenoxy)propyl)benzo[d]isothiazol-3(2H)-one) exhibited remarkable efficacy against Xanthomonas oryzae pv Oryzae in vitro, with a half effective concentration (EC50) of 0.5 μg/mL, better than that of the commercial antibacterial agent thiodiazole-copper (TC, 56.1 μg/mL). Furthermore, F17 showed excellent effects against rice bacterial leaf blight in vivo, with protective and curative activities of 59.2% and 48.8% at 200 μg/mL, respectively, which were higher than those of TC (38.3% and 36.6%). Moreover, the bacteriostatic mechanism of F17 was elucidated through a series of biochemical experiments. The results indicated that F17 could inhibit the expression of multiple pathogenic factors and induce the host's resistance to disease by enhancing the activities of defense enzymes. Therefore, F17, which revealed the ability to combat plant bacterial diseases by orchestrating the control of multiple factors, might provide a new perspective for solving the problem of plant pathogen resistance. Overall, the results of this work demonstrated that chalcone compounds containing benzisothiazolinone as highly effective antibacterial candidates hold potential for the management of plant bacterial diseases.

Assessing the potential risk of human pathogen resistance to medical antifungal treatments arising from agricultural use of fungicides with the same mode of action

AbstractA mechanistic basis is described for assessment of resistance risk to medical antifungal treatments from agricultural use of fungicides of the same mode of action. The following need to occur in landscape environments for a risk to be posed by dual use: (i) emergence, whereby a resistant strain emerges by mutation and invasion; (ii) selection, whereby a mutation conferring a fitness advantage is selected for in the presence of fungicide; and (iii) exposure of humans to resistant strains from the landscape, potentially resulting in invasive fungal infection. We identify 20 human pathogens for which there is evidence that all three processes above could, in principle, occur. A model is derived to explore what determines resistance emergence and selection in human pathogens in landscape environments. Knowledge gaps are identified in key parameters. The analysis suggests that emergence and selection were particularly affected by fitness cost associated with the resistance mutation(s) and fungicide concentration. Emergence was also determined by the amount of pathogen reproduction (related to pathogen population size). If fungicide resistance is associated with even a small fitness cost, then environments with low fungicide concentrations, such as field soils, may not be conducive to resistance emergence or selection. These general findings were related to a specific case of observational data from the Netherlands for Aspergillus fumigatus. The analysis supports previous work that compost is towards the high‐risk end of the spectrum for this species. Agricultural soils, nonagricultural land and grassland were lower risk.

Expanding the therapeutic window of gramicidin S towards a safe and effective systemic treatment of methicillin-resistant S. aureus infections

The rise of multidrug-resistant bacteria, such as Methicillin-resistant Staphylococcus aureus (MRSA), necessitates the development of new antibacterial therapies. Antimicrobial peptides offer a promising alternative to conventional antibiotics due to their unique mechanisms of action. Gramicidin S exhibits potent bactericidal activity against S. aureus, however, high haemolytic toxicity currently limits its application to topical use. A new series of gramicidin S analogues is presented with rational modifications to the β-turn and β-strand regions, to reduce haemolytic and nephrotoxic effects, while preserving antibacterial potency. The minimum inhibitory concentration (MIC) for each analogue was determined against benchmark methicillin-sensitive S. aureus (MSSA) and MRSA clinical isolates, with toxicity characterised in vitro using human red blood cells and human embryonic kidney cells (HEK-293). Peptide 12 demonstrated a significant two-fold increase in antibacterial activity against both MSSA and MRSA (MIC: 2 μg/mL) compared to gramicidin S (MIC: 4 μg/mL), albeit with increased cytotoxicity. Similarly, peptide 15 showed exceptional efficacy (MIC: 3 μg/mL), but with reduced cytotoxicity, culminating in a two-fold improvement to the therapeutic index (TI) of gramicidin S. Peptides 14 (HC50: 50.48 ± 1.15 μg/mL, IC50: 38.09 μg/mL) and 16 (HC50: 84.09 ± 1.02 μg/mL, IC50: 12.60 μg/mL) also significantly reduced haemolytic toxicity and nephrotoxicity, compared to gramicidin S (HC50: 12.34 ± 0.27 μg/mL, IC50: 6.45 μg/mL). Detailed NMR, CD and computational modelling were used to provide critical insights into how molecular conformation influences both antibacterial potency and cytotoxicity. Collectively, these results expand the therapeutic window of gramicidin S by up to 12-fold, with negligible cytotoxicity observed at concentrations well beyond the acceptable safety threshold, which indicates the potential for safe systemic administration in the treatment of infection caused by resistant pathogens.

Enhancing Antibacterial Activity Against Staphylococcus aureus with Limonene: A Phytomolecule Potentiator

Antimicrobial Resistance (AMR) poses a significant threat to global public health - resulting in millions of death every year. With the rampant misuse of antibiotics, it is estimated that the number of cases that succumb to AMR will only rise. Staphylococcus aureus being one of the major 6 major resistant pathogens is known for developing resistance to antibiotics by various mechanisms - one being the extrusion of antibiotics like ciprofloxacin out of the cell through efflux pumps. Efforts to counter this resistance mechanism in S. aureus include the search for efflux pump inhibitors (EPIs). Natural compounds such as limonene, a phytomolecule found in citrus fruits, show promise as EPIs by potentiating the activity of the antibiotic. This paper aims to determine the optimal combination of ciprofloxacin and limonene concentrations required to improve the susceptibility of S. aureus to ciprofloxacin.

Distribution and Antimicrobial Susceptibility Profiles of Pathogens in Patients With Esophageal Cancer From 2013 to 2022: A Retrospective Study.

Pathogenic microbial infections are closely related to the development and prognosis of esophageal cancer. The distribution and resistance of pathogens in different diseases are regional and gradually change over time. This study aimed to determine the distribution and drug resistance of pathogens isolated from patients with esophageal cancer and provide a reference for the rational use of antibiotics. The results of strain identification and antimicrobial susceptibility testing of pathogens in patients with esophageal cancer from January 2013 to December 2022 at our hospital were retrospectively analyzed. SPSS Statistics 26.0 (IBM) and R software 4.3.1 were used for data analysis. In total, 2322 non-repetitive pathogens were isolated from 14,037 samples. Of all strains, 1713 (73.77%) were Gram-negative bacteria, 483 (20.80%) were Gram-positive bacteria, and 126 (5.43%) were fungi. The top 10 pathogens were Pseudomonas aeruginosa (19.81%), Stenotrophomonas maltophilia (12.88%), A. baumannii (9.91%), Klebsiella pneumoniae (9.82%), Staphylococcus aureus (7.54%), Candida albicans (3.92%), Staphylococcus epidermidis (3.19%), Escherichia coli (3.14%), Enterococcus faecalis (2.97%), and Serratia marcescens (2.15%). The isolation rate of S. maltophilia showed an upward trend (p < 0.05). The resistance rates of P. aeruginosa, S. maltophilia, A. baumannii, and Enterobacteriaceae bacteria to some common antibiotics showed a tendency to change (p < 0.05), and 2019 became a turning point to some extent. All common Gram-positive pathogens were sensitive to vancomycin, except for three Enterococcus spp. isolates that showed intrinsic resistance. The prevalence of MRSA was 65.14% (114/175) in this study. In addition, the resistance rates of MRSA and MSSA to moxifloxacin, ciprofloxacin, levofloxacin, erythromycin, clindamycin, and penicillin were significantly different (p < 0.001). Pathogens are diverse in patients with esophageal cancer, with the most common being P. aeruginosa, followed by S. maltophilia. The pathogens exhibited different patterns of resistance. Antibiotics should be used rationally according to pathogen resistance patterns.

Impact of phytoceuticals: Thymol-loaded zein-based nano-antimicrobials to combat resistant zoonotic pathogen

Campylobacter jejuni related gastrointestinal infections are challenging to overcome due to emerging antimicrobial resistance that poses global public health concerns. The development of biopolymeric nanosystems encapsulating natural antimicrobials serves as an alternative-medicine based on phytoceuticals. Thymol, an essential ingredient extracted from the thyme plant (Thymus vulgaris), and oregano plant (Origanum vulgare) exhibits a wide range of applications including anti-inflammatory, antibacterial, and antioxidant properties. However, its bioavailability, low stability, and poor water solubility severely limit its applications. Herein, zein nanosystems encapsulating thymol (TH-ZNs) were successfully fabricated to enhance the antibacterial and antibiofilm potential of thymol against foodborne multidrug-resistant C. jejuni. Through the antisolvent precipitation technique, physically stable nanosystems were obtained exhibiting a high encapsulation efficiency of 87 ± 0.5 %. Scanning electron microscopy revealed slightly rough surface morphology of TH-ZNs. FTIR spectroscopy elucidated hydrophobic interactions between thymol and zein which facilitates the successful encapsulation of thymol. Dynamic light scattering (DLS) studies revealed that the entrapment of thymol in ZNs increased the size from 202 ± 1.4 nm to 212 ± 1 nm, whereas zeta potential values were reduced from −42 ± 3 mV to −37 ± 2 mV in the case of void and TH-ZNs, respectively. Furthermore, TH-ZNs exhibited higher antimicrobial and antibiofilm efficacy against C. jejuni as compared to free thymol for a longer period. These results indicate that TH-ZNs inhibited bacterial growth while being non-cytotoxic, thus improving the overall efficiency of phytoceuticals to develop alternative nanotherapeutics to combat the resistant zoonotic pathogen.

Plant secondary metabolites-mediated plant defense against bacteria and fungi pathogens

Plant diseases caused by pathogenic bacteria and fungi are major threats to both wild plants and crops. To counteract these threats, plants have evolved various defense mechanisms, including the production of plant secondary metabolites (PSMs). These compounds, such as terpenoids, phenolics, alkaloids, and glucosinolates, offer a versatile, efficient, and cost-effective means of pathogen resistance. The traditional pathogen management methods relying on synthetic microbicides are often environment unfriendly. In contrast, PSMs provide promising alternative way due to their high efficiency and environmental benefits. This article reviews the categories, biosynthetic pathways, mechanisms of actions, and the commercialization of the PSMs to enhance our understanding of their pathogen resistance capabilities. The goal is to develop sustainable disease management strategies using PSM-based bactericides and fungicides.