Resistant Bacteria Research Articles

Multidrug Resistance in Stray Cats of The North Surabaya Region, East Java, Indonesia

Stray cats survive by getting food or drink that is available in the environment, correspondingly, stray cats have relatively high exposure to antibiotic resistance obtained from resistant bacteria found in the environment. The present study was conducted to determine patterns of multidrug resistance and Escherichia coli resistance in stray cats. A total of 50 stray cat anal swab samples were taken randomly from the previously recorded stray cat population in the Surabaya area, East Java, Indonesia. Samples were brought using buffered peptone water. They were cultured on MacConkay Agar differential selective media, and all suspicious colonies of Escherichia coli were examined by biochemical tests. Isolates were then identified, and susceptibility testing was performed according to the Clinical and Laboratory Standards Institute. The results of the resistance test indicated that the multidrug resistance in Escherichia coli bacteria taken from cats was 14.6% (7/48). The high antibiotic resistance of Escherichia coli bacteria in stray cats, which were resistant to many drugs, provides an early warning of environmental health. Environmental health is closely related to animal and human health, especially antibiotic resistance.

Alternatives of Antibiotics in Animal Agriculture: One Health Perspective

Due to the increasing trend of antimicrobial resistance bacteria and the increase of antimicrobial resistance genes, there is an urgent need to develop alternatives to antibiotics. This review evaluates the advances and perceptions of alternatives to antibiotics. The mode of action, application and perspective of alternatives such as clay minerals, probiotics, prebiotics, inhibitors such as quorum sensing inhibitors, biofilms inhibitors, bacterial virulence inhibitors, antimicrobial peptides, phytogenic compounds like organic acids, essential oil and herbs, bacteriophages, nanoparticles, vaccines, fecal microbiota transplant, immunity modulating stimulants and bacteriocins are discussed in this review. If used with proper strategies, these alternatives can replace antibiotics in livestock. These alternatives not only better cope with antimicrobial resistance but also can help in efficient animal growth, production and disease control. However, till now, none of the alternatives has been proven to efficiently replace antibiotics on a large scale, though, they appeared to be a partial replacement to antibiotics. These natural alternatives are promising to improve the overall health of the environment, animals and humans. Lastly, the idea of one health was adopted in recognition of the fact that animals and people share many infectious diseases and are connected in addition to existing in the same environment. Using one health concept, the World Health Organization (WHO), Food and Agriculture Organization (FAO), and World Organization for Animal Health (OIE) developed several action plans to tackle antibiotic resistance.

Effects of transgenic modification on the bacterial communities in different niches of maize under glyphosate toxicity

Transgenic glyphosate-resistant maize has emerged as a way to expand the use of glyphosate for weed control. Studying the microbiome in the tissues and rhizosphere soil of transgenic plants is vital for understanding the glyphosate-resistant mechanism and optimizing the transgenic design of crops. In our study, the expression of a mutant cp4epsps gene in transgenic maize, which confers tolerance to glyphosate, was performed using the maize variety Xianyu 335 as the genetically modified acceptor line. This transgenic modification did not affect the initial bacterial community in the leaf, stem, or root of maize, but promoted a differential bacterial community in the rhizosphere soil. Under glyphosate application, the abundance of beneficial bacteria involved in N fixation and P solubilization in plant tissues and the rhizosphere soil of glyphosate-resistance maize were higher than those in the glyphosate-sensitive maize. In contrast, the abundance of pathogens had the opposite trend, suggesting that the enhanced health of transgenic maize prevented microbiome deterioration under glyphosate. The re-inoculation of bacterial strains isolated from glyphosate-resistance maize into the leaf and rhizosphere soil of glyphosate-sensitive maize resulted in an enhanced photosynthetic capacity in response to glyphosate, demonstrating the vital role of specific bacteria for glyphosate resistance. Our study provides important evidence of how transgenic maize tolerance to herbicides affects the bacterial communities across the maize niches under glyphosate toxicity.

Promising antibiofilm formation: Liquid phase pulsed laser ablation synthesis of Graphene Oxide@Platinum core-shell nanoparticles.

The increasing prevalence of multi-drug resistance in pathogenic bacteria has rendered antibiotics ineffective, necessitating the exploration of alternative antibacterial approaches. Consequently, research efforts have shifted towards developing new antibiotics and improving the efficacy of existing ones. In the present study, novel core shell graphene oxide@platinum nanoparticles (GRO@Pt-NPs) and their unchanging form have been synthesized using the two-step pulsed laser ablation in liquid (PLAL) technique. The first step involved using the graphene target to create graphene nanoparticles (GRO-NPs), followed by the ablation of GRO-NPs inside platinum nanoparticles (Pt-NPs). To characterize the nanoparticles, various methods were employed, including UV-VIS, transmission electron microscopy (TEM), energy dispersive X-ray (EDX), mapping tests, and X-ray diffraction (XRD). The anti-bacterial and anti-biofilm properties of the nanoparticles were investigated. TEM data confirm the creation of GRO@Pt-NPs. The average particle size was 11 nm for GRO-NPs, 14 nm for Pt-NPs, and 26 nm for GRO@Pt-NPs. The results demonstrate that the created GRO@Pt-NPs have strong antibacterial properties. This pattern is mostly produced through the accumulation of GRO@Pt-NPs on the bacterial surface of Klebsiella pneumoniae (K. pneumoniae) and Enterococcus faecium (E. faecium). The inhibition zones against K. pneumoniae and E. faecium when GRO-NPs were used alone were found to be 11.80 mm and 11.50 mm, respectively. For Pt-NPs, the inhibition zones of E. faecium and K. pneumoniae were 20.50 mm and 16.50 mm, respectively. The utilization of GRO@Pt-NPs resulted in a significant increase in these values, with inhibitory rates of 25.50 mm for E. faecium and 20.45 mm for K. pneumoniae. The antibacterial results were more potent in the core-shell structure than the GRO-NPs alone or Pt-NPs alone. The current work uses, for the first time, a fast and effective technique to synthesize the GRO@Pt-NPs by PLAL method, and the preparation has high clinical potential for prospective use as an antibacterial agent.

Green-synthesized silver nanoparticles from Zataria multiflora as a promising strategy to target quorum sensing and biofilms in Pseudomonasaeruginosa

The global challenge to human health is significantly heightened by the resistance of harmful bacteria to antimicrobial treatments. Given the limited advancement in developing new antimicrobial medications, exploring innovative strategies is imperative to tackle the challenge of resistance to multiple drugs. Furthermore, there is a growing emphasis on the environmentally friendly synthesis of nanoparticles with potent medicinal attributes, specifically those targeting virulence, to combat the rise of multidrug resistance. Focusing on the inhibition of virulence factors and biofilms influenced by quorum sensing has become a promising and novel strategy in the development of anti-infective drugs. An aqueous extract of Zataria multiflora leaves was used to create green-synthesized silver nanoparticles, or AgNPs. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and UV–visible absorption spectroscopy were used to characterize the AgNPs. The impact of AgNPs on the virulence factors and biofilms of Pseudomonas aeruginosa PAO1, mediated by quorum sensing, was assessed at concentrations below the minimum inhibitory concentration (sub-MIC). Sub-MIC concentrations of Green-synthesized AgNPs inhibited various P. aeruginosa virulence factors, including bacterial motility (89 % inhibition), pyocyanin production (81.48 % inhibition), pyoverdin production (55.80 % inhibition), elastase activity (87.43 % inhibition), exoprotease activity (75.60 % inhibition), and rhamnolipid production (71.28 % inhibition). Additionally, these AgNPs demonstrated 80 % inhibition of P. aeruginosa biofilms. The in vitro efficacy of green-synthesized AgNPs against P. aeruginosa can be utilized for the creation of alternative therapeutic agents for managing bacterial infections, particularly for topical application in cases such as wound infections. Additionally, they can be used for surface coating to inhibit the attachment of bacteria to medical devices.

Antibiotic susceptibility pattern of carbapenem resistant Escherichia coli and Klebsiella pneumoniae, 2019

The rise in the prevalence of carbapenem resistant bacteria worldwide has made the treatment of nosocomial infections challenging. This is because carbapenem resistant bacteria harbor multiple resistance genes aside the carbapenemase genes. This study was conducted to determine the susceptibility pattern of carbapenem resistant isolates of Escherichia coli and Klebsiella pneumoniae. Previously isolated and characterized carbapenem resistant E. coli and K. pneumoniae were screened for their susceptibility to ceftriaxone, trimethoprim-sulphamethoxazole, doxycycline, amikacin, gentamicin, nalidixic acid, chloramphenicol, colistin, tigecycline and fosfomycin by the Kirby Bauer technique. EUCAST and CLSI breakpoints were used to interpret the zones of inhibition. High level of resistance was observed among the isolates to ceftriaxone (100.00 %), trimethoprim-sulphamethoxazole (100.00 %) and doxycycline (83.33 %). Two-third of the isolates (66.67 %) were observed to be susceptible to amikacin, while 33.33 % of the isolates were gentamicin and nalidixic acid susceptible. Susceptibility to chloramphenicol and colistin was recorded in 16.67 % of the isolates while all the screened isolates (100.0 %) were susceptible to fosfomycin and tigecycline. A higher antibiotic resistance rate was observed among isolates habouring carbapenemase genes (blaNDM, blaOXA or both). The MAR indices of the carbapenem resistant isolates ranged between 0.46 and 0.82. So also, all the isolates screened were observed to be resistant to multiple antibiotics, hence MDR isolates. In conclusion, the carbapenem resistant isolates were resistant to multiple antibiotics but were however susceptible to tigecycline, fosfomycin and amikacin.

Thymus algeriensis essential oil: Phytochemical investigation, bactericidal activity, synergistic effect with colistin, molecular docking, and dynamics analysis against Gram-negative bacteria resistant to colistin

Due to the increasing resistance prevalence to the last line of antibiotics, such as colistin, and the rising threat of multi-drug resistant bacteria, it is crucial to find alternative therapeutic options. The current study focuses on evaluating antibacterial activities alone and in combination with colistin of Thymus algeriensis essential oil (TA-EO) against colistin-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli co-harboring mcr-1 gene. GC/MS was used to determine the chemical composition of TA-EO. Disc diffusion and microdilution techniques were used to evaluate the antimicrobial activities of TA-EO. Synergism between colistin and TA-EO was evaluated by checkerboard assay. The major compounds of TA-EO were docked with known enzymes involved in resistance to colistin, as well as the biosynthesis of peptidoglycan and amino acids. GC/MS revealed that TA-EO was of carvacrol chemotype (67.94 %). The TA-EO showed remarkable antibacterial activities against all Gram-negative bacterial strains, with the diameter of inhibition zones varied between 30 and 50 mm and a ratio MBC/MIC equal to 1 for the vast majority of bacterial isolates. Interestingly, the checkerboard showed synergism between TA-EO and colistin against colistin-resistant Escherichia coli co-harboring mcr-1 gene (FICI˂1) and reduced the MIC of colistin by 16- to 512-fold and those of TA-EO by 4- to 16-fold. The docking study demonstrated that carvacrol had high binding free energies against MCR-1, a phosphoethanolamine transferase extracellular domain, and its catalytic domain implicated in resistance to colistin, and undecaprenyl pyrophosphate synthase in complex with magnesium which is involved in bacterial peptidoglycan biosynthesis. The molecular dynamics study for 100-ns also revealed the stability of the MCR-1/carvacrol complex with a constant surface area over the simulation. These results support using carvacrol or TA-EO as a bactericidal agent, either alone or in combination with colistin, to treat infections caused by colistin-resistant Gram-negative bacteria.

Essential oils: a potential alternative with promising active ingredients for pharmaceutical formulations in chronic wound management.

Chronic wound is a major clinical challenge that complicates wound healing, mainly associated with bacterial biofilms. Bacterial burden damages tissue and persists inflammation, failing to granulate, leading to morbidity and mortality. Various therapeutic strategies and approaches have been developed for chronic wound healing in clinical practice. As treating biofilm infection is crucial in chronic wounds, a potent antibiofilm agent, essential oils have been explored extensively for their therapeutic properties and as a replacement for antibiotic therapy. Currently, several studies on essential oils and their active compounds in therapeutics, such as adjunctive therapies, nanotechnology-based treatment and their drug delivery systems, help heal chronic wounds. The antimicrobial, anti-inflammatory and antioxidant properties of essential oils make them distinct and are renowned as natural remedies to improve the healing of infected chronic wounds. Consequently, it accelerates wound closure by reducing inflammation, increasing angiogenesis and tissue regeneration. This review focuses on different essential oils and their active compounds that are exploited for the treatment of biofilm infection, chronic inflammation and wound healing. Thus, an effective novel treatment can be developed to improve the current treatment strategy to overcome multidrug resistance bacteria or antibiotic resistance in various chronic wound infections that support wound healing.

Progress in antibacterial applications of nanozymes.

Bacterial infections are a growing problem, and antibiotic drugs can be widely used to fight bacterial infections. However, the overuse of antibiotics and the evolution of bacteria have led to the emergence of drug-resistant bacteria, severely reducing the effectiveness of treatment. Therefore, it is very important to develop new effective antibacterial strategies to fight multi-drug resistant bacteria. Nanozyme is a kind of enzyme-like catalytic nanomaterials with unique physical and chemical properties, high stability, structural diversity, adjustable catalytic activity, low cost, easy storage and so on. In addition, nanozymes also have excellent broad-spectrum antibacterial properties and good biocompatibility, showing broad application prospects in the field of antibacterial. In this paper, we reviewed the research progress of antibacterial application of nanozymes. At first, the antibacterial mechanism of nanozymes was summarized, and then the application of nanozymes in antibacterial was introduced. Finally, the challenges of the application of antibacterial nanozymes were discussed, and the development prospect of antibacterial nanozymes was clarified.

Prevalence and molecular characterization of ESBL/pAmpC producing faecal Escherichia coli strains with widespread detection of CTX-M-15 isolated from healthy poultry flocks in Eastern Algeria

The intensification of livestock farming has led to the widespread use of massive amounts of antibiotics worldwide. Poultry production, including white meat, eggs and the use of their manure as fertiliser, has been identified as one of the most crucial reservoirs for the emergence and spread of resistant bacteria, including E. coli in poultry as an important opportunistic pathogen representing the greatest biological hazard to human and wildlife health. Thus, this study aimed to analyse E. coli in the faecal carriage of healthy poultry flocks and to investigate the phenotypic and genotypic characteristics of antimicrobial resistance, including integrons genes and phylogenetic groups. A total of 431 cloacal swabs from apparently healthy poultry from four regions in Eastern Algeria from December 2021 to October 2022. 360 E. coli were isolated; from broilers (n = 151), broiler breeders (n = 91), laying hens (n = 72), and breeding hens (n = 46). Among this, 281 isolates exhibited multidrug resistance (MDR) phenotype, 17 of the 360 E. coli isolates exhibited ESBL, and one isolate exhibited both ESBL/pAmpC. A representative collection of 183 among 281 MDR E. coli was selected for further analysis by PCR to detect genes encoding resistance to different antibiotics, and sequencing was performed on all positive PCR products of blaCTX-M and blaCMY-2 genes. Phylogenetic groups were determined in 80 E. coli isolates (20 from each of the four kinds of poultry). The blaCTX-M gene was found in 16 (94.11 %) ESBL-producing E. coli isolates within 11 strains co-expressing the blaSHV gene and 8 strains co-expressing the blaTEM gene. Sequence analysis showed frequent diversity in CTX-M-group-1, with blaCTX-M-15 being the most predominant (n = 11), followed by blaCTX-M-1 (n = 5). The blaCMY-2 gene was detected only in one ESBL/pAmpC isolate. Among the 183 tested isolates, various antimicrobial resistance genes were found (number of strains) blaTEM (n = 121), blaSHV (n = 12), tetA (n = 100), tetB (n = 29), sul1(n = 67), sul2 (n = 32), qnrS (n = 45), qnrB (n = 10), qnrA (n = 1), catA1(n = 13), aac-(6′)-Ib (n = 3). Furthermore, class 1 and class 2 integrons were found in 113 and 2 E. coli, respectively. The isolates were classified into multiple phylogroups, including A (35 %), B1 (27.5 %), B2 and D each (18.75 %). The detection of integrons and different classes of resistance genes in the faecal carriage of healthy poultry production indicates that commensal E. coli could potentially act as a reservoir for antimicrobial resistance, posing a significant One Health challenge encompassing the interconnected domains of human, animal health and the environment. Here, we present the first investigation to describe the diversity of blaCTX-M producing E. coli isolates with widespread detection of CTX-M-15 and CTX-M-1 in healthy breeders (Broiler and breeding hens) in Eastern Algeria.

Antibiotic susceptibility of orofacial infections in Bratislava: a 10-year retrospective study

ObjectivesAim of this study was to analyse causal microbiological agents and their bacterial resistance in orofacial infections requiring hospital admission.Materials and methodsPresented is a 10-year retrospective study of patients hospitalised at a single department in 2014–2023. 744 patients were involved. In the statistical analysis, following data was evaluated: causal microbes and their resistance to Penicillin, Amoxicillin-Clavulanate, Clindamycin and Metronidazole.ResultsMost frequent aetiology was odontogenic with causal tooth in socket (n = 468; 62,9%), followed by odontogenic – post extraction (n = 152; 20.4%), jaw fracture (n = 41; 5.5%), sialadenitis n = 31 (4.2%), osteonecrosis n = 22 (3.0%), oncological diagnosis in head and neck (n = 17; 2.3%), unknown (n = 10; 1.3%) and multiple factors (n = 3; 0.4%). 408 patients (54.8%) underwent extraoral abscess revision, 336 patients (45.2%) patients were treated locally without extraoral revision. In odontogenic group with tooth still present, superior CRP (m = 145.8 mg/l; SD = 117.7) and leukocyte values (m = 13.6*109l; SD = 6.6) were observed in comparison to other groups. There were 698 cultivated bacteria in 362 patients. Most frequent bacteria were Streptococci (n = 162; 23.2%), Prevotella (n = 83; 11.2%) and Parvimonas (n = 65; 9.3%). Clindamycin resistance was highest (n = 180 resistant bacteria; 25.8%), followed by Metronidazole (n = 178; 25.5%), Penicillin (n = 107; 15.3%) and Amoxicillin-Clavulanate (n = 34; 4.9%).ConclusionsOrofacial infections in head and neck region are mostly of odontogenic origin with causal tooth still in socket. Causal bacteria show a high antibiotic resistance rate, especially to Clindamycin and Metronidazole.Clinical RelevanceAcquired data will be used to determine guidelines for empirical antibiotic prescription in cases of orofacial infections.

Cu2O-SnO2-PDA heterozygous nanozyme doped hydrogel mediated conglutinant microenvironment regulation for wound healing therapy

Bacterial infection significantly hinders the wound healing process. Overuse of antibiotics has led to the rise of drug resistance in bacteria, making the development of smart medical dressings that promote wound healing without antibiotics, a critical need. In this study, Cu₂O-SnO₂-PDA (PCS) nanoenzymes with Fenton-like activity and high photothermal conversion efficiency were developed. These nanoenzymes were then incorporated into a hydrogel through cross-linking of acrylamide (AM) and N-[Tris-(hydroxymethyl)methyl] acrylamide (THMA), forming a tough, highly-adhesive, and self-healing composite hydrogel (AT/PCS) with antimicrobial properties. The AT/PCS hydrogel exhibits excellent mechanical strength and adhesion, facilitating increased oxygen levels and strong adherence to the wound site. Moreover, it effectively regulates the wound microenvironment by combining synergistic chemodynamic therapy (CDT) and photothermal therapy (PTT) for antibacterial treatment. The AT/PCS hydrogel enhances collagen deposition and expedites wound healing in a rat model, largely due to its potent antibacterial properties.

Investigating the Efficacy of Various Natural Products in Raw Form against Multidrug-Resistant Bacteria.

The alarming increase in antibiotic resistance urges alternative and efficacious antimicrobial solutions. Historically, medicinal plants have been used for therapeutic purposes, such as relieving pain and healing wounds. However, the evaluation of the natural therapeutic effects of medicinal plants in a manner that resembles how humans typically consume them is lacking. Therefore, in this study, many medicinal plants known to have some antimicrobial effects, including Frankincense, Garlic, Myrrh, and Ginger, were evaluated for their direct antibacterial activity in raw form. The direct antimicrobial activity of medicinal plants was evaluated against a variety of Gram-positive and Gram-negative bacterial strains, such as Staphylococcus aureus (S. Aureus), Acinetobacter baumannii and Klebsiella pneumoniae using agar well diffusion method and turbidity measurements in suspension culture. Out of all the tested medicinal plants, only raw garlic (Allium sativum) powder, when dissolved in water or vinegar, offered a straightforward antibacterial activity. A combination of garlic extract and vinegar increased antibacterial activity. Aqueous garlic extracts displayed robust antimicrobial activity against many resistant bacteria. Other medicinal plants used in this study had absent or minimal antibacterial effects. Only garlic in its raw form was effective against antibiotic-resistant bacteria. The increase in the antibacterial activity of garlic when combined with vinegar suggests the synergistic activity of garlic. The straightforward antibacterial action of raw garlic may be strategically harnessed to combat the continuous challenge of increasing antibiotic resistance. This work promotes additional testing of more natural products (in raw form) and assesses their therapeutic effects clinically.

Phenotypic and genotypic perspectives on detection methods for bacterial antimicrobial resistance in a One Health context: research progress and prospects.

The widespread spread of bacterial antimicrobial resistance (AMR) and multidrug-resistant bacteria poses a significant threat to global public health. Traditional methods for detecting bacterial AMR are simple, reproducible, and intuitive, requiring long time incubation and high labor intensity. To quickly identify and detect bacterial AMR is urgent for clinical treatment to reduce mortality rate, and many new methods and technologies were required to be developed. This review summarizes the current phenotypic and genotypic detection methods for bacterial AMR. Phenotypic detection methods mainly include antimicrobial susceptibility tests, while genotypic detection methods have higher sensitivity and specificity and can detect known or even unknown drug resistance genes. However, most of the current tests are either genotypic or phenotypic and rarely combined. Combining the advantages of phenotypic and genotypic methods, combined with the joint application of multiple rapid detection methods may be the trend for future AMR testing. Driven by rapid diagnostic technology, big data analysis, and artificial intelligence, detection methods of bacterial AMR are expected to constantly develop and innovate. Adopting rational detection methods and scientific data analysis can better address the challenges of bacterial AMR and ensure human health and social well-being.

Biological analysis of phage vB_AhaP_PT2 and treatment rescued crucian carp infected with Aeromonas hydrophila

Phage therapy is an alternative approach to overcoming the problem of multidrug resistance in bacteria. In this study, we isolated and purified a virulent phage named vB_AhaP_PT2 from A. hydrophila-TPS. We examined the biological characteristics and genome sequences of vB_AhaP_PT2. After intraperitoneal injection of bacteriophage (8 × 107 PFU/mL) into crucian carp, most of the phage distributed in the liver, spleen, kidney, intestine, and peripheral blood, and disappeared within 72 h. No substantial adverse symptoms were found in major organs after receiving phage injections continuously for 14 days. Vitro and Vivo results indicated that phage can effectively eliminate A. hydrophila-TPS. The phage vB_AhaP_PT2 (8 × 107 PFU/mL, 100 μL) can effectively protect the fish that exhibited a double median lethal dose of bacteria (2 × 106 CFU/fish). Although phage vB_AhaP_PT2 triggered the generation of phage-specific antibodies in carp, when the antibody titer was maximum, 8 × 107 PFU doses of bacteriophage could still protect crucian carp with lethal bacterial infections, the survival rate could reach 80 %. We also found that members of the genus Aeromonas could enter and colonize the intestine. The phage vB_AhaP_PT2 reduced the number of colonies of the genus Aeromonas. However, no significant changes were observed in α-diversity and β-diversity parameters, which suggested that the consumed phage had little effect on the intestine microflora. All the above results suggested that vB_AhaP_PT2 was a safe and effective therapeutic that can be considered as a potential tool to treat the infection caused by A. hydrophila-TPS in aquaculture.

Application of self-assembled antibacterial nanofiber loaded oriented artificial skin in infected diabetic-related wound regeneration

Diabetic patients develop wounds that exhibit delayed healing, prolonged inflammatory responses, and slower epithelialization kinetics compared to non-diabetic patients. Diabetic foot ulcers(DFUs) affect approximately 18.6 million people worldwide. The presence of a high glucose microenvironment in DFUs results in the significant accumulation of bacterial infection and advanced glycation end products (AGEs). To solve this, a self-assemble antibacterial nanofiber(ANF) loaded oriential artificial skin (ANF@OAS) was introduced in this research, which is consisted of L/D-phenylalanine derivatives coupled the natural antimicrobial peptides. The ANF@OAS can effectively reduce AGEs production and suppress multiple resistant bacteria. Additionally, the ANF@OAS can suppress infection and stimulate wound healing in infected diabetic mice.

Enhanced bacterial disinfection of multi-drug resistance bacteria by PCN@AgI heterojunction under visible light irradiation

Pathogenic bacterial infections have become a continuing threat to human health over the past decade, the development of novel antibacterial agents or strategies against drug-resistance bacteria is highly desirable. Although porphyrin-based metal organic frameworks (PCN) are important photosensitizers (PSs) for photodynamic antibacterial treatments, they are inefficient for killing gram-negative bacteria such as Escherichia coli. Herein, PCN@AgI heterojunction was prepared as a novel and potent multifunctional antibacterial agent to combat bacteria including drug-resistance bacteria such as extended-spectrum β-lactamaseEscherichia coli (ESBL) under visible light irradiation in vitro, attributing to the cooperation of the generated ROS and released Ag+ as well as GSH-depleting ability. Compared to pristine PCN, the formation of heterojunction between AgI and PCN facilitated the sufficient separation of the produced electron- hole pairs, leading to enhanced photocatalytic antibacterial capability by producing sufficient ROS. Furthermore, its GSH-depleting ability due to its oxidase-like behavior further boosted its antibacterial capability. Significantly, in vivo studies demonstrated that PCN@AgI heterojunction could promote the healing of E. coli-infected wound on rice back with high biosafety. These findings manifested that PCN@AgI heterojunction was a good potential antibacterial therapeutic agent and may hold promise in bacteria-infected wound healing.

The antimicrobial resistance landscape of slaughterhouses in western Kenya: A microbiological case study

Slaughterhouses may be hotspots for the transmission of antimicrobial resistant (AMR) pathogens. To obtain information on the AMR landscape in Kenyan slaughterhouses, we collected swabs of the environment, animal carcasses, and workers. Bacterial isolates were identified in 101/193 (52.3 %) samples, and most showed resistance to streptomycin (68.7 %), ampicillin (48.7 %), and tetracycline (42.5 %). Multi drug resistance was exhibited by 35/80 isolates (43.8 %; 95 % CI: 33.2–54.9 %), while Extended Spectrum Beta Lactamase was expressed in 5/80 isolates (6.3 %; 95 % CI: 2.6–14.3 %). These findings illustrate the presence of resistant bacteria throughout the slaughterhouse environment, posing a risk to workers and meat consumers and highlighting the need for an integrated surveillance system along the food chain.

Evaluation of an expanded antibiotic resistance gene panel on prediction of antimicrobial susceptibility results for Gram-negative bacteria in blood cultures.

Prediction of Gram-negative bacteria resistance through detection of resistance genes is complex. This study evaluated a novel, direct-from-blood or bacterial isolate multiplexed PCR for the detection of 17 resistance genes, and evaluated the prediction of antimicrobial susceptibility.

Lysine and valine weaken antibiotic resistance in Salmonella Typhimurium induced by disinfectant stress

Disinfectants are widely used in food production and environmental sanitation to prevent illness, but bacteria resistance to these disinfectants and co-resistance to antibiotics pose a threat to public health. This study investigated the impact of commonly used disinfectants on the resistance of Salmonella Typhimurium (ST) to disinfectants and antibiotics, and explored the metabolic mechanisms underlying the resistance changes. The results showed that subinhibitory concentrations of disinfectants had a minor impact on the resistance of ST to four disinfectants. However, chlorine-containing disinfectants stress enhanced bacteria resistance to ampicillin, while quaternary ammonium compounds stress increased resistance to tetracycline and gentamicin. Untargeted metabolomics analysis revealed significant changes in glutathione metabolism and lysine and valine degradation pathways after disinfectant exposure. Specifically, ST activated lysine decarboxylation, leading to a significant decrease in lysine levels after benzalkonium chloride exposure, while valine and leucine degradation pathways were activated by sodium hypochlorite stress. The addition of downregulated L-lysine and L-valine increased the sensitivity of ST to antibiotics, providing further evidence for the findings of metabolomics. This study provides guidance for the proper use of disinfectants in food processing and establishes a strategy based on metabolomics to control antibiotic-resistant bacteria.