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Author(s): Atreyo Chakraborty [1] Introduction[sup.[1]] Pre- and post-exposure prophylaxis has been gaining interest in the recent decade for the prevention of various sexually transmitted diseases. This is partly fuelled by [...]

Plasticity in gene expression allows bacteria to adapt to diverse environments. This is particularly relevant in the dynamic niche of the human intestinal tract; however, transcriptional networks remain largely unknown for gut-resident bacteria. Here we apply differential RNA sequencing (RNA-seq) and conventional RNA-seq to the model gut bacterium Bacteroides thetaiotaomicron to map transcriptional units and profile their expression levels across 15 in vivo-relevant growth conditions. We infer stress- and carbon source-specific transcriptional regulons and expand the annotation of small RNAs (sRNAs). Integrating this expression atlas with published transposon mutant fitness data, we predict conditionally important sRNAs. These include MasB, which downregulates tetracycline tolerance. Using MS2 affinity purification and RNA-seq, we identify a putative MasB target and assess its role in the context of the MasB-associated phenotype. These data-publicly available through the Theta-Base web browser ( http://micromix.helmholtz-hiri.de/bacteroides/ )-constitute a valuable resource for the microbiome community.

Chronic myeloid leukemia (CML) is initiated and maintained by BCR::ABL which is clinically targeted using tyrosine kinase inhibitors (TKIs). TKIs can induce long-term remission but are also not curative. Thus, CML is an ideal system to test our hypothesis that transcriptome-based state-transition models accurately predict cancer evolution and treatment response. We collected time-sequential blood samples from tetracycline-off (Tet-Off) BCR::ABL-inducible transgenic mice and wild-type controls. From the transcriptome, we constructed a CML state-space and a three-well leukemogenic potential landscape. The potential's stable critical points defined observable disease states. Early states were characterized by anti-CML genes opposing leukemia; late states were characterized by pro-CML genes. Genes with expression patterns shaped similarly to the potential landscape were identified as drivers of disease transition. Re-introduction of tetracycline to silence the BCR::ABL gene returned diseased mice transcriptomes to a near healthy state, without reaching it, suggesting parts of the transition are irreversible. TKI only reverted the transcriptome to an intermediate disease state, without approaching a state of health; disease relapse occurred soon after treatment. Using only the earliest time-point as initial conditions, our state-transition models accurately predicted both disease progression and treatment response, supporting this as a potentially valuable approach to time clinical intervention, before phenotypic changes become detectable.

Oxygen (O2) electroreduction offers a green approach for singlet oxygen (1O2) synthesis in wastewater contaminants detoxification. However, traditional single O2 activation on single‐metal catalytic sites seriously suffers from the kinetically‐unfavorable desorption of adsorbed superoxide species (•O2−*/•OOH*). Here, we demonstrate a novel dual O2 coactivation pathway on shortened Fe1−OV−Ti sites for superior 1O2 electrosynthesis through a rapid disproportionate process between surface‐confined •O2−*/•OOH*. Theoretical calculations combined with in situ electrochemical spectroscopies demonstrated that the shortened distance between Fe single atom and adjacent unsaturated Ti atom facilitates the direct recombination of surface‐confined Fe−•OOH and Ti−•OO− to yield 1O2, bypassing the formidable •O2−*/•OOH* desorption process. Impressively, Fe1−OV−Ti could realize an excellent 1O2 electrosynthesis rate of 54.5 μmol L−1 min−1 with an outstanding 1O2 selectivity of 97.6 % under neutral condition, surpassing that of Fe1−O−Ti (27.1 μmol L−1 min−1, 91.7 %). Using tetracycline (TC) as a model pollutant, the resulting Fe1−OV−Ti electrode achieved nearly 100 % degradation in 120 min at −0.6 V, meanwhile preventing the generation of toxic intermediates. This study provides a new 1O2 electrosynthesis strategy by controlling the distance of adjacent catalytic sites for the coactivation of dual molecular oxygen. [ABSTRACT FROM AUTHOR]

Purpose: Since decades, numerous antibiotics have been used to treat different bacterial illnesses; among these, tetracycline is one of the commonly used antibiotics, which has led to development of bacterial resistance. To tackle this critical issue, we have developed a novel, biocompatible nanodrug that improves the antibacterial activity of tetracycline by conjugating it with copper oxide nanoparticles, thereby addressing the problem of multidrug resistance in bacteria. Methods: In this study, using unipot approach, tetracycline conjugated copper oxide nanoparticles were synthesized where tetracycline act as reducing as well as stabilizing agent. These nanoparticles were characterized by different analytical and microscopic technique. For statistical analysis, FFD and CCD model were employed to assess the effect of various parameters (concentration, pH, temperature and time). Results: The synthesis of nanoparticles was confirmed through different techniques. Synthesized nanoparticles exhibited the highest antibacterial activity against various microbes including multi‐drug resistant microbes compared to its individual constituents. DPPH and ABTS assays revealed high antioxidant activity of nanoparticles whereas, biocompatibility was assessed via MTT assay. The drug release profile confirms the sustained release of tetracycline molecules. Conclusions: We have successfully developed tetracycline conjugated copper oxide nanoparticles exhibiting potent antibacterial, antioxidant and biocompatible activity. [ABSTRACT FROM AUTHOR]

The application of antibiotics has advanced modern medicine significantly. However, the abuse and discharge of antibiotics have led to substantial antibiotic residues in water, posing great harm to natural organisms and humans. To address the problem of antibiotic degradation, this study developed a novel catalytic membrane by depositing Co catalysts onto MXene nanosheets and fabricating the polyethersulfone composite (Co@MXene/PES) using vacuum-assisted self-assembly. The dual role of MXene as both a carrier for Co atoms and an enhancer of interlayer spacing led to improved flux and catalytic degradation capabilities of the membrane. Experimental results confirmed that the Co@MXene/PES membrane effectively degraded antibiotics through peroxymonosulfate activation, achieving up to 95.51% degradation at a cobalt concentration of 0.01 mg/mL. The membrane demonstrated excellent antibacterial properties, minimal flux loss after repeated use, and robust anti-fouling performance, making it a promising solution for efficient antibiotic removal and stable water treatment. [ABSTRACT FROM AUTHOR]

Background Effective management of drug–food interactions is crucial for enhancing antibiotics' efficacy/safety. Adhering to PRISMA guidelines, we conducted a systematic review to assess the impact of dietary interventions on the bioavailability of 15 macrolides and 10 tetracyclines. Methods We included studies examining the influence of food, beverages, antacids, and mineral supplements on the pharmacokinetic parameters of orally administered macrolides and tetracyclines. We searched Medline (via PubMed), Embase and Cochrane Library databases up to December 2022. Risk of bias was assessed using Cochrane and NIH tools. Quantitative analyses were conducted if two or more comparable food-effect studies were available; otherwise, a qualitative summary was provided. Results We included 120 studies from 97 reports. Meta-analyses were conducted for 8 macrolides and 4 tetracyclines, with qualitative synthesis for 10 and 9, respectively. About 64% of the studies were open-label, crossover designs. Our assessment found that 37% of the studies had a high risk of bias, while only 6% had low risk. Food significantly affected 10 of 13 macrolides (77%) and 6 of 7 tetracyclines (86%). High positive effects on bioavailability were seen with extended-release azithromycin and clarithromycin, and erythromycin estolate. High negative impacts were observed with erythromycin propionate and stearate, azithromycin capsules, demeclocycline and omadacycline. Antacids and mineral supplements significantly decreased tetracyclines absorption. Milk and grapefruit juice showed variable impacts on absorption. Discussion Interactions depend on antibiotics' physicochemical characteristics, intervention type, drug formulation and potential patient factors. The quality of evidence was rated low due to outdated studies, methodological diversity and unequal data availability. [ABSTRACT FROM AUTHOR]

While hydrocelectomy is the gold-standard for treating hydroceles, it poses an increased risk to patients and a greater burden to the healthcare system. Sclerotherapy is an alternative treatment for hydroceles that involves injecting a sclerosant into the hydrocele under ultrasound guidance. This literature review aimed to assess the types of sclerosants used and how sclerotherapy compares to hydrocelectomy. A literature search was conducted of MEDLINE and EMBASE using the terms "sclerotherapy" and "hydrocelectomy," which yielded 1058 studies, of which 29 met the inclusion criteria. Only studies published after 2000 were included to ensure the most recent information was reviewed. The results showed hydrocele sclerotherapy is done using a variety of sclerosants. The most used agents are polidocanol, phenol, and STS. Of these, phenol had the highest clinical success rate of 96.5%. There was evidence for the use of atypical agents, such as tetracycline antibiotics, which yielded cure rates up to 93%, and alcohol, which was found to be especially useful for treating multiseptated hydroceles. The results comparing sclerotherapy to hydrocelectomy indicated hydrocelectomy to be a more effective method in completely curing hydroceles. However, this came at the cost of more complications. Additionally, sclerotherapy was found to be more advantageous for secondary outcomes, such as healthcare costs and burden to patients. In conclusion, this review shows that while hydrocelectomy is more effective, sclerotherapy is a valuable alternative for treating hydroceles. Due to the lack of standardization among studies, a definitive conclusion cannot be made regarding which sclerosant is best to use. [ABSTRACT FROM AUTHOR]

CoNOC with CoN (Pd)3 N (Po)1 O1 structure can efficiently catalyse the electro-Fenton reaction to generate –OH to degrade antibiotic pollutants represented by tetracyclines. [Display omitted] • Oxygen-doped Co SACs were prepared using a temperature gradient pyrolysis strategy with nitric acid oxidation method. • DFT calculations explained the excellent catalytic performance was due to the electronic modulation of Co sites by the O doping and N coordination. • TC degradation of 95 % in 120 min and mineralization efficiency of almost 90 % in 180 min were achieved in the electro-Fenton system. • The significant involvement of OH was confirmed, and the degradation pathways of TC have been analyzed and predicted. Electro-Fenton is an effective process for degrading hard-to-degrade organic pollutants, such as tetracycline (TC). However, the degradation efficiency of this process is limited by the activity and stability of the cathode catalyst. Herein, a temperature gradient pyrolysis strategy and oxidation treatment is proposed to modulate the coordination environment to prepare oxygen-doped cobalt monoatomic electrocatalysts (CoNOC). The CoNOC catalysts can achieve the selectivity of 93 % for H 2 O 2 with an electron transfer number close to 2. In the H-cell, the prepared electrocatalysts can achieve more than 100 h of H 2 O 2 production with good stability and the yield of 1.41 mol g catalyst −1 h−1 with an average Faraday efficiency (FE) of more than 88 %. The calculations indicate that the epoxy groups play a crucial role in modulating the oxygen reduction pathway. The O doping and unique N coordination of Co single-atom active sites (CoN (Pd)3 N (Po)1 O1) can effectively weaken the O 2 /OOH* interaction, thereby promoting the production of H 2 O 2. Finally, the electro-Fenton system could achieve a TC degradation rate of 94.9 % for 120 min with a mineralization efficiency of 87.8 % for 180 min, which provides a reliable option for antibiotic treatment. The significant involvement of OH in the electro-Fenton process was confirmed, and the plausible mineralization pathway for TC was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] The activation of peroxymonosulfate (PMS) by carbon-based catalysts is deemed to be a promising method for the degradation of refractory organic contaminants in wastewater. Herein, a Cu-doping strategy in B and N co-doped carbon nanotubes with highly dispersed B O Cu sites and graphite nitrogen were successfully synthesized for activating PMS to degradate tetracycline. The best removal rate of tetracycline within 60 min (97.63 %) was obtained by the 1.5 % Cu-BNC and the degradation rate was increased by 17.9 times. The enhanced catalyst activity was attributed to the promoting the cycle of the Cu(I)/Cu(II) redox pair by the formed B O Cu sites, and the accelerating the electron transfer process by the adsorption of graphitic N for PMS. The non-free radical pathway including 1O 2 and electron transfer played a dominant role in the 1.5 % Cu-BNC/PMS system. The degradation intermediates of TC were identified and three possible degradation pathways were proposed. Further toxicity analysis of the intermediates showed that the 1.5 % Cu-BNC/PMS system had a significant effect on weakening and reducing the biological toxicity and mutagenicity of TC. Moreover, it presented an excellent degradation performance in raw natural water. In general, the proposed regulation of carbon-based catalysts via the coordination-driven effect provides ideas for efficient wastewater treatment. [ABSTRACT FROM AUTHOR]

Inflammatory periodontal diseases associated with the accumulation of dental biofilm, such as gingivitis and periodontitis, are very common and pose clinical problems for clinicians and patients. Gingivitis is a mild form of gum disease and when treated quickly and properly is completely reversible. Periodontitis is an advanced and irreversible disease of the periodontium with periods of exacerbations, progressions and remission. Periodontitis is a chronic inflammatory condition that damages the tissues supporting the tooth in its socket, i.e., the gums, periodontal ligaments, root cementum and bone. Periodontal inflammation is most commonly triggered by bacteria present in excessive accumulations of dental plaque (biofilm) on tooth surfaces. This disease is driven by disproportionate host inflammatory immune responses induced by imbalance in the composition of oral bacteria and changes in their metabolic activities. This microbial dysbiosis favors the establishment of inflammatory conditions and ultimately results in the destruction of tooth-supporting tissues. Apart microbial shift and host inflammatory response, environmental factors and genetics are also important in etiology In addition to oral tissues destruction, periodontal diseases can also result in significant systemic complications. Conventional methods of periodontal disease treatment (improving oral hygiene, dental biofilm control, mechanical plaque removal, using local or systemic antimicrobial agents) are not fully effective. All this prompts the search for new methods of therapy. Advanced periodontitis with multiple abscesses is often treated with antibiotics, such as amoxicillin, tetracycline, doxycycline, minocycline, clindamycin, or combined therapy of amoxicillin with metronidazole. However, due to the growing problem of antibiotic resistance, treatment does not always achieve the desired therapeutic effect. This review summarizes pathogenesis, current approaches in treatment, limitations of therapy and the current state of research on the possibility of application of bacteriophages and predatory bacteria to combat bacteria responsible for periodontitis. We present the current landscape of potential applications for alternative therapies for periodontitis based on phages and bacteria, and highlight the gaps in existing knowledge that need to be addressed before clinical trials utilizing these therapeutic strategies can be seriously considered. [ABSTRACT FROM AUTHOR]

Tetracycline antibiotics are a common type of antibiotics in life. In this research, Fe2+ and Cu2+ was used to modify granular activated carbon, and peroxydisulfate was activated under the synergistic action of electrochemistry (EC/Fe-Cu-GAC/PS). The effects of the initial concentration of tetracycline hydrochloride (TCH), initial pH, current density, and plate spacing on the degradation of TCH were investigated. Experimental results indicated that the removal efficiency of TCH was 87.27% by the EC/Fe-Cu-GAC/PS system. The removal rate of TCH decreased with the increase of initial concentration of TCH. The TCH removal rate is maintained at a high level when pH values range from 3 to 7. Increasing the amount of catalyst and persulfate in a certain range, as well as the magnitude of current density and plate spacing are helpful for TCH removal. When the initial TCH concentration is 20 mg/L, the initial pH value is 5.0, the amount of Fe-Cu-GAC is 2.0 g, the PS concentration is 2 mmol/L, the electrolyte concentration is 25 mmol/L, the current density is 15 mA/cm2, and the plate spacing is 9 cm, the TCH removal effect is the most effective. The free-radical experiment showed that sulfate radicals (SO4•−) played a dominant role under acidic conditions. According to the data analysis, the kinetic model of the EC/Fe-Cu-GAC/PS system was consistent with the first-order reaction kinetics. According to the reaction dynamics, we get the rating of influencing factors that influence the effect of TCH removal. The EC/Fe-Cu-GAC/PS system can effectively degrade tetracycline antibiotics in water. [ABSTRACT FROM AUTHOR]

Most antibiotics contain ionizable groups that undergo acid-base dissociation giving rise to diverse dissociated forms in aquatic systems depending on the pH of the system. In sunlit surface waters, photochemical transformation plays a crucial role in determining the fate of antibiotics. This study presents a comprehensive examination of the photo-transformation degradation kinetics, pathways and photoinduced toxicity of three widely detected tetracyclines (TCs): tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC). Under simulated sunlight (λ > 290 nm), their apparent photolysis followed pseudo-first-order kinetics, with rate constants significantly increasing from H2TCs0 to TCs2−. Through competition kinetic experiments and matrix calculations, it was found that the anions HTCs− or TCs2− (pH ∼ 8–10) were more reactive toward hydroxyl radicals (•OH), while TCs2− (pH ∼ 10) reacted the fastest with singlet oxygen (1O2). Considering the dissociated species, the total environmental photo-transformation half-lives of TCs were determined, revealing a strong dependence on the water pH and seasonal variation in sunlight. Generally, apparent photolysis was the dominant photochemical process, followed by 1O2 and •OH oxidation. Different transformation pathways for the three reactions were determined based on the key photoproducts identified using HPLC-MS/MS. Toxicity tests and ECOSAR software calculations confirmed that the intermediates produced by the •OH and 1O2 photo-oxidation processes were more toxic than the parent compounds. These findings significantly enhance our understanding of the complex photochemical fate and associated risks of TCs in aqueous environments. [ABSTRACT FROM AUTHOR]

Globally, the significant risk to food safety and public health posed by antimicrobial-resistant foodborne Salmonella pathogens is driven by the utilization of in-feed antibiotics, with variations in usage across poultry production systems. The current study investigated the occurrence of virulence, antimicrobial resistant profiles, and biofilm-forming potentials of Salmonella isolates sourced from different chicken types. A total of 75 cloacal faecal samples were collected using sterile swabs from layer, broiler, and indigenous chickens across 15 poultry farms (five farms per chicken type). The samples were analysed for the presence of Salmonella spp. using species-specific PCR analysis. Out of the 150 presumptive isolates, a large proportion (82; 55%) were confirmed as Salmonella species, comprising the serovars S. typhimurium (49%) and S. enteritidis (30%) while 21% were uncategorised. Based on phenotypic antibiotic susceptibility test, the Salmonella isolates were most often resistant to erythromycin (62%), tetracycline (59%), and trimethoprim (32%). The dominant multiple antibiotic resistance phenotypes were SXT-W-TE (16%), E-W-TE (10%), AML-E-TE (10%), E-SXT-W-TE (13%), and AMP-AML-E-SXT-W-TE (10%). Genotypic assessment of antibiotic resistance genes revealed that isolates harboured the ant (52%), tet (A) (46%), sui1 (13%), sui2 (14%), and tet (B) (9%) determinants. Major virulence genes comprising the invasion gene spiC, the SPI-3 encoded protein (misL) that is associated with the establishment of chronic infections and host specificity as well as the SPI-4 encoded orfL that facilitates adhesion, autotransportation and colonisation were detected in 26%, 16%, and 14% of the isolates respectively. There was no significant difference on the proportion of Salmonella species and the occurrence of virulence and antimicrobial resistance determinants among Salmonella isolates obtained from different chicken types. In addition, neither the chicken type nor incubation temperature influenced the potential of the Salmonella isolates to form biofilms, although a large proportion (62%) exhibited weak to strong biofilm-forming potentials. Moderate to high proportions of antimicrobial resistant pathogenic Salmonella serovars were detected in the study but these did not vary with poultry production systems. [ABSTRACT FROM AUTHOR]

Background: Milk is an excellent growth medium for microorganisms due to its nutritive composition. Microorganisms have been implicated in bovine mastitis (BM) in dairy cows as well as causing infections in animals and humans. Despite extensive endeavours to manage BM, this condition continues to persist as the most prevalent and economically burdensome problem affecting dairy cattle on a global scale. Non-aureus staphylococci (NAS) species such as Staphylococcus haemolyticus, S. epidermidis, and S. xylosus are currently the predominant microbiological agents identified as the main cause of subclinical udder infections and are also considered opportunistic pathogens in cases of clinical mastitis in dairy cows. Therefore, it is crucial to elucidate the genetic profile of these species. The primary objective of this study was to characterise three phenotypically determined multidrug-resistant NAS environmental strains (NWU MKU1, NWU MKU2, and NWU MKS3) obtained from dairy cows milk via whole-genome sequencing. Results: The results confirmed that the three isolates were S. haemolyticus with genome sizes of 2.44, 2.56, and 2.56 Mb and a G + C content of 32.8%. The genomes contained an array of antibiotic resistance genes that may potentially confer resistance to a range of antibiotic classes, such as macrolides, fluoroquinolones, aminoglycosides, cephalosporins, tetracyclines, peptides, and phenicol. Furthermore, all the genomes carried virulence genes, which are responsible for several functions, such as adhesion, enzyme and toxin production. The genomes of these organisms contained signatures encoding mobile genetic elements such as prophages and insertion sequences. Conclusion: These findings indicate there is a need for diligent monitoring with improved management practices and quality control strategies on farms to safeguard milk production systems and human health. [ABSTRACT FROM AUTHOR]

In this study, a series of CuMo1−xWxO4 solid solutions (CMWO) were prepared by adjusting the ratio of Mo to W. The morphology, phase, specific surface area, and valence state of the catalysts were characterized using SEM, TEM, XRD, BET, and XPS analysis. The photoelectric characteristics of the CuMo1−xWxO4 solid solution materials were analyzed in detail using Mott–Schottky, EIS, PL, and UV-vis DRS analysis. The experimental results show that the energy band structure of the CMWO solid solutions can be tuned to inhibit the carrier recombination under light excitation, thereby facilitating effective electron–hole pair separation. This significantly enhances the performance of photo-assisted PMS activation for tetracycline (TC) degradation. The solid solution material CMWO-3, with a Mo/W ratio of 7 : 3, achieved a TC degradation rate of 88% at pH 5. After five cycles, the TC degradation rate remained at 86%. Throughout the reaction process, photocatalysis and PMS activation exhibited a synergistic effect, generating reactive species such as SO4˙−, ˙OH, 1O2, and ˙O2−. [ABSTRACT FROM AUTHOR]

A revision on articles concerning thermal analysis of tetracyclines is presented, regarding drug-excipient compatibility, characterization of drug releasing systems, physicochemical behavior of drug-supported systems and degradation of some pharmaceuticals itself. Initially, an overview of information regarding this class of drugs is presented. A bibliographic survey revealed relatively few works on this subject despite the worldwide use and relevance of this class of antibiotics. Here, 37 papers published during the time frame 2000–2022 were classified as above and discussed once they presented thermoanalytical data straightly related to the tetracyclines. From the thermal studies of the drugs, a general decomposition behavior could be identified and it is presented. [ABSTRACT FROM AUTHOR]

Bacillus cereus sensu lato can contaminate food and cause food poisoning by producing toxins such as cereulide, toxin BL, and cytotoxin K. In this study, we retrospectively analyzed B. cereus sensu lato from retail food products and food poisoning cases using PCR methods to determine their virulence profiles. A new toxin profile, encoding all four toxins (hbl, nhe, cytK, ces), was found in 0.4% of isolates. The toxin profiles, classified into A-J, revealed that 91.8% harbored nhe genes, while hbl, cytK, and ces were detected in 43.8%, 46.9%, and 4.2% of isolates, respectively. Whole-genome sequencing (WGS) identified four distinct species within the B. cereus group, with 21 isolates closely related to B. cereus sensu stricte, 25 to B. mosaicus, 2 to B. toyonensis, and 1 to B. mycoides. Three novel sequence types (STs 3297, 3298, 3299) were discovered. Antibiotic resistance genes were common, with 100% of isolates carrying beta-lactam resistance genes. Fosfomycin (80%), vancomycin (8%), streptothricin (6%), tetracycline (4%), and macrolide resistance (2%) genes were also detected. These results highlight the genetic diversity and antibiotic resistance potential of B. cereus sensu lato strains in Polish food products. [ABSTRACT FROM AUTHOR]

The use of antimicrobials is essential for the aquaculture sector; however, their misuse is cause for concern because it could adversely affect the environment and human health. Irresponsible use of antimicrobials can lead to antimicrobial resistance and result in the presence of unwanted residues in aquaculture products. The establishment of maximum residue limits (MRLs) for antimicrobials is of great importance for monitoring their correct use, but the lack of harmonized standards as well as the regulatory gaps for the aquatic products create a challenging situation, as it is reflected in import notifications related to food safety. This paper collects information about current MRLs for antimicrobials in aquatic commodities in the main importing and exporting countries of aquatic products and compares them with each other and with MRLs set by Codex Alimentarius. This analysis highlighted the need for Codex Alimentarius guidance regarding MRLs for nine antimicrobials in aquaculture products (chlortetracycline, doxycycline, enrofloxacin, erythromycin, florfenicol, sulfadimethoxine + ormetoprim, sulfamerazine, tetracycline, and trimethoprim). This paper shows that there is still work to do to implement exhaustive science‐based international standards for residues permitted in aquatic commodities and promote harmonization. [ABSTRACT FROM AUTHOR]

The limited utilization of H2O2 restricts the practical application of heterogeneous Fenton oxidation technology. In this study, the flower-shaped MnFe2O4@MoS2 nanocomposite was prepared by two-step hydrothermal treatment, constructing MnFe2O4@MoS2/H2O2 system for the degradation of tetracycline (TC). Under optimized conditions, MnFe2O4@MoS2/H2O2 system fully degraded 20 mg·L−1 of TC within 60 min, and the corresponding utilization of H2O2 was also as high as 95.7%. Meanwhile, this system not only exhibited excellent cycling stability for the degradation of TC but also had good anti-interference ability against actual water sources, inorganic cations and anions and natural organic compounds. The efficient activation of H2O2 in MnFe2O4@MoS2/H2O2 system mainly relied on the redox cycling of Fe(II)/Fe(III) and Mn(II)/Mn(III) mediated by MoS2; meanwhile, the oxygen vacancies caused by redox cycling also accelerated activation of H2O2, resulting in the production of a large number of active species (·OH, ·O2− and 1O2) for rapid degradation of pollutants. The vulnerable atomic sites of TC were confirmed through theoretical calculation, and four degradation pathways of TC in MnFe2O4@MoS2/H2O2 system were proposed. Finally, the toxicity analysis confirmed that the toxicity of degradation intermediates was developing towards low toxicity. This study provided new insights into the wide application of heterogeneous Fenton systems in wastewater treatment. [ABSTRACT FROM AUTHOR]

Antibiotics are frequently used as growth boosters in animal husbandry. Tetracyclines (TCNs) are among the most widely used antibiotics compared to others, leaving traces in animal‐based foodstuffs like milk and meat. Thus, monitoring of TCNs is paramount, especially in the feedstuff. In the present study, a green method is developed to synthesize magnetic Ag/GO‐Fe3O4 nanocomposites using Azadirachta indica leaf extract. The synthesized adsorbent (Ag/GO‐Fe3O4) was analyzed for the residual extraction of oxytetracycline (OTC) and chlortetracycline (CTC) from the fresh milk samples through the magnetic solid‐phase extraction principle. The extraction procedure involved the deproteinization of milk, spiking with antibiotics, followed by magnetic solid‐phase extraction and quantification of TCNs by HPLC with a UV detector. Different factors that affected the adsorption capacity of the adsorbent for the TCNs like pH, temperature, amount of nanocomposite, and time were studied. The inter‐day and intra‐day precision were calculated for OTC (4% and 6%) and CTC (3% and 4%), respectively. The limit of detection and quantification for OTC was 0.5 and 1.5 μgL−1 and for CTC was 0.2 and 0.6 μgL−1 respectively while the percentage extraction was 94%–96%. [ABSTRACT FROM AUTHOR]

Tetracyclines (TCs) rank second globally in the use of animal infection therapy and animal husbandry as growth promoters among all antibiotics. However, large amounts of TCs residue in food products and more than 75% of TCs are excreted into the environment, causing adverse effects on the ecological system and human health. It has been challenging to simultaneously realize low-cost, rapid, and highly selective detection of TCs. Here, inspired by the fluorogenic reactions between resorcinol and catecholamines, we find the fluorescence quenching ability of tetracycline (TC) and firstly propose a fluorescent "turn-off" detection of TC using dopamine and 4-fluororesorcinol. The optimal reaction condition for the fluorescent assay is investigated and the optimized probe showed a good limit of detection (LOD of 1.7 µM) and a wide linear range (10 µM to 350 µM). Moreover, this fluorescent assay proved to be an effective tool for detecting TC in river, Sprite, and beer samples, which represent the aquatic environments and food and may contain tetracyclines residues. Finally, the high selectivity of the method for TC has been confirmed by eliminating the interference from common substances. The proposed strategy provides a high-efficiency and selective solution for the detection of TCs in environment and food and the application fields of this fluorescent assay could be further expanded in the future. [ABSTRACT FROM AUTHOR]

Recently, the removal of tetracycline, a toxic material, from aquatic medium has been a trending subject of research. Several different technologies including adsorption, biological removal method, solvent extraction, coagulation, chemical reduction, photocatalysis and ion exchange method for removal of tetracyclines from wastewater have been reported. However, photocatalysis of tetracyclines (TC) has gained huge interest because of more efficient mineralization of TC into CO2 and water. Several different nanomaterial based photocatalytic assemblies for the removal of tetracyclines have been widely reported for the removal of tetracyclines which have not been critically reviewed in the literature. This study provides an overview of recent progress of classification, synthesis, characterizations, mechanism of inorganic and metal organic framework nanocatalytic assemblies on photocatalysis of tetracyclines in aquatic medium. Additionally, kinetics and factors affecting the photocatalysis of tetracyclines have been discussed briefly. Future perspectives have also been presented for further advancement in this area. [ABSTRACT FROM AUTHOR]

[Display omitted] • Inverted modulator synthesis of a novel cheap double-ligand Zr-based MOF (MA-MOF). • MA-MOF shows enhanced adsorption and photocatalytic degradation toward tetracycline. • MA-MOF yields holes, ·OH and ·O2− under visible-light for degrading tetracycline. Developing visible-light response photocatalysts with high activity and adsorption alongside sustainability is vitally important to environmental restoration. Here, we fabricated a novel metal organic framework (MOF) with cost-effective double-ligands (fumaric acid and 2-aminoterephthalic acid as ligand precursors, denoted as MA-MOF) via a facile solvothermal method. Specifically, crystalline [Zr 6 O 4 (OH) 4 (fumarate) 6 ] (MOF-801) can be only formed with monocarboxylic acids as modulators. Therefore, in the construction of crystalline double-ligand MA-MOF, the absence of monocarboxylic acid modulators successfully prevents the formation of crystalline MOF-801. Instead, the crystalline double-ligand MA-MOF is formed. Properties of MA-MOFs including the surface area, porosity, charge transfer resistance, and energy level position can be adjusted via altering the ratio of ligands. The optimal sample, MA-MOF2 (prepared with a molar ratio of fumaric acid and 2-aminoterephthalic acid being 2:1), shows a total 94.6% removal of tetracycline via adsorption and photodegradation, far exceeding the corresponding single-ligand counterparts. This work proposes an innovative inverted modulator strategy for constructing double-ligand MOFs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bi 2 O 2 CO 3 /In(OH) 3 photocatalysts were synthesised using a one-pot hydrothermal method. • Bi 2 O 2 CO 3 /In(OH) 3 /PVDF (BON-M) demonstrated effective degradation of tetracycline. • BON-M showed good stability with effective antifouling and self-cleaning properties. • The photocatalyst relies on S-scheme heterojunctions for its effectiveness. • Photogenerated holes play a dominant role in the BON-M system. Bi 2 O 2 CO 3 /In(OH) 3 (BON) photocatalysts were synthesized by a one-pot method and loaded onto polyvinylidene fluoride (PVDF) membranes to obtain a Bi 2 O 2 CO 3 /In(OH) 3 /PVDF (BON-M) catalytic membrane system. The catalytic membranes demonstrated complete degradation of tetracycline within 40 min under visible light. They demonstrated robust photocatalytic activity across a broad pH range (5–11) and in the presence of coexisting ions. The membranes demonstrated excellent self-cleaning performance. Following exposure to light, the irreversible contamination decreased from 27.1% to 4.7% and the membrane's permeability was almost completely restored. Moreover, the charge transfer mechanism at the S-scheme heterojunction interface of BON was demonstrated by Density functional theory and in-situ X-ray Photoelectron Spectroscopy characterisation, and the active sites involved in tetracycline's degradation were identified. Meanwhile, the mechanism of the "anemone effect" of BON-M was demonstrated in conjunction with Electron paramagnetic resonance, and the intrinsic Some factors enhancing the membranes' photocatalytic activity are specified. [ABSTRACT FROM AUTHOR]

The association of amoxicillin and clavulanic acid has shown high efficacy to treat mastitis worldwide, also promoting a shorter milk disposal period compared to other antimicrobials. However, no previous investigations regarding its application to treat mastitis in Brazilian dairy cows were developed. This study evaluated the effectiveness of amoxicillin-clavulanic acid to treat Brazilian dairy cows with mastitis, comparing it with a reference protocol treatment combination of tetracycline, neomycin and bacitracin. Holstein cows (n = 468) from three different dairy herds in Brazil were assigned to two groups: combination of tetracycline, neomycin and bacitracin (n = 178; positive control group) and amoxicillin-clavulanic acid protocol (n = 290). Before the treatment, milk samples were collected and cultivated in chromogenic media. After finishing the antimicrobial treatment (intramammary), milk samples were also collected and cultivated in chromogenic media. Results from microbiological analysis obtained before and after treatment were compared to determine the healing rate. Nine different microbiological agents were identified: eight of environmental origin and one of contagious origin; being eight grampositive and one gram-negative bacteria. TThe positive control group and the treatment group showed similar healing rate (86.5% and 90.3%, respectively; P > 0.05). No differences were found between the groups for the healing rate, when the causing agent was considered. Therefore, it is possible to indicate the amoxicillin-clavulanic acid-based protocol to treat intramammary mastitis in Brazilian dairy cows, achieving great healing rates and providing a substantial reduction in milk disposal. [ABSTRACT FROM AUTHOR]

The worrying issue of antibiotic resistance in pathogenic bacteria is aggravated by the scarcity of novel therapeutic agents. Antibiotic adjuvants offer a promising solution due to their cost-effectiveness and high efficacy in addressing this issue, such as the β-lactamase inhibitor sulbactam (a β-lactam adjuvant) and the dihydrofolate reductase inhibitor trimethoprim (a sulfonamide adjuvant). This study aimed to discover potential adjuvants for tetracyclines from a list of previously approved drugs to restore susceptibility to Escherichia coli carrying the tetA gene. We have screened guanethidine, a compound from the Chinese pharmacopoeia, which effectively potentiates the activity of tetracyclines by reversing resistance in tetA-positive Escherichia coli, enhancing its antibacterial potency, and retarding the development of resistance. Guanethidine functions via the inhibition of the TetA efflux pump, thereby increasing the intracellular concentration of tetracyclines. Our findings suggest that guanethidine holds promise as an antibiotic adjuvant. [ABSTRACT FROM AUTHOR]

The emergence of inactivation enzyme-encoding genes tet(X), blaEBR, and estT challenges the effectiveness of tetracyclines, β-lactams, and macrolides. This study aims to explore the concurrence and polymorphism of their variants in Empedobacter sp. strains from food-producing animals and surrounding environments. A total of eight tet(X) variants, seven blaEBR variants, and seven estT variants were detected in tet(X)-positive Empedobacter sp. strains (6.7%) from chickens, sewage, and soil, including 31 Empedobacter stercoris and 6 novel species of Taxon 1. All of them were resistant to tigecycline, tetracycline, colistin, and ciprofloxacin, and 16.2% were resistant to meropenem, florfenicol, and cefotaxime. The MIC90 of tylosin, tilmicosin, and tildipirosin was 128 mg/L, 16 mg/L, and 8 mg/L, respectively. Cloning expression confirmed that tet(X6) and the novel variants tet(X23), tet(X24), tet(X25), tet(X26), and tet(X26.2) conferred high-level tigecycline resistance, while all of the others exhibited relatively low-level activities or were inactivated. The bacterial relationship was diverse, but the genetic environments of tet(X) and blaEBR were more conserved than estT. An ISCR2-mediated tet(X6) transposition structure, homologous to those of Acinetobacter sp., Proteus sp., and Providencia sp., was also identified in Taxon 1. Therefore, the tet(X)-positive Empedobacter sp. strains may be ignored and pose a serious threat to food safety and public health. [ABSTRACT FROM AUTHOR]

A nondestructive analysis of tetracyclines in drugs by their own fluorescence using a smartphone and a device printed on a 3D printer is proposed. The possibility of using chemometric methods, which reduce the analysis time and visualize the obtained data, is shown. The dataset is processed by principal component analysis (PCA), hierarchical cluster analysis (HCA), partial least squares (PLS) regression, and least squares using the PhotoMetrix PRO® software. The use of chemometric methods of analysis to determine the concentration of the active substance and identify the manufacturer of medicinal products is considered. [ABSTRACT FROM AUTHOR]

Diabetic foot ulcers (DFUs) are a severe complication of poorly controlled Type 2 Diabetes Mellitus (T2DM), significantly increasing the risk of amputation when infected. These infections are often polymicrobial and resistant to antibiotics, making treatment challenging. This study aimed to identify aerobic bacterial isolates in DFU patients and assess their antimicrobial resistance patterns. The study included 100 patients with a mean age of 52.9±11.8 years, of which 81% were male. The average HbA1c was 8.0±1.0%, and the average duration of diabetes was 4.9±4.6 years. Nearly half of the participants (46%) were illiterate. Wagner's grade III ulcers were the most common (37%). Among the 140 isolates, gramnegative bacteria (78.6%) were more common than gram-positive bacteria (21.4%). Monomicrobial infections (57%) were more frequent than polymicrobial ones. The most commonly isolated species were E. coli (17.8%), S. aureus (15%), P. aeruginosa (14.3%), K. pneumoniae (11.4%) and P. rettgerii (7.1%). Effective antibiotics against gram-negative bacteria included netilmicin, imipenem, meropenem and tobramycin, while tetracycline, doxycycline, linezolid and vancomycin were effective against gram-positive bacteria, particularly MRSA. Gentamicin and chloramphenicol were effective against both types. The study found significant associations between polymicrobial infections (p=0.001), amputation (p=0.004), biofilm production (p=0.026) and ulcers lasting over one-month (p=0.049) in patients with multidrug-resistant (MDR) isolates. [ABSTRACT FROM AUTHOR]

• Earthworms and LAB synergistically enhance TC degradation efficiency. • LAB alleviate the biological stress of TC on earthworms. • Various TC doses significantly affect earthworm body bacterial communities. • High TC doses can elevate pathogenic bacteria dominance. Tetracycline is an antibiotic with extensive veterinary use in the livestock industry. However, their widespread application poses risks to soil health as residue in livestock feces, and their removal is crucial for sustainable soil-ecosystem development. Physical and chemical approaches to extract tetracycline may have adverse effects on soil ecosystems, but no studies have thus far examined the potential for biological methods, such as collective degradation action of soil fauna. Thus, this study aimed to investigate the synergistic effects of lactic acid bacteria (LAB) and earthworms (Eisenia fetida) on biodegradation of tetracycline residues in sheep manure. We assessed earthworm biomass, tetracycline residue, and bacterial communities in both earthworm intestines and vermicompost. Earthworm biomass and tetracycline degradation efficiency increased significantly with LAB addition, with a degradation rate of up to 80.16%. This increase may be attributable to LAB acting as electron donors to spur tetracycline degradation. Additionally, we noted that tetracycline presence significantly influenced bacterial communities in earthworm intestines and vermicompost, elevating the abundance of potential pathogenic bacteria (e.g., Flavobacterium , Gammaproteobacteria , and Enterobacteriaceae). This finding suggests that heightened environmental stress from antibiotics could actually facilitate the growth of less prevalent bacteria, including potential pathogens. In conclusion, our study provides evidence supporting the effectiveness of LAB and earthworms in degrading tetracycline residues. In particular, LAB appears to mitigate stress from tetracycline exposure in earthworms, thus increasing their vermicomposting efficacy. Our work has important implications for soil management, with the potential to enhance pollution clean-up rates while minimizing negative side-effects to soil microbial communities. [ABSTRACT FROM AUTHOR]

Photocatalysis is regarded as a potent alternative to conventional treatment methods with low removal efficiency (e.g., activated sludge process) against refractory/recalcitrant antibiotics in wastewater. Here, the potential utility of bismuth oxyiodide (BiOI)-based materials has been evaluated as visible-light–driven photocatalysts (bandgap energy < 2.0 eV) with unique optical structure for the enhanced treatment of tetracyclines (TCs) as a representative antibiotic product. The effects of key modification strategies (e.g., elemental doping and heterojunction formation) on the photocatalytic activity of BiOI-based photocatalysts are assessed against TCs in terms of the key performance metrics such as quantum efficiency (QE) and space-time yield (STY). This review also highlights the challenges and promising opportunities for the photocatalytic application of BiO-based materials against TCs in real effluents. Accordingly, zinc-doped BiOI is recognized to have the maximum efficiency with QE of 2.95 × 10−5 molecules photon−1 and STY of 2.95 × 10−7 molecules photon−1 mg−1. This review is expected to help deepen the exploration path to the construction of efficient BiOI-based systems based on their performance evaluation along with the discussions on their perspectives. [ABSTRACT FROM AUTHOR]

An electrochemical aptasensor was established for the fast and sensitive determination of tetracycline based on the synergistic effect of MoS2-thionine nanocomposite and aptamer. The glassy carbon electrode was coated with MoS2 nanosheets of thionine to immobilize the tetracycline aptamer. In the absence of tetracycline, large quantities of thionin were loaded on the surface of the MoS2 nanosheet to serve as the electrochemical probe. After tetracycline was added to the surface of the electrode, an aptamer analyte complex was produced on the modified electrode. Through intercalation and electrostatic interactions, the complex was substantially adsorbed onto thionine, and the peak currents of the redox signal of thionine decreased. Therefore, the concentration of tetracycline was monitored by the change in signal intensity. Under optimized conditions, the developed electrochemical strategy with MoS2-thionine composite and aptamer exhibited an excellent linear detection range of 1.0 nM–1.0 μΜ and a low detection limit of 0.6 nM with suitable selectivity and stability. Therefore, the fabricated platform offers great potential for food safety, medical detection, and drug analysis. [ABSTRACT FROM AUTHOR]

Well-dispersed MIL-100(Fe) nanoparticles were synthesized under mild conditions and used to construct a photo-Fenton system (VMH system) with the assistance of visible-light irradiation and hydrogen peroxide. In such a VMH system, the MIL-100(Fe) has a high specific surface area and provides numerous Fe3+ active sites, thus accelerating the reaction of Fe3+ with photo-generated electrons under visible-light irradiation and generates Fe2+, and then the acquired Fe2+ can activate H2O2 to generate ⋅OH, accompanying with the oxidation of Fe2+ to Fe3+. Hence, the in-situ recycling of Fe2+/Fe3+ promotes the generation of ·OH, thus making the VMH system exhibits promising photocatalytic activity. The removal rate of ciprofloxacin in the VMH system is as high as 95.2% within 120 min photo-Fenton reaction, which is about 26 times higher than that of the Visible light/MIL-100(Fe) system. Moreover, the VMH system also exhibits strong degradation ability to other typical antibiotics, such as tetracycline, norfloxacin and cephalexin, and maintains high cyclic stability, revealing great practical application potential in the purification of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) constitute an assorted class of multi-dimensional materials that offer the potential to serve as luminescent sensors for the sensitive and selective detection of antibiotics in wastewater. Herein, a new Zn(II)-based MOF with the formula [Zn(PMA)0.5(bbp)·H2O·DMA] (1) (bbp = 3,5-bis(benzoimidazo-1-ly)pyridine; PMA = pyromellitic acid) was synthesized by a solvothermal method and characterized. Crystallographic analysis reveals that MOF 1 possesses a 4,4-connected net with the Schläfli symbol {32·4·52·6}2{32·42·52}. The fabricated MOF exhibited luminescent property and was employed as a luminescent sensor to sensitively and selectively detect tetracycline (TCY) antibiotic amongst thiamphenicol (THI), 2-methyl-4-chlorophenoxyacetic acid (MCPA), tetracycline (TCY), sulfamethoxazole (SMT), thiabendazole (TBZ), tinidazole (TDZ), sulfadiazine (SDZ), chloramphenicol (CAP), metamitron (MMT), and dinotefuran (DTF). Further, restoration of the emissive response of TCY@1 was achieved by adding salicylic acid with a concomitant bathochromic shift in the emissive response. The possible sensing mechanism and restoration of emissive response were assessed with the aid of theoretical calculations. [ABSTRACT FROM AUTHOR]

Background The AnticFast® Beta-lactams & Tetracyclines Combo Test Kit is a qualitative two-step (2 min + 5 min) rapid lateral flow assay to detect β-lactam (penicillins and cefalosporins) and tetracycline antibiotic residues in raw commingled cows' milk. Objective The method performance was evaluated according to Commission Implementing Regulation 2021/808 and Community Reference Laboratories Residues Guidelines for the Validation of Screening Methods for Residues of Veterinary Medicines and submitted for AOAC Performance Tested Methods SM certification. Methods The AnticFast Beta-lactams & Tetracyclines Combo Test Kit was evaluated for detection capability (CCβ), selectivity, false-positive results, repeatability, robustness, suitability for various milk types and milk compositions, milks from various species, and test kit consistency and stability. Samples included milks spiked at concentrations bracketing the EU maximum residue limits (MRLs) for β-lactams and tetracyclines as well as bulk farm and tanker milks. Results The AnticFast Beta-lactams & Tetracyclines Combo Test Kit is specific for the detection of residues of β-lactams and tetracyclines in milk and does not detect residues from other antibiotic families. Interference was seen with clavulanic acid, a β-lactamase inhibitor, which was expected. The test can detect (minimum a 95% detection) all residues of β-lactams (penicillins and cepfalosporins) and tetracyclines (parent drugs and their 4-epimers) present on the EU-MRL list for milk at their respective MRL except for desfuroylceftiofur and cefalexin, with a 95% detection only above the MRL. No false positives were detected in 599 blank samples (out of 305 farm and 301 tanker load samples) tested on both channels. Five real positives were detected and confirmed on the tetracycline channel for the farm milk samples, and two positives were detected and confirmed on the β-lactam channel for the tanker samples. Robustness testing indicated that the detection in high-protein raw cows' milk and heat-treated milk types (UHT, sterilized, and reconstituted milk powder) may be slightly hampered. For substances with a detection capability well below the MRL, this interference does not cause problems since detection at MRL remains guaranteed, but care should be taken for substances with a CCβ at or near their MRL. Diminished sample flow was seen for high-fat raw cows' milk and for all other cows' milk types other than raw milk and blank ewes' milk, so sample flow should always be verified for these milk types. Conclusions Results of this validation show that the AnticFast Beta-lactams & Tetracyclines Combo Test Kit is a reliable test for rapid screening of raw cows' milk for residues of β-lactam and tetracycline antibiotics. Highlights The AnticFast Beta-lactams & Tetracyclines Combo Test Kit is an easy, reliable, robust, and highly specific test for screening of β-lactam (penicillins and cefalosporins) and tetracycline antibiotic residues in milk with incubation at room temperature. In raw cows' milk, all tetracyclines are detected below 10 µg/kg. [ABSTRACT FROM AUTHOR]

Antibiotics are the super drugs that have revolutionized modern medicine by curing many infectious diseases caused by various microbes. They efficiently inhibit the growth and multiplication of the pathogenic microbes without causing adverse effects on the host. However, prescribing suboptimal antibiotic and overuse in agriculture and animal husbandry have led to the emergence of antimicrobial resistance, one of the most serious threats to global health at present. The efficacy of a new antibiotic is high when introduced; however, a small bacterial population attains resistance gradually and eventually survives. Understanding the mode of action of these miracle drugs, as well as their interaction with targets is very complex. However, it is necessary to fulfill the constant need for novel therapeutic alternatives to address the inevitable development of resistance. Therefore, considering the need of the hour, this article has been prepared to discuss the mode of action and recent advancements in the field of antibiotics. Efforts has also been made to highlight the current scenario of antimicrobial resistance and drug repurposing as a fast-track solution to combat the issue. [ABSTRACT FROM AUTHOR]

This study aimed to reveal antibiotic resistance patterns and molecular characterization of quinolone resistance Campylobacter isolates in patients with diarrhea. Campylobacter spp. isolated from 35.33% of the total samples, most of which were from male patients aged 3 months to 10 years. Identifying isolates at the species level made in MALDI-TOF MS, 82.4% were C. jejuni, and 17.6% were C. coli. Respectively 94% (47/50), 58% (29/50), and 2% (1/50) resistance rates were determined for ciprofloxacin, tetracycline, and erythromycin. While C. jejuni isolates were more resistant to ciprofloxacin and tetracycline than C. coli, they showed no resistance to erythromycin. Quinolone resistance determining region (QRDR) were evaluated by mismatch amplification mutation test and all quinolone resistant strains gave positive results. One of the seven silent mutations identified was specific to this study, and two other novel mutations were also identified. [ABSTRACT FROM AUTHOR]

Bacillus anthracis clinical breakpoints, representing a systematic approach to guide clinicians in selecting the most appropriate antimicrobial treatments, are not part of the guidance from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). This is because defined distributions of MIC values and of epidemiological cut-off values (ECOFFs) have been lacking. In this study, a Europe-wide network of laboratories in collaboration with EUCAST, aimed at establishing standardized antimicrobial susceptibility testing methods, wild-type MIC distributions, and ECOFFs for ten therapeutically relevant antimicrobials. About 335 B. anthracis isolates were tested by broth microdilution and disc diffusion methodologies. MIC and inhibition zone diameters were curated according to EUCAST SOP 10.2 and the results were submitted to EUCAST for ECOFFs and clinical breakpoint determination. Broth microdilution and disc diffusion data distributions revealed putative wild-type distributions for the tested agents. For each antimicrobial agent, ECOFFs were defined. Three highly resistant strains with MIC values of 32 mg/L benzylpenicillin were found. MIC values slightly above the defined ECOFFs were observed in a few isolates, indicating the presence of resistance mechanisms to doxycycline, tetracycline, and amoxicillin. B. anthracis antimicrobial susceptibility testing results were used by EUCAST to determine ECOFFs for ten antimicrobial agents. The MIC distributions were used in the process of determining clinical breakpoints. The ECOFFs can be used for the sensitive detection of isolates with resistance mechanisms, and for monitoring resistance development. Genetic changes causing phenotypic shifts in isolates displaying slightly elevated MICs remain to be investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] In this study, metal-free PO 4 3− enriched g-C 3 N 4 /g-C 3 N 4 (PGCN) homojunction alginate 3D beads were developed for in-situ H 2 O 2 production under visible light. Later, the photocatalytic-self-Fenton system was integrated with peroxymonosulfate for tetracycline degradation. Initially, the PO 4 3− enriched g-C 3 N 4 (PCN) and a homojunction composed of PCN and g-C 3 N 4 (GCN) were prepared via the wet-impregnation method. Later, PGCN homojunction was formulated into 3D alginate beads through the blend-crosslinking method. The comprehensive characterization of the homojunction beads affirmed the closer contact between the semiconductors, alteration of the bandgap, faster channelization of electron-hole pairs, and improved separation of charge carriers that attributed to higher catalytic efficacy. The PGCN beads exhibited a maximum H 2 O 2 production of 535 ± 12 µM under visible light irradiation for 60 min. The homojunction hydrogels displayed 99 ± 0.25 % tetracycline degradation in 20 min in the photocatalytic-self-Fenton-PMS system. The experimental studies also claimed a maximum chemical oxygen demand removal of 81 ± 3.6 % in 20 min with maximum reusability of beads up to 20 cycles. The Z-scheme electron migration mechanism is proposed based on the results aided by scavenger and electron spin resonance analysis. Overall, the as-synthesized alginate-supported homojunction-based photocatalytic-self-Fenton-peroxymonosulfate system is highly versatile and reusable for energy and environmental remediation. [ABSTRACT FROM AUTHOR]

Novel NiAl 2 O 4 (NAO)/high entropy alloy (HEA) (Ti), NAO/HEA (Mn) and NAO/HEA (Mo) heterojunction photocatalysts with high photocatalytic activity for the degradation of tetracycline hydrochloride (TC) under simulated sunlight irradiation were synthesized by the polyacrylamide gel method combined with a low temperature sintering technique. The effects of environmental parameters, including drug concentration, catalyst content and pH value, on the photocatalytic activity of NAO/HEA photocatalysts were investigated in detail on the basis of the response surface methodology (RSM) and experimental results. The optimal initial TC concentration, catalyst content, and pH were 100 mg/L, 1 g/L, and 5, respectively. The photocatalytic activity of NAO/HEA photocatalyst (84.6 %) was significantly improved compared to the degradation percentage of HEA (Ti) photocatalyst (36.5 %). The roles of active free radicals including h+, •O 2 −, •OH and oxygen vacancy in photocatalysis were verified using multiple characterization methods. In-depth analysis was conducted on the degradation pathway of TC, the safety of degradation intermediates, and the photocatalytic mechanism of NAO/HEA (Ti) photocatalyst. The Z - scheme heterojunction can significantly improve the transport efficiency of photogenerated carriers and inhibit the recombination rate of electron hole pairs in the system, which provides a new idea for exploring the application of new HEA - based heterojunction photocatalysts in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

In recent years, the widespread application of antibiotics has raised global concerns, posing a severe threat to ecological health. In this study, the occurrence, source, and ecological risks of 39 antibiotics belonging to 5 classes in mangrove sediments from Lianzhou Bay, China, were assessed. The total concentrations of the antibiotics (∑39 antibiotics) ranged from 65.45 to 202.24 ng/g dry weight (dw), with an average of 142.73 ± 36.76 ng/g dw. The concentrations of these five classes of antibiotics were as follows: Sulfonamides (SAs) > Tetracyclines (TCs) > Fluoroquinolones (QUs) > Penicillin (PCs) > Macrolides (MLs). The spatial distribution of antibiotics varied as high tidal zone > middle tidal zone > low tidal zone. The total organic carbon (TOC), pH, nitrate (NO3−-N), and nitrite (NO2−-N) of the sediment significantly influenced the distribution of antibiotics (p < 0.05). A source analysis identified untreated sewage from aquaculture as the primary source of antibiotics in the local mangrove. A risk assessment revealed that ciprofloxacin, norfloxacin, ofloxacin of QUs, and tetracycline of TCs exhibited medium risks to algae in certain sampling sites, while other antibiotics exhibited low or no risks to all organisms. Nevertheless, the total risk of all the detected antibiotics to algae was medium in 95% of the sites. The overall ecological risk level of antibiotics in the middle tidal zone was slightly lower than in the high tidal zone and the lowest in the low tidal zone. In summary, the experimental results provided insights into the fate and transport behaviors of antibiotics in mangrove sediments from Lianzhou Bay. [ABSTRACT FROM AUTHOR]

Abstract Tetracyclines (TCs) rank second globally in the use of animal infection therapy and animal husbandry as growth promoters among all antibiotics. However, large amounts of TCs residue in food products and more than 75% of TCs are excreted into the environment, causing adverse effects on the ecological system and human health. It has been challenging to simultaneously realize low-cost, rapid, and highly selective detection of TCs. Here, inspired by the fluorogenic reactions between resorcinol and catecholamines, we find the fluorescence quenching ability of tetracycline (TC) and firstly propose a fluorescent “turn-off” detection of TC using dopamine and 4-fluororesorcinol. The optimal reaction condition for the fluorescent assay is investigated and the optimized probe showed a good limit of detection (LOD of 1.7 µM) and a wide linear range (10 µM to 350 µM). Moreover, this fluorescent assay proved to be an effective tool for detecting TC in river, Sprite, and beer samples, which represent the aquatic environments and food and may contain tetracyclines residues. Finally, the high selectivity of the method for TC has been confirmed by eliminating the interference from common substances. The proposed strategy provides a high-efficiency and selective solution for the detection of TCs in environment and food and the application fields of this fluorescent assay could be further expanded in the future.

Recent advances in cancer immunotherapy, particularly the success of immune checkpoint inhibitors, have reignited interest in targeted monoclonal antibodies for immunotherapy. Antibody therapies aim to minimize on-target, off-tumor toxicity by targeting antigens overexpressed on tumor cells but not on healthy cells. Despite considerable efforts, some therapeutic antibodies have been linked to dose-limiting side effects. Our hypothesis suggests that the efficacy of IgG leads to a lower target expression threshold for tumor cell killing, contributing to these side effects. Earlier, therapeutic IgG antibodies were reformatted into the IgA isotype. Unlike IgG, which primarily engages Fc gamma receptors (FcγR) to induce antibody-dependent cellular cytotoxicity (ADCC) by NK cells and antibody-dependent cellular phagocytosis (ADCP) by monocytes/macrophages, IgA antibodies activate neutrophils through the Fc alpha receptor I (CD89, FcαRI). In previous studies, it appeared that IgA may require a higher target expression threshold for effective killing, and we aimed to investigate this in our current study. Moreover, we investigated how blocking the myeloid checkpoint CD47/SIRPα axis affect the target expression threshold. Using a tetracycline-inducible expression system, we regulated target expression in different cell lines. Our findings from ADCC assays indicate that IgA-mediated PMN ADCC requires a higher antigen expression level than IgG-mediated PBMC ADCC. Furthermore, blocking CD47 enhanced IgA-mediated ADCC, lowering the antigen threshold. Validated in two in vivo models, our results show that IgA significantly reduces tumor growth in high-antigen-expressing tumors without affecting low-antigen-expressing healthy tissues. This suggests IgA-based immunotherapy could potentially minimize on-target, off-tumor side effects, improving treatment efficacy and patient safety. [ABSTRACT FROM AUTHOR]

In the contemporary context, tetracycline is widely utilized as a prevalent antibiotic in various facets of life. However, the excessive use of antibiotics has caused visible environmental consequences. Henceforth, the scientific community has increasingly focused on developing catalysts that exhibit exceptional efficacy in the proficient degradation of tetracycline. In this study, a novel nanomaterial was developed to encapsulate CdTe quantum dots (QDs) with a SiO2 shell. The distinct synthesis approach generated a composite material that showed heterogeneity and considerably increased the contact area with contaminants. Consequently, the transfer of photoelectron to the SiO2 spheres was significantly improved, leading to a more efficient separation during the catalytic process. The study investigated how different factors, such as the loading of the catalyst, the initial concentration of tetracycline, pH levels, and the wight ratio of CdTe QDs (SiO2 + CdTe QDs) affected the effectiveness of photocatalytic tetracycline degradation. The findings indicated that the optimal degradation efficiency was observed at a catalyst concentration of 0.25 g/L and a solution pH of 9, leading to an impressive degradation rate of 96% within a mere 2 h timeframe. [ABSTRACT FROM AUTHOR]

Background Antimicrobial resistance (AMR) is one of the most pressing global public health challenges; in particular, the rapid dissemination of carbapenem-resistant Enterobacterales (CRE) is emerging as a significant concern worldwide. Flies, serving as carriers of pathogens, pose a potential threat in the transmission of antibiotic-resistant bacteria (ARB) between animals and humans. The aim of this study was to evaluate and reveal the potential risk of AMR spread by flies. Methods A total of 450 flies were collected from four farms, four rural areas, and four urban areas in Dengfeng, Henan, China. To select CRE strains on the surface of flies, three flies sampled from the same geographical location were arbitrarily selected and placed into one tube of brain heart infusion broth (BHI), and the supernatant was screened using CHROMagar[TM] mSuperCARBA culture medium. Different colors and shapes of colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. Antimicrobial susceptibility testing for CRE strains was performed using broth microdilution. All CRE strains were whole-genome sequenced. Short-read sequencing was performed using MGISEQ-2000 and long-read sequencing was conducted using GridION. Results Totally, 150 BHI tubes were screened for CRE strains, and 33 strains were identified as CRE positive. In 24 mSuperCARBA plates, only one species of CRE strain was isolated from each plate. In three plates, two different species of CRE strains were identified in each plate. In one plate, three different species of CRE strains were simultaneously isolated. Carbapenem resistance genes were detected in 81.8% of CRE strains, and bla.sub.NDM-1 was predominant (66.7%). No significant correlations between carbapenem-resistant phenotypes and carbapenem resistance genes were observed. The complete genomes of all 33 strains were obtained. Genome analysis revealed that clonal transmission events may have occurred among different farms and rural areas. Phylogenetic analysis revealed that bla.sub.NDM-1 IncFII plasmids could break bacterial species barrier for cross-host transmission in diverse areas. Conclusions To understand and control the transmission of AMR from the perspective of One Health, it is imperative to enhance surveillance of ARB, antibiotic resistance genes, and antibiotic-resistant plasmids in flies. Keywords: Antimicrobial resistance, Carbapenem-resistant Enterobacterales, Plasmid, Fly, Author(s): Jialiang Xu[sup.1], Jiaqi Liu[sup.1,2], Jiayong Zhao[sup.3], Tian Tian[sup.4], Mengyu Wang[sup.2,5], Gailing Yuan[sup.4], Yao Peng[sup.2], Yuan Zhang[sup.2], Zhe Li[sup.2], Biao Kan[sup.2,5], Zhenpeng Li[sup.2] and Xin Lu[sup.2] Background Antimicrobial resistance (AMR) [...]

Objectives: Antimicrobial resistance (AMR) poses a worldwide challenge, threatening global health. The objective of this research was to determine the 3rd generation cephalosporin resistance (3GCR) proportion in Escherichia (E.) coli isolated from clinical samples of dogs and cats in Germany. Methods: The study utilized result data from antimicrobial susceptibility testing (AST) of isolates obtained from diagnostic samples collected from dogs and cats send in for bacterial examination. Data includes AST results from 3,491 veterinary practices in Germany spanning the years 2019 to 2021, representing 33.1% of practices and clinics nationwide. Out of 175,171 clinical samples, a total of 25,491 E. coli strains (14,6%) were evaluated for their susceptibility to antimicrobials, in particular the 3rd generation cephalosporin cefovecin, but also aminoglycosides (gentamicin, GEN), fluoroquinolones (enrofloxacin, ENR), tetracyclines (doxycycline), phenicols (chloramphenicol), folate pathway inhibitors (sulfamethoxazole + trimethoprim), and nitrofurans (nitrofurantoin). Results: The cefovecin resistance proportion was 11.6% in the study period. Geographical analysis showed local variations in 3GCR in E. coli of ±3%. Regarding all E. coli isolates investigated, resistance proportions were observed as follows: 12% for sulfamethoxazole-trimethoprim, 7% for enrofloxacin, 8% for chloramphenicol and 4% for gentamicin. Notably, 3GCR E. coli showed significantly higher resistance proportions, specifically 30% for sulfamethoxazole-trimethoprim, 28% for chloramphenicol, 18% for enrofloxacin and 14% for gentamicin. Conclusions: This study represents the first of its kind to utilize an extensive dataset encompassing dogs and cats across Germany. Companion animals have close contact to their owners and transmission of 3GCR between them is likely as well as acquisition from other environmental sources. Resistance proportions (6.7%) against the antibiotic ceftazidime as reported by the German AMR surveillance for human medicine were lower than in our veterinary data. Our study provides an overview of the current 3GCR resistance proportion in Germany and demonstrates the importance of integrated AMR monitoring. [ABSTRACT FROM AUTHOR]

Background: Several diagnostic environments in Uganda lack real-time, robust and high-throughput technologies for comprehensive typing of microbes, which is a setback to infectious disease surveillance. This study combined various wet laboratory diagnostics to understand the epidemiology of pathogenic staphylococci isolated from animals in Uganda and the implications for global health security priorities. Methods: A retrospective study was conducted employing records and pathogenic staphylococci (from animals) archived at the Central Diagnostic Laboratory (CDL), Makerere University, Uganda, between January 2012 and December 2019. The bacteria were speciated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and tested for virulence factors [beta lactamases, lecithinase, deoxyribonuclease (DNase), haemolysins] and resistance to ten antimicrobials of clinical and veterinary relevance. Tetracycline and methicillin resistance genes were also tested. Results: The prevalent diseases were mastitis in cattle and skin infections in dogs. Of the 111 staphylococci tested by MALDI-TOF MS, 79 (71.2%) were Staphylococcus aureus, 27 (24.3%) were Staphylococcus pseudintermedius and 5 (4.5%) were Staphylococcus schleiferi. All these strains expressed haemolysins. The prevalence of strains with lecithinase, penicillinase, cephalosporinase and DNase was 35.9% (14/39), 89.7% (35/39), 0.0% (0/39) and 87.2% (34/39), respectively. Staphylococci were primarily resistant to early penicillins (over 80%), tetracycline (57.7%), and chloramphenicol (46.2%). Minimal resistance was noted with cloxacillin (0.0%), ciprofloxacin (9.6%), and cefoxitin (3.8%). The prevalence of multidrug resistance (MDR) was 78.8% for general staphylococci, 82.2% for S. aureus, 73.1% for S. pseudintermedius, and 60.0% for S. schleiferi. Multidrug resistant staphylococci were significantly more prevalent in the cattle isolates than in the dog isolates (P < 0.05). The prevalence of methicillin-resistant staphylococci (MRS) tested by resistance to cefoxitin and mecA carriage was 3.8%. These four strains were all isolated from dog skin infections. The tetK gene was the most predominant (35.4%), followed by tetM (25.0%). Conclusion: In resource-constrained settings, the approach of integrated diagnostics promises sustainable disease surveillance and the addressing of current capacity gaps. The emergence of MRS (zoonotic bacteria) in companion animals creates a likelihood of reduced treatment options for related human infections, a threat to global health. [ABSTRACT FROM AUTHOR]