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This study elucidates the in vivo genetic mechanisms contributing to the emerging resistance to carbapenem in Shewanella algae through a lens of adaptive microbial evolution. Leveraging PacBio amplification-free sequencing, we tracked the evolution of β-lactam resistance in clinical isolates from a persistent S. algae bacteremia case amidst antimicrobial therapy. Our investigation spotlighted a recurrent G547W mutation in the sensor histidine kinase (pdsS), which was associated with the overexpression of an OmpA-like protein (pdsO) within a proteobacteria-specific sortase system. Intriguingly, we observed a recurrent switch between wild-type and G547W alleles, revealing an adaptive expansion and contraction of underlying cell subpopulations in response to β-lactam exposure. Comparative transcriptome analyses further demonstrated the overexpression of genes pivotal for membrane integrity, biofilm formation, immune evasion, and β-lactamase activation in resistant samples. This underscores the pre-existence of resistant cells at minuscule frequencies even without antibiotic pressure, potentially explaining the within-host emergence of resistance during antibiotic treatments. Our findings provide pivotal insights into the dynamic genetic adaptations of S. algae under therapeutic pressures, unmasking intricate resistance mechanisms and highlighting the critical role of subpopulation dynamics in treatment outcomes. [ABSTRACT FROM AUTHOR]

Background: A simple suspension method, where solid formulations are disintegrated and suspended by being soaked in warm water followed by tube administration, is widely used, especially for elderly patients with dysphagia in Japanese clinical settings. However, there is insufficient information on drug stability in the simple co-suspension of multiple formulations especially including acidic or alkaline ones. The influence of occasional prolonged soakage on drug stability is also of concern. In this study, the chemical stability of typical β-lactam antibiotics, amoxicillin, and cefcapene pivoxil hydrochloride, was investigated in simple co-suspensions with magnesium oxide (MgO), which is frequently used as an alkaline laxative for the elderly. Methods: Amoxicillin (capsule) or cefcapene pivoxil hydrochloride (tablet) was placed with or without MgO (tablet) in a centrifuge tube containing warm water (55 °C). The tube was allowed to stand for 10 min or 5 h at room temperature and simple suspensions were prepared. The suspensions were then treated with large amounts of solvents and neutralized using a weakly acidic cation exchange resin. The resulting solutions were analyzed by high-performance liquid chromatography. The degradation products were identified by mass spectrometry and nuclear magnetic resonance spectroscopy. Results: Amoxicillin was found to be partially degraded to amoxicilloic acid and amoxicillin diketopiperazine by the co-suspension with MgO. The degree of degradation increased with the prolonged soaking. The recovery rates of cefcapene pivoxil decreased due to the poor solubility in the co-suspensions with MgO and no degradation product of the drug was observed. Conclusions: Amoxicillin and MgO should be independently suspended because of the chemical instability of amoxicillin. This study has also indicated there is a degradation risk after prolonged soaking. It should be noted that the poor water solubility of cefcapene pivoxil under alkaline conditions may affect the absorption process as well as tube passability. [ABSTRACT FROM AUTHOR]

Background: Novel β-lactam antibiotics as well as other kinds of antibiotics have been used to treat complicated urinary tract infections (cUTIs); however, their efficacy and safety remain controversial. Objective: We conducted a systematic review with meta-analysis to explore the efficacy and safety of novel β-lactam antibiotics versus other antibiotics against cUTIs. Methods: PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched systematically from inception through 15 March 2024 for clinical trials comparing novel β-lactam antibiotics with other antibiotics for treatment of cUTIs. Random-effects models were used to evaluate the impact of treatment on the risk ratio (RR) of clinical response, microbiologic response, adverse effects (AEs), serious adverse effects (SAEs). The quality of evidence was evaluated with the Cochrane Risk of Bias assessment tool. The review was registered in INPLASY (INPLASY202440054). Results: Ten randomized controlled trials involving 5, 925 patients met our inclusion criteria. Our meta-analysis revealed that there was no significant difference in overall clinical response (RR = 1.02), AEs (RR = 1.07), SAEs (RR = 1.20) between novel β-lactam antibiotics groups and other antibiotics groups. However, a significant difference was found in a subgroup of clinical cure rates at the end of treatment between novel β-lactam antibiotics groups and carbapenems groups, with low heterogeneity (RR = 1.02). A significant difference was observed in microbiologic response (RR = 1.11). Subgroup analysis revealed a significant difference in microbiologic response between novel BBL/BLS groups and carbapenems groups (RR = 1.13, I² = 21%, P = 0.005). Differences was observed between novel BBL/BLS groups and piperacillin/tazobactam sodium groups (RR = 1.21, I² = 70%, P = 0.02). Similar results were obtained from subgroup analysis of the difference in microbiologic response between novel β-lactam antibiotics groups and ertapenem groups (RR = 0.92, I² = 0, P = 0.01). Conclusion: Novel β-lactam antibiotics had similar overall clinical cure, AEs, SAE, to other antibiotics in the treatment of cUTIs. However, novel β-lactam antibiotics demonstrated superior clinical cure rates compared to carbapenems in a subgroup analysis, and exhibited better microbiologic response than other antibiotics. [ABSTRACT FROM AUTHOR]

Objective To investigate the clinical features of drug eruptions and the most common causative drugs in inpatients in order to provide a reference for the diagnosis and the treatment of drug eruptions. Methods We retrospectively analyzed the clinical data of inpatients with drug eruptions at the First Affiliated Hospital of Shihezi University from April 2019 to December 2023. Results A total of 89 inpatients with drug eruptions, accounting for 2.90% of the total inpatients at the dermatology department during the same period, included 63 cases(70.79%) of mild drug eruptions(mainly the exanthematous eruptions) and 26 cases (29.21%) of severe drug eruptions (mainly SJS). The most common condition using allergenic drugs was infectious diseases (44 cases, 49.44%), while the majority of drug eruptions(63 cases, 70.79%) were caused by single drug. The top 3 allergenic drugs were antibiotics (33.33%), traditional Chinese medicine (26.98%) and antiepileptics (14.29%). The latency time of mild drug eruptions was shorter than that of severe drug eruptions (4.56 ± 6.14 days vs. 9.35 ± 11.33 days, t = 2.03, P = 0.025). High fever at the early stage was observed in 19.05% of patients with mild drug eruptions and 46.15% of patients with severe drug eruptions. The mean times of hospital stay were comparable between patients with mild drug eruptions and severe drug eruptions (9.02 ± 3.58 days). Systemic glucocorticoids were given to 46(51.69%) patients, including 4 cases of severe drug eruptions, two of each treated together with immunoglobulin and tumor necrosis factor (TNF) -α antagonist, respectively. No deaths were found during the follow-up. Conclusions Exanthematous eruption is the most common type of drug eruptions, while the common allergenic drugs are antibiotics, traditional Chinese medicines and antiepileptics. Large portion of patients with drug eruptions, especially severe cases, experience high fever at the early stage. However, hospitalization time does not diifer between patients with severe and mild drug eruptions. Early administration of sufficient glucocorticoids alone or in combination with other therapies can shorten the hospitalization time for severe drug eruptions. [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]

Abstract β-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of β-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving β-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the β-lactam antibiotic group, exploring the effects of antibiotic use on the newborns’ gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, β-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after β-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced β-lactam-induced alterations. In conclusion, β-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of β-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery.

Piperacillin/tazobactam is a well-known β-lactam antibiotic that has been used in clinical practice since 1993. The review presents the clinical and pharmacological characteristics of piperacillin-tazobactam, the results of clinical studies and determines place of this antibiotic in the treatment of patients with severe urinary tract infections and intraabdominal infections in the light of current data of pathogens’ susceptibility in the Russian Federation and current clinical guidelines.

β-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of β-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving β-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the β-lactam antibiotic group, exploring the effects of antibiotic use on the newborns' gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, β-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after β-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced β-lactam-induced alterations. In conclusion, β-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of β-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery. [ABSTRACT FROM AUTHOR]

Bacillus cereus sensu stricto is a foodborne pathogen that causes food poisoning. Their spore and biofilm-forming abilities persist in various environments and foods. This study investigated the prevalence, virulence, antibiotic resistance, and genetic diversity of B. cereus s. s. strains isolated from various food samples. Of 179 samples, 22.34% were positive for B. cereus s. s., with significantly high detection rates in milk products and raw chicken meat. Forty strains were isolated from positive samples. Matrix-assisted laser desorption ionization/time of flight mass spectrometry analysis revealed nine distinct clusters and multi-locus sequence typing revealed 34 sequence types including 23 novel sequences, demonstrating high genetic diversity among the isolates. PCR analysis revealed that all the strains contained at least one toxin gene, but none contained the cytK gene. Antibiotic resistance tests revealed that all isolates were classified as multidrug-resistant, with high resistance levels, particularly to β-lactam antibiotics and vancomycin, but were susceptible to gentamicin. All isolates showed variations in biofilm formation. This study highlights the significant public health risk due to B. cereus s. s. and underscores the need for stringent monitoring and control measures in food production to manage antimicrobial resistance and ensure food safety. [ABSTRACT FROM AUTHOR]

Nowadays, β-lactam antibiotics are one of the most consumed OTC (over-the-counter) medicines in the world. Its frequent use against several infectious diseases leads to the development of antibiotic resistance. Another unavoidable risk factor of β-lactam antibiotics is environmental toxicity. Numerous terrestrial as well as aquatic species have suffered due to the excessive use of these pharmaceuticals. In this present study, we have performed a toxicity assessment employing a novel in silico technique like quantitative structure–toxicity relationships (QSTRs) to explore toxicity against zebrafish (Danio rerio). We have developed single as well as inter-endpoint QSTR models for the β-lactam compounds to explore important structural attributes responsible for their toxicity, employing median lethal (LC50) and median teratogenic concentration (TC50) as the endpoints. We have shown how an inter-endpoint model can extrapolate unavailable endpoint values with the help of other available endpoint values. To verify the models' robustness, predictivity, and goodness-of-fit, several universally popular metrics for both internal and external validation were extensively employed in model validation (single endpoint models: r2 = 0.631 − 0.75, Q2F1 = 0.607 − 0.684; inter-endpoint models: r2 = 0.768 − 0.84, Q2F1 = 0.678 − 0.76). Again, these models were engaged in the prediction of these two responses for a true external set of β-lactam molecules without response values to prove the reproducibility of these models. [ABSTRACT FROM AUTHOR]

The persistent development of bacterial resistance to β-lactam antibiotics presents a serious risk to public health worldwide. The ability of metallo-β-lactamases (MBLs) to hydrolyze a wide range of β-lactam antibiotics and render them ineffective makes them a difficult challenge. The identification and design of clinically useful inhibitors against MBLs like Verona integron-encoded metallo-β-lactamase-2 (VIM-2) is still challenging. In this study, we examine the inhibitory capacity of peptides against VIM-2 of Pseudomonas aeruginosa. Deriving inspiration from earlier studies on arginine-rich peptides, we hypothesized that lysine repeats with similar nature may show comparable binding with VIM-2.We found that lysine repeats are much more stable than arginine repeats, and show comparable binding with VIM-2. Initially, we designed a library of peptides containing various combinations of lysine and arginine residues, with the sequence length of 30 amino acids. By means of computational modeling, Protein-Peptide docking and molecular dynamics simulations, we evaluated the stability and binding affinity of these peptides in complex with VIM-2. Peptides showing best binding with VIM-2 were subjected to optimization where length was reduced to 12 residues. This optimization was performed to reduce charge and potential toxicity, enhancing the translational prospects of the sequences. We observed that PolyKR (6) was found to be the lead candidate. We demonstrate that incorporation of KR repeats in peptide sequences can be of help in enhancing their binding affinity towards VIM-2. Further, wet-laboratory validation needs to be performed in order to study the interaction of the peptide with the VIM-2 MBL in detail. [ABSTRACT FROM AUTHOR]

Antibiotic treatment of Mycobacterium abscessus disease is toxic and poorly effective and lacks a firm evidence base. Dual β-lactam and β-lactam/β-lactamase inhibitor combinations may be interesting leads to improve treatment outcomes. To summarize the current preclinical studies on dual β-lactam and β-lactam/β-lactamase inhibitor combinations against M. abscessus. We performed a literature search using the National Center for Biotechnology Information's PubMed interface with additional snowball sampling. Select combinations of β-lactam antibiotics, as well as β-lactam/β-lactamase inhibitor combinations show promising in vitro activity and synergy against M. abscessus. β-Lactam antibiotics differ in their ability to reach and interfere with their targets and their resistance to the M. abscessus β-lactamase. The synergy is typically observed for combinations of β-lactam antibiotics or a β-lactam antibiotic with a β-lactamase inhibitor. No additional killing capacity was demonstrated in three-drug combinations of synergistic β-lactam antibiotics and a β-lactamase inhibitor. The efficacy of select dual β-lactam antibiotics and β-lactam/β-lactamase inhibitor combinations is retained in intracellular infection assays and mouse models, but no combination has a complete preclinical portfolio. Future clinical strategies should entail either dual β-lactam or β-lactam/β-lactamase inhibitor combinations. Imipenem-ceftaroline and an all-oral tebipenem-avibactam combination are promising leads but still require a complete preclinical portfolio, target product profiles as well as clinical trial confirmation. [ABSTRACT FROM AUTHOR]

Due to widespread overuse, pharmaceutical compounds, such as antibiotics, are becoming increasingly prevalent in greater concentrations in aquatic ecosystems. In this study, we investigated the capacity of the white-rot fungus, Coriolopsis gallica (a high-laccase-producing fungus), to biodegrade ampicillin under different cultivation conditions. The biodegradation of the antibiotic was confirmed using high-performance liquid chromatography, and its antibacterial activity was evaluated using the bacterial growth inhibition agar well diffusion method, with Escherichia coli as an ampicillin-sensitive test strain. C. gallica successfully eliminated ampicillin (50 mg L−1) after 6 days of incubation in a liquid medium. The best results were achieved with a 9-day-old fungal culture, which treated a high concentration (500 mg L−1) of ampicillin within 3 days. This higher antibiotic removal rate was concomitant with the maximum laccase production in the culture supernatant. Meanwhile, four consecutive doses of 500 mg L−1 of ampicillin were removed by the same fungal culture within 24 days. After that, the fungus failed to remove the antibiotic. The measurement of the ligninolytic enzyme activity showed that C. gallica laccase might participate in the bioremediation of ampicillin. [ABSTRACT FROM AUTHOR]

Monitoring plasma concentrations of β-lactam antibiotics is crucial, particularly in critically ill patients, where variations in concentrations can lead to treatment failure or adverse events. Standardized antimicrobial regimens may not be effective for all patients, especially in special groups with altered physiological parameters. Pharmacokinetic/pharmacodynamic (PK/PD) studies highlight the time-dependent antibacterial activity of these antibiotics, emphasizing the need for personalized dosing. Therapeutic drug monitoring (TDM) is essential, requiring rapid and accurate analytical methods for precise determination of drugs in biological material (typically plasma or serum). This study presents a novel capillary zone electrophoresis–tandem mass spectrometry (CZE-MS/MS) method designed for the simultaneous quantification of five penicillin antibiotics, two cephalosporins, one carbapenem, and two β-lactamase inhibitors in a single run. The method involves a simple sample pretreatment—precipitation with organic solvent—and has a run time of 20 min. Optimization of CZE separation conditions revealed that 20 mM ammonium hydrogen carbonate (NH4HCO3) serves as the optimal background electrolyte (BGE). Positive electrospray ionization (ESI) mode, with isopropyl alcohol (IP)/10 mM ammonium formate water solution (50/50, v/v) as the sheath liquid, was identified as the optimal condition for MS detection. Method validation according to the Food and Drug Administration (FDA) guideline for development of bioanalytical methods demonstrated satisfactory selectivity, linearity, recovery, robustness, and stability. The method's practicality was evaluated using the Blue Applicability Grade Index (BAGI), yielding a score of 77.5. Moreover, the greenness of the proposed method was evaluated by two commonly used metric tools—Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI). The developed CZE-MS/MS method offers a practical and reliable approach for quantifying a broad spectrum of β-lactam antibiotics in plasma. Its ability to simultaneously quantify multiple analytes in a single run, coupled with a straightforward sample pretreatment, positions it as a valuable and prospective tool for TDM in critically ill patients. [ABSTRACT FROM AUTHOR]

Invasive infections caused by Streptococcus pyogfenes (iGAS), commonly known as Group A Streptococcus, represent a significant public health concern due to their potential for rapid progression and life-threatening complications. Epidemiologically, invasive GAS infections exhibit a diverse global distribution, affecting individuals of all ages with varying predisposing factors. The pathogenesis of invasive GAS involves an array of virulence factors that contribute to tissue invasion, immune evasion, and systemic dissemination. In pediatrics, in the last few years, an increase in iGAS infections has been reported worldwide becoming a challenging disease to diagnose and treat promptly. This review highlights the current knowledge on pathogenesis, clinical presentations, and therapeutic approaches for iGAS in children. [ABSTRACT FROM AUTHOR]

The amino acid substitutions in Klebsiella pneumoniae carbapenemase 2 (KPC‐2) that have arisen in the clinic are observed to lead to the development of resistance to ceftazidime‐avibactam, a preferred treatment for KPC bearing Gram‐negative bacteria. Specific substitutions in the omega loop (R164‐D179) result in changes in the structure and function of the enzyme, leading to alterations in substrate specificity, decreased stability, and more recently observed, increased resistance to ceftazidime/avibactam. Using accelerated rare‐event sampling well‐tempered metadynamics simulations, we explored in detail the structural role of R164 and D179 variants that are described to confer ceftazidime/avibactam resistance. The buried conformation of D179 substitutions produce a pronounced structural disorder in the omega loop ‐ more than R164 mutants, where the crystallographic omega loop structure remains mostly intact. Our findings also reveal that the conformation of N170 plays an underappreciated role impacting drug binding and restricting deacylation. The results further support the hypothesis that KPC‐2 D179 variants employ substrate‐assisted catalysis for ceftazidime hydrolysis, involving the ring amine of the aminothiazole group to promote deacylation and catalytic turnover. Moreover, the shift in the WT conformation of N170 contributes to reduced deacylation and an altered spectrum of enzymatic activity. [ABSTRACT FROM AUTHOR]

Ampicillin (AMP) and cefazolin (CZO) are commonly used β-lactam antibiotics which are extensively globally produced. Additionally, AMP and CZO are known to have relatively high ecotoxicity. Notably, the mix of AMP and CZO creates a synergistic effect that is more harmful to the environment, and how exposure to AMP-CZO can induce synergism in algae remains virtually unknown. To yield comprehensive mechanistic insights into chemical toxicity, including dose–response relationships and variations in species sensitivity, the integration of multiple endpoints with de novo transcriptomics analyses were used in this study. We employed Selenastrum capricornutum to investigate its toxicological responses to AMP and CZO at various biological levels, with the aim of elucidating the underlying mechanisms. Our assessment of multiple endpoints revealed a significant growth inhibition in response to AMP at the relevant concentrations. This inhibition was associated with increased levels of reactive oxygen species (ROS) and perturbations in nitrogen metabolism, carbohydrate metabolism, and energy metabolism. Growth inhibition in the presence of CZO and the AMP-CZO combination was linked to reduced viability levels, elevated ROS production, decreased total soluble protein content, inhibited photosynthesis, and disruptions in the key signaling pathways related to starch and sucrose metabolism, ribosome function, amino acid biosynthesis, and the production of secondary metabolites. It was concluded from the physiological level that the synergistic effect of Chlorophyll a (Chla) and Superoxide dismutase (SOD) activity strengthened the growth inhibition of S. capricornutum in the AMP-CZO synergistic group. According to the results of transcriptomic analysis, the simultaneous down-regulation of LHCA4, LHCA1, LHCA5, and sodA destroyed the functions of the photosynthetic system and the antioxidant system, respectively. Such information is invaluable for environmental risk assessments. The results provided critical knowledge for a better understanding of the potential ecological impacts of these antibiotics on non-target organisms. [ABSTRACT FROM AUTHOR]

ABSTRACT Non-heritable, phenotypic drug resistance toward antibiotics challenges antibiotic therapies. Characteristics of such phenotypic resistance have implications for the evolution of heritable resistance. Diverse forms of phenotypic resistance have been described, but phenotypic resistance characteristics remain less explored than genetic resistance. Here, we add novel combinations of single-cell characteristics of phenotypic resistant E. coli cells and compare those to characteristics of susceptible cells of the parental population by exposure to different levels of recurrent ampicillin antibiotic. Contrasting expectations, we did not find commonly described characteristics of phenotypic resistant cells that arrest growth or near growth. We find that under ampicillin exposure, phenotypic resistant cells reduced their growth rate by about 50% compared to growth rates prior to antibiotic exposure. The growth reduction is a delayed alteration to antibiotic exposure, suggesting an induced response and not a stochastic switch or caused by a predetermined state as frequently described. Phenotypic resistant cells exhibiting constant slowed growth survived best under ampicillin exposure and, contrary to expectations, not only fast-growing cells suffered high mortality triggered by ampicillin but also growth-arrested cells. Our findings support diverse modes of phenotypic resistance, and we revealed resistant cell characteristics that have been associated with enhanced genetically fixed resistance evolution, which supports claims of an underappreciated role of phenotypic resistant cells toward genetic resistance evolution. A better understanding of phenotypic resistance will benefit combatting genetic resistance by developing and engulfing effective anti-phenotypic resistance strategies.IMPORTANCEAntibiotic resistance is a major challenge for modern medicine. Aside from genetic resistance to antibiotics, phenotypic resistance that is not heritable might play a crucial role for the evolution of antibiotic resistance. Using a highly controlled microfluidic system, we characterize single cells under recurrent exposure to antibiotics. Fluctuating antibiotic exposure is likely experienced under common antibiotic therapies. These phenotypic resistant cell characteristics differ from previously described phenotypic resistance, highlighting the diversity of modes of resistance. The phenotypic characteristics of resistant cells we identify also imply that such cells might provide a stepping stone toward genetic resistance, thereby causing treatment failure.

Summary: Background: Accurate prediction of the optimal dose for β-lactam antibiotics in neonatal sepsis is challenging. We aimed to evaluate whether a reliable clinical decision support system (CDSS) based on machine learning (ML) can assist clinicians in making optimal dose selections. Methods: Five β-lactam antibiotics (amoxicillin, ceftazidime, cefotaxime, meropenem and latamoxef), commonly used to treat neonatal sepsis, were selected. The CDSS was constructed by incorporating the drug, patient, dosage, pharmacodynamic, and microbiological factors. The CatBoost ML algorithm was used to build the CDSS. Real-world studies were used to evaluate the CDSS performance. Virtual trials were used to compare the CDSS-optimized doses with guideline-recommended doses. Findings: For a specific drug, by entering the patient characteristics and pharmacodynamic (PD) target (50%/70%/100% fraction of time that the free drug concentration is above the minimal inhibitory concentration [fT > MIC]), the CDSS can determine whether the planned dosing regimen will achieve the PD target and suggest an optimal dose. The prediction accuracy of all five drugs was >80.0% in the real-world validation. Compared with the PopPK model, the overall accuracy, precision, recall, and F1-Score improved by 10.7%, 22.1%, 64.2%, and 43.1%, respectively. Using the CDSS-optimized doses, the average probability of target concentration attainment increased by 58.2% compared to the guideline-recommended doses. Interpretation: An ML-based CDSS was successfully constructed to assist clinicians in selecting optimal β-lactam antibiotic doses. Funding: This work was supported by the National Natural Science Foundation of China; Distinguished Young and Middle-aged Scholar of Shandong University; National Key Research and Development Program of China.

Abstract The sequence of a carboxy-terminal of the β-lactam sensor-transducer protein (BlaR-CTD) from Bacillus licheniformis ATCC14580 was extracted from US7745193B2 patent and expressed in E. coli using pColdI vector as a soluble His-tag recombinant protein. In this study, several excipients were used to improve the stability of recombinant BlaR-CTD and obtain the optimal formulation for this protein using response surface methodology (RSM)/ Central Composite Design (CCD). Total protein concentration was measured by UV spectroscopy and the Bradford test. A total of 7 various factors were designed using four different excipients including Glycerol, Sucrose, Triton x-100, and Tween-20, and three different buffers like Tris, Borate, and PBS. By obtaining suitable excipients and buffer i.e. glycerol and sucrose, pH ranging from 7 to 9 were evaluated. The pH 7.62, glycerol 15.35%, and sucrose 152.52 mM were determined as the most suitable for improving the thermal stability of recombinant BlaR-CTD.

Antimicrobial resistance (AMR), also known as antibiotic resistance, is a global health crisis. Many people die from diseases caused by multi-drug resistant pathogens (MDR). Artificial intelligence (AI) deals with applying theory and developing computer systems to conduct tasks usually requiring human intelligence, such as visual perception, speech recognition, decision-making, and translation between languages to solve problems. AI has been successfully used in various fields, from single-cell study to space science. There is huge potential for using AI in medical science, including fighting against MDR to combat AMR. In this review, we have highlighted some of AI's successful uses and potentiality to combat AMR for the betterment of the human race, including the basic principles of AI, available AI resources, use and scope, advantages and limitations. [ J Adv Biotechnol Exp Ther 2023; 6(3.000): 711-727]

The sequence of a carboxy-terminal of the β-lactam sensor-transducer protein (BlaR-CTD) from Bacillus licheniformis ATCC14580 was extracted from US7745193B2 patent and expressed in E. coli using pColdI vector as a soluble His-tag recombinant protein. In this study, several excipients were used to improve the stability of recombinant BlaR-CTD and obtain the optimal formulation for this protein using response surface methodology (RSM)/ Central Composite Design (CCD). Total protein concentration was measured by UV spectroscopy and the Bradford test. A total of 7 various factors were designed using four different excipients including Glycerol, Sucrose, Triton x-100, and Tween-20, and three different buffers like Tris, Borate, and PBS. By obtaining suitable excipients and buffer i.e. glycerol and sucrose, pH ranging from 7 to 9 were evaluated. The pH 7.62, glycerol 15.35%, and sucrose 152.52 mM were determined as the most suitable for improving the thermal stability of recombinant BlaR-CTD. [ABSTRACT FROM AUTHOR]

Acylation of 1-methyl-5-mercapto-1,2,3,4-tetrazolyl-7-aminocephalosporanic acid, which is the β-lactam nucleus of antibiotics such as Cefamandole, Cefazaflur, Cefotetan, and Cefoperazone, has been carried out using immobilized cephalosporin-acid synthetase as a biocatalyst. Methyl esters of D-mandelic acid, 1(H)-tetrazolylacetic acid, cyanomethylthioacetic acid, thienylacetic acid, D-phenylglycine, and D-p-hydroxyphenylglycine were used as acylating agents. Cefamandole and six chimeric compounds composed of the C3-modified β-lactam nucleus and the acyl parts of various known antibiotics were obtained by the method of kinetically controlled synthesis. Potentially, it is possible to test the antimicrobial activity of the synthesized new chimeric cephalosporins under mild conditions without isolation, directly in the aqueous medium of reaction mixtures after biocatalytic synthesis. The high efficiency of cephalosporin-acid synthetase in the acylation of 1-methyl-5-mercapto-1,2,3,4-tetrazolyl-7-aminocephalosporanic acid with methyl esters of 1(H)-tetrazolylacetic acid and cyanomethylthioacetic acid was demonstrated. [ABSTRACT FROM AUTHOR]

Amino ester hydrolases (AEHs) are capable of rapid synthesis of cephalexin but suffer from rapid deactivation even at low temperatures. Previous efforts to engineer AEH have generated several improved variants but have been limited in scope in part due to limitations in activity assay throughput for β-lactam synthesis reactions. Rational design of 'whole variants' was explored to rapidly improve AEH thermostability by mutating between 3–15% of residues. Most variants were found to be inactive due to a mutated calcium binding site, the function of which has not previously been described. Four active variants, all with improved melting temperatures, were characterized in terms of synthesis and hydrolysis activity, melting temperature, and deactivation at 25°C. Two variants were found to have improved total turnover numbers relative to the initial AEH variant; however, a clear tradeoff exists between improved stability and overall activity of each variant. [ABSTRACT FROM AUTHOR]

Background: Antibiotic resistance is a major global threat to the efficacy of bacterial infection treatment. Resistance to beta-lactam antibiotics in bacteria is primarily caused by the production of extended-spectrum-lactamases, with the CTX-M variant, particularly CTX-M-15, being the most common. The need for an effective CTX-M-15 inhibitor is currently pressing. Methods: This study screened a library of natural compounds from the ZINC database against the CTX-M-15 protein using the PyRx 0.8 tool. The SwissADME web platform was used to predict the ADMET properties of the five most promising compounds. Result: The identified hits compounds, ZINC1857626342, ZINC403692, ZINC408773, ZINC57926, and ZINC790938591 exhibited strong binding with CTX-M-15. These compounds interacted with crucial catalytic site residues in the CTX-M-15 protein, particularly Ser70 and Ser130. Notably, the binding energies of these compounds were higher than those of the reference compound avibactam. Furthermore, they exhibited pharmacologically favorable characteristics. Conclusion: These compounds show promise as potential CTX-M-15 inhibitors to combat bacterial resistance. However, more experimental research is needed to optimize these compounds for their role as CTX-M-15 inhibitors. [ABSTRACT FROM AUTHOR]

β-lactam resistance is a serious problem that the hospitals face worldwide; particularly in the developing countries. The widespread of this resistance is attributed to various mechanisms used by the nosocomial bacteria. The aims of this study were to monitor the spread of the β-lactam resistant bacteria in the different provinces of Egypt; to create a biocontrol strategy by producing the β-lactamase inhibitory protein from the Streptomyces bacteria, and to knowing its suitability for the human use. Seventy β-lactam resistant bacterial isolates were sampled randomly from several hospital laboratories across ten governorates of Egypt. The isolates were screened against six different antibiotics; mainly Amoxicillin; Amoxicillin-Clavulanate, Penicillin, Ampicillin-Sulbactam, Cefepime, and Piperacillin-Tazobactam at 250 µg/ ml, and their Minimum inhibitory concentration (MIC) was recorded. The Bn67 isolate was the most promising isolate, which was molecularly identified using 16SrRNA partial sequence as Pseudomonas aeruginosa (LC710315.1). So in order to overcome this bacterial resistance; eighty actinobacteria were isolated from several soil samples collected from Giza governorate, Egypt, and were screened for their effectiveness against Bn67. The actinobacterial isolate (Stn-01) showed the maximum inhibitory efficacy against Bn67 and was identified using 16SrRNA partial sequence as Streptomyces katsurahamanus (LC710314.1). The inhibitor protein (β-LIP-n) was isolated; precipitated, and purified to give 35 kDa with 17 amino acid sequences. The β-LIPn exhibited no cytotoxic potential against the Human Skin Fibroblast (HSF) cell line at 200 µg/ ml. This approach of using the bacterial soil-based inhibitor protein to biocontrol the β-lactam resistant bacteria is considered as novel and as a promising start-up to using the environmental bacteria to overcome this problem of β-lactam resistance.

Objectives On average about 10% of parents report hypersensitivity to at least 1 drug in their children. After diagnosis process a few of these reactions are being confirmed as drug hypersensitivity reactions. The aim of the study was to assess the real-life prevalence of drug hypersensitivity in children based on drug provocation tests. Material and Methods The authors included 113 children, aged 4–18 years, referred to Pediatrics and Allergy Clinic in Łódź, Poland, due to incidence of adverse reaction during treatment. Medical history regarding allergies to drugs was taken in accordance to the form developed by the United States Food and Drug Administration Adverse Event Reporting System. Skin prick tests, intradermal test and drug provocation test were performed in all patients. Results In all 113 patients suspected of drug allergy, after all diagnostic procedures, the authors proved IgE-mediated allergy to β-lactams, nonsteroid anti-inflammatory drugs, local anesthetics in 19 patients (16.8%). Previous history of allergy was a risk factor for drug allergy in studied patients (p = 0.001). The most frequent symptoms of allergy were urticaria and erythematous papular rash. Conclusions Drug allergy is a difficult problem in the practice of a doctor and is difficult to diagnose, especially in the pediatric population. It seems that too often isolated symptoms reported during infection or disease are taken as a symptom of drug allergy, and not as a symptom resulting from the course of the disease. Int J Occup Med Environ Health. 2023;36(5):632–42

Bacillus cereus sensu stricto is a foodborne pathogen that causes food poisoning. Their spore and biofilm-forming abilities persist in various environments and foods. This study investigated the prevalence, virulence, antibiotic resistance, and genetic diversity of B. cereus s. s. strains isolated from various food samples. Of 179 samples, 22.34% were positive for B. cereus s. s., with significantly high detection rates in milk products and raw chicken meat. Forty strains were isolated from positive samples. Matrix-assisted laser desorption ionization/time of flight mass spectrometry analysis revealed nine distinct clusters and multi-locus sequence typing revealed 34 sequence types including 23 novel sequences, demonstrating high genetic diversity among the isolates. PCR analysis revealed that all the strains contained at least one toxin gene, but none contained the cytK gene. Antibiotic resistance tests revealed that all isolates were classified as multidrug-resistant, with high resistance levels, particularly to β-lactam antibiotics and vancomycin, but were susceptible to gentamicin. All isolates showed variations in biofilm formation. This study highlights the significant public health risk due to B. cereus s. s. and underscores the need for stringent monitoring and control measures in food production to manage antimicrobial resistance and ensure food safety.

Multidrug resistance (MDR) is one of the deadliest public health concerns of the 21st century, rendering many powerful antibiotics ineffective. The current study provides important insights into the prevalence and mechanisms of antibiotic resistance in hospital wastewater isolates. In this study, we determined the MDR profile of 68 bacterial isolates collected from five different hospitals in Dhaka, Bangladesh. Of them, 48 bacterial isolates were identified as Enterobacteriaceae. Additionally, we investigated the prevalence and distribution of five beta-lactam resistance genes, as well as quinolone resistance mechanisms among the isolates. The results of this study showed that 87% of the wastewater isolates were resistant to at least three different antibiotic classes, as revealed using the disc diffusion method. Resistance to β-lactams was the most common, with 88.24% of the isolates being resistant, closely followed by macrolides (80.88% resistant). Polymyxin was found to be the most effective against wastewater isolates, with 29.41% resistant isolates. The most common β-lactam resistance genes found in wastewater isolates were blaTEM (76.09%), blaCTX-M1 (71.74%), and blaNDM (67.39%). Two missense mutations in the quinolone resistance-determining region (QRDR) of gyrA (S83L and D87N) and one in both parC (S80I) and parE (S458A) were identified in all isolates, and one in parE (I529L), which had not previously been identified in Bangladesh. These findings suggest that hospital wastewater acts as an important reservoir of antibiotic-resistant bacteria wherein resistance mechanisms to β-lactams and fluoroquinolones are obvious. Our data also emphasize the need for establishing a nationwide surveillance system for antibiotic resistance monitoring to ensure that hospitals sanitize their wastewater before disposal, and regulation to ensure hospital wastewater is kept away from community settings.

Abstract Backgrounds Tigecycline has a broad spectrum of antimicrobial activity and has been approved for the treatment of complicated intra-abdominal infections. However, it is debatable whether tigecycline should be used alone or in combination. This study aimed to investigate whether tigecycline plus β-lactam antibiotics (combination therapy [CT] group) are superior to tigecycline alone (monotherapy [MT] group) in non-critically ill intra-abdominal infection patients after tumor surgery. Methods This was a multicenter, retrospective cohort study. The primary outcome was mortality during the hospital stay. Secondary outcomes were clinical success rate, microbial eradication rate, relapse rate within one week, course of treatment, and adverse effects. Propensity score matching (PSM) was used to adjust the degree of infection before medication between the MT and CT groups. Univariate comparisons were performed using the chi-squared test for qualitative variables and Student’s t-test or the Mann-Whitney U-test for continuous variables, as appropriate. Multivariate logistic regression analysis was performed to examine the relationship between antimicrobial treatments and mortality during hospitalization. The paired samples Wilcoxon test was used to compare the parameters before and after medication. Results In total, 291 patients were included in the final analysis: 128 in MT group and 163 in CT group. Mortality rate was 6.25% in the MT group and 6.13% in the CT group (P = 0.97). Multivariate logistic regression model showed that carbapenem-resistant organisms (OR: 4.35, 95% CI: 2.36 ~ 61.70) and age > 65 (OR: 1.32, 95% CI:1.19 ~ 3.01) were independent risk factors for death. CT group had a shorter defervescence time (P

IntroductionBacterial strains that are resistant to antibiotics may protect not only themselves, but also sensitive bacteria nearby if resistance involves antibiotic degradation. Such cross-protection poses a challenge to effective antibiotic therapy by enhancing the long-term survival of bacterial infections, however, the current understanding is limited.MethodsIn this study, we utilize an automated nanoliter droplet analyzer to study the interactions between Escherichia coli strains expressing a β-lactamase (resistant) and those not expressing it (sensitive) when exposed to the β-lactam antibiotic cefotaxime (CTX), with the aim to define criteria contributing to cross-protection.ResultsWe observed a cross-protection window of CTX concentrations for the sensitive strain, extending up to approximately 100 times its minimal inhibitory concentration (MIC). Through both microscopy and enzyme activity analyses, we demonstrate that bacterial filaments, triggered by antibiotic stress, contribute to cross-protection.DiscussionThe antibiotic concentration window for cross-protection depends on the difference in β-lactamase activity between co-cultured strains: larger differences shift the ‘cross-protection window’ toward higher CTX concentrations. Our findings highlight the dependence of opportunities for cross-protection on the relative resistance levels of the strains involved and suggest a possible specific role for filamentation.

The β-lactamase enzyme is a leading cause of drug resistance developed by bacteria. The combination of β-lactam (BL) antibiotics with an appropriate β-lactamase inhibitor (BLI) is a fundamental approach used to circumvent the problem of β-lactamase mediated resistance. In the present study, non-repeated eight clinical E. coli strains were used in the study. Prior to the screening of synthesized compounds, E. coli strains were phenotypically and genotypically characterized on the basis of MIC and PCR amplification respectively. All newly synthesized thirty-five 1, 2, 3-triazole benzoate derivatives were screened against extended-spectrumtrum β-lactamase class A, class B and class C producing clinical E. coli strains. A zone of inhibition was observed against a class C ESBL trait-bearing isolate with a combination disc containing PB 4 and Cefoxitin indicated the inhibitory activity of PB 4. Similarly, inhibitions by PB 6, PB 7, PB 8, PB 9, PB 15, PB 30 and Cefotaxime against class-A ESBL trait-bearing isolates are indicative of class A ESBL inhibitor capacity of these compounds. In conclusion, cefoxitin in combination with PB 4 and cefotaxime in combination PB 6, PB 7, PB 8, PB 9, PB 15, and PB 30 overcomes the class C and class A β-lactamase enzymatic activity respectively in E. coli strains.

Methicillin-resistant Staphylococcus aureus (MRSA), a global health concern, has prompted research into antibiotic adjuvants as a potential solution. Although our group previously reported the enhancing effects of gallic acid (GA) and methyl gallate (MG) on penicillin G activity against MRSA, the synergistic potential with other β-lactam antibiotics and the underlying mechanism have not been fully explored. Therefore, this study primarily aimed to investigate the antibacterial synergism with β-lactam antibiotics through disc diffusion, checkerboard, and time–kill assays. The β-lactamase inhibition was also examined through both molecular modeling and in vitro experiments. Additionally, bacterial morphology changes were studied using a scanning electron microscopy (SEM). The results revealed that both GA and MG exhibited anti-MRSA activity and showed indifferent effects when combined with β-lactam antibiotics against methicillin susceptible S. aureus (MSSA). Interestingly, MG demonstrated synergism with only the β-lactamase-unstable antibiotics against MRSA with the lowest fractional inhibitory concentration (FIC) indexes of ≤3.75. However, GA and MG exhibited weak β-lactamase inhibition. Furthermore, GA, MG, and the combination with ampicillin induced the morphological changes in MRSA, suggesting a possible mechanism affecting the cell membrane. These findings suggest that MG could potentially serve as an adjunct to β-lactam antibiotics to combat MRSA infections. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae is a major human pathogen and rising resistance to β-lactam antibiotics, such as penicillin, is a significant threat to global public health. Mutations occurring in the penicillin-binding proteins (PBPs) can confer high-level penicillin resistance but other poorly understood genetic factors are also important. Here, we combined strictly controlled laboratory experiments and population analyses to identify a new penicillin resistance pathway that is independent of PBP modification. Initial laboratory selection experiments identified high-frequency pde1 mutations conferring S. pneumoniae penicillin resistance. The importance of variation at the pde1 locus was confirmed in natural and clinical populations in an analysis of >7,200 S. pneumoniae genomes. The pde1 mutations identified by these approaches reduce the hydrolytic activity of the Pde1 enzyme in bacterial cells and thereby elevate levels of cyclic-di-adenosine monophosphate and penicillin resistance. Our results reveal rapid de novo loss of function mutations in pde1 as an evolutionary gateway conferring low-level penicillin resistance. This relatively simple genomic change allows cells to persist in populations on an adaptive evolutionary pathway to acquire further genetic changes and high-level penicillin resistance. [ABSTRACT FROM AUTHOR]

To investigate the death cause of a forest musk deer (Moschus berezovskii), samples of the dead forest musk deer were collected aseptically for bacterial isolation and drug resistance analysis. The isolate was identified by bacterial isolation and purification, biochemical identification,16S rDNA gene sequencing, disc diffusion test and antibiotic resistance genes detection. The results showed that Escherichia fergusonii was isolated from the samples of the dead deer. Drug sensitive test confirmed that the isolate was resistant to cefotaxime, cephalothin and penicillin, while it was sensitive to aminoglycosides, quinolones and aminopenicillins. The analysis of resistance genes detection showed that bla-OXA1/4/30, blaCTX-M and bla-SHV were all detected. In conclusion, this study provides a reference to prevention and treatment of pathogenic E. fergusonii in the cultivation of forest musk deer. [ABSTRACT FROM AUTHOR]

Objectives: On average about 10% of parents report hypersensitivity to at least 1 drug in their children. After diagnosis process a few of these reactions are being confirmed as drug hypersensitivity reactions. The aim of the study was to assess the real-life prevalence of drug hypersensitivity in children based on drug provocation tests. Material and Methods: The authors included 113 children, aged 4-18 years, referred to Pediatrics and Allergy Clinic in Łódź, Poland, due to incidence of adverse reaction during treatment. Medical history regarding allergies to drugs was taken in accordance to the form developed by the United States Food and Drug Administration Adverse Event Reporting System. Skin prick tests, intradermal test and drug provocation test were performed in all patients. Results: In all 113 patients suspected of drug allergy, after all diagnostic procedures, the authors proved IgE-mediated allergy to ß-lactams, nonsteroid anti-inflammatory drugs, local anesthetics in 19 patients (16.8%). Previous history of allergy was a risk factor for drug allergy in studied patients (p = 0.001). The most frequent symptoms of allergy were urticaria and erythematous papular rash. Conclusions: Drug allergy is a difficult problem in the practice of a doctor and is difficult to diagnose, especially in the pediatric population. It seems that too often isolated symptoms reported during infection or disease are taken as a symptom of drug allergy, and not as a symptom resulting from the course of the disease. [ABSTRACT FROM AUTHOR]

The optimisation of the use of β-lactam antibiotics (BLA) via prolonged infusions in life-threatening complications such as febrile neutropenia (FN) is still controversial. This systematic review and meta-analysis aim to evaluate the efficacy of this strategy in onco-haematological patients with FN. A systematic search was performed of PubMed, Web of Science, Cochrane, EMBASE, World Health Organization, and ClinicalTrials.gov, from database inception until December 2022. The search included randomised controlled trials (RCTs) and observational studies that compared prolonged vs short-term infusions of the same BLA. The primary outcome was all-cause mortality. Secondary outcomes were defervescence, requirement of vasoactive drugs, length of hospital stay and adverse events. Pooled risk ratios were calculated using random effects models. Five studies were included, comprising 691 episodes of FN, mainly in haematological patients. Prolonged infusion was not associated with a reduction in all-cause mortality (pRR 0.83; 95% confidence interval 0.47–1.48). Nor differences were found in secondary outcomes. The limited data available did not show significant differences in terms of all-cause mortality or significant secondary outcomes in patients with FN receiving BLA in prolonged vs. short-term infusion. High-quality RCTs are needed to determine whether there are subgroups of FN patients who would benefit from prolonged BLA infusion. [ABSTRACT FROM AUTHOR]

Catheter-associated urinary tract infections (CAUTI) are one of the most common nosocomial diseases accounting for up to about 23% of healthcare-associated infections. High antibiotic resistance of biofilm-associated bacteria is a serious limiting factor in the treatment of patients. Therefore, the investigations of bacterial biofilms and their regulation can play a pivotal role in the development of new approaches to treating infections. P. aeruginosa is a key bacterium responsible for most urinary tract infections. In this study, urinary catheter–associated P. aeruginosa strains were isolated and their antibiotic resistance was studied. Polymicrobial biofilms were found on the urinary catheter surfaces derived from patients with different urinary tract diseases. Three strains of Pseudomonas aeruginosa isolated from the catheter-associated biofilms were resistant to meropenem. The resistance to carbapenemss of P. aeruginosa strains 96,347 and 96,349 was observed to be mediated by VIM-type metallo-β-lactamase gene expression. [ABSTRACT FROM AUTHOR]

Due to widespread overuse, pharmaceutical compounds, such as antibiotics, are becoming increasingly prevalent in greater concentrations in aquatic ecosystems. In this study, we investigated the capacity of the white-rot fungus, Coriolopsis gallica (a high-laccase-producing fungus), to biodegrade ampicillin under different cultivation conditions. The biodegradation of the antibiotic was confirmed using high-performance liquid chromatography, and its antibacterial activity was evaluated using the bacterial growth inhibition agar well diffusion method, with Escherichia coli as an ampicillin-sensitive test strain. C. gallica successfully eliminated ampicillin (50 mg L−1) after 6 days of incubation in a liquid medium. The best results were achieved with a 9-day-old fungal culture, which treated a high concentration (500 mg L−1) of ampicillin within 3 days. This higher antibiotic removal rate was concomitant with the maximum laccase production in the culture supernatant. Meanwhile, four consecutive doses of 500 mg L−1 of ampicillin were removed by the same fungal culture within 24 days. After that, the fungus failed to remove the antibiotic. The measurement of the ligninolytic enzyme activity showed that C. gallica laccase might participate in the bioremediation of ampicillin.

Monitoring plasma concentrations of β-lactam antibiotics is crucial, particularly in critically ill patients, where variations in concentrations can lead to treatment failure or adverse events. Standardized antimicrobial regimens may not be effective for all patients, especially in special groups with altered physiological parameters. Pharmacokinetic/pharmacodynamic (PK/PD) studies highlight the time-dependent antibacterial activity of these antibiotics, emphasizing the need for personalized dosing. Therapeutic drug monitoring (TDM) is essential, requiring rapid and accurate analytical methods for precise determination of drugs in biological material (typically plasma or serum). This study presents a novel capillary zone electrophoresis–tandem mass spectrometry (CZE-MS/MS) method designed for the simultaneous quantification of five penicillin antibiotics, two cephalosporins, one carbapenem, and two β-lactamase inhibitors in a single run. The method involves a simple sample pretreatment—precipitation with organic solvent—and has a run time of 20 min. Optimization of CZE separation conditions revealed that 20 mM ammonium hydrogen carbonate (NH4HCO3) serves as the optimal background electrolyte (BGE). Positive electrospray ionization (ESI) mode, with isopropyl alcohol (IP)/10 mM ammonium formate water solution (50/50, v/v) as the sheath liquid, was identified as the optimal condition for MS detection. Method validation according to the Food and Drug Administration (FDA) guideline for development of bioanalytical methods demonstrated satisfactory selectivity, linearity, recovery, robustness, and stability. The method’s practicality was evaluated using the Blue Applicability Grade Index (BAGI), yielding a score of 77.5. Moreover, the greenness of the proposed method was evaluated by two commonly used metric tools—Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI). The developed CZE-MS/MS method offers a practical and reliable approach for quantifying a broad spectrum of β-lactam antibiotics in plasma. Its ability to simultaneously quantify multiple analytes in a single run, coupled with a straightforward sample pretreatment, positions it as a valuable and prospective tool for TDM in critically ill patients.

Invasive infections caused by Streptococcus pyogfenes (iGAS), commonly known as Group A Streptococcus, represent a significant public health concern due to their potential for rapid progression and life-threatening complications. Epidemiologically, invasive GAS infections exhibit a diverse global distribution, affecting individuals of all ages with varying predisposing factors. The pathogenesis of invasive GAS involves an array of virulence factors that contribute to tissue invasion, immune evasion, and systemic dissemination. In pediatrics, in the last few years, an increase in iGAS infections has been reported worldwide becoming a challenging disease to diagnose and treat promptly. This review highlights the current knowledge on pathogenesis, clinical presentations, and therapeutic approaches for iGAS in children.

Ampicillin (AMP) and cefazolin (CZO) are commonly used β-lactam antibiotics which are extensively globally produced. Additionally, AMP and CZO are known to have relatively high ecotoxicity. Notably, the mix of AMP and CZO creates a synergistic effect that is more harmful to the environment, and how exposure to AMP-CZO can induce synergism in algae remains virtually unknown. To yield comprehensive mechanistic insights into chemical toxicity, including dose–response relationships and variations in species sensitivity, the integration of multiple endpoints with de novo transcriptomics analyses were used in this study. We employed Selenastrum capricornutum to investigate its toxicological responses to AMP and CZO at various biological levels, with the aim of elucidating the underlying mechanisms. Our assessment of multiple endpoints revealed a significant growth inhibition in response to AMP at the relevant concentrations. This inhibition was associated with increased levels of reactive oxygen species (ROS) and perturbations in nitrogen metabolism, carbohydrate metabolism, and energy metabolism. Growth inhibition in the presence of CZO and the AMP-CZO combination was linked to reduced viability levels, elevated ROS production, decreased total soluble protein content, inhibited photosynthesis, and disruptions in the key signaling pathways related to starch and sucrose metabolism, ribosome function, amino acid biosynthesis, and the production of secondary metabolites. It was concluded from the physiological level that the synergistic effect of Chlorophyll a (Chla) and Superoxide dismutase (SOD) activity strengthened the growth inhibition of S. capricornutum in the AMP-CZO synergistic group. According to the results of transcriptomic analysis, the simultaneous down-regulation of LHCA4, LHCA1, LHCA5, and sodA destroyed the functions of the photosynthetic system and the antioxidant system, respectively. Such information is invaluable for environmental risk assessments. The results provided critical knowledge for a better understanding of the potential ecological impacts of these antibiotics on non-target organisms.

ABSTRACT Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen that can cause a variety of acute and chronic infections. The bacterium is highly resistant to numerous antibiotics. Murepavadin is a peptidomimetic antibiotic that blocks the function of P. aeruginosa lipopolysaccharide (LPS) transport protein D (LptD), thus inhibiting the insertion of LPS into the outer membrane. In this study, we demonstrated that sublethal concentrations of murepavadin enhance the bacterial outer membrane permeability. Proteomic analyses revealed the alteration of protein composition in bacterial inner and outer membranes following murepavadin treatment. The antisigma factor MucA was upregulated by murepavadin. In addition, the expression of the sigma E factor gene algU and the alginate synthesis gene algD was induced by murepavadin. Deletion of the algU gene reduces bacterial survival following murepavadin treatment, indicating a role of the envelope stress response in bacterial tolerance. We further demonstrated that murepavadin enhances the bactericidal activities of β-lactam antibiotics by promoting drug influx across the outer membrane. In a mouse model of acute pneumonia, the murepavadin–ceftazidime/avibactam combination showed synergistic therapeutic effect against P. aeruginosa infection. In addition, the combination of murepavadin with ceftazidime/avibactam slowed down the resistance development. In conclusion, our results reveal the response mechanism of P. aeruginosa to murepavadin and provide a promising antibiotic combination for the treatment of P. aeruginosa infections. Importance The ever increasing resistance of bacteria to antibiotics poses a serious threat to global public health. Novel antibiotics and treatment strategies are urgently needed. Murepavadin is a novel antibiotic that blocks the assembly of lipopolysaccharide (LPS) into the Pseudomonas aeruginosa outer membrane by inhibiting LPS transport protein D (LptD). Here, we demonstrated that murepavadin impairs bacterial outer membrane integrity, which induces the envelope stress response. We further found that the impaired outer membrane integrity increases the influx of β-lactam antibiotics, resulting in enhanced bactericidal effects. In addition, the combination of murepavadin and a β-lactam/β-lactamase inhibitor mixture (ceftazidime/avibactam) slowed down the resistance development of P. aeruginosa. Overall, this study demonstrates the bacterial response to murepavadin and provides a new combination strategy for effective treatment.

This review considers the contribution of works carried out at the scientific school of Ilya Vasilievich Berezin to research on the kinetics and thermodynamics of penicillin acylase-catalyzed reactions. Methods for determining the activity of penicillin acylases, the reversibility of the enzymatic hydrolysis of a number of penicillins, cephalosporins, and related compounds, the influence of the β-lactam ring on the thermodynamics of the synthesis of new penicillins and cephalosporins by direct condensation as well as by acyl transfer, the issues of optimizing the conditions for enzymatic acyl transfer, and the use of supersaturated reagent solutions are discussed. The role of chromogenic substrates in the study of penicillin acylase, the possibility of using the methods of titration of active sites of the enzyme and the creation of "smart" biocatalysts based on penicillin acylase due to the formation of conjugates with stimulus-sensitive polymers are considered. [ABSTRACT FROM AUTHOR]

We developed selective and relatively low-cost metal-chelated nanoparticle systems for the removal of the penicillin G (Pen G) antibiotic, presented for the first time in the literature. In the nanosystem, poly(glycidyl methacrylate) nanoparticles were synthesized by a surfactant-free emulsion polymerization method and covalently bound with a tridentate-chelating ligand, iminodiacetic acid, based on the immobilized metal chelate affinity technique. It was modified with Cu2+, a chelating metal, to make Pen G specific. Metal-chelated nanoparticles were characterized by Fourier-transform infrared spectroscopy, energy dispersive spectrometry, zeta dimensional analysis, and scanning electron microscopy technology. Optimization studies of the Pen G removal were conducted. As a result of this study, Pen G removal with the p(GMA)-IDA-Cu2+ nanoparticle reached its maximum adsorption capacity of 633.92 mg/g in the short time of 15 min. The Pen G adsorption of p(GMA)-IDA-Cu2+ was three times more than that of the p(GMA) nanoparticles and two times more than that of the ampicillin adsorption. In addition, there was no significant decrease in the adsorption capacity of Pen G resulting from the repeated adsorption–desorption process of metal-chelated nanoparticles over five cycles. The metal-chelated nanoparticle had an 84.5% ability to regain its ability to regenerate the product with its regeneration capability, making the widespread use of the system very convenient in terms of reducing cost, an important factor in removal processes. [ABSTRACT FROM AUTHOR]

The newly semi-synthetic β -lactam antibiotics play critical roles in prevention and treatment of β -lactam antibiotic-resistant bacteria. Acetyl xylan esterases belong to carbohydrate esterase 7 family can specifically hydrolyze 7-aminocephalosporanic acid (7-ACA) to produce deacetyl-7-aminocephalosporanic acid (D-7ACA) which is one of the most important starting materials to synthesize newly semi-synthetic β -lactam antibiotics. Here, an effective acetyl xylan esterase, ThAXE, from Thermobifida halotolerans YIM 90462 T, was firstly identified and characterized. ThAXE exhibited its highest catalytic activity against p -nitrophenyl acetate (p -NPC 2) at pH 8.5 and 50 °C, with K m and K cat / K m were 1.0 ± 0.1 mM and 2262.9 mM−1 s−1, respectively. Additionally, ThAXE can hydrolyze the acetyl group of 7-ACA at its C3' position with the specific activity of 7.4 U mg−1. Furthermore, molecular docking combined with site-directed mutagenesis validation demonstrated that the pocket of catalytic residues Ser186, Asp272, and His301 could accommodate p -NPC 2 and 7-ACA ligands. This is the first report of a novel acetyl xylan esterase from T. halotolerans that has considerable potential biotechnological values. [Display omitted] • A novel thermostable and halotolerant acetyl xylan esterase (ThAXE) was characterized. • Residues Ser186-Asp272-His301 are critical for ThAXE activity. • ThAXE remains stable in 50 mM Tris–HCl buffer (pH 8.5) containing NaCl at a concentration of 20% (w/v). • ThAXE can transform 7-aminocephalosporanic acid (7-ACA) to deacetyl-7ACA. [ABSTRACT FROM AUTHOR]

Background: Tigecycline and cefoperazone/sulbactam can cause coagulation disorders; tigecycline may also lead to hypofibrinogenemia, raising safety concerns. This study aimed to investigate whether tigecycline plus cefoperazone/sulbactam increases the risk of bleeding compared with other tigecycline-based combination therapies and identify risk factors for tigecycline-associated hypofibrinogenemia. Methods: In this multi-method, multicenter, retrospective study, coagulation and other baseline variables were compared using a cohort study, and risk factors for hypofibrinogenemia using a case-control study. Results: The 451 enrolled participants were divided into three group: tigecycline plus cefoperazone/sulbactam (Group A, 193 patients), tigecycline plus carbapenems (Group B, 200 patients) and tigecycline plus β-lactams without N-methylthio-tetrazole (NMTT) side chains (Group C, 58 patients). Activated partial thromboplastin time and prothrombin time were prolonged, and fibrinogen declined for all patients after tigecycline-based medication (all p < 0.05). Prothrombin time in Group B was significantly longer than in other groups (p < 0.05), but there were no significant differences in bleeding events between the three groups (p = 0.845). Age greater than 80 years (OR: 2.85, 95% CI: 1.07–7.60), treatment duration (OR: 1.29, 95% CI: 1.19–1.41), daily dose (OR: 2.6, 95% CI: 1.29–5.25), total bilirubin (OR: 1.01, 95% CI: 1.01–1.02) and basal fibrinogen (OR: 1.32, 95% CI: 1.14–1.63) were independent risk factors of hypofibrinogenemia. The optimal cut-off for treatment course was 6 days for high-dose and 11 days for lowdose. Conclusion: Tigecycline plus cefoperazone/sulbactam did not increase the risk of bleeding compared with tigecycline plus carbapenem, or tigecycline plus β-lactam antibiotics without NMTT-side-chains. Coagulation function should be closely monitored in patients receiving tigecycline treatment. [ABSTRACT FROM AUTHOR]

Objective To analyze the influence of β-lactam antibiotics on RBC aging and clearance by detecting various indicators of aging and clearance on RBCs, as well as the differences in phagocytosis for erythrocytes before and after drugs treated in vitro. Methods RBCs were treated by β-lactam antibiotics, including Penicillin, Cefepime, Cefoperazone and Ceftazidime, and the changing of phosphatidylserine (PS) and clearance related CD markers, including CD35, CD47, CD55 and CD59 on the surface of the RBCs, were detected by flow cytometry at 0h and 24h after drugs treatment. The proportion of acanthocytes by microscope also at 0h and 24h after drugs treatment was calculated. The phagocytosis of drug-treated RBC was detected by monocyte monolayer assay (MMA). Untreated RBCs were incubated in PBS by the same condition as a negative control.The influence of β-lactam antibiotics on RBC aging and clearance by all the results above was studied. Results Compare to the untreated RBCs, the drug treated RBCs showed a higher PS level on the cell surface. The results showed by percentage as following(0 h vs 24 h): Penicillin 9.42% vs 93.30%, Cefepime 3.88% vs 57.27%, Cefoperazone 4.71% vs 75.75% and Ceftazidime 3.05% vs 43.19%. The acanthocytes ratio was as following(0 h vs 24 h): Penicillin 7.33% vs 86%, Cefepime 2.67% vs 52.67%, Cefoperazone 3.33% vs 67.67% and Ceftazidime 3.33% vs 90.67%. On the opposite, the clearance related CD markers, showed an obviously lower level after drugs treated(0 h vs 24 h): CD35: Penicillin 7.36% vs 11.87%, Cefepime 0.14% vs 28.51%, Cefoperazone 11.85% vs 21.55% and Ceftazidime 7.63% vs 8.73%; CD47: Penicillin 1.22% vs 9.13%, Cefepime 1.80% vs 0.86%, Cefoperazone 0.08% vs 6.85% and Ceftazidime 1.54% vs 5.50%; CD55: Penicillin 14.46% vs 44.31%, Cefepime 17.27% vs 38.41%, Cefoperazone 19.28% vs 33.28% and Ceftazidime 14.62% vs 34.13%; CD59: Penicillin 4.71% vs 20.56%, Cefepime 4.03% vs 7.60%, Cefoperazone 5.91% vs 22.38% and Ceftazidime 5.93% vs 30.89%. Drug-treated RBCs attached more to monocytes than untreated RBCs. Conclusion The β-lactam antibiotics could induce the changing of PS and the clearance of related CD markers on surface of RBCs. They also could lead acanthocytes and make the RBCs more susceptible to phagocytosis by monocytes. The β-lactam antibiotics could promote the RBCs aging and clearance, which might deteriorate the DIIHA.