The global microbial resistance is a serious threat to human health, and multitargeting compounds are considered to be promising to combat microbial resistance. In this work, a series of new thiazolylquinolones with multitargeting antimicrobial potential were developed through multi-step reactions using triethoxymethane and substituted anilines as start materials. Their structures were confirmed by 1H NMR, 13C NMR and HRMS spectra. Antimicrobial evaluation revealed that some of the target compounds could effectively inhibit microbial growth. Especially, carbothioamido hydrazonyl aminothiazolyl quinolone 8a showed strong inhibitory activity toward drug-resistant Staphylococcus aureus with MIC value of 0.0047 mM, which was 5-fold more active than that of norfloxacin. The highly active compound 8a exhibited negligible hemolysis, no significant toxicity in vitro and in vivo, low drug resistance, as well as rapidly bactericidal effects, which suggested its favorable druggability. Furthermore, compound 8a was able to effectively disrupt the integrity of the bacterial membrane, intercalate into DNA and inhibit the activity of topoisomerase IV, suggesting multitargeting mechanism of action. Compound 8a could form hydrogen bonds and hydrophobic interactions with DNA-topoisomerase IV complex, indicating the insertion of aminothiazolyl moiety was beneficial to improve antibacterial efficiency. These findings indicated that the active carbothioamido hydrazonyl aminothiazolyl quinolone 8a as a chemical therapeutic candidate demonstrated immense potential to tackle drug-resistant bacterial infections.

BACKGROUND: Quinolone antibiotics are extensively used clinically for human treatment and in agriculture. However, improper and excessive use can lead to the persistence of quinolone residues in animal tissues, potentially accumulating in the human body and posing health risks. Investigating the correlation between mass spectrometry cleavage patterns and molecular structural features enhances the analytical framework for detecting trace or unknown impurities in quinolones.
METHODS: To collect data, we employed triple quadrupole linear ion trap mass spectrometry in electrospray positive ion mode. Primary mass spectrometry scanning was utilized to confirm parent ions, while secondary mass spectrometry scanning enabled the observation of fragment ions. The cleavage characteristics and pathways of the compounds were inferred from accurate mass-to-charge ratios obtained from both primary and secondary mass spectrometry.
RESULTS: Under soft ionization conditions, the compounds generally exhibited characteristic fragment ions of [M+H-H2O]+, [M+H-CO]+, and [M+H-H2O-CO]+. Additionally, subtle variations were observed in each compound due to differences in modifying groups. For instance, upon deacidification, the piperazine ring structure underwent breakage and rearrangement, yielding fragment ion peaks devoid of neutral molecules such as C2H5N, C3H7N, or C4H8N. Notably, compounds featuring a cyclopropyl substituent group at the N-1 position typically exhibited characteristic fragments resulting from the loss of the cyclopropyl radical (⋅C3H5). Moreover, substituents at the N-1 and C-8 positions, when linked to form a six-membered carbocyclic ring, were prone to cleavage, releasing the neutral C3H6 molecule.
CONCLUSIONS: Quinolone antibiotics share structural similarities in their parent nuclei, leading to partially similar cleavage pathways. Nevertheless, distinct cleavage patterns emerge due to variations in functional groups. According to the difference of mass spectrometry cleavage patterns, it can provide an identification basis for the measured detection of antibiotics.

BACKGROUND: According to the World Health Organization, antimicrobial resistance (AMR) is a silent global pandemic that plagues everyone. It makes therapy of infectious diseases more difficult and eventually increases morbidity and mortality.
OBJECTIVE: The purpose of this work is to examine existing data on plasmid-mediated quinolone resistance (PMQR), to assess the prevalence of PMQR genes in Enterobacterales, and to determine any knowledge gaps from sub-Saharan Africa.
METHODS: The Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) standard was followed when conducting this systematic review. The main internet databases examined for pertinent publications were PubMed, Google Scholar, and Ajol. A set of qualifying criteria were used to evaluate the qualified articles. Using the eligibility criteria, 56 full-text articles were chosen for screening.
RESULTS: Thirty-two (32) articles with the majority originating from West and North Africa and only one article reporting a study carried out in Central Africa were selected for this review. Escherichia coli and Ciprofloxacin were the most reported Enterobacterales and Quinolone respectively. The PMQR genes include qnr (qnrA,qnrB, qnrC, qnrD, and qnrS), aac (6\') Ib, aac (6\') Ib-cr, oqxAB and qepA gene. The most prevalent PMQR gene is the aac (6\') Ib-cr gene (32%) followed by qnrS (26%).
CONCLUSIONS: This study highlighted the requirement for an efficient antimicrobial resistance surveillance system in the continent and revealed a significant incidence of PMQR genes.
BACKGROUND: Selon l\'Organisation mondiale de la santé, la résistance aux antimicrobiens (RAM) est une pandémie mondiale silencieuse qui touche tout le monde. Elle rend le traitement des maladies infectieuses plus difficile et finit par augmenter la morbidité et la mortalité.
OBJECTIVE: L\'objectif de ce travail est d\'examiner les données existantes sur la résistance plasmidique aux quinolones (PMQR), d\'évaluer la prévalence des gènes PMQR chez les Enterobacterales et de déterminer d\'éventuelles lacunes de connaissances en Afrique subsaharienne.
UNASSIGNED: La norme Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) a été suivie lors de la réalisation de cette revue systématique. Les principales bases de données Internet examinées pour des publications pertinentes étaient PubMed, Google Scholar et Ajol. Un ensemble de critères d\'admissibilité a été utilisé pour évaluer les articles qualifiés. En utilisant les critères d\'éligibilité, 56 articles en texte intégral ont été choisis pour le dépistage.
UNASSIGNED: Trente-deux (32) articles, dont la majorité provient d\'Afrique de l\'Ouest et du Nord, et un seul article rapportant une étude menée en Afrique centrale, ont été sélectionnés pour cette revue. Escherichia coli et la ciprofloxacine étaient les Enterobacterales et les quinolones les plus signalées respectivement. Les gènes PMQR comprennent les gènes qnr (qnrA, qnrB, qnrC, qnrD et qnrS), aac (6 \') Ib, aac (6 \') Ib-cr, oqxAB et qepA. Le gène PMQR le plus prévalent est le gène aac (6 \') Ib-cr (32 %), suivi de qnrS (26 %).
CONCLUSIONS: Cette étude a souligné la nécessité d\'un système efficace de surveillance de la résistance aux antimicrobiens sur le continen`t et a révélé une incidence significative des gènes PMQR.
UNASSIGNED: Enterobacterales, Escherichia coli, Quinolone, Ciprofloxacine, PMQR, \"aac(6\')-Ib\", \"aac(6\')-Ib-cr\", \"qnr\", \"qepA\", \"oqxAB\", \"résistance aux antibiotiques\".

We hypothesized that the residual concentrations of fluoroquinolones allowed in food (acceptable daily intake-ADIs) could select for ciprofloxacin resistance in our resident microbiota. We developed models of chronic Escherichia coli and Klebsiella pneumoniae infection in Galleria mellonella larvae and exposed them to ADI doses of ciprofloxacin via single dosing and daily dosing regimens. The emergence of ciprofloxacin resistance was assessed via isolation of the target bacteria in selective agar plates. Exposure to as low as one-tenth of the ADI dose of the single and daily dosing regimens of ciprofloxacin resulted in the selection of ciprofloxacin resistance in K. pneumoniae but not E. coli. This resistance was associated with cross-resistance to doxycycline and ceftriaxone. Whole genome sequencing revealed inactivating mutations in the transcription repressors, ramR and rrf2, as well as mutations in gyrA and gyrB. We found that ciprofloxacin doses 10-fold lower than those classified as acceptable for daily intake could induce resistance to ciprofloxacin in K. pneumoniae. These results suggest that it would be prudent to include the induction of antimicrobial resistance as a significant criterion for determining ADIs and the associated maximum residue limits in food.IMPORTANCEThis study found that the concentrations of ciprofloxacin/enrofloxacin allowed in food can induce de novo ciprofloxacin resistance in Klebsiella pneumoniae. This suggests that it would be prudent to reconsider the criteria used to determine \"safe\" upper concentration limits in food.

Prevalence of microbial infections and new rising pathogens are signified as causative agent for variety of serious and lethal health crisis in past years. Despite medical advances, bacterial and fungal infections continue to be a rising problem in the health care system. As more bacteria develop resistance to antibiotics used in therapy, and as more invasive microbial species develop resistance to conventional antimicrobial drugs. Relevant published publications from the last two decades, up to 2024, were systematically retrieved from the MEDLINE/PubMed, SCOPUS, EMBASE, and WOS databases using keywords such as quinolones, anti-infective, antibacterial, antimicrobial resistance and patents on quinolone derivatives. With an approach of considerable interest towards novel heterocyclic derivatives as novel anti-infective agents, researchers have explored these as essential tools in vistas of drug design and development. Among heterocycles, quinolones have been regarded extremely essential for the development of novel derivatives, even able to tackle the associated resistance issues. The quinolone scaffold with its bicyclic structure and specific functional groups such as the carbonyl and acidic groups, is indeed considered a valuable functionalities for further lead generation and optimization in drug discovery. Besides, the substitution at N-1, C-3 and C-7 positions also subjected to be having a significant role in anti-infective potential. In this article, we intend to highlight recent quinolone derivatives based on the SAR approach and anti-infective potential such as antibacterial, antifungal, antimalarial, antitubercular, antitrypanosomal and antiviral activities. Moreover, some recent patents granted on quinolone-containing derivatives as anti-infective agents have also been highlighted in tabular form. Due consideration of this, future research in this scaffold is expected to be useful for aspiring scientists to get pharmacologically significant leads.

Trends in and risk factors for drug resistance in Mycobacterium tuberculosis (M. tuberculosis) in human immunodeficiency virus (HIV)-infected patients with active tuberculosis were analyzed. The clinical data of M. tuberculosis and HIV-coinfected patients treated at the Shanghai Public Health Clinical Center between 2010 and 2022 were collected. The diagnosis of tuberculosis was confirmed by solid or liquid culture. The phenotypic drug susceptibility test was carried out via the proportional method, and the resistance to first-line and second-line drugs was analyzed. Logistic regression analysis was performed to identify associated risk factors for drug resistance in M. tuberculosis. Of the 304 patients with a M. tuberculosis-positive culture and first-line drug susceptibility test results, 114 (37.5%) were resistant to at least one first-line anti-tuberculosis drug. Of the 93 patients with first-line and second-line drug susceptibility test results, 40 (43%) were resistant to at least one anti-tuberculosis drug, and 20 (21.5%), 27 (29.0%), 19 (20.4%), 16 (17.2%), and 14 (15.1%) were resistant to rifampicin, streptomycin, ofloxacin, levofloxacin, and moxifloxacin, respectively; 17 patients (18.3%) had multidrug-resistant tuberculosis (MDR-TB). Between 2010 and 2021, the rate of resistance to streptomycin and rifampicin ranged from 14.3% to 40.0% and from 8.0% to 26.3%, respectively, showing an increasing trend year by year. From 2016 to 2021, the rate of resistance to quinolones fluctuated between 7.7% and 27.8%, exhibiting an overall upward trend. Logistic regression analysis showed that being aged <60 years old was a risk factor for streptomycin resistance, mono-drug resistance, and any-drug resistance (RR 4.139, p = 0.023; RR 7.734, p = 0.047; RR 3.733, p = 0.009). Retreatment tuberculosis was a risk factor for resistance to rifampicin, ofloxacin, of levofloxacin (RR 2.984, p = 0.047; RR 4.517, p = 0.038; RR 6.277, p = 0.014). The drug resistance rates of M. tuberculosis to rifampicin and to quinolones in HIV/AIDS patients were high and have been increasing year by year. Age and a history of previous anti-tuberculosis treatment were the main factors associated with the development of drug resistance in HIV/AIDS patients with tuberculosis.

Malaria continues to be a serious and debilitating disease. The emergence and spread of high-level resistance to multiple antimalarial drugs by Plasmodium falciparum has brought about an urgent need for new treatments that will be active against multidrug resistant malaria infections. One such treatment, ELQ-331 (MMV-167), an alkoxy carbonate prodrug of 4(1H)-quinolone ELQ-300, is currently in preclinical development with the Medicines for Malaria Venture. Clinical development of ELQ-331 or similar compounds will require the availability of isotopically labeled analogs. Unfortunately, a suitable method for the deuteration of these important compounds was not found in the literature. Here, we describe a facile and scalable method for the deuteration of 4(1H)-quinolone ELQ-300, its alkoxycarbonate prodrug ELQ-331, and their respective N-oxides using deuterated acetic acid.

UNASSIGNED: Levofloxacin is widely used because of its broad-spectrum antimicrobial activity and convenient dosing schedule. However, the relevance of its use in children remains to be investigated. The purpose of this study is to investigate the efficacy and safety of levofloxacin use in children with severe infections.
UNASSIGNED: We conducted a retrospective observational study of patients <18 years of age who received levofloxacin intravenously in the Pediatric Intensive Care Unit (PICU) of our hospital during the period between 2021 and 2022. Patient demographics, course characteristics, clinical effectiveness, and adverse event correlations were extracted through a retrospective tabular review.
UNASSIGNED: We included 25 patients treated with 28 courses of levofloxacin. The mean age of these children treated with levofloxacin was 4.41 years. Conversion of pathogenic microbiological test results to negative after levofloxacin treatment was detected in 11 courses (39.29%). A decrease in inflammatory markers, white blood cell or C-reactive protein counts, was detected in 18 courses (64.29%). A total of 57 adverse events occurred during the treatment period, of which 21 were possibly related to levofloxacin and no adverse events were probably related to levofloxacin.
UNASSIGNED: The effectiveness of levofloxacin use in children with serious infections is promising, especially for the treatment of multidrug-resistant bacteria. Adverse events occurring during the initiation of levofloxacin therapy in children are reported to be relatively common, but in this study, only a small percentage of them were possibly related to levofloxacin, and none of them were highly possibly related to levofloxacin.

Quinolone is a heterocyclic compound containing carbonyl at the C-2 or C-4 positions with nitrogen at the C-1 position. The scaffold was first identified for its antibacterial properties, and the derivatives were known to possess many pharmacological activities, including anticancer. In this review, the quinolin-2(H)-one and quinolin-4(H)-one derivatives were identified to inhibit several various proteins and enzymes involved in cancer cell growth, such as topoisomerase, mi-crotubules, protein kinases, phosphoinositide 3-kinases (PI3K) and histone deacetylase (HDAC). Hybrids of quinolone with curcumin or chalcone, 2-phenylpyrroloquinolin-4-one and 4-quinolone derivatives have demonstrated strong potency against cancer cell lines. Additionally, quinolones have been explored as inhibitors of protein kinases, including EGFR and VEGFR. Therefore, this review aims to consolidate the medicinal chemistry of quinolone derivatives in the pipeline and discuss their similarities in terms of their pharmacokinetic profiles and potential target sites to provide an understanding of the structural requirements of anticancer quinolones.

Background: Prophylactic antibacterial drugs are used for patients with liver cirrhosis and upper gastrointestinal bleeding, and independent studies have concluded that they can decrease the rate of infection, mortality, and rebleeding in these diseases. However, no comprehensive assessment of this effect has been reported in recent years and available data pertaining to the prognostic implications of diverse categories of antibiotic prophylaxis in individuals afflicted with cirrhosis are notably limited. The objective of this article is to assess the clinical effectiveness of prophylactic antibacterial drugs for patients with liver cirrhosis and upper gastrointestinal bleeding. Methods: Relevant randomized controlled studies and cohort studies which examined the value of prophylactic antibacterial drugs for patients with liver cirrhosis and upper gastrointestinal bleeding were retrieved via Cochrane Library, EMBASE, MedLine, and Web of Science. The search period was from database inception until 30 April 2023. Summing up the relevant data, the dichotomous variable was statistically analysed using the relative risk (RR) value and its 95% confidence interval (CI) and the continuous variable using the mean difference (MD) value and its 95% CI. All analyses were performed using Revman 5.4 software. The study has been registered on the PROSPERO website under registration number CRD42022343352. Results: Twenty-six studies (18 RCTs and 8 cohort studies, including 13,670 participants) were included to evaluate the effect of antibacterial prophylaxis versus no antibacterial prophylaxis or placebo. Prophylactic antibiotics reduced mortality rates (RR 0.66, 95% CI 0.51-0.83), infection rates (RR 0.41, 95% CI 0.35-0.49), rebleeding rates (RR 0.42, 95% CI 0.31-0.56), and length of hospital stay (MD -5.29, 95% CI -7.53, -3.04). Subgroup analysis revealed that the prophylactic administration of quinolone antimicrobials demonstrated the most favorable efficacy, followed by cephalosporins. Both interventions were effective in averting infections frequently observed in patients with liver cirrhosis and upper gastrointestinal bleeding. Conclusion: Based on our investigation, the prophylactic antibacterial drugs confers noteworthy advantages in patients afflicted by liver cirrhosis with upper gastrointestinal bleeding. It has been associated with reductions in mortality, infection incidence, rebleeding occurrences, and the duration of hospitalization. Among prophylactic antibacterial options, quinolones emerged as the foremost choice, with cephalosporins ranking closely thereafter. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022343352, identifier CRD42022343352.