nalidixic acid / Generic mfg. - LARVOL DELTA

Whole-Genome Sequencing Reveals Virulence and Antimicrobial Resistance Determinants of Lactococcus garvieae Causing Lactococcosis in Cage-Cultured Nile Tilapia (Oreochromis niloticus) in Thailand. (PubMed, Int J Mol Sci) - "Antimicrobial susceptibility testing showed resistance to nalidixic acid, oxolinic acid, and oxacillin, while reduced inhibition zones were observed for enrofloxacin and sulfamethoxazole-trimethoprim. Resistance-associated protein variants were detected in gyrA and gyrB, suggesting that target alteration may contribute to fluoroquinolone resistance. Overall, this study provides genome-level evidence of virulence and antimicrobial resistance determinants in L. garvieae from Thai tilapia and highlights the importance of whole-genome sequencing for accurate diagnosis, epidemiological surveillance, and disease management in aquaculture."

Journal • Hematological Disorders • Infectious Disease

Detection and antimicrobial susceptibility patterns of Salmonella enterica subsp. arizonae and Proteus spp. associated with gastrointestinal disease in rescued hedgehogs (Erinaceus europaeus). (PubMed, Comp Immunol Microbiol Infect Dis) - "isolates were susceptible to cefotaxime, nalidixic acid, ciprofloxacin, levofloxacin, norfloxacin, amikacin, gentamicin, tobramycin, aztreonam, cefoxitin, ceftazidime and fosfomycin. However, resistance was observed to amoxicillin-clavulanic acid, ampicillin, ertapenem, meropenem, trimethoprim-sulfamethoxazole, cefuroxime, piperacillin-tazobactam, colistin and nitrofurantoin, with the latter two showing resistance in all Proteus spp...from hedgehog samples may display relevant antimicrobial resistance (AMR) patterns. Therefore, continuous bacteriological monitoring and antimicrobial susceptibility testing are important in wildlife rehabilitation settings to guide treatment decisions and support One Health surveillance."

Journal • Gastroenterology • Gastrointestinal Disorder • Infectious Disease

Antimicrobial and probiotic potential of Lactobacillus from traditional dairy products against uropathogenic gram-negative bacteria. (PubMed, Antonie Van Leeuwenhoek) - "Most isolates showed susceptibility or intermediate responses to several clinically relevant antibiotics, while resistance was mainly observed to vancomycin, penicillin G, piperacillin, and nalidixic acid. This repeated regimen also significantly controlled the inflammatory host response, with leukocyte counts decreasing from greater than 104 cells/mL to approximately 4 × 103 cells/mL by day 11, while successfully preventing kidney dissemination and minimizing bladder tissue damage. These findings highlight their potential as complementary strategies to prevent or mitigate UTIs."

Journal • Infectious Disease • Inflammation • Nephrology • Pneumonia • Renal Disease

Antimicrobial susceptibility patterns of commensal fecal bacteria isolated from pigs with an intentional genomic alteration that included the selectable marker gene nptII. (PubMed, Front Microbiol) - "Higher resistance rates in GalSafe™ pigs were observed only for quinolones in Campylobacter coli (ciprofloxacin and nalidixic acid) and nitrofurantoin in Enterococcus spp. However, the positive isolate did not appear to contain nptII derived from the GalSafe™ pig genome as the sequences flanking the gene did not match the IGA. We did not detect evidence of nptII gene transformation into bacterial species of potential human health importance in this population of GalSafe™ pigs."

Journal • Gene Therapies

Genomic insights into Aeromonas infections in diarrheal patients: high diversity, emerging resistance, and potential outbreak in Beijing. (PubMed, Front Microbiol) - "Resistance rates were notably high for ampicillin/ampicillin-sulbactam (78.26%), nalidixic acid (56.52%), and ertapenem (21.73%), and 65.21% of isolates were multidrug-resistant. Collectively, this study delineates high genetic diversity, emerging chromosomal colistin resistance, and species-specific virulence specialization among Aeromonas isolates from diarrheal patients in Beijing. The detection of a potential outbreak cluster and a rare clinical isolate underscores the power of genomics-based surveillance for detecting and mitigating foodborne pathogen threats."

Journal • Infectious Disease

Prevalence and Antimicrobial Resistance of Diarrhoeagenic Escherichia coli and Cytolethal Distending Toxin-producing Escherichia coli in Children from North India. (PubMed, Indian J Med Microbiol) - "The high prevalence of antimicrobial resistance among DEC highlights the need for strengthened AMR surveillance and antimicrobial stewardship. Although the prevalence of CDT-producing E. coli was low, their predominance among diarrhoeal cases highlights the need for larger multicentric studies to determine their clinical and epidemiological significance."

Journal • Pediatrics

Phenotypic Antimicrobial Resistance in Escherichia coli and Salmonella spp. Recovered from Broiler-Farm Environmental Matrices in Morocco. (PubMed, Antibiotics (Basel)) - "Disk-diffusion results were interpreted using applicable CLSI M100, 31st edition, criteria, and colistin was tested by the colistin broth disk elution MIC method...The predominant resistance rates were ampicillin (84.7%), tetracycline (61.6%), and chloramphenicol (55.8%) in E. coli, and nalidixic acid (73.2%), ampicillin (61.4%), and tetracycline (55.9%) in Salmonella spp...The findings provide baseline evidence supporting integrated One Health surveillance, improved biosecurity, manure and litter management, water-system sanitation, and responsible veterinary antimicrobial use. Genomic typing and environmental source-tracking are required to determine persistence and transmission pathways."

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Prevalence and Characteristics of Salmonella from a Laying Hen Production Chain in Jiangsu Province, China. (PubMed, Microorganisms) - "Among the 16 antibiotics tested, 30 selected strains exhibited 100% resistance to nalidixic acid (NAL) and ciprofloxacin (CIP), attributed to mutations in the quinolone resistance-determining region (QRDR) of the gyrA gene. Following this, the resistance rates for ampicillin (AMP), amoxicillin-clavulanate (AMC), and streptomycin (STR) were 56.7%...Furthermore, 165 virulence-associated genes were identified among the investigated isolates, indicating a highly conserved virulence repertoire. This study investigates the prevalence of Salmonella within a laying hen production chain, providing a scientific foundation for the effective prevention and control of Salmonella infection."

Journal • Infectious Disease

Prevalence, Serotype Distribution, and Antimicrobial Resistance of Streptococcus agalactiae Among Pregnant Women in Greece: A Retrospective Study. (PubMed, J Clin Med) - "Samples were processed using Todd-Hewitt broth with colistin and nalidixic acid, and cultured on blood agar and chromogenic media. The VITEK2 system was used for GBS identification and antimicrobial susceptibility testing against penicillin, erythromycin, clindamycin, tetracycline, levofloxacin, and vancomycin, according to EUCAST guidelines... GBS colonization was detected in 12.5% of pregnant women, with serotype III predominating, underscoring its clinical relevance due to its association with invasive neonatal disease. Although penicillin remains fully effective, the observed resistance to macrolides and lincosamides, primarily mediated by the cMLSB phenotype, raises concerns regarding alternative therapies."

Journal • Retrospective data • Infectious Disease

Molecular characterization of Vibrio cholerae strains from clinical samples during the 2025 epidemic in the Republic of the Congo. (PubMed, IJID Reg) - "The strains were resistant to ampicillin and nalidixic acid and sensitive to ciprofloxacin and doxycycline. These results reveal the emergence of a virulent and multiresistant strain of V. cholerae O1 Ogawa in the Republic of the Congo, closely related to Nigerian strains. Its control requires cross-border coordination focused on genomic surveillance and mass vaccination."

Journal • Cholera

Multidrug-resistant Enterobacterales causing wound infections in Ibadan, Nigeria: Phenotypic resistance and detection of bla KPC, bla OXA-48, and mcr genes. (PubMed, IJID Reg) - "Of the 74 Enterobacterales, resistance was highest (>91%) against third-generation cephalosporins and amoxicillin-clavulanate, nalidixic acid (90.5%), gentamicin (81.1%), and imipenem (80%). MDR-Enterobacterales account for about a quarter of the etiological agents of wound infections, with major implications for surgical site infections, as their extensive resistance profiles threaten the effectiveness of empirical therapy, increase the risk of treatment-refractory postoperative infections, and facilitate rapid hospital spread. The detection of Enterobacterales of critical priority carrying colistin- and carbapenem-resistance genes underscores the need for local genomic surveillance to monitor and control their spread; coordinated health system planning to ensure sustained access to effective antibiotics; strengthening infection prevention and control practices; improving antimicrobial stewardship; and implementing targeted patient-level risk-factor management."

Journal • Diabetes • Infectious Disease • Metabolic Disorders

Quinolone resistance of Pseudomonas aeruginosa isolated from hospital infections and MexAB-OprM efflux pumps. (PubMed, Int Microbiol) - "The findings demonstrate a strong association between the presence of the mexAB-oprM determinant and elevated quinolone resistance in clinical P. aeruginosa isolates. The significant reduction in MIC values following PAβN exposure supports the contribution of RND-type efflux mechanisms to resistance. However, given the intrinsic nature of MexAB-OprM and the broad inhibitory spectrum of PAβN, these results should be interpreted as correlative rather than causative. These data underscore efflux activity as a key resistance factor and highlight the need for expression-based profiling in future mechanistic studies."

Journal • Infectious Disease

Effects of a triple-strain Bacillus-based probiotic on cecal and ovarian colonization of Salmonella Enteritidis in commercial pullets. (PubMed, Vet Anim Sci) - "At 16 weeks of age, birds were orally challenged with 3.9 × 10⁸ CFU of a nalidixic acid-resistant SE strain...No differences in SE prevalence were detected in ceca or ovaries between treatments. These findings indicate that dietary supplementation with a multi-strain Bacillus-based probiotic may contribute to transient reductions in intestinal Salmonella Enteritidis load in layer pullets following a challenge, although effects on systemic invasion were not observed."

Journal • Infectious Disease

Antimicrobial resistance and genomic characteristics of Salmonella from diarrhea patients in Jiamusi City, 2015-2023 (PubMed, Zhonghua Yu Fang Yi Xue Za Zhi) - "The isolates exhibited resistance to streptomycin, ampicillin, tetracycline, and nalidixic acid. Virulence factors were predominantly associated with secretion systems and fimbrial adherence. In conclusion, in Jiamusi City, Salmonella Enteritidis is the dominant serovar, multidrug-resistant Salmonella is prevalent, aminoglycoside resistance genes are highly prevalent, chromosomal mutations dominate the resistance mechanism, genetic relatedness exists among the isolates, and virulence genes are abundant, indicating strong pathogenic potential."

Journal

From Antibacterial to Antifungal: Structure, Safety, and Serum Albumin Binding of Zn(II)-Nalidixate Complexes with Phenanthroline and Bipyridine. (PubMed, Biol Trace Elem Res) - "Nalidixic acid (Nal) is a quinolone antibiotic with activity against Gram-negative bacteria and is used to treat urinary tract infections caused by microorganisms belonging to the genera Escherichia, Proteus, Shigella, Enterobacter, and Klebsiella...Furthermore, both ternary complexes showed an improved safety profile compared to Nal alone. Besides, zinc(II) complexes can be efficiently transported by albumin, which is a key factor in their potential therapeutic application."

Journal • Infectious Disease • Nephrology

Evaluation of Oxford nanopore sequencing for antimicrobial resistance surveillance in Salmonella: comparison with phenotypic antimicrobial susceptibility in a large-scale study. (PubMed, Microbiol Spectr) - "Notable discrepancies included tigecycline resistance without known genetic determinants, nalidixic acid resistance linked to ramAp-mediated MIC elevation, and a high prevalence of colistin resistance (35.7%) in S. Enteritidis, with most resistant isolates lacking identifiable AMR determinants. Additionally, a significant proportion of ESBL- and AmpC-producing isolates were classified as susceptible or intermediate to cefotaxime and ceftazidime under CLSI criteria, highlighting the potential for misclassification and treatment failure...We further identify four major mechanisms underlying genotype-phenotype discordance, including breakpoint-dependent classification, reduced or absent phenotypic expression of resistance genes, minimum inhibitory concentration (MIC) modulation by ramAp, and the absence of known AMR determinants. These findings demonstrate how WGS can complement conventional AST, improve interpretation of challenging susceptibility results, and strengthen..."

Journal • Infectious Disease

Phylogenetic analysis and characterization of hybrid enteroaggregative/uropathogenic Escherichia coli strains isolated from urinary tract infection. (PubMed, Mol Biol Rep) - "This study identified 8.5% of urinary E. coli isolates as hybrid EAEC/UPEC strains. High multidrug resistance, particularly to trimethoprim-sulfamethoxazole, nalidixic acid, and cefotaxime, underscores major therapeutic challenges. These findings highlight the clinical importance of emerging hybrid pathotypes and the need for strengthened molecular surveillance."

Journal • Gene Therapies • Infectious Disease • Nephrology

Prevalence of Mastitis in Cows and Raw Milk Microbial Contamination in Selected Districts, Tanzania. (PubMed, Vet Med Sci) - "A high prevalence of mastitis implies losses to farmers due to poor production and threatens public health from milk-borne diseases. This calls for urgent intervention measures to control mastitis, combat antimicrobial resistance and safeguard public health."

Journal • Infectious Disease

Fungicide Drives De Novo Evolution of Multidrug Resistance in the Plant Growth Promoting Rhizobacterium, Pseudomonas fluorescens. (PubMed, Evol Appl) - "Fungicide exposure rapidly selected for increased fungicide resistance, detectable as early as week 4, and co-selected for resistance to chloramphenicol, sulphatriad and nalidixic acid antibiotics, likely through mutations in a mexS ortholog that may be associated with efflux pump overexpression. Warming did not alter the evolution of fungicide resistance; however, populations subjected to both fungicide and warming stress went extinct more rapidly, so that population evolutionary rescue was less effective under dual stress. Our findings show that fungicide alone can drive multidrug resistance in beneficial soil bacteria, suggesting that non-antibiotic drivers of resistance in the environment should be incorporated into One Health frameworks for tackling AMR."

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Multidrug-resistant and virulence traits in genetically distinct vesicular Leptospira inhabiting farmland and sewage in Southern India. (PubMed, Sci Rep) - "All strains were resistant to vancomycin, rifamycin, aztreonam, lincomycin, nalidixic acid, minocycline and troleandomycin and carried genes for a multitude of proteins conferring drug-resistant mechanisms. We suggest the inclusion of L. levettii SA-E5, L. kmetyi SA-E7, L. koniambonensis SA-E9 and Leptospira sp. SA-E8 in the array of leptospiral antigens being used in sero-epidemiological studies to establish their seroprevalence in humans, rodents and livestock."

Journal • Hematological Disorders

The SOS response acts as a regulatory switch that balances helicase anti-recombination with transcription-replication conflict resolution activities in Escherichia coli. (PubMed, G3 (Bethesda)) - "Under nalidixic acid treatment, where survival relies mainly on double-strand break repair, we observed a similar SOS-dependent modulation of helicase activity, reinforcing this regulatory model. Together, these findings uncover a dynamic regulatory mechanism that fine-tunes helicase activities to resolve transcription-replication conflicts while limiting deleterious anti-recombination, thereby preserving chromosome integrity under transcriptional or antibiotic-induced stress."

Journal

Molecular Characterization of Multidrug-Resistant Escherichia coli Isolated from Beef and Chicken Meat Products in Samsun, Türkiye. (PubMed, Antibiotics (Basel)) - "Antimicrobial susceptibility testing demonstrated high resistance rates to tetracycline (69.7%), ampicillin (58.4%), trimethoprim-sulfamethoxazole (48.1%), streptomycin (40.5%), nalidixic acid (40.0%), chloramphenicol (40.0%), and ciprofloxacin (34.1%). In contrast, the lowest resistance rates were observed for imipenem (2.2%), amoxicillin-clavulanate (4.9%), and amikacin (7.6%)... The coexistence of virulence-associated genes and high AMR rates among E. coli isolates from meat products indicates a potential public health risk. These findings highlight the importance of continuous monitoring of pathogenic and antimicrobial-resistant E. coli throughout the food production chain."

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Antiparasitic effects of topoisomerase II inhibitors on Giardia intestinalis trophozoites. (PubMed, Acta Trop) - "Trophozoites were exposed to 1, 5, 10, or 20 μM nalidixic acid, enoxacin, or norfloxacin. In silico analysis suggested that the compounds could interact with GiTopo2 and DNA strands. These findings support the potential of topoisomerase inhibitors as promising candidates for alternative or adjunct therapies for giardiasis."

Journal • Infectious Disease

Occurrence of multidrug-resistant Salmonella species with resistance genes in recreational surface waters in southern Illinois. (PubMed, J Environ Sci (China)) - "Salmonella isolates showed resistance to ampicillin (70 %), azithromycin (57 %), tetracycline (34 %), gentamicin (9 %), ciprofloxacin (6 %), and nalidixic acid (6 %). Multiple antibiotic resistance indices were highest at Richland Creek near urban areas and a wastewater treatment plant, reflecting land use influence on AMR. These findings highlight the need for integrated AMR control under a One Health approach to protect global health."

Journal • Infectious Disease

Prevalence of Bacterial Pathogens, Antimicrobial Resistance and Quality Attributes of Raw Meat and Meat Products sold at Traditional Markets in Arequipa, Peru. (PubMed, J Food Prot) - "isolates showed maximum resistance to nalidixic acid (74.6%) and doxycycline (90.5%), respectively. Nevertheless, physicochemical and sensory analyses revealed no signs of spoilage. These findings underscore serious microbiological hazards and warrant stricter sanitary interventions."

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