Antibiotic Resistance Research Articles

Aliphatic Disinfection Byproducts Induced Antibiotic Resistance in Escherichia coli through Cell Wall Alteration.

Disinfection is a critical step in drinking water treatment, yet studies revealed that it would promote the dissemination of antibiotic resistance, and disinfection byproducts (DBPs) may act as contributors. In this study, we conducted a high-throughput assessment of antibiotic resistance development in the model strain Escherichia coli K12 after 50-day exposure to 15 aliphatic DBPs commonly found in drinking water against 8 different classes of antibiotics. The results showed that most treated bacteria developed resistance to cell wall-targeting antibiotics such as ampicillin and fosfomycin, with resistance levels increasing by 1.16- to 6.39-fold, higher than for other classes of antibiotics. Multidrug resistance was observed in the tribromoacetonitrile (TBAN), bromonitromethane (BNM), and dibromonitromethane (DBNM) groups. DBPs exposure induced the accumulation of reactive oxygen species (ROS) and damaged the bacterial cell membrane. Genomic and transcriptomic analyses revealed mutations and differential expression in genes related to cell wall synthesis and structure, indicating that exposure to DBPs will influence the bacterial cell wall. Nontargeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis further confirmed the cell wall structure alteration by the increased proportion of noncanonical d-amino acids in peptidoglycan, the major component of the cell wall, potentially explaining the observed resistance to cell wall-targeting antibiotics. Collectively, this study highlights the risk of aliphatic DBPs-induced antibiotic resistance, likely driven by alterations in the bacterial cell wall.

Adaptive laboratory-evolved MRSA with PPEF manifests cross-susceptibility to oxacillin and hypersensitivity to ciprofloxacin.

Emerging resistance to current antibiotics is a global threat to human health. Therefore, comprehending the mechanism behind antibiotic resistance holds paramount importance. In the pursuit of finding new antibacterial agents, our group has developed a small molecule, PPEF (2'-(4-ethoxyphenyl)-5-(4-propylpiperazin-1-yl)-1H,1'H-2,5'-bibenzo(d)imidazole), having bisbenzimidazole as a pharmacophore, targeting bacterial type IA topoisomerase, a novel drug target in bacteria. We examined the emergence of mutations leading to PPEF resistance in laboratory-evolved Staphylococcus aureus strains. The growth curve revealed that S. aureus 25923 PPEF-resistant (SA-PR) and methicillin-resistant S. aureus 43300 PPEF-resistant (MRSA-PR) attained stationary phase earlier than their respective reference strains. RNA sequencing analysis revealed that atpD (ATP synthase gene) was downregulated by 2 log2-fold in both SA-PR and MRSA-PR strains, whereas there was 10 to 13 log2-fold downregulation of mecR1 (methicillin resistance-inducing gene), ble (bleomycin resistance-inducing gene), blaZ (beta-lactamase), pbp (penicillin-binding protein gene), ermA (rRNA adenine methyltransferase gene), and kdpB (potassium-transporting ATPase) in the MRSA-PR strain. Quantitative reverse-transcriptase PCR data confirmed these results. Additionally, MRSA-PR showed a 5 log2-fold upregulation of comG and a 9 log2-fold downregulation of topB, indicating increased genomic variability and stress adaptation contributing to resistance. Genomic sequencing revealed deletions of resistance genes, including aac(6')-aph(2''), aadD, mecA, and blaZ in MRSA-PR, resulting in a gain in resistance and a diminishing returns epistasis pattern in PPEF-evolved S. aureus strains. This led to the development of an evolved MRSA-PR strain susceptible to oxacillin, ciprofloxacin, gentamicin, and imipenem. Our findings indicate that adaptation to PPEF has increased antibiotic susceptibility, thereby changing the clinical outcomes of infections.IMPORTANCEThis study investigates how Staphylococcus aureus bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) strain, develop resistance to a new candidate antibacterial compound, PPEF (2'-(4-ethoxyphenyl)-5-(4-propylpiperazin-1-yl)-1H,1'H-2,5'-bibenzo(d)imidazole). The research found that resistant strains grew slower and showed significant changes in the activity of genes related to antibiotic resistance. Some resistance genes were deleted in the resistant MRSA strain, making it more sensitive to other antibiotics like oxacillin and ciprofloxacin. These findings highlight how resistance to PPEF leads to increased sensitivity to conventional antibiotics. This suggests that developing combination therapies of PPEF with other antibiotics could optimize treatment regimens and slow resistance evolution. This study also indicates that the antibiotic regimens could be designed to force resistant bacteria into evolutionary trade-offs, where they lose resistance to widely used antibiotics while gaining resistance to a new compound like PPEF.

Association of capsular types with antibiotic resistance and clinical prognosis in Acinetobacter baumannii

Objective: Analysis of antimicrobial resistance and clinical outcomes in patients infected with different KL types of Acinetobacter baumannii. Methods: This is a cross-sectional study. From 2011 to 2021, 675 non-repetitive A. baumannii strains were isolated from patients with bloodstream infection (BSI, 234 cases), hospital acquired pneumonia (HAP, 423 cases), intra-abdominal infection (IAI, 17 cases) and urinary tract infection (UTI, 1 case) in 10 hospitals across 8 provinces of China. KL types and resistance genes were identified using bioinformatics methods. The minimum inhibitory concentrations of different antibiotics against 675 A.baumannii strains were determined by agar or microbroth dilution method. Ten strains were randomly selected from each KL type using simple random sampling for whole blood survival experiments. Differences in hospitalization duration and clinical outcomes were analyzed among patients infected with different KL types. Results: The 675 patients were aged (59±20) years, including 460 males. The predominant KL types included KL2 (22.0%, 149 strains), KL3 (17.5%, 118 strains), KL210 (7.0%, 47 strains) and KL160 (7.0%, 47 strains), while non-predominant KL types accounted for 314 strains (46.5%). The four predominant KL types showed higher overall resistance rates to most antibiotics compared with non-predominant KL types (all P<0.05). KL2 (92.6%, 113 strains) showed higher resistance to sulfamethoxazole-trimethoprim than KL3 (55.9%, 66 strains) (P<0.05). KL2 (87.2%, 130 strains) and KL210 (91.5%, 43 strains) showed higher resistance to minocycline than KL3 (67.8%, 80 strains) and KL160 (66.0%, 31 strains) (all P<0.05). KL2 exhibited stronger whole blood survival capacity [(58.36±20.33)%] than other KL types (all P<0.05). The fatality rate of KL2-infected patients was 30.9% (46 cases), higher than that of patients infected with KL3 (11.9%, 14 cases) and KL210 (6.4%, 3 cases) (all P<0.05). The hospitalization duration [M(Q1,Q3)] of KL2-infected patients was 46.00 (26.50, 74.00) days, longer than that of patients infected with KL3 [30.00 (15.25, 40.75) days], KL210 [27.00 (21.00, 44.00) days], KL160 [27.00 (20.00, 34.00) days] and non-predominant KL types [25.00 (12.00, 40.00) days] (all P<0.05). Conclusions: Different KL types of A.baumannii show variations in antimicrobial resistance and clinical outcomes of infected patients. KL2 demonstrates higher resistance rates and is associated with poorer clinical prognosis.

The effect of stochastic noise on antibiotic resistance in intestinal flora

The effect of stochastic noise on antibiotic resistance in intestinal flora

Phytochemicals as emerging therapeutics for acne vulgaris: a comprehensive review

Abstract Background Interest in using phytochemicals and herbal medicines to treat skin conditions like acne vulgaris has grown steadily over the last few decades and is described as a chronic inflammatory condition of the pilosebaceous unit that affects teenagers and young adults. Its treatment emphasizes the four main factors that contribute to its development: inflammation, excessive growth of Cutibacterium acne, hyperkeratinization, and sebum production. Main body Topical retinoids, oral isotretinoin, benzoyl peroxide, and antibiotics are all part of the treatment. Herbal medicine is a potential complementary and alternative medicine approach in this respect. Additionally, this review gives a full picture concerning acne pathogenesis, molecular targets for acne treatment, antibiotic resistance and existing medications and their pros and cons, herbal skincare products, and bioactive plant chemicals. Short conclusion This comprehensive study offers proof that phytochemicals and medicinal plants act as promising therapies for mild to moderate acne vulgaris through shed light on medicinal plants that have a long history of use and have been shown to possess low adverse effects. These plants are a reliable source for the preparation of new drugs. However, to substantiate their efficacy and safety claims, higher-quality research and clinical trials are required.

Trends of Antibiotic Resistance Patterns and Bacteriological Profiles of Pathogens Associated with Genitourinary Infections in Secondary Healthcare Facilities in the Volta Region of Ghana

Urogenital infections contribute greatly to both hospital- and community-acquired infections. In Ghana, the prevalence of resistance to commonly used antibiotics is relatively high. This study sought to evaluate the antibiotic sensitivity of bacterial urogenital pathogens from patient samples in a regional and district hospital in the Volta Region of Ghana. A retrospective cross-sectional study was conducted using data obtained between January and December 2023 from Volta Regional Hospital and Margret Marquart Catholic Hospital. Bacteria were isolated from urine, urethral swabs, and vaginal swabs from 204 patients. Data on culture and sensitivity assays performed using the Kirby–Bauer disc diffusion method were extracted and analyzed using WHONET. The most prevalent organisms isolated from the samples from both facilities were Escherichia coli (24.9%), Staphylococcus aureus (21.5%), and Klebsiella oxytoca (8.8%). The isolates were mostly resistant to amoxicillin/clavulanic acid (n = 75, 95% CI [91.8–99.9]), meropenem (n = 61, 95% CI [87.6–99.4]), cefuroxime (n = 54, 95% CI [78.9–96.5]), ampicillin (n = 124, 95% CI [61.2–77.9]), and piperacillin (n = 43, 95% CI [82.9–99.2]). Multidrug-resistant (MDR, 70 (34.1%)), extensively drug-resistant (XDR, 63 (30.7%)), and pandrug-resistant (PDR, 9 (4.3%)) strains of S. aureus, E. coli, and Pseudomonas aeruginosa were identified from the patient samples. The study highlights the presence of high-priority resistant urogenital pathogens of public health significance to varied antibiotic groups.

In vitro antibacterial activity of myco-synthesized selenium nanoparticles against a multidrug-resistant E. coli isolated from clinical specimens

Abstract Nosocomial infections are a major concern worldwide. Currently, addressing this issue presents several challenges due to the increasing rise of microbial antibiotic resistance. The present study isolated and identified multidrug-resistant Escherichia coli MED10, which is compatible with nosocomial pathogens in humans, using 16 S rRNA gene sequencing. Myco-synthesized selenium nanoparticles (Se NPs) produced by Fusarium fujikuroi MED14 were characterized through ultraviolet-visible spectroscopy, X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, Zeta potential, and transmission electron microscopy (TEM) analyses. Structural characterization of Se NPs revealed spherical shapes measuring 10–19 nm, along with a broad absorption peak at 240–270 nm. XRD indicated that the crystal planes were 100, 101, 222, and 102. FTIR confirmed the presence of proteins, as well as amide I, amide II, and amide III, corresponding to the peaks observed at 2358 cm-1, 1645 cm-1, 1566 cm-1, and 1254 cm-1, respectively. The measured zeta potential of Se NPs was − 43 mV, indicating a highly negative surface charge that reflects their excellent colloidal stability and resistance to aggregation. Antibacterial effects of Se NPs against E. coli MED10, E. coli ATCC 25,922, and Bacillus cereus ATCC 14,579 were examined using the minimum inhibition concentration test (MIC values of 160, 100, and 90 µg/ml, respectively) as well as the lowest bactericidal concentration test (MBC values of 170, 110, and 90 µg/ml, respectively). Ultrastructural studies on Se NPs-treated E. coli MED10 cells revealed wrinkled and damaged rod shapes, with detachment observed between the cell wall and plasma membrane compared to untreated cells. This investigation reported that myco-synthesized Se NPs, coated with crude metabolites of F. fujikuroi MED14, may act as a synergistic system to help control multidrug-resistant bacteria, including nosocomial E. coli MED10.

Evaluation of Antibiotic Susceptibility Pattern of S. Pneumoniae Isolated from Patients with Respiratory Tract Infections in General Hospital Dutsin-Ma, Katsina State, Nigeria

Streptococcus pneumoniae is one of the leading causes of bacterial infections, posing a major public health challenge ranging from self-limiting respiratory tract infections to severe invasive infections. The aim of the research is to determine the antibiotic susceptibility profile of S. pneumoniae isolated from patients with respiratory tract infections in General Hospital Dutsin-Ma, Katsina State. A total of twenty (50) sputum sample of patients with RTI were collected from Malam Mande General Hospital Dutsin-Ma in sterile small containers under aseptic condition and taken to Microbiology laboratory of Federal University Dutsin-Ma for microbiological analysis. The samples were inoculated into Nutrient Agar and Blood Agar medium for differentiation, and incubated at 37℃ for 24hrs, and pure isolates were identified based on their morphology and biochemical characteristics. Kirby-banner disc differential method was used to determine the antibiotics susceptibility profile of the isolates. Out of the 50 samples 18 S. pneumonia were isolated phenotypically. The isolates showed high resistance to Ampiclox (72.2%) and Amoxicillin (44.4%), and relatively higher susceptibility to Ciprofloxacin (44.4%) and Gentamycin (50%). The result also showed that 66.67% of the isolates are MDR. These findings highlight the need for continuous surveillance, antibiotic stewardship, alternative treatment strategies, public health education, and further research to manage infections effectively and combat antibiotic resistance.

P28 Antibiotic susceptibility testing of coagulase-negative staphylococci species isolates from the Royal Orthopaedic Hospital, Birmingham

Abstract Background Coagulase-negative staphylococci (CNS) are often considered non-pathogenic; however, they can be a major cause of chronic prosthetic joint infections (PJIs), associated with significant morbidity, mortality, and healthcare costs in the UK. Oral antibiotic options are often limited due to resistance, making IV glycopeptide antibiotics (vancomycin and teicoplanin) the preferred first-line treatment. While vancomycin-resistant isolates are rare, susceptibility to teicoplanin can vary, with some studies indicating that resistance may occur in up to a quarter of cases. Teicoplanin once daily administration provides significant benefits for managing outpatient treatment of certain patients with PJIs, compared to vancomycin, which requires twice-daily dosing. Objectives The study aimed to assess local antibiotic susceptibility data in CNS over the past five years, particularly in patients with bone and joint infections from the Royal Orthopaedic Hospital, Birmingham. The secondary objective was to determine the teicoplanin, daptomycin, and linezolid susceptibility profile of the included isolates. Methods This retrospective study involved a search of the Laboratory Information Management System (Telepath) to identify all isolates of CNS, including Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis and Staphylococcus capitis from bone, tissue, or fluid samples obtained from patients who underwent operations at the Royal Orthopaedic Hospital in Birmingham, one of the largest centres of its kind in Europe. MALDI-TOF MS (bioMérieux) was used for rapid and accurate species identification, while VITEK2® (bioMérieux) was employed for antimicrobial susceptibility testing. Teicoplanin susceptibility was assessed using the Etest® teicoplanin (bioMérieux) and EUCAST breakpoints (≤4 = susceptible, &amp;gt;4 = resistant). Results We identified a total of 683 specimens that met the eligibility criteria. After excluding duplicate isolates and focusing on those that underwent a teicoplanin e-test, we included 47 isolates in the study. The median age of the patients was 69 years, including 29 males (62%) and 18 females (38%). The primary infection sites included the knee joint (36%) and hip joints (34%), followed by the shoulder, ankle joints, and miscellaneous specimens. S. epidermidis was the predominant species isolated from the analysed specimens (n=45, 96%). All isolates showed susceptibility to vancomycin, daptomycin, and linezolid. The highest antibiotic resistance recorded was for clindamycin (n=39, 83%), followed by trimethoprim (n=37, 79%) and fluoroquinolones (ciprofloxacin, 65%). Susceptibility testing for additional oral agents revealed significant resistance to tetracycline (n=28, 60%). and rifampicin (n=20, 42%). Results for teicoplanin susceptibility indicated that 16 (34%) isolates exhibited resistance based on EUCAST breakpoints. Among all isolates, 21 (45%) were sensitive to at least one oral option besides linezolid. Notably, we observed an increased rate of teicoplanin resistance in 2023 and 2024 compared to 2020 and 2022. The study did not assess the impact of antibiotic use or other factors that could contribute to antibiotic resistance. Conclusions S. epidermidis was the predominant species identified among CNS associated with bone and joint infections. Most isolates exhibited resistance to commonly prescribed oral antibiotics. Furthermore, there has been a growing resistance to teicoplanin over the years, necessitating the need for further studies to explore the underlying factors.

O07 Educating the public on antimicrobial resistance and stewardship: is there a need to re-direct UK public health campaigns?

Abstract Background To engage with the public during World Antimicrobial Resistance Awareness Week (WAAW) 2024, several UK local, regional and national organizations, comprising Health Innovation East, Cambridgeshire &amp; Peterborough ICS, Antibiotic Research UK (ANTRUK), and NHSE East of England (EOE), came together and launched an e-platform containing an interactive quiz. This project provided a digital, collaborative and cost-effective way of harnessing the WAAW 2024 theme: Educate, Advocate, Act Now. Objectives To engage with a wide audience on antimicrobial resistance (AMR) and antimicrobial stewardship (AMS); provide educational support on common themes around AMR and AMS; and understand the educational needs of the public on AMR and AMS. Methods We adapted an evidence-based quiz1 involving the Patient and Public Involvement panel from the charity (ANTRUK). A digital platform was built, containing the quiz, comprising a series of 10 true/false statements. Detailed responses, additional information and links to NHS resources were included as feedback when people submitted answers. Each completed quiz generated a donation for ANTRUK as an incentive to complete and submit. The e-platform was beta tested prior to launch, optional demographics were also collected: ethnicity, gender, age-group and post-code. The quiz was launched during a regional WAAW NHSE seminar and through local networks and communication teams from across the region and was live from 18 to 30 November 2024. Results The e-quiz was accessed 1876 times with a total of 576 completed responses. It was aimed at and promoted in the East of England but responses were received from across the UK. The two most common incorrect responses marked as True were 'Antibiotic resistance develops as our bodies change and get used to the antibiotics we take so they don't work on us anymore' and Antimicrobial stewardship is an important part of all shipping import processes'. Statistical analysis of number of correct responses for the East of England region (where this quiz was promoted) using a generalized linear mixed effects model (ANOVA and χ2) on following demographic data Index of Multiple Deprivation (derived from postcode) age, gender and ethnicity, found that ethnicity was the only statistically significant factor (P=0.0184) in number of correct responses. Conclusions The most incorrect replies occurred on the questions which focused on how AMR develops and what AMS is. Language used in public health campaigns might not resonate with the public, particularly with those from different ethnicities. More should be done on a national level to inform the public about AMR/AMS using simpler language. These results may be used by local and national policymakers to direct future public educational campaigns on AMR/AMS.

Trends in first positive culture results in major burn center over a ten-year period.

Patients with severe burns are more vulnerable to infection, sepsis, and death. With heavy use of antimicrobials, changes in burn wound microbial and antibiotic resistance patterns have been reported; however, the literature remains scarce. This study assessed wound colonization trends in first positive cultures in our burn unit over the last decade. This is a retrospective cohort study including all patients admitted to our burn unit from July 2013 to June 2023. Demographics, total burn surface area (TBSA), injury mechanism and admission information were obtained. Wound culture information including date of positive cultures, type of organisms, and antibiotic susceptibility data was also collected. Patients were stratified based on TBSA as small (<10%), moderate (10-19.9%), and severe burns (≥20%). Descriptive statistics were obtained. Generalized linear models were fit to assess the trends of positive cultures over time for the three TBSA strata. A total of 2755 patients were included; median age was 38years, 72.2% were male; 74.1%, 15.9%, and 10.1% presented with small, moderate, and severe burns, respectively. Wound cultures on initial presentation were performed in 40.3% of our population with 600 cases having positive first cultures; 84.7% grew Gram positive, 35.7% Gram negative, and 9.7% fungal organisms. Data showed an increase in Gram positive and fungal species over the study period in first positive cultures of severe burn patients. We also found increasing rates of resistance for several antibiotics, including erythromycin, oxacillin, and vancomycin. Future studies are warranted to evaluate changes in microorganism growth throughout the hospital course of severe burn patients.

Zataria multiflora essential oil: a potent agent with antibacterial, anti-NorA efflux pump and anti-biofilm activity against ciprofloxacin-resistant Staphylococcus aureus isolates from bovine mastitis.

Bovine mastitis is a prevalent and economically significant disease in dairy cattle, leading to reduced milk production and quality. Staphylococcus aureus is a major causative agent of bovine mastitis, often complicating treatment due to its ability to develop antibiotic resistance. This resistance is frequently mediated by efflux pumps, such as the NorA pump. The aim of this study was to investigate the potential of Zataria multiflora essential oil (EO) to inhibit biofilm formation and disrupt the NorA efflux pump in ciprofloxacin-resistant S. aureus isolates from bovine mastitis.The plant EO was extracted using the hydrodistillation method, and its composition was determined by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The antibacterial and anti-biofilm activities of the EO were assessed against 7 clinical ciprofloxacin-resistant S. aureus isolates from bovine mastitis. The NorA efflux pump inhibitory (EPI) potential of the EO was assessed using the checkerboard assay against S. aureus norA overexpressed (SA1199B strain) and clinical isolates. Then, the expression of the norA gene at sub-minimum inhibitory (sub-MICs) concentrations levels was also determined. Finally, the cytotoxicity of the Z. multiflora essential oil was assessed using the MTT assay on the Vero cell line. The potent antibacterial activity of Z. multiflora EO against clinical and standard strains was found, with MIC values ranging from 0.25 to 64µg.ml- 1. The tested EO demonstrated significant anti-biofilm activity at MIC/2 and MIC/4 concentrations. In all clinical and norA overexpressed strains, Z. multiflora EO had a total or partial synergistic effects with ciprofloxacin and ethidium bromide with fractional inhibitory concentration index (FICI) < 2, indicating EPI activity. At MIC/2 and MIC/4 concentrations, Z. multiflora EO significantly downregulated the norA gene (P < 0.01). Z. multiflora EO showed no significant cytotoxicity towards human cells at MIC and 2MIC concentrations. In conclusion, Zataria multiflora EO exhibited promising antibacterial, anti-biofilm and EPI properties against ciprofloxacin-resistant S. aureus isolated from bovine mastitis. Moreover, it showed no significant cytotoxicity towards mammalian cells, suggesting its potential as a safe and effective therapeutic agent for bovine mastitis. Further investigations are warranted to explore its efficacy in vivo.

Molecular mechanisms of heavy metal resistance and cross-/co-resistance to antibiotics in Pseudomonas aeruginosa.

Heavy metal pollution is a growing environmental and public health concern, particularly due to its impact on microbial communities. Pseudomonas aeruginosa, a highly adaptable bacterium, has developed resistance to heavy metals (HMs), which is closely linked to antibiotic resistance through shared genetic and regulatory pathways. This co-resistance poses significant challenges for environmental health and antimicrobial management. Additionally, microplastics act as carriers for HMs and antibiotics, creating a compounded pollution stressor that further influences bacterial resistance patterns. This review explores the molecular mechanisms by which P. aeruginosa resists heavy metal toxicity, focusing on key adaptive strategies such as efflux systems, biofilm formation, enzymatic detoxification, and genetic modifications. These mechanisms enhance bacterial survival in contaminated environments, allowing P. aeruginosa to persist and contribute to the spread of resistance genes. The interplay between HMs, antibiotics, and microplastics underscores the complexity of pollution-driven bacterial adaptation. Addressing these issues requires a multidisciplinary approach that integrates environmental pollution control and antimicrobial resistance management. Understanding how P. aeruginosa thrives under such stress conditions is crucial for developing effective strategies to mitigate the risks associated with heavy metal contamination, antibiotic resistance, and microplastic pollution in both natural and clinical ecosystems.

A virulent phage vB_VpaP_R28Z infecting Vibrio parahaemolyticus with potential for therapeutic application

BackgroundVibrio parahaemolyticus, a major foodborne pathogen, contaminates aquatic products and causes significant economic losses in aquaculture while threatening food security and public health. Given the rising prevalence of multidrug-resistant V. parahaemolyticus strains, phage therapy has emerged as an effective and environmentally sustainable alternative for controlling vibriosis in aquaculture. In this study, a virulent bacteriophage, vB_VpaP_R28Z (R28Z), which infects V. parahaemolyticus ATCC 17802T, was isolated and comprehensively characterized.ResultsR28Z was isolated from sewage collected at a seafood market in southern China and exhibits pronounced lytic properties against pathogenic Vibrio species prevalent in aquaculture environments, including Vibrio parahaemolyticus, Vibrio diabolicus, and Vibrio alginolyticus. Transmission electron microscopy (TEM) analysis revealed that R28Z belongs to the podophage morphotype. Genomic analysis indicated that R28Z is a double-stranded DNA phage with a genome size of 43,284 bp and a G + C content of 49.34%. Notably, no genes associated with lysogeny, virulence, or antibiotic resistance were detected in R28Z, suggesting its suitability for therapeutic applications. R28Z demonstrated high efficacy in lysing host cells, with a short latent period of less than 10 min and a large burst size of 113 ± 19 PFU/cell (average ± s.d.). Additionally, R28Z exhibited stability over a broad pH range of 4–10 and at temperatures ranging from 4 °C to 50 °C. Taxonomic assessments validated the novelty of R28Z, suggesting that it represents a new species of the Maculvirus genus and enriches the diversity of vibriophage candidates for therapeutic interventions against V. parahaemolyticus infections.ConclusionsThe newly discovered phage R28Z, characterized by its high lytic efficiency and environmental stability, represents a novel species as a potential alternative biocontrol agent for managing V. parahaemolyticus infections in aquaculture.

Current prospects of fluoroquinolones: pazufloxacin. A review

Fluoroquinolones (FQ) are one of the most valuable groups of antibacterial drugs in clinical practice. Ciprofloxacin and levofloxacin are drugs with the largest contribution to the structure of FQ consumption both in the Russian Federation and in the world. The widespread use of FQ in recent years has been accompanied by an intensive growth of antibiotic resistance of the main pathogens, including those from the ESKAPE group, which limits the possibilities of effective antibiotic therapy for a wide range of infectious diseases. In this situation, we have an attractive possibility of including a new FQ for the Russian pharmaceutical market, pazufloxacin, in the treatment regimens for patients with infectious diseases. This is a third-generation FQ, whose spectrum of antibacterial action, as has been demonstrated in the published studies, is close to that of the beta-lactam ABP ceftazidime. The studies considered in our narrative review indicate a high level of clinical efficacy and safety of this FQ, which suggests broad prospects for its use in the treatment of infectious diseases taking in account accelerated antibiotic resistance.

Efficacy of phage vB_Ps_ZCPS13 in controlling Pan-drug-resistant Pseudomonas aeruginosa from urinary tract infections (UTIs) and eradicating biofilms from urinary catheters

BackgroundPan-drug resistance (PDR) is a ticking time bomb, as it causes high human hospitalizations and mortality rates. For instance, Pseudomonas aeruginosa is associated with significant rates of urinary tract infections (UTIs) due to several reasons including antibiotic resistance, biofilm formation and the presence of various virulence factors. Consequently, there is an urgent need for safe and effective alternative antibacterials. Phage therapy is a promising alternative that uses naturally occurring bacteriophages (phages). Therefore, our present study investigated the isolation and characterization of a novel virulent phage (vB_Ps_ZCPS13) against the PDR Pseudomonas aeruginosa strain (Ps13).MethodsPhage vB_Ps_ZCPS13 was isolated from raw sewage water in Egypt during the springtime. The isolated phage was purified and amplified, followed by estimating its purity and genome size using pulsed-field gel electrophoresis (PFGE), morphology using transmission electron microscopy (TEM), antibacterial activity against other P. aeruginosa hosts, physiochemical stability studies, whole genome sequencing, antibiofilm activity on urinary catheters using scanning electron microscopy (SEM), and cytotoxicity assays against normal human skin fibroblast (HSF) cell lines.ResultsBased on vB_Ps_ZCPS13 morphology under TEM, the phage has been classified as a myovirus. In consistent with the PFGE results, DNA sequencing revealed a phage genome size of 92,443 bp, with lytic-associated genes and no antimicrobial resistance or virulence factors. Phage vB_Ps_ZCPS13 presented a wide host range of over 93% of tested clinical isolates having different multiple antibiotic resistance (MAR) indices. Furthermore, phage vB_Ps_ZCPS13 exhibited high efficiency in plaque formation (EOP ≥ 1) against 13% of the strains and exhibited low frequencies of bacteriophage insensitive mutants (BIM). The physical stability test against harsh environmental conditions revealed phage stability within a pH range of 3.0–11.0 and stable at temperatures below 70 °C. Phage vB_Ps_ZCPS13 also exposed a significant antibacterial activity in vitro across different MOIs, with the highest reduction in bacterial growth observed at lower MOIs. Furthermore, vB_Ps_ZCPS13 demonstrated potent biofilm inhibition and clearance capabilities, effectively eradicating P. aeruginosa from the urinary catheter surface. Moreover, the phage presented no cytotoxicity against normal human skin fibroblast (HSF) cell lines at high titer.ConclusionsOur study offers an effective phage as a therapeutic candidate against PDR Gram-negative P. aeruginosa infections, including catheter-associated urinary tract infections.

Genetic Diversity of Selected Antibiotic Resistant Bacterial Strains from Industrial Effluents in Nairobi County, Kenya

Antibiotic resistance represents a critical global health challenge driven by the dissemination of resistant bacterial genes across households, livestock and environmental reservoirs. Horizontal gene transfer and mutations play substantial roles in the existence and persistence of antimicrobial resistance significantly diminishing the effectiveness of current antibiotic therapies. This study aimed to investigate the genotypic and phenotypic resistance profiles of bacterial strains isolated from industrial effluent samples. Conducted in Nairobi County, Kenya, between January and December 2024, the study involved analysis of four bacterial strains isolated from industrial effluent samples collected via systematic sampling across multiple industrial sites. Bacterial identification was performed using API® 20E biochemical identification kit (BioMérieux, France). Antibiotic susceptibility testing encompassed several antibiotic classes including cephalosporins, penicillins, aminoglycosides, sulfonamides, tetracyclines, fluoroquinolones and carbapenems. DNA extraction from antibiotic-resistant isolates was conducted using ZyppyTM Plasmid Miniprep Kit (Zymo Research, USA) following the manufacturer’s protocol. Conventional PCR assays targeted resistance genes bla-TEM, bla-OXA, bla-KPC-1, bla-NDM and ParC. Sequence alignment was performed using MUSCLE software while phylogenetic analyses were conducted with MEGA 11 employing the Maximum Likelihood method to infer evolutionary relationships. All tested bacterial isolates including Pseudomonas aeruginosa, Escherichia coli, Aeromonas spp., Klebsiella pneumoniae, and Bacillus spp., exhibited 100% resistance to penicillin. Resistance to tetracyclines, cephalosporins and sulfonamides was notably prevalent in Aeromonas spp. In contrast, carbapenems and aminoglycosides maintained substantial efficacy particularly against Aeromonas spp. and Pseudomonas aeruginosa strains. Multiplex PCR analysis revealed widespread distribution of resistance genes with bla-TEM being the most prevalent followed by bla-KPC, bla-OXA, bla-NDM and ParC underscoring the molecular basis for the observed resistance phenotypes. Phylogenetic analysis demonstrated high sequence homology with globally distributed pathogenic strains highlighting the clinical relevance and potential public health impact of these findings. These findings underscore the urgent need to integrate comprehensive surveillance systems and implement multifaceted antimicrobial strategies to curb the spread of multidrug-resistant bacterial strains across environmental, healthcare, and aquatic ecosystems.

Mobile genetic elements mediating antimicrobial resistance drive the evolutionary process of Clostridioides difficile ST37/RT017

BackgroundClostridioides difficile (C. difficile) ST37/RT017 is one of the most prevalent genotypes, exhibiting resistance to multiple antimicrobial agents and widespread dissemination, particularly in East Asia. However, its evolutionary history and genetic adaptation remains limited. Here, we aimed to systematically assess the genetic diversity, key evolutionary events, and potential driving forces of C. difficile ST37/RT017.ResultsTo explored dynamic trends in the genomic characterization, diversity and changes, both phylogenetic and Bayesian evolutionary analyses revealed that the C. difficile ST37/RT017 strains were clustered into three variant lineages as a directed bus-like topology, from VL I, to VL II, and VL III. An incremental increase in the median number of resistance genes was observed, with one in VL I, five in VL II, and six in VL III. Distinguishing features included variations in resistance genes or fluoroquinolone resistance mutation, such as erm(B), tet(M), aac(6’)-Ie-aph(2’’)-Ia, ant(6)-Ia and gyrA (T82I). Further analysis of evolutionary mechanisms revealed that Tn916, carrying tet(M), was present in 87.9% (160/182) of VL III and 92.6% (163/176) of VL II, but only 4.1% (5/122) of VL I. The Tn6194-like element, carrying erm(B), was found in 25.3% (46/182) of VL II and 84.7% (149/176) of VL III, with none detected in VL I. Furthermore, other functional genes, especially srtB, were notable in C. difficile ST37/RT017, which gradually acquired resistance genes from VL I to VL II and VL III.ConclusionsThe systematically analysis in this study suggests that the acquisition of antibiotic resistance genes was the primary driver of adaptive evolution in C. difficile ST37/RT017. Horizontal gene transfer, particularly through mobile genetic elements is a key genetic mechanism in the adaptive evolution of C. difficile ST37/RT017. Based on these genetic profiles, the active establishment and optimization of a rational system for antibiotic use will be crucial to prevent the emergence of a C. difficile ST37/RT017 variant.

Comprehensive review of selected traditional medicinal plants used by Jambi local communities as potential antibacterial agents

The increasing antibiotic resistance in bacteria leads to the urgent need for alternative antibacterial agents. The discovery of potential antibacterial agents in plants has been conducted according to the information about traditional medicines used by communities and the local wisdom passed down from generations. Jambi local communities in Indonesia used traditional concoctions from various medicinal plants to treat diseases caused by pathogenic bacteria, such as skin infections, abscesses, diarrhea and mouth ulcers. Prominent medicinal plants widely used by Jambi local communities include Calamus manan, Helminthostachys zeylanica and Zingiber montanum. This comprehensive review examines the traditional uses, phytochemistry and antibacterial activity of selected Jambi medicinal plants. Furthermore, this review highlights the significant contributions and current updates in this research area surrounding the ethnobotany, phytochemistry and pharmacology of medicinal plants in Jambi. However, this review also emphasizes the need for further research due to the preliminary results of current updates, such as compound isolation and purification and the antibacterial mechanism of actions of those compounds. In conclusion, the current phytochemical and pharmacological studies supported the traditional use of Jambi medicinal plants and confirmed its efficacy significantly. This review aims to support the future development of antibacterial agents from medicinal plants.

Antibiotic-resistant Escherichia coli and Associated Risk Factors in Dialysis Patients with Urinary Tract Infections in the Bamenda Health District: A Comparative Analysis with Non-dialytic Participants

Background: Urinary tract infections are a public health problem affecting all individuals. However, its impact on patients with kidney failure needs to be determined. The main aim of this research was to investigate the prevalence and antibiotic-resistant pattern of Escherichia coli causing urinary tract infection in patients on dialysis and non-dialyzing participants in the Bamenda Health District. Methods: This was a cross-sectional study conducted from January to June 2024, and involved collection of urine samples from dialytic (45) and non-dialytic (59) participants. The urine samples were cultured on Cysteine-Lactose-Electrolyte-Deficient agar and MacConkey agar. Positive cultures typical of E. coli were identified using API20E. Antibiotic susceptibility testing was done using Kirby-Bauer Disc diffusion method. The data was analysed using the Statistical Package for Social Sciences software. Results: The age of the participants ranged from 17 to 78 years with a mean (std) age of 37.95(10.86) years. The prevalence of E. coli was 25% (26/104) and was insignificantly (p = 0.732) higher in patients on dialysis (26.7%) than in non-dialyzing participants (23.7%). All isolates were resistant to two or more antibiotics. Drug resistance was highest with ofloxacin (83.3%) and ciprofloxacin (77.8%) in dialysis patients while nitrofurantoin was the most active drug (19; 73.08%). Multidrug resistance was recorded in 18 (69.2%) of the isolates and was significantly higher (p=0.011) in patients on dialysis 12(92.3%). The age groups of less than 30 years (AOR; 0.042, p=0.000] and 30-40 years (AOR; 0.120, p=0.01) and being on dialysis (AOR 5.488, p=0.017) were identified as risk factors for antibiotic resistance. Conclusion: This study showed that the prevalence of drug resistance is high and there is need for policy makers to establish policies for the prudent use of antibiotics in dialysis units.