The emergence of multidrug-resistant bacteria poses a significant threat to global public health, highlighting the urgent need for novel, effective, and safe alternative agents to combat these pathogens. This study aimed to evaluate the in vitro antibacterial activity and mechanism of action of Galla chinensis extract (GCE) against porcine-origin Staphylococcus aureus. The bioactive components of Galla chinensis were extracted by water extraction with water-bath heating. The minimum inhibitory concentration (MIC) was determined using the two-fold broth microdilution method. The in vitro antibacterial activity of the GCE extract against S. aureus was evaluated by the disk diffusion assay and by monitoring bacterial growth curves at various extract concentrations. The antibacterial mechanism was investigated by assessing key indicators of bacterial membrane and envelope integrity following exposure to the extract. The GCE exhibited potent inhibitory activity against S. aureus, with an inhibition zone diameter of 3.60 ± 0.10 cm. The MIC of GCE against S. aureus was 15.63 mg/mL. Compared with the control group, bacterial growth was markedly suppressed in the extract-treated groups in a dose-dependent manner, with the inhibitory effect strengthening as the extract concentration increased. Following treatment, the alkaline phosphatase (AKP) activity, soluble protein concentration, and extracellular nucleic acid leakage of S. aureus increased in a concentration-dependent manner. Galla chinensis exhibits potent in vitro antibacterial activity against S. aureus by inhibiting bacterial growth, and its underlying mechanism is associated with disrupting the cell wall and cell membrane integrity of S. aureus.

The emergence of carbapenem- and colistin-resistant Enterobacterales mediated by transmissible plasmids poses a critical One Health threat by compromising the efficacy of last-resort antimicrobials. We characterized a commensal Escherichia coli ST156 isolate recovered from a clinically healthy companion dog in South Korea that carried blaNDM-5 and mcr-1 on distinct plasmids. Antimicrobial susceptibility testing revealed a multidrug-resistant phenotype, including resistance to carbapenems (imipenem MIC, ≥8 μg/mL) and colistin (MIC, 8 μg/mL). Hybrid long- and short-read genome assembly localized blaNDM-5 to an IncX3 plasmid and mcr-1 to an IncX4 plasmid. Broth-mating assays showed that each plasmid was independently transferable under the corresponding single-antimicrobial selection. Among 30 transconjugant colonies screened under each selection, both resistance determinants were detected in five colistin-selected and two meropenem-selected colonies, indicating co-detection of both resistance determinants in a minority of the screened colonies. Comparative genomic analysis showed that the IncX4-mcr-1 plasmid shared a highly conserved backbone with globally distributed IncX4 plasmids from diverse sources. These findings demonstrate asymptomatic carriage of independently transferable carbapenem- and colistin-resistance plasmids in a companion animal and support the inclusion of companion animals in integrated antimicrobial resistance surveillance.

Antimicrobial resistance (AMR) was exacerbated by COVID-19 pandemic. This study describes prevalence and trends of AMR in patients with diagnosed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection admitted during 2020-2022 to the intensive care unit (ICU) in Molise region, central Italy. A retrospective study was conducted, including patients aged ≥ 18 years with at least one positive bacterial or fungal culture during ICU stay. Data were related to patient demographics, ICU outcomes, healthcare-associated infections, and antimicrobial susceptibility profiles. During the 2020-2022 period, 103 ICU admissions met the inclusion criteria, yielding 268 isolations, of which 157 underwent antimicrobial susceptibility testing. Apart from high proportion of Candida albicans, Gram-negative bacteria predominated, with Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii among the most frequent. Resistance to beta-lactams and carbapenems was consistently high, while it ranged from 53.8% to 66.7% to fluoroquinolones and remained above 50% to aminoglycosides. Tetracycline resistance showed significant year-to-year variation, increasing in 2022 compared with both 2020 and 2021. AMR rates in COVID-19 patients in ICU were persistently high throughout the pandemic, with critical resistance levels in Gram-negatives, underlining the need to reinforce infection prevention and control measures and antimicrobial stewardship programs and align prescribing practices with World Health Organization AWaRe recommendations, even during public health emergencies.

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (M.TB) infection. Although there have been significant advances in the treatment of M.TB infection, it still faces significant challenges. The gut microbiota is a highly complex ecosystem that plays an important role in regulating metabolism, immune regulation, and maintaining healthy balance in the human body. More and more studies have found that while gut microbiota regulates the immune regulation process of pulmonary TB through the "gut-lung axis," infection with M.TB can also affect the microbial stability of gut microbiota, thereby affecting host health. This article summarized and discussed the changes of gut flora in TB patients, the possible relationship and impact between gut flora and M.TB infection, and summarized and looked forward to the potential of gut flora in the treatment of TB, in order to provide a reference for the prevention and treatment of gut microorganisms in anti-M.TB infection.

Fosfomycin is a highest priority critically important antimicrobial in medical settings and is approved for use in cattle, fish, and humans in Japan. Breakpoints for fosfomycin differ between the antimicrobial susceptibility test guidelines of the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Although important for public health, information on the prevalence of fosfomycin-resistant bacteria and mobile fosfomycin resistance genes (fos) in bacteria of nonhuman origin remains insufficient. In this study, we investigated Escherichia coli strains isolated from animals (cattle, pigs, chickens, and dogs) and the association of these with environments in Japan to determine the prevalence of fosfomycin-resistant E. coli based on CLSI and EUCAST, as well as fos gene prevalence. Susceptibility testing for fosfomycin was retrospectively conducted in 2,057 E. coli, and fos genes were detected in fosfomycin-resistant E. coli. Whole-genome sequencing of fos-positive E. coli was performed. The resistance rates to fosfomycin according to CLSI and EUCAST guidelines were 0.6% and 11.7%, respectively. The fosA3 gene was detected in three E. coli isolates (from one cow and two dogs) in Japan. Two fosA3-positive strains harbored the blaCTX-M-14 or blaCTX-M-65 gene located on the same plasmids. The genetic structures of fosA3-carrying plasmids were almost identical to those reported in Japan and China. Herein, we report the prevalence of fosfomycin resistance in Japan, including fosfomycin-nonapproved fields, showing that these may serve as reservoirs of fosfomycin-resistant bacteria and fos genes carried on globally disseminated mobile genetic elements.

Enterobacterales bloodstream infections (E-BSIs) in intensive care units (ICUs) are increasingly complicated by antimicrobial resistance. This retrospective study evaluated resistance patterns and phenotype-specific risk factors for extended-spectrum β-lactamase (ESBL) production and carbapenem and colistin resistance in 314 adult ICU patients with monomicrobial E-BSI admitted to a tertiary care hospital in Türkiye between September 2019 and 2022. Resistance rates were calculated using evaluable isolates, and independent risk factors were identified by multivariable logistic regression. ESBL positivity was detected in 179 of 312 isolates (57.4%), phenotypic carbapenem resistance in 84 of 311 (27.0%), and colistin resistance in 100 of 272 isolates (36.7%). Compared with antibiotic-susceptible patients, those with at least one resistance phenotype had a longer admission-to-blood-culture interval and more frequent prior antibiotic exposure. Admission-to-blood-culture interval, malignancy, and purulent endotracheal secretions were independently associated with ESBL positivity; respiratory failure and tigecycline use within the previous 3 months were independently associated with colistin resistance; and central nervous system disease and hemodialysis were independently associated with carbapenem resistance. ICU-associated E-BSI exhibited substantial antimicrobial resistance, with distinct phenotype-specific risk profiles supporting early risk stratification and targeted antimicrobial stewardship interventions.

France issued recommendations to control the spread of carbapenemase-producing Enterobacteriaceae (CPE) in 2013. We describe our experience with the implementation of national CPE screening guidelines in a French public hospital and its impact on CPE detection. Rapid PCR for CPE screening in our hospital began in 2014. Patients at-risk of CPE carriage are screened upon hospital admission. Rectal swab samples are tested either by PCR seven days/week or culture six days/week. The number of screening-detected CPE carriers increased from 2014 (n = 5) to 2025 (n = 138) and substantially increased in 2017 (n = 20) when primary screening of contact patients by rapid PCR was implemented. In 2022, 1,388 screenings by rapid PCR for 926 patients were performed, 37 of whom were positive, and 1,654 screenings by culture for 1,059 patients were performed, 50 of whom were positive. Screenings and positive results approximately tripled by 2025. There were 1-8 epidemics/year until 2022; each epidemic had 1 to 2 secondary cases. Two epidemics in 2023 were difficult to manage, possibly caused by reduced compliance with CPE procedures. Twelve years of CPE screening with rapid PCR in accordance with French guidelines has allowed Valenciennes hospital to limit CPE epidemics, although compliance by hospital personnel to CPE precautions has proved challenging. Our success at detecting CPE and minimizing epidemics through the implementation of national screening guidelines can serve as a model for other French public hospitals.

The genus Providencia and Morganella are part of the World Health Organization (WHO) critical priority pathogens when carbapenem-resistant. This study characterized the molecular epidemiology of carbapenemase genes in 13 clinical isolates of carbapenem-resistant Providencia spp. and Morganella morganii from a Brazilian tertiary hospital. Following species confirmation by MALDI-TOF MS, one of the isolates was reclassified as M. morganii. PCR and amplicon sequencing screened for blaKPC, blaNDM, blaVIM, blaIMP, blaGES, and blaOXA-23, -24, -48-LIKE, -51, -58, -143. The blaNDM (11/13, 84.6%) and blaKPC (4/13, 30.8%) were the only carbapenemase genes detected. All isolates tested negative for blaVIM, blaIMP, blaGES, and OXA-type genes. blaNDM-5 was identified in one P. rettgeri and one M. morganii (first reports in Brazil). blaKPC-2/blaNDM-1co-occurrence was documented in two P. stuartii isolates. Clinical analysis of blaNDM-5carriers revealed severe outcomes: one patient self-discharged without targeted therapy, and another died following amputation, extensive antimicrobial exposure, and COVID-19 co-infection. The accumulation of co-expressed resistance mechanisms highlights Providencia spp. and M. morganii as emerging therapeutic challenges.

Pseudomonas asiaticais an emerging opportunistic pathogen with a broad host range. Current evidence suggests that some isolates exhibit multidrug resistance, which may complicate treatment. In this study, a multidrug-resistant P. asiatica strain MD9 was isolated from aquaculture water. We aimed to characterize its complete genome sequence and investigate the role of its conjugative megaplasmid pMD9A in the horizontal transfer of antibiotic resistance genes. The genome of MD9 consists of one circular chromosome (5,956,782 bp, with a G + C content of 62.5%) and one circular megaplasmid, pMD9A (455,169 bp, with a G + C content of 56.5%). Genome annotation identified 65 antibiotic resistance genes and 148 putative virulence factor-encoding genes in the MD9 genome. The megaplasmid pMD9A carries 29 antibiotic resistance genes conferring resistance to β-lactams, chloramphenicol/florfenicol, aminoglycosides, and macrolides. A class 1 integron (intI1) and multiple autonomous conjugative transfer elements were identified in pMD9A. Conjugation experiments demonstrated that the β-lactam resistance gene blaOXA-246 could be horizontally transferred from the donor MD9 strain to the recipient Escherichia coli 25DN strain. The megaplasmid pMD9A not only carries a broad array of antibiotic resistance genes, but also facilitates their horizontal spread among environmental bacteria, thereby potentially contributing to the dissemination of multidrug-resistant bacteria.

The objective of this study was to analyze longitudinal trends in the detection rates of Carbapenem-resistant Gram-negative bacilli (CRGNB) in China from 2014 to 2024, and to forecast their evolution over the subsequent five years. Surveillance data were extracted from the annual reports of the China Antimicrobial Resistance Surveillance System (CARSS). In the period between 2014 and 2024, carbapenem-resistant Acinetobacter baumannii (CRAB) was identified with the highest frequency (range: 52.20%-60.00%), followed by carbapenem-resistant Pseudomonas aeruginosa (CRPA) (16.00%-25.60%), carbapenem-resistant Klebsiella pneumoniae (CRKP) (6.40%-11.30%), and carbapenem-resistant Escherichia coli (CREC) (1.50%-1.90%). Joinpoint analysis revealed a significant overall decreasing trend for CRPA (Average Annual Percentage Change, AAPC = -4.64%) and CRAB (AAPC = -1.05%). CRKP demonstrated a significant overall increase (AAPC = 4.29%), characterized by a sharp rise from 2014 to 2019 (Annual Percentage Change, APC = 10.73%, p < 0.01) followed by a plateau and nonsignificant decline (APC = -1.77%, p = 0.31). CREC exhibited a non-significant decreasing trend (AAPC = -1.42%, p = 0.16). The Autoregressive Integrated Moving Average (ARIMA) models, which were fitted to the data, demonstrated excellent predictive accuracy. Projections for 2025 indicate detection rates of 1.61% for CREC, 9.63% for CRKP, 14.25% for CRPA, and 52.39% for CRAB. Projections indicate a persistent downward trajectory over the ensuing five-year period, thereby substantiating the ongoing necessity for antimicrobial stewardship and surveillance initiatives.

Pseudomonas aeruginosa is a notorious opportunistic pathogen constituting a major cause of health care-associated infections worldwide. Intrinsic resistance to multiple antibiotics, with acquired resistance mechanisms and hypervirulence make it a critical target for genomic investigations. In this study, we investigated AMR determinants and virulence factors using WGS among five extensively drug-resistant (XDR) clinical P. aeruginosa isolates. XDR P. aeruginosa isolates isolated from bile, broncho-alveolar lavage and wound swabs were included in the study. Initially, the isolates were tested for the carbapenemase phenotype and genotype using modified Hodge test and PCR, respectively, followed by WGS. All isolates exhibited resistance to >50% of the antibiotics tested. Conventional PCR analysis identified blaNDM-1, blaOXA-48, and blaVIM invariably in the test isolates. Tested isolates were assigned sequence types as ST357 (n = 2), ST773, ST1047, and ST3043. WGS identified multiple resistant genes including blaOXA-488 and blaVIM-11(P2356), blaOXA-10, blaVIM-2, blaOXA-395 and blaOXA50 (PM381), blaVEB-9, blaOXA-50 and blaNDM-1 (PR90), blaOXA-485 (PR126), and blaOXA-50 (PR64). Notably, all the isolates were carrying different variants of blaPDC. The genomes were also associated with the virulence determinants, with genes encoding alginate and biofilm synthesis, quorum sensing, secretion systems, secondary metabolites, lipopolysaccharides, exotoxins, pili, and flagellar structure. All clinical P. aeruginosa isolates exhibited extensive resistance and virulence gene repertoires, also enriched with efflux pumps. Sequence types ST3043 and ST1047 are reported for the first time in India, underscoring the need for continuous genomic surveillance to monitor the emergence and dissemination of high-risk clones.

Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) are significant problems, especially in intensive care units (ICUs). We evaluated HAI rates, causative pathogens, resistance profiles, and antibiotic consumption retrospectively in a tertiary ICU across three 2-year periods-pre-pandemic period (PreP), pandemic period (PanP), and post-pandemic period (PostP)-to assess the impact of the COVID-19 pandemic. Antibiotic consumption was expressed as defined daily dose (DDD) per 1,000 patient days. The highest infection incidence rate and density were in PanP. Despite lower invasive device use, PanP had a higher rate of catheter-related bloodstream infections (BSIs). The most frequent pathogen across periods was Acinetobacter spp., although its rate declined in PostP. Gram-negative bacteria resistance rates to piperacillin-tazobactam, carbapenem, and aminoglycoside were highest in PanP. Resistant pathogen and resistant infection rates were lower in PostP, and resistant infections were less frequent in PostP than in PanP (OR: 0.371; 95% CI: 0.216-0.637; p < 0.001). Healthcare-associated pneumonia (HAP) was associated with a higher risk of resistance compared with BSI (OR: 3.467; 95% CI: 2.139-5.621; p < 0.001). Total antibiotic consumption remained comparable between PreP and PanP but increased in PostP. During the PanP, carbapenem use increased while piperacillin-tazobactam consumption decreased, whereas glycopeptide use increased and reached its highest level in PostP. Pandemic-related disruptions in the health care system may have contributed to increases in HAI and AMR rates, whereas improvements in the PostP may have supported recovery. Continuous surveillance, infection prevention measures, and antimicrobial stewardship programs are essential to mitigate the impact of future health care crises.