Dietary zinc supplementation inhibits bacterial plasmid conjugation in vitro by regulating plasmid replication (rep) and transfer (tra) genes.

Humans use dietary supplements for several intended effects, such as supplementing malnutrition. While these compounds have been developed for host end benefits, their ancillary impact on the gut microbiota remains unclear. The human gut has been proposed as a reservoir for the prevalent lateral transfer of antimicrobial resistance and virulence genes in bacteria through plasmid conjugation. Here, we studied the effect of dietary zinc supplements on the incidence of plasmid conjugation in vitro. Supplement effects were analyzed through standardized broth conjugation assays. The avian pathogenic Escherichia coli (APEC) strain APEC-O2-211 was a donor of the multidrug resistance plasmid pAPEC-O2-211A-ColV, and the human commensal isolate E. coli HS-4 was the plasmid-free recipient. Bacterial strains were standardized and mixed 1:1 and supplemented 1:10 with water, or zinc derived from either commercial zinc supplements or zinc gluconate reagent at varying concentrations. We observed a significant reduction in donors, recipients, and transconjugant populations in conjugations supplemented with zinc, with a dose-dependent relationship. Additionally, we observed a significant reduction (P < 0.05) in log conjugation efficiency in zinc-treated reactions. Upregulation of the mRNA for the plasmid replication initiation gene repA and the subset of transfer genes M, J, E, K, B, P, C, W, U, N, F, Q, D, I, and X was observed. Furthermore, we observed a downregulation of the conjugal propilin gene traA and the entry exclusion gene traS. This study demonstrates the effect of dietary zinc supplements on the conjugal transfer of a multidrug resistance plasmid between pathogenic and commensal bacteria during in vitro conditions.IMPORTANCEThis study identifies dietary zinc supplementation as a potential novel intervention for mitigating the emergence of multidrug resistance in bacteria, thus preventing antibiotic treatment failure and death in patients and animals. Further studies are required to determine the applicability of this approach in an in vivo model.

Discovery of benzo[c]phenanthridine derivatives with potent activity against multidrug-resistant Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb), the pathogen responsible for tuberculosis (TB), is the leading cause of bacterial disease-related death worldwide. Current antibiotic regimens for the treatment of TB remain dated and suffer from long treatment times as well as the development of drug resistance. As such, the search for novel chemical modalities that have selective or potent anti-Mtb properties remains an urgent priority, particularly against multidrug-resistant (MDR) Mtb strains. Herein, we design and synthesize 35 novel benzo[c]phenanthridine derivatives (BPDs). The two most potent compounds, BPD-6 and BPD-9, accumulated within the bacterial cell and exhibited strong inhibitory activity (MIC90 ~2 to 10 µM) against multiple Mycobacterium strains while remaining inactive against a range of other Gram-negative and Gram-positive bacteria. BPD-6 and BPD-9 were also effective in reducing Mtb survival within infected macrophages, and BPD-9 reduced the burden of Mycobacterium bovis BCG in the lungs of infected mice. The two BPD compounds displayed comparable efficacy to rifampicin (RIF) against non-replicating Mtb (NR-Mtb). Importantly, BPD-6 and BPD-9 inhibited the growth of multiple MDR Mtb clinical isolates. Generation of BPD-9-resistant mutants identified the involvement of the Mmr efflux pump as an indirect resistance mechanism. The unique specificity of BPDs to Mycobacterium spp. and their efficacy against MDR Mtb isolates suggest a potential novel mechanism of action. The discovery of BPDs provides novel chemical scaffolds for anti-TB drug discovery.IMPORTANCEThe emergence of drug-resistant tuberculosis (TB) is a serious global health threat. There remains an urgent need to discover new antibiotics with unique mechanisms of action that are effective against drug-resistant Mycobacterium tuberculosis (Mtb). This study shows that novel semi-synthetic compounds can be derived from natural compounds to produce potent activity against Mtb. Importantly, the identified compounds have narrow spectrum activity against Mycobacterium species, including clinical multidrug-resistant (MDR) strains, are effective in infected macrophages and against non-replicating Mtb (NR-Mtb), and show anti-mycobacterial activity in mice. These new compounds provide promising chemical scaffolds to develop potent anti-Mtb drugs of the future.

The enhanced antibacterial and antibiofilm properties of titanium dioxide nanoparticles biosynthesized by multidrug-resistant Pseudomonas aeruginosa.

The emergence of Multidrug-resistant (MDR) bacteria are becoming a major worldwide health concern, encouraging the development effective alternatives to conventional antibiotics. The study identified P. aeruginosa and assessed its antimicrobial sensitivity using the Vitek-2 system. Carbapenem-resistant genes were detected through Polymerase chain reaction (PCR). MDR- P. aeruginosa isolates were used to biosynthesize titanium dioxide nanoparticles (TiO2NPs) and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM). A study involving 78 P. aeruginosa isolates revealed that 85.8% were MDR, with meropenem and amikacin showing effectiveness against 70% of the isolates. The most prevalent carbapenemase gene was blaOXA-48, present in 83% of the isolates. Majority of the isolates formed biofilms, and biosynthesized TiO2NPs were able to reduce biofilm formation by 94%. TiO2NPs exhibited potent antibacterial action against MDR-Gram-negative bacilli pathogens and showed synergistic activity with antibiotics, particularly piperacillin, with a significant fold increase in areas (283%). A new local strain of P. aeruginosa, identified as ON678251 in the World GenBank, was found capable of producing TiO2NPs. Our findings demonstrate the potential of biosynthesized TiO2NPs to manage antibiotic resistance and regulate the formation of biofilms. This presents a promising direction for the creation of novel antimicrobial agents or substitutes for use in clinical settings, particularly in the management of isolates capable of resisting multiple drugs.

Efficacy and safety of shorter multidrug-resistant or rifampicin-resistant tuberculosis regimens: a network meta-analysis.

BACKGROUND: Drug-resistant tuberculosis (DR-TB) remains a threat to public health. Shorter regimens have been proposed as potentially valuable treatments for multidrug or rifampicin resistant tuberculosis (MDR/RR-TB). We undertook a systematic review and network meta-analysis to evaluate the efficacy and safety of shorter MDR/RR-TB regimens. METHODS: We searched PubMed/MEDLINE, Cochrane Center for Clinical Trials (CENTRAL), Scopus, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, US Food and Drug Administration, and Chinese Clinical Trial Registry for primary articles published from 2013 to July 2023. Favorable (cured and treatment completed) and unfavorable (treatment failure, death, loss to follow-up, and culture conversion) outcomes were assessed as the main efficacy outcomes, while adverse events were assessed as the safety outcomes. The network meta-analysis was performed using R Studio version 4.3.1 and the Netmeta package. The study protocol adhered to the PRISMA-NMA guidelines and was registered in PROSPERO (CRD42023434050). RESULT: We included 11 eligible studies (4 randomized control trials and 7 cohorts) that enrolled 3,548 patients with MDR/RR-TB. Treatment with a 6-month combination of BdqLzdLfxZTrd/Eto/H had two times more favorable outcomes [RR 2.2 (95% CI 1.22, 4.13), P = 0.0094], followed by a 9-11 month combination of km/CmMfx/LfxPtoCfzZEHh [RR1.67 (95% CI 1.45, 1.92), P < 0.001] and a 6-month BdqPaLzdMfx [RR 1.64 (95% CI 1.24, 2.16), P < 0.0005] compared to the standard longer regimens. Treatment with 6 months of BdqPaLzdMfx [RR 0.33 (95% CI 0.2, 0.55), P < 0.0001] had a low risk of severe adverse events, followed by 6 months of BdqPaLzd [RR 0.36 (95% CI 0.22, 0.59), P ≤ 0.001] and BdqPaLzdCfz [RR 0.54 (95% CI 0.37, 0.80), P < 0.0001] than standard of care. CONCLUSION: Treatment of patients with RR/MDR-TB using shorter regimens of 6 months BdqLzdLfxZTrd/Eto/H, 9-11 months km/CmMfx/LfxPtoCfzZEHh, and 6 months BdqPaLzdMfx provides significantly higher cure and treatment completion rates compared to the standard longer MDR/RR-TB. However, 6BdqPaLzdMfx, 6BdqPaLzd, and 6BdqPaLzdCfz short regimens are significantly associated with decreased severity of adverse events. The findings are in support of the current WHO-recommended 6-month shorter regimens.

The Impact of Infection Control Policies on Hospital Acquired Infections by MDROs from 2016 to 2023.

Purpose: Hospital-acquired infections (HAIs) caused by multidrug-resistant organisms (MDROs) pose a significant challenge to healthcare systems. The present study aimed to evaluate the impact of the infection policy to COVID-19 on the incidence of HAIs caused by MDROs. Methods: We conducted an eight-years retrospective analysis at a hospital in Shanghai, China. Bloodstream, sputum, and urinary tract cultures of MDROs obtained 48h after admission were collected monthly from January 2016 to Dec 2023. Occupied bed days (OBDs) were used to generate monthly HAI incidences per 10,000 OBDs. The study period was divided into pre-control, in-control, and post-control cohorts, in January 2020 and January 2022. The incidence was compared using interrupted time-series regression. Results: In total, 6763 MDRO cultures were identified, comprising 1058 bloodstream, 4581 sputum, and 1124 urine cultures derived from 4549 patients. The incidence rates of all HAIs were 8.68 per 10,000 OBDs in the pre-control cohort, 9.76 per 10,000 OBDs in the in-control cohort and 12.58 per 10,000 OBDs in the post-control cohorts, respectively. A downward trend in the incidence of HAI was observed in the post-control cohort (p<0.05). Conclusion: This study demonstrates that while the COVID-19 pandemic poses a significant challenge to infection control within hospitals, it provides a unique opportunity to enhance infection control measures and evaluate their effectiveness. In addition, these findings highlight the need for more targeted prevention and control strategies against different pathogens in future epidemics.

BPaLM Regimen Against Drug-Resistant Tuberculosis in India: A Need of the Hour.

India has a high burden of drug-resistant tuberculosis (DR-TB) cases. The management of this severe form of TB is associated with a number of issues like long treatment durations, high pill burden, and multiple adverse drug reactions. Efforts are on through various research studies and trials for finding solutions to the issues linked to the current drug regimens against drug-resistant tuberculosis. One such remarkable development is the introduction of bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaLM)-based regimens to fight against two of the most severe forms of tuberculosis, i.e., multidrug- and extensively drug-resistant tuberculosis (MDR-TB and XDR-TB). This editorial throws light on this newer regimen and discusses the same in the Indian context.

Medical residents' knowledge, attitudes and practices regarding antibiotics, antimicrobial stewardship and multidrug-resistant bacteria: a cross-sectional study in a major university in Iran.

Background: Antimicrobial resistance (AMR) is one of the biggest threats to global public health systems. This study aimed to assess the knowledge, attitudes and practice about AMR, antimicrobial stewardship programs (ASPs) and multidrug-resistant (MDR) bacteria. Methods: A web-based questionnaire survey was conducted among the residents of Isfahan University of Medical Sciences from May to November 2023. Data analysis was done using SPSS version 24.0 software. Results: Overall, 400 out of 450 medical residents responded to the questionnaire, giving a response rate of 88.9%. The participants' ages ranged from 26 to 54 years, and the majority were female (227/400 56.8%). Average scores for knowledge, attitudes, and practices were 53.70 ± 15.88, 36.97 ± 5.89 and 24.69 ± 4.24, respectively. In terms of knowledge, only 26.8% had heard the term "ASPs" and knew what it was. Most incorrect answers appeared to the treatment of infection caused by MDR bacteria including ESBL-producing Escherichia coli (27.8%) and carbapenem-resistant Klebsiella pneumoniae (30.8%), as well as the atypical bacteria (45.5%). Approximately, 50 and 71.7% said they had received no specific training in the fields of microbiological sampling methods and the appropriate time to prescribe antibiotics, respectively. Surprisingly, regarding practice, 81.8% of the respondents stated that antibiotics are used to treat flu or the common cold. Conclusion: Residents considered their training on important issues including ASPs, MDR bacteria and the spectrum of antibiotics insufficient. This result highlights the need for targeted training interventions about antibiotic prescription in the curriculum at the university with more emphasis on ASPs to limit the development of resistance.

Multidrug-resistant tuberculosis of spine diagnosis and management: An institutional experience of 21 cases.

Background: We aimed to establish a standardized protocol for managing multidrug-resistant (MDR) spinal tuberculosis (TB), addressing the surgical options, ranging from computed tomography-guided biopsy to intraoperative sampling. Methods: This study developed a treatment/management protocol based on an analysis of clinical, radiological, and postoperative outcomes for 21 patients with spinal MDR-TB. Over 24 months, 21 patients with multidrug-resistant spinal TB underwent the following testing: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), numerical rating scale (NRS), and the American Spinal Injury Association Scale. Radiological criteria were based upon a comparison of preoperative and 6-month to 2-year postoperative plain radiographs. Results: The 21 patients underwent guided biopsies (35%) or intraoperative sampling (65%). For the surgical cases, dorsal vertebrae were most frequently involved (75%), and 90% underwent posterior surgical procedures. Postoperatively, ESR, CRP, kyphosis angle, and NRS score were significantly reduced. The 3 MDR patients who failed treatment were transitioned to the extensively drug-resistant (XDR) protocol wherein bedaquiline, linezolid, cycloserine, and clofazimine were given after drug sensitivity testing drug regimen, needed no further surgery, and none exhibited additional neurological deterioration. Conclusion: Regular clinical, laboratory, radiological, and outcome analysis is vital for following MDR spinal TB patients; early detection of relatively rare treatment failures (i.e., 3/21 patients in this series) allows for prompt initiation of XDR treatment, resulting in better outcomes.

The epidemiology and microbiology of central venous catheter related bloodstream infections among hemodialysis patients in the Philippines: a retrospective cohort study.

BACKGROUND: Despite efforts to improve the management of catheter-related bloodstream infections (CRBSI) in literature, temporary CVCs continue to be used for maintenance hemodialysis outside of acute care settings, particularly in the Philippines. METHODS: We conducted a retrospective cohort study to investigate the incidence, outcomes, risk factors, and microbiological patterns of CRBSI among adult kidney disease patients undergoing hemodialysis at the Philippine General Hospital, the country's largest tertiary referral center. We included all adult patients who received a CVC for hemodialysis from January 1, 2018, to August 31, 2019, and followed them for six months to observe the occurrence of CRBSI and its outcomes. RESULTS: Our study documented a CRBSI incidence rate of 6.72 episodes per 1000 catheter days, with a relapse rate of 5.08%, a reinfection rate of 15.74%, and a mortality rate of 6.09%. On multivariable regression analysis, we identified autoimmune disease, dialysis frequency of > 3 × per week, use of CVC for either blood transfusion or IV medications, renal hypoperfusion, drug-induced nephropathy, and hypertensive kidney disease as significant risk factors for CRBSI. Gram-negative bacteria, including B. cepacia complex, Enterobacter, and Acinetobacter spp, were the most common organisms causing CRBSI. Multidrug-resistant organisms (MDROs) comprised almost half of the isolates (n = 89, 44.5%), with Coagulase-negative Staphylococcus species having the highest proportion among gram-positive organisms and Acinetobacter spp. among gram-negative isolates. CONCLUSION: Our findings emphasize the need for more stringent measures and interventions to prevent the propagation of identified pathogens, such as a review of sterile technique and adequate hygiene practices, continued surveillance, and expedited placement and utilization of long-term access for patients on maintenance hemodialysis. Furthermore, CVC use outside of hemodialysis should be discouraged, and common antibiotic regimens such as piperacillin-tazobactam and fluoroquinolones should be reviewed for their low sensitivity patterns among gram-negative isolates. Addressing these issues can improve hemodialysis patients' outcomes and reduce the CRBSI burden in our institution.

Draft genome sequence analysis of multidrug-resistant Salmonella enterica subsp. enterica serovar Mbandaka harboring colistin resistance gene mcr-9.1 isolated from foals in Kentucky, USA.

Horses play a significant role in the direct or indirect transmission of Salmonella to humans. Here, we report the draft genomes of multidrug-resistant Salmonella enterica subsp. enterica serovar Mbandaka YAH-F68 isolated from foals in Kentucky, USA belonging to sequence type 413 and harboring the mobile colistin resistance gene mcr-9.1.

Quantification of MDR-TB drug JBD0131 and its metabolite in plasma via UPLC-MS/MS: application in first-in-human study.

Aim: JBD0131, a novel anti-multidrug-resistant tuberculosis (MDR-TB) drug, can target and inhibit the synthesis of mycolic acids, which are crucial components of the cell wall of the Mycobacterium tuberculosis complex. To support the results of this clinical trial in healthy subjects, development of a specific and accurate quantification method for detecting JBD0131 and its metabolite DM131 in human plasma is needed.Materials & methods: Samples with prior added stabilizer were pretreated by protein precipitation method and the extracts were subjected to ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The m/z transitions for the precursor/product ion pairs were 402.1/273 for JBD0131, 333.1/273 for DM131 and 386.1/257 for the internal standard (IS).Results: This method showed good linearity from 1 to 2000 ng/ml for JBD0131 and 0.25 to 500 ng/ml for DM131 and was validated in terms of selectivity, linearity, accuracy, precision, matrix effect, recovery of pretreament and stability.Conclusion: This method was sensitive and specific for measuring the plasma concentrations of JBD0131 and its metabolites. And it was applied for the investigation of the pharmacokinetics of JBD0131 and DM131 in a clinical trial.

[Box: see text].

Risk factors for multidrug-resistant bacteria in critically ill children and MDR score development.

Antimicrobial resistance and healthcare-associated infections (HAIs) are major health concerns in the pediatric intensive care unit (PICU). Device-associated HAIs (DA-HAIs) produced by multidrug-resistant (MDR) bacteria are especially worrying, as they can lead to an inappropriate empirical antibiotic therapy, worsened outcomes and increased mortality. The MDR score was designed to enable the prompt identification of patients at high risk of developing an MDR infection. This was a single-center, prospective, observational study, conducted between January 2015 and December 2022, including PICU patients with a microbiologically confirmed DA-HAI. Demographic, clinical characteristics and outcomes were compared between patients with a DA-HAI caused by MDR and non-MDR-associated DA-HAI, and a risk score for multi-resistance was designed. In total, 257 DA-HAI cases were included, 86 (33.46%) caused by an MDR microbe. In the univariate analysis, comorbidity (p = 0.002), previous MDR colonization (p < 0.001), previous surgery (p = 0.018), and previous antibiotic therapy (p = 0.009) were more frequent among MDR-associated DA-HAI (MDR DA-HAI). In addition, days from device insertion to infection and from PICU admission (p < 0.005) to infection were longer in patients with MDR. In the multivariate analysis, previous comorbidity (OR 2.201), previous MDR colonization (OR 5.149), and PICU length of stay longer than 9 days (OR 1.782) were independently associated with MDR-DA-HAI. Using these three independent risk factors for MDR, a risk score was created: the MDR score. Three risk groups were obtained: low risk (0-2 points), intermediate risk (3-7 points), and high risk (8-12 points). Seventy-one patients with MDR-DA-HAI (82.6%) were classified in the intermediate or high-risk group, with a global sensitivity of 82.6%. The specificity in the high-risk group was 91.8%, and 81.0% of patients who were stratified into the low-risk group had non-MDR-associated infections, so they were correctly classified. Conclusions: The MDR score can be a useful tool to stratify patients in risk groups for MDR-DA-HAI. It may help to guide the choice of empirical therapy, leading to early optimization and avoiding delays in establishing appropriate treatment. This study reinforces the importance of stratifying patients based on their individual risk profile for MDR infection.

Venetoclax for an ATRA and ATO resistance acute promyelocytic leukemia patient with TNRC18::RARA fusion gene.

Variant acute promyelocytic leukemia (APL) poses diagnostic and therapeutic challenges primarily because of the absence of PML::RARA. This report presents the case of a patient diagnosed with all-trans retinoic acid (ATRA)-resistant APL harboring the TNRC18::RARA fusion gene. After treatment with venetoclax, azacitidine, and ATRA, the patient achieved complete remission. The patient also developed pulmonary tuberculosis and a multidrug-resistant infection, which improved considerably after antituberculosis treatment and carrimycin, respectively.

Risk factors for multidrug-resistant tuberculosis: a predictive model study.

Objective: To investigate the risk factors associated with Multidrug-resistant tuberculosis (MDR-TB) in people with drug-resistant tuberculosis (DR-TB) and develop a predictive model. Methods: A total of 893 individuals with DR-TB treated at Wenzhou Central Hospital from January 2018 to December 2022 were included in the study after excluding 178 individuals with incomplete clinical and laboratory data, leaving 715 individuals for analysis. Data on demographic information, baseline clinical characteristics, laboratory and imaging results, and clinical diagnosis were collected to identify the risk factors for MDR-TB and establish a predictive model. Results: Multivariate logistic regression analysis identified residence in rural areas, retreatment of TB, presence of pulmonary cavity, uric acid (UA) ≥ 346 µmol/L and c-reactive protein (CRP) < 37.3 mg/L as independent risk factors for MDR-TB in individuals with DR-TB. A nomogram model was constructed using these five factors to predict the risk of MDR-TB, with an area under the ROC curve (AUC) of 0.758 for the training group and 0.775 for the validation group. Calibration curve analysis showed good agreement between predicted and actual MDR-TB incidence in both groups, and decision curve analysis showed that the nomogram model had a higher rate of clinical net benefit. Conclusion: This study suggests that residence, types of TB treatment, presence of pulmonary cavity, UA and CRP are associated with MDR-TB occurrence in individuals with DR-TB, and the nomogram model developed in this study shows promising predictive value.

A chitosan-modified tea tree oil self-nanoemulsion improves antibacterial effects in vivo and in vitro and promotes wound healing by influencing metabolic processes against multidrug-resistant bacterial infections.

Infectious diseases, especially multidrug-resistant bacterial infections, have caused crises and majorly disrupted public health and economic stability worldwide. Many natural essential oils, especially tea tree oil, have potential to treat multidrug-resistant bacteria, such as H. pylori and P. aeruginosa. However, there are some problems need to be solved, such as poor stability upon light or oxygen exposure. Therefore, it is urgent to develop the ideal formation to tackle these difficulties. Herein, we reported the novel chitosan-modified self-nanoemulsion (TNE) encapsulating natural essential tea tree oil with strong antibacterial and stability characterize. In this study, we found that this self-nanoemulsion (size: 212 nm, PDI: 0.124, zeta potential: -20.5 mV, 6 % tea tree oil) not only had physical properties, good stability and tissue safety, but also had better antibacterial synergism (2-8 times) than that of water suspension against various multidrug-resistant bacterial (such as H. pylori, MRSA and P. aeruginosa). Additionally, TNE showed high antibacterial effectiveness in vivo, reduced inflammation, promoted ulcer healing after H. pylori infection and accelerated wound healing after P. aeruginosa infection. Importantly, this novel self-nanoemulsion can induce 274 protein down-regulated and 251 protein up-regulated, and disrupt H. pylori metabolic processes (glyoxylate, dicarboxylic acid, glutamate and tryptophan metabolism) and reduced its viability, leading to significant synergistic antibacterial effects. TNE is a potential treatment for skin wounds or ulcers caused by multidrug-resistant bacterial infections.

Drug-resistance characteristics, genetic diversity, and transmission dynamics of multidrug-resistant or rifampicin-resistant Mycobacterium tuberculosis from 2019 to 2021 in Sichuan, China.

BACKGROUND: Multidrug- or rifampicin-resistant tuberculosis (TB; MDR/RR-TB) is a significant public health threat. However, the mechanisms involved in its transmission in Sichuan, China are unclear. To provide a scientific basis for MDR/RR-TB control and prevention, we investigated the drug-resistance characteristics, genetic diversity, and transmission dynamics and analyzed the demographic and clinical characteristics of patients to identify risk factors for the acquisition of MDR/RR-TB in Sichuan, Western China. METHODS: Whole-genome sequencing was performed using a sample comprised of all MDR/RR-TB strains isolated from patients with pulmonary TB (≥ 15 years) at the 22 surveillance sites in Sichuan province between January 2019 and December 2021, to analyze genotypic drug resistance and genetic diversity. Moreover, we performed statistical analyses of the epidemiological characteristics and risk factors associated with the transmission dynamics of MDR/RR-TB. RESULTS: The final analysis included 278 MDR/RR TB strains. Lineage 2.2, the major sub-lineage, accounted for 82.01% (228/278) of isolates, followed by lineage 4.5 (9.72%, 27/278), lineage 4.4 (6.83%, 19/278), and lineage 4.2 (1.44%, 4/278). The drug resistance rates, ranging from high to low, were as follows: isoniazid (229 [82.37%]), streptomycin (177 [63.67%]), ethambutol (144 [51.80%]), pyrazinamide (PZA, 119 [42.81%]), fluoroquinolones (FQs, 93 [33.45%]). Further, the clofazimine, bedaquiline, and delamanid resistance rates were 2.88, 2.88, and 1.04%, respectively. The gene composition cluster rate was 32.37% (90/278). In addition, 83.81% (233/278) of MDR/RR-TB cases were determined to be likely caused by transmission. Finally, patients infected with lineage two strains and strains with the KatG S315T amino acid substitution presented a higher risk of MDR/RR-TB transmission. CONCLUSION: Transmission plays a significant role in the MDR/RR-TB burden in Sichuan province, and lineage 2 strains and strains harboring KatG S315T have a high probability of transmission. Further, high levels of FQ and PZA drug resistance suggest an urgent need for drug susceptibility testing prior to designing therapeutic regimens. New anti-TB drugs need to be used standardly and TB strains should be regularly monitored for resistance to these drugs.

Combined nephrotoxicity of Polymyxins and Vancomycin: a study on adverse event reporting for monotherapy versus combinations using the FDA adverse event reporting system (FAERS).

BACKGROUND: Multidrug-resistant (MDR) infections pose a global public health crisis with significant mortality and economic burdens. Combination of polymyxins and vancomycin has shown effectiveness against MDR infections. However, their combined nephrotoxicity complicates clinical use. Given these concerns, we conducted a pharmacovigilance analysis using the FDA Adverse Event Reporting System (FAERS) to assess the nephrotoxicity of combinations of polymyxins and vancomycin compared to monotherapy. RESEARCH DESIGN AND METHODS: In this retrospective study, data from FAERS reports (2012 Q4 to 2023 Q2) were deduplicated and analyzed for adverse events (AEs) related to vancomycin, polymyxin B, and colistin. Disproportionality analyses were performed to evaluate the association between drugs and nephrotoxicity. RESULTS: A total of 9,796,784 adverse event reports, including 73,009 reports associated with nephrotoxicity, were included. All three drugs showed significant associations with nephrotoxicity. In combination therapy, polymyxin B-vancomycin exhibited a stronger association with nephrotoxicity compared to monotherapy, whereas colistin-vancomycin demonstrated a lower association with nephrotoxicity than colistin monotherapy. CONCLUSIONS: This study found that combining vancomycin with colistin alleviated colistin-induced nephrotoxicity, while combining vancomycin with polymyxin B worsened polymyxin B-induced nephrotoxicity.

Draft genome sequencing of multidrug-resistant Pseudomonas asiatica strains isolated from dairy cows with clinical mastitis and their farm environment.

We report, for the first time, the draft genomes of four multidrug-resistant Pseudomonas asiatica strains isolated from milk (2M1), feces (2F1 and 2F2), and farm soil (2S1) samples of dairy cows with clinical mastitis. The assembled genomes of these strains were 5.7 Mbp, 62.8% G + C content, and 50× genome coverage.

Advanced Palladium Nanosheet-Enhanced Phototherapy for Treating Wound Infection Caused by Multidrug-Resistant Bacteria.

With the increasing spread of multidrug-resistant (MDR) bacteria worldwide, it is needed to develop antibiotics-alternative strategies for the treatment of bacterial infections. This work develops a multifunctional single-component palladium nanosheet (PdNS) with broad-spectrum and highly effective bactericidal activity against MDR bacteria. PdNS exerts its endogenous nanoknife (mechanical cutting) effect and peroxidase-like activity independent of light. Under near-infrared region (NIR) light irradiation, PdNS exhibits photothermal effect to produce local heat and meanwhile possesses photodynamic effect to generate 1O2; notably, PdNS has catalase-like activity-dependent extra photodynamic effect upon H2O2 addition. PdNS+H2O2+NIR employs a collectively synergistic mechanism of nanoknife effect, peroxidase/catalase-like catalytic activity, photothermal effect, and photodynamic effect for bacterial killing. PdNS+H2O2+NIR causes compensatory elevated phospholipid biosynthesis, disordered energy metabolism, increased cellular ROS levels and excessive oxidative stress, and inhibited nucleic acid synthesis in bacteria. In mice, PdNS+H2O2+NIR gives >92.7% bactericidal rates at infected wounds and almost the full recovery of infected wounds, and it leads to extensive down-regulation of proinflammatory pathways and comprehensive up-regulation of wound healing pathways, conferring elevated inflammation resolution and meanwhile accelerated wound repair. PdNS+H2O2+NIR represents a highly efficient nanoplatform for photoenhanced treatment of superficial infections.