Eradication Of Infection Research Articles

Tracing the path of Quorum sensing molecules in cystic fibrosis mucus in a biomimetic in vitro permeability platform

P. aeruginosa employs specific quorum sensing (QS) mechanisms to orchestrate biofilm formation, enhancing resistance to host defences. In physiological conditions, QS molecules permeate the lung environment and cellular membrane to reach the cytoplasmic Aryl Hydrocarbon Receptor (AhR) that is pivotal for activating the immune response against infection. In pathological conditions like cystic fibrosis (CF) this interkingdom communication is altered, favouring P. aeruginosa persistence and chronic infection. Here, we aim to investigate the molecular journey of QS molecules from CF-like environments to the cytoplasm by quantifying via HPLC-MS the permeability of selected QS molecules (quinolones, lactones, and phenazines) through in vitro models of the two main biological lung barriers: CF-mucus and cellular membrane. While QS molecules not activating AhR exhibit intermediate permeability through the cellular membrane model (PAMPA) (1.0–4.0 × 10−6 cm/s), the AhR-activating molecule (pyocyanin) shows significantly higher permeability (8.6 ± 1.4 × 10−6 cm/s). Importantly, combining the CF mucus model with PAMPA induces a 50% decrease in pyocyanin permeability, indicating a strong mucus-shielding effect with pathological implications in infection eradication. This study underscores the importance of quantitatively describing the AhR-active bacterial molecules, even in vitro, to offer new perspectives for understanding P. aeruginosa virulence mechanisms and for proposing new antibacterial therapeutic approaches.

Biomimetic Electrodynamic Metal-Organic Framework Nanosponges for Augmented Treatment of Biofilm Infections.

Electrodynamic therapy (EDT) is a promising alternative approach for antibacterial therapy, as reactive oxygen species (ROS) are produced efficiently in response to an electric field without relying on endogenous H2O2 and O2. However, the inherent toxicity of metallic catalysts and numerous bacterial toxins during the therapeutic process still hinder its development. Herein, biomimetic metal-organic (MOF@EV) nanosponges composed of ginger-derived extracellular vesicles (EVs), and electrodynamic metal-organic frameworks (MOFs) are developed for the eradication of bacterial infections and the absorption of toxins. The prolonged circulation time of MOF@EV in vivo facilitates their accumulation at infection sites. More interestingly, MOF@EV can behave as nanosponges and effectively prevent host cells from binding to bacterial toxins, thereby reducing damage to cells. Subsequently, the MOF@EV nanosponges are discovered to work as electro-sensitizers, which is confirmed through both theoretical calculation and experimental verification. As a result, ROS is continuously produced under the electric field to achieve effective EDT-mediated bacterial eradication. Meanwhile, the treatment process of MOF@EV in vivo is visualized in mice infected with luciferase-expressing Staphylococcus aureus (S. aureus), and excellent biofilm eradication capacity and detoxification efficiency are demonstrated in a subcutaneous abscess model. This work provides a promising strategy for the treatment of bacterial infections.

Efficacy and safety of vonoprazan-based bismuth quadruple therapy for first-line Helicobacter pylori eradication: A large-scale, real-world study.

Vonoprazan (VPZ) has been shown to have superior acid-inhibitory effects compared to proton pump inhibitors (PPIs). However, there is a paucity of research examining the efficacy of vonoprazan-based bismuth quadruple therapy (VBQT) in the eradication of primary Helicobacter pylori infection. This study aimed to evaluate the effectiveness and safety of VBQT as a first-line treatment for H pylori eradication. This retrospective, real-world, single-arm study included consecutive treatment-naive patients who received VBQT (VPZ 20 mg, amoxicillin 1000 mg, clarithromycin 500 mg, bismuth potassium citrate 220 mg, all administered twice daily for 14 days) for H pylori eradication between March 1, 2021, and May 30, 2023. The study included both outpatients and inpatients. Eradication rates were assessed using 13C-urea breath tests or 14C-urea breath tests performed 4 to 6 weeks after treatment. The primary outcomes included eradication rates, adverse events, and treatment compliance. A total of 612 H pylori-infected patients were included in the study. The intention-to-treat (ITT), modified ITT (MITT), and per-protocol analyses showed H pylori eradication rates of 84.3% (95% CI: 812% to 87.1%), 95.9% (95% CI: 93.9% to 97.4%), and 96.4% (95% CI: 94.4% to 97.8%), respectively. In the ITT analysis, the adverse event rate was 12.7%, and the treatment compliance rate was 96.9%. In real-world practice, the VBQT regimen demonstrates excellent efficacy and favorable tolerability as a first-line therapy for H pylori eradication.

Fungal Shoulder Periprosthetic Infections: A Systematic Review.

Background: Data regarding fungal PJIs of the shoulder are scarce. The present systematic review aims to identify and evaluate all published shoulder fungal PJIs in an effort to better understand the diagnostic and therapeutic approach to these infections. Methods: A systematic review according to the PRISMA guidelines was conducted, locating all shoulder fungal PJIs. The initial search located 1435 articles. Data were collected on demographics, the causative fungus, antifungal treatment (AFT), surgical interventions, and infection outcomes. Results: After screening and implementation of the inclusion criteria, a total of 10 articles, including 10 cases, were eligible. The sample's mean age was 62.44 years. Diabetes mellitus was the most common comorbidity (30%), while 70% were immunocompromised. Candida spp. was the most common causative fungus (nine cases; 90%), while all cases were confirmed with cultures. In three cases (30%), there was bacterial co-infection. The mean duration of antifungal treatment (AFT) was 8.4 weeks, while the preferred agent was fluconazole (60% of cases), followed by amphotericin B (30%). Most cases (50%) underwent resection arthroplasty as part of the treatment, while two-stage revision arthroplasty was performed in 30%. Infection's eradication was reported in 90% of the studied cases. Conclusions: The diagnosis and management of fungal periprosthetic shoulder infections are particularly challenging and require a multidisciplinary approach. The combination of antifungal therapy and tailored surgical strategies is crucial, but further research is needed to refine treatment protocols and address the unique considerations in shoulder PJIs.

Hepatitis B infection: Evaluation of demographics and treatment of chronic hepatitis B infection in Northern-western Tanzania.

Chronic hepatitis B virus (HBV) infection is still a major public health problem. In response to the World Health Organization (WHO), Tanzania implemented immunization and treatment to achieve the eradication of HBV infection by 2030. To achieve this goal, frequent updates of demographic data, antiviral therapy eligibility, and uptake are essential. We therefore evaluated demographic data, antiviral therapy eligibility, and uptake among chronically HBV-infected patients attending at Bugando Medical Centre (BMC), Tanzania. A cross-sectional study enrolled 196 chronic HBV patients from April 23, 2023, to October 10, 2023, at BMC, where 100 and 96 patients were retrospectively and prospectively enrolled, respectively. Study's ethical clearance and permission were observed by the Catholic University of Health and Allied Sciences/Bugando Medical Centre research ethics and review committee and the Bugando Medical Centre management respectively. For all patients, socio-demographic data and whole blood samples were obtained. Full blood picture, alanine and aspartate amino transferases, and HBV viral load parameters were determined. Aspartate-Platelet Ratio Index (APRI) and Fibrosis Four (FIB-4) scores were calculated according to their respective formulas. Therapy eligibility and uptake were evaluated according to the 2015 WHO HBV prevention, treatment, and care guidelines. The data were summarized and analysed using STATA version 15. The median age for all patients was 39 [IQR: 32-47.5] years. Nearly all study patients, 99% (194/196), were older than 20 years old, with significant male dominance (73.5% [144/196] versus 26.5% [52/196]; p<0.0001). Anti-HBV antiviral therapy eligibility was 22.4%, while uptake was 6.8% (3/4), which was significantly lower than the WHO expectation of 80% (p <0.0001). Almost all chronically HBV-infected patients attending at BMC were older than 20 years old and were significantly dominated by males. Antiviral therapy uptake was remarkably lower than expected by the WHO towards combating HBV infection by 2030.

Effectiveness of zero dose HBV vaccine on prevention of HBV breakthrough infection among vaccinated Egyptian children

Hepatitis B virus (HBV) is a vaccine preventable disease. Sufficient post vaccination response is critical step to achieve infection eradication. Vaccine hypo-responsiveness is a major risk factor for HBV chronic infection. We aimed to evaluate the effectiveness of birth dose HBV vaccine in preventing perinatal HBV infection and to detect the rate of HBV surface antibody (HBs-Ab) seroconversion and its relation to interleukin-4 polymorphism (IL-4 PM) among a group of vaccinated Egyptian infants. This observational analytical study involved 77 infants aged 6 to 12 months who received 4 doses of HBV vaccine including a zero dose. We measured serum levels of HBV-DNA and hepatitis B surface antigen (HBsAg) as markers of infectivity, and the level of (HBsAb) to assess vaccine responsiveness. Cytokine gene analysis to detect IL-4 gene polymorphism and its association with vaccine un-responsiveness were investigated. We observed that none of the vaccinated infants acquired HBV infection. Of the included 77 infants, seroconversion against HBV was detected in 72 (93.5%), 28 (36.4%) had low response and 44 (57.1%) had high response. While 5 (6.5%) were non responders. There was significant association between IL-4 gene polymorphism and the poor seroconversion after HBV vaccination. (p=0.03). Furthermore, HBsAb titer was significantly lower in children who have IL-4 gene polymorphism (p=0.014). In conclusion, implementation of birth-dose HBV vaccination is effective for prevention of perinatal infection, but seroconversion rate may be insufficient to induce long term protection. IL-4 gene polymorphism is associated with poor response to HBV vaccine.

Electrically-driven drug delivery into deep cutaneous tissue by conductive microneedles for fungal infection eradication and protective immunity

Fungal infections affect over 13 million people worldwide and are responsible for 1.5 million deaths annually. Some deep cutaneous fungal infections may extend the dermal barriers to cause systemic infection, resulting in substantial morbidity and mortality. However, the management of deep cutaneous fungal infection is challenging and yet overlooked by traditional treatments, which only offer limited drug availability within deep tissue. In this study, we have developed an electrically stimulated microneedle patch to deliver miconazole into the subcutaneous layer. We tested its antifungal efficacy using in vitro and ex vivo models that mimic fungal infection. Moreover, we confirmed its anti-fungal and wound-healing effects in a murine subcutaneous fungal infection model. Furthermore, our findings also showed that the combination of miconazole and applied current synergistically stimulated the nociceptive sensory nerves, thereby activating protective cutaneous immunity mediated by dermal dendritic and γδ-T cells. Collectively, this study provides a new strategy for minimally invasive delivery of therapeutic agents and the modulation of the neuro-immune axis in deep tissue.

Targeted recruitment of immune effector cells for rapid eradication of influenza virus infections

Despite much research, considerable data suggest that influenza virus remains a serious health problem because i) the effectiveness of current vaccines ranges only from 19% to 60%, ii) available therapies remain ineffective in advanced stages of disease, iii) death rates vary between 25,000 and 72,000/year in the United States, and iv) avian influenza strains are now being transmitted to dairy cattle that in turn are infecting humans. To address these concerns, we have developed zanDR, a bispecific small molecule that binds and inhibits viral neuraminidase expressed on both free virus and virus-infected cells and recruits naturally occurring anti-rhamnose and anti-dinitrophenyl (DNP) antibodies with rhamnose and DNP haptens. Because the neuraminidase inhibition replicates the chemotherapeutic mechanism of zanamivir and oseltamivir, while rhamnose and DNP recruit endogenous antibodies much like an anti-influenza vaccine, zanDR reproduces most of the functions of current methods of protection against influenza virus infections. Importantly, studies on cells in culture demonstrate that both of the above protective mechanisms remain highly functional in the zanDR conjugate, while studies in lethally infected mice with advanced-stage disease establish that a single intranasal dose of zanDR not only yields 100% protection but also reduces lung viral loads faster and ~1,000× more thoroughly than current antiviral therapies. Since zanDR also lowers secretion of proinflammatory cytokines and protects against virus-induced damage to the lungs better than current therapies, we suggest that combining an immunotherapy with a chemotherapy in single pharmacological agent constitutes a promising approach for treating the more challenging forms of influenza.

Modular component exchange has no advantage in Debridement, Antibiotics and Implant Retention (DAIR) for early onset hip and knee prosthetic joint infection.

Debridement, Antibiotics and Implant Retention (DAIR) has been the mainstay of treatment for early onset periprosthetic joint infection in spite of variable results. Modular component exchange is a widely recommended strategy to improve success rates with DAIR though very strong evidence to support its practice is still lacking. Eighty six patients underwent DAIR for early onset PJI following primary hip and knee arthroplasty were divided into two groups for this retrospective review. 45 patients (group 1) underwent DAIR with modular component exchange and 41 patients without exchange (group 2). We compared success rates based on infection eradication (primary outcome variable) and need for revision surgical procedures between these two groups. We also assessed differences in primary outcome based on type of arthroplasty, timing of DAIR and addition of local antibiotics. The overall success rate after DAIR was 71%. The outcome was similar in both groups (69% vs 74%, P = 0.66). The need for revision surgical procedures was 27% which was similar in both groups (P = 0.98) with 23% needing revision of prosthetic components. Type of arthroplasty (hip or knee) and addition of local antibiotics had no bearing on infection eradication after DAIR with or without modular component exchange. DAIR with in 45days of primary arthroplasty had significantly higher success rate compared to DAIR after 45days in both groups. We observed that modular component exchange did not improve infection eradication after DAIR for early onset PJI following hip and knee arthroplasty. Reasonable success rates can be expected after DAIR especially if the patient develops early clinical signs and the procedure is carried out as early as possible.

Encapsulation of Mentha aquatica methanol extract in alginate hydrogel promotes wound healing in a murine model of Pseudomonas aeruginosa burn infection

Burn injuries are the fourth most prevalent devastating form of trauma worldwide. Among the most extensively explored materials, composite dressings with alginate loaded with herbal extract can be mentioned. This research aimed to develop a sodium alginate (SA)-based hydrogel encapsulated with Mentha aquatica (MA) methanol extract and investigate its therapeutic efficacy in the infected burn mouse model. SEM, FTIR, in vitro extract release, HPLC, mechanical test, contact angle, swelling, degradability, and temperature response properties were used to analyze the hydrogel scaffold's physicochemical structure. Additionally, the antibacterial activity and MIC level of the extract, cell cytotoxicity, and macroscopic and microscopic analysis of the wound healing process were done using Masson's trichrome and hematoxylin-eosin staining. The physicochemical properties of the SA hydrogel encapsulated with MA extract were verified. The lowest inhibitory dose of the extract was determined to be 12.5 mg/ml. Application of SA/MA hydrogel to localized wounds of deep third-degree burns demonstrated faster tissue regeneration, collagen recovery, and eradication of bacterial infection. This research focused on the design and the preparation of a novel and effective biomaterials-based medical product, which has the potential to rehabilitate infected and injured skin tissue; therefore, it can be a promising candidate for wound dressing applications.

Effectiveness of long-term low-dose aspirin in the prevention of gastric cancer after Helicobacter pylori eradication: study design and rationale of Ardabil gastric cancer randomized placebo-controlled prevention trial (AGCPT)

BackgroundIn addition to Helicobacter pylori (H. pylori) infection eradication, some medications, including aspirin, metformin, and statins, have been suggested to have protective effects against gastric cancer (GC) development in observational studies. We launched the Ardabil gastric cancer randomized placebo-controlled prevention trial (AGCPT) to evaluate the effectiveness of long-term low-dose aspirin use for the prevention of development and mortality of GC after H. pylori eradication.Methods/designAGCPT is a prospective population-based double-blind, randomized clinical trial. The study sample was targeted at 21,000 participants aged from 35 to 70 years old, both sexes, in Ardabil, a province in northwest Iran with relatively high rates of GC incidence and mortality. All eligible participants were initially tested for H. pylori infection using a H. pylori stool antigen test. Participants with positive tests undergo H. pylori eradication by standard treatment regimens. All participants with a negative test and those with a positive test with a subsequent confirmed H. pylori eradication test were entered into the intervention phase. In the intervention phase, participants were allocated randomly into either the treatment (daily oral consumption of 81 mg enteric-coated aspirin tablets) arm or the control (placebo) arm using permuted balanced blocks. Subjects will be followed for an average period of 10 years to evaluate the incidence and mortality rates of GC.DiscussionIn addition to preventing other diseases like cardiovascular events, aspirin may prevent GC incidence and mortality. AGCPT will investigate the difference between the two study arms in the proportion of the cumulative incidence and mortality rates of GC. The study’s results may help policymakers and researchers update the strategies for GC prevention.Trial registrationThis trial with the registry name of “The effect of Low-dose Aspirin in the Prevention of Gastric Cancer” was registered in the Iranian Registry of Clinical Trials, IRCT.ir, under the identifier IRCT201105082032N3. Registered on April 21, 2017.

Fluorescent Microneedle‐Based Theranostic Patch for Naked‐Eye Monitoring and On‐Demand Photo‐Therapy of Bacterial Biofilm Infections

AbstractThe eradication of recalcitrant bacterial biofilm infections necessitates the development of speedy diagnostics and prompt therapeutics. However, constructing a portable versatile platform that enables in situ monitoring of biofilm infections accompanied by potent antibiofilm activity remains challenging. To address this conundrum, a microneedle theranostic patch (Mn: C/G@MN) is devised by incorporating an innovative biophotonic probe (manganese‐doped carbon dots, Mn: CDs) into methacrylated gelatin for visual monitoring of biofilm infection and on‐demand photo‐therapy. The Mn: C/G@MN patch penetrates the physical barrier of biofilms to track their acidic microenvironment, exhibiting a visualized fluorescence color change (from yellow to turquoise) to enable naked‐eye monitoring of biofilm infection. Furthermore, the Mn: C/G@MN patch can drastically eradicate biofilm on‐demand through the synergy of local hyperthermia and hydroxyl radical (•OH) storm under 808 nm near‐infrared light illumination, enabling the damaging of extracellular polymeric substances (EPS) matrix to disperse biofilms and subsequently kill detached bacteria. Both in vitro and in vivo findings authenticate that biofilm infection monitoring‐and‐treating can be achieved. Moreover, the versatile Mn: C/G@MN patch is conducive to suppressing inflammatory responses, expediting collagen deposition, stimulating angiogenesis, and accelerating biofilm‐infected wound healing. As envisaged, this work highlights the potential of such a versatile platform for application in integrated theranostics for biofilm infection.

MIP3α-Rel Mtb intranasal DNA vaccination induces reactive T-cell infiltration into the lungs in mice and macaques.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the leading cause of mortality due to a single infectious organism. While generally curable, TB requires a lengthy and complex antibiotic regimen, due in large part to bacteria that can shift to a persistent state in the presence of antibiotic pressure. Rel Mtb is the primary enzyme regulating the stringent response, which contributes to the metabolic shift of Mtb to a persistent state. Targeting Rel Mtb with a vaccine to eliminate persistent bacteria through the induction of Rel Mtb -specific T-cell immunity in combination with antibiotics to kill dividing bacteria has shown promise in model systems. In a mouse model of Mtb infection, a vaccine created by genetically fusing rel Mtb to the chemokine macrophage inflammatory protein 3α ( MIP3 α), a ligand for the CC chemokine receptor type 6 (CCR6) present on immature dendritic cells, has been shown to enhance T-cell responses and accelerate eradication of infection in mouse models compared to a vaccine lacking the chemokine component. In this study, immunogenicity studies in the mouse and rhesus macaque models provide evidence that intranasal administrations of the DNA form of the MipRel vaccine led to enhanced lung infiltration of T cells after a series of immunizations. Furthermore, despite similar T-cell immunity seen in PBMCs between MipRel and Rel vaccinations, lung and bronchoalveolar lavage cell samples are more enriched for cytokine-secreting T cells in MipRel groups compared to Rel groups. We conclude that intranasal immunization with a MIP-3α fusion vaccine represents a novel strategy for use of a simple DNA vaccine formulation to elicit T-cell immune responses within the respiratory tract. That this formulation is immunogenic in a non-human primate model historically viewed as poorly responsive to DNA vaccines indicates the potential for clinical application in the treatment of Mtb infection, with possible application to other respiratory pathogens. Future studies will further characterize the protective effect of this vaccination platform.

Use of intra-operative fluorescence imaging in periprosthetic joint infection: State of the art and future perspectives.

In periprosthetic joint infections (PJIs), the surgeon's role becomes pivotal in addressing the infection locally, necessitating the surgical removal of infected and necrotic tissue. Opportunity to enhance the visualization of infected tissue during surgery could represent a game-changing innovation. The aim of this narrative review is to delineate the application of intraoperative fluorescence imaging for targeting infected tissues in PJIs. A systematic review, adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, was carried out. The search included multiple online database; MEDLINE, Scopus, and Web of Science. For data extraction the following were evaluated: (i) diagnosis of musculoskeletal infection; (ii) use of intraoperative fluorescence imaging; (iii) infected or necrotic tissues as target. Initially, 116 studies were identified through online database searches and reference investigations. The search was narrowed down to a final list of 5 papers for in-depth analysis at the full-text level. Subsequently, 2 studies were included in the review. The study included a total of 13 patients, focusing on cases of fracture-related infections of the lower limbs. The primary and crucial role for orthopedic surgeons in PJIs is the surgical debridement and precise removal of necrotic and infected tissue. Technologies that enable clear and accurate visualization of the tissue to be removed can enhance the eradication of infections, thereby promoting healing. A promising avenue for the future involves the potential application of intraoperative fluorescence imaging in pursuit of this objective.

Detection and Eradication of a Demodex Infestation in Specific Pathogen-free High-barrier Laboratory Mouse Facility Housing Immunocompromised Animals.

Demodex mites are a common ectoparasite in nonlaboratory Mus musculus (mouse) populations. While infrequently reported in laboratory research mice, the prevalence is thought to be as high as 35% of all colonies. Here, we discuss an outbreak of Demodex within an SPF high-barrier vivarium housing laboratory mice first identified through commercial sentinel-free PCR testing. Consequently, in-house PCR-mediated identification of individually infected cages was conducted, and a successful method for eradication of secondary reemergent infection was generated via recurrent testing and empirical 12-wk treatment with 3 mg/kg moxidectin and 13 mg/kg imidacloprid. While we were unable to determine the source of our primary outbreak, the secondary outbreak was traced to nongenetically modified C57B6/J immunocompetent mice, which were capable of harboring subclinical infection below our PCR threshold. Our eventual successful eradication of Demodex confirmed, first, that in-house PCR detection is a cost-effective means of monitoring an outbreak; second, that treatment with 3 mg/kg moxidectin and 13 mg/kg imidacloprid does kill Demodex mites in laboratory mice; and third, that treatment of only PCR-positive mice is an insufficient way to control an outbreak. Taken together, our methodological approach for infestations such as Demodex suggests it is possible to eradicate them but that it requires a thorough, systematic, and aggressive treatment regimen. Moreover, we recommend that all cages derived from infected animals be treated as positive, regardless of PCR positivity, to prevent recurrent and/or persistent infections within an animal colony.

Biofilm Formation is Durably Prevented on Pre-Fabricated Antibiotic Cement Spacers Compared to Cobalt Chrome and Polyethylene

BackgroundA 2-stage revision remains the standard for managing chronic periprosthetic joint infection. Despite multiple spacer options, whether a particular one better resists biofilm formation remains unclear. Prefabricated polymethylmethacrylate (PMMA) articulating spacers containing antibiotics and a proprietary pore structure were developed to increase antibiotic elution characterized by a rapid burst phase for the initial one to two days and an extended slow-release phase for > 28 days. This in vitro study determined whether biofilm formation is prevented during the initial rapid burst phase and/or the slow-release phase. MethodsS. aureus-Xen36 was incubated in 1.5 mL of Luria-Bertani broth with PMMA discs with the proprietary pore structure either with or without gentamycin and vancomycin or with ‘Hoffman style’ positive-control discs (ultra-high molecular weight polyethylene or cobalt-chrome). Nonadherent bacteria were removed by three phosphate buffered saline rinses every 20 to 24 hours. Planktonic bacterial growth in the culture broth and biofilm formation on the discs were measured by colony forming unit (CFU) counting and resazurin reduction assays. Experiments were repeated > four times. ResultsNo detectable planktonic bacterial growth or biofilm formation occurred in cultures containing PMMA with antibiotics (≤ 15 CFUs/disc), whereas biofilms formed on PMMA without antibiotics, ultra-high molecular weight polyethylene, and cobalt-chrome (1 × 107 to 4 × 108 CFUs/disc, P < 0.0001). Biofilm formation was confirmed by a 100-fold decrease in sensitivity to vancomycin. To determine whether the antibiotic slow-release phase is sufficient to block biofilm formation, PMMA discs with antibiotics were preeluted for 14 days with multiple saline changes prior to bacterial inoculation. After antibiotic elution, still no detectable biofilms formed on PMMA discs with antibiotics (≤ 15 CFUs/disc, P < 0.0001). ConclusionsAntibiotic release during both the initial and slow-release phases prevented biofilm formation on PMMA with the proprietary pore structure. This may translate into improved infection eradication rates clinically.

Can a 1.5-Stage Revision be an Effective Alternative for Chronic Periprosthetic Hip and Knee Infections? A Systematic Review and Meta‐Analysis

BackgroundA 1.5-stage revision could be an alternative to a 2-stage revision for treating hip and knee chronic periprosthetic infections, guaranteeing the maintenance of joint function and infection control and preventing infection-free patients from undergoing further surgery. Our systematic review aimed to answer several questions about the indication, the infection eradication rate, and the long-term functional outcome of 1.5-stage revisions used to treat chronic periprosthetic infections of the hip and knee. MethodsA systematic review of the literature was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including studies dealing with the use of 1.5-stage and two-stage surgery for chronic periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) or total hip arthroplasty (THA). The Coleman Methodology Score and the Methodological Index for Non-randomized Studies (MINORS) score were used to assess the quality of the studies. A meta-analysis was performed to evaluate the infection eradication rate using either the 1.5-stage revision or the two-stage technique. A total of 494 patients (111 hips and 385 knees) who underwent 1.5-stage with a mean age of 69 years (range, 61 to 82) were identified in the ten included studies. ResultsThe most common cause of reoperation was the conversion to the definitive prosthesis, followed by aseptic loosening. Infection control was reached in 84.6% of the 1.5-stage and 76.1% of the two-stage cohorts. The infection recurrence rate was higher in the two-stage cohort than the 1.5-stage group (21.8 versus 14.3%). ConclusionThe 1.5-stage technique represents a valid treatment option in selected patients who have chronic PJI who cannot undergo further surgeries, adding together the benefits of the one- and two-stage procedures. Furthermore, the 1.5-stage showed a better success rate in the infection resolution than the two-stage technique.

Synergistic effects of novel penicillin-binding protein 1A amino acid substitutions contribute to high-level amoxicillin resistance of Helicobacter pylori.

The growing resistance to amoxicillin (AMX)-one of the main antibiotics used in Helicobacter pylori eradication therapy-is an increasing health concern. Several mutations of penicillin-binding protein 1A (PBP1A) are suspected of causing AMX resistance; however, only a limited set of these mutations have been experimentally explored. This study aimed to investigate four PBP1A mutations (i.e., T558S, N562H, T593A, and G595S) carried by strain KIN76, a high-level AMX-resistant clinical H. pylori isolate with an AMX minimal inhibition concentration (MIC) of 2 µg/mL. We transformed a recipient strain 26695 with the DNA containing one to four mutation allele combinations of the pbp1 gene from strain KIN76. Transformants were subjected to genomic exploration and antimicrobial susceptibility testing. The resistance was transformable, and the presence of two to four PBP1A mutations (T558S and N562H, or T593A and G595S), rather than separate single mutations, was necessary to synergistically increase the AMX MIC up to 16-fold compared with the wild-type (WT) strain 26695. An AMX binding assay of PBP1A was performed using these strains, and binding was visualized by chasing Bocillin, a fluorescent penicillin analog. This revealed that all four-mutation allele-transformed strains exhibited decreased affinity to AMX on PBP1A than the WT. Protein structure modeling indicated that functional modifications occur as a result of these amino acid substitutions. This study highlights a new synergistic AMX resistance mechanism and establishes new markers of AMX resistance in H. pylori.IMPORTANCEThe development of resistance to antibiotics, including amoxicillin, is hampering the eradication of Helicobacter pylori infection. The identification of mechanisms driving this resistance is crucial for the development of new therapeutic strategies. We have demonstrated in vitro the synergistic role of novel mutations in the pbp1 gene of H. pylori that is suspected to drive amoxicillin resistance. Also deepening our understanding of amoxicillin resistance mechanisms, this study establishes new molecular markers of amoxicillin resistance that may be useful in molecular-based antibiotic susceptibility testing approaches for clinical practice or epidemiologic investigations.

Adjunctive N-Acetylcysteine and Lung Function in Pulmonary Tuberculosis

BackgroundTuberculosis remains a global health concern, and half of cured patients have permanent lung injury. N-acetylcysteine (NAC) has shown beneficial antimicrobial, antioxidant, and immunomodulatory effects in preclinical tuberculosis models. We examined its effects on tuberculosis treatment outcomes.MethodsThis prospective, randomized, controlled trial nested within the TB SEQUEL cohort study enrolled 140 adults with moderate or far-advanced tuberculosis. Participants were randomly assigned 1:1 to standard therapy with or without 1200 mg of oral NAC twice daily for days 1 to 112. Clinical evaluations, sputum culture, and spirometry were performed at specified intervals through day 168, after which participants returned to the TB SEQUEL cohort. The primary outcome was culture conversion. Secondary outcomes included whole-blood glutathione levels and lung function.ResultsParticipants were predominantly young, male, and human immunodeficiency virus 1–negative and had heavy sputum Mycobacterium tuberculosis (MTB) infection burdens. NAC increased glutathione levels (NAC × day interaction, 8.48; 95% confidence interval [CI], 1.93 to 15.02) but did not increase stable culture conversion (hazard ratio, 0.84; 95% CI, 0.59 to 1.20; P=0.33). NAC treatment was associated with improved recovery of lung function (NAC × month, 0.49 [95% CI, 0.02 to 0.95] and 0.42 [95% CI, −0.06 to 0.91] for forced vital capacity and forced expiratory volume in the first second, respectively, as percentages of predicted values). The effects of NAC on lung function were greatest in participants with severe baseline lung impairment and appeared to persist beyond the period of NAC administration. Rates of serious or grade 3 to 4 nonserious adverse events did not differ between the groups.ConclusionsDespite increasing whole-blood glutathione levels, NAC did not affect eradication of MTB infection in adults with pulmonary tuberculosis that was moderate to far advanced. Secondary outcomes of lung function showed changes that merit further investigation. (Funded by TB SEQUEL grant 01KA1613 of the German Ministry for Education and Research, the Health Africa Project, and the German Center for Infection Research; ClinicalTrials.gov number, NCT03702738.)

Stability of generalized models for HIV-1 dynamics with impaired CTL immunity and three pathways of infection

Highly active antiretroviral therapy (HAART) stands out as the most effective treatment for human immunodeficiency virus type-1 (HIV-1). While total eradication is still difficult, HAART can dramatically lower the virus's plasma viral level below the detection threshold. The activation of latently infected cells is considered to be the main obstacle to the total eradication of HIV-1 infection. This study investigates the dynamic characteristics of two generalized HIV-1 infection models taking into account the impairment of cytotoxic T lymphocytes (CTLs). These models include CD4+T cells that are latently infected and equipped with the capability to engage in cell-to-cell infection and elude immune responses. We introduce models featuring three infection pathways: virus-to-cell (VTC), latent cell-to-cell (L-CTC), and active cell-to-cell (A-CTC). The three pathways' infection rates are characterized by general functions, which cover the many types of infection rates documented in the literature. The second model integrates three distinct types of distributed-time delays. We demonstrate the validity of the suggested models, through their well-posedness. We determine the basic reproduction ratio (ℜ0) of the systems. Lyapunov functions and LaSalle's invariance principle are employed to verify that the global stability of both the virus-free steady state (O0) and the virus-persistence steady state (O1). More precisely, O0 achieves global asymptotic stability when ℜ0 ≤ 1, whereas O1 attains global asymptotic stability when ℜ0 &amp;gt; 1. To demonstrate the impact of the parameter values on ℜ0, we examine the sensitivity analysis. It is illustrated that ℜ0 comprises three components, namely ℜ0E, ℜ0P, and ℜ0K, corresponding to the transmissions of VTC, L-CTC, and A-CTC, respectively. Thus, if the L-CTC pathway is disregarded in the HIV-1 infection model, ℜ0 may be underestimated, which could lead to inadequate or erroneous medication therapy focused on eradicating HIV-1 within the body. To demonstrate the associated mathematical outcomes, we conduct numerical simulations through an illustrative example. Specifically, we delve into how the dynamics of HIV-1 are influenced by both immune impairment and time delay. Our findings suggest a significant role of reduced immunity in the progression of the infection. Furthermore, time delays possess the potential to markedly reduce ℜ0, thereby impeding the replication of HIV-1.