Severe Bacterial Infections Research Articles

Depletion of Lachnospiraceae Marks the Development of Antibiotic-Associated Neutropenia in Pediatric Patients

Prolonged antibiotic administration has been associated with peripheral cytopenias in up to 10-15% of patients. Of these, neutropenia is particularly notable because of the associated risk of severe bacterial infections. Yet, the mechanisms underlying antibiotic-associated neutropenia remain poorly understood. Recent studies in murine models demonstrate that antibiotics suppress hematopoiesis by depletion of the intestinal microbiota, with concomitant suppression of basal Type I interferon (IFN) and STAT1 signaling. Oral administration of the microbial metabolites that induce Type I IFN restores normal hematopoiesis in antibiotic-treated mice. These findings support a paradigm in which products of the intestinal microbiota enter the bloodstream and travel to the bone marrow where they promote production of growth cytokines that support normal hematopoiesis. To identify microbiota and microbiota-derived metabolites altered in patients with antibiotic-associated neutropenia, we enrolled pediatric patients receiving antibiotic therapy for a planned duration of fourteen days or more in a multicenter-IRB approved study. We analyzed pre- and post-treatment stool samples from 51 subjects by 16S rRNA sequencing and untargeted metabolomics profiling. Neutropenia occurred in 13% of prospectively enrolled subjects. In total, 10 neutropenic patients were included in the study, with 29 control patients selected by frequency matching for age, race, and ethnicity. Length of intravenous antibiotic treatment, total length of antibiotic treatment, length of stay and admission to the intensive care unit were correlated with the development of neutropenia, whereas type of antibiotic or type of infection were not. Based on 16S rRNA sequencing, alpha diversity was significantly decreased in the stool of patients with neutropenia but not in controls (p= 0.027 vs p= 0.059). Analysis of taxa abundance showed significant depletion of Lachnospiraceae in patients with neutropenia (p=0.043), while no significant difference was identified in controls. Lachnospiraceae are a main producer of short chain fatty acids and have been linked to hematopoietic stem cell transplant outcomes. Partial least square-discriminant analysis (sPLS-DA) showed that the metabolomes of neutropenic and control stools were similar at baseline. However, 17 metabolites were differentially abundant after antibiotic treatment in the neutropenic group but not in the control group including citrulline, tyrosine, and N-acetylglucosamine/N-acetylgalactosamine. Future work will assess whether these compounds can rescue antibiotic-associated neutropenia in the animal model. This is the first clinical study linking changes in the intestinal microbiota with antibiotic associated neutropenia. An improved understanding of the molecular mechanisms by which the microbiome sustains normal hematopoiesis will lead to ways to prevent and treat antibiotic-associated bone marrow suppression.

865. Same Shift Susceptibility Testing of Cefepime-Taniborbactam and Cefiderocol Using The Selux Next-Generation Phenotyping System

Abstract Background Robust, efficient, and reliable antimicrobial susceptibility testing (AST) systems are an integral component of effective antibiotic treatment. Multi-drug resistant (MDR) bacteria continue to emerge at alarming rates, requiring continuous innovation and development of new antibiotics. Among the new promising treatments for severe bacterial infections caused by carbapenem-resistant gram-negative bacteria, Cefiderocol (FDC) and Cefepime-Taniborbactam (FTB) have emerged as two frontrunners. FDC is the only FDA-approved siderophore cephalosporin, and FTB pairs the fourth-generation cephalosporin Cefepime, with Taniborbactam, a novel beta-lactamase inhibitor. AST results are paramount when directing therapy for patients with MDR infections, yet there is an average 3-year delay between the approval of new antibiotics and 510k submissions for new agents on automated AST systems. This is typified by FDC, for which there are currently no FDA-cleared automated AST systems. Here we assess the accuracy of FDC and FTB AST results using the Selux Next-Generation Phenotyping System. Methods For both FTB and FDC susceptibility, AST was performed using the Selux AST system and compared to CLSI broth microdilution (BMD) reference method in either cation-adjusted Muller Hinton broth (CAMHB) or its Iron depleted counterpart (ID-CAMHB). FDC, was tested in ID-CAMHB across 44 total CDC AR-Bank carbapenem-resistant K. pneumoniae, A. baumannii, and P. aeruginosa species. 34 CDC AR-Bank Strains predominantly resistant (30/34) to Cefepime were used to assess FTB. For FDC Essential Agreement (EA) and Categorical Agreement (CA) relative to ID-CAMHB were determined according to FDA breakpoints. FTB breakpoints were based on FDA breakpoints for Cefepime. For both agents, a comparison of BMD and the Selux system was accessed by EA and CA. Results The Selux AST system produced MICs to FDC with an average accuracy of 98% EA and 98% CA in ID-CAMHB (Table 1). In FTB, the Selux AST system produced MICs with an average accuracy of 94% EA and 100% CA in CAMHB (Table 2). Conclusion These data demonstrate the ability of the Selux NGP system to provide accurate results for FDC and FTB. This is the first known demonstration of an automated AST system for these important new drugs. Disclosures David Jimenez, B.S., Selux Diagnostics: Employee Kristin Baker, PhD, Selux Diagnostics: Employee Kelly Flentie, PhD, Selux Diagnostics: Employee Kristen Roberts, BS, Selux Diagnostics: Stocks/Bonds Gabriel Michaels, n/a, Selux Diagnostics: Employee Eric Stern, PhD, Selux Diagnostics: Board Member|Selux Diagnostics: Ownership Interest

Antibacterial Activity of River Water Bacteriophage against Multidrug-resistant Gram-negative Bacteria, An In vitro Study

Microbes show a high antimicrobial resistance due to a high rate of mutations predisposed by many factors, especially the abuse of antibiotics. Therefore, there is a great need for an alternative therapeutic agent for infectious diseases caused by microbes resistant to antibiotics. Bacteriophages are viruses parasitizing microbes, that got a big scientist’s attention due to their ability as an alternative therapy for severe bacterial infections. This study is devoted to identifying bacteriophage from river water on tested pathogenic isolates isolated from clinical cases of UTI in vitro and finding out the effect of phage on these bacterial isolates as an initial step of further in vivo phage therapeutic study on the same tested isolates. The results showed a significant bactericidal effect of the isolated bacteriophages against the pathogenic bacterial isolates.

Evaluation of Negative Pressure Wound Therapy in the Management of Fournier's Gangrene.

Introduction Necrotizing soft tissue infections (NSTIs), including Fournier's gangrene (FG), are severe polymicrobial bacterial infections characterized by rapidly spreading inflammation and tissue necrosis. This study aims to compare the clinical outcomes of vacuum-assisted closure (VAC) dressing and conventional dressing in patients with FG. Materials and methods A prospective study was conducted from December 2020 to May 2022, including patients with clinical features suggestive of FG. Patients were divided into two groups: conventional dressing and VAC dressing. Relevant clinical data, including age, duration of hospital stay, wound status, Fournier's gangrene severity index (FGSI) scores, sepsis markers (C-reactive protein (CRP), neutrophil-to-lymphocyte ratio, and procalcitonin), and pain assessment, were recorded and compared between the two groups. Results A total of 84 patients were included in the study, with 42 patients in each group. The mean age was 57.48 ± 15.74 years in the conventional dressing group and 50.83 ± 13.95 years in the VAC dressing group. VAC dressing was associated with a significantly shorter duration of hospital stay (8.14 ± 3.13 days) compared to conventional dressing (11.36 ± 4.75 days). The average time taken for wound closure was significantly reduced in the VAC dressing group (63 ± 14.81 days) compared to the conventional dressing group (112.56 ± 13.82 days). FGSI scores showed significant improvement after debridement in both groups, with lower scores in the VAC dressing group at discharge. Sepsis markers such as CRP and serum procalcitonin exhibited a significant decrease after VAC application. Discussion The study demonstrates that VAC therapy is associated with better clinical outcomes in FG, including reduced duration of hospital stay, faster wound closure, improved FGSI scores, decreased sepsis markers, and reduced pain. These findings align with previous studies highlighting the advantages of VAC therapy over conventional dressing methods. Conclusion VAC therapy provides significant benefits in the management of FG, leading to improved clinical outcomes and patient quality of life. It offers advantages such as shorter hospital stays, faster wound closure, and reduced sepsis markers. The application of VAC dressing should be considered a valuable treatment modality for FG.

Applying the Novel EHA/EBMT Grading System for Icaht Following CAR-T Therapy: Comparative Incidence across Disease Entities and Association with Infections and Mortality

Background: Hematological toxicity is a frequent side effect of CAR-T therapy and predisposes for severe infectious complications. Recently, the EHA/EBMT consensus grading for Immune Effector Cell Associated HematoToxicity (ICAHT) was developed ( Rejeski et al. Blood 2023). In contrast to existing grading systems such as the CTCAE, the novel ICAHT grading integrates both the depth and duration of neutropenia. We hypothesized that ICAHT severity is associated with key clinical sequelae such as transfusion requirements, hospitalization, severe infections, and adverse treatment outcomes. Methods: We applied the novel grading of early ICAHT (day 0-30) to a multicenter retrospective real-world cohort of 549 patients treated with BCMA- or CD19-directed CAR T-cells for relapsed/refractory B-cell malignancies (334 large B-cell lymphoma [LBCL], 112 multiple myeloma [MM], 103 mantle cell lymphoma [MCL]) across twelve international sites (Germany, France, Spain, USA). Hematotoxicity endpoints included the total cumulative duration of severe neutropenia (ANC <500/µL, day 0-60) and phenotypes of neutrophil recovery ( Rejeski et al. Blood 2021). Infections were studied until day +90 after CAR-T and were graded on a 5-grade scale as mild, moderate, severe, life-threatening, or fatal. Non-relapse mortality (NRM) was defined as death following CAR-T without evidence of relapse or progression. Kaplan-Meier estimates of progression-free (PFS) and overall survival (OS) were compared using log-rank test. Results: Our study cohort included 424 patients without severe ICAHT (absent or grade 1-2) and 125 patients with severe ICAHT (grade 3-4). The distribution of mild (1°), moderate (2°), severe (3°) and life-threatening (4°) ICAHT was 36%, 29%, 17%, and 5%. Seventy patients (13%) did not develop ICAHT of any grade. When comparing ICAHT grades across disease entities, we noted a numeric trend towards increased severe ICAHT in MCL compared to LBCL or MM patients (Grade ≥3: 28% vs. 23% vs. 15%). Patients that subsequently developed severe ICAHT displayed elevated serum inflammatory markers and pronounced cytopenia at baseline - reflected by increased CAR-HEMATOTOX scores (median 3 vs. 1, p<0.0001). On multivariate binary logistic regression, co-stimulatory domain (CD28z), low platelet count, low ANC, low hemoglobin, increased serum ferritin, and the presence of bone marrow infiltration were independent risk factors for severe ICAHT. We noted a strong positive correlation between ICAHT severity and the cumulative duration of severe neutropenia (r=0.92, p<0.0001). The aplastic phenotype of neutrophil recovery was enriched in patients with grade 3 (73%) and especially grade 4 ICAHT (100%). Severe ICAHT was also associated with coincident multilineage cytopenias, resulting in increased transfusion requirements for both platelets (85% vs. 21%, p<0.0001) and red blood cells (86% vs. 41%, p<0.0001). In terms of management of hematotoxicity, the severe ICAHT group more commonly received G-CSF (72% vs. 44%, p=0.01), TPO mimetics (12% vs. 2%, p<0.0001) and hematopoietic stem cell boosts (6% vs. 0.2%, p<0.0001). Importantly, patients with severe ICAHT displayed a significantly increased rate of severe infections (49% vs. 13%, p<0.0001, Fig. 1a) and severe bacterial infections (36% vs. 8%, p<0.0001). This translated into a markedly increased 1-year NRM rate (14% vs. 4.5%, logrank p<0.0001, Fig. 1b), which was primarily attributed to fatal infections of fungal or bacterial origin. Of note, the ICAHT grading showed superior discrimination for severe infections (C-index 0.73, 95%CI: 0.67-0.78) compared to CTCAE grading (C-index 0.55, n.s.). Prolonged hospitalization was noted in case of severe ICAHT (median 21 vs. 16 days, p<0.0001) and intensive care admission was more common (23% vs. 4%, p<0.001). Finally, we observed inferior PFS (1-year PFS 35% vs. 51%, median 4 vs. 14 months, p<0.0001) and inferior OS (1-year OS 52% vs. 73%, median 12 months vs. not-reached, p<0.0001) in the patients that developed severe ICAHT. Conclusions: These data highlight the clinical relevance of the novel EHA/EBMT ICAHT grading system. Importantly, ICAHT severity was closely associated with transfusion dependence, increased infection incidence, and adverse treatment outcomes with high NRM. Taken together, these findings argue for reporting ICAHT grades in clinical trials evaluating established and novel CAR constructs.

Fever with Significant Procalcitonin Increase Following Gemtuzumab Ozogamicin Infusion in Hematologic Malignancy Patients without Evidence of Infection

In patients diagnosed with hematologic malignancies, including acute myeloid leukemia (AML), infections remain a major cause of non-relapse mortality. The accurate detection and management of infections during the treatment of these diseases are crucial for successful outcomes. Procalcitonin (PCT) has been proposed as a valuable tool for identifying severe bacterial infections, even in patients with hematologic malignancies. Gemtuzumab ozogamicin (GO), a humanized anti-CD33 monoclonal antibody conjugated to calicheamicin, is used in certain subsets of AML patients, such as core binding factor (CBF) leukemia and AML with favorable-risk, as well as in cases of refractory AML. However, GO administration comes with its own set of risks, including liver dysfunction, veno-occlusive disease (VOD), bone marrow suppression, bleeding, and infusion reactions. Among these reactions, those causing high fever and shivering can be particularly challenging to differentiate from sepsis or severe infections. Nevertheless, there have been no reports evaluating the utility of PCT in discriminating infections during GO-induced infusion reactions. To shed light on the impact of GO administration on PCT levels, we undertook a retrospective analysis. Over the period between 2014 and 2022, we administered GO (3.0 mg/sqm per dose) to 42 patients with hematologic malignancies, a total of 97 times (median 2 doses per patient, range 1-6 doses per patient). Of the recipients, 23 had undergone allogeneic stem cell transplantation, while 19 were non-transplant patients. Prior to GO administration, all patients received premedication comprising corticosteroids, antihistamines, and acetaminophen. Among the 97 instances of GO administration, 40 (41.2%) resulted in fever (≥37.5 ℃) within 24 hours. For 19 cases, we conducted a complete set of PCT measurements and blood cultures within 24 hours of GO administration and analyzed the PCT levels and clinical parameters. These 19 cases corresponded to 19 individual patients, of whom nine had CBF leukemia, including t(8;21) AML or inv(16) AML, and ten had non-CBF leukemia. Out of these patients, 12 experienced fever (≥37.5 ℃), while seven did not. The findings indicated that patients with fever (≥37.5 ℃) exhibited significantly higher PCT levels compared to afebrile patients (p=0.018). Furthermore, PCT levels showed a significant positive correlation with C-reactive protein levels (p=0.003). However, among the 19 patients, only one patient with a positive PCT result had a documented infection identified through blood cultures or imaging studies.Other factors, such as patient gender (p=0.467), underlying disease (p=0.224), disease remission status at GO administration (p=0.492), transplant status (p=0.556), and the number of GO administrations (p=0.906), did not significantly influence PCT levels. It is essential to acknowledge that this analysis is based on a limited number of cases from a single institution. Nevertheless, approximately 40% of patients experienced fever within 24 hours of GO administration, despite receiving premedication.Furthermore, the presence of fever after GO administration was associated with a significant increase in PCT levels, even in the absence of identifiable infection. This raises the possibility of false positives for PCT in the context of GO-induced infusion reactions, underscoring the need for cautious interpretation of PCT values for infection differentiation in patients undergoing regimens that include GO. Further research with larger patient cohorts is warranted to validate these findings and improve our understanding of the implications of PCT measurements in this clinical setting.

Challenges of Antibiotic Formulations and Administration in the Treatment of Bloodstream Infections in Children Under Five Admitted to Kisantu Hospital, Democratic Republic of Congo.

Severe bacterial infections in children need prompt, appropriate antibiotic treatment. We report challenges observed within a prospective, cohort study on antibiotic efficacy in non-typhi Salmonella bloodstream infection (NCT04850677) in Kisantu district hospital (Democratic Republic of Congo). Children (aged >28 days to <5 years) admitted with suspected bloodstream infection (August 1, 2021 through July 31, 2022) were enrolled and followed until day 3 or discharge for non-typhi Salmonella patients. Antibiotics were administered to 98.4% (1,838/1,867) of children, accounting for 2,296 antibiotic regimens (95.7% intravenous, 4.3% oral). Only 78.3% and 61.8% of children were, respectively, prescribed and administered antibiotics on the admission day. At least one dose was not administered in 3.6% of children, mostly because of mismatch of the four times daily cefotaxime schedule with the twice-daily administration rounds. Inappropriate intravenous administration practices included multidose use, air-venting, and direct injection instead of perfusion. There was inaccurate aliquoting in 18.0% (32/178) of intravenous ciprofloxacin regimens, and thus administered doses were >16% below the intended dose. Dosing accuracy of oral suspensions was impaired by lack of instructions for reconstitution, volume indicators, and/or dosing devices. Adult-dose tablets were split without/beyond scoring lines in 84.4% (27/32) of tablets. Poor availability and affordability of age-appropriate oral formulations contributed to low proportions of intravenous-to-oral switch (33.3% (79/237) of non-typhi Salmonella patients). Other quality issues included poor packaging, nonhomogeneous suspensions, and unsafe water for reconstitution. In conclusion, poor antibiotic products (no age-appropriate formulations, poor quality and access), processes (delayed prescription/administration, missed doses), and practices (inaccurate doses, [bio]safety risks) must be urgently addressed to improve pediatric antibiotic treatment.

Case of left hip acute pediatric septic arthritis - polymicrobial etiology

Septic arthritis is a true orthopedic emergency, involving a severe bacterial, viral, or fungal joint infection that triggers inflammation and the degeneration of joint tissues. It typically affects joints such as the knee, hip, shoulder, or wrist. Early diagnosis and treatment are crucial to avoid long-term complications. Herein, we describe the case of an 8-year-old male patient who presented with complaints of spontaneous onset of hip pain and an abnormal gait. The patient was diagnosed with left hip septic arthritis and underwent a left hip arthrotomy under general anesthesia (GA). The patient was administered intravenous antibiotics for 21 days while being kept on non-weight-bearing mobilization. After 3 weeks, the patient's intravenous antibiotics were switched to oral antibiotics for the next 3 weeks. On the second follow-up visit, the patient showed significant improvement, with laboratory findings within normal limits.

Applications of nanomaterials as treatments and diagnostic biosensors in microbial infections

AbstractMicrobial infection is a major medical problem that seriously threatens public health. The abuse of antibiotics that help evolve the emergence of new drug‐resistance mechanisms has led to the wide‐spread and fast expansion of drug‐resistant bacteria, ultimately evolving into superbugs. This significantly impairs the timely and effective treatment of infections, thus threatening global human well‐being. Not all are pessimistic. Nanomaterials have emerged as an innovative choice. Due to their unique physical and chemical properties, superior bactericidal effects, and high biocompatibility, nanomaterials may help eradicate drug‐resistant bacteria to achieve complete remission of infectious diseases. As biological materials, nanomaterials can also improve the efficacy of existing drugs and treatments and even facilitate diagnostic efficiency. In this review, we aim to comprehensively summarize the antibacterial properties of different kinds of nanomaterials and their applications in other spheres related to treating infectious diseases (targeted therapy, phototherapy, vaccine development, and microbial diagnosis). We highlight the latest advances of nanomaterials in treating infectious diseases in different body systems. Finally, we conclude by discussing the weaknesses of currently available materials and unresolved scientific problems, which may provide insights into the development of approved agents that adequately overcome the notorious drug resistance and thereby provide unprecedented discoveries to improve treatments of the most severe bacterial infections.

Discovery of Alkaloid Quinazolone‐Derived Imidazolenones with Novel Structural Scaffolds of Multitargeting Antibacterial Potential

Comprehensive SummaryAlkaloids are one of the prominent members in the development of new antimicrobial agents. This work discovered a class of alkaloid quinazolone‐derived imidazolenones as novel structural type of antibacterial agents with large potential to treat severe bacterial infections in the agricultural and food field. Preliminary bioactive assay displayed that some of the prepared compounds exhibited good inhibition against the tested strains, and cyclohexylimidazole‐derived 7‐fluoroquinazolone 22a (MIC = 0.002 mmol/L) exhibited a 12.5‐fold stronger inhibition than norfloxacin against Escherichia coli ATCC 25922. Further studies revealed that compound 22a not only possessed the ability of rapid bactericidal property and low propensity to develop resistance but also showed low cytotoxic effects toward red blood cells. The preliminary mechanism exploration indicated that compound 22a could cause membrane damage by disrupting bacterial membrane as well as depolarizing the cell membrane. Moreover, compound 22a could insert into DNA, which might hinder the replication of DNA. Molecular docking suggested that compound 22a could bind to gyrase and topoisomerase, which might be due to the suppressed expression of related genes. Meanwhile, compound 22a could disorder the metabolism and stimulate the production of reactive oxygen species to affect bacterial growth. The series of investigations suggested the promise of alkaloid quinazolone‐derived imidazolenones as novel multitargeting antibacterial candidates for treatment of bacterial infections.

Incidence and risk factors of neonatal bacterial infections: a community-based cohort from Madagascar (2018–2021)

BackgroundFew studies on neonatal severe bacterial infection are available in LMICs. Data are needed in these countries to prioritize interventions and decrease neonatal infections which are a primary cause of neonatal mortality. The BIRDY project (Bacterial Infections and Antimicrobial Drug Resistant among Young Children) was initially conducted in Madagascar, Senegal and Cambodia (BIRDY 1, 2012–2018), and continued in Madagascar only (BIRDY 2, 2018–2021). We present here the BIRDY 2 project whose objectives were (1) to estimate the incidence of neonatal severe bacterial infections and compare these findings with those obtained in BIRDY 1, (2) to identify determinants associated with severe bacterial infection and (3) to specify the antibiotic resistance pattern of bacteria in newborns.MethodsThe BIRDY 2 study was a prospective community-based mother and child cohort, both in urban and semi-rural areas. All pregnant women in the study areas were identified and enrolled. Their newborns were actively and passively followed-up from birth to 3 months. Data on clinical symptoms developed by the children and laboratory results of all clinical samples investigated were collected. A Cox proportional hazards model was performed to identify risk factors associated with possible severe bacterial infection.FindingsA total of 53 possible severe bacterial infection and 6 confirmed severe bacterial infection episodes were identified among the 511 neonates followed-up, with more than half occurring in the first 3 days. For the first month period, the incidence of confirmed severe bacterial infection was 11.7 per 1,000 live births indicating a 1.3 -fold decrease compared to BIRDY 1 in Madagascar (p = 0.50) and the incidence of possible severe bacterial infection was 76.3, indicating a 2.6-fold decrease compared to BIRDY 1 in Madagascar (p < 0.001). The 6 severe bacterial infection confirmed by blood culture included 5 Enterobacterales and one Enterococcus faecium. The 5 Enterobacterales were extended-spectrum β-lactamases (ESBL) producers and were resistant to quinolones and gentamicin. Enterococcus faecium was sensitive to vancomycin but resistant to amoxicillin and to gentamicin. These pathogns were classified as multidrug-resistant bacteria and were resistant to antibiotics recommended in WHO guidelines for neonatal sepsis. However, they remained susceptible to carbapenem. Fetid amniotic fluid, need for resuscitation at birth and low birth weight were associated with early onset possible severe bacterial infection.ConclusionOur results suggest that the incidence of severe bacterial infection is still high in the community of Madagascar, even if it seems lower when compared to BIRDY 1 estimates, and that existing neonatal sepsis treatment guidelines may no longer be appropriate in Madagascar. These results motivate to further strengthen actions for the prevention, early diagnosis and case management during the first 3 days of life.

Optimizing the formulation variables for encapsulation of linezolid into polycaprolactone inhalable microspheres using double emulsion solvent evaporation

Inhaled antibiotics delivered through dry powder inhalers (DPIs) effectively treat severe bacterial infections by directly targeting the lungs. Our study focused on developing inhalable dry powder microspheres of linezolid (LNZ) using biodegradable polycaprolactone (PCL) polymer. The LNZ-PCL microspheres were fabricated using a double emulsification solvent evaporation method. Optimization of formulation parameters was performed using a factorial design. Evaluation of the microspheres included size, shape, drug loading, entrapment efficiency, aerosolization, and drug release. The morphological analysis confirmed spherical-shaped rough particles within the inhalable size range. The encapsulation efficiency was determined to be 52.84%, indicating successful drug incorporation. Aerosolization efficiency was significantly enhanced when LNZ-PCL microspheres were combined with lactose as a carrier, achieving a fine particle fraction (FPF) value of 70.90%. In-vitro dissolution studies demonstrated sustained drug release for over 24 h under lung pH conditions. Overall, our study highlights the potential of inhalable LNZ-PCL microspheres as a targeted approach for treating pulmonary tuberculosis. Further research and in-vivo studies are needed to validate their effectiveness in life-threatening bacterial infections.

Systemic Inflammatory Status of Patients with Obstructive Sleep Apnea Syndrome and the Predictive Value of Heparin-Binding Protein.

Objective: To investigate the alteration of the systemic inflammatory status of patients with obstructive sleep apnea syndrome (OSAS) and the predictive value of heparin-binding protein (HBP) for OSAS. Methods: Patients with OSAS who were hospitalized in our hospital from 2020 January to 2022 December and diagnosed by polysomnography (PSG) (OSAS group, n = 79) were retrospectively studied and their relevant examination findings and demographic characteristics were recorded. Sex- and age-matched non-OSAS patients hospitalized at the same time were selected as the control group (control group, n = 28). Differences in peripheral blood neutrophil counts, lymphocyte counts, neutrophil-to-lymphocyte ratio (NLR), procalcitonin (PCT), and HBP were compared between the 2 groups. The predictive value of these markers for OSAS was analyzed using the receiver operating characteristic curve, and independent risk factors for OSAS were determined using logistic regression analysis. Peripheral blood was drawn from all patients in the fasting state of the morning. Results: The number of peripheral blood neutrophils, lymphocytes, and HBP was higher in the OSAS group than in the control group, and the differences were statistically significant (P all <.05), while the differences in NLR and PCT between the 2 groups were not statistically significant (P all >.05). Plasma HBP level had an area under the curve (AUC) of 0.79 (P < .0001) in determining OSAS, with a sensitivity of 80.49% and a specificity of 70.83% and the best cutoff value was >10.73 ng/ml. Combining body mass index (BMI), neutrophil, lymphocyte, and HBP improved the predictive value of OSAS with an AUC of 0.89 (P < .0001), a sensitivity of 80.49%, and a specificity of 87.50%. Logistic regression analysis showed that both BMI and HBP were independent risk factors for OSAS (PBMI < .001, PHBP < .01), while neutrophils and lymphocytes were not (P all >.05). Conclusions: This is the first study to objectively examine HBP in OSAS patients, and HBP is an independent risk factor that may serve as a diagnostic biomarker in OSAS. Patients with OSAS have an altered systemic inflammatory state and may be more prone to severe bacterial infections.

Oral bioavailability and egg drug residue of lincomycin in laying hens after different treatment

Lincomycin (LCM) is an antibiotic used to treat severe bacterial infections in livestock and companion animals. In this study, we aimed to investigate the oral bioavailability of LCM with PK data after IV and PO administration and to compare differences in drug residue patterns in eggs. To ensure food safety, an additional study on egg residue was conducted using 3 different commercial LCM drugs. For bioavailability study, laying hens were divided into oral and intravenous (n=8/group) groups and received single dose (10 mg/kg) of LCM. The limits of quantification for LCM were 0.729 μg/mL and 0.009 mg/kg in plasma and eggs, respectively. The oral group exhibited a significantly lower average serum drug concentration than the IV group, with a bioavailability of 2.6%. Furthermore, the egg residue profiles confirmed reduced systemic drug exposure after oral administration. For the commercial LCM drug egg residue experiment, laying hens were divided into low- and high-dose groups (n=12/group) for each drug and treated with the recommended dosage and administration method for each respective drug. The eggs were collected and analyzed until 14 d after the last drug treatment. Despite differences in the LCM content and formulation among commercial drugs, all the tested commercial drugs showed average concentrations below the MRL in eggs within approximately 3 d after the last drug treatment. In this study, we have confirmed that LCM has a low oral absorption rate in laying hens, and this was consistent with the findings from the egg residue profiles. Further studies are requested to elucidate the exact reasons for evidently low oral drug absorption in laying hens.

Clinical features and mutational analysis of X-linked agammaglobulinemia patients in Malaysia.

Bruton's tyrosine kinase (BTK) is a cytoplasmic protein involved in the B cell development. X-linked agammaglobulinemia (XLA) is caused by mutation in the BTK gene, which results in very low or absent B cells. Affected males have markedly reduced immunoglobulin levels, which render them susceptible to recurrent and severe bacterial infections. Methods: Patients suspected with X-linked agammaglobulinemia were enrolled during the period of 2010-2018. Clinical summary, and immunological profiles of these patients were recorded. Peripheral blood samples were collected for monocyte BTK protein expression detection and BTK genetic analysis. The medical records between January 2020 and June 2023 were reviewed to investigate COVID-19 in XLA. Twenty-two patients (from 16 unrelated families) were molecularly diagnosed as XLA. Genetic testing revealed fifteen distinct mutations, including four splicing mutations, four missense mutations, three nonsense mutations, three short deletions, and one large indel mutation. These mutations scattered throughout the BTK gene and mostly affected the kinase domain. All mutations including five novel mutations were predicted to be pathogenic or deleterious by in silico prediction tools. Genetic testing confirmed that eleven mothers and seven sisters were carriers for the disease, while three mutations were de novo. Flow cytometric analysis showed that thirteen patients had minimal BTK expression (0-15%) while eight patients had reduced BTK expression (16-64%). One patient was not tested for monocyte BTK expression due to insufficient sample. Pneumonia (n=13) was the most common manifestation, while Pseudomonas aeruginosa was the most frequently isolated pathogen from the patients (n=4). Mild or asymptomatic COVID-19 was reported in four patients. This report provides the first overview of demographic, clinical, immunological and genetic data of XLA in Malaysia. The combination of flow cytometric assessment and BTK genetic analysis provides a definitive diagnosis for XLA patients, especially with atypical clinical presentation. In addition, it may also allow carrier detection and assist in genetic counselling and prenatal diagnosis.

Insights into Facilitated Subcutaneous Immunoglobulin Use in Patients with Secondary Immunodeficiency Diseases: A FIGARO Subgroup Analysis.

The Facilitated Immunoglobulin Administration Registry And Outcomes (FIGARO) Study was a European, multicenter, prospective, observational study conducted across Europe designed to provide insights on the clinical use and tolerability of facilitated subcutaneous immunoglobulin (fSCIG). Data herein are reported for the cohort of patients with secondary immunodeficiency (SID), with a subgroup analysis by age. The SID cohort included 31 patients: 1 pediatric, 15 adult, and 15 older adult patients. Over the 36-month observation period, the median monthly dose of fSCIG (30 g) and median monthly infusion volume per patient (300 mL) remained constant in both adult-age cohorts. Serum trough levels tended to increase over time. Most patients required only one infusion site and could receive the full dose every 3-4 weeks. There was a trend toward self-administration at home. In the adult group, infusion site inflammation and headache were reported at the inclusion visit (n = 1 each), with no adverse drug reactions reported at any of the follow-up visits. No acute severe bacterial infections were reported during the study follow-up. These results demonstrate the feasibility and tolerability of fSCIG use in patients with SID and the flexibility of administration settings including self-administration at home in patients aged ≥65 years.

A statistical genomics framework to trace bacterial genomic predictors of clinical outcomes in Staphylococcus aureus bacteremia

Outcomes of severe bacterial infections are determined by the interplay between host, pathogen, and treatments. While human genomics has provided insights into host factors impacting Staphylococcus aureus infections, comparatively little is known about S.aureus genotypes and disease severity. Building on the hypothesis that bacterial pathoadaptation is a key outcome driver, we developed a genome-wide association study (GWAS) framework to identify adaptive mutations associated with treatment failure and mortality in S.aureus bacteremia (1,358 episodes). Our research highlights the potential of vancomycin-selected mutations and vancomycin minimum inhibitory concentration (MIC) as key explanatory variables to predict infection severity. The contribution of bacterial variation was much lower for clinical outcomes (heritability <5%); however, GWASs allowed us to identify additional, MIC-independent candidate pathogenesis loci. Using supervised machine learning, we were able to quantify the predictive potential of these adaptive signatures. Our statistical genomics framework provides a powerful means to capture adaptive mutations impacting severe bacterial infections.

Comparing the Phylogenetic Distribution of Multilocus Sequence Typing, Staphylococcal Protein A, and Staphylococcal Cassette Chromosome Mec Types in Methicillin-Resistant Staphylococcus Aureus (MRSA) in Korea from 1994 to 2020.

Staphylococcus aureus (S. aureus) bacteremia is one of the most frequent and severe bacterial infections worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is a serious human pathogen that can cause a wide variety of infections. Comparative genetic analyses have shown that despite the existence of a vast number of genotypes, genotypes are restricted to certain geographical locations. By comparing multilocus sequence typing (MLST) and SCCmec types from 1994 to 2020, the present study intended to discover which genotype genes were related to MRSA infections. MLST, Staphylococcus aureus protein A (spa), and SCCmec typings were performed to determine their relationship during those years. Results revealed that MRSA isolates in the Republic of Korea were distributed among all major staphylococcal cassette chromosome mec (SCCmec) types. The majority of SCCmec isolates belonged to SCCmec type II and type IV. The majority of MLST had the sequence type (ST) 72, 239, 8, or 188. By contrast, minorities belonged to ST22 (SCCmec IV), ST772 (SCCmec V), and ST672 (SCCmec V) genotypes. The SCCmec type was determined for various types. The spa type was dispersed, seemingly regardless of its multidrug resistance property. The MLST type was found to be similar to the existing typical type. These results showed some correlations between resistance characteristics and types according to the characteristics of the MLST types distributed, compared to previous papers. Reports on genotype distribution of MLST and SCCmec types in MRSA are rare. These results show a clear distribution of MLST and SCCmec types of MRSA from 1994 to 2020 in the Republic of Korea.

USEFULNESS OF PROCALCITONIN AS A BIOMARKER IN BURN PATIENTS PLASTIC SURGERYDEPARTMENT, MOHAMMED VI UNIVERSITYHOSPITAL, MARRAKECH, MOROCCO

Infection is the most common complication and cause of death in patients suffering burnsinjuries.These patients are susceptible to infection and burn wound sepsis secondary to the alterations in their physiology .Procalcitonin is an inflammatory biomarkers , the serum concentration of which increases specifically during bacterial infections. For a burn patient, its sometimes difficult to differentiate, on the basis of the clinical examination , those who suffer from an acute inflammatory syndrome from those who show the first signs of a severe bacterial infection. However, a correct diagnosis is essential for the prompt initiation of appropriate treatment . Many markers associated with an infectious state have recently been investigated. Among them , serum pro calcitonin has the best sensitivity and specificity for sepsis or other severe bacterial infections. The aim of this work is to evaluate the impact of the implementation of procalcitonin (PCT) on the management of infected patients in the burns resuscitation department of the plastic surgery department at CHU Med VI.Our study is retrospective , observational, and conducted over a period of 6 months, extending from July 1, 2022, to December 31, 2022, for 24burned patients hospitalized in the intensive care unit of the plastic surgery department .The average age of the patients was 38 years they were predominantly male with a sex ratio of about 1.5 . The average burned skin surface was 27.75% 40.3% had a deepening with signsof skin infection all patients CRP was high 60% had a fever higher than 38.5 13.3% had a stay in the surgical resuscitation department and were discharged a PCT returned positive in 16.6% of patientsthe determination was repeated in 4 patients after 24h returned Negatif 26.6% had a positive bacteriological examination and 40% of patients received antibiotic therapy .PCT maybe used as a useful bio marker for the early diagnosis of burn sepsis in adults, and maybe combined with other diagnostic indexes to further improve the sensitivity and specificity. Thus, even throughout study provides us with the knowledge that the PCT maybe a helpful sepsis biomarker in burned patients, the findings should be viewd with caution.

Detection of NCF-2 Gene Expression in Egyptian Children with Chronic Granulomatous Disease

Abstract Background Chronic granulomatous disease (CGD) is a rare inherited primary immunodeficiency disorder (PID) which is characterized by enhanced susceptibility to severe bacterial and fungal infections. It results from defects in one of the five polypeptide subunits of the nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) complex; CYBB (gp91-phox), NCF-1 (p47phox), CYBA (p22-phox), NCF-2 (p67-phox), or NCF-4 (p40-phox) with a resulting failure of the phagocytes in generating a variety of microbicidal reactive oxygen radicals during respiratory burst. Objectives This work intended to diagnose autosomal recessive (AR)-type of CGD by detection of NCF-2 gene expression using real time RT-PCR as a cheaper diagnostic method for CGD subtypes categorization among CGD children. Subjects and methods This case-control study was conducted on 15 children provisionally diagnosed as CGD patients by the use of dihydrorhodamine (DHR) stimulation index (Group I) in addition to 12 mothers and 8 fathers of the studied patients (Group IIa and IIb respectively) to detect the genetic mutations in carriers, if any, and 14 apparently healthy children as a control group (Group III). In the present study, cases with a fold change of NCF-2 gene expression less than 0.67 were considered defective for NCF-2 gene expression. At this cut-off value, from our molecularly studied subjects, 2 CGD cases and one mother showed underexpression of NCF-2 gene. In conclusion, defect in the NCF-2 gene, which encodes gp67-phox of the oxidase enzyme could be done by RT-PCR as a cheaper diagnostic method for CGD without the need to use complex and expensive methodologies such as northern blot, or genomic DNA sequencing.