Cancer-Associated Thrombosis: Pathophysiology, Laboratory Assessment, and Current Guidelines.

Dysregulated hemostasis in cancer patients is associated with various clinical conditions, from thromboembolic complications to disseminated intravascular coagulation. Despite the well-established association between cancer and thromboembolic complications, the mechanisms involved are not completely elucidated. There are several predisposing factors in cancer for increased thrombus generation, such as immobilization and chemotherapy. The term cancer-associated thrombosis (CAT) has been introduced to describe the close bidirectional relationship between cancer and thromboembolic events. Conventional coagulation tests (PT/aPTT) are more accurate in detecting a hypocoagulable rather than a hypercoagulable state; thus, their contribution to CAT management is limited. Traditionally, D-dimer levels have been the most common laboratory study for the evaluation of thrombotic risk. However, D-dimer levels only display a snapshot of the coagulation cascade, and they cannot provide a dynamic evaluation of evolving clot formation. Non-conventional assays, such as viscoelastic methods and microparticle formation are promising tools for the identification of patients at risk for developing CAT. Recent guidelines from the American Society of Clinical Oncology counsel against the estimation of thrombotic risk through a single test and recommend the use of scoring systems that take into account several risk factors. The present review outlines the current insights into the pathophysiological mechanisms of CAT and provides a comprehensive review of the latest advances in the laboratory assessment of CAT and the recent guidelines for the management of patients at risk for developing thromboembolic complications.

Post-Discectomy Infection: A Critical Review and Suggestion of a Management Algorithm.

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42-73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2-4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management.

Diagnosis, Treatment, and Outcome of Coccidioidal Osseous Infections: A Systematic Review.

Extrapulmonary infections by Coccidioides spp., though rare, can occur via dissemination, affecting singular or multiple sites, including the skin and musculoskeletal system. Skeletal involvement often manifests as osteomyelitis, particularly in the axial skeleton. The present systematic review evaluates all documented cases of skeletal coccidioidomycosis to assess the diagnostic and treatment strategies alongside the outcomes, drawing insights from an analysis of 163 verified cases. A systematic review following PRISMA guidelines identified all studies reporting skeletal infections by Coccidioides spp. up to 2023 from the PubMed and Scopus databases. Eligible studies evaluated osteoarticular infections from Coccidioides spp. Data extraction included demographics, microbiological data, diagnostic methods, and treatment outcomes. Of the 501 initially identified records, a total of 163 patients from 69 studies met the inclusion criteria. Most cases were from the USA, predominantly males, while the median age of the population was 36 years. Diabetes mellitus was the common comorbidity (14.7%). C. immitis was the most prevalent pathogen. The spine and hand were common sites of infection (17.5% and 15.1%, respectively). Osteomyelitis by Coccidioides spp. was diagnosed, in most cases, by positive cultures (n = 68; 41.7%), while, in 49 (30.9%), both the histological examination and cultures yielded the fungus. Surgical debridement was performed in 80.9% of cases. A total of 118 (72.3%) patients were treated with monotherapy, while combination therapy with two or more antifungal agents was reported in 45 (17.7%). Amphotericin B (either liposomal or deoxycholate) was the most commonly given agent as monotherapy in 51 (31.2%) patients, while 30 (18.4%) patients received itraconazole as monotherapy. The rate of infection's resolution was higher in patients undergoing surgical debridement (79.5%), compared to those treated only with antifungal agents (51.6%, p = 0.003). Treatment outcomes showed complete resolution in 74.2% of patients, with a mortality rate of 9.2%. Coccidioidal osseous infections present diagnostic and therapeutic challenges. Surgical intervention is often necessary, complementing antifungal therapy. Vigilance for Coccidioides spp. infections, especially in regions with endemicity, is crucial, particularly when bacterial cultures yield negative results.

Rotational Thromboelastometry as a Diagnostic Tool for Persistent Infection in Two-Stage Exchange Arthroplasty.

Background/Objectives: There is a lack of reliable biomarkers for diagnosis of infection eradication prior to second-stage reimplantation in two-stage exchange arthroplasty for periprosthetic joint infections (PJIs). The aim of this study was to assess the diagnostic accuracy of rotational thromboelastometry (ROTEM) for persistent infection in two-stage exchange arthroplasties. Methods: A pilot, retrospective analysis was performed including 70 patients who underwent a two-stage exchange arthroplasty for PJI. They were categorized as patients without (n = 64) or patients with persistent infection (n = 6) prior to reimplantation. Definition of persistent infection prior to reimplantation was based on the 2018 ICM criteria. Conventional coagulation biomarkers and ROTEM parameters were compared between groups. Results: Higher FIBTEM MCF values were associated with persistent infection (odds ratio [OR], 1.30, 95% confidence interval [CI], 1.04-1.63; p = 0.020), and FIBTEM MCF had the highest diagnostic accuracy for persistent infection prior to second-stage reimplantation (AUC, 0.907; 95% CI, 0.812-1.000). A cut-off value ≥ 18 mm for FIBTEM MCF was found to have 100.0% sensitivity and 73.4% specificity for diagnosing persistent infection prior to second-stage reimplantation. Moreover, the diagnostic accuracy of FIBTEM MCF was higher than that of fibrinogen levels (p = 0.036) and D-dimer (p = 0.006). Conclusions: Our findings indicate that ROTEM parameters have the potential to identify persistent infections before reimplantation in two-stage exchange arthroplasties for PJI. Such coagulation biomarkers could provide guidance regarding the optimal timing for reimplantation. Further studies in larger populations are warranted to validate the diagnostic accuracy of ROTEM parameters for persistent PJI.

Candida auris Infection, a Rapidly Emerging Threat in the Neonatal Intensive Care Units: A Systematic Review.

(1) Background: In recent years, a global epidemiological shift in candidemia has been observed, marked by the emergence of resistant non-albicans Candida species. Candida auris, in particular, has become a significant global concern, causing infections in both pediatric and adult populations within healthcare settings. Despite its widespread impact, there is a limited understanding of the clinical course and transmission dynamics of neonatal systemic Candida auris infections, hindering effective prevention and management. This study focused on the epidemiologic data, the clinical presentation, risk factors, and outcome of C. auris infection in neonatal population. (2) Methods: A systematic review of the literature using PubMed and Scopus databases until December 2023 was conducted. (3) Results: A total of 24 relevant studies were identified, encompassing 476 documented cases of Candida auris infection in neonates. Prematurity emerged as a primary risk factor, alongside total parenteral nutrition, central line insertion, mechanical ventilation, and prior broad-spectrum antibiotic use. The mortality rate reached approximately 42%, with therapeutic details sparingly reported in 12% of cases. Treatment strategies varied, with amphotericin B predominantly used as monotherapy, while combination antifungal agents were used in 44% of cases. Notably, 97.4% of cases exhibited fluconazole resistance, and 67.1% showed resistance to amphotericin B. Limited data were available on resistance to other antifungal agents. (4) Conclusions: Despite the rarity of neonatal Candida auris infections, their global occurrence necessitates comprehensive preparedness in patient care. A deeper understanding of Candida auris pathogenesis is crucial for developing effective strategies to control and prevent neonatal infections caused by this pathogen.

The effects of pathogen reduction technology on apheresis platelet concentrates stored in PAS.

BACKGROUND: The impact of pathogen reduction technology (PRT) such as Mirasol, and the effect of platelet additive solutions (PAS) on the activity and hemostatic profile of transfused apheresis platelets remain largely unknown. The aim of this study was to assess the in vitro hemostatic and metabolic profile of Mirasol treated platelets in PAS during a 7-day storage period. MATERIAL AND METHODS: Ten split bags containing apheresis platelets stored in PAS were split into two groups; control platelets (No.=10 units) and PRT-treated platelets (No.=10 units). In vitro evaluation of the platelet components was performed on the 1st, 3rd, 5th, and 7th days of the storage period. Several metabolic parameters including pH, glucose, and lactate levels were evaluated, while assessment of their hemostatic capacity was performed using light transmission aggregometry (LTA) and viscoelastic studies such as rotational thromboelastometry (ROTEM) and thromboelastography (TEG). Last, Annexin V levels were measured though flow cytometry for evaluation of platelet activation. RESULTS: Clot strength, as reflected by the maximum clot firmness (MCF) and the maximum amplitude (MA) parameters of the viscoelastic studies was significantly decreased in the PRT-treated platelets compared to the control platelets (p<0.05). Clot strength based on MCF and MA values was also found to be decreasing over storage time in PRT-treated platelets (p<0.001), while this was not evident in control platelets. Moreover, the comparison between pH, glucose, and lactate levels were indicative of increased metabolic activity in PRT-treated platelets compared to control platelets (p<0.001). Last, Annexin-V was significantly higher in PRT-treated platelets compared to control platelets on the 7th day of the storage period (p<0.001). DISCUSSION: The results of this study indicate that increased PSL induced by PRT treatment leads to a decreased in vitro platelet hemostatic efficacy and increased metabolic activity. However, the clinical impact of these alternations needs further investigation.

From Clinical Suspicion to Diagnosis: A Review of Diagnostic Approaches and Challenges in Fungal Keratitis.

Fungal keratitis is a relatively rare yet severe ocular infection that can lead to profound vision impairment and even permanent vision loss. Rapid and accurate diagnosis plays a crucial role in the effective management of the disease. A patient's history establishes the initial clinical suspicion since it can provide valuable clues to potential predisposing factors and sources of fungal exposure. Regarding the evaluation of the observed symptoms, they are not exclusive to fungal keratitis, but their timeline can aid in distinguishing fungal keratitis from other conditions. Thorough clinical examination of the affected eye with a slit-lamp microscope guides diagnosis because some clinical features are valuable predictors of fungal keratitis. Definitive diagnosis is established through appropriate microbiological investigations. Direct microscopic examination of corneal scrapings or biopsy specimens can assist in the presumptive diagnosis of fungal keratitis, but culture remains the gold standard for diagnosing fungal keratitis. Advanced molecular techniques such as PCR and MALDI-ToF MS are explored for their rapid and sensitive diagnostic capabilities. Non-invasive techniques like in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT) are useful for real-time imaging. Every diagnostic technique has both advantages and drawbacks. Also, the selection of a diagnostic approach can depend on various factors, including the specific clinical context, the availability of resources, and the proficiency of healthcare personnel.

Racial Disparities in Infliximab Efficacy for Ulcerative Colitis: Evidence Synthesis and Effect Modification Assessment.

An increasing amount of research explores the role of race in clinical phenotypes and outcomes in ulcerative colitis (UC). We aimed to investigate racial differences in infliximab (IFX) treatment efficacy in UC. We used aggregate data from IFX trials and evidence synthesis methods to generate race-specific efficacy estimates. Then, we tested the effect modification by race by comparing the race-specific estimates derived from independent evidence syntheses. We computed ratios of relative risks (RRRs) and performed tests of statistical interaction. We analyzed data from five randomized, placebo-controlled trials evaluating IFX as induction and maintenance therapy for adults with moderate-to-severe UC (875 participants; 45% Asians). We found no substantial evidence of racial differences concerning the efficacy of IFX in inducing clinical response (RRR = 0.89, 95% CI: 0.66-1.20; p = 0.44), clinical remission (RRR = 0.58, 95% CI: 0.24-1.44; p = 0.24), and mucosal healing (RRR = 0.99, 95% CI: 0.69-1.41; p = 0.95), or maintaining clinical remission (RRR = 0.81, 95% CI: 0.46-1.42; p = 0.45) and mucosal healing (RRR = 0.84, 95% CI: 0.48-1.46; p = 0.53), between Asian and Caucasian populations. Future clinical studies should expand the participation of racial minorities to comprehensively assess potential racial differences in the effectiveness of advanced therapies, including IFX, in the context of treating UC.

Assessment of Hemostatic Profile in Neonates with Intrauterine Growth Restriction: A Systematic Review of Literature.

Intrauterine growth restriction (IUGR) affects nearly 10 to 15% of pregnancies and is responsible for many short- and long-term adverse consequences, including hemostatic derangement. Both thrombotic and hemorrhagic events are described in the perinatal period in these neonates. The aim of this study was to systematically review the literature on the laboratory studies used to evaluate the hemostatic system of the IUGR small for gestational age neonate. We reviewed the current literature via PubMed and Scopus until September 2022. Following our inclusion/exclusion criteria, we finally included 60 studies in our review. Thrombocytopenia, characterized as hyporegenerative and a kinetic upshot of reduced platelet production due to in utero chronic hypoxia, was the main finding of most studies focusing on growth-restricted neonates, in most cases is mild and usually resolves spontaneously with the first 2 weeks of life. In regard to coagulation, growth-restricted newborns present with prolonged standard coagulation tests. Data regarding coagulation factors, fibrinolytic system, and anticoagulant proteins are scarce and conflicting, mainly due to confounding factors. As thromboelastography/rotational thromboelastometry (TEG/ROTEM) provides a more precise evaluation of the in vivo coagulation process compared with standard coagulation tests, its use in transfusion guidance is fundamental. Only one study regarding TEG/ROTEM was retrieved from this population, where no difference in ROTEM parameters compared with appropriate for gestational age neonates was found. Despite the laboratory aberrations, no correlation could be achieved with clinical manifestations of bleeding or thrombosis in the studies included. More studies are needed to assess hemostasis in IUGR neonates and guide targeted therapeutic interventions.

Contemporary tools for evaluation of hemostasis in neonates. Where are we and where are we headed?

The assessment of hemostatic disorders in neonates is crucial, but remains challenging for clinicians. Although the concept of developmental hemostasis is widely accepted among hemostasis specialists globally, it is probably under-recognized by clinicians and laboratory practitioners. In parallel with age-dependent hemostatic status maturation, comprehension of the differences between normal values is crucial for the accurate diagnosis of potential hemorrhagic and thrombotic disorders of the vulnerable neonatal population. This review outlines the basics of developmental hemostasis and the features of the available coagulation testing methods, with a focus on novel tools for evaluating the neonatal hemostatic profile. Common errors, issues, and pitfalls during the assessment of neonatal hemostasis are discussed, along with their impact on patient management. Current knowledge gaps and research areas are addressed. Further studying to improve our understanding of developmental hemostasis and its reflection on everyday clinical practice is warranted.

Thromboelastometry and prediction of in-hospital mortality in neonates with sepsis.

INTRODUCTION: This study aimed at evaluating the role of rotational thromboelastometry (ROTEM) assays in the prediction of in-hospital mortality of neonates with sepsis. METHODS: Over a 6-year period, 129 neonates with confirmed sepsis, hospitalized in our neonatal intensive care unit (NICU) were included in the study. Demographics, clinical, and laboratory data were recorded at the sepsis onset and ROTEM assays were performed. Modified neonatal multiple organ dysfunction (NEOMOD) and neonatal sequential organ failure assessment (nSOFA) were calculated simultaneously. Mortality during in-hospital stay was the main outcome measure. RESULTS: In-hospital mortality was associated with patient intense hypocoagulability expressed by lower ROTEM MCF in the INTEM assay. The INTEM MCF demonstrated the best prognostic performance for NICU mortality in septic neonates among the other ROTEM parameters but without statistical significance (area under the curve [AUC] = 0.731; 95% confidence interval [CI]: 0.593-0.869). CONCLUSION: Our results indicate that ROTEM INTEM MCF parameter has good predictive capacity for in-hospital mortality of septic neonates, similar to that of modified NEOMOD score, nSOFA score, and platelet count, highlighting the integral role of coagulation in sepsis pathophysiology. Hence, ROTEM could serve as a valuable monitoring tool to identify neonates at risk.

Assessment of hemostatic profile in neonates with necrotizing enterocolitis using Rotational Thromboelastometry (ROTEM).

BACKGROUND: This study aimed to explore the hemostatic profile of neonates with necrotizing enterocolitis (NEC) using Rotational Thromboelastometry (ROTEM) and to investigate if ROTEM parameters have the capacity to play a role in the differentiation of NEC from sepsis at the disease onset. METHODS: This observational study included 62 neonates (mean gestational age 31.6 weeks and mean birth weight 1620g) hospitalized in a neonatal intensive care unit. The neonates were categorized in three groups: neonates with NEC (Bell stage II and above), neonates with sepsis and healthy neonates and they were matched 1:1:1 with regards to gestational age, delivery mode, and sex. Clinical, laboratory data as well as measurements of ROTEM parameters at disease onset were recorded. RESULTS: ROTEM parameters differed between neonates with NEC and neonates with sepsis, indicating that NEC results in accelerated clot formation and higher clot strength compared to sepsis. The EXTEM CFT and A10 parameters demonstrated the highest diagnostic performance for NEC in terms of discrimination between NEC and sepsis (AUC, 0.997; 95% CI: 0.991-1.000 and 0.973; 95% CI: 0.932-1.000, respectively). CONCLUSIONS: Neonates with NEC manifested accelerated clot formation and higher clot strength compared to septic and healthy neonates, as these were expressed by ROTEM parameters. IMPACT: This work reports data on the hemostatic profile of neonates with necrotizing enterocolitis (NEC) using Rotational Thromboelastometry (ROTEM) and the capacity of ROTEM parameters in differentiating of NEC from sepsis at the disease onset. Neonates with NEC present acceleration of coagulation and exhibit a hypercoagulable profile, as this is expressed by ROTEM parameters, in comparison to septic and healthy neonates. ROTEM parameters demonstrated a good diagnostic capacity in differentiating NEC from sepsis at the disease onset.

Group A Streptococcus Infection in Neonatal Population: A Systematic Review of The Literature.

(1) Background: The importance of group A streptococcus (GAS) infection severity has been recognized in children and adults. However, to our knowledge, there have been no systematic reviews or pooled assessments of the incidence and outcome of invasive GAS (iGAS) disease in neonates, a potentially high-risk population. Therefore, we performed a systematic review of available data regarding the risk factors, clinical presentation, and outcome of GAS infection in neonates. (2) Methods: An electronic search of the existing literature was carried out during the period July 2023-September 2023 in the PubMed and Scopus databases, considering studies referring to GAS infection in the neonatal population. (3) Results: Overall, 39 studies met all the inclusion criteria and were included in this review, evaluating data from 194 neonates. Unfortunately, there were a lot of missing data among the retrieved studies. Our systematic review highlighted the presence of differences with regards to clinical presentation, infection sites, and outcome of GAS invasive disease between neonates with early-onset (EOS) or late-onset sepsis (LOS). Common characteristics of EOS included respiratory distress, rapid deterioration, and high mortality rate irrespective of the infection site, while rash, gastrointestinal tract symptoms, and fever appeared to be the most frequent symptoms/clinical signs and manifestations of LOS disease. The management of severe invasive iGAS disease consists mainly of specific antimicrobial treatment as well as supportive care with fluids and electrolyte supplementation, minimizing or counteracting the effects of toxins. Furthermore, a mortality rate of approximately 14% was recorded for iGAS disease in the total of all studies' neonates. (4) Conclusions: Although iGAS is a rare entity of neonatal infections, the potential severity of the disease and the rapid deterioration requires the development of quick analysis methods for the detection of GAS allowing the prompt diagnosis and administration of the indicated antibiotic treatment. Furthermore, given the exceptional risk for both the pregnant woman and the neonate, it is very important to raise awareness and create easily accessible guidelines that could facilitate the prevention and management of maternal as well as the subsequent neonatal severe iGAS disease.

Bleeding Scoring Systems in Neonates: A Systematic Review.

We conducted a systematic review aiming to summarize the data on the current hemorrhage prediction models and evaluate their potential for generalized application in the neonatal population. The electronic databases PubMed and Scopus were searched, up to September 20, 2023, for studies that focused on development and/or validation of a prediction model for bleeding risk in neonates, and described the process of model building. Nineteen studies fulfilled the inclusion criteria for the present review. Eighteen bleeding risk prediction models in the neonatal population were identified, four of which were internally validated, one temporally and one externally validated. The existing prediction models for neonatal hemorrhage are mostly based on clinical variables and do not take into account the clinical course and hemostatic profile of the neonates. Most studies aimed at predicting the risk of intraventricular hemorrhage (IVH) reflecting the fact that IVH is the most frequent and serious bleeding complication in preterm neonates. A justification for the study sample size for developing the prediction model was given only by one study. Prediction and stratification of risk of hemorrhage in neonates is yet to be optimized. To this end, qualitative standards for model development need to be further improved. The assessment of the risk of bleeding incorporating platelet count, coagulation parameters, and a set of relevant clinical variables is crucial. Large, rigorous, collaborative cohort studies are warranted to develop a robust prediction model to inform the need for transfusion, which is a fundamental step towards personalized transfusion therapy in neonates.

A Pilot Observational Study Evaluating the Diagnostic Capacity of Rotational Thromboelastometry in Periprosthetic Joint Infections.

BACKGROUND: Periprosthetic joint infections (PJIs) are associated with altered hemostatic dynamics; therefore, coagulation laboratory methods such as rotational thromboelastometry (ROTEM) may be valuable in their diagnosis. The aim of this study was to evaluate the diagnostic role of ROTEM in PJI. METHODS: A diagnostic study was conducted including 65 patients who underwent revision total hip arthroplasty or total knee arthroplasty due to PJI (30 patients) or aseptic loosening (35 patients). Preoperative laboratory evaluation included conventional coagulation studies, inflammatory markers, and ROTEM analysis. These parameters were compared between patients with PJI and patients with aseptic loosening. RESULTS: Several ROTEM parameters differed in the patients with PJI, indicating a higher coagulation potential associated with PJI. Specifically, the development of PJI was associated with higher EXTEM maximum clot firmness (MCF) (odds ratio [OR], 1.12 [95% confidence interval (CI), 1.04 to 1.20]; p = 0.001). Among the ROTEM parameters, EXTEM MCF was found to have the highest diagnostic accuracy for PJI (area under the receiver operating characteristic curve, 0.850; sensitivity, 76.6%; specificity, 91.4%), which was comparable with C-reactive protein (CRP) (p = 0.22) and erythrocyte sedimentation rate (ESR) (p = 0.65), but higher than D-dimer (p = 0.037). Moreover, the combined diagnostic accuracy of elevated EXTEM MCF and CRP was improved compared with CRP alone (p = 0.019). CONCLUSIONS: Our results indicate that ROTEM analysis might be helpful for the detection of the hemostatic derangements that are associated with the development of PJI. However, because of the small size of this pilot study, further research is needed to investigate the value of incorporating viscoelastic studies in diagnostic scores for PJI. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Optimizing Clinical Decision Making with Decision Curve Analysis: Insights for Clinical Investigators.

A large number of prediction models are published with the objective of allowing personalized decision making for diagnostic or prognostic purposes. Conventional statistical measures of discrimination, calibration, or other measures of model performance are not well-suited for directly and clearly assessing the clinical value of scores or biomarkers. Decision curve analysis is an increasingly popular technique used to assess the clinical utility of a prognostic or diagnostic score/rule, or even of a biomarker. Clinical utility is expressed as the net benefit, which represents the net balance of patients' benefits and harms and considers, implicitly, the consequences of clinical actions taken in response to a certain prediction score, rule, or biomarker. The net benefit is plotted against a range of possible exchange rates, representing the spectrum of possible patients' and clinicians' preferences. Decision curve analysis is a powerful tool for judging whether newly published or existing scores may truly benefit patients, and represents a significant advancement in improving transparent clinical decision making. This paper is meant to be an introduction to decision curve analysis and its interpretation for clinical investigators. Given the extensive advantages, we advocate applying decision curve analysis to all models intended for use in clinical practice.

Probiotic Properties and Antioxidant Activity In Vitro of Lactic Acid Bacteria.

The properties of probiotics such as lactic acid bacteria (LAB) have been widely studied over the last decades. In the present study, four different LAB species, namely Lactobacillus gasseri ATCC 33323, Lacticaseibacillus rhamnosus GG ATCC 53103, Levilactobacillus brevis ATCC 8287, and Lactiplantibacillus plantarum ATCC 14917, were investigated in order to determine their ability to survive in the human gut. They were evaluated based on their tolerance to acids, resistance to simulated gastrointestinal conditions, antibiotic resistance, and the identification of genes encoding bacteriocin production. All four tested strains demonstrated high resistance to simulated gastric juice after 3 h, and the viable counts revealed declines in cell concentrations of less than 1 log cycle. L. plantarum showed the highest level of survival in the human gut, with counts of 7.09 log CFU/mL. For the species L. rhamnosus and L. brevis, the values were 6.97 and 6.52, respectively. L. gasseri, after 12 h, showed a 3.96 log cycle drop in viable counts. None of the evaluated strains inhibited resistance to ampicillin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, or chloramphenicol. With regard to bacteriocin genes, the Pediocin PA gene was identified in Lactiplantibacillus plantarum ATCC 14917, Lacticaseibacillus rhamnosus GG ATCC 53103, and Lactobacillus gasseri ATCC 33323. The PlnEF gene was detected in Lactiplantibacillus plantarum ATCC 14917 and Lacticaseibacillus rhamnosus GG ATCC 53103. The Brevicin 174A and PlnA genes were not detected in any bacteria. Moreover, the potential antioxidant activity of LAB's metabolites was evaluated. At the same time, the possible antioxidant activity of metabolites of LAB was first tested using the free radical DDPH• (a, a-Diphenyl-ß-Picrylhydrazyl) and then evaluated with regard to their radical scavenging activity and inhibition against peroxyl radical induced DNA scission. All strains showed antioxidant activity; however, the best antioxidant activity was achieved by L. brevis (94.47%) and L. gasseri (91.29%) at 210 min. This study provides a comprehensive approach to the action of these LAB and their use in the food industry.

High prevalence of clonally related ST182 NDM-1-producing Enterobacter cloacae complex clinical isolates in Greece.

NDM-type metallo-ß-lactamase (MBL)-producing Enterobacterales remain uncommon in the European region, especially among species other than Klebsiella pneumoniae and Escherichia coli. The aim of this study was to describe epidemiological and molecular characteristics of a widespread NDM-1-producing Enterobacter cloacae complex outbreak in Greece. Over a 6-year period (March 2016-March 2022), a retrospective study was conducted in a tertiary care Greek hospital. Ninety single-patient carbapenem-non-susceptible E. cloacae complex clinical isolates were recovered consecutively. The isolates were subjected to further investigation, including antimicrobial susceptibility testing and combined disc tests for carbapenemase production, polymerase chain reaction and sequencing for resistance genes, molecular fingerprinting by pulsed-field gel electrophoresis (PFGE), plasmid profiling, replicon typing, conjugation experiments, genotyping by multi-locus sequence typing (MLST), whole-genome sequencing and phylogenetic analysis. Phenotypic and molecular testing confirmed the presence of blaNDM-1 in 47 (52.2%) of the E. cloacae complex isolates. MLST analysis clustered all but four of the NDM-1 producers into a single MLST sequence type (ST182), whereas single isolates belonged to different sequence types (ST190, ST269, ST443 and ST743). PFGE analysis revealed that ST182 isolates were clustered into a single clonal type, with three subtypes, which differed from the clonal types detected among the remaining carbapenem non-susceptible E. cloacae complex isolates identified during the study period. All ST182 blaNDM-1-carrying isolates also harboured the blaACT-16 AmpC gene, while the blaESBL, blaOXA-1 and blaTEM-1 genes were detected in most cases. In all clonal isolates, the blaNDM-1 gene was located on an IncA/C-type plasmid, and flanked upstream by an ISAba125 element and downstream by bleMBL. Conjugation experiments failed to produce carbapenem-resistant transconjugants, indicating a low dynamic for horizontal gene transfer. Application of enforced infection control measures led to the absence of new NDM-positive cases for periods of time during the survey. This study represents the largest clonal outbreak of NDM-producing E. cloacae complex in Europe.