A 74-year-old man presented with 3 days of fever and chills without gastrointestinal symptoms. Blood cultures repeatedly grew polymicrobial enteric organisms and Candida glabrata despite appropriate antimicrobials. Initial evaluation, including computed tomography abdomen/pelvis, colonoscopy, and esophagogastroduodenoscopy (EGD), was negative. Subsequent computed tomography enterography showed a proximal duodenal outpouching with surrounding inflammation and nonocclusive inferior vena cava thrombus. Repeat EGD by an advanced endoscopist identified a 15-mm duodenal diverticulum with ingested vegetable matter impaling the diverticular wall. Foreign body removal and clip closure achieved source control, with rapid clinical resolution. This case highlights endoscopic management of perforated duodenal diverticulum likely causing relapsing polymicrobial bacteremia, sepsis, and thrombosis.

Background. Pandoraea sputorum is an emerging multidrug-resistant pathogen primarily associated with cystic fibrosis. Bloodstream infections (BSIs) are rare but linked to high mortality. The genomic characteristics and evolutionary history of P. sputorum lineages causing BSIs remain poorly understood.Methods. We performed whole-genome sequencing on 18 P. sputorum isolates recovered from patients with BSIs in China between June 2022 and March 2024. Phylogenetic relationships were determined by core-genome SNP analysis, and the pan-genome was characterized using Roary. Antimicrobial resistance and virulence genes were identified using the CARD and VFDB databases. Evolutionary timescales were estimated using Bayesian molecular clock analysis.Results. The case fatality rate among patients was 27.8% (5 out of 18). Common clinical manifestations included fever (83.3%, 15 out of 18), productive cough (77.8%, 14 out of 18) and dyspnoea (61.1%, 11 out of 18). All isolates formed a distinct monophyletic lineage, genetically distant (>2,000 SNPs) from known P. sputorum strains but with minimal intra-lineage diversity (15-98 SNPs), indicating recent clonal expansion. The pan-genome was highly conserved, with core genes comprising 94.6% of the gene repertoire. All strains harboured core genome-encoded ceoB (efflux pump) and OXA-155 (β-lactamase) genes, conferring resistance to multiple antimicrobials but remaining susceptible to imipenem. Bayesian analysis estimated the origin of this lineage in 2004 (95% highest posterior density: 2003.2-2005.8), with major diversification occurring between 2007 and 2018.Conclusion. We identified a novel, recently emerged and highly clonal lineage of P. sputorum associated with high-mortality BSIs. Its stable reservoir of core genome-encoded resistance mechanisms poses a significant therapeutic challenge. This lineage represents an emerging multidrug-resistant threat to public health, necessitating enhanced surveillance and infection control measures.

Sepsis accounts for nearly 20% of global mortality, with antibiotic resistance worsening clinical outcomes. Rapid antibiotic administration and accurate pathogen identification remain crucial. It is well now known that extracellular vesicles (EVs) from human cells and bacterial membrane vesicles (bMVs) play a central role in the interaction between host and pathogen and represent promising biomarkers for early infections. This study investigated how antibiotic exposure alters EV responses in Staphylococcus aureus (SA)spiked blood and compared these findings with EV proteome profiles from bacteremia patients. In an in vitro model, whole blood from healthy donors was spiked with SA at a multiplicity of infection (MOI) of 0.001, treated with clinically relevant concentrations of piperacillin-tazobactam, vancomycin, or moxifloxacin, and plasma was subsequently isolated for EV analysis. EVs were isolated using the Miltenyi Pan EV Kit and analyzed by bead-based flow cytometry and high-resolution LC-MS/MS. In parallel, serum EVs from healthy controls (n = 6) and bacteremia patients (n = 12; 6 blood culture-positive and 6 culture-negative) were analyzed using the same workflow. Flow cytometry revealed increased levels of CMO[+] CD45[+] PanEV[+] SA[+] vesicles in SA-spiked samples, particularly following low-dose piperacillin-tazobactam and high-dose vancomycin treatment, despite minimal changes in vesicle size and total particle counts. Proteomic analysis of plasma EVs showed significant alterations in protein composition, including increased abundance of the SA-derived ribosomal protein rplU and host defense-associated proteins. Functional enrichment highlighted pathways related to neutrophil degranulation, vesicle-mediated transport, and antibacterial responses. In patient samples, serum EVs were enriched in acute-phase and immune-related proteins, including SERPINA1, SERPINA3, CRP, and SAA2, along with canonical EV markers such as CD81 and syntenin-1, irrespective of blood culture status. Antibiotic exposure and SA infection are associated with measurable changes in the human EV proteome, characterized by enrichment of immune and host defense-related proteins despite stable vesicle numbers. Similar EV-associated protein patterns were observed in both blood culture-positive and -negative patient samples, reflecting shared features of the systemic host response to infection and highlighting the potential of EV profiling to capture infection-associated biological signals.

Streptococcus canis (S. canis) is an underrecognized zoonotic pathogen capable of causing invasive human infection. We report a case of sepsis with acute hypoxic respiratory failure due to S. canis bacteremia in a 73-year-old woman with multiple comorbidities, including breast cancer complicated by chronic lymphedema and cardiovascular disease. She presented with fever, progressive dyspnea, hypoxemia, leukocytosis, acute kidney injury, and rising cardiac troponin levels. Imaging demonstrated bilateral interstitial opacities consistent with pulmonary edema, and her clinical course required intensive care management. Two sets of blood cultures grew S. canis, a group G β-hemolytic streptococcus most commonly associated with dogs and cats. Species-level identification was achieved using polymerase chain reaction-based blood culture testing followed by automated biochemical confirmation. The patient was initially treated with broad-spectrum antibiotics and subsequently transitioned to intravenous penicillin G after susceptibility testing demonstrated β-lactam sensitivity. Further history revealed frequent exposure to a household dog without history of bites or scratches, supporting probable non-traumatic zoonotic transmission. The patient improved with targeted therapy and completed a 13-day course of intravenous antibiotics. This case demonstrates that S. canis can cause severe cardiopulmonary compromise in elderly patients and highlights the epidemiologic value of species-level identification in recognizing zoonotic transmission and prompting targeted assessment of animal exposure in patients with group G streptococcal sepsis.

Capnocytophaga canimorsus is a gram-negative, anaerobic bacillus commonly found in the oral flora of dogs and cats. While often transmitted through animal bites or scratches, severe infections can occur even without documented exposure, particularly in immunocompromised individuals such as asplenic patients. Although rare, mycotic aneurysms caused by C. canimorsus are associated with high mortality. We report the case of a 53-year-old male with a history of splenectomy due to diffuse large B-cell lymphoma, currently in remission, who presented with malaise, fever, dyspnea, and abdominal pain. He rapidly progressed to septic shock and multiorgan failure, including coagulopathy consistent with disseminated intravascular coagulation (DIC). Despite broad-spectrum antibiotics and intensive support, the patient died within hours of admission. Blood cultures later confirmed C. canimorsus bacteremia. Postmortem examination revealed a ruptured aortic aneurysm. This case highlights the fulminant progression of C. canimorsus infection in an asplenic patient, culminating in a fatal aortic aneurysm rupture. Notably, there was no history of animal exposure, reinforcing the need for high clinical suspicion, especially in high-risk populations. Although empiric therapy with beta-lactam/beta-lactamase inhibitors is recommended, early recognition and possible surgical intervention remain crucial for survival. Infections caused by C. canimorsus should be considered in septic patients with risk factors such as splenectomy, even in the absence of animal contact. Rapid deterioration and rare complications, like aortic aneurysm rupture, underscore the importance of early diagnosis and aggressive multidisciplinary management.

Chromobacterium violaceum is a rare but highly virulent Gram-negative organism found in tropical and subtropical environments, associated with rapidly progressive sepsis and high mortality. Musculoskeletal involvement, particularly septic arthritis, is exceedingly uncommon. We report a case of a previously healthy 23-year-old male who presented with progressive left ankle pain, swelling, and fever. Initial evaluation revealed thrombocytopenia, markedly elevated inflammatory markers, and positive serology for Dengue virus infection, suggestive of a possible concurrent infection. Blood cultures grew C. violaceum, confirming bacteremia. Despite initiation of intravenous antibiotics and supportive care, the patient experienced rapid clinical deterioration with septic shock, severe metabolic acidosis, hyperkalemia, and multi-organ failure. He required intubation and vasopressor support but suffered multiple cardiac arrests and died within three days of hospitalization. This case highlights the aggressive clinical course of C. violaceum infection, even in immunocompetent individuals, and underscores the diagnostic and therapeutic challenges associated with this rare pathogen. Concurrent dengue infection may have contributed to immune dysregulation and worsened disease severity. Early recognition, prompt diagnosis, and appropriate antimicrobial therapy are critical in managing C. violaceum infections. Clinicians should maintain a high index of suspicion in patients presenting with rapidly progressive sepsis, especially in endemic regions or in the presence of potential environmental exposure.

BACKGROUND Capnocytophaga canimorsus is a gram-negative bacillus found in the oral cavity of dogs and cats. Human infection is uncommon but can cause severe sepsis. Although classically associated with asplenia, alcohol use disorder, or immunosuppression, a substantial proportion of cases occur in patients without identifiable risk factors. Diagnosis may be delayed due to the fastidious nature of the organism and the impact of prior antibiotic exposure on culture yield. CASE REPORT A 75-year-old woman presented with fever and right upper-quadrant abdominal pain 6 weeks after right total hip arthroplasty. She had no history of animal bite but reported close contact with dogs. Initial investigations did not identify a source of infection, and empirical ceftriaxone was initiated. Blood cultures became positive after extended incubation (Day 10), with identification of C. canimorsus by MALDI-TOF mass spectrometry. Imaging studies were inconclusive for prosthetic joint infection. The patient was treated with high-dose amoxicillin for 14 days, with favorable clinical and biological outcomes. CONCLUSIONS C. canimorsus infection should be considered in patients presenting with sepsis or persistent fever and a history of dog or cat exposure, even in the absence of a bite. Close collaboration with microbiology laboratories may be required to ensure appropriate culture conditions. Clinicians should also be aware of the potential for diagnostic uncertainty in patients with recent prosthetic implants.

Vibrio vulnificus is a rapidly progressive, life-threatening pathogen endemic to coastal environments, yet clinical data from Southeast Asia remain limited despite substantial environmental contamination. We conducted a 6.5-year multicenter retrospective cohort study at two tertiary-care hospitals in Eastern Thailand to describe clinical characteristics, antimicrobial susceptibility, treatment practices, and factors associated with early mortality among adults with culture-confirmed V. vulnificus infection. Forty-nine patients were identified, most of whom presented with severe illness; 83.7% had bacteremia, 61.2% required mechanical ventilation, and 75.5% required vasopressor support. Skin and soft tissue infection was the most common syndrome, with necrotizing soft-tissue infection accounting for approximately two-thirds of cases. Antimicrobial susceptibility was uniformly high for fluoroquinolones, carbapenems, and third-generation cephalosporins, although susceptibility to doxycycline was unavailable. Despite high rates of empirical antimicrobial therapy (91.8%), mortality remained substantially high: 42.9% died within 48 hours, and 7-day mortality reached 49.0%. In multivariable analysis, elevated serum lactate and lack of surgical treatment were associated with early mortality, while chronic alcohol use and vasopressor requirement showed nonsignificant trends toward increased mortality. These findings highlight the fulminant nature of V. vulnificus infection and the narrow therapeutic window for effective intervention. In settings where necrotizing soft-tissue infection is common and patients present with advanced disease, early recognition, aggressive resuscitation, timely surgical management, and prompt initiation of antimicrobial therapy remain essential. This study provides region-specific epidemiologic and clinical insights that may inform clinical management and public health strategies in coastal communities at risk.

Blood cultures remain the cornerstone of diagnosing bloodstream infections, and their appropriate use directly impacts timely diagnosis, targeted antimicrobial therapy, and patient safety. However, their diagnostic yield and clinical interpretability are determined not only by laboratory processing itself, but also by the entire sequence of interconnected pre-analytical, analytical, and post-analytical steps. This review article summarizes the principles of blood culture testing, focusing on appropriate indications and timing of blood collection, recommended number of culture sets and blood volume, aseptic collection techniques, specimen labeling, transport, and laboratory receipt. It also addresses the analytical phase, including the selection of culture systems and media, the role of additives, incubation conditions, monitoring for positivity, and subsequent processing of positive blood cultures. Separate attention is devoted to the post-analytical phase, particularly result interpretation, reporting critical findings, blood culture contamination, surveillance of catheter-associated infections, and isolate storage. The final section focuses on quality indicators and the importance of systematic quality management throughout the entire process. The article emphasizes that blood cultures should be regarded as a complex diagnostic process, whose quality depends on the coordination of clinical and laboratory procedures, workflow standardization, and ongoing evaluation of measurable performance indicators. Keywords: blood cultures, bacteremia, fungemia, pre-analytical phase, analytical phase, post-analytical phase, blood culture contamination, quality management.

Human preterm premature rupture of membranes (PPROM) refers to the spontaneous rupture of fetal membranes before 37 weeks of gestation and prior to labor. Clinically, the decision to induce labor or continue expectant management must be balanced against the risk of infection, particularly chorioamnionitis. Early diagnosis is critical, as chorioamnionitis is associated with preterm birth and fetal (hypoxia and/or sepsis) and maternal (bacteremia, hemorrhage, and/or death) complications. Currently, no specific blood biomarker is routinely used, with only nonspecific parameters like C-reactive protein (CRP) and white blood cell (WBC) count available. This highlights the need to review and meta-analyze recent studies to summarize new maternal blood biomarkers and improve diagnostic performance. A meta-analysis was performed to assess the prognostic value of some current or new blood biomarkers in predicting histological or clinical chorioamnionitis in women after PPROM. A protocol was designed and registered with PROSPERO (CRD420251058686). Studies were chosen if they included women with PPROM who underwent blood biomarker measurements and histological evaluation of the fetal membranes or clinical assessment of chorioamnionitis. The quality of each study was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) criteria. Three databases (Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL)) were consulted. Of the 631 articles screened, 9 were finally selected for inclusion. The overall pooled sensitivity (Se) of CRP, WBC count, procalcitonin (PCT), and neutrophil-lymphocyte ratio (NLR) were respectively 71% (95% CIs of 60%-81%), 73% (95% CIs of 66%-79%), 83% (95% CIs of 68%-94%) and 75% (95% CIs of 68%-81%). The overall pooled specificity (Spe) of CRP, WBC, PCT, and NLR were respectively 75% (95% CIs of 73%-78%), 61% (95% CIs of 52%-63%), 41% (95% CIs of 10%-76%) and 82% (95% CIs of 61%-96). The area under the curve (AUC), obtained from receiver operating characteristic (ROC) curve analysis was 77%, 73%, 74%, and 77% for CRP, WBC count, PCT, and NLR, respectively. Evidently, no single biomarker currently appears capable of accurately predicting the occurrence of chorioamnionitis, as the diagnostic performance of tested biomarkers remains modest. Over the past five years, no new biomarker has been evaluated frequently enough to allow for a meta-analysis of its diagnostic accuracy. This emphasizes the importance of identifying new predictive biomarkers, particularly through large-scale proteomic approaches.