Abdominal actinomycosis by Actinomyces shaaliae georgiae mimicking neoplasia

P47 Presentation, management, and outcomes of pyogenic liver abscess in a single UK centre: a comparison between centres and an evaluation of liver abscess management

Introduction. Rapid identification (ID) and antimicrobial susceptibility testing (AST) of bloodstream infections (BSI) pathogens are fundamental to switch from empirical to targeted antibiotic therapy improving patients outcome and reducing antimicrobial resistance spreading.Hypothesis. The adoption of a rapid microbiological protocol (RP) based on Matrix-Assisted Laser Desorption Ionization-Time Of Flight Mass Spectrometry (MALDI-TOF MS) and Light Scattering Technology (LST) for rapid diagnosis of BSI could positively impact on patients' antimicrobial management.Aim. The study aim was to evaluate a RP for BSI microbiological diagnosis in terms of accuracy, turnaround time (TAT) and potential therapeutic impact.Methodology. A prospective observational study was conducted: monomicrobial bacterial blood cultures of septic patients were analysed in parallel by RP and standard protocol (SP). In RP the combination of MALDI-TOF MS and LST was used for rapid ID and AST assessments, respectively. To determine the potential impact of RP on antimicrobial therapy management, clinicians were interviewed on therapeutic decisions based on RP and SP results. RP accuracy, TAT and impact were evaluated in comparison to SP results.Results. A total of 97 patients were enrolled. ID and AST concordance between RP and SP were 96.9 and 94.7 %, respectively. RP technical and real-life TAT were lower than SP (6.4 h vs. 18.4 h; 9.5 vs. 27.1 h). The agreement between RP- and SP-based therapeutic decisions was 90.7 (90 % CI 84.4-95.1). RP results could produce 24/97 correct antibiotic changes with 18/97 possible de-escalations and 25/97 prompt applications of infection control precautions.Conclusion. With the application of RP in BSI management, about one-fourth of patients may safely benefit from early targeted antibiotic therapy and infection control policies with one working day in advance in comparison to conventional methods. This protocol is feasible for clinical use in microbiology laboratories and potentially helpful for Antimicrobial Stewardship.

Actinomycosis is a chronic suppurative infection, for which immune suppression is a predisposing factor. In unusual cases, this disease may present as an abdominal wall involvement simulating a soft tissue tumor as seen in the present case. The presented patient had no signs of trauma or surgical approach and the pathology was considered to be a primary abdominal wall actinomycosis. Preoperative diagnosis is difficult due to the nonspecific nature of clinical presentation, radiographic and laboratory findings. Surgery combined with antibiotic treatment is a curative approach for this relatively rare infection. Surgeons must be aware of this disease in order to ensure correct diagnosis and to prevent performing any unnecessary procedures. The present study describes a case of abdominal actinomycosis with multiple myeloma, together with a review of important points related to this disease.

Simple SummaryObstructive jaundice caused by pancreatic cancer remains a common and challenging clinical condition. Traditionally, biliary drainage has been performed using endoscopic retrograde cholangiopancreatography or percutaneous transhepatic biliary drainage. However, these conventional approaches are not always feasible and may be associated with significant complications. Endoscopic ultrasound-guided biliary drainage (EUS-BD) has emerged not only as a reliable rescue technique when standard methods fail but also as a promising first-line option in selected cases. This review summarizes the main EUS-BD techniques and their current role compared with conventional strategies. It also highlights recent technological innovations likely to further strengthen the role of EUS-BD in clinical practice. Additionally, common clinical scenarios in which EUS-BD can be applied are outlined, along with a practical algorithm for the management of malignant biliary obstruction. Overall, this review aims to help clinicians better understand how these techniques can improve patient outcomes and contribute to more effective multidisciplinary care.The indications for biliary drainage in cases of pancreatic head tumors with biliary obstruction are well established. ERCP with stent placement has long been the gold standard technique, outperforming surgery or percutaneous drainage. However, in cases of distal malignant biliary obstruction, ERCP becomes more complex, increasing the risk of complications. The advent of therapeutic endoscopic ultrasound (EUS), particularly EUS–choledochoduodenostomy (EUS-CDS) and EUS–hepaticogastrostomy (EUS-HGS), has transformed the management of distal malignant biliary obstruction in the case of pancreatic cancer. EUS-CDS creates communication between the duodenum and the common bile duct. Lumen-apposing metal stents (LAMSs) simplify the procedure, offering high technical and clinical success rates and making the technique easier to perform. Nevertheless, long-term dysfunction rates remain high, necessitating careful definition of procedural indications. EUS-HGS, a more complex technique, connects dilated left bile ducts to the stomach and requires advanced expertise; it is associated with a higher rate of complications. However, its clinical efficacy and technical success are comparable to those of EUS-CDS, and it is the preferred technique in cases of duodenal obstruction or altered anatomy. European and American guidelines currently position EUS-guided biliary drainage (EUS-BD) as a second-line approach after ERCP failure or when ERCP is not feasible, but there is a growing trend toward earlier use. Other techniques are emerging, such as EUS-guided gallbladder drainage (EUS-GBD) and combining EUS-HGS with antegrade stenting, offering valuable alternatives when conventional techniques fail or are inaccessible.

Natural History of Pediatric Crohn Disease T he natural history of pediatric Crohn disease (CD) remains unpredictable, although some trends are observed that differentiate children from adults. Pediatric CD often presents with more severe disease and more frequent need for immunosuppressive therapy (1). Growth failure, present in 15% to 20% of patients, is a unique characteristic of pediatric CD not seen in adult-onset CD (2). Colonic disease distribution is common in patients younger than 10 years (1). The need for surgical intervention also varies, with 1 study reporting the actuarial risk of having undergone an extensive intestinal resection being 48.6% 5% in a childhood-onset group versus 14.6% 2% in the adult-onset group (P< 0.001) (1). More recently, long-term follow-up of patients enrolled in pediatric registries shows a cumulative surgical rate of 14% to 17% at 5 years and 28% at 10 years (3,4).

Abdominal actinomycosis, a rare and often misdiagnosed condition caused by Actinomyces israelii, typically a commensal organism in the oral cavity and gastrointestinal tract, can become pathogenic, leading to chronic granulomatous infections that mimic various abdominal pathologies, including malignancies. We present a case of a 59-year-old male with coronary artery disease and type 2 diabetes who presented with severe abdominal pain, initially diagnosed as acute appendicitis. During exploratory laparotomy, an ileocecal band mimicking a congenital anomaly was discovered. Histopathological examination confirmed abdominal actinomycosis, revealing clusters of Actinomyces bacteria surrounded by acute inflammatory cells. The patient was successfully treated with surgical intervention and prolonged penicillin therapy, with no recurrence during a four-month follow-up. This case highlights the diagnostic challenges posed by abdominal actinomycosis and emphasizes the importance of considering it in the differential diagnosis of abdominal masses and appendicitis-like symptoms.

ABSTRACT16S rRNA gene sequencing is increasingly used in clinical practice for bacterial identification of clinical specimens. However, studies on its applicability to direct clinical specimens are limited. Here, we studied the diagnostic yield and impact of 16S rRNA gene sequencing from direct clinical specimens on antimicrobial management. Adult inpatients whose attending physician requested 16S rRNA gene sequencing and corresponding bacterial culture from a direct clinical specimen between January and December 2021 in a university hospital were prospectively included in this study. A total of 434 specimens from 374 patients were requested. Of these, 253 (58.3%) specimens were collected from patients whose final diagnosis indicated a bacterial infection, whereas 181 (41.7%) specimens were from nonbacterial infections. Using the final diagnosis as a “gold standard,” the sensitivity and specificity of 16S rRNA gene sequencing were 38.3% and 93.9%, respectively. Among the bacterial infection cases, the proportion of 16S rRNA gene sequencing-positive and culture-positive cases was 32.4%, and the proportion of sequencing-positive and culture-negative cases was 5.9%. The impact on antimicrobial management was evident in 10 (2.3%) specimens, which all resulted in the continuation of antibiotics. The impact on antimicrobial management was highest in skin and soft tissue infections, followed by bone and joint infections. In this study, the long turnaround time of 16S rRNA gene sequencing of clinical specimens was a limiting factor. In conclusion, the overall diagnostic yield of 16S rRNA gene sequencing in bacterial infection cases was fair, being useful in selected cases. Restrictions on test requests may improve test utilization in this setting.IMPORTANCE 16S rRNA gene sequencing has been increasingly used in clinical practice. Using the final diagnosis as a gold standard, the sensitivity of 16S rRNA gene sequencing was fair. In the setting with no 16S rRNA gene sequencing test ordering restrictions, only small percentages of the test results had an impact on antimicrobial management. Restrictions on test requests should be developed to maximize the benefit of the test.

Abdominal actinomycosis (AA) is a rare infection caused by filamentous Gram-positive anaerobic bacteria Actinomyces. We report two cases of adults with AA who initially presented with clinical and radiological features of appendicitis. Both patients underwent appendicectomy with histopathology diagnostic for actinomycosis of the appendix and subsequently completed prolonged courses of oral penicillin. AA is a rare differential diagnosis for appendicitis and should be considered especially in patients with a chronic, indolent course and nonspecific abdominal symptoms. A high index of suspicion may avoid unnecessary surgery, as treatment with prolonged antibiotic therapy is very effective.

Diffuse Fibrosis of the Colon Complicating Cystic Fibrosis

Case report: Percutaneous drainage of periappendiceal actinomycosis

Background16s rRNA gene sequencing has an advantage over traditional bacterial culture in situations where bacteria are difficult to culture, unculturable, or have previously been exposed to antimicrobial. The study on its applicability to direct clinical specimens is still limited. We studied the value of 16s rRNA gene sequencing from direct clinical specimens on antimicrobial management.MethodsInpatient adults whose attending physician requested 16s rRNA gene sequencing and corresponding bacterial culture from a direct clinical specimen were prospectively included between January and December 2021. Diagnostic yield and the impact of 16s rRNA gene sequencing on antimicrobial management were investigated.ResultsA total of 434 specimens from 374 patients were requested. All patients had a complete follow-up and had a definitive final diagnosis. The sensitivity and specificity of 16s rRNA gene sequencing were 38.3% and 93.9%, respectively. The agreement between 16s rRNA gene sequencing and conventional culture among specimens obtained from bacterial infection cases was 83.8% (the κ coefficient 0.664, p< 0.001). Among bacterial infection cases, the proportion of 16s rRNA gene sequencing positive/culture-positive was 32.4% (82 specimens), and the proportion of sequencing positive/culture-negative was 5.9% (15 specimens). The impact on antimicrobial management occurred in 10 (2.3%) specimens, which all resulted in the continuation of antibiotics. An impact on antimicrobial management was highest in the skin and soft tissue infection, followed by bone and joint infection. In contrast, CAP/HAP/VAP was less likely to benefit from this test. Long turnaround time was the limitation of the test in this study, the median (interquartile range) was 11 (9-13) days in the 16s rRNA gene sequencing positive group, and 2 (1-4) days in the 16s rRNA gene sequencing negative group.ConclusionThe overall diagnostic yield of 16s rRNA gene sequencing in bacterial infection cases was fair. 16s rRNA gene sequencing was useful in selected cases, but it cannot replace traditional culture. The negative result did not exclude bacterial infection. Restrictions on test requests may improve test utilization in this setting.DisclosuresAll Authors: No reported disclosures.

PurposeThe objective of this study was to compare the diagnostic performance of positron emission tomography (PET), PET/CT, CT and MRI as whole-body imaging modalities for the detection of local and/or distant recurrent disease in colorectal cancer (CRC) patients who have a (high) suspicion of recurrent disease, based on clinical findings or rise in carcinoembryonic antigen (CEA).MethodsA meta-analysis was undertaken. PubMed and Embase were searched for studies on the accuracy of whole-body imaging for patients with suspected local and/or distant recurrence of their CRC. Additionally, studies had to have included at least 20 patients with CRC and 2 × 2 contingency tables had to be provided or derivable. Articles evaluating only local recurrence or liver metastasis were excluded. Summary receiver-operating characteristic (ROC) curves were constructed from the data on sensitivity and specificity of individual studies and pooled estimates of diagnostic odds ratios (DORs) and areas under the ROC curve (AUCs) were calculated. To test for heterogeneity the Cochran Q test was used.ResultsFourteen observational studies were included which evaluated PET, PET/CT, CT and/or MRI. Study results were available in 12 studies for PET, in 5 studies for CT, in 5 studies for PET/CT and in 1 study for MRI. AUCs for PET, PET/CT and CT were 0.94 (0.90–0.97), 0.94 (0.87–0.98) and 0.83 (0.72–0.90), respectively. In patient based analyses PET/CT had a higher diagnostic performance than PET with an AUC of 0.95 (0.89–0.97) for PET/CT vs 0.92 (0.86–0.96) for PET.ConclusionBoth whole-body PET and PET/CT are very accurate for the detection of local and/or distant recurrent disease in CRC patients with a (high) suspicion of recurrent disease. CT has the lowest diagnostic performance. This difference is probably mainly due to the lower accuracy of CT for detection of extrahepatic metastases (including local recurrence). For clinical practice PET/CT might be the modality of choice when evaluating patients with a (high) suspicion of recurrent disease, because of its best performance in patient based analyses and confident prediction of disease status.

Introduction Abdominal pain is commonly encountered in the pediatric population and prompts medical evaluation in both clinic and emergency department settings. In a 2007 study by Leoning-Baucke, et al., as many as 9% of pediatric patients 4 to 18 years of age required medical assessment for acute onset abdominal pain. In this case, abdominal actinomycosis, a rare etiology of abdominal pain in an adolescent female, is explored. Case Description A 14 year old AAF with no significant medical history developed acute onset right upper quadrant abdominal pain with associated …

Aim Prosthetic joint infection (PJI) is a serious complication following total joint arthroplasty (TJA) and can have devastating consequences if not treated effectively. There is no clear ‘gold standard’ for the diagnosis of PJI, current techniques include blood biochemical markers and microbiological cultures to identify the species of bacteria. Challenges associated with microbiological cultures include inaccurate results and time delays before reporting of results. In the hospital of study, samples of joint fluid and tissue are collected during surgical intervention for PJI and are sent to a partner hospital for microbiological cultures. Results are typically reported back after 7-14 days. Nanopore sequencing is a third-generation genomic sequencing technology designed to facilitate fast, inexpensive, and simple genomic sequencing. This study aims to investigate nanopore sequencing, as a quick and cost-effective method to identify the species of bacteria causing PJI from joint aspirates. Method Joint fluid aspirates were collected during surgical interventions for PJI. DNA was extracted from these samples and sequenced using the MinION device. Sequencing data was classified using Basic Local Alignment Search Tool (BLAST) against the bacterial database. Sequencing data was filtered by quality parameters such as Phred score. 30 samples of fluid were used for nanopore sequencing (26 PJI-positive and 4 controls), based on clinical definitions of infection. Clinical assessments included blood biochemical markers (CRP, ESR), histology, physical signs (e.g., redness, swelling) and multi-disciplinary team (MDT) decision. The MDT decision was used as the clinical decision of infection. Results from nanopore sequencing and microbiological cultures were compared with clinical assessments. Results Contingency tables were made to compare nanopore sequencing with the clinical assessment of patients and to compare microbiological cultures with the clinical decision of patients. Combining the results from nanopore sequencing with microbiological cultures gave an accuracy of 0.89, positive predictive value (PPV) of 0.92, recall (sensitivity) of 0.96 and F1 score of 0.94. The accuracy for microbiological cultures alone was 0.62. Conclusions Nanopore sequencing shows promise as an additional test in diagnosing PJI, particularly when cultures are negative. The advantage for the use of nanopore sequencing in the diagnosis of PJI is the turn-around time of results compared to microbiological cultures. This could have implications with reducing hospital stays, length of treatment and time frames between the first and second stage of a two-stage prosthetic exchange. This may improve patient outcomes and reduced treatment costs. Further studies could solidify its role in routine PJI diagnosis.

A Rare Skin Disorder with Bacteremia in a Neonate.