Milleri Group Research Articles

Streptococcus constellatus appendicitis in children: A case series

AbstractBackgroundStreptococcus constellatus (SC) is a pathogen well‐known for its involvement in pyogenic infections, with a notable preference for manifesting within the oral cavity, head and neck, and abdomen. This bacterium, belonging to the Streptococcus milleri group, has garnered attention for its propensity to incite inflammatory processes, especially in the abdominal region.ObjectivesThis study aims to present and characterise nine cases of paediatric patients with SC appendicitis.MethodsWe conducted a report on nine cases of SC appendicitis, all of whom presented to the emergency room with typical symptoms of appendicitis.ResultsPatients diagnosed with SC appendicitis exhibited a severe clinical course, necessitating appendectomy at presentation and requiring prolonged parenteral antimicrobial therapy. Furthermore, a higher readmission rate was observed among these patients, even several months after their initial discharge.ConclusionsSurgeons should be vigilant regarding SC appendicitis and its severe clinical course. Prolonged treatment with antimicrobial agents may be necessary for these patients to achieve better outcomes.

Effect of Lactiplantibacillus plantarum cell-free culture on bacterial pathogens isolated from cystic fibrosis patients: in vitro and in vivo studies.

This study aimed to investigate the effects of the cell-free supernatant of Lactiplantibacillus plantarum ATCC® 10241TM on the biofilm-forming capacity of Pseudomonas aeruginosa strains isolated from cystic fibrosis (CF) patients. In addition, the study evaluated the in vivo potential of the cell-free supernatant to modulate inflammation and reduce lung damage in mice infected with P. aeruginosa strains or co-challenged with P. aeruginosa and the Streptococcus milleri group (SMG). The results showed that CF-derived P. aeruginosa strains can infect the respiratory tract of adult mice, inducing local inflammation and lung damage. The severity of these infections was exacerbated when P. aeruginosa was co-administered with SMG. Notably, nebulization with the cell-free supernatant of L. plantarum produced beneficial effects, reducing respiratory infection severity and inflammatory responses induced by P. aeruginosa, both alone or in combination with SMG. Reduced bacterial loads and lung damage were observed in supernatant-treated mice compared to controls. Although further mechanistic studies are necessary, the results show that the cell-free supernatant of L. plantarum ATCC® 10241TM is an interesting adjuvant alternative to treat P. aeruginosa respiratory infections and superinfections in CF patients.

EP568 - A rare case of necrotizing fasciitis caused by Streptococcus Anginosus and Staphylococcus Lugdunensis

Abstract Necrotizing fasciitis (NF) is a rare soft tissue infection involving the fascial planes, causing rapid and extensive tissue destruction. We present a unique case of NF in a patient with poor glycemic control caused by atypical pathogens. A 66-year-old female with a recent biopsy for a wart-like lesion developed a wound infection, with greenish-black exudate. Initial observations were: temperature: 39.4 degrees, heart rate: 105, GCS: 15/15. Physical examination revealed a grossly filiform lesion below her abdominal apron measuring 7cm in diameter. The patient was empirically treated with IV Co-Amoxiclav. Abnormal biochemistry results are shown below. Microbiological analysis revealed Streptococcus Anginosus, anaerobes and Staphylococcus Lugdunensis. CT abdomen revealed extensive inflammatory changes with gas and fluid collection and enlarged pelvic and inguinal lymph nodes. Two urgent surgical explorations and debridements, with meticulous wound care using negative pressure wound dressings (Prevena) were done. Intravenous Gentamicin, Benzylpenicillin, Clindamycin, Metronidazole and Flucloxacillin were administered for six weeks. The patient's clinical status gradually improved. Streptococcus Anginosus, that is part of the Streptococcus Milleri group and Staphylococcus Lugdunensis, a coagulase-negative Staphylococci (CoNS) are commensal organisms of the oral and gastrointestinal tracts. These organisms possess virulence factors that facilitate tissue invasion and destruction, causing an aggressive course of NF. This case highlights the importance of considering atypical pathogens, especially in patients with predisposing factors such as diabetes and obesity. Early recognition, prompt surgical intervention and a multidisciplinary approach are essential for improving outcomes in these cases.TestResultWhite Blood Cells (WBC)22,200 [WBCs per microliter]Sodium123 [mmol/L]Chloride88 [mmol/L]C-reactive protein (CRP)318 [mg/L]Blood Glucose19.3 [mmol/L]

Biomarker of neutrophil extracellular traps is associated with deep-seated infections and predicts mortality and cardiovascular morbidity in commensal streptococcal bacteremia.

Neutrophil extracellular traps (NETs) play important roles in sepsis and deep-seated infections, but whether NET formation correlates with clinical outcomes of patients with streptococcal bloodstream infections (BSIs) is unclear. We analyzed serum levels of complexes of myeloperoxidase and DNA (MPO-DNA) in patients with streptococcal-BSIs. Invitro assay of NET induction by serum from BSI patients was performed. MPO-DNA values for the Streptococci-BSI group (n=59) were significantly higher than those for healthy controls (p<0.00001) and matched control groups (n=59, p=0.004). The rate of higher MPO-DNA levels (>1.87μg/mL) were higher in abscess-prone streptococcal groups (streptococcus milleri group) (72.2% vs. 52.5%, p=0.02). For patients with BSIs due to highly infective endocarditis (IE)-prone pathogens, the values of serum MPO-DNA were also higher in patients diagnosed of IE compared to their counterparts (p=0.009). Notably, serum from patients with leukopenia could induce higher amounts of invitro NET formation, despite having low MPO-DNA levels, suggesting that NET formation could be influenced by WBC counts. Therefore, we combined WBC counts with MPO-DNA to predict all-cause 30-day mortality in patients with commensal streptococcal-BSIs. The mortality risk was lowest among patients who had neither high MPO-DNA levels nor abnormal WBC counts (p=0.058). Furthermore, this group of patients also had a favorable composite outcome consisting of major adverse cardiovascular events (MACE) and all-cause mortality (p=0.026). Together, these study data suggested that serum MPO-DNA can be a biomarker for predicting a composite outcome consisting of MACE and all-cause mortality in patients with commensal streptococcal-BSIs.

Septic shock from multiple intra-abdominal Streptococcus constellatus abscesses unamenable to percutaneous drainage

ABSTRACTStreptococcus constellatus are gram-positive cocci belonging to the Streptococcus milleri group that have a propensity to cause bacteremia and abscesses, especially in immunocompromised patients. Here, we report the case of a 39-year-old male who was initially admitted to the hospital for diabetic ketoacidosis. During the hospitalization, he developed sepsis and blood cultures grew Streptococcus constellatus. CT imaging revealed multiple hepatic abscesses. A periapical abscess of the left mandibular central incisor found on CT Scan of face was identified as the likely source of infection. IR-guided drainage was performed however the patient went on to develop septic shock despite attempted source control and IV antibiotic therapy. Repeat imaging showed persistent hepatic abscesses in addition to new intraperitoneal abscesses necessitating exploratory laparotomy, drainage and abdominal washout. Fluid cultures grew Streptococcus constellatus and common enteric flora. Our report highlights the need for high clinical suspicion in cases of Streptococcus constellatus bacteremia to obtain diagnostic imaging for any abscess formation. Prolonged antibiotic therapy is a must and imaging guided or surgical drainage may be needed.

The Clinical View on Streptococcus anginosus Group – Opportunistic Pathogens Coming Out of Hiding

Three distinct streptococcal species: Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus, belonging to the Streptococcus anginosus group (SAG), also known as Streptococcus milleri group, have been attracting clinicians and microbiologists, not only as oral commensals but also as opportunistic pathogens. For years they have been simply classified as so called viridans streptococci, and distinct species were not associated with particular clinical manifestations. Therefore, description of SAG members are clearly underrepresented in the literature, compared to other medically relevant streptococci. However, the increasing number of reports of life-threatening infections caused by SAG indicates their emerging pathogenicity. The improved clinical data generated with the application of modern molecular diagnostic techniques allow for precise identification of individual species belonging to SAG. This review summarizes clinical reports on SAG infections and systematizes data on the occurrence of individual species at the site of infection. We also discuss the issue of proper microbiological diagnostics, which is crucial for further clinical treatment.

A surgical protocol for sinogenic brain abscess: the Oxford experience and a review of the literature.

Rhinosinusitis-induced brain abscesses are rare but can result in devastating long-term sequalae and mortality; they require a high index of suspicion with early imaging to start early empiric parenteral antibiotic treatment covering aerobes and anaerobes. Our study was a retrospective analysis on 32 patients who were treated at Oxford University Hospitals for rhinosinusitis-induced brain abscess between February 2013 and June 2020. Mean age of presentation was 45.83 for adults and 11.14 for children. Subdural collection was the most frequent abscess but 25% of patients had multiple sites of collection; the majority were in the frontal lobe. The most commonly identified pathogens were Streptococcus milleri group and Staphylococcus aureus; 93.75% of the patients were treated with combined Ceftriaxone and Metronidazole for an average of 8 weeks. In our series most patients received also a prompt and aggressive surgical treatment with combined neurosurgical and ENT procedures in the majority; this was especially important in case of subdural empyema, Streptococcus milleri infection and direct intracranial spread of infection. More than half of the patients were treated with a single surgical procedure. Despite aggressive treatment, one third of patients experienced long-term neurological sequelae; there were no deaths.

Hyperbaric Oxygen as Adjunctive Therapeutic in Management of Craniocervical Necrotizing Fasciitis: Case Series and Treatment Protocol

BackgroundOdontogenic infections are commonly encountered in OMS practices. Rarely, odontogenic infections can progress into craniocervical necrotizing fasciitis (CCNF). CCNF of the head and neck is a rare, potentially lethal disease process involving infection and subsequent destruction of fascial planes. Mortality ranges from 33% to 50% if the mediastinum is involved.1,2 CCNF diagnosis is based on clinical suspicion. Typical findings include dishwater-like purulence and easy spread of fascial planes using fingers.3 Treatment for CCNF usually consists of aggressive surgical debridement, source control, and intravenous antibiotics. Patients often experience prolonged hospital stays, around 24-33 days1,2 and require 2-5 debridements.1 Hyperbaric oxygen (HBO) has shown promising results as an adjunctive therapy in management. The authors' study reviewed their institution's protocols for CCNF of odontogenic origin and use of HBO in their treatment. MethodsPatients with deep neck fascial space infections of odontogenic origin at Hennepin County Medical Center (HCMC) were included. Inclusion criteria were odontogenic infections involving fascial spaces with a high degree of concern for CCNF based on clinical and radiographic presentation at the time of treatment and/or confirmed CCNF. Exclusion criteria were patients with deep fascial space infections of non-odontogenic source and those who did not receive HBO. Five patients were identified. Data, such as age, gender, length of hospital stay (LOS), intervention by outside providers, hierarchical condition category (HCC), and bacteria species, were recorded for each patient. Descriptive statistics were used to summarize quantitative variables. ResultsFrom 2016 to 2020, 5 patients were identified who had odontogenic infections, with high concern for necrotizing fasciitis based on clinical presentation for CCNF. There were 3 females and 2 males, with an average age of 44.6+/-8.65 years. The mean number of washouts/debridement procedures was 4.4+/-1.25. Patients required on average 3.4+/-0.87 HBO dives. The mean LOS was 18.8+/-6.37 days. Three patients underwent care by an outside provider prior to admission to the hospital, while 2 sought care at an urgent care or emergency department. The HCC for these patients ranged from 0 to 3. All patients grew milleri group streptococcus; 3 patients grew Candida species. No mortalities were recorded. DiscussionThis protocol involved initiating HBO dives within 24 hours of suspected or confirmed CCNF, followed by subsequent daily surgical debridements and HBO sessions. The HBO dives were at 2.8 ATA for 45 minutes followed by staged decompression for a total of 90 minutes. This protocol resulted in shorter LOS. In 1994, a comparative study with a comparable population was completed at this institution, in which HBO was not used for suspected CCNF. This study showed 2.8 average surgical debridements and LOS of 34 days, compared to 18.8+/-6.37 days in the authors' study.4 The increased number of surgical debridements in the authors' series theoretically decreased the bacterial burden, compared to the previous series. HBO theoretically reduced the bacterial burden, improved immune response, and spurred healing. HBO may reduce LOS for CCNF patients and should be considered as adjunctive therapy.

Streptococcus Constellatus Empyema Presenting With Undulant Fever Pattern- A Case Report and Literature Review

Streptococcus anginosus group (SAG), or milleri group streptococci (MGS), is an uncommon group of bacteria that has been increasingly affecting the adult population. It is an interesting organism in that it is intensely pyogenic when pathogenic-much in the same character as Staphylococcus aureus. SAG includes three species: Streptococcus anginosus, Streptococcus intermedius, and <em>Streptococcus constellatus</em>. Members of the SAG are usually part of the indigenous oral, gastrointestinal, and genitourinary flora; however, with mucosal disturbance they can become pathogenic leading to infections.

The intraperitoneal bacteriology and antimicrobial resistance in acute appendicitis among children: a retrospective cohort study between the years 2007-2017.

This study aims to describe the microbiology and susceptibility profile of the intraperitoneal flora in complicated appendicitis. It is a retrospective cohort study including children < 18-year-old with pathologically confirmed appendicitis, from 2007 to 2017. It included 1466 children. Intraperitoneal samples were obtained from 655 (44.7%) patients, and 201 (30.7%) had positive culture with 395 pathogens. Gram-negative rods comprised 67.6%, Gram-positive cocci 21.5%, and anaerobes 10.9% of the isolates. Gram-positive cocci were detected in 67 (37.8%) patients. Milleri group Streptococci was the most frequently isolated Gram-positive (44.7%). The proportional rate of Milleri group Streptococci from Gram-positive cocci increased from 9.5 to 56.3% (P < 0.001, OR 12.214). Patients with Gram-positive cocci had longer hospital stay (mean 9.36 + 6.385 vs 7.72 + 4.582, P = 0.036, (CI -3.165, -0.105)) and more complicated disease (89.5% vs 78.4%, P = 0.045, OR 2.342). Patients with Milleri group Streptococci isolates readmitted more frequently (26.5% vs 13.2%, P = 0.05, OR 2.37). Resistance to amoxicillin-clavulanate, gentamicin, ceftazidime, piperacillin-tazobactam, and amikacin were detected in 29.1%, 6.5%, 2.3%, 1.2%, and 0.7% of the Gram-negative rods, respectively.Conclusion: The rates of Gram-positive cocci and particularly Milleri group Streptococci in peritoneal fluid are increasing. More complicated disease and longer hospital stay in Gram-positive cocci and higher readmission rate in Milleri group Streptococci. These emphasize the role of anti-Gram-positive antimicrobials. What is known: • Gram-negative rods are the main isolates in complicated appendicitis. • The choice of antibiotic regimen is an unsettled issue due to resistance. What is new: • Increased rate of Gram-positive cocci and Milleri group Streptococci. • More complicated disease, longer hospital stay, and higher readmission rate.

1563. Variations in the clinical spectrum of the Streptococcus anginosus group: a report of two rare presentations

BackgroundThe Streptococcus Anginosus Group (SAG) formerly Streptococcus Milleri Group is a subgroup of viridans streptococci including S. anginosus, intermedius, and constellatus. SAG are microaerophilic digestive tract commensals. They are associated with empyema and deep organ abscesses. We present 2 unusual cases: necrotizing fasciitis and aortic valve endocarditis with aortic root abscess, resulting in septic emboli causing renal infarction.MethodsReview of the literature and reported cases of SAG.ResultsCase1) 48 year-old-male with history of HTN, T2DM, presented with swelling and erythema of the right arm of 2-day evolution. Exam: tender, erythematous indurated right deltoid. Significant labs: WBC 25k/uL and lactate of 2.5. CT of the RUE showed an extensive fluid collection. Vancomycin, levofloxacin and clindamycin were initiated, surgical debridement revealed extensive necrotizing fasciitis Wound cultures grew S. constellatus. Required multiple debridement and prolonged course of penicillin G. Case 2) 53-year-old male with history of COPD, Prior Splenectomy for a large splenic infarct, heterozygous factor V Leiden mutation, HCV infection, cirrhosis, presented with right flank pain, hematuria over 5 days. Labs: WBC 16.8 k/uL, CT abdomen with contrast: right renal infarct. Heparin drip, Vancomycin and Ceftriaxone were initiated. Blood cultures grew S. anginosus. TEE revealed new aortic valve vegetations with severe aortic regurgitation. His condition deteriorated, requiring aortic valve surgery, found to have aortic root abscess requiring aortic root replacement.Necrotizing Fascitis - Soft Tissue Air Post-Surgical Debridement Right Renal Infarct ConclusionSAG infections infections are unique from other S viridans, causing severe deep organ abscesses requiring combined surgical and antibiotic therapy. Isolation in clinical specimens should alert the possibility of severe life threatening infections. Here we highlight 2 unusual manifestations of necrotizing fasciitis and aortic valve endocarditis with aortic root abscess and possible large septic renal embolism. One patient had a splenectomy. We are not sure if this contributed to a severe SAG infectionDisclosures All Authors: No reported disclosures

Clinical Characteristics and Outcome Analysis of 94 Children With Brain Abscess in Beijing: A Single-center Retrospective Study.

There are limit studies about pediatric brain abscess in China. The aim of this study was to analyze clinical characteristics and outcomes of pediatric brain abscess in recent years in China. The clinical information of children with brain abscess hospitalized in Beijing Children's Hospital between January 1, 2007 and December 31, 2016 were retrospectively reviewed. Ninety-four children were enrolled in this study. A Streptococcus milleri group (13.8%) was identified as the most common causative organisms, followed by Staphylococcus aureus (6.4%). The overall mortality was 21.6%, with 50.0% of deaths happening in the first week after diagnosis. Long-term outcomes of 74 patients were assessed with Glasgow Outcome Scale-Extended Pediatric Reversion: 50 patients with a score of 1-2 (favorable outcome) and 24 patients with a score of 3-8 (unfavorable outcome). Patients with multiple abscesses (P = 0.029) and intraventricular rupture of brain abscess/hydrocephalus (P = 0.024) had higher risk of unfavorable outcomes. Brain abscess is a serious disease with high mortality in children; more aggressive treatments should be considered in the first week of diagnosis because of high risk of death, and for patients with multiple brain abscesses and intraventricular rupture of brain abscess/hydrocephalus because of their higher risk of unfavorable.

S2749 Streptococcus intermedius Liver Abscesses in a Patient Presenting With Fatigue

INTRODUCTION: Streptococcus intermedius is part of the Streptococcus milleri group. It can be found as part of the normal flora of the oropharyngeal cavity and gastrointestinal tract. Although rare, Streptococcus intermedius can cause hematogenous infection in addition to liver abscesses in healthy patients. We describe a case of Streptococcus intermedius liver abscesses and bacteremia in a patient who presented with fatigue. CASE DESCRIPTION/METHODS: A 73 year old male patient with a past medical history of coronary artery disease and hypertension presented to the hospital with progressively worsening weakness and fatigue in addition to generalized abdominal pain. Patient had a previous history of resolved hepatitis C infection. There was no signs of hepatic decompensation or weight loss. On presentation, patient’s vital signs were within normal limits. Physical exam was remarkable for generalized abdominal tenderness. Labs were significant for a WBC of 12.6 × 109/L and INR of 1.4. Liver function tests were significant for an ALT of 50 U/L and a total bilirubin of 3.1 U/L. A CT of the abdomen and pelvis showed nonspecific sigmoid colitis or diverticulitis. Blood cultures were taken. Patient was started on appropriate antibiotics for suspected diverticulitis. Blood cultures were later positive for Streptococcus intermedius. Liver ultrasound showed multiple small hypoechoic lesions in the liver, and signs of hepatic steatosis. MRI of the abdomen was suggestive of multifocal hepatic abscesses. He was treated with IV ceftriaxone for six weeks followed by Augmentin for 2 two weeks. Follow up MRI one month after initial presentation showed decrease in the size of liver abscesses. Complete resolution of abscesses was seen on MRI a month later. DISCUSSION: Although it is uncommon, Streptococcus intermedius is notorious for causing abscesses with reported cases of brain, lung, and liver abscesses in the literature. It is likely that the bacteremia occurred first followed by abscess formation. The source of the bacteremia is unclear though it is most likely from a GI source in the setting of colitis seen on CT scan in this case. Patient is scheduled for colonoscopy to look for malignancy as the nidus for this infection. He will also undergo cardiac echo to rule out endocarditis although rare. There should be high suspicion for liver abscesses in patients with Streptococcus intermedius bacteremia. Timely diagnosis is important as untreated pyogenic liver abscesses can be fatal.

Paradoxical High-Level Spiramycin Resistance and Erythromycin Susceptibility due to 23S rRNA Mutation in Streptococcus constellatus.

Objectives: The aim of the study was to characterize phenotypically and genotypically an uncommon mechanism of resistance to macrolides, lincosamides, and streptogramins (MLS) in a Streptococcus milleri group clinical isolate. Materials and Methods: The isolate UCN96 was recovered from an osteoradionecrosis wound, and was identified using the matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and the partial sequencing of the sodA gene. Antimicrobial susceptibility testing were carried out by the disk diffusion method and minimal inhibitory concentrations (MICs) were determined by the broth microdilution technique. PCR screening was performed for MLS resistance genes described in Gram-positive bacteria. Specific mutations in the ribosomal proteins L3-, L4-, and L22-encoding genes were also screened and those in domain V of the 23S rRNA gene (rrl). The number of mutated copies of the rrl gene was determined using amplification-refractory mutation system quantitative-polymerase chain reaction (qPCR) analysis. Results: The clinical isolate UCN96 was unambiguously identified as Streptococcus constellatus. It was susceptible to all macrolides and lincosamides (ML) antibiotics except spiramycin (MIC >256 mg/L) while it was also resistant to streptogramins. Screening for all acquired resistance genes was negative and no mutation was found in genes coding for L3, L4, and L22 ribosomal proteins. Of interest, a single mutation, A2062C (according to Escherichia coli numbering), was detected in the domain V of 23S rRNA. Conclusion: Mutations at the position 2062 of 23S rRNA have been detected once in Streptococcus pneumoniae, and not yet in other Streptococcus spp. This mechanism is very likely uncommon in Gram-positive bacteria because different copies of 23S rRNA operons should be mutated for development of such a resistance pattern.

Microbial aetiology of brain abscess in a UK cohort: Prominent role of Streptococcus intermedius

Brain abscess is an uncommon condition, but carries high mortality. Current treatment guidelines are based on limited data. Surveillance of clinical, radiological and microbiology data is important to inform patient stratification, interventions, and antimicrobial stewardship. We undertook a retrospective, observational study of patients with brain abscess, based on hospital coding, in a UK tertiary referral teaching hospital. We reviewed imaging data, laboratory microbiology, and antibiotic prescriptions. Over a 47 month period, we identified 47 adults with bacterial brain abscess (77% male, median age 47 years). Most of the abscesses were solitary frontal or parietal lesions. A microbiological diagnosis was secured in 39/47 (83%) of cases, among which the majority were of the Streptococcus milleri group (27/39; 69%), with a predominance of Streptococcus intermedius (19/27; 70%). Patients received a median of 6 weeks of intravenous antibiotics (most commonly ceftriaxone), with variable oral follow-on regimens. Ten patients (21%) died, up to 146 days after diagnosis. Mortality was significantly associated with increasing age, multiple abscesses, immunosuppression and the presence of an underlying cardiac anomaly. Our data suggest that there has been a shift away from staphylococcal brain abscesses, towards S. intermedius as a dominant pathogen. In our setting, empiric current first line therapy with ceftriaxone remains appropriate on microbiological grounds and narrower spectrum therapy may sometimes be justified. Mortality of this condition remains high among patients with comorbidity. Prospective studies are required to inform optimum dose, route and duration of antimicrobial therapy.

A case report of brain abscess caused by Streptococcus intermedius secondary to sinusitis in 16-year-old adolescents

Background: A brain abscess is a rare but serious complication of sinusitis. It mostly involves adolescents and more specifically those of the male sex. A cerebral abscess is characterized by a heterogeneous clinical picture. The pathogenic organism mostly involved belongs to the Streptococcus milleri group. The diagnosis process is based on imaging. Treatment is based on an antibiotic therapy for 4-8 weeks which can be followed by surgery. Long-term sequelae occur in 40% of the cases, and mortality is about 10%. Case Presentation: This paper reports the clinical case of a 16-year-old boy affected by a sinusitis-induced brain abscess. The worsening of the clinical picture and of the neuroimaging, despite antibiotic therapy, made a surgical intervention necessary. An intravenous antibiotic therapy was administered for 2 weeks followed by oral antibiotics. Despite this, the condition of the patient was worsening, and he had to be treated again with intravenous antibiotic therapy for 4 weeks. This therapeutic choice had a positive outcome and the boy was declared healed. Conclusion: Sinusitis is an infection that can be complicated by brain abscess in 6%-8% of cases. Large-sized cerebral abscesses accompanied by neurological symptoms require prompt surgical treatment and a targeted antimicrobial therapy to reduce hospitalization and to speed up the healing process.

2342 Periodontal Flora Isolated From Pyogenic Liver Abscess in a Retired Dentist With Hepatic Metastasis of Colon Carcinoma

INTRODUCTION: The association of Streptococcus milleri group with pyogenic liver abscess is well recognized. Streptococcus gordonii, however, is a bacterium not of the milleri group and is included among the colonizers of the periodontal environment as it has a high affinity for molecules in the salivary pellicle on tooth surfaces. Here, we describe a case where Streptococcus gordonii was isolated from a pyogenic liver abscess in a retired dentist with hepatic metastasis of colon carcinoma. The clinical features, work up, management, and significance are described. CASE DESCRIPTION/METHODS: An 85-year-old male with colon carcinoma status post hemicolectomy complicated by metastasis to the liver status post chemotherapy and resection presented to the ED with intermittent abdominal discomfort for 2 weeks. Laboratory values were significant for WBC count of 16,000 with a predominance of granulocytes at 85%. CT of the abdomen and pelvis demonstrated a large, 7.6 cm by 5.3 cm, collection in the liver, likely an abscess. Infectious Diseases was consulted and recommended initiation of Meropenem and Daptomycin, in addition to drainage of the collection. The suspected abscess was drained by IR and Streptococcus gordonii sensitive to Linezolid was isolated on bacterial culture. The patient was transitioned to IV Linezolid and Metronidazole given susceptibilities. The patient's WBC count then began trending upwards. CT of the chest exhibited a 1.2 cm by 0.7 cm loculated pleural effusion on the right side. The pleural fluid collection was drained and a chest tube was placed. Studies of the drainage revealed an exudative process, although gram stain and culture were negative. Repeat CT imaging one week later revealed reduction in the size of the liver abscess. The WBC count normalized to less than 10,000 and the patient was discharged with a two-week course of oral Linezolid and Metronidazole with close outpatient follow-up with Infectious Diseases and Oncology. DISCUSSION: Pyogenic liver abscesses are generally associated with enteric gram-negative bacilli, Streptococcus milleri group, Streptococcus pyogenes, and Staphylococcus aureus. Hepatic abscesses secondary to periodontal flora have not been demonstrated in the literature without direct trauma to the GI tract involving foreign bodies contaminated with these organisms. We propose a possible hematogenous route of infection likely associated with possible risk factors related to the patient’s occupation as a dentist and history of dental manipulation.

2486 Pick the Cause: Streptococcus Intermedius and Mitus/Oralis Hepatic Abscess Due to Occult Gastrointestinal Perforation

INTRODUCTION: Abscess bacteria identification directs both evaluation and management. In our case, identification of Strep intermedius and mitus/oralis led to identification of an unsuspected perforation. CASE DESCRIPTION/METHODS: A 45 y/o female presented to the ED with 5 days of fevers to 103.5 F, headache, cramping RUQ abd pain, diarrhea. CT abd revealed a 6.8 cm hypodense septated collection in the liver. Abnormal labs: WBC 32K TBili 1.3 AP 210 ALT 45. History was negative for IVDA, FH and personal hx of IBD, blood in stool, or travel. IR placed a drainage catheter on HD#1 and sent 60 cc purulent material for culture, gram stain with GPC. Culture several days later revealed sensitive Strep intermedius and Strep mitis/oralis in abscess and one anaerobic blood culture. The patient was treated with vancomycin and zosyn. Echocardiogram HD#3 showed minimal mitral calcification and no vegetations. Despite appropriate antibiotics, the RUQ pain, fevers, and WBC persisted. Repeat CT Abd on HD#7 showed a second hepatic abscess (IR placed second drain) and new pelvic abscess measuring 3.5 × 6 cm. On HD#9 we pursued occult GI causes of the persistent infection. Colonoscopy revealed a 1 cm adenoma (snared/removed) with no colon cancer, perforation, or IBD. EGD revealed a toothpick embedded in the prepyloric stomach; this was removed by snare. The patient did not recall eating food with a toothpick or swallowing one. Patient was discharged to home on HD # 11 with a PICC line to complete Unasyn course. Drainage catheters were removed 29 days after initial presentation; repeat CT scan at 52 days revealed no residual hepatic or pelvic abscess collections. DISCUSSION: Streptococcus intermedius is one of the members of the S. milleri group, which are normal flora in the mouth and gastrointestinal tract. S. milleri may cause liver, pelvis, and subphrenic abscess, cholangitis, peritonitis, and appendicitis. Presence of S. millerigroup bacteremia should direct attention to exclusion of occult abdominal perforation or infection, distant focal suppurative infection, and infective endocarditis. Streptococcus mitus/oralis is a common oral bacteria in the Strep viridans group; this may cause a variety of infections including cerebral, epidural, and liver abscesses and endocarditis. Upon the identification of Strep intermedius as the main abscess pathogen in our patient, prompt search for occult abdominal perforation and removal of the foreign body from the perforation tract resulted in resolution of both symptoms and infection.

MASSIVE LUNG ABSCESS DUE TO STREPTOCOCCUS INTERMIDIUS IN AN IMMUNOCOMPETENT PATIENT

SESSION TITLE: Monday Fellow Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Streptococcus intermidius (SI) is a gram positive bacterium which is a part of the oral, respiratory, urogenital as well as gastrointestinal flora. We present a case of a massive lung abscess with severe acute respiratory distress syndrome (ARDS) requiring veno-venous extracorporeal membrane oxygenation (V-v ECMO) in an immunocompetent patient. CASE PRESENTATION: A 54-year-old male patient with past history of diabetes mellitus presented with shortness of breath and fever. The patient was found to have tachycardia, tachypnea and low blood pressure. A Chest radiograph showed a large dense appearing mass like lesion in the right lung (Figure 1)and a CT scan was performed. The scan showed a 14 cm lung abscess with dense necrotic material (Figure 2&3). The patient decompensated and required emergent intubation with a bedside drainage of the lung abscess and placement of a chest tube. Cultures on the aspirated material grew Streptococcus Intermidius. The patient was started on antibiotics Cefepime and Metronidazole. The patient developed severe ARDS and required the V-v ECMO. The V-v ECMO was explanted after 6 days. Over the course of his stay, the chest tube continued to drain purulent material with a continued air leak. The patient underwent a right lung decortication by a video assisted thoracoscopic surgery (VATS). Due to the prolonged intubation and a likelihood of failure of weaning a tracheostomy was performed. The patient was discharged to a rehabilitation facility with a month long course of Cefepime and Metronidazole. On a 12 month follow up the patient was doing well and the tracheostomy had been successfully decanulated. DISCUSSION: Streptococcus intermidius is a gram positive bacterium that belongs to the Streptococcus Millieri group (SMG). Streptococcus intermidius is usually associated with infections of the head, neck and respiratory tract and have a tendency to cause abscesses (1). Infections with SI a commoner in individuals with uncontrolled or undiagnosed diabetes, malignancy or intravenous drug use. Individuals with poor oral hygiene and dental caries are also at risk for getting SI infections (2). Multiple sites for infections are reported in literature including brain, lung, liver and head /neck region abscesses. A multiplex polymerase chain reaction (PCR) may aid in early detection of SI, while cultures can take over a week to grow. A study of the antibiotic sensitivities of SMG showed excellent susceptibility to Penicillin, Ampicillin and Ceftriaxone (3). However, penetration of the drugs into the abscess and necrotic material remains poor and surgical drainage and decortication is usually required. CONCLUSIONS: Streptococcus Intermidius is an important cause of empyema, early diagnosis and treatment is imperative to limit significant morbidity and mortality. Reference #1: Reddy S, Singh K, Hughes S. Liver Abscesses Caused by Streptococcus intermedius in an Immunocompromised Patient. Cureus. 2018;10(1):e2107. Published 2018 Jan 24. https://doi.org/10.7759/cureus.2107 Reference #2: Ramhmdani S, Bydon A. Streptococcus intermedius: an unusual cause of spinal epidural abscess. J Spine Surg. 2017;3(2):243-249. Reference #3: Tracy M, Wanahita A, Shuhatovich Y, Goldsmith EA, Clarridge JE, Musher DM. Antibiotic susceptibilities of genetically characterized Streptococcus milleri group strains. Antimicrob Agents Chemother. 2001;45(5):1511-4. DISCLOSURES: No relevant relationships by Yizhak Kupfer, source=Web Response No relevant relationships by Ravikaran Patti, source=Web Response No relevant relationships by Vignesh Ponnusamy, source=Web Response No relevant relationships by Chanaka Seneviratne, source=Web Response No relevant relationships by Ankur Sinha, source=Web Response No relevant relationships by Parita Soni, source=Web Response No relevant relationships by Taek Sang Yoon, source=Web Response

Clinical characteristics and treatment outcomes in a cohort of patients with pyogenic and amoebic liver abscess

BackgroundWe describe the clinical features of a cohort of patients with liver abscesses and investigate relationships between clinical, radiological and microbiological findings and mortality.MethodsRetrospective review of pyogenic (PLA) or amoebic liver abscesses (ALA) diagnosed and treated at a major infectious diseases department in London over 9 years.ResultsOne hundred forty-one patient records were identified; 132 (93.6%) had PLA and 9 (6.4%) ALA. No organism was identified in 38.6% (51/132); a single bacterial species was isolated in 47.0% (62/132) of PLA, ≥ 2 in 14.4% (19/132). There was weak evidence of variation in abscess size by type of microorganism, with streptococcal PLA typically larger (p = 0.03 for Streptococcus milleri group, p = 0.05 for non-milleri streptococci). Patients with ALA were younger (median 41, IQR 37–51 years) than those with PLA (median 68, IQR 50.5–78 years) (p = 0.003) and all were male (9/9, 100%, (p = 0.03)), with a history of recent travel in the majority (6/9, 66.7% (p = 0.003)). C-reactive protein was higher in ALA than in PLA (p = 0.06). In the entire cohort, loculation (HR = 2.51 (95% CI 1.00–6.32), p = 0.04) and baseline ALP (HR = 4.78 (95% CI 1.19–19.2) per log10 increase, p = 0.03) were associated with mortality. 16S ribosomal RNA (rRNA) analysis was used in a subset of culture-negative cases and increased the diagnostic yield by 13%.ConclusionsClinical or radiological features cannot be used to distinguish between PLA and ALA, or help identify the bacterial cause of PLA. However, ALA is more common in young, male patients with a history of travel. 16S rRNA analysis of abscess fluid has a role in improving microbiological diagnosis in culture-negative cases.