Uncommon Organisms Research Articles

Uncommon Organisms in Neonatal Meningitis: Two Case Reports

These case reports describe two neonates, born at term, diagnosed with bacterial meningitis and septicemia caused by uncommon organisms. The clinical presentation, diagnostic reasoning, national guidelines, hospital course, and follow-up are discussed. Meningitis is among the differential diagnoses when there is a concern for neonatal sepsis. Concern for sepsis can arise from a variety of antepartum, intrapartum, and postpartum risk factors and present with a variety of symptoms. Neonatal sepsis is a significant cause of mortality, with 750,000 infant deaths annually. Effective treatment of neonatal sepsis requires timely diagnosis and tailored antimicrobial therapy that targets the causative pathogens.

ThTP8.5 Bacterial profile and antimicrobial susceptibility patterns of isolates among patients diagnosed with surgical site infection at a tertiary teaching hospital in Pakistan

Abstract Objective The study aimed at assessing the bacterial profile and antimicrobial susceptibility patterns of the pathogens isolated from patients diagnosed with surgical site infection. This study will help identify the organisms and will guide in formation of protocols to prevent and treat surgical site infections. Methods This descriptive cross-sectional study was conducted in the Department of Surgery from May 2021 to May 2022, using convenient sampling technique. Wound samples were taken from patients diagnosed with surgical site infection and cultured on Blood and MacConkey agar. Antimicrobial susceptibility was performed on Muller Hinton agar. Data was entered and analyzed using SPSS v.23. Results A total of 101 samples from 78 patients were analyzed. Out of the bacteria from positive growth cultures, Escherichia coli (19,18.8%) was the most common isolate followed by Pseudomonas aeruginosa (17,16.8%) and Klebsiella pneumoniae (15,14.9%). Acenitobacter baumanni was isolated from 11 (10.9 %) patients, methicillin-resistant Staphylococcus aureus from 4 (4 %) patients and Proteus mirabilis from 2 (2 %) patients. However, 9.9% samples showed no growth on cultures. Escherichia coli was the most sensitive to amikacin (89.5%) and meropenem (78.9%). While Pseudomonas aeruginosa showed maximum susceptibility towards meropenem (82.4%). Conclusion Escherichia coli was the most commonly isolated pathogen from surgical site infection sites, followed by Pseudomonas aeruginosa, Klebsiella pneumoniae and Acenitobacter baumanni as causative agents for SSI’s. This study demonstrates the increasing incidence of infections from once uncommon organisms like Klebsiella pneumoniae and Acenitobacter baumanni. This calls for action and formation of protocols to fight the menace of SSI’s.

High Diversity of Fusarium Species in Onychomycosis: Clinical Presentations, Molecular Identification, and Antifungal Susceptibility

Fusarium are uncommon but important pathogenic organisms; they cause non-dermatophyte mould (NDM) onychomycosis. Patients typically respond poorly to treatment owing to Fusarium's native resistance to multiple antifungal drugs. However, epidemiological data for Fusarium onychomycosis are lacking in Taiwan. We retrospectively reviewed the data of 84 patients with positive Fusarium nail sample cultures at Chang Gung Memorial Hospital, Linkou Branch between 2014 and 2020. We aimed to investigate the clinical presentations, microscopic and pathological characteristics, antifungal susceptibility, and species diversity of Fusarium in patients with Fusarium onychomycosis. We enrolled 29 patients using the six-parameter criteria for NDM onychomycosis to determine the clinical significance of Fusarium in these patients. All isolates were subjected to species identification by sequences and molecular phylogeny. A total of 47 Fusarium strains belonging to 13 species in four different Fusarium species complexes (with Fusarium keratoplasticum predominating) were isolated from 29 patients. Six types of histopathology findings were specific to Fusarium onychomycosis, which may be useful for differentiating dermatophytes from NDMs. The results of drug susceptibility testing showed high variation among species complexes, and efinaconazole, lanoconazole, and luliconazole showed excellent in vitro activity for the most part. This study's primary limitation was its single-centre retrospective design. Our study showed a high diversity of Fusarium species in diseased nails. Fusarium onychomycosis has clinical and pathological features distinct from those of dermatophyte onychomycosis. Thus, careful diagnosis and proper pathogen identification are essential in the management of NDM onychomycosis caused by Fusarium sp.

Metagenomic Next-Generation Sequencing for Diagnosis of Pulmonary Infections

Despite pneumonia being a leading cause of morbidity and mortality worldwide, diagnostics remains a challenge, hindering rapid organism identification and subsequent effective treatments. Current microbiological methods include culture, serology, and limited molecular panels. While helpful, these methods are unable to address the full range of potential pathogens (e.g., fastidious or noncultivable organisms or uncommon organisms not included in current panels). Metagenomic next-generation sequencing (mNGS) is a molecular technique that analyzes and compares the nucleic acid content in a patient sample to a reference database of organisms that may include bacteria, viruses, fungi, and/or parasites, depending on the mNGS technology used. By bypassing the limitations of culture and targeted molecular assays, mNGS offers the potential to identify countless organisms directly from a patient specimen to aid in the diagnosis of an infectious process. Although promising, mNGS does have considerable limitations related to cost, interpretation, standardization, clinical relevance, turnaround time (TAT), and widespread availability. Thus, these factors should be considered prior to implementing mNGS for clinical use. Moreover, additional studies are required to fully understand the clinical and epidemiological impact of mNGS for the diagnosis of infectious diseases, including respiratory infections.

A RARE CASE OF LEMIERRE'S SYNDROME CAUSED BY PREVOTELLA BUCCAE

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Jugular vein septic thrombophlebitis, also known as Lemierre's Syndrome (LS), is an extremely rare complication that is secondary to an acute oropharyngeal infection with retropharyngeal extension and metastatic spread. The disease was first described in 1936 and the incidence of this condition is approximately 0.8 people per million per year with a high mortality rate close to 24%. The most commonly isolated pathogen is Fusobacterium necrophorum, a common oral flora. Management depends on the initial presentation, type of pathogen isolated, and proper selection of antibiotics. CASE PRESENTATION: 67-year-old man with past medical history of coronary artery disease, hypertension and diabetes mellitus presented to the emergency department with a one-week history of anorexia and dysphagia. Patient denied fever, chills or shortness of breath. Vital signs remarkable for tachycardia. Physical examination remarkable for pharyngeal erythema and palpable neck mass, no evidence of exudates, no palpable lymphadenopathy. Neck CT Scan with IV contrast remarkable for complex enhancing fluid collection with phlegmonous inflammatory changes involving the left parapharyngeal space, carotid space, jugular chain and posterior neck triangle space with infiltration into the left jugular vein with intraluminal thrombosis which likely represents superimposed septic thrombophlebitis. Chest CT Scan with IV Contrast remarkable for left lower lobe atelectasis, consolidation with empyema. Management included intravenous antibiotics and thoracenthesis for his left side empyema. Neck abscess was drained. Due to persistent empyema a left side thoracotomy and total decortication was performed, leading to resolution of empyema. Final blood and abscess culture were remarkable for Prevotella buccae, which supported the diagnosis of LS. His condition improved and he was discharged with proper antibiotic coverage and outpatient follow-up. DISCUSSION: LS is a rare condition associated with metastatic infection spreading. This syndrome can be associated with further complications, such as pleural effusions and/or empyema as seen with our patient. Early suspicion and recognition are important to prevent fatal complications and provide adequate antibiotic coverage early on during treatment. Most patients with LS present with a pharyngitis-like picture and pulmonary symptoms. Our patient presented with an unusual clinical presentation when compared to other reports of LS and abscess culture was positive to an uncommonly involved organism. CONCLUSIONS: We present an effective multidisciplinary approach to the treatment of LS with associated ipsilateral empyema. We encourage to have a high level of suspicion of this syndrome in patients presenting with neck abscess, even though, they present with minimal symptoms and with uncommon organisms. This will prevent deterioration of the condition and will permit adequate treatment. REFERENCE #1: Valley, Thomas Sebastian MD*; Sheshadri, Ajay MD†; Hoopman, Todd C. MD‡ A Young Man With Empyema, Infectious Diseases in Clinical Practice: November 2011 - Volume 19 - Issue 6 - p e31-e32 doi: 10.1097/IPC.0b013e31822e9be3 REFERENCE #2: Wani, P., Antony, N., Wardi, M., Rodriguez-Castro, C. E., & Teleb, M. (2016). The Forgotten One: Lemierre's Syndrome Due to Gram-Negative Rods Prevotella Bacteremia. The American journal of case reports, 17, 18–22. https://doi.org/10.12659/ajcr.895560 REFERENCE #3: Lemierre A. On certain septicemias due to anaerobic organisms. Lancet. 1936;227(5874):701–3. DISCLOSURES: No relevant relationships by Daniel Font-Rivera, source=Web Response No relevant relationships by Sandra Galarza-Vargas, source=Web Response No relevant relationships by Emanuel Mejias Lafontaine, source=Web Response No relevant relationships by Claudia Quiles, source=Web Response

RARE PATHOGEN LINKED TO GUILLAIN-BARRÉ SYNDROME AND RESPIRATORY FAILURE

TOPIC: Critical Care TYPE: Fellow Case Reports INTRODUCTION: Guillain Barre Syndrome (GBS) is a rapidly progressive peripheral neuropathy that presents as diminished deep tendon reflex with ascending symmetrical weakness of the lower extremities, secondary to a gastrointestinal or respiratory illness. Incidence is more common in males and range from 1 to 3 out of 100,000 cases per year. Approximately 10 to 30% of patients required mechanical ventilation. Potential triggering events include trauma, immunization, surgery, and infections by organism such as Campylobacter, Cytomegalovirus, Mycoplasma pneumonia, Epstein Barr virus and HIV. CASE PRESENTATION: A 75-year-old male with medical history of peripheral vascular disease and diabetes mellitus type 2, who arrive to the emergency unit with 1 day evolution of vomiting, bloody diarrhea, and general malaise. He denies fever, chills, chest pain, shortness of breath, cough, abdominal pain, dysuria, sick contacts, or recent travel. The patient refers recent ingestion of street meat tacos. Physical examination remarkable for right lower extremity above the knee amputation, hypotension, and tachycardia. He was admitted to intensive care unit with septic shock and started on broad spectrum antibiotics. The gram stain show gram negative bacilli bacteria, with a gull wing shape, similar in morphology to the Campylobacter species. On fourth day of admission, he developed hypoactivity, hypercapnic respiratory failure requiring mechanical ventilation. His neurological examination was remarkable for generalized areflexia and marked distal more than proximal upper extremity weakness. Lumbar puncture (LP) was performed, and results correlated with this diagnosis of GBS. Final blood and stool cultures showed Anaerobiospirillum succiniproducens. The organism was initially confused with Campylobacter species due to morphological similarities. DISCUSSION: Two known Anaerobiospirillum sp. infect humans, A. thomassi which cause diarrhea and A. succiniproducens which is a motile, gram-negative, spiral anaerobe with flagella and is a rare cause of diarrheal illness and bacteremia in humans. McNeil et al showed that 17 of 22 patient had gastrointestinal symptoms and suggest that the gastrointestinal tract was likely the portal of entry. A. succiniciproducens have been isolated from rectal swabs of cat and dogs but not in humans. The optimal antimicrobial treatment for A. succiniciproducens still remains to be determined. CONCLUSIONS: This case is intended to arise medical awareness of this uncommon organisms, Anaerobiospirillum succiniproducens, which may lead to GBS. Early diagnosis and treatment with immunoglobulins are required to reduced neurological disability and risk of respiratory failure. Nerve conduction testing, along with albuminocytologic dissociation serves as helpful diagnostical studies, still clinical suspicion is important in atypical cases. REFERENCE #1: Epstein DAJ, Anaerobiospirillum succiniproducens bacteremia and pyomyisitis. Journal of Clinical Microbiology 55:665-669 REFERENCE #2: Kelesidis T, Bloodstream Infection with Anaerobiospirillum succiniciproducens: A Potentially Lethal Infection. South Med J. 2011 Mar;104 (3): 205-214 REFERENCE #3: McNeil MM, Martone WJ, Dowell VR, Jr. Bacteremia with Anaerobiospirillum succiniciproducens. Rev Infect Dis1987;9:737–42. DISCLOSURES: No relevant relationships by Onix Cantres-Fonseca, source=Web Response No relevant relationships by Marlene Farinacci Vilaro, source=Web Response No relevant relationships by Vanessa Fonseca Ferrer, source=Web Response No relevant relationships by Luis Gerena Montano, source=Web Response No relevant relationships by SULIMAR MORALES, source=Web Response No relevant relationships by William Rodriguez-Cintron, source=Web Response

Microbiological Profile and Sensitivity Data among the Neonatal Population from a Tertiary Care Hospital in South India

Background: Sepsis is one of the most common causes of mortality and morbidity among neonates. The prevalence of microorganisms varies with regions, and the sensitivity pattern also changes over time. 
 Aim: To study the prevalence of various microorganisms and their sensitivity pattern among the neonatal population in a tertiary care hospital in South India.
 Methods: This was a retrospective descriptive study. We screened the records of all neonates admitted to the hospital during a period starting from January 1st, 2016, to September 30th, 2018. The details of the patients with any sterile body fluids showing microbial growth were collected. Descriptive analysis was done using IBM SPSS version 20.
 Results: There were 77 organisms isolated during the study period, with the majority among outborn babies. Seventy-two isolates were from blood, two from CSF and urine, with one from the central line. The most common organism was Klebsiella (22%), followed by Burkholderia cepacia (12%), Staphylococcus aureus (9%), and Streptococcus agalactiae (7%). 9% of the organisms were fungus, with the most common being Kodamaea Ohmeri. Among the antibiotics tested for sensitivity, Meropenem had the maximum sensitivity ratio (84%), followed by Co-trimoxazole (83%) and Vancomycin (82%). Piperacillin tazobactam sensitivity was only 56%, and Ciprofloxacin was sensitive in 65% of cases. Most (6 out of 7) of the fungal isolates were sensitive to fluconazole.
 Conclusions: Klebsiella remains to be the most common organism causing severe infection in young infants. Worrying rise in the incidence of uncommon organisms (like Kodamaea Ohmeri, GBS, Burkholderia) and carbapenem resistance was noted. It is, therefore, essential to update the antibiotic policy of the neonatal units on a timely basis.

First reported case of penile prosthesis infection from brucellosis: case report

BackgroundInfection after the penile prosthesis can be devastating to both the patient and surgeon with various complications and consequences. After introduction of antibiotic-coated implants, the rate of infection has dramatically decreased, but still we see uncommon organisms causing infection. We present a first case report of penile prosthesis infection by brucellosis due to raw milk ingestion. To our knowledge, this is the first reported case of brucellosis penile prosthesis infection.Case presentationWe present a first case report of penile prosthesis infection by brucellosis due to raw milk ingestion. A 75-year-old, diabetic male patient presented with penile prosthesis infection 5 months post-penile exchange surgery due to mechanical malfunctioning of 2-piece penile prosthesis which was inserted 11 years ago. The initial treatment with broad spectrum antibiotics did not subside the infection. After diagnosis of brucellosis, the antibiotic was changed to anti-brucellosis (Rifampicin + Tetracycline). The patient improved dramatically and was discharged home with smooth follow-up course.ConclusionBrucellosis can cause infection of penile prosthesis and can be treated with anti-brucellosis antibiotics without necessitating surgical intervention and removal of prosthesis.

Benign parotid mass and facial palsy: systematic review.

Parotid masses causing facial palsy are highly indicative of malignancy. A significant number of cases describing benign parotid disease causing facial palsy have been reported. We performed a systematic review of the literature to establish the aetiology, clinical features, investigations and management undertaken during these presentations to assess how these factors differed from malignant presentations and to establish an evidence-based algorithm for their management. A total of 85 cases were identified from 78 articles. Cystadenolymphomas were the most common histopathological type (p = 0.034). Mean facial palsy recovery duration in neoplastic aetiology was longer than for infective aetiology (p = 0.033). A significant association existed between uncommon infective organisms and development of facial palsy (p = <0.0001). Uncommon benign aetiologies are associated with facial palsy. Investigations and management should be guided by patients' clinical presentations, avoiding excessive treatment. Complete facial palsy recovery rates are high, although not immediate.

Insights for the Growth of Stenotrophomonas maltophilia in a Diabetic Patient with Long-Term Antibiotic Use: A Case Study.

Stenotrophomonas maltophilia is an uncommon gram-negative bacterium often found in individuals with long-standing broad-spectrum antibiotic use or catheter use; individuals undergoing hemodialysis; and individuals with prolonged respiratory disease, specifically, cystic fibrosis. To our knowledge, there are few reported cases of S maltophilia being the causative pathogen of infection in a diabetic foot wound. Following multiple surgical procedures and deep tissue cultures, S maltophilia was determined to be a secondary opportunistic colonizer of the wound, necessitating a change in antibiotic therapy. The cultured pathogen was sensitive to ceftazidime, levofloxacin, and trimethoprim-sulfamethoxazole. The treatment team chose to use ceftazidime, as it also provided antibiotic coverage for the initial wound and blood cultures. Change in antibiotic therapy was initiated following multiple surgical procedures and angioplasty of the lower limb. The patient was discharged with a peripheral intravenous central catheter for outpatient antibiotic therapy. Prolonged exposure to broad-spectrum antibiotics in individuals with multiple comorbidities including diabetes mellitus provides an advantageous environment for growth of uncommon multidrug-resistant organisms. Stenotrophomonas maltophilia may complicate the treatment of diabetic foot infections as an opportunistic pathogen. Understanding the implication of long-term broad-spectrum antibiotic treatment in the diabetic patient is important in managing postoperative complications and determining the correct course of treatment. The emergence of atypical pathogens in diabetic wounds must be managed appropriately.

Listeria spondylodiscitis: an uncommon etiology of a common condition; a case report

BackgroundListeriosis is a severe food-borne infection caused by the Gram-positive rod, Listeria monocytogenes. Despite the low incidence (3–8 cases per million), Listeriosis has a case fatality rate of 20–30% as it occurs predominantly in immunocompromised individuals at extremes of age, diabetics and pregnant women. Listeriosis classically presents as a febrile gastroenteritis, isolated bacteremia, meningitis, or maternal-fetal infections. Focal bone and joint infection are rare and primarily involve orthopedic implant devices. Here, we present the first case of Listeria-associated spondylodiscitis.Case presentationA 79-year-old male presents with acute-on-chronic back pain in the absence of risk factors or exposures, aside from age. On radiological imaging, spondylodiscitis of L3-L4 was diagnosed. Subsequently, a CT-guided biopsy was performed to aid in confirming microbiological aetiology. Listeria monocytogenes was grown in culture and patient received appropriate antibacterial therapy.ConclusionThe case highlights the utility of image-guided tissue sampling in aiding diagnosis and management in patients with vertebral osteomyelitis. It also encourages consideration of uncommon organisms such as Listeria as an etiology of vertebral osteomyelitis, even in the absence of prosthetic implants.

Peritonitis from facultative anaerobic gram-negative bacilli likely due to translocation of bacteria from gut in a patient undergoing peritoneal dialysis.

The peritonitis caused by gram-negative organisms is a serious complication encountered in patients undergoing peritoneal dialysis, often causing high morbidity and mortality. There has been recognition of peritonitis caused by uncommon organisms because of improved microbiological detection techniques. The healthcare providers involved in the management of these patients should be very vigilant. We report a rare case of peritonitis caused by Citrobacter freundii. A 42-year-old male on peritoneal dialysis for five years presented with abdominal pain and cloudy effluent. The peritoneal fluid analysis was consistent with peritonitis, and peritoneal fluid culture grew Citrobacter freundii. The patient was treated with two courses of double antibiotic coverage with intraperitoneal ceftazidime and oral ciprofloxacin, which failed to resolve the infection and hence resulted in the removal the peritoneal dialysis catheter and dialysis modality change.

Unravelling the benefits and barriers to utilising whole-genome sequencing in the investigation of outbreaks

Background This prospective study was established to develop and evaluate methods to harness pathogen sequencing in the clinical microbiology environment. We describe new insights into the clinical benefits of using whole-genome sequencing (WGS) for outbreak investigation with solutions for the practical barriers to implementation in clinical settings. Methods Surveillance software (ICNet) and statistical process control charts (SPCs) detected potential outbreaks of meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenem-resistant Enterobacteriaceae (CRE), Enterobacteriaceae producing extended spectrum β-lactamases (ESBLs), Listeriaspp. and optrAgene positive enterococci. Isolates were sent to reference laboratories for conventional typing and the Infection Group, School of Medicine, University of St Andrews for WGS (Illumina Inc, San Diego, CA, USA) and bioinformatic data analysis. Results Over 400 isolates have been sequenced to date. WGS replaced multiple typing techniques in a Pseudomonas aeruginosa ICU outbreak. It confirmed two patient’s Listeria spp. isolates were indistinguishable prompting hospital kitchen inspections, identified a patient to be carrying two strains of VRE and confirmed that vancomycin-sensitive Enterococcus faecium isolates related to a VRE cluster. We observed five main barriers to implementing WGS (infrastructure, performance/quality assessment of data, isolate selection, clinical result interpretation and database management). Conclusion WGS is beneficial in outbreaks of uncommon organisms and when conventional typing cannot show whether isolates are linked or not. Identifying barriers assisted us in developing a clinical decision aid that can be used by clinicians when applying WGS to outbreak investigations.

448. Impact of Doxycycline Prophylaxis on Skin and Soft-Tissue Infection Incidence in Naval Special Warfare Trainees

BackgroundSkin and soft-tissue infections (SSTIs) are a common complication of military training. Naval Special Warfare (NSW) training requires prolonged periods of extreme physical exertion and unique environmental exposures, including extended immersion in ocean water. A centerpiece of SEAL training is referred to as “Hell Week” (HW), a colloquial term to reflect the intense physical obstacles and exposure to extreme environmental conditions endured by candidates. Due to such environmental exposures, NSW trainees are at increased risk for SSTI due to uncommon organisms. A prior outbreak of Shewanella SSTI and bacteremia among NSW trainees led to the initiation of prophylactic doxycycline 100 mg daily during and for 7 days after HW to attempt to reduce this risk. The efficacy of this intervention is undetermined.MethodsDoxycycline prophylaxis was initiated in August 2015. We conducted a retrospective analysis of SSTI incidence presenting for medical attention among NSW trainees from April 2013 to November 2018, using case records collected prospectively at the Naval Special Warfare Center. The incidence of SSTI was calculated based on the size of a given class and the number of affected trainees. SSTI cases were then divided and analyzed as occurring during vs. after HW.ResultsThe pre-intervention cohort consisted of 1626 NSW trainees. A total of 76 trainees developed SSTI, with 20 cases during HW and 56 cases in the post-HW period. In the post-intervention cohort, 2022 trainees experienced a total of 81 cases of SSTI during HW and 83 in the post-HW period. 45% of all SSTI cases occurred in the months of June, July, and August. The incidence of cellulitis between the pre- and post-intervention cohorts during HW was 2% and 4%, respectively, and 5% and 6.4% in the post-HW period. There were no hospitalizations for invasive gram-negative infections following the initiation of doxycycline prophylaxis.ConclusionDoxycycline prophylaxis does not appear to reduce the incidence of SSTI but may reduce the incidence of certain severe infections. The choice of antibiotic prophylaxis and dosing may require further investigation. Seasonality of SSTI among NSW trainees is an unexpected finding and may provide valuable information for the prevention of future illness. Disclosures All authors: No reported disclosures.

1309 Multi-Drug Resistant Burkholderia Cepacia Infected Pancreatic Pseudocyst

INTRODUCTION: Burkholderia Cepacia is a gram negative bacillus that is most commonly associated with pneumonia in the immunocompromised, most specifically in the cystic fibrosis population. Pancreatic cysts have about 13.5% prevalence and are classified between non-neoplastic and neoplastic. Infected pseudocysts are non-neoplastic and a complication of pancreatitis. CASE DESCRIPTION/METHODS: A 45-year-old male with a past medical history of substance abuse, diabetes mellitus, and acute pancreatitis two weeks prior to admission presented to the ED unresponsive and hypoglycemic. Vitals were stable and physical exam was unremarkable on admission. With increased alertness he began endorsing epigastric abdominal pain, back pain, and early satiety. He then became febrile. Initially his labs were significant for: total bilirubin of 1.6 mg/dL, ALT 46 U/L, AST 65 U/L, and alkaline phosphate of 357 U/L. During the course of admission, his abdominal pain and satiety worsened, and his abdomen became distended. He became septic without a clear source. He underwent CT A/P, which demonstrated an 18.5 × 10.3 cm pseudocyst containing debris, thought to be a complication from his recent pancreatitis. The patient underwent CT guided biopsy for drainage and cultures, which grew MDR B. Cepacia. He was also found to have B. Cepacia bacteremia. The patient was started on Ceftazidime for a 2-month course. Unfortunately, after drainage the patient continued to have symptoms and his bilirubin peaked at 5.9 mg/dL and AP peaked at 1855 U/L. This led to a cyst gastrostomy stent placement via EUS. Two weeks later, a biliary sphincterotomy was performed by ERCP with stent removal and a single segmental biliary stricture was found in the lower and middle third of the main bile duct. Repeat CT A/P two weeks after the ERCP and one month after the start of antibiotics, showed a decrease in the size of the cyst to 8.5 × 3.2 cm and the patient's symptoms were improving. DISCUSSION: This was a unique case of a common complication of pancreatitis. Although infected pseudocysts are associated with mixed anaerobes and aerobes, B. Cepacia has not been commonly reported. To the best of our knowledge, this is the first case to be associated with B. Cepacia infected pseudocyst. As such, there is value in including uncommon MDR organisms in the differential for infected pseudocysts. Moreover, as this patient was immunocompetent, this poses an area of future study, as this patient's IVDA history may be an essential risk factor for these organisms.

1375. In vitro Activity of Cefiderocol and Comparator Agents against Gram-Negative Isolates from Cancer Patients

BackgroundGram-negative bacilli (GNB) are now the predominant cause of bacterial infection in cancer patients (CP). Many GNB are problematic because they have become resistant to commonly used antibiotics. Cefiderocol (CFDC), a novel siderophore cephalosporin, is active against a wide spectrum of GNB. We evaluated its in vitro activity and that of eleven comparator agents against GNB isolated from CP.MethodsA total of 341 recent GNB blood isolates from CP were tested using CLSI approved methods for MIC determination by broth microdilution. Comparator agents were amikacin (A), aztreonam (AZ), ceftazidime (CZ), ceftazidime/avibactam (CAV), cefepime (CEF), ciprofloxacin (CIP), colistin (CL), meropenem (MR), ceftolozane/tazobactam (C/T), tigecycline (TG), and trimethoprim/sulfamethoxazole (T/S).ResultsCFDC MIC90s as mg/L were: S. maltophilia [50 isolates] 0.25, E. coli (ESBL−) [50 isolates] 0.5, E. coli (ESBL+) [51 isolates] 2.0, K. pneumoniae (ESBL− and +) [60 isolates] 0.5; K. pneumoniae (CRE) [22 isolates] 2.0; P. aeruginosa (MDR) [32 isolates] 1.0; E. cloacae [27 isolates] 4.0; Achromobacter spp. [15 isolates] 0.12. CFDC inhibited P. agglomerans, Burkholderia spp., Sphingomonas spp., Ochrobactrum spp. at ≤1 mg/L [23 total isolates] and Elizabethkingia spp. and R. radiobacter at ≤8 mg/L [11 total isolates]. Among comparator agents, only T/S had consistent activity against S. maltophilia. For E. coli (ESBL− and +) MR, TG, CAV, CL were most active. For K. pneumoniae (ESBL–and +) MR, CAV were most active. For K. pneumoniae (CRE) and P. aeruginosa (MDR), none of the comparators had significant activity. For E. cloacae, MR, A, CAV, TG were most active. Among the uncommon organisms, MR and TG had the greatest activity.ConclusionAlthough susceptibility breakpoints have yet to be determined, CFDC has significant activity (≤4 mg/L) against most problematic Gram-negative organisms causing infections in CP based on available pharmacokinetic/pharmacodynamic data. In particular, its activity against S. maltophilia was superior to the comparators. Also, it was the most active agent against P. aeruginosa (MDR) and K. pneumoniae (CRE). Based on our results, CFDC warrants clinical evaluation for the treatment of blood stream infections caused by GNB in CP.Disclosures K. V. I. Rolston, Merck: Investigator, Research grant; JMI Laboratories: Investigator, Research grant; Shionogi (Japan): Investigator, Research grant. B. Gerges, Shionogi: Collaborator, Research support. S. L. Aitken, Shionogi: Scientific Advisor, Consulting fee; Merck: Scientific Advisor, Consulting fee; Medicines Co: Scientific Advisor, Consulting fee; Achaogen: Scientific Advisor, Consulting fee; Zavante: Scientific Advisor, Consulting fee; R. Prince, Shionogi: Investigator, Research support. Merck: Investigator, Research support.

The impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay, and reoperation rate in elective spine surgery

Background ContextThere is growing concern that the microbial profile of surgical site infection (SSI) in the setting of prophylactic vancomycin powder may favor more resistant and uncommon organisms. PurposeTo demonstrate the impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay (LOS), and reoperation rate in spine surgical site infection. Study Design and/or SettingRetrospective cohort study. Patient Sample: the study included 115 postoperative spine patients who were required to return to the operating room for SSI. Outcome MeasuresThe outcome measures were microbial profile, reoperation rate, antibiotic regimen, and LOS for patients with postoperative spine infection who either did (treated) or did not (untreated) receive prophylactic vancomycin powder during their index procedure. MethodsA retrospective review of patients who underwent posterior thoracic and/or lumbar spine surgery between 2010 and 2017 was conducted. Those undergoing surgical treatment of SSI were identified, and patients were divided into two groups - those who were treated with intraoperative vancomycin (treated) and those who were not (untreated). The organism profile for each group was compared. The average LOS, reoperation rate, and number of patients requiring more than 1 antibiotic were calculated for each patient in both groups. ResultsThere were 5,909 procedures performed. One hundred and fifteen SSIs were identified, resulting in a 1.9% infection rate. Prophylactic vancomycin powder was used in the index procedure for 42 of those cases. 23.8% of cultures in the vancomycin group were polymicrobial and 16.7% were gram-negative compared with 9.6% (p=0.039) and 4.1% (p=0.021) in the untreated group, respectively. In the vancomycin-treated group, 26.1% of patients underwent repeat irrigation and debridement compared with 38.4% in the untreated group (p=0.184). The percentage of patients in the treatment and untreated group who required more than 1 antibiotic was 26.0% and 26.1%, respectively (p=0.984). Mean LOS in the treatment group was 8.0 versus 7.9 for the untreated group (p=0.945) ConclusionsIn this series, vancomycin powder was associated with a higher prevalence of gram-negative and polymicrobial organisms in patients that ultimately developed postoperative SSI. However, this did not adversely affect the need for multiple reoperations, antibiotic regimen, or LOS for these patients.

Bacterial Meningitis Caused by Myroides in a Patient With Cerebrospinal Fluid Leakage

To the Editor: Myroides sp are Gram-negative bacteria formerly known as Flavobacterium. This species is often found in environmental sources such as soil and water. It is rarely considered a pathogenic microorganism but rather an opportunistic bacterium that can cause clinical disease in immunocompromised individuals.1 A variety of infections that include cellulitis, bacteremia, endocarditis, and pyelonephritis has been described to date.2 Infection of the central nervous system (CNS) is extremely uncommon and has been reported only once before.3 We describe here the second case of meningitis secondary to Myroides in a patient with maxillary sinus carcinoma. A 47-year-old man presented with fever and headaches over the last 4 days. He also complained of intermittent rhinorrhea for 1 month. He had a history of poorly differentiated squamous cell carcinoma of the left maxillary sinus stage IV. He underwent Cyber knife, radiation therapy, and left maxillectomy that left him with exposed bone in posterior maxillary wall and entire sphenoid cavity. His clinical course was complicated by skull base osteomyelitis, for which he received multiple courses of intravenous antibiotics and suppressive therapy with oral trimethoprim-sulfamethoxazole (for a history of Staphylococcus aureus in bone cultures). On admission, he was febrile and mildly lethargic. Neurologic examination revealed nuchal rigidity, and Kerning and Brudzinsky signs were negative. Laboratory studies showed normal white blood cell count (8 K/μL) and low hemoglobin (8 g/dL). Head computed tomography demonstrated chronic changes consistent with osteomyelitis of the clivus, sphenoid bone, ethmoid, and maxillary sinuses. It also revealed extensive pneumocephalus suspicious for rent in the cribriform plate. Given the high suspicion for meningitis, a lumbar puncture was performed on the day of admission. The cerebrospinal fluid (CSF) analysis showed 89 white blood cells per millimeter3 with lymphocytic predominance (81%), high protein (84 g/dL), and low glucose (45 mg/dL). Gram stain was negative. Blood cultures were also drawn. Analysis of the fluid leaking from nares was positive for β-2 transferrin, which is marker for CSF. These findings were indicative of cerebrospinal leakage that possibly led to meningitis. The patient was on trimethoprim-sulfamethoxazole on admission, which was discontinued, and he was started on acyclovir, cefepime, and vancomycin empirically. On hospital day 3, he was taken to the operating room and underwent placement of pericranial vascularized flap for repair of skull base defect. On hospital day 4, CSF cultures grew Gram-negative rods that were further identified as Myroides sp by matrix-assisted laser desorption ionization time of flight. Susceptibility testing was performed by Vitek 2 (BioMerieux) and interpreted as per Clinical and Laboratory Standards Institute 2014 guidelines. The isolate showed resistance to amikacin, ceftazidime, gentamicin, and tobramycin (Table 1). Blood cultures did not show any growth. Acyclovir, cefepime, and vancomycin were discontinued, and he was started on meropenem. His clinical status improved over the following days. Lumbar puncture was repeated on hospital day 10, and CSF showed normalization of parameters and negative culture. The patient was discharged in stable condition to complete 3 weeks of treatment with meropenem.TABLE 1: Antibiogram of Myroides spMyroides sp is considered an unusual pathogen, but it is being increasingly described in different clinical settings. A recent review by Beharrysingh et al2 identified 48 cases, most of them occurring in immunocompromised hosts. The only case of CNS infection was reported by Macfarlane et al3 and occurred in a 6-week-old infant who developed hydrocephalus and ventriculitis. It remains unknown how this organism gained access to the CNS on that patient; however, the authors hypothesized that this bacterium could have been introduced into the CSF by repeated sampling of the ventricles.3 Our patient presented CSF leakage, which put him at higher risk to develop meningitis.4 Of note, he was on suppressive antibiotics for chronic osteomyelitis, which probably contributed to nasopharynx colonization by uncommon and resistant organisms such as Myroides sp. The treatment of Myroides is challenging because most strains express resistance to a great variety of antibiotics including β-lactams and aminoglycosides.5 Fluoroquinolones seem to be a good therapeutic option. Fortunately, in our case, the susceptibility testing only showed resistance to aminoglycosides and ceftazidime, and treatment with meropenem led to a favorable outcome. Our case illustrates the pathogenic role of Myroides in patients with CSF leakage. We believe that suppressive antibiotics might favor colonization and subsequent infection by this resistant organism. Jose Armando Gonzales Zamora, MDJavier Baez Presser, MD Division of Infectious Diseases Department of Medicine Miller School of Medicine University of Miami Miami, FL [email protected]

Clinical implications of Paracoccus yeeii bacteremia in a patient with decompensated cirrhosis

Infections in patients with cirrhosis are common among those who develop variceal hemorrhage. Prophylactic antimicrobial treatment with third generation cephalosporins is recommended in patients with advanced cirrhosis and gastrointestinal hemorrhage. However no infectious source is identified in up to 50% of patients with cirrhosis and clinical sepsis. We report the first case of Paracoccus yeeii bacteremia in a patient with decompensated cirrhosis who presented with variceal hemorrhage. This rare gram negative organism that occurs naturally in the soil has been difficult to isolate until recent technological advances and may not be susceptible to third generation cephalosporins. Our case reinforces the challenges in isolating rare infections in patients with cirrhosis, the need to consider uncommon organisms in infected but culture negative patients with cirrhosis, and the importance of optimizing antimicrobials to reduce the incidence of drug resistant organisms.

In vitro activity of dalbavancin and five comparator agents against common and uncommon Gram-positive organisms isolated from cancer patients.

Dalbavancin is a long acting, bactericidal lipoglycopeptide. Its in vitro activity was compared with that of vancomycin, daptomycin, linezolid, trimethoprim/sulfamethoxazole (TMP/SMX) and levofloxacin against 241 Gram-positive organisms isolated from cancer patients. The rank order of potency for the glycopeptides based on MIC90 (μg ml(-1)), that is, the concentration of antimicrobial agent required to inhibit 90% of isolates tested was dalbavancin (0.12 μg ml(-1))>daptomycin (1.0 μg ml(-1))>vancomycin (2.0 μg ml(-1)) for coagulase-negative staphylococci and Staphylococcus aureus isolates (including methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains). Dalbavancin had potent activity against staphylococcal isolates with vancomycin MICs⩾1.0 μg ml(-1). TMP/SMX also had potent activity against staphylococci including methicillin-resistant strains, whereas levofloxacin had moderate to poor anti-staphylococcal activity. Dalbavancin also exhibited more potent activity than vancomycin and daptomycin against Bacillus spp., Corynebacterium spp., Micrococcus spp. and various streptococci (including Streptococcus pneumoniae, viridans group streptococci (VGS), beta-hemolytic streptococci and gamma-hemolytic streptococci). MBC determinations showed that dalbavancin had potent bactericidal activity against MRSA with no tolerance being detected. These data suggest that dalbavancin may be considered as an alternative to vancomycin, especially in institutions wherein a substantial proportion of infections are caused by organisms with vancomycin MICs⩾1.0 μg ml(-1).