Citations

Abstract Background Infective endocarditis (IE) is the most feared complication of Staphylococcus aureus bacteremia (SAB). Transesophageal echocardiogram (TEE) is generally recommended for all patients with SAB; however, supporting data for this are limited. We previously developed a scoring system, “PREDICT,” that quantifies the risk of IE and identifies patients who would most benefit most from undergoing TEE. The current prospective investigation aims to validate this score. Methods We prospectively screened all consecutive adults (≥18 years) hospitalized with SAB at 3 Mayo Clinic sites between January 2015 and March 2017. Results Of 220 patients screened, 199 with SAB met study criteria and were included in the investigation. Of them, 23 (11.6%) patients were diagnosed with definite IE within 12 weeks of initial presentation based on modified Duke’s criteria. Using the previously derived PREDICT model, the day 1 score of ≥4 had a sensitivity of 30.4% and a specificity of 93.8%, whereas a day 5 score of ≤2 had a sensitivity and negative-predictive value of 100%. Additional factors including surgery or invasive procedure in the past 30 days, prosthetic heart valve, and higher number of positive blood culture bottles in the first set of cultures were associated with increased risk of IE independent of the day 5 risk score. Conclusions We validated the previously developed PREDICT scoring tools for stratifying risk of IE, and the need for undergoing a TEE, among cases of SAB. We also identified other factors with predictive potential, although larger prospective studies are needed to further evaluate possible enhancements to the current scoring system.

Abstract Background Stenotrophomonas maltophilia is a gram-negative, opportunistic infection that is usually hospital-acquired and associated with high morbidity and mortality. The reported increase in S. maltophilia infections is presumed to be due to an increase in the population at risk. Methods We retrospectively reviewed 10-year data for S. maltophilia bacteremia in hospitalized adults at our institution to determine the population at risk, sources of infection, common complications, antimicrobial susceptibility profiles, and clinical outcome trends over the past decade. Results Among the 98 patients analyzed, the most common source of infection was catheter-related (62, 63.3%). Most isolates (61, 65%) were resistant to ceftazidime; fewer were resistant to trimethoprim-sulfamethoxazole (TMP-SMX; 2, 2.1%) and levofloxacin (22, 23.4%). All-cause in-hospital mortality was 29.6% (29 patients). The highest mortality, 53.8%, was observed in pulmonary sources of bacteremia. Conclusions Although TMP-SMX continues to have reliable activity in our cohort, we noted resistance to TMP-SMX in patients with recent TMP-SMX exposure, including a case with developing resistance to TMP-SMX while on therapy.

AbstractBackgroundMycobacterium marinum is a common but underreported mycobacterial infection. We conducted a large retrospective study to determine risk factors and describe the therapeutic interventions and outcomes in patients with uncomplicated and complicated M. marinum infection.MethodsCulture-confirmed M. marinum infection cases were identified from the Mayo Clinic Clinical Mycology Laboratory from January 1998 to December 2018. Complicated M. marinum infection was defined as the presence of tenosynovitis, septic arthritis, or osteomyelitis. Differences in complicated vs uncomplicated M. marinum infections were analyzed using statistical comparisons.ResultsTwelve cases had a complicated M. marinum infection. Patients with a complicated infection were older (64.3 ± 11.1 vs 55.8 ± 14.5; P = .03), had longer duration of symptoms (5 vs 3 months; P = .011), and had more surgical debridements (1 vs 0; P < .001). Length of treatment and number of drugs used were not statistically significant. Complicated M. marinum cases received more medications (2 vs 1; P = .263) and were treated longer (5.7 vs 3.5 months; P = .067). Antibiotic susceptibilities were performed in 59% of the patients. All isolates were susceptible to clarithromycin. From the tetracyclines, doxycycline had a better susceptibility pattern.ConclusionsM. marinum infection is an important cause of skin and soft tissue infection. Poor water exposure documentation, unusual clinical presentation, and empiric antibiotic treatment before definitive M. marinum diagnosis often contribute to a delayed diagnosis. Complicated M. marinum cases had longer duration of symptoms and more surgical debridements. No difference in the number of drugs used or clinical outcome was observed.

Nocardia species are found worldwide and are opportunistic pathogens of both immunocompromised and immunocompetent hosts. Recent updates to the taxonomy of this genus have indicated that there are more than 90 recognized species of Nocardia with 54 species reported to be clinically relevant.

Abstract Background Q fever is a zoonotic disease caused by Coxiella burnetii. Primary infection can progress to persistent infection irrespective of initial symptomatology. Our aim is to describe the clinical features, treatment, risk of progression, use of prophylaxis, and outcomes of Coxiella burnetii infection at our institution. Methods We did a retrospective review of all adult patients with positive Coxiella burnetii serology at Mayo Clinic, Rochester from 1st January 2012 to 31st December 2018. Centers for Disease Control and Prevention (CDC) case definition and classification were used to group the patients into confirmed and probable acute Q fever, and confirmed and probable chronic/persistent Q fever. Data on demographics, clinical presentation, comorbid conditions, exposure history, risk factors associated with progression, serology, treatment and outcomes were collected. Results We found 266 patients with positive titres of Coxiella IgG or IgM greater than 1:16, of which 49 patients met the CDC case definition for Q fever. Median age at presentation was 62 years. 45/49 (91. 8%) were men, while 4/49 (8%) were women. 20/49 (40. 8%) patients presented with acute Q fever of which 5 (25%) patients progressed to persistent infection. 29/49 (59%) patients presented with persistent Q fever of which 4 patients could recall symptoms suggestive of acute Q fever. The most common presentation of acute Q fever was acute febrile illness (65%). Endocarditis (11/29) was the most common presentation of chronic/persistent Q fever. Of the 5 patients with acute Q fever that progressed to persistent infection, 3/5(60%) progressed despite being on doxycycline and hydroxychloroquine. 8/29 patients with persistent Q fever had serological resolution at last follow-up. 2/4(50%) deaths were attributable to Q fever. Conclusion Minority of the patients tested met the case definition. 25% of patients with acute disease progressed to chronic Q fever out of which 60%(3/5) progressed despite prophylaxis. Endocarditis and vascular infections were the most common chronic cases. Interestingly we found 4 cases of MPGN in association with Q fever. Prosthetic valves are the most important risk factors for progression (P = 0.02). Serological cure often lags behind clinical cure (27% vs. 68% in persistent infection)(Table 4). Disclosures All authors: No reported disclosures.

Abstract Background Ocular syphilis is an infrequent presentation of Treponema pallidum infection. It is often seen in association with neurosyphilis but can occur in isolation as well. Here we describe a case series of 10 patients with ocular syphilis seen at our institution. Methods Patients with a diagnosis of ocular syphilis at the three sites of Mayo Clinic were identified from June 2006 to February 2019. Patient’s baseline characteristics, clinical presentation, diagnostic testing, and treatment were abstracted from Electronic Medical Records. Results We identified 10 patients (17 eyes) during the study period, half being diagnosed in the last 5 years. The median age was 51 years (IQR 21–66), and the majority were males (7/10). Characteristics of the patients are outlined in Table 1. Common presenting symptoms included vision loss (8/10), photophobia (4/10), and irritation (5/10). Seven of 10 patients had bilateral involvement. Of the 17 eyes, 59% had pan-uveitis and 82% had disc edema (Table 2). Rapid Plasma Reagin (RPR) was positive in 9 patients and median serum RPR was 1:128 (IQR 1:2-1:1024). One patient was diagnosed with a positive TP-PA, and characteristic ocular findings. One patients had positive 16S Ribosomal RNA Gene PCR/Sanger Sequencing on vitreous humor specimen for Treponema species. The majority of patients had isolated ocular symptoms at presentation; two patients also had an associated skin rash. All patients underwent a lumbar puncture (LP). Half had pleocytosis (TNC > 5) and elevated protein elevated (mean 63.6 mg/dL), although not significantly high. 3/10 patients had VDRL positive in the CSF. Protein levels were much higher in those with positive VDRL. Each patient was treated with intravenous (IV) penicillin for at least 2 weeks. Nine patients received ocular steroids as well. At last available follow-up, 8 had complete and 1 had partial resolution. One had worsened eye findings with eventual scarring. Conclusion Our findings are congruent with increasing incidence of ocular syphilis nationwide. Bilateral eye involvement and pan-uveitis were the most common ocular findings. Although only 3 patients had a positive VDRL in the CSF, pleocytosis and elevated protein were found in a large number of patients. Majority of the patients had clinical resolution with appropriate treatment. Disclosures All authors: No reported disclosures.

Abstract Background Polymerase chain reaction (PCR)/sequencing targeting the 16S ribosomal RNA (rRNA) gene to detect bacteria in normally sterile tissues and fluids has become increasingly popular in clinical medicine. This culture-independent technique can detect bacteria that are nonviable or difficult to cultivate using conventional methods. The clinical value of this type of testing is not well defined. We aimed to assess the diagnostic value of 16S rRNA PCR/Sanger sequencing as a clinical diagnostic assay at Mayo Clinic. Methods This is an interim analysis of the first 173 of 478 patients who had 16S rRNA PCR/Sanger sequencing done on sterile tissues or fluids at our institution from April, 2017 to November, 2018 as part of routine clinical practice. Medical records are being retrospectively reviewed, with results compared with those of culture. Results We reviewed 207 specimens from 173 patients (musculoskeletal 79%, cardiovascular 7%, central nervous system 4%, other 9%) that underwent 16S rRNA PCR/Sanger sequencing by clinical request (Table 1). In 90% of these specimens, the test was pre-planned rather than added-on. Nine specimens were excluded from analysis, as cultures were not performed. Overall concordance of culture with PCR/sequencing was 81% (160/197; P < 0.0001). Of 44 culture-positive specimens, PCR detected the same bacterium in 21 (48%) (Table 2). 45% (20/44) of those with positive cultures and 46% of those with positive PCR/sequencing results had received prior antimicrobial therapy (Table 3). PCR was negative in 139/144 specimens that were culture-negative (97%). PCR/sequencing was helpful in detecting a putative bacterial pathogen in 4 patients with negative cultures (Table 4). Conclusion Overall, 16S rRNA PCR/Sanger sequencing improved diagnostic yield compared with culture in a minority of cases. The described assay is limited by its inability to detect polymicrobial infections, a technical limitation that could possibly be addressed using massive parallel sequencing. Careful selection of cases and a save and add-on approach may be more cost-effective than upfront testing, although this was requested in a minority of cases. Disclosures Robin Patel, MD, ASM and IDSA: Other Financial or Material Support, Travel reimbursement, editor’s stipends; CD Diagnostics, Merck, Hutchison Biofilm Medical Solutions, Accelerate Diagnostics, ContraFect, TenNor Therapeutics Limited, Shionogi: Grant/Research Support; Curetis, Specific Technologies, NextGen Diagnostics, PathoQuest, Qvella: Consultant; NBME, Up-to-Date, the Infectious Diseases Board Review Course: Honorarium recipient, Other Financial or Material Support; Patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent on an anti-biofilm substance issued: Other Financial or Material Support, Patents.

Abstract Background Norovirus and serotypes (40/41) of adenoviruses are the leading cause of viral acute gastroenteritis in adults. The lack of therapeutic options can be devastating especially in the immunocompromised population. Nitazoxanide (NTZ), first designed as an antifolate anti-parasitic agent, is also known to have a broad-spectrum antiviral activity. Efficacy of NTZ in decreasing duration of symptomatic diarrhea in adults was first reported in a placebo controlled trial in 2006. Subsequent reports showed some promise as a possible therapeutic agent for viral gastroenteritis in the immunocompromised hosts. Methods Utilizing the inpatient pharmacy database we identified patients, who received NTZ for documented viral gastroenteritis, from January 1, 2008 to April 15, 2019. Chart review of cases was done to determine demographics, comorbidities, length of stay (LOS) in hospital, LOS in intensive care unit (ICU), duration of therapy, improvement in symptoms, and mortality. Results We identified 48 unique adult patients who were administered NTZ in the period under review. Of these 10 were prescribed NTZ specifically for viral gastroenteritis. 40% of the patients were females. The median age was 59 years (Interquartile Range [IR]: 47.75–69.25). Median LOS in hospital was 9.5 days (IR: 6.75–41.75). None of the patients required admission to the ICU. 4/10 patients had an active concomitant malignancy, of these 3 were receiving ongoing chemotherapy. 9/10 patients were recipients of stem cell (2) or solid-organ transplants (7). 7/10 patients were also on some form of immunosuppressive medications. Most common virus isolated was Norovirus (7/10). All patients received a standard dose of 500mg twice daily NTZ. The median duration of therapy was 7 days (range: 3–21). 6/10 patients had documented improvement in diarrhea at the end of treatment. 1/10 patients died within 30 days of diagnosis from causes unrelated to diarrheal illness (Table 1). Conclusion Our limited data set presents interesting insights into treatment of viral gastroenteritis in immunocompromised hosts, in particular transplant recipients. All of the cases identified were treated in second half of study period after January 1, 2015, signaling an increasing interest in this therapy, especially in cases with prolonged symptoms or viral shedding. Our observations indicate a need for larger studies into this application of NTZ in adult immunocompromised hosts. Disclosures All authors: No reported disclosures.

Abstract Background Mycobacterium marinum is a slow-growing, non-tuberculous mycobacterium responsible for skin and soft-tissue infections (SSTIs), tenosynovitis, and osteomyelitis (OM). We conducted a retrospective study describing the risk, clinical course, and outcome of M. marinum infection. Methods Adult patients with culture-confirmed M. marinum infections were identified from the mycology laboratory at Mayo Clinic, Rochester from January 1998 to December 2018. M. marinum infection was defined as uncomplicated (limited to SST) and complicated (tenosynovitis, OM, or disseminated). Results Forty-six cases of culture-confirmed infection with M. marinum were included (Table 1). Only 16 cases (35%) reported a water exposure and 22 (48%) involved finger and/or hand trauma. The median time to diagnosis was 3.6 months. Most patients (76%) presented with uncomplicated M. marinum infection with skin lesions mainly localized in the upper limb (Table 2). QuantiFERON and PPD were positive in 4 (8%) and 2 (4%) cases, respectively. Granulomatous inflammation and positive special stains were noted in 34 (74%) and 11 (24%) cases, respectively. Cases with complicated M. marinum infection had a longer duration of symptoms and length of treatment (P < 0.05) (Table 3). Prior to diagnosis, 63% of patients received at least one antibiotic for bacterial SSTIs. More than 50% of the patients diagnosed with M. marinum received a one drug regimen and 8% did not initiate therapy. Median treatment duration was 4.4 months. Twenty-six cases (56%) had susceptibilities performed and treatment modifications were made in 10 cases (38%). From the patients that started therapy, 73% completed therapy and 33% were lost to follow up. Cured was achieved in 87% of cases that completed therapy, 2 cases (6%) had a recurrence, and only one patient with active malignancy had a positive blood culture and died. Twelve (44%) and 10 cases (37%) were cured with one and two-drug regimens, respectively. Conclusion Most patients with M. marinum infection present as an uncomplicated infection in the upper limb. Classical exposure was only suspected in a third of the cases. Patients with complicated M. marinum infection had a prolonged duration of symptoms and lengthy treatment. Most patients were successfully treated with a one and two-drug regimen. Disclosures All authors: No reported disclosures.