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. In this paper, we report the species distribution, specimen source distribution, and antimicrobial susceptibility profiles of 2,091 clinical isolates recovered for the years 2011 to 2017 using the updated taxonomy. The most commonly isolated species included Nocardia nova complex, Nocardia cyriacigeorgica, and Nocardia farcinica complex, with an additional 25 species or species complexes recovered from clinical specimens. The antimicrobial susceptibility profile was highly variable between the species, but in general, amikacin, linezolid, and trimethoprim-sulfamethoxazole demonstrated good in vitro activity against most species.

Background Conventional blood cultures were compared to plasma cell-free DNA–based 16S ribosomal RNA (rRNA) gene polymerase chain reaction (PCR)/next-generation sequencing (NGS) for detection and identification of potential pathogens in patients with sepsis. Methods Plasma was prospectively collected from 60 adult patients with sepsis presenting to the Mayo Clinic (Minnesota) Emergency Department from March through August 2019. Results of routine clinical blood cultures were compared to those of 16S rRNA gene NGS. Results Nineteen (32%) subjects had positive blood cultures, of which 13 yielded gram-negative bacilli, 5 gram-positive cocci, and 1 both gram-negative bacilli and gram-positive cocci. 16S rRNA gene NGS findings were concordant in 11. For the remaining 8, 16S rRNA gene NGS results yielded discordant detections (n = 5) or were negative (n = 3). Interestingly, Clostridium species were additionally detected by 16S rRNA gene NGS in 3 of the 6 subjects with gastrointestinal sources of gram-negative bacteremia and none of the 3 subjects with urinary sources of gram-negative bacteremia. In the 41 remaining subjects, 16S rRNA gene NGS detected at least 1 potentially pathogenic organism in 17. In 15, the detected microorganism clinically correlated with the patient’s syndrome. In 17 subjects with a clinically defined infectious syndrome, neither test was positive; in the remaining 7 subjects, a noninfectious cause of clinical presentation was identified. Conclusions 16S rRNA gene NGS may be useful for detecting bacteria in plasma of septic patients. In some cases of gram-negative sepsis, it may be possible to pinpoint a gastrointestinal or urinary source of sepsis based on the profile of bacteria detected in plasma.

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.

Human herpesviruses 6 (HHV-6) A and B cause encephalitis in patients with hematologic malignancies, especially those undergoing allogeneic hematopoietic stem cell transplantation. In this cohort of 10 patients, persistent neurologic deficits associated with moderate to severe bilateral hippocampal atrophy were characteristic long-term findings, despite prolonged antiviral treatment.

Babesiosis is an emerging health risk, and clinicians need to be aware of its different clinical manifestations. In our cohort of 38 patients, almost half did not recall a tick bite, and diagnosis was delayed due to the nonspecific nature of symptoms. Sixty-eight percent of patients required hospitalization, with 21% requiring intensive care unit stay. Coinfection with Lyme, anaplasma, or both Lyme and anaplasma was seen in 24%, 5%, and 8% of the patients, respectively. None of the patients in our cohort died from their disease.

T he clinical efficacy of cidofovir for the treatment of adenovirus-related disease is limited, and toxicity is a major concern. Furthermore, pharmacokinetic limitations such as poor bioavailability lead to an insufficient fidelity between the prescribed dose and the pharmacodynamics effects. Nitazoxanide, an agent with broad antiviral activity and less toxicity, may be a consideration for non-life-threatening adenovirus-related enteritis/colitis. Moreover, different from the virus-targeted mechanisms of other therapies, the mechanism of nitazoxanide and tizoxanide, the active metabolite, involves the disruption of host-regulated pathways involved in viral replication (1-3). This mechanistic nuance limits the viral resistance for nitazoxanide. We present a case of an immunocompromised adult with adenovirus-related diarrhea and low-level viremia who was successfully treated with nitazoxanide.A 61-year-old patient was hospitalized at our institution with a 2-week history of nonbloody diarrhea. The patient's history included relapsed multiple myeloma diagnosed in 2015, after autologous hematopoietic stem cell transplant, and treatment with daratumumab, pomalidomide, and dexamethasone, with the latest treatment 1 month prior to the index admission. All of the other systems reviewed were negative. The patient reported there had been no recent travel, contact with sick individuals, or exposure to contaminated water/food. The physical exam revealed an increased heart rate of 101 beats/min, normal systolic blood pressure, and a temperature of 37.7°C. The patient appeared dehydrated and lethargic, and an abdominal exam revealed hyperactive bowel sounds with no pain, guarding, or hepatosplenomegaly. A laboratory evaluation revealed a normal white blood cell count of 7.5 ϫ 10 9 cells/liter, with no abnormalities on a differential cell count. However, both CD3 (547 cells/l) and CD4 (180 cells/l) cell counts were low. A metabolic profile indicated acute kidney injury, with a serum creatinine (Cr) level of 1.9 mg/dl, up from a baseline Cr of 1.5 mg/dl. Other electrolyte derangements included hypokalemia (2.7 mmol/liter) and mild hypomagnesemia (1.6 mg/dl). The liver enzyme levels were unremarkable, and a gastrointestinal pathogen multiplex PCR panel was negative for Clostridium difficile toxin B but positive for adenovirus F40/41. This prompted an evaluation of adenovirus in plasma samples via quantitative real-time PCR, which returned a positive result with 3,671 copies/ml (reference, Ͻ500 copies/ml). An X ray of the abdomen showed no signs of obstruction or free air. The patient underwent flex sigmoidoscopy, where a 2-cm sessile polyp in the descending colon was noted. Histopathology demonstrated a normal colonic mucosa, no microscopic colitis, and negative results for cytomegalovirus (CMV) immunostaining.The case was classified as adenovirus viremia with disease symptoms of gastrointestinal involvement. In consideration of the hemodynamic stability, the low risk for disseminated disease, and the impaired renal function, an ...

Objective To analyze and interpret clinical microbiology data for specimens tested with the fluorochrome stain (AFB stain), mycobacterial culture and a laboratory-developed Mycobacterium tuberculosis (MTB) PCR in order to understand the performance of each test and to demonstrate the utility of MTB PCR to assist with decisions regarding discontinuation of airborne isolation. Methods Retrospective cohort analysis of 2798 respiratory specimens from 2006 patients in the period between November 1st, 2011 and January 1st, 2018. Results 53.7% were males, median age was 61 years, and 43 patients were HIV positive. Results demonstrated positive mycobacterial cultures for MTB in 52 specimens (1.9%) and for nontuberculous mycobacteria (NTM) or aerobic actinomycetes (eg., Nocardia spp.) in 435 specimens (16%). Using mycobacterial culture as the gold standard, AFB smear had a sensitivity of 48.1% while MTB PCR had a sensitivity of 96.0% in AFB smear positive specimens and an overall sensitivity of 57.7% with PPV of 94% and a NPV of 99%. Conclusions The combination of a positive AFB smear with a negative MTB PCR offers a rapid result to rule out active pulmonary MTB in a low prevalence setting. In this study, that combination reliably excluded active tuberculosis (NPV of 99.2%). The combination of a positive AFB smear with a negative MTB PCR indicated pulmonary NTM infection with the results available within 1 day. There was little benefit to pursuing collection and testing of more than 2 respiratory specimens in a low prevalence setting for both long term diagnostic or rapid isolation discontinuation purposes.

BackgroundNutritionally variant streptococci (NVS) are an infrequent cause of infective endocarditis (IE) and management recommendations are based on weak levels of evidence largely derived from case reports, small case series, and animal models of experimental endocarditis. Moreover, taxonomic changes have led to some confusion in designation of these organisms.MethodsWe retrospectively collected and analyzed data from 33 patients with NVS IE from 1970 to 2017. Only patients who met modified Duke Criteria for IE were included.ResultsMean patient age was 55 years and 61% were males. The most common comorbidities included diabetes mellitus (12%), malignancy (3%), heart failure (16%), coronary artery disease (25%), and chronic liver disease (9%). Predisposing valve abnormalities included rheumatic heart disease (11%), bicuspid aortic valve (22%), transplant valvulopathy (3%), mitral valve prolapse (3%), and congenital heart disease (11%). Cultures were reported as NVS (70%), Granulicatella species (18%) and Abiotrophia species (12%). Echocardiogram findings included vegetations (67%), new regurgitation (55%), perivalvular abscess (3%), mitral valve prolapse (3%), and ruptured mitral valve chordae (3%). Both prosthetic (26%) and native valve IE (74%) was seen, and the valves involved were aortic (37%), mitral (50%) and both aortic and mitral (13%). Complications were seen in 27% of patients, including heart failure (17%), splenic infarct (11%), stroke (8%), mycotic aneurysm (3%), and glomerulonephritis (2%). In vitro susceptibility to penicillin, ceftriaxone, and vancomycin was 88%, 80%, and 100%, respectively. The majority (77%) of patients were treated with a combination of β-lactam and aminoglycoside. Median duration of treatment was 33 days. Surgery was performed in 50% of patients with no significant difference in survival between those who were treated with combined medical/surgical treatment and those treated with medical therapy alone. Overall survival at 1, 4, and 10 years was 93%, 83%, and 66%, respectively.ConclusionIE due to NVS is a rare entity and is associated with a high rate of serious complications and may involve multiple valves. Long-term, two-thirds of the patients survived more than 10 years.Disclosures All authors: No reported disclosures.