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.

To inform the efficient allocation of testing resources, we evaluated the characteristics of those tested for COVID-19 to determine predictors of a positive test. Recent travel and exposure to a confirmed case were both highly predictive of positive testing. Symptom-based screening strategies alone may be inadequate to control the ongoing pandemic.

Background Mycobacterium 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. Methods Culture-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. Results Twelve 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. Conclusions M. 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.

We describe our multicenter experience on diagnosis and management of Aerococcus bacteremia including the susceptibility profile of Aerococcus species and a suggested algorithm for clinicians. Methods: Retrospective study of all patients with positive blood cultures for Aerococcus species from January 2005 to July 2020 in our institution with clinical data and susceptibility profile. Data were collected from both electronic health record and clinical microbiology laboratory database. Results: There were 219 unique isolates with only the susceptibility profiles available, while 81 patients had clinical information available. Forty-nine of those cases were deemed as true bloodstream infection and the rest were of unclear clinical significance. Cases of endocarditis (n = 7) were high-grade, monomicrobial bacteremia caused by Aerococcus urinae. Patients with endocarditis were younger (66 vs 80 p < 0.05). The risk for endocarditis was higher if duration of symptoms was longer than 7 days (OR 105, 95% CI: 5À2271), or if there were septic emboli (OR 71, 95% CI: 3-1612). A DENOVA score cutoff of ! 3 was 100% sensitive and 89% specific in detecting endocarditis. The 30-day and 3-month all-cause mortality for bacteremia was 17% and 24%, respectively. Six out of seven patients with endocarditis survived. Conclusions: Antibiotic regimen for aerococcal bloodstream infections and endocarditis should be guided by species identification and antimicrobial susceptibility testing. DENOVA scoring system's performance in this study is more congruent to other studies. Hence, it can be used as an adjunctive tool in assessing the need for echocardiogram to rule out endocarditis. In our experience, two and four weeks of treatment for bloodstream infections and endocarditis, respectively, had good outcomes.