Fusobacterium bloodstream infections: A literature review and hospital-based case series.

BACKGROUND: Infections with Fusobacterium, an anaerobic bacterium, have various clinical presentations, including bacteremia and Lemierre syndrome. Here, we report a case series of Fusobacterium bacteremia (FBB) from the largest academic center in Riyadh, Saudi Arabia, and provide a review of cases in the available literature. METHOD: Records were retrospectively reviewed for all patients with at least one blood culture positive for Fusobacterium spp. admitted at King Khalid University Hospital, Riyadh, Saudi Arabia, between May 2015 to April 2019. LITERATURE REVIEW: We conducted a MeSH Search on MedLine using the following terms: ("Bacteremia"[Mesh]) AND "Fusobacterium"[Mesh] for studies conducted from January 1, 1990, until March 30, 2019, excluding articles that lacked adequate clinical or microbiological details for individuals patients. Odds ratios and results of Chi-Square testing obtained in SPSS (Version 23.0, SPSS, Inc., Chicago, IL, USA) were considered statistically significant at p-values < 0.05. RESULTS: Seven cases from our center and 205 cases from the literature were reviewed in this first reported case series for the region. Our patient series was similar to previous ones in terms of median age (45 vs. 45.5 years) and male predominance (85% vs. 65.9%). The species of Fusobacterium cultured from our cases were F. nucleatum (4 cases), F. varium (1 case), F. mortiferum (1 case), and one that could not be identified to the species level (1 case). We also report one case of FBB with renal vein thrombosis resembling that of atypical Lemierre syndrome. Analysis of literature cases revealed that bacteremia caused by the species most commonly associated with FBB, F. necrophorum, tended to be present in patients less than 40 years of age and be associated with head and neck infections and other complications, whereas F. nucleatum tended to affect people more than 40 years of age and be associated with mortality. CONCLUSION: Although FBB is rarely reported in the literature, this case series and review of the literature suggests it is associated with morbidity and mortality. The type and duration of therapy used in these cases are underreported. Further research is needed to determine the most appropriate screening approach for FBB-associated complications and explore the relationship between FBB and specific malignancies, as well as optimal treatment type and duration.

Clinical characteristics and imaging features of patients with nontuberculous mycobacteria in a tertiary care center.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are ubiquitous organisms that occasionally causes invasive diseases in humans, but they are under-reported in Saudi Arabia. We aimed to describe NTM infections and apply the American Thoracic Society/Infectious Diseases Society of America ATS/IDSA criteria. METHOD: Positive laboratory reports for NTM between January 2006 and December 2017 were retrospectively reviewed, and then classified into respiratory and non-respiratory specimens. ATS/IDSA criteria were applied to all respiratory specimens. Host status, clinical presentation, species identification, imaging, treatment, and outcome data were collected using a standardized form and analyzed. Cases with duplication or incomplete data were excluded. RESULTS: 183 unique patients with positive NTM culture were included. Median age was 52 years and males represented 59%. Majority of cases were in the respiratory specimens group (n = 146), of which only 15 cases have met the ATS/IDSA criteria. Overall, cases were primarily known to have non-immunocompromising condition but 27% had either an active malignancy (n = 35), HIV (n = 13), or primary immunodeficiency (n = 8). 68.3% of cases presented with respiratory symptoms with or without fever. Among the identified NTM species (51.9%), slowly growing NTM were predominant. Anti-NTM therapy was provided in only 22.4% of this cohort. Death was documented only in 5 cases; all were in the respiratory group and were not treated. CONCLUSION: Though uncommon to isolate, only one in every ten respiratory NTM isolates was found potentially true pathogen in a single center in Saudi Arabia. Future studies on NTM prevalence in Saudi Arabia are recommended.