Background Lactobacillus are low virulence commensal organisms which are commonly found in the human oral cavity, gastrointestinal and genitourinary tracts. Although Lactobacillus bacteremia (LB) is rare, evidence aggregating from case reports has implicated LB in several medical conditions. As such, there is reason to suggest that the presence of these organisms in blood cultures may not be due to spurious contamination, but rather, indicative of clinically meaningful events capable of inducing serious illnesses. The purpose of this study is to characterize the risk factors, clinical significance and outcomes of patients with LB. Methods We retrospectively reviewed the medical records of patients presenting to a large urban teaching hospital between January 1, 2017 and December 31, 2018, who were found to have LB. Identified individuals were grouped into two mutually exclusive case categories: true LB cases or non-true cases (i.e., contamination). Individuals with ≥1 positive blood and were started on appropriate antibiotics were considered true cases. Those with positive cultures not started on appropriate antibiotics were considered contaminants. Results A total of 14 patients were identified during our study period, with majority considered true LB cases [71.4%; n = 10]. These 14 individuals were mostly males [64.2%; n = 9] and reported no use of Lactobacilli probiotics [78.6%; n = 11] or antacids [57.1%; n = 8]. On average, true LB cases were older (mean [SD]): 80.1 [±10.9]vs. 54.0 [±19.1] years) and required longer hospitalization (38.5 [(±27.6] vs. 8.0 [(±6.2] days) compared to non-LB cases, respectively. Among the 10 true LB cases, the suspected source of infection included gastrointestinal system [50%; n = 5], infective endocarditis [10%; n = 1], genitourinary system [10%; n = 1]; and could not be determined in 3 [30%] cases. Concurrent infection with candida and gastrointestinal microbes were noted in four (40%) of the true LB cases, respectively. Overall, five deaths were observed, with 4 [80%] occurring in true LB cases and one in a non-LB case. Conclusion LB should not be dismissed as contaminants particularly in at-risk patients for LB, such as the elderly or immunocompromised individuals. Disclosures All Authors: No reported disclosures

Objective: Clostridioides difficile infection (CDI) is among the most common cause of healthcare-associated infections. Persons requiring maintenance hemodialysis (MHD) are at increased risk of CDI and associated mortality compared to persons not requiring MHD. Given the clinical impact of CDI among persons requiring MHD, we aimed to quantify the burden of CDI and trends over time in this patient population. Study design: A systematic review and meta-analysis of studies reporting rates of CDI among persons requiring MHD in MEDLINE, Embase, Web of Science Core Collection, CINAHL, and Cochrane Central Register of Controlled Trials were performed. Searches were conducted on May 17, 2021, and March 4, 2022. Results: In total, 2,408 titles and abstracts were identified; 240 underwent full text review. Among them, 15 studies provided data on rates of CDI among persons requiring MHD, and 8 of these also provided rates among persons not requiring MHD. The pooled prevalence of CDI among persons requiring MHD was 19.14%, compared to 5.16% among persons not requiring MHD (odds ratio [OR], 4.35; 95% confidence interval [CI], 2.07–9.16; P = .47). The linear increase in CDI over time was significant, increasing an average of 31.97% annually between 1993 and 2017 (OR, 1.32; 95% CI, 1.1–1.58; P < .01). The linear annual increase was similar among persons requiring and not requiring MHD (OR, 1.28; 95% CI, 1.13–1.45; P = .11). Conclusions: Persons requiring MHD have a 4-fold higher risk of CDI compared to persons not requiring MHD, and rates of CDI are increasing over time in both groups.

A HIV-negative, newly diagnosed patient with rheumatoid arthritis (RA) was found to have pneumocystis jiroveci pneumonia. The infection was treated with three weeks of atovaquone and corticosteroids. Clinicians should be aware of pneumocystis pneumonia as an infection in RA patients not receiving treatment.

Listeria endocarditis is a rare, but serious disease with high mortality rate. Currently, little is known regarding the optimal treatment modality of Listeria endocarditis in affected individuals. Here, we present the case of a 66-year-old female with history of mitral and aortic replacement with bioprosthetic valve, and hospital course complicated by Listeria monocytogenes infective endocarditis with atrial-ventricular (AV) block. Listeria monocytogenes infection was eradicated by a 6-week antimicrobials course involving ampicillin and gentamicin, culminating in the resolution of AV block. On further investigation, the patient admitted to frequent consumption of salami and provolone cold-cut sandwiches, which based on previous evidence in literature is hypothesized to be the source of infection. Our findings suggest the development of perivalvular abscesses as the cause of the AV block. To our knowledge, this is the first reported case in literature where AV block secondary to listeriosis resolved with treatment solely by antimicrobials. While further research and larger studies are needed to extend our findings, patients with AV block secondary to listeriosis may benefit from optimized management with antimicrobials.