The rapid rise in increasingly resistant bacteria has become a major threat to public health. Antimicrobial susceptibility testing (AST) is crucial in guiding appropriate therapeutic decisions and infection prevention practices for patient care. However, conventional culture-based AST methods are time-consuming and labor-intensive. Therefore, rapid AST approaches exist to address the delayed gap in time to actionable results. There are two main types of rapid AST technologies— phenotypic and genotypic approaches. In this review, we provide a summary of all commercially available rapid AST platforms for use in clinical microbiology laboratories. We describe the technologies utilized, performance characteristics, acceptable specimen types, types of resistance detected, turnaround times, limitations, and clinical outcomes driven by these rapid tests. We also discuss crucial factors to consider for the implementation of rapid AST technologies in a clinical laboratory and what the future of rapid AST holds.

Cryptococcal infection can cause significant morbidity and mortality in immunocompromised patients. We present a patient who was diagnosed with cryptococcal meningitis and pulmonary disease in the setting of a history of renal transplantation. The diagnosis was made based on growth of Cryptococcus neoformans in blood cultures and identification of cryptococcal antigen (CrAg) in cerebral spinal fluid (CSF) using a lateral flow assay (LFA). Our case is unique since the initial serum CrAg was falsely negative due to excess cryptococcal antigen preventing the formation of antigen-antibody complexes, referred to as the postzone phenomenon. This phenomenon has been reported on CSF samples but rarely reported on serum samples in patients without an HIV diagnosis.

HHV-8 infection can be asymptomatic in immunocompetent individuals but poses significant risks in immunocompromised patients. As an oncovirus, it can lead to Kaposi sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease (MCD). While the association between HHV-8 and HIV is well-established, other co-infections remain underexplored due to the low incidence of HHV-8 infections. This retrospective, observational study examines twelve individuals infected with HHV-8 over seven years, focusing on patterns of co-infection and the diagnostic need for clinical management. The average age for all patients included in this study was 56 years, and a majority were male (92%). Over a majority presented with fever, night sweats, fatigue, dyspnea, and lymphadenopathy. MCD was the most common diagnosis (42%), followed by KS in the context of MCD (33%). Nearly all patients (92%) were HIV and Epstein-Barr Virus positive, with a total of 43 co-infections identified, including viral (72%), bacterial (16%), parasitic (7%), and fungal (5%) pathogens. Bacterial co-infections were more prevalent in patients diagnosed with KS than in those with MCD (p = 0.02). Given the burden of various co-infections, our findings highlight the need for comprehensive diagnostic testing to guide optimal clinical management and improve patient outcomes.

Patients with Lynch syndrome, most commonly associated with colorectal cancer, have an increased risk of developing other tumors including pancreatic ductal adenocarcinoma and precursor lesions, such as intraductal papillary mucinous neoplasms. Here, we present a case of a man in his early 20s who presented with a retroperitoneal mass involving the head of the pancreas. Following a pancreaticoduodenectomy combined with para-aortic lymphadenectomy, a pathologic diagnosis of colloid carcinoma, also known as mucinous noncystic carcinoma, of the pancreas was reported. Further testing established the diagnosis of Lynch syndrome. This case is unique because colloid carcinoma of the pancreas is rare and has never been reported as an initial presentation of Lynch syndrome.