Viridans Group Streptococci as Emerging Bloodstream Pathogens in Immunocompromised Patients: From Colonization to Invasive Disease

Viridans Group Streptococci (VGS) are increasingly recognized as both a frequent and life-threatening cause of infection in children and adults immunocompromised as a result of chemotherapy or hemopoietic stem cell transplant (HSCT). Because of immune deficiency, clinical presentations are frequently decreased or missing. However, oral infections in neutropenic individuals are a likely fatal source of infectious complications that are underestimated . Despite recent advances in prophylaxis and treatment, viridans group streptococci bloodstream infections (VGS BSI) remain a significant source of morbidity and mortality in patients with severe neutropenia . One or more heart valves develop vegetation after the pathogenic viridans streptococci bacteremia starts. It is challenging to make a diagnosis of viridans streptococci-induced infective endocarditis in individuals who have comorbidities, and it necessitates comparing the results of microbiological (in-vitro growth of viridans streptococci), clinical, and echocardiographic tests (modified Duke criteria). Five species groups comprise the heterogeneous group known as VGS, and each group displays unique vulnerability patterns to penicillin (PEN). PEN resistance is typical in Streptococcus mitis group species. Against VGS, PEN is currently less effective in vitro than third-generation cephalosporins and carbapenems. Therefore, the goal of this review is to update the current understanding of the pathogenic potential of viridans group streptococci in order to open the door for the prevention and treatment of opportunistic VGS infections . Nevertheless, VGS are opportunistic infections that can cause extra-oral illnesses such as pneumonia, bacteremia, and infective endocarditis when conditions are right .

کلیدواژه ها:

Viridans Group Streptococci ، Bloodstream Infection ، Immunocompromised Host ، Neutropenia