Microbiology and clinical characteristics of viridans group streptococci in patients with cancer

Abstract

This study assessed the microbiology, clinical syndromes, and outcomes of oncologic patients with viridans group streptococci isolated from blood cultures between January 1st, 2013 and December 31st, 2016 in a referral hospital in Mexico using the Bruker MALDI Biotyper. Antimicrobial sensitivity was determined using BD Phoenix 100 according to CLSI M100 standards. Clinical information was obtained from medical records and descriptive analysis was performed. Forty-three patients were included, 22 females and 21 males, aged 42 ± 17 years. Twenty (46.5%) patients had hematological cancer and 23 (53.5%) a solid malignancy. The viridans group streptococci isolated were Streptococcus mitis, 20 (46.5%); Streptococcus anginosus, 14 (32.6%); Streptococcus sanguinis, 7 (16.3%); and Streptococcus salivarius, 2 (4.7%). The main risk factors were pyrimidine antagonist chemotherapy in 22 (51.2%) and neutropenia in 19 (44.2%) cases, respectively. Central line associated bloodstream infection was diagnosed in 18 (41.9%) cases. Septic shock occurred in 20.9% of patients, with an overall mortality of 18.6%. Only four S. mitis revealed penicillin-resistance. Our results are similar to those of other series, identifying these bacteria as emerging pathogens with significant morbidity and mortality in oncologic patients. The MALDI-TOF system increased the rate of viridans group streptococci isolation in this population.

Isolation and Identification of Optochin-Resistant Viridans Group Streptococci from the Sputum Samples of Adult Patients in Jakarta, Indonesia

“…Meanwhile, the S. anginosus group (38.8%) and S. mitis (22.8%) group were the most common VGS species isolated from bloodstream infection detected by MALDI-TOF MS identification [15]. From oncologic patients, almost half of the VGS isolated from the blood culture was S. mitis isolates (46.5%) followed by S. anginosus (32.6%) and S. sanguinis (16.3%) by MALDI-TOF MS [6]. Oral streptococci isolates were reported as the most detected isolates from bronchoalveolar lavage fluid specimens obtained from pneumonia patients [16].…”

“…e VGS, a group of catalase-negative, Gram-positive Cocci, are a heterogeneous group of bacterium and considered to be normal flora of the oropharyngeal, urogenital, and gastrointestinal microbiota [5]. Classification of VGS has been challenging due to variability and overlap of their microbial characteristics [6]. is bacteria group includes a diverse range of organisms within the genus Streptococcus and can be characterized by green coloration on a blood agar plate [7].…”

Isolation of Streptococcus Thoraltensis in A Case of Necrotizing Fasciitis

“…Therefore, this case report adds more information to the emerging pathogenic nature of the viridans group of streptococci in nonneutropenic patients and patients with normal cardiac valves. 13 Moreover it highlights that the scarcely documented Streptococcus thoraltensis is not to be neglected as a non-human pathogen and implies the need for further studies to be undertaken to confirm its pathogenicity in causing various infections in humans.…”

Viridans Group Streptococcus Meningitis in an Immunocompetent Child: A Case Report

“…Viridans group streptococci (VGS) are commensal organisms that reside in humans, specifically in the oral cavity, skin, respiratory system, and gastrointestinal system [ 1 – 3 ]. Although they have been known as organisms of low virulence and pathogenicity, serious life-threatening infections have been described [ 4 ]. VGS can cause several invasive infections, including native valve endocarditis, dental abscess, septicemia in neutropenic patients, brain abscess, and neonatal sepsis [ 5 – 10 ].…”