Streptococcus pneumoniae: distribution of serotypes and antimicrobial susceptibility in patients with cancer

Abstract

Objective. To describe the distribution of pneumococ­cal serotypes causing infectious diseases in patients with hematological malignancies and solid tumors and their antimicrobial susceptibility before and after introduction of pneumococcal conjugate vaccine (PCV7) in Mexico. Mate­rials and methods. Consecutive pneumococcal isolates from hospitalized patients from the SIREVA-network were serotyped using the Quellung reaction and antimicrobial susceptibility was performed using the broth microdilution method. Results. A total of 175 pneumococcal isolates were recovered, 105 from patients with hematological malignan­cies and 70 with solid tumors. Serotypes 19A (22.7%), 19F (20.4%), and 35B (17.7%) were the most frequent isolates in the first group and serotypes 3 (27.2%) and 19A (28.6%) in the second group. No decreased susceptibility to beta-lactams or TMP/SMX was observed after introduction of PCV7. Conclusions. An increase in non-vaccine types is observed without significate changes in antimicrobial susceptibility after introduction of PCV7.

Keywords

• Streptococcus pneumoniae
• cancer
• vaccines
• antiinfective agents