Field evaluation of the chessboard modification for serotyping of Streptococcus pneumoniae in a small laboratory in Bangladesh

The chessboard modification of the quellung method for serotyping Streptococcus pneumoniae (Pneumococcus) was introduced in the Gonoshasthaya Vaccine Research Laboratory, a small laboratory in Bangladesh. We applied initial bench-side training and subsequent continuous surveillance and quality assurance a approaches for good laboratory practice. Results obtained a this laboratory on 1,101 consecutive isolates had satisfactory sensitivity (85.1-1.00%) and specificity (97.9-99.9%) for serotyping the 10 most common serogroups/types of pneumococcal when compared with the results obtained in the Finnish reference laboratory for prieurnococcal serotyping at the National Public Health Institute. We conclude that serotyping of pneumococci by the chessboard method can be introduced into a small laboratory by providing basic bacteriologic skills, adequate initial training, and continuous external support.