International Circumpolar Surveillance System for Invasive Pneumococcal Disease, 1999–2005

Disease rates are high among indigenous persons in Arctic countries, and PCV7 has resulted in decreased rates in North American children

Survival of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis Frozen in Skim Milk- Tryptone-Glucose-Glycerol Medium

In STGG (skim milk, tryptone, glucose, glycerol) medium at −80°C, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis isolates survived for at least 3 years, and the same species have survived in nasopharyngeal swabs for at least 1.5 years. At −20°C, S. pneumoniae and M. catarrhalis survived for 1.5 years, but H. influenzae survived for only 2 months

Using Multilocus Sequence Data To Define the Pneumococcus

We investigated the genetic relationships between serotypeable pneumococci and nonserotypeable presumptive pneumococci using multilocus sequence typing (MLST) and partial sequencing of the pneumolysin gene (ply). Among 121 nonserotypeable presumptive pneumococci from Finland, we identified isolates of three classes: those with sequence types (STs) identical to those of serotypeable pneumococci, suggesting authentic pneumococci in which capsular expression had been downregulated or lost; isolates that clustered among serotypeable pneumococci on a tree based on the concatenated sequences of the MLST loci but which had STs that differed from those of serotypeable pneumococci in the MLST database; and a more diverse collection of isolates that did not cluster with serotypeable pneumococci. The latter isolates typically had sequences at all seven MLST loci that were 5 to 10% divergent from those of authentic pneumococci and also had distinct and divergent ply alleles. These isolates are proposed to be distinct from pneumococci but cannot be resolved from them by optochin susceptibility, bile solubility, or the presence of the ply gene. Complete resolution of pneumococci from the related but distinct population is problematic, as recombination between them was evident, and a few isolates of each population possessed alleles at one or occasionally more MLST loci from the other population. However, a tree based on the concatenated sequences of the MLST loci in most cases unambiguously distinguished whether a nonserotypeable isolate was or was not a pneumococcus, and the sequence of the ply gene fragment was found to be useful to resolve difficult cases

Ability of Pneumococcal Serotypes and Clones To Cause Acute Otitis Media: Implications for the Prevention of Otitis Media by Conjugate Vaccines

The relative abilities of pneumococcal serotypes and strains (clones) to cause acute otitis media (AOM) were investigated by comparing the serotypes and genotypes of pneumococci recovered from cases of AOM (n = 149) in children <2 years of age with those from nasopharyngeal carriage (n = 288) in age-matched controls from the same region. The odds ratio (OR) for association of pooled vaccine serotypes with AOM was found to be slightly elevated over unity, although this was not significantly different from that of pooled nonvaccine or vaccine-related serotypes. Comparing individual serotypes, 19F and 23F had 2- to 2.5-fold higher ORs, although these were not markedly different from the ORs of nonvaccine serotypes. None of the major clones had an OR that was significantly greater than the average, and the differences in ORs among serotypes and clones were much less than those for invasive disease, suggesting little variation in their ability to cause AOM. We conclude that serotype replacement may reduce the long-term efficacy of these vaccines against AOM