Molecular Characterization of Streptococcus pneumoniae Serotype 12F Isolates Associated with Rural Community Outbreaks in Alaska

Whole-Genome Sequencing Reveals the Origin and Rapid Evolution of an Emerging Outbreak Strain ofStreptococcus pneumoniae12F

“…Finally, the 12F capsular polysaccharide is expressed by at least 4 different multilocus sequence typing (MLST)-defined clonal complexes (CC218, CC969, CC1527, CC3524). The 2003-2006 outbreak in Alaska was caused by CC1527 [8], but all of the other listed outbreaks were caused by CC218 [13]. Within CC218, there are 2 major genetic clusters identified by their predominant sequence type as ST218 and ST220 (singleallele variant of ST218); both cause outbreaks and both are globally dispersed.…”

“…Second, 12F is associated with outbreaks of invasive disease, often among adults but occasionally among children as well [8]. Several 12F outbreaks have been reported in the United States over the past 25 years, mainly among people living in crowded conditions, including outbreaks in a Texas jail in 1989 [9], in a Maryland daycare center in 1992 [10], in a California homeless shelter in 2004 [11], and in 2 waves of outbreaks in a rural region of Alaska between 2003 and 2006, and again between 2006 and 2008 [8]. In addition, a 12F outbreak of invasive pneumococcal disease occurred in central Australia in 1995 [12].…”

“…First, serotype 12F is rarely carried in the nasopharynx of healthy persons [8], implying there is less chance to acquire antibiotic resistance in this niche via horizontal gene transfer from other clones. Second, 12F is associated with outbreaks of invasive disease, often among adults but occasionally among children as well [8].…”

“…First, serotype 12F is rarely carried in the nasopharynx of healthy persons [8], implying there is less chance to acquire antibiotic resistance in this niche via horizontal gene transfer from other clones. Second, 12F is associated with outbreaks of invasive disease, often among adults but occasionally among children as well [8]. Several 12F outbreaks have been reported in the United States over the past 25 years, mainly among people living in crowded conditions, including outbreaks in a Texas jail in 1989 [9], in a Maryland daycare center in 1992 [10], in a California homeless shelter in 2004 [11], and in 2 waves of outbreaks in a rural region of Alaska between 2003 and 2006, and again between 2006 and 2008 [8].…”

ntrafamily Transmission of Streptococcus pneumoniae and the Protective Power of Vaccination

“…However, even infectious diseases specialists rarely associate S. pneumoniae with outbreaks. But awareness seems to increase as several outbreak reports were published just recently [10][11][12][13][14].…”