Table 1 

A. Definition of the variables (MC, Ar, SI) used in SpolDB4 to define : (1) the geographic index C1 (Endemic, Localized, Ubiquitous) (2) the quantitative index C2 (Epidemic, Common, Recurrent, Rare). B. Distribution of the 1939 Sharedtypes in 12 classes. 

Name 
Abbreviation 
Type of data, Def. 
Rules for Definition of Qualifiers (C1 and C2) 



A Definitions 

Matching Code 
MC 
1–8 digits, built by linking region codes 
If 1 digit, then C1 = Endemic (genotype found in one macroregion only) If 2 digits, then C1 = Localized (genotype found in two macroregions) If ≥ 3 digits, go to Area section below for further interpretation 

Area 
Ar 
numeric, n° of countries in which a given SIT is found 
If MC ≥ 3 digits and Areas ≤ 5; C1 = Localized If MC ≥ 3 digits and Areas ≥ 6; C1 = Ubiquitous (genotype found in more than three macroregions) 

Spreading Index 
SI 
numeric, mean indicator of spreading independent of geography SI = n/Ar where n is the absolute value for a given sharedtype 
If SI ≥ 25; C2 = Epidemic If 10 < SI < 24; C2 = Common If 3 < SI < 9; C2 = Recurrent If SI ≤ 2; C2 = Rare 

B Distribution of the 1939 genotypes in 12 class 

Endemic Epidemic 
6 
Endemic Recurrent 
286 

Localized Epidemic 
2 
Localized Recurrent 
207 

Ubiquitous Epidemic 
6 
Ubiquitous Recurrent 
176 

Endemic Common 
31 
Endemic Rare 
501 

Localized Common 
14 
Localized Rare 
587 

Ubiquitous Common 
20 
Ubiquitous Rare 
82 

NA* 
21 
Total 
1939 

*not applicable 



Brudey et al. BMC Microbiology 2006 6:23 doi:10.1186/14712180623 