3.1 Study selection
As shown in Figure 1 , a total of 12,279 records were retrieved from the electronic databases, of which 84.5% were provided by VHL, Scopus, and PubMed. In total, 4,815 publications remained after duplicates were removed and once the screening of titles and abstract was completed, 340 publications were retrieved in full text for final eligibility. A total of 157 publications that met the inclusion criteria were included in the quantitative synthesis. Among the 183 full text publications that were excluded, the main reasons were: assessed SNT isolates previously obtained (56.8%), lacked the defined population (21.3%), and not a full text or other type of study different than the defined (10.9%). A list of the publications that were excluded and the primary reason for exclusion are provided in Supplementary Table 2 and a full reference list with all the included publications is presented in Supplementary Table 3 .