Collectively, the results of pig infection experiments demonstrated clearly that both strains (98HAH12 and 05ZYH33) responsible for STSS are of high virulence, and they seem to share much more invasiveness than the Holland virulent strain S10.
Methicillin-sensitive staphylococci, streptococci, and anaerobic cocci are commonly considered as low-virulence bacteria causing low-grade periprosthetic infections; methicillin-resistant staphylococci, enterococci, and gram-negative organisms are certainly considered bacteria of high virulence due to their intrinsic resistance to antimicrobial agents and antibiotics [8].
These data may be from a highly biased sample set, but they are indicative of higher virulence in A.I strain infections.
To shed light on the mystery of high virulence of the epidemic outbreak strains of SS2, our joint research group completed a comprehensive study of comparative genomics, decoding the whole genome sequences of two virulent SS2 strains (98HAH12 and 05ZYH33) isolated from Chinese infected patients [6].
Based on the activity of thioridazine against M. tuberculosis H37Rv (Figure 1) and the fact that its efficacy is unrelated to strain type or levels of first- or second-line drug resistance [7], [23], it is likely that its activity would have been equal if a strain of higher virulence had been used.
Variant PEDV strains of high virulence emerged in China in 2010 201111 [ 4].
However, experimental studies to confirm the potential of high virulence of S INDEL PEDV are lacking to date.
Our analyses show that strains of higher virulence have a higher viral shedding rate, and more rapidly kill hosts.
Species of high virulence, such as Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and even Neisseria meningitidis, have been reported [ 3].
In vivo serial passages often lead to evolution of high virulence, apparently due to relaxed transmission costs [ 4].
