Molecular capsular typing was successful in identifying a capsular serotype gene in 173 (95.1%) of the 182 serologically non-typable colonizing isolates (Table 1).
Multiple genomovars have been noted for some serotypes (30 ) and most likely arose from horizontal gene transfer of the same assortment of serotype antigen genes into distinct genetic lineages by coincidence.
Alternatively, using an AAV cap gene library produced by DNA shuffling of different AAV serotype capsid genes, Yang et al. obtained a myocardium-tropic AAV strain, AAVM41, through direct evolution strategies and DNA shuffling.
As for deducting any hypothesis regarding difference in virulence among serotypes, the genes which displayed significant serotype related down-regulation in response to iron limitation were not very useful (genes marked with a number sign in Table 2).
Serotype-specific genes selected from the cps locus were wchD (serotype 1), wchE (serotype 3), wzy (serotype 4), whaC-whaD (serotype 5), wzy-wzx (6A/B/C), aliB (7A/F), cps9vJ (9A/V), wzy (14), gct (18B/C), mnaA (19A), wzy (19F), and wzy-wchV (23F).
Most of these are designed to identify virulence factors such as Shiga toxin and intimin as well as E. coli O and H antigen serotype specific genes.
neoformans (serotype D) genes as PMT1D, PMT2D, and PMT4D.
These phage are integrated into the host chromosome, forming a prophage that stably expresses serotype conversion genes [ 7].
When estimating the combined effect of treatment and serotype, 12 genes also displayed significant (p < 0.0001; estimated false positive error rate of 0.5%) serotype related response to iron limitation, three were up-regulated and 9 down-regulated (marked in Table 1 and 2).
Genomic DNA was extracted from all K. pneumoniae strains (QIAGEN DNA extraction kit, QIAGEN, USA) and the rmpA and serotype-specific genes for the K1, and K2 capsular serotypes were amplified by polymerase chain reaction (PCR) as previously reported [ 16, 17].
