Background Many bacteria and archaea possess a defense system called clustered regularly interspaced short palindromic repeats (CRISPR) associated proteins (CRISPR-Cas system) against invaders such as phages or plasmids. This system has not been demonstrated in Helicobacter pylori. The numbers of spacer in CRISPR array differ among bacterial strains and can be used as a genetic marker for bacte...

Staphylococcal enterotoxins (SEs) are a family of 17 major serological types of heat-stable enterotoxins that are one of the leading causes of gastroenteritis resulting from consumption of contaminated food. SEs are considered potential bioweapons. Many Staphylococcus aureus isolates contain multiple SEs. Because of the large number of SEs, serological typing and PCR typing are laborious and ti...

The genetic background and the presence of several virulence factors of Staphylococcus aureus isolates from intensive care unit (ICU) patients from 14 hospitals in The Netherlands isolated from 1996 until 2006 were investigated. In total, 936 methicillin-susceptible S. aureus (MSSA) and 7 methicillin-resistant S. aureus (MRSA) isolates were collected. The genetic background was determined by sp...

is consensual due to the dissimilar genetic characteristics or discriminatory power of the loci enrolled in each of those. Although it is assumed that the typing schemes should ideally ensure that the chosen loci are stable over the course of evolution, this issue is of difficult assessment. Labiran et al. (2012) have now presented a study where they have assessed the stability of some regions ...

To investigate the epidemiology and genetic structure of Staphylococcus aureus bacteremia in China, a total of 416 isolates from 22 teaching hospitals in 12 cities from 2013 and 2016 were characterized by antibiogram analysis, multilocus sequence typing (MLST), spa typing and staphylococcal cassette chromosome mec (SCCmec) typing. The predominant meticillin-susceptible (MSSA) genotypes in 2013 ...

It is unclear whether the genetic background of drug-resistant Pseudomonas aeruginosa was disseminated from a certain clone. Thus, we performed MLST (multilocus sequence typing) of 896 P. aeruginosa isolates that were nonsusceptible to imipenem, meropenem, or ceftazidime. This revealed 254 sequence types (STs), including 104 new STs and 34 STs with novel alleles. Thirty-three clonal complexes a...

Genetic variation in an infectious disease pathogen can be driven by ecological niche dissimilarities arising from different host species and different geographical locations. Whole genome sequencing was used to compare E. coli O157 isolates from host reservoirs (cattle and sheep) from Scotland and to compare genetic variation of isolates (human, animal, environmental/food) obtained from Scotla...

Genetic diversity and differentiation, inferred by typing the polymorphic genes coding for the merozoite surface proteins 1 (Msp-1) and 2 (Msp-2), were compared for 345 isolates belonging to seven Plasmodium falciparum populations from three continents. Both loci yielded similar estimates of genetic diversity for each population, but rather different patterns of between-population differentiati...

BACKGROUND Most studies of the dynamics of maternal group B Streptococcus (GBS) colonization have relied on capsular serotyping to define GBS acquisition or loss. Newer molecular methods that distinguish GBS clones may expand our knowledge and influence vaccination strategies. We used multilocus sequence typing (MLST) and GBS capsular gene cluster (cps) genotyping to investigate the dynamics of...

Gv1 is a genetic locus that coordinately regulates the expression of multiple murine leukemia virus-related endogenous proviral sequences. A quantitative nuclease protection assay for typing Gv1 inheritance has been developed. Use of this assay demonstrates that Gv1 controls transcription of polytropic but not of modified polytropic endogenous proviruses. A combination of genetic techniques wer...