Nationwide prevalence of human papillomavirus infection and viral genotype distribution in 37 cities in China.

Background: Type-specific high-risk HPV (hrHPV) infection is related to cervical carcinogenesis. The prevalence of hrHPV infection varies geographically, which might reflect the epidemiological characteristics of cervical cancer among different populations. To establish a foundation for HPV-based screening and vaccination programs in China, we investigated the most recent HPV prevalence and genotypic distributions in different female age groups and geographical regions in China.

Penicillin-binding proteins and cell wall composition in beta-lactam-sensitive and -resistant strains of Staphylococcus sciuri.

A close homologue of the acquired Staphylococcus aureus mecA gene is present as a native gene in Staphylococcus sciuri. We determined the patterns of penicillin-binding proteins (PBPs) and the peptidoglycan compositions of several S. sciuri strains to explore the functions of this mecA homologue, named pbpD, in its native S.

Tracking the in vivo evolution of multidrug resistance in Staphylococcus aureus by whole-genome sequencing.

The spread of multidrug-resistant Staphylococcus aureus (MRSA) strains in the clinical environment has begun to pose serious limits to treatment options. Yet virtually nothing is known about how resistance traits are acquired in vivo. Here, we apply the power of whole-genome sequencing to identify steps in the evolution of multidrug resistance in isogenic S.

Overexpression of genes of the cell wall stimulon in clinical isolates of Staphylococcus aureus exhibiting vancomycin-intermediate- S. aureus-type resistance to vancomycin.

Custom-designed gene chips (Affymetrix) were used to determine genetic relatedness and gene expression profiles in Staphylococcus aureus isolates with increasing MICs of vancomycin that were recovered over a period of several weeks from the blood and heart valve of a patient undergoing extensive vancomycin therapy. The isolates were found to be isogenic as determined by the GeneChip based genotyping approach and thus represented a unique opportunity to study changes in gene expression that may contribute to the vancomycin resistance phenotype. No differences in gene expression were detected between the parent strain, JH1, and JH15, isolated from the nares of a patient contact.

Expression of high-level methicillin resistance in Staphylococcus aureus from the Staphylococcus sciuri mec A homologue: role of mutation(s) in the genetic background and in the coding region of mec A.

A close homologue of the mec A gene, the primary drug resistance determinant in methicillin resistant Staphylococcus aureus (MRSA), is ubiquitous in the animal commensal species Staphylococcus sciuri, yet most isolates of this staphylococcal species are susceptible to beta-lactam antibiotics including methicillin. Recently, we showed that in a methicillin-resistant mutant of S. sciuri prepared in the laboratory, the mec A homologue is converted to an antibiotic resistance gene by a point mutation introduced into the -10 consensus of the promoter and such promoter-up mutants of the S.

High-level (beta)-lactam resistance and cell wall synthesis catalyzed by the mecA homologue of Staphylococcus sciuri introduced into Staphylococcus aureus.

A close homologue of mecA, the determinant of broad-spectrum beta-lactam resistance in Staphylococcus aureus was recently identified as a native gene in the animal commensal species Staphylococcus sciuri. Introduction of the mecA homologue from a methicillin-resistant strain of S. sciuri into a susceptible strain of S.

Penicillin-binding protein 2 is essential for expression of high-level vancomycin resistance and cell wall synthesis in vancomycin-resistant Staphylococcus aureus carrying the enterococcal vanA gene complex.

A combination of biochemical and genetic experiments were performed in order to better understand the mechanism of expression of high-level vancomycin resistance in Staphylococcus aureus. The transcription of pbp2 of the highly vancomycin- and oxacillin-resistant strain COLVA200 and its mutant derivative with inactivated mecA were put under the control of an inducible promoter, and the dependence of oxacillin and vancomycin resistance and cell wall composition on the concentration of the isopropyl-beta-D-thiogalactopyranoside inducer was determined. The results indicate that mecA--the genetic determinant of oxacillin resistance--while essential for oxacillin resistance, is not involved with the expression of vancomycin resistance.

Expression, purification and crystallization of an extended-spectrum beta-lactamase from Klebsiella oxytoca.

OXY-1a is an extended-spectrum beta-lactamase from the conditional pathogenic bacterium Klebsiella oxytoca. OXY-1a is responsible for the antibiotic resistance of this pathogen. A soluble form of OXY-1a with a His tag at its C-terminus was overexpressed in Escherichia coli.

Development of methicillin resistance in clinical isolates of Staphylococcus sciuri by transcriptional activation of the mecA homologue native to s.

The beta-lactam resistance gene mecA was acquired by Staphylococcus aureus from an extraspecies source. The search for the possible origin of this gene has led to the identification of a close structural homologue of mecA as a native gene in the animal species Staphylococcus sciuri. Surprisingly, the overwhelming majority of S.