Mutations in rot restore in vitro toxin production to agr-negative strains of Staphylococcus aureus. We show that a rot mutation returns wild-type virulence to an agr mutant, as measured in experimental endocarditis infections by target organ bacterial counts. Implications of our data are discussed in terms of agr antagonist strategies.

Multi-drug resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) cause nosocomial infections that can have deleterious effects on human health. Thus, it is imperative to find solutions treat these detrimental well control their spread. We tested the effect of two different antimicrobial materials, functionalised graphene oxide (GOX), and AGXX® coated cellulose fibres, g...

Staphylococcus epidermidis is a common commensal of healthy conjunctiva and it can cause endophthalmitis, however its presence in conjunctivitis, keratitis and blepharitis is unknown. Molecular genotyping of S. epidermidis from healthy conjunctiva could provide information about the origin of the strains that infect the eye. In this paper two collections of S. epidermidis were used: one from oc...

BACKGROUND Staphylococcus aureus, with reduced vancomycin susceptibility, is probably under the regulation of several genes and various express phenotypes. OBJECTIVES This study aimed to investigate the phenotypic differences between vancomycin-susceptible S. aureus (VSSA), vancomycin-intermediate S. aureus (VISA), and heterogeneous VISA (hVISA) isolates. MATERIALS AND METHODS A total of 13...

Tetracycline resistance has been postulated as a potential phenotypic marker of livestock-associated lineage ST398 amongst meticillin-resistant Staphylococcus aureus (MRSA) clinical isolates in some European hospitals. The objective of this study was to determine if this marker could also be applied to Maghrebian countries. In total, 99 MRSA isolates were collected in a Tunisian hospital during...

BACKGROUND Chronic inflammation is known to be one of the main steps in carcinogenesis. Identification of those with chronic inflammation may help identify subjects at risk of cancer. Previous studies have reported low albumin-to-globulin ratio (AGR) to be associated with increased cancer mortality in cancer patients, but there has been no study based on healthy populations. PATIENTS AND METH...

The goal of this work was to determine whether staphylococcal enterotoxin type A gene (sea) expression is regulated by an accessory gene regulator (agr). The Tn551 insertionally inactivated agr allele of Staphylococcus aureus ISP546 was transferred to three Sea+ S. aureus strains. Each of the Agr- strains produced as much staphylococcal enterotoxin A (SEA) as its parent strain. These results su...

A competitive reverse transcription-PCR method was developed for the semiquantitation of the expression of genes encoding bicomponent leucotoxins of Staphylococcus aureus, e.g., Panton-Valentine leucocidin (lukPV), gamma-hemolysin (hlgA and hlgCB), and LukE-LukD (lukED). The optimization procedure included RNA preparation; reverse transcription; the use of various amounts of enzymes, antisense ...

Biofilm formation is regarded as one of the major determinants in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) as pathogens of medical device-related infection. However, methicillin-susceptible S. aureus (MSSA) can also form biofilm in vitro and such biofilms are resistant to vancomycin. Hence, researching the possible mechanisms of MSSA biofilm formation is urgent and n...

The aim of this study was to evaluate the cultivation potential of cartilage taken from the debrided edge of a chronic lesion of the articular surface. A total of 14 patients underwent arthroscopy of the knee for a chronic lesion on the femoral condyles or trochlea. In addition to the routine cartilage biopsy, a second biopsy of cartilage was taken from the edge of the lesion. The cells isolate...