Staphylococcus aureus is recognized worldwide as a pathogen causing many serious diseases in humans and animals, and is one of the most important etiological agents of clinical and subclinical bovine mastitis. The aim of the present study was to investigate and correlate properties, that may be associated with persistent mastitis, of S. aureus strains isolated from milk of cows suffering from m...

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...

The Agr quorum-sensing system represents the master regulator for staphylococcal virulence factors and is known to have a strong impact on the release of pathogen-associated molecular pattern (PAMP) molecules. Among the various staphylococcal PAMPs, phenol-soluble modulin (PSM) peptides have attracted increasing interest because they are crucial for staphylococcal virulence and have neutrophil-...

Staphylococcus spp. play an important role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most relevant species due to the production of virulence factors such as slime, which is required for biofilm formation. This study aimed to evaluate biofilm production and its possible relation to beta-lactamic resistance in 20 S. aureus isolates from bovine mastitic milk. The...

Sensory neurons provide important feedback to pattern-generating motor systems. In the crustacean stomatogastric nervous system (STNS), feedback from the anterior gastric receptor (AGR), a muscle receptor neuron, shapes the activity of motor circuits in the stomatogastric ganglion (STG) via polysynaptic pathways involving anterior ganglia. The AGR soma is located in the dorsal ventricular nerve...

The global regulatory locus sarA comprises a 375-bp open reading frame that is driven by three promoters, the proximal P1 and distal P3 and P2 promoters. We mutated the weaker P3 and P2 promoters to ascertain the effect of the change on SarA protein and target gene expression. Our results indicated that the solely active P1 promoter led to a lower SarA protein level, which has an effect on agr ...

We appreciate the letter to the editor by Alkan et al. [1] in response to our recently published article [2]. Alkan et al. bring up some potentially valid points about our study. They suggest rheumatic diseases should have been excluded from the study population, as these conditions are ‘important causatives for chronic inflammation.’ They also suggest the inclusion of elderly subjects older th...

The synthesis of virulence factors and other extracellular proteins responsible for pathogenicity in Staphylococcus aureus is under the control of the agr locus. A secreted agr-encoded peptide, AgrD, processed from the AgrD gene product, is known to be an effector of self-strain activation and cross-strain inhibition of the agr response. Biochemical analysis of AgrD peptides isolated from cultu...

Many locomotor activities require muscles to actively lengthen, dissipate energy and decelerate the body. These eccentric contractions can disrupt cytoskeletal structures within myofibrils and reduce force output. We examined how architectural features of pennate muscles can provide a protective mechanism against eccentric muscle damage by limiting fascicle lengthening. It has been previously s...