We report a novel phenotype of methicillin resistance, designated "Eagle-type" resistance, which is characteristic in its resistance to high concentrations of methicillin (64 to 512 microg/ml) and susceptibility to low concentrations of methicillin (2 to 16 microg/ml). The type of resistance was expressed in mutant strains selected with high concentrations (e.g., 128 to 512 microg/ml) of methic...

Antonio F Garćia Maŕin, Gerhard Heinzel, Roland Schilling, Albrecht Rüdiger, Vinzenz Wand, Frank Steier, Felipe Guzmán Cervantes, Andreas Weidner, Oliver Jennrich, Francisco J Meca Meca and K. Danzmann 1 Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, D-30167 Hannover, Germany 2 ESTEC, Noordwijk, The Netherlands 3 Universidad de Alcalá de Henares Ctra. d...

Staphylococcus aureus is a major cause of mastitis in dairy cattle. This study estimated the herd prevalence of methicillin-resistant Staph. aureus (MRSA) among US dairy herds by testing bulk tank milk (BTM) samples using genotypic and phenotypic methods. A nationally representative sample of 542 operations had BTM cultured for Staph. aureus, and 218 BTM samples were positive upon initial cultu...

Staphylococcus aureus is a main cause of bovine mastitis and a major pathogen affecting human health. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) has become a significant concern for both animal health and public health. This study investigated the incidence of MRSA in milk samples collected from dairy cows with clinical mastitis and characterized the MRSA iso...

UNLABELLED Cefoxitin is a potent inducer of the mecA regulatory system. It is being recommended for detection of methicillin resistance in Staphylococcus aureus (MRSA) when using disk diffusion testing. The aim of our study was to evaluate the efficacy of cefoxitin disc diffusion test to characterize MRSA and compare it with oxacillin agar screening and detection of mecA gene by PCR. MATERIAL...

Staphylococcus saprophyticus is a uropathogenic bacterium that causes acute uncomplicated urinary tract infections, particularly in female outpatients. We investigated the dissemination and antimicrobial susceptibilities of 101 S. saprophyticus isolates from the genitourinary tracts of patients in Japan. Eight of these isolates were mecA positive and showed beta-lactam resistance. Pulsed-field ...

The inactivation of synaptic serotonin (5-hydroxytryptamine, 5-HT) is largely established through the actions of the presynaptic, antidepressant-sensitive 5-HT transporter (SERT, SLC6A4). Recent studies have demonstrated post-translational regulation of SERT mediated by multiple Ser/Thr kinases, including protein kinases C and G (PKC and PKG) and p38 mitogen-activated protein kinase (MAPK), as ...

Reports of oxacillin-susceptible mecA-positive Staphylococcus aureus strains are on the rise. Because of their susceptibility to oxacillin and cefoxitin, it is very difficult to detect them by using routine phenotypic methods. We describe two such isolates that were detected by chromogenic medium and confirmed by characterization of the mecA gene element.

A lack of sigma(B) activity reduces methicillin resistance in heterogeneous Staphylococcus epidermidis 1057, whereas inactivation of the anti-sigma factor RsbW switched the phenotype to homogeneous expression of resistance. Oxacillin induction of mecA transcription is reduced in a sigma(B)-negative strain. However, mecA is not involved in the switch of expression phenotype.

The mecA gene was lost in 36 (14.4%) of 250 methicillin-resistant Staphylococcus aureus isolates after 2 years of storage at -80 degrees C with the Microbank system (Pro-lab Diagnostics, Austin, Tex.). Further analysis of 35 of these isolates confirmed loss of the mecA gene in 32 isolates. This finding has important implications for the management of strain collections.