Specific cut-off values for each target.

<p>*Anti-PVL_2 Antibody detects exclusive epitopes of lukF-P83. Positive signals for two of the anti-PVL antibodies, 1, 2 or 3, indicate for the target lukF-PV.</p><p>Specific cut-off values for each target.</p

<i>Staphylococcus aureus In Vitro</i> Secretion of Alpha Toxin (hla) Correlates with the Affiliation to Clonal Complexes

<div><p>The alpha toxin of <i>Staphylococcus aureus</i> is a pore forming toxin that penetrates host cell membranes causing osmotic swelling, rupture, lysis and subsequently cell death. Haemolysin alpha is toxic to a wide range of different mammalian cells; i.e., neurotoxic, dermonecrotic, haemolytic, and it can cause lethality in a wide variety of animals. In this study, the <i>in vitro</i> alpha toxin production of 648 previously genotyped isolates of <i>S. aureus</i> was measured quantitatively using antibody microarrays. Isolates originated from medical and veterinary settings and were selected in order to represent diverse clonal complexes and defined clinical conditions. Generally, the production of alpha toxin <i>in vitro</i> is related to the clonal complex affiliation. For clonal complexes CC22, CC30, CC45, CC479, CC705 and others, invariably no alpha toxin production was noted under the given <i>in vitro</i> conditions, while others, such as CC1, CC5, CC8, CC15 or CC96 secreted variable or high levels of alpha toxin. There was no correlation between alpha toxin yield and clinical course of the disease, or between alpha toxin yield and host species.</p></div

Layout of the protein microarray.

<p>(A) Positions of each substance on the chip. (B) Legend to the probes. (C) Picture of a processed fluorescent microarray. (D) Bar graph with signal intensities for the expressed proteins.</p

Alpha Toxin yields and clinical outcome (veterinary isolates excluded).

<p>Alpha Toxin yields and clinical outcome (veterinary isolates excluded).</p

Molecular Typing of MRSA and of Clinical <i>Staphylococcus aureus</i> Isolates from Iaşi, Romania

<div><p>Romania is one of the countries with the highest prevalence of methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) in the world. To obtain data on affiliation of MRSA to strains and clonal complexes and on the population of methicillin susceptible <i>S. aureus</i> (MSSA), clinical isolates from bloodstream infections, skin and soft tissue infections as well as from screening swabs were collected at hospitals in Ia?i, a city in the North-Eastern part of Romania. Isolates were characterised by microarray hybridisation. Nearly half of all isolates (47%), and about one third (34%) of bloodstream isolates were MRSA. The prevalence of the Panton-Valentine leukocidin (PVL) was also high (31% among MRSA, 14% among MSSA). The most common MRSA strain was a PVL-negative CC1-MRSA-IV that might have emerged locally, as a related MSSA was also common. PVL-positive CC8-MRSA-IV (“USA300”) and PVL-negative ST239-like MRSA-III were also frequently found while other MRSA strains were only sporadically detected. Among MSSA, PVL-positive CC121 as well as PVL-negative CC1, CC22 and CC45 predominated. Although this study provides only a snapshot of <i>S. aureus</i>/MRSA epidemiology in Romania, it confirms the high burden of MRSA and PVL on Romanian healthcare settings.</p></div

Alpha Toxin yields and <i>agr</i> group affiliation.

<p>Alpha Toxin yields and <i>agr</i> group affiliation.</p

Alpha Toxin yields by CC/ST affiliation.

<p>Alpha Toxin yields by CC/ST affiliation.</p

Population structures for the total sample and for the isolates from different diagnoses.

<p>Population structures for the total sample and for the isolates from different diagnoses.</p

Virulence-associated genes in MRSA, MSSA and in isolates from different diagnoses.

<p>Virulence-associated genes in MRSA, MSSA and in isolates from different diagnoses.</p

Resistance genes in MRSA, MSSA and in isolates from different diagnoses.

<p>Resistance genes in MRSA, MSSA and in isolates from different diagnoses.</p