Clustering of Staphylococcus aureus bovine mastitis strains from regions of Central-Eastern Poland based on their biochemical and genetic characteristics

Staphylococcus aureus strains were isolated from mastitic milk of cows with infected mammary glands. The animals were living in 12 different farms near Lublin, in Central-Eastern Poland. A biochemical identification method based on enzymatic assay was performed, followed by haemolytic and proteolytic tests. PCR-RFLP targeted on the gap gene allowed the genetic identification of strains at the species level and verified phenotypic identification results. A molecular typing method using triplex PCR was performed to recognize the genetic similarity of the analyzed strains. DNA microarray hybridization (StaphyType, Alere Technologies) was used for detection of antibiotic resistance and virulence associated markers. The results obtained indicate high genetic similarity in strains isolated from the same sites. High genetic similarities were also detected between strains isolated from cows from different farms of the same region. A slightly lower similarity was noted however, in strains from various regions indicating that the strains are herd specific and that the cow's infections caused by S. aureus were of a clonal character. In 21 representative isolates selected for DNA-microarray testing, only fosfomycin (fosB) and penicillin resistance markers (blaZ, blaI, blaR) were detected. The presence of genes coding for haemolysins (lukF, lukS, hlgA, hla, hld, hlb), proteases (aur, sspA, sspB, sspP), enterotoxins (entA, entD, entG, entI, entJ, entM, entN, entO, entR, entU, egc-cluster), adhesins (icaA, icaC, icaD, bbp, clfA, clfB, fib, fnbA, map, vwb) or immune evasion proteins (scn, chp, sak) was common and, with exceptions, matched triplex PCR-defined clusters

Prediction of HIV-1 virus-host protein interactions using virus and host sequence motifs

<p>Abstract</p> <p>Background</p> <p>Host protein-protein interaction networks are altered by invading virus proteins, which create new interactions, and modify or destroy others. The resulting network topology favors excessive amounts of virus production in a stressed host cell network. Short linear peptide motifs common to both virus and host provide the basis for host network modification.</p> <p>Methods</p> <p>We focused our host-pathogen study on the binding and competing interactions of HIV-1 and human proteins. We showed that peptide motifs conserved across 70% of HIV-1 subtype B and C samples occurred in similar positions on HIV-1 proteins, and we documented protein domains that interact with these conserved motifs. We predicted which human proteins may be targeted by HIV-1 by taking pairs of human proteins that may interact via a motif conserved in HIV-1 and the corresponding interacting protein domain.</p> <p>Results</p> <p>Our predictions were enriched with host proteins known to interact with HIV-1 proteins ENV, NEF, and TAT (p-value < 4.26E-21). Cellular pathways statistically enriched for our predictions include the T cell receptor signaling, natural killer cell mediated cytotoxicity, cell cycle, and apoptosis pathways. Gene Ontology molecular function level 5 categories enriched with both predicted and confirmed HIV-1 targeted proteins included categories associated with phosphorylation events and adenyl ribonucleotide binding.</p> <p>Conclusion</p> <p>A list of host proteins highly enriched with those targeted by HIV-1 proteins can be obtained by searching for host protein motifs along virus protein sequences. The resulting set of host proteins predicted to be targeted by virus proteins will become more accurate with better annotations of motifs and domains. Nevertheless, our study validates the role of linear binding motifs shared by virus and host proteins as an important part of the crosstalk between virus and host.</p

Standardising Clinical Caremaps: Model, Method and Graphical Notation for Caremap Specification

Standardising care can improve patient safety and outcomes, and reduce the cost of providing healthcare services. Caremaps were developed to standardise care, but contemporary caremaps are not standardised. Confusion persists in terms of terminology, structure, content and development process. Unlike existing methods in the literature, the approach, model and notation presented in this chapter pays special attention to incorporation of clinical decision points as first-class citizens within the modelling process. The resulting caremap with decision points is evaluated through creation of a caremap for women with gestational diabetes mellitus. The proposed method was found to be an effective way for comprehensively specifying all features of caremaps in a standardised way that can be easily understood by clinicians. This chapter contributes a new standardised method, model and notation for caremap content, structure and development

Relations between magnesium, calcium and plasma renin activity in black and white hypertensive patients

The heterogeneous status of magnesium and calcium metabolism in the hypertensive population may be related to the plasma renin activity (PRA). This study investigates the relationships between serum and erythrocyte magnesium (Mg2+) and calcium (Ca2+) concentrations and PRA in black and white essential hypertensive patients. Thirty-nine normotensive (20 black, 19 white) and 47 hypertensive (25 black, 22 white) subjects were studied. The PRA was measured by radioimmunoassay, Mg2+ and Ca2+ by atomic absorption spectroscopy, and serum ionized Ca2+ by a specific electrode. PRA and ionized Ca2+ were significantly lower in the black hypertensive as compared with the white hypertensive group (1.99 +/- 0.33 vs. 5.96 +/- 1.02 ng/ml/h for PRA; 1.28 +/- 0.07 vs. 1.42 +/- 0.01 mmol/l for ionized Ca2+: black hypertensives vs. white hypertensives p &#60; 0.05). Ionized Ca2+ was significantly increased (p &#60; 0.05) in the white hypertensive patients as compared with the normotensive controls (1.42 +/- 0.01 vs. 1.29 +/- 0.04 mmol/l). In the black hypertensive group, serum and erythrocyte Mg2+ were significantly (p &#60; 0.05) decreased as compared with the other groups. The erythrocyte Ca2+ concentration was significantly elevated in both black and white hypertensive patients. In the group as a whole, serum Mg2+ and PRA were negatively correlated and ionized Ca2+ and PRA and ionized Ca2+ and erythrocyte Ca2+ positively correlated. However, in the subgroups, these correlations were only significant in the white group: r = -0.67 and p &#60; 0.05 serum Mg2+ vs. PRA; r = 0.64, and p &#60; 0.05 ionized Ca2+ vs. PRA; r = 0.82 and p &#60; 0.01 ionized [Ca2+]i vs. erythrocyte Ca2+. These data suggest a relationship between PRA, Mg2+, and Ca2+ which may be more important in white than in black hypertensive patients

Postprandial Hyperglycemia in Urban South African Blacks with and without Coronary Artery Disease

Background: Coronary artery disease (CAD) is increasing in urban black South Africans during their transition from a rural to a western lifestyle. This study assessed postprandial hyperglycemia, which a risk factor for CAD, in blacks with and without CAD. Methods: Fasting lipid levels and postprandial glucometabolic profiles were measured in 40 patients and 20 controls. Normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and diabetes mellitus (DM) were categorized according to American Diabetes Association criteria. Postprandial hyperglycemia was assessed by the oral glucose tolerance test (OGTT) and area under curve (AUC) analysis. Insulin resistance was evaluated by hyperinsulinemic euglycemic clamp (insulin-mediated glucose disposal, M-value). Results: Glucose AUC was higher in patients than controls (p < 0.0001). Highest correlations were between AUC and 0-minute glucose (r = 0.7847; p < 0.0001), and 120-minute glucose (r = 0.9187; p < 0.0001). Patients had higher fasting and postprandial glucose responses (p < 0.05). Glucose concentrations increased among NGT, IGT, and DM categories in patients (p < 0.001) and controls (p < 0.01). Abnormal glucose tolerance was more prevalent in patients (50%) than controls (40%). M-values were lower in patients (p < 0.0001) and decreased between categories, significantly in DM patients (p < 0.02). More patients (70%) than controls (13%) had low M-values (p < 0.001). Conclusions: Postprandial hyperglycemia was common in black CAD patients and glucose concentrations at 0 minute and 120 minutes were the strongest determinants. As glucose tolerance declined, glycemic control deteriorated and insulin resistance worsened. Abnormal glucose tolerance and insulin resistance were more prevalent in patients with CAD

The metabolic syndrome using the National Cholesterol Education Program and International Diabetes Federation definitions among urbanised black South Africans with established coronary artery disease

Background. The International Diabetes Federation (IDF) introduced a new definition of the metabolic syndrome (MS) that emphasises ethnic-specific cut-offs for waist circumference (WC). Objective. To compare MS prevalence rates using the National Cholesterol Education Program Adult Treatment Panel III (NCEP: ATP III) and IDF definitions. Methods. Anthropometric data, fasting biochemical variables and MS prevalence rates were measured in 40 black patients with established coronary artery disease (CAD). Glucose metabolism was assessed using the oral glucose tolerance test (OGTT), and insulin-mediated glucose disposal (M-value) was evaluated using the hyperinsulinaemic euglycaemic clamp technique. Results. Based on the NCEP: ATP III definition, MS prevalence was 60% and using the IDF definition, it was 57.5%. The two definitions similarly classified ~83% of patients as being MS positive or MS negative. Lower WC cut-offs in the IDF definition classified greater numbers of men and women as having WC as a risk factor – IDF v. NCEP: ATP III men 57.6% v. 36.4%; women 100% v. 71.4%. Impaired glucose tolerance (IGT) was found in 12 of the 40 patients (30%) and diabetes mellitus (DM) in 8 (20%). Mean M-value was reduced in IGT and DM groups compared with the normal group, significantly so in the DM group (p = 0.01). Conclusions. NCEP: ATP III and IDF definitions both generated similar MS prevalence estimates. The two definitions similarly identified the presence or absence of the MS in the majority of patients. The IDF definition classified greater numbers of men and women as having WC as a risk factor. There was a high prevalence of previously undiagnosed IGT and DM in our South African black patients with established CAD. Journal of Endocrinology, Metabolism and Diabetes of South Africa Vol. 12 (1) 2007: pp. 6-1

Leptin, Adiponectin, and High-Sensitivity C-Reactive Protein in Relation to the Metabolic Syndrome in Urban South African Blacks With and Without Coronary Artery Disease

Background: Metabolic syndrome and coronary artery disease (CAD) are increasing in urban black South Africans during their transition from a rural to a western lifestyle. Inflammation is frequently associated with metabolic syndrome and CAD. This study evaluated markers of inflammation in black CAD patients, some of whom had metabolic syndrome. Methods: Metabolic syndrome was defined according to International Diabetes Federation criteria. Inflammatory markers leptin, adiponectin, and high-sensitivity C-reactive protein (hs-CRP) were measured in 40 patients and 20 control subjects. Results: Metabolic syndrome was present in 23 patients and absent in 17 patients. Leptin was the only significantly higher marker in patients with metabolic syndrome compared to patients without metabolic syndrome (P < 0.01). Leptin was higher in women than men (P < 0.01) and higher in both genders with metabolic syndrome (P < 0.03 and P < 0.04, respectively). Leptin levels rose significantly with increasing metabolic syndrome criteria (P < 0.05). hs-CRP concentrations were elevated in both patient groups. Positive correlations were found between leptin and body mass index (BMI) (r = 0.7107; P < 0.0001), waist circumference (WC) (r = 0.4981; P < 0.002), and hs-CRP (r = 0.3886; P < 0.02). Conclusions: Leptin differentiated between CAD patients with and without metabolic syndrome and determined metabolic syndrome status in women and men. Leptin was the only marker that increased with additional metabolic syndrome criteria. Elevated hs-CRP concentrations may indicate a low-grade inflammatory state in CAD patients. Association of leptin with BMI, WC, and hs-CRP revealed a close link with metabolic syndrome, obesity, and inflammation in urban black South African CAD patients

Summary

South African black