Whole-genome sequencing of Staphylococcus epidermidis bloodstream isolates from a prospective clinical trial reveals that complicated bacteraemia is caused by a limited number of closely related sequence types.

OBJECTIVES: The significance of isolating Staphylococus epidermidis from a blood culture is highly heterogeneous, ranging from contamination to an indication of a serious infection. Herein we sought to determine whether there is a relationship between S. epidermidis genotype and clinical severity of bacteraemia. METHODS: S. epidermidis bacteraemias from a prospective, multicentre trial at 15 centres in the United States and one in Spain were classified as simple (including possible contamination), uncomplicated, and complicated. Whole-genome sequencing (WGS) was performed on 161 S. epidermidis isolates, and clinical outcomes were correlated with genotypic information. RESULTS: A total of 49 S. epidermidis sequence types (STs) were identified. Although strains of all 49 STs were isolated from patients with either simple or uncomplicated infection, all strains causing complicated infections were derived from five STs: ST2, ST5, ST7, ST16, and ST32. ST2 and ST5 isolates were significantly more likely to cause uncomplicated and complicated bloodstream infections compared to simple bacteraemia (odds ratio 2.0, 95%CI 1.1-3.9, p 0.04). By multivariate regression analysis, having an ST2 or ST5 S. epidermidis bacteraemia was an independent predictor of complicated bloodstream infection (odds ratio 3.7, 95%CI 1.2-11.0, p 0.02). ST2/ST5 strains carried larger numbers of antimicrobial resistance determinants compared to non-ST2/ST5 isolates (6.34 ± 1.5 versus 4.4 ± 2.5, p < 0.001). CONCLUSION: S. epidermidis bacteraemia was caused by a genetically heterogeneous group of organisms, but only a limited number of STs-particularly multidrug-resistant ST2 and ST5 strains-caused complicated infections.

Perceived fatigability and metabolic and energetic responses to 6-minute walk test in older women.

OBJECTIVE: To determine the relationship between perceived fatigability and oxygen consumption, carbon dioxide production, respiratory exchange ratio and the energy cost of walking in older women. DESIGN: Observational, cross-sectional study. PARTICIPANTS: Forty-eight community-dwelling older women were recruited from senior centres in Natal, Rio Grande do Norte, Brazil. MAIN OUTCOME MEASURES: Participants were evaluated in two different sessions. In the first session, sociodemographic and clinical factors were assessed and accelerometers were delivered. In the second session, the 6-minute walking test (6MWT) was performed and expired gases were analysed. Self-reported levels of fatigue were evaluated on a numerical scale from 1 ('extremely energetic') to 7 ('extremely tired'). Severity scores for perceived and performance fatigability were calculated as the ratio of change in performance and fatigue, respectively, with walking distance. The O2 cost of walking was based on the oxygen consumption rate and the 6MWT walking speed. RESULTS: No correlation was found between the severity of perceived fatigability and metabolic measures. However, the severity of perceived fatigability was significantly correlated with greater O2 cost (r=0.579, P<0.01), physical activity (r=-0.654, P<0.01), walking distance (r=-0.712, P<0.01) and severity of performance fatigability (r=0.690, P<0.01). CONCLUSION: Perceived fatigability was not directly associated with metabolic measures; however, greater severity of perceived fatigability was associated with an increase in the O2 cost of walking. Important relationships were also found between greater severity of perceived fatigability and poor functional fitness, high level of energy expenditure and lower level of physical activity.

Insulin secretion, insulin sensitivity, and hepatic insulin extraction in first-degree relatives of type 2 diabetic patients.

To identify early metabolic abnormalities in type 2 diabetes mellitus, we measured insulin secretion, sensitivity to insulin, and hepatic insulin extraction in 48 healthy normal glucose-tolerant Brazilians, first-degree relatives of type 2 diabetic patients (FH+). Each individual was matched for sex, age, weight, and body fat distribution with a person without history of type 2 diabetes (FH-). Both groups were submitted to a hyperglycemic clamp procedure (180 mg/dl). Insulin release was evaluated in its two phases. The first was calculated as the sum of plasma insulin at 2.5, 5.0, 7.5, and 10.0 min after the beginning of glucose infusion, and the second as the mean plasma insulin level in the third hour of the clamp procedure. Insulin sensitivity index (ISI) was the mean glucose infusion rate in the third hour of the clamp experiment divided by the mean plasma insulin concentration during the same period of time. Hepatic insulin extraction was determined under fasting conditions and in the third hour of the clamp procedure as the ratio between C-peptide and plasma insulin levels. FH+ individuals did not differ from FH- individuals in terms of the following parameters [median (range)]: a) first-phase insulin secretion, 174 (116-221) vs 207 (108-277) microU/ml, b) second-phase insulin secretion, 64 (41-86) vs 53 (37-83) microU/ml, and c) ISI, 14.8 (9.0-20.8) vs 16.8 (9.0-27.0) mg kg-1 min-1/ microU ml-1. Hepatic insulin extraction in FH+ subjects was similar to that of FH- ones at basal conditions (median, 0.27 vs 0.27 ng/microU) and during glucose infusion (0.15 vs 0.15 ng/ micro U). Normal glucose-tolerant Brazilian FH+ individuals well-matched with FH- ones did not show defects of insulin secretion, insulin sensitivity, or hepatic insulin extraction as tested by hyperglycemic clamp procedures.

Insulin secretion, insulin sensitivity, and hepatic insulin extraction in first-degree relatives of type 2 diabetic patients

To identify early metabolic abnormalities in type 2 diabetes mellitus, we measured insulin secretion, sensitivity to insulin, and hepatic insulin extraction in 48 healthy normal glucose-tolerant Brazilians, first-degree relatives of type 2 diabetic patients (FH+). Each individual was matched for sex, age, weight, and body fat distribution with a person without history of type 2 diabetes (FH-). Both groups were submitted to a hyperglycemic clamp procedure (180 mg/dl). Insulin release was evaluated in its two phases. The first was calculated as the sum of plasma insulin at 2.5, 5.0, 7.5, and 10.0 min after the beginning of glucose infusion, and the second as the mean plasma insulin level in the third hour of the clamp procedure. Insulin sensitivity index (ISI) was the mean glucose infusion rate in the third hour of the clamp experiment divided by the mean plasma insulin concentration during the same period of time. Hepatic insulin extraction was determined under fasting conditions and in the third hour of the clamp procedure as the ratio between C-peptide and plasma insulin levels. FH+ individuals did not differ from FH- individuals in terms of the following parameters [median (range)]: a) first-phase insulin secretion, 174 (116-221) vs 207 (108-277) æU/ml, b) second-phase insulin secretion, 64 (41-86) vs 53 (37-83) æU/ml, and c) ISI, 14.8 (9.0-20.8) vs 16.8 (9.0-27.0) mg kg-1 min-1/æU ml-1. Hepatic insulin extraction in FH+ subjects was similar to that of FH- ones at basal conditions (median, 0.27 vs 0.27 ng/æU) and during glucose infusion (0.15 vs 0.15 ng/æU). Normal glucose-tolerant Brazilian FH+ individuals well-matched with FH- ones did not show defects of insulin secretion, insulin sensitivity, or hepatic insulin extraction as tested by hyperglycemic clamp procedures

Brazilian individuals with impaired glucose tolerance are characterized by impaired insulin secretion.

BACKGROUND: To better understand the pathogenesis of type 2 diabetes mellitus, insulin secretion and insulin sensitivity (IS) were evaluated in white Brazilians with impaired glucose tolerance (IGT), using the oral glucose tolerance test (OGTT) and the hyperglycemic clamp technique. METHODS: Twenty-five IGT subjects were individually matched with normal glucose-tolerant (NGT) subjects for demographic characteristics. At first, they were submitted to the OGTT and plasma glucose and insulin were measured. Of the 25 pairs, 20 could participate in the hyperglycemic clamp procedures, at a second visit. All participants had their plasma glucose levels equally increased to 180 mg/dl; this was maintained for three hours by variable glucose infusion. During the procedure, plasma glucose and insulin were measured at established intervals. RESULTS: In the postabsorptive state, the IGT subjects presented higher levels of plasma glucose, blood HbA1, and serum triglycerides, but similar plasma insulin levels. After the oral glucose load, early and total insulin release, in relation to glucose levels, were respectively, 43 and 67% lower in the IGT individuals. The index of whole-body IS was increased in the IGT individuals (4.36 +/- 1.71 vs 3.61 +/- 1.28 mg(-1). micro U(-1).100.ml2; p<0.05). By the hyperglycemic clamp technique first- (82 +/- 26 vs 215 +/- 88 micro U/ml; p<0.001) and second- (36 +/- 19 vs 73 +/- 44 micro U/ml; p<0.05) phases of insulin secretion was decreased in the IGT individuals, especially the first one. However, the groups did not differ in relation to the IS: IGT=13.52 +/- 7.27 and NGT=9.96 +/- 6.70 mg.ml/kg. micro U.min(-1); p > 0.05. Functional relationship of IS (y) on first-phase insulin release (x) showed a smaller (p<0.05) regression coefficient for the IGT group. CONCLUSION: Brazilians with IGT well-matched with NGT ones were characterized by impaired first- and second-phase insulin secretion (mainly the former), while defects in IS were not evident.

Rattlesnake bite complications in 19 children.

The Western diamondback rattlesnake, Crotalus atrox, is responsible for the majority of snakebites in Sonora, Mexico. We report 19 cases of children who were attacked by these snakes. Most of the rattlesnake attacks occurred in rural areas during the summer. The children's ages ranged from one to 15 years. The lower extremities, especially the legs, were most often bitten. The signs and symptoms presented by these patients included: pain, edema, limitation of motion, ecchymosis, bleeding and necrosis in the area of the bite, epistaxis, hematuria, and vomiting. Hospital treatment included: parenteral electrolyte solutions, antivenom serum, antibiotics, tetanus toxoid, blood transfusions, hydrocortisone, heparin, and peritoneal dialysis. In one case a fasciotomy was necessary. The observed complications on envenomations included: hemolysis, local necrosis, coagulation disorders, paresthesia, somnolence, and acute renal failure. One death occurred from disseminated intravascular coagulation.