ABSTRACT
BACKGROUND: Chagas disease (CD) is a chronic parasitic disease caused by Trypanosoma cruzi and is endemic to continental Latin America. In Spain, the main transmission route is congenital. We aimed to assess adherence to regional recommendations of universal screening for CD during pregnancy in Latin American women in the province of Alicante from 2014 to 2018. METHODOLOGY/PRINCIPAL FINDINGS: Retrospective quality study using two data sources: 1) delivery records of Latin American women that gave birth in the 10 public hospitals of Alicante between January 2014 and December 2018; and 2) records of Chagas serologies carried out in those centers between May 2013 and December 2018. There were 3026 deliveries in Latin American women during the study period; 1178 (38.9%) underwent CD serology. Screening adherence ranged from 17.2% to 59.3% in the different health departments and was higher in Bolivian women (48.3%). Twenty-six deliveries (2.2%) had a positive screening; CD was confirmed in 23 (2%) deliveries of 21 women. Bolivians had the highest seroprevalence (21/112; 18.7%), followed by Colombians (1/333; 0.3%) and Ecuadorians (1/348; 0.3%). Of 21 CD-positive women (19 Bolivians, 1 Colombian, 1 Ecuadorian), infection was already known in 12 (57.1%), and 9 (42.9%) had already been treated. Only 1 of the 12 untreated women (8.3%) was treated postpartum. Follow-up started in 20 of the 23 (87.0%) neonates but was completed only in 11 (47.8%); no cases of congenital transmission were detected. Among the 1848 unscreened deliveries, we estimate 43 undiagnosed cases of CD and 1 to 2 undetected cases of congenital transmission. CONCLUSIONS/SIGNIFICANCE: Adherence to recommendations of systematic screening for CD in Latin American pregnant women in Alicante can be improved. Strategies to strengthen treatment of postpartum women and monitoring of exposed newborns are needed. Currently, there may be undetected cases of congenital transmission in our province.
Subject(s)
Chagas Disease/diagnosis , Chagas Disease/prevention & control , Guideline Adherence/statistics & numerical data , Infectious Disease Transmission, Vertical/statistics & numerical data , Mass Screening/methods , Central America/epidemiology , Chagas Disease/epidemiology , Cross-Sectional Studies , Female , Humans , Pregnancy , Pregnancy Complications, Parasitic/epidemiology , Retrospective Studies , Seroepidemiologic Studies , South America/epidemiology , Trypanosoma cruzi/isolation & purificationABSTRACT
PKCepsilon is a member of the group of novel PKCs that contain a C2 domain located in their N-terminal region. On the basis of recent structural studies, a series of mutants were prepared to increase our knowledge of the mechanism of the phospholipid binding site of this domain. The results revealed that this domain preferentially binds to phosphatidic acid- and phosphatidylserine-containing vesicles. Although the increase in affinity was linear in the case of phosphatidic acid, it became exponential when the vesicles contained increasing concentrations of phosphatidylserine. Site-directed mutagenesis studies showed that residues W23, R26, and R32 located in loop 1 and I89 and Y91 located in loop 3 are of critical importance when the binding is performed with phosphatidic acid-containing vesicles. Furthermore, when the same mutants were assayed with phosphatidylserine-containing vesicles, no binding was observed in any case, reflecting the smaller affinity of the C2 domain for phosphatidylserine-containing vesicles. A study of the ionic nature of the membrane interaction suggested that it is mainly driven by electrostatic interactions that are disrupted by very low salt concentrations. Differential scanning calorimetry experiments performed to ascertain whether this interaction affected the transition phase of the phosphatidic acid demonstrated that increasing concentrations of the protein lead to changes in the transition, with more than one peak appearing at lower temperatures, which suggests a weak interaction focused on the polar headgroup of the phospholids. In conclusion, a different membrane-binding mode from those previously described in other C2 domains has been found and is seemingly based on electrostatic, interfacial, and hydrophobic interactions without the participation of Ca(2+) ions.
Subject(s)
Membrane Proteins/chemistry , Protein Kinase C/chemistry , Animals , Isoenzymes/chemistry , Isoenzymes/genetics , Isoenzymes/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Models, Molecular , Mutagenesis, Site-Directed , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Phosphatidic Acids/chemistry , Phosphatidylserines/chemistry , Phospholipids/chemistry , Protein Binding/genetics , Protein Kinase C/genetics , Protein Kinase C/metabolism , Protein Kinase C-epsilon , Protein Structure, Secondary/genetics , Protein Structure, Tertiary/genetics , RatsABSTRACT
In view of the interest shown in phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P(2)) as a second messenger, we studied the activation of protein kinase Calpha by this phosphoinositide. By using two double mutants from two different sites located in the C2 domain of protein kinase Calpha, we have determined and characterized the PtdIns(4,5)P(2)-binding site in the protein, which was found to be important for its activation. Thus, there are two distinct sites in the C2 domain: the first, the lysine-rich cluster located in the beta3- and beta4-sheets and which activates the enzyme through direct binding of PtdIns(4,5)P(2); and the second, the already well described site formed by the Ca(2+)-binding region, which also binds phosphatidylserine and a result of which the enzyme is activated. The results obtained in this work point to a sequential activation model, in which protein kinase Calpha needs Ca(2+) before the PtdIns(4,5)P(2)-dependent activation of the enzyme can occur.
