No abstract

Profilin is highly prevalent in melon-allergic patients, and promptly inactivated by SGF, as expected for an allergen mainly linked to OAS.

Validation of a PCR test to detect hilA gene sequences of Salmonella spp. was performed in blood and faeces samples from typhoid fever and salmonellosis patients. Sensitivity (S), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) of the PCR in blood samples were performed by testing: 37 patients with clinical diagnosis of typhoid fever, 34 of them confirmed by isolation of S. Typhi from blood cultures; 35 patients infected with other pathogens corroborated by blood culture (Klebsiella pneumoniae, 9; Serratia marcescens, 5; Escherichia coli, 4; Pseudomonas aeruginosa, 9; Providencia alcalifaciens, 4 and Enterobacter cloacae, 4) and blood samples from 150 healthy volunteers. To evaluate S, SP, PPV and NPV of the PCR in faeces samples we studied: 34 patients with enteritis due Salmonella spp. (S. Typhimurium, 21; S. Enteritidis, 9; S. Choleraesuis, 3 and S. Agona, 1); faeces samples from 35 patients with enteric infection due to Shigella sonnei (8), Shigella flexneri (10), enteropathogenic E. coli (12), Aeromonas hydrophila (5) and faeces samples from 150 healthy volunteers. The S, SP, PPV and NPV of the PCR in blood samples were all 100 %. PCR detected three patients with clinical diagnosis of typhoid fever and negative blood cultures. In faeces samples, S was 97 %, SP 100 %, PPV 100 % and NPV 99 %. The lowest number of c.f.u. ml À1 detected by PCR in blood samples was 1310 1 and in faeces samples 4310 2 .

A multiplex real-time polymerase chain reaction procedure was developed to identify the most prevalent clinical isolates of Salmonella enterica subsp. enterica. Genes from the rfb , fliC , fljB , and viaB groups that encode the O , H , and Vi antigens were used to design 15 primer pairs and TaqMan probes specific for the genes rfbJ , wzx , fliC , fljB , wcdB , the sdf-l sequence , and invA, which was used as an internal amplification control. The primers and probes were variously combined into six sets. The first round of reactions used two of these sets to detect Salmonella O:4 , O:9 , O:7 , O:8 , and O:3 ,10 serogroups. Once the serogroups were identified , the results of a second round of reactions that used primers and probes for the flagellar antigen l genes , 1 ,2; e ,h; g ,m; d; e ,n ,x; and z 10 , and the Vi gene were used to identify individual serovars. The procedure was standardized using 18 Salmonella reference strains and other enterobacteria. The procedure's reliability and sensitivity was evaluated using 267 randomly chosen serotyped Salmonella clinical isolates. The procedure had a sensitivity of 95.5% and was 100% specific. Thus , our technique is a quick , sensitive, reliable , and specific means of identifying S. enterica serovars and can be used in conjunction with traditional serotyping. Other primer and probe combinations could be used to increase the number of identifiable serovars. (J Mol Diagn 2010, 12:220 -225;

No abstract

Background: The present study aims to perform an epidemiological and molecular characterization of Blastocystis infection in a child population attending daycare centers of Medellín, Colombia. Methods: A total of 265 children aged 0–5 years were enrolled in five children’s centers in urban sectors of Medellín, northwestern Colombia. Stool samples were taken to identify intestinal parasites by direct examination, Ritchie–Frick concentration, and molecular identification of Blastocystis by conventional PCR and subtype (ST) identification by PCR barcoding with subsequent phylogenetic reconstruction. Kappa index was calculated to evaluate the agreement between microscopy and PCR for the diagnosis of Blastocystis. Results: The prevalence of intestinal protozoa was 36.6% (97/265), with Blastocystis as the most frequent parasitic protozoan at 15.8% (42/265), followed by Giardia intestinalis at 15.5% (41/265) and Endolimax nana at 15.1% (40/265). The prevalence of Blastocystis by PCR was 53.2% (141/265), the subtypes identified were ST3 at 30.5% (18/59), ST2 at 23.7% (14/59), ST1 at 20.3% (12/59), and with less frequency, ST4 at 5.1% (3/59), ST6 at 1.7% (1/59) and ST16 at 15.3% (9/59) allele 162. Conclusion: This study provides the first genetic characterization of Blastocystis subtypes circulating in a population of Medellín, Colombia, and also updates the epidemiology of Blastocystis subtypes in the world with the first identification of ST16 in humans.

Intestinal parasitosis (IP) is a public health problem in developing countries affecting one fourth of the global population. IP are common studied in children, neglecting the adults that are also at high risk and source of transmission. A screening study was performed with a convenience sample in three Colombian regions: Guachené (Cauca), Quibdó (Chocó), and Urabá (Antioquia). Feces samples from 284 volunteers (older than 18 years old) were tested by microscopy to identify parasite ova and cysts. The IP frequency was 14.5%, and 52.1% were males. 63.2% of the parasitized patients exhibited diarrhea, and/or abdominal pain with significant association. 39.5% had single parasitic infection and 60.5% had multiple parasites: Blastocystis hominis (63.9%), Entamoeba hystolitica/dispar (39.4%), Endolimax nana (33.3%), Ascaris lumbricoides (22.2%), Giardia lamblia (19.4%), Entamoeba coli (13.9%), Trichuris trichiura (11.1%), hookworm species (11.1%), Strongyloides stercolaris (5.6%), and Iodamoeba butschlii (2.8%). A multivariate approach was used to determine predictor factors for IP: male gender, rainwater as drinking source, and feces disposal different to toilet, latrine or septic tank were positively associated with infection. This study evidences that adult population, not only children from vulnerable areas of Colombia, must have to include as a risk for intestinal parasitism.

Brucella canis , a Gram-negative coccobacilli belonging to the genus Brucellae , is a pathogenic bacterium that can produce infections in dogs and humans. Multiple studies have been carried out to develop diagnostic techniques to detect all zoonotic Brucellae . Diagnosis of Brucella canis infection is challenging due to the lack of highly specific and sensitive diagnostic assays. This work was divided in two phases: in the first one, were identified antigenic proteins in B. canis that could potentially be used for serological diagnosis of brucellosis. Human sera positive for canine brucellosis infection was used to recognize immunoreactive proteins that were then identified by performing 2D-GEL and immunoblot assays. These spots were analyzed using MALDI TOF MS and predicted proteins were identified. Of the 35 protein spots analyzed, 14 proteins were identified and subsequently characterized using bioinformatics, two of this were selected for the next phase. In the second phase, we developed and validated an indirect enzyme-linked immunosorbent assays using those recombinant proteins: inosine 5′ phosphate dehydrogenase, pyruvate dehydrogenase E1 subunit beta (PdhB) and elongation factor Tu (Tuf). These genes were PCR-amplified from genomic DNA of B. canis strain Oliveri, cloned, and expressed in Escherichia coli . Recombinant proteins were purified by metal affinity chromatography, and used as antigens in indirect ELISA. Serum samples from healthy and B. canis -infected humans and dogs were used to evaluate the performance of indirect ELISAs. Our results suggest that PdhB and Tuf proteins could be used as antigens for serologic detection of B. canis infection in humans, but not in dogs. The use of recombinant antigens in iELISA assays to detect B. canis -specific antibodies in human serum could be a valuable tool to improve diagnosis of human brucellosis caused by B. canis .