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1.
Bull Entomol Res ; 107(1): 32-38, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27765076

ABSTRACT

Interspecific interactions between two larval parasitoids of Tuta absoluta (Meyrick) with partially overlapping host niches were studied: the idiobiont ectoparasitoid Dineulophus phthorimaeae De Santis, and the koinobiont endoparasitoid Pseudapanteles dignus (Muesebeck). T. absoluta is an important pest of tomato crops worldwide, and its management could be improved by understanding the competitive interactions and potential coexistence between these two parasitoids. Firstly, a 15-min fixed time laboratory test evaluated the host-searching ability of adult D. phthorimaeae and P. dignus wasps on T. absoluta larvae. Secondly, D. phthorimaeae host discrimination against endoparasitized and non-endoparasitized hosts by P. dignus, at different adult female ages, was experimentally examined. D. phthorimaeae wasps spent significantly more time in general searching in the presence of its competitor than in its absence, but, parasitism was only effective by P. dignus. Older D. phthorimaeae wasps discriminated significantly less than young wasps between T. absoluta larvae parasitized and unparasitized by P. dignus, and an interaction took place by non-concurrent host-feeding. Intra-guild predation of P. dignus larvae by D. phthorimaeae female feeding behaviour might have a minor effect in this system. Results are discussed in the context of literature supporting diverse evidence of coexistence in other parasitoid-host systems, with implications for T. absoluta biological control.


Subject(s)
Moths/parasitology , Pest Control, Biological , Wasps/physiology , Animals , Female , Larva/growth & development , Larva/parasitology , Life History Traits , Moths/growth & development
2.
Neotrop Entomol ; 40(3): 412-4, 2011.
Article in English | MEDLINE | ID: mdl-21710041

ABSTRACT

We report the first record of Neochrysocharis formosa (Westwood) parasitizing larvae of the tomato moth, Tuta absoluta (Meyrick), in tomato crops in Northern Buenos Aires Province, Argentina. Tomato moth larvae were sampled during four consecutive growing cycles, between 2003 and 2005, in 10 sites. Neochrysocharis formosa was present only in organic outdoor and protected crops, and predominantly during the late season. Parasitism rates varied from 1.5% to 5%. The finding of this species is a new record for Argentina and South America, and T. absoluta is a new host record.


Subject(s)
Hymenoptera/physiology , Moths/parasitology , Solanum lycopersicum/parasitology , Animals , Argentina
3.
Trans R Soc Trop Med Hyg ; 99(9): 669-74, 2005 Sep.
Article in English | MEDLINE | ID: mdl-15975612

ABSTRACT

The relationship between enteropathogens and severe diarrhoea in the Brazilian Amazon is poorly understood. In 1998, outbreaks of acute diarrhoea clinically diagnosed as cholera occurred in two small villages localized far from the main cholera route in the Brazilian rainforest. PCR was performed on some enteropathogens and heat-labile (LT) and/or heat-stable (STh) toxin genes, the virulence determinants of enterotoxigenic Escherichia coli (ETEC), were detected. Further characterization of ETEC isolates revealed the presence of two clones, one from each outbreak. One presenting serotype O167:H5 harboured LT-I and STh toxin genes and expressed the CS5CS6 colonization factor. The other, a non-typeable serotype, was positive for the LT-I gene and expressed the CS7 colonization factor. The current study demonstrates the importance of molecular diagnosis in regions such as the Amazon basin, where the enormous distances and local support conditions make standard laboratory diagnosis difficult. Here we also show that the mis-identified cholera cases were in fact associated with ETEC strains. This is the first report of ETEC, molecularly characterized as the aetiological agent of severe diarrhoea in children and adults in the Brazilian Amazon Rainforest.


Subject(s)
Cholera/microbiology , Diarrhea/microbiology , Disease Outbreaks , Escherichia coli Infections , Adolescent , Adult , Brazil/epidemiology , Child , Child, Preschool , Cholera/epidemiology , Diarrhea/epidemiology , Enterotoxins/analysis , Escherichia coli Infections/epidemiology , Escherichia coli Infections/genetics , Female , Humans , Male , Polymerase Chain Reaction
4.
Braz J Med Biol Res ; 31(4): 545-54, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9698808

ABSTRACT

An expression plasmid (pCFA-1) carrying the cfaB gene that codes for the enterotoxigenic Escherichia coli (ETEC) fimbrial adhesin colonization factor antigen I (CFA/I) subunit was constructed and used to transform a derivative of the attenuated Salmonella typhimurium aroA vaccine strain SL3261 carrying an F'lacIq. Treatment of the transformed strain with isopropyl-beta-D-thiogalactopyranoside (IPTG) resulted in elevated in vitro expression of the CFA/I subunit. Although flagellar function and lipopolysaccharide (LPS) synthesis were similar in both the parental and the recombinant strains, spleen colonization was reduced in the recombinant strain. All BALB/c mice parenterally inoculated with the recombinant strain developed significant anti-CFA/I and anti-LPS serum antibody titers (P < 0.05). Moreover, 2 of 5 mice orally inoculated with the engineered Salmonella strain developed anti-CFA/I intestinal IgA (P > 0.05) while 4/5 of the same mice developed anti-LPS IgA (P < 0.05). The results indicate that the vaccine strain elicited an antibody response against the bacterial host both after oral and intravenous immunization while the response against the CFA/I antigen was significant only after inoculation by the intravenous route.


Subject(s)
Antigens, Bacterial/immunology , Bacterial Proteins/immunology , Bacterial Vaccines/immunology , Diarrhea/prevention & control , Escherichia coli Infections/prevention & control , Fimbriae Proteins , Salmonella typhimurium/immunology , Animals , Antibody Formation/immunology , Diarrhea/immunology , Diarrhea/microbiology , Escherichia coli Vaccines , Mice , Mice, Inbred BALB C , Vaccines, Attenuated , Vaccines, Synthetic
5.
Microbiol Immunol ; 42(5): 341-6, 1998.
Article in English | MEDLINE | ID: mdl-9654365

ABSTRACT

A monoclonal antibody (MAb 84) raised against the dissociated CFA/I fimbriae of enterotoxigenic Escherichia coli was characterized with regard to antigen binding and epitope specificity. Enzyme-linked immunosorbent assay (ELISA) showed that MAb 84 had higher affinity to CFA/I subunits than to intact CFA/I fimbriae and recognized a Salmonella flagellin carrying an insert corresponding to amino acids 32 to 45 of the CFA/I subunit. Fine epitope mapping based on the Pepscan technique showed that the peptide 39TFESY43, derived from the sequence of the mature CFA/I subunit, was specifically recognized by MAb 84. The 39TFESY43 sequence is probably not accessible on the surface of the native CFA/I fimbriae since MAb 84 did not bind to intact fimbriae as evaluated in inhibition ELISA tests. Moreover, MAb 84 did not agglutinate fimbriated ETEC cells nor inhibit CFA/I-mediated hemagglutination or the adhesion to Caco-2 cells.


Subject(s)
Antibodies, Monoclonal/immunology , Bacterial Proteins/immunology , Epitopes/immunology , Escherichia coli/immunology , Fimbriae Proteins , Fimbriae, Bacterial/immunology , Animals , Antibodies, Monoclonal/biosynthesis , Bacterial Adhesion/immunology , Bacterial Outer Membrane Proteins/immunology , Caco-2 Cells/immunology , Cloning, Molecular , Epitope Mapping , Hemagglutination Inhibition Tests , Humans , Mice , Mice, Inbred BALB C
6.
Braz. j. med. biol. res ; 31(4): 545-54, Apr. 1998. ilus, tab, graf
Article in English | LILACS | ID: lil-212420

ABSTRACT

An expression plasmid (pCFA-1) carrying the cfaB gene that codes for the enterotoxigenic Escherichia coli (ETEC) fimbrial adhesin colonization factor antigen I(CFA/I) subunit was constructed and used to transform a derivative of the attenuated Salmonella typhimurium aroA vaccine strain SL3261 carrying an F'lacl(q). Treatment of the transformed strain with isopropyl-beta-D-thiogalactopyranoside (IPTG) resulted in elevated in vitro expression of the CFA/I subunit. Although flagellar function and lipopolysaccharide (LPS) synthesis were similar in both the parental and the recombinant strains, spleen colonization was reduced in the recombinant strain. AII BALB/c mice parenteally inoculated with the recombinant strain developed significant anti-CFA/I and anti-LPS serum antibody titers (P<0.05). Moreover, 2 of 5 mice orally inoculated with the engineered Salmonella strain developed anti-CFA/I intestinal IgA (P>0.05) while 4/5 of the same mice developed anti-LPS (P<0.05). The results indicate that the vaccine strain elicited an antibody response against the bacterial host both after oral and intravenous immunization while the response against the CFA/I antigen was significant only after inoculation by the intravenous route.


Subject(s)
Animals , Mice , Antigens, Bacterial/immunology , Bacterial Vaccines/immunology , Diarrhea , Escherichia coli Infections , Salmonella typhimurium/immunology , Antibody Formation/immunology , Bacterial Proteins , Diarrhea/immunology , Diarrhea/microbiology , Enterotoxins/biosynthesis , Mice, Inbred BALB C , Molecular Sequence Data , Plasmids/immunology , Vaccines, Attenuated , Vaccines, Synthetic
7.
Res Microbiol ; 148(3): 217-28, 1997.
Article in English | MEDLINE | ID: mdl-9765802

ABSTRACT

Oligonucleotides coding for linear epitopes of the fimbrial colonization factor antigen I (CFA/I) of enterotoxigenic Escherichia coli (ETEC) were cloned and expressed in a deleted form of the Salmonella muenchen flagellin fliC (H1-d) gene. Four synthetic oligonucleotide pairs coding for regions corresponding to amino acids 1 to 15 (region I), amino acids 11 to 25 (region II), amino acids 32 to 45 (region III) and amino acids 88 to 102 (region IV) were synthesized and cloned in the Salmonella flagellin-coding gene. All four hybrid flagellins were exported to the bacterial surface where they produced flagella, but only three constructs were fully motile. Sera recovered from mice immunized with intraperitoneal injections of purified flagella containing region II (FlaII) or region IV (FlaIV) showed high titres against dissociated solid-phase-bound CFA/I subunits. Hybrid flagellins containing region I (FlaI) or region III (FlaIII) elicited a weak immune response as measured in enzyme-linked immunosorbent assay (ELISA) with dissociated CFA/I subunits. None of the sera prepared with purified hybrid flagella were able to agglutinate or inhibit haemagglutination promoted by CFA/I-positive strains. Moreover, inhibition ELISA tests indicated that antisera directed against region I, II, III or IV cloned in flagellin were not able to recognize surface-exposed regions on the intact CFA/I fimbriae.


Subject(s)
Bacterial Proteins/immunology , Escherichia coli/immunology , Fimbriae Proteins , Fimbriae, Bacterial/immunology , Flagellin/immunology , Amino Acid Sequence , Animals , Bacterial Proteins/biosynthesis , Bacterial Proteins/chemistry , Base Sequence , Cloning, Molecular , Enzyme-Linked Immunosorbent Assay , Epitopes/biosynthesis , Epitopes/chemistry , Epitopes/immunology , Escherichia coli/genetics , Escherichia coli/pathogenicity , Flagellin/chemistry , Flagellin/genetics , Hemagglutination Inhibition Tests , Hemagglutination Tests , Mice , Molecular Sequence Data , Oligodeoxyribonucleotides , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Restriction Mapping , Salmonella/genetics
8.
Kokubyo Gakkai Zasshi ; 63(1): 122-30, 1996 Mar.
Article in Japanese | MEDLINE | ID: mdl-8725361

ABSTRACT

The expression patterns of type I, II and IX collagens in chondromyxoid tissue of salivary pleomorphic adenomas were examined by immunohistochemistry. In the early stage of cartilage development, type IX collagen was detected intracytoplasmically, mainly in the proliferating myoepithelial cells and not in the extracellular matrix. Proliferating myoepithelial cells did not show chondrocytic characteristics at this stage. Type I and II collagens were co-distributed in the extracellular matrix of myxoid tissue. In the chondroid tissue, variable immunostaining patterns of type I and II collagens were also observed. Some proliferating myoepithelial cells in myxoid and chondroid tissue were immunostained with anti-alpha-smooth muscle actin antibody indicating their myoepithelial origin. These results suggested that proliferating myoepithelial cells may be the origin of the chondroid tissue and the expression of type IX collagen in cartilaginous tissue precedes the expression of type I and II collagens.


Subject(s)
Adenoma, Pleomorphic/metabolism , Collagen/metabolism , Salivary Gland Neoplasms/metabolism , Adult , Aged , Cartilage/growth & development , Cartilage/metabolism , Epithelial Cells , Epithelium/metabolism , Female , Humans , Immunohistochemistry , Male , Middle Aged
9.
Pract Odontol ; 11(7): 19-21, 24-5, 27, 1990 Jul.
Article in Spanish | MEDLINE | ID: mdl-2132272

ABSTRACT

A prospective study of extra and intraoral biopsies diagnosed and processed at the School of Odontology of the Technological University of Mexico (UNITEC) in its various service units, within a two and a half year period covering from January 1986 to May 1988. Out of 12,456 patients, 73 biopsies and 7 exfoliative cytologies were performed, with 41 different lesions detected. The clinical features of the five conditions most frequently found in the study are emphasized and compared with findings reported in international literature regarding the same lesions.


Subject(s)
Mouth Diseases/epidemiology , Mouth Neoplasms/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Candidiasis, Oral/epidemiology , Child , Female , Fibroma/epidemiology , Hemangioma/epidemiology , Humans , Male , Mexico/epidemiology , Middle Aged , Papilloma/epidemiology , Retrospective Studies , Stomatitis/epidemiology
10.
Article in English | MEDLINE | ID: mdl-2576796

ABSTRACT

1. The major components of hepatic drug biotransformation system were identified in a Brazilian freshwater benthic fish. 2. Cytochrome P-450 difference spectra were obtained adding 0.02 mM phenazine ethosulphate and 2 mM ascorbate to microsomal suspensions. Basal levels of P-450 were high (0.9 nmol/mg of microsomal protein) and were not induced by 3-MC. 3. Microsomal NADPH-cytochrome C reductase activity was determined in presence of 1.3 x 10(-4) M NADPH, 3.3 x 10(-5) M cytochrome C, 1.0 x 10(-4) M EDTA, 66 micrograms of microsomal protein per ml in a 0.3 M Tris-HCl buffer, pH 8.6. Basal levels of NADPH-cytochrome C were 152.7 nmoles/min/mg of microsomal protein.


Subject(s)
Fishes/metabolism , Microsomes, Liver/metabolism , Water Pollutants, Chemical/metabolism , Water Pollutants/metabolism , Animals , Ascorbic Acid/pharmacology , Brazil , Cytochrome P-450 Enzyme System/analysis , Female , Hemoglobins/isolation & purification , Inactivation, Metabolic/physiology , Male , NADPH-Ferrihemoprotein Reductase/metabolism , Phenazines/pharmacology , Rats
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