Antibacterial and anti-virulence potential of plant phenolic compounds against Vibrio parahaemolyticus.

Background: Vibrio parahaemolyticus is a pathogenic bacterium that affects shrimp aquaculture; its infection can lead to severe production losses of up to 90%. On the other hand, plant phenolic compounds have emerged as a promising alternative to combat bacterial infections. The antibacterial and anti-virulence activity of the plant phenolic compounds quercetin, morin, vanillic acid, and protocatechuic acid against two strains of V. parahaemolyticus (Vp124 and Vp320) was evaluated. Methods: The broth microdilution test was carried out to determine phenolic compounds' antibacterial activity. Moreover, the biofilm-forming ability of V. parahaemolyticus strains in the presence of phenolic compounds was determined by total biomass staining assay using the cationic dye crystal violet. The semisolid agar displacement technique was used to observe the effect of phenolic compounds on the swimming-like motility of V. parahaemolyticus. Results: Results showed that phenolic compounds inhibited both strains effectively, with minimum inhibitory concentrations (MICs) ranging from 0.8 to 35.03 mM. Furthermore, at 0.125 - 0.5 × MIC of phenolic compounds, V. parahaemolyticus biofilms biomass was reduced by 63.22 - 92.68%. Also, quercetin and morin inhibited the motility of both strains by 15.86 - 23.64% (Vp124) and 24.28 - 40.71% (Vp320). Conclusions: The results suggest that quercetin, morin, vanillic, and protocatechuic acids may be potential agents for controlling V. parahaemolyticus.

Co-segregation analysis and mapping of the anthracnose Co-10 and angular leaf spot Phg-ON disease-resistance genes in the common bean cultivar Ouro Negro.

Anthracnose (ANT) and angular leaf spot (ALS) are devastating diseases of common bean (Phaseolus vulgaris L.). Ouro Negro is a highly productive common bean cultivar, which contains the Co-10 and Phg-ON genes for resistance to ANT and ALS, respectively. In this study, we performed a genetic co-segregation analysis of resistance to ANT and ALS using an F2 population from the Rudá × Ouro Negro cross and the F2:3 families from the AND 277 × Ouro Negro cross. Ouro Negro is resistant to races 7 and 73 of the ANT and race 63-39 of the ALS pathogens. Conversely, cultivars AND 277 and Rudá are susceptible to races 7 and 73 of ANT, respectively. Both cultivars are susceptible to race 63-39 of ALS. Co-segregation analysis revealed that Co-10 and Phg-ON were inherited together, conferring resistance to races 7 and 73 of ANT and race 63-39 of ALS. The Co-10 and Phg-ON genes were co-segregated and were tightly linked at a distance of 0.0 cM on chromosome Pv04. The molecular marker g2303 was linked to Co-10 and Phg-ON at a distance of 0.0 cM. Because of their physical linkage in a cis configuration, the Co-10 and Phg-ON resistance alleles are inherited together and can be monitored with great efficiency using g2303. The close linkage between the Co-10 and Phg-ON genes and prior evidence are consistent with the existence of a resistance gene cluster at one end of chromosome Pv04, which also contains the Co-3 locus and ANT resistance quantitative trait loci. These results will be very useful for breeding programs aimed at developing bean cultivars with ANT and ALS resistance using marker-assisted selection.

Linkage mapping of the Phg-1 and Co-1(4) genes for resistance to angular leaf spot and anthracnose in the common bean cultivar AND 277.

The Andean common bean AND 277 has the Co-1(4) and the Phg-1 alleles that confer resistance to 21 and eight races, respectively, of the anthracnose (ANT) and angular leaf spot (ALS) pathogens. Because of its broad resistance spectrum, Co-1(4) is one of the main genes used in ANT resistance breeding. Additionally, Phg-1 is used for resistance to ALS. In this study, we elucidate the inheritance of the resistance of AND 277 to both pathogens using F(2) populations from the AND 277 × Rudá and AND 277 × Ouro Negro crosses and F(2:3) families from the AND 277 × Ouro Negro cross. Rudá and Ouro Negro are susceptible to all of the above races of both pathogens. Co-segregation analysis revealed that a single dominant gene in AND 277 confers resistance to races 65, 73, and 2047 of the ANT and to race 63-23 of the ALS pathogens. Co-1(4) and Phg-1 are tightly linked (0.0 cM) on linkage group Pv01. Through synteny mapping between common bean and soybean we also identified two new molecular markers, CV542014(450) and TGA1.1(570), tagging the Co-1(4) and Phg-1 loci. These markers are linked at 0.7 and 1.3 cM, respectively, from the Co-1(4) /Phg-1 locus in coupling phase. The analysis of allele segregation in the BAT 93/Jalo EEP558 and California Dark Red Kidney/Yolano recombinant populations revealed that CV542014(450) and TGA1.1(570) segregated in the expected 1:1 ratio. Due to the physical linkage in cis configuration, Co-1(4) and Phg-1 are inherited together and can be monitored indirectly with the CV542014(450) and TGA1.1(570) markers. These results illustrate the rapid discovery of new markers through synteny mapping. These markers will reduce the time and costs associated with the pyramiding of these two disease resistance genes.

[Limitation of myocardial expansion in late thrombolysis evaluated by two-dimensional echocardiography]. / Limitación de la expansión miocárdica con trombolisis tardía evaluada por ecocardiografía bidimensional.

Myocardial expansion in acute myocardial infarction (AMI) is present in about 45% of the patients within the first 72 hours. This is associated with ventricular aneurysm formation, myocardial rupture, heart failure and early death. Experimental studies in animals with AMI have used late reperfusion to decrease the incidence of expansion with success. The present is a prospective, longitudinal, open and randomized study in 21 patients with anterior AMI, to evaluate if the late reperfusion (6 to 12 hours) can decrease the incidence of myocardial expansion graded quantitatively with bidimensional echocardiography. Two groups were made: group A (n = 12) who received thrombolysis with streptokinase 1.5 mill. IU plus oral aspirin 150 mg OD (n = 9). Both groups had the same characteristics of AMI and functional class of Killip and Kimball (I-II class). Intrahospital treatment was given freely in both groups. The expansion was evaluated with bidimensional echocardiography used Jugdutt's method. In group A, expansion was present in 25% of the cases, while in group B was 66.6% (p < 0.0005). The distortion area, distortion peak, septal thickness and large asynergic segment were more sensitive parameters to identify myocardial expansion. Our results are similar to some experimental studies. We conclude that late thrombolysis can be useful in decreasing the incidence of myocardial expansion. Bidimensional echocardiography is a useful, fast and safe method to identify myocardial expansion.

[Isolation of Vibrio cholerae non 01 from sewage in Argentina]. / Aislamiento en Argentina de Vibrio cholerae no 01 en líquidos cloacales.

The Vibrio cholerae non 01 closely related to the classic choleric vibrio epidemic has acquired worldwide importance during the last decade, with outbreaks of diarrheas, septicemia and other disorders in humans and animals. Contaminated food and water and also liquids from sewers offer important steps in the transmission chain. Its isolation in the Atlantic and Pacific coast has led us to investigate its presence in our country, using sewage for the first study. We isolated for the first time in Argentina 27 strains of Vibrio cholerae non 01 from samples taken in the district of Berisso which discharges its waters into the River Plate.

Inheritance of resistance to bacterial blight in common bean.

Inheritance of resistance to common bacterial blight in the trifoliate leaf, plant canopy, and pods was controlled by a single major gene. Additive followed by dominance effects were more important than epistatic interactions. Narrow-sense heritability values ranged from 0.18 to 0.87 for trifoliate leaf, from 0.26 to 0.76 for canopy, and from 0.11 to 0.36 for pods. Observed gains from selection for resistance were higher than expected gains. Implications of these results in breeding for resistance are discussed.

Aislamiento en Argentina de Vibrio cholerae no 01 en líquidos cloacales. / [Isolation of Vibrio cholerae non 01 from sewage in Argentina]

The Vibrio cholerae non 01 closely related to the classic choleric vibrio epidemic has acquired worldwide importance during the last decade, with outbreaks of diarrheas, septicemia and other disorders in humans and animals. Contaminated food and water and also liquids from sewers offer important steps in the transmission chain. Its isolation in the Atlantic and Pacific coast has led us to investigate its presence in our country, using sewage for the first study. We isolated for the first time in Argentina 27 strains of Vibrio cholerae non 01 from samples taken in the district of Berisso which discharges its waters into the River Plate.