Sonia Soto-Rodriguez | Centro de Investigación en Alimentación y Desarollo, A.C. (original) (raw)

Papers by Sonia Soto-Rodriguez

Aquaculture Research, 2020

Aquaculture is a rapidly developing economic activity that provides almost half the fish consumed... more Aquaculture is a rapidly developing economic activity that provides almost half the fish consumed by humans (FAO, 2018). Due to the rapid growth in aquaculture, there has been an increase in the demand of feed supplies for farmed species. Traditionally, FM is the main protein source for the formulation of aquaculture feeds, especially for carnivorous species. However, due to a global shortage of this ingredient, it has become a costly dietary macroelement. Therefore, there is a need to identify alternative protein sources to reduce the dependence on fishmeal (Tacon, Hasan, & Metian, 2011). Plants, such as soya bean meal, and animal by-products have the potential to be used to replace FM in diets for Lujannus gutattus. For instance, some dose-response studies of this species show that the expensive FM protein could be partially replaced by soya bean meal (up to 20% of the total protein source), pet grade poultry by-product meal (90%), feed grade poultry by-product meal (25%), tuna by-product meal (TBM) (30%) and meat and bone meal (35%) (Hernández

한국수산과학회 양식분과 학술대회, May 1, 2015

Current Microbiology, Sep 21, 2020

Acute hepatopancreatic necrosis disease (AHPND) is a severe disease affecting recently stocked cu... more Acute hepatopancreatic necrosis disease (AHPND) is a severe disease affecting recently stocked cultured shrimps. The disease is mainly caused by V. parahaemolyticus that harbors the pVA1 plasmid; this plasmid contains the pirA and pirB genes, which encode a delta-endotoxin. AHPND originated in China in 2009 and has since spread to several other Asian countries and recently to Latin America (2013). Many Asian strains have been sequenced, and their sequences are publicly accessible in scientific databases, but only four strains from Latin America have been reported. In this study, we analyzed nine pVA1-harboring V. parahaemolyticus sequences from strains isolated in Mexico along with the 38 previously available pVA1-harboring V. parahaemolyticus sequences and the reference strain RIMD 2210633. The studied sequences were clustered into three phylogenetic clades (Latin American, Malaysian, and Cosmopolitan) through pangenomic and phylogenomic analysis. The nucleotide sequence alignment of the pVA1 plasmids harbored by the Asian and Latin American strains confirmed that the main structural difference in the plasmid between the Asian and Latin American strains is the absence of the Tn3 transposon in the Asian strains; in addition, some deletions in the pirAB region were found in two of the Latin American strains. Our study represents the most robust and inclusive phylogenomic analysis of pVA1-harboring V. parahaemolyticus conducted to date and provides insight into the epidemiology of AHPND. In addition, this study highlights that disease diagnosis through the detection of the pirA and pirB genes is an inadequate approach due to the instability of these genes.

Aquaculture Research, Nov 15, 2021

Fish & Shellfish Immunology, Oct 1, 2022

Aquaculture International

Aquaculture, 2020

Juvenile C. viridis (5.26 ± 0.72 g) were intraperitoneally injected with three doses of Vibrio po... more Juvenile C. viridis (5.26 ± 0.72 g) were intraperitoneally injected with three doses of Vibrio ponticus (Vp) CAIM 1751 from 10 4 to 10 6 CFU/g, and histological analysis, haemolytic activity assessment and putative virulence genes identification were performed. The time of experimental challenge was 168 h. The virulence of Vp was dose-dependent. The mortality after 25 h post infection (p.i.) was 100% at 3.1 × 10 6 CFU/g and, 83% at 60 h p.i. at 2.9 × 10 5 CFU/g. The LC 50 was 2.9 × 10 5 CFU/g at 32 h p.i. Congestion and petechial haemorrhages in the ventral area were observed in the infected fish. Similar histological lesions were observed at the three doses as necrosis, congestion and bacterial masses in different organs and tissues. This is the first report where Vp caused in C. viridis pathological changes associated with an acute peritonitis that caused irreversible damage to the internal organs, except in the kidney. Greater severity was identified in the liver and pancreas of the organisms exposed to the higher dose and in the stomach, intestine and nervous system of the fish infected with the lower dose. The main virulence genes of Vp CAIM 1751 were auto inducers, toxins and iron acquisition, including three types of haemolysins and metalloproteases. Furthermore, this strain had a strong β-haemolytic reaction on erythrocytes of the Pacific white snook. The combined action of the proteases and haemolysins may be responsible for the vascular fragility allowing for the rupture of small vessels and haemorrhages in the tissues. This study contributes to our understanding of Vibrio ponticus as an emerging finfish aquaculture pathogen.

1 Departamento de Genética y Bioestadística, Facultad de Medicina Veterinaria y Zootecnia, Univer... more 1 Departamento de Genética y Bioestadística, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior, Coyoacán, CDMX, Mexico montaldo@unam.mx (Corresponding autor) 2 Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana, Unidad Xochimilco, Coyoacán, CDMX, Mexico 3 Departamento El Hombre y su Ambiente, Universidad Autónoma Metropolitana, Unidad Xochimilco, Coyoacán, CDMX, Mexico Maricultura del Pacífico, Mazatlán, Sinaloa, Mexico. 5 Centro de Investigación en Alimentación y Desarrollo, A.C. Unidad Mazatlán en Acuicultura y Manejo Ambiental, Mazatlán, Sinaloa, Mexico

Asian Fisheries Science, 2018

The objective of this paper is to present preliminary results regarding heritability, genetic lin... more The objective of this paper is to present preliminary results regarding heritability, genetic line differences and inbreeding effects for survival time in experimental challenges to acute hepatopancreatic necrosis disease (AHPND) in Penaeus vannamei Boone 1931. Here we present results of analyses conducted on data from a Resistance Line obtained from a merging of several Ecuadorian groups with a history of white-spot syndrome virus resistance, and a Growth Line with high genetic growth ability, obtained by selection in a Mexican hatchery. Family-identified animals from the two genetic lines and their crosses were inoculated by immersion in 2014, 2015 and 2016 using a Vibrio parahaemolyticus strain (M0904) AHPND+ obtained from a natural infection in Mexico. Heritabilities for survival time obtained using nested linear mixed models ranged from 9 to 18 %. Survival was greater for the Resistance Line compared to the Growth Line or the F 1 cross (P < 0.02). Our results point to the presence of additive genetic variation in both lines evaluated that may be exploited in breeding programmes to increase AHPND resistance.

Diseases of Aquatic Organisms, 2020

Vibrio parahaemolyticusstrains have been identified as the causative agent of acute hepatopancrea... more Vibrio parahaemolyticusstrains have been identified as the causative agent of acute hepatopancreas necrosis disease (VpAHPND+) in shrimp. In the present work, a highly virulent (M0904) and less virulent (M0607) strain ofVpAHPND+ were used in experimental infections ofPenaeus vannamei. Throughout the experiment, histopathological analyses were conducted on shrimp tissues, and samples from the bottom (B) and water column (WC) of each aquarium were taken to estimate bacterial growth. The first deaths of shrimp challenged withVpM0904 occurred 4 h post-infection (hpi), reached 50% mortality at 17 hpi, and showed more acute pathological progression associated with AHPND despite both strains having similar bacterial densities from 0-4 hpi. The first deaths of shrimp inoculated withVpM0607 occurred at 13 hpi, a difference of 9 h. These shrimps displayed reduction of reserve vacuoles in R and B cells of the hepatopancreas, and reached 50% mortality at 27 hpi. As bacterial growth in the WC an...

Pathogens, 2020

Vibrio parahaemolyticus (Vp) is the etiological agent of the acute hepatopancreatic necrosis dise... more Vibrio parahaemolyticus (Vp) is the etiological agent of the acute hepatopancreatic necrosis disease (AHPND) in Penaeus vannamei shrimp. Vp possesses a 63–70 kb conjugative plasmid that encodes the binary toxin PirAvp/PirBvp. The 250 kDa PirABvp complex was purified by affinity chromatography with galactose-sepharose 4B and on a stroma from glutaraldehyde-fixed rat erythrocytes column, as a heterotetramer of PirAvp and PirBvp subunits. In addition, recombinant pirB (rPirBvp) and pirA (rPirAvp) were obtained. The homogeneity of the purified protein was determined by SDS-PAGE analysis, and the yield of protein was 488 ng/100 μg of total protein of extracellular products. The PirABvp complex and the rPirBvp showed hemagglutinating activity toward rat erythrocytes. The rPirAvp showed no hemagglutinating capacity toward the animal red cells tested. Among different mono and disaccharides tested, only GalNH2 and GlcNH2 were able to inhibit hemagglutination of the PirABvp complex and the rP...

Aquaculture, 2020

al., Genetic (co)variation in resistance of Pacific white shrimp Litopenaeus vannamei to acute he... more al., Genetic (co)variation in resistance of Pacific white shrimp Litopenaeus vannamei to acute hepatopancreatic necrosis disease (AHPND) and white spot syndrome virus (WSSV) in challenge tests, aquaculture (2019),

Journal of Applied Phycology, 2019

Ag-based nanoparticles (NPs) were successfully produced through green synthesis using an aqueous ... more Ag-based nanoparticles (NPs) were successfully produced through green synthesis using an aqueous extract from the cultivated seaweed Ulva clathrata as the reducing and stabilizing agent. The biosynthesized NPs had spherical to polymorphic shapes with an average size of 9.5 nm. Microstructural and compositional studies revealed that these particles contained face-centred cubic crystallites of metallic Ag and AgCl. Characteristic peaks in the Fourier-transform infrared spectrum (FTIR) and Raman studies revealed the presence of functional bioactive metabolites from the seaweed extract, such as proteins, polysaccharides, and polyphenols, which are responsible for forming and stabilizing Ag/AgCl NPs. The biosynthesized Ag/AgCl NPs exhibited an important in vitro antibacterial effect against three Vibrio parahaemolyticus strains isolated from farmed shrimp affected with acute hepatopancreatic necrosis disease (AHPND) in northwestern Mexico. Litopenaeus vannamei shrimp were exposed for 7 days to feeds supplemented with Ag/AgCl NPs at 10, 100, 1000, or 10,000 ppm (Ag nominal dietary concentrations). Dietary NP supplement did not affect shrimp survival, growth, or feed conversion ratio, but high concentrations (1000 and 10,000 ppm) decreased the hepatosomatic index significantly. The short-term consumption of Ag/AgCl NPs produced a significant dosedependent bioaccumulation of Ag in the hepatopancreas and to a lesser extent in the cuticle, while bioaccumulation in the muscle was not significant. The depuration study confirmed a fast Ag assimilation in shrimp's hepatopancreas and showed a fast depuration rate in the hepatopancreas as well.

Diseases of Aquatic Organisms, 2019

To examine the pathogenicity of Vibrio strains, several doses of Vibrio harveyi (CAIM 1622 and CA... more To examine the pathogenicity of Vibrio strains, several doses of Vibrio harveyi (CAIM 1622 and CAIM 1508), Vibrio ponticus (CAIM 1751) and Vibrio anguillarum (CAIM 8) were used to challenge Pacific white snook Centropomus viridis Lockington, 1877 juveniles, and survival, gross signs and histological lesions were observed. Susceptibility of pathogenic vibrios CAIM 1508 and CAIM 1751 to antibiotics used in aquaculture was also evaluated. The growth ability of the tested strains was not related to their pathogenicity. One of the V. harveyi strains (CAIM 1508) was the most virulent, causing per-acute septicaemia in C. viridis even at a low dose (1.4 × 104 CFU g-1). Although the V. ponticus strain (CAIM 1751) was less virulent, this is the first report of it as a pathogen of white snook. Fish challenged with V. ponticus displayed external, generalized haemorrhaging. Necrosis of the digestive tract and intravascular haemosiderosis were the most remarkable histological lesions in fish challenged with both strains. Multifocal necrosis of the internal organs and bacterial masses was also observed. The lowest minimum inhibitory concentration of the pathogenic strains (CAIM 1508 and CAIM 1751) was calculated for enrofloxacin (20 and 10 µg ml-1, respectively), and both bacteria were resistant to amoxicillin, ampicillin and trimethoprim-sulfamethoxazole.

Asian Fisheries Science, 2018

Moribund whiteleg shrimp (Penaeus vannamei) affected by acute hepatopancreatic necrosis disease (... more Moribund whiteleg shrimp (Penaeus vannamei) affected by acute hepatopancreatic necrosis disease (AHPND) from farms in northwestern Mexico were sampled for pathological analysis. Bacterial isolates were molecularly identified as Vibrio parahaemolyticus (VP) by the presence of the tlh gene. The tdh-negative, trh-negative and tlh-positive VP strains were further characterized by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The VP pure strains were used in immersion challenges with shrimp, and farmed and challenged shrimp presented the same clinical and pathological signs: lethargy, empty gut, pale and aqueous hepatopancreas and expanded chromatophores. Using fresh mount, histological analysis and bacterial density count, three stages of AHNPD (initial, acute and terminal) were identified in the affected shrimp. Pathognomonic lesions indicated severe desquamation of tubular epithelial cells of the hepatopancreas. VP had different virulence and was dose dependent. VP strains showed wide tolerance to different environment conditions of temperature, salinity and pH, and pathogenic and non-pathogenic VP strains from Mexico had similar morphological and physiological characteristics but pathogenic VP strains were most sensitive to nalidixic acid and showed resistance to penicillin. Whole genomic sequence of 22 VP strains from Asia, Mexico and South America shows the presence of similar chromosomic pathogenic mechanisms, and comparative analysis by multilocus sequence analysis (MLSA) of seven genes clearly showed that most of the isolates are independent strains.

Diseases of Aquatic Organisms, 2018

Aeromonas dhakensis (Ad) CAIM 1873 growth was evaluated at different conditions and antibiotic su... more Aeromonas dhakensis (Ad) CAIM 1873 growth was evaluated at different conditions and antibiotic susceptibility. Mortality and histopathological damages in hybrid tilapia Oreochromis niloticus × O. mossambicus, and virulence factors caused by Ad bacterial cells and extracellular products (ECPs) were evaluated, and the whole genome was obtained. Ad grew between 0.0 and 5.5% NaCl at a pH of between 4 and 10 and from 4 to 37°C. The lowest minimum inhibitory concentration was found for enrofloxacin (< 5 µg ml −1), and bacteria were resistant to erythromycin, amoxicillin and ampicillin. Ad bacterial cells (1.86 × 10 5 cells g −1) and ECPs (0.462 µg protein fish −1) were highly virulent to challenged hybrid tilapia and caused over 80% mortality at 24 h. The primary clinical sign caused was haemorrhage, and damage was most marked in the spleen, liver, kidney and brain of fish challenged with bacterial cells. To our knowledge, this is the first report that Ad causes pyknotic and karyorrhectic nuclei of erythrocytes in the internal organs of hybrid tilapia, which was the most striking histopathological observation. The virulence of Ad to hybrid tilapia may be primarily related to the activity of haemolysins (hlyA genes) and cytotoxins (aerolysin aerA), along with the production of siderophores and proteases. We also found β-lactamase, tetracycline and multiple antibiotic resistance genes, as well as adherence, iron acquisition, toxins (aerolysin family, haemolysins) and diverse protease genes.

Revista De Biologia Tropical, Sep 23, 2013

Aquaculture, May 1, 2006

Shrimp culture is the most profitable type of aquaculture in Mexico and it is highly developed in... more Shrimp culture is the most profitable type of aquaculture in Mexico and it is highly developed in the northern states of the Pacific coast. A reduced number of commercial shrimp farms have been established along the coast of the Yucatan Peninsula and have initiated operations with Litopenaeus vannamei. The Federal Government is concerned about the use of exotic species for aquaculture and has prompted research on domestication of Gulf of Mexico native penaeids. This paper reports the first outbreak of necrotizing hepatopancreatitis (NHP) in a farm culturing L. vannamei in Campeche State, Southern Mexico. The implications of this finding with respect to native shrimp species and aquaculture development for the region are discussed.

Journal of Fish Diseases, 2021

Between August and December 2013, the offshore cages of a commercial marine farm culturing red dr... more Between August and December 2013, the offshore cages of a commercial marine farm culturing red drum Sciaenops ocellatus in Campeche Bay Mexico were affected by an outbreak of an ulcerative granulomatous disease with up to 70% cumulative mortality. Thirty‐one adults displaying open ulcers on the skin were submitted for diagnosis. At necropsy, multiple white‐yellowish nodules (0.1–0.5 cm in diameter) were present in all internal organs, where the kidney and the spleen were the most severely affected. Histopathology evinced typical systemic granulomatous formations. Gram and Ziehl–Neelsen stains on tissue imprints, bacterial swabs and tissue sections revealed Gram‐positive, acid‐fast, branching beaded long rod filamentous bacteria. Tissue samples resulted positive for nocardiosis with a Nocardia genus‐specific nested PCR. Definite identification at the species level and taxonomic positioning of the fastidious pathogen were achieved through a specific Nocardia seriolae PCR and by sequen...

Aquaculture Research, 2020

Aquaculture is a rapidly developing economic activity that provides almost half the fish consumed... more Aquaculture is a rapidly developing economic activity that provides almost half the fish consumed by humans (FAO, 2018). Due to the rapid growth in aquaculture, there has been an increase in the demand of feed supplies for farmed species. Traditionally, FM is the main protein source for the formulation of aquaculture feeds, especially for carnivorous species. However, due to a global shortage of this ingredient, it has become a costly dietary macroelement. Therefore, there is a need to identify alternative protein sources to reduce the dependence on fishmeal (Tacon, Hasan, & Metian, 2011). Plants, such as soya bean meal, and animal by-products have the potential to be used to replace FM in diets for Lujannus gutattus. For instance, some dose-response studies of this species show that the expensive FM protein could be partially replaced by soya bean meal (up to 20% of the total protein source), pet grade poultry by-product meal (90%), feed grade poultry by-product meal (25%), tuna by-product meal (TBM) (30%) and meat and bone meal (35%) (Hernández

한국수산과학회 양식분과 학술대회, May 1, 2015

Current Microbiology, Sep 21, 2020

Acute hepatopancreatic necrosis disease (AHPND) is a severe disease affecting recently stocked cu... more Acute hepatopancreatic necrosis disease (AHPND) is a severe disease affecting recently stocked cultured shrimps. The disease is mainly caused by V. parahaemolyticus that harbors the pVA1 plasmid; this plasmid contains the pirA and pirB genes, which encode a delta-endotoxin. AHPND originated in China in 2009 and has since spread to several other Asian countries and recently to Latin America (2013). Many Asian strains have been sequenced, and their sequences are publicly accessible in scientific databases, but only four strains from Latin America have been reported. In this study, we analyzed nine pVA1-harboring V. parahaemolyticus sequences from strains isolated in Mexico along with the 38 previously available pVA1-harboring V. parahaemolyticus sequences and the reference strain RIMD 2210633. The studied sequences were clustered into three phylogenetic clades (Latin American, Malaysian, and Cosmopolitan) through pangenomic and phylogenomic analysis. The nucleotide sequence alignment of the pVA1 plasmids harbored by the Asian and Latin American strains confirmed that the main structural difference in the plasmid between the Asian and Latin American strains is the absence of the Tn3 transposon in the Asian strains; in addition, some deletions in the pirAB region were found in two of the Latin American strains. Our study represents the most robust and inclusive phylogenomic analysis of pVA1-harboring V. parahaemolyticus conducted to date and provides insight into the epidemiology of AHPND. In addition, this study highlights that disease diagnosis through the detection of the pirA and pirB genes is an inadequate approach due to the instability of these genes.

Aquaculture Research, Nov 15, 2021

Fish & Shellfish Immunology, Oct 1, 2022

Aquaculture International

Aquaculture, 2020

Juvenile C. viridis (5.26 ± 0.72 g) were intraperitoneally injected with three doses of Vibrio po... more Juvenile C. viridis (5.26 ± 0.72 g) were intraperitoneally injected with three doses of Vibrio ponticus (Vp) CAIM 1751 from 10 4 to 10 6 CFU/g, and histological analysis, haemolytic activity assessment and putative virulence genes identification were performed. The time of experimental challenge was 168 h. The virulence of Vp was dose-dependent. The mortality after 25 h post infection (p.i.) was 100% at 3.1 × 10 6 CFU/g and, 83% at 60 h p.i. at 2.9 × 10 5 CFU/g. The LC 50 was 2.9 × 10 5 CFU/g at 32 h p.i. Congestion and petechial haemorrhages in the ventral area were observed in the infected fish. Similar histological lesions were observed at the three doses as necrosis, congestion and bacterial masses in different organs and tissues. This is the first report where Vp caused in C. viridis pathological changes associated with an acute peritonitis that caused irreversible damage to the internal organs, except in the kidney. Greater severity was identified in the liver and pancreas of the organisms exposed to the higher dose and in the stomach, intestine and nervous system of the fish infected with the lower dose. The main virulence genes of Vp CAIM 1751 were auto inducers, toxins and iron acquisition, including three types of haemolysins and metalloproteases. Furthermore, this strain had a strong β-haemolytic reaction on erythrocytes of the Pacific white snook. The combined action of the proteases and haemolysins may be responsible for the vascular fragility allowing for the rupture of small vessels and haemorrhages in the tissues. This study contributes to our understanding of Vibrio ponticus as an emerging finfish aquaculture pathogen.

1 Departamento de Genética y Bioestadística, Facultad de Medicina Veterinaria y Zootecnia, Univer... more 1 Departamento de Genética y Bioestadística, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior, Coyoacán, CDMX, Mexico montaldo@unam.mx (Corresponding autor) 2 Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana, Unidad Xochimilco, Coyoacán, CDMX, Mexico 3 Departamento El Hombre y su Ambiente, Universidad Autónoma Metropolitana, Unidad Xochimilco, Coyoacán, CDMX, Mexico Maricultura del Pacífico, Mazatlán, Sinaloa, Mexico. 5 Centro de Investigación en Alimentación y Desarrollo, A.C. Unidad Mazatlán en Acuicultura y Manejo Ambiental, Mazatlán, Sinaloa, Mexico

Asian Fisheries Science, 2018

The objective of this paper is to present preliminary results regarding heritability, genetic lin... more The objective of this paper is to present preliminary results regarding heritability, genetic line differences and inbreeding effects for survival time in experimental challenges to acute hepatopancreatic necrosis disease (AHPND) in Penaeus vannamei Boone 1931. Here we present results of analyses conducted on data from a Resistance Line obtained from a merging of several Ecuadorian groups with a history of white-spot syndrome virus resistance, and a Growth Line with high genetic growth ability, obtained by selection in a Mexican hatchery. Family-identified animals from the two genetic lines and their crosses were inoculated by immersion in 2014, 2015 and 2016 using a Vibrio parahaemolyticus strain (M0904) AHPND+ obtained from a natural infection in Mexico. Heritabilities for survival time obtained using nested linear mixed models ranged from 9 to 18 %. Survival was greater for the Resistance Line compared to the Growth Line or the F 1 cross (P < 0.02). Our results point to the presence of additive genetic variation in both lines evaluated that may be exploited in breeding programmes to increase AHPND resistance.

Diseases of Aquatic Organisms, 2020

Vibrio parahaemolyticusstrains have been identified as the causative agent of acute hepatopancrea... more Vibrio parahaemolyticusstrains have been identified as the causative agent of acute hepatopancreas necrosis disease (VpAHPND+) in shrimp. In the present work, a highly virulent (M0904) and less virulent (M0607) strain ofVpAHPND+ were used in experimental infections ofPenaeus vannamei. Throughout the experiment, histopathological analyses were conducted on shrimp tissues, and samples from the bottom (B) and water column (WC) of each aquarium were taken to estimate bacterial growth. The first deaths of shrimp challenged withVpM0904 occurred 4 h post-infection (hpi), reached 50% mortality at 17 hpi, and showed more acute pathological progression associated with AHPND despite both strains having similar bacterial densities from 0-4 hpi. The first deaths of shrimp inoculated withVpM0607 occurred at 13 hpi, a difference of 9 h. These shrimps displayed reduction of reserve vacuoles in R and B cells of the hepatopancreas, and reached 50% mortality at 27 hpi. As bacterial growth in the WC an...

Pathogens, 2020

Vibrio parahaemolyticus (Vp) is the etiological agent of the acute hepatopancreatic necrosis dise... more Vibrio parahaemolyticus (Vp) is the etiological agent of the acute hepatopancreatic necrosis disease (AHPND) in Penaeus vannamei shrimp. Vp possesses a 63–70 kb conjugative plasmid that encodes the binary toxin PirAvp/PirBvp. The 250 kDa PirABvp complex was purified by affinity chromatography with galactose-sepharose 4B and on a stroma from glutaraldehyde-fixed rat erythrocytes column, as a heterotetramer of PirAvp and PirBvp subunits. In addition, recombinant pirB (rPirBvp) and pirA (rPirAvp) were obtained. The homogeneity of the purified protein was determined by SDS-PAGE analysis, and the yield of protein was 488 ng/100 μg of total protein of extracellular products. The PirABvp complex and the rPirBvp showed hemagglutinating activity toward rat erythrocytes. The rPirAvp showed no hemagglutinating capacity toward the animal red cells tested. Among different mono and disaccharides tested, only GalNH2 and GlcNH2 were able to inhibit hemagglutination of the PirABvp complex and the rP...

Aquaculture, 2020

al., Genetic (co)variation in resistance of Pacific white shrimp Litopenaeus vannamei to acute he... more al., Genetic (co)variation in resistance of Pacific white shrimp Litopenaeus vannamei to acute hepatopancreatic necrosis disease (AHPND) and white spot syndrome virus (WSSV) in challenge tests, aquaculture (2019),

Journal of Applied Phycology, 2019

Ag-based nanoparticles (NPs) were successfully produced through green synthesis using an aqueous ... more Ag-based nanoparticles (NPs) were successfully produced through green synthesis using an aqueous extract from the cultivated seaweed Ulva clathrata as the reducing and stabilizing agent. The biosynthesized NPs had spherical to polymorphic shapes with an average size of 9.5 nm. Microstructural and compositional studies revealed that these particles contained face-centred cubic crystallites of metallic Ag and AgCl. Characteristic peaks in the Fourier-transform infrared spectrum (FTIR) and Raman studies revealed the presence of functional bioactive metabolites from the seaweed extract, such as proteins, polysaccharides, and polyphenols, which are responsible for forming and stabilizing Ag/AgCl NPs. The biosynthesized Ag/AgCl NPs exhibited an important in vitro antibacterial effect against three Vibrio parahaemolyticus strains isolated from farmed shrimp affected with acute hepatopancreatic necrosis disease (AHPND) in northwestern Mexico. Litopenaeus vannamei shrimp were exposed for 7 days to feeds supplemented with Ag/AgCl NPs at 10, 100, 1000, or 10,000 ppm (Ag nominal dietary concentrations). Dietary NP supplement did not affect shrimp survival, growth, or feed conversion ratio, but high concentrations (1000 and 10,000 ppm) decreased the hepatosomatic index significantly. The short-term consumption of Ag/AgCl NPs produced a significant dosedependent bioaccumulation of Ag in the hepatopancreas and to a lesser extent in the cuticle, while bioaccumulation in the muscle was not significant. The depuration study confirmed a fast Ag assimilation in shrimp's hepatopancreas and showed a fast depuration rate in the hepatopancreas as well.

Diseases of Aquatic Organisms, 2019

To examine the pathogenicity of Vibrio strains, several doses of Vibrio harveyi (CAIM 1622 and CA... more To examine the pathogenicity of Vibrio strains, several doses of Vibrio harveyi (CAIM 1622 and CAIM 1508), Vibrio ponticus (CAIM 1751) and Vibrio anguillarum (CAIM 8) were used to challenge Pacific white snook Centropomus viridis Lockington, 1877 juveniles, and survival, gross signs and histological lesions were observed. Susceptibility of pathogenic vibrios CAIM 1508 and CAIM 1751 to antibiotics used in aquaculture was also evaluated. The growth ability of the tested strains was not related to their pathogenicity. One of the V. harveyi strains (CAIM 1508) was the most virulent, causing per-acute septicaemia in C. viridis even at a low dose (1.4 × 104 CFU g-1). Although the V. ponticus strain (CAIM 1751) was less virulent, this is the first report of it as a pathogen of white snook. Fish challenged with V. ponticus displayed external, generalized haemorrhaging. Necrosis of the digestive tract and intravascular haemosiderosis were the most remarkable histological lesions in fish challenged with both strains. Multifocal necrosis of the internal organs and bacterial masses was also observed. The lowest minimum inhibitory concentration of the pathogenic strains (CAIM 1508 and CAIM 1751) was calculated for enrofloxacin (20 and 10 µg ml-1, respectively), and both bacteria were resistant to amoxicillin, ampicillin and trimethoprim-sulfamethoxazole.

Asian Fisheries Science, 2018

Moribund whiteleg shrimp (Penaeus vannamei) affected by acute hepatopancreatic necrosis disease (... more Moribund whiteleg shrimp (Penaeus vannamei) affected by acute hepatopancreatic necrosis disease (AHPND) from farms in northwestern Mexico were sampled for pathological analysis. Bacterial isolates were molecularly identified as Vibrio parahaemolyticus (VP) by the presence of the tlh gene. The tdh-negative, trh-negative and tlh-positive VP strains were further characterized by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The VP pure strains were used in immersion challenges with shrimp, and farmed and challenged shrimp presented the same clinical and pathological signs: lethargy, empty gut, pale and aqueous hepatopancreas and expanded chromatophores. Using fresh mount, histological analysis and bacterial density count, three stages of AHNPD (initial, acute and terminal) were identified in the affected shrimp. Pathognomonic lesions indicated severe desquamation of tubular epithelial cells of the hepatopancreas. VP had different virulence and was dose dependent. VP strains showed wide tolerance to different environment conditions of temperature, salinity and pH, and pathogenic and non-pathogenic VP strains from Mexico had similar morphological and physiological characteristics but pathogenic VP strains were most sensitive to nalidixic acid and showed resistance to penicillin. Whole genomic sequence of 22 VP strains from Asia, Mexico and South America shows the presence of similar chromosomic pathogenic mechanisms, and comparative analysis by multilocus sequence analysis (MLSA) of seven genes clearly showed that most of the isolates are independent strains.

Diseases of Aquatic Organisms, 2018

Aeromonas dhakensis (Ad) CAIM 1873 growth was evaluated at different conditions and antibiotic su... more Aeromonas dhakensis (Ad) CAIM 1873 growth was evaluated at different conditions and antibiotic susceptibility. Mortality and histopathological damages in hybrid tilapia Oreochromis niloticus × O. mossambicus, and virulence factors caused by Ad bacterial cells and extracellular products (ECPs) were evaluated, and the whole genome was obtained. Ad grew between 0.0 and 5.5% NaCl at a pH of between 4 and 10 and from 4 to 37°C. The lowest minimum inhibitory concentration was found for enrofloxacin (< 5 µg ml −1), and bacteria were resistant to erythromycin, amoxicillin and ampicillin. Ad bacterial cells (1.86 × 10 5 cells g −1) and ECPs (0.462 µg protein fish −1) were highly virulent to challenged hybrid tilapia and caused over 80% mortality at 24 h. The primary clinical sign caused was haemorrhage, and damage was most marked in the spleen, liver, kidney and brain of fish challenged with bacterial cells. To our knowledge, this is the first report that Ad causes pyknotic and karyorrhectic nuclei of erythrocytes in the internal organs of hybrid tilapia, which was the most striking histopathological observation. The virulence of Ad to hybrid tilapia may be primarily related to the activity of haemolysins (hlyA genes) and cytotoxins (aerolysin aerA), along with the production of siderophores and proteases. We also found β-lactamase, tetracycline and multiple antibiotic resistance genes, as well as adherence, iron acquisition, toxins (aerolysin family, haemolysins) and diverse protease genes.

Revista De Biologia Tropical, Sep 23, 2013

Aquaculture, May 1, 2006

Shrimp culture is the most profitable type of aquaculture in Mexico and it is highly developed in... more Shrimp culture is the most profitable type of aquaculture in Mexico and it is highly developed in the northern states of the Pacific coast. A reduced number of commercial shrimp farms have been established along the coast of the Yucatan Peninsula and have initiated operations with Litopenaeus vannamei. The Federal Government is concerned about the use of exotic species for aquaculture and has prompted research on domestication of Gulf of Mexico native penaeids. This paper reports the first outbreak of necrotizing hepatopancreatitis (NHP) in a farm culturing L. vannamei in Campeche State, Southern Mexico. The implications of this finding with respect to native shrimp species and aquaculture development for the region are discussed.

Journal of Fish Diseases, 2021

Between August and December 2013, the offshore cages of a commercial marine farm culturing red dr... more Between August and December 2013, the offshore cages of a commercial marine farm culturing red drum Sciaenops ocellatus in Campeche Bay Mexico were affected by an outbreak of an ulcerative granulomatous disease with up to 70% cumulative mortality. Thirty‐one adults displaying open ulcers on the skin were submitted for diagnosis. At necropsy, multiple white‐yellowish nodules (0.1–0.5 cm in diameter) were present in all internal organs, where the kidney and the spleen were the most severely affected. Histopathology evinced typical systemic granulomatous formations. Gram and Ziehl–Neelsen stains on tissue imprints, bacterial swabs and tissue sections revealed Gram‐positive, acid‐fast, branching beaded long rod filamentous bacteria. Tissue samples resulted positive for nocardiosis with a Nocardia genus‐specific nested PCR. Definite identification at the species level and taxonomic positioning of the fastidious pathogen were achieved through a specific Nocardia seriolae PCR and by sequen...