The study aimed to determine the seroprevalence and risk of infection of bovine leptospirosis in dairy farms of the Peruvian coast and highlands. A total of 88 blood samples were obtained in a farm in the area of Lima (coast) and 163 samples in a farm in the area of Huancayo (highlands), both belonging to the National University of San Marcos. The samples were analyzed by the microagglutination test to detect antibodies to serovars canicola, pomona, icterohaemorrhagiae and hardjo. Seroprevalences of 14.8 and 12.3% were found in Lima and Huancayo farms respectively, where the serovar icterohaemorrhagiae was the only detected in Lima and serovars icterohaemorrhagiae and hardjo in Huancayo farms.

The study aimed to determine the seroprevalence and risk of infection of bovine leptospirosis in dairy farms of the Peruvian coast and highlands. A total of 88 blood samples were obtained in a farm in the area of Lima (coast) and 163 samples in a farm in the area of Huancayo (highlands), both belonging to the National University of San Marcos. The samples were analyzed by the microagglutination test to detect antibodies to serovars canicola, pomona, icterohaemorrhagiae and hardjo. Seroprevalences of 14.8 and 12.3% were found in Lima and Huancayo farms respectively, where the serovar icterohaemorrhagiae was the only detected in Lima and serovars icterohaemorrhagiae and hardjo in Huancayo farms.

The aim of this study was to identify Y. ruckeri genotypes, according to their origin, by RAPD-PCR. Aseptic samples of spleen and kidney were taken from rainbow trout (Oncorhynchus mykiss) with clinical signs of yersiniosis in fish farms of four departments (Junín, Lima, Ancash and Puno) of Peru. The strains were cultivated on trypticase soy agar at 25 °C for 24 hours and the presumptive identification of the colonies suspected of being Y. ruckeri was made by Gram stain and biochemical tests of oxidase and catalase. Then, the identity of Y. ruckeri was confirmed by PCR. In total, 63 isolates of Y. ruckeri were obtained and analyzed by RAPD-PCR. The dendogram of genetic diversity grouped all the isolates in one cluster, closely related to the control strain Y. ruckeri ATCC 29473 (96% similarity). It was also observed that all the isolates were genetically identical (clones). It is sugge...

The aim of this study was to identify Y. ruckeri genotypes, according to their origin, by RAPD-PCR. Aseptic samples of spleen and kidney were taken from rainbow trout (Oncorhynchus mykiss) with clinical signs of yersiniosis in fish farms of four departments (Junín, Lima, Ancash and Puno) of Peru. The strains were cultivated on trypticase soy agar at 25 °C for 24 hours and the presumptive identification of the colonies suspected of being Y. ruckeri was made by Gram stain and biochemical tests of oxidase and catalase. Then, the identity of Y. ruckeri was confirmed by PCR. In total, 63 isolates of Y. ruckeri were obtained and analyzed by RAPD-PCR. The dendogram of genetic diversity grouped all the isolates in one cluster, closely related to the control strain Y. ruckeri ATCC 29473 (96% similarity). It was also observed that all the isolates were genetically identical (clones). It is sugge...

The aim of this study was to evaluate the presence of Perkinsus spp, a parasite that is mandatory to be report to the OIE, in samples of calico scallop (Argopecten purpuratus) from Ancash, Peru, using the PCR technique. In total, 56 samples were selected from those collected for a previous study in 2015. The selected samples were gill tissues with histological lesions suggestive of infection with the protozoan (hemocytic infiltration and necrosis). DNA was extracted from the samples and specific primers were used to detect Perkinsus spp by PCR. In addition, the detection limit of the technique was evaluated. All samples were negative. It was determined that 1.63 ng was the least detectable template DNA in one of the positive controls.

The aim of this study was to evaluate the presence of Perkinsus spp, a parasite that is mandatory to be report to the OIE, in samples of calico scallop (Argopecten purpuratus) from Ancash, Peru, using the PCR technique. In total, 56 samples were selected from those collected for a previous study in 2015. The selected samples were gill tissues with histological lesions suggestive of infection with the protozoan (hemocytic infiltration and necrosis). DNA was extracted from the samples and specific primers were used to detect Perkinsus spp by PCR. In addition, the detection limit of the technique was evaluated. All samples were negative. It was determined that 1.63 ng was the least detectable template DNA in one of the positive controls.

The aim of this study was to compare histological lesions of rainbow trout (Oncorhynchus mikyss) affected by the bacterial cold water disease (BCDW) with asymptomatic trout skin samples from fish farms in Lake Titicaca (Puno, Peru) and identify the presence of Flavobacterium psychrophilum by conventional PCR. Thirteen trout with skin lesions and seven without lesions, with sizes greater than 25 cm and average weight of 350 g were used. Conventional PCR was performed for the identification of Flavobacterium psychrophilum, using primers directed to the 16S rRNA region. Molecularly, both groups of animals were positive for the presence of F. psycrophilum. It can be concluded that this pathogen is present in the southern part of the country.

The aim of this study was to compare histological lesions of rainbow trout (Oncorhynchus mikyss) affected by the bacterial cold water disease (BCDW) with asymptomatic trout skin samples from fish farms in Lake Titicaca (Puno, Peru) and identify the presence of Flavobacterium psychrophilum by conventional PCR. Thirteen trout with skin lesions and seven without lesions, with sizes greater than 25 cm and average weight of 350 g were used. Conventional PCR was performed for the identification of Flavobacterium psychrophilum, using primers directed to the 16S rRNA region. Molecularly, both groups of animals were positive for the presence of F. psycrophilum. It can be concluded that this pathogen is present in the southern part of the country.

The objective of this study was to assess the effect of effective microorganisms (EM) on the growth and survival of Litopenaeus vannamei “white shrimp” reared in a semi-intensive system in the region of Tumbes, Peru. Post-larvae (PLs) of approximately 0.02 g were cultured (15 PLs/m2) in four ponds (E) distributed in two groups: E1-E2 as controls (without EM), and E3-E4 with EM supplementation. EM was added to feed daily and directly to the water weekly. From each pond, 200 shrimps were captured weekly to assess the growth parameter (weight). Analysis of variance and Tukey’s test were used to determine significant differences in weight growth. The water physical- chemical parameters were monitored (daily and weekly), while, organic matter was determined at the beginning and at the end of the experiment. Finally, the economic indicators of the study were evaluated. Significant differ...

The aim of this study was to detect parasitic agents and describe histopathological lesions in scallops (Argopecten purpuratus) from Ancash, Peru, during the summer and winter periods. In total, 360 mollusks were collected, in equal parts from aquaculture farms and wildlife, and in the summer and winter seasons (90 per group). The samples were preserved in Davidson's solution and analyzed by histology. The Chi-square test was used to determine possible associations between the variables. The histopathological findings in digestive glands and gills were similar, finding intracellular microcolonies of bacteria (ICM), hemocyte infiltration and tissue necrosis in all study groups. The prevalence of MCI was associated with the season of the year. Nephridial concretions occurred in all groups. The mantle was mostly affected by the presence of trematodes and hemocyte infiltration, especially in...

In the present study, 24 native supernatants isolated from enterotoxemia fatalities were evaluated to characterize lecitinase, hemolytic, in vitro cytotoxicity, and in vivo enterotoxicity activities of the phospholipase C (Cp-PLC) exotoxin. The lecitinase activity was monitored in microplates using egg white emulsifications, the hemolityc and perfringolisine in microplates using sheep and equine eritrocytes respectively, the cytotoxic activity was tested on HEp-2 cells and the enterotoxicity by inoculating within intestinal loops of rabbits. At the molecular level, all the isolates (12 vegetative and 12 sporulated) were found to contain the cpa gene (genotype A), while six also contained cpb2 gene but none had the cpe gene. These isolates were classified, according the lecitinase activity, as high, medium and low producer strains. Most of the vegetative (66.6%) isolates had high and medi...

Se reportan evaluaciones de sobrenadantes bacterianos (nativos) crudos obtenidos de 24 aislados de C. perfringens de casos fatales de enterotoxemia buscando caracterizar propiedades lecitinasas, hemolíticas, citotóxicas in vitro y enterotóxicas in vivo de la exotoxina fosfolipasa C (Cp-PLC). Los aislados (12 en estados vegetativos y 12 esporulados) contenían el gen cpa (genotipo A), y seis de ellos tenían además el gen cpb2, pero todos carecían del gen de la enterotoxina (cpe). Las actividades lecitinasas fueron evaluadas, en microplacas, usando emulsiones de yemas de huevo; las hemolíticas y perfringolisina en microplacas, usando eritrocitos de carnero y de equino respectivamente; las citotóxicas, en células HEp-2; y las enterotóxicas en conejos inoculados intraintestinalmente. Los aislados fueron clasificados, de acuerdo a los niveles de la actividad lecitinasa, en cepas de ...