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 ...

Advances in research on the major causative agents of morbidity and mortality in newborn alpacas associated with enteric processes in southern Peru were reviewed. Microbiology and molecular analyses performed on intestinal samples from enterotoxemia fatalities confirmed the predominance of C. perfringens type A carrying only the gene coding for the major α exotoxin and identifiying for the first time the presence of the novel β2 toxin gene. In vitro studies have yielded three profiles for phospholipase activity (high, medium and low) with biological activity when high and medium strains were inoculated intraintestinally in mice and rabbits, but did not induce intestinal pathology in an alpaca cria. A detailed histopathological investigation has reveled that within necrotizing hemorrhagic enteritis Clostridium coexist with massive presence of Eimeria macusaniensis suggesting that primar...

Advances in research on the major causative agents of morbidity and mortality in newborn alpacas associated with enteric processes in southern Peru were reviewed. Microbiology and molecular analyses performed on intestinal samples from enterotoxemia fatalities confirmed the predominance of C. perfringens type A carrying only the gene coding for the major α exotoxin and identifiying for the first time the presence of the novel β2 toxin gene. In vitro studies have yielded three profiles for phospholipase activity (high, medium and low) with biological activity when high and medium strains were inoculated intraintestinally in mice and rabbits, but did not induce intestinal pathology in an alpaca cria. A detailed histopathological investigation has reveled that within necrotizing hemorrhagic enteritis Clostridium coexist with massive presence of Eimeria macusaniensis suggesting that primar...

The results of our recent research work on enterotoxemia in Peruvian alpacas are presented. Microbiological and molecular analyses found that the majority of the isolates corresponded to Clostridium perfringens and contained the cpa coding gene for α toxin (A genotype) while 0.4% contained both the cpa and cpb genes of the α and β toxins (C genotype). A parallel study revealed that 8.5% of the genotype A isolates also had cpb2, but the cpe (enterotoxin) gene was absent in all cases. These results highly suggest that the exotoxins secreted by C. perfringens are the virulent factors in enterotoxemia, rather than the endogenous enterotoxin. Additionally, an histopathological study of intestinal samples from fatal cases showed that 30.6% had abundant immature structures of Eimeria macusaniensis affecting deep mucosa and cryptic gland epithelia, primarily in the jejune and ileum, suggestin...

The objective of the present study was to determine the levels of serum immunoglobulin G (IgG) in neonatal alpacas (5-23 days of age) killed by enterotoxemia and in animals of similar ages, but clinically healthy. In a first phase, a standard curve of physiological degradation of serum IgG was established from blood sera of six apparently healthy neonates from day 2 to 21 days of age (n=9). In a second phase, serum IgG concentrations were determined in 17 dead neonatal alpacas with lesions compatible with enterotoxemia and in 26 animals of similar ages, apparently healthy. The concentrations of IgG, determined by the Radial Immunodiffusion test, showed that all the animals at 48 hours of birth had adequate concentrations of IgG, while only three of the animals killed by enterotoxemia had IgG levels below the obtained standard curve, although only one of them with levels below 900 mg/dl a...

The results of our recent research work on enterotoxemia in Peruvian alpacas are presented. Microbiological and molecular analyses found that the majority of the isolates corresponded to Clostridium perfringens and contained the cpa coding gene for α toxin (A genotype) while 0.4% contained both the cpa and cpb genes of the α and β toxins (C genotype). A parallel study revealed that 8.5% of the genotype A isolates also had cpb2, but the cpe (enterotoxin) gene was absent in all cases. These results highly suggest that the exotoxins secreted by C. perfringens are the virulent factors in enterotoxemia, rather than the endogenous enterotoxin. Additionally, an histopathological study of intestinal samples from fatal cases showed that 30.6% had abundant immature structures of Eimeria macusaniensis affecting deep mucosa and cryptic gland epithelia, primarily in the jejune and ileum, suggestin...

El presente estudio tuvo como objetivo determinar los niveles de Inmunoglobulina G (IgG) sérica en alpacas neonatas (5-23 días de edad) muertas por enterotoxemia y en animales de edades similares, pero clínicamente sanos. En una primera fase se estableció una curva estándar de degradación fisiológica de la IgG sérica a partir de sueros sanguíneos de seis neonatos aparentemente sanos a partir del día 2 y hasta los 21 días de edad (n=9). En una segunda fase se determinaron las concentraciones de IgG sérica en 17 alpacas neonatas muertas con lesiones compatibles con enterotoxemia y en 26 animales, de edades similares, aparentemente sanos. Las concentraciones de IgG, determinadas por la prueba de Inmunodifusión Radial, evidenciaron que todas las crías a las 48 horas del nacimiento presentaron concentraciones adecuadas de IgG, mientras que solo tres de los animales muertos por e...