Observaciones sobre la Bartonelosis en el Cuy: Cavia Porcellus
Rev. peru. med. exp. salud publica; 2 (1), 1943
Publication year: 1943
1. La Haemobartonella tyzzeri ha sido observada microscópicamente en 3 cuyes machos de 10 cuyes esplenectomizados procedentes de la zona verrucógena del Rímac.,, (5 machos, 5 hembras), mientras que 3 machos y 1 hembra de Lima resultaron negativos. 2. Una vez se ha cultivado la H. tyzzeri en el medio semi-sólido de NOGUCHI a 28ºC. 3. Sangre de un cuy naturalmente infectado fué inyectado intraperitonealmente a un cuy esplenectomizado de Lima; a las 2 semanas las bartonellas eran visibles en la sangre. De esta manera fueron inoculados 6 cuyes en pasajes sucesivos, siempre con resultados positivos. El porcentaje de glóbulos infectados (± 0.05 % en el cuy original), subió durante estos pasajes, hasta un máximo de 6.25%. El período de incubación bajó en los dos últimos pasajes hasta 1 semana. Tres de los 6 animales mostraron una ligera anemia (con 3.48, 3.74, y 3,19 millones de hematíes por mm.3, respectivamente) y otro (el del segundo pasaje) una anemia fuerte (1.25 millón), con macrocitos, normoblastos y un alto porcentaje de reticulocitos. Está comprobado pues, que la virulencia de la H. tyzzeri puede ser aumentada. 4. Se ha estudiado el cuadro hemático con los resultados siguientes. El diámetro medio del glóbulo parasitado resulta por lo. general un poco más pequeño que el del no infectado, diferencia que por lo menos en un caso no se podría atribuir al azar. En tres cuyes se observó un aumento de los hematíes, precediendo al descenso de éstos. En algunos de los cuyes parasitados se notó una disminución del número de los leucocitos, seguido por una leucocitosis, la cual era unas veces acompañada, de un aumento del porcentaje de los granulocitos neutrófilos. Eosinofílía durante o después de la infección fué observada en tres cuyes, monocitosis en dos. Algunas veces se pudo poner de manifiesto una hipersegmentación del núcleo de los granulocitos. 5. Se realizó un estudio anátomo-patológico del hígado de algunos cuyes parasitados y del bazo de un cuy naturalmente infectado; también dé un pedazo del bazo, dejado con una esplenectomía incompleta en otro cuy experimentalmente infectado.
1. Haemobartonella tyzzeri was observed in Giemsa-stained films of the blood of 3 male guinea-pigs out of 10 splenectomized animals coming from the verruga zone of the Rimac Valley. As 5 of these guinea-pigs happened to be males and 5 females, it is possible that in nature males are more frequently infected than females. Four splenectomized guinea-pigs from Lima (3 males, 1 female) have been repeatedly examine d with negative results. 2. After several failures H. tyzzeri was cultivated once from the blood of an experimentally infected guinea-pig in the semi-solid medium of NOGUCHI at 28ºC. 3. Blood of one naturally infected guinea-pig was injected intraperitoneally into a splenectomized guinea-pig from Lima; two weeks later the bartonellae were visible in its blood. This strain was carried through six, successive passages in splenectomized guinea-pigs. Three of the latter (males) came from Lima, the other three (females) from the Rimac Valley, but had been examined first during at least one month with negative results. Thus it seems that females from the verruga zone, are not immune against experimental infection with H. tyzzeri. During these animal passages there was a decreased in the mean number of bartonellae per infected red cell (from 17 in the original guinea-pig to 11, 12, 7, 7, 2 and 6), as well as in the maximum observed for any red cell. (from 28 in the original guinea-pig to 6, 25, 16, 16, 6 and 8). However, the percentage of infected red blood corpuscles increased from 0.05% to 6.25% during these passages. The period of incubation decreased from 17 days in the original guinea-pig to 1 week during the last two passages. Three of the six experimentally infected animals showed a slight anemia, with respectively 3.48, 3.74 and 3.19 million red cells per cu.mm., while one (second passage) showed a severe anemia (1.25 million) with macrocytes, numerous normoblasts and 47% of reticulocytes. This indicates that the virulence of H. tyzzeri can be increased. 4. The diameter of the infected erithrocytes was slightly smaller than that of the non - infected ones; it has been calculated that in at least one case this difference could not be explained by chance. (Cuadro 1). In 3 infected guinea-pigs the red count increased in the first period of infection. Some of the infected guinea-pigs showed a temporary leucopenia before bartonellae appeared in the blood; the infection period, however, was caracterized by leucocytosis, (Cuadro 2) which was in some cases accompanied by a relative increase of the neutrophiles. Eosinophilia during or after the period of infection has been observed in 5 guinea-pigs but 2 of these cases could be explained by the presence of worms. (Cuadro 3). In the blood of some infected guinea-pigs an increased nuclear segmentation of the neutrophiles was detected. (Cuadro 4). 5. A pathological study was made of the liver of the infected animals. The principal changes found were degeneration of the liver-cells, focal areas of necrosis and proliferation of connective tissue, (especially around the bile-ducts) and extensive phagocytosis of blood. corpuscles and blood pigment. No signs of inflamation were present. At the autopsy of the sixth passage guinea-pig a small piece of the spleen was found, obviously the consequence of an incomplete splenectomy. This showed marked reduction of lymphoid tissue and hyperplasia of the pulp; hyaline degeneration surrounded the small arteries in the Malpighian bodies. Numerous macrophages contained brown pigment.