Morphometric analysis of the gastrointestinal tract of four African muroid rodent species (Rhabdomys dilectus , Rhabdomys pumilio , Aethomys chrysophilus , and Lemniscomys rosalia )

2018 ◽  
Vol 279 (9) ◽  
pp. 1282-1289
Author(s):  
Zaskia Henke ◽  
Lauren Sahd ◽  
Sonja Matthee ◽  
Sanet H. Kotzé
Keyword(s):  
Gastrointestinal Tract ◽  
Morphometric Analysis ◽  
Rodent Species ◽  
Rhabdomys Pumilio ◽  
Muroid Rodent

scholarly journals Experimental plague infection in South African wild rodents

1986 ◽  
Vol 96 (2) ◽  
pp. 171-183 ◽  
Author(s):  
A. J. Shepherd ◽  
P. A. Leman ◽  
D. E. Hummitzsch
Keyword(s):  
South Africa ◽  
South African ◽  
Rodent Species ◽  
Enzyme Linked Immunosorbent Assay ◽  
Wild Rodents ◽  
Infectious Dose ◽  
Rhabdomys Pumilio ◽  
Dramatic Decline ◽  
Northern Cape ◽  
Moderately Resistant

SUMMARYSusceptibility studies were undertaken to determine the response of some South African wild rodent species to experimental plague (Yersinia pestis) infection.A degree of plague resistance was found in three gerbil species captured in the plague enzootic region of the northern Cape Province, these being the Namaqua gerbil, Desmodillus auricularis, (LD50 1 × 106 organisms), the bushveld gerbil, Tatera leucogaster, (LD50 9·1 × 105) and the highveld gerbil, T. brantsii (LD50 4 × 102). Animals from a population of the four-striped mouse, Rhabdomys pumilio, captured in the plague area of Port Elizabeth, proved moderately resistant to experimental plague infection (LD 50 1·3 × 104) while those from another population of the same species captured in a plague-free area of the Orange Free State were extremely susceptible (LD50, 5 organisms). The response of both populations however was a heterogeneous one. Marked differences in susceptibility were also found between two populations of multimammate mice, Mastomys natalensis (2n = 32) although both originated from areas outwith the known distribution of plague in southern Africa.The 50% infectious dose was relatively high in T. leucogaster (3·2 × 102) and D. auricularis (1·7 × 103), but was low (2–16 organisms) in the other rodent species tested.The plague antibody response, determined by enzyme-linked immunosorbent assay (ELISA), was extremely short-lived in T. leucogaster, only 10% of inoculated animals remaining seropositive at low titres after 11 weeks. Antibodies persisted for only slightly longer in the sera of T. brantsii which were reinoculated with 2 × 103 plague organisms 6 weeks after initial challenge.The demonstration of the existence of both susceptible and resistant populations of R. pumilio and M. natalensis indicates that these species must be considered as potential plague reservoir hosts in parts of South Africa.The results suggest that resistance to plague infection in previously epizootic hosts in the northern Cape Province such as Tatera sp. and D. auricularis has arisen through continual selective pressure of the organism. If the findings are applicable to gerbil populations in other plague enzootic regions of South Africa it is probable that acquired plague resistance has been responsible for the absence of gerbil epizootics and consequently for the dramatic decline in human plague outbreaks in South Africa since 1950.

scholarly journals Striped mice, Rhabdomys pumilio, and other murid rodents as hosts for immature ixodid ticks in the Eastern Cape Province

2004 ◽  
Vol 71 (4) ◽  
Author(s):  
T.N. Petney ◽  
I.G. Horak ◽  
D.J. Howell ◽  
S. Meyer
Keyword(s):  
Tick Species ◽  
Nature Reserve ◽  
Rattus Rattus ◽  
Ixodid Tick ◽  
Ixodid Ticks ◽  
Rodent Species ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Rhabdomys Pumilio ◽  
Murid Rodents

Striped mice, Rhabdomys pumilio, were trapped over a period of 17 months in the Thomas Baines Nature Reserve, and placed in cages, over water, until all the ticks they harboured had detached. The mice were then returned to the reserve. Four ixodid tick species were recovered from the mice of which the larvae and nymphs of Rhipicephalus follis and Rhipicephalus simus were the most numerous. Most larvae of R. follis detached from mice trapped from March to July, and most nymphs in March and from June to September. Most larvae of R. simus detached from mice trapped from December to March, and most nymphs from January to March and during May and June. Seven ixodid tick species were collected from striped mice, house rats, Rattus rattus, vlei rats, Otomys spp. and Praomys sp. captured in the vicinity of human dwellings or animal holding facilities in the Grahamstown district. The striped mice captured in the Thomas Baines Reserve harboured considerably larger numbers of ticks than any of the rodent species in the more urbanized localit

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

Morphometric Analysis of the Hepatocytes from Fish Exposed to Arsenic

1976 ◽  
Vol 34 ◽  
pp. 282-283
Author(s):  
Elsie M. B. Sorensen
Keyword(s):  
Morphometric Analysis ◽  
Arsenic Concentration ◽  
Ultrastructural Changes ◽  
Sodium Arsenate ◽  
Lepomis Cyanellus ◽  
Mammalian Counterpart ◽  
Intracellular Changes ◽  
Green Sunfish ◽  
Organic Pesticides

The detoxification capacity of the liver is well documented for a variety of substances including ethanol, organic pesticides, drugs, and metals. The piscean liver, although less enzymatically active than the mammalian counterpart (1), contains endoplasmic reticulum with an impressive repertoire of oxidizing, reducing, and conjugating abilities (2). Histopathologic changes are kncwn to occur in fish hepatocytes following in vivo exposure to arsenic (3); however, ultrastructural changes have not been reported. This study involved the morphometric analysis of intracellular changes in fish parynchymal hepatocytes and correlation with arsenic concentration in the liver.Green sunfish (Lepomis cyanellus, R.) were exposed to 0, 30, or 60 ppm arsenic (as sodium arsenate) at 20°C for 1, 2, or 3 week intervals before removal of livers for quantification of the arsenic burden (using neutron activation analysis) and morphometric analysis of ultrastructural alterations. Livers were cut into 1 mm cubes for fixation, dehydration, and embedding.

Sign in / Sign up

Export Citation Format

Share Document