herpetological microbiology
Table of contents:
An infection with so called free living amebas of the genera Acanthamoeba and Naegleria is a very interesting mode of amebiasis, worked out by us several times scientifically.
Walochnik codicillo primo animalum causa
Isolation and identification by partial sequencing of the 18S ribosomal gene of free-living amoebae from necrotic tissue of Basiliscus plumifrons (Sauria: Iguanidae). |
A 3-year-old Basiliscus plumifrons developed a necrotic lesion on the tail resulting from nodules of unknown etiology. Investigation of necrotic tissue re- vealed several gram-negative bacteria as well as three different species of free-living amoebae. The amoebae were identifed by morphological characters as belonging to the genera Acanthamoeba, Echinamoeba, and Naegleria, | respectively. Partial sequencing of the 18S ribosomal gene was performed for reliable systematic determination. Two of the isolates showed thermotol- erance. No isolate was growable in conventional liquid media, but the Acanthamoeba strain readily grew on a human cell line (HEp2). It remains unclear whether the amoebae fed on the coexisting bacteria or on host tissue. |
Weeksella virosa
Hassl codicillo quinto membranarum bacteriorum causa
Weeksella virosa HOLMES et al., 1987 colonised epidermal cysts in Hyla crepitans WIED-NEUWIED, 1824 (Anura: Hylidae). |
 A tree frog, Hyla crepitans (WIED-NEUWIED, 1824), from Venezuela was foundbeing handicapped by epidermal cysts of about 5 mm diameter on both inner fingers. A microbiological examination of the cyst contents demonstrated one germ only, | the bacterium Weeksella virosa (HOLMES et al. 1987). These aerobic, gram negative, Pseudomonas-related rods are ubiquitous, soil and water inhabiting bacteria which are known as opportunistically behaving infectious agent of immunosuppressed or traumatic vertebrates leading to sepsis. Additionally, an ability exists to colonise cysts and, probably, to form necrotic foci in the epithelium of anura which are not obviously immunodeficient. |
Salmonella are Gram-negative bacteria thou and thus they are no parasites sensu stricto. Nevertheless they are very common inhabitants of reptile intestinum and they have been found to cause infectious diseases in some cases. As we have addressed the issue of the significance of infections with salmonella in exotic pets in detail here some abstracts of our papers.
Salmonella infestations
Hassl libello quinto membranarum bacteriorum causa
Hygienic evaluation of terraria inhabited by amphibians and reptiles: cryptosporidia, free-living amebas, salmonella. |
Amphibians and reptiles are popular pet animals in about 90.000 Austrian households despite their frequently debated capacity to transmit diseases associated with animal keeping. We studied the epidemiological significance of the triangle animal keeper, exotic pet animal, and feed mice by investigating the frequency of three intestinal infestations, caused by cryptosporidia, opportunistic free-living amebas and salmonella, in amphibians and reptiles living in a public vivarium. In addition to recording the first known occurrence of Naegleria australiensis in Austria, and of this species and of Acanthamoeba polyphaga in the feces of reptiles worldwide, | we also detected a strong association between Salmonella subspecies I and captive reptiles and between S. subspecies III and free-living lizards. Thus, animal keeper, the exotic animals kept, and the feed mice may constitute an epidemiological pool for the interchange of these infectious agents. This new epidemiological situation may cause an increase of some opportunistic and exotic diseases such as reptile-borne salmonellosis. Despite the perceived benefits of keeping exotic animals in a household, the general public and especially those who have an immunodeficiency must be made aware of the danger of infectious diseases possibly being spread by their pets. |
fluke infestations
Hassl libello quinto operis animalum causa
A case of a facultative life-cycle diversification in the fluke Pleurogenoides sp. (Lecithodendriidae, Plagiorchiida. |
Numerous specimens of the native, intestinal digenean fluke Pleurogenoides sp. (Lecithoden-driidae, Plagiorchiida), a genus known for the simultaneous co-existence of genuine adults and progenetic, adult-like metacercaria, were found by chance parasitizing in the oesophagus of a recently imported, tropical Bristly Bush Viper (Atheris hispida). The snake had before been force-fed with native water frogs, the assumed definitive host of these flukes. Hence wa-ter frogs act as the second intermediate host or as a paratenic host for Pleurogenoides flukes, as they must house progenetic fluke larvae, which develop to genuine adults when transmitted to an appropriate consecutive host, the ancestral definitive host, a reptile. |  The European Pleurogenoides fluke species seem to display a facultative life-cycle diversifi-cation, they can adjust their life-history strategy according to their immediate transmission opportunities. This phenotypic plasticity allows the parasite to respond quickly to any changes in the abundance of a host; usually this biological oddity results in a life-cycle truncation by the elimination of the definitive host. |
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