Retrospective and longitudinal study of salmonellosis in captive wildlife in Trinidad

Morbidity and mortality of captive wildlife at the Emperor Valley Zoo, Trinidad from 1993 to 1996 were analysed to determine involvement of Salmonella spp. A 6 mo longitudinal study was conducted to determine the frequency of isolation of Salmonella spp. from apparently healthy, sick and dead wild mammals, birds, and reptiles. The antibiograms of Salmonella isolates were determined using the disc diffusion method. Fecal samples randomly selected from animal enclosures and cloacal swabs of snakes were cultured for Salmonella spp. following enrichment in tetrathionate and selenite cystine broths. For the 1993-96 period, Salmonella spp. was implicated in 17 (12%) of 141 sick or dead animals and the predominant serotype was S. typhimurium. During the 6 mo prospective study in a mean animal population of 1,186, there were 20 (2%) and 14 (1%) animals that were sick and died respectively; Salmonella spp. was implicated in only one mortality. Overall, of 1,012 samples from apparently healthy wildlife cultured, 66 (7%) yielded 24 serotypes of Salmonella. The predominant serotype were S. seigburg (16 isolates), S. gaminara (6 isolates), and S. thompson (6 isolates). None of the samples yielded S. typhimurium. The frequency of isolation of Salmonella spp. in reptiles (14%) was significantly higher than found in either mammals (7%) or birds (3%). Sixty-five (99%) of 66 Salmonella spp. isolates exhibited resistance to one or more of the nine antimicrobial agents tested. Resistance was high to cephalothin (92%), moderate to streptomycin (35%) and tetracycline (29%), but significantly low to gentamicin (2%), chloramphenicol (0%), and sulphamethoxazole/trimethoprim (0%). The prevalence of asymptomatic infections by Salmonella spp. in zoo animals was high and the very high prevalence of antimicrobial resistance could be a problem when treating salmonellosis.

Absence of Escherichia coli 0157 in a survey of wildlife from Trinidad and Tobago

Fecal, cloacal, or rectal swabs of free-ranging and captive mammalian and avian wildlife in Trinidad and Tobago were cultured for non-sorbitol fermenting Escherichia coli and tested for 0157: H7 strains. Ability of E. coli strains to produce hemolysin and mucoid colonies also was investigated. Of 271 free-ranging mammals tested, 158 (58 percent) yielded E. coli; only one (< 1 percent) bacterial isolate was a non-sorbitol fermenter which was not agglutinated by 0157 antiserum. All isolates were negative for hemolysin production and mucoid colonial growth. Two hundred and sixty-three (90 percent) of 293 free-flying birds were positive for E. coli and all isolates were sorbitol fermenters and negative for production of hemolysin and mucoid growth. Of 175 captive wild animals from individual backyard farms and a government demonstration farm, 145 (83 percent) yielded E. coli with four (2 percent) non-sorbitol fermenters; all were negative for 0157 strains, hemolysin production, and mucoid colonial growth. Of 373 animals in a zoo, 250 (67 percent) were positive for E. coli with only two (0.5 percent) non-sorbitol fermenters. All strains were non-hemolytic and non-mucoid farms. It appears that free-ranging and captive avian and mammalian wildlife are not important reservoirs of 0157: H7 stains of E. coli in Trinidad and Tobago.(AU)

Regional differences during cerebellar corticogenesis in the rhesus monkey - abstract

This study was undertaken to gain more insight into the complex morphology of the mammalian cerebellum. Investigators of earlier days who attempted to elucidate the fundamental organization of the cerebellum were mainly occupied with the gross morphology of its lobes and fissures, and this closed the eyes initially to other principles of organization. Recent anatomical and electrophysiological studies, however, have increasingly raised support for the concept of a fundamental division of the cerebellum into 4 longitudinal zones with their subdivisions, rather than into transverse lobes and lobules. These zones are based on the compartmentilization of certain afferent and efferent fiber systems of the adult cerebellum. Studies of the development to the cerebellum in a few mammals and man, also revealed the existence of a transient zonal pattern. The latter, however, is based on the temporary clustering of Purkinje cell neuroblasts in the cortical anlage. In the rhesus monkey this period lasts from d.48 until d/80. Horizontal and frontal serial sections of each age were available. The first indication of regional differences is noted on d.50. Between d.54 and d.65 the clusters become increasingly clear and it is possible to distinguish them individually. As development progresses, the clusters are gradually transformed into a Purkinje cell monolayer, which is apparent around d.80. It is highly probable that before it fades away, the embryonic zonal pattern acts as the mould for the permanent adult pattern (AU)

The neck region of the spermatozoon of discus rotundatus (muller) (pulmonata, stylommatophora)

The neck region of the mature spermatozoon of discus rotundatus is described. No evidence for a centriole or centriolar derivative is obtained. Nine striated coarse fibres and the two central fibres of the axoneme extend into the base of the implantation fossa. The axonemal doublet system is disrupted in the neck region. There are two fibrous acessory structures located between the central doublet and the striated coarse fibres (AU)

Arbovirus studies in Bush Bush Forest, Trinidad, W.I., September 1959-December 1964. II. Field program and techniques

The field program of the Trinidad Regional Virus Laboratory in Bush Bush Forest included studies in which arboviruses (their prevalence and epidemiology) were the chief interest and also studies on the biology of the arthropods and vertebrates possibly associated with arbovirus cycles. The techniques used included the exposure of sentinel animals, trapping and bleeding of small mammals and reptiles, netting and bleeding of birds, collection of bloodsucking arthropods, and observations on the diel- and seasonal-activity patterns, food sources, and habitat preferences of the more abundant species of mosquitoes.(AU)

Observations on a zoonosis: leishmaniasis in British Honduras

More than 1600 mammals were examined for infections of Leishmania mexicana. Fourteen infected rats belonging to three species were trapped. A fourth species was experimentally infected. More than 3000 sandflies attracted to rats and oppusums are recorded, principal species being Lutzomyia cruciata, L.flaviscutellata, L. panamensis, L. shannoni, L.permira and L. trinidadensis. More than 2000 sandflies were dissected and flagellates found in twelve. Three strains from L. flaviscutellata proved to be infections of Leishmania mexicana. Many observations on the ecology of the rats and the sandflies are presented and discussed. It is concluded, in the light of the ecological observations, that the rat Ototylomys phyllotis is the principal reservoir host and the fly Lutzomyia flaviscutellata is the principal vector of Leishmania mexicana in British Honduras (Summary)