Refinar búsqueda
Resultados 1-4 de 4
Wildlife population control – reproductive physiology under the influence of contraceptive methods in mammalian wildlife, with emphasis on immunocontraception: the best choice? A literature review
2018
Derek Andrew Rosenfield | Cristiane Schilbach Pizzutto
Human-wildlife conflicts, a growing and sad reality worldwide, makes population control of wildlife and feral animals one of the biggest challenges in wildlife management, especially due to the rapidly expanding human population, and consequently the ever-diminishing natural habitats of animals. Human activities and the destruction of nature forcing wildlife to move inevitably into urban and agricultural areas, causing “conflicts”, such as the risk of zoonosis and traffic accidents, as well as damage to crops in the search for food, whose losses reach millions of dollars. For decades, science has been engaged in extensive efforts to develop methods of “humane” population control methods, and many techniques are being employed in order to control wildlife population. In this article, we present an overview of applied contraceptive methods with simplified graphic demonstrations of their interactions with reproductive physiology, furthermore relating pro and contra of utilized antifertility agents. These are being compared to a set of desired characteristics for free-ranging wildlife for in-field applications, with emphasis on reversible immunocontraception – concluding, therefore, the reasons why this concept is becoming the most appropriate and promising for free-ranging wildlife.
Mostrar más [+] Menos [-]Cloning and expression of NS3 gene of Pakistani isolate type 2 dengue virus
2018
Yasmin, Farkhanda | Yaqub, Tahir | Idrees, Muhammad | Shahzad, Wasim | Hashmi, Abu Saeed | Aqil, Kiran | Mukhtar, Nadia | Zahoor, Muhammad Yasir | Akhtar, Naeem | Umar, Sajid
Dengue is one of the major emerging viral diseases in the world, with dramatic increases in reported cases in the last few decades and annual worldwide occurrence of approximately 390 million infections. It is a highly important mosquito-vectored disease and is a problem in tropical and subtropical areas of the world. The major aim of this study was to clone and express the dengue NS3 gene, in service to its therapeutic importance for the development of stable cell lines. Blood samples from dengue fever (DF) patients were collected and subjected to PCR amplification of the NS3 gene of dengue virus serotype-2 (DENV-2). The NS3 gene was amplified using gene specific primers and cloned in the TA cloning vectors. The gene was successfully expressed in mammalian expression vector pcDNA3.1. The current finding was different from a previously reported DENV-2 strain replicon constructed in different cells, in which the whole genetic material of the virus was used instead of an active protease gene, and which gave a low yield of replicon expressing cells. Recombinant NS3 could be used to produce an antibody that is possibly helpful for developing a single step diagnostic assay to detect the dengue virus NS3 antigen in sera of dengue patients.
Mostrar más [+] Menos [-]H9N2 avian influenza virus retained low pathogenicity after serial passage in chickens
2018
Jaqede, A. | Fu, Q. | Berhane, Y. | Lin, M. | Kumar, A. | Guan, J.
The H9N2 strains of avian influenza viruses (AIVs) circulate worldwide in poultry and cause sporadic infection in humans. To better understand the evolution of these viruses while circulating in poultry, an H9N2 chicken isolate was passaged 19 times in chickens via aerosol inoculation. Whole-genome sequencing showed that the viruses from the initial stock and those after the 8th and 19th passages (P0, P8, and P19) all had the same monobasic cleavage site in the hemagglutinin (HA), typical for viruses of low pathogenicity. However, at position 226 of the HA protein the ratio of glutamine (which favors avian-type receptor binding) to leucine (which favors mammalian-type receptor binding) decreased from 54:46 in P0, to 87:13 in P8, and then 0:100 in P19. In chickens exposed to aerosols of P0, P8, or P19, replication of the viruses was similar and mainly limited to the respiratory tract. None of the infected chickens showed any clinical signs. Over the 19 passages the viruses maintained relatively stable infectivity but gradually lost lethality to chicken embryos. According to the hemagglutination inactivation assay, P8 was slightly and P19 significantly (P < 0.05) less thermostable than P0. Collectively, after 19 passages in chickens the H9N2 AIVs retained low pathogenicity with a positive selection of L226 in the HA. These findings suggest that H9N2 viruses might acquire mammalian specificity after asymptomatic circulation in avian species.
Mostrar más [+] Menos [-]Chromobacterium violaceum infection in two blackhanded Gibbons: a veterinary case report
2018
Azman Shah A. M. | Faez Firdaus Abdullah Jesse | Tuba Thabitah A. T. | Mariani R. | Donny, Y | M. Firdaus Ariff A. R. | Simaa N. A. | Rahmat T.
Chromobacterium violaceum is a facultative anaerobic, gram-negative rodshaped bacteria normally found in soil and stagnant water of tropical and subtropical countries. Infections of Chromobacterium violaceum are rare among mammals, but the first human infection were reported in Malaysia in 1927. This clinical case reports two separate cases of Chromobacterium violaceum infection in two sub-adult male Black-handed Gibbon (Hylobates agilis). Both animals were presented with the history of diarrhea, pyrexia and inappetance. From the physical examination, the findings were high body temperature, dull, inactive, soft fecal stained at the rectum and small open wound at lower limb of one of the case. The treatment given was antipyretic and multivitamin. Unfortunately, due to poor prognosis both patients died within 48 hours after presentation and treatment. Autopsy examinations wereperformed to find out the cause of death. Post mortem examination findings revealed hepatomegaly with multiple size whitish-yellow spots on the liver surface, congestion and enlargement of spleen and lymph node, congestion of lung and loss of demarcation between renal cortex and medulla of the kidney. The cellular changes via histopathological findings of kidney, spleen, lung and liver were suggestive of septicaemia. The gross and histopathologicalfindings were supported by the isolation of Chromobacterium violaceum via bacterial isolation and identification from lung, liver, spleen and kidney. Thus, the cause of death of the two sub-adult male Black-handed gibbon in this case are due to septicaemiadue to Chromobacterium violaceum infection.
Mostrar más [+] Menos [-]