La lutte contre les insectes forestiers au moyen de pulvérisations à ultra-bas volume (ULV)

La pulvérisation à ultra-bas volume de formulations spéciales de concentrés d'insecticides, à partir d'atomiseurs ou d'avions et hélicoptères équipés de buses spéciales ou d'éléments rotatifs, présente de nombreux avantages d'ordre économique qui sont spécialement appréciés en sylviculture. De 1967 à 1969 des essais de lutte à l'aide de concentrés ULV de malathion, de diméthoate et de bromophoséthyle ont permis d'obtenir de bons résultats; des pulvérisateurs portatifs à moteur ont été employés ainsi qu'un hélicoptère pour l'épandage du malathion à 1.500 cm²/ha contre les larves de Coleophora laricella (Hb.).     

Use of topical selamectin for the treatment of Syphacia muris infection in laboratory rats

Efficacy of selamectin was studied in naturally acquired S. muris infections in rats. Fourty-eight S. muris-positive rats were divided into six treated and two control groups. Selamectin (6 mg/kg) was applied topically to the skin in a single spot at the base of the neck in the treatment group. The rats of treated and control groups were necropsied on the 24th day after the treatment. Topical selamectin was found to be 40.7-63.3% effective (based on egg per gram method) in eliminating S. muris infection in rats. The efficacy of the treatment against S. muris (based on adult worm counts) in male and female rats was 35.14-58.88%, respectively (mean 48.39%).     

Use of topical selamectin for the treatment of Trichosomoides crassicauda infection in laboratory rats

The present study investigated the efficacy of topical selamectin for elimination of naturally acquired Trichosomoides crassicauda infection in rats. Twelve T. crassicauda-positive rats were assigned to the treatment group and six rats were assigned to the control group. Selamectin (6 mg/kg) was applied topically to the skin in a single spot at the base of the neck in front of the scapulae in the treatment group. To assess the efficacy of the treatment, animal faeces were investigated with the use of the flotation technique on days 0, 4, 14 and 24 after selamectin application. The rats of the treatment and control groups were necropsied on the day 24. In the treatment group, 7 of 12 infected rats were cured completely. Topical selamectin was found to be effective in eliminating T. crassicauda infection in rats.     

Virulence factors and antimicrobial susceptibility of Escherichia coli isolated from calves in Turkey

Escherichia coli isolates from calves were investigated by multiplex PCR assays for the presence of genes encoding K99, F41, F17-related fimbriae, heat-stabile enterotoxin a (STa), intimin (eae) and Shiga toxins (stx1 and stx2). A total of 120 E. coli isolates, 75 isolated from diarrhoeic or septicemic calves and 45 from clinically healthy calves aged between 1 day and 2 months were tested. Each isolate was obtained from different calves in different herds. Among the isolates from diseased animals, 12 (16%) isolates from 1- to 7-day-old diarrhoeic calves were detected as enterotoxigenic E. coli which possessed K99, F41 and STa in combination; F17-related fimbriae genes were detected in 33 (44%) isolates and they were found in combination with K99 + F41 + STa in two isolates. Of 120 isolates, 16 carried eae, eight stx1 and five stx2 genes alone or in combination. None of the eae- or stx-positive strains was identified as O157:H7. However, results indicate that calves may be carrier of Shiga toxin-producing E. coli which have potential as a human pathogen. Antimicrobial susceptibility of 75 isolates from diseased calves was determined by agar disk diffusion method for 14 antimicrobial agents. In 77.3% of the isolates, multiresistance was detected. Higher resistance rates were detected for cephalothin (72%), tetracycline (69.3%), kanamycin (69.3%), ampicillin (65.3%), nalidixic acid (53.3%), trimethoprim-sulphamethoxazole (52%) and enrofloxacin (41.3%), respectively. No resistance was found for ceftiofur and cefoxitin.     

Chlamydophila psittaci infections in humans during an outbreak of psittacosis from poultry in Germany

In 2005, an outbreak of severe respiratory disease in a mixed poultry flock that was infected with Chlamydophila (C.) psittaci led to dissemination of the infection to at least 100 small poultry farms in 11 districts of Central Germany. At the same time, a total of 24 persons in contact with poultry from one of the flocks reported flu-like symptoms to their physician, thus suggesting zoonotic transmission. Within 3 weeks, seven individuals had to be hospitalized, with three of them requiring intensive care. Analysis of ompA sequences from chlamydial isolates and directly from clinical samples revealed the presence of both genotype A and E/B of C. psittaci at the source of the outbreak and in contact flocks. Genotype A was also detected in the three severely ill patients. The findings of the present study demonstrate the high zoonotic potential of avian chlamydiae. To ensure speedy eradication of psittacosis in poultry flocks and effective treatment of infected humans, fast, sensitive and species-specific detection of the causative agent is essential, as well as close collaboration between regional public health services, attending physicians and the diagnostic laboratories involved.     

Substitution of vaccinia virus Elstree by modified vaccinia virus Ankara to test the virucidal efficacy of chemical disinfectants

After the eradication of variola in 1980, the smallpox vaccination was considered to be no longer required and was subsequently abandoned mainly because of possible adverse effects of vaccinia virus especially in first‐time vaccinees. Despite a growing number of humans without immunity against vaccinia virus, vaccinia virus Lister Elstree (VACV) is still prescribed for testing virucidal efficacy of chemical disinfectants in the guidelines of the German Veterinary Medical Society [Deutsche Veterinärmedizinische Gesellschaft (DVG)], the German Association for the Control of Virus Diseases [Deutsche Vereinigung zur Bekämpfung der Viruskrankheiten (DVV)] and the Robert Koch Institute (RKI). To evaluate a possible substitution of VACV, with the attenuated modified vaccinia virus Ankara (MVA) the virucidal efficacy of four different DVG‐listed commercially available chemical disinfectants representing different groups of chemicals was tested against these two viruses. Quantitative suspension tests and qualitative carrier tests with poplar wood and gauze were performed. Distinction of VACV and MVA was confirmed by cytopathogenic effects, such as differences in plaque morphology. No significant difference in disinfection efficacy between VACV and MVA was observed for any of the disinfectants tested. Implying that vaccinia virus poses a risk after inadvertent inoculation, our results show that MVA, which does not replicate in humans, should replace VACV in the chemical disinfectant testing guidelines.     

Genetic structure of the Amur tiger (Panthera tigris altaica) population: Are tigers in Sikhote‐Alin and southwest Primorye truly isolated?

We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far East. We identified 63 individuals after genotyping 256 feces, 7 hair and 11 blood samples collected within southern, central and northern Sikhote‐Alin, as well as Southwest Primorye. Analysis of nuclear DNA at 9 microsatellite loci demonstrated greater genetic similarity between animals from southern and northern Sikhote‐Alin (some 500 km apart) than between animals from Ussuriskii State Nature Reserve and Southwest Primorye (less than 10 km apart at their nearest point), suggesting that a true barrier exists preventing movements of tigers between Southwest Primorye and the southern Sikhote‐Alin Mountains.