从害虫马尾松毛虫中提取甲壳素的初步研究

采用酸碱法对马尾松毛虫蛹中甲壳素的提取方法进行了初步研究。重点分析了N aOH不同处理条件对脱有机物质和甲壳素产率的影响,确定了从马尾松毛虫蛹中提取甲壳素的基本工艺:(1)脱矿物质:盐酸浓度为2.5%,浸泡时间为20 h,浸泡温度为30℃;(2)脱有机物质:N aOH浓度为6%,浸泡温度为75℃,浸泡时间为10 h;(3)脱色:双氧水浓度为9%,浸泡时间为2.5 h,浸泡温度为80℃。在此条件下,获得的甲壳素产品为白色粉状固体,其N含量为6.87%,灰分为1.19%,水分为8.37%。产率为29.97%。产品的N含量达到食品级甲壳素标准,灰分含量达到工业级甲壳素标准。实验有助于后续深入研究马尾松毛虫蛹中甲壳素的提取,也为今后进一步制备虫蛹壳聚糖打下了基础。     

A survey of gastrointestinal helminths in cats of the metropolitan region of Rio de Janeiro, Brazil

The prevalence of gastrointestinal helminth parasites in 135 cats over 1 year of age and inhabiting the metropolitan region of the city of Rio de Janeiro, Brazil was investigated by necropsy. These animals had two distinct origins: 99 cats (29 males and 70 females) were derived by capture in public areas (feral/stray) and 36 (12 males and 24 females) from shelters. The overall prevalence of gastrointestinal helminth parasites was 89.6%. The following parasites, with their respective prevalence in parenthesis, were found: Dipylidium caninum (52.6%), Ancylostoma braziliense (65.9%), Ancylostoma tubaeforme (8.9%), Toxocara cati (25.2%), Toxascaris leonina (11.9%), Physaloptera praeputialis (9.6%). Concurrent infections with two or more parasites were recorded in 59.5% of the individuals. Of the 121 parasitized cats, 94 were feral/strays and 27 were from shelters. Among feral/stray cats, 80 were infected with A. braziliense (85%) and 17 of the shelter felids were infected with D. caninum (63%). Feral/stray cats had higher worm intensities (6411/94-68.2) than shelter cats (992/27-36.7). The helminth parasites most frequently found in feral/stray cats were Ancylostoma braziliense (47.5%) and D. caninum (47%) while in shelter cats, D. caninum was the predominant species (85.2%). Twenty seven cats (22.3%) had only A. braziliense and 19 (15.7%) were parasitized only with D. caninum. Among those cats harboring mixed infections A. braziliense and D. caninum were the species more frequently found (P < 0.001).     

Effect of a Single Dose of Cadmium on Pregnant Wistar Rats and their Offspring

Cadmium (Cd) is a well‐known toxicant targeting many organs, among them placenta. This heavy metal also has embryonary and foetal toxicity. This study was undertaken to analyse the effect of a single Cd dose administered at 4, 7, 10 or 15 days of gestation on the offspring of pregnant rats sacrificed at 20 days of gestation. Cadmium chloride was administered subcutaneously at 10 mg/kg body weight to Wistar pregnant dams; control animals received a proportionate volume of sterile normal saline by the same route. Maternal uteri, livers, kidneys and lungs, and foetuses were examined at necropsy. Samples of maternal organs and whole foetuses were collected for histopathologic examination, determination of Cd levels and staining by the Alizarin red S technique. Results revealed a clear embryotoxic and a teratogenic effect of this heavy metal, the former as a significant increase in the number of resorptions, and the latter as significant decrease of the gestational sac weight, and the size and weight of foetuses of Cd‐treated dams as well as induced malformations in skull bones, vertebrae and thoracic, and pelvian limbs. The deleterious effects found were similar to those previously reported for other animal models suggesting a high conservation of the pathogenic mechanisms of Cd. Additionally, many of the addressed aspects showed a slight dependence on the time of administration of the toxic that might be due to the accumulation of the metal in different organs, as we were able to demonstrate by the analysis of its concentration.     

Cochliomyia hominivorax myiasis in a colony of stray cats (Felis catus Linnaeus, 1758) in Rio de Janeiro, RJ

Cochliomyia hominivorax infestation in domestic cats of an urban colony in the city of Rio de Janeiro is described. The overall prevalence over the period 2001-2005 was 12.5%. Only adult cats were found infested and among these, most cases were observed in males (28%) (p < or = 0.05). The most frequently infested areas of the cats' bodies were the face and nape of the neck. Most lesions were found on the front part of the body of adult males (80%), suggesting that myiasis occur in consequence of competitive fighting wounds.     

Genomic Typing of Canine Parvovirus Circulating in the State of Rio de Janeiro,Brazil from 1995 to 2001 Using Polymerase Chain Reaction Assay

In this study, the genomic types of canine parvovirus (CPV) circulating in the State of Rio de Janeiro, Brazil, from 1995 to 2001, were investigated using the polymerase chain reaction assay (PCR). A total of 78 faecal samples from gastroenteritic puppies, confirmed as positive for canine parvovirus by haemagglutination/haemagglutination inhibition tests or virus isolation in cell culture (MDCK), were examined. The viral DNA was extracted from faecal samples using a combination of phenol– chloroform and silica–guanidine thiocyanate methods. PCR was carried out with differential pairs of primers to distinguish the old (CPV-2) and new types of virus (CPv-2a or CPV-2b). Specific amplicons were observed for all samples using the primer pair P2ab, which detects CPV-2a and CPV-2b. Seventy-six from a total of 78 samples (97%) were considered as CPV-2b because of their reaction with the primer pair P2b. Thirty samples (30/78) were from previously vaccinated puppies and in 15 of them the enteritis symptoms began from 1 to 12 days after vaccination. PCR confirmed the infection by wild virus (CPV-2b) in 5 of these 15 puppies who had received old-type vaccines. Our results show that CPV-2b was the prevalent type circulating in the State of Rio de Janeiro from 1995 to 2001.     

Monitoring of canine parvovirus (CPV) strains detected in vaccinated puppies in Brazil

The objective of this study was to investigate, by partial sequencing of VP2 protein, the variability of CPV detected in 37 fecal samples collected from vaccinated puppies with enteritis. Laboratorial diagnosis of CPV was confirmed by HA/HI and PCR and, for sequencing analyses, two different regions of the VP2 gene were amplified by PCR. From 1995 to 2004, all strains were characterized as CPV-2a. After that, both CPV-2a and CPV-2b were detected. All CPV-2a showed a non-synonymous mutation in the residue 297 (Ser → Ala). A synonymous substitution at the AA 574 was also observed in 15/37 samples. Our findings indicate that the cases of vaccine failure are most likely not associated to the mutations detected in the sequenced regions. However, the monitoring of genotyping mutations that led to new CPV strains is essential to determinate if current vaccines will keep providing protection against all new future variants.     

Follow-up of the health conditions of an urban colony of free-roaming cats (Felis catus Linnaeus, 1758) in the city of Rio de Janeiro, Brazil

Similar to other urban areas where food and shelter are abundant, the zoological garden of Rio de Janeiro has dealt for years with a colony of feral or semi-feral domestic cats. A survey was conducted during 2002-2004 as a follow-up to a previous study in 2001 of the cat colony to identify pathogens circulating among the population and to annually follow the status of the cats to analyze morbidity coefficients and associations among infections and infestations identified in the colony. During the 3 years of the present study, 75 cats were sampled at least once, including 44 that were caught and examined only once, 14 that were examined twice, and 17 that were examined three times. For each cat that was caught, records were kept regarding sex, age, general health, and the presence of ectoparasites. Each year, a blood sample was taken for hematologic testing, platelet count, hemoparasite detection, antibodies to Toxoplasma gondii, and retrovirus detection. Blood counts were within normal range for the majority of cats tested. Feline immunodeficiency virus, fleas, and lice were detected in all years; however, incidence rates for each of these varied significantly throughout the years. Prevalence of Cytauxzoon spp., Mycoplasma spp., T. gondii infections were variable among the 3 years, although differences were not significant. Prevalence of feline leukemia virus increased significantly over the 3 years. Mycoplasma spp. and flea infestations were significantly associated, but no other associations among the pathogens were detected. Over the 3 years, the rate of new cat introductions decreased, and the pathogens showed a tendency to disseminate throughout the colony; however, there was virtually no evidence of clinically detectable disease. Therefore, it seems that stabilizing the population by a judicious control program facilitated the distribution of the pathogens throughout the colony, while the general well-being of the cats was not seriously affected.     

Prevalence of Bartonella species DNA and antibodies in cats (Felis catus) submitted to a spay/neuter program in Rio de Janeiro, Brazil

The prevalence of Bartonella species DNA and antibodies for Bartonella henselae were studied in 40 clinically healthy cats (Felis catus, Linnaeus 1758) submitted to a spay/neuter program in Rio de Janeiro, Brazil. Additionally, the prevalence of Bartonella species DNA was investigated in the fleas found parasitizing the subject cats. For this purpose, blood samples were obtained from all cats, and DNA extraction was performed on the blood, and blood clotted samples, as well as on pools of fleas obtained from them. Antibodies for B henselae were detected on serum samples. Bartonella species DNA was detected in 17 cats, whereas serum reactivity for B henselae was found in 19. A total of 20 cats were flea-infested and nine of these 20 had Bartonella species DNA in their blood. In four of the 20 flea-infested cats, Bartonella species DNA was detected in the fleas obtained from those cats, but only one of these four cats had Bartonella species DNA in its blood.     

Reduction of feral cat (Felis catus Linnaeus 1758) colony size following hysterectomy of adult female cats

The size of urban cat colonies is limited only by the availability of food and shelter; therefore, their population growth challenges all known population control programs. To test a new population control method, a free-roaming feral cat colony at the Zoological Park in the city of Rio de Janeiro was studied, beginning in 2001. The novel method consisted of performing a hysterectomy on all captured female cats over 6 months of age. To estimate the size of the colony and compare population from year to year, a method of capture-mark-release-recapture was used. The aim was to capture as many individuals as possible, including cats of all ages and gender to estimate numbers of cats in all population categories. Results indicated that the feral cat population remained constant from 2001 to 2004. From 2004 to 2008, the hysterectomy program and population estimates were performed every other year (2006 and 2008). The population was estimated to be 40 cats in 2004, 26 in 2006, and 17 cats in 2008. Although pathogens tend to infect more individuals as the population grows older and maintains natural behavior, these results show that free-roaming feral cat colonies could have their population controlled by a biannual program that focuses on hysterectomy of sexually active female cats.