Prevalence and serotyping of Listeria monocytogenes in Portuguese live bivalve molluscs sampled in various steps along the sanitary control process     

Ana Luísa Pinto  Paula Teixeira  Fernanda Castilho  Maria Teresa Felício  Filomena Pombal  & Paul A Gibbs 《Aquaculture Research》2006,37(11):1112-1116

The prevalence and contamination levels of Listeria monocytogenes were investigated in live bivalve molluscs for human consumption, collected in various steps of the commercial and sanitary circuits in the North of Portugal. Samples of different species were collected per lot before and after depuration treatment in two depuration units and further, when placed in retail markets. Listeria monocytogenes was isolated from 4% of the samples although with very low contamination levels (less than 100 MPN g^?1). None of the environmental (non‐depurated) samples were contaminated with the food‐borne pathogen. The positive samples involved depurated and commercialized samples from two lots, one in each circuit. Two serotypes (1/2a and 3b) were detected among the isolated strains. This study demonstrated the possibility of occurrence of L. monocytogenes contamination of live bivalve molluscs along the sanitary control circuit, including at the retail market level. As L. monocytogenes grows well at refrigerated temperatures and in high salt matrixes such as seafood its presence in these products should not be overlooked.  相似文献   

Use of mixed feeding schedules in fish culture: field trials on catla, Catla catla (Hamilton-Buchanan), rohu, Labeo rohita (Hamilton), and common carp, Cyprinus carpio L.     

M. C. NANDEESHA  S. S. DE  SILVA D. KRISHNA MURTHY  K. DATHATRI 《Aquaculture Research》1994,25(6):659-670

Abstract. The applicability of mixed feeding schedules using low-and high-protein diets was evaluated by three on-farm field trials conducted in fertilized earthen ponds. Rohu, Labeo rohita (Hamilton), and common carp, Cyprinus carpio L., were used in the first two trials, and catla. Catla catla (Hamilton-Buchanan), was also included in the third trial. The concept of a mixed feeding schedule was tested using a 1:1 rice bran-groundnut meal cake mixture, a commonly used feed in Indian carp culture.
In a mixed feeding schedule, two feeds are used alternately, each for a predetermined number of days. In the present study, one of three such mixed feeding schedules was used in conjunction with one of two control diets. The control diets were rice bran (diet A) or a mixture of rice bran-groundnut meal cake (diet B). The mixed feeding schedules tested were: 1A/1B, 1A/2B and 1A/3B (numerals indicate number of days diet A or B was offered continuously). Diet A (rice bran only) induced significantly poor growth in all treatments. Interestingly, growth in the mixed feeding schedules was generally equal or superior to that when fish were fed with diet B. Growth efficiency indicators such as SGR. FCR and PER were found to be good for fish maintained on certain mixed schedules. Savings of 15–31% protein and 10–20% of the feed cost were achieved with the various schedules, the highest saving being achieved with the 1A/1B schedule. Nitrogen retention was higher in fish treated with mixed schedules. The results demonstrated the usefulness of mixed schedules in reducing nitrogen input, output and feed costs.  相似文献   

Development of monoclonal antibodies to PK'X', the causative agent of proliferative kidney disease   总被引：1，自引：0，他引：1  

A. ADAMS  R. H. RICHARDS  M. MARIN DE  MATEO 《Journal of fish diseases》1992,15(6):515-521

Abstract. Two monoclonal antibody probes were produced against PK'X' cells. The parasites were partially purified by filtration and centrifugation of kidney tissue from rainbow trout with proliferative kidney disease and used as antigen for immunization of mice. The resulting monoclonal antibodies reacted with PK'X' cell antigens in enzyme-linked immunosorbent assay and immunohistochemistry tests. One antibody (Mab 12) appeared to be specific for PK'X'in kidney tissue, while the other (Mab 18) cross-reacted with host cell antigens in the kidney tubules. These probes are invaluable tools for the investigation of parasite surface antigens and life cycle studies.  相似文献   

Decline and fall of the salmon fisheries in the Netherlands: is restocking the Rhine a reality?     

S. J. DE  GROOT 《Aquaculture Research》1992,23(2):253-264

Abstract. The Atlantic salmon, Salmo salar L., was once of major importance to the fishing industry along the River Rhine. This paper discusses the Dutch and German salmon catches over the years 1863–1950. Even up to the end of the last century, it was not uncommon for Dutch and German fishermen to land 100000 salmon a year. However, factors such as the increased use of locks and weirs along the Rhine, coupled with growth in pollution, soon led to a rapid decline in numbers. By 1933, the salmon fishing industry in the Netherlands had virtually ceased to exist. Analysis of the available catch statistics suggests that the decline in the salmon population could have started before official records began. Although the degree of scatter in the data and uncertainties in the assumptions preclude the possibility of drawing firm conclusions about the survival rate of salmon, these figures illustrate how difficult it will be to maintain a stable population in the Rhine. Moreover, a number of changes have taken place since the heyday of salmon in western Europe, which could compound the problem. Of particular importance in the context of the Rhine are:

• 1 the closure of two of the major migration routes to the sea (Haringvliet and Zuiderzee);
• 2 morphological changes in the river;
• 3 chemical and thermal pollution;
• 4 the loss of accessible spawning and nursery areas of the required quality;
• 5 the disappearance of salmon from other rivers that flow into the North Sea such as the Rivers Elbe, Weser and Ems. If salmon were only reintroduced into the Rhine, a certain proportion would probably stray and infiltrate these other rivers.

The fact that the impact of these changes is difficult to quantify increases the uncertainty associated with maintaining a stable stock of salmon in the Rhine.  相似文献   

Dietary accumulation of polychlorinated biphenyls, chlorinated pesticides and mercury by cultivated eels, Anguilla anguilla L.     

J. DE BOER  H. PIETERS 《Aquaculture Research》1991,22(3):329-334

Abstract. Polychlorinated biphenyls (PCBs), chlorinated pesticides and mercury were analysed in cultivated eels, Anguilla anguilla L., and their food. In one experiment the eels were mainly fed with a low-fat diet. In another experiment cultivated eels were fed a high-fat diet. Both experiments showed that the major part of the organochlorine compounds and mercury present in the diet was retained by the eel. The retention of the organochlorine compounds and mercury was estimated at 50–70% after an exposure period of about 1 year.
Although the mechanisms of accumulation of mercury and organochlorine compounds clearly differ, no differences in retention were found. The remaining mercury, PCBs and pesticides which were not retained possibly pass through the alimentary canal rather than being accumulated first and metabolized or excreted during the feeding period.
Due to these high levels of accumulation monitoring levels of PCBs, chlorinated pesticides and mercury in the diet is essential for protection of the quality of cultivated eels.  相似文献   

Pharmacokinetics and tissue distribution of oxytetracycline in carp, Cyprinus carpio L., following different routes of administration   总被引：4，自引：0，他引：4  

J. L. GRONDEL  J.F.M. NOUWS  M. DE  JONG A. R. SCHUTTE  F. DRIESSENS 《Journal of fish diseases》1987,10(3):153-163

Abstract. The objective of this pharmacokinetic study was to investigate absorption, distribution, elimination and bioavailability of oxytetracycline (OTC) in carp, Cyprinus carpio L ., after different routes of administration, OTC was administered intravenously (i.v.), intramuscularly (i.m.) and orally at 60 mg/kg body weight. OTC levels were determined in plasma and several tissues. Analysis of the plasma drug concentration-time curves following i.v. OTC injection revealed three distinct phases. A three-compartment open model was used to derive pharmacokinetic parameters. Compared to mammals, a very extended final elimination half-life was observed (139.8±38.1 h). Following i.m. OTC administration, C_max was 56.8±10.9μg OTC/ml at 14 h post-injection. The Vd area was 2.1 ± 0.66 1/kg. Extreme differences were observed with respect to bioavailability following i.m. and oral administration; approximately 80 and 0.6%, respectively. Following i.m. injection tissue OTC determinations revealed that the drug was accumulating in pronephros, bone tissue and scales. After 21 days the OTC concentrations were 2.9±0.8, 5.2±0.3 and 4.7±3.1 μg/ ml, respectively. In tissue samples from the dorsal region (muscle), including the injection site, OTC could not be demonstrated at that time. The pharmacokinetic data are discussed in relation to the susceptibility of the immune system of fish for modulation.  相似文献   

Atlantic salmon, Salmo salar L., stock discrimination by scale-shape analysis     

H. DE  PONTUAL P. PROUZET 《Aquaculture Research》1987,18(3):277-289

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Exploratory analysis of differences in sperm morphology in Nelore and Gir (Bos indicus) bulls     

Aline Costa de Lucio  Antonio Sérgio Ferraudo  Leticia Zoccolaro de Oliveira  Adriana Santana do Carmo  Benner Geraldo Alves  Kele Amaral Alves  Solange Almeida  Luis Alfredo Deragon  William Pereira  Luisa Cunha Carneiro  Vera Fernanda Martins Hossepian de Lima 《Tropical animal health and production》2014,46(5):765-770

The aim of this study was to evaluate the effects of breed and season on semen quality parameters of zebu bulls. Data (1,632 registers) of semen production from Gir (n?=?4) and Nelore (n?=?15) bulls were collected between October 2005 and November 2009. The ejaculates were collected twice a week during various seasons (summer, fall, winter, and spring) and evaluated for the following semen parameters: ejaculate volume, sperm concentration, sperm motility, forward progressive motility (FPM), and sperm morphology. Factor analysis was used to determine the relationship among variables. The effect of breed (Gir and Nelore) and season and their cross effect on each parameter and extracted factor were tested using ANOVA. A negative correlation (P?<?0.05) was observed between FPM and proximal droplet, as well as with abnormal loose head, abnormal small head, pouch formation, abnormal mid-peace, and strongly folded tail. Gir bull sperm showed more major defects, detached acrosome, and minor FPM (P?<?0.01), whereas Nelore bulls showed a higher number of sperm with normally loose head.  相似文献   

Does Rhipicephalus microplus tick infestation increase the risk for myiasis caused by Cochliomyia hominivorax in cattle?     

José Reck  Fernanda S. Marks  Rogério O. Rodrigues  Ugo A. Souza  Anelise Webster  Romário C. Leite  João Carlos Gonzales  Guilherme M. Klafke  João Ricardo Martins 《Preventive veterinary medicine》2014

The larval phase of Cochliomyia hominivorax (screwworm) is an obligate parasite of vertebrate animals, particularly mammals, and widespread in South America, where it remains one of the most important parasitic diseases of domestic animals. The skin of cattle highly infested by ticks, with cutaneous lesions, exudation of tissue fluid and blood scent seems to produce the ideal environment for fly attraction. However, an association between these parasites was never investigated. The aim of this work was to verify if there is an association between Rhipicephalus microplus tick load and the occurrence of C. hominivorax myiasis in cattle, and to quantify the risk. Sixty bovine (Bos taurus taurus, Angus breed) under field conditions were observed for 24 weeks, during which weekly tick counts and examination for the presence of myiasis were performed. There was a significant association between a high tick burden (24-week mean above 50 ticks per animal) and myiasis occurrence (P = 0.0102). The calculated relative risk (RR) for C. hominivorax myiasis occurrence in cattle with high tick burden was 3.85 (CI95% = 1.23–12.13); indicating that cattle highly parasitized by R. microplus have about four times more risk of myiasis than those with a low parasite load. As far as we aware, this is the first statistically based evidence of the relationship between R. microplus parasitic load and occurrence of myiasis by C. hominivorax. This result could be useful for the design of integrated control strategies for these parasites and to provide more information for the understanding of cattle tick parasitism in cattle production.  相似文献   

Immunogenicity of a Recombinant Mycobacterium smegmatis Vaccine Expressing the Fusion Protein CMX in Cattle from Goiás State, Brazil     

Duanne ALVES DA SILVA  Marcos Ant?nio Rocha CAVALCANTI  Fábio MUNIZ DE OLIVEIRA  Monalisa Martins TRENTINI  Ana Paula JUNQUEIRA-KIPNIS  André KIPNIS 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(7):977-984

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