Clonality of Enterococcus faecalis associated with amyloid arthropathy in chickens evaluated by multilocus sequence typing (MLST)

The aim of the study was to evaluate the clonality of 21 strains of Enterococcus faecalis associated with arthritis and amyloid arthropathy by multilocus sequence typing (MLST). The strains originated from five countries. Fifteen of the 21 strains demonstrated the same sequence type, ST82, including a reference amyloid arthropathy strain from the Netherlands. Some of the demonstrated sequence types (ST36, ST59 and ST82) have also been described from human clinical samples while other types are reported for the first time. The results confirm previous observations that outbreaks of amyloid arthropathy seem to be clonally related and indicate a wide distribution of the predominant sequence type which was demonstrated in four countries in Europe and in the USA.     

Ecology, history and silviculture of Scots pine (Pinus sylvestris L.) in western Norway - a literature review

Results from a literature review on pinewood ecology, silviculture,genetics, aspects of history and forest resources of Scots pine(Pinus sylvestris L.) in western Norway are presented. The pinewoodscover 40 per cent of the forested land, 0.31 million ha. Duringthe last 75 years, the area has increased by 17 per cent andthe growing stock has risen from 10 to 34 million m³. The impactof man in previous times was very marked, and has had a significantinfluence on the present forest conditions. The pronounced climaticgradients mixed with the topographic variation – fromthe coastal plains via the fjord systems to the high mountains– is reflected in rather steep gradients in the pine forestvegetation. Various floristic elements can be distinguished,from oceanic via the suboceanic in the outer islands to thethermophytic, boreonemoral and boreal elements in the innerfjord districts and valleys. The introduction of spruce (Piceaspp.) plantations on 10–15 per cent of former native pineforests has not negatively affected the bird fauna at the landscapescale. Although not particular species rich, the pine forestsharbour species usually not found in other forest types. Sofar, most work in the field of silviculture and forest ecologyin the pinewoods of West Norway has been in the form of casestudies. Implications of the results for forestry in the regionare briefly discussed.     

Pasteurella multocida infection in heterophil-depleted chickens

The present study was aimed at elucidating the role of heterophil granulocytes during the initial infection with Pasteurella multocida subsp. multocida in chickens. Chickens (17 and 19 wk old) were depleted of their heterophil granulocytes by 5-fluorouracil treatment. When the heterophil blood counts were significantly reduced, the birds were inoculated intratracheally with 1.8-4.3 x 10(4) colony-forming units of P. multocida. Twelve, 24, or 48 hr postinoculation, the birds were euthanatized and examined for macroscopic and histologic lesions in the lungs. Bacterial invasion was determined by culture of P. multocida from the spleen. Recruitment of heterophils into the respiratory tract during infection was found to contribute considerably to the lung lesions in chickens and was found to mediate tissue damage, possibly allowing a more rapid systemic spread of P. multocida. However, during progression of the infection, the heterophil-mediated necrosis in chickens seemed to stimulate giant cell demarcation of infected lung tissue, which coincided with the clearance of P. multocida from the spleen, thus hampering further invasion. Consequently, heterophil activation plays a dual role for the outcome of a P. multocida infection in chickens, where it initially seems to promote invasion and systemic spread but subsequently helps limit the infection by giant cell formation and bacterial clearance.     

What has happened in norway after the ban of avoparcin? Consumption of antimicrobials by poultry

When avoparcin was prohibited for use as feed additive in poultry in Norway on 31 May 1995, an increased incidence of Clostridium perfringens-associated necrotic enteritis (NE) and an increase in the use of antibacterial (AB) drug therapy in meat-type poultry was expected. The consumption of AB drugs for use against NE in poultry in the period 1990-2001 was investigated by use of sales statistics at the drug-wholesaler level. Defined daily dose (DDD) per kg live weight poultry was the unit of measurement for drug use (to correct for differences in the dosages). Sales figures of the AB drugs were converted to number of DDDpoultry sold for the numbers of broilers at risk (broilers were 97% of the slaughter poultry). Estimated annual percentages of the broilers treated against NE increased abruptly after the avoparcin ban--but in 1996, this figure declined to the same level as before the ban and has remained at that low level since then. In November 1995, narasin was approved temporarily as an ionophore feed additive (IFA) in broilers. The usage patterns of IFAs in broilers were measured as the weight of feed to which an IFA was added per broiler chicken produced. In 1996-2001, the IFAs used in broilers were predominantly narasin. We note that the temporary increase in NE after the avoparcin ban coincide with the period before narasin became available. The increase in the consumption of AB drugs for the treatment of NE in poultry following the avoparcin ban has been negligible.     

Phylogenetic relationship of equine Actinobacillus species and distribution of RTX toxin genes among clusters

Equine Actinobacillus species were analysed phylogenetically by 16S rRNA gene (rrs) sequencing focusing on the species Actinobacillus equuli, which has recently been subdivided into the non-haemolytic A. equuli subsp. equuli and the haemolytic A. equuli subsp. haemolyticus. In parallel we determined the profile for RTX toxin genes of the sample of strains by PCR testing for the presence of the A. equuli haemolysin gene aqx, and the toxin genes apxI, apxII, apxIII and apxIV, which are known in porcine pathogens such as Actinobacillus pleuropneumoniae and Actinobacillus suis. The rrs-based phylogenetic analysis revealed two distinct subclusters containing both A. equuli subsp. equuli and A. equuli subsp. haemolyticus distributed through both subclusters with no correlation to taxonomic classification. Within one of the rrs-based subclusters containing the A. equuli subsp. equuli type strain, clustered as well the porcine Actinobacillus suis strains. This latter is known to be also phenotypically closely related to A. equuli. The toxin gene analysis revealed that all A. equuli subsp. haemolyticus strains from both rrs subclusters specifically contained the aqx gene while the A. suis strains harboured the genes apxI and apxII. The aqx gene was found to be specific for A. equuli subsp. haemolyticus, since A. equuli subsp. equuli contained no aqx nor any of the other RTX genes tested. The specificity of aqx for the haemolytic equine A. equuli and ApxI and ApxII for the porcine A. suis indicates a role of these RTX toxins in host species predilection of the two closely related species of bacterial pathogens and allows PCR based diagnostic differentiation of the two.     

Short‐term effects of dietary soybean meal and lactic acid bacteria on the intestinal morphology and microbiota of Atlantic salmon (Salmo salar)

The aim of this study was to evaluate the role of the intestinal microbiota in soybean meal enteritis. Three groups of Atlantic salmon (Salmo salar) were fed for 35 days with different diets: a control diet (CD) containing 510 g kg^?1 fishmeal, diet 1 (D1) containing 378 g kg^?1 of soybean meal and diet 2 (D2) containing D1 supplemented with two viable lactic acid bacteria (LAB). As expected, the fish fed with D1 showed clear signs of distal intestinal inflammation during the study compared with the fish fed CD. For the fish fed with D2, the addition of LAB diminished the inflammation at day 28, but did not abolish it. Microbiological analysis demonstrated that specific bacterial groups were not correlated with the development of enteritis, but were correlated with the three diets. Microbacterium, Pseudomonas, Lactococcus lactis sp. cremoris and Aeromonas VIa were correlated with the CD, Aeromonas VIb and Sporosarcina aquimarina were correlated with D1, and Alcaligenes, Acinetobacter, L. lactis sp. lactis and Carnobacterium maltaromaticum were correlated with D2. Shewanella was not affected by the diet and was present in all fish intestines. Our study suggests that LAB may modulate intestinal inflammation; however, the role of the microbiota in the aetiology of enteritis in fish still requires further study.     

Comparison of diet composition,feeding, growth and health of lumpfish (Cyclopterus lumpus L.) fed either feed blocks or pelleted commercial feed

Two duplicate groups of individually tagged lumpfish (mean initial weight: 21.5 ± 3.2 g) were fed either a commercially available lumpfish feed or feed blocks for a period of 123 days. The aim was to evaluate and compare the effects of these feed types on growth, cataract development and histopathology in lumpfish. There were significant differences in growth rates between the groups with fish fed pelleted feed having the highest growth rates. The development of cataracts was significantly different with fish fed pelleted feed having a cataract prevalence of 87% at the end of the study period whilst fish fed with feed blocks had 10% prevalence. The results of the histological examination undertaken in this study showed overall small differences between the two dietary treatments. In some individuals in groups receiving both diets, there was mild to moderate expansion of the lamina propria with tissue most likely to represent fibrous tissue with scattered leucocytes. Overall, the findings of the present study show that lumpfish will readily graze from feed blocks and although growth is lower the prevalence of cataract is greatly reduced using feed blocks.     

Anaesthesia of Atlantic cod (Gadus morhua) — Effect of pre-anaesthetic sedation, and importance of body weight, temperature and stress

The efficacy of the anaesthetic agents benzocaine, metacaine (MS-222), metomidate and 2-phenoxyethanol was studied in Atlantic cod (Gadus morhua) with average body weights of 10 ± 4 g, 99 ± 33 g and 1022 ± 274 g at water temperatures of 8 °C and 16 °C. The agents were tested individually and as combination anaesthesia comprising pre-anaesthetic sedation with a low dosage of metomidate or 2-phenoxyethanol followed by anaesthesia with benzocaine or MS-222. All agents were administered through bath immersion with an exposure time of 5 min. The different treatments resulted in average induction and recovery times ranging from 52 ± 6 s to 182 ± 16 s and 77 ± 26 s to 659 ± 46 s respectively. Induction and recovery times varied in relation to water temperature and were generally shorter at 16 °C for all weight groups and treatments compared to 8 °C. For benzocaine and MS-222 induction and recovery times were found to increase with increasing body weight. For metomidate the recovery time increased with increasing weight whereas there were no weight related differences in induction time. No differences in either induction or recovery times associated to body weight were found for 2-phenoxyethanol. Acute stress prior to anaesthesia with MS-222 resulted in significantly shorter induction time and prolonged recovery time, as well as deeper anaesthetised fish. The dosage of MS-222 had to be reduced in order to avoid mortality in fish subjected to acute stress. Combination anaesthesia allowed a reduction of the dosages used for inducing anaesthesia and produced markedly reduced recovery times compared to agents administered individually.