Diagnosis of flavobacteriosis by direct amplification of rRNA genes

A broad-range bacterial PCR method with universal 16S rDNA targeting primers and bacterial cultivation was used to identify the putative pathogen in flavobacterial outbreaks. Restriction fragment length polymorphism (PCR-RFLP) analysis and sequencing of the partial 16S rDNA PCR products of 10 skin samples and 10 representative isolates derived from the same fish specimens revealed differences between direct molecular and cultivation-based analysis. Flavobacterium columnare-like sequences dominated in the direct molecular analysis in most cases, whereas most of the isolates belonged to a phylogenetically heterogeneous group of flavobacteria clustering with F. hibernum. F. columnare was isolated in only 1 outbreak. The possible explanations for the different results may be attributable to difficulties in the plate cultivation procedure of external flavobacterial samples. During plate cultivation, the dominating Flavobacterium species can be masked by saprophytic species of the same genus or other genera, or the growth of flavobacteria can be completely inhibited by antagonistic bacteria such as Pseudomonas. Direct analysis of the prevailing 16S rDNA sequences avoids the problems with cultivation and may thus be preferable for the diagnosis of flavobacterial diseases. When isolating flavobacteria from external samples, serial dilution of the sample before plating can improve the results.     

The breeding biology of the starling Sturnus vulgaris in northern Finland

The breeding biology of the starling Sturnus vulgaris was studied in three populations in northern Finland, with additional reference localities in nearby areas. Results from a total of 329 nests are presented from years 1962-1976.
The onset of laying in the Oulu area took place on 5 May, the median date being 10 May, about one week later than in southern Finland and 2–3 weeks later than in central Europe. The clutch-size was 5.29 ± 0.05 in the first nests and 5.06 ± 0.26 in later ones. Incubation time was 12.1 ± 0.6 d. An average of 3.31 ± 0.10 fledglings was produced per pair, 3.69 ± 0.08 in succesful clutches, which is significantly less than usually reported from central Europe. Most of the losses were due to starvation of the young.
No second broods were observed in the Oulu area, and repeated nesting was not common, probably because of the general late start of laying.
The reasons for the recent decline in several Finnish starling populations do not lie in the production capacity but must be sought for elsewhere.     

Environmental Variation Generates Environmental Opportunist Pathogen Outbreaks

Many socio-economically important pathogens persist and grow in the outside host environment and opportunistically invade host individuals. The environmental growth and opportunistic nature of these pathogens has received only little attention in epidemiology. Environmental reservoirs are, however, an important source of novel diseases. Thus, attempts to control these diseases require different approaches than in traditional epidemiology focusing on obligatory parasites. Conditions in the outside-host environment are prone to fluctuate over time. This variation is a potentially important driver of epidemiological dynamics and affect the evolution of novel diseases. Using a modelling approach combining the traditional SIRS models to environmental opportunist pathogens and environmental variability, we show that epidemiological dynamics of opportunist diseases are profoundly driven by the quality of environmental variability, such as the long-term predictability and magnitude of fluctuations. When comparing periodic and stochastic environmental factors, for a given variance, stochastic variation is more likely to cause outbreaks than periodic variation. This is due to the extreme values being further away from the mean. Moreover, the effects of variability depend on the underlying biology of the epidemiological system, and which part of the system is being affected. Variation in host susceptibility leads to more severe pathogen outbreaks than variation in pathogen growth rate in the environment. Positive correlation in variation on both targets can cancel the effect of variation altogether. Moreover, the severity of outbreaks is significantly reduced by increase in the duration of immunity. Uncovering these issues helps in understanding and controlling diseases caused by environmental pathogens.     

Population screening for coeliac disease in primary care by district nurses using a rapid antibody test: diagnostic accuracy and feasibility study

Objective To evaluate the feasibility and diagnostic accuracy of screening for coeliac disease by rapid detection of IgA antibodies to tissue transglutaminase performed in primary care.Design District nurses screened 6 year old children using rapid antibody testing of finger prick blood. They also collected capillary blood samples for laboratory determination of IgA and IgG antibodies to endomysium and IgA antibodies to tissue transglutaminase. Children with positive rapid test results were directly sent for biopsy of the small intestine.Setting Primary care in Jász-Nagykun-Szolnok county, Hungary.Participants 2690 children (77% of 6 year olds living in the county) and 120 nurses.Main outcome measures Positivity for antibodies to endomysium or transglutaminase in the laboratory and coeliac disease confirmed at biopsy.Results 37 children (1.4%, 95% confidence interval 0.9% to 1.8%) had biopsy confirmed coeliac disease. Only five of these children had been diagnosed clinically before screening. Rapid testing had a 78.1% sensitivity (70.0% to 89.3%) and 100% specificity (88.4% to 100%) for a final diagnosis of coeliac disease by biopsy. Sensitivity was 65.1% (50.2% to 77.6%) and specificity was 100% (99.8% to 100%) compared with combined results of IgA and IgG laboratory tests. Trained laboratory workers detected 30 of the 31 newly diagnosed IgA competent patients with the rapid test kit used blindly. Median time to biopsy after a positive rapid test result was significantly shorter (20 days, range 4-148) than after a positive laboratory result (142 days, 70-256; P<0.001). Children with coeliac disease detected at screening were smaller and had worse health status than their peers but they improved on a gluten-free diet.Conclusions A simple rapid antibody test enabled primary care nurses to detect patients with coeliac disease in the community who were not picked up in clinical care. Extra training is needed to improve sensitivity.     

Seasonal variation in endogenous serum melatonin profiles in goats: a difference between spring and fall?

The pineal hormone melatonin serves as a signal of day length in the regulation of annual rhythms of physiological functions and behavior. The duration of high melatonin levels in body fluids is proportional to the duration of the dark period of the day. Due to the direct suppression of melatonin by light, the overt melatonin rhythm may differ from the endogenous rhythm driven by the hypothalamic circadian clock. The aim of this study was to find out possible differences between the overt and endogenous melatonin rhythms in goats during the course of a year. Seven Finnish landrace goats (nonlactating females) were kept under artificial lighting that approximately simulated the annual changes of day length at 60 degrees N. Blood samples for melatonin measurements by radioimmunoassay were collected at 2-h intervals during six seasons: winter (light:dark 6:18 h), early spring (10:14), late spring (14:10), summer (18:6), early fall (14:10), and late fall (10:14). Melatonin profiles were determined for 2 consecutive days, first in light-dark (LD) conditions and then in continuous darkness (DD). In LD conditions, the profiles matched the dark period with one exception: In winter, the mean peak duration was significantly shorter than the scotoperiod. In DD conditions, two types of endogenous melatonin patterns were found: a "winter pattern" (peak duration 13-15 h) in winter, early spring, early fall, and late fall, and a "summer pattern" (duration about 11 h) in late spring and summer. Thus, in equal habitual LD conditions in late spring and early fall (LD 14:10), the endogenous melatonin rhythms were not quite similar: The pattern in late spring resembled that in summer, and the pattern in early fall that in winter. These results suggest that, in addition to the light-adjusted overt melatonin rhythm, the endogenous rhythm of melatonin secretion varies during the course of a year.