The rate and nocturnal rhythm of mosquito attacks of birds and human beings were studied in the open biotopes of Volgograd and its vicinity in 2004. Thirteen and 11 species of the subfamily Culicinae were collected under the Berezantsev bell and from the traps containing a chicken (a hen), respectively; of them 9 species were common. The mosquitoes of an Anopheles maculipennis complex were caught in a small portion to the traps of both types. Most species of Aedes were highly anthropophilic, showed the minimum activity at night and their abundance considerably decreased by the early transmission period. Among the species that were active during the transmission period, Ae. vexans, Coq. richiardii, and Cx. modestus more intensively attacked a human being than birds and Cx. pipiens was frequently attracted into the hen traps. The attraction of each species of the caught varied during the transmission period. The maximum attacks of Cx. modestus and Cx. pipiens on man and birds coincide and those of Coq. Richiardii and Cx. pipiens on man was observed earlier than on birds. A possible role of mosquitoes of different species in the epizootic and epidemiological processes is discussed.
It is established that the activity of asparaginase in the chicken pectoral muscle tumours is considerably higher than of that in normal muscle. Dynamics of the asparaginase activity in blood is parallel to the changes in the enzymatic activity in the tumour under experimental sarcomatosis. The higher asparaginase activity is also observed in the vicera except for the liver in the terminal period of sarcomatosis development. The glutaminase activity is found to be more stable.
House dust is an important source of different toxic metabolites as well as allergens, including those of fungal origin, in the indoor environment. A bio-assay employing 1-day-old chick tracheas was used to characterize airway effects of 2-butanone and dimethylsulphoxide (Me2SO) extracts of 23 dust samples collected from water damaged (13) and control (10) Danish schools. Direct microscopical analysis of samples, followed by cultivation on dichloran 18 % glycerol agar at 25 degrees C for 10 days to establish their mycoflora, was performed. The in vitro ciliostatic potential of the chloroform-extractable endo- and exometabolites of 41 representative fungal isolates was determined. Nine dust extracts in 2-butanone (2 from damp rooms) or 10 (6) in Me(2)SO showed some ciliostatic activity in the 3-days' experiment. Fungal composition of dust from buildings with leakage was almost identical with that from undamaged houses, as well as the fungal colony counts from the damp schools and the control samples. Aspergillus spp. were prevalent in the samples - 31 or 40 % of all fungi, followed by Penicillium spp. and Cladosporium cladosporioides. Alternaria spp., Chaetomium spp., Mucor spp., Mycelia sterilia, Paecilomyces variotii, Rhizopus sp., Ulocladium sp. and yeasts were each isolated in less than 8 % of the fungal content. No Aspergillus flavus isolate (8 in total) was aflatoxigenic,em>in vitro. Alternaria spp., Aspergillus spp., Botrytis cinerea, Penicillium spp., C. cladosporioides, Chaetomium spp. and Ulocladium sp.; in total, 88 % of all fungi tested, produced ciliostatically active metabolites. These toxigenic strains were also present in 4 dust samples from controls and 5 dust samples from water damaged buildings. Extracts of these dust samples were also toxic in bioassay. There were bio-detectable concentrations (10-20 microg of extracts/ml of the organ culture medium) of toxic compounds in house dust. Contribution of fungal metabolites to its toxic effect should be studied further.
The aim of this study was to analyse the genetic diversity among Clostridium perfringens isolates from Danish broiler chickens since both sick and presumably healthy animals were investigated. Isolates (n=279) collected from chickens from 25 farms were analysed by pulsed-field gel electrophoresis (PFGE) with the restriction enzyme SmaI. A high genetic diversity was found. Isolates with different PFGE types were toxin typed by PCR and all were found to be of type A. The results showed that healthy broiler chickens carried several different C. perfringens clones both within a flock and even within individual birds, whereas flocks suffering from necrotic enteritis (NE) or cholangio-hepatitis carried only one or two clones.
Campylobacteriosis is the most frequently reported zoonosis in the EU and the epidemiology of sporadic campylobacteriosis, especially the routes of transmission, is to a great extent unclear. Poultry easily become colonised with Campylobacter spp., being symptom-less intestinal carriers. Earlier it was estimated that internationally between 50% and 80% of the cases could be attributed to chicken as a reservoir. In a Norwegian surveillance programme all broiler flocks under 50 days of age were tested for Campylobacter spp. The aim of the current study was to identify simultaneous local space-time clusters each year from 2002 to 2007 for human cases of campylobacteriosis and for broiler flocks testing positive for Campylobacter spp. using a multivariate spatial scan statistic method. A cluster occurring simultaneously in humans and broilers could indicate the presence of common factors associated with the dissemination of Campylobacter spp. for both humans and broilers.
Local space-time clusters of humans and broilers positive for Campylobacter spp. occurring simultaneously were identified in all investigated years. All clusters but one were identified from May to August. Some municipalities were included in clusters all years.
The simultaneous occurrence of clusters of humans and broilers positive for Campylobacter spp. combined with the knowledge that poultry meat has a nation-wide distribution indicates that campylobacteriosis cases might also be caused by other risk factors than consumption and handling of poultry meat.Broiler farms that are positive could contaminate the environment with further spread to new broiler farms or to humans living in the area and local environmental factors, such as climate, might influence the spread of Campylobacter spp. in an area. Further studies to clarify the role of such factors are needed.
Cites: Appl Environ Microbiol. 2004 Dec;70(12):7474-8015574950
The causes of the simultaneous rise of salmonellosis morbidity induced by S. enteritidis among the population of three towns in the Perm region were studied. The study revealed the leading role of eggs and chicken meat as factors contributing to the transfer of this infection to the population of different territories, commonly supplied with the products of one poultry plant. The contamination of eggs and chickens with S. enteritidis occurred at the plant due to Salmonella infection of chickens, parallel with the use of nonbalanced mixed fodder, originally intended for feeding swine. Analysis of the epidemic and epizootic processes of Salmonella infection in this epidemic situation made it possible to reliably establish the factors contributing to the transfer of the infective agent and the site of contamination.
[An assessment of the connection between the annual population morbidity of salmonellosis due to Salmonella enteritidis and the dynamics of the epizootic process among chickens in commercial poultry plants].
The dynamics of annual morbidity in salmonellosis caused by S. enteritidis among the population of Perm during the period of 1987-1992 was analyzed. Blood sera taken from 4,689 practically healthy donors and from 6,997 hens at poultry breeding complexes were studied in the passive hemagglutination test with the use of complex Salmonella diagnosticum. The study revealed that seasonal rises in morbidity caused by S. enteritidis in winter and spring months, as well as in autumn months, were linked with the activation of the epizootic process of Salmonella infection among hens at poultry-breeding complexes during these periods of the year. A rise in the level of anti-Salmonella antibodies in poultry and human blood sera was found to be the precursor of the aggravation of the epidemic situation.
The Norwegian Action Plan against Campylobacter in broilers was implemented in May 2001 with the objective of reducing human exposure to Campylobacter through Norwegian broilers. From each flock, samples collected at the farm about one week prior to slaughter, and then again at the slaughter plant, are examined for the presence of Campylobacter. All farmers with positive flocks are followed up with bio-security advice. Sampling of broiler products at retail level is also included in the Action Plan. The aim of this study was to evaluate the existing sampling and culturing methods of the Norwegian Action Plan against Campylobacter in broilers. The material collected was pooled faecal samples, pooled cloacae samples and caecae samples from individuals. The highest number of positives, from culturing of the pooled faecal samples, the pooled cloacae swabs and the caecae swabs from individuals, were obtained at incubation temperature 41.5 degrees C. When comparing the results at incubation temperature 37 and 41.5 degrees C, the faecal samples from the farms demonstrated a high concordance, with a kappa value of 0.88. The results from culturing cloacae swabs and caecae samples from slaughter plant level at two temperatures did not agree very well with a kappa value of 0.21 and moderate value of 0.57, respectively, but were both disconcordant at a level of 0.05. Modelling farm level data indicated that if increasing the number of pooled samples per flock from two (in existing regime) to three, the flock sensitivity increases from 89% to 95%. Modelling of slaughter plant data indicated that three pooled cloacae swabs are needed to identify 90% of the positive flocks. The results from the modelling of caecae data indicated that samples from seven individuals are sufficient to identify 90% of the positive flocks and caecae samples could thus be an alternative to cloacae sampling at slaughter plant level.
We developed an oral sensitization protocol for food proteins for the rat. Young Brown Norway (BN) rats were exposed to 1 mg ovalbumin (OVA) by daily gavage dosing for 42 days without the use of an adjuvant. OVA-specific IgE and IgG responses were determined by ELISA. On an oral challenge with OVA some clinical symptoms of food allergy-like effects on the respiratory system, blood pressure, and permeability of the gastrointestinal barrier were studied. In addition, BN rats were orally exposed to a total hen egg white protein (HEW) extract and cow's milk (CM) and the specificities of induced antibody responses were compared with the specificities of antibodies in sera from egg- and milk-allergic patients using immunoblotting. Animals orally exposed to the allergens developed specific IgE and IgG antibodies which recognized the same proteins compared with antibodies from egg- or CM-allergic patients. Among the various clinical symptoms of food allergy, gut permeability was increased after an oral challenge. In addition, some animals demonstrated a temporary decrease in breathing frequency or systolic blood pressure. The results obtained show that the Brown Norway rat is a suitable animal model for inducing specific IgG and IgE responses on daily intragastric dosing of OVA without the use of an adjuvant. Moreover, local immune-mediated effects on oral challenge are observed. The observation that enterally exposed BN rats and food-allergic patients demonstrate antibody responses to a comparable selection of proteins on exposure to different protein mixtures (HEW and CM) further supports the suitability of the BN rat as an animal model for food allergy research and for the study of the allergenicity of (novel) food proteins.
In May/June 2005 an outbreak of diarrhoeal illness occurred among company employees in Copenhagen. Cases were reported from seven of eight companies that received food from the same catering kitchen. Stool specimens from three patients from two companies were positive for Campylobacter jejuni. We performed a retrospective cohort study among employees exposed to canteen food in the three largest companies to identify the source of the outbreak and to prevent further spread. Using self-administered questionnaires we collected information on disease, days of canteen food eaten and food items consumed. The catering kitchen was inspected and food samples were taken. Questionnaires were returned by 295/348 (85%) employees. Of 247 employees who ate canteen food, 79 were cases, and the attack rate (AR) was 32%. Consuming canteen food on 25 May was associated with illness (AR 75/204, RR=3.2, 95%CI 1.3-8.2). Consumption of chicken salad on this day, but not other types of food, was associated with illness (AR=43/97, RR=2.3, 95%CI 1.3-4.1). Interviews with kitchen staff indicated the likelihood of cross-contamination from raw chicken to the chicken salad during storage. This is the first recognised major Campylobacter outbreak associated with contaminated chicken documented in Denmark. It is plausible that food handling practices contributed to transmission, and awareness of safe food handling and storage has since been raised among kitchen staff. The low number of positive specimens accrued in this outbreak suggests a general underascertainment of adult cases in the laboratory reporting system by a factor of 20.
Erratum In: Euro Surveill. 2006 May;11(5):1 p following 139