ABSTRACT
Gram-positive cocci recovered from diseased rainbow trout from a farm in England were characterized by different methods, including pulsed field gel electrophoresis, as virulent Lactococcus garvieae serogroup 2 (pulsotype A1). Groups of rainbow trout were kept at a range of temperatures and injected intraperitoneally (i.p.) with one of the UK isolates, L. garvieae 00021. The 18 degrees C and 16 degrees C groups showed 67% and 28% mortality, respectively, by day 27 post-injection. Fish kept at 14 degrees C or lower were less susceptible (< or =3% mortality). Raising the temperature of all groups to 18 degrees C at day 27 post-injection did not result in recurrence of the disease, even though viable bacteria were recovered from all groups 42 days later. Grayling were highly susceptible, with 65% mortalities when challenged with 200 colony forming unit fish(-1) by i.p. injection and 37% mortalities when exposed to effluent water from tanks containing affected rainbow trout. Other fish species tested, Atlantic salmon, brown trout and seven cyprinid species, were less susceptible. Viable L. garvieae was isolated from the internal organs of all species tested at the end of the trials, suggesting that they may pose a threat as possible carriers to susceptible farmed and wild fish.
Subject(s)
Cyprinidae , Disease Susceptibility/veterinary , Fish Diseases/microbiology , Gram-Positive Bacterial Infections/veterinary , Lactococcus/immunology , Salmonidae , Animals , Colony Count, Microbial/veterinary , Disease Susceptibility/immunology , Disease Susceptibility/microbiology , Electrophoresis, Gel, Pulsed-Field/veterinary , Fish Diseases/immunology , Fish Diseases/transmission , Gram-Positive Bacterial Infections/immunology , Gram-Positive Bacterial Infections/microbiology , Gram-Positive Bacterial Infections/transmission , Lactococcus/pathogenicity , Serotyping/veterinary , Survival Analysis , Temperature , United Kingdom , VirulenceSubject(s)
Attitude to Health , Internal-External Control , Obesity/psychology , Self Concept , Adolescent , Adult , Female , Humans , MaleABSTRACT
This paper reports the results of a sampling program undertaken by NIOSH to determine the particle size distributions in underground coal mines. The program made use of newly developed cascade impactors capable of being operated with personal sampling pumps. Particle size distribution samples were collected at selected areas in 10 continuous mining sections in three states. Results plotted as mass frequency distributions indicate that a bimodal distribution may exist in areas away from the operations of the continuous miner. A primary size mode of about 17 micron and a secondary size mode of about 5 micron were measured consistently throughout the 10 mines studied.
