highway stormwater runoff quality: development of surrogate parameter relationships

The development of relationships for predicting the impact of highway stormwater runoff is described. The predictive relationships are regression-based equations reflecting variations in the magnitude of the constituents of interest. The objective is to identify a subset of constituents that can be used as surrogates for the remaining constituents as a means of decreasing the costs of collection and measurement of highway stormwater runoff quality data. The Minnesota highway stormwater quality database complied in the late 1970's and early 1980's is employed in identifying the set of surrogate parameters. The findings indicate that total suspended solids, total dissolved solids, total volatile solids, and total organic carbon are effective surrogate parameters for numerous metals, ionic species, and nutrients. The findings also indicated that the developed ionic species constituent relationships are portable, while the metal and nutrient constituent relationships were limited to urban sites with similar environmental conditions. The development of these relationships represents a step towards remediating and preventing the problem of nonpoint source highway pollution.     

Detection of Pasteurella multocida in pigs with porcine dermatitis and nephropathy syndrome.

Comprehensive bacterial cultures were made on samples from 20 pigs that had died of porcine dermatitis and nephropathy syndrome after a short clinical illness. Eleven species of porcine bacterial pathogens and a range of commensal organisms were isolated. Pasteurella multocida was isolated from 16 of the 20 cases but the other pathogens occurred much less commonly. P. multocida was isolated from between one and five sites per case and from the tonsils, retropharyngeal lymph node or lungs in 14 of the 16 cases. Immunohistochemical investigations of kidneys from 30 cases of the syndrome (including the 20 cases in the bacteriological study) revealed P. multocida-specific staining in 26 of the cases, primarily in the renal tubular epithelial cells of the proximal convoluted tubules, but also in the glomeruli, in lesions of renal vasculitis and in the cytoplasm of interstitial mononuclear cells.     

Foot-and-mouth disease and the African buffalo (Syncerus caffer). 1. Carriers as a source of infection for cattle

Ten pregnant buffalo cows, six of which were subsequently shown to be carriers of SAT 1, 2 and 3 viruses, were captured in the Kruger National Park (KNP) and allowed to calve in captivity. The buffalo cows and calves were separated by a fence from 6 FMD susceptible cattle but the buffalo and cattle were obliged to use common drinking troughs and hay racks. Over a period of 15 months, during which the buffalo calves lost their maternally-derived immunity, neither the buffalo calves nor the susceptible cattle became infected with FMD virus. By the end of the observation period, however, only 1 buffalo cow still had detectable virus in its oesophageal/pharyngeal specimens.     

African swine fever. I. Morphological changes and virus replication in blood platelets of pigs infected with virulent haemadsorbing and non-haemadsorbing isolates

Replicating and mature viral particles were detected with the transmission electron microscope in blood platelets of pigs infected with virulent haemadsorbing and non-haemadsorbing African swine fever virus isolates. Although platelet numbers decreased terminally in infected pigs, the most noticeable morphological damage to these cells apparent in the last 2 days of the disease included cytoplasmic swelling, vacuolation, fragmentation and loss of dense granules.     

Prophylactic effect of monensin sodium against experimentally induced paratuberculosis in mice.

Monensin sodium (0, 15, or 30 mg/kg of complete feed) was fed ad libitum for 1 week to female mice (strain C57BL6/J) that were genetically susceptible to infection with Mycobacterium paratuberculosis. Ten mice in each of the 3 groups were inoculated intraperitoneally with M paratuberculosis (10(9) organisms). Sterile saline solution was injected intraperitoneally into 10 other mice in each group. Rations were continued for 50 days, then mice were euthanatized, and body weight, splenic weight, and hepatic weight for each mouse were recorded. Ratios of body weight to splenic weight and of body weight to hepatic weight were calculated for each mouse. Hepatic granulomas in 50 light microscopic fields were counted, and presence of acid-fast organisms in those granulomas was recorded. Infected mice given monensin had higher body weight and fewer hepatic granulomas than did mice not given monensin. Although hepatic granulomas were fewer in these mice, they contained acid-fast organisms. Effects of 15 mg of monensin and those of 30 mg of monensin/kg of complete feed were not different.     

Cellular inflammatory response in the lungs of calves exposed to bovine viral diarrhea virus, Mycoplasma bovis, and Pasteurella haemolytica

Three, 5, or 7 days after inoculation with bovine viral diarrhea (BVD) virus (n = 12) or Mycoplasma bovis (n = 12), groups of calves were exposed to aerosols of Pasteurella haemolytica and were euthanatized 4 hours later. Histologic lesions in the lungs and the ratios of neutrophils to alveolar macrophages, collected by bronchoalveolar lavage, were compared with those of clinically healthy calves (n = 8) and calves inoculated with BVD virus only (n = 4), M bovis only (n = 4), or P haemolytica only (n = 2). Inoculation with BVD virus or M bovis did not have a significant (P greater than 0.05) effect on the neutrophil/macrophage ratio in the bronchoalveolar lavage. Aerosol exposure to P haemolytica induced a marked and significant (P less than 0.01) change in the neutrophil/macrophage ratio (from less than 1:9 to greater than 9:1). The reversed neutrophil/macrophage ratio in calves exposed to P haemolytica correlated well with the histologic changes in which small bronchi and bronchioles were plugged with purulent exudate. Inoculation with BVD virus did not induce gross or microscopic lesions in the lungs. Inoculation with M bovis resulted in a severe peribronchial lymphoid hyperplasia with mild exudation of neutrophils and macrophages into the cranioventral parts of the lungs.     

The Pulmonary Clearance of Bacteria by Calves and Mice

Using a modified aerosol generator, white mice and calves were exposed to aerosols of viable Staphylococcus aureus and Pasteurella haemolytica and the clearance of the inhaled organisms by the lungs of the experimental animals was measured. Fifty-seven percent of inhaled S. aureus were cleared in two hours by the mouse lungs, 79% were cleared in four hours and 93% were cleared in eight hours. Fifty-six percent of inhaled P. haemolytica were cleared in two hours by the mouse lungs, 76% were cleared in four hours and 93% were cleared in eight hours. Seventy percent of inhaled S. aureus were cleared in two hours by the calf lungs, 90% were cleared in four hours and 95% were cleared in eight hours. Seventy-five percent of inhaled P.haemolytica were cleared in two hours by the calf lungs, 90% were cleared in four hours and 92% were cleared in eight hours.