Milk production and efficiency of utilization of nitrogen, metabolizable protein, and amino acids are affected by protein and energy supplies in dairy cows fed alfalfa-based diets.

Alfalfa has a lower fiber digestibility and a greater concentration of degradable protein than grasses. Dairy cows could benefit from an increased digestibility of alfalfa fibers, or from a better match between nitrogen and energy supplies in the rumen. Alfalfa cultivars with improved fiber digestibility represent an opportunity to increase milk production, but no independent studies have tested these cultivars under the agroclimatic conditions of Canada. Moreover, decreasing metabolizable protein (MP) supply could increase N use efficiency while decreasing environmental impact, but it is often associated with a decrease in milk protein yield, possibly caused by a reduced supply of essential AA. This study evaluated the performance of dairy cows fed diets based on a regular or a reduced-lignin alfalfa cultivar and measured the effect of energy levels at low MP supply when digestible His (dHis), Lys (dLys), and Met (dMet) requirements were met. Eight Holstein cows were used in a double 4 × 4 Latin square design, each square representing an alfalfa cultivar. Within each square, 4 diets were tested: the control diet was formulated for an adequate supply of MP and energy (AMP_AE), whereas the 3 other diets were formulated to be deficient in MP (DMP; formulated to meet 90% of the MP requirement) with deficient (94% of requirement: DMP_DE), adequate (99% of requirement: DMP_AE), or excess energy supply (104% of requirement; DMP_EE). Alfalfa cultivars had no significant effect on all measured parameters. As compared with cows receiving AMP_AE, the dry matter intake of cows fed DMP_AE and DMP_EE was not significantly different but decreased for cows fed DMP_DE. The AMP_AE diet provided 103% of MP and 108% of NEL requirements whereas DMP_DE, DMP_AE, and DMP_EE diets provided 84, 87, and 87% of MP and 94, 101, and 107% of NEL requirements, respectively. In contrast to design, feeding DMP_EE resulted in a similar energy supply compared with AMP_AE, although MP supply has been effectively reduced. This resulted in a maintained milk and milk component yields and improved the efficiency of utilization of N, MP, and essential AA. The DMP diets decreased total N excretion, whereas DMP_AE and DMP_EE diets also decreased milk urea-N concentration. Reducing MP supply without negative effects on dairy cow performance is possible when energy, dHis, dLys, and dMet requirements are met. This could reduce N excretion and decrease the environmental impact of milk production.

Phaeohyphomycotic cyst of the skin caused by Exophiala jeanselmei.

A dermosubcutaneous nodule presenting with a superficial papular vascular component occurred in a man receiving long-term prednisone therapy. The histologic findings were characteristic of a phaeohyphomycotic cyst, and a black mold, Exophiala jeanselmei, was isolated. Despite treatment with ketoconazole and local heat, the lesion persisted and was excised. The fungus could be seen in the excised tissue, but cultures were sterile. Subcutaneous phaeohyphomycosis is a relatively uncommon, but recently more frequently recognized type of opportunistic fungus infection.

Taxonomic and nomenclatural evaluation of the genera Candida and Torulopsis.

It is concluded that the validly published genera Candida and Torulopsis are taxonomically distinct. The recently proposed merger of these two yeast genera is rejected.

Immunodiffusion and complement fixation assays with sera from mucormycotic-infected mice.

Results using homogenate antigens of Rhizomucor pusillus against immunized rabbit sera, mouse ascites fluid and sera from mucormycotic-infected mice, detected by immunodiffusion and complement fixation assays are presented. Using immunodiffusion techniques, common antigens and unique antigens from Rh. pusillus, Rhizopus oryzae and Absidia corymbifera were observed. Complement fixation titers of greater than 256 and 128 were obtained in immunized rabbit sera and mouse ascites fluid, respectively. However, no appreciable titers of antibody were measured from mucormycotic-infected animals by either immunodiffusion or complement fixation.

Passive immunization in murine mucormycosis.

Antibody raised in mice against mycelial homogenates of Rhizomucor pusillus was effective in passive immunization against pulmonary and disseminated mucormycosis (phycomycosis) in immunocompromised mice. Mice intranasally inoculated and infected with Rh. pusillus and treated with antisera had a statistically significant increased resistance to infection and a diminished secondary dissemination of viable fungal fragments. Histological examination of infected lung tissues showed that antibody treated animals were apparently able to degrade hyphal fragments.

Murine model of pulmonary mucormycosis in cortisone-treated mice.

Intranasal inoculation of Rhizomucor pusillus sporangiospores into cortisone-treated mice produced pulmonary and disseminated mucormycosis (phycomycosis). Evidence for infection in cortisone treated mice was obtained by recovery of Rh. pusillus from homogenates of tissue. Confirmation of infection was shown histologically. The 50% infectious dose was 2.4 x 10(2) colony forming units for lung infections and 2.7 x 10(5) colony forming units for brain infections. No evidence of sporangiospore germination was found in tissues of non-cortisone-treated mice although sporangiospores were found throughout pulmonary tissues. In infected tissues of cortisone-treated mice, hyphae were covered with leukocytes and tissue necrosis was extensive.

Pathogen factors and host factors in murine pulmonary blastomycosis.

Factors related to pathogenesis were studied in a murine model of pulmonary fungal infection with strains of Blastomyces dermatitidis. Strain 26199V was greater than or equal to 10(5)-fold more lethal in pulmonary challenge than strain GA-1. This relationship between the two strains also occurred after intraperitoneal challenge. Serial studies with lung cultures and histology of sacrificed animals after pulmonary challenge with similar doses, and challenge studies in mice of differing maturity, indicated GA-1 is impaired in initial replication in situ, although the two strains grow equally well in the presence of murine substrates in vitro. In vitro studies indicated the two strains were indistinguishable in most studies of biochemical and metabolic markers, and in studies with chemical and physical inhibitors. The exceptions were their morphologic appearance in the yeast phase, ability to hydrolyze esculin, and susceptibility to crystal violet dye and bile. The last finding and previous work suggested possible differences in lipid content; these were confirmed in studies which also included two other strains. Greater phospholipid and palmitic acid content were associated with greater virulence.

Spontaneous mutant of Blastomyces dermatitidis attenuated in virulence for mice.

A spontaneous mutation occurred in cultures of a virulent strain of Blastomyces dermatitidis during serial passage at 35-37 degrees C. The mutant strain was shown to be 10,000-fold less virulent for mice than the parent strain, and this was independent of the challenge dose, the age of the challenged host, and the route of challenge (although attenuation was greater for pulmonary than for peritoneal challenge). The mutant grows as well as the parent in fungal media or in the presence of murine substrates. Studies of the chronology of pulmonary infection indicate the mutation affects an early event (first week after challenge) in establishment of infection and interaction with host defenses. Scanning electron microscopy showed that the mutant lacks deep irregular surface ridges and grooves present in the parent. It had increased resistance to crystal violet in vitro, increased susceptibility to bile, and could hydrolyze esculin. The latter findings are of interest because they place the mutant in an intermediate position with respect to these properties between the virulent parent and a previously studied avirulent strain. Lipid analyses indicated a marked increase in fatty acids in the mutant. Studies of four B. dermatitidis strains have also associated increasing palmitic acid and phospholipid content with increasing virulence.

Botryomycosis: first report of human brain involvement.

A 57-year-old man, previously well except for dental caries and a history of Wolff-Parkinson-White syndrome, presented with marching right-sided motor seizures of sudden onset. Cerebral arteriography and scan demonstrated an avascular left frontal lobe mass. At operation, it was identified as an abscess and was totally excised. Histologically, granules resembling those seen in actinomycosis were demonstrated in the abscess wall, but special stains revealed gram-positive cocci in chains within and outside the granules. Fungal spores, mycelia, or branching filamentous structures were absent. Acid-fast stains were negative, and alpha-hemolytic streptococcus was recovered in pure culture from the abscess. While the patient was convalescing with penicillin therapy, a dental survey revealed the presence of periodontal abscesses which were drained by exodontia. Culture of the tooth sockets showed alpha-hemolytic streptococcus and Staphylococcus aureus. The literature on this relatively rare bacterial disease which histologically resembles actinomycosis is reviewed.

Keratitis and endophthalmitis caused by Petriellidium boydii.

A 26-year-old man sustained burns of the left eye and eyelids from molten aluminum. Antimicrobial and anti-inflammatory therapy was instituted. Cultures of conjunctival material collected 14 days after the burn grew abundant colonies of Petriellidium boydii. Because of severe pain and impending corneal perforation, the eye was enucleated.

Acremonium falciforme as a cause of mycetoma in California.

Three cases of mycetoma were studied in the San Francisco Bay area of northern California during the period from 1960 to 1973. In each case the causal agent was identified on the basis of the histological structure of the granules and by isolation of the etiological agent in pure culture. The fungus in all cases was found to be Acremonium falciforme. This is the first report of A. falciforme occurring as a disease agent in the United States.

Mycotic flora of the interdigital spaces of the human foot: a preliminary investigation.

A qualitative and quantitative study of the mycotic flora of the interdigital spaces of 27 male volunteers yielded 1,291 moulds and 598 yeasts. Concurrently, a study of garden soil was conducted in order to obtain data concerning the transient-resident status of the fungi recovered from the feet. Of the 120 genera and species of fungi isolated, 51 were recovered from the volunteers, 53 from the soil, and 16 from both categories. The most commonly recovered fungi from the toewebs, in order to occurrence, were Torulopsis candida, Mycelia Sterilia, T. maris, Rhodotorula rubra, Cryptococcus albidus, and species of Aspergillus and Penicillium. Without sign of infection, Cryptococcus neoformans was isolated from 5 volunteers. Candida albicans was not recovered from any subject. Trichophyton mentagraphytes was recovered from 7 volunteers and T. rubrum from one.

Cryptococcus neoformans in pigeon feces in San Francisco.

Typical Cryptococcus neoformans was isolated from one of 10 specimens of pigeon feces collected in downtown San Francisco. This isolation from a small sample suggests considerable prevalence of this important pathogen and tends to confirm that it is ubiquitous.