Human fibronectin was immobilized on glass beads. The beads were used to evaluate binding of Lactobacills reuteri to fibronectin. Organisms bound to the glass beads were detected using fluorescence microscopy after treatment with acridine orange. This binding was confirmed and quantified with the use of [H-3]-labelled organisms. Three strains of Lactobacillus reuteri, three strains of Lactobacillus acidophilus and one strain of Lactobacillus fermentum were tested for binding capacity. L. reuteri strain 1063 exhibited a strong binding to the immobilized fibronectin, and L. acidophilus 1754 showed a slight binding. The binding of L. reuteri to the fibronectin was mediated by a protein as judged by the absence of binding after treatment of the bacteria with proteolytic enzymes. Treatment of the bacteria with urea, SDS and heat (80-degrees-C) also reduced binding. Treatment of the bacterial cells prior to the assay with fibronectin interfered with binding. Albumin did not show this interaction.

A feather-degrading culture was enriched with isolates from a poultry waste digestor and adapted to grow with feathers as its primary source of carbon, sulfur, and energy. Subsequently, a feather-hydrolytic, endospore-forming, motile, rod-shaped bacterium was isolated from the feather-degrading culture. The organism was Gram stain variable and catalase positive and demonstrated facultative growth at thermophilic temperatures. The optimum rate of growth in nutrient broth occurred at 45 to 50°C and at pH 7.5. Electron microscopy of the isolate showed internal crystals. The microorganism was identified as Bacillus licheniformis PWD-1. Growth on hammer-milled-feather medium of various substrate concentrations was determined by plate colony count. Maximum growth (approximately 10 9 cells per ml) at 50°C occurred 5 days postinoculation on 1% feather substrate. Feather hydrolysis was evidenced as free amino acids produced in the medium. The most efficient conditions for feather fermentation occurred during the incubation of 1 part feathers to 2 parts B. licheniformis PWD-1 culture (10 7 cells per ml) for 6 days at 50°C. These data indicate a potential biotechnique for degradation and utilization of feather keratin.

Athymic nude mice used as sentinel animals in a mouse holding room died of pneumonia 17 to 32 weeks after being placed in the room. Lesions in the pulmonary parenchyma consisted of monocytic exudate, epithelial cell necrosis, hemorrhage, fibrin deposition and interstitial fibrosis. Septal edema, septal cell necrosis and septal capillary stasis were common, but there was limited sloughing of bronchial lining epithelium. Indirect fluorescence microscopy (IFA) of lung sections using pneumonia virus of mice (PVM) antibody was positive. The pneumonia and IFA results were reproduced in euthymic mice inoculated experimentally with lung suspension from naturally infected mice or with tissue culture fluid from cultures infected with American Type Culture Collection PVM. The lungs of a naturally infected nude mouse were studied by transmission electron microscopy. Virus growth was found on Type II alveolar epithelium and on poorly differentiated replacement alveolar epithelium. Virus particles appeared as long exophytic filaments containing one to six linearly arranged nucleocapsids. Inclusion bodies and intracellular virus structures were not observed.

The biological activity of an anti-Sindbis monoclonal antibody (MCAB 49) has been explored. The antibody recognizes an epitope on the E2 glycoprotein of Sindbis virus and, in the presence of complement (C'), neutralizes virus infectivity. In the absence of C', reaction of the antibody with our laboratory strain of Sindbis, SB, increased the number of plaque-forming units (PFU) detected on baby hamster kidney (BHK) cells rather than neutralizing virus infectivity. The elevated titers of SB approached, but never exceeded, the number of virions calculated from the particle:PFU ratio, indicating that the additional PFU might have resulted from activation of normally noninfectious particles. The apparent activation could not be attributed to disaggregation of SB by MCAB 49 as shown by ultraviolet inactivation experiments with antibody-treated and untreated virus preparations. Fc receptors did not appear to be involved in the antibody-mediated activation. Fab' and F(ab')2 fragments of MCAB 49 also increased the number of observed PFU of SB. Control monoclonal antibodies of the same isotype, but specific for the tobacco etch virus capsid protein, were unable to compete for cellular binding sites with the SB/MCAB 49 complex. Rather, the SB/MCAB 49 complex appeared to utilize the same receptor(s) as SB in that SB and the SB/MCAB 49 complexes competed with each other for binding sites on BHK cells. Binding studies with 32P-labeled SB showed that a higher proportion of MCAB 49 activated virions than untreated virions associated with BHK cells. Moreover, activated virions were much less susceptible to elution. These results suggest that reaction which MCAB 49 may facilitate successful attachment of SB to its receptor, or receptors, on BHK cells.

The SEQALIGN programs1 described in this report aid in the assembly of up to 100 individual overlapping DNA sequences generated by M-13 subcloning and sequencing methods. The program produces a printout of the aligned sequences presented in register. Use of the program will be facilitated because 1) it is written with the Microsoft BASIC interpreter, 2) sequence data may be entered and edited using WORDSTAR or similar word processing programs, and 3) hardware requirements for execution of the program on CP/M or MS-DOS (IBM-PC compatible) systems are minimal.