In this study, a potent fibrinolytic enzyme-producing bacterium was isolated from soybean flour and identified as Bacillus subtilis K42 and assayed in vitro for its thrombolytic potential. The molecular weight of the purified enzyme was 20.5 kDa and purification increased its specific activity 390-fold with a recovery of 14%. Maximal activity was attained at a temperature of 40 degree C (stable up to 65 degree C) and pH of 9.4 (range: 6.5 - 10.5). The enzyme retained up to 80% of its original activity after pre-incubation for a month at 4 degree C with organic solvents such as diethyl ether (DE), toluene (TO), acetonitrile (AN), butanol (BU), ethyl acetate (EA), ethanol (ET), acetone (AC), methanol (ME), isopropanol (IP), diisopropyl fluorophosphate (DFP), tosyl-lysyl- chloromethylketose (TLCK), tosyl-phenylalanyl chloromethylketose (TPCK), phenylmethylsulfonylfluoride (PMSF) and soybean trypsin inhibitor (SBTI). Aprotinin had little effect on this activity. The presence of ethylene diaminetetraacetic acid (EDTA), a metal-chelating agent and two metallo protease inhibitors, 2,2'-bipyridine and o-phenanthroline, repressed the enzymatic activity significantly. This, however, could be restored by adding Co2+ to the medium. The clotting time of human blood serum in the presence of this enzyme reached a relative PTT of 241.7% with a 3.4-fold increase, suggesting that this enzyme could be an effective antithrombotic agent.

The D values of Yersinia enterocolitica strains IP134, IP107, and WA, irradiated at 25�C in Trypticase soy broth, ranged from 9.7 to 11.8 krad. When irradiated in ground beef at 25 and −30�C, the D value of strain IP107 was 19.5 and 38.8 krad, respectively. Cells suspended in Trypticase soy broth were more sensitive to storage at −20�C than those mixed in ground beef. The percentages of inactivation and of injury (inability to form colonies in the presence of 3.0% NaCl) of cells stored in ground beef for 10 days at −20�C were 70 and 23%, respectively. Prior irradiation did not alter the cell's sensitivity to storage at −20�C, nor did storage at −20�C alter the cell's resistance to irradiation at 25�C. Added NaCl concentrations of up to 4.0% in Trypticase soy agar (TSA) (which contains 0.5% NaCl) had little effect on colony formation at 36�C of unirradiated Y. enterocolitica. With added 4.0% NaCl, 79% of the cells formed colonies at 36�C; with 5.0% NaCl added, no colonies were formed. Although 2.5% NaCl added to ground beef did not sensitize Y. enterocolitica cells to irradiation, when added to TSA it reduced the number of apparent radiation survivors. Cells uninjured by irradiation formed colonies on TSA when incubated at either 36 or 5�C. More survivors of an exposure to 60 krad were capable of recovery and forming colonies on TSA when incubated at 36�C for 1 day than at 5�C for 14 days. This difference in count was considered a manifestation of injury to certain survivors of irradiation.

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Sixty-six (66) Staphylococcus bacterial isolates were withdrawn from separate clinical samples of hospitalized patients with various clinical infections. Conventional bacteriological tests identified the species of all isolates, and standard microbiological techniques differentiated them into CoPS or CoNS. Their biofilm development was followed by an analysis via the MTP (microtiter tissue culture plates) technique, and we then investigated the presence/absence of icaA and icaB, which were qualified in the top-30 potent biofilm-forming isolates. Thirteen isolates (46.7%) showed the presence of one gene, six (20%) isolates exhibited the two genes, while ten (33.3%) had neither of them. The formation of staphylococci biofilms in the absence of ica genes may be related to the presence of other biofilm formation ica-independent mechanisms. CoPS was the most abundant species among the total population. S. aureus was the sole representative of CoPS, while S. epidermidis was the most abundant form of CoNS. Antibiotic resistance was developing against the most frequently used antimicrobial drugs, while vancomycin was the least-resisted drug. The totality of the strong and medium-strength film-forming isolates represented the majority proportion (80%) of the total investigated clinical samples. The biochemical pattern CoPS is associated with antibiotic resistance and biofilm formation and can be an alarming indicator of potential antibiotic resistance.

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