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Wratizolin in the concentration of 1-10 micrograms/ml was found to inhibit the growth of Gram-positive bacteria such as: Staphylococcus, Streptococcus, Sarcina, Corynebacterium, and some representatives of aerobic bacilli. Gram-negative bacteria of Enterobacteriaceae and Pseudomonas were not sensitive to Wratizolin even in the concentration of 100 micrograms/ml.
The microbiological assay for penicillin residues in milk was improved. Acidification of milk with phosphoric acid to pH 4.5, centrifugation to remove precipitated proteinaceous matter, adjustment of pH to 6.0, a second centrifugation, and the use of a 2% agar base layer resulted in the consistent measurement of 0.01 unit penicillin activity/ml milk. Sarcina lutea was used as the assay organism. Recoveries in milk averaged 94%, in nonfat dry milk 84%, in cottage cheese 97%, and in cream cheese 94%.
A laboratory method was developed whereby the presence of Rifampicin in the blood is determined microbiologically by means of a diffusion test. The organism used was Sarcina lutea. The tests established that the Rifampicin levels in the blood of pylorogastrectomized persons were significantly higher then they were in a normal control group. The daily changes in the Rifampicin levels were simulated and checked by analogue computer. The findings indicated that the increased absorption in gastrectomized persons cannot be due to accelerated passage and that it is presumably attributable to chemical and physical factors. The results are analysed statistically and summarized in graphs.
Scleral buckling can be obtained with insoluble hydrophilic polymers that are implanted in the dry state (xerogels, which then expand to a predetermined size by imbibing tissue fluids. Absorbable gelatin, nonabsorbable poly(hydroxyethyl methacrylate) (PHEMA), and poly(glyceryl methacrylate) (PGMA), have been implanted as xerogels in scleral buckling procedures. Gelatin, PHEMA, and PGMA are soft when hydrated, but are hard and brittle in the dehydrated state. However, poly(hydroxyethyl acrylate) (PHEA) is soft not only in the dehydrated state. However, poly(hydroxyethyl acrylate) (PHEA) is soft only when hydrated but also when dehydrated. Dry PHEA can be carved easily to shape and size, and because it is soft it could be very useful for operations on thin, weakened sclera. We have implanted PHEA intrasclerally and suprasclerally in rabbit eyes. Tolerance of PHEA appears to be as good as that of other materials in clinical use. We have impregnated PHEA and gelatin implants with antibiotics to achieve prolonged antibiotic delivery to the surgical site. When dried impregnated gels were assayed for antibiotic activity in agar plates with Sarcina lutea, both gels displayed high but rapidly decreasing activity.
As part of the examination of emergency-slaughtered animals for the presence of antibiotic residues, studies were done to see whether false-positive results would be obtained when the Sarcina lutea kidney test and Bacillus subtilis BGA test were performed. When the S. lutea kidney test was positive in cattle, calves and swine, penicillin was invariably found to be present in those animals, the histories of which showed that they had not been given antibiotics. A syringe and an injected fluid containing penicillin residues are regarded as possible causes of these positive results. When the S. lutea kidney test was performed in horses which had been in a state of stress prior to slaughter, false-positive results were occasionally observed. When the German B. subtilis BGA test was used, a large number of false-positive results were recorded, among others in equine kidneys. This shows that the use of this test in examining the kidney is a highly controversial matter. A number of drugs used in veterinary medicine may have an inhibitory effect on the growth of S. lutea and B. subtilis BGA test organisms in vitro. When these drugs were used therapeutically (in vivo), the result of the S. lutea kidney test was not positive in any of the cases studied. On the other hand, false-positive results were obtained when the B. subtilis BGA renal medullary test was performed in those animals in which lidocaine and calcium borogluconate had also been injected.
A lysozyme-like enzyme isolated from the culture broth of Staph. aureus 712 presented in its native state a lipoproteid complex. The lytic and antibacterial spectrum of the enzyme was similar to that of the egg albumin enzyme. However, the lipoproteid complex was somewhat superior to the egg albumin complex in its activity against Micrococcus lysodeikticus, a number of gramnegative bacteria and staphylococci. Out of the organisms studied Microccus lysodeikticus, Sarcina and Bac. subtilis proved to be most sensitive to the both enzymes. Comparison of the amount of the enzyme formed in the culture medium with its minimum inhibitory concentration with respect to most of the microbes tested provided a supposition that the lipoproteid enzyme did not play a significant role in the process of the microbial antagonism.
Both the analytical and preparative methods by which the preparations of 26a bydrochloride salt with a high antibacterial activity and 20--30% recovery have been obtained from the fermentation fluids of Bacillus subtilis are presented. On an industrial scale the antibiotic can be yielded by absorption of bioactivity on Amberlite CG-50I column and precipitation with picric acid of crude substance from active elutes as adduct which was divided on equilibrated CM--cellulose and finally purified by gel filtration on Sephadex G-25 column. The purified preparation gave a single band by SDS-polyacrylamide gel electrophoresis and one ninhydrin-positive spot by thin-layer chromatography on silica gel G plates corresponding to single zones of bioactivity on bioautograms, and moved as a single peak of almost constant antibacterial activity on Sephadex G-75, G-100 and G-200 columns. The potency of the purest preparations, lot Sephadex G-25, was 6,500--7,000 arbitrary units/mg, and were characterized as follows: purification factor, 57; purity of 98--100% by densitometer scans of SDS-polyacrylamide gels; MIC for Sarcina lutea by twofold agar dilution assay, 0.306 microgram/ml.
The following microbiological tests: the Bacillus subtilis BGA (Bundes-Gesundheitsamt) test and Sarcina lutea test as well as the test bacteria Bacillus stearothermophilus var. calidolactis and E. coli were used to examine whether drug residues were detectable in broiler chickens during and after treatment with various drugs. With the exception of the occidiostat Esb3, residues were not found to be present using the two above tests. On the other hand, residues of a number of drugs were detected in some interior organs and faeces during treatment when the other test bacteria were used. Residues were no longer detected in the faeces, however, within twelve hours after treatment had been discontinued.
Two methods described in the AOAC Official Methods of Analysis for the detection of penicillin residues in whole milk were evaluated to determine the capability of each method to detect residues of 12 antibiotics used in the dairy industry. The first method, a cylinder-plate method that uses Sarcina lutea as the test organism, detected levels of 1 ppm of 8 of the 12 antibiotics tested. The second method, using paper disks with Bacillus subtilis as the test organism, detected approximately 1 ppm of only 4 antibiotics. This disk method was unable to detect less than 40 ppm of 5 of the antibiotics tested. The data indicate that the S. lutea cylinder-plate technique is more sensitive to more antibiotics than the B. subtilis disk method and is far superior for screening purposes.
Radioresistance of lactose positive and lactose negative Esch. coli, lactose positive Esch. coli and proteus, yellow sarcina and white staphylococcus, white and pink yeasts, white and yellow staphylococcus was studied after irradiation and seeding on hard media using separate and combined methods. In most cases radioresistance of the microbes did not depend of exposure conditions. However, lactose positive Esch. coli irradiated with proteus increased proteus radioresistance to its own standard. Yellow staphylococcus cannot form yellow pigment after irradiation with a dose of 1000 Gy.
Endogenous luminescence of the luciferin-luciferase extract from firely tails was studied in determing low concentrations of ATP. The optimum concentration of the the extract, corresponding to the minumum effect of endogenous luminescence, was found in the reaction medium. The solution of luciferin-luciferase was unstable at room temperature and upon dilution. The activity of luciferin-luciferse solutions did not change after freezing in liquid nitrogen with following thawing. The content of ATP was assayed in the cells of Sarcina flava disintegrated with ultrasound.
The cytotoxin P4 from the venom of the cobra snake Naja nigricollis was examined for activity against aerobic gram-positive and gram-negative bacteria, yeasts, fungi and eucaryotic cell lines by determination of minimal inhibitory concentrations (MIC) and IC50 values, respectively. Cytotoxin P4 exhibits antimicrobial activity against Bacillus subtilis, Micrococcus flavus and Sarcina lutea. Targets in gram-negative bacteria and fungi apparently were not reached. Toxicity against eucaryotic cells is in a narrow range between lethal and tolerable concentrations.
Experimental scleral buckling was obtained in rabbits by using expanded silicone rubber implants under scleral trap doors. Buckle heights ranged from 2.3 to 4mm after injection of 0.05 to 0.15 ml of fluid into the implants. Therate of decrease in buckle height followed up opthalmoscopically for five months, was found to be slow and continous and was caused mainly by loosening by the scleral flaps rather than by the diffusion of fluid from the implants. Implants expanded with chorampenicol solutions provided sustained release of the antibiotic in the area of the operation. This was confirmed in agar plantes by inhibition of the growth of Sarcina lutea around subimplant tissues and the expanded implants that were recovered post mortem. These implants provided an opportunity of modify the buckle height easily, either during the procedure or postoperatively.
Whole cells of Micrococcus luteus (formerly Sarcina lutea ATCC 9341) have been covalently linked to a carboxymethylcellulose support system, with the retention of histidine ammonia-lyase activity. The dependence of the rate of urocanic acid formation on pH, temperature, and added surfactant concentration was similar for the free and the immobilized cells. The immobilization procedure used is based on the carbodiimide activation of carboxymethylcellulose and has been optimized for the histidine ammonia-lyase activity of the immobilized cells on a given weight of cellulose. In a column reactor at 23 degrees C and superficial velocity of 0.044 cm/min, 5 g of cellulose with bound cells gave a 35% conversion of an L-histidine solution (0.25M, pH 9.0) to urocanic acid for 16 days of continuous operation. The scope of this carbodiimide assisted immobilization procedure has been investigated for a series of microorganisms and a variety of carboxylate functionalized supports.
A number of gram-negative and gram-positive bacteria species was screened for the expression of the gram-negative plasmid pACK5 and pACT72 with replicon of pAC1 plasmid from Acetobacter pasteurianus. As was described previously, both plasmids were expressed in Escherichia coli, Acetobacter pasteurianus, Acetobacter aceti, Shigella spp. and Citrobacter spp. Expressions of plasmids were successful in twelve species tested, Comamonas terrigena, Salmonella typhimurium, Serratia marcescens, Bacillus cereus, Bacillus megatericum, Bacillus subtilis, Lactobacillus helveticus, Micrococcus luteus, Sarcina lutea, Staphylococcus aureus, Staphylococcus epidermidis, Streptoccocus feacalis, and the stability of plasmid DNA was tested after cultivation in non-selective conditions.
Bacteria such as Staphylococcus, Lampropedia, and Sarcina develop in characteristic two-or three-dimensional groups of cells. We propose here a model of how bacteria may generate such groupings by an extension of an earlier model for rod-shaped bacteria. No other mechanism for forming two- or three-dimensional structures of groups of cells has been proposed. Our earlier model for division of rod-shaped bacteria into nearly equal-sized daughters assumed that the origin and terminus DNA were attached at a critical time to polar wall sites. While such binding was speculative 20 years ago, it has now been established that the DNA for the origin of replication, at least during some part of the cell cycle is located in the pole for several different bacteria. Evidence is also building showing that the terminus DNA region is sometimes located at a position in the cell that will develop into two new poles. Here, a new extension of the concept that polar sites bind specifically origin and terminus DNA of the chromosome is presented that can explain how division takes place in one and then in another dimension to form two-dimensional tablets of four cells or large planar arrays. A further possible extension to three dimensions to generate octets of cells is proposed.
An antifungal substance named peptide A12-C has been purified to homogeneity from supernatants of sporulated cultures of Bacillus licheniformis A12. It consists of a 0.77-kDa hydrophilic peptide containing two residues of Glu and one of Arg, Ala, Pro, Tyr and Orn. No fatty acids, phosphorus or carbohydrates have been detected. Peptide A12-C is active on several fungi (Microsporum canis CECT 2797, Mucor mucedo CECT 2653, M. plumbeus (CCM F 443, Sporothrix schenckii CECT 2799 and Trichophyton mentagrophytes CECT 2793) and bacteria (Bacillus megaterium, Corynebacterium glutamicum, Sarcina and Mycobacterium), although the latter are less sensitive.
Compliance with penicillin prophylaxis after splenectomy was studied in 42 thalassemic children and adolescents. Urine samples were tested five times per patient for the presence of penicillin by the Sarcina lutea inhibition test. Only 7% of patients were found to be absolute noncompliers, while an additional 14% had a compliance considered to be insufficient. Noncompliers tended to have been splenectomized more than 5 years before, while couples of affected siblings were uniformly full-compliers. No relation was found with age, presence of healthy siblings in the household, chronic disease or previous severe infections. Knowledge of the risks of severe infection after splenectomy was uniformly good. We conclude that compliance with penicillin prophylaxis in splenectomized thalassemics is good (79%) and that close contact between patients and medical staff is important in its promotion.