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D Sompolinsky

Publications and source records attributed to D Sompolinsky.

At least 37 records · Page 2Linked to original sources
PubMed1979

Further studies of a new pathogenic mycobacterium (M. haemophilum sp. nov.).

Mycobacterium haemophilum is an acid-fast rod-shaped organism, originally isolated from deep subcutaneous granulomata of a patient with Hodgkin's disease. Like the other two mycobacterial skin-pathogens, M. ulcerans and M. marinum, M. haemophilum has a maximum temperature for growth below 37 degrees C. Mycobacterium haemophilum is distinguished from all other species examined by its requirement of haemin for growth and its complete lack of catalase activity. Extraneous catalase cannot replace haemin as a growth factor for this organism. Mycobacterium haemophilum can also be differentiated from other species by the patterns of electrophoresis of protein extracts and by gas-liquid chromatography of saponificated and methylated lipid extracts. A monospecific-agglutinating antiserum against M. haemophilum was obtained by adsorption of an immunoserum with M. intracellulare. A number of slow-growing mycobacterial species develop on monolayers of McCoy fibroblasts, and growth on these tissue cultures can be observed much earlier than on artificial media. Mycobacterium haemophilum is characterized by exclusively intracellular development.

Aerobiosis↗
PubMed1978

A case of listeriosis in pregnancy with fetal survival.

Listeriosis during pregnancy is generally considered to result in an intrauterine infection which affects the fetus before birth or in the perinatal period. A case of listeriosis in a 38-yr-old diabetic woman with an influenza-like disease in her 32nd wk of pregnancy is presented. Two successive blood cultures were positive for Listeria monocytogenes type 4b and her serum showed a rising titer for agglutinins to this organism. After antibiotic treatment of the patient she gave birth to a healthy child.

Adult↗
PubMed1978

Transport of tetracyclines through the bacterial cell membrane assayed by fluorescence: a study with susceptible and resistant strains of Staphylococcus aureus and Escherichia coli.

The fluorescence of 12 tetracyclines in buffered solutions was measured by excitation at 400 nm and emission at 520 nm. The fluorescence varied markedly for different tetracyclines at equivalent concentrations. Demethylchlortetracycline exhibited more fluorescence than both chlortetracycline and demthyltetracycline; minocycline was virtually non-fluorescent at the conditions of the study. Fluorescence was highly dependent on the polarity of the solvent; when the buffer solution in water was replaced by a solvent containing 50% methanol, fluorescence increased significantly, but to various degrees for different tetracyclines. The most striking influence of the addition of methanol was observed for doxycycline (5-oxy 6-deoxy-tetracycline), whereas the influence on anhydrotetracycline was negligible. When suspensions of a susceptible strain of Staphylococcus aureus were added to solutions of tetracyclines, membrane permeation of the drugs could be monitored by an increase in fluorescence. This increase varied strikingly with the different drugs and could not be correlated with the concentrations for 50% growth inhibition (Ki). This might be due to the quantitative variations in the intracellular level corresponding to a certain external concentration of the respective drug. When tetracycline-resistant strains of S. aureus and Escherichia coli were exposed to tetracycline, the intensity of fluorescence observed was less than for the corresponding susceptible strains; in spite of this, the quantitative differences of fluorescence exhibited by the susceptible and resistant strains seemed slight in relation to the differences in susceptibility. It was demonstrated that minocycline inhibits the membrane transport of tetracycline in S. aureus and E. coli. This inhibition seems to be competitive for S. aureus, but not for E. coli.

Biological Transport↗
PubMed1977

Lymphocutaneous nocardiosis due to nocardia brasiliensis.

A farmer had chaining lymphocutaneous granuloma on the right hand and arm. Clinically the syndrome seemed typical for sporotrichosis. Bacteriological examination revealed Nocardia brasiliensis as the only etiologic agent. Since 1920, eight similar cases of sporotrichoid nocardiosis have been reported from various parts of the world. To our knowledge, isolation of N brasiliensis has not been reported previously in this geographical area.

Diagnosis, Differential↗
PubMed1976

[Chlamydia].

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Chlamydia↗
PubMed1976

Isolation and characterization of tetracycline resistance proteins from Staphylococcus aureus and Escherichia coli.

Immunoglobulin (adsorbed resistance antiserum) reacting specifically with antigens from tetracycline (Tc)-resistant Staphylcoccus aureus or Escherichia coli was produced by adsorbing immunoglobulin against cell envelopes of resistant strains with envelope extracts from the respective isogenic susceptible strains. Adsorbed resistance antiserum against S. aureus reacted with envelope extracts from 32 Tc-resistant strains and failed to react with similar extracts from 76 Tc-susceptible strains of S. aureus. An antigen (Tc resistance antigen [TRA]) found only in Tc-resistant strains was produced by adsorbing envelope extracts from these strains with immunoglobulin against envelopes from isogenic Tc-susceptible strains. On immunodiffusion no cross-reactivity between TRAs from S. aureus and E. coli was observed. The TRAs behaved as proteins. The molecular weight of TRA from S. aureus was determined to be 32,000 and from E. coli to be 50,000. Data obtained by preliminary amino acid analysis of the TRAs are presented.

Antigens, Bacterial↗
PubMed1976

Biological and ecological investigations on thiamineless dwarf-colony variants of Staphylococcus aureus of bovine udder origin.

Thiamineless dwarf-colony variants of Staphylococcus aureus (D strains) were compared with their homologous normal-colony variants and with normal S aureus. The majority of D strains tested in vitro exhibited biological features typical of S aureus. D strains, however, produced lower titres of alpha-haemolysin and this toxin was also produced by a smaller proportion of these strains. D strains and S aureus strains were equally susceptible to disinfectants used in dairy farming and were isolated with similar frequency from the skin of the udders of infected cows. Attempts at inducing and selecting D strains from normal S aureus by exposing the latter to antibiotics in vitro and in vivo have so far failed.

Animals↗
PubMed1976

Studies on the pathogenicity of thiamineless dwarf-colony variants of Staphylococcus aureus isolated from the bovine udder.

The pathogenic characteristics of thiamineless dwarf-colony variants of Staphylococcus aureus (D strains) were compared with those of normal S aureus isolated from the bovine udder. Intravenous injection of D strains into embryonated hen's eggs and intracranial inoculations into mice produced similar results to those with normal S aureus. Intramammary infusion of D strains into normal cows resulted in mastitis which was indistinguishable from the type produced by infusion of S aureus. Intramuscular injection of thiamine HCl into cows with chronic mastitis due to D strains did not alter the course of the disease, although normal sized S aureus colonies were isolated several days after thiamine injection.

Animals↗
PubMed1976

Isolation of Mycoplasma from the placenta after cesarean section.

Placentas obtained at cesarean section were cultured for Mycoplasma and other microorganisms in 123 randomly selected patients in order to evaluate the incidence of Mycoplasma, to identify factors which may contribute to their presence, and to correlate their presence with the occurrence of postpartum infection. Twenty-eight placentas (22.8%) yielded Mycoplasma positive cultures. The incidence of Mycoplasma in the placenta was significantly higher in patients with ruptured membranes. The incidence of postpartum fever was significantly higher (P less than 0.01) in cases positive for Mycoplasma as compared to cases in which the placenta was negative for Mycoplasma. Findings were similar for both groups with regard to the incidence of unexplained postpartum fever. The results of this study suggest that Mycoplasma may be considered a relatively frequent pathogen and should be considered a possible cause of postpartum fever.

Cesarean Section↗
PubMed1975

Infections with mycoplasma and bacteria in induced midtrimester abortion and fetal loss.

Placentas and fetuses from cases of induced midtrimester abortion and fetal loss (13 weeks of pregnancy or more) were examined microbiologically. In the series of midtrimester fetal loss, bacteria were isolated in 14 per cent and genital Mycoplasma in 37 per cent of the placentas. In induced abortion, 18 per cent of the placentas grew bacteria and in only one case out of 27 was a Mycoplasma strain isolated. Fetal organs yielded cultures positive for bacteria in 16 per cent and for genital Mycoplasma in 23 per cent of the spontaneous fetal loss material, whereas pyogenic cocci were isolated from fetal organs in 18 per cent and Mycoplasma in no case of induced abortion. In the positive cases, the fetal lungs were most often infected (in 34 out of 37 positive cases of spontaneous and 4 out of 5 positive cases of induced abortion). On the other hand, microorganisms could be isolated from the brain in only 5 out of 28 cases of spontaneous and none of induced abortion. In the series of fetal loss, positive microbiologic findings from the fetal organs seemed correlated to prolonged bleeding before abortion or labor and to premature rupture of membranes.

Abortion, Induced↗
PubMed1974

Growth of Chlamydia trachomatis in McCoy cells treated with cytochalasin B.

When the fungal metabolite cytochalasin B was added to McCoy cells, multinucleated giant cells developed. Monolayers of these cells proved as efficient as irradiated cells for the growth of three different serotypes of Chlamydia trachomatis and for the primary isolation of chlamydiae from clinical specimens obtained from patients attending a venereal disease clinic. Cytochalasin treatment of McCoy cells provides a convenient alternative to irradiation and should be of value in the isolation of chlamydiae from the eye and genital tract.

Cell Nucleus↗
PubMed1974

Epidemiological and biochemical studies on thiamine-less dwarf-colony variants of Staphylococcus aureus as etiological agents of bovine mastitis.

Dwarf-colony (D) variants of Staphylococcus aureus are relatively widespread etiological agents of bovine mastitis in Israel. D strains grow on ordinary solid nutrient media with pinpoint, transparent colonies. An epidemiological study indicated that these variants are more communicable than normal (N) S. aureus strains. Biochemically, several types of metabolic defects have been demonstrated among the D strains: strains from one herd were pantothenate-less, most of the other isolates were thiamine-less, and a few of them were both thiamine-and pantothenate-less. Among the thiamineauxotrophs were a few (from one herd) which were unable to concentrate thiamine-thiazole, whereas all of the other strains required thiamine-pyrimidine (HMP) in the form of pyrophosphate (HMP-PP). At least some of these D strains were defective in three functions: concentrative uptake of HMP, phosphorylation of HMP, and phosphorylation of HMP-monophosphate. Since mutants with normal growth occurred readily, we assumed that the information for these three functions exists on a polycistronic operon. Quantitative requirements for HMP-PP varied highly among the D strains, and other data also indicated that HMP-PP-requiring strains had not developed from a common source.

Animals↗