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J T Parisi

Publications and source records attributed to J T Parisi.

At least 37 records · Page 2Linked to original sources
PubMed1980

Plasmid profiles in epidemiologic studies of infections by Staphylococcus epidermidis.

Plasmid profiles of cultures of Staphylococcus epidermidis obtained by agarose gel electrophoresis were used, in conjunction with phage typing, biotyping, and antibiograms, in epidemiologic studies of infections in neonates and patients with cancer. In some cases, patients had cultures that were lysed by a single phage, belonged to the same biotype, and had identical antibiograms, but had distinctly different plasmid profiles. In other instances, almost identical plasmid profiles were observed in cultures lysed by a single phage, belonging to the same biotype, and with markedly different antibiograms. The plasmid profile technique was valuable in detecting distinct strains of S. epidermidis, and its use could be helpful in epidemiologic studies of infections by other organisms.

Bacteriological Techniques↗
PubMed1980

Characterization of the tobramycin-kanamycin-neomycin resistance plasmid in Staphylococcus epidermidis.

A strain of Staphylococcus epidermidis was transduced to tobramycin resistance and all transductants were also resistant to kanamycin and neomycin. Results of curing studies also indicated that these resistances were controlled by a single determinant on a plasmid. Agarose gel electrophoresis of the plasmid DNA from parent, cured, and transduced strains showed a single plasmid was responsible and its molecular weight was calculated to be 2.85 x 10(6). Attempts to determine other properties of the organism controlled by this plasmid were unsuccessful.

Anti-Bacterial Agents↗
PubMed1979

Bacteriophage typing of coagulase-negative staphylococci.

Cultures comprising the 10 species of coagulase-negative staphylococci proposed by Kloos and Schleifer (J. Clin. Microbiol. 1:82--88, 1975) were typed with bacteriophages isolated from Staphylococcus epidermidis. Although only 10.5% were typable, 50% of those identified as S. epidermidis were typed. Cultures from patients with middle ear infections were also classified by this system and phage typed.

Bacteriophage Typing↗
PubMed1979

Transduction of penicillinase production in Staphylococcus epidermidis and nature of the genetic determinant.

Four strains of Staphylococcus epidermidis from clinical sources were capable of serving as donors for the transduction of either penicillinase production, ethidium bromide resistance, or tetracycline resistance. Three typing phages served as transducing phages and, depending upon the combination of transducing phage, donor strain, and recipient strain, the rates of transduction ranged between 10(-5) and 10(-9). In one strain, cotransduction of penicillinase production and ethidium bromide resistance was observed. Although ultraviolet irradiation kinetics indicated that both the tetracycline resistance and the penicillin resistance determinants were located on plasmids, only resistance to tetracycline could be eliminated by growth in the presence of curing agents or at elevated temperature. However, evidence was obtained by agarose gel electrophoretic studies that both the tetracycline resistance and the penicillin resistance determinants are located on separate plasmids in this organism.

Drug Resistance, Microbial↗
PubMed1977

Nature of the genetic determinant controlling encapsulation in Staphylococcus aureus Smith.

Two strains of Staphylococcus aureus, Smith and M, were studied for the elimination of encapsulation. For S. aureus M, encapsulation was stable. For S. aureus Smith, spontaneous loss of encapsulation was 1.3% and increased markedly in medium containing surface-active agents. In the presence of sodium dodecyl sulfate, unencapsulated cells had a considerable selective advantage. Attempts to demonstrate covalently closed circular plasmid deoxyribonucleic acid were unsuccessful. In cultures of unencapsulated cells, encapsulated cells were observed occasionally. These data argue against a plasmid location for the determinants controlling encapsulation in this organism in spite of a high spontaneous loss of this character.

Chromosomes, Bacterial↗
PubMed1977

Development of a bacteriophage-typing set for Staphylococcus epidermidis.

Six phages isolated from lysogenic cultures of Staphylococcus epidermidis were used to type cultures in our collection classified previously as "untypable" with our original typing set of 13 phages, new clinical isolates from Missouri, and clinical isolates from Connecticut, Georgia, Pennsylvania, and Virginia. Typability with the new set of 6 phages and with our 13 original phages was compared. For 203 cultures, 81 (39.9%) cultures were typable with the set of 6 phages and 73 (36.0%) cultures were typable with the set of 13 phages. When the two typing sets were combined, the percentage of typability for 425 cultures increased to 49.9%. compared with 35.7% with the original set of 13 phages. For 109 cultures from outstate, the percentage of typability was 56.9%, whereas that for 316 cultures from Missouri was 47.5%. When only cultures in biotype 1 were considered, the percentage of typability for 268 cultures with the combined set increased to 58.2%, compared with 39.5% with the original set of 13 phages. Analysis of individual reactions for all 425 cultures typed in our laboratory indicated that 11 of the 19 phages in the combined set accounted for the majority of the reactions, and a provisional set containing these 11 phages is proposed.

Bacteriophage Typing↗
PubMed1976

Location of the coagulase gene in Staphylococcus aureus.

Evidence is presented for the chromosomal location of the coagulase determinant in most strains of Staphylococcus aureus. By the use of a pour-plate technique, transduction of the capacity to produce coagulase to a coagulase-negative mutant of S. aureus was studied. The frequencies of transduction were low unless the transducing phage was exposed to ultraviolet irradiation and the recipient was lysogenised with the transducing phage. Attempts to transfer the coagulase gene from S. aureus to S. epidermidis were not successful.

Coagulase↗
PubMed1976

Phage typing of Staphylococcus epidermidis.

Thirteen phages were isolated from lysogenic cultures of Staphylococcus epidermidis from a clinical laboratory and used to type 223 clinical isolates of this organism. The 18 phages isolated in The Netherlands were used to type these same cultures. No correlation was observed between phage type, biotype, or clinical source of isolation. At phage concentrations of 100 times the routine test dilution, 35.0% of the cultures were typable with out phages and 21.5% were typable with the phages from The Netherlands. When only cultures in biotype 1 were considered, 43.3 and 24.1% of 141 cultures were typable with our phages and those from The Netherlands, respectively. The lytic reactions obtained with our phages were generally stronger and easier to read and the lytic patterns were, almost invariably, shorter. The typability of untypable cultures was increased 12.0% by incubation at 45 C prior to phage typing and 20% by heat shock (55 C for 5 min) prior to typing. Phage typing 5 subcultures of 20 typable cultures on 5 successive days showed that the lytic patterns were reproducible. The present status of phage typing S. epidermidis and the work needed to obtain a set of typing phages for epidemiological studies of infections by this organism are discussed.

Bacteriophage Typing↗
PubMed1975

Transmissible drug resistance of Escherichia coli and Salmonella from humans, animals, and their rural environments.

Isolates of Escherichia coli and Salmonella species obtained from humans, animals, and their rural environments were tested for their ability to transfer multiple drug resistance to competent recipients. In all, 125 (52.9%) of 242 isolates of E.coli transferred all or part of their resistance to E.coli CSH-2, and 103 (44.4%) of 232 isolates of E.coli transferred all or part of their resistance to Salmonella choleraesuis var. kuzendorf 214. The data suggest that the multiple drug resistance of E.coli transferred all or part of their resistance to Salmonella choleraesuis var kuzendorf 214. The data suggest that the multiple drug resistance of E. coli in the gut of humans who work with livestock may be due to the transfer of resistance determinants from animal strains to the resident flora of the human gut. Such transfer could occur during transient passage through the digestive tract. Multiple drug-resistant Salmonella were isolated from all sources. In all, 48 (80%) of 60 isolates of Salmonella transferred all or part of their resistance to E. coli CSH-2, and isolates of Salmonella transferred all or part of their resistance to E.coli CSH-2, and 42 (82.4%) of 51 isolates of Salmonella transferred all or part of their resistance to S. choleraesuis var, kuzendorf 214. Fifty-three (46.9%) of 113 antibiotic-sensitive isolates of E.coli possessed resistance transfer factor, and six (23.1%) of 26 isolates with resistance transfer factor mobilized resistance determinants in isolates unable to transfer drug resistance during conjugation experiments.

Animals↗
PubMed1975

Virulence factors of biotypes of Staphylococcus epidermidis from clinical sources.

The biotyping scheme of Baird-Parker was applied to cultures of Staphylococcus epidermidis from patients. In all, 63.6% of 228 cultures belonged to biotype 1, followed by biotypes 4, 3, and 2 in decreasing order of incidence. When classified according to clinical source of isolation, cultures of S. epidermidis were most frequently isolated from urine, with 39.5% of 228 cultures from this source. Each of the four biotypes was distributed throughout all nine catagories of clinical sources. The production of virulence factors was based on the results of three groups of tests: (i) deoxyribonuclease, urease, gelatinase, caseinase, and lysozyme production; (ii) lipolytic activity on the tweens; and (iii) hemolysin production. Enzymatic activity was highest for organisms in biotypes 1, followed by biotypes 3, 4, and 2 in decreasing order. Of the 228 cultures, 76.3% were lysed by lysostaphin. Resistance to antibiotics was highest for tetracycline, ampicillin, and penicillin, with rates of 54.8, 69.3, and 81.6%, respectively. The role of S. epidermidis as an etiological agent was studied by analyzing the laboratory and clinical data of 80 patients selected at random with bacteriuric S. epidermidis. Organisms in biotype 1 were most commonly associated with urinary tract infection. The significance of certain biotypes of S. epidermidis as opportunistic pathogens among compromised hosts in a hospital environment is discussed.

Anti-Bacterial Agents↗
PubMed1973

Significance of Staphylococcus epidermidis in the clinical laboratory.

Susceptibility to 11 antibiotics was determined for 63 cultures of Staphylococcus aureus and 63 cultures of Staphylococcus epidermidis obtained at random from the clinical laboratory. The incidence of resistance to nine of these antibiotics was greater for S. epidermidis than for S. aureus. Studies of the minimal inhibitory concentration of these cultures to clindamycin showed that 61 cultures of S. aureus were susceptible whereas only 46 cultures of S. epidermidis were susceptible to this antibiotic. Although cultures of S. aureus were more active in the production of seven virulence factors, some cultures of S. epidermidis produced virulence factors. By successive cultivation in increasing concentrations of clindamycin, resistant variants were obtained for 10 cultures of S. aureus and 3 cultures of S. epidermidis. The presence of subinhibitory concentrations of clindamycin inhibited the production of some virulence factors by the resistant variants. In view of the greater resistance of S. epidermidis to antibiotics and its ability to produce virulence factors, its isolation in the clinical laboratory should not be regarded lightly.

Anti-Bacterial Agents↗
PubMed1973

Pour-plate method for the detection of coagulase production by Staphylococcus aureus.

A pour-plate method is described for the detection of coagulase production by Staphylococcus aureus. Either Brain Heart Infusion agar or yeast extract-Trypticase soy agar containing swine plasma was the best medium for the detection of coagulase by this method. The advantages of this method and its potential utilization in the clinical laboratory, in food microbiology, and in specialized studies with S. aureus are discussed.

Agar↗
PubMed1971

Bacteriophage types and O antigen groups of Escherichia coli from urine.

Urinary strains of Escherichia coli from seven geographical regions were typed serologically for O-specific antigens and with phages capable of lysing the majority of urinary isolated. The O antigen groups 4, 6, 75, 1, 50, 7, and 25 were the common ones found. Of the 454 cultures tested, 66.1% were phage typable and 65.2% were serotypable with the 48 antisera employed. Also, 71.6% of the cultures for which an O group could be determined were phage typable. Furthermore, of those seven O-antigen groups implicated in urinary tract infection, 80.2% exhibited a phage pattern. Various phage types were found within an O-antigen group, and, although one phage type associated a high percentage of the time with one O-antigen group, no correlation was observed between other O-antigen groups and phage types. Studies with bacteriuric patients by phage typing showed the presence of two strains of E. coli within an O-antigen group. Serogrouping and phage typing of fecal isolates of E. coli revealed the presence of some O-antigen groups and phage types also found as predominant types among urinary isolates. Phage typability correlated highly with hemolysis of human erythrocytes. Elevated temperatures of incubation and a chemical curing agent were used to enhance typability of cultures refractory to the typing phages. Phage typing, due to its rapidity, ease, and ability to distinguish strains of E. coli within an O-antigenic group, is suggested as a possible method by which a better insight into the epidemiology of urinary tract infections may be obtained.

Anti-Bacterial Agents↗