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Biomedical subjects

M R Moody

Publications and source records attributed to M R Moody.

44 records · Page 3Linked to original sources
PubMed1972

In vitro antibiotic susceptibility of pseudomonads other than Pseudomonas aeruginosa recovered from cancer patients.

The increase in occurrence of infections due to opportunistic gram-negative bacilli in patients with impaired host defenses emphasizes the need for information on the antibiotic susceptibility of the organisms that colonize such patients. During a 20-month period, more than 100 pseudomonads which were not Pseudomonas aeruginosa were recovered from cancer patients at the Baltimore Cancer Research Center. These included P. fluorescens, P. putida, P. multivorans (cepacia), P. maltophilia, P. stutzeri, P. alcaligenes, and P. pseudoalcaligenes. Susceptibility tests with 12 antibiotics indicated that the intraspecies antibiograms for many of these species were more uniform than those of P. aeruginosa. The stability of susceptibility patterns allowed the antibiograms to be used as aids in the preliminary differentiation of these organisms. Variable antibiogram patterns were noted among certain species, i.e., P. fluorescens, P. stutzeri, and P. multivorans, whereas each of the other species had essentially one pattern. These in vitro studies showed that some of the Pseudomonas species other than P. aeruginosa were resistant to a number of antibiotics. Among these were antibiotics that are in general use for P. aeruginosa infections. Such differences in antibiotic susceptibilities emphasize the necessity for careful speciation of this group of microorganisms to assure proper epidemiological documentation of colonization and infection, as well as to ensure therapy with an antimicrobial agent to which the organism is susceptible in vitro.

Anti-Bacterial Agents↗
PubMed1969

Effect of cultural environment on the blood group activity of microorganisms.

Blood group activity was proven to be a property of the bacterium per se which possesses it, although such activity was influenced by the cultural environment of the organism. High concentrations of peptones having blood group activity were able to transfer this activity to inactive organisms; however, the conferred activity was proportional to the concentration. As a result of the low concentrations, the blood group activity of peptones was eliminated upon incorporation in culture media, and the activity of the peptones had no effect on the blood group activity levels of microorganisms when grown in these media. Conversely, the vitamin content of culture media did affect blood group active organisms. Multiple vitamins in media decreased the activity levels by blocking the reactive sites of the active organisms on which activity detection depended. Blood group activity levels were highest in media of minimal or no vitamin content. Therefore, it can be concluded that a choice of cultural medium becomes an important factor in the quantitation of bacterial blood group activity.

Blood Group Antigens↗
PubMedDate not supplied

Moxalactam and piperacillin: a study of in vitro characteristics and pharmacokinetics in cancer patients.

We evaluated the microbiologic characteristics including MIC determinations, synergy plate assays and serum bactericidal activity for two regimens being examined as empiric antibiotic therapy for febrile granulocytopenic cancer patients. The regimens consisted of moxalactam (4 g.i.v. q12h) plus piperacillin (75 mg/kg i.v. q6h) or moxalactam (as above) plus amikacin (levels adjusted to one hour post-infusion levels of 25 mg/l and troughs of 6-8 mg/l). Detailed pharmacokinetics were ascertained for the beta lactams. All drugs were active against a panel of 11 strains each of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. The pharmacokinetic profile showed serum levels sufficient to provide good antimicrobial activity throughout the dosing interval. Both regimens displayed synergistic or partially synergistic activity in the main for the test organisms; moxalactam plus piperacillin produced good results against S. aureus and P. aeruginosa. In the serum bactericidal assays, the moxalactam-piperacillin combination produced significantly higher mean titers at both peak and trough when compared to the moxalactam-amikacin regimen. This may be because moxalactam acts as a beta lactamase inhibitor for both staphylococcal beta lactamase, as well as the Sabath-Abraham Id type beta lactamase carried by P. aeruginosa (among others). Moxalactam-piperacillin deserves extensive evaluation as empiric therapy for the febrile neutropenic cancer patients.

Amikacin↗
PubMedDate not supplied

Integration of selected pharmacologic and microbiologic properties of three new beta-lactam antibiotics: a hypothesis for rational comparison.

To enable the comparison of antibiotics in a standardized, meaningful manner, a system that integrates the pharmacologic and microbiologic properties of beta-lactam antibiotics has been developed. The system compares the duration of time that concentrations of both total and free drug exceed the 90% minimal inhibitory concentration ( MIC90 ) of various pathogens as well as the area under the concentration-time curve for both total and free drug, the latter measurement being an indication of potential for antibiotic diffusion to the periphery. Of the three cephalosporin(-like) compounds evaluated, moxalactam produced the longest duration of free drug above the MIC90 for the Enterobacteriaceae as well as the largest free-drug area under the concentration-time curve following a standardized 2-g intravenous infusion. Both the duration of time cefotaxime was above the MIC90 for the Enterobacteriaceae and the area under the concentration-time curve were significantly less because of its short elimination half-life, results indicating the need for more frequent dosing with cefotaxime than with moxalactam. Cefoperazone, because of its high degree of protein binding and higher MIC90 , develops the least duration of time above the MIC90 for most pathogens. None of these new agents provides free-drug concentrations above the MIC90 for Pseudomonas aeruginosa for longer than 0.6 hr, which suggests that they may be inadequate as single-agent therapy for many serious infections due to this pathogen. Because promotion of comparisons by this method relies on in vitro data for analysis, the conclusions relating to expected clinical efficacy are proffered and should be interpreted with caution.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗