Viola M. Young

Empiric Therapy with Carbenicillin and Gentamicin for Febrile Patients with Cancer and Granulocytopenia

Abstract Seventy-five acutely ill, febrile patients with cancer and granulocytopenia were treated empirically with a combination of carbenicillin and gentamicin for presumed bacterial infection. Cultures taken before the initiation of antibiotics subsequently documented the presence of infection in 48 of these patients, of whom 21 were shown to have Pseudomonas aeruginosa infections. Fourteen of these patients with pseudomonas infections had complete improvement, three improved temporarily but later died of infection, two had no improvement, and two could not be evaluated. This antibiotic combination was less promising for the infections caused by other gram-negative bacteria, especially klebsiella. Superinfection occurred in eight patients. Combination carbenicillin and gentamicin is of value as initial antibiotic therapy for suspected Ps. aeruginosa infection in granulocytopenic patients with cancer but only after careful examination and extensive culturing.

Bacterial proliferation in platelet products stored at room temperature. Transfusion-induced Enterobacter sepsis.

Abstract A theoretical objection to ambient-temperature platelet storage is the possibility of proliferation of micro-organisms introduced into the system during phlebotomy or component preparation. After gram-negative septicemia followed platelet infusion in two patients with cancer, a study was begun to determine the frequency of contamination in platelets stored at 25°C. Culture of 2188 U of platelets, pooled in groups of eight after storage, revealed bacteria in more than 20 per cent of pools; the minimal frequency of contamination in individual units was calculated to be 2.4 per cent. Bacteria including species of corynebacterium, staphylococcus, micrococcus, streptococcus, sarcina, bacillus, herellea, pseudomonas and flavobacterium were recovered; Enterobacter (Aerobacter) cloacae was isolated seven times and caused both septicemias. Twenty-five of 143 transfusions were later shown to have contained micro-organisms. The frequency of bacterial recovery progressively increased with increasing storage ...

Interaction in the germfree mouse intestine of colicinogenic and colicin-sensitive microorganisms.

Summary Synthesis of colicin, per se, by colicinogenic bacteria does not contribute significantly, if at all, toward a selective advantage in competition for dominance in gastrointestinal colonization. Per os inoculation of germfree mice with a slow lactose fermenting CA-62 colicinogenic bacteria and a colic-in-sensitive E. coli K-12 (Row) resulted in no suppression of the latter. When fecal samples were examined over a 4-week period, the colicin-sensitive E. coli actually outnumbered the colicin producer.

Levinea, a New Genus of the Family Enterobacteriaceae

A new genus of the family Enterobacteriaceae is proposed on the basis of its unique biochemical and serological properties. The genus, Levinea (named in honor of Max Levine), is composed of two different species, for which the names Levinea amalonatica and Levinea malonatica are proposed. L. amalonatica is designated as the type species. The type strain of L. amalonatica is 9823 (=ATCC 25405) and the type strain of L. malonatica is 1791 (=ATCC 25408). Information is given which distinguishes the proposed new genus from certain species of Enterobacter and Citrobacter, the genera which it most closely resembles. The similarity of L. amalonatica to organisms in the proposed new genus Padlewskia Macierewicz (9) is discussed.

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.

Effect of Two Cancer Chemotherapeutic Agents on the Antibacterial Activity of Three Antimicrobial Agents

Cancer chemotherapeutic agents and antibacterial antibiotics are often given concomitantly. Daunorubicin, cytosine arabinoside, and three antibiotics (gentamicin, amikacin, and ticarcillin) were tested individually and in combinations to determine their antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. These cytotoxic agents are commonly employed in the therapy of acute nonlymphocytic leukemia for remission induction therapy, and these antimicrobial agents are used in infection therapy. The maximum concentrations of the two cytotoxic drugs were chosen to be twice the known peak plasma levels of commonly employed dosage schedules. Neither of the cancer chemotherapeutic agents, alone or in combination, demonstrated bactericidal activity at the levels tested. However, in the presence of these agents, the antimicrobial activity of gentamicin and amikacin, although not that of ticarcillin, was depressed for 11 of 15 K. pneumoniae strains and 8 of 15 P. aeruginosa strains, but for none of the strains of E. coli. This level of decreased activity occasionally resulted in a minimal inhibitory concentration of the tested aminoglycoside well above the standard serum levels. Daunorubicin was more likely to antagonize gentamicin than was cytosine arabinoside.

Identification of Cryptococcus neoformans in a routine clinical laboratory

Eight taxonomic tests were compared for their ability to distinguishCryptococcus neoformans from the non-pathogenic species ofCryptococcus. Eight isolates ofCryptococcus were obtained from the American Type Culture Collection and 43 isolates were obtained directly from human and natural sources. The tests which appeared to be most valuable to the routine diagnostic laboratory were growth at 37° C, characteristic growth on Guizotia seed agar and virulence for mice.