Experimental Escherichia coli endocarditis in rats: roles of serum bactericidal activity and duration of catheter placement.

Studies were undertaken to investigate the relationship of the sensitivity of Escherichia coli to the bactericidal properties of serum and the ability of different strains to induce and sustain endocardial infection in rats. Strains of E. coli demonstrated different degrees of serum sensitivity, as determined by a method which employed concentrations of serum from 10 to 95% and periods of incubation as long as 24 h.

Association of hydroxamate siderophore (aerobactin) with Escherichia coli isolated from patients with bacteremia.

Clinical isolates of Escherichia coli were examined for the presence of hydroxamate siderophore (aerobactin). The incidence of aerobactin-positive strains of E. coli from the blood was greater than the incidence of these strains isolated from other sites.

Experimental pyelonephritis. The effect of T-cell deficiency on the course of hematogenous enterococcal pyelonephritis in the mouse.

The course of experimental hematogenous pyelonephritis due to Streptococcus faecalis was compared in athymic (nu/nu) mice and euthymic (nu/+) littermates. Up to 7 weeks following infection, there were no significant differences in renal microbial populations. At 63 and 107-131 days there was significant escalation of infection in nu/nu mice, while the nu/+ mice were decreasing their infections.

Treatment of staphylococcal pyelonephritis in rats with N-formimidoyl thienamycin.

The therapeutic efficacy of N-formimidoyl thienamycin alone or coadministered with MK0791, an inhibitor of renal dehydropeptidase-I, compared to methicillin in experimental pyelonephritis in rats was investigated. Pyelonephritis was produced with a methicillin-sensitive strain (2776) and a methicillin-resistant strain (Berman) of Staphylococcus aureus. N-formimidoyl thienamycin alone or coadministered with the inhibitor was significantly better than methicillin when treating methicillin-sensitive or methicillin-resistant infection.

Antibiotic prophylaxis against streptomycin-resistant and -susceptible Streptococcus faecalis endocarditis in rabbits.

This report describes the capacities of ampicillin, vancomycin, streptomycin, gentamicin, and combinations thereof to prevent endocarditis in rabbits challenged with either streptomycin-resistant (three strains) or streptomycin-susceptible (one strain) Streptococcus faecalis. Vancomycin (15 mg/kg) alone was effective in preventing infection with three of four strains, including two which were streptomycin resistant. Vancomycin (30 mg/kg) alone was effective against the other streptomycin-resistant strain.

Therapy of experimental Pseudomonas endocarditis with high-dose amikacin and ticarcillin.

Right-sided infective endocarditis due to Pseudomonas aeruginosa was induced in 130 rabbits. Animals received either: (1) no therapy (controls); (2) standard-dose amikacin (AMK) (15 mg/kg/day) plus ticarcillin (300 mg/kg/day), or (3) high-dose AMK (20 or 25 mg/kg/day) plus ticarcillin, for 20 days. Animals in each treatment group were evaluated at 10 days after therapy for bacteriologic relapse.

Lack of significance of pili in experimental ascending Escherichia coli pyelonephritis.

The role of pili as a bacterial virulence factor has been studied. The model used was acute ascending Escherichia coli pyelonephritis in the mouse. Three strains of E.

Effect of iron on acute pyelonephritis and later chronic changes.

Administration of iron to rats exacerbated early inflammatory changes of pyelonephritis produced by intravenous inoculation of Escherichia coli. This effect was noted with four of eight strains of E. coli tested and was dependent on bacterial inoculum.

Variables in demonstrating methicillin tolerance in Staphylococcus aureus strains.

Certain technical considerations which affected the status of methicillin tolerance in Staphylococcus aureus strains were studied. Methods which consistently demonstrated tolerance or intolerance of a given strain were avoidance of inoculum splashing, use of stationary-phase inoculum, 24-h tube incubation, and minimization of antibiotic carry-over. These studies suggested a need for the establishment of a standardized reference for the determination of tolerance.

Comparative ocular pathogenicity of Cryptococcus neoformans, Candida glabrata, and Aspergillus fumigatus in the rabbit.

In a previous study, 88% of rabbits with disseminated infection caused by Candida albicans developed ophthalmoscopically visible, hematogenous endophthalmitis (chorioretinitis) over a 2 week period. To determine the incidence of this ocular complication in disseminated infection caused by Cryptococcus neoformans, Candida glabrata, and Aspergillus fumigatus compared with that caused by C. albicans, the first three species of fungi were injected intravenously (between 10(5) and 10(9) organisms per animal) into 36 New Zealand white rabbits.

The role of antibiotic tolerance in the response to treatment of pyelonephritis due to Staphylococcus aureus in rats.

The effect of tolerance to methicillin on the response to treatment of hematogenous pyelonephritis due to Staphylococcus aureus was evaluated in rats. Tolerance was defined as a ratio of minimal bactericidal concentration to minimal inhibitory concentration of greater than or equal to 32. Rats that were infected with tolerant or nontolerant stains of S.

Rifampin, ampicillin, streptomycin, and their combinations in the treatment of enterococcal pyelonephritis in rats.

The activities of ampicillin, rifampin, streptomycin, and their combinations were evaluated in vitro against Streptococcus faecalis strain GK and in vivo in rats with an established pyelonephritis resulting from challenge with this same enterococcus. In vitro synergy was demonstrated between all combinations. Comparison of the log colony-forming units of S.

Cryptococcal intracerebral mass lesions: the role of computed tomography and nonsurgical management.

Cephalic computed tomography (CT) is a sensitive technique for defining certain intracerebral diseases. Four patients with cryptococcosis were evaluated with cephalic computed tomography over 3 years. All had focal, intracerebral "contrast-enhanced" lesions consistent with cryptococcal mass lesions, confirmed histopathologically in two.

Experimental intraabdominal candidiasis in rabbits: therapy with low-total-dose intravenous amphotericin B.

By using a recently developed rabbit model, we examined the efficacy of relatively low-total-dose intravenous amphotericin B (Am-B; 7 to 14 mg/kg) in the treatment of intraabdominal candidiasis due to Candida albicans. Forty-eight percent of the rabbits developed evidence of hematogenously disseminated infection (Candida endophthalmitis) before therapy. By day 7 of therapy, there was a significant decrease in the mean log10 colony-forming units per gram of peritoneal abscess in comparison with both pretherapy cultures and concomitantly sacrificed controls (no Am-B treatment; P less than 0.

Properties of binding of Escherichia coli endotoxin to various matrices.

Binding of Escherichia coli O127:B8 endotoxin to a variety of resins and column materials was investigated by measuring the beta-hydroxy myristic acid content (a major component of the lipid A moiety) of endotoxin after hydrolysis by selected ion-monitoring gas chromatography-mass spectrometry. More than 80% of the endotoxin was bound to hydroxylapatite, polystyrene, Dowex 1-X2, and charcoal. The binding of endotoxin to these materials was markedly reduced by the addition of normal or delipidated serum.

Therapy of experimental infective endocarditis due to antibiotic-tolerant Lactobacillus plantarum-bactericidal synergy of penicillin plus gentamicin. Correlation of in vitro susceptibility studies with in vivo efficacy.

Infective aortic valve endocarditis (IE) was induced in 40 rabbits with a penicillin (PNC)-tolerant, gentamicin (GM)-resistant strain of Lactobacillus plantarum; this isolate was synergistically killed in vitro by PNC + GM. The in vivo relevance of the in vitro observations was examined by determining the rates of eradication of endocardial L. plantarum by PNC versus PNC + GM.

Neurological disease associated with Mycoplasma pneumoniae pneumonitis: demonstration of viable Mycoplasma pneumoniae in cerebrospinal fluid and blood by radioisotopic and immunofluorescent tissue culture techniques.

Several neurologic syndromes (including Guillain-Barré) complicated Mycoplasma pneumoniae pneumonitis in a young man. At onset of neurologic disease, buffy coat and cerebrospinal fluid cultures on inert media were negative for M. pneumoniae.

Oxacillin nephritis.

Acute interstitial nephritis secondary to administration of antibiotics is a well-described entity. Oxacillin, however, has never been directly implicated. An 80-year-old man had a rising creatinine level and eosinophiluria while receiving oxacillin sodium.

Clinical value of teichoic acid antibody titers in the diagnosis and management of the staphylococcemias.

Differentiation of endocarditic from nonendocarditic Staphylococcus aureus (SA) septicemia is prognostically and therapeutically important. A study of 68 cases of either SA or streptococcal sepsis, including 50 cases of SA sepsis of both cardiac and noncardiac origin, was done to determine the presence and titer of serum teichoic acid antibodies (TAA's) by double immunodiffusion. Thirty-seven uninfected controls were also examined.