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PubMedDate not supplied

In vitro susceptibility of fungal isolates of clinically important specimens to itraconazole, fluconazole and amphotericin B.

The in vitro activity of itraconazole, fluconazole and amphotericin B was tested against 207 yeast strains and 3 Aspergillus fumigatus strains isolated from blood. The other 42 A. fumigatus strains were selected from respiratory tract infections. A microdilution method was employed to determine the inhibitory concentrations to restrain 70% of isolate growth (IC30). The inhibition concentrations of amphotericin B are all around the value 0.25 mg/l with a deviation of two concentration degrees, indicating sensitivity of all strains. The test results of itraconazole showed the majority of strains in the range of sensitivity (200 isolates) and low sensitivity (44 isolates). Five of 19 Candida glabrata strains demonstrated resistance to itraconazole. The results of fluconazole showed a good sensibility of C. albicans, but 4.5% of strains were resistant. Low sensitivity (1 strain) and resistance (24 strains) were evaluated for C. glabrata and C. krusei isolates. No strain of A. fumigatus was inhibited by fluconazole. The data show the necessity of in vitro tests.

Amphotericin B↗
PubMed1975

Experimental infection of rabbits with Bacillus cereus.

Bacillus cereus was able to grow and produced local infections following subcutaneous or intramuscular injection. An inflammatory response was produced with necrosis of muscle fibres and calcification. The organism was sensitive to chemotherapeutic agents on in vitro tests.

Abscess↗
PubMed1986

Antibacterial hemolymph proteins of Manduca sexta.

Exclusion column fractionated immune hemolymph of the M. sexta larva contains five peaks of anti-E. coli activity with molecular weights of greater than 140 kD and approximately 91, 54, 14 and 4 kD, plus one peak of lysozyme activity with a molecular weight of 17 kD. Purification of the 54 kD peak showed that this peak consists of the previously described M18 proteins which have monomeric weights of approximately 20 kD and had antibacterial activity against certain gram negative bacteria. Approximately 80% of the total hemolymph antibacterial activity was detected in the 14 and 4 kD peaks. These proteins, which kill both gram negative and gram positive bacteria, appeared to be directly analogous to the cecropins of H. cecropia. The greater than 140 and 91 kD peaks constituted only a minor part of the total antibacterial activity.

Animals↗
PubMed2004

Comparative in vitro activity of antiribosomal agents on penicillin-susceptible and -resistant Streptococcus pneumoniae in relation to their resistance genotypes.

A collection of 326 strains of Streptococcus pneumoniae isolated from blood, cerebrospinal fluid, bronchoalveolar lavage, transtracheal aspirate or sputum from January 1996-June 2002 were included in this study. The activity of clarithromycin, clindamycin, telithromycin, linezolid and quinupristin/dalfopristin against penicillin G and erythromycin A susceptible and resistant pneumococci were determined; the erythromycin A resistance phenotypes and genotypes were identified and susceptibilities of these agents were assessed according to the resistance genotypes. MICs were determined for all strains of pneumococci using an agar dilution method. MLS(B) resistance phenotypes were determined by the double disk (erythromycin A and clindamycin) diffusion method. Genetic determinants for macrolide resistance were identified by PCR using primers specific for erm(B) and mef(A). Erythromycin A resistance was detected in 13.8% of the strains. MLS(B) resistance phenotype was observed in 82% of these (60% being cMLS(B) and 40% being iMLS(B)), and M type resistance in about 18%. All the MLS(B) phenotype strains except four, revealed the presence of erm(B) gene and all except one M phenotype strains revealed the mef(A) gene. Of the erythromycin A resistant pneumococci about 49% were also resistant to clindamycin. No strains were resistant to telithromycin, quinupristin/dalfopristin and linezolid. Telithromycin had the lowest MIC values for both erythromycin A resistant and susceptible strains of all the antiribosomal agents tested. The most prevalent mechanism of macrolide resistance was mediated by the erm(B) gene leading to the expression of MLS(B) phenotype. Telithromycin was the most active antiribosomal agent, regardless of the macrolide resistance genotype of the pneumococci tested.

Drug Resistance, Microbial↗
PubMed1975

Ampicillin-resistant Haemophilus influenzae type B possessing a TEM-type beta-lactamase but little permeability barrier to ampicillin.

Ampicillin-resistant Haemophilus influenzae type B have been reported only during the past year. Five clinical isolates from the U.S. and Germany all had the TEM-type beta-lactamase which is known to be transferred widely among other gram-negative bacilli. Unlike those bacilli, however, the H. influenzae cell had very little barrier to entry of penicillins. This greater permeability of the H. influenzae cell to penicillins appeared to reduce the protective effect of its beta-lactamase, in that acquisition of the TEM-type beta-lactamase increased levels of resistance to penicillins much less for individual cells of H. influenzae than for those of Escherichia coli. Large inocula of either species appeared highly resistant. The unusually low level of resistance of individual cells of H. influenzae containing the TEM-type beta-lactamase may have delayed their emergence or recognition, and has unresolved clinical implications.

Amidohydrolases↗
PubMed1999

Horseshoe crab acetyl group-recognizing lectins involved in innate immunity are structurally related to fibrinogen.

We have characterized and cloned newly isolated lectins from hemolymph plasma of the horseshoe crab Tachypleus tridentatus, which we named tachylectins 5A and 5B (TLs-5). TLs-5 agglutinated all types of human erythrocytes and Gram-positive and Gram-negative bacteria. TLs-5 specifically recognize acetyl group-containing substances including noncarbohydrates; the acetyl group is required and is sufficient for recognition. TLs-5 enhanced the antimicrobial activity of a horseshoe crab-derived big defensin. cDNA sequences of TLs-5 indicated that they consist of a short N-terminal Cys-containing segment and a C-terminal fibrinogen-like domain with the highest sequence identity (51%) to that of mammalian ficolins. TLs-5, however, lack the collagenous domain found in a kind of "bouquet arrangement" of ficolins and collectins. Electron microscopy revealed that TLs-5 form two- to four-bladed propeller structures. The horseshoe crab is equipped with a unique functional homologue of vertebrate fibrinogen, coagulogen, as the target protein of the clotting cascade. Our observations clearly show that the horseshoe crab has fibrinogen-related molecules in hemolymph plasma and that they function as nonself-recognizing lectins. An ancestor of fibrinogen may have functioned as a nonself-recognizing protein.

ABO Blood-Group System↗
PubMed1999

Lectin typing of methicillin-resistant Staphylococcus aureus.

This study reports the patterns of agglutination of 77 clinical isolates of methicillin-resistant Staphylococcus aureus by 32 commercially available lectins. Cell suspensions were not pre-treated. Each isolate was cultured on three media: Columbia blood agar, trypticase-soy agar and Chapman Stone agar. The lectins agglutinating each isolate varied widely depending on culture medium; only five isolates were agglutinated by the same set of lectins regardless of the culture medium used. Lectin typing could be a useful epidemiological tool, but it is necessary to standardise assay conditions (notably culture medium) to enable meaningful comparison of the results produced by different research groups or centres.

Agglutination Tests↗
PubMed1999

Identification of Haemophilus influenzae Rd transformation genes using cassette mutagenesis.

Genes required for natural transformation of Haemophilus influenzae Rd were identified by a cassette mutagenesis protocol consisting of the following steps: random insertional mutagenesis, phenotypic screening, sequencing of genome sequence tags from the DNA flanking the insertion in the selected mutants and comparison of genome sequence tags to genomic sequence data. The cassette mutagenesis screen for transformation genes resulted in five distinct mutant classes, two of which have been identified in previous studies. Insertions in the three newly identified loci interrupted genes with predicted protein products homologous to a type IV pilin-like protein biogenesis operon, drug-efflux transporters and a phospholipid-biosynthesis enzyme. The most significant finding of this screen is the requirement for type IV pilin-like proteins in genetic transformation of H. influenzae. These surface structures are utilized for DNA uptake in a number of Gram-positive and Gram-negative bacteria, and appear to be the common component among the systems for DNA binding.

Anti-Bacterial Agents↗
PubMed1965

DRUG ANTAGONISM BETWEEN LINCOMYCIN AND ERYTHROMYCIN.

An antagonistic action can be demonstrated between lincomycin, a new antibiotic, and erythromycin, when the two drugs are allowed to diffuse into the same area of an agar plate seeded with a strain of Staphylococcus which is resistant to erythromycin but sensitive to lincomycin. The increase in the minimum inhibitory concentrations of lincomycin in the presence of erythromycin may be significant in clinical application. The antagonism does not depend on a reaction between the two antibiotics, but appears to be the result of an altered metabolism stimulated by erythromycin on erythromycin-resistant staphylococci.

Anti-Bacterial Agents↗
PubMed1984

Single-dose amoxicillin therapy of acute uncomplicated urinary tract infections in women.

Of 210 women who were experiencing dysuria, frequent urination, pyuria, and significant bacteriuria and who were treated with a single 3-g dose of amoxicillin, 165 (79%) were cured of their original infections. Patients with infections that were negative by antibody-coated-bacteria assay were cured at a significantly higher rate than those with infections that were positive by antibody-coated-bacteria assay (90 versus 59%; P less than 0.001). Similarly, those with infections caused by amoxicillin-susceptible organisms were cured at a significantly higher rate than those with infections caused by resistant organisms (85 versus 50%; P less than 0.001). Of 27 patients who had infections caused by amoxicillin-susceptible organisms and who had relapses after single-dose therapy, 14 (52%) had relapses again after a conventional 10-day course of therapy, although all responded to a 6-week course. An additional 27 patients experiencing dysuria, frequent urination, and pyuria but who had a lower number of uropathogens in the urine (10(2) to 10(4.5)/ml of urine) were treated with single-dose therapy, with a 100% eradication of organisms and an 89% rate of symptomatic relief.

Acute Disease↗
PubMed2001

Characterization of emeA, a NorA homolog and multidrug resistance efflux pump, in Enterococcus faecalis.

We hypothesized that multidrug resistance efflux pumps (MDRs) may be contributing to the drug resistance of enterococci. We recently identified potential MDR-encoding genes in the Enterococcus faecalis V583 genome. Among the putative MDRs, we found a gene that encodes a NorA homolog and have characterized this enterococcal MDR in the present study. A mutant from which the enterococcal NorA homolog has been deleted has reduced resistance to several NorA substrates. Complementation of the deletion mutant with the wild-type gene verified the involvement of this enterococcal gene in resistance to ethidium bromide (EtBr) and norfloxacin. Known MDR inhibitors (reserpine, lansoprazole, and verapamil) inhibit the efflux of EtBr and norfloxacin in wild-type strain OG1RF. A fluorescence assay with EtBr allowed us to quantitate the efflux capability of the enterococcal NorA pump. On the basis of these results, we have named this enterococcal gene emeA (enterococcal multidrug resistance efflux).

Amino Acid Sequence↗