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1.
The phagocytic and bactericidal activities to Salmonella pullorum (strain 9-25) or Salmonella senftenberg (strain 99D) were examined in chicken splenic phagocytes from 0-day-old to 2-month-old chickens. The phagocytic activity against S pullorum increased in splenic phagocytes from chickens older than 7 days, but significant changes in activity against S senftenberg were not observed during the experimental period. The bactericidal activity of splenic phagocytes against S senftenberg was higher than that of phagocytes against S pullorum during the same period. Increase of the bactericidal activity against S pullorum was observed with increasing age, but the activity of the splenic phagocytes from 0-day-old chickens against S senftenberg was similar to that of the phagocytes from 2-month-old chickens. Although delayed hypersensitivity was confirmed by delayed wattle reaction in 2-month-old chickens sensitized with living S pullorum, the sensitization did not markedly affect phagocytic and bactericidal activities.  相似文献   

2.
The macrolide antibiotics josamycin and rosamicin were compared in vitro with erythromycin for activity against Staphylococcus aureus, S. epidermidis, and enterococci and with clindamycin for activity against a variety of anaerobic organisms. Rosamicin and erythromycin were similar in activity and superior to josamycin against aerobic cocci. Most isolates of S. aureus (96%), S. epidermidis (79%), and the enterococci (87%) were inhibited by 1.56 mug of either of the new macrolide compounds per ml. Clindamycin was the most active compound against the anaerobic organisms.  相似文献   

3.
BACKGROUND: The soils of the southern part of Chile, that are isolated, cold, humid, poorly oxygenated and with a low acidity, could contain new strains of antimicrobial producing Streptomyces. AIM: To demonstrate that the soil of the Southern region of Chile contains Streptomyces strains with antimicrobial activity towards pathogenic bacteria and fungi. MATERIAL AND METHODS: Two hundred fifty eight soil and sediment samples were collected from 148 places in Southern regions of Chile. They were cultured in Küster-Williams growth media and the presence of Streptomyces was confirmed by microscopic examination and biochemical characterization. The antimicrobial activity against reference microorganisms of each wild strain was tested using the disk method. Among active Streptomyces strains, 38 with the higher activity were selected and tested against 142 clinical microorganisms. RESULTS: Seventy seven percent of soils were positive and 542 wild strains of Streptomyces were isolated; of these, 266 had antimicrobial activity. Fifty three percent of isolates had activity against S aureus 43% against B subtilis and 0.7% against E coli. Most Streptomyces were active against more than one organism. When there was activity against single organisms, these were mostly eucariotic, such as C albicans and T mentagrophytes. Among clinical microorganisms, 29% of S aureus strains were inhibited, while P aeruginosa, Alternaria sp, P vulgaris and Y enterocolitica strains were not inhibited. The most frequent Streptomyces morphotypes were those showing pigmented colonies with flexuous and spiral shaped chains of arthrospores. CONCLUSIONS: Soils of the Southern region of Chile allow the growth of abundant native strains of Streptomyces with a promising antimicrobial activity.  相似文献   

4.
The antimicrobial susceptibility of 492 anaerobic bacteria, the majority of which were recent clinical isolates, was determined by the agar dilution technique. Penicillin G was active against most of the strains tested at 32 U or less/ml, but only 72% of Bacteroides fragilis strains were susceptible at this level and 9% required 256 U or more/ml. Ampicillin was effective against most of the strains except B. fragilis at 16 mug or less/ml. Amoxicillin was active against only 31% of B. fragilis, 76% of other Bacteroides species, and 67% of Fusobacterium species at 8 mug/ml. Two new penicillins, mezlocillin and azlocillin, were similar to ampicillin in their activity. Carbenicillin and ticarcillin inhibited all but a few strains at 128 mug or less/ml. BLP 1654 was somewhat more active than penicillin G against B. fragilis but had similar activity against other anaerobes. Cephalothin was inactive against B. fragilis, and only 65% of other Bacteroides species were inhibited by 32 mug or less/ml. It was effective against all other anaerobes at that level. Cefamandole showed somewhat greater activity than cephalothin against B. fragilis but generally less activity against gram-positive organisms. Cefazaflur (SKF 59962) was comparable to cephalothin against B. fragilis. Cefoxitin was distinctly more active than cephalothin against B. fragilis. These latter two agents were less active than cephalothin against the gram-positive anaerobes. Chloramphenicol remains active against anaerobic bacteria at 16 mug or less/ml, with rare exceptions. Thiamphenicol was similar to chloramphenicol in its activity. Clindamycin was very active against most of the anaerobes at 8 mug or less/ml. Erythromycin and josamycin were also tested, with josamycin showing greater activity against B. fragilis than either erythromycin or clindamycin. A new oligosaccharide, everninomicin B, was less active than clindamycin against B. fragilis but more active against clostridia and some of the other strains tested. Most of the groups of bacteria tested demonstrated a trend toward resistance to tetracycline. Doxycycline and minocycline were somewhat more active than was tetracycline. Metronidazole was active against the majority of the anaerobes tested; resistance ws demonstrated by some of the gram-positive cocci and gram-positive, non-sporeforming bacilli.  相似文献   

5.
6.
The production of and sensitivity to bacteriocin-like activity among 44 strains of black-pigmented anaerobes isolated from periodontal sites were evaluated by both an overlay and an agar diffusion method. The species studied were Porphyromonas gingivalis, Prevotella intermedia and the closely related species Pr. nigrescens. Pr. intermedia strains (90%) produced bacteriocin-like activity against Pr. nigrescens and all Pr. nigrescens were active against Pr. intermedia. Both species showed a high degree of activity against P. gingivalis, whereas only one P. gingivalis strain produced bacteriocin-like activity against either of the other two species. Both Pr. nigrescens and Pr. intermedia showed some activity (40% and 20%, respectively) against other strains of the same species. Such bacteriocin production might be expected to influence the distribution of these black-pigmented species in vivo. Of 224 periodontal sites sampled, only 2.6% yielded mixed cultures of black-pigmented species and of these only one strain, a P. gingivalis isolate, produced bacteriocin-like activity against any of the other strains isolated from these sites. These data support the concept that local production of bacteriocin-like activity in vivo may contribute to the selection of the black-pigmented bacterial profile in subgingival sites.  相似文献   

7.
Purpuromycin and its semi-synthetic derivative MDL 63,604 had in-vitro activity similar to that of amphotericin B against isolates of Candida albicans. MDL 63,604 had activity similar to that of metronidazole against Trichomonas vaginalis. Both compounds were very active against most species of Gram-positive and Gram-negative anaerobes and against Gardnerella vaginalis. MDL 63,604 had significantly lower MICs than purpuromycin against T. vaginalis and most of the bacteria, probably due to antagonism of purpuromycin's activity by medium supplements (blood or serum). Purpuromycin or related compounds may have a potential role in the topical treatment of vaginitis and vaginosis.  相似文献   

8.
A series of 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazine-2-thiones was synthesized and evaluated for antibacterial and antifungal activity. All of the tested compounds were found active against Staphylococcus aureus and Staphylococcus epidermidis. The compounds were also active against yeast-like fungi and molds where the anticandidal activity of 3a against Candida albicans was superior to the standards miconazole and clotrimazole.  相似文献   

9.
A series of cis-restricted combretastatin analogues with 5-membered heterocycles were synthesized and their inhibitory activity against microtubule assembly and cytotoxic activity against the colon 26 adenocarcinoma cancer cell line were evaluated. Some of the heterocyclic analogues showed potent antitubulin activity and cytotoxicity. Compounds 16 and 35 showed marked tumor growth suppression in the colon 26 murine tumor model.  相似文献   

10.
Several extracts of Annona senegalensis (Annonaceae) seeds were tested for antiparasitic activity against Leishmania major, Leishmania donovani, Trypanosoma brucei brucei, and for cytotoxic activity against KB and VERO cell lines. Fractionation of seeds extracts was mainly guided by means of a biocidal assay against Artemia salina nauplii. The biological activities resulted from extract-isolated acetogenins.  相似文献   

11.
Sparfloxacin is a new antimicrobial that, while maintaining a good activity against gram negative bacilli, has a better in vitro activity against gram positive bacteria such as S pneumoniae, intracellular pathogens and anaerobic bacteria. The aim of this work was to study the in vitro activity of sparfloxacin against bacteria isolated from patients with community acquired respiratory infections between October 1994 and January 1995. Using the E-test technique, we studied the susceptibility to sparfloxacin, ciprofloxacin, ampicillin, amoxicillin/clavulanic acid, cefuroxime, cefotaxime, erythromycin, methicillin and nalidixic acid of 50 strains of S pneumoniae, 50 strains of H. influenzae, 50 strains of S aureus and 50 strains of S pyogenes. Sparfloxacin was active against 100% of S pneumoniae, H influenzae and S pyogenes strains. Twenty two percent of S aureus strains were resistant and the MIC 90 was 12 micrograms/ml. Sparfloxacin showed the best in vitro activity against H influenzae and S aureus, a similar activity with ampicillin and cefotaxime against S pneumoniae and a similar activity with ampicillin but superior to all other studied antimicrobial against S pyogenes. It is concluded that sparfloxacin is a good antimicrobial for bacteria isolated from patients with respiratory infections.  相似文献   

12.
Bacteria with inhibitory activity against Clostridium botulinum type C were isolated from 32% of sediment samples (n = 1600) collected from 10 marshes in a northern California wetland over a 12 mo period. Aerobic and anaerobic bacteria with inhibitory activity were isolated from 12% and 23% of the samples, respectively. Bacteria with inhibitory activity were isolated from all 10 study sites and throughout the year. This study demonstrates that bacteria with inhibitory activity against C. botulinum type C occur naturally in wetland sediments.  相似文献   

13.
Combinations of EDTA-Tris and two aminoglycoside antibiotics (amikacin and neomycin) were tested for synergistic activities against the microorganisms associated with otitis externa in dogs and for the solutions' stability over time. Synergistic activity was observed when EDTA-Tris plus amikacin and EDTA-Tris plus neomycin were tested against Staphylococcus intermedius, Proteus mirabilis, Pseudomonas aeruginosa, and Escherichia coli, but not against Candida albicans. Stability studies over a 3-month period indicated that the test solutions were stable at room temperature and that their antimicrobial activity was maintained.  相似文献   

14.
Based on the fact that Chenopodium amaranticolor extracts showed inhibitory activity against tobacco mosaic virus (TMV) and Ehrlich tumour (EA), tests were carried out to investigate whether the antiviral and antitumoral activity were caused by the same compounds. When the extract was purified by CM Sephadex C-25 column, after precipitation with 90% ammonium sulphate, twenty active fractions against TMV and two pools of fractions active against EA were obtained. Only one fraction with high absorbance values at 260 and 280 nm was able to inhibit both TMV and EA. When the extract was purified by Bio Gel P-60 column two active fractions against TMV and EA were obtained, suggesting that they were contained in the 0.01 M fraction of the CM Sephadex column. It is suggested that C. amaranticolor leaf extract contained at least two protein-like substances manifesting antiviral and antitumoral activity.  相似文献   

15.
Ten 4-[p-[bis(2-chloroethyl)amino]phenyl]butyrates were synthesized and evaluated for antitumor activity. The 2-phenoxyethyl ester exhibited activity against P-388 lymphocytic leukemia, and the n-butyl and n-pentyl esters exhibited activity against L-1210 lymphoid leukemia in initial screening tests.  相似文献   

16.
SAR for antimicrobial activity against H. pylori was investigated in a new series of 2-alkylguanidino-4-furylthiazoles. Of the compounds obtained, cyclohexylmethyl and ethoxyethyl derivatives were identified as a novel class of anti-H. pylori agents which possessed potent and selective antimicrobial activity against H. pylori. These compounds also showed gastric antisecretory activity.  相似文献   

17.
The activity of biapenem was compared with that of imipenem and cefotaxime against 108 strains of beta-lactamase producing Enterobacteriaceae. Biapenem and imipenem were very active, inhibiting 90% of the strains at a concentration of 0.5 microgram/ml. Both carbapenems were very active against plasmidic beta-lactamase producers, with MIC90s below 1 microgram/ml. However, the MIC90 of biapenem for cephalosporinase producers was 1 microgram/ml. Against strains producing extended-spectrum beta-lactamases, biapenem exhibited better activity against TEM-type producers (MIC90 0.25 microgram/ml) than against SHV-type producers (MIC90 0.5 microgram/ml). Overall, the in vitro antibacterial activity of biapenem is similar to that of imipenem.  相似文献   

18.
3-(Substituted)vinylcephem nuclei have been prepared by the reaction of 3-formylcephem derivatives with stabilized phosphoranes. Appropriate synthetic steps allowed preparation of a series of 3-ethoxycarbonylvinyl- and 3-carboxyvinylcephem derivatives bearing a variety of 7-acylamino functions. The phenoxyacetyl and thiopheneacetyl derivatives of the 3-cyanovinylcephem nucleus were also prepared. Although general gram-positive activity was comparable to cephalothin in many cases, against penicillin G resistant Staphylococcus aureus, the new cephalosporins were of low effectiveness. The 3-(substituted)vinyl cephalosporins had good activity against a number of gram-negative organisms. In some cases, this activity was excellent. The N-acetyl analogs had surprisingly good activity relative to N-acetyl-7-ACA. The phenylmalonoyl side-chain derivatives were shown to have an unusual antibacterial spectrum expansion (relative to previously known cephalosporins) to include activity against Serratia marcescens and Pseudomonas aeruginosa.  相似文献   

19.
Plant-derived acaricides, extracted from various botanical species, and commercially available phytochemicals were evaluated for biological activity against immature Ixodes scapularis (Say) using the disposable pipet method. In addition, residual activity of the plant extracts was determined. Of the 13 plant extracts tested, 9 exhibited biological activity with Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach., being the most effective against the nymphal ticks (LC50 = 0.151% wt:vol) and eastern red cedar, Juniperus virginiana L., showing the greatest activity against larval ticks (LC50 = .001% wt:vol). The commercially available products were significantly less active than the plant extracts we prepared, but some commercial compounds did exhibit limited activity. Only the Alaska yellow cedar exhibited any residual activity that lasted 21 d after treatment.  相似文献   

20.
Alternate mutations in the grlA and gyrA genes were observed through the first- to fourth-step mutants which were obtained from four Staphylococcus aureus strains by sequential selection with several fluoroquinolones. The increases in the MICs of gatifloxacin accompanying those mutational steps suggest that primary targets of gatifloxacin in the wild type and the first-, second-, and third-step mutants are wild-type topoisomerase IV (topo IV), wild-type DNA gyrase, singly mutated topo IV, and singly mutated DNA gyrase, respectively. Gatifloxacin had activity equal to that of tosufloxacin and activity more potent than those of norfloxacin, ofloxacin, ciprofloxacin, and sparfloxacin against the second-step mutants (grlA gyrA; gatifloxacin MIC range, 1.56 to 3.13 microg/ml) and had the most potent activity against the third-step mutants (grlA gyrA grlA; gatifloxacin MIC range, 1.56 to 6.25 microg/ml), suggesting that gatifloxacin possesses the most potent inhibitory activity against singly mutated topo IV and singly mutated DNA gyrase among the quinolones tested. Moreover, gatifloxacin selected resistant mutants from wild-type and the second-step mutants at a low frequency. Gatifloxacin possessed potent activity (MIC, 0.39 microg/ml) against the NorA-overproducing strain S. aureus NY12, the norA transformant, which was slightly lower than that against the parent strain SA113. The increases in the MICs of the quinolones tested against NY12 were negatively correlated with the hydrophobicity of the quinolones (correlation coefficient, -0.93; P < 0.01). Therefore, this slight decrease in the activity of gatifloxacin is attributable to its high hydrophobicity. Those properties of gatifloxacin likely explain its good activity against quinolone-resistant clinical isolates of S. aureus harboring the grlA, gyrA, and/or norA mutations.  相似文献   

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