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1.
One hundred consecutive isolates of N. gonorrhoeae were tested for susceptibility to penicillin, ampicillin, tetracycline, erythromycin, kanamycin, cephaloridine and cephalexin by an agar dilution method. Relative resistance to penicillin was frequent. For 39% of isolates the minimum inhibitory concentration (MIC) of penicillin was 0.05 U./ml. or less; in 55% the MIC was 0.5 to 2.0 U./ml. Ampicillin was slightly more active than penicillin G: all isolates were inhibited by 0.5μg./ml. or less. Resistance to tetracycline and erythromycin was frequent with MIC of 1 μg./ml. or greater observed in 32 and 24% of isolates respectively. The MIC of kanamycin for all gonococci was 8 μg./ml. or greater. Cephalexin was slightly more active than cephaloridine, though each drug exhibited a wide range of MIC values. Gonococcus isolates resistant to penicillin (MIC of 1.0 U./ml. or greater) tended to be resistant to the other antibiotics tested. 相似文献
2.
Chemotherapeutic sensitivity and viability of Nocardia asteroides and Nocardia brasiliensis in drugs
Procedures for testing drug sensitivity ofNocardia were standardized.Five strains each ofN. asteroides (NA) andN. brasiliensis (NB) isolated from pathogenic materials were tested for drug sensitivity in Sabouraud's glucose agar (SGA), Sabouraud's glucose broth (SGB) and SGB with addition of 10 % horse serum against sulphadiazine (S), penicillin (P), streptomycin (St), chloramphenicol (C), tetracycline (T) and 4-4-diamino diphenyl sulphone (DDS). The viability of strains at minimum inhibitory concentrations (MIC) of different drugs were also tested.Results showed that liquid medium is preferable to solid medium for drug testing as pellicle formation observed on the surface of liquid medium helps in accurate assessment of MIC. Serum addition did not appear to be necessary. Ten days incubation at 37 °C gives optimum results for determination of MIC. Taking the maximum drug concentration attainable in blood during therapy, the strains were classified as sensitive and resistant. All strains were resistant to DDS and P. One strain of NB was sensitive to St. One strain each of NA and NB was borderline sensitive to C. Four out of 5 strains in both species were sensitive to S. All strains were sensitive to T. The organisms remained viable in drugs, thus suggesting the limitations of antinocardial therapy.From Mycology Research Unit, Department of Dermatology, Seth G.S. Medical College and K.E.M. Hospital, Bombay-12.Hon. Professor Dermato-Venereology.Research Fellow. 相似文献
3.
Jones SE Burgos JM Lutnesky MM Sena JA Kumar S Jones LM Varela MF 《Current microbiology》2011,62(4):1139-1146
Antimicrobial agent usage is common in animal agriculture for therapeutic and prophylactic purposes. Selective pressure exerted
by these antimicrobials on soil bacteria could result in the selection of strains that are resistant due to chromosomal- or
plasmid-derived genetic components. Multiple antimicrobial resistances in Escherichia coli and the direct relationship between antimicrobial agent use over time has been extensively studied, yet the relationship
between the age of an animal agriculture environment such as a dairy farm and antibiotic resistance remains unclear. Therefore,
we tested the hypothesis that antimicrobial-resistance profiles of E. coli isolated from dairy farm topsoil correlate with dairy farm age. E. coli isolated from eleven dairy farms of varying ages within Roosevelt County, NM were used for MIC determinations to chloramphenicol,
nalidixic acid, penicillin, tetracycline, ampicillin, amoxicillin/clavulanic acid, gentamicin, trimethoprim/sulfamethoxazole,
cefotaxime, and ciprofloxacin. The minimum inhibitory concentration values of four antibiotics ranged 0.75 to >256 μg/ml,
1 to >256 μg/ml, 12 to >256 μg/ml, and 0.75 to >256 μg/ml for chloramphenicol, nalidixic acid, penicillin, and tetracycline,
respectively. The study did not show a direct relationship between antibiotic resistance and the age of dairy farms. 相似文献
4.
Combined parenteral and intramammary treatment of mastitis caused by Staphylococcus aureus was compared to parenteral treatment only. Cows with clinical mastitis (166 mastitic quarters) caused by S. aureus treated by veterinarians of the Ambulatory Clinic of the Faculty of Veterinary Medicine during routine farm calls were included.
Treatment was based on in vitro susceptibility testing of the bacterial isolate. Procaine penicillin G (86 cases due to β -lactamase negative strains) or amoxycillin-clavulanic acid (24 cases due to β -lactamase positive strains) was administered parenterally and intramammarily for 5 days. Efficacy of treatments was assessed
2 and 4 weeks later by physical examination, bacteriological culture, determination of CMT, somatic cell count and NAGase
activity in milk. Quarters with growth of S. aureus in at least one post-treatment sample were classified as non-cured. As controls we used 41 clinical mastitis cases caused
by penicillin-susceptible S. aureus isolates treated with procaine penicillin G parenterally for 5 days and 15 cases due to penicillin-resistant isolates treated
with spiramycin parenterally for 5 days from the same practice area. Bacteriological cure rate after the combination treatment
was 75.6% for quarters infected with penicillin-susceptible S. aureus isolates, and 29.2% for quarters infected with penicillin-resistant isolates. Cure rate for quarters treated only parenterally
with procaine penicillin G was 56.1% and that for quarters treated with spiramycin 33.3%. The difference in cure rates between
mastitis due to penicillin-susceptible and penicillin-resistant S. aureus was highly significant. Combined treatment was superior over systemic treatment only in the β -lactamase negative group. 相似文献
5.
H Hejzlar M Drazdáková B Podaná J Kvicera E Kittnar L Hajková A Povolná V Sedmidubsky J Nedvídková E Janatová T Pellar L Stastná 《Journal of hygiene, epidemiology, microbiology, and immunology》1982,26(4):385-395
Over the past 25 years a total of 7492 strains of Neisseria gonorrhoeae have been isolated in Czechoslovakia, mainly in Prague (64%). All these strains have been tested for susceptibility to the following antibiotics: penicillin G, ampicillin, tetracycline, spectinomycin, erythromycin, doxycycline, kanamycin, rifampin, chloramphenicol, gentamicin, cephalothin, cephaloridine, lincomycin and clindamycin. In addition, seven derivatives of newer antibiotics of penicillin and cephalosporin series were tested in 1981. The study showed that in 1957 the MIC of 0.03 units of penicillin per ml was effective against 95% of strains, but in 1981 only 37% of isolates were sensitive to this concentration. The first gonococcal strains with the MIC value of 4.0 units/ml to penicillin were detected in 1981. This tendency towards decreased gonococcal susceptibility to benzylpenicillin is alarming. Over the last eight years there have been described sporadic isolations of strains relatively resistant to tetracycline (MIC = 8.0 mg/l). The susceptibility to spectinomycin has been tested in over 4000 gonococcal strains, since 1967. The test showed that this antibiotic remained highly effective against the gonococcal infection with over 95% of gonococci with the MIC value of 16.0 mg/l. No fully spectinomycin resistant strains have been found. Penicillin G as well as spectinomycin and cefotaxim are still considered the antibiotics of the first choice in the treatment of gonorrhoea. The alternative antibiotics may include cefuroxim, chloramphenicol and, in cases of sensitive strains, tetracyclines. 相似文献
6.
The in-vitro biological activity of N-benzylsalicylthioamides against 8 bacterial strains was determined by broth microdilution method; results were compared with
those obtained with neomycin, penicillin G, ciprofloxacin and penicillin V. The compounds showed moderate to high activity
against G+ bacteria; especially compounds 4, 6, 13, 16–21 and 24 exhibited comparable or higher activity than reference drugs. The antibacterial activity was analyzed by quantitative structure-activity
relationship (QSAR). The antibacterial activity increased with lipophilicity, with the presence of halogens and with increasing
value of Hammet substituent constant σ. 相似文献
7.
Antimicrobial susceptibility of 25 Helicobacter pylori strains isolated from patients with acid peptic diseases were tested for in vitro sensitivity to commonly used antibiotics using disk-diffusion and E-test, methods. All strains tested were susceptible to
tetracycline by E-test, with the minimum inhibitory concentration (MIC) values being <0.125 μg/ml for all strains except for
6 (<0.023 μg/ml). However 1 strain was resistant by disk-diffusion method. One strain was resistant to clarithromycin both
by disk diffusion and E-test (MIC <48 μg/ml), and 1 strain was resistant only by disk diffusion. Only one strain was resistant
to amoxicillin by disk diffusion and E-test (MIC >256 μg/ml). For ciprofloxacin, three strains were resistant by disk diffusion
and two by E-test (MIC <32 μg/ml). Sixteen strains were resistant to metronidazole by disk diffusion and E-test (MIC ≥ 8 μg/ml),
and 1 was resistant only by E-test (MIC <48 μg/ml). Overall, 64% of the strains were resistant to metronidazole. The MIC for
metronidazole was also tested by agar-dilution method, and metronidazole resistant strains had an, MIC >8 μg/ml. The disk-diffusion
method showed excellent correlation with E-test results; there was 100% agreement for amoxicillin a other antibiotics showed
90% to 95% accuracy. Disk diffusion is cheaper than E-test (approximately 2.6 cents vs. US$2.60), is easy to perform, and
is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory. 相似文献
8.
A selective agar medium containing cycloserine (250 mg/L), sulfamethoxazole (76 mg/L), and trimethoprim (4 mg/L) was used
for isolation ofClostridium bifermentans from the intestinal contents of California desert tortoise. Typical lecithinase positive colonies that appeared on the plates,
were biochemically characterized with the API 20A System and a conventional procedure. The susceptibility of the isolates
to 12 antimicrobial agents was determined by the broth microtitration technique using the ANA MIC System.C. bifermentans strains were shown to be highly susceptible to cefoxitin, cefotetan, ceftizoxime, cefotaxime, chloramphenicol, clindamycin,
penicillin, metronidazole, piperacillin, ticarcillin, and mezlocillin. Less than 10% of the isolates exhibited resistance
to tetracycline. All strains were found to be highly resistant to cycloserine, sulfamethoxazole, and trimethoprim. The GLC
analysis of the culture supernatants for volatile fatty acids revealed the presence of formic, acetic, isobutyric, butyric,
isovaleric, and isocaproic acids. 相似文献
9.
Tatjana Mihajilov-Krstev Dragan Radnović Dušanka Kitić Bojan Zlatković Mihailo Ristić Suzana Branković 《Central European Journal of Biology》2009,4(3):411-416
Essential oil of Satureja hortensis L. was analyzed by GC and GC/MS and tested by a broth micro-well dilution method for activity against multiresistant clinical
isolates of pathogenic bacteria from 10 different genera: Klebsiella, Escherichia, Proteus, Staphylococcus, Streptococcus, Pseudomonas, Enterococcus, Enterobacter, Citrobacter and Acinetobacter. The main compounds in the oil were carvacrol (67%), γ-terpinene (15.3%) and p-cymene (6.73%). The oil showed activity against
all tested strains. MIC/MBC values were in the range of 0.78-25 μl/ml, with the exception of the strain P. aeruginosa. Microbicidal
concentration for this particular strain (50 μl/ml) was the highest tested concentration. The oil showed inhibitory and bactericidal
effect at the same concentration (MIC=MBC) for all but three strains. 相似文献
10.
Resistance to Antimicrobial Agents in Lactobacilli Isolated from Caper Fermentations 总被引:1,自引:0,他引:1
Pérez Pulido R Omar NB Lucas R Abriouel H Martínez Cañamero M Gálvez A 《Antonie van Leeuwenhoek》2005,88(3-4):277-281
A collection of lactobacilli comprising species of Lactobacillus plantarum (43 isolates), Lactobacillus brevis (9 isolates) and Lactobacillus fermentum (6 isolates) obtained from spontaneous fermentations of capers (the fruits of Capparis spinosa) were investigated for resistance to antimicrobial agents. All isolates were resistant to vancomycin and teicoplanin (MIC
> 16 μg/ml). Resistance to ciprofloxacin (MIC > 2 μg/ml) was detected in all isolates of L. brevis and L. fermentum as well as in most isolates of L. plantarum, whilst resistance to levofloxacin showed a much lower incidence. Among L. plantarum and L. brevis isolates, low levels of resistance to tetracycline and/or nitrofurantoin were detected. Higher resistance levels were also
detected in some isolates. Resistance to penicillin and rifampicin were also detected among L. plantarum isolates. All isolates were sensitive to ampicillin, erythromycin, chloramphenicol, gentamicin, streptomycin, and quinupristin/dalfopristin. 相似文献
11.
A simple method was developed to release periplasmic penicillin G acylase from Escherichia coli BL21(DE3) during the fermentation process. More than 80% of the total penicillin G acylase was released into the broth when
3% (v/v) chloroform was added at 3 h after induction. The activity of extracellular penicillin G acylase reached 20699 U/l.
This method was efficient and would facilitate further investigation of penicillin G acylase for industrial applications. 相似文献
12.
Uterine microbiology and antimicrobial susceptibility was investigated in 239 mares with fertility problems in a prospective study in Sweden. Uterine swab samples were collected with double guarded swabs and transported overnight before being cultured. The Minimum Inhibitory Concentrations (MIC) was determined for a panel of antimicrobials. From 152 of the 239 mares at least one bacterial species was isolated, most frequently E. coli (104 isolates), β -haemolytic streptococci (31) and fungi (16). β -haemolytic streptococci were more frequently (p < 0.01) associated with clinical endometritis than with repeat breeding. The opposite was true for E. coli (p < 0.01). Among β -haemolytic streptococcal isolates some resistance was noted for 4 of 11 tested antibiotics, however, all isolates were susceptible to the widely used penicillin G. Among E. coli isolates enrofloxacin was the only of the 10 tested antibiotics for which no resistance was noted. Resistance was most commonly noted to cephalothin (39% of the isolates), streptomycin (22%), trimethoprim/sulphamethoxazole (15%) and ampicillin (11%). In conclusion, we show that both E. coli and β -haemolytic streptococci are frequently associated with fertility problems in mares and that antimicrobial resistance is a common feature of E. coli but also recognised for β -haemolytic streptococcal uterine isolates. 相似文献
13.
Ghada Choho Hikmate Abriouel Nabil Ben Omar Rosario Lucas López Elena Ortega Magdalena Martínez-Cañamero Amin Laglaoui Saïd Barrijal Antonio Gálvez 《World journal of microbiology & biotechnology》2008,24(7):997-1001
A bacteriocin-producing lactic acid bacterium (strain 2.5) isolated from cow’s milk used in cheese production from Northern
Morocco was selected for its strong anti-listerial activity. The producer strain was identified as Enterococcus faecalis by molecular methods. Strain 2.5 carried the genetic determinants for the two-peptide enterococcal bacteriocin enterocin
1071, and the active bacteriocin was purified to homogeneity by reversed-phase chromatography from culture broths of the producer
strain. Strain 2.5 carried two plasmids (of ∼7 and 40 kb). Characterization of strain 2.5 at biosafety level indicated that
this strain is non-haemolytic, and lacks the genetic determinants for most of the virulence factors described in enterococci
(cylB, cylM, gelE, ace and agg) although it carried the genetic determinants cylA, efaAfs as well as determinants for the sex pheromone peptides cpd, cob, and ccf. Strain 2.5 was resistant to tetracycline, rifampicin, and ciprofloxacin, but it was sensitive to penicillin, ampicillin,
vancomycin, and teicoplanin. Results from the present study support the potential role of strain 2.5 as an anti-listerial
agent to be tested in traditional fermented foods. 相似文献
14.
Torres R Ramón F de la Mata I Acebal C Castillón MP 《Applied microbiology and biotechnology》1999,53(1):81-84
At 28 °C, Streptomyces lavendulae produced high levels of penicillin V acylase (178 IU/l of culture) when grown on skim milk as the sole nutrient source for
275 h. The enzyme showed catabolite repression by glucose and was produced in the stationary phase of growth. Penicillin V
was a good inducer of penicillin V acylase formation, while phenoxyacetic acid, the side-chain moiety of penicillin V, did
not alter enzyme production significantly. The enzyme was stable between pH 6 and 11 and at temperatures from 20 °C to 55 °C.
This extracellular enzyme was able to hydrolyse natural penicillins and unable to hydrolyse penicillin G.
Received: 22 March 1999 / Received revision: 16 June 1999 / Accepted: 20 June 1999 相似文献
15.
Pereira GA Pimenta FP Santos FR Damasco PV Hirata Júnior R Mattos-Guaraldi AL 《Memórias do Instituto Oswaldo Cruz》2008,103(5):507-510
The increasing problems with multidrug resistance in relation to Corynebacterium, including C. diphtheriae, are examples of challenges confronting many countries. For this reason, Brazilian C. diphtheriae strains were evaluated by the E-Test for their susceptibility to nine antibacterial drugs used in therapy. Resistance (MIC < 0.002; 0.38 microg/ml) to penicillin G was found in 14.8% of the strains tested. Although erythromycin (MIC90 0.75 microg/ml) and azithromycin (MIC90 0.064 microg/ml) were active against C. diphtheriae in this study, 4.2% of the strains showed decreased susceptibility (MIC 1.0 microg/ml) to erythromycin. Multiple resistance profiles were determined by the disk diffusion method using 31 antibiotics. Most C. diphtheriae strains (95.74%) showed resistance to mupirocin, aztreonam, ceftazidime, and/or oxacillin, ampicillin, penicillin, tetracycline, clindamycin, lincomycin, and erythromycin. This study presents the antimicrobial susceptibility profiles of Brazilian C. diphtheriae isolates. The data are of value to practitioners, and suggest that some concern exists regarding the use of penicillin. 相似文献
16.
Wiyakrutta Suthep Sriubolmas Nongluksna Panphut Wattana Thongon Nuntawan Danwisetkanjana Kannawat Ruangrungsi Nijsiri Meevootisom Vithaya 《World journal of microbiology & biotechnology》2004,20(3):265-272
A total of 81 Thai medicinal plant species collected from forests in four geographical regions of Thailand were examined for
the presence of endophytic fungi with biological activity. Of 582 pure isolates obtained, 360 morphologically distinct fungi
were selected for cultivation on malt Czapek broth and yeast extract sucrose broth, from which extracts were tested for biological
activity. Extracts of 92 isolates could inhibit Mycobacterium tuberculosis (MIC 0.0625–200 μg ml−1) when tested by the microplate Alamar blue assay, while extracts of six inhibited Plasmodium falciparum (IC50 of 1.2–9.1 μg ml−1) as determined by the [3H]hypoxanthine incorporation method. Strong anti-viral activity against Herpes simplex virus type 1 was observed in 40 isolates
(IC50 of 0.28–50 μg ml−1). The sulphorhodamine B assay for activity against cancer cell lines revealed that 60 were active against human oral epidermoid
carcinoma cells (EC50 0.42–20 μg ml−1) and 48 against breast cancer cells (EC50 0.18–20 μg ml−1). Bioactivity profile was affected by the type of culture medium. Given the high incidence of bioactive extracts and the
fact that most of the isolated fungi could not be identified due to lack of spore formation, the results suggested that Thai
medicinal plants can provide a wide variety of endophytes that might be a potential source of novel bioactive compounds.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
M Jacques A Lebrun B Foiry M Dargis F Malouin 《Journal of general microbiology》1991,137(11):2663-2668
The effects of subminimal inhibitory concentrations (subMICs) of certain antibiotics, namely penicillin G, tetracycline and trimethoprim/sulphamethoxazole, on the growth and morphology of Pasteurella multocida were evaluated. SubMICs of penicillin markedly reduced the growth of P. multocida. Tetracycline and trimethoprim/sulphamethoxazole had no effect on its growth. SubMICs of penicillin greatly affected the morphology of P. multocida. At the highest concentrations tested (1/2 and 1/4 MIC) cells were acapsulate, and long filamentous cells (4-6 microns) were observed with some isolates. There was no correlation between the observed differences in the penicillin-binding proteins of the P. multocida isolates, and the extent of cell filamentation induced by penicillin G. SubMICs of tetracycline and trimethoprim/sulphamethoxazole did not seem to affect capsule production although filamentation was observed. Our results indicate that subMICs of penicillin can reduce growth of P. multocida. Furthermore, results also indicate that subMICs of antibiotics can affect the production of capsular material and the morphology of P. multocida. 相似文献
18.
Enhancement of antibiotic activity against Staphylococcus aureus by exposure to hyperbaric oxygen 总被引:2,自引:1,他引:1
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G H Bornside 《Applied microbiology》1967,15(5):1020-1024
Growth of Staphylococcus aureus ATCC 6538P was studied in stationary broth cultures (11 mm deep) exposed to hyperbaric oxygen (100% O2 at 3 atm absolute). The minimal inhibitory concentration (MIC) of the following antibiotics was determined after exposure to high-pressure oxygen (HPO) for 3, 6, and 12 hr: penicillin, streptomycin, tetracycline, oxytetracycline, kanamycin, and cephalothin. Logarithmic growth during exposure to HPO was retarded 60%. Air at 3 atm absolute did not retard growth. The longer the exposure of tube dilution tests to HPO, the lower the MIC. Regardless of the antibiotic used, MIC values relative to 100% for unexposed controls were similar for given exposures, and averaged 73% after 3 hr of exposure to HPO, 53% after 6 hr, and 34% after 12 hr. Similar enhancement with HPO and an iodophor suggests occurrence of a general phenomenon with antibacterial agents. Although HPO alone is primarily bacteriostatic, combined therapy with antibiotics and HPO may be useful against bacterial infections because the therapeutic effectiveness of a maximal dosage of antibiotic could be increased. 相似文献
19.
S. Quratulain B. Nasira M.A. Kashmiri 《World journal of microbiology & biotechnology》2006,22(3):213-218
Summary The penicillin G amidase (PGA) activity of a parent strain of E. coli (PCSIR-102) was enhanced by chemical mutagenization with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). After screening and optimization, a penicillinase deficient mutant (MNNG-37) was isolated and found
effective for the production of penicillin G amidase as compared to the parent strain of E. coli (PCSIR-102). Penicillin G amidase activity of MNNG-37 appeared during an early stage of growth, whereas PCSIR-102 did not
exhibit PGA activity due to the presence of penicillinase enzyme which inhibits the activity of enzyme PGA. However, MNNG-37
gave a three-fold increase in enzyme activity (231 IU mg−1) as compared to PCSIR-102 (77 IU mg−1) in medium containing 0.15 and 0.1% concentrations of phenylacetic acid, respectively which was added after 6 h of cultivation.
The difference in K
m values of the enzyme produced by parent strain PCSIR-102 (0.26 mM) and mutant strain MNNG-37 (0.20 mM) is significant (1.3-fold
increase in K
m value) which may show the superiority of the latter in terms of better enzyme properties. 相似文献
20.
Magdalena Wegiera Urszula Kosikowska Anna Malm Helena D. Smolarz 《Central European Journal of Biology》2011,6(6):1036-1043
This study was designed primarily to investigate the antibacterial and antifungal activity of the extracts from fruits of
six Rumex L. species: R. acetosa L., R. acetosella L., R. confertus Willd., R. crispus L., R. hydrolapathum Huds. and R. obtusifolius L. The 7 Grampositive and 7 Gram-negative bacteria strains and 5 fungal ones were tested by agar and broth dilution method.
Determination of minimal inhibitory concentration (MIC) revealed that the extracts from R. confertus, R. crispus, R. hydrolapathum and R. obtusifolius exerted differential inhibitory effect on the growth of Gram-positive bacteria — staphylococci (MIC=62.5–125 μg/mL) and Gramnegative
bacteria — Escherichia coli ATCC 3521, Proteus mirabilis, Pseudomonas aeruginosa (MIC=125→500 μg/mL); MIC values determined by agar dilution method were somewhat higher. The same extracts inhibited also
the growth of fungi — Candida spp. or Trichophyton mentagrophytes ATCC 9533 (MIC=250–500 μg/mL), as found by agar dilution method. The total content of polyphenols (11.66–78.36 mg/g), anthracene
derivatives (0.26–12.93 mg/g) and tannins (4.00–11.16%) was also determined. 相似文献