PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Microbial Sensitivity Tests”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1976

[Antibiotic sensitivity of the Salmonella isolated from humans ill with salmonellosis in 1967-1974].

Sensitivity to levomycetin, streptomycin, chlortetracycline, oxtetracycline, tetracycline, neomycin, monomycin and erythromycin of 548 fresh isolates of Salmonella of 32 serotypes of the main groups A, B, C, D and E was studied. The cultures were isolated from salmonellosis patients within 1967-1974. Sensitivity to neomycin, monomycin, levomycetin and streptomycin was found respectively in 96.9, 91.1, 76.5 and 74.8 per cent of the cultures. High sensitivity of the cultures was observed only to levomycetin (15.1 per cent). With respect to tetracyclines the isolates were mainly resistant (24.2-47.2 per cent) or low sensitive (25-26.5 per cent). 70.3 per cent of the strains were resistant to erythromycin and 24.1 per cent were of low sensitivity. The causative agents of typhoid fever, paratyphoid fever A and B were more sensitive to levomycetin and tetracycline as compared to other Salmonella. A polyvalent Salmonella bacteriophage lyzed from 94.2 to 100 per cent of the Salmonella cultures tested.

Anti-Bacterial Agents↗
PubMed1995

In-vitro activity of antibacterial drugs and clinical practice.

Before prescribing an antibiotic, treatment guidelines usually suggest that a specimen containing the suspected organism is sent for culture and sensitivity. Microbiology departments, for their part, use in-vitro sensitivity of isolates taken from patients with bacterial infections to recommend which antibiotic(s) to use in the patients themselves or as a guide to empirical treatment in others. In this article we consider the value of in-vitro testing to clinical practice.

Anti-Bacterial Agents↗
PubMed1992

In-vitro activities of 14-, 15- and 16-membered macrolides against gram-positive cocci.

The in-vitro activities of the 14-membered macrolides erythromycin, dirithromycin, roxithromycin, clarithromycin, the 15-membered compound azithromycin and the 16-membered macrolides (16 MM) josamycin, spiramycin and midecamycin acetate (MOM) have been compared against staphylococci, enterococci and streptococci. Results have been analysed separately according to the sensitivity status of the tested strains to erythromycin, namely sensitive (S), inducibly resistant (IR) or constitutively resistant (CR). 14- and 15-membered macrolides were active only against S strains; the order of potency in vitro was clarithromycin = erythromycin greater than azithromycin = roxithromycin greater than dirithromycin. The 16 MM were slightly less active against S strains than were the 14- and 15-membered compounds, and inhibited most IR strains; MOM and josamycin were about twice as potent as spiramycin. IR and S Staphylococcus aureus strains were equally sensitive to 16 MM, while IR strains of coagulase-negative staphylococci were less sensitive than were S strains. All CR strains of S. aureus were resistant to 16 MM, as were most of the other CR strains. However, 5/21 CR coagulase-negative staphylococci and 2/20 CR enterococci tested were sensitive to 16 MM. The seven CR strains showing anomalous sensitivity to the 16 MM (five Staphylococcus haemolyticus and two enterococci) were only 'moderately resistant' to erythromycin (MIC 8-64 mg/L), while all the other CR strains were 'highly resistant' (MIC greater than 128 mg/L). These results indicate that it may be difficult to predict the sensitivity of Gram-positive cocci to 16 MM, and therefore individual sensitivity testing to specific compounds is essential.

Anti-Bacterial Agents↗
PubMed1976

A new practical classification of the mycobacteria.

A new classification is presented for mycobacteria cultured from clinical specimens. Five categories were defined on temperature requirement, and these were subdivided into 14 groups by pigmentation, oxygen preference and Tween hydrolysis. Support for some of the groups and for the recognition of certain important species within others was provided by drug-sensitivity tests. Less than 1-0% of the opportunist mycobacteria met in Britain eluded classification by these means.

Culture Media↗
PubMed1975

The varying sensitivity to antibacterial agents of micro-organisms in pure vs. mixed cultures.

In this study the disc sensitivities of five organisms growing in pure cultures (Staphylococcus aureus, beta-hemolytic Streptococcus, Proteus mirabilis, Pseudomonas aeruginosa, and Candida albicans) were first determined against each of seven antibacterial agents (penicillin, streptomycin, gentamicin, kanamycin, silver nitrate, Sulfamylon, and Betadine). Then the sensitivity of each organism growing in combination with one of the others (10 combinations) was tested against each of the same antibacterials. Significantly increased and decreased sensitivities were found in 30 percent of the cultures with decreases largely predominating. Total obliteration of all sensitivity occurred 10 percent of the time. The changes in sensitivity were not distributed randomly but rather were associated more with particular agents and organisms. Sulfamylon, was associated with decreases 70 percent of the time with sensitivity obliteration in 50 percent of the tests. Streptococcus led all the organisms, being associated with decreases in half of the tests. It is possible that mixed-culture sensitivities could provide the most valid information when mixed infections exist, since they more closely simulate the real clinical situation. Therefore it is suggested that both mixed and pure culture sensitivity testing be done for all mixed infections.

Anti-Bacterial Agents↗
PubMed1975

[Effect of some antibiotics and chemotherapeutic preparations on Leptospira in vitro].

It was shown in vitro with the method of successive serial dilutions that polymyxin M, thilan, streptomycin, neomycin, sodium levomycetin succinate, brilliant green, tripaphlavin, azidin, aminoacrichin, and novarsenol had the most pronounced bactericidal effect on Leptospira. Combination of the antibiotics or the chemotherapeutics apart from azidin and tripaphlavin did not increase the bactericidal effect as compared to their use alone. The clinical and collection strains of Leptospira had the same sensitivity to the substances tested. The above drugs should be tested on animals with leptospirosis.

Anti-Bacterial Agents↗
PubMed1999

Increasing antimicrobial resistance in STDs and the need for surveillance: Neisseria gonorrhoeae as a model.

Neisseria gonorrhoeae has a rising trend of resistance against antimicrobials. Today, third generation cephalosporins are the only antibiotics for treatment of gonorrhea against which there is no resistance in gonococci. On the other hand, decreased susceptibility against this group, including ceftriaxone, has already been observed. This historically famous pathogen deserves current attention and is reviewed here with respect to its resistance mechanisms and patterns, and the problems concerning standardization of its susceptibility testing are discussed.

Drug Resistance, Microbial↗
PubMed1985

[Sensitivity of anaerobic bacteria to therapeutic agents (Zurich 1984)].

There are several reports in the literature on resistance of anaerobic bacteria against antimicrobial agents. Therefore, 231 anaerobic strains of various bacterial genera, isolated from clinical specimens during fall 1984, were tested for susceptibility to antimicrobial agents active against anaerobic bacteria. Whereas 23% of the Bacteroides species not belonging to the B. fragilis group were resistant to penicillin, the anaerobic bacteria were still susceptible to chloramphenicol, clindamycin and the nitroimidazoles. The resistance rate against the various new beta-lactam antibiotics was comparable to results of other studies. Due to the increasing resistance it is recommended that the susceptibility of clinically important anaerobes be tested by appropriate techniques. The agar diffusion test must not be used due to unreliable results. Instead, the minimal inhibitory concentration should be determined or the "broth-disk" test performed.

Bacteria, Anaerobic↗
PubMed1993

A comparison of microbial bioassays for the detection of metal toxicity.

Heavy metal toxicity was studied by assaying six microbiological toxicity tests, both in solution and wastewater. Pseudomonas fluorescens and baker's yeast (Saccharomyces cerevisiae) were used; growth and respirometric determinations were performed. In addition, the Microtox test was employed as a reference method. The Microtox test is the most sensitive assay for detecting toxicity of zinc, copper, and mercury but not for cadmium, chromium, and nickel. Wastewater increases the sensitivity threshold (EC20) and EC50 values of the metals in most of the assays, which is correlated to the presence of organic and inorganic compounds that can reduce the bioavailability of the metals, leading to a general loss of sensitivity. All the above-mentioned assays are potentially useful in the detection of chemical toxicity of metals. However, each test shows different sensitivities to each metal, which is related to different sensitivities of the organisms used in the assays, as well as to other factors. Therefore, it would be advisable to use a battery of tests for biological evaluation of metal toxicity.

Lethal Dose 50↗
PubMed1976

Prolonged pneumococcal meningitis due to an organism with increased resistance to penicillin.

For more than 30 years, penicillin has been the agent of choice for pneumococcal infections. During this time the majority of strains of Streptococcus pneumoniae have been highly susceptible to penicillin. However, during the last ten years there have been sporadic reports of pneumococci with increased resistance to penicillin. The case report of an 18-month-old white boy with meningitis due to a strain of S. pneumoniae with increased resistance to penicillin is presented. The MIC of the organism to penicillin was 0.2 mug/ml and the MBC 0.39 mug/ml. The patient had normal immunity and no demonstrable sequestered focus of infection but failed to respond to appropriate doses of intravenous penicillin. Treatment with chloramphenicol caused a dramatic bacteriologic and clinical response. This experience reemphasizes the existence of pneumococcal strains of intermediate penicillin sensitivity and the importance of in vitro susceptibility tests.

Humans↗
PubMed1985

In vitro activity of six antibiotics against multiresistant staphylococci and other gram-positive cocci.

Sixty-two strains of Staphylococcus aureus and coagulase-negative staphylococci, 21 Streptococcus faecalis and 17 other strains of streptococci isolated from cases of endocarditis were tested for sensitivity against rifampicin, teicoplanin, vancomycin, fusidic acid, erythromycin and novobiocin. Only rifampicin, novobiocin and teicoplanin were found to be active against the great majority of these strains. The microbial properties of these antibiotics suggest the necessity of combinations for effective therapy. The combinations rifampicin + novobiocin and rifampicin + teicoplanin were additive and suppressed the emergence of resistant mutants. Thus according to in vitro tests, either of these two combinations would be suitable for prophylactic use in high-risk patients, especially those scheduled to receive prosthetic implants.

Anti-Bacterial Agents↗
PubMed1980

Bacterial sensitivity test kit.

A method and an apparatus have been developed for the determination of the susceptibility of pathogenic bacteria to antibiotics. The method has the same applicability as the accepted Bauer-Kirby method. The method is rapid, the procedure for the performance of the test is simple, the supplies and equipment for the performance of the test are inexpensive and finally the test gives easily measurable end-points. The correlation of the method to the accepted Bauer-Kirby method against clinical isolates of gram-positive bacteria was 90-100% for the antibiotics tested with the exception of neomycin which was 80%. With gram-negative bacteria, the correlation was 92-100% for the antibiotics tested.

Humans↗
PubMedDate not supplied

Microbial isolates in open fractures seen in the accident and emergency unit of a teaching hospital in a developing country.

In this prospective study, superficial and deep swabs of all open fractures seen at the accident and emergency unit of our hospital between January and June 2000 were taken (before wound debridement was done or anitibiotics commenced). Routine microscopy, culture and sensitivities for aerobic and anaerobic organisms were carried out on these specimens. The organisms were cultured and identified using standard techniques and the antibiotic sensitivity testing was carried out using the disc diffusion method of Stokes. Within six hours of injury, single-organism isolates were commonly found whilst after 48 hours a mixed or poly-microbial organism load were isolated. In 90% of the positive isolates, the organisms isolated form the superficial and the deep swabs were the same. The antibiotic sensitivity pattern of all the isolates shows that pefloxacin, ciprofloxacin and ceftriaxone were more effective compared to cefuroxime and amoxycillin which had substantial resistance to most of the isolates. 41 fractures were followed to union and 4 (9.7%) developed osteomyelitis.

Anti-Bacterial Agents↗
PubMed2004

[Relationship between the endocervical mycoplasma infection and spontaneous abortion due to early embryonic death].

OBJECTIVE: To study the relationship between endocervical mycoplasma infection and the spontaneous abortion due to the early embryonic death and the drug sensitivity to mycoplasma. METHODS: Endocervical swabs were taken from fifty normal pregnant women (normal group) and fifty-eight women with spontaneous abortion due to embryonic death. The swabs were used for ureaplasma urealyticum (UU) and mycoplasma hominis (MH) Cultivation respectively. The isolation rates of the two groups were comparedf. RESULTS: (1) In the embryonic death group, the positive rates of UU, MH and UU mixed with MH were 74.1% (43/58), 27.6% (16/58) and 20.7% (12/58) separately. In the normal female group, however, the positive rates correspondingly were the UU 48.0% (24/50), the MH 10.0% (5/50) and the UU mixed with MH 4.0% (2/50). There had significant differences of the positive rates between the two groups (P < 0.01, P < 0.05, P < 0.05). (2) Drug sensitivity rates to mycoplasma were roxithromycin 94.6%, doxycycline 54.5% and ofloxacin 32.8%. (3) The infection rate of mycoplasma had no positive relationship with times of early embryonic death. CONCLUSIONS: (1) The endocervical mycoplasma infection could be one of the causes leading to the early embryonic death. (2) Roxithromycin was the most sensitive drug tested to mycoplasma.

Abortion, Spontaneous↗