MyMedR

A simple high-performance liquid chromatographic method was developed for the determination of omeprazole in human plasma. Omeprazole and the internal standard, chloramphenicol, were extracted from alkalinized plasma samples using dichloromethane. The mobile phase was 0.05 M Na2HPO4-ACN (65:35, v/v) adjusted to pH 6.5. Analysis was run at a flow rate of 1.0 ml/min at a detection wavelength of 302 nm. The method was specific and sensitive with a detection limit of 2.5 ng/ml at a signal-to-noise ratio of 4:1. The limit of quantification was set at 5 ng/ml. The calibration curve was linear over a concentration range of 5-1280 ng/ml. Mean recovery value of the extraction procedure was about 96%, while the within and between day coefficient of variation and percent error values of the assay method were all less than 14%.

Matched MeSH terms: Chloramphenicol/blood

In vitro anti-bacterial and time kill evaluation of binuclear tricyclohexylphosphanesilver(I) dithiocarbamates, {Cy3PAg(S2CNRR')}2

Tan YJ, Tan YS, Yeo CI, Chew J, Tiekink ERT

J Inorg Biochem, 2019 03;192:107-118.

PMID: 30640150 DOI: 10.1016/j.jinorgbio.2018.12.017

Four binuclear phosphanesilver(I) dithiocarbamates, {cyclohexyl3PAg(S2CNRR')}2 for R = R' = Et (1), CH2CH2 (2), CH2CH2OH (3) and R = Me, R' = CH2CH2OH (4) have been synthesised and characterised by spectroscopy and crystallography, and feature tri-connective, μ2-bridging dithiocarbamate ligands and distorted tetrahedral geometries based on PS3 donor sets. The compounds were evaluated for anti-bacterial activity against a total of 12 clinically important pathogens. Based on minimum inhibitory concentration (MIC) and cell viability tests (human embryonic kidney cells, HEK 293), 1-4 are specifically active against Gram-positive bacteria while demonstrating low toxicity; 3 and 4 are active against methicillin resistant S. aureus (MRSA). Across the series, 4 was most effective and was more active than the standard anti-biotic chloramphenicol. Time kill assays reveal 1-4 to exhibit both time- and concentration-dependent pharmacokinetics against susceptible bacteria. Compound 4 demonstrates rapid (within 2 h) bactericidal activity at 1 and 2 × MIC to reach a maximum decrease of 5.2 log10 CFU/mL against S. aureus (MRSA).

Matched MeSH terms: Chloramphenicol/pharmacology

Chloramphenicol (chloromycetin) in the chemoprophylaxis of scrub typhus. IV. Relapses of scrub typhus in treated volunteers and their prevention

Smadel JE, Bailey CA, Diercks FH

Am J Hyg, 1950;51:229-41.

DOI: 10.1093/oxfordjournals.aje.a119387

Two field trials were conducted in Malaya in which 75 volunteers were exposed in hyperendemic areas of scrub typhus. Thirty-four of these individuals received chloromycetin prophylactically for a total period of 3 weeks during and following exposure. They did not show clinical evidence of scrub typhus throughout the period of prophylaxis or the ensuing 5 days. However, scrub typhus developed in 15 volunteers in the prophylactic groups of the two trials 5 to 14 days after drug was discontinued. Although the attack rate among the volunteers in the two field trials varied markedly, there was no essential difference in the ultimate infection rates among the controls and those given prophylaxis in each test. Scrub typhus when it developed among volunteers in the prophylactic group was not significantly different from the disease in the controls except for the absence of eschar formation. Relapses were prominent features of the disease in the volunteers of both prophylactic and control groups. These had not been observed previously in untreated cases of scrub typhus or in naturally occurring cases which were treated with chloromycetin. Fifty-four per cent of the 37 persons in the two trials who contracted scrub typhus suffered one or more relapses. Various factors probably contributed to this phenomenon but the opinion is that the short course of chloromycetin therapy given very early in the illness probably was an important factor. Ten volunteers had received experimental scrub typhus vaccine during earlier investigations because of possible exposure to infection. The vaccination did not influence the incidence of infection or the course of the disease in those persons developing scrub typhus. Prolonged administration of chloromycetin as a prophylactic measure and its use in the treatment of the initial attacks of scrub typhus, as well as the relapses, indicated that the drug is of low toxicity for man, and that drug fast strains of Rickettsia tsutsugamushi are not readily produced.

Matched MeSH terms: Chloramphenicol

Fulltext Imported cases of chloramphenicol resistant Salmonella typhi

Cheong YM, Jegathesan M

Med J Malaysia, 1992 Dec;47(4):331.

PMID: 1303490

Matched MeSH terms: Chloramphenicol Resistance*

Plasmid incidence rate and conjugative chloramphenicol and tetracycline resistance plasmids in Malaysian isolates of Salmonella typhi

Phipps M, Pang T, Koh CL, Puthucheary S

Microbiol. Immunol., 1991;35(2):157-61.

PMID: 1886492

Seven (6.1%) of 115 strains of Salmonella typhi isolated from Malaysian patients harbored a single large plasmid of 71 to 166 mD. Two of the seven plasmid-bearing strains were resistant to chloramphenicol (Cm) and tetracycline (Tc) and they transferred Cm and Tc resistance traits to Escherichia coli K12 at frequencies from 1.6 x 10(-7) to 1.9 x 10(-6). Agarose gel electrophoresis provided evidence that the resistance traits were cotransferred on a conjugative plasmid. The significance and importance of these results are discussed.

Matched MeSH terms: Chloramphenicol Resistance/genetics*

Hyphaema and badminton eye injuries

Chandran S

Med J Malaya, 1972 Mar;26(3):207-10.

PMID: 5031018

Matched MeSH terms: Chloramphenicol/therapeutic use

Chloramphenicol in the chemoprophylaxis of scrub typhus; epidemiological observations on hyperendemic areas of scrub typhus in Malaya

PHILIP CB, TRAUB R, SMADEL JE

Am J Hyg, 1949 Jul;50(1):63-74.

PMID: 18135592

Matched MeSH terms: Chloramphenicol*

Purulent meningitis in childhood

Lee EI, Khoo BH, Puthucheary SD, Thong ML

Med J Malaysia, 1977 Dec;32(2):114-9.

PMID: 26858

Matched MeSH terms: Chloramphenicol/therapeutic use

Study of one hundred cases of typhoid fever in University Hospital Kuala Lumpur (October 1967 to July 1972)

Kong TE

Med J Malaysia, 1976 Sep;31(1):20-5.

PMID: 1023008

Matched MeSH terms: Chloramphenicol/therapeutic use

MELIOIDOSIS: REPORT ON A FATAL CASE IN A BRITISH SOLDIER

MONTGOMERY R

J R Army Med Corps, 1963;109:223-7.

PMID: 14078072

Matched MeSH terms: Chloramphenicol*

Enteric fever problems in a small Malayan town

DIDSBURY B

Med J Malaya, 1953 Dec;8(2):192-201.

PMID: 13164690

Matched MeSH terms: Chloramphenicol/therapeutic use*

Unveiling synergism of polymyxin B with chloramphenicol derivatives against multidrug-resistant (MDR) Klebsiella pneumoniae

Idris N, Leong KH, Wong EH, Abdul Rahim N

J Antibiot (Tokyo), 2023 Dec;76(12):711-719.

PMID: 37821539 DOI: 10.1038/s41429-023-00659-2

Polymyxins are last-line antibiotics against multidrug-resistant Klebsiella pneumoniae but using polymyxins alone may not be effective due to emerging resistance. A previous study found that combining polymyxin B with chloramphenicol effectively kills MDR K. pneumoniae, although the bone marrow toxicity of chloramphenicol is concerning. The aim of this study is to assess the antibacterial efficacy and cytotoxicity of polymyxin B when combined with chloramphenicol and its derivatives, namely thiamphenicol and florfenicol (reported to have lesser toxicity compared to chloramphenicol). The antibacterial activity was evaluated with antimicrobial susceptibility testing using broth microdilution and time-kill assays, while the cytotoxic effect on normal bone marrow cell line, HS-5 was evaluated using the MTT assay. All bacterial isolates tested were found to be susceptible to polymyxin B, but resistant to chloramphenicol, thiamphenicol, and florfenicol when used alone. The use of polymyxin B alone showed bacterial regrowth for all isolates at 24 h. The combination of polymyxin B and florfenicol demonstrated additive and synergistic effects against all isolates (≥ 2 log10 cfu ml-1 reduction) at 4 and 24 h, respectively, while the combination of polymyxin B and thiamphenicol resulted in synergistic killing at 24 h against ATCC BAA-2146. Furthermore, the combination of polymyxin B with florfenicol had the lowest cytotoxic effect on the HS-5 cells compared to polymyxin B combination with chloramphenicol and thiamphenicol. Overall, the combination of polymyxin B with florfenicol enhanced bacterial killing against MDR K. pneumoniae and exerted minimal cytotoxic effect on HS-5 cell line.

Matched MeSH terms: Chloramphenicol/pharmacology

Effect of pyrolysis temperature on characteristics and chloramphenicol adsorption performance of NH2-MIL-53(Al)-derived amine-functionalized porous carbons

Tran TV, Jalil AA, Nguyen DTC, Nguyen TTT, Nguyen LTT, Nguyen CV, et al.

Chemosphere, 2024 May;355:141599.

PMID: 38548079 DOI: 10.1016/j.chemosphere.2024.141599

Several activities such as aquaculture, human and feedstock therapies can directly release antibiotics into water. Due to high stability, low hydrolysis and non-biodegradation, they can accumulate in the aqueous environment and transport to aquatic species. Here, we synthesized amine-functionalized porous carbons (ANC) by a direct-pyrolysis process of NH2-MIL-53(Al) as a sacrificial template at between 600 and 900 °C and utilized them to eliminate chloramphenicol antibiotic from water. The NH2-MIL-53(Al)-derived porous carbons obtained high surface areas (304.7-1600 m2 g-1) and chloramphenicol adsorption capacities (148.3-261.5 mg g-1). Several factors such as hydrogen bonding, Yoshida hydrogen bonding, and π-π interaction, hydrophobic interaction possibly controlled adsorption mechanisms. The ANC800 could be reused four cycles along with high stability in structure. As a result, NH2-MIL-53(Al)-derived porous carbons are recommended as recyclable and efficient adsorbents to the treatment of antibiotics in water.

Matched MeSH terms: Chloramphenicol*

Fulltext Isolation and characterization of cyclo-(tryptophanyl-prolyl) and chloramphenicol from Streptomyces sp. SUK 25 with antimethicillin-resistant Staphylococcus aureus activity

Alshaibani MM, Jalil J, Sidik NM, Edrada-Ebel R, Zin NM

Drug Des Devel Ther, 2016;10:1817-27.

PMID: 27330275 DOI: 10.2147/DDDT.S101212

BACKGROUND: Zingiber spectabile, commonly known as Beehive Ginger, is used as an ethnobotanical plant in many countries as an appetizer or to treat stomachache, toothache, muscle sprain, and as a cure for swelling, sores and cuts. This is the first report of isolation of Streptomyces strain from the root of this plant. Strain Universiti Kebangsaan 25 (SUK 25) has a very high activity to produce secondary metabolites against methicillin-resistant Staphylococcus aureus (MRSA), which is associated with high morbidity and mortality rates due to acquired multidrug resistance genes and causes medication failure in some clinical cases worldwide. Phylogenetic analysis based on the 16S ribosomal RNA gene sequence exhibited that the most closely related strain was Streptomyces omiyaensis NBRC 13449T (99.0% similarity).

AIM: This study was conducted to carry out the extraction, identification, and biological evaluation of active metabolites isolated from SUK 25 against three MRSA strains, namely, MRSA ATCC 43300, MRSA ATCC 33591, and MRSA ATCC 49476.

MATERIALS AND METHODS: The production of secondary metabolites by this strain was optimized through Thronton's media. Isolation, purification, and identification of the bioactive compounds were carried out using reversed-phase high-performance liquid chromatography, high-resolution mass spectrometry, Fourier transform infrared, and one-dimensional and two-dimensional nuclear magnetic resonance.

RESULTS: During screening procedure, SUK 25 exhibited good antimicrobial potential against several strains of MRSA. The best biological activity was shown from fraction number VII and its subfractions F2 and F3 with minimum inhibitory concentration values at 16 µg/mL and 8 µg/mL, respectively. These two subfractions were identified as diketopiperazine cyclo-(tryptophanyl-prolyl) and chloramphenicol.

CONCLUSION: On the basis of obtained results, SUK 25 isolated from Z. spectabile can be regarded as a new valuable source to produce secondary metabolites against bacteria, especially MRSA.

Matched MeSH terms: Chloramphenicol/isolation & purification*; Chloramphenicol/pharmacology*; Chloramphenicol/chemistry

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