scholarly journals Stability of Ready-to-Use and Laboratory-Prepared Culture Media

Author(s):  
S. I. Kuleshova ◽  
S. A. Protsak ◽  
S. A. Lisunova ◽  
G. Yu. Romanyuk

The culture media quality, which depends to a large extent on growth promotion properties, determines the reliability and accuracy of test results obtained by microbiological methods. The procedure for culture media preparation is quite labourconsuming and includes several stages: successive dissolution of components exactly as specified in the recipe (qualitative and quantitative composition), sterilisation, adjusting the pH of the medium, and testing of growth promotion properties—therefore it is important to demonstrate the stability of each particular culture medium.The aim of the study was to evaluate growth promotion properties of the culture media prepared in the laboratory from a dry mixture, and to assess their stability during long-term storage.Materials and methods: stability testing was performed for fluid thioglycollate medium (FTM) and soybean-casein digest broth (SCD) prepared in the laboratory. FTM growth promotion properties were tested  using the following test microorganisms: Bacillus subtilis ATCC 6633,  Clostridium sporogenes ATCC 19404, Pseudomonas aeruginosa ATCC 9027,  Staphylococcus aureus ATCC 6538. SCD growth promotion properties were  tested using: Aspergillus brasiliensis ATCC 16404, Candida albicans ATCC  10231, Bacillus subtilis ATCC 6633. The stability study was carried out for 6  months, assessing changes in appearance and growth promotion properties. The test media were stored at room temperature and in a refrigerator at 2–8 °C.Results: no growth of the anaerobic microorganism Clostridium sporogenes was observed in FTM after 3 months, regardless of storage conditions. Later on, there was no growth of the gram-positive microorganisms Bacillus subtilis and Staphylococcus aureus, which are more sensitive to the storage conditions than Pseudomonas aeruginosa. The growth promotion properties of the SCD prepared in the laboratory did not change during 6 months of storage.Conclusions: FTM prepared from a dry mixture remains stable and retains its growth promotion properties for no more than two months when stored in a refrigerator at 2–8 °C. SCD can remain stable for 6 months, both at room temperature and when stored in the refrigerator.

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.


2017 ◽  
Vol 74 (19) ◽  
pp. 1579-1583 ◽  
Author(s):  
Abdel Naser Zaid ◽  
Rania Shtayah ◽  
Ayman Qadumi ◽  
Mashour Ghanem ◽  
Rawan Qedan ◽  
...  

Abstract Purpose The stability of an extemporaneously prepared rosuvastatin suspension stored over 30 days under various storage conditions was evaluated. Methods Rosuvastatin suspension was extemporaneously prepared using commercial rosuvastatin tablets as the source of active pharmaceutical ingredient. The organoleptic properties, dissolution profile, and stability of the formulation were investigated. For the stability studies, samples of the suspension were stored under 2 storage conditions, room temperature (25 °C and 60% relative humidity) and accelerated stability chambers (40 °C and 75% relative humidity). Viscosity, pH, organoleptic properties, and microbial contamination were evaluated according to the approved specifications. High-performance liquid chromatography was used for the analysis and quantification of rosuvastatin in selected samples. Microbiological investigations were also conducted. Results The prepared suspension showed acceptable organoleptic properties. It showed complete release of rosuvastatin within 15 minutes. The pH of the suspension was 9.8, which remained unchanged during the stability studies. The microbiological investigations demonstrated that the preparation was free of any microbial contamination. In addition, the suspension showed stability within at least the period of use of a 100-mL rosuvastatin bottle. Conclusion Extemporaneously prepared rosuvastatin 20-mg/mL suspension was stable for 30 days when stored at room temperature.


Author(s):  
Umeh Odera Richard ◽  
E. I. Chukwura ◽  
Ibo Eziafakaego Mercy

A fish pond with recommended water quality will produce healthy fishes. Fish ponds with poor water quality will cause fish mortality and outbreak of diseases to fish consumers. Physicochemical analysis was done using standard analytical methods, the total bacterial count was determined by dilution and membrane filtration techniques. Parasitological analysis was done using the centrifugation method. A total of fifteen well waters were sampled during wet season. Results showed that the temperature ranged from 27°C to 29°C, pH, 6.21 to 8.15; dissolved oxygen, 4.28 mg/l to 5.78 mg/l, electrical conductivity, 166.36 µs/cm to 394.00 µs/cm; total dissolved solids, 41 mg/l to 121 mg/l; total suspended solids, 1.00 mg/l to 19.40 mg/l; total solids, 42.00 mg/l to 140.4 mg/l; turbidity values, 7.01 NTU to 10.36 NTU; nitrate, 3.10 mg/l to 28.00 mg/l; total alkalinity, 36 mg/l to 91 mg/l; phosphate, 1.26 mg/l to 13.11 mg/l; sulphate, 0.39 mg/l to 4.37 mg/l; total chloride, 7.08 mg/l to 14.19 mg/l; carbonates, 1.33 mg/l to 2.35 mg/l; bicarbonates, 34.59 mg/l to 89.38 mg/l; total hardness, 25.31 mg/l to 53.04 mg/l; calcium hardness, 23.94 mg/l to 51.96 mg/l; magnesium hardness, 1.08 mg/l to 4.20 mg/l; total acidity, 2 mg/l to 22 mg/l; potassium, 0.04 mg/l to 2.23 mg/l; cadmium, 0.00 mg/l to 0.04 mg/l; lead, 0.01 mg/l - 0.16 mg/l; chromium, 0.00 mg/l - 0.03 mg/l; mercury was not detected, copper, 0.00 mg/l - 0.04 mg/l; arsenic, 0.00 mg/l - 0.02 mg/l; zinc, 0.00 mg/l to 0.02 mg/l; iron, 0.01 mg/l - 1.19 mg/l. The total bacterial counts ranged from 3.60-4.12 log cfu/ml; total coliforms, 14-46 cfu/100ml, Vibrio cholerae, 0-11 cfu/100ml; Vibrio parahaemolyticus, 0-15 cfu/100ml; faecal coliform, 1-9 cfu/100 ml; Acinetobacter calcoaceticus, 0-8 cfu/100 ml; Bacillus subtilis, 0-9 cfu/ml; Staphylococcus aureus, 0-5 cfu/ml; Pseudomonas aeruginosa, 0-12 cfu/100 ml; Pseudomonas fluorescens, 0-12 cfu/100 ml and Clostridium perfringens were not detected in any of the samples. Twelve bacterial species namely Klebsiella pneumoniae, Acinetobacter calcoaceticus, Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Pseudomonas fluorescens, Pseudomonas aeruginosa, Proteus mirabilis, Vibrio parahaemolyticus, Bacillus subtilis, Shigella flexineri and Salmonella typhi were isolated and identified using standard analytical and molecular procedures. Parasites identified were Ichthyobodo species, Diplostomum species, Myxobolus species, Chilodonella species, Bothriocephalus species, Ambiphrya species and Leech species. Salmonella typhi had the highest frequency of isolation (20.63%) while Acinetobacter calcoaceticus and Staphylococcus aureus had the lowest frequency of isolation (2.83%). Ichthyobodo species had the highest frequency of isolation (21.43%) while Leech species had the lowest frequency of isolation (5.71%). Some of the physicochemical, bacteriological and parasitological parameters had values above World Health Organization admissible limits and therefore proper sanitary practices and water treatments must be employed to prevent epidemic among fish consumers.


2020 ◽  
Vol 39 (03) ◽  
Author(s):  
VĂN HỒNG THIỆN ◽  
LÊ BÍCH TRÂM ◽  
NGUYỄN THANH LAN ◽  
HỒ NGUYỄN HOÀNG YẾN ◽  
LƯU HỒNG TRƯỜNG ◽  
...  

Nghiên cứu này đã xác định được mẫu nghiên cứu thu tại Vườn quốc gia Phú Quốc là loài Homalomena pierreana. Thông qua kỹ thuật sắc ký ghép khối phổ, 10 hợp chất thuộc nhóm sesquiterpene có trong cao chiết ethanol của thân rễ loài H. pierreana đã được xác định. Ngoài ra, cao chiết ethanol từ mẫu nghiên cứu cũng cho thấy khả năng kháng lại 6 chủng vi khuẩn kiểm định là Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis và Salmonella typhimurium.


Author(s):  
LUCIANA HELENA MAIA PORTE ◽  
MARIA HELENA MIGUEZ ROCHA LEÃO ◽  
ALEXANDRE PORTE

Lactoferrina bovina (bLF), proveniente do soro de leite, foimicroencapsulada pela técnica de spray drying. Microcápsulascontendo 20 % de bLF foram produzidas, utilizando-se comomaterial de parede dextrina: amido octenilsuccinato (OSA) emdiferentes proporções: 100:00, 75:25, 50:50, 25:75 e 0:100 %.Foram avaliadas a cor e a estabilidade de cor das microcápsulassob armazenamento em ambientes com diferentes umidadesrelativas e a atividade antimicrobiana da lactoferrina liberadadas microcápsulas. As microcápsulas apresentaram cor clara etenderam a escurecer sob armazenamento em ambiente com altaumidade relativa. Verifi cou-se atividade inibitória das microcápsulasde bLF produzidas para diferentes bactérias Gram positivas(Bacillus subtilis CCT 2576, Staphylococcus aureus CCT 2740,Micrococcus luteus CCT 2692, Enterococcus faecium CCT 5079,Streptococcus faecium ATCC 10541, Rhodococcus equi CCT0541), Gram negativas (Pseudomonas aeruginosa ATCC 13388,Salmonella choleraesius CCT 4296, Escherichia coli CCT 0547) elevedura (Candida albicans ATCC 10231). A concentração inibitóriamínima (MIC) das microcápsulas variou de acordo com o microorganismotestado (MIC entre 2,5-100 mg.mL-1). Com exceção deB. subtilis (MIC entre 50-100 mg.mL-1 para as microcápsulas), aconcentração de bLF contida nas microcápsulas necessária parainibir o crescimento dos micro-organismos foi menor do que a bLFnativa. Esses resultados sugerem efeito de potencialização daatividade antimicrobiana da bLF após o processamento por spraydrying.


Author(s):  
Luz Karime Medina-cÓrdoba ◽  
Ligia Lucia Valencia-mosquera ◽  
Gretty Paola Tarazona-diaz ◽  
Janeth Del Carmen Arias-palacios

Objective: To evaluate the efficacy of a disinfectant based on hydrogen peroxide.Methods: The method used to assess the efficacy of the disinfectant was the agar plate technique. With this procedure, it was possible to determine the percentage of inhibition of the high-level disinfectant of STERIS against four microorganisms, i.e., Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus (Beta-Hemolytic 227), Salmonella choleraesuis (Kuznedorf CMDM 074), and Bacillus subtilis (ATCC 6633). The effectiveness of five disinfectant concentrations (0.02%, 0.04%, 0.08%, 1%, and 2%) was determined and evaluated in three different times 5, 10, and 15 min, for vegetative strains and 3, 6, and 9 h for the sporulated strain.Results: According to the experimental test, the reduction of the microbial population was, on average, 100% for the disinfectant concentrations of 0.08%, 1%, and 2%.Conclusion: The results obtained demonstrated that the high-level disinfectant of STERIS based on hydrogen peroxide is 100% effective when the concentration recommended by the commercial house (2%) is used in the shortest time exposure to disinfectant. The minimum level of effectiveness was 0.08%; however, if lower concentrations are used, destruction of the microorganisms is not guaranteed.


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Daniyar Sadyrbekov ◽  
Timur Saliev ◽  
Yuri Gatilov ◽  
Ivan Kulakov ◽  
Roza Seidakhmetova ◽  
...  

A cyclopropane derivative of limonene, (1 S, 4 S, 6 R)-7,7-dichloro-4-[(1 S)-2,2-dichloro-1-methylcyclopropyl]-1-methylbicyclo [4.1.0] heptane (compound 2), was synthesized and its structure was determined by NMR and X-ray crystallographic methods. In addition, an antimicrobial activity of the compound against Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli, Pseudomonas aeruginosa) bacterial strains was also scrutinized.


2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Corina Danciu ◽  
Florin Borcan ◽  
Codruta Soica ◽  
Istvan Zupko ◽  
Erzsébet Csányi ◽  
...  

In recent years polyurethane microstructures (PM) have gained increasing attention in the pharmaceutical field due to the importance of their practical application. Since finding that such a formulation with genistein could improve its applications, we have conducted a preliminary study regarding the in vitro antiproliferative (MCF7, MDA-MB-231 and T47D) and antimicrobial ( Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis (D), Bacillus subtilis, B. cereus, and Candida albicans) activity in order to test whether polyurethane micro structuresre present a good option for further modulation of genistein's bioavailability. It was concluded that the polyurethane micro structures are a bad in vitro partner for the isoflavone genistein.


1985 ◽  
Vol 6 (6) ◽  
pp. 237-239 ◽  
Author(s):  
George H. Talbot ◽  
Maureen Skros ◽  
Mary Provencher

AbstractWe investigated the feasibility of transducer head disinfection with 70% alcohol wipes. In the initial trial, nine gas-sterilized transducers were inoculated with an estimated 5 × 106 organisms of a clinical isolate of Enterobacter cloacae, mimicking a contaminated fluid couple. A sterile disposable transducer dome was attached to each transducer. The units were allowed to sit for 24 hours at room temperature; the domes were then removed. Three transducer heads were cultured prior to disinfection to ensure that viable organisms remained. Each transducer head was wiped clean with a single alcohol wipe, allowed to dry, and then cultured. All nine cultures showed growth of E. cloacae. A second series of trials with 54 transducers employed an identical protocol, except that each transducer head received not one, but two, applications of alcohol. In addition to E. cloacae (26 runs), Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans were employed in nine, nine and ten runs, respectively. Cultures of 53 of 54 transducer heads showed no growth; the single positive culture was attributed to an error in technique. These preliminary results suggest that the double-alcohol-wipe technique may be an easy, cost-effective, alternative or supplemental method of transducer head disinfection. However, we do not advocate routine implementation of this technique in patient care settings until clinical trials confirm its safety and efficacy.


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