Assay rapid microbiology

Conventional plate assays require several hours incubation and consequently the possibility of using rapid microbiological assay methods has been studied. Two such methods are ... 

Barea JM, Navarro E, Palomares A, Montoya E (1974) A rapid microbiological assay method for auxins, gibberellic acid and kinetin using yeast. J Appl Bacteriol 37 171-174... 

These types of assay are rapid, taking approximately 2 hours, show good precision and are much more specific than microbiological assays. 

Bedard, D. L., Unterman, R. D., Bopp, L. H., Brennan, M. J., Haberl, M. L. Johnson, C. (1986). Rapid assay for screening and characterizing microorganisms for the ability to degrade polychlorinated biphenyls. Applied and Environmental Microbiology, 51,761-8. 

A rapid semiautomated microdilution method for the microbiological assay of the chloroquine has been developed by Desgardins (26). Antimalarial activity of chloroquine may be studied against cultured Plasmodium falciparum, microplates are used to prepare serial dilution of the drug. Parasites obtained from continuous stock cultures are subcultured in the micro-plates for 42 h. Inhibition of uptake of a radio labeled nucleic acid precursor by parasites serves as the indicator of antimicrobial activity. 

Microbiological or immunochemical detection systems offer the advantage to screen, rapidly and at low cost, a large number of food samples for potential residues, but cannot provide definitive information on the identity of violative residues found in suspected samples. For samples found positive by the screening assays, residues can be tentatively identified and quantified by means of the combined force of an efficient liquid chromatographic (LC) separation and a selective physicochemical detection system such as UV, fluorescence, or electrochemical detection. The potential of pre- or postcolumn derivatiza-tion can further enhance the selectivity and sensitivity of the analysis. Nevertheless, unequivocal identification by these methods is not possible unless a more efficient detection system is applied. 

Chen F, Suzuki S, Kuhlman G, Venkateswaran K, Kem R. AMP based sensitive and rapid spore detection assay. 104 Atuual Meeting of American Society for Microbiology, New Orleans, May 2004. Q-081 page 518. 

Fahle, G.A., Parker, J.M., Fischer, S.H., and Gill, V.J. (1997) Rapid and sensitive detection of cytomegalovirus using PCR and the DELFIA time resolved fluorescence hybridization assay. Abstracts of the General Meeting of the American Society for Microbiology, 97, 153. 

Milk Residue Decline Study at 50 mg/quarter. Twenty-six dairy cattle in midlactation and identified as mastitic in one or more quarters were given two intramammary infusions of pirlimycin HCl into all 4 quarters of the udder at a 24-hour interval at a dose rate of 50 mg/quarter (IX). Each cow was milked at 11-13 hour intervals and sub-samples taken for microbiological assay. The results are summarized in Table VIII. As observed in previous studies, the decline of the concentration of pirlimycin residue appears to be bi-phasic with a rapid initial depletion followed by a slower terminal elimination phase. Statistical analysis of the residue decline to a concentration below the calculated safe concentration of 0.4 ppm [following FDA guidelines of applying a confidence interval of 95% on the 99th percentile (75)] support a 36-hour milk discard interval (48-hour safe milk) for pirlimycin in the US. 

It is very important to select promptly the most effective antibiotic for successful therapy of infectious diseases, and wound and post-surgical infections. The duration of standard microbiology assays applied in clinical practice exceeds 3-5 days since preliminary isolation of the pathogen from the clinical sample is required. In the present study we optimized a rapid bio luminescent antibiotic susceptibility assay based on comparison of bacterial ATP concentrations (bioluminescent signals) in a control (aliquot of the sample, free of the antibiotic) and probe (aliquot of the sample, supplied with antibiotic examined) after short-time incubation. For validation of the proposed assay, bacteria strains isolated from clinical samples were analyzed in parallel by the Bioluminescent Assay and Standard Microbiology Assay - Disk Method or Serial Dilutions Method. 

Lovley, D. R. Phillips, E. J. P. 1987. Rapid assay for microbially reducible ferric iron in aquatic sediments. Applied Environmental Microbiology, 53(7), 1536-1540. 

Research into new analytical techniques for foodstuffs continues, striving for greater accuracy, sensitivity or simplicity, for more rapid methods, for simultaneous multielement analysis, etc. Chromatographic techniques, e.g., LC, GLC, GC-MS, have led to great improvements in the levels of accuracy, sensitivity, and detection that can be achieved for many analytes including carbohydrates, certain vitamins, chemical residues, and additives. Work is still required, for instance, in the area of vitamin analysis in order to provide standard techniques that are applicable to all food types and that would enable concurrent multi-vitamin analysis to take place. Many of the microbiological assays currently used for vitamin determination involve long incubation times and more rapid techniques are needed. 

Bleve, G., Rizzotti, L., DeUaglio, F., Torriani, S. (2003). Development of reverse transcription (RT)-PCR and real-time RT-PCR assays for rapid detection and quantification of viable yeasts and molds contaminating yogurts and pasteurized food products. Applied and Environmental Microbiology, 69,4116-4122. 

Mycoplasmas can be cultured in liquid or oti solid media. However, in contrast with other bacteria, their growth is slow, and a microbiological assay as described in the Ph. Eur. is time-consuming (at least 28 days). Alternative, rapid methods, based on nucleic acid technologies such as PCR, have been developed [36, 39]. Under certain conditions these methods may be used as an alternative method instead of the official, growth based method [40]. 

Direct detection of p-lactamase activity has been established as a routine method in mai microbiological diagnostic laboratories (Hrabak et al. 2014). Especially in the case of a direct detection of caibapenemase activity, the MALDI-TOF MS hydrolysis assay should soon be accepted as a gold standard method and may serve as a reference technique together with spectrophotometric assays. The main advantage of MS tools is the ability to detect rapidly both antibiotic hydrolytic products and intact lactamases. 

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