Manual Microbiological Turbidimetric Analysis of Chlortetracycline in Feeds

1974 ◽  
Vol 57 (3) ◽  
pp. 527-535
Author(s):  
Hussein S Ragheb ◽  
Anne M Cummings
Keyword(s):  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Salmonella Gallinarum ◽  
Turbidimetric Method ◽  
Plate Assay ◽  
Response Slope ◽  
Aoac Method ◽  
Turbidimetric Assay ◽  
Turbidimetric Analysis ◽  
Suitable Organism

Abstract The turbidimetric log-probability plots of chlortetracycline HCl (CTC-HCl) showed the same dosage-response slope for Staphylococcus aureus, Streptococcus faecalis, and Bacillus cereus. The slope was different for Klebsiella pneumoniae and Salmonella gallinarum. In Penassay broth at pH 7.0, S. aureus appeared to be the most suitable organism for turbidimetric assay of CTC-HCl in feeds. The useful range was between 0.04-0.14 μg CTC-HCl. Two commercial unmedicated feeds (A and B) were each fortified at finished feed levels by addition of premixes containing CTC-HCl alone or in combination with penicillin and sulfamethazine. CTC-HCl recovery from feed A was 97.5— 107.2% turbidimetrically and 99.5-123.2% by the AOAC method, 38.179-38.182. Comparable results for feed B were 87.1-93.3% (turbidimetric) and 99.4-108.3% (AOAC). For both feeds, the overall coefficient of variation was higher (9.5-23.9%) for the manual turbidimetric assay than for the plate assay (5.5— 6.0%). Comparison of the 2 methods for analysis of premix samples showed essentially the same CTC-HCl recovery and comparable precision. The main advantage of the manual turbidimetric method over the plate assay is that results can be obtained within the same day of analysis.

Microbiological Assay of Oxytetracycline in Feed: Manual Turbidimetric Assay and Plate Assay

1973 ◽  
Vol 56 (1) ◽  
pp. 23-30
Author(s):  
Hussein S Ragheb ◽  
Anne M Cummings ◽  
Barbara M Browning
Keyword(s):  
Coefficient Of Variation ◽  
Microbiological Assay ◽  
Plate Method ◽  
Turbidimetric Method ◽  
Plate Assay ◽  
Coefficients Of Variation ◽  
Aoac Method ◽  
Turbidimetric Assay ◽  
Turbidimetric Analysis ◽  
Feed Samples

Abstract The useful range for manual turbidimetric analysis of Oxytetracycline (OTC), using K. pneumoniae, was between 0.04 and 0.08 μg/ml in the assay tubes. Laboratory-prepared feeds containing 43.5 and 86.5 g OTC.HCl/ton gave 90–98% recovery by the turbidimetric method and 104–116% by the AOAC method, 38.211–38.213. The coefficients of variation were 9.2–13.0 and 10.2–12.8%, respectively. Feeds containing 50 and 100 g OTC.HCl and neomyein sulfate/ton gave 77% of theory when analyzed turbidimetrically and 95% of theory by the plate method. The coefficient of variation for the turbidimetric method was about 16%, indicating unsatisfactory precision. At 200 g/ton theoretical concentration of each antibiotic, both methods agreed. Commercial premixes and finished feed samples gave almost the same results by both methods. The main advantage of the turbidimetric method over the plate assay is that results can be obtained the same day of analysis.

Turbidimetric and Diffusion Assay of Bacitracin in Feeds

1976 ◽  
Vol 59 (3) ◽  
pp. 526-535
Author(s):  
Hussein S Ragheb ◽  
Lisa Black ◽  
Sherrie Graham
Keyword(s):  
Ion Concentration ◽  
Median Response ◽  
Turbidimetric Method ◽  
Phosphate Ion ◽  
Plate Assay ◽  
Accuracy And Precision ◽  
Turbidimetric Assay ◽  
Zinc Bacitracin ◽  
Diffusion Assay ◽  
And Diffusion

Abstract A manual turbidimetric method for determining zinc or methylene disalicylate bacitracin in feeds was developed. When zinc ions (10−4M) were added to the medium and the phosphate ion concentration in standard solutions was decreased to 1%, the median response of Streptococcus faecalis was about 0.038 unit. Feeds analyzed by the turbidimetric assay should be prewashed with petroleum ether and extracted with pyridine as in 42.204. Zinc bacitracin standards added to swine and broiler rations were recovered at 93.1–102.6% by the turbidimetric method. Excellent agreement between the manual turbidimetric method and the plate assay was also obtained for finished feeds containing the zinc or methylene disalicylate salt of the antibiotic. The turbidimetric method appears to have high accuracy and precision. It is more rapid and less costly than the plate assay.

Microbiological Turbidimetric Analysis of Low Chlortetracycline Concentrations in Feeds

1975 ◽  
Vol 58 (3) ◽  
pp. 602-608
Author(s):  
Hussein S Ragheb ◽  
Linda S Porubcan
Keyword(s):  
Bacterial Growth ◽  
Room Temperature ◽  
Cattle Feed ◽  
Standard Curve ◽  
Turbidimetric Method ◽  
Feed Supplements ◽  
Turbidimetric Assay ◽  
Swine Feed ◽  
Low Levels ◽  
Turbidimetric Analysis

Abstract Recovery studies in which chlortetracycline hydrochloride (CTC-HCl) standard was added to cattle and swine feed supplements at 4.09–9.99 g/ton showed lower antibiotic recovery turbidimetrically (80.6–98.7%) than by the AOAC modified standard as in 38.179(d) (91.2–98.7%) and the plain buffer as in 38.179(b) (93.8-133.0%) methods. Three feeds fortified with a commercial premix at the levels of 5.0 and 10.0 g CTC-HCl/ton showed an overall CTC-HCl recovery of 87.6–110.6% by manual turbidimetric assay. Results were 89.1–108.7% by the AOAC inactivated feed diluent standard and 95.4–125.4% by the plain buffer methods. For some sample extracts (as in cattle feed) the use of heat to stop bacterial growth in the turbidimetric method caused formation of a precipitate. Cooling of cultures to room temperature and rapid reading of sample turbidity followed by standard curve concentrations minimized this interference. The manual turbidimetric assay of low levels of CTC-HCl in feeds appears to offer advantages over other methods.

Microbiological Plate and Turbidimetric Assays of Chlortetracycline in Feeds: Collaborative Study

1977 ◽  
Vol 60 (5) ◽  
pp. 1119-1124
Author(s):  
Hussein S Ragheb
Keyword(s):  
Statistical Difference ◽  
Collaborative Study ◽  
Plate Method ◽  
Standard Curve ◽  
Turbidimetric Method ◽  
Plate Assay ◽  
Significant Difference ◽  
Turbidimetric Assay ◽  
Swine Feed ◽  
Feed Samples

Abstract The manual and automated turbidimetric assays and a modified official plate assay for Chlortetracycline (CTC-HCl) in feed were collaboratively studied. Three feed samples (swine feed, 100 g CTC-HCl/ton; premix I, 20 g each of CTC-HCl and sulfamethazine/lb, and 10 g penicillin/lb; and premix II, 50 g CTC-HCl/lb) were analyzed at 2 dilutions. Twelve laboratories conducted the plate assay; 8 laboratories, the manual turbidimetric method ; and 7 laboratories, the Autoturb analysis. Within a method, there was no significant difference between dilutions. Between methods, there was a significant difference between the manual turbidimetric plate assays only for swine feed. However, the same sample dilutions or the average values of the 2 dilutions for both methods showed no statistical difference. Among the collaborators, the slope of CTC-HCl standard curve varied between about 2.0 and 3.0 for the plate method. The turbidimetric assay has been adopted as official first action for feeds containing >20 g CTC-HCl/lb.

Activité antibactérienne de l’huile essentielle de Pelargonium x asperum et son potentiel synergique avec la nisine

2019 ◽  
Vol 17 (3) ◽  
pp. 140-148 ◽  
Author(s):  
A. Ouelhadj ◽  
L. Ait Salem ◽  
D. Djenane
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Nous Avons ◽  
Activité Antibactérienne

Ce travail vise l’étude de l’activité antibactérienne de l’huile essentielle (HE) de Pelargoniumx asperum et de la bactériocine, la nisine seul et en combinaison vis-à-vis de six bactéries dont quatre sont multirésistantes d’origine clinique. L’activité antibactérienne in vitro a été évaluée par la méthode de diffusion sur gélose. La concentration minimale inhibitrice (CMI) est aussi déterminée pour HE. Les résultats ont révélé une activité antibactérienne significative exercée par HE visà-vis de Staphylococcus aureus (ATCC 43300), Staphylococcus aureus et Escherichia coli avec des diamètres d’inhibition de 36,00 ; 22,50 et 40,00 mm, respectivement. Cependant, l’HE de Pelargonium asperum a montré une activité antibactérienne supérieure par rapport à la nisine. Les valeurs des CMI rapportées dans cette étude sont comprises entre 1,98–3,96 μl/ml. Les combinaisons réalisées entre HE et la nisine ont montré un effet additif vis-à-vis de Escherichia coli (ATCC 25922) avec (50 % HE Pelargonium asperum + 50 % nisine). Par contre, nous avons enregistré une synergie vis-à-vis de Klebsiella pneumoniae avec (75 % HE Pelargonium asperum + 25 % nisine) et contre Pseudomonas aeruginosa avec les trois combinaisons testées. Les résultats obtenus permettent de dire que l’HE de Pelargonium asperum possède une activité antibactérienne ainsi que sa combinaison avec la nisine pourrait représenter une bonne alternative pour la lutte contre l’antibiorésistance.

Modified Assay Medium for the Turbidimetric Assay of Chlortetracycline in Feeds

1976 ◽  
Vol 59 (3) ◽  
pp. 536-539
Author(s):  
Hussein S Ragheb
Keyword(s):  
Growth Rate ◽  
Excellent Agreement ◽  
Test Organism ◽  
Plate Method ◽  
Assay Sensitivity ◽  
Assay Medium ◽  
Turbidimetric Method ◽  
Turbidimetric Assay ◽  
Commercial Feeds ◽  
Lower Recovery

Abstract In previous experiments, the turbidimetric method for determining chlortetracycline-HCI (CTC-HCl) in feeds showed lower recovery than the AOAC plate method. Although the addition of vitamins to the turbidimetric medium improved results, values by the turbidimetric method remained about 10% lower than by the plate method. A modified (1.7 × the weight recommended by the manufacturer) turbidimetric assay medium decreased assay sensitivity but did not significantly change the slope of S. aureus response to CTC-HCl. There was no evidence that vitamin fortification of the modified medium had any significant effect on the growth rate of test organism. Examination of about 100 samples of commercial feeds containing CTC-HCl showed excellent agreement in results between the turbidimetric and plate methods.

Recovery efficiency of two glove-sampling methods

2021 ◽  
pp. 1-3
Author(s):  
Amanda K. Lyons ◽  
Laura J. Rose ◽  
Judith Noble-Wang
Keyword(s):  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Sampling Methods ◽  
Recovery Efficiency ◽  
Methicillin Resistant

Abstract Two methods to sample pathogens from gloved hands were compared: direct imprint onto agar and a sponge-wipe method. The sponge method was significantly better at recovering Clostridiodes difficile spores, and no difference was observed between the methods at 101 inoculum for carbapenemase-producing KPC+ Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii.

scholarly journals Atividade antibacteriana de extratos de folhas de Montrichardia linifera (Arruda) Schott (Araceae)

2015 ◽  
Vol 17 (4 suppl 3) ◽  
pp. 1142-1149 ◽  
Author(s):  
J.A.L MIRANDA ◽  
J.A. ROCHA ◽  
K.M. ARAÚJO ◽  
P.V. QUELEMES ◽  
S.J. MAYO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Staphylococcus Epidermidis

RESUMO O uso de plantas medicinais no tratamento de doenças é uma estratégia antiga utilizada por praticamente todas as populações do mundo, e, embora novos antibióticos tenham sido desenvolvidos para o controle de micro-organismos infecciosos, às vezes são ineficazes. Diversos extratos de plantas medicinais têm efeitos antimicrobianos, principalmente quando associados à antibióticos de uso clínico, representando alternativa terapêutica para doenças infecciosas. Montrichardia linifera, conhecida popularmente como aninga, é espécie macrófita, aquática emergente de hábito herbáceo, pertencente a família Araceae e ocorre em áreas alagáveis. A utilidade farmacológica desta espécie é diversificada tendo sido relatada como cicatrizante, antirreumático, antidiurético e expectorante. Devido à relevância no campo etnofarmacológico, ampla utilização na medicina popular e escassez de trabalhos relacionados à atividade antibacteriana desta espécie, objetivou-se com este trabalho avaliar a atividade antibacteriana de extratos alcoólicos de folhas de Montrichardia linifera, coletadas na margem do rio Igaraçu, Parnaíba-PI. O extrato foi testado em oito cepas de bactérias: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae e Pseudomonas aeruginosa. Foram utilizadas as técnicas de verificação da formação de halos de inibição e determinação das concentrações inibitórias e bactericidas mínimas. Os testes antibacterianos evidenciaram como principais resultados que o extrato metanólico seco (EMS), extrato metanólico fresco (EMF), e o extrato etanólico seco (EES), apresentaram ação antibacteriana, enquanto o extrato etanólico fresco (EEF) não apresentou atividade para as bactérias testadas. O EMS foi o mais eficiente, inibindo o crescimento bacteriano na concentração de 200 μg/mL para E. faecalis, 400 μg/mL para S. aureus, 400 μg/mL para S. epidermidis e 2.000 μg/mL para P. aeruginosa. O EMF obteve CIM de 2.000 μg/mL para E. faecalis e EES obteve CIM de 250 μg/mL para E. faecalis. Os resultados demonstraram que M. linifera constitui fonte eficiente de compostos bioativos antibacterianos. Os estudos sobre as propriedades farmacológicas de plantas da família Araceae são escassos, e os resultados deste trabalho são pioneiros em relação a atividade antibacteriana desta espécie.

scholarly journals Contaminación con bacterias patógenas de estetoscopios del personal médico en un hospital de nivel III en Lima, Perú

2016 ◽  
Vol 27 (2) ◽  
pp. 83 ◽  
Author(s):  
José Enrique Oliva-Menacho ◽  
Marco Antonio García-Hjarles ◽  
José Arturo Oliva-Candela ◽  
Hugo Saturnino De la Cruz-Roca
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Enterobacter Aerogenes ◽  
Macconkey Agar ◽  
Acinetobacter Spp ◽  
Staphylococcus Spp ◽  
Hospital General

Objetivos: Determinar el grado de contaminación bacteriana con bacterias patógenas de los estetoscopios del personal médico en un hospital general de Lima, Perú. Material y métodos: Estudio de tipo observacional, descriptivo y transversal, realizado en el Hospital Nacional Arzobispo Loayza, entre los meses de enero y juniodel 2013. Se estudiaron 124 muestras de estetoscopios del personal médico en las siguientes áreas: UCI 20; neonatología 13; quemados 3; medicina 52; emergencia 36. Se recolectaron las muestras con hisopos humedecidos, en condiciones estériles (En presencia de un mechero de vidrio para alcohol) y luego fueron introducidos en tuboscon preparado de caldo BHI (Infusión cerebro corazón) para ser incubados por 24 horas a 37°C; se cultivó en Agar sangre, Agar MacConkey, Agar manitol y Agar cetrimidepara su posterior determinación de bacterias patógenas por procedimientos bioquímicos ,luego se identificó la susceptibilidad bacteriana con la técnica de Kirby- Bauer. Resultados: De los 124 estetoscopios estudiados; 114 (91,9%) estuvieron contaminados; se aislaron 123 cepasbacterianas: Staphylococcus spp coagulasa negativa 106(86,1%), Staphylococcus aureus 5(4,0%), Enterobacter aerogenes 4 (3,2%), Acinetobacter spp 2(1,6%), Pseudomonas aeruginosa 4(3,2%), Klebsiella Pneumoniae 1(0,8%) y Escherichia coli 1(0,8%). Conclusiones: El aislamiento de bacterias patógenas sugiere que el estetoscopio debe ser considerado como un vector de la infección nosocomial.

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