scholarly journals Comparison of Optimal Storage Temperature and Collection Reagents for Living Bacterial Cells in Swab Samples

2021 ◽  
Vol 53 (4) ◽  
pp. 326-332
Author(s):  
Yeong Ju Lee ◽  
Hee Sang You ◽  
Song Hee Lee ◽  
So Lip Lee ◽  
Han Lee ◽  
...  
2017 ◽  
Vol 40 (2) ◽  
pp. 66-72
Author(s):  
Najim Hadi Najim

     Isolates of Enterohaemorrhagic E.coli O157:H7 were isolated from 51 and 41 of locally produced bovine and ovine soft cheese samples. Their identification were confirmed based on the biochemical reactions and both the morphological cultural and serological properties. Presumptive E.coli O157:H7 isolates obtained by using the conventional selective plating on the chromogenic agar were tested further for the presence of both O157 and H7 antigenes using the latex agglutination test antisera. The current microbiological studies revealed that 31 (33.70 %) out of 92 bovine and ovine soft cheese samples were positive for E.coli O157:H7. The highest non significant (P>0.05) prevalence level of E.coli O157:H7 was found in the ewe᾿s soft cheese samples (36.59 %) followed by cow᾿s soft cheese samples (31.37 %). Agar well diffusion bioassay method was used for measuring the antibacterial activity of the crude bacteriocin that was produced by Lactobacillus rhamnosus GG-ATCC against Escherichia coli and the closely related sensitive strains such as L.acidophilus LA-K and L.acidophilus ROO52. The crude bacteriocin that was produced by the L.rhamnosus GG-TACC exhibited significantly (P<0.05) the highest antibacterial potency (100 %) against both the closely related strains of lactobacilli and the stressed E.coli O157:H7 by the activation of the LPS. The activation of the natural LPS of inoculated pasteurized milk had significantly (P<0.05) influenced the inactivation degree of the crude bacteriocin against E.coli O157:H7. There was a significant (P<0.05) reduction in the viable counts of stressed E.coli O157:H7 after each exposure time period (6, 24 and 48 hrs.) to the crude bacteriocin at room storage temperature. An overall conclusion on the basis of the current results pointed  out  that complete  elimination of viable bacterial cells was not achieved  neither  in  the stabilized milk (Activation of LPS) nor after  subjecting  the stabilized  milk to the action of the crude bacteriocin produced by L.rhamnosus GG-ATCC at room storage temperature.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Justyna Nasiłowska ◽  
Barbara Sokołowska ◽  
Monika Fonberg-Broczek

Food business operators search for new, mild technologies, which extend the shelf life of product without changing the sensory and nutritional properties. High hydrostatic pressure (HHP) meets these requirements; however it also triggers sublethal injury of bacterial cells. Sublethal injuries could spoil the product during storage and potentially pose major public health concerns. This study aims to examine the changes of sublethally injured pathogens cells in two vegetable juices: carrot juice (pH 6.0-6.7) and beetroot juice (pH 4.0-4.2) that are induced by HHP (300-500 MPa). The possibilities of recovery of bacterial cells during 28 days of juices storage at two different temperatures (5°C and 25°C) were determined using plate count methods. During the entire period of storage of carrot juice at refrigerated temperature, the propagation and regeneration ofL. innocuastrains were observed. Storage at 25°C showed that the number of these bacteria drastically decreased between 14 and 21 days. The above phenomenon was not detected inE. colicase. There was no cells recovery during long-term refrigerated storage for all strains in beetroot juice. However, in some cases spoiling of this product intermittently occurred at 25°C storage temperature. This work demonstrates that carrot juice supports growth and regeneration of HHP-sublethally injuredL. innocua, while beetroot juice can be classified as a safe product.


2019 ◽  
pp. 278-285
Author(s):  
Meta Sternisa ◽  
Mihael Cargo ◽  
Sonja Smole-Mozina

Microbial growth and metabolism in food leads to organoleptic spoilage through altering colour, odour and texture of food, and slime or liquid production on the surface. In the dynamics of organoleptic spoilage, initial microbial contamination and storage temperature of food play an important role. Bacteria Pseudomonas are known as the most common spoilage bacteria. Aim of this study was to evaluate the ability of selected Pseudomonas strains to grow at 5?C in different food models, and to evaluate their spoilage potential as the ability to produce different hydrolytic enzymes at 5?C. This was determined through monitoring the number of bacterial cells in food models at 5?C, over 9 days of incubation, and on agars for detection of proteolytic and lipolytic activity. Of the four selected Pseudomonas strains (P. fragi CC151, P. fragi CC275, P. psychrophila CC291, P. lactis CC194), all were capable of producing lipolytic and proteolytic enzymes. When monitoring Pseudomonas growth in different food models (minced meat, pasteurized milk, apples) as compared to broth, the best growth was achieved in minced meat model, and the lowest in apple model. Thereby, the importance of the nutrients availability and the use of hydrolytic enzymes to exploit more complex nutrient molecules, especially proteins, has been confirmed. Selected Pseudomonas strains are able to grow in a variety of food media, and have the ability to produce hydrolytic enzymes, confirming their universality as refrigerated food spoilers, with high potential of persisting in the food storage environment.


Author(s):  
C. M. Turley ◽  
D. J. Hughes

Rates of decrease in epifluorescence-detectable bacteria in preserved sea-water samples changed significantly with temperature. This apparent cell loss was substantial even in preserved samples stored in a refrigerator, decreasing exponentially with time, with 56% apparent cell loss after 99 days’ storage. Storage at room temperature resulted in the greatest decrease in detectable cells, with 73% apparent cell loss after the same storage period. No significant difference was found between storage in two different containers. The apparent cell loss can be modelled in order to calculate the original cell numbers with confidence. However, models produced from one set of samples cannot be applied to the data from another.


Author(s):  
G.E. Ananina ◽  
L.V. Stepanyuk ◽  
I.P. Vysekantsev ◽  
I.V. Petrov

Dysbiosis is among the challenges the healthcare is facing now. This condition results from to the combined impact of a number of negative factors on the human body, and immune status weakening. The priority of current biotechnology is the elaboration of probiotics immobilized in gel particles that can be used to correct dysbiosis. Immobilization of probiotic cells in alginate gel granules protects them from the damaging effects of barrier functions of the gastrointestinal tract. The aim of the study was to investigate the effect of hypothermic and low-temperature storage on the viability of the probiotic Bifidobacterium bifidum immobilized in granules of alginate gel. Bacterial cells were immobilized in granules of unmodified gel (1% sodium alginate solution) and in granules of modified sucrose-milk-lactose gel. Granules with immobilized bacterial cells were placed into cryotubes. The samples kept at temperatures of +4, -12, -20, -80 and -196 ° C for 12 months (study period). It was found that storage at temperatures -80 and -196°C provided high viability of the probiotic throughout the study. During storage at temperatures of +4 and -12 ° C, the death of bacteria was observed in 1 – 3 months, depending on the composition of the gel particles, and at a temperature of -20°C the death occurs in 6-9 months. Conclusions: It has been established that the viability of B. bifidum culture cells immobilized in alginate gel granules is influenced by both storage temperature modes and gel modification by the introduction of sucrose-milk-lactose medium. At temperature ragnes of -80 and -196°C, immobilized bacteria do not die during the year (observation period). When storing at the temperatures +4, -12, -20°C, higher viability rates and longer shelf life of bifidobacterial cells were observed in samples of alginate gel granules modified with sucrose-milk-lactose medium. The study has shown that being kept at the low temperature values, B. bifida cells immobilized in unmodified and modified with sucrose-milk-lactose medium do not change their cultural and morphological properties.


Author(s):  
R. H. Liss

Piperacillip (PIP) is b-[D(-)-α-(4-ethy1-2,3-dioxo-l-piperzinylcar-bonylamino)-α-phenylacetamido]-penicillanate. The broad spectrum semisynthetic β-lactam antibiotic is believed to effect bactericidal activity through its affinity for penicillin-binding proteins (PBPs), enzymes on the bacterial cytoplasmic membrane that control elongation and septation during cell growth and division. The purpose of this study was to correlate penetration and binding of 14C-PIP in bacterial cells with drug-induced lethal changes assessed by microscopic, microbiologic and biochemical methods.The bacteria used were clinical isolates of Escherichia coli and Pseudomonas aeruginosa (Figure 1). Sensitivity to the drug was determined by serial tube dilution in Trypticase Soy Broth (BBL) at an inoculum of 104 organisms/ml; the minimum inhibitory concentration of piperacillin for both bacteria was 1 μg/ml. To assess drug binding to PBPs, the bacteria were incubated with 14C-PIP (5 μg/0.09 μCi/ml); controls, in drug-free medium.


Author(s):  
J. E. Laffoon ◽  
R. L. Anderson ◽  
J. C. Keller ◽  
C. D. Wu-Yuan

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).


1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.


2018 ◽  
Vol 5 (2) ◽  
pp. 102
Author(s):  
Enike Dwi Kusumawati ◽  
Selvinus Lawu Woli ◽  
Aju Tjatur Nugroho Krisnaningsih ◽  
Waluyo Edi Susanto ◽  
Syam Rahadi

ABSTRAKPenelitian ini dilakukan untuk mengetahui motilitas dan viabilitas spermatozoa ayam kampung pada suhu 5oC menggunakan pengencer dan lama simpan yang berbeda. Metode yang digunakan dalam penelitian ini adalah penelitian laboratorium menggunakan Rancangan Acak Lengkap (RAL) Faktorial dengan pengencer ringer lactat solution, air kelapa dan tanpa pengencer serta lama simpan 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, masing-masing diulang 10 kali. Variabel yang diamati yaitu motilitas dan viabilitas spermatozoa. Analisa data yang digunakan adalah analisis varian. Hasil analisis data menunjukkan bahwa motilitas dan viabilitas spermatozoa menggunakan pengencer ringer lactat solution lebih tinggi (P<0,01) serta dapat bertahan sampai lama simpan 24 jam dibandingkan air kelapa dan tanpa pengencer. Adapun nilai motilitas ringer lactat solution, air kelapa dan tanpa pengencer pada lama simpan 24 jam masing-masing sebesar 43,5±17,17%; 8±4,83%; 6,5±2,4%, sedangkan nilai viabilitasnya sebesar 83,2±7,25%; 64,6±3,20%; dan 63,1±2,33%. Kesimpulan dari hasil penelitian ini adalah ringer lactat solution lebih baik dibandingkan air kelapa dan tanpa pengencer dalam mempertahankan kualitas semen ayam kampung pada suhu simpan 5oC sampai lama simpan 24 jam.Kata Kunci : air kelapa, ayam kampung, motilitas, spermatozoa, viabilitas  ABSTRACTThis study was conducted to determine the motility and viability of spermatozoa of Native chickens at 5oC using different diluents and time storage. The method used in this study was laboratory research using Factorial Completely Randomized Design with ringer lactate solution, coconut water and without diluent at 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 hours of time storage each repeated 10 times. The variables observed were motility and viability of sperm. Data analysis used is variance analysis. The results of data analysis showed that the motility and viability of spermatozoa using ringer lactate solution diluents was higher (P <0.05) than coconut water and without diluents. The motility values of ringer lactat solution, coconut water and without diluents were 43,5±17,17%; 8±4,83%; 6,5±2,4% respectively, while the viability values were 83,2±7,25%; 64,6±3,20% and 63,1±2,33%. The conclusion of this study is that ringer lactat solution is better than coconut water an without diluents in maintaining the quality of Native chicken semen at a storage temperature of 5oC until 24 hours.Keywords: coconut water, motility, native chicken, sperm, viability


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