Microbiological analysis of milk unfermented kefir produced with milk contaminated by Escherichia coli

2014 ◽  
Vol 5 (1) ◽  
pp. 33
Author(s):  
Danúbia R Caetano ◽  
Maike Taís Maziero Montanhini
Keyword(s):  
Escherichia Coli ◽  
Dairy Product ◽  
Fermented Milk ◽  
Microbiological Analysis ◽  
Pathogenic Microorganisms ◽  
Standard Strain ◽  
E Coli ◽  
Peptone Water ◽  
Kefir Grains ◽  
Lactic Bacteria

<p><em>The fermented milk by kefir grains is a probiotic dairy product that provides to the consumer several health benefits, and can also be consumed by lactose intolerant people. These grains contain in their microbiota acid-lactic bacteria able to inhibit the growth of pathogenic microorganisms. This research aimed to evaluate the </em>Escherichia coli<em> inhibition by the kefir fermentation, contaminated during its manufacturing. Thus, were used the standard strain ATCC 11229 </em>E. coli<em>, inoculated in the milk for the kefir production. After the fermentation, the sample were diluted in peptone water and plated in Petrifilm, followed by incubation at 36 &deg;C for 24 hours. In all repetitions, were observed at the end that the kefir fermentation did not inhibit the multiplication of the contaminant bacteria. The results reinforce the importance of the use of milk with quality, and to follow the hygiene proceedings in both utensils and manipulators, during the kefir production.</em></p><p>DOI: 10.14685/rebrapa.v5i1.158</p><p>&nbsp;</p><p>&nbsp;</p>

Prevention of Infections Produced by Escherichia coli and Listeria monocytogenes by Feeding Milk Fermented With Lactobacilli

1993 ◽  
Vol 56 (5) ◽  
pp. 401-405 ◽  
Author(s):  
MARIA ELENA NADER DE MACÍAS ◽  
NORA C. ROMERO ◽  
MARÍA CRISTINA APELLA ◽  
SILVIA N. GONZÁLEZ ◽  
GUILLERMO OLIVER
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Survival Rate ◽  
Lactobacillus Acidophilus ◽  
Lactobacillus Casei ◽  
Fermented Milk ◽  
Pathogenic Microorganisms ◽  
E Coli ◽  
Prevention Of Infections ◽  
Set Up

Challenge studies were set up feeding Lactobacillus casei and Lactobacillus acidophilus fermented milk and two different pathogenic microorganisms: Listeria monocytogenes and enteroinvasive Escherichia coli. Mice were fed for 8 consecutive days with fermented milk and then challenged with the pathogens. The survival rate in control mice was 62% for Listeria and 83% for E. coli, while 100% protection was observed for the 20 d per vial in treated mice. Colonization of the liver and spleen by E. coli was markedly inhibited by pretreatment with fermented milk; the pathogen was not detected on the 5th day postchallenge. In the Listeria challenged mice, the pathogen was present in 1 to 2 log units lower than control up the 10th day. The levels of antipathogen sera and intestinal antibodies were 2 to 4 times higher in the treated mice, with lower values in the Listeria treated mice. The mechanism of protection in both types of infections was discussed. The results obtained suggested that milk fermented with L. casei and L. acidophilus could be used as a prophylactic against selected infections.

Contamination of Intact Apples after Immersion in an Aqueous Environment Containing Escherichia coli O157:H7†

1999 ◽  
Vol 62 (5) ◽  
pp. 444-450 ◽  
Author(s):  
R. L. BUCHANAN ◽  
S. G. EDELSON ◽  
R. L. MILLER ◽  
G. M. SAPERS
Keyword(s):  
Escherichia Coli ◽  
Outer Core ◽  
Core Region ◽  
Effect Of Temperature ◽  
Aqueous Environment ◽  
Escherichia Coli O157 ◽  
Dye Uptake ◽  
E Coli ◽  
Golden Delicious ◽  
Peptone Water

The extent and location of Escherichia coli O157:H7 contamination after intact apples were immersed in cold (2°C) 1% peptone water containing approximately 3 × 107 CFU/ml was assessed using four apple varieties, Golden Delicious, McIntosh, Red Delicious, and Braeburn. Room temperature and refrigerated apples were used to determine the effect of temperature differential on E. coli infiltration. The highest levels of E. coli were associated with the outer core region of the apple, followed by the skin. Apples were subsequently treated by immersing them for 1 min in 2,000 mg/liter sodium hypochlorite, followed by a 1-min tapwater rinse. This treatment reduced pathogen levels by 1- to 3-log cycles but did not eliminate the microorganism, particularly from the outer core region. While E. coli was not detected in the inner core of most apples, warm fruit immersed in cold peptone water occasionally internalized the pathogen. The frequency and extent of internalization of the pathogen was less when cold apples were immersed in cold peptone water. Subsequent dye uptake studies with Golden Delicious apples indicated that approximately 6% of warm apples immersed into a cold dye solution accumulated dye via open channels leading from the blossom end into the core region. However, dye uptake did not occur when the dye solution was warmer than the apple.

scholarly journals Escherichia coli is not a suitable fecal indicator to assess water fecal contamination by otters

2017 ◽  
Vol 78 (1) ◽  
pp. 155-159 ◽  
Author(s):  
M. Oliveira ◽  
D. Freire ◽  
N. M. Pedroso
Keyword(s):  
Escherichia Coli ◽  
Fecal Contamination ◽  
Microbiological Quality ◽  
Aquatic Environments ◽  
Pathogenic Microorganisms ◽  
Fecal Indicator ◽  
Fecal Samples ◽  
E Coli ◽  
Paulo State

Abstract The detection of pathogenic microorganisms in aquatic environments is extremely relevant in terms of public health. As these laboratorial methodologies are usually difficult, expensive and time-consuming, they are frequently replaced by the assessment of fecal indicator bacteria, such as Escherichia coli. This study aimed to assess the presence of E. coli in fecal samples from Neotropical otters, to evaluate its potential as fecal indicator to be applied to the determination of water microbiological quality in areas where otters’ populations are high. Twenty-six otter fecal samples, collected in Alto Paranapanema river basin, São Paulo State, Brazil, were analyzed for the presence of E. coli, using conventional bacteriological methods. Only 8 scat samples (30%) were E. coli positive, indicating that this microorganism is not a suitable fecal indicator to assess water fecal contamination by Neotropical otters, and should not be used to infer the presence of otter related pathogens in waters.

Predicting the Behavior of Escherichia coli Introduced as a Postprocessing Contaminant in Shrikhand, a Traditional Sweetened Lactic Fermented Milk Product

2001 ◽  
Vol 64 (4) ◽  
pp. 462-469 ◽  
Author(s):  
A. JAGANNATH ◽  
M. N. RAMESH ◽  
M. C. VARADARAJ
Keyword(s):  
Escherichia Coli ◽  
Response Surface ◽  
Storage Period ◽  
Fermented Milk ◽  
Behavioral Pattern ◽  
Milk Product ◽  
Initial Inoculum ◽  
E Coli ◽  
And Storage ◽  
Fermented Milk Product

The increasing popularity of traditional milk-based foods has placed emphasis on the need for microbial safety in food-chain establishments, as there are ample possibilities for foodborne pathogens to occur as postprocessing contaminants. The behavioral pattern of an enterotoxigenic strain of Escherichia coli D 21 introduced as a postprocessing contaminant in shrikhand, a traditional sweetened lactic fermented milk product, was studied with variables of initial inoculum (4.3, 5.3, and 6.3 log10 CFU/g), storage temperature (4, 10, and 16°C), and storage period (4, 9, and 14 days). During storage of shrikhand prepared individually with Lactobacillus delbruecki ssp. bulgaricus CFR 2028 and Lactococcus lactis ssp. cremoris B-634, there was a steady decrease in the viable count of E. coli that was proportional to the initial inoculum of E. coli introduced into shrikhand. The data were subjected to multivariate analysis, and equations were derived to predict the behavior of E. coli in shrikhand. The predicted values for the probable survival of E. coli showed good agreement with the experimental values with a majority of these predictions being fail-safe. The values of statistical indices showed that the model fits ranged between extremely good and satisfactory. Response surface plots were generated to describe the behavioral pattern of E. coli. The derived models and response surface plots enabled prediction of the survival of E. coli in shrikhand as a function of initial inoculum levels, storage temperatures, and storage periods of shrikhand. These predictions were valid within the limits of the experimental variables used to develop the model.

Simultaneous Enrichment of Shiga Toxin–Producing Escherichia coli O157 and O26 and Salmonella in Food Samples Using Universal Preenrichment Broth

2009 ◽  
Vol 72 (10) ◽  
pp. 2065-2070 ◽  
Author(s):  
MASASHI KANKI ◽  
KAZUKO SETO ◽  
JUNKO SAKATA ◽  
TETSUYA HARADA ◽  
YUKO KUMEDA
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Food Samples ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Significant Difference ◽  
Peptone Water ◽  
Radish Sprouts ◽  
Pork Samples ◽  
Better Than

Universal preenrichment broth (UPB) was compared with modified Escherichia coli broth with novobiocin (mEC+n) for enrichment of Shiga toxin–producing E. coli O157 and O26, and with buffered peptone water (BPW) for preenrichment of Salmonella enterica. Ten strains each of the three pathogens were inoculated into beef and radish sprouts following thermal, freezing, or no treatment. With regard to O157 and O26, UPB incubated at 42°C recovered significantly more cells from inoculated beef than UPB at 35°C and from radish sprout samples than UPB at 35°C and mEC+n. With regard to Salmonella, UPB incubated at 42°C was as effective as UPB at 35°C and BPW at recovering cells from beef and radish sprout samples. No significant difference was noted between the effectiveness of UPB at 42°C and UPB at 35°C or BPW in the recovery of Salmonella from 205 naturally contaminated poultry samples. By using UPB at 42°C, one O157:H7 strain was isolated from the mixed offal of 53 beef samples, 6 cattle offal samples, and 50 pork samples all contaminated naturally, with no pathogen inoculation. The present study found that UPB incubated at 42°C was as effective as, or better than, mEC+n for enrichment of O157 and O26 and comparable to BPW for preenrichment of Salmonella. These findings suggest that a great deal of labor, time, samples, and space may be saved if O157, O26, and Salmonella are enriched simultaneously with UPB at 42°C.

scholarly journals Performance evaluation of combined ultraviolet-ultrasonic technologies in removal of sulfonamide and tetracycline resistant Escherichia coli from domestic effluents

2020 ◽  
Vol 10 (2) ◽  
pp. 276-285 ◽  
Author(s):  
Owassa Dza Rebecca Annisha ◽  
Zifu Li ◽  
Xiaoqin Zhou ◽  
Ngomah Madgil Don Stenay ◽  
Oscar Omondi Donde
Keyword(s):  
Escherichia Coli ◽  
Ultraviolet Radiation ◽  
Continuous Operation ◽  
Pathogenic Microorganisms ◽  
Wastewater Purification ◽  
Antibiotic Resistant ◽  
Radiation Technology ◽  
E Coli ◽  
The Mean ◽  
Domestic Effluents

Abstract Proper treatment of wastewater is key to the achievement of sustainable environmental management. The use of ultraviolet radiation and ultrasound have continued to be considered as some of the best sustainable practices in wastewater purification. However, despite the suitability of the two emerging techniques in sustainably increasing the purification efficiencies of wastewater, their application has not been fully understood, especially in eliminating faecal pathogenic microorganisms. Moreover, their combined potential in the elimination of Escherichia coli resistant genes from wastewater has not been adequately explored. This study was designed to evaluate the potential of individual and combined/integrated ultraviolet radiation and ultrasonic technologies in the removal of antibiotic-resistant E. coli from domestic effluents. There was a statistical difference in the mean log units of sulfonamide resistant E. coli between the different ultraviolet radiation and ultrasonic dosages (P &lt; 0.05), showing that ultraviolet radiation technology was more effective in the removal of both sulfonamide and tetracycline resistant E. coli from the wastewater. However, the integrated ultraviolet radiation-ultrasonic technique was highly efficient and is recommended in the removal of antibiotic resistant E. coli from wastewater. Nonetheless, further studies also need to be performed to further evaluate the disinfection effectiveness on a different bacteria species under continuous operation.

Inhibitory Activity of Cheese Whey Fermented with Kefir Grains

2011 ◽  
Vol 74 (1) ◽  
pp. 94-100 ◽  
Author(s):  
A. LONDERO ◽  
R. QUINTA ◽  
A. G. ABRAHAM ◽  
R. SERENO ◽  
G. DE ANTONI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Acid Production ◽  
Cheese Whey ◽  
Lactic Acid Production ◽  
Reaction Products ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Fermentation Products ◽  
E Coli ◽  
Kefir Grains

We investigated the chemical and microbiological compositions of three types of whey to be used for kefir fermentation as well as the inhibitory capacity of their subsequent fermentation products against 100 Salmonella sp. and 100 Escherichia coli pathogenic isolates. All the wheys after fermentation with 10% (wt/vol) kefir grains showed inhibition against all 200 isolates. The content of lactic acid bacteria in fermented whey ranged from 1.04 × 107 to 1.17 × 107 CFU/ml and the level of yeasts from 2.05 × 106 to 4.23 × 106 CFU/ml. The main changes in the chemical composition during fermentation were a decrease in lactose content by 41 to 48% along with a corresponding lactic acid production to a final level of 0.84 to 1.20% of the total reaction products. The MIC was a 30% dilution of the fermentation products for most of the isolates, while the MBC varied between 40 and 70%, depending on the isolate. The pathogenic isolates Salmonella enterica serovar Enteritidis 2713 and E. coli 2710 in the fermented whey lost their viability after 2 to 7 h of incubation. When pathogens were deliberately inoculated into whey before fermentation, the CFU were reduced by 2 log cycles for E. coli and 4 log cycles for Salmonella sp. after 24 h of incubation. The inhibition was mainly related to lactic acid production. This work demonstrated the possibility of using kefir grains to ferment an industrial by-product in order to obtain a natural acidic preparation with strong bacterial inhibitory properties that also contains potentially probiotic microorganisms.

scholarly journals Long-Term Persistence and Leaching of Escherichia coli in Temperate Maritime Soils

2009 ◽  
Vol 76 (5) ◽  
pp. 1449-1455 ◽  
Author(s):  
Fiona P. Brennan ◽  
Vincent O'Flaherty ◽  
Gaelene Kramers ◽  
Jim Grant ◽  
Karl G. Richards
Keyword(s):  
Escherichia Coli ◽  
Soil Type ◽  
Preferential Flow ◽  
Pathogenic Microorganisms ◽  
E Coli ◽  
Natural Rainfall ◽  
Lysimeter Experiment ◽  
Effect Of Treatment

ABSTRACT Enteropathogen contamination of groundwater, including potable water sources, is a global concern. The spreading on land of animal slurries and manures, which can contain a broad range of pathogenic microorganisms, is considered a major contributor to this contamination. Some of the pathogenic microorganisms applied to soil have been observed to leach through the soil into groundwater, which poses a risk to public health. There is a critical need, therefore, for characterization of pathogen movement through the vadose zone for assessment of the risk to groundwater quality due to agricultural activities. A lysimeter experiment was performed to investigate the effect of soil type and condition on the fate and transport of potential bacterial pathogens, using Escherichia coli as a marker, in four Irish soils (n = 9). Cattle slurry (34 tonnes per ha) was spread on intact soil monoliths (depth, 1 m; diameter, 0.6 m) in the spring and summer. No effect of treatment or the initial soil moisture on the E. coli that leached from the soil was observed. Leaching of E. coli was observed predominantly from one soil type (average, 1.11 � 0.77 CFU ml−1), a poorly drained Luvic Stagnosol, under natural rainfall conditions, and preferential flow was an important transport mechanism. E. coli was found to have persisted in control soils for more than 9 years, indicating that autochthonous E. coli populations are capable of becoming naturalized in the low-temperature environments of temperate maritime soils and that they can move through soil. This may compromise the use of E. coli as an indicator of fecal pollution of waters in these regions.

COMPARISON OF MICROBIOLOGICAL QUALITY OF MILK PRODUCTS FROM ORGANIC AND CONVENTIONAL PRODUCTION

2018 ◽  
Vol XX (6) ◽  
pp. 147-153
Author(s):  
Anita Kukułowicz
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Dairy Product ◽  
Microbiological Quality ◽  
Organic Production ◽  
Microbiological Analysis ◽  
Milk Products ◽  
Significant Difference ◽  
Conventional Production

The aim of the research was to compare the microbiological quality of dairy products derived from organic and conventional farming. The test material consisted of milk and milk products (natural yoghurt, cream, curd cheese, rennet ripening cheese, milk). Investigated products were subjected to microbiological analysis and marked for the number of Enterococcus sp., Staphylococcus aureus, yeast and moulds, Escherichia coli as well as to state the presence of Salmonella sp. in them. All samples were free of Salmonella sp. Escherichia coli occurred in 2 samples of curd cheese from organic production. Products derived from organic and conventional production didn’t differ in the average number of microorganisms depending on the type of dairy product, with the exception of ripening rennet cheese, which showed a significant difference in the amount of Staphylococcus aureus.

Microbiologia de Linguiças Caseiras in natura, Refrigeradas, Assadas e Congeladas

2019 ◽  
Vol 23 (1) ◽  
pp. 67
Author(s):  
Lourena Paz Soares Nunes ◽  
Francisco Das Chagas Cardoso Filho ◽  
Mikaela Lopes de Caldas ◽  
Lidiane Mota Martins ◽  
Lailana Da Paz Soares Santos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
National Standards ◽  
Food Microbiology ◽  
The Other ◽  
Pathogenic Microorganisms ◽  
Microbiology Laboratory ◽  
Pork Sausage ◽  
E Coli ◽  
Sanitary Conditions ◽  
Butcher Shops

A linguiça caseira é bem aceita e comercializada em todo Brasil. Mesmo pronta para o consumo, pode apresentar alguns micro-organismos patogênicos, caracterizando possível falha no seu controle higiênico-sanitário. Este trabalho teve como objetivo averiguar as condições higiênicas e sanitárias em linguiças caseiras comercializadas em Teresina, PI, e verificar as temperaturas necessárias para inativação da microbiota existente nas linguiças. Foram utilizados dez açougues de Teresina-PI, que comercializam linguiça suína caseira, recolhendo-se amostras de 400 gramas de cada e as transportando até o Laboratório de Microbiologia de Alimentos do NUEPPA/CCA/UFPI, no qual se realizaram as seguintes análises: bactérias heterotróficas mesófilas, psicrófilas, coliformes a 37 ºC  e E. coli. As linguiças caseiras analisadas estavam de acordo com os padrões nacionais vigentes, sendo que para E.coli 10,0% das amostras apresentaram valores elevados, porém  não existe parâmetro para essa bactéria. Conclui-se que a linguiça "in natura" obteve os maiores índices de coliformes, E. coli, mesófilas e psicrófilas com relação aos demais tratamentos. A refrigeração doméstica não inibiu o crescimento de coliformes, E. coli, mesófilas e psicrófilas. A cocção reduz as contagens bacteriológicas, entretanto, não inativava as bactérias. O congelamento por seis meses, inativa a E.coli e as psicrófilas e reduz a contagem de mesófilas e coliformes. Palavras-chave: Coliformes. Escherichia coli. Mesófilos. Psicrófilos. AbstratHomemade sausage is well accepted and sold in Brazil. Even ready for consumption, can present some pathogenic microorganisms, characterizing possible failure in its hygienic-sanitary control. This study aimed to investigate the hygienic and sanitary conditions in homemade sausages commercialized in Teresina, PI, and check the temperatures required to inactivate the existing microbiota in sausages. 10 butcher shops were used  in Teresina-PI that sell homemade pork sausage, collecting samples of 400 grams each and transported to the Food Microbiology Laboratory of NUEPPA / CCA / UFPI, where the following analysis was held: heterotrophic mesophilic bacteria, psichrophilic, coliforms at 37 ºC and E. coli. The homemade sausages were analyzed according to agreed national standards, and for E.coli 10.0% of the samples showed high values, however  there is no parameter for this bacterium.  The  sausage "in natura" achieved the highest levels of coliforms, E. coli, mesophilic and psichrophilic with the other treatments. The domestic refrigeration did not inhibit the growth of coliforms, E. coli and mesophilic psichrophilic. The cooking reduces bacterial counts, though it does not inactive the bacteria. The six-month period freezing inactivates  E.coli and psichrophilic and reduces the mesophilic and coliform count. Keywords: Coliforms. Escherichia Coli. Mesophilic. Psychrophiles

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