m13-linababickaite

Internship at the University of Copenhagen, Denmark

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Last weeks and achieved objectives

The last weeks have been based on writing the final protocol.

Learning objective 1:

To understand Public Health significance of occurrence and quantification of bacteria producing extended-spectrum-beta-lactamases (ESBLs) in oultry meat products. 

 This objective was achieved by reviewing:

- Existing literature. In order to understand the issue of Public Health I had to read and review articles. 

- Gathered literature will be used in final BA thesis

Learning objective 2:

to perform detection and quantification of ESBL producing bacteria in chicken meat by traditional microbiology methods

The objective was achieved by preparing selective media and processing chicken meat samples. 

Indeed, by the end of the Internship I have a strong knowledge of processing meat samples. I could defend methods I have been working on and why this method is the best.

Learning objective 3:

To perform detection and quantification of ESBL producing bacteria in chicken meat by culture-independent methods

This objective was party achieved due to:

- Lack of time

- Focused a lot on culture-dependent methods such as Enrichment and Direct Plating.

- Many samples had to be done and therefore time was not estimated properly.

- Worked on DNA extraction from liquid used to rinse chicken meat products but not on qPCR method which is also sophisticated method helping to detect bacteria in the meat.

Learning objective 4:

To evaluate pros and cons of the culture-dependent and culture-independent approaches used to detect and quantify ESBL-producing bacteria in chicken meat. 

This objective was achieved by having:

-  Discussion with supervisor 

-  Daily recording of a lab book

-  Power point presentation summarizing the work performed to be held at a group meeting at the host institution

-  Written report at the end of Internship period 

Finally I have collected my own data which I intend to use for my thesis.

This internship experience was very significant to me. I found myself here and hope to return here one day again.

I could recommend this for the future Interns if you like work at the lab :)

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7th,8th and 9th weeks

All the weeks I have been continuously working with chicken meat fillet and doing experiments . Meat purchased  was in Føtex, more in Super Brugsen and IRMA.

A higher number of bacteria is found at the meat sold at Føtex supermarket. Also after the experiments we could see that E.coli is growing on the plates containing certain antibiotic and those plates are having a higher number of contamination than others (possible due to the supermarket brand and producer). In general E.coli becomes very and very common cause of the infection which is an issue for the society. Some antibiotics are not working properly any longer meaning that bacteria is stronger than antibiotic.

There is a plan to work on chicken carcasses for the next 3 weeks and then compare the difference between chicken fillet and chicken carcasses.

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5th and 6th weeks of the Internship

2 weeks have been based more on analyzing data what we have obtained so far.

3 fillets out of 22 fillets are positive with the contamination prevalence of 14 %.

2 out of 10 packages are positive remaining 20%.

1.       Overview of the chicken meat types  sold at:

-          Irma

-          Føtex

-          Superbrugsen

-          Aldi

-          Inko (we will take this supermarket in the following weeks as we cannot go to this supermarket by ourselves)

Both for chicken fillets and whole chicken carcasses,  focus should be on the following parameters:

-          Produced in Denmark or abroad

-          Conventional or organic

-          Name of the producer

Based on point number 1, we will decide which samples we should still purchase to finalize the study.

2.       Preparation of new batches of media

-          MacConkey agar plates

-          MacConkey agar plates + cefotaxime (1 ug/ml)

-          Tubes with 10 ml MacConkey broth

-          Tubes with 10 ml MacConkey broth + cefotaxime (1 ug/ml)

3.       Processing of new samples – plan to be finalized based on point 1.

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Third and fourth weeks

In the 3rd and 4th weeks we mainly have been continuing our experiments on the chicken meat sold at supermarkets.

We purchased more chicken meat from ALDI, FØTEX and IRMA and compared the results. For us it is very important to have as many samples as we can make in order to make proper analysis.

Meat which was purchased from ALDI AND IRMA did  not have a high amount of bacteria. One argument could be that meat produced by DAMPO and ROSE has high quality standards. However, meat which was purchased in FØTEX had a higher amount of bacteria. In the meet produced by Supermarked A/S we found 38, 45, 15 and 17 E. coli bacteria. We have four different numbers because we need an average of bacteria, it would be hard to make any assumptions only having one number. Although, in this month it is the first high number which we got. 

There is also another method to check if there is any kind of bacteria in the meat. To check if meat is positive or negative we use enrichment method mainly dissolving 1 ml of meat rinse in Macconkey broth. Macconkey broth is a liquid used for growing bacteria. It is a very practical tool having low proportion of false positive reactions. In the enrichment method there is an observation that ecological meat has many pseudomonas (gram negative bacteria changing color into green, yellowish or orange). That was actually surprising that eco meat has pseudomonas, almost all experiments showed the same.

This is the meat with many found E.Coli

Could you see the numbers I, J, I+CTX, J+CTX? Those have pseudomonas, it belongs to organic meat, in enrichment method we cannot say how many bacteria it has we only say it is positive or negative. So I and J are positive having pseudomonas.

Only using direct culture method we can count bacteria.

Both methods culture and enrichment methods are appropriate however if we want to see positive or negative results we choose enrichment, if we want to know precise number of bacteria we use culture method.

Those methods might sound confusing but they are both highly acceptable in Microbiological Food Safety and of course it takes some time to understand how it works.

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Second week of Internship

So this week I already started to work on my real project. 

In second week we went to the supermarket Aldi  and bought 2 packages of chicken  fillets  (non ecological and ecological). To find out if there is any bacteria in the meat  we have performed  direct culture method. Direct culture method is used to count the number of colonies on the agar plates, more colonies the plate has higher contamination is found. To perform this experiment we used 1ml  of meat rinse together with buffered peptone water (it is a special liquid for the purposes of growing bacteria). We also named the plates A, B, C, D etc since we needed to recognize if the meat is ecological or not, we were also interested at looking if bacteria E.Coli is resistant to antibiotic called cefotaxime. we made equal amount of plates:

8 plates of non ecological meat and without antibiotic, 8 plates of non ecological meat but with antibiotic, 8 plates of eco meat without antibiotic and 8 plates of eco meat with antibiotic. in the result analysis we found that there was a higher contamination in  ecological meat and especially if there was no antibiotic. 

There will be more following experiments, based on that we will make final analysis

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First week

I am very happy about my Internship, first week was full of new things! I got familiar about my working place, food safety issues & rules at the lab. My supervisor provided all necessary information and my responsibilities here.

This week was more less introductory week where I have been doing “fake” experiments” in order for me to get more confident before start working on my real project.

This week I have been doing experiments on E. Coli bacteria, the purpose of it to count colonies (colonies are the small dots on the plates) on the agar plates  and see if the antibiotic cefotaxime is resitant to such bacteria. I have been preparing agar plates with and without antibiotic, after the experiment I could obviously see that using specific antibiotic the number of colonies are not so big. Likewise, the number of colonies are bigger if antibiotic is not used =>specific antibiotics kill specific bacteria.

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Second Internship place

I will be working in the department of Veterinary Disease Biology located in Copenhagen, Denmark.

The aim of the project is to quantify ESBL (extended-spectrum beta-lactamase, ESBL) producing bacteria in chicken meat sold in supermarkets and know the exposure of consumers to such bacteria. ESBL producers are bacteria that produce an enzyme (extended-spectrum beta-lactamase, ESBL) that inactivate cephalosporins, which are very important antibiotics for treating infections in humans.

In this project, we will go to different supermarkets and purchase either chicken breast or whole chicken carcasses, we will rinse them and we will use the rinsing liquid for the experiments.

The work will take place at the lab for 12 weeks and data collection will be later used in the final BA thesis.

I have been particularly interested in Microbiological Food Safety area and this place is exactly what I have been seeking. I also have some experience working at the lab so it gives me a better understanding.