Comparative Test on the Level Contamination of Escherichia coli and Salmonella sp. on Broiler Meat at Slaughterhouses and Traditional Markets in Medan

. Contamination of meat is common Contamination of meat often occurs which endangers the health of consumers. This study aims to determine the presence of bacterial contamination of Escherichia coli and Salmonella sp . on broiler meat at slaughterhouses and traditional markets in Medan City. This study used a survey method with a purposive sampling technique and used 60 samples (30 from slaughterhouses and 30 from traditional markets). There were 3 slaughterhouses (slaughterhouses Johor, slaughterhouses setia budi, and slaughterhouses padang bulan) and three traditional markets (traditional market Johor, Setia Budi and Padang bulan). Samples were analyzed at the Laboratory Microbiology Faculty of Mathematic and Natural Science Universitas Sumatera Utara Medan. The results showed that the average total amount of Escherichia coli in the sample from chicken slaughterhouses was 3.15 log CFU/g, and from the traditional markets was 3.39 log CFU/g. The number of samples contaminated by Salmonella sp. in chicken slaughterhouses was 17 of 30 samples, whereas on the traditional market were 20 of the 30 samples. This study concludes that the average total amount of Escherichia coli microbes in samples from chicken slaughterhouses and traditional markets in Medan City all of them had exceeded the maximum limit of microbial contamination, based on the microbiological quality requirements of SNI 3932: 2008, which is 1x10 1 CFU/g. While the bacterial contamination rate of Salmonella sp. in chicken slaughterhouses was 56%, and in the traditional market was 66%.


Introduction
Chicken meat is a popular food source for the community. This fact is accompanied by the large amount of chicken meat consumed by the people of Indonesia, which is 0.538 kilos/per capita/month and continues to increase based on a survey by the Central Statistics Agency (BPS).
Chicken meat is a livestock product with properties and characteristics that are very sensitive to damage due to contamination [1]. Chicken meat is a food ingredient that has perishable food properties, so it requires attention so that its quality is always maintained. Chicken meat has a high protein content, so it is susceptible to damage [2]. High protein content and postharvest handling also make chicken meat susceptible to microbial growth [3] The chemical composition of chicken meat consists of 74.86% water content, 23.20% protein, 1.65% fat, 0.98% minerals, and 114 kcal calories. The pH value of chicken meat after 24 hours (post-mortem) is 5. 5-5.9. Chicken meat is a source of animal protein rich in calories, fat, vitamins and minerals [4] Initial problems with chicken meat often occur due to biological factors, namely the discovery of Escherichia coli and salmonella sp., which is beyond the threshold of the Indonesian National Standard (SNI: 3932: 2008). An increase in the number of bacteria beyond the threshold can cause chicken meat to experience damage to its nutritional value and a decrease in quality due to the process of decay by bacteria. Hence, the meat is unfit for consumption [5].
Microorganism contamination conditions outside the threshold can potentially cause dangerous diseases if consumed by humans, often called foodborne diseases. Therefore, Escherichia coli bacteria in chicken meat must be known to ensure the feasibility of chicken meat for consumption [6].
In the process of slaughtering chickens, both at the Chicken Slaughterhouse (TPA) and Traditional Markets, they are prone to contamination by Escherichia coli and Salmonella sp.
Factors that can trigger contamination usually occur when handling chicken slaughter, which is not good; the cutting location is dirty, and the equipment used in the cutting process can cause contamination. Research on Escherichia coli detection conducted by [7] on chicken meat samples taken along the distribution chain in Gowa Regency showed (100%) of 24 meat samples contaminated with Escherichia coli bacteria and exceeded (BMCM) and Salmonella sp. chicken meat conducted by [8] who took samples from two different locations obtained a percentage of 55%, namely from traditional markets as many as 17 out of 40 samples (42.5%) while from supermarkets obtained 5 out of 40 samples (12.5%).
Based on the explanation above, it is necessary to research to detect the level of contamination by

Materials
The research was carried out at chicken slaughterhouses (Johor, Setia Budi and Padang Bulan) and traditional markets (Johor, Setia Budi and Padang Bulan), followed by examinations at the USU Faculty of Mathematics and Natural Sciences Microbiology Laboratory. This research was conducted in May-June 2022.
The materials used in this study were 60 samples of chicken meat, with 25 grams of each sample taken from traditional chicken slaughterhouses and markets. The media for testing were a solution of Buffered Peptone Water (BPW) Sigma-Aldrich, Eosin Methylene Blue Agar (EMB) Sigma-Aldrich, Salmonella Shigella Agar (SSA) Merck, Aquadest, 70% alcohol, cotton, and tissue.
The tools used in this study were stationery, sterile plastic for packing samples, a freezer, a spatula, test tubes, Erlenmeyer flasks, test tube racks, Bunsen burners, Petri dishes, incubators, autoclaves, sterile cabinets, ice boxes, analytical scales, boxes cooler, marker, gloves, mask and lamp, pestle and mortar, tip and micropipette, bunsen, matches, marker, cling wrap, aluminium foil, hot plate, vortex, measuring cup, magnetic stiver.

Methods
This research is a survey study of meat chicken from slaughterhouses and traditional markets to Chi-Square test is faced as a test of whether the difference between the observed frequency and the expected frequency of a limited sample is significant or not [9] Meanwhile, to see the difference in the number of Escherichia coli found in fresh chicken meat at Chicken Slaughterhouses (Johor, Setia Budi and Padang Bulan) and Traditional Markets (Johor, Setia Budi and Padang Bulan), is continued with a different t-test (partial test /individual) with statistical software. According to [10], a different test t-test is used to test how far the independent variables used in this study are affected individually by partially explaining the dependent variable.

Sample Examination for Escherichia coli and Salmonella sp. (SNI:2897:2008)
The initial stage was carried out, namely the preparation of the meat sample before analysis by grinding the samples taken and weighing first as much as 25 grams and then adding 225 ml of BPW solution in the stomacher for 2 minutes. Then pour 9 ml of the BPW solution into a sterile test tube and add 1 ml of the 10-1 dilution suspension with a sterile pipette into the 9 ml BPW solution to get a 10-2 dilution. Make a 10 -3 and 10-4 dilution similarly. Then 1 ml of the suspension from each dilution was put into a sterile petri dish. Then the EMBA and SSA media were cultured in a petri dish for 24 hours.

a. Making Buffered Peptone Water (BPW) Medium
A total of 4.5 grams of Buffered Peptone Water medium was weighed, put into a 250 mL Erlenmeyer then, added 225 mL of distilled water was and stirred until homogeneous. The medium was sterilized using an autoclave at 121 0 C with a pressure of 15 psi/2 atm for 15 minutes. Salmonella colonies are colourless, transparent and have a black precipitate.

Bacterial Analysis of Escherichia coli
The results of the analysis of Escherichia coli in broiler meat samples marketed at chicken slaughterhouses and traditional markets in Medan City can be seen in Table 6 below.  Table 6 shows that the average amount of Escherichia coli contamination in chicken slaughterhouses is 3.15 log CFU/g and in traditional markets with an average of 3.39 log CFU/g.
Contamination at traditional markets can be caused by unhygienic handling, stacked meat, storage conditions without refrigeration and being in the open air [6]. Based on SNI 3932: 2008, the maximum limit for microbial contamination (BMCM) of Escherichia coli on the microbiological quality requirements for meat is 1x10 1 Colony Forming Units per gram (CFU/g) [7]. The results of the analysis from Table 6 showed that of the 30 samples of broiler chicken meat from chicken slaughterhouses and 30 samples of broiler chicken meat from traditional markets analyzed showed Escherichia coli testing in research conducted in the laboratory; there were 60 chicken meat samples (100%) that exceeded the maximum limit of microbial contamination of chicken meat bacteria contaminated with Escherichia Coli bacteria.
These results are the same as research conducted by [7] on chicken meat samples taken along the distribution chain in Gowa Regency, showing (100%) of 24 meat samples were contaminated with Escherichia coli bacteria and exceeding (BMCM). Research by [11] showed that meat samples in Gorontalo City consisting of 13 samples and nine samples (69%) had exceeded the Maximum Microbial Contamination Limit (BMCM).
Based on the results of the t-test, it was found that the number of Escherichia coli bacteria in chicken slaughterhouses and traditional markets was not significantly different (P>0.05), so there was no significant difference between the average number of Escherichia coli contamination in samples of broiler chicken sold in chicken slaughterhouses and traditional markets in the city of Medan. The average at the slaughterhouse was 3.15 log CFU/g, and the average at the traditional market was 3.39 log CFU/g. According to Gustiani [12] and [13] Table 7 below.  Microbial contamination in poultry products can also be caused by livestock manure that has been infected with Salmonella, which contaminates the feed and drinking areas of livestock so that it enters and multiplies in the digestive tract of poultry. Another thing that might happen is when cutting and packing with a knife or other tools; the carcass is contaminated with Salmonella bacteria more after the slaughter process than before.

Conclusions
Contamination of Escherichia coli in samples of broiler meat originating from chicken slaughterhouses and traditional markets in Medan city can be stated that all of them exceed the threshold determined by SNI 3932: 2008, namely 1x10 1 CFU/g, while the level of contamination of Salmonella sp. in the sample of chicken meat that comes from chicken slaughterhouses is 56% and that comes from traditional markets is 66%.