Bacteria on Stainless Steel Surfaces | Experiment

bacterium on Stainless Steel Surfaces ExperimentThe chemic bond of bacteria on nutriment bear on resurrects and in the surroundings can example po cristaltial cross-contamination, which can lead to victuals spoilage, possible pabulum safety concerns, and step up destruction. Food contact places use for fodder handling, storage or processing be areas where microbial contamination commonly occurs. Even with proper modify and sanitation regimes or practices in place, bacteria can remain attached to the surfaces and this attachment can lead to biofilm formation. The purpose of this study was to identify the presence of pathogenic microorganism in a fodder processing area and to evaluate the set up of the clean procedure on the microbial load in the sustenance processing area. Ten replicate food contact surfaces were tried upright vane, stain and woodwind instrument, with adjacent areas being sampled in the lead and after change. The test surfaces were analyz ed with a swab method in advance and after the cleaning stage. The imparts of these studies indicate that cardinal of ten filthless brand surface were grime before cleaning and no surface was pollute after cleaning. Furthermore, three out of ten marble surfaces were bemire before cleaning and one surface was contaminated after cleaning. sextuplet of ten wood surfaces were heavily contaminated before cleaning and three surfaces were contaminated after cleaning. The difficulty in cleaning was related to the amount of surface damage and it is best to avoid this type of surface. Hypochlorite solution that was used for cleaning the surfaces in this study was considered to be effective against the foodborne pathogens tested. This study has highlighted the fact that pathogens remain viable on dry stainless trade name surfaces and present a contamination jeopardise for considerable periods of time, dependent on the contamination directs and type of pathogen.Keywords Microorgan isms Survival Cross-contamination Food contact surfaceInt retinal perchuctionFood contact surfaces are the chief inhabitant of biofilm that can host potentially harmful microorganisms. This, therefore, is a prominent phenomenon in food processing plants owing to dregs and residues of all sorts chemical, biological, organic, and/or inorganic -which sort up on the surfaces of equipments that may get in contact with food (Mafu et al. 2010). The presence of these undesirable microorganisms to the material surfaces is a source of concern, as this can result in food cross-contamination, leading to food poisoning. Under favourable circumstances (temperature, pH, relative humidity), pathogenic microorganisms are able to survive and/or replicate on a bigger scale within the biofilm. In domestic kitchens and food processing industries, foodborne illness can result from incorrect storage of foods, particularly with gaze to temperature, contamination of raw or cooked foods before consumpti on, by contact with other foods or utensils (food contact surfaces ) carrying pathogens, and inadequate cleaning procedures that may not see roll in the hay removal of microorganisms (Teixeira et al. 2007).In food processing industries, food contact surfaces, such as stainless steel, marble and wood may create an enabling environment for the choice of the microorganism, leading to serious hygienic problems. Furthermore, dead ends, corners, joints, valves and any other hard-to-reach places are the most appropriate areas for the presence of bacteria. (Peng et al. 2001).The value of maintenance and disinfection processes in food processing industries depends, to a large extent, on the design and maintenance programmes adopted by the phoner.Lack of efficacy in cleaning procedures may allow tenacity and survival of pathogens in foods owing to their consistent adherence to food contact surfaces. This may lead to transfer of microorganisms from people, objects or contaminated food to o ther food or material, hence leading to cross-contamination. People can, in many ways, be a source of cross-contamination to foods (Holah and Thorpe, 1990).Food can be contaminated when it is handled, so it is actually important that people who may be carrying or suffering from certain diseases do not handle food. Contamination can also be passed from equipment when contacting food. It specifically happens when utensils or equipment are not efficiently cleaned and sanitized between each use and may lead to development of biofilm, creating favourable conditions for the survival of the pathogens. Contamination from food to food occurs mainly when raw foods come into contact with cooked or prepared foods (Montville et al. 2001).The persistent presence of microorganisms in food processing factories, specifically on food contact surfaces despite deliberate efforts to combat the phenomenon, poses great challenges to the company. It reduces the profit margins of the industries due to the increased cost incurred in the attempts to adopt advanced cleaning services and programmes. A potential effect of the presence of microorganisms on food surfaces is food poisoning. Occurrence of food poisoning will mean great damage to the image of the company and persistent stress on the part of the management, thus derailing the progress of the company.Cross contamination is also becoming a common problem both in the kitchen setting and in industry. Transfer of resistant pathogens and microorganisms across and around these food p terminalucers through various agents and factors that propagate and carry the pathogens is a health hazard. Studies show that the train of contamination varies depending on the duplication and the rate of material handling that occurs in the factory. In this context, therefore, workers hands, utensils and the broad extension of all food contact surfaces contribute to in cross contamination (Zhao et al. 1998).A thorough examination of the whole concept of microbial survival and persistence on food contact surfaces despite usual cleaning procedures and revised designs of the food contact surfaces (such as textural properties, maintained solid surface hydrophobicity) will reveal that more detailed analysis and studies should be focussed on the factors that create an enabling environment for the persistent replication and presence of the foodborne pathogens in the food processing industries and kitchen setting (Scott and Bloomfield, 1990). The study of various relevant properties for the microbial adhesion process has been another imperative goal of this study and the purpose behind it is to obtain a broader knowledge base of the mechanisms of bacterial adhesion to food contact surfaces so as to formulate strategies for its control.The objective of this study is to identify the microorganisms that can survive in the food contact surface, such as stainless steel, marble and wood, even after cleaning procedures, thus increasing the risk of food cross-contamination. The study will focus on microorganisms that survive in the food processing areas even after the cleaning procedure. Foodborne pathogenic bacteria adhere to inert surfaces they may exhibit a greater scale of resistance to chemical or ordinary cleaning and fumigating agents (Barnes et al. 1999). The concept of cross contamination is of major concern in the food processing industries that constitute a threat to forgiving health because they cause most food borne illness outbreaks. Food poisoning is one of the consequences of adherence of microorganisms to food contact surfaces (Sattar et al. 2001).Materials and MethodsPremisesIn order to appraise the microbiological safety of a food processing area in Oman, three types of food contact surfaces were studied Stainless steel, marble and wood. Ten surfaces of each of the three types were tested, with the adjacent areas of each one being sampled before and after cleaning. This study was performed randomly in nineteen selected Army camps kitchen.Data analysisSwabs were taken from the food processing area within the Royal Army camps kitchen and sent to the food microbiology laboratory of the environmental of health unit for analysis. The swabs were each tested for pathogenic bacteria linked with food and coliforms that can survive on the surface of food preparation areas before and after cleaning. The plates were read for the number of colonies of pathogenic bacteria and coliforms. A Phoenix machine was used to identify the bacteria and readings were taken directly from the Phoenix machine. A Phoenix is automated microbiology system is intended to provide rapid identification results for most aerobic and facultative anaerobic gram positive bacteria as well as most aerobic and facultative anaerobic grand negative bacteria. The identification of the Phoeonix panal uses a series of conventional, chromogenic and fluorogenic biochemical tests to identify the organism. The growth-based and e nzymatic substrates are employed to cover the different types of reactivity among the range of taxa. The tests are based on the use of bacteria and deterioration of specific substrates notice by different indicator systems. Acid production is indicated by a agitate in phenol red indicator when an isolate is able to utilize a carbohydrate substrate. A yellow colour is produce by Chromogenic substrates upon enzymatic hydrolysis and the enzymatic hydrolysis of fluorogenic substrates results in the release of a fluorescent coumarin derivation. Organisms that utilize a specific carbon source reduce the resazurine based indicator. These results were recorded and the log decrease was calculated for each plate at each dilution rate after and before cleaning of the surface (BD Phoenix, 2007). try out methods and microbiological examination (Before Cleaning)Tests using the swab method were carried out on surfaces contaminated with food borne pathogens in a food processing area. Tubes conta ining 10 ml of sterile buffered peptone saline solution were used to flush the swabs prior to sampling. Cotton swabs were removed from their sterile packaging and were held by the stick while they were moistened with buffered peptone saline solution, the excess broth was returned into the bottle. All surfaces were prepared in sizes of 20 x 20 cm2 for survival experiments. The swabs were rotated while in contact with the food preparation surface. aft(prenominal) the defined area was swabbed, the swab was returned to the test tube-shaped structure containing the buffered peptone saline solution to dislodge the bacteria. Serial dilutions of the swab solutions were prepared and duplicate pour plates were prepared for each dilution using nutrient nutrient agar-agar-agar-agar, MacConkey agar and decline agar. The plates were incubated for 24 hours at 37oC.Sampling methods and microbiological examination (After Cleaning)The surfaces were washed with hot water and chemical detergent and then rinsed with hot water. Then the surfaces (stainless steel, marble, and wood) were disinfected with 5.25% of hypochlorite solution for 10 minutes. The surfaces were allowed to dry before sampling. The swabbing method used was as above. Duplicate pour plates were prepared for each dilution using nutrient agar, MacConkey agar and caudex agar. The plates were incubated for 24 hours at 37oC.Sampling methods and microbiological examination (Control) close to of the food borne pathogen strains used as a control for these experiments on the surfaces (stainless steel, marble, and wood), such as Staphylococcus aureus and Escherichia coli were obtained from the Armed Forces Hospital Laboratory. For their control strains a clean stainless steel table without tiny groove was prepared as the food contact surface because it can be fabricated with a smooth cleanable finish. The table also was disinfected with 5.25 % of hypochlorite solution for 10 minutes. The surface was then washed with hot water, with chemical detergent and rinsed with hot water. The surface was allowed to dry before sampling. The test suspensions were prepared by making serial dilutions of the microorganisms in peptone saline solution. Two different levels of contamination were prepared high contamination (approximately 106 resolution forming units (CFU)/ ascorbic acid cm2) and low contamination (approximately 103 CFU/100 cm2), obtained by spreading 1 ml of an appropriate solution on a surface of 20 x 20 cm2 over the grid reference table. The table was allowed to dry for 15 minutes to represent the environment of food preparation area. Selective agar media were used for the enumeration of pathogens broth agar for Staphylococcus aureus, incubated for 24 hours at 37oC and MacConkey agar for Escherichia coli incubated for 18 24 hours at 37oC. Furthermore, the effects of two different contamination levels on the survival of pathogens on dry stainless steel surfaces for 24 hours at room temperatur e were investigated.ResultMicrobial survival on food contact surface (stainless steel surface) evade 1 The Colony descriptions of the microbial survival on stainless steel surface submit 1 shows the Colony descriptions result of the microorganisms stranded from stainless steel surface. Three of ten stainless steel surface were contaminated with bacteria before cleaning. shelve 2 The colony tally of the microbial survival on stainless steel ensample zero(prenominal)Serial ten-fold dilutions in deionised water diluentscolony count (CFU ml-1) before cleaningcolony count (CFU ml-1) After cleaning23.2 x 102bacteria no(prenominal) Detected62.6 x 102Bacteria no. Detected94.3 x 102Bacteria none DetectedTable 2 shows the result of the colony count obtained before and after cleaning of the stainless steel surface.Table 3 yard stain result of the microbial survival on stainless steel surface warning No.2 thousand stain resultGram negative, rod shape take No.6Gram stain resultGram positiv e cocci test No.9Gram stain resultGram negative, rod shapeTable 3 show the result of the Gram stain of bacteria that were isolated from the stainless steel surface before and after the cleaning stage.Sample No.2Sample No. In genus Phoenix machine344 come to of Bacteria spy before cleaningKlebsiella aerogenesName of Bacteria find After cleaningNot noticeSample No.6Sample No. In phoenix machine367Name of Bacteria detected before cleaningStaphlococcus aureusName of Bacteria detected After cleaningNot detectedSample No.9Sample No. In phoenix machine382Name of Bacteria detected before cleaningKlebsiella aerogenesName of Bacteria detected After cleaningNot detectedTable 4 The Identification of bacteria by phoenix machine that survived on the stainless steel surface before the cleaning stageTable 4 show the result of bacterial identification that obtained by phoenix machine which was isolated from stainless steel surface before and after the cleaning stage.Microbial survival in food con tact surface (Marble surface)Table 5 The Colony descriptions of the microbial survival on marble surfaceSample of posture No.1Nutrient agarNo emergenceMacConkey agarNo fruitBlood agarNo yieldSample of perspective No.2Nutrient agarNo ingatheringMacConkey agarNo GrowthBlood agarNo GrowthSample of location No.3Nutrient agarNo GrowthMacConkey agarPink in colour, mucoidBlood agarwhite, large and mucous coloniesSample of location No.4Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample of location No.5Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarsmooth, round, grayish-white coloniesSample of location No.6Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample of location No.7Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample of location No.8Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample of location No.9Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample of location No.10Nutrient agarSmall circular colonies, yellow in colourMacConkey agarNo GrowthBlood agarswarming motilityTable 5 shows the colony descriptions result of the microorganisms isolated from the marble surface. Three of ten marble surfaces remained contaminated with bacteria before and after cleaning.Table 6 The colony count of the microbial survival on marble surfaceSerial dilutions in deionised water diluentscolony count (CFU ml-1) before cleaningcolony count (CFU ml-1) After cleaningSample No.3*TFTCBacteria Not DetectedSample No.55.1 x 102Bacteria Not DetectedSample No.10TMTCTMTC*TFTC Too Few To Count TMTC Too Many To CountTable 6 shows the result of the colony count obtained before and after cleaning stage of marble surface.Table 7 Gram stain result of the microbial survival on marble surfaceSample No.3Gram stain resultGram negative, rod shapeSample No.5Gram stain resultGram negative, rod shapeSample No.10Gram stain resultGram negative, rod shapeTable 7 show the result of the Gram stain of ba cteria that was isolated from the marble surface before and after the cleaning stage.Table 8 The Identification of bacteria by phoenix machine that survived on the marble surface before the cleaning stageSample No.3Sample No. In phoenix machine301 MarbleName of Bacteria detected before cleaningKlebsiella pneumoniaName of Bacteria detected After cleaningNot DetectedSample No.5Sample No. In phoenix machine326 MarbleName of Bacteria detected before cleaningYersinia enterocoliticaName of Bacteria detected After cleaningNot DetectedSample No.10Sample No. In phoenix machine381 MarbleName of Bacteria detected before cleaninggenus Proteus vulgarisName of Bacteria detected After cleaningProteus vulgarisTable 8 show the result of bacterial identification that obtained by phoenix machine which was isolated from marble surface before and after the cleaning stage.Microbial survival in food contact surface (Wood surface)Table 9 The Colony descriptions of the microbial survival on wood surfaceSamp le location No.1Nutrient agarNo GrowthMacConkey agarNon-lactose fermenters coloniesBlood agarWhite, non haemolytic coloniesSample location No.2Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample location No.3Nutrient agarsmooth, translucent large colonies , greenish blue growth and rouge diffuses into mediumMacConkey agarNo GrowthBlood agarlarge brownish coloniesSample location No.4Nutrient agarWhite, smooth, round coloniesMacConkey agarNo GrowthBlood agarNo GrowthSample location No.5Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample location No.6Nutrient agarCircular, smooth, opaque coloniesMacConkey agarNo GrowthBlood agarswarming motilitySample location No.7Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthSample location No.8Nutrient agarsmooth, translucent large colonies , greenish blue growth and pigment diffuses into mediumMacConkey agarslight pink coloniesBlood agarlarge brownish coloniesSample location No.9Nutrient agars mooth, translucent large colonies , greenish blue growth and pigment diffuses into mediumMacConkey agarslight pink coloniesBlood agarNo GrowthSample location No.10Nutrient agarNo GrowthMacConkey agarNo GrowthBlood agarNo GrowthTable 9 shows the colony descriptions result of the microorganisms isolated from the wood surface. Six of ten wood surfaces remained contaminated with bacteria before and after cleaning.Table 10 The colony count of the microbial survival on wood surfaceSample No.Serial ten-fold dilutions in deionised water diluentscolony count (CFU ml-1) before cleaningcolony count (CFU ml-1) After cleaningSample No.16.4 x 102Bacteria Not DetectedSample No.35.3 x 102Bacteria Not DetectedSample No.42.7 x 102Bacteria Not DetectedSample No.6TMTCTMTCSample No.81.67 x 1032.9 x 102Sample No.99.3 x 1023.6 x 102Table 10 shows the result of the colony count obtained before and after cleaning stage of wood surface.Table 11 Gram stain result of the microbial survival on wood surfaceSampl e No.1Gram stain resultGram negative, rod shapeSample No.3Gram stain resultGram negative, rod shapeSample No.4Gram stain resultGram negative, rod shapeSample No.6Gram stain resultGram negative, rod shapeSample No.8Gram stain resultGram negative, rod shapeSample No.9Gram stain resultGram negative, rod shapeTable 11 show the result of the Gram stain of bacteria that was isolated from the wood surface before and after the cleaning stage.Table 12 The Identification of bacteria by phoenix machine that survived on wood surface before the cleaning stageSample No.1Sample No. In phoenix machine86 woodName of Bacteria detected before cleaningAcinetobacter baumanniiName of Bacteria detected after cleaningNot DetectedSample No.3Sample No. In phoenix machine301 woodName of Bacteria detected before cleaningPseudomonas sppName of Bacteria detected after cleaningNot DetectedSample No.4Sample No. In phoenix machine326 woodName of Bacteria detected before cleaningEnterobacter hafinae alveiName of Bac teria detected after cleaningNot DetectedSample No.6Sample No. In phoenix machine342 woodName of Bacteria detected before cleaningProteus vulgarisName of Bacteria detected after cleaningProteus vulgarisSample No.8Sample No. In phoenix machine369 woodName of Bacteria detected before cleaningPseudomonas aeruginosaName of Bacteria detected after cleaningPseudomonas aeruginosaSample No.9Sample No. In phoenix machine385 woodName of Bacteria detected before cleaningPseudomonas aeruginosaName of Bacteria detected after cleaningPseudomonas aeruginosaTable 12 shows the result of bacterial identification that obtained by phoenix machine which was isolated from wood surface before and after the cleaning stage.ControlTable 13 Survival of Staph aureus and E.coli on stainless steel surfacesStaphylococcus aureusEscherichia coliTime of swab process after contaminationHigh contamination level (106 colony)CFU/100 cm2Low contamination level (103 colony)CFU/100 cm2High contamination level (106 colony)C FU/100 cm2Low contamination level (103 colony)CFU/100 cm2After 15 minute2.0 x 1071.0 x 1041.6 x 1075.2 x 103After 2 Hours1.73 x 1079.1 x 1038.3 x 1061.8 x 103After 6 Hours1.3 x 1073.8 x 1032.1 x 106No growthAfter 12 Hours5.8 x 106No GrowthNo GrowthNo growthAfter 24 HoursNo growthNo GrowthNo GrowthNo growthTable 13 shows the survival of Staphylococcus aureus and Escherichia coli on stainless steel surfaces at room temperature (25oC) for 24 hours at two contamination level high contamination level of (106 colony CFU/100 cm2) and Low contamination level (103 colony CFU/100 cm2).DiscussionSampling food contact surfaces is a complex problem, and the results depend on many factors, including the type of surface, the cleaning solution, the sources of contamination, and the temperature. The accuracy and reproducibility of all sampling methods are reduced when the numbers of bacteria on the surface are low. Some differences between methods are probably due to an uneven distribution of bacter ia on the surface. The type of surface markedly influenced the cleaning results. For this study, nineteen selected premises were tested/studied (Ten replicate surfaces were tested stainless steel, marble and wood, with adjacent areas being sampled before and after cleaning). The results of these studies indicate that three of ten stainless steel surfaces were contaminated before cleaning the surfaces and no surface was contaminated after cleaning, which means that stainless steel surfaces were more easily cleaned. Furthermore, three out of ten marble surfaces were contaminated before cleaning and one surface was contaminated after cleaning the surfaces, which means marble surfaces were easily cleaned but using the wrong cleaning products and the wrong cleaning techniques can damage the marble because marble is a calcium-based natural stone which is highly sensitive to acidic materials (Marble Institute of America, 2012). Stainless steel resists impact damage but is vulnerable to cor rosion, while marble surfaces are prone to deterioration and may develop surface cracks where bacteria can pick up (Leclercq and Lalande, 1994). Wood surfaces were particularly diffi