Microbial Load in Kitchen Dish Wash Scrubber

Introduction: Kitchen sponges are most commonly used cleaning equipment. These sponges were heavily contaminated with the microorganisms which acts as a carrier of food borne diseases. It provides favourable conditions for the growth of bacteria and other microorganisms. It acts as a reservoir of pathogens and a vector of cross contamination. Proper sanitization techniques must be followed to avoid cross contamination. Aim: The aim of the study was to evaluate the microbial load in used kitchen dish wash scrubbers. Materials and Method: Twenty dish wash scrubbers were collected in a sterile disposable container. Moisture was removed by drying the scrubber. The procedures were conducted after 5 days. Measured the weight of the scrubber weighing 1 gram and soaked it in 500 ml of sterile saline for 30 minutes, agitated it and transferred 10 microliter to the media. And identified the organisms by the growth characters on the media for the possible pathogens. Result: From the growth characters the organisms identified were Coliform, Bacillus and Staphylococcus. Conclusion: This study showed that scrubbers were not clean and were at increased risk of food poisoning. Kitchen sponges were highly contaminated with potentially pathogenic bacteria which might be transferred from the overall kitchen environment to food contact surfaces and consequently cause food contamination Original Research Article Harini and Muralidharan; JPRI, 33(48B): 212-217, 2021; Article no.JPRI.74411 213


INTRODUCTION
Scrubbers and dish wash scrubbers are the most commonly used cleaning equipment in kitchens all over the world. It is most often used to clean surfaces, dishes, pots and pans, refrigerators, countertops, sinks, stovetops and handles. Using the filthy and unwashed sponges to clean surfaces leads to the transfer of microorganisms like bacteria and viruses. Using the sponges covered with harmful bacteria to clean places and things like faucet handles, plates and utensils allow the bacteria to spread easily. Direct contact of human beings to these places leads to many diseases [1,2]. Kitchen wipes address a significant vehicle of microbial transmission and upkeep of waste microscopic organisms and pathogenic strains liable for food borne infections. Kitchen wipes are usually utilized by customers for cleaning up and scouring of skillet and meals, but at the same time are utilized for cleaning kitchen surfaces, like sinks, fridges and burners. Brushes are the predominant utensils for manual cleaning of dishes all over the world. In an observational investigation in the UK, in a few households the same scrubber is used to clean the dishes and the other areas of the kitchen which directly leads to the contamination of food and also a predominant reason for food borne diseases all over the world.
Bacteria multiply rapidly in a used sponge because of the presence of moisture and nutrients which supports the growth of many pathogenic microorganisms. These favourable conditions enhance the growth of bacteria. Successive use of the same dirty sponges leads to the transfer of bacteria from one surface to the other during the cleaning process. Kitchen dish wash scrubber is identified as the ideal place for the growth of harmful and the most pathogenic bacteria and viruses. Pathogens like E. coli Salmonella, Enterobacter cloacae and Klebsiella pneumoniae are most commonly identified in the dirty dish wash scrubbers [3]. Chemical ingredients or ordinary dishwashing soaps do not considerably reduce microbial load in kitchen sponges.
Furthermore, multi-drug-resistant bacteria were widespread in the home environment, with no significant differences found between biocide users and non-users, as well as pathogen recovery frequency [4]. Our team has extensive knowledge and research experience that has translate into high quality publications [5][6][7][8][9].
Domestic dish wash scrubbers are not a threat to the environment or considered to pose any hazardous warning until it is revealed to be heavily contaminated. Selected opportunistic pathogenic fungi, viruses and bacteria is not only limited to the rubber seals but it spreads to the entire interior and provides an environmentinfluenced microbiota throughout the kitchen. To minimize the potential risk of spread of bacteria sponges should be decontaminated at regular intervals. Regular heating of the contaminated sponge is advisable or soaking the contaminated sponge in the bleach solution or cleanser can be done for the reduction in the microbial load of bacteria [10]. The aim of the study is to observe the microbial load in the used domestic kitchen dish wash scrubber.

MATERIALS AND METHODS
Twenty domestic dish wash scrubbers were collected randomly from different households in a sterile disposable container. Dried the scrubber and removed the moisture from it. The scrubber was isolated for 5 days. The weight of the scrubber was measured and the average value was calculated. The scrubber piece weighing 1 gram was soaked in a sterile saline and agitated for 15 minutes and transferred 10 microlitre of saline to the media. Blood agar was used as a media to culture the fastidious organisms. Total CFU was calculated per ml and identified the organisms by its characteristic growth on the media and by the standard biochemical protocol for possible pathogens. The colonies formed by the organisms were counted and the number of microbes isolated per gram were calculated and the mean value was evaluated.

Statistical Analysis
All the data obtained were analyzed by Student's-t-test using MS-Excel, represented as mean ± SD. The results were computed statistically. In all tests, the level of statistical significance was set at p<0.05.

RESULTS AND DISCUSSION
From the growth characters the organisms identified were Coliform, Bacillus spp and Staphylococcus spp. In 1g of scrubber the number of microbes isolated varied from 5 to 1658. Total mean value was found to be 629.1. Total number of microbes isolated per gram of each sample was calculated (Table 1). Samples were inoculated onto blood agar (Fig. 1) and the total colony forming unit was counted. A study done with 201 contaminated kitchen sponges revealed that the sponges are heavily contaminated with bacteria. They collected kitchen sponges from different places of work like hotels, restaurants, pastry shops and cafeterias. They reported the presence of coliform bacteria more than one billion CFU/cm 3 . The presence of coliform is an indicator of potential and fecal contamination [15]. Not all the coliform bacteria cause illness, highly notorious species of coliform like E.coli and Shigella cause illness causing food borne diseases. Present study also reported the presence of coliform bacteria. In a previous study done using 16s RRNA sequencing technique they have observed Gammaproteobacteria found in the microbiome of the kitchen sponges analyzed using fluorescence in situ hybridization [16]. In some previous studies Pseudomonas, Bacillus, Micrococcus, streptococcus and Lactobacillus were dominantly found in the contaminated kitchen sponges. Coliform count was more than 4.0 LOG CFU (mm 3 ) -1 [17]. Likewise present study also isolated bacteria like coliform, Bacillus and Staphylococcus.
There are some potential limitations, that is the study is taken into consideration only with small samples and it should be considered to be done on a large scale. And there is a high possibility of occurrence of error. In future decontamination methods should be carried out. In the future it can be formulated for a healthy and hygienic kitchen cleaning practice.

CONCLUSION
This study showed that scrubbers were not clean and were at increased risk of transmitting infection and may cause food poisoning. Kitchen sponges were highly contaminated with potentially pathogenic bacteria which might be transferred from the overall kitchen environment to food contact surfaces and consequently cause food contamination. It will also be responsible for the spoilage of food stored in the vessels washed with such scrubber. A proper cleaning and disinfection done after every use may prevent the spoilative activity of the bacteria in the scrubbers.

CONSENT AND ETHICAL APPROVAL
It is not applicable.

SOURCE OF FUNDING
The present study was supported by the following agencies.