In this study the frequency of growth of coliform ranges from 53% on restaurant to 75% on hotel utensils. It was found that the mean log count of coliforms ranges from 3.30 ± 3.24 on restaurant dipper to 4.57 ± 2.85 on hotel tray. The frequency of growth of S.aureus ranges from 33.3% on hotel to 68% on restaurant dipper. The mean log count of S.aureus ranges from 3.20 ± 3.37 on restaurant glass to 4 ± 3.59 on hotel tray. Similarly, the frequency of growth of aerobic plate count (mesophilic plate count) ranges from 86% on restaurant glass to 100% on hotel utensils. The mean log APC (aerobic mesophilic bacteria) count ranges from 7.17 ± 3.33 on restaurant glass to 9.37 ± 0.49 on hotel tray. Faecal coliforms and E.coli was detected in 12.5% and 6.25% of hotel utensils and 15% and 1.78% of restaurant utensils.
The finding of present study is comparable to study made at University of Tennessee by Cosby et al. (2008) where the mean log APC ranges from 3.55 log10 CFU/50 cm2 to 3.81 log10 CFU/50 cm2, the mean coliform counts ranges from 35.62 CFU/50 cm2 to 10.72 CFU/50 cm2) and E. coli was detected in 1.6% in the range of 1 to 35 CFU/50 cm2 except that the present study use count per 100cm2. Similarly, the APC log count of the present study is in harmony with a study made in Chinese households in which the aerobic plate counts for dishcloths were 10–109 cfu/cm2 in the range of 150 cfu/cm2 to 1.776×109 cfu/cm 2 (Beijing) and 62.5 cfu/cm2 to 8.75×108 cfu/cm2 (Shanghai) regardless of institution involved, material type and sample size which was very large in Chinese study (Jin et al., 2014).
The APC in the present study is similar with study of Rossi et al.(2012) and Abubakar et al. (2012) in which the APC count ranged from 3.4 to 10.4 log10 CFU/sponge, with an average of 9.1 log CFU/sponge. With regard to fecal coliforms and S.aureus, high count was observed in the study of Rossi et al. (2012). Kitchen sponges harbor large number of micro-organisms in terms of type and number if not appropriately washed and can cause cross contaminations (Mead et al., 1999). The study highlighted insufficiency of food handler’s adherence to good manufacturing practice and sanitation standard operating procedures.
In the study made in University of Technology, Yola, total bacterial count were found which ranges from 1.0x104 cfu/ml in knives and cups to 2.5 x106 cfu/ml in plates (Maori and De, 2018). Other study made in Terengganu, Malaysia Lani et al.(2014) revealed that the mean log10CFU/cm2 APC ranges from 1.37 ± 1.45 on surface griller to 4.68 ± 0.43 on table of preparation. Similar result was obtained by Cunningham et al. (2011). Other related study revealed the total bacterial count (TBC) per ml of the samples ranges from 1.8x103 to 7.7x103 cfc/ml. But, in contrast to the present study, E.coli was detected in higher frequency (66.67%) (Orogu et al., 2017). Study made in the sultanate of oman and others, Sudheesh et al. (2013) and Nhlap et al. (2014) revealed that high plate readings of total colony count (TCC) and indicator organisms such as total coliforms, yeasts and molds and Escherichia coli were obtained from samples collected from most food contact surfaces.
The growth frequency of Coliforms, E.coli and S.aureus and the mean log count of APC are in line with the study conducted in Brazil where Coliforms, Escherichia coli and Staphylococcus aureus were detected in 24 (40.7%), 2 (3.3%) and 13 (22.0%) of the food contact surfaces, respectively and the mean aerobic mesophilic bacteria count was 3.1 log CFU/100 cm2 of surface area (Trindade et al., 2014). Human skin is the ideal habitat for S.aureus and fecal contamination is also common. The factors that could play an important role in food borne illnesses are the worker training, awareness of handling food and hygiene, correct techniques and implementation of quality standards in food premises (Campos et al., 2009).
In other study in Accra, Ghana, Addo et al. (2007), thirty-seven (37) (35%) of the swab samples showed the presence of coliforms and in contrast to the present study, Escherichia coli was absent in all the 105 samples. The total count of aerobic bacteria was high in the swabs from the working surfaces and cutting boards (> 103 cfu/ml). In the study made in Serbia, take-away food establishments had the highest share of results = 2 log10 CFU/cm2 for both stainless steel and plastic surfaces. Highest share of stainless-steel surfaces with microbial load = 2 log10 CFU/cm2 were cutlery, dishes and knives. Plastic dishes had the highest share of results = 2 log10 CFU/cm2 while cutting boards had the majority of results between 1 log10 CFU/cm2 and 2 log10 CFU/cm2 (Djekic et al., 2016).
In contrast to the current study, the study conducted in South Africa, revealed that E. coli was detected in 50%, 30%, 30%, and 50% of samples from cutting boards, knives, plates and spoons, respectively (Mkhungo et al., 2018). Similarly, in other related study, out of the 50 samples analysed, 13 (26%) were positive for Escherichia coli and 0% was positive for Staphylococcus aureus. Out of the 13 samples that were positive for Escherichia coli, 8 (61.5%) were from plates, 3 (23.1%) were from chopping boards and 1 (7.7%) was from table and spoon each (Mohammed et al., 2018).
In this study we found that except for S.aureus count on hotel dippers and glass; all other counts are beyond the acceptable limit. In contrast, in follow-up study in United Kingdom, from 585 swabs examined 68% (397) were of satisfactory microbiological quality and 32% (188) were unsatisfactory. Swabs from chopping boards gave a significantly higher proportion of unsatisfactory results (84/141; 60%) compared to those from all other surfaces (104/444; 23% (Willis et al., 2013).