Salmonella RESULTS AND DISCUSSION

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4. RESULTS AND DISCUSSION

4.1 Salmonella

In this research study, out of the 36 samples analyzed, 19 were suspected of Salmonella species being present thereby further identification process, serological test was carried out for this 19 samples. Out of the 19 suspected samples, 6 samples were confirmed to be Salmonella serovars. The 6 confirmed isolates are given in Table 4.0. The samples from serology test confirmed two Salmonella species: S.Weltevreden and S. Agona. Both serovars occurred in some of the samples obtained from RTE food outlets I and II, respectively. S.Weltevreden was found in Outlet I and was isolated from utensils washing water, tea towels, and food preparation tables . S.Agona was found in outlet II and was isolated from utensils washing water and food preparation tables . There were no Salmonella species were isolated from RTE food outlet III. The serology results are presented in Table 5.0. It is noted that only one form of serovar is observed in outlet I and outlet II but in different types of samples. This would most probably indicate that cross-contamination of some sort occurred during the processing period most probably from tables tops onto tea towels being mistakenly placed on the contaminated surfaces, water then was contaminated whilst washing dirty equipment for food preparation placed or used on the preparation tables. That is, the raw materials especially the meat products having being contaminated with the bacteria may have being the cause for contamination of the samples analyzed. On the other hand water could have been the likely source for the cross-contamination. That is, likely from the water source as ground water is used for washing the utensils. However, contaminating the tea towel and the table surface would have to be through contaminated utensils washed in the water or washed food items or hands of persons washing the utensils having touched the tables and tea towels so in turn contamination occurred. In ready-to-eat food outlets, there are so many things that could account for the presence of pathogenic bacteria like the two serovars found in this research. Raw foods especially of animal origin contaminated with Salmonella; infected individuals preparing the food; contaminated water source; and pests and insects are some of the common ways food contact surfaces may be cross-contaminated. 46 Tables where foods are prepared usually come in contact with raw foods animal and plant foods, cutting instrumenst like knives or shredders, chopping boards, and bowls and water drops from wet equipment and raw foods. Furthermore, animals like stray cats, flying insects like flies, and rodents passing through the table tops my be transmitters of the organisms. Such conditions may increase the likelyhood of having the tables surfaces being contaminated with pathogenic organisms like Salmonella. Tea towels are usually used to dry food contact surfaces like utensils, hands of food handling personnel, and table tops. Each area should have designated towels to prevent cross-contamination such as hands of food handlers should not be dried with the tea towle used for drying food utensils. Bryan 1980 mentioned that prime sources of human salmonellosis are from animal origin; furthermore stating that these ilnesses are caused by these foods resulting from improper handling, inadequate thermal processing, cross-contamination of raw to cooked foods, timetemperature abuse, or combinations of these. Table 4.0 Number of confirmed Salmonella isolates. POSITIVE ISOLATES OF SALMONELLA S ITE Utensils’ Rinsing water Tea towels Food preparation tables Hands of food handlers Outlet I 1 3 1 2 2 3 - Outlet II 1 2 02 1 3 - Outlet III - 02 02 - No samples for serology test; Bold values positive number of serovars Table 5.0 Serology test results for Salmonella serovars SAMPLED ITEMS SITE Utensils’ Rinsing water Tea towels Food preparation tables Hands of food handlers Outlet I Salmonella Weltevreden Salmonella Weltevreden Salmonella Weltevreden Negative Salmonella sp. Outlet II Salmonella Agona Negative Salmonella sp. Salmonella Agona Negative Salmonella sp. Outlet III Negative Salmonella sp. Negative Salmonella sp. Negative Salmonella sp. Negative Salmonella sp. 47 Both Salmonella Weltevreden and Salmonella Agona belong to subspecies enteric to which typhoid causing bacteria S. Typhi also belongs. They both cause non- typhoidal salmonellosis. Depending on the infection dose and the clinical picture, Salmonella cases in humans normally follow one of two courses: 1 the typhoid form typhoid diseases is mainly triggered by the serovars S. Typhi, S. paratyphi A, B and C. The disease can be transmitted from man to man. The pathogens are ingested orally and transmitted via blood. The infection dose is low 10 2 - 10 3 cfuml colony-forming units. After a short incubation period a few days up to 3 weeks severe, cyclic general infection occurs accompanied by diarrhoea, high temperature and possible damage to the intestines, heart, liver, kidneys and gallbladder. Particularly in the case of patients with gallstones, the pathogens may be excreted over long periods BfR, 2006. 2 Most of the other Salmonella serovars trigger the so-called enteritic course of the disease in humans enteritis = intestinal inflammation. Depending on the health condition of the persons affected, the minimum infection dose is considerably higher 10 6 cfuml, the incubation period until the manifestation of the disease symptoms is shorter 1-3, possibly 5 days. Inflammation of the intestinal mucosa leads to diarrhoea, sometimes a moderately high temperature; however there may be no manifestation of symptoms of the disease. In animals infection with these pathogens frequently occurs without any symptoms. Ongoing excretion over a period of many years is possible BfR 2006. Both S .Weltevreden and S.Agona happen to trigger enteritis. Many research works have reported ways of transmitting moving pathogenic Salmonella species. Dissemination may occur from contaminated faeces by means of water, crawling or flying insects, or by the fingers of food handlers that practice poor personal hygiene Jay, 2000. In addition to this, transmission could arise from poorly sanitized food processing equipment surfaces and utensils or from water or ice used in food processing and preparation Jay, 2000. Some research studies done in Indonesia isolated Salmonella from foods obtained from traditional markets and from farms. Rusyanto 2005 isolated S. Lexington, S. Kirkee, S. Hadar, S.infantis and S. Paratyphi B from shrimps and the sediment and water from which the shrimps were obtained from. Agustin 2004 isolated S. Weltevreden from fresh lettuce; Ruslan 2003 and Susilawati 2002 detected 48 Salmonella organism in various vegetables including cabbages, bean sprouts, long green beans and carrots, however serovar identification was not carried out. In a study carried out by Meerburg and Kijlstra 2007, rodents were the carriers of Salmonella Enteritidis, whereby rodents in the poultry farms increased Salmonella contamination of chickens and eggs, compared to poultry farms without rodents. Salmonella Agona was isolated from breakfast cereals thought be from the environment of processing lines and equipment Reij and Aantrakker, 2003. A study carried out in Thailand from 1993 to 2002 where isolation of Salmonella species was done on humans showed that Salmonella Weltevreden was the top serovar isolated apart from more than 26 other serovars; Salmonella Agona was also among the serovars isolated from humans Bangtrakulnonth et al 2004. This would indicate that humans would be carriers and that cross-contamination of food contact surfaces and water could be a result of food handler who carries the species. S. Weltevreden is a common cause of gastroenteritis in south-east Asia Bangtrakulnonth et al 2004 and Vo AT et a,l 2006. Research study by Noorzaleha et al 2003 found Salmonella species in some raw vegetables Oenanthe stolonifera, Centella asiatica, Ipomoea aquatica, and Polygonum minus . The most common serotypes isolated were S. Weltevreden 23.5, S. Agona 16.2, S. Senftenberg 10.1 and S. Albany 6.7. This would explain that raw vegetables are possible transmitters of pathogenic Salmonella bacterium. A study done in the United States has suggested that improper food-handling practices contribute to approximately 97 percent of foodborne illnesses in food service establishments and homes Clayton, Griffith, Price, and Peters, 2002. Pathogens that are most commonly associated with inadequate hygiene practices are the enterobacteriaceae, such as Escherichia coli and other coliforms, as well as members of the genera Salmonella , Shigella, Yersinia, Proteus, and Klebsiella Nel et al., 2004. Effective handwashing is an essential control measure for prevention of pathogen transmission in food service establishments, and the health regulations under the Health Act stipulate that it is the responsibility of food handlers to wash their hands thoroughly with soap and water under all relevant circumstances Republic of South Africa, 1999. Facilities for personnel should be adequate, and all handwashing basins in toilet areas must be supplied with hot and cold water, and hand-cleaning preparations in dispensers and paper towels or air hand-dryers should be provided Codex Alimentarius, 1997; Paulson 49 et al ., 1999; South African Bureau of Standards, 2001. The potential for cross- contamination is reduced, however, when disposable paper towels are used Hobbs and Roberts, 1993. Humans are often the source of disease-producing microorganisms, which occur as normal habitants in certain parts of the body, mainly the hair, nose, mouth, throat, bowels, and skin. These microorganisms are then readily transferred to the hands. Even blowing ones nose into a handkerchief can contaminate hands, and food handlers should avoid direct contact with food when possible Martinez-Tome, Vera, and Murcia, 2000; South African Bureau of Standards, 2001. Epidemiological studies show that one factor that often contributes to Staphylococcus food-poisoning outbreaks is the human carrier who handles foods in food service establishments Martinez-Tome et al., 2000. According to the health regulations, food shall not be handled by any individual who has on his or her body a suppurating sore, cut or abrasion, unless the wound is covered by a moisture-proof dressing that is firmly secured Republic of South Africa, 1999. Any behavior that could result in the contamination of food, such as eating and chewing of gum, sticks and sweets should also be prevented in food-handling establishments Republic of South Africa, 1999; South African Bureau of Standards, 2001. It is also essential, when unprotected food or raw food materials are handled, that personnel remove jewelry from their hands, while fingernails should be kept short and clean Republic of South Africa, 1999; South African Bureau of Standards, 2001. Homes and in particular kitchens do provide a variety of opportunities for recontamination Bloomfield, 2003; Redmond and Griffith, 2003. As with food- processing establishments, pathogens may have become established in homes for prolonged periods of time. Only a few studies have addressed the fate of pathogens in kitchens and households in detail. A well-recognized example of recontamination in the home is that where food ready for consumption comes into contact with raw materials through the use of cutting boards and utensils e.g. transfer of pathogens from raw vegetables to cooked poultry; Gough and Dodd, 1998. Children that have suffered from salmonellosis can remain carriers and excrete the pathogen for weeks van Schothorst et al ., 1978. Epidemiological studies have demonstrated the spread of Salmonella in a household with an ill baby Michanie et al., 1987. Quantifying the cross-contamination risk associated with various steps in the food preparation process can provide a scientific 50 basis for risk management efforts in both home and food service kitchens Chen et al., 2001.

4.2 Hygiene and sanitation conditions