International Food Research Journal 18: 465-473 (2011) Review Article Salmonella: A foodborne pathogen Pui, C. F., 1Wong, W. C., 1Chai, L. C., 1Tunung, R., 1Jeyaletchumi, P., 1 Noor Hidayah, M. S., 1Ubong, A., 1Farinazleen, M. G., 2Cheah, Y. K. and 1*Son, R. 1 Center of Excellence for Food Safety Research, Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia 2 Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia 1 Abstract: Salmonellosis continues to be a major public health problem worldwide. It also contributes to negative economic impacts due to the cost of surveillance investigation, treatment and prevention of illness. As such, research on Salmonella has gained great interest and concern from scientists. The purpose of this review is to discuss the classification and nomenclature, characteristic, clinical manifestation, epidemiology, transmission vehicles, antibiotic resistance and quorum sensing of Salmonella. Keywords: Salmonella, clinical manifestation, epidemiology, transmission, antibiotic resistance, quorum sensing Introduction There are 16 million annual cases of typhoid fever, 1.3 billion cases of gastroenteritis and 3 million deaths worldwide due to Salmonella (Bhunia, 2008). In brief, Salmonella is facultative anaerobe, gramnegative flagellated rod-shaped bacterium which is about 2-3 x 0.4-0.6 µm in size (Yousef and Carlstrom, 2003; Montville and Matthews, 2008). It is among the most commonly isolated foodborne pathogens associated with fresh fruits and vegetables. In recent years, the incidence of foodborne outbreaks caused by the contamination of fresh fruits and vegetables has increased and become a great concern in industrialized countries. Outbreaks of salmonellosis have been linked to a wide variety of fresh fruits and vegetables including apple, cantaloupe, alfalfa sprout, mango, lettuce, cilantro, unpasteurized orange juice, tomato, melon, celery and parsley (Pui et al., 2011b). Classification and nomenclature Historically Salmonella had been named based on the original places of isolation such as Salmonella London and Salmonella Indiana. This nomenclature system was replaced by the classification based on the susceptibility of isolates to different selected bacteriophages which is also known as phage typing (Bhunia, 2008). Phage typing is generally employed when the origin and characteristic of an outbreak must be determined by differentiating the isolates of the same serotype. It is very reproducible when *Corresponding author. Email:
[email protected] Tel: +603-89468361; Fax: +603-89423552 international standard sets of typing phages are used. More than 200 definitive phage types (DT) have been reported so far. For example, S. Typhimurium DT104 designates a particular phage type for Typhimurium isolates (Hanes, 2003; Andrews and Baumler, 2005). Epidemiologic classification of Salmonella is based on the host preferences. The first group includes host-restricted serotypes that infect only humans such as S. Typhi. The second group includes host-adapted serotypes which are associated with one host species but can cause disease in other hosts serotypes such as S. Pullorum in avian. The third group includes the remaining serotypes. Typically, Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Heidelberg are the three most frequent serotypes recovered from humans each year (Gray and Fedorka-Cray, 2002; Boyen et al., 2008). Kauffmann-White scheme classifies Salmonella according to three major antigenic determinants composed of flagellar H antigens, somatic O antigens and virulence (Vi) capsular K antigens. This was adopted by the International Association of Microbiologists in 1934. Agglutination by antibodies specific for the various O antigens is employed to group Salmonellae into the 6 serogroups: A, B, C1, C2, D and E. For instance, S. Paratyphi A, B, C and S. Typhi express O antigens of serogroups A, B, C1 and D, respectively. More than 99% of Salmonella strains causing human infections belong to Salmonella enterica subspecies enterica. Although not common, cross-reactivity between O antigens of Salmonella and other genera of Enterobacteriaceae do occur. Therefore, further classification of serotypes is based © All Rights Reserved Bhunia. Farinazleen. Yousef and Carlstrom. bacteremia and other complications of nontyphoidal salmonellosis as well as chronic carrier state. The system is currently used by World Health Organization (WHO) Collaborating Centre. They are sensitive to heat and often killed at temperature of 70°C or above. R. Characteristic Salmonellae are non-fastidious as they can multiply under various environmental conditions outside the living hosts. Typhimurium. As an example. R. 2002). Pakistan and Middle East (Scherer and Miller. W. Salmonellae grow in a pH range of 4 to 9 with the optimum between 6. A. C. In recent years.8 or water activity <0. 2003. bongori are mainly isolated from cold-blooded animals and account for less than 1% of clinical isolates. 2003. G. the subspecies information is often omitted and culture is called S..0) yet can survive at aw <0. Roughly 10% of patients may relapse.4 to 4%. 2001). gastrointestinal bleeding and intestinal perforation... H antigens are heat-labile proteins associated with the peritrichous flagella and can be expressed in one of two phases. resistant to alcohol and dilute acids. is associated with high mortality. Wong.99 and 0. Hence. Salmonella enterica subspecies I is mainly isolated from warm-blooded animals and accounts for more than 99% of clinical isolates whereas remaining subspecies and S. The phase 1 H antigens are specific and associated with the immunological identity of the particular serovars whereas phase 2 antigens are non-specific antigens containing different antigenic subunit proteins which can be shared by many serovars. India. 2008). Bacteria can be classified based on phylogeny. C. B and C cause paratyphoid fever with symptoms which are milder and a mortality rate that is lower for the latter. 2008). C. In brief. Intestinal perforation may present with abdominal pain. Infection typically occurs due to ingestion of food or water contaminated with human waste. 2006).94 (Hanes.2 such as in dried foods.. particularly Southeast Asia. O antigens are lipopolysaccharide (LPS) of the outer bacterial membrane. Most Salmonella serotypes grow at temperature range of 5 to 47°C with optimum temperature of 35 to 37°C but some can grow at temperature as low as 2 to 4°C or as high as 54°C (Gray and Fedorka-Cray.5 and 7. and Son. Complete inhibition of growth occurs at temperatures <7°C. die or encounter serious complications such as typhoid encephalopathy. rising pulse and falling blood pressure in sick people. enterica serotype Typhimurium and in subsequent appearance. Bhunia. the clinical pattern of salmonellosis can be divided into four disease patterns namely enteric fever. Typhoid encephalopathy. 2003). Salmonella enterica is further divided into six subspecies. Both serotypes are solely human pathogens. 2005. They do not require sodium chloride for growth. They require high water activity (aw) between 0. They are heat stable. 2006. Parry. the Kauffmann species Salmonella typhimurium is now designated as Salmonella enterica subspecies I serotype Typhimurium. K antigens which are heat-sensitive carbohydrates are produced by Salmonella serovars that express a surface-bound polysaccharide capsular antigen (Hu and Kopecko. Tunung. Gastroenteritis Nontyphoidal salmonellosis or enterocolitis is caused by at least 150 Salmonella serotypes with Salmonella Typhimurium and Salmonella Enteritidis being the most common serotypes in the United International Food Research Journal 18: 465-473 . Centers for Disease Control and Prevention (CDC) and some other organizations.94 (pure water aw=1. often accompanied by shock. Jeyaletchumi.5.. There are 2463 Salmonella serotypes which are now placed under 2 species due to the difference in 16S rRNA sequence analysis: Salmonella enterica (2443 serotypes) and Salmonella bongori (20 serotypes). it is written as S.. M. Noor Hidayah. M.. L. Parry. Clinical manifestation In human disease. gastroenteritis. P. F. antibiotic-resistant strains have been isolated in most endemic areas. A phylogenetic tree can be derived from the comparison with 16S rRNA or other gene sequences. pH <3. Ubong. The comparison of characteristics of Salmonella species is indicated in Table 1. but can grow in the presence of 0. Chai. S. which are designated by roman numerals. Y. Cheah. 2001). Relapse is the most common occurrence probably due to persisting organisms within reticuloendothelial system (RES). Under the modern nomenclature system. Enteric fever Salmonella Typhi causes typhoid fever whereas Paratyphi A. it is very serious in 1 to 3% of hospitalized patients (Hu and Kopecko. This system of nomenclature is used nowadays to bring uniformity in reporting (Andrews and Baumler. K. Slight gastrointestinal bleeding can be resolved without blood transfusion but in 1 to 2% of cases can be fatal if a large vessel is involved.466 Pui. 2003. on the antigenicity of the flagellar H antigens which are highly specific for Salmonella (Scherer and Miller.. 7-1.5 d d + + + + + + + + + - 35-37 6.7-1. Hanes. Parry. It has been associated with highly invasive serotypes like Cholearaesuis or Dublin. different reactions given by different serovars States.5 0. Patients with bacteremia and other complications should be treated with antibiotics (Scherer and Miller. 2002. About 2 to 5% of untreated typhoid infections result in a chronic carrier state. enterica salamae I II WarmWarmblooded blooded animals animals arizonae IIIa Coldblooded animals & environment diarizonae IIIb Coldblooded animals & environment houtenae IV Coldb1ooded animals & environment indica VI Coldblooded animals & environment Salmonella bongori V (formerly) Coldblooded animals & environment + (except + + + + + pullorum & gallinarum) Rod Rod Rod Rod Rod Rod 0. Yousef and Carlstrom. The emergence of multidrug-resistant S. 2006).7-1. Antibiotic treatment is usually not advised except for rare cases because it can prolong the presence of bacteria in the stool (Gray and Fedorka-Cray. Bacteremia is a serious condition in which bacteria enter the bloodstream after passing through the intestinal barrier. when necessary.5-7.5-7.5 + + + + + d + + + + d d + - 35-37 6. 2003). Yousef and Carlstrom. Bacteremia and other complications of nontyphoidal salmonellosis About 8% of the untreated cases of salmonellosis result in bacteremia.1% of nontyphoidal Salmonella cases are shed in stool samples for periods exceeding 1 year. but nontyphoidal salmonellosis has increased worldwide. In production animals like swine.5-7. 2001. less than 10% positive reactions. 2002. 2001. 2003).5 + + + + + + + + + - 35-37 6. Typhimurium DT104 has been associated with outbreaks related to beef contamination and resulted in hospitalization rates twice than that of other foodborne salmonellosis (Gray and Fedorka-Cray.5 + + + + + + + + - 35-37 6. depending on the serotypes.5 0.5-7.5 2-5 Note: +. Comparison of characteristics of Salmonella species Characteristics Classification (roman numeral) Usual habitat Morphological characteristics Gram stain Motility Shape Size (width. Ciprofloxacin is often administered at the first sign of severe gastroenteritis whereas ceftriaxone is given to children with systemic salmonellosis. especially those who work in food-related industries. Infection always occurs via ingestion of water or food contaminated with animal waste rather than human waste. mostly with black centers (H2S producers) Colourless colonies on a pink background Black-centered red colonies (H2S producers) + 35-37 6.5 0.5 0. Only about 0. Bacteremia caused by Salmonella should be taken into account in cases of fever of unknown origin. nontyphoidal serotypes persist in the gastrointestinal tract from 6 weeks to 3 months. µm) Size (length. Chronic carrier state Salmonellosis can be spread by chronic carriers who potentially infect many individuals. more than 90% positive reactions.5-7.5-7. Factors contributing to the chronic carrier state have not been fully explained. d.7-1. -. µm) Colony morphologies Bismuth sulphite agar Eosin-methylene blue agar Hektoen enteric agar Salmonella-Shigella agar Xylose lysine desoxycholate agar Growth characteristics Optimum temperature (°C) Optimum pH Biochemical characteristics α-glutamyltransferase β-Gluocuronidase Dulcitol Galacturonate Gelatinase Glucose Hydrogen sulfide Indole test Lactose Lysine decarboxylase L(+)-tartrate Malonate Methyl red test Murate Ortho-nitrophenyl-β-DGalactopyranoside test Phage O1 susceptible Potassium cyanide broth Salicine Sorbitol Urease Voger-Proskauer test Salmonella enterica subsp.5 + + + + + + + + + + + + + + - 35-37 6.5 2-5 2-5 2-5 2-5 2-5 2-5 Black colonies surrounded by a brown to black zone that casts a metallic sheen Translucent amber to colourless colonies Blue to blue-green colonies.5 0. On average. treatment is usually contraindicated but. Typhoid fever usually causes mortality in 5 to 30% of typhoid-infected International Food Research Journal 18: 465-473 .5-7. can be given via injection with several treatment alternatives based on considerations such as withdrawal time. Epidemiology Typhoid cases are stable with low numbers in developed countries.7-1.5 + d d + + + + + + + + d + + - Rod 0.5 + d + + + + + + + + + + + - 35-37 6. Typhi in feces for 1 to 3 months and between 1 and 4% become chronic carriers excreting the microorganism for more than one year (Scherer and Miller.Salmonella: A foodborne pathogen 467 Table 1.7-1. 2003).7-1. Up to 10% of untreated convalescent typhoid cases will excrete S. C. approximately 2 to 4 million cases of Salmonella gastroenteritis occur with about 500 deaths per year. therefore infection can be happened by eating the improperly handled food by infected individuals (Newell et al.3 billion cases with 3 million deaths. Transmission vehicles Salmonella are widely distributed in nature and they survive well in a variety of foods. but can be as high as 5 to 7% despite the use of appropriate antibiotic treatment. Even though she was released with the stipulation that she never cook again. 2001. G. However. notification and isolation rate of salmonellosis in different part of the world is shown in Figure 1. single-food-source outbreaks indicate that as little as 1 to 10 cells can cause salmonellosis with more susceptibility to infection by YOPI groups (Yousef and Carlstrom. age and underlying illnesses or immune deficiencies. 2003. transmission of Salmonella to the food processing plants and equipments for food preparation are also of great importance. Some of the incidence. Salmonella is transmitted to vectors such as rats. Salmonella Typhi and Salmonella Paratyphi A do not have animal reservoir. she broke the promise and consequently caused at least 25 more cases of typhoid fever at Manhattan maternity hospital when she was employed as a cook in 1915.. Tunung. consumption by human can result in the risk of salmonellosis. host factors controlling susceptibility to infection include the condition of the intestinal tract. cows and chickens act as the important risk factor for infection. In the US and most of Europe. 2003). However. Following the direct transmission. Once carried by vectors or transferred to food. These animal reservoirs are infected orally because Salmonella normally originates from the contaminated environment and also contaminated feed. The infectious dose of Salmonella depends upon the serovar.. Africa and South and Central America where only 1 to 10% of cases are reported (Portillo.. After being apprehended by public health officials in 1907. Consequently. Salmonella can enter the food chain at any point from livestock feed. On the other hand.000 deaths. processing and retailing as well as catering and food preparation in the home (Wong et International Food Research Journal 18: 465-473 . A more accurate figure of salmonellosis is difficult to determine because normally only large outbreaks are investigated whereas sporadic cases are under-reported. A. fresh produce like fruits and vegetables have gained concern as vehicles of transmission where contamination can occur at multiple steps along the food chain (Bouchrif et al. The World Health Organization (WHO) estimates 16 to 17 million cases occur annually. flies and birds where Salmonella can shed in their faeces for weeks and even months. Chai. 2010). Ubong. Mary Mallon. 2000.. 2006) . Y.. Typhoid incidence in endemic areas is typically low in the first few years of life. growth condition and host susceptibility. W. Besides. nontyphoidal cases account for 1. R. First. F. In recent years..468 Pui. C. transmitted typhoid fever to at least 22 individuals causing 3 deaths between 1900 and 1907. Hu and Kopecko. Human get infected when eating the food or drinking the water that is contaminated with Salmonella through animal reservoirs. Noor Hidayah. Most infections occur in childhood especially in Mekong Delta region of Vietnam and are recognizable although often mild. M. P. R. L. S. Figure 1.. eggs and dairy products are the most common vehicles of salmonellosis. she was isolated for 3 years. Cheah.. some eastern and southern European countries and central and South America. C. The most famous outbreak of enteric fever is Typhoid Mary. Wong. K. Poultry. Some of the incidence and notification rate of enteric fever and sallmonellosis in different parts of the world Typhoid fever is endemic throughout Africa and Asia as well as persists in the Middle East. Data on salmonellosis are scarce in many countries of Asia.. 2003. through food manufacturing. Hanes. On the other hand. In the United States. Parry. moving animals such as swines. The Salmonella cells can attach to food contact surfaces such as plastic cutting board which may develop into biofilm once attached and hence cause cross-contamination. 2009). Farinazleen. Bhunia. Jeyaletchumi. and Son. 2008). The mortality rates differ from region to region. a New York City hired household cook. bacteria strain. The infectious dose of Salmonella is broad varying from 1 to 109 cfu/g. She was finally isolated until her death in 1938 (Scherer and Miller.. individual in the developing world. environment contaminated with Salmonella serves as the infection source because Salmonella can survive in the environment for a long time. typhoid is predominantly a disease of the returning traveler. peaking in school-aged children and young adults and then falling in middle age. After that. resulting in about 600. M. The consumption of unboiled Number of cases 272 9 2.. 2010 CDC. Bhunia.. 2007 D’Aoust and Maurer..4% chicken gizzard were contaminated with Salmonella spp. 2010 CDC. Contamination of eggs and particularly egg contents by S. Enteritidis are believed to be a cause of the large outbreak in Europe and North America since 1980s (Jay et al. In areas where typhoid fever is endemic.. 2007 Ling et al. (1995) reported 39. 2010). from wild animal feces or even from carcasses. Colorado and Minnesota from May 1 to August 31. Arumugaswamy et al. Salmonella Pullorum and Salmonella Gallinarum usually cause disease in poultry. cantaloupe from Mexico resulted in a Salmonella Poona outbreak in USA (Penteado and Leitão. Montville and Matthews. geese and ducks) as the main vehicles in the salmonellosis outbreak. 469 water during 1997 typhoid outbreak in Dushanbe. In Malaysia. Salmonella Infantis was the predominant serotype in Australian egg industry (Cox et al.3% chicken liver and 44. Disease surveillance reports frequently identify poultry (chickens. Sweden Singapore Japan France Switzerland Source Black and red pepper Frozen mamey fruit pulp Shell eggs Alfalfa sprouts Cereal from Malt-O-Meal Dry pet food Peanut butter Mixed salad Kebab Imported raw beef Stall food Cake/raw egg topping Lettuce Aniseed herbal tea Shandong peanuts Fish Dried anchovy Dried squid Mont D’or cheese Potato salad prepared by carrier Serotype Montevideo Typhi Enteritidis Saintpaul Agona Schwarzengrund Tennessee Enteritidis PT21 Enteritidis PT1 Typhimurium PT104 Typhi Enteritidis Newport Agona Stanley Livingstone Typhimurium DT104L Salmonella spp. The main food involved in salmonellosis is shown in Table 2. Examples of reported salmonellosis outbreak Year 2010 2010 2010 2009 2008 2007 2006 2005 2005 2005 2005 2004 2004 2003 2001 2001 2000 1999 1996 1994 Country United States United States United States United States United States United States United States Austria England The Netherlands Malaysia China Great Britain Germany Canada. 2007 Montville and Matthews. Salmonella spp. 2007 D’Aoust and Maurer. 2007 D’Aoust and Maurer. 2010 Montville and Matthews. 2008). Salmonella can enter eggs from the oviduct (particularly ducks).. 35. 2007). water from lakes or rivers which are used for public consumption and are sometimes contaminated by raw sewage are the main sources of infection. Typhi Apart from that. 2002). 2007). Anatum.. 2005 D’Aoust and Maurer. feed and litter as well as water troughs in the pens. Poor sanitation. Since then. Havana. 1997. improper sewage disposal and lack of clean water system cause the transmission of typhoid fever. Australia Norway. Table 3 indicated some of studies of the transmission vehicles related to Salmonella spp. Emerging resistance in Salmonella Typhi has been described especially in Africa and Asia and the appearance of Salmonella Typhimurium DT104 in the late 1980s raised main public health concern. turkeys. 2010 CDC.. 2007 D’Aoust and Maurer. Penetration into the egg is increased when the cuticle is damaged. United Kingdom and other countries of the world. Spread of Salmonella may be facilitated in water storage tanks in a building. 2008). Tajikistan caused 2200 cases of illness and 95 deaths. chloramphenicol and trimethoprim-sulfamethoxazole define multidrug resistance (MDR) in Salmonella enterica (Crump and Mintz. the US Centers for Disease Control and Prevention (CDC) mentioned that there were approximately 1469 illnesses associated with eggs infected by Salmonella Enteritidis reported in California. outside of the egg is wet. Cox and Pavic (2010) provided extensive overview on poultry meat production associated with Salmonella and discussed the approaches for the control of this pathogen throughout the whole production chain as poultry can be contaminated from breeder flocks. 2008 Colak et al. The human health risk is increased further by Salmonella preference to grow on fresh produce during retail display at ambient temperature. 1998. This is of great concern because majority infections with MDR Salmonella are acquired through the consumption of contaminated foods of animal origin such as swines and chicken International Food Research Journal 18: 465-473 . natural uptake through root systems and transfer onto edible plant tissues during slicing. the isolation frequency of Salmonella strains resistant to one or more antibiotics have increased in the Saudi Arabia.Salmonella: A foodborne pathogen al. Salmonella contamination of fresh produce could be due to the entry of Salmonella through scar tissues. temperature is decreased and specific gravity of the shell is low. 2010. 2010 CDC.. On the other hand. 2002). Recently. (2007) stated that multi-resistance occurred in Salmonella serotypes including Albany.752 235 28 62 >288 85 195 165 171 197 >350 42 93 60 33 <453 14 10 Reference CDC. Yoke-Kqueen et al. Antibiotic resistance The resistance of Salmonella to a single antibiotic was first reported in the early 1960s (Montville and Table 2. The resistance towards the traditional first-line antibiotics such as ampicillin. 2008). 2004. 2002 Montville and Matthews.. Bordini et al. 1998. 1997 Matthews. London and Typhimurium. In 2000. Van et al. 2010 CDC. entrapment during embryogenesis of produce. 2008 D’Aoust and Maurer. 2008 D’Aoust and Maurer. 2007 Nik and Sharifah. 2007 Gruner et al. thereby threatening the lives of infected individuals (Grob et al. hatchery environment. This is due to the increased and uncontrolled use as well as easy accessibility to antibiotics in many countries of the world (Grob et al. United States..4% chicken portions. . 2006 Malkawi and Gharaibeh.2%) 8/26 (30. Hadar. (2011a). Due to the use of antibiotics for the promotion of growth and prevention of disease in food animals. Braenderup.7%) 25/93 (26. Typhimurium.5%) chick egg retail pork chicken part minced meat ready-to-eat salad raw vegetable raw milk raw poultry cooked poultry raw meat cooked meat turkey quail vegetable faeces caecum dust water tulum cheese pork beef chicken shellfish street food fried chicken kerabu jantung pisang sambal fish mix vegetable chicken abattoir egg chicken. C. Typhimurium Colak et al. 2009 Prendergast et al. Blockley Blockley. Mgulani. Choleraesuis have been identified in swines in Taiwan and Thailand.8%) 276/515 (53. is the mechanism that involves the bacteria synthesis. extracellular polymer production.. bacteria sense its presence and start the signalling cascade which results in the changes of target gene expression (Gobbetti et al. antibiogram testing by Singh et al.. Typhi.7%) 16/80 (20%) 75/105 (71. Y.3%) 4/16 (25%) 2/19 (10. secretion and detection of hormone-like molecules known as autoinducers (Elvers and Park. Bredeney. chicken. An example of the traits under quorum sensing is biofilm formation by Salmonella Typhi and Salmonella Typhimurium on plastic cutting board as reported by Pui et al. Typhimurium Enteritidis. 2010) to ensure the effectiveness of control programmes.. surface attachment as well as secretion of nutrient sequestering compounds and virulence factors (Nadell et al. Albany. also known as cell-to-cell communication. (2007) International Food Research Journal 18: 465-473 . Finally. 1997 Rusul et al. from different sources Country Iran Brazil Spain China Morocco Bangladesh Republic of Ireland Turkey Iran Lithuania Turkey Vietnam Malaysia Brazil South India Jordan Malaysia Albania India Malaysia Malaysia Sample/source chicken beef poultry carcass poultry viscera pig herd chicken pork beef lamb slaughter house seafood Prevalence 86/190 (45..5%) 8/40 (20. Enteritidis. Traits under quorum-sensing control include antibiotic biosynthesis.6%) 28/91 (30. Typhimurium Pieskus et al.. 2010 Enteritidis Freitas et al. . 1996 eggs.. Reading and Sperandio. Muenchen. 2009 Enteritidis. Table 3. Mbandaka..6%) 3/5 (60.7%) 1/10 (10%) 6/250 (2.4%) 158/445 (35...7%) 1/3 (33..3%) 9/50 (18%) 12/129 (9. C..3%) 14/60 (23. and Son. Agona.6%) 1/168 (0.8%) 8/25 (32%) 8/18 (44.5%) 104/730 (14. K. Derby. there is an increase of human salmonellosis cases caused by foodborne MDR Salmonella nowadays (Yang et al. biosurfactant synthesis. Tunung. 2002..0%) 6/9 (66. G.4%) 10/105 (9. Kentucky. Chincol. Havana.. 2010 Infantis. 2008 London.470 Pui.9%) 2/118 (1. Senftenberg..4%) 30/461 (6.4%) 6/17 (35.4%) 32/50 (64%) 31/50 (62%) 16/30 (53. M. bioluminescence. R. 2006 Suresh et al. 2008 Arumugaswamy et al. 2010 Enteritidis. 2008). Typhimurium Enteritidis Enteritidis.1%) 38/492 (7. Jimenez-Gomez et al.4%) 4/28 (14. Weltevreden Tunung et al. Typhimurium Gomez-Laguna et al.5%) Predominant serotypes Thompson Reference Dallal et al. Prevalence of Salmonella spp. Djugu Yang et al. Apart from that.. Baibouknown Jalali et al. meat selom pegaga kangkong kesum chicken meat sample fish crustacean retail poultry litter poultry farm chicken portion chicken liver chicken gizzard cooked meat.7%) 2/5 (40..0%) 2/10 (20. Wong. Cheah. 2003 Enteritidis Weltevreden. Asai et al.0%) 29/288 (10. 2007 Biafra.3%) 8/18 (44.. Indiana.. Noor Hidayah. Anatum.4%) 8/101 (7. Kiambu Typhimurium Typhimurium Infantis Bouchrif et al. Branderup II. Albany Cortez et al.1%) 5/34 (14.8%) 13/78 (16.. P...9%) 3/56 (5. Chai.1%) 0/127 (0%) 2/73 (2. there is a need of continuous surveillance and sharing of antimicrobial susceptibility data for Salmonella among countries worldwide (de Oliveira et al. sporulation.3%) 38/189 (20. M. A. W.9%) 28/85 (32.. Jeyaletchumi. 2007). This indiscriminate and injudicious use of antibiotics in any setting especially in food animals worldwide should be monitored to reduce the transfer risk of MDR Salmonella to humans (Zhao et al.3%) 22/67 (32.3%) 2/5 (40%) 3/38 (7. 2003). Once the signal molecule achieves the critical threshold concentration...3%) 48/276 (17. S. colistin and polymyxin-B. 2008 Enteritidis. Paratyphi B. 1995 Quorum sensing Quorum sensing.3%) 1/18 (5.7%) 43/804 (5. 2009 Cetinkaya et al. Ubong.9%) 12/52 (23. 2010 Anatum. 2006). 2004 Salleh et al. (2010) mentioned that cephalosporinand fluoroquinone-resistant strains of S. 2007 Enteritidis.. Agona Beli et al. 2010). 2007 Van et al. Farinazleen. Hasan et al. 2001 Hatha and Lakshamanaperumalsamy... Shubra.. Quorum sensing in Salmonella involves LuxS/ AI-2 system which is the most widespread quorum sensing system. L. R.6%) 0/45 (0%) 0/100 (0%) 0/78 (0%) 0/25 (0%) 24/134 (17.0%) 13/33 (39. Muenchen. (2010) revealed Salmonella isolates from chicken eggs in marketing channels and poultry farms in North India were resistant to bacitracin. F. vegetable satay prawn oriental shrimp paste 4/80 (5%) 13/500 (2... Typhimurium. C. Blokley.9%) 16/43 (37. Typhimurium Weltevreden. and Baumler. Arumugaswamy. pathogenesis and control... Asai.2008. 2008... It is the enzyme LuxS which takes part in the metabolism of S-adenosylmethionine (SAM) to produce the by-product.. C. A. H. 2006. Colak.1016/j. Prevalence and antimicrobial resistance profiles of Salmonella serotypes. Iran. and Levent. K.1016/j. M. Epidemiological Summary of Typhoid Fever in California. M. Bhunia. doi:10. Bordini. Cortez. D. Toshiya. and Vidal-Martins. F. T. P. S. 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