<i>Salmonella</i>Detection Methods

Maddox, Carol W.

doi:10.1002/9780470752616.ch10

Cited by 5 publications

(4 citation statements)

References 34 publications

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“…Salmonellosis is the leading most common foodborne zoonoses (Acha and Szyfres 2001;Maddox 2003) caused by organisms of the genus Salmonella (Radostits et al 2007). Non-typhoidal Salmonella represents an important human and animal pathogen worldwide (Hoelzer et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Prevalence and antimicrobial resistance profiles of Salmonella enterica serovars isolated from slaughtered cattle in Bahir Dar, Ethiopia

Alemu

Zewde

2011

Trop Anim Health Prod

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A study was undertaken from October 2006 to March 2007 to determine the prevalence and antimicrobial resistance patterns of Salmonella serovars. Liver, mesenteric lymph nodes, intestinal content, and carcass swab samples (each n = 186) were collected from 186 apparently healthy slaughtered cattle at Bahir Dar abattoir. Bacteriological analysis was done according to the International Organization for Standardization (ISO 6579 2002). Isolates were serotyped at Agence Française de Securite Sanitaire des Aliments, Cedex, France. Twenty-eight isolates consisting of Salmonella Typhimurium, Salmonella Newport, Salmonella Haifa, Salmonella Heidelberg, Salmonella Infantis, and Salmonella Mishmarhaemek were identified. Salmonella Typhimurium and Salmonella Newport were most frequently isolated while Salmonella Heidelberg and Salmonella Mishmarhaemek were isolated least. Eleven of the 28 (39.3%) were resistant to one or more of the antimicrobials tested. Resistance was shown to ampicillin, chloramphenicol, gentamycin, norfloxacin, polymyxin-B, streptomycin, tetracycline, and trimethoprim. Four of 11 (36.4%) were multiple antimicrobial resistant. All the isolates tested were susceptible to the antimicrobial effects of gentamycin, norfloxacin, and trimethoprim. Eleven, four, and two isolates of the 28 were resistant to streptomycin, tetracycline, and ampicillin, respectively. All isolates of Salmonella Infantis, Salmonella Typhimurium (except one), and Salmonella Mishmarhaemek were susceptible to the tested antimicrobials. One Typhimurium isolate was resistant to chloramphenicol, streptomycin, and tetracycline. Salmonella Haifa was multiply antimicrobial resistant to ampicillin, tetracycline, and streptomycin. All isolates of Salmonella Heidelberg were resistant to streptomycin. Results of this study indicated high level of carcass contamination with antimicrobial-resistant Salmonella serovars which could pose public health risk; suggests need for hygienic slaughtering operations and proper cooking of meat before consumption. Further detailed studies involving different abattoirs, animal products, food items, and animals on different settings were recommended in the study area.

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Section: Introductionmentioning

confidence: 99%

Prevalence and antimicrobial resistance profiles of Salmonella enterica serovars isolated from slaughtered cattle in Bahir Dar, Ethiopia

Alemu

Zewde

2011

Trop Anim Health Prod

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“…In conventional methods, the detection of pathogenic bacteria in foods involves several steps and needs several days to complete. For Salmonella detection, pre-enrichment (16-20 h), selective enrichment (18-48 h), plating on selective/differential agar media (24-48 h) and biochemical and serological identification (4-48 h) steps are needed (Maddox 2003). Similarly, detection methods for Listeria (Wesley et al 2003) and pathogenic E. coli cells (Moxley 2003) are also time-consuming.…”

Section: Introductionmentioning

confidence: 99%

Effect of environmental stresses on antibody-based detection of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis and Listeria monocytogenes

Hahm

Bhunia

2006

J Appl Microbiol

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Aims: To study the reaction patterns of selected antibodies to Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis and Listeria monocytogenes cells exposed to various environmental stresses. Methods and Results: Escherichia coli O157:H7, Salmonella Enteritidis and L. monocytogenes cells subjected to different environmental stress of temperatures (4 and 45°C), NaCl (5·5%), oxidative stress (15 mmol−1 H2O2), acidic pH (5·5) and ethanol (5%) for 3 h (short‐term stress) or for 5 days (long‐term stress) were analysed by ELISA and Western blotting. The ELISA results indicated that most stresses caused 12–16% reductions in reaction for anti‐E. coli O157:H7 and 20–48% reductions for anti‐Salmonella polyclonal antibodies during short‐term stress, whereas the most stresses exhibited enhanced reaction (44–100% increase) with the anti‐L. monocytogenes polyclonal antibody. During long‐term stress exposure to combined stress conditions of pH 5·5, 3·5% NaCl at 12°C or at 4°C, antibody reactions to the three pathogens were highly variable with the combined stress at 4°C showing the most reductions (8–40%). Likewise, there were about 18–59% reductions in antibody reactions with pathogens when cultured in hotdog samples with the combined stress conditions. Western blot analyses of crude cell surface antigens from both short‐ and long‐term stressed cells revealed that the changes in antibody reactions observed in ELISA were either because of repression, expression or possible denaturation of antigens on the surface of cells. Conclusions: Overall, the antibody reactions were significantly reduced in pathogens exposed to both short‐ and long‐term environmental stresses in culture medium or in meat sample because of expression, repression or denaturation of specific antigens in cells. Significance and Impact of the Study: In order to ensure the reliable detection of foodborne pathogens using antibody‐based methods, the influence of stress on antibody reactions should be thoroughly examined and understood first as the physiological activities in cells are often altered in response to a stress.

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“…Reports from the literature suggest that IMS‐based protocols should provide an advantage for detecting low concentrations of Salmonella (Benoit and Donahue 2003; Maddox 2003). The challenge is how to exploit this superiority in an affordable way given that the immune capture process involves added cost.…”

Section: Discussionmentioning

confidence: 99%

The relationship between concentration of a dual marker strain of Salmonella Typhimurium in bovine faeces and its probability of detection by immunomagnetic separation and culture

et al. 2004

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Aims: To modify a strain of Salmonella serotype Typhimurium to express unique marker traits and then define how the concentration of the marker in bovine faeces affects the probability of its detection by culture preceded by immunomagnetic separation (IMS). Methods and Results: DNA encoding for the production of green fluorescent protein (gfp) and resistance to kanamycin was inserted into the bacterial chromosome of Salm. Typhimurium. Transposon insertion was demonstrated by Southern blot hybridization. Varying amounts of one electroporant (gfpSal-1) were inoculated into suspensions of bovine faeces and attempts made to isolate gfpSal-1 using a protocol based on pre-enrichment incubation, IMS and enrichment in selective media. Isolates of gfpSal-1 were differentiated from wild strains of Salmonella using fluorescence under u.v. light and expression of kanamycin resistance. A logistic and Gompertz function each derived from the dose-response data partially explained the observations with the fit of the Gompertz function judged to be superior. The 10, 50 and 90% limits of detection from the Gompertz function were estimated to be 1AE92, 2AE03 and 2AE27 CFU g)1 respectively. Conclusions:Reliance on the traditional concept of Ôlimit of detectionÕ could introduce unacceptable errors in the interpretation of test findings when the concentration of Salm. Typhimurium in bovine faeces (pooled or individual) is below ca 3 CFU g )1 of faeces.Significance and Impact of the Study: The dose-response curve can be used to aid the design of protocols for detecting Salmonella in individual and pooled faecal specimens. The experiments demonstrate that both reporter genes in tandem are useful for studying the performance of culture-based methods for detecting pathogens in faeces.

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SalmonellaDetection Methods

Cited by 5 publications

References 34 publications

Prevalence and antimicrobial resistance profiles of Salmonella enterica serovars isolated from slaughtered cattle in Bahir Dar, Ethiopia

Prevalence and antimicrobial resistance profiles of Salmonella enterica serovars isolated from slaughtered cattle in Bahir Dar, Ethiopia

Effect of environmental stresses on antibody-based detection of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis and Listeria monocytogenes

The relationship between concentration of a dual marker strain of Salmonella Typhimurium in bovine faeces and its probability of detection by immunomagnetic separation and culture

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