Aptamer based SERS detection of Salmonella typhimurium using DNA-assembled gold nanodimers.

PubMed

Xu, Xumin; Ma, Xiaoyuan; Wang, Haitao; Wang, Zhouping

2018-06-12

The authors describe a surface-enhanced Raman scattering (SERS) based aptasensor for Salmonella typhimurium (S. typhimurium). Gold nanoparticles (AuNPs; 35 nm i.d.) were functionalized with the aptamer (ssDNA 1) and used as the capture probe, while smaller (15 nm) AuNPs were modified with a Cy3-labeled complementary sequence (ssDNA 2) and used as the signalling probe. The asymmetric gold nanodimers (AuNDs) were assemblied with the Raman signal probe and the capture probe via hybridization of the complementary ssDNAs. The gap between two nanoparticles is a "hot spot" in which the Raman reporter Cy3 is localized. It experiences a strong enhancement of the electromagnetic field around the particle. After addition of S. typhimurium, it will be bound by the aptamer which therefore is partially dehybridized from its complementary sequence. Hence, Raman intensity drops. Under the optimal experimental conditions, the SERS signal at 1203 cm -1 increases linearly with the logarithm of the number of colonies in the 10 2 to 10 7  cfu·mL -1 concentration range, and the limit of detection is 35 cfu·mL -1 . The method can be performed within 1 h and was successfully applied to the analysis of spiked milk samples and performed very well and with high specificity. Graphical abstract DNA-assembled asymmetric gold nanodimers (AuNDs) were synthesized and appllied in a SERS-based aptasensor for S. typhimurium. Capture probe was preferentially combined with S. typhimurium and the structure of the AuNDs was destroyed. The "hot spot" vanished partly, this resulting in the decreased Raman intensity of Cy3.

Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia.

PubMed

Budiati, Titik; Rusul, Gulam; Wan-Abdullah, Wan Nadiah; Chuah, Li-Oon; Ahmad, Rosma; Thong, Kwai Lin

2016-04-01

A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds.

A Novel Chromogenic Ester Agar Medium for Detection of Salmonellae

PubMed Central

Cooke, Venitia M.; Miles, R. J.; Price, R. G.; Richardson, A. C.

1999-01-01

A novel agar medium, chromogenic Salmonella esterase (CSE) agar, for the differentiation of salmonellae is described. The agar contains peptones and nutrient extracts together with the following (grams per liter unless otherwise specified): 4-[2-(4-octanoyloxy-3,5-dimethoxyphenyl)-vinyl]-quinolinium-1-(propan-3-yl carboxylic acid) bromide (SLPA-octanoate; bromide form), 0.3223; lactose, 14.65; trisodium citrate dihydrate, 0.5; Tween 20, 3.0; ethyl 4-dimethylaminobenzoate, 0.035% (wt/vol), novobiocin, 70 mg liter−1. The key component of the medium is SLPA-octanoate, a newly synthesized ester formed from a C8 fatty acid and a phenolic chromophore. In CSE agar, the ester is hydrolyzed by Salmonella spp. to yield a brightly colored phenol which remains tightly bound within colonies. After 24 h of incubation at 37 or 42°C, colonies of typical Salmonella spp. were burgundy colored on a transparent yellow background, whereas non-Salmonella spp. were white, cream, yellow or transparent. CSE agar was evaluated by using a panel of strains including a high proportion of Salmonella and non-Salmonella strains giving atypical reactions on other differential agars. The sensitivity (93.1%) of CSE agar for non-typhi salmonellae compared favorably with those of Rambach (82.8%), xylose-lysine-deoxycholate (XLD; 91.4%), Hektoen-enteric (89.7%), and SM ID (91.4%) agars. The specificity (93.9%) was also comparable to those of other Salmonella media (SM ID agar, 95.9%; Rambach agar, 91.8%; XLD agar, 91.8%; Hektoen-enteric agar, 87.8%). Strains of Citrobacter freundii and Proteus spp. giving false-positive reactions with other media gave a negative color reaction on CSE agar. CSE agar enabled the detection of >30 Salmonella serotypes, including agona, anatum, enteritidis, hadar, heidelberg, infantis, montevideo, thompson, typhimurium, and virchow, which accounted for 91.8% of the salmonella isolates recorded by the Public Health Laboratory Service (Colindale, London, England) for 1997

Distribution of Salmonella serovars and phage types on 80 Ontario swine farms in 2004

PubMed Central

Farzan, Abdolvahab; Friendship, Robert M.; Dewey, Catherine E.; Muckle, Anne C.; Gray, Jeff T.; Funk, Julie

2008-01-01

The objective of this study was to describe the distribution of Salmonella spp. on Ontario grower–finisher pig farms. Eighty swine farms were visited from January through July 2004. On each farm, fecal samples were collected from 5 pens, 2 rectal samples and 1 pooled sample from fresh manure on the floor per pen. Salmonella was isolated from 91 (11%) of the 800 rectal samples and 73 (18%) of the 397 pooled samples. Overall, Salmonella was recovered from 37 (46%) of the 80 farms. On each positive farm, Salmonella was cultured from 1 to 7 pigs or 1 to 5 pens. Of the 37 farms, 18, 13, 5, and 1 yielded 1, 2, 3, and 4 serovars, respectively. The most common serovars were S. Typhimurium var. Copenhagen, S. Infantis, S. Typhimurium, S. Derby, S. Agona, S. Havana, and S. enterica subsp. I:Rough-O. The 3 most frequent phage types were PT 104, PT 104a, and PT 104b. There was a statistically fair agreement between samples collected directly from pigs and pooled pen samples in determining the Salmonella status at the pen and farm level (κ = 0.6, P < 0.0001). However, in 62 pens, Salmonella status, serovars, or phage types differed between the pig and pooled pen samples. The distribution of Salmonella on the swine farms in this study indicates that, in developing an intervention strategy, priority should be given to farms positive for S. Typhimurium var. Copenhagen. Also, the variation in Salmonella status between pig and pooled pen samples deserves consideration in a sampling strategy. PMID:18214155

SERS Technique for Rapid Bacterial Screening

USDA-ARS?s Scientific Manuscript database

This study reports the feasibility of citrate-reduced colloidal silver SERS for differentiating E. coli, Listeria, and Salmonella. FT-Raman and SERS spectra of both silver colloids and colloid-K3PO4 mixtures were collected and analyzed to evaluate the reproducibility and stability of silver colloids...

Salmonella Species' Persistence and Their High Level of Antimicrobial Resistance in Flooded Man-Made Rivers in China.

PubMed

Song, Qifa; Zhang, Danyang; Gao, Hong; Wu, Junhua

2018-05-11

Man-made rivers, owing to proximity to human habitats, facilitate transmission of salmonellosis to humans. To determine the contamination situation by Salmonella in flooded man-made rivers and thereafter the exposure risk to public health, we investigated the prevalence of Salmonella species and their antimicrobial resistance in such rivers, as well as the relationship between the incidence of local infectious diarrhea cases and the number of Salmonella isolates from patients. After a heavy flood, 95 isolates of 13 Salmonella serotypes were isolated from 80 river water samples. The two most prevalent serotypes were Typhimurium and Derby. Eight Salmonella serotypes were newly detected after the flood. Overall, 50 isolates were resistant to ampicillin and/or cefotaxime and carried at least bla TEM . Twelve isolates of serotypes Typhimurium, Derby, Rissen, and Indiana were extended-spectrum β-lactamase (ESBL) producing and carried at least one of bla OXA and bla CTX-M-like genes. Twelve isolates of serotypes Typhimurium, Derby, Agona, Rissen, and Indiana were resistant to ciprofloxacin and had gyrA mutations. Isolates of Typhimurium, Derby, and Indiana were concurrently ciprofloxacin resistant and ESBL producing. Pulsed-field gel electrophoresis illustrates the circulation of two dominant clones of Salmonella Typhimurium isolates among patients, river, and food. High prevalence of various highly pathogenic and antimicrobial-resistant Salmonella serotypes shows that man-made rivers are prone to heavy contamination with Salmonella, and as a result put public health at greater risk.

Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia

PubMed Central

Thung, Tze Y.; Radu, Son; Mahyudin, Nor A.; Rukayadi, Yaya; Zakaria, Zunita; Mazlan, Nurzafirah; Tan, Boon H.; Lee, Epeng; Yeoh, Soo L.; Chin, Yih Z.; Tan, Chia W.; Kuan, Chee H.; Basri, Dayang F.; Wan Mohamed Radzi, Che W. J.

2018-01-01

The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect Salmonella spp., S. Enteritidis and S. Typhimurium in the meat samples. The prevalence of Salmonella spp., S. Enteritidis and S. Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of <3 to 15 MPN/g. Eight different serovars of Salmonella were identified among the 23 isolates, and S. Agona was the predominant serovar (26.09%). Interestingly, all the Salmonella isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two S. Typhimurium isolates (8.70%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all Salmonella isolates (100%) were positive for the invA gene. Meanwhile, pefA was only identified in S. Enteritidis and S. Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR) Salmonella and various virulence genes are present among the isolated Salmonella serovars. PMID:29379488

Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia.

PubMed

Thung, Tze Y; Radu, Son; Mahyudin, Nor A; Rukayadi, Yaya; Zakaria, Zunita; Mazlan, Nurzafirah; Tan, Boon H; Lee, Epeng; Yeoh, Soo L; Chin, Yih Z; Tan, Chia W; Kuan, Chee H; Basri, Dayang F; Wan Mohamed Radzi, Che W J

2017-01-01

The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect Salmonella spp., S . Enteritidis and S . Typhimurium in the meat samples. The prevalence of Salmonella spp., S . Enteritidis and S . Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of <3 to 15 MPN/g. Eight different serovars of Salmonella were identified among the 23 isolates, and S . Agona was the predominant serovar (26.09%). Interestingly, all the Salmonella isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two S . Typhimurium isolates (8.70%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all Salmonella isolates (100%) were positive for the invA gene. Meanwhile, pefA was only identified in S . Enteritidis and S . Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR) Salmonella and various virulence genes are present among the isolated Salmonella serovars.

Distribution and Antimicrobial Susceptibility of Foodborne Salmonella Serovars in Eight Provinces in China from 2007 to 2012 (Except 2009).

PubMed

Wang, Yin; Cao, Chenyang; Alali, Walid Q; Cui, Shenghui; Li, Fengqin; Zhu, Jianghui; Wang, Xin; Meng, Jianghong; Yang, Baowei

2017-07-01

One thousand four hundred ninety-one Salmonella isolates recovered from retail foods including chicken, beef, fish, pork, dumplings, and cold dishes in China in 2007, 2008, 2010, 2011, and 2012 were analyzed for distribution of serotype and antimicrobial susceptibility. A total of 129 Salmonella serotypes were detected among 1491 isolates. Salmonella Enteritidis (21.5%), Typhimurium (11.0%), Indiana (10.8%), Thompson (5.4%), Derby (5.1%), Agona (3.8%), and Shubra (3.0%) were the seven most important serotypes in 1491 isolates. For antibiotic susceptibility, except 16 (1.1%) isolates were susceptible to all tested antibiotics, 131 (8.8%) resisted 1-2 and 1344 (90.1%) resisted three or more antibiotics. One thousand forty-six (70.2%) of 1491 Salmonella isolates were identified as multidrug-resistant (MDR) isolates, which could resist three or more categories of antibiotics. Resistance to sulfisoxazole (78.1%) was most common among the tested Salmonella, followed by tetracycline (70.6%), trimethoprim/sulfamethoxazole (68.0%), and nalidixic acid (63.4%). Resistances to amikacin (20.0%), levofloxacin (18.7%), gatifloxacin (17.9%), ceftriaxone (17.7%), and cefoxitin (13.2%) were less frequently detected. Resistance to fluoroquinolones was most common among Salmonella Shubra and Indiana isolates, while resistance to cephalosporins was frequently detected among Salmonella Thompson isolates. The results highlighted the diversity of Salmonella serotypes and the high prevalence of Salmonella MDR isolates in China. Compared with Salmonella Enteritidis and Typhimurium isolates, the higher fluoroquinolones and cephalosporins resistance rates of some individual serotypes (Salmonella Shubra, Indiana, and Thompson) also provided more information for further study related to fluoroquinolones or cephalosporin-resistant Salmonella.

Salmonella survival in manure-treated soils during simulated seasonal temperature exposure.

PubMed

Holley, Richard A; Arrus, Katia M; Ominski, Kimberly H; Tenuta, Mario; Blank, Gregory

2006-01-01

Addition of animal manure to soil can provide opportunity for Salmonella contamination of soil, water, and food. This study examined how exposure of hog manure-treated loamy sand and clay soils to different simulated seasonal temperature sequences influenced the length of Salmonella survival. A six-strain cocktail of Salmonella serovars (Agona, Hadar, Heidelberg, Montevideo, Oranienburg, and Typhimurium) was added to yield 5 log cfu/g directly to about 5 kg of the two soils and moisture adjusted to 60 or 80% of field capacity (FC). Similarly, the Salmonella cocktail was mixed with fresh manure slurry from a hog nursery barn and the latter added to the two soils at 25 g/kg to achieve 5 log cfu/g Salmonella. Manure was mixed either throughout the soil or with the top kilogram of soil and the entire soil volume was adjusted to 60 or 80% FC. Soil treatments were stored 180 d at temperature sequences representing winter to summer (-18, 4, 10, 25 degrees C), spring to summer (4, 10, 25, 30 degrees C), or summer to winter (25, 10, 4, -18 degrees C) seasonal periods with each temperature step lasting 45 d. Samples for Salmonella recovery by direct plating or enrichment were taken at 0, 7, and 15 d post-inoculation and thereafter at 15-d intervals to 180 d. Salmonella numbers decreased during application to soil and the largest decreases occurred within the first week. Higher soil moisture, manure addition, and storage in the clay soil increased Salmonella survival. Salmonella survived longest (> or = 180 d) in both soils during summer-winter exposure but was not isolated after 160 d from loamy sand soil exposed to other seasonal treatments. For all but one treatment decimal reduction time (DRT45d) values calculated from the first 45 d after application were < or = 30 d and suggested that a 30-d delay between field application of manure in the spring or fall and use of the land would provide reasonable assurance that crop and animal contamination by Salmonella would be

Influence of Environmental Factors and Human Activity on the Presence of Salmonella Serovars in a Marine Environment

PubMed Central

Martinez-Urtaza, Jaime; Saco, Montserrat; de Novoa, Jacobo; Perez-Piñeiro, Pelayo; Peiteado, Jesus; Lozano-Leon, Antonio; Garcia-Martin, Oscar

2004-01-01

The temporal and spatial distribution of Salmonella contamination in the coastal waters of Galicia (northwestern Spain) relative to contamination events with different environmental factors (temperature, wind, hours of sunlight, rainfall, and river flow) were investigated over a 4-year period. Salmonellae were isolated from 127 of 5,384 samples of molluscs and seawater (2.4%), and no significant differences (P < 0.05) between isolates obtained in different years were observed. The incidence of salmonellae was significantly higher in water column samples (2.9%) than in those taken from the marine benthos (0.7%). Of the 127 strains of Salmonella isolated, 20 different serovars were identified. Salmonella enterica serovar Senftenberg was the predominant serovar, being represented by 54 isolates (42.5%), followed by serovar Typhimurium (19 isolates [15%]) and serovar Agona (12 isolates [9.4%]). Serovar Senftenberg was detected at specific points on the coast and could not be related to any of the environmental parameters analyzed. All serovars except Salmonella serovar Senftenberg were found principally in the southern coastal areas close to the mouths of rivers, and their incidence was associated with high southwestern wind and rainfall. Using multiple logistic regression analysis models, the prevalence of salmonellae was best explained by environmental parameters on the day prior to sampling. Understanding this relationship may be useful for the control of molluscan shellfish harvests, with wind and rainfall serving as triggers for closure. PMID:15066800

Isolation and identification of Salmonella spp. in drinking water, streams, and swine wastewater by molecular techniques in Taiwan

NASA Astrophysics Data System (ADS)

Kuo, C.; Hsu, B.; Shen, T.; Tseng, S.; Tsai, J.; Huang, K.; Kao, P.; Chen, J.

2013-12-01

Salmonella spp. is a common water-borne pathogens and its genus comprises more than 2,500 serotypes. Major pathogenic genotypes which cause typhoid fever, enteritis and other intestinal-type diseases are S. Typhimurium, S. Enteritidis, S. Stanley, S. Agona, S.Albany, S. Schwarzengrund, S. Newport, S. Choleraesuis, and S. Derby. Hence, the identification of the serotypes of Salmonella spp. is important. In the present study, the analytical procedures include direct concentration method, non-selective pre-enrichment method and selective enrichment method of Salmonella spp.. Both selective enrichment method and cultured bacteria were detected with specific primers of Salmonella spp. by polymerase chain reaction (PCR). At last, the serotypes of Salmonella were confirmed by using MLST (multilocus sequence typing) with aroC, dnaN, hemD, hisD, purE, sucA, thrA housekeeping genes to identify the strains of positive samples. This study contains 121 samples from three different types of water sources including the drinking water (51), streams (45), and swine wastewater (25). Thirteen samples with positive invA gene are separated from culture method. The strains of these positive samples which identified from MLST method are S. Albany, S. Typhimurium, S. Newport, S. Bareilly, and S. Derby. Some of the serotypes, S. Albany, S. Typhimurium and S. Newport, are highly pathogenic which correlated to human diarrhea. In our results, MLST is a useful method to identify the strains of Salmonella spp.. Keywords: Salmonella, PCR, MLST.

Detection and Identification of Salmonella spp. in Surface Water by Molecular Technology in Taiwan

NASA Astrophysics Data System (ADS)

Tseng, S. F.; Hsu, B. M.; Huang, K. H.; Hsiao, H. Y.; Kao, P. M.; Shen, S. M.; Tsai, H. F.; Chen, J. S.

2012-04-01

Salmonella spp. is classified to gram-negative bacterium and is one of the most important causal agents of waterborne diseases. The genus of Salmonella comprises more than 2,500 serotypes and its taxonomy is also very complicated. In tradition, the detection of Salmonella in environmental water samples by routines culture methods using selective media and characterization of suspicious colonies based on biochemical tests and serological assay are generally time and labor consuming. To overcome this disadvantage, it is desirable to use effective method which provides a higher discrimination and more rapid identification about Salmonella in environmental water. The aim of this study is to investigate the occurrence of Salmonella using novel procedures of detection method and to identify the serovars of Salmonella isolates from 157 surface water samples in Taiwan. The procedures include membrane filtration, non-selective pre-enrichment, selective enrichment of Salmonella, and then isolation of Salmonella strains by selective culture plates. The selective enrichment and culture plates were both detected by PCR. Finally, we used biochemical tests and serological assay to confirm the serovars of Salmonella and also used Pulsed-field gel electrophoresis (PFGE) to identify their sarovar catagories by the genetic pattern. In this study, 44 water samples (28%) were indentified as Salmonella. The 44 positive water samples by culture method were further identified as S. Agona(1/44), S. Albany (10/44), S. Bareilly (13/44),S. Choleraesuis (2/44),S. Derby (4/44),S. Isangi (3/44),S.Kedougou(3/44),S. Mbandaka(1/44),S.Newport (3/44), S. Oranienburg(1/44), S. Potsdam (1/44),S. Typhimurium (1/44), andS. Weltevreden(1/44) by PFGE. The presence of Salmonella in surface water indicates the possibility of waterborne transmission in drinking watershed if water is not adequately treated. Therefore, the authorities need to have operating systems that currently provide adequate source

Salmonella Inactivation During Extrusion of an Oat Flour Model Food.

PubMed

Anderson, Nathan M; Keller, Susanne E; Mishra, Niharika; Pickens, Shannon; Gradl, Dana; Hartter, Tim; Rokey, Galen; Dohl, Christopher; Plattner, Brian; Chirtel, Stuart; Grasso-Kelley, Elizabeth M

2017-03-01

Little research exists on Salmonella inactivation during extrusion processing, yet many outbreaks associated with low water activity foods since 2006 were linked to extruded foods. The aim of this research was to study Salmonella inactivation during extrusion of a model cereal product. Oat flour was inoculated with Salmonella enterica serovar Agona, an outbreak strain isolated from puffed cereals, and processed using a single-screw extruder at a feed rate of 75 kg/h and a screw speed of 500 rpm. Extrudate samples were collected from the barrel outlet in sterile bags and immediately cooled in an ice-water bath. Populations were determined using standard plate count methods or a modified most probable number when populations were low. Reductions in population were determined and analyzed using a general linear model. The regression model obtained for the response surface tested was Log (N R /N O ) = 20.50 + 0.82T - 141.16a w - 0.0039T 2 + 87.91a w 2 (R 2 = 0.69). The model showed significant (p < 0.05) linear and quadratic effects of a w and temperature and enabled an assessment of critical control parameters. Reductions of 0.67 ± 0.14 to 7.34 ± 0.02 log CFU/g were observed over ranges of a w (0.72 to 0.96) and temperature (65 to 100 °C) tested. Processing conditions above 82 °C and 0.89 a w achieved on average greater than a 5-log reduction of Salmonella. Results indicate that extrusion is an effective means for reducing Salmonella as most processes commonly employed to produce cereals and other low water activity foods exceed these parameters. Thus, contamination of an extruded food product would most likely occur postprocessing as a result of environmental contamination or through the addition of coatings and flavorings. © 2017 Institute of Food Technologists®.

Characterization of Nontyphoidal Salmonella Isolates from Asymptomatic Migrant Food Handlers in Peninsular Malaysia.

PubMed

Woh, Pei Yee; Thong, Kwai Lin; Behnke, Jerzy Marian; Lewis, John Watkin; Zain, Siti Nursheena Mohd

2017-08-01

Asymptomatic Salmonella carriers who work as food handlers pose food safety and public health risks, particularly during food preparation, and this has serious implications for the disease burden in society. Therefore, we conducted a study to determine the number of Salmonella carriers in a migrant cohort in several food establishments in three major cities in Peninsular Malaysia. Sociodemographic data and stool samples were collected and analyzed using standard methods of detection and isolation. Antimicrobial susceptibility tests of the positive samples were also performed. A total of 317 migrant food handlers, originating from South and Southeast Asian countries, were recruited voluntarily. Nine (2.8%) stool samples were confirmed to be Salmonella positive. PCR serotyping and pulsed-field gel electrophoresis identified four serotypes as Typhimurium (n = 3), Corvallis (n = 2), Hadar (n = 1), Agona (n = 1) and two unknown serovars. Antimicrobial susceptibility tests revealed that all nine isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, ceftazidime, ceftriaxone, and gentamycin. However, seven isolates were found to be multidrug resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, sulfonamides, streptomycin, and tetracycline. This study highlights that carriers of nontyphoidal Salmonella exist among migrant food handlers, which poses a health risk to consumers through food contamination. Our results indicate a need for authorities to enhance food safety awareness in the migrant workers and to reevaluate current health screening methods to include preventive measure such as mandatory stool screening as part of the preemployment and routine health examinations.

Development of a Loop Mediated Isothermal Amplification (LAMP) - Surface Enhanced Raman spectroscopy (SERS) Assay for the Detection of Salmonella Enterica Serotype Enteritidis.

PubMed

Draz, Mohamed Shehata; Lu, Xiaonan

2016-01-01

As a major foodborne pathogen, Salmonella enterica serotype Enteritidis is increasingly rising as a global health concern. Here, we developed an integrated assay that combines loop mediated isothermal amplification (LAMP) and surface enhanced Raman spectroscopy (SERS) for DNA detection of S. Enteritidis using specifically designed Raman active Au-nanoprobes. The target DNA was amplified by LAMP and then labeled with Au-nanoprobes comprised of gold nanoparticle-modified with specific cy5/DNA probes to allow the detection by SERS. The sensitivity of the developed LAMP-SERS detection assay (66 CFU/mL) was ~100-fold higher than the conventional polymerase chain reaction (PCR) method. Significantly, this technique allowed highly specific detection of the target DNA of S. Enteritidis and could differentiate it from the DNA of closely related bacterial species or non-specific contamination, making it more accurate and reliable than the standard LAMP technique. The applicability of detection of S. Enteritidis in milk samples using LAMP-SERS assay was validated as well. In sum, the developed LAMP-SERS assay is highly specific and sensitive, and has the potential to be applied for rapid detection of different foodborne pathogens and other microbial contaminants.

Survival rate of Salmonella and Shigella in fermented milk products with and without added human gastric juice: an in vitro study.

PubMed

Alm, L

1983-01-01

The survival rates of Salmonella agona, Salmonella java, Salmonella typhimurium and Shigella sonnei in milk and fermented milk products were investigated with and without the addition of human gastric juice during a 7 to 10 hour test period. It was found that yoghurt inhibited the growth of Salmonella and Shigella very effectively even when the yoghurt had been heated to 100 degrees C for 15 minutes, whereas milk and the other fermented milk products showed a lower ability to inhibit the growth of pathogens. Yoghurt plus human gastric juice greatly depressed the growth rate of the pathogens; after 30 minutes no more colonies were formed. Even kefir or ropy milk plus gastric juice showed inhibition of Salmonella typhimurium after one hour. In the case of acidophilus milk plus gastric juice, the inhibition of Salmonella typhimurium occurred first after 2.5 hours and the presence of viable Shigella sonnei was noticed for 4 hours. The addition of physiological NaCl instead of human gastric juice to the fermented milk samples before inoculation changed the picture of the survival rate. Only yoghurt inhibited the growth of Salmonella java after 30 minutes; Shigella sonnei survived in yoghurt for 4 hours and in the other fermented milk samples for 5 hours. It can be assumed that yoghurt contains some antimicrobial compounds that inhibit the growth of pathogens and that this inhibiting property is enhanced by the addition of human gastric juice.

Quantification, serovars, and antibiotic resistance of salmonella isolated from retail raw chicken meat in Vietnam.

PubMed

Ta, Yen T; Nguyen, Trung Thanh; To, Phuong Bich; Pham, Da Xuan; Le, Hao Thi Hong; Thi, Giang Nguyen; Alali, Walid Q; Walls, Isabel; Doyle, Michael P

2014-01-01

The objectives of this study were to quantify Salmonella counts on retail raw poultry meat in Vietnam and to phenotypically characterize (serovars and antibiotic resistance) the isolates. A total of 300 chicken carcasses were collected from two cities and two provinces in Vietnam. Salmonella counts on the samples were determined according to the most-probable-number (MPN) method of the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA-FSIS). A total of 457 isolates were serotyped and tested for antibiotic susceptibility. Overall, 48.7% of chicken samples were Salmonella positive with a count of 2.0 log MPN per carcass. There were no significant differences (P > 0.05) in log MPN per carcass by the study variables (market type, storage condition, and chicken production system). There was a significant difference (P < 0.05) in Salmonella-positive prevalence by chicken production system. Among the 22 Salmonella serovars identified, Albany was the most frequent (34.1%), followed by Agona (15.5%) and Dabou (8.8%). Resistance to at least one antibiotic was common (i.e., 73.3%), with high resistance to tetracycline (59.1%) and ampicillin (41.6%). Resistance to three antibiotics was the most frequently found multidrug resistance profile (17.7%, n = 81); the profile that was resistant to the highest number of drugs was resistant to nine antibiotics (0.7%, n = 3). Only Salmonella Albany posed phenotypic resistance to ceftriaxone (a drug of choice to treat severe cases of salmonellosis). The data revealed that, whereas Salmonella prevalence on raw poultry was high (48.7%), counts were low, which suggests that the exposure risk to Salmonella is low. However, improper storage of raw chicken meat and cross-contamination may increase Salmonella cell counts and pose a greater risk for infection. These data may be helpful in developing risk assessment models and preventing the transmission of foodborne Salmonella from poultry to humans in Vietnam.

Occurrence of antimicrobial-resistant salmonella species in raw and ready to eat turkey meat products from retail outlets in the midwestern United States.

PubMed

Khaitsa, Margaret L; Kegode, Redempta B; Doetkott, Dawn K

2007-01-01

To investigate occurrence of Salmonella in raw and ready to eat (RTE) turkey from retail outlets, determine factors associated with its occurrence and antimicrobial-resistance patterns. A total of 959 turkey products (raw, n = 345; and RTE, n = 614) were purchased in 3 months from four stores in one city in the midwestern United States. Chi-square and logistic regression analyses were used to test for associations of microbial contamination with product type and brand, expiration date, sampling time, and retail store. Antimicrobial resistance of Salmonellae was determined using a National Antimicrobial Resistance Monitoring System (NARMS) panel of antimicrobials. Overall, 2.2% (21/959) of the samples (4.1% [14/345] raw and 1.1% [7/614] RTE) were contaminated with Salmonella. A significant difference in Salmonella occurrence (p < 0.05), between meat type (raw vs. RTE; OR = 4.2, 95% CI = 1.6, 10.8); and sampling month (p < 0.05) was reported, but not between retail stores and product brands. Salmonellae belonged to 6 serotypes: Hadar, Heidelberg, Typhimurium var. Copenhagen, Newport, Saintpaul, and Agona. Salmonellae from raw turkey exhibited higher antimicrobial resistance (53%) compared to those from RTE products (33%). Multidrug resistance was exhibited by 62% of Salmonellae (86% RTE, 50% raw meats). CONCLUSION AND CLINICAL APPLICATIONS: Turkey (both raw and RTE) may occasionally be contaminated with antimicrobial-resistant Salmonellae whose occurrence was influenced by sampling month and meat type. Continued surveillance of Salmonella occurrence in meat products, in particular RTE ones, is warranted in order to ensure a safe food supply.

High prevalence of Salmonella in tegu lizards (Tupinambis merianae), and susceptibility of the serotypes to antibiotics.

PubMed

Maciel, B M; Argôlo Filho, R C; Nogueira, S S C; Dias, J C T; Rezende, R P

2010-12-01

Species of tegu (Tupinambis) are the largest lizards in South America. Large numbers of these lizards are hunted; there is a vigorous trade in their skins and the meat is consumed by rural and native peoples. The animals are also bred in captivity, an economic activity for rural populations which can help in the animals' conservation. Faecal samples from 30 captive-born tegus were analysed for the presence of Salmonella in two separate samplings. In the first analysis, samples from 26 animals (87%) yielded Salmonella enterica of which 23% were of Rubislaw serotype; 20% Carrau and Agona serotypes; 7% Infantis and Saint-Paul serotypes; 3% Panama and Brandenburg serotypes; 10% were S. enterica subsp. enterica and 7% were rough form. In the second analysis, four tegus (13%) which had been negative in the first sampling were positive, thus, 100% of the animals studied carried the bacterium. Antibiotic susceptibility showed resistance to sulfonamide in 82% of the isolates, streptomycin in 64%, tetracycline in 6% and Chloramphenicol in 20%. Two animals carried strains of the same serotype with different patterns of antibiotic susceptibility. Although it is well known that reptiles are a significant source of Salmonella, to our knowledge, its prevalence in tegu has not been studied previously.

Control of Salmonella on sprouting mung bean and alfalfa seeds by using a biocontrol preparation based on antagonistic bacteria and lytic bacteriophages.

PubMed

Ye, Jianxiong; Kostrzynska, Magdalaena; Dunfield, Kari; Warriner, Keith

2010-01-01

The following reports on the application of a combination of antagonistic bacteria and lytic bacteriophages to control the growth of Salmonella on sprouting mung beans and alfalfa seeds. Antagonistic bacteria were isolated from mung bean sprouts and tomatoes by using the deferred plate assay to assess anti-Salmonella activity. From the isolates screened, an Enterobacter asburiae strain (labeled "JX1") exhibited stable antagonistic activity against a broad range of Salmonella serovars (Agona, Berta, Enteritidis, Hadar, Heidelberg, Javiana, Montevideo, Muenchen, Newport, Saint Paul, and Typhimurium). Lytic bacteriophages against Salmonella were isolated from pig or cattle manure effluent. A bacteriophage cocktail prepared from six isolates was coinoculated with E. asburiae JX1 along with Salmonella in broth culture. The combination of E. asburiae JX1 and bacteriophage cocktail reduced the levels of Salmonella by 5.7 to 6.4 log CFU/ml. Mung beans inoculated with Salmonella and sprouted over a 4-day period attained levels of 6.72 + or - 0.78 log CFU/g. In contrast, levels of Salmonella were reduced to 3.31 + or - 2.48 or 1.16 + or - 2.14 log CFU/g when the pathogen was coinoculated with bacteriophages or E. asburiae JX1, respectively. However, by using a combination of E. asburiae JX1 and bacteriophages, the levels of Salmonella associated with mung bean sprouts were only detected by enrichment. The biocontrol preparation was effective at controlling the growth of Salmonella under a range of sprouting temperatures (20 to 30 degrees Celsius) and was equally effective at suppressing the growth of Salmonella on sprouting alfalfa seeds. The combination of E. asburiae JX1 and bacteriophages represents a promising, chemical-free approach for controlling the growth of Salmonella on sprouting seeds.

Overview of the development of quinolone resistance in Salmonella species in China, 2005–2016

PubMed Central

Song, Qifa; Xu, Zhaojun; Gao, Hong; Zhang, Danyang

2018-01-01

Purpose Several factors contribute to the complexity of quinolone resistance in Salmonella, including >2000 different Salmonella serotypes, a variety of hosts for Salmonella, and wide use of quinolones in human beings and animals. We thus aimed to obtain an overview of the development of quinolone resistance and relevant molecular mechanisms of such a resistance in Salmonella species. Materials and methods A total of 1,776 Salmonella isolates were collected in Ningbo, China, between 2005 and 2016. Antimicrobial susceptibility to quinolone and relevant genetic mechanisms in these isolates were retrospectively analyzed. Results The ratio for ciprofloxacin (CIP) resistant:reduced CIP susceptible:CIP susceptible was 26:522:1,228. CIP resistance was found in nine of 51 serotypes: Derby, London, Kentucky, Indiana, Corvallis, Rissen, Hadar, Typhimurium, and Agona. Of 26 CIP-resistant isolates, all were concurrently resistant to ampicillin and 21 were also concurrently resistant to cefotaxime and produced extended-spectrum β-lactamase (ESBL). The minimal inhibitory concentration values were at three levels: 2–4 μg/mL (serotypes except for Kentucky and Indiana), 16 μg/mL (one Kentucky isolate), and >32 μg/mL (Indiana isolates). As with the three most common serotypes, Salmonella Typhi showed quickly increased prevalence of reduced CIP susceptibility in recent years, Salmonella Enteritidis remained at a high prevalence of reduced CIP susceptibility throughout the study period, and several isolates of Salmonella Typhimurium were resistant to CIP. Transferable plasmid-mediated quinolone resistance gene qnrB was only found in all CIP-resistant isolates. In contrast, gyrA mutations were often found in reduced CIP-susceptible isolates and were not necessarily found in all CIP-resistant isolates. Conclusion We conclude that in Salmonella, there exists a high prevalence of reduced CIP susceptibility and a low prevalence of CIP resistance, which focuses on several serotypes

Effectiveness of calcium hypochlorite on viral and bacterial contamination of alfalfa seeds.

PubMed

Wang, Qing; Kniel, Kalmia E

2014-10-01

Alfalfa sprouts have been involved in numerous foodborne outbreaks, which has increased the awareness for seed and sprout safety. This study compared the effectiveness of calcium hypochlorite (Ca(OCl)2) on the inactivation of bacteria and viruses on alfalfa seeds and in the presence of a simulated organic load. Alfalfa seeds were inoculated with human norovirus (huNoV) genogroup II (GII), murine norovirus (MNV), Tulane virus (TV), Escherichia coli O104:H4, and Salmonella enterica serovar Agona. Seeds were treated with Ca(OCl)2 (2000 ppm or 20,000 ppm with the average of free chlorine 1388 ± 117 mg/L and 11,472 ± 1500 mg/L, respectively, pH adjusted to 7.00). The reduction of huNoV genomic copies indicated that huNoV was relatively resistant to Ca(OCl)2 regardless of concentrations. Significant reductions were observed in the order of TV < Salmonella Agona < MNV < E. coli O104:H4 at 20,000 ppm Ca(OCl)2. A similar trend was found at 2000 ppm Ca(OCl)2 in the order of TV, Salmonella Agona, MNV < E. coli O104:H4. Ca(OCl)2 at 20,000 ppm was more effective than 2000 ppm for all the organisms tested. This trend was also observed in samples containing an artificial organic material load. Ca(OCl)2 activity on virus inactivation decreased as the organic load increased. Reduction was greater in fetal bovine serum-containing samples compared to alfalfa seeds, indicating a close relationship between the organisms and alfalfa seeds. Ca(OCl)2 could not completely inactivate bacteria or viruses inoculated on seeds, and high levels of E. coli O104:H4 and Salmonella Agona were present on sprouts from sanitized seed samples following a 7-day germination period.

Case study of the use of pulsed field gel electrophoresis in the detection of a food-borne outbreak.

PubMed

De Lappe, Niall; Cormican, Martin

2015-01-01

In early July 2008, a cluster of six Salmonella Agona was identified in the Republic of Ireland. A dispersed, common source outbreak was suspected. Later in July a further case was identified and the Health Protection Agency in the UK indicated that they had 32 cases of S. Agona since Feb 2008. This chapter discusses how pulsed field gel electrophoresis was used to help confirm an outbreak and to trace the source of the outbreak.

Serotypes and Antimicrobial Resistance in Salmonella enterica Recovered from Clinical Samples from Cattle and Swine in Minnesota, 2006 to 2015.

PubMed

Hong, Samuel; Rovira, Albert; Davies, Peter; Ahlstrom, Christina; Muellner, Petra; Rendahl, Aaron; Olsen, Karen; Bender, Jeff B; Wells, Scott; Perez, Andres; Alvarez, Julio

2016-01-01

Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance.

Incidence of salmonella infection in animals in England and Wales 1968--1974.

PubMed Central

Sojka, W. J.; Wray, C.; Shreeve, J.; Benson, A. J.

1977-01-01

Of a total of 23,609 incidents of salmonella infection reported during the period 1968--74, 20,326 occurred in cattle, 1744 in poultry and other birds, 675 in sheep, 558 in pigs and 306 in other species of animals. Despite the large number of serotypes isolated (153), 88% of incidents were due to only two stereotypes: S. dublin (15,929 incidents of which 15,446 occurred in cattle ) and S. typhimurium (4842 incidents of which 3785 occurred in cattle and 732 in birds). S. choleraesuis was the third (314 incidents which with only 5 exceptions occurred in pigs) and S. abortusovis (243 incidents all in sheep) was the fourth most commonly isolated serotype. The following six serotypes were each recorded in more than 100 incidents: S. newport (177), S. agona (170), S. virchow (169), S. anatum (152), S. enteritidis (150) and S. montevideo (111). The other 143 serotypes accounted for only 5-8% of total incidents. The trends of annual incidence of salmonella infection in cattle, sheep, pigs, poultry and other birds during the 17-year period 1958-74 and the distribution of the main serotypes in the individual species of animals from 1968 to 1974 are discussed. PMID:319168

Deoxyribonucleic acid restriction and modification systems in Salmonella: chromosomally located systems of different serotypes.

PubMed Central

Bullas, L R; Colson, C; Neufeld, B

1980-01-01

With the use of four different phages, Salmonella strains representing 85 different serotypes were examined to determine their restriction-modification phenotype. They fell into one of three groups on this basis: group 1, those which lacked the common LT system; group 2, those in which only the LT system could be recognized; and group 3. those which possessed the LT system and at least one other system shown with some serotypes to be closely linked to serB. The specificity of the serB-linked restriction-modification system was unique for each serotype, but different strains of the same serotype expressed the same specificity. Two of the systems were shown to behave in genetic crosses as functional alleles of the S. typhimurium SB system. It is possible that these serB-linked restriction-modification systems constitute a large multiallelic series of genes extending throughout the Salmonella genus and Escherichia coli. We suggest that the division of the Salmonella into the three restriction-modification groups may be significant in defining a "biological grouping" of the different serotypes within the genus which may ultimately be useful in describing the Salmonella species. From the genetic relatedness between the genes of some of the Salmonella restriction-modification systems with those of the E. coli systems, we deduce that the restriction endonuclases produced by the Salmonella serB-linked systems are of type 1. Determination of the nucleotide sequences of the recognition sites of the restriction endonucleases of selected Salmonella systems should further our understanding of specificity with these enzymes. PMID:6243623

Global monitoring of Salmonella serovar distribution from the World Health Organization Global Foodborne Infections Network Country Data Bank: results of quality assured laboratories from 2001 to 2007.

PubMed

Hendriksen, Rene S; Vieira, Antonio R; Karlsmose, Susanne; Lo Fo Wong, Danilo M A; Jensen, Arne B; Wegener, Henrik C; Aarestrup, Frank M

2011-08-01

Salmonella enterica is commonly acquired from contaminated food and is an important cause of illness worldwide. Interventions are needed to control Salmonella; subtyping Salmonella by serotyping is useful for targeting such interventions. We, therefore, analyzed the global distribution of the 15 most frequently identified serovars of Salmonella isolated from humans from 2001 to 2007 in laboratories from 37 countries that participated in World Health Organization Global Foodborne Infections Network and demonstrated serotyping proficiency in the Global Foodborne Infections Network External Quality Assurance System. In all regions throughout the study period, with the exception of the Oceania and North American regions, Salmonella serovars Enteritidis and Typhimurium ranked as the most common and second most common serovar, respectively. In the North American and Oceania (Australia and New Zealand) regions, Salmonella serovar Typhimurium was the most common serovar reported, and Salmonella serovar Enteritidis was the second most common serovar. During the study period, the proportion of Salmonella isolates reported from humans that were Salmonella serovar Enteritidis was 43.5% (range: 40.6% [2007] to 44.9% [2003]), and Salmonella serovar Typhimurium was 17.1% (range: 15% [2007] to 18.9% [2001]). Salmonella serovars Newport (mainly observed in Latin and North American and European countries), Infantis (dominating in all regions), Virchow (mainly observed in Asian, European, and Oceanic countries), Hadar (profound in European countries), and Agona (intense in Latin and North American and European countries) were also frequently isolated with an overall proportion of 3.5%, 1.8%, 1.5%, 1.5%, and 0.8%, respectively. There were large differences in the most commonly isolated serovars between regions, but lesser differences between countries within the same region. The results also highlight the complexity of the global epidemiology of Salmonella and the need and importance

SEROVARS AND ANTIMICROBIAL RESISTANCE OF Salmonella spp. ISOLATED FROM TURKEY AND BROILER CARCASSES IN SOUTHERN BRAZIL BETWEEN 2004 AND 2006

PubMed Central

PALMEIRA, Andre; dos SANTOS, Luciana Ruschel; BORSOI, Anderlise; RODRIGUES, Laura Beatriz; CALASANS, Max; do NASCIMENTO, Vladimir Pinheiro

2016-01-01

Salmonella spp. causes diseases in fowls, when species-specific serovars (Salmonella Pullorum and S.Gallinarum) are present in flocks, and public health problems, when non-typhoid serovars are isolated, as well as possible bacterial resistance induced by the preventive and therapeutic use of antimicrobials in animal production. This study describes the serovars and bacterial resistance of 280Salmonella spp. strains isolated from turkey and broiler carcasses in Southern Brazil between 2004 and 2006. SalmonellaEnteritidis was the most prevalent serovar (55.7%), followed by Heidelberg (5.0%), Agona (4.3%), Bredeney (3.9%), Hadar (3.2%), and Typhimurium (2.9%). Tennessee and S. Enterica subspecies enterica(O: 4.5) were isolated only in turkeys, and Hadar (18.6%) was the most prevalent serovar in this species. Antimicrobial susceptibility tests were performed in 178 isolates (43 from turkeys and 135 from broilers). All isolates were sensitive to amoxicillin + clavulanic acid, polymyxin B, ciprofloxacin, and norfloxacin, and were resistant to bacitracin and penicillin. Broiler carcass isolates showed resistance to nalidixic acid (48.9%), nitrofurantoin (34.3%), neomycin (9.6%), tetracycline (5.2%), and kanamycin (8.9%); and turkey carcass isolates were resistant to nalidixic acid (62.8%), tetracycline (34.9%), and neomycin (30.2%), with a significant difference in turkeys when compared to broiler carcass isolates. These results indicate the need for judicious use of antimicrobials in livestock production, given that the serovars identified are potential causes of food poisoning. PMID:27007562

[Fluoroquinolone resistance mutations in topoisomerase genes of Salmonella typhimurium isolates].

PubMed

Guo, Yunchang; Pei, Xiaoyan; Liu, Xiumei

2004-09-01

Mutations in topoisomerase genes were main cause of the resistence of Salmonella typhimurium to fluoroquinolone. The MICs of three Salmonella typhimurium isolates X2, X7, X11 to ciprofloxacin were above 32 microg/ml, 0.38 microg/ml and 0.023 microg/ml, respectively. The genetic alterations in four topoisomerase genes, gyrA, gyrB, parC, and parE were detected by multiplex PCR amplimer conformation analysis in these three strains. X2 isolate showed both gyrA mutations (Ser83-->Phe, Asp87-->Asn) and parC mutation (Ser80-->Arg). X7 isolate showed a single gyrA mutation (Ser83-->Phe) and X11 isolate had no changes in all of the four quinolone resistance genes, gyrA, gyrB, parC, and parE. X7 isolate with a single gyrA mutation was less resistant to ciprofloxacin than X2 with double gyrA mutations and an additional parC mutation. GyrA and parC genes play important role of the resistance of Salmonella typhimurium to ciprofloxacin.

Salmonella typhimurium gyrA mutations associated with fluoroquinolone resistance.

PubMed Central

Reyna, F; Huesca, M; González, V; Fuchs, L Y

1995-01-01

Spontaneous quinolone-resistant mutants obtained from Salmonella typhimurium Su694 were screened for mutations by direct DNA sequencing of an amplified PCR gyrA fragment. Substitutions Ser-83-->Phe (Ser83Phe), Ser83Tyr, Asp87Tyr, and Asp87Asn and double mutation Ala67Pro-Gly81Ser, which resulted in decreased sensitivities to ciprofloxacin, enoxacin, pefloxacin, norfloxacin, ofloxacin, and nalidixic acid, were found. The levels of resistance to quinolones for each mutant were determined. PMID:7492118

Gold nanoparticles enhanced SERS aptasensor for the simultaneous detection of Salmonella typhimurium and Staphylococcus aureus.

PubMed

Zhang, Hui; Ma, Xiaoyuan; Liu, Ying; Duan, Nuo; Wu, Shijia; Wang, Zhouping; Xu, Baocai

2015-12-15

Salmonella typhimurium and Staphylococcus aureus are most common causes of food-associated disease. A Raman based biosensor was developed for S. typhimurium and S. aureus detection simultaneously. The biosensor was based on nanoparticles enhanced Raman intensity and the specific recognition of aptamer. The Raman signal probe and the capture probe are built. Gold nanoparticles (GNPs) modified with Raman molecules (Mercaptobenzoic acid and 5,5'-Dithiobis(2-nitrobenzoic acid)) and aptamer are used as the signal probe for S. typhimurium and S. aureus, respectively. Fe3O4 magnetic gold nanoparticles (MGNPs) immobilized with both aptamer of S. typhimurium and S. aureus are used as the capture probe. When S. typhimurium and S. aureus are added in the reaction system, the capture probe will capture the target bacteria through the specific binding effect of aptamer. And then the signal probe will be connected to the bacteria also by the effect of aptamer to form the sandwich like detection structure. The Raman intensified spectrum was measured to quantify S. typhimurium and S. aureus. Under optimal conditions, the SERS intensity of MBA at 1582 cm(-1) are used to measure S. typhimurium (y=186.4762+704.8571x, R(2)=0.9921) and the SERS intensity of DNTB at 1333 cm(-1) are used to measure S. aureus (y=135.2381+211.4286x, R(2)=0.9946) in the range of 10(2)-10(7) cfu mL(-1). The LOD is 35 cfu mL(-1) for S. aureus and 15 cfu mL(-1) for S. typhimurium. This method is simple and rapid, results in high sensitivity and specificity, and can be used to detect actual samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Prevalence of extended-spectrum b-lactamase-producing Salmonella on retail chicken in six provinces and two national cities in the People's Republic of China.

PubMed

Wu, Haiyun; Xia, Xiaodong; Cui, Yue; Hu, Yuanyuan; Xi, Meili; Wang, Xin; Shi, Xianming; Wang, Dapeng; Meng, Jianghong; Yang, Baowei

2013-12-01

Prevalence of extended-spectrum β-lactamase (ESBL)-producing Salmonella in food is not well documented. This study investigated the prevalence of ESBL-producing Salmonella in 699 Salmonella isolates recovered from 1,152 retail chickens collected from six provinces and two national cities in the People's Republic of China in 2011. ESBL-producing isolates were screened by double-disk synergy test and confirmed using PCR and DNA sequencing. Of the 699 isolates tested, 60 (8.58%) were identified to be ESBL-producing Salmonella. Prevalence of ESBL-producing Salmonella was the highest in Shanghai city (17 [24.64%] of 69), followed by Shaanxi (10 [15.38%] of 65), Fujian (9 [11.69%] of 77), Guangdong (9 [7.69%] of 117), Sichuan (5 [7.25%] of 69), Beijing (6 [5.17%] of 116), Henan (4 [4.65%] of 86), and Guangxi (0 [0%] of 100) province. Significant difference (P < 0.05) in the prevalence of ESBL-producing Salmonella was found among six provinces and two cities. No significant difference (P > 0.05) in the prevalence was found between wet markets and supermarkets or between whole chickens and chopped chickens. The prevalence of ESBL-producing Salmonella differed significantly (P < 0.05) among different seasons, being higher in autumn than in spring and winter. Overall, ESBL-producing Salmonella varied significantly (P < 0.05) among 12 detected Salmonella serotypes: Abony (1 [33.33%] of 3), Indiana (28 [28.57%] of 98), Edinburg (6 [24.00%] of 25), Shubra (2 [20.00%] of 10), Uppsala (1 [16.67%] of 6), Thompson (8 [14.81%] of 54), Haardt (1 [12.50%] of 8), Agona (3 [9.68%] of 31), Gueuletapee (1 [6.25%] of 16), Typhimurium (4 [5.56%] of 72), Heidelberg (1 [4.55%] of 22), and Enteritidis (4 [3.17%] of 126). This study revealed that ESBL-producing Salmonella do exist in retail chicken in the People's Republic of China and that the potential risk of their presence in foods needs further exploration.

Characterization of bla(CMY)-encoding plasmids among Salmonella isolated in the United States in 2007.

PubMed

Folster, Jason P; Pecic, Gary; McCullough, Andre; Rickert, Regan; Whichard, Jean M

2011-12-01

Salmonella enterica is one of the most common bacterial causes of foodborne illness, and nontyphoidal Salmonella is estimated to cause ∼1.2 million illnesses in the United States each year. Plasmids are mobile genetic elements that play a critical role in the dissemination of antimicrobial resistance determinants. AmpC-type CMY β-lactamases (bla(CMY)) confer resistance to extended-spectrum cephalosporins and β-lactam/β-lactamase inhibitor combinations and are commonly plasmid-encoded. A variety of plasmids have been shown to encode CMY β-lactamases and certain plasmids may be associated with particular Salmonella serotypes or environmental sources. In this study, we characterized bla(CMY) β-lactamase-encoding plasmids among Salmonella isolates. Isolates of Salmonella from specimens collected from humans in 2007 were submitted to the Centers for Disease Control and Prevention National Antimicrobial Resistance Monitoring System laboratory for susceptibility testing. Three percent (65/2161) of Salmonella isolates displayed resistance to ceftriaxone (minimum inhibitory concentration [MIC] ≥4 mg/L) and amoxicillin/clavulanic acid (MIC ≥32 mg/L), a combination associated with the presence of a bla(CMY) mechanism of resistance. Sixty-four (98.5%) isolates were polymerase chain reaction-positive for bla(CMY) genes. Transformation and conjugation studies showed that 95% (61/64) of the bla(CMY) genes were plasmid-encoded. Most of the bla(CMY)-positive isolates were serotype Typhimurium, Newport, Heidelberg, and Agona. Forty-three plasmids were replicon type IncA/C, 15 IncI1, 2 contained multiple replicon loci, and 1 was untypeable. IncI1 plasmids conferred only the bla(CMY)-associated resistance phenotype, whereas IncA/C plasmids conferred additional multi-drug resistance (MDR) phenotypes to drugs such as chloramphenicol, sulfisoxazole, and tetracycline. Most of the IncI1 plasmids (12/15) were sequence type 12 by plasmid multi-locus sequence typing. CMY �

Assessment of the effect of a Salmonella enterica ser. Typhimurium culture supernatant on the single-cell lag time of foodborne pathogens.

PubMed

Blana, Vasiliki A; Lianou, Alexandra; Nychas, George-John E

2015-12-23

The objective of this study was the in vitro evaluation of the effect of a cell-free microbial supernatant, produced by a luxS-positive Salmonella enterica ser. Typhimurium strain, on the single-cell growth kinetic behavior of two strains of S. enterica (serotypes Enteritidis and Typhimurium) and a methicillin-resistant Staphylococcus aureus strain. The single-cell lag time (λ) of the pathogens was estimated in the absence and presence (20% v/v) of microbial supernatant based on optical density measurements. As demonstrated by the obtained results, the tested microbial supernatant had a strain-specific effect on the single-cell λ and its variability. Although the mean λ values were similar in the absence and presence of microbial supernatant in the case of Salmonella Enteritidis, a significant (P ≤ 0.05) reduction and increase in the mean value of this parameter in the presence of microbial supernatant were observed for Salmonella Typhimurium and St. aureus, respectively. With regard to the effect of the tested microbial supernatant on the single-cell variability of λ, similar λ distributions were obtained in its absence and presence for S. Enteritidis, while considerable differences were noted for the other two tested organisms; the coefficient of variation of λ in the absence and presence of microbial supernatant was 41.6 and 69.8% for S. Typhimurium, respectively, with the corresponding values for St. aureus being 74.0 and 56.9%. As demonstrated by the results of bioassays, the tested microbial supernatant exhibited autoinducer-2 activity, indicating a potential association of such quorum sensing compounds with the observed effects. Although preliminary in nature, the collected data provide a good basis for future research on the role of quorum sensing in the single-cell growth behavior of foodborne pathogens.

Immune protection of chickens conferred by a vaccine consisting of attenuated strains of Salmonella Enteritidis, Typhimurium and Infantis.

PubMed

Varmuzova, Karolina; Faldynova, Marcela; Elsheimer-Matulova, Marta; Sebkova, Alena; Polansky, Ondrej; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

2016-10-15

The colonization of poultry with different Salmonella enterica serovars poses an issue throughout the world. In this study we therefore tested the efficacy of a vaccine consisting of attenuated strains of Salmonella enterica serovars Enteritidis, Typhimurium and Infantis against challenge with the same serovars and with S. Agona, Dublin and Hadar. We tested oral and aerosol administration of the vaccine, with or without co-administration of cecal microbiota from adult hens. The protective effect was determined by bacterial counts of the challenge strains up to week 18 of life and by characterizing the immune response using real-time PCR specific for 16 different genes. We have shown that a vaccine consisting of attenuated S. Enteritidis, S. Typhimurium and S. Infantis protected chickens against challenge with the wild type strains of the same serovars and partially protected chickens also against challenge with isolates belonging to serovars Dublin or Hadar. Aerosol vaccination was more effective at inducing systemic immunity whilst oral vaccination stimulated a local immune response in the gut. Co-administration of cecal microbiota increased the protectiveness in the intestinal tract but slightly decreased the systemic immune response. Adjusting the vaccine composition and changing the administration route therefore affects vaccine efficacy.

Persistence of two Salmonella enterica ser. Montevideo strains throughout horn fly (Diptera: Muscidae) larval and pupal development

USDA-ARS?s Scientific Manuscript database

Strains of Salmonella enterica can be subdivided into clades that differ in their composition of genes, including those that influence microbial ecology and bacterial transmission. Salmonella serovar Montevideo strains 1110 and 304, representatives of two different clades, were used throughout this ...

Human Salmonella and Concurrent Decreased Susceptibility to Quinolones and Extended-Spectrum Cephalosporins

PubMed Central

Gay, Kathryn; Stevenson, Jennifer E.; Joyce, Kevin J.; Cooper, Kara L.; Omondi, Michael; Medalla, Felicita; Jacoby, George A.; Barrett, Timothy J.

2007-01-01

The National Antimicrobial Resistance Monitoring System monitors susceptibility among Enterobacteriaceae in humans in the United States. We studied isolates exhibiting decreased susceptibility to quinolones (nalidixic acid MIC >32 µg/mL or ciprofloxacin MIC >0.12 µg/mL) and extended-spectrum cephalosporins (ceftiofur or ceftriaxone MIC >2 µg/mL) during 1996–2004. Of non-Typhi Salmonella, 0.19% (27/14,043) met these criteria: 11 Senftenberg; 6 Typhimurium; 3 Newport; 2 Enteridis; and 1 each Agona, Haifa, Mbandaka, Saintpaul, and Uganda. Twenty-six isolates had gyrA mutations (11 at codon 83 only, 3 at codon 87 only, 12 at both). All Senftenberg isolates had parC mutations (S80I and T57S); 6 others had the T57S mutation. The Mbandaka isolate contained qnrB2. Eight isolates contained blaCMY-2; 1 Senftenberg contained blaCMY-23. One Senftenberg and 1Typhimurium isolate contained blaSHV-12; the Mbandaka isolate contained blaSHV-30. Nine Senftenberg isolates contained blaOXA-1; 1 contained blaOXA-9. Further studies should address patient outcomes, risk factors, and resistance dissemination prevention strategies. PMID:18217551

Human Salmonella and concurrent decreased susceptibility to quinolones and extended-spectrum cephalosporins.

PubMed

Whichard, Jean M; Gay, Kathryn; Stevenson, Jennifer E; Joyce, Kevin J; Cooper, Kara L; Omondi, Michael; Medalla, Felicita; Jacoby, George A; Barrett, Timothy J

2007-11-01

The National Antimicrobial Resistance Monitoring System monitors susceptibility among Enterobacteriaceae in humans in the United States. We studied isolates exhibiting decreased susceptibility to quinolones (nalidixic acid MIC >32 microg/mL or ciprofloxacin MIC > or =0.12 microg/mL) and extended-spectrum cephalosporins (ceftiofur or ceftriaxone MIC > or =2 microg/mL) during 1996-2004. Of non-Typhi Salmonella, 0.19% (27/14,043) met these criteria: 11 Senftenberg; 6 Typhimurium; 3 Newport; 2 Enteridis; and 1 each Agona, Haifa, Mbandaka, Saintpaul, and Uganda. Twenty-six isolates had gyrA mutations (11 at codon 83 only, 3 at codon 87 only, 12 at both). All Senftenberg isolates had parC mutations (S801 and T57S); 6 others had the T57S mutation. The Mbandaka isolate contained qnrB2. Eight isolates contained bla(CMY-2); 1 Senftenberg contained bla(CMY-23). One Senftenberg and 1 Typhimurium isolate contained bla(SHV-12); the Mbandaka isolate contained bla(SHV-30). Nine Senftenberg isolates contained bla(OXA-1) contained bla(OXA-9). Further studies should address patient outcomes, risk factors, and resistance dissemination prevention strategies.

A Multicountry Molecular Analysis of Salmonella enterica Serovar Typhi With Reduced Susceptibility to Ciprofloxacin in Sub-Saharan Africa

PubMed Central

Al-Emran, Hassan M.; Eibach, Daniel; Krumkamp, Ralf; Ali, Mohammad; Baker, Stephen; Biggs, Holly M.; Bjerregaard-Andersen, Morten; Breiman, Robert F.; Clemens, John D.; Crump, John A.; Cruz Espinoza, Ligia Maria; Deerin, Jessica; Dekker, Denise Myriam; Gassama Sow, Amy; Hertz, Julian T.; Im, Justin; Ibrango, Samuel; von Kalckreuth, Vera; Kabore, Leon Parfait; Konings, Frank; Løfberg, Sandra Valborg; Meyer, Christian G.; Mintz, Eric D.; Montgomery, Joel M.; Olack, Beatrice; Pak, Gi Deok; Panzner, Ursula; Park, Se Eun; Razafindrabe, Jean Luco Tsiriniaina; Rabezanahary, Henintsoa; Rakotondrainiarivelo, Jean Philibert; Rakotozandrindrainy, Raphaël; Raminosoa, Tiana Mirana; Schütt-Gerowitt, Heidi; Sampo, Emmanuel; Soura, Abdramane Bassiahi; Tall, Adama; Warren, Michelle; Wierzba, Thomas F.; May, Jürgen; Marks, Florian

2016-01-01

Background. Salmonella enterica serovar Typhi is a predominant cause of bloodstream infections in sub-Saharan Africa (SSA). Increasing numbers of S. Typhi with resistance to ciprofloxacin have been reported from different parts of the world. However, data from SSA are limited. In this study, we aimed to measure the ciprofloxacin susceptibility of S. Typhi isolated from patients with febrile illness in SSA. Methods. Febrile patients from 9 sites within 6 countries in SSA with a body temperature of ≥38.0°C were enrolled in this study. Blood samples were obtained for bacterial culture, and Salmonella isolates were identified biochemically and confirmed by multiplex polymerase chain reaction (PCR). Antimicrobial susceptibility of all Salmonella isolates was performed by disk diffusion test, and minimum inhibitory concentrations (MICs) against ciprofloxacin were measured by Etest. All Salmonella isolates with reduced susceptibility to ciprofloxacin (MIC > 0.06 µg/mL) were screened for mutations in quinolone resistance-determining regions in target genes, and the presence of plasmid-mediated quinolone resistance (PMQR) genes was assessed by PCR. Results. A total of 8161 blood cultures were performed, and 100 (1.2%) S. Typhi, 2 (<0.1%) Salmonella enterica serovar Paratyphi A, and 27 (0.3%) nontyphoid Salmonella (NTS) were isolated. Multidrug-resistant S. Typhi were isolated in Kenya (79% [n = 38]) and Tanzania (89% [n = 8]) only. Reduced ciprofloxacin-susceptible (22% [n = 11]) S. Typhi were isolated only in Kenya. Among those 11 isolates, all had a Glu133Gly mutation in the gyrA gene combined with either a gyrA (Ser83Phe) or gyrB mutation (Ser464Phe). One Salmonella Paratyphi A isolate with reduced susceptibility to ciprofloxacin was found in Senegal, with 1 mutation in gyrA (Ser83Phe) and a second mutation in parC (Ser57Phe). Mutations in the parE gene and PMQR genes were not detected in any isolate. Conclusions. Salmonella Typhi with reduced susceptibility

Impact of relative humidity, inoculum carrier and size, and native microbiota on Salmonella ser. Typhimurium survival in baby lettuce.

PubMed

López-Gálvez, Francisco; Gil, Maria Isabel; Allende, Ana

2018-04-01

The effects of relative humidity (RH), fluctuating climate conditions, inoculum size and carrier on the survival of Salmonella enterica serovar Typhimurium on baby lettuce in environmental test chambers were studied. Buffered peptone water (BPW), distilled water (DW), and irrigation water (IW) were compared as inoculum carriers. Additionally, survival of Salmonella in suspensions prepared using filtered and unfiltered IW was assessed. Salmonella Typhimurium survived better on baby lettuce plants at high RH independently of the inoculum size. When lettuce plants were grown under fluctuating environmental conditions, Salmonella survival was similar under both RH conditions. Regarding the inoculum carrier, the inoculated microorganism survived better on lettuce plants when BPW was used as carrier both at high and low RH. Survival rate of Salmonella in IW was affected by the presence of native microbiota. Native microbiota present in IW did not affect survival of Salmonella or the levels of mesophilic bacteria on the baby lettuce leaves. The information obtained in the present study contributes to the knowledge on the effect of environmental conditions on pathogenic bacteria survival on growing edible plants. These results are useful when selecting the methodology to carry out experimental studies on the survival of microbial pathogens under different pre-harvest conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Salmonella isolated from chicken carcasses from a slaughterhouse in the state of Mato Grosso, Brazil: antibiotic resistance profile, serotyping, and characterization by repetitive sequence-based PCR system.

PubMed

Cunha-Neto, Adelino da; Carvalho, Larrayane Albuês; Carvalho, Ricardo César Tavares; Dos Prazeres Rodrigues, Dália; Mano, Sergio Borges; Figueiredo, Eduardo Eustáquio de Souza; Conte-Junior, Carlos Adam

2018-04-01

Salmonella is one of the major causative agents of foodborne infections. Salmonellosis becomes more dangerous when strains resistant to several antibiotics are found in food, especially in chicken, one of the primary transmission vehicles of this pathogen for humans. The present study aimed to estimate the occurrence of Salmonella in chicken carcasses from the state of Mato Grosso, Brazil, as well as determine the antibiotic resistance profile and genotypic characteristic of multi-drug resistant (MDR) isolates. During a 15-month period, from 01/2014 to 05/2015, 850 samples of chilled fresh chicken carcasses were sampled from a slaughterhouse and submitted to Salmonella determinations according to the ISO-6579/2002 method, serotyping and multiplex PCR. The disc diffusion test was applied for 17 antibiotics, according to CLSI (2014). Five isolates were genotyped by repetitive sequence-based PCR using the semi-automated DiversiLab (bioMérieux®) system. The occurrence of Salmonella in chicken carcasses was of 3.7% (31/850), with only 4 strains (12.9%) presenting as MDR, and 6 strains (19.35%) displaying ESBL. The predominant serovars were Salmonella Infantis (35.4%, 11/31), and S. Abony (25.8%, 8/31), followed by serovars S. Agona (12.9%, 4/31), S. Schwarzengrund (9.7%, 3/31), S. Anatum and Salmonella enterica O:4,5 (6.5%, 2/31), and only one Salmonella enterica O:6,7 strain (3.2%, 1/31). All isolates were resistant to one to 5 classes of antibiotics in decreasing order: folate pathway inhibitors, β-lactams (cephalosporins, penicillin, monobactams), tetracyclines, chloramphenicol, and gentamicin. However, strains sensitive to florfenicol, streptomycin, nalidixic acid, ciprofloxacin, enrofloxacin, and nitrofurantoin were also found in this study. Genotyping revealed 98 to 99% homology between 3 Salmonella strains, which displayed high phenotypic resistance similarity to β-lactams and folate pathway inhibitors. Detection of MDR non-typhoid Salmonella in chicken

Cantaloupe facilitates transmission of Salmonella typhimurium between adult house flies

USDA-ARS?s Scientific Manuscript database

Salmonella enterica ser. Typhimurium (S. Typhimurium) is a pathogen harbored by livestock that can contaminate fresh produce, such as cantaloupe, and cause food-borne illnesses. We previously demonstrated that house flies acquire and harbor S. Typhimurium after exposure to inoculated cattle manure. ...

Identification of the crucial genes in the elimination and survival process of Salmonella enterica ser. Pullorum in the chicken spleen.

PubMed

Ma, T; Xu, L; Wang, H; Guo, X; Li, Z; Wan, F; Chen, J; Liu, L; Liu, X; Chang, G; Chen, G

2017-06-01

Salmonella enterica ser. Pullorum is one of the most easily re-infecting pathogens in poultry production because of its mechanism of escaping from immune elimination. We used the transcriptome method to investigate the variation in gene expression in chicken spleen resulting from the interaction between hosts and S. Pullorum in the survival process. The expression of various genes related to the maturation and activation of B cells was activated before S. Pullorum was eliminated, which might help S. Pullorum escape from the elimination process. The suppression of some genes involved in the fusion of autophagosomes and lysosomes, such as MYO6, was identified and may be regulated by the secretion systems of S. Pullorum. In addition, a large proportion of these differentially expressed genes could be localized in the identified quantitative trait loci regions associated with the antibody response to bacteria. Collectively, these identified genes provided an outline for further understanding the interaction between chicken immune cells and S. Pullorum in chicken spleen. © 2017 Stichting International Foundation for Animal Genetics.

Prevalence of Virulence Genes in Extended-Spectrum β-lactamases (ESBLs)-Producing Salmonella in Retail Raw Chicken in China.

PubMed

Qiao, Jing; Alali, Walid Q; Liu, Jiangshan; Wang, Yaping; Chen, Sheng; Cui, Shenghui; Yang, Baowei

2018-04-01

Extended-spectrum β-lactamases (ESBLs)-producing Salmonella is a tremendous hazard to food safety and public health. The objective of this study was to determine the prevalence of 30 virulence genes (avrA, sipA, sseC, marT, rhuM, siiE, pipA, pipD, envR, gogB, gtgA, sodC1, sseI, irsA, sopE2, spvC, rck, spvR, fhuA, msgA, pagK, srfj, stkc, fimA, lpfD, pefA, stcC, steB, stjB, and tcfA) in 156 ESBLs-producing Salmonella isolates that belonged to 21 serotypes. These isolates were recovered from retail raw chicken samples collected from 5 provinces and 2 national cities in China between 2007 and 2012. The results indicated that 154 (98.7%) ESBLs-producing Salmonella isolates carried at least 1 virulence gene, 138 (88.5%) simultaneously carried at least 5 virulence genes, 107 (68.6%) carried 10 or more, and 20 (12.8%) carried 15 or more virulence genes. The most frequently detected virulence genes were marT (n = 127, 81.4%), siiE (n = 126, 80.8%), msgA (n = 121, 77.6%), and sipA (n = 121, 77.6%). Significant difference was identified between detection percentages of virulence genes of rhuM, pipD, envR, sopE2, pagK, lpfD, steB, and stjB in S. Indiana, S. Thompson, S. Enteritidis, S. Typhimurium, S. Shubra, S. Edinburg, and S. Agona isolates. Distribution of virulence genes were significantly influenced by sampling districts (P < 0.01), especially for sodC1 and pipD, and then were msgA and sopE2. The heatmap showed the frequencies of virulence genes in ESBLs-producing isolates from retail chickens in southern, central, and northern regions of China were completely different from each other. Based on our findings, ESBLs-producing Salmonella of retail chicken origin were common carriers of multiple virulence genes and were regionally distributed. © 2018 Institute of Food Technologists®.

Comparison of 7 culture methods for Salmonella serovar Enteritidis and Salmonella serovar Typhimurium isolation in poultry feces.

PubMed

Rodríguez, Francisco I; Procura, Francisco; Bueno, Dante J

2018-06-26

The present work compared 7 different culture methods and 3 selective-differential plating media for Salmonella ser. Enteritidis (SE) and S. ser. Typhimurium (ST) isolation using artificially contaminated poultry feces. The sensitivity (Se) and accuracy (AC) values increased when Modified Semisolid Rappaport Vassiliadis (MSRV) methods were used in place of the Tetrathionate (TT) or Tetrathionate Hajna broth (TTH) method in the enrichment step. However, there was no significant difference between the pre-enrichment incubation at 4 to 6 and 18 to 24 h for MSRV5 and MSRV24 methods, respectively. All Salmonella strains were recovered in the lowest dilutions tested for MSRV24 and 3 out of 4 for MSRV5 methods (2 to 10 cfu/25 g). The TT and TTH methods showed a detection limit between 2.2 × 101 and 1.0 × 106 cfu/25 g of fecal sample. The agreement was variable between the methods. However, there was a very good agreement between the MSRV5 and MSRV24 methods, and between tetrathionate direct (TTD, no pre-enrichment media used) and buffered peptone water 18 to 24 h Tetrathionate broth combination (TT24 method) for Salmonella strains. The 3 selective-differential plating media showed an agreement between fair and excellent. They performed a high Se and AC in the MSRV methods for Salmonella strains. There was a significant difference between center and periphery for MSRV methods, and there was a fair agreement between them for all strains. The MSRV methods are better than TT/TTH methods for the isolation of different strains of SE and ST in poultry fecal samples. The MSRV5 method can be used to reduce the time for the detection of SE and ST in these samples. Furthermore, a loopful of the periphery of the growth should be streaked onto differential-selective plating media, even in the absence of halo, to decrease the number of false negative results.

Label-free SERS detection of Salmonella Typhimurium on DNA aptamer modified AgNR substrates

USDA-ARS?s Scientific Manuscript database

Salmonella Typhimurium is an important foodborne pathogen which causes gastroenteritis in both humans and animals. Currently available rapid methods have relied on antibodies to offer specific recognition of the pathogen from the background. As a substitute of antibodies, nucleic acid aptamers offer...

Intermediate Susceptibility to Ciprofloxacin among Salmonella enterica Serovar Typhi Isolates in Lima, Peru

PubMed Central

Lejon, Veerle; Horna, Gertrudis; Astocondor, Lizeth; Vanhoof, Raymond; Bertrand, Sophie; Jacobs, Jan

2014-01-01

Thirty-three Salmonella enterica serovar Typhi blood isolates from Lima, Peru (2008 to 2012), were fully susceptible to trimethoprim-sulfamethoxazole, chloramphenicol, ceftriaxone, and tetracycline; 8/33 (24.2%) showed intermediate susceptibility to ciprofloxacin carrying mutations in the quinolone resistance-determining region of the gyrA gene (Ser83-Phe and Asp87-Asn) and in the gyrB gene (Ser464-Phe). PMID:24371234

Surface enhaced raman scattering (SERS) with biopolymer encapsulated silver nanosubstrates for rapid detection of foodborne pathogens

USDA-ARS?s Scientific Manuscript database

A biopolymer encapsulated with silver nanoparticles was prepared using polyvinyl alcohol (PVA) solution, silver nitrate, and trisodium citrate. Biopolymer based nanosubstrates were deposited on a mica sheet for SERS. Fresh cultures of Salmonella Typhimurium, Escherichia coli, Staphylococcus aureus a...

Comparison of a novel strategy for the detection and isolation of Salmonella in shell eggs with the Food and Drug Administration Bacteriological Analytical Manual method.

PubMed

Zhang, Guodong; Thau, Eve; Brown, Eric W; Hammack, Thomas S

2013-12-01

The current FDA Bacteriological Analytical Manual (BAM) method for the detection of Salmonella in eggs requires 2 wk to complete. The objective of this project was to improve the BAM method for the detection and isolation of Salmonella in whole shell eggs. A novel protocol, using 1,000 g of liquid eggs for direct preenrichment with 2 L of tryptic soy broth (TSB) followed by enrichment using Rappaport-Vassiliadis and Tetrathionate broths, was compared with the standard BAM method, which requires 96 h room temperature incubation of whole shell egg samples followed by preenrichment in TSB supplemented with FeSO4. Four Salmonella ser. Enteritidis (4 phage types) and one Salmonella ser. Heidelberg isolates were used in the study. Bulk inoculated pooled liquid eggs, weighing 52 or 56 kg (approximately 1,100 eggs) were used in each trial. Twenty 1,000-g test portions were withdrawn from the pooled eggs for both the alternative and the reference methods. Test portions were inoculated with Salmonella at 1 to 5 cfu/1,000 g eggs. Two replicates were performed for each isolate. In the 8 trials conducted with Salmonella ser. Enteritidis, the alternative method was significantly (P < 0.05) more productive than the reference method in 3 trials, and significantly (P < 0.05) less productive than the reference method in 1 trial. There were no significant (P < 0.05) differences between the 2 methods for the other 4 trials. For Salmonella ser. Heidelberg, combined data from 2 trials showed the alternative method was significantly (P < 0.05) more efficient than the BAM method. We have concluded that the alternative method, described herein, has the potential to replace the current BAM culture method for detection and isolation of Salmonella from shell eggs based on the following factors: 1) the alternative method is 4 d shorter than the reference method; 2) it uses regular TSB instead of the more complicated TSB supplemented with FeSO4; and 3) it was equivalent or superior to the

Popcorn-shaped magnetic core-plasmonic shell multifunctional nanoparticles for the targeted magnetic separation and enrichment, label-free SERS imaging, and photothermal destruction of multidrug-resistant bacteria.

PubMed

Fan, Zhen; Senapati, Dulal; Khan, Sadia Afrin; Singh, Anant Kumar; Hamme, Ashton; Yust, Brian; Sardar, Dhiraj; Ray, Paresh Chandra

2013-02-18

Over the last few years, one of the most important and complex problems facing our society is treating infectious diseases caused by multidrug-resistant bacteria (MDRB), by using current market-existing antibiotics. Driven by this need, we report for the first time the development of the multifunctional popcorn-shaped iron magnetic core-gold plasmonic shell nanotechnology-driven approach for targeted magnetic separation and enrichment, label-free surface-enhanced Raman spectroscopy (SERS) detection, and the selective photothermal destruction of MDR Salmonella DT104. Due to the presence of the "lightning-rod effect", the core-shell popcorn-shaped gold-nanoparticle tips provided a huge field of SERS enhancement. The experimental data show that the M3038 antibody-conjugated nanoparticles can be used for targeted separation and SERS imaging of MDR Salmonella DT104. A targeted photothermal-lysis experiment, by using 670 nm light at 1.5 W cm(-2) for 10 min, results in selective and irreparable cellular-damage to MDR Salmonella. We discuss the possible mechanism and operating principle for the targeted separation, label-free SERS imaging, and photothermal destruction of MDRB by using the popcorn-shaped magnetic/plasmonic nanotechnology. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of a broad host-spectrum virulent Salmonella bacteriophage fmb-p1 and its application on duck meat.

PubMed

Wang, Changbao; Chen, Qiming; Zhang, Chong; Yang, Jie; Lu, Zhaoxin; Lu, Fengxia; Bie, Xiaomei

2017-05-15

The aim of this study was to find a virulent bacteriophage for the biocontrol of Salmonella in duck meat. A broad host-spectrum virulent phage, fmb-p1, was isolated and purified from an duck farm, and its host range was determined to include S. Typhimurium, S. Enteritidis, S. Saintpaul, S. Agona, S. Miami, S. Anatum, S. Heidelberg and S. Paratyphi-C. Electron microscopy and genome sequencing showed that fmb-p1 belongs to the family Siphoviridae. The genome of fmb-p1 is composed of a 43,327-bp double-stranded DNA molecule with 60 open reading frames and a total G+C content of 46.09%. There are no deleterious sequences or genes encoding known harmful products in the phage fmb-p1 genome. Phage fmb-p1 was stable under different temperature (40-75°C), pH (4-10) and NaCl solutions (1-11%). The phage treatment (9.9×10 9 PFU/cm 2 ) caused a peak reduction in S. Typhimurium of 4.52 log CFU/cm 2 in ready-to-eat (RTE) duck meat, whereas potassium sorbate treatment (PS, 2mg/cm 2 ) resulted in a 0.05-0.12 log reduction. Compared to PS treatment, there was significant difference in the S. Typhimurium reduction (P˂0.05) by phage treatment at both 4°C and 25°C. The results suggested that phage could be applied to reduce Salmonella, on commercial poultry products. Copyright © 2017 Elsevier B.V. All rights reserved.

Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in southern Brazil

PubMed Central

Pulido-Landínez, M; Sánchez-Ingunza, R; Guard, J; do Nascimento, V Pinheiro

2013-01-01

To assess diversity of Salmonella enterica serotypes present in poultry and their environment from southern Brazil, the Kauffmann–White–Le Minor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked intergenic sequence ribotyping (ISR) region that assesses single nucleotide polymorphisms occurring around a 5S ribosomal gene. Serotypes identified were Heidelberg (40·6%), Enteritidis (34·2%), Hadar (8·4%), Typhimurium (3·9%), Gallinarum (3·2%), Agona (1·3%), Cerro (1·3%), Livingstone (1·3%), Infantis (0·6%), Isangi (0·6%), Mbandaka (0·6%), Montevideo (0·6%) and Senftenberg (0·6%). Three unique ISRs were detected from four strains. Day old chicks yielded only S. Enteritidis, whereas S. Heidelberg was most often associated with poultry carcasses. Overall agreement between KWL and ISR was 85·2%, with disagreement possibly due to the ability of ISR to detect mixtures of serotypes in culture. Overall, ISR provided more information than did KWL about the ecology of Salm. enterica on-farm. The O-antigen group D Salm. enterica serovars such as Pullorum, Gallinarum and Enteritidis appear susceptible to overgrowth by other serotypes. Significance and Impact of the Study Single nucleotide polymorphisms found in a group of poultry-associated Salmonella isolates from southern Brazil provided evidence of mixtures of serovar group D serotypes on-farm and in single samples from birds. This finding suggests that co-infection and interserotype competition of Salmonella enterica in poultry could impact the incidence of disease in animals or humans. In addition, unique serotypes were identified on-farm that escaped characterization by antibody typing. Application of cost-efficient and highly discriminatory genomic methods for assigning serotype may alter concepts about the epidemiology of Salm. enterica on-farm and in foods. PMID:23734786

Differential antibacterial response of chicken granulosa cells to invasion by Salmonella serovars.

PubMed

Babu, Uma S; Harrison, Lisa M; Patel, Isha R; Ramirez, Gerardo A; Williams, Kristina M; Pereira, Marion; Balan, Kannan V

2016-06-01

In the United States, Salmonella enterica ser. Enteritidis (SE) is among the leading bacterial cause of foodborne illness via consumption of raw or undercooked eggs. The top Salmonella serovars implicated in U.S. foodborne outbreaks associated with chicken consumption include SE, Typhimurium (ST), Heidelberg (SH), Montevideo, Mbandka, Braenderup, and Newport. While enforcement actions target the eradication of SE from layer hens, there is a growing concern that other serovars could occupy this niche and be a cause of egg-transmitted human salmonellosis. Therefore, we tested the invasion and survival of SE, SH, ST, and Salmonella enterica ser. Hadar (S. Hadar) at 4 and 20 h post infection (hpi) in chicken ovarian granulosa cells (cGC); a cellular layer which surrounds the previtelline layer and central yolk in egg-forming follicles. We also evaluated cGC transcriptional changes, using an antibacterial response PCR array, to assess host response to intracellular SalmonellaWe observed that invasion of cGC by SE, SH, and ST was significantly higher than invasion by S. Hadar, with ST showing the highest level of invasion. The Bacterial Survival Index, defined as the ratio of intracellular bacteria at 20 and 4 h, were 18.94, 7.35, and 15.27 for SE, SH, and ST, respectively, with no significant difference in survival between SE or ST compared to SH. Evaluation of cGC anti-Salmonella gene responses indicated that at 4 hpi there was a significant decrease in Toll-like receptor (TLR)-4 mRNA in cGC infected with SE, whereas TLR5 and myeloid differentiation primary response gene 88 were significantly down regulated across all serovars. At 4 hpi, invasion by Salmonella serovars resulted in significant upregulation of several antimicrobial genes, and proinflammatory cytokines and chemokines (PICs). At 20 hpi, all the serovars induced PICs with SH being the strongest inducer. Additionally, SE, SH and ST differentially induced signal transduction pathways. Although only a single

Surface enhanced raman spectroscopy technique in rapid detection of live and dead salmonella cells

USDA-ARS?s Scientific Manuscript database

Many research proved that Surface Enhanced Raman Spectroscopy (SERS) can detect pathogens rapidly and accurately. In this study, a silver metal substrate was used for the selected common food pathogen Salmonella typhimurium bacteria. Nano silver rods were deposited on a thin titanium coating over t...

Antimicrobial resistance patterns of bovine Salmonella enterica isolates submitted to the Wisconsin Veterinary Diagnostic Laboratory: 2006-2015.

PubMed

Valenzuela, J R; Sethi, A K; Aulik, N A; Poulsen, K P

2017-02-01

Salmonellosis on the dairy continues to have a significant effect on animal health and productivity and in the United States. Additionally, Salmonella enterica ssp. enterica causes an estimated 1.2 million cases of human illness annually. Contributing to the morbidity and mortality in both human and domestic animal species is emergence of antimicrobial resistance by Salmonella species and increased incidence of multidrug-resistant isolates. This study describes serotype distribution and the antimicrobial resistance patterns for various Salmonella serotypes isolated from bovine samples submitted to the Wisconsin Veterinary Diagnostic Laboratory (WVDL) over the past 10 yr. Salmonella serotyping and antimicrobial susceptibility testing data were obtained from the laboratory information management system at WVDL. Data from accessions were limited to bovine samples submitted to the WVDL between January 2006 and June 2015 and those that had both a definitive serotype and complete results for antimicrobial susceptibility testing. A total of 4,976 isolates were identified. Salmonella enterica ser. Dublin was the most prevalent serotype identified among bovine samples submitted to the WVDL, accounting for a total of 1,153 isolates (23% of total isolates) over the study period. Along with Dublin, Salmonella enterica ser. Cerro (795, 16%), Newport (720, 14%), Montevideo (421, 8%), Kentucky (419, 8%), and Typhimurium (202, 4%) comprised the top 6 most commonly isolated serotypes during that time. Overall, resistance of bovine Salmonella isolates in the study population remained stable, although decreases in resistance were noted for gentamicin, neomycin, and trimethoprim sulfamethoxazole during the study period. All isolates remained susceptible to enrofloxacin. These data show that antimicrobial susceptibility for bovine Salmonella has changed in the population served by WVDL in the past 10 yr. This information is important for understanding Salmonella disease ecology in

OXA-48 carbapenemase-producing Salmonella enterica serovar Kentucky isolate of sequence type 198 in a patient transferred from Libya to Switzerland.

PubMed

Seiffert, Salome N; Perreten, Vincent; Johannes, Sönke; Droz, Sara; Bodmer, Thomas; Endimiani, Andrea

2014-01-01

Here, we report a case of OXA-48-producing Salmonella enterica serovar Kentucky of sequence type 198 (ST198) from perianal screening cultures of a patient transferred from Libya to Switzerland. The blaOXA-48 gene was carried by Tn1999.2 and located on an ∼60-kb IncL/M plasmid. This Salmonella strain also possessed the blaVEB-8, aac(6)-Ib, tet(A), sul1, and mphA resistance genes and substitutions in GyrA (Ser83Phe and Asp87Asn) and ParC (Ser80Ile). This finding emphasizes that prompt screening strategies are essential to prevent the dissemination of carbapenemase producers imported from countries where they are endemic.

Salmonella prevalence among reptiles in a zoo education setting.

PubMed

Hydeskov, H B; Guardabassi, L; Aalbaek, B; Olsen, K E P; Nielsen, S S; Bertelsen, M F

2013-06-01

Clinically healthy reptiles may shed Salmonella and therefore act as a potential zoonotic threat. Most people in Northern European countries are rarely exposed to reptiles, but many zoos have education departments where children have direct contact with this group of animals. The objectives of this study were to determine the prevalence and serotype distribution of Salmonella among reptiles in the Education Department (n = 55) at Copenhagen Zoo and compare it to the Zoo's main reptile collection (n = 145) to evaluate the zoonotic risk. Salmonella was isolated from cloacal swabs by selective enrichment, and a single isolate from each positive sample was further identified by biochemical tests and serotyped. The overall prevalence was 35% (69/200) with significant difference between the Education Department (64%, 35/55) and the main reptile collection (23%, 34/145). A total of 28 serotypes were detected. Ten serotypes were isolated from more than one specimen and four from more than one species. Salmonella enterica subsp. enterica serovar Eastbourne was the predominant serotype (32%, 22/69) and was also the serotype isolated from most reptile species (n = 7). Transmission of serotypes from one department to another was very limited indicated by the serotype distribution. Despite the relative high prevalence observed among the reptiles in the Zoo's Education Department compared to the reptiles in the Zoo's main reptile collection, no Salmonella cases have been linked to the Zoo, and Salmonella ser. Eastbourne is very rarely isolated from humans in Denmark. Simple hygienic procedures such as hand washing which is consistently carried out following handling of reptiles at the Education Department may reduce the risk and therefore contribute to this low prevalence. © 2012 Blackwell Verlag GmbH.

ESBL-Producing Salmonella enterica Serovar Typhi in Traveler Returning from Guatemala to Spain

PubMed Central

Piedra-Carrasco, Nuria; Salvador, Fernando; Rodríguez, Virginia; Sánchez-Montalvá, Adrián; Planes, Anna M.; Molina, Israel; Larrosa, M. Nieves

2014-01-01

We report a case of typhoid fever in a traveler returning to Spain from Guatemala that was caused by Salmonella enterica serovar Typhi which produced an extended-spectrum β-lactamase (ESBL). This finding demonstrates the presence of ESBL-producing S. enterica ser. Typhi strains in the Americas. Enhanced surveillance is necessary to prevent further spread. PMID:25340972

Dissemination of antimicrobial-resistant clones of Salmonella enterica among domestic animals, wild animals, and humans.

PubMed

Palomo, Gonzalo; Campos, Maria Jorge; Ugarte, María; Porrero, María Concepción; Alonso, Juan Manuel; Borge, Carmen; Vadillo, Santiago; Domínguez, Lucas; Quesada, Alberto; Píriz, Segundo

2013-02-01

Non-typhoidal salmonellosis is an important zoonotic disease caused by Salmonella enterica. This work focuses on the identification of Salmonella enterica clonal strains which, presenting a wide distribution potential, express resistance determinants that compromise effectiveness of the antimicrobial therapy. The screening was performed on 506 Salmonella enterica isolates from animals and humans, which were characterized by serovar and phage typing, genome macrorestriction and pulsed-field gel electrophoresis, and detection of phenotypic and genotypic traits for antimicrobial resistance. A Salmonella Enteritidis strain with strong quinolone resistance is spread on three host environments carrying one of the four variants found for the GyrA protein: (1) Asp87Tyr, the major polymorphism found in 39 Salmonella isolates from human origin and six from poultry; (2) Ser83Phe, with four isolates from human origin and one from white stork (Ciconia ciconia); and (3) Asp87Asn or (4) Asp87Gly, with two isolates each from human origins. Several Salmonella Typhimurium strains that presented int1 elements and the classically associated pentaresistance (ACSSuT) phenotype were found distributed between two host environments: domestic animals and humans, domestics and wild animals, or wild fauna plus humans. This study points out the importance of monitoring gut microbiota and its antimicrobial resistance from wildlife, in parallel to livestock animals and humans, especially for animal species that are in close contact with people.

Irrigation water quality and the benefits of implementing good agricultural practices during tomato (Lycopersicum esculentum) production.

PubMed

Estrada-Acosta, M; Jiménez, M; Chaidez, C; León-Félix, J; Castro-Del Campo, N

2014-07-01

The implementation of good agricultural practices (GAP) from irrigation water to the tomato packaging process enhances the safety of fresh produce and its value throughout the food chain. The aim of the present study was to show that fresh produce farms that apply and enforce GAP could reduce the presence of Salmonella in finished produce. Samples were collected biweekly from six packing houses from the central region of Sinaloa, México, for the isolation of Salmonella spp by the ISO 6579:2002 method, and the isolated strains were serotyped and genotyped by the Kauffmman-White scheme and pulsed field gel electrophoresis (PFGE), respectively. Salmonella strains were detected in 13 (36.1 %) irrigation water samples, while only two tomato samples were positive (5.5 %). Eight different serotypes were identified in irrigation water, and Salmonella Oranienburg (34 %) was the most prevalent; however, only Salmonella Agona and Salmonella Weltevreden were present on tomatoes. Salmonella Oranienburg was the most widely dispersed and variable serotype, with 10 different PFGE profiles. Salmonella Weltevreden was isolated from both types of samples, albeit with distinct genetic profiles, implying that the sources of contamination differ. These results confirm the utility of implementing good agricultural practices to reduce Salmonella contamination in irrigation water and the packaging process.

[Study on national active monitoring for food borne pathogens and antimicrobial resistance in China 2001].

PubMed

Wang, Maoqi; Ran, Lu; Wang, Zhutian; Li, Zhigang

2004-01-01

To survey food borne pathogens and antimicrobial resistance in China. A total of 4034 samples of foods (raw meats, raw milk, cooked meats, ice cream, yoghurt, aquatic product and vegetable) were examined for the presence of Escherichia coli O157:H7 Salmonella spp and Listeria monocytogens by national active foodborne pathogens surveillance system. The samples were obtained from 11 provinces in 2001. Approximate 5.50% of the all samples yielded 3 pathogenes, whereas Escherichia coli O157:H7 (0.82%), Salmonella servoars (3.32%) and Listeria monocytogens (1.29%). The most heavy contamination by three food borne pathogens are in raw meat (12.96%). Top seven serotype of the 137 Salmonella isolates are S. derby, S. agona, S. enteritidis, S. reading, S. anatum. S. muenster, S. typhimurium. Serotypes and antibiotic resistance patterns of Salmonella isolates are different in 11 provinces. E. coli O157:H7 strains that are isolated from raw meat and cooked meat have VT2, eae, Hly genes. Salmonella and E. coli strains of multidrug resistance were isolated and identified.

[Salmonella].

PubMed

Amo, Kiyoko

2012-08-01

Nontyphoidal salmonella causes infectious gastroenteritis, and sometimes causes bacteremia and meningitis. Gastroenteritis associated with nontyphoidal salmonella, in which fever, diarrhea, vomiting and abdominal cramps, is a common disease. The major way of transmittion is food of animal origin, for example egg. That is the reason why precausion is so important such as wash hands before cooking, avoid eating raw egg and wash the cooking utensils after contact raw foods. In this report, I presented the rare severe case of encephalitis caused by salmonella infection.

Molecular epidemiology of fluoroquinolone resistant Salmonella in Africa: A systematic review and meta-analysis

PubMed Central

Tessema, Tesfaye S.; Beyene, Getenet; Aseffa, Abraham

2018-01-01

Background Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of this study were to assess the heterogeneity, estimate pooled proportions and describe the preponderance of FQ-resistance determinants in typhoidal and non-typhoidal Salmonella (NTS) isolates of Africa. Methods Genetic and phenotypic data on 6103 Salmonella isolates were considered. Meta- and frequency analyses were performed depending on the number of studies by category, number of isolates and risks of bias. A random effects model was used to assess heterogeneity and estimate pooled proportions. Relative and cumulative frequencies were calculated to describe the overall preponderance of FQ-resistance determinants in quinolone resistant isolates. Results The pooled proportion of gyrA mutants (Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Salmonella enterica serovar Enteritidis) was estimated at 5.7% (95% Confidence interval (CI) = 2.6, 9.8; Tau squared (T2) = 0.1105), and was higher in S. Typhi than in S. Typhimurium (odds ratio (OR) = 3.3, 95%CI = 2, 5.7). The proportions of each of gyrB and parC mutants, and strains with Plasmid Mediated Quinolone Resistance genes (qnrA, qnrB and qnrS) were low (≤ 0.3%). Overall, 23 mutant serotypes were identified, and most strains had mutations at codons encoding Ser83 and Asp87 of gyrA (82%, 95%CI = 78, 86). Conclusions Mutations at gyrA appear to account for ciprofloxacin non-susceptibility in most clinical Salmonella strains in Africa. The estimates could be harnessed to develop a mismatch-amplification mutation-assay for the detection of FQ-resistant strains in Africa. PMID:29432492

Molecular epidemiology of fluoroquinolone resistant Salmonella in Africa: A systematic review and meta-analysis.

PubMed

Tadesse, Getachew; Tessema, Tesfaye S; Beyene, Getenet; Aseffa, Abraham

2018-01-01

Wide-ranging evidence on the occurrence of fluoroquinolone (FQ) resistance genetic determinants in African Salmonella strains is not available. The main objectives of this study were to assess the heterogeneity, estimate pooled proportions and describe the preponderance of FQ-resistance determinants in typhoidal and non-typhoidal Salmonella (NTS) isolates of Africa. Genetic and phenotypic data on 6103 Salmonella isolates were considered. Meta- and frequency analyses were performed depending on the number of studies by category, number of isolates and risks of bias. A random effects model was used to assess heterogeneity and estimate pooled proportions. Relative and cumulative frequencies were calculated to describe the overall preponderance of FQ-resistance determinants in quinolone resistant isolates. The pooled proportion of gyrA mutants (Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Salmonella enterica serovar Enteritidis) was estimated at 5.7% (95% Confidence interval (CI) = 2.6, 9.8; Tau squared (T2) = 0.1105), and was higher in S. Typhi than in S. Typhimurium (odds ratio (OR) = 3.3, 95%CI = 2, 5.7). The proportions of each of gyrB and parC mutants, and strains with Plasmid Mediated Quinolone Resistance genes (qnrA, qnrB and qnrS) were low (≤ 0.3%). Overall, 23 mutant serotypes were identified, and most strains had mutations at codons encoding Ser83 and Asp87 of gyrA (82%, 95%CI = 78, 86). Mutations at gyrA appear to account for ciprofloxacin non-susceptibility in most clinical Salmonella strains in Africa. The estimates could be harnessed to develop a mismatch-amplification mutation-assay for the detection of FQ-resistant strains in Africa.

Characterization of multidrug-resistant Salmonella enterica serovar Heidelberg from a ground turkey-associated outbreak in the United States in 2011

USDA-ARS?s Scientific Manuscript database

In March 2011, a multi-state outbreak of Salmonella enterica ser. Heidelberg infections was investigated. Pulsed-field gel electrophoresis (PFGE) analysis of isolates from suspected cases and an epidemiologic investigation identified 136 case patients from 34 states from February to September. Two...

Comparison of CHROMagar Salmonella Medium and Xylose-Lysine-Desoxycholate and Salmonella-Shigella Agars for Isolation of Salmonella Strains from Stool Samples

PubMed Central

Maddocks, Susan; Olma, Tom; Chen, Sharon

2002-01-01

The growth and appearance of 115 stock Salmonella isolates on a new formulation of CHROMagar Salmonella (CAS) medium were compared to those on xylose-lysine-desoxycholate agar (XLD), Salmonella-Shigella agar (SS), and Hektoen enteric agar (HEA) media. CAS medium was then compared prospectively to XLD and SS for the detection and presumptive identification of Salmonella strains in 500 consecutive clinical stool samples. All stock Salmonella isolates produced typical mauve colonies on CAS medium. Nine Salmonella strains were isolated from clinical specimens. The sensitivities for the detection of salmonellae after primary plating on CAS medium and the combination of XLD and SS after enrichment were 100%. The specificity for the detection of salmonellae after primary plating on CAS medium (83%) was significantly (P < 0.0001) higher than that after primary plating on the combination of SS and XLD media (55%) (a 28% difference in rates; 95% confidence interval, 23.0 to 34%). Twenty-nine non-Salmonella organisms produced mauve colonies on CAS medium, including 17 Candida spp. (59%) and 8 Pseudomonas spp. (28%). These were easily excluded as salmonellae by colony morphology, microscopic examination of a wet preparation, or oxidase testing. One biochemically inert Escherichia coli isolate required further identification to differentiate it from Salmonella spp. The use of plating on CAS medium demonstrated high levels of sensitivity and specificity and reduced the time to final identification of Salmonella spp., resulting in substantial cost savings. It can be recommended for use for the primary isolation of Salmonella spp. from stool specimens. Other media (e.g., XLD) are required to detect Shigella spp. concurrently. PMID:12149365

Influence of On-farm pig Salmonella status on Salmonella Shedding at Slaughter.

PubMed

Casanova-Higes, A; Andrés-Barranco, S; Mainar-Jaime, R C

2017-08-01

The risk of Salmonella shedding among pigs at slaughter with regard to their previous on-farm Salmonella status was assessed in a group of pigs from a farm from NE of Spain. A total of 202 pigs that had been serologically monitored monthly during the fattening period and from which mesenteric lymph nodes (MLN) and faecal (SFEC) samples were collected at slaughter for Salmonella isolation were included. A repeated-measures anova was used to assess the relationship between mean OD% values during the fattening period and sampling time and bacteriology on MLN and SFEC. Pigs were also grouped into four groups, that is pigs seronegative during the fattening period and Salmonella negative in MLN (group A; n = 69); pigs seronegative during the fattening period but Salmonella positive in MLN (B; n = 36); pigs seropositive at least once and Salmonella positive in MLN (C; n = 50); and pigs seropositive at least once but Salmonella negative in (D; n = 47). Pigs shedding at slaughter seroconverted much earlier and showed much higher mean OD% values than non-shedders pigs. The proportion of Salmonella shedders in groups A and D was high and similar (26.1% and 29.8%, respectively), but significantly lower than that for groups B and C. The odds of shedding Salmonella for groups B and C were 4.8 (95% CI = 1.5-15.5) and 20.9 (3.7-118) times higher, respectively, when compared to A. It was concluded that a large proportion of Salmonella seronegative pigs may shed Salmonella at slaughter, which would be likely associated to previous exposure with contaminated environments (i.e. transport and lairage). For pigs already infected at farm, the likelihood of shedding Salmonella was much higher and may depend on whether the bacterium has colonized the MLN or not. The odds of shedding Salmonella spp. were always much higher for pigs in which Salmonella was isolated from MLN. © 2016 Blackwell Verlag GmbH.

Low-oxygen tensions found in Salmonella-infected gut tissue boost Salmonella replication in macrophages by impairing antimicrobial activity and augmenting Salmonella virulence.

PubMed

Jennewein, Jonas; Matuszak, Jasmin; Walter, Steffi; Felmy, Boas; Gendera, Kathrin; Schatz, Valentin; Nowottny, Monika; Liebsch, Gregor; Hensel, Michael; Hardt, Wolf-Dietrich; Gerlach, Roman G; Jantsch, Jonathan

2015-12-01

In Salmonella infection, the Salmonella pathogenicity island-2 (SPI-2)-encoded type three secretion system (T3SS2) is of key importance for systemic disease and survival in host cells. For instance, in the streptomycin-pretreated mouse model SPI-2-dependent Salmonella replication in lamina propria CD11c(-)CXCR1(-) monocytic phagocytes/macrophages (MΦ) is required for the development of colitis. In addition, containment of intracellular Salmonella in the gut critically depends on the antimicrobial effects of the phagocyte NADPH oxidase (PHOX), and possibly type 2 nitric oxide synthase (NOS2). For both antimicrobial enzyme complexes, oxygen is an essential substrate. However, the amount of available oxygen upon enteroinvasive Salmonella infection in the gut tissue and its impact on Salmonella-MΦ interactions was unknown. Therefore, we measured the gut tissue oxygen levels in a model of Salmonella enterocolitis using luminescence two-dimensional in vivo oxygen imaging. We found that gut tissue oxygen levels dropped from ∼78 Torr (∼11% O2) to values of ∼16 Torr (∼2% O2) during infection. Because in vivo virulence of Salmonella depends on the Salmonella survival in MΦ, Salmonella-MΦ interaction was analysed under such low oxygen values. These experiments revealed an increased intracellular replication and survival of wild-type and t3ss2 non-expressing Salmonella. These findings were paralleled by blunted nitric oxide and reactive oxygen species (ROS) production and reduced Salmonella ROS perception. In addition, hypoxia enhanced SPI-2 transcription and translocation of SPI-2-encoded virulence protein. Neither pharmacological blockade of PHOX and NOS2 nor impairment of T3SS2 virulence function alone mimicked the effect of hypoxia on Salmonella replication under normoxic conditions. However, if t3ss2 non-expressing Salmonella were used, hypoxia did not further enhance Salmonella recovery in a PHOX and NOS2-deficient situation. Hence, these data suggest that

Wild-Caught and Farm-Reared Amphibians are Important Reservoirs of Salmonella, A Study in North-East Thailand.

PubMed

Ribas, A; Poonlaphdecha, S

2017-03-01

The role of amphibians as Salmonella reservoirs has not been as well studied as in reptiles, where the literature is abundant. Recent outbreaks of salmonellosis associated with exotic pet frogs have occurred in United States. Frog farming and wild frog harvesting have increased the international trade in these species. This necessitates a better understanding of the risk of salmonellosis transmission from amphibians to humans. We explored the presence of Salmonella in amphibians (frogs and toads) in Thailand, where farmed and wild frogs as well as toads are present. These live animals are easily found in the local markets and are used as food. Exportation of frog meat from Thailand is common. During March-June 2014, ninety-seven frogs were collected from several habitats, including frog farms, urban areas and protected natural areas. The collected amphibians were tested for the presence of Salmonella. The overall prevalence of Salmonella was 69.07% (90.00% in farm animals, 0% in urban area animals and 44.83% in protected area animals). Eight serovars of Salmonella were isolated: subsp. diarizonae ser. 50:k:z, Hvittingfoss, Muenchen, Newport, Stanley, Thompson, Panama and Wandsworth. Six of the identified serovars, Hvittingfoss, Newport, Panama, Stanley, Thompson and Wandsworth, have been detected in humans in Thailand. According to our results, amphibians are reservoirs of Salmonella and can be a public health concern when used as a source of protein for humans. © 2016 Blackwell Verlag GmbH.

Salmonella Infections in Childhood.

PubMed

Bula-Rudas, Fernando J; Rathore, Mobeen H; Maraqa, Nizar F

2015-08-01

Salmonella are gram-negative bacilli within the family Enterobacteriaceae. They are the cause of significant morbidity and mortality worldwide. Animals (pets) are an important reservoir for nontyphoidal Salmonella, whereas humans are the only natural host and reservoir for Salmonella Typhi. Salmonella infections are a major cause of gastroenteritis worldwide. They account for an estimated 2.8 billion cases of diarrheal disease each year. The transmission of Salmonella is frequently associated with the consumption of contaminated water and food of animal origin, and it is facilitated by conditions of poor hygiene. Nontyphoidal Salmonella infections have a worldwide distribution, whereas most typhoidal Salmonella infections in the United States are acquired abroad. In the United States, Salmonella is a common agent for food-borne–associated infections. Several outbreaks have been identified and are most commonly associated with agricultural products. Nontyphoidal Salmonella infection is usually characterized by a self-limited gastroenteritis in immunocompetent hosts in industrialized countries, but it may also cause invasive disease in vulnerable individuals (eg, children less than 1 year of age, immunocompromised). Antibiotic treatment is not recommended for treatment of mild to moderate gastroenteritis by nontyphoidal Salmonella in immunocompetent adults or children more than 1 year of age. Antibiotic treatment is recommended for nontyphoidal Salmonella infections in infants less than 3 months of age, because they are at higher risk for bacteremia and extraintestinal complications. Typhoid (enteric) fever and its potential complications have a significant impact on children, especially those who live in developing countries. Antibiotic treatment of typhoid fever has become challenging because of the emergence of Salmonella Typhi strains that are resistant to classically used first-line agents: ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol. The

Inactivation of Salmonella Senftenberg, Salmonella Typhimurium and Salmonella Tennessee in peanut butter by 915 MHz microwave heating.

PubMed

Song, Won-Jae; Kang, Dong-Hyun

2016-02-01

This study evaluated the efficacy of a 915 MHz microwave with 3 different levels to inactivate 3 serovars of Salmonella in peanut butter. Peanut butter inoculated with Salmonella enterica serovar Senftenberg, S. enterica serovar Typhimurium and S. enterica serovar Tennessee were treated with a 915 MHz microwave with 2, 4 and 6 kW and acid and peroxide values and color changes were determined after 5 min of microwave heating. Salmonella populations were reduced with increasing treatment time and treatment power. Six kW 915 MHz microwave treatment for 5 min reduced these three Salmonella serovars by 3.24-4.26 log CFU/g. Four and two kW 915 MHz microwave processing for 5 min reduced these Salmonella serovars by 1.14-1.48 and 0.15-0.42 log CFU/g, respectively. Microwave treatment did not affect acid, peroxide, or color values of peanut butter. These results demonstrate that 915 MHz microwave processing can be used as a control method for reducing Salmonella in peanut butter without producing quality deterioration. Copyright © 2015 Elsevier Ltd. All rights reserved.

The relationship between the numbers of Salmonella Enteritidis, Salmonella Heidelberg, or Salmonella Hadar colonizing reproductive tissues of experimentally infected laying hens and deposition inside eggs.

PubMed

Gast, Richard K; Guraya, Rupa; Guard, Jean; Holt, Peter S

2011-06-01

Contamination of eggs by Salmonella Enteritidis has been a prominent cause of human illness for several decades and is the focus of a recently implemented national regulatory plan for egg-producing flocks in the United States. Salmonella Heidelberg has also been identified as an egg-transmitted pathogen. The deposition of Salmonella strains inside eggs is a consequence of reproductive tract colonization in infected laying hens, but prior research has not determined the relationship between the numbers of Salmonella that colonize reproductive organs and the associated frequency of egg contamination. In the present study, groups of laying hens in two trials were experimentally infected with large oral doses of strains of Salmonella Enteritidis (phage type 13a), Salmonella Heidelberg, or Salmonella Hadar. Reproductive tissues of selected hens were cultured to detect and enumerate Salmonella at 5 days postinoculation, and the interior contents of eggs laid between 6 and 25 days postinoculation were tested for contamination. Significantly more internally contaminated eggs were laid by hens infected with Salmonella Enteritidis (3.58%) than with strains of either Salmonella Heidelberg (0.47%) or Salmonella Hadar (0%). However, no significant differences were observed between Salmonella strains in either isolation frequency or the number of colony-forming units (CFU) isolated from ovaries or oviducts. Salmonella isolation frequencies ranged from 20.8% to 41.7% for ovaries and from 8.3% to 33.3% for oviducts. Mean Salmonella colonization levels ranged from 0.10 to 0.51 log CFU/g for ovaries and from 0.25 to 0.46 log CFU/g for oviducts. Although parallel rank-orders were observed for Salmonella enumeration (in both ovaries and oviducts) and egg contamination frequency, a statistically significant relationship could not be established between these two parameters of infection.

Impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the broiler crop and ceca.

PubMed

Buhr, R J; Bourassa, D V; Hinton, A; Fairchild, B D; Ritz, C W

2017-12-01

Research was conducted to evaluate the impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the crop and ceca following feed withdrawal. In 4 experiments, pens of broilers in separate rooms were challenged with marker strains of either Salmonella Montevideo or Salmonella Heidelberg. Three d post challenge, a 12-hour feed withdrawal was initiated, and one pen of broilers was switched between rooms for each Salmonella serotype. In experiments 3 and 4, non-challenged broilers also were added to the Salmonella challenge pens. The litter of each pen was sampled before and after the feed withdrawal period, the broilers euthanized, and the crop and ceca aseptically removed for Salmonella isolation. Results showed that only the challenge Salmonella serotype was recovered from the litter in challenge pens where broilers were not moved, while both Salmonella serotypes were recovered from the litter of the switched pens. Salmonella was recovered from 56/80 crops and from 66/80 ceca of challenged broilers that remained in the challenge pens. The challenge Salmonella serotype was recovered from 50/80 crops and from 60/80 ceca, and the switched pens' litter Salmonella serotype was recovered from 19/80 crops but not from the ceca in broilers challenged with Salmonella and then switched between pens. For experiments 3 and 4, Salmonella was recovered from 19/40 crops and from only 2/40 ceca from the non-challenged broilers placed into the Salmonella challenge pens. The results from broilers that were switched between Salmonella challenge pens indicate that the recovery of Salmonella from the crop of broilers following feed withdrawal (on Salmonella-contaminated litter) appears to depend mainly on the initial challenge Salmonella (62%) and less on the litter Salmonella (24%) status during the feed withdrawal period. In contrast, only the initial challenge Salmonella was recovered from the ceca (79%) from broilers that remained in challenge pens or

Salmonella Infections (For Parents)

MedlinePlus

... iguanas). Another, rarer form — called Salmonella typhi — causes typhoid fever . What Is Salmonella Infection? Salmonella infection, or salmonellosis , ... More on this topic for: Parents Kids Teens Typhoid Fever E. Coli Stool Test: Bacteria Culture Food Safety ...

Salmonella risk to consumers via pork is related to the Salmonella prevalence in pig feed.

PubMed

Rönnqvist, M; Välttilä, V; Ranta, J; Tuominen, P

2018-05-01

Pigs are an important source of human infections with Salmonella, one of the most common causes of sporadic gastrointestinal infections and foodborne outbreaks in the European region. Feed has been estimated to be a significant source of Salmonella in piggeries in countries of a low Salmonella prevalence. To estimate Salmonella risk to consumers via the pork production chain, including feed production, a quantitative risk assessment model was constructed. The Salmonella prevalence in feeds and in animals was estimated to be generally low in Finland, but the relative importance of feed as a source of Salmonella in pigs was estimated as potentially high. Discontinuation of the present strict Salmonella control could increase the risk of Salmonella in slaughter pigs and consequent infections in consumers. The increased use of low risk and controlled feed ingredients could result in a consistently lower residual contamination in pigs and help the tracing and control of the sources of infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

Control of Salmonella enterica serovar Enteritidis in laying hens by inactivated Salmonella Enteritidis vaccines

PubMed Central

de Freitas Neto, Oliveiro Caetano; Mesquita, Aline Lopes; de Paiva, Jaqueline Boldrin; Zotesso, Fábio; Berchieri Júnior, Angelo

2008-01-01

Salmonella Enteritidis is one of the agents that is responsible for outbreaks of human foodborne salmonellosis caused by Salmonella Enteritidis and is generally associated with the consumption of poultry products. Inactivated Salmonella Enteritidis cell vaccine is one of the available methods to control Salmonella Enteritidis in breeders and laying hens, however results in terms of efficacy vary. This vaccine has never been tested in Brazil, therefore, the present work was carried out to assess three commercial inactivated Salmonella Enteritidis vaccines allowed in Brazil. Four hundred white light variety commercial laying hens were obtained at one-day-of age. At eight weeks old, the birds were divided into four groups with one hundred animals each. Birds from three groups (V1, V2 and V3) received different intramuscular vaccines, followed by a booster dose at 16 weeks of age. Birds from another group (CG) were not vaccinated. When the laying hens were 20, 25 and 31 weeks old, 13 from each group were transferred to another room and were challenged by inoculating 2 mL neat culture of Salmonella Enteritidis. On the second day after each challenge, the caecal contents, spleen, liver and ovary of three birds from each group were analyzed for the presence of Salmonella Enteritidis. Twice a week a cloacal swab of each bird was taken and all eggs laid were examined for the presence of Salmonella Enteritidis. After four consecutive negative cloacal swabs in all the groups, the birds were sacrificed so as to examine the liver, caecal contents and ovaries. Overall, the inactivated vaccine used in group V3 reduced Salmonella Enteritidis in the feces and eggs. A very small amount of Salmonella was found in the spleen, liver, ovary and caeca of the birds in the four groups during the whole experiment. In general, inactivated Salmonella Enteritidis vaccines was able to decrease the presence of Salmonella Enteritidis in the birds and in the eggs as well. Nevertheless, they must

Use of Attenuated but Metabolically Competent Salmonella as a Probiotic To Prevent or Treat Salmonella Infection

PubMed Central

Sabag-Daigle, Anice; Blunk, Henry M.; Gonzalez, Juan F.; Steidley, Brandi L.; Boyaka, Prosper N.

2016-01-01

Salmonella enterica is among the most burdensome of foodborne disease agents. There are over 2,600 serovars that cause a range of disease manifestations ranging from enterocolitis to typhoid fever. While there are two vaccines in use in humans to protect against typhoid fever, there are none that prevent enterocolitis. If vaccines preventing enterocolitis were to be developed, they would likely protect against only one or a few serovars. In this report, we tested the hypothesis that probiotic organisms could compete for the preferred nutrient sources of Salmonella and thus prevent or treat infection. To this end, we added the fra locus, which encodes a utilization pathway for the Salmonella-specific nutrient source fructose-asparagine (F-Asn), to the probiotic bacterium Escherichia coli Nissle 1917 (Nissle) to increase its ability to compete with Salmonella in mouse models. We also tested a metabolically competent, but avirulent, Salmonella enterica serovar Typhimurium mutant for its ability to compete with wild-type Salmonella. The modified Nissle strain became more virulent and less able to protect against Salmonella in some instances. On the other hand, the modified Salmonella strain was safe and effective in preventing infection with wild-type Salmonella. While we tested for efficacy only against Salmonella Typhimurium, the modified Salmonella strain may be able to compete metabolically with most, if not all, Salmonella serovars, representing a novel approach to control of this pathogen. PMID:27185789

Two Novel Salmonella Bivalent Vaccines Confer Dual Protection against Two Salmonella Serovars in Mice

PubMed Central

Zhao, Xinxin; Dai, Qinlong; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Wang, Mingshu; Chen, Shun; Sun, Kunfeng; Yang, Qiao; Wu, Ying; Cheng, Anchun

2017-01-01

Non-typhoidal Salmonella includes thousands of serovars that are leading causes of foodborne diarrheal illness worldwide. In this study, we constructed three bivalent vaccines for preventing both Salmonella Typhimurium and Salmonella Newport infections by using the aspartate semialdehyde dehydrogenase (Asd)-based balanced-lethal vector-host system. The constructed Asd+ plasmid pCZ11 carrying a subset of the Salmonella Newport O-antigen gene cluster including the wzx-wbaR-wbaL-wbaQ-wzy-wbaW-wbaZ genes was introduced into three Salmonella Typhimurium mutants: SLT19 (Δasd) with a smooth LPS phenotype, SLT20 (Δasd ΔrfbN) with a rough LPS phenotype, and SLT22 (Δasd ΔrfbN ΔpagL::T araC PBAD rfbN) with a smooth LPS phenotype when grown with arabinose. Immunoblotting demonstrated that SLT19 harboring pCZ11 [termed SLT19 (pCZ11)] co-expressed the homologous and heterologous O-antigens; SLT20 (pCZ11) exclusively expressed the heterologous O-antigen; and when arabinose was available, SLT22 (pCZ11) expressed both types of O-antigens, while in the absence of arabinose, SLT22 (pCZ11) expressed only the heterologous O-antigen. Exclusive expression of the heterologous O-antigen in Salmonella Typhimurium decreased the swimming ability of the bacterium and its susceptibility to polymyxin B. Next, the crp gene was deleted from the three recombinant strains for attenuation purposes, generating the three bivalent vaccine strains SLT25 (pCZ11), SLT26 (pCZ11), and SLT27 (pCZ11), respectively. Groups of BALB/c mice (12 mice/group) were orally immunized with 109 CFU of each vaccine strain twice at an interval of 4 weeks. Compared with a mock immunization, immunization with all three vaccine strains induced significant serum IgG responses against both Salmonella Typhimurium and Salmonella Newport LPS. The bacterial loads in the mouse tissues were significantly lower in the three vaccine-strain-immunized groups than in the mock group after either Salmonella Typhimurium or Salmonella

Prevalence and Characterization of Salmonella enterica and Salmonella Bacteriophages Recovered from Beef Cattle Feedlots in South Texas.

PubMed

Xie, Yicheng; Savell, Jeffrey W; Arnold, Ashley N; Gehring, Kerri B; Gill, Jason J; Taylor, T Matthew

2016-08-01

Asymptomatic Salmonella carriage in beef cattle is a food safety concern, and the beef feedlot environment may function as a reservoir of this pathogen. The goal of this study was to identify and isolate Salmonella and Salmonella bacteriophages from beef cattle feedlot environments in order to better understand the microbial ecology of Salmonella and identify phages that might be useful as anti-Salmonella beef safety interventions. Three feedlots in south Texas were visited, and 27 distinct samples from each source were collected from dropped feces, feed from feed bunks, drinking water from troughs, and soil in cattle pens (n = 108 samples). Preenrichment, selective enrichment, and selective/differential isolation of Salmonella were performed on each sample. A representative subset of presumptive Salmonella isolates was prepared for biochemical identification and serotyping. Samples were pooled by feedlot and sample type to create 36 samples and enriched to recover phages. Recovered phages were tested for host range against two panels of Salmonella hosts. Salmonella bacteria were identified in 20 (18.5%) of 108 samples by biochemical and/or serological testing. The serovars recovered included Salmonella enterica serovars Anatum, Muenchen, Altona, Kralingen, Kentucky, and Montevideo; Salmonella Anatum was the most frequently recovered serotype. Phage-positive samples were distributed evenly over the three feedlots, suggesting that phage prevalence is not strongly correlated with the presence of culturable Salmonella. Phages were found more frequently in soil and feces than in feed and water samples. The recovery of bacteriophages in the Salmonella-free feedlot suggests that phages might play a role in suppressing the Salmonella population in a feedlot environment.

Prevalence of Salmonella in Australian reptiles.

PubMed

Scheelings, T Franciscus; Lightfoot, Dianne; Holz, Peter

2011-01-01

From January 2007 until June 2008, 504 reptiles of four families and 57 species were examined for Salmonella by using cloacal or intestinal swabs. Salmonella was identified in 139 (28%) of the 504 animals tested. Of the 504 reptiles examined, 210 were captive and 294 were wild. Ninety-eight (47%) of the captive reptiles were shedding Salmonella at the time of sampling. In contrast, only 41 (14%) of the wild reptiles were shedding Salmonella. The higher prevalence of Salmonella in captive reptiles was statistically significant (P<0.0001). No Salmonella was found in 60 wild, freshwater chelonians or 48 wild southern water skinks (Eulamprus heatwolei). Our results suggest that some species of wild reptiles in Australia are not natural carriers of Salmonella and that diet and captivity may influence Salmonella excretion in other species.

Oral immunisation of laying hens with the live vaccine strains of TAD Salmonella vac E and TAD Salmonella vac T reduces internal egg contamination with Salmonella Enteritidis.

PubMed

Gantois, Inne; Ducatelle, Richard; Timbermont, Leen; Boyen, Filip; Bohez, Lotte; Haesebrouck, Freddy; Pasmans, Frank; van Immerseel, Filip

2006-09-11

Eggs are a major source of human infections with Salmonella. Therefore controlling egg contamination in laying hen flocks is one of the main targets for control programmes. A study was carried out to assess the effect of oral vaccination with TAD Salmonella vac E, TAD Salmonella vac T and with both vaccines TAD Salmonella vac E and TAD Salmonella vac T, on colonization of the reproductive tract and internal egg contamination of laying hens with Salmonella Enteritidis. Three groups of 30 laying hens were vaccinated at 1 day, 6 weeks and 16 weeks of age with either one of the vaccine strains, or a combination of both vaccine strains, while a fourth group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 0.5 ml containing 5 x 10(7)cfu Salmonella Enteritidis PT4 S1400/94. The number of oviducts from which Salmonella was isolated, was significantly lower in the vaccinated than in the non-vaccinated hens at 3 weeks post-challenge. Significantly less egg contents were Salmonella positive in the birds vaccinated with TAD Salmonella vac E or TAD Salmonella vac T (12/105 batches of eggs in both groups) than in the unvaccinated birds (28/105 batches of eggs). Internal egg contamination in the hens vaccinated with both TAD Salmonella vac E and TAD Salmonella vac T was even more reduced, as over the whole experiment, only one batch of eggs was positive. In conclusion, these data indicate that vaccination of laying hens with these live vaccines could be considered as a valuable tool in controlling internal egg contamination.

Emergence and serovar profiling of non-typhoidal Salmonellae (NTS) isolated from gastroenteritis cases-A study from South India.

PubMed

Ballal, Mamatha; Devadas, Suganthi Martena; Shetty, Vignesh; Bangera, Sohan Rodney; Ramamurthy, Thandavarayan; Sarkar, Anirban

2016-01-01

Human infection with non-typhoidal Salmonella (NTS) serovars is often a neglected and undiagnosed infection in the developing world. Invasive NTS is now being established as having a new and emerging pathogenic role. There is not sufficient data on the prevalence of NTS serovars and their antibiotic susceptibility pattern from India. Faecal specimens collected from patients with acute gastroenteritis were processed to isolate Salmonella according to the standard protocol for a period from January 2011-December 2014. Salmonella isolates were serotyped and tested for antibiotic susceptibility. Of the total 320 (10.04%) bacterial enteric pathogens isolated, 64 (20%) were non-typhoidal Salmonella. Among the serogroup, O:4 (B) (n = 26; 40.6%) was found to be the commonest followed by O:7 (C1) (n = 11; 17.1%) and O:3,10 (E1) (n = 11; 17.1%). NTS infection in cancer patients could also be termed as nosocomial NTS diarrhoea due to primary community infection with prolonged incubation periods, consumption of contaminated food during hospital stay or Nosocomially acquired infection. Serovar Oslo has been predominant (9/17) in NTS isolates from cancer patients, whereas serovars Bovismorbificans, Wangata and Schleissheim have been reported for the first time in the country. The isolates were mostly susceptible to antibiotics except Salmonella ser Kentucky, which showed resistance to ciprofloxacin is reported for the first time in the country. Continuous surveillance is required to monitor resistance of NTS isolates.

Broad-range (pan) Salmonella and Salmonella serotype typhi-specific real-time PCR assays: potential tools for the clinical microbiologist.

PubMed

Farrell, John J; Doyle, Laura J; Addison, Rachel M; Reller, L Barth; Hall, Geraldine S; Procop, Gary W

2005-03-01

We describe broad-range salmonellae (ie, Salmonella) and Salmonella serotype Typhi-specific LightCycler (Roche Diagnostics, Indianapolis, IN) real-time polymerase chain reaction assays. We validated these with a battery of 280 bacteria, 108 of which were salmonellae representing 20 serotypes. In addition, 298 isolates from 170 clinical specimens that were suspected to possibly represent Salmonella were tested with the pan- Salmonella assay. Finally, the pan-Salmonella assay also was used to test DNA extracts from 101 archived, frozen stool specimens, 55 of which were culture-positive for salmonellae. Both assays were 100% sensitive and specific when cultured isolates of the battery were tested. The pan- Salmonella assay also characterized correctly all salmonellae on the primary isolation agar and was 96% sensitive (53/55) and 96% specific (49/51) when nucleic acid extracts from direct stool specimens were tested. These assays represent potential tools the clinical microbiologist could use to screen suspect isolates or stool specimens for Salmonella.

Pathogenesis of Salmonellosis: Salmonella Exotoxins

DTIC Science & Technology

1982-03-08

Newport; Sal. 9633 - serotype Newport; and Sal. 9186 - serotype Newport. Salmonella enteritidis serotype typhimurium strain 2000 was obtained from...7054 Table 1I CULTURE MEDIA SURVEY Salmonella enteritidis Salmonella typhimurium serotype Javiana #10016 SRlI Culture Media C H 0 Cell Factor C H 0 Cell...C r AD REPORT NUMBER 2 0 Pathogenesis of Salmonellosis: Salmonella Exotoxins Annual Progress Report (9/1/78-9/1/79) Johnny W. Peterson, Ph.D. March 8

Salmonella, including antibiotic-resistant Salmonella, from flies captured from cattle farms in Georgia, U.S.A.

PubMed

Xu, Yumin; Tao, Sha; Hinkle, Nancy; Harrison, Mark; Chen, Jinru

2018-03-01

Flies can be transmission vehicles of Salmonella from cattle to humans. This study determined the prevalence of Salmonella in/on flies captured from 33 cattle farms, including 5 beef and 28 dairy farms, in Georgia, USA, and characterized antibiotic resistance profiles of the isolated Salmonella. Twenty-six out of the 33 cattle farms (79%) and 185 out of the 1650 flies (11%) tested positive for Salmonella in the study. The incidence of Salmonella-positive flies varied from farm to farm, ranging from 0 to 78%. Among the 185 Salmonella isolated from flies, 29% were resistant to ampicillin, 28% to tetracycline, 21% to amoxicillin/clavulanic acid, 20% to cefoxitin, and 12% to streptomycin. Incidences of resistance against other tested antibiotics were low, ranging from 0 to 3%. Furthermore, 28% of the Salmonella isolates were multidrug resistant, demonstrating resistance to 3 or more antibiotics. The minimal inhibitory concentrations of ampicillin, cefoxitin, streptomycin, and tetracycline against the Salmonella isolates ranged from 32 to >2048, 64 to 2048, 128 to 1024, and 32 to 1024μg/mL, respectively. These data suggest that flies could be effective vehicles of transmitting antibiotic resistant Salmonella and disseminating antibiotic resistance genes on cattle farms, posing risks to human and animal health. Copyright © 2017 Elsevier B.V. All rights reserved.

Surveillance of Salmonella prevalence in animal feeds and characterization of the Salmonella isolates by serotyping and antimicrobial susceptibility.

PubMed

Li, X; Bethune, L A; Jia, Y; Lovell, R A; Proescholdt, T A; Benz, S A; Schell, T C; Kaplan, G; McChesney, D G

2012-08-01

This article presents the surveillance data from the Feed Contaminants Program (2002-2009) and Salmonella Assignment (2007-2009) of the U.S. Food and Drug Administration (FDA), which monitor the trend of Salmonella contamination in animal feeds. A total of 2,058 samples were collected from complete animal feeds, feed ingredients, pet foods, pet treats, and supplements for pets in 2002-2009. These samples were tested for the presence of Salmonella. Those that were positive for Salmonella underwent serotyping and testing for antimicrobial susceptibility. Of the 2,058 samples, 257 were positive for Salmonella (12.5%). The results indicate a significant overall Salmonella reduction (p≤0.05) in animal feeds from 18.2% (187 samples tested) in 2002 to 8.0% (584 samples tested) in 2009. Among these samples, feed ingredients and pet foods/treats had the most significant reduction (p≤0.05). Of the 45 Salmonella serotypes identified, Salmonella Senftenberg and Salmonella Montevideo were the top two common serotypes (8.9%). Of the 257 Salmonella isolates obtained, 54 isolates (21%) were resistant to at least one antimicrobial. The findings provide the animal feed industries with Salmonella prevalence information that can be used to address Salmonella contamination problems. Our findings can also be used to educate pet owners when handling pet foods and treats at home to prevent salmonellosis.

Antibiotic resistance determinants and genetic analysis of Salmonella enterica isolated from food in Morocco.

PubMed

Murgia, Manuela; Bouchrif, Brahim; Timinouni, Mohammed; Al-Qahtani, Ahmed; Al-Ahdal, Mohammed N; Cappuccinelli, Pietro; Rubino, Salvatore; Paglietti, Bianca

2015-12-23

Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Loop-Mediated Isothermal Amplification of the sefA Gene for Rapid Detection of Salmonella Enteritidis and Salmonella Gallinarum in Chickens.

PubMed

Gong, Jiansen; Zhuang, Linlin; Zhu, Chunhong; Shi, Shourong; Zhang, Di; Zhang, Linji; Yu, Yan; Dou, Xinhong; Xu, Bu; Wang, Chengming

2016-04-01

Salmonella spp. pose a threat to both human and animal health, with more than 2600 serovars having been reported to date. Salmonella serovars are usually identified by slide agglutination tests, which are labor intensive and time consuming. In an attempt to develop a more rapid screening method for the major poultry Salmonella serovars, we developed a loop-mediated isothermal amplification (LAMP) assay, which directly detected the sefA gene, a fimbrial operon gene existing in several specific serovars of Salmonella enterica including the major poultry serovars, namely Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) and Salmonella enterica serovar Gallinarum (Salmonella Gallinarum). With the 177 bacterial strains we tested, positive reactions were only observed with 85 strains of serovar Salmonella Enteritidis and Salmonella Gallinarum. The detection limit of the LAMP assay was 4 CFU/reaction with genomic DNAs of Salmonella Enteritidis (ATCC 13076) from pure culture and 400 CFU/ reaction with DNA extracted from spiked chicken feces. The LAMP assay was more sensitive than conventional culture, especially without enrichment, in detecting Salmonella Enteritidis (CMCC 50041) in the spiked fecal samples. The results show the sefA LAMP method is a rapid, sensitive, specific, and practical method for directly detection of Salmonella Enteritidis and Salmonella Gallinarum in chickens. The sefA LAMP assay can potentially serve as new on-site diagnostics in the poultry industry.

Recent Trends in Salmonella Outbreaks and Emerging Technology for Biocontrol of Salmonella Using Phages in Foods: A Review.

PubMed

Oh, Jun-Hyun; Park, Mi-Kyung

2017-12-28

Salmonella is one of the principal causes of foodborne outbreaks. As traditional control methods have shown less efficacy against emerging Salmonella serotypes or antimicrobialresistant Salmonella , new approaches have been attempted. The use of lytic phages for the biocontrol of Salmonella in the food industry has become an attractive method owing to the many advantages offered by the use of phages as biocontrol agents. Phages are natural alternatives to traditional antimicrobial agents; they have proven effective in the control of bacterial pathogens in the food industry, which has led to the development of different phage products. The treatment with specific phages in the food industry can prevent the decay of products and the spread of bacterial diseases, and ultimately promotes safe environments for animal and plant food production, processing, and handling. After an extensive investigation of the current literature, this review focuses predominantly on the efficacy of phages for the successful control of Salmonella spp. in foods. This review also addresses the current knowledge on the pathogenic characteristics of Salmonella , the prevalence of emerging Salmonella outbreaks, the isolation and characterization of Salmonella -specific phages, the effectiveness of Salmonella -specific phages as biocontrol agents, and the prospective use of Salmonella -specific phages in the food industry.

Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens

PubMed Central

Pei, Yanlong; Parreira, Valeria R.; Roland, Kenneth L.; Curtiss, Roy; Prescott, John F.

2014-01-01

Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors. PMID:24396177

Assessment of attenuated Salmonella vaccine strains in controlling experimental Salmonella Typhimurium infection in chickens.

PubMed

Pei, Yanlong; Parreira, Valeria R; Roland, Kenneth L; Curtiss, Roy; Prescott, John F

2014-01-01

Salmonella hold considerable promise as vaccine delivery vectors for heterologous antigens in chickens. Such vaccines have the potential additional benefit of also controlling Salmonella infection in immunized birds. As a way of selecting attenuated strains with optimal immunogenic potential as antigen delivery vectors, this study screened 20 novel Salmonella Typhimurium vaccine strains, differing in mutations associated with delayed antigen synthesis and delayed attenuation, for their efficacy in controlling colonization by virulent Salmonella Typhimurium, as well as for their persistence in the intestine and the spleen. Marked differences were observed between strains in these characteristics, which provide the basis for selection for further study as vaccine vectors.

PREVALENCE OF SALMONELLA IN CAPTIVE REPTILES FROM CROATIA.

PubMed

Lukac, Maja; Pedersen, Karl; Prukner-Radovcic, Estella

2015-06-01

Salmonellosis transmitted by pet reptiles is an increasing public health issue worldwide. The aim of this study was to investigate the prevalence of Salmonella strains from captive reptiles in Croatia. From November 2009 to November 2011 a total of 292 skin, pharyngeal, cloacal, and fecal samples from 200 apparently healthy reptiles were tested for Salmonella excretions by bacteriologic culture and serotyping. These 200 individual reptiles included 31 lizards, 79 chelonians, and 90 snakes belonging to private owners or housed at the Zagreb Zoo, Croatia. Salmonella was detected in a total of 13% of the animals, among them 48.4% lizards, 8.9% snakes, and 3.8% turtles. Representatives of five of the six Salmonella enterica subspecies were identified with the following proportions in the total number of isolates: Salmonella enterica enterica 34.6%, Salmonella enterica houtenae 23.1%, Salmonella enterica arizonae 23.1%, Salmonella enterica diarizonae 15.4%, and Salmonella enterica salamae 3.8%. The 14 different serovars isolated included several rarely occurring serovars such as Salmonella Apapa, Salmonella Halle, Salmonella Kisarawe, and Salmonella Potengi. These findings confirm that the prevalence of Salmonella is considerable in captive reptiles in Croatia, indicating that these animals may harbor serovars not commonly seen in veterinary or human microbiologic practice. This should be addressed in the prevention and diagnostics of human reptile-transmitted infections.

Genetic relatedness of a rarely isolated Salmonella: Salmonella enterica serotype Niakhar from NARMS animal isolates.

PubMed

Tankson, J D; Fedorka-Cray, P J; Jackson, C R; Headrick, M

2006-02-01

In the United States, Salmonella enterica serotype Niakhar is infrequently isolated. Between 1997 and 2000, the animal arm of the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS) assayed a total of 22,383 Salmonella isolates from various animal sources (swine, cattle, chickens, turkeys, cats, horses, exotics and dogs) for antimicrobial susceptibility. Isolates originated from diagnostic and non-diagnostic submissions. To study the phenotypic and genotypic characteristics of Salmonella Niakhar. Only five (0.02%) of the 22,383 isolates were identified as Salmonella Niakhar. Antimicrobial resistance testing indicated that three isolates were pan-susceptible, one isolate was resistant to ampicillin and one isolate was resistant to ampicillin, chloramphenicol, ciprofloxacin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline and trimethoprim/sulfamethoxazole. RAPD-PCR analysis, PFGE and ribotyping indicated that two pan-susceptible isolates were genetically similar, whereas the three remaining isolates were genetically different. The one Salmonella Niakhar isolate that was multiresistant harboured a class I integron, intI1 and two large plasmids. This study represents the first report of a ciprofloxacin-resistant Salmonella isolate from the animal arm of NARMS.

Farm-level associations with the shedding of Salmonella and antimicrobial-resistant Salmonella in U.S. dairy cattle.

PubMed

Habing, Greg G; Lombard, Jason E; Kopral, Christine A; Dargatz, David A; Kaneene, John B

2012-09-01

Salmonella enterica is the leading cause of foodborne-related deaths and hospitalizations within the United States. Infections caused by antimicrobial-resistant (AMR) strains are associated with higher hospital costs and case fatality. The objective for this study was to determine the association of management practices with the recovery of Salmonella and AMR Salmonella on dairy herds. Individual adult cow fecal samples and/or composite fecal samples were collected from 265 dairy herds in 17 states. Samples were cultured for Salmonella, and the MIC was determined for 15 antimicrobials. Herds were classified as Salmonella positive if at least one isolate was recovered, and AMR Salmonella positive if at least one resistant isolate was recovered. Questionnaires regarding management practices were administered to herd operators, and a subset of practices was selected based on subject knowledge and prior research. Data on preventive and therapeutic antimicrobial usage were included in the analysis. Logistic regression models were used to determine which practices were significantly (p<0.05) associated with each herd classification. A total of 124 and 25 herds were classified as Salmonella positive and AMR Salmonella positive, respectively. Variables significantly associated with Salmonella-positive herds included using sprinklers or misters for heat abatement (OR=2.8; CI: 1.6-4.9), feeding anionic salts to cows (OR=1.9; CI: 1.1-3.5), and feeding ionophores to cows (OR=2.1; CI: 1.2-3.7). Herds that used a broadcast/solid spread had lower odds (OR=0.26; CI: 0.11-0.63) of being Salmonella positive. Herds with at least one resistant isolate were more likely to have used composted/dried manure for bedding relative to herds with only susceptible isolates (OR=3.6; CI: 1.2-11.0). These results can be useful to focus additional research aimed at decreasing the prevalence of Salmonella and AMR Salmonella on U.S. dairy herds.

CRISPR Typing and Antibiotic Resistance Correlates with Polyphyletic Distribution in Human Isolates of Salmonella Kentucky.

PubMed

Vosik, Dorothy; Tewari, Deepanker; Dettinger, Lisa; M'ikanatha, Nkuchia M; Shariat, Nikki W

2018-02-01

Although infrequently associated with reported salmonellosis in humans, Salmonella enterica, subsp. enterica serovar Kentucky (ser. Kentucky) is the most common nonclinical, nonhuman serovar reported in the United States. The goal of this study was to use Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-multi-virulence-locus sequence typing (MVLST) to subtype a collection of human clinical isolates of ser. Kentucky submitted to the Pennsylvania Department of Health and to determine the extent of antibiotic resistance in these strains. This analysis highlighted the polyphyletic nature of ser. Kentucky, and separated our isolates into two groups, Group I and Group II, which were equally represented in our collection. Furthermore, antimicrobial susceptibility testing on all isolates using a National Antimicrobial Resistance Monitoring System (NARMS) panel of antibiotics demonstrated that resistance profiles could be divided into two groups. Group I isolates were resistant to cephems and penicillins, whereas Group II isolates were resistant to quinolones, gentamicin, and sulfisoxazole. Collectively, 50% of isolates were resistant to three or more classes of antibiotics and 30% were resistant to five or more classes. The correlation of antibiotic resistance with the two different lineages may reflect adaptation within two distinct reservoirs of ser. Kentucky, with differential exposure to antimicrobials.

Detection of Salmonellae in the Environment

PubMed Central

Thomason, Berenice M.; Biddle, James W.; Cherry, William B.

1975-01-01

The incidence of salmonellae in contrasting environments was compared in this study. Samples collected from or near surface waters in a lush hardwood forest yielded four salmonellae serotypes from six culturally positive samples. A total of 76 samples collected from the top of a granite outcropping over a 3-month period yielded 10 positive samples. Only two salmonellae serotypes were isolated, and one of these was isolated only once. The nature of the sample material had no significant effect on the detection of salmonellae from the two sampling sites. However, the presence or absence of visible moisture in the sample significantly affected the recovery of salmonellae. The results showed that even a harsh environment such as that found on top of Stone Mountain may serve as an ecological niche for the survival and transmission of salmonellae. PMID:1106319

Salmonella Infections - Multiple Languages

MedlinePlus

... Are Here: Home → Multiple Languages → All Health Topics → Salmonella Infections URL of this page: https://medlineplus.gov/ ... V W XYZ List of All Topics All Salmonella Infections - Multiple Languages To use the sharing features ...

Fecal shedding of Salmonella in exotic felids.

PubMed

Clyde, V L; Ramsay, E C; Bemis, D A

1997-06-01

Two collections of exotic felids were screened for the presence of Salmonella by selective fecal culture utilizing selenite broth and Hektoen enteric agar. In > 90% of the samples, Salmonella was isolated from a single culture. A commercial horsemeat-based diet was fed in both collections, and one collection also was fed raw chicken. Salmonella was cultured from the raw chicken and the horsemeat diet for both collections. Multiple Salmonella serotypes were identified, with S. typhimurium and S. typhimurium (copenhagen) isolated most frequently. Approximately half of the Salmonella isolates demonstrated multiple antibiotic resistance. The ability to harbor Salmonella as normal nonpathogenic bacteria of the gastrointestinal tract may be a physiological adaptation to carnivory. The high rate of fecal shedding of Salmonella in healthy individuals clouds the interpretation of a positive fecal culture in an ill felid, or one with diarrhea. All zoo employees having contact with cat feces or raw diets have a high rate of occupational exposure to Salmonella and should exercise appropriate hygienic precautions.

Survival of Salmonella Newport in oysters.

PubMed

Morrison, Christopher M; Armstrong, Alexandra E; Evans, Sanford; Mild, Rita M; Langdon, Christopher J; Joens, Lynn A

2011-08-02

Salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the United States and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. A 2005 epidemiological study done in our laboratory by Brands et al., showed that oysters in the United States are contaminated with Salmonella, and in particular, a specific strain of the Newport serovar. This work sought to further investigate the host-microbe interactions between Salmonella Newport and oysters. A procedure was developed to reliably and repeatedly expose oysters to enteric bacteria and quantify the subsequent levels of bacterial survival. The results show that 10 days after an exposure to Salmonella Newport, an average concentration of 3.7 × 10(3)CFU/g remains within the oyster meat, and even after 60 days there still can be more than 10(2)CFU/g remaining. However, the strain of Newport that predominated in the market survey done by Brands et al. does not survive within oysters or the estuarine environment better than any other strains of Salmonella we tested. Using this same methodology, we compared Salmonella Newport's ability to survive within oysters to a non-pathogenic strain of E. coli and found that after 10 days the concentration of Salmonella was 200-times greater than that of E. coli. We also compared those same strains of Salmonella and E. coli in a depuration process to determine if a constant 120 L/h flux of clean seawater could significantly reduce the concentration of bacteria within oysters and found that after 3 days the oysters retained over 10(4)CFU/g of Salmonella while the oysters exposed to the non-pathogenic strain of E. coli contained 100-times less bacteria. Overall, the results of this study demonstrate that any of the clinically relevant serovars of Salmonella can survive within oysters for significant periods of time after just one exposure event. Based on the drastic differences in survivability between Salmonella and a non

Fate of Salmonella enterica in a mixed ingredient salad containing lettuce, cheddar cheese, and cooked chicken meat.

PubMed

Bovo, Federica; De Cesare, Alessandra; Manfreda, Gerardo; Bach, Susan; Delaquis, Pascal

2015-03-01

Food service and retail sectors offer consumers a variety of mixed ingredient salads that contain fresh-cut vegetables and other ingredients such as fruits, nuts, cereals, dairy products, cooked seafood, cooked meat, cured meats, or dairy products obtained from external suppliers. Little is known about the behavior of enteric bacterial pathogens in mixed ingredient salads. A model system was developed to examine the fate of Salmonella enterica (inoculum consisting of S. enterica serovars Agona, Typhimurium, Enteritidis, Brandenberg, and Kentucky) on the surface of romaine lettuce tissues incubated alone and in direct contact with Cheddar cheese or cooked chicken. S. enterica survived but did not grow on lettuce tissues incubated alone or in contact with Cheddar cheese for 6 days at either 6 or 14°C. In contrast, populations increased from 2.01 ± 0.22 to 9.26 ± 0.22 CFU/cm(2) when lettuce washed in water was incubated in contact with cooked chicken at 14°C. Populations on lettuce leaves were reduced to 1.28 ± 0.14 CFU/cm(2) by washing with a chlorine solution (70 ppm of free chlorine) but increased to 8.45 ± 0.22 CFU/cm(2) after 6 days at 14°C. Experimentation with a commercial product in which one third of the fresh-cut romaine lettuce was replaced with inoculated lettuce revealed that S. enterica populations increased by 4 log CFU/g during storage for 3 days at 14°C. These findings indicate that rapid growth of bacterial enteric pathogens may occur in mixed ingredient salads; therefore, strict temperature control during the manufacture, distribution, handling, and storage of these products is critical.

Older leaves of lettuce (Lactuca spp.) support higher levels of Salmonella enterica ser. Senftenberg attachment and show greater variation between plant accessions than do younger leaves.

PubMed

Hunter, Paul J; Shaw, Robert K; Berger, Cedric N; Frankel, Gad; Pink, David; Hand, Paul

2015-06-01

Salmonella can bind to the leaves of salad crops including lettuce and survive for commercially relevant periods. Previous studies have shown that younger leaves are more susceptible to colonization than older leaves and that colonization levels are dependent on both the bacterial serovar and the lettuce cultivar. In this study, we investigated the ability of two Lactuca sativa cultivars (Saladin and Iceberg) and an accession of wild lettuce (L. serriola) to support attachment of Salmonella enterica serovar Senftenberg, to the first and fifth to sixth true leaves and the associations between cultivar-dependent variation in plant leaf surface characteristics and bacterial attachment. Attachment levels were higher on older leaves than on the younger ones and these differences were associated with leaf vein and stomatal densities, leaf surface hydrophobicity and leaf surface soluble protein concentrations. Vein density and leaf surface hydrophobicity were also associated with cultivar-specific differences in Salmonella attachment, although the latter was only observed in the older leaves and was also associated with level of epicuticular wax. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Performance of the chromID Salmonella Elite chromogenic agar in comparison with CHROMagar™ Salmonella, Oxoid™ Brilliance™ Salmonella and Hektoen agars for the isolation of Salmonella from stool specimens.

PubMed

Martiny, Delphine; Dediste, Anne; Anglade, Claire; Vlaes, Linda; Moens, Catherine; Mohamed, Souad; Vandenberg, Olivier

2016-10-01

chromID™ Salmonella Elite is compared with 3 culture media commonly used for Salmonella isolation from stool specimens. As results were equivalent to other chromogenic media (100% sensitivity, 98% specificity), only financial arguments should guide the choice for a medium with respect to another. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of VIDAS Salmonella (SLM) easy Salmonella method for the detection of Salmonella in a variety of foods: collaborative study.

PubMed

Crowley, Erin; Bird, Patrick; Fisher, Kiel; Goetz, Katherine; Benzinger, M Joseph; Agin, James; Goins, David; Johnson, Ronald L

2011-01-01

The VIDAS Salmonella (SLM) Easy Salmonella method is a specific enzyme-linked fluorescent immunoassay performed in the automated VIDAS instrument. The VIDAS Easy Salmonella method is a simple 2-step enrichment procedure, using pre-enrichment followed by selective enrichment in a newly formulated broth, SX2 broth. This new method was compared in a multilaboratory collaborative study to the U.S. Food and Drug Administration's Bacteriological Analytical Manual, Chapter 5 method for five food matrixes (liquid egg, vanilla ice cream, spinach, raw shrimp, and peanut butter) and the U.S. Department of Agriculture's Microbiology Laboratory Guidebook 4.04 method for deli turkey. Each food type was artificially contaminated with Salmonella at three inoculation levels. A total of 15 laboratories representing government, academia, and industry, throughout the United States, participated. In this study, 1583 samples were analyzed, of which 792 were paired replicates and 791 were unpaired replicates. Of the 792 paired replicates, 285 were positive by both the VIDAS and reference methods. Of the 791 unpaired replicates, 341 were positive by the VIDAS method and 325 were positive by the cultural reference method. A Chi-square analysis of each of the six food types was performed at the three inoculation levels tested. For all foods evaluated, the VIDAS Easy SLM method demonstrated results comparable to those of the reference methods for the detection of Salmonella.

Vaccines against invasive Salmonella disease

PubMed Central

MacLennan, Calman A; Martin, Laura B; Micoli, Francesca

2014-01-01

Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field. PMID:24804797

Characterizing Salmonella Contamination in Two Rendering Processing Plants.

PubMed

Gong, Chao; Jiang, Xiuping

2017-02-01

A microbiological investigation on Salmonella contamination was conducted in two U.S. rendering plants to investigate the potential cross-contamination of Salmonella in the rendering processing environment. Sampling locations were predetermined at the areas where Salmonella contamination may potentially occur, including raw materials receiving, crax (rendered materials before grinding process) grinding, and finished meal loading-out areas. Salmonella was either enumerated directly on xylose lysine Tergitol 4 agar plates or enriched in Rappaport-Vassiliadis and tetrathionate broths. The presumptive Salmonella isolates were confirmed using CHROMagar plating and latex agglutination testing and then characterized using pulsed-field gel electrophoresis, serotyping, and biofilm-forming determination. Among 108 samples analyzed, 79 (73%) samples were Salmonella positive after enrichment. Selected Salmonella isolates (n = 65) were assigned to 31 unique pulsed-field gel electrophoresis patterns, with 16 Salmonella serotypes, including Typhimurium and Mbandaka, identified as predominant serotypes and 10 Salmonella strains determined as strong biofilm formers. Our results indicated that the raw materials receiving area was the primary source of Salmonella and that the surfaces surrounding crax grinding and finished meal loading-out areas harbor Salmonella in biofilms that may recontaminate the finished meals. The same Salmonella serotypes found in both raw materials receiving and the finished meal loading-out areas suggested a potential of cross-contamination between different areas in the rendering processing environment.

Pathogenesis of Salmonellosis: Salmonella Exotoxins

DTIC Science & Technology

1982-03-08

of Salmonella enteritidis , which included 9630 serotype newport, 9136 serotype newport, 10016 serotype javiana, and 8832, serotype javiana were also...supplied by Dr. T. Huber. Additionally, four clinical isolates of Salmonella enteritidis , which included 986 serotype typhimurium, 2000 serotype...77Z7I AD _ REPORT NUMBER 3 0 Pathogenesis of Salmonellosis: Salmonella Exotoxins Annual Progress Report (9/1/79-8/31/80) M Johnny W. Peterson, Ph.D

Pathogenesis of Salmonellosis: Salmonella Exotoxins

DTIC Science & Technology

1982-03-08

membrane-as3ociated enterotowin produced by S. enteritidis and by S. typhimurium ; however they could find no similarities between their Salmonella ...AD. . 0 REPORT NUJMBER 1 Pathogenesis of Salmoneiliosis: Salmonella Exotoxins Annual Progress Report (12/1/77-9/1/78) Johnny W. Peterson. Ph.D. March...TYPE OF REPORT & PERIOD COVEREOD",- Uathogenesis of ,Salmonellosils: Salmonella Annual Progress Report Exotoxins 12/T/77 9/1/78 C. PERFORMCNG ORG

Impact of litter salmonella status during feed withdrawal on salmonella recovery from the broiler crop and ceca

USDA-ARS?s Scientific Manuscript database

Research was conducted to evaluate the impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the crop and ceca following feed withdrawal. In 4 experiments, pens of broilers in separate rooms were challenged with marker strains of either Salmonella Montevideo or Salmon...

Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) for detection of Salmonella on selected environmental surfaces.

PubMed

Olstein, Alan; Griffith, Leena; Feirtag, Joellen; Pearson, Nicole

2013-01-01

The Paradigm Diagnostics Salmonella Indicator Broth (PDX-SIB) is intended as a single-step selective enrichment indicator broth to be used as a simple screening test for the presence of Salmonella spp. in environmental samples. This method permits the end user to avoid multistep sample processing to identify presumptively positive samples, as exemplified by standard U.S. reference methods. PDX-SIB permits the outgrowth of Salmonella while inhibiting the growth of competitive Gram-negative and -positive microflora. Growth of Salmonella-positive cultures results in a visual color change of the medium from purple to yellow when the sample is grown at 37 +/- 1 degree C. Performance of PDX-SIB has been evaluated in five different categories: inclusivity-exclusivity, methods comparison, ruggedness, lot-to-lot variability, and shelf stability. The inclusivity panel included 100 different Salmonella serovars, 98 of which were SIB-positive during the 30 to 48 h incubation period. The exclusivity panel included 33 different non-Salmonella microorganisms, 31 of which were SIB-negative during the incubation period. Methods comparison studies included four different surfaces: S. Newport on plastic, S. Anatum on sealed concrete, S. Abaetetuba on ceramic tile, and S. Typhimurium in the presence of 1 log excess of Citrobacter freundii. Results of the methods comparison studies demonstrated no statistical difference between the SIB method and the U.S. Food and Drug Administration-Bacteriological Analytical Manual reference method, as measured by the Mantel-Haenszel Chi-square test. Ruggedness studies demonstrated little variation in test results when SIB incubation temperatures were varied over a 34-40 degrees C range. Lot-to-lot consistency results suggest no detectable differences in manufactured goods using two reference Salmonella serovars and one non-Salmonella microorganism.

Meta-analysis of chicken--salmonella infection experiments.

PubMed

Te Pas, Marinus F W; Hulsegge, Ina; Schokker, Dirkjan; Smits, Mari A; Fife, Mark; Zoorob, Rima; Endale, Marie-Laure; Rebel, Johanna M J

2012-04-24

Chicken meat and eggs can be a source of human zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing clinical signs of illness. Many investigations including genomic studies have examined the mechanisms how chickens react to infection. Apart from the innate immune response, many physiological mechanisms and pathways are reported to be involved in the chicken host response to Salmonella infection. The objective of this study was to perform a meta-analysis of diverse experiments to identify general and host specific mechanisms to the Salmonella challenge. Diverse chicken lines differing in susceptibility to Salmonella infection were challenged with different Salmonella serovars at several time points. Various tissues were sampled at different time points post-infection, and resulting host transcriptional differences investigated using different microarray platforms. The meta-analysis was performed with the R-package metaMA to create lists of differentially regulated genes. These gene lists showed many similarities for different chicken breeds and tissues, and also for different Salmonella serovars measured at different times post infection. Functional biological analysis of these differentially expressed gene lists revealed several common mechanisms for the chicken host response to Salmonella infection. The meta-analysis-specific genes (i.e. genes found differentially expressed only in the meta-analysis) confirmed and expanded the biological functional mechanisms. The meta-analysis combination of heterogeneous expression profiling data provided useful insights into the common metabolic pathways and functions of different chicken lines infected with different Salmonella serovars.

78 FR 42526 - Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-D-0254] Salmonella Contamination of Dry Dog Food; Withdrawal of Compliance Policy Guide AGENCY: Food and Drug... entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food (CPG 690.700)'' on October 1, 1980. CPG...

Autophagy Facilitates Salmonella Replication in HeLa Cells

PubMed Central

Yu, Hong B.; Croxen, Matthew A.; Marchiando, Amanda M.; Ferreira, Rosana B. R.; Cadwell, Ken; Foster, Leonard J.; Finlay, B. Brett

2014-01-01

ABSTRACT Autophagy is a process whereby a double-membrane structure (autophagosome) engulfs unnecessary cytosolic proteins, organelles, and invading pathogens and delivers them to the lysosome for degradation. We examined the fate of cytosolic Salmonella targeted by autophagy and found that autophagy-targeted Salmonella present in the cytosol of HeLa cells correlates with intracellular bacterial replication. Real-time analyses revealed that a subset of cytosolic Salmonella extensively associates with autophagy components p62 and/or LC3 and replicates quickly, whereas intravacuolar Salmonella shows no or very limited association with p62 or LC3 and replicates much more slowly. Replication of cytosolic Salmonella in HeLa cells is significantly decreased when autophagy components are depleted. Eventually, hyperreplication of cytosolic Salmonella potentiates cell detachment, facilitating the dissemination of Salmonella to neighboring cells. We propose that Salmonella benefits from autophagy for its cytosolic replication in HeLa cells. PMID:24618251

In vitro studies of chicken egg yolk antibody (IgY) against Salmonella enteritidis and Salmonella typhimurium.

PubMed

Lee, E N; Sunwoo, H H; Menninen, K; Sim, J S

2002-05-01

Chicken egg yolk antibody (IgY) raised against Salmonella enteritidis or Salmonella typhimurium was found in highly specific activity levels by ELISA. S. enteritidis- and S. typhimurium-specific IgY powder, prepared by freeze-drying the egg yolk water-soluble fraction, contained 15.5 and 10.0% of specific IgY, respectively. Anti-S. enteritidis IgY cross-reacted 55.3% with S. typhimurium. The cross-reactivity of anti-S. typhimurium IgY with S. enteritidis was 42.4%. Salmonella-specific IgY was demonstrated to inhibit Salmonella growth in liquid medium. The growth rate of S. enteritidis incubated with S. enteritidis-specific IgY was fourfold less than that of the control group during a 4-to-6-h incubation. Cell counts of S. typhimurium incubated with S. typhimurium-specific IgY were reduced by 1.6 log cfu/mL in comparison to that of the control group after 6 h of incubation. The specific binding activity of IgY was further evaluated by using immunofluorescence and immunoelectron microscopy. It was found that Salmonella-specific IgY could bind to the antigens expressed on the Salmonella surface, resulting in structural alterations of the bacterial surface.

Effects of Climate Change on Salmonella Infections

PubMed Central

Akil, Luma; Reddy, Remata S.

2014-01-01

Abstract Background: Climate change and global warming have been reported to increase spread of foodborne pathogens. To understand these effects on Salmonella infections, modeling approaches such as regression analysis and neural network (NN) were used. Methods: Monthly data for Salmonella outbreaks in Mississippi (MS), Tennessee (TN), and Alabama (AL) were analyzed from 2002 to 2011 using analysis of variance and time series analysis. Meteorological data were collected and the correlation with salmonellosis was examined using regression analysis and NN. Results: A seasonal trend in Salmonella infections was observed (p<0.001). Strong positive correlation was found between high temperature and Salmonella infections in MS and for the combined states (MS, TN, AL) models (R2=0.554; R2=0.415, respectively). NN models showed a strong effect of rise in temperature on the Salmonella outbreaks. In this study, an increase of 1°F was shown to result in four cases increase of Salmonella in MS. However, no correlation between monthly average precipitation rate and Salmonella infections was observed. Conclusion: There is consistent evidence that gastrointestinal infection with bacterial pathogens is positively correlated with ambient temperature, as warmer temperatures enable more rapid replication. Warming trends in the United States and specifically in the southern states may increase rates of Salmonella infections. PMID:25496072

Effects of climate change on Salmonella infections.

PubMed

Akil, Luma; Ahmad, H Anwar; Reddy, Remata S

2014-12-01

Climate change and global warming have been reported to increase spread of foodborne pathogens. To understand these effects on Salmonella infections, modeling approaches such as regression analysis and neural network (NN) were used. Monthly data for Salmonella outbreaks in Mississippi (MS), Tennessee (TN), and Alabama (AL) were analyzed from 2002 to 2011 using analysis of variance and time series analysis. Meteorological data were collected and the correlation with salmonellosis was examined using regression analysis and NN. A seasonal trend in Salmonella infections was observed (p<0.001). Strong positive correlation was found between high temperature and Salmonella infections in MS and for the combined states (MS, TN, AL) models (R(2)=0.554; R(2)=0.415, respectively). NN models showed a strong effect of rise in temperature on the Salmonella outbreaks. In this study, an increase of 1°F was shown to result in four cases increase of Salmonella in MS. However, no correlation between monthly average precipitation rate and Salmonella infections was observed. There is consistent evidence that gastrointestinal infection with bacterial pathogens is positively correlated with ambient temperature, as warmer temperatures enable more rapid replication. Warming trends in the United States and specifically in the southern states may increase rates of Salmonella infections.

Surveillance for human Salmonella infections in the United States.

PubMed

Swaminathan, Bala; Barrett, Timothy J; Fields, Patricia

2006-01-01

Surveillance for human Salmonella infections plays a critical role in understanding and controlling foodborne illness due to Salmonella. Along with its public health partners, the Centers for Disease Control and Prevention (CDC) has several surveillance systems that collect information on Salmonella infections in the United States. The National Salmonella Surveillance System, begun in 1962, receives reports of laboratory-confirmed Salmonella infections through state public health laboratories. Salmonella outbreaks are reported by state and local health departments through the Foodborne Disease Outbreak Reporting System, which became a Web-based, electronic system (eFORS) in 2001. PulseNet facilitates the detection of clusters of Salmonella infections through standardized molecular subtyping (DNA "fingerprinting") of isolates and maintenance of "fingerprint" databases. The National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) monitors antimicrobial resistance in Salmonella by susceptibility testing of every 20th Salmonella isolate received by state and local public health laboratories. FootNet is an active surveillance system that monitors Salmonella infections in sentinel areas, providing population-based estimates of infection rates. Efforts are underway to electronically link all of the Salmonella surveillance systems at CDC to facilitate optimum use of available data and minimize duplication.

Testing Feeds for Salmonella.

USDA-ARS?s Scientific Manuscript database

Human salmonellosis outbreaks have been linked to contamination of animal feeds. Thus it is crucial to employ sensitive Salmonella detection methods for animal feeds. Based on a review of the literature, Salmonella sustains acid injury at about pH 4.0 to5.0. Low pH can also alter the metabolism of S...

Salmonella-secreted Virulence Factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heffron, Fred; Niemann, George; Yoon, Hyunjin

In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellentmore » reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.« less

Assessment of Salmonella survival in dry-cured Italian salami.

PubMed

Bonardi, S; Bruini, I; Bolzoni, L; Cozzolino, P; Pierantoni, M; Brindani, F; Bellotti, P; Renzi, M; Pongolini, S

2017-12-04

The inactivation of Salmonella during curing of Italian traditional pork salami was investigated. A total of 150 batches of ground raw meat (GRM) used for salami manufacturing by four producers were tested for Salmonella by real-time PCR followed by ISO 6579 cultural confirmation and MPN enumeration. Salami produced with Salmonella positive GRMs were re-tested at the end of their curing period. Aw, pH and NaCl content were also measured. Detection of Salmonella was performed testing both 25 and 50g of the samples. By Real-Time PCR 37% of the GRMs resulted positive, but cultural detection of Salmonella was obtained in 14% of the samples only. Salmonella enumeration ranged from 31 MPN/g to <1.3 MPN/g. The difference between testing 50g and 25g of the samples was statistically significant (p value≤0.01). In particular, ISO-50g detected Salmonella in 100% of all positive samples, vs. 62% of ISO-25g. Salami made of the contaminated GRMs were 29% Salmonella-positive, as most batches of salami produced with Salmonella-positive GRMs resulted negative after regular curing (20-48days). Overall, 13% of salami produced with Salmonella-contaminated GRMs were positive. They belonged to six batches, which turned out negative after prolonged curing ranging between 49 and 86days. Salmonella enumeration in salami ranged from 8.7 MPN/g to <1.3 MPN/g. Unlike GRMs, no significant difference was observed between the ISO-50g and the ISO-25g in detecting Salmonella in cured salami (p value: >0.05). The most common Salmonella serovars in GRMs were Derby (52%), Typhimurium monophasic variant 4, (Barbuti et al., 1993), 12:i:- (19%) and Stanley (10%). Salmonella Derby (56%), London, Branderup, Panama (13%, respectively) and Goldcoast (6%) were most frequent in cured salami. The study showed negative correlation between real-time CT values and cultural confirmation of Salmonella, as well as the importance of sample size for Salmonella detection. Among considered factors with possible effect

Comparison of CHROMagar Salmonella Medium and Hektoen Enteric Agar for Isolation of Salmonellae from Stool Samples

PubMed Central

Gaillot, Olivier; Di Camillo, Patrick; Berche, Patrick; Courcol, René; Savage, Colette

1999-01-01

CHROMagar Salmonella (CAS), a new chromogenic medium, was retrospectively compared to Hektoen enteric agar (HEA) with 501 Salmonella stock isolates and was then prospectively compared to HEA for the detection and presumptive identification of Salmonella spp. with 508 stool samples before and after enrichment. All stock cultures (100%), including cultures of H2S-negative isolates, yielded typical mauve colonies on CAS, while 497 (99%) isolates produced typical lactose-negative, black-centered colonies on HEA. Following overnight incubation at 37°C, a total of 20 Salmonella strains were isolated from the 508 clinical samples. Sensitivities for primary plating and after enrichment were 95% (19 isolates) and 100% (20 isolates), respectively, for CAS and 80% (16 isolates) and 100% (20 isolates), respectively, for HEA. The specificity of CAS (88.9%) was significantly higher than that of HEA (78.5%; P < 0.0001). On the basis of its good sensitivity and specificity, CAS medium can be recommended for use for primary plating when human stool samples are screened for Salmonella spp. PMID:9986847

Review on SERS of Bacteria

PubMed Central

Mosier-Boss, Pamela A.

2017-01-01

Surface enhanced Raman spectroscopy (SERS) has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data. PMID:29137201

A single-tube screen for Salmonella and Shigella.

PubMed

Procop, Gary W; Wallace, Jacqueline D; Tuohy, Marion J; Lasalvia, Margret M; Addison, Rachel M; Reller, L Barth

2008-08-01

Salmonella and Shigella species are routinely sought in stool specimens submitted for culture. It is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and Christensen urea agar to determine if further identification is necessary. We designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent Salmonella or Shigella. We tested this media combination with 106 Salmonella, 56 Shigella, and 56 other gram-negative bacilli. All Salmonella and Shigella isolates tested were appropriately characterized as possible Salmonella or Shigella by using an algorithm developed for use with this media combination. Similarly, 53 (95%) of 56 other gram-negative bacilli were appropriately screened as non -Salmonella and non -Shigella isolates. This unique media combination provides the most important biochemical reactions needed to screen for Salmonella and Shigella in a single-tube format, which decreases labor by two thirds (ie, 1 tube is inoculated vs 3).

Meta-analysis of Chicken – Salmonella infection experiments

PubMed Central

2012-01-01

Background Chicken meat and eggs can be a source of human zoonotic pathogens, especially Salmonella species. These food items contain a potential hazard for humans. Chickens lines differ in susceptibility for Salmonella and can harbor Salmonella pathogens without showing clinical signs of illness. Many investigations including genomic studies have examined the mechanisms how chickens react to infection. Apart from the innate immune response, many physiological mechanisms and pathways are reported to be involved in the chicken host response to Salmonella infection. The objective of this study was to perform a meta-analysis of diverse experiments to identify general and host specific mechanisms to the Salmonella challenge. Results Diverse chicken lines differing in susceptibility to Salmonella infection were challenged with different Salmonella serovars at several time points. Various tissues were sampled at different time points post-infection, and resulting host transcriptional differences investigated using different microarray platforms. The meta-analysis was performed with the R-package metaMA to create lists of differentially regulated genes. These gene lists showed many similarities for different chicken breeds and tissues, and also for different Salmonella serovars measured at different times post infection. Functional biological analysis of these differentially expressed gene lists revealed several common mechanisms for the chicken host response to Salmonella infection. The meta-analysis-specific genes (i.e. genes found differentially expressed only in the meta-analysis) confirmed and expanded the biological functional mechanisms. Conclusions The meta-analysis combination of heterogeneous expression profiling data provided useful insights into the common metabolic pathways and functions of different chicken lines infected with different Salmonella serovars. PMID:22531008

Investigation of an outbreak of Salmonella enteritidis gastroenteritis associated with consumption of eggs in a restaurant chain in Maryland.

PubMed

Lin, F Y; Morris, J G; Trump, D; Tilghman, D; Wood, P K; Jackman, N; Israel, E; Libonati, J P

1988-10-01

Salmonella enteritidis ser. enteritidis was isolated from patrons and employees of three restaurants in a restaurant chain in Maryland during August and September 1985. Isolates from all three restaurants had identical plasmid profiles; this profile was present in 13 of 40 randomly selected S. enteritidis isolates received by the Maryland state health department laboratory during a comparable time period. The outbreak in one restaurant resulted in at least 71 illnesses, with 17 persons known to have been hospitalized. Scrambled eggs served on a "breakfast bar" were implicated as the vehicle of transmission in this restaurant, with eggs a possible vehicle in another of the three restaurants. The data point out the risks associated with improper handling of eggs in food service establishments, provide further evidence for the observed association between S. enteritidis and eggs in the northeastern United States, and demonstrate the utility of plasmid analysis in investigation of outbreaks involving common Salmonella serotypes.

Salmonella: an ecological success story

USDA-ARS?s Scientific Manuscript database

Salmonella was first described in 1885 as a secondary pathogen in the infectious disease process. In 1929, a paper published in the Proceedings of the Royal Society of Medicine reported that Salmonella organisms were predominant in food borne outbreaks but acknowledged that the path of infection wa...

Development of multiplex PCR assay for simultaneous detection of Salmonella genus, Salmonella subspecies I, Salm. Enteritidis, Salm. Heidelberg and Salm. Typhimurium.

PubMed

Park, S H; Ricke, S C

2015-01-01

The aim of this research was to develop multiplex PCR assay that could simultaneously detect Salmonella genus, Salmonella subsp. I, Salm. Enteritidis, Heidelberg and Typhimurium because these Salmonella serovars are the most common isolates associated with poultry products. Five primers were utilized to establish multiplex PCR and applied to Salmonella isolates from chickens and farm environments. These isolates were identified as Salmonella subsp. I and 16 of 66 isolates were classified as Salm. Enteritidis, while Heidelberg or Typhimurium was not detected. We also spiked three Salmonella strains on chicken breast meat to evaluate the specificity and sensitivity of multiplex PCR as well as qPCR to optimize quantification of Salmonella in these samples. The optimized multiplex PCR and qPCR could detect approx. 2·2 CFU of Salmonella per gram after 18 h enrichment. The multiplex PCR and qPCR would provide rapid and consistent results. Also, these techniques would be useful for the detection and quantification of Salmonella in contaminated poultry, foods and environmental samples. The strategy for the rapid detection of Salmonella serovars in poultry is needed to further reduce the incidence of salmonellosis in humans. The optimized multiplex PCR will be useful to detect prevalent Salmonella serovars in poultry products. © 2014 The Society for Applied Microbiology.

Salmonella Levels Associated with Skin of Turkey Parts.

PubMed

Peng, Ye; Deng, Xiang Y; Harrison, Mark A; Alali, Walid Q

2016-05-01

Turkey skin is used as a source of fat in finished ground turkey products. Salmonella-contaminated skin may potentially disseminate this pathogen to ground turkey. The objective of this study was to determine and compare Salmonella levels (presence and numbers) associated with the skin of turkey parts (i.e., drumstick, thigh, and wing). Over a 10-month period, 20 turkey flocks expected to be highly contaminated with Salmonella based on boot-sock testing data of turkey houses were sampled. A total of 300 samples per type of turkey part were collected postchill and were tested for Salmonella using the most-probable-number (MPN) and enrichment methods. Overall, Salmonella was detected in 13.7, 19.7, and 25.0% of drumstick skin, thigh skin, and wing skin samples, respectively. Salmonella prevalence from wing skin was significantly higher (P < 0.05) than in drumstick skin, but the difference was not significant (P > 0.05) when compared with thigh skin. Salmonella was 2.4 times more likely to be present from thigh skin (odds ratio = 2.4; P < 0.05) when the pathogen was found from wing skin. Salmonella mean numbers from drumstick, thigh, and wing were 1.18, 1.29, and 1.45 log MPN per sample, respectively; these values were not significantly different (P > 0.05). Based on our findings, the high prevalence of Salmonella associated with the skin of turkey parts could be a potential source for ground turkey contamination.

Salmonella serotype distribution in the Dutch broiler supply chain.

PubMed

van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J

2009-12-01

Salmonella serotype distribution can give insight in contamination routes and persistence along a production chain. Therefore, it is important to determine not only Salmonella prevalence but also to specify the serotypes involved at the different stages of the supply chain. For this purpose, data from a national monitoring program in the Netherlands were used to estimate the serotype distribution and to determine whether this distribution differs for the available sampling points in the broiler supply chain. Data covered the period from 2002 to 2005, all slaughterhouses (n = 22), and the following 6 sampling points: departure from hatchery, arrival at the farm, departure from the farm, arrival at the slaughterhouse, departure from the slaughterhouse, and end of processing. Furthermore, retail data for 2005 were used for comparison with slaughterhouse data. The following serotypes were followed throughout the chain: Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Paratyphi B var. Java (Salmonella Java), Salmonella Infantis, Salmonella Virchow, and Salmonella Mbandaka. Results showed that serotype distribution varied significantly throughout the supply chain (P < 0.05). Main differences were found at the farm and at the slaughterhouse (within one stage), and least differences were found between departure from one stage and arrival at the next stage. The most prominent result was the increase of Salmonella Java at farm level. This serotype remained the most prominent pathogen throughout the broiler supply chain up to the retail phase.

Sources of salmonellae in an uninfected commercially-processed broiler flock.

PubMed

Rigby, C E; Pettit, J R; Baker, M F; Bentley, A H; Salomons, M O; Lior, H

1980-07-01

Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae were isolated from any of 132 litter samples of 189 chickens cultured during the seven-week growing period, even though nest litter samples from four of the eight parent flocks yielded salmonellae and Salmonella worthington was isolated from the meat meal component of the grower ration. On arrival at the plant, 2/23 birds sampled carried S. infantis on their feathers, although intestinal cultures failed to yield salmonellae. Three of 18 processed carcasses samples yielded salmonellae (S. infantis, S. heidelberg, S. typhimurium var copenhagen). The most likely source of these salmonellae was the plastic transport crates, since 15/107 sampled before the birds were loaded yielded salmonellae (S. infantis, S. typhimurium). The crate washer at the plant did not reduce the incidence of Salmonella-contaminated crates, since 16/116 sampled after washing yielded salmonellae (S. infantis, S. typhimurium, S. heidelberg, S. schwarzengrund, S. albany).

Salmonella: A century old conundrum

USDA-ARS?s Scientific Manuscript database

In 1885 a new bacterial species, Salmonella cholerae suis which was thought to cause hog cholera. Interestingly, Salmonella cholerae suis was not the etiologic agent of hog cholera (which is caused by a virus), but it was observed to be a secondary pathogen in the infectious process. In 1929, a pa...

Survival of Salmonella during baking of peanut butter cookies.

PubMed

Lathrop, Amanda A; Taylor, Tiffany; Schnepf, James

2014-04-01

Peanuts and peanut-based products have been the source of recent Salmonella outbreaks worldwide. Because peanut butter is commonly used as an ingredient in baked goods, such as cookies, the potential risk of Salmonella remaining in these products after baking needs to be assessed. This research examines the potential hazard of Salmonella in peanut butter cookies when it is introduced via the peanut-derived ingredient. The survival of Salmonella during the baking of peanut butter cookies was determined. Commercial, creamy-style peanut butter was artificially inoculated with a five-strain Salmonella cocktail at a target concentration of 10(8) CFU/g. The inoculated peanut butter was then used to prepare peanut butter cookie dough following a standard recipe. Cookies were baked at 350 °F (177 °C) and were sampled after 10, 11, 12, 13, 14, and 15 min. Temperature profiles of the oven and cookies were monitored during baking. The water activity and pH of the inoculated and uninoculated peanut butter, raw dough, and baked cookies were measured. Immediately after baking, cookies were cooled, and the survival of Salmonella was determined by direct plating or enrichment. After baking cookies for 10 min, the minimum reduction of Salmonella observed was 4.8 log. In cookies baked for 13 and 14 min, Salmonella was only detectable by enrichment reflecting a Salmonella reduction in the range of 5.2 to 6.2 log. Cookies baked for 15 min had no detectable Salmonella. Results of this study showed that proper baking will reduce Salmonella in peanut butter cookies by 5 log or more.

Dysregulated humoral immunity to nontyphoidal Salmonella in HIV-infected African adults

PubMed Central

MacLennan, Calman A.; Gilchrist, James J.; Gordon, Melita A.; Cunningham, Adam F.; Cobbold, Mark; Goodall, Margaret; Kingsley, Robert A.; van Oosterhout, Joep J. G.; Msefula, Chisomo L.; Mandala, Wilson L.; Leyton, Denisse L.; Marshall, Jennifer L.; Gondwe, Esther N.; Bobat, Saeeda; López-Macías, Constantino; Doffinger, Rainer; Henderson, Ian R.; Zijlstra, Eduard E.; Dougan, Gordon; Drayson, Mark T.; MacLennan, Ian C. M.; Molyneux, Malcolm E.

2013-01-01

Nontyphoidal Salmonellae are a major cause of life-threatening bacteremia among HIV-infected individuals. Although cell-mediated immunity controls intracellular infection, antibody protects against Salmonella bacteremia. We report that high titer antibodies specific for Salmonella lipopolysaccharide (LPS) associate with absent Salmonella-killing in HIV-infected African adults. Killing was restored by genetically shortening LPS from target Salmonella, or removing LPS-specific antibodies from serum. Complement-mediated killing of Salmonella by healthy serum is shown to be induced specifically by antibodies against outer membrane proteins. This killing is lost when excess antibody against Salmonella LPS is added. Thus our study indicates impaired immunity against nontyphoidal Salmonella bacteremia in HIV infection results from excess inhibitory antibodies against Salmonella LPS, whilst serum killing of Salmonella is induced by antibodies against outer membrane proteins. PMID:20413503

Salmonella induces prominent gene expression in the rat colon

PubMed Central

Rodenburg, Wendy; Keijer, Jaap; Kramer, Evelien; Roosing, Susanne; Vink, Carolien; Katan, Martijn B; van der Meer, Roelof; Bovee-Oudenhoven, Ingeborg MJ

2007-01-01

Background Salmonella enteritidis is suggested to translocate in the small intestine. In vivo it induces gene expression changes in the ileal mucosa and Peyer's patches. Stimulation of Salmonella translocation by dietary prebiotics fermented in colon suggests involvement of the colon as well. However, effects of Salmonella on colonic gene expression in vivo are largely unknown. We aimed to characterize time dependent Salmonella-induced changes of colonic mucosal gene expression in rats using whole genome microarrays. For this, rats were orally infected with Salmonella enteritidis to mimic a foodborne infection and colonic gene expression was determined at days 1, 3 and 6 post-infection (n = 8 rats per time-point). As fructo-oligosaccharides (FOS) affect colonic physiology, we analyzed colonic mucosal gene expression of FOS-fed versus cellulose-fed rats infected with Salmonella in a separate experiment. Colonic mucosal samples were isolated at day 2 post-infection. Results Salmonella affected transport (e.g. Chloride channel calcium activated 6, H+/K+ transporting Atp-ase), antimicrobial defense (e.g. Lipopolysaccharide binding protein, Defensin 5 and phospholipase A2), inflammation (e.g. calprotectin), oxidative stress related genes (e.g. Dual oxidase 2 and Glutathione peroxidase 2) and Proteolysis (e.g. Ubiquitin D and Proteosome subunit beta type 9). Furthermore, Salmonella translocation increased serum IFNγ and many interferon-related genes in colonic mucosa. The gene most strongly induced by Salmonella infection was Pancreatitis Associated Protein (Pap), showing >100-fold induction at day 6 after oral infection. Results were confirmed by Q-PCR in individual rats. Stimulation of Salmonella translocation by dietary FOS was accompanied by enhancement of the Salmonella-induced mucosal processes, not by induction of other processes. Conclusion We conclude that the colon is a target tissue for Salmonella, considering the abundant changes in mucosal gene expression

Salmonella induces prominent gene expression in the rat colon.

PubMed

Rodenburg, Wendy; Keijer, Jaap; Kramer, Evelien; Roosing, Susanne; Vink, Carolien; Katan, Martijn B; van der Meer, Roelof; Bovee-Oudenhoven, Ingeborg M J

2007-09-12

Salmonella enteritidis is suggested to translocate in the small intestine. In vivo it induces gene expression changes in the ileal mucosa and Peyer's patches. Stimulation of Salmonella translocation by dietary prebiotics fermented in colon suggests involvement of the colon as well. However, effects of Salmonella on colonic gene expression in vivo are largely unknown. We aimed to characterize time dependent Salmonella-induced changes of colonic mucosal gene expression in rats using whole genome microarrays. For this, rats were orally infected with Salmonella enteritidis to mimic a foodborne infection and colonic gene expression was determined at days 1, 3 and 6 post-infection (n = 8 rats per time-point). As fructo-oligosaccharides (FOS) affect colonic physiology, we analyzed colonic mucosal gene expression of FOS-fed versus cellulose-fed rats infected with Salmonella in a separate experiment. Colonic mucosal samples were isolated at day 2 post-infection. Salmonella affected transport (e.g. Chloride channel calcium activated 6, H+/K+ transporting Atp-ase), antimicrobial defense (e.g. Lipopolysaccharide binding protein, Defensin 5 and phospholipase A2), inflammation (e.g. calprotectin), oxidative stress related genes (e.g. Dual oxidase 2 and Glutathione peroxidase 2) and Proteolysis (e.g. Ubiquitin D and Proteosome subunit beta type 9). Furthermore, Salmonella translocation increased serum IFN gamma and many interferon-related genes in colonic mucosa. The gene most strongly induced by Salmonella infection was Pancreatitis Associated Protein (Pap), showing >100-fold induction at day 6 after oral infection. Results were confirmed by Q-PCR in individual rats. Stimulation of Salmonella translocation by dietary FOS was accompanied by enhancement of the Salmonella-induced mucosal processes, not by induction of other processes. We conclude that the colon is a target tissue for Salmonella, considering the abundant changes in mucosal gene expression.

Isolation of Salmonella enterica serovar Enteritidis from houseflies (Musca domestica) found in rooms containing Salmonella serovar Enteritidis-challenged hens.

PubMed

Holt, Peter S; Geden, Christopher J; Moore, Randle W; Gast, Richard K

2007-10-01

Houseflies (Musca domestica) released into rooms containing hens challenged with Salmonella enterica serovar Enteritidis (Salmonella serovar Enteritidis) rapidly became contaminated with Salmonella serovar Enteritidis. Forty to 50% of the flies were contaminated at 48 h, and the percentage increased to 50 to 70% at 4 and 7 days postexposure and then decreased to 30% at day 15. Initial attempts at recovering surface organisms for culture using an aqueous rinse were largely unsuccessful, while cultures of internal contents readily recovered Salmonella serovar Enteritidis. However, when 0.5% detergent was incorporated into the rinse, high recovery levels of bacteria were observed from both external and internal culture regimens, indicating equal distribution of the organism on and in the fly and a tighter interaction of the organism with the host than previously thought. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never from the salivary gland. Feeding contaminated flies to hens resulted in gut colonization of a third of the birds, but release of contaminated flies in a room containing previously unchallenged hens failed to result in colonization of any of the subject birds. These results indicate that flies exposed to an environment containing Salmonella serovar Enteritidis can become colonized with the organism and might serve as a source for transmission of Salmonella serovar Enteritidis within a flock situation.

Isolation of Salmonella enterica Serovar Enteritidis from Houseflies (Musca domestica) Found in Rooms Containing Salmonella Serovar Enteritidis-Challenged Hens▿

PubMed Central

Holt, Peter S.; Geden, Christopher J.; Moore, Randle W.; Gast, Richard K.

2007-01-01

Houseflies (Musca domestica) released into rooms containing hens challenged with Salmonella enterica serovar Enteritidis (Salmonella serovar Enteritidis) rapidly became contaminated with Salmonella serovar Enteritidis. Forty to 50% of the flies were contaminated at 48 h, and the percentage increased to 50 to 70% at 4 and 7 days postexposure and then decreased to 30% at day 15. Initial attempts at recovering surface organisms for culture using an aqueous rinse were largely unsuccessful, while cultures of internal contents readily recovered Salmonella serovar Enteritidis. However, when 0.5% detergent was incorporated into the rinse, high recovery levels of bacteria were observed from both external and internal culture regimens, indicating equal distribution of the organism on and in the fly and a tighter interaction of the organism with the host than previously thought. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never from the salivary gland. Feeding contaminated flies to hens resulted in gut colonization of a third of the birds, but release of contaminated flies in a room containing previously unchallenged hens failed to result in colonization of any of the subject birds. These results indicate that flies exposed to an environment containing Salmonella serovar Enteritidis can become colonized with the organism and might serve as a source for transmission of Salmonella serovar Enteritidis within a flock situation. PMID:17675422

The enhanced immune responses induced by Salmonella enteritidis ghosts loaded with Neisseria gonorrhoeae porB against Salmonella in mice.

PubMed

Jiao, Hongmei; Yang, Hui; Zhao, Dan; He, Li; Chen, Jin; Li, Guocai

2016-11-01

Human health has been seriously endangered by highly prevalent salmonellosis and multidrug-resistant Salmonella strains. Current vaccines suffer from variable immune-protective effects, so more effective ones are needed to control Salmonella infection : Bacterial ghosts have been produced by the expression of lysis gene E from bacteriophage PhiX174 and can be filled with considerable exogenous substances such as DNA or drugs as a novel platform. In this study, Salmonella enteritidis (SE) ghosts were developed and loaded with Neisseria gonorrhoeae porin B (porB) to construct a novel inactive vaccine. Our new studies show that SE ghosts loaded with porB displayed increased production of pro-inflammatory cytokines (IL-1β, IL-6, IL-10 and IL-12p70) in bone marrow-derived dendritic cells (BMDCs), and elicited significantly higher specific systemic and mucosal immune responses to Salmonella than SE ghosts alone. In addition, the novel porB-loaded ghosts conferred higher protective effects on virulent Salmonella challenge. For the first time, we demonstrate that N. gonorrhoeae porB, as a novel adjuvant, can increase the immunogenicity of SE ghosts. Our studies suggested that Salmonella enteritidis ghosts loaded with Neisseria gonorrhoeae porin B might be a useful mucosal Salmonella vaccine candidate for practical use in the future. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Salmonella

USDA-ARS?s Scientific Manuscript database

Salmonella are facultative anaerobic Gram-negative non-spore forming rods belonging to the family Enterobacteriaceae. Salmonellosis is a zoonotic and foodborne illness that is usually transmitted by the fecal-oral route estimated to be responsible for 1.4 million cases of human infections in 2009 in...

Thermal inactivation of Salmonella spp. in pork burger patties.

PubMed

Gurman, P M; Ross, T; Holds, G L; Jarrett, R G; Kiermeier, A

2016-02-16

Predictive models, to estimate the reduction in Escherichia coli O157:H7 concentration in beef burgers, have been developed to inform risk management decisions; no analogous model exists for Salmonella spp. in pork burgers. In this study, "Extra Lean" and "Regular" fat pork minces were inoculated with Salmonella spp. (Salmonella 4,[5],12,i:-, Salmonella Senftenberg and Salmonella Typhimurium) and formed into pork burger patties. Patties were cooked on an electric skillet (to imitate home cooking) to one of seven internal temperatures (46, 49, 52, 55, 58, 61, 64 °C) and Salmonella enumerated. A generalised linear logistic regression model was used to develop a predictive model for the Salmonella concentration based on the internal endpoint temperature. It was estimated that in pork mince with a fat content of 6.1%, Salmonella survival will be decreased by -0.2407log10 CFU/g for a 1 °C increase in internal endpoint temperature, with a 5-log10 reduction in Salmonella concentration estimated to occur when the geometric centre temperature reaches 63 °C. The fat content influenced the rate of Salmonella inactivation (P=0.043), with Salmonella survival increasing as fat content increased, though this effect became negligible as the temperature approached 62 °C. Fat content increased the time required for patties to achieve a specified internal temperature (P=0.0106 and 0.0309 for linear and quadratic terms respectively), indicating that reduced fat pork mince may reduce the risk of salmonellosis from consumption of pork burgers. Salmonella serovar did not significantly affect the model intercepts (P=0.86) or slopes (P=0.10) of the fitted logistic curve. This predictive model can be applied to estimate the reduction in Salmonella in pork burgers after cooking to a specific endpoint temperature and hence to assess food safety risk. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Chk1 phosphorylation at Ser286 and Ser301 occurs with both stalled DNA replication and damage checkpoint stimulation.

PubMed

Ikegami, Yosuke; Goto, Hidemasa; Kiyono, Tohru; Enomoto, Masato; Kasahara, Kousuke; Tomono, Yasuko; Tozawa, Keiichi; Morita, Akimichi; Kohri, Kenjiro; Inagaki, Masaki

2008-12-26

We previously reported Chk1 to be phosphorylated at Ser286 and Ser301 by cyclin-dependent kinase (Cdk) 1 during mitosis [T. Shiromizu et al., Genes Cells 11 (2006) 477-485]. Here, we demonstrated that Chk1-Ser286 and -Ser301 phosphorylation also occurs in hydroxyurea (HU)-treated or ultraviolet (UV)-irradiated cells. Unlike the mitosis case, however, Chk1 was phosphorylated not only at Ser286 and Ser301 but also at Ser317 and Ser345 in the checkpoint response. Treatment with Cdk inhibitors diminished Chk1 phosphorylation at Ser286 and Ser301 but not at Ser317 and Ser345 with the latter. In vitro analyses revealed Ser286 and Ser301 on Chk1 to serve as two major phosphorylation sites for Cdk2. Immunoprecipitation analyses further demonstrated that Ser286/Ser301 and Ser317/Ser345 phosphorylation occur in the same Chk1 molecule during the checkpoint response. In addition, Ser286/Ser301 phosphorylation by Cdk2 was observed in Chk1 mutated to Ala at Ser317 and Ser345 (S317A/S345A), as well as Ser317/Ser345 phosphorylation by ATR was in S286A/S301A. Therefore, Chk1 phosphorylation in the checkpoint response is regulated not only by ATR but also by Cdk2.

Subinhibitory concentrations of phloretin repress the virulence of Salmonella typhimurium and protect against Salmonella typhimurium infection.

PubMed

Shuai-Cheng, Wu; Ben-Dong, Fu; Xiu-Ling, Chu; Jian-Qing, Su; Yun-Xing, Fu; Zhen-Qiang, Cui; Dao-Xiu, Xu; Zong-Mei, Wu

2016-11-01

Phloretin, a natural component of many fruits, exhibits anti-virulence effects and provides a new alternative to counter bacterial infection. The aim of this study was to determine the effect of subinhibitory concentrations of phloretin on the virulence of Salmonella typhimurium. At concentrations where growth of Salmonella was not inhibited, phloretin significantly inhibited bacteria biofilm formation and motility. Subinhibitory concentrations of phloretin repressed eight genes involved in the Salmonella pathogenicity island 1 and 3 genes involved in flagella production. Furthermore, subinhibitory concentrations of phloretin inhibited the adhesion and invasion of Salmonella in IEC-6 cells and reduced the LDH levels of S. typhimurium-infected IEC-6 cells. Additionally, phloretin significantly decreased the cecum bacterial loads of the mice infected with live S. typhimurium containing subinhibitory concentrations of phloretin by gavage. These results suggested that subinhibitory concentrations of phloretin attenuate the virulence of S. typhimurium and protect against S. typhimurium infection.

Applications of microscopy in Salmonella research.

PubMed

Malt, Layla M; Perrett, Charlotte A; Humphrey, Suzanne; Jepson, Mark A

2015-01-01

Salmonella enterica is a Gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in humans and many other animals. Understanding the mechanisms by which Salmonella induces disease has been the focus of intensive research. This has revealed that Salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cellular responses initiated by proteins translocated into the host cell by a type 3 secretion system. Once these Salmonella-induced responses have resulted in bacterial invasion, proteins translocated by a second type 3 secretion system initiate further modulation of cellular activities to enable survival and replication of the invading pathogen. Elucidation of the complex and highly dynamic pathogen-host interactions ultimately requires analysis at the level of single cells and single infection events. To achieve this goal, researchers have applied a diverse range of microscopy techniques to analyze Salmonella infection in models ranging from whole animal to isolated cells and simple eukaryotic organisms. For example, electron microscopy and high-resolution light microscopy techniques such as confocal microscopy can reveal the precise location of Salmonella and its relationship to cellular components. Widefield light microscopy is a simpler approach with which to study the interaction of bacteria with host cells and often has advantages for live cell imaging, enabling detailed analysis of the dynamics of infection and cellular responses. Here we review the use of imaging techniques in Salmonella research and compare the capabilities of different classes of microscope to address specific types of research question. We also provide protocols and notes on some microscopy techniques used routinely in our own research.

Prevalence and antibiotic resistance of Salmonella Enteritidis and Salmonella Typhimurium in raw chicken meat at retail markets in Malaysia.

PubMed

Thung, T Y; Mahyudin, N A; Basri, D F; Wan Mohamed Radzi, C W J; Nakaguchi, Y; Nishibuchi, M; Radu, S

2016-08-01

Salmonellosis is one of the major food-borne diseases in many countries. This study was carried out to determine the occurrence of Salmonella spp., Salmonella Enteritidis, and Salmonella Typhimurium in raw chicken meat from wet markets and hypermarkets in Selangor, as well as to determine the antibiotic susceptibility profile of S. Enteritidis and S. Typhimurium. The most probable number (MPN) in combination with multiplex polymerase chain reaction (mPCR) method was used to quantify the Salmonella spp., S. Enteritidis, and S. Typhimurium in the samples. The occurrence of Salmonella spp., S. Enteritidis, and S. Typhimurium in 120 chicken meat samples were 20.80%, 6.70%, and 2.50%, respectively with estimated quantity varying from <3 to 15 MPN/g. The antibiogram testing revealed differential multi-drug resistance among S. Enteritidis and S. Typhimurium isolates. All the isolates were resistance to erythromycin, penicillin, and vancomycin whereas sensitivity was recorded for Amoxicillin/Clavulanic acid, Gentamicin, Tetracycline, and Trimethoprim. Our findings demonstrated that the retail chicken meat could be a source of multiple antimicrobial-resistance Salmonella and may constitute a public health concern in Malaysia. © 2016 Poultry Science Association Inc.

Isolation and characterization of Salmonella enterica in day-old ducklings in Egypt

PubMed Central

Osman, Kamelia M; Marouf, Sherif H; Zolnikov, Tara R; AlAtfeehy, Nayerah

2014-01-01

Importing day-old ducklings (DOD) unknowingly infected with non-typhoid Salmonella (NTS) may be associated with disease risk. Domestic and international trade may enhance this risk. Salmonella enterica serovars, their virulence genes combinations and antibiotic resistance, garner attention for their potentiality to contribute to the adverse health effects on populations throughout the world. The aim of this study was to estimate the risk of imported versus domestic DOD as potential carriers of NTS. The results confirm the prevalence of salmonellosis in imported ducklings was 18.5% (25/135), whereas only 12% (9/75) of cases were determined in the domestic ducklings. Fourteen serovars (Salmonella enteritidis, Salmonella kisii, Salmonella typhimurium, Salmonella gaillac, Salmonella uno, Salmonella eingedi, Salmonella shubra, Salmonella bardo, Salmonella inganda, Salmonella kentucky, Salmonella stanley, Salmonella virchow, Salmonella haifa, and Salmonella anatum) were isolated from the imported ducklings, whereas only S. enteritidis, S. typhimurium, S. virchow, and S. shubra were isolated from the domestic ducklings. The isolated Salmonella serovars were 100% susceptible to only colistin sulphate and 100% resistant to lincomycin. The 14 Salmonella serovars were screened for 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) by PCR. The invA, sopB, and bcfC genes were detected in 100% of the Salmonella serovars; alternatively, the gipA gene was absent in all of the isolated Salmonella serovars. The 11 virulent genes were not detected in either of S. stanley or S. haifa serovars. The results confirm an association between antibiotic resistance and virulence of Salmonella in the DOD. This study confirms the need for a country adherence to strict public health and food safety regimes. PMID:24548159

Antimicrobial efficiency of essential oil and freeze-thaw treatments against Escherichia coli O157:H7 and Salmonella enterica Ser. Enteritidis in strawberry juice.

PubMed

Duan, J; Zhao, Y

2009-04-01

This study investigated the antimicrobial efficiency of 3 essential oils (EOs), lemongrass, cinnamon leaf, and basil, and freeze-thaw treatment, alone or in combination, against Escherichia coli O157:H7 and Salmonella enterica Ser. Enteritidis inoculated in strawberry juice stored at 7 degrees C. EO of lemongrass or cinnamon leaf at 0.1 to 2 microL/mL and freezing at -23 degrees C for 24 or 48 h followed by thawing at 7 degrees C for 4 h all showed significant antimicrobial activities (P < 0.05) against E. coli O157:H7 and S. Enteritidis in strawberry juice. The antimicrobial activity increased with increasing EO concentration and storage time, but extending freezing time from 24 to 48 h did not enhance the antimicrobial activity of freeze-thaw treatment (P > 0.05). EO of lemongrass or cinnamon leaf at 0.1 microL/mL and freeze-thaw treatment alone obtained a 5 log(10) reduction in the population of S. Enteritidis, while EOs at 0.1 to 0.3 microL/mL or freeze-thaw alone could not achieve a satisfactory protection against E. coli O157:H7 in strawberry juice. Combined EO and freeze-thaw treatment enhanced the overall antimicrobial effect against E. coli O157:H7, with adding EO before the freeze-thaw treatment showed a faster decontamination rate than when added EO after the freeze-thaw. EOs of lemongrass and cinnamon leaf at 0.1 or 0.3 microL/mL followed by the freeze-thawing resulted in a 5 log(10) reduction in E. coli O157:H7 on the 5th and 2nd day of storage, respectively. This study suggested that combined EO and freeze-thaw treatment may be a suitable and inexpensive method to eliminate microorganisms that can be a hazard for the consumers of unpasteurized berry juices.

Reorganization of the Endosomal System in Salmonella-Infected Cells: The Ultrastructure of Salmonella-Induced Tubular Compartments

PubMed Central

Krieger, Viktoria; Liebl, David; Zhang, Yuying; Rajashekar, Roopa; Chlanda, Petr; Giesker, Katrin; Chikkaballi, Deepak; Hensel, Michael

2014-01-01

During the intracellular life of Salmonella enterica, a unique membrane-bound compartment termed Salmonella-containing vacuole, or SCV, is formed. By means of translocated effector proteins, intracellular Salmonella also induce the formation of extensive, highly dynamic membrane tubules termed Salmonella-induced filaments or SIF. Here we report the first detailed ultrastructural analyses of the SCV and SIF by electron microscopy (EM), EM tomography and live cell correlative light and electron microscopy (CLEM). We found that a subset of SIF is composed of double membranes that enclose portions of host cell cytosol and cytoskeletal filaments within its inner lumen. Despite some morphological similarities, we found that the formation of SIF double membranes is independent from autophagy and requires the function of the effector proteins SseF and SseG. The lumen of SIF network is accessible to various types of endocytosed material and our CLEM analysis of double membrane SIF demonstrated that fluid phase markers accumulate only between the inner and outer membrane of these structures, a space continual with endosomal lumen. Our work reveals how manipulation of the endosomal membrane system by an intracellular pathogen results in a unique tubular membrane compartmentalization of the host cell, generating a shielded niche permissive for intracellular proliferation of Salmonella. PMID:25254663

Myofilament Calcium Sensitivity: Mechanistic Insight into TnI Ser-23/24 and Ser-150 Phosphorylation Integration

PubMed Central

Salhi, Hussam E.; Hassel, Nathan C.; Siddiqui, Jalal K.; Brundage, Elizabeth A.; Ziolo, Mark T.; Janssen, Paul M. L.; Davis, Jonathan P.; Biesiadecki, Brandon J.

2016-01-01

Troponin I (TnI) is a major regulator of cardiac muscle contraction and relaxation. During physiological and pathological stress, TnI is differentially phosphorylated at multiple residues through different signaling pathways to match cardiac function to demand. The combination of these TnI phosphorylations can exhibit an expected or unexpected functional integration, whereby the function of two phosphorylations are different than that predicted from the combined function of each individual phosphorylation alone. We have shown that TnI Ser-23/24 and Ser-150 phosphorylation exhibit functional integration and are simultaneously increased in response to cardiac stress. In the current study, we investigated the functional integration of TnI Ser-23/24 and Ser-150 to alter cardiac contraction. We hypothesized that Ser-23/24 and Ser-150 phosphorylation each utilize distinct molecular mechanisms to alter the TnI binding affinity within the thin filament. Mathematical modeling predicts that Ser-23/24 and Ser-150 phosphorylation affect different TnI affinities within the thin filament to distinctly alter the Ca2+-binding properties of troponin. Protein binding experiments validate this assertion by demonstrating pseudo-phosphorylated Ser-150 decreases the affinity of isolated TnI for actin, whereas Ser-23/24 pseudo-phosphorylation is not different from unphosphorylated. Thus, our data supports that TnI Ser-23/24 affects TnI-TnC binding, while Ser-150 phosphorylation alters TnI-actin binding. By measuring force development in troponin-exchanged skinned myocytes, we demonstrate that the Ca2+ sensitivity of force is directly related to the amount of phosphate present on TnI. Furthermore, we demonstrate that Ser-150 pseudo-phosphorylation blunts Ser-23/24-mediated decreased Ca2+-sensitive force development whether on the same or different TnI molecule. Therefore, TnI phosphorylations can integrate across troponins along the myofilament. These data demonstrate that TnI Ser-23

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of Salmonella contamination... REQUIREMENTS Standard Procedures § 113.30 Detection of Salmonella contamination. The test for detection of Salmonella contamination provided in this section shall be conducted when such a test is prescribed in an...

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Detection of Salmonella contamination... REQUIREMENTS Standard Procedures § 113.30 Detection of Salmonella contamination. The test for detection of Salmonella contamination provided in this section shall be conducted when such a test is prescribed in an...

Evaluation of 3M molecular detection assay (MDA) Salmonella for the detection of Salmonella in selected foods: collaborative study.

PubMed

Bird, Patrick; Fisher, Kiel; Boyle, Megan; Huffman, Travis; Benzinger, M Joseph; Bedinghaus, Paige; Flannery, Jonathan; Crowley, Erin; Agin, James; Goins, David; Benesh, DeAnn; David, John

2013-01-01

The 3M Molecular Detection Assay (MDA) Salmonella is used with the 3M Molecular Detection System for the detection of Salmonella spp. in food, food-related, and environmental samples after enrichment. The assay utilizes loop-mediated isothermal amplification to rapidly amplify Salmonella target DNA with high specificity and sensitivity, combined with bioluminescence to detect the amplification. The 3M MDA Salmonella method was compared using an unpaired study design in a multilaboratory collaborative study to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG 4.05), Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products for raw ground beef and the U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference method for wet dog food following the current AOAC guidelines. A total of 20 laboratories participated. For the 3M MDA Salmonella method, raw ground beef was analyzed using 25 g test portions, and wet dog food was analyzed using 375 g test portions. For the reference methods, 25 g test portions of each matrix were analyzed. Each matrix was artificially contaminated with Salmonella at three inoculation levels: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2-2 CFU/test portion), and a high inoculum level (2-5 CFU/test portion). In this study, 1512 unpaired replicate samples were analyzed. Statistical analysis was conducted according to the probability of detection (POD). For the low-level raw ground beef test portions, the following dLPOD (difference between the POD of the reference and candidate method) values with 95% confidence intervals were obtained: -0.01 (-0.14, +0.12). For the low-level wet dog food test portions, the following dLPOD with 95% confidence intervals were obtained: -0.04 (-0.16, +0.09). No significant differences were observed in the number of positive

The major sources of Salmonella enteritidis in Thailand.

PubMed

Sakai, T; Chalermchaikit, T

1996-08-01

The data of Salmonella serotypes during 1989-1993 from the World Health Organisation (WHO) National Salmonella and Shigella Center, Division of Clinical Pathology, Department of Medical Science, Ministry of Health, Thailand was analysed and found that the prevalence of Salmonella enteritidis had been dramatically increased since 1990. The average S. enteritidis isolates from human patient samples was 0.70% +/- 0.41% of the total reported Salmonella isolates during 1972-1989 and increased to 1.33%, 2.98%, 9.54%, and 16.98% in 1990, 1991, 1992, and 1993, respectively. The similar trend of S. enteritidis isolates from chicken meat samples were also observed. However, the conclusive epidemiological relationship between human and chicken S. enteritidis isolates needs to be proved by phage typing or other Salmonella typing methods.

Comparison of Microbial Communities Isolated from Feces of Asymptomatic Salmonella-Shedding and Non-Salmonella Shedding Dairy Cows

PubMed Central

Haley, Bradd J.; Pettengill, James; Gorham, Sasha; Ottesen, Andrea; Karns, Jeffrey S.; Van Kessel, Jo Ann S.

2016-01-01

In the United States Salmonella enterica subsp. enterica serotypes Kentucky and Cerro are frequently isolated from asymptomatic dairy cows. However, factors that contribute to colonization of the bovine gut by these two serotypes have not been identified. To investigate associations between Salmonella status and bacterial diversity, as well as the diversity of the microbial community in the dairy cow hindgut, the bacterial and archaeal communities of fecal samples from cows on a single dairy farm were determined by high-throughput sequencing of 16S rRNA gene amplicons. Fecal grab samples were collected from two Salmonella-positive cows and two Salmonella-negative cows on five sampling dates (n = 20 cows), and 16S rRNA gene amplicons from these samples were sequenced on the Illumina MiSeq platform. A high level of alpha (within) and beta diversity (between) samples demonstrated that microbial profiles of dairy cow hindguts are quite diverse. To determine whether Salmonella presence, sampling year, or sampling date explained a significant amount of the variation in microbial diversity, we performed constrained ordination analyses (distance based RDA) on the unifrac distance matrix produced with QIIME. Results indicated that there was not a significant difference in the microbial diversity associated with Salmonella presence (P > 0.05), but there were significant differences between sampling dates and years (Pseudo-F = 2.157 to 4.385, P < 0.05). Based on these data, it appears that commensal Salmonella infections with serotypes Cerro and Kentucky in dairy cows have little or no association with changes in the abundance of major bacterial groups in the hindgut. Rather, our results indicated that temporal dynamics and other undescribed parameters associated with them were the most influential drivers of the differences in microbial diversity and community structure in the dairy cow hindgut. PMID:27313565

Interactions of Salmonella with animals and plants.

PubMed

Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe

2014-01-01

Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections.

Prevalence of Salmonella in diverse environmental farm samples.

PubMed

Rodriguez, Andres; Pangloli, Philipus; Richards, Harold A; Mount, John R; Draughon, F Ann

2006-11-01

The development of suitable intervention strategies to control Salmonella populations at the farm level requires reliable data on the occurrence and prevalence of the pathogen. Previous studies on Salmonella prevalence have focused on acquiring data from specific farm types and/or selected regions. The purpose of this study was to evaluate the distribution of this pathogen across a variety of farm types and regions in order to generate comparative data from a diverse group of environmental samples. Farm samples (n = 2,496) were collected quarterly from 18 different farms across five states (Tennessee, North Carolina, Alabama, California, and Washington) over a 24-month period. The participating farms included beef and dairy cattle operations, swine production and farrowing facilities, and poultry farms (both broiler chicken and turkey). The samples were analyzed for the presence of Salmonella by means of the U.S. Food and Drug Administration's Bacteriological Analytical Manual methods optimized for farm samples. Salmonella isolates were characterized by automated riboprinting. Salmonella serovars were recovered from 4.7% of all samples. The majority of positive findings were isolated from swine farms (57.3%). The occurrence of Salmonella was lower on dairy farms (17.9%), poultry farms (16.2%), and beef cattle farms (8.5%). The most commonly isolated serovar was Salmonella Anatum (48.4%), which was isolated notably more frequently than the next most common Salmonella serovars, Arizonae (12.1%) and Javiana (8.8%). The results of this study suggest that significant reservoirs of Salmonella populations still exist on swine production facilities and to a lesser extent in other animal production facilities. Data showed that the surrounding farm environment could be an important source of contamination.

Salmonella in beef and produce from honduras.

PubMed

Maradiaga, Martha; Miller, Mark F; Thompson, Leslie; Pond, Ansen; Gragg, Sara E; Echeverry, Alejandro; Garcia, Lyda G; Loneragan, Guy H; Brashears, Mindy M

2015-03-01

Salmonella continues to cause a considerable number of foodborne illnesses worldwide. The sources of outbreaks include contaminated meat and produce. The purpose of this study was to establish an initial investigation of the burden of Salmonella in produce and beef from Honduras by sampling retail markets and abattoirs. Retail produce samples (cantaloupes, cilantro, cucumbers, leafy greens, peppers, and tomatoes; n = 573) were purchased in three major cities of Honduras, and retail whole-muscle beef (n = 555) samples were also purchased in four major cities. Additionally, both hide and beef carcass (n = 141) samples were collected from two Honduran abattoirs. Whole-muscle beef samples were obtained using a sponge hydrated with buffered peptone water, and 10 ml of the buffered peptone water rinsate of each produce sample was collected with a dry sponge and placed in a bag to be transported back to the United States. Salmonella was detected using a commercially available, closeplatform PCR system, and positive samples were subjected to culture on selective media to obtain isolates. Overall, the prevalence of Salmonella-positive samples, based on PCR detection in Honduras (n = 555) retail beef was 10.1% (95% confidence interval = 7.8, 12.9), whereas 7.8% (n = 141) of beef carcass and hides samples were positive in both beef plants. The overall Salmonella prevalence for all produce samples (n = 573) collected was 2.1% (95% confidence interval = 1.2, 3.6). The most common serotypes identified in Honduras were Salmonella Typhimurium followed by Derby. These results provide an indication of Salmonella contamination of beef and produce in Honduras. Developing a Salmonella baseline for Latin America through an initial investigation like the one presented here contributes to a broader global understanding of the potential exposure through food, thus providing insight into the needs for control strategies.

Immunity to Intracellular Salmonella Depends on Surface-associated Antigens

PubMed Central

Claudi, Beatrice; Mazé, Alain; Schemmer, Anne K.; Kirchhoff, Dennis; Schmidt, Alexander; Burton, Neil; Bumann, Dirk

2012-01-01

Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens. PMID:23093937

Salmonella prevalence in bovine lymph nodes differs among feedyards.

PubMed

Haneklaus, Ashley N; Harris, Kerri B; Griffin, Davey B; Edrington, Thomas S; Lucia, Lisa M; Savell, Jeffrey W

2012-06-01

Lymphatic tissue, specifically lymph nodes, is commonly incorporated into ground beef products as a component of lean trimmings. Salmonella and other pathogenic bacteria have been identified in bovine lymph nodes, which may impact compliance with the Salmonella performance standards for ground beef established by the U.S. Department of Agriculture. Although Salmonella prevalence has been examined among lymph nodes between animals, no data are currently available regarding feedyard origin of the cattle and Salmonella prevalence. Bovine lymph nodes (279 superficial cervical plus 28 iliofemoral = 307) were collected from beef carcasses at a commercial beef harvest and processing plant over a 3-month period and examined for the prevalence of Salmonella. Cattle processed were from seven feedyards (A through G). Salmonella prevalence was exceptionally low (0% of samples were positive ) in cattle from feedyard A and high (88.2%) in cattle from feedyard B. Prevalence in the remaining feedyards ranged widely: 40.0% in feedyard C, 4.0% in feedyard D, 24.0% in feedyard E, 42.9% in feedyard F, and 40.0% in feedyard G. These data indicate the range of differences in Salmonella prevalence among feedyards. Such information may be useful for developing interventions to reduce or eliminate Salmonella from bovine lymph nodes, which would assist in the reduction of Salmonella in ground beef.

Laboratory-based Salmonella surveillance in Fiji, 2004-2005.

PubMed

Dunn, John; Pryor, Jan; Saketa, Salanieta; Delai, Wasale; Buadromo, Eka; Kishore, Kamal; Naidu, Shakila; Greene, Sharon; Varma, Jay; Chiller, Tom

2005-09-01

Although foodborne diseases are an important public health problem worldwide, the burden of foodborne illness is not well described in most Pacific Island Countries and Territories. Laboratory-based surveillance programs can detect trends and outbreaks, estimate burden of illness, and allow subtyping of enteric pathogens (e.g. Salmonella serotyping), which is critical for linking illness to food vehicles and animal reservoirs. To enhance public health capacity in Fiji for foodborne disease surveillance, we developed the Salmonella Surveillance Project (SSP), a collaboration to pilot laboratory-based surveillance for Salmonella. A network of national and international partners was formed including epidemiologists, microbiologists, and environmental health personnel. Ministry of Health personnel were trained in foodborne disease surveillance and outbreak investigation. Three clinical microbiology laboratories from different parts of the country functioned as sentinel sites, reporting all laboratory-confirmed Salmonella infections using a standardized case report form. Non-Typhi Salmonella isolates were collected for serotyping. In 2004-2005, 86 non-Typhi Salmonella and 275 S. Typhi laboratory-confirmed infections were reported. Salmonella enterica serotype I 3,10: r:- and Salmonella enterica serotype Weltevreden were the most commonly isolated non-Typhi serotypes. In Fiji, the SSP utilized international partnerships to facilitate training, and to enhance laboratory capacity and surveillance for salmonellosis. Incorporating laboratory-based foodborne disease reporting into national disease surveillance will enable public health officials to describe the burden of foodborne illness, identify outbreaks, conduct analytic epidemiology studies, and improve food safety.

Diversity of Salmonella isolates from central Florida surface waters.

PubMed

McEgan, Rachel; Chandler, Jeffrey C; Goodridge, Lawrence D; Danyluk, Michelle D

2014-11-01

Identification of Salmonella serotypes is important for understanding the environmental diversity of the genus Salmonella. This study evaluates the diversity of Salmonella isolates recovered from 165 of 202 Central Florida surface water samples and investigates whether the serotype of the environmental Salmonella isolates can be predicted by a previously published multiplex PCR assay (S. Kim, J. G. Frye, J. Hu, P. J. Fedorka-Cray, R. Gautom, and D. S. Boyle, J. Clin. Microbiol. 44:3608-3615, 2006, http://dx.doi.org/10.1128/JCM.00701-06). Multiplex PCR was performed on 562 Salmonella isolates (as many as 36 isolates per water sample) to predict serotypes. Kauffmann-White serogrouping was used to confirm multiplex PCR pattern groupings before isolates were serotyped, analyzed by pulsed-field gel electrophoresis, and assayed for antimicrobial susceptibility. In 41.2% of the Salmonella-positive water samples, all Salmonella isolates had identical multiplex PCR patterns; in the remaining 58.8%, two or more multiplex PCR patterns were identified. Within each sample, isolates with matching multiplex PCR patterns had matching serogroups. The multiplex patterns of 495 isolates (88.1%) did not match any previously reported pattern. The remaining 68 isolates matched reported patterns but did not match the serotypes for those patterns. The use of the multiplex PCR allowed the number of isolates requiring further analysis to be reduced to 223. Thirty-three Salmonella enterica serotypes were identified; the most frequent included serotypes Muenchen, Rubislaw, Anatum, Gaminara, and IV_50:z4,z23:-. A majority (141/223) of Salmonella isolates clustered into one genotypic group. Salmonella isolates in Central Florida surface waters are serotypically, genotypically, and phenotypically (in terms of antimicrobial susceptibility) diverse. While isolates could be grouped as different or potentially the same using multiplex PCR, the multiplex PCR pattern did not predict the Salmonella

Diversity of Salmonella Isolates from Central Florida Surface Waters

PubMed Central

McEgan, Rachel; Chandler, Jeffrey C.; Goodridge, Lawrence D.

2014-01-01

Identification of Salmonella serotypes is important for understanding the environmental diversity of the genus Salmonella. This study evaluates the diversity of Salmonella isolates recovered from 165 of 202 Central Florida surface water samples and investigates whether the serotype of the environmental Salmonella isolates can be predicted by a previously published multiplex PCR assay (S. Kim, J. G. Frye, J. Hu, P. J. Fedorka-Cray, R. Gautom, and D. S. Boyle, J. Clin. Microbiol. 44:3608–3615, 2006, http://dx.doi.org/10.1128/JCM.00701-06). Multiplex PCR was performed on 562 Salmonella isolates (as many as 36 isolates per water sample) to predict serotypes. Kauffmann-White serogrouping was used to confirm multiplex PCR pattern groupings before isolates were serotyped, analyzed by pulsed-field gel electrophoresis, and assayed for antimicrobial susceptibility. In 41.2% of the Salmonella-positive water samples, all Salmonella isolates had identical multiplex PCR patterns; in the remaining 58.8%, two or more multiplex PCR patterns were identified. Within each sample, isolates with matching multiplex PCR patterns had matching serogroups. The multiplex patterns of 495 isolates (88.1%) did not match any previously reported pattern. The remaining 68 isolates matched reported patterns but did not match the serotypes for those patterns. The use of the multiplex PCR allowed the number of isolates requiring further analysis to be reduced to 223. Thirty-three Salmonella enterica serotypes were identified; the most frequent included serotypes Muenchen, Rubislaw, Anatum, Gaminara, and IV_50:z4,z23:−. A majority (141/223) of Salmonella isolates clustered into one genotypic group. Salmonella isolates in Central Florida surface waters are serotypically, genotypically, and phenotypically (in terms of antimicrobial susceptibility) diverse. While isolates could be grouped as different or potentially the same using multiplex PCR, the multiplex PCR pattern did not predict the Salmonella

Salmonella Overcomes Drug Resistance in Tumor through P-glycoprotein Downregulation.

PubMed

Yang, Chih-Jen; Chang, Wen-Wei; Lin, Song-Tao; Chen, Man-Chin; Lee, Che-Hsin

2018-01-01

Chemotherapy is one of effective methods for the treatment of tumor. Patients often develop drug resistance after chemotherapic cycles. Salmonella has potential as antitumor agent. Salmonella used in tandem with chemotherapy had additive effects, providing a rationale for using tumor-targeting Salmonella in combination with conventional chemotherapy. To improve the efficacy and safety of Salmonella , a further understanding of Salmonella interactions with the tumor microenvironment is required. The presence of plasma membrane multidrug resistance protein P-glycoprotein (P-gp) is highly relevant for the success of chemotherapy. Following Salmonella infection, dose-dependent downregulation of P-gp expressions were examined. Salmonella significantly decreased the efflux capabilities of P-gp, as based on the influx of Rhodamine 123 assay. In addition, Salmonella significant reduced the protein express the expression levels of phosph-protein kinase B (P-AKT), phosph-mammalian targets of rapamycin (P-mTOR), and phosph-p70 ribosomal s6 kinase (P-p70s6K) in tumor cells. The Salmonella -induced downregulation of P-gp was rescued by transfection of cells with active P-AKT. Our results demonstrate that Salmonella in tumor sites leads to decrease the expression of P-gp and enhances the combination of Salmonell a and 5-Fluorouracil therapeutic effects.

Salmonella Infections

MedlinePlus

... reptiles like snakes, turtles, and lizards. Symptoms include Fever Diarrhea Abdominal cramps Headache Possible nausea, vomiting, and ... be serious. The usual treatment is antibiotics. Typhoid fever, a more serious disease caused by Salmonella, is ...

Salmonella Isolates in the Introduced Asian House Gecko (Hemidactylus frenatus) with Emphasis on Salmonella Weltevreden, in Two Regions in Costa Rica.

PubMed

Jiménez, Randall R; Barquero-Calvo, Elías; Abarca, Juan G; Porras, Laura P

2015-09-01

The Asian house gecko Hemidactylus frenatus has been widely introduced in Costa Rica and tends to establish in human settlements. Some studies in other invaded countries have suggested that this gecko plays a significant role in the epidemiology of salmonellosis and it is of value to public health. To our knowledge, no studies have examined Salmonella from this species in Costa Rica. Therefore, we collected 115 geckos from houses in two Costa Rican regions. We examined gut contents for Salmonella through microbiological analysis. Presumptive Salmonella spp. were sent to a reference laboratory for serotyping and antimicrobial susceptibility testing. Molecular typing was also conducted with the main Salmonella isolates of zoonotic relevance in Costa Rica. H. frenatus was found in 95% of the houses surveyed. Salmonella was isolated in 4.3% of the samples, and four zoonotic serovars were detected. None of the isolates were resistant to the antibiotics most frequently used for salmonellosis treatment in Costa Rica. All Salmonella isolates from the lower gut of H. frenatus are associated with human salmonellosis. Pulsotypes from Salmonella enterica serotype Weltevreden were identical to the only clone previously reported from human samples in Costa Rica. Molecular typing of Salmonella Weltevreden suggested that H. frenatus harbors a serovar of public health importance in Costa Rica. Results demonstrated that H. frenatus plays a role in the epidemiology of human salmonellosis in two regions of Costa Rica. However, more detailed epidemiological studies are needed to understand better the role of the Asian house gecko with human salmonellosis, especially caused by Salmonella Weltevreden, and to quantify its risk in Costa Rica accurately.

Recent Progress in SERS Biosensing

PubMed Central

Bantz, Kyle C.; Meyer, Audrey F.; Wittenberg, Nathan J.; Im, Hyungsoon; Kurtuluş, Özge; Lee, Si Hoon; Lindquist, Nathan C.

2011-01-01

This perspective gives an overview of recent developments in surface-enhanced Raman scattering (SERS) for biosensing. We focus this review on SERS papers published in the last 10 years and to specific applications of detecting biological analytes. Both intrinsic and extrinsic SERS biosensing schemes have been employed to detect and identify small molecules, nucleic acids, lipids, peptides, and proteins, as well as for in vivo and cellular sensing. Current SERS substrate technologies along with a series of advancements in surface chemistry, sample preparation, intrinsic/extrinsic signal transduction schemes, and tip-enhanced Raman spectroscopy are discussed. The progress covered herein shows great promise for widespread adoption of SERS biosensing. PMID:21509385

Prevalence of salmonella in neck skin and bone of chickens.

PubMed

Wu, Diezhang; Alali, W Q; Harrison, M A; Hofacre, C L

2014-07-01

Bone-in and boneless parts, such as drumsticks, are used in ground chicken production. In addition, neck skin is used as a source of fat in ground products. Contaminated chicken neck skin and bones containing internalized Salmonella are potential sources of this pathogen in ground chicken. This study determined the prevalence of Salmonella and serotype distribution in drumstick bones and neck skin of postchill chicken carcasses. One week prior to slaughter, chicken houses (n = 26) at nine farms were tested for the presence of Salmonella, using the boot sock method. Chicken flocks from these houses originated from Salmonella-positive breeders. Eight Salmonella-positive chicken flocks and one flock with undetermined Salmonella status were monitored through processing. Three hundred postchill drumsticks and 299 neck skin samples were analyzed for Salmonella prevalence. Skin samples were rinsed and stomached prior to analysis. Bones were extracted from the drumsticks, external surfaces were sterilized, and bones were crushed for analysis. One Salmonella isolate from each positive sample was serogrouped. Half of the isolates representing different sample types were serotyped. Overall, Salmonella was found in 0.8, 21.4, and 80.1% of bone marrow, neck skin, and farms, respectively. Prevalence of Salmonella on rinsed skin samples (2.3%) and stomached skin samples (20.7%) differed significantly (P ≤ 0.05). Serogroups B, C2, D, and E were found at 23.4, 31.9, 11.7, and 29.8%, respectively. Six Salmonella serotypes were identified: Liverpool (37.9%), Kentucky (27.6%), and Typhimurium (27.6%) were isolated most frequently from neck skin; the two bone isolates were Kentucky; and more than 50% of the farm isolates were Kentucky and Ouakam. Salmonella-contaminated neck skin might be a more significant source of this contamination in ground chicken than Salmonella internalized in bones.

Salmonella enterica Serovar Enteritidis, England and Wales, 1945–2011

PubMed Central

Lane, Christopher R.; LeBaigue, Susan; Esan, Oluwaseun B.; Awofisyo, Adedoyin A.; Adams, Natalie L.; Fisher, Ian S.T.; Grant, Kathie A.; Peters, Tansy M.; Larkin, Lesley; Davies, Robert H.

2014-01-01

In England and Wales, the emergence of Salmonella enterica serovar Enteritidis resulted in the largest and most persistent epidemic of foodborne infection attributable to a single subtype of any pathogen since systematic national microbiological surveillance was established. We reviewed 67 years of surveillance data to examine the features, underlying causes, and overall effects of S. enterica ser. Enteritidis. The epidemic was associated with the consumption of contaminated chicken meat and eggs, and a decline in the number of infections began after the adoption of vaccination and other measures in production and distribution of chicken meat and eggs. We estimate that >525,000 persons became ill during the course of the epidemic, which caused a total of 6,750,000 days of illness, 27,000 hospitalizations, and 2,000 deaths. Measures undertaken to control the epidemic have resulted in a major reduction in foodborne disease in England and Wales. PMID:24960614

Allelic variation in TLR4 is linked to resistance to Salmonella Enteritidis infection in chickens.

PubMed

Li, Peng; Wang, Huihua; Zhao, Xingwang; Gou, Zhongyong; Liu, Ranran; Song, Yongmei; Li, Qinghe; Zheng, Maiqing; Cui, Huanxian; Everaert, Nadia; Zhao, Guiping; Wen, Jie

2017-07-01

Salmonella Enteritidis (SE) is a foodborne pathogen that negatively affects both animal and human health. Polymorphisms of the TLR4 gene may affect recognition by Toll-like receptor 4 (TLR4) of bacterial lipopolysaccharide (LPS), leading to differences in host resistance to pathogenic infections. The present study has investigated polymorphic loci of chicken TLR4 (ChTLR4) in ten chicken breeds, electrostatic potentials of mutant structures of TLR4, and a linkage analysis between allelic variation and survival ratio to infection with SE in specific-pathogen-free (SPF) White Leghorns. A total of 19 Single Nucleotide Polymorphisms (SNPs), of which 10 were novel, were found in chicken breeds. Seven newly identified amino acid variants (C68G, G674A, G782A, A896T, T959G, T986A, and A1104C) and previously reported important mutations (G247A, G1028A, C1147T, and A1832G) were demonstrated in the extracellular domain of the ChTLR4 gene. Significant changes in surface electrostatic potential of the ectodomain of TLR4, built by homology modeling, were observed at the Glu83Lys (G247A), Arg298Ser (A896T), Ser368Arg (A1104C), and Gln611Arg (A1832G) substitutions. Linkage analysis showed that one polymorphic locus G247A of TLR4 gene, common in all breeds examined, was significantly associated with increased resistance to SE in SPF White Leghorns chicks (log-rank P-value = 0.04). The genotypes from A1832G SNPs did not show statistically significant survival differences. This study has provided the first direct evidence that G247A substitution in ChTLR4 is associated with increased resistance to Salmonella Enteritidis. © 2017 Poultry Science Association Inc.

Salmonella-based plague vaccines for bioterrorism.

PubMed

Calhoun, Leona Nicole; Kwon, Young-Min

2006-04-01

Yersinia pestis, the causative agent of plague, is an emerging threat as a means of bioterrorism. Accordingly, the Working Group on Civilian Biodefense, as well as the Centers for Disease Control and Prevention, has specified Y. pestis as a prime candidate for use in bioterrorism. As the threat of bioterrorism increases, so does the need for an effective vaccine against this potential agent. Experts agree that a stable, non-invasive vaccine would be necessary for the rapid large-scale immunization of a population following a bioterrorism attack. Thus far, live Salmonella-based oral vaccines show the most potential for this purpose. When delivered via a mucosal route, Salmonella-based plague vaccines show the ability to protect against the deadly pneumonic form of plague. Also, mass production, distribution, and administration are easier and less costly for attenuated Salmonella-based plague vaccines than for plague vaccines consisting of purified proteins. Most attenuated Salmonella-based plague vaccines have utilized a plasmid-based expression system to deliver plague antigen(s) to the mucosa. However, these systems are frequently associated with plasmid instability, an increased metabolic burden upon the vaccine strain, and highly undesirable antibiotic resistance genes. The future of Salmonella-based plague vaccines seems to lie in the use of chromosomally encoded plague antigens and the use of in vivo inducible promoters to drive their expression. This method of vaccine development has been proven to greatly increase the retention of foreign genes, and also eliminates the need for antibiotic resistance genes within Salmonella-based vaccines.

Transcriptomic analysis of Salmonella desiccation resistance.

PubMed

Li, Haiping; Bhaskara, Anuhya; Megalis, Christina; Tortorello, Mary Lou

2012-12-01

The survival of Salmonella in low moisture foods and processing environments remains a great challenge for the food industry and public health. To explore the mechanisms of Salmonella desiccation resistance, we studied the transcriptomic responses in Salmonella Tennessee (Tennessee), using Salmonella Typhimurium LT2 (LT2), a strain weakly resistant to desiccation, as a reference strain. In response to 2 h of air-drying at 11% equilibrated relative humidity, approximately one-fourth of the open reading frames (ORFs) in the Tennessee genome and one-fifth in LT2 were differentially expressed (>2-fold). Among all differentially expressed functional groups (>5-fold) in both strains, the expression fold change associated with fatty acid metabolism was the highest, and constituted 51% and 35% of the total expression fold change in Tennessee and LT2, respectively. Tennessee showed greater changes in expression of genes associated with stress response and envelope modification than LT2, while showing lesser changes in protein biosynthesis expression. Expression of flagella genes was significantly more inhibited in stationary phase cells of Tennessee than LT2 both before and after desiccation. The accumulation of the osmolyte trehalose was significantly induced by desiccation in Tennessee, but no increase was detectable in LT2, which is consistent with the expression patterns of the entire trehalose biosynthesis and degradation pathways in both strains. Results from this study present a global view of the dynamic desiccation responses in Salmonella, which will guide future research efforts to control Salmonella in low moisture environments.

Photochemical Decoration of Silver Nanocrystals on Magnetic MnFe2O4 Nanoparticles and Their Applications in Antibacterial Agents and SERS-Based Detection

NASA Astrophysics Data System (ADS)

Huy, Le Thanh; Tam, Le Thi; Van Son, Tran; Cuong, Nguyen Duy; Nam, Man Hoai; Vinh, Le Khanh; Huy, Tran Quang; Ngo, Duc-The; Phan, Vu Ngoc; Le, Anh-Tuan

2017-06-01

In this study, multifunctional nanocomposites consisting of silver nanoparticles and manganese ferrite nanoparticles (Ag-MnFe2O4) were successfully synthesized using a two-step chemical process. The formation of Ag-MnFe2O4 nanocomposites were analyzed by transmission electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy measurements. Noticeable antibacterial activity of the Ag-MnFe2O4 nanocomposites was demonstrated against two Gram-negative bacteria, Salmonella enteritidis and Klebsiella pneumoniae. A direct-drop diffusion method can be an effective way to investigate the antibacterial effects of nanocomposite samples. Interestingly, we also demonstrated the use of Ag-MnFe2O4 nanocomposites as a surface-enhanced Raman scattering (SERS) platform to detect and quantify trace amounts of organic dye in water solutions. The combination of Ag and MnFe2O4 nanoparticles opens opportunities for creating advantages such as targeted bactericidal delivery, recyclable capability, and sensitive SERS-based detection for advanced biomedicine and environmental monitoring applications.

Collaborative ring-trial of Dynabeads anti-Salmonella for immunomagnetic separation of stressed Salmonella cells from herbs and spices.

PubMed

Mansfield, L; Forsythe, S

1996-02-01

Eight laboratories participated in a Salmonella detection ring-trial which compared selective enrichment by conventional broths with immunomagnetic separation (IMS) using Dynabeads Anti-Salmonella. Laboratories analyzed six types of herbs and spices that were spiked with one of six freeze-dried Salmonella species. Each herb and spice analysis comprised of 12 samples (25 g each) which had been spiked at three different levels, plus a negative control and stored for one week prior to testing. Out of a total 468 samples analyzed, 195 (41.7%) were positive by both methods. Eighteen samples were positive only by IMS enrichment, in comparison with 19 positive samples by conventional enrichment broths and not IMS. These results confirm the potential use of IMS as an alternative to enrichment broths for Salmonella isolation.

Salmonella enterocolitis

MedlinePlus

... you: Eat foods such as turkey, turkey dressing, chicken, or eggs that have not been cooked well or stored properly Are around family members with a recent salmonella infection Have been in or worked in a ...

Oral vaccination with a live Salmonella Enteritidis/Typhimurium bivalent vaccine in layers induces cross-protection against caecal and internal organ colonization by a Salmonella Infantis strain.

PubMed

Eeckhaut, Venessa; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

2018-05-01

Salmonella is an important zoonotic agent, and poultry products remain one of the main sources of infection for humans. Salmonella Infantis is an emerging serotype in poultry worldwide, reflected by an increased prevalence in poultry flocks, on broiler meat and in human foodborne illness cases. In the current study, the efficacy of oral administration of a live monovalent Salmonella Enteritidis and a live bivalent Salmonella Enteritidis/Typhimurium vaccine, against a Salmonella Enteritidis and Infantis infection, was determined. Oral administration of the live vaccines to day-old chickens caused a decrease in caecal colonization by Salmonella Enteritidis, but not Infantis, at day 7, when challenged at day 2. Vaccination with the bivalent vaccine at day 1 resulted in a decreased spleen colonization by both Salmonella Infantis and Enteritidis. Twice (at day 1 and week 6) and thrice vaccination (at day 1, week 6 and 16) of laying hens with the bivalent vaccine resulted in a decreased caecal colonization by Salmonella Enteritidis and Infantis, and significantly lower oviduct colonization levels by Salmonella Enteritidis. These data show cross-protection against Salmonella Infantis by oral administration of live vaccine strains belonging to other serogroups. Copyright © 2018 Elsevier B.V. All rights reserved.

Ten years experience of Salmonella infections in Cambridge, UK.

PubMed

Matheson, Nicholas; Kingsley, Robert A; Sturgess, Katherine; Aliyu, Sani H; Wain, John; Dougan, Gordon; Cooke, Fiona J

2010-01-01

Review of all Salmonella infections diagnosed in the Cambridge area over 10 years. All Salmonella enterica isolated in the Clinical Microbiology Laboratory, Addenbrooke's Hospital between 1.1.1999 and 31.12.2008 were included. Patient demographics, serotype and additional relevant details (travel history, resistance-type, phage-type) were recorded. 1003 episodes of Salmonella gastroenteritis were confirmed by stool culture, representing 88 serotypes. Serotypes Enteritidis (59%), Typhimurium (4.7%), Virchow (2.6%), Newport (1.8%) and Braenderup (1.7%) were the 5 most common isolates. There were an additional 37 invasive Salmonella infections (32 blood cultures, 4 tissue samples, 1 CSF). 13/15 patients with Salmonella Typhi or Salmonella Paratyphi isolated from blood or faeces with an available travel history had returned from the Indian subcontinent. 8/10 S. Typhi or Paratyphi isolates tested had reduced susceptibility to fluoroquinolones (MIC > or = 0.125 mg/L). 7/21 patients with non-typhoidal Salmonella bacteraemia were known to be immunosuppressed. This study describes Salmonella serotypes circulating within a defined geographical area over a decade. Prospective molecular analysis of isolates of S. enterica by multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) detection will determine the geo-phylogenetic relationship of isolates within our region. 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved.

Toward practical SERS sensing

NASA Astrophysics Data System (ADS)

Zhao, Yiping

2012-06-01

Since its discovery more than 30 years ago, surface-enhanced Raman scattering (SERS) has been recognized as a highly sensitive detection technique for chemical and biological sensing and medical diagnostics. However, the practical application of this remarkably sensitive technique has not been widely accepted as a viable diagnostic method due to the difficulty in preparing robust and reproducible substrates that provide maximum SERS enhancement. Here, we demonstrate that the aligned silver nanorod (AgNR) array substrates engineered by the oblique angle deposition method are capable of providing extremely high SERS enhancement factors (>108). The substrates are large area, uniform, reproducible, and compatible with general microfabrication process. The enhancement factor depends strongly on the length and shape of the Ag nanorods and the underlying substrate coating. By optimizing AgNR SERS substrates, we show that SERS is able to detect trace amount of toxins, virus, bacteria, or other chemical and biological molecules, and distinguish different viruses/bacteria and virus/bacteria strains. The substrate can be tailored into a multi-well chip for high throughput screening, integrated into fiber tip for portable sensing, incorporated into fluid/microfluidic devices for in situ real-time monitoring, fabricated onto a flexible substrate for tracking and identification, or used as on-chip separation device for ultra-thin layer chromatography and diagnostics. By combining the unique SERS substrates with a handheld Raman system, it can become a practical and portable sensor system for field applications. All these developments have demonstrated that AgNR SERS substrates could play an important role in the future for practical clinical, industrial, defense, and security sensing applications.

Cross-sectional survey of indicator and pathogenic bacteria on vegetables sold from Asian vendors at farmers' markets in northern California.

PubMed

Pan, Fengguang; Li, Xunde; Carabez, Jennifer; Ragosta, Guy; Fernandez, Kristine L; Wang, Elaine; Thiptara, Anyarat; Antaki, Elizabeth; Atwill, Edward R

2015-03-01

A cross-sectional survey was conducted during summer 2013 to determine the occurrence of Escherichia coli, fecal coliforms (FCs), E. coli O157:H7, and Salmonella on raw vegetable commodities common to Asian cuisine from 21 vendors or farmers at six farmers' markets in northern California. Based on 242 samples from six commodities (basil, yardlong beans, bitter squash, okra, squash stems and leaves, cilantro), 100% of samples had detectable FCs and 20% had detectable E. coli. The mean concentrations were 0.67 log CFU/g and 1.26 log CFU per bundle for E. coli and 4.00 log CFU/g and 6.26 log CFU per bundle for FCs. Vegetables irrigated with ground versus surface water contained lower concentrations of FCs, but this difference was not observed for E. coli. Yardlong beans, bitter squash, and okra had lower levels of FCs compared with basil, cilantro, and squash stems and leaves. Sixteen (6.6%) samples had detectable levels of Salmonella serovars (Newport, Enteritidis, Agona, and Worthington), with the majority of positives found in cilantro and squash stems and leaves. There was a twofold higher probability of Salmonella contamination in samples from growers or vendors who stated that they used organic farming practices compared with samples from those using conventional farming practices. Lastly, the concentrations of FC and E. coli bacteria were significantly associated with Salmonella contamination: for each additional 100 CFU/g or bundle, the probability of Salmonella contamination increased by ∼15 and ∼30%, respectively. None of the samples had detectable E. coli O157:H7.

Immune Reaction and Survivability of Salmonella Typhimurium and Salmonella Infantis after Infection of Primary Avian Macrophages

PubMed Central

Braukmann, Maria; Methner, Ulrich; Berndt, Angela

2015-01-01

Salmonella serovars are differentially able to infect chickens. The underlying causes are not yet fully understood. Aim of the present study was to elucidate the importance of Salmonella Pathogenicity Island 1 and 2 (SPI-1 and -2) for the virulence of two non-host-specific, but in-vivo differently invasive, Salmonella serovars in conjunction with the immune reaction of the host. Primary avian splenic macrophages were inoculated with Salmonella enterica sub-species enterica serovar (S.) Typhimurium and S. Infantis. The number and viability of intracellular bacteria and transcription of SPI-1 and -2 genes by the pathogens, as well as transcription of immune-related proteins, surface antigen expression and nitric oxide production by the macrophages, were compared at different times post inoculation. After infection, both of the Salmonella serovars were found inside the primary macrophages. Invasion-associated SPI-1 genes were significantly higher transcribed in S. Infantis- than S. Typhimurium-infected macrophages. The macrophages counteracted the S. Infantis and S. Typhimurium infection with elevated mRNA expression of inducible nitric oxide synthase (iNOS), interleukin (IL)-12, IL-18 and lipopolysaccharide-induced tumor necrosis factor alpha factor (LITAF) as well as with an increased synthesis of nitric oxide. Despite these host cell attacks, S. Typhimurium was better able than S. Infantis to survive within the macrophages and transcribed higher rates of the SPI-2 genes spiC, ssaV, sifA, and sseA. The results showed similar immune reactions of primary macrophages after infection with both of the Salmonella strains. The more rapid and stronger transcription of SPI-2-related genes by intracellular S. Typhimurium compared to S. Infantis might be responsible for its better survival in avian primary macrophages. PMID:25811871

Salmonella surrogate reduction using industrial peanut dry roasting parameters

USDA-ARS?s Scientific Manuscript database

Studies were conducted to evaluate the effectiveness of industrial peanut dry roasting parameters in Salmonella reduction using a Salmonella surrogate, Enterococcus faecium, which is slightly more heat tolerant than Salmonella. Runner-type peanuts were inoculated with E. faecium and roasted in a lab...

Saccharomyces boulardii prevention of the hepatic injury induced by Salmonella Enteritidis infection.

PubMed

Wu, Daichao; Teng, Da; Wang, Xiumin; Dai, Changsong; Wang, Jianhua

2014-10-01

Salmonella enterica subsp. enterica serovar Enteritidis (Salmonella Enteritidis) is the predominant cause of serovar-associated food-borne outbreaks in many countries and causes significant clinical symptoms of liver injury, enteritis, and diarrheal diseases. Saccharomyces boulardii is used in clinical application for prophylaxis and the treatment of a variety of diseases caused by bacterial infection. We used a mouse model of Salmonella Enteritidis infection, which included pretreatment with S. boulardii, to reveal the protection mechanisms of S. boulardii against Salmonella Enteritidis infection, including the translocation of Salmonella Enteritidis to the liver 10 days after Salmonella Enteritidis challenge, and the colonisation of Salmonella Enteritidis and the formation of hepatic tissue lesions in mice after Salmonella Enteritidis challenge on the 10th day. Compared with Salmonella Enteritidis infection in mice, S. boulardii decreased Salmonella Enteritidis translocation to the liver by 96%, and 99% of Salmonella Enteritidis colonised the cecum on the 10th day. Saccharomyces boulardii also abated hepatic tissue injury caused by the infiltration of neutrophilic granulocytes, lymphocytes, and plasmocytes by decreasing the translocation of Salmonella to the liver. These findings demonstrated that S. boulardii is an effective agent in the prevention of the hepatic injury induced by Salmonella Enteritidis infection in a mouse model.

Salmonella burden in Lebanon.

PubMed

Malaeb, M; Bizri, A R; Ghosn, N; Berry, A; Musharrafieh, U

2016-06-01

Salmonellosis is a disease that represents a major public health concern in both developing and developed countries. The aim of this article is to evaluate the public health burden of Salmonella illness in Lebanon. The current scope of the Salmonella infection problem was assessed in relation to disease incidence and distribution with respect to age, gender and district. Factors that provide a better understanding of the magnitude of the problem were explored and highlighted. Data reported to the Epidemiologic Surveillance Department at the Lebanese Ministry of Public Health between 2001 and 2013 was reviewed. Information obtained was compared to information reported regionally and globally. The estimated true incidence was derived using multipliers from the CDC and Jordan. A literature review of all published data from Lebanon about Salmonella susceptibility/resistance patterns and its serious clinical complications was conducted. The estimated incidence was 13·34 cases/100 000 individuals, most cases occurred in the 20-39 years age group with no significant gender variation. Poor and less developed districts of Lebanon had the highest number of cases and the peak incidence was in summer. Reflecting on the projected incidence derived from the use of multipliers indicates a major discrepancy between what is reported and what is estimated. We conclude that data about Salmonella infection in Lebanon and many Middle Eastern and developing countries lack crucial information and are not necessarily representative of the true incidence, prevalence and burden of illness.

Antimicrobial resistance in zoonotic nontyphoidal Salmonella: an alarming trend?

PubMed

Michael, G B; Schwarz, S

2016-12-01

Zoonotic bacteria of the genus Salmonella have acquired various antimicrobial resistance properties over the years. The corresponding resistance genes are commonly located on plasmids, transposons, gene cassettes, or variants of the Salmonella Genomic Islands SGI1 and SGI2. Human infections by nontyphoidal Salmonella isolates mainly result from ingestion of contaminated food. The two predominantly found Salmonella enterica subsp. enterica serovars in the USA and in Europe are S. Enteritidis and S. Typhimurium. Many other nontyphoidal Salmonella serovars have been implicated in foodborne Salmonella outbreaks. Summary reports of the antimicrobial susceptibility patterns of nontyphoidal Salmonella isolates over time suggest a moderate to low level of antimicrobial resistance and multidrug-resistance. However, serovar-specific analyses showed in part a steady state, a continuous decline, or a recent increase in resistance to certain antimicrobial agents. Resistance to critically important antimicrobial agents, e.g. third-generation cephalosporins and (fluoro)quinolones is part of many monitoring programmes and the corresponding results confirm that extended-spectrum β-lactamases are still rarely found in nontyphoidal Salmonella serovars, whereas resistance to (fluoro)quinolones is prevalent at variable frequencies among different serovars from humans and animals in different countries. Although it is likely that nontyphoidal Salmonella isolates from animals represent a reservoir for resistance determinants, it is mostly unknown where and when Salmonella isolates acquired resistance properties and which exchange processes have happened since then. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Reduction of Salmonella in ground chicken using a bacteriophage.

PubMed

Grant, Ar'Quette; Parveen, Salina; Schwarz, Jurgen; Hashem, Fawzy; Vimini, Bob

2017-08-01

This study's goal was to ascertain the effectiveness of a commercially available Salmonella bacteriophage during ground chicken production focusing on: water source, different Salmonella serovars, and time. Salmonella-free boneless, skinless chicken meat was inoculated with 4.0 Log CFU/cm2 of either a cocktail of 3 Salmonella isolates derived from ground chicken (GC) or a cocktail of 3 Salmonella strains not isolated from ground chicken (non-GC). Bacteriophages were spread onto the chicken using sterile tap or filtered water for 30 min or 8 h. Salmonella was recovered using standard plating method. Greater Salmonella reduction was observed when the bacteriophage was diluted in sterile tap water than in sterile filtered water: 0.39 Log CFU/cm2 and 0.23 Log CFU/cm2 reduction after 30 min, respectively (P < 0.05). The non-GC isolates showed reductions of 0.71 Log CFU/cm2 and 0.90 Log CFU/cm2 after 30 min and 8 h, respectively (P < 0.05). The GC isolates were less sensitive to the bacteriophage: 0.39 Log CFU/cm2 and 0.67 Log CFU/cm2 reductions after 30 min and 8 h, respectively (P < 0.05). In conclusion, bacteriophage reduction was dependent on water used to dilute the bacteriophage, Salmonella's susceptibility to the bacteriophage, and treatment time. © 2017 Poultry Science Association Inc.

Initial contamination of chicken parts with Salmonella at retail and cross-contamination of cooked chicken with Salmonella from raw chicken during meal preparation.

PubMed

Oscar, T P

2013-01-01

The current study was undertaken to acquire data on contamination of chicken parts with Salmonella at retail and to acquire data on cross-contamination of cooked chicken with Salmonella from raw chicken during meal preparation. Whole raw chickens (n = 31) were obtained from local retail stores and cut into two wings, two breasts without skin or bones, two thighs, and two drumsticks. Data for cross-contamination were obtained by cutting up a sterile, cooked chicken breast with the same board and knife used to cut up the raw chicken. The board, knife, and latex gloves used by the food handler were not rinsed or washed before cutting up the sterile, cooked chicken breast, thus providing a worst-case scenario for cross-contamination. Standard curves for the concentration of Salmonella bacteria in 400 ml of buffered peptone water after 6 h of incubation of chicken parts as a function of the initial log number of Salmonella bacteria inoculated onto chicken parts were developed and used to enumerate Salmonella bacteria. Standard curves were not affected by the type of chicken part but did differ (P < 0.05) among the five isolates of Salmonella examined. Consequently, Salmonella bacteria were enumerated on naturally contaminated chicken parts using a standard curve developed with the serotype of Salmonella that was isolated from the original sample. The prevalence of contamination was 3 % (4 of 132), whereas the incidence of cross-contamination was 1.8 % (1 of 57). The positive chicken parts were a thigh from chicken 4, which contained 3 CFU of Salmonella enterica serotype Kentucky, and both wings, one thigh, and one cooked breast portion from chicken 15, which all contained 1 CFU of serotype 8,20:-:z(6). These results indicated that the poultry industry is providing consumers in the studied area with chicken that has a low prevalence and low number of Salmonella bacteria at retail and that has a low incidence and low level of cross-contamination of cooked chicken with

Survival and growth of Salmonella in salsa and related ingredients.

PubMed

Ma, Li; Zhang, Guodong; Gerner-Smidt, Peter; Tauxe, Robert V; Doyle, Michael P

2010-03-01

A large outbreak of Salmonella Saintpaul associated with raw jalapeño peppers, serrano peppers, and possibly tomatoes was reported in the United States in 2008. During the outbreak, two clusters of illness investigated among restaurant patrons were significantly associated with eating salsa. Experiments were performed to determine the survival and growth characteristics of Salmonella in salsa and related major ingredients, i.e., tomatoes, jalapeño peppers, and cilantro. Intact and chopped vegetables and different formulations of salsas were inoculated with a five-strain mixture of Salmonella and then stored at 4, 12, and 21 degrees C for up to 7 days. Salmonella populations were monitored during storage. Salmonella did not grow, but survived on intact tomatoes and jalapeño peppers, whereas significant growth at 12 and 21 degrees C was observed on intact cilantro. In general, growth of Salmonella occurred in all chopped vegetables when stored at 12 and 21 degrees C, with chopped jalapeño peppers being the most supportive of Salmonella growth. Regardless of differences in salsa formulation, no growth of Salmonella (initial inoculation ca. 3 log CFU/g) was observed in salsa held at 4 degrees C; however, rapid or gradual decreases in Salmonella populations were only observed in formulations that contained both fresh garlic and lime juice. Salmonella grew at 12 and 21 degrees C in salsas, except for those formulations that contained both fresh garlic and lime juice, in which salmonellae were rapidly or gradually inactivated, depending on salsa formulation. These results highlight the importance of preharvest pathogen contamination control of fresh produce and proper formulation and storage of salsa.

Direct feeding of microencapsulated bacteriophages to reduce Salmonella colonization in pigs

USDA-ARS?s Scientific Manuscript database

Salmonella shedding often increases in pigs following pre-slaughter transportation and/or lairage. We previously showed that administering anti-Salmonella bacteriophages to pigs by gavage significantly reduced Salmonella colonization when the pigs were exposed to a Salmonella-contaminated pen. In ...

Modeling of Salmonella Contamination in the Pig Slaughterhouse.

PubMed

Swart, A N; Evers, E G; Simons, R L L; Swanenburg, M

2016-03-01

In this article we present a model for Salmonella contamination of pig carcasses in the slaughterhouse. This model forms part of a larger QMRA (quantitative microbial risk assessment) on Salmonella in slaughter and breeder pigs, which uses a generic model framework that can be parameterized for European member states, to describe the entire chain from farm-to-consumption and the resultant human illness. We focus on model construction, giving mathematical formulae to describe Salmonella concentrations on individual pigs and slaughter equipment at different stages of the slaughter process. Variability among individual pigs and over slaughterhouses is incorporated using statistical distributions, and simulated by Monte Carlo iteration. We present the results over the various slaughter stages and show that such a framework is especially suitable to investigate the effect of various interventions. In this article we present the results of the slaughterhouse module for two case study member states. The model outcome represents an increase in average prevalence of Salmonella contamination and Salmonella numbers at dehairing and a decrease of Salmonella numbers at scalding. These results show good agreement when compared to several other QMRAs and microbiological studies. © 2016 Society for Risk Analysis.

Sources of Salmonellae in broiler chickens in Ontario.

PubMed Central

Hacking, W C; Mitchell, W R; Carlson, H C

1978-01-01

Sources of Salmonellae infecting broiler chicken flocks in Ontario were investigated from July, 1975 to April, 1976. Three broiler flocks were investigated on each of four farms which received chicks from a common hatchery. Samples of feed and new litter were preenriched in nonselective broth subcultured to Salmonella-selective enrichment broth and plated on Salmonella-selective differential agar.Samples of used litter, water, culled chicks, insects, mice, wild birds and environmental swabs were not cultured initially in the nonselective broth. Fecal samples from principal and occasional flock attendants were examined for Samonellae. Salmonella infection, as judged by contaminated flock litter was detected in six flocks on two of the farms while the flocks on the other farms remained negative. Salmonellae were isolated from 23 of 412 feed samples (nine serotypes), six of 35 new wood shaving samples (four serotypes), one of 29 pools of culled chick viscera (one serotype) and 44 of 267 used litter samples (14 serotypes). These results indicate that broiler chicken flocks were infected with diverse Salmonellae introduced in day old chicks, pelleted feeds, wood shavings and residual contamination from the preceding flock. PMID:743597

Assessment of 2 Salmonella enterica serovar Typhimurium-based vaccines against necrotic enteritis in reducing colonization of chickens by Salmonella serovars of different serogroups.

PubMed

Jiang, Yanfen; Kulkarni, Raveendra R; Parreira, Valeria R; Poppe, Cornelius; Roland, Kenneth L; Prescott, John F

2010-10-01

This study assessed the protective efficacy of oral vaccination with 2 experimental attenuated Salmonella Typhimurium-vectored vaccines for necrotic enteritis in protecting chickens against intestinal colonization by common serovars of Salmonella belonging to the 4 major serogroups affecting chickens. Birds were vaccinated orally with 1 × 10⁸ colony-forming units (CFU) of 1 of the vaccine strains χ9241 and χ9352, which express a plasmid-encoded partial recombinant hypothetical protein gene (tHP) of Clostridium perfringens, at days 1 and 7 of age, and then were challenged at 14 d of age with 10⁶ CFU of Salmonella serovars Anatum, Enteritidis, Heidelberg, Kentucky, or Typhimurium (representative serovars of serogroups B, C, D, and E). Birds were necropsied at 4 wk of age, and samples were collected to determine reduction in tissue and intestinal colonization. The chickens vaccinated with χ9241-tHP showed reduced colonization by Salmonella Enteritidis (serogroup D) and by Salmonella Heidelberg and Salmonella Typhimurium (serogroup B) compared with the control birds. No reduction in colonization was observed in the chickens vaccinated with χ9352-tHP. There was an association between the efficacy of these vaccine strains in protecting against necrotic enteritis, assessed on an earlier occasion, and their efficacy in protecting against Salmonella colonization. Thus, the choice of an attenuated Salmonella Typhimurium vaccine vector for delivery of heterologous antigens to chickens should be based partly on the vaccine's value in protecting against colonization by serovars within serogroups B and D. Such vectors would have the additional benefit of reducing colonization of important Salmonella serovars.

Assessment of 2 Salmonella enterica serovar Typhimurium-based vaccines against necrotic enteritis in reducing colonization of chickens by Salmonella serovars of different serogroups

PubMed Central

Jiang, Yanfen; Kulkarni, Raveendra R.; Parreira, Valeria R.; Poppe, Cornelius; Roland, Kenneth L.; Prescott, John F.

2010-01-01

This study assessed the protective efficacy of oral vaccination with 2 experimental attenuated Salmonella Typhimurium-vectored vaccines for necrotic enteritis in protecting chickens against intestinal colonization by common serovars of Salmonella belonging to the 4 major serogroups affecting chickens. Birds were vaccinated orally with 1 × 108 colony-forming units (CFU) of 1 of the vaccine strains χ9241 and χ9352, which express a plasmid-encoded partial recombinant hypothetical protein gene (tHP) of Clostridium perfringens, at days 1 and 7 of age, and then were challenged at 14 d of age with 106 CFU of Salmonella serovars Anatum, Enteritidis, Heidelberg, Kentucky, or Typhimurium (representative serovars of serogroups B, C, D, and E). Birds were necropsied at 4 wk of age, and samples were collected to determine reduction in tissue and intestinal colonization. The chickens vaccinated with χ9241-tHP showed reduced colonization by Salmonella Enteritidis (serogroup D) and by Salmonella Heidelberg and Salmonella Typhimurium (serogroup B) compared with the control birds. No reduction in colonization was observed in the chickens vaccinated with χ9352-tHP. There was an association between the efficacy of these vaccine strains in protecting against necrotic enteritis, assessed on an earlier occasion, and their efficacy in protecting against Salmonella colonization. Thus, the choice of an attenuated Salmonella Typhimurium vaccine vector for delivery of heterologous antigens to chickens should be based partly on the vaccine’s value in protecting against colonization by serovars within serogroups B and D. Such vectors would have the additional benefit of reducing colonization of important Salmonella serovars. PMID:21197226

Coconut and Salmonella Infection

PubMed Central

Schaffner, Carl P.; Mosbach, Klaus; Bibit, Venuso C.; Watson, Colin H.

1967-01-01

Raw, unprocessed coconut supports the growth of salmonellae as well as that of other enteric bacteria, salmonellae being particularly resistant to subsequent desiccation. Original contamination is not due to carriers or to polluted water supplies, but to contact with bacteria-containing soils followed by dispersion via infected coconut milk and shells. Pasteurization of raw coconut meat in a water bath at 80 C for 8 to 10 min effectively killed such bacteria, did not injure the product, and provided a prophylactic method now widely used by the coconut industry. PMID:5340650

Salmonella species isolated from animal feed in Iraq.

PubMed Central

Al-Hindawi, N; Taha, R R

1979-01-01

Of 700 animal feed samples, 32 (4.5%) harbored Salmonella. The highest percentage of contamination was found in sheep feed and local protein. A total of 17 Salmonella serotypes were identified. The most frequent serotypes were Salmonella meleagridis. S. bornum, S. montevideo, and S. drypool. S. bornum was isolated for the first time in Iraq and from both local feed and its ingredients. The common somatic group found was that of Salmonella group C; then came groups E, G, B, and D. Three serotypes (S. enteritidis, S. california, and S. muenchen) seemed to form a link of infection among feed, food, patients, and carriers. PMID:453836

Salmonella Typhimurium pneumonia in a patient with multiple myeloma.

PubMed

Khan, Sadia; Kumar, V Anil; Sidharthan, Neeraj; Mehta, Asmita; Backer, Binita; Dinesh, Kavitha R

2015-04-01

Pneumonia due to non-typhoidal Salmonella is a rarely reported entity. A fatal case of Salmonella pneumonia is reported here where Salmonella Typhimurium was isolated from the endotracheal aspirate and blood culture. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Detection of pathogens in food using a SERS-based assay in just a few hours

NASA Astrophysics Data System (ADS)

Shende, Chetan; Sengupta, Atanu; Huang, Hermes; Farquharson, Stuart

2014-05-01

In 2011 Escherichia, Listeria, and Salmonella species infected over 1.2 million people in the United States, resulting in over 23,000 hospitalizations and 650 deaths. In January 2013 President Obama signed into law the Food and Drug Administration (FDA) Food Safety Modernization Act (FSMA), which requires constant microbial testing of food processing equipment and food to minimize contamination and distribution of food tainted with pathogens. The challenge to preventing distribution and consumption of contaminated foods lies in the fact that just a few bacterial cells can rapidly multiply to millions, reaching infectious doses within a few days. Unfortunately, current methods used to detect these few cells rely on similar growth steps to multiply the cells to the point of detection, which also takes a few days. Consequently, there is a critical need for an analyzer that can rapidly extract and detect foodborne pathogens at 1000 colony forming units per gram of food in 1-2 hours (not days), and with a specificity that differentiates from indigenous microflora, so that false alarms are eliminated. In an effort to meet this need, we have been developing an assay that extracts such pathogens from food, selectively binds these pathogens, and produces surface-enhanced Raman spectra (SERS) when read by a Raman analyzer. Here we present SERS measurements of these pathogens in actual food samples using this assay.

Isolation of Salmonella Virchow from a fruit bat (Pteropus giganteus).

PubMed

Islam, Ausraful; Mikolon, Andrea; Mikoleit, Matthew; Ahmed, Dilruba; Khan, Salah Udddin; Sharker, M A Yushuf; Hossain, M Jahangir; Islam, Ariful; Epstein, Jonathan H; Zeidner, Nord; Luby, Stephen P

2013-12-01

Detection of zoonotic pathogens carried by bats is important both for understanding disease ecology and for developing preventive measures. Pteropus fruit bats have been identified as potential carriers of Salmonella enterica serotype Typhi. A cross-sectional study was conducted to determine the prevalence of Salmonella Typhi and other Salmonella serotypes in Pteropus giganteus fruit bats in Bangladesh. Rectal swabs were collected from 302 bats and cultured for Salmonella species. The bats were trapped in three districts (Faridpur, Rajbari, and Cox's Bazar). Salmonella Typhi was not found but one juvenile female bat from Faridpur district was positive for Salmonella Virchow. Close associations between frugivorous bats, humans, and livestock in rural Bangladesh make it likely that the bat was infected by consuming contaminated water.

Comparing validation of four ELISA-systems for detection of Salmonella derby- and Salmonella infantis-infected pigs.

PubMed

Roesler, Uwe; Szabo, Istvan; Matthies, Claudia; Albrecht, Kerstin; Leffler, Martin; Scherer, Kathrin; Nöckler, Karsten; Lehmann, Jörg; Methner, Ulrich; Hensel, Andreas; Truyen, Uwe

2011-01-01

The objective of this study was the comparative evaluation of four indirect Salmonella ELISA tests at study time approved in Germany to detect Salmonella infection in pigs.Three tests are based on a LPS-antigen mix and directed against specific IgG antibodies. The fourth test is based on a purified S. Typhimurium whole-cell lysate antigen and discriminates between Salmonella-specific IgM-, IgA-, and IgG- antibodies. In a longitudinal study, two groups of six weeks old hybrid piglets were orally infected with a porcine S. Infantis or S. Derby strain. Clinical and bacteriological parameters were monitored weekly during an observation period of 130 days after infection and serum samples were investigated in parallel with the respective ELISAs. Apparently, the LPS-based ELISA systems used in this study failed to recognize S. Infantis-infected pigs although those animals shed the pathogen in high amounts throughout the study until day 81 post infection (p. i.). In contrast, the isotype-specific Salmonella Typhimurium whole-cell-lysate based ELISA was capable of detecting Salmonella-infected pigs from day ten p. i. at all tested serotypes and revealed the highest sensitivity in detection of S. Infantis-infected pigs. Furthermore, it became apparent that the often used surveillance cut-off value of 40 OD% is not appropriate for intra-vitam detection of S. Infantis- and S. Derby-infected pigs. In contrast, the cut-off values of the ELISAs given by the suppliers result in considerable higher detection rates.

Chasing Salmonella Typhimurium in free range egg production system.

PubMed

Chousalkar, Kapil; Gole, Vaibhav; Caraguel, Charles; Rault, Jean-Loup

2016-08-30

Free range production systems are becoming a major source of egg production in Australia and worldwide. This study investigated shedding and ecology of Salmonella Typhimurium and Salmonella species in a free range layer flock, wild birds and foxes in the vicinity of the free range farm in different seasons. Shedding of Salmonella was significantly higher in summer. Within the shed, overall, Salmonella prevalence was highest in dust. Corticosterone level in faeces was highest in spring and lowest in winter. There was no direct association between the Salmonella shedding (MPN/gm) and corticosterone levels in faeces. Salmonella Typhimurium MLVA types isolated from fox and wild birds were similar to MLVA types isolated from layer flock and reported during human food borne illness. Wild birds and foxes appear to play an important role in S. Typhimurium ecology and food safety. Environmental factors could play a role in evolution of S. Typhimurium in free range environment. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Examination of predictors of Salmonella enterica contamination in cattle feedlot environments

USDA-ARS?s Scientific Manuscript database

Objective: To identify a “predictor” or “environmental marker” that can be used to estimate Salmonella prevalence in a given feedlot environment. Further, to examine the correlation between environmental Salmonella contamination, Salmonella fecal shedding status, and prevalence of Salmonella in per...

Toward Molecular Level of the “Salmonella-Victim” Ecology, Genetics, and Evolution

PubMed Central

Rumyantsev, S.N.

2004-01-01

Bacteria of the Salmonella genus are polypathogenic agents that can affect both men and animals, causing devastating and fatal illness. Despite considerable immunological, epidemiological, and genetic efforts, and increased understanding of how the Salmonella infection develops, many key questions concerning Salmonella infection remain unanswered. Salmonella can be carried as harmless commensals in some sectors of the population. In some individuals, however, the same microbes cause illness while others display immunity to primary Salmonella infection. Nothing is known about the molecular base of the Salmonella pathogenicity. Even the ability of Salmonella to destroy the victims cells has been the subject of century-long discussions. In this article, some key findings concerning ecology, molecular ecology, and cell level of the Salmonella infection genetics are summarized and interpreted from the viewpoint of evolutionary theory with certitude that this approach can help to decipher the undiscovered secrets of Salmonella infections epidemiology and pathogenesis, as well as the clinical course and severity, and to select ways for fighting against Salmonella. PMID:15105959

Salmonella paratyphi spondylitis: a case report.

PubMed

Kumar, Pradeep; Mahmoodi, Seyed Mohsen; Kalaparambil Moosa, Nooruddin; Edgar, Michael; Samt, Hussain Al; Hussain, Riyaz Amirali

2008-05-01

This is a case report of acute L3/4 vertebral osteomyelitis due to Salmonella paratyphi A confirmed by culture from vertebral needle biopsy. From a review of the literature this is the first reported case with bacteriological confirmation. The rarity of Salmonella paratyphi spondylitis and the options for treatment are discussed.

Preexisting Salmonella-specific immunity interferes with the subsequent development of immune responses against the Salmonella strains delivering H9N2 hemagglutinin.

PubMed

Hajam, Irshad Ahmed; Lee, John Hwa

2017-06-01

Recombinant Salmonella strains expressing foreign heterologous antigens have been extensively studied as promising live vaccine delivery vehicles. In this study, we constructed attenuated smooth (S-HA) and rough (R-HA) Salmonella strains expressing hemagglutinin (HA) of H9N2, a low pathogenic avian influenza A virus. We then investigated the HA-specific immune responses following oral immunization with either S-HA or R-HA strain in chicken model. We further examined the effects of the preexisting anti-Salmonella immunity on the subsequent elicitation of the HA and the Salmonella ompA specific immune responses. Our results showed that primary immunization with either the S-HA or the R-HA strain elicited comparable HA-specific immune responses and the responses were significantly (p<0.05) higher compared to the Salmonella vector control. When chickens were pre-immunized with the smooth Salmonella carrier alone and then vaccinated with either S-HA or R-HA strain 3, 6 and 9 weeks later, respectively, significant reductions were seen for HA-specific immune responses at week 6, a point which corresponded to the peak of the primary Salmonella-specific antibody responses. No reductions were seen at week 3 and 9, albeit, the HA-specific immune responses were boosted at week 9, a point which corresponded to the lowest primary Salmonella-specific antibody responses. The ompA recall responses remain refractory at week 3 and 6 following deliberate immunization with the carrier strain, but were significantly (p<0.05) increased at week 9 post-primary immunization. We conclude that preexisting anti-Salmonella immunity inhibits antigen-specific immune responses and this effect could be avoided by carefully selecting the time point when carrier-specific immune responses are relatively low. Copyright © 2017 Elsevier B.V. All rights reserved.

Fate of Salmonella Typhimurium in laboratory-scale drinking water biofilms.

PubMed

Schaefer, L M; Brözel, V S; Venter, S N

2013-12-01

Investigations were carried out to evaluate and quantify colonization of laboratory-scale drinking water biofilms by a chromosomally green fluorescent protein (gfp)-tagged strain of Salmonella Typhimurium. Gfp encodes the green fluorescent protein and thus allows in situ detection of undisturbed cells and is ideally suited for monitoring Salmonella in biofilms. The fate and persistence of non-typhoidal Salmonella in simulated drinking water biofilms was investigated. The ability of Salmonella to form biofilms in monoculture and the fate and persistence of Salmonella in a mixed aquatic biofilm was examined. In monoculture S. Typhimurium formed loosely structured biofilms. Salmonella colonized established multi-species drinking water biofilms within 24 hours, forming micro-colonies within the biofilm. S. Typhimurium was also released at high levels from the drinking water-associated biofilm into the water passing through the system. This indicated that Salmonella could enter into, survive and grow within, and be released from a drinking water biofilm. The ability of Salmonella to survive and persist in a drinking water biofilm, and be released at high levels into the flow for recolonization elsewhere, indicates the potential for a persistent health risk to consumers once a network becomes contaminated with this bacterium.

Salmonella Infections

USDA-ARS?s Scientific Manuscript database

Infections with bacteria of the genus Salmonella are responsible for both acute and chronic poultry diseases. These diseases cause economically significant losses for poultry producers in many nations and absorb large investments of public and private resources in testing and control efforts. Infect...

Salmonella infection and carriage in reptiles in a zoological collection.

PubMed

Clancy, Meredith M; Davis, Meghan; Valitutto, Marc T; Nelson, Kenrad; Sykes, John M

2016-05-01

OBJECTIVE To identify important subspecies and serovars of Salmonella enterica in a captive reptile population and clinically relevant risk factors for and signs of illness in Salmonella-positive reptiles. DESIGN Retrospective cross-sectional study. ANIMALS 11 crocodilians (4 samples), 78 snakes (91 samples), 59 lizards (57 samples), and 34 chelonians (23 samples) at the Bronx Zoo from 2000 through 2012. PROCEDURES Data pertaining to various types of biological samples obtained from reptiles with positive Salmonella culture results and the reptiles themselves were analyzed to determine period prevalence of and risk factors for various Salmonella-related outcomes. RESULTS Serovar distribution differences were identified for sample type, reptile phylogenetic family, and reptile origin and health. Salmonella enterica subsp enterica was the most common subspecies in Salmonella cultures (78/175 [45%]), identified across all reptilian taxa. Salmonella enterica subsp diarizonae was also common (42/175 [24%]) and was recovered almost exclusively from snakes (n = 33), many of which had been clinically ill (17). Clinically ill reptiles provided 37% (64) of Salmonella cultures. Factors associated with an increased risk of illness in reptiles with a positive culture result were carnivorous diet and prior confiscation. Snakes had a higher risk of illness than other reptile groups, whereas lizards had a lower risk. Bony changes, dermatitis, and anorexia were the most common clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE This study provided new information on Salmonella infection or carriage and associated clinical disease in reptiles. Associations identified between serovars or subspecies and reptile groups or clinical disease can guide management of Salmonella-positive captive reptiles.

Molecular characterization of Salmonella Paratyphi B dT+ and Salmonella Heidelberg from poultry and retail chicken meat in Colombia by pulsed-field gel electrophoresis

USDA-ARS?s Scientific Manuscript database

Salmonella Paratyphi B dT+ variant (also termed Salmonella Java) and Salmonella Heidelberg are human pathogens frequently isolated from poultry. As a step towards implementing the Colombian Integrated Program for Antimicrobial Resistant Surveillance (COIPARS), this study characterized molecular patt...

Salmonella serotypes in reptiles and humans, French Guiana.

PubMed

Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

2014-05-14

In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Salmonella paratyphi spondylitis: a case report

PubMed Central

Mahmoodi, Seyed Mohsen; Kalaparambil Moosa, Nooruddin; Edgar, Michael; Samt, Hussain Al; Hussain, Riyaz Amirali

2007-01-01

This is a case report of acute L3/4 vertebral osteomyelitis due to Salmonella paratyphi A confirmed by culture from vertebral needle biopsy. From a review of the literature this is the first reported case with bacteriological confirmation. The rarity of Salmonella paratyphi spondylitis and the options for treatment are discussed. PMID:18008092

[Salmonella spp. strains resistant to drugs].

PubMed

Białucha, Agata; Kozuszko, Sylwia; Gospodarek, Eugenia

2010-01-01

The aim of the study was retrospective analysis of Salmonella spp. strains isolated from patients of State Infectious Diseases Observatory Hospital of T. Browicz in Bydgoszcz (SZAK) and University of dr. A. Jurasz in Bydgoszcz (SU CM UMK) in 2006-2009. The percentages of Salmonella spp. strains resistant to at least one drug were: 19,0% in 2006, 12,5% in 2007, 50,6% in 2008 and 43,8% in the first half of 2009 year. The highest number of Salmonella spp. strains resistant to drugs were isolated from stool (96,7%) and from patients of SZAK (83,3%). Among all isolated Salmonella spp. strains resistant to drugs the highest percentage were S. enterica serovar Enteritidis (56,7%). Among S. enterica bacilli predominated resitant phenotypes to ampicillin, amoxicillin, chloramphenicol and nalidixic acid. The increasing number of strains resistant to ciprofloxacin (0,0 - 26,7%) and high percentage of strains resistant to nalidixic acid (97,3%) were noted. Decreasing resistance to chloramphenicol was observed in our study (54,5 - 14,3%).

Presence of Salmonella Enteritidis and Salmonella Gallinarum in commercial laying hens diagnosed with Fowl Typhoid Disease in Colombia

USDA-ARS?s Scientific Manuscript database

: A severe outbreak of salmonellosis in commercial brown table egg layers first occurred in Colombia in 2006. From 2008 to 2012, 35 samples collected from commercial layers farms in the states of Cundinamarca, Santander, Bolivar and San Andres, were positive to Salmonella enterica. Salmonella (S) wa...

Salmonellae Associated with Further-processed Turkey Products1

PubMed Central

Bryan, Frank L.; Ayres, John C.; Kraft, Allen A.

1968-01-01

“Further-processed” turkey products, prepared from chilled, eviscerated, and thawed carcasses at two commercial turkey-processing plants, were evaluated, for the presence of salmonellae. These organisms were isolated from swab samples from 12% of chilled, eviscerated turkey carcasses, 27% of finished products, and 24% of processing equipment. The same serotypes as those found throughout a plant on any one visit were recovered from 31% of rinse-samples taken from hands and gloves of processing personnel. Salmonellae were found in samples taken on 37 of 48 visits; a greater number of recoveries were made on days when freshly killed turkeys were processed (87%) than when frozen-defrosted carcasses were processed (59%). The predominant serotype isolated from meat and environment usually changed from visit to visit. Salmonella sandiego and Salmonella anatum were the most frequent among 23 serotypes recovered. Most of the isolated serotypes are commonly associated with turkeys and have been incriminated as causative agents of human salmonellosis. The implication is that further-processed turkey products, if inadequately cooked by the consumer and if improperly refrigerated between the time of manufacture and consumption, could directly transmit salmonellae. These same products might also contaminate other foods by introducing salmonellae into food-preparation areas. PMID:5688832

Experimental optimization during SERS application

NASA Astrophysics Data System (ADS)

Laha, Ranjit; Das, Gour Mohan; Ranjan, Pranay; Dantham, Venkata Ramanaiah

2018-05-01

The well known surface enhanced Raman scattering (SERS) needs a lot of experimental optimization for its proper implementation. In this report, we demonstrate the efficient SERS using gold nanoparticles (AuNPs) on quartz plate. The AuNPs were prepared by depositing direct current sputtered Au thin film followed by suitable annealing. The parameters varied for getting best SERS effect were 1) Numerical Aperture of Raman objective lens and 2) Sputtering duration of Au film. It was found that AuNPs formed from the Au layer deposited for 40s and Raman objective lens of magnification 50X are the best combination for obtaining efficient SERS effect.

High prevalence and molecular characteristics of multidrug-resistant Salmonella in pigs, pork and humans in Thailand and Laos provinces.

PubMed

Sinwat, Nuananong; Angkittitrakul, Sunpetch; Coulson, Kari F; Pilapil, Flor Marie Immanuelle R; Meunsene, Dethaloun; Chuanchuen, Rungtip

2016-10-01

This study aimed to examine occurrence and antimicrobial resistance characteristics of Salmonella from pigs, pork and humans in Thailand and Laos provinces. The samples were collected from pigs, carcasses and workers in slaughterhouses, retail pork and butchers in fresh markets and patients in hospitals in Thailand (n=729) and Laos (n=458). A total of 295 of 729 samples (34.6 %) collected in Thailand and 253 of 458 (47.4 %) samples collected in Laos were positive for Salmonella. A total of 548 Salmonella isolates from Thailand (n=295) and Laos (n=253) were further analysed. Serovar Typhimurium was the most common serotype in Thai (34 %) and Laos (20.6 %) samples. Approximately 2.4 % of Thai isolates produced extended-spectrum β-lactamase (ESBL). All the ESBL producers possessed blaCTX-M-14, some of which were horizontally transferred. Class 1 integrons were common in Thai (31.9 %) and Laos (39.1 %) isolates, but none were associated with SGI1. The resistance cassette dfrA12-aadA2 was the most common, while the least common was aadA2-linG (n=1). The dfrA12-aadA2 gene cassette in five isolates and aadA2-linG were located on conjugative plasmid. Three pork isolates were fluoroquinolone resistant and carried an amino acid substitute, Ser-83-Tyr, in GyrA. The qnrS gene was found in 7.1 and 5.5 % of the Thai and Laos isolates, respectively, while qnrB was carried in another Laos isolate (1.9 %). All ESBL producers carried qnrS. In conclusion, multidrug-resistant Salmonella was common in pigs, pork and human samples in this region. The bacteria carried mobile genetic elements and resistance genes on conjugative plasmids that could be readily transferred to other bacterial species.

The effect of feeding diets containing avoparcin on the excretion of salmonellas by chickens experimentally infected with natural sources of salmonella organisms.

PubMed Central

Barrow, P. A.; Smith, H. W.; Tucker, J. F.

1984-01-01

Chickens were readily infected with salmonella organisms when fed diets containing unsterilized bone-meal or provided with drinking water containing a suspension of natural salmonella infected chicken faeces. When fed diets containing avoparcin at concentrations of 10 or 100 mg/kg chickens infected in these ways excreted larger numbers of salmonellas for longer periods than did chickens fed a nonmedicated diet. PMID:6512249

Seasonal stability of Cladophora-associated Salmonella in Lake Michigan watersheds.

PubMed

Byappanahalli, Muruleedhara N; Sawdey, Richard; Ishii, Satoshi; Shively, Dawn A; Ferguson, John A; Whitman, Richard L; Sadowsky, Michael J

2009-02-01

The bacterial pathogens Shigella, Salmonella, Campylobacter, and shiga toxin-producing E. coli (STEC) were recently found to be associated with Cladophora growing in southern Lake Michigan. Preliminary results indicated that the Salmonella strains associated with Cladophora were genetically identical to each other. However, because of the small sample size (n=37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between Cladophora and Salmonella remained speculative. In this study, we investigated the population structure and genetic relatedness of a large number of Cladophora-borne Salmonella isolates from Lake Michigan (n=133), as well as those isolated from stream and lake water (n=31), aquatic plants (n=8), and beach sands and sediments (n=8) from adjacent watersheds. Salmonella isolates were collected during 2005-2007 between May and August from Lake Michigan beachsheds in Wisconsin, Illinois, and Indiana. The genetic relatedness of Salmonella isolates was examined by using the horizontal, fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. While the Salmonella isolates associated with Cladophora exhibited a high degree of genetic relatedness (>or=92% similarity), the isolates were not all genetically identical. Spatial and temporal relationships were evident in the populations examined, with tight clustering of the isolates both by year and location. These findings suggest that the relationship between Salmonella and Cladophora is likely casual and is related to input sources (e.g. wastewater, runoff, birds) and the predominant Salmonella genotype surviving in the environment during a given season. Our studies indicate that Cladophora is likely an important reservoir for Salmonella and other enteric bacterial pathogens in Lake Michigan beachsheds, which in turn may influence nearshore water quality.

Seasonal stability of Cladophora-associated Salmonella in Lake Michigan watersheds

USGS Publications Warehouse

Byappanahalli, M.N.; Sawdey, R.; Ishii, S.; Shively, D.A.; Ferguson, J.A.; Whitman, R.L.; Sadowsky, M.J.

2009-01-01

The bacterial pathogens Shigella, Salmonella, Campylobacter, and shiga toxin-producing E. coli (STEC) were recently found to be associated with Cladophora growing in southern Lake Michigan. Preliminary results indicated that the Salmonella strains associated with Cladophora were genetically identical to each other. However, because of the small sample size (n = 37 isolates) and a lack of information on spatial-temporal relationships, the nature of the association between Cladophora and Salmonella remained speculative. In this study, we investigated the population structure and genetic relatedness of a large number of Cladophora-borne Salmonella isolates from Lake Michigan (n = 133), as well as those isolated from stream and lake water (n = 31), aquatic plants (n = 8), and beach sands and sediments (n = 8) from adjacent watersheds. Salmonella isolates were collected during 2005-2007 between May and August from Lake Michigan beachsheds in Wisconsin, Illinois, and Indiana. The genetic relatedness of Salmonella isolates was examined by using the horizontal, fluorophore-enhanced rep-PCR (HFERP) DNA fingerprinting technique. While the Salmonella isolates associated with Cladophora exhibited a high degree of genetic relatedness (???92% similarity), the isolates were not all genetically identical. Spatial and temporal relationships were evident in the populations examined, with tight clustering of the isolates both by year and location. These findings suggest that the relationship between Salmonella and Cladophora is likely casual and is related to input sources (e.g. wastewater, runoff, birds) and the predominant Salmonella genotype surviving in the environment during a given season. Our studies indicate that Cladophora is likely an important reservoir for Salmonella and other enteric bacterial pathogens in Lake Michigan beachsheds, which in turn may influence nearshore water quality. ?? 2008 Elsevier Ltd.

Diffuse abdominal gallium-67 citrate uptake in salmonella infections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garty, I.; Koren, A.

1987-11-01

Two pediatric patients with salmonella infections (one with typhoid fever and the second with salmonella C2 gastroenteritis), had a diffuse abdominal uptake of Ga-67 citrate. The possible explanation for this finding is discussed. Salmonella infection should be included as a cause in the differential diagnosis of diffuse accumulation of Ga-67 citrate.

Prevention of Salmonella cross-contamination in an oilmeal manufacturing plant.

PubMed

Morita, T; Kitazawa, H; Iida, T; Kamata, S

2006-08-01

The mechanisms of Salmonella contamination in an oilmeal plant were investigated and the basic data were collected in order to achieve control of Salmonella in oilmeal. Salmonella was detected in all contamination vectors and environmental factors investigated, namely: operators, processing floor, dust in the air and rodents. In particular, high concentrations of Salmonella were detected on the processing floor of the manufacturing area, which has high oil content. Steam was the most effective disinfection method used for the processing floor, as the effects of heat sterilization and disinfection may work in tandem. In addition, restricting the movement of operators of the production chain remarkably reduced Salmonella contamination, even in areas of otherwise high contamination. Within the oilmeal plant, high Salmonella contamination rates for the processing floor represent the greatest risk of contamination of oilmeal via operators, dust in the air and rodents. Therefore, control of the processing floor is the most important means for reducing the oilmeal contamination rate. Specific Salmonella control methods for oilmeal plants have been established.

Recombinant Salmonella Bacteria Vectoring HIV/AIDS Vaccines

PubMed Central

Chin’ombe, Nyasha; Ruhanya, Vurayai

2013-01-01

HIV/AIDS is an important public health problem globally. An affordable, easy-to-deliver and protective HIV vaccine is therefore required to curb the pandemic from spreading further. Recombinant Salmonella bacteria can be harnessed to vector HIV antigens or DNA vaccines to the immune system for induction of specific protective immunity. These are capable of activating the innate, humoral and cellular immune responses at both mucosal and systemic compartments. Several studies have already demonstrated the utility of live recombinant Salmonella in delivering expressed foreign antigens as well as DNA vaccines to the host immune system. This review gives an overview of the studies in which recombinant Salmonella bacteria were used to vector HIV/AIDS antigens and DNA vaccines. Most of the recombinant Salmonella-based HIV/AIDS vaccines developed so far have only been tested in animals (mainly mice) and are yet to reach human trials. PMID:24478808

The occurrence of Salmonella in airline meals.

PubMed

Hatakka, M; Asplund, K

1993-01-01

The occurrence of Salmonella in airline meals was studied in 1989-1992. Samples were collected from flight kitchens in 29 countries. The material consisted of 400 cold dishes and 1,288 hot dishes as well as salads, cheese plates and deserts. Total number of samples was 2211. Salmonella spp. were isolated from 6 samples; 1 contaminated sample was a cold dish prepared in Bangkok, 1 was a hot dish prepared in Mombasa and the remaining 4 contaminated samples were hot dishes prepared within one week in Beijing. The isolated serotypes were S. ohio, S. manchester and S. braenderup. The contaminated cold dish prepared by a flight kitchen in Bangkok was found to be connected with a Salmonella outbreak which occurred in Finland in 1990. Cold airline dishes containing food of animal origin seems to be more risky as a source of Salmonella infections among airline passengers.

Septic arthritis of the hip in a Cambodian child caused by multidrug-resistant Salmonella enterica serovar Typhi with intermediate susceptibility to ciprofloxacin treated with ceftriaxone and azithromycin.

PubMed

Pocock, J M; Khun, P A; Moore, C E; Vuthy, S; Stoesser, N; Parry, C M

2014-08-01

Septic arthritis is a rare complication of typhoid fever. A 12-year-old boy without pre-existing disease attended a paediatric hospital in Cambodia with fever and left hip pain. A hip synovial fluid aspirate grew multidrug-resistant Salmonella enterica ser. Typhi with intermediate susceptibility to ciprofloxacin. Arthrotomy, 2 weeks of intravenous ceftriaxone and 4 weeks of oral azithromycin led to resolution of symptoms. The optimum management of septic arthritis in drug-resistant typhoid is undefined.

Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate.

PubMed

Buja, Oana-M; Gordan, Ovidiu D; Leopold, Nicolae; Morschhauser, Andreas; Nestler, Jörg; Zahn, Dietrich R T

2017-01-01

A microfluidic setup which enables on-line monitoring of residues of malachite green (MG) using surface-enhanced Raman scattering (SERS) is reported. The SERS active substrate was prepared via laser induced synthesis of silver or gold nanoparticles spot on the bottom of a 200 μm inner dimension glass capillary, by focusing the laser beam during a continuous flow of a mixture of silver nitrate or gold chloride and sodium citrate. The described microfluidic setup enables within a few minutes the monitoring of several processes: the synthesis of the SERS active spot, MG adsorption to the metal surface, detection of the analyte when saturation of the SERS signal is reached, and finally, the desorption of MG from the spot. Moreover, after MG complete desorption, the regeneration of the SERS active spot was achieved. The detection of MG was possible down to 10 -7 M concentration with a good reproducibility when using silver or gold spots as SERS substrate.

Salmonella infections

USDA-ARS?s Scientific Manuscript database

Infections of poultry with bacteria of the genus Salmonella can cause clinical disease, but are of greater current concern as agents of food-borne transmission of illness to humans. However, two nonmotile organisms, S. Pullorum and S. Gallinarum, are host-specific for avian species. Pullorum disease...

Nutritional strategies to combat Salmonella in mono-gastric food animal production.

PubMed

Berge, A C; Wierup, M

2012-04-01

Nutritional strategies to minimize Salmonella in food animal production are one of the key components in producing safer food. The current European approach is to use a farm-to-fork strategy, where each sector must implement measures to minimize and reduce Salmonella contamination. In the pre-harvest phase, this means that all available tools need to be used such as implementation of biosecurity measures, control of Salmonella infections in animals at the farm as well as in transport and trade, optimal housing and management including cleaning, disinfection procedures as well as efforts to achieve Salmonella-free feed production. This paper describes some nutritional strategies that could be used in farm control programmes in the major mono-gastric food production animals: poultry and pigs. Initially, it is important to prevent the introduction of Salmonella onto the farm through Salmonella-contaminated feed and this risk is reduced through heat treatment and the use of organic acids and their salts and formaldehyde. Microbiological sampling and monitoring for Salmonella in the feed mills is required to minimize the introduction of Salmonella via feed onto the farm. In addition, feed withdrawal may create a stressful situation in animals, resulting in an increase in Salmonella shedding. Physical feed characteristics such as coarse-ground meal to pigs can delay gastric emptying, thereby increasing the acidity of the gut and thus reducing the possible prevalence of Salmonella. Coarse-ground grains and access to litter have also been shown to decrease Salmonella shedding in poultry. The feed can also modify the gastro-intestinal tract microflora and influence the immune system, which can minimize Salmonella colonization and shedding. Feed additives, such as organic acids, short- and medium-chain fatty acids, probiotics, including competitive exclusion cultures, prebiotics and certain specific carbohydrates, such as mannan-based compounds, egg proteins, essential oils

Samsung Salmonella Detection Kit. AOAC Performance Tested Method(SM) 021203.

PubMed

Li, Jun; Cheung, Win Den; Opdyke, Jason; Harvey, John; Chong, Songchun; Moon, Cheol Gon

2012-01-01

Salmonella, one of the most common causes of foodborne illness, is a significant public health concern worldwide. There is a need in the food industry for methods that are simple, rapid, and sensitive for the detection of foodborne pathogens. In this study, the Samsung Salmonella Detection Kit, a real-time PCR assay for the detection of Salmonella, was evaluated according to the current AOAC guidelines. The validation consisted of lot-to-lot consistency, stability, robustness, and inclusivity/exclusivity studies, as well as a method comparison of 10 different food matrixes. In the validation, the Samsung Salmonella Detection Kit was used in conjunction with the Applied Biosystems StepOnePlus PCR system and the Samsung Food Testing Software for the detection of Salmonella species. The performance of the assays was compared to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG) 4.05: Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Catfish and the and U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference methods. The validation was conducted using an unpaired study design for detection of Salmonella spp. in raw ground beef, raw pork, raw ground pork, raw chicken wings, raw salmon, alfalfa sprouts, pasteurized orange juice, peanut butter, pasteurized whole milk, and shell eggs. The Samsung Salmonella Detection Kit demonstrated lot-to-lot consistency among three independent lots as well as ruggedness with minor modifications to changes in enrichment incubation time, enrichment incubation temperature, and DNA sample volume for PCR reaction. Stability was observed for 13 months at -20 degrees C and 3 months at 5 degrees C. For the inclusivity/exclusivity study, the Samsung Salmonella Detection Kit correctly identified 147 Salmonella species isolates out of 147 isolates tested from each of three different enrichment

Salmonella contamination risk points in broiler carcasses during slaughter line processing.

PubMed

Rivera-Pérez, Walter; Barquero-Calvo, Elías; Zamora-Sanabria, Rebeca

2014-12-01

Salmonella is one of the foodborne pathogens most commonly associated with poultry products. The aim of this work was to identify and analyze key sampling points creating risk of Salmonella contamination in a chicken processing plant in Costa Rica and perform a salmonellosis risk analysis. Accordingly, the following examinations were performed: (i) qualitative testing (presence or absence of Salmonella), (ii) quantitative testing (Salmonella CFU counts), and (iii) salmonellosis risk analysis, assuming consumption of contaminated meat from the processing plant selected. Salmonella was isolated in 26% of the carcasses selected, indicating 60% positive in the flocks sampled. The highest Salmonella counts were observed after bleeding (6.1 log CFU per carcass), followed by a gradual decrease during the subsequent control steps. An increase in the percentage of contamination (10 to 40%) was observed during evisceration and spray washing (after evisceration), with Salmonella counts increasing from 3.9 to 5.1 log CFU per carcass. According to the prevalence of Salmonella -contaminated carcasses released to trade (20%), we estimated a risk of 272 cases of salmonellosis per year as a result of the consumption of contaminated chicken. Our study suggests that the processes of evisceration and spray washing represent a risk of Salmonella cross-contamination and/ or recontamination in broilers during slaughter line processing.

MALDI-TOF mass spectrometry provides high accuracy in identification of Salmonella at species level but is limited to type or subtype Salmonella serovars.

PubMed

Kang, Lin; Li, Nan; Li, Ping; Zhou, Yang; Gao, Shan; Gao, Hongwei; Xin, Wenwen; Wang, Jinglin

2017-04-01

Salmonella can cause global foodborne illnesses in humans and many animals. The current diagnostic gold standard used for detecting Salmonella infection is microbiological culture followed by serological confirmation tests. However, these methods are complicated and time-consuming. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis offers some advantages in rapid identification, for example, simple and fast sample preparation, fast and automated measurement, and robust and reliable identification up to genus and species levels, possibly even to the strain level. In this study, we established a reference database for species identification using whole-cell MALDI-TOF MS; the database consisted of 12 obtained main spectra of the Salmonella culture collection strains belonged to seven serotypes. Eighty-two clinical isolates of Salmonella were identified using established database, and partial 16S rDNA gene sequencing and serological method were used as comparison. We found that MALDI-TOF mass spectrometry provided high accuracy in identification of Salmonella at species level but was limited to type or subtype Salmonella serovars. We also tried to find serovar-specific biomarkers and failed. Our study demonstrated that (a) MALDI-TOF MS was suitable for identification of Salmonella at species level with high accuracy and (b) that MALDI-TOF MS method presented in this study was not useful for serovar assignment of Salmonella currently, because of its low matching with serological method and (c) MALDI-TOF MS method presented in this study was not suitable to subtype S. typhimurium because of its low discriminatory ability.

Cross contamination of turkey carcasses by Salmonella species during defeathering.

PubMed

Nde, C W; McEvoy, J M; Sherwood, J S; Logue, C M

2007-01-01

Salmonella present on the feathers of live birds could be a source of contamination to carcass skin during defeathering. In this study, the possibility of transfer of Salmonella from the feathers of live turkeys to carcass tissue during the defeathering process at a commercial turkey processing plant was investigated. The contribution of scald water and the fingers of the picker machines to cross contamination were also examined. Over 4 visits, swab samples were collected from 174 randomly selected tagged birds before and after defeathering. Two swab samples from the fingers of the picker machines and a sample of scald water were also collected during each visit. Detection of Salmonella was carried out following standard cultural and identification methods. The DNA fingerprints obtained from pulsed field gel electrophoresis of Salmonella serotypes isolated before and after defeathering, from scald water, and from the fingers of the picker machines were compared to trace cross contamination routes. Salmonella prevalence was similar before and after defeathering during visits 2 and 3 and significantly increased after defeathering during visits 1 and 4. Over the 4 visits, all Salmonella subtypes obtained after defeathering were also isolated before defeathering. The results of this study suggest that Salmonella was transferred from the feathers to carcass skin during each visit. On each visit, the Salmonella subtypes isolated from the fingers of the picker machines were similar to subtypes isolated before and after defeathering, indicating that the fingers facilitate carcass cross contamination during defeathering. Salmonella isolated from scald water during visit 4 was related to isolates obtained before and after defeathering, suggesting that scald water is also a vehicle for cross contamination during defeathering. By using molecular subtyping, this study demonstrated the relationship between Salmonella present on the feathers of live turkeys and carcass skin after

Case report of Salmonella cross-contamination in a food laboratory.

PubMed

Rasschaert, Geertrui; De Reu, K; Heyndrickx, M; Herman, L

2016-03-10

This paper describes a case of Salmonella cross-contamination in a food laboratory. In 2012, chocolate bars shipped from Belgium to the USA were prevented from entering the USA because a Salmonella Rissen strain had been isolated from one of the chocolate bars in a Belgian food laboratory. However, a retrospective study of the Salmonella isolates sent from the laboratory to the Belgian National Reference Laboratory for Salmonella revealed that 7 weeks prior, a Salmonella Rissen strain has been isolated from fish meal in the same food laboratory. The chocolate bars were not expected to be contaminated with Salmonella because the ingredients all tested negative during the production process. Furthermore, because Salmonella Rissen is only rarely isolated from food, it was hypothesized that the two Salmonella Rissen isolates belonged to the same strain and that the second isolation event in this laboratory was caused by cross-contamination. To confirm this hypothesis, both Salmonella Rissen isolates were fingerprinted using different molecular techniques. To evaluate the discriminatory power of the techniques used, 11 other Salmonella Rissen isolates from different origins were included in the comparison. Pulsed-field gel electrophoresis, repetitive element palindromic PCR and three random amplified polymorphic DNA PCR assays were used. Repetitive element palindromic PCR and random amplified polymorphic DNA PCR assays were insufficiently discriminatory, whereas pulsed-field gel electrophoresis using the combination of two restriction enzymes showed sufficient discrimination to confirm the hypothesis. Although cross-contamination in food laboratories are rarely reported, cross-contamination can always occur. Laboratories should therefore always be aware of the possibility of cross-contamination, especially when enrichment is used in the microbiological analysis. Furthermore, it is advised that results showing isolates of the same serotype isolated in a short time frame

Fate of Salmonella throughout Production and Refrigerated Storage of Tahini.

PubMed

Zhang, Yangjunna; Keller, Susanne E; Grasso-Kelley, Elizabeth M

2017-06-01

Tahini, a low-moisture food that is made from sesame seeds, has been implicated in outbreaks of salmonellosis. In this study, the fate of Salmonella was determined through an entire process for the manufacture of tahini, including a 24-h seed soaking period before roasting, subsequent grinding, and storage at refrigeration temperature. Salmonella populations increased by more than 3 log CFU/g during a 24-h soaking period, reaching more than 7 log CFU/g. Survival of Salmonella during roasting at three temperatures, 95, 110, and 130°C, was assessed using seeds on which Salmonella was grown. Salmonella survival was impacted both by temperature and the water activity (a w ) at the beginning of the roasting period. When roasted at 130°C with a high initial a w (≥0.90) and starting Salmonella populations of ∼8.5 log CFU/g, populations quickly decreased below detection limits within the first 10 min. However, when the seeds were reduced to an a w of 0.45 before roasting at the same temperature, 3.5 log CFU/g remained on the seeds after 60 min. In subsequent storage studies, seeds were roasted at 130°C for 15 min before processing into tahini. For the storage studies, tahini was inoculated using two methods. The first method used seeds on which Salmonella was first grown before roasting. In the second method, Salmonella was inoculated into the tahini after manufacture. All tahini was stored for 119 days at 4°C. No change in Salmonella populations was recorded for tahini throughout the entire 119 days regardless of the inoculation method used. These combined results indicate the critical importance of a w during a roasting step during tahini manufacture. Salmonella that survive roasting will likely remain viable throughout the normal shelf life of tahini.

Evaluation of the broad-spectrum lytic capability of bacteriophage cocktails against various Salmonella serovars and their effects on weaned pigs infected with Salmonella Typhimurium.

PubMed

Seo, Byoung-Joo; Song, Eu-Tteum; Lee, Kichan; Kim, Jong-Won; Jeong, Chang-Gi; Moon, Sung-Hyun; Son, Jee Soo; Kang, Sang Hyeon; Cho, Ho-Seong; Jung, Byeong Yeal; Kim, Won-Il

2018-06-06

The broad-spectrum lytic capability of Salmonella bacteriophages against various Salmonella species was evaluated to determine their potential as an alternative for antibiotics, and the safety and preventive effects of the bacteriophages were assessed on mice and pigs. Four bacteriophage cocktails were prepared using 13 bacteriophages, and the lytic capability of the four bacteriophage cocktails was tested using Salmonella reference strains and field isolates. Bacteriophage cocktail C (SEP-1, SGP-1, STP-1, SS3eP-1, STP-2, SChP-1, SAP-1, SAP-2; ≥10 9 pfu/ml) showed the best lytic activity against the Salmonella reference strains (100% of 34) and field isolates (92.5% of 107). Fifty mice were then orally inoculated with bacteriophage cocktail C to determine the distribution of bacteriophages in various organs, blood and feces. The effects of bacteriophages on Salmonella infection in weaned pigs (n=15) were also evaluated through an experimental challenge with Salmonella Typhimurium after treatment with bacteriophage cocktail C. All mice exhibited distribution of the bacteriophages in all organs, blood and feces until 15 days post infection (dpi). After 35 dpi, bacteriophages were not detected in any of these specimens. As demonstrated in a pig challenge study, treatment with bacteriophage cocktail C reduced the level of Salmonella shedding in feces. The metagenomic analyses of these pig feces also revealed that bacteriophage treatment decreased the number of species of the Enterobacteriaceae family without significant disturbance to the normal fecal flora. This study showed that bacteriophages effectively controlled Salmonella in a pig challenge model and could be a good alternative for antibiotics to control Salmonella infection.

Biofilm Formation and Morphotypes of Salmonella enterica subsp.arizonae Differs from Those of Other Salmonella enterica Subspecies in Isolates from Poultry Houses.

PubMed

Lamas, A; Fernandez-No, I C; Miranda, J M; Vázquez, B; Cepeda, A; Franco, C M

2016-07-01

Salmonella serovars are responsible for foodborne diseases around the world. The ability to form biofilms allows microorganisms to survive in the environment. In this study, 73 Salmonella strains, belonging to four different subspecies, were isolated from poultry houses and foodstuffs and tested. Biofilm formation was measured at four different temperatures and two nutrient concentrations. Morphotypes and cellulose production were evaluated at three different temperatures. The presence of several genes related to biofilm production was also examined. All strains and subspecies of Salmonella had the ability to form biofilms, and 46.57% of strains produced biofilms under all conditions tested. Biofilm formation was strain dependent and varied according to the conditions. This is the first study to analyze biofilm formation in a wide number of Salmonella enterica subsp. arizonae strains, and no direct relationship between the high prevalence of Salmonella enterica subsp. arizonae strains and their ability to form biofilm was established. Morphotypes and cellulose production varied as the temperature changed, with 20°C being the optimum temperature for expression of the red, dry, and rough morphotype and cellulose. Salmonella enterica subsp. arizonae, whose morphotype is poorly studied, only showed a smooth and white morphotype and lacked the csgD and gcpA genes that are implicated in biofilm production. Thus, Salmonella biofilm formation under different environmental conditions is a public health problem because it can survive and advance through the food chain to reach the consumer.

Survey of Salmonella contamination in chicken layer farms in three Caribbean countries.

PubMed

Adesiyun, Abiodun; Webb, Lloyd; Musai, Lisa; Louison, Bowen; Joseph, George; Stewart-Johnson, Alva; Samlal, Sannandan; Rodrigo, Shelly

2014-09-01

This study was conducted to investigate the demography, management, and production practices on layer chicken farms in Trinidad and Tobago, Grenada, and St. Lucia and the frequency of risk factors for Salmonella infection. The frequency of isolation of Salmonella from the layer farm environment, eggs, feeds, hatchery, and imported day-old chicks was determined using standard methods. Of the eight risk factors (farm size, age group of layers, source of day-old chicks, vaccination, sanitation practices, biosecurity measures, presence of pests, and previous disease outbreaks) for Salmonella infection investigated, farm size was the only risk factor significantly associated (P = 0.031) with the prevalence of Salmonella; 77.8% of large farms were positive for this pathogen compared with 33.3 and 26.1% of medium and small farms, respectively. The overall isolation rate of Salmonella from 35 layer farms was 40.0%. Salmonella was isolated at a significantly higher rate (P < 0.05) from farm environments than from the cloacae. Only in Trinidad and Tobago did feeds (6.5% of samples) and pooled egg contents (12.5% of samples) yield Salmonella; however, all egg samples from hotels, hatcheries, and airports in this country were negative. Salmonella Anatum, Salmonella group C, and Salmonella Kentucky were the predominant serotypes in Trinidad and Tobago, Grenada, and St. Lucia, respectively. Although Salmonella infections were found in layer birds sampled, table eggs appear to pose minimal risk to consumers. However, the detection of Salmonella -contaminated farm environments and feeds cannot be ignored. Only 2.9% of the isolates belonged to Salmonella Enteritidis, a finding that may reflect the impact of changes in farm management and poultry production in the region.

From Exit to Entry: Long-term Survival and Transmission of Salmonella

PubMed Central

Waldner, Landon L.; MacKenzie, Keith D.; Köster,, Wolfgang; White, Aaron P.

2012-01-01

Salmonella spp. are a leading cause of human infectious disease worldwide and pose a serious health concern. While we have an improving understanding of pathogenesis and the host-pathogen interactions underlying the infection process, comparatively little is known about the survival of pathogenic Salmonella outside their hosts. This review focuses on three areas: (1) in vitro evidence that Salmonella spp. can survive for long periods of time under harsh conditions; (2) observations and conclusions about Salmonella persistence obtained from human outbreaks; and (3) new information revealed by genomic- and population-based studies of Salmonella and related enteric pathogens. We highlight the mechanisms of Salmonella persistence and transmission as an essential part of their lifecycle and a prerequisite for their evolutionary success as human pathogens. PMID:25436767

Evaluation of Molecular Methods for Identification of Salmonella Serovars

PubMed Central

Gurnik, Simone; Ahmad, Aaminah; Blimkie, Travis; Murphy, Stephanie A.; Kropinski, Andrew M.; Nash, John H. E.

2016-01-01

Classification by serotyping is the essential first step in the characterization of Salmonella isolates and is important for surveillance, source tracking, and outbreak detection. To improve detection and reduce the burden of salmonellosis, several rapid and high-throughput molecular Salmonella serotyping methods have been developed. The aim of this study was to compare three commercial kits, Salm SeroGen (Salm Sero-Genotyping AS-1 kit), Check&Trace (Check-Points), and xMAP (xMAP Salmonella serotyping assay), to the Salmonella genoserotyping array (SGSA) developed by our laboratory. They were assessed using a panel of 321 isolates that represent commonly reported serovars from human and nonhuman sources globally. The four methods correctly identified 73.8% to 94.7% of the isolates tested. The methods correctly identified 85% and 98% of the clinically important Salmonella serovars Enteritidis and Typhimurium, respectively. The methods correctly identified 75% to 100% of the nontyphoidal, broad host range Salmonella serovars, including Heidelberg, Hadar, Infantis, Kentucky, Montevideo, Newport, and Virchow. The sensitivity and specificity of Salmonella serovars Typhimurium and Enteritidis ranged from 85% to 100% and 99% to 100%, respectively. It is anticipated that whole-genome sequencing will replace serotyping in public health laboratories in the future. However, at present, it is approximately three times more expensive than molecular methods. Until consistent standards and methodologies are deployed for whole-genome sequencing, data analysis and interlaboratory comparability remain a challenge. The use of molecular serotyping will provide a valuable high-throughput alternative to traditional serotyping. This comprehensive analysis provides a detailed comparison of commercial kits available for the molecular serotyping of Salmonella. PMID:27194688

In vitro selection of RNA aptamer specific to Salmonella typhimurium.

PubMed

Han, Seung Ryul; Lee, Seong-Wook

2013-06-28

Salmonella is a major foodborne pathogen that causes a variety of human diseases. Development of ligands directly and specifically binding to the Salmonella will be crucial for the rapid detection of, and thus for efficient protection from, the virulent bacteria. In this study, we identified a RNA aptamer-based ligand that can specifically recognize Salmonella Typhimurium through SELEX technology. To this end, we isolated and characterized an RNase-resistant RNA aptamer that bound to the OmpC protein of Salmonella Typhimurium with high specificity and affinity (Kd ~ 20 nM). Of note, the selected aptamer was found to specifically bind to Salmonella Typhimurium, but neither to Gram-positive bacteria (Staphylococcus aureus) nor to other Gram-negative bacteria (Escherichia coli O157:H7). This was evinced by aptamer-immobilized ELISA and aptamer-linked precipitation experiments. This Salmonella species-specific aptamer could be useful as a diagnostic ligand against pathogen-caused foodborne sickness.

Administration of a Salmonella Enteritidis ΔhilAssrAfliG strain by coarse spray to newly hatched broilers reduces colonization and shedding of a Salmonella Enteritidis challenge strain.

PubMed

De Cort, W; Haesebrouck, F; Ducatelle, R; van Immerseel, F

2015-01-01

Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans. Colonization inhibition (CI) occurs when a live Salmonella strain is administered to chickens and subsequently protects against challenge with another Salmonella strain belonging to the same serotype. A Salmonella Enteritidis hilAssrAfliG deletion mutant has previously been proven to reduce colonization and shedding of a wild-type Salmonella Enteritidis strain in newly hatched broilers after experimental infection. In this study, we compared two administration routes for this strain. Administering the Salmonella Enteritidis ΔhilAssrAfliG strain through drinking water on the first day of life resulted in decreased fecal shedding and cecal colonization of a wild-type Salmonella Enteritidis challenge strain administered 24 h later using a seeder-bird model. When administering the CI strain by coarse spray on newly hatched broiler chicks, an even more pronounced reduction of cecal colonization was observed, and fecal shedding of the Salmonella Enteritidis challenge strain ceased during the course of the experiment. These data suggest that administering a Salmonella Enteritidis ΔhilAssrAfliG strain to newly hatched chicks using a coarse spray is a useful and effective method that reduces colonization and shedding of a wild-type Salmonella Enteritidis strain after early challenge. © 2014 Poultry Science Association Inc.

Prevalence and antimicrobial susceptibility of salmonellae isolates from reptiles in Taiwan.

PubMed

Chen, Chun-Yu; Chen, Wan-Ching; Chin, Shih-Chien; Lai, Yen-Hsueh; Tung, Kwong-Chung; Chiou, Chien-Shun; Hsu, Yuan-Man; Chang, Chao-Chin

2010-01-01

Pets, including reptiles, have been shown to be a source of Salmonella infection in humans. Due to increasing popularity and variety of exotic reptiles as pets in recent years, more human clinical cases of reptile-associated Salmonella infection have been identified. However, limited information is available with regard to serotypes in different reptiles (turtles, snakes, and lizards) and antimicrobial resistance of Salmonella in pet reptiles. The current study was thus conducted to determine the prevalence of Salmonella colonization in pet reptiles. Salmonella organisms were isolated from 30.9% of 476 reptiles investigated. The isolation prevalences were 69.7% (23/33), 62.8% (27/43), and 24.3% (97/400) in snakes, lizards, and turtles, respectively. A total of 44 different Salmonella serovars were identified. Compared with S. Heron, Bredeney, Treforest, and 4,[5],12:i:-, S. Typhimurium isolates were resistant to many antimicrobials tested, and notably 61.1% of the isolates were resistant to cephalothin. The results indicated that raising reptiles as pets could be a possible source of Salmonella infection in humans, particularly zoonotic Salmonella serovars such as S. Typhimurium that may be resistant to antimicrobials.

Survival and Filamentation of Salmonella enterica Serovar Enteritidis PT4 and Salmonella enterica Serovar Typhimurium DT104 at Low Water Activity

PubMed Central

Mattick, K. L.; Jørgensen, F.; Legan, J. D.; Cole, M. B.; Porter, J.; Lappin-Scott, H. M.; Humphrey, T. J.

2000-01-01

In this study we investigated the long-term survival of and morphological changes in Salmonella strains at low water activity (aw). Salmonella enterica serovar Enteritidis PT4 and Salmonella enterica serovar Typhimurium DT104 survived at low aw for long periods, but minimum humectant concentrations of 8% NaCl (aw, 0.95), 96% sucrose (aw, 0.94), and 32% glycerol (aw, 0.92) were bactericidal under most conditions. Salmonella rpoS mutants were usually more sensitive to bactericidal levels of NaCl, sucrose, and glycerol. At a lethal aw, incubation at 37°C resulted in more rapid loss of viability than incubation at 21°C. At aw values of 0.93 to 0.98, strains of S. enterica serovar Enteritidis and S. enterica serovar Typhimurium formed filaments, some of which were at least 200 μm long. Filamentation was independent of rpoS expression. When the preparations were returned to high-aw conditions, the filaments formed septa, and division was complete within approximately 2 to 3 h. The variable survival of Salmonella strains at low aw highlights the importance of strain choice when researchers produce modelling data to simulate worst-case scenarios or conduct risk assessments based on laboratory data. The continued increase in Salmonella biomass at low aw (without a concomitant increase in microbial count) would not have been detected by traditional microbiological enumeration tests if the tests had been performed immediately after low-aw storage. If Salmonella strains form filaments in food products that have low aw values (0.92 to 0.98), there are significant implications for public health and for designing methods for microbiological monitoring. PMID:10742199

Maternal vaccination as a Salmonella Typhimurium reduction strategy on pig farms.

PubMed

Smith, R P; Andres, V; Martelli, F; Gosling, B; Marco-Jimenez, F; Vaughan, K; Tchorzewska, M; Davies, R

2018-01-01

The control of Salmonella in pig production is necessary for public and animal health, and vaccination was evaluated as a strategy to decrease pig prevalence. The study examined the efficacy of a live Salmonella Typhimurium vaccine, administered to sows on eight commercial farrow-to-finish herds experiencing clinical salmonellosis or Salmonella carriage associated with S. Typhimurium or its monophasic variants. Results of longitudinal Salmonella sampling were compared against eight similarly selected and studied control farms. At the last visit (~14 months after the start of vaccination), when all finishing stock had been born to vaccinated sows, both faecal shedding and environmental prevalence of Salmonella substantially declined on the majority of vaccinated farms in comparison to the controls. A higher proportion of vaccine farms resolved clinical salmonellosis than controls. However, Salmonella counts in positive faeces samples were similar between nonvaccinated and vaccinated herds. The results suggest that maternal vaccination is a suitable option for a Salmonella Typhimurium reduction strategy in farrow-to-finish pig herds. Salmonella vaccines have the potential to reduce the prevalence of Salmonella in pigs and result in a reduction of human cases attributed to pork. © 2017 Crown copyright. Journal of Applied Microbiology © 2017 The Society for Applied Microbiology. This article is published with the permission of the Controller of HMSO and the Queen’s Printer for Scotland.

Prophylactic administration of vector-encoded porcine granulocyte-colony stimulating factor reduces Salmonella shedding,tonsil colonization,& microbiota alterations of the gastrointestinal tract in Salmonella-challenged swine

USDA-ARS?s Scientific Manuscript database

Salmonella colonization of food animals is a concern for animal health and public health as a food safety risk. Various obstacles impede the effort to reduce asymptomatic Salmonella carriage in food animals, including the existence of numerous serovars and the ubiquitous nature of Salmonella. To d...

[A quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse].

PubMed

Zhang, Yu; Chen, Yuzhen; Hu, Chunguang; Zhang, Huaning; Bi, Zhenwang; Bi, Zhenqiang

2015-05-01

To construct a quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse and to find out effective interventions to reduce salmonella contamination. We constructed a modular process risk model (MPRM) from evisceration to chilling in Excel Sheet using the data of the process parameters in poultry and the Salmomella concentration surveillance of Jinan in 2012. The MPRM was simulated by @ risk software. The concentration of salmonella on carcass after chilling was 1.96MPN/g which was calculated by model. The sensitive analysis indicated that the correlation coefficient of the concentration of salmonella after defeathering and in chilling pool were 0.84 and 0.34,which were the primary factors to the concentration of salmonella on carcass after chilling. The study provided a quantitative assessment model structure for salmonella on carcass in poultry slaughterhouse. The risk manager could control the contamination of salmonella on carcass after chilling by reducing the concentration of salmonella after defeathering and in chilling pool.

Rapid Determination of Salmonella in Samples of Egg Noodles, Cake Mixes, and Candies

PubMed Central

Banwart, George J.; Kreitzer, Madeleine J.

1969-01-01

A glass apparatus system was compared with a standard enrichment broth-selective agar method to test samples of egg noodles, cake mixes, and candy for the presence or absence of salmonellae. The glass apparatus system used fermentation of mannitol, production of H2S, or motility, in conjunction with a serological test of flagellar antigens, to detect salmonellae. No salmonellae were detected in 173 samples of food products. Of these samples, 171 were found to be Salmonella-negative after 48 hr with the glass apparatus system. After 72 hr, the standard Salmonella procedure yielded 38 samples which produced Salmonella false-positive results on selective agars. Inoculation of samples with cultures of Salmonella showed that approximately one inoculated cell could be detected after 48 hr of incubation with the glass apparatus. The standard Salmonella test requires a minimum of 72 hr for completion. Compared with the standard Salmonella test, the glass apparatus system is a more rapid and simple system that can be used to determine the presence or absence of Salmonella in these food products. Images PMID:5370460

Salmonella and eggs: from production to plate.

PubMed

Whiley, Harriet; Ross, Kirstin

2015-02-26

Salmonella contamination of eggs and egg shells has been identified as a public health concern worldwide. A recent shift in consumer preferences has impacted on the egg industry, with a push for cage-free egg production methods. There has also been an increased desire from consumers for raw and unprocessed foods, potentially increasing the risk of salmonellosis. In response to these changes, this review explores the current literature regarding Salmonella contamination of eggs during the production processing through to food handling protocols. The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Currently there is no consensus regarding the impact of caged, barn and free range egg production has on Salmonella contamination of eggs. The literature regarding the management and control strategies post-collection, during storage, transport and food handling is also reviewed. Pasteurisation and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimise the risk for foods containing raw eggs; however, further research is required to provide more detailed control protocols and education programs to reduce the risk of salmonellosis from egg consumption.

Salmonella and Eggs: From Production to Plate

PubMed Central

Whiley, Harriet; Ross, Kirstin

2015-01-01

Salmonella contamination of eggs and egg shells has been identified as a public health concern worldwide. A recent shift in consumer preferences has impacted on the egg industry, with a push for cage-free egg production methods. There has also been an increased desire from consumers for raw and unprocessed foods, potentially increasing the risk of salmonellosis. In response to these changes, this review explores the current literature regarding Salmonella contamination of eggs during the production processing through to food handling protocols. The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Currently there is no consensus regarding the impact of caged, barn and free range egg production has on Salmonella contamination of eggs. The literature regarding the management and control strategies post-collection, during storage, transport and food handling is also reviewed. Pasteurisation and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimise the risk for foods containing raw eggs; however, further research is required to provide more detailed control protocols and education programs to reduce the risk of salmonellosis from egg consumption. PMID:25730295

Diversity of Antimicrobial Resistance Phenotypes in Salmonella Isolated from Commercial Poultry Farms.

PubMed

Liljebjelke, Karen A; Hofacre, Charles L; White, David G; Ayers, Sherry; Lee, Margie D; Maurer, John J

2017-01-01

Salmonella remains the leading cause of foodborne illness in the United States, and the dissemination of drug-resistant Salmonellae through the food chain has important implications for treatment failure of salmonellosis. We investigated the ecology of Salmonella in integrated broiler production in order to understand the flow of antibiotic susceptible and resistant strains within this system. Data were analyzed from a retrospective study focused on antimicrobial resistant Salmonella recovered from commercial broiler chicken farms conducted during the initial years of the US FDA's foray into retail meat surveillance by the National Antimicrobial Resistance Monitoring System (NARMS). Sixty-three percentage of Salmonella were pan-susceptible to a panel of 19 antimicrobials used by the NARMS program. Twenty-five antimicrobial resistance phenotypes were observed in Salmonella isolated from two broiler chicken farms. However, Salmonella displaying resistance to streptomycin, alone, and in combination with other antibiotics was the most prevalent (36.3%) antimicrobial resistance phenotype observed. Resistance to streptomycin and sulfadimethoxine appeared to be linked to the transposon, Tn 21 . Combinations of resistance against streptomycin, gentamicin, sulfadimethoxine, trimethoprim, and tetracycline were observed for a variety of Salmonella enterica serovars and genetic types as defined by pulsed-field gel electrophoresis. There were within and between farm differences in the antibiotic susceptibilities of Salmonella and some of these differences were linked to specific serovars. However, farm differences were not linked to antibiotic usage. Analysis of the temporal and spatial distribution of the endemic Salmonella serovars on these farms suggests that preventing vertical transmission of antibiotic-resistant Salmonella would reduce carcass contamination with antibiotic-resistant Salmonella and subsequently human risk exposure.

Diversity of Antimicrobial Resistance Phenotypes in Salmonella Isolated from Commercial Poultry Farms

PubMed Central

Liljebjelke, Karen A.; Hofacre, Charles L.; White, David G.; Ayers, Sherry; Lee, Margie D.; Maurer, John J.

2017-01-01

Salmonella remains the leading cause of foodborne illness in the United States, and the dissemination of drug-resistant Salmonellae through the food chain has important implications for treatment failure of salmonellosis. We investigated the ecology of Salmonella in integrated broiler production in order to understand the flow of antibiotic susceptible and resistant strains within this system. Data were analyzed from a retrospective study focused on antimicrobial resistant Salmonella recovered from commercial broiler chicken farms conducted during the initial years of the US FDA’s foray into retail meat surveillance by the National Antimicrobial Resistance Monitoring System (NARMS). Sixty-three percentage of Salmonella were pan-susceptible to a panel of 19 antimicrobials used by the NARMS program. Twenty-five antimicrobial resistance phenotypes were observed in Salmonella isolated from two broiler chicken farms. However, Salmonella displaying resistance to streptomycin, alone, and in combination with other antibiotics was the most prevalent (36.3%) antimicrobial resistance phenotype observed. Resistance to streptomycin and sulfadimethoxine appeared to be linked to the transposon, Tn21. Combinations of resistance against streptomycin, gentamicin, sulfadimethoxine, trimethoprim, and tetracycline were observed for a variety of Salmonella enterica serovars and genetic types as defined by pulsed-field gel electrophoresis. There were within and between farm differences in the antibiotic susceptibilities of Salmonella and some of these differences were linked to specific serovars. However, farm differences were not linked to antibiotic usage. Analysis of the temporal and spatial distribution of the endemic Salmonella serovars on these farms suggests that preventing vertical transmission of antibiotic-resistant Salmonella would reduce carcass contamination with antibiotic-resistant Salmonella and subsequently human risk exposure. PMID:28691011

The treatment of mouse colorectal cancer by oral delivery tumor-targeting Salmonella

PubMed Central

Wang, Wei-Kuang; Lu, Meng-Fan; Kuan, Yu-Diao; Lee, Che-Hsin

2015-01-01

Systemic administration of Salmonella to tumor-bearing mice leads to its preferential accumulation in tumor sites, the enhancement of host immunity, and the inhibition of tumor growth. However, the underlying mechanism for Salmonella-induced antitumor immune response via oral delivery remained uncertain. Herein, we used mouse colorectal cancer (CT26) as tumor model to study the therapeutic effects after oral delivery of Salmonella. When orally administered into tumor-bearing mice, Salmonella significantly accumulated in the tumor sites, inhibited tumor growth and extended the survival of mice. No obvious toxicity was observed during orally administered Salmonella by examining body weight and inflammatory cytokines. As indoleamine 2, 3-dioxygenase 1 (IDO) is a crucial mediator for tumor-mediated immune tolerance, we examined the expression of IDO. We demonstrated that Salmonella inhibited IDO expression in mouse cancer cells. Furthermore, immunohistochemical studies of the tumors revealed the infiltration of neutrophils and T cells in mice treated with Salmonella. In conclusion, our results indicate that Salmonella exerts its tumoricidal effects and stimulates T cell activities by inhibiting IDO expression. Oral delivery of Salmonella may, represent a potential strategy for the treatment of tumor. PMID:26328252

A Perspective on Invasive Salmonella Disease in Africa.

PubMed

Crump, John A; Heyderman, Robert S

2015-11-01

Salmonella enterica is a leading cause of community-acquired bloodstream infection in Africa. The contribution of typhoidal and nontyphoidal Salmonella serovars to invasive disease varies considerably in place and time, even within the same country. Nonetheless, many African countries are now thought to experience typhoid fever incidence >100 per 100,000 per year with approximately 1% of patients dying. Invasive nontyphoidal Salmonella (iNTS) disease was estimated to cause 3.4 million illnesses and 681 316 deaths in 2010, with the most disease in Africa. Antimicrobial drug resistance is a growing problem in S. enterica that threatens to further compromise patient outcomes. Reservoirs for nontyphoidal Salmonella and the predominant routes of transmission for typhoidal and nontyphoidal Salmonella are not well understood in Africa, hampering the design of evidence-based, non-vaccine- and vaccine-based prevention measures. It is difficult to distinguish clinically invasive Salmonella disease from febrile illnesses caused by other pathogens. Blood cultures are the mainstay of laboratory diagnosis, but lack sensitivity due to the low magnitude of bacteremia, do not produce results at point of care, and are not widely available in Africa. Serologic approaches to diagnosis remain inaccurate, and nucleic acid amplification tests are also compromised by low concentrations of bacteria. High-throughput whole-genome sequencing, together with a range of novel analytic pipelines, has provided new insights into the complex pattern of epidemiology, pathogenesis, and host adaptation. Concerted efforts are therefore needed to apply these new tools in the context of high-quality field surveillance to improve diagnosis, patient management, control, and prevention of invasive Salmonella infections in Africa. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Around the World in 1,475 Salmonella Geo-serotypes

PubMed Central

Le Hello, Simon; de Jong, Birgitta; Rolfhamre, Per; Faensen, Daniel; Weill, François-Xavier; Giesecke, Johan

2016-01-01

It’s easy to remember Salmonella serotypes names, isn’t it? Surely, this is because the naming system of Salmonella serotypes is by far the most scientist friendly. Traditionally, most Salmonella serotypes have been named after geographic locations. We decided to explore the geographic locations to which Salmonella serotypes refer and describe some unexpected twists in the naming scheme. We found that 93% (n = 1,475) of the 1,585 serotypes could be categorized as geo-serotypes; that is, the name refers to a geographic location. The 3 countries with the most geo-serotypes are Germany, the United Kingdom, and the United States. Other serotype names refer to the name of a person, animal, tribe, or food item or are a composite of symptoms and host. The Salmonella serotypes naming scheme has had a valuable effect on public health microbiology, and in the current era of fast development of whole-genome sequencing, it should remain a reference.

A Salmonella nanoparticle mimic overcomes multidrug resistance in tumours.

PubMed

Mercado-Lubo, Regino; Zhang, Yuanwei; Zhao, Liang; Rossi, Kyle; Wu, Xiang; Zou, Yekui; Castillo, Antonio; Leonard, Jack; Bortell, Rita; Greiner, Dale L; Shultz, Leonard D; Han, Gang; McCormick, Beth A

2016-07-25

Salmonella enterica serotype Typhimurium is a food-borne pathogen that also selectively grows in tumours and functionally decreases P-glycoprotein (P-gp), a multidrug resistance transporter. Here we report that the Salmonella type III secretion effector, SipA, is responsible for P-gp modulation through a pathway involving caspase-3. Mimicking the ability of Salmonella to reverse multidrug resistance, we constructed a gold nanoparticle system packaged with a SipA corona, and found this bacterial mimic not only accumulates in tumours but also reduces P-gp at a SipA dose significantly lower than free SipA. Moreover, the Salmonella nanoparticle mimic suppresses tumour growth with a concomitant reduction in P-gp when used with an existing chemotherapeutic drug (that is, doxorubicin). On the basis of our finding that the SipA Salmonella effector is fundamental for functionally decreasing P-gp, we engineered a nanoparticle mimic that both overcomes multidrug resistance in cancer cells and increases tumour sensitivity to conventional chemotherapeutics.

Serotype determination of Salmonella by xTAG assay.

PubMed

Zheng, Zhibei; Zheng, Wei; Wang, Haoqiu; Pan, Jincao; Pu, Xiaoying

2017-10-01

Currently, no protocols or commercial kits are available to determine the serotypes of Salmonella by using Luminex MAGPIX®. In this study, an xTAG assay for serotype determination of Salmonella suitable for Luminex MAGPIX® is described and 228 Salmonella isolates were serotype determined by this xTAG assay. The xTAG assay consists of two steps: 1) Multiplex PCR to amplify simultaneously O, H and Vi antigen genes of Salmonella, and 2) Magplex-TAG™ microsphere hybridization to identify accurately the specific PCR products of different antigens. Compared with the serotyping results of traditional serum agglutination test, the sensitivity and specificity of the xTAG assay were 95.1% and 100%, respectively. The agreement rate of these two assays was 95.2%. Compared with Luminex xMAP® Salmonella Serotyping Assay (SSA) kit, the advantages of this xTAG assay are: First, the magnetic beads make it applicable to both the Luminex®100/200™ and MAGPIX® systems. Second, only primers rather than both primers and probes are needed in the xTAG assay, and the process of coupling antigen-specific oligonucleotide probes to beads is circumvented, which make the xTAG assay convenient to be utilized by other laboratories. The xTAG assay may serve as a rapid alternative or complementary method for traditional Salmonella serotyping tests, especially for laboratories that utilize the MAGPIX® systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Salmonella-host cell interactions, changes in host cell architecture, and destruction of prostate tumor cells with genetically altered Salmonella.

PubMed

Zhong, Zhisheng; Kazmierczak, Robert A; Dino, Alison; Khreis, Rula; Eisenstark, Abraham; Schatten, Heide

2007-10-01

Increasingly, genetically modified Salmonella are being explored as a novel treatment for cancer because Salmonella preferentially replicate within tumors and destroy cancer cells without causing the septic shock that is typically associated with wild-type S. typhimurium infections. However, the mechanisms by which genetically modified Salmonella strains preferentially invade cancer cells have not yet been addressed in cellular detail. Here we present data that show S. typhimurium strains VNP20009, LT2, and CRC1674 invasion of PC-3M prostate cancer cells. S. typhimurium-infected PC-3M human prostate cancer cells were analyzed with immunofluorescence microscopy and transmission electron microscopy (TEM) at various times after inoculation. We analyzed microfilaments, microtubules, and DNA with fluorescence and immunofluorescence microscopy. 3T3 Phi-Yellow-mitochondria mouse 3T3 cells were used to study the effects of Salmonella infestation on mitochondria distribution in live cells. Our TEM results show gradual destruction of mitochondria within the PC-3M prostate cancer cells with complete loss of cristae at 8 h after inoculation. The fluorescence intensity in YFP-mitochondria-transfected mouse 3T3 cells decreased, which indicates loss of mitochondria structure. Interestingly, the nucleus does not appear affected by Salmonella within 8 h. Our data demonstrate that genetically modified S. typhimurium destroy PC-3M prostate cancer cells, perhaps by preferential destruction of mitochondria.

MicroSEQ® Salmonella spp. Detection Kit Using the Pathatrix® 10-Pooling Salmonella spp. Kit Linked Protocol Method Modification.

PubMed

Wall, Jason; Conrad, Rick; Latham, Kathy; Liu, Eric

2014-03-01

Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time to results compared to traditional culture methods. The addition of a recirculating pooled immunomagnetic separation method prior to real-time PCR analysis increases processing output while reducing both cost and labor. This AOAC Research Institute method modification study validates the MicroSEQ® Salmonella spp. Detection Kit [AOAC Performance Tested Method (PTM) 031001] linked with the Pathatrix® 10-Pooling Salmonella spp. Kit (AOAC PTM 090203C) in diced tomatoes, chocolate, and deli ham. The Pathatrix 10-Pooling protocol represents a method modification of the enrichment portion of the MicroSEQ Salmonella spp. The results of the method modification were compared to standard cultural reference methods for diced tomatoes, chocolate, and deli ham. All three matrixes were analyzed in a paired study design. An additional set of chocolate test portions was analyzed using an alternative enrichment medium in an unpaired study design. For all matrixes tested, there were no statistically significant differences in the number of positive test portions detected by the modified candidate method compared to the appropriate reference method. The MicroSEQ Salmonella spp. protocol linked with the Pathatrix individual or 10-Pooling procedure demonstrated reliability as a rapid, simplified, method for the preparation of samples and subsequent detection of Salmonella in diced tomatoes, chocolate, and deli ham.

Global Screening of Salmonella enterica Serovar Typhimurium Genes for Desiccation Survival

PubMed Central

Mandal, Rabindra K.; Kwon, Young M.

2017-01-01

Salmonella spp., one of the most common foodborne bacterial pathogens, has the ability to survive under desiccation conditions in foods and food processing facilities for years. This raises the concerns of Salmonella infection in humans associated with low water activity foods. Salmonella responds to desiccation stress via complex pathways involving immediate physiological actions as well as coordinated genetic responses. However, the exact mechanisms of Salmonella to resist desiccation stress remain to be fully elucidated. In this study, we screened a genome-saturating transposon (Tn5) library of Salmonella Typhimurium (S. Typhimurium) 14028s under the in vitro desiccation stress using transposon sequencing (Tn-seq). We identified 61 genes and 6 intergenic regions required to overcome desiccation stress. Salmonella desiccation resistance genes were mostly related to energy production and conversion; cell wall/membrane/envelope biogenesis; inorganic ion transport and metabolism; regulation of biological process; DNA metabolic process; ABC transporters; and two component system. More than 20% of the Salmonella desiccation resistance genes encode either putative or hypothetical proteins. Phenotypic evaluation of 12 single gene knockout mutants showed 3 mutants (atpH, atpG, and corA) had significantly (p < 0.02) reduced survival as compared to the wild type during desiccation survival. Thus, our study provided new insights into the molecular mechanisms utilized by Salmonella for survival against desiccation stress. The findings might be further exploited to develop effective control strategies against Salmonella contamination in low water activity foods and food processing facilities. PMID:28943871

Prevalence of Salmonella spp. in pet turtles and their environment

PubMed Central

Back, Du-San; Shin, Gee-Wook; Wendt, Mitchell

2016-01-01

Pet turtles are known as a source of Salmonella infection to humans when handled in captivity. Thirty four turtles purchased from pet shops and online markets in Korea were examined to determine whether the turtles and their environment were contaminated with Salmonella spp. Salmonella spp. were isolated from fecal samples of 17 turtles. These isolates were identified as S. enterica through 16S rRNA gene sequencing. The isolation rate of Salmonella spp. from the soil and water samples increased over time. We concluded that a high percentage of turtles being sold in pet shops were infected with Salmonella spp., and their environments tend to become contaminated over time unless they are maintained properly. These results indicate that pet turtles could be a potential risk of salmonellosis in Korea. PMID:27729933

Turtles as a Possible Reservoir of Nontyphoidal Salmonella in Shanghai, China

PubMed Central

Zhang, Jianmin; Kuang, Dai; Wang, Fei; Meng, Jianghong; Jin, Huiming; Yang, Xiaowei; Liao, Ming; Klena, John D.; Wu, Shuyu; Zhang, Yongbiao; Xu, Xuebin

2017-01-01

Terrapins and turtles are known to transmit Salmonella to humans. However, little was known about the occurrence of this pathogen in soft-shelled terrapin that is a popular delicacy in Chinese and other East Asian cuisines. We isolated and characterized 82 (24.4%) isolates of Salmonella from 336 fecal samples of soft-shelled terrapins (51 of 172; 29.7%) and pet turtles (31 of 164; 18.9%) in Shanghai. Salmonella Thompson was the most common serotype (17.1%) among others. Many isolates (84.1%) were resistant to multiple antimicrobials (≥3). Molecular analysis of Salmonella Thompson and Salmonella Typhimurium using pulsed-field gel electrophoresis unveiled a close genetic relationship between several human and terrapin isolates. Our results highlight the risk associated with the handling and consumption of turtles and their role in the spread of Salmonella in the human salmonellosis. PMID:27267492

Salmonella rarely detected in Mississippi coastal waters and sediment.

PubMed

Carr, M R; Wang, S Y; McLean, T I; Flood, C J; Ellender, R D

2010-12-01

Standards for the rapid detection of individual pathogens from environmental samples have not been developed, but in their absence, the use of molecular-based detection methods coupled with traditional microbiology techniques allows for rapid and accurate pathogen detection from environmental waters and sediment. The aim of this research was to combine the use of enrichment with PCR for detection of Salmonella in Mississippi coastal waters and sediment and observe if that presence correlated with levels of enterococci and climatological variables. Salmonella were primarily found in samples that underwent nutrient enrichment and were present more frequently in freshwater than marine waters. Salmonella were detected infrequently in marine and freshwater sediments. There was a significant positive correlation between the presence of detectable Salmonella and the average enterococcal count. An inverse relationship, however, was observed between the frequency of detection and the levels of salinity, turbidity and sunlight exposure. Results from this study indicated the presence of Salmonella in Mississippi coastal waters, and sediments are very low with significant differences between freshwater and marine environments. Using pathogenic and novel nonpathogenic molecular markers, Salmonella do not appear to be a significant pathogenic genus along the Mississippi Coast. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

SURVIVAL OF SALMONELLA IN WASTE EGG WASH WATER

EPA Science Inventory

The survival of salmonellae under various environmental conditions has been subject of numerous research studies. Due to low densities of these organisms in natural samples, laboratory or clinical cultures were used to ensure that the initial density of salmonellae was sufficien...

SERS-Active Nanoinjector for Intracellular Spectroscopy

NASA Astrophysics Data System (ADS)

Vitol, Elina; Orynbayeva, Zulfiya; Bouchard, Michael; Azizkhan-Clifford, Jane; Friedman, Gary; Gogotsi, Yury

2009-03-01

We developed a multifunctional nanopipette which allows simultaneous cell injection and intacellular surface-enhanced Raman spectroscopy (SERS) analysis. SERS spectra contain the characteristic frequencies of molecular bond vibrations. This is a unique method for studying cell biochemistry and physiology on a single organelle level. Unlike the fluorescence spectroscopy, it does not require any specific staining. The principle of SERS is based on very large electromagnetic field enhancement localized around a nano-rough metallic surface. Gold colloids are widely used SERS substrates. Previously, the colloidal nanoparticles were introduced into a cell by the mechanism of endocytosis. The disadvantage of this method is the uncontrollable aggregation and distribution of gold nanoparticles inside a cell which causes a significant uncertainty in the origin of the acquired data. At the same time, the nanoparticle uptake is irreversible. We present a SERS-active nanoinjector, coated with gold nanoparticles, which enables selective signal acquisition from any point-of-interest inside a cell. The nanoinjector provides a highly localized SERS signal with sub-nanometer resolution in real time.

A case-control study of domestic kitchen microbiology and sporadic Salmonella infection.

PubMed

Parry, S M; Slader, J; Humphrey, T; Holmes, B; Guildea, Z; Palmer, S R

2005-10-01

The microbiology of domestic kitchens in the homes of subjects who had suffered sporadic Salmonella infection (cases) was compared with control domestic kitchens. Case and control dishcloths and refrigerator swabs were examined for the presence of Salmonella spp., total Enterobacteriaceae counts and total aerobic colony counts. Salmonella spp. were isolated from both case and control dishcloths and refrigerators but there were no significant differences between the two groups. Colony counts were similar in case and control dishcloths and refrigerator swabs. There was no relationship between the total counts and presence of Salmonella . There was no evidence that cases of Salmonella infection were more likely to have kitchens which were contaminated with these bacteria or have higher bacterial counts than controls. Total bacterial counts were poor indicators of Salmonella contamination of the domestic kitchen environment. Further factors which could not be identified by a study of this design may increase risk of Salmonella food poisoning. These factors may include individual susceptibility of the patient. Alternatively, sporadic cases of Salmonella food poisoning may arise from food prepared outside the home.

Immunogenicity of Salmonella enterica serovar Enteritidis virulence protein, InvH, and cross-reactivity of its antisera with Salmonella strains.

PubMed

Dehghani, Behzad; Rasooli, Iraj; Gargari, Seyed Latif Mousavi; Nadooshan, Mohammad Reza Jalali; Owlia, Parviz; Nazarian, Shahram

2013-02-22

Acellular vaccines containing bacterial immunodominant components such as surface proteins may be potent alternatives to live attenuated vaccines in order to reduce salmonellosis risk to human health. invH gene, an important part of needle complex in type three secretion system (TTSS) plays important role in efficient bacterial adherence and entry into epithelial cells. In this work we hypothesize that use of a 15 kDa recombinant InvH as Salmonella enterica serovar Enteritidis surface protein could provoke antibody production in mouse and would help us study feasibility of its potential for diagnosis and/or a recombinant vaccine. The purified InvH provoked significant rise of IgG in mice. Active protection induced by immunization with InvH against variable doses of S. enterica serovar Enteritidis, indicated that the immunized mice were completely protected against challenge with 10(4) LD(50). The immunoreaction of sera from immunized mice with other Salmonella strains or cross reaction with sera of Salmonella strains inoculated mice is indicative of possessing by Salmonella strains of the surface protein, InvH, that can be employed in both prophylactic and diagnostic measures against S. enterica. Bacteria free spleen and ileum of the immunized mice in this study indicate that the invH gene affects bacterial invasion. Efficacy of the virulence protein, InvH, in shuttling into host cells in injectisome of S. enterica serovar Enteritidis and inhibition of this phenomenon by active immunization was shown in this study. In conclusion immunization with InvH protein can develop protection against S. enterica serovar Enteritidis infections. InvH in Salmonella strains can be exploited in protective measures as well as a diagnostic tool in Salmonella infections. Copyright © 2012 Elsevier GmbH. All rights reserved.

21 CFR 118.6 - Egg testing for Salmonella Enteritidis (SE).

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Egg testing for Salmonella Enteritidis (SE). 118.6... testing for Salmonella Enteritidis (SE). (a)(1) If the environmental test for pullets at 14 to 16 weeks of... requires that these eggs must be treated to achieve at least a 5-log destruction of Salmonella Enteritidis...

21 CFR 118.6 - Egg testing for Salmonella Enteritidis (SE).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Egg testing for Salmonella Enteritidis (SE). 118.6... testing for Salmonella Enteritidis (SE). (a)(1) If the environmental test for pullets at 14 to 16 weeks of... requires that these eggs must be treated to achieve at least a 5-log destruction of Salmonella Enteritidis...

21 CFR 118.6 - Egg testing for Salmonella Enteritidis (SE).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Egg testing for Salmonella Enteritidis (SE). 118.6... testing for Salmonella Enteritidis (SE). (a)(1) If the environmental test for pullets at 14 to 16 weeks of... requires that these eggs must be treated to achieve at least a 5-log destruction of Salmonella Enteritidis...

Dispersal of Salmonella Typhimurium by rain splash onto tomato plants.

PubMed

Cevallos-Cevallos, Juan M; Danyluk, Michelle D; Gu, Ganyu; Vallad, Gary E; van Bruggen, Ariena H C

2012-03-01

Outbreaks of Salmonella enterica have increasingly been associated with tomatoes and traced back to production areas, but the spread of Salmonella from a point source onto plants has not been described. Splash dispersal by rain could be one means of dissemination. Green fluorescent protein-labeled, kanamycin-resistant Salmonella enterica sv. Typhimurium dispensed on the surface of plastic mulch, organic mulch, or soil at 10⁸ CFU/cm² was used as the point source in the center of a rain simulator. Tomato plants in soil with and without plastic or organic mulch were placed around the point source, and rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Dispersal of Salmonella followed a negative exponential model with a half distance of 3 cm at 110 mm/h. Dispersed Salmonella survived for 3 days on tomato leaflets, with a total decline of 5 log and an initial decimal reduction time of 10 h. Recovery of dispersed Salmonella from plants at the maximum observed distance ranged from 3 CFU/g of leaflet after a rain episode of 110 mm/h for 10 min on soil to 117 CFU/g of leaflet on plastic mulch. Dispersal of Salmonella on plants with and without mulch was significantly enhanced by increasing rain duration from 0 to 10 min, but dispersal was reduced when rainfall duration increased from 10 to 30 min. Salmonella may be dispersed by rain to contaminate tomato plants in the field, especially during rain events of 10 min and when plastic mulch is used.

Relationship between aerobic bacteria, salmonellae and Campylobacter on broiler carcasses.

PubMed

Cason, J A; Bailey, J S; Stern, N J; Whittemore, A D; Cox, N A

1997-07-01

Broiler carcasses were removed from commercial processing lines immediately after defeathering, before chilling, and after chilling to determine whether any relationship exists between aerobic bacteria and the human enteropathogens salmonellae and Campylobacter. In two experiments, a whole carcass rinse procedure was used to sample 30 carcasses after defeathering, 90 carcasses before chilling, and 90 carcasses after chilling, for a total of 210 different carcasses. Aerobic bacteria and Campylobacter spp. were enumerated and the incidence of salmonellae was determined. Salmonellae and Campylobacter incidences were 20 and 94%, respectively, for all carcasses sampled. After picking, neither salmonellae-positive nor Campylobacter-positive carcasses had mean aerobic most probable number (MPN) values that were different from carcasses negative for those organisms. Immediately before chilling, aerobic and Campylobacter counts were 7.12 and 5.33 log10 cfu per carcass, respectively. Immersion chilling reduced aerobic counts by approximately 1.8 log and Campylobacter by 1.5 log, with no change in salmonellae-positive carcasses. There was no difference in aerobic or Campylobacter counts between carcasses that were positive or negative for salmonellae at any of the sampling locations, nor was any correlation found between levels of aerobic organisms and Campylobacter. Carcasses with aerobic counts above the mean or more than one standard deviation above the mean also failed to show any correlation. Discriminant analysis indicated error rates as high as 50% when numbers of aerobic bacteria were used to predict incidence of salmonellae or Campylobacter on individual carcasses. Aerobic bacteria are not suitable as index organisms for salmonellae or Campylobacter on broiler carcasses.

Observations on the distribution and control of Salmonella species in two integrated broiler companies.

PubMed

Davies, R; Breslin, M; Corry, J E; Hudson, W; Allen, V M

2001-08-25

The effectiveness of cleaning and disinfecting broiler farms and the persistence of Salmonella species in two integrated broiler companies was investigated for two years. Both companies used a cleaning and disinfection regime which included the application of a spray of phenolic disinfectant followed by fogging with formaldehyde solution, and this was highly effective in preventing carry-over of infection in the broiler houses. The disinfection of service areas and areas outside the houses was less effective but it had no influence on the Salmonella status of later flocks. Both companies had persistent problems with the contamination of pellet cooling systems in their feedmills with Salmonella 4, 12:d:- in company A, and with Salmonella binza and Salmonella ohio in company B. The hatcher incubators of both companies were also persistently contaminated with Salmonella livingstone and Salmonella thomasville in company A and with Salmonella senftenberg in company B. At both companies sites Salmonella enteritidis and Salmonella typhimurium Tr104 were also isolated occasionally from various locations.

One Health and Food-Borne Disease: Salmonella Transmission between Humans, Animals, and Plants.

PubMed

Silva, Claudia; Calva, Edmundo; Maloy, Stanley

2014-02-01

There are >2,600 recognized serovars of Salmonella enterica. Many of these Salmonella serovars have a broad host range and can infect a wide variety of animals, including mammals, birds, reptiles, amphibians, fish, and insects. In addition, Salmonella can grow in plants and can survive in protozoa, soil, and water. Hence, broad-host-range Salmonella can be transmitted via feces from wild animals, farm animals, and pets or by consumption of a wide variety of common foods: poultry, beef, pork, eggs, milk, fruit, vegetables, spices, and nuts. Broad-host-range Salmonella pathogens typically cause gastroenteritis in humans. Some Salmonella serovars have a more restricted host range that is associated with changes in the virulence plasmid pSV, accumulation of pseudogenes, and chromosome rearrangements. These changes in host-restricted Salmonella alter pathogen-host interactions such that host-restricted Salmonella organisms commonly cause systemic infections and are transmitted between host populations by asymptomatic carriers. The secondary consequences of efforts to eliminate host-restricted Salmonella serovars demonstrate that basic ecological principles govern the environmental niches occupied by these pathogens, making it impossible to thwart Salmonella infections without a clear understanding of the human, animal, and environmental reservoirs of these pathogens. Thus, transmission of S. enterica provides a compelling example of the One Health paradigm because reducing human infections will require the reduction of Salmonella in animals and limitation of transmission from the environment.

Specificity tests of an oligonucleotide probe against food-outbreak salmonella for biosensor detection

NASA Astrophysics Data System (ADS)

Chen, I.-H.; Horikawa, S.; Xi, J.; Wikle, H. C.; Barbaree, J. M.; Chin, B. A.

2017-05-01

Phage based magneto-elastic (ME) biosensors have been shown to be able to rapidly detect Salmonella in various food systems to serve food pathogen monitoring purposes. In this ME biosensor platform, the free-standing strip-shaped magneto-elastic sensor is the transducer and the phage probe that recognizes Salmonella in food serves as the bio-recognition element. According to Sorokulova et al. at 2005, a developed oligonucleotide probe E2 was reported to have high specificity to Salmonella enterica Typhimurium. In the report, the specificity tests were focused in most of Enterobacterace groups outside of Salmonella family. Here, to understand the specificity of phage E2 to different Salmonella enterica serotypes within Salmonella Family, we further tested the specificity of the phage probe to thirty-two Salmonella serotypes that were present in the major foodborne outbreaks during the past ten years (according to Centers for Disease Control and Prevention). The tests were conducted through an Enzyme linked Immunosorbent Assay (ELISA) format. This assay can mimic probe immobilized conditions on the magnetoelastic biosensor platform and also enable to study the binding specificity of oligonucleotide probes toward different Salmonella while avoiding phage/ sensor lot variations. Test results confirmed that this oligonucleotide probe E2 was high specific to Salmonella Typhimurium cells but showed cross reactivity to Salmonella Tennessee and four other serotypes among the thirty-two tested Salmonella serotypes.

Breast abscess in a man due to Salmonella enterica serotype Enteritidis.

PubMed

Brncic, Nada; Gorup, Lari; Strcic, Miroslav; Abram, Maja; Mustac, Elvira

2012-01-01

Nontyphoidal salmonellae can cause breast infection only exceptionally. A case of breast abscess in a 70-year-old man due to Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) is reported. The infection was successfully treated with a combination of surgical and antibiotic treatment.

Integrated combined effects of temperature, pH and sodium chloride concentration on biofilm formation by Salmonella enterica ser. Enteritidis and Typhimurium under low nutrient food-related conditions.

PubMed

Iliadis, Ioannis; Daskalopoulou, Aikaterini; Simões, Manuel; Giaouris, Efstathios

2018-05-01

Salmonella enterica is a major foodborne bacterial pathogen. This forms biofilms on surfaces and persists, depending on the strain and the environment. The integrative interaction of temperature (T; 13-39 °C), pH (5-8) and sodium chloride (NaCl) concentration (0.5-8.5%) on biofilm formation by two S. enterica strains (ser. Enteritidis and Typhimurium) was here evaluated under low nutrient conditions. This was achieved using response surface methodology to model the combined effect of each factor on the response, through mathematical quadratic fitting of the outcomes of a sequence of designed experiments. These last were executed by incubating stainless steel coupons carrying sessile bacteria, for 24 h, in 1:10 diluted tryptone soya broth, under 15 different combinations of three independent factors (T, pH and NaCl). For each strain, a second order polynomial model, describing the relationship between biofilm formation (log CFU/cm 2 ) and the factors (T, pH and NaCl), was developed using least square regression analysis. Both derived models predicted the combined influences of these factors on biofilm formation, with agreement between predictions and experimental observations (R 2  ≥ 0.96, P ≤ 0.0001). For both strains, the increase of NaCl content restricted their sessile growth, while under low salinity conditions (NaCl < 4%) biofilm formation was favored as pH increased, regardless of T. Interestingly, under low salt content, and depending on the strain, biofilm formation was either favored or hindered by increasing T. Thus, 34.5 and 13 °C were the T predicted to maximize biofilm formation by strains Enteritidis and Typhimurium, respectively, something which was also experimentally verified. To sum, these models can predict the interactive influences of crucial food-related factors on biofilm growth of a significant foodborne pathogen towards the efforts to limit its persistence in food industry. Copyright © 2018 Elsevier Ltd. All rights

Plasmid-mediated quinolone resistance in non-Typhi serotypes of Salmonella enterica.

PubMed

Gay, Kathryn; Robicsek, Ari; Strahilevitz, Jacob; Park, Chi Hye; Jacoby, George; Barrett, Timothy J; Medalla, Felicita; Chiller, Tom M; Hooper, David C

2006-08-01

Serious infections with Salmonella species are often treated with fluoroquinolones or extended-spectrum beta-lactams. Increasingly recognized in Enterobacteriaceae, plasmid-mediated quinolone resistance is encoded by qnr genes. Here, we report the presence of qnr variants in human isolates of non-Typhi serotypes of Salmonella enterica (hereafter referred to as non-Typhi Salmonella) from the United States National Antimicrobial Resistance Monitoring System for Enteric Bacteria. All non-Typhi Salmonella specimens from the United States National Antimicrobial Resistance Monitoring System for Enteric Bacteria collected from 1996 to 2003 with ciprofloxacin minimum inhibitory concentrations > or = 0.06 microg/mL (233 specimens) and a subset with minimum inhibitory concentrations < or = 0.03 microg/mL (102 specimens) were screened for all known qnr genes (A, B, and S) by polymerase chain reaction. For isolates with positive results, qnr and quinolone resistance-determining region sequences were determined. Plasmids containing qnr genes were characterized by conjugation or transformation. Conjugative plasmids harboring qnrB variants were detected in 7 Salmonella enterica serotype Berta isolates and 1 Salmonella enterica serotype Mbandaka isolate. The S. Mbandaka plasmid also had an extended-spectrum beta -lactamase. Variants of qnrS on nonconjugative plasmids were detected in isolates of Salmonella enterica serotype Anatum and Salmonella enterica serotype Bovismorbificans. Plasmid-mediated quinolone resistance appears to be widely distributed, though it is still uncommon in non-Typhi Salmonella isolates from the United States, including strains that are quinolone susceptible by the criteria of the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards). The presence of this gene in non-Typhi Salmonella that causes infection in humans suggests potential for spread through the food supply, which is a public health

Effects of methyltestosterone on immunity against Salmonella Pullorum in dwarf chicks.

PubMed

Li, H; Zhang, Y; Zuo, S F; Lian, Z X; Li, N

2009-12-01

This study was conducted to determine effects of methyltestosterone on innate immunity and adaptive immunity against Salmonella Pullorum in dwarf chicks. In vivo experiment, comparisons of pathological sections, viable counts of bacteria, specific antibody levels, and subsets of T lymphocytes were set forth between chicks with or without 10(-7) M methyltestosterone treatment (2 d of age through 21 d of age) and challenged with 5 x 10(8) virulent Salmonella Pullorum (7 d of age), and in vitro experiment, phagocytic and killing abilities, reactive oxygen intermediate production, and reactive nitrogen intermediate production of monocytes-macrophages treated with high (10(-8) M/10(6) cell) or physiological (10(-14) M/10(6) cell) concentration of methyltestosterone were examined after Salmonella Pullorum infection. The results showed that (1) in vivo, administration of methyltestosterone enhanced susceptibility to Salmonella Pullorum infection and depressed cellular immunity against Salmonella Pullorum, whereas it had no effect on humoral immunity in dwarf chicks; (2) in vitro, at high concentration, methyltestosterone reduced (P < 0.05) monocytes-macrophages mediated reactive oxygen intermediate-dependent killing of Salmonella Pullorum, whereas low concentration of methyltestosterone enhanced (P < 0.05) reactive oxygen intermediate-dependent killing of Salmonella Pullorum in male dwarf chicks but not in females; and (3) although challenged with Salmonella Pullorum, phagocytic ability and monocytes-macrophages mediated reactive nitrogen intermediate-dependent killing were not affected by methyltestosterone in vitro. The results indicated that methyltestosterone affected the immune response to Salmonella Pullorum in dwarf chicks by changing monocytes-macrophages mediated reactive oxygen intermediate-dependent killing and cellular immunity, and the effects were dose-dependent; furthermore, the former 2 pathways played important roles in preventing Salmonella Pullorum

Salmonella enterica isolated from wildlife at two Ohio rehabilitation centers.

PubMed

Jijón, Steffani; Wetzel, Amy; LeJeune, Jeffrey

2007-09-01

Between May and September 2004, fecal samples from various wildlife species admitted to two rehabilitation centers in Ohio were cultured for Salmonella enterica and Escherichia coli O157:H7. Eight of 71 (11%) samples, including specimens from three opossums (Didelphis virginiana), two gray squirrels (Sciurus carolinensis), a woodchuck (Marmota monax), a Harris hawk (Parabuteo unicinctus), and a screech owl (Otus asio) tested positive for Salmonella serovars Braenderup, Senftenberg, Oranienburg, and Kentucky. The Salmonella Oranienburg isolates were indistinguishable by pulsed-field gel electrophoresis. Most isolates were susceptible to commonly used antibiotics; however, the Salmonella Kentucky isolate was resistant to multiple beta-lactam antibiotics (amoxicillin/clavulanic acid and ampicillin), cefoxitin, and ceftiofur, a third-generation cephalosporin. Escherichia coli O157:H7 was not isolated from any sample. Transmission of Salmonella from wildlife may occur between animals at rehabilitation centers.

[Properties of Salmonella isolates in the Czech Republic].

PubMed

Srámová, H; Karpísková, R; Dĕdicová, D; Sisák, F; Rychlík, I

1999-08-01

Based on a grant project "Use and importance of epidemiological markers in Salmonella enteritidis and Salmonella typhimurium in the spread of salmonelloses in children under two years of age" implemented in 1995 to 1997, the authors investigated epidemiological markers in 1,186 salmonella isolates; the strains were isolated from faeces of 838 sick children, from 266 faeces of their contacts, from 49 specimens of incriminated foods and from 33 smears from the children's environment. Of 1,186 Salmonella isolates 999 were strains of S. enteritidis, 39 strains of S. typhimurium and 148 strains were not identified. The markers of Salmonella isolates were investigated from the aspect of biotyping--98% S. enteritidis were formed by the biovar Jena. 2% by biovar Essen; sensitivity to antibiotics--94.5% Salmonella strains were sensitive to 12 selected antibiotics, 2.9% were resistant and in 2.6% the resistance was in the intermediate zone; phagotyping--in 808 strains of S. enteritidis PT 8--88% predominated, in S. typhimurium DT 104 and DT 141; assessment of plasmid profiles--in strains of S. enteritidis plasmid 55 kb predominated, in three strains of S. typhimurium a plasmid size 95 kb; virulence--was compared in 43 strains isolated from hospitalized children with a severe clinical course with 39 strains from children treated at home. In vitro tests revealed that hospitalization of affected children was associated with virulence of the strains (SE phagotype 8) and not with age. The presented results are discussed with regard to the epidemiological situation in the Czech Republic and in the world.

Evaluation of two commercially available Salmonella vaccines on Salmonella concentration and prevalance in the peripheral lymph nodes of experimentally infected cattle

USDA-ARS?s Scientific Manuscript database

Bovine peripheral lymph nodes (PLN) may contain Salmonella, and unless contaminated nodes are removed during slaughter, they serve as a source of contamination for ground beef. Utilizing an experimental model of Salmonella inoculation of the PLN, two experiments were conducted to evaluate commercia...

Breast Abscess in a Man Due to Salmonella enterica Serotype Enteritidis

PubMed Central

Brnčić, Nada; Strčić, Miroslav; Abram, Maja; Mustač, Elvira

2012-01-01

Nontyphoidal salmonellae can cause breast infection only exceptionally. A case of breast abscess in a 70-year-old man due to Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) is reported. The infection was successfully treated with a combination of surgical and antibiotic treatment. PMID:22031702

Limitations of a localized surface plasmon resonance sensor on Salmonella detection

USDA-ARS?s Scientific Manuscript database

We have designed a localized surface plasmon resonance (LSPR) biosensor to perform the whole cell detection of Salmonella using gold nanoparticls fabricated by oblique angle deposition technique. The LSPR sensor showed a plasmon peak shift due to the Salmonella antigen and anti-Salmonella antibody r...

Electron-beam-inactivated vaccine against Salmonella enteritidis colonization in molting hens

USDA-ARS?s Scientific Manuscript database

Electron Beam (eBeam) ionization technology has a variety of applications in modern society. The underlying hypothesis was that electron beam (eBeam) inactivated Salmonella enterica serovar Enteritidis (SE) cells can serve as a vaccine to control Salmonella colonization and Salmonella shedding in c...

Inactivation of Salmonella and Listeria in ground chicken breast meat during thermal processing.

PubMed

Murphy, R Y; Marks, B P; Johnson, E R; Johnson, M G

1999-09-01

Thermal inactivation of six Salmonella spp. and Listeria innocua was evaluated in ground chicken breast and liquid medium. Survival of Salmonella and Listeria was affected by the medium composition. Under the same thermal process condition, significantly more Salmonella and Listeria survived in chicken breast meat than in 0.1% peptone-agar solution. The thermal lethality of six tested Salmonella spp. was additive in chicken meat. Survival of Listeria in chicken meat during thermal processing was not affected by the presence of the six Salmonella spp. Sample size and shape affected the inactivation of Salmonella and Listeria in chicken meat during thermal processing.

Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas

PubMed Central

Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak

2016-01-01

Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry. PMID:27499670

Household Contamination with Salmonella enterica1

PubMed Central

Hancock, Dale D.; Roozen, Paivi M.; Szymanski, Maryanne H.; Scheenstra, Beth C.; Cady, Kirsten M.; Besser, Thomas E.; Chudek, Paul A.

2003-01-01

Household contamination with Salmonella enterica increases when occupational exposure exists (cattle farms with known salmonellosis in cattle, a salmonella research laboratory, or a veterinary clinic experiencing an outbreak of salmonellosis). Fifteen of 55 (27.2%) vacuum cleaner bags from households with occupational exposure to S. enterica were positive versus 1 of 24 (4.2% without known exposure. Use of a carpet cleaner and several cleaners/disinfectants reduced, but failed to eliminate, S. enterica from artificially contaminated carpet. PMID:12533294

Occurrence and characterization of Salmonella from chicken nuggets, strips, and pelleted broiler feed.

PubMed

Bucher, O; Holley, R A; Ahmed, R; Tabor, H; Nadon, C; Ng, L K; D'Aoust, J Y

2007-10-01

Raw, frozen chicken nuggets and strips have been identified as a significant risk factor in contracting foodborne salmonellosis. Cases of salmonellosis as a result of consuming partly cooked chicken nuggets may be due in part to Salmonella strains originating in broiler feed. This study was undertaken to determine the occurrence and characterize the strains of Salmonella contaminating chicken nuggets, strips, and pelleted feeds, in an attempt to demonstrate whether the same Salmonella strains present in broiler feed could be isolated from raw, frozen chicken nuggets and strips available for human consumption. Salmonellae were recovered using the Health Canada MFHPB-20 method for the isolation and identification of Salmonella from foods. Strains were characterized by serotyping, phage typing, antimicrobial resistance typing (R-typing), and by pulsed-field gel electrophoresis (PFGE). Salmonellae were isolated from 25-g samples in 27% (n=92) of nugget and strip samples, 95% (n=20) of chicken nugget meat samples, and from 9% (n=111) of pelleted feed samples. Salmonella Heidelberg, Salmonella Enteritidis, and Salmonella Orion were the most commonly isolated serovars from chicken nuggets and strips, nugget and strip meat, and pelleted broiler feeds, respectively. Salmonella Enteritidis phage type (PT) 13a with PFGE pattern SENXAI.0006 and R-type sensitive as well as Salmonella Enteritidis PT13a with PFGE pattern SENXAI.0068 and R-type sensitive were isolated from pelleted feed, and chicken nugget and strip meat in two separate instances. Data showed that Salmonella strains isolated from broiler feed were indistinguishable from strains isolated from packaged raw, frozen chicken nuggets and strips. However, results did not rule out the possibility that breeding stock or contamination during processing may have contributed to chicken meat contamination by Salmonella.

Salmonella epidemiology: A whirlwind of change.

PubMed

Besser, John M

2018-05-01

The field of infectious disease epidemiology for Salmonella and other enteric pathogens is undergoing some of the most profound changes since the time of Kauffman and White. Rapid advances in "big data" technologies such as genomics and metagenomics are making it possible to monitor and control salmonellosis in new and exciting ways. Epidemiological methods are becoming increasingly robust through the routine use of standardized hypothesis-generating questionnaires, iterative open-ended interviewing, informational trace-backs and new modeling techniques for describing the attribution of disease to food sources. In addition, Salmonella epidemiology is facing important challenges and new opportunities due to the rapid adoption of culture independent diagnostic test panels by clinical laboratories. Where is this unprecedented wave of change taking us? This chapter will examine emerging trends in Salmonella epidemiology, and take a peek into the not-so-distant future. Published by Elsevier Ltd.

Stamping SERS for creatinine sensing

NASA Astrophysics Data System (ADS)

Li, Ming; Du, Yong; Zhao, Fusheng; Zeng, Jianbo; Santos, Greggy M.; Mohan, Chandra; Shih, Wei-Chuan

2015-03-01

Urine can be obtained easily, readily and non-invasively. The analysis of urine can provide metabolic information of the body and the condition of renal function. Creatinine is one of the major components of human urine associated with muscle metabolism. Since the content of creatinine excreted into urine is relatively constant, it is used as an internal standard to normalize water variations. Moreover, the detection of creatinine concentration in urine is important for the renal clearance test, which can monitor the filtration function of kidney and health status. In more details, kidney failure can be imminent when the creatinine concentration in urine is high. A simple device and protocol for creatinine sensing in urine samples can be valuable for point-of-care applications. We reported quantitative analysis of creatinine in urine samples by using stamping surface enhanced Raman scattering (S-SERS) technique with nanoporous gold disk (NPGD) based SERS substrate. S-SERS technique enables label-free and multiplexed molecular sensing under dry condition, while NPGD provides a robust, controllable, and high-sensitivity SERS substrate. The performance of S-SERS with NGPDs is evaluated by the detection and quantification of pure creatinine and creatinine in artificial urine within physiologically relevant concentration ranges.

Portable SERS Instrument for Explosives Monitoring

DTIC Science & Technology

2006-04-01

RDX, HMX, TNT, and TNB in UMCD groundwater…………………………………………………………………... 15 Figure 12. SERS (left) and colorimetry (right) methods set up on a...desk at ALAAP…... 20 Figure 13. SERS (left) and colorimetry (right) apparatus installed in the CPT truck…… 21 Figure 14. The Explosives Washout...for TNT in water……………………………... 29 Figure 17. Comparison of SERS and colorimetry field and laboratory results………….. 34 Figure 18. Comparison of SERS

Commercially laid eggs vs. discarded hatching eggs: contamination by Salmonella spp.

PubMed

Kottwitz, Luciana B M; Leão, Joice Aparecida; Back, Alberto; Rodrigues, Dalia dos P; Magnani, Marciane; de Oliveira, Tereza C R M

2013-01-01

Salmonella enterica is frequently associated with outbreaks of human salmonellosis, and products of avian origin, such as eggs and chicken meat, are the main vehicles of its transmission. The present study describes the occurrence of different serovars of Salmonella enterica and phagotypes of S. enterica serovar Enteritidis in eggs destined for human consumption. Four thousand eggs obtained from commercial egg laying farms and one thousand discarded hatching eggs from broiler farms, which were acquired at farmers' markets and informal shops, were analyzed. Salmonella spp. was isolated from 52.0% of the discarded hatching eggs, in which the predominant serovar was Enteritidis (84.6%), and the predominant Salmonella Enteritidis phagotype (PT) was PT7 (26.9%). Salmonella spp. was not isolated from eggs obtained from commercial egg laying farms. The antimicrobial resistance profile showed that 23.1% (n = 6) of the SE strains were resistant to nalidixic acid. The results suggest that the consumption of discarded hatching eggs represents an important source of Salmonella transmission to humans.

Prevalence of Salmonella on retail broiler chicken meat carcasses in Colombia.

PubMed

Donado-Godoy, Pilar; Clavijo, Viviana; León, Maribel; Tafur, Mc Allister; Gonzales, Sebastian; Hume, Michael; Alali, Walid; Walls, Isabel; Lo Fo Wong, Danilo M A; Doyle, M P

2012-06-01

A cross-sectional study was performed to estimate the prevalence of Salmonella on retail market chicken carcasses in Colombia. A total of 1,003 broiler chicken carcasses from 23 departments (one city per department) were collected via a stratified sampling method. Carcass rinses were tested for the presence of Salmonella by conventional culture methods. Salmonella strains were isolated from 27 % of the carcasses sampled. Logistic regression analysis was used to determine potential risk factors for Salmonella contamination associated with the chicken production system (conventional versus free-range), storage condition (chilled versus frozen), retail store type (supermarket, independent, and wet market), poultry company (integrated company versus nonintegrated company), and socioeconomic stratum. Chickens from a nonintegrated poultry company were associated with a significantly (P < 0.05) greater risk of Salmonella contamination (odds ratio, 2.0) than were chickens from an integrated company. Chilled chickens had a significantly (P < 0.05) higher risk of Salmonella contamination (odds ratio, 4.3) than did frozen chicken carcasses.

Inhibition of nalidixic acid-resistant salmonella on marinated chicken skin.

PubMed

Pathania, A; McKee, S R; Bilgili, S F; Singh, M

2010-11-01

Marination is widely used to enhance flavor and increase consumer acceptability of meat and poultry products. The impact of such marination on the safety and shelf life of poultry meat was evaluated in this study. A series of experiments were conducted to determine the efficacy of teriyaki and lemon pepper marinades against multiple strains of nalidixic acid (NAL)-resistant Salmonella. NAL-resistant Salmonella serovar (Typhimurium, Heidelberg, and Senftenberg) cultures were inoculated onto chicken skin at 0.6 to 3.14 log CFU/g in a 12-well titer plate. Inoculated chicken skin was exposed to teriyaki or lemon pepper marinades for up to 32 h and stored at 4 or 25°C to determine the prevalence of Salmonella. To determine Salmonella survival, a three-strain cocktail of Salmonella was inoculated at low (ca. 4 log CFU/g) and high (8 log CFU/g) levels onto chicken skin that was then marinated with either teriyaki or lemon pepper marinade for up to 32 h and stored at 4 or 25°C. Prevalence of Salmonella was significantly reduced (P ≤ 0.05) by teriyaki marinade at all levels of contamination regardless of storage temperature. Lemon pepper marinade reduced Salmonella prevalence (P ≤ 0.05) at low levels of contamination (10¹ and 10² CFU/g), whereas no significant effect (P > 0.05) was observed at higher levels of contamination. Marination of chicken skin with teriyaki marinade greatly reduced Salmonella prevalence and survival (P ≤ 0.05) regardless of the storage temperature, indicating the antimicrobial potential of this marinade for poultry and meat products.

Complete Genome Sequence of Salmonella enterica Serovar Typhimurium Strain YU15 (Sequence Type 19) Harboring the Salmonella Genomic Island 1 and Virulence Plasmid pSTV

PubMed Central

Calva, Edmundo; Puente, José L.; Zaidi, Mussaret B.

2016-01-01

The complete genome of Salmonella enterica subsp. enterica serovar Typhimurium sequence type 19 (ST19) strain YU15, isolated in Yucatán, Mexico, from a human baby stool culture, was determined using PacBio technology. The chromosome contains five intact prophages and the Salmonella genomic island 1 (SGI1). This strain carries the Salmonella virulence plasmid pSTV. PMID:27081132

21 CFR 866.3550 - Salmonella spp. serological reagents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Salmonella spp. serological reagents. 866.3550 Section 866.3550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella...

21 CFR 866.3550 - Salmonella spp. serological reagents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Salmonella spp. serological reagents. 866.3550 Section 866.3550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella...

21 CFR 866.3550 - Salmonella spp. serological reagents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Salmonella spp. serological reagents. 866.3550 Section 866.3550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella...

21 CFR 866.3550 - Salmonella spp. serological reagents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Salmonella spp. serological reagents. 866.3550 Section 866.3550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella...

21 CFR 866.3550 - Salmonella spp. serological reagents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Salmonella spp. serological reagents. 866.3550 Section 866.3550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella...

Orange peel products can reduce Salmonella populations in ruminants.

PubMed

Callaway, Todd R; Carroll, Jeffery A; Arthington, John D; Edrington, Tom S; Anderson, Robin C; Rossman, Michelle L; Carr, Mandy A; Genovese, Ken J; Ricke, Steve C; Crandall, Phil; Nisbet, David J

2011-10-01

Salmonella can live undetected in the gut of food animals and be transmitted to humans. Animal diets can impact intestinal populations of foodborne pathogens, including Salmonella spp. Orange juice production results in a waste product, orange peel and orange pulp, which has a high nutritive value and is often included in cattle diets as a least-cost ration ingredient. Here we show that the inclusion of orange peel products reduced Salmonella Typhimurium populations in the gut of experimentally inoculated sheep. Sheep (n=24) were fed a cracked corn grain-based high grain diet that was supplemented with a 50%/50% (dry matter [DM], w/w) mixture of dried orange pellet and fresh orange peel to achieve a final concentration (DM, basis) of 0%, 10%, or 20% orange product (OP) for 10 days before inoculation with Salmonella Typhimurium. Sheep were experimentally inoculated with 10(10) colony forming units Salmonella Typhimurium, and fecal samples were collected every 24 h after inoculation. Sheep were humanely euthanized at 96 h after oral Salmonella inoculation. Populations of inoculated Salmonella Typhimurium were numerically reduced by OP treatment throughout the gastrointestinal tract, and this reduction only reached significant levels in the cecum (p<0.05) of sheep fed 10% OP diets. Apparent palatability issues decreased the consumption of OP in sheep fed 20% OP to intake levels below that of 10% OP (approximately 7% dry matter intake [DMI]/d feed refusal), thereby reducing the potential effects of OP feeding at this higher level. Our results demonstrate that orange peel and pellets are environmentally friendly and low-cost products that can be used as a pre-harvest intervention as part of an integrated pathogen reduction scheme.

Genotypic and phenotypic characterization of multidrug resistant Salmonella Typhimurium and Salmonella Kentucky strains recovered from chicken carcasses

PubMed Central

Grant, Ar’Quette; Choi, Seon Young; Alam, M. Samiul; Bell, Rebecca; Cavanaugh, Christopher; Balan, Kannan V.; Babu, Uma S.

2017-01-01

Abstract Salmonella Typhimurium is the leading cause of human non-typhoidal gastroenteritis in the US. S. Kentucky is one the most commonly recovered serovars from commercially processed poultry carcasses. This study compared the genotypic and phenotypic properties of two Salmonella enterica strains Typhimurium (ST221_31B) and Kentucky (SK222_32B) recovered from commercially processed chicken carcasses using whole genome sequencing, phenotype characterizations and an intracellular killing assay. Illumina MiSeq platform was used for sequencing of two Salmonella genomes. Phylogenetic analysis employing homologous alignment of a 1,185 non-duplicated protein-coding gene in the Salmonella core genome demonstrated fully resolved bifurcating patterns with varying levels of diversity that separated ST221_31B and SK222_32B genomes into distinct monophyletic serovar clades. Single nucleotide polymorphism (SNP) analysis identified 2,432 (ST19) SNPs within 13 Typhimurium genomes including ST221_31B representing Sequence Type ST19 and 650 (ST152) SNPs were detected within 13 Kentucky genomes including SK222_32B representing Sequence Type ST152. In addition to serovar-specific conserved coding sequences, the genomes of ST221_31B and SK222_32B harbor several genomic regions with significant genetic differences. These included phage and phage-like elements, carbon utilization or transport operons, fimbriae operons, putative membrane associated protein-encoding genes, antibiotic resistance genes, siderophore operons, and numerous hypothetical protein-encoding genes. Phenotype microarray results demonstrated that ST221_31B is capable of utilizing certain carbon compounds more efficiently as compared to SK222_3B; namely, 1,2-propanediol, M-inositol, L-threonine, α-D-lactose, D-tagatose, adonitol, formic acid, acetoacetic acid, and L-tartaric acid. ST221_31B survived for 48 h in macrophages, while SK222_32B was mostly eliminated. Further, a 3-fold growth of ST221_31B was observed at

Genotypic and phenotypic characterization of multidrug resistant Salmonella Typhimurium and Salmonella Kentucky strains recovered from chicken carcasses.

PubMed

Tasmin, Rizwana; Hasan, Nur A; Grim, Christopher J; Grant, Ar'Quette; Choi, Seon Young; Alam, M Samiul; Bell, Rebecca; Cavanaugh, Christopher; Balan, Kannan V; Babu, Uma S; Parveen, Salina

2017-01-01

Salmonella Typhimurium is the leading cause of human non-typhoidal gastroenteritis in the US. S. Kentucky is one the most commonly recovered serovars from commercially processed poultry carcasses. This study compared the genotypic and phenotypic properties of two Salmonella enterica strains Typhimurium (ST221_31B) and Kentucky (SK222_32B) recovered from commercially processed chicken carcasses using whole genome sequencing, phenotype characterizations and an intracellular killing assay. Illumina MiSeq platform was used for sequencing of two Salmonella genomes. Phylogenetic analysis employing homologous alignment of a 1,185 non-duplicated protein-coding gene in the Salmonella core genome demonstrated fully resolved bifurcating patterns with varying levels of diversity that separated ST221_31B and SK222_32B genomes into distinct monophyletic serovar clades. Single nucleotide polymorphism (SNP) analysis identified 2,432 (ST19) SNPs within 13 Typhimurium genomes including ST221_31B representing Sequence Type ST19 and 650 (ST152) SNPs were detected within 13 Kentucky genomes including SK222_32B representing Sequence Type ST152. In addition to serovar-specific conserved coding sequences, the genomes of ST221_31B and SK222_32B harbor several genomic regions with significant genetic differences. These included phage and phage-like elements, carbon utilization or transport operons, fimbriae operons, putative membrane associated protein-encoding genes, antibiotic resistance genes, siderophore operons, and numerous hypothetical protein-encoding genes. Phenotype microarray results demonstrated that ST221_31B is capable of utilizing certain carbon compounds more efficiently as compared to SK222_3B; namely, 1,2-propanediol, M-inositol, L-threonine, α-D-lactose, D-tagatose, adonitol, formic acid, acetoacetic acid, and L-tartaric acid. ST221_31B survived for 48 h in macrophages, while SK222_32B was mostly eliminated. Further, a 3-fold growth of ST221_31B was observed at 24 hours

Prevalence and Characterization of Salmonella in Animal Meals Collected from Rendering Operations.

PubMed

Jiang, Xiuping

2016-06-01

As part of the Salmonella Education Reduction Program, the Animal Protein Producers Industry initiated a yearlong microbiological survey of animal meals from 1 January to 31 December 2010. The types of animal meals included poultry meal, pork and beef crax, meat meal, meat and bone meal, feather meal, blood meal, and fish meal from a variety of rendering operations (n = 65). Salmonella was positive in 731 (8.3%) of 8,783 analyzed samples, with contamination rates as 1.0, 33.2, and 21.3% from samples collected right after press, being loaded out, or unidentified, respectively. The randomly selected positive Salmonella samples (n = 100) representing 1.1% of the total samples tested were enumerated by the most-probable-number (MPN) method. The Salmonella contamination level ranged from <0.03 (below the detection limit) to 240 MPN/g with a median MPN per gram of 0.036. Among 102 Salmonella isolates from those 100 positive samples, a total of 42 Salmonella serotypes or groups were identified with Montevideo (13%), Senftenberg (11%), Mbandaka (7%), Orion (7%), Livingstone (6%), Tennessee (4%), Infantis (4%), Cerro (4%), and group C1 (4%) as the most predominant ones. Those Salmonella isolates were further analyzed for antimicrobial resistance to the 15 most common antibiotics by using the National Antimicrobial Resistance Monitoring System gram-negative plate. Most Salmonella isolates (n = 94) were sensitive to all antibiotics tested, with seven isolates resistant to one antibiotic and one resistant to seven antibiotics. Clearly, the prevalence of Salmonella in animal meals declined compared with previous surveys, and none of the Salmonella serotypes concerning target animal health were isolated. In addition, most Salmonella isolates remained susceptible to the majority of the 15 most commonly used antibiotics.

Immunity to intestinal pathogens: lessons learned from Salmonella

PubMed Central

McSorley, Stephen J.

2014-01-01

Summary Salmonella are a common source of food or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens. PMID:24942689

Isolation and identification of Salmonella spp. in environmental water by molecular technology in Taiwan

NASA Astrophysics Data System (ADS)

Kuo, Chun Wei; Hao Huang, Kuan; Hsu, Bing Mu; Tsai, Hsien Lung; Tseng, Shao Feng; Shen, Tsung Yu; Kao, Po Min; Shen, Shu Min; Chen, Jung Sheng

2013-04-01

Salmonella spp. is one of the most important causal agents of waterborne diseases. The taxonomy of Salmonella is very complicated and its genus comprises more than 2,500 serotypes. The detection of Salmonella in environmental water samples by routines culture methods using selective media and characterization of suspicious colonies based on biochemical tests and serological assay are generally time consuming. To overcome this drawback, it is desirable to use effective method which provides a higher discrimination and more rapid identification about Salmonella in environmental water. The aim of this study is to investigate the occurrence of Salmonella using molecular technology and to identify the serovars of Salmonella isolates from 70 environmental water samples in Taiwan. The analytical procedures include membrane filtration, non-selective pre-enrichment, selective enrichment of Salmonella. After that, we isolated Salmonella strains by selective culture plates. Both selective enrichment and culture plates were detected by Polymerase Chain Reaction (PCR). Finally, the serovars of Salmonella were confirmed by using biochemical tests and serological assay. In this study, 15 water samples (21.4%) were identified as Salmonella by PCR. The positive water samples will further identify their serotypes by culture method. The presence of Salmonella in environmental water indicates the possibility of waterborne transmission in drinking watershed. Consequently, the authorities need to provide sufficient source protection and to maintain the system for disease prevention. Keywords: Salmonella spp., serological assay, PCR

Comparative performance of three sampling techniques to detect airborne Salmonella species in poultry farms.

PubMed

Adell, Elisa; Moset, Verónica; Zhao, Yang; Jiménez-Belenguer, Ana; Cerisuelo, Alba; Cambra-López, María

2014-01-01

Sampling techniques to detect airborne Salmonella species (spp.) in two pilot scale broiler houses were compared. Broilers were inoculated at seven days of age with a marked strain of Salmonella enteritidis. The rearing cycle lasted 42 days during the summer. Airborne Salmonella spp. were sampled weekly using impaction, gravitational settling, and impingement techniques. Additionally, Salmonella spp. were sampled on feeders, drinkers, walls, and in the litter. Environmental conditions (temperature, relative humidity, and airborne particulate matter (PM) concentration) were monitored during the rearing cycle. The presence of Salmonella spp. was determined by culture-dependent and molecular methods. No cultivable Salmonella spp. were recovered from the poultry houses' surfaces, the litter, or the air before inoculation. After inoculation, cultivable Salmonella spp. were recovered from the surfaces and in the litter. Airborne cultivable Salmonella spp. Were detected using impaction and gravitational settling one or two weeks after the detection of Salmonella spp. in the litter. No cultivable Salmonella spp. were recovered using impingement based on culture-dependent techniques. At low airborne concentrations, the use of impingement for the quantification or detection of cultivable airborne Salmonella spp. is not recommended. In these cases, a combination of culture-dependent and culture-independent methods is recommended. These data are valuable to improve current measures to control the transmission of pathogens in livestock environments and for optimising the sampling and detection of airborne Salmonella spp. in practical conditions.

Detection of Salmonella bacterium in drinking water using microring resonator.

PubMed

Bahadoran, Mahdi; Noorden, Ahmad Fakhrurrazi Ahmad; Mohajer, Faeze Sadat; Abd Mubin, Mohamad Helmi; Chaudhary, Kashif; Jalil, Muhammad Arif; Ali, Jalil; Yupapin, Preecha

2016-01-01

A new microring resonator system is proposed for the detection of the Salmonella bacterium in drinking water, which is made up of SiO2-TiO2 waveguide embedded inside thin film layer of the flagellin. The change in refractive index due to the binding of the Salmonella bacterium with flagellin layer causes a shift in the output signal wavelength and the variation in through and drop port's intensities, which leads to the detection of Salmonella bacterium in drinking water. The sensitivity of proposed sensor for detecting of Salmonella bacterium in water solution is 149 nm/RIU and the limit of detection is 7 × 10(-4)RIU.

75 FR 66769 - Draft Compliance Policy Guide Sec. 690.800 Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-29

...] Draft Compliance Policy Guide Sec. 690.800 Salmonella in Animal Feed; Availability; Extension of Comment... that are adulterated due to the presence of Salmonella. The Agency is taking this action in response to... action against animal feed or feed ingredients that are adulterated due to the presence of Salmonella...

Influence of phosphorylation of THR-3, SER-11, and SER-15 on deoxycytidine kinase activity and stability.

PubMed

Smal, C; Ntamashimikiro, S; Arts, A; Van Den Neste, E; Bontemps, F

2010-06-01

Deoxycytidine kinase (dCK) is a key enzyme in the salvage of deoxyribonucleosides and in the activation of several anticancer and antiviral nucleoside analogues. We have recently shown that dCK is a phosphoprotein. Four in vivo phosphorylation sites were identified: Thr-3, Ser-11, Ser-15, and Ser-74. Site-directed mutagenesis demonstrated that phosphorylation of Ser-74, the major phosphorylated residue, strongly influences dCK activity in eucaryotic cells. Here, we show that phosphorylation of the three other sites, located in the N-terminal extremity of the protein, does not significantly modify dCK activity, but phosphorylation of Thr-3 could promote dCK stability.

Salmonella Typhimurium and Salmonella Sofia: Growth in and Persistence on Eggs under Production and Retail Conditions

PubMed Central

McAuley, Catherine M.; Duffy, Lesley L.; Subasinghe, Nela; Hogg, Geoff; Coventry, John; Fegan, Narelle

2015-01-01

Salmonellosis in Australia has been linked to eggs and egg products with specific serotypes associated with outbreaks. We compared attachment to and survival on egg shells and growth in eggs of two Salmonella serotypes, an egg outbreak associated Salmonella Typhimurium and a non-egg-associated Salmonella enterica ssp. II 1,4,12,27:b:[e,n,x] (S. Sofia). Experiments were conducted at combinations of 4, 15, 22, 37 and 42°C. No significant differences occurred between the serotypes in maximum growth rates, which were significantly greater (P < 0.001) in egg yolk (0.427 log10 CFU/mL/h) compared to whole egg (0.312 log10 CFU/mL/h) and egg white (0.029 log10 CFU/mL/h). Attachment to egg shells varied by time (1 or 20 min) and temperature (4, 22 and 42°C), with S. Typhimurium isolates attaching at higher levels (P < 0.05) than S. Sofia after 1 min at 4°C and S. Typhimurium ATCC 14028 attaching at higher (P < 0.05) levels at 22°C. Survival on egg shells was not significantly different across isolates. Salmonella serotypes behaved similarly regarding growth in egg contents, attachment to egg shells and survival on eggs, indicating that other factors more likely contributed to reasons for S. Typhimurium being implicated in multiple egg-associated outbreaks. PMID:26539536

Detection and classification of salmonella serotypes using spectral signatures collected by fourier transform infrared (FT-IR) spectroscopy

USDA-ARS?s Scientific Manuscript database

Spectral signatures of Salmonella serotypes namely Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky were collected using Fourier transform infrared spectroscopy (FT-IR). About 5-10 µL of Salmonella suspensions with concentrations of 1...

Characterization and Antimicrobial Resistance of Salmonella Typhimurium Isolates from Clinically Diseased Pigs in Korea.

PubMed

Oh, Sang-Ik; Kim, Jong Wan; Chae, Myeongju; Jung, Ji-A; So, Byungjae; Kim, Bumseok; Kim, Ha-Young

2016-11-01

This study investigated the prevalence of Salmonella enterica serovar and antimicrobial resistance in Salmonella Typhimurium isolates from clinically diseased pigs collected from 2008 to 2014 in Korea. Isolates were also characterized according to the presence of antimicrobial resistance genes and pulsed-field gel electrophoresis patterns. Among 94 Salmonella isolates, 81 (86.2%) were identified as being of the Salmonella Typhimurium serotype, followed by Salmonella Derby (6 of 94, 6.4%), Salmonella 4,[5],12:i:- (4 of 94, 4.3%), Salmonella Enteritidis (2 of 94, 2.1%), and Salmonella Brandenburg (1 of 94, 1.1%). The majority of Salmonella Typhimurium isolates were resistant to tetracycline (92.6%), followed by streptomycin (88.9%) and ampicillin (80.2%). Overall, 96.3% of Salmonella Typhimurium isolates showed multidrug-resistant phenotypes and commonly harbored the resistance genes bla TEM (64.9%), flo (32.8%), aadA (55.3%), strA (58.5%), strB (58.5%), sulII (53.2%), and tetA (61.7%). The pulsed-field gel electrophoresis analysis of 45 Salmonella Typhimurium isolates from individual farms revealed 27 distinct patterns that formed one major and two minor clusters in the dendrogram analysis, suggesting that most of the isolates (91.1%) from diseased pigs were genetically related. These findings can assist veterinarians in the selection of appropriate antimicrobial agents to combat Salmonella Typhimurium infections in pigs. Furthermore, they highlight the importance of continuous surveillance of antimicrobial resistance and genetic status in Salmonella Typhimurium for the detection of emerging resistance trends.

Injury and death of various Salmonella serotypes due to acidic conditions

USDA-ARS?s Scientific Manuscript database

Acid injury of Salmonella could prevent detection of Salmonella in feed and feed-type samples. A previous study showed that after incubation in commonly used pre-enrichment media, mixed feeds and feed ingredients reached a pH (4.0 to 5.0) capable of injuring or killing Salmonella. Approximately 10...

Salmonella serovar-specific interaction with jejunal epithelial cells.

PubMed

Razzuoli, Elisabetta; Amadori, Massimo; Lazzara, Fabrizio; Bilato, Dania; Ferraris, Monica; Vito, Guendalina; Ferrari, Angelo

2017-08-01

Gut is often a receptacle for many different pathogens in feed and/or the environment, such as Salmonella spp. The current knowledge about pathogenicity of Salmonella is restricted to few serotypes, whereas other important ones like S. Coeln, S. Thompson, S. Veneziana, have not been investigated yet in human and animal models. Therefore, the aim of our work was to verify the ability of widespread environmental Salmonella strains to penetrate and modulate innate immunity in pig intestinal IPEC-J2 cells. Our results outline the different ability of Salmonella strains to modulate innate immunity; the expression of the IFN-β gene was increased by S. Typhimurium, S. Ablogame and S. Diarizonae 2, that also caused an inflammatory response in terms of Interleukin (IL)-1β and/or IL-8 gene espression. In particular, IL-8 gene expression and protein release were significantly modulated by 5 Salmonella strains out of 7. Interestingly, S. Typhimurium, S. Coeln and S. Thompson strains, characterized by a peculiar ability to penetrate into IPEC-J2 cells, up-regulated both IL-8 and TNF-α gene expression. Accordingly, blocking IL-8 was shown to decrease the penetration of S. Typhimurium. On the contrary, S. Diarizonae strain 1, showing lesser invasion of IPEC-J2 cells, down-regulated the p38-MAPK pathway, and it did not induce an inflammatory response. Our results confirm that IPEC-J2 cells are a useful model to evaluate host-gut pathogen interaction and indicate IL-8 and TNF-α as possible predictive markers of invasiveness of Salmonella strains in enterocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

Salmonella Urinary Tract Infection Heralding Thoracic Mycotic Aneurysm: Case Report as Medical Apology

PubMed Central

White, Jennifer L.; Golfus, Gabriel R.; Sadosty, Annie T.

2017-01-01

We report a case as a patient apology as a means of teaching other physicians about a unique presentation of a rare disease. Salmonella species are unusually isolated organisms in urine. In the case described, appreciation for the rarity of Salmonella species in the urine facilitated recognition of a serious disseminated Salmonella infection. Physicians should consider disseminated Salmonella infection, as was found in a patient with an aortic mycotic an eurysm, after isolation of Salmonella in urine despite an initially benign clinical presentation.

Fasting mediated increase in p-BAD(ser155) and p-AKT(ser473) in the prefrontal cortex of mice.

PubMed

Pitchaimani, Vigneshwaran; Arumugam, Somasundaram; Thandavarayan, Rajarajan Amirthalingam; Karuppagounder, Vengadeshprabhu; Sreedhar, Remya; Afrin, Rejina; Harima, Meilei; Suzuki, Hiroshi; Miyashita, Shizuka; Nomoto, Mayumi; Sone, Hirohito; Suzuki, Kenji; Watanabe, Kenichi

2014-09-05

BAD-deficient mice and fasting have several common functional roles in seizures, beta-hydroxybutyrate (BHB) uptake in brain and alteration in counterregulatory hormonal regulation during hypoglycemia. Neuronal specific insulin receptor knockout (NIRKO) mice display impaired counterregulatory hormonal responses during hypoglycemia. In this study we investigated the fasting mediated expression of p-BAD(ser155) and p-AKT(ser473) in different regions of brain (prefrontal cortex, hippocampus, midbrain and hypothalamus). Fasting specifically increases p-BAD(ser155) and p-AKT(ser473) in prefrontal cortex and decreases in other regions of brain. Our results suggest that fasting may increase the uptake BHB by decreasing p-BAD(ser155) in the brain during hypoglycemia except prefrontal cortex and it uncovers specific functional area of p-BAD(ser155) and p-AKT(ser473) that may regulates counter regulatory hormonal response. Overall in support with previous findings, fasting mediated hypoglycemia activates prefrontal cortex insulin signaling which influences the hypothalamic paraventricular nucleus mediated activation of sympathoadrenal hormonal responses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effect of dietary supplementation of nitrocompounds on salmonella colonization and ileal immune gene expression in laying hens challenged with salmonella enteritidis

USDA-ARS?s Scientific Manuscript database

Foodborne disease caused by Salmonella Enteritidis (SE) is one of the important public health and economic concerns. A study was conducted to determine the effect of supplementation with 2-nitroethanol (NE) and 2-nitropropanol (NP) on Salmonella recovery of internal organs as well as on the immune g...

Use of enrichment real-time PCR to enumerate salmonella on chicken parts.

PubMed

Oscar, T P

2014-07-01

Salmonella bacteria that survive cooking or that cross-contaminate other food during meal preparation and serving represent primary routes of consumer exposure to this pathogen from chicken. In the present study, enrichment real-time PCR (qPCR) was used to enumerate Salmonella bacteria that contaminate raw chicken parts at retail or that cross-contaminate cooked chicken during simulated meal preparation and serving. Whole raw chickens obtained at retail were partitioned into wings, breasts, thighs, and drumsticks using a sterilized knife and cutting board, which were then used to partition a cooked chicken breast to assess cross-contamination. After enrichment in buffered peptone water (400 ml, 8 h, 40°C, 80 rpm), subsamples were used for qPCR and cultural isolation of Salmonella. In some experiments, chicken parts were spiked with 0 to 3.6 log of Salmonella Typhimurium var. 5- to generate a standard curve for enumeration by qPCR. Of 10 raw chickens examined, 7 (70%) had one or more parts contaminated with Salmonella. Of 80 raw parts examined, 15 (19%) were contaminated with Salmonella. Of 20 cooked chicken parts examined, 2 (10%) were cross-contaminated with Salmonella. Predominant serotypes identified were Typhimurium (71%) and its variants (var. 5-, monophasic, and nonmotile) and Kentucky (18%). The number of Salmonella bacteria on contaminated parts ranged from one to two per part. Results of this study indicated that retail chicken parts examined were contaminated with low levels of Salmonella, which resulted in low levels of cross-contamination during simulated meal preparation and serving. Thus, if consumers properly handle and prepare the chicken, it should pose no or very low risk of consumer exposure to Salmonella.

Real-Time PCR Method for Detection of Salmonella spp. in Environmental Samples.

PubMed

Kasturi, Kuppuswamy N; Drgon, Tomas

2017-07-15

The methods currently used for detecting Salmonella in environmental samples require 2 days to produce results and have limited sensitivity. Here, we describe the development and validation of a real-time PCR Salmonella screening method that produces results in 18 to 24 h. Primers and probes specific to the gene invA , group D, and Salmonella enterica serovar Enteritidis organisms were designed and evaluated for inclusivity and exclusivity using a panel of 329 Salmonella isolates representing 126 serovars and 22 non- Salmonella organisms. The invA - and group D-specific sets identified all the isolates accurately. The PCR method had 100% inclusivity and detected 1 to 2 copies of Salmonella DNA per reaction. Primers specific for Salmonella -differentiating fragment 1 (Sdf-1) in conjunction with the group D set had 100% inclusivity for 32 S Enteritidis isolates and 100% exclusivity for the 297 non-Enteritidis Salmonella isolates. Single-laboratory validation performed on 1,741 environmental samples demonstrated that the PCR method detected 55% more positives than the V itek i mmuno d iagnostic a ssay s ystem (VIDAS) method. The PCR results correlated well with the culture results, and the method did not report any false-negative results. The receiver operating characteristic (ROC) analysis documented excellent agreement between the results from the culture and PCR methods (area under the curve, 0.90; 95% confidence interval of 0.76 to 1.0) confirming the validity of the PCR method. IMPORTANCE This validated PCR method detects 55% more positives for Salmonella in half the time required for the reference method, VIDAS. The validated PCR method will help to strengthen public health efforts through rapid screening of Salmonella spp. in environmental samples.

Real-Time PCR Method for Detection of Salmonella spp. in Environmental Samples

PubMed Central

Drgon, Tomas

2017-01-01

ABSTRACT The methods currently used for detecting Salmonella in environmental samples require 2 days to produce results and have limited sensitivity. Here, we describe the development and validation of a real-time PCR Salmonella screening method that produces results in 18 to 24 h. Primers and probes specific to the gene invA, group D, and Salmonella enterica serovar Enteritidis organisms were designed and evaluated for inclusivity and exclusivity using a panel of 329 Salmonella isolates representing 126 serovars and 22 non-Salmonella organisms. The invA- and group D-specific sets identified all the isolates accurately. The PCR method had 100% inclusivity and detected 1 to 2 copies of Salmonella DNA per reaction. Primers specific for Salmonella-differentiating fragment 1 (Sdf-1) in conjunction with the group D set had 100% inclusivity for 32 S. Enteritidis isolates and 100% exclusivity for the 297 non-Enteritidis Salmonella isolates. Single-laboratory validation performed on 1,741 environmental samples demonstrated that the PCR method detected 55% more positives than the Vitek immunodiagnostic assay system (VIDAS) method. The PCR results correlated well with the culture results, and the method did not report any false-negative results. The receiver operating characteristic (ROC) analysis documented excellent agreement between the results from the culture and PCR methods (area under the curve, 0.90; 95% confidence interval of 0.76 to 1.0) confirming the validity of the PCR method. IMPORTANCE This validated PCR method detects 55% more positives for Salmonella in half the time required for the reference method, VIDAS. The validated PCR method will help to strengthen public health efforts through rapid screening of Salmonella spp. in environmental samples. PMID:28500041

Prevalence of Salmonella on raw poultry at retail markets in China.

PubMed

Yang, Baowei; Xi, Meili; Wang, Xin; Cui, Shenghui; Yue, Tianli; Hao, Hongshan; Wang, Yin; Cui, Yue; Alali, W Q; Meng, Jianghong; Walls, Isabel; Wong, D M Lo Fo; Doyle, M P

2011-10-01

Data regarding Salmonella on raw poultry are very limited in China. The objective of this study was to determine the prevalence of Salmonella on raw poultry at the retail level in six provinces and two national cities in China. Whole chicken carcasses (n = 1,152) were collected from three types of retail markets (large, small, and wet). All samples were analyzed for the presence of Salmonella by using the U.S. Department of Agriculture, Food Safety Inspection Service method. Of 1,152 chicken samples, overall Salmonella prevalence was 52.2%. The highest prevalence was observed in Guangxi Province (65.3%), next in Guangdong Province (64.6%), and then in Beijing (63.9%), Shaanxi Province (50.7%), Henan Province (47.9%), Shanghai (44.4%), and Fujian Province (42.4%), and lowest prevalence was observed in Sichuan Province (38.9%). Salmonella prevalence was significantly different among the six provinces and two national cities. Salmonella prevalence was highest in the wet markets (54.4%) compared with the large markets (50.3%) and the small markets (52.1%), but differences were not significant (P > 0.05). Good manufacturing practices, good agricultural practices, and hazard analysis critical control point systems for Salmonella control in poultry production at the farm, processing, and retail level should be implemented.

Prevalence of Salmonella in the broiler supply chain in The Netherlands.

PubMed

Van Der Fels-Klerx, H J; Jacobs-Reitsma, W F; Van Brakel, R; Van Der Voet, H; Van Asselt, E D

2008-10-01

This article presents detailed information on Salmonella prevalence throughout the broiler supply chain in The Netherlands, based on results from a national monitoring program. Data were collected during the period 2002 through 2005 and from six sampling points in the chain, covering hatchery up to and including processing. Trends in Salmonella prevalence over years and seasons were analyzed as well as the effect of slaughterhouse capacity on these trends. In addition, correlations between the occurrence of Salmonella at the various sampling points were calculated. The results showed a decreasing trend of Salmonella prevalence from 2002 through 2005 at all sampling points. A seasonal effect on the occurrence of Salmonella was found at the broiler farm, with a higher prevalence during the third and fourth quarter of the year (July through December). The higher the capacity of the slaughterhouse, the lower Salmonella prevalence on arrival at the slaughterhouse and the higher the prevalence at the end of slaughter and the end of processing. The detailed insights obtained in this study could be used to focus future field and experimental research on the prevention and control of Salmonella in the broiler supply chain. Results presented could also be used in risk assessment studies.

Foodborne Salmonella control

USDA-ARS?s Scientific Manuscript database

Almost all of the paratyphoid Salmonella spp. are normal flora bacteria of the intestines of chickens and turkeys. They cohabit together and have a very comfortable living arrangement, causing little or no harm to one another and seldom attracting much attention from the birds’ defense systems. Th...

Rodents as a Source of Salmonella Contamination in Wet Markets in Thailand.

PubMed

Ribas, Alexis; Saijuntha, Weerachai; Agatsuma, Takeshi; Prantlová, Veronika; Poonlaphdecha, Srisupaph

2016-08-01

Few studies have been conducted on the presence of Salmonella in the rodents that inhabit the wet markets that play an important role in daily life in Southeast Asia. The results of studies of rodents as carriers of Salmonella vary greatly, ranging from an absence of Salmonella to high prevalences. Previous studies investigated habitats such as farms and urban and wild areas where there is less rodent-human interaction than in wet markets. Consequently, the potential role of rodents as reservoirs and transmitters of Salmonella in wet markets is of great interest. Rodents were trapped in eight traditional wet markets in Thailand and identified to species level. Subsequently, they were screened for Salmonella and isolates were serotyped. A total of 110 rats (Rattus norvegicus and Rattus exulans) were examined. Overall, the prevalence of Salmonella in rats was 49.10%, but varied between 0% and 73.3% among markets. Three serovars were identified: Salmonella Typhimurium (30%), S. Weltevreden (12.7%), and S. 4,[5],12:i:- (6.4%). Our results show that rodents in wet markets are a potential reservoir of Salmonella due to the close contact they have with humans and food. The three isolated serovars, of which serovar S. 4,[5],12:i:- is reported for the first time in rodents, are among the 10 commonest serovars isolated from humans in Thailand. Thus, more attention should be paid to rodents as potential reservoirs of Salmonella.

Reduction of Salmonella in skinless chicken breast fillets by lauric arginate surface application.

PubMed

Sharma, C S; Ates, A; Joseph, P; Nannapaneni, R; Kiess, A

2013-05-01

Lauric arginate (LAE) has been found to be effective against various foodborne pathogens. In this study, the antimicrobial efficacy of LAE against Salmonella and mesophilic organisms was evaluated in fresh, skinless, boneless, uncooked chicken breast fillets. The effect of LAE treatments on pH and color of breast fillets was also assessed. Chicken breast fillets were inoculated with a 4-strain Salmonella cocktail (Salmonella Enteritidis ATCC 4931, Salmonella Heidelberg ATCC 8326, Salmonella Kentucky ATCC 9263, and Salmonella Typhimurium ATCC 14028) and then treated with sterile dionized water (positive control) and 200 ppm and 400 ppm of LAE. The chicken breast fillets were stored at 4 ± 1°C and analyzed on d 0, 1, 3, 5, and 7 for Salmonella, total aerobes, color, and pH. The fillets destined for color analysis were not inoculated with Salmonella cocktail and stored under conditions simulating the retail display. The fillets treated with 400 ppm LAE had lower (P < 0.05) Salmonella counts compared with the positive control from d 0 through d 7 of storage except on d 3, when no effect of LAE was observed. Treating fillets with 200 ppm of LAE caused a significant reduction in Salmonella counts (P < 0.1) on d 0, 1, and 7. Reductions in Salmonella spp. were 0.7 log cfu/g and 0.7 to 1.0 log cfu/g for 200 and 400 ppm treatments, respectively. Lauric arginate did not exhibit any treatment effect on the growth of mesophilic microorganisms, pH, and color of chicken breast fillets (P > 0.05) when applied at 200 and 400 ppm concentrations. These results indicate that surface application of LAE in chicken breast fillets significantly reduces Salmonella during refrigerated aerobic storage without negatively affecting the color of chicken breast fillets.

SER 1, ENVIRONMENTAL ABSTRACTS. SER, SCHOOL ENVIRONMENTS RESEARCH.

ERIC Educational Resources Information Center

HIMES, HAROLD W.

THIS, A COLLECTION OF SOME 600 LENGTHY ABSTRACTS FROM THE LITERATURE OF ENVIRONMENTAL RELATIONSHIPS, IS THE FIRST IN WHAT IS TO BE A LONG SERIES OF SER PROJECT REPORTS. IT IS ORGANIZED UNDER HEADINGS THAT INDICATE THE EFFECT OF ENVIRONMENT ON THE HUMAN SENSES, AND THE EFFECTS OF ATMOSPHERIC, LUMINOUS, SONIC, AND SOCIAL ENVIRONMENTS ON BEHAVIOR.…

Plasmonic nanostructures for bioanalytical applications of SERS

NASA Astrophysics Data System (ADS)

Kahraman, Mehmet; Wachsmann-Hogiu, Sebastian

2016-03-01

Surface-enhanced Raman scattering (SERS) is a potential analytical technique for the detection and identification of chemicals and biological molecules and structures in the close vicinity of metallic nanostructures. We present a novel method to fabricate tunable plasmonic nanostructures and perform a comprehensive structural and optical characterization of the structures. Spherical latex particles are uniformly deposited on glass slides and used as templates to obtain nanovoid structures on polydimethylsiloxane surfaces. The diameter and depth of the nanovoids are controlled by the size of the latex particles. The nanovoids are coated with a thin Ag layer for fabrication of uniform plasmonic nanostructures. Structural characterization of the surfaces is performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Optical properties of these plasmonic nanostructures are evaluated via UV/Vis spectroscopy, and SERS. The sample preparation step is the key point to obtain strong and reproducible SERS spectra from the biological structures. When the colloidal suspension is used as a SERS substrate for the protein detection, the electrostatic interaction of the proteins with the nanoparticles is described by the nature of their charge status, which influences the aggregation properties such as the size and shape of the aggregates, which is critical for the SERS experiment. However, when the solid SERS substrates are fabricated, SERS signal of the proteins that are background free and independent of the protein charge. Pros and cons of using plasmonic nano colloids and nanostructures as SERS substrate will be discussed for label-free detection of proteins using SERS.

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

PubMed Central

Gole, Vaibhav C.; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret

2016-01-01

ABSTRACT The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates (n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA, ironA, and misL. There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems.

PubMed

Gole, Vaibhav C; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret; Chousalkar, Kapil

2017-03-01

The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates ( n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA , ironA , and misL There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella serovars in

Diversification of the Salmonella Fimbriae: A Model of Macro- and Microevolution

PubMed Central

Yue, Min; Rankin, Shelley C.; Blanchet, Ryan T.; Nulton, James D.; Edwards, Robert A.; Schifferli, Dieter M.

2012-01-01

Bacteria of the genus Salmonella comprise a large and evolutionary related population of zoonotic pathogens that can infect mammals, including humans and domestic animals, birds, reptiles and amphibians. Salmonella carries a plethora of virulence genes, including fimbrial adhesins, some of them known to participate in mammalian or avian host colonization. Each type of fimbria has its structural subunit and biogenesis genes encoded by one fimbrial gene cluster (FGC). The accumulation of new genomic information offered a timely opportunity to better evaluate the number and types of FGCs in the Salmonella pangenome, to test the use of current classifications based on phylogeny, and to infer potential correlations between FGC evolution in various Salmonella serovars and host niches. This study focused on the FGCs of the currently deciphered 90 genomes and 60 plasmids of Salmonella. The analysis highlighted a fimbriome consisting of 35 different FGCs, of which 16 were new, each strain carrying between 5 and 14 FGCs. The Salmonella fimbriome was extremely diverse with FGC representatives in 8 out of 9 previously categorized fimbrial clades and subclades. Phylogenetic analysis of Salmonella suggested macroevolutionary shifts detectable by extensive FGC deletion and acquisition. In addition, microevolutionary drifts were best depicted by the high level of allelic variation in predicted or known adhesins, such as the type 1 fimbrial adhesin FimH for which 67 different natural alleles were identified in S. enterica subsp. I. Together with strain-specific collections of FGCs, allelic variation among adhesins attested to the pathoadaptive evolution of Salmonella towards specific hosts and tissues, potentially modulating host range, strain virulence, disease progression, and transmission efficiency. Further understanding of how each Salmonella strain utilizes its panel of FGCs and specific adhesin alleles for survival and infection will support the development of new approaches

Salmonella serovars and their distribution in Nigerian commercial chicken layer farms

PubMed Central

Fagbamila, Idowu Oluwabunmi; Barco, Lisa; Mancin, Marzia; Kwaga, Jacob; Ngulukun, Sati Samuel; Zavagnin, Paola; Lettini, Antonia Anna; Lorenzetto, Monica; Abdu, Paul Ayuba; Kabir, Junaidu; Umoh, Jarlath; Ricci, Antonia; Muhammad, Maryam

2017-01-01

Commercial poultry farms (n° 523), located in all the six regions of Nigeria were sampled with a view to generate baseline information about the distribution of Salmonella serovars in this country. Five different matrices (litter, dust, faeces, feed and water) were collected from each visited farm. Salmonella was isolated from at least one of the five matrices in 228 farms, with a farm prevalence of 43.6% (CI95[39.7–48.3%]). Altogether, 370 of 2615 samples collected (14.1%, CI95[12.8; 15.5%]) contained Salmonella. Considering the number of positive farms and the number of positive samples, it was evident that for the majority of the sampled farms, few samples were positive for Salmonella. With regard to the matrices, there was no difference in Salmonella prevalence among the five matrices considered. Of the 370 isolates serotyped, eighty-two different serotypes were identified and Salmonella Kentucky was identified as having the highest isolation rate in all the matrices sampled (16.2%), followed by S. Poona and S. Elisabethville. S. Kentucky was distributed across the country, whereas the other less frequent serovars had a more circumscribed diffusion. This is one of few comprehensive studies on the occurrence and distribution of Salmonella in commercial chicken layer farms from all the six regions of Nigeria. The relatively high prevalence rate documented in this study may be attributed to the generally poor infrastructure and low biosecurity measures in controlling stray animals, rodents and humans. Data collected could be valuable for instituting effective intervention strategies for Salmonella control in Nigeria and also in other developing countries with a similar poultry industry structure, with the final aim of reducing Salmonella spread in animals and ultimately in humans. PMID:28278292

Salmonella serovars and their distribution in Nigerian commercial chicken layer farms.

PubMed

Fagbamila, Idowu Oluwabunmi; Barco, Lisa; Mancin, Marzia; Kwaga, Jacob; Ngulukun, Sati Samuel; Zavagnin, Paola; Lettini, Antonia Anna; Lorenzetto, Monica; Abdu, Paul Ayuba; Kabir, Junaidu; Umoh, Jarlath; Ricci, Antonia; Muhammad, Maryam

2017-01-01

Commercial poultry farms (n° 523), located in all the six regions of Nigeria were sampled with a view to generate baseline information about the distribution of Salmonella serovars in this country. Five different matrices (litter, dust, faeces, feed and water) were collected from each visited farm. Salmonella was isolated from at least one of the five matrices in 228 farms, with a farm prevalence of 43.6% (CI95[39.7-48.3%]). Altogether, 370 of 2615 samples collected (14.1%, CI95[12.8; 15.5%]) contained Salmonella. Considering the number of positive farms and the number of positive samples, it was evident that for the majority of the sampled farms, few samples were positive for Salmonella. With regard to the matrices, there was no difference in Salmonella prevalence among the five matrices considered. Of the 370 isolates serotyped, eighty-two different serotypes were identified and Salmonella Kentucky was identified as having the highest isolation rate in all the matrices sampled (16.2%), followed by S. Poona and S. Elisabethville. S. Kentucky was distributed across the country, whereas the other less frequent serovars had a more circumscribed diffusion. This is one of few comprehensive studies on the occurrence and distribution of Salmonella in commercial chicken layer farms from all the six regions of Nigeria. The relatively high prevalence rate documented in this study may be attributed to the generally poor infrastructure and low biosecurity measures in controlling stray animals, rodents and humans. Data collected could be valuable for instituting effective intervention strategies for Salmonella control in Nigeria and also in other developing countries with a similar poultry industry structure, with the final aim of reducing Salmonella spread in animals and ultimately in humans.

Prevalence and Spatial Distribution of Salmonella Infections in the Pennsylvania Raccoon (Procyon lotor).

PubMed

Very, K J; Kirchner, M K; Shariat, N; Cottrell, W; Sandt, C H; Dudley, E G; Kariyawasam, S; Jayarao, B M

2016-05-01

A study was conducted to determine the prevalence and spatial distribution of Salmonella infection in Pennsylvania raccoons (Procyon lotor), common wildlife mammals known to occupy overlapping habitats with humans and domestic food animals. The Pennsylvania Game Commission provided a total of 371 raccoon intestinal samples from trapped and road-killed raccoons collected between May and November 2011. Salmonella was isolated from the faeces of 56 (15.1%) of 371 raccoons in 35 (54%) of 65 counties across Pennsylvania. The five most frequently isolated serotypes were Newport (28.6%), Enteritidis (19.6%), Typhimurium (10.7%), Braenderup (8.9%) and Bareilly (7.1%). Pulsed-field gel electrophoresis (PFGE) analysis of the Salmonella isolates and subsequent comparison to the Pennsylvania Department of Health human Salmonella PFGE database revealed 16 different pulsetypes in Salmonella isolates recovered from raccoons that were indistinguishable from pulsetypes of Salmonella collected from clinically ill humans during the study period. The pulsetypes of seven raccoon Salmonella isolates matched those of 56 human Salmonella isolates by month and geographical region of sample collection. Results from Clustered Regularly Interspaced Short Palindromic Repeats and Multi-Virulence Locus Sequence Typing (CRISPR-MVLST) analysis corroborated the PFGE and serotyping data. The findings of this study show that several PFGE pulsetypes of Salmonella were shared between humans and raccoons in Pennsylvania, indicating that raccoons and humans might share the same source of Salmonella. © 2015 Blackwell Verlag GmbH.

Achieving optimal SERS through enhanced experimental design

PubMed Central

Fisk, Heidi; Westley, Chloe; Turner, Nicholas J.

2016-01-01

One of the current limitations surrounding surface‐enhanced Raman scattering (SERS) is the perceived lack of reproducibility. SERS is indeed challenging, and for analyte detection, it is vital that the analyte interacts with the metal surface. However, as this is analyte dependent, there is not a single set of SERS conditions that are universal. This means that experimental optimisation for optimum SERS response is vital. Most researchers optimise one factor at a time, where a single parameter is altered first before going onto optimise the next. This is a very inefficient way of searching the experimental landscape. In this review, we explore the use of more powerful multivariate approaches to SERS experimental optimisation based on design of experiments and evolutionary computational methods. We particularly focus on colloidal‐based SERS rather than thin film preparations as a result of their popularity. © 2015 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons, Ltd. PMID:27587905

Achieving optimal SERS through enhanced experimental design.

PubMed

Fisk, Heidi; Westley, Chloe; Turner, Nicholas J; Goodacre, Royston

2016-01-01

One of the current limitations surrounding surface-enhanced Raman scattering (SERS) is the perceived lack of reproducibility. SERS is indeed challenging, and for analyte detection, it is vital that the analyte interacts with the metal surface. However, as this is analyte dependent, there is not a single set of SERS conditions that are universal. This means that experimental optimisation for optimum SERS response is vital. Most researchers optimise one factor at a time, where a single parameter is altered first before going onto optimise the next. This is a very inefficient way of searching the experimental landscape. In this review, we explore the use of more powerful multivariate approaches to SERS experimental optimisation based on design of experiments and evolutionary computational methods. We particularly focus on colloidal-based SERS rather than thin film preparations as a result of their popularity. © 2015 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons, Ltd.

Development of Rapid Detection and Genetic Characterization of Salmonella in Poultry Breeder Feeds

PubMed Central

Jarquin, Robin; Hanning, Irene; Ahn, Soohyoun; Ricke, Steven C.

2009-01-01

Salmonella is a leading cause of foodborne illness in the United States, with poultry and poultry products being a primary source of infection to humans. Poultry may carry some Salmonella serovars without any signs or symptoms of disease and without causing any adverse effects to the health of the bird. Salmonella may be introduced to a flock by multiple environmental sources, but poultry feed is suspected to be a leading source. Detecting Salmonella in feed can be challenging because low levels of the bacteria may not be recovered using traditional culturing techniques. Numerous detection methodologies have been examined over the years for quantifying Salmonella in feeds and many have proven to be effective for Salmonella isolation and detection in a variety of feeds. However, given the potential need for increased detection sensitivity, molecular detection technologies may the best candidate for developing rapid sensitive methods for identifying small numbers of Salmonella in the background of large volumes of feed. Several studies have been done using polymerase chain reaction (PCR) assays and commercial kits to detect Salmonella spp. in a wide variety of feed sources. In addition, DNA array technology has recently been utilized to track the dissemination of a specific Salmonella serotype in feed mills. This review will discuss the processing of feeds and potential points in the process that may introduce Salmonella contamination to the feed. Detection methods currently used and the need for advances in these methods also will be discussed. Finally, implementation of rapid detection for optimizing control methods to prevent and remove any Salmonella contamination of feeds will be considered. PMID:22346699

EPA worst case water microcosms for testing phage biocontrol of Salmonella.

PubMed

McLaughlin, Michael R; Brooks, John P

2008-01-01

A microplate method was developed as a tool to test phages for their ability to control Salmonella in aqueous environments. The method used EPA (U.S. Environmental Protection Agency) worst case water (WCW) in 96-well plates. The WCW provided a consistent and relatively simple defined turbid aqueous matrix, high in total organic carbon (TOC) and total dissolved salts (TDS), to simulate swine lagoon effluent, without the inconvenience of malodor and confounding effects from other biological factors. The WCW was originally defined to simulate high turbidity and organic matter in water for testing point-of-use filtration devices. Use of WCW to simulate lagoon effluent for phage testing is a new and innovative application of this matrix. Control of physical and chemical parameters (TOC, TDS, turbidity, temperature, and pH) allowed precise evaluation of microbiological parameters (Salmonella and phages). In a typical application, wells containing WCW were loaded with Salmonella enterica susp. enterica serovar Typhimurium (ATCC14028) and treated with phages alone and in cocktail combinations. Mean Salmonella inactivation rates (k, where the lower the value, the greater the inactivation) of phage treatments ranged from -0.32 to -1.60 versus -0.004 for Salmonella controls. Mean log(10) reductions (the lower the value, the greater the reduction) of Salmonella phage treatments were -1.60 for phage PR04-1, -2.14 for phage PR37-96, and -2.14 for both phages in a sequential cocktail, versus -0.08 for Salmonella controls. The WCW microcosm system was an effective tool for evaluating the biocontrol potential of Salmonella phages.

Immunisation of chickens with live Salmonella vaccines - Role of booster vaccination.

PubMed

Methner, U

2018-05-17

It is accepted that booster vaccinations of chickens with live Salmonella vaccines are essential part of vaccinations schemes to induce an effective adaptive immune response. As manufacturer of registered live Salmonella vaccines recommend different times of booster the question raises whether the duration between the first and second immunisation might influence the protective effect against Salmonella exposure. Chickens were immunised with a live Salmonella Enteritidis vaccine on day 1 of age followed by a booster vaccination at different intervals (day 28, 35 or 42 of age) to study the effects on the colonisation and invasion of the Salmonella vaccine strain, the humoral immune response and the efficacy against infection with Salmonella Enteritidis on day 56 of age. Immunisation of all groups resulted in a very effective adaptive immune response and a high degree of protection against severe Salmonella exposure, however, the time of booster had only an unverifiable influence on either the colonisation of the vaccine strain, the development of the humoral immune response or the colonisation of the Salmonella challenge strain. Therefore, the first oral immunisation of the chicks on day 1 of age seems to be of special importance and prerequisite for the development of the effective immune response. A booster immunisation should be carried out, however, the time of booster may vary between week 3 and week 7 of age of the chickens without adversely impact on the efficacy of the adaptive immune response or the protective effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electrochemical characterization of an immunosensor for Salmonella spp. detection

USDA-ARS?s Scientific Manuscript database

Immunosensors represent a rapid alternative method for diagnosing Salmonella contamination. The objective of this study was to develop and evaluate the performance of an electrochemical immunosensor for the detection of Salmonella spp., the most common foodborne pathogen worldwide. In the immunosens...

Control and monitoring of Salmonella in egg-laying chickens

USDA-ARS?s Scientific Manuscript database

Contaminated eggs have been internationally significant sources for the transmission of Salmonella infection to humans for several decades. Both the public and private sectors have invested substantial resources in comprehensive risk reduction and monitoring programs for Salmonella in commercial egg...

Survival of Salmonella spp. In Waste Egg Wash Water

EPA Science Inventory

The survival of salmonellae under various environmental conditions has been subject of numerous research studies. Due to low densities of these organisms in natural samples, laboratory or clinical cultures were used to ensure that the initial density of salmonellae was sufficien...

Bacteriophage cocktail for biocontrol of Salmonella in dried pet food.

PubMed

Heyse, Serena; Hanna, Leigh Farris; Woolston, Joelle; Sulakvelidze, Alexander; Charbonneau, Duane

2015-01-01

Human salmonellosis has been associated with contaminated pet foods and treats. Therefore, there is interest in identifying novel approaches for reducing the risk of Salmonella contamination within pet food manufacturing environments. The use of lytic bacteriophages shows promise as a safe and effective way to mitigate Salmonella contamination in various food products. Bacteriophages are safe, natural, highly targeted antibacterial agents that specifically kill bacteria and can be targeted to kill food pathogens without affecting other microbiota. In this study, we show that a cocktail containing six bacteriophages had a broadspectrum activity in vitro against a library of 930 Salmonella enterica strains representing 44 known serovars. The cocktail was effective against 95% of the strains in this tested library. In liquid culture dose-ranging experiments, bacteriophage cocktail concentrations of ≥10(8) PFU/ml inactivated more than 90% of the Salmonella population (10(1) to 10(3) CFU/ml). Dried pet food inoculated with a mixture containing equal proportions of Salmonella serovars Enteritidis (ATCC 4931), Montevideo (ATCC 8387), Senftenberg (ATCC 8400), and Typhimurium (ATCC 13311) and then surface treated with the six-bacteriophage cocktail (≥2.5 ± 1.5 × 10(6) PFU/g) achieved a greater than 1-log (P < 0.001) reduction compared with the phosphate-buffered saline-treated control in measured viable Salmonella within 60 min. Moreover, this bacteriophage cocktail reduced natural contamination in samples taken from an undistributed lot of commercial dried dog food that tested positive for Salmonella. Our results indicate that bacteriophage biocontrol of S. enterica in dried pet food is technically feasible.

Characterization of the RpoS Status of Clinical Isolates of Salmonella enterica

PubMed Central

Robbe-Saule, Véronique; Algorta, Gabriela; Rouilhac, Isabelle; Norel, Françoise

2003-01-01

The stationary-phase-inducible sigma factor, σS (RpoS), is the master regulator of the general stress response in Salmonella and is required for virulence in mice. rpoS mutants can frequently be isolated from highly passaged laboratory strains of Salmonella. We examined the rpoS status of 116 human clinical isolates of Salmonella, including 41 Salmonella enterica serotype Typhi strains isolated from blood, 38 S. enterica serotype Typhimurium strains isolated from blood, and 37 Salmonella serotype Typhimurium strains isolated from feces. We examined the abilities of these strains to produce the σS protein, to express RpoS-dependent catalase activity, and to resist to oxidative stress in the stationary phase of growth. We also carried out complementation experiments with a cloned wild-type rpoS gene. Our results showed that 15 of the 41 Salmonella serotype Typhi isolates were defective in RpoS. We sequenced the rpoS allele of 12 strains. This led to identification of small insertions, deletions, and point mutations resulting in premature stop codons or affecting regions 1 and 2 of σS, showing that the rpoS mutations are not clonal. Thus, mutant rpoS alleles can be found in freshly isolated clinical strains of Salmonella serotype Typhi, and they may affect virulence properties. Interestingly however, no rpoS mutants were found among the 75 Salmonella serotype Typhimurium isolates. Strains that differed in catalase activity and resistance to hydrogen peroxide were found, but the differences were not linked to the rpoS status. This suggests that Salmonella serotype Typhimurium rpoS mutants are counterselected because rpoS plays a role in the pathogenesis of Salmonella serotype Typhimurium in humans or in the transmission cycle of the disease. PMID:12902215

Salmonella Questions and Answers

MedlinePlus

... Forms Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District ... Inspection Service (FSIS) of the U.S. Department of Agriculture (USDA) is addressing the problems of Salmonella contamination ...

Antimicrobial resistance and management of invasive Salmonella disease.

PubMed

Kariuki, Samuel; Gordon, Melita A; Feasey, Nicholas; Parry, Christopher M

2015-06-19

Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20-30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50-75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries. Copyright © 2015. Published by Elsevier Ltd.

Antimicrobial resistance and management of invasive Salmonella disease

PubMed Central

Kariuki, Samuel; Gordon, Melita A.; Feasey, Nicholas; Parry, Christopher M

2015-01-01

Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20–30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50–75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries. PMID:25912288

Quinolone Resistance Mechanisms Among Salmonella enterica in Malaysia.

PubMed

Thong, Kwai Lin; Ngoi, Soo Tein; Chai, Lay Ching; Teh, Cindy Shuan Ju

2016-06-01

The prevalence of quinolone-resistant Salmonella enterica is on the rise worldwide. Salmonella enterica is one of the major foodborne pathogens in Malaysia. Therefore, we aim to investigate the occurrence and mechanisms of quinolone resistance among Salmonella strains isolated in Malaysia. A total of 283 Salmonella strains isolated from food, humans, and animals were studied. The disk diffusion method was used to examine the quinolone susceptibility of the strains, and the minimum inhibitory concentration (MIC) values of nalidixic acid and ciprofloxacin were also determined. DNA sequencing of the quinolone resistance-determining regions (QRDRs) of gyrase and topoisomerase IV genes and the plasmid-borne qnr genes was performed. The transfer of the qnr gene was examined through transconjugation experiment. A total of 101 nalidixic acid-resistant Salmonella strains were identified. In general, all strains were highly resistant to nalidixic acid (average MICNAL, 170 μg/ml). Resistance to ciprofloxacin was observed in 30.7% of the strains (1 ≤ MICCIP ≤ 2 μg/ml). Majority of the strains contained missense mutations in the QRDR of gyrA (69.3%). Silent mutations were frequently detected in gyrB (75.2%), parC (27.7%), and parE (51.5%) within and beyond the QRDRs. Novel mutations were detected in parC and parE. The plasmid-borne qnrS1 variant was found in 36.6% of the strains, and two strains were found to be able to transfer the qnrS1 gene. Overall, mutations in gyrA and the presence of qnrS1 genes might have contributed to the high level of quinolone resistance among the strains. Our study provided a better understanding on the status of quinolone resistance among Salmonella strains circulating in Malaysia.

Identification and characterization of salmonella serotypes using DNA spectral characteristics by fourier transform infrared (FT-IR) spectroscopy

USDA-ARS?s Scientific Manuscript database

Analysis of DNA samples of Salmonella serotypes (Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky) were performed using Fourier transform infrared spectroscopy (FT-IR) spectrometer by placing directly in contact with a diamond attenua...

LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium.

PubMed

Lee, Eun-Ju; Park, Kwan-Sik; Jeon, In-Sook; Choi, Jae-Woon; Lee, Sang-Jeon; Choy, Hyun E; Song, Ki-Duk; Lee, Hak-Kyo; Choi, Joong-Kook

2016-07-01

Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella-induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation.

LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium

PubMed Central

Lee, Eun-Ju; Park, Kwan-Sik; Jeon, In-Sook; Choi, Jae-Woon; Lee, Sang-Jeon; Choy, Hyun E.; Song, Ki-Duk; Lee, Hak-Kyo; Choi, Joong-Kook

2016-01-01

Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella-induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation. PMID:27329040

[Study on simultaneous contamination of Salmonella and Campylobacter in retail chicken carcasses in Beijing].

PubMed

Hu, Yujie; Wang, Yeru; Li, Fengqin

2015-01-01

To elucidate the simultaneous contamination of Salmonella and Campylobacter in retail chicken carcasses in Beijing and to carry out the serological typing of all Salmonella isolates as well as the identification of Campylobacter at the species level. A total of 33 chicken carcasses were collected from Beijing supermarkets and farm's trade markets from May to July. All samples were enumerated for Salmonella and Campylobacter. All Salmonella isolates obtained were further serotyped and Campylobacter were identified at the species level. Totally, 19 samples (19/33, 57.6%) and 5 samples (5/33, 15.2%) were positive for Salmonella with the mean level of 119.4 MPN/100g and Campylobacter with the mean level of 58.6 CFU/g, respectively. In terms of Salmonella, 166 isolates with 14 serotypes were obtained. Salmonella Enteritidis was the most common serovar detected followed by S. Indiana. Serovar diversity was very high in all Salmonella isolates and various Salmonella serovars were detected in the same chicken carcass. A total of 11 serovar distribution spectrums were found and S. Enteritidis in combination with S. Indiana was the predominant. The retail chicken carcasses in Beijing collected from May to July were heavily contaminated by Salmonella with high serovar diversity.

Isolation, characterization, and application of bacteriophages for Salmonella spp. biocontrol in pigs.

PubMed

Albino, Luiz A A; Rostagno, Marcos H; Húngaro, Humberto M; Mendonça, Regina C S

2014-08-01

Foodborne illness due to Salmonella-contaminated pork products is an important public health problem, causing significant economic losses worldwide. The use of bacteriophages is a potential intervention tool that has attracted interest for the control of foodborne pathogens. The objective of this study was to detect the presence of Salmonella in commercial pig farms and to isolate specific autochthonous bacteriophages against Salmonella Typhimurium, to characterize them and to evaluate their lytic capacity against Salmonella Typhimurium in vivo and in vitro. Salmonella was isolated on 50% (4/8) of the farms, with serotype Typhimurium being the most prevalent, detected in 48.2% of samples (13/27). The isolated Salmonella Typhimurium bacteriophages belong to the Podoviridae family, were active against serotypes Abony, Enteritidis, Typhi, and Typhimurium, but not against serotypes Arizonae, Cholerasuis, Gallinarum, and Pullorum. In in vitro tests, bacteriophage at 10(7) PFU/mL and 10(9) PFU/mL significantly reduced (p<0.05) Salmonella Typhimurium counts in 1.6 and 2.5 log10 colony-forming units (CFU)/mL, respectively, after 24 h. Before the in vivo treatment with bacteriophages, Salmonella was identified in 93.3% (28/30) of the fecal samples from the pigs inoculated with 10(6) CFU/mL, and only in 56.6% (17/30) after the treatment consisting of oral administration of the pool of the bacteriophages after the fasting period, simulating a common preslaughter practice. These results indicate that the pool of bacteriophages administered was capable of reducing the colonization of Salmonella in pigs.

Development of a Salmonella cross-protective vaccine for food animal production systems.

PubMed

Heithoff, Douglas M; House, John K; Thomson, Peter C; Mahan, Michael J

2015-01-01

Intensive livestock production is associated with increased Salmonella exposure, transmission, animal disease, and contamination of food and water supplies. Modified live Salmonella enterica vaccines that lack a functional DNA adenine methylase (Dam) confer cross-protection to a diversity of salmonellae in experimental models of murine, avian, ovine, and bovine models of salmonellosis. However, the commercial success of any vaccine is dependent upon the therapeutic index, the ratio of safety/efficacy. Herein, secondary virulence-attenuating mutations targeted to genes involved in intracellular and/or systemic survival were introduced into Salmonella dam vaccines to screen for vaccine candidates that were safe in the animal and the environment, while maintaining the capacity to confer cross-protective immunity to pathogenic salmonellae serotypes. Salmonella dam mgtC, dam sifA, and dam spvB vaccine strains exhibited significantly improved vaccine safety as evidenced by the failure to give rise to virulent revertants during the infective process, contrary to the parental Salmonella dam vaccine. Further, these vaccines exhibited a low grade persistence in host tissues that was associated with reduced vaccine shedding, reduced environmental persistence, and induction of cross-protective immunity to pathogenic serotypes derived from infected livestock. These data indicate that Salmonella dam double mutant vaccines are suitable for commercial applications against salmonellosis in livestock production systems. Reducing pre-harvest salmonellae load through vaccination will promote the health and productivity of livestock and reduce contamination of livestock-derived food products, while enhancing overall food safety. Copyright © 2014 Elsevier Ltd. All rights reserved.

A rabbit model of non-typhoidal Salmonella bacteremia.

PubMed

Panda, Aruna; Tatarov, Ivan; Masek, Billie Jo; Hardick, Justin; Crusan, Annabelle; Wakefield, Teresa; Carroll, Karen; Yang, Samuel; Hsieh, Yu-Hsiang; Lipsky, Michael M; McLeod, Charles G; Levine, Myron M; Rothman, Richard E; Gaydos, Charlotte A; DeTolla, Louis J

2014-09-01

Bacteremia is an important cause of morbidity and mortality in humans. In this study, we focused on the development of an animal model of bacteremia induced by non-typhoidal Salmonella. New Zealand White rabbits were inoculated with a human isolate of non-typhoidal Salmonella strain CVD J73 via the intra-peritoneal route. Blood samples were collected at specific time points and at euthanasia from infected rabbits. Additionally, tissue samples from the heart, lungs, spleen, gastrointestinal tract, liver and kidneys were obtained at euthanasia. All experimentally infected rabbits displayed clinical signs of disease (fever, dehydration, weight loss and lethargy). Tissues collected at necropsy from the animals exhibited histopathological changes indicative of bacteremia. Non-typhoidal Salmonella bacteria were detected in the blood and tissue samples of infected rabbits by microbiological culture and real-time PCR assays. The development of this animal model of bacteremia could prove to be a useful tool for studying how non-typhoidal Salmonella infections disseminate and spread in humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

Salmonella modulation of host cell gene expression promotes its intracellular growth.

PubMed

Hannemann, Sebastian; Gao, Beile; Galán, Jorge E

2013-01-01

Salmonella Typhimurium has evolved a complex functional interface with its host cell largely determined by two type III secretion systems (T3SS), which through the delivery of bacterial effector proteins modulate a variety of cellular processes. We show here that Salmonella Typhimurium infection of epithelial cells results in a profound transcriptional reprogramming that changes over time. This response is triggered by Salmonella T3SS effector proteins, which stimulate unique signal transduction pathways leading to STAT3 activation. We found that the Salmonella-stimulated changes in host cell gene expression are required for the formation of its specialized vesicular compartment that is permissive for its intracellular replication. This study uncovers a cell-autonomous process required for Salmonella pathogenesis potentially opening up new avenues for the development of anti-infective strategies that target relevant host pathways.

[Use of bacteriphages against Salmonella Enteritidis: a prevention tool].

PubMed

García, Cristina; Marín, Clara; Catalá-Gregori, Pablo; Soriano, Jose Miguel

2015-06-01

Salmonellosis is a highly prevalent disease still searching for preventive tools to avoid contamination level priority public health. The in vitro effect of bacteriophages against Salmonella enteritidis was evaluated as a prevention tool. Two tests with three concentrations of bacteriophages were conducted against two strains of Salmonella Enteritidis inoculated in fresh faeces of laying hens. Each test had a positive control. Thus, four groups in each test were evaluated. Each experimental group included two replicates, and three plates were incubated per replicate. The concentrations tested were three: commercial solution (5 × 10(7) pfu/mL), and two dilutions (1/10 and 1/30). One of the strains tested was CECT 4300, a certified strain of Colección Española de Cultivo Tipo and the other a field isolated strain in a sacrificed hen farm. Both strains were inoculated at 1.3 × 10(5) cfu/g of faeces in each of the four groups. Isolation and identification of bacteria by ISO6579 was done at various times after inoculation: 1 minute, 24 hours and 7 days. In the first test, with certified strain, Salmonella was isolated in all groups at time 1 minute. After 24 hours, Salmonella was isolated in all groups except in one of the replicas treated with 1/10 dilution of bacteriophages, one of the other replica plate treated with 1/10 dilution, and two plates of the two replicas treated with the commercial solution. After 7 days, the bacteria were not isolated from any of the experimental groups. In the second test, with the field strain, Salmonella was isolated in all groups at time 1 minute. After 24 hours, Salmonella was isolated in all groups except in one of the replicas treated with 1/10 dilution of bacteriophages and the two replicas treated with the commercial solution. Salmonella was not isolated in any of the experimental groups at 7 days. The use of bacteriophages reduced Salmonella enteritidis isolates in faeces at 24 hours after the application, so it could be

Prevalence and molecular profiles of Salmonella collected at a commercial turkey processing plant.

PubMed

Nde, Chantal W; Sherwood, Julie S; Doetkott, Curt; Logue, Catherine M

2006-08-01

In this study, whole carcasses were sampled at eight stages on a turkey-processing line and Salmonella prevalence was determined using enrichment techniques. Recovered Salmonella was further characterized using serotyping and the molecular profiles were determined using pulsed-field gel electrophoresis (PFGE). Prevalence data showed that contamination rates varied along the line and were greatest after defeathering and after chilling. Analysis of contamination in relation to serotypes and PFGE profiles found that on some visits the same serotype was present all along the processing line while on other days, additional serotypes were recovered that were not detected earlier on the line, suggesting that the birds harbored more than one serotype of Salmonella or there was cross-contamination occurring during processing. Overall, this study found fluctuations in Salmonella prevalence along a turkey-processing line. Following washing, Salmonella prevalence was significantly reduced, suggesting that washing is critical for Salmonella control in turkey processing and has significant application for controlling Salmonella at the postdefeathering and prechill stages where prevalence increased.

76 FR 81513 - Guidance for Industry: Prevention of Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-28

...] Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation.'' The document provides guidance to egg producers on how to comply with certain provisions contained in FDA's...

Differences in carbon source utilization of Salmonella Oranienburg and Saintpaul isolated from river water.

PubMed

Medrano-Félix, Andrés; Estrada-Acosta, Mitzi; Peraza-Garay, Felipe; Castro-Del Campo, Nohelia; Martínez-Urtaza, Jaime; Chaidez, Cristóbal

2017-08-01

Long-term exposure to river water by non-indigenous micro-organisms such as Salmonella may affect metabolic adaptation to carbon sources. This study was conducted to determine differences in carbon source utilization of Salmonella Oranienburg and Salmonella Saintpaul (isolated from tropical river water) as well as the control strain Salmonella Typhimurium exposed to laboratory, river water, and host cells (Hep-2 cell line) growth conditions. Results showed that Salmonella Oranienburg and Salmonella Saintpaul showed better ability for carbon source utilization under the three growth conditions evaluated; however, S. Oranienburg showed the fastest and highest utilization on different carbon sources, including D-Glucosaminic acid, N-acetyl-D-Glucosamine, Glucose-1-phosphate, and D-Galactonic acid, while Salmonella Saintpaul and S. Typhimurium showed a limited utilization of carbon sources. In conclusion, this study suggests that environmental Salmonella strains show better survival and preconditioning abilities to external environments than the control strain based on their plasticity on diverse carbon sources use.

Specialized Transducing Phages Derived from Salmonella Phage P22

PubMed Central

Hoppe, Ingrid; Roth, John

1974-01-01

Salmonella phage P22 has been used in the construction of three sorts of specialized transducing phage: P22 proAB, P22 proABlac and P22 argF. The bacterial genes carried are derived from E. coli K12. Since E. coli and Salmonella chromosomes recombine very poorly, E. coli genes cannot be transduced into Salmonella recipients by P22's generalized transduction mechanism. Therefore, stable inheritance of E. coli material provides a means of detecting specialized transduction. Formation of these phages was possible because the P22 prophage recognizes an attachment site in the E. coli F' prolac episome. Salmonella strains carrying the F' prolac episome can be lysogenized by P22 so as to leave the prophage inserted into the E. coli material of the F' factor. Improper prophage excision can then lead to formation of P22 specialized phages carrying E. coli genetic material. PMID:4599252

SERS as analytical tool for detection of bacteria

NASA Astrophysics Data System (ADS)

Cialla, Dana; Rösch, Petra; Möller, Robert; Popp, Jürgen

2007-07-01

The detection of single bacteria should be improved by lowering the acquisition time via the application of SERS (surface enhanced Raman spectroscopy). Nano structured colloids or surfaces consisting of gold or silver can be used as SERS active substrates. However, for biological applications mostly gold is used as SERS active substrate since silver is toxic for bacterial cells. Furthermore, the application of gold as a SERS-active substrate allows the usage of Raman excitation wavelengths in the red part of the electromagnetic spectrum. For the SERS investigations on bacteria different colloids (purchased and self prepared, preaggregated and non-aggregated) are chosen as SERS active substrates. The application of different gold colloids under gently mixing conditions to prevent the bacterial damage allowed the recording of reproducible SERS spectra of bacteria. The SERS spectra of B. pumilus are dominated by contributions of ingredients of the outer cell wall, e.g. the peptidoglycan layer. SEM images of the coated bacteria demonstrate the incomplete adsorption most probably due to variations within the binding affinities between different outer cell components and the gold colloids.

Prevalence and antimicrobial resistance pattern of Salmonella in animal feed produced in Namibia.

PubMed

Shilangale, Renatus P; Di Giannatale, Elisabetta; Chimwamurombe, Percy M; Kaaya, Godwin P

2012-01-01

The occurrence of Salmonella is a global challenge in the public health and food production sectors. Our study investigated the prevalence, serovar and antimicrobial susceptibility of strains of Salmonella serovars isolated from animal feed (meat-and-bone and blood meal) samples from two commercial abattoirs in Namibia. A total of 650 samples (n=650) were examined for the presence of Salmonella. Results showed that 10.9% (n=71) were positive for Salmonella. Of the Salmonella serovars isolated, S. Chester was the most commonly isolated serovar (19.7%), followed by S. Schwarzengrund at 12.7%. From the Salmonella isolates, 19.7% (n=14) were resistant to one or more of the antimicrobials (nalidixic acid, trimethoprim-sulfamethoxazole, sulfisoxazole, streptomycin and/or tetracycline), whereas 80.3% (n=57) were susceptible to all 16 antimicrobials tested. Resistance to sulfisoxazole and the trimethroprimsuflamethoxazole combination were the most common. The resistant isolates belonged to ten different Salmonella serovars. The susceptibility of most of the Salmonella isolated to the antimicrobials tested indicates that anti-microbial resistance is not as common and extensive in Namibia as has been reported in many other countries. It also appears that there is a range of antimicrobials available that are effective in managing Salmonella infections in Namibia. However, there is some evidence that resistance is developing and this will need further monitoring to ensure it does not become a problem.

Review of SERS Substrates for Chemical Sensing

PubMed Central

Mosier-Boss, Pamela A.

2017-01-01

The SERS effect was initially discovered in the 1970s. Early research focused on understanding the phenomenon and increasing enhancement to achieve single molecule detection. From the mid-1980s to early 1990s, research started to move away from obtaining a fundamental understanding of the phenomenon to the exploration of analytical applications. At the same time, significant developments occurred in the field of photonics that led to the advent of inexpensive, robust, compact, field-deployable Raman systems. The 1990s also saw rapid development in nanoscience. This convergence of technologies (photonics and nanoscience) has led to accelerated development of SERS substrates to detect a wide range of chemical and biological analytes. It would be a monumental task to discuss all the different kinds of SERS substrates that have been explored. Likewise, it would be impossible to discuss the use of SERS for both chemical and biological detection. Instead, a review of the most common metallic (Ag, Cu, and Au) SERS substrates for chemical detection only is discussed, as well as SERS substrates that are commercially available. Other issues with SERS for chemical detection have been selectivity, reversibility, and reusability of the substrates. How these issues have been addressed is also discussed in this review. PMID:28594385

Label-free in situ SERS imaging of biofilms.

PubMed

Ivleva, Natalia P; Wagner, Michael; Szkola, Agathe; Horn, Harald; Niessner, Reinhard; Haisch, Christoph

2010-08-12

Surface-enhanced Raman scattering (SERS) is a promising technique for the chemical characterization of biological systems. It yields highly informative spectra, can be applied directly in aqueous environment, and has high sensitivity in comparison with normal Raman spectroscopy. Moreover, SERS imaging can provide chemical information with spatial resolution in the micrometer range (chemical imaging). In this paper, we report for the first time on the application of SERS for in situ, label-free imaging of biofilms and demonstrate the suitability of this technique for the characterization of the complex biomatrix. Biofilms, being communities of microorganisms embedded in a matrix of extracellular polymeric substances (EPS), represent the predominant mode of microbial life. Knowledge of the chemical composition and the structure of the biofilm matrix is important in different fields, e.g., medicine, biology, and industrial processes. We used colloidal silver nanoparticles for the in situ SERS analysis. Good SERS measurement reproducibility, along with a significant enhancement of Raman signals by SERS (>10(4)) and highly informative SERS signature, enables rapid SERS imaging (1 s for a single spectrum) of the biofilm matrix. Altogether, this work illustrates the potential of SERS for biofilm analysis, including the detection of different constituents and the determination of their distribution in a biofilm even at low biomass concentration.

Camel as a transboundary vector for emerging exotic Salmonella serovars.

PubMed

Ghoneim, Nahed H; Abdel-Moein, Khaled A; Zaher, Hala

2017-05-01

The current study was conducted to shed light on the role of imported camels as a transboundary vector for emerging exotic Salmonella serovars. Fecal samples were collected from 206 camels directly after slaughtering including 25 local camels and 181 imported ones as well as stool specimens were obtained from 50 slaughterhouse workers at the same abattoir. The obtained samples were cultured while Salmonella serovars were identified through Gram's stain films, biochemical tests and serotyping with antisera kit. Moreover, the obtained Salmonella serovars were examined by PCR for the presence of invA and stn genes. The overall prevalence of Salmonella serovars among the examined camels was 8.3%. Stn gene was detected in the vast majority of exotic strains (11/14) 78.6% including emerging serovars such as Salmonella Saintpaul, S. Chester, S. Typhimurium whereas only one isolate from local camels carried stn gene (1/3) 33.3%. On the other hand, none of the examined humans yielded positive result. Our findings highlight the potential role of imported camels as a transboundary vector for exotic emerging Salomenella serovars.

[Protagonists of innate immunity during in Salmonella infections].

PubMed

Salez, Laurent; Malo, Danielle

2004-12-01

Salmonella are facultative intracellular Gram-negative bacteria that are found ubiquitously in nature and have the ability to infect a wide range of hosts including humans, domesticated, wild mammals, and birds. The principal clinical manifestations associated with Salmonella infection in humans are enteric fever (typhoid and paratyphoid) and a self-limiting gastroenteritis (salmonellosis). Additionally, silent carriage of this bacterium is frequent and contributes to disease dissemination. Typhoid fever still represents a major public health problem in many developing countries. On the other hand, industrialized countries experience an increased incidence of nontyphoidal Salmonella infections with most cases tracing back to food contamination. Studies using mouse model of infection with a highly virulent Salmonella typhimurium serotype have provided important insight into the complexity of the innate immune response to infection. The players are numerous but emphasis was placed on the genes that were discovered using genetic approaches and in vivo assay with live pathogen and include positional cloning of mouse mutations and manipulation of genes in the context of whole animal either by transgenesis or knockout technologies. Some of the critical genes include those known to play a role in the detection of the bacteria (Cd14, Lbp, Tlr4 and Tlr5) and in microbicidal activity (Slc11a1, Nos2, NADPH oxidase and cryptdins). These discoveries have already initiated the search for the contribution of particular genetic pathways in the innate immune response of humans to infection with Salmonella and other intracellular microorganisms.

Persistence of poultry associated Salmonella spp. on spinach plants

USDA-ARS?s Scientific Manuscript database

Introduction: Pre-harvest spinach contamination can occur via irrigation water and can influence the persistence of Salmonella on spinach leaves. Salmonella persistence on spinach plants should be evaluated as nearby poultry farms can be a critical source of contaminated water run-off. Purpose: The...

Nano-materials for use in sensing of salmonella infections: Recent advances.

PubMed

Pashazadeh, Paria; Mokhtarzadeh, Ahad; Hasanzadeh, Mohammad; Hejazi, Maryam; Hashemi, Maryam; de la Guardia, Miguel

2017-01-15

Salmonella infectious diseases spreading every day through food have become a life-threatening problem for millions of people and growing menace to society. Health expert's estimate that the yearly cost of all the food borne diseases is approximately $5-6 billion. Traditional methodologies for salmonella analysis provide high reliability and very low limits of detection. Among them immunoassays and Nucleic acid-based assays provide results within 24h, but they are expensive, tedious and time consuming. So, there is an urgent need for development of rapid, robust and cost-effective alternative technologies for real-time monitoring of salmonella. Several biosensors have been designed and commercialized for detection of this pathogen in food and water. In this overview, we have updated the literature concerning novel biosensing methods such as various optical and electrochemical biosensors and newly developed nano- and micro-scaled and aptamers based biosensors for detection of salmonella pathogen. Furthermore, attention has been focused on the principal concepts, applications, and examples that have been achieved up to diagnose salmonella. In addition, commercial biosensors and foreseeable future trends for onsite detecting salmonella have been summarized. Copyright © 2016 Elsevier B.V. All rights reserved.

Advanced Oxidation Process sanitization of hatching eggs reduces Salmonella in broiler chicks.

PubMed

Rehkopf, A C; Byrd, J A; Coufal, C D; Duong, T

2017-10-01

The microbial quality of eggs entering the hatchery is an important critical control point for biosecurity, pathogen reduction, and food safety programs in poultry production. Developing interventions to reduce Salmonella contamination of eggs is important to improving the microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet light (UV) Advanced Oxidation Process (AOP) has been previously demonstrated to be effective in reducing Salmonella on the surface of experimentally contaminated eggs. The objective of this study was to evaluate the effect of treating eggs with an egg-sanitizing apparatus using the H2O2/UV AOP on Salmonella contamination during incubation, hatching, and in broiler chicks during grow-out. Experimentally contaminated eggs were treated using the automated H2O2/UV AOP egg sanitizer and incubated for 21 d. AOP sanitization reduced Salmonella up to 7 log10 cfu egg-1 (P < 0.05) from the surface of experimentally contaminated eggs and reduced the number of Salmonella positive eggs by up to 75% (P < 0.05) when treated 1 h post-inoculation. AOP treatment also reduced the number of Salmonella-positive eggs during incubation. Additionally, Salmonella was recovered from more chicks hatched from untreated eggs than from eggs treated using the H2O2/UV AOP egg sanitizer (P < 0.05) through 14 d posthatch. These data suggest reduction of Salmonella contamination on the surface of eggs using the H2O2/UV AOP egg sanitizer prior to incubation may reduce the gastrointestinal colonization of chicks by Salmonella. © 2017 Poultry Science Association Inc.

Foodborne Salmonella-caused outbreaks in Catalonia (Spain), 1990 to 2003.

PubMed

Domínguez, Angela; Torner, Nuria; Ruiz, Laura; Martínez, Ana; Bartolomé, Rosa; Sulleiro, Elena; Teixidó, Angel; Plasencia, Antoni

2007-01-01

In most developed countries, nontyphoid Salmonella is an important cause of sporadic cases and outbreaks of foodborne gastroenteritis. The aim of this study was to investigate the trend of foodborne Salmonella-caused outbreaks and number of cases, hospitalizations, and deaths and compare them with those caused by other infectious agents. The study was carried out in Catalonia, a region in northeastern Spain with a population of 6.5 million inhabitants, in 2002. All information on reported outbreaks of foodborne disease from 1990 to 2003 was reviewed. For each outbreak, the following variables were collected: year; setting (household, restaurant, school, hospital, nursing home, and others); number of cases, hospitalizations, and deaths; causal agent; and food vehicle involved. Of 1652 reported outbreaks, 1078 had a known causal agent. Among them, 871 (80.8%) were caused by Salmonella, with 14,695 cases, 1534 hospitalizations, and 4 deaths. The rate of hospitalization was higher in outbreaks due to Salmonella than in those caused by other infectious agents (rate ratio, 2.54; 95% confidence interval, 2.20 to 2.94). Forty-eight percent of Salmonella-caused outbreaks were eggborne, compared with 5.3% of those caused by other infectious agents (rate ratio, 1.40; 95% confidence interval, 1.33 to 1.48). The annual number of cases in household outbreaks of eggborne Salmonella rose over time (R2 = 0.82), but the number of outbreaks produced in other settings did not. Eggborne outbreaks caused by Salmonella in households are a major cause of disease, and increased preventive efforts are necessary, especially consumer education and awareness of the risk of eating food containing raw or slightly cooked eggs.

Effect of farm type on within-herd Salmonella prevalence, serovar distribution, and antimicrobial resistance.

PubMed

Rasschaert, G; Michiels, J; Arijs, D; Wildemauwe, C; De Smet, S; Heyndrickx, M

2012-05-01

Salmonella represents a major challenge to the pig industry, as pork presents a risk for human salmonellosis. In this study, we have examined the effect of farm type on the prevalence of fattening pigs shedding Salmonella on 12 farms at risk for harboring Salmonella. On six open (grow-to-finish) and six closed (farrow-to-finish) farms, the prevalence of pigs shedding Salmonella was determined on two occasions approximately 2 months apart. The serovar, phage type, and antimicrobial resistance of the obtained Salmonella isolates were determined. On all farms, pigs shedding Salmonella were detected on at least one of the two sampling days. The mean within-herd prevalence was 7.8%. Closed farms were two times less likely to have pigs shedding Salmonella than open farms. On open farms, the odds of finding Salmonella shedding in pigs were 1.9 times higher when sampling was performed at slaughter age than when samples were taken halfway through the fattening period. Salmonella enterica serovar Typhimurium was the most predominant serotype, with a prevalence of 62 to 63% on both farm types. Of all the Salmonella Typhimurium isolates, 65% had the tetraresistant profile ASSuT (ampicillin, streptomycin, sulfonamide, and tetracycline) with or without additional resistance to trimethoprim-sulfonamide. Phage type DT120 seemed to be especially associated with this antimicrobial-resistant profile. The prevalence of Salmonella Typhimurium isolates showing resistance to ampicillin, streptomycin, tetracycline, sulfonamide, trimethoprim-sulfonamide, and lincomycin hydrochloride and spectinomycin sulfate tetrahydrate was significantly higher on open farms than on closed farms.

Enjoying Homemade Ice Cream without the Risk of Salmonella Infection

MedlinePlus

... Contaminants Buy, Store & Serve Safe Food Enjoying Homemade Ice Cream without the Risk of Salmonella Infection Share ... it Email Print August 2004 Every year homemade ice cream causes several outbreaks of Salmonella infection with ...

Split marketing as a risk factor for Salmonella enterica infection in swine.

PubMed

Rostagno, Marcos H; Hurd, H Scott; McKean, James D

2009-09-01

On-farm reduction of Salmonella carriage prevalence in pigs requires the identification of risk factors to direct interventions development. This study was designed to determine if split marketing of finishing pigs constitutes a risk factor for Salmonella infections, by comparing Salmonella prevalence in the first group of pigs selected for harvest ("first pull") versus the prevalence in the last group of pigs selected for harvest ("close out") from multiple commercial finishing lots. Nine paired samplings were conducted consisting in matched groups of pigs from individual barns as the first pull and the close out with a 4-week interval between groups. From each group, fecal and meat samples were collected, on-farm and at harvest, respectively. Fecal samples were selectively enriched, and analyzed for the presence of Salmonella, whereas meat juice samples were analyzed for the presence of antibodies against Salmonella. In 7/9 (77.8%) of the studied barns, an increase in Salmonella prevalence was observed, based on both bacteriologic and serologic analysis. Overall, there was an increase of 9.2% (p < 0.05) in bacteriologic prevalence, and 31.3% (p < 0.05) in serologic prevalence from first pull to close out groups. This study demonstrates that a significant increase in Salmonella prevalence occurs between the first and the last group of pigs harvested from finishing lots, with close out groups of market pigs posing a higher risk for Salmonella contaminations.

Age-Dependent Enterocyte Invasion and Microcolony Formation by Salmonella

PubMed Central

Zhang, Kaiyi; Dupont, Aline; Torow, Natalia; Gohde, Fredrik; Leschner, Sara; Lienenklaus, Stefan; Weiss, Siegfried; Brinkmann, Melanie M.; Kühnel, Mark; Hensel, Michael; Fulde, Marcus; Hornef, Mathias W.

2014-01-01

The coordinated action of a variety of virulence factors allows Salmonella enterica to invade epithelial cells and penetrate the mucosal barrier. The influence of the age-dependent maturation of the mucosal barrier for microbial pathogenesis has not been investigated. Here, we analyzed Salmonella infection of neonate mice after oral administration. In contrast to the situation in adult animals, we observed spontaneous colonization, massive invasion of enteroabsorptive cells, intraepithelial proliferation and the formation of large intraepithelial microcolonies. Mucosal translocation was dependent on enterocyte invasion in neonates in the absence of microfold (M) cells. It further resulted in potent innate immune stimulation in the absence of pronounced neutrophil-dominated pathology. Our results identify factors of age-dependent host susceptibility and provide important insight in the early steps of Salmonella infection in vivo. We also present a new small animal model amenable to genetic manipulation of the host for the analysis of the Salmonella enterocyte interaction in vivo. PMID:25210785

Animal Salmonella surveillance in Peninsular Malaysia, 1981-1985.

PubMed Central

Joseph, P. G.; Sivanandan, S. P.; Yee, H. T.

1988-01-01

During the 5-year (1981-5) surveillance period, 2322 salmonella isolations were recorded from animals and other non-human sources in Peninsular Malaysia. This was an increase of 356% over the preceding 5-year period. The 83 serotypes isolated were recovered from 41 sources. Of these 34 were new serotypes bringing the total number of serotypes isolated from non-human sources to date up 97. Food animals and edible animal products accounted for 92.2% of the total isolations, with cattle and beef accounting for 70% of the total. Salmonella dublin was the most frequently isolated serotype, whereas S. typhimurium had the widest zoological distribution. More than 80% of the non-human salmonella serotypes have also been reported in man in this country. PMID:3378581

Improving Salmonella determination in Sinaloa rivers with ultrafiltration and most probable number methods.

PubMed

Jimenez, Maribel; Chaidez, Cristobal

2012-07-01

Monitoring of waterborne pathogens is improved by using concentration methods prior to detection; however, direct microbial enumeration is desired to study microbial ecology and human health risks. The aim of this work was to determine Salmonella presence in river water with an ultrafiltration system coupled with the ISO 6579:1993 isolation standard method (UFS-ISO). Most probable number (MPN) method was used directly in water samples to estimate Salmonella populations. Additionally, the effect between Salmonella determination and water turbidity was evaluated. Ten liters or three tenfold dilutions (1, 0.1, and 0.01 mL) of water were processed for Salmonella detection and estimation by the UFS-ISO and MPN methods, respectively. A total of 84 water samples were tested, and Salmonella was confirmed in 64/84 (76%) and 38/84 (44%) when UFS-ISO and MPN were used, respectively. Salmonella populations were less than 5 × 10(3) MPN/L in 73/84 of samples evaluated (87%), and only three (3.5%) showed contamination with numbers greater than 4.5 × 10(4) MPN/L. Water turbidity did not affect Salmonella determination regardless of the performed method. These findings suggest that Salmonella abundance in Sinaloa rivers is not a health risk for human infections in spite of its persistence. Thus, choosing the appropriate strategy to study Salmonella in river water samples is necessary to clarify its behavior and transport in the environment.

Prevalence, molecular and antimicrobial resistance of Salmonella isolated from sausages in Meknes, Morocco.

PubMed

Ed-Dra, Abdelaziz; Filali, Fouzia Rhazi; Karraouan, Bouchra; El Allaoui, Abdellah; Aboulkacem, Amal; Bouchrif, Brahim

2017-04-01

Salmonella is among the most important food borne pathogens worldwide contaminating a wide range of animal products including meat products. The aims of this study go through two steps: The first step is to estimate the proportion of sausages products contaminated with Salmonella in Meknes city (Morocco), which were collected from various shopping sites: butchery, street vendors, supermarket and souk (Weekly market combines the population of the small villages around Meknes city). The second one is to identify serovars, to determine the antimicrobials resistance patterns of isolates and to detect the invA and spvC genes. 34 (21.79%) Salmonella were isolated, recovered 4 serogroups and 12 serotypes. The most prevalent serotypes were Salmonella Corvallis (23.53%) and Salmonella Kentucky (17.65%). All Salmonella isolates were tested for their susceptibility to 18 selected antimicrobials agents, of which 100% were resistant to at least one antimicrobial, 85.30% (29/34) were resistant to two or more antimicrobials and 44.12% (15/34) were resistant to at least three antimicrobials. All Salmonella are resistant to ampicillin, 76.47% to streptomycin, 20.59% to sulfonamides, 17.65% to Tetracycline and 11.77% to Ofloxacin. The "ACSSuT" penta-resistance pattern was observed in tow of the Salmonella Typhimurium strains. In addition, this study showed that all Salmonella strains (34) were positive for invasion gene invA and negative for the virulence gene spvC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Disinfectant susceptibility of different Salmonella serotypes isolated from chicken and egg production chains.

PubMed

Long, M; Lai, H; Deng, W; Zhou, K; Li, B; Liu, S; Fan, L; Wang, H; Zou, L

2016-09-01

The study aimed to serotype the Salmonella isolates recovered from chicken and egg production chains, and to investigate the disinfectant resistance phenotypes and genotypes of these isolates. The Salmonella isolates were serotyped, and the minimal inhibitory concentrations (MICs) of disinfectants were determined. Results showed that the Salmonella isolates recovered from both chains were diverse, and the serotypes in each part of the production chain and between the two production chains were significantly different. In the chicken production chain, 19 different serotypes were recovered, while only five serotypes were found in the egg production chain. The isolates showed a high susceptibility to didecyldimethylammonium bromide (DDAB) but a low susceptibility to benzalkonium chloride (BC), benzalkonium bromide (BAB) and chlorhexidine (CHX). Salmonella Enteritidis and Salmonella Typhimurium were more resistant to BC and BAB. The qacEΔ1 and qacF resistance genes were detected in 26·7 and 7·7% of the isolates respectively. The qacEΔ1 gene was frequently found in Salmonella Derby and Salm. Enteritidis (P < 0·05). Our findings indicated that Salmonella was commonly present in both chains, and could serve as a critical vector in spreading disinfectant resistance associated with different serotypes. This study first demonstrated disinfectant resistance phenotypes and genotypes of serotyped Salmonella. The study highlights the need for monitoring the disinfectant resistance varied in different Salmonella serotypes. © 2016 The Society for Applied Microbiology.

Predicting Salmonella populations from biological, chemical, and physical indicators in Florida surface waters.

PubMed

McEgan, Rachel; Mootian, Gabriel; Goodridge, Lawrence D; Schaffner, Donald W; Danyluk, Michelle D

2013-07-01

Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R(2) < 0.1) and between physicochemical indicators and Salmonella levels (R(2) < 0.1). The average rainfall (previous day, week, and month) before sampling did not correlate well with bacterial levels. Logistic regression analysis showed that E. coli concentration can predict the probability of enumerating selected Salmonella levels. The lack of good correlations between biological indicators and Salmonella levels and between physicochemical indicators and Salmonella levels shows that the relationship between pathogens and indicators is complex. However, Escherichia coli provides a reasonable way to predict Salmonella levels in Central Florida surface water through logistic regression.

Prevalence of Salmonella spp. in environmental samples from table egg barns in Alberta.

PubMed

St Amand, Joan A; Cassis, Rashed; King, Robin K; Annett Christianson, Colleen B

2017-12-01

Some Salmonella spp. are zoonotic, a frequent cause of foodborne illness in Canada, and known to infect humans through contaminated poultry and poultry products. Certain serotypes of Salmonella spp. have been demonstrated to be vertically transmitted from hen to egg. The incidence of Salmonella spp. isolation in the flock has been correlated to its isolation from the environment. Twenty-one producers were enrolled in this study to examine the occurrence of Salmonella spp. in 48 table egg layer flocks housed in 35 barns in Alberta. The purpose of this study was to: (i) identify Salmonella serotypes isolated from the environment of table egg layer facilities in Alberta and (ii) record the prevalence of Salmonella spp. across eight defined environmental sampling points. Salmonella spp. were isolated from the environment of 20/35 barns representing 29/48 flocks. The most common serotypes isolated were S. Heidelberg, S. Kentucky and S. Mbandaka. The order of most to least contaminated sample location was manure belts (54.1%), feeders (47.9%), feed motors (45.8%), egg belts and walls (41.7%), fans (35.0%), cage bottoms (31.3%) and lobbies (27.1%). Salmonella spp. were isolated from 7/7 barns post cleaning and disinfection, demonstrating the persistence of this organism in the environment and the need for effective eradication protocols.

Antimicrobial resistance among Salmonella enterica serovar Infantis from broiler carcasses in Serbia

NASA Astrophysics Data System (ADS)

Nikolić, A.; Baltić, T.; Velebit, B.; Babić, M.; Milojević, L.; Đorđević, V.

2017-09-01

This study aimed to investigate antimicrobial resistance of Salmonella Infantis isolates from poultry carcasses in Serbia. A total of 48 Salmonella isolates were examined for antimicrobial resistance. A panel of 10 antibiotics was selected for testing. Isolates showed resistance to sulfamethoxazole, ceftazidime and cefotaxime (100%). However, the highest number of Salmonella Infantis isolates were sensitive to chloramphenicol. The usage of antibiotics in food producing animals could result in antimicrobial resistance pathogenic bacteria especially Salmonella spp. in poultry, which may be transmitted to humans through the food chain and increase risk of treatment failures.

Prevalence and antibiogram study of Salmonella and Staphylococcus aureus in poultry meat

PubMed Central

Akbar, Ali; Anal, Anil Kumar

2013-01-01

Objective To evaluate the presence and antibiogram pattern of Salmonella and Staphylococcus aureus (S. aureus) in retail poultry meat products. Methods Foodborne pathogens (Salmonella and S. aureus) were isolated from poultry meat and confirmed with the help of biochemical and immunological test. Antibiogram of the isolates were examined by following CLSI methods. Results A total number of 209 poultry meat samples were collected and studied in this study. Out of which, 5.26% were found contaminated with Salmonella while 18.18% were found contaminated with S. aureus. All the Salmonella and S. aureus isolates were found resistant to at least one antibiotic. About 72.72% of the Salmonella isolates showed resistance to tetracycline, while S. aureus isolates were also found highly resistant to tetracycline equal to 44.73%. One of the Salmonella isolates showed multi-drug resistance to almost six antibiotics out of nine antibiotics used in the study. Multidrug resistant S. aureus isolates were also found in the study. Conclusions The study confirmed the presence of Salmonella and S. aureus in retail poultry meat. It is a potential threat to consumer health. To reduce the risk of contamination, good hygiene practices are necessary from processing to storage. PMID:23593598

Ability of Cecal Cultures to Inhibit Growth of Salmonella Typhimurium during Aerobic Incubation

USDA-ARS?s Scientific Manuscript database

Introduction: Poultry can serve as reservoirs for Salmonella; however, chicks provided cultures of cecal bacteria develop resistance to colonization by Salmonella. Research has indicated that cecal bacteria metabolize organic acids to produce substances that inhibit Salmonella growth. Purpose: The...

Qualitative map of Salmonella contamination on the chicken carcass

USDA-ARS?s Scientific Manuscript database

Salmonella contamination of poultry is a global public health problem. The objective of this study was to map the distribution of Salmonella on the chicken carcass for the purpose of improving poultry inspection and food safety. Young chickens (n = 70) in the Cornish game hen class were obtained a...

Reveal Salmonella 2.0 test for detection of Salmonella spp. in foods and environmental samples. Performance Tested Method 960801.

PubMed

Hoerner, Rebecca; Feldpausch, Jill; Gray, R Lucas; Curry, Stephanie; Islam, Zahidul; Goldy, Tim; Klein, Frank; Tadese, Theodros; Rice, Jennifer; Mozola, Mark

2011-01-01

Reveal Salmonella 2.0 is an improved version of the original Reveal Salmonella lateral flow immunoassay and is applicable to the detection of Salmonella enterica serogroups A-E in a variety of food and environmental samples. A Performance Tested Method validation study was conducted to compare performance of the Reveal 2.0 method with that of the U.S. Department of Agriculture-Food Safety and Inspection Service or U.S. Food and Drug Administration/Bacteriological Analytical Manual reference culture methods for detection of Salmonella spp. in chicken carcass rinse, raw ground turkey, raw ground beef, hot dogs, raw shrimp, a ready-to-eat meal product, dry pet food, ice cream, spinach, cantaloupe, peanut butter, stainless steel surface, and sprout irrigation water. In a total of 17 trials performed internally and four trials performed in an independent laboratory, there were no statistically significant differences in performance of the Reveal 2.0 and reference culture procedures as determined by Chi-square analysis, with the exception of one trial with stainless steel surface and one trial with sprout irrigation water where there were significantly more positive results by the Reveal 2.0 method. Considering all data generated in testing food samples using enrichment procedures specifically designed for the Reveal method, overall sensitivity of the Reveal method relative to the reference culture methods was 99%. In testing environmental samples, sensitivity of the Reveal method relative to the reference culture method was 164%. For select foods, use of the Reveal test in conjunction with reference method enrichment resulted in overall sensitivity of 92%. There were no unconfirmed positive results on uninoculated control samples in any trials for specificity of 100%. In inclusivity testing, 102 different Salmonella serovars belonging to serogroups A-E were tested and 99 were consistently positive in the Reveal test. In exclusivity testing of 33 strains of non-salmonellae

O-Serotype Conversion in Salmonella Typhimurium Induces Protective Immune Responses against Invasive Non-Typhoidal Salmonella Infections.

PubMed

Li, Pei; Liu, Qing; Luo, Hongyan; Liang, Kang; Yi, Jie; Luo, Ying; Hu, Yunlong; Han, Yue; Kong, Qingke

2017-01-01

Salmonella infections remain a big problem worldwide, causing enteric fever by Salmonella Typhi (or Paratyphi) or self-limiting gastroenteritis by non-typhoidal Salmonella (NTS) in healthy individuals. NTS may become invasive and cause septicemia in elderly or immuno-compromised individuals, leading to high mortality and morbidity. No vaccines are currently available for preventing NTS infection in human. As these invasive NTS are restricted to several O-antigen serogroups including B1, D1, C1, and C2, O-antigen polysaccharide is believed to be a good target for vaccine development. In this study, a strategy of O-serotype conversion was investigated to develop live attenuated S . Typhimurium vaccines against the major serovars of NTS infections. The immunodominant O4 serotype of S . Typhimurium was converted into O9, O7, and O8 serotypes through unmarked chromosomal deletion-insertion mutations. O-serotype conversion was confirmed by LPS silver staining and western blotting. All O-serotype conversion mutations were successfully introduced into the live attenuated S . Typhimurium vaccine S738 (Δ crp Δ cya ) to evaluate their immunogenicity in mice model. The vaccine candidates induced high amounts of heterologous O-polysaccharide-specific functional IgG responses. Vaccinated mice survived a challenge of 100 times the 50% lethality dose (LD 50 ) of wild-type S . Typhimurium. Protective efficacy against heterologous virulent Salmonella challenges was highly O-serotype related. Furthermore, broad-spectrum protection against S . Typhimurium, S . Enteritidis, and S . Choleraesuis was observed by co-vaccination of O9 and O7 O-serotype-converted vaccine candidates. This study highlights the strategy of expressing heterologous O-polysaccharides via genetic engineering in developing live attenuated S . Typhimurium vaccines against NTS infections.

Modeling the survival of Salmonella Enteritidis and Salmonella Typhimurium during the fermentation of yogurt.

PubMed

Savran, Derya; Pérez-Rodríguez, Fernando; Halkman, A Kadir

2018-03-01

The objective of this study was to evaluate the behavior of Salmonella Enteritidis and Salmonella Typhimurium, the two most important serovars of salmonellosis , during the fermentation of yogurt. The microorganisms were enumerated in milk throughout the fermentation process at three initial inoculum levels (3, 5 and 7 log CFU/mL). DMFit software was used in the fitting procedure of the data (IFR, Norwich, UK, Version 3.5). The data provided sigmoidal curves that were successfully displayed with the Baranyi model. The results showed that the initial inoculum level did not affect the growth for both pathogens; thus, the µ max values (maximum specific growth rate) did not significantly differ across all the contamination levels, ranging from 0.26 to 0.38 for S. Enteritidis and from 0.50 to 0.56 log CFU/g/h for S. Typhimurium ( P > 0.05). However, the µ max values significantly differed between the two serovars ( P < 0.05). The λ values (lag time) did not have a clear trend in either of the pathogens. The present study showed that Salmonella can survive the fermentation process of milk even at a low contamination level. In addition, the models presented in this study can be used in quantitative risk assessment studies to estimate the threat to consumers.

Structural and enzymatic characterization of a host-specificity determinant from Salmonella

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Amanda C.; Spanò, Stefania; Galán, Jorge E.

The Salmonella effector protein GtgE functions as a cysteine protease to cleave a subset of the Rab-family GTPases and to prevent delivery of antimicrobial agents to the Salmonella-containing vacuole. GtgE is an effector protein from Salmonella Typhimurium that modulates trafficking of the Salmonella-containing vacuole. It exerts its function by cleaving the Rab-family GTPases Rab29, Rab32 and Rab38, thereby preventing the delivery of antimicrobial factors to the bacteria-containing vacuole. Here, the crystal structure of GtgE at 1.65 Å resolution is presented, and structure-based mutagenesis and in vivo infection assays are used to identify its catalytic triad. A panel of cysteine proteasemore » inhibitors were examined and it was determined that N-ethylmaleimide, antipain and chymostatin inhibit GtgE activity in vitro. These findings provide the basis for the development of novel therapeutic strategies to combat Salmonella infections.« less

Dynamics of Salmonella infection of macrophages at the single cell level.

PubMed

Gog, Julia R; Murcia, Alicia; Osterman, Natan; Restif, Olivier; McKinley, Trevelyan J; Sheppard, Mark; Achouri, Sarra; Wei, Bin; Mastroeni, Pietro; Wood, James L N; Maskell, Duncan J; Cicuta, Pietro; Bryant, Clare E

2012-10-07

Salmonella enterica causes a range of diseases. Salmonellae are intracellular parasites of macrophages, and the control of bacteria within these cells is critical to surviving an infection. The dynamics of the bacteria invading, surviving, proliferating in and killing macrophages are central to disease pathogenesis. Fundamentally important parameters, however, such as the cellular infection rate, have not previously been calculated. We used two independent approaches to calculate the macrophage infection rate: mathematical modelling of Salmonella infection experiments, and analysis of real-time video microscopy of infection events. Cells repeatedly encounter salmonellae, with the bacteria often remain associated with the macrophage for more than ten seconds. Once Salmonella encounters a macrophage, the probability of that bacterium infecting the cell is remarkably low: less than 5%. The macrophage population is heterogeneous in terms of its susceptibility to the first infection event. Once infected, a macrophage can undergo further infection events, but these reinfection events occur at a lower rate than that of the primary infection.

Assessing the potential impact of Salmonella vaccines in an endemically infected dairy herd

USDA-ARS?s Scientific Manuscript database

Salmonella spp. in cattle are contributing to bacterial foodborne disease for humans. Reduction of Salmonella prevalence in herds is important to prevent human Salmonella infections. Typical control measures are culling of infectious animals, vaccination, and improved hygiene management. Vaccines ha...

Environmental sampling to predict fecal prevalence of Salmonella in an intensively monitored dairy herd.

PubMed

Van Kessel, J S; Karns, J S; Wolfgang, D R; Hovingh, E; Jayarao, B M; Van Tassell, C P; Schukken, Y H

2008-10-01

Although dairy cattle are known reservoirs for salmonellae, cattle that are shedding this organism are often asymptomatic and difficult to identify. A dairy herd that was experiencing a sustained, subclinical outbreak of Salmonella enterica subsp. enterica Cerro was monitored for 2 years. Fecal samples from the lactating cows were collected every 6 to 8 weeks and tested for the presence of Salmonella. Fecal prevalence of Salmonella fluctuated throughout the observation period and ranged from 8 to 88%. Manure composites and water trough samples were collected along with the fecal samples, and bulk milk and milk filters were cultured for the presence of Salmonella on a weekly basis. Over 90% of the manure composites--representing high-animal-traffic areas-were positive at each sampling. Salmonella was detected in 11% of milk samples and in 66% of the milk filters. Results of weekly bulk milk quality testing (i.e., bulk tank somatic cell score, standard plate count, preliminary incubation count) were typically well within acceptable ranges. Milk quality variables had low correlations with herd Salmonella fecal prevalence. When observed over time, sampling period average prevalence of Salmonella in milk filters closely paralleled fecal prevalence of Salmonella in the herd. Based on results of this study, milk filters appear to be an effective method for monitoring shedding prevalence at the herd level. In-line filter testing is also a more sensitive measure of Salmonella, and perhaps other pathogens, in raw milk than testing the milk alone.

Analysis of Salmonella sp bacterial contamination on Vannamei Shrimp using binary logit model approach

NASA Astrophysics Data System (ADS)

Oktaviana, P. P.; Fithriasari, K.

2018-04-01

Mostly Indonesian citizen consume vannamei shrimp as their food. Vannamei shrimp also is one of Indonesian exports comodities mainstay. Vannamei shrimp in the ponds and markets could be contaminated by Salmonella sp bacteria. This bacteria will endanger human health. Salmonella sp bacterial contamination on vannamei shrimp could be affected by many factors. This study is intended to identify what factors that supposedly influence the Salmonella sp bacterial contamination on vannamei shrimp. The researchers used the testing result of Salmonella sp bacterial contamination on vannamei shrimp as response variable. This response variable has two categories: 0 = if testing result indicate that there is no Salmonella sp on vannamei shrimp; 1 = if testing result indicate that there is Salmonella sp on vannamei shrimp. There are four factors that supposedly influence the Salmonella sp bacterial contamination on vannamei shrimp, which are the testing result of Salmonella sp bacterial contamination on farmer hand swab; the subdistrict of vannamei shrimp ponds; the fish processing unit supplied by; and the pond are in hectare. This four factors used as predictor variables. The analysis used is Binary Logit Model Approach according to the response variable that has two categories. The analysis result indicates that the factors or predictor variables which is significantly affect the Salmonella sp bacterial contamination on vannamei shrimp are the testing result of Salmonella sp bacterial contamination on farmer hand swab and the subdistrict of vannamei shrimp ponds.

Heatwaves differentially affect risk of Salmonella serotypes.

PubMed

Milazzo, Adriana; Giles, Lynne C; Zhang, Ying; Koehler, Ann P; Hiller, Janet E; Bi, Peng

2016-09-01

Given increasing frequency of heatwaves and growing public health concerns associated with foodborne disease, we examined the relationship between heatwaves and salmonellosis in Adelaide, Australia. Poisson regression analysis with Generalised Estimating Equations was used to estimate the effect of heatwaves and the impact of intensity, duration and timing on salmonellosis and specific serotypes notified from 1990 to 2012. Distributed lag non-linear models were applied to assess the non-linear and delayed effects of temperature during heatwaves on Salmonella cases. Salmonella typhimurium PT135 notifications were sensitive to the effects of heatwaves with a twofold (IRR 2.08, 95% CI 1.14-3.79) increase in cases relative to non-heatwave days. Heatwave intensity had a significant effect on daily counts of overall salmonellosis with a 34% increase in risk of infection (IRR 1.34, 95% CI 1.01-1.78) at >41 °C. The effects of temperature during heatwaves on Salmonella cases and serotypes were found at lags of up to 14 days. This study confirms heatwaves have a significant effect on Salmonella cases, and for the first time, identifies its impact on specific serotypes and phage types. These findings will contribute to the understanding of the impact of heatwaves on salmonellosis and provide insights that could mitigate their impact. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Prevalence of gyrA Mutations in Nalidixic Acid-Resistant Strains of Salmonella Enteritidis Isolated from Humans, Food, Chickens, and the Farm Environment in Brazil.

PubMed

Campioni, Fábio; Souza, Roberto Antonio; Martins, Vinicius Vicente; Stehling, Eliana Guedes; Bergamini, Alzira Maria Morato; Falcão, Juliana Pfrimer

2017-06-01

Salmonella Enteritidis strains that are resistant to nalidixic acid and exhibit reduced susceptibility to fluoroquinolones have been increasing worldwide. In Brazil, few studies have been conducted to elucidate the quinolone resistance mechanisms of S. Enteritidis strains. This study analyzed the profile of gyrA, gyrB, parC, and parE mutations and plasmid-mediated quinolone resistance (PMQR) mechanisms in S. Enteritidis Nal R strains isolated in Brazil. Moreover, the minimum inhibitory concentrations (MICs) of ciprofloxacin were evaluated in 84 Nal R strains and compared with 20 Nal S strains. The mutation profiles of the gyrA gene were accessed by high-resolution melting analysis and gyrB, parC, and parE by quinolone resistance-determining region sequencing. The MICs of ciprofloxacin were accessed with Etest ® . The strains were divided into five gyrA melting profiles. The Nal R strains exhibited the following amino acid substitutions: Ser97→Pro, Ser83→Phe, Asp87→Asn, or Asp87→Tyr. The average MICs of ciprofloxacin was 0.006 μg/ml in the Nal S and 0.09 μg/ml in the Nal R strains. No points of mutation were observed in the genes gyrB, parC, and parE. The qnrB gene was found in two strains. In conclusion, the reduced susceptibility to ciprofloxacin observed in Nal R strains may cause treatment failures once this drug is commonly used to treat Salmonella infections. Moreover, this reduced susceptibility in these Brazilian strains was provided by target alteration of gene gyrA and not by mobile elements, such as resistance plasmids.

Salmonella detection in poultry samples. Comparison of two commercial real-time PCR systems with culture methods for the detection of Salmonella spp. in environmental and fecal samples of poultry.

PubMed

Sommer, D; Enderlein, D; Antakli, A; Schönenbrücher, H; Slaghuis, J; Redmann, T; Lierz, M

2012-01-01

The efficiency of two commercial PCR methods based on real-time technology, the foodproof® Salmonella detection system and the BAX® PCR Assay Salmonella system was compared to standardized culture methods (EN ISO 6579:2002 - Annex D) for the detection of Salmonella spp. in poultry samples. Four sample matrices (feed, dust, boot swabs, feces) obtained directly from poultry flocks, as well as artificially spiked samples of the same matrices, were used. All samples were tested for Salmonella spp. using culture methods first as the gold standard. In addition samples spiked with Salmonella Enteridis were tested to evaluate the sensitivity of both PCR methods. Furthermore all methods were evaluated in an annual ring-trial of the National Salmonella Reference Laboratory of Germany. Salmonella detection in the matrices feed, dust and boot swabs were comparable in both PCR systems whereas the results from feces differed markedly. The quality, especially the freshness, of the fecal samples had an influence on the sensitivity of the real-time PCR and the results of the culture methods. In fresh fecal samples an initial spiking level of 100cfu/25g Salmonella Enteritidis was detected. Two-days-dried fecal samples allowed the detection of 14cfu/25g. Both real- time PCR protocols appear to be suitable for the detection of Salmonella spp. in all four matrices. The foodproof® system detected eight samples more to be positive compared to the BAX® system, but had a potential false positive result in one case. In 7-days-dried samples none of the methods was able to detect Salmonella likely through letal cell damage. In general the advantage of PCR analyses over the culture method is the reduction of working time from 4-5 days to only 2 days. However, especially for the analysis of fecal samples official validation should be conducted according to the requirement of EN ISO6579:2002 - Annex D.

Survivability of Salmonella cells in popcorn after microwave oven and conventional cooking.

PubMed

Anaya, I; Aguirrezabal, A; Ventura, M; Comellas, L; Agut, M

2008-01-01

The survivability of Salmonella cells in popcorn preparation was determined for two distinct cooking methods. The first method used a standard microwave oven. The second method used conventional cooking in a pan. Prior to thermal processing in independent experiments, 12 suspensions in a range between 1x10(3) and 8x10(6) colony-forming units (CFU) per gram of Salmonella cells were inoculated in both raw microwave popcorn and conventional corn kernels. The influence of the initial concentration of Salmonella cells in the raw products and the lethal effects on Salmonella by thermal treatments for cooking were studied. Survival of Salmonella cells was determined in the thermally processed material by pre-enrichment and enrichment in selective medium, in accordance with the legislation for expanded cereals and cereals in flakes. Viable experimental contaminants were recovered from the conventionally cooked popcorn with initial inoculation concentrations of 9x10(4)cells/g or greater. Salmonella cell viability was significantly reduced after microwave oven treatment, with recoveries only from initial concentrations of 2x10(6)cells/g or superior.

Bacteriophage P22 to challenge Salmonella in foods.

PubMed

Zinno, Paola; Devirgiliis, Chiara; Ercolini, Danilo; Ongeng, Duncan; Mauriello, Gianluigi

2014-11-17

In this study we considered the influence of phage addition on the fate of Salmonella enterica serovar Typhimurium in different foods. Phage P22 was applied to the following: liquid eggs, energy drinks, whole and skimmed milk, apple juice, chicken breast and chicken mince all spiked with its host, whose growth was monitored for 24 and 48 h at 4 °C. Appreciable host inactivation, generally in the order of 2 log cycles, was achieved compared to phage-free controls in all food matrices when 10(4) UFC/g host inoculum was used. Furthermore, wild food strains belonging to the serotypes Typhimurium, Enteritidis, Derby Give, Newport, Muenchen and Muenster were assayed towards phage P22. Only isolates of Salmonella Typhimurium as well as Salmonella Derby and Salmonella Enteritidis was inhibited by the presence of P22 phage. Additional challenge experiments were carried out by spiking liquid-eggs, chicken breast and chicken mince with mixes of wild Salmonella Typhimurium (at concentration of about 10(4) UFC/g) strains along with their relative phage P22. The results showed a reduction of 2-3 log cycles after 48 h at 4 °C depending on both mix of strains and the specific food. Overall, the results indicate that phages may be useful in the control of food-borne pathogens. The food matrices considered, the liquid more than the solid, do not seem to affect the phage ability of infection compared to similar tests performed in vitro. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of four sampling methods for the detection of Salmonella in broiler litter.

PubMed

Buhr, R J; Richardson, L J; Cason, J A; Cox, N A; Fairchild, B D

2007-01-01

Experiments were conducted to compare litter sampling methods for the detection of Salmonella. In experiment 1, chicks were challenged orally with a suspension of naladixic acid-resistant Salmonella and wing banded, and additional nonchallenged chicks were placed into each of 2 challenge pens. Nonchallenged chicks were placed into each nonchallenge pen located adjacent to the challenge pens. At 7, 8, 10, and 11 wk of age the litter was sampled using 4 methods: fecal droppings, litter grab, drag swab, and sock. For the challenge pens, Salmonella-positive samples were detected in 3 of 16 fecal samples, 6 of 16 litter grab samples, 7 of 16 drag swabs samples, and 7 of 16 sock samples. Samples from the nonchallenge pens were Salmonella positive in 2 of 16 litter grab samples, 9 of 16 drag swab samples, and 9 of 16 sock samples. In experiment 2, chicks were challenged with Salmonella, and the litter in the challenge and adjacent nonchallenge pens were sampled at 4, 6, and 8 wk of age with broilers remaining in all pens. For the challenge pens, Salmonella was detected in 10 of 36 fecal samples, 20 of 36 litter grab samples, 14 of 36 drag swab samples, and 26 of 36 sock samples. Samples from the adjacent nonchallenge pens were positive for Salmonella in 6 of 36 fecal droppings samples, 4 of 36 litter grab samples, 7 of 36 drag swab samples, and 19 of 36 sock samples. Sock samples had the highest rates of Salmonella detection. In experiment 3, the litter from a Salmonella-challenged flock was sampled at 7, 8, and 9 wk by socks and drag swabs. In addition, comparisons with drag swabs that were stepped on during sampling were made. Both socks (24 of 36, 67%) and drag swabs that were stepped on (25 of 36, 69%) showed significantly more Salmonella-positive samples than the traditional drag swab method (16 of 36, 44%). Drag swabs that were stepped on had comparable Salmonella detection level to that for socks. Litter sampling methods that incorporate stepping on the sample

9 CFR 147.11 - Laboratory procedure recommended for the bacteriological examination of salmonella.

Code of Federal Regulations, 2014 CFR

2014-01-01

... procedure recommended for the bacteriological examination of salmonella. (a) For egg- and meat-type chickens... the bacteriological examination of salmonella. 147.11 Section 147.11 Animals and Animal Products... 25 birds, and birds from Salmonella enteritidis (SE) positive environments should be cultured in...

9 CFR 147.11 - Laboratory procedure recommended for the bacteriological examination of salmonella.

Code of Federal Regulations, 2012 CFR

2012-01-01

... procedure recommended for the bacteriological examination of salmonella. (a) For egg- and meat-type chickens... the bacteriological examination of salmonella. 147.11 Section 147.11 Animals and Animal Products... 25 birds, and birds from Salmonella enteritidis (SE) positive environments should be cultured in...

9 CFR 147.11 - Laboratory procedure recommended for the bacteriological examination of salmonella.

Code of Federal Regulations, 2011 CFR

2011-01-01

... procedure recommended for the bacteriological examination of salmonella. (a) For egg- and meat-type chickens... the bacteriological examination of salmonella. 147.11 Section 147.11 Animals and Animal Products... 25 birds, and birds from Salmonella enteritidis (SE) positive environments should be cultured in...

9 CFR 147.11 - Laboratory procedure recommended for the bacteriological examination of salmonella.

Code of Federal Regulations, 2013 CFR

2013-01-01

... procedure recommended for the bacteriological examination of salmonella. (a) For egg- and meat-type chickens... the bacteriological examination of salmonella. 147.11 Section 147.11 Animals and Animal Products... 25 birds, and birds from Salmonella enteritidis (SE) positive environments should be cultured in...

9 CFR 147.11 - Laboratory procedure recommended for the bacteriological examination of salmonella.

Code of Federal Regulations, 2010 CFR

2010-01-01

... procedure recommended for the bacteriological examination of salmonella. (a) For egg- and meat-type chickens... the bacteriological examination of salmonella. 147.11 Section 147.11 Animals and Animal Products... 25 birds, and birds from Salmonella enteritidis (SE) positive environments should be cultured in...

Fundamentals and applications of SERS-based bioanalytical sensing