... outbreaks of human Salmonella infections linked to backyard poultry. Get tips to help protect you and your ... Outbreaks of Human Salmonella Infections Linked to Live Poultry in Backyard Flocks Multistate Outbreak of Salmonella Virchow ...
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.
The problem of Salmonella in the global food chain and its current and projected repercussions on human health is cause for concern. Numerous studies have suggested that antimicrobial resistance among bacteria is on the rise and this has lead to changes in control and treatment strategies. Increas...
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...
Salmonella infection Overview By Mayo Clinic Staff Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are ...
... Case Count Maps Epi Curves Signs & Symptoms Key Resources Human Salmonella Infections Linked to Live Poultry Advice to ... Case Count Maps Epi Curves Signs & Symptoms Key Resources Human Salmonella Infections Linked to Small Turtles Human Salmonella ...
Avian Salmonella infections are important as both a cause of clinical disease in poultry and as a source of food-borne transmission of disease to humans. Host-adapted salmonellae (Salmonella enterica serovar Pullorum and Gallinarum) are responsible for severe systemic diseases, whereas numerous sero...
Eiguer, T; Caffer, M I
Throughout the years, Salmonella nomenclature has suffered continual revisions, due to the confusion created by the different criteria adopted by the several groups of researchers. At the present time, it is recognized that the genus Salmonella is a single species, composed by seven taxa, with the level of subspecies (subsp.), which can be divided into serovars, described in the Kauffmann-White scheme. The name of four the species type Salmonella is Salmonella enteral sp. nov. nom. rev. The serovar of the taxon I is designated, for instance, Salmonella subsp. I ser. Typhimurium. For the other taxa, less frequent in human or animal pathology, the name of the subsp., followed by the antigenic formula (e.g. Salmonella subsp. IV 50: b-) is used. This criterion has been validated by the International Committee of Systematic Bacteriology and the names of the serovars are included in the Approved Lists of Bacterial Names.
McAnearney, S; McCall, D
Salmonella infection can cause four predominant clinical syndromes: enteric fever, acute gastroenteritis, bacteraemia with or without metastatic infection, and the asymptomatic carrier state. Salmonella as an aetiological agent in osteomyelitis is essentially rare and salmonella osteomyelitis in itself is predominantly seen in patients with haemoglobinopathies such as sickle cell disease or thalassemia. There are very few cases reported in the literature in which salmonella osteomyelitis is seen in otherwise healthy individuals. We describe here a case of salmonella osteomyelitis in a young gentleman with no significant comorbidities who presented with fever and severe back pain, having returned from recent foreign travel. It is therefore important to consider uncommon pathogens in the differential diagnosis of travellers with prolonged fever and insidious symptoms.
... Old Feeding Your 1- to 2-Year-Old Salmonella Infections KidsHealth > For Parents > Salmonella Infections A A ... bathroom and before handling food in any way. Salmonella Basics Not everyone who ingests Salmonella bacteria will ...
... 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 ...
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...
... HUMAN SERVICES Food and Drug Administration Salmonella Contamination of Dry Dog Food; Withdrawal of...) entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food.'' This CPG is obsolete. DATES: The.... SUPPLEMENTARY INFORMATION: FDA issued the CGP entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog...
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...
Canals, Rocio; McClelland, Michael; Santiviago, Carlos A.; Andrews-Polymenis, Helene
Progress in the study of Salmonella survival, colonization, and virulence has increased rapidly with the advent of complete genome sequencing and higher capacity assays for transcriptomic and proteomic analysis. Although many of these techniques have yet to be used to directly assay Salmonella growth on foods, these assays are currently in use to determine Salmonella factors necessary for growth in animal models including livestock animals and in in vitro conditions that mimic many different environments. As sequencing of the Salmonella genome and microarray analysis have revolutionized genomics and transcriptomics of salmonellae over the last decade, so are new high-throughput sequencing technologies currently accelerating the pace of our studies and allowing us to approach complex problems that were not previously experimentally tractable.
... by chickens, cows, pigs, and reptiles (such as turtles, lizards, and iguanas). Another, rarer form — called Salmonella ... contact with a baby. Even healthy reptiles (especially turtles and iguanas) are not safe pets for small ...
Murray, C J
Salmonellae are part of the bacterial flora normally found in Man and animals, although the frequency of occurrence is variable, reflecting the general level of Salmonella in food, water and the environment. They are widely disseminated into environments which have been disturbed by human activities. Wildlife may harbour the organisms but do not appear to be a major conduit by which the organisms enter the human and animal food chain. In areas associated with Man, salmonellae in wild animals and birds reflect the serovars disseminated into the environment. Seasonal changes in infection occur, and the capacity of the organisms to survive in nature varies. Water plays an important role in the spread of the organisms to Man and animals. Control of salmonellae must start with a significant decrease in the number of organisms which are discharged into the environment.
Sfeir, Maroun; Youssef, Pierre; Mokhbat, Jacques E
Samonella typhi usually causes gastrointestinal infections. Few reports in the literature described skin and soft tissue infections related to Salmonella species, especially in immunocompetent patients. Our case exhibited sternal abscess growing Salmonella typhi.
Brockmann, Stefan O; Piechotowski, Isolde; Kimmig, Peter
In the context of an international outbreak of multiresistant Salmonella Typhimurium DT 104 that was correlated to the consumption of halvah ("helva," an Asian candy made from sesame seed), we examined several sesame seed products for the occurrence of Salmonella. Of 117 ready-to-eat food items containing sesame, we isolated salmonellae from 11 (9.4%) samples. In addition to finding Salmonella Typhimurium DT 104 in the halvah involved in the outbreak, we also isolated different Salmonella Typhimurium strains out of halvah from other manufacturers and countries of origin, as well as Salmonella Offa, Salmonella Tennessee, and Salmonella Poona from sesame paste (tahini) and sesame seed, which is sold for raw consumption in cereals.
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...the pediatric bacteriology laboratory of the UTMB Children’s Hospital and previously reported to prs-’uce the heat labile toxin (9). Salmonella
Tennant, Sharon M; Levine, Myron M
Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed Salmonella Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: Salmonella Typhi, Salmonella Paratyphi A, Salmonella Paratyphi B (currently uncommon but may become dominant again), Salmonella Typhimurium, Salmonella Enteritidis and Salmonella Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines.
Caffer, M I; Eiguer, T
A significant increase in the number of isolations of Salmonella enteritidis has been observed in Argentina since 1986. Outbreaks of foodborne diseases in humans were associated with the consumption of raw or undercooked hens' eggs. Between 1986 and the first 6 months of 1993 there were 150 outbreaks reported, affecting more than 6000 persons. A total of 71.3% of these outbreaks were confirmed by stool cultures, and 47.3% by bacteriological study of the food implicated in the outbreak. A permanent surveillance of salmonellosis is imperative, taking into account the persistence of Salmonella enteritidis isolations in sporadic cases and in new outbreaks.
Attachment and colonization of Salmonella enterica serovars to fresh produce leaves was investigated. Biofilm assay and attachment of Salmonella serovars to intact and cut leaves were determined. Salmonella Tennessee and Salmonella Thompson produced stronger biofilms compared to Salmonella Newpor...
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...
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...OVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (nd Subtitle) S. TYPE OF REPORT &PERIOD COVERED Pathogenesis of Salmonellosis : Salmonella... salmonellosis , One of the rapid, in vitro assays measures biological activity in terms of Salmonella toxin’s capacity to stimulate adenylate cyclase in Chinese
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...
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...
de ausencia la- Rp = propore6n de ]a poblacion que res- borall per enfermedad y los consiguientes ponimal cuestienano = R/P = 0,653 gastos en atena6n...medium for control . N b, 1/M’d. ,70;283:N%-73’). shipment of clinical sp cimens: i, fecal speci- mens. I Bactorii. 1964;88.%-98. 4. Huckstep RL Ty#Aoi *vi...1991: rence to salmonella: its epIdemkiog., pathoge- 3-.w nvsis and control . Clin ptGrtnet, . 1979;8:863. D Iulbwl 11 l., I Ikernng I.K. jfwvtrw ; i
Cox, N A
This paper reviews the numerous research studies carried out at Richard Russell Agricultural Research Center over the past 10 to 15 yr that ultimately led to the Center's present methods for the isolation of Salmonella from processed broiler carcasses and poultry feed. In addition, the newer technologies that have recently evolved are discussed in complete detail. Included in these discussions are the advantages and disadvantages of the various technologies along with recommendations for making them more useful to the practicing food or poultry microbiologist.
Dekker, John; Frank, Karen
Synopsis Salmonella, Shigella, and Yersinia cause a well-characterized spectrum of disease in humans, ranging from asymptomatic carriage to hemorrhagic colitis and fatal typhoidal fever. These pathogens are responsible for millions of cases of food-borne illness in the U.S. each year, with substantial costs measured in hospitalizations and lost productivity. In the developing world, illness caused by these pathogens is not only more prevalent, but is also associated with a greater case-fatality rate. Classical methods for identification rely on selective media and serology, but newer methods based on mass spectrometry and PCR show great promise for routine clinical testing. PMID:26004640
LaRock, Doris L; Chaudhary, Anu; Miller, Samuel I
Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.
Method 1682 describes procedures for analysis of solid samples (biosolids) and may be adapted for assessment of water, liquid, particulate and aerosol samples contaminated with Salmonella spp. using culture and immunoassay.
Pham, Oanh H; McSorley, Stephen J
Salmonella enterica serovars Typhi and Paratyphi are the causative agents of human typhoid fever. Current typhoid vaccines are ineffective and are not widely used in endemic areas. Greater understanding of host-pathogen interactions during Salmonella infection should facilitate the development of improved vaccines to combat typhoid and nontyphoidal Salmonellosis. This review will focus on our current understanding of Salmonella pathogenesis and the major host immune components that participate in immunity to Salmonella infection. In addition, recent findings regarding host immune mechanisms in response to Salmonella infection will be also discussed, providing a new perspective on the utility of improved tools to study the immune response to Salmonella infections.
Harvey, R. W.; Price, T. H.; Joynson, D. H.
Evidence of the presence of salmonellas in a paediatric ward, a special care baby unit, a maternity unit and a hospital kitchen was obtained by culture of sewer swabs, faeces and food samples. The survey was designed to cause as little administrative interference as possible. The technical aspects of the survey did not strain laboratory facilities. Minimal secondary spread of salmonella infection was experienced. PMID:390044
Finley, Rita; Ribble, Carl; Aramini, Jeff; Vandermeer, Meredith; Popa, Maria; Litman, Marcus; Reid-Smith, Richard
Twenty-eight research dogs were enrolled to determine the prevalence of salmonellae shedding after consumption of 1 Salmonella-contaminated commercial raw food diet meal. Sixteen dogs were exposed to Salmonella-contaminated commercial raw food diets and 12 to Salmonella-free commercial raw food diets. Seven of the exposed dogs shed salmonellae 1-7 days after consumption of Salmonella-contaminated raw food diets. None of the dogs fed Salmonella-free diets shed salmonellae. No clinical signs were observed in either group. Five of the 7 dogs shed the same serotypes as those recovered from food samples used for feeding. Results showed the same serotypes and antimicrobial resistance pattern in 2 of the 7 shedders. Dogs fed Salmonella-contaminated raw food diets can shed salmonellae and may, therefore, be a source of environmental contamination potentially leading to human or animal illness.
The detection of Salmonella in the edible internal contents of shell eggs provides the most incontrovertible and epidemiologically relevant evidence that laying flocks might threaten consumers. Accordingly, dependable tests for Salmonella in eggs remain essential for achieving public health objectiv...
Scheelings, T Franciscus; Lightfoot, Dianne; Holz, Peter
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.
Manning, Johanna; Gole, Vaibhav; Chousalkar, Kapil
Salmonellosis is a significant zoonotic disease which has a considerable economic impact on the egg layer industry. There is limited information about the prevalence of Salmonella spp. in backyard chickens. The current study was conducted to determine the prevalence of Salmonella in backyard chickens, and the associated virulence of any serovars identified. Hundred and fifteen pooled samples from 30 backyard flocks in South Australia were screened. Four flocks tested positive for Salmonella spp. The overall Salmonella isolation rate in the current study was 10.4%. The estimated prevalence at individual bird level was 0.02% (95% CI 0.025-0.975). The serovars isolated were Salmonella Agona, Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) and Salmonella Bovismorbificans. All Salmonella isolates tested positive for the prgH, orfL and spiC genes. The Salmonella subsp 2 ser 21:z10:z6 (Wandsbek) had the most antibiotic resistance, being resistant to ampicillin and cephalothin and having intermediate resistance to florphenicol. All of the Salmonella Agona had intermediate resistance to the ampicillin, while the Salmonella Bovismorbificans were susceptible to all antibiotics tested. With the increased interest of keeping backyard chickens, the current study highlights the zoonotic risk from Salmonella spp. associated with home flocks.
García, Cristina; Marín, Clara; Catalá-Gregori, Pablo; Soriano, Jose Miguel
Introducción: la salmonelosis es una enfermedad de alta prevalencia, siendo la búsqueda de herramientas preventivas para evitar la contaminación una prioridad a nivel de salud pública. Objetivo: en el presente trabajo se evaluó el efecto in vitro de bacteriófagos frente a Salmonella enteritidis como una herramienta de prevención. Método: se realizaron dos pruebas con tres concentraciones de bacteriófagos frente a dos cepas de Salmonella enteritidis inoculadas en muestras de heces frescas de gallinas ponedoras, y el correspondiente control positivo. Así, se testaron cuatro grupos en cada una de las dos pruebas. Cada grupo experimental contó con dos réplicas, y en cada réplica se incubaron tres placas. Las concentraciones ensayadas fueron tres: solución comercial (5 × 107 pfu/mL), y dos diluciones de la misma (1/10 y 1/30). Una de las cepas testada fue la cepa CECT 4300, cepa certificada de la Colección Española de Cultivo Tipo, y la otra una cepa de campo aislada en una explotación de ponedoras sacrificadas. Ambas cepas se inocularon en muestras de heces a la dosis de 1,3 × 105 ufc/g de heces en cada uno de los cuatro grupos. Se procedió con el aislamiento e identificación de la bacteria por ISO 6579 a varios tiempos desde la inoculación: 1 minuto, 24 h y 7 días. Resultados: en la primera prueba, con la cepa certificada, se aisló Salmonella en todos los grupos a tiempo 1 minuto. A las 24 h se aisló Salmonella en todos los grupos excepto en una de las réplicas tratada con la dilución 1/10 de bacteriófagos, en una de las placas de la otra réplica tratada con la dilución 1/10, y en dos placas de cada una de las dos réplicas tratadas con la solución comercial. A partir de los 7 días ya no se aisló la bacteria de ninguno de los grupos experimentales. En la segunda prueba, con la cepa de campo, se aisló Salmonella en todos los grupos a tiempo 1 minuto. A las 24 h se aisló Salmonella en todos los grupos excepto en una de las r
Foodborne pathogens are constantly adapting to circumvent intervention strategies. The ability to detect and overcome these adaptations are critical to ensure a safe food supply. We determined genotypic and/or phenotypic differences between Salmonella recovered from broiler chicks after comingling w...
Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.
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. Excellent 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.
enterobacteria . J. Bacteriol. 119:736-747. 48. Nozawa, R.T., T. Yokota, and S. Kuwahara. 1978. Assay method for Vibrio cholerae and Escherichia coli...and A. Nakamura. 1974. Enteropathogenic and enterotoxigenic activities on ligated gut loops in rabbits of Salmonella and some other enterobacteria
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...
... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry: Prevention of Salmonella... availability of a draft guidance entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation''...
Calo, Juliany Rivera; Park, Si Hong; Baker, Christopher A; Ricke, Steven C
Salmonella enterica is one of the most prevalent pathogens responsible for foodborne illness worldwide. Numerous Salmonella serovars have been associated with the consumption of a variety of products, and limiting food-borne illness due to Salmonella serovars is a continuing problem for food producers and public health. The emergence and prevalence of Salmonella serovars has been studied but the predominant serovars have varied somewhat over the years. The aims of this research were to compare the aerobic growth responses of selected predominant foodborne Salmonella serovars, and evaluate how the spent media from different serovars affects the growth of a well-characterized Salmonella Typhimurium strain. Growth responses were similar for most strains in spent media except for S. Typhimurium (ATCC 14028), which exhibited a decrease in growth in the presence of Salmonella Heidelberg (ARI-14) spent media. This research will provide a better understanding of the growth differences among several Salmonella serovars in nutrient limited spent media.
Poppe, C.; Irwin, R. J.; Messier, S.; Finley, G. G.; Oggel, J.
A nation-wide survey was conducted to estimate the prevalence of Salmonella enteritidis and other salmonellas among Canadian commercial broiler flocks. Environmental (litter and/or water) samples from 226 of 294 (76.9%) randomly selected flocks were contaminated with salmonellas. Litter samples were more often contaminated with salmonellas than water samples (47.4 v. 12.3%). Fifty different salmonella serovars were isolated. The most prevalent serovars were S. hadar, S. infantis, and S. schwarzengrund; they were isolated from samples of 98/294 (33.3%), 26/294 (8.8%), and 21/294 (7.1%) flocks, respectively. Feed samples of 39/290 (13.4%) flocks were contaminated with salmonellas. Salmonella enteritidis was isolated from the environmental samples of 9/294 (3.1%) flocks. Salmonella enteritidis phage type (PT) 8 was isolated from seven flocks, and PT 13a from two flocks. PMID:1879484
Tennant, Sharon M.; Levine, Myron M.
Salmonella enterica serovar Typhi produces significant morbidity and mortality worldwide despite the fact that there are licensed S. Typhi vaccines available. This is primarily due to the fact that these vaccines are not used in the countries that most need them. There is growing recognition that an effective invasive Salmonella vaccine formulation must also prevent infection due to other Salmonella serovars. We anticipate that a multivalent vaccine that targets the following serovars will be needed to control invasive Salmonella infections worldwide: S. Typhi, S. Paratyphi A, S. Paratyphi B (currently uncommon but may become dominant again), S. Typhimurium, S. Enteritidis and S. Choleraesuis (as well as other Group C Salmonella). Live attenuated vaccines are an attractive vaccine formulation for use in developing as well as developed countries. Here, we describe the methods of attenuation that have been used to date to create live attenuated Salmonella vaccines and provide an update on the progress that has been made on these vaccines. PMID:25902362
Sabag-Daigle, Anice; Blunk, Henry M; Gonzalez, Juan F; Steidley, Brandi L; Boyaka, Prosper N; Ahmer, Brian M M
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.
Sabag-Daigle, Anice; Blunk, Henry M.; Gonzalez, Juan F.; Steidley, Brandi L.; Boyaka, Prosper N.
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
Ma, Li; Zhang, Guodong; Gerner-Smidt, Peter; Mantripragada, Vijaya; Ezeoke, Ifeoma; Doyle, Michael P
The objective of this study was to determine the rates of thermal inactivation of three Salmonella Tennessee strains in peanut butter associated with an outbreak and to compare them to the rates of inactivation of Salmonella strains of other serotypes (Enteritidis, Typhimurium, and Heidelberg) (SSOS) and of clinical isolates of Salmonella Tennessee from sporadic cases (STSC). Commercial peanut butter was inoculated with Salmonella isolates and heated at 71, 77, 83, and 90 degrees C. The thermal inactivation curves were upwardly concave, indicating rapid death at the beginning (20 min) of heating followed by lower death rates thereafter. The first-order kinetics approach and nonlinear Weibull model were used to fit the inactivation curves and describe the rates of thermal inactivation of Salmonella in peanut butter. The calculated minimum times needed to obtain a 7-log reduction at 90 degrees C for the composited three outbreak-associated strains were significantly greater (P < 0.05) than those of SSOS and STSC. Approximately 120 min were needed to reduce the outbreak strains of Salmonella Tennessee by 7 log, whereas 86 and 55 min were needed for SSOS and STSC, respectively. These results indicate that the outbreak-associated Salmonella strains were more thermotolerant than the other Salmonella strains tested, and this greater thermal resistance was not serotype specific. Thermal treatments of peanut butter at 90 degrees C for less than 30 min are not sufficient to kill large populations (5 log CFU/g) of Salmonella in highly contaminated peanut butter.
Madajczak, Grzegorz; Dera-Tomaszewska, Bozena; Wasiak, Monika; Chróst, Anna; Szych, Jolanta
Two molecular biology methods were used to differentiate Salmonella enterica 1,4,,12:i:- strains: "Salmonella Check&Trace microarray" (CT) and multiplex PCR (mPCR). For 92 strains in CT result "Salmonella 1,4,,12:i:-" were obtained. Those strains were confirmed in mPCR as monophasic fljB-lack Salmonella Typhimurium. For 17 strains, which in CT assay were recognized as Salmonella Typhimurium, the same identification was obtained in mPCR. Reference Salmonella strains: Lagos, Agama, Tsevie, Glocester and Tumodi in CT were recognized as Salmonella genovar, in mPCR--as Salmonella O:4, H:i other than Salmonella Typhimurium, the same like Salmonella Farsta, recognized incorrectly in CT as Salmonella Typhimurium.
In many countries the incidence of human salmonella infections has markedly increased in recent years. To discuss recent developments and current understanding on the control of salmonella infections in animals, WHO organized a Consultation on the Control of Salmonella Infections in Animals: Prevention of Foodborne Salmonella Infections in Humans, held in Jena, Germany, on 21-26 November 1993. The present article summarizes the recommendations made by the participants on the pathoimmunogenesis, diagnosis, epidemiology, and control of salmonella infections and contaminations in animal production. PMID:7867127
m • . °° • ° . •• -. . .-.-.. .. °. . - J. the enteroatoxin produced by Vibrio cholerae . A significant degree of relatedness was shown between the...Columbia, Missouri on June 1, 1978. It has been "reviewed and accepted for publication in the American Journal of Clinical Nutrition , and we expect that... cholera toxin or Salmonella antisomatic serum, but it could be simulated by high concentrations of LPS from S. typhimurium. The appearance of the
The somatic and flagellar serum agglutinin titre were determined in paired samples obtained from seventy-seven cases of bovine abortion associated with Salmonella dublin infection. The cases could be divided into four serological groups with an active infection being demonstrated in most cases. The serum agglutination test was shown to be a relatively specific diagnostic test but was of more limited value in the retrospective identification of convalescent cases. PMID:4518345
A live, attenuated Salmonella enterica serovar Typhimurium vaccine was developed to confer broad protection against multiple Salmonella serovars to prevent disease and reduce pathogen colonization and shedding. Two vaccine trials were performed in swine to determine the protection afforded by the va...
Akil, Luma; Reddy, Remata S.
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
Many reviews have discussed Salmonella in poultry and suggested best practices to minimize this organism on raw poultry meat. Despite years of research and conscientious control efforts by industry and regulatory agencies, human salmonellosis rates have declined only modestly and Salmonella is stil...
Nontyphoidal Salmonella causes an estimated 1.4 million cases of human food-borne illness and more than 500 food-related human deaths in the United States annually. People infected with Salmonella, whether they experience typical symptoms of gastroenteritis and diarrhea or not, may be reservoirs fr...
Clyde, V L; Ramsay, E C; Bemis, D A
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.
Bej, A K; Mahbubani, M H; Boyce, M J; Atlas, R M
PCR DNA amplification of a region of the himA gene of Salmonella typhimurium specifically detected Salmonella spp. In oysters, 1 to 10 cells of Salmonella spp. were rapidly detected by the PCR following a pre-enrichment step to increase sensitivity and to ensure that detection was based on the presence of viable Salmonella spp. Images PMID:8117091
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial...
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial...
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and...
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and...
Hyeon, Ji-Yeon; Chon, Jung-Whan; Choi, In-Soo; Park, Chankyu; Kim, Dong-Eun; Seo, Kun-Ho
We developed and evaluated RNA aptamers to analyze their potential for use in detecting Salmonella Enteritidis. The selected aptamer was observed to specifically bind to Salmonella Enteritidis without any cross-reactivity to other Salmonella serovars. Thus, this study suggests that aptamers specific to Salmonella Enteritidis have a high potential for use in presumptive presumptive screening methods or alternative serotyping methods.
Andrews-Polymenis, Helene L.; Bäumler, Andreas J.; McCormick, Beth A.; Fang, Ferric C.
Salmonella infections continue to cause substantial morbidity and mortality throughout the world. However, recent discoveries and new paradigms promise to lead to novel strategies to diagnose, treat, and prevent Salmonella infections. This review provides an update of the Salmonella field based on oral presentations given at the recent 3rd ASM Conference on Salmonella: Biology, Pathogenesis and Prevention. PMID:20385760
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial...
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and...
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Salmonella Typhimurium Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.120 Salmonella Typhimurium Bacterin. Salmonella Typhimurium Bacterin shall be prepared from a culture of Salmonella typhimurium which has been inactivated and...
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Salmonella Choleraesuis Bacterin. 113... REQUIREMENTS Inactivated Bacterial Products § 113.122 Salmonella Choleraesuis Bacterin. Salmonella Choleraesuis Bacterin shall be prepared from a culture of Salmonella choleraesuis which has been inactivated and...
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Salmonella Dublin Bacterin. 113.123... Inactivated Bacterial Products § 113.123 Salmonella Dublin Bacterin. Salmonella Dublin Bacterin shall be prepared from a culture of Salmonella dublin which has been inactivated and is nontoxic. Each serial...
Lindhardt, Charlotte; Schönenbrücher, Holger; Slaghuis, Jörg; Bubert, Andreas; Ossmer, Rolf
Singlepath Salmonella is an immunochromatographic (lateral flow) assay for the presumptive qualitative detection of Salmonella spp. in food. A previous AOAC Performance Tested Method study evaluated Singlepath Salmonella as an effective method for the detection of Salmonella spp. in the following selected foods: dried skimmed milk, black pepper, dried pet food, desiccated coconut, cooked peeled frozen prawns, raw ground beef, and raw ground turkey. In this Emergency Response Validation extension, creamy peanut butter was inoculated with S. enterica. ser. Typhimurium. For low contamination level (1.08 CFU/25 g), a Chi-square value of 0.5 indicated that there was no significant difference between Singlepath Salmonella and the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) reference method. For high-level and uninoculated control there was 100% agreement between the methods.
Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe
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. PMID:25653644
Malik-Kale, Preeti; Jolly, Carrie E; Lathrop, Stephanie; Winfree, Seth; Luterbach, Courtney; Steele-Mortimer, Olivia
The Gram-negative bacterium Salmonella enterica has developed an array of sophisticated tools to manipulate the host cell and establish an intracellular niche, for successful propagation as a facultative intracellular pathogen. While Salmonella exerts diverse effects on its host cell, only the cell biology of the classic "trigger"-mediated invasion process and the subsequent development of the Salmonella-containing vacuole have been investigated extensively. These processes are dependent on cohorts of effector proteins translocated into host cells by two type III secretion systems (T3SS), although T3SS-independent mechanisms of entry may be important for invasion of certain host cell types. Recent studies into the intracellular lifestyle of Salmonella have provided new insights into the mechanisms used by this pathogen to modulate its intracellular environment. Here we discuss current knowledge of Salmonella-host interactions including invasion and establishment of an intracellular niche within the host.
Hsiao, Amber; Toy, Trevor; Marks, Florian
The interaction between schistosomiasis and Salmonella is a particularly important issue in Africa, where dual infection by the parasite and the bacterium are likely common. In this review, the ways in which schistosomiasis affects human biology as it relates to Salmonella are described. Those who are infected by both organisms experience reduced immunological functioning, exhibit irreversible organ damage due to prolonged schistosomiasis infection, and become latent carriers of Salmonella enterica serotypes Typhi and Paratyphi and S. Typhimurium. The sequestration of the bacteria in the parasite leads to ineffective antibiotic treatment because the bacteria cannot be completely killed, and lingering infection may then lead to antimicrobial resistance. These manifestations are likely not just for those dually infected but also for those first infected with schistosomes and, later, Salmonella. More data are needed to better understand dual infection, particularly as it may impact treatment and prevention of schistosomiasis and Salmonella in sub-Saharan Africa. PMID:27907208
Ibrahim, Hazem Mohammed; El-Moaty, Dalia Ahmed Mohammed Abd; Ahmed, Hanan Ali; El-Enbaawy, Mona Ibrahim
Aim: This work was conducted to study the phenotypic and genotypic characterization of locally isolated Salmonella strains (Salmonella Pullorum, Salmonella Enteritidis, and Salmonella Typhimurium) from poultry used in the preparation of Salmonella antigens in Egypt. Materials and Methods: The phenotypic characterization of Salmonella strains was done using standard microbiological, biochemical, and serological techniques. Molecular identification was done using different sets of primers on different genes using different polymerase chain reaction (PCR) techniques. Results: The phenotypic characterization of Salmonella strains was confirmed. Molecular identification revealed detection of 284 bp fragment of InvA gene in all studied Salmonella strains. Furthermore, multiplex PCR was used for more confirmation of being Salmonella spp., generally at 429 bp as well as genotyping of Salmonella Typhimurium and Salmonella Enteritidis at 559 and 312 bp, respectively, in one reaction. Conclusion: The locally isolated field Salmonella strains were confirmed phenotypically and genotypically to be Salmonella Enteritidis, and Salmonella Typhimurium and could be used for the preparation of Salmonella antigens. PMID:28096617
Bionda, Tihana; Behrends, Christian
Ubiquitination plays a critical role in the activation of host immune responses to infection and serves as a signal for pathogen delivery to phagophores along the xenophagy pathway. We recently performed systematic ubiquitination site profiling of epithelial cells infected with Salmonella Typhimurium. Our findings specifically highlight components of the NFKB, membrane trafficking pathways and RHO GTPase systems as ubiquitination hubs during infection. In addition, a broad spectrum of bacterial effectors and several outer membrane proteins are ubiquitinated in infected cells. This comprehensive resource of ubiquitinome dynamics during Salmonella infection enables further understanding of the complex host-pathogen interplay and may reveal novel targets for the inhibition of Salmonella invasion and inflammation.
Morrison, Christopher M; Armstrong, Alexandra E; Evans, Sanford; Mild, Rita M; Langdon, Christopher J; Joens, Lynn A
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
Kirchner, Miranda J; Liebana, Ernesto; McLaren, Ian; Clifton-Hadley, Felicity A; Wales, Andrew D; Davies, Robert H
To examine possible correlations in bovine Salmonella isolates between environmental survival and serovar-associated epidemiological patterns, bovine field isolates of Salmonella serovars Typhimurium and Dublin (two each) were inoculated into bovine faeces slurry and tested monthly by culture for survival during a six-month period of storage at a variable ambient temperature in a disused animal transporter. Low moisture conditions, where the slurry was dried onto wooden dowels, increased detectable survival of a low-level inoculum by up to five months, compared with wet slurry. A more modest increase of survival time was seen with storage of wet slurry under refrigeration at 4°C. Under both dry and wet conditions, the concentration of culturable Salmonella Typhimurium declined at a slower rate than did that of Salmonella Dublin. Salmonella that was naturally contaminating bovine faeces from farms with Salmonella Typhimurium did not show superior survival times compared with Salmonella Typhimurium that had been artificially inoculated into samples. The differing survival characteristics of the two serovars that was observed in environmental faeces may complement their different modes of infection in cattle. Salmonella Dublin, being a bovine host-adapted strain that establishes chronic infection in some animals, may have less need to survive for a prolonged period outside of its host than does Salmonella Typhimurium.
Pei, Yanlong; Parreira, Valeria R; Roland, Kenneth L; Curtiss, Roy; Prescott, John F
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.
Lukac, Maja; Pedersen, Karl; Prukner-Radovcic, Estella
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.
Phan, Tran Thi; Khai, Ly Thi Lien; Ogasawara, Natsue; Tam, Nguyen Thu; Okatani, Alexandre Tomomitsu; Akiba, Masato; Hayashidani, Hideki
From March 2000 to September 2001, 608 samples of retail meat (136 pork, 70 beef, 202 chicken, and 200 ducks) and 110 samples of retail shrimp from six provinces of the Mekong Delta in Vietnam were collected individually and examined for the prevalence of Salmonella. Of the 718 samples examined, 243 (33.8%) were Salmonella positive. Salmonella was isolated from 69.9% of the pork samples, 48.6% of the beef samples, 21.0% of the chicken meat samples, 22.3% of the duck meat samples, and 24.5% of the shrimp samples. From 261 Salmonella isolates, 24 different serovars were identified. The predominant serovars of the isolates were Salmonella Derby, Salmonella Weltevreden, and Salmonella London in pork; Salmonella Weltevreden, Salmonella London, and Salmonella Dessau in beef; Salmonella Emek, Salmonella Typhimurium, and Salmonella Dessau in chicken meat; Salmonella Lexington, Salmonella Derby, and Salmonella Dessau in duck meat; and Salmonella Weltevreden, Salmonella Tennessee, and Salmonella Dessau in shrimps. Salmonella Bovismorbificans, Salmonella Derby, Salmonella Dessau, and Salmonella Weltevreden were the most common serovars in all the samples examined. These results indicate a high rate of contamination by Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam.
Song, Won-Jae; Kang, Dong-Hyun
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.
The survival of four Salmonella strains in river water microcosms was monitored using culturing techniques, direct counts, whole cell hybridization, scanning electron microscopy, and resuscitation techniques via the direct viable count method and flow cytrometry. Plate counts of...
The survival of four Salmonella strains in river water microcosms was monitored by culturing techniques, direct counts, whole-cell hybridization, scanning electron microscopy, and resuscitation techniques via the direct viable count method and flow cytometry. Plate counts of bact...
Olariu, Adina; Jain, Sangita; Gupta, Ajay Kumar
A 23-day-old male baby was admitted with 1 day history of high temperature, irritability and poor feeding. His general examination was unremarkable. Salmonella species grew from CSF culture and subsequent identification revealed Salmonella kingabwa, a serotype which rarely causes human illness. The child lived with his parents and regularly visited his grandmother for 4 h every day. Grandmother kept five snakes and five water dragons as pets. They lived in tanks and crawled freely around the house. For decades the reptiles have been known to carry Salmonella, which can be transmitted directly or indirectly to humans through ingestion of the bacteria, which causes subsequent infection. Reptile exposure is a rare but significant risk factor for Salmonella illness in England and contact with reptiles should be avoided by children less than 5 years old, pregnant ladies, older and those with impaired immunity.
Current federal regulations required monitoring for fecal coliforms or Salmonella in biosolids destined for land application. Standard protocols designed to quantify these organisms in water or wastewater were identified and specified in these regulations. However, proto...
Lerner, Mitchell B.; Goldsmith, Brett R.; McMillon, Ronald; Dailey, Jennifer; Pillai, Shreekumar; Singh, Shree R.; Johnson, A. T. Charlie
Antibody-functionalized carbon nanotube devices have been suggested for use as bacterial detectors for monitoring of food purity in transit from the farm to the kitchen. Here we report progress towards that goal by demonstrating specific detection of Salmonella in complex nutrient broth solutions using nanotube transistors functionalized with covalently-bound anti-Salmonella antibodies. The small size of the active device region makes them compatible with integration in large-scale arrays. We find that the on-state current of the transistor is sensitive specifically to the Salmonella concentration and saturates at low concentration (<1000 cfu/ml). In contrast, the carrier mobility is affected comparably by Salmonella and other bacteria types, with no sign of saturation even at much larger concentrations (108 cfu/ml).
Schikora, Adam; Virlogeux-Payant, Isabelle; Bueso, Eduardo; Garcia, Ana V; Nilau, Theodora; Charrier, Amélie; Pelletier, Sandra; Menanteau, Pierrette; Baccarini, Manuela; Velge, Philippe; Hirt, Heribert
Salmonella virulence in animals depends on effectors injected by Type III Secretion Systems (T3SSs). In this report we demonstrate that Salmonella mutants that are unable to deliver effectors are also compromised in infection of Arabidopsis thaliana plants. Transcriptome analysis revealed that in contrast to wild type bacteria, T3SS mutants of Salmonella are compromised in suppressing highly conserved Arabidopsis genes that play a prominent role during Salmonella infection of animals. We also found that Salmonella originating from infected plants are equally virulent for human cells and mice. These results indicate a high degree of conservation in the defense and infection mechanism of animal and plant hosts during Salmonella infection.
Saheer, S; Immanuel, Subash; Balamugesh, T; Christopher, D J
A 21-year-old boy presented with high grade fever, diffuse chest pain and exertional breathlessness of one month duration. Radiologically he had a large lobulated anterior mediastinal mass with necrotic thick enhancing septaes. Histopathology of the mass was suggestive of thymoma and culture from the necrotic aspirate yielded Salmonella typhi. The same pathogen was isolated in subsequent blood and sputum cultures. This current report describes the rare association of salmonella infection with thymoma.
Harish, Belgode N; Menezes, Godfred A
Infections with Salmonella are an important public health problem worldwide. Salmonella are one of the most common causes of food-borne illness in humans. There are many types of Salmonella but they can be divided into two broad categories: those that cause typhoid and those that do not. The typhoidal Salmonella (TS), such as S. enterica subsp. enterica serovars Typhi and S. Paratyphi only colonize humans and are usually acquired by the consumption of food or water contaminated with human fecal material. The much broader group of non-typhoidal Salmonella (NTS) usually results from improperly handled food that has been contaminated by animal or human fecal material. Antimicrobials are critical to the successful outcome of invasive Salmonella infections and enteric fever. Due to resistance to the older antimicrobials, ciprofloxacin [fluoroquinolone (FQ)] has become the first-line drug for treatment. Nevertheless, switch to FQ has led to a subsequent increase in the occurrence of salmonellae resistant to this antimicrobial agent. The exact mechanism of this FQ resistance is not fully understood. FQ resistance has driven the use of third-generation cephalosporins and azithromycin. However, there are sporadic worldwide reports of high level resistance to expanded-spectrum cephalosporins (such as ceftriaxone) in TS and in NTS it has been recognized since 1988 and are increasing in prevalence worldwide. Already there are rare reports of azithromycin resistance leading to treatment failure. Spread of such resistance would further greatly limit the available therapeutic options, and leave us with only the reserve antimicrobials such as carbapenem and tigecycline as possible treatment options. Here, we describe the methods involved in the genotypic characterization of antimicrobial resistance in clinical isolates of salmonellae.
Maradiaga, Martha; Miller, Mark F; Thompson, Leslie; Pond, Ansen; Gragg, Sara E; Echeverry, Alejandro; Garcia, Lyda G; Loneragan, Guy H; Brashears, Mindy M
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.
Hancock, Dale D.; Roozen, Paivi M.; Szymanski, Maryanne H.; Scheenstra, Beth C.; Cady, Kirsten M.; Besser, Thomas E.; Chudek, Paul A.
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
Li, Haiping; Bhaskara, Anuhya; Megalis, Christina; Tortorello, Mary Lou
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.
Yu, Hong B; Croxen, Matthew A; Marchiando, Amanda M; Ferreira, Rosana B R; Cadwell, Ken; Foster, Leonard J; Finlay, B Brett
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. IMPORTANCE As a host defense system, autophagy is known to target a population of Salmonella for degradation and hence restricting Salmonella replication. In contrast to this concept, a recent report showed that knockdown of Rab1, a GTPase required for autophagy of Salmonella, decreases Salmonella replication in HeLa cells. Here, we have reexamined the fate of Salmonella targeted by autophagy by various cell biology-based assays. We found that the association of autophagy components with cytosolic Salmonella increases shortly after initiation of intracellular bacterial replication. Furthermore, through a live-cell imaging method, a subset of cytosolic Salmonella was found to be extensively associated with autophagy components p62 and/or LC3, and they replicated quickly. Most importantly, depletion of autophagy components significantly reduced the replication of cytosolic Salmonella in HeLa cells. Hence, in contrast to previous reports, we propose
Transmission of Salmonella to broiler chicks with Salmonella colonized darkling beetles or larvae was evaluated by sampling litter and ceca during growout. In two trials, 1 or 2 day-of-hatch broiler chicks (in a pen of 40) were gavaged with either 4 darkling beetles, 4 beetle larvae, or 0.1 mL pept...
Casanova-Higes, A; Andrés-Barranco, S; Mainar-Jaime, R C
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.
... Tweet Share Compartir Salmonella can contaminate more than poultry and eggs. It sneaks its way into many ... of foods, not just from eggs and undercooked poultry. Although poultry and eggs are primary culprits, Salmonella ...
... Contaminants Buy, Store & Serve Safe Food Enjoying Homemade Ice Cream without the Risk of Salmonella Infection Share Tweet ... it Email Print August 2004 Every year homemade ice cream causes several outbreaks of Salmonella infection with up ...
... What's this? Submit Button Past Emails CDC Features Salmonella and Eggs Recommend on Facebook Tweet Share Compartir ... can I reduce my chance of getting a Salmonella infection? Keep eggs refrigerated at 40Â°F (4Â° ...
Elemfareji, Omar Ismail; Thong, Kwai Lin
Members of Salmonella enterica are important foodborne pathogens of significant public health concern worldwide. This study aimed to determine a range of virulence genes among typhoidal (S. typhi) and non-typhoidal (S. enteritidis) strains isolated from different geographical regions and different years. A total of 87 S. typhi and 94 S. enteritidis strains were tested for presence of 22 virulence genes by employing multiplex PCR and the genetic relatedness of these strains was further characterized by REP-PCR. In S. typhi, invA, prgH, sifA, spiC, sopB, iroN, sitC, misL, pipD, cdtB, and orfL were present in all the strains, while sopE, agfC, agfA, sefC, mgtC, and sefD were present in 98.8, 97.7, 90.8, 87.4, 87.4 and 17.2 %, of the strains, respectively. No lpfA, lpfC, pefA, spvB, or spvC was detected. Meanwhile, in S. enteritidis, 15 genes, agfA, agfC, invA, lpfA, lpfC, sefD, prgH, spiC, sopB, sopE, iroN, sitC, misL, pipD, and orfL were found in all S. enteritidis strains 100 %, followed by sifA and spvC 98.9 %, pefA, spvB and mgtC 97.8 %, and sefC 90.4 %. cdtB was absent from all S. enteritidis strains tested. REP-PCR subtyped S. typhi strains into 18 REP-types and concurred with the virulotyping results in grouping the strains, while in S. enteritidis, REP-PCR subtyped the strains into eight profiles and they were poorly distinguishable between human and animal origins. The study showed that S. typhi and S. enteritidis contain a range of virulence factors associated with pathogenesis. Virulotyping is a rapid screening method to identify and profile virulence genes in Salmonella strains, and improve an understanding of potential risk for human and animal infections.
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...
Malt, Layla M; Perrett, Charlotte A; Humphrey, Suzanne; Jepson, Mark A
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.
Crowley, Erin; Bird, Patrick; Fisher, Kiel; Goetz, Katherine; Benzinger, M Joseph; Agin, James; Goins, David; Johnson, Ronald L
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.
Finishing pigs infected with Salmonella pose significant food safety risks by carrying the pathogen into abattoirs. A study was conducted to determine the dynamic of Salmonella infection in finishing pigs, and the immunological alterations that occur in Salmonella-carrier pigs, by longitudinally com...
Salmonella is an important food bourn pathogen capable of infecting both humans and animals. One of the most effective treatments for Salmonella infections is beta-lactam antibiotics, particularly extended spectrum beta-lactams; however, Salmonella resistant to these antibiotics have been recovered ...
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...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...
Jardine, Claire; Reid-Smith, Richard J; Janecko, Nicol; Allan, Mike; McEwen, Scott A
Numerous serotypes of Salmonella have been detected in a variety of wild animals, including raccoons (Procyon lotor). Raccoons are common, mid-size omnivores that live in close association with people in urban and rural areas in Ontario. Although raccoons are known to shed Salmonella, little is known about their potential long-term role in maintaining Salmonella infections. We sampled feces from raccoons in three areas of Ontario: one primarily urban site around Niagara, one primarily rural site north of Guelph, and the grounds of the Toronto Zoo, in 2007 to identify which serotypes of Salmonella were commonly shed by raccoons in southern Ontario. In addition, we conducted a longitudinal study at the Toronto Zoo site to determine if raccoons remain persistently infected with Salmonella. Salmonella was found in 45% of samples. The prevalence of Salmonella in raccoon feces ranged from 27% at the rural site to 65% at the urban site. We detected 16 serotypes of Salmonella in 83 positive samples. The most common serotype detected in raccoons from the rural and zoo sites was Salmonella enterica serotype Typhimurium, whereas Salmonella Newport was detected most commonly in the urban site. Only one raccoon of 11 that were captured in four or more consecutive trapping sessions shed the same Salmonella serotype for two consecutive months, suggesting that raccoons regularly acquire new Salmonella serotypes from the environment.
... HUMAN SERVICES Food and Drug Administration Guidance for Industry: Prevention of Salmonella Enteritidis... availability of a guidance for industry entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During... with certain provisions contained in FDA's final rule ``Prevention of Salmonella Enteritidis in...
... 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...
... HUMAN SERVICES Food and Drug Administration 21 CFR Part 500 Animal Feeds Contaminated With Salmonella... Administration (FDA or Agency) is revoking an advisory opinion on animal feeds contaminated with Salmonella... enforcement strategy articulated in a final compliance policy guide (CPG) on Salmonella in food for...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Salmonella spp. serological reagents. 866.3550... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3550 Salmonella spp. serological reagents. (a) Identification. Salmonella spp. serological reagents are devices...
Garty, I.; Koren, A.
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.
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...
Whiley, Harriet; Ross, Kirstin
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.
Whiley, Harriet; Ross, Kirstin
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
Owen, Drew; Ballard, Matthew; Mills, Zachary; Hanasoge, Srinivas; Hesketh, Peter; Alexeev, Alexander
Using three-dimensional simulations and experiments, we examine capture of salmonella from a complex fluid sample flowing through a microfluidic channel. Capture is performed using orbiting magnetic microbeads, which can easily be extracted from the system for analysis after salmonella capture. Numerical simulations are used to model the dynamics of the system, which consists of a microchannel filled with a viscous fluid, model salmonella, magnetic microbeads and a series of angled parallel ridges lining the top of the microchannel. Simulations provide a statistical measure of the ability of the system to capture target salmonella. Our modeling findings guide the design of a lab-on-a-chip experimental device to be used for the detection of salmonella from complex food samples, allowing for the detection of the bacteria at the food source and preventing the consumption of contaminated food. Such a device can be used as a generic platform for the detection of a variety of biomaterials from complex fluids. This work is supported by a grant from the United States Department of Agriculture.
As the leading cause of bacterial foodborne disease in the U.S., Salmonella is a major food safety concern. Endeavors to control Salmonella in our food chain are hindered by the ability of Salmonella to sub-clinically colonize livestock, thereby serving as a significant reservoir for contamination ...
Controlling Salmonella in the food chain is complicated by the ability of Salmonella to sub-clinically colonize livestock. These Salmonella-carrier animals are a significant reservoir for contamination of naïve animals, the environment, and our food supply. On the farm and in experimental infections...
To evaluate the impact of litter Salmonella status during feed withdrawal, 2 pens of 5-wk-old broilers (n=10/pen) in separate rooms were challenged with marker strains of either Salmonella Montevideo (nalidixic acid resistant) or Salmonella Heidelberg (streptomycin resistant) by oral gavage. Three ...
Maddocks, Susan; Olma, Tom; Chen, Sharon
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
Gantois, Inne; Ducatelle, Richard; Timbermont, Leen; Boyen, Filip; Bohez, Lotte; Haesebrouck, Freddy; Pasmans, Frank; van Immerseel, Filip
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.
de Freitas Neto, Oliveiro Caetano; Mesquita, Aline Lopes; de Paiva, Jaqueline Boldrin; Zotesso, Fábio; Berchieri Júnior, Angelo
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
Poppe, C; McFadden, K A; Brouwer, A M; Demczuk, W
A study was conducted to characterize 318 Salmonella enteritidis strains that were mainly isolated from poultry and their environment in Canada. Biotype, phagetype (PT), plasmid profile (PP), hybridization with a plasmid-derived virulence sequence probe, antibiotic resistance, outer membrane proteins (OMPs), and lipopolysaccharide (LPS) profiles were determined. Relationships of these properties to one another, and their diagnostic and pathogenic significance were assessed. Biotyping indicated that failure to ferment rhamnose was sometimes useful as a marker for epidemiologically related strains. Phagetyping was the most effective method for subdividing S. enteritidis; it distinguished 12 PTs. Phagetype 13 was occasionally associated with septicemia and mortality in chickens. The strains belonged to 15 PPs. A 36 megadalton (MDa) plasmid was found in 97% of the strains. Only the 36 MDa plasmid hybridized with the probe. Seventeen percent of the strains were drug resistant; all strains were sensitive to ciprofloxacin. Thirty-five of 36 strains possessed the same OMP profile, and 36 of 41 strains contained smooth LPS. Images Fig. 1. PMID:8358678
Dillon, D.; Combes, R.; McConville, M.; Zeiger, E. )
Ozone is a highly reactive gas that has been tested for genotoxicity in a number of systems. Induced genetic damage resulting from ozone treatment may not be readily observed because of the high toxicity of the chemical and difficulties in generating and administering controlled concentrations. The mutagenicity of ozone was investigated in Salmonella typhimurium using a plate test protocol designed for reactive vapours and gases. Ozone, at two to three consecutive doses, induced weak, albeit statistically significant, mutagenic responses in tester strain TA102 with and without Aroclor-induced rat liver S9 (lowest effective mean concentration of 0.019 ppm; 35 min total exposure). However, dose-related responses were not always obtained. No mutagenicity was detected in strains TA98, TA100, or TA1535, with or without S9. In strain TA104, ozone induced a weak response only at a single dose with S9; this response was not reproducible. Mutagenicity was dependent on the ozone flow rate and total exposure time, with variations in the optimum dose-time regimen leading to toxicity or complete inactivity. The data show that ozone is a very weak bacterial mutagen and only when tested under narrowly prescribed, subtoxic dosing conditions.
Chua, Ying Ying; Chen, John L. T.
Salmonella vertebral osteomyelitis is an uncommon complication of Salmonella infection. We report a case of a 57-year-old transgender male who presented with lower back pain for a period of one month following a fall. Physical examination only revealed tenderness over the lower back with no neurological deficits. MRI of the thoracic and lumbar spine revealed a spondylodiscitis at T10-T11 and T12-L1 and right posterior epidural collection at the T9-T10 level. He underwent decompression laminectomy with segmental instrumentation and fusion of T8 to L3 vertebrae. Intraoperatively, he was found to have acute-on-chronic osteomyelitis in T10 and T11, epidural abscess, and discitis in T12-L1. Tissue and wound culture grew Salmonella Typhi and with antibiotics susceptibility guidance he was treated with intravenous ceftriaxone for a period of six weeks. He recovered well with no neurological deficits. PMID:27034871
Sedlock, D M; Koupal, L R; Deibel, R H
By using a strain of Salmonella typhimurium, we detected the presence of an enterotoxin, as determined by the rabbit ileal loop assay, in various complex and defined media. The enterotoxin was concentrated by ultrafiltration of culture supernatant fluids and eluted in and adjacent to the void volume of a Sephadex G-100 column. This suggested that the enterotoxic factor was of a relatively high molecular weight, and additional evidence indicated it was heterogeneous in size. Further chromatography, using a diethylaminoethyl-cellulose anion exchanger, facilitated at least a 50-fold purification of the Salmonella enterotoxin. PMID:352941
Park, U E; Roth, J R; Olivera, B M
NAD can serve as both a purine and a pyridine source for Salmonella typhimurium. Exogenous NAD is rapidly broken down into nicotinamide mononucleotide and AMP by an NAD pyrophosphatase, the first step in the pathway for the assimilation of exogenous NAD. We isolated and characterized mutants of S. typhimurium lacking NAD pyrophosphatase activity; such mutants were identified by their failure to use exogenous NAD as a purine source. These mutants carry mutations that map at a new locus, designated pnuE, between 86 and 87 min on the Salmonella chromosome. PMID:2841298
Shuai-Cheng, Wu; Ben-Dong, Fu; Xiu-Ling, Chu; Jian-Qing, Su; Yun-Xing, Fu; Zhen-Qiang, Cui; Dao-Xiu, Xu; Zong-Mei, Wu
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.
Kallapura, G; Morgan, M J; Pumford, N R; Bielke, L R; Wolfenden, A D; Faulkner, O B; Latorre, J D; Menconi, A; Hernandez-Velasco, X; Kuttappan, V A; Hargis, B M; Tellez, G
Experimental and epidemiological evidence suggests that primary infection of Salmonella is by the oral-fecal route for poultry. However, the airborne transmission of Salmonella and similar enteric zoonotic pathogens has been historically neglected. Increasing evidence of Salmonella bioaerosol generation in production facilities and studies suggesting the vulnerabilities of the avian respiratory architecture together have indicated the possibility of the respiratory system being a potential portal of entry for Salmonella in poultry. Presently, we evaluated this hypothesis through intratracheal (IT) administration of Salmonella Enteritidis and Salmonella Typhimurium, as separate challenges, in a total of 4 independent trials, followed by enumeration of cfu recovery in ceca-cecal tonsils and recovery incidence in liver and spleen. In all trials, both Salmonella Enteritidis and Salmonella Typhimurium, challenged IT colonized cecae to a similar or greater extent than oral administration at identical challenge levels. In most trials, chickens cultured for cfu enumeration from IT-challenged chicks at same dose as orally challenged, resulted in an increase of 1.5 log higher Salmonella Enteritidis from ceca-cecal tonsils and a much lower dose IT of Salmonella Enteritidis could colonize ceca to the same extent than a higher oral challenge. This trend of increased cecal colonization due to IT challenge was observed with all trails involving week-old birds (experiment 2 and 3), which are widely considered to be more difficult to infect via the oral route. Liver-spleen incidence data showed 33% of liver and spleen samples to be positive for Salmonella Enteritidis administered IT (10(6) cfu/chick), compared with 0% when administered orally (experiment 2, trial 1). Collectively, these data suggest that the respiratory tract may be a largely overlooked portal of entry for Salmonella infections in chickens.
Kallapura, G.; Morgan, M. J.; Pumford, N. R.; Bielke, L. R.; Wolfenden, A. D.; Faulkner, O. B.; Latorre, J. D.; Menconi, A.; Hernandez-Velasco, X.; Kuttappan, V. A.; Hargis, B. M.; Tellez, G.
Experimental and epidemiological evidence suggests that primary infection of Salmonella is by the oral-fecal route for poultry. However, the airborne transmission of Salmonella and similar enteric zoonotic pathogens has been historically neglected. Increasing evidence of Salmonella bioaerosol generation in production facilities and studies suggesting the vulnerabilities of the avian respiratory architecture together have indicated the possibility of the respiratory system being a potential portal of entry for Salmonella in poultry. Presently, we evaluated this hypothesis through intratracheal (IT) administration of Salmonella Enteritidis and Salmonella Typhimurium, as separate challenges, in a total of 4 independent trials, followed by enumeration of cfu recovery in ceca-cecal tonsils and recovery incidence in liver and spleen. In all trials, both Salmonella Enteritidis and Salmonella Typhimurium, challenged IT colonized cecae to a similar or greater extent than oral administration at identical challenge levels. In most trials, chickens cultured for cfu enumeration from IT-challenged chicks at same dose as orally challenged, resulted in an increase of 1.5 log higher Salmonella Enteritidis from ceca-cecal tonsils and a much lower dose IT of Salmonella Enteritidis could colonize ceca to the same extent than a higher oral challenge. This trend of increased cecal colonization due to IT challenge was observed with all trails involving week-old birds (experiment 2 and 3), which are widely considered to be more difficult to infect via the oral route. Liver-spleen incidence data showed 33% of liver and spleen samples to be positive for Salmonella Enteritidis administered IT (106 cfu/chick), compared with 0% when administered orally (experiment 2, trial 1). Collectively, these data suggest that the respiratory tract may be a largely overlooked portal of entry for Salmonella infections in chickens. PMID:24570455
Olstein, Alan; Griffith, Leena; Feirtag, Joellen; Pearson, Nicole
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.
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
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
Poppe, C; Johnson, R P; Forsberg, C M; Irwin, R J
Seven Canadian layer flocks with Salmonella enteritidis in their environment were investigated to determine the numbers of hens infected with S. enteritidis, the localization of S. enteritidis in organs of infected hens and the numbers of S. enteritidis-infected eggs produced by two affected flocks. By a microagglutination test (MAT) using S. pullorum antigens, these flocks had more seropositive hens (mean 51.9 +/- 16.9%) than two Salmonella-free flocks (mean 13.0 +/- 4.2%). Culture of tissues of 580 hens (433 seropositive) from the seven flocks detected 26 (4.5%) S. enteritidis-infected hens from two flocks. In one flock, 2/150 hens were infected with S. enteritidis phage type (PT) 8, which was confined to the ceca, and no Salmonella spp. were isolated from 2520 eggs (one day's lay). In the second flock, where 24/150 hens were infected with S. enteritidis PT13, extraintestinal infection was found in nine hens and involved the ovaries and/or oviduct in two hens. Salmonella enteritidis PT13 was isolated from one sample of egg contents and from one sample of cracked shells from among 14,040 eggs (one day's lay) from this flock. The overall prevalence of S. enteritidis-contaminated eggs from the two flocks with infected hens was less than 0.06%. Other Salmonella spp. isolated were S. heidelberg from 58 hens (10%), and S. hadar, S. mbandaka and S. typhimurium from one hen (0.2%) each. The MAT with antigens of S. pullorum had a sensitivity of 81% and a specificity of 24% for detecting S. enteritidis-infected hens.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1423059
Xie, Yicheng; Savell, Jeffrey W; Arnold, Ashley N; Gehring, Kerri B; Gill, Jason J; Taylor, T Matthew
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.
Having documented information available on the capability of Salmonella to remain in the cladode tissue it is important to understand the role of nopal on the lifecycle of enteropathogenic bacteria in humans, as well as for management and control programs of theses pathogens in plants. Because of th...
Fresh produce associated outbreaks have increased in the last few years. E.coli O157:H7 and Salmonella have been causative agents of infection in these outbreaks. Fresh produce is consumed raw, and in the absence of terminal kill treatment, it is imperative to understand sources of contamination o...
Forsyth, J R; Bennett, N McK; Hogben, S; Hutchinson, E M; Rouch, G; Tan, A; Taplin, J
In 1977 two major outbreaks of salmonella infection originated in Victoria. The first of these, involving Salmonella Bredeney, continued over some seven months and was traced to contamination of powdered milk-based infant formulae during manufacture. This caused cases of gastroenteritis among young children throughout Australia. Another incident led to the discovery that salmonella serovars were colonising not one, but a number of dairy factories through the State. The second outbreak was of typhoid, stemming from a carrier working in a sandwich bar, and occurred during the course of the first, almost overwhelming public health resources and delaying investigation of the first outbreak. The background, recognition, course, investigation and resolution of these, previously unpublished, outbreaks are described, drawing upon the experiences of authors involved at the clinical, public health and laboratory levels, and preserved, contemporary records. Taken together, these outbreaks directly stimulated radical improvements in the construction and management of dairy factories in the State; initiated the adoption of risk management concepts in food factories; caused the launch of regional regulations compelling notification of salmonellas found in food manufacture; and led to the setting-up of an enhanced national, laboratory-based system for the collection, analysis and dissemination of information on enteric pathogens.
Tonziello, Gilda; Valentinotti, Romina; Arbore, Enrico; Cassetti, Paolo; Luzzati, Roberto
Patient: Male, 73 Final Diagnosis: Salmonella typhimurium abscess of the chest wall Symptoms: — Medication: Ciprofloxacin Clinical Procedure:— Specialty: Infectious Diseases Objective: Unusual clinical course Background: Non-typhoid Salmonella extra-intestinal infections usually develop in infants and in adult patients with pre-existing predisposing conditions. Blood stream infections and urinary tract infections are the most common clinical presentations, but other sites of infection may be involved as well. Case Report: We describe a case of invasive salmonellosis caused by Salmonella typhimurium involving the chest wall in a 73-year-old man. The patient had suffered from gastroenteritis followed by left basal pneumonia with pleural effusion 7 weeks before. The CT scan of the chest wall showed a pericostal abscess with shirt-stud morphology near the left last cartilaginous arch. The abscess was surgically drained and patient was cured after a 40-day ciprofloxacin treatment. Conclusions: A review of the literature on extra-intestinal non-typhoid salmonellosis shows that pleuropulmonary and soft-tissue infections are uncommon. We argue that non-typhoid Salmonella might be considered as a possible cause of chest wall abscess in individuals with recent history of gastroenteritis complicated by pneumonia and pleural effusion. PMID:24298305
... Drug Administration 21 CFR Part 118 Prevention of Salmonella Enteritidis in Shell Eggs During... part 118 to correct the following information: (1) The date by which egg producers must register their... address to which egg producers must send their CD-ROM. Publication of this document constitutes...
This pilot analysis was conducted with data from 52 conventional grow-out broiler flocks in a prospective field observational study in the Southeastern U.S. from 2003-2006. Each flock was sampled for Salmonella one week before the end of grow-out, upon arrival at the processing plant, and during pr...
There is a strong association between the incidence of human illness and the prevalence of Salmonella Enteritidis in commercial egg-producing poultry. Although most egg-associated disease around the world has been attributed to S. Enteritidis, other serovars are sometimes implicated. The deposition ...
Wielding, Sally; Scott, Gordon
We report a case of isolated urinary Salmonella enterica serotype Typhi in an HIV-positive man who has sex with men. He was clinically well and blood and stool cultures were negative, indicating that this may have been a sexually acquired urinary tract infection.
Schrauder, Annette; Alpers, Katharina; Werber, Dirk; Frank, Christina; Prager, Rita; Rabsch, Wolfgang; Broll, Susanne; Feil, Fabian; Roggentin, Peter; Bockemühl, Jochen; Tschäpe, Helmut; Ammon, Andrea; Stark, Klaus
A nationwide outbreak of Salmonella Agona caused by aniseed-containing herbal tea occurred from October 2002 through July 2003 among infants in Germany. Consumers should adhere strictly to brewing instructions, although in exceptional cases this precaution may not be protective, particularly when preparing tea for vulnerable age groups. PMID:16022796
Huang, Xi; Huang, Qiong; Dun, Zhongjun; Huang, Wei; Wu, Shuyu; Liang, Junhua; Deng, Xiaoling; Zhang, Yonghui
We used active and passive surveillance to estimate nontyphoidal Salmonella (NTS) infection during 2012 in Guangdong Province, China. Under passive surveillance, for every reported NTS infection, an estimated 414.8 cases occurred annually. Under active surveillance, an estimated 35.8 cases occurred. Active surveillance provides remarkable advantages in incidence estimate.
One of the primary limitations of cancer gene therapy is lack of selectivity of the therapeutic gene to tumor cells. Current efforts are focused on discovering and developing tumor-targeting vectors that selectively target only cancer cells but spare normal cells to improve the therapeutic index. The use of preferentially tumor-targeting bacteria as vectors is one of the innovative approaches for the treatment of cancer. This is based on the observation that some obligate or facultative-anaerobic bacteria are capable of multiplying selectively in tumors and inhibiting their growth. In this study, we exploited attenuated Salmonella as a tumoricidal agent and a vector to deliver genes for tumor-targeted gene therapy. Attenuated Salmonella, carrying a eukaryotic expression plasmid encoding an anti-angiogenic gene, was used to evaluate its' ability for tumor targeting and gene delivery in murine tumor models. We also investigated the use of a polymer to modify or shield Salmonella from the pre-existing immune response in the host in order to improve gene delivery to the tumor. These results suggest that tumor-targeted gene therapy using Salmonella carrying a therapeutic gene, which exerts tumoricidal and anti-angiogenic activities, represents a promising strategy for the treatment of tumors.
Helm, R Allen; Lee, Alison G; Christman, Harry D; Maloy, Stanley
Most Salmonella serovars are general pathogens that infect a variety of hosts. These "generalist" serovars cause disease in many animals from reptiles to mammals. In contrast, a few serovars cause disease only in a specific host. Host-specific serovars can cause a systemic, often fatal disease in one species yet remain avirulent in other species. Host-specific Salmonella frequently have large genomic rearrangements due to recombination at the ribosomal RNA (rrn) operons while the generalists consistently have a conserved chromosomal arrangement. To determine whether this is the result of an intrinsic difference in recombination frequency or a consequence of lifestyle difference between generalist and host-specific Salmonella, we determined the frequency of rearrangements in vitro. Using lacZ genes as portable regions of homology for inversion analysis, we found that both generalist and host-specific serovars of Salmonella have similar tolerances to chromosomal rearrangements in vitro. Using PCR and genetic selection, we found that generalist and host-specific serovars also undergo rearrangements at rrn operons at similar frequencies in vitro. These observations indicate that the observed difference in genomic stability between generalist and host-specific serovars is a consequence of their distinct lifestyles, not intrinsic differences in recombination frequencies.
Chen, Hung-Ming; Wang, Yue; Su, Lin-Hui; Chiu, Cheng-Hsun
Nontyphoid Salmonella is the most common bacterial pathogen causing gastrointestinal infection worldwide. Most nontyphoid Salmonella infection is limited to uncomplicated gastroenteritis that seldom requires antimicrobial treatment. Nevertheless, invasive infections, such as bacteremia, osteomyelitis, and meningitis, may occur and require antimicrobial therapy. Continuous genetic and genomic evolution in Salmonella leading to increased virulence and resistance to multiple drugs are of significant public health concern. Two major changes in the epidemiology of nontyphoid salmonellosis in Europe and in the USA occurred in the second half of the 20(th) century: the emergence of foodborne human infections caused by Salmonella enterica serotype Enteriditis and by multidrug-resistant strains of Salmonella enterica serotype Typhimurium. In the 21(st) century, a worsening situation is the increasing resistance to fluoroquinolones and third-generation cephalosporins in nontyphoid Salmonella. Clinical isolates showing carbapenem resistance also have been identified. Although antimicrobial therapy is usually not indicated for uncomplicated Salmonella gastroenteritis, recent studies indicated that a short-course ceftriaxone therapy (3-5 days) for patients with severe gastroenteritis would lead to a faster clinical recovery. Continuous surveillance of Salmonella in both humans and animals is mandatory. A better understanding of the mechanisms that lead to the emergence of antimicrobial resistance in Salmonella may help in the devising of better interventional strategies to reduce the spread of resistant Salmonella between humans and reservoirs along the food chain.
Bhargava, K.K.; O'Neil, J.B.; Prior, M.G.; Dunkelgod, K.E.
The incidence of Salmonella contamination in ten Saskatchewan broiler flocks varying in size from 6 200 to 14 000 was investigated from February, 1977 to April, 1979. Prior to the initial chick placement, brooding equipment, feed, water and fresh litter samples were found to be free of Salmonellae. Samples obtained from the clean and disinfected processing plant equipment before the commencement of daily operation were negative except the isolation for Salmonella anatum from the fingers of the defeathering machine in flock 4. There was no evidence of Salmonella contamination in flocks 5, 6, 8 and 10. The incidence of Salmonella was lower when cloacal swabs were taken from day old chicks fasted for 48 hours than for the same groups of chicks when carcasses were blended in nutrient broth (flocks 7 and 9). The blending of such chicks appears to be a more critical test. The serotypes isolated from eviscerated birds were the same as those isolated from used litter samples. Salmonella saintpaul was isolated from a water sample at 53 days in flock 1 and the same serotype was recovered from the intestinal contents and skin of eviscerated birds. Salmonella typhimurium was recovered from the eviscerated birds and neck samples in flock 3. In flock 4, S. saintpaul and S. anatum were isolated from 13% of the eviscerated birds sampled. Salmonella thompson, Salmonella agona and Salmonella heidelberg were recovered from 61%, 5% and 1%, respectively, of the processed carcasses sampled in flock 7. PMID:6831304
Lin, Dachuan; Yan, Meiying; Lin, Song; Chen, Sheng
Hydrogen sulfide (H2S) production is considered a typical characteristic of Salmonella and an important marker for Salmonella isolation. In this study, a total of 82 (26%) Salmonella strains were isolated from 113 chicken and 204 pork samples, within which 49 Salmonella strains were H2S positive and 33 were H2S negative. Salmonella enterica serovar Derby was most prevalent in both pork and chicken followed by S. Typhimurium in pork and S. Heidelberg in chicken. Salmonella isolated from pork exhibited a much higher H2S positive rate than those from chicken (68% versus 31%). The most prevalent H2S negative serotypes were S. Derby (40%) and S. Heidelberg (30%) in chicken, and S. Typhimurium (23%) and S. Enteritidis (23%) in pork. spvC, a plasmid-encoded virulence marker, was detected in 51% and 42% of the H2S positive and negative Salmonella respectively. The presence of the two most important serotypes, S. Enteritidis and S. Typhimurium, as well as a virulence plasmid in H2S negative Salmonella suggested that H2S negative Salmonella is also a significant public health concern. Such finding warrants the development of an improved method for effective coverage of H2S negative Salmonella.
van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J
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.
Gurman, P M; Ross, T; Holds, G L; Jarrett, R G; Kiermeier, A
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,,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.
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...
Li, Ruichao; Wang, Yang; Shen, Jianzhong; Wu, Congming
Salmonella is one of the most important foodborne pathogens, which causes a huge economic burden worldwide. To detect Salmonella rapidly is very meaningful in preventing salmonellosis and decreasing economic losses. Currently, isolation of Salmonella is confirmed by biochemical and serobased serotyping methods, which are time consuming, labor intensive, and complicated. To solve this problem, a hexa-plex polymerase chain reaction (PCR) method was developed using comparative genomics analysis and multiplex PCR technology to detect Salmonella and Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Agona, Salmonella Choleraesuis, and Salmonella Pullorum simultaneously. The accuracy of this method was tested by a collection of 142 Salmonella. Furthermore, the strategy described in this article to mine serovar-specific fragments for Salmonella could be used to find specific fragments for other Salmonella serotypes and bacteria. The combination of this strategy and multiplex PCR is promising in the rapid identification of foodborne pathogens.
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...
... Answers Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production... Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation'' (the draft guidance... rule entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage,...
Poultry are sampled often for Salmonella during growout on the farm and throughout the processing plant. While on farm sampling is not currently a regulatory requirement it can be useful in determining Salmonella status of each flock. On farm sampling can include varying types of both environmental ...
EPIDEMIOLOGY, *TYPHOID, SENSITIVITY, MEDIA, PUBLIC HEALTH, CULTURES(BIOLOGY), SOUTH KOREA, SHIGELLA, ANTIBIOTICS , RESISTANCE (BIOLOGY), BLOOD ANALYSIS, FOOD HANDLERS, SALMONELLA PARATYPHI, SALMONELLA TYPHIMURIUM.
The cultural methods require 4 to 7 days for presumptive evidence of Salmonella in foodstuffs. Attempts in time shortening have resulted in combination of pre-enrichment or selective enrichment with time saving genetical or immunological tests. Proceedings of enzyme immunoassays for applications in Salmonella screening are important. Involving monoclonal antibodies, fluorescent or chemiluminescent substrates, there are some commercial Salmonella test kits. Especially rapid EIA methods, here advantages and disadvantages are discussed.
Phoon, Yee Wei; Chan, Yuen Yue Candice; Koh, Tze Hsien
Multidrug-resistant Salmonella is a well-recognised problem worldwide, especially in developing countries such as India, where non-typhoidal Salmonella infections and enteric fever are endemic. Antimicrobial resistance, particularly to fluoroquinolones, is common and leads to the frequent use of alternative agents, such as azithromycin. We herein describe the first reported case of azithromycin-resistant Salmonella gastroenteritis in a Singaporean patient. PMID:26311915
Mahajan, R K; Sharma, S; Madan, P; Sharma, N
Salmonella Typhi has rarely been associated with focal abscesses; and in literature, there is no evidence of its association with abscesses in the neck spaces. Ability of Salmonella Typhi to invade and localise in the neck spaces not only poses a diagnostic challenge but also underscores the necessity to understand the mechanisms that facilitate Salmonella Typhi to establish infections at sites completely non-traditional to the organism.
Kozlica, Jennifer; Claudet, Amanda L; Solomon, Deborah; Dunn, John R; Carpenter, L Rand
Salmonella I 4,,12:i:- is an emerging serotype, and little information regarding attribution or risk factors for infection has been documented. We investigated an outbreak of Salmonella I 4,,12:i:- infections in a rural community and identified the community's private water system as the source of infection. Five people were ill with gastroenteritis. Water testing identified Salmonella. Contamination of the unprotected spring from an environmental source was suspected.
Yao, Kuan; Muruvanda, Tim; Roberts, Richard J.; Payne, Justin; Allard, Marc W.
Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791). PMID:26988049
Yao, Kuan; Muruvanda, Tim; Roberts, Richard J; Payne, Justin; Allard, Marc W; Hoffmann, Maria
Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791).
Gaillot, Olivier; Di Camillo, Patrick; Berche, Patrick; Courcol, René; Savage, Colette
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
Grant, Ar'Quette; Hashem, Fawzy; Parveen, Salina
Salmonella and Campylobacter are major causes of foodborne related illness and are traditionally associated with consuming undercooked poultry and/or consuming products that have been cross contaminated with raw poultry. Many of the isolated Salmonella and Campylobacter that can cause disease have displayed antimicrobial resistance phenotypes. Although poultry producers have reduced on-the-farm overuse of antimicrobials, antimicrobial resistant Salmonella and Campylobacter strains still persist. One method of bio-control, that is producing promising results, is the use of lytic bacteriophages. This review will highlight the current emergence and persistence of antimicrobial resistant Salmonella and Campylobacter recovered from poultry as well as bacteriophage research interventions and limitations.
Bartlett, K H; Trust, T J; Lior, H
Salmonellae were isolated from 21% of the samples of freshwater aquarium frogs tested and from 25% of the samples of aquarium water containing these frogs. The salmonellae were Salmonella arizonae, S. bovis-morbificans, S. hadar, S. saint-paul, S. typhimurium, and S. worthington. These isolations were made over a period of 9 months and from three different cities. This association of salmonellae with frogs may contribute to cases of human salmonellosis since other aquarium species have already been shown to contribute to such cases. PMID:879765
Bahadoran, Mahdi; Noorden, Ahmad Fakhrurrazi Ahmad; Mohajer, Faeze Sadat; Abd Mubin, Mohamad Helmi; Chaudhary, Kashif; Jalil, Muhammad Arif; Ali, Jalil; Yupapin, Preecha
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.
Tezcan-Merdol, Dilek; Ljungström, Marianne; Winiecka-Krusnell, Jadwiga; Linder, Ewert; Engstrand, Lars; Rhen, Mikael
The ability of salmonellae to become internalized and to survive and replicate in amoebae was evaluated by using three separate serovars of Salmonella enterica and five different isolates of axenic Acanthamoeba spp. In gentamicin protection assays, Salmonella enterica serovar Dublin was internalized more efficiently than Salmonella enterica serovar Enteritidis or Salmonella enterica serovar Typhimurium in all of the amoeba isolates tested. The bacteria appeared to be most efficiently internalized by Acanthamoeba rhysodes. Variations in bacterial growth conditions affected internalization efficiency, but this effect was not altered by inactivation of hilA, a key regulator in the expression of the invasion-associated Salmonella pathogenicity island 1. Microscopy of infected A. rhysodes revealed that S. enterica resided within vacuoles. Prolonged incubation resulted in a loss of intracellular bacteria associated with morphological changes and loss of amoebae. In part, these alterations were associated with hilA and the Salmonella virulence plasmid. The data show that Acanthamoeba spp. can differentiate between different serovars of salmonellae and that internalization is associated with cytotoxic effects mediated by defined Salmonella virulence loci. PMID:15184177
Hsieh, Yi-Cheng; Poole, Toni L; Runyon, Mick; Hume, Michael; Herrman, Timothy J
The objective of this study was to characterize 365 nontyphoidal Salmonella enterica isolates from animal feed. Among the 365 isolates, 78 serovars were identified. Twenty-four isolates (7.0%) were recovered from three of six medicated feed types. Three of these isolates derived from the medicated feed, Salmonella Newport, Salmonella Typhimurium var. O 5- (Copenhagen), and Salmonella Lexington var. 15+ (Manila), displayed antimicrobial resistance. Susceptibility testing revealed that only 3.0% (12) of the 365 isolates displayed resistance to any of the antimicrobial agents. These 12 isolates were recovered from unmedicated dry beef feed (n = 3), medicated dry beef feed (n = 3), cabbage culls (n = 2), animal protein products (n = 2), dry dairy cattle feed (n = 1), and fish meal (n = 1). Only Salmonella Newport and Salmonella Typhimurium var. O 5- (Copenhagen) were multidrug resistant. Both isolates possessed the IncA/C replicon and the blaCMY-2 gene associated with cephalosporin resistance. Plasmid replicons were amplified from 4 of 12 resistant isolates. Plasmids (40 kb) were Salmonella Montevideo and Salmonella Kentucky. Conjugation experiments were done using 7 of the 12 resistant isolates as donors. Only Salmonella Montevideo, possessing a plasmid and amplifying IncN, produced transconjugants. Transconjugants displayed the same antimicrobial resistance profile as did the donor isolate. Three isolates that amplified replicons corresponding to IncA/C or IncHI2 did not produce transconjugants at 30 or 37°C. The results of this study suggest that the prevalence of antimicrobial-resistant Salmonella contaminating animal feed is low in Texas. However, Salmonella was more prevalent in feed by-products; fish meal had the highest prevalence (84%) followed by animal protein products (48%). Ten of the 35 feed types had no Salmonella contamination. Further investigation is needed to understand the possible role of specific feed types in the dissemination of antimicrobial
Zancan, Glaci T.; Bacila, Metry
Zancan, Glaci T. (Universidade do Paraná, Curitiba, Paraná, Brazil), and Metry Bacila. Fructose-6-phosphate reductase from Salmonella gallinarum. J. Bacteriol. 87:614–618. 1964.—A fructose-6-phosphate reductase present in cell-free extracts of Salmonella gallinarum was purified approximately 42 times. The optimal pH for this enzyme is 8.0. The enzyme is specific for fructose-6-phosphate and reduced nicotinamide adenine dinucleotide (NADH). The dissociation constants are 1.78 × 10−4m for fructose-6-phosphate and 8.3 × 10−5m for NADH. The Q10, reaction order, and equilibrium constant were determined. The enzyme is sensitive to p-chloromercuribenzoic acid, but not to o-iodosobenzoic acid nor to N-ethylmaleimide. PMID:14127579
Penha Filho, Rafael Antonio Casarin; de Paiva, Jacqueline Boldrin; da Silva, Mariana Dias; de Almeida, Adriana Maria; Berchieri, Angelo
The ideal live vaccine to control Salmonella in commercial chicken flocks should engender protection against various strains. The purpose of the present study was to confirm the attenuation of a Salmonella Gallinarum (SG) mutant strain with deletion on genes cobS and cbiA, that are involved in the biosynthesis of cobalamin. Furthermore, evaluate its use as a live vaccine against Salmonella. For the evaluation of the vaccine efficacy, two experiments were conducted separately. Birds from a commercial brown line of chickens were used to perform challenge with SG wild type strain and birds from a commercial white line of chickens were used to perform challenge with Salmonella Enteritidis (SE) wild type strain. In both experiments, the birds were separated in three groups (A, B and C). Birds were orally vaccinated with the SG mutant as the following programme: group A, one dose at 5 days of age; group B, one dose at 5 days of age and a second dose at 25 days of age; and group C, birds were kept unvaccinated as controls. At 45 days of age, birds from all groups, including the control, were challenged orally by SG wild type (brown line) or SE wild type (white line). Lastly, another experiment was performed to evaluate the use of the SG mutant strain to prevent caecal colonization by SE wild type on 1-day-old broiler chicks. Mortality and systemic infection by SG wild type strain were assessed in brown chickens; faecal shedding and systemic infection by SE wild type were assessed in white chickens and caecal colonization was assessed in broiler chicks. Either vaccination with one or two doses of SG mutant, were capable to protect brown chickens against SG wild type. In the experiment with white chickens, only vaccination with two doses of SG mutant protected the birds against challenge with SE wild type. Although, SG mutant could not prevent caecal colonization in 1-day-old broiler chicks by the challenge strain SE wild type. Overall, the results indicated that SG mutant
Guilloteau, L A; Wallis, T S; Gautier, A V; MacIntyre, S; Platt, D J; Lax, A J
The Salmonella dublin virulence plasmid mediates systemic infection in mice and cattle. Here, we analyze the interaction between wild-type and plasmid-cured Salmonella strains with phagocytes in vitro and in vivo. The intracellular recovery of S. dublin from murine peritoneal and bovine alveolar macrophages cultured in the presence of gentamicin in vitro was not related to virulence plasmid carriage. However, the virulence plasmid increased the lytic activity of S. dublin, Salmonella typhimurium, and Salmonella choleraesuis for resident or activated mouse peritoneal macrophages. Lysis was not mediated by spv genes and was abolished by cytochalasin D treatment. Peritoneal and splenic macrophages were isolated from mice 4 days after intraperitoneal infection with wild-type or plasmid-cured S. dublin strains. The wild-type strain was recovered in significantly higher numbers than the plasmid-cured strain. However, the intracellular killing rates of such cells cultured in vitro for both S. dublin strains were not significantly different. Four days after infection, there was a lower increase of phagocyte numbers in the peritoneal cavities and spleens of mice infected with the wild-type strain compared with the plasmid-cured strain. The virulence plasmid influenced the survival of macrophages in vitro following infection in vivo as assessed by microscopy. Cells from mice infected with the plasmid-cured strain survived better than those from mice infected with the wild-type strain. This is the first report demonstrating an effect of the virulence plasmid on the interaction of Salmonella strains with macrophages. Plasmid-mediated macrophage dysfunction could influence the recruitment and/or the activation of phagocytic cells and consequently the net growth of Salmonella strains during infection. PMID:8757880
Braukmann, Maria; Methner, Ulrich; Berndt, Angela
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.
Zheng, Jin Hai
Obligate or facultative anaerobic bacteria such as Bifidobacterium, Clostridium, Salmonella, or Escherichia coli specifically colonize and proliferate inside tumor tissues and inhibit tumor growth. Among them, attenuated Salmonella typhimurium (S. typhimurium) has been widely studied in animal cancer models and Phase I clinical trials in human patients. S. typhimurium genes are easily manipulated; thus diverse attenuated strains of S. typhimurium have been designed and engineered as tumor-targeting therapeutics or drug delivery vehicles that show both an excellent safety profile and therapeutic efficacy in mouse models. An attenuated strain of S. typhimurium, VNP20009, successfully targeted human metastatic melanoma and squamous cell carcinoma in Phase I clinical trials; however, the efficacy requires further refinement. Along with the characteristics of self-targeting, proliferation, and deep tissue penetration, the ease of genetic manipulation allows for the production of more attenuated strains with greater safety profiles and vector systems that deliver designable cargo molecules for cancer diagnosis and/or therapy. Here, we discuss recent progress in the field of Salmonellae-mediated cancer therapy. PMID:27689027
Zheng, Jin Hai; Min, Jung-Joon
Obligate or facultative anaerobic bacteria such as Bifidobacterium, Clostridium, Salmonella, or Escherichia coli specifically colonize and proliferate inside tumor tissues and inhibit tumor growth. Among them, attenuated Salmonella typhimurium (S. typhimurium) has been widely studied in animal cancer models and Phase I clinical trials in human patients. S. typhimurium genes are easily manipulated; thus diverse attenuated strains of S. typhimurium have been designed and engineered as tumor-targeting therapeutics or drug delivery vehicles that show both an excellent safety profile and therapeutic efficacy in mouse models. An attenuated strain of S. typhimurium, VNP20009, successfully targeted human metastatic melanoma and squamous cell carcinoma in Phase I clinical trials; however, the efficacy requires further refinement. Along with the characteristics of self-targeting, proliferation, and deep tissue penetration, the ease of genetic manipulation allows for the production of more attenuated strains with greater safety profiles and vector systems that deliver designable cargo molecules for cancer diagnosis and/or therapy. Here, we discuss recent progress in the field of Salmonellae-mediated cancer therapy.
McLaughlin, Patrick A; McClelland, Michael; Yang, Hee-Jeong; Porwollik, Steffen; Bogomolnaya, Lydia; Chen, Juei-Suei; Andrews-Polymenis, Helene; van der Velden, Adrianus W M
Salmonellae are pathogenic bacteria that cause significant morbidity and mortality in humans worldwide. Salmonellae establish infection and avoid clearance by the immune system by mechanisms that are not well understood. We previously showed that l-asparaginase II produced by Salmonella enterica serovar Typhimurium (S Typhimurium) inhibits T cell responses and mediates virulence. In addition, we previously showed that asparagine deprivation such as that mediated by l-asparaginase II of S Typhimurium causes suppression of activation-induced T cell metabolic reprogramming. Here, we report that STM3997, which encodes a homolog of disulfide bond protein A (dsbA) of Escherichia coli, is required for l-asparaginase II stability and function. Furthermore, we report that l-asparaginase II localizes primarily to the periplasm and acts together with l-asparaginase I to provide S Typhimurium the ability to catabolize asparagine and assimilate nitrogen. Importantly, we determined that, in a murine model of infection, S Typhimurium lacking both l-asparaginase I and II genes competes poorly with wild-type S Typhimurium for colonization of target tissues. Collectively, these results indicate that asparagine catabolism contributes to S Typhimurium virulence, providing new insights into the competition for nutrients at the host-pathogen interface.
Erhardt, Marc; Dersch, Petra
Enteric pathogens such as Salmonella and Yersinia evolved numerous strategies to survive and proliferate in different environmental reservoirs and mammalian hosts. Deciphering common and pathogen-specific principles for how these bacteria adjust and coordinate spatiotemporal expression of virulence determinants, stress adaptation, and metabolic functions is fundamental to understand microbial pathogenesis. In order to manage sudden environmental changes, attacks by the host immune systems and microbial competition, the pathogens employ a plethora of transcriptional and post-transcriptional control elements, including transcription factors, sensory and regulatory RNAs, RNAses, and proteases, to fine-tune and control complex gene regulatory networks. Many of the contributing global regulators and the molecular mechanisms of regulation are frequently conserved between Yersinia and Salmonella. However, the interplay, arrangement, and composition of the control elements vary between these closely related enteric pathogens, which generate phenotypic differences leading to distinct pathogenic properties. In this overview we present common and different regulatory networks used by Salmonella and Yersinia to coordinate the expression of crucial motility, cell adhesion and invasion determinants, immune defense strategies, and metabolic adaptation processes. We highlight evolutionary changes of the gene regulatory circuits that result in different properties of the regulatory elements and how this influences the overall outcome of the infection process. PMID:26441883
Melo, Airis Maria Araújo; Alexandre, Dalila L; Furtado, Roselayne F; Borges, Maria F; Figueiredo, Evânia Altina T; Biswas, Atanu; Cheng, Huai N; Alves, Carlúcio R
Pathogen detection is a critical point for the identification and the prevention of problems related to food safety. Failures at detecting contaminations in food may cause outbreaks with drastic consequences to public health. In spite of the real need for obtaining analytical results in the shortest time possible, conventional methods may take several days to produce a diagnosis. Salmonella spp. is the major cause of foodborne diseases worldwide and its absence is a requirement of the health authorities. Biosensors are bioelectronic devices, comprising bioreceptor molecules and transducer elements, able to detect analytes (chemical and/or biological species) rapidly and quantitatively. Electrochemical immunosensors use antibody molecules as bioreceptors and an electrochemical transducer. These devices have been widely used for pathogen detection at low cost. There are four main techniques for electrochemical immunosensors: amperometric, impedimetric, conductometric, and potentiometric. Almost all types of immunosensors are applicable to Salmonella detection. This article reviews the developments and the applications of electrochemical immunosensors for Salmonella detection, particularly the advantages of each specific technique. Immunosensors serve as exciting alternatives to conventional methods, allowing "real-time" and multiple analyses that are essential characteristics for pathogen detection and much desired in health and safety control in the food industry.
Park, Tu San; Li, Wenyue; McCracken, Katherine E; Yoon, Jeong-Yeol
Smartphone-based optical detection is a potentially easy-to-use, handheld, true point-of-care diagnostic tool for the early and rapid detection of pathogens. Paper microfluidics is a low-cost, field-deployable, and easy-to-use alternative to conventional microfluidic devices. Most paper-based microfluidic assays typically utilize dyes or enzyme-substrate binding, while bacterial detection on paper microfluidics is rare. We demonstrate a novel application of smartphone-based detection of Salmonella on paper microfluidics. Each paper microfluidic channel was pre-loaded with anti-Salmonella Typhimurium and anti-Escherichia coli conjugated submicroparticles. Dipping the paper microfluidic device into the Salmonella solutions led to the antibody-conjugated particles that were still confined within the paper fibers to immunoagglutinate. The extent of immunoagglutination was quantified by evaluating Mie scattering from the digital images taken at an optimized angle and distance with a smartphone. A smartphone application was designed and programmed to allow the user to position the smartphone at an optimized angle and distance from the paper microfluidic device, and a simple image processing algorithm was implemented to calculate and display the bacterial concentration on the smartphone. The detection limit was single-cell-level and the total assay time was less than one minute.
Pande, Vivek V.; Devon, Rebecca L.; Sharma, Pardeep; McWhorter, Andrea R.; Chousalkar, Kapil K.
Members of Salmonella enterica are frequently involved in egg and egg product related human food poisoning outbreaks worldwide. In Australia, Salmonella Typhimurium is frequently involved in egg and egg product related foodborne illness and Salmonella Mbandaka has also been found to be a contaminant of the layer farm environment. The ability possessed by Salmonella Enteritidis to colonize reproductive organs and contaminate developing eggs has been well-described. However, there are few studies investigating this ability for Salmonella Typhimurium. The hypothesis of this study was that the Salmonella Typhimurium can colonize the gut for a prolonged period of time and that horizontal infection through feces is the main route of egg contamination. At 14 weeks of age hens were orally infected with either S. Typhimurium PT 9 or S. Typhimurium PT 9 and Salmonella Mbandaka. Salmonella shedding in feces and eggs was monitored for 15 weeks post-infection. Egg shell surface and internal contents of eggs laid by infected hens were cultured independently for detection of Salmonella spp. The mean Salmonella load in feces ranged from 1.54 to 63.35 and 0.31 to 98.38 most probable number/g (MPN/g) in the S. Typhimurium and S. Typhimurium + S. Mbandaka group, respectively. No correlation was found between mean fecal Salmonella load and frequency of egg shell contamination. Egg shell contamination was higher in S. Typhimurium + S. Mbandaka infected group (7.2% S. Typhimurium, 14.1% S. Mbandaka) compared to birds infected with S. Typhimurium (5.66%) however, co-infection had no significant impact on egg contamination by S. Typhimurium. Throughout the study Salmonella was not recovered from internal contents of eggs laid by hens. Salmonella was isolated from different segments of oviduct of hens from both the groups, however pathology was not observed on microscopic examination. This study investigated Salmonella shedding for up to 15 weeks p.i which is a longer period of time
Pande, Vivek V; Devon, Rebecca L; Sharma, Pardeep; McWhorter, Andrea R; Chousalkar, Kapil K
Members of Salmonella enterica are frequently involved in egg and egg product related human food poisoning outbreaks worldwide. In Australia, Salmonella Typhimurium is frequently involved in egg and egg product related foodborne illness and Salmonella Mbandaka has also been found to be a contaminant of the layer farm environment. The ability possessed by Salmonella Enteritidis to colonize reproductive organs and contaminate developing eggs has been well-described. However, there are few studies investigating this ability for Salmonella Typhimurium. The hypothesis of this study was that the Salmonella Typhimurium can colonize the gut for a prolonged period of time and that horizontal infection through feces is the main route of egg contamination. At 14 weeks of age hens were orally infected with either S. Typhimurium PT 9 or S. Typhimurium PT 9 and Salmonella Mbandaka. Salmonella shedding in feces and eggs was monitored for 15 weeks post-infection. Egg shell surface and internal contents of eggs laid by infected hens were cultured independently for detection of Salmonella spp. The mean Salmonella load in feces ranged from 1.54 to 63.35 and 0.31 to 98.38 most probable number/g (MPN/g) in the S. Typhimurium and S. Typhimurium + S. Mbandaka group, respectively. No correlation was found between mean fecal Salmonella load and frequency of egg shell contamination. Egg shell contamination was higher in S. Typhimurium + S. Mbandaka infected group (7.2% S. Typhimurium, 14.1% S. Mbandaka) compared to birds infected with S. Typhimurium (5.66%) however, co-infection had no significant impact on egg contamination by S. Typhimurium. Throughout the study Salmonella was not recovered from internal contents of eggs laid by hens. Salmonella was isolated from different segments of oviduct of hens from both the groups, however pathology was not observed on microscopic examination. This study investigated Salmonella shedding for up to 15 weeks p.i which is a longer period of time
Lathrop, Amanda A; Taylor, Tiffany; Schnepf, James
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.
Iaffaldano, N; Reale, A; Sorrentino, E; Coppola, R; Di Iorio, M; Rosato, M P
To investigate the possibility to carry pathogen bacteria in turkey flocks via cryopreserved semen, research was carried out 1) to investigate the microbial contamination of fresh and frozen thawed turkey semen and 2) to evaluate the effect of the freezing-thawing process on the survival of 3 serovars of Salmonella spp. experimentally inoculated in turkey semen. Five pools of semen diluted 4-fold were cooled, added with 8% of dimethylacetamide as a cryoprotectant, and aliquots of 80 muL were directly plunged into liquid nitrogen to form frozen pellets. Mesophilic viable counts, total and fecal coliforms, Enterobacteriaceae, enterococci, Campylobacter spp., and Salmonella spp. were investigated on fresh and thawed samples. Further, 5 pools of diluted semen were each divided into 3 subsamples, inoculated with 7.8 +/- 0.2 log cfu.mL(-1) of Salmonella Liverpool, Salmonella Montevideo, and Salmonella Braenderup, respectively, and cryopreserved before to assess the postthaw viability of Salmonella spp. strains. Fresh semen was highly contaminated by all of the saprophytic bacteria investigated and the cryopreservation process reduced the amount of mesophilic viable count and total coliforms (P < 0.05) and fecal coliforms, Enterobacteriaceae, and enterococci (P < 0.01) by about 1 log cfu.mL(-1). Conversely, neither Campylobacter spp. nor Salmonella spp. were found as endogenous bacteria in semen. In the inoculated semen, both Salmonella Liverpool, Salmonella Montevideo, and Salmonella Braenderup colonies were recovered postthaw, showing a significant reduction of 2.03 +/- 0.28, 3.08 +/- 0.22, and 2.72 +/- 0.23 log cfu.mL(-1), respectively, compared with the fresh semen (P < 0.001). In conclusion, the cryopreservation process allowed us to obtain a low reduction of microbial count both in endogenous saprophytic bacteria and artificially inoculated Salmonella spp. strains; therefore, the possibility of Samonella spp. transmission to flocks through the use of infected
Ma, Li; Zhang, Guodong; Gerner-Smidt, Peter; Tauxe, Robert V; Doyle, Michael P
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.
Zhang, Guodong; Ma, Li; Patel, Nehal; Swaminathan, Bala; Wedel, Stephanie; Doyle, Michael P
During May and June of 2005, 26 persons in several states were infected by a single strain (isolates indistinguishable by pulsed-field gel electrophoresis) of Salmonella enterica serotype Typhimurium after eating cake batter ice cream. The cake mix used to prepare the cake batter in the ice cream was implicated by epidemiologic investigation as the source of Salmonella contamination. Initial tests did not detect Salmonella in cake mix collected during the outbreak investigation. The objective of this study was to evaluate different procedures to isolate Salmonella from the implicated cake mix, cake, and ice cream. All outbreak-associated food samples (14 samples) were collected during the outbreak investigation by health departments of several of the states involved. Different combinations of Salmonella isolation procedures, including sample size, preenrichment broth, enrichment broth, enrichment temperature, and isolation medium, were used. Salmonella Typhimurium was isolated from two cake mix samples; the food isolates were indistinguishable from the outbreak pattern by pulsed-field gel electrophoresis subtyping. Universal preenrichment broth was substantially better than was lactose broth for preenrichment, and tetrathionate broth was better than was Rappaport-Vassiliadis broth for isolating Salmonella from the two positive cake mix samples. Although more typical Salmonella colonies were observed on plates from enrichment cultures grown at 35 degrees C, more confirmed Salmonella isolates were obtained from plates of enrichment cultures grown at 42 degrees C. Brilliant green agar, xylose lysine tergitol 4 agar, xylose lysine desoxycholate agar, Hektoen enteric agar, and bismuth sulfite agar plates were equally effective in isolating Salmonella from cake mix. The best combination of preenrichment-enrichment conditions for isolating the outbreak strain of Salmonella was preenrichment of cake mix samples in universal preenrichment broth at 35 degrees C for 24 h
Roumani, B M; Abdelnoor, A M; Hilan, C
Salmonella agona was isolated from an imported fish meal specimen and a Salmonella strain not listed in the Kauffmann-White Scheme was isolated from a shrimp specimen obtained from the Mediterranean coast of Lebanon. The biochemical and serological properties of the S. agona fish meal strain was identical to a standard strain. The serotype of the shrimp strain was O13,22 Vi. With the exception of hydrogen sulfide production the biochemical properties of the shrimp strain were similar to S. agona.
Verbrugghe, Elin; Vandenbroucke, Virginie; Dhaenens, Maarten; Shearer, Neil; Goossens, Joline; De Saeger, Sarah; Eeckhout, Mia; D'Herde, Katharina; Thompson, Arthur; Deforce, Dieter; Boyen, Filip; Leyman, Bregje; Van Parys, Alexander; De Backer, Patrick; Haesebrouck, Freddy; Croubels, Siska; Pasmans, Frank
The mycotoxin T-2 toxin and Salmonella Typhimurium infections pose a significant threat to human and animal health. Interactions between both agents may result in a different outcome of the infection. Therefore, the aim of the presented study was to investigate the effects of low and relevant concentrations of T-2 toxin on the course of a Salmonella Typhimurium infection in pigs. We showed that the presence of 15 and 83 μg T-2 toxin per kg feed significantly decreased the amount of Salmonella Typhimurium bacteria present in the cecum contents, and a tendency to a reduced colonization of the jejunum, ileum, cecum, colon and colon contents was noticed. In vitro, proteomic analysis of porcine enterocytes revealed that a very low concentration of T-2 toxin (5 ng/mL) affects the protein expression of mitochondrial, endoplasmatic reticulum and cytoskeleton associated proteins, proteins involved in protein synthesis and folding, RNA synthesis, mitogen-activated protein kinase signaling and regulatory processes. Similarly low concentrations (1-100 ng/mL) promoted the susceptibility of porcine macrophages and intestinal epithelial cells to Salmonella Typhimurium invasion, in a SPI-1 independent manner. Furthermore, T-2 toxin (1-5 ng/mL) promoted the translocation of Salmonella Typhimurium over an intestinal porcine epithelial cell monolayer. Although these findings may seem in favour of Salmonella Typhimurium, microarray analysis showed that T-2 toxin (5 ng/mL) causes an intoxication of Salmonella Typhimurium, represented by a reduced motility and a downregulation of metabolic and Salmonella Pathogenicity Island 1 genes. This study demonstrates marked interactions of T-2 toxin with Salmonella Typhimurium pathogenesis, resulting in bacterial intoxication.
Gong, Jiansen; Zhuang, Linlin; Zhu, Chunhong; Shi, Shourong; Zhang, Di; Zhang, Linji; Yu, Yan; Dou, Xinhong; Xu, Bu; Wang, Chengming
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.
Sabike, Islam I; Fujikawa, Hiroshi; Edris, Abobakr M
The growth kinetics of Salmonella Enteritidis in raw beef has been little studied so far. Thus, this study aimed to clarify the growth kinetics of the pathogen in ground beef using a growth model. When Salmonella cells inoculated at various initial doses into ground beef were incubated at a given temperature (24℃), the maximum population (Nmax) of the microbe at the stationary phase varied with the doses. This relationship was expressed with a polynomialequation for Nmax using the initial dose. The combination of the growth model and the polynomial equation successfully predicted Salmonella growth at a given initial dose. When Salmonella cells inoculated in ground beef were incubated at various constant temperatures, the growth curves of the pathogen and natural microflora (NM) were well described with the growth model. The rate constant of growth and the Nmax values for Salmonella and NM were then analyzed kinetically. From these results, growth curves of Salmonella and NM in ground beef stored at dynamic temperatures were successfully predicted. Competition between Salmonella and NM in ground beef was also found during the storage. This study could give usable information on the growth of Salmonella and NM in ground beef at various temperatures.
This study analyzed 106 Salmonella isolates from different points in broiler vertical integrations of two important poultry areas of Colombia. It was possible to identify the presence of Salmonella in five categories: breeder farm (17.9%), hatchery (6.6 %), broiler farm (38.7 %), processing plant (9...
Market pigs infected with Salmonella pose a significant food safety risk by carrying the pathogen into abattoirs. A study was conducted to determine the dynamic of Salmonella infection in market-weight pigs (220-240 lbs.). Pigs (n=24) were individually inoculated (intranasally; 108 cfu/mL) with Salm...
Salmonella infection causes a self-limiting gastroenteritis in humans but can also result in a life threatening invasive disease especially in old, young and/or immunocompromised patients. The prevalence of antimicrobial and multidrug-resistant Salmonella has increased worldwide since the 1980’s. Ho...
The efficacy of carvacrol (CAR), trans-cinnamaldehyde (TC), eugenol (EUG) and ß-resorcylic acid (BR) as a wash treatment for reducing Salmonella spp. on tomatoes was investigated. Plum tomatoes inoculated with a six-serotype mixture of Salmonella (108 CFU) were subjected to washing in sterile deion...
Jorge, Jannaina F.; Costa, Andressa B. V.; Rodrigues, Jorge L. N.; Girão, Evelyne S.; Luiz, Roberta S. S.; Sousa, Anastácio Q.; Moore, Sean R.; Menezes, Dalgimar B.; Leitão, Terezinha M. J. S.
Pyogenic liver abscesses caused by Salmonella enterica serotype Typhi, although rare, can occur especially in patients with pre-existing hepatobiliary disease, hepatocellular carcinoma, and metastatic liver tumors. We present a case of Salmonella liver abscesses complicating metastatic melanoma in a 24-year-old alcoholic male. PMID:24591434
Many laboratories that routinely sample broiler carcasses for Salmonella are primarily interested only in determining the presence or absence of Salmonella, so only one colony-forming unit may be selected. The objective of this study was to select several colonies from each of four selective plates...
Dairy farms are known reservoirs for Salmonella spp. and control of this organism is challenging. Salmonellae have been shown to be endemic in herds in part because they are easily spread between animals and throughout the farm environment. The impact of the infection on the herd is variable and dep...
... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Salmonella Enteritidis (SE) prevention measures. 118.4 Section 118.4 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....4 Salmonella Enteritidis (SE) prevention measures. You must follow the SE prevention measures...
... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Salmonella Enteritidis (SE) prevention measures. 118.4 Section 118.4 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....4 Salmonella Enteritidis (SE) prevention measures. You must follow the SE prevention measures...
... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Salmonella Enteritidis (SE) prevention measures. 118.4 Section 118.4 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....4 Salmonella Enteritidis (SE) prevention measures. You must follow the SE prevention measures...
Swine are often asymptomatic carriers of Salmonella spp., a leading cause of human bacterial foodborne disease. Vaccination against Salmonella is effective for protection of animal health and enhancement of food safety. However, current vaccines for swine may only offer limited cross-protection agai...
The logistics required for a National Egg Salmonella sampling Testing (NESST) project are described. Market egg sampling data has never been collected in the United States on a national basis and no regional sampling data has been collected in 10 years. Salmonella outbreaks continue to be attribute...
Salmonella is a major cause of foodborne illness in humans and causes over a third of all cases of gastroenteritis in the United States. Human foodborne outbreaks due to Salmonella have been traced to milk, beef, pork, and poultry. Fecal contamination of the carcass and hide is thought to be a maj...
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...
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. Although Salmonella prevalence has been examined among lymph nodes within an animal,...
Salmonella enterica is a zoonotic pathogen which can readily pass from animal to man through the consumption of contaminated food. The prevalence of Salmonella enterica associated with poultry and poultry meat products has been well documented and this prevalence has both public health and economic...
The peripheral lymph nodes (PLN) in cattle may contain Salmonella and thus are a potential source of contamination for ground beef. Research on the prevalence of Salmonella in these lymph nodes suggests that regional and seasonal differences occur with the seasonal fluctuations, a reflection of fly...
Introduction: Salmonella can invade and survive within host immune cells. Once internalized, these pathogens have the potential to disseminate throughout the lymphatic system and reside within lymph nodes. If so, because some lymph nodes are located within muscle and fat tissues, Salmonella-positiv...
Lopez-Medina, Marcela; Perez-Lopez, Araceli; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney
Salmonella persists for a long time in B cells; however, the mechanism(s) through which infected B cells avoid effector CD8 T cell responses has not been characterized. In this study, we show that Salmonella infects and survives within all B1 and B2 cell subpopulations. B cells are infected with a Salmonella typhimurium strain expressing an ovalbumin (OVA) peptide (SIINFEKL) to evaluate whether B cells process and present Salmonella antigens in the context of MHC-I molecules. Our data showed that OVA peptides are presented by MHC class I K(b)-restricted molecules and the presented antigen is generated through proteasomal degradation and vacuolar processing. In addition, Salmonella-infected B cells express co-stimulatory molecules such as CD40, CD80, and CD86 as well as inhibitory molecules such as PD-L1. Thus, the cross-presentation of Salmonella antigens and the expression of activation molecules suggest that infected B cells are able to prime and activate specific CD8(+) T cells. However, the Salmonella infection-stimulated expression of PD-L1 suggests that the PD-1/PD-L1 pathway may be involved in turning off the cytotoxic effector response during Salmonella persistent infection, thereby allowing B cells to become a reservoir for the bacteria.
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.
Martiny, Delphine; Dediste, Anne; Anglade, Claire; Vlaes, Linda; Moens, Catherine; Mohamed, Souad; Vandenberg, Olivier
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.
... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Salmonella Enteritidis (SE) prevention measures. 118.4 Section 118.4 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....4 Salmonella Enteritidis (SE) prevention measures. You must follow the SE prevention measures...
... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Salmonella Enteritidis (SE) prevention measures. 118.4 Section 118.4 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....4 Salmonella Enteritidis (SE) prevention measures. You must follow the SE prevention measures...
Switt, Andrea I Moreno; den Bakker, Henk C; Vongkamjan, Kitiya; Hoelzer, Karin; Warnick, Lorin D; Cummings, Kevin J; Wiedmann, Martin
Salmonella is an animal and human pathogen of worldwide concern. Surveillance programs indicate that the incidence of Salmonella serovars fluctuates over time. While bacteriophages are likely to play a role in driving microbial diversity, our understanding of the ecology and diversity of Salmonella phages is limited. Here we report the isolation of Salmonella phages from manure samples from 13 dairy farms with a history of Salmonella presence. Salmonella phages were isolated from 10 of the 13 farms; overall 108 phage isolates were obtained on serovar Newport, Typhimurium, Dublin, Kentucky, Anatum, Mbandaka, and Cerro hosts. Host range characterization found that 51% of phage isolates had a narrow host range, while 49% showed a broad host range. The phage isolates represented 65 lysis profiles; genome size profiling of 94 phage isolates allowed for classification of phage isolates into 11 groups with subsequent restriction fragment length polymorphism analysis showing considerable variation within a given group. Our data not only show an abundance of diverse Salmonella phage isolates in dairy farms, but also show that phage isolates that lyse the most common serovars causing salmonellosis in cattle are frequently obtained, suggesting that phages may play an important role in the ecology of Salmonella on dairy farms.
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...
Background: Salmonella spp. are responsible for 76 million illnesses per year in the U.S. Quaternary ammonium compounds (QAC) are commonly used antimicrobial agents. Reduced susceptibility to these compounds by a broad spectrum of organisms is a concern. Methods: Salmonella enterica strains with r...
Wang, Yin; Liu, Chongyang; Zhang, Zengfeng; Hu, Yuanyuan; Cao, Chenyang; Wang, Xin; Xi, Meili; Xia, Xiaodong; Yang, Baowei; Meng, Jianghong
Hypermutable pathogens can easily acquire mutation opportunities, as well as antimicrobial resistance, and are tremendous hazards to food safety and public health. In this study, a total of 96 (7.6%) hypermutators were identified from 1,264 Salmonella isolates recovered from retail foods. Pulsed-field gel electrophoresis analysis indicated that hypermutators were genetically diverse. Amino acid substitution of Val421Phe was detected in MutS in one hypermutator and Val246Ala in 56 other hypermutators, while no mutation in MutS was found among the remaining 39 hypermutators. Hypermutators in Salmonella isolates recovered in 2010 (9.3%) and 2008 (7.7%) were significantly more prevalent than those in 2007 (1.4%). The rate of hypermutators in mutton (22.2%) was significantly higher than that in chicken (7.9%) and pork (4.7%). In Salmonella Leimo isolates (60.0%), hypermutators were most frequently detected, followed by Salmonella Essen (50.0%), Salmonella Indiana (36.6%), Salmonella Kallo (25.0%), Salmonella Heidelberg (23.8%), Salmonella Typhimurium (14.0%), Salmonella Shubra (13.0%), Salmonella Albany (11.1%), Salmonella Agona (7.0%), Salmonella Gueuletapee (6.3%), and Salmonella Enteritidis (1.7%). Salmonella hypermutators in isolates recovered from retail food stored at ambient temperature (15.7%) were significantly more prevalent than those stored in chilled (3.1%) and frozen (5.4%) condition. The overall distributions of mutation frequencies of the 96 hypermutators (selected by rifampin) were from 2.16 × 10(-5) to 4.25 × 10(-1). Mutation frequencies of hypermutators of Salmonella Leimo, Salmonella Essen, Salmonella Kallo, and Salmonella Agona were relative low, while those of Salmonella Typhimurium, Salmonella Indiana, and Salmonella Shubra were extremely high. No significant correlation was found between mutation frequency and antimicrobial resistance of the hypermutators.
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 ...
Singer, Randall S; Mayer, Anne E; Hanson, Timothy E; Isaacson, Richard E
Cultivation methods are commonly used in Salmonella surveillance systems and outbreak investigations, and consequently, conclusions about Salmonella evolution and transmission are highly dependent on the performance characteristics of these methods. Past studies have shown that Salmonella serotypes can exhibit different growth characteristics in the same enrichment and selective media. This could lead not only to biased conclusions about the dominant strain present in a sample with mixed Salmonella populations, but also to a low sensitivity for detecting a Salmonella strain in a sample with only a single strain present. The objective of this study was to determine whether cultivation media select preferentially for specific strains of Salmonella in heterogeneous cultures. In this study, four different Salmonella strains (one Salmonella Newport, two Salmonella Typhimurium, and one Salmonella Enteritidis) were competed in a broth-based experiment and a bovine fecal experiment with varied combinations and concentrations of each strain. In all experiments, the strain of Salmonella Newport was the most competitive, regardless of the starting concentration and cultivation protocol. One strain of Salmonella Typhimurium was rarely detected in competition, even when it was the only strain present in bovine feces. Overall, the probability of detecting a specific Salmonella strain had little to do with its starting concentration in the sample. The bias introduced by culture could be dramatically biasing Salmonella surveillance systems and hindering traceback investigations during Salmonella outbreaks. Future studies should focus on the microbiological explanations for this Salmonella interstrain variability, approaches for minimizing the bias, and estimations of the public health significance of this bias.
... 40 Protection of Environment 32 2011-07-01 2011-07-01 false The salmonella typhimurium reverse....5265 The salmonella typhimurium reverse mutation assay. (a) Purpose. The Salmonella typhimurium.... (1) A reverse mutation assay in Salmonella typhimurium detects mutation in a gene of a...
Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck
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.
Back, Du-San; Shin, Gee-Wook; Wendt, Mitchell; Heo, Gang-Joon
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.
Miarelli, Maria; Drumo, Rosanna; Signorelli, Federica; Marchitelli, Cinzia; Pavone, Silvia; Pesciaroli, Michele; Ruggieri, Jessica; Chirullo, Barbara; Ammendola, Serena; Battistoni, Andrea; Alborali, Giovanni L; Manuali, Elisabetta; Pasquali, Paolo
Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important cause of acute food- borne zoonoses worldwide, typically carried by pigs. It is well known that Salmonella has evolved a wide array of strategies enabling it to invade the host, but little information is available on the specific host responses to Salmonella infections. In the present study, we used an in vivo approach (involving piglets infected with a virulent or an attenuated S. Typhimurium strain) coupled to histological and proteomic analysis of the cecum mucosa, to highlight the host pathways activated during S. Typhimurium infection. We confirm the complex host-pathogen interaction. Our data showed that the metabolic and the cytoskeleton organization functions were the most significantly altered. In particular, the modifications of energy metabolic pathway could suggest a "nutriprive" mechanism, in which the host reduce its metabolic and energetic status to limit Salmonella infection. This study could represent a preliminary approach, providing information useful to better understand the host-Salmonella interaction.
Back, Du-San; Shin, Gee-Wook; Wendt, Mitchell
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
Kuroki, Toshiro; Ishihara, Tomoe; Furukawa, Ichiro; Okatani, Alexandre Tomomitsu; Kato, Yukio
A total of 87 wild snakes of 6 species in 2 families collected in Japan were examined for the presence of Salmonella. The prevalence of Salmonella was 58.6%, and that of Salmonella enterica subspecies I, which includes most human pathogenic serotypes, accounted for 12.6%. S. enterica subspecies I was isolated from Japanese grass snakes and Japanese four-striped snakes, and the isolates belonged to 6 serotypes: S. enterica subspecies enterica serotypes Eastbourne, Mikawashima, Narashino, Newport, Saintpaul, and Thompson. The prevalence of S. enterica subspecies IIIb was higher (41.4%) than that of S. enterica subspecies I, and it was isolated from 4 snake species. The prevalence of Salmonella enterica subspecies and isolation of serotypes that are commonly detected in reptiles and human salmonellosis suggest that wild snakes may become a source of Salmonella infection.
Wick, Mary Jo
Infections with Salmonella enterica serovars remain a serious problem worldwide. While serovar Typhi causes significant morbidity and mortality that is restricted to humans, serovar Typhimurium causes gastroenteritidis in humans and can also infect other animals. As mice with the susceptible Nramp1 locus get systemic infection with serovar Typhimurium, murine infection models using this serovar have been widely used to decipher the immune mechanisms required to survive systemic Salmonella infection. This review summarizes recent studies in murine infection models that have advanced our understanding of the events that occur during the first days after oral Salmonella infection. The pathways of bacterial penetration across the intestinal epithelium, bacterial spread to draining (mesenteric) lymph nodes and dissemination to systemic tissues is discussed. The response of myeloid cell populations, including dendritic cells, inflammatory monocytes and neutrophils, during the early stage of infection is also discussed. Finally, the mechanisms driving recruitment of myeloid cells to infected intestinal lymphoid tissues and what is known about Toll-like receptor signaling pathways in innate immunity to Salmonella infection is also discussed.
: 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...
Brenneman, Karen E; McDonald, Caitlin; Kelly-Aehle, Sandra M; Roland, Kenneth L; Curtiss, Roy
Identification of individuals shedding Salmonella enterica serovar Typhi in stool is imperative during clinical trial safety evaluations. Recovery of live attenuated S. Typhi vaccine strains can be difficult because the mutations necessary for safety in humans often compromise survival in stringent selective enrichment media. RapidChek® SELECT™ Salmonella is a highly sensitive detection method for S. enterica species which utilizes a bacteriophage cocktail designed to reduce the growth of competitor microbes in mildly selective enrichment medium. Detection of Salmonella is enhanced by means of a Salmonella-specific antibody strip targeted to lipopolysaccharide. The RapidChek® SELECT™ Salmonella method was compared to conventional enrichment and plating methods to determine the most sensitive method for detecting attenuated S. Typhi strains in human stool samples. Although traditional enrichment strategies were more sensitive to the presence of wild-type S. Typhi, RapidChek® SELECT™ Salmonella was superior at detecting attenuated strains of S. Typhi. Strains containing a wide variety of attenuating mutations were detected with equal sensitivity as the wild type by RapidChek® SELECT™ Salmonella. The presence of Vi capsule or mutations which affected O-antigen synthesis (Δpmi, ΔgalE) did not decrease the sensitivity of the RapidChek® SELECT™ Salmonella assay.
Pulido-Landínez, Martha; Sánchez-Ingunza, Roxana; Guard, Jean; do Nascimento, Vladimir Pinheiro
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 for Salmonella enterica. Salmonella was isolated from liver and spleen (71.42%), pools of organs (liver, spleen, and ovarian follicles; 25.71%), and drag swabs (2.85%). Serotype was assigned using single nucleotide polymorphisms or DNA microarray hybridization. Sixteen strains of Salmonella Enteritidis, and 13 of Salmonella Gallinarum were identified. Seven strains yielded three unique sequences, and they were designated as UN0038, UN0052, and UN0054 by intergenic sequence ribotyping. These strains were later identified as Salmonella serotypes Isangi, Braenderup, and Yoruba, respectively, by DNA microarray hybridization. The discovery that a common human pathogen (Salmonella Enteritidis) was coisolated from farms with an avian pathogen (Salmonella Gallinarum) in similar commercial brown layer hens and in different regions indicates that it is important to investigate the dynamics of Salmonella infection and determine the serotypes circulating within the same ecologic niche.
Toyofuku, Hajime; Kubota, Kunihiro; Morikawa, Kaoru
Historically, outbreaks associated with Salmonella-contaminated milk products were recognized as early as the 1950's in the United Kingdom and Bulgaria. In the 1960's and 1970's there were also a number of outbreaks related to Salmonella in various powdered milk products. As a result, Salmonella criterion was included in the Codex Code of hygienic practice for foods for infants and children. Between 1985 and 2005 at least 6 outbreaks of salmonellosis, involving as many as 250 infants, have been associated with powdered infant formula (PIF). In 2005, in France, an outbreak affecting more than 100 infants was associated with PIF contaminated with Salmonella Agona. These reported outbreaks indicated that problems persisted. Experts from two FAO/WHO Expert Consultations, held in 2004 and 2006, concluded that intrinsic contamination of PIF with Enterobacter sakazakii and Salmonella has been a cause of infection and illness in infants, including severe disease which can lead to serious developmental sequelae and death. Most of the Salmonella outbreaks associated with PIF involved unusual Salmonella serotypes, which likely aided in the recognition of these outbreaks. In many regions of the world where Salmonella serotyping is not routinely performed, identification of geographically or temporarily diffused outbreaks could be difficult. It is therefore important to use the appropriate methodology to detect unusual strains of Salmonella that cause illnesses in infants, such as the lactose-positive strain, and to perform serotyping and/or pulsed-field gel electrophoresis (PFGE) genotyping for rapid identification of Salmonella outbreaks and to establish linkages between the illness and implicated food.
Webb, Katana; Ritter, Vicki
BBL CHROMagar Salmonella was evaluated by an external food testing laboratory for the recovery of Salmonella in peanut butter using the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) procedure. The peanut butter was found to be negative for the presence of Salmonella and, therefore, was seeded with heat-stressed Salmonella at target concentrations of 0.2 and 2 CFU/25 g. The Salmonella-seeded samples remained at room temperature for 14 days before analysis to stabilize the Salmonella in the food environment. Twenty 25 g test portions from each seeded level and five 25 g samples of uninoculated control samples were processed using enrichment broths as outlined in the FDA-BAM procedure. BBL CHROMagar Salmonella-prepared plates were evaluated with the FDA reference method media (bismuth sulfite, xylose lysine desoxycholate, and Hektoen enteric agars). Fractionally positive results were obtained from the lower inoculum level of peanut butter samples. Five positive cultures were recovered from both the BBL CHROMagar Salmonella and reference methods. The two methods gave identical results for all cultures resulting in a method agreement of 100%. McNemar's chi2 test, which assesses the evidence for difference in marginal proportions between two methods, could not be evaluated because it requires one or more discrepant cultures. However, because there were no discrepant cultures, the marginal proportions for the two methods were identical; therefore, there is no evidence of a difference between the methods. This study demonstrates that the results from BBL CHROMagar Salmonella are comparable to the three reference method media for the detection of Salmonella in peanut butter using the FDA-BAM procedures.
Clancy, Meredith M; Davis, Meghan; Valitutto, Marc T; Nelson, Kenrad; Sykes, John M
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.
This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage.
Madajczak, Grzegorz; Szych, Jolanta
Despite the downward trend, Salmonella is still one of the most important bacterial intestinal infections agents. For example, in 2007 y. in Poland over 14 thousands human salmonelosis cases were notified, in 2008 y.--over 10 thousands. Among all Salmonella isolated from human source, most common (more then 80%) are two serotypes--S. Enteritidis and S. Typhimurium, but every year the number of non-typable (because of the lack I or II phase flagellar antigens, autoagglutinative or non-motility properties) Salmonella is growing. This work describes the results of the evaluation of commercially available kit PremiTest Salmonella (DSM, Netherlands), which uses the microarray hybridization in ArrayTube, for serological identification of non-typable Salmonella strains. All 37 researched strains were submitted to the Department of Bacteriology in 2007-2008 y, were reidentified according to standard operating procedures and serotyped by slide agglutination for somatic and flagellar antigens if it was possible. All strains were tested using the PremiTest Salmonella Kit, according to manufacturer instructions. In 21 cases (56%) full identification were achieved, in 5 cases (14%) additional tests were required for precise identification (Salmonella Choleraesuis or Paratyphi C, what was detailed using examination of additional biochemical features), 5 strains (14%) achieved an incomplete identification (three of them--S. diarizonae were confirmed in National Reference Laboratory for Salmonella) and 6 cases (16%) were not identified at all. The total number of recognized strains is 30 (81%). The results of present studies show, that PremiTest Salmonella Kit is useful for non-typable Salmonella identification.
Dueñas, Fernando; Rivera, Dácil; Toledo, Viviana; Tardone, Rodolfo; Hervé-Claude, Luis P; Hamilton-West, Christopher; Switt, Andrea I Moreno
Salmonella enterica can cause disease and mortality in calves. This pathogen is also a zoonosis that can be transmitted by animal contact or by food. The prevalence of Salmonella in dairy farms has been reported to range from 0 to 64%, and, due to the diversity of Salmonella serovars that can be circulating, Salmonella is an important concern for dairy production. Bacteriophages that infect Salmonella have been documented to be abundant and widely distributed in the dairy environment. The current study investigated the diversity of Salmonella serovars and Salmonella phages in 8 dairy farms with a history of diarrhea in southern Chile. A total of 160 samples from sick calves, healthy calves, and the environment were analyzed for Salmonella and phage. Isolated phages were characterized and classified by their host range using a panel of 26 Salmonella isolates representing 23 serovars. Host ranges were classified according to lysis profiles (LP) and their spatial distribution was mapped. Salmonella-infecting phages were identified, but none of the 160 samples were positive for Salmonella. A total of 45 phage isolates were obtained from sick calves (11), healthy calves (16), or the environment (18). According to their host range, 19 LP were identified, with LP1 being the most common on all 8 farms; LP1 represents phages that only lyse serogroup D Salmonella. The identification of Salmonella phages but not Salmonella in the same samples could suggest that these phages are controlling Salmonella in these farms.
Ji, Wan-Sheng; Hu, Jia-Lu; Qiu, Jun-Wen; Pan, Bo-Rong; Peng, Dao-Rong; Shi, Bing-Long; Zhou, Shao-Juan; Wu, Kai-Chun; Fan, Dai-Ming
AIM: To discover the relationship between the genotype and antigen serotype of flagellin C among Salmonella strains. METHODS: Fragment of Salmonella flagellin C in plasmid pLS408 was cloned, sequenced and compared with the corresponding sequence in other strains. Salmonella strains including two typhi strains, one paratyphoid strain, one enteritidis and one typhimurium strain were isolated from outpatients. Genome DNA was purified respectively from these clinical isolates, then the corresponding flagellin C fragment was amplified by polymerase chain reaction, and the amplification products were analyzed by agarose gel electrophoresis. RESULTS: The cloned fragment includes 582 nucleotides encoding the variable region and partial conservative region of Salmonella flagellin C in plasmid pLS408. With comparison to the corresponding sequences reported previously, there is only a little difference from other strains with the same flagellar serotype in both nucleotide and amino acid level. Specific PCR products were amplified in Salmonella strains with flagellar serotype H-1-d including S. muenchen, typhi and typhimurium, but not in S. paratyphoid C or S. enteritidis strains. CONCLUSION: In this experiment, the specificity of nucleotide sequence could be found in flagellin C central variable regions as it exists in flagellar serotypes in Salmonella. It may be helpful to developing a rapid, sensitive, accurate and PCR-based method to detect Salmonella strains with serotype H-1-d. PMID:11854918
Pabilonia, K L; Cadmus, K J; Lingus, T M; Bolte, D S; Russell, M M; Van Metre, D C; Erdman, M M
Salmonella enterica is a common zoonotic pathogen in humans. Transmission typically occurs through consumption of contaminated food products or contact with infected animals, including poultry or their environment. The objective of this study was to estimate the frequency of Salmonella contamination in the environment in poultry exhibits at agricultural fairs. Samples were collected from cages, feed, floors and tables in the exhibit and cultured for Salmonella. At least one environmental sample was positive for Salmonella in 10 of 11 fairs (91%), and Salmonella was isolated from 28 of 55 environmental samples (50.9%). Eleven different serotypes were detected. Results of this study demonstrate that environmental surfaces at agricultural fairs can be contaminated with Salmonella and could potentially serve as a route of transmission to bird owners and the general public. Poultry owners and the general public should be educated about the risks of Salmonella infection from the poultry exhibit environment. Agricultural fairs should consider instituting policies and practices to improve hygiene and mitigate the risk of zoonotic salmonellosis.
Franklin, Kristyn; Lingohr, Erika J.; Yoshida, Catherine; Anjum, Muna; Bodrossy, Levente; Clark, Clifford G.; Kropinski, Andrew M.; Karmali, Mohamed A.
We have developed a Salmonella genoserotyping array (SGSA) which rapidly generates an antigenic formula consistent with the White-Kauffmann-Le Minor scheme, currently the gold standard for Salmonella serotyping. A set of 287 strains representative of 133 Salmonella serovars was assembled to validate the array and to test the array probes for accuracy, specificity, and reproducibility. Initially, 76 known serovars were utilized to validate the specificity and repeatability of the array probes and their expected probe patterns. The SGSA generated the correct serovar designations for 100% of the known subspecies I serovars tested in the validation panel and an antigenic formula consistent with that of the White-Kauffmann-Le Minor scheme for 97% of all known serovars tested. Once validated, the SGSA was assessed against a blind panel of 100 Salmonella enterica subsp. I samples serotyped using traditional methods. In summary, the SGSA correctly identified all of the blind samples as representing Salmonella and successfully identified 92% of the antigens found within the unknown samples. Antigen- and serovar-specific probes, in combination with a pepT PCR for confirmation of S. enterica subsp. Enteritidis determinations, generated an antigenic formula and/or a serovar designation consistent with the White-Kauffmann-Le Minor scheme for 87% of unknown samples tested with the SGSA. Future experiments are planned to test the specificity of the array probes with other Salmonella serovars to demonstrate the versatility and utility of this array as a public health tool in the identification of Salmonella. PMID:21697324
Smith, S I; Seriki, A; Ajayi, A
Salmonella infections in humans can range from self-limiting gastroenteritis typically associated with non-typhoidal Salmonella (NTS) to typhoidal fever, which can be life-threatening. Salmonellosis causes considerable morbidity and mortality in both humans and animals, and has a significant socioeconomic impact worldwide. In Africa, it is difficult to evaluate the situation of salmonellosis due to the non-availability of facilities capable of performing the tests essential for the diagnosis of typhoidal and non-typhoidal Salmonella infections. This article reviews important work in the literature, including the epidemiology, disease burden, pathogenesis, genomics, diagnosis, treatment, emergence and tracking of multidrug-resistant (MDR) Salmonella infections and intercontinental transmission of Salmonella to Africa. Searches of PubMed and Google Scholar were completed and the retrieved list of relevant publications were further screened. The literature revealed that the most common form of the disease in Africa is gastroenteritis, with bacterial multiplication in intestinal submucosa and diarrhoea caused by the inflammatory response and, perhaps, also by toxins. In addition to the high burden of Salmonella infection in Africa, MDR Salmonella species is on the rise in the continent, which might pose difficulties in the treatment of the disease.
Butela, Kristen; Lawrence, Jeffrey G.
The traditional genetic tools used in Salmonella enterica serovar Typhimurium rely heavily on a high-transducing mutant of bacteriophage P22. P22 recognizes its hosts by the structure of their O-antigens, which vary among serovars of Salmonella; therefore, it cannot be used in most non-Typhimurium Salmonella, including the majority of those causing food-borne illnesses in both humans and livestock. Bacteriophage P1 infects a variety of enteric bacteria, including galE mutants of serovar Typhimurium; however, the degree to which the presence of coimmune prophages, the lack of required attachment sites or the lack of host factors act as barriers to using phage P1 in natural isolates of Salmonella is unknown. Here, we show that recombineering can be used to make virtually any serovar of Salmonella susceptible to P1 infection; as a result, P1 can be utilized for facile genetic manipulation of non-Typhimurium Salmonella, including movement of very large pathogenicity islands. A toolkit for easy manipulation of non-Typhimurium serovars of Salmonella is described. PMID:23041268
Hanson, D L; Loneragan, G H; Brown, T R; Nisbet, D J; Hume, M E; Edrington, T S
We set out to investigate whether Salmonella enterica could be recovered from various tissues of viable neonatal calves immediately following parturition. Eleven samples were aseptically collected from each of 20 calves and consisted of both left and right subiliac and prescapular lymph nodes (LN), mesenteric LN, spleen and liver, as well as intestinal tissue (including luminal contents) from the small intestine, caecum, spiral colon and rectum. In addition, a faecal sample was collected from 19 of the dams. Salmonella was recovered from at least one sample from 10 of the 20 neonates. Across all calves, Salmonella was recovered from 12·7% of all samples and from LN in particular, Salmonella was recovered from 10·0%, 5·0%, and 5·0% of subiliac, prescapular, and mesenteric LN, respectively. Within calves, Salmonella was recovered from 0% to 73% of samples and across tissues, estimates of Salmonella prevalence were greatest in the caecum (30%) but was never recovered from the right pre-scapular LN. These data provide evidence of vertical transmission from a dam to her fetus such that viable calves are born already infected and thereby not requiring faecal-oral exposure for transmission. This new knowledge ought to challenge - or at least add to - existing paradigms of Salmonella transmission dynamics within cattle herds.
Procop, Gary W; Wallace, Jacqueline D; Tuohy, Marion J; Lasalvia, Margret M; Addison, Rachel M; Reller, L Barth
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).
Marvasi, Massimiliano; Noel, Jason T; George, Andrée S; Farias, Marcelo A; Jenkins, Keith T; Hochmuth, George; Xu, Yimin; Giovanonni, Jim J; Teplitski, Max
Fresh fruits and vegetables are increasingly recognized as important reservoirs of human pathogens, and therefore, significant attention has been directed recently to understanding mechanisms of the interactions between plants and enterics, like Salmonella. A screen of tomato cultivars for their susceptibility to Salmonella revealed significant differences in the ability of this human pathogen to multiply within fruits; expression of the Salmonella genes (cysB, agfB, fadH) involved in the interactions with tomatoes depended on the tomato genotype and maturity stage. Proliferation of Salmonella was strongly reduced in the tomato mutants with defects in ethylene synthesis, perception and signal transduction. While mutation in the ripening-related ethylene receptor Nr resulted only in a modest reduction in Salmonella numbers within tomatoes, strong inhibition of the Salmonella proliferation was observed in rin and nor tomato mutants. RIN and NOR are regulators of ethylene synthesis and ripening. A commercial tomato variety heterozygous for rin was less susceptible to Salmonella under the greenhouse conditions but not when tested in the field over three production seasons. PMID:24888884
Ballard, Matt; Mills, Zachary; Owen, Drew; Hanasoge, Srinivas; Hesketh, Peter; Alexeev, Alexander
We use three-dimensional simulations to model the detection of salmonella in a complex fluid sample in a microfluidic channel. Salmonella is captured using magnetic microbeads orbiting around soft ferromagnetic discs at the microchannel bottom subjected to a rotating external magnetic field. Numerical simulations are used to model the dynamics of salmonella and microbeads throughout the detection process. We examine the effect of the channel geometry on the salmonella capture, and the forces applied to the salmonella as it is dragged through the fluid after capture. Our findings guide the design of a lab-on-a-chip device to be used for detection of salmonella in food samples in a way that ensures that salmonella captured by orbiting microbeads are preserved until they can be extracted from the system for testing, and are not washed away by the fluid flow or damaged due to the experience of excessive stresses. Such a device is needed to detect bacteria at the food source and prevention of consumption of contaminated food, and also can be used for the detection of a variety of biomaterials of interest from complex fluid samples. Support from USDA and NSF is gratefully acknowledged.
Steeb, Benjamin; Claudi, Beatrice; Burton, Neil A.; Tienz, Petra; Schmidt, Alexander; Farhan, Hesso; Mazé, Alain; Bumann, Dirk
Pathogen access to host nutrients in infected tissues is fundamental for pathogen growth and virulence, disease progression, and infection control. However, our understanding of this crucial process is still rather limited because of experimental and conceptual challenges. Here, we used proteomics, microbial genetics, competitive infections, and computational approaches to obtain a comprehensive overview of Salmonella nutrition and growth in a mouse typhoid fever model. The data revealed that Salmonella accessed an unexpectedly diverse set of at least 31 different host nutrients in infected tissues but the individual nutrients were available in only scarce amounts. Salmonella adapted to this situation by expressing versatile catabolic pathways to simultaneously exploit multiple host nutrients. A genome-scale computational model of Salmonella in vivo metabolism based on these data was fully consistent with independent large-scale experimental data on Salmonella enzyme quantities, and correctly predicted 92% of 738 reported experimental mutant virulence phenotypes, suggesting that our analysis provided a comprehensive overview of host nutrient supply, Salmonella metabolism, and Salmonella growth during infection. Comparison of metabolic networks of other pathogens suggested that complex host/pathogen nutritional interfaces are a common feature underlying many infectious diseases. PMID:23633950
Sharma, Neil; Bambusch, Lauren; Le, Thu; Hayman, Melinda; Montez, Sergio J
The InstantLabs® Salmonella Species Food Safety Kit was validated against the International Organization for Standardization (ISO) reference method* 6579:2002 for the detection of Salmonella species. The matrixes (unprocessed rolled oats, wheat flour, and oat flour) were inoculated with 1 CFU/test portion of Salmonella to generate fractional positives (5-15) in 20 inoculated samples. The inatrixes were co-inoculated with Escherichia coli O157:H7 at 2-5 times the level of Salmonella to demonstrate the potential for using the same enrichment culture in the future to detect of multiple organisms. Samples were validated using 750 g test portion enriched in FASTGRO SE at 42 ± 1°C for 16-20 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of Salmonella species in unprocessed rolled oats, wheat flour, and oat flour. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non-Salmonella species examined. Finally, the method was shown to be robust when variations to enrichment time, DNA extract hold time, and DNA volume were varied (data not shown).
Castillo, A; Mercado, I; Lucia, L M; Martínez-Ruiz, Y; Ponce de León, J; Murano, E A; Acuff, G R
Six cantaloupe farms and packing plants in South Texas (950 cantaloupe, 140 water, and 45 environmental samples), including the Rio Grande Valley area, and three farms in Colima State, Mexico (300 cantaloupe, 45 water, and 15 environmental samples), were sampled to evaluate cantaloupe contamination with Salmonella and Escherichia coli during production and processing. Samples collected from external surfaces of cantaloupes, water, and the environments of packing sheds on cantaloupe farms were examined for the presence of Salmonella and E. coli. Of a total of 1,735 samples collected, 31 (1.8%) tested positive for Salmonella. Fifteen Salmonella serotypes were isolated from samples collected in Texas, and nine from samples collected in Colima. Two serotypes (Poona and Oranienburg) that have been associated with three large Salmonella outbreaks in the United States and Canada linked to the consumption of contaminated cantaloupe were found in water samples collected at four farms (three from the United States). Susceptibility of Salmonella isolates to 10 antimicrobials was evaluated by disk diffusion. Eighty-eight percent of the isolates from the United States and Mexico were pansusceptible to the antimicrobials tested; eight isolates from the United States demonstrated an intermediate susceptibility to streptomycin and only two isolates were resistant to the same antimicrobial. From Mexico, four isolates showed an intermediate susceptibility to streptomycin and one isolate was resistant to nalidixic acid and streptomycin. Repetitive sequence-based PCR analysis of Salmonella isolates helped to trace potential sources of Salmonella contamination in source water and in subsequent water samples obtained after the filtration systems of U.S. and Mexican cantaloupe farms. No differences could be seen between the levels of Salmonella contamination in melons from both countries.
Ward, Michael P; Cowled, Brendan D; Galea, Francesca; Garner, M Graeme; Laffan, Shawn W; Marsh, Ian; Negus, Katherine; Sarre, Stephen D; Woolnough, Andrew P
Although wild pig populations are known to sometimes be infected by Salmonella, the situation in Australia has received little attention and few population-based, planned studies have been conducted. Understanding the distribution of Salmonella infections within wild pig populations allows the potential hazard posed to co-grazing livestock to be assessed. We sampled a remote and isolated wild pig population in northwestern Australia. Faecal and mesenteric lymph node samples were collected from 651 wild pigs at 93 locations and cultured for Salmonella. The population sampled was typical of wild pig populations in tropical areas of Australia, and sampling occurred approximately halfway through the population's breeding season (38% of the 229 adult females were pregnant and 35% were lactating). Overall, the prevalence of Salmonella infection based on culture of 546 freshly collected faecal samples was 36.3% (95% CI 32.1-40.7%), and based on culture of mesenteric lymph nodes was 11.9% (95% CI, 9.4-15.0%). A total of 39 serovars (139 isolates) were identified--29 in faecal samples and 24 in lymph node samples--however neither Salmonella enterica serovar Typhimurium nor Salmonella Cholerasuis were isolated. There was a significant (p<0.0001) disagreement between faecal and lymph node samples with respect to Salmonella isolation, with isolation more likely from faecal samples. Prevalence differed between age classes, with piglets being less likely to be faecal-positive but more likely to be lymph node positive than adults. The distribution of faecal-positive pigs was spatially structured, with spatial clusters being identified. Study results suggest that this population of wild pigs is highly endemic for Salmonella, and that Salmonella is transmitted from older to younger pigs, perhaps associated with landscape features such as water features. This might have implications for infection of co-grazing livestock within this environment.
Rodriguez, Andres; Pangloli, Philipus; Richards, Harold A; Mount, John R; Draughon, F Ann
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.
Foster, J W; Spector, M P
The enteric pathogen Salmonella typhimurium faces daunting odds during its voyages in the natural environment and through an infected host. It must manage stresses ranging from feast to famine, acid to base, and high to low osmolarity, among others, as well as counter various types of oxidative stress and a variety of antimicrobial peptides. The defenses used to survive these encounters can be specific or can provide cross protection to a variety of hostile conditions. Once inside a host, Salmonella spp. escape the extracellular environment and thus humoral immunity by invading professional and nonprofessional phagocytes in which a new set of challenges await. Some of these stresses are similar to those encountered in the natural environment (e.g. acid, starvation) but the bacterial response is complicated by the simultaneous occurrence of multiple stresses. S. typhimurium appears to sense various in vivo cues and responds by seducing the host signal-transduction pathways that are required to phagocytize the bacterial cell. The pathogen then calls upon components of its stress-response arsenal to survive the intracellular environment. These survival strategies enable the organism to persist in nature, where conditions are usually suboptimal, and equip the bacterium with pathogenic properties that, if successful, will provide it with a very rich and stress-free growth environment, a dead host.
Sanderson, K E; Hessel, A; Rudd, K E
We present edition VIII of the genetic map of Salmonella typhimurium LT2. We list a total of 1,159 genes, 1,080 of which have been located on the circular chromosome and 29 of which are on pSLT, the 90-kb plasmid usually found in LT2 lines. The remaining 50 genes are not yet mapped. The coordinate system used in this edition is neither minutes of transfer time in conjugation crosses nor units representing "phage lengths" of DNA of the transducing phage P22, as used in earlier editions, but centisomes and kilobases based on physical analysis of the lengths of DNA segments between genes. Some of these lengths have been determined by digestion of DNA by rare-cutting endonucleases and separation of fragments by pulsed-field gel electrophoresis. Other lengths have been determined by analysis of DNA sequences in GenBank. We have constructed StySeq1, which incorporates all Salmonella DNA sequence data known to us. StySeq1 comprises over 548 kb of nonredundant chromosomal genomic sequences, representing 11.4% of the chromosome, which is estimated to be just over 4,800 kb in length. Most of these sequences were assigned locations on the chromosome, in some cases by analogy with mapped Escherichia coli sequences. PMID:7603411
Baek, Jonghwan; Lee, Jiyoung; Yoon, Kihoon; Lee, Hyunwoo
Increasing evidence indicates that many, if not all, small genes encoding proteins ≤100 aa are missing in annotations of bacterial genomes currently available. To uncover unannotated small genes in the model bacterium Salmonella enterica Typhimurium 14028s, we used the genomic technique ribosome profiling, which provides a snapshot of all mRNAs being translated (translatome) in a given growth condition. For comprehensive identification of unannotated small genes, we obtained Salmonella translatomes from four different growth conditions: LB, MOPS rich defined medium, and two infection-relevant conditions low Mg2+ (10 µM) and low pH (5.8). To facilitate the identification of small genes, ribosome profiling data were analyzed in combination with in silico predicted putative open reading frames and transcriptome profiles. As a result, we uncovered 130 unannotated ORFs. Of them, 98% were small ORFs putatively encoding peptides/proteins ≤100 aa, and some of them were only expressed in the infection-relevant low Mg2+ and/or low pH condition. We validated the expression of 25 of these ORFs by western blot, including the smallest, which encodes a peptide of 7 aa residues. Our results suggest that many sequenced bacterial genomes are underannotated with regard to small genes and their gene annotations need to be revised. PMID:28122954
Salmonella enterica serovar Typhi (S. Typhi) is the cause of typhoid fever, a life-threatening bacterial infection that is very common in the developing world. Recent spread of antimicrobial resistant isolates of S. Typhi makes typhoid fever, a global public health risk. Despite being a common disease, still very little is known about the molecular mechanisms underlying typhoid fever and S. Typhi pathogenesis. In contrast to other Salmonellae, S. Typhi can only infect humans. The molecular bases of this human restriction are mostly unknown. Recent studies identified a novel pathway that contributes to S. Typhi human restriction and is required for killing S. Typhi in macrophages of nonsusceptible species. The small Rab GTPase Rab32 and its guanine nucleotide exchange factor BLOC-3 are the critical components of this pathway. These proteins were already well known as important regulators of intracellular membrane transport. In particular, they are central for the transport of enzymes that synthetize melanin in pigment cells. The recent findings that Rab32 and BLOC-3 are required for S. Typhi host restriction point out to a novel mechanism restricting the growth of bacterial pathogen, dependent on the transport of still unknown molecule(s) to the S. Typhi vacuole. The identification of this novel antimicrobial pathway constitutes a critical starting point to study molecular mechanisms killing bacterial pathogens and possibly identify novel antimicrobial molecules.
Cohen, J O; Britt, L E; Harrell, W K
This study concerns the preparation of reagents for identifying the somatic O antigens of Salmonella enteritidis. Coagglutination reagents (COAGs) with antibody fixed to killed and stabilized protein A-bearing staphylococci were prepared with antisera which were used for identifying the somatic O antigens of S. enteritidis by the slide agglutination test. The reactions of the COAGs were compared with those obtained with the grouping antisera in routine slide agglutination tests in which 41 or more serologically different Salmonella strains, representing most of the known groups, were used. One-third of the COAGs gave identical reactions to those of the slide agglutination antisera. The reactions of the other COAGs varied from the slide agglutination antisera results, some by many reactions and others by only a few. The coagglutination procedure was more reactive than the routine slide agglutination test and resulted in cross-reactions which were not observed in the original grouping antisera. More COAGs were specific when they were tested with alcohol-treated cultures than with live cultures. Coagglutination conserves antiserum, allowing about 12 times as many tests for a given volume of group-specific glycerolized antiserum as does the slide agglutination method. PMID:6203928
Baek, Jonghwan; Lee, Jiyoung; Yoon, Kihoon; Lee, Hyunwoo
Increasing evidence indicates that many, if not all, small genes encoding proteins ≤100 aa are missing in annotations of bacterial genomes currently available. To uncover unannotated small genes in the model bacterium Salmonella enterica Typhimurium 14028s, we used the genomic technique ribosome profiling, which provides a snapshot of all mRNAs being translated (translatome) in a given growth condition. For comprehensive identification of unannotated small genes, we obtained Salmonella translatomes from four different growth conditions: LB, MOPS rich defined medium, and two infection-relevant conditions low Mg(2+) (10 µM) and low pH (5.8). To facilitate the identification of small genes, ribosome profiling data were analyzed in combination with in silico predicted putative open reading frames and transcriptome profiles. As a result, we uncovered 130 unannotated ORFs. Of them, 98% were small ORFs putatively encoding peptides/proteins ≤100 aa, and some of them were only expressed in the infection-relevant low Mg(2+) and/or low pH condition. We validated the expression of 25 of these ORFs by western blot, including the smallest, which encodes a peptide of 7 aa residues. Our results suggest that many sequenced bacterial genomes are underannotated with regard to small genes and their gene annotations need to be revised.
Ahmer, Brian M. M.; Gunn, John S.
Salmonella spp. are major cause of human morbidity and mortality worldwide. Upon entry into the human host, Salmonella spp. must overcome the resistance to colonization mediated by the gut microbiota and the innate immune system. They successfully accomplish this by inducing inflammation and mechanisms of innate immune defense. Many models have been developed to study Salmonella spp. interaction with the microbiota that have helped to identify factors necessary to overcome colonization resistance and to mediate disease. Here we review the current state of studies into this important pathogen/microbiota/host interaction in the mammalian gastrointestinal tract. PMID:21772831
Chun, Doki; Seol, Sung Yong; Tak, Ryunbin; Park, Cheong Kyu
In a study of the effect of glycerin in transport media on Vibrio parahaemolyticus and Salmonella, it was found that a concentration of 30% glycerin was highly inhibitory for V. parahaemolyticus and to a lesser degree for Salmonella. The incorporation of peptone or human feces in media did not reduce the inhibitory effect of glycerin. In media with 15% glycerin, viable counts of V. parahaemolyticus and Salmonella increased after 24 hr of incubation both in the presence and absence of feces. Due to the concurrent increase in the total bacterial count in the media containing feces, no enrichment effect was noted. PMID:4565633
Objective: To isolate an anti-Salmonella bacterium that may control pathogen load in persistently-infected cattle herds. Animals: 24 Holstein calves. Procedures: An Escherchia coli (designated as P8E5) that possesses anti-Salmonella activity was isolated from Salmonella negative bovine feces ob...
Calva, Edmundo; Puente, José L.; Zaidi, Mussaret B.
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
Kim, Giyoung; Moon, Ji-Hea; Moh, Chang-Yeon; Lim, Jong-guk
Rapid detection of pathogenic Salmonella in food products is extremely important for protecting the public from salmonellosis. The objective of the present study was to explore the feasibility of using a microfluidic nano-biosensor to rapidly detect pathogenic Salmonella. Quantum dot nanoparticles were used to detect Salmonella cells. For selective detection of Salmonella, anti-Salmonella polyclonal antibodies were covalently immobilized onto the quantum dot surface. To separate and concentrate the cells from the sample, superparamagnetic particles and a microfluidic chip were used. A portable fluorometer was developed to measure the fluorescence signal from the quantum dot nanoparticles attached to Salmonella in the samples. The sensitivity for detection of pathogenic Salmonella was evaluated using serially diluted Salmonella Typhimurium in borate buffer and chicken extract. The fluorescence response of the nano-biosensor increased with increasing cell concentration. The detection limit of the sensor was 10(3) CFU/mL Salmonella in both borate buffer and food extract.
Schleker, Sylvia; Kshirsagar, Meghana; Klein-Seetharaman, Judith
Salmonellosis is the most frequent foodborne disease worldwide and can be transmitted to humans by a variety of routes, especially via animal and plant products. Salmonella bacteria are believed to use not only animal and human but also plant hosts despite their evolutionary distance. This raises the question if Salmonella employs similar mechanisms in infection of these diverse hosts. Given that most of our understanding comes from its interaction with human hosts, we investigate here to what degree knowledge of Salmonella–human interactions can be transferred to the Salmonella–plant system. Reviewed are recent publications on analysis and prediction of Salmonella–host interactomes. Putative protein–protein interactions (PPIs) between Salmonella and its human and Arabidopsis hosts were retrieved utilizing purely interolog-based approaches in which predictions were inferred based on available sequence and domain information of known PPIs, and machine learning approaches that integrate a larger set of useful information from different sources. Transfer learning is an especially suitable machine learning technique to predict plant host targets from the knowledge of human host targets. A comparison of the prediction results with transcriptomic data shows a clear overlap between the host proteins predicted to be targeted by PPIs and their gene ontology enrichment in both host species and regulation of gene expression. In particular, the cellular processes Salmonella interferes with in plants and humans are catabolic processes. The details of how these processes are targeted, however, are quite different between the two organisms, as expected based on their evolutionary and habitat differences. Possible implications of this observation on evolution of host–pathogen communication are discussed. PMID:25674082
Higgins, J P; Higgins, S E; Wolfenden, A D; Henderson, S N; Torres-Rodriguez, A; Vicente, J L; Hargis, B M; Tellez, G
In the present study, a series of experiments were conducted to evaluate the ability of a combination of 3 ATCC lactobacilli (LAB3) or a commercially available probiotic culture (PROB) to reduce Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) in broiler chicks. Additionally, we varied the timing of PROB administration in relationship to Salmonella challenge and determined the influence on recovery of enteric Salmonella. In experiments 1 to 3, chicks were randomly assigned to treatment groups and were then challenged via oral gavage with Salmonella Enteritidis. Chicks were treated 1 h after Salmonella Enteritidis challenge with LAB3 or PROB. Twenty-four hours posttreatment, cecal tonsils were collected for recovery of enteric Salmonella. In experiments 4 to 7, day-of-hatch chicks were randomly assigned to treatment groups and were then treated with PROB via oral gavage and placed into pens. Chicks were challenged with Salmonella Enteritidis 24 h after treatment via oral gavage. At 24 h after Salmonella Enteritidis challenge, cecal tonsils were collected and recovery of enteric Salmonella was determined. In experiments 8 to 10, 1-d-old chicks were randomly assigned to treatment groups and were then challenged via oral gavage with Salmonella Enteritidis and placed into pens. Chicks were treated 24 h after challenge with PROB via oral gavage. Twenty-four hours post PROB treatment, cecal tonsils were collected and enriched as described above. It was found that PROB significantly reduced cecal Salmonella Enteritidis recovery 24 h after treatment as compared with controls or LAB3-treated chicks in experiments 1 to 3 (P<0.05). Administration of PROB 24 h before Salmonella Enteritidis challenge significantly reduced recovery of Salmonella Enteritidis in 2 out of 4 experiments and no reduction in cecal Salmonella Enteritidis was observed when chicks were challenged with Salmonella Enteritidis and treated 24 h later with PROB. These data demonstrate that PROB
Koluman, A; Celik, G; Unlu, T
Background and Objectives The significant rise in food borne infections is mainly caused by Campylobacter spp., Salmonella serovars and Verotoxigenic Escherichia coli. As the emerging food borne pathogens cause disease, more studies have been conducted for rapid detection of these pathogens. The combination of immunomagnetic separation and polymerase chain reaction (IMS-PCR) is the most accurate and rapid test preferred by almost every researcher. Fourier Transform Infrared Spectroscopy (FTIR) is preferred for being a new, user friendly and rapid technique in microbiological analyses. The main aim of this study is to detect application of IMS-FTIR for Salmonella identification from foods in a short time with a higher sensitivity. Materials and Methods Conventional Culture Technique (CC), IMS-CC, IMS-PCR and IMS-FTIR techniques were compared with each other for rapid detection in artificially contaminated minced beef with Salmonella Typhimurium, as of the 2nd, 4th and 8th hours of contamination. The method was evaluated in different food matrices and sensitivity, specifity and overall recovery was calculated. Results The results indicate that IMS-FTIR can detect S. Typhimurium as of the 8th hour with sensitivity of 95.6667, accuracy of 91.69329, false positive ratio of 0.04333 and overall recovery of 95.66%. Conclusion It can be suggested that the IMS-FTIR method is capable of detecting S.Typhimurium in a short time with lower cost. PMID:22783456
Williams, Katherine; Gokulan, Kuppan; Shelman, Diamond; Akiyama, Tatsuya; Khan, Ashraf; Khare, Sangeeta
Cytolethal distending toxin B (cdtB) is a conserved virulence factor in Salmonella enterica serovar Typhi. Here we report the presence and functionality of cdtB in some nontyphoidal Salmonella (NTS) serovars, including Salmonella Javiana (cdtB+wt S. Javiana), isolated from imported food. To understand the role of cdtB in NTS serovars, a deletion mutant (cdtB(-)ΔS. Javiana) was constructed. Macrophages were infected with cdtB+wt S. Javiana (wild type), cdtB(-)Δ S. Javiana (mutant), and cdtB-negative NTS serovar (S. Typhimurium). Cytotoxic activity and transcription level of genes involved in cell death (apoptosis, autophagy, and necrosis) were assessed in infected macrophages. The cdtB+wt S. Javiana caused cellular distension as well as high degree of vacuolization and presence of the autophagosome marker LC3 in infected macrophages as compared with cdtB(-)ΔS. Javiana. The mRNA expression of genes involved in the induction of autophagy in response to toxin (Esr1 and Pik3C3) and coregulators of autophagy and apoptosis (Bax and Cyld) were significantly upregulated in cdtB(+)wt S. Javiana-infected macrophages. As autophagy destroys internalized pathogens in addition to the infected cell, it may reduce the spread of infection.
Osman, Kamelia M; Yousef, Ashgan M M; Aly, Mona M; Radwan, Moustafa I
The occurrence of Salmonella in 750 birds was assessed. The samples included the internal organs (caecal pouches, yolk sac, liver, and lung) of imported 1-day-old chicks (n = 150), grandparent chicks (n = 150), breeder chicks (n = 150), ducklings (n = 150), and turkey poults (n = 150), and paper-lined boxes (n = 250). Salmonellae isolated from the internal organs and paper-lined box of 1-day-old chicks, ducklings, and poults were mostly evident from the paper-lined box followed by caecal samples. Imported 1-day-old grandparent flocks were Salmonella free. Although 23.3% of the imported breeder flocks were positive for Salmonella, the imported duckling flocks and day-old turkey poults exhibited 19.3% and 12.6%, respectively. The widest diversity in isolated salmonellae was from the 1-day-old chicks where Salmonella Newport, Salmonella Kentucky, Salmonella Enteritidis, Salmonella Shubra, Salmonella Saintpaul, and Salmonella Agona were isolated. On the other hand, two Salmonella serovars were isolated from the imported breeders, Salmonella Shubra and Salmonella Shipley, and from the imported ducklings, Salmonella Shubra and Salmonella Saintpaul. The three Salmonella serovars isolated from the imported day-old turkey poults were Salmonella Shubra, Salmonella Newport, and Salmonella Saintpaul. The high percentage and diversity of Salmonella isolation from the imported birds cause concern because of the zoonotic potential of this agent and its economical importance to the local commercial poultry breeding industry. From 80 samples investigated for Salmonella, the positivity of the standard microbiological technique method was 17.5% and of the polymerase chain reaction method (Salmonella-specific invA gene) was 22.5%. The concordance between the two methods was 90% (k = 0.850). Our results indicated that the polymerase chain reaction approach is better than culturing for detecting Salmonella in poultry samples when using the preenriched medium combinations used in this
Sato, Y; Fukui, S; Kurusu, H; Kitazawa, I; Kuwamoto, R; Aoyagi, T
Salmonella typhimurium infection occurred in a children's zoo where 11 fowl and 85 mammals were kept. Initially, the guinea pigs were infected and transmitted the infection to the fowl and rabbits. These mammals responded to medication and cleared of the infection; however, the birds were judged to contain excreters despite four regimens of treatment with antibiotics. Cloacal swabs were taken from all the birds. One turkey was positive for Salmonella and was destroyed. Pooled fecal samples from the birds were again positive. All the birds were tested serologically, and two birds, a goose and a turkey, were positive with Salmonella pullorum-gallinarum antigen, which was assumed to be a cross reaction with S. typhimurium antigen. The two birds were destroyed and the goose yielded Salmonella. The infection was finally eradicated, and the serologic examination was considered to be the most useful procedure for detection of the excreters.
López-Garrido, Javier; Puerta-Fernández, Elena; Cota, Ignacio; Casadesús, Josep
Invasion of the intestinal epithelium is a critical step in Salmonella enterica infection and requires functions encoded in the gene cluster known as Salmonella Pathogenicity Island 1 (SPI-1). Expression of SPI-1 genes is repressed by L-arabinose, and not by other pentoses. Transport of L-arabinose is necessary to repress SPI-1; however, repression is independent of L-arabinose metabolism and of the L-arabinose-responsive regulator AraC. SPI-1 repression by L-arabinose is exerted at a single target, HilD, and the mechanism appears to be post-translational. As a consequence of SPI-1 repression, l-arabinose reduces translocation of SPI-1 effectors to epithelial cells and decreases Salmonella invasion in vitro. These observations reveal a hitherto unknown role of L-arabinose in gene expression control and raise the possibility that Salmonella may use L-arabinose as an environmental signal.
Padron, A. P.; Dockstader, W. B.
Triple Sugar Iron Agar does not reveal hydrogen sulfide production by all Salmonella organisms nor does it permit clear-cut separation of those nonsalmonellae which produce H2S. Numerous media with varied combinations of nutrients, inhibitors, selective agents, pH levels, and metal salts were tested for H2S production of cultures of Salmonella, Citrobacter, Edwardsiella, Arizona, Proteus, Providencia, Klebsiella, and Enterobacter. An agar medium has been devised which promotes growth and H2S production (generally within 6 hr) by Salmonella, Arizona, and Edwardsiella but which inhibits hydrogen sulfide production or growth of all other gram-negative organisms tested (including Citrobacter) or inhibits both. The use of this medium should facilitate the selection and identification of Salmonella. PMID:4557561
... The source of infection was identified as dry dog food produced at a manufacturing plant in Pennsylvania. ... investigation was the first to identify contaminated dry dog food as a source of human Salmonella infections ...
Gonzalez-Escobedo, Geoffrey; Gunn, John S
The host-pathogen interactions occurring in the gallbladder during Salmonella Typhi colonization contribute to typhoid fever pathogenesis during the acute and chronic stages of disease. The gallbladder is the primary reservoir during chronic typhoid carriage. In this organ, Salmonella encounters host-barriers including bile, immunoglobulins, and mucus. However, the bacterium possesses mechanisms to resist and persist in this environment, in part by its ability to attach to and invade into the gallbladder epithelium. Such persistence in the gallbladder epithelium contributes to chronic carriage. In addition, patients harboring gallstones in their gallbladders have increased risk of becoming carriers because these abnormalities serve as a substrate for Salmonella biofilm formation. Our laboratory has studied the Salmonella interactions in this specific environment by developing in vitro methods that closely mimic the gallbladder and gallstones niches. These methods are reproducible and provide a platform for future studies of acute and chronic bacterial infections in the gallbladder.
López-Garrido, Javier; Puerta-Fernández, Elena; Cota, Ignacio; Casadesús, Josep
Invasion of the intestinal epithelium is a critical step in Salmonella enterica infection and requires functions encoded in the gene cluster known as Salmonella Pathogenicity Island 1 (SPI-1). Expression of SPI-1 genes is repressed by l-arabinose, and not by other pentoses. Transport of l-arabinose is necessary to repress SPI-1; however, repression is independent of l-arabinose metabolism and of the l-arabinose-responsive regulator AraC. SPI-1 repression by l-arabinose is exerted at a single target, HilD, and the mechanism appears to be post-translational. As a consequence of SPI-1 repression, l-arabinose reduces translocation of SPI-1 effectors to epithelial cells and decreases Salmonella invasion in vitro. These observations reveal a hitherto unknown role of l-arabinose in gene expression control and raise the possibility that Salmonella may use L-arabinose as an environmental signal. PMID:25991823
Stroud, R.K.; Roelke, M.E.
Salmonella enteritidis was isolated from the brain of a neonatal northern fur seal (Callorhinus ursinus) with gross and microscopic lesions of meningoencephalomyelitis. Microscopic lesions in the liver and lung suggested septicemia.
Saporito, Laura; Colomba, Claudia; Scarlata, Francesco; Li Vecchi, Vatentina; Mammina, Caterina; Titone, Lucina
The aim of our study was to evaluate the role of Salmonella spp in children hospitalised for acute gastroenteritis, and to study clinical and microbiological features of paediatric salmonellosis in our geographical area. In all, 540 patients admitted from March to September 2003 with symptoms of acute enteritis to the Infectious Diseases department of the "G. Di Cristina" hospital in Palermo were enrolled. Stool samples were collected within 48 hours of admission and tested for intestinal pathogens (bacterial, viral, parasites). Salmonella spp was detected in 18.5% of samples. The median age of infected children was 4.5 years. Salmonella enteritidis (49%) and Salmonella typhimurium (37%) were the most commonly identified genotypes. S. enteritidis infection was more frequently characterized by vomiting (65.3%) and dehydration (61.2%). Bloody diarrhoea was more common in S. typhimurium infection (40.5%). All strains were susceptible to ceftriaxone, while 40% of strains were resistant to tetracyclines and 37% to ampicillin.
Chin'ombe, Nyasha; Ruhanya, Vurayai
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.
Nastasi, A; Mammina, C; Salsa, L
Salmonella bongori 48:z 35 :- was first isolated from a lizard in Chad in 1966 and was classified as a biochemically atypical strain of the subgenus I of Kauffmann. Successively, some additional strains with different antigenic formulas but similar bioche
Background Salmonella contaminated animal feed is a major source for introducing Salmonella into the animal derived food chain. Because soybeans frequently are contaminated with Salmonella, soybean meal used as animal feed material, a by-product of a “crushing plant” which produces oil from soybeans, can be important source of Salmonella in the animal feed. We report the successful control of Salmonella from 1994 to 2012 in a Norwegian crushing plant producing soybean meal from imported soy beans. The results are based on an officially supervised HACCP based program including annual testing of around 4000 samples. Results During the 19-year period, 34% of samples collected during unloading of ships delivering soybeans yielded Salmonella; the proportion of samples from ships that yielded Salmonella varied from 12-62% each year. Dust samples from all shiploads from South America yielded Salmonella. In total 94 serovars of Salmonella were isolated, including nine (90%) of the EU 2012 top ten serovars isolated from clinical cases of salmonellosis in humans, including major animal pathogenic serovars like Spp. Typhimurium and Enteritidis. The effectiveness of the HACCP based control was indicated by a low prevalence of Salmonella contamination in the clean area of the plant, which is considered to be the main reason for the successful prevention of Salmonella in the end product. Despite extensive testing, no sample from the finished soybean meal product was found to be Salmonella contaminated. Conclusions This study shows that a HAACP-based control program in a soybean crushing plant can produce Salmonella free soybean meal despite frequent Salmonella contamination of raw soybeans. That approach is suggested as an effective way to minimize the risk of Salmonella exposure of the animal feed mills and contamination of the subsequent animal feed chain. PMID:25011553
Lewis, Charles E; Bemis, David A; Ramsay, Edward C
A high prevalence of fecal Salmonella shedding in a collection of healthy exotic felids precipitated a change to two new commercially available feline diets. One year after initiation of the new diets, 18 fecal samples from individual felines, their exhibits, and representative samples of the diets were cultured for Salmonella spp. Only one culture grew a Salmonella sp. Salmonella uganda was cultured from the feces of one snow leopard (Felis uncia). Feeding a diet with minimal to no Salmonella contamination lowered Salmonella shedding rates in this collection of captive exotic felids.
Narayanan, Lakshmi A.; Edelmann, Mariola J.
The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host–pathogen interactions can help to understand the general function of the ubiquitination pathway in the host cell. PMID:25505465
Narayanan, Lakshmi A; Edelmann, Mariola J
The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin function during infection with Salmonella enterica Typhimurium and hypothesize how these studies on the host-pathogen interactions can help to understand the general function of the ubiquitination pathway in the host cell.
Lento, F G
The spreading of Salmonella Wien at Gela is proved by its isolation from the faeces of twelve patients hospitalized in the isolation department of Vittorio Emanuele II Hospital at Gela (Italy) from May to October in 1976. The isolated Salmonella shows the same serological characteristics and the same features of resistance to the antibiotics of the stocks responsable for the epidemics in Algeria and in France.
Cevallos-Cevallos, Juan M; Danyluk, Michelle D; Gu, Ganyu; Vallad, Gary E; van Bruggen, Ariena H C
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.
Gonzalez-Escobedo, Geoffrey; Gunn, John S
Although typhoid fever has been intensively studied, chronic typhoid carriage still represents a problem for the transmission and persistence of the disease in areas of endemicity. This chronic state is highly associated with the presence of gallstones in the gallbladder of infected carriers upon which Salmonella can form robust biofilms. However, we hypothesize that in addition to gallstones, the gallbladder epithelium aids in the establishment/maintenance of chronic carriage. In this work, we present evidence of the role of the gallbladder epithelium in chronic carriage by a mechanism involving invasion, intracellular persistence, and biofilm formation. Salmonella was able to adhere to and invade polarized gallbladder epithelial cells apically in the absence and presence of bile in a Salmonella pathogenicity island 1 (SPI-1)-dependent manner. Intracellular replication of Salmonella was also evident at 12 and 24 h postinvasion. A flowthrough system revealed that Salmonella is able to adhere to and form extensive bacterial foci on gallbladder epithelial cells as early as 12 h postinoculation. In vivo experiments using a chronic mouse model of typhoid carriage showed invasion and damage of the gallbladder epithelium and lamina propria up to 2 months after Salmonella infection, with an abundant presence of macrophages, a relative absence of neutrophils, and extrusion of infected epithelial cells. Additionally, microcolonies of Salmonella cells were evident on the surface of the mouse gallbladder epithelia up to 21 days postinfection. These data reveal a second potential mechanism, intracellular persistence and/or bacterial aggregation in/on the gallbladder epithelium with luminal cell extrusion, for Salmonella maintenance in the gallbladder.
Heres, L; Engel, B; van Knapen, F; de Jong, M C M; Wagenaar, J A; Urlings, H A P
The presence of Salmonella in chickens is a problem because poultry meat is recognized as a source of human salmonellosis. Fermented feed has characteristics like a high number of lactobacilli and high concentration of lactic acid, which could make chickens less susceptible for infection with Salmonella. Fermented feed might therefore prevent the colonization of chickens with Salmonella. Two studies were performed to quantify the effect of fermented liquid feed on the susceptibility of broilers for Salmonella. The fermented feed was prepared by fermenting a dry broiler feed supplemented with 1.4 parts of water. Lactobacillus plantarum was used for fermentation. The fermented liquid feed (FLF) contained 10(9) to 10(10) cfu lactobacilli per gram, and the pH was 4. Individually housed control chickens and FLF-fed chickens were inoculated with 10(2) to 10(7) cfu Salmonella enteritidis (SE). Colonization was estimated by cloacal swabs and quantitative caecal culture. The proportion of SE-shedding chickens was decreased in FLF-fed chickens. FLF-fed chickens required a longer time after inoculation or a higher inoculation dose to get the same proportion of infected chickens in comparison with dry feed-fed chickens. The level of cecal colonization with Salmonella in the ceca was not different at the end of the experimental period. The results indicate that FLF can hamper the introduction of Salmonella in broiler flocks because the chickens are less susceptible for infection. Fermented liquid feed might therefore be a new hurdle in the strategy to control Salmonella in chicken flocks.
Gurnik, Simone; Ahmad, Aaminah; Blimkie, Travis; Murphy, Stephanie A.; Kropinski, Andrew M.; Nash, John H. E.
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
Palumbo, S A; Huhtanen, C N; Smith, J L
Salmonella senftenberg 775W added to frankfurter emulsion was killed during normal processing in the smoke house when internal product temperature was 71.1 C (160 F) or above. The thermal destruction point of S. senftenberg 775W in frankfurters (temperature at which no viable cells were detected) was a function of the length of time of the process rather than of the starting number of cells. Heating of frankfurters to 73.9 C (165 F) substantially reduced the total non-salmonella count. For total non-salmonella bacterial flora and salmonella, relatively little thermal destruction occurred below 43.3 C (110 F). The heating step can bring about a 7-log cycle decrease (10(8) to 10(1)/g) of bacteria present in the raw emulsion. The flora of this high-bacteriological-count raw emulsion was predominantly gram-negative rods. Variation in the number of bacteria (both total and salmonella) surviving at various temperatures during processing was attributed to slight variations in the temperature pattern of the smoke house during its operation. An integration process was devised which allowed calculation of exposure to temperatures above 110 F (43.3 C) on the basis of degree-minutes. Plots of degree-minutes versus log of surviving bacteria were linear. The salmonella plot had a greater slope than that of the total non-salmonella flora, indicating that salmonellae are more heat sensitive than the bacterial population as a whole. The predominant bacteria surviving the heating step were micrococci. These micrococci were able to increase in number in or on the frankfurters during storage at 5 C.
Glass, Kathryn; Veitch, Mark; Wardell, Rebecca; Polkinghorne, Ben; Dobbins, Timothy; Lal, Aparna; Kirk, Martyn D.
Salmonella is a key cause of foodborne gastroenteritis in Australia and case numbers are increasing. We used negative binomial regression to analyze national surveillance data for 2000–2013, for Salmonella Typhimurium and non-Typhimurium Salmonella serovars. We estimated incidence rate ratios adjusted for sex and age to show trends over time. Almost all states and territories had significantly increasing trends of reported infection for S. Typhimurium, with states and territories reporting annual increases as high as 12% (95% confidence interval 10–14%) for S. Typhimurium in the Australian Capital Territory and 6% (95% CI 5–7%) for non-Typhimurium Salmonella in Victoria. S. Typhimurium notification rates were higher than non-Typhimurium Salmonella rates in most age groups in the south eastern states of Australia, while non-Typhimurium rates were higher in most age groups elsewhere. The S. Typhimurium notification rate peaked at 12–23 months of age and the non-Typhimurium Salmonella notification rate peaked at 0–11 months of age. The age-specific pattern of S. Typhimurium cases suggests a foodborne origin, while the age and geographic pattern for non-Typhimurium may indicate that other transmission routes play a key role for these serovars. PMID:27732615
Jajere, Saleh Mohammed; Onyilokwu, Samson Amali; Adamu, Nuhu Bala; Atsanda, Naphtali Nayamanda; Saidu, Adamu Saleh; Adamu, Shuaibu Gidado; Mustapha, Fatima Bukar
The prevalence and antimicrobial sensitivity of Salmonella from dogs in Maiduguri Metropolis were determined using standard bacteriological methods to assess the risk of possible transmission of Salmonella infection from dogs to humans. Of 119 samples, Salmonella was isolated from 52 (43.7%). Males had higher prevalence of 50.0% compared with 34.7% in females (P < 0.05). Dogs older than 24 months had higher prevalence of 61.0% and the lowest was seen in dogs aged 13-24 months (P < 0.05). The prevalence of 31.8%, 41.2%, and 58.8% was observed in dogs aged 3-6, 10-12, and 7-9 months, respectively. High prevalence of 49.5% was observed in Mongrels, while Terrier and Alsatian breeds had 30.0% and 8.3%, respectively. Salmonella isolates from Alsatian and Terrier breeds showed about 100% susceptibility to all the tested antimicrobials. Higher percentage of the Salmonella isolates from Mongrels also showed susceptibility to ciprofloxacin (89.7%), amoxicillin (87.6%), vancomycin (86.6%), and chloramphenicol (84.5%). However about 50% of these isolates showed resistance to ofloxacin. The carrier status of Salmonella is high among dogs especially Mongrels. Therefore good environmental hygiene, discouraging straying coupled with feeding of dogs with properly cooked and uncontaminated feeds was recommended to mitigate risk of human salmonellosis.
Davies, Mark R; Broadbent, Sarah E; Harris, Simon R; Thomson, Nicholas R; van der Woude, Marjan W
The immunodominant lipopolysaccharide is a key antigenic factor for Gram-negative pathogens such as salmonellae where it plays key roles in host adaptation, virulence, immune evasion, and persistence. Variation in the lipopolysaccharide is also the major differentiating factor that is used to classify Salmonella into over 2600 serovars as part of the Kaufmann-White scheme. While lipopolysaccharide diversity is generally associated with sequence variation in the lipopolysaccharide biosynthesis operon, extraneous genetic factors such as those encoded by the glucosyltransferase (gtr) operons provide further structural heterogeneity by adding additional sugars onto the O-antigen component of the lipopolysaccharide. Here we identify and examine the O-antigen modifying glucosyltransferase genes from the genomes of Salmonella enterica and Salmonella bongori serovars. We show that Salmonella generally carries between 1 and 4 gtr operons that we have classified into 10 families on the basis of gtrC sequence with apparent O-antigen modification detected for five of these families. The gtr operons localize to bacteriophage-associated genomic regions and exhibit a dynamic evolutionary history driven by recombination and gene shuffling events leading to new gene combinations. Furthermore, evidence of Dam- and OxyR-dependent phase variation of gtr gene expression was identified within eight gtr families. Thus, as O-antigen modification generates significant intra- and inter-strain phenotypic diversity, gtr-mediated modification is fundamental in assessing Salmonella strain variability. This will inform appropriate vaccine and diagnostic approaches, in addition to contributing to our understanding of host-pathogen interactions.
Gu, Ganyu; Cevallos-Cevallos, Juan M; van Bruggen, Ariena H C
Internal contamination of Salmonella in plants is attracting increasing attention for food safety reasons. In this study, three different tomato cultivars "Florida Lanai", "Crown Jewel", "Ailsa Craig" and the transgenic line Sp5 of "Ailsa Craig" were inoculated with 1 µl GFP-labeled Salmonella Typhimurium through guttation droplets at concentrations of 10(9) or 10(7) CFU/ml. Survival of Salmonella on/in tomato leaves was detected by both direct plating and enrichment methods. Salmonella cells survived best on/in the inoculated leaves of cultivar "Ailsa Craig" and decreased fastest on/in "Florida Lanai" leaves. Increased guttation in the abscisic acid over-expressing Sp5 plants may have facilitated the entrance of Salmonella into leaves and the colonization on the surface of tomato leaves. Internalization of Salmonella Typhimurium in tomato leaves through guttation drop inoculation was confirmed by confocal laser microscopy. For the first time, convincing evidence is presented that S. enterica can enter tomato leaves through hydathodes and move into the vascular system, which may result in the internal translocation of the bacteria inside plants.
El-Tras, Wael F; Tayel, Ahmed A; Samir, Ahmed
Salmonella Enteritidis is a communicable zoonotic bacterium. The present investigation was done to evaluate the potential occurrence of Salmonella Enteritidis in laying hen farms and its contamination pathways. Samples were collected from 10 laying hen farms located in the Delta of Egypt. Cloacal swabs (n=300), eggshell swabs (n=400), and hand swabs from egg packagers (n=38) were collected. Pools of ovary and oviduct were obtained from 150 hens; all samples were examined for the presence of Salmonella Enteritidis. Results indicated that Salmonella Enteritidis may initially occupy in ovary, oviduct, and cloaca. The risk for eggshell contamination is highly impending from laying hen flocks infected with Salmonella Enteritidis with percentage of >30%. Farms having eggshell contamination percentage of >60% with Salmonella Enteritidis provided a high risk for packagers' hand contamination. Questionnaire of egg packagers specified that seven out of the eight smoker packagers suffered from repeated Salmonellosis. Thus, smoking during egg packing process could be considered as an exposure factor to contract the infection via hand-cigarette-mouth route.
Ray, K A; Warnick, L D; Mitchell, R M; Kaneene, J B; Ruegg, P L; Wells, S J; Fossler, C P; Halbert, L W; May, K
The objective of this study was to compare antimicrobial susceptibility of Salmonella isolated from conventional and organic dairy farms in the Midwest and Northeast United States. Environmental and fecal samples were collected from organic (n = 26) and conventional (n = 69) farms in Michigan, Minnesota, New York, and Wisconsin every 2 mo from August 2000 to October 2001. Salmonella isolates (n = 1,243) were tested using a broth microdilution method for susceptibility to amoxicillin-clavulanic acid, ampicillin, ceftiofur, ceftriaxone, cephalothin, chloramphenicol, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim-sulfamethoxazole. Herd-level logistic regression and logistic proportional hazards multivariable models were used to examine the association between farm management type and susceptibility to antimicrobial agents. For most antimicrobial agents tested, susceptibility of Salmonella isolates was similar on organic and conventional herds when controlling for herd size and state. Conventional farms were more likely to have at least one Salmonella isolate resistant to streptomycin using logistic regression (odds ratio = 7.5; 95% confidence interval = 1.7-5.4). Conventional farms were more likely to have Salmonella isolates with greater resistance to streptomycin (odds ratio = 5.4; 95% confidence interval = 1.5-19.0) and sulfamethoxazole (odds ratio = 4.2; 95% confidence interval = 1.2-14.1) using logistic proportional hazards models. Although not statistically significant, conventional farms tended to be more likely to have at least one Salmonella isolate resistant to 5 or more antimicrobial agents when compared with organic farms.
Leyer, G J; Johnson, E A
Salmonella typhimurium was adapted to acid by exposure to hydrochloric acid at pH 5.8 for one to two doublings. Acid-adapted cells had increased resistance to inactivation by organic acids commonly present in cheese, including lactic, propionic, and acetic acids. Recovery of cells during the treatment with organic acids was increased 1,000-fold by inclusion of 0.1% sodium pyruvate in the recovery medium. Acid-adapted S. typhimurium cells survived better than nonadapted cells during a milk fermentation by a lactic acid culture. Acid-adapted cells also showed enhanced survival over a period of two months in cheddar, Swiss, and mozzarella cheeses kept at 5 degrees C. Acid adaptation was found in Salmonella spp., including Salmonella enteritidis, Salmonella choleraesuis subsp. choleraesuis serotype heidelberg, and Salmonella choleraesuis subsp. choleraesuis serotype javiana, associated with food poisoning. These observations support the theory that acid adaptation is an important survival mechanism enabling Salmonella spp. to persist in fermented dairy products and possibly other acidic food products. PMID:1622286
Davies, R H; Wales, A D
Cereal ingredients for animal feedstuffs may become contaminated by Salmonella on their farms of origin. This is often concentrated in multiple foci, owing to contamination by rodents and other wildlife which may be missed by routine sampling, and may involve serovars of particular public health significance, such as Salmonella Typhimurium (STM). The study examined such contamination in domestically-produced cereal ingredients in the United Kingdom. Cereal-producing farms with associated cattle or pig enterprises (43) and feedmills (6) were investigated, following the isolation of STM from their premises (feedmills) or STM DT104 from their livestock (farms) by routine surveillance. Cereal samples from feedmills yielded two STM isolates from the same premises, of the same phage types as were isolated from wild bird faeces at ingredient intake and product loading areas. Farm investigations identified numerous Salmonella serovars, including STM, on grain harvesting and handling equipment, in grain storage areas, and in wildlife samples. Mice were removed from one pig farm and shed Salmonella Derby and Salmonella Bovismorbificans for 10 months afterwards. Grain stores more than one kilometre away from livestock areas were rarely found to be contaminated with STM. The principal issues with Salmonella contamination of cereals appeared to be the use of livestock areas as temporary grain stores on cattle farms, and access to stored grain by wildlife and domestic animals.
Stewart, Diana S; Reineke, Karl F; Tortorello, Mary L
The Assurance Gold Salmonella EIA, BAX for Screening/Salmonella, and GENE-TRAK Salmonella DLP rapid assays were compared with official cultural methods described in the Bacteriological Analytical Manual (BAM) for analysis of alfalfa sprouts and sprout irrigation water for the presence of Salmonella. The lower limits of detection of 4 serovars of Salmonella cells (S. tennessee, S. muenchen, S. mbandanka, and S. cubana) in pure culture were determined as approximately log10 2, 5, and 6 for the BAX, GENE-TRAK, and Gold EIA, respectively. Despite its low detection limit, the BAX did not perform as well as the other assays in analyzing contaminated sprouts and sprout irrigation water. For 4 different lots of sprouts and sprout irrigation water samples inoculated with the 4 serovars at low [1-2 colony forming units (CFU/g)] and high (68-180 CFU/g) levels, the BAX detected Salmonella in 58/64 (90.6%) of the samples, compared with 64/64 (100%) by the GENE-TRAK, Gold EIA, and BAM methods. Assay performance was also compared for analysis of naturally contaminated sprouts and sprout irrigation water with 3 lots of alfalfa sprouted seeds associated with different salmonellosis outbreaks. Positive assay results for the naturally contaminated samples were Gold EIA 41, GENE-TRAK 36, BAM 33, and BAX 13.
Jajere, Saleh Mohammed; Onyilokwu, Samson Amali; Adamu, Nuhu Bala; Atsanda, Naphtali Nayamanda; Saidu, Adamu Saleh; Adamu, Shuaibu Gidado; Mustapha, Fatima Bukar
The prevalence and antimicrobial sensitivity of Salmonella from dogs in Maiduguri Metropolis were determined using standard bacteriological methods to assess the risk of possible transmission of Salmonella infection from dogs to humans. Of 119 samples, Salmonella was isolated from 52 (43.7%). Males had higher prevalence of 50.0% compared with 34.7% in females (P < 0.05). Dogs older than 24 months had higher prevalence of 61.0% and the lowest was seen in dogs aged 13–24 months (P < 0.05). The prevalence of 31.8%, 41.2%, and 58.8% was observed in dogs aged 3–6, 10–12, and 7–9 months, respectively. High prevalence of 49.5% was observed in Mongrels, while Terrier and Alsatian breeds had 30.0% and 8.3%, respectively. Salmonella isolates from Alsatian and Terrier breeds showed about 100% susceptibility to all the tested antimicrobials. Higher percentage of the Salmonella isolates from Mongrels also showed susceptibility to ciprofloxacin (89.7%), amoxicillin (87.6%), vancomycin (86.6%), and chloramphenicol (84.5%). However about 50% of these isolates showed resistance to ofloxacin. The carrier status of Salmonella is high among dogs especially Mongrels. Therefore good environmental hygiene, discouraging straying coupled with feeding of dogs with properly cooked and uncontaminated feeds was recommended to mitigate risk of human salmonellosis. PMID:25404944
Arnott, M L; Gutteridge, C S; Pugh, S J; Griffiths, J L
A modified lysine decarboxylase broth has been developed which could be used with a Bactometer M123 to differentiate salmonellas from other bacteria by the characteristics of the conductance detection curve. The medium was used in combination with a selenite cystine trimethylamine oxide dulcitol medium to screen 50 strains of salmonellas and 42 strains of other organisms to establish detection curve magnitude and rate values which could be used to identify curves specific to salmonellas. The combination of media detected all salmonellas tested except Salmonella pullorum. The two media were used to screen 100 inoculated product samples with the Bactometer instrument, in parallel with traditional plating procedures, and using various combinations of pre-enrichment and selective enrichment incubation periods. After 24 h pre-enrichment, the Bactometer system detected more positive samples than the conventional plating procedures after pre-enrichment and selective enrichment. It is considered that these media used in parallel in the Bactometer after conventional pre-enrichment could provide a 48 h screening procedure for salmonellas with a sensitivity comparable to present plating procedures.
Waterman, S H; Juarez, G; Carr, S J; Kilman, L
In 1987 two Los Angeles County (California) hospitals reported four Latino patients with serious Salmonella arizona (Salmonella subgroup 3) infections who gave a medical history of taking rattlesnake capsules prior to illness. Capsules supplied by the patients or household members grew Salmonella arizona. We reviewed surveillance data for this Salmonella species and conducted a case-control study to determine the magnitude of this public health problem. Eighteen (82 percent) of the 22 Latino cases in 1986 and 1987 who were questioned reported ingesting snake capsules compared to two (8 percent) of 24 matched Latino controls with non-subgroup 3 salmonellosis or shigellosis (matched pair odds ratio = 18.0, CI = 4.2, 76.3). An average of 18 cases per year of Salmonella arizona were reported in the county between 1980 and 1987. In this investigation the majority of S. arizona cases reporting snake capsule ingestion had underlying illnesses such as acquired immunodeficiency syndrome (AIDS), diabetes, arthritis, cancer. The capsules were obtained primarily from Tijuana, Mexico and from Los Angeles, California pharmacies in Latino neighborhoods. Despite publicity and attempts to remove the capsules from sale in California, Salmonella arizona cases associated with snake-capsule ingestion continue to occur. PMID:2305906
Richter, J; Becker, H; Märtlbauer, E
The Oxoid SPRINT Salmonella test was compared with the ISO method (ISO 6579: 1993) for the detection of Salmonella in milk and dairy products. Samples were artificially contaminated, in some cases with sublethally injured salmonellas. Experiments with raw milk, soft cheese made from heat-treated milk (mould-ripened and with smear) and soft cheese with smear made from raw milk showed no significant differences between the SPRINT and ISO methods. With dried milk products and mould-ripened soft cheese made from raw milk the reference method gave significantly more positive results. The addition of ferrioxamine E to pre-enrichment (ISO) or pre-enrichment/enrichment broth (SPRINT test) did not improve Salmonella detection.
Manguerra, Mark C.; Yancovitz, Stanley
Human infections with Salmonella Blockley are uncommon, and cases described in the literature are usually gastrointestinal in origin. We report a case of an implantable cardioverter-defibrillator (ICD) infection in a 76-year-old Chinese man who presented with pain, redness, and warmth from the ICD pocket site, which later developed a sinus draining purulent material. S. Blockley was isolated from the wound and the patient underwent device removal and treatment with intravenous ceftriaxone. S. Blockley was cultured from the generator and the leads. The patient did not develop fever or bacteremia. This is, to the best of our knowledge, the first reported case of S. Blockley cardiac device infection. PMID:26793438
Diard, Médéric; Bakkeren, Erik; Cornuault, Jeffrey K; Moor, Kathrin; Hausmann, Annika; Sellin, Mikael E; Loverdo, Claude; Aertsen, Abram; Ackermann, Martin; De Paepe, Marianne; Slack, Emma; Hardt, Wolf-Dietrich
Bacteriophage transfer (lysogenic conversion) promotes bacterial virulence evolution. There is limited understanding of the factors that determine lysogenic conversion dynamics within infected hosts. A murine Salmonella Typhimurium (STm) diarrhea model was used to study the transfer of SopEΦ, a prophage from STm SL1344, to STm ATCC14028S. Gut inflammation and enteric disease triggered >55% lysogenic conversion of ATCC14028S within 3 days. Without inflammation, SopEΦ transfer was reduced by up to 10(5)-fold. This was because inflammation (e.g., reactive oxygen species, reactive nitrogen species, hypochlorite) triggers the bacterial SOS response, boosts expression of the phage antirepressor Tum, and thereby promotes free phage production and subsequent transfer. Mucosal vaccination prevented a dense intestinal STm population from inducing inflammation and consequently abolished SopEΦ transfer. Vaccination may be a general strategy for blocking pathogen evolution that requires disease-driven transfer of temperate bacteriophages.
Kagawa, H; Owaribe, K; Asakura, S; Takahashi, N
From acid-disintegrated flagellar hooks of Salmonella SJ25 an immunochemically pure preparation of hook protein was obtained by column chromatography. The molecular weight of the protein determined by sodium dodecyl sulfate-gel electrophoresis was 43,000, whereas that of SJ25 flagellin was 56,000. The amino-terminal residue of the hook protein was determined to be seryl. The amino acid composition of the protein was determined, the results being very similar to that for an Escheria coli hook protein reported by Silverman and Simon (1972). Within a wavelength range of 200 to 250 nm, our purified preparation of hook protein gave a circular dichroism spectrum with unusually small amplitudes, suggesting that the alpha-helix content of the protein was very low.
Shukla, Yogeshwer; Taneja, Pankaj; Arora, Annu; Sinha, Neeraj
Mancozeb, a dithiocarbamate fungicide, was examined for its possible mutagenic activity using Salmonella typhimurium tester strains TA97a, TA98, TA100, and TA102. We found that Mancozeb exhibited toxic effects at the dose of 40 microg/plate and higher with all tester strains. Mancozeb showed dose-dependent increases in the number of revertants with and without metabolic activation when it was dissolved in DMSO or acetone with strain TA97a; however, the number of revertants at the highest dose was less than two-fold compared to control values. We postulate that the true mutagenic potential of Mancozeb may be masked by its toxic effect to the tester strain used.
Kourany, M; Bowdre, L; Herrer, A
Enteric bacteria pathogenic to man were sought in a total of 974 forest mammals collected from a variety of sites in rural and jungle areas of Panamá. The highest incidence of infection among the mammals was observed during the Panamanian dry season, which normally extends from January through April. A minimum of 10 Salmonella serotypes including, three of the Arizona group and Ewardsiella tarda, was isolated. Opossums of the genera Philander, 11 of 54 (20.1%), and Didelphis, 12 of 102 (11.8%) demonstrated high infection rates. One sloth of the genus Choloepus and specimens of two genera of rodents also were infected to varying degrees: 1(11.1%) of 9 Choloepus, 8 (1.1%) of 704 Proechimys and 1 (16.7%) of 6 Diplomys.
Dr. Cheryl Nickerson of Tulane University is studying the effects of simulated low-g on a well-known pathogen, Salmonella typhimurium, a bacterium that causes two to four million cases of gastrointestinal illness in the United States each year. While most healthy people recover readily, S. typhimurium can kill people with weakened immune systems. Thus, a simple case of food poisoning could disrupt a space mission. Using the NASA rotating-wall bioreactor, Nickerson cultured S. typhimurium in modeled microgravity. Mice infected with the bacterium died an average of three days faster than the control mice, indicating that S. typhimurium's virulence was enhanced by the bioreactor. Earlier research showed that 3 percent of the genes were altered by exposure to the bioreactor. Nickerson's work earned her a 2001 Presidential Early Career Award for Scientists and Engineers.
Bearson, Shawn M D; Allen, Heather K; Bearson, Bradley L; Looft, Torey; Brunelle, Brian W; Kich, Jalusa D; Tuggle, Christopher K; Bayles, Darrell O; Alt, David; Levine, Uri Y; Stanton, Thaddeus B
Controlling Salmonella in the food chain is complicated by the ability of Salmonella to colonize livestock without causing clinical symptoms/disease. Salmonella-carrier animals are a significant reservoir for contamination of naïve animals, the environment, and our food supply. Salmonella carriage and shedding in pigs varies greatly both experimentally and on-farm. To investigate the dynamics between the porcine intestinal microbiota and Salmonella shedding, we temporally profiled the microbiota of pigs retrospectively classified as low and high Salmonella-shedders. Fifty-four piglets were collectively housed, fed and challenged with 10(9)Salmonella enterica serovar Typhimurium. Bacterial quantitation of Salmonella in swine feces was determined, and total fecal DNA was isolated for 16S rRNA gene sequencing from groups of high-shedder, low-shedder, and non-inoculated pigs (n=5/group; 15 pigs total). Analyses of bacterial community structures revealed significant differences between the microbiota of high-shedder and low-shedder pigs before inoculation and at 2 and 7 days post-inoculation (d.p.i.); microbiota differences were not detected between low-shedder and non-inoculated pigs. Because the microbiota composition prior to Salmonella challenge may influence future shedding status, the "will-be" high and low shedder phylotypes were compared, revealing higher abundance of the Ruminococcaceae family in the "will-be" low shedders. At 2d.p.i., a significant difference in evenness for the high shedder microbiota compared to the other two groups was driven by decreases in Prevotella abundance and increases in various genera (e.g. Catenibacterium, Xylanibacter). By 21 d.p.i., the microbial communities of high-shedder and low-shedder pigs were no longer significantly different from one another, but were both significantly different from non-inoculated pigs, suggesting a similar Salmonella-induced alteration in maturation of the swine intestinal microbiota regardless of
Grilli, E; Tugnoli, B; Formigoni, A; Massi, P; Fantinati, P; Tosi, G; Piva, A
The reduction of Salmonella prevalence in broilers is a priority in European Union agricultural policies because treatment with antibiotics is forbidden by Regulation (EC) 2160/2003. Two trials were conducted to evaluate the efficacy of a microencapsulated blend of sorbic acid and nature-identical compounds (i.e., chemically synthesized botanicals; SAB) on the reduction of the cecal prevalence and contents of Salmonella enterica serovars Hadar and Enteritidis in experimentally infected chickens. In the first trial, 125 one-day-old Lohmann specific-pathogen-free chickens were assigned to one of the following treatments: negative control (not challenged and not treated), positive control (challenged and not treated), SAB0.3, SAB1, or SAB5 (challenged and treated with the microencapsulated blend included in the feed at 0.03, 0.1, or 0.5%, respectively). At 30 d of age, birds were infected with 10(6) cfu of Salmonella Hadar, and after 5, 10, or 20 d postinfection, 5, 10, and 10 birds per treatment, respectively, were killed and the cecal contents and liver and spleen samples were analyzed for Salmonella Hadar. In the second trial, 100 one-day-old Ross 708 chickens were assigned to 1 of 5 treatments: control (not treated), SAB0.3, SAB1, SAB2, or SAB5 (treated with the blend included in the feed at 0.03, 0.1, 0.2, or 0.5%, respectively). At 7 d of age, the birds were challenged with 10(5) cfu of Salmonella Enteritidis, and after 7, 14, or 24 d after challenge, 5, 5, and 10 birds per treatment, respectively, were killed and cecal contents were analyzed for Salmonella Enteritidis. Results showed that in the early stage of infection Salmonella prevalence was high in both studies, whereas at the end of the observation periods, the blends at 0.03, 0.1, and 0.5 in the challenge with Salmonella Hadar and at 0.2 and 0.5% in the challenge with Salmonella Enteritidis significantly reduced (by 2 log(10) cfu) the cecal content of Salmonella. This study showed that intestinal
Pasmans, Frank; Martel, An; Boyen, Filip; Vandekerchove, Dominique; Wybo, Ingrid; Immerseel, Filip Van; Heyndrickx, Marc; Collard, Jean Marc; Ducatelle, Richard; Haesebrouck, Freddy
Reptile-associated salmonellosis in humans is an increasing public health issue. This study aimed at characterizing Salmonella isolates from captive lizards and to compare them to human isolates. Salmonella was isolated from 25 of 33 cloacal and 47 of 79 faecal samples from captive lizards (75.8 and 59.5%, respectively). The strains belonged to 44 serotypes of subspecies I (27 serotypes), II (9), IIIb (3) and IV (5). Two strains, one of serotype Enteritidis and one of serotype Amsterdam, were resistant to nitrofurantoin. Invasion assays in Caco-2 cells were performed with 40 saurian isolates of subspecies I, 15 isolates of subspecies II, 4 strains of subspecies IIIb, 6 subspecies IV isolates and 17 human isolates of corresponding serotypes of subspecies I. Saurian isolates belonging to subspecies I invaded the Caco-2 cells to a higher extent than those from the other subspecies. The human isolates invaded the Caco-2 cells to a lesser degree compared to their saurian counterparts. In the same strains, the presence of virulence genes agfA, shdA, spvR, pefA and sopE was determined using PCR. Whereas agfA was detected in all strains, pefA was only detected in one saurian and in the human serotype Enteritidis strains. The spvR gene was detected in the same serotype Enteritidis strains and in 33% of the subspecies IV strains. The shdA gene was present in all the human isolates and in 86% of subspecies I saurian isolates. SopE was found in 17% of the human isolates, in 24% of the saurian subspecies I strains and in all of the subspecies IV strains.
Desai, Prerak T.; Porwollik, Steffen; Long, Fred; Cheng, Pui; Wollam, Aye; Clifton, Sandra W.; Weinstock, George M.; McClelland, Michael
ABSTRACT Six subspecies are currently recognized in Salmonella enterica. Subspecies I (subspecies enterica) is responsible for nearly all infections in humans and warm-blooded animals, while five other subspecies are isolated principally from cold-blooded animals. We sequenced 21 phylogenetically diverse strains, including two representatives from each of the previously unsequenced five subspecies and 11 diverse new strains from S. enterica subspecies enterica, to put this species into an evolutionary perspective. The phylogeny of the subspecies was partly obscured by abundant recombination events between lineages and a relatively short period of time within which subspeciation took place. Nevertheless, a variety of different tree-building methods gave congruent evolutionary tree topologies for subspeciation. A total of 285 gene families were identified that were recruited into subspecies enterica, and most of these are of unknown function. At least 2,807 gene families were identified in one or more of the other subspecies that are not found in subspecies I or Salmonella bongori. Among these gene families were 13 new candidate effectors and 7 new candidate fimbrial clusters. A third complete type III secretion system not present in subspecies enterica (I) isolates was found in both strains of subspecies salamae (II). Some gene families had complex taxonomies, such as the type VI secretion systems, which were recruited from four different lineages in five of six subspecies. Analysis of nonsynonymous-to-synonymous substitution rates indicated that the more-recently acquired regions in S. enterica are undergoing faster fixation rates than the rest of the genome. Recently acquired AT-rich regions, which often encode virulence functions, are under ongoing selection to maintain their high AT content. PMID:23462113
Wu, Daichao; Teng, Da; Wang, Xiumin; Dai, Changsong; Wang, Jianhua
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.
Rasschaert, G; Michiels, J; Tagliabue, M; Missotten, J; De Smet, S; Heyndrickx, M
This study builds on the results of a previous study in which six commercial feed products based on organic acids were evaluated with respect to Salmonella contamination of piglets in an artificially challenged seeder model. In the present study, the efficacy of three of these commercial products was assessed for Salmonella reduction in fattening pigs on one closed farm with a natural high Salmonella prevalence. In each of four fattening compartments, one of the following feed treatments was evaluated during two consecutive fattening rounds: (i) butyric acid (active ingredients at 1.3 kg/ton of feed; supplement A1), (ii) a combination of short-chain organic acids (mixture of free acids and salts) and natural extracts (2.92 kg/ton; supplement A4), (iii) a 1:1 blend of two commercial products consisting of medium-chain fatty acids, lactic acid, and oregano oil (3.71 kg/ton; supplement A5+A6), and (iv) a control feed. On the farm, the Salmonella status of the fattening pigs was evaluated by taking fecal samples twice during the fattening period. At the slaughterhouse, samples were collected from the cecal contents and the ileocecal lymph nodes. Salmonella isolates were serotyped and characterized by pulsed-field gel electrophoresis. This farm had a particularly high number of pigs shedding Salmonella with a wide variety of sero- and pulsotypes. Only the feed blend based on the medium-chain fatty acids was able to significantly reduce Salmonella prevalence both on the farm and at the slaughterhouse. With this combined supplement, the Salmonella reduction in the feces at slaughter age, in cecal contents at slaughter, and the lymph nodes was 50, 36, and 67%, respectively, compared with the control animals. This promising finding calls for further investigation including cost-efficiency of this combined feed product and its effect on the animals.
Buzinhani, Melissa; Tremblay, Renaud; Martinez, Gabriela; Giuffre, Michael; Hammack, Thomas; Fernandez, Maria Cristina; Ziemer, Wayne
The FoodChek™ - Salmonella assay is an immunomagnetic lateral flow assay for the rapid detection (shorter than 24 h) of the most frequently isolated Salmonella (groups B-E) in eggs, egg-derivative products, and environmental surfaces. The FoodChek - Salmonella assay correctly identified 99.6% (239/240) of the samples tested in the matrix studied, and the statistical analysis of the method comparison study results demonstrated that it performs as well as U.S. culture-based reference methods. Ninety-nine percent of the 103 Salmonella strains tested belonging to serogroups B-E were detected during the inclusivity study. Concerning the exclusivity, 31 nontarget strains were tested. No cross-reactivity was observed in FoodChek - Salmonella assay enrichment conditions. In addition, the assay shows strong robustness, good stability, and consistency among lots. The present study proves that the assay is an effective tool for the rapid detection of Salmonella spp. in whole liquid eggs, liquid egg white (liquid egg albumen), shell eggs, dried whole eggs, dried egg yolks, and environmental surfaces as stainless steel, plastic, rubber, ceramic tiles, and sealed concrete.
Comparison of a PCR serotyping assay, Check&Trace assay for Salmonella, and Luminex Salmonella serotyping assay for the characterization of Salmonella enterica identified from fresh and naturally contaminated cilantro.
Jean-Gilles Beaubrun, J; Ewing, L; Jarvis, K; Dudley, K; Grim, C; Gopinath, G; Flamer, M-L; Auguste, W; Jayaram, A; Elmore, J; Lamont, M; McGrath, T; Hanes, D E
Salmonella enterica isolated from fresh cilantro samples collected through the USDA/AMS Microbiological Data Program (MDP) were used to compare a PCR serotyping assay against the Check&Trace assay and the Luminex (BioPlex) Salmonella serotyping assay. The study was conducted to evaluate the effectiveness of the three methods for serotyping Salmonella from both enrichment broth cultures and pure Salmonella cultures. In this investigation, Salmonella spp. serotyping was conducted using 24 h enrichment broth cultures and pure Salmonella cultures from cilantro samples, with the PCR serotyping assay. Conversely, the Check&Trace and Luminex for Salmonella assays required pure cultures for Salmonella serotyping. The cilantro samples contained S. enterica serovar Montevideo, Newport, Saintpaul, and Tennessee, identified by the PCR serotyping assay and Check&Trace for Salmonella, but the Luminex assay only identified two of the four serotypes of the cilantro samples. The anticipated impact from this study is that the PCR serotyping assay provides a time- and cost-effective means for screening, identifying and serotyping Salmonella using DNA extracted from 24 h enrichment cilantro samples.
Finishing pigs infected with Salmonella pose significant food safety risks by carrying the pathogen into abattoirs. This study was conducted to determine the dynamic of Salmonella infection in finishing pigs, and associated immunological, physiological, and behavioral alterations, by longitudinally ...
Current federal regulations required monitoring for fecal coliforms or Salmonella in biosolids destined for land application. Methods used for analysis of fecal coliforms and Salmonella have been developed and are currently in use for quantification of these organisms. Recently c...
Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment is critical for invasive salmonellosis. Primary antimicrobial treatment options include fluoroquinolones or extende...
Verbrugghe, Elin; Van Parys, Alexander; Leyman, Bregje; Boyen, Filip; Haesebrouck, Freddy; Pasmans, Frank
Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) contamination of pork, is one of the major sources of human salmonellosis. The bacterium is able to persist and hide in asymptomatic carrier animals, generating a reservoir for Salmonella transmission to other animals and humans. Mechanisms involved in Salmonella persistence in pigs remain poorly understood. In the present study, we demonstrate that the Salmonella htpG gene, encoding a homologue of the eukaryotic heat shock protein 90, contributes to Salmonella Typhimurium persistence in intestine-associated tissues of pigs, but not in the tonsils. HtpG does not seem to play an important role during the acute phase of infection. The contribution to persistence was shown to be associated with htpG-dependent Salmonella invasion and survival in porcine enterocytes and macrophages. These results reveal the role of HtpG as a virulence factor contributing to Salmonella persistence in pigs.
Ali, Mohamed M.; Newsom, David L.; González, Juan F.; Sabag-Daigle, Anice; Stahl, Christopher; Steidley, Brandi; Dubena, Judith; Dyszel, Jessica L.; Smith, Jenee N.; Dieye, Yakhya; Arsenescu, Razvan; Boyaka, Prosper N.; Krakowka, Steven; Romeo, Tony; Behrman, Edward J.; White, Peter; Ahmer, Brian M. M.
Salmonella enterica serovar Typhimurium (Salmonella) is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn), which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10−/− mice). The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1− SPI2− or ttrA mutants, respectively). The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies. PMID:24967579
Gruenewald, R; Henderson, R W; Yappow, S
When grown on Rambach Propylene Glycol Containing Agar (Rambach agar), 216 of 230 (93.9%) Salmonella organisms isolated from patients and 54 of 62 (87.1%) Salmonella stock cultures produced a crimson-colored growth. Of the 14 clinical Salmonella isolates which displayed colors other than crimson, 8 were Salmonella typhi, 2 were Salmonella paratyphi A, and 4 belonged to other commonly isolated serotypes. All eight Salmonella stock cultures which failed to produce a crimson color belonged to rarely isolated serotypes. In contrast, of 83 non-Salmonella stock cultures distributed among 29 bacterial species, none produced a crimson color. These results suggest that while Rambach agar cannot preidentify S. typhi and S. paratyphi A, the medium can be used for the presumptive identification and can assist in the definitive identification of the overwhelming majority of Salmonella isolates.
Liss, Viktoria; Swart, A Leoni; Kehl, Alexander; Hermanns, Natascha; Zhang, Yuying; Chikkaballi, Deepak; Böhles, Nathalie; Deiwick, Jörg; Hensel, Michael
Salmonella enterica is a facultative intracellular pathogen that survives and proliferates in the Salmonella-containing vacuole (SCV), yet how these vacuolar bacteria acquire nutrition remains to be determined. Intracellular Salmonella convert the host endosomal system into an extensive network of interconnected tubular vesicles, of which Salmonella-induced filaments (SIFs) are the most prominent. We found that membranes and lumen of SIFs and SCVs form a continuum, giving vacuolar Salmonella access to various types of endocytosed material. Membrane proteins and luminal content rapidly diffuse between SIFs and SCVs. Salmonella in SCVs without connection to SIFs have reduced access to endocytosed components. On a single-cell level, Salmonella within the SCV-SIF continuum were found to exhibit higher metabolic activity than vacuolar bacteria lacking SIFs. Our data demonstrate that formation of the SCV-SIF continuum allows Salmonella to bypass nutritional restriction in the intracellular environment by acquiring nutrients from the host cell endosomal system.
Breeder flocks and commercial hatcheries represent an early contamination point for Salmonella entry into commercial integrated poultry operations. Utilizing effective antimicrobial treatments for hatching eggs is a critical part of reducing the incidence of Salmonella colonized chicks on the farm....
Current federal regulations require monitoring for fecal coliforms or Salmonella in biosolids destined for land application. Methods used for analysis of fecal coliforms and Salmonella were reviewed and a standard protocol was developed. The protocols were then evaluated by testi...
Sha, Qiong; Vattem, Dhiraj A; Forstner, Michael R J; Hahn, Dittmar
Members of the bacterial genus Salmonella are recognized worldwide as major zoonotic pathogens often found to persist in non-enteric environments including heterogeneous aquatic biofilms. In this study, Salmonella isolates that had been detected repeatedly over time in aquatic biofilms at different sites in Spring Lake, San Marcos, Texas, were identified as serovars Give, Thompson, Newport and -:z10:z39. Pathogenicity results from feeding studies with the nematode Caenorhabditis elegans as host confirmed that these strains were pathogenic, with Salmonella-fed C. elegans dying faster (mean survival time between 3 and 4 days) than controls, i.e., Escherichia coli-fed C. elegans (mean survival time of 9.5 days). Cells of these isolates inoculated into water at a density of up to 10(6) ml(-1) water declined numerically by 3 orders of magnitude within 2 days, reaching the detection limit of our quantitative polymerase chain reaction (qPCR)-based quantification technique (i.e., 10(3) cells ml(-1)). Similar patterns were obtained for cells in heterogeneous aquatic biofilms developed on tiles and originally free of Salmonella that were kept in the inoculated water. Cell numbers increased during the first days to more than 10(7) cells cm(-2), and then declined over time. Ten-fold higher cell numbers of Salmonella inoculated into water or into biofilm resulted in similar patterns of population dynamics, though cells in biofilms remained detectable with numbers around 10(4) cells cm(-2) after 4 weeks. Independent of detectability by qPCR, samples of all treatments harbored viable salmonellae that resembled the inoculated isolates after 4 weeks of incubation. These results demonstrate that pathogenic salmonellae were isolated from heterogeneous aquatic biofilms and that they could persist and stay viable in such biofilms in high numbers for some time.
Zheng, Jie; Allard, Sarah; Reynolds, Sara; Millner, Patricia; Arce, Gabriela; Blodgett, Robert J; Brown, Eric W
The consumption of fresh tomatoes has been linked to numerous food-borne outbreaks involving various serovars of Salmonella enterica. Recent advances in our understanding of plant-microbe interactions have shown that human enteric pathogenic bacteria, including S. enterica, are adapted to survive in the plant environment. In this study, tomato plants (Solanum lycopersicum cv. Micro-Tom) grown in sandy loam soil from Virginia's eastern shore (VES) were inoculated with S. enterica serovars to evaluate plausible internalization routes and to determine if there is any niche fitness for certain serovars. Both infested soil and contaminated blossoms can lead to low internal levels of fruit contamination with Salmonella. Salmonella serovars demonstrated a great ability to survive in environments under tomato cultivation, not only in soil but also on different parts of the tomato plant. Of the five serovars investigated, Salmonella enterica serovars Newport and Javiana were dominant in sandy loam soil, while Salmonella enterica serovars Montevideo and Newport were more prevalent on leaves and blossoms. It was also observed that Salmonella enterica serovar Typhimurium had a poor rate of survival in all the plant parts examined here, suggesting that postharvest contamination routes are more likely in S. Typhimurium contamination of tomato fruit. Conversely, S. Newport was the most prevalent serovar recovered in both the tomato rhizosphere and phyllosphere. Plants that were recently transplanted (within 3 days) had an increase in observable internalized bacteria, suggesting that plants were more susceptible to internalization right after transplant. These findings suggest that the particular Salmonella serovar and the growth stage of the plant were important factors for internalization through the root system.
Brandl, Maria T; Mandrell, Robert E
The epiphytic fitness of Salmonella enterica was assessed on cilantro plants by using a strain of S. enterica serovar Thompson that was linked to an outbreak resulting from cilantro. Salmonella serovar Thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (CLSM) at high densities on the veins and in natural lesions. The population sizes of two common colonizers of plant surfaces, Pantoea agglomerans and Pseudomonas chlororaphis, were 10-fold higher than that of the human pathogen on cilantro incubated at 22 degrees C. However, Salmonella serovar Thompson achieved significantly higher population levels and accounted for a higher proportion of the total culturable bacterial flora on cilantro leaves when the plants were incubated at warm temperatures, such as 30 degrees C, after inoculation, indicating that the higher growth rates exhibited by Salmonella serovar Thompson at warm temperatures may increase the competitiveness of this organism in the phyllosphere. The tolerance of Salmonella serovar Thompson to dry conditions on plants at 60% relative humidity was at least equal to that of P. agglomerans and P. chlororaphis. Moreover, after exposure to low humidity on cilantro, Salmonella serovar Thompson recovered under high humidity to achieve its maximum population size in the cilantro phyllosphere. Visualization by CLSM of green fluorescent protein-tagged Salmonella serovar Thompson and dsRed-tagged P. agglomerans inoculated onto cilantro revealed that the human pathogen and the bacterial epiphyte formed large heterogeneous aggregates on the leaf surface. Our studies support the hypothesis that preharvest contamination of crops by S. enterica plays a role in outbreaks linked to fresh fruits and vegetables.
Heyse, Serena; Hanna, Leigh Farris; Woolston, Joelle; Sulakvelidze, Alexander; Charbonneau, Duane
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.
Crump, John A; Heyderman, Robert S
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.
Fashae, Kayode; Hendriksen, Rene S
Animals including food animals play a significant role in the epidemiology of Salmonella enterica. The control requires identification of sources and institution of targeted interventions. This study investigates the diversity of S. enterica serovars, antimicrobial susceptibility, and occurrence of plasmid-mediated quinolone resistance (PMQR) genes in pigs in Ibadan, Nigeria. Pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the Salmonella isolates were serotyped and their antimicrobial susceptibility was determined. PMQR genes were screened by polymerase chain reaction. The 229 Salmonella isolates were made of 50 serovars predominated by rare serovars Salmonella Give (n = 36; 15.7 %), Salmonella Brancaster (n = 17; 7.4 %), Salmonella Colindale (n = 15; 6.6 %), Salmonella Elisaberthville (n = 13; 5.7 %), Salmonella Hillingdon (n = 13; 5.7 %), and Salmonella Kingston (n = 13; 5.7 %). The most widely distributed serovars among the farms were Salmonella Give (six farms) and Salmonella Elisaberthville (six farms). Resistance to chloramphenicol, sulfonamides, nalidixic acid, streptomycin, and tetracycline ranged from 11.6 % (n = 26) to 22.8 % (n = 51). Resistance ciprofloxacin and gentamicin was low (n = 2; 0.9 %). Multiply resistant isolates included Salmonella Kentucky, the most resistant serovar. qnrB19 was found in two isolates of Salmonella Corvallis and one isolate of Salmonella Larochelle, respectively, while qnrS1 was found in two isolates of Salmonella Derby. Other PMQR genes were not detected. Pigs constitute an important source of diverse Salmonella serovars in Ibadan. The isolates were more resistant to old antimicrobials with some multiple resistant. Control measures and regulation of antimicrobials are warranted.
Aschfalk, Ansgar; Hundertmark, Kris J; Bendiksen, Heidi R; Arnemo, Jon M; Denzin, Nicolai
An indirect ELISA was developed as a tool for surveillance of antibodies against Salmonella sp. in free-ranging moose (Alces alces) in Norway. Serum samples from 303 clinically healthy moose sampled between 1993-2000 were examined. Anti-Salmonella antibodies were detected in samples from 6 individuals (1.98%). This is the first evidence of Salmonella-seropositive free-ranging moose. Possible sources and transmission routes of Salmonella comprising environment, wildlife and man are discussed.
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...
Kumar, S.; Saxena, S. P.; Gupta, B. K.
To find out the salmonella carrier rate, 5980 samples comprising faeces, mesenteric lymph nodes, liver and spleen were collected from 812 sheep and 683 goats slaughtered for food. In all 72 salmonella strains from 51 animals (25 sheep and 26 goats) were isolated. These represented 22 salmonella serotypes. The public health significance of these findings is discussed. PMID:4511949
On-farm reduction of Salmonella prevalence in pigs requires the identification of risk factors to direct interventions. 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...
Salmonella is the most commonly identified foodborne pathogen in produce, meat and poultry. Cattle are known reservoirs of Salmonella and the pathogen excreted in feces end up in manure flush lagoons. Salmonella enterica survival was monitored in wastewater from on-site holding lagoons equipped with...
Introduction Some bacteria in the cecal microflora of broilers can inhibit colonization of chicks by Salmonella. Beneficial cecal bacteria may reduce Salmonella colonization by competing for nutrients and attachment sites or by producing metabolites that inhibit Salmonella growth. The purpose of th...
Salmonella is a major cause of foodborne illness and can cause clinical disease in animals. Understanding the on-farm ecology of Salmonella will be helpful in decreasing the risk of foodborne transmission. An objective of this study was to determine the prevalence of Salmonella among fecal samples c...
... 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...
... the bacteriological examination of salmonella. 147.11 Section 147.11 Animals and Animal Products... procedure recommended for the bacteriological examination of salmonella. (a) For egg- and meat-type chickens... 25 birds, and birds from Salmonella enteritidis (SE) positive environments should be cultured...
... 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...
... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Testing methodology for Salmonella Enteritidis (SE....8 Testing methodology for Salmonella Enteritidis (SE). (a) Testing of environmental samples for SE... Sampling and Detection of Salmonella in Poultry Houses,” April 2008, or an equivalent method in...
... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Testing methodology for Salmonella Enteritidis (SE....8 Testing methodology for Salmonella Enteritidis (SE). (a) Testing of environmental samples for SE... Sampling and Detection of Salmonella in Poultry Houses,” April 2008, or an equivalent method in...
... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Testing methodology for Salmonella Enteritidis (SE....8 Testing methodology for Salmonella Enteritidis (SE). (a) Testing of environmental samples for SE... Sampling and Detection of Salmonella in Poultry Houses,” April 2008, or an equivalent method in...
... 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...
Pigs are often asymptomatically colonized with the human foodborne pathogen Salmonella and can exhibit notable variation in severity and duration of Salmonella fecal shedding. Multiple factors impact the dynamics of Salmonella in swine, including features of the microorganism, responses from the pi...
Non-typhoidal Salmonella, a leading cause of U.S. foodborne disease and food-related deaths, often asymptomatically colonizes food-producing animals. In fact, >50% of U.S. swine production facilities test positive for Salmonella. The multidrug-resistant (MDR) Salmonella Typhimurium DT104 NCTC13348 c...
Salmonella colonization of food animals is a concern for animal health, food safety and public health. Key objectives of pre-harvest food safety programs are to detect asymptomatic Salmonella carriage in food animals, reduce colonization, and prevent transmission of Salmonella to other animals and ...
... HUMAN SERVICES Food and Drug Administration Small Entity Compliance Guide: Prevention of Salmonella... availability of a guidance entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production... producers to implement measures to prevent Salmonella Enteritidis (SE) from contaminating eggs on the...
... 21 Food and Drugs 2 2011-04-01 2011-04-01 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...
... HUMAN SERVICES Food and Drug Administration Draft Compliance Policy Guide Sec. 690.800 Salmonella in... entitled ``Compliance Policy Guide Sec. 690.800 Salmonella in Animal Feed'' (the draft CPG). The draft CPG..., contaminated with Salmonella and also on regulatory policy relating to animal feed or feed...
... Answers Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production... Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation.'' The guidance contains... prevent Salmonella Enteritidis (SE) from contaminating eggs on the farm and from further growth...
... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Testing methodology for Salmonella Enteritidis (SE....8 Testing methodology for Salmonella Enteritidis (SE). (a) Testing of environmental samples for SE... Sampling and Detection of Salmonella in Poultry Houses,” April 2008, or an equivalent method in...
... 21 Food and Drugs 2 2010-04-01 2010-04-01 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...
... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Testing methodology for Salmonella Enteritidis (SE....8 Testing methodology for Salmonella Enteritidis (SE). (a) Testing of environmental samples for SE... Sampling and Detection of Salmonella in Poultry Houses,” April 2008, or an equivalent method in...
... HUMAN SERVICES Food and Drug Administration Compliance Policy Guide Sec. 690.800 Salmonella in Food for... ``Compliance Policy Guide Sec. 690.800 Salmonella in Food for Animals'' (the CPG). The CPG provides guidance to FDA staff on Salmonella-contaminated food for animals. DATES: Submit either electronic or...
... HUMAN SERVICES Food and Drug Administration Draft Compliance Policy Guide Sec. 690.800 Salmonella in... against animal feed or feed ingredients that are adulterated due to the presence of Salmonella. The Agency... adulterated due to the presence of Salmonella. The Agency has received a request for a 60-day extension of...
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...
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
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
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...
Tomato stem scars are a likely contamination point for Salmonella, although they are recalcitrant to decontamination. Investigating stem scar sanitation may represent a worst-case-scenario model for inactivating Salmonella from externally-contaminated tomatoes. A composite of Salmonella Saintpau...
Morales-Barrera, Eduardo; Calhoun, Nicole; Lobato-Tapia, Jose L; Lucca, Vivian; Prado-Rebolledo, Omar; Hernandez-Velasco, Xochitl; Merino-Guzman, Ruben; Petrone-García, Victor M; Latorre, Juan D; Mahaffey, Brittany D; Teague, Kyle D; Graham, Lucas E; Wolfenden, Amanda D; Baxter, Mikayla F A; Hargis, Billy M; Tellez, Guillermo
The objectives of the present study were to evaluate the risks involved in the use of Enrofloxacin for Salmonella Enteritidis (SE) or Salmonella Heidelberg (SH) in commercial poultry and determine the effects of a probiotic as an antibiotic alternative. Two experiments were conducted to evaluate the risks involved in the use of Enrofloxacin for SE or SH in commercial poultry. Experiment 1 consisted of two trials. In each trial, chickens were assigned to one of three groups; control + SE challenged; Enrofloxacin 25 mg/kg + SE; and Enrofloxacin 50 mg/kg + SE. Chickens received Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, all groups received fresh water without any treatment. All chickens were orally gavaged with 10(7) cfu/chick of SE at 7 days of age and euthanized on 8 days of age. In Experiment 2, turkey poults were assigned to one of the three groups; control + SH; probiotic + SH; and Enrofloxacin 50 mg/kg + SH. Poults received probiotic or Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, poults received fresh water without any treatment. Poults were orally gavaged with 10(7) cfu/poult of SH at 7 days of age. Poults were weighed and humanely killed 24 h post-SH challenge to evaluate serum concentration of fluorescein isothiocyanate-dextran to evaluate intestinal permeability, metagenomics, and SH infection. In both trials of Experiment 1, chickens treated with Enrofloxacin were more susceptible to SE organ invasion and intestinal colonization when compared with control non-treated chickens (P < 0.05). In Experiment 2, poults treated with 50 mg/kg of Enrofloxacin showed an increase in body weight, however, this group also showed an increase in SH susceptibility, intestinal permeability, and lower proportion of Firmicutes and Bacteroidetes, but with control group had the highest proportion of Proteobacteria. By contrast, poults that received the probiotic had the highest
Morales-Barrera, Eduardo; Calhoun, Nicole; Lobato-Tapia, Jose L.; Lucca, Vivian; Prado-Rebolledo, Omar; Hernandez-Velasco, Xochitl; Merino-Guzman, Ruben; Petrone-García, Victor M.; Latorre, Juan D.; Mahaffey, Brittany D.; Teague, Kyle D.; Graham, Lucas E.; Wolfenden, Amanda D.; Baxter, Mikayla F. A.; Hargis, Billy M.; Tellez, Guillermo
The objectives of the present study were to evaluate the risks involved in the use of Enrofloxacin for Salmonella Enteritidis (SE) or Salmonella Heidelberg (SH) in commercial poultry and determine the effects of a probiotic as an antibiotic alternative. Two experiments were conducted to evaluate the risks involved in the use of Enrofloxacin for SE or SH in commercial poultry. Experiment 1 consisted of two trials. In each trial, chickens were assigned to one of three groups; control + SE challenged; Enrofloxacin 25 mg/kg + SE; and Enrofloxacin 50 mg/kg + SE. Chickens received Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, all groups received fresh water without any treatment. All chickens were orally gavaged with 107 cfu/chick of SE at 7 days of age and euthanized on 8 days of age. In Experiment 2, turkey poults were assigned to one of the three groups; control + SH; probiotic + SH; and Enrofloxacin 50 mg/kg + SH. Poults received probiotic or Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, poults received fresh water without any treatment. Poults were orally gavaged with 107 cfu/poult of SH at 7 days of age. Poults were weighed and humanely killed 24 h post-SH challenge to evaluate serum concentration of fluorescein isothiocyanate-dextran to evaluate intestinal permeability, metagenomics, and SH infection. In both trials of Experiment 1, chickens treated with Enrofloxacin were more susceptible to SE organ invasion and intestinal colonization when compared with control non-treated chickens (P < 0.05). In Experiment 2, poults treated with 50 mg/kg of Enrofloxacin showed an increase in body weight, however, this group also showed an increase in SH susceptibility, intestinal permeability, and lower proportion of Firmicutes and Bacteroidetes, but with control group had the highest proportion of Proteobacteria. By contrast, poults that received the probiotic had the highest
Donado-Godoy, Pilar; Byrne, Barbara A; Hume, Michael; León, Maribel; Pérez-Gutiérrez, Enriqué; Vives Flores, Martha J; Clavijo, Viviana; Holguin, Ángela; Romero-Zuñiga, Juan J; Castellanos, Ricardo; Tafur, McAllister; Smith, Woutrina A
Salmonella Paratyphi B dT+ variant (also termed Salmonella Java) and Salmonella Heidelberg are pathogens of public health importance that are frequently isolated from poultry. As a step toward implementing the Colombian Integrated Program for Antimicrobial Resistant Surveillance, this study characterized molecular patterns of Salmonella Paratyphi B dT+ and Salmonella Heidelberg isolated from poultry farms, fecal samples, and retail chicken meat using pulsed-field gel electrophoresis (PFGE). The objective of this study was to determine the genetic relationship among isolates and to determine potential geographically predominant genotypes. Based on PFGE analysis, both serovars exhibited high heterogeneity: the chromosomal DNA fingerprints of 82 Salmonella Paratyphi B dT+ isolates revealed 42 PFGE patterns, whereas the 21 isolates of Salmonella Heidelberg revealed 10 patterns. Similar genotypes of both serovars were demonstrated to be present on farms and in retail outlets. For Salmonella Paratyphi B dT+, closely genetically related strains were found among isolates coming from different farms and different integrated poultry companies within two departments (Santander and Cundinamarca) and also from farms located in the two geographically distant departments. For Salmonella Heidelberg, there were fewer farms with genetically related isolates than for Salmonella Paratyphi B dT+. A possible dissemination of similar genotypes of both serovars along the poultry production chain is hypothesized, and some facilitating factors existing in Colombia are reviewed.
Haley, Bradd J; Pettengill, James; Gorham, Sasha; Ottesen, Andrea; Karns, Jeffrey S; Van Kessel, Jo Ann S
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.
Haley, Bradd J.; Pettengill, James; Gorham, Sasha; Ottesen, Andrea; Karns, Jeffrey S.; Van Kessel, Jo Ann S.
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
Marin, C; Balasch, S; Vega, S; Lainez, M
Prevention of Salmonella contamination of poultry products requires detailed knowledge of the main sources associated with its presence in the production system. The aims of this study were to determine the main sources of Salmonella contamination in broiler production during growing, to assess the risk factors for Salmonella contamination at the end of the rearing period and to determine the main serovars involved in broiler production systems in Eastern Spain. A total of 65 different broiler houses from different farms were sampled. Each house was sampled at different times during the rearing period. First, when the previous flock was taken to the slaughterhouse, samples of dust, surfaces and previous flock faeces were collected. After cleaning and disinfection (C&D), samples of dust and surfaces were also taken. On the first day of rearing, samples of water, bedding, farming boots, meconiums, delivery-box liners and feed were collected. During rearing, feed samples were taken directly from the truck and from feeders. On slaughter day, samples of dust, surfaces, water, feed and faeces were also collected. Finally, two days after slaughter, carriers (rodents, flies and beetles) were trapped. All samples collected were analysed according to ISO 6579:2002 (Annex D) and positive samples were serotyped in accordance with Kauffman-White-Le-Minor technique. Our results showed that all different types of samples collected were contaminated with Salmonella (prevalence ranged between 1.5% and 38.6%). The most contaminated samples related with poultry production were: delivery-box liners (32.0%), faeces samples (31.2%), dust samples (25.0%), farming boots (19.7%) and feed from feeders (16.0%). However, the most important risk factors for Salmonella contamination of the flocks at the end of the rearing period were Salmonella status of the house after cleaning and disinfection, Salmonella status of day-old chick flocks and feed from feeders. Twenty-one different serovars were
Oral administration of the Salmonella Typhimurium vaccine strain Nal2/Rif9/Rtt to laying hens at day of hatch reduces shedding and caecal colonization of Salmonella 4,12:i:-, the monophasic variant of Salmonella Typhimurium.
Kilroy, Sofie; Raspoet, Ruth; Devloo, Rosalie; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip
A new monophasic variant of Salmonella Typhimurium, Salmonella enterica serotype 4,12:i:-, is rapidly emerging. This serotype is now considered to be among the 10 most common serovars isolated from humans in many countries in Europe and in the United States. The public health risk posed by these emerging monophasic Salmonella Typhimurium strains is considered comparable to that of classical Salmonella Typhimurium strains. The serotype 4,12:i:- is frequently isolated from pigs but also poultry are carrying strains from this serotype. In the current study, we evaluated the efficacy of the Salmonella Typhimurium strain Nal2/Rif9/Rtt, a strain contained in the commercially available live vaccines AviPro Salmonella Duo and AviPro Salmonella VacT, against infection with the emerging monophasic variant in poultry. Three independent trials were conducted. In all trials, laying type chicks were orally vaccinated with the Salmonella Typhimurium strain Nal2/Rif9/Rtt at d hatch, while the birds were challenged the next d with a different infection dose in each trial (low, high, and intermediate). For the intermediate-dose study, a seeder bird model was used in which one out of 3 animals were infected while all individual birds were infected in the other trials. Data obtained from each independent trial show that oral administration of the Salmonella Typhimurium strain Nal2/Rif9/Rtt at d hatch reduced shedding, caecal, and internal organ colonization of Salmonella Typhimurium 4,12:i:-, administered at d 2 life. This indicates that Salmonella Typhimurium strain Nal2/Rif9/Rtt can help to control Salmonella 4,12:i:- infections in poultry.
Monack, Denise M.; Raupach, Barbel; Hromockyj, Alexander E.; Falkow, Stanley
Invasive Salmonella typhimurium induces dramatic cytoskeletal changes on the membrane surface of mammalian epithelial cells and RAW264.7 macrophages as part of its entry mechanism. Noninvasive S. typhimurium strains are unable to induce this membrane ruffling. Invasive S. typhimurium strains invade RAW264.7 macrophages in 2 h with 7- to 10-fold higher levels than noninvasive strains. Invasive S. typhimurium and Salmonella typhi, independent of their ability to replicate intracellularly, are cytotoxic to RAW264.7 macrophages and, to a greater degree, to murine bone marrow-derived macrophages. Here, we show that the macrophage cytotoxicity mediated by invasive Salmonella is apoptosis, as shown by nuclear morphology, cytoplasmic vacuolization, and host cell DNA fragmentation. S. typhimurium that enter cells causing ruffles but are mutant for subsequent intracellular replication also initiate host cell apoptosis. Mutant S. typhimurium that are incapable of inducing host cell membrane ruffling fail to induce apoptosis. The activation state of the macrophage plays a significant role in the response of macrophages to Salmonella invasion, perhaps indicating that the signal or receptor for initiating programmed cell death is upregulated in activated macrophages. The ability of Salmonella to promote apoptosis may be important for the initiation of infection, bacterial survival, and escape of the host immune response.
Kim, Hyobi; Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak; Myeong, Donghoon; Chang, Byungjoon; Choe, Nong-Hoon
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.
Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak
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
Moritz, Maike; Wiacek, Claudia; Koethe, Martin; Braun, Peggy G
Contamination of eggshells with Salmonella Enteritidis remains a food safety concern. In many cases human salmonellosis within the EU can be traced back to raw or undercooked eggs and egg products. Atmospheric pressure plasma is a novel decontamination method that can reduce a wide range of pathogens. The aim of this work was to evaluate the possibility of using an effective short time cold plasma treatment to inactivate Salmonella Enteritidis on the eggshell. Therefore, artificially contaminated eggshells were treated with an atmospheric pressure plasma jet under different experimental settings with various exposure times (15-300s), distances from the plasma jet nozzle to the eggshell surface (5, 8 or 12mm), feed gas compositions (Ar, Ar with 0.2, 0.5 or 1.0% O2), gas flow rates (5 and 7slm) and different inoculations of Salmonella Enteritidis (10(1)-10(6)CFU/cm(2)). Atmospheric pressure plasma could reduce Salmonella Enteritidis on eggshells significantly. Reduction factors ranged between 0.22 and 2.27 log CFU (colony-forming units). Exposure time and, particularly at 10(4)CFU/cm(2) inoculation, feed gas had a major impact on Salmonella reduction. Precisely, longer exposure times led to higher reductions and Ar as feed gas was more effective than ArO2 mixtures.
MacLennan, Calman A; Martin, Laura B; Micoli, Francesca
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.
Hernández-Reyes, Casandra; Schikora, Adam
Infections with non-typhoidal Salmonella strains are constant and are a non-negligible threat to the human population. In the last two decades, salmonellosis outbreaks have increasingly been associated with infected fruits and vegetables. For a long time, Salmonellae were assumed to survive on plants after a more or less accidental infection. However, this notion has recently been challenged. Studies on the infection mechanism in vegetal hosts, as well as on plant immune systems, revealed an active infection process resembling in certain features the infection in animals. On one hand, Salmonella requires the type III secretion systems to effectively infect plants and to suppress their resistance mechanisms. On the other hand, plants recognize these bacteria and react to the infection with an induced defense mechanism similar to the reaction to other plant pathogens. In this review, we present the newest reports on the interaction between Salmonellae and plants. We discuss the possible ways used by these bacteria to infect plants as well as the plant responses to the infection. The recent findings indicate that plants play a central role in the dissemination of Salmonella within the ecosystem.
Morpeth, Susan C; Ramadhani, Habib O; Crump, John A
Invasive non-Typhi Salmonella is endemic to sub-Saharan Africa, where it is a leading cause of bloodstream infection. Some host risk factors have been established, but little is known about environmental reservoirs and predominant modes of transmission, so prevention strategies are underdeveloped. Although foodborne transmission from animals to humans predominates in high-income countries, it has been postulated that transmission between humans, both within and outside health care facilities, may be important in sub-Saharan Africa. Antimicrobial resistance to ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol is common among non-Typhi Salmonella strains; therefore, wider use of alternative agents may be warranted for empirical therapy. Development of vaccines targeting the leading invasive non-Typhi Salmonella serotypes Typhimurium and Enteritidis is warranted. The clinical presentation of non-Typhi Salmonella bacteremia is nonspecific and, in the absence of blood culture, may be confused with other febrile illnesses, such as malaria. Much work remains to be done to understand and control invasive non-Typhi Salmonella disease in sub-Saharan Africa.
Melhem, R F; LoVerde, P T
In endemic areas where Salmonella and Schistosoma species co-occur, several lines of evidence suggest a synergistic bacteria-parasite interaction that results in a protracted course for the salmonella infection that has proven difficult to diagnose and therapeutically remedy. In an in vitro system using a pilus-negative and a pilus-producing transductant strain of Salmonella typhimurium we show that pili are the ligands for bacterial adherence to the schistosome surface tegument. Antipili antibodies produced in rabbits against purified pili, purified and digested to monovalent (Fab) fragments, blocked the association of Salmonella sp. to the surface tegument of Schistosoma sp., further demonstrating that pili are the appendages necessary for bacteria-parasite surface interaction. The use of carbohydrates, lectins, and enzymes demonstrated that the bacteria-parasite surface interaction was specific, mediated by pili that specifically recognize and bind to mannose-like receptors, probably glycolipids, on the surface of the worms. We suggest that prolonged salmonellosis in schistosome-infected patients is due to an association of Salmonella sp. with the schistosome worms themselves and further that the schistosome worms provide a multiplication focus for these bacteria in the portal mesenteric system, with a persisting bacteremia following. PMID:6143728
Oscar, Thomas P
Existing data and predictive models were used to define the input settings of a previously developed but modified quantitative risk assessment model (QRAM) for Salmonella and whole chickens. The QRAM was constructed in an Excel spreadsheet and was simulated using @Risk. The retail-to-table pathway was modeled as a series of unit operations and associated pathogen events that included initial contamination at retail, growth during consumer transport, thermal inactivation during cooking, cross-contamination during serving, and dose response after consumption. Published data as well as predictive models for growth and thermal inactivation of Salmonella were used to establish input settings. Noncontaminated chickens were simulated so that the QRAM could predict changes in the incidence of Salmonella contamination. The incidence of Salmonella contamination changed from 30% at retail to 0.16% after cooking to 4% at consumption. Salmonella growth on chickens during consumer transport was the only pathogen event that did not impact the risk of salmonellosis. For the scenario simulated, the QRAM predicted 0.44 cases of salmonellosis per 100,000 consumers, which was consistent with recent epidemiological data that indicate a rate of 0.66-0.88 cases of salmonellosis per 100,000 consumers of chicken. Although the QRAM was in agreement with the epidemiological data, surrogate data and models were used, assumptions were made, and potentially important unit operations and pathogen events were not included because of data gaps and thus, further refinement of the QRAM is needed.
Kim, Aeran; Kang, Min Su; Kwag, Sang Ick; Cho, Jae Keun
Controlling Salmonella in integrated broiler operation is complicated because there are numerous potential sources of Salmonella contamination, including chicks, feed, rodents, wild poultry operations, and the processing plant. The objective of this study was to investigate the distribution of Salmonella through all phases of two integrated broiler operations and to determine the key areas related to the control of all known sources of infection. Two different Salmonella serotypes were observed at integrated broiler chicken company A. S. enteritidis, the predominant company A isolate, was consistently found in the breeder farm, hatcheries, broiler farms, and chicken slaughterhouse. At company B, a total of six different serotypes, S. heidelberg, S. senftenberg, S. enteritidis, S. blockley, S. gallinarum, and S. virchow, were detected. Although S. heidelberg was not found in the broiler farms, it was consistently found in the breeder farm, hatcheries, and chicken slaughterhouse. In addition, S. enteritidis was found in the hatcheries, broiler farm, and chicken slaughterhouse. In order to obtain the genetic clonality, 22 S. enteritidis isolates were digested with XbaI and analyzed by pulsed-field gel electrohporesis (PFGE). A difference in the PFGE pattern was found to be related to the origin of the integrated broiler operation. These data support the critical need to control Salmonella in breeder farms and hatcheries, and demonstrate important points related to the control of infection in large-scale poultry operations of Korea. PMID:17519569
Forkus, Brittany; Ritter, Seth; Vlysidis, Michail; Geldart, Kathryn; Kaznessis, Yiannis N.
Despite the arsenal of technologies employed to control foodborne nontyphoidal Salmonella (NTS), infections have not declined in decades. Poultry is the primary source of NTS outbreaks, as well as the fastest growing meat sector worldwide. With recent FDA rules for phasing-out antibiotics in animal production, pressure is mounting to develop new pathogen reduction strategies. We report on a technology to reduce Salmonella enteritidis in poultry. We engineered probiotic E. coli Nissle 1917, to express and secrete the antimicrobial peptide, Microcin J25. Using in vitro experiments and an animal model of 300 turkeys, we establish the efficacy of this technology. Salmonella more rapidly clear the ceca of birds administered the modified probiotic than other treatment groups. Approximately 97% lower Salmonella carriage is measured in a treated group, 14 days post-Salmonella challenge. Probiotic bacteria are generally regarded as safe to consume, are bile-resistant and can plausibly be modified to produce a panoply of antimicrobial peptides now known. The reported systems may provide a foundation for platforms to launch antimicrobials against gastrointestinal tract pathogens, including ones that are multi-drug resistant. PMID:28094807
Poltronieri, Palmiro; Cimaglia, Fabio; De Lorenzis, Enrico; Chiesa, Maurizio; Mezzolla, Valeria; Reca, Ida Barbara
Food pathogens are the cause of foodborne epidemics, therefore there is a need to detect the pathogens in food productions rapidly. A pre-enrichment culture followed by selective agar plating are standard detection methods. Molecular methods such as qPCR have provided a first rapid protocol for detection of pathogens within 24 h of enrichment culture. Biosensors also may provide a rapid tool to individuate a source of Salmonella contamination at early times of pre-enrichment culture. Forty mL of Salmonella spp. enrichment culture were processed by immunoseparation using the Pathatrix, as in AFNOR validated qPCR protocols. The Salmonella biosensor combined with immunoseparation showed a limit of detection of 100 bacteria/40 mL, with a 400 fold increase to previous results. qPCR analysis requires processing of bead-bound bacteria with lysis buffer and DNA clean up, with a limit of detection of 2 cfu/50 μL. Finally, a protein chip was developed and tested in screening and identification of 5 common pathogen species, Salmonella spp., E. coli, S. aureus, Campylobacter spp. and Listeria spp. The protein chip, with high specificity in species identification, is proposed to be integrated into a Lab-on-Chip system, for rapid and reproducible screening of Salmonella spp. and other pathogen species contaminating food productions. PMID:27110786
Chen, Yu; Wu, Da; Sun, Min; Deng, Mingjun; Cui, Shuhua; Liang, Chengzhu; Geng, Juan; Sun, Tao; Long, Ling; Xiao, Xizhi
While inspecting animal feed for Salmonella contamination, we routinely observed bacterial colonies on selective agars that were similar in appearance to those formed by Salmonella. These were identified as Citrobacter freundii, Proteus mirabilis, and Serratia fonticola using biochemical and serological techniques. Because the presence of these bacterial species confounds identification of Salmonella, we refer to them as "interference bacteria." Polyvalent antisera against these interference bacteria were prepared by immunizing rabbits with a mixture of all three organisms. To minimize or eliminate interference by these bacteria, the polyvalent antisera were introduced between the steps of selective enrichment and Salmonella-selective plating. The antisera raised against the interference bacteria, when combined with neonatal rabbit complement, exhibited specific bactericidal activity against C. freundii, P. mirabilis, and S. fonticola. The respective serum bactericidal assay titers were 2(9), 2(8), and 2(10). In selective broth, polyvalent antisera could also kill the target bacterial cells effectively. We tested 526 samples (186 white fishmeal, 97 red fishmeal, and 243 cattle bone powder) using the polyvalent antisera and found that the rates of contamination of each species of the three respective foods decreased by 58.8, 100, and 83%. Our data indicates that polyvalent sera against C. freundii, P. mirabilis, and S. fonticola can be used as inhibitors to increase the accuracy of Salmonella detection.
Borowsky, Luciane; Corção, Gertrudes; Cardoso, Marisa
Type-1 fimbriae are associated with most Salmonella enterica serovars and are an essential factor for host colonization. Mannanoligosaccharides (MOS), a prebiotic that is agglutinated by type-1 fimbriae, are proposed for the control of enterobacteria colonization and may be an alternative to Salmonella control in pigs. The aim of this study was to evaluate the capability of porcine Salmonella strains to adhere to MOS in vitro. A total of 108 strains of Salmonella sp. isolated from carrier pigs were evaluated for the amplification of fimA and fimH genes, agglutination of MOS and hemagglutination. In all tested strains, amplicons of expected size were detected for both fimA and fimH gene. In the hemagglutination assays, 31 (28.7%) strains presented mannose–sensitive agglutination of erythrocytes, indicating that the strains were expressing type-1 fimbriae. Considering only strains expressing the type-1 fimbriae, 23 (74.2%) presented a strong agglutination of MOS, 3 (9.6%) a weak reaction and 5 (16.2%) none. The results indicate that Salmonella enterica strains expressing type-1 fimbriae can agglutinate effectively in vitro to MOS. PMID:24031388
Rossignol, Aurore; Roche, Sylvie M; Virlogeux-Payant, Isabelle; Wiedemann, Agnès; Grépinet, Olivier; Fredlund, Jennifer; Trotereau, Jérôme; Marchès, Olivier; Quéré, Pascale; Enninga, Jost; Velge, Philippe
Salmonella Gallinarum and Salmonella Enteritidis are genetically closely related however associated with different pathologies. Several studies have suggested that S. Gallinarum is less invasive in vitro than S. Enteritidis. In this study we confirm that the S. Gallinarum strains tested were much less invasive than the S. Enteritidis strains tested in cells of avian or human origin. In addition, the S. Gallinarum T3SS-1-dependent ability to invade host cells was delayed by two to three hours compared to S. Enteritidis, indicating that T3SS-1-dependent entry is less efficient in S. Gallinarum than S. Enteritidis. This was neither due to a decreased transcription of T3SS-1 related genes when bacteria come into contact with cells, as transcription of hilA, invF and sipA was similar to that observed for S. Enteritidis, nor to a lack of functionality of the S. Gallinarum T3SS-1 apparatus as this apparatus was able to secrete and translocate effector proteins into host cells. In contrast, genome comparison of four S. Gallinarum and two S. Enteritidis strains revealed that all S. Gallinarum genomes displayed the same point mutations in each of the main T3SS-1 effector genes sipA, sopE, sopE2, sopD and sopA.
Nandre, Rahul M; Lee, Dajeong; Lee, John Hwa
In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge.
Näsström, Elin; Vu Thieu, Nga Tran; Dongol, Sabina; Karkey, Abhilasha; Voong Vinh, Phat; Ha Thanh, Tuyen; Johansson, Anders; Arjyal, Amit; Thwaites, Guy; Dolecek, Christiane; Basnyat, Buddha; Baker, Stephen; Antti, Henrik
The host-pathogen interactions induced by Salmonella Typhi and Salmonella Paratyphi A during enteric fever are poorly understood. This knowledge gap, and the human restricted nature of these bacteria, limit our understanding of the disease and impede the development of new diagnostic approaches. To investigate metabolite signals associated with enteric fever we performed two dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC/TOFMS) on plasma from patients with S. Typhi and S. Paratyphi A infections and asymptomatic controls, identifying 695 individual metabolite peaks. Applying supervised pattern recognition, we found highly significant and reproducible metabolite profiles separating S. Typhi cases, S. Paratyphi A cases, and controls, calculating that a combination of six metabolites could accurately define the etiological agent. For the first time we show that reproducible and serovar specific systemic biomarkers can be detected during enteric fever. Our work defines several biologically plausible metabolites that can be used to detect enteric fever, and unlocks the potential of this method in diagnosing other systemic bacterial infections.
Nandre, Rahul M.; Lee, Dajeong; Lee, John Hwa
In this study, a genetically engineered live attenuated Salmonella Enteritidis (SE) vaccine was evaluated for its ability to protect against Salmonella Typhimurium (ST) infection in chickens. The birds were orally primed with the vaccine on the 1st day of life and given an oral booster at 5 wk of age. Control birds were orally inoculated with phosphate-buffered saline. Both groups of birds were orally challenged with a virulent ST strain at 9 wk of age. Compared with the control chickens, the vaccinated chickens had significantly higher levels of systemic IgG and mucosal IgA against specific ST antigens and a significantly greater lymphoproliferative response to ST antigens. The excretion of ST into the feces was significantly lower in the vaccinated group than in the control group on days 9 and 13 d after challenge. In addition, the vaccinated group had significantly fewer pronounced gross lesions in the liver and spleen and lower bacterial counts in the internal organs than the control group after challenge. These data indicate that genetically engineered live attenuated SE may induce humoral and cellular immune responses against ST antigens and may confer protection against virulent ST challenge. PMID:25673904
Gerlach, Roman G; Hensel, Michael
Salmonella enterica is a pathogen highly successful in causing a variety of gastrointestinal and systemic diseases in animals and humans. While some serovars of S. enterica are able to infect a broad range of host organisms, other serovars are highly restricted to specific host species. The colonization of hosts by S. enterica depends on the function of a large number of virulence determinants. The molecular analyses of virulence genes demonstrated that most of these loci are clustered within Salmonella Pathogenicity Islands (SPI). SPI1 and SPI2 each encode type III secretion systems (T355) that confer main virulence traits of S. enterica, i.e. invasion, enteropathogenesis and intracellular survival and proliferation. Further SPI encode factors that contribute to intracellular survival, different types of adhesins, or effector proteins of the SPI1-T3SS or SPI2-T3SS. The availability of genome sequences of several serovars of S. enterica also revealed serovar-specific SPI. In this review, the main characteristics of the currently known SPI are summarized with focus on their roles in various animal hosts and putative functions in human infections.
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
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
Kirsh, M; Dembinski, D R; Hartman, P E; Miller, C G
Wild-type Salmonella typhimurium can use carnosine (beta-alanyl-L-histidine) as a source of histidine, but carnosine utilization is blocked in particular mutants defective in the constitutive enzyme peptidase D, the product of the pepD gene. Biochemical evidence for assigning carnosinase activity to peptidase D (a broad-specificity dipeptidase) includes: (i) coelution of carnosinase and dipeptidase activity from diethylaminoethyl-cellulose and Bio-Gel P-300 columns; (ii) coelectrophoresis of carnosinase and dipeptidase on polyacrylamide gels; and (iii) inactivation of carnosinase and dipeptidase activities at identical rates at both 4 and 42 degrees C. Genetic evidence indicates that mutations leading to loss of carnosinase activity map at pepD. Several independent pepD mutants have been isolated by different selection procedures, and the patterns of peptide utilization of strains carrying various pepD alleles have been studied. Many pepD mutations lead to the production of partially active peptidase D enzymes with substrate specificities that differ strikingly from those of the wild-type enzyme. The growth yields of carnosinase-deficient strains growing in Difco nutrient broth indicate that carnosine is the major utilizable source of histidine in this medium. PMID:26655
Suo, Zhiyong; Yang, Xinghong; Avci, Recep; Kellerman, Laura; Pascual, David W; Fries, Marc; Steele, Andrew
Most bacteria, planktonic and sessile, are encapsulated inside loosely bound extracellular polymeric substance (EPS) in their physiological environment. Imaging a bacterium with its capsule requires lengthy sample preparation to enhance the capsular contrast. In this study, Salmonella typhimurium was investigated using atomic force microscopy for a practical means of imaging an encapsulated bacterium in air. The investigation further aimed to determine the relation between the buffers used for preparing the bacterium and the preservation of the capsular material surrounding it. It was observed that rinsing bacteria with HEPES buffer could stabilize and promote capsule formation, while rinsing with PBS, Tris, or glycine removes most of the capsular EPS. For bacteria rinsed with HEPES and air-dried, the height images showed only the contour of the capsular material, while the phase and amplitude images presented the detailed structures of the bacterial surface, including the flagella encapsulated inside the capsular EPS. The encapsulation was attributed to the cross-linking of the acidic exopolysaccharides mediated by the piperazine moiety of HEPES through electrostatic attraction. This explanation is supported by encapsulated bacteria observed for samples rinsed with N,N'-bis(2-hydroxyethyl)-piperazine solution and by the presence of entrapped HEPES within the dry capsular EPS suggested by micro-Raman spectroscopy.
Wilkoff, Lee J.; Westbrook, Louise; Dixon, Glen J.
The persistence of Salmonella typhimurium (V-31) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. Three methods of exposure were employed to contaminate the fabrics: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. After contamination, the fabrics were held in 35 or 78% relative humidity at 25 C. The persistence time of S. typhimurium on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by direct contact or by exposure to dust containing bacteria than when contaminated by exposure to aerosolized cultures. Viable bacterial populations persisted for 24 weeks at relatively high population densities on swatches of wool gabardine, cotton sheeting, cotton knit jersey, and cotton terry cloth exposed by direct contact and held in a humidity of 35%. In 78% humidity, bacterial populations persisted on the fabrics for relatively shorter periods of time regardless of the mode of contamination or fabric type. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 8 weeks in humidities of 35 or 78% and from cotton terry cloth swatches held 6 weeks in the same humidities. Images PMID:4896883
Chorobik, Paulina; Czaplicki, Dominik; Ossysek, Karolina; Bereta, Joanna
Bacterial cancer therapy is a concept more than 100 years old - yet, all things considered, it is still in early development. While the use of many passive therapeutics is hindered by the complexity of tumor biology, bacteria offer unique features that can overcome these limitations. Microbial metabolism, motility and sensitivity can lead to site-specific treatment, highly focused on the tumor and safe to other tissues. Activation of tumor-specific immunity is another important mechanism of such therapies. Several bacterial strains have been evaluated as cancer therapeutics so far, Salmonella Typhimurium being one of the most promising. S. Typhimurium and its derivatives have been used both as direct tumoricidal agents and as cancer vaccine vectors. VNP20009, an attenuated mutant of S. Typhimurium, shows significant native toxicity against murine tumors and was studied in a first-in-man phase I clinical trial for toxicity and anticancer activity. While proved to be safe in cancer patients, insufficient tumor colonization of VNP20009 was identified as a major limitation for further clinical development. Antibody-fragment-based targeting of cancer cells is one of the few approaches proposed to overcome this drawback.
Brãnes, L V; Somers, J M; Kay, W W
The growth of a pleiotropic membrane mutant of Salmonella typhimurium with modified lipopolysaccharide composition was found to be strictly dependent on the peptone component of complex media. Nutritional Shiftdown into minimal media allowed growth for three to four generations. Of 20 commercial peptones, only enzymatic digests supported growth to varying degrees. Neither trace cations, amino acids, vitamins, carbohydrates, lipids, glutathione, polyamines, carbodimides, nor synthetic peptides stimulated growth; however, cells still metabolized carbohydrates, and amino acid transport systems were shown to be functional. A tryptic digest of casein was fractionated into four electrophoretically different peptide fractions of 1,000 to 1,200 molecular weight which supported growth to varying degrees. The best of these was further fractionated to two highly hydrophopic peptides. N-terminal modifications eliminated biological activity. Fluorescein-conjugated goat antibody to rabbit immunoglobulin G was used as a probe to detect antipeptide antibody-peptide complexes on membrane preparations. Cells grown on peptone distributed the peptide into both inner and outer membranes. The peptide could be removed with chaotropic agents, and cells had to be pregrown in peptone-containing media to bind the hydrophobic peptide. The gene (hyp) responsible for peptide auxotrophy was mapped at 44 to 45 units by conjugation. Images PMID:7024254
Diacovich, Lautaro; Lorenzi, Lucía; Tomassetti, Mauro; Méresse, Stéphane; Gramajo, Hugo
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a Gram-negative pathogen that causes various host-specific diseases. During their life cycle, Salmonellae survive frequent exposures to a variety of environmental stresses, e.g. carbon-source starvation. The virulence of this pathogen relies on its ability to establish a replicative niche, named Salmonella-containing vacuole, inside host cells. However, the microenvironment of the SCV and the bacterial metabolic pathways required during infection are largely undefined. In this work we developed different biological probes whose expression is modulated by the environment and the physiological state of the bacterium. We constructed transcriptional reporters by fusing promoter regions to the gfpmut3a gene to monitor the expression profile of genes involved in glucose utilization and lipid catabolism. The induction of these probes by a specific metabolic change was first tested in vitro, and then during different conditions of infection in macrophages. We were able to determine that Entner-Doudoroff is the main metabolic pathway utilized by Salmonella during infection in mouse macrophages. Furthermore, we found sub-populations of bacteria expressing genes involved in pathways for the utilization of different sources of carbon. These populations are modified in presence of different metabolizable substrates, suggesting the coexistence of Salmonella with diverse metabolic states during the infection.
Tsolis, Renée M; Xavier, Mariana N; Santos, Renato L; Bäumler, Andreas J
Salmonella serotypes are a major cause of human morbidity and mortality worldwide. Over the past decades, a series of animal models have been developed to advance vaccine development, provide insights into immunity to infection, and study the pathogenesis of human Salmonella disease. The successive introduction of new animal models, each suited to interrogate previously neglected aspects of Salmonella disease, has ushered in important conceptual advances that continue to have a strong and sustained influence on the ideas driving research on Salmonella serotypes. This article reviews important milestones in the use of animal models to study human Salmonella disease and identify research needs to guide future work.
Andino, A.; Hanning, I.
Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels. PMID:25664339
Andino, A; Hanning, I
Data indicate that prevalence of specific serovars of Salmonella enterica in human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment for S. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars of Salmonella. Additionally, S. enterica serovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to control Salmonella at preharvest and postharvest levels.
Willse, Alan R.; Straub, Tim M.; Wunschel, Sharon C.; Small, Jack A.; Call, Douglas R.; Daly, Don S.; Chandler, Darrell P.
We report on a genome-independent microbial fingerprinting method using nucleic acid microarrays for microbial forensics and epidemiology applications. We demonstrate that the microarray method provides high-resolution differentiation between closely related microorganisms using Salmonella enterica strains. In replicate trials we used a simple 192-probe nonamer array to construct a fingerprint library of 25 closely related Salmonella isolates. Controlling false discovery rate for multiple testing at alpha =.05, at least 295 of 300 pairs of S. enterica isolate fingerprints were found to be statistically distinct using a modified Hotelling Tsquared test. Although we find most pairs of Salmonella fingerprints to be distinct, forensic applications will also require a protocol for library construction and reliable microbial classification against a fingerprint library. We outline additional steps required to produce a protocol for library construction and reliable classification of unknown organisms.
van der Heijden, Joris; Finlay, B Brett
Salmonella is one of the most successful bacterial pathogens that infect humans in both developed and developing countries. In order to cause infection, Salmonella uses type III secretion systems to inject bacterial effector proteins into host cells. In the age of antibiotic resistance, researchers have been looking for new strategies to reduce Salmonella infection. To understand infection and to analyze type III secretion as a potential therapeutic target, research has focused on identification of effectors, characterization of effector functions and how they contribute to disease. Many effector-mediated processes have been identified that contribute to infection but thus far no specific treatment has been found. In this perspective we discuss our current understanding of effector-mediated processes and discuss new techniques and approaches that may help us to find a solution to this worldwide problem.
Van Hoorebeke, S; Van Immerseel, F; De Vylder, J; Ducatelle, R; Haesebrouck, F; Pasmans, F; de Kruif, A; Dewulf, J
An explorative field study was carried out to determine risk factors for Salmonella infections in commercial laying hen flocks. For this purpose, 29 laying hen farms, including farms using conventional and alternative housing systems, were intensively sampled. An on-farm questionnaire was used to collect information on general management practices and specific characteristics of the sampled flock such as flock size, age of the hens, and age of the infrastructure. Salmonella was detected in laying hens from 6 of the 29 sampled farms. Using multivariate logistic regression with the Salmonella status of the flock as an outcome variable, a previous Salmonella contamination on the farm and the age of the production system were identified as risk factors for the presence of Salmonella in laying hens (P<0.05). The housing system did not have a significant influence on the prevalence of Salmonella in the current study.
Mentaberre, G; Porrero, M C; Navarro-Gonzalez, N; Serrano, E; Domínguez, L; Lavín, S
The genus Salmonella is found throughout the world and is a potential pathogen for most vertebrates. It is also the most common cause of food-borne illness in humans, and wildlife is an emerging source of food-borne disease in humans due to the consumption of game meat. Wild boar is one of the most abundant European game species and these wild swine are known to be carriers of zoonotic and food-borne pathogens such as Salmonella. Isolation of the pathogen, serotyping and molecular biology are necessary for elucidating epidemiological connections in multi-host populations. Although disease management at population level can be addressed using a number of different strategies, such management is difficult in free-living wildlife populations due to the lack of experience with the wildlife-livestock interface. Herein, we provide the results of a 4-year Salmonella survey in sympatric populations of wild boar and cattle in the Ports de Tortosa i Beseit National Game Reserve (NE Spain). We also evaluated the effects of two management strategies, cattle removal and increased wild boar harvesting (i.e. by hunting and trapping), on the prevalence of the Salmonella serovar community. The serovars Meleagridis and Anatum were found to be shared by cattle and wild boar, a finding that was confirmed by 100% DNA similarity patterns using pulse field gel electrophoresis. Cattle removal was more efficient than the culling of wild boar as a means of reducing the prevalence of shared serotypes, which underlines the role of cattle as a reservoir of Salmonella for wild boar. To our knowledge, this is the first attempt to manage Salmonella in the wild, and the results have implications for management.
Roppenser, Bernhard; Kwon, Hyunwoo; Canadien, Veronica; Xu, Risheng; Devreotes, Peter N; Grinstein, Sergio; Brumell, John H
SopB is a type 3 secreted effector with phosphatase activity that Salmonella employs to manipulate host cellular processes, allowing the bacteria to establish their intracellular niche. One important function of SopB is activation of the pro-survival kinase Akt/protein kinase B in the infected host cell. Here, we examine the mechanism of Akt activation by SopB during Salmonella infection. We show that SopB-mediated Akt activation is only partially sensitive to PI3-kinase inhibitors LY294002 and wortmannin in HeLa cells, suggesting that Class I PI3-kinases play only a minor role in this process. However, depletion of PI(3,4) P2/PI(3-5) P3 by expression of the phosphoinositide 3-phosphatase PTEN inhibits Akt activation during Salmonella invasion. Therefore, production of PI(3,4) P2/PI(3-5) P3 appears to be a necessary event for Akt activation by SopB and suggests that non-canonical kinases mediate production of these phosphoinositides during Salmonella infection. We report that Class II PI3-kinase beta isoform, IPMK and other kinases identified from a kinase screen all contribute to Akt activation during Salmonella infection. In addition, the kinases required for SopB-mediated activation of Akt vary depending on the type of infected host cell. Together, our data suggest that Salmonella has evolved to use a single effector, SopB, to manipulate a remarkably large repertoire of host kinases to activate Akt for the purpose of optimizing bacterial replication in its host.
Scheidel, Jennifer; Amstein, Leonie; Ackermann, Jörg; Dikic, Ivan; Koch, Ina
The degradation of cytosol-invading pathogens by autophagy, a process known as xenophagy, is an important mechanism of the innate immune system. Inside the host, Salmonella Typhimurium invades epithelial cells and resides within a specialized intracellular compartment, the Salmonella-containing vacuole. A fraction of these bacteria does not persist inside the vacuole and enters the host cytosol. Salmonella Typhimurium that invades the host cytosol becomes a target of the autophagy machinery for degradation. The xenophagy pathway has recently been discovered, and the exact molecular processes are not entirely characterized. Complete kinetic data for each molecular process is not available, so far. We developed a mathematical model of the xenophagy pathway to investigate this key defense mechanism. In this paper, we present a Petri net model of Salmonella xenophagy in epithelial cells. The model is based on functional information derived from literature data. It comprises the molecular mechanism of galectin-8-dependent and ubiquitin-dependent autophagy, including regulatory processes, like nutrient-dependent regulation of autophagy and TBK1-dependent activation of the autophagy receptor, OPTN. To model the activation of TBK1, we proposed a new mechanism of TBK1 activation, suggesting a spatial and temporal regulation of this process. Using standard Petri net analysis techniques, we found basic functional modules, which describe different pathways of the autophagic capture of Salmonella and reflect the basic dynamics of the system. To verify the model, we performed in silico knockout experiments. We introduced a new concept of knockout analysis to systematically compute and visualize the results, using an in silico knockout matrix. The results of the in silico knockout analyses were consistent with published experimental results and provide a basis for future investigations of the Salmonella xenophagy pathway. PMID:27906974
Davies, Mark R.; Broadbent, Sarah E.; Harris, Simon R.; Thomson, Nicholas R.; van der Woude, Marjan W.
The immunodominant lipopolysaccharide is a key antigenic factor for Gram-negative pathogens such as salmonellae where it plays key roles in host adaptation, virulence, immune evasion, and persistence. Variation in the lipopolysaccharide is also the major differentiating factor that is used to classify Salmonella into over 2600 serovars as part of the Kaufmann-White scheme. While lipopolysaccharide diversity is generally associated with sequence variation in the lipopolysaccharide biosynthesis operon, extraneous genetic factors such as those encoded by the glucosyltransferase (gtr) operons provide further structural heterogeneity by adding additional sugars onto the O-antigen component of the lipopolysaccharide. Here we identify and examine the O-antigen modifying glucosyltransferase genes from the genomes of Salmonella enterica and Salmonella bongori serovars. We show that Salmonella generally carries between 1 and 4 gtr operons that we have classified into 10 families on the basis of gtrC sequence with apparent O-antigen modification detected for five of these families. The gtr operons localize to bacteriophage-associated genomic regions and exhibit a dynamic evolutionary history driven by recombination and gene shuffling events leading to new gene combinations. Furthermore, evidence of Dam- and OxyR-dependent phase variation of gtr gene expression was identified within eight gtr families. Thus, as O-antigen modification generates significant intra- and inter-strain phenotypic diversity, gtr-mediated modification is fundamental in assessing Salmonella strain variability. This will inform appropriate vaccine and diagnostic approaches, in addition to contributing to our understanding of host-pathogen interactions. PMID:23818865
Foley, S L; Lynne, A M
Salmonellosis is a worldwide health problem; Salmonella infections are the second leading cause of bacterial foodborne illness in the United States. Approximately 95% of cases of human salmonellosis are associated with the consumption of contaminated products such as meat, poultry, eggs, milk, seafood, and fresh produce. Salmonella can cause a number of different disease syndromes including gastroenteritis, bacteremia, and typhoid fever, with the most common being gastroenteritis, which is often characterized by abdominal pain, nausea, vomiting, diarrhea, and headache. Typically the disease is self-limiting; however, with more severe manifestations such as bacteremia, antimicrobial therapy is often administered to treat the infection. Currently, there are over 2,500 identified serotypes of Salmonella. A smaller number of these serotypes are significantly associated with animal and human disease including Typhimurium, Enteritidis, Newport, Heidelberg, and Montevideo. Increasingly, isolates from these serotypes are being detected that demonstrate resistance to multiple antimicrobial agents, including third-generation cephalosporins, which are recommended for the treatment of severe infections. Many of the genes that encode resistance are located on transmissible elements such as plasmids that allow for potential transfer of resistance among strains. Plasmids are also known to harbor virulence factors that contribute to Salmonella pathogenicity. Several serotypes of medical importance, including Typhimurium, Enteritidis, Newport, Dublin, and Choleraesuis, are known to harbor virulence plasmids containing genes that code for fimbriae, serum resistance, and other factors. Additionally, many Salmonella contain pathogenicity islands scattered throughout their genomes that encode factors essential for bacterial adhesion, invasion, and infection. Salmonella have evolved several virulence and antimicrobial resistance mechanisms that allow for continued challenges to our
Kariuki, Samuel; Gordon, Melita A; Feasey, Nicholas; Parry, Christopher M
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.
Shariat, Nikki; Timme, Ruth E; Pettengill, James B; Barrangou, Rodolphe; Dudley, Edward G
Prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated genes) systems provide adaptive immunity from invasive genetic elements and encompass three essential features: (i) cas genes, (ii) a CRISPR array composed of spacers and direct repeats and (iii) an AT-rich leader sequence upstream of the array. We performed in-depth sequence analysis of the CRISPR-Cas systems in >600 Salmonella, representing four clinically prevalent serovars. Each CRISPR-Cas feature is extremely conserved in the Salmonella, and the CRISPR1 locus is more highly conserved than CRISPR2. Array composition is serovar-specific, although no convincing evidence of recent spacer acquisition against exogenous nucleic acids exists. Only 12% of spacers match phage and plasmid sequences and self-targeting spacers are associated with direct repeat variants. High nucleotide identity (>99.9%) exists across the cas operon among isolates of a single serovar and in some cases this conservation extends across divergent serovars. These observations reflect historical CRISPR-Cas immune activity, showing that this locus has ceased undergoing adaptive events. Intriguingly, the high level of conservation across divergent serovars shows that the genetic integrity of these inactive loci is maintained over time, contrasting with the canonical view that inactive CRISPR loci degenerate over time. This thorough characterization of Salmonella CRISPR-Cas systems presents new insights into Salmonella CRISPR evolution, particularly with respect to cas gene conservation, leader sequences, organization of direct repeats and protospacer matches. Collectively, our data suggest that Salmonella CRISPR-Cas systems are no longer immunogenic; rather, their impressive conservation indicates they may have an alternative function in Salmonella.
Shariat, Nikki; Timme, Ruth E; Pettengill, James B; Barrangou, Rodolphe; Dudley, Edward G
Prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated genes) systems provide adaptive immunity from invasive genetic elements and encompass three essential features: (i) cas genes, (ii) a CRISPR array composed of spacers and direct repeats and (iii) an AT-rich leader sequence upstream of the array. We performed in-depth sequence analysis of the CRISPR-Cas systems in >600 Salmonella, representing four clinically prevalent serovars. Each CRISPR-Cas feature is extremely conserved in the Salmonella, and the CRISPR1 locus is more highly conserved than CRISPR2. Array composition is serovar-specific, although no convincing evidence of recent spacer acquisition against exogenous nucleic acids exists. Only 12 % of spacers match phage and plasmid sequences and self-targeting spacers are associated with direct repeat variants. High nucleotide identity (>99.9 %) exists across the cas operon among isolates of a single serovar and in some cases this conservation extends across divergent serovars. These observations reflect historical CRISPR-Cas immune activity, showing that this locus has ceased undergoing adaptive events. Intriguingly, the high level of conservation across divergent serovars shows that the genetic integrity of these inactive loci is maintained over time, contrasting with the canonical view that inactive CRISPR loci degenerate over time. This thorough characterization of Salmonella CRISPR-Cas systems presents new insights into Salmonella CRISPR evolution, particularly with respect to cas gene conservation, leader sequences, organization of direct repeats and protospacer matches. Collectively, our data suggest that Salmonella CRISPR-Cas systems are no longer immunogenic; rather, their impressive conservation indicates they may have an alternative function in Salmonella.
de Cássia dos Santos da Conceição, Rita; Moreira, Ângela Nunes; Ramos, Roberta Juliano; Goularte, Fabiana Lemos; Carvalhal, José Beiro; Aleixo, José Antonio Guimarães
The immunomagnetic separation (IMS) is a technique that has been used to increase sensitivity and specificity and to decrease the time required for detection of Salmonella in foods through different methodologies. In this work we report on the development of a method for detection of Salmonella in chicken cuts using in house antibody-sensitized microspheres associated to conventional plating in selective agar (IMS-plating). First, protein A-coated microspheres were sensitized with polyclonal antibodies against lipopolysacharide and flagella from salmonellae and used to standardize a procedure for capturing Salmonella Enteritidis from pure cultures and detection in selective agar. Subsequently, samples of chicken meat experimentally contaminated with S. Enteritidis were analyzed immediately after contamination and after 24h of refrigeration using three enrichment protocols. The detection limit of the IMS-plating procedure after standardization with pure culture was about 2x10 CFU/mL. The protocol using non-selective enrichment for 6-8h, selective enrichment for 16-18h and a post-enrichment for 4h gave the best results of S. Enteritidis detection by IMS-plating in experimentally contaminated meat. IMS-plating using this protocol was compared to the standard culture method for salmonellae detection in naturally contaminated chicken cuts and yielded 100% sensitivity and 94% specificity. The method developed using in house prepared magnetic microespheres for IMS and plating in selective agar was able to diminish by at least one day the time required for detection of Salmonella in chicken products by the conventional culture method. PMID:24031199
Wuthe, H H; Rohde, R; Aleksić, S; Schubert, C; Wuthe, S
Fourty-nine adders (Vipera berus L.) and thirty-one grass-snakes (Nitrix natrix L.) from northern Germany were investigated by cloacal swabs. The samples were usually taken in the field and preenriched in peptone water and further-on processed in three steps of tetrathionate. After each step of enrichment the material was transfered to salmonella shigella agar and fuchsine lactose agar (acc. to Endo). Salmonella screening was done by inoculation of lactose positive and lactose negative colonies into lysine iron agar (acc. to Edwards and Fife). Salmonella excretion was found in 59% of the adders and in 68% of the grass-snakes. Some specimens excreted several Salmonella species. 22 different species resp. variants were detected, of which 19 species belonged to subgenus III (Arizona). Subgenus I occured infrequently and was represented by S. duesseldorf, S. heidelberg and S. sunnycove. Three new triphasic variants S. III 17:Z10: e, n, x, z15: z56, S. III 38: (k): z35:z56 and S. III 50:z10:z:z56 of species already known and four so far unknown species S. III (6), 14: 1,v:z (Ar. 7a, 7c:23-31), S. III 21:1,v:z57 (Ar. 22:23-40a,40c), S. III 43:1,v:z56 (Ar. 21:23-38) and S. III 28:z10:z57 (Ar. 35:27-40a,40c) were discovered. The present results suggest that adders and grass-snakes in northern Germany represent autonomous reservoirs of salmonellae. There exist only few relations between the Salmonella species in these kinds of snakes and other European snakes.
Pires, Alda F A; Funk, Julie A; Habing, Greg G; Bolin, Carole
Salmonella enterica (nontyphoidal) is one of the major causes of foodborne diseases in the United States and worldwide. Molecular typing methods are significant tools used to better understand the transmission and ecology of Salmonella in order to implement pre-harvest control measures. The objectives of this study were to describe the Salmonella genotypes, the distribution of isolate subtypes from different ecological niches (i.e., barn environment, nursery, and individual pigs) and their evolution over time in a longitudinal study conducted in three finishing sites (housing pigs from 10 weeks of age until slaughter at 24-26 weeks of age). Among the 107 Salmonella isolates submitted for pulsed-field gel electrophoresis (PFGE) analysis, there were 25 distinct subtypes. PFGE genotyping results were consistent with the serotype findings. A large number of distinguishable PFGE patterns (i.e., within the same serovar) were observed and different combinations of subtypes were identified within and across sites and cohorts. New subtypes may result of the introduction of new strains, genetic changes, or ongoing transmission of evolved strains within the production system. The same subtypes were detected intermittently during the study period, which suggests the persistence of indistinguishable subtypes in this production system. In addition, this study suggests persistence of the same subtype over several cohorts of pigs and potential residual contamination from the barn. Factors affecting adaptation and transmission of Salmonella within and among ecological systems (e.g., finishing pigs, nursery, and environment) should be further investigated. Understanding genotypic diversity of Salmonella in different ecological niches during pre-harvest may contribute to the development of more targeted and cost effective control programs during nursery and finishing phases.
Hydeskov, H B; Guardabassi, L; Aalbaek, B; Olsen, K E P; Nielsen, S S; Bertelsen, M F
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.
Tennant, Sharon M.; Diallo, Souleymane; Levy, Haim; Livio, Sofie; Sow, Samba O.; Tapia, Milagritos; Fields, Patricia I.; Mikoleit, Matthew; Tamboura, Boubou; Kotloff, Karen L.; Nataro, James P.; Galen, James E.; Levine, Myron M.
Background In sub-Saharan Africa, non-typhoidal Salmonella (NTS) are emerging as a prominent cause of invasive disease (bacteremia and focal infections such as meningitis) in infants and young children. Importantly, including data from Mali, three serovars, Salmonella enterica serovar Typhimurium, Salmonella Enteritidis and Salmonella Dublin, account for the majority of non-typhoidal Salmonella isolated from these patients. Methods We have extended a previously developed series of polymerase chain reactions (PCRs) based on O serogrouping and H typing to identify Salmonella Typhimurium and variants (mostly I 4,,12:i:-), Salmonella Enteritidis and Salmonella Dublin. We also designed primers to detect Salmonella Stanleyville, a serovar found in West Africa. Another PCR was used to differentiate diphasic Salmonella Typhimurium and monophasic Salmonella Typhimurium from other O serogroup B, H:i serovars. We used these PCRs to blind-test 327 Salmonella serogroup B and D isolates that were obtained from the blood cultures of febrile patients in Bamako, Mali. Principal Findings We have shown that when used in conjunction with our previously described O-serogrouping PCR, our PCRs are 100% sensitive and specific in identifying Salmonella Typhimurium and variants, Salmonella Enteritidis, Salmonella Dublin and Salmonella Stanleyville. When we attempted to differentiate 171 Salmonella Typhimurium (I 4,[ 5],12:i:1,2) strains from 52 monophasic Salmonella Typhimurium (I 4,,12:i:-) strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,,12:i:- strains. Conclusion We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries. PMID:20231882
March 1982/Accepted 2 July 1982 ___A mouse-virulent Salmonella typhinturitim hybrid (H42), which expresses the -ac Salmonella typhi Vi antigen in addition... Salmonella typhi surface antigens as ments in which S. typhimurium hybrids, ex- challenge organisms in vaccinated Swiss-Web- pressing different... Salmonella typhi anti- ride-protein conjugates induce protection against infec- gens. Infect. Immun. 24:90-93. lion with Salmonella typhimurium. Infect. Immun
Berghaus, R D; Thayer, S G; Maurer, J J; Hofacre, C L
The objective of this study was to evaluate the effect of vaccination of breeder chickens on Salmonella prevalences and loads in breeder and broiler chicken flocks. Chickens housed on six commercial breeder farms were vaccinated with a killed Salmonella vaccine containing Salmonella Typhimurium, Salmonella Enteritidis, and Salmonella Kentucky. Unvaccinated breeders placed on six additional farms served as controls. Eggs from vaccinated and unvaccinated breeder flocks were kept separately in the hatchery, and the resulting chicks were used to populate 58 commercial broiler flock houses by using a pair-matched design. Vaccinated breeder flocks had significantly higher Salmonella-specific antibody titers than did the unvaccinated breeder flocks, although they did not differ significantly with respect to environmental Salmonella prevalences or loads. Broiler flocks that were the progeny of vaccinated breeders had significantly lower Salmonella prevalences and loads than broiler flocks that were the progeny of unvaccinated breeders. After adjusting for sample type and clustering at the farm level, the odds of detecting Salmonella in samples collected from broiler flocks originating from vaccinated breeders were 62% lower (odds ratio [95% confidence interval] = 0.38 [0.21, 0.68]) than in flocks from unvaccinated breeders. In addition, the mean load of culture-positive samples was lower in broilers from vaccinated breeders by 0.30 log most probable number per sample (95% confidence interval of -0.51, -0.09; P = 0.004), corresponding to a 50% decrease in Salmonella loads. In summary, vaccination of broiler breeder pullets increased humoral immunity in the breeders and reduced Salmonella prevalences and loads in their broiler progeny, but did not significantly decrease Salmonella in the breeder farm environment.
Ramachandran, Girish; Aheto, Komi; Shirtliff, Mark E; Tennant, Sharon M
Salmonella enterica serovar Typhimurium, an enteric pathogen that causes a self-limiting gastroenteritis, forms biofilms on different surfaces. In sub-Saharan Africa, Salmonella Typhimurium of a novel sequence type (ST) 313 was identified and produces septicemia in the absence of gastroenteritis. No animal reservoir has been identified, and it is hypothesized that transmission occurs via human to human. In this study, we show that invasive Salmonella Typhimurium ST313 strains from Mali are poor biofilm producers compared to Salmonella Typhimurium ST19 strains, which are found worldwide and are known to be associated with gastroenteritis. We evaluated biofilms using crystal violet staining, examination of the red, dry and rough morphotype, pellicle formation and a continuous flow system. One month-old Salmonella Typhimurium ST19 colonies survived in the absence of exogenous nutrients and were highly resistant to sodium hypochlorite treatment compared to Salmonella Typhimurium ST313. This study for the first time demonstrates the comparative biofilm-forming ability and long-term survival of clinical Salmonella Typhimurium ST19 and ST313 isolates. Salmonella Typhimurium ST19 strains are strong biofilm producers and can survive desiccation compared to Salmonella Typhimurium ST313 that form weak biofilms and survive poorly following desiccation. Our data suggest that like Salmonella Typhi, Salmonella Typhimurium ST313 lack mechanisms that allow it to persist in the environment.
Pfleger, Silvia; Benyr, Gerald; Sommer, Regina; Hassl, Andreas
During a period of about three years the faeces of five species of amphibians (35 individuals) and of 23 species of reptiles (103 individuals) living in one vivarium with terrariums imitating different types of ecosystems were examined for salmonellae. From 54 out of 376 faecal samples Salmonella spp. was isolated (= 14%). Twenty-one different Salmonella strains were found. Salmonellae could be isolated about twice as often from animals kept under arid or mesic conditions than from animals living in humid or aquatic environments although this was not statistically significant. Statistically significant for the rate of Salmonella excretion was the animals' diet and the class the animals are belonging to. Animals feeding on mice (p = 0.04) and reptiles in general (p = 0.04) were more commonly excreting Salmonella. Duration of stay was also a significant factor (p = 0.0005), whereby the relative risk for Salmonella excretion increased with the factor 2.91 per year during the investigation period. Salmonella strains were not necessarily transferred among animals living in the same terrarium or among the inhabitants of different terrariums. The pattern of Salmonella excretion was generally fragmentary. The outsides as well as the insides of the walls of the terrariums were also tested for salmonellae several times, but salmonellae have never been isolated.
Silva, Claudia; Calva, Edmundo; Maloy, Stanley
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.
Curt, Alexander; Zhang, Jiuli; Minnerly, Justin; Jia, Kailiang
Salmonella typhimurium infects both intestinal epithelial cells and macrophages. Autophagy is a lysosomal degradation pathway that is present in all eukaryotes. Autophagy has been reported to limit the Salmonella replication in Caenorhabditis elegans and in mammals. However, it is unknown whether intestinal autophagy activity plays a role in host defense against Salmonella infection in C. elegans. In this study, we inhibited the autophagy gene bec-1 in different C. elegans tissues and examined the survival of these animals following Salmonella infection. Here we show that inhibition of the bec-1 gene in the intestine but not in other tissues confers susceptibility to Salmonella infection, which is consistent with recent studies in mice showing that autophagy is involved in clearance of Salmonella in the intestinal epithelial cells. Therefore, the intestinal autophagy activity is essential for host defense against Salmonella infection from C. elegans to mice, perhaps also in humans.
von Tavel, L; Fivian, R; Kirchhofer, M; Boujon, P; Hirsbrunner, G
In spring 2005, the outbreak of contagious abortion caused by Salmonella Abortusovis in 6 sheep flocks in Switzerland led to considerable economic losses. The Swiss small ruminant health service (BGK) evaluated this case. The aim was to identify the source of the epidemic in order to avoid further spread of infection and to evaluate the possibility of using vaccination. Moreover, a strategy for prevention of future outbreaks was developed. This article aims to increase disease awareness of food animal practitioners for Salmonella Abortusovis abortion in sheep.
Gunn, John S.; Marshall, Joanna M.; Baker, Stephen; Dongol, Sabina; Charles, Richelle C.; Ryan, Edward T.
Typhoid (enteric fever) remains a major cause of morbidity and mortality worldwide, causing over 21 million new infections annually, with the majority of deaths occurring in young children. As typhoid fever-causing Salmonella have no known environmental reservoir, the chronic, asymptomatic carrier state is thought to be a key feature of continued maintenance of the bacterium within human populations. In spite of the importance of this disease to public health, our understanding of the molecular mechanisms that catalyze carriage, as well as our ability to reliably identify and treat the Salmonella carrier state, have only recently begun to advance. PMID:25065707
Jammal, M H; Guidon, J; Chiche, L; Tselikas, L; Tiev, K-P; Tolédano, C; Josselin-Mahr, L; Gain, M; Cabane, J; Kettaneh, A
Mycotic aneurysms are rare, remain asymptomatic for a long time, and may be life threatening by their rupture if therapy is delayed. Historically associated with Streptococcus pyogenes and Staphylococcus aureus, they now frequently involve Salmonella species in elderly or immunodeficient patients, and complicate vascular investigation or surgical procedures. Frequently located in the abdominal aorta, they can also be found rarely in other location. Therapy associates antibiotics and surgical debridement with reestablishment of vascular continuity. We report a case of ruptured popliteal aneurysm with Salmonella bredney bacteraemia.
Switt, Andrea I Moreno; Sulakvelidze, Alexander; Wiedmann, Martin; Kropinski, Andrew M; Wishart, David S; Poppe, Cornelis; Liang, Yongjie
Since this book was originally published in 2007 there has been a significant increase in the number of Salmonella bacteriophages, particularly lytic virus, and Salmonella strains which have been fully sequenced. In addition, new insights into phage taxonomy have resulted in new phage genera, some of which have been recognized by the International Committee of Taxonomy of Viruses (ICTV). The properties of each of these genera are discussed, along with the role of phage as agents of genetic exchange, as therapeutic agents, and their involvement in phage typing.
De Cort, W; Geeraerts, S; Balan, V; Elroy, M; Haesebrouck, F; Ducatelle, R; Van Immerseel, F
Consumption of contaminated poultry meat is an important cause of Salmonella infections in humans. Therefore, there is a need for control methods that protect broilers from day-of-hatch until slaughter age against infection with Salmonella. Colonization-inhibition, a concept in which a live Salmonella strain is orally administered to day-old chickens and protects against subsequent challenge, can potentially be used as control method. In this study, the safety and efficacy of a Salmonella Enteritidis ΔhilAssrAfliG strain as a colonization-inhibition strain for protection of broilers against Salmonella Enteritidis was evaluated. After administration of the Salmonella Enteritidis ΔhilAssrAfliG strain to day-old chickens, this strain could not be isolated from the gut, internal organs or faeces after 21 days of age. In addition, administration of this strain to one-day-old broiler chickens decreased faecal shedding and caecal and internal organ colonization of a Salmonella Enteritidis challenge strain administered one day later using a seeder bird model. To our knowledge, this is the first report of an attenuated Salmonella strain for which both the safety and efficacy has been shown in long-term experiments (until slaughter age) in broiler strain can potentially be used as a live colonization-inhibition strain for controlling Salmonella Enteritidis infections in broilers.
Mozola, Mark; Botimer, Maximilian; Jagadics, Carolyn; Norton, Paul; Caballero, Oscar; Enslin, Nicole; Biswas, Preetha; Rice, Jennifer
A collaborative study was conducted to evaluate performance of the ANSR for Salmonella assay for identification of Salmonella spp. from colony picks taken from selective/differential agar media. The ANSR Salmonella assay is an isothermal nucleic acid amplification test based on the nicking enzyme amplification reaction chemistry. The test can be completed in less than 40 min including sample preparation. A total of 18 laboratories representing industry, government, academic, and commercial testing laboratories participated in the study. Each collaborator tested up to 84 samples, comprised of colony picks of six Salmonella spp. and six non-salmonellae taken from six selective/differential agar media as well as tryptic soy agar. A total of 1441 analyses were performed, 1416 of which gave the correct identification, for overall accuracy of 98.3%. For identification of Salmonella spp., 755 of 756 tests (99.9%) produced the correct result. For identification of non-salmonellae as such, 661 of 685 assays (96.5%) produced the correct result. Of the 18 laboratories, 15 produced data sets with 99-100% accuracy. The majority of false-positive results were clustered in three laboratories; analysis of raw data suggests procedural difficulties in at least two cases, which may explain the atypical data from these collaborators. The ANSR Salmonella assay can be used as a rapid, accurate adjunct or alternative to biochemical testing for identification of presumptive Salmonella spp. isolates.
Han, Sanghyun; Micallef, Shirley Ann
Several outbreaks of Salmonella enterica infections have been linked to tomatoes. One cost-effective way to complement on-farm preventive Good Agricultural Practices is to identify cultivars with inherent decreased susceptibility to Salmonella colonization. Fruit and leaves of 13 tomato cultivars with distinct phenotypes were screened to evaluate their susceptibility to Salmonella epiphytic colonization. Field-grown fruit or gnotobiotically grown seedling leaves were spot inoculated in replicate with either Salmonella Typhimurium LT2 or a tomato outbreak-associated strain of Salmonella Newport. Initial loads of the Salmonella inocula were 2.5 log CFU per fruit and 3.5 or 7.0 log CFU per seedling. Salmonella cells were retrieved and enumerated using direct plating after 24 h of incubation at room temperature for fruit and 72 h at 26°C during the day and 18°C at night for seedling leaves. Epiphytic colonization of fruit by S. enterica was cultivar-dependent and serotype-specific, but did not necessarily correlate with leaf colonization. Fruit of cultivar Heinz-1706 were the least colonized by Salmonella Newport, while the highest populations were retrieved from fruit of Nyagous. By contrast, seedling leaves supporting the lowest populations were Florida 91 VF and the highest were Virginia Sweets for Salmonella Newport. For Salmonella Typhimurium the lowest was Nyagous and the highest was Heinz-1706 and Moneymaker. The tomato outbreak strain of Salmonella Newport attained higher population densities on fruit than did Salmonella Typhimurium, suggesting better adaptation to tomato fruit colonization. Salmonella Newport populations were significantly lower on leaves, but not fruit of the near-isogenic line Movione, compared with the parent cultivar Moneymaker, suggesting the immunity conferring gene Pto could be responding to this outbreak strain. Susceptibility of tomato fruit to Salmonella colonization is highly variable and could be one criterion for cultivar
Fong, Karen; Wang, Siyun
In North America, outbreaks of Salmonella have been linked to low-water activity (aw) foods, such as nuts and seeds. These outbreaks have implicated an assortment of Salmonella serotypes. Some Salmonella serotypes (e.g., Enteritidis and Typhimurium) cause high proportions of salmonellosis. Nevertheless, there has recently been an emergence of uncommon Salmonella serotypes and strains (e.g., Tennessee, Hartford, and Thompson) in low-aw foods. The aim of this study was to evaluate the survival characteristics of Salmonella serotypes Enteritidis, Typhimurium, Tennessee, Hartford, and Thompson in three low-aw food ingredients with varying aw: peanut oil (aw = 0.521 ± 0.003), peanut shell (aw = 0.321 ± 0.20), and chia seeds (aw = 0.585 ± 0.003). The survival of individual Salmonella strains on each food matrix was monitored for a maximum of 150 days by spreading the bacterial cells onto Luria-Bertani and/or xylose lysine deoxycholate agar. Overall, Salmonella survived for the longest periods of time in peanut oil (96 ± 8 days), followed by chia seeds (94 ± 46 days). The survival period was substantially reduced on the surface of peanut shell (42 ± 49 h), although PCR after 70 days of incubation revealed the presence of Salmonella cells. In addition, Salmonella exhibited a strain-specific response in the three low-aw foods tested. Salmonella Hartford was identified as highly persistent in all low-aw food matrices, whereas Salmonella Typhimurium was the least persistent. The current research emphasizes the adaptable nature of Salmonella to low-aw food ingredients. This may pose additional problems owing to the downstream production of various end products. Additionally, unique survival characteristics among Salmonella strains highlight the need for tailored mitigation strategies regarding high-risk Salmonella strains in the food industry.
Phoba, M-F; De Boeck, H; Ifeka, B B; Dawili, J; Lunguya, O; Vanhoof, R; Muyembe, J-J; Van Geet, C; Bertrand, S; Jacobs, J
Salmonella enterica is the leading cause of bloodstream infection in children in sub-Saharan Africa, but few data are available from Central-Africa. We documented during the period November 2011 to May 2012 an epidemic increase in invasive Salmonella bloodstream infections in HGR Bwamanda, a referral hospital in Equateur Province, DR Congo. Salmonella spp. represented 90.4 % (103 out of 114) of clinically significant blood culture isolates and comprised Salmonella Typhimurium (54.4 %, 56 out of 103), Salmonella Enteritidis (28.2 %, 29 out of 103) and Salmonella Typhi (17.5 %, 18 out of 103), with Salmonella Enteritidis accounting for most of the increase. Most (82 out of 103, 79.6 %) isolates were obtained from children < 5 years old. Median ages of patients infected with Salmonella Typhimurium and Salmonella Enteritidis were 14 months (14 days to 64 years) and 19 months (3 months to 8 years) respectively. Clinical presentation was non-specific; the in-hospital case fatality rate was 11.1 %. More than two thirds (69.7 %, 53 out of 76) of children < 5 years for whom laboratory data were available had Plasmodium falciparum infection. Most (83/85, 97.6 %) non-typhoid Salmonella isolates as well as 6/18 (33.3 %) Salmonella Typhi isolates were multidrug resistant (i.e. resistant to the first-line oral antibiotics amoxicillin, trimethoprim-sulfamethoxazole and chloramphenicol), one (1.0 %) Salmonella Typhimurium had decreased ciprofloxacin susceptibility owing to a point mutation in the gyrA gene (Gly81Cys). Multilocus variable-number tandem-repeat (MLVA) analysis of the Salmonella Enteritidis isolates revealed closely related patterns comprising three major and four minor profiles, with differences limited to one out of five loci. These data show an epidemic increase in clonally related multidrug-resistant Salmonella bloodstream infection in children in DR Congo.
Danyluk, Michelle D.; Worobo, Randy W.; Wiedmann, Martin
Salmonella accounts for approximately 50% of produce-associated outbreaks in the United States, several of which have been traced back to contamination in the produce production environment. To quantify Salmonella diversity and aid in identification of Salmonella contamination sources, we characterized Salmonella isolates from two geographically diverse produce-growing regions in the United States. Initially, we characterized the Salmonella serotype and subtype diversity associated with 1,677 samples collected from 33 produce farms in New York State (NYS). Among these 1,677 samples, 74 were Salmonella positive, yielding 80 unique isolates (from 147 total isolates), which represented 14 serovars and 23 different pulsed-field gel electrophoresis (PFGE) types. To explore regional Salmonella diversity associated with production environments, we collected a smaller set of samples (n = 65) from South Florida (SFL) production environments and compared the Salmonella diversity associated with these samples with the diversity found among NYS production environments. Among these 65 samples, 23 were Salmonella positive, yielding 32 unique isolates (from 81 total isolates), which represented 11 serovars and 17 different PFGE types. The most common serovars isolated in NYS were Salmonella enterica serovars Newport, Cerro, and Thompson, while common serovars isolated in SFL were Salmonella serovars Saphra and Newport and S. enterica subsp. diarizonae serovar 50:r:z. High PFGE type diversity (Simpson's diversity index, 0.90 ± 0.02) was observed among Salmonella isolates across both regions; only three PFGE types were shared between the two regions. The probability of three or fewer shared PFGE types was <0.000001; therefore, Salmonella isolates were considerably different between the two sampled regions. These findings suggest the potential for PFGE-based source tracking of Salmonella in production environments. PMID:24747908
Foster, J W; Hall, H K
Salmonella typhimurium can encounter a wide variety of environments during its life cycle. One component of the environment which will fluctuate widely is pH. In nature, S. typhimurium can experience and survive dramatic acid stresses that occur in diverse ecological niches ranging from pond water to phagolysosomes. However, in vitro the organism is very sensitive to acid. To provide an explanation for how this organism survives acid in natural environments, the adaptive ability of S. typhimurium to become acid tolerant was tested. Logarithmically grown cells (pH 7.6) shifted to mild acid (pH 5.8) for one doubling as an adaptive procedure were 100 to 1,000 times more resistant to subsequent strong acid challenge (pH 3.3) than were unadapted cells shifted directly from pH 7.6 to 3.3. This acidification tolerance response required protein synthesis and appears to be a specific defense mechanism for acid. No cross protection was noted for hydrogen peroxide, SOS, or heat shock. Two-dimensional polyacrylamide gel electrophoretic analysis of acid-regulated polypeptides revealed 18 proteins with altered expression, 6 of which were repressed while 12 were induced by mild acid shifts. An avirulent phoP mutant was 1,000-fold more sensitive to acid than its virulent phoP+ parent, suggesting a correlation between acid tolerance and virulence. The Mg2(+)-dependent proton-translocating ATPase was also found to play an important role in acid tolerance. Mutants (unc) lacking this activity were unable to mount an acid tolerance response and were extremely acid sensitive. In contrast to these acid-sensitive mutants, a constitutively acid-tolerant mutant (atr) was isolated from wild-type LT2 after prolonged acid exposure. This mutant overexpressed several acidification tolerance response polypeptides. The data presented reveal an important acidification defense modulon with broad significance toward survival in biologically hostile environments.
Cliver, Dean O
Cutting boards are commonly perceived as important fomites in cross-contamination of foods with agents such as Salmonella spp., despite the lack of supporting epidemiological data. A variety of woods and plastics have been used to make work surfaces for cutting. In general, wood is said to dull knives less than plastic, and plastic is seen as less porous than wood. Research to model the hypothetical cross-contamination has been done in a variety of ways and has yielded a variety of results. At least some of the work with knife-scarred plastic indicates that the surface is very difficult to clean and disinfect, although this may vary among the polymers used. High-density polyethylene, which is most used in commercial applications, has been shown to delaminate in response to knife scarring. Wood is intrinsically porous, which allows food juices and bacteria to enter the body of the wood unless a highly hydrophobic residue covers the surface. The moisture is drawn in by capillary action until there is no more free fluid on the surface, at which point immigration ceases. Bacteria in the wood pores are not killed instantly, but neither do they return to the surface. Destructive sampling reveals infectious bacteria for hours, but resurrection of these bacteria via knife edges has not been demonstrated. Small plastic cutting boards can be cleaned in a dishwasher (as can some specially treated wooden boards), but the dishwasher may distribute the bacteria onto other food-contact surfaces. Most small wooden boards (i.e., those with no metal joiners in them) can be sterilized in a microwave oven, but this should be unnecessary if accumulation of food residues is prevented. However, 2 epidemiological studies seem to show that cutting board cleaning habits have little influence on the incidence of sporadic salmonellosis. Further, one of these studies indicated that use of plastic cutting boards in home kitchens is hazardous, whereas use of wooden cutting boards is not.
Fiorino, Fabio; Rondini, Simona; Micoli, Francesca; Lanzilao, Luisa; Alfini, Renzo; Mancini, Francesca; MacLennan, Calman A.; Medaglini, Donata
Salmonella enterica serovars Typhimurium and Enteritidis are the predominant causes of invasive non-typhoidal Salmonella (iNTS) disease. Considering the co-endemicity of S. Typhimurium and S. Enteritidis, a bivalent vaccine formulation against both pathogens is necessary for protection against iNTS disease, thus investigation of glycoconjugate combination is required. In the present work, we investigated the immune responses induced by S. Typhimurium and S. Enteritidis monovalent and bivalent glycoconjugate vaccines adjuvanted with aluminum hydroxide (alum) only or in combination with cytosine-phosphorothioate-guanine oligodeoxynucleotide (CpG). Humoral and cellular, systemic and local, immune responses were characterized in two different mouse strains. All conjugate vaccines elicited high levels of serum IgG against the respective O-antigens (OAg) with bactericidal activity. The bivalent conjugate vaccine induced systemic production of antibodies against both S. Typhimurium and S. Enteritidis OAg. The presence of alum or alum + CpG adjuvants in vaccine formulations significantly increased the serum antigen-specific antibody production. The alum + CpG bivalent vaccine formulation triggered the highest systemic anti-OAg antibodies and also a significant increase of anti-OAg IgG in intestinal washes and fecal samples, with a positive correlation with serum levels. These data demonstrate the ability of monovalent and bivalent conjugate vaccines against S. Typhimurium and S. Enteritidis to induce systemic and local immune responses in different mouse strains, and highlight the suitability of a bivalent glycoconjugate formulation, especially when adjuvanted with alum + CpG, as a promising candidate vaccine against iNTS disease. PMID:28289411
A comparative study on invasion, survival, modulation of oxidative burst, and nitric oxide responses of macrophages (HD11), and systemic infection in chickens by prevalent poultry Salmonella serovars.
He, Haiqi; Genovese, Kenneth J; Swaggerty, Christina L; Nisbet, David J; Kogut, Michael H
Poultry is a major reservoir for foodborne Salmonella serovars. Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Heidelberg, Salmonella Kentucky, and Salmonella Senftenberg are the most prevalent serovars in U.S. poultry. Information concerning the interactions between different Salmonella species and host cells in poultry is lacking. In the present study, the above mentioned Salmonella serovars were examined for invasion, intracellular survival, and their ability to modulate oxidative burst and nitric oxide (NO) responses in chicken macrophage HD11 cells. All Salmonella serovars demonstrated similar capacity to invade HD11 cells. At 24 h post-infection, a 36-43% reduction of intracellular bacteria, in log(10)(CFU), was observed for Salmonella Typhimurium, Salmonella Heidelberg, Salmonella Kentucky, and Salmonella Senftenberg, whereas a significantly lower reduction (16%) was observed for Salmonella Enteritidis, indicating its higher resistance to the killing by HD11 cells. Production of NO was completely diminished in HD11 cells infected with Salmonella Typhimurium and Salmonella Enteritidis, but remained intact when infected with Salmonella Heidelberg, Salmonella Kentucky, and Salmonella Senftenberg. Phorbol myristate acetate-stimulated oxidative burst in HD11 cells was greatly impaired after infection by each of the five serovars. When newly hatched chickens were challenged orally, a high rate (86-98%) of systemic infection (Salmonella positive in liver/spleen) was observed in birds challenged with Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Heidelberg, and Salmonella Kentucky, while only 14% of the birds were Salmonella Senftenberg positive. However, there was no direct correlation between systemic infection and in vitro differential intracellular survival and modulation of NO response among the tested serovars.
Arvizu-Medrano, Sofía M; Escartín, Eduardo F
The effect of acid shock with hydrochloric, citric, or lactic acid on the survival and growth of Salmonella Typhi and Salmonella Typhimurium in acidified broth was evaluated. Salmonella serovars were acid shocked (1 h at 35 degrees C) in Trypticase soy broth acidified with hydrochloric, citric, or lactic acid at pH 5.5. Unshocked cells were exposed to the same media that had been neutralized before use to pH 7.0. Shocked and unshocked cells were inoculated into broth acidified with hydrochloric acid (pH 3.0), citric acid (pH 3.0), or lactic acid (pH 3.8), and growth and survival ability were evaluated. The acid shock conferred protection to Salmonella against the lethal effects of low pH and organic acids. The adaptive response was not specific to the anion used for adaptation. The biggest difference in reduction of survival between shocked and unshocked strains (approximately 2 log CFU/ml) was observed when the microorganisms were shocked with lactic acid and then challenged with citric acid. Salmonella Typhi was more tolerant of citric acid than was Salmonella Typhimurium, but Salmonella Typhimurium had higher acid tolerance in response to acid shock than did Salmonella Typhi. The acid shock decreased the extension of the lag phase and enhanced the physiological state values of Salmonella Typhi and Salmonella Typhimurium when the pH of growth was 4.5. This increased ability to tolerate acidity may have an important impact on food safety, especially in the case of Salmonella Typhi, given the very low infectious dose of this pathogen.
Stoddard, Robyn A; Gulland, M D Frances; Atwill, E Rob; Lawrence, Judy; Jang, Spencer; Conrad, Patricia A
Campylobacter and Salmonella spp. prevalence and antimicrobial drug sensitivity were determined in northern elephant seals that had not entered the water and seals that were stranded on the California coast. Stranded seals had a higher prevalence of pathogenic bacteria, possibly from terrestrial sources, which were more likely to be resistant.
Higgins, R; Désilets, A; Cantin, M; Messier, S; Khakhria, R; Ismaïl, J; Mulvey, M R; Daignault, D; Caron, H
Salmonellosis due to Salmonella Give involving cows, a goat, and an ostrich over a 6-month period was investigated. Cases were found in 4 different regions. Antimicrobial susceptibility patterns, phagetyping, and pulsed-field gel electrophoresis analyses confirmed that all isolates belonged to the same clone. A common source of infection was suspected. PMID:9426945
Recent work has called attention to the unequal competitive abilities of different Salmonella serotypes in standard broth culture and plating media. Such serotypes include Enteritidis and Typhimurium that are specifically targeted in some regulatory and certification programs because they cause a l...
This study was undertaken to determine the prevalence of Salmonella in the subiliac lymph nodes (LN) of cattle. Lymph node samples were obtained from carcasses of cull and feedlot cattle at commercial packing plants. Lymph nodes were trimmed of all fat, surface sterilized by submersion in boiling ...
One of the principal recurring themes during the search for effective responses to the continuing public health and economic problems caused by Salmonella contamination of eggs has concerned reducing the susceptibility of egg-laying chickens to infection. Decreasing the overall prevalence or level o...
Nascimento, Maristela da Silva do; Brum, Daniela Merlo; Pena, Pamela Oliveira; Berto, Maria Isabel; Efraim, Priscilla
The high heat resistance of Salmonella in foods with low water activity raises particular issues for food safety, especially chocolate, where outbreak investigations indicate that few colony-forming units are necessary to cause salmonellosis. This study evaluated the efficiency of cocoa roasting and milk chocolate conching in the inactivation of Salmonella 5-strain suspension. Thermal resistance of Salmonella was greater in nibs compared to cocoa beans upon exposure at 110 to 130°C. The D-values in nibs were 1.8, 2.2 and 1.5-fold higher than those calculated for cocoa beans at 110, 120 and 130°C. There was no significant difference (p>0.05) between the matrices only at 140°C. Since in the conching of milk chocolate the inactivation curves showed rapid death in the first 180 min followed by a lower inactivation rate, and two D-values were calculated. For the first time interval (0-180 min) the D-values were 216.87, 102.27 and 50.99 min at 50, 60 and 70°C, respectively. The other D-values were determined from the second time interval (180-1440 min), 1076.76 min at 50°C, 481.94 min at 60°C and 702.23 min at 70°C. The results demonstrated that the type of matrix, the process temperature and the initial count influenced the Salmonella resistance.
Introduction: Salmonella enterica are a diverse group of bacteria that represent a serious risk to public health. Bacterial attachment on food and contact surfaces can lead to biofilm formation, and once in this state, bacteria are more resistant to sanitization and may serve as a continuous contam...
Among several potentials of nanotechnology applications for food industry, development of nanoscale sensors for food safety and quality measurement are emerging. A novel biosensor for Salmonella detection was developed using Au/Si/ nanorods. The Si nanorods were fabricated by glancing angle depositi...
A Salmonella Montevideo strain that is resistant to ampicillin and kanamycin and that expresses the green fluorescent protein (S Montevideo-GFP) was utilized to inoculate sterile and non-sterile cattle manure (1 x 105 CFU/gram manure) onto which sterilized horn fly embryos were placed and held for e...
Although hundreds of articles are written about Salmonella each year, it continues to command top billing as a food borne pathogen. We have revisited the same issues over a period of time without hitting upon a ‘eureka’ moment. Often, we tend to travel in the comfort zone, bringing in the latest ...
Contaminated fresh produce has become the number one vector of non-typhoidal salmonellosis to humans. However, Salmonella enterica genes essential for the life cycle of this organism outside the mammalian host are for the most part unknown. Screening deletion mutants led to the discovery that an aro...
Nastasi, A.; Mammina, C.; Cannova, L.
During 1990 to 1998, we identified multidrug-resistant isolates of Salmonella Enteritidis in southern Italy. Plasmids containing class I integrons and codifying for synthesis of extended- spectrum beta-lactamases were detected. Active surveillance for resistance to antimicrobial agents is needed to guard against the possible spread of resistant clones. PMID:10905977
O'Neill, Luke A J
Rao and colleagues (2017) reveal how Salmonella limits anorexia in mice, protecting them and promoting the spread of infection. The mechanism involves inhibition of the NLRP3 inflammasome limiting vagal nerve stimulation by IL-1β, which in turn promotes appetite. A possible new therapeutic approach for treating anorexia in multiple diseases is proposed.
Salmonella and Campylobacter are frequent colonizers of the intestinal tracts of poultry and have often been associated with human foodborne illness. The entry, transmission and prevalence of both pathogens have been extensively studied in chickens but little information is available for turkeys. ...
Wang, Cheng-Zhi; Kazmierczak, Robert A.; Eisenstark, Abraham
Recently, investigation of bacterial-based tumor therapy has regained focus due to progress in molecular, cellular, and microbial biology. Many bacteria such as Salmonella, Listeria, Escherichia, and Clostridium have proved to have tumor targeting and in some cases even tumor-destroying phenotypes. Furthermore, bacterial clinical treatments for cancer have been improved by combination with other therapeutic methods such as chemotherapeutic drugs and radioactive agents. Synthetic biology techniques have also driven the development of new bacterial-based cancer therapies. However, basic questions about the mechanisms of bacterial-mediated tumor targeting and destruction are still being elucidated. In this review, we focus on three tumor-therapeutic Salmonella models, the most intensively studied bacterial genus in this field. One of these Salmonella models is our Salmonella enterica serovar Typhimurium LT2 derived strain CRC2631, engineered to minimize toxicity but maximize tumor-targeting and destruction effects. The other two are VNP20009 and A1-R. We compare the means by which these therapeutic candidate strain models were selected for study, their tumor targeting and tumor destruction phenotypes in vitro and in vivo, and what is currently known about the mechanisms by which they target and destroy tumors. PMID:27190519
Tender cactus pads (cladodes) or nopalitos (Opuntia ficus-indica L) are an important vegetable in Mexico. They are often pre-trimmed, cut and packaged, and while usually consumed cooked, they may also be eaten raw in salads. Salmonella is an enteropathogenic bacterium that can adapt to adverse envir...
Lighting is used during broiler grow-out to modify bird behavior to reach the goals of production. The protocols for lighting intensity vary. In a field project, we evaluated if the lighting protocol impacts the burden of Salmonella in grow-out broiler flocks. Conventional grow-out flocks reared ...
Jehangir, Asad; Poudel, Dilli; Fareedy, Shoaib Bilal; Salman, Ahmed; Qureshi, Anam; Jehangir, Qasim; Alweis, Richard
A 62-year-old male with past medical history of benign prostatic hyperplasia presented to the emergency department with complaints of decreased urinary flow, inability to fully empty his bladder, and gross hematuria. Physical examination was unremarkable. Urinalysis revealed large amount of blood and more than 700 white blood cells suggesting a urinary tract infection. Urine culture grew group D Salmonella greater than 100,000 colony-forming units per mL. He was prescribed 6 weeks of trimethoprim/sulfamethoxazole and had resolution of symptoms. Retrospectively, he reported a 3-day history of watery diarrhea about a week prior to onset of urinary symptoms that was presumed to be the hematogenous source in this case. Urinary tract infection from nontyphoidal Salmonella (NTS) is rare and is usually associated with immunosuppression, chronic diseases, such as diabetes or structural abnormalities of the genitourinary tract. Genitourinary tract abnormalities previously reported in the literature that predispose to nontyphoidal Salmonella urinary tract infection include nephrolithiasis, chronic pyelonephritis, retrovesicular fistula, urethrorectal fistula, hydrocele, and post-TURP. We present an exceedingly uncommon case of 62-year-old male with group D Salmonella urinary tract infection predisposed by his history of benign prostatic hyperplasia.
This paper reports an amperometric biosensor for rapid and sensitive Salmonella Typhimurium detection in milk. The biosensor was assembled from the self-assembled monolayers technique on a gold surface. In this device, polyclonal antibodies were oriented by protein A. The biosensor structure was cha...
Le Hello, Simon; Brisabois, Anne; Accou-Demartin, Marie; Josse, Adeline; Marault, Muriel; Francart, Sylvie; Da Silva, Nathalie Jourdan; Weill, François-Xavier
We report a food-related outbreak of salmonellosis in humans caused by a nonmotile variant of Salmonella enterica serotype Typhimurium in France in 2009. This nonmotile variant had been circulating in laying hens but was not considered as Typhimurium and consequently escaped European poultry flock regulations.
... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... culture products are to be tested, 1 ml of tissue extract used as the source of cells or 1 ml of...
... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... culture products are to be tested, 1 ml of tissue extract used as the source of cells or 1 ml of...
The ubiquitin modification has various functions in the host innate immune system in response to the bacterial infection. To counteract the host immunity, Salmonella can specifically target ubiquitin pathways by its effector proteins. In this review, we describe the multiple facets of ubiquitin func...
Salmonella Enteritidis (SE) in contaminated eggs is a public health hazard which may cause hospitalization or death in the elderly, infants, and individuals with impaired immune systems. Prevention of SE infection of laying hens is an essential first step in reducing SE outbreaks in humans. Multiple...
Ramachandran, Girish; Boyd, Mary Adetinuke; MacSwords, Jennifer; Higginson, Ellen E.; Simon, Raphael; Galen, James E.; Pasetti, Marcela F.; Levine, Myron M.
Nontyphoidal Salmonella (NTS) invasive infections are an important cause of morbidity and mortality in sub-Saharan Africa. Several vaccines are in development to prevent these infections. We describe an NTS opsonophagocytic killing assay that uses HL-60 cells and baby rabbit complement to quantify functional antibodies elicited by candidate NTS vaccines. PMID:27030587
Ramachandran, Girish; Boyd, Mary Adetinuke; MacSwords, Jennifer; Higginson, Ellen E; Simon, Raphael; Galen, James E; Pasetti, Marcela F; Levine, Myron M; Tennant, Sharon M
Nontyphoidal Salmonella (NTS) invasive infections are an important cause of morbidity and mortality in sub-Saharan Africa. Several vaccines are in development to prevent these infections. We describe an NTS opsonophagocytic killing assay that uses HL-60 cells and baby rabbit complement to quantify functional antibodies elicited by candidate NTS vaccines.
Visible/NIR spectroscopy has the potential to determine key wavelengths for bile detection on droppings. These wavelengths can be used for further development with hyperspectral and/or multispectral imaging methods for real-time monitoring broilers infected by Salmonella. From the preliminary test ...
Briones, Víctor; Téllez, Sonia; Goyache, Joaquín; Ballesteros, Cristina; del Pilar Lanzarot, María; Domínguez, Lucas; Fernández-Garayzábal, José F
During the spring and summer of 2001, faeces from 166 wild reptiles (94 individuals) and amphibians (72 individuals) from 21 different species found in central Spain were examined for the presence of Salmonella. Thirty-nine reptiles (41.5%) yielded 48 Salmonella isolates, whereas all the amphibians examined were negative. Subspecies Salmonella enterica enterica (I) accounted for up to 50% of isolates. Fourteen isolates (29.2%) belonged to subspecies diarizonae (IIIb), six isolates (12.5%) to subspecies salamae (II), and four isolates (8.3%) to subspecies arizonae (IIIa). Twenty-seven different serotypes were identified. Serotypes Anatum (12.5%), Herzliya (8.3%), Abony, 18:l,v:z, 9,12:z29:1,5 and 38:z10:z53 (6.2%/each) were the most frequently isolated. A high percentage (39.6%) of isolates belonged to serotypes previously associated with environmental sources. Also, 37.5% of isolates belonged to serotypes which had been related to human cases of salmonellosis. From these data, it is concluded that wild reptiles, but apparently not amphibians, may represent an important reservoir of Salmonella in nature and have potential implications for public health.
The increase in the incidence of gastroenteritis outbreaks linked to the consumption of foods of plant origin has ignited public concern and scientific interest in understanding interactions of human enteric pathogens with plants. Enteric disease caused by non-typhoidal Salmonella is a major public ...
Poppe, C; Kolar, J J; Demczuk, W H; Harris, J E
A study was conducted to determine the antibiotic resistance and biochemical characteristics of 2690 Salmonella strains belonging to 52 serovars and isolated from environmental and feed samples from 270 turkey flocks in Canada. Resistance of the Salmonella strains to the aminoglycoside antibiotics varied widely; none of the strains were resistant to amikacin, 14.2% were resistant to neomycin, 25.8% were resistant to gentamicin, and 27.7% of the strains were resistant to kanamycin. Most strains (97.6%) were resistant to the aminocyclitol, spectinomycin. Regarding resistance to the beta-lactam antibiotics, 14.3% and 14.4% of the strains were resistant to ampicillin and carbenicillin, respectively, whereas only 5 (0.2%) of the strains were resistant to cephalothin. None of the strains were resistant to the fluoroquinolone ciprofloxacin or to polymyxin B. Resistance to chloramphenicol and nitrofurantoin was found in 2.4% and 7% of the strains, respectively. Only 1.7% of the strains were resistant to the trimethoprimsulfamethoxazole combination, whereas 58.1% were resistant to sulfisoxazole. Thirty-eight percent of the strains were resistant to tetracycline. Salmonella serovars differed markedly in their drug resistance profiles. Biochemical characterization of the Salmonella showed that the S. anatum, S. saintpaul and S. reading serovars could be divided into distinct biotypes. PMID:8548684
... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... culture products are to be tested, 1 ml of tissue extract used as the source of cells or 1 ml of...
Lindhardt, Charlotte; Schönenbrücher, Holger; Slaghuis, Jörg; Bubert, Andreas; Ossmer, Rolf; Junge, Benjamin; Berghof-Jäger, Kornelia
The foodproof Salmonella Detection Kit was previously validated in the Performance Tested Methods program for the detection of Salmonella species in a variety of foods, including milk powder, egg powder, coconut, cocoa powder, chicken breast, minced meat, sliced sausage, sausage, smoked fish, pasta, white pepper, cumin, dough, wet pet food, dry pet food, ice cream, watermelon, sliced cabbage, food dye, and milk chocolate. The method was shown to be equivalent to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) and the U.S. Department of Agriculture, Food Safety and Inspection Service's Microbiology Laboratory Guidebook reference culture procedures. In the first Emergency Response Validation (ERV) extension study, peanut butter was inoculated with S. enterica. ser Typhimurium. For the low inoculation level (1.08 CFU/25 g), a Chi-square value of 2.25 indicated that there was no significant performance difference between the foodproof Salmonella Detection Kit and the FDA-BAM reference method. For high-level inoculation (11.5 CFU/25 g) and uninoculated control, there was 100% agreement between the methods. In the second ERV extension study, peanut butter was inoculated with S. enterica. ser Typhimurium. For both inoculation levels (0.1 and 0.5 CFU/25 g by most probable number), Chi-square values of 0 indicated that there was no significant performance difference between foodproof Salmonella Detection Kit and the FDA-BAM reference method.
Veljanov, D; Kussovski, V; Radoucheva, T; Najdenski, H; Ilieva, L; Cherepova, N; Voivodov, K; Genov, N
The influence of haematoporphyrin and proflavine on the virulence, survivability, respiratory activity and cell wall ultrastructure of Salmonella dublin cells was studied. There was a decrease in all biological properties investigated, especially when haematoporphyrin was used for dark incubation in comparison with proflavine. The possible clinical use of negatively charged photosensitizers is discussed.
Salmonella enterica subspecies enterica (S. enterica ssp. I) contains almost all the major pathogens in this genus. We sequenced 354 new S. enterica ssp. I genomes using paired end 100 base reads to ~80-fold coverage. These genomes were chosen to maximize genetic diversity, representing at least 100...
We sequenced and assembled 354 new Salmonella enterica ssp. enterica genomes. These genomes were chosen to maximize genetic diversity, representing at least 100 different serovars and distinct PFGE patterns within these serovars. 119 of the strains were of known antibiotic resistance,...
Abdel-Daim, Amira; Hassouna, Nadia; Hafez, Mohamed; Ashor, Mohamed Seif Aldeen; Aboulwafa, Mohammad M.
Background. Enteric fever is a global health problem, and rapidly developing resistance to various drugs makes the situation more alarming. The potential use of Lactobacillus to control typhoid fever represents a promising approach, as it may exert protective actions through various mechanisms. Methods. In this study, the probiotic potential and antagonistic activities of 32 Lactobacillus isolates against Salmonella typhi were evaluated. The antimicrobial activity of cell free supernatants of Lactobacillus isolates, interference of Lactobacillus isolates with the Salmonella adherence and invasion, cytoprotective effect of Lactobacillus isolates, and possibility of concurrent use of tested Lactobacillus isolates and antibiotics were evaluated by testing their susceptibilities to antimicrobial agents, and their oxygen tolerance was also examined. Results. The results revealed that twelve Lactobacillus isolates could protect against Salmonella typhi infection through interference with both its growth and its virulence properties, such as adherence, invasion, and cytotoxicity. These Lactobacillus isolates exhibited MIC values for ciprofloxacin higher than those of Salmonella typhi and oxygen tolerance and were identified as Lactobacillus plantarum. Conclusion. The tested Lactobacillus plantarum isolates can be introduced as potential novel candidates that have to be subjected for in vivo and application studies for treatment and control of typhoid fever. PMID:24191248
A six-year field study was conducted in the two major wild, or lowbush, blueberry growing regions in Maine, Midcoast and Downeast. This study used data from two cropping cycles (four years) to model the dynamics of Salmonella spp. prevalence in wild blueberry fields (Vaccinium angustifolium Aiton). ...
This study assessed the ability of Salmonella (572 isolates) to subsist on 12 different antibiotics. The majority (11/12) of the antibiotics provided subsistence to at least one of 140 isolates while 40 of these isolates displayed the ability to subsist on more than one antibiotic. This is the fir...
We set out to investigate whether Salmonella enterica could be recovered from various tissues of viable neonatal calves immediately following parturition. Eleven samples were aseptically collected from each of 20 calves and consisted of both left and right subiliac and prescapular lymph nodes (LN),...
Becker, William A.; Popkin, Rodger
Details events of six days during Salmonella outbreak at camp in North Carolina. Explains how camp handled 280 sick campers and staff, well campers, news media, and parents. Based on an epidemiologic survey of food eaten, it was suspected that the culprit of the outbreak was a meat item. Offers suggestions for crisis management in the camp…
Waterman, Stephen H.; And Others
Conducted a case-control study to determine the magnitude of the problem of Latino patients who ingested rattlesnake capsules and then developed serious "Salmonella arizona" infections. Eighty-two percent of infected Latinos in 1986-87 who were questioned reported ingesting snake capsules. Discusses the association of ingesting snake…
Agron, Peter G.; Andersen, Gary L.; Walker, Richard L.
Described herein is the identification of a novel Salmonella enterica serovar Enteritidis locus that serves as a marker for DNA-based identification of this bacterium. In addition, three primer pairs derived from this locus that may be used in a nucleotide detection method to detect the presence of the bacterium are also disclosed herein.
Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to an...
... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS...
Sánchez-Guerrero, J; Alarcón-Segovia, D
Despite the high frequency of both pericardial involvement and of infectious complications in SLE, septic pericarditis is uncommon. We report here a patient with SLE who developed tamponade due to Salmonella infection. Most of the other eight recorded cases of septic pericarditis in SLE were due to Staphylococcus aureus and none has been previously attributed to Gram-negative bacteria.
Johnston, Roger G.; Sinha, Dipen N.
Measurement of the acoustical resonances in eggs is shown to provide a rapid, noninvasive technique for establishing the presence of Salmonella bacteria. The technique is also sensitive to yolk puncture, shell cracks, and may be sensitive to other yolk properties and to egg freshness. Remote characterization, potentially useful for characterizing large numbers of eggs, has been demonstrated.
Hao, Haihong; Pan, Huafang; Ahmad, Ijaz; Cheng, Guyue; Wang, Yulian; Dai, Menghong; Tao, Yanfei; Chen, Dongmei; Peng, Dapeng; Liu, Zhenli; Huang, Lingli; Yuan, Zonghui
Susceptibility breakpoints are crucial for prudent use of antimicrobials. This study has developed the first susceptibility breakpoint (MIC ≤ 0.25 μg/ml) for enrofloxacin against swine Salmonella spp. based on wild-type cutoff (COWT) and pharmacokinetic-pharmacodynamic (PK-PD) cutoff (COPD) values, consequently providing a criterion for susceptibility testing and clinical usage of enrofloxacin.
Parsons, Sandra K.; Bull, C. Michael; Gordon, David M.
Multilocus sequence typing of 56 Salmonella enterica subsp. enterica strains isolated from Australian wildlife hosts was performed. The results of population assignment algorithms revealed that the 56 strains could be subdivided into two distinct clades. Strains belonging to the two clades were further distinguished phenotypically, genotypically, and with respect to host distribution. PMID:21378038
Salmonella enterica is the leading cause of food-borne bacterial infection in humans and has a high economic burden in agriculture. Strains differ by sequence additions and losses of up to ~10% of each genome. In the last few decades, some serovars have become more common. Many strains have acquired...
Poharkar, Krupali V; Kerkar, Savita; D'Costa, Dilecta; Doijad, Swapnil; Barbuddhe, S B
Mangroves are affected by industrial and anthropogenic factors. Although mangroves have been widely studied, investigations of pathogens that may affect public health significance are largely lacking even while incidences of diseases linked with the consumption of mangrove-associated food have increased. A total of 150 samples of water, sediment, and biota were collected from ten mangrove ecosystems in Goa, India. Total viable counts of pathogens such as E. coli, Listeria, Salmonella, and Vibrio spp. ranged from 1.25 to 3.9 × 10(3) cfu/ mL, which were above the relevant standards. Salmonella counts were the highest at 3.1 to 3.9 × 10(3)cfu/mL, with a prevalence of 40%. Considering its high prevalence, the virulence of Salmonella spp. was studied. The invA gene was detected in 35% of the Salmonella isolates by polymerase chain reaction (PCR). The findings suggested that pathogens adapt to this habitat, resulting in contamination of the indigenous fauna.
An automated approach to bacterial mutagenicity testing--the spiral Salmonella assay--was developed to simplify testing and to reduce the labor and materials required to generate dose-responsive mutagenicity information. This document provides the reader with an ...
Salmonella populations in soil were reduced by up to 5 log CFU/ml after 28 days of incubation using vinegar or eugenol. The bactericidal effect of Cinnamanaldehyde was not evident. S. negev was sensitive to oils resulting in significant reduction of this bacterium. Increase in oil concentration resu...
Souza, Roberta B.; Ferrari, Rafaela G.; Magnani, Marciane; Kottwitz, Luciana B. M.; Alcocer, Iliana; Tognim, Maria Cristina B.; Oliveira, Tereza C. R. M.
The antimicrobial susceptibility of 212 Salmonella strains isolated from patients and foods was evaluated and 45% were found to be resistant to nalidixic acid. Nalidixic acid resistant strains showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive strains. During the study an increase of strains with reduced susceptibility to ciprofloxacin was also observed. PMID:24031522
McSorley, Stephen J.
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
Bapanpally, Chandra; Montier, Laura; Khan, Shah; Kasra, Akif; Brunelle, Sharon L
The SAS Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6-7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16-20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli 0157. Thus, after a short 6-7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non-Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied.
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
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
Davies, R; Breslin, M; Corry, J E; Hudson, W; Allen, V M
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.
Michael, G B; Schwarz, S
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.
Very, K J; Kirchner, M K; Shariat, N; Cottrell, W; Sandt, C H; Dudley, E G; Kariyawasam, S; Jayarao, B M
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.
Sivapalasingam, S; Hoekstra, R M; McQuiston, J R; Fields, P I; Tauxe, R V
Salmonellosis is a major cause of gastroenteritis in the United States and can lead to septicaemia, and other extra-intestinal illness including urinary tract infections (UTIs). To examine trends in Salmonella bacteriuria in the United States, surveillance data from the National Salmonella Surveillance System from 1980 to the end of 1999 were reviewed. Overall, 17442 urinary Salmonella isolates were reported, representing 2% of all Salmonella isolates from a known source. This proportion increased from 2% during 1980--1984 to 4% during 1995--1999. The median age of persons from whom these isolates came was 51 years; 12,176 (70 %) were women. Compared to the last national survey conducted between 1968 and 1979, the rate of Salmonella bacteriuria increased among women, from 2.0 per million persons in 1980 to 3.7 in 1999; the highest rate occurring in women > or = 70 years. National reporting of Salmonella bacteriuria increased in absolute incidence and as a proportion of all Salmonella, especially in elderly women and may represent an increase in the incidence of Salmonella UTIs. Better understanding of the uropathogenicity of Salmonella serotypes may further clarify the mechanisms of Salmonella UTIs.
Wells, S J; Fedorka-Cray, P J; Dargatz, D A; Ferris, K; Green, A
As part of a national study of the U.S. dairy cow population, fecal samples were collected from representative cows on 91 dairies and 97 cull dairy cow markets in 19 states. Salmonella spp. were recovered from 5.4% of milk cows, 18.1% of milk cows expected to be culled within 7 days, and 14.9% of culled dairy cows at markets. On a premise basis, Salmonella shedding in milk cows was detected on 21.1% of dairies and 66% of cull dairy cow markets. The percentage of herds with at least one cow with detectable Salmonella fecal shedding was higher during the sampling period from May through July, in herds with at least 100 milk cows, and in herds in the South region. The most common Salmonella serogroups isolated were E (30.8% of isolates) and C1 (28.6%); the most common serotypes isolated were Salmonella Montevideo (21.5% of isolates), Salmonella Cerro (13.3%), and Salmonella Kentucky (8.5%). Fecal shedding of Salmonella Typhimurium or Salmonella Typhimurium var. copenhagen was infrequent (2.8% of isolates). Most isolates (88.9%) were susceptible to all 17 antimicrobials evaluated; multiple resistance was an infrequent occurrence. This study provides information describing the distribution of Salmonella fecal shedding from dairy cows on farm and at markets and will serve as a baseline for future studies.