Assessment of exposure to Leptospira serovars in veterinary staff and dog owners in contact with infected dogs.

Science.gov (United States)

Barmettler, Reto; Schweighauser, Ariane; Bigler, Susanne; Grooters, Amy M; Francey, Thierry

2011-01-15

To assess patterns of seroreactivity to Leptospira serovars in veterinary professional staff and dog owners exposed to dogs with acute leptospirosis and to contrast these patterns in people with those observed in dogs. Cross-sectional study. Human subjects consisted of 91 people (50 veterinarians, 19 technical staff, 9 administrative personnel, and 13 dog owners) exposed to dogs with leptospirosis. Canine subjects consisted of 52 dogs with naturally occurring leptospirosis admitted to the University of Bern Vetsuisse Faculty Small Animal Clinic in 2007 and 2008. People were tested for seroreactivity to regionally prevalent Leptospira serovars by use of a complement fixation test. A questionnaire designed to identify risk factors associated with seropositivity was used to collect demographic information from each study participant. Dogs were tested for seroreactivity to Leptospira serovars by use of a microscopic agglutination test. On the basis of microscopic agglutination test results, infected dogs were seropositive for antibodies against Leptospira serovars as follows (in descending order): Bratislava (43/52 [83%]), Australis (43/52 [83%]), Grippotyphosa (18/52 [35%]), Pomona (12/52 [23%]), Autumnalis (6/52 [12%]), Icterohemorrhagiae (4/52 [8%]), Tarassovi (2/52 [4%]), and Canicola (1/52 [2%]). All 91 people were seronegative for antibodies against Leptospira serovars. Therefore, statistical evaluation of risk factors and comparison of patterns of seroreactivity to Leptospira serovars between human and canine subjects were limited to theoretical risks. Seroreactivity to Leptospira serovars among veterinary staff adhering to standard hygiene protocols and pet owners exposed to dogs with acute leptospirosis was uncommon.

First isolation of Salmonella enterica serovar Napoli from wild birds in Italy

Directory of Open Access Journals (Sweden)

Laura Mancini

2014-03-01

Full Text Available Salmonella enterica serovar Napoli (S. Napoli is an emerging serovar in Italy. It accounts for 2-4% of all serovars isolated from human infections. The zoonotic origin of this serovar is still unknown and this makes difficult to apply any control intervention. We report here the isolation of S. Napoli from a river nightingale (Cettia cetti, Temminck 1820 which represents the first description of this serovar from wild birds. This finding adds knowledge to the ecology of S. Napoli and addresses further studies aimed to assess the epidemiologic link between S. Napoli isolated from wild birds, food, environmental sources and human infections.

Risk factors associated with Salmonella enterica serovar typhimurium infection in Danish broiler flocks

DEFF Research Database (Denmark)

Skov, M. N.; Angen, Øystein; Chriel, M.

1999-01-01

A retrospective longitudinal study was conducted to identify risk factors associated with Salmonella enterica serovar typhimurium (S. typhimurium) infection in Danish broiler flocks. The data included all broiler flocks slaughtered in 1995, and the epidemiological unit was the individual broiler...... flock. The S. typhimurium status was determined by microbiological examination of 60 fresh fecal samples. This procedure should detect an infected flock with a probability above 95%, if the prevalence is above 5%, and given that the sensitivity of the test is 100%. Nineteen variables were selected...... for analysis. Five factors and an interaction term were found significant by multivariate logistic regression analysis. An increased risk for S, typhimurium infection was associated with two parent flocks, one confirmed infected and one suspected of being infected with S. typhimurium, with two...

Serovars of Mycobacterium avium Complex isolated from patients in Denmark

DEFF Research Database (Denmark)

Askgaard, D. S.; Giese, Steen Bjørck; Thybo, S.

1994-01-01

Danish isolates of Mycobacterium avium complex were serotyped by the use of seroagglutination. The most prevalent serovars among patients with AIDS (n = 89) were 4 and 6, while among non-AIDS patients the most prevalent serovars were 1, 6, and 4, with no major differences between those in patients...... with pulmonary disease (n = 65) and those in patients with lymph node infection (n = 58). The results suggest a Scandinavian distribution of serovars with a predominance of serovar 6 and fail to demonstrate any selective protection against different serovars by Mycobacterium bovis ECG vaccination....

Experimental infection of laying hens with Salmonella enterica serovar Gallinarum Infecção experimental com Salmonella enterica serovar Gallinarum em poedeiras comerciais

Directory of Open Access Journals (Sweden)

Gláucia Helaine de Oliveira

2005-03-01

Full Text Available Experimental infections were set up in commercial laying birds, comprising a white relatively resistant line and a red susceptible line infecting with Salmonella enterica serovar Gallinarum. The major findings were that in susceptible birds clinical disease occurred in a dose-dependent manner. Faecal excretion occurred in susceptible birds almost up to death but also occurred in the more resistant line and in birds, which were convalescing. Removal of birds, which had died from the disease, from the environment, reduced the resultant mortality/morbidity and may be regarded as a useful measure for control.Infecções experimentais por Salmonella enterica serovar Gallinarum foram realizadas em aves de postura comercial, incluindo uma linhagem branca resistente e uma linhagem vermelha susceptível ao desenvolvimento da enfermidade clínica. As aves de linhagem susceptível apresentaram doença clínica dependente da dose administrada. Excreção fecal foi observada em aves da linhagem susceptível próximo ao momento da morte e, eventualmente, em aves da linhagem resistente e aves convalescentes. A remoção das aves mortas do meio ambiente reduziu a taxa de mortalidade/morbidade, procedimento este que pode ser utilizado como medida de controle.

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

Science.gov (United States)

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

2011-08-01

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

Comparative genomics of pathogenic Leptospira interrogans serovar Canicola isolated from swine and human in Brazil

Directory of Open Access Journals (Sweden)

Luisa Z Moreno

Full Text Available Leptospira interrogans serovar Canicola is one of the most important pathogenic serovars for the maintenance of urban leptospirosis. Even though it is considered highly adapted to dogs, serovar Canicola infection has already been described in other animals and even a few human cases. Here, we present the genomic characterisation of two Brazilian L. interrogans serovar Canicola strains isolated from slaughtered sows (L0-3 and L0-4 and their comparison with human strain Fiocruz LV133. It was observed that the porcine serovar Canicola strains present the genetic machinery to cause human infection and, therefore, represent a higher risk to public health. Both human and porcine serovar Canicola isolates also presented sequences with high identity to the Chinese serovar Canicola published plasmids pGui1 and pGui2. The plasmids identification in the Brazilian and Chinese serovar Canicola strains suggest that extra-chromosomal elements are one more feature of this serovar that was previously unnoticed.

The emergence of Leptospira borgpetersenii serovar Arborea in Queensland, Australia, 2001 to 2013.

Science.gov (United States)

Lau, Colleen L; Skelly, Chris; Dohnt, Michael; Smythe, Lee D

2015-06-14

Leptospirosis is an emerging infectious disease, with increasing frequency and severity of outbreaks, changing epidemiology of populations at risk, and the emergence of new serovars. Environmental drivers of disease transmission include flooding, urbanisation, poor sanitation, changes in land use and agricultural practices, and socioeconomic factors. In Queensland, human infection with Leptosira borgpetersenii serovar Arborea was first reported in 2001. This study aims to report the emergence of serovar Arborea in Queensland from 2001 to 2013, and investigate potential risk factors for infection and drivers of emergence. Data on laboratory-confirmed cases of human leptospirosis in Queensland were obtained from the enhanced surveillance system at the WHO/FAO/OIE Collaborating Centre for Reference and Research on Leptospirosis in Brisbane, Australia. The changing epidemiology of serovar Arborea from 2001 to 2003 was described with respect to case numbers, proportion of leptospirosis cases attributed to the serovar, and geographic distribution. Differences in risk factors for the most common serovars were compared. During this period, 1289 cases of leptospirosis were reported, including 233 cases attributed to serovar Arborea. Risk factors for infection include male gender (91 % of cases), occupation, and recreational exposure. Most common occupations recorded were banana workers (28.4 %), meat workers (7.2 %), dairy farmers (5.8 %), graziers/stockmen (5.5 %), 'other agricultural/rural workers' (16.4 %), and tourists or tourism operators (4.6 %). Time trend analysis showed that while non-Arborea cases decreased over the study period, Arborea cases increased by 3.4 cases per year. The proportion of annual cases attributed to Arborea peaked at 49 % in 2011 after unprecedented flooding in Queensland. Mapping of cases by residential location showed expansion of the geographic range of serovar Arborea, concentrating mostly around Brisbane, Cairns and Innisfail. Serovars

Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

KAUST Repository

An, Ran; Lin, Pengpeng; Bougouffa, Salim; Essack, Magbubah; Boxrud, David; Bajic, Vladimir B.; Vidovic, Sinisa

2018-01-01

Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

Draft Genome Sequences of Four Salmonella enterica subsp. enterica Serovar Enteritidis Strains Implicated in Infections of Avian and Human Hosts

KAUST Repository

An, Ran

2018-01-24

Salmonella enterica subsp. enterica serovar Enteritidis is a wide-host-range pathogen. Occasionally, it is involved in invasive infections, leading to a high mortality rate. Here, we present the draft genome sequences of four S Enteritidis strains obtained from human and avian hosts that had been involved in bacteremia, gastroenteritis, and primary infections.

Multilocus sequence typing as a replacement for serotyping in Salmonella enterica.

Directory of Open Access Journals (Sweden)

Mark Achtman

Full Text Available Salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. We used Multilocus Sequence Typing (MLST to assign 4,257 isolates from 554 serovars to 1092 sequence types (STs. The majority of the isolates and many STs were grouped into 138 genetically closely related clusters called eBurstGroups (eBGs. Many eBGs correspond to a serovar, for example most Typhimurium are in eBG1 and most Enteritidis are in eBG4, but many eBGs contained more than one serovar. Furthermore, most serovars were polyphyletic and are distributed across multiple unrelated eBGs. Thus, serovar designations confounded genetically unrelated isolates and failed to recognize natural evolutionary groupings. An inability of serotyping to correctly group isolates was most apparent for Paratyphi B and its variant Java. Most Paratyphi B were included within a sub-cluster of STs belonging to eBG5, which also encompasses a separate sub-cluster of Java STs. However, diphasic Java variants were also found in two other eBGs and monophasic Java variants were in four other eBGs or STs, one of which is in subspecies salamae and a second of which includes isolates assigned to Enteritidis, Dublin and monophasic Paratyphi B. Similarly, Choleraesuis was found in eBG6 and is closely related to Paratyphi C, which is in eBG20. However, Choleraesuis var. Decatur consists of isolates from seven other, unrelated eBGs or STs. The serological assignment of these Decatur isolates to Choleraesuis likely reflects lateral gene transfer of flagellar genes between unrelated bacteria plus purifying selection. By confounding multiple evolutionary groups, serotyping can be misleading about the disease potential of S. enterica. Unlike serotyping, MLST recognizes evolutionary groupings and we recommend that Salmonella classification by serotyping should be replaced by MLST or its equivalents.

Determination of Leptospira borgpetersenii serovar Javanica and Leptospira interrogans serovar Bataviae as the persistent Leptospira serovars circulating in the urban rat populations in Peninsular Malaysia.

Science.gov (United States)

Benacer, Douadi; Mohd Zain, Siti Nursheena; Sim, Shin Zhu; Mohd Khalid, Mohd Khairul Nizam; Galloway, Renee L; Souris, Marc; Thong, Kwai Lin

2016-03-01

Leptospirosis is an emerging infectious disease of global significance, and is endemic in tropical countries, including Malaysia. Over the last decade, a dramatic increase of human cases was reported; however, information on the primary vector, the rat, and the Leptospira serovars circulating among the rat population is limited. Therefore, the present study was undertaken to isolate Leptospira and characterise the serovars circulating in the urban rat populations from selected main cities in Peninsular Malaysia. Rat trappings were carried out between October 2011 to February 2014 in five urban cities which were chosen as study sites to represent different geographical locations in Peninsular Malaysia. Microscopic agglutination test (MAT) and PCR were carried out to identify the Leptospiral serogroup and determine the pathogenic status of the isolates, respectively while pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD)-PCR were used to characterize the isolates. Three rat species were identified from the three hundred and fifty seven rats captured with Rattus rattus, being the dominant rat species (285, 80 %) followed by Rattus norgevicus (53, 15 %) and Rattus exulans (19, 5 %). Only 39 samples (11.0 %) were positive by culture and further confirmed as pathogenic Leptospira by PCR. Significant associations were shown between host infection with locality, season, host-age and species. Based on MAT, two serogroups were identified in the population namely; L. borgpetersenii serogroup Javanica (n = 16) and L. interrogans serogroup Bataviae (n = 23). Pulsed-field gel electrophoresis (PFGE) distinguished the two serovars in the urban rat populations: L. borgpetersenii serovar Javanica (41 %), and L. interrogans serovar Bataviae (59 %). RAPD-PCR yielded 14 distinct patterns and was found to be more discriminative than PFGE. This study confirms two Leptospira serovars circulating among the urban rats population in Peninsular

Salmonella enterica serovars Typhimurium and Enteritidis causing mixed infections in febrile children in Mozambique

Directory of Open Access Journals (Sweden)

García V

2018-01-01

multidrug-resistant isolates of S. Enteritidis. Nearly half of the children were coinfected with both serovars, a fact expected to aggravate the disease and hamper the treatment. However, particularly poor outcomes were not observed for the coinfected patients. Conclusion: Mixed Salmonella infections could frequently occur in febrile children in Mozambique. Additional studies are required to determine their actual impact and consequences, not only in this country, but also in other African countries. Keywords: invasive nontyphoidal salmonellosis, bloodstream infection, multidrug resistance, virulence-resistance plasmid, ST313, ST1479

ORF Alignment: NC_002935 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... subsp. enterica serovar Choleraesuis] emb|CAB92434.1| ... sulfonamides resistance determin...ef|NP_863000.1| Sul1 [Escherichia coli] gb|AAD22147.1| ... sulfonamides resistance determinant [Enter

ORF Alignment: NC_006856 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... subsp. enterica serovar Choleraesuis] emb|CAB92434.1| ... sulfonamides resistance determin...ef|NP_863000.1| Sul1 [Escherichia coli] gb|AAD22147.1| ... sulfonamides resistance determinant [Enter

ORF Sequence: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available of cations and cationic drugs [Salmonella enterica subsp. enterica serovar Choleraesuis str. SC-B67] MFYWILL... NC_006905 gi|62180070 >gi|62180070|ref|YP_216487.1| putative membrane transporter

ORF Sequence: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available of cations and cationic drugs [Salmonella enterica subsp. enterica serovar Choleraesuis str. SC-B67] MQQFEWI... NC_006905 gi|62180071 >gi|62180071|ref|YP_216488.1| putative membrane transporter

ORF Alignment: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... involved in its turnover [Salmonella enterica subsp. ... enterica serovar Choleraesuis str.... ... division and FtsZ ring formation upon DNA ... damage/inhibition, HslVU and Lon involved in its ... turnover

Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection.

Science.gov (United States)

Iriarte, Andrés; Giner-Lamia, Joaquín; Silva, Claudia; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J; Ochoa, Theresa; García, Coralith; Puente, José L; Chabalgoity, José A; García-Del Portillo, Francisco

2017-07-20

We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. Copyright © 2017 Iriarte et al.

Identification by PCR of non-typhoidal Salmonella enterica serovars associated with invasive infections among febrile patients in Mali.

Directory of Open Access Journals (Sweden)

Sharon M Tennant

2010-03-01

Full Text Available 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.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,[5],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.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,[5],12:i:- strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,[5],12:i:- strains.We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries.

ORF Alignment: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006905 gi|62179485 >1iwlA 1 182 23 204 2e-69 ... ref|YP_215902.1| periplasmic protein effects...ica ... subsp. enterica serovar Choleraesuis str. SC-B67] ... gb|AAX64821.1| periplasmic protein effects

ORF Alignment: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006905 gi|62180303 >1u07A 2 90 193 281 2e-32 ... ref|YP_216720.1| energy transduce...terica ... serovar Choleraesuis str. SC-B67] gb|AAX65639.1| energy ... transducer; uptake of i

ORF Alignment: NC_006511 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006511 gi|56413338 >1u07A 2 90 193 281 2e-32 ... ref|YP_216720.1| energy transduce...terica ... serovar Choleraesuis str. SC-B67] gb|AAX65639.1| energy ... transducer; uptake of i

ORF Alignment: NC_003197 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_003197 gi|16765081 >1u07A 2 90 193 281 2e-32 ... ref|YP_216720.1| energy transduce...terica ... serovar Choleraesuis str. SC-B67] gb|AAX65639.1| energy ... transducer; uptake of i

Human migration is important in the international spread of exotic Salmonella serovars in animal and human populations.

Science.gov (United States)

Iveson, J B; Bradshaw, S D; How, R A; Smith, D W

2014-11-01

The exposure of indigenous humans and native fauna in Australia and the Wallacea zoogeographical region of Indonesia to exotic Salmonella serovars commenced during the colonial period and has accelerated with urbanization and international travel. In this study, the distribution and prevalence of exotic Salmonella serovars are mapped to assess the extent to which introduced infections are invading native wildlife in areas of high natural biodiversity under threat from expanding human activity. The major exotic Salmonella serovars, Bovismorbificans, Derby, Javiana, Newport, Panama, Saintpaul and Typhimurium, isolated from wildlife on populated coastal islands in southern temperate areas of Western Australia, were mostly absent from reptiles and native mammals in less populated tropical areas of the state. They were also not recorded on the uninhabited Mitchell Plateau or islands of the Bonaparte Archipelago, adjacent to south-eastern Indonesia. Exotic serovars were, however, isolated in wildlife on 14/17 islands sampled in the Wallacea region of Indonesia and several islands off the west coast of Perth. Increases in international tourism, involving islands such as Bali, have resulted in the isolation of a high proportion of exotic serovar infections suggesting that densely populated island resorts in the Asian region are acting as staging posts for the interchange of Salmonella infections between tropical and temperate regions.

Changes in the prevalence of Salmonella serovars associated swine production and correlations of avian, bovine and swine-associated serovars with human-associated serovars in the United States (1997-2015).

Science.gov (United States)

Yuan, C; Krull, A; Wang, C; Erdman, M; Fedorka-Cray, P J; Logue, C M; O'Connor, A M

2018-04-23

As Salmonella enterica is an important pathogen of food animals, surveillance programmes for S. enterica serovars have existed for many years in the United States. Surveillance programmes serve many purposes, one of which is to evaluate alterations in the prevalence of serovars that may signal changes in the ecology of the target organism. The primary aim of this study was to evaluate changes in the proportion of S. enterica serovars isolated from swine over a near 20-year observation period (1997-2015) using four longitudinal data sets from different food animal species. The secondary aim was to evaluate correlations between changes in S. enterica serovars frequently recovered from food animals and changes in S. enterica serovars associated with disease in humans. We found decreasing proportions of S. enterica serovar Typhimurium, serovar Derby and serovar Heidelberg and increasing proportions of S. enterica serovar 4,[5],12:i:-, serovar Infantis and serovar Johannesburg in swine over time. We also found positive correlations for the yearly changes in S. enterica serovar 4,[5],12:i:-, serovar Anatum and serovar Johannesburg between swine and human data; in S. enterica Worthington between avian and human data; and in S. enterica serovar 4,[5],12:i:- between bovine and human data. We found negative correlations for the yearly changes in S. enterica serovar 4,[5],12:i:- and serovar Johannesburg between avian and human data. © 2018 Blackwell Verlag GmbH.

Molecular and cellular characterization of a Salmonella enterica serovar Paratyphi a outbreak strain and the human immune response to infection.

Science.gov (United States)

Gal-Mor, Ohad; Suez, Jotham; Elhadad, Dana; Porwollik, Steffen; Leshem, Eyal; Valinsky, Lea; McClelland, Michael; Schwartz, Eliezer; Rahav, Galia

2012-02-01

Enteric fever is an invasive life-threatening systemic disease caused by the Salmonella enterica human-adapted serovars Typhi and Paratyphi. Increasing incidence of infections with Salmonella enterica serovar Paratyphi A and the spreading of its antibiotic-resistant derivates pose a significant health concern in some areas of the world. Herein, we describe a molecular and phenotypic characterization of an S. Paratyphi A strain accounted for a recent paratyphoid outbreak in Nepal that affected at least 37 travelers. Pulsed-field gel electrophoresis analysis of the outbreak isolates revealed one genetic clone (pulsotype), confirming a single infecting source. Genetic profiling of the outbreak strain demonstrated the contribution of specific bacteriophages as a prime source of genetic diversity among clinical isolates of S. Paratyphi A. Phenotypic characterization in comparison with the S. Paratyphi A ATCC 9150 reference sequenced strain showed differences in flagellar morphology and increased abilities of the outbreak strain with respect to its motility, invasion into nonphagocytic cells, intracellular multiplication, survival within macrophages, and higher induction of interleukin-8 (IL-8) secreted by host cells. Collectively, these differences suggest an enhanced virulence potential of this strain and demonstrate an interesting phenotypic variation among S. Paratyphi A isolates. In vivo profiling of 16 inflammatory cytokines in patients infected with the outbreak strain revealed a common profile of a remarkable gamma interferon (IFN-γ) induction together with elevated concentrations of tumor necrosis factor alpha (TNF-α), IL-6, IL-8, IL-10, and IL-15, but not IL-12, which was previously demonstrated as elevated in nontyphoidal Salmonella infections. This apparent profile implies a distinct immune response to paratyphoid infections.

Ureaplasma parvum serovar 3 multiple banded antigen size variation after chronic intra-amniotic infection/colonization.

Science.gov (United States)

Robinson, James W; Dando, Samantha J; Nitsos, Ilias; Newnham, John; Polglase, Graeme R; Kallapur, Suhas G; Pillow, J Jane; Kramer, Boris W; Jobe, Alan H; Payton, Diane; Knox, Christine L

2013-01-01

Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA), a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic) and short term (acute) durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2 × 10(7) colony-forming-units (CFU) of U. parvum serovar 3 (Up) or media controls (C) were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4); day 117 (7d Up, n = 8; C7, n = 2); and day 121 (3d Up, n = 8; C3, n = 2) of gestation (term = 145-150d). At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i) snap frozen for subsequent ureaplasma culture, and (ii) fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up) or very few MBA variants (7d Up) were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion), during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation.

Ureaplasma parvum serovar 3 multiple banded antigen size variation after chronic intra-amniotic infection/colonization.

Directory of Open Access Journals (Sweden)

James W Robinson

Full Text Available Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA, a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic and short term (acute durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2 × 10(7 colony-forming-units (CFU of U. parvum serovar 3 (Up or media controls (C were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4; day 117 (7d Up, n = 8; C7, n = 2; and day 121 (3d Up, n = 8; C3, n = 2 of gestation (term = 145-150d. At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i snap frozen for subsequent ureaplasma culture, and (ii fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up or very few MBA variants (7d Up were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion, during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation.

[Immunogenicity of attenuated Salmonella choleraesuis vaccine strain expressing immunogenic genes of Mycoplasma hyopneumoniae in mice].

Science.gov (United States)

Ma, Fengying; Zou, Haoyong; He, Qigai

2011-09-01

The study was carried out to construct and characterize Salmonella choleraesuis vaccine strain expressing immunogenic genes of Mycoplasma hyopneumoniae and to test its immunogenicity in mice. We made p36, p46, p65 and p97R1-Nrdf, the main immunogenic genes of Mycoplasma hyopneumoniae, to insert into the prokaryotic expression plasmid pYA3493. Then these recombinant plasmids and pYA3493 were electroporated into C500 asd-mutant, resulting in the recombinant Salmonella choleraesuis vaccine strains C36 (pYA-36), C46 (pYA-46), C65 (pYA-65), C97R1-Nrdf(pYA-97R1-Nrdf) and CpYA(pYA3493). We characterized these recombinant Salmonella choleraesuis vaccine strains and tested the immunogenicity in mice by intramuscular injection or orally immunized. The results of the immunogenicity in mice indicated that the group orally immunized with C36, C46, C65, C97R1-Nrdf showed significantly higher Mycoplasma pneumoniae antibody than both the group orally immunized with C36, C46, C65 and the group intramuscular injected with the Mycoplasma hyopneumoniae bacterin (M + PAC) (P Mycoplasma hyopneumoniae bacterin (M + PAC) (P 0.05). The highest level of IL-4 was found in the group orally immunized with C36, C46, C65; higher levels of IL-4 was observed in the group orally immunized with C36, C46, C65, C97R1-Nrdf than the group injected with the Mycoplasma hyopneumoniae bacterin (M + PAC); and the lowest IL-4 level was found in the group injected with C36, C46, C65. There were no significant differences among them (P > 0.05). The Mycoplasma pneumoniae antibody, IFN-gamma or IL-4 production of the each group was obviously higher than the control group (P Mycoplasma hyopneumoniae which has immunogenicity in mice especially by intramuscular injection could probably serve as a vaccine against mycoplasmal pneumonia of swine.

Allele-specific primer polymerase chain reaction for a single nucleotide polymorphism (C1205T) of swine Toll-like receptor 5 and comparison of the allelic frequency among several pig breeds in Japan and the Czech Republic

Czech Academy of Sciences Publication Activity Database

Muneta, Y.; Minagawa, Y.; Kusumoto, M.; Shinkai, H.; Uenishi, H.; Šplíchal, Igor

2012-01-01

Roč. 56, č. 6 (2012), s. 385-391 ISSN 0385-5600 R&D Projects: GA ČR GA524/09/0365 Institutional support: RVO:61388971 Keywords : allele-specific PCR * Salmonella enterica serovar Choleraesuis * single nucleotide polymorphism Subject RIV: EC - Immunology Impact factor: 1.545, year: 2012

Persistent Salmonella enterica serovar Typhimurium Infection Increases the Susceptibility of Mice to Develop Intestinal Inflammation

Directory of Open Access Journals (Sweden)

Bárbara M. Schultz

2018-05-01

Full Text Available Chronic intestinal inflammations are triggered by genetic and environmental components. However, it remains unclear how specific changes in the microbiota, host immunity, or pathogen exposure could promote the onset and exacerbation of these diseases. Here, we evaluated whether Salmonella enterica serovar Typhimurium (S. Typhimurium infection increases the susceptibility to develop intestinal inflammation in mice. Two mouse models were used to evaluate the impact of S. Typhimurium infection: the chemical induction of colitis by dextran sulfate sodium (DSS and interleukin (IL-10−/− mice, which develop spontaneous intestinal inflammation. We observed that S. Typhimurium infection makes DSS-treated and IL-10−/− mice more susceptible to develop intestinal inflammation. Importantly, this increased susceptibility is associated to the ability of S. Typhimurium to persist in liver and spleen of infected mice, which depends on the virulence proteins secreted by Salmonella Pathogenicity Island 2-encoded type three secretion system (TTSS-2. Although immunization with a live attenuated vaccine resulted in a moderate reduction of the IL-10−/− mice susceptibility to develop intestinal inflammation due to previous S. Typhimurium infection, it did not prevent bacterial persistence. Our results suggest that persistent S. Typhimurium infection may increase the susceptibility of mice to develop inflammation in the intestine, which could be associated with virulence proteins secreted by TTSS-2.

Immune Response of Chicken Gut to Natural Colonization by Gut Microflora and to Salmonella enterica Serovar Enteritidis Infection ▿

OpenAIRE

Crhanova, Magdalena; Hradecka, Helena; Faldynova, Marcela; Matulova, Marta; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

2011-01-01

In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut micro...

A Leptospira borgpetersenii Serovar Hardjo vaccine induces a Th1 response, activates NK cells, and reduces renal colonization

Science.gov (United States)

Chronic infection of cattle with Leptospira borgpetersenii serovar Hardjo reduces animal production through reproductive failure and presents a persistent health threat to workers in the animal industry. Cattle are maintenance hosts for serovar Hardjo and development of a protective vaccine has bee...

Characterization of Isolates of Salmonella enterica Serovar Stanley, a Serovar Endemic to Asia and Associated with Travel

DEFF Research Database (Denmark)

Hendriksen, Rene S.; Le Hello, Simon; Bortolaia, Valeria

2012-01-01

Salmonella enterica serovar Stanley (S. Stanley) is a common serovar in Southeast Asia and was the second most common serovar implicated in human salmonellosis in Thailand in the years 2002 to 2007. In contrast, this serovar is relatively uncommon in Europe. The objective of this study was to cha...

DETERMINASI SEROVAR BAKTERI LEPTOSPIRA PADA RESERVOIR DI KABUPATEN BANYUMAS

Directory of Open Access Journals (Sweden)

Tri Ramadhani

2016-05-01

Full Text Available Leptospirosis is an infectious disease caused by pathogenic Leptospira. Leptospirosis transmitted to human through direct contact with body fluids of infected animals or indirectly through contaminated puddles . The prevalence of leptospirosis in Banyumas tends to increase for 3 years. The purpose of this study was to determine the leptospira serovar in reservoir to prove of a current infection. Surveys was conducted using single live traps for three consecutive days, determination of leptospira serovar was conducted using Microscopic Aglutination Test (MAT. Data analysis was performed by univariate and presented in tables and graphs. The results showed that the trapped animals consisted of Rattus tanezumi (70.6% and Suncus murinus (29.4% with 6.5% succsess trap. Rattus tanezumi were dominantly caught inside the house (51% than outside the house (49%. Female rats were dominantly caught (66.7% than male rats (33.3%. Suncus murinus and Rattus tanezumi shown a titer of 1/100 to be infected with L.icterohaemorrhagiae , L.javanica and L.cynopteri which are pathogenic Leptospira in humans. Efforts are needed to improve community participation in preventing tranmission of leptospirosis by avoiding contact with contaminated water and soil. For people who are risk of exposure to infected animal should wear protective clothes or footwear.

A new multivalent (DHPPi/L4R) canine combination vaccine prevents infection, shedding and clinical signs following experimental challenge with four Leptospira serovars.

Science.gov (United States)

Wilson, Stephen; Stirling, Catrina; Thomas, Anne; King, Vickie; Plevová, Edita; Chromá, Ludmila; Siedek, Elisabeth; Illambas, Joanna; Salt, Jeremy; Sture, Gordon

2013-06-28

Although effective vaccines have been developed against the common Leptospira serovars, they are still reported in clinical cases, while others are increasingly prevalent. The results from four challenge studies following vaccination of dogs with a new combination vaccine (DHPPi/L4R) containing inactivated L. serovars, L. canicola, L. icterohaemorrhagiae, L. bratislava and L. grippotyphosa conducted to satisfy the requirements of the European Pharmacopoeia monograph (01/2008:0447), are reported. Six week old dogs received two vaccinations, three weeks apart, and were challenged 25 days later with different isolates of the L. serovars. Clinical observations were recorded, and blood, urine and tissue samples were collected for analysis. Following challenge, non-vaccinated dogs demonstrated various clinical signs, while no vaccinated dogs were affected; significant differences in mean clinical scores were observed. Measurable antibody titres to each Leptospira antigen were seen in vaccinated dogs 21 days following the first vaccination, with further increases in antibody titres observed following challenge with the respective Leptospira strain. Non-vaccinated dogs remained seronegative until challenge. Leptospira were re-isolated from the blood, urine, kidney and liver of all non-vaccinated dogs following challenge. In contrast no vaccinated dogs had Leptospira re-isolated from the same tissues. Significant differences were seen in number of days with positive isolation (blood and urine) and in number of dogs with positive samples (kidney and liver). In conclusion, vaccination of dogs with the new vaccine induces protective immunity 25 days after second vaccination with protection against infection, renal infection and clinical signs following challenge. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of propolis from Brazil and Bulgaria on Salmonella serovars

Directory of Open Access Journals (Sweden)

R. O. Orsi

2007-01-01

Full Text Available Propolis shows biological properties such as antibacterial action. This bee product has a complex chemical composition, which depends on the local flora where it is produced. Salmonella serovars are responsible for human diseases that range from localized gastroenteritis to systemic infections. The aim of the present study was to investigate the susceptibility of Salmonella strains, isolated from food and infectious processes, to the antibacterial action of Brazilian and Bulgarian propolis, as well as to determine the behavior of these bacteria, according to the incubation period, in medium plus propolis. Dilution of ethanolic extract of propolis in agar was the used method. Brazilian and Bulgarian propolis showed an antibacterial action against all Salmonella serovars. The minimal inhibitory concentrations (MIC of propolis were similar, although they were collected in different geographic regions. Salmonella typhimurium, isolated from human infection, was more resistant to propolis than Salmonella enteritidis.

Evaluation of the use of selective PCR amplification of LPS biosynthesis genes for molecular typing of leptospira at the serovar level

NARCIS (Netherlands)

Bezerra da Silva, Josefa; Carvalho, Eneas; Hartskeerl, Rudy A.; Ho, Paulo L.

2011-01-01

Leptospirosis is an important epidemic zoonosis worldwide. Currently, there are more than 250 Leptospira pathogenic serovars known that can potentially infect humans. Conventional classification of leptospires with the serovar as the basic taxon, based on serological recognition of

Same species, different diseases: how and why typhoidal and non-typhoidal Salmonella enterica serovars differ

Directory of Open Access Journals (Sweden)

Ohad eGal-Mor

2014-08-01

Full Text Available Human infections by the bacterial pathogen Salmonella enterica represent major disease burdens worldwide. This highly ubiquitous species consists of more than 2600 different serovars that can be divided into typhoidal and non-typhoidal Salmonella (NTS serovars. Despite their genetic similarity, these two groups elicit very different diseases and distinct immune responses in humans. Comparative analyses of the genomes of multiple Salmonella serovars have begun to explain the basis of the variation in disease manifestations. Recent advances in modeling both enteric fever and intestinal gastroenteritis in mice will facilitate investigation into both the bacterial- and host-mediated mechanisms involved in salmonelloses. Understanding the genetic and molecular mechanisms responsible for differences in disease outcome will augment our understanding of Salmonella pathogenesis, host immunity, and the molecular basis of host specificity. This review outlines the differences in epidemiology, clinical manifestations, and the human immune response to typhoidal and NTS infections and summarizes the current thinking on why these differences might exist.

Beneficial Effects of Sodium Phenylbutyrate Administration during Infection with Salmonella enterica Serovar Typhimurium.

Science.gov (United States)

Jellbauer, Stefan; Perez Lopez, Araceli; Behnsen, Judith; Gao, Nina; Nguyen, Thao; Murphy, Clodagh; Edwards, Robert A; Raffatellu, Manuela

2016-09-01

Sodium phenylbutyrate (PBA) is a derivative of the short-chain fatty acid butyrate and is approved for treatment of urea cycle disorders and progressive familial intrahepatic cholestasis type 2. Previously known functions include histone deacetylase inhibitor, endoplasmic reticulum stress inhibitor, ammonia sink, and chemical chaperone. Here, we show that PBA has a previously undiscovered protective role in host mucosal defense during infection. Administration of PBA to Taconic mice resulted in the increase of intestinal Lactobacillales and segmented filamentous bacteria (SFB), as well as an increase of interleukin 17 (IL-17) production by intestinal cells. This effect was not observed in Jackson Laboratory mice, which are not colonized with SFB. Because previous studies showed that IL-17 plays a protective role during infection with mucosal pathogens, we hypothesized that Taconic mice treated with PBA would be more resistant to infection with Salmonella enterica serovar Typhimurium (S Typhimurium). By using the streptomycin-treated mouse model, we found that Taconic mice treated with PBA exhibited significantly lower S Typhimurium intestinal colonization and dissemination to the reticuloendothelial system, as well as lower levels of inflammation. The lower levels of S Typhimurium gut colonization and intestinal inflammation were not observed in Jackson Laboratory mice. Although PBA had no direct effect on bacterial replication, its administration reduced S Typhimurium epithelial cell invasion and lowered the induction of the proinflammatory cytokine IL-23 in macrophage-like cells. These effects likely contributed to the better outcome of infection in PBA-treated mice. Overall, our results suggest that PBA induces changes in the microbiota and in the mucosal immune response that can be beneficial to the host during infection with S Typhimurium and possibly other enteric pathogens. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Rapid Detection of Chlamydia trachomatis and Typing of the Lymphogranuloma venereum associated L-Serovars by TaqMan PCR

Directory of Open Access Journals (Sweden)

Henrich Birgit

2008-04-01

Full Text Available Abstract Background Infection due to Chlamydia trachomatis is the most common sexually transmitted bacterial disease of global health significance, and especially the L-serovars causing lymphogranuloma venereum are increasingly being found in Europe in men who have sex with men. Results The design and evaluation of a rapid, multiplex, real-time PCR targeting the major outer membrane protein (omp-1 -gene and a L-serovar-specific region of the polymorphic protein H (pmp-H -gene for the detection of Chlamydia trachomatis is reported here. The PCR takes place as a single reaction with an internal control. For L1-, L2- and L3-serovar differentiation a second set of real-time PCRs was evaluated based on the amplification of serovar-specific omp-1-regions. The detection limit of each real-time PCR, multiplexed or not, was 50 genome copies per reaction with an efficiency ranging from 90,5–95,2%. In a retrospective analysis of 50 ocular, rectal and urogenital specimens formerly tested to be positive for C. trachomatis we identified six L2-serovars in rectal specimens of HIV-positive men, one in a double-infection with L3, and one L2 in a urethral specimen of an HIV-negative male. Conclusion This unique real-time PCR is specific and convenient for the rapid routine-diagnostic detection of lymphogranuloma venereum-associated L-serovars and enables the subsequent differentiation of L1, L2 and L3 for epidemiologic studies.

Rapid Detection of Chlamydia trachomatis and Typing of the Lymphogranuloma venereum associated L-Serovars by TaqMan PCR

Science.gov (United States)

Schaeffer, Anke; Henrich, Birgit

2008-01-01

Background Infection due to Chlamydia trachomatis is the most common sexually transmitted bacterial disease of global health significance, and especially the L-serovars causing lymphogranuloma venereum are increasingly being found in Europe in men who have sex with men. Results The design and evaluation of a rapid, multiplex, real-time PCR targeting the major outer membrane protein (omp-1) -gene and a L-serovar-specific region of the polymorphic protein H (pmp-H) -gene for the detection of Chlamydia trachomatis is reported here. The PCR takes place as a single reaction with an internal control. For L1-, L2- and L3-serovar differentiation a second set of real-time PCRs was evaluated based on the amplification of serovar-specific omp-1-regions. The detection limit of each real-time PCR, multiplexed or not, was 50 genome copies per reaction with an efficiency ranging from 90,5–95,2%. In a retrospective analysis of 50 ocular, rectal and urogenital specimens formerly tested to be positive for C. trachomatis we identified six L2-serovars in rectal specimens of HIV-positive men, one in a double-infection with L3, and one L2 in a urethral specimen of an HIV-negative male. Conclusion This unique real-time PCR is specific and convenient for the rapid routine-diagnostic detection of lymphogranuloma venereum-associated L-serovars and enables the subsequent differentiation of L1, L2 and L3 for epidemiologic studies. PMID:18447917

Expression of hilA in response to mild acid stress in Salmonella enterica is serovar and strain dependent.

Science.gov (United States)

González-Gil, Francisco; Le Bolloch, Alexandre; Pendleton, Sean; Zhang, Nan; Wallis, Audra; Hanning, Irene

2012-05-01

Salmonella enterica is the leading cause of foodborne illness with poultry and poultry products being primary sources of infection. The 2 most common S. enterica serovars associated with human infection are Typhimurium and Enteritidis. However, Kentucky and Heidelburg and the 2 most prevalent serovars isolated from poultry environments. Given the prevalence of other serovars in poultry products and environments, research is needed to understand virulence modulation in response to stress in serovars other than Typhimurium and Enteritidis. Thus, the objective of this research was to compare hilA gene expression (a master regulator of the virulence pathogenicity island) in response to acid stress among different strains and serovars of Salmonella. A total of 11 serovars consisting of 15 strains of S. enterica were utilized for these experiments. Cultures were suspended in tryptic soy broth (TSB) adjusted to pH 7.2, 6.2, or 5.5 with HCl or acetic acid. Total RNA was extracted from cultures at specific time points (0, 2, 4, and 24 h). Gene expression of hilA was measured with quantitative reverse transcriptase real time PCR (qRT-PCR). Growth and pH were measured throughout the 24 h time frame. Regulation of hilA in response to acid stress varied by serovar and strain and type of acid. The results of these experiments indicate that hilA regulation may have some impact on virulence and colonization of S. enterica. However, these results warrant further research to more fully understand the significance of hilA regulation in response to mild acid stress in S. enterica. © 2012 Institute of Food Technologists®

Comparative genomic analysis of Brazilian Leptospira kirschneri serogroup Pomona serovar Mozdok

Directory of Open Access Journals (Sweden)

Luisa Z Moreno

2016-08-01

Full Text Available Leptospira kirschneri is one of the pathogenic species of the Leptospira genus. Human and animal infection from L. kirschneri gained further attention over the last few decades. Here we present the isolation and characterisation of Brazilian L. kirschneri serogroup Pomona serovar Mozdok strain M36/05 and the comparative genomic analysis with Brazilian human strain 61H. The M36/05 strain caused pulmonary hemorrhagic lesions in the hamster model, showing high virulence. The studied genomes presented high symmetrical identity and the in silico multilocus sequence typing analysis resulted in a new allelic profile (ST101 that so far has only been associated with the Brazilian L. kirschneri serogroup Pomona serovar Mozdok strains. Considering the environmental conditions and high genomic similarity observed between strains, we suggest the existence of a Brazilian L. kirschneri serogroup Pomona serovar Mozdok lineage that could represent a high public health risk; further studies are necessary to confirm the lineage significance and distribution.

Epidemiological investigation of Salmonella enterica serovar Kedougou in Thailand.

Science.gov (United States)

Pornruangwong, Srirat; Hendriksen, Rene S; Pulsrikarn, Chaiwat; Bangstrakulnonth, Aroon; Mikoleit, Matthew; Davies, Rob H; Aarestrup, Frank M; Garcia-Migura, Lourdes

2011-02-01

Salmonella enterica serovar Kedougou is among the top 10 serovars reported in northern Thailand. The objective of this study was to identify risk factors associated with Salmonella Kedougou infection in Thailand and to compare the molecular types and antimicrobial resistance with Salmonella Kedougou isolates of human origin from United States and of animal origin from the United Kingdom. Data from 13,976 Salmonella infections of which 253 were Salmonella Kedougou collected in Thailand between 2002 and 2008 were analyzed by logistic regression. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on selected Salmonella Kedougou strains causing infections in Thailand (n = 66), and compared to isolates from the United States (n = 5) and the United Kingdom (n = 20). Logistic analysis revealed season (hot/dry; p = 0.023), region (northern Thailand; p Thailand were resistant to third-generation cephalosporins: two harbored bla(CTX-M-63) and one bla(CMY-2). PFGE revealed 45 unique clusters. Isolates obtained from humans in Thailand and the United States presented identical PFGE profiles suggesting a travel association, whereas the majority of the animal isolates from United Kingdom clustered separately. This study reveals Salmonella Kedougou as a major cause of human infections in northern Thailand especially during the hot period and suggests a global spread probably due to travel. The clonal types causing infections in humans differed from those observed in animals in United Kingdom, which suggests the absence of an epidemiological link and could suggest differences in virulence. The high frequency of antimicrobial resistance, including emergence of resistance to fluoroquinolones and third-generation cephalosporins, might pose problems for treatment of infections.

Development of a rectal sexually transmitted infection (STI) Model in Rhesus macaques using Chlamydia trachomatis serovars E and L2.

Science.gov (United States)

Henning, Tara R; Morris, Monica; Ellis, Shanon; Kelley, Kristen; Phillips, Christi; Ritter, Jana; Jones, Tara; Nachamkin, Eli; Chen, Cheng Y; Hong, Jaeyoung; Kang, Joseph; Patton, Dorothy; McNicholl, Janet; Papp, John; Kersh, Ellen N

2017-10-01

Rectal STI coinfection models enhance the understanding of rectal HIV transmission risk factors. Rhesus macaques (n=9) were exposed to one of three rectal Chlamydia trachomatis (CT) challenges: C. trachomatis L 2 (CT-L 2 ); C. trachomatis serovar E (CT-E), followed by CT-L 2 ; or CT-E, treatment/clearance, then CT-L 2 . Infections were monitored by PCR. Weekly blood and rectal secretion/lavage samples were collected for cytokine analyzes and/or epithelial sloughing, occult, and overt blood determinations. Chlamydial infections were successfully established in each animal, with varying degrees of persistence. Mucosal IL-1beta was upregulated in animals consecutively infected with CT-E then CT-L 2 (P=.05). Epithelial sloughing was also significantly increased post-infection in this group (P=.0003). This study demonstrates successful rectal infection of rhesus macaques with CT-E and CT-L 2 and describes measures of assessing rectal inflammation and pathology. Different infection strategies yield varying inflammatory and pathologic outcomes, providing well-described models for future SIV/SHIV susceptibility studies. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

ORF Alignment: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006905 gi|62181272 >1gdtA 1 182 1 183 1e-47 ... ref|YP_217689.1| H inversion: regu...lation of flagellar gene expression by ... site-specific inversion of DNA [Salmonella enterica ... ... ... subsp. enterica serovar Choleraesuis str. SC-B67] ... gb|AAX66608.1| H inversion: regulation of ...flagellar gene ... expression by site-specific inversion of DNA [Salmonell

Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

Science.gov (United States)

Johnson, Timothy J.; Ricke, Steven C.; Nayak, Rajesh; Danzeisen, Jessica

2013-01-01

SUMMARY Enteric pathogens such as Salmonella enterica cause significant morbidity and mortality. S. enterica serovars are a diverse group of pathogens that have evolved to survive in a wide range of environments and across multiple hosts. S. enterica serovars such as S. Typhi, S. Dublin, and S. Gallinarum have a restricted host range, in which they are typically associated with one or a few host species, while S. Enteritidis and S. Typhimurium have broad host ranges. This review examines how S. enterica has evolved through adaptation to different host environments, especially as related to the chicken host, and continues to be an important human pathogen. Several factors impact host range, and these include the acquisition of genes via horizontal gene transfer with plasmids, transposons, and phages, which can potentially expand host range, and the loss of genes or their function, which would reduce the range of hosts that the organism can infect. S. Gallinarum, with a limited host range, has a large number of pseudogenes in its genome compared to broader-host-range serovars. S. enterica serovars such as S. Kentucky and S. Heidelberg also often have plasmids that may help them colonize poultry more efficiently. The ability to colonize different hosts also involves interactions with the host's immune system and commensal organisms that are present. Thus, the factors that impact the ability of Salmonella to colonize a particular host species, such as chickens, are complex and multifactorial, involving the host, the pathogen, and extrinsic pressures. It is the interplay of these factors which leads to the differences in host ranges that we observe today. PMID:24296573

Species and serovars of the genus Listeria lsolated from different sources in Brazil from 1971 to 1997

Directory of Open Access Journals (Sweden)

Hofer Ernesto

2000-01-01

Full Text Available Using phenotype techniques, characterization was made to species and serovar of 3,112 strains of Listeria, isolated from different sources of infection such as human (247-7.9% and animals (239-7.6%, as well as from various routes of infection, including food (2,330-74.8% and environmental constituents (296-9.5%, all coming from different regions of the country and collected during the period 1971-1997. The following species were recovered in the cultures analysed: L. monocytogenes (774-24.8%, L. innocua (2,269-72.9%, L. seeligeri (37-1.1%, L. welshimeri (22-0.7%, L. grayi (9-0.2%, and L. ivanovii (1-0.03%. L. monocytogenes was represented by ten serovars, the most prevalent being 4b (352-11.3%, 1/2a (162-5.2%, and 1/2b (148-4.7%. The predominant serovar in L. innocua was 6a (2,093-67.2%. Considerations about laboratory methods for diagnosis and epidemiological aspects are presented on the basis of the results obtained.

Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

Science.gov (United States)

Andino, A.; Hanning, I.

2015-01-01

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

Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

Directory of Open Access Journals (Sweden)

A. Andino

2015-01-01

Full Text Available 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.

Babies and bearded dragons: sudden increase in reptile-associated Salmonella enterica serovar Tennessee infections, Germany 2008.

Science.gov (United States)

Weiss, Bettina; Rabsch, Wolfgang; Prager, Rita; Tietze, Erhard; Koch, Judith; Mutschmann, Frank; Roggentin, Peter; Frank, Christina

2011-09-01

In 2008 a marked increase in Salmonella enterica serovar Tennessee infections in infants occurred in Germany. In March and April 2008, eight cases were notified compared to a median of 0-1 cases in 2001-2006. We carried out an investigation including a case-control study to identify the source of infection. A patient was a child < 3 years of age with Salmonella Tennessee isolated from stool from September 1, 2007, through December 31, 2008, identified through the national surveillance system. A control was a child with a notified rotavirus infection in the matching district, frequency matched by age group. We conducted telephone interviews on feeding, herbal infusions, and animal contact. Matched odds ratios (mOR) were calculated using exact conditional logistic regression. For Salmonella Tennessee isolates, pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis were performed. Further cloacal swab samples of reptiles kept in case households were investigated. We identified 18 cases < 3 years. Ten children were male; median age was 3 months (1-32 months). In 8 of 16 case households reptiles were kept. Direct contact between child and reptile was denied. Other forms of reptile contact were reported in four of the remaining eight households. Ten case- and 21 control-patients were included in the study. Only keeping of a reptile and "any reptile contact" were associated with Salmonella Tennessee infection (mOR 29.0; 95% CI 3.1 ± ∞ and mOR 119.5; 95% CI 11.7 - ∞). Identical Salmonella Tennessee strains of child and reptile kept in the same household could be shown in 2 cases. Reptiles were the apparent source of Salmonella Tennessee infection in these infants. Indirect contact between infants and reptiles seems to be sufficient to cause infection and should therefore be avoided.

Molecular characterization, serotyping, and antibiotic susceptibility profile of Leptospira interrogans serovar Copenhageni isolates from Brazil

NARCIS (Netherlands)

Miraglia, Fabiana; Matsuo, Minekazo; Morais, Zenaide Maria; Dellagostin, Odir Antonio; Seixas, Fabiana Kömmling; Freitas, Julio César; Hartskeerl, Rudy; Moreno, Luisa Zanolli; Costa, Bárbara Letícia; Souza, Gisele Oliveira; Vasconcellos, Silvio Arruda; Moreno, Andrea Micke

2013-01-01

Leptospira interrogans serogroup Icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the

Cloning and Sequencing of Gene Encoding Outer Membrane Lipoprotein LipL41 of Leptospira Interrogans Serovar Grippotyphosa

Directory of Open Access Journals (Sweden)

M.S. Soltani

2014-12-01

Full Text Available Background: Leptospirosis is an infectious bacterial disease caused by pathogenic serovars of Leptospira. Development of reliable and applicable diagnostic test and also recombinant vaccine for this disease require specific antigens that are highly conserved among diverse pathogenic leptospiral serovars. Outer membrane proteins(OMPs of leptospira are effective antigens which can stimulate remarkable immune responses during infection, among them LipL41 is an immunogenic lipoprotein which is present only in pathogenic serovars so it could be regarded as a good candidate for vaccine development and diagnostic method. In order to identify genetic conservation of the lipL41 gene, we cloned and sequenced this gen from Leptospira interrogans serovar vaccinal and field of Grippotyphosa. Materials and Methods: Leptospira interrogans serovar vaccinal Grippotyphosa (RTCC2808 and serovar field Grippotyphosa (RTCC2825were used to inoculate into the selective culture medium(EMJH. The genomic DNA was extracted by standard phenol-chloroform method. The lipL41 gene were amplified by specific primers and cloned into pTZ57R/T vector and transformed into the competent E. coli (Top10 cells. the extracted recombinant plasmid were sequenced. And the related sequences were subjected to homology analysis by comparing them to sequences in the Genbank database. Results: PCR amplification of the lipL41 gene resulted in the 1065 bp PCR product. DNA sequence analysis revealed that lipL41 gene between serovar vaccinal Grippotyphosa (RTCC2808and serovar field Grippotyphosa (RTCC2825 in Iran was 100%. It was also showed that the lipL41 gene had high identity (96%-100% with other pathogenic serovars submitted in Genbank database. Conclusion: The results of this study showed that the lipL41 gene was highly conserved among various pathogenic Leptospira serovars( >95.9 % identity. Hence the cloned gene could be further used for expression of recombinant protein for serodiagnosis

Genomic and Phenotypic Analyses Reveal the Emergence of an Atypical Salmonella enterica Serovar Senftenberg Variant in China

KAUST Repository

Abd El Ghany, Moataz; Shi, Xiaolu; Li, Yinghui; Ansari, Hifzur Rahman; Hill-Cawthorne, Grant A.; Ho, Y. S.; Naeem, Raeece; Pickard, Derek; Klena, John D.; Xu, Xuebing; Pain, Arnab; Hu, Qinghua

2016-01-01

Human infections with Salmonella enterica subspecies enterica serovar Senftenberg are often associated with exposure to poultry flocks, farm environments, or contaminated food. The recent emergence of multidrug-resistant isolates has raised public

Prevalence, serovars and antimicrobial susceptibility of Salmonella spp. from wild and domestic green iguanas (Iguana iguana) in Grenada, West Indies.

Science.gov (United States)

Sylvester, W R B; Amadi, V; Pinckney, R; Macpherson, C N L; McKibben, J S; Bruhl-Day, R; Johnson, R; Hariharan, H

2014-09-01

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4-month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty-five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z51 :- (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin-clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim-sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies. © 2013 Blackwell Verlag GmbH.

Genital tract lesions in sexually mature Göttingen minipigs during the initial stages of experimental vaginal infection with Chlamydia trachomatis serovar D.

Science.gov (United States)

Erneholm, Karin; Lorenzen, Emma; Bøje, Sarah; Olsen, Anja Weinreich; Andersen, Peter; Cassidy, Joseph P; Follmann, Frank; Jensen, Henrik E; Agerholm, Jørgen S

2016-09-10

Chlamydia is one of the most common sexually transmitted diseases in humans worldwide, causing chronic lesions in the reproductive tract. Due to its often asymptomatic course, there is limited knowledge about the initial changes in the genital tract following infection. This study employs a novel sexually mature minipig model to investigate the initial histopathological changes following vaginal infection with Chlamydia trachomatis serovar D. A vaginal inoculation resulted in an infection primarily affecting the lower genital tract. The histopathological changes were characterized by a subepithelial inflammation consisting of neutrophils and mononuclear cells, followed by an increase in the number of plasma cells within the sub-epithelial stroma of the vagina. Detection of Chlamydia was associated with expression of cyclooxygenase-2 and interleukin-8 by superficial epithelial cells. The infection was self-limiting, with a duration of 7 days. Neutrophils, plasma cells and IL-8 have been linked with Chlamydia genital infection of unknown duration in human patients. In this study, we observe a similar pattern of local immune response/inflammation following experimental inoculation suggesting this porcine model shows promise as a model for translational chlamydia research.

Listeria monocytogenes serovar 4a is a possible evolutionary intermediate between L. monocytogenes serovars 1/2a and 4b and L. innocua.

Science.gov (United States)

Chen, Jianshun; Jiang, Lingli; Chen, Xueyan; Luo, Xiaokai; Chen, Yang; Yu, Ying; Tian, Guoming; Liu, Dongyou; Fang, Weihuan

2009-03-01

The genus Listeria consists of six closely related species and forms three phylogenetic groups: L. monocytogenes- L. innocua, L. ivanovii-L. seeligeri-L. welshimeri, and L. grayi. In this report, we attempted to examine the evolutionary relationship in the L. monocytogenes-L. innocua group by probing the nucleotide sequences of 23S rRNA and 16S rRNA, and the gene clusters lmo0029-lmo0042, ascBdapE, rplS-infC, and prs-ldh in L. monocytogenes serovars 1/2a, 4a, and 4b, and L. innocua. Additionally, we assessed the status of L. monocytogenes-specific inlA and inlB genes and 10 L. innocua-specific genes in these species/serovars, together with phenotypic characterization by using in vivo and in vitro procedures. The results indicate that L. monocytogenes serovar 4a strains are genetically similar to L. innocua in the lmo0035-lmo0042, ascB-dapE, and rplS-infC regions and also possess L. innocua-specific genes lin0372 and lin1073. Furthermore, both L. monocytogenes serovar 4a and L. innocua exhibit impaired intercellular spread ability and negligible pathogenicity in mouse model. On the other hand, despite resembling L. monocytogenes serovars 1/2a and 4b in having a nearly identical virulence gene cluster, and inlA and inlB genes, these serovar 4a strains differ from serovars 1/2a and 4b by harboring notably altered actA and plcB genes, displaying strong phospholipase activity and subdued in vivo and in vitro virulence. Thus, by possessing many genes common to L. monocytogenes serovars 1/2a and 4b, and sharing many similar gene deletions with L. innocua, L. monocytogenes serovar 4a represents a possible evolutionary intermediate between L. monocytogenes serovars 1/2a and 4b and L. innocua.

Invasive Non-typhoidal Salmonella Infections in Asia: Clinical Observations, Disease Outcome and Dominant Serovars from an Infectious Disease Hospital in Vietnam.

Directory of Open Access Journals (Sweden)

Nguyen Phu Huong Lan

2016-08-01

Full Text Available Invasive non-typhoidal Salmonella (iNTS infections are now a well-described cause of morbidity and mortality in children and HIV-infected adults in sub-Saharan Africa. In contrast, the epidemiology and clinical manifestations of iNTS disease in Asia are not well documented. We retrospectively identified >100 cases of iNTS infections in an infectious disease hospital in Southern Vietnam between 2008 and 2013. Clinical records were accessed to evaluate demographic and clinical factors associated with iNTS infection and to identify risk factors associated with death. Multi-locus sequence typing and antimicrobial susceptibility testing was performed on all organisms. Of 102 iNTS patients, 71% were HIV-infected, >90% were adults, 71% were male and 33% reported intravenous drug use. Twenty-six/92 (28% patients with a known outcome died; HIV infection was significantly associated with death (p = 0.039. S. Enteritidis (Sequence Types (ST11 (48%, 43/89 and S. Typhimurium (ST19, 34 and 1544 (26%, 23/89 were the most commonly identified serovars; S. Typhimurium was significantly more common in HIV-infected individuals (p = 0.003. Isolates from HIV-infected patients were more likely to exhibit reduced susceptibility against trimethoprim-sulfamethoxazole than HIV-negative patients (p = 0.037. We conclude that iNTS disease is a severe infection in Vietnam with a high mortality rate. As in sub-Saharan Africa, HIV infection was a risk factor for death, with the majority of the burden in this population found in HIV-infected adult men.

Chlamydia trachomatis serovar distribution and other sexually transmitted coinfections in subjects attending an STD outpatients clinic in Italy.

Science.gov (United States)

Marangoni, Antonella; Foschi, Claudio; Nardini, Paola; D'Antuono, Antonietta; Banzola, Nicoletta; Di Francesco, Antonietta; Ostanello, Fabio; Russo, Incoronata; Donati, Manuela; Cevenini, Roberto

2012-04-01

We studied the prevalence of Chlamydia trachomatis (CT) urogenital infection and the distribution of different genotypes in a non-selected STD population of 1625 patients, evaluating presence of coinfections with other sexually transmitted diseases. Each patient was bled to perform serological tests for syphilis and HIV, then urethral or endocervical swabs were obtained for the detection of CT and Neisseria gonorrhoeae by culture. DNA extracted from remnant positive swabs was amplified by omp1 Nested PCR and products were sequenced. Total prevalence of CT infection was 6.3% (103/1625), with strong differences between men and women (11.4% vs 3.9%, Pmen than in women (Pmen and women (P=0.042) and among patients with or without coinfection (P=0.035); patients infected by serovar D/Da showed the highest coinfection rate. This study can be considered a contribution in increasing knowledge on CT serovar distribution in Italy. Further studies are needed to better define molecular epidemiology of CT infection and to investigate its correlation with other STDs.

Immunological changes at point-of-lay increase susceptibility to Salmonella enterica Serovar enteritidis infection in vaccinated chickens.

Directory of Open Access Journals (Sweden)

Claire E Johnston

Full Text Available Chicken eggs are the main source of human Salmonella enterica serovar Enteritidis infection. S. Enteritidis infects the oviduct and ovary of the chicken leading to infection of developing eggs. Therefore, control in poultry production is a major public health priority. Vaccination of hens has proved successful in control strategies in United Kingdom leading to a 70% drop in human cases since introduced. However, as hens reach sexual maturity they become immunosuppressed and it has been postulated this leads to increased susceptibility to Salmonella infection. In this study we define the changes to the systemic and reproductive tract-associated immune system of hens throughout sexual development by flow cytometry and histology and determine changes in susceptibility to experimental S. Enteritidis challenge in naive and vaccinated hens. Changes to both systemic and local immune systems occur in chickens at sexual development around 140 days of age. The population of several leukocyte classes drop, with the greatest fall in CD4+ lymphocyte numbers. Within the developing reproductive tract there an organised structure of lymphocytic aggregates with γδ-T lymphocytes associated with the mucosa. At point-of-lay, this organised structure disappears and only scattered lymphocytes remain. Protection against Salmonella challenge is significantly reduced in vaccinated birds at point-of-lay, coinciding with the drop in CD4+ lymphocytes. Susceptibility to reproductive tract infection by Salmonella increased in vaccinated and naïve animals at 140 and 148 days of age. We hypothesise that the drop in γδ-T lymphocytes in the tract leads to decreased innate protection of the mucosa to infection. These findings indicate that systemic and local changes to the immune system increase the susceptibility of hens to S. Enteritidis infection. The loss of protective immunity in vaccinated birds demonstrates that Salmonella control should not rely on vaccination alone

Chlortetracycline and florfenicol induce expression of genes associated with pathogenicity in multidrug-resistant Salmonella enterica serovar Typhimurium

Science.gov (United States)

Background Multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Typhimurium) is a serious public health threat as infections caused by these strains are more difficult and expensive to treat. Livestock serve as a reservoir for MDR Salmonella, and the antibiotics chlortetracycline an...

Characterization of Leptospira santarosai Serogroup Grippotyphosa Serovar Bananal Isolated from Capybara ( Hydrochaeris hydrochaeris ) in Brazil.

Science.gov (United States)

Moreno, Luisa Z; Miraglia, Fabiana; Marvulo, Maria F V; Silva, Jean C R; Paula, Catia D; Costa, Barbara L P; Morais, Zenaide M; Ferreira, Fernando; Neto, José S Ferreira; Dellagostin, Odir A; Hartskeerl, Rudy A; Vasconcellos, Silvio A; Moreno, Andrea M

2016-07-01

Leptospirosis is a widespread zoonosis caused by bacteria of the genus Leptospira. Rodents appear to be the most important reservoirs of infection. They contaminate the environment and food and can transmit the pathogen when they are consumed by carnivores. Capybara ( Hydrochaeris hydrochaeris ) are efficient reservoirs of Leptospira, and because they are in close contact with farm animals and are found in semiurban areas, they represent a risk to public health. We isolated five Leptospira strains from capybara kidneys in Sao Paulo State, Brazil, in 2001 and typed them using serologic and molecular techniques. These strains include the Leptospira santarosai serogroup Grippotyphosa serovar Bananal. Pulsed field gel electrophoresis resulted in a unique pattern distinct from the reference strains, and the isolates clustered with greater than 85% similarity. The isolates also presented higher growth rates than other Leptospira serovars, with high minimal inhibitory concentration values for most of the tested antibiotics, with the exception of penicillin and ampicillin. This isolation and characterization of the L. santarosai serogroup Grippotyphosa serovar Bananal from capybara, highlights the importance of wild and sinantropic rodents as carriers of pathogenic leptospires.

Genomic analysis of $\\textit{Salmonella enterica}$ serovar Typhimurium from wild passerines in England and Wales

OpenAIRE

Mather, Alison E; Lawson, Becki; de, Pinna Elizabeth; Wigley, Paul; Parkhill, Julian; Thomson, Nicholas R; Page, Andrew J; Holmes, Mark Adrian; Paterson, Gavin K

2016-01-01

Passerine salmonellosis is a well-recognised disease of birds in the order Passeriformes, including common songbirds such as finches and sparrows, caused by infection with $\\textit{Salmonella enterica}$ serovar Typhimurium. Previous research has suggested that some subtypes of S. Typhimurium – definitive phage types (DT) 40, 56 variant, and 160 – are host-adapted to passerines, and that these birds may represent a reservoir of infection for humans and other animals. Here, we have used whole g...

Serovars of Salmonella from captive reptiles

DEFF Research Database (Denmark)

Pedersen, Karl; Lassen-Nielsen, Anne Marie; Nordentoft, Steen

2009-01-01

The distribution on serovars of 60 Salmonella isolates from reptiles kept in captivity in Denmark during the period 1995–2006 was investigated. The isolates were all recovered from clinical specimens submitted to the National Veterinary Institute. A majority of the samples were from reptiles...... in zoological gardens or similar, while a minor number was from reptiles kept in private homes. A total of 43 serovars were detected, most of them being what is usually called exotic serotypes, and many not having a trivial name, while a few isolates belonged to well-known human pathogenic serovars, such as S....... Enteritidis, S. Typhimurium, S. Bovismorbificans. One isolate was rough and two were non-typeable. Isolates from turtles belonged to the subspecies enterica, while many isolates from both sauria and snakes belonged to other subspecies. The findings underline the potential zoonotic risk by handling reptiles...

Passive surveillance of Leptospira infection in swine in Germany.

Science.gov (United States)

Strutzberg-Minder, Katrin; Tschentscher, Astrid; Beyerbach, Martin; Homuth, Matthias; Kreienbrock, Lothar

2018-01-01

As no current data are available on the prevalence of leptospiral infection in swine in Germany, we analysed laboratory data from diagnostic examinations carried out on samples from swine all over Germany from January 2011 to September 2016. A total of 29,829 swine sera were tested by microscopic agglutination test (MAT) for antibodies against strains of eleven Leptospira serovars. Overall, 20.2% (6025) of the total sample collection tested positive for leptospiral infection. Seropositivity ranged between 16.3% (964) in 2011 and 30.9% (941) in 2016 (January to September only). Of all samples, 11.6% (57.3% of the positives) reacted with only one Leptospira serovar, and only 8.6% (42.7% of the positives) reacted simultaneously with two or more serovars. The most frequently detected serovar was Bratislava, which was found in 11.6% (3448) of all samples, followed by the serovars Australis in 7.3% (2185), Icterohaemorrhagiae in 4.0% (1191), Copenhageni in 4.0% (1182), Autumnalis in 3.7% (1054), Canicola in 2.0% (585), and Pomona in 1.2% (368). Modelling shows that both the year and the reason for testing at the laboratory had statistically strong effects on the test results; however, no interactions were determined between those factors. The results support the suggestion that the seropositivities found may be considered to indicate the state of leptospiral infections in the German swine population. Although data from passive surveillance are prone to selection bias, stratified analysis by initial reason for examination and analyses by model approaches may correct for biases. A prevalence of about 20% for a leptospiral infection is most probable for sows with reproductive problems in Germany, with an increasing trend. Swine in Germany are probably a reservoir host for serovar Bratislava, but in contrast to other studies not for Pomona and Tarassovi.

Camel as a transboundary vector for emerging exotic Salmonella serovars.

Science.gov (United States)

Ghoneim, Nahed H; Abdel-Moein, Khaled A; Zaher, Hala

2017-05-01

The current study was conducted to shed light on the role of imported camels as a transboundary vector for emerging exotic Salmonella serovars. Fecal samples were collected from 206 camels directly after slaughtering including 25 local camels and 181 imported ones as well as stool specimens were obtained from 50 slaughterhouse workers at the same abattoir. The obtained samples were cultured while Salmonella serovars were identified through Gram's stain films, biochemical tests and serotyping with antisera kit. Moreover, the obtained Salmonella serovars were examined by PCR for the presence of invA and stn genes. The overall prevalence of Salmonella serovars among the examined camels was 8.3%. Stn gene was detected in the vast majority of exotic strains (11/14) 78.6% including emerging serovars such as Salmonella Saintpaul, S. Chester, S. Typhimurium whereas only one isolate from local camels carried stn gene (1/3) 33.3%. On the other hand, none of the examined humans yielded positive result. Our findings highlight the potential role of imported camels as a transboundary vector for exotic emerging Salomenella serovars.

Molecular identification of the ompL1 gene within Leptospira interrogans standard serovars.

Science.gov (United States)

Dezhbord, Mehrangiz; Esmaelizad, Majid; Khaki, Pejvak; Fotohi, Fariba; Zarehparvar Moghaddam, Athena

2014-06-11

Leptospirosis, caused by infection with pathogenic Leptospira species, is one of the most prevalent zoonotic diseases in the world. Current leptospiral vaccines are mainly multivalent dead whole-cell mixtures made of several local dominant serovars. Therefore, design and construction of an efficient recombinant vaccine for leptospirosis control is very important. OmpL1 is an immunogenic porin protein that could be of special significance in vaccination and serodiagnosis for leptospirosis. Three strains belonging to pathogenic L. interrogans were analyzed. The specific primers for proliferation of the ompL1 gene were designed. The amplified gene was cloned. In order to investigate the ompL1 nucleotide sequence and homological analysis of this gene, ompL1 genes cloned from standard vaccinal Leptospira serovars prevalent in Iran were sequenced and cloned. PCR amplification of the ompL1 gene using the designed primers resulted in a 963 bp ompL1 gene product. The PCR based on the ompL1 gene detected all pathogenic reference serovars of Leptospira spp. tested. Based on alignment and phylogenetic analysis, although the ompL1 nucleotide sequence was slightly different within three vaccinal serovars (100%-85% identity), amino acid alignment of the OmpL1 proteins revealed that there would be inconsiderable difference among them. The ompL1 gene of the three isolates was well conserved, differing only by a total of 6 bp and the proteins by 2 amino acids. The cloned gene could be further used for expression and recombinant OmpL1 as an efficient and conserved antigen, and may be a useful vaccine candidate against leptospirosis in our region.

IDENTIFICATION OF SALMONELLA SEROVARS ISOLATED DURING 2009-2016 IN TERNOPIL REGION, UKRAINE

Directory of Open Access Journals (Sweden)

Pokryshko O.V.

2017-06-01

Full Text Available Introduction. Salmonellosis is registered in all regions of the world. Relevance of salmonellosis is due its global distribution, increasing incidence, even in developed countries, frequent outbreaks. The most reports in different countries demonstrated that one of the common Salmonella serotypes isolated from food and environmental samples had been serovars Salmonella Enterica, Typhimurium. In Ukraine 7.3% of all acute diarrheal infections have been cases of salmonellosis. Although large Salmonella outbreaks usually attract media attention, 60–80% of all salmonellosis cases are not recognized as part of a known outbreak and are classified as sporadic cases, or are not diagnosed as such at all. Material & methods. The samples from cultured stool, bile samples, food and environment were inoculated in the Tryptic Soya Broth (TSB for the enrichment and detection of the bacteria. After 24 hours incubation, microorganisms were cultured on the MacConkey agar plates. Then biochemical and serological tests were performed to identify the serovars of the isolated Salmonella in Ternopil regional laboratory center, Ukraine.Results & discussion. Over the past 8 years the incidence of salmonellosis has varied between 8.41 3.3 cases per 100 thousand of population (35 - 90 cases. During this period, the lowest rate recorded in 2015 (3.3 cases per 100 thousand of population, the highest – in 2014. Analysis of morbidity has been shown that elevated levels of infection were due to outbreaks registrated in 2011 (the number of infected people was 23, in 2013 (53 infected people, in 2014 (67 infected people and in 2016 (16 infected people. In Ternopil region the dominant serovar of Salmonella spp. isolated from patients are S. enteritidis (56.8 - 93.5% of all cases of diseases and S. typhimurium (7.8 - 43.8% in last 8 years. Among the carriers circulate S.enteritidis, S. typhimurium – mainly (64,8% and 35.2% respectively. Not typical for Ternopil region

Human leptospirosis: occurrence of serovars of Leptospira spp. in the state of Minas Gerais, Brazil, from 2008 to 2012.

Science.gov (United States)

Oliveira, Marluce Aparecida Assunção; Leal, Élida Aparecida; Correia, Max Assunção; Serufo Filho, José Carlos; Dias, Ricardo Souza; Serufo, José Carlos

Leptospirosis is an infectious and acute disease caused by Leptospira spp. that have high epidemic potential. This study verified the main Leptospira spp. serovars detected by MAT from serum of patients with suspicion of leptospirosis from 2008 to 2012 in Minas Gerais State. The laboratory received sera from 4654 patients. All serum were screened by IgM-ELISA according to the manufacturer's instructions. Each sample reactive or indeterminate were tested against twenty-four serovars of Leptospira by MAT. In this study, 597 patients were classified as reactive on MAT. Only 301 patients were confirmed by laboratory test. It was not possible confirmation by laboratory diagnosis of 296 patients. Among the samples classified as reactive on MAT, 273 patients exhibited titers bigger than 800 for one or more serovars; seroconversion was detected in 28 cases. Percentage of 85.1% of the samples reactive on MAT corresponded to males, 39.4% corresponded to patients aged between 20 and 39 years old. The most common serovars found were Icterohaemorrhagiae, Andamana, Patoc, Tarassovi, Copenhageni, Hardjo and Australis. Concerning the samples that exhibited titers bigger than 800, serovar Icterohaemorrhagiae was also the most common, followed by Copenhageni, Andamana, Patoc, Tarassovi, Grippotyphosa and Canicola. In this study, 40% of the cases occurred to the metropolitan area, state capital and 34 neighboring towns. Our results show the possibly spreading serovars in Minas Gerais State and contribute to knowledge of human leptospirosis, aiming at improving the prevention, control of the disease, as well as the treatment of infected patients. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Immune response of chicken gut to natural colonization by gut microflora and to Salmonella enterica serovar enteritidis infection.

Science.gov (United States)

Crhanova, Magdalena; Hradecka, Helena; Faldynova, Marcela; Matulova, Marta; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

2011-07-01

In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut microbiota gradually increased from day 1 to day 19 of life and consisted of Proteobacteria and Firmicutes. For the first 3 days of life, chicken cecum was protected by increased expression of chicken β-defensins (i.e., gallinacins 1, 2, 4, and 6), expression of which dropped from day 4 of life. On the other hand, a transient increase in interleukin-8 (IL-8) and IL-17 expression could be observed in chicken cecum on day 4 of life, indicating physiological inflammation and maturation of the gut immune system. In agreement, the response of chickens infected with S. Enteritidis on days 1, 4, and 16 of life shifted from Th1 (characterized mainly by induction of gamma interferon [IFN-γ] and inducible nitric oxide synthase [iNOS]), observed in younger chickens, to Th17, observed in 16-day-old chickens (characterized mainly by IL-17 induction). Active modification of chicken gut microbiota in the future may accelerate or potentiate the maturation of the gut immune system and increase its resistance to infection with different pathogens.

Prevalence and characterization of Salmonella serovars isolated from oysters served raw in restaurants.

Science.gov (United States)

Brillhart, Crystal D; Joens, Lynn A

2011-06-01

To determine if Salmonella-contaminated oysters are reaching consumer tables, a survey of raw oysters served in eight Tucson restaurants was performed from October 2007 to September 2008. Salmonella spp. were isolated during 7 of the 8 months surveyed and were present in 1.2% of 2,281 oysters tested. This observed prevalence is lower than that seen in a previous study in which U.S. market oysters were purchased from producers at bays where oysters are harvested. To test whether the process of refrigerating oysters in restaurants for several days reduces Salmonella levels, oysters were artificially infected with Salmonella and kept at 4°C for up to 13 days. Direct plate counts of oyster homogenate showed that Salmonella levels within oysters did not decrease during refrigeration. Six different serovars of Salmonella enterica were found in the restaurant oysters, indicating multiple incidences of Salmonella contamination of U.S. oyster stocks. Of the 28 contaminated oysters, 12 (43%) contained a strain of S. enterica serovar Newport that matched by pulsed-field gel electrophoresis a serovar Newport strain seen predominantly in the study of bay oysters performed in 2002. The repeated occurrence of this strain in oyster surveys is concerning, since the strain was resistant to seven antimicrobials tested and thus presents a possible health risk to consumers of raw oysters.

The classification of Sejroe group serovars of Leptospira interrogans with monoclonal antibodies

NARCIS (Netherlands)

Terpstra, W. J.; Korver, H.; van Leeuwen, J.; Klatser, P. R.; Kolk, A. H.

1985-01-01

Using the hybridoma technique we produced monoclonal antibodies to serovars of Leptospira interrogans. We focussed on serovar hardjo which is an important pathogen for humans and animals, and on other serovars of the Sejroe group. With combinations of monoclonals, characteristic patterns of

Host-Nonspecific Iron Acquisition Systems and Virulence in the Zoonotic Serovar of Vibrio vulnificus

Science.gov (United States)

Pajuelo, David; Lee, Chung-Te; Roig, Francisco J.; Lemos, Manuel L.; Hor, Lien-I

2014-01-01

The zoonotic serovar of Vibrio vulnificus (known as biotype 2 serovar E) is the etiological agent of human and fish vibriosis. The aim of the present work was to discover the role of the vulnibactin- and hemin-dependent iron acquisition systems in the pathogenicity of this zoonotic serovar under the hypothesis that both are host-nonspecific virulence factors. To this end, we selected three genes for three outer membrane receptors (vuuA, a receptor for ferric vulnibactin, and hupA and hutR, two hemin receptors), obtained single and multiple mutants as well as complemented strains, and tested them in a series of in vitro and in vivo assays, using eels and mice as animal models. The overall results confirm that hupA and vuuA, but not hutR, are host-nonspecific virulence genes and suggest that a third undescribed host-specific plasmid-encoded system could also be used by the zoonotic serovar in fish. hupA and vuuA were expressed in the internal organs of the animals in the first 24 h of infection, suggesting that they may be needed to achieve the population size required to trigger fatal septicemia. vuuA and hupA were sequenced in strains representative of the genetic diversity of this species, and their phylogenies were reconstructed by multilocus sequence analysis of selected housekeeping and virulence genes as a reference. Given the overall results, we suggest that both genes might form part of the core genes essential not only for disease development but also for the survival of this species in its natural reservoir, the aquatic environment. PMID:24478087

Three case studies involving Leptospira interrogans serovar pomona infection in mixed farming units : case report

Directory of Open Access Journals (Sweden)

B. Gummow

1999-07-01

Full Text Available Three case studies involving Leptospira interrogans serovar pomona outbreaks within mixed farming systems in South Africa are described. On 2 farms, pigs constituted the main enterprise with cattle and sheep of secondary importance. On each of these 2 farms, abortion due to L. pomona in sows was confirmed by culture, and antibody titres to pomona were detected in cattle, sheep, horses and dogs. On the 3rd farm, a piggery was ofsecondary importance to cattle farming. Abortion and death in cows occurred on this farmand serology showed titres to various serovars, including pomona. L. pomona was also isolated from bovine urine, an aborted bovine foetus and kidneys from slaughtered pigs. This particular case study was regarded as clinically atypical in that adult Jersey cattle died of acute leptospirosis in a semiarid region of South Africa. In all 3 case studies, the poor management of pig effluent and of the drinking water and its sources played a pivotal role in the transmission of the disease. Inadequate vaccination of animals against Leptospira and poor record-keeping within the secondary farming enterprises were also contributing factors to the spread of leptospirosis.

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) for the characterisation of pathogenic leptospires: intra-serovar divergence, inter-serovar convergence, and evidence of attenuation in Leptospira reference collections.

Science.gov (United States)

Tulsiani, S M; Craig, S B; Graham, G C; Cobbold, R C; Dohnt, M F; Burns, M-A; Jansen, C C; Leung, L K-P; Field, H E; Smythe, L D

2010-07-01

High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) is a novel technology that has emerged as a possible method to characterise leptospires to serovar level. RAPD-HRM has recently been used to measure intra-serovar convergence between strains of the same serovar as well as inter-serovar divergence between strains of different serovars. The results indicate that intra-serovar heterogeneity and inter-serovar homogeneity may limit the application of RAPD-HRM in routine diagnostics. They also indicate that genetic attenuation of aged, high-passage-number isolates could undermine the use of RAPD-HRM or any other molecular technology. Such genetic attenuation may account for a general decrease seen in titres of rabbit hyperimmune antibodies over time. Before RAPD-HRM can be further advanced as a routine diagnostic tool, strains more representative of the wild-type serovars of a given region need to be identified. Further, RAPD-HRM analysis of reference strains indicates that the routine renewal of reference collections, with new isolates, may be needed to maintain the genetic integrity of the collections.

Arginine-dependent acid resistance in Salmonella enterica serovar Typhimurium

NARCIS (Netherlands)

Kieboom, J.; Abee, T.

2006-01-01

Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid

Arbitrarily primed PCR- A rapid and simple method for typing of leptospiral serovars

Directory of Open Access Journals (Sweden)

Ramadass P

2002-01-01

Full Text Available PURPOSE: To investigate the use of arbitrarily primed polymerase chain reaction (AP-PCR for typing of leptospiral serovars. METHODS: AP-PCR was adopted for identification of laboratory strains of leptospires and leptospiral cultures at serovar level. A primer of 12 bp was used for amplifying DNA of 13 laboratory strains of leptospires as well as culture pellets of leptospires. RESULTS: Each serovar produced distinct DNA fingerprint which was characteristic for each serovar. These patterns were used for typing of 81 serum culture samples obtained from human leptospiral cases. Of these samples, 39 could be typed based on AP-PCR fingerprints belonging to serovars autumnalis, pomona, canicola, javanica, icterohaemorrhagiae, patoc and pyrogenes. These results were confirmed by RAPD fingerprinting of the DNA samples of the respective leptospiral serovars after culturing -FNx01them in EMJH media. One of the important findings of this work was that straight culture sample could be used for AP-PCR assay, without purification of DNA. By having more number of AP-PCR reference fingerprints, more serovars could be typed. CONCLUSIONS: AP-PCR technique provides great potential for simple and rapid identification of leptospires at serovar level, which could be useful in molecular epidemiological studies of leptospirosis.

Proteome analysis of serovars Typhimurium and Pullorum of Salmonella enterica subspecies I

Directory of Open Access Journals (Sweden)

Begum Shajna

2005-07-01

Full Text Available Abstract Background Salmonella enterica subspecies I includes several closely related serovars which differ in host ranges and ability to cause disease. The basis for the diversity in host range and pathogenic potential of the serovars is not well understood, and it is not known how host-restricted variants appeared and what factors were lost or acquired during adaptations to a specific environment. Differences apparent from the genomic data do not necessarily correspond to functional proteins and more importantly differential regulation of otherwise identical gene content may play a role in the diverse phenotypes of the serovars of Salmonella. Results In this study a comparative analysis of the cytosolic proteins of serovars Typhimurium and Pullorum was performed using two-dimensional gel electrophoresis and the proteins of interest were identified using mass spectrometry. An annotated reference map was created for serovar Typhimurium containing 233 entries, which included many metabolic enzymes, ribosomal proteins, chaperones and many other proteins characteristic for the growing cell. The comparative analysis of the two serovars revealed a high degree of variation amongst isolates obtained from different sources and, in some cases, the variation was greater between isolates of the same serovar than between isolates with different sero-specificity. However, several serovar-specific proteins, including intermediates in sulphate utilisation and cysteine synthesis, were also found despite the fact that the genes encoding those proteins are present in the genomes of both serovars. Conclusion Current microbial proteomics are generally based on the use of a single reference or type strain of a species. This study has shown the importance of incorporating a large number of strains of a species, as the diversity of the proteome in the microbial population appears to be significantly greater than expected. The characterisation of a diverse selection of

A novel Salmonella serovar isolated from Peregrine Falcon (Falco peregrinus nestlings in Sweden: Salmonella enterica enterica serovar Pajala (Salmonella Pajala

Directory of Open Access Journals (Sweden)

Jorge Hernández

2012-08-01

Full Text Available A novel Salmonella serovar was isolated from Peregrine falcon (Falco peregrinus nestlings in northern Sweden in 2006. Three isolates of the same clone was retrieved from three falcon siblings and characterized as Salmonella enterica sub-species enterica: O-phase 13, 23:-: e, n, z 15 and the H-phase was not present. We propose the geographical name Salmonella enterica, sub-species enterica serovar Pajala to this novel Salmonella.

Immune Response of Chicken Gut to Natural Colonization by Gut Microflora and to Salmonella enterica Serovar Enteritidis Infection ▿

Science.gov (United States)

Crhanova, Magdalena; Hradecka, Helena; Faldynova, Marcela; Matulova, Marta; Havlickova, Hana; Sisak, Frantisek; Rychlik, Ivan

2011-01-01

In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut microbiota gradually increased from day 1 to day 19 of life and consisted of Proteobacteria and Firmicutes. For the first 3 days of life, chicken cecum was protected by increased expression of chicken β-defensins (i.e., gallinacins 1, 2, 4, and 6), expression of which dropped from day 4 of life. On the other hand, a transient increase in interleukin-8 (IL-8) and IL-17 expression could be observed in chicken cecum on day 4 of life, indicating physiological inflammation and maturation of the gut immune system. In agreement, the response of chickens infected with S. Enteritidis on days 1, 4, and 16 of life shifted from Th1 (characterized mainly by induction of gamma interferon [IFN-γ] and inducible nitric oxide synthase [iNOS]), observed in younger chickens, to Th17, observed in 16-day-old chickens (characterized mainly by IL-17 induction). Active modification of chicken gut microbiota in the future may accelerate or potentiate the maturation of the gut immune system and increase its resistance to infection with different pathogens. PMID:21555397

Genome-wide methylation patterns in Salmonella enterica Subsp. enterica Serovars.

Directory of Open Access Journals (Sweden)

Cary Pirone-Davies

Full Text Available The methylation of DNA bases plays an important role in numerous biological processes including development, gene expression, and DNA replication. Salmonella is an important foodborne pathogen, and methylation in Salmonella is implicated in virulence. Using single molecule real-time (SMRT DNA-sequencing, we sequenced and assembled the complete genomes of eleven Salmonella enterica isolates from nine different serovars, and analysed the whole-genome methylation patterns of each genome. We describe 16 distinct N6-methyladenine (m6A methylated motifs, one N4-methylcytosine (m4C motif, and one combined m6A-m4C motif. Eight of these motifs are novel, i.e., they have not been previously described. We also identified the methyltransferases (MTases associated with 13 of the motifs. Some motifs are conserved across all Salmonella serovars tested, while others were found only in a subset of serovars. Eight of the nine serovars contained a unique methylated motif that was not found in any other serovar (most of these motifs were part of Type I restriction modification systems, indicating the high diversity of methylation patterns present in Salmonella.

Development of the leptospirosis by experimental infection in hamsters (Mesocricetus auratus with Leptospira interrogans serovar Canicola, strain LO4, by intact and scratched skin exposures

Directory of Open Access Journals (Sweden)

Carolina de Sousa Américo Batista

2010-10-01

Full Text Available The establishment and evolution of leptospirosis in hamster (Mesocricetus auratus by experimental infection with Leptospira interrogans serovar Canicola, LO4 strain, by intact and scratched skin exposures, having as control the intraperitoneal route, were evaluated. Hundred-twenty female hamsters distributed in two groups according to inoculation route (intact and scratched skin were used. Infectious inoculum was constituted by a pure culture of L. interrogans serovar Canicola (strain LO4, isolated from liver from a slaughtered swine in Londrina, Paraná state and typified by agglutinins adsortion technique with monoclonal antibody kit at the Royal Tropical Institute, Amsterdam, the Netherlands. The animals were observed twice a day during 21 days. Animals that died were necropsied and kidneys, liver, genital tract (uterus and ovaries and brain were aseptically collected. On the 21st post-inoculation day, surviving animals were euthanized. In these animals, serum samples were also collected by cardiac puncture to antileptospires agglutinins research using microscopic agglutination test (MAT. Fresh direct microscopy and microbiological culture were used for the detection of leptospires. Scratched skin route induced larger lethality when compared to intact skin route, with establishment and evolution of leptospirosis. On the other hand, intact skin route induced renal and/or genital carrier state more frequently. LO4 strain presented low immunogenic power, characterized by soroconversion at the MAT in only one inoculated animal.

Attenuated Salmonella choleraesuis-mediated RNAi targeted to conserved regions against foot-and-mouth disease virus in guinea pigs and swine

Science.gov (United States)

Cong, Wei; Jin, Hong; Jiang, Chengda; Yan, Weiyao; Liu, Mingqiu; Chen, Jiulian; Zuo, Xiaoping; Zheng, Zhaoxin

2010-01-01

In this study, specific sequences within three genes (3D, VP4 and 2B) of the foot-and-mouth disease virus (FMDV) genome were determined to be effective RNAi targets. These sequences are highly conserved among different serotype viruses based on sequence analysis. Small interfering RNA (siRNA)-expressing plasmids (p3D-NT19, p3D-NT56, pVP4-NT19, pVP4-NT65 and p2B-NT25) were constructed to express siRNA targeting 3D, VP4 and 2B, respectively. The antiviral potential of these siRNA for various FMDV isolates was investigated in baby hamster kidney (BHK-21) cells and suckling mice. The results show that these siRNA inhibited virus yield 10- to 300-fold for different FMDV isolates of serotype O and serotype Asia I at 48 h post infection in BHK-21 cells compared to control cells. In suckling mice, p3D-NT56 and p2B-NT25 delayed the death of mice. Twenty percent to 40% of the animals that received a single siRNA dose survived 5 days post infection with serotype O or serotype Asia I. We used an attenuated Salmonella choleraesuis (C500) vaccine strain, to carry the plasmid that expresses siRNA directed against the polymerase gene 3D (p3D-NT56) of FMDV. We used guinea pigs to evaluate the inhibitory effects of recombinant S. cho (p3D-NT56/S. cho) on FMDV infection. The results show that 80% of guinea pigs inoculated with 109 CFU of p3D-NT56/S. cho and challenged 36 h later with 50 ID50 of homologous FMDV were protected. We also measured the antiviral activity of p3D-NT56/S. cho in swine. The results indicate that 100% of the animals treated with 5 × 109 CFU of p3D-NT56/S. cho were protected in 9 days. PMID:20167192

Survival and transmission of Salmonella enterica serovar typhimurium in an outdoor organic pig farming environment

DEFF Research Database (Denmark)

Jensen, Annette Nygaard; Dalsgaard, Anders; Stockmarr, Anders

2006-01-01

It was investigated how organic rearing conditions influence the Salmonella enterica infection dynamics in pigs and whether Salmonella persists in the paddock environment. Pigs inoculated with S. enterica serovar Typhimurium were grouped with Salmonella-negative tracer pigs. Bacteriological...... the seroprevalence. Salmonella persisted in the paddock environment, as Salmonella was isolated from 46% of soil and water samples (n = 294). After removal of pigs, Salmonella was found in soil samples for up to. 5 weeks and in shelter huts during the entire test period (7 weeks). Subsequent introduction...... of Salmonella-negative pigs into four naturally Salmonella-contaminated paddocks caused Salmonella infections of pigs in two paddocks. In one of these paddocks, all tracer pigs (n = 10) became infected, coinciding with a previous high Salmonella infection rate and high Salmonella excretion level. Our results...

Characterization of Isolates of Salmonella enterica Serovar Stanley, a Serovar Endemic to Asia and Associated with Travel

Science.gov (United States)

Le Hello, Simon; Bortolaia, Valeria; Pulsrikarn, Chaiwat; Nielsen, Eva Møller; Pornruangmong, Srirat; Chaichana, Phattharaporn; Svendsen, Christina Aaby; Weill, François-Xavier; Aarestrup, Frank M.

2012-01-01

Salmonella enterica serovar Stanley (S. Stanley) is a common serovar in Southeast Asia and was the second most common serovar implicated in human salmonellosis in Thailand in the years 2002 to 2007. In contrast, this serovar is relatively uncommon in Europe. The objective of this study was to characterize a collection of S. Stanley strains isolated from Thai (n = 62), Danish (n = 39), and French (n = 24) patients to gain a broader understanding of the genetic diversity, population dynamics, and susceptibility to antimicrobials. All isolates were characterized by pulsed-field gel electrophoresis and antimicrobial susceptibility testing. The molecular mechanisms of resistance to extended-spectrum cephalosporins and plasmid-mediated resistance to quinolones were characterized by PCR and sequencing. Plasmid profiling, replicon typing, and microarray analysis were used to characterize the genetic mechanisms of antimicrobial resistance in 10 extended-spectrum cephalosporinase-producing isolates. Considerable genetic diversity was observed among the isolates characterized with 91 unique XbaI pulsed-field gel electrophoresis (PFGE) patterns, including 17 distinct clusters consisting of two to seven indistinguishable isolates. We found some of the S. Stanley isolates isolated from patients in Europe were acquired during travel to Southeast Asia, including Thailand. The presence of multiple plasmid lineages carrying the extended-spectrum cephalosporinase-encoding blaCMY-2 gene in S. Stanley isolates from the central part of Thailand was confirmed. Our results emphasize that Thai authorities, as well as authorities in other countries lacking prudent use of antimicrobials, should improve the ongoing efforts to regulate antimicrobial use in agriculture and in clinical settings to limit the spread of multidrug-resistant Salmonella isolates and plasmids among humans and pigs in Thailand and abroad. PMID:22205822

The Vi capsular polysaccharide enables Salmonella enterica serovar typhi to evade microbe-guided neutrophil chemotaxis.

Directory of Open Access Journals (Sweden)

Tamding Wangdi

2014-08-01

Full Text Available Salmonella enterica serovar Typhi (S. Typhi causes typhoid fever, a disseminated infection, while the closely related pathogen S. enterica serovar Typhimurium (S. Typhimurium is associated with a localized gastroenteritis in humans. Here we investigated whether both pathogens differ in the chemotactic response they induce in neutrophils using a single-cell experimental approach. Surprisingly, neutrophils extended chemotactic pseudopodia toward Escherichia coli and S. Typhimurium, but not toward S. Typhi. Bacterial-guided chemotaxis was dependent on the presence of complement component 5a (C5a and C5a receptor (C5aR. Deletion of S. Typhi capsule biosynthesis genes markedly enhanced the chemotactic response of neutrophils in vitro. Furthermore, deletion of capsule biosynthesis genes heightened the association of S. Typhi with neutrophils in vivo through a C5aR-dependent mechanism. Collectively, these data suggest that expression of the virulence-associated (Vi capsular polysaccharide of S. Typhi obstructs bacterial-guided neutrophil chemotaxis.

Interaction of Saccharomyces boulardii with Salmonella enterica serovar Typhimurium protects mice and modifies T84 cell response to the infection.

Directory of Open Access Journals (Sweden)

Flaviano S Martins

Full Text Available BACKGROUND: Salmonella pathogenesis engages host cells in two-way biochemical interactions: phagocytosis of bacteria by recruitment of cellular small GTP-binding proteins induced by the bacteria, and by triggering a pro-inflammatory response through activation of MAPKs and nuclear translocation of NF-kappaB. Worldwide interest in the use of functional foods containing probiotic bacteria for health promotion and disease prevention has increased significantly. Saccharomyces boulardii is a non-pathogenic yeast used as a probiotic in infectious diarrhea. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we reported that S. boulardii (Sb protected mice from Salmonella enterica serovar Typhimurium (ST-induced death and prevented bacterial translocation to the liver. At a molecular level, using T84 human colorectal cancer cells, we demonstrate that incubation with Sb before infection totally abolished Salmonella invasion. This correlates with a decrease of activation of Rac1. Sb preserved T84 barrier function and decreased ST-induced IL-8 synthesis. This anti-inflammatory effect was correlated with an inhibitory effect of Sb on ST-induced activation of the MAPKs ERK1/2, p38 and JNK as well as on activation of NF-kappaB. Electron and confocal microscopy experiments showed an adhesion of bacteria to yeast cells, which could represent one of the mechanisms by which Sb exerts its protective effects. CONCLUSIONS: Sb shows modulating effects on permeability, inflammation, and signal transduction pathway in T84 cells infected by ST and an in vivo protective effect against ST infection. The present results also demonstrate that Sb modifies invasive properties of Salmonella.

Interaction of Saccharomyces boulardii with Salmonella enterica Serovar Typhimurium Protects Mice and Modifies T84 Cell Response to the Infection

Science.gov (United States)

Martins, Flaviano S.; Dalmasso, Guillaume; Arantes, Rosa M. E.; Doye, Anne; Lemichez, Emmanuel; Lagadec, Patricia; Imbert, Veronique; Peyron, Jean-François; Rampal, Patrick; Nicoli, Jacques R.; Czerucka, Dorota

2010-01-01

Background Salmonella pathogenesis engages host cells in two-way biochemical interactions: phagocytosis of bacteria by recruitment of cellular small GTP-binding proteins induced by the bacteria, and by triggering a pro-inflammatory response through activation of MAPKs and nuclear translocation of NF-κB. Worldwide interest in the use of functional foods containing probiotic bacteria for health promotion and disease prevention has increased significantly. Saccharomyces boulardii is a non-pathogenic yeast used as a probiotic in infectious diarrhea. Methodology/Principal Findings In this study, we reported that S. boulardii (Sb) protected mice from Salmonella enterica serovar Typhimurium (ST)-induced death and prevented bacterial translocation to the liver. At a molecular level, using T84 human colorectal cancer cells, we demonstrate that incubation with Sb before infection totally abolished Salmonella invasion. This correlates with a decrease of activation of Rac1. Sb preserved T84 barrier function and decreased ST-induced IL-8 synthesis. This anti-inflammatory effect was correlated with an inhibitory effect of Sb on ST-induced activation of the MAPKs ERK1/2, p38 and JNK as well as on activation of NF-κB. Electron and confocal microscopy experiments showed an adhesion of bacteria to yeast cells, which could represent one of the mechanisms by which Sb exerts its protective effects. Conclusions Sb shows modulating effects on permeability, inflammation, and signal transduction pathway in T84 cells infected by ST and an in vivo protective effect against ST infection. The present results also demonstrate that Sb modifies invasive properties of Salmonella. PMID:20111723

Occurrence of purulent arthritis broilers vertically infected with Salmonella enterica serovar Enteritidis in Korea.

Science.gov (United States)

Oh, J-Y; Kang, M-S; An, B-K; Song, E-A; Kwon, J-H; Kwon, Y-K

2010-10-01

Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) has been associated with morbidity and mortality in broiler chickens worldwide. The present study described purulent arthritis of broilers infected with Salmonella Enteritidis and investigated antibiograms and genetic characteristics of Salmonella Enteritidis isolates from epidemiologically related properties such as a hatchery and breeder farm in an attempt to elucidate the source of contamination. Clinical disease and mortality were observed in the affected broiler flock. Mortality was 5.8% until 12 d of age. The birds typically showed lameness with moderately swollen hock joints and footpads. The most prevalent lesions were severely purulent arthritis with polyserositis. Histopathology revealed moderate to severe inflammation in the synovial membrane of leg joints and visceral organs. When the antimicrobial susceptibility test was performed against 7 isolates of Salmonella Enteritidis from broilers, and relevant hatchery and breeder farms by the disk diffusion method using 18 antimicrobial agents, isolates from broiler and breeder farms had the same antibiogram characterized by multiple drug resistance to ampicillin, ceftiofur, cephalothin, gentamycin, nalidixic acid, streptomycin, sulfisoxazole, and tetracycline, whereas isolates from the hatchery were differently resistant to only nalidixic acid. Through the genetic analysis with pulsed-field gel electrophoresis using the restriction enzyme XbaI, Salmonella Enteritidis isolates from both broiler and breeder farms also showed the same PFGE pattern compared with the hatchery isolates resistant to nalidixic acid. As a result, the same PFGE profiles and antibiogram patterns among isolates from broilers and breeder farms provided direct evidence of vertical Salmonella Enteritidis transmission from the contaminated breeder farm to commercial broiler.

MARTX Toxin in the Zoonotic Serovar of Vibrio vulnificus Triggers an Early Cytokine Storm in Mice

Directory of Open Access Journals (Sweden)

Celia Murciano

2017-07-01

Full Text Available Vibrio vulnificus biotype 2-serovar E is a zoonotic clonal complex that can cause death by sepsis in humans and fish. Unlike other biotypes, Bt2 produces a unique type of MARTXVv (Multifunctional-Autoprocessive-Repeats-in-Toxin; RtxA13, which is encoded by a gene duplicated in the pVvBt2 plasmid and chromosome II. In this work, we analyzed the activity of this toxin and its role in human sepsis by performing in vitro, ex vivo, and in vivo assays. First, we demonstrated that the ACD domain, present exclusively in this toxin variant, effectively has an actin-cross-linking activity. Second, we determined that the whole toxin caused death of human endotheliocytes and monocytes by lysis and apoptosis, respectively. Finally, we tested the hypothesis that RtxA13 contributes to human death caused by this zoonotic serovar by triggering an early cytokine storm in blood. To this end, we used a Bt2-SerE strain (R99 together with its rtxA13 deficient mutant, and a Bt1 strain (YJ016 producing RtxA11 (the most studied MARTXVv together with its rtxA11 deficient mutant, as controls. Our results showed that RtxA13 was essential for virulence, as R99ΔΔrtxA13 was completely avirulent in our murine model of infection, and that R99, but not strain YJ016, induced an early, strong and dysregulated immune response involving the up-regulation of a high number of genes. This dysregulated immune response was directly linked to RtxA13. Based on these results and those obtained ex vivo (human blood, we propose a model of infection for the zoonotic serovar of V. vulnificus, in which RtxA13 would act as a sepsis-inducing toxin.

Development of a multiplex polymerase chain reaction protocol for the simultaneous detection of Salmonella enterica serovar Typhi and Class 1 integron

Directory of Open Access Journals (Sweden)

Juthika Mandal

2014-09-01

Full Text Available Objective: To develop a multiplex polymerase chain reaction (PCR protocol for the simultaneous detection of Salmonella enterica serovar Typhi (S. Typhi and Class 1 integron, so as to aid rapid diagnosis of S. Typhi cases and help in the selection of treatment options based on the presence of the Class 1 integron that can carry resistance cassettes to a range of antibiotics. Methods: PCR for amplification of specific regions was done using fliC-d and intl primers and agarose gel electrophoresis was used for resolution of PCR products. Results: The fliC-d primer (S. Typhi specific amplified a 587 bp region and the intl primer (Class 1 integron specific amplified two bands approximately 500 and 550 bps. The developed method was specific for S. Typhi and did not amplify any products with Salmonella enterica serovar Typhimurium ATCC 14028, Salmonella enterica serovar Paratyphi and Escherichia coli O157:H7. Conclusions: The developed multiplex PCR protocol can be used for rapid diagnosis and aid in proper treatment strategies for patients infected with S. Typhi.

Pseudogene accumulation in the evolutionary histories of Salmonella enterica serovars Paratyphi A and Typhi

Directory of Open Access Journals (Sweden)

White Brian

2009-01-01

Full Text Available Abstract Background Of the > 2000 serovars of Salmonella enterica subspecies I, most cause self-limiting gastrointestinal disease in a wide range of mammalian hosts. However, S. enterica serovars Typhi and Paratyphi A are restricted to the human host and cause the similar systemic diseases typhoid and paratyphoid fever. Genome sequence similarity between Paratyphi A and Typhi has been attributed to convergent evolution via relatively recent recombination of a quarter of their genomes. The accumulation of pseudogenes is a key feature of these and other host-adapted pathogens, and overlapping pseudogene complements are evident in Paratyphi A and Typhi. Results We report the 4.5 Mbp genome of a clinical isolate of Paratyphi A, strain AKU_12601, completely sequenced using capillary techniques and subsequently checked using Illumina/Solexa resequencing. Comparison with the published genome of Paratyphi A ATCC9150 revealed the two are collinear and highly similar, with 188 single nucleotide polymorphisms and 39 insertions/deletions. A comparative analysis of pseudogene complements of these and two finished Typhi genomes (CT18, Ty2 identified several pseudogenes that had been overlooked in prior genome annotations of one or both serovars, and identified 66 pseudogenes shared between serovars. By determining whether each shared and serovar-specific pseudogene had been recombined between Paratyphi A and Typhi, we found evidence that most pseudogenes have accumulated after the recombination between serovars. We also divided pseudogenes into relative-time groups: ancestral pseudogenes inherited from a common ancestor, pseudogenes recombined between serovars which likely arose between initial divergence and later recombination, serovar-specific pseudogenes arising after recombination but prior to the last evolutionary bottlenecks in each population, and more recent strain-specific pseudogenes. Conclusion Recombination and pseudogene-formation have been

Detection of Salmonella enterica Serovar Typhimurium from Avians Using Multiplex-PCR

Directory of Open Access Journals (Sweden)

Alireza Talebi

2011-09-01

Full Text Available Abstract Salmonella enterica serovar Typhimurium and S.enterica serovar Enteritidis are the most frequently isolated serovars from food-borne diseases throughout the world. According to their antigenic profiles, salmonella shows different disease syndromes and host specificities. It is necessary and important to discriminate salmonella serovars from each other in order to ensure that each pathogen and its epidemiology are correctly recognized. Many PCR-based methods have been developed to identify salmonella serovars. The objective of present study was to identify S. Typhimurium in avians from different regions including: North, Northwest and capital city (Tehran of Iran. Also in this research, the quality of CHROMagar™ Salmonella medium (CAS medium in veterinary medicine was evaluated. The results of present study showed that out of 1870 intestine samples, fifty two S. Typhimurium including broiler (n=13, layer (n=12, duck (n=5, goose (n=5, sparrow (n=8, canary (n=3, pigeon (n=5 and African grey parrot (n=1 were identified using serotyping as well as multiplex-PCR. In conclusion, important measures must be taken on prevention and propagation of S. Typhimurium among avians. CHROMagar™ Salmonella medium has high levels of sensitivity and specificity and reduced the time to final identification of salmonella spp. in comparison with biochemical tests.

Genome-wide screen for salmonella genes required for long-term systemic infection of the mouse.

Directory of Open Access Journals (Sweden)

2006-02-01

Full Text Available A microarray-based negative selection screen was performed to identify Salmonella enterica serovar Typhimurium (serovar Typhimurium genes that contribute to long-term systemic infection in 129X1/SvJ (Nramp1(r mice. A high-complexity transposon-mutagenized library was used to infect mice intraperitoneally, and the selective disappearance of mutants was monitored after 7, 14, 21, and 28 d postinfection. One hundred and eighteen genes were identified to contribute to serovar Typhimurium infection of the spleens of mice by 28 d postinfection. The negatively selected mutants represent many known aspects of Salmonella physiology and pathogenesis, although the majority of the identified genes are of putative or unknown function. Approximately 30% of the negatively selected genes correspond to horizontally acquired regions such as those within Salmonella pathogenicity islands (SPI 1-5, prophages (Gifsy-1 and -2 and remnant, and the pSLT virulence plasmid. In addition, mutations in genes responsible for outer membrane structure and remodeling, such as LPS- and PhoP-regulated and fimbrial genes, were also selected against. Competitive index experiments demonstrated that the secreted SPI2 effectors SseK2 and SseJ as well as the SPI4 locus are attenuated relative to wild-type bacteria during systemic infection. Interestingly, several SPI1-encoded type III secretion system effectors/translocases are required by serovar Typhimurium to establish and, unexpectedly, to persist systemically, challenging the present description of Salmonella pathogenesis. Moreover, we observed a progressive selection against serovar Typhimurium mutants based upon the duration of the infection, suggesting that different classes of genes may be required at distinct stages of infection. Overall, these data indicate that Salmonella long-term systemic infection in the mouse requires a diverse repertoire of virulence factors. This diversity of genes presumably reflects the fact that

SadA, a trimeric autotransporter from Salmonella enterica serovar Typhimurium, can promote biofilm formation and provides limited protection against infection.

Science.gov (United States)

Raghunathan, Dhaarini; Wells, Timothy J; Morris, Faye C; Shaw, Robert K; Bobat, Saeeda; Peters, Sarah E; Paterson, Gavin K; Jensen, Karina Tveen; Leyton, Denisse L; Blair, Jessica M A; Browning, Douglas F; Pravin, John; Flores-Langarica, Adriana; Hitchcock, Jessica R; Moraes, Claudia T P; Piazza, Roxane M F; Maskell, Duncan J; Webber, Mark A; May, Robin C; MacLennan, Calman A; Piddock, Laura J; Cunningham, Adam F; Henderson, Ian R

2011-11-01

Salmonella enterica is a major cause of morbidity worldwide and mortality in children and immunocompromised individuals in sub-Saharan Africa. Outer membrane proteins of Salmonella are of significance because they are at the interface between the pathogen and the host, they can contribute to adherence, colonization, and virulence, and they are frequently targets of antibody-mediated immunity. In this study, the properties of SadA, a purported trimeric autotransporter adhesin of Salmonella enterica serovar Typhimurium, were examined. We demonstrated that SadA is exposed on the Salmonella cell surface in vitro and in vivo during infection of mice. Expression of SadA resulted in cell aggregation, biofilm formation, and increased adhesion to human intestinal Caco-2 epithelial cells. Immunization of mice with folded, full-length, purified SadA elicited an IgG response which provided limited protection against bacterial challenge. When anti-SadA IgG titers were enhanced by administering alum-precipitated protein, a modest additional protection was afforded. Therefore, despite SadA having pleiotropic functions, it is not a dominant, protective antigen for antibody-mediated protection against Salmonella.

Transcriptional profiling avian beta-defensins in chicken oviduct epithelial cells before and after infection with Salmonella enterica serovar Enteritidis

Directory of Open Access Journals (Sweden)

Bailey R Hartford

2009-07-01

Full Text Available Abstract Background Salmonella enterica serovar Enteritidis (SE colonizes the ovary and oviduct of chickens without causing overt clinical signs which can lead to SE-contamination of the content and membrane of shell-eggs as well as hatchery eggs. The organism utilizes the Salmonella Pathogenicity Island-2 encoded type III secretion system (T3SS-2 to promote persistence in the oviduct of laying hens. In this study, reverse transcriptase-polymerase chain reaction (RT-PCR was carried out to determine the expression profiles of 14 known avian beta defensins (AvBDs in primary chicken oviduct epithelial cells (COEC before and after infections with a wild type SE strain and T3SS mutant SE strains carrying an inactivated sipA or pipB gene. Results Based on the expression levels in uninfected COEC, AvBDs can be loosely grouped into three categories with AvBD4-5 and AvBD9-12 being constitutively expressed at high levels; AvBD1, AvBD3, and AvBD13-14 at moderate levels; and AvBD2 and AvBD6-8 at minimal levels. Infection with the wild type SE strain temporarily repressed certain highly expressed AvBDs and induced the expression of minimally expressed AvBDs. The pipB mutant, compared to the wild type strain, had reduced suppressive effect on the expression of highly expressed AvBDs. Moreover, the pipB mutant elicited significantly higher levels of the minimally expressed AvBDs than the wild type SE or the sipA mutant did. Conclusion Chicken oviduct epithelial cells express most of the known AvBD genes in response to SE infection. PipB, a T3SS-2 effector protein, plays a role in dampening the β-defensin arm of innate immunity during SE invasion of chicken oviduct epithelium.

Transcriptional profiling avian beta-defensins in chicken oviduct epithelial cells before and after infection with Salmonella enterica serovar Enteritidis.

Science.gov (United States)

Ebers, Katie L; Zhang, C Yan; Zhang, M Zhenyu; Bailey, R Hartford; Zhang, Shuping

2009-07-30

Salmonella enterica serovar Enteritidis (SE) colonizes the ovary and oviduct of chickens without causing overt clinical signs which can lead to SE-contamination of the content and membrane of shell-eggs as well as hatchery eggs. The organism utilizes the Salmonella Pathogenicity Island-2 encoded type III secretion system (T3SS-2) to promote persistence in the oviduct of laying hens. In this study, reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out to determine the expression profiles of 14 known avian beta defensins (AvBDs) in primary chicken oviduct epithelial cells (COEC) before and after infections with a wild type SE strain and T3SS mutant SE strains carrying an inactivated sipA or pipB gene. Based on the expression levels in uninfected COEC, AvBDs can be loosely grouped into three categories with AvBD4-5 and AvBD9-12 being constitutively expressed at high levels; AvBD1, AvBD3, and AvBD13-14 at moderate levels; and AvBD2 and AvBD6-8 at minimal levels. Infection with the wild type SE strain temporarily repressed certain highly expressed AvBDs and induced the expression of minimally expressed AvBDs. The pipB mutant, compared to the wild type strain, had reduced suppressive effect on the expression of highly expressed AvBDs. Moreover, the pipB mutant elicited significantly higher levels of the minimally expressed AvBDs than the wild type SE or the sipA mutant did. Chicken oviduct epithelial cells express most of the known AvBD genes in response to SE infection. PipB, a T3SS-2 effector protein, plays a role in dampening the beta-defensin arm of innate immunity during SE invasion of chicken oviduct epithelium.

Protective effect of Lactobacillus casei strain Shirota against lethal infection with multi-drug resistant Salmonella enterica serovar Typhimurium DT104 in mice.

Science.gov (United States)

Asahara, T; Shimizu, K; Takada, T; Kado, S; Yuki, N; Morotomi, M; Tanaka, R; Nomoto, K

2011-01-01

The anti-infectious activity of lactobacilli against multi-drug resistant Salmonella enterica serovar Typhimurium DT104 (DT104) was examined in a murine model of an opportunistic antibiotic-induced infection. Explosive intestinal growth and subsequent lethal extra-intestinal translocation after oral infection with DT104 during fosfomycin (FOM) administration was significantly inhibited by continuous oral administration of Lactobacillus casei strain Shirota (LcS), which is naturally resistant to FOM, at a dose of 10(8) colony-forming units per mouse daily to mice. Comparison of the anti-Salmonella activity of several Lactobacillus type strains with natural resistance to FOM revealed that Lactobacillus brevis ATCC 14869(T) , Lactobacillus plantarum ATCC 14917(T) , Lactobacillus reuteri JCM 1112(T) , Lactobacillus rhamnosus ATCC 7469(T) and Lactobacillus salivarius ATCC 11741(T) conferred no activity even when they obtained the high population levels almost similar to those of the effective strains such as LcS, Lact. casei ATCC 334(T) and Lactobacillus zeae ATCC 15820(T) . The increase in concentration of organic acids and maintenance of the lower pH in the intestine because of Lactobacillus colonization were correlated with the anti-infectious activity. Moreover, heat-killed LcS was not protective against the infection, suggesting that the metabolic activity of lactobacilli is important for the anti-infectious activity. These results suggest that certain lactobacilli in combination with antibiotics may be useful for prophylaxis against opportunistic intestinal infections by multi-drug resistant pathogens, such as DT104. Antibiotics such as FOM disrupt the metabolic activity of the intestinal microbiota that produce organic acids, and that only probiotic strains that are metabolically active in vivo should be selected to prevent intestinal infection when used clinically in combination with certain antibiotics. © 2010 The Authors. Journal of Applied Microbiology �

Complete genome sequence of Leptospira interrogans serovar Bratislava, strain PigK151

Science.gov (United States)

The genus Leptospira contains pathogens serologically classified into over 250 serovars, intermediate pathogens and saprophytes with genetic classification into 21 different species. Worldwide, leptospirosis is one of the most widespread zoonoses. L. interrogans serovar Bratislava has been isolated ...

Comparison of Chlamydia trachomatis serovar L2 growth in polarized genital epithelial cells grown in three-dimensional culture with non-polarized cells.

Science.gov (United States)

Dessus-Babus, Sophie; Moore, Cheryl G; Whittimore, Judy D; Wyrick, Priscilla B

2008-04-01

A common model for studying Chlamydia trachomatis and growing chlamydial stocks uses Lymphogranuloma venereum serovar L2 and non-polarized HeLa cells. However, recent publications indicate that the growth rate and progeny yields can vary considerably for a particular strain depending on the cell line/type used, and seem to be partially related to cell tropism. In the present study, the growth of invasive serovar L2 was compared in endometrial HEC-1B and endocervical HeLa cells polarized on collagen-coated microcarrier beads, as well as in HeLa cells grown in tissue culture flasks. Microscopy analysis revealed no difference in chlamydial attachment/entry patterns or in inclusion development throughout the developmental cycle between cell lines. Very comparable growth curves in both cell lines were also found using real-time PCR analysis, with increases in chlamydial DNA content of 400-500-fold between 2 and 36 h post-inoculation. Similar progeny yields with comparable infectivity were recovered from HEC-1B and HeLa cell bead cultures, and no difference in chlamydial growth was found in polarized vs. non-polarized HeLa cells. In conclusion, unlike other C. trachomatis strains such as urogenital serovar E, invasive serovar L2 grows equally well in physiologically different endometrial and endocervical environments, regardless of the host cell polarization state.

Complete genome sequence of Leptospira alstonii serovar room 22, strain GWTS#1

Science.gov (United States)

We report the complete genome sequence of Leptospira alstonii serovar room 22 strain GWTS#1. This is the first isolate of L. alstonii to be cultured from a mammal, in Western Europe, and represents a new serovar of pathogenic leptospires....

Neutral genomic microevolution of a recently emerged pathogen, Salmonella enterica serovar Agona.

Directory of Open Access Journals (Sweden)

Zhemin Zhou

2013-04-01

Full Text Available Salmonella enterica serovar Agona has caused multiple food-borne outbreaks of gastroenteritis since it was first isolated in 1952. We analyzed the genomes of 73 isolates from global sources, comparing five distinct outbreaks with sporadic infections as well as food contamination and the environment. Agona consists of three lineages with minimal mutational diversity: only 846 single nucleotide polymorphisms (SNPs have accumulated in the non-repetitive, core genome since Agona evolved in 1932 and subsequently underwent a major population expansion in the 1960s. Homologous recombination with other serovars of S. enterica imported 42 recombinational tracts (360 kb in 5/143 nodes within the genealogy, which resulted in 3,164 additional SNPs. In contrast to this paucity of genetic diversity, Agona is highly diverse according to pulsed-field gel electrophoresis (PFGE, which is used to assign isolates to outbreaks. PFGE diversity reflects a highly dynamic accessory genome associated with the gain or loss (indels of 51 bacteriophages, 10 plasmids, and 6 integrative conjugational elements (ICE/IMEs, but did not correlate uniquely with outbreaks. Unlike the core genome, indels occurred repeatedly in independent nodes (homoplasies, resulting in inaccurate PFGE genealogies. The accessory genome contained only few cargo genes relevant to infection, other than antibiotic resistance. Thus, most of the genetic diversity within this recently emerged pathogen reflects changes in the accessory genome, or is due to recombination, but these changes seemed to reflect neutral processes rather than Darwinian selection. Each outbreak was caused by an independent clade, without universal, outbreak-associated genomic features, and none of the variable genes in the pan-genome seemed to be associated with an ability to cause outbreaks.

Six new leptospiral serovars isolated from wild animals in Peru.

OpenAIRE

Liceras de Hidalgo, J L; Sulzer, K R

1984-01-01

Six new serovars of Leptospira interrogans were isolated from opossums (Didelphis marsupialis and Philander opossum) trapped in the Peruvian jungle. The proposed names, type strain designation, and serogroup of the serovars, respectively, were: huallaga, strain M-7, Djasiman serogroup; luis, strain M-6, Tarassovi serogroup; machiguenga, strain MMD-3, Icterohaemorrhagiae serogroup; rioja, strain MR-12, Bataviae serogroup; rupa rupa, strain M-3, Sejroe serogroup; and tingomaria, strain M-13, Cy...

A Unique Capsule Locus in the Newly Designated Actinobacillus pleuropneumoniae Serovar 16 and Development of a Diagnostic PCR Assay.

Science.gov (United States)

Bossé, Janine T; Li, Yanwen; Sárközi, Rita; Gottschalk, Marcelo; Angen, Øystein; Nedbalcova, Katerina; Rycroft, Andrew N; Fodor, László; Langford, Paul R

2017-03-01

Actinobacillus pleuropneumoniae causes pleuropneumonia, an economically significant lung disease of pigs. Recently, isolates of A. pleuropneumoniae that were serologically distinct from the previously characterized 15 serovars were described, and a proposal was put forward that they comprised a new serovar, serovar 16. Here we used whole-genome sequencing of the proposed serovar 16 reference strain A-85/14 to confirm the presence of a unique capsular polysaccharide biosynthetic locus. For molecular diagnostics, primers were designed from the capsule locus of strain A-85/14, and a PCR was formulated that differentiated serovar 16 isolates from all 15 known serovars and other common respiratory pathogenic/commensal bacteria of pigs. Analysis of the capsule locus of strain A-85/14 combined with the previous serological data show the existence of a sixteenth serovar-designated serovar 16-of A. pleuropneumoniae . Copyright © 2017 Bossé et al.

Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

Science.gov (United States)

Irani, Vida R; Lee, Sun-Hwa; Eckstein, Torsten M; Inamine, Julia M; Belisle, John T; Maslow, Joel N

2004-01-01

Background Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL) of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. Methods To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA) gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt) rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. Results In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. Conclusion We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH) resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis, biosynthesis, or drug

Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

Directory of Open Access Journals (Sweden)

Belisle John T

2004-09-01

Full Text Available Abstract Background Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. Methods To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. Results In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. Conclusion We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis

Leptospira interrogans serovar copenhageni harbors two lexA genes involved in SOS response.

Directory of Open Access Journals (Sweden)

Luciane S Fonseca

Full Text Available Bacteria activate a regulatory network in response to the challenges imposed by DNA damage to genetic material, known as the SOS response. This system is regulated by the RecA recombinase and by the transcriptional repressor lexA. Leptospira interrogans is a pathogen capable of surviving in the environment for weeks, being exposed to a great variety of stress agents and yet retaining its ability to infect the host. This study aims to investigate the behavior of L. interrogans serovar Copenhageni after the stress induced by DNA damage. We show that L. interrogans serovar Copenhageni genome contains two genes encoding putative LexA proteins (lexA1 and lexA2 one of them being potentially acquired by lateral gene transfer. Both genes are induced after DNA damage, but the steady state levels of both LexA proteins drop, probably due to auto-proteolytic activity triggered in this condition. In addition, seven other genes were up-regulated following UV-C irradiation, recA, recN, dinP, and four genes encoding hypothetical proteins. This set of genes is potentially regulated by LexA1, as it showed binding to their promoter regions. All these regions contain degenerated sequences in relation to the previously described SOS box, TTTGN 5CAAA. On the other hand, LexA2 was able to bind to the palindrome TTGTAN10TACAA, found in its own promoter region, but not in the others. Therefore, the L. interrogans serovar Copenhageni SOS regulon may be even more complex, as a result of LexA1 and LexA2 binding to divergent motifs. New possibilities for DNA damage response in Leptospira are expected, with potential influence in other biological responses such as virulence.

Antimicrobial susceptibility and serovars of Salmonella from chickens and humans in Ibadan, Nigeria

DEFF Research Database (Denmark)

Fashae, K; Ogunsola, F; Aarestrup, Frank Møller

2010-01-01

BACKGROUND: This study determines the prevalence and antibiotic resistance of Salmonella serovars from humans and chickens in Ibadan, Nigeria, in 2004-2007. METHODOLOGY: A total of 991 blood samples were collected from patients in 2004 to 2005 and 641 fecal samples were collected from poultry farms......% were (S. Typhi). The majority of serovars from humans were S. Enteritidis (33%), S. Dublin (18%), and S. Typhimurium (18%). Resistance to chloramphenicol, sulfamethoxazole, trimethoprim, and ampicillin ranged from 36% to 59% for the human isolates. Eight different serovars were obtained from chickens...

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

Science.gov (United States)

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

2000-01-01

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

Presence of antibodies against Leptospira serovars in Chaetophractus villosus (Mammalia, Dasypodidae), La Pampa province, Argentina.

Science.gov (United States)

Kin, Marta S; Brihuega, Bibiana; Fort, Marcelo; Delgado, Fernando; Bedotti, Daniel; Casanave, Emma B

2015-01-01

Leptospirosis is a zoonosis of worldwide distribution. The aim of this study was to examine the presence of antibodies against 21 Leptospira reactive serovars in Chaetophractus villosus in La Pampa province, Argentina, using the microscopic agglutination test (MAT). Pathologic changes compatible with leptospirosis and in situ detection of the agent by immunohistochemistry were studied in 24 and 3 individuals respectively. Only 35/150 (23.3%) serum samples had antibodies against Leptospira sp. Six percent of the samples reacted with serovar Canicola, 4.7% with serovar Castellonis, 1.3% with serovar Icterohemorrhagieae and 0.7% with serovar Hardjo. Sixteen (10.6%) serum samples agglutinated with Castellonis-Icterohemorrhagiae and Canicola-Castellonis serovars, both with 4.7%, and Canicola-Hardjo and Castellonis-Canicola-Icterohemorrhagiae both with 0.6%. Fourteen animals had variable degrees of lesions, which were more severe in animals with higher serological titers (3200), and Leptospira sp. was detected in 3 animals by immunohistochemistry. These results represent the first record of the presence of Leptospira in C. villosus in La Pampa. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Genome and transcriptome adaptation accompanying emergence of the definitive type 2 host-restricted Salmonella enterica serovar Typhimurium pathovar.

Science.gov (United States)

Kingsley, Robert A; Kay, Sally; Connor, Thomas; Barquist, Lars; Sait, Leanne; Holt, Kathryn E; Sivaraman, Karthi; Wileman, Thomas; Goulding, David; Clare, Simon; Hale, Christine; Seshasayee, Aswin; Harris, Simon; Thomson, Nicholas R; Gardner, Paul; Rabsch, Wolfgang; Wigley, Paul; Humphrey, Tom; Parkhill, Julian; Dougan, Gordon

2013-08-27

Salmonella enterica serovar Typhimurium definitive type 2 (DT2) is host restricted to Columba livia (rock or feral pigeon) but is also closely related to S. Typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. DT2 isolates formed a distinct phylogenetic cluster within S. Typhimurium based on whole-genome-sequence polymorphisms. Comparative genome analysis of DT2 94-213 and S. Typhimurium SL1344, DT104, and D23580 identified few differences in gene content with the exception of variations within prophages. However, DT2 94-213 harbored 22 pseudogenes that were intact in other closely related S. Typhimurium strains. We report a novel in silico approach to identify single amino acid substitutions in proteins that have a high probability of a functional impact. One polymorphism identified using this method, a single-residue deletion in the Tar protein, abrogated chemotaxis to aspartate in vitro. DT2 94-213 also exhibited an altered transcriptional profile in response to culture at 42°C compared to that of SL1344. Such differentially regulated genes included a number involved in flagellum biosynthesis and motility. IMPORTANCE Whereas Salmonella enterica serovar Typhimurium can infect a wide range of animal species, some variants within this serovar exhibit a more limited host range and altered disease potential. Phylogenetic analysis based on whole-genome sequences can identify lineages associated with specific virulence traits, including host adaptation. This study represents one of the first to link pathogen-specific genetic signatures, including coding capacity, genome degradation, and transcriptional responses to host adaptation within a Salmonella serovar. We performed comparative genome analysis of reference and pigeon-adapted definitive type 2 (DT2) S. Typhimurium isolates alongside phenotypic and transcriptome analyses, to identify genetic signatures linked to host adaptation within the DT2 lineage.

Prevalence of Salmonella spp., and serovars isolated from captive exotic reptiles in New Zealand.

Science.gov (United States)

Kikillus, K H; Gartrell, B D; Motion, E

2011-07-01

To investigate the prevalence of Salmonella spp. in captive exotic reptile species in New Zealand, and identify the serovars isolated from this population. Cloacal swabs were obtained from 378 captive exotic reptiles, representing 24 species, residing in 25 collections throughout New Zealand between 2008 and 2009. Samples were cultured for Salmonella spp., and suspected colonies were serotyped by the Institute of Environmental Science and Research (ESR). Forty-three of the 378 (11.4%) reptiles sampled tested positive for Salmonella spp., with 95% CI for the estimated true prevalence being 12-25% in exotic reptiles in this study population. Lizards tested positive for Salmonella spp. more often than chelonians. Agamid lizards tested positive more often than any other family group, with 95% CI for the estimated true prevalence being 56-100%.. Six Salmonella serovars from subspecies I and two from subspecies II were isolated. The serovar most commonly isolated was S. Onderstepoort (30.2%), followed by S. Thompson (20.9%), S. Potsdam (14%), S. Wangata (14%), S. Infantis (11.6%) and S. Eastbourne (2.3%). All of the subspecies I serovars have been previously reported in both reptiles and humans in New Zealand, and include serovars previously associated with disease in humans. This study showed that Salmonella spp. were commonly carried by exotic reptiles in the study population in New Zealand. Several serovars of Salmonella spp. with known pathogenicity to humans were isolated, including S. Infantis, which is one of the most common serovars isolated from both humans and non-human sources in New Zealand. The limitations of this study included the bias engendered by the need for voluntary involvement in the study, and the non-random sampling design. Based on the serovars identified in this and previous studies, it is recommended native and exotic reptiles be segregated within collections, especially when native reptiles may be used for biodiversity restoration

SadA, a Trimeric Autotransporter from Salmonella enterica Serovar Typhimurium, Can Promote Biofilm Formation and Provides Limited Protection against Infection ▿ †

Science.gov (United States)

Raghunathan, Dhaarini; Wells, Timothy J.; Morris, Faye C.; Shaw, Robert K.; Bobat, Saeeda; Peters, Sarah E.; Paterson, Gavin K.; Jensen, Karina Tveen; Leyton, Denisse L.; Blair, Jessica M. A.; Browning, Douglas F.; Pravin, John; Flores-Langarica, Adriana; Hitchcock, Jessica R.; Moraes, Claudia T. P.; Piazza, Roxane M. F.; Maskell, Duncan J.; Webber, Mark A.; May, Robin C.; MacLennan, Calman A.; Piddock, Laura J.; Cunningham, Adam F.; Henderson, Ian R.

2011-01-01

Salmonella enterica is a major cause of morbidity worldwide and mortality in children and immunocompromised individuals in sub-Saharan Africa. Outer membrane proteins of Salmonella are of significance because they are at the interface between the pathogen and the host, they can contribute to adherence, colonization, and virulence, and they are frequently targets of antibody-mediated immunity. In this study, the properties of SadA, a purported trimeric autotransporter adhesin of Salmonella enterica serovar Typhimurium, were examined. We demonstrated that SadA is exposed on the Salmonella cell surface in vitro and in vivo during infection of mice. Expression of SadA resulted in cell aggregation, biofilm formation, and increased adhesion to human intestinal Caco-2 epithelial cells. Immunization of mice with folded, full-length, purified SadA elicited an IgG response which provided limited protection against bacterial challenge. When anti-SadA IgG titers were enhanced by administering alum-precipitated protein, a modest additional protection was afforded. Therefore, despite SadA having pleiotropic functions, it is not a dominant, protective antigen for antibody-mediated protection against Salmonella. PMID:21859856

Isolation and purification of enterocin E-760 with broad antimicrobial activity against gram-positive and gram-negative bacteria.

Science.gov (United States)

Line, J E; Svetoch, E A; Eruslanov, B V; Perelygin, V V; Mitsevich, E V; Mitsevich, I P; Levchuk, V P; Svetoch, O E; Seal, B S; Siragusa, G R; Stern, N J

2008-03-01

Strain NRRL B-30745, isolated from chicken ceca and identified as Enterococcus durans, Enterococcus faecium, or Enterococcus hirae, was initially identified as antagonistic to Campylobacter jejuni. The isolate produced a 5,362-Da bacteriocin (enterocin) that inhibits the growth of Salmonella enterica serovar Enteritidis, S. enterica serovar Choleraesuis, S. enterica serovar Typhimurium, S. enterica serovar Gallinarum, Escherichia coli O157:H7, Yersinia enterocolitica, Citrobacter freundii, Klebsiella pneumoniae, Shigella dysenteriae, Pseudomonas aeruginosa, Proteus mirabilis, Morganella morganii, Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Campylobacter jejuni, and 20 other Campylobacter species isolates. The enterocin, E-760, was isolated and purified by cation-exchange and hydrophobic-interaction chromatographies. The proteinaceous nature of purified enterocin E-760 was demonstrated upon treatment with various proteolytic enzymes. Specifically, the antimicrobial peptide was found to be sensitive to beta-chymotrypsin, proteinase K, and papain, while it was resistant to lysozyme and lipase. The enterocin demonstrated thermostability by retaining activity after 5 min at 100 degrees C and was stable at pH values between 5.0 and 8.7. However, activity was lost below pH 3.0 and above pH 9.5. Administration of enterocin E-760-treated feed significantly (P Enterocin E-760 also significantly (P < 0.05) reduced the colonization of naturally acquired Campylobacter species in market age broiler chickens when administered in treated feed 4 days prior to analysis.

Modification of Enrofloxacin Treatment Regimens for Poultry Experimentally Infected with Salmonella enterica Serovar Typhimurium DT104 To Minimize Selection of Resistance▿

Science.gov (United States)

Randall, Luke P.; Cooles, Sue W.; Coldham, Nick C.; Stapleton, Ken S.; Piddock, Laura J. V.; Woodward, Martin J.

2006-01-01

We hypothesized that higher doses of fluoroquinolones for a shorter duration could maintain efficacy (as measured by reduction in bacterial count) while reducing selection in chickens of bacteria with reduced susceptibility. Chicks were infected with Salmonella enterica serovar Typhimurium DT104 and treated 1 week later with enrofloxacin at the recommended dose for 5 days (water dose adjusted to give 10 mg/kg of body weight of birds or equivalence, i.e., water at 50 ppm) or at 2.5 or 5 times the recommended dose for 2 days or 1 day, respectively. The dose was delivered continuously (ppm) or pulsed in the water (mg/kg) or by gavage (mg/kg). In vitro in sera, increasing concentrations of 0.5 to 8 μg/ml enrofloxacin correlated with increased activity. In vivo, the efficacy of the 1-day treatment was significantly less than that of the 2- and 5-day treatments. The 2-day treatments showed efficacy similar to that of the 5-day treatment in all but one repeat treatment group and significantly (P < 0.01) reduced the Salmonella counts. Dosing at 2.5× the recommended dose and pulsed dosing both increased the peak antibiotic concentrations in cecal contents, liver, lung, and sera as determined by high-pressure liquid chromatography. There was limited evidence that shorter treatment regimens (in particular the 1-day regimen) selected for fewer strains with reduced susceptibility. In conclusion, the 2-day treatment would overall require a shorter withholding time than the 5-day treatment and, in view of the increased peak antibiotic concentrations, may give rise to improved efficacy, in particular for treating respiratory and systemic infections. However, it would be necessary to validate the 2-day regimen in a field situation and in particular against respiratory and systemic infections to validate or refute this hypothesis. PMID:17030564

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

Science.gov (United States)

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

2004-01-01

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

Salmonella enterica serovar Ohio septic arthritis and bone abscess in an immunocompetent patient: a case report

Directory of Open Access Journals (Sweden)

Kato Hideaki

2012-07-01

Full Text Available Abstract Introduction Non-typhi Salmonella species cause severe extra-intestinal focal infection after occult bacteremia. Although the number of cases of non-typhi salmonellosis is increasing worldwide among patients with immunocompromising conditions such as human immunodeficiency virus infection, infection is uncommon in immunocompetent subjects. We report a case of septic arthritis and bone abscess due to a rare non-typhi Salmonella organism that developed after a prolonged asymptomatic period. Case presentation A 44-year-old Japanese immunocompetent man presented with acute-onset left knee pain and swelling. He had no history of food poisoning, and his most recent travel to an endemic area was 19 years ago. Salmonella enterica serovar Ohio was identified from samples of bone abscess and joint tissue. Arthrotomy and necrotic tissue debridement followed by intravenous ceftriaxone was successful. Conclusions Non-typhi Salmonella species only rarely cause extra-intestinal focal infections in immunocompetent patients. Our case suggests that non-typhi Salmonella species can cause severe focal infections many years after the occult bacteremia associated with food poisoning.

Fifteen years of successful spread of Salmonella enterica serovar Mbandaka clone ST413 in Poland and its public health consequences

Directory of Open Access Journals (Sweden)

Andrzej Hoszowski

2016-06-01

Full Text Available In the 1990s, [i]Salmonella enterica[/i] serovar (S. Mbandaka occurred in feed and poultry in Poland. In the following years, the serovar also gained epidemiological importance in other EU countries. The objectives of current study were to evaluate the genetic relationship of contemporary S. Mbandaka with isolates originating from the beginning of the epidemics, and to assess the contribution of poultry as the source of infections in humans. Seventy S. Mbandaka isolated mainly in 2009 – 2010 from humans, poultry, food, and feed were typed with API ID32 [sup]®[/sup], MIC, plasmid profiling, PFGE, and MLST. PCR and sequencing were used to identify plasmid mediated quinolone and cephalosporin resistance mechanisms. Six biochemical profiles were identified and 59 of S. Mbandaka proved to be susceptible to the applied antimicrobials. Eight strains carried plasmids and a few of them were positive for [i]bla[/i][sub]CMY-2[/sub] and [i]qnr[/i]S1 genes. Two clusters of 15 [i]XbaI[/i]-PFGE profiles with similarity of 77.5% were found. The first cluster, gathered 7 profiles involving historical isolates and several contemporary non-human S. Mbandaka. The predominant profile in the second cluster consisted of 28 human and 1 broiler isolate. MLST analysis showed sequence type ST413 occurring among all tested isolates. The identification of close genetic relationships between S. Mbandaka of human and poultry origin indicates animals as a primal human infection route. Despite [i]Salmonella [/i]control programmes, the S. Mbandaka ST413 clone has been circulating for several years in Poland. [i]Salmonella[/i] control polices in food production chain should be continuously updated to target serovars of major epidemiological importance. Resistance noted in S. Mbandaka to such antimicrobials as fluoroquinolones and cephalosporins may hinder public health.

Polyamines are essential for virulence in Salmonella enterica serovar Gallinarum despite evolutionary decay of polyamine biosynthesis genes.

Science.gov (United States)

Schroll, Casper; Christensen, Jens P; Christensen, Henrik; Pors, Susanne E; Thorndahl, Lotte; Jensen, Peter R; Olsen, John E; Jelsbak, Lotte

2014-05-14

Serovars of Salmonella enterica exhibit different host-specificities where some have broad host-ranges and others, like S. Gallinarum and S. Typhi, are host-specific for poultry and humans, respectively. With the recent availability of whole genome sequences it has been reported that host-specificity coincides with accumulation of pseudogenes, indicating adaptation of host-restricted serovars to their narrow niches. Polyamines are small cationic amines and in Salmonella they can be synthesized through two alternative pathways directly from l-ornithine to putrescine and from l-arginine via agmatine to putrescine. The first pathway is not active in S. Gallinarum and S. Typhi, and this prompted us to investigate the importance of polyamines for virulence in S. Gallinarum. Bioinformatic analysis of all sequenced genomes of Salmonella revealed that pseudogene formation of the speC gene was exclusive for S. Typhi and S. Gallinarum and happened through independent events. The remaining polyamine biosynthesis pathway was found to be essential for oral infection with S. Gallinarum since single and double mutants in speB and speE, encoding the pathways from agmatine to putrescine and from putrescine to spermidine, were attenuated. In contrast, speB was dispensable after intraperitoneal challenge, suggesting that putrescine was less important for the systemic phase of the disease. In support of this hypothesis, a ΔspeE;ΔpotCD mutant, unable to synthesize and import spermidine, but with retained ability to import and synthesize putrescine, was attenuated after intraperitoneal infection. We therefore conclude that polyamines are essential for virulence of S. Gallinarum. Furthermore, our results point to distinct roles for putrescine and spermidine during systemic infection. Copyright © 2014 Elsevier B.V. All rights reserved.

Salmonella infections in Antarctic fauna and island populations of wildlife exposed to human activities in coastal areas of Australia.

Science.gov (United States)

Iveson, J B; Shellam, G R; Bradshaw, S D; Smith, D W; Mackenzie, J S; Mofflin, R G

2009-06-01

Salmonella infections in Antarctic wildlife were first reported in 1970 and in a search for evidence linking isolations with exposure to human activities, a comparison was made of serovars reported from marine fauna in the Antarctic region from 1982-2004 with those from marine mammals in the Northern hemisphere. This revealed that 10 (83%) Salmonella enterica serovars isolated from Antarctic penguins and seals were classifiable in high-frequency (HF) quotients for serovars prevalent in humans and domesticated animals. In Australia, 16 (90%) HF serovars were isolated from marine birds and mammals compared with 12 (86%) HF serovars reported from marine mammals in the Northern hemisphere. In Western Australia, HF serovars from marine species were also recorded in humans, livestock, mussels, effluents and island populations of wildlife in urban coastal areas. Low-frequency S. enterica serovars were rarely detected in humans and not detected in seagulls or marine species. The isolation of S. Enteritidis phage type 4 (PT4), PT8 and PT23 strains from Adélie penguins and a diversity of HF serovars reported from marine fauna in the Antarctic region and coastal areas of Australia, signal the possibility of transient serovars and endemic Salmonella strains recycling back to humans from southern latitudes in marine foodstuffs and feed ingredients.

Identification of Leptospira serovars by RFLP of the RNA polymerase beta subunit gene (rpoB

Directory of Open Access Journals (Sweden)

Lenice Roteia Cardoso Jung

2015-06-01

Full Text Available Leptospires are usually classified by methods based on DNA-DNA hybridization and the conventional cross-agglutination absorption test, which uses polyclonal antibodies against lipopolysaccharides. In this study, the amplification of the rpoB gene, which encodes the beta-subunit of RNA polymerase, was used as an alternative tool to identify Leptospira. DNA extracts from sixty-eight serovars were obtained, and the hypervariable region located between 1990 and 2500-bp in the rpoB gene was amplified by polymerase chain reaction (PCR. The 600-bp amplicons of the rpoB gene were digested with the restriction endonucleases TaqI, Tru1I, Sau3AI and MslI, and the restriction fragments were separated by 6% polyacrylamide gel electrophoresis. Thirty-five fragment patters were obtained from the combined data of restriction fragment length polymorphism (PCR-RFLP analysis and used to infer the phylogenetic relationships among the Leptospira species and serovars. The species assignments obtained were in full agreement with the established taxonomic classifications. Twenty-two serovars were effectively identified based on differences in their molecular profiles. However, the other 46 serovars remained clustered in groups that included more than one serovar of different species. This study demonstrates the value of RFLP analysis of PCR-amplified rpoB as an initial method for identifying Leptospira species and serovars.

Identification of Leptospira serovars by RFLP of the RNA polymerase beta subunit gene (rpoB).

Science.gov (United States)

Jung, Lenice Roteia Cardoso; Bomfim, Maria Rosa Quaresma; Kroon, Erna Geessien; Nunes, Álvaro Cantini

2015-06-01

Leptospires are usually classified by methods based on DNA-DNA hybridization and the conventional cross-agglutination absorption test, which uses polyclonal antibodies against lipopolysaccharides. In this study, the amplification of the rpoB gene, which encodes the beta-subunit of RNA polymerase, was used as an alternative tool to identify Leptospira. DNA extracts from sixty-eight serovars were obtained, and the hypervariable region located between 1990 and 2500-bp in the rpoB gene was amplified by polymerase chain reaction (PCR). The 600-bp amplicons of the rpoB gene were digested with the restriction endonucleases TaqI, Tru1I, Sau3AI and MslI, and the restriction fragments were separated by 6% polyacrylamide gel electrophoresis. Thirty-five fragment patters were obtained from the combined data of restriction fragment length polymorphism (PCR-RFLP) analysis and used to infer the phylogenetic relationships among the Leptospira species and serovars. The species assignments obtained were in full agreement with the established taxonomic classifications. Twenty-two serovars were effectively identified based on differences in their molecular profiles. However, the other 46 serovars remained clustered in groups that included more than one serovar of different species. This study demonstrates the value of RFLP analysis of PCR-amplified rpoB as an initial method for identifying Leptospira species and serovars.

Lymphogranuloma Venereum-Serovar L2b Presenting With Painful Genital Ulceration: An Emerging Clinical Presentation?

Science.gov (United States)

Haber, Roger; Maatouk, Ismaël; de Barbeyrac, Bertille; Bagot, Martine; Janier, Michel; Fouéré, Sébastien

2017-05-01

These 5 cases of atypical inflammatory lymphogranula venereum (LGV) serovar L2b presenting initially with edema and persistent painful ulceration illustrate that clinical manifestations of LGV in the current outbreak in men who have sex with men reflect the influence of both the serovars virulence and the host immune system and are not confined to proctitis. L2b serovar could have a particular high virulence profile, and the need for awareness of LGV as a cause of genital ulceration is crucial.

Complete genome sequence of a multiple drug resistant Salmonella enterica serovar Typhi CT18

DEFF Research Database (Denmark)

Parkhill, J.; Dougan, G.; James, K.D.

2001-01-01

Salmonella enterica serovar Typhi (S. typhi) is the aetiological agent of typhoid fever, a serious invasive bacterial disease of humans with an annual global burden of approximately 16 million cases, leading to 600,000 fatalities(1). Many S. enterica serovars actively invade the mucosal surface...

Prevalence and antimicrobial profiles of Salmonella serovars from ...

African Journals Online (AJOL)

ADEYEYE

2014-01-21

Jan 21, 2014 ... Presumptive Salmonella isolates were determined by using the conventional ... Salmonella represents a major contaminant of vegetables consumed in Maiduguri, North-eastern ... serovars in vegetables in Nigeria do not exist.

β-1,3/1,6-Glucan alleviated intestinal mucosal barrier impairment of broiler chickens challenged with Salmonella enterica serovar Typhimurium.

Science.gov (United States)

Shao, Yujing; Guo, Yuming; Wang, Zhong

2013-07-01

This study investigated the protective effect of β-1,3/1,6-glucan on gut morphology, intestinal epithelial tight junctions, and bacterial translocation of broiler chickens challenged with Salmonella enterica serovar Typhimurium. Ninety Salmonella-free Arbor Acre male broiler chickens were randomly divided into 3 groups: negative control group (NC), Salmonella Typhimurium-infected positive group (PC), and the Salmonella Typhimurium-infected group with dietary 100 mg/kg of β-1,3/1,6-glucan supplementation (T) to determine the effect of β-1,3/1,6-glucan on intestinal barrier function. Salmonella Typhimurium challenge alone significantly decreased villus height (P chickens challenged with Salmonella Typhimurium.

Draft Genome Sequence of Leptospira interrogans Serovar Bataviae Strain LepIMR 22 Isolated from a Rodent in Johor, Malaysia

NARCIS (Netherlands)

Amran, Fairuz; Mohd Khalid, Mohd Khairul Nizam; Mohamad, Saharuddin; Mat Ripen, Adiratna; Ahmad, Norazah; Goris, Marga G. A.; Muhammad, Ayu Haslin; Noor Halim, Nurul Atiqah

2016-01-01

Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia

Emergence of Ciprofloxacin-Resistant Salmonella enterica Serovar Typhi in Italy.

Directory of Open Access Journals (Sweden)

Aurora García-Fernández

Full Text Available In developed countries, typhoid fever is often associated with persons who travel to endemic areas or immigrate from them. Typhoid fever is a systemic infection caused by Salmonella enterica serovar Typhi. Because of the emergence of antimicrobial resistance to standard first-line drugs, fluoroquinolones are the drugs of choice. Resistance to ciprofloxacin by this Salmonella serovar represents an emerging public health issue. Two S. enterica ser. Typhi strains resistant to ciprofloxacin (CIP were reported to the Italian surveillance system for foodborne and waterborne diseases (EnterNet-Italia in 2013. The strains were isolated from two Italian tourists upon their arrival from India. A retrospective analysis of 17 other S. enterica ser. Typhi strains isolated in Italy during 2011-2013 was performed to determine their resistance to CIP. For this purpose, we assayed for susceptibility to antimicrobial agents and conducted PCR and nucleotide sequence analyses. Moreover, all strains were typed using pulsed-field gel electrophoresis to evaluate possible clonal relationships. Sixty-eight percent of the S. enterica ser. Typhi strains were resistant to CIP (MICs, 0.125-16 mg/L, and all isolates were negative for determinants of plasmid-mediated quinolone resistance. Analysis of sequences encoding DNA gyrase and topoisomerase IV subunits revealed mutations in gyrA, gyrB, and parC. Thirteen different clonal groups were detected, and the two CIP-resistant strains isolated from the individuals who visited India exhibited the same PFGE pattern. Because of these findings, the emergence of CIP-resistant S. enterica ser. Typhi isolates in Italy deserves attention, and monitoring antibiotic susceptibility is important for efficiently managing cases of typhoid fever.

Preliminary Investigations on the Distribution of Leptospira Serovars in Domestic Animals in North-west Morocco.

Science.gov (United States)

Benkirane, A; Noury, S; Hartskeerl, R A; Goris, M G A; Ahmed, A; Nally, J E

2016-04-01

Leptospirosis is a neglected zoonosis of global importance with a complex epidemiology that affects humans, domestic and wild mammals. However, due to the diversity of clinical signs and difficulties of establishing a confirmatory laboratory diagnosis, the disease remains poorly investigated, particularly in the developing world. In Morocco, a descriptive study of the seroprevalence of Leptospira infection in animals has never been undertaken. To fill this gap, the current study was conducted on a subset of animals in north-west Morocco as a preliminary step towards understanding the epidemiological patterns of animal leptospirosis in the country. The study was conducted on 289 serum samples collected between January and April 2012 from dogs, cattle, sheep, goats and donkeys in the areas of Rabat-Temara, Sidi Kacem and Oulmes. All serum samples were tested by the MAT with 14 reference strains of the most prevalent pathogenic serovars of Leptospira and two serovars of non-pathogenic Leptospira. The overall seroprevalence of Leptospira in cattle, sheep, goats, dogs and donkeys was 15%, 18%, 20%, 21% and 20%, respectively. The most prevalent serogroups found in each species were Ballum, Sejroe, and Australis in cattle, Ballum, Australis and Sejroe in sheep, Australis and Ballum in goats, Javanica and Australis in donkey and Australis, Ballum and Canicola in dogs. Of all the serogroups tested in this study, Icterohaemorrhagiae, the only serogroup which has been previously reported in humans in Morocco, was rarely reactive. The majority of reactive sera were collected from low land areas. A large number of sera samples classified as seronegative when tested against pathogenic leptospires were positive when tested against non-pathogenic leptospires; this is suggestive of possible novel, as yet unclassified, Leptospira serovars in Morocco. Eleven of thirteen sheep urine samples were positive by real-time PCR confirming their role as Leptospira carriers in Morocco. © 2014

Circulating serovars of Leptospira in cart horses of central and southern Ethiopia and associated risk factors.

Science.gov (United States)

Tsegay, K; Potts, A D; Aklilu, N; Lötter, C; Gummow, B

2016-03-01

Little work has been done on diseases of horses in Ethiopia or tropical regions of the world. Yet, Ethiopia has the largest horse population in Africa and their horses play a pivotal role in their economy as traction animals. A serological and questionnaire survey was therefore conducted to determine the circulating serovars of Leptospira and their association with potential risk factors in the cart horse population of Central and Southern Ethiopia. A total of 184 out of 418 cart horses from 13 districts had antibody titres of 1:100 or greater to at least one of 16 serovars of Leptospira species in Central and Southern Ethiopian horses. A significantly higher seropositivity (62.1%) was noted in horses from the highland agroecology followed by midland (44.4%) and lowland (39.8%). Serovar Bratislava (34.5%) was the predominant serovar followed by serovars Djasiman (9.8%), Topaz (5.98%) and Pomona (5.3%). Age and location proved to be associated with seropositive horses with older horses being more commonly affected and the districts of Ziway (Batu) (Apparent Prevalence (AP)=65.5%), Shashemene (AP=48.3%) and Sebeta (AP=41.4%) having the highest prevalence. Multivariable logistic regression found risk factors significantly associated with Leptospira seropositive horses were drinking river water (OR=2.8) and horses 7-12 years old (OR=5) and risk factors specifically associated with serovar Bratislava seropositive horses were drinking river water (OR=2.5), horses ≥13 years (OR=3.5) and the presence of dogs in adjacent neighbouring properties (OR=0.3). Dogs had a protective effect against seropositivity to serovars Bratislava and Djasiman, which may be due to their ability to control rodents. The high seroprevalence confirm that leptospirosis is endemic among horses of Central and Southern Ethiopia. The predominance of serovar Bratislava supports the idea that serovar Bratislava may be adapted to and maintained by the horse population of Central and Southern Ethiopia

Chlamydia trachomatis serovars of endemic trachoma had been ...

African Journals Online (AJOL)

Journal of Applied Sciences and Environmental Management ... The serovars that we identified from Japanese infants and pregnant women ... Once Japan was thought to be belong to an endemic area of trachoma as other Asian countries.

Cross neutralizing antibodies in hamsters vaccinated with leptospiral bacterins produced with three serovars of serogroup Sejroe

Directory of Open Access Journals (Sweden)

Rosana Tabata

2002-09-01

Full Text Available Three leptospiral bacterins, produced with different serovars of Serogroup Sejroe, namely the hardjo (bacterin A, wolffi (bacterin B and guaricura (bacterin C, were evaluated in male hamsters (Mesocricetus auratus by comparing the agglutinating and neutralizing antibodies titers using microscopic agglutination (MAT and in vitro growth inhibition (GIT tests. The immunization schedule was based on two 1.0 mL doses of non-diluted formalininactivated whole culture bacterin given through subcutaneous route with 10-day interval. The challenge was performed ten days after the second vaccine dose, when the animals were inoculated with 0.2 mL of non-inactivated cultures of each serovar through intraperitoneal route. On the 21st post-challenge day (PCD, all animals were bled and their sera were joined in pools (n=8 and tested by MAT and GIT. All vaccinated and control animals presented no clinical signs of leptospirosis after the challenge, but the serovar guaricura was isolated from the kidneys of control animals on the 21st PCD. The MAT results showed cross agglutinins between serovars hardjo and wolffi, and between wolffi and guaricura. The GIT results revealed the presence of cross neutralizing antibodies between serovars wolffi or guaricura against hardjo, wolffi and guaricura. It was found that the tested strain of serovar hardjo did not produce detectable levels of neutralizing antibodies, indicating its poor immunogenicity.

Draft Genome Sequence of Leptospira interrogans Serovar Bataviae Strain LepIMR 22 Isolated from a Rodent in Johor, Malaysia.

Science.gov (United States)

Amran, Fairuz; Mohd Khalid, Mohd Khairul Nizam; Mohamad, Saharuddin; Mat Ripen, Adiratna; Ahmad, Norazah; Goris, Marga G A; Muhammad, Ayu Haslin; Noor Halim, Nurul Atiqah

2016-09-08

Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia. Copyright © 2016 Amran et al.

Natural cross chlamydial infection between livestock and free-living bird species.

Directory of Open Access Journals (Sweden)

Jesús A Lemus

Full Text Available The study of cross-species pathogen transmission is essential to understanding the epizootiology and epidemiology of infectious diseases. Avian chlamydiosis is a zoonotic disease whose effects have been mainly investigated in humans, poultry and pet birds. It has been suggested that wild bird species play an important role as reservoirs for this disease. During a comparative health status survey in common (Falco tinnunculus and lesser (Falco naumanni kestrel populations in Spain, acute gammapathies were detected. We investigated whether gammapathies were associated with Chlamydiaceae infections. We recorded the prevalence of different Chlamydiaceae species in nestlings of both kestrel species in three different study areas. Chlamydophila psittaci serovar I (or Chlamydophila abortus, an ovine pathogen causing late-term abortions, was isolated from all the nestlings of both kestrel species in one of the three studied areas, a location with extensive ovine livestock enzootic of this atypical bacteria and where gammapathies were recorded. Serovar and genetic cluster analysis of the kestrel isolates from this area showed serovars A and C and the genetic cluster 1 and were different than those isolated from the other two areas. The serovar I in this area was also isolated from sheep abortions, sheep faeces, sheep stable dust, nest dust of both kestrel species, carrion beetles (Silphidae and Orthoptera. This fact was not observed in other areas. In addition, we found kestrels to be infected by Chlamydia suis and Chlamydia muridarum, the first time these have been detected in birds. Our study evidences a pathogen transmission from ruminants to birds, highlighting the importance of this potential and unexplored mechanism of infection in an ecological context. On the other hand, it is reported a pathogen transmission from livestock to wildlife, revealing new and scarcely investigated anthropogenic threats for wild and endangered species.

Identification of concomitant infection with Chlamydia trachomatis IncA-negative mutant and wild-type strains by genomic, transcriptional, and biological characterizations.

Science.gov (United States)

Suchland, Robert J; Jeffrey, Brendan M; Xia, Minsheng; Bhatia, Ajay; Chu, Hencelyn G; Rockey, Daniel D; Stamm, Walter E

2008-12-01

Clinical isolates of Chlamydia trachomatis that lack IncA on their inclusion membrane form nonfusogenic inclusions and have been associated with milder, subclinical infections in patients. The molecular events associated with the generation of IncA-negative strains and their roles in chlamydial sexually transmitted infections are not clear. We explored the biology of the IncA-negative strains by analyzing their genomic structure, transcription, and growth characteristics in vitro and in vivo in comparison with IncA-positive C. trachomatis strains. Three clinical samples were identified that contained a mixture of IncA-positive and -negative same-serovar C. trachomatis populations, and two more such pairs were found in serial isolates from persistently infected individuals. Genomic sequence analysis of individual strains from each of two serovar-matched pairs showed that these pairs were very similar genetically. In contrast, the genome sequence of an unmatched IncA-negative strain contained over 5,000 nucleotide polymorphisms relative to the genome sequence of a serovar-matched but otherwise unlinked strain. Transcriptional analysis, in vitro culture kinetics, and animal modeling demonstrated that IncA-negative strains isolated in the presence of a serovar-matched wild-type strain are phenotypically more similar to the wild-type strain than are IncA-negative strains isolated in the absence of a serovar-matched wild-type strain. These studies support a model suggesting that a change from an IncA-positive strain to the previously described IncA-negative phenotype may involve multiple steps, the first of which involves a translational inactivation of incA, associated with subsequent unidentified steps that lead to the observed decrease in transcript level, differences in growth rate, and differences in mouse infectivity.

PATHOGENIC LEPTOSPIRA SEROVARS IN FREE-LIVING SEA LIONS IN THE GULF OF CALIFORNIA AND ALONG THE BAJA CALIFORNIA COAST OF MEXICO.

Science.gov (United States)

Avalos-Téllez, Rosalía; Carrillo-Casas, Erika M; Atilano-López, Daniel; Godínez-Reyes, Carlos R; Díaz-Aparicio, Efrén; Ramírez-Delgado, David; Ramírez-Echenique, María F; Leyva-Leyva, Margarita; Suzán, Gerardo; Suárez-Güemes, Francisco

2016-04-28

The California sea lion ( Zalophus californianus ), a permanent inhabitant of the Gulf of California in Mexico, is susceptible to pathogenic Leptospira spp. infection, which can result in hepatic and renal damage and may lead to renal failure and death. During summer 2013, we used the microscopic agglutination test (MAT) to investigate the prevalence of anti-Leptospira antibodies in blood of clinically healthy sea lion pups from seven rookery islands on the Pacific Coast of Baja California (Pacific Ocean) and in the Gulf of California. We also used PCR to examine blood for Leptospira DNA. Isolation of Leptospira in liquid media was unsuccessful. We found higher antibody prevalence in sea lions from the rookery islands in the gulf than in those from the Pacific Coast. Antibodies against 11 serovars were identified in the Gulf of California population; the most frequent reactions were against serovars Bataviae (90%), Pyrogenes (86%), Wolffi (86%), Celledoni (71%), and Pomona (65%). In the Pacific Ocean population, MAT was positive against eight serovars, where Wolffi (88%), Pomona (75%), and Bataviae (70%) were the most frequent. Serum samples agglutinated with more than one Leptospira serovar. The maximum titer was 3,200. Each island had a different serology profile, and islands combined showed a distinct profile for each region. We detected pathogenic Leptospira DNA in 63% of blood samples, but we found no saprophytic Leptospira. Positive PCR results were obtained in blood samples with high and low MAT titers. Together, these two methods enhance the diagnosis and interpretation of sea lion leptospirosis. Our results may be related to human activities or the presence of other reservoirs with which sea lions interact, and they may also be related to sea lion stranding.

Changing trends in antimicrobial resistance of Salmonella enterica serovar typhi and salmonella enterica serovar paratyphi A in Chennai

Directory of Open Access Journals (Sweden)

Krishnan Padma

2009-10-01

Full Text Available Background and Objectives: Chloramphenicol was considered the anti-microbial gold standard for typhoid treatment but, following the increasing worldwide frequency of antibiotic resistance, ciprofloxacin has been the mainstay of therapy since 1980. Recent studies have shown a shifting of susceptibility to conventional drugs like chloramphenicol, ampicillin and cotrimoxazole. The primary objective of the study was to evaluate the in vitro activity of chloramphenicol and other first-line drugs in comparison with cephalosporins and quinolones. Materials and Methods: Fifty isolates of Salmonella obtained from blood culture were subjected to serotyping at the Central Research Institute, Kasauli. Phage typing and biotyping was performed at the National Phage Typing Centre, New Delhi. Antibiotic sensitivity testing was carried out for 10 drugs by the Kirby-Bauer disc diffusion method and minimum inhibitory concentration by broth microdilution for nalidixic acid, chloramphenicol, ciprofloxacin, ceftriaxone, cefixime and ofloxacin. Multi-drug-resistant (MDR strains were checked for plasmid. Results: In the present study, 70 and 30% of the isolates were Salmonella enterica serovar typhi and paratyphi A, respectively. They were highly sensitive to chloramphenicol (86%, ampicillin (84% and cotrimoxazole (88%. Highest sensitivity was seen for cephalosporins, followed by quinolones. Seventeen/21 (81% and 100% of the Salmonella enterica serovar typhi strains belonged to E1 phage type and biotype 1, respectively. Antibiogram showed 2% of the strains to be sensitive to all the drugs tested and 12% were MDR and showed the presence of plasmids. Conclusion: The study indicates reemergence of chloramphenicol-susceptible Salmonella enterica serovar typhi and paratyphi A isolates, a significant decline in MDR strains and high resistance to nalidixic acid. E1 phage type and biotype 1 are found to be most prevalent in Chennai, India.

Repeated isolation of Salmonella enterica Goverdhan, a very rare serovar, from Danish poultry surveillance samples

DEFF Research Database (Denmark)

Pedersen, Karl; Sørensen, Gitte; Szabo, Istvan

2014-01-01

We report here the appearance of a very rare serovar of Salmonella, S. enterica subsp. enterica serovar Goverdhan, in routine Salmonella surveillance samples from Danish poultry production. S. Goverdhan was found on nine occasions: in one broiler breeder farm in October 2010, four broiler farms a...

Receptor binding proteins of Listeria monocytogenes bacteriophages A118 and P35 recognize serovar-specific teichoic acids

Energy Technology Data Exchange (ETDEWEB)

Bielmann, Regula; Habann, Matthias; Eugster, Marcel R. [Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich (Switzerland); Lurz, Rudi [Max-Planck Institute for Molecular Genetics, 14195 Berlin (Germany); Calendar, Richard [Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202 (United States); Klumpp, Jochen, E-mail: jochen.klumpp@hest.ethz.ch [Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich (Switzerland); Loessner, Martin J. [Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092 Zurich (Switzerland)

2015-03-15

Adsorption of a bacteriophage to the host requires recognition of a cell wall-associated receptor by a receptor binding protein (RBP). This recognition is specific, and high affinity binding is essential for efficient virus attachment. The molecular details of phage adsorption to the Gram-positive cell are poorly understood. We present the first description of receptor binding proteins and a tail tip structure for the siphovirus group infecting Listeria monocytogenes. The host-range determining factors in two phages, A118 and P35 specific for L. monocytogenes serovar 1/2 have been determined. Two proteins were identified as RBPs in phage A118. Rhamnose residues in wall teichoic acids represent the binding ligands for both proteins. In phage P35, protein gp16 could be identified as RBP and the role of both rhamnose and N-acetylglucosamine in phage adsorption was confirmed. Immunogold-labeling and transmission electron microscopy allowed the creation of a topological model of the A118 phage tail. - Highlights: • We present the first description of receptor binding proteins and a tail tip structure for the Siphovirus group infecting Listeria monocytogenes. • The host-range determining factors in two phages, A118 and P35 specific for L. monocytogenes serovar 1/2 have been determined. • Rhamnose residues in wall teichoic acids represent the binding ligands for both receptor binding proteins in phage A118. • Rhamnose and N-acetylglucosamine are required for adsorption of phage P35. • We preset a topological model of the A118 phage tail.

Characterization of multidrug-resistant Salmonella enterica serovars Indiana and Enteritidis from chickens in Eastern China.

Directory of Open Access Journals (Sweden)

Yan Lu

Full Text Available A total of 310 Salmonella isolates were isolated from 6 broiler farms in Eastern China, serotyped according to the Kauffmann-White classification. All isolates were examined for susceptibility to 17 commonly used antimicrobial agents, representative isolates were examined for resistance genes and class I integrons using PCR technology. Clonality was determined by pulsed-field gel electrophoresis (PFGE. There were two serotypes detected in the 310 Salmonella strains, which included 133 Salmonella enterica serovar Indiana isolates and 177 Salmonella enterica serovar Enteritidis isolates. Antimicrobial sensitivity results showed that the isolates were generally resistant to sulfamethoxazole, ampicillin, tetracycline, doxycycline and trimethoprim, and 95% of the isolates sensitive to amikacin and polymyxin. Among all Salmonella enterica serovar Indiana isolates, 108 (81.2% possessed the blaTEM, floR, tetA, strA and aac (6'-Ib-cr resistance genes. The detected carriage rate of class 1 integrons was 66.5% (206/310, with 6 strains carrying gene integron cassette dfr17-aadA5. The increasing frequency of multidrug resistance rate in Salmonella was associated with increasing prevalence of int1 genes (rs = 0.938, P = 0.00039. The int1, blaTEM, floR, tetA, strA and aac (6'-Ib-cr positive Salmonella enterica serovar Indiana isolates showed five major patterns as determined by PFGE. Most isolates exhibited the common PFGE patterns found from the chicken farms, suggesting that many multidrug-resistant isolates of Salmonella enterica serovar Indiana prevailed in these sources. Some isolates with similar antimicrobial resistance patterns represented a variety of Salmonella enterica serovar Indiana genotypes, and were derived from a different clone.

Treatment failure in a typhoid patient infected with nalidixic acid resistant S. enterica serovar Typhi with reduced susceptibility to Ciprofloxacin: a case report from Cameroon

Directory of Open Access Journals (Sweden)

Asonganyi Etienne DN

2005-06-01

Full Text Available Abstract Background Fluoroquinolones or third generation cephalosporins are the drugs of choice for the treatment of typhoid fever. Treatment failure with fluoroquinolones has been reported in Asia and Europe. We report a case of ciprofloxacin treatment failure in typhoid fever in Cameroon. Case presentation A 29-year-old female patient with suspected typhoid fever from Kumba, Cameroon, yielded growth of Salmonella enterica serovar Typhi in blood culture. The isolate was resistant to nalidixic acid but sensitive to ciprofloxacin by disc diffusion test. However, the patient did not respond to treatment with ciprofloxacin, although the isolate was apparently susceptible to ciprofloxacin. Conclusion Treatment failure with ciprofloxacin in our case indicates the presence of nalidixic acid resistant S. enterica serovar Typhi (NARST with reduced susceptibility to ciprofloxacin in Cameroon (Central Africa.

Salmonella enterica Serovar Napoli Infection in Italy from 2000 to 2013: Spatial and Spatio-Temporal Analysis of Cases Distribution and the Effect of Human and Animal Density on the Risk of Infection.

Directory of Open Access Journals (Sweden)

Caterina Graziani

Full Text Available Salmonella Napoli is uncommon in Europe. In Italy however, it has been growing in importance since 2000. To date, no risk factors have been identified to account for its rise. This study aims at describing the epidemiology, spatial and spatio-temporal patterns of S. Napoli in Italy from 2000 to 2013, and to explore the role of several environmental correlates, namely urbanization, altitude and number of livestock farms, on the risk of S. Napoli infection among humans.Data were obtained from Enter-Net Italy, a network of diagnostic laboratories. The data were aggregated at the municipality level. Descriptive epidemiology, multivariate regression models, spatial and spatio-temporal analyses were performed on the number of cases and incidence rates.S. Napoli showed an expanding trend at the national level, and an increasing number of cases. Compared to the other main serovars in Italy, the risk of S. Napoli infection was higher in the age group <1 year, and lower in the other age groups. Although urbanization and the number of farms were associated with the risk of S. Napoli infection to some extent, their role in the epidemiology of the disease remains inconclusive. S. Napoli cases showed a positive global spatial autocorrelation as well as a significant spatio-temporal interaction. Twenty-four spatial and spatio-temporal clusters were identified, seven purely spatial and 17 spatio-temporal, mainly in north-western Italy. Most of the clusters were in areas characterized by urban and industrial settlements surrounded by agricultural land and an abundance of freshwater bodies.Our results point to the presence, in a number of areas in Italy, of a Salmonella of public health concern originating in the environment. This highlights the increasing relevance of environmental, non-food-related sources of human exposure to enteric pathogens.

Defining the Core Genome of Salmonella enterica Serovar Typhimurium for Genomic Surveillance and Epidemiological Typing

Science.gov (United States)

Fu, Songzhe; Octavia, Sophie; Tanaka, Mark M.; Sintchenko, Vitali

2015-01-01

Salmonella enterica serovar Typhimurium is the most common Salmonella serovar causing foodborne infections in Australia and many other countries. Twenty-one S. Typhimurium strains from Salmonella reference collection A (SARA) were analyzed using Illumina high-throughput genome sequencing. Single nucleotide polymorphisms (SNPs) in 21 SARA strains ranged from 46 to 11,916 SNPs, with an average of 1,577 SNPs per strain. Together with 47 strains selected from publicly available S. Typhimurium genomes, the S. Typhimurium core genes (STCG) were determined. The STCG consist of 3,846 genes, a set that is much larger than that of the 2,882 Salmonella core genes (SCG) found previously. The STCG together with 1,576 core intergenic regions (IGRs) were defined as the S. Typhimurium core genome. Using 93 S. Typhimurium genomes from 13 epidemiologically confirmed community outbreaks, we demonstrated that typing based on the S. Typhimurium core genome (STCG plus core IGRs) provides superior resolution and higher discriminatory power than that based on SCG for outbreak investigation and molecular epidemiology of S. Typhimurium. STCG and STCG plus core IGR typing achieved 100% separation of all outbreaks compared to that of SCG typing, which failed to separate isolates from two outbreaks from background isolates. Defining the S. Typhimurium core genome allows standardization of genes/regions to be used for high-resolution epidemiological typing and genomic surveillance of S. Typhimurium. PMID:26019201

Antimicrobial resistance in Salmonella enterica subsp. enterica serovar typhimurium from humans and production animals

DEFF Research Database (Denmark)

Seyfarth, Anne Mette; Wegener, Henrik Caspar; FrimodtMoller, N.

1997-01-01

: Poultry strains were usually resistant only to ampicillin, white pig and cattle isolates were most often resistant to sulphonamide, tetracycline and streptomycin. Typing of the strains showed that some animal strains and human strains were indistinguishable. In conclusion, while antimicrobial resistance......We have studied the frequency of antimicrobial resistance and epidemiological relatedness among 473 isolates of Salmonella enterica subsp, enterica serovar typhimurium (S. typhimurium) from human and veterinary sources. The human strains were clinical isolates from patients with diarrhoea sent...... to the State Serum Institute during August 1993 (228 isolates). The animal strains were isolated from clinical or subclinical infections in cattle (48 isolates), pigs (99 isolates) or poultry (98 isolates), all from 1993. All strains were tested against 22 different antimicrobial agents used in both human...

Salmonella enterica serovar typhimurium exploits inflammation to compete with the intestinal microbiota.

Directory of Open Access Journals (Sweden)

Bärbel Stecher

2007-10-01

Full Text Available Most mucosal surfaces of the mammalian body are colonized by microbial communities ("microbiota". A high density of commensal microbiota inhabits the intestine and shields from infection ("colonization resistance". The virulence strategies allowing enteropathogenic bacteria to successfully compete with the microbiota and overcome colonization resistance are poorly understood. Here, we investigated manipulation of the intestinal microbiota by the enteropathogenic bacterium Salmonella enterica subspecies 1 serovar Typhimurium (S. Tm in a mouse colitis model: we found that inflammatory host responses induced by S. Tm changed microbiota composition and suppressed its growth. In contrast to wild-type S. Tm, an avirulent invGsseD mutant failing to trigger colitis was outcompeted by the microbiota. This competitive defect was reverted if inflammation was provided concomitantly by mixed infection with wild-type S. Tm or in mice (IL10(-/-, VILLIN-HA(CL4-CD8 with inflammatory bowel disease. Thus, inflammation is necessary and sufficient for overcoming colonization resistance. This reveals a new concept in infectious disease: in contrast to current thinking, inflammation is not always detrimental for the pathogen. Triggering the host's immune defence can shift the balance between the protective microbiota and the pathogen in favour of the pathogen.

Variable carbon catabolism among Salmonella enterica serovar Typhi isolates.

Directory of Open Access Journals (Sweden)

Lay Ching Chai

Full Text Available BACKGROUND: Salmonella enterica serovar Typhi (S. Typhi is strictly a human intracellular pathogen. It causes acute systemic (typhoid fever and chronic infections that result in long-term asymptomatic human carriage. S. Typhi displays diverse disease manifestations in human infection and exhibits high clonality. The principal factors underlying the unique lifestyle of S. Typhi in its human host during acute and chronic infections remain largely unknown and are therefore the main objective of this study. METHODOLOGY/PRINCIPAL FINDINGS: To obtain insight into the intracellular lifestyle of S. Typhi, a high-throughput phenotypic microarray was employed to characterise the catabolic capacity of 190 carbon sources in S. Typhi strains. The success of this study lies in the carefully selected library of S. Typhi strains, including strains from two geographically distinct areas of typhoid endemicity, an asymptomatic human carrier, clinical stools and blood samples and sewage-contaminated rivers. An extremely low carbon catabolic capacity (27% of 190 carbon substrates was observed among the strains. The carbon catabolic profiles appeared to suggest that S. Typhi strains survived well on carbon subtrates that are found abundantly in the human body but not in others. The strains could not utilise plant-associated carbon substrates. In addition, α-glycerolphosphate, glycerol, L-serine, pyruvate and lactate served as better carbon sources to monosaccharides in the S. Typhi strains tested. CONCLUSION: The carbon catabolic profiles suggest that S. Typhi could survive and persist well in the nutrient depleted metabolic niches in the human host but not in the environment outside of the host. These findings serve as caveats for future studies to understand how carbon catabolism relates to the pathogenesis and transmission of this pathogen.

rpoS-Regulated core genes involved in the competitive fitness of Salmonella enterica Serovar Kentucky in the intestines of chickens.

Science.gov (United States)

Cheng, Ying; Pedroso, Adriana Ayres; Porwollik, Steffen; McClelland, Michael; Lee, Margie D; Kwan, Tiffany; Zamperini, Katherine; Soni, Vivek; Sellers, Holly S; Russell, Scott M; Maurer, John J

2015-01-01

Salmonella enterica serovar Kentucky has become the most frequently isolated serovar from poultry in the United States over the past decade. Despite its prevalence in poultry, it causes few human illnesses in the United States. The dominance of S. Kentucky in poultry does not appear to be due to single introduction of a clonal strain, and its reduced virulence appears to correlate with the absence of virulence genes grvA, sseI, sopE, and sodC1. S. Kentucky's prevalence in poultry is possibly attributable to its metabolic adaptation to the chicken cecum. While there were no difference in the growth rate of S. Kentucky and S. Typhimurium grown microaerophilically in cecal contents, S. Kentucky persisted longer when chickens were coinfected with S. Typhimurium. The in vivo advantage that S. Kentucky has over S. Typhimurium appears to be due to differential regulation of core Salmonella genes via the stationary-phase sigma factor rpoS. Microarray analysis of Salmonella grown in cecal contents in vitro identified several metabolic genes and motility and adherence genes that are differentially activated in S. Kentucky. The contributions of four of these operons (mgl, prp, nar, and csg) to Salmonella colonization in chickens were assessed. Deletion of mgl and csg reduced S. Kentucky persistence in competition studies in chickens infected with wild-type or mutant strains. Subtle mutations affecting differential regulation of core Salmonella genes appear to be important in Salmonella's adaptation to its animal host and especially for S. Kentucky's emergence as the dominant serovar in poultry. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts.

Science.gov (United States)

Mgode, Georgies F; Machang'u, Robert S; Mhamphi, Ginethon G; Katakweba, Abdul; Mulungu, Loth S; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A; Belmain, Steven R

2015-12-01

The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries.

Genomic characterisation of invasive non-typhoidal Salmonella enterica Subspecies enterica Serovar Bovismorbificans isolates from Malawi.

Directory of Open Access Journals (Sweden)

Christina Bronowski

2013-11-01

Full Text Available Invasive Non-typhoidal Salmonella (iNTS are an important cause of bacteraemia in children and HIV-infected adults in sub-Saharan Africa. Previous research has shown that iNTS strains exhibit a pattern of gene loss that resembles that of host adapted serovars such as Salmonella Typhi and Paratyphi A. Salmonella enterica serovar Bovismorbificans was a common serovar in Malawi between 1997 and 2004.We sequenced the genomes of 14 Malawian bacteraemia and four veterinary isolates from the UK, to identify genomic variations and signs of host adaptation in the Malawian strains.Whole genome phylogeny of invasive and veterinary S. Bovismorbificans isolates showed that the isolates are highly related, belonging to the most common international S. Bovismorbificans Sequence Type, ST142, in contrast to the findings for S. Typhimurium, where a distinct Sequence Type, ST313, is associated with invasive disease in sub-Saharan Africa. Although genome degradation through pseudogene formation was observed in ST142 isolates, there were no clear overlaps with the patterns of gene loss seen in iNTS ST313 isolates previously described from Malawi, and no clear distinction between S. Bovismorbificans isolates from Malawi and the UK. The only defining differences between S. Bovismorbificans bacteraemia and veterinary isolates were prophage-related regions and the carriage of a S. Bovismorbificans virulence plasmid (pVIRBov.iNTS S. Bovismorbificans isolates, unlike iNTS S. Typhiumrium isolates, are only distinguished from those circulating elsewhere by differences in the mobile genome. It is likely that these strains have entered a susceptible population and are able to take advantage of this niche. There are tentative signs of convergent evolution to a more human adapted iNTS variant. Considering its importance in causing disease in this region, S. Bovismorbificans may be at the beginning of this process, providing a reference against which to compare changes that may

Molecular Characterization of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Typhimurium Isolates from Swine

OpenAIRE

Gebreyes, Wondwossen Abebe; Altier, Craig

2002-01-01

As part of a longitudinal study of antimicrobial resistance among salmonellae isolated from swine, we studied 484 Salmonella enterica subsp. enterica serovar Typhimurium (including serovar Typhimurium var. Copenhagen) isolates. We found two common pentaresistant phenotypes. The first was resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (the AmCmStSuTe phenotype; 36.2% of all isolates), mainly of the definitive type 104 (DT104) phage type (180 of 187 ...

Acute seronegative polyarthritis associated with lymphogranuloma venereum infection in a patient with prevalent HIV infection.

Science.gov (United States)

Kober, C; Richardson, D; Bell, C; Walker-Bone, K

2011-01-01

A 44-year-old man who has sex with men presented with a three-month asymmetrical polyarthropathy. He had a positive HIV-1 antibody test consistent with infection acquired more than six months previously. Lymphogranuloma venereum (LGV)-associated DNA was detected from a rectal swab. Following successful treatment for LGV his arthritis resolved completely. Infection with HIV-1 has been hypothesized to cause reactive arthritis but this has been disputed. The most likely diagnosis in this patient was sexually acquired reactive arthritis secondary to LGV infection. As LGV can be asymptomatic and treatment differs from that of the other serovars, screening should be considered in all men who have sex with men (MSM) presenting with acute arthritis, particularly if they are HIV infected.

SALMONELLA ENTERICA SUBSPECIES ENTERICA SEROVAR ENTERITIDIS – ACTUALITIES AND IMPORTANCE

Directory of Open Access Journals (Sweden)

Predrag Stojanović

2010-09-01

Full Text Available Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis has been recently recognized as a prevalent cause of alimentary toxi-infection worldwide. Its widespread presence could be explained by intensification and globalization of traffic, global trade, and the rest of socioeconomic processes. However, no matter to global spreading of S. Enteritidis, there is unequal distribution of certain phage types (PT where PT 4 and 8 are predominant. Salmonella is considered as a cause of various diseases from acute enterocolitis to typhoid fever. All bacteria from this species have numerous virulence factors such as: adhesins, toxins, virulence plasmids, and cell wall lipopolysaccharides (LPS. Similar to other salmonella serotypes, S. Enteritidis has a virulence plasmid. It allows a bacterium to persist inside the reticuloendothelial cells, while strains without it are eliminated quickly. In the last few years several virulent S. Enteritidis strains of PT 4 were described and considered to be of the same origin. The domination of PT 4 is probably subjected to the resistance of certain strains to nitrofurantoin which is used in poultry rising. The increased significance of S. Enteritidis refers not only to its association with pandemic problems but to frequent reports about extraintestinal infectious processes caused by this bacterium. Taking into consideration that eggs are very important source of infection besides poultry meat, the advised efficient preventive measures, among others, should be some changes in poultry meat preparation, investigation of outbreak-related flocks and devastation of infected ones, as well as egg pasteurization.

A Phylogenetic and Phenotypic Analysis of Salmonella enterica Serovar Weltevreden, an Emerging Agent of Diarrheal Disease in Tropical Regions.

Directory of Open Access Journals (Sweden)

Carine Makendi

2016-02-01

Full Text Available Salmonella enterica serovar Weltevreden (S. Weltevreden is an emerging cause of diarrheal and invasive disease in humans residing in tropical regions. Despite the regional and international emergence of this Salmonella serovar, relatively little is known about its genetic diversity, genomics or virulence potential in model systems. Here we used whole genome sequencing and bioinformatics analyses to define the phylogenetic structure of a diverse global selection of S. Weltevreden. Phylogenetic analysis of more than 100 isolates demonstrated that the population of S. Weltevreden can be segregated into two main phylogenetic clusters, one associated predominantly with continental Southeast Asia and the other more internationally dispersed. Subcluster analysis suggested the local evolution of S. Weltevreden within specific geographical regions. Four of the isolates were sequenced using long read sequencing to produce high quality reference genomes. Phenotypic analysis in Hep-2 cells and in a murine infection model indicated that S. Weltevreden were significantly attenuated in these models compared to the classical S. Typhimurium reference strain SL1344. Our work outlines novel insights into this important emerging pathogen and provides a baseline understanding for future research studies.

Isolation of Leptospira santarosai, serovar guaricura from buffaloes (Bubalus bubalis in Vale do Ribeira, São Paulo, Brazil

Directory of Open Access Journals (Sweden)

Vasconcellos Silvio A.

2001-01-01

Full Text Available In April 1998 urine samples from adult female buffaloes were collected in a farm located in Registro, Vale do Ribeira, São Paulo State, Brazil. The urine samples obtained after furosemide injection were immediately transported to the laboratory in liquid modified EMJH medium and seeded, by the serial dilution technique, into Fletcher's or modified EMJH-0.2% agar, both of them with 5-fluorouracil 100mg/mL. The intraperitoneoum inoculation of 0.5 mL was also performed with each urine sample in young, adult hamsters (Mesocricetus auratus. All samples seeded directly in culture medium were contaminated. The hamsters did not show any sign of disease and were killed at the 21st post inoculation day. At this time kidney cultures of these animals were performed and from one of them, one leptospira strain (M04-98 was isolated, identified as belonging to serogroup Sejroe by Microscopic Agglutination Test (MAT with a panel of 36 rabbit sera against serovars representative for the pathogenic serogroups. Subsequently, MAT was carried out with antisera against the 19 reference strains of serogroup Sejroe, revealing a close relationship with serovar guaricura. Afterwards the MAT was done with a panel of 18 monoclonal antibodies representative for serovars of serogroup Sejroe. The histogram closely resembled that of serovar guaricura. So Cross Agglutination Absorption Test (CAAT was carried out with the buffalo isolate and serovar guaricura, supporting the relationship between the buffalo isolate and serovar guaricura.

Rapid Determination of Lymphogranuloma Venereum Serovars of Chlamydia trachomatis by Quantitative High-Resolution Melt Analysis (HRMA)

Science.gov (United States)

Stevens, Matthew P.; Garland, Suzanne M.; Zaia, Angelo M.; Tabrizi, Sepehr N.

2012-01-01

A quantitative high-resolution melt analysis assay was developed to differentiate lymphogranuloma venereum-causing serovars of Chlamydia trachomatis (L1 to L3) from other C. trachomatis serovars (D to K). The detection limit of this assay is approximately 10 copies per reaction, comparable to the limits of other quantitative-PCR-based methods. PMID:22933594

Molecular Characterisation of Salmonella enterica Serovar Typhi Isolated from Typhoidial Humans

Directory of Open Access Journals (Sweden)

Arunava Das

2012-09-01

Full Text Available Aims: Salmonella enterica serovar Typhi is the major causative agent for typhoidial fever around the globe among human population reported till date. Present research work was carried out for detection and molecular characterisation of Salmonella enterica serovar Typhi isolated from humans with Typhoidial fever by biochemical, phenotypical and virulence gene based polymerase chain reaction (PCR techniques. The isolated strains were also investigated for antibiotic susceptibility patterns as a control measure. Methodology and Results: A total of 16 clinical samples were collected from the same numbers of patients (7 males and 9 females from Coimbatore, Erode and Salem districts of Tamil Nadu and were processed via broth enrichment methods for isolation and identification of the causative agent S. enterica serovar Typhi. Microbiological and biochemical investigations revealed the presence of S. Typhi from 16 samples. The biotyping of the isolates showed that all the isolates belonged to biotype IV. The PCR analysis confirmed the presence of invA (Invasion gene, 244bp, tyv (Tyveloseepimerase gene, 615 bp, fliC-d (Phage-1 flagellin gene for d-antigen, 750 bp and viaB (Vi antigen gene, 439bp in all 16 clinical samples. The antibiotic susceptibility test that was carried out among the isolates against 12 antimicrobial agents, showed 100 % resistance to only ampicillin and 100 % sensitivity to carbenicillin, chloramphenicol, clindamycin, gentamycin, kanamycin and tetracycline.Conclusion, significance and impact of study: This study confirmed the association of virulent strains of S. enterica serovar Typhi from Typhoidial fever among human population and suggested that PCR based diagnostic could be very useful for the rapid detection of S. Typhi isolates. Present study emphasized the use of antibiotic like chloramphenicol or in combination with other antibiotics for the effective control of S. Typhi.

Chlamydia trachomatis Serovar Distribution and Neisseria gonorrhoeae Coinfection in Male Patients with Urethritis in Greece▿

Science.gov (United States)

Papadogeorgakis, Helen; Pittaras, Theodore E.; Papaparaskevas, Joseph; Pitiriga, Vassiliki; Katsambas, Andreas; Tsakris, Athanassios

2010-01-01

The distribution of Chlamydia trachomatis serovars and Neisseria gonorrhoeae coinfection was studied in a group of 100 C. trachomatis-positive males with urethritis in Greece. The serovar distribution revealed that apart from the predominant worldwide types E and F, the relatively uncommon type G is also prevalent. Gonococcal coinfection was frequent (30%) and was associated with genovariant Ja (75%, P = 0.008). PMID:20357220

Vaccination with leptospiral outer membrane lipoprotein LipL32 reduces kidney invasion of Leptospira interrogans serovar canicola in hamsters.

Science.gov (United States)

Humphryes, P C; Weeks, M E; AbuOun, M; Thomson, G; Núñez, A; Coldham, N G

2014-04-01

The Leptospira interrogans vaccines currently available are serovar specific and require regular booster immunizations to maintain protection of the host. In addition, a hamster challenge batch potency test is necessary to evaluate these vaccines prior to market release, requiring the use of a large number of animals, which is ethically and financially undesirable. Our previous work showed that the N terminus of the outer membrane protein LipL32 was altered in Leptospira interrogans serovar Canicola vaccines that fail the hamster challenge test, suggesting that it may be involved in the protective immune response. The aim of this study was to determine if vaccination with LipL32 protein alone could provide a protective response against challenge with L. interrogans serovar Canicola to hamsters. Recombinant LipL32, purified from an Escherichia coli expression system, was assessed for protective immunity in five groups of hamsters (n = 5) following a challenge with the virulent L. interrogans serovar Canicola strain Kito as a challenge strain. However, no significant survival against the L. interrogans serovar Canicola challenge was observed compared to that of unvaccinated negative controls. Subsequent histological analysis revealed reduced amounts of L. interrogans in the kidneys from the hamsters vaccinated with recombinant LipL32 protein prior to challenge; however, no significant survival against the L. interrogans serovar Canicola challenge was observed compared to that of unvaccinated negative controls. This finding corresponded to a noticeably reduced severity of renal lesions. This study provides evidence that LipL32 is involved in the protective response against L. interrogans serovar Canicola in hamsters and is the first reported link to LipL32-induced protection against kidney invasion.

Challenge of Humans with Wild-type Salmonella enterica Serovar Typhi Elicits Changes in the Activation and Homing Characteristics of Mucosal-Associated Invariant T Cells

OpenAIRE

Salerno-Goncalves, Ros?ngela; Luo, David; Fresnay, Stephanie; Magder, Laurence; Darton, Thomas C.; Jones, Claire; Waddington, Claire S.; Blohmke, Christoph J.; Angus, Brian; Levine, Myron M.; Pollard, Andrew J.; Sztein, Marcelo B.

2017-01-01

Gastrointestinal infections by Salmonella enterica serovar Typhi (S. Typhi) are rare in industrialized countries. However, they remain a major public health problem in the developing world with an estimated 26.9 million new cases annually and significant mortality when untreated. Recently, we provided the first direct evidence that CD8(+) MAIT cells are activated and have the potential to kill cells exposed to S. Typhi, and that these responses are dependent on bacterial load. However, MAIT c...

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

Science.gov (United States)

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

2014-10-01

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

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

Science.gov (United States)

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

2016-01-01

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

Listeria prevalence and Listeria monocytogenes serovar diversity at cull cow and bull processing plants in the United States.

Science.gov (United States)

Guerini, Michael N; Brichta-Harhay, Dayna M; Shackelford, T Steven D; Arthur, Terrance M; Bosilevac, Joseph M; Kalchayanand, Norasak; Wheeler, Tommy L; Koohmaraie, Mohammad

2007-11-01

Listeria monocytogenes, the causative agent of epidemic and sporadic listeriosis, is routinely isolated from many sources, including cattle, yet information on the prevalence of Listeria in beef processing plants in the United States is minimal. From July 2005 through April 2006, four commercial cow and bull processing plants were sampled in the United States to determine the prevalence of Listeria and the serovar diversity of L. monocytogenes. Samples were collected during the summer, fall, winter, and spring. Listeria prevalence on hides was consistently higher during cooler weather (28 to 92% of samples) than during warmer weather (6 and 77% of samples). The Listeria prevalence data collected from preevisceration carcass ranged from undetectable in some warm season samples to as high as 71% during cooler weather. Listeria on postintervention carcasses in the chill cooler was normally undetectable, with the exception of summer and spring samples from one plant where > 19% of the carcasses were positive for Listeria. On hides, L. monocytogenes serovar 1/2a was the predominant serovar observed, with serovars 1/2b and 4b present 2.5 times less often and serovar 1/2c not detected on any hides sampled. L. monocytogenes serovars 1/2a, 1/2c, and 4b were found on postintervention carcasses. This prevalence study demonstrates that Listeria species are more prevalent on hides during the winter and spring and that interventions being used in cow and bull processing plants appear to be effective in reducing or eliminating Listeria contamination on carcasses.

Damage/Danger Associated Molecular Patterns (DAMPs Modulate Chlamydia pecorum and C. trachomatis Serovar E Inclusion Development In Vitro.

Directory of Open Access Journals (Sweden)

Cory Ann Leonard

Full Text Available Persistence, more recently termed the chlamydial stress response, is a viable but non-infectious state constituting a divergence from the characteristic chlamydial biphasic developmental cycle. Damage/danger associated molecular patterns (DAMPs are normal intracellular components or metabolites that, when released from cells, signal cellular damage/lysis. Purine metabolite DAMPs, including extracellular ATP and adenosine, inhibit chlamydial development in a species-specific manner. Viral co-infection has been shown to reversibly abrogate Chlamydia inclusion development, suggesting persistence/chlamydial stress. Because viral infection can cause host cell DAMP release, we hypothesized DAMPs may influence chlamydial development. Therefore, we examined the effect of extracellular ATP, adenosine, and cyclic AMP exposure, at 0 and 14 hours post infection, on C. pecorum and C. trachomatis serovar E development. In the absence of de novo host protein synthesis, exposure to DAMPs immediately post or at 14 hours post infection reduced inclusion size; however, the effect was less robust upon 14 hours post infection exposure. Additionally, upon exposure to DAMPs immediately post infection, bacteria per inclusion and subsequent infectivity were reduced in both Chlamydia species. These effects were reversible, and C. pecorum exhibited more pronounced recovery from DAMP exposure. Aberrant bodies, typical in virus-induced chlamydial persistence, were absent upon DAMP exposure. In the presence of de novo host protein synthesis, exposure to DAMPs immediately post infection reduced inclusion size, but only variably modulated chlamydial infectivity. Because chlamydial infection and other infections may increase local DAMP concentrations, DAMPs may influence Chlamydia infection in vivo, particularly in the context of poly-microbial infections.

Plasmid fingerprinting and virulence gene detection among indigenous strains of salmonella enterica serovar enteritidis

International Nuclear Information System (INIS)

Sajid, S.U.; Schwarz, S.

2009-01-01

Salmonella enterica serovar Enteritidis is an important frequently reported zoonotic pathogen and a common cause of human gastroenteritis worldwide. The highly conserved Serospecific plasmids (SSPs) and Salmonella plasmid virulence (Spv) genes have been shown to mediate extra-intestinal colonization and systemic infection. The objective of current study was to document the presence of SSPs and SpvB/SpvC genes prevailing in the indigenous population of serovar Enteritidis. A total of 48 epidemiologically unrelated strains of Salmonella enteritidis were included in the study. Preparation of plasmids DNA suitable for endonuclease digestion and separation of respective fragments by agarose gel electrophoresis followed previously described protocols. The plasmids of Escherichia coli V517, 1-kbp ladder, and lambda DNA HindIII fragments served as DNA size standards. Transfer of DNA fragments from agarose gels to nitrocellulose membranes was achieved by capillary blot procedure. An ECL labeled 3.6 kbp HindIII fragment of plasmid PRQ 51 was used as probe for SpvB/SpvC gene detection. Plasmid DNA fingerprinting revealed the presence of two different profiles of approximately 55 kbp and 90 kbp and were identified as virulence plasmids by DNA hybridization. The SpvB/SpvC genes were located on HindIII fragments of 3.6 kbp in each of the two types of virulence plasmids. The study confirms the presence of SSPs and SpvB/SpvC genes in indigenous strains of S. enteritidis isolated from Northern Punjab area of Pakistan and substantiate the previous data on such findings from other parts of the world. (author)

Repeated maternal intramuscular or intraamniotic erythromycin incompletely resolves intrauterine Ureaplasma parvum infection in a sheep model of pregnancy.

Science.gov (United States)

Kemp, Matthew W; Miura, Yuichiro; Payne, Matthew S; Watts, Rory; Megharaj, Smruthi; Jobe, Alan H; Kallapur, Suhas G; Saito, Masatoshi; Spiller, O Brad; Keelan, Jeffrey A; Newnham, John P

2014-08-01

Ureaplasma spp are the most commonly isolated microorganisms in association with preterm birth. Maternal erythromycin administration is a standard treatment for preterm prelabor rupture of membranes. There is little evidence of its effectiveness in eradicating Ureaplasma spp from the intrauterine cavity and fetus. We used a sheep model of intrauterine Ureaplasma spp infection to investigate the efficacy of repeated maternal intramuscular and intraamniotic erythromycin treatment to eradicate such an infection. Thirty ewes with singleton pregnancies received an intraamniotic injection of 10(7) color change units of erythromycin-sensitive Ureaplasma parvum serovar 3 at 55 days' gestation. At 116 days' gestation, 28 ewes with viable fetuses were randomized to receive (1) intraamniotic and maternal intramuscular saline solution treatment (n = 8), (2) single intraamniotic and repeated maternal intramuscular erythromycin treatment (n = 10), or (3) single maternal intramuscular and repeated intraamniotic erythromycin treatment (n = 10). Fetuses were surgically delivered at 125 days' gestation. Treatment efficacy was assessed by culture, quantitative polymerase chain reaction, and histopathologic evaluation. Animals treated with intraamniotic erythromycin had significantly less viable U parvum serovar 3 in the amniotic fluid at delivery. However, neither combination of maternal intramuscular and intraamniotic erythromycin treatment successfully cleared U parvum serovar 3 from the amniotic fluid or fetal tissues. Three de novo erythromycin-resistant U parvum isolates were identified in erythromycin-treated animals. Erythromycin treatment, given both to the ewe and into the amniotic cavity, fails to eradicate intrauterine and fetal U parvum serovar 3 infection and may lead to development of erythromycin resistant U parvum. Copyright © 2014 Mosby, Inc. All rights reserved.

Molecular typing of Salmonella enterica serovar typhi isolates from various countries in Asia by a multiplex PCR assay on variable-number tandem repeats.

Science.gov (United States)

Liu, Yichun; Lee, May-Ann; Ooi, Eng-Eong; Mavis, Yeo; Tan, Ai-Ling; Quek, Hung-Hiang

2003-09-01

A multiplex PCR method incorporating primers flanking three variable-number tandem repeat (VNTR) loci (arbitrarily labeled TR1, TR2, and TR3) in the CT18 strain of Salmonella enterica serovar Typhi has been developed for molecular typing of S. enterica serovar Typhi clinical isolates from several Asian countries, including Singapore, Indonesia, India, Bangladesh, Malaysia, and Nepal. We have demonstrated that the multiplex PCR could be performed on crude cell lysates and that the VNTR banding profiles produced could be easily analyzed by visual inspection after conventional agarose gel electrophoresis. The assay was highly discriminative in identifying 49 distinct VNTR profiles among 59 individual isolates. A high level of VNTR profile heterogeneity was observed in isolates from within the same country and among countries. These VNTR profiles remained stable after the strains were passaged extensively under routine laboratory culture conditions. In contrast to the S. enterica serovar Typhi isolates, an absence of TR3 amplicons and a lack of length polymorphisms in TR1 and TR2 amplicons were observed for other S. enterica serovars, such as Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Enteritidis, and Salmonella enterica serovar Paratyphi A, B, and C. DNA sequencing of the amplified VNTR regions substantiated these results, suggesting the high stability of the multiplex PCR assay. The multiplex-PCR-based VNTR profiling developed in this study provides a simple, rapid, reproducible, and high-resolution molecular tool for the epidemiological analysis of S. enterica serovar Typhi strains.

Vaccination against Salmonella Infection: the Mucosal Way.

Science.gov (United States)

Gayet, Rémi; Bioley, Gilles; Rochereau, Nicolas; Paul, Stéphane; Corthésy, Blaise

2017-09-01

Salmonella enterica subspecies enterica includes several serovars infecting both humans and other animals and leading to typhoid fever or gastroenteritis. The high prevalence of associated morbidity and mortality, together with an increased emergence of multidrug-resistant strains, is a current global health issue that has prompted the development of vaccination strategies that confer protection against most serovars. Currently available systemic vaccine approaches have major limitations, including a reduced effectiveness in young children and a lack of cross-protection among different strains. Having studied host-pathogen interactions, microbiologists and immunologists argue in favor of topical gastrointestinal administration for improvement in vaccine efficacy. Here, recent advances in this field are summarized, including mechanisms of bacterial uptake at the intestinal epithelium, the assessment of protective host immunity, and improved animal models that closely mimic infection in humans. The pros and cons of existing vaccines are presented, along with recent progress made with novel formulations. Finally, new candidate antigens and their relevance in the refined design of anti- Salmonella vaccines are discussed, along with antigen vectorization strategies such as nanoparticles or secretory immunoglobulins, with a focus on potentiating mucosal vaccine efficacy. Copyright © 2017 American Society for Microbiology.

Spatial characterization of Leptospira spp. infection in equids from the Brejo Paraibano micro-region in Brazil

Directory of Open Access Journals (Sweden)

Ruy Brayner Oliveira Filho

2014-05-01

Full Text Available The present study, the first to spatially characterize Leptospira spp. infection among equids in the Brejo Paraibano micro-region of the Paraiba state in the northeast of Brazil, investigated 257 animals in 26 farms properties. Serum samples from 204 horses, 46 mules and seven donkeys were serologically diagnosed using the microscopic agglutination test (MAT. The distribution of Leptospira spp. was studied by employing specific antigens from 24 different Leptospira serovars. All farms were georeferenced and their distribution visualised on a map of the Brejo Paraibano micro-region. In addition, rainfall data were obtained from the same year, in which the sampling was performed. Among the 20 farms found to harbour animals with leptospirosis, 14 (70% exhibited low prevalence, five (25% medium prevalence and one (5%, high prevalence. Certain areas had a higher density of infected farms and required intervention to control the infection. Many serovars were widely distributed, while others were more common in particular areas. There was no significant association between the prevalence of Leptospira spp. infection and rainfall.

Antimicrobial drug resistance of Salmonella enterica serovar typhi in asia and molecular mechanism of reduced susceptibility to the fluoroquinolones

NARCIS (Netherlands)

Chau, Tran Thuy; Campbell, James Ian; Galindo, Claudia M.; van Minh Hoang, Nguyen; Diep, To Song; Nga, Tran Thu Thi; van Vinh Chau, Nguyen; Tuan, Phung Quoc; Page, Anne Laure; Ochiai, R. Leon; Schultsz, Constance; Wain, John; Bhutta, Zulfiqar A.; Parry, Christopher M.; Bhattacharya, Sujit K.; Dutta, Shanta; Agtini, Magdarina; Dong, Baiqing; Honghui, Yang; Anh, Dang Duc; Canh, Do Gia; Naheed, Aliya; Albert, M. John; Phetsouvanh, Rattanaphone; Newton, Paul N.; Basnyat, Buddha; Arjyal, Amit; La, Tran Thi Phi; Rang, Nguyen Ngoc; Phuong, Le Thi; van Be Bay, Phan; von Seidlein, Lorenz; Dougan, Gordon; Clemens, John D.; Vinh, Ha; Hien, Tran Tinh; Chinh, Nguyen Tran; Acosta, Camilo J.; Farrar, Jeremy; Dolecek, Christiane

2007-01-01

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar

Multidrug-Resistant Salmonella enterica Serovar Muenchen from Pigs and Humans and Potential Interserovar Transfer of Antimicrobial Resistance

OpenAIRE

Gebreyes, Wondwossen A.; Thakur, Siddhartha

2005-01-01

Salmonella serovars are important reservoirs of antimicrobial resistance. Recently, we reported on multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium strains among pigs with resistance to ampicillin, kanamycin, streptomycin, sulfamethoxazole, and tetracycline (resistance [R] type AKSSuT) and resistance to amoxicillin-clavulanic acid, ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (R type AxACSSuT). In the present study, 67 isolates (39 from humans...

Salmonella enterica Serovar Typhimurium and Escherichia coli Contamination of Root and Leaf Vegetables Grown in Soils with Incorporated Bovine Manure

Science.gov (United States)

Natvig, Erin E.; Ingham, Steven C.; Ingham, Barbara H.; Cooperband, Leslie R.; Roper, Teryl R.

2002-01-01

Bovine manure, with or without added Salmonella enterica serovar Typhimurium (three strains), was incorporated into silty clay loam (SCL) and loamy sand (LS) soil beds (53- by 114-cm surface area, 17.5 cm deep) and maintained in two controlled-environment chambers. The S. enterica serovar Typhimurium inoculum was 4 to 5 log CFU/g in manure-fertilized soil. The conditions in the two environmental chambers, each containing inoculated and uninoculated beds of manure-fertilized soil, simulated daily average Madison, Wis., weather conditions (hourly temperatures, rainfall, daylight, and humidity) for a 1 March or a 1 June manure application and subsequent vegetable growing seasons ending 9 August or 28 September, respectively. Core soil samples were taken biweekly from both inoculated and uninoculated soil beds in each chamber. Radishes, arugula, and carrots were planted in soil beds, thinned, and harvested. Soils, thinned vegetables, and harvested vegetables were analyzed for S. enterica serovar Typhimurium and Escherichia coli (indigenous in manure). After the 1 March manure application, S. enterica serovar Typhimurium was detected at low levels in both soils on 31 May, but not on vegetables planted 1 May and harvested 12 July from either soil. After the 1 June manure application, S. enterica serovar Typhimurium was detected in SCL soil on 7 September and on radishes and arugula planted in SCL soil on 15 August and harvested on 27 September. In LS soil, S. enterica serovar Typhimurium died at a similar rate (P ≥ 0.05) after the 1 June manure application and was less often detected on arugula and radishes harvested from this soil compared to the SCL soil. Pathogen levels on vegetables were decreased by washing. Manure application in cool (daily average maximum temperature of vegetables are not contaminated with S. enterica serovar Typhimurium. Manure application under warmer (daily average maximum temperature >20°C) summer conditions is not recommended when

Leptospira santorosai Serovar Shermani detergent extract induces an increase in fibronectin production through a Toll-like receptor 2-mediated pathway.

Science.gov (United States)

Tian, Ya-Chung; Hung, Cheng-Chieh; Li, Yi-Jung; Chen, Yung-Chang; Chang, Ming-Yang; Yen, Tzung-Hai; Hsu, Hsiang-Hao; Wu, Mai-Szu; Phillips, Aled; Yang, Chih-Wei

2011-03-01

Leptospirosis can activate inflammatory responses through Toll-like receptors (TLRs) and may cause renal tubulointerstitial fibrosis characterized by the accumulation of extracellular matrix (ECM). We have previously demonstrated that Leptospira santorosai serovar Shermani detergent extract stimulates ECM accumulation in vitro. The aim of this study was to examine the mechanistic basis of these previous observations and, in particular, to examine the potential involvement of TLRs. The addition of serovar Shermani detergent extract led to an increase in fibronectin gene expression and production. Inhibition of TLR2 but not TLR4 expression abrogated serovar Shermani detergent extract-mediated increases in fibronectin production. This response was also blocked by the knockdown of the gene expression of the TLR2 downstream transducers myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor-associated factor 6 (TRAF6). Serovar Shermani detergent extract also activated nuclear factor-κB, and its inhibition by curcumin-attenuated serovar Shermani detergent extract induced increases in fibronectin production. These effects were also mimicked by the specific TLR2 agonist, Pam(3)CsK(4), a response that was also abrogated by the knockdown of MyD88 and TRAF6. Similarly, the administration of live leptospires to cells also induced fibronectin production that was blocked by inhibition of TLR2 and MyD88 expression. In conclusion, serovar Shermani detergent extract can induce fibronectin production through the TLR2-associated cascade, providing evidence of an association between TLRs and leptospirosis-mediated ECM deposition.

The prevalence of lymphogranuloma venereum infection in men who have sex with men: results of a multicentre case finding study

Science.gov (United States)

Ward, H; Alexander, S; Carder, C; Dean, G; French, P; Ivens, D; Ling, C; Paul, J; Tong, W; White, J; Ison, C A

2009-01-01

Objective: To determine the prevalence of lymphogranuloma venereum (LGV) and non-LGV associated serovars of urethral and rectal Chlamydia trachomatis (CT) infection in men who have sex with men (MSM). Design: Multicentre cross-sectional survey. Setting: Four genitourinary medicine clinics in the United Kingdom from 2006–7. Subjects: 4825 urethral and 6778 rectal samples from consecutive MSM attending for sexual health screening. Methods: Urethral swabs or urine and rectal swabs were tested for CT using standard nucleic acid amplification tests. Chlamydia-positive specimens were sent to the reference laboratory for serovar determination. Main outcome: Positivity for both LGV and non-LGV associated CT serovars; proportion of cases that were symptomatic. Results: The positivity (with 95% confidence intervals) in rectal samples was 6.06% (5.51% to 6.66%) for non-LGV CT and 0.90% (0.69% to 1.16%) for LGV; for urethral samples 3.21% (2.74% to 3.76%) for non-LGV CT and 0.04% (0.01% to 0.16%) for LGV. The majority of LGV was symptomatic (95% of rectal, one of two urethral cases); non-LGV chlamydia was mostly symptomatic in the urethra (68%) but not in the rectum (16%). Conclusions: Chlamydial infections are common in MSM attending for sexual health screening, and the majority are non-LGV associated serovars. We did not identify a large reservoir of asymptomatic LGV in the rectum or urethra. Testing for chlamydia from the rectum and urethra should be included for MSM requesting a sexual health screen, but serovar-typing is not indicated in the absence of symptoms. We have yet to identify the source of most cases of LGV in the UK. PMID:19221105

Research note: Molecular subtyping of Salmonella enterica serovar Tshiongwe recently isolated in Malaysia during 2001-2002.

Science.gov (United States)

Thong, Kwai Lin; Bakeri, Shamsilawani Ahmad; Lai, Kin Seng; Koh, Yin Tee; Taib, Mohd Zainuldin; Lim, V K E; Yasin, Rohani Md

2004-03-01

Pulsed field gel electrophoresis (PFGE) and antimicrobial susceptibility analysis were undertaken on twenty-three strains of Salmonella enterica serovar Tshiongwe, an unusual serovar, which recently emerged in Malaysia. Antimicrobial susceptibility analysis showed that all the strains were sensitive to ampicilin, chloramphenicol, cotrimoxazole, and kanamycin. Twenty (87%) and 8 (3.5%) strains had resistance to tetracycline and streptomycin respectively. PFGE analysis subtyped 23 strains into 10 profiles (Dice coefficient of similarity, F = 0.7-1.0). The predominant profile, X1 was found in both clinical and environmental isolates and was widely distributed in different parts of Malaysia during the study period. In addition, isolates recovered from food, a hand-towel, apron and the surface of a table-top in one particular location had unique, indistinguishable profiles (X4/4a) and identical antibiograms. Similarly, isolates from cooked meat and a chopping board had PFGE profiles similar to some human isolates. These probably indicated cross-contamination and poor hygiene in food practices, hence contributing to Salmonellosis. Factors causing the emergence of this rare Salmonella serovar being responsible for food poisoning episodes during the study period remained unclear. The study reiterated the usefulness and versatility of PFGE in the molecular subtyping of this rare Salmonella serovar in Malaysia.

Serovar 4b complex predominates among Listeria monocytogenes isolates from imported aquatic products in China.

Science.gov (United States)

Chen, Jianshun; Chen, Qiaomiao; Jiang, Jianjun; Hu, Hongxia; Ye, Jiangbo; Fang, Weihuan

2010-01-01

Listeria monocytogenes, the causative organism of listeriosis, is primarily transmitted to humans through contaminated food. In this study, we examined 1275 batches of aquatic products imported from 29 countries and found that 36 batches from 8 countries were contaminated by Listeria (2.8%), with L. monocytogenes accounting for 2.6% (33/1275) and L. innocua for 0.2% (3/1275). Of the 23 selected L. monocytogenes isolates (from the 33 identified), 15 (65.2%) were of serovar 4b complex (4b, 4d, or 4e), three (13.0%) of 1/2a or 3a, four (17.4%) of 1/2b or 3b, and one (4.4%) of 1/2c or 3c. Notably, four of the 23 isolates belonged to epidemic clone I (ECI) and another four were associated with epidemic clone II (ECII), two highly clonal 4b clusters responsible for most of the documented listeriosis outbreaks. In the multilocus sequence typing scheme based on the concatenated genes gyrB-dapE-hisJ-sigB-ribC-purM-betL-gap-tuf, serovar 4b complex isolates from imported aquatic products exhibited significant genetic diversity. While the four ECI isolates were genetically related to those from Chinese diseased animals, both lacking one proline-rich repeat of ActA, the four ECII isolates were located between 1/2b or 3b strains. As the L. monocytogenes isolates from imported aquatic products possessed a nearly complete set of major infection-related genes, they demonstrated virulence potential in mouse model.

Specific Monoclonal Antibody Overcomes the Salmonella enterica Serovar Typhimurium's Adaptive Mechanisms of Intramacrophage Survival and Replication.

Directory of Open Access Journals (Sweden)

Swarmistha Devi Aribam

Full Text Available Salmonella-specific antibodies play an important role in host immunity; however, the mechanisms of Salmonella clearance by pathogen-specific antibodies remain to be completely elucidated since previous studies on antibody-mediated protection have yielded inconsistent results. These inconsistencies are at least partially attributable to the use of polyclonal antibodies against Salmonella antigens. Here, we developed a new monoclonal antibody (mAb-449 and identified its related immunogen that protected BALB/c mice from infection with Salmonella enterica serovar Typhimurium. In addition, these data indicate that the mAb-449 immunogen is likely a major protective antigen. Using in vitro infection studies, we also analyzed the mechanism by which mAb-449 conferred host protection. Notably, macrophages infected with mAb-449-treated S. Typhimurium showed enhanced pathogen uptake compared to counterparts infected with control IgG-treated bacteria. Moreover, these macrophages produced elevated levels of pro-inflammatory cytokine TNFα and nitric oxide, indicating that mAb-449 enhanced macrophage activation. Finally, the number of intracellular bacteria in mAb-449-activated macrophages decreased considerably, while the opposite was found in IgG-treated controls. Based on these findings, we suggest that, although S. Typhimurium has the potential to survive and replicate within macrophages, host production of a specific antibody can effectively mediate macrophage activation for clearance of intracellular bacteria.

Infection with Salmonella enterica Serovar Typhimurium Leads to Increased Proportions of F4/80+ Red Pulp Macrophages and Decreased Proportions of B and T Lymphocytes in the Spleen.

Directory of Open Access Journals (Sweden)

Kristin L Rosche

Full Text Available Infection of mice with Salmonella enterica serovar Typhimurium (Salmonella causes systemic inflammatory disease and enlargement of the spleen (splenomegaly. Splenomegaly has been attributed to a general increase in the numbers of phagocytes, lymphocytes, as well as to the expansion of immature CD71+Ter119+ reticulocytes. The spleen is important for recycling senescent red blood cells (RBCs and for the capture and eradication of blood-borne pathogens. Conservation of splenic tissue architecture, comprised of the white pulp (WP, marginal zone (MZ, and red pulp (RP is essential for initiation of adaptive immune responses to captured pathogens. Using flow cytometry and four color immunofluorescence microscopy (IFM, we show that Salmonella-induced splenomegaly is characterized by drastic alterations of the splenic tissue architecture and cell population proportions, as well as in situ cell distributions. A major cause of splenomegaly appears to be the significant increase in immature RBC precursors and F4/80+ macrophages that are important for recycling of heme-associated iron. In contrast, the proportions of B220+, CD4+ and CD8+ lymphocytes, as well as MZ MOMA+ macrophages decrease significantly as infection progresses. Spleen tissue sections show visible tears and significantly altered tissue architecture with F4/80+ macrophages and RBCs expanding beyond the RP and taking over most of the spleen tissue. Additionally, F4/80+ macrophages actively phagocytose not only RBCs, but also lymphocytes, indicating that they may contribute to declining lymphocyte proportions during Salmonella infection. Understanding how these alterations of spleen microarchitecture impact the generation of adaptive immune responses to Salmonella has implications for understanding Salmonella pathogenesis and for the design of more effective Salmonella-based vaccines.

Infection with Salmonella enterica Serovar Typhimurium Leads to Increased Proportions of F4/80+ Red Pulp Macrophages and Decreased Proportions of B and T Lymphocytes in the Spleen.

Science.gov (United States)

Rosche, Kristin L; Aljasham, Alanoud T; Kipfer, James N; Piatkowski, Bryan T; Konjufca, Vjollca

2015-01-01

Infection of mice with Salmonella enterica serovar Typhimurium (Salmonella) causes systemic inflammatory disease and enlargement of the spleen (splenomegaly). Splenomegaly has been attributed to a general increase in the numbers of phagocytes, lymphocytes, as well as to the expansion of immature CD71+Ter119+ reticulocytes. The spleen is important for recycling senescent red blood cells (RBCs) and for the capture and eradication of blood-borne pathogens. Conservation of splenic tissue architecture, comprised of the white pulp (WP), marginal zone (MZ), and red pulp (RP) is essential for initiation of adaptive immune responses to captured pathogens. Using flow cytometry and four color immunofluorescence microscopy (IFM), we show that Salmonella-induced splenomegaly is characterized by drastic alterations of the splenic tissue architecture and cell population proportions, as well as in situ cell distributions. A major cause of splenomegaly appears to be the significant increase in immature RBC precursors and F4/80+ macrophages that are important for recycling of heme-associated iron. In contrast, the proportions of B220+, CD4+ and CD8+ lymphocytes, as well as MZ MOMA+ macrophages decrease significantly as infection progresses. Spleen tissue sections show visible tears and significantly altered tissue architecture with F4/80+ macrophages and RBCs expanding beyond the RP and taking over most of the spleen tissue. Additionally, F4/80+ macrophages actively phagocytose not only RBCs, but also lymphocytes, indicating that they may contribute to declining lymphocyte proportions during Salmonella infection. Understanding how these alterations of spleen microarchitecture impact the generation of adaptive immune responses to Salmonella has implications for understanding Salmonella pathogenesis and for the design of more effective Salmonella-based vaccines.

Method for the detection of Salmonella enterica serovar Enteritidis

Science.gov (United States)

Agron, Peter G.; Andersen, Gary L.; Walker, Richard L.

2008-10-28

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.

Investigating Salmonella Eko from Various Sources in Nigeria by Whole Genome Sequencing to Identify the Source of Human Infections.

Directory of Open Access Journals (Sweden)

Pimlapas Leekitcharoenphon

Full Text Available Twenty-six Salmonella enterica serovar Eko isolated from various sources in Nigeria were investigated by whole genome sequencing to identify the source of human infections. Diversity among the isolates was observed and camel and cattle were identified as the primary reservoirs and the most likely source of the human infections.

Colicinogeny in Salmonella serovars isolated in Brazil

Directory of Open Access Journals (Sweden)

Leila Carvalho Campos

1988-06-01

Full Text Available A study of colicinogeny was made in 748 strains of Salmonella (97 serovars isolated from different sources; human (291, animal (119, environmental (141, food (102 and animal feed (95. Colicin production was detected in 64 strains (8.6%, particularly isolated from foods (30.4%. Col. E1 (53 and Ia (44 were the most frequently observed, especially in S. agona for environment and food sources. Col V production was identified in 5 strains of S. typhimurium within 8 producer cultures isolated from humans. Its relationship with the sources and serovars of Salmonella are discussed.Investigou-se a produção de colicina em 748 amostras de Salmonella (97 sorovares advindas de díferentes fontes: humana (291, animal (119, ambiental (141, de alimentos (102 e rações (95. Detectaram-se 64 amostras (8,6% colicinogênicas, particularmente isoladas de alimentos (30,4%. ColE1 (53 e Ia (44 foram as mais freqüentes, especialmente no sorovar S, agona, de origem ambiental e de alimentos. Identificou-se também a produção de col V em 5 amostras de S. typhimurium dentre 8 culturas produtoras de origem humana. Discute-se a relação entre a capacidade colicinogênica e as fontes e sorovares de Salmonella.

Genetic lineages of Salmonella enterica serovar Kentucky spreading in pet reptiles.

Science.gov (United States)

Zając, Magdalena; Wasyl, Dariusz; Hoszowski, Andrzej; Le Hello, Simon; Szulowski, Krzysztof

2013-10-25

The purpose of the study was to define genetic diversity of reptilian Salmonella enterica serovar (S.) Kentucky isolates and their epidemiological relations to the ones from poultry, food, and environmental origin in Poland. Between 2010 and 2012 twenty-four S. Kentucky isolates derived from snakes (N=8), geckos (N=7), chameleons (N=4), agamas (N=1), lizard (N=1), and environmental swabs taken from reptile exhibition (N=3) were identified. They were characterized with antimicrobial minimal inhibitory concentration testing, XbaI-PFGE and MLST typing. The profiles compared to S. Kentucky available in BioNumerics local laboratory database (N=40) showed 67.3% of relatedness among reptile isolates. Three genetic lineages were defined. The first lineage gathered 20 reptile isolates with 83.4% of similarity and wild-type MICs for all antimicrobials tested but streptomycin in single case. The remaining three reptilian and one post-exhibition environment S. Kentucky isolates were clustered (87.2%) with isolates originating from poultry, mainly turkey, food, and environment and presented variable non-wild type MICs to numerous antimicrobials. The third S. Kentucky lineage was composed of two isolates from feed (96.3%). The results suggest diverse sources and independent routes of infection. Most of the isolates belonged to reptile-associated clones spread both horizontally and vertically. Simultaneously, PFGE profiles and MLST type indistinguishable from the ones observed in poultry point out carnivore reptiles as possible vector of infection with multidrug and high-level ciprofloxacin resistant (MIC≥8 mg/L) S. Kentucky. Public awareness and education are required to prevent potential reptile-associated S. Kentucky infections in humans. Copyright © 2013 Elsevier B.V. All rights reserved.

Post-operative Salmonella surgical site infection in a dog.

Science.gov (United States)

Kent, Marc; Boozer, Lindsay; Glass, Eric N; Sanchez, Susan; Platt, Simon R; Freeman, Lisa M

2017-09-01

Following decompressive surgery for degenerative lumbosacral stenosis, a 6-year-old German shepherd dog developed a subcutaneous infection at the surgical site and discospondylitis at the lumbosacral intervertebral disc. Salmonella enterica subsp. enterica, serotype Dublin was recovered from the surgical site. Salmonella of a different serovar was isolated from a sample of the raw meat-based diet that the owner fed the dog.

Salmonella enterica serovar Enteritidis enterocolitis during late stages of gestation induces an adverse pregnancy outcome in the murine model.

Directory of Open Access Journals (Sweden)

Mariángeles Noto Llana

Full Text Available Foodborne diseases caused by Salmonella enterica serovar Enteritidis (S. Enteritidis are a significant health problem. Pregnancy, state of immunological tolerance, is a predisposing condition for the development of infections with intracellular pathogens. Salmonella species can cause pregnancy complications such as chorioamnionitis, transplacental fetal infection, pre term labor, abortions, neonatal and maternal septicemia. However, the specific mechanisms by which Salmonella infections trigger these alterations are not clear. In the present work, using a self-limiting enterocolitis murine model, we show that the ingestion of a low dose of S. Enteritidis at late stages of pregnancy (day 15 of gestation is sufficient to induce massive maternal infection. We found that Salmonella infection leads to 40% of pre term delivery, 33% of abortion and fetal growth restriction. Placental dysfunction during S. Enteritidis enterocolitis was confirmed through cellular infiltration and hypoxia markers (MPO activity and COX-1 and COX-2 expression, respectively. Apoptosis in placental tissue due to Salmonella infection was also evident at day 18 of gestation when investigated by morphometric procedure, DNA fragmentation and Fas/FasL expression. Also, the expression of IFN-γ, TNF-α, IL-17 and IL-10 was up regulated in response to Salmonella not only in placenta, but also in amniotic fluid and maternal serum. Altogether, our results demonstrate that S. Enteritidis enterocolitis during late stages of gestation causes detrimental effect on pregnancy outcome.

Prevalence and antimicrobial resistance of Salmonella serovars isolated from poultry in Ghana

DEFF Research Database (Denmark)

Andoh, Linda A.; Dalsgaard, Anders; Obiri-Danso, K.

2016-01-01

Poultry are possible sources of non-typhoidal Salmonella serovars which may cause foodborne human disease. We conducted a cross-sectional study to determine the prevalence of Salmonella serovars in egg-laying hens and broilers at the farm level and their susceptibility to antimicrobials commonly...... of antimicrobials). Of the resistant strains (n = 57), the most significant were to nalidixic acid (89·5%), tetracycline (80·7%), ciprofloxacin (64·9%), sulfamethazole (42·1%), trimethoprim (29·8%) and ampicillin (26·3%). All S. Kentucky strains were resistant to more than two antimicrobials and shared common...

Horizontal gene transfer of a ColV plasmid has resulted in a dominant avian clonal type of Salmonella enterica serovar Kentucky.

Directory of Open Access Journals (Sweden)

Timothy J Johnson

Full Text Available Salmonella enterica continues to be a significant cause of foodborne gastrointestinal illness in humans. A wide variety of Salmonella serovars have been isolated from production birds and from retail poultry meat. Recently, though, S. enterica subsp. enterica serovar Kentucky has emerged as one of the prominent Salmonella serovars isolated from broiler chickens. Recent work suggests that its emergence apparently coincides with its acquisition of a ColV virulence plasmid. In the present study, we examined 902 Salmonella isolates belonging to 59 different serovars for the presence of this plasmid. Of the serovars examined, the ColV plasmid was found only among isolates belonging to the serovars Kentucky (72.9%, Typhimurium (15.0% and Heidelberg (1.7%. We demonstrated that a single PFGE clonal type of S. Kentucky harbors this plasmid, and acquisition of this plasmid by S. Kentucky significantly increased its ability to colonize the chicken cecum and cause extraintestinal disease. Comparison of the completed sequences of three ColV plasmids from S. Kentucky isolated from different geographical locales, timepoints and sources revealed a nearly identical genetic structure with few single nucleotide changes or insertions/deletions. Overall, it appears that the ColV plasmid was recently acquired by a single clonal type S. Kentucky and confers to its host enhanced colonization and fitness capabilities. Thus, the potential for horizontal gene transfer of virulence and fitness factors to Salmonella from other enteric bacteria exists in poultry, representing a potential human health hazard.

MHC class II DRB diversity predicts antigen recognition and is associated with disease severity in California sea lions naturally infected with Leptospira interrogans

Science.gov (United States)

Acevedo-Whitehouse, Karina; Gulland, Frances; Bowen, Lizabeth

2018-01-01

We examined the associations between California sea lion MHC class II DRB (Zaca-DRB) configuration and diversity, and leptospirosis. As Zaca-DRB gene sequences are involved with antigen presentation of bacteria and other extracellular pathogens, we predicted that they would play a role in determining responses to these pathogenic spirochaetes. Specifically, we investigated whether Zaca-DRB diversity (number of genes) and configuration (presence of specific genes) explained differences in disease severity, and whether higher levels of Zaca-DRB diversity predicted the number of specific Leptospira interrogans serovars that a sea lion's serum would react against. We found that serum from diseased sea lions with more Zaca-DRB loci reacted against a wider array of serovars. Specific Zaca-DRB loci were linked to reactions with particular serovars. Interestingly, sea lions with clinical manifestation of leptospirosis that had higher numbers of Zaca-DRB loci were less likely to recover from disease than those with lower diversity, and those that harboured Zaca-DRB.C or –G were 4.5 to 5.3 times more likely to die from leptospirosis, regardless of the infective serovars. We propose that for leptospirosis, a disadvantage of having a wider range of antigen presentation might be increased disease severity due to immunopathology. Ours is the first study to examine the importance of Zaca-DRB diversity for antigen detection and disease severity following natural exposure to infective leptospires.

New Leptospira serovar Sokoine of serogroup Icterohaemorrhagiae from cattle in Tanzania

NARCIS (Netherlands)

Mgode, G. F.; Machang'u, R. S.; Goris, M. G.; Engelbert, M.; Sondij, S.; Hartskeerl, R. A.

2006-01-01

The prevalence of leptospirosis is generally high in domestic animals and rodents in Tanzania. Identification of Leptospira isolates from cattle was carried out to establish prevalent Leptospira serovars. Serological typing was done based on monoclonal antibodies and the standard cross-agglutination

Prevalence and characterization of multi-drug resistant Salmonella Enterica serovar Gallinarum biovar Pullorum and Gallinarum from chicken

Directory of Open Access Journals (Sweden)

Md. Shafiullah Parvej

2016-01-01

Full Text Available Aim: Salmonella is an important zoonotic pathogen responsible for animal and human diseases. The aim of the present study was to determine the prevalence and stereotyping of Salmonella isolates isolated from apparently healthy poultry. Furthermore, the clonal relatedness among the isolated Salmonella serovars was assessed. Materials and Methods: A total of 150 cloacal swab samples from apparently healthy chickens were collected, and were subjected for the isolation and identification of associated Salmonella organisms. The isolated colonies were identified and characterized on the basis of morphology, cultural characters, biochemical tests, slide agglutination test, polymerase chain reaction, and pulsed-field gel electrophoresis (PFGE. Antibiotic sensitivity patterns were also investigated using commonly used antibiotics. Results: Of the 150 samples, 11 (7.33% produced characteristics pink colony with black center on XLD agar medium, and all were culturally and biochemically confirmed to be Salmonella. All possessed serovar-specific gene SpeF and reacted uniformly with group D antisera, suggesting that all of the isolates were Salmonella Enterica serovar Gallinarum, biovar Pullorum and/or Gallinarum. Antimicrobial susceptibility testing revealed that 54.54% of the isolated Salmonella Enterica serovars were highly sensitive to ciprofloxacin, whereas the 81.81% isolates were resistant to amoxycillin, doxycycline, kanamycin, gentamycin, and tetracycline. Pulsed-field gel electrophoresis of the XbaI-digested genomic DNA exhibited identical banding patterns, suggesting that the multidrug resistant Salmonella Enterica serovars occurring in commercial layers are highly clonal in Bangladesh. Conclusion: The present study was conducted to find out the prevalence of poultry Salmonella in layer chicken and to find out the clonal relationship among them. The data in this study suggest the prevalence of Salmonella Enterica, which is multidrug resistant and

VNTR molecular typing of salmonella enterica serovar typhi isolates in Kathmandu valley

Directory of Open Access Journals (Sweden)

B Acharya

2012-03-01

Full Text Available Background: Typhoid fever continues to be a worldwide health problem, especially in developing countries. Effective epidemiological surveillance is needed to monitor the presence and spread of disease. Materials and Methods: Variable number tandem repeats (VNTR was performed for Salmonella enterica serovar typhi by multiplex-PCR in 28 Nepalese isolates of sporadic typhoid fever. Results: From all 28 total isolates, we could identify 12 VNTR profiles among the isolates, signifying multiple variants in circulation within the region. Conclusion: The VNTR-based typing assay for serovar typhi isolates can be used during an outbreak of enteric fever. The typing could eventually form the basis of an effective epidemiological surveillance system for developing rational strategies to control typhoid fever. DOI: http://dx.doi.org/10.3126/jpn.v2i3.6026 JPN 2012; 2(3: 220-223

Pronounced susceptibility to infection by Salmonella enterica serovar Typhimurium in mice chronically exposed to lead correlates with a shift to Th2-type immune responses

International Nuclear Information System (INIS)

Fernandez-Cabezudo, Maria J.; Ali, Sumaya A.E.; Ullah, Azim; Hasan, Mohammed Y.; Kosanovic, Melita; Fahim, Mohamed A.; Adem, Abdu; Al-Ramadi, Basel K.

2007-01-01

Persistent exposure to inorganic lead (Pb) is known to adversely affect the immune system. In the present study, we assessed the effect of chronic Pb exposure on susceptibility to infection by the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. Mice were exposed to 10 mM Pb-acetate in drinking water for ∼ 16 weeks, resulting in a significant level of Pb in the blood (106.2 ± 8.9 μg/dl). Pb exposure rendered mice susceptible to Salmonella infection, manifested by increased bacterial burden in target organs and heightened mortality. Flow cytometric analysis of the splenic cellular composition in normal and Pb-exposed mice revealed no gross alteration in the ratios of B and T lymphocytes or myeloid cells. Similarly, the capacity of B and T cells to upregulate the expression of activation antigens in response to mitogenic or inflammatory stimuli was not hindered by Pb exposure. Analysis of the ability of ex vivo-cultured splenocytes to secrete cytokines demonstrated a marked reduction in IFN-γ and IL-12p40 production associated with Pb exposure. In contrast, secretion of IL-4 by splenocytes of Pb-treated mice was 3- to 3.6-fold higher than in normal mice. The increased capacity to produce IL-4 correlated with a shift in the in vivo anti-Salmonella antibody response from the protective IgG2a isotype to the Th2-induced IgG1 isotype. We conclude that chronic exposure to high levels of Pb results in a state of immunodeficiency which is not due to an overt cytotoxic or immunosuppressive mechanism, but rather is largely caused by a shift in immune responsiveness to Th2-type reactions

ramR Mutations Affecting Fluoroquinolone Susceptibility in Epidemic Multidrug-Resistant Salmonella enterica Serovar Kentucky ST198

Directory of Open Access Journals (Sweden)

Axel eCloeckaert

2013-07-01

Full Text Available A screening for non-target mutations affecting fluoroquinolone susceptibility was conducted in epidemic multidrug-resistant Salmonella enterica serovar Kentucky ST198. Among a panel of representative isolates (n=30, covering the epidemic, only three showed distinct mutations in ramR resulting in enhanced expression of genes encoding the AcrAB-TolC efflux system and low increase in ciprofloxacin MIC. No mutations were detected in other regulatory regions of this efflux system. Ciprofloxacin resistance in serovar Kentucky ST198 is thus currently mainly due to multiple target gene mutations.

Kinetics of Leptospira interrogans infection in hamsters after intradermal and subcutaneous challenge.

Directory of Open Access Journals (Sweden)

Mariana L Coutinho

2014-11-01

Full Text Available Leptospirosis is a zoonosis caused by highly motile, helically shaped bacteria that penetrate the skin and mucous membranes through lesions or abrasions, and rapidly disseminate throughout the body. Although the intraperitoneal route of infection is widely used to experimentally inoculate hamsters, this challenge route does not represent a natural route of infection.Here we describe the kinetics of disease and infection in hamster model of leptospirosis after subcutaneous and intradermal inoculation of Leptospira interrogans serovar Copenhageni, strain Fiocruz L1-130. Histopathologic changes in and around the kidney, including glomerular and tubular damage and interstitial inflammatory changes, began on day 5, and preceded deterioration in renal function as measured by serum creatinine. Weight loss, hemoconcentration, increased absolute neutrophil counts (ANC in the blood and hepatic dysfunction were first noted on day 6. Vascular endothelial growth factor, a serum marker of sepsis severity, became elevated during the later stages of infection. The burden of infection, as measured by quantitative PCR, was highest in the kidney and peaked on day 5 after intradermal challenge and on day 6 after subcutaneous challenge. Compared to subcutaneous challenge, intradermal challenge resulted in a lower burden of infection in both the kidney and liver on day 6, lower ANC and less weight loss on day 7.The intradermal and subcutaneous challenge routes result in significant differences in the kinetics of dissemination and disease after challenge with L. interrogans serovar Copenhageni strain Fiocruz L1-130 at an experimental dose of 2×106 leptospires. These results provide new information regarding infection kinetics in the hamster model of leptospirosis.

Complete Genome Sequence of a Human-Invasive Salmonella enterica Serovar Typhimurium Strain of the Emerging Sequence Type 213 Harboring a Multidrug Resistance IncA/C Plasmid and a blaCMY-2-Carrying IncF Plasmid.

Science.gov (United States)

Silva, Claudia; Calva, Edmundo; Calva, Juan J; Wiesner, Magdalena; Fernández-Mora, Marcos; Puente, José L; Vinuesa, Pablo

2015-11-12

Salmonella enterica subsp. enterica serovar Typhimurium strain 33676 was isolated in Mexico City, Mexico, from a patient with a systemic infection, and its complete genome sequence was determined using PacBio single-molecule real-time technology. Strain 33676 harbors an IncF plasmid carrying the extended-spectrum cephalosporin gene blaCMY-2 and a multidrug resistance IncA/C plasmid. Copyright © 2015 Silva et al.

Antimicrobial Drug Resistance of Salmonella enterica Serovar Typhi in Asia and Molecular Mechanism of Reduced Susceptibility to the Fluoroquinolones▿

Science.gov (United States)

Chau, Tran Thuy; Campbell, James Ian; Galindo, Claudia M.; Van Minh Hoang, Nguyen; Diep, To Song; Nga, Tran Thu Thi; Van Vinh Chau, Nguyen; Tuan, Phung Quoc; Page, Anne Laure; Ochiai, R. Leon; Schultsz, Constance; Wain, John; Bhutta, Zulfiqar A.; Parry, Christopher M.; Bhattacharya, Sujit K.; Dutta, Shanta; Agtini, Magdarina; Dong, Baiqing; Honghui, Yang; Anh, Dang Duc; Canh, Do Gia; Naheed, Aliya; Albert, M. John; Phetsouvanh, Rattanaphone; Newton, Paul N.; Basnyat, Buddha; Arjyal, Amit; La, Tran Thi Phi; Rang, Nguyen Ngoc; Phuong, Le Thi; Van Be Bay, Phan; von Seidlein, Lorenz; Dougan, Gordon; Clemens, John D.; Vinh, Ha; Hien, Tran Tinh; Chinh, Nguyen Tran; Acosta, Camilo J.; Farrar, Jeremy; Dolecek, Christiane

2007-01-01

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar Typhi strains collected in southern Vietnam, the proportion of multidrug resistance has remained high since 1993 (50% in 2004) and there was a dramatic increase in nalidixic acid resistance between 1993 (4%) and 2005 (97%). In a cross-sectional sample of 381 serovar Typhi strains from 8 Asian countries, Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, and central Vietnam, collected in 2002 to 2004, various rates of multidrug resistance (16 to 37%) and nalidixic acid resistance (5 to 51%) were found. The eight Asian countries involved in this study are home to approximately 80% of the world's typhoid fever cases. These results document the scale of drug resistance across Asia. The Ser83→Phe substitution in GyrA was the predominant alteration in serovar Typhi strains from Vietnam (117/127 isolates; 92.1%). No mutations in gyrB, parC, or parE were detected in 55 of these strains. In vitro time-kill experiments showed a reduction in the efficacy of ofloxacin against strains harboring a single-amino-acid substitution at codon 83 or 87 of GyrA; this effect was more marked against a strain with a double substitution. The 8-methoxy fluoroquinolone gatifloxacin showed rapid killing of serovar Typhi harboring both the single- and double-amino-acid substitutions. PMID:17908946

Actin re-organization induced by Chlamydia trachomatis serovar D--evidence for a critical role of the effector protein CT166 targeting Rac.

Directory of Open Access Journals (Sweden)

Jessica Thalmann

Full Text Available The intracellular bacterium Chlamydia trachomatis causes infections of urogenital tract, eyes or lungs. Alignment reveals homology of CT166, a putative effector protein of urogenital C. trachomatis serovars, with the N-terminal glucosyltransferase domain of clostridial glucosylating toxins (CGTs. CGTs contain an essential DXD-motif and mono-glucosylate GTP-binding proteins of the Rho/Ras families, the master regulators of the actin cytoskeleton. CT166 is preformed in elementary bodies of C. trachomatis D and is detected in the host-cell shortly after infection. Infection with high MOI of C. trachomatis serovar D containing the CT166 ORF induces actin re-organization resulting in cell rounding and a decreased cell diameter. A comparable phenotype was observed in HeLa cells treated with the Rho-GTPase-glucosylating Toxin B from Clostridium difficile (TcdB or HeLa cells ectopically expressing CT166. CT166 with a mutated DXD-motif (CT166-mut exhibited almost unchanged actin dynamics, suggesting that CT166-induced actin re-organization depends on the glucosyltransferase motif of CT166. The cytotoxic necrotizing factor 1 (CNF1 from E. coli deamidates and thereby activates Rho-GTPases and transiently protects them against TcdB-induced glucosylation. CNF1-treated cells were found to be protected from TcdB- and CT166-induced actin re-organization. CNF1 treatment as well as ectopic expression of non-glucosylable Rac1-G12V, but not RhoA-G14A, reverted CT166-induced actin re-organization, suggesting that CT166-induced actin re-organization depends on the glucosylation of Rac1. In accordance, over-expression of CT166-mut diminished TcdB induced cell rounding, suggesting shared substrates. Cell rounding induced by high MOI infection with C. trachomatis D was reduced in cells expressing CT166-mut or Rac1-G12V, and in CNF1 treated cells. These observations indicate that the cytopathic effect of C. trachomatis D is mediated by CT166 induced Rac1 glucosylation

Chlamydia trachomatis ompA genotypes in male patients with urethritis in Greece: conservation of the serovar distribution and evidence for mixed infections with Chlamydophila abortus.

Science.gov (United States)

Psarrakos, Panagiotis; Papadogeorgakis, Eleni; Sachse, Konrad; Vretou, Evangelia

2011-08-01

PCR amplification and nucleotide sequencing of the ompA gene of Chlamydia trachomatis were used to determine the prevalence and distribution of genotypes in 51 urine and urethral specimens from Greek male patients with urethritis, that were positive by the COBAS Amplicor test. A single C. trachomatis serovar was identified in 43 of the 51 amplified samples. Serovars F and E were the most prevalent (both 12, 28%), followed by D (9, 21%), G (4, 9%), B and K (both 2, 5%) and H and J (both 1, 2%). Over one third of the samples bared a variant ompA genotype that had been previously identified in other areas worldwide. Two results in this study, both observed for the first time, were of particular interest. First, the emergence of the unique variant genotype D/Ep6 (X77364.2) identified in 3 urethral samples. Second, the ompA genotype OCLH196 of the animal pathogen Chlamydophila abortus as well as a 23S rRNA gene fragment of this species detected by the assay ArrayTube™ was found in 7 urethral samples. The implications resulting from this observation for the health of the general population are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Normalización y validación de ensayos inmunoenzimáticos para cuantificar IgG humana antileptospira serovares canicola canicola, icterohaemorrhagiae copenhageni y pomona mozdok.

Directory of Open Access Journals (Sweden)

Xenia Ferriol

2001-06-01

Full Text Available Con el objetivo de evaluar la respuesta inmune inducida por la vacuna cubana vax-SPIRAL se desarrollaron tres ELISAs de tipo indirecto para la cuantificación de IgG humana antileptospira, en el cual se emplearon como antígenos de captura las células enteras de Leptospira interrogans de los serovares canicola canicola, icterohaemorrhagiae copenhageni y pomona mozdok, inactivadas con formaldehído y posteriormente desecadas a 33 °C durante 16-20 h en placas para ELISA. Para la cuantificación se empleó un suero estándar al que se le asignaron unidades arbitrarias, correspondientes al recíproco del título obtenido por microaglutinación (MAT. Estos fueron 31, 12 y 58 U/mL respectivamente para los tres serovares señalados que se incluyen en el preparado vacunal. Se utilizó un conjugado anti IgG humana-peroxidasa, el cual se une a los anticuerpos específicos contra cada serovar, la reacción se evidencia por la acción de la enzima sobre la mezcla sustratocromógeno (ortofenilendiamina que genera color. El método normalizado se validó para los tres serovares; la precisión intra e interensayos fueron excelentes, con coeficientes de variación inferiores al 10%. Las desviaciones de la recuperación y linealidad fueron también inferiores al 10%. El suero control se ubicaron para los tres serovares en la zona de mayor interés para las muestras. Los ELISAs mostraron un 100% de sensibilidad para los tres serovares y se obtuvieron valores de 93,33% de especificidad para los serovares canicola canicola e icterohaemorrhagiae copenagheni y de 100% para el serovar pomona mozdok. El límite de detección para cada uno de los serovares fue de 0,478; 0,127 y 0,632 U/mL respectivamente.

[Listeria monocytogenes nosocomial infection in the maternity ward].

Science.gov (United States)

Jean, D; Croize, J; Hirtz, P; Legeais, C; Pelloux, I; Favier, M; Mallaret, M R; Le Noc, P; Rambaud, P

1991-01-01

Nosocomial infection with Listeria monocytogenes 4b occurred in January 1990 in a maternity hospital in Grenoble. The 3 patients involved were born within a 24 hour-interval. The premature newborn responsible for contamination was asymptomatic. Two other newborns without any perinatal infectious risk presented with meningitis, one on the 5th day of life in the maternity hospital, the other one on the 11th day while already at home. The 3 strains of Listeria had the same serovar and lysovar. Epidemiologic investigations led to suspect a contamination in the delivery room and during the care of the children. Strict respect of hygiene orders is imperative to avoid nosocomial infections.

A Case of Reactive Arthritis Associated With Lymphogranuloma Venereum Infection in a Woman.

Science.gov (United States)

Foschi, Claudio; Banzola, Nicoletta; Gaspari, Valeria; D'Antuono, Antonietta; Cevenini, Roberto; Marangoni, Antonella

2016-09-01

We report the first case of reactive arthritis associated with lymphogranuloma venereum (LGV) in an Italian human immunodeficiency virus-negative woman with urogenital and rectal Chlamydia trachomatis L2 serovar infection. The LGV-associated arthritis has to be considered even when classic symptoms of arthritis are missing and in case of asymptomatic or cryptic LGV localizations.

Characterization of chicken spleen transcriptome after infection with Salmonella enterica serovar Enteritidis.

Directory of Open Access Journals (Sweden)

Marta Matulova

Full Text Available In this study we were interested in identification of new markers of chicken response to Salmonella Enteritidis infection. To reach this aim, gene expression in the spleens of naive chickens and those intravenously infected with S. Enteritidis with or without previous oral vaccination was determined by 454 pyrosequencing of splenic mRNA/cDNA. Forty genes with increased expression at the level of transcription were identified. The most inducible genes encoded avidin (AVD, extracellular fatty acid binding protein (EXFABP, immune responsive gene 1 (IRG1, chemokine ah221 (AH221, trappin-6-like protein (TRAP6 and serum amyloid A (SAA. Using cDNA from sorted splenic B-lymphocytes, macrophages, CD4, CD8 and γδ T-lymphocytes, we found that the above mentioned genes were preferentially expressed in macrophages. AVD, EXFABP, IRG1, AH221, TRAP6 and SAA were induced also in the cecum of chickens orally infected with S. Enteritidis on day 1 of life or day 42 of life. Unusual results were obtained for the immunoglobulin encoding transcripts. Prior to the infection, transcripts coding for the constant parts of IgM, IgY, IgA and Ig light chain were detected in B-lymphocytes. However, after the infection, immunoglobulin encoding transcripts were expressed also by T-lymphocytes and macrophages. Expression of AVD, EXFABP, IRG1, AH221, TRAP6, SAA and all immunoglobulin genes can be therefore used for the characterization of the course of S. Enteritidis infection in chickens.

Expression and characterization of an iron-regulated hemin-binding protein, HbpA, from Leptospira interrogans serovar Lai.

Science.gov (United States)

Asuthkar, Swapna; Velineni, Sridhar; Stadlmann, Johannes; Altmann, Friedrich; Sritharan, Manjula

2007-09-01

In an earlier study, based on the ferric enterobactin receptor FepA of Escherichia coli, we identified and modeled a TonB-dependent outer membrane receptor protein (LB191) from the genome of Leptospira interrogans serovar Lai. Based on in silico analysis, we hypothesized that this protein was an iron-dependent hemin-binding protein. In this study, we provide experimental evidence to prove that this protein, termed HbpA (hemin-binding protein A), is indeed an iron-regulated hemin-binding protein. We cloned and expressed the full-length 81-kDa recombinant rHbpA protein and a truncated 55-kDa protein from L. interrogans serovar Lai, both of which bind hemin-agarose. Assay of hemin-associated peroxidase activity and spectrofluorimetric analysis provided confirmatory evidence of hemin binding by HbpA. Immunofluorescence studies by confocal microscopy and the microscopic agglutination test demonstrated the surface localization and the iron-regulated expression of HbpA in L. interrogans. Southern blot analysis confirmed our earlier observation that the hbpA gene was present only in some of the pathogenic serovars and was absent in Leptospira biflexa. Hemin-agarose affinity studies showed another hemin-binding protein with a molecular mass of approximately 44 kDa, whose expression was independent of iron levels. This protein was seen in several serovars, including nonpathogenic L. biflexa. Sequence analysis and immunoreactivity with specific antibodies showed this protein to be LipL41.

Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

DEFF Research Database (Denmark)

Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.; Le Hello, Simon

2016-01-01

It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally struc...

Temperature and oxygen dependent metabolite utilization by Salmonella enterica serovars Derby and Mbandaka.

Directory of Open Access Journals (Sweden)

Matthew R Hayward

Full Text Available Salmonella enterica is a zoonotic pathogen of clinical and veterinary significance, with over 2500 serovars. In previous work we compared two serovars displaying host associations inferred from isolation statistics. Here, to validate genome sequence data and to expand on the role of environmental metabolite constitution in host range determination we use a phenotypic microarray approach to assess the ability of these serovars to metabolise ~500 substrates at 25°C with oxygen (aerobic conditions to represent the ex vivo environment and at 37°C with and without oxygen (aerobic/anaerobic conditions to represent the in vivo environment. A total of 26 substrates elicited a significant difference in the rate of metabolism of which only one, D-galactonic acid-g-lactone, could be explained by the presence (S. Mbandaka or the absence (S. Derby of metabolic genes. We find that S. Mbandaka respires more efficiently at ambient temperatures and under aerobic conditions on 18 substrates including: glucosominic acid, saccharic acid, trehalose, fumaric acid, maltotriose, N-acetyl-D-glucosamine, N-acetyl-beta-D-mannosamine, fucose, L-serine and dihydroxy-acetone; whereas S. Derby is more metabolically competent anaerobically at 37°C for dipeptides, glutamine-glutamine, alanine-lysine, asparagine-glutamine and nitrogen sources glycine and nitrite. We conclude that the specific phenotype cannot be reliably predicted from the presence of metabolic genes directly relating to the metabolic pathways under study.

Antimicrobial Drug Resistance of Salmonella enterica Serovar Typhi in Asia and Molecular Mechanism of Reduced Susceptibility to the Fluoroquinolones▿

OpenAIRE

Chau, Tran Thuy; Campbell, James Ian; Galindo, Claudia M.; Van Minh Hoang, Nguyen; Diep, To Song; Nga, Tran Thu Thi; Van Vinh Chau, Nguyen; Tuan, Phung Quoc; Page, Anne Laure; Ochiai, R. Leon; Schultsz, Constance; Wain, John; Bhutta, Zulfiqar A.; Parry, Christopher M.; Bhattacharya, Sujit K.

2007-01-01

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar Typhi strains collected in southern Vietnam, the proportion of multidrug resistance has remained high since 1993 (50% in 2004) and there was a dramatic increase in nalidixic acid resistance between ...

Serotyping, PCR, phage-typing and antibiotic sensitivity testing of Salmonella serovars isolated from urban drinking water supply systems of Nepal

DEFF Research Database (Denmark)

Bhatta, D.R.; Bangtrakulnonth, A.; Tishyadhigama, P.

2007-01-01

Aims: To study the occurrence and diversity of Salmonella serovars in urban water supply systems of Nepal. Methods and Results: Occurrence of Salmonella was detected in 42 out of 300 water samples by enrichment culture technique in selenite F broth followed by plating on Salmonella Shigella agar...... isolates of Salm. Enteritidis indicated the presence of one of the ESBL genes, blaSHV, whereas the genes blaTEM and blaCTX were absent. Conclusions: The microbiological quality of the urban water supply is poor and indicates possibility of fatal outbreaks of enteric fever and related infections in Nepal....... Significance and Impact of the Study: The present study will be useful in water borne disease control and prevention strategy formulation in Nepal and in the global context....

Investigating Salmonella Eko from Various Sources in Nigeria by Whole Genome Sequencing to Identify the Source of Human Infections

DEFF Research Database (Denmark)

Leekitcharoenphon, Pimlapas; Raufu, Ibrahim; Thorup Nielsen, Mette

2016-01-01

Twenty-six Salmonella enterica serovar Eko isolated from various sources in Nigeria were investigated by whole genome sequencing to identify the source of human infections. Diversity among the isolates was observed and camel and cattle were identified as the primary reservoirs and the most likely...

In Vivo-Expressed Proteins of Virulent Leptospira interrogans Serovar Autumnalis N2 Elicit Strong IgM Responses of Value in Conclusive Diagnosis.

Science.gov (United States)

Raja, Veerapandian; Shanmughapriya, Santhanam; Kanagavel, Murugesan; Artiushin, Sergey C; Velineni, Sridhar; Timoney, John F; Natarajaseenivasan, Kalimuthusamy

2016-01-01

Leptospirosis is a serious zoonosis that is underdiagnosed because of limited access to laboratory facilities in Southeast Asia, Central and South America, and Oceania. Timely diagnosis of locally distributed serovars of high virulence is crucial for successful care and outbreak management. Using pooled patient sera, an expression gene library of a virulent Leptospira interrogans serovar Autumnalis strain N2 isolated in South India was screened. The identified genes were characterized, and the purified recombinant proteins were used as antigens in IgM enzyme-linked immunosorbent assay (ELISA) either singly or in combination. Sera (n = 118) from cases of acute leptospirosis along with sera (n = 58) from healthy subjects were tested for reactivity with the identified proteins in an ELISA designed to detect specific IgM responses. We have identified nine immunoreactive proteins, ArgC, RecA, GlpF, FliD, TrmD, RplS, RnhB, Lp28.6, and Lrr44.9, which were found to be highly conserved among pathogenic leptospires. Apparently, the proteins ArgC, RecA, GlpF, FliD, TrmD, and Lrr44.9 are expressed during natural infection of the host and undetectable in in vitro cultures. Among all the recombinant proteins used as antigens in IgM ELISA, ArgC had the highest sensitivity and specificity, 89.8% and 95.5%, respectively, for the conclusive diagnosis of leptospirosis. The use of ArgC and RecA in combination for IgM ELISA increased the sensitivity and specificity to 95.7% and 94.9%, respectively. ArgC and RecA thus elicited specific IgM responses and were therefore effective in laboratory confirmation of Leptospira infection. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Horizontal Transfer of the Salmonella enterica Serovar Infantis Resistance and Virulence Plasmid pESI to the Gut Microbiota of Warm-Blooded Hosts

Directory of Open Access Journals (Sweden)

Gili Aviv

2016-09-01

Full Text Available Salmonella enterica serovar Infantis is one of the prevalent salmonellae worldwide. Recently, we showed that the emergence of S. Infantis in Israel was facilitated by the acquisition of a unique megaplasmid (pESI conferring multidrug resistance and increased virulence phenotypes. Here we elucidate the ecology, transmission properties, and regulation of pESI. We show that despite its large size (~280 kb, pESI does not impose a significant metabolic burden in vitro and that it has been recently fixed in the domestic S. Infantis population. pESI conjugation and the transcription of its pilus (pil genes are inhibited at the ambient temperature (27°C and by ≥1% bile but increased under temperatures of 37 to 41°C, oxidative stress, moderate osmolarity, and the microaerobic conditions characterizing the intestinal environment of warm-blooded animals. The pESI-encoded protein TraB and the oxygen homeostasis regulator Fnr were identified as transcriptional regulators of pESI conjugation. Using the mouse model, we show that following S. Infantis infection, pESI can be horizontally transferred to the gut microbiota, including to commensal Escherichia coli strains. Possible transfer, but not persistence, of pESI was also observed into Gram-positive mouse microbiota species, especially Lactobacillus reuteri. Moreover, pESI was demonstrated to further disseminate from gut microbiota to S. enterica serovar Typhimurium, in the context of gastrointestinal infection. These findings exhibit the ability of a selfish clinically relevant megaplasmid to distribute to and from the microbiota and suggest an overlooked role of the microbiota as a reservoir of mobile genetic elements and intermediator in the spread of resistance and virulence genes between commensals and pathogenic bacteria.

Female partner preferences enhance offspring ability to survive an infection.

Science.gov (United States)

Raveh, Shirley; Sutalo, Sanja; Thonhauser, Kerstin E; Thoß, Michaela; Hettyey, Attila; Winkelser, Friederike; Penn, Dustin J

2014-01-23

It is often suggested that mate choice enhances offspring immune resistance to infectious diseases. To test this hypothesis, we conducted a study with wild-derived house mice (Mus musculus musculus) in which females were experimentally mated either with their preferred or non-preferred male, and their offspring were infected with a mouse pathogen, Salmonella enterica (serovar Typhimurium). We found that offspring sired by preferred males were significantly more likely to survive the experimental infection compared to those sired by non-preferred males. We found no significant differences in the pathogen clearance or infection dynamics between the infected mice, suggesting that offspring from preferred males were better able to cope with infection and had improved tolerance rather than immune resistance. Our results provide the first direct experimental evidence within a single study that partner preferences enhance offspring resistance to infectious diseases.

Identification of Salmonella serovars isolated from live molluscan shellfish and their significance in the marine environment.

Science.gov (United States)

Martinez-Urtaza, Jaime; Saco, Montserrat; Hernandez-Cordova, Gustavo; Lozano, Antonio; Garcia-Martin, Oscar; Espinosa, Joaquin

2003-02-01

A study on the presence of Salmonella spp. in live molluscs was performed, which included a description of the different serovars isolated and their relationship to the marine environment. A total of 2,980 samples of shellfish from Galicia (N.W. Spain) were tested for the presence of Salmonella spp. between September 1998 and August 2001. The overall incidence of Salmonella was 1.8% and showed a slight rise during the 3 years of the study. Mussels and oysters presented a higher incidence than clams and cockles, possibly because of their distinct growing habitat. A seasonal pattern was noted for the isolation of Salmonella spp.: 54% of the isolations were detected from September to November. That nearly 67% of the total Salmonella was isolated from shellfish with fecal coliform levels fecal coliforms do not necessarily indicate the absence of Salmonella. A total of nine serovars were found in the 54 Salmonella isolated. Salmonella Senftenberg was the most frequent (50%), followed by Salmonella Typhimurium (18%) and Salmonella Agona (17%). Salmonella Senftenberg was detected frequently during the year, whereas the remaining serovars were detected only on occasional contamination events.

Persistence of a Salmonella enterica serovar typhimurium DT12 clone in a piggery and in agricultural soil amended with Salmonella-contaminated slurry

DEFF Research Database (Denmark)

Baloda, Suraj B.; Christensen, Lise; Trajcevska, Silvija

2001-01-01

Prevalence of Salmonella enterica on a Danish pig farm presenting recurrent infections was investigated. A comparison of the pulsed-held gel electrophoresis patterns of fecal isolates from piggeries, waste slurry, and agricultural soil amended with Salmonella-contaminated animal waste (slurry......) and subclinical isolates from the same farm (collected in 1996 and later) showed identical patterns, indicating long-term persistence of the Salmonella enterica serovar Typhimurium DT12 clone in the herd environment. Furthermore, when Salmonella-contaminated slurry was disposed of on the agricultural soil (a...... common waste disposal practice), the pathogen was isolated up to 14 days after the spread, indicating potentially high risks of transmission of the pathogen in the environment, animals, and humans....

SEROPREVALENCE OF NINE LEPTOSPIRA INTERROGANS SEROVARS IN WILD CARNIVORES, UNGULATES, AND PRIMATES FROM A ZOO POPULATION IN A METROPOLITAN REGION OF CHILE.

Science.gov (United States)

Moreno-Beas, Eduardo; Abalos, Pedro; Hidalgo-Hermoso, Ezequiel

2015-12-01

Serum samples from 130 individuals representing 42 species of carnivores, ungulates, and primates from a population of captive mammals in Metropolitan Region in Chile were tested for antibodies against nine serovars of Leptospira interrogans using the microscopic agglutination test. Ten percent of the animals were seropositive to one or more serovars. Seroprevalence was significantly higher in ungulates (20.4%) compared to carnivores (3.8%) and primates (3.4%). There were no significant differences in seroprevalence among sex and age ranges. The most frequent serovar detected was Autumnalis, present in 53.4% of antibody-positive animals. Most positive animals had titers of ≤1 : 200, except for a maned wolf ( Chrysocyon brachyurus ) with titers of 1 : 400 against serovar Hardjo. To the authors' knowledge, this is the first report of Leptospira exposure detected in native endangered pudu ( Pudu puda ) and the first confirmation of exposure to L. interrogans in captive wild mammals in Chile. Leptospirosis should be considered as a differential diagnosis in future disease presentation for hepatitis or abortions in captive mammals in Chile.

Dam methylation participates in the regulation of PmrA/PmrB and RcsC/RcsD/RcsB two component regulatory systems in Salmonella enterica serovar Enteritidis.

Directory of Open Access Journals (Sweden)

Sebastián Hernán Sarnacki

Full Text Available The absence of Dam in Salmonella enterica serovar Enteritidis causes a defect in lipopolysaccharide (LPS pattern associated to a reduced expression of wzz gene. Wzz is the chain length regulator of the LPS O-antigen. Here we investigated whether Dam regulates wzz gene expression through its two known regulators, PmrA and RcsB. Thus, the expression of rcsB and pmrA was monitored by quantitative real-time RT-PCR and Western blotting using fusions with 3×FLAG tag in wild type (wt and dam strains of S. Enteritidis. Dam regulated the expression of both rcsB and pmrA genes; nevertheless, the defect in LPS pattern was only related to a diminished expression of RcsB. Interestingly, regulation of wzz in serovar Enteritidis differed from that reported earlier for serovar Typhimurium; RcsB induces wzz expression in both serovars, whereas PmrA induces wzz in S. Typhimurium but represses it in serovar Enteritidis. Moreover, we found that in S. Enteritidis there is an interaction between both wzz regulators: RcsB stimulates the expression of pmrA and PmrA represses the expression of rcsB. Our results would be an example of differential regulation of orthologous genes expression, providing differences in phenotypic traits between closely related bacterial serovars.

Multidrug-resistant opportunistic pathogens challenging veterinary infection control.

Science.gov (United States)

Walther, Birgit; Tedin, Karsten; Lübke-Becker, Antina

2017-02-01

Although the problems associated with healthcare-associated infections (HAI) and the emergence of zoonotic and multidrug-resistant pathogens in companion animal (dogs, cats and horses) medicine have been well-known for decades, current progress with respect to practical implementation of infection control programs in veterinary clinics has been limited. Clinical outbreak events reported for methicillin-resistant Staphylooccus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP), extended spectrum beta-lactamase (ESBL)-producing Escherichia coli and multidrug-resistant (MDR) Salmonella Serovars indicate the necessity of infection control strategies for protecting animal patients at risk as well as veterinary personnel. The close bond between humans and their companion animals provides opportunities for exchange of microorganisms, including MDR pathogens. This particular aspect of the "One Health" idea requires more representative surveillance efforts and infection control strategies with respect to animal-species specific characters. Copyright © 2016 Elsevier B.V. All rights reserved.

A defective mutant of Salmonella enterica Serovar Gallinarum in cobalamin biosynthesis is avirulent in chickens Mutante de Salmonella enterica serovar Gallinarum duplo defectivo na biossíntese de cobalamina é avirulento para aves

Directory of Open Access Journals (Sweden)

Jacqueline Boldrin de Paiva

2009-09-01

Full Text Available Salmonella enterica serovar Gallinarum (SG is a fowl typhoid agent in chickens and is a severe disease with worldwide economic impact as its mortality may reach up to 80%. It is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. The survival mechanisms are not considered to be virulent mechanisms but are essential for the life of the bacterium. Mutants of Salmonella Gallinarum containing defective genes, related to cobalamin biosynthesis and which Salmonella spp. has to be produced to survive when it is in an anaerobic environment, were produced in this study. Salmonella Gallinarum is an intracellular parasite. Therefore, this study could provide information about whether vitamin B12 biosynthesis might be essential to its survival in the host. The results showed that the singular deletion in cbiA or cobS genes did not interfere in the life of Salmonella Gallinarum in the host, perhaps because single deletion is not enough to impede vitamin B12 biosynthesis. It was noticed that diluted SG mutants with single deletion produced higher mortality than the wild strain of SG. When double mutation was carried out, the Salmonella Gallinarum mutant was unable to provoke mortality in susceptible chickens. This work showed that B12 biosynthesis is a very important step in the metabolism of Salmonella Gallinarum during the infection of the chickens. Further research on bacterium physiology should be carried out to elucidate the events described in this research and to assess the mutant as a vaccine strain.Salmonella enterica serovar Gallinarum (SG é o agente do tifo aviário, doença severa que provoca mortalidade em até 80% do plantel de aves. SG encontra-se entre os poucos sorotipos de Salmonella que são agentes etiológicos de enfermidade específica, à semelhança de Salmonella Typhi em seres humanos podendo, portanto, servir

Differential interactions of virulent and non-virulent H. parasuis strains with naïve or swine influenza virus pre-infected dendritic cells.

Science.gov (United States)

Mussá, Tufária; Rodríguez-Cariño, Carolina; Sánchez-Chardi, Alejandro; Baratelli, Massimiliano; Costa-Hurtado, Mar; Fraile, Lorenzo; Domínguez, Javier; Aragon, Virginia; Montoya, María

2012-11-16

Pigs possess a microbiota in the upper respiratory tract that includes Haemophilus parasuis. Pigs are also considered the reservoir of influenza viruses and infection with this virus commonly results in increased impact of bacterial infections, including those by H. parasuis. However, the mechanisms involved in host innate responses towards H. parasuis and their implications in a co-infection with influenza virus are unknown. Therefore, the ability of a non-virulent H. parasuis serovar 3 (SW114) and a virulent serovar 5 (Nagasaki) strains to interact with porcine bone marrow dendritic cells (poBMDC) and their modulation in a co-infection with swine influenza virus (SwIV) H3N2 was examined. At 1 hour post infection (hpi), SW114 interaction with poBMDC was higher than that of Nagasaki, while at 8 hpi both strains showed similar levels of interaction. The co-infection with H3N2 SwIV and either SW114 or Nagasaki induced higher levels of IL-1β, TNF-α, IL-6, IL-12 and IL-10 compared to mock or H3N2 SwIV infection alone. Moreover, IL-12 and IFN-α secretion differentially increased in cells co-infected with H3N2 SwIV and Nagasaki. These results pave the way for understanding the differences in the interaction of non-virulent and virulent strains of H. parasuis with the swine immune system and their modulation in a viral co-infection.

Role of Environmental Factors in Shaping Spatial Distribution of Salmonella enterica Serovar Typhi, Fiji.

Science.gov (United States)

de Alwis, Ruklanthi; Watson, Conall; Nikolay, Birgit; Lowry, John H; Thieu, Nga Tran Vu; Van, Tan Trinh; Ngoc, Dung Tran Thi; Rawalai, Kitione; Taufa, Mere; Coriakula, Jerimaia; Lau, Colleen L; Nilles, Eric J; Edmunds, W John; Kama, Mike; Baker, Stephen; Cano, Jorge

2018-02-01

Fiji recently experienced a sharp increase in reported typhoid fever cases. To investigate geographic distribution and environmental risk factors associated with Salmonella enterica serovar Typhi infection, we conducted a cross-sectional cluster survey with associated serologic testing for Vi capsular antigen-specific antibodies (a marker for exposure to Salmonella Typhi in Fiji in 2013. Hotspots with high seroprevalence of Vi-specific antibodies were identified in northeastern mainland Fiji. Risk for Vi seropositivity increased with increased annual rainfall (odds ratio [OR] 1.26/quintile increase, 95% CI 1.12-1.42), and decreased with increased distance from major rivers and creeks (OR 0.89/km increase, 95% CI 0.80-0.99) and distance to modeled flood-risk areas (OR 0.80/quintile increase, 95% CI 0.69-0.92) after being adjusted for age, typhoid fever vaccination, and home toilet type. Risk for exposure to Salmonella Typhi and its spatial distribution in Fiji are driven by environmental factors. Our findings can directly affect typhoid fever control efforts in Fiji.

JcTI-I: a novel trypsin inhibitor from Jatropha curcas seed cake with potential for bacterial infection treatment.

Science.gov (United States)

Costa, Helen P S; Oliveira, Jose T A; Sousa, Daniele O B; Morais, Janne K S; Moreno, Frederico B; Monteiro-Moreira, Ana Cristina O; Viegas, Ricardo A; Vasconcelos, Ilka M

2014-01-01

Jatropha curcas seed cake is a low-value by-product resulting from biodiesel production. The seed cake is highly toxic, but it has great potential for biotechnology applications as it is a repository of biomolecules that could be important in agriculture, medicine, and industry. To explore this potential, a novel trypsin inhibitor called JcTI-I was purified by fractionation of the crude extract with trichloroacetic acid (2.5%, v/v) followed by affinity chromatography (Trypsin-Sepharose 4B) and molecular exclusion (Sephacryl S-200). Non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration showed that JcTI-I has approximately 20.0~kDa. Mass spectrometry analysis revealed that the intact molecular mass of JcTI-I is 10.252~kDa. Moreover, JcTI-I is a glycoprotein with 6.4% (m/m) carbohydrates, pI of 6.6, N-terminal sequence similarity around 60% to plant albumins and high stability to heat, pH, and salinity. JcTI-I presented antibacterial activity against the human pathogenic bacteria Salmonella enterica subspecies enterica serovar choleraesuis and Staphylococcus aureus, with minimum inhibitory concentration less than 5~μg/mL. Furthermore, JcTI-I did have inhibitory activity against the serine proteases from the tested bacteria. Otherwise, no hemolytic activity of human erythrocytes and signs of acute toxicity to mice were observed for JcTI-I. The results demonstrate the benefits of J. curcas seed cake as a source of trypsin inhibitor with potential for biotechnological application as a new antimicrobial agent against human pathogenic bacteria.

JcTI-I, a novel trypsin inhibitor from Jatropha curcas seed cake with potential for bacterial infection treatment

Directory of Open Access Journals (Sweden)

Helen Paula S Costa

2014-01-01

Full Text Available Jatropha curcas seed cake is a low-value by-product resulting from biodiesel production. The seed cake is highly toxic, but it has great potential for biotechnology applications as it is a repository of biomolecules that could be important in agriculture, medicine and industry. To explore this potential, a novel trypsin inhibitor called JcTI-I was purified by fractionation of the crude extract with trichloroacetic acid (2.5%, v/v followed by affinity chromatography (Trypsin-Sepharose 4B and molecular exclusion (Sephacryl S-200. Non-reducing SDS-PAGE and gel filtration showed that JcTI-I has approximately 20.0 kDa. Mass spectrometry analysis revealed that the intact molecular mass of JcTI-I is 10.252 kDa. Moreover, JcTI-I is a glycoprotein with 6.4% (m/m carbohydrates, pI of 6.6, N-terminal sequence similarity around 60% to plant albumins and high stability to heat, pH and salinity. JcTI-I presented antibacterial activity against the human pathogenic bacteria Salmonella enterica subspecies enterica serovar choleraesuis and Staphylococcus aureus, with minimum inhibitory concentration (MIC less than 5 µg/mL. Furthermore, JcTI-I did have inhibitory activity against the serine proteases from the tested bacteria. Otherwise, no hemolytic activity of human erythrocytes and signs of acute toxicity to mice were observed for JcTI-I. The results demonstrate the benefits of J. curcas seed cake as a source of trypsin inhibitor with potential for biotechnological application as a new antimicrobial agent against human pathogenic bacteria.

Molecular identification of common Salmonella serovars using multiplex DNA sensor-based suspension array.

Science.gov (United States)

Aydin, Muhsin; Carter-Conger, Jacqueline; Gao, Ning; Gilmore, David F; Ricke, Steven C; Ahn, Soohyoun

2018-04-01

Salmonella is one of major foodborne pathogens and the leading cause of foodborne illness-related hospitalizations and deaths. It is critical to develop a sensitive and rapid detection assay that can identify Salmonella to ensure food safety. In this study, a DNA sensor-based suspension array system of high multiplexing ability was developed to identify eight Salmonella serovars commonly associated with foodborne outbreaks to the serotype level. Each DNA sensor was prepared by activating pre-encoded microspheres with oligonucleotide probes that are targeting virulence genes and serovar-specific regions. The mixture of 12 different types of DNA sensors were loaded into a 96-well microplate and used as a 12-plex DNA sensor array platform. DNA isolated from Salmonella was amplified by multiplex polymerase chain reaction (mPCR), and the presence of Salmonella was determined by reading fluorescent signals from hybridization between probes on DNA sensors and fluorescently labeled target DNA using the Bio-Plex® system. The developed multiplex array was able to detect synthetic DNA at the concentration as low as 100 fM and various Salmonella serovars as low as 100 CFU/mL within 1 h post-PCR. Sensitivity of this assay was further improved to 1 CFU/mL with 6-h enrichment. The array system also correctly and specifically identified serotype of tested Salmonella strains without any cross-reactivity with other common foodborne pathogens. Our results indicate the developed DNA sensor suspension array can be a rapid and reliable high-throughput method for simultaneous detection and molecular identification of common Salmonella serotypes.

Relationship of Triamine-Biocide Tolerance of Salmonella enterica Serovar Senftenberg to Antimicrobial Susceptibility, Serum Resistance and Outer Membrane Proteins.

Science.gov (United States)

Futoma-Kołoch, Bożena; Dudek, Bartłomiej; Kapczyńska, Katarzyna; Krzyżewska, Eva; Wańczyk, Martyna; Korzekwa, Kamila; Rybka, Jacek; Klausa, Elżbieta; Bugla-Płoskońska, Gabriela

2017-07-11

A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg ( S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins' patterns. The strategy of bacterial membrane proteins' analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species.

Diversity and antimicrobial susceptibility of Salmonella enterica serovars isolated from pig farms in Ibadan, Nigeria

DEFF Research Database (Denmark)

Fashae, Kayode; Hendriksen, Rene S.

2014-01-01

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...... 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....... 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....

Coordinated Regulation of Virulence during Systemic Infection of Salmonella enterica serovar Typhimurium

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hyunjin; McDermott, Jason E.; Porwollik, Steffen; Mcclelland, Michael; Heffron, Fred

2009-02-20

Salmonella must respond to a myriad of environmental cues during infection of a mouse and express specific subsets of genes in a temporal and spatial manner to subvert the host defense mechanisms but these regulatory pathways are poorly established. To unravel how micro-environmental signals are processed and integrated into coordinated action, we constructed in-frame non-polar deletions of 84 regulators inferred to play a role in Salmonella typhimurium virulence and tested them in three virulence assays (intraperitoneal (i.p.), and intragastric (i.g.) infection in BALB/c mice, and persistence in SvJ129 mice). Overall 36 regulators were identified that were less virulent in at least one assay, and of those, 15 regulators were required for systemic mouse infection in an acute infection model. As a first step towards understanding the interplay between a pathogen and its host from a systems biology standpoint we focused on these 15 genes. Transcriptional profiles were obtained for each of these 15 regulators from strains grown under four different environmental conditions. These results as well as publicly available transcriptional profiles were analyzed using both network inference and cluster analysis algorithms. The analysis predicts a regulatory network in which all 15 regulators control a specific set of genes necessary for Salmonella to cause systemic infection. We tested the regulatory model by expressing a subset of the regulators in trans and monitoring transcription of 7 known virulence factors located within Salmonella pathogenicity island 2 (SPI-2). These experiments validated the regulatory model and showed that, for these 7 genes, the response regulator SsrB and the marR type regulator SlyA co-regulate in a regulatory cascade by integrating multiple signals.

ANTIBACTERIAL ACTIVITY OF SILVER NANOPARTICLES: SENSITIVITY OF DIFFERENT SALMONELLA SEROVARS

Directory of Open Access Journals (Sweden)

Carmen eLosasso

2014-05-01

Full Text Available Salmonella spp. is one of the main causes of foodborne illnesses in humans worldwide. Consequently, great interest exists in reducing its impact on human health by lowering its prevalence in the food chain. Antimicrobial formulations in the form of nanoparticles exert bactericidal action due to their enhanced reactivity resultant from their high surface/volume ratio. Silver nanoparticles (AgNPs are known to be highly toxic to Gram-negative and Gram-positive microorganisms, including multidrug resistant bacteria. However, few data concerning their success against different Salmonella serovars are available. Aims of the present study were to test the antimicrobial effectiveness of AgNPs, against Salmonella Enteritidis, Hadar and Senftenberg, and to investigate the causes of their different survival abilities from a molecular point of view.Results showed an immediate, time-limited and serovar-dependent reduction of bacterial viability. In the case of S. Senftenberg, the reduction in numbers was observed for up to 4 h of incubation in the presence of 200 mg/L of AgNPs; on the contrary, S. Enteritidis and S. Hadar resulted to be inhibited for up to 48 h. RT-PCR experiments demonstrated the constitutive expression of the plasmidic silver resistance determinant (SilB by S. Senftenberg, thus suggesting the importance of a cautious use of AgNPs.

Multiple‐locus variable‐number tandem repeat analysis of Salmonella enterica subsp. enterica serovar Dublin

DEFF Research Database (Denmark)

Kjeldsen, M. K.; Torpdahl, M.; Campos, J.

2014-01-01

Salmonella serovar Dublin causes disease in cattle and leads to considerable production losses. In humans, severe invasive disease and high mortality rates are reported. The presently available typing methods provide insufficient discrimination within Salm. Dublin for epidemiological investigatio...

Emerging Infectious Disease Implications of Invasive Mammalian Species: The Greater White-Toothed Shrew (Crocidura russula) Is Associated With a Novel Serovar of Pathogenic Leptospira in Ireland.

Science.gov (United States)

Nally, Jarlath E; Arent, Zbigniew; Bayles, Darrell O; Hornsby, Richard L; Gilmore, Colm; Regan, Siobhan; McDevitt, Allan D; Yearsley, Jon; Fanning, Séamus; McMahon, Barry J

2016-12-01

The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira.

The plasmid-encoded Ipf and Klf fimbriae display different expression and varying roles in the virulence of Salmonella enterica serovar Infantis in mouse vs. avian hosts.

Directory of Open Access Journals (Sweden)

Gili Aviv

2017-08-01

Full Text Available Salmonella enterica serovar Infantis is one of the prevalent Salmonella serovars worldwide. Different emergent clones of S. Infantis were shown to acquire the pESI virulence-resistance megaplasmid affecting its ecology and pathogenicity. Here, we studied two previously uncharacterized pESI-encoded chaperone-usher fimbriae, named Ipf and Klf. While Ipf homologs are rare and were found only in S. enterica subspecies diarizonae and subspecies VII, Klf is related to the known K88-Fae fimbria and klf clusters were identified in seven S. enterica subspecies I serovars, harboring interchanging alleles of the fimbria major subunit, KlfG. Regulation studies showed that the klf genes expression is negatively and positively controlled by the pESI-encoded regulators KlfL and KlfB, respectively, and are activated by the ancestral leucine-responsive regulator (Lrp. ipf genes are negatively regulated by Fur and activated by OmpR. Furthermore, induced expression of both klf and ipf clusters occurs under microaerobic conditions and at 41°C compared to 37°C, in-vitro. Consistent with these results, we demonstrate higher expression of ipf and klf in chicks compared to mice, characterized by physiological temperature of 41.2°C and 37°C, respectively. Interestingly, while Klf was dispensable for S. Infantis colonization in the mouse, Ipf was required for maximal colonization in the murine ileum. In contrast to these phenotypes in mice, both Klf and Ipf contributed to a restrained infection in chicks, where the absence of these fimbriae has led to moderately higher bacterial burden in the avian host. Taken together, these data suggest that physiological differences between host species, such as the body temperature, can confer differences in fimbriome expression, affecting Salmonella colonization and other host-pathogen interplays.

Plasmid Negative Regulation of CPAF Expression Is Pgp4 Independent and Restricted to Invasive Chlamydia trachomatis Biovars

Directory of Open Access Journals (Sweden)

Michael John Patton

2018-01-01

Full Text Available Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes blinding trachoma and sexually transmitted disease. C. trachomatis isolates are classified into 2 biovars—lymphogranuloma venereum (LGV and trachoma—which are distinguished biologically by their natural host cell infection tropism. LGV biovars infect macrophages and are invasive, whereas trachoma biovars infect oculo-urogenital epithelial cells and are noninvasive. The C. trachomatis plasmid is an important virulence factor in the pathogenesis of these infections. Central to its pathogenic role is the transcriptional regulatory function of the plasmid protein Pgp4, which regulates the expression of plasmid and chromosomal virulence genes. As many gene regulatory functions are post-transcriptional, we employed a comparative proteomic study of cells infected with plasmid-cured C. trachomatis serovars A and D (trachoma biovar, a L2 serovar (LGV biovar, and the L2 serovar transformed with a plasmid containing a nonsense mutation in pgp4 to more completely elucidate the effects of the plasmid on chlamydial infection biology. Our results show that the Pgp4-dependent elevations in the levels of Pgp3 and a conserved core set of chromosomally encoded proteins are remarkably similar for serovars within both C. trachomatis biovars. Conversely, we found a plasmid-dependent, Pgp4-independent, negative regulation in the expression of the chlamydial protease-like activity factor (CPAF for the L2 serovar but not the A and D serovars. The molecular mechanism of plasmid-dependent negative regulation of CPAF expression in the LGV serovar is not understood but is likely important to understanding its macrophage infection tropism and invasive infection nature.

Molecular Characterization and Antimicrobial Susceptibility of Salmonella Isolates from Infections in Humans in Henan Province, China

DEFF Research Database (Denmark)

Xia, S.L.; Hendriksen, Rene S.; Xie, Z.Q.

2009-01-01

We characterized 208 human Salmonella isolates from 2006 to 2007 and 27 human Salmonella enterica serovar Typhimurium isolates from 1987 to 1993 from Henan Province, China, by serotyping, by antimicrobial susceptibility testing, and, for the most common serovars, by pulsed-field gel electrophoresis...... (PFGE). The most common serovars among the 2006-2007 isolates were S. enterica serovar Typhimurium (27%), S. enterica serovar Enteritidis (17%), S. enterica serovar Derby (10%), S. enterica serovar Indiana (6%), and S. enterica serovar Litchfield (6%). A high percentage of the isolates were multiple-drug...

Influence of Temperature and Predation on Survival of Salmonella enterica Serovar Typhimurium and Expression of invA in Soil and Manure-Amended Soil▿

Science.gov (United States)

García, R.; Bælum, J.; Fredslund, L.; Santorum, P.; Jacobsen, C. S.

2010-01-01

The effects of three temperatures (5, 15, and 25°C) on the survival of Salmonella enterica serovar Typhimurium in topsoil were investigated in small microcosms by three different techniques: plate counting, invA gene quantification, and invA mRNA quantification. Differences in survival were related to the effect of protozoan predation. Tetracycline-resistant Salmonella serovar Typhimurium was inoculated into soil and manure-amended soil at 1.5 × 108 cells g soil−1. Population densities were determined by plate counting and by molecular methods and monitored for 42 days. Simultaneous extraction of RNA and DNA, followed by quantitative PCR, was used to investigate invA gene levels and expression. Analysis by these three techniques showed that Salmonella serovar Typhimurium survived better at 5°C. Comparing DNA and CFU levels, significantly higher values were determined by DNA-based techniques. invA mRNA levels showed a fast decrease in activity, with no detectable mRNA after an incubation period of less than 4 days in any of the soil scenarios. A negative correlation was found between Salmonella serovar Typhimurium CFU levels and protozoan most probable numbers, and we propose the role of the predator-prey interaction as a factor to explain the die-off of the introduced strain by both culture- and DNA quantification-based methods. The results indicate that temperature, manure, and protozoan predation are important factors influencing the survival of Salmonella serovar Typhimurium in soil. PMID:20562283

Alternate phase variation in expression of two major surface membrane proteins (MBA and UU376) of Ureaplasma parvum serovar 3.

Science.gov (United States)

Zimmerman, Carl-Ulrich R; Stiedl, Thomas; Rosengarten, Renate; Spergser, Joachim

2009-03-01

Ureaplasma urealyticum and Ureaplasma parvum are commensals and pathogens of the human urogenital tract and of newborn infants. There are four distinct U. parvum serovars and 10 distinct U. urealyticum serovars. Both species possess a distinct immunodominant variable surface protein, the multiple banded antigen (MBA), which shows size variability among isolates as a result of changes in the number of C-terminal repeating units. Adjacent to the MBA gene (UU375) lies UU376, which was annotated as 'Ureaplasma-specific conserved hypothetical gene'. In four different strains of U. parvum serovar 3, we demonstrated expression of UU376 by Western blot analysis and phase variation between UU376, here designated Upvmp376 (Ureaplasma phase-variable membrane protein 376), and MBA after application of selective pressure with hyperimmune antisera directed against either protein. By Southern blot analysis, we found that the switch between MBA and Upvmp376 expression is associated with a DNA inversion event in which the nonrepetitive region of the MBA gene and its putative promoter region are opposed to either the repetitive region of MBA or UU376. We propose that in U. parvum serovar 3, and presumably in all U. parvum and U. urealyticum, an inversion event at specific sites effects an alternate ON/OFF switching of the genes UU375 and UU376.

Evidence of metabolic switching and implications for food safety from the phenome(s) of Salmonella enterica serovar Typhimurium DT104 cultured at selected points across the pork production food chain.

Science.gov (United States)

Martins, Marta; McCusker, Matthew P; McCabe, Evonne M; O'Leary, Denis; Duffy, Geraldine; Fanning, Séamus

2013-09-01

Salmonella enterica serovar Typhimurium DT104 is a recognized food-borne pathogen that displays a multidrug-resistant phenotype and that is associated with systemic infections. At one extreme of the food chain, this bacterium can infect humans, limiting the treatment options available and thereby contributing to increased morbidity and mortality. Although the antibiotic resistance profile is well defined, little is known about other phenotypes that may be expressed by this pathogen at key points across the pork production food chain. In this study, 172 Salmonella enterica serovar Typhimurium DT104/DT104b isolated from an extensive "farm-to-fork" surveillance study, focusing on the pork food chain, were characterized in detail. Isolates were cultured from environmental, processing, retail, and clinical sources, and the study focused on phenotypes that may have contributed to persistence/survival in these different niches. Molecular subtypes, along with antibiotic resistance profiles, tolerance to biocides, motility, and biofilm formation, were determined. As a basis for human infection, acid survival and the ability to utilize a range of energy sources and to adhere to and/or invade Caco-2 cells were also studied. Comparative alterations to biocide tolerance were observed in isolates from retail. l-Tartaric acid and d-mannose-1-phosphate induced the formation of biofilms in a preselected subset of strains, independent of their origin. All clinical isolates were motile and demonstrated an enhanced ability to survive in acidic conditions. Our data report on a diverse phenotype, expressed by S. Typhimurium isolates cultured from the pork production food chain. Extending our understanding of the means by which this pathogen adapts to environmental niches along the "farm-to-fork" continuum will facilitate the protection of vulnerable consumers through targeted improvements in food safety measures.

Lymphogranuloma venereum in an Italian MSM: concurrent pharyngeal and rectal infection.

Science.gov (United States)

Foschi, Claudio; Filippini, Andrea; D'Antuono, Antonietta; Compri, Monica; Macca, Francesca; Banzola, Nicoletta; Marangoni, Antonella

2014-07-01

An Italian HIV-positive man having sex with men (MSM) attended the STIs Outpatients Clinic of Sant'Orsola Hospital in Bologna complaining of anal pain and constipation. According to patient's sexual history and repertoires, NAAT testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) was performed. Pharyngeal and anal swabs resulted positive for CT DNA detection and the following molecular genotyping identified a L2 serovar, coming to the final diagnosis of pharyngeal and rectal lymphogranuloma venereum (LGV) infection. After an antibiotic therapy with doxycycline 100 mg twice a day for 3 weeks, the patient completely recovered and the test of cure was negative for LGV infection.

Salmonella enterica serovars Enteritidis infection alters the indigenous microbiota diversity in young layer chicks

Directory of Open Access Journals (Sweden)

Khin Khine Zar Mon

2015-11-01

Full Text Available Avian gastrointestinal tracts are highly populated with a diverse array of microorganisms that share a symbiotic relationship with their hosts and contribute to the overall health and disease state of the intestinal tract. The microbiome of the young chick is easily prone to alteration in its composition by both exogenous and endogenous factors especially during the early post-hatch period. The genetic background of the host and exposure to pathogens can impact the diversity of the microbial profile that consequently contributes to the disease progression in the host. The objective of this study was to profile the composition and structure of the gut microbiota in young chickens from two genetically distinct highly inbred lines. Furthermore, the effect of the Salmonella Enteritidis infection on altering the composition makeup of the chicken microbiome was evaluated through the 16S rRNA gene sequencing analysis. One-day-old layer chicks were challenged with S. Enteritidis and the host cecal microbiota profile as well as the degree of susceptibility to Salmonella infection was examined at 2 and 7 days post-infection. Our result indicated that host genotype had a limited effect on resistance to S. Enteritidis infection. Alpha diversity, beta diversity, and overall microbiota composition were analyzed for four factors: host genotype, age, treatment, and post-infection time-points. S. Enteritidis infection in young chicks was found to significantly reduce the overall diversity of the microbiota population with expansion of Enterobacteriaceae family. These changes indicated that Salmonella colonization in the gastrointestinal tract of the chickens has a direct effect on altering the natural development of the gastrointestinal microbiota. The impact of S. Enteritidis infection on microbial communities was also more substantial in late stage of infection. Significant inverse correlation between Enterobacteriaceae and Lachnospiraceae family in both non-infected

Combination of PCR targeting the VD2 of omp1 and reverse line blot analysis for typing of urogenital Chlamydia trachomatis serovars in cervical scrape specimens.

NARCIS (Netherlands)

Molano, M; Meijer, C.J.L.M.; Morre, S.A.; Pol, R; Brule, van den AJ

2004-01-01

50% contained both serovars D and E. The nested VD2 PCR-RLB developed is a simple, fast, and specific method for the identification of individual urogenital C. trachomatis serovars previously detected by using plasmid PCR. Moreover, it is an appropriate method for studying multiple C. trachomatis

In Vitro Development of Ciprofloxacin Resistance of Salmonella enterica Serovars Typhimurium, Enteritidis, and Indiana Isolates from Food Animals.

Science.gov (United States)

Zhang, Wen-Hui; Zhang, Chuan-Zhen; Liu, Zhi-Jie; Gu, Xi-Xi; Li, Wan; Yang, Ling; Liu, Ya-Hong; Zeng, Zhen-Ling; Jiang, Hong-Xia

2017-09-01

Difference in the development of resistance may be associated with the epidemiological spread and drug resistance of different Salmonella enterica serovar strains. In the present study, three susceptible S. enterica serovars, Typhimurium (ST), Enteritidis (SE), and Indiana (SI) strains, were subjected to stepwise selection with increasing ciprofloxacin concentrations. The results indicated that the mutation frequencies of the SI group were 10 1 -10 4 higher and developed resistance to ciprofloxacin more rapidly compared with the ST and SE groups. Ciprofloxacin accumulation in the SI strain was also higher than the other two strains in the presence of an efflux pump inhibitor. The development of ciprofloxacin resistance was quite different among the three serovar strains. In SI, increasing AcrAB-TolC efflux pump expression and single or double mutations in gyrA with or without a single parC mutation (T57S) were found in the development of ciprofloxacin resistance. In SE, an increase in the AcrAB-TolC efflux pump regulatory gene ramA gradually decreased as resistant bacteria developed; then resistance resulted from gyrA D87G and gyrB E466D mutations and/or in other active efflux pumps besides AcrAB-TolC. For ST, ramA expression increased rapidly along with gyrA D87 N and/or gyrB S464F mutations. In conclusion, persistent use of ciprofloxacin may aggravate the resistance of different S. enterica serovars and prudent use of the fluoroquinolones is needed. The quicker resistance and higher mutation frequency of the SI isolates present a potential public health threat.

pH-, Lactic acid-, and non-lactic acid-dependent activities of probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium.

Science.gov (United States)

Fayol-Messaoudi, Domitille; Berger, Cédric N; Coconnier-Polter, Marie-Hélène; Liévin-Le Moal, Vanessa; Servin, Alain L

2005-10-01

The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect.

Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

Directory of Open Access Journals (Sweden)

Lilian Terezinha de Queiroz Leite

1996-10-01

Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.

Respiratory hydrogen use by Salmonella enterica serovar Typhimurium is essential for virulence.

Science.gov (United States)

Maier, R J; Olczak, A; Maier, S; Soni, S; Gunn, J

2004-11-01

Based on available annotated gene sequence information, the enteric pathogen salmonella, like other enteric bacteria, contains three putative membrane-associated H2-using hydrogenase enzymes. These enzymes split molecular H2, releasing low-potential electrons that are used to reduce quinone or heme-containing components of the respiratory chain. Here we show that each of the three distinct membrane-associated hydrogenases of Salmonella enterica serovar Typhimurium is coupled to a respiratory pathway that uses oxygen as the terminal electron acceptor. Cells grown in a blood-based medium expressed four times the amount of hydrogenase (H2 oxidation) activity that cells grown on Luria Bertani medium did. Cells suspended in phosphate-buffered saline consumed 2 mol of H2 per mol of O2 used in the H2-O2 respiratory pathway, and the activity was inhibited by the respiration inhibitor cyanide. Molecular hydrogen levels averaging over 40 microM were measured in organs (i.e., livers and spleens) of live mice, and levels within the intestinal tract (the presumed origin of the gas) were four times greater than this. The half-saturation affinity of S. enterica serovar Typhimurium for H2 is only 2.1 microM, so it is expected that H2-utilizing hydrogenase enzymes are saturated with the reducing substrate in vivo. All three hydrogenase enzymes contribute to the virulence of the bacterium in a typhoid fever-mouse model, based on results from strains with mutations in each of the three hydrogenase genes. The introduced mutations are nonpolar, and growth of the mutant strains was like that of the parent strain. The combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast to the parent strain) one that is unable to invade liver or spleen tissue. The introduction of one of the hydrogenase genes into the triple mutant strain on a low-copy-number plasmid resulted in a strain that was able to both oxidize H2 and cause morbidity in mice within 11

Complete Whole-Genome Sequence of Salmonella enterica subsp. enterica Serovar Java NCTC5706.

Science.gov (United States)

Fazal, Mohammed-Abbas; Alexander, Sarah; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Parkhill, Julian; Russell, Julie E

2016-11-03

Salmonellae are a significant cause of morbidity and mortality globally. Here, we report the first complete genome sequence for Salmonella enterica subsp. enterica serovar Java strain NCTC5706. This strain is of historical significance, having been isolated in the pre-antibiotic era and was deposited into the National Collection of Type Cultures in 1939. © Crown copyright 2016.

Tetracycline promotes the expression of ten fimbrial operons in specific Salmonella enterica serovar Typhimurium isolates

Science.gov (United States)

Multidrug-resistant (MDR) Salmonella is associated with increased morbidity in humans and presents an important food safety concern. Antibiotic resistance among isolates of Salmonella enterica serovar Typhimurium has become especially prevalent as over 27 per cent of isolates from humans in the Unit...

Survival of Salmonella enterica serovar infantis on and within stored table eggs.

Science.gov (United States)

Lublin, Avishai; Maler, Ilana; Mechani, Sara; Pinto, Riky; Sela-Saldinger, Shlomo

2015-02-01

Contaminated table eggs are considered a primary source of foodborne salmonellosis globally. Recently, a single clone of Salmonella enterica serovar Infantis emerged in Israel and became the predominant serovar isolated in poultry. This clone is currently the most prevalent strain in poultry and is the leading cause of salmonellosis in humans. Because little is known regarding the potential transmission of this strain from contaminated eggs to humans, the objective of this study was to evaluate the ability of Salmonella Infantis to survive on the eggshell or within the egg during cold storage or at room temperature. Salmonella cells (5.7 log CFU per egg) were inoculated on the surface of 120 intact eggs or injected into the egg yolk (3.7 log CFU per egg) of another 120 eggs. Half of the eggs were stored at 5.5 ± 0.3°C and half at room temperature (25.5 ± 0.1°C) for up to 10 weeks. At both temperatures, the number of Salmonella cells on the shell declined by 2 log up to 4 weeks and remained constant thereafter. Yolk-inoculated Salmonella counts at cold storage declined by 1 log up to 4 weeks and remained constant, while room-temperature storage supported the growth of the pathogen to a level of 8 log CFU/ml of total egg content, as early as 4 weeks postinoculation. Examination of egg content following surface inoculation revealed the presence of Salmonella in a portion of the eggs at both temperatures up to 10 weeks, suggesting that this strain can also penetrate through the shell and survive within the egg. These findings imply that Salmonella enterica serovar Infantis is capable of survival both on the exterior and interior of table eggs and even multiply inside the egg at room temperature. Our findings support the need for prompt refrigeration to prevent Salmonella multiplication during storage of eggs at room temperature.

Effects of temperature on gene expression patterns in Leptospira interrogans serovar Lai as assessed by whole-genome microarrays.

Science.gov (United States)

Lo, Miranda; Bulach, Dieter M; Powell, David R; Haake, David A; Matsunaga, James; Paustian, Michael L; Zuerner, Richard L; Adler, Ben

2006-10-01

Leptospirosis is an important zoonosis of worldwide distribution. Humans become infected via exposure to pathogenic Leptospira spp. from infected animals or contaminated water or soil. The availability of genome sequences for Leptospira interrogans, serovars Lai and Copenhageni, has opened up opportunities to examine global transcription profiles using microarray technology. Temperature is a key environmental factor known to affect leptospiral protein expression. Leptospira spp. can grow in artificial media at a range of temperatures reflecting conditions found in the environment and the mammalian host. Therefore, transcriptional changes were compared between cultures grown at 20 degrees C, 30 degrees C, 37 degrees C, and 39 degrees C to represent ambient temperatures in the environment, growth under laboratory conditions, and temperatures in healthy and febrile hosts. Data from direct pairwise comparisons of the four temperatures were consolidated to examine transcriptional changes at two generalized biological conditions representing mammalian physiological temperatures (37 degrees C and 39 degrees C) versus environmental temperatures (20 degrees C and 30 degrees C). Additionally, cultures grown at 30 degrees C then shifted overnight to 37 degrees C were compared with those grown long-term at 30 degrees C and 37 degrees C to identify genes potentially expressed in the early stages of infection. Comparison of data sets from physiological versus environmental experiments with upshift experiments provided novel insights into possible transcriptional changes at different stages of infection. Changes included differential expression of chemotaxis and motility genes, signal transduction systems, and genes encoding proteins involved in alteration of the outer membrane. These findings indicate that temperature is an important factor regulating expression of proteins that facilitate invasion and establishment of disease.

Comparison of agglutinating and neutralizing antibodies to serovar hardjo in sows immunized with two commercial whole culture polivalent anti-leptospira bacterins

Science.gov (United States)

Soto, Francisco Rafael Martins; Pinheiro, Sônia Regina; Morais, Zenaide Maria; Gonçales, Amane Paldês; de Azevedo, Sérgio Santos; Bernardi, Fernanda; Camargo, Sebastião Rodrigues; Vasconcellos, Silvio Arruda

2008-01-01

It was performed the comparison of the intensity and duration of agglutinating and neutralizing antibodies to serovar Hardjo in swines vaccinated with two commercial anti-leptospira bacterins. Sows no reactive to 24 Leptospira sp serovars in the microscopic agglutination test (MAT) were divided in three groups: Group A (n=08): received two vaccine A doses with 30 days interval, Group B (n=08) two vaccine B doses with 30 days interval and Group C (n=08): control no vaccinated against leptospirosis.Blood samples were collected each 30 days during six months following the first vaccination. The sera were tested by MAT and growth inhibition test (GIT) to serovar Hardjo in order to evaluate respectively agglutinating and neutralizing antibodies. It was found that neutralizing antibodies persisted for a longer time than the agglutinating ones and that the absence of agglutinating antibodies does not means in the absence of the neutralizing. The peaks of agglutinating antibodies was obtained at least 30 days earlier than that produced by neutralizing. The duration of both kinds of antibodies measured differed between the two bacterines tested. The period for inducing neutralizing antibodies against serovar Hardjo indicated that gilts must be immunized with two doses of whole culture anti-leptospira bacterines applied 30 days each other at least 90 days before the first mating. For the maintenance of hight levels of neutralizing antibodies the revaccinations must be performed every six months after the first vaccination. PMID:24031250

Comparison of Chlamydia trachomatis serovar L2 growth in polarized genital epithelial cells grown in three-dimensional culture with non-polarized cells

OpenAIRE

Dessus-Babus, Sophie; Moore, Cheryl G.; Whittimore, Judy D.; Wyrick, Priscilla B.

2008-01-01

A common model for studying Chlamydia trachomatis and growing chlamydial stocks uses Lymphogranuloma venereum serovar L2 and non-polarized HeLa cells. However, recent publications indicate that the growth rate and progeny yields can vary considerably for a particular strain depending on the cell line/type used, and seem to be partially related to cell tropism. In the present study, the growth of invasive serovar L2 was compared in endometrial HEC-1B and endocervical HeLa cells polarized on co...

Improving resolution of public health surveillance for human Salmonella enterica serovar Typhimurium infection: 3 years of prospective multiple-locus variable-number tandem-repeat analysis (MLVA

Directory of Open Access Journals (Sweden)

Sintchenko Vitali

2012-03-01

Full Text Available Abstract Background Prospective typing of Salmonella enterica serovar Typhimurium (STM by multiple-locus variable-number tandem-repeat analysis (MLVA can assist in identifying clusters of STM cases that might otherwise have gone unrecognised, as well as sources of sporadic and outbreak cases. This paper describes the dynamics of human STM infection in a prospective study of STM MLVA typing for public health surveillance. Methods During a three-year period between August 2007 and September 2010 all confirmed STM isolates were fingerprinted using MLVA as part of the New South Wales (NSW state public health surveillance program. Results A total of 4,920 STM isolates were typed and a subset of 4,377 human isolates was included in the analysis. The STM spectrum was dominated by a small number of phage types, including DT170 (44.6% of all isolates, DT135 (13.9%, DT9 (10.8%, DT44 (4.5% and DT126 (4.5%. There was a difference in the discriminatory power of MLVA types within endemic phage types: Simpson's index of diversity ranged from 0.109 and 0.113 for DTs 9 and 135 to 0.172 and 0.269 for DTs 170 and 44, respectively. 66 distinct STM clusters were observed ranging in size from 5 to 180 cases and in duration from 4 weeks to 25 weeks. 43 clusters had novel MLVA types and 23 represented recurrences of previously recorded MLVA types. The diversity of the STM population remained relatively constant over time. The gradual increase in the number of STM cases during the study was not related to significant changes in the number of clusters or their size. 667 different MLVA types or patterns were observed. Conclusions Prospective MLVA typing of STM allows the detection of community outbreaks and demonstrates the sustained level of STM diversity that accompanies the increasing incidence of human STM infections. The monitoring of novel and persistent MLVA types offers a new benchmark for STM surveillance. A part of this study was presented at the MEEGID �

Ureaplasma parvum prosthetic joint infection detected by PCR.

Science.gov (United States)

Farrell, John J; Larson, Joshua A; Akeson, Jeffrey W; Lowery, Kristin S; Rounds, Megan A; Sampath, Rangarajan; Bonomo, Robert A; Patel, Robin

2014-06-01

We describe the first reported case of Ureaplasma parvum prosthetic joint infection (PJI) detected by PCR. Ureaplasma species do not possess a cell wall and are usually associated with colonization and infection of mucosal surfaces (not prosthetic material). U. parvum is a relatively new species name for certain serovars of Ureaplasma urealyticum, and PCR is useful for species determination. Our patient presented with late infection of his right total knee arthroplasty. Intraoperative fluid and tissue cultures and pre- and postoperative synovial fluid cultures were all negative. To discern the pathogen, we employed PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). Our patient's failure to respond to empirical antimicrobial treatment and our previous experience with PCR/ESI-MS in culture-negative cases of infection prompted us to use this approach over other diagnostic modalities. PCR/ESI-MS detected U. parvum in all samples. U. parvum-specific PCR testing was performed on all synovial fluid samples to confirm the U. parvum detection. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Effect of Enterococcus faecium EF 55 on morphometry and proliferative activity of intestinal mucosa in broilers infected with Salmonella Enteritidis

Directory of Open Access Journals (Sweden)

Ševčíková Zuzana

2016-09-01

Full Text Available Introduction: The present study aimed to investigate the effect of Enterococcus faecium EF55 on chickens, as well as its influence on proliferative activity of epithelial intestinal cells after infection with Salmonella enterica serovar Enteritidis phage type 4 (SE PT4. Moreover, the length and area of duodenal and jejunal villi of the birds were examined.

Salmonella infection and carriage in reptiles in a zoological collection.

Science.gov (United States)

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

2016-05-01

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

Curcumin increases the pathogenicity of Salmonella enterica serovar Typhimurium in murine model.

Directory of Open Access Journals (Sweden)

Sandhya A Marathe

Full Text Available Curcumin has gained immense importance for its vast therapeutic and prophylactic applications. Contrary to this, our study reveals that it regulates the defense pathways of Salmonella enterica serovar Typhimurium (S. Typhimurium to enhance its pathogenicity. In a murine model of typhoid fever, we observed higher bacterial load in Peyer's patches, mesenteric lymph node, spleen and liver, when infected with curcumin-treated Salmonella. Curcumin increased the resistance of S. Typhimurium against antimicrobial agents like antimicrobial peptides, reactive oxygen and nitrogen species. This increased tolerance might be attributed to the up-regulation of genes involved in resistance against antimicrobial peptides--pmrD and pmrHFIJKLM and genes with antioxidant function--mntH, sodA and sitA. We implicate that iron chelation property of curcumin have a role in regulating mntH and sitA. Interestingly, we see that the curcumin-mediated modulation of pmr genes is through the PhoPQ regulatory system. Curcumin downregulates SPI1 genes, required for entry into epithelial cells and upregulates SPI2 genes required to intracellular survival. Since it is known that the SPI1 and SPI2 system can be regulated by the PhoPQ system, this common regulator could explain curcumin's mode of action. This data urges us to rethink the indiscriminate use of curcumin especially during Salmonella outbreaks.

Expression, processing, and localization of PmpD of Chlamydia trachomatis Serovar L2 during the chlamydial developmental cycle.

Directory of Open Access Journals (Sweden)

Andrey O Kiselev

Full Text Available BACKGROUND: While families of polymorphic membrane protein (pmp genes have been identified in several Chlamydia species, their function remains mostly unknown. These proteins are of great interest, however, because of their location in the outer membrane and possible role in chlamydial virulence. METHODOLOGY/PRINCIPAL FINDING: We analyzed the relative transcription of the pmpD gene, a member of the pmp gene family in C. trachomatis serovar L2, and its protein product translation and processing during the chlamydial developmental cycle. By real-time reverse transcription polymerase chain reaction, the pmpD gene was found to be upregulated at 16 to 24 four hours after infection. Using polyclonal antibodies generated against the predicted passenger domain of PmpD, we demonstrated that it is initially localized on the surface of reticulate bodies, followed by its secretion outside Chlamydia starting at 24 hours after infection. In elementary bodies, we found a approximately 157 kDa PmpD only inside the cell. Both events, the upregulation of pmpD gene transcription and PmpD protein processing and secretion, are coincidental with the period of replication and differentiation of RBs into EBs. We also demonstrated that, in the presence of penicillin, the cleavage and secretion of the putative passenger domain was suppressed. CONCLUSION/SIGNIFICANCE: Our results are in agreement with the general concept that PmpD is an autotransporter protein which is post-translationally processed and secreted in the form of the putative passenger domain outside Chlamydia at mid- to- late point after infection, coinciding with the development of RBs into EBs.

Serovars of Salmonella isolated from Danish turkeys between 1995 and 2000 and their antimicrobial resistance

DEFF Research Database (Denmark)

Pedersen, Karl; Hansen, H.C.; Jørgensen, J.C.

2002-01-01

, florfenicol, or amoxycillin with clavulanic acid, only 24 isolates were resistant to two or more compounds in various combinations of up to six compounds; one Salmonella Havana isolate was resistant to six compounds. Six isolates were serovar Typhimurium, but none of them belonged to phage type DT104....

Breast abscess due to salmonella enterica serovar typhi in ayoung diabetic female

Directory of Open Access Journals (Sweden)

Lovely Barai

2013-01-01

Full Text Available Salmonella enterica serovar Typhi (S. Typhi is occasionally associated with abscess formation in various organs of the body. But breast abscess by S. Typhi without the general and specific symptoms of typhoid fever is unusual. We report a case of breast abscess due to S. Typhi in a 20 year old non-lactating diabetic female without the features of typhoid fever. Ibrahim Med. Coll. J. 2013; 7(1: 16-17

Epidemiology of a Salmonella enterica subsp. Enterica serovar Typhimurium strain associated with a songbird outbreak.

Science.gov (United States)

Blehert, David S.; Hernandez, Sonia M.; Keel, Kevin; Sanchez, Susan; Trees, Eija; ,

2012-01-01

Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast.

Stochastic simulation of endemic Salmonella enterica serovar Typhi: the importance of long lasting immunity and the carrier state.

Directory of Open Access Journals (Sweden)

Allan Saul

Full Text Available BACKGROUND: Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi remains a serious burden of disease, especially in developing countries of Asia and Africa. It is estimated that it causes 200,000 deaths per year, mainly in children. S. Typhi is an obligate pathogen of humans and although it has a relatively complex life cycle with a long lived carrier state, the absence of non-human hosts suggests that well targeted control methods should have a major impact on disease. Newer control methods including new generations of vaccines offer hope but their implementation would benefit from quantitative models to guide the most cost effective strategies. This paper presents a quantitative model of Typhoid disease, immunity and transmission as a first step in that process. METHODOLOGY/PRINCIPAL FINDINGS: A stochastic agent-based model has been developed that incorporates known features of the biology of typhoid including probability of infection, the consequences of infection, treatment options, acquisition and loss of immunity as a result of infection and vaccination, the development of the carrier state and the impact of environmental or behavioral factors on transmission. The model has been parameterized with values derived where possible from the literature and where this was not possible, feasible parameters space has been determined by sensitivity analyses, fitting the simulations to age distribution of field data. The model is able to adequately predict the age distribution of typhoid in two settings. CONCLUSIONS/SIGNIFICANCE: The modeling highlights the importance of variations in the exposure/resistance of infants and young children to infection in different settings, especially as this impacts on design of control programs; it predicts that naturally induced clinical and sterile immunity to typhoid is long lived and highlights the importance of the carrier state especially in areas of low transmission.

Microscopic agglutination test on captive rattlesnakes : Data on serovars and titers

Directory of Open Access Journals (Sweden)

T.C.S. Rodrigues

2016-06-01

Full Text Available The microscopic agglutination test (MAT is considered the “golden standard” leptospirosis serodiagnostic test, but there is little information about it as it pertains to snakes. To fill this information gap, we provide data on serovars and titers of fifty-six Crotalus durissus collilineatus sera samples that tested positive by MAT (10.1016/j.actatropica.2016.02.006 (Rodrigues et al., 2016 [5]. These data are presented in a table, along with a description of the methodology used for sample collection and serologic testing.

Salmonellosis in relation to chlamydiosis and pox and Salmonella infections in captive falcons in the United Arab Emirates.

Science.gov (United States)

Wernery, U; Wernery, R; Zachariah, R; Kinne, J

1998-12-01

During the spring of 1995, 1996 and 1997 following tests on six peregrine falcons (Falco peregrinus) and two gyr falcons (Falco rusticolus), Salmonella typhimurium was isolated from liver, spleen and small intestines. Four of the falcons (two peregrines and two gyrs) had also contracted Chlamydia infection, three peregrines a pox infection and one peregrine a Herpesvirus infection. It is believed that this dual infection was fatal for these birds. The disease was marked by anorexia, dehydration and green-coloured droppings. Necropsy of all falcons revealed discolouration of the liver and enlargement of liver and spleen. Miliary necrosis was detected in all livers. A total of 12 salmonella serovars, including S. typhimurium, were cultured from faeces of 48 falcons which showed no clinical signs.

TBK1 protects vacuolar integrity during intracellular bacterial infection.

Directory of Open Access Journals (Sweden)

Andrea L Radtke

2007-03-01

Full Text Available TANK-binding kinase-1 (TBK1 is an integral component of Type I interferon induction by microbial infection. The importance of TBK1 and Type I interferon in antiviral immunity is well established, but the function of TBK1 in bacterial infection is unclear. Upon infection of murine embryonic fibroblasts with Salmonella enterica serovar Typhimurium (Salmonella, more extensive bacterial proliferation was observed in tbk1(-/- than tbk1(+/+ cells. TBK1 kinase activity was required for restriction of bacterial infection, but interferon regulatory factor-3 or Type I interferon did not contribute to this TBK1-dependent function. In tbk1(-/-cells, Salmonella, enteropathogenic Escherichia coli, and Streptococcus pyogenes escaped from vacuoles into the cytosol where increased replication occurred, which suggests that TBK1 regulates the integrity of pathogen-containing vacuoles. Knockdown of tbk1 in macrophages and epithelial cells also resulted in increased bacterial localization in the cytosol, indicating that the role of TBK1 in maintaining vacuolar integrity is relevant in different cell types. Taken together, these data demonstrate a requirement for TBK1 in control of bacterial infection distinct from its established role in antiviral immunity.

TBK1 Protects Vacuolar Integrity during Intracellular Bacterial Infection

Science.gov (United States)

Radtke, Andrea L; Delbridge, Laura M; Balachandran, Siddharth; Barber, Glen N; O'Riordan, Mary X. D

2007-01-01

TANK-binding kinase-1 (TBK1) is an integral component of Type I interferon induction by microbial infection. The importance of TBK1 and Type I interferon in antiviral immunity is well established, but the function of TBK1 in bacterial infection is unclear. Upon infection of murine embryonic fibroblasts with Salmonella enterica serovar Typhimurium (Salmonella), more extensive bacterial proliferation was observed in tbk1−/− than tbk1+/+ cells. TBK1 kinase activity was required for restriction of bacterial infection, but interferon regulatory factor-3 or Type I interferon did not contribute to this TBK1-dependent function. In tbk1−/−cells, Salmonella, enteropathogenic Escherichia coli, and Streptococcus pyogenes escaped from vacuoles into the cytosol where increased replication occurred, which suggests that TBK1 regulates the integrity of pathogen-containing vacuoles. Knockdown of tbk1 in macrophages and epithelial cells also resulted in increased bacterial localization in the cytosol, indicating that the role of TBK1 in maintaining vacuolar integrity is relevant in different cell types. Taken together, these data demonstrate a requirement for TBK1 in control of bacterial infection distinct from its established role in antiviral immunity. PMID:17335348

A functional cra gene is required for Salmonella enterica serovar typhimurium virulence in BALB/c mice

DEFF Research Database (Denmark)

Allen, J. H.; Utley, M.; Van den Bosch, H.

2000-01-01

A minitransposon mutant of Salmonella enterica serovar Typhimurium SR-11, SR-11 Fad(-), is unable to utilize gluconeogenic substrates as carbon sources and is avirulent and immunogenic when administered perorally to BALB/c mice (M. J. Utley et al., FEMS Microbiol. Lett., 163:129-134, 1998). Here,...

Discovery of Novel Secreted Virulence Factors from Salmonella enterica Serovar Typhimurium by Proteomic Analysis of Culture Supernatants

Energy Technology Data Exchange (ETDEWEB)

Niemann, George; Brown, Roslyn N.; Gustin, Jean K.; Stufkens, Afke; Shaikh-Kidwai, Afshan S.; Li, Jie; McDermott, Jason E.; Brewer, Heather M.; Schepmoes, Athena A.; Smith, Richard D.; Adkins, Joshua N.; Heffron, Fred

2011-01-01

The intracellular pathogen Salmonella enterica serovar Typhimurium is a leading cause of acute gastroenteritis in the world. This pathogen has two type-III secretion systems (TTSS) necessary for virulence that are encoded in Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) and are expressed during extracellular or intracellular infectious states, respectively, to deliver virulence factors (effectors) to the host cell cytoplasm. While many have been identified and at least partially characterized, the full repertoire of effectors has not been catalogued. In this mass spectrometry-based proteomics study, we identified effector proteins secreted under minimal acidic medium growth conditions that induced the SPI-2 TTSS and its effectors, and compared the secretome from the parent strain to the secretome from strains missing either essential (SsaK) or regulatory components (SsaL) of the SPI-2 secretion apparatus. We identified 75% of the known TTSS effector repertoire. Excluding translocon components, 95% of the known effectors were biased for identification in the ssaL mutant background, which demonstrated that SsaL regulates SPI-2 type III secretion. To confirm secretion to animal cells, we made translational fusions of several of the best candidates to the calmodulin-dependent adenylate cyclase of Bordetella pertussis and assayed cAMP levels of infected J774 macrophage-like cells. From these infected cells we identified six new TTSS effectors and two others that are secreted independent of TTSS. Our results substantiate reports of additional secretion systems encoded by Salmonella other than TTSS.

Genital Mycoplasma and Chlamydia trachomatis infections in patients with genital tract infections attending a tertiary care hospital of North India

Directory of Open Access Journals (Sweden)

Karnika Saigal

2016-01-01

Full Text Available Limited data are available on the prevalence of genital mycoplasmas and Chlamydia trachomatis (CT among Indian patients with genital tract infections. The objectives of the study were to determine the prevalence of Ureaplasma urealyticum (UU, Mycoplasma hominis (MH, Mycoplasma genitalium (MG, and CT in patients with genital tract infections. The antimicrobial susceptibilities of UU and MH were also assessed. Endocervical swabs/urethral swabs and first void urine samples of patients (n = 164 were collected. UU and MH were detected by culture and multiplex polymerase chain reaction (PCR. MG and CT were identified by PCR. Ureaplasma isolates were further biotyped and serotyped. Antimicrobial susceptibility was done by microbroth dilution method. UU, MH, MG, and CT were detected in 15.2%, 5.4%, 1.2%, and 6% patients, respectively. Ureaplasma parvum serovar 3/14 was the most prevalent. All isolates of UU and MH were uniformly susceptible to doxycycline and josamycin. Routine screening for these pathogens and antimicrobial susceptibility testing is warranted to prevent sequel of infections and formulate treatment guidelines.

Development of Chronic and Acute Golden Syrian Hamster Infection Models with Leptospira borgpetersenii serovar Hardjo

Science.gov (United States)

The golden Syrian hamster (Mesocricetus auratus) is frequently used as a model to study virulence for several species of Leptospira. Onset of an acute, lethal infection following infection with several pathogenic Leptospira species has been widely adopted for vaccine testing. An important exceptio...

Transcriptomic analysis of swarm motility phenotype of Salmonella enterica serovar Typhimurium mutant defective in periplasmic glucan synthesis

Science.gov (United States)

Movement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. Salmonella enterica serovar Typhimurium mutants defective in OPG synthesis are unable to exhibit motility on moist surfaces (swarming) ...

Lack of efflux mediated quinolone resistance in Salmonella enterica serovars Typhi and Paratyphi A

Directory of Open Access Journals (Sweden)

Sylvie eBaucheron

2014-01-01

Full Text Available Salmonella enterica serovars Typhi and Paratyphi A isolates from human patients in France displaying different levels of resistance to quinolones or fluoroquinolones were studied for resistance mechanisms to these antimicrobial agents. All resistant isolates carried either single or multiple target gene mutations (i.e. in gyrA, gyrB, or parC correlating with the resistance levels observed. Active efflux, through upregulation of multipartite efflux systems, has also been previously reported as contributing mechanism for other serovars. Therefore, we investigated also the occurrence of non-target gene mutations in regulatory regions affecting efflux pump expression. However, no mutation was detected in these regions in both Typhi and Paratyphi isolates of this study. Besides, no overexpression of the major efflux systems was observed for these isolates. Nevertheless, a large deletion of 2334 bp was identified in the acrS-acrE region of all S. Typhi strains but which did not affect the resistance phenotype. As being specific to S. Typhi, this deletion could be used for specific molecular detection purposes. In conclusion, the different levels of quinolone or FQ resistance in both S. Typhi and S. Paratyphi A seem to rely only on target modifications.

Suitability of PCR fingerprinting, infrequent-restriction-site PCR, and pulsed-field gel electrophoresis, combined with computerized gel analysis, in library typing of Salmonella enterica serovar enteritidis

DEFF Research Database (Denmark)

Garaizar, J.; Lopez-Molina, N.; Laconcha, I.

2000-01-01

Strains of Salmonella enterica (n = 212) of different serovars and phage types were used to establish a library typing computerized system for serovar Enteritidis on the basis of PCR fingerprinting, infrequent-restriction-site PCR (IRS-PCR), or pulsed-field gel electrophoresis (PFGE). The rate...... showed an intercenter reproducibility value of 93.3%. The high reproducibility of PFGE combined with the previously determined high discrimination directed its use for library typing. The use of PFGE with enzymes XbaI, BlnI, and SpeI for library typing of serovar Enteritidis was assessed with GelCompar 4.......0 software, Three computer libraries of PFGE DNA profiles were constructed, and their ability to recognize new DNA profiles was analyzed. The results obtained pointed out that the combination of PFGE with computerized analysis could be suitable in long-term epidemiological comparison and surveillance...

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

Directory of Open Access Journals (Sweden)

Tze Y. Thung

2018-01-01

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

Lineage II (Serovar 1/2a and 1/2c) Human Listeria monocytogenes Pulsed-Field Gel Electrophoresis Types Divided into PFGE Groups Using the Band Patterns Below 145.5 kb.

Science.gov (United States)

Lopez-Valladares, Gloria; Danielsson-Tham, Marie-Louise; Goering, Richard V; Tham, Wilhelm

2017-01-01

Among 504 clinical lineage II isolates of Listeria monocytogenes isolated during 1958-2010 in Sweden, 119 pulsed-field gel electrophoresis (PFGE) types (AscI) have been identified based on the number and distribution of all banding patterns in each DNA profile. In this study, these types were further divided into PFGE groups based on the configuration of small bands with sizes kb. The 504 isolates included 483 serovar 1/2a isolates distributed into 114 PFGE types and 21 serovar 1/2c isolates distributed into 9 PFGE types; these were further divided into 21 PFGE groups. PFGE group, that is, configuration of small bands below 145.5 kb, and serovars were correlated. L. monocytogenes isolates belonging to PFGE groups A, B, C, E, F, H, K, L, M, S, V, W, Y, and Ö-6 to Ö-12 shared serovar 1/2a, with one exception. PFGE group E also included two PFGE types sharing serovar 1/2c and four PFGE types belonging to either serovar 1/2a or 1/2c. Isolates belonging to PFGE group N shared serovar 1/2c. In contrast to lineage I isolates, small fragments kb were visible in all L. monocytogenes isolates belonging to lineage II. In the results from both the present and previous studies, the genomic region of small bands was genetically more conservative than in large bands. The distribution of these small bands established the relatedness of strains and defined a genetic marker for both lineages I and II, while also establishing their serogroup. The division of L. monocytogenes PFGE types into PFGE groups is advantageous as the profile of every new isolate can be identified easily and quickly through first studying the PFGE group affiliation of the isolate based on the smaller band patterns kb, and then identifying the PFGE type based on the band patterns >145.5 kb.

Recurrent paratyphoid fever A co-infected with hepatitis A reactivated chronic hepatitis B.

Science.gov (United States)

Liu, Yanling; Xiong, Yujiao; Huang, Wenxiang; Jia, Bei

2014-05-12

We report here a case of recurrent paratyphoid fever A with hepatitis A co-infection in a patient with chronic hepatitis B. A 26-year-old male patient, who was a hepatitis B virus carrier, was co-infected with Salmonella enterica serovar Paratyphi A and hepatitis A virus. The recurrence of the paratyphoid fever may be ascribed to the coexistence of hepatitis B, a course of ceftriaxone plus levofloxacin that was too short and the insensitivity of paratyphoid fever A to levofloxacin. We find that an adequate course and dose of ceftriaxone is a better strategy for treating paratyphoid fever. Furthermore, the co-infection of paratyphoid fever with hepatitis A may stimulate cellular immunity and break immunotolerance. Thus, the administration of the anti-viral agent entecavir may greatly improve the prognosis of this patient with chronic hepatitis B, and the episodes of paratyphoid fever and hepatitis A infection prompt the use of timely antiviral therapy.

Use of a recombinant Salmonella enterica serovar Typhimurium strain expressing C-Raf for protection against C-Raf induced lung adenoma in mice

International Nuclear Information System (INIS)

Gentschev, Ivaylo; Fensterle, Joachim; Schmidt, Andreas; Potapenko, Tamara; Troppmair, Jakob; Goebel, Werner; Rapp, Ulf R

2005-01-01

Serine-threonine kinases of the Raf family (A-Raf, B-Raf, C-Raf) are central players in cellular signal transduction, and thus often causally involved in the development of cancer when mutated or over-expressed. Therefore these proteins are potential targets for immunotherapy and a possible basis for vaccine development against tumors. In this study we analyzed the functionality of a new live C-Raf vaccine based on an attenuated Salmonella enterica serovar Typhimurium aroA strain in two Raf dependent lung tumor mouse models. The antigen C-Raf has been fused to the C-terminal secretion signal of Escherichia coli α-hemolysin and expressed in secreted form by an attenuated aroA Salmonella enterica serovar Typhimurium strain via the α-hemolysin secretion pathway. The effect of the immunization with this recombinant C-Raf strain on wild-type C57BL/6 or lung tumor bearing transgenic BxB mice was analyzed using western blot and FACS analysis as well as specific tumor growth assays. C-Raf antigen was successfully expressed in secreted form by an attenuated Salmonella enterica serovar Typhimurium aroA strain using the E. coli hemolysin secretion system. Immunization of wild-type C57BL/6 or tumor bearing mice provoked specific C-Raf antibody and T-cell responses. Most importantly, the vaccine strain significantly reduced tumor growth in two transgenic mouse models of Raf oncogene-induced lung adenomas. The combination of the C-Raf antigen, hemolysin secretion system and Salmonella enterica serovar Typhimurium could form the basis for a new generation of live bacterial vaccines for the treatment of Raf dependent human malignancies

Pediatric Epidemic of Salmonella enterica Serovar Typhimurium in the Area of L’Aquila, Italy, Four Years after a Catastrophic Earthquake

Directory of Open Access Journals (Sweden)

Giovanni Nigro

2016-05-01

Full Text Available Background: A Salmonella enterica epidemic occurred in children of the area of L’Aquila (Central Italy, Abruzzo region between June 2013 and October 2014, four years after the catastrophic earthquake of 6 April 2009. Methods: Clinical and laboratory data were collected from hospitalized and ambulatory children. Routine investigations for Salmonella infection were carried out on numerous alimentary matrices of animal origin and sampling sources for drinking water of the L’Aquila district, including pickup points of the two main aqueducts. Results: Salmonella infection occurred in 155 children (83 females: 53%, aged 1 to 15 years (mean 2.10. Of these, 44 children (28.4% were hospitalized because of severe dehydration, electrolyte abnormalities, and fever resistant to oral antipyretic and antibiotic drugs. Three children (1.9% were reinfected within four months after primary infection by the same Salmonella strain. Four children (2.6%, aged one to two years, were coinfected by rotavirus. A seven-year old child had a concomitant right hip joint arthritis. The isolated strains, as confirmed in about the half of cases or probable/possible in the remaining ones, were identified as S. enterica serovar Typhimurium [4,5:i:-], monophasic variant. Aterno river, bordering the L’Aquila district, was recognized as the main responsible source for the contamination of local crops and vegetables derived from polluted crops. Conclusions: The high rate of hospitalized children underlines the emergence of a highly pathogenic S. enterica strain probably subsequent to the contamination of the spring water sources after geological changes occurred during the catastrophic earthquake.

Pediatric Epidemic of Salmonella enterica Serovar Typhimurium in the Area of L'Aquila, Italy, Four Years after a Catastrophic Earthquake.

Science.gov (United States)

Nigro, Giovanni; Bottone, Gabriella; Maiorani, Daniela; Trombatore, Fabiana; Falasca, Silvana; Bruno, Gianfranco

2016-05-06

A Salmonella enterica epidemic occurred in children of the area of L'Aquila (Central Italy, Abruzzo region) between June 2013 and October 2014, four years after the catastrophic earthquake of 6 April 2009. Clinical and laboratory data were collected from hospitalized and ambulatory children. Routine investigations for Salmonella infection were carried out on numerous alimentary matrices of animal origin and sampling sources for drinking water of the L'Aquila district, including pickup points of the two main aqueducts. Salmonella infection occurred in 155 children (83 females: 53%), aged 1 to 15 years (mean 2.10). Of these, 44 children (28.4%) were hospitalized because of severe dehydration, electrolyte abnormalities, and fever resistant to oral antipyretic and antibiotic drugs. Three children (1.9%) were reinfected within four months after primary infection by the same Salmonella strain. Four children (2.6%), aged one to two years, were coinfected by rotavirus. A seven-year old child had a concomitant right hip joint arthritis. The isolated strains, as confirmed in about the half of cases or probable/possible in the remaining ones, were identified as S. enterica serovar Typhimurium [4,5:i:-], monophasic variant. Aterno river, bordering the L'Aquila district, was recognized as the main responsible source for the contamination of local crops and vegetables derived from polluted crops. The high rate of hospitalized children underlines the emergence of a highly pathogenic S. enterica strain probably subsequent to the contamination of the spring water sources after geological changes occurred during the catastrophic earthquake.

Investigation on the presence of leptospires in ovaries of hamsters experimentally infected whith Leptospiras interrogans serovar pomona

Directory of Open Access Journals (Sweden)

Claudio Roberto de Almeida Camargo

1993-12-01

Full Text Available After inoculating L. interrogans serovar pomona in 75 primiparous hamsters (Mesocricetus auratus, the invasiveness of leptospires into lhe ovaries and lhe ability in causing ovary morphologic alterations were investigated by means of microscopic examination and bacterial isolation. For this purpose, 75 hamsters were inoculated with 0.5 ml of virulent strain containing 30-40 leptospires by the microscopic field and the other 15 hamsters were held as the uninfected controls. Signs and symptoms (prostration, tachypnea, rufled hair, jaundice, and nasal, bucal and perineal hemorrage were detected in all inoculated animals. The animals were killed in the agonic state of the illness, which were done through 4th and 7th day post inoculation. The ovaries were taken asseptically during the necropsies, thoroughly washed using the sterile phosphate buffered saline, in order to eliminate the possible external contamination. The fresh ovary samples were submitted to the dark field direct microscopic examination. After the formalin fixation, the specimens were stained by means of histopathologic techniques using the Levaditi and Hematoxylin Eosin stains. The ovary smears were also examined by the direct fluorescent antibody technique andlhe bacterial isolation was carried out in the Fletcher’s medium. The dark field direct microscopic examination was found tobe less sensitive in demonstrating the presence of leptospiresin the ovaries. In those specimens stained by the Lcvadititechnique, leptospires were visualized in different ovaryinternal structures, involving the interspace, pellucid zone andin the inner ovules. Through the histopathologic examination,typical morphologic alterations resembling acute infiamatoryprocess were found in 57% of ovaries examined.

Antibacterial activity of vegetal extracts against serovars of Salmonella Atividade antibacteriana de extratos vegetais sobre sorovares de Salmonella

Directory of Open Access Journals (Sweden)

Daiane Voss-Rech

2011-02-01

Full Text Available in vitro antibacterial activity of 21 hydroethanolic vegetal extracts was assessed against 20 serovars of Salmonella. Regarding the tested extracts, 85.7% of them presented antibacterial activity. The six active extracts which showed activity on the largest number of serovars and the extract of Eucalyptus sp. were submitted to the determination of Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC. Of these, six extracts showed bacteriostatic and bactericidal activity with MIC and MBC for Punica granatum (pomegranate from 20 and 60mg mL-1, for Eugenia jambolana (rose apple from 40 and 240mg mL-1, Eugenia uniflora (surinam cherry from 80 and 240mg mL-1, Caryophyllus aromaticus (clove from 10 and 60mg mL-1, Psidium araca from 30 and 320mg mL-1 and Eucalyptus sp. from 40 and 160mg mL-1. Achyrocline satureioides (macela presented only bacteriostatic potential and MIC from 160mg mL-1. Caryophyllus aromaticus, Eucalyptus sp., and Psidium araca presented the best results for bactericidal activity, inhibiting, respectively, 84.2%, 42.1%, and 17.6% of Salmonella's serovars. The activity of each extract varied for different serovars; S. London presented resistance to the six extracts in MBC, while S. Pullorum was the most susceptible serovar.A atividade antibacteriana de 21 extratos hidroetanólicos vegetais foi avaliada in vitro frente a 20 sorovares de Salmonella. Dos extratos testados, 85,7% apresentaram atividade antibacteriana. Os seis extratos que evidenciaram atividade sobre o maior número de sorovares e Eucalyptus sp. foram submetidos à determinação da Concentração Inibitória Mínima (CIM e Concentração Bactericida Mínima (CBM. Destes, seis extratos apresentaram atividade bacteriostática e bactericida com MIC para Punica granatum (romã a partir de 20 e 60mg mL-1, Eugenia jambolana (jambolão de 40 e 240mg mL-1, Eugenia uniflora (pitanga de 80 e 240mg mL-1, Caryophyllus aromaticus (cravo de 10 e 60mg mL-1

Critical role of glycogen synthase kinase-3β in regulating the avian heterophil response to Salmonella enterica serovar Enteritidis

Directory of Open Access Journals (Sweden)

Michael eKogut

2014-11-01

Full Text Available A microarray-assisted gene expression screen of chicken heterophils revealed glycogen synthase kinase-3β (GSK-3β, a multifunctional Ser/Thr kinase, to be consistently up-regulated 30-180 min following stimulation with Salmonella enterica serovar Enteritidis (S. Enteritidis. The present study was designed to delineate the role of GSK-3β in regulating the innate function of chicken heterophils in response to S. Enteritidis exposure. Using a specific GSK-3β ELISA assay, 30 min after infection with S. Enteritidis, heterophils had a significant decrease in total GSK-3β, but a significant increase in phosphorylated GSK-3 (Ser9. By 60 min post-infection, there was no difference in the amount of phosphorylated GSK-3β (Ser9 in either the uninfected and infected heterophils. S. Enteritidis interaction with heterophils alters GSK-3 activity by stimulating phosphorylation at Ser9 and that peaks by 30 min post-infection. Further, inhibition of GSK3β with lithium chloride resulted in a significant decrease in NF-κB activation and expression of IL-6, but induces a significant increase in the expression of the anti-inflammatory cytokine, IL-10. Using a phospho-specific antibody array confirmed the phosphorylation of GSK-3β (Ser9 as well as the phosphorylation of the downstream cytokine-activated intracellular signaling pathway involved in stimulating immune responses, IκB, the IκB subunit IKK-β, and the NF-κB subunits p105, p65, and c-Rel. Our data revealed that the phosphorylation of GSK-3β (Ser9 is responsible for inducing and controlling an innate response to the bacteria. Our findings suggest that the repression of GSK-3 activity is beneficial to the host cell and may act as a target for treatment in controlling intestinal colonization in chickens. Further experiments will define the in vivo modulation of GSK-3 as a potential alternative to antibiotics in salmonella and other intestinal bacterial infections.

The transcriptional landscape and small RNAs of Salmonella enterica serovar Typhimurium

DEFF Research Database (Denmark)

Kröger, Carsten; Dillon, Shane C.; Cameron, Andrew D. S.

2012-01-01

More than 50 y of research have provided great insight into the physiology, metabolism, and molecular biology of Salmonella enterica serovar Typhimurium (S. Typhimurium), but important gaps in our knowledge remain. It is clear that a precise choreography of gene expression is required......-thirds of these TSSs were associated with σ70 (including phoP, slyA, and invF) from which we identified the −10 and −35 motifs of σ70-dependent S. Typhimurium gene promoters. Overall, we corrected the location of important genes and discovered 18 times more promoters than identified previously. S. Typhimurium...

Analysis of the clonal relationship among clinical isolates of Salmonella enterica serovar Infantis by different typing methods Análisis de la relación clonal entre aislamientos clínicos de Salmonella enterica serovar Infantis mediante diferentes métodos de tipificación

Directory of Open Access Journals (Sweden)

Luis A. Merino

2003-06-01

Full Text Available Salmonella Infantis has been the second most common serovar in Argentina in the last two years, being isolated mostly from paediatric hospitalised patients. In order to determine the clonal relationship among Salmonella Infantis strains, we examined 15 isolates from paediatric patient faeces in Argentina (12 geographically related and 3 geographically non-related by using antimicrobial susceptibility, plasmid profiling, repetitive extragenic palindromic (REP PCR, enterobacterial repetitive intergenic consensus (ERIC PCR, and low-frequency restriction analysis of chromosomal DNA by pulsed field gel electrophoresis (PFGE. Four Spanish strains were included as controls of clonal diversity in molecular techniques. Antibiotype and plasmid profile was not useful as epidemiological tools. PFGE and REP-PCR were able to discriminate between Argentinean and Spanish isolates of Salmonella Infantis allowing to detect genetically related strains in three different cities. This finding indicates that a possible spread of a clone of this serovar in the North-eastern Region of Argentina has taken place in 1998.Salmonella Infantis ha sido el segundo serovar más común en la Argentina en los últimos dos años, siendo aislada principalmente, a partir de pacientes pediátricos hospitalizados. La relación clonal entre 15 aislamientos de Salmonella Infantis obtenidos de heces de pacientes pediátricos en Argentina se estudió mediante la susceptibilidad antimicrobiana, el perfil plasmídico, amplificación por reacción en cadena de la polimerasa (PCR de las secuencias repetitivas REP y ERIC, y electroforesis de ADN total en campo pulsátil (PFGE. Cuatro cepas españolas fueron incluidas como control de diversidad clonal. El antibiotipo y el perfil plasmídico no fueron herramientas útiles en la tipificación. PFGE y REP-PCR fueron capaces de discriminar entre las cepas argentinas y españolas de Salmonella Infantis, permitiendo detectar cepas gen

Characterization and identification of early proteins in Chlamydia trachomatis serovar L2 by two-dimensional gel electrophoresis

DEFF Research Database (Denmark)

Lundemose, AG; Birkelund, Svend; Larsen, PM

1990-01-01

The synthesis of early proteins from Chlamydia trachomatis serovar L2 was analyzed by two-dimensional gel electrophoresis. By pulse-label experiments, the synthesis of seven proteins was observed at 2 to 8 h postinfection before the major outer membrane protein was detected at 8 to 10 h after...

Evaluation of immunogenicity and protective efficacy of recombinant outer membrane proteins of Haemophilus parasuis serovar 5 in a murine model.

Science.gov (United States)

Li, Miao; Cai, Ru-Jian; Song, Shuai; Jiang, Zhi-Yong; Li, Yan; Gou, Hong-Chao; Chu, Pin-Pin; Li, Chun-Ling; Qiu, Hua-Ji

2017-01-01

Glässer's disease is an economically important infectious disease of pigs caused by Haemophilus parasuis. Few vaccines are currently available that could provide effective cross-protection against various serovars of H. parasuis. In this study, five OMPs (OppA, TolC, HxuC, LppC, and HAPS_0926) identified by bioinformatic approaches, were cloned and expressed as recombinant proteins. Antigenicity of the purified proteins was verified through Western blotting, and primary screening for protective potential was evaluated in vivo. Recombinant TolC (rTolC), rLppC, and rHAPS_0926 proteins showing marked protection of mice against H. parasuis infection, and were further evaluated individually or in combination. Mice treated with these three OMPs produced humoral and host cell-mediated responses, with a significant rise in antigen-specific IgG titer and lymphoproliferative response in contrast with the mock-immunized group. Significant increases were noted in CD4+, CD8+ T cells, and three cytokines (IL-2, IL-4, and IFN-γ) in vaccinated animals. The antisera against candidate antigens could efficiently impede bacterial survival in whole blood bactericidal assay against H. parasuis infection. The multi-protein vaccine induced more pronounced immune responses and offered better protection than individual vaccines. Our findings indicate that these three OMPs are promising antigens for the development of multi-component subunit vaccines against Glässer's disease.

Investigation of an outbreak of Salmonella enterica serovar Newport infection.

Science.gov (United States)

Irvine, W N; Gillespie, I A; Smyth, F B; Rooney, P J; McClenaghan, A; Devine, M J; Tohani, V K

2009-10-01

A large outbreak of Salmonella enterica serotype Newport infection occurred in Northern Ireland during September and October 2004. Typing of isolates from patients confirmed that this strain was indistinguishable from that in concurrent outbreaks in regions of England, in Scotland and in the Isle of Man. A total of 130 cases were distributed unequally across local government district areas in Northern Ireland. The epidemic curve suggested a continued exposure over about 4 weeks. A matched case-control study of 23 cases and 39 controls found a statistically significant association with a history of having eaten lettuce in a meal outside the home and being a case (odds ratio 23.7, 95% confidence interval 1.4-404.3). This exposure was reported by 57% of cases. Although over 300 food samples were tested, none yielded any Salmonella spp. Complexity and limited traceability in salad vegetable distribution hindered further investigation of the ultimate source of the outbreak.

Salmonella Typhimurium undergoes distinct genetic adaption during chronic infections of mice

DEFF Research Database (Denmark)

Søndberg, Emilie; Jelsbak, Lotte

2016-01-01

Background Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) is a severe systemic human disease and endemic in regions of the world with poor drinking water quality and sewage treatment facilities. A significant number of patients become asymptomatic life-long carriers of S....... In the current study genetic adaptation during experimental chronic S. Typhimurium infections of mice, an established model of chronic typhoid fever, was probed as an approach for studying the molecular mechanisms of host-adaptation during long-term host-association. Results Individually sequence-tagged wild...

Molecular Characterization of Extended-Spectrum Cephalosporinase-Producing Salmonella enterica Serovar Choleraesuis Isolates from Patients in Thailand and Denmark

DEFF Research Database (Denmark)

Sirichote, P.; Hasman, Henrik; Pulsrikarn, C.

2010-01-01

isolates were recovered from 21 Thai patients during 2003, 2007, or 2008 and one isolate was recovered from a Danish traveler to Thailand. ESC production was confirmed in 13 out of the 24 isolates by MIC testing. Microarray and plasmid profiling (replicon typing and restriction fragment length polymorphism...... on susceptibility patterns, the ESC-producing isolates were more closely related than non-ESC-producing isolates. Microarray, PCR, plasmid profiling, and replicon typing revealed that the 13 ESC-producing isolates harbored either bla(CMY-2) containing incA/C or bla(CTX-M-14) containing incFIIA, inc......FrepB, and an unknown replicon located on plasmids ranging in size from 75 to 200 kb. The RFLP and replicon typing clustered the isolates into four distinct groups. PFGE revealed 16 unique patterns and five clusters; each cluster contained two or three of the 24 isolates. The isolate from the Danish patient...

A rapid and specific detection of pathogenic serovar Salmonella typhimurium by loop-mediated isothermal amplification method (LAMP

Directory of Open Access Journals (Sweden)

Hadi Ravan

2017-09-01

Discussion and conclusion: As a result of a high sensitivity and specificity of the method as well as its low cost per assay, it could be concluded that the present LAMP assay is a powerful, accurate, and efficient method for detecting pathogenic serovar Salmonella typhimurium in food-processing industries and diagnostic laboratories.

Salmonella Typhimurium undergoes distinct genetic adaption during chronic infections of mice

DEFF Research Database (Denmark)

Søndberg, Emilie; Jelsbak, Lotte

2016-01-01

Background Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) is a severe systemic human disease and endemic in regions of the world with poor drinking water quality and sewage treatment facilities. A significant number of patients become asymptomatic life-long carriers of S....... Typhi and serve as the reservoir for the disease. The specific mechanisms and adaptive strategies enabling S. Typhi to survive inside the host for extended periods are incompletely understood. Yet, elucidation of these processes is of major importance for improvement of therapeutic strategies...... been transmitted to the other two mice. Re-infection with this clone confirmed that it is superior to the wild type for intestinal colonisation. Conclusions During 4 to 6 weeks of chronic infections, S. Typhimurium acquired distinct SNPs in known regulators of metabolic and virulence genes. One SNP...

Histopathology case definition of naturally acquired Salmonella enterica serovar Dublin infection in young Holstein cattle in the northeastern United States.

Science.gov (United States)

Pecoraro, Heidi L; Thompson, Belinda; Duhamel, Gerald E

2017-11-01

Salmonella enterica subsp. enterica serovar Dublin ( Salmonella Dublin) is a host-adapted bacterium that causes high morbidity and mortality in dairy cattle worldwide. A retrospective search of archives at the New York Animal Health Diagnostic Center revealed 57 culture-confirmed Salmonella Dublin cases from New York and Pennsylvania in which detailed histology of multiple tissues was available. Tissues routinely submitted by referring veterinarians for histologic evaluation included sections of heart, lungs, liver, spleen, and lymph nodes. Of the 57 S almonella Dublin-positive cases, all were Holstein breed, 53 were female (93%), and 49 (86%) were 90% (45 of 49) of lungs, 90% (28 of 31) of livers, 50% (11 of 22) of spleens, and 62% (18 of 29) of lymph nodes examined had moderate-to-severe inflammation with or without necrosis. Inconstant lesions were seen in 48% (10 of 21) of hearts examined, and consisted of variable inflammatory infiltrates and rare areas of necrosis. We propose a histopathology case definition of Salmonella Dublin in cattle that includes a combination of pulmonary alveolar capillary neutrophilia with or without hepatocellular necrosis and paratyphoid granulomas, splenitis, and lymphadenitis. These findings will assist in the development of improved protocols for the diagnosis of infectious diseases of dairy cattle.

In Vitro Characterization of Lactobacillus plantarum Strains with Inhibitory Activity on Enteropathogens for Use as Potential Animal Probiotics.

Science.gov (United States)

Palaniyandi, Sasikumar Arunachalam; Damodharan, Karthiyaini; Suh, Joo-Won; Yang, Seung Hwan

2017-06-01

The present study evaluates the probiotic properties of three Lactobacillus plantarum strains MJM60319, MJM60298, and MJM60399 possessing antimicrobial activity against animal enteric pathogens. The three strains did not show bioamine production, mucinolytic and hemolytic activity and were susceptible to common antibiotics. The L. plantarum strains survived well in the simulated orogastrointestinal transit condition and showed adherence to Caco-2 cells in vitro. The L. plantarum strains showed strong antimicrobial activity against enterotoxigenic Escherichia coli , Shiga toxin-producing E. coli , Salmonella enterica subsp. enterica serovar Typhimurium, Choleraesuis and Gallinarum compared to the commercial probiotic strain Lactobacillus rhamnosus GG. The mechanism of antimicrobial activity of the L. plantarum strains appeared to be by the production of lactic acid. Furthermore, the L. plantarum strains tolerated freeze-drying and maintained higher viability in the presence of cryoprotectants than without cryoprotectants. Finally, the three L. plantarum strains tolerated NaCl up to 8% and maintained >60% growth. These characteristics of the three L. plantarum strains indicate that they could be applied as animal probiotic after appropriate in vivo studies.

Ascertaining the relationship between Salmonella Typhimurium and Salmonella 4,[5],12:i:- by MLVA and inferring the sources of human salmonellosis due to the two serovars in Italy

DEFF Research Database (Denmark)

Barco, Lisa; Barrucci, Federica; Cortini, Enzo

2015-01-01

The current picture of human salmonellosis shows Salmonella Typhimurium and S. 4,[5],12:i:- as the most common serovars in Italy. The aims of this study were to investigate the genetic relationship between these serovars, as well as to test the possibility of inferring sources of human...... salmonellosis due to S. Typhimurium and S. 4,[5],12:i:- by using multilocus variable-number tandem repeat analysis (MLVA) subtyping data. Single isolates from 268 human sporadic cases and 325 veterinary isolates (from pig, cattle, chicken, and turkey) collected over the period 2009-2011 were typed by MLVA......, and the similarities of MLVA profiles were investigated using different analytical approaches. Results showed that isolates of S. 4,[5],12:i:- were more clonal compared to S. Typhimurium and that clones of both serovars from different non-human sources were very close to those which were responsible for human...

Leptospira infections in freshwater fish in Morogoro Tanzania: a ...

African Journals Online (AJOL)

The objectives of this study were to determine presence of Leptospira in fish; the prevalent Leptospira serovars and whether are related to serovars reported in animals; and to ascertain potential public health risk. Live tilapia, catfish and eel fish (n=48) were caught in Mindu Dam in Morogoro Municipality in eastern Tanzania ...

Effect of Challenge Temperature and Solute Type on Heat Tolerance of Salmonella Serovars at Low Water Activity

Science.gov (United States)

Mattick, K. L.; Jørgensen, F.; Wang, P.; Pound, J.; Vandeven, M. H.; Ward, L. R.; Legan, J. D.; Lappin-Scott, H. M.; Humphrey, T. J.

2001-01-01

Salmonella spp. are reported to have an increased heat tolerance at low water activity (aw; measured by relative vapor pressure [rvp]), achieved either by drying or by incorporating solutes. Much of the published data, however, cover only a narrow treatment range and have been analyzed by assuming first-order death kinetics. In this study, the death of Salmonella enterica serovar Typhimurium DT104 when exposed to 54 combinations of temperature (55 to 80°C) and aw (rvp 0.65 to 0.90, reduced using glucose-fructose) was investigated. The Weibull model (LogS = −btn) was used to describe microbial inactivation, and surface response models were developed to predict death rates for serovar Typhimurium at all points within the design surface. The models were evaluated with data generated by using six different Salmonella strains in place of serovar Typhimurium DT104 strain 30, two different solutes in place of glucose-fructose to reduce aw, or six low-aw foods artificially contaminated with Salmonella in place of the sugar broths. The data demonstrate that, at temperatures of ≥70°C, Salmonella cells at low aw were more heat tolerant than those at a higher aw but below 65°C the reverse was true. The same patterns were generated when sucrose (rvp 0.80 compared with 0.90) or NaCl (0.75 compared with 0.90) was used to reduce aw, but the extent of the protection afforded varied with solute type. The predictions of thermal death rates in the low-aw foods were usually fail-safe, but the few exceptions highlight the importance of validating models with specific foods that may have additional factors affecting survival. PMID:11526015

Organoid and Enteroid Modeling of Salmonella Infection

Directory of Open Access Journals (Sweden)

Yuebang Yin

2018-04-01

Full Text Available Salmonella are Gram-negative rod-shaped facultative anaerobic bacteria that are comprised of over 2,000 serovars. They cause gastroenteritis (salmonellosis with headache, abdominal pain and diarrhea clinical symptoms. Salmonellosis brings a heavy burden for the public health in both developing and developed countries. Antibiotics are usually effective in treating the infected patients with severe gastroenteritis, although antibiotic resistance is on the rise. Understanding the molecular mechanisms of Salmonella infection is vital to combat the disease. In vitro immortalized 2-D cell lines, ex vivo tissues/organs and several animal models have been successfully utilized to study Salmonella infections. Although these infection models have contributed to uncovering the molecular virulence mechanisms, some intrinsic shortcomings have limited their wider applications. Notably, cell lines only contain a single cell type, which cannot reproduce some of the hallmarks of natural infections. While ex vivo tissues/organs alleviate some of these concerns, they are more difficult to maintain, in particular for long term experiments. In addition, non-human animal models are known to reflect only part of the human disease process. Enteroids and induced intestinal organoids are emerging as effective infection models due to their closeness in mimicking the infected tissues/organs. Induced intestinal organoids are derived from iPSCs and contain mesenchymal cells whereas enteroids are derive from intestinal stem cells and are comprised of epithelial cells only. Both enteroids and induced intestinal organoids mimic the villus and crypt domains comparable to the architectures of the in vivo intestine. We review here that enteroids and induced intestinal organoids are emerging as desired infection models to study bacterial-host interactions of Salmonella.

Serological and molecular characterization of leptospira serovar Kenya from captive African giant pouched rats (Cricetomys gambianus) from Morogoro Tanzania

NARCIS (Netherlands)

Machang'u, R. S.; Mgode, G. F.; Assenga, J.; Mhamphi, G.; Weetjens, B.; Cox, C.; Verhagen, R.; Sondij, S.; Goris, M. G.; Hartskeerl, R. A.

2004-01-01

Two identical leptospiral isolates coded Sh9 and Sh25 obtained from the urine of captive African giant pouched rats (Cricetomys gambianus), destined for use as biodetector of antipersonnel landmines were typed as serovar Kenya using cross-agglutination absorption test and DNA fingerprinting with the

Quantification of contamination of lettuce by GFP-expressing Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium

NARCIS (Netherlands)

Franz, Eelco; Visser, Anna A; Van Diepeningen, Anne D; Klerks, Michel M; Termorshuizen, Aad J; van Bruggen, Ariena H C

The primary objective of this study was to determine the possibility of internalization of GFP-expressing Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium (S. Typhimurium) strains MAE 110 (multi-cellular morphology) and 119 (wild type morphology) into lettuce seedlings (Lactuca

The female lower genital tract is a privileged compartment with IL-10 producing dendritic cells and poor Th1 immunity following Chlamydia trachomatis infection.

Directory of Open Access Journals (Sweden)

Ellen Marks

Full Text Available While a primary genital tract infection with C. trachomatis stimulates partial-protection against re-infection, it may also result in severe inflammation and tissue destruction. Here we have dissected whether functional compartments exist in the genital tract that restrict Th1-mediated protective immunity. Apart from the Th1-subset, little is known about the role of other CD4(+ T cell subsets in response to a genital tract chlamydial infection. Therefore, we investigated CD4(+ T cell subset differentiation in the genital tract using RT-PCR for expression of critical transcription factors and cytokines in the upper (UGT and lower genital tract (LGT of female C57BL/6 mice in response to C. trachomatis serovar D infection. We found that the Th1 subset dominated the UGT, as IFN-γ and T-bet mRNA expression were high, while GATA-3 was low following genital infection with C. trachomatis serovar D. By contrast, IL-10 and GATA-3 mRNA dominated the LGT, suggesting the presence of Th2 cells. These functional compartments also attracted regulatory T cells (Tregs differently as increased FoxP3 mRNA expression was seen primarily in the UGT. Although IL-17A mRNA was somewhat up-regulated in the LGT, no significant change in RORγ-t mRNA expression was observed, suggesting no involvement of Th17 cells. The dichotomy between the LGT and UGT was maintained during infection by IL-10 because in IL-10-deficient mice the distinction between the two compartments was completely lost and a dramatic shift to the predominance of Th1 cells in the LGT occurred. Unexpectedly, the major source of IL-10 was CD11c(+ CD11b(+ DC, probably creating an anti-inflammatory privileged site in the LGT.

Influence of ethanol adaptation on Salmonella enterica serovar Enteritidis survival in acidic environments and expression of acid tolerance-related genes

Science.gov (United States)

Aims: Salmonella enterica serovar Enteritidis (S. Enteritidis) can encounter mild ethanol stress during its life cycle. However, adaptation to a stressful condition may affect bacterial resistance to subsequent stresses. Hence, this work was undertaken to investigate the influences of ethanol adapta...

Leptospira interrogans stably infects zebrafish embryos, altering phagocyte behavior and homing to specific tissues.

Directory of Open Access Journals (Sweden)

J Muse Davis

2009-06-01

Full Text Available Leptospirosis is an extremely widespread zoonotic infection with outcomes ranging from subclinical infection to fatal Weil's syndrome. Despite the global impact of the disease, key aspects of its pathogenesis remain unclear. To examine in detail the earliest steps in the host response to leptospires, we used fluorescently labelled Leptospira interrogans serovar Copenhageni to infect 30 hour post fertilization zebrafish embryos by either the caudal vein or hindbrain ventricle. These embryos have functional innate immunity but have not yet developed an adaptive immune system. Furthermore, they are optically transparent, allowing direct visualization of host-pathogen interactions from the moment of infection. We observed rapid uptake of leptospires by phagocytes, followed by persistent, intracellular infection over the first 48 hours. Phagocytosis of leptospires occasionally resulted in formation of large cellular vesicles consistent with apoptotic bodies. By 24 hours, clusters of infected phagocytes were accumulating lateral to the dorsal artery, presumably in early hematopoietic tissue. Our observations suggest that phagocytosis may be a key defense mechanism in the early stages of leptospirosis, and that phagocytic cells play roles in immunopathogenesis and likely in the dissemination of leptospires to specific target tissues.

Characterization of antimicrobial resistance in Salmonella enterica food and animal isolates from Colombia: identification of a qnrB19-mediated quinolone resistance marker in two novel serovars

DEFF Research Database (Denmark)

Karczmarczyk, M.; Martins, M.; McCusker, M.

2010-01-01

Ninety-three Salmonella isolates recovered from commercial foods and exotic animals in Colombia were studied. The serotypes, resistance profiles and where applicable the quinolone resistance genes were determined. Salmonella Anatum (n=14), Uganda (19), Braenderup (10) and Newport (10) were the most...... plasmids, two of which were completely sequenced. These exhibited 97% (serovar 6,7:d:- isolate) and 100% (serovar Infantis isolate) nucleotide sequence identity with previously identified ColE-like plasmids. This study demonstrates the occurrence of the qnrB19 gene associated with small ColE plasmids...

Zinc Supplementation, via GPR39, Upregulates PKCζ to Protect Intestinal Barrier Integrity in Caco-2 Cells Challenged by Salmonella enterica Serovar Typhimurium.

Science.gov (United States)

Shao, Yu-Xin; Lei, Zhao; Wolf, Patricia G; Gao, Yan; Guo, Yu-Ming; Zhang, Bing-Kun

2017-07-01

Background: Zinc has been shown to improve intestinal barrier function against Salmonella enterica serovar Typhimurium ( S. typhimurium ) infection, but the mechanisms involved in this process remain undefined. Objective: We aimed to explore the roles of G protein-coupled receptor (GPR)39 and protein kinase Cζ (PKCζ) in the regulation by zinc of intestinal barrier function. Methods: A Transwell Caco-2 monolayer was pretreated with 0, 50, or 100 μM Zn and then incubated with S. typhimurium for 0-6 h. Afterward, cells silenced by the small interfering RNA for GPR39 or PKCζ were pretreated with 100 μM Zn and incubated with S. typhimurium for 3 h. Finally, transepithelial electrical resistance (TEER), permeability, tight junction (TJ) proteins, and signaling molecules GPR39 and PKCζ were measured. Results: Compared with controls, S. typhimurium decreased TEER by 62.3-96.2% at 4-6 h ( P 0.1). Silencing GPR39 decreased ( P zinc-activated PKCζ and blocked ( P zinc on epithelial integrity. Furthermore, silencing PKCζ counteracted the protective effect of zinc on epithelial integrity but did not inhibit GPR39 ( P = 0.138). Conclusion: We demonstrated that zinc upregulates PKCζ by activating GPR39 to enhance the abundance of ZO-1, thereby improving epithelial integrity in S. typhimurium- infected Caco-2 cells. © 2017 American Society for Nutrition.

Simultaneous oral administration of Salmonella Infantis and S. Typhimurium in chicks.

Science.gov (United States)

Murakami, Koichi; Maeda-Mitani, Eriko; Onozuka, Daisuke; Noda, Tamie; Sera, Nobuyuki; Kimura, Hirokazu; Fujimoto, Shuji; Murakami, Satoshi

2017-01-01

To confirm the hypothesis that Salmonella enterica subspecies enterica serovar ( S. ) Infantis has higher basic reproductive rates in chicks compared with other Salmonella serovars, 1-day-old specific-pathogen-free chicks ( n  = 8) were challenged simultaneously with S. Infantis and S. Typhimurium per os . Challenged chicks (Group A) were then housed with non-infected chicks (Group B, n  = 4) for 6 days (from 2 to 8 days of age). Group B birds were then housed with other non-infected birds (Group C, n  = 4), which were then transferred to cages containing a further group of untreated chicks (Group D, n  = 2). A control group consisting of four non-infected chicks was used for comparison. All chickens were humanely sacrificed at 18 days of age, and Salmonella from bowel and liver samples were enumerated. Both serovars were isolated from all groups except the control group. S. Typhimurium was isolated at a greater frequency than S. Infantis from the bowel samples of chicks from Groups B, C and D, while no differences in colonisation rates were observed between the two serovars in liver samples from Groups B, C and D. S. Typhimurium, but not S. Infantis, was immunohistochemically detected in the lamina propria of the cecum and rectum in five birds of Group A. Despite the competitive administration, neither of the two serovars completely excluded the other, and no differences were observed in basic reproductive rates between the two serovars. These findings, together with data from previous studies, suggest that the initial quantitative domination of S. Infantis in chicken flocks may explain why this serovar is predominant in broiler chickens.

Characterization of a multidrug-resistant Salmonella enterica serovar Heidelberg outbreak strain in commercial turkeys: Colonization, transmission, and host transcriptional response

Science.gov (United States)

In recent years, multidrug-resistant (MDR) Salmonella enterica serovar Heidelberg has been associated with numerous human foodborne illness outbreaks due to consumption of poultry. For example, in 2011, an MDR S. Heidelberg outbreak associated with ground turkey sickened 136 individuals and resulted...

Effects of P22 bacteriophage on salmonella Enterica subsp. enterica serovar Typhimurium DMC4 strain biofilm formation and eradication

Directory of Open Access Journals (Sweden)

Karaca Basar

2015-01-01

Full Text Available Over the last decades, several antimicrobial agents have been made available. Due to increasing antimicrobial resistance, bacteriophages were rediscovered for their potential applications against bacterial infections. In the present study, biofilm inhibition and eradication of Salmonella enterica subsp. enterica serovar Typhimurium DMC4 strain (S. Typhimurium was evaluated with respect to different incubation periods at different P22 phage titrations. The efficacy of P22 phage on biofilm formation and eradication of S. Typhimurium DMC4 strain was screened in vitro on polystyrene and stainless steel surfaces. The biofilm forming capacity of S. Typhimurium was significantly reduced at higher phage titrations (106 pfu/mL ≤. All phage titers (104-108 pfu/mL were found to be effective at the end of the 24 h-incubation period whereas higher phage titrations were found to be effective at the end of the 48 h and 72 h of incubation. P22 phage has less efficacy on already formed, especially mature biofilms (72 h-old biofilm. Notable results of P22 phage treatment on S. Typhimurium biofilm suggest that P22 phage has potential uses in food systems.

The commercial impact of pig Salmonella spp. infections in border-free markets during an economic recession.

Science.gov (United States)

Evangelopoulou, G; Kritas, S; Christodoulopoulos, G; Burriel, A R

2015-03-01

The genus Salmonella, a group of important zoonotic pathogens, is having global economic and political importance. Its main political importance results from the pathogenicity of many of its serovars for man. Serovars Salmonella Enteritidis and Salmonella Typhimurium are currently the most frequently associated to foodborne infections, but they are not the only ones. Animal food products contaminated from subclinically infected animals are a risk to consumers. In border free markets, an example is the EU, these consumers at risk are international. This is why, economic competition could use the risk of consumer infection either to restrict or promote free border trade in animals and their products. Such use of public health threats increases during economic recessions in nations economically weak to effectively enforce surveillance. In free trade conditions, those unable to pay the costs of pathogen control are unable to effectively implement agreed regulations, centrally decided, but leaving their enforcement to individual states. Free trade of animal food products depends largely on the promotion of safety, included in "quality," when traders target foreign markets. They will overtake eventually the markets of those ineffectively implementing agreed safety regulations, if their offered prices are also attractive for recession hit consumers. Nations unable to effectively enforce safety regulations become disadvantaged partners unequally competing with producers of economically robust states when it comes to public health. Thus, surveillance and control of pathogens like Salmonella are not only quantitative. They are also political issues upon which states base national trade decisions. Hence, the quantitative calculation of costs incurring from surveillance and control of animal salmonelloses, should not only include the cost for public health protection, but also the long term international economic and political costs for an individual state. These qualitative

Expression of Bacillus thuringiensis serovar. israelensis toxins in Asticcacaulis excentricus to control dipteran larvae of vectors of diseases

Directory of Open Access Journals (Sweden)

Óscar Enrique Guevara

2004-01-01

Full Text Available Bacillus thuringiensis cry genes encode for a diverse group of crystal-forming proteins that exhibit insecticidal activity towards dipteran, lepidopteran and coleopteran larvae. The effectiveness of insecticides based on mosquito larvicidal B. thuringiensis strains can be enhanced by using aquatic prosthecated bacteria as alternative hosts, since they do not sink, cytoplasmic located toxins are protected f rom UV radiation and, most importantly, mosquito larvae feed on them. An Asticcacaulis excentricus reference strain was transformed with the cry1 1Aa gene from Bacillus thuringiensis serovar. israelensis. Western blot and electrophoresis were used to test recombinant protein expression; Western blot revealed a 72 kDa protein corresponding to B. thuringiensis serovar. israelensis Cry1 1 Aa. These aquatic bacte­rias toxicity achieved 50% mortality at 23 ng/mL concentration in f irst instar Culex quinquefasciatus larvae. Other bioassays indicated that recombinant A. excentricus is toxic against Aedes aegyptiand Anopheles albimanus first instar larvae. Buoyancy tests demonstrated the advantage of A. excentricus over B. thuringiensis. Key words: Asticcacaulis excentricus, Bacillus thuringiensis, prosthecated bacteria, dengue, malaria.

Investigations of Salmonella enterica serovar newport infections of oysters by using immunohistochemistry and knockout mutagenesis.

Science.gov (United States)

Morrison, Christopher M; Dial, Sharon M; Day, William A; Joens, Lynn A

2012-04-01

The consumption of raw oysters is an important risk factor in the acquisition of food-borne disease, with Salmonella being one of a number of pathogens that have been found in market oysters. Previous work by our lab found that Salmonella was capable of surviving in oysters for over 2 months under laboratory conditions, and this study sought to further investigate Salmonella's tissue affinity and mechanism of persistence within the oysters. Immunohistochemistry was used to show that Salmonella was capable of breaching the epithelial barriers, infecting the deeper connective tissues of the oysters, and evading destruction by the oysters' phagocytic hemocytes. To further investigate the mechanism of these infections, genes vital to the function of Salmonella's two main type III secretion systems were disrupted and the survivability of these knockout mutants within oysters was assayed. When the Salmonella pathogenicity island 1 and 2 mutant strains were exposed to oysters, there were no detectable deficiencies in their abilities to survive, suggesting that Salmonella's long-term infection of oysters does not rely upon these two important pathogenicity islands and must be due to some other, currently unknown, mechanism.

High resolution clustering of Salmonella enterica serovar Montevideo strains using a next-generation sequencing approach

Directory of Open Access Journals (Sweden)

Allard Marc W

2012-01-01

Full Text Available Abstract Background Next-Generation Sequencing (NGS is increasingly being used as a molecular epidemiologic tool for discerning ancestry and traceback of the most complicated, difficult to resolve bacterial pathogens. Making a linkage between possible food sources and clinical isolates requires distinguishing the suspected pathogen from an environmental background and placing the variation observed into the wider context of variation occurring within a serovar and among other closely related foodborne pathogens. Equally important is the need to validate these high resolution molecular tools for use in molecular epidemiologic traceback. Such efforts include the examination of strain cluster stability as well as the cumulative genetic effects of sub-culturing on these clusters. Numerous isolates of S. Montevideo were shot-gun sequenced including diverse lineage representatives as well as numerous replicate clones to determine how much variability is due to bias, sequencing error, and or the culturing of isolates. All new draft genomes were compared to 34 S. Montevideo isolates previously published during an NGS-based molecular epidemiological case study. Results Intraserovar lineages of S. Montevideo differ by thousands of SNPs, that are only slightly less than the number of SNPs observed between S. Montevideo and other distinct serovars. Much less variability was discovered within an individual S. Montevideo clade implicated in a recent foodborne outbreak as well as among individual NGS replicates. These findings were similar to previous reports documenting homopolymeric and deletion error rates with the Roche 454 GS Titanium technology. In no case, however, did variability associated with sequencing methods or sample preparations create inconsistencies with our current phylogenetic results or the subsequent molecular epidemiological evidence gleaned from these data. Conclusions Implementation of a validated pipeline for NGS data acquisition and

Analysis of mutations in DNA gyrase and topoisomerase IV of Ureaplasma urealyticum and Ureaplasma parvum serovars resistant to fluoroquinolones.

Science.gov (United States)

Piccinelli, Giorgio; Gargiulo, Franco; Biscaro, Valeria; Caccuri, Francesca; Caruso, Arnaldo; De Francesco, Maria Antonia

2017-01-01

This study aims to determine the prevalence of fluoroquinolone resistance of Ureaplasma biovars and serovars isolated from urogenital clinical samples and determine the underlying molecular mechanism for quinolone resistance for all resistant isolates. Of 105 samples confirmed as positive for U. urealyticum/U. parvum, 85 were resistant to quinolones by the Mycoplasma-IST2 kit. However, only 43 out of 85 quinolone resistant isolates had amino acid substitutions in GyrA, GyrB, ParC and ParE proteins underlining that this assay have mis-identified as fluoroquinolone resistant 42 isolates. The known ParC E87K and ParC S83L mutations were found in 1 and 10 isolates, respectively. An original mutation of ureaplasmal ParC (E87Q, 1 isolate) was found. Furthermore, we found a ParE R448K mutation in one isolate, already described. Among the additional alterations detected, the most prevalent mutation found was L176F in GyrA protein in 18 isolates with single infection and in 3 isolates with mixed ureaplasma infections. Mutations in GyrB (E502Q, 4 isolates), ParE (Q412K, Q412P, Q412T, 3 independent isolates), whose role is unknown, were also found. Other sporadic mutations in the four genes were identified. This investigation is the result of monitoring the data for molecular fluoroquinone resistance in Ureaplasma spp. in Italy. Resulting that this acquired resistance is high and that continued local epidemiological studies are essential to monitor and document their antimicrobial resistance trends. Copyright © 2016 Elsevier B.V. All rights reserved.

Prevalence of antimicrobial resistance of non-typhoidal Salmonella serovars in retail aquaculture products.

Science.gov (United States)

Zhang, Jianmin; Yang, Xiaowei; Kuang, Dai; Shi, Xianming; Xiao, Wenjia; Zhang, Jing; Gu, Zhen; Xu, Xuebin; Meng, Jianghong

2015-10-01

Aquaculture products can become sources of Salmonella by exposure to contaminated water or through processing practices, thus representing a public health hazard. A study was conducted on Salmonella contamination in aquaculture products sampled from marketplaces and retailers in Shanghai, China. A total of 730 samples (including fish, shellfish, bullfrog, clam, shrimp and others) were obtained from 2006 to 2011. Among them, 217 (29.7%) were positive for Salmonella. Thirty-eight serovars were identified in the 217 Salmonella isolates. The most prevalent were Salmonella Aberdeen (18.4%), S. Wandsworth (12.0%), S. Thompson (9.2%), S. Singapore (5.5%), S. Stanley (4.6%), S. Schwarzengrund (4.6%), S. Hvittingfoss (4.1%) and S. Typhimurium (4.1%). Many resistant isolates were detected, with 69.6% resistant to at least one antimicrobial drug. We observed high resistance to sulfonamides (56.5%), tetracycline (34.1%), streptomycin (28.6%), ampicillin (23.5%) and nalidixic acid (21.2%). Lower levels of resistance were found for gentamicin (3.2%), ciprofloxacin (2.3%), ceftiofur (1.3%), cefotaxime (0.9%), ceftazidime (0.5%) and cefepime (0.5%). A total of 43.3% of the Salmonella isolates were multidrug-resistant and 44 different resistance patterns were found. This study provided data on the prevalence, serovars and antimicrobial resistance of Salmonella from retail aquaculture products in Shanghai, and indicated the need for monitoring programs for microbiologic safety in such projects and for more prudent drug use in aquaculture production in order to reduce the risk of development and spread of antimicrobial resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative analysis of core genome MLST and SNP typing within a European Salmonella serovar Enteritidis outbreak.

Science.gov (United States)

Pearce, Madison E; Alikhan, Nabil-Fareed; Dallman, Timothy J; Zhou, Zhemin; Grant, Kathie; Maiden, Martin C J

2018-06-02

Multi-country outbreaks of foodborne bacterial disease present challenges in their detection, tracking, and notification. As food is increasingly distributed across borders, such outbreaks are becoming more common. This increases the need for high-resolution, accessible, and replicable isolate typing schemes. Here we evaluate a core genome multilocus typing (cgMLST) scheme for the high-resolution reproducible typing of Salmonella enterica (S. enterica) isolates, by its application to a large European outbreak of S. enterica serovar Enteritidis. This outbreak had been extensively characterised using single nucleotide polymorphism (SNP)-based approaches. The cgMLST analysis was congruent with the original SNP-based analysis, the epidemiological data, and whole genome MLST (wgMLST) analysis. Combination of the cgMLST and epidemiological data confirmed that the genetic diversity among the isolates predated the outbreak, and was likely present at the infection source. There was consequently no link between country of isolation and genetic diversity, but the cgMLST clusters were congruent with date of isolation. Furthermore, comparison with publicly available Enteritidis isolate data demonstrated that the cgMLST scheme presented is highly scalable, enabling outbreaks to be contextualised within the Salmonella genus. The cgMLST scheme is therefore shown to be a standardised and scalable typing method, which allows Salmonella outbreaks to be analysed and compared across laboratories and jurisdictions. Copyright © 2018. Published by Elsevier B.V.

Getting “Inside” Type I IFNs: Type I IFNs in Intracellular Bacterial Infections

Directory of Open Access Journals (Sweden)

Deann T. Snyder

2017-01-01

Full Text Available Type I interferons represent a unique and complex group of cytokines, serving many purposes during innate and adaptive immunity. Discovered in the context of viral infections, type I IFNs are now known to have myriad effects in infectious and autoimmune disease settings. Type I IFN signaling during bacterial infections is dependent on many factors including whether the infecting bacterium is intracellular or extracellular, as different signaling pathways are activated. As such, the repercussions of type I IFN induction can positively or negatively impact the disease outcome. This review focuses on type I IFN induction and downstream consequences during infection with the following intracellular bacteria: Chlamydia trachomatis, Listeria monocytogenes, Mycobacterium tuberculosis, Salmonella enterica serovar Typhimurium, Francisella tularensis, Brucella abortus, Legionella pneumophila, and Coxiella burnetii. Intracellular bacterial infections are unique because the bacteria must avoid, circumvent, and even co-opt microbial “sensing” mechanisms in order to reside and replicate within a host cell. Furthermore, life inside a host cell makes intracellular bacteria more difficult to target with antibiotics. Because type I IFNs are important immune effectors, modulating this pathway may improve disease outcomes. But first, it is critical to understand the context-dependent effects of the type I IFN pathway in intracellular bacterial infections.

Seroepidemiological detection of antibodies against Leptospira spp using microscopic agglutination test in Urmia cows and sheep

Directory of Open Access Journals (Sweden)

Ramin Ag

2013-01-01

Full Text Available The study was designed to determine the level of incidence, titer and various serovars of leptospira in 203 cows and 166 sheep at Urmia abattoir in 2011. Blood samples were collected during the slaughter of animals and sera were separated to evaluate the serological reaction to Leptospira spp by Microscopic Agglutination Test (MAT using live antigens representing Leptospira interrogans serogroups: pomona, grippotyphosa, canicola, hardjo, icterrohaemoragiae, and ballum. Overall, 36% of cows and 19.3% of sheep including 33.8% of bulls, 40.5% of female cows, 18.3% of rams and 25% of ewes had a positive reaction to at least one of the leptospira serovars. The most prevalent serovars in cows were pomona (22.7%, grippotyphosa (13.8%, and hardjo (8.4%, and in sheep were grippotyphosa (66.7%, pomona (26.2% and canicola (7.1%. Other serovars were not detected in cows and sheep. The most prevalent serological titers of 1:100 and 1:200 in cows was 18.2% and 26.6%, and for sheep were 13.5% and 8%, respectively, and of 1:400 in sheep was 2.3%. Cows with a positive reaction to one, two and three serovars were 28.6%, 5.9%, and 1.5% and sheep positive to one and two serovars were 13.3% and 6%, respectively. Age comparison in seropositive cows and sheep showed a significantly increased infection (p<0.05 from young to adult ruminants, while no differences were seen regarding gender. The main mixed serovars were between grippotyphosa/pomona, grippotyphosa/canicola and canicola/pomona. The gender comparison of the serovars' distribution revealed that the pomona and grippotyphosa were predominant among other leptospiral serovars in cows and sheep, respectively. In conclusion, the rate of leptospirosis in Urmia cows was about 2 fold in sheep. The most current serovars in cows and sheep were pomona and grippotyphosa, respectively. The majority of animals was infected with one serovar, but polyserovars, are also possible. The highest titer (1:200 was observed in cows

Neonatal CNS infection and inflammation caused by Ureaplasma species: rare or relevant?

Science.gov (United States)

Glaser, Kirsten; Speer, Christian P

2015-02-01

Colonization with Ureaplasma species has been associated with adverse pregnancy outcome, and perinatal transmission has been implicated in the development of bronchopulmonary dysplasia in preterm neonates. Little is known about Ureaplasma-mediated infection and inflammation of the CNS in neonates. Controversy remains concerning its incidence and implication in the pathogenesis of neonatal brain injury. In vivo and in vitro data are limited. Despite improving care options for extremely immature preterm infants, relevant complications remain. Systematic knowledge of ureaplasmal infection may be of great benefit. This review aims to summarize pathogenic mechanisms, clinical data and diagnostic pitfalls. Studies in preterm and term neonates are critically discussed with regard to their limitations. Clinical questions concerning therapy or prophylaxis are posed. We conclude that ureaplasmas may be true pathogens, especially in preterm neonates, and may cause CNS inflammation in a complex interplay of host susceptibility, serovar pathogenicity and gestational age-dependent CNS vulnerability.

Demonstration of persistent contamination of a cooked egg product production facility with Salmonella enterica serovar Tennessee and characterization of the persistent strain.

Science.gov (United States)

Jakočiūnė, D; Bisgaard, M; Pedersen, K; Olsen, J E

2014-08-01

The aim of this study was to investigate whether continuous contamination of light pasteurized egg products with Salmonella enterica serovar Tennessee (S. Tennessee) at a large European producer of industrial egg products was caused by persistent contamination of the production facility and to characterize the persistent strains. Seventy-three S. Tennessee isolates collected from products over a 3-year period with intermittent contamination, and 15 control strains were compared by pulsed field gel electrophoresis (PFGE) using two enzymes. Forty-five case isolates distributed throughout the full period were shown to belong to one profile type. Isolates representing different PFGE profiles were all assigned to ST 319 by multilocus sequence typing (MLST). The case isolates did not show a higher ability to form biofilm on a plastic surface than noncase isolates. Characteristically, members of the persistent clone were weak producers of H2 S in laboratory medium. S. Tennessee isolated from the case was able to grow better in pasteurized egg product compared with other serovars investigated. It was concluded that the contamination was caused by a persistent strain in the production facility and that this strain apparently had adapted to grow in the relevant egg product. S. Tennessee has previously been associated with persistence in hatching facilities. This is the first report of persistent contamination of an egg production facility with this serovar. © 2014 The Society for Applied Microbiology.

Prevalence, serovars, phage types, and antibiotic susceptibilities of Salmonella strains isolated from animals in the United Arab Emirates from 1996 to 2009.

Science.gov (United States)

Münch, Sebastian; Braun, Peggy; Wernery, Ulrich; Kinne, Jörg; Pees, Michael; Flieger, Antje; Tietze, Erhard; Rabsch, Wolfgang

2012-10-01

The aim of this study was to give some insights into the prevalence, serovars, phage types, and antibiotic resistances of Salmonella from animal origin in the United Arab Emirates. Data on diagnostic samples from animals (n = 20,871) examined for Salmonella between 1996 and 2009 were extracted from the databases of the Central Veterinary Research Laboratory in Dubai and from typed strains (n = 1052) from the Robert Koch Institute, Wernigerode Branch in Germany and analyzed for general and animal-specific trends. Salmonella was isolated from 1,928 (9 %) of the 20,871 samples examined. Among the 1,052 typed strains, most were from camels (n = 232), falcons (n = 166), bustards (n = 101), antelopes (n = 66), and horses (n = 63). The predominant serovars were Salmonella Typhimurium (25 %), Salmonella Kentucky (8 %), followed by Salmonella Frintrop (7 %), and Salmonella Hindmarsh (5 %). When analyzed by animal species, the most frequent serovars in camels were Salmonella Frintrop (28 %) and Salmonella Hindmarsh (21 %), in falcons Salmonella Typhimurium (32 %), in bustards Salmonella Kentucky (19 %), in antelopes Salmonella Typhimurium (9 %), and in horses Salmonella Typhimurium (17 %) and S. Kentucky (16 %). Resistance of all typed Salmonella strains (n = 1052) was most often seen to tetracycline (23 %), streptomycin (22 %), nalidixic acid (18 %), and ampicillin (15 %). These data show trends in the epidemiology of Salmonella in different animal species which can be used as a base for future prevention, control, and therapy strategies.

Evidence for the transmission of Salmonella from reptiles to children in Germany, July 2010 to October 2011.

Science.gov (United States)

Pees, M; Rabsch, W; Plenz, B; Fruth, A; Prager, R; Simon, S; Schmidt, V; Munch, S; Braun, Pg

2013-11-14

This study examines the Salmonella status in reptiles kept in households with children suffering from gastroenteritis due to an exotic Salmonella serovar, to obtain information on possible transmission paths. A number of affected households (n=79) were contacted, and almost half (34/79) comprised at least one reptile in the home. Of the households, 19 were further studied, whereby a total of 36 reptiles were investigated. Samples were taken from the reptiles including the oral cavity, the cloaca, the skin and, in the case of lizards, the stomach, and isolation of Salmonella strains was performed using repeated enrichment and typing. Where the Salmonella serovars of the infected child and the reptile were identical, typing was followed by pulsed-field gel electrophoresis (PFGE). Bearded dragons (Pogona vitticeps) constituted 19 of 36 examined reptiles. Altogether 319 Salmonella isolates were investigated and 24 different serovars identified in the reptiles. In 15 of 19 households, an identical serovar to the human case was confirmed in at least one reptile (including 16 of all 19 bearded dragons examined). The results demonstrate that reptiles and especially bearded dragons shed various Salmonella serovars including those isolated from infected children in the respective households. Hygiene protocols and parents' education are therefore highly necessary to reduce the risk of transmission. From a terminological point of view, we propose to call such infections 'Reptile-Exotic-Pet-Associated-Salmonellosis' (REPAS).

Demonstration of persistent contamination of a cooked egg product production facility with Salmonella enterica serovar Tennessee and characterization of the persistent strain

DEFF Research Database (Denmark)

Jakociune, D.; Bisgaard, M.; Pedersen, Karl

2014-01-01

Aims: The aim of this study was to investigate whether continuous contamination of light pasteurized egg products with Salmonella enterica serovar Tennessee (S. Tennessee) at a large European producer of industrial egg products was caused by persistent contamination of the production facility......, members of the persistent clone were weak producers of H2S in laboratory medium. S. Tennessee isolated from the case was able to grow better in pasteurized egg product compared with other serovars investigated. Conclusions: It was concluded that the contamination was caused by a persistent strain...... in the production facility and that this strain apparently had adapted to grow in the relevant egg product. Significance and Impact of the Study: S. Tennessee has previously been associated with persistence in hatching facilities. This is the first report of persistent contamination of an egg production facility...

BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF SALMONELLA-ENTERICA SEROVAR BERTA, AND COMPARISON OF METHODS FOR TYPING

DEFF Research Database (Denmark)

Olsen, J. E.; Brown, D. J.; Baggesen, Dorte Lau

1992-01-01

Strains of Salmonella enterica serovar berta (S. berta) from Denmark and seven other countries have been characterized with the aim of developing a rational typing strategy in connection with outbreak investigations, Biotyping divided the strains into H2S-positive (90 %) and H2S-negative (10...... with restriction enzyme analysis of plasmids seemed to be the most rational typing strategy for S. berta. The results indicated that S. berta strains regardless of geographical source or host are possibly clonal in nature....

Involvement of SPI-2-encoded SpiC in flagellum synthesis in Salmonella enterica serovar Typhimurium

Directory of Open Access Journals (Sweden)

Sugita Asami

2009-08-01

Full Text Available Abstract Background SpiC encoded within Salmonella pathogenicity island 2 on the Salmonella enterica serovar Typhimurium chromosome is required for survival within macrophages and systemic infection in mice. Additionally, SpiC contributes to Salmonella-induced activation of the signal transduction pathways in macrophages by affecting the expression of FliC, a component of flagella filaments. Here, we show the contribution of SpiC in flagellum synthesis. Results Quantitative RT-PCR shows that the expression levels of the class 3 fliD and motA genes that encode for the flagella cap and motor torque proteins, respectively, were lower for a spiC mutant strain than for the wild-type Salmonella. Further, this mutant had lower expression levels of the class 2 genes including the fliA gene encoding the flagellar-specific alternative sigma factor. We also found differences in flagella assembly between the wild-type strain and the spiC mutant. Many flagella filaments were observed on the bacterial surface of the wild-type strain, whereas the spiC mutant had only few flagella. The absence of spiC led to reduced expression of the FlhD protein, which functions as the master regulator in flagella gene expression, although no significant difference at the transcription level of the flhDC operon was observed between the wild-type strain and the spiC mutant. Conclusion The data show that SpiC is involved in flagella assembly by affecting the post-transcription expression of flhDC.

Pathogenicity of Salmonella Strains Isolated from Egg Shells and the Layer Farm Environment in Australia

Science.gov (United States)

McWhorter, Andrea R.; Davos, Dianne

2014-01-01

In Australia, the egg industry is periodically implicated during outbreaks of Salmonella food poisoning. Salmonella enterica serovar Typhimurium and other nontyphoidal Salmonella spp., in particular, are a major concern for Australian public health. Several definitive types of Salmonella Typhimurium strains, but primarily Salmonella Typhimurium definitive type 9 (DT9), have been frequently reported during egg-related food poisoning outbreaks in Australia. The aim of the present study was to generate a pathogenicity profile of nontyphoidal Salmonella isolates obtained from Australian egg farms. To achieve this, we assessed the capacity of Salmonella isolates to cause gastrointestinal disease using both in vitro and in vivo model systems. Data from in vitro experiments demonstrated that the invasion capacity of Salmonella serovars cultured to stationary phase (liquid phase) in LB medium was between 90- and 300-fold higher than bacterial suspensions in normal saline (cultured in solid phase). During the in vivo infection trial, clinical signs of infection and mortality were observed only for mice infected with either 103 or 105 CFU of S. Typhimurium DT9. No mortality was observed for mice infected with Salmonella serovars with medium or low invasive capacity in Caco-2 cells. Pathogenicity gene profiles were also generated for all serovars included in this study. The majority of serovars tested were positive for selected virulence genes. No relationship between the presence or absence of virulence genes by PCR and either in vitro invasive capacity or in vivo pathogenicity was detected. Our data expand the knowledge of strain-to-strain variation in the pathogenicity of Australian egg industry-related Salmonella spp. PMID:25362057

Sources of human non-typhoid salmonellosis: a review

Directory of Open Access Journals (Sweden)

OC de Freitas Neto

2010-03-01

Full Text Available Salmonellosis is a worldwide disease caused by bacteria of the genus Salmonella. Currently, there are over 2,500 identified serovars of Salmonella. A reduced number of these serovars, about eighty, are implicated in most animals and human diseases. Most cases of salmonellosis in humans are associated with the consumption of contaminated food products such as beef, pork, poultry meat, eggs, vegetables, juices and other kind of foods. It may also be associated with the contact between humans and infected pet animals. Therefore, the chain of human salmonellosis is very complex and in most cases the origin of the infection is difficult to establish. The use of antimicrobial agents to treat and to prevent bacterial infections in humans and animals, as well as as growth promoters in animal production, has favoured the selection and transference of resistance genes between different bacteria, including Salmonella serovars. Many studies have confirmed the role of foods of animal origin as a source of multi drugresistant Salmonella serovars. For this reason, continuous surveillance of these pathogens along the food chain together with the responsible use of antimicrobial agents is necessary.

Interactions of virulent and avirulent leptospires with primary cultures of renal epithelial cells

DEFF Research Database (Denmark)

Ballard, S A; Williamson, M; Adler, B

1986-01-01

A primary culture system for the cells of mouse renal-tubular epithelium was established and used to observe the adhesion of leptospires. Virulent strains of serovars copenhageni and ballum attached themselves to epithelial cells within 3 h of infection whereas an avirulent variant of serovar cop...

Seropositivity to Leptospira interrogans serovar Bratislava associated to reproductive problems without significant biochemical or hematological alterations in horses Soropositividade para Leptospira interrogans serovar Bratislava associada a falhas reprodutivas sem alterações hematológicas e bioquímicas significativas em cavalos

Directory of Open Access Journals (Sweden)

Melissa Pinna

2010-10-01

Full Text Available The objective was to study haematological and biochemical alterations associated to seropositivity to Leptospira interrogans serovar Bratislava infection in horses with reproductive alterations, such as neonatal deaths, embryonic deaths and abortions. A flock of mares with poor reproductive performance was studied. Eighty-two (58.6% were seropositive (titre 200; 72 of those (87.8% for Bratislava. Slight haematological and biochemical alterations were observed, being more frequent (PO objetivo deste trabalho foi estudar alterações hematológicas e bioquímicas associadas à soropositividade para Leptospira interrogans sorovar Bratislava em cavalos com alterações reprodutivas, tais como mortes neonatais, absorção embrionária e abortamentos. Um rebanho de éguas com baixos índices reprodutivos foi estudado. Oitenta e duas (58,6% foram soropositivas (títulos 200, sendo 72 destas (87,8% para Bratislava. Foram observadas poucas alterações hematológicas e bioquímicas, mais frequentes (P<0,05 em éguas soropositivas do que soronegativas. Cavalos soropositivos para Bratislava não tinham alterações graves nos valores hematológicos e bioquímicos. Esses achados reforçam que esse sorovar seja adaptado de cavalos e cause apenas sintomas brandos, associados a falhas reprodutivas.

The M3 muscarinic receptor is required for optimal adaptive immunity to helminth and bacterial infection.

Directory of Open Access Journals (Sweden)

Matthew Darby

2015-01-01

Full Text Available Innate immunity is regulated by cholinergic signalling through nicotinic acetylcholine receptors. We show here that signalling through the M3 muscarinic acetylcholine receptor (M3R plays an important role in adaptive immunity to both Nippostrongylus brasiliensis and Salmonella enterica serovar Typhimurium, as M3R-/- mice were impaired in their ability to resolve infection with either pathogen. CD4 T cell activation and cytokine production were reduced in M3R-/- mice. Immunity to secondary infection with N. brasiliensis was severely impaired, with reduced cytokine responses in M3R-/- mice accompanied by lower numbers of mucus-producing goblet cells and alternatively activated macrophages in the lungs. Ex vivo lymphocyte stimulation of cells from intact BALB/c mice infected with N. brasiliensis and S. typhimurium with muscarinic agonists resulted in enhanced production of IL-13 and IFN-γ respectively, which was blocked by an M3R-selective antagonist. Our data therefore indicate that cholinergic signalling via the M3R is essential for optimal Th1 and Th2 adaptive immunity to infection.

Chlamydia pneumoniae acute liver infection affects hepatic cholesterol and triglyceride metabolism in mice.

Science.gov (United States)

Marangoni, Antonella; Fiorino, Erika; Gilardi, Federica; Aldini, Rita; Scotti, Elena; Nardini, Paola; Foschi, Claudio; Donati, Manuela; Montagnani, Marco; Cevenini, Monica; Franco, Placido; Roda, Aldo; Crestani, Maurizio; Cevenini, Roberto

2015-08-01

Chlamydia pneumoniae has been linked to atherosclerosis, strictly associated with hyperlipidemia. The liver plays a central role in the regulation of lipid metabolism. Since in animal models C. pneumoniae can be found at hepatic level, this study aims to elucidate whether C. pneumoniae infection accelerates atherosclerosis by affecting lipid metabolism. Thirty Balb/c mice were challenged intra-peritoneally with C. pneumoniae elementary bodies and thirty with Chlamydia trachomatis, serovar D. Thirty mice were injected with sucrose-phosphate-glutamate buffer, as negative controls. Seven days after infection, liver samples were examined both for presence of chlamydia and expression of genes involved in inflammation and lipid metabolism. C. pneumoniae was isolated from 26 liver homogenates, whereas C. trachomatis was never re-cultivated (P triglycerides levels compared both with negative controls (P metabolism. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

[Construction of the eukaryotic recombinant vector and expression of the outer membrane protein LipL32 gene from Leptospira serovar Lai].

Science.gov (United States)

Huang, Bi; Bao, Lang; Zhong, Qi; Shang, Zheng-ling; Zhang, Hui-dong; Zhang, Ying

2008-02-01

To construct the eukaryotic experssion vector of LipL32 gene from Leptospira serovar Lai and express the recombinant plasmid in COS-7 cell. The LipL32 gene was amplified from Leptospira strain 017 genomic DNA by PCR and cloned into pcDNA3.1, through restriction nuclease enzyme digestion. Then the recombinant plasmid was transformed into E.coli DH5alpha. After identified by nuclease digestion, PCR and sequencing analysis, the recombinant vector was transfected into COS-7 cell with lipsome. The expression of the target gene was detected by RT-PCR and Western blot. The eukaryotic experssion vector pcDNA3.1-LipL32 was successfully constructed and stably expressed in COS-7 cell. The eukaryotic recombinant vector of outer membrane protein LipL32 gene from Leptospira serovar Lai can be expressed in mammalian cell, which provides an experimental basis for the application of the Leptospira DNA vaccine.

Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections.

Science.gov (United States)

Aiyar, Ashok; Quayle, Alison J; Buckner, Lyndsey R; Sherchand, Shardulendra P; Chang, Theresa L; Zea, Arnold H; Martin, David H; Belland, Robert J

2014-01-01

The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium's capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxgenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C. trachomatis.

Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections

Directory of Open Access Journals (Sweden)

Ashok eAiyar

2014-06-01

Full Text Available The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium’s capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxygenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C

Protein and antigen profiles of Leptospira interrogans serovar Hardjo Perfil proteico e antigênico da Leptospira interrogans sorovariedade Hardjo

Directory of Open Access Journals (Sweden)

Bárbara Nobre Lafetá

2009-12-01

Full Text Available The protein profile of the outer membrane of Leptospira interrogans serovar Hardjo subtype hardjoprajitno associated with the bovine natural immune response was investigated. The outer membrane proteins were extracted utilizing Triton X114 and precipitated with acetone. The protein sample was then resolved by SDS-PAGE and reacted in western blot against sera from a hyperimmune rabbit and from naturally infected bovines. In silver stained gels, 14 protein bands were observed, among which four proteins, with 22, 29, 47 and 63kDa, appeared as major constituents. Western blot tests with hyperimmune rabbit antiserum detected bands corresponding to proteins with 35; 27; 24; 21; 17 and 14kDa, while 32kDa and 45kDa proteins were the most immunoreactive with sera from naturally infected bovines.Estudou-se o perfil proteico da membrana externa da Leptospira interrogans sorovariedade Hardjo, amostra hardjoprajitno, associado à resposta imune natural de bovinos infectados. Foram utilizados Triton X114 para a extração das proteínas de membrana externa e acetona para precipitá-las. As proteínas extraídas foram analisadas por SDS-PAGE e western blot contra soro de coelhos hiperimunes e de bovinos naturalmente infectados. Em géis corados com nitrato de prata, 14 bandas proteicas foram identificadas, e quatro dessas bandas, com 22, 29, 47 e 63kDa, foram as mais proeminentes. Os western blots com soro hiperimune de coelho detectaram bandas correspondentes a proteínas com pesos moleculares de 35, 27, 24, 21, 17 e 14kDa, e bandas de 32 e 45kDa destacaram-se nos testes com soros de bovinos naturalmente infectados.

Multilocus Sequence Typing of the Clinical Isolates of Salmonella Enterica Serovar Typhimurium in Tehran Hospitals

Directory of Open Access Journals (Sweden)

Reza Ranjbar

2017-09-01

Full Text Available Background: Salmonella enterica serovar Typhimurium is one of the most important serovars of Salmonella enterica and is associated with human salmonellosis worldwide. Many epidemiological studies have focused on the characteristics of Salmonella Typhimurium in many countries as well as in Asia. This study was conducted to investigate the genetic characteristics of Salmonella Typhimurium using multilocus sequence typing (MLST. Methods: Clinical samples (urine, blood, and stool were collected from patients, who were admitted to 2 hospitals in Tehran between April and September, 2015. Salmonella Typhimurium strains were identified by conventional standard biochemical and serological testing. The antibiotic susceptibility patterns of the Salmonella Typhimurium isolates against 16 antibiotics was determined using the disk diffusion assay. The clonal relationship between the strains of Salmonella Typhimurium was analyzed using MLST. Results: Among the 68 Salmonella isolates, 31% (n=21 were Salmonella Typhimurium. Of the total 21 Salmonella Typhimurium isolates, 76% (n=16 were multidrug-resistant and showed resistance to 3 or more antibiotic families. The Salmonella Typhimurium isolates were assigned to 2 sequence types: ST19 and ST328. ST19 was more common (86%. Both sequence types were further assigned to 1 eBURST group. Conclusion: This is the first study of its kind in Iran to determine the sequence types of the clinical isolates of Salmonella Typhimurium in Tehran hospitals using MLST. ST19 was detected as the major sequence type of Salmonella Typhimurium.

Molecular characterization of Salmonella enterica serovar 4,[5],12:i:- DT193 ASSuT strains from two outbreaks in Italy

DEFF Research Database (Denmark)

Barco, Lisa; Ramon, Elena; Cortini, Enzo

2014-01-01

Abstract Salmonella enterica subsp. enterica serovar 4,[5],12:i:- DT193 is recognized as an emerging monophasic variant of Salmonella Typhimurium in many European countries. Resistance to ampicillin, streptomycin, sulphonamides, and tetracycline (R-type ASSuT) is described as one of the most comm...

Effects of interferon gamma on Chlamydia trachomatis serovar A and L2 protein expression investigated by two-dimensional gel electrophoresis

DEFF Research Database (Denmark)

Shaw, A; Christiansen, Gunna; Birkelund, Svend

1999-01-01

]methionine and two-dimensional gel electrophoresis with immobilized pH gradients in order to investigate changes in the protein expression of C. trachomatis serovar A and L2 caused by treatment with IFN-gamma. In contrast to what was observed in C. trachomatis L2, our results showed that, in C. trachomatis A, down...

Effect of dietary addition of nitrate on growth, salivary and gastric function, immune response, and excretion of Salmonella enterica serovar Typhimurium, in weaning pigs challenged with this microbe strain

Directory of Open Access Journals (Sweden)

M. Mazzoni

2010-04-01

Full Text Available Two dietary additions of nitrate (15 mg/kg or 150 mg/kg, supplied by potassium salt were tested in a total 96 weaning pigs challenged or not with Salmonella enterica serovar typhimurium (ST. The oral challenge was done on d 5 and pigs were sacrificed on d 7 or d 25. The effect of challenge never interacted significantly with the dietary treatment. Feed intake, growth, body temperature, salivary excretion, and faecal excretion of ST and gastric function were not affected by the nitrate supplementation. With nitrate additions, total IgA in blood serum tended to be higher before and after the challenge (P<0.10. Nitrite in saliva – but not nitrate – increased with the increasing supplementation at d 5, but not at d 19. The nitrate additions did not negatively affect the weaning performance, but also did not contrast the effect of ST infection.

Salmonella Intracellular Lifestyles and Their Impact on Host-to-Host Transmission.

Science.gov (United States)

Pucciarelli, M Graciela; García-Del Portillo, Francisco

2017-07-01

More than a century ago, infections by Salmonella were already associated with foodborne enteric diseases with high morbidity in humans and cattle. Intestinal inflammation and diarrhea are hallmarks of infections caused by nontyphoidal Salmonella serovars, and these pathologies facilitate pathogen transmission to the environment. In those early times, physicians and microbiologists also realized that typhoid and paratyphoid fever caused by some Salmonella serovars could be transmitted by "carriers," individuals outwardly healthy or at most suffering from some minor chronic complaint. In his pioneering study of the nontyphoidal serovar Typhimurium in 1967, Takeuchi published the first images of intracellular bacteria enclosed by membrane-bound vacuoles in the initial stages of the intestinal epithelium penetration. These compartments, called Salmonella -containing vacuoles, are highly dynamic phagosomes with differing biogenesis depending on the host cell type. Single-cell studies involving real-time imaging and gene expression profiling, together with new approaches based on genetic reporters sensitive to growth rate, have uncovered unprecedented heterogeneous responses in intracellular bacteria. Subpopulations of intracellular bacteria displaying fast, reduced, or no growth, as well as cytosolic and intravacuolar bacteria, have been reported in both in vitro and in vivo infection models. Recent investigations, most of them focused on the serovar Typhimurium, point to the selection of persisting bacteria inside macrophages or following an autophagy attack in fibroblasts. Here, we discuss these heterogeneous intracellular lifestyles and speculate on how these disparate behaviors may impact host-to-host transmissibility of Salmonella serovars.

Salmonella infection inhibits intestinal biotin transport: cellular and molecular mechanisms.

Science.gov (United States)

Ghosal, Abhisek; Jellbauer, Stefan; Kapadia, Rubina; Raffatellu, Manuela; Said, Hamid M

2015-07-15

Infection with the nontyphoidal Salmonella is a common cause of food-borne disease that leads to acute gastroenteritis/diarrhea. Severe/prolonged cases of Salmonella infection could also impact host nutritional status, but little is known about its effect on intestinal absorption of vitamins, including biotin. We examined the effect of Salmonella enterica serovar Typhimurium (S. typhimurium) infection on intestinal biotin uptake using in vivo (streptomycin-pretreated mice) and in vitro [mouse (YAMC) and human (NCM460) colonic epithelial cells, and human intestinal epithelial Caco-2 cells] models. The results showed that infecting mice with wild-type S. typhimurium, but not with its nonpathogenic isogenic invA spiB mutant, leads to a significant inhibition in jejunal/colonic biotin uptake and in level of expression of the biotin transporter, sodium-dependent multivitamin transporter. In contrast, infecting YAMC, NCM460, and Caco-2 cells with S. typhimurium did not affect biotin uptake. These findings suggest that the effect of S. typhimurium infection is indirect and is likely mediated by proinflammatory cytokines, the levels of which were markedly induced in the intestine of S. typhimurium-infected mice. Consistent with this hypothesis, exposure of NCM460 cells to the proinflammatory cytokines TNF-α and IFN-γ led to a significant inhibition of biotin uptake, sodium-dependent multivitamin transporter expression, and activity of the SLC5A6 promoter. The latter effects appear to be mediated, at least in part, via the NF-κB signaling pathway. These results demonstrate that S. typhimurium infection inhibits intestinal biotin uptake, and that the inhibition is mediated via the action of proinflammatory cytokines.

Differential recognition of the multiple banded antigen isoforms across Ureaplasma parvum and Ureaplasma urealyticum species by monoclonal antibodies.

Science.gov (United States)

Aboklaish, Ali F; Ahmed, Shatha; McAllister, Douglas; Cassell, Gail; Zheng, Xiaotian T; Spiller, Owen B

2016-08-01

Two separate species of Ureaplasma have been identified that infect humans: Ureaplasma parvum and Ureaplasma urealyticum. Most notably, these bacteria lack a cell wall and are the leading infectious organism associated with infection-related induction of preterm birth. Fourteen separate representative prototype bacterial strains, called serovars, are largely differentiated by the sequence of repeating units in the C-terminus of the major surface protein: multiple-banded antigen (MBA). Monoclonal antibodies that recognise single or small groups of serovars have been previously reported, but these reagents remain sequestered in individual research laboratories. Here we characterise a panel of commercially available monoclonal antibodies raised against the MBA and describe the first monoclonal antibody that cross-reacts by immunoblot with all serovars of U. parvum and U. urealyticum species. We also describe a recombinant MBA expressed by Escherichia coli which facilitated further characterisation by immunoblot and demonstrate immunohistochemistry of paraffin-embedded antigens. Immunoblot reactivity was validated against well characterised previously published monoclonal antibodies and individual commercial antibodies were found to recognise all U. parvum strains, only serovars 3 and 14 or only serovars 1 and 6, or all strains belonging to U. parvum and U. urealyticum. MBA mass was highly variable between strains, consistent with variation in the number of C-terminal repeats between strains. Antibody characterisation will enable future investigations to correlate severity of pathogenicity to MBA isoform number or mass, in addition to development of antibody-based diagnostics that will detect infection by all Ureaplasma species or alternately be able to differentiate between U. parvum, U. urealyticum or mixed infections. Copyright © 2016 Elsevier B.V. All rights reserved.

Validation of Baking To Control Salmonella Serovars in Hamburger Bun Manufacturing, and Evaluation of Enterococcus faecium ATCC 8459 and Saccharomyces cerevisiae as Nonpathogenic Surrogate Indicators.

Science.gov (United States)

Channaiah, Lakshmikantha H; Holmgren, Elizabeth S; Michael, Minto; Sevart, Nicholas J; Milke, Donka; Schwan, Carla L; Krug, Matthew; Wilder, Amanda; Phebus, Randall K; Thippareddi, Harshavardhan; Milliken, George

2016-04-01

This study was conducted to validate a simulated commercial baking process for hamburger buns to destroy Salmonella serovars and to determine the appropriateness of using nonpathogenic surrogates (Enterococcus faecium ATCC 8459 or Saccharomyces cerevisiae) for in-plant process validation studies. Wheat flour was inoculated (∼6 log CFU/g) with three Salmonella serovars (Typhimurium, Newport, or Senftenberg 775W) or with E. faecium. Dough was formed, proofed, and baked to mimic commercial manufacturing conditions. Buns were baked for up to 13 min in a conventional oven (218.3°C), with internal crumb temperature increasing to ∼100°C during the first 8 min of baking and remaining at this temperature until removal from the oven. Salmonella and E. faecium populations were undetectable by enrichment (>6-log CFU/g reductions) after 9.0 and 11.5 min of baking, respectively, and ≥5-log-cycle reductions were achieved by 6.0 and 7.75 min, respectively. D-values of Salmonella (three-serovar cocktail) and E. faecium 8459 in dough were 28.64 and 133.33, 7.61 and 55.67, and 3.14 and 14.72 min at 55, 58, and 61°C, respectively, whereas D-values of S. cerevisiae were 18.73, 5.67, and 1.03 min at 52, 55, and 58°C, respectivly. The z-values of Salmonella, E. faecium, and S. cerevisiae were 6.58, 6.25, and 4.74°C, respectively. A high level of thermal lethality was observed for baking of typical hamburger bun dough, resulting in rapid elimination of high levels of the three-strain Salmonella cocktail; however, the lethality and microbial destruction kinetics should not be extrapolated to other bakery products without further research. E. faecium demonstrated greater thermal resistance compared with Salmonella during bun baking and could serve as a conservative surrogate to validate thermal process lethality in commercial bun baking operations. Low thermal tolerance of S. cerevisiae relative to Salmonella serovars limits its usefulness as a surrogate for process validations.

Increased colon cancer risk after severe Salmonella infection.

Directory of Open Access Journals (Sweden)

Lapo Mughini-Gras

Full Text Available Colon cancer constitutes one of the most frequent malignancies. Previous studies showed that Salmonella manipulates host cell signaling pathways and that Salmonella Typhimurium infection facilitates colon cancer development in genetically predisposed mice. This epidemiological study examined whether severe Salmonella infection, usually acquired from contaminated food, is associated with increased colon cancer risk in humans.We performed a nationwide registry-based study to assess colon cancer risk after diagnosed Salmonella infection. National infectious disease surveillance records (1999-2015 for Dutch residents aged ≥20 years when diagnosed with salmonellosis (n = 14,264 were linked to the Netherlands Cancer Registry. Salmonella-infected patients were laboratory-confirmed under medical consultation after 1-2 weeks of illness. These datasets also contained information on Salmonella serovar and type of infection. Colon cancer risk (overall and per colon subsite among patients with a diagnosed Salmonella infection was compared with expected colon cancer risk in the general population. Data from the nationwide registry of histo- and cytopathology (PALGA and Statistics Netherlands (CBS allowed assessing potential effects of age, gender, latency, socioeconomic status, genetic predisposition, inflammatory bowel disease (IBD, and tumor features. We found that compared to the general population, colon cancer risk was significantly increased (standardized incidence ratio [SIR] 1.54; 95%CI 1.09-2.10 among patients with Salmonella infection diagnosed <60 years of age. Such increased risk concerned specifically the ascending/transverse colon (SIR 2.12; 95%CI 1.38-3.09 after S. Enteritidis infection (SIR 2.97; 95%CI 1.73-4.76. Salmonellosis occurred more frequently among colon cancer patients with pre-infectious IBD, a known risk factor for colon cancer. Colon tumors of patients with a history of Salmonella infection were mostly of low grade

Increased colon cancer risk after severe Salmonella infection

Science.gov (United States)

Mooij, Sofie; Neefjes-Borst, E. Andra; van Pelt, Wilfrid; Neefjes, Jacques

2018-01-01

Background Colon cancer constitutes one of the most frequent malignancies. Previous studies showed that Salmonella manipulates host cell signaling pathways and that Salmonella Typhimurium infection facilitates colon cancer development in genetically predisposed mice. This epidemiological study examined whether severe Salmonella infection, usually acquired from contaminated food, is associated with increased colon cancer risk in humans. Methods and findings We performed a nationwide registry-based study to assess colon cancer risk after diagnosed Salmonella infection. National infectious disease surveillance records (1999–2015) for Dutch residents aged ≥20 years when diagnosed with salmonellosis (n = 14,264) were linked to the Netherlands Cancer Registry. Salmonella-infected patients were laboratory-confirmed under medical consultation after 1–2 weeks of illness. These datasets also contained information on Salmonella serovar and type of infection. Colon cancer risk (overall and per colon subsite) among patients with a diagnosed Salmonella infection was compared with expected colon cancer risk in the general population. Data from the nationwide registry of histo- and cytopathology (PALGA) and Statistics Netherlands (CBS) allowed assessing potential effects of age, gender, latency, socioeconomic status, genetic predisposition, inflammatory bowel disease (IBD), and tumor features. We found that compared to the general population, colon cancer risk was significantly increased (standardized incidence ratio [SIR] 1.54; 95%CI 1.09–2.10) among patients with Salmonella infection diagnosed transverse colon (SIR 2.12; 95%CI 1.38–3.09) after S. Enteritidis infection (SIR 2.97; 95%CI 1.73–4.76). Salmonellosis occurred more frequently among colon cancer patients with pre-infectious IBD, a known risk factor for colon cancer. Colon tumors of patients with a history of Salmonella infection were mostly of low grade. Conclusions Patients diagnosed with severe

Evaluation of a novel enzyme-linked immunosorbent assay for detection of antibodies against Salmonella, employing a stable coating of lipopolysaccharide-derived antigens covalently attached to polystyrene microwells

DEFF Research Database (Denmark)

Wiuff, C.; Jauho, E. S.; Stryhn, H.

2000-01-01

to microtiter polystyrene plates by ultraviolet irradiation. Both polysaccharide antigens could be coupled simultaneously to the same microtiter plate. The coated surface was used in indirect ELISA for the determination of serum antibodies from pigs infected with bacteria of the two Salmonella groups and from......Polysaccharides derived from Salmonella typhimurium lipopolysaccharide (LPS) representing the O-antigen factors 1, 4, 5, and 12 and the O-antigen factors 6 and 7 from Salmonella choleraesuis LPS were derivatized with the photoreactive compound anthraquinone and subsequently covalently coupled...

Higher Storage Temperature Causes Greater Salmonella enterica Serovar Typhimurium Internal Penetration of Artificially Contaminated, Commercially Available, Washed Free Range Eggs.

Science.gov (United States)

Whiley, Alice; Fallowfield, Howard; Ross, Kirstin; McEvoy, Vanessa; Whiley, Harriet

2016-07-01

Foodborne salmonellosis is a major public health concern, with contaminated eggs identified as a significant source of infection. In Australia, the most prevalent cause of salmonellosis from eggs is Salmonella enterica subsp. enterica serovar Typhimurium. This study explored the effect of temperature after 1, 7, 14, 21, and 28 days of storage on commercially available washed free range eggs, artificially contaminated with Salmonella Typhimurium on the external surface. At each time point, the external surface of the egg, the crushed eggshell, and the internal egg yolk and albumen were analyzed for Salmonella. After 28 days of storage, 25% of eggs stored at 4°C, 50% of eggs stored at 14°C, and 100% of eggs stored at 23 and 35°C were internally contaminated with Salmonella. After 1 day of storage, more than 50% of all eggs had Salmonella present in the crushed shell after the external surface had been disinfected with ethanol. This is the first study to demonstrate that refrigeration reduced the potential for Salmonella Typhimurium to penetrate the eggshell membrane and internally contaminate table eggs commercially available in Australia. It also suggests that the processes of cracking eggs may be a source of cross-contamination within the kitchen.

Comparison of Methods of Extracting Salmonella enterica Serovar Enteritidis DNA from Environmental Substrates and Quantification of Organisms by Using a General Internal Procedural Control

NARCIS (Netherlands)

Klerks, M.M.; Bruggen, van A.H.C.; Zijlstra, C.; Donnikov, M.; Vos, de R.

2006-01-01

This paper compares five commercially available DNA extraction methods with respect to DNA extraction efficiency of Salmonella enterica serovar Enteritidis from soil, manure, and compost and uses an Escherichia coli strain harboring a plasmid expressing green fluorescent protein as a general

Serological prevalence of leptospirosis in cattle slaughtered in the Zango abattoir in Zaria, Kaduna State, Nigeria

Directory of Open Access Journals (Sweden)

Emmanuel O. Ngbede

2012-06-01

Full Text Available Leptospirosis is an occupational zoonosis caused by pathogenic leptospires. In this study, the presence and prevalence of antibodies specific to Leptospira spp. serovar Hardjo in 142 cattle slaughtered between June and July 2011 was investigated using the enzyme-linked immunosorbent assay (ELISA. Five (3.50% of the 142 cattle sampled were seropositive for antibodies to Leptospira spp. serovar Hardjo. Despite the fact that there was no significant difference (p>0.05 in seropositivity between sexes and between breeds sampled, there was a significant difference (p<0.05 in sero-positivity between the different age groups examined. Leptospirosis is present in cattle slaughtered in the Zango abattoir; butchers and abattoir workers are exposed to infected animals and are at risk of being infected by Leptospira spp. serovar Hardjo.

Cloning, expression, and homology modeling of GroEL protein from Leptospira interrogans serovar autumnalis strain N2.

Science.gov (United States)

Natarajaseenivasan, Kalimuthusamy; Shanmughapriya, Santhanam; Velineni, Sridhar; Artiushin, Sergey C; Timoney, John F

2011-10-01

Leptospirosis is an infectious bacterial disease caused by Leptospira species. In this study, we cloned and sequenced the gene encoding the immunodominant protein GroEL from L. interrogans serovar Autumnalis strain N2, which was isolated from the urine of a patient during an outbreak of leptospirosis in Chennai, India. This groEL gene encodes a protein of 60 kDa with a high degree of homology (99% similarity) to those of other leptospiral serovars. Recombinant GroEL was overexpressed in Escherichia coli. Immunoblot analysis indicated that the sera from confirmed leptospirosis patients showed strong reactivity with the recombinant GroEL while no reactivity was observed with the sera from seronegative control patient. In addition, the 3D structure of GroEL was constructed using chaperonin complex cpn60 from Thermus thermophilus as template and validated. The results indicated a Z-score of -8.35, which is in good agreement with the expected value for a protein. The superposition of the Ca traces of cpn60 structure and predicted structure of leptospiral GroEL indicates good agreement of secondary structure elements with an RMSD value of 1.5 Å. Further study is necessary to evaluate GroEL for serological diagnosis of leptospirosis and for its potential as a vaccine component. Copyright © 2011 Beijing Genomics Institute. Published by Elsevier Ltd. All rights reserved.

Real-time PCR Detection of Food-borne Pathogenic Salmonella spp

DEFF Research Database (Denmark)

Malorny, B.; Mäde, D.; Löfström, Charlotta

2013-01-01

Infections by Salmonella enterica are a significant public health concern worldwide. Salmonellae form a complex group of bacteria consisting of two species, six subspecies and more than 2500 serovars (serotypes). Mainly through ingestion of contaminated food or feed, they cause self-limiting gast......Infections by Salmonella enterica are a significant public health concern worldwide. Salmonellae form a complex group of bacteria consisting of two species, six subspecies and more than 2500 serovars (serotypes). Mainly through ingestion of contaminated food or feed, they cause self...

Regulation of the Two-Component Regulator CpxR on Aminoglycosides and β-lactams Resistance in Salmonella enterica Serovar Typhimurium

Directory of Open Access Journals (Sweden)

Hui eHuang

2016-04-01

Full Text Available The two-component signal transduction system CpxAR is especially widespread in Gram-negative bacteria. It has been reported that CpxAR contributes to the multidrug resistance (MDR in Escherichia coli. CpxR is a response regulator in the two-component CpxAR system. The aim of this study was to explore the role of cpxR in the MDR of S. enterica serovar Typhimurium. The minimal inhibitory concentrations (MICs of various antibiotics commonly used in veterinary medicine for strains JS (a multidrug-susceptible standard strain of S. enterica serovar Typhimurium, JS△cpxR, JS△cpxR/pcpxR, JS△cpxR/pcpxR＊, JS△cpxR△acrB, JS△cpxR△acrB/pcpxR, JS△cpxR△acrB/pcpxR＊, 9 S. enterica serovar Typhimurium isolates (SH1–9, and SH1–9△cpxR were determined by the 2-fold broth microdilution method. The relative mRNA expression levels of ompF, ompC, ompW, ompD, tolC, acrB, acrD, acrF, mdtA, marA, and soxS in strains JS, JS△cpxR, and JS△cpxR/pcpxR were detected by real-time PCR. The results showed 2- to 4-fold decreases in the MICs of amikacin (AMK, gentamycin (GEN, apramycin (APR, neomycin (NEO, ceftriaxone (CRO, ceftiofur (CEF, and cefquinome (CEQ for strain JS△cpxR, as compared to those for the parental strain JS. Likewise, SH1–9△cpxR were found to have 2- to 8-fold reduction in resistance to the above antibiotics, except for NEO, as compared to their parental strains SH1–9. Furthermore, 2- to 4-fold further decreases in the MICs of AMK, GEN, APR, and CEF for strain JS△cpxR△acrB were observed, as compared to those for strain JS△acrB. In addition, CpxR overproduction in strain JS△cpxR led to significant decreases in the mRNA expression levels of ompF, ompC, ompW, ompD, tolC, acrB, marA, and soxS, and significant increases in those of stm3031 and stm1530. Notably, after all strains were induced simultaneously by GEN to the 15th passage at subinhibitory concentrations, strain JS△cpxR/pcpxR showed significant increases in m

Characterization of a linear epitope on Chlamydia trachomatis serovar L2 DnaK-like protein

DEFF Research Database (Denmark)

Ozkokmen, D; Birkelund, Svend; Christiansen, Gunna

1994-01-01

A cytoplasmic 75-kDa immunogen from Chlamydia trachomatis serovar L2 has previously been characterized as being similar to the Escherichia coli heat shock protein DnaK. We have localized a linear epitope for one monoclonal antibody specific for C. trachomatis DnaK. By use of a recombinant DNA...... technique, the epitope was limited to 14 amino acids. With synthetic peptides, the epitope was further limited to eight amino acids. Six of these amino acids are conserved in bovine HSP70, which has a known three-dimensional structure. The amino acid sequence homologous to the epitope is located in a linear...

Genomic and Phenotypic Analyses Reveal the Emergence of an Atypical Salmonella enterica Serovar Senftenberg Variant in China

KAUST Repository

Abd El Ghany, Moataz

2016-05-25

Human infections with Salmonella enterica subspecies enterica serovar Senftenberg are often associated with exposure to poultry flocks, farm environments, or contaminated food. The recent emergence of multidrug-resistant isolates has raised public health concerns. In this study, comparative genomics and phenotypic analysis were used to characterize 14 Salmonella Senftenberg clinical isolates recovered from multiple outbreaks in Shenzhen and Shanghai, China, between 2002 and 2011. Single-nucleotide polymorphism analyses identified two phylogenetically distinct clades of S. Senftenberg, designated SC1 and SC2, harboring variations in Salmonella pathogenicity island 1 (SPI-1) and SPI-2 and exhibiting distinct biochemical and phenotypic signatures. Although the two variants shared the same serotype, the SC2 isolates of sequence type 14 (ST14) harbored intact SPI-1 and -2 and hence were characterized by possessing efficient invasion capabilities. In contrast, the SC1 isolates had structural deletion patterns in both SPI-1 and -2 that correlated with an impaired capacity to invade cultured human cells and also the year of their isolation. These atypical SC1 isolates also lacked the capacity to produce hydrogen sulfide. These findings highlight the emergence of atypical Salmonella Senftenberg variants in China and provide genetic validation that variants lacking SPI-1 and regions of SPI-2, which leads to impaired invasion capacity, can still cause clinical disease. These data have identified an emerging public health concern and highlight the need to strengthen surveillance to detect the prevalence and transmission of nontyphoidal Salmonella species.

Some putative prebiotics increase the severity of Salmonella enterica serovar Typhimurium infection in mice

Directory of Open Access Journals (Sweden)

Lahtinen Sampo

2009-01-01

Full Text Available Abstract Background Prebiotics are non-digestible food ingredients believed to beneficially affect host health by selectively stimulating the growth of the beneficial bacteria residing in the gut. Such beneficial bacteria have been reported to protect against pathogenic infections. However, contradicting results on prevention of Salmonella infections with prebiotics have been published. The aim of the present study was to examine whether S. Typhimurium SL1344 infection in mice could be prevented by administration of dietary carbohydrates with different structures and digestibility profiles. BALB/c mice were fed a diet containing 10% of either of the following carbohydrates: inulin, fructo-oligosaccharide, xylo-oligosaccharide, galacto-oligosaccharide, apple pectin, polydextrose or beta-glucan for three weeks prior to oral Salmonella challenge (107 CFU and compared to mice fed a cornstarch-based control diet. Results The mice fed with diets containing fructo-oligosaccharide (FOS or xylo-oligosaccharide (XOS had significantly higher (P < 0.01 and P < 0.05 numbers of S. Typhimurium SL1344 in liver, spleen and mesenteric lymph nodes when compared to the mice fed with the cornstarch-based control diet. Significantly increased amounts (P < 0.01 of Salmonella were detected in ileal and fecal contents of mice fed with diets supplemented with apple pectin, however these mice did not show significantly higher numbers of S. Typhimyrium in liver, spleen and lymph nodes than animals from the control group (P < 0.20. The acute-phase protein haptoglobin was a good marker for translocation of S. Typhimurium in mice. In accordance with the increased counts of Salmonella in the organs, serum concentrations of haptoglobin were significantly increased in the mice fed with FOS or XOS (P < 0.001. Caecum weight was increased in the mice fed with FOS (P < 0.01, XOS (P < 0.01, or polydextrose (P < 0.001, and caecal pH was reduced in the mice fed with polydextrose (P < 0

Tissue dyslipidemia in salmonella-infected rats treated with amoxillin and pefloxacin

Directory of Open Access Journals (Sweden)

Rotimi Solomon O

2012-11-01

Full Text Available Abstract Background This study investigated the effects of salmonella infection and its chemotherapy on lipid metabolism in tissues of rats infected orally with Salmonella typhimurium and treated intraperitoneally with pefloxacin and amoxillin. Methods Animals were infected with Salmonella enterica serovar Typhimurium strain TA 98. After salmonellosis was confirmed, they were divided into 7 groups of 5 animals each. While one group served as infected control group, three groups were treated with amoxillin (7.14 mg/kg body weight, 8 hourly and the remaining three groups with pefloxacin (5.71mg/kg body weight, 12 hourly for 5 and 10 days respectively. Uninfected control animals received 0.1ml of vehicle. Rats were sacrificed 24h after 5 and 10 days of antibiotic treatment and 5 days after discontinuation of antibiotic treatment. Their corresponding controls were also sacrificed at the same time point. Blood and tissue lipids were then evaluated. Results Salmonella infection resulted in dyslipidemia characterised by increased concentrations of free fatty acids (FFA in plasma and erythrocyte, as well as enhanced cholesterogenesis, hypertriglyceridemia and phospholipidosis in plasma, low density lipoprotein-very low density lipoprotein (LDL-VLDL, erythrocytes, erythrocyte ghost and the organs. The antibiotics reversed the dyslipidemia but not totally. A significant correlation was observed between fecal bacterial load and plasma cholesterol (r=0.456, p Conclusion The findings of this study suggest that salmonella infection in rats and its therapy with pefloxacin and amoxillin perturb lipid metabolism and this perturbation is characterised by cholesterogenesis.

A highly sensitive, multiplex broad-spectrum PCR-DNA-enzyme immunoassay and reverse hybridization assay for rapid detection and identification of Chlamydia trachomatis serovars.

NARCIS (Netherlands)

Quint, K.D.; Doorn, L.J. van; Kleter, B.; Koning, M.N. de; Munckhof, H.A. van den; Morre, S.A.; Harmsel, B. ter; Weiderpass, E.; Harbers, G.; Melchers, W.J.G.; Quint, W.G.V.

2007-01-01

Chlamydia trachomatis (Ct) comprises distinct serogroups and serovars. The present study evaluates a novel Ct amplification, detection, and genotyping method (Ct-DT assay). The Ct-DT amplification step is a multiplex broad-spectrum PCR for the cryptic plasmid and the VD2-region of ompl. The Ct-DT

Comprehensive identification of Salmonella enterica serovar typhimurium genes required for infection of BALB/c mice.

Directory of Open Access Journals (Sweden)

Roy R Chaudhuri

2009-07-01

Full Text Available Genes required for infection of mice by Salmonella Typhimurium can be identified by the interrogation of random transposon mutant libraries for mutants that cannot survive in vivo. Inactivation of such genes produces attenuated S. Typhimurium strains that have potential for use as live attenuated vaccines. A quantitative screen, Transposon Mediated Differential Hybridisation (TMDH, has been developed that identifies those members of a large library of transposon mutants that are attenuated. TMDH employs custom transposons with outward-facing T7 and SP6 promoters. Fluorescently-labelled transcripts from the promoters are hybridised to whole-genome tiling microarrays, to allow the position of the transposon insertions to be determined. Comparison of microarray data from the mutant library grown in vitro (input with equivalent data produced after passage of the library through mice (output enables an attenuation score to be determined for each transposon mutant. These scores are significantly correlated with bacterial counts obtained during infection of mice using mutants with individual defined deletions of the same genes. Defined deletion mutants of several novel targets identified in the TMDH screen are effective live vaccines.

Genome and Transcriptome Adaptation Accompanying Emergence of the Definitive Type 2 Host-Restricted Salmonella enterica Serovar Typhimurium Pathovar

OpenAIRE

Kingsley, Robert A.; Kay, Sally; Connor, Thomas; Barquist, Lars; Sait, Leanne; Holt, Kathryn E.; Sivaraman, Karthi; Wileman, Thomas; Goulding, David; Clare, Simon; Hale, Christine; Seshasayee, Aswin; Harris, Simon; Thomson, Nicholas R.; Gardner, Paul

2013-01-01

Salmonella enterica serovar Typhimurium definitive type 2 (DT2) is host restricted to Columba livia (rock or feral pigeon) but is also closely related to S. Typhimurium isolates that circulate in livestock and cause a zoonosis characterized by gastroenteritis in humans. DT2 isolates formed a distinct phylogenetic cluster within S. Typhimurium based on whole-genome-sequence polymorphisms. Comparative genome analysis of DT2 94-213 and S. Typhimurium SL1344, DT104, and D23580 identified few diff...

Identification of lymphogranuloma venereum-associated Chlamydia trachomatis serovars by fluorescence in situ hybridisation--a proof-of-principle analysis.

Science.gov (United States)

Frickmann, Hagen; Essig, Andreas; Poppert, Sven

2014-04-01

We describe a proof-of-principle evaluation of a fluorescence in situ hybridisation (FISH) procedure to identify Chlamydia trachomatis serovars L1-L3, the causative agents of lymphogranuloma venereum, in cell cultures based on newly designed DNA probes. Rapid and easy-to-perform FISH could facilitate the diagnosis of lymphogranuloma venereum without nucleic acid amplification or serotyping, but requires broader evaluation studies, for example, in tropical high-endemicity regions. © 2014 John Wiley & Sons Ltd.

Use of saprophytic leptospira strains in the serodiagnosis of experimental leptospirosis in guinea-pigs (Cavia sp

Directory of Open Access Journals (Sweden)

Raul J. S. Girio

1988-04-01

Full Text Available The efficiency of four Leptospira biflexa strains (Buenos Aires, Patoc 1, Rufino and São Paulo as single antigen in the serodiagnosis in guinea-pigs experimentally infected with seven Leptospira interrogans serovars (canicola, grippotyphosa, hardjo, icterohaemorrhagiae, pomona, tarassovi and wolffi was evaluated by the microscopic agglutination test. The four saprophytic strains were not able to reveal antibody titres in sera of guinea-pigs experimentally infected with Leptospira interrogans. Serological cross-reactions were observed between strains Patoc 1 and São Paulo and between serovars wolffi and hardjo.

Identification of Transcriptional Modules and Key Genes in Chickens Infected with Salmonella enterica Serovar Pullorum Using Integrated Coexpression Analyses

Directory of Open Access Journals (Sweden)

Bao-Hong Liu

2017-01-01

Full Text Available Salmonella enterica Pullorum is one of the leading causes of mortality in poultry. Understanding the molecular response in chickens in response to the infection by S. enterica is important in revealing the mechanisms of pathogenesis and disease progress. There have been studies on identifying genes associated with Salmonella infection by differential expression analysis, but the relationships among regulated genes have not been investigated. In this study, we employed weighted gene coexpression network analysis (WGCNA and differential coexpression analysis (DCEA to identify coexpression modules by exploring microarray data derived from chicken splenic tissues in response to the S. enterica infection. A total of 19 modules from 13,538 genes were associated with the Jak-STAT signaling pathway, the extracellular matrix, cytoskeleton organization, the regulation of the actin cytoskeleton, G-protein coupled receptor activity, Toll-like receptor signaling pathways, and immune system processes; among them, 14 differentially coexpressed modules (DCMs and 2,856 differentially coexpressed genes (DCGs were identified. The global expression of module genes between infected and uninfected chickens showed slight differences but considerable changes for global coexpression. Furthermore, DCGs were consistently linked to the hubs of the modules. These results will help prioritize candidate genes for future studies of Salmonella infection.

Leptospira santorosai serovar shermani detergent extract induces an increase in fibronectin production through a toll-like receptor 2-mediated pathway

OpenAIRE

Tian, Ya-Chung; Hung, Cheng-Chieh; Li, Yi-Jung; Chen, Yung-Chang; Chang, Ming-Yang; Yen, Tzung-Hai; Hsu, Hsiang-Hao; Wu, Mai-Szu; Phillips, Aled Owain; Yang, Chih-Wei

2011-01-01

Leptospirosis can activate inflammatory responses through Toll-like receptors (TLRs) and may cause renal tubulointerstitial fibrosis characterized by the accumulation of extracellular matrix (ECM). We have previously demonstrated that Leptospira santorosai serovar Shermani detergent extract stimulates ECM accumulation in vitro. The aim of this study was to examine the mechanistic basis of these previous observations and, in particular, to examine the potential involvement of TLRs. The additio...

Expression and crystallization of SeDsbA, SeDsbL and SeSrgA from Salmonella enterica serovar Typhimurium

International Nuclear Information System (INIS)

Jarrott, R.; Shouldice, S. R.; Gunčar, G.; Totsika, M.; Schembri, M. A.; Heras, B.

2010-01-01

The cloning, purification, crystallization and preliminary crystallographic studies of three DsbA-like proteins present in S. enterica serovar Typhimurium, SeDsbA, SeDsbL and SeSrgA, are reported. Pathogens require protein-folding enzymes to produce functional virulence determinants. These foldases include the Dsb family of proteins, which catalyze oxidative folding in bacteria. Bacterial disulfide catalytic processes have been well characterized in Escherichia coli K-12 and these mechanisms have been extrapolated to other organisms. However, recent research indicates that the K-12 complement of Dsb proteins is not common to all bacteria. Importantly, many pathogenic bacteria have an extended arsenal of Dsb catalysts that is linked to their virulence. To help to elucidate the process of oxidative folding in pathogens containing a wide repertoire of Dsb proteins, Salmonella enterica serovar Typhimurium has been focused on. This Gram-negative bacterium contains three DsbA proteins: SeDsbA, SeDsbL and SeSrgA. Here, the expression, purification, crystallization and preliminary diffraction analysis of these three proteins are reported. SeDsbA, SeDsbL and SeSrgA crystals diffracted to resolution limits of 1.55, 1.57 and 2.6 Å and belonged to space groups P2 1 , P2 1 2 1 2 and C2, respectively

[Expression changes of major outer membrane protein antigens in Leptospira interrogans during infection and its mechanism].

Science.gov (United States)

Zheng, Linli; Ge, Yumei; Hu, Weilin; Yan, Jie

2013-03-01

To determine expression changes of major outer membrane protein(OMP) antigens of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai during infection of human macrophages and its mechanism. OmpR encoding genes and OmpR-related histidine kinase (HK) encoding gene of L.interrogans strain Lai and their functional domains were predicted using bioinformatics technique. mRNA level changes of the leptospiral major OMP-encoding genes before and after infection of human THP-1 macrophages were detected by real-time fluorescence quantitative RT-PCR. Effects of the OmpR-encoding genes and HK-encoding gene on the expression of leptospiral OMPs during infection were determined by HK-peptide antiserum block assay and closantel inhibitive assays. The bioinformatics analysis indicated that LB015 and LB333 were referred to OmpR-encoding genes of the spirochete, while LB014 might act as a OmpR-related HK-encoding gene. After the spirochete infecting THP-1 cells, mRNA levels of leptospiral lipL21, lipL32 and lipL41 genes were rapidly and persistently down-regulated (P Expression levels of L.interrogans strain Lai major OMP antigens present notable changes during infection of human macrophages. There is a group of OmpR-and HK-encoding genes which may play a major role in down-regulation of expression levels of partial OMP antigens during infection.

Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

Directory of Open Access Journals (Sweden)

Peter J Hart

Full Text Available Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

Science.gov (United States)

Hart, Peter J; O'Shaughnessy, Colette M; Siggins, Matthew K; Bobat, Saeeda; Kingsley, Robert A; Goulding, David A; Crump, John A; Reyburn, Hugh; Micoli, Francesca; Dougan, Gordon; Cunningham, Adam F; MacLennan, Calman A

2016-01-01

Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

Proteomic Investigation of the Time Course Responses of RAW 264.7 Macrophages to Infection with Salmonella enterica

Energy Technology Data Exchange (ETDEWEB)

Shi, Liang; Chowdhury, Saiful M.; Smallwood, Heather S.; Yoon, Hyunjin; Mottaz-Brewer, Heather M.; Norbeck, Angela D.; McDermott, Jason E.; Clauss, Therese RW; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

2009-08-01

Macrophages plan important roles in controlling Salmonella-mediated systemic infection. To investigate the responses of macrophages to Salmonella infection, we infected RAW 264.7 macrophages with Salmonella enterica serovar Typhimurium (STM) and then performed a comparative liquid chromatography-tandem mass spectrometry [LC-MS(/MS)]-based proteomics analysis of the infected macrophages. A total of 1006 macrophage and 115 STM proteins were indentified from this study. Most of STM proteins were found at late stage of the time course of infection, consistent with the fact that STM proliferates inside RAW 264.7 macrophages. Majority of the identified macrophage proteins were house keeping-related, including cytoplasmic superoxide dismutase 1 (SOD1), whose peptide abundances were relatively constant during the time course of infection. Compared to those in no infection control, the peptide abundances of 244 macrophage proteins (or 24% of total indentified macrophage proteins) changed considerably after STM infection. The functions of these STM infection-affected macrophage proteins were diverse and ranged from production of antibacterial nitric oxide (i.e., inducible nitric oxide synthase or iNOS) or production of prostaglandin H2 (i.e., prostaglandin-endoperoxide synthase 2, also know as cyclooxygenase-2 or COX-2) to regulation of intracellular traffic (e.g., sorting nexin or SNX 5, 6 and 9), demonstrating a global impact of STM infection on macrophage proteome. Western-blot analysis not only confirmed the LC-MS(/MS) results of SOD1, COX-2 and iNOS, but also revealed that the protein abundances of mitochondrial SOD2 increased after STM infection, indicating an infection-induced oxidative stress in mitochondria.

A Multi-Omic View of Host-Pathogen-Commensal Interplay in Salmonella-Mediated Intestinal Infection

Energy Technology Data Exchange (ETDEWEB)

Kaiser, Brooke LD; Li, Jie; Sanford, James A.; Kim, Young-Mo; Kronewitter, Scott R.; Jones, Marcus B.; Peterson, Christine; Peterson, Scott N.; Frank, Bryan C.; Purvine, Samuel O.; Brown, Joseph N.; Metz, Thomas O.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

2013-06-26

The potential for commensal microorganisms indigenous to a host (the ‘microbiome’ or ‘microbiota’) to alter infection outcome by influencing host-pathogen interplay is largely unknown. We used a multi-omics “systems” approach, incorporating proteomics, metabolomics, glycomics, and metagenomics, to explore the molecular interplay between the murine host, the pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium), and commensal gut microorganisms during intestinal infection with S. Typhimurium. We find proteomic evidence that S. Typhimurium thrives within the infected 129/SvJ mouse gut without antibiotic pre-treatment, inducing inflammation and disrupting the intestinal microbiome (e.g., suppressing Bacteroidetes and Firmicutes while promoting growth of Salmonella and Enterococcus). Alteration of the host microbiome population structure was highly correlated with gut environmental changes, including the accumulation of metabolites normally consumed by commensal microbiota. Finally, the less characterized phase of S. Typhimurium’s lifecycle was investigated, and both proteomic and glycomic evidence suggests S. Typhimurium may take advantage of increased fucose moieties to metabolize fucose while growing in the gut. The application of multiple omics measurements to Salmonella-induced intestinal inflammation provides insights into complex molecular strategies employed during pathogenesis between host, pathogen, and the microbiome.

Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections

Science.gov (United States)

Sjölund-Karlsson, Maria; Gordon, Melita A.; Parry, Christopher M.

2015-01-01

SUMMARY Salmonella enterica infections are common causes of bloodstream infection in low-resource areas, where they may be difficult to distinguish from other febrile illnesses and may be associated with a high case fatality ratio. Microbiologic culture of blood or bone marrow remains the mainstay of laboratory diagnosis. Antimicrobial resistance has emerged in Salmonella enterica, initially to the traditional first-line drugs chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole. Decreased fluoroquinolone susceptibility and then fluoroquinolone resistance have developed in association with chromosomal mutations in the quinolone resistance-determining region of genes encoding DNA gyrase and topoisomerase IV and also by plasmid-mediated resistance mechanisms. Resistance to extended-spectrum cephalosporins has occurred more often in nontyphoidal than in typhoidal Salmonella strains. Azithromycin is effective for the management of uncomplicated typhoid fever and may serve as an alternative oral drug in areas where fluoroquinolone resistance is common. In 2013, CLSI lowered the ciprofloxacin susceptibility breakpoints to account for accumulating clinical, microbiologic, and pharmacokinetic-pharmacodynamic data suggesting that revision was needed for contemporary invasive Salmonella infections. Newly established CLSI guidelines for azithromycin and Salmonella enterica serovar Typhi were published in CLSI document M100 in 2015. PMID:26180063

High-resolution melt PCR analysis for genotyping of Ureaplasma parvum isolates directly from clinical samples.

Science.gov (United States)

Payne, Matthew S; Tabone, Tania; Kemp, Matthew W; Keelan, Jeffrey A; Spiller, O Brad; Newnham, John P

2014-02-01

Ureaplasma sp. infection in neonates and adults underlies a variety of disease pathologies. Of the two human Ureaplasma spp., Ureaplasma parvum is clinically the most common. We have developed a high-resolution melt (HRM) PCR assay for the differentiation of the four serovars of U. parvum in a single step. Currently U. parvum strains are separated into four serovars by sequencing the promoter and coding region of the multiple-banded antigen (MBA) gene. We designed primers to conserved sequences within this region for PCR amplification and HRM analysis to generate reproducible and distinct melt profiles that distinguish clonal representatives of serovars 1, 3, 6, and 14. Furthermore, our HRM PCR assay could classify DNA extracted from 74 known (MBA-sequenced) test strains with 100% accuracy. Importantly, HRM PCR was also able to identify U. parvum serovars directly from 16 clinical swabs. HRM PCR performed with DNA consisting of mixtures of combined known serovars yielded profiles that were easily distinguished from those for single-serovar controls. These profiles mirrored clinical samples that contained mixed serovars. Unfortunately, melt curve analysis software is not yet robust enough to identify the composition of mixed serovar samples, only that more than one serovar is present. HRM PCR provides a single-step, rapid, cost-effective means to differentiate the four serovars of U. parvum that did not amplify any of the known 10 serovars of Ureaplasma urealyticum tested in parallel. Choice of reaction reagents was found to be crucial to allow sufficient sensitivity to differentiate U. parvum serovars directly from clinical swabs rather than requiring cell enrichment using microbial culture techniques.

A Constitutively Mannose-Sensitive Agglutinating Salmonella enterica subsp. enterica Serovar Typhimurium Strain, Carrying a Transposon in the Fimbrial Usher Gene stbC, Exhibits Multidrug Resistance and Flagellated Phenotypes

Directory of Open Access Journals (Sweden)

Kuan-Hsun Wu

2012-01-01

Full Text Available Static broth culture favors Salmonella enterica subsp. enterica serovar Typhimurium to produce type 1 fimbriae, while solid agar inhibits its expression. A transposon inserted in stbC, which would encode an usher for Stb fimbriae of a non-flagellar Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, conferred it to agglutinate yeast cells on both cultures. RT-PCR revealed that the expression of the fimbrial subunit gene fimA, and fimZ, a regulatory gene of fimA, were both increased in the stbC mutant when grown on LB agar; fimW, a repressor gene of fimA, exhibited lower expression. Flagella were observed in the stbC mutant and this phenotype was correlated with the motile phenotype. Microarray data and RT-PCR indicated that the expression of three genes, motA, motB, and cheM, was enhanced in the stbC mutant. The stbC mutant was resistant to several antibiotics, consistent with the finding that expression of yhcQ and ramA was enhanced. A complementation test revealed that transforming a recombinant plasmid possessing the stbC restored the mannose-sensitive agglutination phenotype to the stbC mutant much as that in the parental Salmonella enterica subsp. enterica serovar Typhimurium LB5010 strain, indicating the possibility of an interplay of different fimbrial systems in coordinating their expression.

Household transmission of leptospira infection in urban slum communities.

Directory of Open Access Journals (Sweden)

Elves A P Maciel

2008-01-01

Full Text Available Leptospirosis, a spirochaetal zoonotic disease, is the cause of epidemics associated with high mortality in urban slum communities. Infection with pathogenic Leptospira occurs during environmental exposures and is traditionally associated with occupational risk activities. However, slum inhabitants reside in close proximity to environmental sources of contamination, suggesting that transmission during urban epidemics occurs in the household environment.A survey was performed to determine whether Leptospira infection clustered within households located in slum communities in the city of Salvador, Brazil. Hospital-based surveillance identified 89 confirmed cases of leptospirosis during an outbreak. Serum samples were obtained from members of 22 households with index cases of leptospirosis and 52 control households located in the same slum communities. The presence of anti-Leptospira agglutinating antibodies was used as a marker for previous infection. In households with index cases, 22 (30% of 74 members had anti-Leptospira antibodies, whereas 16 (8% of 195 members from control households had anti-Leptospira antibodies. Highest titres were directed against L. interrogans serovars of the Icterohaemorrhagiae serogroup in 95% and 100% of the subjects with agglutinating antibodies from case and control households, respectively. Residence in a household with an index case of leptospirosis was associated with increased risk (OR 5.29, 95% CI 2.13-13.12 of having had a Leptospira infection. Increased infection risk was found for all age groups who resided in a household with an index case, including children <15 years of age (P = 0.008.This study identified significant household clustering of Leptospira infection in slum communities where recurrent epidemics of leptospirosis occur. The findings support the hypothesis that the household environment is an important transmission determinant in the urban slum setting. Prevention therefore needs to target

Construction of physical and genetic maps of Chlamydia trachomatis serovar L2 by pulsed-field gel electrophoresis

DEFF Research Database (Denmark)

Birkelund, Svend; Stephens, RS

1992-01-01

We constructed the physical map of Chlamydia trachomatis serovar L2 by using three restriction endonucleases, NotI (GC[GGCCGC), SgrAI (C(A/G)[CCGG(T/G)G), and Sse8387I (CCTGCA[GG), and we analyzed the fragments by pulsed-field gel electrophoresis. A total of 25 restriction endonuclease sites and 13...... genes and/or operons were located on the map. The genome size was determined to be 1,045 kb. Neither highly transcribed chlamydia genes nor developmental cycle-specific genes were clustered on the genome....

Comparative proteomic analysis of Salmonella enterica serovar Typhimurium ppGpp-deficient mutant to identify a novel virulence protein required for intracellular survival in macrophages

Directory of Open Access Journals (Sweden)

Kumagai Yoshinori

2010-12-01

Full Text Available Abstract Background The global ppGpp-mediated stringent response in pathogenic bacteria plays an important role in the pathogenesis of bacterial infections. In Salmonella enterica serovar Typhimurium (S. Typhimurium, several genes, including virulence genes, are regulated by ppGpp when bacteria are under the stringent response. To understand the control of virulence genes by ppGpp in S. Typhimurium, agarose 2-dimensional electrophoresis (2-DE combined with mass spectrometry was used and a comprehensive 2-DE reference map of amino acid-starved S. Typhimurium strain SH100, a derivative of ATCC 14028, was established. Results Of the 366 examined spots, 269 proteins were successfully identified. The comparative analysis of the wild-type and ppGpp0 mutant strains revealed 55 proteins, the expression patterns of which were affected by ppGpp. Using a mouse infection model, we further identified a novel virulence-associated factor, STM3169, from the ppGpp-regulated and Salmonella-specific proteins. In addition, Salmonella strains carrying mutations in the gene encoding STM3169 showed growth defects and impaired growth within macrophage-like RAW264.7 cells. Furthermore, we found that expression of stm3169 was controlled by ppGpp and SsrB, a response regulator of the two-component system located on Salmonella pathogenicity island 2. Conclusions A proteomic approach using a 2-DE reference map can prove a powerful tool for analyzing virulence factors and the regulatory network involved in Salmonella pathogenesis. Our results also provide evidence of a global response mediated by ppGpp in S. enterica.

Activation of type III interferon genes by pathogenic bacteria in infected epithelial cells and mouse placenta.

Directory of Open Access Journals (Sweden)

Hélène Bierne

Full Text Available Bacterial infections trigger the expression of type I and II interferon genes but little is known about their effect on type III interferon (IFN-λ genes, whose products play important roles in epithelial innate immunity against viruses. Here, we studied the expression of IFN-λ genes in cultured human epithelial cells infected with different pathogenic bacteria and in the mouse placenta infected with Listeria monocytogenes. We first showed that in intestinal LoVo cells, induction of IFN-λ genes by L. monocytogenes required bacterial entry and increased further during the bacterial intracellular phase of infection. Other Gram-positive bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis, also induced IFN-λ genes when internalized by LoVo cells. In contrast, Gram-negative bacteria Salmonella enterica serovar Typhimurium, Shigella flexneri and Chlamydia trachomatis did not substantially induce IFN-λ. We also found that IFN-λ genes were up-regulated in A549 lung epithelial cells infected with Mycobacterium tuberculosis and in HepG2 hepatocytes and BeWo trophoblastic cells infected with L. monocytogenes. In a humanized mouse line permissive to fetoplacental listeriosis, IFN-λ2/λ3 mRNA levels were enhanced in placentas infected with L. monocytogenes. In addition, the feto-placental tissue was responsive to IFN-λ2. Together, these results suggest that IFN-λ may be an important modulator of the immune response to Gram-positive intracellular bacteria in epithelial tissues.

Iron-regulated proteins (IRPS of leptospira biflexa serovar Patoc strain Patoc I

Directory of Open Access Journals (Sweden)

Sritharan M

2004-01-01

Full Text Available BACKGROUND: Iron deficiency has been shown to induce the expression of siderophores and their receptors, the iron-regulated membrane proteins in a number of bacterial systems. In this study, the response of Leptospira biflexa serovar Patoc strain Patoc I to conditions of iron deprivation was assessed and the expression of siderophores and iron-regulated proteins is reported. MATERIALS AND METHODS: Two methods were used for establishing conditions of iron deprivation. One method consisted of addition of the iron chelators ethylenediamine-N, N′-diacetic acid (EDDA and ethylenediamine di-o-hydroxyphenylacetic acid (EDDHPA and the second method involved the addition of iron at 0.02 µg Fe/mL. Alternatively, iron sufficient conditions were achieved by omitting the chelators in the former method and adding 4 µg Fe/mL of the medium in the latter protocol. Triton X-114 extraction of the cells was done to isolate the proteins in the outer membrane (detergent phase, periplasmic space (aqueous phase and the protoplasmic cylinder (cell pellet. The proteins were subjected to SDS-PAGE for analysis. RESULTS: In the presence of the iron-chelators, four iron-regulated proteins (IRPs of apparent molecular masses of 82, 64, 60 and 33 kDa were expressed. The 82-kDa protein was seen only in the aqueous phase, while the other three proteins were seen in both the aqueous and detergent fractions. These proteins were not identified in organisms grown in the absence of the iron chelators. The 64, 60 and the 33 kDa proteins were also demonstrated in organisms grown in media with 0.02 µg Fe/mL. In addition, a 24 kDa protein was found to be down-regulated at this concentration of iron as compared to the high level of expression in organisms grown with 4 µg Fe/mL. The blue CAS agar plates with top agar containing 0.02µg Fe/mL showed a colour change to orange-red. CONCLUSION: The expression of siderophores and iron-regulated proteins under conditions of iron deprivation

Typhoid fever

DEFF Research Database (Denmark)

Wain, John; Hendriksen, Rene S.; Mikoleit, Matthew L.

2015-01-01

Control of typhoid fever relies on clinical information, diagnosis, and an understanding for the epidemiology of the disease. Despite the breadth of work done so far, much is not known about the biology of this human-adapted bacterial pathogen and the complexity of the disease in endemic areas...... with shifting trends in enteric fever. This knowledge is crucial, both to control the disease and to manage cases. Additionally, salmonella serovars that cause human infection can change over time and location. In areas of Asia, multidrug-resistant Salmonella enterica serovar Typhi (S Typhi) has been the main...... cause of enteric fever, but now S Typhi is being displaced by infections with drug-resistant S enterica serovar Paratyphi A. New conjugate vaccines are imminent and new treatments have been promised, but the engagement of local medical and public health institutions in endemic areas is needed to allow...

Genetic diversity of Leptospira in northwestern Colombia: first report of Leptospira santarosai as a recognised leptospirosis agent

Directory of Open Access Journals (Sweden)

Ronald Guillermo Peláez Sanchez

Full Text Available The region of Antioquia in northeastern Colombia has the highest number of reported leptospirosis cases in the country. It also shows high seroprevalence indexes in the general population and socio-environmental conditions favourable for the transmission of the disease between humans and animals. In this study, 25 Leptospira isolates from Colombia’s Antioquia department were identified to the species level as L. santarosai (12, L. interrogans (9 and L. meyeri (4 using phylogenetic analysis of the Amidohydrolase gene. Typing at the serovar level was performed using multilocus sequence typing (MLST and monoclonal antibodies. The serovars Canalzonae, Babudieri, Alice, Beye, and Copenhageni have been identified as causing human or animal infections in Antioquia, Colombia. The four environmental isolates were not identified to the serovar level. L. santarosai serovar Canalzonae and Alice were identified as new etiologic agents of human leptospirosis in Antioquia, Colombia. This paper reports species and serovars that were previously unknown in the region.

Genomics of an emerging clone of Salmonella serovar Typhimurium ST313 from Nigeria and the Democratic Republic of Congo.

Science.gov (United States)

Leekitcharoenphon, Pimlapas; Friis, Carsten; Zankari, Ea; Svendsen, Christina Aaby; Price, Lance B; Rahmani, Maral; Herrero-Fresno, Ana; Fashae, Kayode; Vandenberg, Olivier; Aarestrup, Frank M; Hendriksen, Rene S

2013-10-15

Salmonella enterica serovar Typhimurium ST313 is an invasive and phylogenetically distinct lineage present in sub-Saharan Africa. We report the presence of S. Typhimurium ST313 from patients in the Democratic Republic of Congo and Nigeria. Eighteen S. Typhimurium ST313 isolates were characterized by antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). Additionally, six of the isolates were characterized by whole genome sequence typing (WGST). The presence of a putative virulence determinant was examined in 177 Salmonella isolates belonging to 57 different serovars. All S. Typhimurium ST313 isolates harbored resistant genes encoded by blaTEM1b, catA1, strA/B, sul1, and dfrA1. Additionally, aac(6')1aa gene was detected. Phylogenetic analyses revealed close genetic relationships among Congolese and Nigerian isolates from both blood and stool. Comparative genomic analyses identified a putative virulence fragment (ST313-TD) unique to S. Typhimurium ST313 and S. Dublin. We showed in a limited number of isolates that S. Typhimurium ST313 is a prevalent sequence-type causing gastrointestinal diseases and septicemia in patients from Nigeria and DRC. We found three distinct phylogenetic clusters based on the origin of isolation suggesting some spatial evolution. Comparative genomics showed an interesting putative virulence fragment (ST313-TD) unique to S. Typhimurium ST313 and invasive S. Dublin.

Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

Directory of Open Access Journals (Sweden)

Lilian Terezinha de Queiroz Leite

1996-10-01

Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.Anticorpos monoclonais (AcM foram produzidos contra o extrato EDTA obtido de Leptospira interrogans, sorovar icterohaemorrhagiae. Pelo teste de precipitação foram caracterizados como IgM e IgG (IgGl e IgG2. A eletroforese em gel de poliacrilamida do extrato EDTA revelou diversas bandas quando corada pela prata. No "Western blot", as bandas em torno de 20 kDa reagiram com o AcM 47B4D6, foram oxidadas pelo periodato e não digeridas pela pronase, sugerindo que o determinante é de natureza carboidrato. O determinante reconhecido pelo AcM 47B4D6 estã localizado sob o envelope externo como revelado pela imunocitoquímica usando marcação com ouro coloidal. O AcM contra extrato EDTA do sorovar icterohaemorrahagiae não protegeu hamsters quando inoculados com lepstopira homóloga virulenta.

Diminuição da fragilidade osmótica eritrocitária na leptospirose canina

OpenAIRE

Santoro, Marcelo L.; Kogika, Marcia M.; Hagiwara, Mitika K.; Mirandola, Regina M. S.; Castelar, Izaura L. C. G.

1994-01-01

Erythrocyte osmotic fragility (EOF) was carried out in nineteen dogs naturally infected by Leptospira interrogans serovar icterohaemorrhagiae/copenhagi. A decreased EOF was observed, suggesting a modification of erythrocyte components secondary to disturbances that occur during canine leptospirosis, such as renal damage and hepatic disease.A fragilidade osmótica eritrocitária foi estudada em dezenove cães infectados naturalmente pela Leptospira interrogans serovar icterohaemorrhagiae/copenhag...

Antibiotic Resistance of Salmonella enterica Serovar Typhi in Kolkata, India, and In Vitro Experiments on Effect of Combined Chemotherapy

Directory of Open Access Journals (Sweden)

Shyamapada Mandal

2012-01-01

Full Text Available This communication states the changing patterns of Salmonella enterica serovar Typhi (S. Typhi isolates causing enteric fever in and around Kolkata, India. Among the isolates resistance to ampicillin (A, chloramphenicol (C, cotrimoxazole (Co and tetracycline (T were plasmid mediated; the plasmid was unstable in S. Typhi, and the other enteric bacteria like Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were found to be the potential source of dissemination of such plasmids into S. Typhi. The infection with such S. Typhi strains were successfully treated with ciprofloxacin (Cp: MICs 0.0075–0.075 μg mL−1 and/or ofloxacin (Ofx: MICs 0.0125–0.075 μg mL−1, but in the later course, the S. Typhi strains, showing resistance to nalidixic acid, developed low level of resistance to Cp and Ofx, causing the treatment failure. Thus, the treatment regimen was shifted to the third generation cephalosporins like ceftriaxone (Ct and cefotaxime (Cf. Keeping in mind the anticipation of development of resistance to Ct/Cf, we prepared the treatment regimen for MDR enteric fever, based on the double-drug synergy tests in vitro; Cp-gentamycin (FICI 0.121–0.216 and Cp-trimethoprim (FICI 0.14–0.483 combinations were found effective against S. Typhi isolates having decreased sensitivity to cp (MICs: 0.5–1.25 μg mL−1.

Impact of the choice of reference genome on the ability of the core genome SNV methodology to distinguish strains of Salmonella enterica serovar Heidelberg.

Science.gov (United States)

Usongo, Valentine; Berry, Chrystal; Yousfi, Khadidja; Doualla-Bell, Florence; Labbé, Genevieve; Johnson, Roger; Fournier, Eric; Nadon, Celine; Goodridge, Lawrence; Bekal, Sadjia

2018-01-01

Salmonella enterica serovar Heidelberg (S. Heidelberg) is one of the top serovars causing human salmonellosis. The core genome single nucleotide variant pipeline (cgSNV) is one of several whole genome based sequence typing methods used for the laboratory investigation of foodborne pathogens. SNV detection using this method requires a reference genome. The purpose of this study was to investigate the impact of the choice of the reference genome on the cgSNV-informed phylogenetic clustering and inferred isolate relationships. We found that using a draft or closed genome of S. Heidelberg as reference did not impact the ability of the cgSNV methodology to differentiate among 145 S. Heidelberg isolates involved in foodborne outbreaks. We also found that using a distantly related genome such as S. Dublin as choice of reference led to a loss in resolution since some sporadic isolates were found to cluster together with outbreak isolates. In addition, the genetic distances between outbreak isolates as well as between outbreak and sporadic isolates were overall reduced when S. Dublin was used as the reference genome as opposed to S. Heidelberg.

Heterophil Phagocytic Activity Stimulated by L61 and L55 Supplementation in Broilers with Infection

Directory of Open Access Journals (Sweden)

Pairat Sornplang

2015-11-01

Full Text Available Newborn chicks are susceptible to Salmonella enterica serovar Enteritidis (SE. The objective of this study was to evaluate the effect of Lactobacillus probiotic isolated from chicken feces on heterophil phagocytosis in broiler chicks. A total of 150 newborn broiler chicks were divided into 5 groups (30 chicks per group as follows: group 1 (normal control, given feed and water only, group 2 (positive control given feed, water and SE infection, group 3 (L61 treated given feed, water, SE infection followed by Lactobacillus salivarius L61 treatment, group 4 (L55 treated given feed, water, SE infection followed by L. salivarius L55 treatment, and group 5 given feed, water, SE infection followed by L. salivarius L61 + L55 combination treatment. After SE infection, L. salivarius treatment lasted for 7 days. The results showed that L. salivarius L61 and L. salivarius L55 treatment, either alone or combination of both, increased the survival rate after SE infection, and upregulated heterophil phagocytosis and phagocytic index (PI. Conversely, chick groups treated with Lactobacillus showed lower SE recovery rate from cecal tonsils than that of the positive control group. The PI values of the chicken group with SE infection, followed by the combination of L. salivarius L61 and L. salivarius L55 were the highest as compared to either positive control or normal control group. Two Lactobacillus strains supplementation group showed significantly (p<0.05 higher PI value at 48 h than 24 h after treatment.

[Lymphogranuloma venereum: the first Hungarian cases].

Science.gov (United States)

Bánvölgyi, András; Balla, Eszter; Bognár, Péter; Tóth, Béla; Ostorházi, Eszter; Bánhegyi, Dénes; Kárpáti, Sarolta; Marschalkó, Márta

2015-01-04

Lymphogranuloma venereum is a sexually transmitted infection caused by the Chlamydia trachomatis serovars L1-3. It has been found to be endemic in tropical countries. In the last decades several cases have been reported in Western Europe, particularly in men who have sex with men population infected with human immunodeficiency virus. The authors present three cases of lymphogranuloma venereum infections, observed at their department in 2013 and 2014. The three human immunodeficiency virus infected patients who belonged to men who have sex with men population had casual sexual contacts in Western Europe. The symptoms included urethral discharge, discomfort and inguinal lymphadenomegaly in two patients, and rectal pain, discharge and perianal ulceration in one patient. The diagnosis was confirmed by nucleic acid amplification test performed in samples obtained from urethral discharge and exudate of perianal ulcer; lymphogranuloma venereum 2b serovars were demonstrated in two patients and serovar 2 in one patient. Doxycyclin (daily dose of two times 100 mg for 21 days) resolved the symptoms in all cases. The authors conclude that lymphogranuloma venereum is a diagnostic challenge in Hungary, too. It is important to be aware of the altered clinical features of this disease to prevent complications and spreading.

Salmonella infection in healthy pet reptiles: Bacteriological isolation and study of some pathogenic characters.

Science.gov (United States)

Bertelloni, Fabrizio; Chemaly, Marianne; Cerri, Domenico; Gall, Françoise Le; Ebani, Valentina Virginia

2016-06-01

The fecal samples from 213 captive reptiles were examined, and 29 (13.61%) Salmonella enterica isolates were detected: 14/62 (22.58%) from chelonians, 14/135 (10.37%) from saurians, and 1/16 (6.25%) from ophidians. The isolates were distributed among 14 different serotypes: Miami, Ebrie, Hermannsweder, Tiergarten, Tornov, Pomona, Poona, Goteborg, Abaetetube, Nyanza, Kumasi, Typhimurium, 50:b:z6, 9,12:z29:1,5, and a non-motile serotype with antigenic formula 1,4,[5],12:-:-. Salmonella typhimurium and 50:b:z6 isolates showed the spv plasmid virulence genes, responsible of the capability to induce extra-intestinal infections. In some cases, pulsed field gel electrophoresis revealed different profiles for the strains of the same serotypes, showing different origins, whereas a common source of infection was supposed when one pulsotype had been observed for isolates of a serovar. Twenty-seven (93.10%) isolates showed resistance to one or more antibiotics. Ceftazidime was active to all the tested isolates, whereas the highest percentages of strains were no susceptible to tigecycline (93.10%), streptomycin (89.66%), and sulfonamide (86.21%).

Neutrophil Extracellular Traps are Involved in the Innate Immune Response to Infection with Leptospira

Science.gov (United States)

Scharrig, Emilia; Carestia, Agostina; Ferrer, María F.; Cédola, Maia; Pretre, Gabriela; Drut, Ricardo; Picardeau, Mathieu; Schattner, Mirta; Gómez, Ricardo M.

2015-01-01

NETosis is a process by which neutrophils extrude their DNA together with bactericidal proteins that trap and/or kill pathogens. In the present study, we evaluated the ability of Leptospira spp. to induce NETosis using human ex vivo and murine in vivo models. Microscopy and fluorometric studies showed that incubation of human neutrophils with Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 (LIC) resulted in the release of DNA extracellular traps (NETs). The bacteria number, pathogenicity and viability were relevant factors for induction of NETs, but bacteria motility was not. Entrapment of LIC in the NETs resulted in LIC death; however, pathogenic but not saprophytic Leptospira sp. exerted nuclease activity and degraded DNA. Mice infected with LIC showed circulating NETs after 2 days post-infection (dpi). Depletion of neutrophils with mAb1A8 significantly reduced the amount of intravascular NETs in LIC-infected mice, increasing bacteremia at 3 dpi. Although there was a low bacterial burden, scarce neutrophils and an absence of inflammation in the early stages of infection in the kidney and liver, at the beginning of the leptospiruric phase, the bacterial burden was significantly higher in kidneys of neutrophil-depleted-mice compared to non-depleted and infected mice. Surprisingly, interstitial nephritis was of similar intensity in both groups of infected mice. Taken together, these data suggest that LIC triggers NETs, and that the intravascular formation of these DNA traps appears to be critical not only to prevent early leptospiral dissemination but also to preclude further bacterial burden. PMID:26161745

[Lymphogranuloma venereum proctocolitis in men with HIV-1 infection].

Science.gov (United States)

Heras, Eva; Llibre, Josep M; Martró, Elisa; Casabona, Jordi; Martin-Iguacel, Raquel; Martín, Raquel; Sirera, Guillem

2011-02-01

We present a series of 15 cases with lymphogranuloma venereum (LGV) with the aim of evaluating the response to a 21-day oral course of doxycycline (100mg twice daily). It is an observational study where we describe a series of cases with LGV diagnosed in the Hospital Germans Trias i Pujol's HIV Unit between March 2008 and April 2009. All our patients were HIV infected men who had sex with men with proctitis in 80% of the cases. In all of them Chlamydia trachomatis was determined by PCR on rectal swab specimens, with a negative result after 21 days of treatment with doxycycline. Serovar L2 was confirmed in all the specimens with the reverse hybridization technique. A high index of clinical suspicion is the mainstay to the early diagnosis of LGV since the clinical presentation remains unspecific. The treatment with doxycycline eradicates C. trachomatis in HIV patients with LGV. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Inguinal and anorectal Lymphogranuloma Venereum: a case series from a sexually transmitted disease center in Rome, Italy.

Science.gov (United States)

Latini, Alessandra; Zaccarelli, Mauro; Paglia, Maria Grazia; Donà, Maria Gabriella; Giglio, Amalia; Moretto, Domenico; Vulcano, Antonella; Giuliani, Massimo; Colafigli, Manuela; Ambrifi, Marina; Pimpinelli, Fulvia; Cristaudo, Antonio

2017-06-02

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by L1, L2, L3 serovars of C. trachomatis (CT). Since 2003, LGV cases have been increasing in Europe. Aim of this report is to describe the LGV cases diagnosed in the largest STI center in Rome, Italy, from 2000 to 2016. This report shows that two clinically and epidemiologically different series of cases exist, and that, at present, the ano-rectal LGV represents the clinical variant occurring more frequently among men having sex with men (MSM), particularly those HIV-infected. Ten cases of LGV were observed. Three were diagnosed in 2009 in HIV-negative heterosexuals patients that presented the classical genito-ulcerative form with lymphadenopathy. Seven cases were observed in 2015-2016 in HIV-infected MSM, that presented the rectal variant and L2b serovar infection; 4 of these had been misclassified as a chronic bowel disease. Chlamydia infection was confirmed by CT-specific PCR (ompA gene nested PCR), followed by sequence analysis to identify the serovar. All the patients were treated with doxycycline for 3 weeks, obtaining a complete response with healing of both clinical symptoms and dermatological lesions. Our findings suggest that, in case of persistent rectal symptoms in HIV-infected MSM, LGV should be taken into account and investigated through molecular analyses, in order to achieve a correct diagnosis and management of the patients.

The Use of a Combined Bioinformatics Approach to Locate Antibiotic Resistance Genes on Plasmids From Whole Genome Sequences of Salmonella enterica Serovars From Humans in Ghana

Directory of Open Access Journals (Sweden)

Egle Kudirkiene

2018-05-01

Full Text Available In the current study, we identified plasmids carrying antimicrobial resistance genes in draft whole genome sequences of 16 selected Salmonella enterica isolates representing six different serovars from humans in Ghana. The plasmids and the location of resistance genes in the genomes were predicted using a combination of PlasmidFinder, ResFinder, plasmidSPAdes and BLAST genomic analysis tools. Subsequently, S1-PFGE was employed for analysis of plasmid profiles. Whole genome sequencing confirmed the presence of antimicrobial resistance genes in Salmonella isolates showing multidrug resistance phenotypically. ESBL, either blaTEM52−B or blaCTX−M15 were present in two cephalosporin resistant isolates of S. Virchow and S. Poona, respectively. The systematic genome analysis revealed the presence of different plasmids in different serovars, with or without insertion of antimicrobial resistance genes. In S. Enteritidis, resistance genes were carried predominantly on plasmids of IncN type, in S. Typhimurium on plasmids of IncFII(S/IncFIB(S/IncQ1 type. In S. Virchow and in S. Poona, resistance genes were detected on plasmids of IncX1 and TrfA/IncHI2/IncHI2A type, respectively. The latter two plasmids were described for the first time in these serovars. The combination of genomic analytical tools allowed nearly full mapping of the resistance plasmids in all Salmonella strains analyzed. The results suggest that the improved analytical approach used in the current study may be used to identify plasmids that are specifically associated with resistance phenotypes in whole genome sequences. Such knowledge would allow the development of rapid multidrug resistance tracking tools in Salmonella populations using WGS.

Heterophil Phagocytic Activity Stimulated by Lactobacillus salivarius L61 and L55 Supplementation in Broilers with Salmonella Infection.

Science.gov (United States)

Sornplang, Pairat; Leelavatcharamas, Vichai; Soikum, Chaiyaporn

2015-11-01

Newborn chicks are susceptible to Salmonella enterica serovar Enteritidis (SE). The objective of this study was to evaluate the effect of Lactobacillus probiotic isolated from chicken feces on heterophil phagocytosis in broiler chicks. A total of 150 newborn broiler chicks were divided into 5 groups (30 chicks per group) as follows: group 1 (normal control), given feed and water only, group 2 (positive control) given feed, water and SE infection, group 3 (L61 treated) given feed, water, SE infection followed by Lactobacillus salivarius L61 treatment, group 4 (L55 treated) given feed, water, SE infection followed by L. salivarius L55 treatment, and group 5 given feed, water, SE infection followed by L. salivarius L61 + L55 combination treatment. After SE infection, L. salivarius treatment lasted for 7 days. The results showed that L. salivarius L61 and L. salivarius L55 treatment, either alone or combination of both, increased the survival rate after SE infection, and upregulated heterophil phagocytosis and phagocytic index (PI). Conversely, chick groups treated with Lactobacillus showed lower SE recovery rate from cecal tonsils than that of the positive control group. The PI values of the chicken group with SE infection, followed by the combination of L. salivarius L61 and L. salivarius L55 were the highest as compared to either positive control or normal control group. Two Lactobacillus strains supplementation group showed significantly (p<0.05) higher PI value at 48 h than 24 h after treatment.

Homologous stress adaptation, antibiotic resistance, and biofilm forming ability of Salmonella enterica serovar Heidelberg (ATCC8326) on different food-contact surfaces following exposure to sub-lethal chlorine concentrations

Science.gov (United States)

Salmonella enterica serovar Heidelberg (American Type Culture Collection; ATCC 8326) was examined for the ability to adapt to the homologous stress of chlorine through exposure to increasing chlorine concentrations (25 ppm daily increments) in tryptic soy broth (TSB). The tested strain exhibited an ...

Survey of risk factors for the prevalence of leptospiral infection in horses of Gonbad area

Directory of Open Access Journals (Sweden)

omid jaheddashliboroun

2013-08-01

Full Text Available Leptospirosis is a world-wide zoonotic infection occurring in animals and humans. Rodents and wild animals are a major source of infection. Clinical signs in animals include fever, heamoglubinuria, jaundice, abortion, mastitis, reduced milk production, reproductive failure and death with periodic ophthalmia, abortion and stillbirths being among its important signs in horses. The main purpose of this study was to investigate the risk factors for the prevalence of leptospiral infection in horses of Gonbad area. This study was conducted on 200 horses in Gonbad area in Iran in order to determine seroprevalence of leptospiral infection. Sera were initially screened at dilution of 1:100 against 7 live serovars of Leptospira interrogans: Pomona, Canicola, Hardjo, Ballom, Icterohaemorrhagiae, AutomenalisandGrippotyphosausing themicroscopic agglutination test. The prevalence of leptospiral infection was 12% in horses. The majority of these infections were seen in horses that live in marsh and semi-marsh conditions and they accounted for 89% of positive samples. The highest number of reactors in horses (58.34% wasdue toserovarCanicola and 33.34% of positive samples were seen in horses with many rodents living in their environment.66.67% of positive samples were seen in horses that were kept In moist and semi moist stables. The highest number of positive samples were seen in 3 to 6 years old animals, in other words prevalence of this disease is raised with increase of age. So according to the results, increasing age, living in marsh environment, moist stable presence of infected dogs and rodents, in environment are some of risks factors for prevalence of leptospiral infection

The transcriptional programme of Salmonella enterica serovar Typhimurium reveals a key role for tryptophan metabolism in biofilms.

LENUS (Irish Health Repository)

Hamilton, Shea

2009-12-11

Abstract Background Biofilm formation enhances the capacity of pathogenic Salmonella bacteria to survive stresses that are commonly encountered within food processing and during host infection. The persistence of Salmonella within the food chain has become a major health concern, as biofilms can serve as a reservoir for the contamination of food products. While the molecular mechanisms required for the survival of bacteria on surfaces are not fully understood, transcriptional studies of other bacteria have demonstrated that biofilm growth triggers the expression of specific sets of genes, compared with planktonic cells. Until now, most gene expression studies of Salmonella have focused on the effect of infection-relevant stressors on virulence or the comparison of mutant and wild-type bacteria. However little is known about the physiological responses taking place inside a Salmonella biofilm. Results We have determined the transcriptomic and proteomic profiles of biofilms of Salmonella enterica serovar Typhimurium. We discovered that 124 detectable proteins were differentially expressed in the biofilm compared with planktonic cells, and that 10% of the S. Typhimurium genome (433 genes) showed a 2-fold or more change in the biofilm compared with planktonic cells. The genes that were significantly up-regulated implicated certain cellular processes in biofilm development including amino acid metabolism, cell motility, global regulation and tolerance to stress. We found that the most highly down-regulated genes in the biofilm were located on Salmonella Pathogenicity Island 2 (SPI2), and that a functional SPI2 secretion system regulator (ssrA) was required for S. Typhimurium biofilm formation. We identified STM0341 as a gene of unknown function that was needed for biofilm growth. Genes involved in tryptophan (trp) biosynthesis and transport were up-regulated in the biofilm. Deletion of trpE led to decreased bacterial attachment and this biofilm defect was restored by

Salmonella enterica serovar Enteritidis brain abscess mimicking meningitis after surgery for glioblastoma multiforme: a case report and review of the literature

OpenAIRE

Luciani, L?a; Dubourg, Gr?gory; Graillon, Thomas; Honnorat, Estelle; Lepidi, Hubert; Drancourt, Michel; Seng, Piseth; Stein, Andreas

2016-01-01

Background Salmonella brain abscess associated with brain tumor is rare. Only 11 cases have been reported to date. Here we report a case of brain abscess caused by Salmonella enterica serovar Enteritidis mimicking post-surgical meningitis in a patient with glioblastoma multiforme. Case presentation A 60-year-old Algerian woman was admitted through an emergency department for a 4-day history of headache, nausea and vomiting, and behavioral disorders. Surgery for cerebral tumor excision was per...

Isolation of Salmonella enterica and serologic reactivity to Leptospira interrogans in opossums (Didelphis virginiana) from Yucatán, México.

Science.gov (United States)

Ruiz-Pina, Hugo Antonio; Puc-Franco, Miguel Angel; Flores-Abuxapqui, Javier; Vado-Solis, Ignacio; Cardenas-Marrufo, María Fidelia

2002-01-01

The presence of Salmonella enterica and serologic evidence of infection by Leptospira interrogans, were detected in the opossum Didelphis virginiana in a semi-urban locality of the Yucatán State, México. Ninety-one opossums were captured during the period April 1996 and May 1998. From a total of 17 feces samples, four Salmonella enterica subsp. enterica serotypes (Sandiego, Newport, Anatum, and Minnesota), and one Salmonella enterica subsp. arizonae serovar O44:Z4,Z23:- were isolated. Some opossums presented mixed infections. From 81 sera samples, four (4.9%) were positive to antibodies to Leptospira serovars pomona and wolfii. Both animals infected with Salmonella enterica and those serologically positive to Leptospira interrogans were captured in peridomestic habitat. Opossums infected with Salmonella enterica, were captured in dry season, and those seropositive to Leptospira interrogans during the rainy season. The implications of infection and reactivity of these zoonotic pathogens in D. virginiana in the Yucatan state are briefly discussed.

An allele of an ancestral transcription factor dependent on a horizontally acquired gene product.

Science.gov (United States)

Chen, H Deborah; Jewett, Mollie W; Groisman, Eduardo A

2012-01-01

Changes in gene regulatory circuits often give rise to phenotypic differences among closely related organisms. In bacteria, these changes can result from alterations in the ancestral genome and/or be brought about by genes acquired by horizontal transfer. Here, we identify an allele of the ancestral transcription factor PmrA that requires the horizontally acquired pmrD gene product to promote gene expression. We determined that a single amino acid difference between the PmrA proteins from the human adapted Salmonella enterica serovar Paratyphi B and the broad host range S. enterica serovar Typhimurium rendered transcription of PmrA-activated genes dependent on the PmrD protein in the former but not the latter serovar. Bacteria harboring the serovar Typhimurium allele exhibited polymyxin B resistance under PmrA- or under PmrA- and PmrD-inducing conditions. By contrast, isogenic strains with the serovar Paratyphi B allele displayed PmrA-regulated polymyxin B resistance only when experiencing activating conditions for both PmrA and PmrD. We establish that the two PmrA orthologs display quantitative differences in several biochemical properties. Strains harboring the serovar Paratyphi B allele showed enhanced biofilm formation, a property that might promote serovar Paratyphi B's chronic infection of the gallbladder. Our findings illustrate how subtle differences in ancestral genes can impact the ability of horizontally acquired genes to confer new properties.

Safety and efficacy of a new octavalent combined Erysipelas, Parvo and Leptospira vaccine in gilts against Leptospira interrogans serovar Pomona associated disease and foetal death.

Science.gov (United States)

Jacobs, A A C; Harks, F; Hoeijmakers, M; Collell, M; Segers, R P A M

2015-07-31

The safety and protective efficacy of a new octavalent combination vaccine containing inactivated Erysipelothrix rhusiopathiae, Parvovirus, and Leptospira interrogans (sensu lato) serogroups Canicola, Icterohaemorrhagiae, Australis (Bratislava), Grippotyphosa, Pomona and Tarassovi - Porcilis(®) Ery+Parvo+Lepto - was evaluated in laboratory studies and under field conditions. The safety (2× overdose and repeated dose) was tested in 26 gilts. In this study, neither vaccine related temperature increase nor other systemic reactions were observed after intramuscular vaccination. No local reactions were observed except for one animal that had a small local reaction (2cm diameter) that lasted for 5 days after the third vaccination. Efficacy was tested in 40 gilts. A group of 20 gilts was vaccinated at 20 and 24 weeks of age with Porcilis(®) Ery+Parvo+Lepto and a group of 20 age- and source-matched animals served as the control group. The gilts were inseminated at 41 weeks or 66 weeks of age and were challenged with serovar Pomona 10 weeks after insemination, corresponding to 6 months (n=2×10) and 12 months (n=2×10) after the last vaccination. After both the 6- and 12-month challenges the control animals developed clinical signs (fever, lethargy and anorexia) and leptospiraemia as determined by positive blood culture. In addition, both the 6- and 12-month challenges resulted in death of 21% and 27% of the total number of foetuses in the control groups, respectively. Clinical signs and leptospiraemia were statistically significantly lower in vaccinated gilts after both the 6- and 12-month challenges. In addition, foetal death was statistically significantly lower (3% and 2%, respectively) in vaccinated gilts after both the 6- and 12 month challenges. The vaccine was tested further under field conditions on a Portuguese farm with a history of an increasing abortion rate associated with a Leptospira serovar Pomona infection (confirmed by PCR and serology). This study was

Investigation of the role of genes encoding zinc exporters zntA, zitB, and fieF during Salmonella typhimurium infection

DEFF Research Database (Denmark)

Huang, Kaisong; Wang, Dan; Frederiksen, Rikki F.

2018-01-01

The transition metal zinc is involved in crucial biological processes in all living organisms and is essential for survival of Salmonella in the host. However, little is known about the role of genes encoding zinc efflux transporters during Salmonella infection. In this study, we constructed...... deletion mutants for genes encoding zinc exporters (zntA, zitB, and fieF) in the wild-type (WT) strain Salmonella enterica serovar Typhimurium (S. Typhimurium) 4/74. The mutants 4/74ΔzntA and 4/74ΔzntA/zitB exhibited a dramatic growth delay and abrogated growth ability, respectively, in Luria Bertani...... medium supplemented with 0.25 mM ZnCl2 or 1.5 mM CuSO4 compared to the WT strain. In order to investigate the role of genes encoding zinc exporters on survival of S. Typhimurium inside cells, amoeba and macrophage infection models were used. No significant differences in uptake or survival were detected...

Diversity of pulsed-field gel electrophoresis pulsotypes, serovars, and antibiotic resistance among Salmonella isolates from wild amphibians and reptiles in the California Central Coast.

Science.gov (United States)

Gorski, Lisa; Jay-Russell, Michele T; Liang, Anita S; Walker, Samarpita; Bengson, Yingjia; Govoni, Jessica; Mandrell, Robert E

2013-06-01

A survey of cold-blooded vertebrates and associated surface waters in a produce-growing region on the Central California Coast was done between May and September 2011 to determine the diversity of Salmonella. Samples from 460 amphibians and reptiles and 119 water samples were collected and cultured for Salmonella. Animals sampled were frogs (n=331), lizards (n=59), newts (n=5), salamanders (n=6), snakes (n=39), and toads (n=20). Salmonella was isolated from 37 individual animals, including frogs, lizards, snakes, and toads. Snakes were the most likely to contain Salmonella, with 59% testing positive followed by 15.3% of lizards, 5% of toads, and 1.2% of frogs. Fifteen water samples (12.6%) were positive. Twenty-two different serovars were identified, and the majority of isolates were S. enterica subsp. IIIb, with subsp. I, II, and IIIa also found. The serovar isolated most frequently was S. enterica subsp. IIIb 16:z₁₀:e,n,x,z₁₅, from snakes and frogs in five different locations. S. enterica subsp. I serovar Typhimurium and the monophasic I 6,8:d:- were isolated from water, and subspecies I Duisburg and its variants were found in animals and water. Some samples contained more than one type of Salmonella. Analysis of pulsed-field gel electrophoresis pulsotypes indicated that some strains persisted in animals and water collected from the same location. Sixty-six isolates displayed antibiotic resistance, with 27 isolates resistant to more than one antibiotic, including a subspecies IIIb isolate from snake having resistance to five different antibiotics. Twenty-three isolates were resistant to more than one class of antibiotic, and six isolates were resistant to three classes. While these subspecies of IIIa and IIIb cause fewer instances of human illness, they may serve as reservoirs of antibiotic resistance, determinants in the environment, and be sources of contamination of leafy greens associated with product recalls.

Occurrence of multidrug-resistant Salmonella enterica serovar Enteritidis isolates from poultry in Iran

Directory of Open Access Journals (Sweden)

Ghaderi, R.

2016-03-01

Full Text Available Salmonella enterica is recognized as one of the major food-borne pathogens with more than 2,500 serotypes worldwide. The present study addresses antimicrobial resistance of Salmonella enterica serovar Enteritidis isolates in Iran. A collection of 151 Salmonella spp. isolates collected from poultry were serotyped to identify Salmonella Enteritidis. Sixty-one Salmonella Enteritidis were subsequently tested against 30 antimicrobials. A high frequency of antimicrobial resistance was observed against nitrofurantoin (n=55, 90.2% followed by nalidixic acid (n=41, 67.2%, and cephalexin (n=23, 37.7%. Multi-drug resistance were observed in 35 (57.4% out of 61 isolates. Twenty-six antimicrobial resistance patterns were observed among the 61 Salmonella Enteritidis. All isolates were susceptible to ofloxacin, imipenem, enrofloxacin, chloramphenicol, gentamicin, and 3rd and 4th generation cephalosporins. In conclusion, our results revealed that implementing new policies toward overuse of antimicrobial drugs in Iranian poultry industry are of great importance.

Salmonella enterica serovar Typhimurium exploits inflammation to modify swine intestinal microbiota.

Directory of Open Access Journals (Sweden)

Rosanna eDrumo

2016-01-01

Full Text Available Salmonella enterica serovar Typhimurium is an important zoonotic gastrointestinal pathogen responsible for foodborne disease worldwide. It is a successful enteric pathogen because it has developed virulence strategies allowing it to survive in a highly inflamed intestinal environment exploiting inflammation to overcome colonization resistance provided by intestinal microbiota. In this study, we used piglets featuring an intact microbiota, which naturally develop gastroenteritis, as model for salmonellosis. We compared the effects on the intestinal microbiota induced by a wild type and an attenuated S. Typhimurium in order to evaluate whether the modifications are correlated with the virulence of the strain. This study showed that Salmonella alters microbiota in a virulence-dependent manner. We found that the wild type S. Typhimurium induced inflammation and a reduction of specific protecting microbiota species (SCFA-producing bacteria normally involved in providing a barrier against pathogens. Both these effects could contribute to impair colonization resistance, increasing the host susceptibility to wild type S. Typhimurium colonization. In contrast, the attenuated S. Typhimurium, which is characterized by a reduced ability to colonize the intestine, and by a very mild inflammatory response, was unable to successfully sustain competition with the microbiota.

Frequency of serovars and antimicrobial resistance in Shigella spp. from Brazil

Directory of Open Access Journals (Sweden)

Gisele Peirano

2006-05-01

Full Text Available A total of 296 Shigella spp. were received from State Public Health Laboratories, during the period from 1999 to 2004, by National Reference Laboratory for Cholera and Enteric Diseases (NRLCED - IOC/Fiocruz, Rio de Janeiro, Brazil. The frequency of Shigella spp. was: S. flexneri (52.7%, S. sonnei (44.2%, S. boydii (2.3%, and S. dysenteriae (0.6%. The most frequent S. flexneri serovars were 2a and 1b. The highest incidence rates of Shigella isolation were observed in the Southeast (39% and Northeast (34% regions and the lowest rate in the South (3% of Brazil. Strains were further analyzed for antimicrobial susceptibility by disk diffusion method as part of a surveillance program on antimicrobial resistance. The highest rates of antimicrobial resistance were to trimethoprim-sulfamethozaxole (90%, tetracycline (88%, ampicillin (56%, and chloramphenicol (35%. The patterns of antimicrobial resistance among Shigella isolates pose a major difficulty in the determination of an appropriate drug for shigellosis treatment. Continuous monitoring of antimicrobial susceptibilities of Shigella spp. through a surveillance system is thus essential for effective therapy and control measures against shigellosis.

The invasome of Salmonella Dublin as revealed by whole genome sequencing

DEFF Research Database (Denmark)

Mohammed, Manal; Le Hello, Simon; Leekitcharoenphon, Pimlapas

2017-01-01

Salmonella enterica serovar Dublin is a zoonotic infection that can be transmitted from cattle to humans through consumption of contaminated milk and milk products. Outbreaks of human infections by S. Dublin have been reported in several countries including high-income countries. A high proportio...

Comparative genome analysis of 19 Ureaplasma urealyticum and Ureaplasma parvum strains.

Science.gov (United States)

Paralanov, Vanya; Lu, Jin; Duffy, Lynn B; Crabb, Donna M; Shrivastava, Susmita; Methé, Barbara A; Inman, Jason; Yooseph, Shibu; Xiao, Li; Cassell, Gail H; Waites, Ken B; Glass, John I

2012-05-30

pathogenicity and clinical outcome of a ureaplasmal infection is most likely not on the serovar level, but rather may be due to the presence or absence of potential pathogenicity factors in an individual ureaplasma clinical isolate and/or patient to patient differences in terms of autoimmunity and microbiome.

Expression and characterization of recombinant leptospiral outer membrane protein LipL32 from Leptospira interrogans serovar autumnalis.

Science.gov (United States)

Boonsathorn, Naphatsawan; Konghom, Ganokrot; Mongkolsiri, Kaveewan; Jirapongwattana, Chanin; Balachandra, Kruavon; Naigowit, Pimjai; Sawanpanyalert, Pathom

2009-01-01

Leptospira interrogans serovar autumnalis, a causative agent of leptospirosis in Thailand, was isolated from a patient for DNA extraction and amplification of LipL32 gene by polymerase chain reaction (PCR). The 782 bp PCR product was obtained, which was inserted into pAE plasmid with polyhistidine (His6 tag) to construct pAE-LipL32. This recombinant plasmid was transfected into E. coli BL21 (DE3). His6-LipL32 was purified by Ni-NTA affinity chromatography. The recombinant protein was used as antigen for testing with sera from leptospirosis and syphilis patients by dot-ELISA technique. It reacted positively with leptospirosis patient sera and negatively with syphilis and healthy sera.

Genomic characterization of Haemophilus parasuis SH0165, a highly virulent strain of serovar 5 prevalent in China.

Directory of Open Access Journals (Sweden)

Zhuofei Xu

Full Text Available Haemophilus parasuis can be either a commensal bacterium of the porcine respiratory tract or an opportunistic pathogen causing Glässer's disease, a severe systemic disease that has led to significant economical losses in the pig industry worldwide. We determined the complete genomic sequence of H. parasuis SH0165, a highly virulent strain of serovar 5, which was isolated from a hog pen in North China. The single circular chromosome was 2,269,156 base pairs in length and contained 2,031 protein-coding genes. Together with the full spectrum of genes detected by the analysis of metabolic pathways, we confirmed that H. parasuis generates ATP via both fermentation and respiration, and possesses an intact TCA cycle for anabolism. In addition to possessing the complete pathway essential for the biosynthesis of heme, this pathogen was also found to be well-equipped with different iron acquisition systems, such as the TonB system and ABC-type transport complexes, to overcome iron limitation during infection and persistence. We identified a number of genes encoding potential virulence factors, such as type IV fimbriae and surface polysaccharides. Analysis of the genome confirmed that H. parasuis is naturally competent, as genes related to DNA uptake are present. A nine-mer DNA uptake signal sequence (ACAAGCGGT, identical to that found in Actinobacillus pleuropneumoniae and Mannheimia haemolytica, followed by similar downstream motifs, was identified in the SH0165 genome. Genomic and phylogenetic comparisons with other Pasteurellaceae species further indicated that H. parasuis was closely related to another swine pathogenic bacteria A. pleuropneumoniae. The comprehensive genetic analysis presented here provides a foundation for future research on the metabolism, natural competence and virulence of H. parasuis.

Inhibition of the early stage of Salmonella enterica serovar Enteritidis biofilm development on stainless steel by cell-free supernatant of a Hafnia alvei culture.

Science.gov (United States)

Chorianopoulos, Nikos G; Giaouris, Efstathios D; Kourkoutas, Yiannis; Nychas, George-John E

2010-03-01

Compounds present in Hafnia alvei cell-free culture supernatant cumulatively negatively influence the early stage of biofilm development by Salmonella enterica serovar Enteritidis on stainless steel while they also reduce the overall metabolic activity of S. Enteritidis planktonic cells. Although acylhomoserine lactones (AHLs) were detected among these compounds, the use of several synthetic AHLs was not able to affect the initial stage of biofilm formation by this pathogen.

Multi-locus variable-number tandem repeat profiling of Salmonella enterica serovar Typhi isolates from blood cultures and gallbladder specimens from Makassar, South-Sulawesi, Indonesia.

Directory of Open Access Journals (Sweden)

Mochammad Hatta

Full Text Available Multi-locus variable-number tandem repeat analysis differentiated 297 Salmonella enterica serovar Typhi blood culture isolates from Makassar in 76 genotypes and a single unique S. Typhi genotype was isolated from the cholecystectomy specimens of four patients with cholelithiasis. The high diversity in S. Typhi genotypes circulating in Makassar indicates that the number of carriers could be very large, which may complicate disease prevention and control.

Salmonella in the pork production chain and its impact on human health in the European Union.

Science.gov (United States)

Bonardi, S

2017-06-01

Salmonella spp. comprise the second most common food-borne pathogens in the European Union (EU). The role of pigs as carriers of Salmonella has been intensively studied both on farm and at slaughter. Salmonella infection in pigs may cause fever, diarrhoea, prostration and mortality. However, most infected pigs remain healthy carriers, and those infected at the end of the fattening period could pose a threat to human health. Contamination of pig carcasses can occur on the slaughter line, and it is linked to cross-contamination from other carcasses and the presence of Salmonella in the environment. Therefore, Salmonella serovars present on pig carcasses can be different from those detected in the same bathes on the farm. In recent years, S. Typhimurium, S. Derby and S. serotype 4,[5],12:i:- (a monophasic variant of S. Typhimurium) have been the most common serovars to be detected in pigs in EU countries, but S. Rissen, S. Infantis, S. Enteritidis and S. Brandenburg have also been reported. In humans, several cases of salmonellosis have been linked to the consumption of raw or undercooked pork and pork products. Among the main serovars of porcine origin detected in confirmed human cases, S. Typhimurium, the monophasic variant S. 4,[5],12:i:- and S. Derby are certainly the most important.

Sexually Transmitted Infections: Experience in a Multidisciplinary Clinic in a Tertiary Hospital (2010-2013).

Science.gov (United States)

Moreno-Ribera, N; Fuertes-de Vega, I; Blanco-Arévalo, J L; Bosch-Mestres, J; González-Cordón, A; Estrach-Panella, T; García-de Olalla, P; Alsina-Gibert, M

2016-04-01

The number of consultations for sexually transmitted infections (STIs) is increasing in Spain. The aim of this study was to describe and analyze the epidemiological, behavioral, clinical, and microbiological characteristics of patients registered at the STI unit of a tertiary hospital. This was a retrospective, single-center descriptive study carried out between 2010 and 2013 in a multidisciplinary unit specialized in STIs, situated in a tertiary hospital. Epidemiological, clinical, and behavioral data were gathered using a face-to-face interview and a standardized questionnaire. Samples were collected for microbiology analysis. The study included 546 patients: 96% were men, 41% had human immunodeficiency virus (HIV) infection, and 56% were men who have sex with men. The reasons for consultation were the following: urethritis; genital, anal, or perianal ulcers; proctitis; oral ulcers; sexual contact with a person with a known STI; and high-risk sexual contact. The most common microbiological diagnoses were Neisseria gonorrhoeae in urethritis, Treponema pallidum in genital and anal or perianal ulcers, and Chlamydia trachomatis lymphogranuloma venereum serovars in proctitis. The highest prevalences of the main STIs studied occurred in homosexual men with HIV infection. This study confirms the increase in the incidence of STIs in recent years and the epidemiological characteristics of the HIV/STI epidemic in Spain. Copyright © 2015 AEDV. Published by Elsevier España, S.L.U. All rights reserved.

Effects of cattle feeding regimen and soil management type on the fate of Escherichia coli O157:H7 and salmonella enterica serovar typhimurium in manure, manure-amended soil, and lettuce

NARCIS (Netherlands)

Franz, Eelco; van Diepeningen, Anne D; de Vos, Oscar J; van Bruggen, Ariena H C

2005-01-01

Survival of the green fluorescent protein-transformed human pathogens Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium was studied in a laboratory-simulated lettuce production chain. Dairy cows were fed three different roughage types: high-digestible grass silage plus maize

Effects of cattle feeding regimen and soil management type on the fate of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in manure, manure-amended soil, and lettuce

NARCIS (Netherlands)

Franz, E.; Diepeningen, van A.D.; Vos, de O.J.; Bruggen, van A.H.C.

2005-01-01

Survival of the green fluorescent protein-transformed human pathogens Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium was studied in a laboratory-simulated lettuce production chain. Dairy cows were fed three different roughage types: high-digestible grass silage plus maize

Immunological and molecular characterization of Leptospira interrogans isolated from a bovine foetus.

Science.gov (United States)

Monte, Leonardo Garcia; Ridieri, Karine Forster; Jorge, Sérgio; Oliveira, Natasha Rodrigues; Hartwig, Daiane Drawanz; Amaral, Marta Gonçalves; Hartleben, Cláudia Pinho; Dellagostin, Odir Antonio

2015-06-01

Cattle are commonly infected with pathogenic leptospires, and similarly to rodents, they excrete the bacteria in their urine and can transmit the pathogen from animal to animal or animal to human. Thus, surveillance and monitoring systems for detection of new Leptospira serovars are important for the control of leptospirosis. Here, we report the isolation of a spirochete from a stillborn bovine foetus and its characterization by immunological and molecular techniques. A variable number tandem repeat profile using seven discriminatory primers identified the spirochete as belonging to species Leptospira interrogans serogroup Australis serovar Muenchen. A phenotypic analysis using monoclonal antibodies (mAbs) against leptospiral membrane-associated proteins confirmed the expression of important virulence and pathogenicity factors (LipL32 and LigBrep). Out of 120 reference sera tested, 22 positive (36.66%) and 9 negative (15%) also reacted with the new isolate. Furthermore, the serovar Muenchen isolate was virulent in hamster model. The animal inoculated developed acute lethal infection characterized by hepatic, pulmonary and renal lesions. Local isolates exhibited unique characteristics that differed from those of reference strains; therefore, isolation of leptospires is useful in the surveillance of local pathogenic serovars. In conclusion, the data obtained from this study can contribute to the epidemiological understanding and control of leptospirosis in southern Brazil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Salmonella enterica serovar Typhimurium ΔmsbB triggers exacerbated inflammation in Nod2 deficient mice.

Directory of Open Access Journals (Sweden)

Anne-Kathrin Claes

Full Text Available The intracellular pathogen Salmonella enterica serovar Typhimurium causes intestinal inflammation characterized by edema, neutrophil influx and increased pro-inflammatory cytokine expression. A major bacterial factor inducing pro-inflammatory host responses is lipopolysaccharide (LPS. S. Typhimurium ΔmsbB possesses a modified lipid A, has reduced virulence in mice, and is being considered as a potential anti-cancer vaccine strain. The lack of a late myristoyl transferase, encoded by MsbB leads to attenuated TLR4 stimulation. However, whether other host receptor pathways are also altered remains unclear. Nod1 and Nod2 are cytosolic pattern recognition receptors recognizing bacterial peptidoglycan. They play important roles in the host's immune response to enteric pathogens and in immune homeostasis. Here, we investigated how deletion of msbB affects Salmonella's interaction with Nod1 and Nod2. S. Typhimurium Δ msbB-induced inflammation was significantly exacerbated in Nod2-/- mice compared to C57Bl/6 mice. In addition, S. Typhimurium ΔmsbB maintained robust intestinal colonization in Nod2-/- mice from day 2 to day 7 p.i., whereas colonization levels significantly decreased in C57Bl/6 mice during this time. Similarly, infection of Nod1-/- and Nod1/Nod2 double-knockout mice revealed that both Nod1 and Nod2 play a protective role in S. Typhimurium ΔmsbB-induced colitis. To elucidate why S. Typhimurium ΔmsbB, but not wild-type S. Typhimurium, induced an exacerbated inflammatory response in Nod2-/- mice, we used HEK293 cells which were transiently transfected with pathogen recognition receptors. Stimulation of TLR2-transfected cells with S. Typhimurium ΔmsbB resulted in increased IL-8 production compared to wild-type S. Typhimurium. Our results indicate that S. Typhimurium ΔmsbB triggers exacerbated colitis in the absence of Nod1 and/or Nod2, which is likely due to increased TLR2 stimulation. How bacteria with "genetically detoxified" LPS

Characterization and differential gene expression between two phenotypic phase variants in Salmonella enterica serovar Typhimurium.

Directory of Open Access Journals (Sweden)

Sheila K Patterson

Full Text Available Salmonella enterica serovar Typhimurium strain 798 has previously been shown to undergo phenotypic phase variation. One of the phenotypes expresses virulence traits such as adhesion, while the other phenotype does not. Phenotypic phase variation appears to correlate with the ability of this strain to cause persistent, asymptomatic infections of swine. A new method to detect cells in either phenotypic phase was developed using Evans Blue-Uranine agar plates. Using this new assay, rates of phenotypic phase variation were obtained. The rate of phase variation from non-adhesive to adhesive phenotype was approximately 10(-4 per cell per generation while phase variation from the adhesive to the non-adhesive phenotype was approximately 10(-6 per cell per generation. Two highly virulent S. Typhimurium strains, SL1344 and ATCC 14028, were also shown to undergo phase variation. However, while the rate from adhesive to non-adhesive phenotype was approximately the same as for strain 798, the non-adhesive to adhesive phenotype shift was 37-fold higher. Differential gene expression was measured using RNA-Seq. Eighty-three genes were more highly expressed by 798 cells in the adhesive phenotype compared to the non-adhesive cells. Most of the up-regulated genes were in virulence genes and in particular all genes in the Salmonella pathogenicity island 1 were up-regulated. When compared to the virulent strain SL1344, expression of the virulence genes was approximately equal to those up-regulated in the adhesive phenotype of strain 798. A comparison of invasive ability demonstrated that strain SL1344 was the most invasive followed by the adhesive phenotype of strain 798, then the non-adhesive phenotype of strain 798. The least invasive strain was ATCC 14028. The genome of strain 798 was sequenced and compared to SL1344. Both strains had very similar genome sequences and gene deletions could not readily explain differences in the rates of phase variation from non

Detección de proteínas de adhesión a fibronectina y colágeno presentes en Leptospira interrogans serovar Canicola

Directory of Open Access Journals (Sweden)

Gisele Reyes

2007-12-01

Full Text Available Como parte de los estudios encaminados a la obtención de una formulación vacunal por subunidades contra la leptospirosis humana, se describe la purificación y caracterización de las proteínas de unión a fibronectina y a colágeno en Leptospira interrogans. Las proteínas de la membrana externa fueron extraídas mediante la solubilización con Tritón X-114 y se aplicaron en una columna de afinidad de IgG AntiBSA-Sepharose 2B CL, para eliminar la BSA, contaminante principal del medio de cultivo en que crece el microorganismo. La muestra libre de BSA (no fijado se aplicó a una columna de afinidad de fibronectina Sepharose 4B-CNBr, que permitió la separación y detección de una fracción que contenía una proteína de unión a fibronectina presente en la cepa 87 de Leptospira interrogans serovar Canicola, cuyo peso molecular fue estimado en 40 kDa. La proteína aislada demostró ser antigénica y conservada en los serovares Canicola, Copenhageni y Mozdok, en el ensayo de inmunodetección utilizado en este estudio (Dot blot. Para ello se utilizaron sueros específicos obtenidos en ratas infectadas experimentalmente con cada serovar y una mezcla de sueros de humanos convalecientes de leptospirosis. Las proteínas de membrana externa solubilizadas con Tritón X-114, libres de BSA, fueron aplicadas también a una columna de afinidad colágeno-Sepharosa 4B-CNBr, que permitió la purificación de una proteína de unión a colágeno con un peso molecular de aproximadamente 25 kDa, la cual resultó ser antigénica frente a sueros de humanos convalecientes de la enfermedad. Ambas proteínas seleccionadas (40 kD y 25 kD podrían ser evaluadas como posibles inmunógenos en futuros estudios encaminados a la obtención de nuevos antígenos vacunales.

Safety and tolerability of a live oral Salmonella typhimurium vaccine candidate in SIV-infected nonhuman primates.

Science.gov (United States)

Ault, Alida; Tennant, Sharon M; Gorres, J Patrick; Eckhaus, Michael; Sandler, Netanya G; Roque, Annelys; Livio, Sofie; Bao, Saran; Foulds, Kathryn E; Kao, Shing-Fen; Roederer, Mario; Schmidlein, Patrick; Boyd, Mary Adetinuke; Pasetti, Marcela F; Douek, Daniel C; Estes, Jacob D; Nabel, Gary J; Levine, Myron M; Rao, Srinivas S

2013-12-02

Nontyphoidal Salmonella (NTS) serovars are a common cause of acute food-borne gastroenteritis worldwide and can cause invasive systemic disease in young infants, the elderly, and immunocompromised hosts, accompanied by high case fatality. Vaccination against invasive NTS disease is warranted where the disease incidence and mortality are high and multidrug resistance is prevalent, as in sub-Saharan Africa. Live-attenuated vaccines that mimic natural infection constitute one strategy to elicit protection. However, they must particularly be shown to be adequately attenuated for consideration of immunocompromised subjects. Accordingly, we examined the safety and tolerability of an oral live attenuated Salmonella typhimurium vaccine candidate, CVD 1921, in an established chronic simian immunodeficiency virus (SIV)-infected rhesus macaque model. We evaluated clinical parameters, histopathology, and measured differences in mucosal permeability to wild-type and vaccine strains. Compared to the wild-type S. typhimurium strain I77 in both SIV-infected and SIV-uninfected nonhuman primate hosts, this live-attenuated vaccine shows reduced shedding and systemic spread, exhibits limited pathological disease manifestations in the digestive tract, and induces low levels of cellular infiltration in tissues. Furthermore, wild-type S. typhimurium induces increased intestinal epithelial damage and permeability, with infiltration of neutrophils and macrophages in both SIV-infected and SIV-uninfected nonhuman primates compared to the vaccine strain. Based on shedding, systemic spread, and histopathology, the live-attenuated S. typhimurium strain CVD 1921 appears to be safe and well-tolerated in the nonhuman primate model, including chronically SIV-infected rhesus macaques. Copyright © 2013. Published by Elsevier Ltd.

Genomic Dissection of Travel-Associated Extended-Spectrum-Beta-Lactamase-Producing Salmonella enterica Serovar Typhi Isolates Originating from the Philippines: a One-Off Occurrence or a Threat to Effective Treatment of Typhoid Fever?

DEFF Research Database (Denmark)

Hendriksen, Rene S.; Leekitcharoenphon, Pimlapas; Mikoleit, Matthew

2015-01-01

One unreported case of extended-spectrum-beta-lactamase (ESBL)-producing Salmonella enterica serovar Typhi was identified, whole-genome sequence typed, among other analyses, and compared to other available genomes of S. Typhi. The reported strain was similar to a previously published strain harbo...

Understanding paratyphoid infection: study protocol for the development of a human model of Salmonella enterica serovar Paratyphi A challenge in healthy adult volunteers.

Science.gov (United States)

McCullagh, David; Dobinson, Hazel C; Darton, Thomas; Campbell, Danielle; Jones, Claire; Snape, Matthew; Stevens, Zoe; Plested, Emma; Voysey, Merryn; Kerridge, Simon; Martin, Laura B; Angus, Brian; Pollard, Andrew J

2015-06-16

This study will develop the first human challenge model of paratyphoid infection which may then be taken forward to evaluate paratyphoid vaccine candidates. Salmonella Paratyphi A is believed to cause a quarter of the estimated 20 million cases of enteric fever annually. Epidemiological evidence also suggests that an increasing proportion of the enteric fever burden is attributable to S. Paratyphi infection meriting further attention and interest in vaccine development. Assessment of paratyphoid vaccine efficacy in preclinical studies is complicated by the lack of a small animal model and the human-restricted nature of the infection. The use of experimental human infection in healthy volunteers provides an opportunity to address these problems in a cost-effective manner. Volunteers will ingest virulent S. Paratyphi A bacteria (NVGH308 strain) with a bicarbonate buffer solution to establish the infectious dose resulting in an 'attack rate' of 60-75%. Using an a priori decision-making algorithm, the challenge dose will be escalated or de-escalated to achieve the target attack rate, with the aim of reaching the study end point while exposing as few individuals as possible to infection. The attack rate will be determined by the proportion of paratyphoid infection in groups of 20 healthy adult volunteers, with infection being defined by one or more positive blood cultures (microbiological end point) and/or fever, defined as an oral temperature exceeding 38 °C sustained for at least 12 h (clinical end point); 20-80 participants will be required. Challenge participants will start a 2-week course of an oral antibiotic on diagnosis of infection, or after 14 days follow-up. The strict eligibility criterion aims to minimise risk to participants and their close contacts. Ethical approval has been obtained. The results will be disseminated in a peer-reviewed journal and presented at international congresses. NCT02100397. Published by the BMJ Publishing Group Limited. For

Attachment of Salmonella serovars and Listeria monocytogenes to stainless steel and plastic conveyor belts.

Science.gov (United States)

Veluz, G A; Pitchiah, S; Alvarado, C Z

2012-08-01

In poultry industry, cross-contamination due to processing equipment and contact surfaces is very common. This study examined the extent of bacterial attachment to 6 different types and design of conveyor belts: stainless steel-single loop, stainless steel-balance weave, polyurethane with mono-polyester fabric, acetal, polypropylene mesh top, and polypropylene. Clean conveyor belts were immersed separately in either a cocktail of Salmonella serovars (Salmonella Typhimurium and Salmonella Enteritidis) or Listeria monocytogenes strains (Scott A, Brie 1, ATCC 6744) for 1 h at room temperature. Soiled conveyor chips were dipped in poultry rinses contaminated with Salmonella or Listeria cocktail and incubated at 10°C for 48 h. The polyurethane with mono-polyester fabric conveyor belt and chip exhibited a higher (Pconveyor belt attached a lower (Pconveyor belts exhibited stronger bacterial adhesion compared with stainless steel. The result suggests the importance of selecting the design and finishes of conveyor belt materials that are most resistant to bacterial attachment.

Approach to lymphogranuloma venereum.

Science.gov (United States)

O'Byrne, Patrick; MacPherson, Paul; DeLaplante, Stephane; Metz, Gila; Bourgault, Andree

2016-07-01

To review the literature about lymphogranuloma venereum (LGV) and to provide an overview and discussion of practice guidelines. The terms Chlamydia trachomatis and lymphogranuloma venereum were searched separately in PubMed. Empirical studies, practice reviews, and clinical guidelines were included. All reference lists were reviewed for additional articles. Since 2003, there has been a resurgence of LGV among men who have sex with men in many Western countries, including Canada. Although LGV is a serovar of Chlamydia trachomatis (serovar L), it can invade regional lymph nodes, and consequently presents with different symptoms than the other subtypes of chlamydia (serovars A through K). Specifically, LGV transitions through 3 phases: a painless papule or ulcer at the site of inoculation; invasion of the regional lymph nodes, which can present with an inguinal or rectal syndrome; and irreversible destruction of lymph tissue. In contrast, chlamydia serovars A to K exclusively produce superficial mucosal infections. Lymphogranuloma venereum also requires a different treatment regimen than other chlamydia serovars. In light of the current resurgence of LGV, its unique symptoms and clinical course, and its requirement for a different treatment than other chlamydia serovars, it is important for primary care providers to recognize when LGV should be included as an appropriate differential diagnosis. Copyright© the College of Family Physicians of Canada.

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

Science.gov (United States)

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

2012-04-01

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

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

Science.gov (United States)

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

2016-04-01

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

Salmonella Enterica Serovar Typhimurium BipA Exhibits Two Distinct Ribosome Binding Modes

Energy Technology Data Exchange (ETDEWEB)

deLivron, M.; Robinson, V

2008-01-01

BipA is a highly conserved prokaryotic GTPase that functions to influence numerous cellular processes in bacteria. In Escherichia coli and Salmonella enterica serovar Typhimurium, BipA has been implicated in controlling bacterial motility, modulating attachment and effacement processes, and upregulating the expression of virulence genes and is also responsible for avoidance of host defense mechanisms. In addition, BipA is thought to be involved in bacterial stress responses, such as those associated with virulence, temperature, and symbiosis. Thus, BipA is necessary for securing bacterial survival and successful invasion of the host. Steady-state kinetic analysis and pelleting assays were used to assess the GTPase and ribosome-binding properties of S. enterica BipA. Under normal bacterial growth, BipA associates with the ribosome in the GTP-bound state. However, using sucrose density gradients, we demonstrate that the association of BipA and the ribosome is altered under stress conditions in bacteria similar to those experienced during virulence. The data show that this differential binding is brought about by the presence of ppGpp, an alarmone that signals the onset of stress-related events in bacteria.

Diverse Secreted Effectors Are Required for Salmonella Persistence in a Mouse Infection Model

Energy Technology Data Exchange (ETDEWEB)

Kidwai, Afshan S.; Mushamiri, Ivy T.; Niemann, George; Brown, Roslyn N.; Adkins, Joshua N.; Heffron, Fred

2013-08-12

Salmonella enterica serovar Typhimurium causes typhoid-like disease in mice and is a model of typhoid fever in humans. One of the hallmarks of typhoid is persistence, the ability of the bacteria to survive in the host weeks after infection. Virulence factors called effectors facilitate this process by direct transfer to the cytoplasm of infected cells thereby subverting cellular processes. Secretion of effectors to the cell cytoplasm takes place through multiple routes, including two separate type III secretion (T3SS) apparati as well as outer membrane vesicles. The two T3SS are encoded on separate pathogenicity islands, SPI-1 and -2, with SPI-1 more strongly associated with the intestinal phase of infection, and SPI-2 with the systemic phase. Both T3SS are required for persistence, but the effectors required have not been systematically evaluated. In this study, mutations in 48 described effectors were tested for persistence. We replaced each effector with a specific DNA barcode sequence by allelic exchange and co-infected with a wild-type reference to calculate the ratio of wild-type parent to mutant at different times after infection. The competitive index (CI) was determined by quantitative PCR in which primers that correspond to the barcode were used for amplification. Mutations in all but seven effectors reduced persistence demonstrating that most effectors were required. One exception was CigR, a recently discovered effector that is widely conserved throughout enteric bacteria. Deletion of cigR increased lethality, suggesting that it may be an anti-virulence factor. The fact that almost all Salmonella effectors are required for persistence argues against redundant functions. This is different from effector repertoires in other intracellular pathogens such as Legionella.

Larval gut pH profile in pestiferous .i.Chironomus crassicaudatus./i. and .i.Glyptotendipes paripes./i. (Chironomidae: Diptera) in reference to the toxicity potential of .i.Bacillus thuringiensis./i. serovar .i.israelensis./i

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Lobinske, R.J.; Yaqub, A.; Ali, A.

2007-01-01

Roč. 23, č. 3 (2007), s. 355-358 ISSN 8756-971X Institutional research plan: CEZ:AV0Z60660521 Keywords : chironomidae larvae * gut pH * Bacillus thuringiensis serovar israelensis Subject RIV: EH - Ecology, Behaviour Impact factor: 0.706, year: 2007

A suspected case of lymphogranuloma venereum (LGV) suggests underdiagnosed LGV infection among Slovenian men who have sex with men.

Science.gov (United States)

Mlakar, Boštjan; Ramšak, Ana

2016-06-01

Lymphogranuloma venereum (LGV) is sexually transmitted infection caused by serovars of Chlamydia trachomatis, mostly seen among HIV-positive men who have sex with men. The first three reports of possible LGV in Slovenia were from April to June 2015, followed by a confirmed case of LGV in August 2015. We present the case of an HIV-positive MSM that presented with an anorectal abscess, discharge, lymphadenopathy, and unusual perianal plaque. Gonococcal proctitis was assumed and he received empirical antibiotic treatment, after which only intermittent improvement occurred. After a positive test result for chlamydial infection, but without a response to azithromycin treatment, LGV was suspected. Treatment according to the guidelines was introduced. When doxycycline therapy started, rapid improvement was observed, and it was therefore assumed that the LGV infection had been successfully treated. Two similar cases with an unusual anorectal presentation and an excellent response to antibiotic therapy for LGV were observed at the same center shortly thereafter. While pointing out possible delays and limitations in diagnostic procedures at self-pay facilities, the need for better access to high quality STI management in public and in private services is emphasized. Enhanced surveillance and testing guidelines could reveal a hidden LGV epidemic among MSM in Slovenia.

Expresión de la toxina Cry11Aa de Bacillus thuringiensis serovar. israelensis en Asticcacaulis excentricus, para el control de larvas acuáticas de dípteros de la familia Culicidae, vectores de enfermedades Expression of Bacillus thuringiensis serovar. israelensis toxins in Asticcacaulis excentricus to control dipteran larvae of vectors of diseases

Directory of Open Access Journals (Sweden)

Orduz Sergio

2004-07-01

Full Text Available Los genes cry de Bacillus thuringiensis codifican para un diverso grupo de proteínas formadoras de cristales que exhiben actividad insecticida contra larvas de dípteros, lepidópteros y coleópteros, entre otros. La efectividad de los insecticidas basados en formulaciones de proteínas de B. thuringiensis puede ser mejorada usando bacterias prostecadas acuáticas como portadoras alternativas de los genes cry, ya que no se sedimentan rápidamente; las proteínas expresadas en el citoplasma están protegidas de los rayos ultra violeta y, lo más importante, las larvas de los mosquitos se alimentan de ellas. Una cepa de referencia de Asticcacaulis excentricus fue transformada con el plásmido pSOD3, el cual contiene el gen que codifica para la proteína Cry1 1 Aa de B. thuringiensis serovar. israelensis. La expresión de la proteína recombinante fue evaluada por electroforesis de proteínas y por Western blot. El Western blot revelado con un anticuerpo policlonal anti-Cry1 1 Aa mostró una banda de 72 kDa correspondiente a la proteína Cry 11 Aa. La toxicidad de las cepas de A. excentricus transformadas fue evaluada en bioensayos con larvas de primer estadío del mosquito Culex quinquefasciatus. Se alcanzó un promedio de mortalidad del 50% de las larvas de primer instar a concentraciones de 23 ng/mL de la toxina. Otros bioensayos indican que A. excentricus recombinante es tóxica para larvas de primer instar de las especies Aedes aegypti y Anopheles albimanus. Los ensayos de flotabilidad indican que A. excentricus no sedimenta hasta pasados 7 días, mientras que B. thuringiensis serovar. israelensis sedimenta al cabo de algunas horas. Palabras clave: Asticcacaulis excentricus, Bacillus thuringiensis, bacterias prostecadas, dengue, malaria.Bacillus thuringiensis cry genes encode for a diverse group of crystal-forming proteins that exhibit insecticidal activity towards dipteran, lepidopteran and coleopteran larvae. The effectiveness of

Independent inactivation of arginine decarboxylase genes by nonsense and missense mutations led to pseudogene formation in Chlamydia trachomatis serovar L2 and D strains

Directory of Open Access Journals (Sweden)

Graham David E

2009-07-01

Full Text Available Abstract Background Chlamydia have reduced genomes that reflect their obligately parasitic lifestyle. Despite their different tissue tropisms, chlamydial strains share a large number of common genes and have few recognized pseudogenes, indicating genomic stability. All of the Chlamydiaceae have homologs of the aaxABC gene cluster that encodes a functional arginine:agmatine exchange system in Chlamydia (Chlamydophilapneumoniae. However, Chlamydia trachomatis serovar L2 strains have a nonsense mutation in their aaxB genes, and C. trachomatis serovar A and B strains have frameshift mutations in their aaxC homologs, suggesting that relaxed selection may have enabled the evolution of aax pseudogenes. Biochemical experiments were performed to determine whether the aaxABC genes from C. trachomatis strains were transcribed, and mutagenesis was used to identify nucleotide substitutions that prevent protein maturation and activity. Molecular evolution techniques were applied to determine the relaxation of selection and the scope of aax gene inactivation in the Chlamydiales. Results The aaxABC genes were co-transcribed in C. trachomatis L2/434, during the mid-late stage of cellular infection. However, a stop codon in the aaxB gene from this strain prevented the heterologous production of an active pyruvoyl-dependent arginine decarboxylase. Replacing that ochre codon with its ancestral tryptophan codon rescued the activity of this self-cleaving enzyme. The aaxB gene from C. trachomatis D/UW-3 was heterologously expressed as a proenzyme that failed to cleave and form the catalytic pyruvoyl cofactor. This inactive protein could be rescued by replacing the arginine-115 codon with an ancestral glycine codon. The aaxC gene from the D/UW-3 strain encoded an active arginine:agmatine antiporter protein, while the L2/434 homolog was unexpectedly inactive. Yet the frequencies of nonsynonymous versus synonymous nucleotide substitutions show no signs of relaxed

Genomic Signature of Multidrug-Resistant Salmonella enterica Serovar Typhi Isolates Related to a Massive Outbreak in Zambia between 2010 and 2012

DEFF Research Database (Denmark)

Hendriksen, Rene S.; Leekitcharoenphon, Pimlapas; Lukjancenko, Oksana

2015-01-01

). The isolates belonged to MLST ST1 and a new variant of the haplotype, H58B. Most isolates contained a chromosomally translocated region containing seven antimicrobial resistance genes, catA1, blaTEM-1, dfrA7, sul1, sul2, strA, and strB, and fragments of the incompatibility group Q1 (IncQ1) plasmid replicon......Retrospectively, we investigated the epidemiology of a massive Salmonella enterica serovar Typhi outbreak in Zambia during 2010 to 2012. Ninety-four isolates were susceptibility tested by MIC determinations. Whole-genome sequence typing (WGST) of 33 isolates and bioinformatic analysis identified...

A LigA three-domain region protects hamsters from lethal infection by Leptospira interrogans.

Directory of Open Access Journals (Sweden)

Mariana L Coutinho

2011-12-01

Full Text Available The leptospiral LigA protein consists of 13 bacterial immunoglobulin-like (Big domains and is the only purified recombinant subunit vaccine that has been demonstrated to protect against lethal challenge by a clinical isolate of Leptospira interrogans in the hamster model of leptospirosis. We determined the minimum number and location of LigA domains required for immunoprotection. Immunization with domains 11 and 12 was found to be required but insufficient for protection. Inclusion of a third domain, either 10 or 13, was required for 100% survival after intraperitoneal challenge with Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130. As in previous studies, survivors had renal colonization; here, we quantitated the leptospiral burden by qPCR to be 1.2×10(3 to 8×10(5 copies of leptospiral DNA per microgram of kidney DNA. Although renal histopathology in survivors revealed tubulointerstitial changes indicating an inflammatory response to the infection, blood chemistry analysis indicated that renal function was normal. These studies define the Big domains of LigA that account for its vaccine efficacy and highlight the need for additional strategies to achieve sterilizing immunity to protect the mammalian host from leptospiral infection and its consequences.

Comparative study of the protective capacity against Salmonella infection between probiotic and nonprobiotic Lactobacilli.

Science.gov (United States)

Castillo, N A; de Moreno de LeBlanc, A; M Galdeano, C; Perdigón, G

2013-03-01

To investigate the immunoprotective ability of three Lactobacilli strains against Salmonella enterica serovar Typhimurium in a mouse model. To identify the probiotic properties involved in the protection against infection caused by this pathogen. The immunomodulatory effect of three different lactobacilli strains: Lactobacillus (Lact.) casei CRL 431 (probiotic bacterium), Lact. delbrueckii subsp. bulgaricus CRL 423 (Lact. bulgaricus) and Lact.acidophilus CRL 730 was compared using a mouse model of Salmonella infection. Lactobacillus casei continuous administration improved animal survival, diminished pathogen spreading outside the intestine, attenuated the intestinal inflammation, modulated cytokine profile previous and postinfection and increased the expression and secretion of IgA in the gut. Additionally, the administration of this lactobacilli increased peritoneal, Peyer's patches and spleen macrophages' phagocytic activity in healthy mice and monocyte chemotactic protein (MCP-1) released by intestinal epithelial cells in an in vitro assay. Although Lact. acidophilus increased the number of IgA-secreting cells previous and postinfection, and Lact. bulgaricus increased MCP-1 released by intestinal epithelial cells and the phagocytic activity of macrophages, these effects alone were not enough to confer protection against Salmonella Typhimurium infection in mouse. Probiotic strain Lact. casei CRL 431 was the one that induced protection against Salmonella, by increasing the intestinal barrier function and by decreasing the local inflammatory response. Salmonella spp. constitutes an important agent of foodborne diseases in the world. Not all lactobacilli, even with some immunostimulating properties at gut level, can protect against Salmonella infection. Lactobacillus casei CRL 431, a probiotic bacterium, could be useful as an oral mucosal adjuvant of the immune system to improve gut health, especially in the prevention or amelioration of Salmonella infections. We

Intraspecies Competition for Niches in the Distal Gut Dictate Transmission during Persistent Salmonella Infection

Science.gov (United States)

Lam, Lilian H.; Monack, Denise M.

2014-01-01

In order to be transmitted, a pathogen must first successfully colonize and multiply within a host. Ecological principles can be applied to study host-pathogen interactions to predict transmission dynamics. Little is known about the population biology of Salmonella during persistent infection. To define Salmonella enterica serovar Typhimurium population structure in this context, 129SvJ mice were oral gavaged with a mixture of eight wild-type isogenic tagged Salmonella (WITS) strains. Distinct subpopulations arose within intestinal and systemic tissues after 35 days, and clonal expansion of the cecal and colonic subpopulation was responsible for increases in Salmonella fecal shedding. A co-infection system utilizing differentially marked isogenic strains was developed in which each mouse received one strain orally and the other systemically by intraperitoneal (IP) injection. Co-infections demonstrated that the intestinal subpopulation exerted intraspecies priority effects by excluding systemic S. Typhimurium from colonizing an extracellular niche within the cecum and colon. Importantly, the systemic strain was excluded from these distal gut sites and was not transmitted to naïve hosts. In addition, S. Typhimurium required hydrogenase, an enzyme that mediates acquisition of hydrogen from the gut microbiota, during the first week of infection to exert priority effects in the gut. Thus, early inhibitory priority effects are facilitated by the acquisition of nutrients, which allow S. Typhimurium to successfully compete for a nutritional niche in the distal gut. We also show that intraspecies colonization resistance is maintained by Salmonella Pathogenicity Islands SPI1 and SPI2 during persistent distal gut infection. Thus, important virulence effectors not only modulate interactions with host cells, but are crucial for Salmonella colonization of an extracellular intestinal niche and thereby also shape intraspecies dynamics. We conclude that priority effects and

Evaluation of a fluorescence-labelled oligonucleotide tide probe targeting 23S rRNA for in situ detection of Salmonella serovars in paraffin-embedded tissue sections and their rapid identification in bacterial smears

DEFF Research Database (Denmark)

Nordentoft, Steen; Christensen, H.; Wegener, Henrik Caspar

1997-01-01

with the probe. The probe did not hybridize to serovars from subspecies IIIa (S. arizonae) or to S. bongori. No cross-reaction to 64 other strains of the family Enterobacteriaceae or 18 other bacterial strains outside this family was observed. The probe was tested with sections of formalin-fixed, paraffin...

Isolation of Salmonella enterica and serologic reactivity to Leptospira interrogans in opossums (Didelphis virginiana from Yucatán, México Aislamiento de Salmonella enterica y reactividad serológica a Leptospira interrogans en tlacuaches (Didelphis virginiana de Yucatán, México

Directory of Open Access Journals (Sweden)

Hugo Antonio RUIZ-PIÑA

2002-07-01

Full Text Available The presence of Salmonella enterica and serologic evidence of infection by Leptospira interrogans, were detected in the opossum Didelphis virginiana in a semi-urban locality of the Yucatán State, México. Ninety-one opossums were captured during the period April 1996 and May 1998. From a total of 17 feces samples, four Salmonella enterica subsp. enterica serotypes (Sandiego, Newport, Anatum, and Minnesota, and one Salmonella enterica subsp. arizonae serovar O44:Z4,Z23:- were isolated. Some opossums presented mixed infections. From 81 sera samples, four (4.9% were positive to antibodies to Leptospira serovars pomona and wolfii. Both animals infected with Salmonella enterica and those serologically positive to Leptospira interrogans were captured in peridomestic habitat. Opossums infected with Salmonella enterica, were captured in dry season, and those seropositive to Leptospira interrogans during the rainy season. The implications of infection and reactivity of these zoonotic pathogens in D. virginiana in the Yucatan state are briefly discussed.La presencia de Salmonella enterica y evidencia serológica de infección por Leptospira interrogans fueron detectadas en tlacuaches de la especie Didelphis virginiana capturados en una localidad semi-urbana del estado de Yucatán, México. Se capturaron 91 marsupiales durante el período de abril de 1996 a mayo de 1998. De un total de 17 muestras de heces, se aislaron cuatro serotipos de Salmonella enterica subsp. enterica (Sandiego, Newport, Anatum y Minnesota y una Salmonella enterica subsp. arizonae serovar O44:Z4,Z23:-. En algunos tlacuaches se registraron infecciones mixtas. De 81 muestras de suero, cuatro (4,9% presentaron reacciones positivas con los serovares pomona y wolffi, ambos pertenecientes al género Leptospira. Los tlacuaches con serología positiva fueron capturados en el hábitat peridomiciliar. Los animales infectados con Salmonella enterica fueron capturados en los períodos de seca y

Predicting adhesion and biofilm formation boundaries on stainless steel surfaces by five Salmonella enterica strains belonging to different serovars as a function of pH, temperature and NaCl concentration.

Science.gov (United States)

Moraes, Juliana O; Cruz, Ellen A; Souza, Enio G F; Oliveira, Tereza C M; Alvarenga, Verônica O; Peña, Wilmer E L; Sant'Ana, Anderson S; Magnani, Marciane

2018-05-26

This study aimed to assess the capability of 97 epidemic S. enterica strains belonging to 18 serovars to form biofilm. Five strains characterized as strong biofilm-producers, belonging to distinct serovars (S. Enteritidis 132, S. Infantis 176, S. Typhimurium 177, S. Heidelberg 281 and S. Corvallis 297) were assayed for adhesion/biofilm formation on stainless steel surfaces. The experiments were conducted in different combinations of NaCl (0, 2, 4, 5, 6, 8 and 10% w/v), pH (4, 5, 6 and 7) and temperatures (8 °C, 12 °C, 20 °C and 35 °C). Only adhesion was assumed to occur when S. enterica counts were ≥3 and biofilm formation was defined as when the counts were ≥5 log CFU/cm 2 . The binary responses were used to develop models to predict the probability of adhesion/biofilm formation on stainless steel surfaces by five strains belonging to different S. enterica serovars. A total of 99% (96/97) of the tested S. enterica strains were characterized as biofilm-producers in the microtiter plate assays. The ability to form biofilm varied (P biofilm-producers, 21% (20/96), 45% (43/96), and 35% (34/96) were weak, moderate and strong biofilm-producers, respectively. The capability for adhesion/biofilm formation on stainless steel surfaces under the experimental conditions studied varied among the strains studied, and distinct secondary models were obtained to describe the behavior of the five S. enterica tested. All strains showed adhesion at pH 4 up to 4% of NaCl and at 20 °C and 35 °C. The probability of adhesion decreased when NaCl concentrations were >8% and at 8 °C, as well as in pH values ≤ 5 and NaCl concentrations > 6%, for all tested strains. At pH 7 and 6, biofilm formation for S. Enteritidis, S. Infantis, S. Typhimurium, S. Heidelberg was observed up to 6% of NaCl at 35 °C and 20 °C. The predicted boundaries for adhesion were pH values biofilm formation, the predicted boundaries were pH values biofilm formation

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

Science.gov (United States)

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

2017-01-01

The aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect Salmonella spp., S . Enteritidis and S . Typhimurium in the meat samples. The prevalence of Salmonella spp., S . Enteritidis and S . Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of retail beef products tested were widely contaminated with multi-drug resistant (MDR) Salmonella and various virulence genes are present among the isolated Salmonella serovars.

ORF Alignment: NC_006905 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available GPACNLACRYCYYPQGETPVEKMNESTLEVFICRYIAAQPASAREINFVWQ 82 ... PFHILAKPIGPACNLACRYCYYPQGETPVEKMNESTLEVFIC...RYIAAQPASAREINFVWQ Sbjct: 1 ... PFHILAKPIGPACNLACRYCYYPQGETPVEKMNESTLEVFICRYIAAQPASAREINFVWQ 60 ... Query: 143 GS... ... Choleraesuis str. SC-B67] ... Length = 269 ... Query: 23 ... PFHILAKPI

A Naturally Occurring Deletion in FliE from Salmonella enterica Serovar Dublin Results in an Aflagellate Phenotype and Defective Proinflammatory Properties.

Science.gov (United States)

Sasías, Sebastián; Martínez-Sanguiné, Adriana; Betancor, Laura; Martínez, Arací; D'Alessandro, Bruno; Iriarte, Andrés; Chabalgoity, José A; Yim, Lucía

2018-01-01

Salmonella enterica serovar Dublin is adapted to cattle but is able to infect humans with high invasiveness. An acute inflammatory response at the intestine helps to prevent Salmonella dissemination to systemic sites. Flagella contribute to this response by providing motility and FliC-mediated signaling through pattern recognition receptors. In a previous work, we reported a high frequency (11 out of 25) of S Dublin isolates lacking flagella in a collection obtained from humans and cattle. The aflagellate strains were impaired in their proinflammatory properties in vitro and in vivo The aim of this work was to elucidate the underlying cause of the absence of flagella in S Dublin isolates. We report here that class 3 flagellar genes are repressed in the human aflagellate isolates, due to impaired secretion of FliA anti-sigma factor FlgM. This phenotype is due to an in-frame 42-nucleotide deletion in the fliE gene, which codes for a protein located in the flagellar basal body. The deletion is predicted to produce a protein lacking amino acids 18 to 31. The aflagellate phenotype was highly stable; revertants were obtained only when fliA was artificially overexpressed combined with several successive passages in motility agar. DNA sequence analysis revealed that motile revertants resulted from duplications of DNA sequences in fliE adjacent to the deleted region. These duplications produced a FliE protein of similar length to the wild type and demonstrate that amino acids 18 to 31 of FliE are not essential. The same deletion was detected in S Dublin isolates obtained from cattle, indicating that this mutation circulates in nature. Copyright © 2017 American Society for Microbiology.

Immunogenicity of Recombinant Proteins Consisting of Plasmodium vivax Circumsporozoite Protein Allelic Variant-Derived Epitopes Fused with Salmonella enterica Serovar Typhimurium Flagellin

Science.gov (United States)

Leal, Monica Teixeira Andrade; Camacho, Ariane Guglielmi Ariza; Teixeira, Laís Helena; Bargieri, Daniel Youssef; Soares, Irene Silva; Tararam, Cibele Aparecida

2013-01-01

A Plasmodium falciparum circumsporozoite protein (CSP)-based recombinant fusion vaccine is the first malaria vaccine to reach phase III clinical trials. Resistance to infection correlated with the production of antibodies to the immunodominant central repeat region of the CSP. In contrast to P. falciparum, vaccine development against the CSP of Plasmodium vivax malaria is far behind. Based on this gap in our knowledge, we generated a recombinant chimeric protein containing the immunodominant central repeat regions of the P. vivax CSP fused to Salmonella enterica serovar Typhimurium-derived flagellin (FliC) to activate the innate immune system. The recombinant proteins that were generated contained repeat regions derived from each of the 3 different allelic variants of the P. vivax CSP or a fusion of regions derived from each of the 3 allelic forms. Mice were subcutaneously immunized with the fusion proteins alone or in combination with the Toll-like receptor 3 (TLR-3) agonist poly(I·C), and the anti-CSP serum IgG response was measured. Immunization with a mixture of the 3 recombinant proteins, each containing immunodominant epitopes derived from a single allelic variant, rather than a single recombinant protein carrying a fusion of regions derived from each of 3 allelic forms elicited a stronger immune response. This response was independent of TLR-4 but required TLR-5/MyD88 activation. Antibody titers significantly increased when poly(I·C) was used as an adjuvant with a mixture of the 3 recombinant proteins. These recombinant fusion proteins are novel candidates for the development of an effective malaria vaccine against P. vivax. PMID:23863502

Development of a novel in-water vaccination protocol for DNA adenine methylase deficient Salmonella enterica serovar Typhimurium vaccine in adult sheep.

Science.gov (United States)

Mohler, V L; Heithoff, D M; Mahan, M J; Hornitzky, M A; Thomson, P C; House, J K

2012-02-14

Intensive livestock production is associated with an increased incidence of salmonellosis. The risk of infection and the subsequent public health concern is attributed to increased pathogen exposure and disease susceptibility due to multiple stressors experienced by livestock from farm to feedlot. Traditional parenteral vaccine methods can further stress susceptible populations and cause carcass damage, adverse reactions, and resultant increased production costs. As a potential means to address these issues, in-water delivery of live attenuated vaccines affords a low cost, low-stress method for immunization of livestock populations that is not associated with the adverse handling stressors and injection reactions associated with parenteral administration. We have previously established that in-water administration of a Salmonella enterica serovar Typhimurium dam vaccine conferred significant protection in livestock. While these experimental trials hold significant promise, the ultimate measure of the vaccine will not be established until it has undergone clinical testing in the field wherein environmental and sanitary conditions are variable. Here we show that in-water administration of a S. Typhimurium dam attenuated vaccine was safe, stable, and well-tolerated in adult sheep. The dam vaccine did not alter water consumption or vaccine dosing; remained viable under a wide range of temperatures (21-37°C); did not proliferate within fecal-contaminated trough water; and was associated with minimal fecal shedding and clinical disease as a consequence of vaccination. The capacity of Salmonella dam attenuated vaccines to be delivered in drinking water to protect livestock from virulent Salmonella challenge offers an effective, economical, stressor-free Salmonella prophylaxis for intensive livestock production systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Host and Pathogen Copper-Transporting P-Type ATPases Function Antagonistically during Salmonella Infection.

Science.gov (United States)

Ladomersky, Erik; Khan, Aslam; Shanbhag, Vinit; Cavet, Jennifer S; Chan, Jefferson; Weisman, Gary A; Petris, Michael J

2017-09-01

Copper is an essential yet potentially toxic trace element that is required by all aerobic organisms. A key regulator of copper homeostasis in mammalian cells is the copper-transporting P-type ATPase ATP7A, which mediates copper transport from the cytoplasm into the secretory pathway, as well as copper export across the plasma membrane. Previous studies have shown that ATP7A-dependent copper transport is required for killing phagocytosed Escherichia coli in a cultured macrophage cell line. In this investigation, we expanded on these studies by generating Atp7a LysMcre mice, in which the Atp7a gene was specifically deleted in cells of the myeloid lineage, including macrophages. Primary macrophages isolated from Atp7a LysMcre mice exhibit decreased copper transport into phagosomal compartments and a reduced ability to kill Salmonella enterica serovar Typhimurium compared to that of macrophages isolated from wild-type mice. The Atp7a LysMcre mice were also more susceptible to systemic infection by S Typhimurium than wild-type mice. Deletion of the S Typhimurium copper exporters, CopA and GolT, was found to decrease infection in wild-type mice but not in the Atp7a LysMcre mice. These studies suggest that ATP7A-dependent copper transport into the phagosome mediates host defense against S Typhimurium, which is counteracted by copper export from the bacteria via CopA and GolT. These findings reveal unique and opposing functions for copper transporters of the host and pathogen during infection. Copyright © 2017 American Society for Microbiology.

An optimized, fast-to-perform mouse lung infection model with the human pathogen Chlamydia trachomatis for in vivo screening of antibiotics, vaccine candidates and modified host-pathogen interactions.

Science.gov (United States)

Dutow, Pavel; Wask, Lea; Bothe, Miriam; Fehlhaber, Beate; Laudeley, Robert; Rheinheimer, Claudia; Yang, Zhangsheng; Zhong, Guangming; Glage, Silke; Klos, Andreas

2016-03-01

Chlamydia trachomatis causes sexually transmitted diseases with infertility, pelvic inflammatory disease and neonatal pneumonia as complications. The duration of urogenital mouse models with the strict mouse pathogen C. muridarum addressing vaginal shedding, pathological changes of the upper genital tract or infertility is rather long. Moreover, vaginal C. trachomatis application usually does not lead to the complications feared in women. A fast-to-perform mouse model is urgently needed to analyze new antibiotics, vaccine candidates, immune responses (in gene knockout animals) or mutants of C. trachomatis. To complement the valuable urogenital model with a much faster and quantifiable screening method, we established an optimized lung infection model for the human intracellular bacterium C. trachomatis serovar D (and L2) in immunocompetent C57BL/6J mice. We demonstrated its usefulness by sensitive determination of antibiotic effects characterizing advantages and limitations achievable by early or delayed short tetracycline treatment and single-dose azithromycin application. Moreover, we achieved partial acquired protection in reinfection with serovar D indicating usability for vaccine studies, and showed a different course of disease in absence of complement factor C3. Sensitive monitoring parameters were survival rate, body weight, clinical score, bacterial load, histological score, the granulocyte marker myeloperoxidase, IFN-γ, TNF-α, MCP-1 and IL-6. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prevalence, risk factors and antimicrobial resistance of Salmonella diarrhoeal infection among children in Thi-Qar Governorate, Iraq.

Science.gov (United States)

Harb, A; O'Dea, M; Hanan, Z K; Abraham, S; Habib, I

2017-12-01

We conducted a hospital-based cross-sectional study among children aged Salmonella infection. From 320 diarrhoea cases enrolled between March and August 2016, 33 (10·3%, 95% confidence interval (CI) 8·4-12·4) cases were stool culture-positive for non-typhoidal Salmonella enterica. The most commonly identified serovar was Typhimurium (54%). Multivariable logistic regression analysis indicated that the odds of Salmonella infection in children from households supplied by pipe water was 4·7 (95% CI 1·6-13·9) times higher compared with those supplied with reverse osmosis treated water. Similarly, children from households with domestic animals were found to have a higher odds (OR 10·5; 95% CI 3·8-28·4) of being Salmonella stool culture-positive. The likelihood of Salmonella infection was higher (OR 3·9; 95% CI 1·0-6·4) among children belonging to caregiver with primary vs. tertiary education levels. Lower odds (OR 0·4; 95% CI 0·1-0·9) of Salmonella infection were associated with children exclusively breast fed as compared with those exclusively bottle fed. Salmonella infection was three times lower (95% CI 0·1-0·7) in children belonging to caregiver who reported always washing hands after cleaning children following defecation, vs. those belonging to caregivers who did not wash hands. The antimicrobial resistance profile by disc diffusion revealed that non-susceptibility to tetracycline (78·8%), azithromycin (66·7%) and ciprofloxacin (57·6%) were the most commonly seen, and 84·9% of Salmonella isolates were classified as multi-drug resistant. This is the first study on prevalence and antimicrobial resistance of Salmonella infection among children in this setting. This work provides specific epidemiological data which are crucial to understand and combat paediatric diarrhoea in Iraq.

Detection of reactive canines to Leptospira in Campeche City, Mexico Detección de caninos reaccionantes a Leptospira en la ciudad de Campeche, México

Directory of Open Access Journals (Sweden)

Selene del C Blum Domínguez

2013-03-01

Full Text Available Leptospira reactivity in stray and household dogs in Campeche as well as associated risk factors to the seropositivity in household dogs have been herein determined. The survey included 323 dogs, 142 of which were stray dogs and 181 household dogs. Nine Leptospira interrogans serovars were tested by the microagglutination test. Reactivity was 21.3 % (69/323, 17.2 % corresponded to household dogs and 26.7 % to stray dogs. Leptospira Canicola (29 %, Leptospira Hardjo (22.58 %, and Leptospira Icterohaemorrhagiae (16.12 % were the most common serovars reacting against the serum of household animals, while Leptospira Canicola (15.78 %, Leptospira Icterohaemorrhagiae (13.15 %, and Leptospira Pomona (7.89 % were those reacting in stray dogs. Results showed that all dogs have been in contact with different Leptospira serovars and outdoor exposure is the main infection risk factor.

Observation of a cytopathogenic effect on cell lines used for routine viral cultures led to the diagnosis of lymphogranuloma venereum.

Science.gov (United States)

Busson, Laurent; Crucitti, Tania; De Foor, Marc; Van den Wijngaert, Sigi; Vandenberg, Olivier

2013-08-01

This article reports the fortuitous recovery of nine Chlamydia trachomatis serovar L strains in cell cultures (Vero and LLC-MK(2) cell line) designed for viral culture. Nine ano-genital swabs were inoculated on confluent Vero, MRC5 and LLC-MK(2) cell cultures. They were collected from HIV-positive patients who were primarily men who have sex with men (MSM) presenting ulcerations that mimicked herpes simplex infections. A cytopathogenic effect was observed on Vero and LLC-MK(2) cells on day 14. The presence of C trachomatis serovar L in the cell lines was confirmed by Real Time-PCR. C trachomatis serovar L can grow on Vero and LLC-MK(2) cell lines designed for viral cultures. Lymphogranuloma venereum must be considered as a differential diagnosis for herpes-like lesions, particularly in MSM with high-risk behaviours.

Broilers with low serum Mannose-binding Lectin show increased faecal shedding of Salmonella enterica serovar Montevideo

DEFF Research Database (Denmark)

Ulrich-Lynge, Sofie Louise; Juul-Madsen, Helle Risdahl; Kjærup, Rikke Brødsgaard

2016-01-01

. enterica serovar Montevideo. The chickens were divided into two groups based on polymorphisms in their MBL promoter region, designated L/L for low serum concentrations of MBL and L/H for medium serum concentrations of MBL. A semi-quantitative real-time PCR method for detection of Salmonella in cloacal...... swabs was used, the log10 CFU quantification was based on a standard curve from artificially spiked cloacal swab samples pre-incubated for 8 h with known concentrations of Salmonella ranging from 101 to 106 CFU/swabs, with an obtained amplification efficiency of 102% and a linear relationship between...... the semi-quantitative real-time PCR method from L/L chickens than from the L/H chickens at week 5 pi. These results indicate that genetically determined basic levels of MBL may influence S. Montevideo susceptibility....

Immunogenicity of a Live Recombinant Salmonella enterica Serovar Typhimurium Vaccine Expressing pspA in Neonates and Infant Mice Born from Naïve and Immunized Mothers▿ †

OpenAIRE

Shi, Huoying; Wang, Shifeng; Roland, Kenneth L.; Gunn, Bronwyn M.; Curtiss, Roy

2010-01-01

We are developing a Salmonella vectored vaccine to prevent infant pneumonia and other diseases caused by Streptococcus pneumoniae. One prerequisite for achieving this goal is to construct and evaluate new recombinant attenuated Salmonella vaccine (RASV) strains suitable for use in neonates and infants. Salmonella enterica serovar Typhimurium strain χ9558(pYA4088) specifies delivery of the pneumococcal protective antigen PspA and can protect adult mice from challenge with S. pneumoniae. This s...

Optimization of inactivated H5N9 highly pathogenic avian influenza vaccine and inactivated Salmonella enterica serovar Typhimurium vaccine with antigen dose and prime-boost regimen in domestic ducks.

Science.gov (United States)

Yuk, Seong-Su; To, Eredene-Ochir; Kwon, Jung-Hoon; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Jei-Hyun; Gwon, Gyeong-Bin; Song, Chang-Seon

2017-09-01

Owing to the increase in the number of diseases affecting ducks and the demand for food safety by consumers, vaccination has become one of the factors that influence duck meat productivity. The highly pathogenic avian influenza (HPAI) virus is one of the most prevalent and causes one of the most lethal diseases in domestic ducks, and Salmonella enterica serovar Typhimurium is a food-borne pathogen persistent in the domestic duck population. To better understand the optimal usage of HPAI and S. enterica serovar Typhimurium vaccines, we aimed to determine antigen dose, oil and gel adjuvant usage with prime-boost regimen, and vaccination age, inducing the best immune response in ducks, without an effect on body weight gain. In the case of the inactivated H5N9 vaccine, a single dose of vaccine was inadequate to induce proper antibody titer when administered to day-old ducks, which necessitates boost vaccination. Administration of the oil-adjuvanted H5N9 vaccine administration in day-old and 2-week-old ducks resulted in a lower body weight at the time of slaughtering, compared to that of gel-adjuvanted H5N9 vaccine. However, gel-adjuvanted H5N9 vaccine failed to induce proper immune response to an extent recommend by OIE-World Organization for Animal Health. In the case of the Salmonella enterica serovar Typhimurium vaccine, a moderate or low dose of vaccine was appropriate for day-old ducks receiving the gel prime-oil boost vaccination. Single vaccination with oil adjuvants affects the mean body weight of 7-week-old ducks, suggesting that the gel adjuvant is more suitable for meat production. We expect that the use of adjuvants in a prime-boost regimen and at antigen doses set in this study will be helpful to maximize body weight in the case of domestic duck production at the actual farm site. © 2017 Poultry Science Association Inc.

First detection and characterization of Salmonella spp. in poultry and swine raised in backyard production systems in central Chile.

Science.gov (United States)

Alegria-Moran, R; Rivera, D; Toledo, V; Moreno-Switt, A I; Hamilton-West, C

2017-11-01

Little is known about Salmonella serovars circulating in backyard poultry and swine populations worldwide. Backyard production systems (BPS) that raise swine and/or poultry are distributed across Chile, but are more heavily concentrated in central Chile, where industrialized systems are in close contact with BPS. This study aims to detect and identify circulating Salmonella serovars in poultry and swine raised in BPS. Bacteriological Salmonella isolation was carried out for 1744 samples collected from 329 BPS in central Chile. Faecal samples were taken from swine, poultry, geese, ducks, turkeys and peacocks, as well as environmental faecal samples. Confirmation of Salmonella spp. was performed using invA-polymerase chain reaction (PCR). Identification of serovars was carried out using a molecular serotyping approach, where serogroups were confirmed by a multiplex PCR of Salmonella serogroup genes for five Salmonella O antigens (i.e., D, B, C1, C2-C3, and E1), along with two PCR amplifications, followed by sequencing of fliC and fljB genes. A total of 25 samples (1·4% of total samples) from 15 BPS (4·6 % of total sampled BPS) were found positive for Salmonella. Positive samples were found in poultry (chickens and ducks), swine and environmental sources. Molecular prediction of serovars on Salmonella isolated showed 52·0% of S. Typhimurium, 16·0% of S. Infantis, 16·0% S. Enteritidis, 8·0% S. Hadar, 4·0% S. Tennessee and 4·0% S. Kentucky. Poor biosecurity measures were found on sampled BPS, where a high percentage of mixed confinement systems (72·8%); and almost half of the sampled BPS with improper management of infected mortalities (e.g. selling the carcasses of infected animals for consumption). Number of birds other than chickens (P = 0·014; OR = 1·04; IC (95%) = 1·01-1·07), mixed productive objective (P = 0·030; OR = 5·35; IC (95%) = 1·24-27·59) and mixed animal replacement origin (P = 0017; OR = 5·19; IC (95%) = 1·35-20·47) were detected as

Profiling of Leptospira interrogans, L. santarosai, L. meyeri and L. borgpetersenii by SE-AFLP, PFGE and susceptibility testing--a continuous attempt at species and serovar differentiation.

Science.gov (United States)

Moreno, Luisa Z; Miraglia, Fabiana; Lilenbaum, Walter; Neto, José S F; Freitas, Julio C; Morais, Zenaide M; Hartskeerl, Rudy A; da Costa, Barbara L P; Vasconcellos, Silvio A; Moreno, Andrea M

2016-03-09

Leptospirosis is a widespread systemic zoonosis, considered as reemerging in certain developing countries. Although the cross agglutinin absorption test is still considered the standard method for Leptospira identification, it presents several disadvantages. The aim of this study was to characterize Leptospira spp. isolated from various hosts by genotyping and broth microdilution susceptibility testing in an attempt to differentiate Leptospira species, serogroups and serovars. Forty-seven isolates were studied. They were previously serotyped, and species confirmation was performed by 16S rRNA sequencing. Single-enzyme amplified fragment length polymorphism (SE-AFLP) and pulsed-field gel electrophoresis (PFGE) analysis enabled the distinction of L. interrogans from L. santarosai, L. meyeri and L. borgpetersenii in two main clusters. Among L. interrogans, it was possible to differentiate into two new clusters the serogroup Icterohaemorrhagiae from the serogroups Canicola and Pomona. L. santarosai isolates presented higher genetic variation than the other species in both techniques. Interestingly, the minimum inhibitory concentration (MIC) cluster analysis also provided Leptospira serogroup differentiation. Further studies are necessary regarding serovar Bananal isolates, as they presented the highest MIC values for most of the antimicrobials tested. All studied techniques successfully distinguished Leptospira species and serogroups. Despite being library-dependent methods, these approaches are less labor intensive and more economically viable, particularly SE-AFLP, and can be implemented in most reference laboratories worldwide to enable faster Leptospira typing.

The maternal serological response to intrauterine Ureaplasma sp. infection and prediction of risk of preterm birth

Directory of Open Access Journals (Sweden)

Demelza Jane Ireland

2014-12-01

Full Text Available Preterm birth (PTB associated with intrauterine infection and inflammation (IUI is the major cause of early PTB less than 32 weeks gestation. Ureaplasma sp. are common commensals of the urogenital tract in pregnancy and are the most commonly identified microorganism in amniotic fluid of preterm pregnancies. While we have an understanding of the causal relationship between intraamniotic infection, inflammation and PTB, we are still unable to explain why vaginal Ureaplasma colonization is tolerated in some women but causes PTB in others. It is now known that placental tissues are frequently colonized by bacteria even in apparently healthy pregnancies delivered at term; usually this occurs in the absence of a significant local inflammatory response. It appears, therefore, that the site, nature and magnitude of the immune response to infiltrating microorganisms is key in determining pregnancy outcome. Some evidence exists that the maternal serological response to Ureaplasma sp. colonization may be predictive of adverse pregnancy outcome, although issues such as the importance of virulence factors (serovars and the timing, magnitude and functional consequences of the immune response await clarification. This mini-review discusses the evidence linking the maternal immune response to risk of PTB and the potential applications of maternal serological analysis for predicting obstetric outcome.

Multi locus sequence typing of Chlamydiales: clonal groupings within the obligate intracellular bacteria Chlamydia trachomatis

NARCIS (Netherlands)

Pannekoek, Yvonne; Morelli, Giovanna; Kusecek, Barica; Morré, Servaas A.; Ossewaarde, Jacobus M.; Langerak, Ankie A.; van der Ende, Arie

2008-01-01

BACKGROUND: The obligate intracellular growing bacterium Chlamydia trachomatis causes diseases like trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Several serovars and genotypes have been identified, but these could not be linked to clinical disease or outcome.

Serological survey on Leptospira infection in slaughtered swine in North-Central Italy.

Science.gov (United States)

Bertelloni, F; Turchi, B; Vattiata, E; Viola, P; Pardini, S; Cerri, D; Fratini, F

2018-05-30

Swine can act as asymptomatic carriers of some Leptospira serovars. In this study, 1194 sera from 61 farms located in five different Regions of North-West Italy were collected from slaughtered healthy pigs. Presence of antibody against four Leptospira serovars was evaluated. Overall, 52.5% of analysed farms presented at least one positive animal and 34.4% presented at least one positive swine with titre ⩾1:400. A percentage of 16.6% sera was positive and 5.9% samples presented a positive titre ⩾1:400. Tuscany and Lombardy showed the highest percentage of positive farms (64.3% and 54.6%, respectively) and sera (28.5% and 13.3%, respectively), probably due to environmental conditions and potential risk factors, which promote maintenance and spreading of Leptospira in these areas. The main represented serogroups were Australis (21.3% positive farms, 8.2% positive sera) and Pomona (18.0% positive farms, 8.1% positive sera). In swine, these serogroups are the most detected worldwide; however, our results seem to highlight a reemerging of serogroup Pomona in pigs in investigated areas. A low percentage of sera (0.6%) scored positive to Canicola, leaving an open question on the role of pigs in the epidemiology of this serovar. Higher antibody titres were detected for serogroups Australis and Pomona. Swine leptospirosis is probably underestimated in Italy and could represent a potential risk for animal and human health.

Ocorrência de anticorpos contra Leptospira spp em cães de Teresina, Piauí, Brasil

Directory of Open Access Journals (Sweden)

Elís Rosélia Dutra de Freitas Siqueira Silva

2017-05-01

Full Text Available Leptospirosis is a systemic disease caused by the species of bacteria Leptospira spp., which affects human beings, domestic and wild animals. The present study searched the presence of antibodies against Leptospira spp. in the canine population of the city Teresina, Piauí, and the most common serovars. Blood samples from 425 stray dogs were collected in the local zoonosis center in Teresina from July 2010 to January 2012 and submitted to the Microscopic Seroagglutination Test (MAT. This study found an average infection rate of 17.41% (IC 95%; 13,8 – 21,0 by 11 different serovars; the four most frequent were Canicola (18.9%, Autumnalis (16.2%, Icterohaemorrhagiae (12.1%, and Butembo (12.1%. The questions raised in this study indicated the occurrence of Leptospira spp infection in dogs of Terezina- Piaui, Brazil.

Prevalence and antimicrobial resistance pattern of Salmonella in animal feed produced in Namibia.

Science.gov (United States)

Shilangale, Renatus P; Di Giannatale, Elisabetta; Chimwamurombe, Percy M; Kaaya, Godwin P

2012-01-01

The occurrence of Salmonella is a global challenge in the public health and food production sectors. Our study investigated the prevalence, serovar and antimicrobial susceptibility of strains of Salmonella serovars isolated from animal feed (meat-and-bone and blood meal) samples from two commercial abattoirs in Namibia. A total of 650 samples (n=650) were examined for the presence of Salmonella. Results showed that 10.9% (n=71) were positive for Salmonella. Of the Salmonella serovars isolated, S. Chester was the most commonly isolated serovar (19.7%), followed by S. Schwarzengrund at 12.7%. From the Salmonella isolates, 19.7% (n=14) were resistant to one or more of the antimicrobials (nalidixic acid, trimethoprim-sulfamethoxazole, sulfisoxazole, streptomycin and/or tetracycline), whereas 80.3% (n=57) were susceptible to all 16 antimicrobials tested. Resistance to sulfisoxazole and the trimethroprimsuflamethoxazole combination were the most common. The resistant isolates belonged to ten different Salmonella serovars. The susceptibility of most of the Salmonella isolated to the antimicrobials tested indicates that anti-microbial resistance is not as common and extensive in Namibia as has been reported in many other countries. It also appears that there is a range of antimicrobials available that are effective in managing Salmonella infections in Namibia. However, there is some evidence that resistance is developing and this will need further monitoring to ensure it does not become a problem.

High Leptospira seroprevalence in captive and wild-caught vervet monkeys ( Chlorocebus sabeus) on the Caribbean island of Saint Kitts.

Science.gov (United States)

Rajeev, Sreekumari; Conan, Anne; Pratt, Nicola; Beierschmitt, Amy; Palmour, Roberta

2017-11-01

Leptospirosis is a zoonotic disease of global importance. Very little information is available on Leptospira infection in nonhuman primates. We report herein a high seroprevalence (49.4%; 95% confidence interval: 41.6-57.2%) to Leptospira serovars in vervet monkeys ( Chlorocebus sabeus) on the Caribbean island of Saint Kitts. Monkeys bred in captivity ( n = 81) had a significantly higher seroprevalence compared to wild-caught monkeys ( n = 81; p Leptospira serovars and seroconversion occurs in wild and captive vervet monkeys on the Caribbean island of Saint Kitts. Further studies are warranted to better understand epidemiology, transmission, pathology, and possible reservoir status in this species.

Decreased erytrocyte osmotic fragility during canine leptospirosis Diminuição da fragilidade osmótica eritrocitária na leptospirose canina

Directory of Open Access Journals (Sweden)

Marcelo L. Santoro

1994-02-01

Full Text Available Erythrocyte osmotic fragility (EOF was carried out in nineteen dogs naturally infected by Leptospira interrogans serovar icterohaemorrhagiae/copenhagi. A decreased EOF was observed, suggesting a modification of erythrocyte components secondary to disturbances that occur during canine leptospirosis, such as renal damage and hepatic disease.A fragilidade osmótica eritrocitária foi estudada em dezenove cães infectados naturalmente pela Leptospira interrogans serovar icterohaemorrhagiae/copenhagi. Observou-se uma redução da fragilidade osmótica eritrocitária, sem a presença de anemia, possivelmente relacionada aos distúrbios hepato-renais que ocorrem nesta patologia.

[Construction and expression of recombinant Mycobacterium bovis BCG with the ompA-like membrane protein gene Loa22 of Leptospira interrogans serovar].

Science.gov (United States)

Li, Dao-kun; Bao, Lang; Zhang, Ying; Sun, Zhan

2010-03-01

To study the immunity of Loa22 from Leptospira interrogans serovar Lai strain 56601 by expressing its protein in BCG. Amplified the mature peptide of Loa22 gene from the genome of of Leptospira interrogans serovar Lai strain 56601 and constructed recombinant plasmid rpMV36l-1oa22 with the E. coli-BCG integrating shuttle plasmid pMV361 and the Loa22 mature peptide gene. The rpMV36l-1oa22 plasmid was transformed into BCG by electroporation. The rBCG bearing rpMV36l-1oa22 was induced by high temperature of 45 degrees C and expressed protein was identified by SDS-PAGE and Western Blotting. Fifth 6-week-old BALB/c mice were randomly divided into five groups, which were inoculated intraperitoneally two times at 0-day and 21-day with BCG, rBCG-pMV361, rI3CG-1oa22, Loa22 and killed whole-leptospires respectively. All animals were dislocated from cervical vertebra on the 14Ih day after the last immunization. The proliferative reaction of splenic lymphocyte in tuitro were tested by XTT. The rpMV36l-1oa22 plasmid was constructed successfully and transformed into BCG. The rBCG expressed a 19 X io specifical protein identified by SDS-PAGE and Western Blotting. The splenic lymphocyte proliferate activity (SI) in rBCG-ioa22 group in intro was significantly higher than those in BCG group and rBCG-pMV361 group. We explored the expressing feasibility of Loa22 in Mycobacterium bovis BCG. may therefore make further researches on the induction of protective immunity against human and animal leptospirosis.

Genomic presence of gadD1 glutamate decarboxylase correlates with the organization of ascB-dapE internalin cluster in Listeria monocytogenes.

Science.gov (United States)

Chen, Jianshun; Fang, Chun; Zheng, Tianlun; Zhu, Ningyu; Bei, Yijiang; Fang, Weihuan

2012-02-01

The ability to survive and proliferate in acidic environments is a prerequisite for the infection of Listeria monocytogenes. The glutamate decarboxylase (GAD) system is responsible for acid resistance, and three GAD homologs have been identified in L. monocytogenes: gadD1, gadD2, and gadD3. To examine whether GAD genes are specific to lineage, serovar, or certain subpopulation, we performed a systematic investigation on the prevalence of GAD genes in 164 L. monocytogenes. In contrast to gadD2 and gadD3 conserved in all L. monocytogenes strains, gadD1 was identified in 36.6% (60/164) of L. monocytogenes strains, including all serovar 1/2c and 68.5% (37/54) of serovar 1/2a strains, as well as a small fraction of serovar 1/2b (3.4%, 1/29) and lineage III (13.8%, 4/29) strains. All serovar 4b and lineage IV strains lacked this gene. According to the ascB-dapE structure, L. monocytogenes strains were classified into four subpopulations, carrying inlC2DE, inlGC2DE, inlGHE, or no internalin cluster, respectively. All L. monocytogenes strains with inlGC2DE or inlGHE pattern harbored gadD1, whereas those bearing inlC2DE or no internalin cluster between ascB and dapE lacked gadD1. In addition, other five non-monocytogenes Listeria species lacking ascB-dapE internalin cluster were gadD1-negative. Overall, the presence of gadD1 is not fully dependent on lineages or serovars but correlates with ascB-dapE internalin profiles, suggesting gadD1 might have co-evolved with the ascB-dapE internalin cluster in the primitive L. monocytogenes before divergence of serovars.

Drinking water from dug wells in rural ghana--salmonella contamination, environmental factors, and genotypes.

Science.gov (United States)

Dekker, Denise Myriam; Krumkamp, Ralf; Sarpong, Nimako; Frickmann, Hagen; Boahen, Kennedy Gyau; Frimpong, Michael; Asare, Renate; Larbi, Richard; Hagen, Ralf Matthias; Poppert, Sven; Rabsch, Wolfgang; Marks, Florian; Adu-Sarkodie, Yaw; May, Jürgen

2015-03-27

Salmonellosis is an important but neglected disease in sub-Saharan Africa. Food or fecal-oral associated transmissions are the primary cause of infections, while the role of waterborne transmission is unclear. Samples were collected from different dug wells in a rural area of Ghana and analyzed for contamination with bacteria, and with Salmonella in particular. In addition, temporal dynamics and riks factors for contamination were investigated in 16 wells. For all Salmonella isolates antibiotic susceptibility testing was performed, serovars were determined and strains from the same well with the same serovar were genotyped. The frequency of well water contamination with Gram-negative rod-shaped bacteria was 99.2% (n = 395). Out of 398 samples, 26 (6.5%) tested positive for Salmonella spp. The serovar distribution was diverse including strains not commonly isolated from clinical samples. Resistance to locally applied antibiotics or resistance to fluoroquinolones was not seen in the Salmonella isolates. The risk of Salmonella contamination was lower in wells surrounded by a frame and higher during the rainy season. The study confirms the overall poor microbiological quality of well water in a resource-poor area of Ghana. Well contamination with Salmonella poses a potential threat of infection, thus highlighting the important role of drinking water safety in infectious disease control.

Genotypic homogeneity of multidrug resistant S. Typhimurium infecting distinct adult and childhood susceptibility groups in Blantyre, Malawi.

Directory of Open Access Journals (Sweden)

Chisomo L Msefula

Full Text Available Nontyphoidal Salmonella (NTS serovars are a common cause of bacteraemia in young children and HIV-infected adults in Malawi and elsewhere in sub-Saharan Africa. These patient populations provide diverse host-immune environments that have the potential to drive bacterial adaptation and evolution. We therefore investigated the diversity of 27 multidrug resistant (MDR Salmonella Typhimurium strains isolated over 6 years (2002-2008 from HIV-infected adults and children and HIV-uninfected children. Sequence reads from whole-genome sequencing of these isolates using the Illumina GA platform were mapped to the genome of the laboratory strain S. Typhimurium SL1344 excluding homoplastic regions that contained prophage and insertion elements. A phylogenetic tree generated from single nucleotide polymorphisms showed that all 27 strains clustered with the prototypical MDR strain D23580. There was no clustering of strains based on host HIV status or age, suggesting that these susceptible populations acquire S. Typhimurium from common sources or that isolates are transmitted freely between these populations. However, 7/14 of the most recent isolates (2006/2008 formed a distinct clade that branched off 22 SNPs away from the cluster containing earlier isolates. These data suggest that the MDR bacterial population is not static, but is undergoing microevolution which might result in further epidemiology change.

The Maternal Serological Response to Intrauterine Ureaplasma sp. Infection and Prediction of Risk of Pre-Term Birth

Science.gov (United States)

Ireland, Demelza J.; Keelan, Jeffrey A.

2014-01-01

Pre-term birth (PTB) associated with intrauterine infection and inflammation (IUI) is the major cause of early PTB less than 32 weeks of gestation. Ureaplasma spp. are common commensals of the urogenital tract in pregnancy and are the most commonly identified microorganisms in amniotic fluid of pre-term pregnancies. While we have an understanding of the causal relationship between intra-amniotic infection, inflammation and PTB, we are still unable to explain why vaginal Ureaplasma sp. colonization is tolerated in some women but causes PTB in others. It is now known that placental tissues are frequently colonized by bacteria even in apparently healthy pregnancies delivered at term; usually this occurs in the absence of a significant local inflammatory response. It appears, therefore, that the site, nature, and magnitude of the immune response to infiltrating microorganisms are key in determining pregnancy outcome. Some evidence exists that the maternal serological response to Ureaplasma sp. colonization may be predictive of adverse pregnancy outcome, although issues such as the importance of virulence factors (serovars) and the timing, magnitude, and functional consequences of the immune response await clarification. This mini-review discusses the evidence linking the maternal immune response to risk of PTB and the potential applications of maternal serological analysis for predicting obstetric outcome. PMID:25538708

A second wave of Salmonella T3SS1 activity prolongs the lifespan of infected epithelial cells.

Directory of Open Access Journals (Sweden)

Ciaran E Finn

2017-04-01

Full Text Available Type III secretion system 1 (T3SS1 is used by the enteropathogen Salmonella enterica serovar Typhimurium to establish infection in the gut. Effector proteins translocated by this system across the plasma membrane facilitate invasion of intestinal epithelial cells. One such effector, the inositol phosphatase SopB, contributes to invasion and mediates activation of the pro-survival kinase Akt. Following internalization, some bacteria escape from the Salmonella-containing vacuole into the cytosol and there is evidence suggesting that T3SS1 is expressed in this subpopulation. Here, we investigated the post-invasion role of T3SS1, using SopB as a model effector. In cultured epithelial cells, SopB-dependent Akt phosphorylation was observed at two distinct stages of infection: during and immediately after invasion, and later during peak cytosolic replication. Single cell analysis revealed that cytosolic Salmonella deliver SopB via T3SS1. Although intracellular replication was unaffected in a SopB deletion mutant, cells infected with ΔsopB demonstrated a lack of Akt phosphorylation, earlier time to death, and increased lysis. When SopB expression was induced specifically in cytosolic Salmonella, these effects were restored to levels observed in WT infected cells, indicating that the second wave of SopB protects this infected population against cell death via Akt activation. Thus, T3SS1 has two, temporally distinct roles during epithelial cell colonization. Additionally, we found that delivery of SopB by cytosolic bacteria was translocon-independent, in contrast to canonical effector translocation across eukaryotic membranes, which requires formation of a translocon pore. This mechanism was also observed for another T3SS1 effector, SipA. These findings reveal the functional and mechanistic adaptability of a T3SS that can be harnessed in different microenvironments.

Removal of the phage-shock protein PspB causes reduction of virulence in Salmonella enterica serovar Typhimurium independently of NRAMP1.

Science.gov (United States)

Wallrodt, Inke; Jelsbak, Lotte; Thomsen, Line E; Brix, Lena; Lemire, Sébastien; Gautier, Laurent; Nielsen, Dennis S; Jovanovic, Goran; Buck, Martin; Olsen, John E

2014-06-01

The phage-shock protein (Psp) system is believed to manage membrane stress in all Enterobacteriaceae and has recently emerged as being important for virulence in several pathogenic species of this phylum. The core of the Psp system consists of the pspA-D operon and the distantly located pspG gene. In Salmonella enterica serovar Typhimurium (S. Typhimurium), it has recently been reported that PspA is essential for systemic infection of mice, but only in NRAMP1(+) mice, signifying that attenuation is related to coping with divalent cation starvation in the intracellular environment. In the present study, we investigated the contribution of individual psp genes to virulence of S. Typhimurium. Interestingly, deletion of the whole pspA-D set of genes caused attenuation in both NRAMP1(+) and NRAMP1(-) mice, indicating that one or more of the psp genes contribute to virulence independently of NRAMP1 expression in the host. Investigations of single gene mutants showed that knock out of pspB reduced virulence in both types of mice, while deletion of pspA only caused attenuation in NRAMP1(+) mice, and deletion of pspD had a minor effect in NRAMP1(-) mice, while deletions of either pspC or pspG did not affect virulence. Experiments addressed at elucidating the role of PspB in virulence revealed that PspB is dispensable for uptake to and intracellular replication in cultured macrophages and resistance to complement-induced killing. Furthermore, the Psp system of S. Typhimurium was dispensable during pIV-induced secretin stress. In conclusion, our results demonstrate that removal of PspB reduces virulence in S. Typhimurium independently of host NRAMP1 expression, demonstrating that PspB has roles in intra-host survival distinct from the reported contributions of PspA. © 2014 The Authors.

Compositional and Functional Differences in the Human Gut Microbiome Correlate with Clinical Outcome following Infection with Wild-Type Salmonella enterica Serovar Typhi.

Science.gov (United States)

Zhang, Yan; Brady, Arthur; Jones, Cheron; Song, Yang; Darton, Thomas C; Jones, Claire; Blohmke, Christoph J; Pollard, Andrew J; Magder, Laurence S; Fasano, Alessio; Sztein, Marcelo B; Fraser, Claire M

2018-05-08

Insights into disease susceptibility as well as the efficacy of vaccines against typhoid and other enteric pathogens may be informed by better understanding the relationship between the effector immune response and the gut microbiota. In the present study, we characterized the composition (16S rRNA gene profiling) and function (RNA sequencing [RNA-seq]) of the gut microbiota following immunization and subsequent exposure to wild-type Salmonella enterica serovar Typhi in a human challenge model to further investigate the central hypothesis that clinical outcomes may be linked to the gut microbiota. Metatranscriptome analysis of longitudinal stool samples collected from study subjects revealed two stable patterns of gene expression for the human gut microbiota, dominated by transcripts from either Methanobrevibacter or a diverse representation of genera in the Firmicutes phylum. Immunization with one of two live oral attenuated vaccines against S.  Typhi had minimal effects on the composition or function of the gut microbiota. It was observed that subjects harboring the methanogen-dominated transcriptome community at baseline displayed a lower risk of developing symptoms of typhoid following challenge with wild-type S.  Typhi. Furthermore, genes encoding antioxidant proteins, metal homeostasis and transport proteins, and heat shock proteins were expressed at a higher level at baseline or after challenge with S.  Typhi in subjects who did not develop symptoms of typhoid. These data suggest that functional differences relating to redox potential and ion homeostasis in the gut microbiota may impact clinical outcomes following exposure to wild-type S.  Typhi. IMPORTANCE S.  Typhi is a significant cause of systemic febrile morbidity in settings with poor sanitation and limited access to clean water. It has been demonstrated that the human gut microbiota can influence mucosal immune responses, but there is little information available on the impact of the human gut

Kejadian Leptospirosis pada Anjing di Daerah Istimewa Yogyakarta (CASE OF CANINE LEPTOSPIROSIS IN THE CITY OF YOGYAKARTA

Directory of Open Access Journals (Sweden)

Guntari Titik Mulyani

2017-09-01

Full Text Available Leptospirosis is a zoonotic disease, which is caused by Leptospira interrogans. The incidence of leptospirosis in dogs varies according to region and season, and is considered as emerging infectious diseases in humans. Clinical symptoms of leptospirosis in dogs vary greatly, some dogs are asymptomatic, with mild symptoms, and others progress to severe illness until death. The study aims to determine cases of canine leptospirosis in Yogyakarta, and identify the serovar that infect them. A total of 20 dogs without symptoms, with mild symptoms, to severe symptoms of leptospirosis were collected their serum and further tested using Microscopic Agglutination Test (MAT conducted at the Center for Veterinary Research (BBLitvet Bogor. History of vaccination is recorded as a consideration in interpreting the MAT results. The results showed that three out of the 20 samples were positive leptospirosis. Of the three positive samples, one was identified as serovar bataviae, another one as serovar bataviae and tarrasovi, and the last as serovar bataviae, tarrasovi, ichterohaemorrhagiae, canicola, celledoni, pyrogenes, cynopteri, and rachmati, respectively. The three dogs with leptospirosis showed similar clinical symptoms i.e. Anorexia, lethargy, and fever. It can be concluded that there are cases of canine leptospirosis in Yogyakarta which is predominantly caused by Leptospira interrogans serovar bataviae. ABSTRAK Leptospirosis adalah penyakit zoonosis, yang disebabkan oleh Leptospira interrogans. Kejadian leptospirosis pada anjing bervariasi menurut wilayah dan musim, dan dianggap sebagai penyakit menular yang muncul pada manusia. Gejala klinis leptospirosis pada anjing sangat bervariasi, beberapa anjing tanpa menunjukkan gejala, dengan gejala ringan, dan yang lain melanjut menjadi penyakit yang parah sampai kematian. Penelitian ini bertujuan untuk mengetahui kasus leptospirosis pada anjing di Propinsi Daerah Istimewa Yogyakarta, dan mengidentifikasi

Lymphogranuloma venereum presenting with erythema nodosum.

Science.gov (United States)

Borsje, Annemiek; van der Reijden, Wil; Soetekouw, Robin

2016-12-01

Lymphogranuloma venereum is a sexually transmitted infection caused by Chlamydia trachomatis serovar L1, L2 or L3. Anorectal infections in HIV-positive men who have sex with men comprise the majority of cases in the developed world. We present the case of a 30-year-old HIV-negative man with inguinal type lymphogranuloma venereum accompanied by erythema nodosum. © The Author(s) 2016.

Isolation and characterization of pathogenic leptospires associated with cattle

Science.gov (United States)

Pathogenic leptospires colonize the renal tubules of reservoir hosts of infection, including cattle, and are excreted via urine. In order to identify circulating serovars of pathogenic leptospires in beef cattle, and their associated rates of urinary excretion, a cross sectional study was performed....

The quest for cross protective factors of Haemophilus parasuis using 2-D gel electrophoresis

Science.gov (United States)

In swine, Haemophilus parasuis (H. parasuis) infection causes polyserositis, arthritis, and meningitis. A range of virulent to nonvirulent strains exists between and within the 15 serovars. Because of this, the pathogenicity and subsequent protection from H. parasuis disease has yet to be elucidated...

The Role of the st313-td Gene in Virulence of Salmonella Typhimurium ST313

DEFF Research Database (Denmark)

Herrero-Fresno, Ana; Wallrodt, Inke; Leekitcharoenphon, Pimlapas

2014-01-01

Multidrug-resistant Salmonella enterica serovar Typhimurium ST313 has emerged in sub-Saharan Africa causing severe infections in humans. Therefore, it has been speculated that this specific sequence type, ST313, carries factors associated with increased pathogenicity. We assessed the role in viru...

Putative outer membrane proteins of Leptospira interrogans stimulate human umbilical vein endothelial cells (HUVECS) and express during infection.

Science.gov (United States)

Gómez, Ricardo M; Vieira, Monica L; Schattner, Mirta; Malaver, Elisa; Watanabe, Monica M; Barbosa, Angela S; Abreu, Patricia A E; de Morais, Zenaide M; Cifuente, Javier O; Atzingen, Marina V; Oliveira, Tatiane R; Vasconcellos, Silvio A; Nascimento, Ana L T O

2008-01-01

Cell adhesion molecules (CAMs) are surface receptors present in eukaryotic cells that mediate cell-cell or cell-extracellular matrix interactions. Vascular endothelium stimulation in vitro that lead to the upregulation of CAMs was reported for the pathogenic spirochaetes, including rLIC10365 of Leptospira interrogans. In this study, we report the cloning of LIC10507, LIC10508, LIC10509 genes of L. interrogans using Escherichia coli as a host system. The rational for selecting these sequences is due to their location in L. interrogans serovar Copenhageni genome that has a potential involvement in pathogenesis. The genes encode for predicted lipoproteins with no assigned functions. The purified recombinant proteins were capable to promote the upregulation of intercellular adhesion molecule 1 (ICAM-1) and E-selectin on monolayers of human umbilical vein endothelial cells (HUVECS). In addition, the coding sequences are expressed in the renal tubules of animal during bacterial experimental infection. The proteins are probably located at the outer membrane of the bacteria since they are detected in detergent-phase of L. interrogans Triton X-114 extract. Altogether our data suggest a possible involvement of these proteins during bacterial infection and provide new insights into the role of this region in the pathogenesis of Leptospira.

Water-filtered infrared a irradiation in combination with visible light inhibits acute chlamydial infection.

Directory of Open Access Journals (Sweden)

Hanna Marti

Full Text Available New therapeutic strategies are needed to overcome drawbacks in treatment of infections with intracellular bacteria. Chlamydiaceae are Gram-negative bacteria implicated in acute and chronic diseases such as abortion in animals and trachoma in humans. Water-filtered infrared A (wIRA is short wavelength infrared radiation with a spectrum ranging from 780 to 1400 nm. In clinical settings, wIRA alone and in combination with visible light (VIS has proven its efficacy in acute and chronic wound healing processes. This is the first study to demonstrate that wIRA irradiation combined with VIS (wIRA/VIS diminishes recovery of infectious elementary bodies (EBs of both intra- and extracellular Chlamydia (C. in two different cell lines (Vero, HeLa regardless of the chlamydial strain (C. pecorum, C. trachomatis serovar E as shown by indirect immunofluorescence and titration by subpassage. Moreover, a single exposure to wIRA/VIS at 40 hours post infection (hpi led to a significant reduction of C. pecorum inclusion frequency in Vero cells and C. trachomatis in HeLa cells, respectively. A triple dose of irradiation (24, 36, 40 hpi during the course of C. trachomatis infection further reduced chlamydial inclusion frequency in HeLa cells without inducing the chlamydial persistence/stress response, as ascertained by electron microscopy. Irradiation of host cells (HeLa, Vero neither affected cell viability nor induced any molecular markers of cytotoxicity as investigated by Alamar blue assay and Western blot analysis. Chlamydial infection, irradiation, and the combination of both showed a similar release pattern of a subset of pro-inflammatory cytokines (MIF/GIF, Serpin E1, RANTES, IL-6, IL-8 and chemokines (IL-16, IP-10, ENA-78, MIG, MIP-1α/β from host cells. Initial investigation into the mechanism indicated possible thermal effects on Chlamydia due to irradiation. In summary, we demonstrate a non-chemical reduction of chlamydial infection using the combination

DETECTION OF Leptospira spp. AND Brucella abortus ANTIBODIES IN FREE-LIVING JAGUARS (Panthera onca IN TWO PROTECTED AREAS OF NORTHERN PANTANAL, BRAZIL

Directory of Open Access Journals (Sweden)

Selma Samiko Miyazaki ONUMA

2015-04-01

Full Text Available This study aimed to assess the exposure of free-living jaguars (Panthera onca to Leptospira spp. and Brucella abortus in two conservation units in the Pantanal of Mato Grosso, Brazil. The presence of antibodies in blood samples of eleven jaguars was investigated using autochthonous antigens isolated in Brazil added to reference antigen collection applied to diagnosis of leptospirosis by Microscopic Agglutination Test (MAT. The Rose Bengal test was applied for B. abortus antibodies. Two (18.2% jaguars were seroreactive for the Leptospira spp. antigen and the serovar considered as most infective in both animals was a Brazilian isolate of serovar Canicola (L01. All jaguars were seronegative for B. abortus. These data indicate that the inclusion of autochthonous antigens in serological studies can significantly increase the number of reactive animals, as well as modify the epidemiological profile of Leptospira spp. infection.

Antimicrobial resistance in zoonotic nontyphoidal Salmonella: an alarming trend?

Science.gov (United States)

Michael, G B; Schwarz, S

2016-12-01

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