Factors affecting the pressure resistance of some Campylobacter species

Aims: To compare pressure resistance between strains of Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter fetus, and to investigate the effect of suspending medium on pressure resistance of sensitive and more resistant strains. Methods and Results: Six strains of C. jejuni and four each of C. coli, C. lari and C. fetus were pressure treated for 10 min at 200 and 300 MPa. Individual strains varied widely in pressure resistance but there were no significant differences between the species C. jejuni, C. coli and C. lari. Campylobacter fetus was significantly more pressure sensitive than the other three species. The pressure resistance of C. jejuni cultures reached a maximum at 16-18 h on entry into stationary phase then declined to a minimum at 75 h before increasing once more. Milk was more baroprotective than water, broth or chicken slurry but did not prevent inactivation even of a resistant strain at 400 MPa. Conclusions: Pressure resistance varies considerably between species of Campylobacter and among strains within a species, and survival after a pressure challenge will be markedly influenced by culture age and food matrix. Significance and Impact of the Study: Despite the strain variation in pressure resistance and protective effects of food, Campylobacter sp. do not present a particular problem for pressure processing.

Campylobacter insulaenigrae sp nov., isolated from marine mammals

Phenotypic and phylogenetic studies were performed on four Campylobacter-like organisms recovered from three seals and a porpoise. Comparative 16S rRNA gene sequencing studies demonstrated that the organisms represent a hitherto unknown subline within the genus Campylobacter, associated with a subcluster containing Campylobacter jejuni, Campylobacter coli and Campylobacter lari. DNA-DNA hybridization studies confirmed that the bacteria belonged to a single species, for which the name Campylobacter insulaenigrae sp. nov. is proposed. The type strain of Campylobacter insulaenigrae sp. nov. is NCTC 12927(T) (= CCUG 48653(T)).

Rodents as carriers of disease: preliminary studies in the United Kingdom

The University of Reading has conducted some preliminary work on the prevalence of Campylobacter spp., Salmonella spp. and Arenavirus in Norway rats trapped from farms and semi-urban areas in central southern England. Campylobacter is the cause of a notificable disease in the UK, with 57,772 cases reported for England and Wales in 2009. Transmission to humans is believed to be primarily through undercooked meat, from contaminated water, and through contact with pets; and symptoms include a high temperature, severe diarrhoea, vomiting and abdominal pain. Ninety-seven per-cent of sporadic cases have been attributed to farm animals, and in particular the meat and poultry industry. There are eighteen species of Campylobacter, eleven of which can be pathogenic to humans; although the principal species that cause gastrointestinal disease in humans are C. jejuni and C. coli; although C. lari, C. helveticus and C. upsaliensis are also involved. Salmonella species also causes a gastrointestinal disease, and in the UK, is common in chicken and has been linked to egg production. Species are typed using antigen specific agglutination tests, or by their susceptibility to specific bacteriophage. Some strains are known to be linked with human disease (eg. S. enteritidis PT4).

The role of rodents as carriers of disease on UK farms: a preliminary investigation

In the UK, Campylobacter spp. and Lymphocytic Choriomeningitis Virus (LCMV), an Old World arenavirus, cause two zoonoses of concern that may be transmissible from rodents to humans and livestock. The aims of this preliminary investigation were to examine the occurrence of Campylobacter spp. and LCMV in Norway rats Rattus norvegicus on UK farms and to identify and characterise the Sequence Types of the Campylobacter isolates. Samples were collected from wild Norway rats and fresh Norway rat faeces. Multi Locus Sequence Typing (MLST) was performed on C. spp. isolates and samples were tested for arenavirus RNA by RT-PCR. Six C. spp. isolates were identified. One isolate was C. lari and five isolates were C. jejuni. Following MSLT profiling, three unique C. jejuni sequence types were identified. Two of which are novel and the third is typically associated with livestock and human infection. Nine positive results for LCMV were obtained giving an overall prevalence of 25% across four sites. This is higher than previously reported for this species.

Speak Good English Movement in Singapore : Reactions in Social and Traditional Media

The first Speak Good English Movement, SGEM, took place in 2000, and has been organized annually ever since. Speaking a “standard” form of English is considered to bring increased personal power. However, the SGEM wants the Singaporeans to use “standard” English in their private life as well. A decade after the beginning of the campaign, a Speak Good Singlish Movement was started. Based on studies of language and identity, it is understandable why some Singaporeans might feel the SGEM threatens their identity. However, the reactions towards the campaign are mainly positive. For the purposes of this analysis, Twitter messages, Facebook pages, and newspaper articles from The Straits Times were collected. The SGEM has hailed both direct and indirect praise and criticism in both social and traditional media: Five newspaper articles praise the campaign while five criticize it; the results are nine and seven respectively for social media. This thesis looks at reactions towards the SGEM in both social and traditional media, analyzes how these reactions might relate to the ideas of the power of language, its variety and the relation of language and identity.

Collider aspects of flavor physics at high Q

This chapter of the "Flavor in the era of LHC" workshop report discusses flavor-related issues in the production and decays of heavy states at the LHC at high momentum transfer Q, both from the experimental and the theoretical perspective. We review top quark physics, and discuss the flavor aspects of several extensions of the standard model, such as supersymmetry, little Higgs models or models with extra dimensions. This includes discovery aspects, as well as the measurement of several properties of these heavy states. We also present publicly available computational tools related to this topic.

Freqüência de isolamento de Campylobacter em gatos com e sem diarréia e sensibilidade a antimicrobianos das estirpes isoladas

Pós-graduação em Medicina Veterinária - FMVZ

Campylobacter sp como perigo biológico na produção de peito de frango maturado

Pós-graduação em Microbiologia Agropecuária - FCAV

Partizioni di un intero

Questa tesi di laurea tratta delle partizioni di un intero positivo. La tesi viene suddivisa in tre capitoli: nel primo capitolo definirò cosa significa scomporre additivamente un intero positivo e come si può rappresentare una partizione cioè utilizzando diagrammi, chiamati \textit{diagrammi di Ferrers}, o tabelle, chiamate \textit{tableau di Young}, si possono rappresentare graficamente partizioni. In seguito, in questo capitolo, verrà definita la funzione di partizione e, infine, tratterò delle partizioni ordinate. Il secondo capitolo ha carattere storico: infatti, mostra come cinque famosi matematici, Eulero, Ramanujan e Hardy, Hans Rademacher e Ken Ono, nel tempo abbiano affrontato il problema di trovare una formula matematica che meglio rappresenti la funzione di partizione. Il terzo ed ultimo capitolo riguarda le applicazioni delle partizioni, cioè come esse abbiano una relazione con le classi di coniugio nel gruppo simmetrico $S_{n}$ e con le classificazioni dei gruppi abeliani di ordine $p^{n}$, con p un numero primo. Di alcune affermazioni ( o teoremi ) nei capitoli seguenti non è stata riportata la dimostrazione; in questi casi si rimanda direttamente alle corrispondenti citazioni bibliografiche. 

Duplication and functional divergence in the chalcone synthase gene family of Asteraceae: evolution with substrate change and catalytic simplification.

Plant-specific polyketide synthase genes constitute a gene superfamily, including universal chalcone synthase [CHS; malonyl-CoA:4-coumaroyl-CoA malonyltransferase (cyclizing) (EC 2.3.1.74)] genes, sporadically distributed stilbene synthase (SS) genes, and atypical, as-yet-uncharacterized CHS-like genes. We have recently isolated from Gerbera hybrida (Asteraceae) an unusual CHS-like gene, GCHS2, which codes for an enzyme with structural and enzymatic properties as well as ontogenetic distribution distinct from both CHS and SS. Here, we show that the GCHS2-like function is encoded in the Gerbera genome by a family of at least three transcriptionally active genes. Conservation within the GCHS2 family was exploited with selective PCR to study the occurrence of GCHS2-like genes in other Asteraceae. Parsimony analysis of the amplified sequences together with CHS-like genes isolated from other taxa of angiosperm subclass Asteridae suggests that GCHS2 has evolved from CHS via a gene duplication event that occurred before the diversification of the Asteraceae. Enzyme activity analysis of proteins produced in vitro indicates that the GCHS2 reaction is a non-SS variant of the CHS reaction, with both different substrate specificity (to benzoyl-CoA) and a truncated catalytic profile. Together with the recent results of Durbin et al. [Durbin, M. L., Learn, G. H., Jr., Huttley, G. A. & Clegg, M. T. (1995) Proc. Natl. Acad. Sci. USA 92, 3338-3342], our study confirms a gene duplication-based model that explains how various related functions have arisen from CHS during plant evolution.