Molecular biology techniques as a tool for detection and characterisation of Mycobacterium avium subsp. paratuberculosis

Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) is the causative agent of paratuberculosis, also known as Johne’s disease, a chronic intestinal infection in cattle and other ruminants. Paratuberculosis is characterised by diarrhea and weight loss that occurs after a period of a few months up to several years without any clinical signs. The considerable economic losses to dairy and beef cattle producers are caused by reduced milk production and poor reproduction performance in subclinically infected animals. Early diagnosis of infected cattle is essential to prevent the spread of the disease. Efforts have been made to eradicate paratuberculosis by using a detection and cull strategy, but eradication is hampered by the lack of suitable and sensitive diagnostic methods. This thesis, based on five scientific investigations, describes the development of different DNA amplification strategies for detection and characterisation of M. paratuberculosis. Various ways to pre-treat bacterial cultures, tissue specimens and fecal samples prior to PCR analysis were investigated. Internal positive PCR control molecules were developed and used in PCR analyses to improve the reliability and to facilitate the interpretation of the results. The sensitivity of the ultimate methods was found to be approximate that of culture and allowed detection of low numbers of M. paratuberculosis expected to be found in subclinically infected animals. Genomic DNA of a Swedish mycobacterial isolate, incorrectly identified by PCR as M. paratuberculosis was characterised. The isolate was closely related to M. cookii and harboured one copy of a DNA segment with 94% similarity to IS900, the target sequence used in diagnostic PCR for detection of M. paratuberculosis. This finding highlighted the urgency of developing or evaluating PCR systems based on genes other than IS900. A PCR-based fingerprinting method using primers targeting the enterobacterial intergenic consensus sequence (ERIC) and the IS900 sequence was developed and successfully used to distinguish M. paratuberculosis from closely related mycobacteria, including the above mentioned mycobacterial isolate. In conclusion, the molecular biology techniques developed in these studies have proved useful for accelerating the diagnostic detection and characterisation of M. paratuberculosis

The occurrence of Chlamydia spp. in pigs with and without clinical disease

<p>Abstract</p> <p>Background</p> <p>Within the genera <it>Chlamydia</it>, the development of refined diagnostic techniques has allowed the identification of four species that are capable of infecting pigs. The epidemiology, clinical, and zoonotic impacts of these species are however largely unknown. The study aimed to investigate the presence of <it>Chlamydia </it>spp. in the intestines of growing pigs and in conjunctival swabs from finisher pigs, and relate the findings to clinical signs.</p> <p>Results</p> <p>By histology, 20 of 48 pigs had intestinal lesions that may be consistent with chlamydial infection. By PCR, forty-six of the pigs were positive whereas two samples were inhibited. Sequencing of 19 DNA extracts identified these as <it>Chlamydia suis</it>. By immunohistochemistry, 32 of 44 samples were positive and a significant relationship was detected between macroscopically visible intestinal lesions and a high degree of infection. By real-time PCR, a significant difference was detected between pigs with and without conjunctivitis when a Ct value of 36 was employed but not when a Ct value of 38 was employed.</p> <p>Conclusions</p> <p><it>Chlamydia suis </it>was demonstrated in most samples and overall, no correlation to clinical signs was detected. However, a correlation was noted between samples with a high degree of infection and the presence of clinical signs. It is possible, that the intensive pig production systems studied might predispose for the transmission and maintenance of the infection thus increasing the infectious load and the risk for disease in the pig.</p

Establishing Streptomycin Epidemiological Cut-Off Values for Salmonella and Escherichia coli

This study was conducted to elucidate the accuracy of the current streptomycin epidemiological cut-off value (ECOFF) for Escherichia coli and Salmonella spp. A total of 236 Salmonella enterica and 208 E. coli isolates exhibiting MICs between 4 and 32¿mg/L were selected from 12 countries. Isolates were investigated by polymerase chain reaction for aadA, strA, and strB streptomycin resistance genes. Out of 236 Salmonella isolates, 32 (13.5%) yielded amplicons for aadA (n¿=¿23), strA (n¿=¿9), and strB (n¿=¿11). None of the 60 Salmonella isolates exhibiting MIC 4¿mg/L harbored resistance genes. Of the Salmonella isolates exhibiting MICs 8¿mg/L, 16¿mg/L, and 32¿mg/L, 1.6%, 15%, and 39%, respectively, tested positive for one or more genes. For most monitoring programs, the streptomycin ECOFF for Salmonella is wild type (WT) =32 or =16¿mg/L. A cut-off value of WT =32¿mg/L would have misclassified 13.5% of the strains as belonging to the WT population, since this proportion of strains harbored resistance genes and exhibited MICs =32¿mg/L. Out of 208 E. coli strains, 80 (38.5%) tested positive for aadA (n¿=¿69), strA (n¿=¿18), and strB (n¿=¿31). Of the E. coli isolates exhibiting MICs of 4¿mg/L, 8¿mg/L, 16¿mg/L, and 32¿mg/L, 3.6%, 17.6%, 53%, and 82.3%, respectively, harbored any of the three genes. Based on the European Committee on Antimicrobial Susceptibility Testing guidelines (ECOFF =16¿mg/L), 25% of the E. coli strains presenting MIC =16¿mg/L would have been incorrectly categorized as belonging to the WT population. The authors recommend an ECOFF value of WT =16¿mg/L for Salmonella and WT =8¿mg/L for E. coli

Anthrax outbreak in a Swedish beef cattle herd - 1st case in 27 years: Case report

After 27 years with no detected cases, an outbreak of anthrax occurred in a beef cattle herd in the south of Sweden. The outbreak was unusual as it occurred in winter, in animals not exposed to meat-and-bone meal, in a non-endemic country

Investigation of Chlamydophila spp. in dairy cows with reproductive disorders

<p>Abstract</p> <p>Background</p> <p>Reports worldwide indicate high prevalence of <it>Chlamydophila </it>spp. infection in cattle. To assess the prevalence in Sweden, 525 cows in 70 dairy herds with reproductive disorders was investigated.</p> <p>Methods</p> <p>To detect antibodies two commercially available kits were used. Moreover, 107 specimens, including vaginal swabs, organ tissues and milk were analysed by Polymerase Chain Reaction (PCR).</p> <p>Results</p> <p>Two (0.4%) cows were seropositive in the Pourquier <it>Cp. abortus </it>ELISA. The seroprevalence with the Chekit ELISA was 28% with no difference between cases and controls. Five specimens were positive in real-time PCR and further analysed by nested PCR. <it>Cp. pecorum </it>was confirmed by partial <it>omp1 </it>DNA sequencing of the nested PCR product of vaginal swabs from control cows.</p> <p>Conclusion</p> <p>The results suggest that <it>Cp. abortus </it>infection is absent or rare in Swedish cows whereas <it>Cp. pecorum </it>is probably more spread. They also suggest that <it>Chlamydophila </it>spp. are not related to reproduction disorders in Swedish cattle.</p

"Förskolans rytmik - varje stund är unik" : En kvalitativ studie om hur förskollärare och barn ser på rytmikutövande i förskolan

Denna studie syftar till att undersöka de äldre barnens möjligheter till rytmikutövande i förskolan. Studien syftar även till att undersöka eventuella skillnader i förskollärares och barns syn på rytmikutövande. Studiens syfte är angeläget då det enligt min uppfattning finns en avsaknad av planerade musikaktiviteter i förskolan samtidigt som förskollärarna är skyldiga att arbeta i enighet med läroplanens mål och riktlinjer. Materialet samlades in genom kvalitativa intervjuer med förskollärare samt fokusgruppsamtal med barn där materialet analyserades utifrån tematisk analys och bearbetades med utgångspunkt i ett ramfaktorteoretiskt perspektiv. Utifrån studiens resultat framgick det att ramfaktorer som tid, materialresurser, barngruppens storlek samt förskolans styrdokument, påverkar förskollärarna i deras utformning av musikundervisningen. Ramfaktorerna påverkar även barnens inställning och möjligheter till rytmikutövande i förskolan. Studiens resultat visar även att förskollärarnas syn på sin musikaliska kompetens påverkar deras förmåga att kunna omsätta hinder till möjligheter vid utformning av rytmikaktiviteter i förskolan. Studiens resultat visar utmärkande skillnader i förskollärarnas och barnens syn på musik och rytmik. Detta genom att förskollärarnas beskrivningar är starkt kopplade till deras eget intresse, förmåga samt erfarenhet, medan barnen ger olika förslag på instrument som inte alltid är kopplade till deras eget musicerande. Resultatet visar även skillnader i förskollärare och barns syn på hinder vid rytmikutövande, där vissa förskollärare uttrycker en viss tveksamhet kring sin musikaliska förmåga som de beskriver som ett hinder för deras rytmikutövande i förskolan. Detta skiljer sig i förhållande till barnens uppfattningar då barnen inte lyfter sin musikaliska förmåga som ett hinder för rytmikutövande utan deras syn på hinder vid rytmikutövande grundas i deras uppfattningar kring ljudnivån i förskolans lokaler samt antal barn som deltar i musikaktiviteterna

Pragmatic Ability in Children with Cochlear Implants

A cochlear implant (CI) is a hearing device that makes it possible for individuals who are deaf or has a severe hearing impairment to receive auditory information and develop spoken language. The pragmatic ability may be affected. In short, pragmatics may be described as the study of language use in social contexts. Pragmatic ability can be seen as the result of the individual‟s behavior as well as the underlying causes. The aim of the present study was to describe the pragmatic ability in children with CI. An approach inspired by Conversation Analysis (CA) was used in order to highlight the various phenomena that occurred in the interaction. Seven children with CI participated in the study, five girls and two boys. Each conversation consisted of either a child with CI interacting with a peer, or a child with CI interacting with a parent or a teacher. A total of 14 conversations were analyzed and phenomena relevant to the study were examined. To gather further information regarding the children‟s communicative behavior, Children’s Communication Checklist was filled in by parents and teachers. The children who participated in the study constitute a heterogeneous group and there was no clear pattern when it comes to hearing-impairment and pragmatic ability. The result showed that children with CI used both specific and non-specific requests for clarification. It seems as if intelligibility on the sentence level may reflect how efficient the interaction turns out, as the children with high intelligibility were the ones who managed to solve misunderstandings the best in the conversations. Furthermore, the result demonstrated that the adult participants used a higher rate of specific requests for clarification in contrast to children with CI.Ett cochleaimplantat (CI) är ett hjälpmedel som gör att personer med grav hörselnedsättning eller personer som är döva får möjlighet att höra och utveckla talat språk. Den pragmatiska förmågan kan vara påverkad. Pragmatik kan i stort betecknas som studiet av språkanvändning i interaktion och pragmatisk förmåga kan beskrivas som ett resultat av individens beteende samt bakomliggande orsaker. Syftet med föreliggande studie var att beskriva pragmatisk förmåga hos barn med CI. Ett arbetssätt inspirerat av Conversation Analysis (CA) har använts för att belysa fenomen som förekom i interaktionen. I studien deltog sju barn med CI, varav fem flickor och två pojkar. Deltagarna videofilmades när de interagerade med en jämnårig kamrat, respektive en person ur förskolepersonalen eller en förälder. Totalt 14 samtal analyserades och för studien relevanta fenomen belystes. För att inhämta kompletterande information kring barnens samspelsförmåga fylldes Children’s Communication Checklist i av föräldrar och personal. Barnen som deltog i studien är en heterogen grupp. Vidare ses inga entydiga mönster vad gäller hörselnedsättning och pragmatiska förmågor. I studien visades att barn med CI använder sig av både generella och specifika begäran om förtydligande. Förståelighet på meningsnivå tycks avspegla hur effektivt samspelet fortskrider då de barn som har hög förståelighet är de som har färre begäranden om förtydligande i samtal. Vidare visar resultaten att de vuxna samtalsdeltagarna använder fler andel specifika begäran om förtydligande i jämförelse med barn med CI

To live in anuncontrolled body : A literature study in adolescents with type 1 diabetes and eating disorders

Forskning visar att ungdomar med typ 1 diabetes (T1D) har dubbelt så stor risk att drabbas av en ätstörning jämfört med ungdomar utan T1D. Dessutom ökar även mortalitet och morbiditet avsevärt hos ungdomarna med denna kombination. Syftet med litteraturstudien var att beskriva vad ungdomars upplevelser är i samband med ätstörningar och T1D. Dataanalysen genomfördes med inspiration från metoden innehållsanalys. Litteraturstudiens resultat visar kunskap från sju vetenskapliga artiklar. Efter tolkningen av resultaten i de vetenskapliga artiklarna formulerades fem teman: Social dimension, Fysisk dimension, Emotionell dimension, Triggerfaktorer och Coping. Resultatet gestaltade att stöd från familj och vänner upplevdes underlättande för ungdomarna, men även som ett ofullständigt stöd. Stödet från sjukvårdspersonalen upplevdes betydelsefullt. En del av ungdomarna upplevde negativa kroppsbilder, vilket föranledde till underdosering av insulin. Ätstörningarna kunde förorsaka depressiva känslor och samtidigt upplevd kroppskontroll. Stressade livssituationer kunde trigga igång ätstörningen. Upplevda copingstrategier som gav stöd i återhämtningen från ätstörningen var att dela sina erfarenheter med ungdomar i samma situation. Litteraturstudien visar att sjuksköterskan kan vara stödjande för ungdomar med T1D och ätstörningar genom att visa ett förhållningssätt i former av att vara lyssnande, icke dömande och visa tilltro. Litteraturstudien visar behov av ytterligare forskning för ett mer evidensbaserat kliniskt vårdande.Research shows that adolescents with T1D runs a double risk of eating disorders compared to adolescents without T1D. Additionally, morbidity and mortality increases considerably at the combination. The aim of this literature study was to describe adolescents' experiences of living with T1D and eating disorders. The results in this literature study shows knowledge from seven scientific articles. Data analysis was inspired by content analysis. The results in this literature study shows knowledge from seven scientific articles. The interpretation resulted in five formulated themes: Social dimension, Physical dimension, Emotional dimension, Triggers and Coping. Results indicate that support originating from family, friends and healthcare professionals was experienced as facilitating, but also as an uncomplete support. Some adolescents experienced negative body images, which conduced to insulin omission. The eating disorders provided depressive feelings and simultaneously experienced body control. Stressed life situations could trigger eating disorders. Coping strategies which aided the recovery of eating disorders was sharing experiences with peers. This literature study indicate that nurses can be supportive for adolescents with T1D and eating disorders through approaching in forms of being listening, non-judging and trustful. This literature study display requirements of supplementary research for a more evidence based clinical caring