Propionibacterium sp. is commonly isolated in association with orthopedic implants, either as a pathogen or a colonizer. Microbial characteristics that indicate whether the isolated species is a likely cause of orthopedic implant infection versus a colonizing agent would be clinically useful. We performed a prospective trial to determine the species of Propionibacterium and the phylotype (IA, IB, II, III) of Propionibacterium acnes isolated from the surface of removed orthopedic implants, and we correlated these findings with the presence or absence of infection. P. acnes represented 61 of 62 isolates. P. acnes type I was more commonly isolated than was type II (62% versus 38%, respectively), whether associated with infection or not. P. acnes type III was not detected. There was no clear association between types I and II P. acnes and infection or colonization of failed orthopedic implants (P = 0.75), however type IB strains were more frequently isolated than type IA from infected prosthese.

In recent years the weed commonly known as dodder has become an important reason for the rejection of several alfalfa seed fields for certification in Utah. The rapid spread of infestation in alfalfa seed fields, difficulty in removing the dodder seed from the alfalfa seed due to the similarity in size, and a lack of adequate control are among the main causes for the rising concern with dodder, Dodder is an annual which reproduces from seed each year.

A single tube detection kit was designed as a rapid, easy-to use and reliable test to detect Listeria spp.. Various food samples (vegetables and raw catfish fillets) were used in order to validate the performance of the detection kit. L. grayi was detected in one ready-to-eat (RTE) vegetables with the detection kit while no Listeria spp. was detected using the modified FDA-BAM method. In addition, both the detection kit and modified FDA-BAM method indicated that twelve catfish fillets were Listeria positive. The detection kit had 100% sensitivity and specificity in less detection time (24 h) than the modified FDA-BAM method (60% specificity, >72 h). There was no difference (P<0.05) between the kit and the modified FDA-BAM method on MPN for Listeria spp.

Malaria is the main cause of approximately one million deaths every year that mostly affect children in south of Sub-Saharan Africa. The Anopheles gambiae complex consists of seven morphologically indistinguishable sibling species. However, their behavior, ecological adaptations, vectorial capacity, and geographical distribution differ. Studying the phylogenetic relationships among the members of the complex is crucial to understanding the genomic changes that underlie evolving traits. These evolutionary changes can be related to the gain or loss of human blood choice or to other epidemiologically important traits. In order to understand the phylogenetic relationships and evolutionary history of the members of the An. gambiae complex, breakpoints of the 2Ro and 2Rp inversions in An. merus and their homologous sequence in the outgroup species were analyzed using fluorescent in situ hybridization (FISH), library screening, whole-genome mate-paired sequencing and bioinformatics analysis. Molecular phylogenies of breakpoint genes were constructed afterwards. In addition, multigene phylogenetic analyses of African malaria vectors were performed. Our findings revised the chromosomal phylogeny, and demonstrated the ancestry of 2Ro, 2R+p and 2La arrangements.  Our new chromosomal phylogeny strongly suggests that vectorial capacity evolved repeatedly in members of the An. gambiae complex, and the most important vector of malaria in the world, An. gambiae, is more closely related to ancestral species than was previously thought. Our molecular phylogeny data were in agreement with chromosomal phylogeny, indicating that the position of the genetic markers with respect to chromosomal inversion is important for interpretation of the  phylogenetic trees. Multigene phylogenetic analysis revealed that a malaria mosquito from humid savannah and degraded rainforest areas, An. nili, belongs to the basal clade and is more distantly related to other major African malaria vectors than was assumed previously. Finally, for the first time a physical map of 12 microsatellite markers for the Asian malaria vector An. stephensi was developed. Knowledge about the chromosomal position of microsatellites was shown to be important for a proper estimation of population genetic parameters. In conclusion, our study improved understanding of genetics and evolution of some of the major malaria vectors in Africa and Asia. / Ph. D.

Three studies were conducted to assess if the ability of Enterococcus spp. surviving the ensiling process and bovine gastrointestinal tract could impact risk of bovine mastitis. The first study determined ability of enterococci to survive 3 wk ensiling. Grass and corn crops were divided into 3 treatments: 2 commercial silage inoculants, 1 negative control. After wk 1, 2, and 3 of ensiling, dry matter and bacterial enumeration were performed. Addition of silage inoculant led to greater levels of enterococci in grass silage compared with negative control levels, but showed less difference in inoculated corn silage. The second study quantified enterococci shedding rates in lactating dairy cows. Using a 4 x 4 Latin Square design, lactating, ruminally fistulated Holsteins were inoculated with enterococcal isolates from silage inoculants, ensiled forages, or clinical mastitis cases. Over the 4-period study, each period consisted of rumen and fecal sampling (2 wk) followed by a wash period (10 d). There were no significant differences in rumen or fecal enterococci levels between the 4 treatments. Both rumen and fecal enterococci levels showed significant differences between baseline and treatment periods (period 3, 4). The third study analyzed similarity in enterococcal isolates of silage and bovine origin using pulsed-field gel electrophoresis patterns from SmaI restrictions. Dendogram analysis showed none of the isolates met or were greater than a 75% genetic similarity and produced a genetically diverse population. Results suggest Enterococcus spp. from silage inoculants are not likely to contribute to an increased risk of enterococcal bovine mastitis. / Master of Science

Contexte: Les infections gastro-intestinales constituent un important problème de santé publique. Si plusieurs études recensent l'épidémiologie des cas sporadiques, peu se penchent sur la répétition d'infections dans certains ménages. L'objectif de cette étude est de déterminer quels sont les facteurs de risque associés à une récidive à Campylobacter ou à Salmonella déclarés de 2001 à 2007 dans les ménages en Montérégie. Méthodologie: Deux études ont été réalisées. Une étude descriptive a été conduite afin de dresser un portrait des deux groupes à l'étude soit : ménages avec répétitions d'infections à Campylobacter ou à Salmonella et ménages sans répétition d'infection (avec cas sporadique seulement). L'ensemble des sujets de cette étude ont été sélectionnés à partir du registre MADO. Une étude cas-témoins a ensuite permis de comparer les facteurs de risque pour chaque groupe de ménages. Un questionnaire administré au téléphone permettait de recueillir les habitudes des ménages-cas et des ménages-témoins. Les analyses ont été effectuées par régression logistique conditionnelle adaptée pour un appariement 1 cas : 2 témoins. Résultats: L'analyse descriptive portait sur 4181 cas d'infections à Campylobacter et Salmonella , déclarés du ler janvier 2001 au 31 décembre 2007. Le pourcentage de cas partageant la même adresse a été estimé à 7,8% pour Campylobacter et 7,6% pour Salmonella . Les cas de récidive présentent les mêmes caractéristiques que les cas sporadiques en ce qui concerne l'agent le plus en cause, la saison de survenue, l'âge du cas et le milieu d'habitation. Les habitudes des cas provenant de 80 ménages avec récidive et 160 ménages sans récidive ont été comparées. Dans un modèle final, en tenant compte seulement des variables affectant le ménage, il apparaît que l'habitation dans un milieu rural (RC = 2,89 ; IC95% = 1,53 - 5,46), la présence d'enfants de moins de 5 ans (RC = 2,63 ; IC95% = 1,29 - 5,37), l'exposition à une source hydrique contaminée (RC = 2,6 ; IC95% = 1,18 - 5,93) et le travail en contact avec des animaux (RC = 2.39 ; IC95% = 1,06 - 5,36) soient associés à un risque de récidive dans le ménage. Conclusion: Cette étude révèle que les répétitions de cas à certaines adresses peuvent s'expliquer par des caractéristiques du ménage. Des habitudes de vie spécifiques dans les ménages avec récidives par rapport aux ménages avec cas sporadiques ont été identifiées.

Multiresistenta bakterier så som meticillinresistenta Staphylococcus aureus (MRSA), bakterier som producerar extended-spectrum beta-lactamase (ESBL) och vancomycinresistenta enterokocker (VRE) är ett problem sedan årtionden tillbaka och som ökar för varje år. Idag på mikrobiologen, Unilabs Skövde, isoleras bakteriestammar från selektiva medier för just MRSA, ESBL och VRE på blodagar innan resistensbestämningarna utförs. Syftet med studien var därför att undersöka möjligheten att göra diskdiffusionstest direkt från de selektiva medierna och således kunna svara ut resultaten tidigare. Utvärdering av detta gjordes genom att undersöka om storleken på antibiotikazonerna för sammanlagt 64 isolat påverkades av att bakterierna som användes vuxit på ett selektivt agarmedium i förhållande till om de vuxit på blodagar. Resultatet visade vad som ansågs vara en normal variation på maximalt ±2 mm för alla parvisa zoner utom en på 3 mm. Av alla zoner som undersöktes för MRSA, ESBL och VRE var majoriteten identiska i antal millimeter, 62 %, 89 % och 98 % respektive. Baserat på det goda resultatet ansågs materialet vara tillräckligt stort för att göra bedömningen att metoden är utförbar. Med tanke på de positiva effekterna av att göra resistensbestämningar direkt från de selektiva agarmedierna görs rekommendationen till mikrobiologen, Unilabs Skövde, att övergå till denna metod. / Multiresistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase (ESBL) producing bacteria and vancomycin-resistant enterococci (VRE) have been a problem for decades with an increasing rate. Today, at mikrobiologen, Unilabs Skövde, bacterial strains are isolated from selective media for MRSA, ESBL and VRE onto blood agar before the susceptibility testing. The aim of the study was to examine the possibility of disk diffusion susceptibility testing directly from the selective media and thus be able to reply the findings earlier. The zones of inhibition were examined for a total of 64 isolates after disk diffusion testing from both the selective and blood agar plates in order to evaluate if the zone sizes were affected. The results showed what was considered a normal variation of ±2 mm for all pairwise zones except for a difference in 3 mm. The majority of all zones tested for MRSA, ESBL and VRE had equally large zones, 62%, 89% and 98% respectively. Based on the good results, the material was considered enough to make the conclusion that the method is feasible. Considering the positive effects of making susceptibility testing directly from selective agar, a change to this method is recommended to mikrobiologen, Unilabs Skövde.

Los patrones de diversidad de murciélagos a lo largo de una gradiente de elevación en las Yungas están poco documentados. Por ello, se realizó una evaluación en la cuenca del río Pampa Hermosa entre los 986 y 2900 m en Satipo, Junín, con la finalidad de determinar si el patrón de riqueza de especies en las Yungas de Junín es monotónico como en otras gradientes. Para ello se muestrearon siete localidades (F1-F7) empleando un total de 395 redes de niebla durante la época seca del 2011. Se registraron un total de 22 especies de murciélagos que corresponden a las familias Phyllostomidae (21 especies) y Vespertilionidae (una especie). Los puntos de mayor y menor riqueza fueron F3 (1533-1569 m) con 13 especies y F7 (2850-2900 m) con tres especies respectivamente. Las especies más abundantes en Pampa Hermosa fueron Carollia perspicillata (1.566 x 10-3 individuos/m.h), C. brevicauda (1.351 x 10-3 individuos/m.h) y Sturnira erythromos (1.443 x 10-3 individuos/m.h). El perfil altitudinal fue consistente con la regla de Rapoport debido a que se registró el aumento de la amplitud del rango de elevación de las especies a medida que se ascendía en la gradiente altitudinal. El análisis de gradiente demostró que no existe una correlación inversa significativa entre la abundancia relativa y la altitud (r=-0.653, p=0.112), mientras que la riqueza de especies total presentó una relación negativa significativa tanto lineal (r2=0.664, p=0.026) como polinomial (r2=0.886, p=0.013) y una correlación inversa significativa (r=-0.815, p=0.026) con la altitud. Este patrón sería consecuencia de las actividades agropecuarias y la expansión urbana que han homogenizado los hábitats en Pampa Hermosa, las cuales tendrían un mayor impacto en los pisos bajos debido a su mayor cercanía a centros poblados (e.g. Satipo), lo cual afectaría el patrón riqueza-altitud.

La presente investigación se realizó con el fin de evaluar el efecto probiótico de 3 diferentes dosis de Lactobacillus spp. como aditivo sobre parámetros productivos en Cavia porcellus. Se utilizaron 4 grupos de 8 cuyes machos destetados a las 2 semanas cada uno: 3 tratamientos y 1 control. El primer (T1), segundo (T2) y tercer tratamiento (T3) constaron de dosis diarias de 2.5x108, 2.5x109 y 2.5x1010 ufc del probiótico, respectivamente; para el grupo control (TC) suero fisiológico. El probiótico se obtuvo de un yogurt comercial mediante técnicas de aislamiento, identificación y liofilización. La administración del probiótico y el suero fisiológico fue vía oral e individualmente por 7 semanas; además, de recibir concentrado y forraje como alimento. Se empleó un diseño por bloques completos y aleatorizado, las variables en estudio fueron: peso, incremento de peso, conversión alimenticia y rendimiento de carcasa. Los resultados a las 7 semanas fueron: peso final de T1, T2, T3 y TC, 921, 933, 947 y 913 gr; incremento de peso total de T1, T2, T3 y TC, 640.5, 644.75, 632 y 654.75 gr; índice de conversión alimenticia promedio de T1, T2, T3 y TC, 2.90, 2.83, 3.11 y 2.52; y el rendimiento de carcasa promedio de T1, T2, T3 y TC 73.6%, 72.3%, 71.9% y 72.2%, respectivamente. Al análisis estadístico se encontró que no existe diferencia estadísticas significativas entre los grupos tratamiento y control, en las variables estudiadas. A la necropsia no se encontraron lesiones macroscópicas y los grupos tratamiento dieron resultados negativos de cultivos bacterianos para Salmonella spp. en un 100% de los casos, mientras que el grupo control dio un resultado positivo, lo que demuestra que el probiótico posiblemente puede inhibir el crecimiento de Salmonella.The present investigation was realized in order to evaluate the probiotic effect of 3 different doses of Lactobacillus spp. as additive on productive parameters in Cavia porcellus. There were 4 groups of 8 male guinea pigs weaned at 2 weeks each one: 3 treatments and 1 control. The first (T1), the second (T2) and the third (T3) consist of a daily doses of 2.5x108, 2.5x109 y 2.5x1010 cfu of the probiotic respectively; for the control group (TC) only physiological serum. The probiotic was obtained from a commercial yogurt by isolation, identification and freeze-dry techniques. The administration of the probiotic and the serum was individually and orally for 7 weeks, besides receiving concentrate and forage as food. Was used a complete and randomized blocks design, the variables in study were: weight, gain of weight, food conversion and carcass performance. The results at the 7 weeks were: final weight of T1, T2, T3 and TC, 921, 933, 947 and 913 gr; gain of total weight of T1, T2, T3, TC, 640.5, 644.75, 632 and 654.75 gr; average food conversion index of T1, T2, T3 and TC, 2.90, 2.83, 3.11 and 2.52; and average of carcass performance of T1, T2, T3 and TC, 73.6%, 72.3%, 71.9% and 72.2%, respectively. At the statistical analysis were found that there isn’t significant statistic difference between the treatments and control groups in the study variables. At the necropsy there wasn’t macroscopic injuries and the treatments groups show negative results in specific bacterial cultures for Salmonella spp. in 100% of the cases, while the control group have one positive result, which demonstrate that the probiotic can possibly disable Salmonella's growth.

A dermatite digital (DD) é uma das principais doenças podais que acomete bovinos leiteiros, destacando-se negativamente pela queda na produção o volume de leite produzido e pelo seu oneroso tratamento. Como alternativa ao uso de antibióticos, a terapia fotodinâmica (PDT) se apresenta como uma opção interessante no tratamento de infecções cutâneas em animais de produção, evitando a seleção de micro-organimos resistentes. O objetivo deste estudo foi investigar o uso da PDT para tratar a DD em bovinos leiteiros. Para compor os grupos experimentais, 20 lesões de DD, localizadas nos membros pélvicos de 16 animais, foram tratadas com PDT (350mW/Led; = 660nm &#177; 10nm; A = 13,20 cm2; I = 120mW/cm2) associado à aplicação tópica do fotossenbilizador azul de metileno (300&micro;M; apresentação em gel; com 5 min de tempo de pré-irradiação) ou com aplicação tópica de oxitetraciclina (500 mg em solução à 20%). Cada lesão foi tratada duas vezes com intervalo de 14 dias entre elas. A caracterização macroscópica das lesões foi realizada no momento inicial, e fotografias digitais foram realizadas semanalmente para análise da redução da área das lesões. Além disto, foram coletadas biópsias de cada lesão nos dias 1, 7, 21 e 28, sendo posteriormente analisadas para diferentes colorações histológicas, as quais objetivaram a detecção de micro-organismos e a análise comparativa do processo de cicatrização. Ainda, biópsias de pele realizadas na região dos bulbos dos talões de 10 animais que não apresentavam lesões foram usadas como controle histológico. Em ambos os tratamentos houve redução da área da lesão, sendo que não houve diferença significante entre os tratamentos. Apesar da regressão significante ao longo do período, no último dia de avaliação, três animais tratados com oxitetraciclina ainda apresentavam pequenas lesões, algo que não foi observado nos animais tratados com PDT. Adicionalmente, o tratamento com oxitetraciclina resultou em leve aumento de colágeno do tipo III e diminuição de colágeno do tipo I, enquanto a PDT promoveu aumento significante da área total de colágeno, em especial do tipo I, em relação ao momento inicial. Espiroquetas foram observadas em todas as lesões, no momento que antecedeu os tratamentos, entretanto não foram visualizadas na pele dos animais saudáveis. Ao término do período de avaliação, cinco lesões tratadas com oxitetraciclina ainda apresentavam espiroquetas, enquanto no grupo tratado com PDT não foi possível evidenciar estes micro-organismos em nenhuma das lesões. Portanto, a PDT mostrou ser uma opção mais eficaz do que a oxitetraciclina no tratamento da DD. / Bovine digital dermatitis (BDD) stands out as one of the most important diseases that affect dairy cows, being responsible for negative economic implications. Photodynamic therapy (PDT) has emerged as an interesting therapeutic option to treat superficial infections on livestock animals, avoiding the overuse of antibiotics, and consequently, the selection of multidrug-resistant pathogens. The aim of this study was to investigate the use of PDT to treat BDD. Twenty BDD lesions located in the pelvic limbs of 16 animals were treated by PDT (350mW / Led; = 660nm &#177; 10nm; A = 13, 20 cm2, I = 120mW/cm2) associated with topical application of methylene blue photosensitizer (300&micro;M; gel presentation; 5 min of pre-irradiation time) or topical application of oxytetracycline (500 mg in 20% solution). Each lesion was treated twice with an interval of 14 days. Lesions were individually classified, and digital photographs were weekly performed to evaluate the reduction of lesions. Additionally, biopsies of each lesion were collected on days 1, 7, 21 and 28; and different histological stains were used to detect microorganisms and compare the healing process after treatmens. Yet, skin biopsies from 10 healthy animals, colleted in the area between heel bulbs, were used as controls. In both treatments, we observed the reduction of lesions area, but there were no significant difference between them. At the last day, three animals treated by topical oxytetracycline still presented small lesions, whereas no lesions were evidenced in the group treated by PDT. The treatment with oxytetracycline resulted in a slight increase in type III collagen and decreased type I collagen levels, while PDT treatment led to a significant increase in the total area of both collagen (mostly type I). Spirochetes were observed in all lesions before treatments but were not detected in the skin of healthy animals. At the end of evaluation period, five lesions treated by topical oxytetracycline still presented spirochetes, whereas in PDT group no spirochetes were evidenced. Therefore, PDT was shown to be a more effective option for BDD when it was compared to topical oxytetracycline treatment.