Molecular detection of Mycoplasma ovis in an outbreak of hemolytic anemia in sheep from Veracruz, Mexico.

Mycoplasma ovis is a small, pleiotropic bacterium, which parasitizes the external surface of erythrocytes of several species of artiodactyl mammals, especially sheep and goats. We here report an outbreak of ovine mycoplasmosis in a sheep flock of a private ranch (Universidad Veracruzana) in Veracruz, Mexico. For the identification of Mycoplasma and other hemoparasitic bacterial agents, we stained blood smears with the DiffQuick® technique and additionally amplified several fragments of 16S rDNA gene. We detected the presence of morulas in erythrocytes from 30 sick female adult sheep, and found Mycoplasma ovis DNA in all of them. Furthermore, three of these animals also tested positive for Anaplasma ovis. Our findings represent the first record of M. ovis and A. ovis in an outbreak of hemolytic anemia in a sheep flock, leading to severe livestock loss in a ranch of Mexico. This study highlights the importance of establishing an active surveillance of both pathogens in the country.

New insight into Wolbachia epidemiology: its varying incidence during the host life cycle can alter bacteria spread.

Wolbachia is an obligate endosymbiont whose spread depends mainly on its capacity to alter host reproduction by, for instance, cytoplasmic incompatibility. Several mathematical models have been developed to explain the dynamics of bacterial spread, because of its applied interest. However, some aspects of the host's and bacterium's biology have not been considered in modelling: for instance, changes in Wolbachia proportions during the host's life cycle have been observed in several species, including Drosophila sp., Nasonia sp. and Aedes sp. (Diptera), but also in the grasshopper Chorthippus parallelus (Orthoptera), the species studied in this article. These changes influence the proportion of incompatible crosses and, consequently, infection prevalence in subsequent generations. In this paper, we are interested in ascertaining whether these changes in the infection proportions during the host's life cycle can influence the dynamics of the spread of these bacteria. We have examined its consequences using a mathematical model to predict the evolution of Wolbachia infection frequencies. The simulations were validated by experimental field data from C. parallelus. The main outcome is that those changes above mentioned might affect long-term infection spread, with possible consequences for the current distribution of Wolbachia and the way it affects its host's reproduction.

[Update on gluteus medius syndrome]. / Actualización en el síndrome del glúteo medio.

Back pain and/or gluteal region pain is a frequent complaint in primary care and often is difficult to determine their origin. When a patient consults us for this reason we tend to direct the focus to the study of bone and nerve structures, without considering that in a large number of cases the myofascial system is involved. In a study with 250 patients in order to determine the prevalence of tendinosis and tear of the gluteus medius or minimus muscles, was found by MRI that 14% of patients who went to the doctor for pain in the buttock, hip or groin had this type of injury in any of the muscles mentioned (1). In these cases a diagnosis and early treatment with injections is essential to prevent progression to persistent pain and decreased muscle function.

Actualización en el síndrome del glúteo medio / Update on Gluteus Medius Syndrome

El dolor de espalda y/o región glútea es un motivo de consulta frecuente en atención primaria y en muchas ocasiones resulta difícil precisar su origen. Cuando un paciente consulta por este motivo solemos dirigir el foco de atención hacia el estudio de las estructuras óseas y nerviosas, sin tener en cuenta que en un gran número de casos está implicado el sistema miofascial. En un estudio realizado en 250 pacientes con el objetivo de determinar la prevalencia de tendinosis y roturas del glúteo medio o menor, se comprobó por medio de RM que el 14% de los pacientes que acudían al médico por dolor en la nalga, cadera o ingle presentaban este tipo de lesión en alguno de los músculos mencionados. En estos casos un diagnóstico y tratamiento precoz con infiltraciones es fundamental para evitar la progresión a un dolor persistente y disminución de la función muscular (AU)

Back pain and/or gluteal region pain is a frequent complaint in primary care and often is difficult to determine their origin. When a patient consults us for this reason we tend to direct the focus to the study of bone and nerve structures, without considering that in a large number of cases the myofascial system is involved. In a study with 250 patients in order to determine the prevalence of tendinosis and tear of the gluteus medius or minimus muscles, was found by MRI that 14% of patients who went to the doctor for pain in the buttock, hip or groin had this type of injury in any of the muscles mentioned (1). In these cases a diagnosis and early treatment with injections is essential to prevent progression to persistent pain and decreased muscle function (AU)

Detection of Spiroplasma and Wolbachia in the bacterial gonad community of Chorthippus parallelus.

We have recently detected the endosymbiont Wolbachia in multiple individuals and populations of the grasshopper Chorthippus parallelus (Orthoptera: acrididae). This bacterium induces reproductive anomalies, including cytoplasmic incompatibility. Such incompatibilities may help explain the maintenance of two distinct subspecies of this grasshopper, C. parallelus parallelus and C. parallelus erythropus, which are involved in a Pyrenean hybrid zone that has been extensively studied for the past 20 years, becoming a model system for the study of genetic divergence and speciation. To evaluate whether Wolbachia is the sole bacterial infection that might induce reproductive anomalies, the gonadal bacterial community of individuals from 13 distinct populations of C. parallelus was determined by denaturing gradient gel electrophoresis analysis of bacterial 16S rRNA gene fragments and sequencing. The study revealed low bacterial diversity in the gonads: a persistent bacterial trio consistent with Spiroplasma sp. and the two previously described supergroups of Wolbachia (B and F) dominated the gonad microbiota. A further evaluation of the composition of the gonad bacterial communities was carried out by whole cell hybridization. Our results confirm previous studies of the cytological distribution of Wolbachia in C. parallelus gonads and show a homogeneous infection by Spiroplasma. Spiroplasma and Wolbachia cooccurred in some individuals, but there was no significant association of Spiroplasma with a grasshopper's sex or with Wolbachia infection, although subtle trends might be detected with a larger sample size. This information, together with previous experimental crosses of this grasshopper, suggests that Spiroplasma is unlikely to contribute to sex-specific reproductive anomalies; instead, they implicate Wolbachia as the agent of the observed anomalies in C. parallelus.

Hybridization and speciation.

Hybridization has many and varied impacts on the process of speciation. Hybridization may slow or reverse differentiation by allowing gene flow and recombination. It may accelerate speciation via adaptive introgression or cause near-instantaneous speciation by allopolyploidization. It may have multiple effects at different stages and in different spatial contexts within a single speciation event. We offer a perspective on the context and evolutionary significance of hybridization during speciation, highlighting issues of current interest and debate. In secondary contact zones, it is uncertain if barriers to gene flow will be strengthened or broken down due to recombination and gene flow. Theory and empirical evidence suggest the latter is more likely, except within and around strongly selected genomic regions. Hybridization may contribute to speciation through the formation of new hybrid taxa, whereas introgression of a few loci may promote adaptive divergence and so facilitate speciation. Gene regulatory networks, epigenetic effects and the evolution of selfish genetic material in the genome suggest that the Dobzhansky-Muller model of hybrid incompatibilities requires a broader interpretation. Finally, although the incidence of reinforcement remains uncertain, this and other interactions in areas of sympatry may have knock-on effects on speciation both within and outside regions of hybridization.

Importancia del hoyuelo sacro: marcador cutáneo de disrafismo espinal cerrado / Importance of the sacral dimple: cutaneous marker of oc- cult spinal dysraphism

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