Molecular Detection of in Vaginal Swab Samples from Sheep That Aborted.

, an obligate intracellular bacterium, is the etiological agent of Q fever in humans and one of the causes of abortion in small ruminants. Although coxiellosis is considered an exotic disease, there are a few reports in Mexico. The objective of this work was to determine the presence of .

Increased Brucella abortus asRNA_0067 expression under intraphagocytic stressors is associated with enhanced virB2 transcription.

Intracellular pathogens like Brucella face challenges during the intraphagocytic adaptation phase, where the modulation of gene expression plays an essential role in taking advantage of stressors to persist inside the host cell. This study aims to explore the expression of antisense virB2 RNA strand and related genes under intracellular simulation media. Sense and antisense virB2 RNA strands increased expression when nutrient deprivation and acidification were higher, being starvation more determinative.

Enhancing Therapeutic Efficacy against Infection in a Murine Model Using Rifampicin-Loaded PLGA Nanoparticles.

The efficacy of rifampicin encapsulated in poly(lactic--glycolic acid) (PLGA) nanoparticles was evaluated for the treatment of BALB/c mice experimentally infected with . The PLGA nanoparticles loaded with rifampicin (RNP) were prepared using the single emulsification-solvent evaporation technique, resulting in nanoparticles with a hydrodynamic diameter of 138 ± 6 nm. The zeta potential and polydispersity index values indicated that the system was relatively stable with a narrow size distribution.

Effect of the JLM Strain Against Strains in Ripened Cheese.

This study evaluated the antagonistic effect of the JLM strain isolated from , against RB51, S19, and 2308 strains, during the manufacture of soft-ripened cheese. First, the tolerance of JLM was tested with pH values and bile salt concentrations for 3 h to simulate digestive tract conditions. The antagonistic effect against strains was evaluated through double-layer diffusion and agar well diffusion assays.

Evaluation of the Fluorescence Polarization Assay for the Diagnosis of Brucellosis in Goat Milk.

The milk ring test is a detection assay for antibodies against Brucella in bovine milk. It has good sensitivity but tends to give false positive results. In this study, we standardized the application of the fluorescence polarization assay (FPA) for the detection of antibodies against B.

Survival of RB51 and S19 Vaccine Strains in Fresh and Ripened Cheeses.

Brucellosis is a zoonotic infection caused by the consumption of contaminated raw milk and dairy products. This study aims to compare survival rates of RB51 and S19 vaccine strains to that of virulent 2308 strain during the manufacture of fresh and ripened cheeses. To do this, we inoculated fresh pasteurized milk with RB51, S19, or 2308 at a 6 × 10 colony-forming unit per milliliter concentration during the cheese making process.

Brucella melitensis invA gene (BME_RS01060) transcription is promoted under acidic stress conditions.

The invA gene of Brucella melitensis codes for a NUDIX (nucleoside diphosphate linked to moiety X) hydrolase related to invasiveness. The objective of this work was to evaluate invA transcription under acidic conditions. The invA gene transcription was up regulated at pH 3 and pH 5 observed with semiquantitative real-time PCR in B.

Edaphoclimatic seasonal trends and variations of the spp. infection in Northwestern Mexico.

Currently, spp. is the bacterium causing the highest number of food-borne diseases (FADs) in the world. It is primarily associated with contaminated water used to that irrigates crops from intensive livestock farming.

Comparative proteomic analysis of outer membrane vesicles from Brucella suis, Brucella ovis, Brucella canis and Brucella neotomae.

Gram-negative bacteria release nanovesicles, called outer membrane vesicles (OMVs), from their outer membrane. Proteomics has been used to determine their composition. OMVs contain proteins able to elicit an immune response, so they have been proposed as a model to develop acellular vaccines.

Serotyping versus genotyping in infected sheep and goats with small ruminant lentiviruses.

Despite SRLV infection being endemic in Mexico, there is little information regarding which genotypes are present. We compared serotyping and PCR-sequencing results from sheep and goats infected with SRLV. We separated plasma and peripheral blood leukocytes (PBL) from 1940 blood samples from sheep and goats from 12 states across Mexico.

Outer Membrane Vesicles From Modulate Immune Response and Induce Cytoskeleton Rearrangement in Peripheral Blood Mononuclear Cells.

Similar to what has been described in other Gram-negative bacteria, releases outer membrane vesicles (OMVs). OMVs from 16M and the rough-mutant VTRM1 were able to induce a protective immune response against virulent in mice models. The presence of some proteins which had previously been reported to induce protection against were found in the proteome of OMVs from 16M.

Polymorphisms in Carbonic Anhydrase II Mediate CO Dependence and Fitness .

Some isolates are known to require an increased concentration of CO for growth, especially in the case of primary cultures obtained directly from infected animals. Moreover, the different species and biovars show a characteristic pattern of CO requirement, and this trait has been included among the routine typing tests used for species and biovar differentiation. By comparing the differences in gene content among different CO-dependent and CO-independent strains, we have confirmed that carbonic anhydrase (CA) II is the enzyme responsible for this phenotype in all the strains tested.

is Internalized by Bovine Endometrial Epithelial Cells.

is an important venereal pathogen of cattle that causes infertility and abortions. It is transmitted during mating, and it travels from the vagina to the uterus; therefore, an important cell type that interacts with are endometrial epithelial cells. Several virulence factors have been identified in the genome of , such as adhesins, secretion systems, and antiphagocytic layers, but their expression is unknown.

Dendritic cells and Brucella spp. interaction: the sentinel host and the stealthy pathogen.

As dendritic cells (DCs) are among the first cells to encounter antigens, these cells trigger both innate and T cell responses, and are the most potent antigen-presenting cells. Brucella spp., which is an intracellular facultative and stealthy pathogen, is able to evade the bactericidal activities of professional phagocytes.

First genome sequencing and comparative analyses of strains from Mexico.

is a pathogenic bacterium which has been rapidly spreading all over the world, causing economic losses in the agricultural sector and sporadically infecting humans. Six strains were isolated from goats, sheep, and horses with distinct abscess locations. For the first time, Mexican genomes of this bacterium were sequenced and studied in silico.

Survival of Brucella abortus aqpX mutant in fresh and ripened cheeses.

The objective of this work was to evaluate the survival of a Brucella abortus aqpX mutant during the elaboration and conservation of fresh and ripened cheeses at 4 °C and 24 °C. The pH values and water activity were monitored for each type of cheese. The fresh cheese was elaborated with raw milk inoculated with 6×10⁸ colony-forming units (CFU)/mL each of parental and mutant strain.

Infection of California sea lions (Zalophus californianus) with terrestrial Brucella spp.

Infections with Brucella ceti and pinnipedialis are prevalent in marine mammals worldwide. A total of 22 California sea lions (Zalophus californianus) were examined to determine their exposure to Brucella spp. at San Esteban Island in the Gulf of California, Mexico, in June and July 2011.

The invA gene of Brucella melitensis is involved in intracellular invasion and is required to establish infection in a mouse model.

Some of the mechanisms underlying the invasion and intracellular survival of B. melitensis are still unknown, including the role of a subfamily of NUDIX enzymes, which have been described in other bacterial species as invasins and are present in Brucella spp. We have generated a mutation in the coding gene of one of these proteins, the invA gene (BMEI0215) of B.

Milk yield and reproductive performance of brucellosis-vaccinated but seropositive Holstein cows.

The aim of this research was to study if seropositivity for brucellosis in vaccinated cows against this disease hampers reproductive performance and milk production in high-yielding Holstein cows. For this purpose 1,026 healthy cows and 372 cows seropositive for brucellosis were enrolled in this study. Cows positive to card test and subsequently to the rivanol test were further subjected to the radial immunodiffusion (RID) test.

Isolation of a field strain of Brucella abortus from RB51-vaccinated- and brucellosis-seronegative bovine yearlings that calved normally.

A study was carried out in Pichucalco, Chiapas (Mexico) to determine whether recently calved cows or those that aborted shed Brucella. Serological diagnosis of brucellosis was made in all animals (209). Six of the cows that calved normally and two that aborted underwent a bacteriological study of milk and vaginal exudate.

Isolation of Histophilus somni from the nasal exudates of a clinically healthy adult goat.

Methods: The nasal exudate from 42 goats of the Mixteca Region in the state of Puebla, Mexico, was evaluated. A strain was isolated after 4 days of incubation. This strain was identified according to its phenotypic characteristics and by means of a species-specific polymerase chain reaction (PCR), as well as by sequencing of the amplified product.

Pathogenicity of different strains of Histophilus somni in the experimental induction of ovine epididymitis.

The purpose of this study was to determine any differences in pathogenicity when sheep are experimentally infected with different Histophilus somni isolates: a) 2336 bovine origin strain; b) an isolate from ram orchitis and epididymitis; c) an isolate from the brain of a sheep with neurological signs; d) an isolate from the vagina of a clinically healthy ewe. A total of 20 rams divided in groups of 5 animals each were inoculated in the epididymis with 1 x 10(7) CFU/mL of H. somni; a negative control group of 5 rams was used.

Cyclic beta-1,2-glucan is a Brucella virulence factor required for intracellular survival.

Pathogenic brucella bacteria have developed strategies to persist for prolonged periods of time in host cells, avoiding innate immune responses. Here we show that the cyclic beta-1,2-glucans (CbetaG) synthesized by brucella is important for circumventing host cell defenses. CbetaG acted in lipid rafts found on host cell membranes.

Protection of Brucella abortus RB51 revaccinated cows, introduced in a herd with active brucellosis, with presence of atypical humoral response.

It is a dogma, that RB51 vaccination does not induce antibodies that interfere with Brucellosis diagnosis, therefore any animal positive to serological test is considered as an infected animal. To determine protection against Brucellosis virulent field strain, 35 pregnant cows from a free-Brucellosis herd, previously vaccinated as calves with 1 x 10(10) CFU of RB51, were revaccinated with RB51 reduced dose, and then introduced into a herd with an active outbreak. Seventeen cows resulted positive in card test after revaccination.

Intracellular trafficking study of a RB51 B. abortus vaccinal strain isolated from cow milk.

Brucella is responsible for one of the major worldwide zoonoses. Over the last century, several vaccines have been used against brucellosis. Among these, the rough vaccine Brucella abortus RB51 was introduced with the idea that it would not interfere with the diagnosis of brucellosis.