First identification and characterization of ovine gammaherpesvirus type 2 in horses and artiodactyla from an outbreak of malignant catarrhal fever in Mexico.

Ovine gammaherpesvirus 2 (OvHV-2), a member of the genus Macavirus, causes sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease affecting a wide variety of ungulates in addition to horses. This study described an outbreak of SA-MCF in Mexico and the identification of the OvHV-2 virus in primary rabbit testis cultures through the generation of intranuclear inclusion bodies, syncytia, immunofluorescence (IF), immunocytochemistry (ICC), immunohistochemistry (IHC), endpoint polymerase chain reaction (PCR), and partial sequencing of the ORF75 gene. The animals involved in this outbreak showed mucogingival ulcers in the vestibule of the mouth and tongue, hypersalivation, corneal opacity, reduced food consumption, and weight loss of variable severity. These clinical signs and the histopathological findings suggested the diagnosis of SA-MCF. Buffy coat fractions from the anticoagulated blood samples of ill animals were collected and analyzed by PCR. Positive buffy coats were used to inoculate the primary cell cultures of rabbit testis to identify the virus. Small clusters of refractile cytomegalic cells, characteristic of viral cytopathic effects, were observed between 48 and 72 h post-infection. Furthermore, intranuclear acidophilic inclusion bodies (IBs) were identified in the inoculated primary culture cells, and the cytoplasm showed immunoreactivity with hyperimmune rabbit serum against OvHV-2. Moreover, in the liver histological sections from sick deer, immunoreactive juxtanuclear IBs were identified with the same rabbit hyperimmune serum. The obtained sequences were aligned with the OvHV-2 sequences reported in GenBank and revealed a nucleotide identity higher than 98%. Based on the evidence provided in this study, we conclude that the outbreak of SA-MCF in the municipality of Tequisquiapan in the state of Queretaro, Mexico, was caused by OvHV-2. This is the second study reporting that horses are susceptible to OvHV-2 infection and can develop SA-MCF. We identified for the first time in Mexico, the presence of OvHV-2 in buffy coats from horses and Artiodactyla.

GspD, The Type II Secretion System Secretin of Leptospira, Protects Hamsters against Lethal Infection with a Virulent L. interrogans Isolate.

The wide variety of pathogenic Leptospira serovars and the weak protection offered by the available vaccines encourage the search for protective immunogens against leptospirosis. We found that the secretin GspD of the type II secretion system (T2S) of Leptospira interrogans serovar Canicola was highly conserved amongst pathogenic serovars and was expressed in vivo during infection, as shown by immunohistochemistry. Convalescent sera of hamsters, dogs, and cows showed the presence of IgG antibodies, recognizing a recombinant version of this protein expressed in Escherichia coli (rGspDLC) in Western blot assays. In a pilot vaccination study, a group of eight hamsters was immunized on days zero and 14 with 50 µg of rGspDLC mixed with Freund's incomplete adjuvant (FIA). On day 28 of the study, 1,000 LD50 (Lethal Dose 50%) of a virulent strain of Leptospira interrogans serovar Canicola (LOCaS46) were inoculated by an intraoral submucosal route (IOSM). Seventy-five percent protection against disease (p = 0.017573, Fisher's exact test) and 50% protection against infection were observed in this group of vaccinated hamsters. In contrast, 85% of non-vaccinated hamsters died six to nine days after the challenge. These results suggest the potential usefulness of the T2S secretin GspD of Leptospira as a protective recombinant vaccine against leptospirosis.

Intestinal histopathological changes in a porcine model of pneumoperitoneum-induced intra-abdominal hypertension.

BACKGROUND: Low splanchnic perfusion is an immediate effect of pneumoperitoneum-induced intra-abdominal hypertension (IAH). Anatomical structure results in the intestinal mucosa being the area most sensitive to hypoperfusion. The relationship between intestinal injury and clinical parameters of tissue perfusion [abdominal perfusion pressure (APP), gastric intramucosal pH (pHi) and lactic acid (Lc)] has not been previously studied. This study aimed to monitorize intestinal pathogenesis through sequential ileal biopsies and to measure APP, pHi, and Lc levels at different pneumoperitoneum-induced intra-abdominal pressures (20, 30, and 40 mmHg) to evaluate the potential relationships between them. MATERIALS AND METHODS: Fifty pigs were divided into four groups; a control group (C) and three experimental groups with different pneumoperitoneum-induced levels [20 mmHg (G20), 30 mmHg (G30), and 40 mmHg (G40)], that were maintained for 3 and 5 h. APP, pHi, and Lc were measured and ileal biopsies taken laparoscopically every 30 min. The mucosal damage was graded using the standardized Park's Score and animals were classified as injured (I+) or uninjured (I-). RESULTS: Different histopathological lesions were observed in groups G20, G30, and G40 but no damage observed in group C. A 33.3% of animals in G20 and G30 were I+ after 3 h, while 93.3% were injured in G40. After 5 h, histopathological lesions were no longer seen in some animals in G20 and only 10% were I+. Conversely, in G30 I+ pigs increased to 80% while those in G40 remained at 93.3% I+. The I+ animals had significantly lower APP and pHi than those I-. Lc was the clinical parameter that showed the earliest differences, with significantly higher figures in I+ animals. CONCLUSIONS: The evolution of intestinal injuries from pneumoperitoneum-induced IAH depends on the degree of IAP. These damages may be associated with decreases in APP and pHi, and increases in Lc.

Time-course evaluation of intestinal structural disorders in a porcine model of intra-abdominal hypertension by mechanical intestinal obstruction.

BACKGROUND: A mechanical intestinal obstruction (MIO) can generate intraabdominal hypertension (IAH) that is life threatening. The intestines are very sensitive to IAH since the low splanchnic perfusion causes intestinal hypoxia, local acidosis and bacterial translocations. This may lead to acute intestinal distress syndrome (AIDS). The identification of intestinal injuries during IAH and its correlation with clinical parameters as the abdominal perfusion pressure (APP), the gastric intramucosal pH (pHi) and lactic acid (Lc) are still unknown. This study aimed to evaluate the sequence of intestinal histopathological findings in an MIO model and to analyze potential relationships with parameters currently used in clinical practice (APP, pHi and Lc). MATERIAL AND METHODS: Twenty pigs were divided into three groups: a control group (n = 5) and two experimental groups with 20 mmHg (G1, n = 10) and 30 mmHg (G2, n = 5) of IAH by MIO. The pressures were maintained for 3 hours, except in 5 animals in G1 where it was maintained for 5 hours. The APP, pHi and LA were recorded and biopsies of the terminal ileum were taken every 30 minutes in all groups. The intestinal damage was graded according to the Park Score. RESULTS: Intestinal injuries were found in 42.9% of pigs in the experimental groups. The lesions were independent of the level and duration of IAH. Although APP and pHi were slightly lower in injured animals (I +) of G1 and G2, there were no significant differences among those uninjured (I-). Lc was significantly increased in all I+ pigs from the onset of IAH. CONCLUSION: The IAH by MIO causes intestinal lesions from the first 30 minutes with concurrent decreases in APP and pHi and increases in Lc. Lc could be the best clinical parameter related to intestinal damages with a clear difference between I + and I- animals.

Vulvovaginitis y balanopostitis pustular sugerente a herpesvirus caprino-1 en cabras (Querétaro, México) / Pustular vulvovaginitis and balanoposthitis suggestive of caprine herpesvirus-1 infection in goats (Queretaro, Mexico)

Infectious pustular vulvovaginitis and balanoposthitis in goats is caused by caprine herpesvirus 1 (CpHV-1), from the Herpesviridae family Alphaherpesvirinae subfamily, sometimes produces abortion, neonatal enteritis and respiratory disease in adult goats. In a herd of 244 dairy and meat goats, physical examinations were performed in does and bucks, presenting vulvar and preputial lesions. Necropsies were done in four discarded animals (one male and two females) and one stillborn; immunohistochemistry (IHC) with bovine herpesvirus 1 (BHV-1) antibodies in prepuce and vulva samples was carried out. Penis and prepuce exfoliative cytology was carried out in six bucks. Prepuce biopsies were collected for electron microscopy and viral isolation. Macroscopically, moderate to severe coalescent multifocal pustular and ulcerative vulvovaginitis was observed; and severe coalescent multifocal pustular and ulcerative balanoposthitis. Microscopically, different degrees of inflammatory lesions with presence of eosinophilic and amphophilic intranuclear inclusion bodies were present. In electron microscopy, the prepuce samples and MBDK cell culture showed several intranuclear viral particles of 150 to 230 nm size. There was slight epithelial cell positivity in IHC with BHV-1 antibodies in vulva and prepuce histological cuts made at necropsy. In the viral isolate was observed a cytopathic effect and the presence of viral particles by microscopy electronic suggesting herpes virus. This is the first documented report suggesting the presence of herpes virus outbreak in caprine herds in Mexico.

La vulvovaginitis y balanopostitis pustular infecciosa en cabras es producida por herpesvirus caprino 1 (CpHV-1), de la familia Herpesviridae subfamilia Alphaherpesvirinae, que ocasionalmente produce aborto, enteritis neonatal y enfermedad respiratoria en las cabras adultas. En un rebaño de 244 cabras de genotipo lechero y cárnico; se realizaron exámenes físicos de hembras y sementales en los que se observaron lesiones vulvares y prepuciales. Se realizó la necropsia de cuatro animales adultos de desecho (dos hembras y un macho) y un neonato muerto; se realizó inmunohistoquímica (IHQ) con anticuerpos de herpesvirus bovino 1 (BHV1) en muestras de prepucio y vulva. Se analizaron las citologías exfoliativas de pene y prepucio de 6 sementales. Se recolectaron y analizaron biopsias de prepucio para microscopía electrónica y aislamiento viral. Macroscópicamente, en las hembras se observó vulvovaginitis pustular y ulcerativa de moderada a grave multifocal coalescente, además de balanopostitis pustular y ulcerativa grave multifocal coalescente en los machos. Microscópicamente, se presentaron lesiones inflamatorias en diferentes grados, con presencia de cuerpos de inclusión intranucleares eosinofílicos y amfofílicos. En microscopía electrónica, las muestras de prepucio y cultivo celular de MBDK presentaron numerosas partículas virales intranucleares de un tamaño de 150 a 230 nm. En los cortes histológicos de prepucio y vulva de las necropsias se detectó una ligera positividad en las células epiteliales con anticuerpos BHV-1. En el aislamiento viral se observó efecto citopático, y la presencia de partículas virales mediante microscopía electrónica sugerentes a herpes virus. Este es el primer informe documentado que sugiere la presencia de herpes virus en rebaños caprinos de México.