Reclassification of German, British and Dutch isolates of so-called Pasteurella multocida obtained from pneumonic calf lungs

The taxonomic relationship of 131 strains previously identified as Pasteurella multocida obtained from calf pneumonia in West Germany, United Kingdom and Netherlands was investigated by extended phenotypic and limited genotypic characterization. Twenty-four strains were classified as P. multocida ssp. multocida, 15 strains as P. avium biovar 2 and 13 strains as P. canis biovar 2. Sixty-five and five strains were tentatively classified as ornithine negative P. multocida ssp. multocida and P. multocida ssp. septica, respectively. Genetic investigations showed that ornithine negative strains of P. multocida were related on species level. Less genomic binding was found between an ornithine negative strain of P. multocida ssp. septica and the type strains of the three subspecies of P. multocida. The taxonomic position of ornithine negative strains of P. multocida is still under investigation. The taxonomic position of the remaining nine strains is uncertain underlining the need for genotypic characterization within the genus Pasteurella to aid in defining single species by phenotypic tests.     

Effect of short chain fatty acids on the performance and intestinal weight in germ-free and conventional chicks

1. In experiment 1, the performance and tissue weights of germ-free (GF) and conventional (CV) chicks fed on diets containing 25.4 g acetic acid/kg diet (AD) or 25.4 g kaolin/kg diet (KD) were investigated. Body weight gain in GF chicks was significantly higher on the AD, but significantly lower on the KD compared with their CV counterparts. The values for food efficiency, protein retention and energy retention followed a similar pattern to that of the body weight gain. 2. The weights of all sections of the intestine except the colon were significantly greater in CV chicks. In CV but not in GF birds the jejunum and ileum were heavier from birds fed on the AD than from those on the KD diet. 3. In experiment 2, the influence of butyric acid administration on the weight of some organs in chicks was investigated. The weight of duodenum, jejunum and ileum was significantly increased by intraperitoneal administration of butyric acid (2 ml of 100 mM solution/d) for 4 d, but no significant effect was observed by oral administration. 4. It might be suggested that short chain fatty acids such as acetic and butyric acids formed by bacterial action in the crop and subsequently absorbed are at least partly responsible for the heavier gut weight in CV birds.     

Cerebellar degeneration in dairy calves: clinical, pathologic, and serologic features of an epizootic caused by bovine viral diarrhea virus

Three of nine dairy calves born in the spring/summer wee severely ataxic at birth. Necropsy of the 3 affected calves revealed severe cerebellar degeneration (hypoplasia). Clinical signs were inapparent in the adult cows. Serum neutralization titers of the cows and calves indicated high bovine viral diarrhea titers.     

The Effects of Cesarean Section Anesthesia on Heat Loss and Heat Production in the Newborn Rabbit

The newborn of some smaller animals rely upon heat produced by nonshivering thermogenesis in the brown fat to prevent a fall in body temperature after birth. Because of their pharmacological properties, some drugs may affect nonshivering thermogenesis. Therefore, in this study, the ability of newborn rabbits delivered under Innovar-Vet, ketamine hydrochloride, methoxyflurane and epidural anesthesia to maintain the rectal, subcutaneous interscapular and lumbar temperature was investigated at an ambient temperature of 35°C or 22°C and the results compared with control newborns delivered without anesthesia. When the newborns were exposed to 35°C, the anesthetics studied had no effect on the ability of the newborn to maintain the rectal temperature and the subcutaneous temperature over the interscapular fat pad was similar to the lumbar subcutaneous temperature thereby indicating that nonshivering thermogenesis was not activated. However, at an ambient temperature of 22°C Innovar-Vet or methoxyflurane reduced the temperature difference between interscapular and lumbar temperatures to 1.6°C compared to 2.5°C in controls and the difference between core temperature and ambient temperature to 3.5°C greater compared to 7.5°C in controls. Ketamine hydrochloride or lidocaine hydrochloride plus meperidine has less effect because these compounds lack adrenergic blocking properties. These data suggest that newborns delivered under anesthetics or tranquillizers that have adrenergic blocking properties require a warm (35°C) environment to prevent a fall in core temperature.     

Esophageal ectasia in a quarterhorse colt

A one month old Quarterhorse colt was presented after a week history of bilateral nasal discharge and respiratory difficulty. The cervical esophagus was greatly dilated, tortuous and filled with diluted milk. A nasogastric tube could not be passed beyond the base of the heart. An aspiration pneumonia was found at postmortem examination and the esophageal segment from the pharynx to the base of the heart was dilated, thin-walled, had degenerative muscular changes, and a reduction in size and number of ganglion cells of the myenteric plexus. Muscular hypertrophy of the terminal esophagus had reduced its lumen size. Some similarities and disparities of this condition to achalasia of man and megaesophagus of dogs are discussed.     

Cover Image,Volume 16, Issue 3

The cover image, by K. Sakai et al., is based on the Original Article Association of tumour‐infiltrating regulatory T cells with adverse outcomes in dogs with malignant tumours, DOI: 10.1111/vco.12383 .

     

Genetic diversity,anti‐microbial resistance,plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti‐microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA‐types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33‐year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti‐microbial treatments used to control S. Dublin infections in humans in Brazil.