Pituitary-adrenal function in dogs with acute critical illness

OBJECTIVE: To evaluate pituitary-adrenal function in critically ill dogs with sepsis, severe trauma, and gastric dilatation-volvulus (GDV). DESIGN: Cohort study. ANIMALS: 31 ill dogs admitted to an intensive care unit (ICU) at Washington State University or the University of Pennsylvania; all dogs had acute critical illness for < 48 hours prior to admission. PROCEDURES: Baseline and ACTH-stimulated serum cortisol concentrations and baseline plasma ACTH concentrations were assayed for each dog within 24 hours after admission to the ICU. The change in cortisol concentrations (Delta-cortisol) was calculated for each dog. Morbidity and mortality data were recorded for each patient. RESULTS: Overall, 17 of 31 (55%) acutely critically ill dogs had at least 1 biochemical abnormality suggestive of adrenal gland or pituitary gland insufficiency. Only 1 (3%) dog had an exaggerated response to ACTH stimulation. Dogs with Delta-cortisol < or = 83 nmol/L were 5.7 times as likely to be receiving vasopressors as were dogs with Delta-cortisol > 83 nmol/L. No differences were detected among dogs with sepsis, severe trauma, or GDV with respect to mean baseline and ACTH-stimulated serum cortisol concentrations, Delta-cortisol, and baseline plasma ACTH concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Biochemical abnormalities of the hypothalamic-pituitary-adrenal axis indicative of adrenal gland or pituitary gland insufficiency were common in critically ill dogs, whereas exaggerated responses to ACTH administration were uncommon. Acutely ill dogs with Delta-cortisol < or = 83 nmol/L may be more likely to require vasopressors as part of the treatment plan.     

Identification of nine sequence types of the 16S rRNA genes of Campylobacter jejuni subsp. jejuni isolated from broilers

Background

Campylobacter is the most commonly reported bacterial cause of enteritis in humans in the EU Member States and other industrialized countries. One significant source of infection is broilers and consumption of undercooked broiler meat. Campylobacter jejuni is the Campylobacter sp. predominantly found in infected humans and colonized broilers. Sequence analysis of the 16S rRNA gene is very useful for identification of bacteria to genus and species level. The objectives in this study were to determine the degree of intraspecific variation in the 16S rRNA genes of C. jejuni and C. coli and to determine whether the 16S rRNA sequence types correlated with genotypes generated by PFGE analysis of SmaI restricted genomic DNA of the strains.

Methods

The 16S rRNA genes of 45 strains of C. jejuni and two C. coli strains isolated from broilers were sequenced and compared with 16S rRNA sequences retrieved from the Ribosomal Database Project or GenBank. The strains were also genotyped by PFGE after digestion with SmaI.

Results

Sequence analyses of the 16S rRNA genes revealed nine sequence types of the Campylobacter strains and the similarities between the different sequence types were in the range 99.6–99.9%. The number of nucleotide substitutions varied between one and six among the nine 16S rRNA sequence types. One of the nine 16S rRNA sequence profiles was common to 12 of the strains from our study and two of these were identified as Campylobacter coli by PCR/REA. The other 10 strains were identified as Campylobacter jejuni. Five of the nine sequence types were also found among the Campylobacter sequences deposited in GenBank. The three 16S rRNA genes in the analysed strains were identical within each individual strain for all 47 strains.

Conclusion

C. jejuni and C. coli seem to lack polymorphisms in their 16S rRNA gene, but phylogenetic analysis based on 16S rRNA sequences was not always sufficient for differentiation between C. jejuni and C. coli. The strains were grouped in two major clusters according to 16S rRNA, one cluster with only C. jejuni and the other with both C. jejuni and C. coli. Genotyping of the 47 strains by PFGE after digestion with SmaI resulted in 22 subtypes. A potential correlation was found between the SmaI profiles and the 16S rRNA sequences, as a certain SmaI type only appeared in one of the two major phylogenetic groups.     

Lactic acid bacterial colonization and human rotavirus infection influence distribution and frequencies of monocytes/macrophages and dendritic cells in neonatal gnotobiotic pigs

Despite accumulating knowledge of porcine macrophages and dendritic cells (DCs) from in vitro studies, information regarding monocytes/macrophages and DCs in lymphoid tissues of enteric pathogen-infected neonatal animals in vivo is limited. In this study we evaluated the influence of commensal bacterial [two strains of lactic acid bacteria (LAB), Lactobacillus acidophilus and L. reuteri] colonization and rotavirus infection on distribution and frequencies of monocytes/macrophages and conventional DCs (cDCs) in ileum, spleen and blood. Gnotobiotic pigs were inoculated with LAB and virulent Wa strain human rotavirus (HRV) (LAB+HRV+), HRV only (LAB-HRV+), LAB only (LAB+HRV-) or mock (LAB-HRV-). The cDCs were characterized as SWC3(+)CD11R1(+), whereas monocytes/macrophages were identified as SWC3(+)CD11R1(-) by flow cytometry in the gnotobiotic pigs at 10 days of age. Infection with HRV alone activated/recruited significantly more monocytes/macrophages to the intestine than LAB colonization and 56% versus 28% of these cells expressed CD14. Colonization with LAB alone also significantly increased the frequencies of monocytes/macrophages and cDCs and the CD14 expression on monocytes/macrophages in ileum and spleen compared to the controls. LAB colonization plus HRV infection significantly reduced macrophage and cDC frequencies in spleen compared to LAB colonization or HRV infection alone, suggesting that LAB colonization down-regulated HRV- infection-induced monocyte/macrophage activation/recruitment at the systemic lymphoid tissue. These results illustrated the distribution of porcine monocytes/macrophages and cDCs and the frequencies of CD14 expression on these cells in intestinal and systemic lymphoid tissues in the early stage of immune responses to intestinal colonization by LAB versus infection by an enteric pathogen HRV and will facilitate further in vivo studies on functional characterization of these immune cells in neonates.     

Body temperature,activity patterns and hunting in free‐living cheetah: biologging reveals new insights

As one of the few felids that is predominantly diurnal, cheetahs (Acinonyx jubatus) can be exposed to high heat loads in their natural habitat. Little is known about long‐term patterns of body temperature and activity (including hunting) in cheetahs because long‐term concurrent measurements of body temperature and activity have never been reported for cheetahs, or, indeed, for any free‐living felid. We report here body temperature and locomotor activity measured with implanted data loggers over 7 months in 5 free‐living cheetahs in Namibia. Air temperature ranged from a maximum of 39 °C in summer to ?2 °C in winter. Cheetahs had higher (～0.4 °C) maximum 24‐h body temperatures, later acrophase (～1 h), with larger fluctuations in the range of the 24‐h body temperature rhythm (approximately 0.4 °C) during a hot‐dry period than during a cool‐dry period, but maintained homeothermy irrespective of the climatic conditions. As ambient temperatures increased, the cheetahs shifted from a diurnal to a crepuscular activity pattern, with reduced activity between 900 and 1500 hours and increased nocturnal activity. The timing of hunts followed the general pattern of activity; the cheetahs hunted when they were on the move. Cheetahs hunted if an opportunity presented itself; on occasion they hunted in the midday heat or in total darkness (new moon). Biologging revealed insights into cheetah biology that are not accessible by traditional observer‐based techniques.     

Ferret hematology and related disorders

This article summarizes the general topic of ferret hematology, including discussion of restraint for phlebotomy and phlebotomy sites, red and white blood cell morphology, interpretation of the hemogram, and normal and abnormal factors affecting the hemogram. In addition, the apparent lack of blood groups and techniques for bone marrow aspirates and blood transfusion are addressed. There is much still to be learned about the ferret and its diseases. We often depend on tests as simple as the complete blood cell count to help guide us in our diagnosis and treatments of this patient.     

A real-time polymerase chain reaction assay for the detection of the myxozoan parasite Henneguya ictaluri in channel catfish

Proliferative gill disease (PGD), caused by the myxozoan parasite Henneguya ictaluri, is the most prevalent parasitic infection affecting commercial channel catfish (Ictalurus punctatus) aquaculture. There are currently no effective chemotherapeutic or biological control measures for PGD, which often peaks during the spring and fall when water temperatures are between 16-25 degrees C. The current diagnostic techniques of gross examination of gill clip wet mounts and histopathology are subject to false-negatives during the early stages of infection, and the quantifiable nature of end-point polymerase chain reaction (PCR) is subjective. Consequently, a rapid and more sensitive quantitative real-time PCR assay was developed for the detection of H. ictaluri during the early stages of infection in channel catfish. A 23 base-pair TaqMan probe was designed based on previously published H. ictaluri PCR protocols. The sensitivity of the assay was the equivalent of a single H. ictaluri actinospore, and in a pond challenge study, quantitative real-time PCR proved to be more sensitive than gross examination, microscopic examination of gill clip wet mounts, and histopathologic examination of gill tissue sections. Future applications of this assay will focus on developing methodologies to be used in conjunction with current pond-monitoring protocols to evaluate potential treatments and better manage this significant seasonal disease.