Haematological and biochemical investigations of diseased koalas (Phascolarctos cinereus)

Haematological and biochemical investigations were performed on 14 koalas with uncomplicated cystitis, 8 with complicated cystitis, 8 with conjunctivitis, 8 with lymphosarcoma, and 14 with miscellaneous diseases. Changes were limited and inconsistent in individual koalas with uncomplicated cystitis and conjunctivitis. In contrast, individual koalas with complicated cystitis were more likely to have anaemia, leukocytosis due to neutrophilia, hypoproteinaemia due to hypoalbuminaemia, and azotaemia due to elevated urea concentration. Although these changes were non-specific they did allow assessment of prognosis for survival and response to treatment. Koalas with lymphosarcoma were invariably anaemic, leukaemic, azotaemic and hypoalbuminaemic. Elevated enzymes (aspartate transaminase [AST]. lactate dehydrogenase [LD] and gamma glutamyl transferase [GGT]) were more common in koalas with lymphosarcoma. Koalas affected by miscellaneous conditions showed variable changes but once again anaemia, leukocytosis, azotaemia, elevated AST and LD, and hypoalbuminaemia were not uncommon. On the basis of these findings a minimal profile is suggested for the investigation of sick koalas and would include haematocrit, total and differential leukocyte counts, urea, total protein and albumin concentrations and AST, GGT and LD activities.     

Chromosome and plasmid-encoded N-acyl homoserine lactones produced by Agrobacterium vitis wildtype and mutants that differ in their interactions with grape and tobacco

Agrobacterium vitis causes crown gall disease on grapevines. It also induces a specific necrosis on grape roots and a hypersensitive response (HR) on tobacco that are regulated by a complex quorum-sensing regulatory system. Strain F2/5 produces at least six N-acyl-homoserine lactones (AHLs) that function as signal molecules in quorum-sensing. The AHLs differ in acyl side chain length (8–16 carbons) as determined by gas chromatography/mass spectrometry and electrospray ionization tandem mass spectrometry. Mutant derivatives of F2/5 differ in ability to cause necrosis and the HR and show variable AHL profiles as determined by a thin-layer chromatography/biosensor assay. All wildtype A. vitis strains revealed the presence of long-chain AHLs regardless of tumorigenicity or ability to cause the HR. Whereas genes encoding long-chain AHLs are predicted to reside on the F2/5 chromosome, the determinants for short-chain AHLs were shown to be located on conjugal plasmids.     

Erysipelothrix septicemia in a little blue penguin (Eudyptula minor).

On June 25, 2002, aquarium veterinarians treated a 5-year-old, male little blue penguin (Eudyptula minor) that was acutely recumbent and dull, with inappetence of 24-hour duration. The penguin died within 10 minutes of presentation despite emergency resuscitation efforts. Gross pathologic findings consisted of pulmonary congestion and intestinal hemorrhage. Histopathologic findings included necrosis of tips of intestinal villi, increased numbers of mononuclear cells in pulmonary interstitium and hepatic sinusoids, and gram-positive bacteria in systemic microvasculature. Transmission electron microscopic examination revealed short gram-positive bacilli located in lumina of glomerular capillaries and in cytoplasm of mononuclear phagocytic cells in the lung and liver. Erysipelothrix rhusiopathiae was recovered from the lung, liver, and intestine by bacteriologic culture. Amplicons from polymerase chain reaction (PCR) tests using Erysipelothrix genus-specific primers and total genomic DNA extracted from formalin-fixed, paraffin-embedded tissue sections of lung and intestine demonstrated 99% nucleotide sequence identity with 16S small-subunit ribosomal DNA of E. rhusiopathiae and E. tonsillarum. The source of infection was speculated to be fish in the diet; however, repeated attempts to detect Erysipelothrix spp. from the mucous layer of food fish using bacteriologic culture and PCR were unsuccessful. This is the first report of erysipelas in a captive aquatic bird. Details of the isolation of E. rhusiopathiae and the application of molecular testing to identify Erysipelothrix DNA in formalin-fixed, paraffin-embedded tissue sections are given.     

Validation of the 13C-urea breath test for use in cheetahs (Acinonyx jubatus) with Helicobacter.

Historically, therapeutic monitoring for prescribed eradication treatment of Helicobacter in cheetahs (Acinonyx jubatus) with associated gastritis has been accomplished only through endoscopic biopsies. The 13C-urea breath test (UBT) can offer an alternative to repeated biopsies for therapeutic monitoring. Five male and five female cheetahs and one male Sumatran tiger (Panthera tigris) were studied. All were clinically healthy before and after this investigation. Breath samples of end-tidal expiration were taken before and after administration of a 13C-enriched urea solution through a gastroesophageal tube. Twenty-milliliter breath samples were taken at 10, 20, 30, and 40 min after administration of the urea solution. The results of the breath analysis were compared with the results of rapid urease testing, histopathologic examination, and impression smears of gastric biopsies taken at the time of the breath test. The sensitivity and specificity for the 13C-UBT in this investigation were 100%. and the positive predictive value and negative predictive value were both 100%. Although the 13C-UBT is a good noninvasive diagnostic tool for monitoring the presence of Helicobacter sp. in the gastric mucosa, endoscopy should still be used for initial diagnosis and grading of gastritis and for monitoring the progression of disease in cheetahs. The 13C-UBT is a valuable, simple, accurate, and sensitive tool for monitoring eradication of Helicobacter during therapy for clinical gastritis.     

Second round of an interlaboratory comparison of SARS-CoV2 molecular detection assays used by 45 veterinary diagnostic laboratories in the United States

The COVID-19 pandemic presents a continued public health challenge. Veterinary diagnostic laboratories in the United States use RT-rtPCR for animal testing, and many laboratories are certified for testing human samples; hence, ensuring that laboratories have sensitive and specific SARS-CoV2 testing methods is a critical component of the pandemic response. In 2020, the FDA Veterinary Laboratory Investigation and Response Network (Vet-LIRN) led an interlaboratory comparison (ILC1) to help laboratories evaluate their existing RT-rtPCR methods for detecting SARS-CoV2. All participating laboratories were able to detect the viral RNA spiked in buffer and PrimeStore molecular transport medium (MTM). With ILC2, Vet-LIRN extended ILC1 by evaluating analytical sensitivity and specificity of the methods used by participating laboratories to detect 3 SARS-CoV2 variants (B.1; B.1.1.7 [Alpha]; B.1.351 [Beta]) at various copy levels. We analyzed 57 sets of results from 45 laboratories qualitatively and quantitatively according to the principles of ISO 16140-2:2016. More than 95% of analysts detected the SARS-CoV2 RNA in MTM at ≥500 copies for all 3 variants. In addition, for nucleocapsid markers N1 and N2, 81% and 92% of the analysts detected ≤20 copies in the assays, respectively. The analytical specificity of the evaluated methods was >99%. Participating laboratories were able to assess their current method performance, identify possible limitations, and recognize method strengths as part of a continuous learning environment to support the critical need for the reliable diagnosis of COVID-19 in potentially infected animals and humans.     

Candidate genes underlying QTL for flowering time and their interactions in a wide spring barley (Hordeum vulgare L.) cross

Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that dete...     

氯——被误解的杀菌剂

氯的使用可有效减少家禽胴体和屠宰加工厂的细菌。但是,我们有必要对氯有一个更好的认识和管理。