Blue EaLAMP—a specific and sensitive method for visual detection of genomic Erwinia amylovora DNA

Fire blight caused by the gram-negative bacterium Erwinia amylovora is a major disease of pome fruit like apple (Malus domestica) or pear (Pyrus communis). Detection of the pathogen is hampered by low titres usually being present during initial flower infection and the brief time frame for analysis to decide upon subsequent countermeasures. Here we describe a loop-mediated isothermal amplification of DNA (LAMP) assay for genomic DNA of Erwinia amylovora, which relies on a highly specific primer design that excludes amplification from typical DNA sources of the orchard biological system and from sample handling. The assay enables the fast detection of down to approximately 20?cfu of pure Erwinia amylovora or 100?fg genomic DNA (corresponding to approximately 25 E. amyolovora equivalents) per reaction within 45?min. Fast and reliable detection of E. amylovora in orchard samples by naked eye is achieved through a visual colour change indication with hydroxynaphthol blue. The assay avoids use of complex technical devices and is thus suitable for field testing.     

Carbon isotope constraints on the deglacial CO₂ rise from ice cores

The stable carbon isotope ratio of atmospheric CO(2) (δ(13)C(atm)) is a key parameter in deciphering past carbon cycle changes. Here we present δ(13)C(atm) data for the past 24,000 years derived from three independent records from two Antarctic ice cores. We conclude that a pronounced 0.3 per mil decrease in δ(13)C(atm) during the early deglaciation can be best explained by upwelling of old, carbon-enriched waters in the Southern Ocean. Later in the deglaciation, regrowth of the terrestrial biosphere, changes in sea surface temperature, and ocean circulation governed the δ(13)C(atm) evolution. During the Last Glacial Maximum, δ(13)C(atm) and atmospheric CO(2) concentration were essentially constant, which suggests that the carbon cycle was in dynamic equilibrium and that the net transfer of carbon to the deep ocean had occurred before then.     

Sulfate burial constraints on the Phanerozoic sulfur cycle

The sulfur cycle influences the respiration of sedimentary organic matter, the oxidation state of the atmosphere and oceans, and the composition of seawater. However, the factors governing the major sulfur fluxes between seawater and sedimentary reservoirs remain incompletely understood. Using macrostratigraphic data, we quantified sulfate evaporite burial fluxes through Phanerozoic time. Approximately half of the modern riverine sulfate flux comes from weathering of recently deposited evaporites. Rates of sulfate burial are unsteady and linked to changes in the area of marine environments suitable for evaporite formation and preservation. By contrast, rates of pyrite burial and weathering are higher, less variable, and largely balanced, highlighting a greater role of the sulfur cycle in regulating atmospheric oxygen.     

Pericardial effusion in a cat with feline infectious peritonitis

This case report describes the disease progression of a male cat with pericardial effusion. Clinical signs (dyspnea, lethargy, and weakness) started very acutely. The initial laboratory profile showed only an increase in alanine aminotransferase enzyme activity. Diagnostic imaging revealed pericardial effusion. Effusion analysis showed a Rivalta-positive, modified transudate. Detection of feline coronavirus antigen in macrophages was negative. General condition and laboratory parameters dramatically worsened within seven days. Therefore, the owners decided to euthanize the cat. Even if effusion variables are macroscopically and microscopically suspicious for FIP, a definitive diagnosis of FIP could only be made by histology (including immunhistochemical staining).     

Myocardial damage and paroxysmal ventricular tachycardia in a dog after Albuterol intoxication

Intoxication with the beta2-agonist Albuterol may lead to immediate signs of beta-adrenergic stimulation like excitation, tachypnea and tachycardia. Furthermore, it typically causes severe hypokalemia, which then leads to muscle weakness and which predisposes to ventricular arrhythmias. We describe a dog where albuterol intoxication caused runs of fast paroxysmal ventricular tachycardia that persisted after normalization of the hypokalemia. Based on a markedly elevated serum troponin I level acute myocardial damage was identified as cause of the tachyarrhythmia. Repeated Troponin I measurements and Holter-ECGs were the means to document complete cure.     

Conjunctivitis and ulcerative keratitis secondary to conjunctival plant foreign bodies in a herd of alpacas (Lama Pacos)

Purpose To describe six cases of conjunctivitis and ulcerative keratitis secondary to plant foreign bodies from weed‐contaminated grass hay which were lodged within the temporal conjunctival fornix in a herd of alpacas. Methods A total of 21 alpacas from the same farm developed blepharospasm and mucopurulent ocular discharge. Six of the 21 were evaluated at the University of Tennessee College of Veterinary Medicine within a 2‐week period. The six animals evaluated received an ophthalmic examination including slit‐lamp biomicroscopy, fluorescein staining, and topical corneal anesthesia for foreign body removal when necessary. Results Six animals had conjunctivitis characterized by hyperemia and mucopurulent discharge. Five animals had superficial ulcerative keratitis with intense corneal neovascularization and edema. In all cases, the keratitis was located at the temporal limbus. Seven plant foreign bodies were observed and were removed following topical corneal anesthesia in five animals. The plant seeds were identified as three common weed species found in orchard grass hay. Complete resolution of all clinical signs was achieved with foreign body removal and medical therapy. Conclusions Fan‐shaped temporal corneal ulcers may signify the presence of conjunctival foreign bodies in alpacas. Plant foreign bodies should be considered in addition to ocular infection when multiple animals of a herd are affected as outbreaks may occur with weed‐contaminated hay.     

Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element

Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa.