Variation in growth rates and aggressiveness of naturally occurring self‐fertile and self‐sterile isolates of the wilt pathogen Ceratocystis albifundus

Ceratocystis albifundus is the most important fungal pathogen of black wattle (Acacia mearnsii) grown in plantations in southern and eastern Africa. It is a homothallic fungus but also undergoes unidirectional mating type switching. As a result, the ascospore progeny can be either self‐fertile or self‐sterile. The only apparent difference between these mating types is the deletion of the MAT1‐2‐1 gene in self‐sterile isolates. There is some evidence suggesting that self‐sterile isolates grow more slowly than self‐fertile isolates, but this has not been tested rigorously. The aim of this study was to determine whether self‐sterile isolates are less fit by examining growth rate, relative germination rate and pathogenicity. Five self‐sterile isolates were generated from each of five self‐fertile isolates of C. albifundus and these 30 isolates were compared. The results showed that the self‐sterile isolates grew consistently slower and were less pathogenic than the self‐fertile isolates. The germination ratio of self‐fertile to self‐sterile isolates from single ascospores collected from the ascomata of five self‐fertile isolates was on average 7:3. This could be a consequence of the self‐sterile isolates having a lower germination rate. This observation, and the lower growth and pathogenicity levels, suggests that self‐sterile isolates are not likely to compete effectively in nature, raising intriguing questions regarding their role and value to C. albifundus and other fungi having a similar mating system.     

Enteropathogenicity of Plesiomonas shigelloides and Aeromonas spp. in experimental mono- and coinfection with Cryptosporidium parvum in the intestine of neonatal BALB/c mice

Enteropathogenicity of Plesiomonas shigelloides, Aeromonas hydrophila, A. caviae and A. sobria was studied both in monoinfections and in coinfections with coccidium Cryptosporidium parvum in neonatal BALB/c mice. In monoinfection experiments, neonatal BALB/c mice were orally infected with 7 x 10(7) or 7 x 10(8) CFU, respectively, of a strain of P. shigelloides or a strain of an Aeromonas spp. In coinfection experiments, the neonatal mice were, in addition to being orally infected with one of the four bacterial species, orally infected with an inoculum containing 10(5) oocysts of C. parvum. Results from monoinfections with P. shigelloides revealed long-term colonisation of the neonatal mouse intestine by this pathogen, along with associated pathological lesions. The lesions varied in severity from atrophy to necrosis of the mucosal inner surface of the ileum and colon, with predilection to the colon and brush border of colonic enterocytes. The effects of coinfection of P. shigelloides with C. parvum were characterised by bacteremia and heavy colonisation of the intestine by P. shigelloides. In addition, extensive necrotising inflammatory changes in the ileum and colon were accompanied by diarrhoea and deaths of coinfected mice. In contrast, the results from monoinfections of neonatal mice with Aeromonas spp. showed only a short-term colonisation of the intestine by the pathogen. However, when mice were coinfected with A. hydrophila and C. parvum, then the growth of the bacterial species was prolonged, and occurred in both the spleen and intestine. However, no substantial clinical or histopathological changes were observed in mice, whether monoinfected with Aeromonas spp. or coinfected with C. parvum. Our study suggests that experimental monoinfections of neonatal BALB/c mice with P. shigellodes, Aeromonas spp. and C. parvum, together with coinfections (each bacterial species with the protozoan C. parvum), may serve as a useful model to study the initial steps of gastrointestinal colonisation and diarrhoeal disease syndromes caused by enteropathogenic bacteria and protozoa, individually and in combination.     

Performance dependent lysine requirement of fattening pigs. 3. Effect of amino acid and energy intake on fat, protein and lysine deposition of swine

The gain in structural matter had a linear course with a corresponding feeding intensity and depending on the period of fattening. However, the animals given high-energy diets deposited 130 g protein per day during the first fattening period, this deposition being compensated in the course of further growth by a considerably lower deposition in the sense of aequifinality. Up to a live weight of 70 kg, animals subjected first to restricted feeding and then to fully balanced feeding revealed the highest protein deposition during the last period of fattening, this fact emphasizing the leanmeat character of the animal material used. The daily fat deposition was found clearly determined by energy intake and independent of amino acid supply. Lysine conversion was influenced by the intake of lysine and energy. Under feeding to norm it reached some 40 and 30% during the first and second periods of fattening, respectively.     

High prevalence and antimicrobial resistance of mecA Staphylococcus aureus in dairy cattle,sheep, and goat bulk tank milk in Jordan

Tropical Animal Health and Production - The aim of this study was to determine the prevalence and antimicrobial resistance of mecA and mecC methicillin-resistant Staphylococcus aureus (MRSA) in...     

Two-dimensional,long-axis echocardiographic ratios for assessment of left atrial and ventricular size in dogs

Introduction

Left ventricular (LV) and left atrial (LA) enlargement affect management and outcome of dogs with cardiac disease. Short-axis, two-dimensional echocardiographic (2DE) images, indexed to the aorta (Ao), are frequently used to identify cardiomegaly. Long-axis images offer complementary views of the left heart.

Alfalfa metabolism of propham

Root-treated alfalfa absorbs, translocates, and metabolizes [phenyl-¹⁴C]isopropyl carbanilate ([¹⁴C]propham). After 7 days of root treatment, the distribution of radiolabel was 73% for shoots and 27% for roots. Shoots and roots were extracted and separated into the polar, nonpolar, and solid residual components using a mixture of chloroform, methanol and water. The insoluble residues accounted for approximately 40% of the ¹⁴C found in shoots and roots. The nonpolar fraction (6.1% of the radiolabel in shoots and roots) was not characterized, but was shown to be some component other than parent propham. Propham was not found in either shoots or roots. The polar metabolites were partly purified on Amberlite XAD-2. Cellulase-liberated aglycones were derivatized and separated by high-performance liquid and gas-liquid chromatography. The infrared, nuclear magnetic resonance, and mass spectral data showed that the polar metabolites of alfalfa shoots and roots were glycoside conjugates of isopropyl 2-hydroxycarbanilate (2-hydroxypropham) and isopropyl 4-hydroxycarbanilate (4-hydroxypropham). Conjugated 4-hydroxypropham accounted for 45.9% of the ¹⁴C in the shoots and 3.4% of the ¹⁴C in the roots. Conjugated 2-hydroxypropham accounted for 3.4% of the ¹⁴C in the shoots and 1.4% of the ¹⁴C in the roots.     

Hemostatic changes in dogs with naturally occurring sepsis

Sepsis is a frequent source of morbidity and mortality in critically ill patients. The goal of this case control study was to measure hemostatic changes in dogs with naturally occurring sepsis. Blood was collected within 24 hours of admission from 20 dogs that fulfilled the criteria for sepsis. Sepsis was defined as histologic or microbiological confirmation of infection and 2 or more of the following criteria: hypo- or hyperthermia, tachycardia, tachypnea, or leukopenia, leukocytosis, or > 3% bands. Culture and sensitivities were performed on appropriate samples from all septic dogs. Twenty-eight control dogs were enrolled on the basis of normal results of physical examination, CBC, serum biochemistry, and coagulation profile. Plasma samples were analyzed for prothrombin time (PT), partial thromboplastin time (PTT), fibrin(ogen) degradation products (FDP), D-dimer (DD) concentrations, antithrombin (AT) activity, and protein C (PC) activity. Data were compared between groups by chi-square or independent t-tests. PC (P < .001) and AT (P < .001) activities were significantly lower in dogs with sepsis compared to controls. Dogs with sepsis had significantly higher PT (P = .007), PTT (P = .005), D-dimer (P = .005), and FDP (P = .001) compared to controls. Platelet counts were not significantly different between groups. Ten of the 20 septic dogs (50%) died, but no association was identified between any of the measured variables and outcome. These findings are consistent with previous studies in animals with experimentally induced disease and in clinical studies of humans. On the basis of these results, further investigation of the role of AT and PC in canine sepsis is warranted.     

Measurement of glycosaminoglycans and keratan sulphate in canine arthropathies

Glycosaminoglycans (gag) and keratan sulphate (ks) were measured in sera and synovial fluids from dogs with either osteoarthritis (oa) or rupture of the cranial cruciate ligament (ccl) and normal dogs. The dogs with oa had higher synovial fluid gag levels (P<0·002) and serum KS (P<0·03) compared to the normal dogs. No significant differences in serum gag were found in either group. In both oa and rupture of the ccl, gag levels were increased in the synovial fluid from the affected joint compared with the clinically normal (inactive) contralateral joint. Neither gag nor ks measurements correlated with serum and synovial fluid antibodies to collagen type II, synovial fluid white cell count or age of dog. It is unlikely that the measurement of these cartilage breakdown products is of value for diagnostic or prognostic use in canine arthropathies.