Mycobacterium microti infection in the cat: a case report, literature review and recent clinical experience

OVERVIEW: Mycobacterium microti infection is infrequently described in cats in the veterinary literature. It can be one of a large number of possible differential diagnoses in a feline patient with dermal nodules and non-healing draining ulcers, and can occasionally spread to involve the lungs and/or other areas of the body. CASE SUMMARY: This report describes the clinical signs, eventual diagnosis and variable response to treatment in a cat in Switzerland with recurrent cutaneous M microti infection. Only after several diagnostic and therapeutic attempts, over more than 2 years, was the species of Mycobacterium finally identified and targeted therapy given. PRACTICAL RELEVANCE: For any cat in which there is even a low suspicion of mycobacterial infection, the authors recommend that an aggressive diagnostic approach is taken. Tissue specimens should be collected and frozen early on, and, as soon as acid-fast bacilli are detected, samples should be sent to a mycobacterial reference laboratory for definitive identification. LITERATURE REVIEW: A review of the literature relating to the aetiopathogenesis, diagnosis and management of M microti infection in cats and dogs is included. This is supplemented with clinical and therapeutic experience gained from this case and other, unpublished cases managed over the past 15 years by one of the authors (DGM).     

Prevalence of Bartonella species, haemoplasmas and Toxoplasma gondii in cats in Scotland

The objective of this study was to determine the prevalence rates for select infectious agents of cats presented to the Royal (Dick) School of Veterinary Studies at the University of Edinburgh, Scotland. Whole blood, serum, and oral mucosal and nail bed swabs were collected. While Ehrlichia species, Anaplasma species or Rickettsia felis DNA were not amplified from any cat, 44.2% of the cats had evidence of infection or exposure to either a Bartonella species (15.3% were seropositive and 5.8% polymerase chain reaction (PCR) positive), a haemoplasma (28.6% PCR positive), and/or Toxoplasma gondii (19.2% seropositive). No Bartonella species DNA was amplified from the nail or oral mucosal swabs despite a 5.8% amplification rate from the blood samples. This finding likely reflects the absence of Ctenocephalides felis infection from our study population, as this organism is a key component for Bartonella species translocation in cats. The results from this study support the use of flea control products to lessen exposure of cats (and people) to Bartonella species and support discouraging the feeding of raw meat to cats and preventing them from hunting to lessen T gondii infection.     

Spatial characterization of acidification related parameters in sensitive regions of Atlantic Canada

Many lakes in eastern Canada are sensitive to long range transport of atmospheric pollutants because of their low buffering capacity. Thus, it is important to assess long term changes in water quality. Due to the large number of lakes, a method was needed for choosing a subset of lakes to monitor regularly. Preliminary surveys were conducted in Nova Scotia and Newfoundland in which water quality parameters connected with acidification were measured in a set of lakes in each region. This paper describes the division of each set of lakes into several groups, with lakes in a group having similar water quality parameter values, by means of cluster analysis and principal component ordination. The characteristics of the groups are shown by graphical procedures and summary statistics, and this characterization is used to both determine the number of groups and describe the final choice. The membership of the groups was subsequently assessed in terms of the influences of terrestrial weathering, marine aerosols, anthropogenically derived mineral acids and natural organic acids.     

Comparison of the chemical composition of extracts from Scutellaria lateriflora using accelerated solvent extraction and supercritical fluid extraction versus standard hot water or 70% ethanol extraction

The aqueous extract of American skullcap (Scutellaria lateriflora L. (S. lateriflora), Lamiaceae) has been traditionally used by North American Indians as a nerve tonic and for its sedative and diuretic properties. Recent reports stated that flavonoids and possibly amino acids are responsible for the anxiolytic activity. As a part of our search for environmentally friendly solvents to extract the active components from medicinal plants, we used S. lateriflora in a comparison of accelerated solvent extraction (ASE) using water, and supercritical fluid extraction (SFE) using CO2 and 10% EtOH as modifier, at different temperatures. Flavonoids and amino acids were quantified by HPLC-UV and HPLC-MS, respectively. The flavonoid content was compared with conventional extraction methods (hot water extraction and 70% ethanol). The use of ASE at 85 degrees C with water as solvent gave the best results for flavonoid glycosides and amino acids, whereas SFE gave higher yields of flavonoid aglycones. However, the results obtained for total flavonoids were not significatively superior to hot water extraction or 70% aqueous EtOH extract.     

Elucidation of protein-lipid interactions in a lysozyme-corn oil system by Fourier transform Raman spectroscopy

Lysozyme (25% in D2O, corn oil, and their emulsions (10% w/w oil/D2O solution) were examined by Fourier transform Raman spectroscopy. Emulsions showed three layers, namely, top oil, middle cream, and bottom aqueous layers. Raman spectral analysis revealed hydrophobic interactions involving both protein and lipid components. Compared to lysozyme in D2O, the difference spectrum obtained after subtraction of oil from the cream layer spectrum showed reduced intensity of tryptophan bands at 760, 1013, 1340, and 1360 cm(-)(1), reduced intensity ratio of the tyrosine doublet at 850 and 830 cm(-)(1), and increased intensity of the C-H bending band at 1455 cm(-)(1). Compared to corn oil, the difference spectrum after subtraction of lysozyme from the cream layer spectrum indicated decreased intensity at 2855 cm(-)(1) (lipid CH(2) symmetric stretch) and 3011 cm(-)(1) (unsaturated fatty acid hydrocarbon chain =C-H stretch) and a higher intensity ratio of the C-H stretching band at 2900 cm(-)(1) to bands at 2885 and 2933 cm(-)(1). Spectra of the top and bottom layers resembled corn oil and lysozyme, respectively, except for changes in the D2O band. Raman spectroscopy can be used to detect structural changes in proteins, lipids, and D2O due to protein-lipid interactions.     

Molecular modeling of syringyl and p-hydroxyphenyl beta-O-4 dimers. Comparative study of the computed and experimental conformational properties of lignin beta-O-4 model compounds

As a new approach for the study of the ultrastructure of lignin, the conformational preferences of lignin beta-O-4 model compounds have been investigated by molecular modeling. The computed results have been compared with the experimental data (X-ray crystal structures and (3)J(H)(alpha)(H)(beta) NMR coupling constant values) reported in the literature. This comparison has led to an improved understanding of the influence of the structure, stereochemistry, and intramolecular H-bonding upon the conformational properties of the beta-O-4 dimers. A large number of low-energy conformations have been predicted for the structures. It has also appeared that the conformational features are predominantly governed by local steric interactions rather than by differences in the H-bonding interactions. The threo and erythro forms differ significantly in their conformational features, with a preferential extended overall shape for the threo form in which the bulky aromatic groups are distant from each other.     

The Effect of Temperature on First Feeding, Growth, and Survival of Larval Witch Flounder Glyptocephalus cynoglossus

Witch flounder Glyptocephalus cynoglossus has recently been identified as a candidate species for aquaculture in the northeastern United States and the Canadian Atlantic Provinces. This study investigated the optimal temperatures for witch flounder larval first feeding and for long term larval culture from hatching through metamorphosis. Maximum first feeding occurred between 15.0 and 16.2 C. Larvae did not survive beyond first feeding when reared at mean temperatures of 5.1, 10.4, or 19.5 C and were unable to initiate feeding at mean rearing temperatures below 6.0 C. At a rearing temperature of 15.0 C in 16-L tanks, mean larval survival to 60 days post hatch (dph) was 14.1%. Mean overall length-specific growth rate for larvae reared to 60 dph at 15.0 C was 3.5%/d and mean absolute growth was 0.62 mm/d. Subsequent larval growth at 15.6 C began to taper off towards 70 dph at the onset of weaning which overlapped with larval metamorphosis. Growth plateaued at 85 dph, followed by a rebound between 90 and 95 dph. Survival was 100% when weaning onto a dry, pelleted diet was initiated at 70 dph with a 10-d live diet co-feeding period. These results are favorable and encourage the further pursuit of commercial witch flounder culture.     

Parasitism and host–plant relationships in the dipterous stem borer complex of ryegrass

Samples taken from a ryegrass variety trial at the Grassland Research Institute, Hurley, and examined at the Welsh Plant Breeding Station, showed that the dominant stem borer species in the overwintering generation were Geomyza tripunctata Fall. and Oscinella frit L. The rate of parasitisation of stem borers, largely by species of Hymenoptera, ranged from 15 to 43%. There were differences in host plant selection by Geomyza compared with Oscinella spp. The numbers of both stem borer groups were significantly associated with the total number of tillers per sample; however, this relationship was found to differ markedly between varieties.