Survey of microhymenoptera (Hymenoptera: Chalcidoidea) parasitizing filth flies (Diptera: Muscidae, Calliphoridae) breeding in refuse and poultry farms in peninsular Malaysia

Nine species of parasitoids were found parasitizing the pupae of filth flies breeding in refuse dumps and poultry farms throughout peninsular Malaysia. Spalangia were most common, consisting of Spalangia endius Walker, S. cameroni Perkins, S. gemina Boucek, S. nigroaenea Curtis, and two undescribed species. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani, Dirhinus himalayanus Westwood, and an unidentified Hymenoptera. The parasitized fly hosts included Musca domestica L., Chrysomya megacephala (F.), Fannia sp., and Ophyra sp. S. endius was the most common parasitoid attacking M. domestica and C. megacephala at refuse dumps and poultry farms D. himalayanus were found to parasitize only M. domestica pupae collected at poultry farms.     

A myopathy associated with muscle hypertonicity in the Cavalier King Charles Spaniel

Clinical signs of electrically silent muscle hypertonicity are described in five Cavalier King Charles dogs. Biopsies of the biceps femoris and triceps muscles, when examined with the electron microscope, revealed evidence of sarcotubular and mitochondrial abnormalities. These included enlargement of the sarcoplasmic reticulum, hydropic degeneration of mitochondria, tubular proliferations in the vicinity of the triads and vacuolar invagination of mitochondria. The exact nature of these findings is not clear and it is suggested that utilization of tracer techniques would help to explain them.     

An inherited retinopathy in commercial breeding chickens

Impaired vision was observed in individual birds from several related flocks of layer breeding chickens. The condition was usually apparent by eight weeks of age. Affected birds were unable to perceive food particles on a flat surface or to negotiate a 50 mm bridge, although apparently able to discern large objects and to respond to bright light. On ophthalmoscopic examination of the fundus the choroidal vasculature was usually more readily visualised than in normal chickens and in addition discrete white streaks were often seen to extend peripherally from the base of the pecten. Cataract formation was frequently present by several months of age. The electroretinograms of two affected birds were of abnormally low amplitude. Light microscopy of the retinas of most birds exhibiting blindness showed a generalised reduction in the number of photoreceptors and in the thickness of the outer nuclear layer, although in others there were no obvious abnormalities. The linear fundus lesions represented abrupt thinnings of the retina in which, to a varying degree, the retinal pigment epithelium and photoreceptor inner and outer segment, outer nuclear and outer plexiform layers were disorganised or absent. A mating of affected individuals produced progeny of which 13/14 were obviously ' blind, indicating an hereditary basis for the condition.     

Immunopathology and cytokine responses in commercial broiler chickens with gangrenous dermatitis

Gangrenous dermatitis (GD) is an emerging disease of increasing economic importance in poultry resulting from infection by Clostridium septicum and Clostridium perfringens type A. Lack of a reproducible disease model has been a major obstacle in understanding the immunopathology of GD. To gain better understanding of host–pathogen interactions in GD infection, we evaluated various immune parameters in two groups of birds from a recent commercial outbreak of GD, the first showing typical disease signs and pathological lesions (GD-like birds) and the second lacking clinical signs (GD-free birds). Our results revealed that GD-like birds showed: reduced T-cell and B-cell mitogen-stimulated lymphoproliferation; higher levels of serum nitric oxide and α-1-acid glycoprotein; greater numbers of K55⁺, K1⁺, CD8⁺, and MHC class II⁺ intradermal lymphocytes, and increased K55⁺, K1⁺, CD8⁺, TCR1⁺, TCR2⁺, Bu1⁺, and MHC class II⁺ intestinal intraepithelial lymphocytes; and increased levels of mRNAs encoding proinflammatory cytokines and chemokines in skin compared with GD-free chickens. These results provide the first evidence of altered systemic and local (skin and intestine) immune responses in GD pathogenesis in chickens.     

Common variants of chemokine receptor gene CXCR3 and its ligands CXCL10 and CXCL11 associated with vascular permeability of dengue infection in peninsular Malaysia

Dengue causes significantly more human disease than any other arboviruses. It causes a spectrum of illness, ranging from mild self-limited fever, to severe and fatal dengue hemorrhagic fever, as evidenced by vascular leakage and multifactorial hemostatic abnormalities. There is no specific treatment available till date. Evidence shows that chemokines CXCL10, CXCL11 and their receptor CXCR3 are involved in severity of dengue, but their genetic association with the susceptibility of vascular leakage during dengue infection has not been reported. We genotyped 14 common variants of these candidate genes in 176 patients infected with dengue. rs4859584 and rs8878 (CXCL10) were significantly associated with vascular permeability of dengue infection (P < 0.05); while variants of CXCL11 showed moderate significance of association (P = 0.0527). Haplotype blocks were constructed for genes CXCL10 and CXCL11 (5 and 7 common variants respectively). Haplotype association tests performed revealed that, “CCCCA” of gene CXCL10 and “AGTTTAC” of CXCL11 were found to be significantly associated with vascular leakage (P = 0.0154 and 0.0366 respectively). In summary, our association study further strengthens the evidence of the involvement of CXCL10 and CXCL11 in the pathogenesis of dengue infection.     

Seroprevalence of Mycoplasma synoviae in Dutch commercial poultry farms

Before the year 2000, Mycoplasma synoviae was associated mainly with subclinical respiratory infections in broilers in the Netherlands and was considered to have low clinical and economic impact. The subsequent occurrence of M. synoviae arthritis and amyloid arthropathy, and of eggshell apex abnormalities, has resulted in an increasing demand for M. synoviae-free poultry. Therefore, a cross-sectional seroprevalence study was carried out over a 12-month period during 2005 and 2006. Ten blood samples per farm were generally used because M. synoviae was expected to spread quickly. However, for grandparent and layer breeder stock, 24 to 60 blood samples per house were available from a voluntary M. synoviae monitoring programme. Sera were tested by means of the rapid plate agglutination test (agglutination at dilution ≥1:8 was considered positive). The numbers of farms sampled out of the national total were: broiler grandparent, 53/53; broiler parent rearing, 34/150; broiler parent, 114/300; broiler, 185/800; layer grandparent, 13/13; layer parent, 40/50; layer, 173/1250; and meat turkey, 50/75. The seroprevalence of M. synoviae in commercial poultry was high, especially in commercial layers where it was 73% (95% confidence interval (CI)=67 to 80); in layer and broiler grandparent stock, the seroprevalence was 0% and 10%, respectively, based on sample sizes equal to the population size. In layer and broiler parent farms, the seroprevalence was 25% (95% CI=19 to 31) and 35% (95% CI=28 to 44); in both broiler parent rearing and broiler farms it was 6% (95% CI=0 to 13 and 95% CI=3 to 9); and in meat turkey, the seroprevalence was 16% (95% CI=10 to 22).     

Staphylococcus simulans associated with endocarditis in broiler chickens

This report suggests a strong association between coagulase-negative Staphylococcus simulans and endocarditis in broiler chickens of a single flock. Clinical signs included increased mortality and lameness, and some dead chickens were found on their backs. Lesions included cauliflower-like, fibrinous vegetative lesions on the left atrioventricular valve; cream-coloured, necrotic foci of varying size in the liver; and necrosis of the femoral head. Histopathological examination of the heart revealed multifocal conglomerates of bacterial colonies attached to the valvular endocardium, threads of fibrin, and inflammatory cells with the presence of heterophils. S. simulans strains were first identified by API ID32, and then confirmed with Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and by partial sequencing of the rpoB and dnaJ genes. These bacteria were resistant to methicillin but sensitive to vancomycin and characterized by slime production and protease activity.     

An outbreak of gangrenous dermatitis in commercial broiler chickens

The present report describes an outbreak of gangrenous dermatitis (GD) infection in a commercial poultry farm in Delaware involving 34-day-old broiler chickens. In addition to obvious clinical signs, some GD-affected broilers also showed severe fibrino-necrotic enteritis and large numbers of Gram-positive rods in the necrotic tissue. Histopathological findings included haemorrhage, degeneration and necrosis of parenchymatous cells, especially of skin, muscle, and intestine. Immunofluorescence staining revealed Clostridium-like bacilli in the skin and the intestine. Both Clostridium perfringens and Clostridium septicum genomic sequences were identified by polymerase chain reaction in bacterial cultures isolated from the skin, muscle, and intestine, and in the frozen tissues from the GD-affected birds. Serological analysis demonstrated that both affected and clinically healthy birds from the same house had high serum antibody titres against C. perfringens, C. septicum, Eimeria, chick anaemia virus, and infectious bursal disease virus. These results are discussed in the context of the relationship between the different Clostridium spp. and the pathogenesis of GD.     

A recombinant avian leukosis virus associated with fowl glioma in layer chickens in Japan

Fowl glioma is characterized by multiple nodular growth of astrocytes, and fowl glioma-inducing virus belonging to avian leukosis virus has been isolated from Japanese bantam as a causal agent. Subcutaneous neoplasms of the head and neck have been reported in layer chickens since 2003 in Japan, and fowl glioma concurred in these affected layers. In the present study, the histopathology of 240 layers, including 18 layers with subcutaneous neoplasms and 222 layers kept with the affected layers, was performed to clarify the characteristics of fowl glioma in layers. Microscopically, 103 layers showed non-suppurative encephalitis, and four layers had locally extensive proliferation or multiple nodules of astrocytes. Gliomas concurred in 11 layers with subcutaneous neoplasms and occurred independently in three layers. In addition, two layers had locally extensive proliferation of small, round cells in the cerebrum. The fowl glioma-inducing virus genome was not detected in the affected brains by nested polymerase chain reaction. Ten isolates were obtained from the affected brains. By nucleotide sequencing of the env gene, SU coding regions of these isolates were most closely related to myeloblastosis-associated virus-like viruses, but TM regions showed the highest similarity to endogenous viral (ev) loci. The genome of one isolate mainly consisted of ev loci and contained several parts of other avian leukosis/sarcoma viruses. These results show that the causal avian leukosis virus of fowl glioma is not just fowl glioma-inducing virus and that different avian leukosis virus strains having oncogenicity in the central nervous system by recombination are spread in layers in Japan.     

Staphylococcus hyicus associated with pox in chickens and in turkeys

Staphylococcus hyicus was isolated in profuse and often pure culture from skin lesions, and from internal organs of chickens and turkeys suffering from pox. Most cases were seen in backyard stock, but similar observations were made in laying hens from an industrial farm.     

Myelosclerosis associated with systemic lupus erythematosus in patients in West Malaysia

Three cases of myelosclerosis associated with systemic lupus erythematosus are described. The probable role of systemic lupus erythematosus in the initiation of myelonecrosis and subsequent myelosclerosis is discussed.     

Microbial populations associated with commercial bread production

The microbial ecology of a commercial bread production line was assessed by plate counts and characterization of microbial populations of raw materials, dough, equipment surfaces, air inside the bakery and baked bread. Aerobic plate counts for raw materials were higher than mould counts. Dough samples had high aerobic plate counts, but low mould counts. Mould counts on pre-baking equipment surfaces were lower than those on post-baking equipment surfaces, while aerobic plate counts on equipment surfaces varied. Counts of bacteria and moulds on bread increased during storage at 30 °C and moulds predominated over bacteria on air settle plates. Of the 316 bacterial isolates, 50% were Bacillus and 31.6% Micrococcus. Of the 97 mould isolates, 37.1% were Penicillium, 18.6% Aspergillus and 13.4% Cladosporium. Bacillus, Aspergillus and Penicillium were isolated predominantly from baked bread.     

Mitochondrial myopathy associated with a novel 5522G>A mutation in the mitochondrial tRNATrp gene

We report a novel pathogenic mutation of the mitochondrial transfer RNA (tRNA) gene for tryptophan in a patient with isolated myopathy and persistently elevated creatine kinase. Muscle studies revealed ragged red fibres and decreased activity of respiratory chain complex I and cytochrome c oxidase (COX). Sequencing of the 22 mitochondrial tRNA genes revealed a mutation m.5522G>A, which alters a conserved base pairing in the D-stem of the tRNA for tryptophan. The mutation was heteroplasmic with a mutational load between 88 and 99% in COX-negative fibres. This case contributes to the genetic heterogeneity of mitochondrial diseases caused by mutations in mitochondrial tRNA genes.     

Pathogenic mitochondrial mt-tRNAAla variants are uniquely associated with isolated myopathy

Pathogenic mitochondrial DNA (mtDNA) point mutations are associated with a wide range of clinical phenotypes, often involving multiple organ systems. We report two patients with isolated myopathy owing to novel mt-tRNA^Ala variants. Muscle biopsy revealed extensive histopathological findings including cytochrome c oxidase (COX)-deficient fibres. Pyrosequencing confirmed mtDNA heteroplasmy for both mutations (m.5631G>A and m.5610G>A) whilst single-muscle fibre segregation studies (revealing statistically significant higher mutation loads in COX-deficient fibres than in COX-positive fibres), hierarchical mutation segregation within patient tissues and decreased steady-state mt-tRNA^Ala levels all provide compelling evidence of pathogenicity. Interestingly, both patients showed very high-mutation levels in all tissues, inferring that the threshold for impairment of oxidative phosphorylation, as evidenced by COX deficiency, appears to be extremely high for these mt-tRNA^Ala variants. Previously described mt-tRNA^Ala mutations are also associated with a pure myopathic phenotype and demonstrate very high mtDNA heteroplasmy thresholds, inferring at least some genotype:phenotype correlation for mutations within this particular mt-tRNA gene.     

An entero-like virus associated with the runting syndrome in broiler chickens

A small round unenveloped virus, 31 nm in diameter, and with no obvious surface structure, was identified during the first week of life in the gut contents of broiler chickens which later developed runting. This virus grew in the cytoplasm of the villous epithelial cells of the small intestine, with a predilection for the mid small intestine. Broilers orally infected at 1 day old with a crude inoculum containing the small round virus and reovirus passed abnormal faeces, gained weight and feathered more slowly than controls, which were either uninoculated or inoculated with faeces from SPF chicks. The small round virus was passaged four times through broilers using gut contents collected from experimentally infected birds between 2 and 3 days after inoculation. Clinical signs as described above were obtained at each passage. The small round virus could not be grown serially in cell cultures. However, immunofluorescence showed that viral antigen was synthesised in the cytoplasm of infected chicken embryo liver and chick kidney cell cultures. The small round virus was resistant to pH3. It is suggested that the small round virus is an enterovirus but no evidence for an antigenic relationship with avian encephalomyelitis virus was obtained.