Aerobic microbial respiration in 86-million-year-old deep-sea red clay

Microbial communities can subsist at depth in marine sediments without fresh supply of organic matter for millions of years. At threshold sedimentation rates of 1 millimeter per 1000 years, the low rates of microbial community metabolism in the North Pacific Gyre allow sediments to remain oxygenated tens of meters below the sea floor. We found that the oxygen respiration rates dropped from 10 micromoles of O(2) liter(-1) year(-1) near the sediment-water interface to 0.001 micromoles of O(2) liter(-1) year(-1) at 30-meter depth within 86 million-year-old sediment. The cell-specific respiration rate decreased with depth but stabilized at around 10(-3) femtomoles of O(2) cell(-1) day(-1) 10 meters below the seafloor. This result indicated that the community size is controlled by the rate of carbon oxidation and thereby by the low available energy flux.     

Detection of papillomavirus-DNA in mesenchymal tumour cells and not in the hyperplastic epithelium of feline sarcoids

Abstract We examined 12 formalin-fixed paraffin-embedded feline skin tumours which had the histopathological features of fibropapillomas for the presence of papillomavirus (PV) DNA using touchdown polymerase chain recation (PCR), DNA sequencing and nonradioactive in situ hybridization. Nine of the tumours contained a 102-bp PCR product demonstrated using consensus PV primers that amplify a portion of the L1 gene. The nucleotide sequences are closely related, but not identical to that of ovine PV type 2, rabbit oral PV and reindeer PV. The deduced amino acid sequences had strong homologies with the major capsid protein L1 of deer PV, bovine papillomavirus (BPV) 1 and BPV 2, and European elk PV. Although PV antigens were not detected in any of the tumours by immunohistochemistry, PV DNA was demonstrated in individual mesenchymal cells or cell nests of 4/12 tumours by in situ hybridization. A nonproductive infection of mesenchymal fibroblast-like tumour cells with a papillomavirus would explain the lack of PV antigen expression and the absence of PV DNA in the hyperplastic epithelium. Because these tumours and their pathogenesis are similar to equine sarcoids, we suggest that they should be reclassified as 'feline sarcoids' instead of fibropapillomas.     

Epidemiological investigations of an outbreak of intestinal atresia in two Israeli dairy herds

An epidemiological investigation of an outbreak of intestinal atresia in Israeli Holstein-Friesian newborn calves showed a linkage with rectal palpation for early pregnancy diagnosis, performed less than 42 days after insemination. The odds of an exposed calf, i.e., one born to a dam that was diagnosed by early palpation as having intestinal atresia were 119.7 times higher than one born in normal control herds (95% CI; 7.4-1946.3). A total of 682 calves-at-risk was recorded from mid-1998 to mid-2000 and a total of 47 calves (6.9%) were born with intestinal atresia during this period. Two forms of intestinal atresia were recognized at post-mortem: atresia coli and atresia ilei.     

Evaluation of a single dose versus a divided dose regimen of danofloxacin in treatment of Actinobacillus pleuropneumoniae infection in pigs

A single versus a divided dose regimen of danofloxacin was evaluated in treatment of porcine Actinobacillus pleuropneumoniae infection using clinical observations combined with biochemical infection markers: C-reactive protein, zinc and ascorbic acid. Twenty hours after experimental infection, the 18 pigs received danofloxacin intravenously as a single dose of 2.5mg/kg or four doses of 0.6 mg/kg administered at 24h intervals. These dosage regimens resulted in similar AUCs of the plasma danofloxacin vs time curve. The maximum concentration was 3.5-fold higher using the single dose regimen, while the time with concentrations above the MIC was 2.5-fold longer using the fractionated regimen. Using the single dose regimen, temperature was normalised 32 h post-infection. In contrast, normalisation was delayed until 44 h post-infection using four low doses and a relapse with elevated temperatures at 52 and 68 h was observed. No other significant differences between the treatments were found, neither regarding clinical, haematological nor biochemical observations. The use of the more convenient single dose regimen was appropriate, as it was at least equivalent to the fractionated regimen.     

Risk factors associated with faecal shedding of verocytotoxin-producing Escherichia coli O157 in eight known-infected Danish dairy herds

A risk-factor study was performed in eight dairy herds found to excrete verocytotoxin-producing Escherichia coli (VTEC) O157 in a former prevalence study. Associations between excretion of VTEC O157 and management factors such as housing and feeding were analysed in a generalised linear mixed model. The animals were stratified in three age groups and sampled four times during 1 year. The risk of excreting VTEC O157 was higher among weaned calves than non-weaned calves. Among the calves aged 1–4 months, the risk was reduced if the calf had suckled colostrum from the mother or if the calf had stayed >2 days with the mother after calving. Calves aged 5–24 months that had been moved within the last 2 weeks had a higher risk, but risk was reduced if fed barley silage. Cows fed grain or molasses had a higher risk of excreting VTEC O157.     

Association with the Syndrome "Basses Richesses" of Sugar Beet of a Phytoplasma and a Bacterium-Like Organism Transmitted by a Pentastiridius sp

ABSTRACT The syndrome "basses richesses" of sugar beet (SBR) was first observed in 1991 in Burgundy, France. A cixiid planthopper, Pentastiridius beieri, has been proved to be involved in the transmission to sugar beet of a stolbur phytoplasma, which could be detected in some affected plants. In 2000, periwinkle and sugar beet exposed to field-collected cixiids developed symptoms similar to SBR on sugar beet. Use of 4'-6-diamidino-2-phenylindole (DAPI) staining and transmission electron microscopy confirmed the presence of phytoplasma in some of the plants, which were also positive for this pathogen in a polymerase chain reaction (PCR) analysis. A phloem-restricted gram-negative bacteria was seen in all other plants with symptoms but PCR-negative for phytoplasma. Three primer pairs reported as diagnostic for phloem-limited bacteria were tested but only primers specific for 'Candidatus Phlomobacter fragariae' gave a positive signal, which related to the presence of DAPI-stained bacteria-like objects in diseased plants. Although phytoplasma and bacterium-like organisms were associated with the same macroscopic symptoms on sugar beet, histochemical analysis of phloem cells showed that phytoplasma were associated with cell necrosis and cell wall lignification, while bacteria were associated with these same abnormalities as well as deposit of phenolic compounds in the lumen of phloem cells.     

Maximum-likelihood estimation of sensitivity and specificity of ELISAs and faecal culture for diagnosis of paratuberculosis

The accuracy of three diagnostic tests for paratuberculosis was evaluated using maximum-likelihood estimation of sensitivity and specificity. We also explored the variety of estimates that can be obtained if the tests are to be used in populations of different composition with regard to infection and disease states. Two enzyme-linked immunosorbent assays (ELISAs) were evaluated separately with the faecal culture (FC). The study was carried out as a cross-sectional field study to cover all likely states of infection with Mycobacterium avium subsp. paratuberculosis.The three basic assumptions for the maximum-likelihood technique were evaluated to validate the results. Our accuracy estimates for the ELISAs were not very different from those previously published, but those for faecal culture differed if a different cut-off value was chosen for the ELISA. If faecal culture was used for screening in a Danish dairy region where the median ELISA reading was a measure of the general disease situation, the sensitivity of the faecal culture was 20-25%. If faecal culture was used as a confirmatory test on cows with a high ELISA reading (and thus high level of antibodies), the sensitivity of the faecal culture would be in the range 60-70%. These results emphasise the importance of the composition of a target population before selecting a specific diagnostic test for a given purpose. We concluded that faecal culture is useful for confirmation but not for screening purposes.     

Fungal flora on cutaneous and mucosal surfaces of cats infected with feline immunodeficiency virus or feline leukemia virus

OBJECTIVE: To compare cutaneous and mucosal mycoflora in cats infected with FIV or FeLV with that in noninfected cats. ANIMALS: 85 client-owned cats; 24 seropositive for FIV, 10 seropositive for FeLV, 1 seropositive for both viruses, and 50 seronegative for both viruses. PROCEDURE: Cutaneous specimens were obtained from the coat and external acoustic meatus (ear canal) and mucosal specimens from the oropharynx and rectum. Fungi were isolated from specimens, using Sabouraud dextrose agar incubated at 27 or 37 C for cutaneous and mucosal specimens, respectively. RESULTS: Fungal colonies were cultured from at least 1 specimen from 83 of 85 (97.6%) cats. The most common fungal isolates were Aspergillus spp (cultured from 59.3% of all specimens), Penicillium spp (50.0%), Cladosporium spp (44.2%), Scopulariopsis spp (41.8%), and lipophilic yeasts of the genus Malassezia (31.4%). A greater diversity of fungal genera was isolated from retrovirus-infected cats, and Malassezia spp were more commonly recovered from these cats, compared with noninfected cats. Candida albicans, Cryptococcus neoformans, and dermatophytes (eg, Microsporum canis) were rarely isolated from any cat. Significant differences in frequency of isolation of C. neoformans and dermatophytes were not found between infected and noninfected cats. CONCLUSIONS AND CLINICAL RELEVANCE: Cats infected with FIV or FeLV may have a greater diversity of cutaneous and mucosal mycoflora than noninfected cats. However, infected cats may be no more likely than noninfected cats to expose humans to zoonotic fungi such as C. albicans, C. neoformans, and M. canis.