Clostridium piliforme infection (Tyzzer disease) in horses: retrospective study of 25 cases and literature review

Tyzzer disease (TD) is caused by Clostridium piliforme, a gram-negative and obligate intracellular bacterium. The disease occurs in multiple species. A triad of lesions, namely colitis, hepatitis, and myocarditis, is described in cases of TD in some species, such as rats and mice. We carried out a retrospective analysis of 25 equine cases with a diagnosis of TD; 24 of 25 cases occurred in foals <45 d old; the remaining foal was 90 d old. There were 12 males and 12 females; no sex information was available for one foal. The affected breeds were Quarter Horse, Thoroughbred, Arabian, Paint, and Hanoverian. Most of the cases (19 of 25) occurred in the spring. There were 9 cases of sudden death; the remaining animals had diarrhea, fever, distended abdomen, depression, weakness, non-responsiveness, and/or recumbency. Gross findings included icterus, hepatomegaly with acinar pattern, serosal hemorrhages, pulmonary edema, and/or fluid content in small and large intestine. Microscopically, all foals had severe, multifocal, necrotizing hepatitis. Necrotizing lymphohistiocytic colitis was observed in 10 of 25 foals, and multifocal necrotizing myocarditis was found in 8 of 25. Gram-negative, Steiner-positive, intracytoplasmic filamentous bacteria were observed in hepatocytes, enterocytes, and myocardiocytes, respectively. PCR detected C. piliforme DNA in the liver (24 of 24), colon (20 of 24), and heart (5 of 25). Our results indicate that necrotic hepatitis is the hallmark of TD in horses; the so-called triad of lesions is not a consistent characteristic of the disease in this species.     

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Hydraulic Retention Time Influence on Improving Flocculation in the Activated Sludge Processes Through Polyelectrolytes

Hydraulic retention time (HRT) influence improving sludge flocculation with adding the polyelectrolytes (non-ionic, anionic, and cationic) was studied on an activated sludge (AS) system fed with synthetic domestic wastewater (SDW), dairy industry wastewater (DIW), and caramel industry wastewater (CIW). The sludge volumetric index, food/microorganism ratio (F/M), and mixed liquor volatile suspended solids at different HRTs (6, 8 and 10 h) were monitored on an experimental model. Results showed that both SDW and IW had the best sludge flocculation conditions at 8 h and 100 mL of non-ionic polyelectrolyte (0.2 mg L^?1). In addition, this phenomenon reached the organic matter removal efficiencies of 95.9, 95.7, and 94.2% for SDW, DIW, and CIW, respectively. Therefore, optimum HRT increased the organic matter removal efficiencies by 10%, sludge concentration by 37% (22–55%), and F/M ratio by 70%. Moreover, the polyelectrolytes used in AS improved the sludge flocculation by 2.9 times.     

Comparison of larval thermal maxima between <Emphasis Type="Italic">Fundulus heteroclitus</Emphasis> and <Emphasis Type="Italic">F. grandis</Emphasis>

Fundulus heteroclitus and F. grandis are resident salt marsh fishes that overlap in distribution over a narrow range in northeastern Florida. The objective of the present study was to examine whether the limits of the species’ ranges could be explained by differences in thermal tolerance. Two populations of each species were collected and then spawned in the laboratory, and 9-day-old larvae were used for critical thermal maxima trials. Mean LOE temperatures of larvae ranged from 43.04 to 43.65°C and showed little difference between species. Therefore, differences in high temperatures experienced cannot account for the differences of the distributions of the two species. Condition-specific competition may play a greater role in determining the observed range of the two species.     

Cryptic occurrence of <Emphasis Type="Italic">Chattonella marina</Emphasis> var. <Emphasis Type="Italic">marina</Emphasis> in mangrove sediments in Probolinggo,East Java Province,Indonesia

Mangrove forests and adjacent creeks are known to be highly productive estuaries, which are partly supported by benthic microalgae that grow on the sediments. During surveys investigating the microalgal floras of mangrove swamps in the eastern part of Java Island, a mud sample unexpectedly included large numbers of a notorious fish killer, Chattonella-like motile cells, and its resting cysts. These motile cells were established as clonal cultures for further identification and physiological tests. The cysts were examined through palynological and molecular biological means. Identification based on light microscopy and ribosomal RNA gene sequences confirmed that these cells and cysts were Chattonella marina var. marina. While the strains were genetically identical to the temperate strains isolated from Japan and China, temperature experiments showed that the Indonesian strains possessed a high maximum quantum yield of photosystem II even after exposure to 34 °C, a temperature at which the Japanese strain could not survive. Salinity experiments showed adaptation of the strains to a salinity of 15. These findings, together with the discovery of populations of cysts in the mangrove sediment, highlight the tough and unique nature of the Indonesian strains, which are likely adapted to wide fluctuations of temperature and salinity in mangrove swamps, and pose a potential risk to fisheries in Indonesia.     

Chromosomes of salmon (Salmo salar) by leukocyte culture

Chromosome preparations from salmon (Salmo salar) were obtained by means of leukocyte culture. The chromosome number varied from 55 to 60 with a clear maximum of 2n = 58. The chromosomes are tentatively grouped as follows: group A, two large submetacentrics; group B, 14 metacentrics; group C, two large telocentrics; group D, 22 medium telocentrics; group E, 18 small telocentrics.     

Prevalence of Haemophilus parasuis serovars isolated in Spain from 1993 to 1997

From 1993 to 1997, 327 strains of Haemophilus parasuis were isolated from spanish swine in our Diagnostic Laboratory and 174 strains (53.2%) were serotyped. Four serotypes, sv. 5 (18.4%), sv 4 (16%), sv. 2 (9.2%) and sv. 13 (8%) were the most frequently isolated and 29.3% of the studied strains were classified as non typable. The results obtained indicate that the distribution of the serotypes in Spain is very similar to that found by other researchers in Germany, Australia, Canada and alike to that found in the United States.     

Dual-label time-resolved fluoroimmunoassay for simultaneous quantification of haptoglobin and C-reactive protein in meat juice from pigs

A new method was developed to simultaneously measure 2 acute-phase proteins (APPs) by time-resolved immunofluorometry. The assay, based on double-label quantification of haptoglobin (Hp) and C-reactive protein (CRP) in meat juice samples from pigs, was constructed by use of a combination of europium and samarium chelate lanthanides as labels. Meat juice samples from 154 pigs were used for analytic and clinical validation of the assay through determination of precision, accuracy, limit of detection, and quantification. The analytic performance of the assay was satisfactory, with good intra-assay and interassay precision and accuracy. The levels of Hp and CRP were increased in the meat juice samples of diseased animals compared with healthy ones. According to the results, higher sensitivity could be achieved if the cut-off values of both proteins were taken into account for clinical relevance rather than used individually. Since the dual assay saved both time and sample, it could be used as a rapid and sensitive screening test in porcine production.