Characteristics of burnt meat in cultured yellowtail <Emphasis Type="Italic">Seriola quinqueradiata</Emphasis>

ABSTRACT:   In order to understand the characteristics of burnt meat in cultured yellowtail Seriola quinqueradiata , fish were kept at two different temperatures (13 and 30°C) and slaughtered by either spinal cord destruction (SCD) or suffocation in air (SA). Early postmortem changes during storage at 32°C were analyzed by rheological, biochemical, and histological methods. The burnt meat (with lightness parameter, L* ≥ 55) was observed at 1-h storage in the SA 30°C group, at 2 h in SCD 30°C, and at 4 h in SA 13°C; meat was normal for the SCD 13°C group until 6 h of storage. Breaking strength scores were higher for the normal meat (200 g/cm²) than burnt meat (70 g/cm²) at 4 h of storage. Expressible water content was higher for the burnt meat than for the normal meat. Adenosine triphosphate concentrations for the SCD groups were higher than for the SA counterparts. Moreover, pH decrease was much faster in the 30°C groups, showing pH 5.6 at 2 h of storage. A negative correlation between the pH and lactic acid contents in muscle ( P  < 0.001) was found. Histological analysis evidenced a larger pericellular area (40%) in the burnt samples than in the normal samples (16%). It was confirmed that a higher fish-keeping water temperature and a stressful slaughter method (faster glycolytic process) were determinative factors that influence the occurrence of burnt muscle in yellowtail, and that the effect of the former is larger than the latter.     

Re-emergence of multi-drug resistant <Emphasis Type="Italic">Salmonella enterica</Emphasis> serovar Stanley from cattle

During 2009, Salmonella enterica subspecies enterica serovar Stanley isolates were recovered from cattle diagnostic specimens in southern Japan, and the isolates were examined to characterize the genetic determinants involved in this new pathogenicity that associated with mortality in cattle. All the isolates were multi-drug resistance exhibited resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, oxytetracycline, and kanamycin (ACSSuT-Km) encoded by bla _TEM, catA, aadA1, sul1, tet(A), and aphA1 genes, respectively. Class 1 integrons of 1.5-kb size were detected in all MDR isolates. The isolates harboured easily transferable plasmids of ca. 210-kb with the potential of transmitting resistance phenotype and genotype detected in the donor isolates. XbaI-digested PFGE patterns generated two related clusters implicated in the dissemination of multi-drug resistance amongst Salmonella Stanley isolates. An emergence of multi-drug resistant Salmonella Stanley amongst food-producing animals, including cattle is a threat to human health, as resistant isolates may be transmitted to humans through the food chain.     

Glucocorticoid sensitivity depends on expression levels of glucocorticoid receptors in canine neoplastic mast cells

Glucocorticoid (GC) administration with or without other chemotherapeutic reagents is a commonly used option in the treatment of mast cell malignancies. However, the responsiveness of mast cell tumors to GC treatment varies in individuals, and the regulatory mechanisms determining the GC sensitivity of malignant mast cells remain unclear. Since the expression of the GC receptor (GR) has been reported to be associated with GC sensitivity in human neoplastic lymphocytes, we attempted to investigate the relationship between GR levels and GC sensitivity by using neoplastic mast cells derived from canine mast cell tumors (MCTs). To elucidate the regulatory mechanisms involved in GC responsiveness, we analyzed various canine MCT cell lines and tissue samples from dogs with MCT. While the proliferation of canine MCT cells was suppressed by the addition of GC to the culture, we found that MCT cells derived from humans and rodents, as well as canine lymphoma cells, responded poorly to GC. However, there were also some variations in responsiveness to GC treatment among canine MCT cell lines used in this study. Using real-time polymerase chain reaction and Western blot analysis, we elucidated the relationship between GR expression and responsiveness to GC in canine MCT cells. Furthermore, to assess the involvement of GR expression in GC sensitivity in vivo, clinical investigations were conducted on dogs with cutaneous MCT. Written informed consent was obtained from owners, and the affected dogs were treated with prednisolone (0.5-2.0 mg kg(-1)day(-1), administered orally) 1 or 2 weeks prior to the surgical removal of the tumors. Tumor volume was measured according to WHO criteria both before and after prednisolone treatment, and the GC sensitivity of each MCT was determined on the basis of the reduction in tumor volume. Of the 15 dogs with MCT, 11 responded to treatment with prednisolone completely or partially, whereas 4 dogs showed no response. Examination of clinical samples obtained by surgical removal revealed that GR expression levels were significantly lower in GC-resistant MCT tissues than in GC-sensitive MCT tissues. Thus, these results strongly indicate that GR expression may contribute to GC sensitivity in canine MCT.     

Mycobacterium ulcerans infection in an Indian flap-shelled turtle (Lissemys punctata punctata)

We report an atypical mycobacterial infection in an Indian flap-shelled turtle, Lissemys punctata punctata, that died in an aquarium in Japan. At necropsy, the turtle showed multiple white nodules on the capsular surface and parenchyma of various organs such as the liver, spleen, intestine, and lung. Histologically, granulomatous inflammation surrounding a central zone of necrosis was observed. Sections stained by the Ziehl-Neelsen method revealed numerous acid-fast bacilli in the cytoplasm of macrophages and in the central area of necrosis. The organisms were identified as a mycobacterial species by PCR and nucleotide sequence analysis and revealed 98-100% homology to M. ulcerans. This is, to our knowledge, the first report of mycobacteriosis due to M. ulcerans in a turtle.     

In vivo characteristics of a transplantable Marek's disease lymphoblastoid cell line, MDCC-MSB1-41C

A Marek's disease (MD) lymphoblastoid cell line, MDCC-MSB1-41C, was highly transplantable and lethal for chickens. Autopsies showed extensive metastasis in various organs. The transplantabilities of the parent cell line, MDCC-MSB1, and another derivative line, MDCC-MSB1-33C, were transient. MD virus (MDV) could be isolated from the kidneys but not from the peripheral blood leukocytes of chickens inoculated with the MSB1-41C cell line. In addition, anti-MDV antibodies were produced both in chickens inoculated with this cell line and in controls raised with inoculated chickens, but several attempts to isolate MDV from this cell line in vitro failed.     

Heterosis,recombination effects and genetic variability of egg composition in inbred lines of white leghorns and their crosses

1. Positive heterosis effects for the proportion of yolk, and negative heterosis for the proportion of albumen were found in crosses of six inbred Leghorn lines.

2. Three‐way crosses showed no consistent change in egg composition when compared with matched two‐way crosses.

3. Large differences in egg composition were found between inbred lines.

4. The egg composition of two‐way crosses was highly predictable from the performance of their parents, while specific combining effects as measured by deviations from offspring—parent regression were relatively unimportant.

     

Current status of leptospirosis in Japan and Philippines

Leptospirosis is an acute febrile illness with a wide variety of clinical manifestations and is encountered throughout the world, prominently in tropical areas with high rainfall. In this paper, we review the current status of leptospirosis in two Asian countries, Japan and Philippines, which have quite different situations in terms of economy, environment, infrastructures and prevailing infectious diseases. In Japan, until 1960, more than 200 deaths due to leptospirosis had been reported yearly. After 1960, the number of reported cases had rapidly decreased. Now, leptospirosis cases notified every year were less than 20. After the early 1960s, modernization of agriculture was introduced, at the same time, inactivated vaccine against Leptospira was applied for humans and there was good maintenance of infrastructures such as water works and sewage systems.

In Philippines, on the other hand, leptospirosis patients tend to be frequently found in flood-prone areas of urban setting such as Metro Manila, which was found to be the endemic foci of leptospirosis. Morbidity in a rural area (Cabatuan, Iloilo) was 147 cases per 100,000 populations. From 1998 to 2001, about 70% of 1200 suspected leptospirosis patients in Philippines were serologically positive. The average age of patients was 32 years old where 87% of the cases were males and 70% were outdoor workers. Case fatality rate was found to be 12–14%. The estimated major serovars in Metro Manila and neighboring provinces were Manilae, Losbanos, Tarassovi, Poi and an unknown serovar. Outbreaks of leptospirosis in the Philippines are thought to be associated with heavy rainfall, rapid urbanization (dramatic increase in populations), deforestation, increasing number of flood-prone areas, poor infrastructures and many others.     

Lysine decarboxylase-negative Salmonella enterica serovar enteritidis: antibiotic susceptibility, phage and PFGE typing

One hundred twenty Salmonella Enteritidis isolates collected from 1992 to 2005 in Nagasaki prefecture (65 isolates from 40 outbreak cases, 44 from sporadic diarrhea patients, and 11 from chicken-related products) were investigated by their antibiotic susceptibility profiles, phage typing, and pulsed-field gel electrophoresis (PFGE) typing. Out of them, 18 were identified as lysine decarboxylase (LDC)-negative isolates, and 15 showed resistance toward streptomycin. Based on the PFGE typing, the isolates were classified into five clusters by UPGMA clustering method. Three LDC-negative isolates belonged to cluster A and were of phage type (PT) 4 and isolated between 2000 and 2004. Other 15 LDC-negative isolates belonged to cluster E. They were PT1, reacted but did not conform (RDNC), or untypable and were isolated between 2001 and 2004. LDC-negative isolates of the cluster A differed from LDC-negative isolates of the cluster E in antibiotic susceptibility profiles, phage typing, and PFGE typing. LDC-negative isolates of the cluster E were isolated after 2001 in Nagasaki prefecture.     

Expression of monocarboxylate transporter 1 (MCT1) in the dog intestine

In this study, the expression and distribution of monocarboxyolate transporter 1 (MCT1) along the intestines (duodenum, jejunum, ileum, cecum, colon and rectum) of dogs were investigated at both the mRNA and protein levels. The expression of MCT1 protein and its distribution were confirmed by Western blotting and immunohistochemical staining using the antibody for MCT1. We identified mRNA coding for MCT1 and a 43-kDa band of MCT1 protein in all regions from the duodenum to the rectum. Immunoreactive staining for MCT1 was also observed in epithelial cells throughout the intestines. MCT1 immunoreactivity was greater in the large intestine than in the small intestine. MCT1 protein was predominantly expressed on the basolateral membranes along intestinal epithelial cells, suggesting that MCT1 may play an important role in lactate efflux and transport of short-chain fatty acids (SCFAs) to the bloodstream across the basolateral membranes of the dog intestine.