Few investigations on guided bone regeneration (GBR) focus on the behaviour of tissues adjacent to barrier membranes. This study was conducted to (1) evaluate the barrier function potential of different resorbable and nonresorbable membranes for GBR, (2) investigate their structural changes after different intervals, and (3) characterize tissue composition and reaction adjacent to the barrier by qualitative histologic evaluation. Seven barriers for GBR were used per animal (made of dense or expanded polytetrafluoroethylene (d/ePTFE), titanium, polyetherurethane, collagen and two polylactide-polyglycolide-/-trimethylenecarbonate-co-polymers (PLPG, LPGTC) in standardized defects not exceeding the critical size) without using bone substitution material or autogenous bone at the right inferior margin of the mandibles of six domestic pigs. Samples of the defect areas with membranes were harvested after 2 days (one animal), 4 and 8 (two animals, each) and 12 weeks (one animal), respectively. The healing of bone defects was completed in all animals after 12 weeks. Nonresorbable barriers prevented the soft tissue in-growth into standardized defects. Thinner layers of fibrous tissue were seen underneath the dense and rigid barriers (dPTFE, titanium) when compared with collagen and PLPG/LPGTC, in which soft-tissue plugs occupied the crestal defect portion. PLPG-/LPGTC-barriers underwent structural changes after 4 weeks and revealed blistered central layers, whereas structural changes were not evident in nonresorbable barriers. The degradation of PLPG-/LPGTC-membranes was present with in-growth of fibres, vessels, and cells. Using collagen or synthetic polymer barriers for GBR, the application of bone or bone substitutes to prevent membrane prolapse into the defect is suggested.
Edwardsiella tarda is a pathogen that causes edwardsiellosis in aquatic animals. The emergence of multiple antibiotic‐resistant strains makes antibiotic treatment difficult. This study aimed to investigate the antibiotic susceptibility patterns and the genotypic characterization of E. tarda isolated from cage‐cultured red tilapia in Thailand. A total of 30 isolates were identified as E. tarda using biochemical and molecular analysis. The disc diffusion method for testing antibiotic susceptibility showed all the isolates were resistant to colistin sulphate and oxolinic acid. High levels of resistance to amoxicillin, ampicillin, ceftazidime, oxytetracycline and sulphamethoxazole/trimethoprim were observed as well. The multiple antibiotic resistance index ranged from 0.25 to 0.92, indicating that these isolates had been exposed to high risk sources of contamination where antibiotics were commonly used. All the isolates carried the blaTEM gene based on polymerase chain reaction (PCR). The tetA and sul3 genes were detected in 90% (27/30) and 26.7% (8/30) of the isolates respectively. Nine different genetic groups of isolates were obtained using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC‐PCR). A correlation between genetic types and multiple antibiotic‐resistant patterns was found. These results highlight the potential risks of multiple antibiotic‐resistant isolates for humans and the environment.
A cDNA of Japanese flounder (Paralichthys olivaceus) CC chemokine designated as Paol-SCYA104 was cloned and sequenced. The cDNA contains an opening reading frame of 315 nucleotides encoding 104 amino acid residues. The full gene was cloned and sequenced from a BAC library. It has a length of approximately 750 bp from the start codon to the stop codon and is composed of four exons and three introns. Four cysteine residues are conserved in the same positions as those of mammalian and fish CC chemokines. Paol-SCYA104 gene was expressed in several organs, including peripheral blood leukocytes (PBLs), head kidney, trunk kidney, and spleen. The recombinant Paol-SCYA104 was expressed in Escherichia coli and the expressed protein was partially purified. The recombinant Paol-SCYA104 was able to attract Japanese flounder PBLs in a microchemotaxis chamber. On the other hand, a negative control, the fraction of the control cells carrying an expression vector lacking the Paol-SCYA104 cDNA, did not show chemotactic activity. These results indicate that Paol-SCYA104 probably acts as a CC chemokine.
We cloned the cDNA and genes of two different types of CC chemokine from Japanese flounder Paralichthys olivaceus. The genes were designated JFCC1 and JFCC2. The JFCC1 cDNA encoded 91 amino acid residues. The JFCC1 gene has a size of 1.9 kb and consists of three exons and two introns. Two types of JFCC2 mRNA, corresponding to genes designated JFCC2‐1 and JFCC2‐2, were detected by reverse transcription–polymerase chain reaction in several organs, although fully spliced mRNA was not detected. The sizes of JFCC2‐1 and ‐2 were 1.9 kb and 1.8 kb, respectively. JFCC2‐1 consists of three exons and two introns and JFCC2‐2 consists of two exons and one intron, although the coding regions of the two genes are identical. Because the JFCC2 gene has uncommon properties and an uncommon expression pattern, we suggest that it is a pseudogene. Southern blot hybridization and the characterization of BAC clones indicated that both the JFCC1 and JFCC2 genes exist as multicopy genes in the Japanese flounder genome. JFCC1 and JFCC2 genes were expressed in several organs including peripheral blood leukocytes (PBL) and kidney. The two forms of JFCC2 mRNA were also encountered in these cells. Expressions of JFCC1 and JFCC2 genes were upregulated after stimulation with concanavalin A/phorbol myristate acetate and lipopolysaccharide, compared with normal PBL.
Streptococcus spp. are major pathogenic bacteria associated with massive mortality in tilapia. This study investigated the phenotypic and genotypic characterization of Streptococcus agalactiae (GBS) and Streptococcus iniae (S. iniae) isolated from tilapia in river-based floating cage and earthen pond farms in northern Thailand. Isolates were identified by biochemical and molecular analyses. Capsular typing, enterobacterial repetitive intergenic consensus polymerase chain reaction and multilocus sequence typing were performed to investigate the genetic relatedness. Six and one isolates were confirmed as GBS and S. iniae, respectively. All Streptococcus spp. isolates were obtained from 4 river-based cage farms (4/33), while samples collected from earthen pond farms (N = 28) were negative for streptococcosis. All GBS with serotype Ⅲ and sequence type (ST) 283 was observed. The β-haemolytic GBS isolates were resistant to five antimicrobials, while the S. iniae was susceptible to all antimicrobials. This study indicates both GBS and S. iniae are the major bacterial pathogens responsible for streptococcosis infection in farmed tilapia of northern Thailand with GBS as dominant species. This survey highlights that the river-based cage farms seriously impact on the healthy development of the tilapia industry. K E Y W O R D Searthen pond farm, northern Thailand, river-based cage farm, Streptococcus spp., tilapia ACK N OWLED G EM ENTS
Francisella sp. is an emerging bacterial pathogen affecting tilapia Oreochromis niloticus This study surveyed presence of Francisella sp. in tilapia raised in Yunnan Province, south-western China along with water quality parameters and management practices. A total of 224 tilapia specimens were sampled from 28 farms between June and September 2017. Necropsy of the sampled fish revealed no granulomatous lesions and the standard bacterial isolation protocols proved negative for Francisella sp. However, the presence of Francisella sp. was confirmed by polymerase chain reaction in 18 samples (8%) from 8 of the 28 farms (28.6%) sampled, though no increasing mortality was reported from these farms. The 16S ribosomal RNA gene sequences revealed 99.7% identity with F. noatunensis sub sp. orientalis. The presence of Francisella sp. infection showed significant association with water temperature.
Curriculum mapping provides a systematic approach for analyzing the conformity of an educational program with a given set of standards. The Chiang Mai University Faculty of Veterinary Medicine and the University of Minnesota College of Veterinary Medicine joined together in an educational twinning project to map their Doctor of Veterinary Medicine curricula against core competencies identified by the World Organisation for Animal Health (OIE) as critically important for Day 1 veterinary graduates to meet the needs for global public good services. Details of curriculum coverage for each specific and advanced competency were collected through a review of syllabi and course descriptions, followed by in-depth interviews of key faculty members. The depth of coverage of each competency was estimated by the tabulating the number of hours assigned. The teaching methods and levels of learning were also captured. While the overall design of the curricula conformed to the OIE Guidelines for Veterinary Education Core Curricula, the mapping process identified variability in the depth and breadth of coverage on individual competencies. Coverage of the Day 1 Specific Competencies was greater early in the curricula. More gaps existed in terms of the Advanced Competencies than the specific core competencies. Discussion of the identified gaps with faculty members led to opportunities for strengthening the curricula by adjustments of individual courses throughout the curricula. Documentation of teaching methods also led to professional development of new pedagogical skills and redesign of the teaching methods for particular subjects.
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