There is a need to develop simple, rapid, and accurate methods for assessing health in fish populations. In this study we demonstrate that use of fluorescein, a nontoxic fluorescent dye, can rapidly and easily detect the presence of skin ulcers in all fish tested, including rainbow trout (Oncorhynchus mykiss), channel catfish (Ictalurus punctatus), goldfish (Carassius auratus), and hybrid striped bass (Morone saxatilis male X M. chrysops female). Exposure of fish to as little as 0.10 mg fluorescein per milliliter of water for 3 minutes was sufficient to identify experimentally induced lesions, even pinpoint ulcerations. Such lesions were not visible to the naked eye but were clearly demarcated with fluorescein treatment. Examination of fish that appeared clinically normal often revealed the presence of focal ulcerations, which might have been a consequence of damage during capture, but it also might suggest that skin ulceration may be common even in “clinically normal” fish. Exposure of either nonulcerated or experimentally ulcerated hybrid striped bass to an excessively high concentration of fluorescein had no apparent effect on health or survival. Our studies suggest that fluorescein may be a highly useful tool for rapid health screening in fish populations.

The objective of this study is evaluating the efficacies of 11 mycotoxin adsorbent products, marketed in South East Asia. Three prominently occurring mycotoxins; aflatoxin B1 (AFB1), deoxynivalenol (DON), and zearalenone (ZEN) were simultaneously spiked into the samples. Samples were simultaneously tested in vitro in phosphate buffer and simulated at different pH conditions in the gastrointestinal tracts of the porcine and avian model, analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). All mycotoxin adsorbent products had high efficacy at over 90% for AFB1 adsorption in both GI porcine and avian models. AFB1 could be adsorbed more in acidic condition than the basic condition. ZEN adsorption was determined to be more stable at pH 3 than pH 6.5 or 8.4, in which pH condition might influence on ZEN desorption rate. DON was poorly adsorbed by all tested agents. The finding showed that the adsorption rate varied depending on the type of adsorbent. Our results might provide useful information regarding the efficacy of mycotoxin adsorbents commercially marketed in the region.

Antibiotic beads have become popular for the treatment of local bacterial infections. The preparation of antibiotic beads from commercial pharmaceutical antibiotics is a convenient method in clinic. The elution characteristics of cefazolin from polymethylmethacrylate (PMMA) (SmartSet HV, Depuy I and Cemfix 3) beads and calcium sulfate beads were studied. Commercial cefazolin formulation was incorporated in PMMA or calcium sulfate at 1 g cefazolin /10 g of matrix substances to form beads. The concentrations of eluted cefazolin during 15 days were greater than MIC for Staphylococcus aureus (ATCC 25923). The eluted cefazolin concentrations were in the range of 3.6 ± 1.2 to 4.6 ± 0.4 mg for PMMA beads and 15.4 ± 1.7 mg for calcium sulfate beads. The accumulated eluted cefazolin from PMMA beads and calcium sulfate beads for 15 days were 34.41 ± 3.93 to 38.67 ± 3.04% and 95.94 ± 3.93%, respectively. The various storage conditions; at room temperature or 4°C, with or without light-protection, for 6 months had little effects on the amounts of eluted cefazolin. The results showed both in-housed cefazolin-PMMA beads and cefazolin-calcium sulfate beads could be the effective tools for the treatment of local bacterial infections.

Porous oligolactide-hydroxyapatite composite scaffolds were obtained by stereolithographic fabrication. Gentamicin was then coated on the scaffolds afterwards, to achieve antimicrobial delivery ability to treat bone infection. The scaffolds examined by stereomicroscope, SEM, and μCT-scan showed a well-ordered pore structure with uniform pore distribution and pore interconnectivity. The physical and mechanical properties of the scaffolds were investigated. It was shown that not only porosity but also scaffold structure played a critical role in governing the strength of scaffolds. A good scaffold design could create proper orientation of pores in a way to strengthen the scaffold structure. The drug delivery profile of the porous scaffolds was also analyzed using microbiological assay. The release rates of gentamicin from the scaffolds showed prolonged drug release at the levels higher than the minimum inhibitory concentrations for S. aureus and E. coli over a 2-week period. It indicated a potential of the scaffolds to serve as local antibiotic delivery to prevent bacterial infection.

An epidemic of trichodinosis associated with severe epidermal hyperplasia occurred in adult largemouth bass (Micropterus salmoides) from the Chowan River drainage, North Carolina (USA) in late winter to early spring 2002. Initial reports by anglers of fish with a "jelly-like slime coat" on the skin prompted an electrofishing survey in which about 10% of sampled largemouth bass had a very thick, bluish-white "mucoid layer" on the body and fins. Moderate to heavy infestations of the ciliate Trichodina were detected in wet mounts of skin from five of five fish having the mucoid layer; these fish also had significant gill infestations. An additional two fish with only mild reddening and four asymptomatic fish (no skin lesions) had mild skin infestations but no gill infestations. Two asymptomatic fish had no skin parasites. Four fish with the mucoid layer were necropsied and had extremely severe epidermal hyperplasia on the body and fins. The hyperplasic epidermis had relatively few mucus cells and typically was about 5-10 times thicker than healthy epidermis. The upper four fifths of the epidermis consisted of finely vacuolated, highly flattened, somewhat disorganized epithelial cells. No other significant clinical or histopathologic abnormalities were detected. No systemic infection by pathogenic bacteria was noted. The environmental cause of the epidemic is uncertain but the lesions suggest that some chronic stressor was involved.