Leuconostoc gelidum and Leuconostoc gasicomitatum strains dominated the lactic acid bacterium population associated with strong slime formation in an acetic-acid herring preserve

http://www.elsevier.com/locate/issn/01681605Spoilage characterised by strong slime and gas formation affected some manufacture lots of 2 an acetic-acid Baltic herring (Culpea haerengus membras) preserve after few weeks’ storage 3 at 0-6°C. The product consisted of herring filets in acetic acid marinade containing sugar, 4 salt, allspice and carrot slices. Microbiological analyses of the spoiled product showed high 5 lactic acid bacterium (LAB) levels ranging from 4.5 ×108 to 2.4 × 109 CFU/g. Yeasts were 6 not detected in any of the herring samples. Since LAB contaminants seldom are associated 7 with fresh fish, LAB populations associated with marinade ingredients (carrots, allspice) 8 were also analysed. The highest LAB levels exceeding 107 CFU/g were detected in 9 equilibrium modified atmosphere packaged baby carrots whereas the levels detected in the 10 allspice samples did nor exceed 4.3 × 105. A total of 176 randomly selected LAB isolates 11 originating from herring, carrot and allspice samples were further identified to species level 12 using a 16 and 23S rRNA gene RFLP (ribotyping) database. Leuconostoc gelidum and 13 Leuconostoc gasicomitatum strains dominated both in the spoiled herring and carrot samples. 14 These species are heterofermentative producing CO2 from glucose and they also produce 15 dextran from sucrose. Inoculation of some commercial herring products with spoilage- 16 associated L. gelidum and L. gasicomitatum strains verified that these strains have the 17 capability of producing slime and gas in herring preserves although slime formation was not 18 as strong as in the original samples. Since L. gelidum and L. gasicomitatum strains were 19 commonly detected in carrots, carrot slices used for the fish marinade were considered to be 20 the probable source of these specific spoilage organisms. 2

A biodegradable antibiotic delivery system based on poly-(trimethylene carbonate) for the treatment of osteomyelitis

Background and purpose Many investigations on biodegradable materials acting as an antibiotic carrier for local drug delivery are based on poly(lactide). However, the use of poly(lactide) implants in bone has been disputed because of poor bone regeneration at the site of implantation. Poly(trimethylene carbonate) (PTMC) is an enzymatically degradable polymer that does not produce acidic degradation products. We explored the suitability of PTMC as an antibiotic releasing polymer for the local treatment of osteomyelitis

Nanocrystalline hydroxyapatite and zinc-doped hydroxyapatite as carrier material for controlled delivery of ciprofloxacin

In bone disorders infections are common. The concentration of majority of antibiotics is very low in the bone tissue. A high local dose can be obtained from the ciprofloxacin-loaded hydroxyapatite nanoparticles. The present study is aimed at developing the use of hydroxyapatite and zinc-doped hydroxyapatite nanoparticles as a carrier for ciprofloxacin drug delivery system. The ciprofloxacin-loaded hydroxyapatite and zinc-doped hydroxyapatite have a good antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus. Hydroxyapatite and zinc-doped hydroxyapatite were prepared and characterized using X-ray diffraction, Transmission electron microscopy and inductively coupled plasma optical emission spectrometry. They were loaded with ciprofloxacin using optimized drug loading parameters. Drug loading, in vitro drug release and antimicrobial activity were analyzed. The influence of zinc on the controlled release of ciprofloxacin was analyzed. The results show that the presence of zinc increases the drug release percentage and that the drug was released in a controlled manner

Technical Improvement To Prevent DNA Degradation of Enteric Pathogens in Pulsed-Field Gel Electrophoresis

This study used a modified pulsed-field gel electrophoresis (PFGE) method with HEPES as a running buffer to prevent electrophoresis-related DNA degradation of nine Salmonella enterica subsp. enterica serovar Ohio, seven Salmonella serovar Newport, and two enterohemorrhagic Escherichia coli (non-O157) strains. All strains yielded identifiable bands with this method in contrast to a commonly applied PFGE method using Tris buffer

Role of Broiler Carcasses and Processing Plant Air in Contamination of Modified-Atmosphere-Packaged Broiler Products with Psychrotrophic Lactic Acid Bacteria

Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmosphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of HindIII restriction fragment length polymorphism (RFLP) patterns of the 16 and 23S rRNA genes as operational taxonomic units in numerical analyses. Six hundred thirteen LAB isolates from the total of 655 clustered in 29 groups considered to be species specific. Sixty-four percent of product isolates clustered either with Carnobacterium divergens or with Carnobacterium maltaromaticum type strains. The third major product-associated cluster (17% of isolates) was formed by unknown LAB. Representative strains from these three clusters were analyzed for the phylogeny of their 16S rRNA genes. This analysis verified that the two largest RFLP clusters consisted of carnobacteria and showed that the unknown LAB group consisted of Lactococcus spp. No product-associated LAB were detected in broiler carcasses sampled at the beginning of slaughter, whereas carnobacteria and lactococci, along with some other specific meat spoilage LAB, were recovered from processing plant air at many sites. This study reveals that incoming broiler chickens are not major sources of psychrotrophic spoilage LAB, whereas the detection of these organisms from the air of the processing environment highlights the role of processing facilities as sources of LAB contamination

Efficacy of Ciprofloxacin-Releasing Bioabsorbable Osteoconductive Bone Defect Filler for Treatment of Experimental Osteomyelitis Due to Staphylococcus aureus

The concept of local antibiotic delivery via biodegradable bone defect fillers with multifunctional properties for the treatment of bone infections is highly appealing. Fillers can be used to obliterate surgical dead space and to provide targeted local bactericidal concentrations in tissue for extended periods. Eventually, the osteoconductive component of the filler could guide the healing of the bone defect. The present experimental study was carried out to test this concept in a localized Staphylococcus aureus osteomyelitis model in the rabbit (n = 31). A metaphyseal defect of the tibia was filled with a block of bone cement, followed by insertion of a bacterial inoculum. After removal of the bone cement and surgical debridement at 2 weeks, the defect was filled with a ciprofloxacin-containing (7.6% ± 0.1%, by weight) composite (treated-infection group) or with a composite without antibiotic (sham-treated group). Both a positive control group (untreated-infection group) and a negative control group were also produced. The treatment response, monitored by positron emission tomography (PET) with fluorine-18-labeled fluorodeoxyglucose ([(18)F]FDG) at 3 and 6 weeks, showed rapidly decreasing amounts of [(18)F]FDG uptake in the treated-infection group (P = 0.001 compared with the results for the untreated-infection group at 6 weeks). The bacteriological analysis confirmed the eradication of the bone pathogen in the treated-infection group. However, three animals had culture-positive soft tissue infections. All animals in the sham-treated and untreated-infection groups had culture-positive bone infections with typical radiographic changes of osteomyelitis. Histomorphometry, peripheral quantitative computed tomography, and backscattered electron imaging of scanning electron microscopy images verified the osteoconductive properties of the bioactive glass microspheres within the composite. The median bone ciprofloxacin concentrations were 1.2 and 2.1 μg/g at two anatomic locations of the tibia. This is the first report to show the value of [(18)F]FDG PET for quantitative monitoring of the treatment response in bone infections. The collaborative results of bacteriologic and [(18)F-FDG] PET studies showed that use of the multifunctional composite was successful for eradication of the S. aureus pathogen from bone