Antibiotic resistance of Aeromonas ssp. strains isolated from Sparus aurata reared in Italian mariculture farms.

Selective pressure in the aquatic environment of intensive fish farms leads to acquired antibiotic resistance. This study used the broth microdilution method to measure minimum inhibitory concentrations (MICs) of 15 antibiotics against 104 Aeromonas spp. strains randomly selected among bacteria isolated from Sparus aurata reared in six Italian mariculture farms. The antimicrobial agents chosen were representative of those primarily used in aquaculture and human therapy and included oxolinic acid (OXA), ampicillin (AM), amoxicillin (AMX), cephalothin (CF), cloramphenicol (CL), erythromycin (E), florfenicol (FF), flumequine (FM), gentamicin (GM), kanamycin (K), oxytetracycline (OT), streptomycin (S), sulfadiazine (SZ), tetracycline (TE) and trimethoprim (TMP). The most prevalent species selected from positive samples was Aeromonas media (15 strains). The bacterial strains showed high resistance to SZ, AMX, AM, E, CF, S and TMP antibiotics. Conversely, TE and CL showed MIC90 values lower than breakpoints for susceptibility and many isolates were susceptible to OXA, GM, FF, FM, K and OT antibiotics. Almost all Aeromonas spp. strains showed multiple antibiotic resistance. Epidemiological cut-off values (ECVs) for Aeromonas spp. were based on the MIC distributions obtained. The results showed a high frequency of Aeromonas spp. contamination in Sparus aurata reared on the Italian coast and an elevated biodiversity in isolated bacterial strains. Aeromonas isolates comprise potentially pathogenic species for humans, often resistant to several antibiotics and able to transfer the genes responsible for antibiotic resistance to microorganisms pathogenic for humans throughout the food chain. The few ECV studies available on many antibiotics against Aeromonas spp. strains isolated from the aquaculture environment highlight the need for further research in this area, while regular monitoring programmes should be stepped up to check for antibiotic resistance.

Activity of Catmint (Nepeta cataria) essential oil against Anisakis larvae.

Nepeta cataria L.,commonly known as Catnip, is an aromatic plant belonging to the mint family, Limiaceae. Nematicidal activity of Catnip essential oil (CEO), was assayed in vitro against L3 larvae of Anisakis type 1. Anisakidosis is one of the most important fishborne zoonotic diseases related to the ingestion of nematode larvae belonging to the genus Anisakis, Contraceacum and more rarely Pseudoterranova and Hysterothylacium. In vitro tests revealed a complete inactivation of parasites after 6 and 12 h of treatment, at 10 and 5% respectively, in saline solution. In marinating solution a complete inactivation of parasites was observed after 12 and 18 hours at 10 and 5% concentrations respectively. The data obtained showing a significant activity against Anisakis larvae and suggest further investigations on CEO as a larvicidal agent.

Bacteriological investigation on "Mauro" sold in Catania.

Seaweeds known as "Mauro" are traditionally used fresh or to prepare omelettes in Sicily (Italy). Twenty samples sold in Catania between May 2005 and September 2007 were analyzed for Escherichia coli, Total Enterobacteria, Aeromonas spp., Pseudomonas spp., Vibrio spp., and Salmonella spp. Thirty Vibrio strains were examined for the presence of the virulence genes, toxR, toxRS, tl, tdh, and trh in the genomes of the isolates. Total Enterobacteria ranged between 2.23 and 6.85 log CFU/g, and in six samples, E. coli ranged between 0.70 and 2.74 log CFU/g. Aeromonas spp. was present in samples between 1.0 and 5.90 log CFU/g, while Pseudomonas spp. ranged between 2.70 and 7.27 log CFU/g. Vibrio spp. was present in 75% of samples at values between 1.30 and 4.60 log CFU/g. The most frequently isolated species was V. alginolyticus (76.66% of isolates), of which 82.60% were positive for toxR and the remaining 17.40% of strains were positive for toxRS. V. parahaemolyticus was identified in 13.33% of strains; all were positive for toxR and, in one case, for both toxR and toxRS. V. coralliitycus was isolated in 6.66% of strains (all positive for toxR), and one was identified as V. mimicus (positive for toxRS). The results of this study suggest that there is need for stringent quality control during harvesting and distribution of Mauro.

Bacteria isolated from 25 hydatid cysts in sheep, cattle and goats.

Bacteria were isolated from 12 of 25 hydatid cysts collected from the lungs and livers of cattle, sheep and goats slaughtered in the province of Messina, Sicily, Italy. Citrobacter freundii was isolated from seven of the cysts, Aeromonas hydrophila from three, Staphylococcus species from two, Salmonella species from two and Escherichia coli and Proteus vulgaris from one.

Influence of slaughtering method on some aspects of quality of gilthead seabream and smoked rainbow trout.

The effects of several slaughter methods on the quality of fresh and smoked trout and fresh gilthead seabream were evaluated during storage at 2 degrees C. Electrically stunned trout had slower ATP depletion of raw muscle and lower lipid oxidation in smoked product during storage. Gilthead seabream immersed in an ice slurry (IS group) after the harvest showed a more regular ATP depletion than in fish exposed to CO2. Nevertheless, in the case of the IS group, self-initiated behaviour, response to handling and breathing all ceased only after 15-20 min, whereas carbon dioxide-stunned fish appeared dead after 5 min. However, gilthead seabream group having slower ATP depletion also showed lower lipid oxidation of muscle during storage. In both species this could be due to the rapid conversion of xanthine dehydrogenase to xanthine oxidase induced by the rapid consumption of ATP. Xanthine oxidase, in the presence of redox iron and reintroduced oxygen, can produce hydrogen peroxide and, consequently, hydroxyl radicals.

[Quantitative determination of urine bacteria in the diagnosis of urinary tract infections in children]. / La batterioscopia urinaria quantitativa nella diagnosi di infezione delle vie urinarie in età pediatrica.

Bacteria counts in fresh, unstained, uncentrifuged urine specimens, using a phase-contrast microscope, magnification X 400, and a hemocytometer chamber, proved to be a very useful method not only of excluding (specificity 0.92) but also identifying urinary tract infection (sensitivity 0.90) in children. The presence of greater than 5/0.1 ml bacteria in the urine was taken as the threshold value. The evaluation of leukocyturia alone did not alter the sensitivity of the method, even when it was associated with bacteriuria. When Proteus was isolated from urine cultures, the bacteria count proved negative in 60% of cases; otherwise when different bacteria were isolated in urine cultures, they were then identified during the bacteria count. The method is simple, inexpensive and rapid (it requires only a few minutes) and it may be used in a pediatric outpatient or hospital setting.