Human and canine leishmaniasis in asymptomatic and symptomatic population in Northwestern Greece.

The occurrence of human and canine Mediterranean visceral leishmaniasis (MVL) in Northwestern Greece was investigated during an 8-year survey (1994-2001). A total of 1200 blood sera samples, collected from asymptomatic human population, and 1200 blood sera samples from asymptomatic dogs were screened for Leishmania infantum antibodies using the indirect immunofluorescence test (IFA). Also during the survey 111 human subjects and 350 canines were referred as clinically suspect cases for MVL. Significant differences (p = 0.001) were found between the prevalence of MVL in symptomatic and asymptomatic human populations (12.6 and 0.5%, respectively), but a more modest difference was observed between symptomatic and asymptomatic canines (45.4 and 24.4%, respectively). From the results, it appears that Greece has a high background of canine leishmaniasis, which is likely to be a risk factor for the emergence of human MVL.

Distribution of Clostridium perfringens in polluted lake environments.

Many of the directives that relate to the prevention of pollution or the improvement of fresh water also relate to lake waters since lake waters ultimately inherit much of the pollution that enters into fresh water. In order to determine the influence of the water depth on Clostridium perfringens, we utilised a new medium, lactose-sulfite (LS) broth, suggested for rapid enumeration and identification of C. perfringens. Duplicate samples were collected at each one of the following sites of the polluted station: surface, 60 cm, 90 cm and bottom (1.18 cm). Membrane filtration equipment was used. All samples were alternatively passed through two membrane filters, the first (20-25 microm pore size) was used for retention of the abundant phytoplankton and the second (porosity 0.45 microm) for C. perfringens. Membranes were placed into the first tube of ten-fold dilutions from 10(1) to 10(4) and incubated aerobically in a waterbath at 46 degrees C for 24 h. The numbers of C. perfringens fluctuated depending on the water depth. Vegetative forms were found only in the bottom sampling; they were never found in surface, 60 cm and 90 cm sampling sites. Sporulated forms were found in all sampling sites with the exception of the surface sampling. Clostridium perfringens as an anaerobic bacterium never occurred in the surface waters in vegetative or spore forms, even if the waters were extremely polluted by domestic or industrial activities. Vegetative forms occurred only in the bottom samples but spore forms which are more resistant to various environmental effects occurred in all depths except for the surface.

Bacterial strains isolated from eggs and their resistance to currently used antibiotics: is there a health hazard for consumers?

In order to study the putative transfer of antibiotic resistance from poultry to humans, hens' eggs were examined for the presence of various pathogens. Staphylococcus, Enterobacter, Escherichia, Proteus and Pseudomonas spp. were the most frequently isolated genera. Sensitivity tests, performed with the Kirby-Bauer technique, showed the presence of resistant strains of Staphylococcus aureus (to penicillin-G, tetracycline, erythromycin, clindamycin, cefalosporins, oxacillin, gentamycin, chloramphenicol and tobramycin), Enterococcus faecalis (to ampicillin, ciprofloxacin, clindamycin, gentamycin and tetracyclin), Escherichia coli (to tetracycline, erythromycin, ampicillin and cefalosporins), Enterobacter cloacae (to ampicillin, amoxycillin plus clavunalic acid, erythromycin and tetracycline), Pseudomonas stutzeri (to erythromycin and chlorampenicol) and Citrobacter freundii (to ampicillin, amoxycillin plus clavunalic acid, cefalosporins and co-trimoxazole).

Survival of enterobacteria in liquid cultures during microwave radiation and conventional heating.

Bacteria in food have been reported to survive in larger numbers after processing by microwave radiation than after conventional processing. The bactericidal effect of a domestic microwave oven (SHARP R-7280) on certain pathogenic enterobacteria species was investigated in vitro, in comparison with conventional heating (boiling). The death rates of different nosocomial strains of Escherichia coli, Salmonella sofia, Salmonella enteritidis, Proteus mirabilis and Pseudomonas aeruginosa were tested. The microwave oven and the conventional heating system used were both calibrated in order to calculate temperatures from exposure times. For each strain duplicate samples of 25 ml of pure culture with concentrations at least 10(6) cfu/ml were exposed to microwave radiation. An equal number of samples of the same volume and concentration were exposed to conventional heating. Subsequently all samples were examined qualitatively and quantitatively following standard microbiological procedures. The results indicate that microwaves have an efficient bactericidal effect on the enterobacteria in liquid cultures.

Distribution of Clostridium perfringens in different aquatic environments in Greece.

Clostridium perfringens and especially its spores, which are more tolerant to various physiochemical effects than the other fecal indicator bacteria, could serve as a useful indicator in ecosystems with stress factors. In order to determine the numbers of Clostridium perfringens in waters of rural North-West Greece, we utilised a new medium, lactose-sulfite (LS) broth, suggested for rapid enumeration and identification of Clostridium perfringens without the necessity for further confirmatory tests. Membrane filtration equipment was used on site. All samples were alternatively passed through two membrane filters, one (20-25 microns pore size) was used for retention of the abundant phytoplankton and the other (porosity 0.45 micron) for Clostridium perfringens. Membranes were placed into the first tube of 10-fold dilutions from 10(1) to 10(4) and incubated aerobically in a water-bath at 46 degrees C for 24 h. The numbers of Clostridium perfringens revealed fluctuations depending on the sampling site. It was significantly more common in the vicinity of industrial or domestic activities. LS broth not only allows the detection of small numbers of Clostridium perfringens but also permits rapid detection within 24 h. We propose the medium and the procedures described in this paper as a reliable technique for estimation of Clostridium perfringens as indicator of fecal contamination in waters.