Deciphering microbial communities of three Savoyard raw milk cheeses along ripening and regarding the cheese process.

Different Savoyard cheeses are granted with PDO (Protected Designation or Origin) and PGI (Protected Geographical Indication) which guarantees consumers compliance with strict specifications. The use of raw milk is known to be crucial for specific flavor development. To unravel the factors influencing microbial ecosystems across cheese making steps, according to the seasonality (winter and summer) and the mode of production (farmhouse and dairy factory ones), gene targeting on bacteria and fungus was used to have a full picture of 3 cheese making technologies, from the raw milk to the end of the ripening. Our results revealed that Savoyard raw milks are a plenteous source of biodiversity together with the brines used during the process, that may support the development of specific features for each cheese. It was shown that rinds and curds have very contrasted ecosystem diversity, composition, and evolution. Ripening stage was selective for some bacterial species, whereas fungus were mainly ubiquitous in dairy samples. All ripening stages are impacted by the type of cheese technologies, with a higher impact on bacterial communities, except for fungal rind communities, for which the technology is the more discriminant. The specific microorganism's abundance for each technology allow to see a real bar-code, with more or less differences regarding bacterial or fungal communities. Bacterial structuration is shaped mainly by matrices, differently regarding technologies while the influence of technology is higher for fungi. Production types showed 10 differential bacterial species, farmhouses showed more ripening taxa, while dairy factory products showing more lactic acid bacteria. Meanwhile, seasonality looks to be a minor element for the comprehension of both microbial ecosystems, but the uniqueness of each dairy plant is a key explicative feature, more for bacteria than for fungus communities.

Microsporum praecox: molecular identification of a new case and review of the literature.

We report a rare case of dermatophytosis due to Microsporum praecox in a 28-year-old female horse rider. The skin lesion was located on the right external malleolus. Microscopic examination of skin scrapings revealed a dermatophyte which was also isolated in culture. The identification of M. praecox was confirmed by molecular biology (sequence analysis of PCR products amplified from internal transcribed spacer regions with universal primers). Combined antifungal therapy with oral terbinafine and topical cyclopiroxolamide resulted in complete remission of the fungal lesion within 1 month. Since 1944, only 29 cases of human M. praecox infection have been reported in the literature. The clinical features and treatment of these cases are reviewed. The prevalence of M. praecox infection is probably underestimated, and systematic molecular identification could improve our understanding of the epidemiology of this fungal dermatosis.

Spatial distribution of soil contamination by Toxoplasma gondii in relation to cat defecation behaviour in an urban area.

In urban areas, there may be a high local risk of zoonosis due to high densities of stray cat populations. In this study, soil contamination by oocysts of Toxoplasma gondii was searched for, and its spatial distribution was analysed in relation to defecation behaviour of cats living in a high-density population present in one area of Lyon (France). Sixteen defecation sites were first identified. Cats were then repeatedly fed with marked food and the marked faeces were searched for in the defecation sites. Of 260 markers, 72 were recovered from 24 different cats. Defecation sites were frequented by up to 15 individuals. Soil samples were also examined in order to detect the presence of T. gondii using real-time PCR. The entire study area was then sampled according to cat density and vegetation cover type. Only three of 55 samples were positive and all came from defecation sites. In a second series of observations, 16 defecation sites were sampled. Eight of 62 samples tested positive, originating in five defecation sites. Laboratory experiments using experimental seeding of soil showed that the inoculated dose that can be detected in 50% of assays equals 100-1000oocysts/g, depending on the strain. This study shows that high concentrations of oocysts can be detected in soil samples using molecular methods and suggests that spatial distribution of contamination areas is highly heterogeneous. Positive samples were only found in some of the defecation sites, signifying that at-risk points for human and animal infection may be very localised.

New Vidas assay for Toxoplasma-specific IgG avidity: evaluation on 603 sera.

After the development of the new version of the test Vidas Toxo IgG with antigens obtained from tachyzoites cultured on cells, a Vidas avidity test has been recently developed. The aim of this study was to assess the value of the determination of avidity on the new Vidas test. This avidity test was performed on 553 sera obtained from pregnant women whose dates of infection had been determined and on 50 sera obtained from immunosuppressed patients. In the group of infection occurring less than 4 months before sampling, the avidity index was <0.3 on 266 among 267 sera. In the group of infection occurring more than 15 months before sampling, the avidity index was >0.3 for 44/46 sera of pregnant women and for 47/47 sera of immunosuppressed patients. Thus, the new version of avidity test was helpful primarily to rule out that an infection had occurred within the prior 4 months.

Usefulness of quantitative polymerase chain reaction in amniotic fluid as early prognostic marker of fetal infection with Toxoplasma gondii.

OBJECTIVE: Our purpose was to evaluate Toxoplasma gondii concentration in amniotic fluid (AF) samples as a prognostic marker of congenital toxoplasmosis. STUDY DESIGN: A retrospective study was carried out in 88 consecutive AF samples from 86 pregnant women, which were found positive by prospective polymerase chain reaction (PCR) testing. Parasite AF concentrations were estimated by real-time quantitative PCR and analyzed in relation to the clinical outcome of infected fetuses during pregnancy and at birth, taking into account the gestational age at maternal infection. RESULTS: A significant negative linear regression was observed between gestational age at maternal infection and T gondii DNA loads in AF. After adjusting for time at maternal seroconversion by multivariate analysis, higher parasite concentrations were significantly associated with a severe outcome of congenital infection (odds ratio [OR]=15.38/log (parasites/mL AF) [95% CI=2.45-97.7]). CONCLUSION: PCR quantification of T gondii in AF can be highly contributive for early prognosis of congenital toxoplasmosis. Maternal infections acquired before 20 weeks with a parasite load greater than 100/mL of AF have the highest risk of severe fetal outcome.

Investigation of Neospora sp. antibodies in aborted mares from Normandy, France.

Neospora caninum, an apicomplexan protozoan parasite, is recognized as a major cause of abortion in cattle while limited information is presently available on association between equine Neospora infections and abortions. The aim of the present study was to document prevalence of antibodies against Neospora sp. in aborted mares as a clue to the role of N. caninum in mare reproductive failure in Normandy, France. Using an agglutination test, the number of animals with elevated (>80) anti-Neospora sp. antibody titer was higher in a group of 54 aborted mares than in randomly chosen groups of 45 mares and 76 horses sampled for equine arteritis virus and Fasciola hepatica antibodies, respectively (P<0.001). N. caninum DNA was found in 3/91 fetal brains, 2/77 fetal hearts, and 1/1 placenta, and present in both brains and hearts of two fetuses. In 13 cases for which both mare serum and fetus were available, no fetal N. caninum amplification product was present while a large variation of maternal antibody titers was found. Data prompt at additional surveys of association between equine reproductive failure and Neospora sp. infection.

Comparison of PCR-enzyme-linked immunosorbent assay and real-time PCR assay for diagnosis of an unusual case of cerebral toxoplasmosis in a stem cell transplant recipient.

A PCR-enzyme-linked immunosorbent assay and a real-time PCR assay were compared for diagnosis and follow-up of cerebral toxoplasmosis in a stem cell transplant recipient. The sensitivity of detection was similar for both assays but was higher when the assays were performed on buffy coat rather than on whole blood or serum.

Delayed Salmonella bacteriuria in a patient infected with Schistosoma haematobium.

The authors report a case of Schistosoma haematobium infection with delayed occurrence of Salmonella bacteriuria following treatment of schistosomiasis. Standard models of interaction between these two pathogens may not be fully satisfactory in such a case of co-infection. The role played by a decreased host immune response following schistosomiasis may thus be highlighted to explain a delayed or prolonged infection with Salmonella.

Diagnosis of toxoplasmic retinochoroiditis with atypical clinical features.

PURPOSE: To determine the value of aqueous humor analysis for confirming the diagnosis of ocular toxoplasmosis in patients who present with atypical clinical features and to relate the results of local antibody production and polymerase chain reaction (PCR) with the extent of active retinitis and the immune status of the patient. DESIGN: Retrospective case series. METHODS: Sixty-seven consecutive patients with retinitis or retinochoroiditis that was clinically consistent with atypical ocular toxoplasmosis underwent diagnostic anterior chamber paracentesis and serological studies. The aqueous humor was analyzed both by PCR to detect Toxoplasma gondii B1 gene and by the Goldman-Witmer coefficient to determine levels of local anti-T. gondii antibody production. RESULTS: In nine of the 67 cases, PCR was positive for T. gondii; seven of these were negative for local antibody production. All nine patients had illnesses associated with immunosuppression or advanced old age and all had active retinitis with a mean area of 11.5 disk areas (DA). Twenty-five of the remaining 58 cases were positive for local antibody production. These 25 had a mean area of active retinitis measuring 2.6 DA, and 24 of these patients were immunocompetent. All 34 cases with laboratory evidence of ocular toxoplasmosis diagnosed by either method responded to anti-T. gondii agents. The remaining 33 were negative for T. gondii infection by these two methods; some had laboratory evidence of other infections. CONCLUSIONS: Although in the present study, the sensitivity and specificity of the aqueous humor PCR and Goldman-Witmer coefficient could not be ascertained in the laboratory diagnosis of toxoplasmic retinochoroiditis, the PCR method appears to confirm the diagnosis in immunocompromised individuals with large atypical foci of retinitis. Conversely, determination of local antibody production may be appropriate for proper diagnosis in immunocompetent individuals presenting with small foci of retinitis.