Identification and further characterization of Enterobacteriaceae and Cronobacter spp. in a milk powder and infant processing plant

Due to technical reasons, milk powder and powdered infant formulae (PIF) are not sterile products. In order to achieve the requirements set by the Swiss and European regulations for microbiologic criteria extensive epidemiological studies are needed on each individual plant level. In this way contamination routes can be identified and appropriate measurements taken. A legally reglemented pasteurization process eliminates Enterobacteriaceae. Therefore recontamination must now be focussed on. PIF contaminated with Cronobacter spp. can lead to severe infections in neonates such a sepsis, meningitis or necrotizing enterocolitis. The reported prevalence of commercially available PIF appears to be gradually decreasing from estimates of 14% in 1988 to 2.0-2.5%, where it now seems to have become stabilized. In order to make a reasonable estimate concerning the prevalence of Cronobacter spp. on an individual plant level, 950 samples (raw material, finished products, environmental samples) were analysed. The high prevalence of 16% comes from the intentional sampling of critical raw material and environment samples. The PFGE analysis, however, did not reveal any correlation between raw material and environmental samples which would indicate a possible contamination via finished products. 470 PIF Enterobacteriaceae isolates were identified through biochemical tests as well as by rpoB sequencing. E. cloacae (35%), Pantoea spp. (11%) and K. pneumoniae (8%) were the most prevalent genus and species. In order to reveal possible contamination routes, a subtyping was conducted. The species E. cloacae, which can be found in the same niches as Cronobacter spp., could be used as a significant hygienic indicator organism. To complete the epidemiological picture, 363 milk based samples were analysed (raw milk, milk concentrate, milk powder). Raw milk contains Enterobacteriaceae but no Cronobacter spp. were detected. However, 12/172 samples of milk powder contained Cronobacter spp. due to recontamination (during the packaging process and/or further processing steps). In order to increase the sensitivity and specificity of today’s available analysis for the detection of Cronobacter spp. methodological improvements had to be undertaken. The currently used enrichment media (mLST, EE) contain components of too selective nature which can therefore lead to false negative results. The new “Cronobacter Screening Broth” (CSB) contains sucrose and 5-bromo-4-chloro-3-indolyl-α-D-Glucopyranoside which now leads to a sensitivity of 100% and a negative predicting value of 100% as well. The change in colour of the broth indicates a presumptively positive result whereby only these samples need to be streaked onto chromogenic agar. The visual intermediate result leads to a reduction in costs and working time. In order to increase specificity as well as the commercial pressure of fast product release, a PCR-based system where positive and negative results are clearly available in short time is recommended. Several real-time PCR based systems for detection of Cronobacter spp. have become commercially available. Two systems (one open platform (Biotecon Diagnostics, Potsdam, Germany) and one dedicated system (BioControl, Bellvue, USA)) generated neither false positive nor false negative results. Both systems were able to detect 9 target and 13 non-target strains. The dedicated system has the advantage of shorter hands-on and analysis time. In addition, contaminations due to handling faults are reduced. The existing rpoB based Cronobacter species PCR was upgraded for the recently described species C. condimenti which can now be detected with high reliability. Additional epidemiological data is needed in order to monitor the microbiological situation in industrial plants constantly as well as consequently. Based on information on individual plant level it is possible to implement adequate measurements such as HEPA filters, exact time for adding heat labile ingredients, personal and material flow, air management and cleaning (type, time). Scientific support is needed concerning adequate analytical methods, formation of biofilm, desiccation data, types of enrichment media, sample size as well as additional epidemiological data. Our recent study concerning genetic diversity showed that different Cronobacter isolates from one sample can contain different PFGE fingerprints. This observation suggests that analysis of one isolate per sample may not be sufficient for trace back studies. The analysis of at least five colony forming units per sample is suggested. This example shows that through a close collaboration between industrial companies and scientific institutes, knowledge can be actively turned into practice. – This helps prevent pre-term babies and newborns from falling ill to Cronobacter spp

Design Makes a Difference

There is more behind a pretty product than appearance: consumer safety, ease of use, production efficiency, and competitive marketing are essential ingredients in today\u27s industrial design process

The Netherlands in global corruption

The Netherlands in global corruptio

Observations écologiques sur le Néotrague de Bates ( Neotragus Batesi de Winton, 1903, artiodactyle, ruminant, bovide) du nord-est du Gabon

Bates’s Pygmy Antelope Neotragus batesi was studied for 15 consecutive months in North East Gabon. Fourteen animals were individually marked and six of them (5 9 9 and 1 3) monitored by radio-tracking. During the same period, 128 specimens were col lected outside the study area, to examine the stages of growth of their jugal teeth, tooth wear and reproductive condition. Four age-categories can be recognized among young animals, and five among adults. In the mature rain forest Neotragus batesi is commonly found in tree falls and along riversides. It thrives in secondary growth vegetation and native plantations where it reaches its highest population densities. Both its morphology and habits are well adapted to locomotion through dense undergrowth. Bates’s Pigmy Antelope is active by day as well as by night, with peaks in the morning and the evening. It rests in the middle of the day, and in the beginning and middle of the night. The home ranges are small (1 to 3 ha for females ; 2 to 4 ha for males). This area is not used evenly throughout the year ; the core-area of the range changes in keeping with the seasons. Fur thermore, every home range includes areas which are used only by day and others which are visited only by night, vegetation struc ture differing accordingly. The more regularly tended native plantations are those which produce the most food for Neotragus batesi, but periodical clearing of the undergrowth also disturbs the animals. Bates’s Pygmy Antelope has therefore to make use of both well managed native plantations and neglected ones or secondary growth to ensure its food supply and shelter. About 200 species of plants are eaten by Neotragus batesi in N.F. Gabon. Usually this pigmy antelope makes use of a given area when its plant food is most readily available, thus quickly adapting to new situations. Some of the most actively sought plant species, however, may definitely be scarce. On the whole this animal tends to browse upon the most nutritious parts of the plants it selects. Bates’s Pigmy Antelope is a solitary animal ; 76 % of the individuals encountered were alone. More than one female can share a single home range, whereas males never do so. Interindividual communication is mostly achieved through short groans (between a young animal and its mother, or between adult males and females), and through olfactory marking by the secretion of males’ anteorbital glands. Females do not display any territorial behaviour, whereas males might do so. Males are apparently polygamous, their large home ranges overlapping those of several females. Females give birth throughout the year, with peaks at the end of each of the two rainy seasons. In this way the young animals are weaned at a time when fresh grass is readily available. Mortality rate among males apparently increases at the M2 stage, when the young leave their mothers’ ranges, and also among the oldest adults. Among females mortality seems to be the highest amongst subadults, at the onset of the reproductive period. Females, as usual, outlive males. Competition with sympatric ungulates is avoided by diffe rences in size, a protracted activity rythm, and a strictly folivorous diet

Seasonal variation of activity in an assemblage of necrophagous beetles (Coleoptera, Scarabaeidae) in tropical rain forest

Temporal variations of the diversity and abundance of necrophagous forest Scarabaeidae were studied near the Petit Saut dam (French Guiana). A total of 4 370 individuals comprising 50 species were sampled with baited traps during a complete annual cycle in two sites 25 km apart. The total species richness, the diversity index and the equitability were greater on BPS site than on Pk3 site. The species compositions of the two sites were similar but the abundance distributions were clearly different. The estimated species richness based on Clench model was calculated on two-month periods. The species richness variations in Pk3 were poorly marked with a maximum in September-October. They were clearly bimodal in BPS with maxima in March-April and SeptemberLes variations temporelles de la diversité et de l'abondance des Scarabaeidae nécrophages forestiers ont été étudiées à proximité du barrage de Petit Saut (Guyane française). Un total de 4 370 individus comprenant 50 espèces a été collecté par piège appâté durant un cycle annuel complet sur deux sites éloignés de 25 km. La richesse spécifique totale, l'indice de diversité et la régularité ont été plus élevés sur le site BPS que sur le site Pk3. Les compositions spécifiques des deux sites sont proches mais les distributions d'abondance sont clairement différentes. L'estimation de la richesse spécifique sur des périodes de deux mois a été obtenue d'après le modèle de Clench. Les variations de richesse spécifique sont peu accentuées en Pk3 avec un maximum en septembre-octobre. Elles sont clairement bimodales en BPS avec des maxima en mars-avril et septembre-octobre. Aucune corrélation n'a été trouvée entre la richesse spécifique et la pluviométrie sur les deux sites. Une AFC effectuée sur les abondances des 14 espèces les plus abondantes du site Pk3 a permis d'opposer les mois les plus secs au début des pluies. En BPS les mois les plus secs ont été opposés à la fin et au début de la saison pluvieuse. Des groupes d'espèces ont pu être différenciés par un pic d'abondance en saison sèche, en début ou en fin de saison pluvieuse ou par leur absence ou leur rareté en saison sèche. Les différences de patron de variation globale de diversité et d'abondance d'espèces communes aux deux sites sont supposées être liées à des différences de structure de la végétation

Modifications of the rainforest frugivore community are associated with reduced seed removal at the community level

International audienceTropical rainforests worldwide are under increasing pressure from human activities, which are altering key ecosystem processes such as plant-animal interactions. However, while the direct impact of anthropogenic disturbance on animal communities has been well studied, the consequences of such defaunation for mutualistic interactions such as seed dispersal remains chiefly understood at the plant species level. We asked whether communities of endozoochorous tree species had altered seed removal in forests affected by hunting and logging and if this could be related to modifications of the frugivore community. At two contrasting forest sites in French Guiana, Nouragues (protected) and Montagne de Kaw (hunted and partly logged), we focused on four families of animal-dispersed trees (Sapotaceae, Myristicaceae, Burseraceae and Fabaceae) which represent 88 % of all endozoochorous trees which were fruiting at the time and location of the study. We assessed the abundance of the seed dispersers and predators of these four focal families by conducting diurnal distance sampling along line transects. Densities of several key seed dispersers such as large-bodied primates were greatly reduced at Montagne de Kaw, where the specialist frugivore Ateles paniscus is probably extinct. In parallel, we estimated seed removal rates from fruit and seed counts conducted in one-square-meter quadrats placed on the ground beneath fruiting trees. Seed removal rates dropped from 77 % at Nouragues to 47 % at Montagne de Kaw, confirming that the loss of frugivores associated with human disturbance impacts seed removal at the community level. In contrast to Sapotaceae, whose seeds are dispersed by mammals only, weaker declines in seed removal for Burseraceae and Myristicaceae suggest that some compensation may occur for these bird- and mammal-dispersed families, possibly because of the high abundance of toucans at the disturbed site. The defaunation process currently occurring across many tropical forests could dramatically reduce the diversity of entire communities of animal-dispersed trees through seed removal limitation

Effets de la fragmentation forestière sur l'activité des coléoptères coprophages : dispersion secondaire des graines en Guyane française

The effect of seed burial by dung beetles on seed survival and seedling establishment in Tetragastris altissima (Burseraceae) was measured on 3 sites of continuous forest and 7 islands in the man-inundated rain forest of Saint-Eugène, French Guiana. Experiments using a total of 250 seeds were performed using wire enclosures open to dung beetles but excluding terrestrial seed predators. Fragmentation had no effect on the rate of dung disappearance at 12, 24 and 48 h because there was a high variability between sites. On average, 24 % of seeds were buried by dung beetles after 72 h. Overall, there was no effect of fragmentation due to variation between sites. Dung burial rates were positively correlated with rarefaction of the dung beetle samples collected on the different sites. They were also positively correlated with weighted abundances of large diurnal tunneliers after 12 h and to total tunneliers after 24 h. Seed burial was positively correlated to weighted abundance of large noctumal tunneliers and of total tunneliers. The species diversity and abundance were positively related to area that did not involve a correlation between seed burial rates and area. After 72 h, survival rate of protected seeds at ground surface was significantly larger (78 %) than for non protected seeds (22 %), which were attacked by rodents. There was no difference between continuous forest and islands. Eight percent of buried seeds emerged, i.e. 2 % of all seeds deposited. Burial depth significantly affected the rate of emergence of buried seeds. Ninety percent of seeds at surface gerrninated versus 0 % at 10 and 15 cm. The effects of seed burial by dung beetles on early recruitment of T. altissima was low and highly variable between sites in relation with the structure of the community of Scarabaeidae and intensity of seed predationL'effet de l'enfouissement des graines contenues dans les excréments par les coléoptères coprophages sur la survie des graines et l'établissement des plantules a été mesuré chez Tetragastris altissima (Burseracées) sur 3 sites en forêt continue et 7 îles résultant de l'inondation de la forêt dense par l'homme à Saint-Eugène en Guyane française. Des expériences utilisant un total de 250 graines ont été menées avec un dispositif fait d'enclos laissant agir les coléoptères coprophages à l'abri des prédateurs terrestres de graines. Il n'a pas été détecté d'effet de la fragmentation sur les taux de disparition des excréments après 12, 24 et 48 h en raison de la grande variabilité entre sites. Un pourcentage moyen de 24 % des graines a été enfoui par les coprophages après 72 h. La fragmentation n'a pas eu d'effet sur l'enfouissement des graines qui a montré une grande variabilité entre sites. La disparition des excréments était positivement corrélée à la raréfaction des échantillons de coprophages capturés sur les sites, à l'abondance pondérée des grands fouisseurs diurnes après 1 2 h et avec celle du total des fouisseurs après 24 h. L'enfouissement des graines a été positivement corrélé aux abondances pondérées des grands fouisseurs nocturnes et du total des grands fouisseurs. La diversité spécifique et l'abondance des coprophages était positivement corrélée à la superficie des sites mais il n'y avait aucune corrélation entre l'enfouissement des excréments ou des graines et la superficie. Après 72 h, le taux de survie des graines protégées en surface (78 %) a été significativement supérieur à celui des graines non protégées (22 %), soumises à la prédation des rongeurs. Il n'a pas été observé de différences de survie entre la terre ferme et les îles. Huit pour cent des graines enfouies protégées ont émergé, soit 2 % de l'effectif initial. Le taux d'émergence des graines enfouies est significativement affecté par la profondeur. Il a été de 90 % en surface mais il a été nul à 10 et 15 cm de profondeur. L'effet des coprophages sur le succès de la régénération précoce de T. altissima a été faible et a varié selon les sites en relation avec la structure de la communauté de Scarabéidés et l'intensité de la prédation des graines au so