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Internal Contamination (internal + contamination)
Selected AbstractsBacterial Culture and DNA Checkerboard for the Detection of Internal Contamination in Dental ImplantsJOURNAL OF PROSTHODONTICS, Issue 5 2009Rodrigo Edson Santos Barbosa DDS Abstract Purpose: The aim of this in vitro study was to evaluate the bacterial leakage along the implant,abutment interface by the conventional bacterial culture and DNA Checkerboard hybridization method. Materials and Methods: Twenty Branemark-compatible implants with a 3.75-mm diameter and external hexagonal platform were randomly placed in two groups of ten implant,abutment assemblies each. One group was used to analyze bacterial counts by DNA Checkerboard hybridization and the other by a conventional bacterial culture. Suspensions of Fusobacterium nucleatum (3 ,l) were injected into the grooved internal cylinders of each implant assembly, and the abutment was connected by a 32 Ncm torque. The combined implant,abutments were individually placed in tubes containing the CaSaB culture medium and incubated in a bacteriological constant temperature oven for 14 days. The samples were observed daily as to the presence of turbidity, and after the designated time the microorganisms were collected from the implant interiors and analyzed by the two methods. Results: After 14 days, six implant,abutment assemblies showed turbidity. Both methods indicated reduced microorganism counts in samples from the interior of the implant,abutment assemblies after incubation in the culture medium; however, the number of counts of F. nucleatum was higher by the DNA Checkerboard method when compared to the group analyzed by conventional bacterial cultures (p < 0.05). Conclusion: The DNA Checkerboard method was shown to be more sensitive than conventional cultures in the detection of microorganisms. [source] Mechanisms of egg contamination by Salmonella EnteritidisFEMS MICROBIOLOGY REVIEWS, Issue 4 2009Inne Gantois Abstract Salmonella Enteritidis (SE) has been the major cause of the food-borne salmonellosis pandemic in humans over the last 20 years, during which contaminated hen's eggs were the most important vehicle of the infection. Eggs can be contaminated on the outer shell surface and internally. Internal contamination can be the result of penetration through the eggshell or by direct contamination of egg contents before oviposition, originating from infection of the reproductive organs. Once inside the egg, the bacteria need to cope with antimicrobial factors in the albumen and vitelline membrane before migration to the yolk can occur. It would seem that serotype Enteritidis has intrinsic characteristics that allow an epidemiological association with hen eggs that are still undefined. There are indications that SE survives the attacks with the help of antimicrobial molecules during the formation of the egg in the hen's oviduct and inside the egg. This appears to require a unique combination of genes encoding for improved cell wall protection and repairing cellular and molecular damage, among others. [source] Enumeration of Campylobacter spp. on the surface and within chicken breast filletsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2007P. Luber Abstract Aim:, To investigate how many Campylobacter bacteria are present on the surface and inside chicken breast fillets, with a focus on generating data distributions which can be used in risk assessments for this pathogen,commodity combination. Methods and Results:, We analysed 100 fresh retail chicken breast fillets (skinless and deboned) by means of a rinse sample for surface and 55 fillets for internal pathogen contamination using 10 g meat and a most probable number technique. Prevalence was 87% on the surface and 20% in the deep tissue. The mean number of Campylobacter on the surface of the fillets was 1903 CFU, with a median of 537 CFU and a maximum of 38 905 CFU. Campylobacter counts inside the tissue were <1 CFU g,1 meat (mean = 0·24 CFU, median = 0·15 CFU, maximum = 0·74 CFU). In addition, we investigated the influence of the type of package on the occurrence of the pathogen. Data provide an indication of less favourable conditions for survival of the pathogen on chicken meat packed under a modified atmosphere of carbon dioxide in nitrogen, in comparison with ambient air or vacuumed packages. Conclusions:, Given the high numbers of the pathogen on the chicken meat surface in comparison with low levels of internal contamination, it can be concluded that cross-contamination during the preparation of contaminated chicken is a more important pathway for consumers' exposure to Campylobacter than the consumption of undercooked meat. Significance and Impact of the Study:, The detailed quantitative data on the occurrence of C. jejuni and C. coli on the surface and inside chicken meat presented here can be useful for future probabilistic exposure assessments. [source] The effect of a commercial UV disinfection system on the bacterial load of shell eggsLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2006K. De Reu Abstract Aims:, To study the effect of UV irradiation on the bacterial load of shell eggs and of a roller conveyor belt. Methods and Results:, The natural bacterial load on the eggshell of clean eggs was significantly reduced by a standard UV treatment of 4·7 s; from 4·47 to 3·57 log CFU per eggshell. For very dirty eggs no significant reduction was observed. Eggs inoculated with Escherichia coli and Staphylococcus aureus (4·74 and 4·64 log CFU per eggshell respectively) passed the conveyor belt and were exposed to UV for 4·7 and 18·8 s. The reduction of both inoculated bacteria on the eggshell was comparable and significant for both exposure times (3 and 4 log CFU per eggshell). Escherichia coli was reduced but still detectable on the conveyor rollers. The internal bacterial contamination of eggs filled up with diluent containing E. coli or S. aureus was not influenced by UV irradiation. Conclusions:, There is a significant lethal effect of UV irradiation on the bacterial contamination of clean eggshells and recent shell contamination, contamination of rollers can be controlled and the internal contamination of eggs is not reduced. Significance and Impact of the Study:, The penetration of UV into organic material appears to be poor and UV disinfection can be used as an alternative for egg washing. [source] | ||||||||||