[Deep-sea research ground for the study of living matter properties in extreme conditions].

The Black Sea hollow bottom is a promising research ground in the field of deep-sea radiochemoecology and exobiology. It has turned out to be at the intersection of the earth and cosmic scientific interests such as deep-sea marine radiochemoecology from the perspective of the study of extreme biogeocenological properties of the Earth biosphere and exobiology from the standpoint of the study of life phenomena (living matter) outside the Earth biosphere, i.e. on other planets and during hypothetical transfer of spores in the outer space. The potential of this ground is substantiated with the data published by the author and co-workers on accumulation of 90Sr, 137Cs and Pu isotopes with silts of bathyal pelo-contour, on the quality of deep-sea hydrogen sulphide waters (after their contact with air) for vital functions of planktonic and benthic aerobes, as well as the species composition of marine, freshwater and terrestrial plants grown from the spores collected from the bottom sediments of the Black Sea bathyal. Discussion was based on V.I. Vernadsky's ideas about the living matter and biosphere, which allowed conclusions about the biospheric and outer space role of the described phenomena.

Pulsed xenon ultraviolet and non-thermal atmospheric plasma treatments are effective for the disinfection of air in hospital blood sampling rooms.

BACKGROUND AND OBJECTIVES: Non-thermal atmospheric plasma treatment and pulsed xenon ultraviolet (PX-UV) treatment are widely used in disinfection of hospital environments. However, their effectiveness has not been evaluated against a comparator. The objective of this study is to evaluate their effectiveness in the disinfection of pathogens in the air in hospital blood sampling rooms. METHODS: Samples were taken from the air before and after disinfection with PX-UV and non-thermal atmospheric plasma. We counted bacterial colonies and identified the types of bacteria. RESULTS: Non-thermal plasma treatment significantly reduced bacterial counts in the air, the median reduced from 1 before treatment to zero afterwards (p = 0.03). PX-UV treatment also significantly reduced bacterial counts in the air (p = 0.01), the median reduced from 1.5 before treatment to zero afterwards. Pathogens identified in the current study include nosocomial bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, and yeast. CONCLUSION: Disinfection of blood sampling sites is essential in a health service department. The efficiency of PX-UV and non-thermal atmospheric plasma treatment are comparable in air disinfection.

Seasonal dynamics of aerobic anoxygenic phototrophs in freshwater lake Vlkov.

Aerobic anoxygenic phototrophic (AAP) bacteria are a common component of freshwater microbial communities. They harvest light energy using bacteriochlorophyll a-containing reaction centers to supplement their predominantly heterotrophic metabolism. We used epifluorescence microscopy, HPLC, and infrared fluorometry to examine the dynamics of AAP bacteria in the mesotrophic lake Vlkov during the seasonal cycle. The mortality of AAP bacteria was estimated from diel changes of bacteriochlorophyll a fluorescence. The AAP abundance correlated with water temperature and DOC concentration. Its maximum was registered during late summer, when AAP bacteria made up 20% of total bacteria. The novel element of this study is the seasonal measurements of AAP mortality rates. The rates ranged between 1.15 and 4.56 per day with the maxima registered in early summer coinciding with the peak of primary production, which documents that AAP bacteria are a highly active component of freshwater microbial loop.

Comparative effectiveness of rapid-cycle ultraviolet decontamination to chemical decontamination on high-touch communication devices.

BACKGROUND: This quantitative, comparative-descriptive study of inpatient units in a large military medical center was designed to compare the effectiveness of compact ultraviolet (UV-C) decontamination to standard chemical decontamination in reducing the microbial burden on Vocera (San Jose, CA) communication devices and to characterize changes in staff cleaning practices following UV-C device implementation. METHODS: Aerobic and anaerobic swabs were used to collect microbial samples from Vocera devices (n = 60) before and after chemical decontamination (first sampling) and before and after UV decontamination (second sampling). Cleaning behaviors were assessed by observation and oral inquiry during the baseline sampling and surveyed 8 weeks after UV-C device implementation. Outcomes included aerobic and anaerobic colony-forming units and prevalence of methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, or Clostridium difficile, as determined by standard microbiological methods. RESULTS: No differences were found between the two cleaning methods in their ability to reduce aerobic bacteria; however, UV-C was significantly more effective at reducing bacteria grown anaerobically (P < .01). This study elucidated an 8.3% prevalence of methicillin-resistant Staphylococcus aureus on Vocera devices in the inpatient environment. Initially, 42% of respondents reported deviations from manufacturer's cleaning guidelines, and 16.7% reported daily or more frequent cleaning of the Vocera devices. CONCLUSIONS: After implementation, UV-C decontamination reduced average cleaning time by 43% and increased the rate of daily Vocera cleaning to 86.5%. Respondents reported an overall 98% user satisfaction with the UV-C device.

Natural sunlight induced rapid formation of water-born algal-bacterial granules in an aerobic bacterial granular photo-sequencing batch reactor.

Wastewater treatment by means of algal-bacterial granules has become a hot topic worldwide recently. Rapid granulation of algal-bacterial granules was achieved in an aerobic bacterial granular sequencing batch reactor (SBR) under natural sunlight exposure. Occurrence of abundant filamentous bacteria bridging the water-born algae, and overproduction of extracellular polymeric substances (EPS) (especially polysaccharides (PS), tryptophan & protein-like, and humic acid-like substances) were observed on the first 3 days, while the algae grew into the inner side of the granules and mature granules were obtained on day 7. The growth of the water-born algae slightly decreased the settleability, mean sizes of the granules, but stimulated the bioactivity significantly. Whereas, the biomass retention decreased before day 3, and got stable soon with the maturation period with symbiotic growth of algal-bacterial biomass. Illumina results revealed that the introduction of algae reduced the richness and diversity of bacterial community. Besides, few changes in structure and some compositions shifts in bacterial communities were found, while the predominant algae shifted from Diatomea to green algae Chlorophyceae. The possible mechanism for natural sunlight induced granulation of algal-bacterial granules was thus proposed based on the interactions between algae and bacteria.

Effect of pulsed xenon ultraviolet room disinfection devices on microbial counts for methicillin-resistant Staphylococcus aureus and aerobic bacterial colonies.

BACKGROUND: Inadequate environmental disinfection represents a serious risk for health care-associated infections. Technologic advancements in disinfection practices, including no-touch devices, offer significant promise to improve infection control. We evaluated one such device, portable pulsed xenon ultraviolet (PX-UV) units, on microbial burden during an implementation trial across 4 Veterans Affairs hospitals. METHODS: Environmental samples were collected before and after terminal room cleaning: 2 facilities incorporated PX-UV disinfection into their cleaning protocols and 2 practiced manual disinfection only. Specimens from 5 high-touch surfaces were collected from rooms harboring methicillin-resistant Staphylococcus aureus (MRSA) or aerobic bacteria colonies (ABC). Unadjusted pre-post count reductions and negative binomial regression modeled PX-UV versus manual cleaning alone. RESULTS: Seventy samples were collected. Overall, PX-UV reduced MRSA and ABC counts by 75.3% and 84.1%, respectively, versus only 25%-30% at control sites. Adjusting for baseline counts, manually cleaned rooms had significantly higher residual levels than PX-UV sites. Combined analyses revealed an incident rate ratio of 5.32 (P = .0024), with bedrails, tray tables, and toilet handrails also showing statistically superior PX-UV disinfection. CONCLUSIONS: This multicenter study demonstrates significantly reduced disinfection across several common pathogens in facilities using PX-UV devices. Clinical impact of laboratory reductions on infection rates was not assessed, representing a critical future research question. However, such approaches to routine cleaning suggest a practical strategy when integrated into daily hospital operations.

Impact of microparticles on UV disinfection of indigenous aerobic spores.

Numerous studies have shown that the efficacy of ultraviolet (UV) disinfection can be hindered by the presence of particles that can shield microorganisms. The main objective of this study was to determine to what extent natural particulate matter can shield indigenous spores of aerobic spore-forming bacteria (ASFB) from UV rays. The extent of the protective shielding was assessed by comparing the inactivation rates in three water fractions (untreated, dispersed and filtered on an 8 microm membrane) using a collimated beam apparatus with a low-pressure lamp emitting at 254 nm. Levels of inactivation were then related to the distribution and abundance of particles as measured by microflow imaging. Disinfection assays were completed on two source waters of different quality and particle content. A protocol was developed to break down particles and disperse aggregates (addition of 100mg/L of Zwittergent 3-12 and blending at 8000 rpm for 4 min). Particle size distribution (PSD) analysis confirmed a statistically significant decrease in the number of particles for diameter ranges above 5 microm following the dispersion protocol and 8 microm filtration. The fluence required to reach 1-log inactivation of ASFB spores was independent of particle concentration, while that required to reach 2-log inactivation or more was correlated with the concentration of particles larger than 8 microm (R(2)>0.61). Results suggest that natural particulate matter can protect indigenous organisms from UV radiation in waters with elevated particle content, while source water with low particle counts may not be subject to this interference.

Light enhances the growth rates of natural populations of aerobic anoxygenic phototrophic bacteria.

Aerobic anoxygenic phototrophic (AAP) bacteria are microorganisms that can harvest light energy using bacteriochlorophyll a to supplement their predominantly organotrophic metabolism. Growth enhancement by light has repeatedly been demonstrated in laboratory experiments with AAP isolates. However, the ecological advantage of light utilization is unclear, as it has never been proven in the natural environment. Here, we conducted manipulation experiments in the NW Mediterranean and found that AAP bacteria display high growth rates which are controlled to a large extent by intense grazing pressure and phosphorous availability. Foremost, we found that, contrarily to the bulk bacterioplakton, AAP bacteria display higher growth rates when incubated under light-dark cycles than in complete darkness. These results represent the first direct evidence that natural populations of marine AAP bacteria can be stimulated by light.

E-Beam Irradiation for Improving the Microbiological Quality of Smoked Duck Meat with Minimum Effects on Physicochemical Properties During Storage.

This study was performed to evaluate the effect of different doses (0, 1.5, 3, and 4.5 kGy) of e-beam irradiation on the quality parameters (pH, Hunter's parameter, and heme pigment) and stability qualifiers (peroxide value [POV], thiobarbituric acid reactive substances [TBARSs], and total volatile basic nitrogen [TVBN]) of smoked duck meat during 40 d of storage under vacuum packaging at 4 °C. The initial populations of total bacteria (7.81 log CFU/g) and coliforms (5.68 log CFU/g) were reduced by approximately 2 to 5 log cycles with respect to irradiation doses. The results showed that pH, myoglobin, met-myoglobin, L* , a* , and b* showed significant differences with respect to different doses and storage intervals; a* and b* did not vary significantly because of storage. Higher pH was found in samples treated with 4.5 kGy at 40 d, while the minimum was observed in nonirradiated samples at day 0 of storage. Higher POV (2.31 ± 0.03 meq peroxide/kg) and TBARS (5.24 ± 0.03 mg MDA/kg) values were found in 4.5 kGy-treated smoked meat at 40 d and the lowest was reported in 0 kGy-treated meat at initiation of storage (0 d). However, irradiation suppressed TVBN during storage and higher TVBN (7.09 ± 0.32 mg/100 mL) was found in duck meat treated with 0 kGy at 40 d. The electronic nose (e-nose) effectively distinguished flavor profiles during the different storage intervals. The results showed that different sensory attributes did not vary significantly with respect to the dose of irradiation. We conclude that low dose of e-beam irradiation and vacuum packaging is beneficial for safety and shelf life extension without affecting the sensory characteristics of smoked duck meat.

Single-cell activity of freshwater aerobic anoxygenic phototrophic bacteria and their contribution to biomass production.

Aerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophs that despite their low abundances have been hypothesized to play an ecologically and biogeochemically important role in aquatic systems. Characterizing this role requires a better understanding of the in situ dynamics and activity of AAP bacteria. Here we provide the first assessment of the single-cell activity of freshwater AAP bacteria and their contribution to total bacterial production across lakes spanning a wide trophic gradient, and explore the role of light in regulating AAP activity. The proportion of cells that were active in leucine incorporation and the level of activity per cell were consistently higher for AAP than for bulk bacteria across lakes. As a result, AAP bacteria contributed disproportionately more to total bacterial production than to total bacterial abundance. Interestingly, although environmentally driven patterns in activity did not seem to differ largely between AAP and bulk bacteria, their response to light did, and exposure to light resulted in increases in the proportion of active AAP bacteria with no clear effect on their cell-specific activity. This suggests that light may play a role in the activation of AAP bacteria, enabling these photoheterotrophs to contribute more to the carbon cycle than suggested by their abundance.

Effect of chlorine, sodium chloride, trisodium phosphate, and ultraviolet radiation on the reduction of Yersinia enterocolitica and mesophilic aerobic bacteria from eggshell surface.

Eggshell sanitizing practices are necessary to improve microbiological safety of fresh hen eggs and their products. In this work, the effects of 100 mg/liter free chlorine (chl), 3% sodium chloride (NaCl), 1, 5, and 12% trisodium phosphate (TSP) in wash solutions, and UVR (ultraviolet radiation; 4.573 microW/cm2) were studied at different times on uninoculated and Yersinia enterocolitica-inoculated eggs. On uninoculated eggs, the best results were obtained with 100 mg/liter chlorine and UV exposure for >25 min, with reductions of 1.28 and 1.60 log cycles, respectively, compared to the average bacterial count (4.55 log CFU/egg) on the control (untreated eggs). On Y. enterocolitica-inoculated eggs, highest reductions of the average bacterial count (7.35 log CFU/egg) were obtained with 5 and 12% TSP and 100 mg/liter chl. The decrease obtained with 12% TSP (3.74-log reduction) was significantly higher (P < 0.05) than those obtained with the remaining treatments. Y. enterocolitica was more resistant to UVR than the eggshell natural mesophilic aerobic microflora, except when low inoculum (4.39 log CFU/egg) was assayed. Changes in eggshell microstructure were measured by the blue lake staining method. The presence of Yersinia and Salmonella in eggshell natural flora was also investigated.

Microbial and sensory quality of marinated and irradiated chicken.

Chicken legs were subjected to two pretreatments (packaged in air or marinated in natural plant extracts and then packaged in air) followed by irradiation (0, 3, or 5 kGy). The control and irradiated chicken legs were stored at 4 degrees C and underwent microbial analysis (mesophilic aerobic plate counts and Salmonella detection) and sensory evaluation at predetermined intervals. Microbial analysis indicated that irradiation had a significant effect (P < or = 0.05) on the mesophilic aerobic plate counts of the poultry. For each treatment, the bacterial growth decreased with an increase of irradiation dose. The marinade had an additive effect with irradiation in reducing bacterial growth and controlling proliferation during storage at 4 +/- 1 degree C. No Salmonella was observed until day 12 in marinated chicken irradiated at 3 kGy and for all experiments with chicken legs stored under air or marinated at 5 kGy. However, Salmonella was found in chicken legs irradiated at 3 kGy in air and in nonirradiated samples. The sensory evaluation indicated a significant (P < or = 0.05) difference in odor and flavor intensities between the irradiated chicken at 5 kGy and the control. No significant difference was found (P > 0.05) between the marinated chicken irradiated at 5 kGy and the control.

Reduction of eggshell aerobic plate counts by ultraviolet irradiation.

The effects of 254 nm ultraviolet light (UV) radiation on aerobic plate count (APC) of egg shells were investigated. In the first experiment, eggs were exposed to UV treatment (7.35 mW/cm2) for 0, 15, 30, and 60 s. Three eggs from each treatment were aseptically collected and placed into sterile plastic bags containing 50 mL of sterile phosphate-buffered solution. Serial dilutions of the phosphate-buffered solution were plated on aerobic plate count agar and incubated at 37 C for 48 h. Exposure of eggshells to 30 and 60 s UV significantly reduced aerobic plate counts compared to untreated eggs. Exposure to 60 s of UV resulted in a 2 to 3 log10 cfu/egg APC reduction and reduced counts below detectable levels. In the second experiment, UV lights were placed in a chamber equipped with a commercial-style egg conveyor. A UV treatment of 7.5 mW/cm2 and time intervals of 0, 12, 36, and 48 s were used. Three eggs were placed consecutively on the conveyor and passed through the chamber. The center egg was selected for APC evaluation. Sample size, dilution, plating, and incubation procedures were used as described for the first experiment. A significant 1 to 2 log10 reduction in colony-forming units per egg between the eggs treated 48 s to the untreated eggs was detected. The results of these studies show that UV light treatment at high intensities and low time intervals has the potential to reduce aerobic plate counts of eggshells.

Evaluation of a method of ultraviolet light sanitation of broiler hatching eggs.

Sanitation of hatching eggs is an important area of research due to the need for an effective, economical, and safe method of egg sanitation. Improved hatching egg sanitation is an important part of an overall pathogen reduction program within integrated poultry operations. This must be accomplished without disturbing the cuticle of the egg, which can decrease hatchability. The ability of ultraviolet (UV) light to kill bacteria on eggshell surfaces has been well documented. To accomplish the task of treating the eggs in a method that could be commercially implemented, a cabinet was constructed in which ultraviolet lamps were placed. A conveyor system was used to carry a plastic hatching egg flat containing 42 eggs through the cabinet for a period of 3 or 4 min. Ultraviolet intensities within the cabinet reached a maximum of 14 mW/cm2. Experiments were conducted to test the impact of UV light (254 nm) exposure of hatching eggs on aerobic plate counts (APC), inoculated Salmonella typhimurium and inoculated Escherchia coli. In the first three experiments, seven eggs were sampled from a flat passed through the UV chamber. Ultraviolet-treated eggs compared to untreated eggs had APC reductions of 1.3 log, S. typhimurium had a 4 log reduction, and E. coli had a 4 to 5 log reduction. Laboratory trials were also conducted to test the effects of UV irradiation on the cuticle of the egg and hatchability. No significant differences for eggshell conductance or hatchability were found between UV-treated and control eggs. From these trials, it can be concluded that UV irradiation of hatching eggs in a prototype irradiation cabinet can effectively reduce aerobic and pathogenic bacteria on eggshell surfaces without affecting eggshell conductance or hatchability.

Comparison of the effectiveness of several denture sanitizing systems: a clinical study.

The purpose of this clinical study was to test the effectiveness of three methods of decontamination on complete dentures. Dentures worn by patients for varying lengths of time were handled aseptically and treated with three different treatment modalities. The dentures were touched and sectioned and then retouched to a variety of microbiological media. The quantity of microbial growth was recorded and predominating microorganisms were identified using standard microbiological techniques. System A was found to consistently decontaminate and sanitize dentures worn by patients. System B and System C showed variable reduction of microorganisms. An unexpected spectrum of both pathogenic and opportunistic microorganisms was found in the dentures examined, including a wide range of gram-negative bacteria, gram-positive bacteria, and yeasts. A wide range of microorganisms must be considered when treating either oral or systemic diseases in denture wearers. Denture hygiene and decontamination are critical to the prevention of oral and systemic disease transmission. The dentures of ill patients must be considered as possible sources of pathogenic microorganisms.

Irradiation of diets fed to captive exotic felids: microbial destruction, consumption, and fecal consistency.

Two frozen, raw horse meat-based diets fed to captive exotic felids at Brookfield Zoo were irradiated to determine the extent of microbial destruction and whether radiation treatment would affect consumption and/or fecal consistency in exotic cats. Fifteen cats, two African lions (Panthera leo), two Amur tigers (Panthera tigris altaica), one Amur leopard (Panthera pardus orientalis), two clouded leopards (Neofelis nebulosa), two caracals (Felis caracal), one bobcat (Felis rufus), and five fishing cats (Felis viverrinus), housed at Brookfield Zoo were fed nonirradiated and irradiated raw diets containing horse meat with cereal products and fortified with nutrients: Nebraska Brand Feline and/or Canine Diet (Animal Spectrum, North Platte, Nebraska 69103, USA). Baseline data were obtained during a 2-wk control period (nonirradiated diets), which was followed by a 4-wk period of feeding comparable irradiated diets. Feed intake and fecal consistency data were collected. An estimated radiation dose range of 0.5-3.9 kilograys reduced most microbial populations, depending on specific diet and microbe type. Irradiation had no overall effect on either feed consumption or fecal consistency in captive exotic cats, regardless of species, age, sex, or body mass. Data indicate that irradiation of frozen horse meat-based diets (packaged in 2.2-kg portions) result in microbial destruction in these products but that product storage time between irradiation and sampling may also affect microbial reduction. However, irradiation would be an appropriate method for reducing potentially pathologic bacteria in raw meat fed to exotic cats.

Effects of gamma ray and electron-beam irradiations on survival of anaerobic and facultatively anaerobic bacteria.

An extension of the approval for food irradiation is desired due to the increase in the incidence of food poisoning in the world. One anaerobic (Clostridium perfringens) and four facultatively anaerobic (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Enteritidis) bacteria irradiated with gamma ray or electron beam (E-beam) were tested in terms of survival on agar under packaging atmosphere. Using pouch pack, effects of two irradiations on survival of anaerobic and facultatively anaerobic bacteria were evaluated comparatively. E-beam irradiation was more effective than gamma ray irradiation in decreasing the D10 value of B. cereus at 4 degrees C, slightly more effective in that of E. coli O157, and similarly effective in that of the other three bacteria at 4 degrees C. The gamma irradiation of the bacteria without incubation at 4 degrees C before irradiation was more effective than that of the bacteria with incubation overnight at 4 degrees C before irradiation in decreasing the D10 values of these bacteria (B. cereus, E. coli O157, and L. monocytogenes). Furthermore, ground beef patties inoculated with bacteria were irradiated with 1 kGy by E-beam (5 MeV) at 4 degrees C. The inoculated bacteria in the 1-9 mm beef patties were killed by 1 kGy E-beam irradiation and some bacteria in more than 9 mm beef patties were not killed by the irradiation.

[Changes in the oral microflora under the influence of pulsed periodic CO2 laser radiation in operations on the jaw bones]. / Izmenenie mikroflory polosti rta pod vozdeistviem impul'sno-periodicheskogo CO2-lazernogo izlucheniia pri operatsiiakh na cheliustnykh kostiakh.

Effects of pulsed periodical laser exposure on oral microflora were studied. Bacterial growth was suppressed immediately after surgery if pulsed periodical CO2 laser was used. Later only quantitative changes in the bacterial composition were observed. Asepticism of laser radiation does not depend on the discreteness of laser beam, radiation frequency, pulse duration, but depended on the radiation power, exposure duration, and area of exposure.

Aerobic cervical bacteriology and antibiotic sensitivity patterns in patients with advanced cervical cancer before and after radiotherapy at a national referral hospital in Uganda.

OBJECTIVE: To determine prevalent aerobic cervical bacteria and sensitivity to commonly used antibiotics in patients with advanced cervical cancer before and after 4 weeks of external beam radiotherapy (EBRT). METHODS: Cervical swabs were collected prior to the initial radiation dose and after 4 weeks of radiotherapy at Mulago Hospital. Aerobic culture was performed on blood agar, chocolate agar, and MacConkey agar, and incubated at 35-37 ° for 24-48 hours. Isolates were identified using colonial morphology, Gram staining, and biochemical analysis. Sensitivity testing was performed via Kirby-Bauer disk diffusion and dilution. Differences in the proportions of bacteria isolated before and after radiotherapy were compared. Paired t test was used to obtain differences in sensitivity before and after radiotherapy. RESULTS: Normal flora increased significantly after EBRT (P=0.02). There was no significant change in overall proportion of positive cultures. Sensitivity to commonly used antibiotics improved (P=0.05) and resistance significantly decreased (P=0.005). Significant differences were seen mainly with ciprofloxacin, ceftriaxone, and gentamicin. CONCLUSION: Four weeks of EBRT did not sterilize the cervix but resulted in an increase in normal flora. Radiotherapy appeared to reduce resistance to commonly used antibiotics. Sensitivity to chloramphenicol was higher than for the more commonly used antibiotics.

Curcumin as a potential non-steroidal contraceptive with spermicidal and microbicidal properties.

OBJECTIVE: Curcumin, a component of the curry powder turmeric, has immense biological properties, including anticancer effects. The objective of this study was to determine if curcumin can provide a novel non-steroidal contraceptive having both spermicidal and microbicidal properties. STUDY DESIGN: The effect of curcumin, with and without photosensitization, was examined on human sperm forward motility and growth of several aerobic (n=8) and anaerobic bacteria (n=4) and yeast (n=7) strains implicated in vaginosis, vaginitis, and vaginal infections in women. The effect of various concentrations of curcumin on human sperm and microbes (aerobic and anaerobic bacteria and yeast) was tested. The effect on sperm was examined by counting the sperm forward motility, and on microbes by agar and broth dilutions and colony counting. Each experiment was repeated using different semen specimens, and bacteria and yeast stocks. RESULTS: Curcumin caused a concentration-dependent inhibition of sperm forward motility with a total block at ≥250µM concentration. After photosensitization, the effective concentration to completely block sperm forward motility decreased 25-fold, now requiring only 10µM concentration for total inhibition. Curcumin concentrations between 100 and 500µM completely blocked the growth of all the bacteria and yeast strains tested. After photosensitization, the effective concentration to completely inhibit microbial growth decreased 10-fold for aerobic bacteria and yeast, and 5-fold for anaerobic bacteria. CONCLUSIONS: These findings suggest that curcumin can block sperm function and bacteria/yeast growth. It can potentially provide an ideal non-steroidal contraceptive having both spermicidal and microbicidal properties against vaginal infections.