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1.
J Food Prot ; 84(8): 1366-1373, 2021 08 01.
Article in English | MEDLINE | ID: mdl-33852721

ABSTRACT

ABSTRACT: Survival and growth of Salmonella and Shiga toxin-producing Escherichia coli (STEC) were investigated in kombucha prepared from four brands of commercially available kombucha kits intended for use by home brewers. Changes in populations of the indigenous microbiota responsible for fermentation of kombucha were also determined. An initial population of Salmonella (6.77 log CFU/mL) decreased to below the detection limit (0.30 log CFU/mL) within 10 days in kombucha prepared from two of the test brands. Populations of 1.85 and 1.20 log CFU/mL were detected in two brands fermented for 14 days. An initial STEC population of 7.02 log CFU/mL decreased to <0.30 log CFU/mL in two brands within 14 days; 0.77 and 0.87 log CFU/mL were detected in kombucha prepared from the other two brands. Salmonella and STEC increased within 1 day in three brands of base tea used to prepare kombucha and were stable throughout 14 days of incubation. Both pathogens steadily declined in base tea prepared from one brand of kombucha kit. Inactivation of the pathogens occurred as the pH of the kombucha decreased, but a clear correlation between rates of inactivation among different brands of kits and decrease in pH was not evident. Growth and peak populations of mesophilic aerobic microorganisms, yeasts, lactic acid bacteria, and acetic acid bacteria varied depending on the kombucha kit brand. No strong evidence was found of a correlation between the behavior of Salmonella or STEC and that of any of these groups of indigenous microbiota. Results of this study show that survival of Salmonella and STEC in kombucha and base tea used to prepare kombucha is dependent on inherent differences in commercially available kombucha kits intended for use in home settings. Strict application of hygienic practices is essential for preventing contamination with Salmonella or STEC and reducing the risk of illness associated the consumption of kombucha.


Subject(s)
Microbiota , Shiga-Toxigenic Escherichia coli , Bacteria , Fermentation , Food Microbiology , Salmonella
2.
J Sci Food Agric ; 99(7): 3530-3537, 2019 May.
Article in English | MEDLINE | ID: mdl-30624787

ABSTRACT

BACKGROUND: Cabbage may become contaminated with enteric pathogens during cultivation. Using multiple cabbage cultivars at two maturity stages (small plants or plants with small heads) in growth chamber studies, the fate (internalization or surface survival) of Salmonella and Escherichia coli O157:H7 (0157) were examined in conjunction with any potential relationships to the plant's antimicrobial content. RESULTS: Internalized Salmonella was detected in cabbage within 24 h with prevalence ranging from 62% (16 of 26) for the 'Super Red 80' cultivar to 92% (24 of 26) for the 'Red Dynasty' cultivar. Surface survival of pathogens on small cabbage plants over nine days was significantly affected by cultivar with both pathogens surviving the most on the 'Farao' cultivar and Salmonella and O157 surviving the least on the 'Super Red 80' and 'Capture' cultivars, respectively (P < 0.05). Survival of O157 was slightly higher on cabbage heads for O157 than small plants suggesting that the maturity stage may affect this pathogen's fate. An inverse relationship existed between antimicrobial levels and the pathogen's surface survival on cabbage heads (P < 0.05). CONCLUSIONS: The fate of pathogens varied with the cabbage cultivar in growth chamber studies highlighting the potential to explore cultivar in field studies to reduce the risk of microbiological contamination in this crop. © 2019 Society of Chemical Industry.


Subject(s)
Brassica/microbiology , Escherichia coli O157/growth & development , Salmonella/growth & development , Brassica/growth & development , Colony Count, Microbial , Food Contamination/analysis , Microbial Viability
3.
Exp Parasitol ; 184: 121-127, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29274312

ABSTRACT

Cyclospora cayetanensis is an emerging pathogen that is endemic in developing countries and responsible for many large foodborne cyclosporiasis outbreaks in North America since 1990s. Because of the lack of typing targets, the genetic diversity and population genetics of C. cayetanensis have not been investigated. In this study, we undertook a population genetic analysis of multilocus sequence typing data we recently collected from 64 C. cayetanensis specimens. Despite the extensive genetic heterogeneity in the overall C. cayetanensis population, there were significant intra- and inter-genic linkage disequilibria (LD). A disappearance of LD was observed when only multilocus genotypes were included in the population genetic analysis, indicative of an epidemic nature of C. cayetanensis. Geographical segregation-associated sub-structuring was observed between specimens from China and those from Peru and the United States. The two subpopulations had reduced LD, indicating the likely occurrence of genetic exchange among isolates in endemic areas. Further analyses of specimens from other geographical regions are necessary to fully understand the population genetics of C. cayetanensis.


Subject(s)
Cyclospora/genetics , Genetics, Population , Alleles , China , Cyclospora/classification , Cyclosporiasis/parasitology , Genetic Variation , Humans , Multilocus Sequence Typing , Nepal , Peru , Polymorphism, Genetic , Spain , United States
4.
J Food Prot ; 80(9): 1408-1414, 2017 09.
Article in English | MEDLINE | ID: mdl-28741960

ABSTRACT

Outbreaks of salmonellosis have been associated with consumption of high-sugar, low-water activity (aw) foods. The study reported here was focused on determining the effect of storage temperature (5 and 25°C) on survival of initially high and low levels of Salmonella in dry-inoculated sucrose (aw 0.26 ± 0.01 to 0.54 ± 0.01) and wet-inoculated sucrose (aw 0.24 ± 0.01 to 0.44 ± 0.04) over a 52-week period. With the exception of dry-inoculated sucrose at aw 0.26, Salmonella survived for 52 weeks in dry- and wet-inoculated sucrose stored at 5 and 25°C. Retention of viability was clearly favored in sucrose stored at 5°C compared with 25°C, regardless of level or type of inoculum or aw. Survival at 5°C was not affected by aw. Initial high-inoculum counts of 5.18 and 5.25 log CFU/g of dry-inoculated sucrose (aw 0.26 and 0.54, respectively) stored for 52 weeks at 5°C decreased by 0.56 and 0.53 log CFU/g; counts decreased by >4.18 and >4.25 log CFU/g in samples stored at 25°C. Inactivation rates in wet-inoculated sucrose were similar to those in dry-inoculated sucrose; however, a trend toward higher persistence of Salmonella in dry- versus wet-inoculated sucrose suggests there was a higher proportion of cells in the wet inoculum with low tolerance to osmotic stress. Survival patterns were similar in sucrose initially containing a low level of Salmonella (2.26 to 2.91 log CFU/g). The pathogen was recovered from low-inoculated sucrose stored at 5°C for 52 weeks regardless of type of inoculum or aw and from dry-inoculated sucrose (aw 0.54) and wet-inoculated sucrose (aw 0.24) stored at 25°C for 12 and 26 weeks, respectively. Results emphasize the importance of preventing contamination of sucrose intended for use as an ingredient in foods not subjected to a treatment that would be lethal to Salmonella.


Subject(s)
Food Handling/methods , Microbial Viability , Salmonella/growth & development , Sucrose , Colony Count, Microbial , Food Microbiology , Temperature , Water
5.
PLoS Negl Trop Dis ; 10(2): e0004396, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26863440

ABSTRACT

BACKGROUND: The transitional period between the oncosphere and the cysticercus of Taenia solium is the postoncospheral (PO) form, which has not yet been completely characterized. The aim of this work was to standardize a method to obtain T. solium PO forms by in vitro cultivation. We studied the morphology of the PO form and compared the expression of antigenic proteins among the PO form, oncosphere, and cysticerci stages. METHODOLOGY/PRINCIPAL FINDINGS: T. solium activated oncospheres were co-cultured with ten cell lines to obtain PO forms, which we studied at three stages of development--days 15, 30, and 60. A high percentage (32%) of PO forms was obtained using HCT-8 cells in comparison to the other cell lines. The morphology was observed by bright field, scanning, and transmission electron microscopy. Morphology of the PO form changed over time, with the six hooks commonly seen in the oncosphere stage disappearing in the PO forms, and vesicles and microtriches observed in the tegument. The PO forms grew as they aged, reaching a diameter of 2.5 mm at 60 days of culture. 15-30 day PO forms developed into mature cysticerci when inoculated into rats. Antigenic proteins expressed in the PO forms are also expressed by the oncosphere and cysticerci stages, with more cysticerci antigenic proteins expressed as the PO forms ages. CONCLUSIONS/SIGNIFICANCE: This is the first report of an in vitro production method of T. solium PO forms. The changes observed in protein expression may be useful in identifying new targets for vaccine development. In vitro culture of PO form will aid in understanding the host-parasite relationship, since the structural changes of the developing PO forms may reflect the parasite's immunoprotective mechanisms. A wider application of this method could significantly reduce the use of animals, and thus the costs and time required for further experimental investigations.


Subject(s)
Antigens, Helminth/analysis , Taenia solium/anatomy & histology , Taenia solium/growth & development , Animals , Blotting, Western , Cell Line , Coculture Techniques , Gene Expression Profiling , Humans , Microscopy , Taenia solium/genetics
6.
Food Microbiol ; 52: 138-45, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26338127

ABSTRACT

Poor hygiene and improper food preparation practices in consumers' homes have previously been demonstrated as contributing to foodborne diseases. To address potential cross-contamination by kitchen utensils in the home, a series of studies was conducted to determine the extent to which the use of a knife or grater on fresh produce would lead to the utensil's contamination with Escherichia coli O157:H7 or Salmonella enterica. When shredding inoculated carrots (ca. 5.3 log CFU/carrot), all graters became contaminated and the number of E. coli O157:H7 present on the utensil was significantly greater than Salmonella (p < 0.05). Contamination of knives after slicing inoculated produce (4.9-5.4 log CFU/produce item) could only be detected by enrichment culture. After slicing tomatoes, honeydew melons, strawberries, cucumbers, and cantaloupes, the average prevalence of knife contamination by the two pathogens was 43%, 17%, 15%, 7%, and 3%, respectively. No significant increase in the incidence or level of contamination occurred on the utensils when residues were present (p > 0.05); however, subsequent contamination of 7 produce items processed with the contaminated utensils did occur. These results highlight the necessity of proper sanitization of these utensils when used in preparation of raw produce.


Subject(s)
Equipment Contamination , Escherichia coli O157/growth & development , Food Contamination/analysis , Food Handling/instrumentation , Foodborne Diseases/microbiology , Salmonella enterica/growth & development , Consumer Product Safety , Cooking and Eating Utensils , Escherichia coli O157/isolation & purification , Food Handling/methods , Fruit/microbiology , Humans , Salmonella enterica/isolation & purification , Vegetables/microbiology
7.
J Food Prot ; 78(9): 1624-31, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26319715

ABSTRACT

Consumers are being advised to increase their consumption of fruits and vegetables to reduce their risk of chronic disease. However, to achieve that goal, consumers must be able to implement protocols in their kitchens to reduce their risk of consuming contaminated produce. To address this issue, a study was conducted to monitor the fate of Escherichia coli O157:H7 and Salmonella on produce (cantaloupe, honeydew melon, carrots, and celery) that were subjected to brushing or peeling using common kitchen utensils. Removal of similar levels of Salmonella from carrots was accomplished by peeling and by brushing, but significantly greater removal of E. coli O157:H7 from carrots was accomplished by peeling than by brushing under running water (P < 0.05). Brushing removed significantly fewer pathogens from contaminated cantaloupes than from other produce items (P < 0.05), suggesting that the netted rind provided sites where the pathogen cells could evade the brush bristles. A Sparta polyester brush was less effective than a scouring pad for removing Salmonella from carrots (P < 0.05). In all cases, brushing and peeling failed to eliminate the pathogens from the produce items, which may be the result of contamination of the utensil during use. High incidences of contamination (77 to 92%) were found among peelers used on carrots or celery, the Sparta brush used on carrots, and the scouring pad used on carrots and cantaloupe. Of the utensils investigated, the nylon brush had the lowest incidence of pathogen transference from contaminated produce (0 to 12%). Transfer of pathogens from a potentially contaminated Sparta brush or peeler to uncontaminated carrots did not occur or occurred only on the first of seven carrots processed with the utensil. Therefore, risk of cross-contamination from contaminated utensils to uncontaminated produce may be limited.


Subject(s)
Cooking and Eating Utensils , Escherichia coli O157/isolation & purification , Food Contamination/analysis , Salmonella/isolation & purification , Apium/microbiology , Colony Count, Microbial , Cucumis melo/microbiology , Cucurbitaceae/microbiology , Daucus carota/microbiology , Food Microbiology , Fruit/microbiology , Vegetables/microbiology
8.
J Food Prot ; 77(8): 1348-54, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25198596

ABSTRACT

Parasitic diseases can be acquired by ingestion of contaminated raw or minimally processed fresh produce (herbs and fruits). The sensitivity of methods used to detect parasites on fresh produce depends in part on the efficacy of wash solutions in removing them from suspect samples. In this study, six wash solutions (sterile E-Pure water, 3% levulinic acid-3% sodium dodecyl sulfate, 1 M glycine, 0.1 M phosphate-buffered saline, 0.1% Alconox, and 1% HCl-pepsin) were evaluated for their effectiveness in removing Cyclospora cayetanensis, Cryptosporidium parvum, and Toxoplasma gondii from basil. One hundred or 1,000 oocysts of these parasites were inoculated onto the adaxial surfaces of 25 g of basil leaves, placed in stomacher bags, and stored for 1 h at 21°C or 24 h at 4°C. Leaves were hand washed in each wash solution for 1 min. DNA was extracted from the wash solutions and amplified using PCR for the detection of all parasites. Oocysts inoculated at a concentration of 1,000 oocysts per 25 g of basil were detected in all wash solutions. At an inoculum concentration of 100 oocysts per 25 g, oocysts were detected in 18.5 to 92.6% of the wash solutions. The lowest variability in recovering oocysts from basil inoculated with 100 oocysts was observed in 1% HCl-pepsin wash solution. Oocyst recovery rates were higher at 1 h than at 24 h postinoculation. Unlike most bacteria, parasites cannot be enriched; therefore, an optimal recovery process for oocysts from suspected foods is critical. The observations in this study provide guidance concerning the selection of wash solutions giving the highest retrieval of parasite oocysts.


Subject(s)
Antiprotozoal Agents/pharmacology , Cryptosporidium parvum/isolation & purification , Cyclospora/isolation & purification , Food Parasitology/methods , Ocimum basilicum/parasitology , Toxoplasma/isolation & purification , Cryptosporidium parvum/drug effects , Cryptosporidium parvum/genetics , Cyclospora/drug effects , Cyclospora/genetics , Food Parasitology/instrumentation , Oocysts/drug effects , Plant Leaves/parasitology , Toxoplasma/drug effects , Toxoplasma/genetics
9.
Am J Trop Med Hyg ; 91(3): 537-40, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24957545

ABSTRACT

Cyclospora cayetanensis, a coccidian parasite, can cause gastrointestinal illness in humans and is characterized by watery and persistent diarrhea and abdominal pain. Cyclosporiasis has been associated with traveler's diarrhea. The infection is acquired through food and waterborne transmission, particularly by consumption of contaminated fresh fruits and vegetables. In the present study, stool samples from 8,877 children were examined for ova and parasites at the Pediatric Hospital of Morelia in Michoacán, Mexico, during 2000-2009. Sixty children (0.67%) had Cyclospora in their stools. Diarrhea (45.8%), abdominal pain (39.6%), and vomiting (18.8%) were the most frequent symptoms of cases with cyclosporiasis. Most of the cases (93.3%) were observed during June-August, the rainy season. In 45 children, Cyclospora was the only parasitic pathogen detected (75%); 15 children were co-infected with commensal, pathogenic, or both groups of parasites. Our findings suggest that C. cayetanensis is endemic to Michoacán and shows characteristically temporal patterns.


Subject(s)
Cyclospora/isolation & purification , Cyclosporiasis/epidemiology , Hospitals, Pediatric , Abdominal Pain , Adolescent , Child , Child, Preschool , Cyclospora/genetics , Cyclosporiasis/parasitology , DNA, Protozoan/genetics , Diarrhea , Feces/parasitology , Female , Humans , Infant , Male , Mexico/epidemiology , Polymerase Chain Reaction , Prevalence , Seasons
10.
Trends Parasitol ; 30(1): 37-52, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24140284

ABSTRACT

Globalisation is a manmade phenomenon encompassing the spread and movement of everything, animate and inanimate, material and intangible, around the planet. The intentions of globalisation may be worthy--but may also have unintended consequences. Pathogens may also be spread, enabling their establishment in new niches and exposing new human and animal populations to infection. The plethora of foodborne parasites that could be distributed by globalisation has only recently been acknowledged and will provide challenges for clinicians, veterinarians, diagnosticians, and everyone concerned with food safety. Globalisation may also provide the resources to overcome some of these challenges. It will facilitate sharing of methods and approaches, and establishment of systems and databases that enable control of parasites entering the global food chain.


Subject(s)
Food Parasitology/trends , Global Health , Internationality , Parasitic Diseases/prevention & control , Animals , Emigration and Immigration , Food Chain , Food Handling , Food Parasitology/standards , Humans , Parasitic Diseases/epidemiology , Risk Factors , Travel
11.
Food Environ Virol ; 5(1): 52-60, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23412721

ABSTRACT

Human noroviruses and hepatitis A virus (HAV) are commonly associated with outbreaks occurring in restaurant establishments and catered events. Food handlers are major contributing factors to foodborne illnesses initiated in the kitchen setting. In this study, transfer of HAV and murine norovirus (MNV-1), a human norovirus surrogate, between produce (cucumbers, strawberries, tomatoes, cantaloupes, carrots, and honeydew melons) and common kitchen utensils (graters and knives) was investigated. The extent of virus transfer to produce during utensil application, in the presence and the absence of food residue, and the impact of knife surface properties (sharp, dull, serrated) was also investigated. Transfer of MNV-1 and HAV from produce items, initially contaminated with ~5.5 log PFU, to knives and graters during application ranged from 0.9 to 5.1 log PFU. MNV-1 transfer to knives was the greatest for cucumbers, strawberries, and tomatoes, and the least for honeydew melons, while transfer of HAV to knives was greater for tomatoes and honeydew melons than strawberries, cantaloupes, and cucumbers. After preparation of a contaminated produce item, knife cross-contamination easily occurred as viruses were detected on almost all of the seven produce items successively prepared. Produce residues on utensils often resulted in less virus transfer when compared to utensils without residue accumulation. Knife surface properties did not impact virus transfer. The ease of virus transfer between produce and utensils demonstrated by the current study highlights the importance of efforts aimed toward preventing cross-contamination in the kitchen environment.


Subject(s)
Equipment Contamination , Food Handling/methods , Hepatitis A virus/isolation & purification , Norovirus/isolation & purification , Cooking and Eating Utensils , Cucurbitaceae/virology , Food Contamination/prevention & control , Food Microbiology , Foodborne Diseases/virology , Fragaria/virology , Solanum lycopersicum/virology
12.
Am J Trop Med Hyg ; 84(1): 38-42, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21212198

ABSTRACT

The association of wealth and infections with Giardia, Cryptosporidium, Cyclospora, and microsporidia were examined in a longitudinal cohort conducted in Peru from 2001 to 2006. Data from 492 participants were daily clinical manifestations, weekly copro-parasitological diagnosis, and housing characteristics and assets owned (48 variables), and these data were used to construct a global wealth index using principal component analysis. Data were analyzed using continuous and categorical (wealth tertiles) models. Participant's mean age was 3.43 years (range = 0-12 years), with average follow-up of 993 days. Univariate and multivariate analyses identified significant associations between wealth and infections with Giardia and microsporidia. Participants with greater wealth indexes were associated with protection against Giardia (P < 0.001) and persistent Giardia infections (> 14 days). For microsporidia, greater wealth was protective (P = 0.066 continuous and P = 0.042 by tertiles). Contrarily, infections with Cryptosporidium and Cyclospora were independent of wealth. Thus, subtle differences in wealth may affect the frequency of specific parasitic infections within low-income communities.


Subject(s)
Intestinal Diseases, Parasitic/economics , Intestinal Diseases, Parasitic/epidemiology , Poverty/statistics & numerical data , Age Factors , Child , Child, Preschool , Cryptosporidiosis/economics , Cryptosporidiosis/epidemiology , Cyclosporiasis/economics , Cyclosporiasis/epidemiology , Diarrhea/epidemiology , Diarrhea/parasitology , Female , Giardiasis/economics , Giardiasis/epidemiology , Humans , Incidence , Infant , Longitudinal Studies , Male , Multivariate Analysis , Odds Ratio , Peru/epidemiology , Poverty/economics , Principal Component Analysis , Risk Factors , Socioeconomic Factors
13.
J Food Prot ; 74(1): 140-4, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21219777

ABSTRACT

Foodborne parasites are characterized as being highly resistant to sanitizers used by the food industry. In 2009, a study reported the effectiveness of levulinic acid in combination with sodium dodecyl sulfate (SDS) in killing foodborne bacteria. Because of their innocuous properties, we studied the effects of levulinic acid and SDS at various concentrations appropriate for use in foods, on the viability of Cryptosporidium parvum and Encephalitozoon intestinalis. The viability of Cryptosporidium and E. intestinalis was determined by in vitro cultivation using the HCT-8 and RK-13 cell lines, respectively. Two Escherichia coli O157:H7 isolates were also used in the present study: strain 932 (a human isolate from a 1992 Oregon meat outbreak) and strain E 0018 (isolated from calf feces). Different concentrations and combinations of levulinic acid and SDS were tested for their ability to reduce infectivity of C. parvum oocysts (10(5)), E. intestinalis spores (10(6)), and E. coli O157:H7 (10(7)/ml) when in suspension. Microsporidian spores were treated for 30 and 60 min at 20 ± 2°C. None of the combinations of levulinic acid and SDS were effective at inactivating the spores or oocysts. When Cryptosporidium oocysts were treated with higher concentrations (3% levulinic acid-2% SDS and 2% levulinic acid-1% SDS) for 30, 60, and 120 min, viability was unaffected. E. coli O157:H7, used as a control, was highly sensitive to the various concentrations and exposure times tested. SDS and levulinic acid alone had very limited effect on E. coli O157:H7 viability, but in combination they were highly effective at 30 and 60 min of incubation. In conclusion, Cryptosporidium and microsporidia are not inactivated when treated for various periods of time with 2% levulinic acid-1% SDS or 3% levulinic acid-2% SDS at 20°C, suggesting that this novel sanitizer cannot be used to eliminate parasitic contaminants in foods.


Subject(s)
Anti-Infective Agents/pharmacology , Cryptosporidium parvum/drug effects , Encephalitozoon/drug effects , Escherichia coli O157/drug effects , Lactuca , Levulinic Acids/pharmacology , Sodium Dodecyl Sulfate/pharmacology , Animals , Chickens , Colony Count, Microbial , Consumer Product Safety , Dose-Response Relationship, Drug , Drug Combinations , Drug Synergism , Food Contamination/analysis , Food Contamination/prevention & control , Food Microbiology , Food Parasitology , Humans , Lactuca/microbiology , Lactuca/parasitology , Skin/microbiology , Temperature , Time Factors
14.
Public Health Rep ; 125(3): 441-7, 2010.
Article in English | MEDLINE | ID: mdl-20433039

ABSTRACT

OBJECTIVE: A higher incidence of infectious disease has been documented in U.S. regions bordering Mexico compared with non-border areas. We assessed the prevalence of important gastrointestinal infections in Ciudad Juarez, Mexico, and El Paso, Texas, the largest binational community along the U.S.-Mexico border. METHODS: Fecal specimens from a sample of the asymptomatic population representing all ages were tested for Helicobacter pylori (H. pylori), Cryptosporidium spp., Giardia spp., and other intestinal parasitic pathogens using flotation, immunoassays, and/or polymerase chain reaction. We also measured indicators of microbiological contamination of drinking water, hands of food preparers, and kitchen surfaces. RESULTS: Overall, of the 386 participants, H. pylori was present in 38.2%, Taenia spp. in 3.3%, Giardia spp. in 2.7%, Cryptosporidium spp. in 1.9%, Entamoeba dispar in 1.3%, and Ascaris lumbricoides and Necator americanus in 0.3% of the study subjects; Cyclospora spp. and Entamoeba histolytica were not found. H. pylori infection was associated with handwashing (prevalence ratio [PR] = 1.3, 95% confidence interval [CI] 1.0, 1.8). Taenia spp. was found more often on the U.S. side (PR=8.6, 95% CI 2.3, 30.8). We did not find an association between these infections and the occurrence of total coliforms or fecal coliforms on kitchen surfaces. In addition, Escherichia coli was not found in any drinking water sample. CONCLUSION: The study results indicated that H. pylori and Taenia spp. infections may be highly prevalent along the U.S.-Mexico border. Additional research is necessary to adequately characterize the prevalence, as well as determine whether interventions that reduce these infections are warranted.


Subject(s)
Helicobacter Infections/epidemiology , Helicobacter pylori , Intestinal Diseases, Parasitic/epidemiology , Taeniasis/epidemiology , Adolescent , Adult , Child , Child, Preschool , Cross-Sectional Studies , Female , Helicobacter Infections/prevention & control , Humans , Infant , Infant, Newborn , Intestinal Diseases, Parasitic/prevention & control , Male , Mexico/epidemiology , Middle Aged , Prevalence , Risk Factors , Taeniasis/prevention & control , United States/epidemiology
15.
Clin Microbiol Rev ; 23(1): 218-34, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20065331

ABSTRACT

The coccidian parasite Cyclospora cayetanensis is recognized as an emerging pathogen that causes protracted diarrhea in humans. The first cases of Cyclospora infection were reported in the late 1970s and were observed among expatriates and travelers in regions where infections are endemic. Since then, Cyclospora has been considered a cause of traveler's diarrhea. Epidemiological investigations were reported and examined in areas of endemicity even before the true identity of Cyclospora was elucidated. Cyclospora was fully characterized in the early 1990s, but it was not until the 1995 Cyclospora outbreak in the United States and Canada that it caught the attention of the public and physicians. The biology, clinical presentation, epidemiology, diagnosis, treatment, and control of cyclosporiasis are reviewed, with a focus on diagnostic assays currently being used for clinical and environmental samples. Challenges and limitations in working with Cyclospora are also discussed.


Subject(s)
Cyclospora/pathogenicity , Cyclosporiasis/epidemiology , Food Microbiology , Foodborne Diseases/epidemiology , Water Microbiology , Animals , Canada/epidemiology , Communicable Disease Control/methods , Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/parasitology , Cyclospora/isolation & purification , Cyclosporiasis/diagnosis , Cyclosporiasis/drug therapy , Cyclosporiasis/parasitology , Diarrhea/diagnosis , Diarrhea/drug therapy , Diarrhea/epidemiology , Diarrhea/parasitology , Foodborne Diseases/diagnosis , Foodborne Diseases/drug therapy , Foodborne Diseases/parasitology , Humans , Travel , United States/epidemiology
16.
J Hypertens ; 27(2): 259-65, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19155783

ABSTRACT

BACKGROUND: Diarrhoeal illness is a major public health problem for children worldwide, particularly among developing countries, and is a proxy condition for severe dehydration. It has been hypothesized that severe dehydration in the first 6 months of life could be associated with increased blood pressure later in life. This study aimed to explore whether frequency of diarrhoea is associated with elevated blood pressure in children in a setting with a high incidence of diarrhoeal disease. METHODS: The present study is a cross-sectional study of blood pressure among children from a longitudinal child diarrhoeal disease cohort in Lima, Peru. From 2001 to 2006, daily diarrhoeal surveillance was made. Children were revisited in 2006 and blood pressure was measured. Diarrhoeal exposures were evaluated in terms of total number of diarrhoea days, number of episodes of diarrhoea, persistent diarrhoeal episodes and by the quartiles of daily incidence and episode incidence of diarrhoea. RESULTS: The overall incidence of diarrhoeal episodes at age under 1 year was 4.35 (95% confidence interval: 3.79-4.98) and under 5 years was 2.80 (95% confidence interval: 2.69-2.92). No association was observed between the total number of diarrhoeal days, diarrhoeal episodes or diarrhoeal incidence rates with childhood blood pressure. There was weak evidence that hospital admission due to severe dehydration in the first year of life showed a gradient towards an increase in both, systolic and diastolic blood pressure. CONCLUSION: In the first study to date to examine the association in a setting with a high incidence of diarrhoeal disease, diarrhoeal frequency did not show an association with increased blood pressure. Our observations of elevated levels of blood pressure among those admitted into hospitals in the first year of life are in line with the original hypothesis of dehydration in early infancy and high blood pressure. However, the effect of episodes of severe dehydration on later blood pressure remains uncertain.


Subject(s)
Blood Pressure , Diarrhea, Infantile/epidemiology , Adolescent , Child , Child, Preschool , Cross-Sectional Studies , Dehydration/complications , Diarrhea, Infantile/complications , Female , Humans , Hypertension/etiology , Infant , Peru/epidemiology
17.
J Food Prot ; 71(12): 2410-4, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19244892

ABSTRACT

The efficacy of gaseous chlorine dioxide to reduce parasite and bacterial burden in produce was studied. Basil and lettuce leaves were inoculated with Cryptosporidium parvum and Cyclospora cayetanensis oocysts, Encephalitozoon intestinalis spores, and a cocktail of two isolates of nalidixic acid-resistant Escherichia coli O157:H7. The inoculated samples were then treated for 20 min with gaseous chlorine dioxide at 4.1 mg/liter. Cryptosporidium had a 2.6 and 3.31 most-probable-number log reduction in basil and lettuce, respectively. Reduction of Encephalitozoon in basil and lettuce was 3.58 and 4.58 CFU/g respectively. E. coli loads were significantly reduced (2.45 to 3.97 log), whereas Cyclospora sporulation was not affected by this treatment.


Subject(s)
Chlorine Compounds/pharmacology , Cryptosporidium parvum/drug effects , Cyclospora/drug effects , Disinfectants/pharmacology , Encephalitozoon/drug effects , Oxides/pharmacology , Animals , Colony Count, Microbial , Consumer Product Safety , Cryptosporidium parvum/growth & development , Cyclospora/growth & development , Encephalitozoon/growth & development , Food Microbiology , Food Parasitology , Humans , Lactuca/microbiology , Lactuca/parasitology , Ocimum basilicum/microbiology , Ocimum basilicum/parasitology , Parasite Egg Count
18.
J Food Prot ; 70(3): 681-4, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17388059

ABSTRACT

The order Microsporidia contains a number of ubiquitous pathogens that can infect various animals, including humans. Enterocytozoon bieneusi and Encephalitozoon intestinalis have been associated with gastrointestinal illness in humans. The effect of four disinfectants--ammonium hydroxide, hydrogen peroxide, and two commercial disinfectants containing peroxyacetic acid (Tsunami) and N-alkyl dimethyl benzyl ammonium chloride (Timsen)--on E. intestinalis spores was examined using exposure times of 1, 5, and 15 min. Spore viability was determined in vitro with RK-13 cells. Hydrogen peroxide was most efficient at inactivating microsporidial spores at all tested concentrations and treatment times, whereas ammonium hydroxide was effective only at the highest concentration at all exposure times. Tsunami (40 microg/ml) and Timsen (200 and 400 ppm) could inactivate spores when incubated for 5 and 15 min.


Subject(s)
Disinfectants/pharmacology , Encephalitozoon/physiology , Food Contamination/prevention & control , Spores, Fungal/growth & development , Ammonium Hydroxide , Colony Count, Microbial , Dose-Response Relationship, Drug , Food Contamination/analysis , Food Microbiology , Hydrogen Peroxide/pharmacology , Hydroxides/pharmacology , Peracetic Acid/pharmacology , Time Factors
19.
Vet Parasitol ; 144(3-4): 353-5, 2007 Mar 31.
Article in English | MEDLINE | ID: mdl-17112670

ABSTRACT

Neospora caninum is known to cause abortion in cattle. This study demonstrated the presence of specific IgG to Neospora in milk and serum samples obtained from three dairy farms in Georgia and two in Texas. Samples from four hundred fourteen dairy cows were examined using a western blot assay of which 362 were milk and 87 were serum. Samples with antibodies to Neospora were identified in 32.1% (105/327) of the examined animals in Georgia, whereas in Texas it was identified in 10.3% (9/87). Positive Georgia samples were found in 24.4% from farm A (28/115), 21.6% from farm B (30/139), and 64.4% from farm C (47/73). In Texas, 13.5% (7/52) of animals in farm D and 5.71% (2/35) from farm E also had specific antibodies to Neospora. The number of animals from Georgia dairy farms with antibodies to Neospora was significantly higher than the Texas dairy farms. This may be related to the age of the animals examined in this study (more than 2 years old). Antibodies present in sera had excellent agreement with the antibodies present in milk. Collection of milk samples for serological testing is easier and less invasive than obtaining bovine sera, therefore offering an alternative for animal testing.


Subject(s)
Antibodies, Protozoan/isolation & purification , Cattle , Coccidiosis/epidemiology , Milk/immunology , Neospora/immunology , Animals , Cattle Diseases/epidemiology , Cattle Diseases/immunology , Coccidiosis/immunology , Coccidiosis/veterinary , Dairying , Georgia/epidemiology , Immunoglobulin G/isolation & purification , Texas/epidemiology
20.
J Infect Dev Ctries ; 1(3): 345-7, 2007 Dec 01.
Article in English | MEDLINE | ID: mdl-19734618

ABSTRACT

Cyclospora cayetanensis infection continues to be a major cause of diarrhea particularly in immunosuppressed patients. The emergence of new related parasite pathogens, is an issue of public health concern. We report here a case where a Cyclospora-like organism was the cause of diarrhea in an immunocompetent patient from Venezuela.


Subject(s)
Cyclospora/isolation & purification , Cyclosporiasis/diagnosis , Diarrhea/parasitology , Adult , Cyclospora/genetics , Female , Genotype , Humans , Immunocompetence , Oocysts
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