ABSTRACT
In a one-year prospective study carried out to define the role of rotavirus and Escherichia coli in local childhood diarrhea, we determined the prevalence of both agents in 54 diarrheic children attending a health center in Botucatu. Diarrheogenic E. coli (DEC) strains were characterized by O:H serotyping, a search for virulence genetic markers, and assays of adherence to HEp-2 cells. Except for enteroaggregative E. coli (EAEC), no other DEC category was detected in the children's stools. Both EAEC and rotavirus were isolated from 22 of the 54 (41.0%) diarrheic children as single agents or in combination with other enteropathogens. However, when considering the presence of a single agent, EAEC was dominant and isolated from 20.4% of the patients, whereas rotavirus was detected in 14.8%. These results indicate that rotavirus and EAEC play a significant role as agents of childhood diarrhea in the local population.
Subject(s)
Diarrhea/microbiology , Escherichia coli Infections/microbiology , Escherichia coli/isolation & purification , Rotavirus Infections/virology , Rotavirus/isolation & purification , Adolescent , Brazil/epidemiology , Child , Child, Preschool , Diarrhea/epidemiology , Diarrhea/virology , Escherichia coli/classification , Escherichia coli/genetics , Escherichia coli Infections/epidemiology , Feces/microbiology , Feces/virology , Humans , Infant , Polymerase Chain Reaction , Prevalence , Prospective Studies , Rotavirus Infections/epidemiology , SeasonsABSTRACT
In a one-year prospective study carried out to define the role of rotavirus and Escherichia coli in local childhood diarrhea, we determined the prevalence of both agents in 54 diarrheic children attending a health center in Botucatu. Diarrheogenic E. coli (DEC) strains were characterized by O:H serotyping, a search for virulence genetic markers, and assays of adherence to HEp-2 cells. Except for enteroaggregative E. coli (EAEC), no other DEC category was detected in the children's stools. Both EAEC and rotavirus were isolated from 22 of the 54 (41.0 percent) diarrheic children as single agents or in combination with other enteropathogens. However, when considering the presence of a single agent, EAEC was dominant and isolated from 20.4 percent of the patients, whereas rotavirus was detected in 14.8 percent. These results indicate that rotavirus and EAEC play a significant role as agents of childhood diarrhea in the local population
Subject(s)
Humans , Infant , Child, Preschool , Child , Adolescent , Diarrhea , Escherichia coli , Escherichia coli Infections , Rotavirus , Bacterial Adhesion , Brazil , Diarrhea , Escherichia coli , Escherichia coli Infections , Feces , Polymerase Chain Reaction , Prevalence , Prospective Studies , SeasonsABSTRACT
Cryopreserved sperm is less fertile than fresh sperm; probably due to dependence of sperm to glycerol, a common cryoprotective agent. Few data suggest any correlations between standard semen analysis and fertility. To develop a reliable assay, the authors hypothesized that sperm that withstand the physiochemical stress induced by glycerol during cryopreservation may have higher fertility potential. They analyzed 55 cryopreserved semen samples for sperm concentration, percent motility and progressive motility after allowing thawed sperm to migrate into medium containing either 0 or 12% glycerol for 3 h. The smaller the difference in sperm quality between the two media, the higher the fertility potential of the spermatozoa. There was significant negative correlation between the difference in both percent sperm motility and percent progressive sperm motility in the two media and in vitro fertilization outcome. There was a significantly higher number of ejaculates fertilized oocytes at a rate of > or = 80% when the difference was 20% or less. This easy to use, inexpensive test may be an effective means to evaluate the potential performance of cryopreserved sperm to be utilized in assisted reproductive technologies.
Subject(s)
Cryopreservation , Cryoprotective Agents/pharmacology , Fertility/physiology , Glycerol/pharmacology , Semen Preservation , Spermatozoa/physiology , Cell Survival , Culture Media , Humans , In Vitro Techniques , Male , Sperm MotilityABSTRACT
OBJECTIVE: To develop a simple assay using the silica wool filtration (SIFT) procedure to estimate percentage of acrosome-reacted (AR) sperm. SETTING: Private andrology laboratory. MATERIALS AND METHODS: Capacitated sperm processed by the SIFT procedure to remove nonviable sperm and those with broken membrane were acrosome reacted by induction with a calcium ionophore. Following the acrosome reaction, the sample was processed by the SIFT procedure. Sperm concentration and acrosomal status were also determined before and after the SIFT procedure. RESULTS: The SIFT procedure prevented AR sperm from filtering (mean +/- SD, 22.2 +/- 1.9 vs. 9.8 +/- 4.9%). The mean percent of sperm retained in the filter (SIFT assay: 61.8 +/- 21.5%) was significantly higher than the percent of AR sperm estimated by a staining technique (26.4 +/- 7.3%), but they were significantly correlated (r = .34) with each other. The filtration of capacitated sperm prior to induction of the acrosome reaction eliminated, or at least minimized, the possibility of falsely increasing the percent of AR sperm estimated by the SIFT assay. The higher estimate obtained by SIFT assay, therefore, suggests that it may be estimating sperm at various stages that are undergoing the acrosome reaction. CONCLUSION: The findings suggest that the SIFT assay could be used to estimate the percentage of AR spermatozoa.
