Optimization of laccase-alginate-chitosan-based matrix toward 17 α-ethinylestradiol removal.

Laccase extract (LE) from Pycnoporus sanguineus was immobilized on calcium and copper alginate-chitosan beads and applied for the removal of 17α-ethinylestradiol (EE2). Effects of immobilization conditions such as: sodium alginate (SA) concentration; LE/SA ratio and chitosan/ion (Ca+2 or Cu+2) ratio on the immobilization yield were investigated. Immobilized LE on Ca-beads and Cu-beads was then used to degrade an EE2 solution. The optimal conditions for LE immobilization on Ca-beads were: 1.5% (w/v) SA, 1:5 (v/v) LE/SA and 3:7 (v/v) chitosan/ion (Ca+2). The optimal conditions for immobilization on Cu-beads were 2.0% (w/v) SA, 0.5:5 (v/v) LE/SA and 3:7 (v/v) chitosan/ion (Cu+2). The best result was obtained for immobilized LE on Ca-beads in buffer-absent medium. Furthermore, the immobilized enzyme was reused in five cycles for EE2 removal. The formation of EE2 dimers by LE treatment has been demonstrated by electrospray ionization coupled to time of flight mass spectrometer (ESI-TOF-MS). The results evidenced that immobilized LE in alginate-chitosan-divalent cation bead is an effective alternative for EE2 removal.

Cryptosporidium rubeyi n. sp. (Apicomplexa: Cryptosporidiidae) in multiple Spermophilus ground squirrel species.

Previously we reported the unique Cryptosporidium sp. "c" genotype (e.g., Sbey03c, Sbey05c, Sbld05c, Sltl05c) from three species of Spermophilus ground squirrel (Spermophilus beecheyi, Spermophilus beldingi, Spermophilus lateralis) located throughout California, USA. This follow-up work characterizes the morphology and animal infectivity of this novel genotype as the final step in proposing it as a new species of Cryptosporidium. Analysis of sequences of 18S rRNA, actin, and HSP70 genes of additional Cryptosporidium isolates from recently sampled California ground squirrels (S. beecheyi) confirms the presence of the unique Sbey-c genotype in S. beecheyi. Phylogenetic and BLAST analysis indicates that the c-genotype in Spermophilus ground squirrels is distinct from Cryptosporidium species/genotypes from other host species currently available in GenBank. We propose to name this c-genotype found in Spermophilus ground squirrels as Cryptosporidium rubeyi n. sp. The mean size of C. rubeyi n. sp. oocysts is 4.67 (4.4-5.0) µm × 4.34 (4.0-5.0) µm, with a length/width index of 1.08 (n = 220). Oocysts of C. rubeyi n. sp. are not infectious to neonatal BALB/c mice and Holstein calves. GenBank accession numbers for C. rubeyi n. sp. are DQ295012, AY462233, and KM010224 for the 18S rRNA gene, KM010227 for the actin gene, and KM010229 for the HSP70 gene.

Multiple unique Cryptosporidium isolates from three species of ground squirrels (Spermophilus beecheyi, S. beldingi, and S. lateralis) in California.

Phylogenetic analyses of the 18S small-subunit (SSU) rRNA and Cryptosporidium oocyst wall protein (COWP) genes indicate that multiple unique Cryptosporidium isolates are shed by separate species of Spermophilus ground squirrels (S. beecheyi, S. beldingi, and S. lateralis) throughout California, despite some squirrel populations' being geographically isolated. The data support our assertion that Spermophilus squirrels shed novel Cryptosporidium species.

Prevalence and associated risk factors for Giardia lamblia infection among children hospitalized for diarrhea in Goiânia, Goiás State, Brazil.

The objective of this study was to determine the prevalence and to identify risk factors associated with Giardia lamblia infection in diarrheic children hospitalized for diarrhea in Goiânia, State of Goiás, Brazil. A cross-sectional study was conducted and a comprehensive questionnaire was administered to the child's primary custodian. Fixed effects logistic regression was used to determine the association between infection status for G. lamblia and host, sociodemographic, environmental and zoonotic risk factors. A total of 445 fecal samples were collected and processed by the DFA methodology, and G. lamblia cysts were present in the feces of 44 diarrheic children (9.9%). A variety of factors were found to be associated with giardiasis in these population: age of children (OR, 1.18; 90% CI, 1.0 - 1.36; p = 0.052), number of children in the household (OR 1.45; 90% CI, 1.13 - 1.86; p = 0.015), number of cats in the household (OR, 1.26; 90% CI, 1.03 -1.53; p = 0.059), food hygiene (OR, 2.9; 90% CI, 1.34 - 6.43; p = 0.024), day-care centers attendance (OR, 2.3; 90% CI, 1.20 - 4.36; p = 0.034), living on a rural farm within the past six months prior hospitalization (OR, 5.4; CI 90%, 1.5 - 20.1; p = 0.03) and the number of household adults (OR, 0.59; 90% CI, 0.42 - 0.83; p = 0.012). Such factors appropriately managed may help to reduce the annual incidence of this protozoal infection in the studied population.

Prevalence and associated risk factors for Giardia lamblia infection among children hospitalized for diarrhea in Goiânia, Goiás State, Brazil

The objective of this study was to determine the prevalence and to identify risk factors associated with Giardia lamblia infection in diarrheic children hospitalized for diarrhea in Goiânia, State of Goiás, Brazil. A cross-sectional study was conducted and a comprehensive questionnaire was administered to the child's primary custodian. Fixed effects logistic regression was used to determine the association between infection status for G. lamblia and host, sociodemographic, environmental and zoonotic risk factors. A total of 445 fecal samples were collected and processed by the DFA methodology, and G. lamblia cysts were present in the feces of 44 diarrheic children (9.9 percent). A variety of factors were found to be associated with giardiasis in these population: age of children (OR, 1.18; 90 percent CI, 1.0 - 1.36; p = 0.052), number of children in the household (OR 1.45; 90 percent CI, 1.13 - 1.86; p = 0.015), number of cats in the household (OR, 1.26; 90 percent CI, 1.03 -1.53; p = 0.059), food hygiene (OR, 2.9; 90 percent CI, 1.34 - 6.43; p = 0.024), day-care centers attendance (OR, 2.3; 90 percent CI, 1.20 - 4.36; p = 0.034), living on a rural farm within the past six months prior hospitalization (OR, 5.4; CI 90 percent, 1.5 - 20.1; p = 0.03) and the number of household adults (OR, 0.59; 90 percent CI, 0.42 - 0.83; p = 0.012). Such factors appropriately managed may help to reduce the annual incidence of this protozoal infection in the studied population.

O objetivo desse estudo foi estimar a prevalência e identificar fatores de risco associados à infecção por Giardia lamblia em crianças hospitalizadas com diarréia no município de Goiânia, Estado de Goiás, Brasil. Foi realizado um estudo transversal e um questionário estruturado foi administrado ao responsável pela criança. Análise multivariada foi realizada por meio de regressão logística para se determinar a associação entre infecção por G. lamblia e as variáveis sociodemográficas, ambientais e zoonóticas relacionadas ao hospedeiro. Das 445 amostras de fezes coletadas e processadas pelo método de imunofluorescência direta (DFA), 44 (9,9 por cento) apresentaram cisto de G. lamblia. Uma variedade de fatores de risco foi encontrada associada à giardíase: idade da criança (OR, 1,18; 90 por cento CI, 1,0 - 1,36; p = 0,052), número de crianças na família (OR, 1,45; 90 por cento CI, 1,13 - 1,86; p = 0,015), número de gatos pertecentes à família (OR, 1,26; 90 por cento CI, 1,03 - 1,53; p = 0,059), higiene alimentar (OR, 2,9; 90 por cento CI, 1,34 - 6,43; p = 0,024), usuários de creches (OR, 2,3; 90 por cento CI, 1,20 - 4,36; p = 0,034), ter residido em área rural seis meses precedendo à hospitalização (OR, 5,4; 90 por cento CI, 1,5 - 20,1; p = 0,03) e número de adultos na família (OR, 0,59; 90 por cento CI, 0,42 - 0,83; p = 0,012). Tais fatores, devidamente controlados podem contribuir para redução anual da incidência desta parasitose na população estudada.

Efficacy of natural grassland buffers for removal of Cryptosporidium parvum in rangeland runoff.

Our goal for this project was to estimate the retention efficiency of natural grassland buffers for Cryptosporidium parvum. Three sets of 16 plots (2.0 by 3.0 m) were established at 5, 20, and 35% slopes. Within each set of 16 plots, residual dry vegetation matter treatments of 225, 560, and 900 kg/ha were implemented, along with a noncut control averaging 4,500 kg/ ha. Buffer width treatments were implemented by placing cattle fecal material containing known loads of C. parvum 0.1, 1.1, or 2.1 m up-slope of the runoff collector. Grassland buffers of 1.1 and 2.1 m generated 3.2- to 8.8-log and 3.6- to 8.8-log retention of C. parvum, respectively, across the range of residual dry vegetation matter, land slope, rainfall, and runoff conditions examined during this project. Buffers with an increased percent land slope exhibited improved the retention efficiencies, whereas buffers experiencing larger maximum annual runoff events exhibited reduced retention efficiencies. Water-quality data from the 0.1-m-wide buffer plots (effectively no buffer) demonstrated that the majority of C. parvum oocysts (98 to 99.999%) were retained in the fecal matrix for the duration of the storm season, irrespective of the presence of a vegetated buffer. In conclusion, these results support the assertion that grassland buffers are an effective method for reducing animal agricultural inputs of waterborne C. parvum into drinking and irrigation water supplies.

Intra-familial and extra-familial risk factors associated with Cryptosporidium parvum infection among children hospitalized for diarrhea in Goiânia, Goiás, Brazil.

A cross-sectional study was conducted for assessing the prevalence of and risk factors associated with Cryptosporidium parvum in diarrheic children who were hospitalized in Goiânia, capital of Goiás State in Brazil. A crude prevalence of 14.4% (64 of 445) was observed using a direct immunfluorescent assay (DFA), but the true prevalence was 18.7% (83 of 445) when a gold standard of immunomagnetic separation was used in combination with the DFA. Infection was more predominant in children less than 24 months old (odds ratio [OR] = 0.50, 90% confidence interval [CI] = 0.36-0.68, P = 0.0001), and males were 2.2 times more at risk for infection when compared with females (OR = 2.2. 90% CI = 0.13-3.8, P = 0.01). The socioeconomic, intra-familial, and environmental factors associated with cryptosporidiosis were day care attendance, household children with diarrhea up to 30 days prior to the interview, contact with surface water within past 30 days prior to the interview, dwelling distance from a body of water, and the late rainy season (P < 0.10). C. parvum was not associated with the parent's occupation, household sleeping arrangements, number of caregivers, breast-fed children, diet and type of food hygiene, source and type of treatment of drinking water, presence of sewage, and animal exposure (P > 0.10). Although weight was not found to be associated with infection, children infected with C parvum weighed on average 2.0% less than children not infected with C. parvum (P > 0.10). Thus, C. parvum is an important etiologic agent of childhood diarrhea and should be identified in routine parasitologic tests of diarrheal stool samples.