Dental caries are more likely to impact on children's quality of life than malocclusion or traumatic dental injuries

AIM

To measure the impact of dental caries, malocclusion, and traumatic dental injuries (TDI) on the oral health-related quality of life (OHRQoL) of Brazilian children.

STUDY DESIGN

population-based cross-sectional study. MATERIALS AND METHODS A representative sample of 1,204 8-to-10-year-old children randomly selected from 19 public and private schools in Belo Horizonte (Brazil) was evaluated. The Decayed, Missing and Filled Teeth Index (DMFT), the Dental Aesthetic Index (DAI), and Andreasen's classification were used by two calibrated examiners to diagnose dental caries, malocclusion, and TDI, respectively. Children were clinically examined at school. The Brazilian version of the Child Perceptions Questionnaire for ages 8 to 10 years (CPQ8-10) was used to assess the impact on OHRQoL.

RESULTS

There were statistically significant differences (p<0.001) between groups (dental caries, malocclusion, and TDI) in all subscales and the CPQ8-10 total score. The presence of dental caries alone and its association with TDI and malocclusion were associated with all CPQ8-10 subscales (p<0.05).

STATISTICS

the Poisson regression model with a robust variance estimator was utilised for the multivariate analysis. Adjusted prevalence ratios were obtained for the association between oral conditions and the total score on the CPQ8-10 and its subscales.

CONCLUSION

Dental caries seems to be the oral condition most commonly associated with a higher impact on the OHRQoL of Brazilian 8-to-10-year-olds.

Impact of malocclusion on the quality of life of children aged 8 to 10 years

OBJECTIVE

The aim of the present cross-sectional study was to assess the impact of malocclusion on the quality of life of children aged 8 to 10 years attending public elementary schools in Belo Horizonte, State of Minas Gerais, Brazil.

METHODS

The Brazilian version of the Child Perceptions Questionnaire 8-10 (CPQ8-10) was used to evaluate oral health-related quality of life. The children were examined for the diagnosis of malocclusion using the Dental Aesthetic Index (DAI). The data were analyzed by bivariate and multivariate descriptive statistics using Poisson regression at a 5% significance level. A total of 270 children participated in the study.

RESULTS

Children with normal occlusion or mild malocclusion (DAI ≤ 25) were 56% less likely (95%CI: 0.258-0.758; p= 0.003) to have their quality of life affected compared with children diagnosed with extremely severe malocclusion (DAI ≥ 36). Children with a maxillary anterior overjet ≥ 3 mm had higher CPQ8-10 mean scores (19.4; SD = 17.1) than those with an overjet < 3 mm (13.6; SD = 11.7; p= 0.038).

CONCLUSIONS

Extremely severe malocclusion and pronounced maxillary anterior overjet were associated with a negative impact on quality of life.

Dental caries and social factors: impact on quality of life in Brazilian children

The objective of this study was to evaluate the impact of dental caries and social determinants in the Oral Health Related Quality of Life (OHRQoL) of children in Belo Horizonte, Brazil. This is a population-based cross-sectional study with a representative sample of 1,204 children aged 8 to 10 years randomly selected from 19 public and private schools. The children were clinically examined at school by two trained and calibrated examiners (Kappa = 0.78 - 1.00). The Decayed, Missing and Filled Teeth Index (DMF-T and dmf-t) was used for the diagnosis of dental caries. The social factors were determined by parents'/caregivers' schooling, household income, number of people in the household, type of school, and by the Social Vulnerability Index. The Brazilian version of the Child Perceptions Questionnaire for ages 8 to 10 years was used to assess the impact on quality of life. A total of 278 (23.1%) out of 1,204 children had at least one cavitated carious lesion and 47.0% presented a negative impact on OHRQoL. In the final multivariate Poisson's regression model, household income and presence of untreated dental caries were statistically associated with a negative impact on OHRQoL (p < 0.001).Children with dental caries and from low-income families had a higher negative impact on OHRQoL.

Oral Health-Related Quality of Life and Traumatic Dental Injuries in Young Permanent Incisors in Brazilian Schoolchildren: A Multilevel Approach

BACKGROUND

Traumatic dental injury (TDI) during childhood may negatively impact the quality of life of children.

OBJECTIVE

To describe the association of oral health-related quality of life (OHRQoL) and domains (oral symptons, functional limitation, emotional- and social-well-being) of children with individual and contextual variables.

METHODS

A cross-sectional study was performed using a representative sample of 1,201 schoolchildren, 8-10 years-old, from public and private schools of Belo Horizonte, Brazil. The CPQ8-10 was used to assess OHRQoL, dichotomized in low and high impact. Sociodemographic information was collected through questionnaires to parents. Children were examined at schools, using the Andreasen criteria. Individual variables were gender, age, number of residents in home, parents/caregivers' level of education, family income, and TDI (dichotomized into without trauma/mild trauma and severe trauma). Dental caries and malocclusion were considered co-variables. Contextual variables were the Social Vulnerability Index and type of school. Ethical approval and consent forms were obtained. Data were analyzed using SPSS for Windows 19.0 and HLM 6.06, including frequency distribution, chi-squared test and multilevel approach (p < 0.05).

RESULTS

The prevalence of a negative impact on OHRQoL in children with severe trauma was 55.9%. The TDI negatively impacted emotional and social domains of OHRQoL. A multilevel analysis revealed a significant difference in OHRQoL according to the type of school and showed that 16% of the total variance was due to contextual characteristics (p < 0.001; ICC = 0.16). The negative impact on OHRQoL was higher in girls (p = 0.009), younger children (p = 0.023), with severe TDI (p = 0.014), those from public schools (p = 0.017) and whose parents had a lower education level (p = 0.001).

CONCLUSION

Severe trauma impacts OHRQoL on emotional and social domains. Contextual dimensions add information to individual variability to explain higher impact, emphasizing socioeconomic inequalities.

Toxicological in vitro and subchronic evaluation of LASSBio-596

LASSBio-596, 2-[4-(1,4-tiazinan-4-ylsulfonyl) phenylcarbamoyl] benzoic acid, is an achiral compound containing a subunit carboxylic amide, was capable of preventing induced mechanical and morphological changes in the lungs that commonly caused the onset of asthma. Previous studies to determine the acute toxicity of oral LASSBio-596 at dose of 2000mg/kg caused no deaths in any of the tested animals. To further evaluate the safety of LASSBio-596, in vitro and in vivo tests were carried out. Regarding to in vitro test were used renal, hepatic, pulmonary, cardiac, neurologic and intestinal cell lines. They were evaluated using neutral red (NR) and [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assays. Micronuclei also was performed. Concerning to in vivo was performed subchronic on Wistar rats at doses of 10, 50, and 250mg/kg and zebrafish test. The in vitro tests results showed the safety of LASSBio-596. However, subchronic toxicity study results revealed changes in the blood parameters of amylase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose and creatine kinase (CK) which is used for cardiotoxicity evaluation, although, did not identify any histopathological alterations. However, zebrafish test demonstrated cardiac damage. It was impossible to estimate the no-observed-adverse-effect-levels and lowest observed-adverse-effect level due to the presence of cardiotoxicity in all tested doses.

Campomanesia lineatifolia Ruiz & Pav. as a gastroprotective agent

ETHNOPHARMACOLOGICAL RELEVANCE

Campomanesia lineatifolia Ruiz and Pav. (Myrtaceae) is a native edible species found in the Amazon Rainforest, commonly known as gabiroba. In Brazil, Campomanesia species are frequently used in traditional medicine for gastrointestinal disorders.

MATERIALS AND METHODS

The present study performed phytochemical analyses and determined both the in vitro antioxidant activity of the ethanolic extract of Campomanesia lineatifolia leaves (EEC) as well as its ethyl acetate fraction (EAFC). In this analysis, quercetin was used as a positive control. Gastroprotective activity was also investigated at different oral doses in two experimental models in rats - gastric lesion induced by ethanol and gastric lesion induced by indomethacin. In this analysis, cimetidine and sucralfate were used as positive controls. The area of gastric lesion underwent macroscopic and histomorphometric evaluations, while the mucus content was estimated by applying the periodic acid-Schiff stain. Oral acute toxicity was also assessed.

RESULTS

Phytochemical studies revealed the presence of flavonoids and tannins. Catechin and quercitrin were isolated by bioguided chromatographic fractionation of EAFC. EEC and EAFC presented in vitro antioxidant activity. The oral administration of EEC and EAFC at doses 100-400 mg/kg (ethanol model) and at doses of 400-1200 mg/kg (indomethacin model) proved to be effective in preventing gastric ulcerations in rats. Pretreatment with EAFC (400mg/kg) significantly increased the gastric mucus content in the ethanol model. No animals died during the acute oral toxicology test.

CONCLUSIONS

Results confirm the Brazilian ethnopharmacological use of Campomanesia lineatifolia as a gastroprotective agent and indicate that the anti-ulcer effect is most likely mediated by scavenging free radicals due to the polyphenol content and, at least in part, by increasing the mucus secretion and the mucosal defense. In addition, EEC and EAFC were found to be safe when applied to a 2000 mg/kg single oral dose.

Feeding and nonnutritive sucking habits and prevalence of open bite and crossbite in children/adolescents with Down syndrome

OBJECTIVE

To analyze the influence of breastfeeding, bottle feeding, and nonnutritive sucking habits on the prevalence of open bite and anterior/posterior crossbite in children with Down syndrome (DS).

MATERIALS AND METHODS

A cross-sectional study was carried out in 112 pairs of mothers/children with DS between 3 and 18 years of age at a maternal/children's hospital in Rio de Janeiro, Brazil. The children with DS were clinically examined for the presence of open bite as well as anterior and posterior crossbite. Information on breastfeeding, bottle feeding, and nonnutritive sucking habits was collected using a structured questionnaire. The control variables were age and mouth posture of children/adolescents and mother's schooling. Statistical analysis of the data was performed using the chi-square test and multiple logistic regression.

RESULTS

The prevalence of anterior open bite was 21%, anterior crossbite was 33%, and posterior crossbite was 31%. The use of bottle feeding for more than 24 months (prevalence ratio [PR] = 1.6) was associated with the occurrence of open bite. Having breastfed for less than 6 months (PR = 1.4) and pacifier sucking for more than 24 months (PR = 3.1) were associated with the prevalence of anterior crossbite. Finger sucking (PR = 2.9) and the use of bottle feeding for more than 24 months (PR = 2.6) were associated with posterior crossbite.

CONCLUSION

The prevalence of open bite and crossbite in children with DS was associated with the use of bottle feeding and pacifier sucking for more than 24 months, breastfeeding for less than 6 months, and finger sucking.

Preliminary validation of the Brazilian version of the Child Perceptions Questionnaire 8-10

AIM

The aim of the study was to perform a preliminary validation of the Brazilian version of the Child Perceptions Questionnaire 8-10 (CPQ 8-10).

METHODS

The sample used to test the measurement equivalence was made up of 59 children from 8 to 10 years of age at the Federal University of Minas Gerais, Brazil. The CPQ 8-10 was administered, and clinical exams were performed by a single examiner, calibrated for the diagnosis of dental caries (Kappa= 0.98) and malocclusion (weighted Kappa and intraclass correlation coefficient = 0.66-1.00). The children were divided into three groups according to their clinical condition (22 with cavitated carious lesions; 20 with malocclusion; 17 with both oral conditions).

STATISTICS

The internal consistency of the instrument was assessed by Cronbach's alpha Coefficient. The Intraclass correlation coefficient (ICC) was used for the test-retest reliability (40 children). Discriminant validity was determined using the Kruskal-Wallis test.

RESULTS

An assessment of the psychometric properties revealed the instrument to be reliable (Cronbach's alpha=0.92 for the total scale and 0.63-0.85 for the subscales), exhibiting excellent stability (ICC=0.96 for the total scale and 0.79-0.95 for the subscales). Construct validity was demonstrated through the significant correlations between the global indicators and subscales. There were statistically significant differences between the clinical groups regarding the total scale, thereby demonstrating discriminant validity (p=0.03).

CONCLUSIONS

The preliminary validation of the Brazilian version of the CPQ 8-10 showed valid and reliable for use on Brazilian children.

Maspin expression in carcinoma ex pleomorphic adenoma

AIMS

To investigate the presence and distribution of the protein maspin in carcinoma ex pleomorphic adenoma (CXPA).

METHODS

Maspin expression was studied by means of immunohistochemistry in 16 cases of CXPA, using the labelled polymer method.

RESULTS

According to the extent of invasion, the tumours were subdivided into: intracapsular (five cases), minimally invasive (four cases), and invasive (seven cases). Twelve patients had carcinoma with only epithelial differentiation, whereas four had a malignant myoepithelial component. Non-luminal cells in the duct-like structures of the remnant pleomorphic adenoma were strongly positive for maspin, whereas only a few luminal cells were immunopositive. A few positive cells were seen in the frequent hypocellular and hyalinised areas. Maspin was abundantly expressed, mainly in non-luminal cells, in transitional areas of CXPA with only epithelial differentiation. In frankly carcinomatous areas there was a gradual decrease in maspin expression. Almost all cells were maspin positive in CXPA with a myoepithelial component. When present, luminal cells were in general negative for maspin.

CONCLUSIONS

When only epithelial cells undergo malignant transformation, maspin expression is gradually lost. In cases with a myoepithelial component, maspin expression is high, and this might be related to the tumour suppressor activity attributed to this cell.

Carcinoma ex pleomorphic adenoma (CXPA): immunoprofile of the cells involved in carcinomatous progression

AIMS

To characterize the cellular component in pleomorphic adenoma (PA) that undergoes malignant transformation in carcinoma ex pleomorphic adenoma (CXPA).

METHODS AND RESULTS

A panel of antibodies against cytoskeletal proteins was applied in 16 cases of CXPA: intracapsular carcinoma (five cases), minimally invasive (four cases) and frankly invasive (seven cases). The CXPAs were classified into two main groups according to their predominant cellular component as detected by the panel of antibodies: (i) carcinomas with only epithelial differentiation (75% of the cases), and (ii) carcinomas with a myoepithelial component (25%). CXPA with only epithelial differentiation showed two types of malignant areas in the part of the tumour that was confined by the PA capsule: (i) intraductal carcinoma areas characterized by ductal structures containing both benign myoepithelial cells positive for alpha-smooth muscle actin (alpha-SMA), vimentin and cytokeratin (CK)14 and proliferating atypical luminal cells reactive for CK7, CK8 and CK19, and (ii) carcinoma areas composed only of epithelial cells reactive for CK7, CK8 and CK19. In the latter, the cells presented morphological and immunohistochemical characteristics similar to those found in areas of invasive carcinoma outside the PA capsule. CXPAs with a myoepithelial component were composed mainly or exclusively of cells that expressed vimentin and alpha-SMA. In this group, ductal structures reminiscent of PA filled by malignant cells were not identified.

CONCLUSION

Most CXPAs consist only of epithelial cells that have an immunoprofile comparable to ductal luminal cells of PA. These malignant luminal cells arise in the duct-like structures as intraductal carcinoma and probably only at this early stage of development should the lesion be considered as a non-invasive carcinoma.

Expression of integrin subunits alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 in different histological types of ameloblastoma compared with dental germ, dental lamina and adult lining epithelium

OBJECTIVE

To analyze integrin expression and distribution in different histological types of ameloblastoma, compared with dental germ, dental lamina and adult lining epithelium.

MATERIALS AND METHODS

Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method and anti-integrin alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 antibodies.

RESULTS

All integrins were present in all specimens, exhibiting different patterns. In follicular ameloblastoma, the integrin staining was stronger in the periphery while integrin alpha2 was not present in the central cells. Acanthomatous ameloblastoma showed a similar pattern, with positive staining for integrins alpha3, alpha5, alphav, beta1 and beta4 in the metaplastic cells. In the unicystic, integrin staining was uniform except for integrins alpha5 and beta3 which showed weaker staining in the upper layers. In the plexiform ameloblastoma, dental germ and lamina integrin staining was uniform. In the adult lining epithelium, staining for integrins alpha2, alpha5 and beta4 was confined to the basal layer, while integrins alphav and beta3 were present in the basal and parabasal, with integrins alpha3 and beta1 in the upper layers.

CONCLUSION

Acanthomatous, follicular and unicystic ameloblastomas showed integrin staining patterns similar to the adult lining epithelium while the plexiform ameloblastoma was similar to the dental germ and lamina.

Leiomyomatous hamartoma of the incisive papilla

A case of unusual hamartoma in a six-year-old otherwise healthy Brazilian girl is reported, with emphasis on histological and immunohistochemical features. A mass observed in the incisive papilla was detected whose appearance was similar to congenital epulis or fibroma. Histological findings showed interlacing fascicles of large spindle cells resembling smooth muscle cells. Immunohistochemical staining for desmin and for smooth-muscle actin was positive. The histological diagnosis was leiomyomatous hamartoma, based on clinical and microscopic observations.

Immunohistochemical Mdm2 expression in minor salivary gland tumours and its relationship to p53 gene status

Mdm2 protein is a cellular regulator of p53 protein activity. Minor salivary gland tumours were investigated for immunohistochemical expression of Mdm2 protein and for p53 gene status. Formalin-fixed sections were submitted to monoclonal antibody anti-Mdm2 through use of the streptavidin-biotin method. Nuclear immunoreactivity was scored 1 (0-25% nuclei positive), 2 (26-50%), 3 (51-75%) and 4 (> 75%). The scores found were: PLGA = 1-4; ACC = 3 and 4; ACA = 2 and 4; PA = 3. Genomic DNA of p53 gene exons 5-8 was examined by polymerase chain reaction and no alterations were detected. The strong immunohistochemical Mdm2 expression may represent an alternative mechanism to the development of salivary gland tumours.

Extranodal follicular dendritic cell sarcoma of the palate

Follicular dendritic cell tumors are uncommon and usually occur in lymph nodes. We report the case of a follicular dendritic cell tumor that occurred in the palate of a 14-year-old boy and manifested itself as a nodular mass. Histologically, the neoplasm consisted of spindle-shaped or oval-shaped cells with eosinophilic cytoplasms and nuclei with delicate, dispersed chromatin. The lesional cells were principally arranged in diffuse, fascicular patterns with vaguely whorled or storiform areas. Focal multinucleate tumor giant cells and lymphocytes were observed throughout the neoplasm. Immunohistochemically, tumor cells were positive for the follicular dendritic cell markers CD21, CD35, and CD23 and for S-100 protein, CD68, and muscle-specific actin. Tumor cells were negative for LCA, CD20, EMA, CK (AE1/AE3), HMB45, and CD34. Lymphocytes were positive for LCA and CD45RO. Although follicular dendritic cell sarcoma is a very uncommon tumor, it should be included in the differential diagnosis of tumors in this location.

Plasma kinetics of a chylomicron-like emulsion in patients with coronary artery disease

Chylomicron catabolism in the bloodstream consists of lipolysis by lipoprotein lipase and uptake of remnants by the liver. In rats, triglyceride-rich emulsions can mimic chylomicron metabolism. To further validate this model in man, the emulsion was injected intravenously into fasting and into subjects previously fed a test fatty meal. The plasma kinetic curves of the emulsion 3H-triglyceride and 14C-cholesteryl ester were determined. The fractional clearance rate (FCR) of both labels was markedly reduced in the fed subjects (triglycerides: fed = 0.018 +/- 0.007; fasting = 0.105 +/- 0.013 min-1, P < 0.001; cholesteryl ester: fed = 0.016 +/- 0.001; fasting = 0.040 +/- 0.006 min-1; P < 0.05) indicating that the emulsion and chylomicrons generated from the testinal lipid absorption compete for the same catabolic processes, confirming the validity of the method. The emulsion was injected into 11 patients with CAD and into 11 controls. All had plasma cholesterol < 240 and triglycerides < 250 mg/dl. FCR of triglycerides was 5-fold smaller in CAD compared to controls (0.028 +/- 0.004 and 0.141 +/- 0.069 min-1, respectively, P < 0.01). FCR of cholesteryl ester was 4-fold smaller in CAD than in controls (0.015 +/- 0.004 and 0.056 +/- 0.067 min-1 respectively, P < 0.05). These results indicate that both chylomicron lipolysis and remnant removal are diminished in CAD.

Mutagenicity of airborne particulate organic material from urban and industrial areas of São Paulo, Brazil

The mutagenicity of airborne particulate matter at three different sites within the São Paulo urban area and the Cubatão industrial area, São Paulo State, Brazil, was evaluated using the Salmonella mutagenicity assay over a year's period (June 1990-May 1991). Total suspended particles (TSP) were collected using a Hi-vol sampler and extracted with methylene chloride by ultrasonication. Pooled seasonal extracts were tested using S. typhimurium TA98 and TA100 with and without metabolic activation (S9) and TA98NR and TA98/1,8-DNP6 without metabolic activation. Organic extracts of the samples with the highest monthly TSP concentration were also assayed for mutagenicity. All samples collected at São Paulo and Cubatão showed mutagenicity with strain TA98, and in general the addition of S9 did not modify the mutagenic response, suggesting the prevalence of direct-acting frameshift mutagens in the atmosphere of these sites. The mutagenicity detected in the urban areas of São Paulo (mainly downtown) was much higher than in the Cubatão industrial area and similar to the more urbanized cities in the world, where vehicle emissions are the major pollution source. Results obtained with the strains TA98NR and TA98/1,8-DNP6 suggested the presence of mononitro- and dinitroarenes contributed to the mutagenicity of these atmospheric samples. A seasonal variation was observed with higher levels of frameshift mutagens during Spring in São Paulo and Summer in Cubatão. During the Winter, more significant responses were found with strain TA100 in the presence of S9 at all sites. Monthly samples presented high levels of mutagenicity during the period of June to November. Results from this research provide support for Air Pollution Control Programs in the detection of the more potent organic mutagenic compounds in the atmosphere and may help in the establishment of priorities for control and regulatory actions.

Enterobacterial repetitive intergenic consensus sequences and the PCR to generate fingerprints of genomic DNAs from Vibrio cholerae O1, O139, and non-O1 strains

Enterobacterial repetitive intergenic consensus (ERIC) sequence polymorphism was studied in Vibrio Cholerae strains isolated before and after the cholera epidemic in Brazil (in 1991), along with epidemic strains from Peru, Mexico, and India, by PCR. A total of 17 fingerprint patterns (FPs) were detected in the V. cholerae strains examined; 96.7% of the toxigenic V. cholerae O1 strains and 100% of the O139 serogroup strains were found to belong to the same FP group comprising four fragments (FP1). The nontoxigenic V. cholerae O1 also yielded four fragments but constituted a different FP group (FP2). A total of 15 different patterns were observed among the V. cholerae non-O1 strains. Two patterns were observed most frequently for V. cholerae non-01 strains, 25% of which have FP3, with five fragments, and 16.7% of which have FP4, with two fragments. Three fragments, 1.75, 0.79, and 0.5 kb, were found to be common to both toxigenic and nontoxigenic V. cholerae O1 strains as well as to group FP3, containing V. cholerae non-O1 strains. Two fragments of group FP3, 1.3 and 1.0 kb, were present in FP1 and FP2 respectively. The 0.5-kb fragment was common to all strains and serogroups of V. cholerae analyzed. It is concluded from the results of this study, based on DNA FPs of environmental isolates, that it is possible to detect an emerging virulent strain in a cholera-endemic region. ERIC-PCR constitutes a powerful tool for determination of the virulence potential of V. cholerae O1 strains isolated in surveillance programs and for molecular epidemiological investigations.

Potentially pathogenic vibrios associated with mussels from a tropical region on the Atlantic coast of Brazil

Mussels (Perna perna) harvested on the coast of Ubatuba, in three different stations in the State of São Paulo, Brazil, were examined for Vibrio spp. over a 1 year period. The ranges of most probable number (MPN 100 g-1) were: Vibrio alginolyticus (< 3-24,000), V. parahaemolyticus (< 3-24,000), V. fluvialis (< 3-1100), V. cholerae non-O1 (< 3-23), V. furnissii (< 3-30), V. mimicus (< 3-9) and V. vulnificus (< 3-3). The highest incidence was observed for V. alginolyticus (92-100%), followed by V. parahaemolyticus (67-92%), V. fluvialis (34-67%), V. vulnificus (8-17%), V. furnissii (0-17%), V. mimicus (0-17%) and V. cholerae non-O1 (0-8%). Tests for virulence factors were positive in 34.1% of the vibrios in the rabbit ileal loop and 31.7% in the Dean test. Positive results in the Kanagawa test were obtained with 0.51% of V. parahaemolyticus strains. The mean values (MPN 100 g-1) of faecal coliforms in mussels from the three regions varied from 1100 to 44,000, and seawater collected at the same stations gave average values for faecal coliforms in the range 18-3300 MPN 100 ml-1. These results highlight the potential risks of food poisoning associated with raw or undercooked seafood.

Distribution of uidA gene sequences in Escherichia coli isolates in water sources and comparison with the expression of beta-glucuronidase activity in 4-methylumbelliferyl-beta-D-glucuronide media

The uidA gene, which encodes the beta-glucuronidase enzyme, was detected in 97.7% of 435 Escherichia coli isolates from treated and raw water sources by DNA-DNA hybridization; 92.4% of the strains expressed the translational product in 4-methylumbelliferyl-beta-D-glucuronide-containing media after reinoculation. Upon initial isolation from water samples, the minimal medium o-nitrophenyl-beta-D-galactopyranoside-4-methylum-belliferyl -beta-D-glucuronide preparations failed to detect more than 50% of the E. coli isolates that possessed uidA gene. Treated water gave the lowest recovery, with Colilert producing 26% positive samples and Coliquik producing 48% positive samples. There appears to be no relationship between the intensity of the autoradiographic signals of the uidA gene and the expression of beta-glucuronidase activity. Therefore, another variable such as physiological condition of the bacteria could be responsible for the nonexpression of the enzyme activity.

Detection of virulence factors in culturable Escherichia coli isolates from water samples by DNA probes and recovery of toxin-bearing strains in minimal o-nitrophenol-beta-D-galactopyranoside-4-methylumbelliferyl-beta-D-g luc uronide media

A total of 449 Escherichia coli isolates in treated and raw water sources were submitted to DNA-DNA hybridization using seven different DNA probes to detect homology to sequences that code for Shiga-like toxins I and II; heat-stabile and heat-labile toxins, adherence factors EAF and eae, and the fimbrial antigen of entero-hemorrhagic E. coli. Fifty-nine (13%) of the isolates demonstrated homology with one or more specific DNA probes. More than 50% of the isolates in treated water were not recovered in MMO-4-methylumbelliferyl-beta-D-glucuronide media designed for detection of this indicator.

[Bacteriological quality of groundwaters in cemeteries]

Groundwater samples collected by piezometers from three cemeteries in geologically distinct areas of S. Paulo and Santos, Brazil, were analysed in order to determine their hygienic and sanitary conditions. Fecal coliformes, fecal streptococci, sulfite reducer clostridia and Salmonella were searched for the purpose of evaluating sanitary conditions, and total coliforms, heterotrophic bacteria, proteolitic and lipolitic microorganisms for evaluating hygienic conditions. In some samples, nitrate levels were also determined. It was discovered that these waters do not present adequate sanitary and hygienic conditions and that, in some cases, nitrate levels were extremely high (75.7 mg/l). In most samples, higher levels of fecal streptococci and sufite reducer clostridia than fecal coliforms were detected, which seems to show that the two former indicators would be more appropriate for evaluating the sanitary conditions of this kind of water. Salmonella were detected in only one of 44 samples analysed and coliphages in none. In the statistical analysis, the correlation matrix showed significant correlations among three fecal pollution indicators, as well as among anaerobic and aerobic heterotrophs and lipolitic bacteria. A direct relationship between the deterioration of water quality and the geological and hydrogeological conditions of the environment studied was observed. When cemeteries are constructed these conditions should, therefore, be taken into consideration.