[Isolation of free-living amoebas from bottled mineral water]

Chemical, microbial and physical evaluation of commercial bottled waters in greater Houston area of Texas

Due to the increased demand and consumption of bottled water in the United States, there has been a growing concern about the quality of this product. Retail outlets sell local as well as imported bottled water to consumers. Three bottles for each of 35 different brands of bottled water were randomly collected from local grocery stores in the greater Houston area. Out of the 35 different brands, 16 were designated as spring water, 11 were purified and/or fortified tap water, 5 were carbonated water and 3 were distilled water. Chemical, microbial and physical properties of all samples were evaluated including pH, conductivity, bacteria counts, anion concentration, trace metal concentration, heavy metal and volatile organics concentration were determined in all samples. Inductively coupled plasma/mass spectrometry (ICPMS) was used for elemental analysis, gas chromatography with electron capture detector (GCECD) as well as gas chromatography mass spectrometry (GCMS) were used for analysis of volatile organics, ion chromatography (IC) and selective ion electrodes were used for the analysis of anions. Bacterial identification was performed using the Biolog software (Biolog, Inc., Hayward, Ca, USA). The results obtained were compared with guidelines of drinking water recommended by the International Bottled Water Association (IBWA), United States Food and Drug Administration (FDA), United States Environmental Protection Agency (EPA) and the World Health Organization (WHO) drinking water standard. The majority of the analyzed chemicals were below their respective drinking water standards for maximum admissible concentrations (MAC). Volatile organic chemicals were found to be below detection limits. Four of the 35 brands of the bottled water samples analyzed were found to be contaminated with bacteria.

Microbial quality of domestic and imported brands of bottled water in Trinidad

A cross-sectional study was conducted to determine the microbial quality of domestic and imported brands of bottled water available in Trinidad, purchased from six geographical regions in Trinidad, and representing the whole island. A sample size of 344 bottles of water was determined by using a precision rate of 2% and a Type 1 error of 5%. The membrane filter technique was used with cultures grown on m-Endo agar and m-FC agar for total coliforms and thermotolerant coliforms, respectively. Aerobic plate count (APC) was determined on nutrient agar; Pseudomonas aeruginosa was detected on MacConkey agar, Escherichia coli was isolated on eosin methylene blue (EMB) and Salmonella spp. was assayed by using standard methods. Of the 344 water samples tested, 262 (76.2%) and 82 (23.8%) were domestic and imported brands, respectively. Eighteen (5.2%) of the 344 samples contained coliforms with a mean count of 0.88+/-6.38 coliforms per 100 ml, while 5 (1.5%) samples contained E. coli. The prevalence of total coliforms in domestic brands of bottled water was 6.9% (18 of 262) as compared with 0.0% (0 of 82) detected in imported brands. The difference was statistically significant (p=0.004). Similarly, the prevalence of aerobic bacteria in domestic brands of bottled water (33.6%) was significantly higher (p=0.001) than was found in imported brands (14.8%). Twenty-six (7.6%) of the total samples of water contained Pseudomonas species, but all were negative for thermotolerant coliforms and Salmonella spp. It was concluded that based on the recommended zero tolerance for coliforms in potable water, 5% of bottled water sold in Trinidad could be considered unfit for human consumption.

[Free-living amoeba in the human intestine. Evidences of parasitism]

Foram cultivadas fezes de 620 indivíduos para a pesquisa de amebas de vida livre, sendo 514 pacientes do Hospital Universitário Pedro Ernesto (UERJ) e 106 crianças e adultos de um orfanato. Foram positivas 70 amostras (11,2%) sendo 55 provenientes de pacientes do HU-UERJ e 15 de internos do orfanato. Foram isoladas 60 amostras de Acanthamoeba, 6 de Vahlkampfia, 5 de Hartmannella e 1 Echinamoeba. Alguns indivíduos tiveram cultura de fezes repetidamente positiva para Acanthamoeba durante dois meses de observação. Das amostras de Acanthamoeba isoladas, 28 foram inoculadas em camundongos por via intranasal, tendo sido reisoladas 16 (57,1%) amostras à partir de cérebro e (ou) pulmões dos animais. O estudo histopatológico demonstrou processo inflamatório agudo com presença de polimorfonucleares e amebas no cérebro e pulmões de alguns animais. O encontro de amostras patogênicas em fezes humanas reforça a hipótese do eventual desenvolvimento, em indivíduos portadores, de meningoencefalite amebiana granulomatosa, como infecção oportunística de origem endógena.