Badri Fattal

Survival of Enteroviruses and Bacterial Indicator Organisms in the Sea

ABSTRACT A field study in sewage polluted marine coastal waters indicated that while the concentration of total coliforms, fecal coliforms and fecal streptococci were correlated with the concentrations of enteroviruses, the viruses were more resistant to inactivation by environmental factors than total coliforms and fecal coliforms, but fecal streptococci showed a similar resistance. Frequently enteroviruses could be detected at beaches found satisfactory by coliform standards.

Comparison of adsorption-elution methods for concentration and detection of viruses in water

Abstract A comparative study of various adsorption-elution methods for concentration of viruses seeded into 51. tap water was carried out. The methods were: 1. (1) Aluminum hydroxide precipitation; 2. (2) Adsorption to cellulose nitrate membrane filter and elution with glycine buffer at pH 11.5; 3. (3) Insoluble polyelectrolytes (PE 60); 4. (4) Adsorption to cellulose nitrate membrane filter and elution with 3% beef extract. The aluminum hydroxide precipitation method served as the standard procedure for comparison with our previously published methods. The various methods were compared, using attenuated poliovirus I and enteroviruses recovered from sewage. The results show that the membrane filter elution with 3% beef extract and the PE 60 method provide a good average recovery of 70% and above for both seeded poliovirus and diluted sewage. On the other hand, the membrane filter of elution with glycine buffer at pH 11.5, provides an average recovery of 65–67%.

15 – Control of pathogenic microorganisms in wastewater recycling and reuse in agriculture

This chapter discusses the control of pathogenic microorganisms from the wastewater in agricultural reuse and wastewater treatment technologies. The control measures for agricultural reuse include establishing and enforcing the microbial guidelines for effluent quality; regulation of the types of crops to be irrigated, thereby minimizing the potential for crop contamination by various irrigation techniques; and the treatment of wastewater to an appropriate degree, so as to control the potential health risks from the pathogenic microorganisms in the wastewater stream. The epidemiological evidence of the disease transmission associated with the agricultural use of raw waste water in developing countries indicates that the pathogenic agents may be ranked in the order of declining importance: high risk, lower risk, and least risk. One of the most widely practiced administrative methods for protecting the public health from the risks of uncontrolled wastewater irrigation—particularly of vegetables and salad crops consumed uncooked—is the establishment of guidelines or legally binding standards for the microbial quality of wastewater used for irrigation.

Rates of experimental microbiological contamination of fish exposed to polluted water

Abstract Fish inhabiting fecally polluted bodies of water are often used for human consumption. Such fish can be contaminated by enteric human pathogens and may pose a potential risk to public health. Controlled experiments with 132 fish of 100 g average weight were conducted to evaluate the rate of contamination of various tissues of fish (tilapia hybrids). The fish were exposed to E. coli introduced into the ambient water at concentrations of up to 106 cfu/ml. Additional experiments were conducted with diluted wastewater containing Aeromonas, enterococci, fecal coliform and F+ coliphages. In another experiment poliovirus I was also added. The highest bacterial concentrations were recovered from the digestive tract (DT), some 5–24 h following exposure, with DT levels essentially similar to those in the inoculated water. In the E. coli experiments, geometric mean levels of about 102 cfu/cm2 were recovered from the skin, 26 cfu/g in the spleen and 102 cfu/g in the liver. Most of the muscle samples were not contaminated. Greater contamination was not found under conditions of stress such as high organic load, a water temperature of 37°C or low levels of dissolved oxygen.

Enterovirus types in Israel sewage

Abstract Two methods were used for the isolation and identification of enteroviruses in sewage from various communities in Israel. Out of 489 isolates from sewage at different places by the picked plaque method, 74% were polioviruses, 10% were Coxsackie Type B, Coxsackie A9 or Echo 9 and 16% were Echo or other enterovirus strains. Samples taken from sewage (26 grab samples and 26 gauze pads) were tested for polio and non-polioviruses by a neutralization test. An average of 37% of the daily grab and gauze pad samples were identified as polioviruses.

Wastewater reuse and exposure to Legionella organisms

Eight hundred and fifty-two (852) blood sera were drawn in 1980 and 1981 from populations residing in 30 agricultural settlements (having a total population of 16,240). These sera were tested for the presence of antibodies against 15 different antigens of Legionella species (L. pneumophila serogroups 1–8 and seven other Legionella, i.e. bozemanii, gormanii, micdadei, jordanis, dumoffii, longbeacheae and oakridgensis). The results indicate a significant (P < 0.02) excess in the percentage of sera positive for L. pneumophila (serogroups 1–8) among sewage and non-sewage irrigation and fish pond workers as compared to the control group (4.5% vs 1.5%). For the other Legionella species, there was no difference among the above groups. The isolation of L. pneumophila serogroup 4 and five organisms resembling Legionella spp from one oxidation pond used for irrigation strengthens the seroepidemiological findings.

Distribution of mycobacteria in different types of water in Israel.

Abstract Seventy five water samples were collected from 26 sampling sites in Israel and were examined for the presence of atypical mycobacteria. Different species of mycobacteria which are normally widely distributed in the environment were found in sixteen of the samples with the number of wastewater positives twofold higher than that found in the nonwastewater. Seven species of atypical mycobacteria some of which can be pathogenic to man were isolated; three were found only in nonwastewater, one in wastewater and the remainder were detected in both. The most common species were M. nonchromogenicum, M. gordonae and M. terrae.

Evaluation of gauze pad method to recover viruses from water

Abstract Field studies using the gauze pad method were compared with the grab sample method. It was found that the gauze pad proved to be more effective, for detecting enterovirus, than two-liter volume grab samples, taken from the same sewage stream and concentrated by the phase separation method. No advantage was found in keeping the pad immersed longer than 24 h in the water stream being tested. On the other hand, laboratory experiments for evaluation of gauze pads show that the recovery efficiency for concentration of viruses with gauze pads from water is very low and dependent on sample volume—the larger the volume the lower the efficiency.

Bathers as a possible source of contamination for swimming‐associated illness at marine bathing beaches

The results of a prospective, follow‐up epidemiological study conducted at three Israeli coastal beaches in 1983 showed that enteric, respiratory and ear symptomatology were higher among swimmers than nonswimmers, especially for young children. The enterococcus levels and the swimming‐associated rates for enteric and respiratory symptoms at one of the beaches (Gordon) were at least twice those at another beach (Rishon Lezion). The higher swimming‐associated symptom rates at Gordon Beach, however, were largely attributable to individuals who swam on Saturdays, which are non‐working days in Israel, as opposed to Fridays and Sundays. The absence of extrinsic sources of pollution, the restricted water exchange due to horizontal surf‐breakers, the greater bather density and higher indicator levels (including those of Staphylococcus aureus) on Saturdays and the better correlation of S. aureus than enterococcus (or Escherichia cofi) levels to swimming‐associated enteric and respiratory symptoms, suggests that co...

Evaluation of the false-positive enteroviral plaque phenomenon occurring in sewage samples

Abstract Several laboratories monitoring for enteroviruses in wastewater have reported a high percentage of false-positive viral plaques. This article discusses the issue of possible false evaluation of viral plaque determinations in wastewater, and reviews the preventive measures taken in several wastewater studies conducted in our laboratory, which minimized this phenomenon. Our results showed that with the procedures described, no false-positive plaques were found.