Outbreak investigation of foodborne illness among political rally attendees, Cuddalore, Tamil Nadu, India.

In July 2015, we investigated a foodborne illness outbreak in Sithalikuppam and Verupachi villages, Cuddalore district, Tamil Nadu, among the political rally attendees to determine the risk factors for illness. We conducted a retrospective cohort study, calculated risk ratio for the food exposures, and cultured stool specimens. Of 55 rally attendees, we identified 36 (65%) case patients; 32 (89%) had diarrhea and 20 (56%) had vomiting. Median incubation period was 14 h. Eighty-nine percent (32/36) of those who ate lemon rice at dinner had illness compared to 21% (4/19) of those who did not (RR 4.2). Of the six nonattendees who ate leftovers on July 25, all ate only lemon rice and became ill. Stool cultures were negative for Salmonella, Shigella, and Vibrio species. Lemon rice was probably contaminated with enterotoxins such as from Bacillus cereus. Our findings highlighted need for community food safety education and importance of thorough outbreak investigations.

Genotoxicity evaluation of heat shock in gold fish (Carassius auratus).

Genotoxicity evaluation of heat shock was carried out in Carassius auratus. The genotoxicity end points studied were nuclear anomalies (micronucleus assay), chromosomal aberrations, DNA damage (comet assay) and cell proliferation. The heat shock temperatures used were 34 degrees C, 36 degrees C and 38 degrees C. The results demonstrated that heat shock causes the induction of micronucleus at all the three temperature studied. Heat shock also inhibited cell proliferation at 38 degrees C and caused aberrations in the metaphase chromosomes at 34 degrees C and 36 degrees C. Comet assay demonstrated single strand DNA damage at all the three temperatures. The results obtained indicate that heat shock is a genotoxicant.

Laboratory evaluation of bait base for the control of Indian field mouse, Mus booduga (Gray).

Species specific bait evaluation is important for the successful control of rodent populations through rodenticides. Experiments were conducted on the bait preference of Indian field mouse, M. booduga. Results reveal that rice normal grain, rice cracked grain, rice +4% coconut oil and millet +2% coconut oil may be used as effective poison carriers for the Indian field mouse. Additives like oil, sugar and salt did not improve the palatability of bait materials.

Environmental physiology of the mole crab Emerita asiatica, at a power plant discharge area on the east coast of India.

Cage experiments at the discharge area of Madras Atomic Power Station (MAPS) facilitated studies of thermal tolerance in Emerita asiatica. At the laboratory, oxygen consumption at various temperatures and varying salinities was also investigated. In the field 100% mortality of crabs was recorded at the Condenser Cooling Water Pumps (CCWP) discharge site compared to no mortality at the Processed Sea Water Pumps (PSWP) site. This observation implicated temperature as a stress factor at the CCWP outfall, because other factors, including residual chlorine and water velocity, were the same at the PSWP and CCWP sites. Laboratory experiments on tolerance revealed that 38.5 degrees C was lethal to mole crabs. The time taken for 100% mortality decreased as the temperature increased from 35 to 40 degrees C. Oxygen metabolism showed a progressive increase with temperature from 29 to 36 degrees C, and declined at 37 degrees C. The influence of salinity on oxygen consumption was marginal at salinities of 20 to 35 per thousand but, when reduced to 15 per thousand, the oxygen consumption declined. The present study thus indicates that temperature could be the lethal factor, determining the distribution of mole crabs near the power station, where water temperature can exceed 40 degrees C.

Genotoxicity evaluation of pyrazinamide in mice.

Pyrazinamide, an antituberculosis drug, was investigated for genotoxicity in mice, an in vivo rodent system. Three doses (125, 250 and 500 mg/kg bw corresponding to 5, 10 and 20 times the therapeutic dose respectively) were tested. The mitotic index and the frequency of chromosomal aberrations were analysed at three sample times (3, 6 and 24 h) after a single intraperitoneal treatment. The frequency of sperm shape abnormalities was also examined. The mitotic index showed a decrease in drug-treated animals compared with that recorded in the control set. The cells with chromosomal aberrations ranged from 4% to 8%. The maximum frequency of aberrations was found at the 3-h sample time. The frequency of sperm shape abnormalities showed a dose-related increase. These observations suggest pyrazinamide to be a weak genotoxicant at the doses tested.

Effect of toxaphene toxicity on enzyme activity & residue levels in vital organs of guineapig.

Guineapigs exposed to acute and subacute levels of toxaphene revealed a marginal reduction in the body weight. There was a significant inhibition of acetylcholinesterase and ATPases in the brain, liver and kidney. The effect of subacute toxicity of toxaphene resulted in an enhancement of cytochrome P450 and induction of aniline hydroxylase in liver and kidney. Biochemical investigations on the backbone revealed that toxaphene toxicity caused an increase in the calcium content and a decrease in the collagen content significantly. Toxaphene was accumulated more in the liver than in the kidney as reflected by residue studies.

Effects of dimethoate on collagen metabolism in rats.

The effects of three different doses of dimethoate on the collagen metabolism in the tissues of female albino rats were studied by measuring the specific and total activities of 3H-hydroxyproline in the dermal, gingival and uteral collagen fractions and in the urine. Compared to controls, the total activity of 3H-hydroxyproline in the soluble collagen and in the urine at 12 h after the administration of 3H-proline was significantly lower by 44.45 and 58.12 per cent in the higher dose (2.25 mg/100 g body weight) of dimethoate treated groups respectively. The urinary excretion of hydroxyproline and the total activity of urinary 3H-hydroxyproline measured after 28 days of injection of labelled proline were decreased by 45.56 and 32.68 per cent in higher doses of dimethoate treated animals respectively but the excretions of urinary 3H-hydroxyproline were decreased by 6.36 and 2.88 per cent in lower doses of dimethoate (0.56 mg/100 g body weight) treated animals. The results of the present investigation clearly indicate that the synthesis of collagen is decreased in the higher doses of dimethoate treated animals compared to lower doses of dimethoate treated animals. In addition, the rates of catabolism of both soluble and insoluble collagens were decreased in higher doses of dimethoate treated rats. In concludes that the lower doses of dimethoate (0.56 mg) treated rats were less affected than the higher doses of dimethoate (2.25 mg) treated rats.