ABSTRACT
Thuringiensis fractions included two non-toxic fractions [136.000 and 38.000 dalton], two toxic non-specific fractions [68.000 and 25.000 dalton], and two toxic specific fractions for only Ae. Caspius [47.000 and 30.000 dalton]. Fractions of B. Sphaericus include three non-toxic fractions [75.000, 50.000 and 43.000 dalton], two showed very low toxicity with specificity to only Cx. pipiens [134.000 and 70.000 dalton] and two highly toxic fractions with specificity to Cx. pipiens [37.000 and 25.000]
Subject(s)
Bacillus thuringiensis , Culex , Aedes , Mosquito ControlABSTRACT
An organically polluted mosquito breeding water was tested for the presence of bacteriophages which could inhibit the larvicidal activity of B. thuringiensis H-14 and B sphaericus. More than one bacteriophage were isolated which could inhibit the tested bacteria. The sensitivity of the two bacterial species to 12 antibiotics was tested. Two of them, showed no antibacterial action, were selected and considered as antivirus agents in the bacteriophage assays; namely, Amoxycillin and Co-Trimoxazole. Results indicated their antivirus activity as the addition of the antibiotics to the isolated phages could permit normal bacterial growth as well as persistence of larvicidal activity against Culex pipiens larvae
Subject(s)
Culex , Pest Control, BiologicalABSTRACT
Groups of the house fly, Musca domestica sorbens, were fed on sugary solution contaminated with an aflagellated strain of Escherichia coli. Multiplication of this pathogen was detected during one week after the ingestion of E. coli, contaminated food. Bacterial propagation in the fly gut was found to be accompanied by a change of the aflagellated E. coli to the flagellated form. The gaining of flagellae during incubation in the fly gut was found to be stable even after being ingested again by another group of flies. Propagation of E. coli in the fly gut as well as flagellation development could indicate a biological means of transmission of enteric bacteria by M. domestica sorbens
Subject(s)
Insect Vectors , HousefliesABSTRACT
The house fly Musca domestica was tested as a vector transmitting the enteric bacterial pathogens as represented by a standard E. coli strain. The vetorial capacity of the house-fly was estimated as a mechanical transmitter on different external sites as well as for its transmission of the ingested bacteria through feeding behaviour. The achieved results revealed high external contamination densities of the mouth parts followed by the abdomen surface, legs and then wings. A marked increase of the ingested E. coli counts during one week after the ingestion of E. coli contaminated food indicate the propagation of the tested bacterium in the fly gut