Methanolic extract of Hemidesmus indicus root augments the antibacterial and antibiofilm activity of amoxicillin and clindamycin against methicillin-resistant Staphylococcus aureus of bovine origin.

The present study evaluated the antibacterial and antibiofilm activity of methanolic extract of Hemidesmus indicus root (MHIR) in combination with amoxicillin and clindamycin against biofilm-forming methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk samples of mastitic cows. Microdilution susceptibility testing and microtitre plate assays were used to evaluate the in vitro efficacy of MHIR and antibiotic combinations against MRSA (n = 12). Furthermore, in vitro findings were validated in a murine model. Minimum inhibitory concentration and minimum biofilm inhibitory concentration of amoxicillin and clindamycin in combination with MHIR were significantly (P < 0·05) lower than when used alone against MRSA. In terms of antibacterial activity, MHIR showed additive interaction (fractional inhibitory concentrationindex >0·5-4) with amoxicillin and clindamycin against all the MRSA isolates, whereas MHIR synergizes (fractional biofilm inhibitory concentrationindex ≤0·5) the antibiofilm activity of amoxicillin and clindamycin against 58·33% and 83·33% of the MRSA isolates respectively. Amoxicillin/clindamycin in combination with MHIR significantly (P < 0·05) reduced disease activity score, and bacterial load and Gram-positive spots in kidney and liver of MRSA-infected mice. The combined efficacy of MHIR and amoxicillin/clindamycin was comparable to clindamycin alone but superior to amoxicillin alone. Hence, the combination of MHIR with amoxicillin/clindamycin is advocated in the treatment of MRSA-associated infections.

DEVELOPMENT OF AN ALGORITHM TO ESTIMATE EYE LENS DOSE IN TERMS OF OPERATIONAL QUANTITY Hp(3) USING HEAD TLD BADGE.

In view of the recommendations of International Commission on Radiological Protection for reduction of the occupational annual dose limit for eye lens from 150 mSv to 20 mSv/y, questions have been raised on the adequacy of monitoring for the quantities Hp(10) and Hp(0.07). As an immediate requirement, in the present situation, where there is no exclusive eye lens dosemeter in India, the existing chest TLD badge was modified to be used as head badge (head dosemeter) by including a strap to enable wearing on the forehead. In order to estimate the eye lens dose in terms of the operational quantity Hp(3), the prevalent algorithm of chest badge was also modified. The modified algorithm was applied to estimate Hp(3) for dosemeters irradiated to various beta and photon radiations including mixtures. The Q values (estimated/delivered dose equivalent) were found to be within ±20% for most of the photon beams.

Development of an algorithm for evaluating personal doses due to photon fields in terms of operational quantities for TLD badge system in India.

In order to evaluate and report the personal doses in terms of personal dose equivalent, the performance of the CaSO(4):Dy based thermoluminescence dosemeter (TLD) badge used for countrywide personnel monitoring in India is investigated using monoenergetic and narrow spectrum radiation qualities equivalent to those given in ISO standards. Algorithms suitable for evaluating H(p)(10) and H(p)(0.07) within +/- 30 % are developed from the responses of dosemeter elements/discs under different filters for normal as well as angular irradiation conditions using these beams. The algorithm is tested for TLD badges irradiated to mixtures of low- and high-energy ((137)Cs) beams in various proportions. The paper concludes with the results of test of algorithm by evaluation of badges used in the IAEA/RCA intercomparison studies and discussion on inherent limitations.

Abnormal anther development and high sporopollenin synthesis in benzotriazole treated male sterile Helianthus annuus L.

Foliar application of 1.5% benzotriazole induced 100% pollen sterility in H. annuus. Pollen abortion in treated plants was mainly associated with abnormal behaviour of tapetum. A limited number of anther locule showed early degeneration of tapetum followed by disintegration of sporogenous tissues. On the other hand, some locules showed normal development of tapetum at initial stages. However, this tapetum exhibited degenerated and non-functional cell organelles. In both these situations tapetum failed to provide proper nourishment to developing microspores. The ultrastructure of both tapetum and microspores is different from that of control material with irregularities of exine deposition, endopolyploidy of tapetal nuclei and an alteration of organelle composition being correlated with sterility. Pollen grains thus developed were devoid of nucleus and cell organelles and were complete sterile.

Molluscicidal activity of Punica granatum bark and Canna indica root

The molluscicidal activity of Punica granatum Linn. (Punicaceae) and Canna indica Linn. (Cannaceae) against the snail Lymnaea acuminata was studied. The molluscicidal activity of P. granatum bark and C. indica root was found to be both time and dose dependent. The toxicity of P. granatum bark was more pronounced than that of C. indica. The 24 h LC50 of the column-purified root of C. indica was 6.54 mg/l whereas that of the column-purified bark of P. granatum was 4.39 mg/l. The ethanol extract of P. granatum (24 h LC50: 22.42 mg/l) was more effective than the ethanol extract of C. indica (24 h LC50: 55.65 mg/l) in killing the test animals. P. granatum and C. indica may be used as potent molluscicides since the concentrations used to kill the snails were not toxic for the fish Colisa fasciatus, which shares the same habitat with the snail L. acuminata

Molluscicidal activity of Punica granatum bark and Canna indica root.

The molluscicidal activity of Punica granatum Linn. (Punicaceae) and Canna indica Linn. (Cannaceae) against the snail Lymnaea acuminata was studied. The molluscicidal activity of P. granatum bark and C. indica root was found to be both time and dose dependent. The toxicity of P. granatum bark was more pronounced than that of C. indica. The 24 h LC(50) of the column-purified root of C. indica was 6.54 mg/l whereas that of the column-purified bark of P. granatum was 4.39 mg/l. The ethanol extract of P. granatum (24 h LC(50): 22.42 mg/l) was more effective than the ethanol extract of C. indica (24 h LC(50): 55.65 mg/l) in killing the test animals. P. granatum and C. indica may be used as potent molluscicides since the concentrations used to kill the snails were not toxic for the fish Colisa fasciatus, which shares the same habitat with the snail L. acuminata.