Deltamethrin resistance in south Indian isolates of Rhipicephalus (Boophilus) microplus.

The present communication deals with the detection and characterization of deltamethrin resistance in tick populations using biological (larval packet test), biochemical (esterase enzyme assay) and molecular assays. Ticks were collected from cattle farms of Korutla, Telangana (KOR), Mehboob Nagar, Telangana (MBN), Nagpur, Maharashtra (NAG), Parbani, Maharashtra (PBN), Madhavaram, Tamil Nadu (MAD), Cuddalore, Tamil Nadu (CUD), Sakhleshpur, Karnataka (SAK) and Buvenduvella, Karnataka (BUV). Out of eight field isolates, seven were identified as Rhipicephalus (Boophilus) microplus while one isolate (CUD) was identified as R. (B.) annulatus. The LC50 values and resistance factors (RF) of field isolates were assessed by larval packet test (LPT). RF values of two isolates viz., Korutla and Parbhani (KOR, PAR) were close to that of reference susceptible isolate. R. (B.) microplus isolate from Nagpur (NAG) and Sakleshpur (SAK) revealed slightly higher RF values (6.42 and 4.51). They revealed slightly elevated esterase enzyme activity too. Other isolates did not reveal higher values for RF or esterase activity. Previously identified mutations conferring synthetic pyrethroid resistance in R. (B.) microplus populations were analysed by sequencing the mutation flanking regions of the carboxyl esterase and the sodium channel genes (domain III S6 and domain II S4-5 linker region). However, these point mutations were not detected in the field isolates. The results of the present study revealed that low levels of synthetic pyrethroid resistance had developed in field populations of ticks of southern India.

Phylogenetic analysis of bovine Theileria spp. isolated in south India.

The objective of the present study is to determine the phylogenetic position of the Theileria organisms in blood of cattle of southern India using molecular tools. Theileria annulata (Namakkal isolate, Tamil Nadu) and three Theileria field isolates (free of T. annulata) from Wayanad, Kerala (Wayanad 1, 2, 3) were used. The small subunit ribosomal RNA (SSU rRNA) and major piroplasm surface protein (MPSP) gene products were cloned, sequenced and the phylogenetic tree constructed. SSU rRNA gene of Wayanad 1 isolate (JQ706077) revealed maximum identity with Theileria velifera or Theileria cervi. The phylogenetic tree constructed based on SSU rRNA genes revealed that Wayanad 1 isolate belonged to a new type which share common ancestor with all the other theilerial species while Wayanad 2 and 3 isolates (JX294459, JX294460) were close to types A and C respectively. Based on MPSP gene sequences, Wayanad 2 and 3 (JQ706078, JX648208) isolates belonged to Type 1 and 3 (Chitose) respectively. When, the previously reported MPSP type 7 is also considered from the same study area, Theileria orientalis types 1, 3 and 7 are observed in south India. SSU rRNA sequence of South Indian T. annulata (JX294461) showed a maximum identity with Asian isolates while the Tams1 merozoite surface antigen (MSA) gene (JX648210) showed maximum identity with north Indian isolate.

Paracoccus niistensis sp. nov., isolated from forest soil, India.

A Gram-negative, non-motile, catalase-positive and oxidase-positive, aerobic bacterium designated as NII-0918(T) was isolated from soil sample in Western ghat forest, India. 16S rRNA gene sequence analysis showed that strain NII-0918(T) belongs to the subclass α-Proteobacteria, being related to the genus Paracoccus, and sharing highest sequence similarity with Paracoccus chinensis NBRC 104937(T) (99.4%), Paracoccus marinus NBRC 100640(T) (97.3%), Paracoccus koreensis Ch05(T) (97.1%) and Paracoccus kondratievae GB(T) (97.0%). Other members of Paracoccus showed below 97.0% similarity. The DNA-DNA hybridization values between these four strains and NII-0918(T) were 44.7, 28, 32 and 41%, respectively. The major fatty acids of strain NII-0918(T) were summed feature 7 (C18:1 ω7c/ω 9t/ω 12t) (83.0%) and C18:0 (12.5%). Ubiquinone Q-10 was detected as the major respiratory quinone. The G+C content of genomic DNA of NII-0918(T) was 66.6 mol%. On the basis of physiological, morphological, chemotaxonomical and DNA-DNA hybridization data, it is proposed that strain NII-0918(T) should be placed as a novel species, for which we propose Paracoccus niistensis sp. nov. The type strain is NII-0918(T) (CCTCC AA 209055(T) = NCIM 5340(T) = KCTC 22789(T)).

Isolation and characterization of novel plant growth promoting Micrococcus sp NII-0909 and its interaction with cowpea.

A phosphate-solubilizing bacterial strain NII-0909 isolated from the Western ghat forest soil in India was identified as Micrococcus sp on the basis of phenotypic characteristics, carbon source utilization pattern, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The strain exhibited the plant growth-promoting attributes of phosphate solubilization, auxin production, 1-aminocyclopropane-1-carboxylate deaminase activity, and siderophore production. It was able to solubilize (122.4µg of Ca(3)PO(4) ml(-1)), and produce IAA (109µgml(-1)) at 30°C. P-solubilizing activity of the strain NII-0909 was associated with the release of organic acids and a drop in the pH of the NBRIP medium. HPLC analysis detected two organic acids in the course of P-solubilization. A significant increase in the growth of cow pea was recorded for inoculations under controlled conditions. Scanning electron microscopic study revealed the root colonization of strain on cow pea seedlings. These results demonstrate that isolates NII-0909 has the promising PGPR attributes to be develop as a biofertilizer to enhance soil fertility and promote the plant growth.

Pontibacter niistensis sp. nov., isolated from forest soil.

A Gram-negative, rod-shaped bacterial strain, NII-0905(T) [corrected], that was motile by gliding was isolated from soil of a dense forest collected from the Western Ghats of India and its taxonomic position was established. Strain NII-0905(T) [corrected] contained MK-7 as the major menaquinone and anteiso-C(17 : 0), anteiso-C(15 : 0), iso-C(16 : 0) and iso-C(15 : 0) as the major cellular fatty acids. The DNA G+C content of strain NII-0905(T) [corrected] was 51.47 mol%. 16S rRNA gene sequence-based phylogenetic analysis confirmed the placement of strain NII-0905(T) [corrected] in the genus Pontibacter and strain NII-0905(T) [corrected] exhibited 93.9-96.3 % 16S rRNA sequence similarity with type strains of species of the genus Pontibacter. On the basis of genotypic and phenotypic evidence, strain NII-0905(T) [corrected] is considered to represent a novel species of the genus Pontibacter, for which the name Pontibacter niistensis sp. nov. is proposed. The type strain is NII-0905(T) [corrected](=NCIM 5339(T) =CCTCC AA 209057(T)).

Isolation and characterization of plant growth promoting bacteria from non-rhizospheric soil and their effect on cowpea (Vigna unguiculata (L.) Walp.) seedling growth.

The efficacy of four potential phosphate solubilizing Enterobacter isolated from non-rhizospheric soil in Western ghat forest in India. Plant growth promoting ability of these isolates was evaluated in cowpea. All are gram negative, rod shaped, 0.8-1.6 mm in size, and psychrotrophic in nature, grow from 5 to 40°C (optimum temp. 28 ± 2°C). All isolates exhibits growth at a wide range of pH 6-12, optimum at pH 7.0 and tolerates up to 7% (w/v) salt concentration. 16S rRNA gene sequencing reveals the confirmation of isolates to Enterobacter aerogenes sp. (NII-0907 and NII-0929), Enterobacter cloacae subsp. cloacae sp. (NII-0931) and Enterobacter asburiae sp. (NII-0934) with which they share >99% sequence similarity. Under in vitro conditions, all the four isolates were found to produce indole acetic acid, P-solubilization and hydrogen cyanide. The P-solubilizing activity coincided with a concomitant decrease in pH of the medium (pH 7.0-<3.0). The plant growth promotion properties were demonstrated through a cow pea (Vigna unguiculata (L.) walp) based bioassay under greenhouse conditions. Although the bacterial inoculation was found to result in significant increment in root, shoot and biomass and it stimulated bacterial counts in the rhizosphere. Hence, these isolates can further formulated and used for field application.

Isolation and characterization of plant growth-promoting strain Pantoea NII-186. From Western Ghat forest soil, India.

AIMS: To isolate plant growth-promoting bacterium from Western Ghat forests in India. METHODS AND RESULTS: A Gram-negative, rod shaped, cream white coloured strain Pantoea NII-186 isolated from Western Ghat soil sample. The taxonomic position of the bacterium was confirmed by sequencing of 16S rRNA and phylogenetic analysis. A strain grew at a wide range of temperature ranging from 5-40 degrees C, but optimum growth was observed at 28-30 degrees C. It showed multiple plant growth-promoting attributes such as phosphate solubilization activity, indole acetic acid (IAA) production, siderophore production and HCN production. It was able to solubilize (28 microg of Ca(3)PO(4) ml(-1) day(-1)), and produce IAA (59 microg) at 28 degrees C. The solubilization of insoluble phosphate was associates with a drop in the pH of the culture medium. Pantoea sp. NII-186 tolerate to different environmental stresses like 5-40 degrees C, 0-7% salt concentration and 4-12 pH range. CONCLUSIONS: The 16S rRNA gene sequence confirmed that the isolate NII-186 was belongs to Pantoea genus and showed considerable differences in physiological properties with previously reported species of this genus. Isolate NII-186 possessed multiple attributes of plant growth-promoting activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Hence in the context it is proposed that Pantoea sp. NII-186, could be deployed as an inoculant to attain the desired plant growth-promoting activity in agricultural environment.