A sensitive and specific RT-nested PCR coupled with an ELISA detection system for detecting Newcastle disease virus is described. Two nested pairs of primer which were highly specific to all the three different pathotypes of NDV were designed from the consensus fusion gene sequence. No cross-reactions with other avian infectious agents such as infectious bronchitis virus, infectious bursal disease virus, influenza virus, and fowl pox virus were observed. Based on agarose electrophoresis detection, the RT-nested PCR was about 100 times more sensitive compared to that of a non-nested RT-PCR. To facilitate the detection of the PCR product, an ELISA detection method was then developed to detect the amplified PCR products and it was shown to be ten times more sensitive than gel electrophoresis. The efficacy of the nested PCR-ELISA was also compared with the conventional NDV detection method (HA test) and non-nested RT-PCR by testing against a total of 35 tissue specimens collected from ND-symptomatic chickens. The RT-nested PCR ELISA found NDV positive in 21 (60%) tissue specimens, while only eight (22.9%) and two (5.7%) out of 35 tissue specimens were tested NDV positive by both the non-nested RT-PCR and conventional HA test, respectively. Due to its high sensitivity for the detection of NDV from tissue specimens, this PCR-ELISA based diagnostic test may be useful for screening large number of samples.
Previously we have shown that avian leukosis virus subgroup J (ALV-J) might be present in chicken flocks from Malaysia based on serological study and also on detection of tissue samples with myelocytic infiltration. In this study, the polymerase chain reaction was used to detect ALV-J sequences from archived frozen samples. Out of 21 tissue samples examined, 16 samples were positive for proviral DNA and four samples for ALV-J RNA. However, only nine samples were found positive for myelocytic infiltration. A total of 465 base pairs equivalent to positions 5305 to 5769 of HPRS-103 from each of the viral RNA positive samples were characterized. Sequence analysis indicated that the samples showed high identity (95.9 to 98.2%) and were close to HPRS-103 with identities between 97.4 and 99.3%. This study indicates that ALV-J-specific sequences can be detected by polymerase chain reaction from frozen tissue samples with and without myelocytic infiltration.
Two Malaysian infectious bronchitis virus isolates, MH5365/95 and V9/04 were characterized based on sequence and phylogenetic analyses of S1, S2, M, and N genes. Nucleotide sequence alignments revealed many point mutations, short deletions, and insertions in S1 region of both IBV isolates. Phylogenetic analysis of S1 gene and sequences analysis of M gene indicated that MH5365/95 and V9/04 belong to non-Massachusetts strain. However, both isolates share only 77% identity. Analysis based on S1 gene showed that MH5365/95 shared more than 87% identity to several Chinese strains. Meanwhile, V9/04 showed only 67-77% identity to all the previously studied IBV strains included in this study suggesting it is a variant of IBV isolate that is unique to Malaysia. Phylogenetic analysis suggests, although both isolates were isolated 10 years apart from different states in Malaysia, they shared a common origin. Analysis based on S2 and N genes indicated that both strains are highly related to each other, and there are fewer mutations which occurred in the respective genes.
We isolated and characterized Nipah virus (NiV) from Pteropus vampyrus bats, the putative reservoir for the 1998 outbreak in Malaysia, and provide evidence of viral recrudescence. This isolate is monophyletic with previous NiVs in combined analysis, and the nucleocapsid gene phylogeny species.
This study aimed to describe the transmission dynamics, the serological and virus excretion patterns of Nipah virus (NiV) in Pteropus vampyrus bats. Bats in captivity were sampled every 7-21 days over a 1-year period. The data revealed five NiV serological patterns categorized as high and low positives, waning, decreasing and increasing, and negative in these individuals. The findings strongly suggest that NiV circulates in wild bat populations and that antibody could be maintained for long periods. The study also found that pup and juvenile bats from seropositive dams tested seropositive, indicating that maternal antibodies against NiV are transmitted passively, and in this study population may last up to 14 months. NiV was isolated from the urine of one bat, and within a few weeks, two other seronegative bats seroconverted. Based on the temporal cluster of seroconversion, we strongly believe that the NiV isolated was recrudesced and then transmitted horizontally between bats during the study period.
In the title compound, C(27)H(20)BrNO(3), two intra-molecular C-H⋯O hydrogen bonds both form S(6) rings. The pyrrolidine ring adopts a twisted conformation about the C-C bond bearing the indane ring systems. The other two five-membered rings within the indane systems are in shallow envelope conformations, with the spiro C atoms as the flap atoms. The mean plane of the pyrrolidine ring [maximum deviation = 0.275 (1) Å] makes dihedral angles of 65.25 (7), 78.33 (6) and 75.25 (6)° with the bromo-substituted benzene ring and the mean planes of the mono- and dioxo-substituted indane rings, respectively. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯N hydrogen bonds into a three-dimensional network. In addition, C-H⋯π inter-actions are observed.
In the title compound, C(10)H(11)N(5)O, the triazine ring forms a dihedral angle of 10.37 (4)° with the benzene ring. In the crystal, adjacent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds, forming an inversion dimer with an R(2) (2)(8) ring motif. The dimers are further connected via N-H⋯O and N-H⋯N hydrogen bonds, resulting in a three-dimensional network.
The asymmetric unit of the title compound, C(27)H(32)N(4)O(4)·H(2)O, contains two independent benzimidazole-5-carboxyl-ate mol-ecules and two water mol-ecules. In both main mol-ecules, the pyrrolidine rings are in an envelope conformation with a methyl-ene C atom as the flap. The morpholine rings adopt chair conformations. Both benzimidazole rings are essentially planar, with maximum deviations of 0.008 (1) Å, and form dihedral angles of 37.65 (6) and 45.44 (6)° with the benzene rings. In one mol-ecule, an intra-molecular C-H⋯O hydrogen bond forms an S(7) ring motif. In the crystal, O-H⋯O and O-H⋯N hydrogen bonds connect pairs of main mol-ecules and pairs of water mol-ecules into two independent centrosymmetric four-compoment aggregates. These aggregates are connect by C-H⋯O hydrogen bonds leading to the formation of a three-dimensional network, which is stabilized by C-H⋯π interactions.
The asymmetric unit of the title compound, 2C(10)H(11)N(5)O·C(6)H(10)O(4), consists of a 2,4-diamino-6-(4-meth-oxy-phen-yl)-1,3,5-triazine mol-ecule and one-half mol-ecule of adipic acid which lies about an inversion center. The triazine ring makes a dihedral angle of 12.89 (4)° with the adjacent benzene ring. In the crystal, the components are linked by N-H⋯O and O-H⋯N hydrogen bonds, thus generating a centrosymmetric 2 + 1 unit of triazine and adipic acid mol-ecules with R(2) (2)(8) motifs. The triazine mol-ecules are connected to each other by N-H⋯N hydrogen bonds, forming an R(2) (2)(8) motif and a supra-molecular ribbon along the c axis. The 2 + 1 units and the supra-molecular ribbons are further inter-linked by weak N-H⋯O, C-H⋯O and C-H⋯π inter-actions, resulting in a three-dimensional network.
The anion of the title salt, C(6)H(9)N(2) (+)·C(6)H(4)NO(3) (-), undergoes an enol-to-keto tautomerism during the crystallization. In the crystal structure, the cation and anion are held together by a relatively short N-H⋯O hydrogen bond, and the two anions are further connected to each other by a pair of N-H⋯O hydrogen bonds with an R(2) (2)(8) ring motif, thus forming a centrosymmetric 2 + 2 aggregate. The aggregates are further linked through weak N-H⋯O and C-H⋯O hydrogen bonds, resulting a three-dimensional network.
In the 2-amino-benzoate anion of the title salt, C(6)H(9)N(2) (+)·C(7)H(6)NO(2) (-), an intra-molecular N-H⋯O hydrogen bond is observed. The dihedral angle between the ring and the CO(2) group is 8.41 (13)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms via a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. The ion pairs are further connected via N-H⋯O hydrogen bonds, resulting in a donor-donor-acceptor-acceptor (DDAA) array of quadruple hydrogen bonds. The crystal structure also features a weak N-H⋯O hydrogen bond and a C-H⋯π inter-action, resulting in a three-dimensional network.
The 3-chloro-benzoate anion of the title salt, C(6)H(9)N(2) (+)·C(7)H(4)ClO(2) (-), is nearly planar with a dihedral angle of 2.44 (13)° between the benzene ring and the carboxyl-ate group. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds with an R(2) (2)(8) ring motif, forming an approximately planar ion pair with a dihedral angle of 7.92 (5)° between the pyridinium and benzene rings. The ion pairs are further connected via N-H⋯O and C-H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane.
The asymmetric unit of the title compound, 2C5H6ClN3O·C4H6O4, consists of one 4-chloro-6-meth-oxy-pyrimidin-2-amine mol-ecule and one half-mol-ecule of succinic acid which lies about an inversion centre. In the crystal, the acid and base mol-ecules are linked through N-H⋯O and O-H⋯N hydrogen bonds, forming a tape along [1-10] in which R2(2)(8) and R4(2)(8) hydrogen-bond motifs are observed. The tapes are further inter-linked through a pair of C-H⋯O hydrogen bonds into a sheet parallel to (11-2).
In the title salt, 2C4H6ClN4(+)·C4H2O4(2-), the complete fumarate dianion is generated by crystallographic inversion symmetry. The cation is essentially planar, with a maximum deviation of 0.018 (1) Å. In the anion, the carboxyl-ate group is twisted slightly away from the attached plane, the dihedral angle between the carboxyl-ate and (E)-but-2-ene planes being 12.78 (13)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms of the anion via a pair of N-H⋯O hydrogen bonds, forming an R2(2)(8) ring motif. In addition, another type of R2(2)(8) motif is formed by centrosymmetrically related pyrimidinium cations via N-H⋯N hydrogen bonds. These two combined motifs form a heterotetra-mer. The crystal structure is further stabilized by stong N-H⋯O, N-H⋯Cl and weak C-H⋯O hydrogen bonds, resulting a three-dimensional network.
In the title salt, C6H9N2(+)·C2F3O2(-), the F atoms of the anion are disordered over two sets of sites, with refined occupancies in a ratio of 0.505 (17):0.495 (17). In the crystal, cations and anions are linked via N-H⋯O hydrogen bonds, forming R2(2)(8) ring motifs. The ionic units are linked into a two-dimensional network parallel to (100) by N-H⋯O and weak C-H⋯O hydrogen bonds. The crystal structure is further stabilized by weak C-H⋯F hydrogen bonds, resulting in a three-dimensional network.
The title compound, C5H6ClN3O, is essentially planar with a maximum deviation of 0.0256 (11) Å for all non-H atoms. In the crystal, adjacent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds, forming an inversion dimer with an R2(2)(8) ring motif. The dimers are further linked via N-H⋯O hydrogen bonds into an undulating sheet structure parallel to the bc plane.
The benzoic acid mol-ecule of the title compound, C4H5ClN4·C7H6O2, is approximately planar, with a dihedral angle of 1.28 (9)° between the carb-oxy group and the benzene ring. In the crystal, two acid and two base mol-ecules are linked through N-H⋯O and O-H⋯N hydrogen bonds, forming a centrosymmetric 2 + 2 unit with R2(2)(8) and R4(2)(8) motifs. These units are further linked through a pair of N-H⋯N hydrogen bonds into a tape structure along [1-20]. The crystal structure also features weak π-π [centroid-centroid distance = 3.5984 (11) Å] and C-H⋯π inter-actions.
The base mol-ecule of the title co-crystal, C7H10N2O2S·C7H6O3, is essentially planar, with a maximum deviation of 0.0806 (14) Å for all non-H atoms. The acid mol-ecule is also nearly planar, with a dihedral angle of 8.12 (14)° between the benzene ring and the carb-oxy group. In the crystal, the acid mol-ecules form an inversion dimer through a pair of O-H⋯O hydrogen bonds with an R2(2)(8) ring motif. The pyrimidine mol-ecules are linked on both sides of the dimer into a heterotetra-mer via O-H⋯N and C-H⋯O hydrogen bonds with R2(2)(8) ring motifs. The heterotetra-mers are further linked by weak C-H⋯O hydrogen bonds, forming a tape structure along [1-10].
In the 4-meth-oxy-quinoline-2-carboxyl-ate anion of the title salt, C5H8N3(+)·C11H8NO3(-), the dihedral angle between the quinoline ring system and the carboxyl-ate group is 16.54 (15)°. In the crystal, the cations and anions are linked via N-H⋯O and N-H⋯N hydrogen bonds, forming a centrosymmetric 2 + 2 aggregate with R2(2)(9) and R4(2)(8) ring motifs. These units are further connected via N-H⋯O hydrogen bonds into a layer parallel to the bc plane. The crystal structure is also stabilized by weak C-H⋯O hydrogen bonds and π-π inter-actions between pyridine rings [centroid-centroid distance = 3.5886 (8) Å] and between pyridine and benzene rings [centroid-centroid distance = 3.6328 (8) Å].
In the 5-chloro-salicylate anion of the title salt, C6H9N2(+)·C7H4ClO3(-), an intra-molecular O-H⋯O hydrogen bond with an S(6) graph-set motif is observed and the dihedral angle between the benzene ring and the -CO2 group is 1.6 (6)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl-ate O atoms via a pair of N-H⋯O hydrogen bonds, forming an R2(2)(8) ring motif. The crystal structure also features N-H⋯O and weak C-H⋯O inter-actions, resulting in a layer parallel to (10-1).