Fig. 1.
Map showing the area of sample collection in two provinces in the northeastern region of Thailand, consisting of Nongkhai (NK) and Maha Sarakham (MK)
Fig. 2.
Plasmodium spp. infections in erythrocytes of backyard ducks, turkeys and geese (indicated by arrows). (A) Plasmodium sp.; (B) Plasmodium gallinaceum; (C) Plasmodium gallinaceum; (D) Plasmodium juxtanucleare. Parasite species were identified by DNA sequencing
Table 1.
Prevalence of Plasmodium spp. infections in backyard poultry
| Locations (Provinces) | Host | Prevalence of Plasmodium spp. | Plasmodium species (n) | ||
|---|---|---|---|---|---|
| Common name | Scientific name | Microscopic examination (%) | PCR examination (%) | ||
| Nongkhai | Domestic duck | Anas platyrhynchos domesticus | 1/30 (3.3) | 4/30 (13.3) | Plasmodium sp. (4) Plasmodium sp. (2) |
| Domestic turkey | Meleagris gallopavo | 1/10 (10) | 5/10 (50) | P. juxtanucleare (1) P. gallinaceum (2) | |
| Maha Sarakham | Swan goose | Anser cygnoides | 0/11 (0) | 1/11 (9.1) | Plasmodium sp. (1) |
| Domestic duck | Anas platyrhynchos domesticus | 2/30 (6.7) | 7/30 (23.3) | Plasmodium sp. (7) | |
| Domestic turkey | Meleagris gallopavo | 7/26 (26.9) | 20/26 (76.9) | Plasmodium sp. (18) P. gallinaceum (2) | |
| Swan goose | Anser cygnoides | 0/9 (0) | 0/9 (0) | - | |
| Total | 11/116 (9.5) | 37/116 (31.9) | |||
Table 2.
Lineages of 37 cytochrome b gene sequences from backyard poultry in Thailand with matches to MalAvi database and National Center for Biotechnology Information (NCBI) GenBank database sequences
| Lineage names | Parasites | Sample IDs | NCBI GenBank accession No. | Closest sequences in NCBI GenBank (% similarity) |
|---|---|---|---|---|
| ACCBAD01 | Plasmodium sp. | D3, D5, D11, D34, D38, D42, D43, D51, D53, T4, T6, T13, T15, T26, T34, T17 | OR341180 | MK390829.1 (100%), JN639001.1 (100%) |
| ORW1 | Plasmodium sp. | D36, T11, T12, T14, T16, T18, T21, T22, T25, T27, T29, T31, T30, T32 | OR341179 | EF552403.1 (100%), KJ145050.1 (100%), KJ396632.1 (100%) |
| FANTAIL01 | Plasmodium sp. | G5 | OR341184 | AY714196.1 (100%), HF543648.1 (100%) |
| ANAPLA | Plasmodium sp. | D1 | OR341178 | MK390829.1 (99.78%), JN639001.1 (99.78%) |
| GALLUS01 | P. gallinaceum | T2, T7 | OR341181 | LC506179.1 (96.63-100%), LN835294.1 (96.63-100%) |
| MELGAL | P. gallinaceum | T20, T28 | OR341183 | LC506179.1 (99.77%), LN835294.1 (99.77%) |
| GALLUS02 | P. juxtanucleare | T9 | OR341182 | KU248845.1 (99.56%), KT290918.1 (99.56%) |
Fig. 3.
Phylogenetic tree based on partial cytochrome b gene sequences of Plasmodium in this study (indicated in bold typeface) together with 33 related sequences from different distributions in Thailand and neighbouring countries in the GenBank and MalAvi databases. Sequences were compared with the maximum likelihood method. The cytochrome b gene of two Haemoproteus sp. was used as the outgroup. The percentage of trees in which associated taxa clustered together is shown next to the branch
Table 3.
Association among Plasmodium spp. infections with PCV levels
| Host | Parasites | Levels of PCV (%) (mean ± SD) | 95% CI of average PCV value (%) | P-value | Normal range (24) | |
|---|---|---|---|---|---|---|
| Common name | Scientific name | Plasmodium spp. infections | ||||
| Duck | Anas platyrhynchos domesticus | infected (n = 11) | 34.91 ± 4.87 | 31.64-38.18 | 0.62 | 36-58% |
| uninfected (n = 49) | 33.83 ± 6.68 | 31.89-35.77 | ||||
| Turkey | Meleagris gallopavo | infected (n = 25) | 38.92 ± 5.50 | 36.59-41.24 | 0.07 | 36-41% |
| uninfected (n = 11) | 35.09 ± 5.82 | 31.18-39.00 | ||||
| Geese | Anser cygnoides | infected (n = 1) | 47.00 | N/A | N/A | 38-58% |
| uninfected (n = 19) | 41.10 ± 3.03 | 38.93-43.27 | ||||