Molecular Identification of Aedes, Armigeres, and Culex Mosquitoes (Diptera: Culicidae) Using Mitochondrial Cytochrome Oxidase Subunit I Genes in Myanmar.

PURPOSE: Mosquitoes are important vectors that carry disease-causing agents that can affect humans and animals. DNA barcoding is a complementary identification which can be used to validate morphological characterization of mosquito species. The objectives of this study were to identify the mitochondrial sequence of the COI gene and to construct a molecular phylogeny based on the genetic divergence of the mosquito species studied. METHODS: In this study, DNA extraction and the amplification of the mitochondrial cytochrome oxidase subunit I genes (COI) were performed on pooled mosquito samples collected in Nay Pyi Taw area, Myanmar. RESULTS: Fragments of the COI gene showed 99-100% identity with sequences of Aedes aegypti, Armigeres subalbatus, Culex pipiens complex, and Cx. quinquefasciatus, respectively, deposited in GenBank. This study categorized two haplotypes from each Ar. subalbatus and Cx. pipiens complex COI gene sequence, as well as three haplotypes from Cx. quinquefasciatus COI gene sequences. The highest haplotype diversity and nucleotide diversity were observed in the Ar. subalbatus population (Hd = 1.0000; π = 0.0033), followed by the Cx. pipiens complex and Cx. quinquefasciatus populations. CONCLUSION: This study provides useful information on the molecular identification and genetic diversity of mosquito vectors with medical and veterinary significance, which may assist in the improvement of mosquito control programs.

The first molecular confirmation of Culex pipiens complex as potential natural vectors of Dirofilaria immitis in Myanmar.

Dirofilariosis, known as one of the most widespread vector-borne zoonotic diseases, is caused by several different species of the nematodes of the genus Dirofilaria, which can be transmitted by Culex, Anopheles and Aedes mosquito vectors. In order to identify key vector mosquitoes of filarial parasites in Myanmar, mosquitoes were collected during three different seasons (summer, rainy and winter) in three townships in Nay Pyi Taw area, Myanmar. DNA extraction and polymerase chain reaction (PCR) analyses were conducted for 185 mosquito pools, with each pool containing 1-10 mosquitoes. Dirofilaria immitis was detected in 20 pools of Culex pipiens complex mosquitoes. The minimum infection rate of mosquitoes was found to be 16.33. The small subunit ribosomal RNA (12S rDNA) gene targeted PCR revealed that the sequences obtained were completely identical to the sequences of D. immitis derived from dogs in China, Brazil and France. The sequences obtained from mitochondrial cytochrome oxidase subunit I (COI) gene PCR exhibited 100% identity with the sequences of D. immitis derived from dogs in Bangladesh, Iran, Japan and Thailand, as well as humans in Iran and Thailand, and mosquitoes in Germany and Hungary. The findings of this study demonstrated that the mosquito species of Cx. pipiens complex are potential mosquito vectors for dirofilariosis in Myanmar.

Discerning risk and uncertainty with "better insurance" - How animal health interventions for village chickens influence farmers' perceptions on the prevention of poultry diseases.

High mortality in young chicks and deaths from Newcastle disease (ND) are the two major constraints to village chicken production in low-and middle-income countries. A 12-month intervention study was conducted across 174 households in two townships of Central Myanmar, to reduce these chicken mortalities. Interventions included ND vaccinations of village chickens and improved chick management. Following the Health Belief Model (HBM) framework, 81 village chicken farmers involved in the intervention study were repeatedly surveyed before and after the interventions to determine the level of change in farmers' knowledge about ND, perceptions about susceptibility and severity of ND virus infection, perceptions about benefits and barriers of ND vaccination, as well as farmers' actions to improve the health status of their birds and to improve biosecurity and ND control measures. Marginal homogeneity tests were used to compare the level of change in farmers' matched responses to individual survey questions before and after the interventions. In addition, confirmatory factor analysis and structural equation modelling was used to create latent variables describing farmers' perceptions about susceptibility and severity of ND in their birds, farmers' perceptions about the barriers and benefits of conducting ND vaccination as well as farmers' cues to action and self-efficacy before and after the interventions. Interventions resulted in 33% more chicks surviving, which resulted in increased sales of birds after they had reached a market age of 7 months. After the interventions, farmers acknowledged the value of protecting birds from ND to increase their income (p = 0.0002). Farmers were also more willing to overcome barriers to vaccination (i.e., 'catching' birds for ND vaccinations) after the interventions (p = 0.0388). Interestingly, after the interventions, fewer farmers were concerned about the risk of their birds becoming infected with ND virus through cock fights and non-confinement (p = 0.0008 and p = 0.00022, respectively), and farmers were more uncertain about the susceptibility of their birds to ND virus infection after the interventions. Surprisingly, farmers became 'less active' in ensuring good biosecurity practices after the interventions: fewer farmers were willing to observe disease signs in village chickens (p < 0.001) and fewer farmers buried dead birds (p < 0.001). Perceived susceptibility was the only HBM component that was significantly reduced (p = 0.014) after the interventions: thus, less farmers were concerned about ND even when using management practices associated with high risk of ND transmission (e.g., cook fights, no confinement). Our results highlight the importance of information campaigns and extension work to ensure farmers maintain a high level of biosecurity when animal health interventions are implemented.

The first seroepidemiological study on Toxoplasma gondii in backyard pigs in Myanmar.

A cross-sectional study of Toxoplasma gondii infection in pigs was carried out in backyard farms in three townships, within Nay Pyi Taw area from June 2014 to August 2014. Blood samples were randomly collected from 256 pigs in 129 farms. Using commercial Latex Agglutination Test kits, specific antibodies to T. gondii were analyzed. Based on LAT results, among 256 serum samples examined, 47 samples (18.4%) were found positive to T. gondii. The numbers of samples showing specific antibody titres from 47 positive pig sera were 20 at 1:64, 2 samples at 1:128, 9 samples at 1:256, 3 samples at 1:512 and 13 samples at 1:1024. Among the hypothesized risk factors, roaming of cats around the farm was found associated to T. gondii seropositivity in pigs (OR = 3.13; 95% CI = 1.33-7.34). This study provides information on seroepidemiology study of T. gondii in backyard pigs for the first time in Myanmar. This information will be useful in developing strategies for the control of T. gondii infection in pigs.

Antimicrobials use and resistance on integrated poultry-fish farming systems in the Ayeyarwady Delta of Myanmar.

Antimicrobials are used to support livestock health and productivity, but might pose a risk for the development of antimicrobial resistance; in particular, when multiple livestock species are raised together in production systems. On integrated chicken-fish farms, chickens are raised over fish ponds and poultry faeces is excreted into the ponds. We investigated antimicrobial usage and the antimicrobial susceptibility of Escherichia coli cultured from poultry faeces on 301 integrated farms in Ayeyarwady Delta of Myanmar. Antimicrobials were used by 92.4% of farmers for chickens, but they were not applied to fish. The most common antimicrobials used were Octamix (amoxicillin and colistin sulfate) on 28.4%, enrofloxacin on 21.0% and amoxicillin on 16% of farms. Overall, 83.1% (152/183) of the E. coli were resistant to at least one antimicrobial. The highest level of resistance was to amoxicillin (54.6%), tetracycline (39.9%), sulfamethoxazole/trimethoprim (35.5%) and enrofloxacin (34.4%). Multidrug resistance was identified in 42.4% of isolates. In general, we found similar levels of antimicrobial resistance in non-users of antimicrobials as in users of antimicrobials for more commonly applied antimicrobials. Overall, antimicrobial resistance was lower in chickens on these integrated farms in Myanmar, compared to poultry farms in other countries of South East and East Asia.

Bacterial content and associated risk factors influencing the quality of bulk tank milk collected from dairy cattle farms in Mandalay Region.

To investigate the bacterial content and risk factors associated with the hygienic quality of raw milk, a cross-sectional study was conducted in four townships of Mandalay Region, Myanmar. From April to October 2017, bulk tank milk samples (n = 233) were collected from 233 dairy cattle farms located in Tada-U, Pyin Oo Lwin, Meiktila, and Patheingyi Townships. From each farm, approximately 100 ml of bulk tank milk was collected and examined for bacterial content. Total bacterial count (TBC) and coliform count (CC) in milk samples were determined using milk agar and violet red bile agar. Of 233 milk samples, 68.2% (159/233) showed TBC higher than 1.0 × 105 cfu/ml, and 78.4% (183/233) showed CC higher than 100 cfu/ml. The mean value of TBC among 233 farms was 2.55 × 107 cfu/ml, ranging from 6.0 × 103 to 3.0 × 109 cfu/ml, whereas the mean value of CC was 1.59 × 105 cfu/ml, ranging from 10 to 8.4 × 106 cfu/ml. TBC tended to increase as CC increased in milk samples. The number of precautionary measures for milking operation, choice of cleaning materials, training experience of the farmers, cleanliness score of milking cows, and CMT scores of milk were significantly associated (p < 0.05) with TBC in bulk tank milk. Similarly, the number of precautionary measures for milking operation, choice of cleaning materials, training experience of the farmers, cleanliness scores of milking cows, CMT scores of milk samples, herd size, and type of milking practice showed significant association (p < 0.05) with CC in bulk tank milk. The effects of these potential risk factors should be minimized, farmers should be trained properly, and technical support should be provided, so that the quality of raw milk produced in Myanmar can be improved.

Serological Survey and Factors Associated with Toxoplasma gondii Infection in Domestic Goats in Myanmar.

Goat farming is important for the livelihood of millions of rural people because it contributes to food security and creation of assets. However, infection of goats with Toxoplasma gondii could be a source of parasite transmission to humans. The information on T. gondii infection of goat was not reported yet in Myanmar. A total of 119 goat serum samples were collected from three cities in the central region of Myanmar for T. gondii antibody survey. With the occurrence value obtained in this first study, a second one, more complete, with larger number (162) of animals and properties, was carried out and the risk factors and prevalence were determined. In both studies the samples were analyzed by the LAT. Of these, 32 (11.4%) samples were showed to be positive. The infection was associated with the presence of cats at the farm (odds ratio [OR] = 4.66, 95% confidential interval [CI] = 1.03-21.06), farming with different animal species (sheep, cattle, and pigs) (OR = 4.33, 95% CI = 1.57-11.94), and farming without good management practices (OR = 0.23, 95% CI = 0.06-0.83). This is the first T. gondii prevalence study in goats in the country.

Epidemiological Survey on Porcine Cysticercosis in Nay Pyi Taw Area, Myanmar.

Cross-sectional surveys were conducted to determine the prevalence and associated risk factors of Taenia solium cysticercosis in pigs within Nay Pyi Taw area, Myanmar. Meat inspection in three slaughterhouses, ELISA test, and questionnaire surveys were conducted in this study. Three hundred pigs were inspected in slaughterhouses and 364 pigs were randomly selected and examined from 203 households from three townships in Nay Pyi Taw area. The prevalence of porcine cysticercosis in meat inspection was 23.67% (71/300). Seroprevalence of T. solium cysticercosis in pigs in the study area was 15.93% (58/364). Significant associated risk factors with T. solium cysticercosis were gender (OR = 3.0; 95% CI = 1.7-5.4), increased age (OR = 2.3; 95% CI = 1.2-4.2), husbandry system (OR = 5.1; 95% CI = 2.4-11.2), feed type (OR = 16.9; 95% CI = 2.3-124.3), not using anthelmintics in pigs (OR = 11.9; 95% CI = 5.0-28.5), not using anthelmintics in owner (OR = 2.5; 95% CI = 1.4-4.4), no hand-washing before feeding (OR = 31.5; 95% CI = 4.3-230.9), and pork consumption of owner (OR = 37.4; 95% CI = 9.0-156.1) in the study area. This is the first report of porcine cysticercosis in Myanmar.

Prevalence of multidrug resistance Campylobacter jejuni and Campylobacter coli in chickens slaughtered in selected markets, Malaysia.

The objectives of this study were to determine the occurrence of Campylobacter spp. in live chickens sold at wet markets in Selangor, Malaysia and the multidrug resistance (MDR) profiles of the isolates. Cloacal swabs were taken from the chickens before slaughter and their caecal mucosae were swabbed after slaughter. Of the 90 chickens examined, 68 (75.6%) were positive for Campylobacter. Campylobacter were recovered from caecal swabs (53/90) and cloacal swabs (34/90) and Campylobacter coli (46 isolates) were identified slightly more than Campylobacter jejuni (41 isolates), but these differences were not significant (p<0.05). The most frequently observed resistance was to cephalothin (95.5%), followed by tetracycline (80.8%), erythromycin (51.4%), enrofloxacin (42.4%) and gentamicin (24.4%). Multidrug resistance (resistant to four or more antibiotics) was detected in 35.3% isolates. Campylobacter jejuni showed nine resistance profiles and the most common was to gentamicin-eryhtromycin-enrofloxacin-cephalothin-tetracycline (32.4%) combination while C. coli showed six profiles, with cephalothin-tetracycline (32.2%) combination being most common.