Colistin Resistance and ESBL Production in Salmonella and Escherichia coli from Pigs and Pork in the Thailand, Cambodia, Lao PDR, and Myanmar Border Area.

The study aimed to examine the prevalence and genetic characteristics of ESBL-production and colistin resistance in Salmonella and Escherichia coli from pigs and pork in the border area among Thailand, Cambodia, Lao PDR, and Myanmar. Salmonella (n = 463) and E. coli (n = 767) isolates were collected from pig rectal swab from slaughterhouses (n = 441) and pork from retail markets (n = 368) during October 2017 and March 2018. All were determined for susceptibility to colistin and cephalosporins, ESBL production and mcr and ESBL genes. Salmonella was predominantly found in Cambodia (65.8%). Serovars Rissen (35.6%) and Anatum (15.3%) were the most common. The E. coli prevalence in pork was above 91% in all countries. Colistin-resistance rate in E. coli (10.4%) was significantly higher than Salmonella (2.6%). ESBL-producing Salmonella (1.9%) and E. coli (6.3%) were detected. The blaCTX-M-55 and blaCTX-M-14 were identified. The mcr-1 gene was detected in Salmonella (n = 12) and E. coli (n = 68). The mcr-1/blaCTX-M-55 and mcr-3/blaCTX-M-55 co-concurrence was observed in one Salmonella and three E. coli isolates, respectively. In conclusion, pigs and pork serve as carriers of colistin and new generation cephalosporins resistance. Testing for resistance to last line antibiotics should be included in national AMR surveillance program using One Health approach.

Avian influenza epidemiology in semi-intensive free ranging duck flocks of the Moyingyi Wetland in Bago East District, Myanmar.

Highly pathogenic avian influenza virus subtype H5N1 first entered Myanmar in 2006 in the Mandalay District. Several H5N1 outbreaks followed and the one of Bago East District (2007) required post outbreak surveillance in the at-risk domestic duck population of the Moyingyi Wetland. A field epidemiological study based on a randomised prospective stratified study with five surveys provided the serological evidence that the avian influenza H5 subtype circulates in the domestic duck population and spreads to almost all the newly housed (and negative) flocks in the time span of a seasonal production cycle. Virological investigation was negative. The survival analysis showed that the probability of seroconversion increased rapidly over the study period, without significant difference among different agro-ecosystems. The analysis suggests that viral spread in the new cycle could be limited if control measures were adopted at the time new flocks are housed. The study recommends that future surveillance schemes for ducks are designed in a way to get as much information as possible from serological results which should drive virological sampling to determined farms.

Morphological and molecular characterization of Explanatum explanatum from cattle and buffaloes in Myanmar.

A robust molecular marker is needed for discrimination of amphistome species, because identification based on morphology alone requires specialized knowledge and techniques. In this study, we performed morphological and molecular characterization of Explanatum explanatum, a species that causes severe liver damage in definitive host species. Fifty-five adult amphistomes were collected from cattle and water buffaloes in Myanmar. Eighteen of the amphistomes, arbitrarily chosen, were morphologically identified as E. explanatum using sagittal sections. All of the 55 amphistome isolates had identical second internal transcribed spacer (ITS2) of ribosomal DNA sequences; these sequences differed at 7 nucleotide sites from those of the closest species, Paramphistomum leydeni. Our data indicate that the ITS2 sequence could be a useful molecular marker for epidemiological studies on E. explanatum.

Highly pathogenic avian influenza (H5N1) in Myanmar, 2006-2010.

Highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first reported in Myanmar in 2006. In this study, we have characterized 6 HPAI (H5N1) viruses recovered from 2007-2010 as well as three additional available nucleotide sequences representing Myanmar AI outbreaks. Phylogenetic analysis showed that the Myanmar viruses belong to HPAI (H5N1) clades 7, 2.3.2 and 2.3.4. The result suggested that the HPAI (H5N1) viruses recovered from Myanmar had been introduced into the country by multiple introductions. Genetic analysis of the viruses confirmed the HPAI characteristics of the viruses.

Characterization of Fasciola spp. in Myanmar on the basis of spermatogenesis status and nuclear and mitochondrial DNA markers.

Fasciola spp. in Myanmar were characterized on the basis of spermatogenesis status and DNA markers of nuclear internal transcribed spacer 1 (ITS1) and mitochondrial NADH dehydrogenase subunit 1 (nad1). We collected 88 adult flukes from Yangon, Lashio, and Myitkyina. Spermatogenesis status was analyzed by the presence of sperm in the seminal vesicles, and 8 aspermic and 80 spermic flukes were detected. The flukes were identified on the basis of spermatogenesis status and ITS1 types which were analyzed by a PCR-RFLP method, and 80 spermic flukes were identified as F. gigantica. A very low detection rate of aspermic Fasciola sp. indicated that they are not established in Myanmar. In phylogenetic analyses, the 7 aspermic Fasciola sp. from Myitkyina displayed a haplotype in nad1 sequence, which was identical to that of aspermic Fasciola sp. from other Asian countries including China. Therefore, they were probably introduced from China through an infected domestic ruminant. On the other hand, 17 nad1 haplotypes detected in F. gigantica belonged to 2 clades unique to Myanmar, each with a distinct founder haplotype in a network analysis. This indicated a unique history of F. gigantica introduction into Myanmar involving ancient artificial movements of domestic ruminants.