RESUMO
BACKGROUND AND AIM: Melioidosis is a potentially fatal disease affecting humans and a wide range of animal species; it is often underdiagnosed and underreported in veterinary medicine in Indonesia. This study aimed to characterize morphological and molecular features of Burkholderia pseudomallei, the causative agent of melioidosis which caused the death of a Bornean orangutan. MATERIALS AND METHODS: Pulmonary abscess samples were cultured on several types of media, including Ashdown agar, Ashdown broth, and MacConkey agar. Type three secretion system orf 2 real-time polymerase chain reaction (PCR) and latex agglutination tests were performed to identify the bacteria. Morphological characteristics were compared to all previously published morphotypes. Subsequently, the bacteria were characterized by multilocus sequence typing (MLST) and Yersinia-like flagellum/Burkholderia thailandensis-like flagellum and chemotaxis PCR. The results of the genotyping were afterward compared to all genotypes from Southeast Asia. RESULTS: Multiple morphotypes of B. pseudomallei were perceived during the growth on Ashdown agar. Furthermore, it was identified by MLST that the Type I and Type II morphotypes observed in this study were clones of a single ST, ST54, which is predominantly found in humans and the environment in Malaysia and Thailand, although a very limited number of reports was published in association with animals. Moreover, the E-BURST analysis showed that the ST is grouped together with isolates from Southeast Asian countries, including Malaysia, Thailand, Singapore, and Cambodia. ST54 was predicted to be the founding genotype of several STs from those regions. CONCLUSION: B. pseudomallei ST54 that caused the death of a Bornean orangutan has a distant genetic relationship with other STs which were previously reported in Indonesia, implying a vast genetic diversity in Indonesia that has not been discovered yet.
RESUMO
Burkholderia pseudomallei, the Gram-negative bacterium which causes melioidosis, is a threat to human and a wide range of animal species. There is an increased concern of melioidosis in Indonesian primate facilities, especially following case reports of fatal melioidosis in captive macaques and orangutans. Our preliminary serosurveillance of immunoglobulin G (IgG) to B. pseudomallei lipopolysaccharide showed that a significant number of captive and wild macaques in the western part of Java, Indonesia, have been exposed to B. pseudomallei. To better characterize the humoral immune response in those animals, a panel of assays were conducted on the same blood plasma specimens that were taken from 182 cynomolgus macaques (M. fascicularis) and 88 pig-tailed macaques (M. nemestrina) reared in captive enclosures and wild habitats in the western part of Java, Indonesia. The enzyme-linked immunosorbent assays (ELISAs) in this study were conducted to detect IgG against B. pseudomallei proteins; alkyl hydroperoxide reductase subunit C (AhpC), hemolysin-coregulated protein (Hcp1), and putative outer membrane porin protein (OmpH). The performances of those immunoassays were compared to ELISA against B. pseudomallei LPS, which has been conducted previously. Seropositivity to at least one assay was 76.4% (139/182) and 13.6% (12/88) in cynomolgus macaques and pig-tailed macaques, respectively. Analysis of demographic factors showed that species and primate facility were significant factors. Cynomolgus macaques had higher probability of exposure to B. pseudomallei. Moreover, macaques in Jonggol facility also had higher probability, compared to macaques in other facilities. There were no statistical associations between seropositivity with other demographic factors such as sex, age group, and habitat type. There were strong positive correlations between the absorbance results of AhpC, HcpI, and OmpH assays, but not with LPS assay. Our analysis suggested that Hcp1 assay would complement LPS assay in melioidosis serosurveillance in macaques.
