Leptospirosis is a serious bacterial disease that affects both humans and animals. A wide range of symptoms have been described in humans; the disease in dogs is commonly associated with kidney and/or liver disease. In Malaysia, information about the common serovars infecting dogs is limited. Therefore, we investigated the occurrences of leptospirosis in 124 pet dogs diagnosed with kidney and/or liver disease. Blood, urine, abdominal effusion, and/or kidney and liver were collected from the dogs. Based on microscopic agglutination testing, 53 of 124 (42.7%) dogs were seropositive for leptospiral exposure. Sera were frequently positive to serovars Bataviae (n = 12), Javanica (n = 10), and Icterohaemorrhagiae (n = 10). Direct detection using PCR showed that 42 of 124 (33.9%) of the whole blood and 36 of 113 (31.9%) urine samples were positive for pathogenic Leptospira spp. By PCR, 2 of 23 (9.1%) kidney and 2 of 23 (9.1%) liver were positive for pathogenic Leptospira spp. Abdominal effusion from 4 dogs were PCR-positive for pathogenic Leptospira spp. The species detected were L. interrogans, L. borgpetersenii, L. kirschneri, and L. kmetyi by partial 16S rRNA sequencing. We further identified and characterized 11 Leptospira spp. isolates from 8 dogs as serovars Bataviae, Javanica, and Australis. The mortality rate of the Leptospira-infected dogs was high (18 of 53; 34%).
Toxoplasmosis is a worldwide zoonosis caused by the protozoa Toxoplasma gondii which affects human and animals. Village chickens (Gallus domesticus) most commonly known as Ayam Kampung or free-range chickens, have been suggested to play a role in the epidemiology of toxoplasmosis. This study determines the presence of T. gondii in the village chicken populations in two states of Malaysia. A total of 50 serum samples from the chickens from Selangor (n=20) and Melaka (n=30) were collected and analysed using commercial serological kits. T. gondii antigen was detected in 20% (Selangor 30%; Melaka 13%) samples using ELISA test and anti-T. gondii antibody was detected in all positive ELISA samples using the indirect haemagglutination test (IHAT). Histopathological examination revealed tissue changes such as inflammation and degeneration in brain and liver of seropositive chickens. This is the first report of T. gondii infection in the village chickens in Malaysia.
Bovine anaplasmosis is a tick-borne disease in cattle which is mainly caused by Anaplasma marginale and Anaplasma centrale. It poses significant economic burdens and threat on livestock industries worldwide. This study aimed to identify Anaplasma spp. infecting the commercial Mafriwal cattle in Johor, Malaysia and investigate their phylogenetic relationship in the population. In this study, polymerase chain reaction (PCR) targeting the MSP4 gene for A. marginale and the 16s rRNA gene for A. centrale were performed. These assays were conducted on blood samples collected from 242 Mafriwal cattle. BLAST analysis and phylogenetic trees were constructed to analyze the genetic relationships between the Anaplasma spp. The results revealed 57.85% of the sampled population were infected with Anaplasma spp., 21.90% with A. marginale, 9.50% with A. centrale and 26.45% with both A. marginale and A. centrale. BLAST analysis showed 100% similarities between A. marginale sequences from this study and the sequence from a goat in Brazil. Similarly, A. centrale sequences were closely related to strains from tick vector, Rhipicephalus (Boophilus) microplus in Panama with 100% similarity. Phylogenetic analysis confirmed distinct clades for A. marginale and A. centrale, indicating genetic diversity and specific species differentiation. The findings highlight the endemicity of bovine anaplasmosis in Malaysian cattle populations and potential cross-border transmission routes. Moreover, this study provides the first report of A. centrale prevalence in Malaysia, emphasizing the importance of ongoing surveillance and management efforts. Understanding the genetic diversity and species differentiation of these pathogens is crucial for designing effective control strategies and vaccine development. In conclusion, this study enhances our understanding of the prevalence and genetic dynamics of bovine anaplasmosis among Mafriwal cattle in its largest population in Malaysia for better diagnosis and effective control measures.
The incidence of leptospirosis seems to be on the rise and could be an alarming indirect indication of a global re-emergence. It is a potential public health threat when dogs are speculated to be involved in the transmission of leptospirosis through possible subclinical harbouring of Leptospira spp. and subsequent shedding into the environment. This study aimed to detect anti-leptospiral antibodies among dogs and their handlers using the microscopic agglutination test (MAT). Blood samples from 266 apparently healthy dogs and 194 dog handlers were collected at four working dog organisations and four dog shelters. Serum samples were tested using MAT against 20 leptospiral serovars with a cut-off titre >=1:100 (dog) and >=1:50 (dog handlers). Seventy dogs (70/266; 26.3%) were seropositive mainly against serovars Icterohaemorrhagiae, Ballum, Bataviae and Javanica (titres ranged: 1:100-1:800). Sixty-seven dog handlers (67/194; 34.5%) were seropositive mainly against serovars Grippotyphosa, Icterohaemorrhagiae and Malaysia (titres ranged: 1:50-1:200). Dogs were seropositive due to exposure, vaccination or active infection. Seropositive dog handlers could indicate exposure or active infection. This shows the potential of dogs in maintaining and spreading the infection in Malaysia. Due to the occupational risk as a result of frequent contact with dogs and exposure to contaminated environments, dog handlers should be made aware of the presence of this zoonotic disease.
The post-transcriptional modification of tRNAs plays a crucial role in tRNA structure and function. Pathogenic variants in tRNA-modification enzymes have been implicated in a wide range of human neurodevelopmental and neurological disorders. However, the molecular basis for many of these disorders remains unknown. Here, we describe a comprehensive cohort of 43 individuals from 31 unrelated families with bi-allelic variants in tRNA methyltransferase 1 (TRMT1). These individuals present with a neurodevelopmental disorder universally characterized by developmental delay and intellectual disability, accompanied by variable behavioral abnormalities, epilepsy, and facial dysmorphism. The identified variants include ultra-rare TRMT1 variants, comprising missense and predicted loss-of-function variants, which segregate with the observed clinical pathology. Our findings reveal that several variants lead to mis-splicing and a consequent loss of TRMT1 protein accumulation. Moreover, cells derived from individuals harboring TRMT1 variants exhibit a deficiency in tRNA modifications catalyzed by TRMT1. Molecular analysis reveals distinct regions of TRMT1 required for tRNA-modification activity and binding. Notably, depletion of Trmt1 protein in zebrafish is sufficient to induce developmental and behavioral phenotypes along with gene-expression changes associated with disrupted cell cycle, immune response, and neurodegenerative disorders. Altogether, these findings demonstrate that loss of TRMT1-catalyzed tRNA modifications leads to intellectual disability and provides insight into the molecular underpinnings of tRNA-modification deficiency caused by pathogenic TRMT1 variants.