Interaction between abomasal blood feeder Haemonchus contortus and intestinal mucosal browser Trichostrongylus colubriformis during co-infection in Boer goats

This study was conducted to investigate potential interactions between the abomasal blood feeder Haemonchus contortus and the intestinal mucosal browser Trichostrongylus colubriformis among deliberately infected Boer goats. Faecal and blood samples were collected twice a week for eight weeks from 25 parasite-naïve goats. Correlation analysis and multiple linear regression models were conducted to explore the association between phenotypic variables and variables taken at necropsy. Positive associations were identified between total FEC and log T. colubriformis number (r = 0.62, p < 0.05) as well as between IgA and peripheral eosinophil counts (r = 0.65, p < 0.05). A negative correlation was observed between T. colubriformis and log H. contortus number (r=-0.56, p < 0.05). Multiple linear regression models show that H. contortus and T. colubriformis interacted with each other. T. colubriformis appeared to contribute more significantly to the variation of FEC than H. contortus. Co-infection induced an IgA response which was only effective against T. colubriformis but not protective against H. contortus infection. This could be seen via significant associations of IgA with both nematode species but with the effect of IgA differing for H. contortus and T. colubriformis. In this study, H. contortus infection was not detrimental to the goats with no observed impact on PCV. This could be because the growth of T. colubriformis as represented by its length was associated with reduced number and composite burden of H. contortus during co-infection, or possibly due to low infection dosage. Improved understanding of the impact of H. contortus and T. colubriformis and their interaction from natural co-infection studies is beneficial for a better understanding of the goat-parasite interaction and its potential impacts on the health and productivity of animals

Molecular detection and epidemiological risk factors associated with Cryptosporidium infection among cattle in Peninsular Malaysia

Enteric protozoa infection among cattle may pose a threat to productivity and survival leading to negative impacts on the livestock industry. A number of these pathogens are also known to be zoonotic and are of public health concern. Despite the importance of these enteric protozoa to both animal and human health, there remains a paucity of published information on the epidemiological risk factors that may be associated with bovine cryptosporidiosis in Southeast Asia. The present study was undertaken to determine the molecular prevalence and associated risk factors for Cryptosporidium infection among beef and dairy cattle in Peninsular Malaysia. Faecal samples were collected from 824 cattle in 39 farms (526 beef and 298 dairy) situated in 33 locations throughout the country, and subjected to PCR detection for Cryptosporidium using primers targeting the 18S SSUrRNA gene. Epidemiological variables including host, environment and management factors were subjected to univariate and multivariate logistic regression analyses to determine the potential risk factors for infection. The prevalence of Cryptosporidium among the cattle was 12.5%, with significant difference in the infection rate among the various breeds. There was no significant effect of gender, and both the beef and dairy cattle were at similar odds for infection. The younger cattle had a significantly higher infection rate compared to the older animals. Multivariate analysis revealed that deworming practice, distance to human settlement, geographical location (zone) and farm management system were significant risk factors associated with Cryptosporidium infection. The cattle that were reared on farms located in the northeast of the country, closest (≤200 m) to human settlements, reared extensively, and dewormed every four months were at highest risk of infection. The present study constitutes the first attempt to analyze the multivariable epidemiological risk factors involved in bovine cryptosporidiosis in Malaysia and in Southeast Asia. It is envisaged that the data obtained will facilitate better control and prevention measures for Cryptosporidium infection among cattle in the region. Due to the potential zoonotic nature of the infection, serious steps should be instituted for animal treatment and biohazard waste management on local cattle farms

Molecular epidemiology of enteric protozoa and genotyping of Blastocystis from porcine on the west coast of Peninsular Malaysia

Enteric protozoa of animals are of a major public health concern as a number are known to be zoonotic with high rates of transmission via contaminated food and water. Pigs are known to be the reservoirs for many zoonotic pathogens worldwide that exert negative impacts to human health and the agricultural economy of many countries. The present study aims at determining the molecular prevalence and risk factors associated with enteric protozoa infection in pigs reared on farms located along the west coast of Peninsular Malaysia, and to genetically characterized and determine the diversity of Blastocystis subtypes that are infecting these pigs in the country. Fecal samples were collected from 450 pigs from 15 different farms along the west coast of Peninsular Malaysia, and subjected to nested PCR amplification using genus specific primers. Molecular detection revealed that pigs in the country harbored a relatively high prevalence of Balantidium (70.4%), Blastocystis (55.6%), Enterocytozoon (40.7%), Giardia (22.0%) and Cryptosporidium (19.3%). A total of 94.2% of the pigs examined were infected with one or more of these enteric protozoa. The highest protozoa co-infection was triple co-infection (37.0%), followed by quadruple coinfection (29.0%). Multiple logistic regression showed that the age of the farm and distance of farm from human settlement were significant risk factors associated with Giardia infection. The age of the farm and number of swine on the farms were significantly associated with Blastocystis infection. The multivariate model also showed that the age of pigs and the distance of the farms from human settlement were significant risk factors for Balantidium and Enterocytozoon infection. In addition, the farm production type also played a significant role in the prevalence of the latter. None of the epidemiological factors examined were significantly associated with Cryptosporidium infection. Positive amplicons of Blastocystis were cloned and sequenced to determine the genetic variability of the local Blastocystis isolates. Bioinformatics and phylogenetic analysis revealed the presence of four subtypes (ST1, ST3, ST5 and ST10) among the infected swine, of which ST1, ST3 and ST5 are known to be able to infect humans. The highest prevalence was with ST5 (66.7%), followed by ST10 (24.4%), ST3 (15.6%) and lastly ST1 (8.9%). Analysis of haplotype diversity and prevalence revealed that H029 and H061 of the ST5 group were the most common haplotypes in the pigs. The present study constitutes the first attempt to determine the molecular epidemiology of porcine enteric protozoa in the country, and the genetic composition of Blastocystis among swine in Malaysia. It is envisaged that the data obtained from this study will afford a clearer understanding on the epidemiology and genetics of zoonotic enteric protozoa infecting swine in the country, which in turn may facilitate country-wide efforts in the control and prevention of these zoonotic pathogens

Molecular detection of porcine Enterocytozoon bieneusi infection in Peninsular Malaysia and epidemiological risk factors associated with potentially zoonotic genotypes

Enterocytozoon bieneusi is an emerging opportunistic pathogen infecting humans, and both domestic and wild pigs are known to harbour zoonotic genotypes. There remains a paucity of information on the prevalence and epidemiology of this enteropathogen in Southeast Asia. The present study was undertaken to determine the molecular prevalence and risk factors associated with E. bieneusi infection among commercially farmed pigs in Malaysia. Faecal samples were collected from 450 pigs from 15 different farms and subjected to nested PCR amplification of the ribosomal internal transcribed spacer (ITS) gene of E. bieneusi. Phylogenetic analysis involved 28 nucleotide sequences of the ITS region of E. bieneusi. An interviewer-administered questionnaire provided information on the animal hosts, farm management systems and environmental factors and was statistically analysed to determine the risk factors for infection. The prevalence of E. bieneusi infection was relatively high (40.7%). The highest prevalence (51.3%) was recorded among the piglets, while the adults showed the lowest level of infection (31.3%). Multivariate analysis indicated that age of the pigs, distance of the farm from human settlement and farm management system were significant risk factors of infection. Three genotypes (EbpA, EbpC and Henan-III) detected among the pigs are potentially zoonotic. The high prevalence of E. bieneusi among locally reared pigs, the presence of zoonotic genotypes and the spatial distribution of pig farms and human settlements warrant further investigation on the possibility of zoonotic transmission

Endoscopy gender determination and reproductive hormone profiles of Painted Terrapins (<i>Batagur borneoensis</i>) subjected to <i>ex situ</i> incubation

Chelonian exhibit temperature dependent sex determination, and ex situ incubation of eggs in conservation hatcheries may render a gender bias. The gender of juvenile Painted terrapins (Batagur borneoensis) produced at a conservation hatchery in Malaysia was determined by endoscopy of the gonads. Circulating reproductive hormones (testosterone, progesterone and estradiol) were profiled for 31 juveniles and nine captive-reared non-breeding adult terrapins. Endoscopy revealed a gender bias of 96.8% (30/31) females. Testosterone levels in the juvenile females (2.49 ± 1.29) were significantly lower than that of the adult females (12.20 ± 4.29), and lower than values in the juvenile male (9.36) and adult males (27.60, 35.62). The progesterone levels in the juvenile females (107.12 ± 68.68) were significantly higher than that of the adult females (51.13 ± 24.67), but lower than values in the juvenile male (33.27) and adult males (3.43, 8.51). Estrogen levels were significantly lower in the juvenile females (1.57 ± 1.35) compared to the adult females (77.46 ± 53.45). Negative correlations were observed between levels of progesterone and testosterone, and progesterone and estrogen. A positive correlation was noted between estrogen and testosterone. The present study constitutes the first attempt to determine the gender and reproductive hormone profiles of juvenile Painted terrapins produced by ex situ incubation, and captive non-breeding adults. Endoscopy of the gonads is a useful techniques for gender determination among juvenile turtles, while the use of testosterone as a gender biomarker warrants further investigation