Climatic factors and prevalence of Campylobacter in commercial broiler flocks in Thailand.

Campylobacter are bacteria associated with human foodborne disease worldwide. Poultry and poultry products are generally considered as a main source of these organisms. Compared to temperate zones, baseline information on Campylobacter in tropical regions is limited. Thus, the objectives of the present study were 1) to determine the prevalence of Campylobacter in Thai broiler flocks and 2) to investigate the association between climatic factors (i.e., rainfall, ambient temperature, and relative humidity) and Campylobacter colonization status of broiler flocks in Thailand. A total of 442 commercial broiler flocks reared in the central and northeastern regions of Thailand during 2012 to 2014 were investigated. Campylobacter positive status was identified in 252 examined flocks (57.01%; 95% CI 52.39 to 61.63%). Prevalence of Campylobacter in the northeastern region (54.46%; 95% CI 44.76 to 63.83%) was slightly lower than that of the central region (57.77%; 95% CI 52.47 to 62.90%). More than 65% of Campylobacter positive flocks in the central and northeastern regions had within-flock prevalence higher than 75%. Generalized estimating equations (GEE) revealed that the increased rainfall and relative humidity were associated with the increase of Campylobacter colonization in broiler flocks (P ≤ 0.05), while no relationship between ambient temperature and Campylobacter colonization status was identified.

PCR amplification of crude blood on microscope slides in the diagnosis of Trypanosoma evansi infection in dairy cattle.

In this study, we compared four T. evansi detection tests (Direct examination, Card Agglutination mouse inoculation and Polymerase Chain Reaction (PCR) in a natural infection of dairy cattle in central Thailand. The samples for PCR amplification were collected either in microfuge tubes or on microscope slides and the amplification results were compared. Collecting the samples on slides was faster and more convenient than collection in tubes. Comparable results were obtained from PCR amplification of both tube- and slide collected samples, processed twelve to fourteen days after collection. PCR was the most sensitive of the methods under comparison, using the mouse inoculation test as golden standard. The specificity of the PCR test under study is further discussed in this paper.

A simplified and highly sensitive detection of Trypanosoma evansi by DNA amplification.

In Southeast Asia Trypanosoma evansi infection is a disease of economic importance since it affects the health of buffalo, cattle and swine. The acute stage symptoms include abortion, central nervous system disorder and even death, and in the chronic condition working capacity and productivity of the animals are affected. A polymerase chain reaction (PCR)-based detection technique has been developed with a sensitivity of 0.5 pg of parasite DNA or one single parasite in 10 microliters of blood samples which were allowed to clot and then boiled before DNA amplification. This permitted storage of blood collection at ambient temperature for at least one month. Phosphate-saline-glucose solution, normally used as trypanosome maintenance buffer, inhibited PCR. Although DNA primers used were derived from T. evansi specific sequence, amplification of the genome of T. brucei and T. equiperdum generated the same 227 bp fragment. This method should now make it possible to detect infections in livestock in the very early stages where microscope examination is equivocal and to monitor groups of animals after trypanocidal treatment.