Prevalence and genotyping of Cryptosporidium SPP from dairy cow fecal samples in western Thailand

The aims of this study were to determine the prevalence of Cryptosporidium spp in dairy cows in central Thailand and to investigate the genotype of Cryptosporidium spp in this population. A total of 200 fecal samples from dairy cows were collected and examined by the acid-fast staining technique and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The prevalence of Cryptosporidium infection in dairy cows was 7% (95% CI 3.5-10.5) by acid-fast staining, and 15.5% (95% CI 10.5-20.5) by PCR-RFLP. This is the first report of genetic identification of the C. parvum bovine genotype in dairy cows in Thailand. PCR-RFLP analysis showed all positive samples were C. parvum (bovine genotype). C. andersoni was not found in this study. The only significant risk factor for Cryptosporidium infection in dairy cows was age. Calves less than 2 months old were more frequently infected by Cryptosporidium than others (OR 13.82, 95% CI 3.67-51.97, p = 0.001). Cattle may be a potential source of human cryptosporidiosis.     

Shiga toxin- and enterotoxin-producing Escherichia coli isolated from subjects with bloody and nonbloody diarrhea in Bangkok,Thailand

A total of 314 stool samples collected from 92 subjects with bloody diarrhea, 119 subjects with non-bloody diarrhea and 103 normal subjects in Bangkok, Thailand, were investigated for the presence of Shiga toxin-producing Escherichia coli (STEC) and enterotoxin-producing E. coli (ETEC) by multiplex PCR assay. Virulence genes and cytotoxic effect to Vero cells of STEC were also determined. STEC (5 isolates) and ETEC (18 isolates) were detected in 3 and 14 subjects, respectively. Among subjects containing ETEC, only one person belonged to normal control group. The detected STEC included two isolates (serotypes O26:H(-) and O111:H(-)) of Shiga toxin type 1 (Stx1-only) STEC from a child with non-bloody diarrhea, two isolates (Stx1-Stx2 STEC and Stx1-only STEC) from an adult with bloody diarrhea, and one isolate of Stx1-Stx2v STEC (O157:H7) from normal child. Only Stx1-Stx2 STEC isolate was found to exhibit toxicity to Vero cells and carry hlyA gene. The intimin encoding gene locus eaeA was not detected in any isolate. These results indicate that most of STEC isolates in Thailand were low virulent.     

Specific primers for PCR amplification of the ITS1 (ribosomal DNA) of Trypanosoma lewisi

Trypanosoma lewisi is a mild or non-pathogenic parasite of the sub-genus Herpetosoma transmitted by fleas to rats. In a previous study we described pan-trypanosome specific primers TRYP1 which amplify the ITS1 of ribosomal DNA by hybridizing in highly conserved regions of 18S and 5.8S genes. These primers proved to be useful for detecting T. lewisi DNA in laboratory rats, but a recent large scale survey in wild rodents demonstrated a lack of specificity. In the present study, we designed and evaluated mono-specific primers LEW1S and LEW1R, for the detection and identification of T. lewisi by a single-step PCR. These primers were designed inside the highly variable region of the ITS1 sequence of T. lewisi ribosomal DNA. The product size of 220 bp is specific to T. lewisi. The sensitivity limit was estimated between 0.055 and 0.55 pg of DNA per reaction, equivalent to 1–10 organisms per reaction. All the PCR products obtained from 6 different T. lewisi isolates were more than 98% similar with each other and similar to the sequences of T. lewisi already published in Genbank. All DNA of 7 T. lewisi stocks from China gave the specific 220 bp product. We showed that LEW1S and LEW1R primers enabled sensitive detection and identification of T. lewisi infection in laboratory and wild rats. This assay is recommended for monitoring T. lewisi infections in rat colonies or for studying infections in the wild fauna. An absence of cross reaction with human DNA means that these primers can be used to investigate atypical trypanosome infections in humans. Given the risk of T. lewisi infection in human, we believe that these primers will be beneficial for public health diagnosis and rodents investigation programmes.     

Asia Pacific Consensus Statements on Crohn's disease. Part 1: Definition,diagnosis, and epidemiology

Inflammatory bowel disease (IBD) was previously thought to be rare in Asia, but emerging data indicate rising incidence and prevalence of IBD in the region. The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology with the goal of developing best management practices, coordinating research, and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis with specific relevance to the Asia‐Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis, and management of Crohn's disease. The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia‐Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses, and treatment availability. It does not intend to be all comprehensive and future revisions are likely to be required in this ever‐changing field.     

Quantitative determination of 1-deoxynojirimycin in mulberry leaves using liquid chromatography-tandem mass spectrometry

A novel HPLC-MS/MS method was developed for the quantitative determination of 1-deoxynojirimycin (DNJ), a potent glucosidase inhibitor present in mulberry leaves (Morus alba L.). DNJ was isolated from the mulberry leave extract on a TSKgel Amide-80 column using a mixture of 0.1% formic acid and acetonitrile as a mobile phase at a flow rate of 0.6 ml/min. A triple quadrupole mass spectrometry using electrospray ionization source in a positive ion mode under multiple reaction monitoring with the [M+H]+ ions, m/z 164.4/109.9 was used. The detection limit (S/N=3) was 75 pg and quantitation limit (S/N=10) was 100 pg. The comparison of mulberry leaves of different ages showed that the DNJ level was higher in mulberry shoots than young and mature leaves.     

Causes of chronic diarrhea in patients with AIDS in Thailand: A prospective clinical and microbiological study

A prospective study was designed to investigate the causes of chronic diarrhea in AIDS patients in Thailand. Forty-five patients from Bamrasnaradura Infectious Diseases Hospital were enrolled. Extensive investigations included multiple stool examinations for ova and parasites, using the stool formalin-ether concentration method, stool culture, stool acid-fast bacilli (AFB) stain, stool modified AFB stain, esophago-gastroduoscopy with duodenal aspirate and biopsy, and colonoscopy with biopsy. Biopsied specimens were examined with H&E, Giemsa, Gram, Periodic acid Schiff, and AFB stains. Definitive causes were found in 29 patients (64.4%). Of these 29, 7 patients were found to habor more than 1 pathogen (15.5%). The most commonly found enteric pathogen wasCryptosporidium parvum (20.0%). Less frequently found pathogens wereMycobacterium tuberculosis (17.8%),Salmonella spp. (15.5%),Cytomegalovirus (11.1%),Mycobacterium avium intracellulare (6.6%), Strongyloides stercoralis (4.4%),Giardia lamblia (4.4%),Cryptococcus neoformans (2.2%),Histoplasma capsulatum (2.2%),Campylobacter jejun (2.2%), andCyclospora cayetanensis (2.2%).Salmonella spp., Mycobacterium tuberculosis, andMycobacterium avium intracellulare infections were shown to be more common in Thailand than in African countries.     

Molecular detection of divergent trypanosomes among rodents of Thailand.

Herpetosoma is a homogenous subgenus of several dozen named species that are often described as morphologically indistinguishable T. lewisi-like parasites. These trypanosomes normally infect rodents and utilize fleas as vectors. Although this trypanosome subgenus is considered non-pathogenic to normal hosts, some of them are on rare occasion reported in association with human disease. Recently, a T. lewisi-like infection was detected in a sick Thai infant, thus the objective of this study was to investigate the prevalence of T. lewisi infections among different rodents indigenous to Thailand in order to identify possible sources of human cases. Blood was collected from a total of 276 rodents trapped from urban and rural areas of three Thai provinces between 2006 and 2007. These samples were processed for DNA isolation and tested with a PCR assay universal for the genus Trypanosoma, followed by internal transcribed spacer 1 (ITS-1) sequence analysis to identify infections in positive samples. Herpetosoma known as T. lewisi-like trypanosomes were present among Rattus (14.3%) and Bandicota (18.0%) rodent species and salivarian trypanosomes closely related to T. evansi were detected in Leopoldamys (20%) and Rattus (2.0%) species. Herpetosoma were prevalent among rodents associated with both human and sylvatic habitats, while three of the four salivaria-positive rodents were from a forest biotope. A Herpetosoma ITS-1 sequence amplified from one of these samples was 97.9% identical to that reported for T. lewisi in an experimentally infected rat and 96.4% identical to the sequence amplified from blood from a Thai infant. Habitats where rodents were collected significantly affect rodent infection, at least for T. lewisi, suggesting that the degree of anthropization may influence the transmission of Trypanosoma spp. These results suggest that multiple Herpetosoma species or strains are enzootic to Thailand, and that Rattus and Bandicota species are possible sources of human exposure to these parasites.     

Molecular detection and identification of Babesia bovis and Babesia bigemina in cattle in northern Thailand

Although Babesia bovis and Babesia bigemina infections cause economic losses in the cattle industry in northern Thailand, there is inadequate information on Babesia isolates present in the area. Therefore, to determine the prevalence and genetic relationship between Babesia isolates, we screened 200 blood samples of cattle from Chiang Rai, Chiang Mai, and Lumpang provinces of northern Thailand. A nested polymerase chain reaction using primers targeting B. bovis spherical body protein 2 (BboSBP2) and B. bigemina rhoptry-associated protein 1a (BbiRAP-1a) genes revealed a prevalence of 12 and 21?% for B. bovis and B. bigemina, respectively, while that of mixed infections was 6.5?% samples. The prevalences of B. bovis in Chiang Rai, Chiang Mai, and Lumpang were 9.5, 3.7, and 25.5?%, respectively. For B. bigemina, the prevalences were 15.8, 12.9, and 39.2?% in Chiang Rai, Chiang Mai, and Lumpang, respectively. Mixed infections with B. bovis and B. bigemina were 6.3?% in Chiang Rai, 1.9?% in Chiang Mai, and 13.7?% in Lumpang. The identical sequences of either BboSBP2 gene or BbiRAP-1a gene were shared among the Babesia isolates in the three provinces of northern Thailand. Further analysis using the internal transcribed spacer gene revealed at least four genotypes for B. bovis and five genotypes for B. bigemina in northern Thailand, while the sequences present great genetic diversities in the different isolates. Overall, we have demonstrated a high prevalence and polymorphism of Babesia parasites in northern Thailand calling for the need to design effective control programs for bovine babesiosis.     

Asia–Pacific consensus statements on Crohn's disease. Part 2: Management

The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology (APAGE) with the goal of developing best management practices, coordinating research and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis (UC) with specific relevance to the Asia‐Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis and management of Crohn's disease (CD). The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia‐Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses and treatment availability. It does not intend to be all‐comprehensive and future revisions are likely to be required in this ever‐changing field.