Prevalence of enterotoxigenic Escherichia coli (ETEC) in hospitalized acute diarrhea patients in Denpasar, Bali, Indonesia.

The relationship between enterotoxigenic Escherichia coli (ETEC) and hospitalized patients with acute diarrhea was examined in a study conducted in two hospitals from June 2000 to May 2001 in Denpasar, Bali, Indonesia. A total of 489 hospitalized patients with acute diarrhea were enrolled, and their rectal swabs were screened for enteric bacterial pathogens. Toxins, colonization factor antigens (CFAs), in vitro antimicrobial susceptibility and seasonal distribution patterns associated with ETEC were ascertained. The diagnosis of ETEC infection and CFAs association were performed with GM-1 ELISA and Dot blot immunoassays. Enterotoxigenic Escherichia coli was isolated from the rectal swabs of 14.9% of the patients. The distribution of toxins among the ETEC strains found was ST in 51 (69.9%), while LT and ST/LT were found in 28.8% and 1.3% respectively. The highest isolation rate for ETEC was found among children between the ages of 1 and 15 years. Colonization factor antigens were identified in 28.8% of the ETEC strains. A high prevalence of CFA was found among the rectal swabs of patients with ST isolates. High frequency of resistance to ampicillin, trimethoprim/sulfamethoxazole, chloramphenicol, tetracycline and cephalothin was displayed among the ETEC strains. All ETEC strains were susceptible to norfloxacin, ciprofloxacin and nalidixic acid. The results of this study document the prevalence of ETEC in hospitalized patients with acute diarrhea in Denpasar, Bali, Indonesia. Data generated in this study depicts the prevalence of ETEC diarrhea and CFA types among diarrhea patients in the tourist city of Denpasar, Bali, Indonesia.

Characterization of Norwalk-like virus associated with gastroenteritis in Indonesia.

Norwalk Virus and Norwalk-like viruses (NLVs) are reportedly responsible for 2.5-4.0% of nonbacterial acute gastroenteritis (NBAG) worldwide. To help clarify the impact of NLVs on NBAG in Indonesia, stool specimens from 102 patients, 74 with NBAG and 28 with BAG, were screened for the presence of NLVs, using a reverse transcription-polymerase chain reaction (RT-PCR) assay. The specimens were subtyped using prototype-specific oligonucleotide probes and were sequenced and compared with published NLV sequences. Of the 102 specimens examined, 31 (30%) were found to be positive for NLVs. Type-specific probe analysis of the RT-PCR products indicated that 31 isolates hybridized to UK1 (Taunton agent) and UK3/4 (Hawaii agent/Snow Mountain agent) prototype strains. The results of this study indicate that prototype strains of NV or NLVs co-circulate in Indonesia and contribute to the overall level of acute gastroenteritis throughout the region.

Experimental infection of Macaca nemestrina with a Toronto Norwalk-like virus of epidemic viral gastroenteritis.

Norwalk virus (NV) and Norwalk-like viruses (NLVs) are common etiologic agents of viral gastroenteritis. Viral gastroenteritis is a common disease that is highly transmissible, spreading rapidly through families, institutions, and communities. Because methods for in vitro cultivation of Norwalk etiologic agents are not available, information regarding this syndrome has come largely from studies in human volunteers. Sequential passaging of an NLV through an immunoincompetent newborn pigtail macaque (Macaca nemestrina) may allow for the adaptation of a human NLV to a primate host, thus providing an animal model for investigating this disease. A fecal filtrate of human origin containing NLV, Toronto virus P2-A, was obtained from a patient during an epidemic of viral gastroenteritis. The filtrate was administered via nasogastric tube to three newborn pigtailed macaques. Clinical illness, which was characterized by diarrhea, dehydration, and vomiting, occurred in three monkeys. Reverse transcription-polymerase chain reaction (RT-PCR) and oligonucleotide probe analysis of RNA extracted from the stool samples following infection revealed viral RNA in all inoculated monkeys. Infection was also transmitted experimentally by feeding two additional newborn macaques a fecal filtrate prepared from the three previously infected animals. Detection of viral RNA in the stools of animals that received the fecal filtrate indicates that viral replication occurred in association with clinical illness. The susceptibility of Macaca nemestrina to infection with a Norwalk-like agent will facilitate the study of the mechanisms of the pathogenesis of NLV. This system may also have the potential to serve as a vaccine test model for human epidemic viral gastroenteritis.

Toxins and colonization factor antigens of enterotoxigenic Escherichia coli among residents of Jakarta, Indonesia.

Infection caused by enterotoxigenic Escherichia coli (ETEC) poses a serious health problem among children and adults in developing countries. Colonization of the small intestinal mucosa by ETEC strains is mediated by antigenically specific fimbriae, also known as colonization factor antigens (CFA). The significance of this study arises from reports that active and passive immunization with ETEC strains harboring CFAs has previously been shown to induce protective immunity against diarrhea in animal models. The aim of this study was to determine toxin-associated CFAs of ETEC isolated from a diarrheal disease case-control study in Jakarta, Indonesia. Thirteen hundred and twenty-three diarrheic and control patients with lactose-fermenting colonies were screened by ganglioside GM1-enzyme-linked immunosorbent assay (GM1-ELISA) for heat-labile (LT) and heat-stable (ST) toxins. Two hundred and forty-six (19%) ETEC isolates identified by GM1-ELISA for the LT/ST toxins were screened for CFAs by Dot blot assay using monoclonal antibodies against CFA/I, II, and IV and against the putative colonization antigens (PCF) PCFO159, PCFO166, CS7, and CS17. Of the 246 ETEC isolates, 177 (72%) elaborated ST, 56 (23%) produced LT, while 13 (5%) elicited both the ST and LT toxins. CFA testing of the 246 ETEC isolates showed that 21 (8%) expressed CFA/I, 3 (1%) exhibited CFA/II, 14 (6%) elaborated CFA/IV, while 7 (3%) expressed PCFO159 and PCFO159 plus CS5. No CFAs or PCFs could be associated with 201 (82%) of the ETEC strains. This report documents the types of CFAs associated with ETEC strains in Jakarta, Indonesia. These data may help current research efforts on the development of CFA-based vaccines for humans against ETEC and provide additional information for future ETEC vaccine trials in Southeast Asia.