PFGE, Lior serotype, and antimicrobial resistance patterns among Campylobacter jejuni isolated from travelers and US military personnel with acute diarrhea in Thailand, 1998-2003

<p>Abstract</p> <p>Background</p> <p><it>Campylobacter jejuni </it>is a major cause of gastroenteritis worldwide. In Thailand, several strains of <it>C. jejuni </it>have been isolated and identified as major diarrheal pathogens among adult travelers. To study the epidemiology of <it>C. jejuni </it>in adult travelers and U.S. military personnel with acute diarrhea in Thailand from 1998-2003, strains of <it>C. jejuni </it>were isolated and phenotypically identified, serotyped, tested for antimicrobial susceptibility, and characterized using pulsed-field gel electrophoresis (PFGE).</p> <p>Results</p> <p>A total of 312 <it>C. jejuni </it>isolates were obtained from travelers (n = 46) and U.S. military personnel (n = 266) in Thailand who were experiencing acute diarrhea. Nalidixic acid and ciprofloxacin resistance was observed in 94.9% and 93.0% of the isolates, respectively. From 2001-2003, resistance to tetracycline (81.9%), trimethoprim-sulfamethoxazole (57.9%), ampicillin (28.9%), kanamycin (5.9%), sulfisoxazole (3.9%), neomycin (2.0%), and streptomycin (0.7%) was observed. Combined PFGE analysis showed considerable genetic diversity among the <it>C. jejuni </it>isolates; however, four PFGE clusters included isolates from the major Lior serotypes (HL: 36, HL: 11, HL: 5, and HL: 28). The PFGE analysis linked individual <it>C. jejuni </it>clones that were obtained at U.S. military exercises with specific antimicrobial resistance patterns.</p> <p>Conclusions</p> <p>In summary, most human <it>C. jejuni </it>isolates from Thailand were multi-resistant to quinolones and tetracycline. PFGE detected spatial and temporal <it>C. jejuni </it>clonality responsible for the common sources of <it>Campylobacter </it>gastroenteritis.</p

Etiology of Acute Diarrheal Disease and Antimicrobial Susceptibility Pattern in Children Younger Than 5 Years Old in Nepal

Diarrhea is a common cause of morbidity and mortality among children younger than 5 years in developing countries. Children from 3 to 60 months of age were recruited from two hospitals in Nepal— Bharatpur Hospital, Bharatpur, and Kanti Children’s Hospital, Kathmandu—in 2006 to 2009. Stool specimens collected from 1,200 children with acute diarrhea (cases) and 1,200 children without diarrhea (control subjects) were examined for a broad range of enteropathogens by standard microbiology, including microscopy, enzyme immunoassay for viral pathogens (adenovirus, astrovirus, and rotavirus) and protozoa (Giardia, Cryptosporidium, and Entamoeba histolytica), as well as by using reverse transcription real-time polymerase for norovirus. Antimicrobial susceptibility testing was performed using the disk diffusion method. Overall, rotavirus (22% versus 2%), norovirus (13% versus 7%), adenovirus (3% versus 0%), Shigella (6% versus 1%), enterotoxigenic Escherichia coli (8% versus 4%), Vibrio (7% versus 0%), and Aeromonas (9% versus 3%) were identified significantly more frequently in cases than control subjects. Campylobacter, Plesiomonas, Salmonella, and diarrheagenic E. coli (enteropathogenic, enteroinvasive, enteroaggregative) were identified in similar proportions in diarrheal and non-diarrheal stools. Campylobacter was resistant to second-generation quinolone drugs (ciprofloxacin and norfloxacin), whereas Vibrio and Shigella were resistant to nalidixic acid and trimethoprim/sulfamethoxazole. This study documents the important role of rotavirus and norovirus in acute diarrhea in children younger than 5 years, followed by the bacteria Shigella, enterotoxigenic E. coli, Vibrio cholera, and Aeromonas. Data on the prevalence and epidemiology of enteropathogens identify potential pathogens for public health interventions, whereas pathogen antibiotic resistance pattern data may provide guidance on choice of therapy in clinical settings.publishedVersio

Distribution of flagella secreted protein and integral membrane protein among <it>Campylobacter jejuni </it>isolated from Thailand

<p>Abstract</p> <p>Background</p> <p><it>Campylobacter jejuni</it>, a gram-negative bacterium, is a frequent cause of gastrointestinal food-borne illness in humans throughout the world. There are several reports that the virulence of <it>C. jejuni </it>might be modulated by non-flagellar proteins that are secreted through the filament. Recently, FspA (Flagella secreted proteins) have been described. Two alleles of <it>fspA </it>(<it>fspA1 </it>and <it>fspA2</it>) based on sequence analysis were previously reported and only the <it>fspA2 </it>allele was found in Thai isolates. The aim of this study is to analyze the deduced amino acid sequences <it>fspA </it>and the adjacent putative integral membrane protein from 103 Thai <it>C. jejuni </it>isolates.</p> <p>Results</p> <p>A total of 103 representative <it>C. jejuni </it>isolates were amplified by PCR for the <it>fspA </it>gene and the adjacent integral membrane protein gene. Two PCR product sizes were amplified using the same primers, an approximately 1600-bp PCR product from 19 strains that contained <it>fspA </it>and integral membrane protein genes and an approximately 800-bp PCR product from 84 strains that contained only the <it>fspA </it>gene. DNA sequencing was performed on the amplified products. The deduced amino acid sequences of both genes were analyzed separately using CLC Free Workbench 4 software. The analysis revealed three groups of FspA. Only FspA group 1 sequences (19/103) (corresponding to <it>fspA1</it>) consisting of 5 subgroups were associated with the adjacent gene encoding the integral membrane protein. FspA group 2 was the largest group (67/103) consisting of 9 subgroups. FspA group 2p (17/103) consisting of 7 subgroups was found to contain stop codons at a position before the terminal 142 position.</p> <p>Conclusions</p> <p>This study reveals greater heterogeneity of FspA (group 1, 2 and 2p) among Thai <it>C. jejuni </it>isolates than previously reported. Furthermore, the subgroups of FspA groups 1 were associated with groups of integral membrane protein. The significance of these different FspA variants to virulence requires further study.</p

Description of novel capsule biosynthesis loci of Campylobacter jejuni clinical isolates from South and South-East Asia.

Campylobacter jejuni is a major cause of bacterial diarrhea worldwide and associated with numerous sequela, including Guillain-Barré Syndrome, inflammatory bowel disease, reactive arthritis, and irritable bowel syndrome. C. jejuni is unusual for an intestinal pathogen in its ability to coat its surface with a polysaccharide capsule (CPS). The genes responsible for the biosynthesis of the phase variable CPS is located in the hypervariable region of C. jejuni genome which has been used to develop multiplex PCR to classify CPS types based on the Penner serotypes. However, there still are non-typable CPS C. jejuni by the current multiplex PCR scheme. The application of the next generation sequencing and whole genome analysis software were used for the identification of novel capsule biosynthesis of C. jejuni isolates. Unique PCR primers were designed to identify these new capsule biosynthesis loci. The designed primers sets were combined in a new multiplex mix called epsilon. The unique sequences provide an additional information of the biosynthesis loci responsible for some of the common CPS sugars/residues such as heptose, deoxtyheptose and MeOPN among C. jejuni in this new group of CPS multiplex assay. This new primer complements the current C. jejuni multiplex capsule typing system and will help in identifying previously untypeable capsule locus of C. jejuni isolates

Incidence of Campylobacter concisus and C. ureolyticus in traveler’s diarrhea cases and asymptomatic controls in Nepal and Thailand

Abstract Background Campylobacter concisus and C. ureolyticus have emerged in recent years as being associated with acute and prolonged gastroenteritis and implicated in the development of inflammatory bowel diseases. However, there are limited data on the prevalence of these microorganisms in Southeast Asia. In this study, 214 pathogen-negative stool samples after laboratory examination for common enteric pathogens to include C. jejuni and C. coli by culture from two case–control traveler’s diarrhea (TD) studies conducted in Thailand (cases = 26; controls = 30) and Nepal (cases = 83; controls = 75) respectively were assayed by PCR for the detection of Campylobacter 16S rRNA and two specific heat shock protein genes specific for C. concisus (cpn60) and C. ureolyticus (Hsp60) respectively. Results Campylobacter 16S rRNA was detected in 28.5% (61/214) of the pathogen-negative TD stool samples (CIWEC Travel Medicine Clinic, Kathmandu, Nepal: cases = 36, control = 14; Bamrungrad International Hospital, Bangkok, Thailand: cases = 9, controls = 2). C. consisus was identified significantly more often in TD cases in Nepal (28.9%; 24/83) as compared to controls (4%; 3/75) (OR = 9.76; 95% CI 2.80–34.02; P = 0.0003) while C. consisus was detected in only two cases (2/26; 7.7%) and none of the controls stool samples from Thailand. C. ureolyticus was detected in four cases (4.8%; 4/83) and four controls (5.3%; 4/75) and in one case (3.8%; 1/26) and one control (3.1%; 1/30) from Nepal and Thailand respectively. C. jejuni and C. coli were isolated in 18.3 and 3.4% of the cases and in 4.0 and 1.4% of the controls in stool samples from both Thailand and Nepal respectively while C. concisus nor C. ureolyticus were not tested for in these samples. Conclusion These findings suggest that C. concisus potentially is a pathogen associated with TD in Nepal. To our knowledge, this is the first report of C. concisus and C. ureolyticus detected from traveler’s diarrhea cases from travelers to Nepal and Thailand