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

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

Updated Campylobacter jejuni Capsule PCR Multiplex Typing System and Its Application to Clinical Isolates from South and Southeast Asia.

Campylobacter jejuni produces a polysaccharide capsule that is the major determinant of the Penner serotyping scheme. This passive slide agglutination typing system was developed in the early 1980's and was recognized for over two decades as the gold standard for C. jejuni typing. A preliminary multiplex PCR technique covering 17 serotypes was previously developed in order to replace this classic serotyping scheme. Here we report the completion of the multiplex PCR technology that is able to identify all the 47 Penner serotypes types known for C. jejuni. The number of capsule types represented within the 47 serotypes is 35. We have applied this method to a collection of 996 clinical isolates from Thailand, Cambodia and Nepal and were able to successfully determine capsule types of 98% of these

Molecular characterization and PCR-based replicon typing of multidrug resistant Shigella sonnei isolates from an outbreak in Thimphu, Bhutan

BACKGROUND: Shigella species are an important cause of diarrhea in developing countries. These bacteria normally acquire their antibiotic resistance via several different mobile genetic elements including plasmids, transposons, and integrons involving gene cassettes. During a diarrhea surveillance study in Thimphu, Bhutan in June and July, 2011, Shigella sonnei were isolated more frequently than expected. This study describes the antibiotic resistance of these S. sonnei isolates. METHODS: A total of 29 S. sonnei isolates from Thimphu, Bhutan was characterized for antimicrobial susceptibility by disc diffusion assay and minimum inhibitory concentration (MIC) assay. All isolates were tested by pulsed-field gel electrophoresis (PFGE) with restriction enzyme XbaI and were tested for plasmid. The plasmid patterns and the PFGE patterns were analyzed by Bionumerics software. DNA sequencing was performed on amplified products for gyraseA gene and class 1 and class 2 integrons. S. sonnei isolates were classified for incompatibility of plasmids by PCR-based replicon typing (PBRT). RESULTS: These S. sonnei were resistant to multiple drugs like ciprofloxacin, nalidixic acid, trimethoprim-sulfamethoxazole, streptomycin, and tetracycline but susceptible to azithromycin. All isolates had class 2 integrons dfrA1, sat1 and aadA1 genes. Two point mutations in Gyrase A subunit at position Ser83Leu and Asp87Gly were detected in these quinolone resistant isolates. The plasmid and PFGE patterns of S. sonnei isolates suggested a clonal relationship of the isolates. All isolates carried common ColE plasmid. ColE plasmid co-resided with B/O plasmid (nine isolates) or I1 plasmid (one isolate). CONCLUSIONS: The characteristics of 29 S. sonnei isolates from Thimphu, Bhutan in June and July, 2011 are identical in PFGE, plasmid and resistance pattern. This study suggests that these recent S. sonnei isolates are clonally related and multidrug-resistant

Capsule multiplex PCR results among all <i>C</i>. <i>jejuni</i> isolates from different population group from South and South-East Asia.

<p>In bold are the five most prevalent CPS types in their respective group. Number in parentheses represent the number of strain in the category.</p

Summary of the <i>C</i>. <i>jejuni</i> capsule multiplex PCR expected results.

<p>(*) un-expected amplification.</p><p>Summary of the <i>C</i>. <i>jejuni</i> capsule multiplex PCR expected results.</p