Pediatric campylobacteriosis in northern Taiwan from 2003 to 2005

<p>Abstract</p> <p>Background</p> <p>There has been a marked increase in the incidence of, and concern regarding, human <it>Campylobacter jejuni </it>and <it>C. coli </it>infections worldwide during the last decade. As the highest infectious disease control apparatus in Taiwan, we aimed to describe the character of <it>Campylobacter </it>isolates from infected children, as well as basic information about the patients, from December 2003 to February 2005.</p> <p>Methods</p> <p>A total of 894 fecal specimens were collected by several clinics and hospitals from children who had diarrhea, followed by plating onto selective media. Drug susceptibility test of the isolates from these specimens were conducted by disc diffusion method and their serotypes were also studied using commercial antisera made in Japan.</p> <p>Results</p> <p>The isolation rate of <it>Campylobacter </it>during these 15 months was 6.8% and was higher in winter (11.1%) than in other seasons. <it>C. jejuni </it>was the most prevalent (95.1%) species in northern Taiwan, comparable to other developed countries. Among the 61 <it>Campylobacter </it>isolates, most were resistant to tetracycline (93.4%), nalidixic acid (91.8%), ciprofloxacin (90.2%), and ampicillin (85.5%). Erythromycin-resistant isolates represented 3.3% of all isolates, suggesting that this drug may be the first choice for treatment. The serotypes of the 61 isolates were demonstrated and only 41.4% were typable.</p> <p>Conclusion</p> <p>In this study, the Taiwan CDC provided an epidemiological analysis of <it>Campylobacter </it>infection, including the isolation rate, age, seasonal distribution, antimicrobial drug susceptibility patterns, and serotypes of the isolates from pediatric patients in northern Taiwan from 2003 to 2005.</p

Genotyping and antibiotic resistance of thermophilic Campylobacter isolated from chicken and pig meat in Vietnam

Background Campylobacter species are recognized as the most common cause of foodborne bacterial gastroenteritis in humans. In this study nine Campylobacter strains isolated from chicken meat and pork in Hanoi, Vietnam, were characterized using molecular methods and tested for antibiotic resistance. Results The nine isolates (eight C. jejuni and one C. coli) were identified by multiplex PCR, and tested for the presence or absence of 29 gene loci associated with virulence, lipooligosaccharide (LOS) biosynthesis and further functions. flaA typing, multilocus sequence typing and microarray assay investigation showed a high degree of genetic diversity among these isolates. In all isolates motility genes (flaA, flaB, flhA, fliM), colonization associated genes (cadF, docB), toxin production genes (cdtA, cdtB, secD, secF), and the LOS biosynthesis gene pglB were detected. Eight gene loci (fliY, virB11, Cje1278, Cj1434c, Cj1138, Cj1438c, Cj1440c, Cj1136) could not be detected by PCR. A differing presence of the gene loci ciaB (22.2 %), Cje1280 (77.8 %), docC (66.7 %), and cgtB (55.6 %) was found. iamA, cdtC, and the type 6 secretion system were present in all C. jejuni isolates but not in C. coli. flaA typing resulted in five different genotypes within C. jejuni, MLST classified the isolates into seven sequence types (ST-5155, ST-6736, ST-2837, ST-4395, ST-5799, ST-4099 and ST-860). The microarray assay analysis showed a high genetic diversity within Vietnamese Campylobacter isolates which resulted in eight different types for C. jejuni. Antibiotic susceptibility profiles showed that all isolates were sensitive to gentamicin and most isolates (88.8 %) were sensitive to chloramphenicol, erythromycin and streptomycin. Resistance rates to nalidixic acid, tetracycline and ciprofloxacin were 88.9, 77.8 and 66.7 %, respectively. Conclusions To the best of our knowledge, this study is the first report that shows high genetic diversity and remarkable antibiotic resistance of Campylobacter strains isolated from meat in Vietnam which can be considered of high public health significance. These preliminary data show that large scale screenings are justified to assess the relevance of Campylobacter infections on human health in Vietnam

Key Role of Mfd in the Development of Fluoroquinolone Resistance in Campylobacter jejuni

Campylobacter jejuni is a major food-borne pathogen and a common causative agent of human enterocolitis. Fluoroquinolones are a key class of antibiotics prescribed for clinical treatment of enteric infections including campylobacteriosis, but fluoroquinolone-resistant Campylobacter readily emerges under the antibiotic selection pressure. To understand the mechanisms involved in the development of fluoroquinolone-resistant Campylobacter, we compared the gene expression profiles of C. jejuni in the presence and absence of ciprofloxacin using DNA microarray. Our analysis revealed that multiple genes showed significant changes in expression in the presence of a suprainhibitory concentration of ciprofloxacin. Most importantly, ciprofloxacin induced the expression of mfd, which encodes a transcription-repair coupling factor involved in strand-specific DNA repair. Mutation of the mfd gene resulted in an approximately 100-fold reduction in the rate of spontaneous mutation to ciprofloxacin resistance, while overexpression of mfd elevated the mutation frequency. In addition, loss of mfd in C. jejuni significantly reduced the development of fluoroquinolone-resistant Campylobacter in culture media or chickens treated with fluoroquinolones. These findings indicate that Mfd is important for the development of fluoroquinolone resistance in Campylobacter, reveal a previously unrecognized function of Mfd in promoting mutation frequencies, and identify a potential molecular target for reducing the emergence of fluoroquinolone-resistant Campylobacter

Rethinking “(Under) Performance” for Black English Speakers: Beyond Achievement to Opportunity

We draw on the concept of the opportunity gap explanatory framework in this study to problematize the notion of “(under)performance” of Black American (i.e., African American) and Black immigrant youth. Examining reading literacy achievement results of Black American and Black immigrant youth using a corpus of data from the 2012 Program for International Student Assessment (PISA), we demonstrate the ways in which these youth self-identified as language speakers on the PISA reading literacy assessment measure, the influence of this self-identification on interpretations of their reading literacy, and the influence of other demographic factors on this achievement across subgroups. We suggest that the disaggregation of data for Black subpopulations can allow for a better understanding of the ways in which demographic, social, and cultural factors impact achievement within specific Black subgroups. We also highlight the need for reframing examinations of Black students’ literacies in ways that are humanizing. Implications for research, practice, and policy are provided

Abundance, viability and diversity of the indigenous microbial populations at different depths of the NEEM Greenland ice core

The 2537-m-deep North Greenland Eemian Ice Drilling (NEEM) core provided a first-time opportunity to perform extensive microbiological analyses on selected, recently drilled ice core samples representing different depths, ages, ice structures, deposition climates and ionic compositions. Here, we applied cultivation, small subunit (SSU) rRNA gene clone library construction and Illumina next-generation sequencing (NGS) targeting the V4–V5 region, to examine the microbial abundance, viability and diversity in five decontaminated NEEM samples from selected depths (101.2, 633.05, 643.5, 1729.75 and 2051.5 m) deposited 300–80 000 years ago. These comparisons of the indigenous glacial microbial populations in the ice samples detected significant spatial and temporal variations. Major findings include: (a) different phylogenetic diversity of isolates, dominated by Actinobacteria and fungi, compared to the culture-independent diversity, in which Proteobacteria and Firmicutes were more frequent; (b) cultivation of a novel alphaproteobacterium; (c) dominance of Cyanobacteria among the SSU rRNA gene clones from the 1729.75-m ice; (d) identification of Archaea by NGS that are rarely detected in glacial ice; (e) detection of one or two dominant but different genera among the NGS sequences from each sample; (f) finding dominance of Planococcaceae over Bacillaceae among Firmicutes in the brittle and the 2051.5-m ice. The overall beta diversity between the studied ice core samples examined at the phylum/class level for each approach showed that the population structure of the brittle ice was significantly different from the two deep clathrated ice samples and the shallow ice core