Decrease in shigellosis-related deaths without Shigella spp.-specific interventions, Asia.
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ABSTRACT:
SUBMITTER: Bardhan P
PROVIDER: S-EPMC3294502 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Infection by Shigella spp. is a common cause of dysentery in Southeast Asia. Antimicrobials are thought to be beneficial for treatment; however, antimicrobial resistance in Shigella spp. is becoming widespread. We aimed to assess the frequency and mechanisms associated with decreased susceptibility to azithromycin in Southeast Asian Shigella isolates and use these data to assess appropriate susceptibility breakpoints. Shigella isolates recovered in Vietnam and Laos were screened for susceptibility to azithromycin (15 ?g) by disc diffusion and MIC. Phenotypic resistance was confirmed by PCR amplification of macrolide resistance loci. We compared the genetic relationships and plasmid contents of azithromycin-resistant Shigella sonnei isolates using whole-genome sequences. From 475 available Shigella spp. isolated in Vietnam and Laos between 1994 and 2012, 6/181 S. flexneri isolates (3.3%, MIC ? 16 g/liter) and 16/294 S. sonnei isolates (5.4%, MIC ? 32 g/liter) were phenotypically resistant to azithromycin. PCR amplification confirmed a resistance mechanism in 22/475 (4.6%) isolates (mphA in 19 isolates and ermB in 3 isolates). The susceptibility data demonstrated the acceptability of the S. flexneri (MIC ? 16 g/liter, zone diameter ? 15 mm) and S. sonnei (MIC ? 32 g/liter, zone diameter ? 11 mm) breakpoints with a <3% discrepancy. Phylogenetic analysis demonstrated that decreased susceptibility has arisen sporadically in Vietnamese S. sonnei isolates on at least seven occasions between 2000 and 2009 but failed to become established. While the proposed susceptibility breakpoints may allow better recognition of resistant isolates, additional studies are required to assess the impact on the clinical outcome. The potential emergence of azithromycin resistance highlights the need for alternative options for management of Shigella infections in countries where Shigella is endemic.
| S-EPMC5913960 | biostudies-literature
Project description:Whole-genome sequencing unveiled host and environment-related insights to Shigella sonnei transmission within cyclic epidemics during 2000-2012 in Israel. The Israeli reservoir contains isolates belonging to S. sonnei lineage III but of different origin, shows loss of tetracycline resistance genes, and little genetic variation within the O antigen: highly relevant for Shigella vaccine development.
| S-EPMC6038740 | biostudies-literature
Project description:An unstable chromosomal element encoding multiple antibiotic resistance in Shigella flexneri serotype 2a was found to include sequences homologous to the csg genes encoding curli in Escherichia coli and Salmonella enterica serovar Typhimurium. As curli have been implicated in the virulence of serovar Typhimurium, we investigated the csg loci in all four species of Shigella. DNA sequencing and PCR analysis showed that the csg loci of a wide range of Shigella strains, of diverse serotypes and different geographical distributions, were almost universally disrupted by deletions or insertions, indicating the existence of a strong selective pressure against the expression of curli. Strains of enteroinvasive E. coli (EIEC), which share virulence traits with Shigella spp. and cause similar diseases in humans, also possessed insertions or deletions in the csg locus or were otherwise unable to produce curli. Since the production of curli is a widespread trait in environmental isolates of E. coli, our results suggest that genetic lesions that abolish curli production in the closely related genus Shigella and in EIEC are pathoadaptive mutations.
| S-EPMC97679 | biostudies-literature
Project description:BACKGROUND: Shigellosis is a major public health concern worldwide, especially in developing countries. It is an acute intestinal infection caused by bacteria of the genus Shigella, with a minimum infective dose as low as 10-100 bacterial cells. Increasing prevalence of Shigella sonnei as the etiologic agent of shigellosis in Malaysia has been reported. As there is limited information on the genetic background of S. sonnei in Malaysia, this study aimed to characterize Malaysian S. sonnei and to evaluate the prospect of using multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for subtyping of local S. sonnei. METHODS: Forty non-repeat clinical strains of S. sonnei isolated during the years 1997-2000, and 2007-2009 were studied. The strains were isolated from stools of patients in different hospitals from different regions in Malaysia. These epidemiologically unrelated strains were characterized using biotyping, antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE) and MLVA. RESULTS: The two biotypes identified in this study were biotype a (n?=?29, 73%) and biotype g (n?=?11, 27%). All the 40 strains were sensitive to kanamycin, ceftriaxone and ciprofloxacin. Highest resistance rate was observed for streptomycin (67.5%), followed by tetracycline (40%) and trimethoprim-sulfamethoxazole (37.5%). All the S. sonnei biotype g strains had a core resistance type of streptomycin - trimethoprim-sulfamethoxazole - tetracycline whereas the 29 biotype a strains were subtyped into eight resistotypes. All the strains were equally distinguishable by PFGE and MLVA. Overall, PFGE analysis indicated that S. sonnei biotype a strains were genetically more diverse than biotype g strains. Cluster analysis by MLVA was better in grouping the strains according to biotypes, was reflective of the epidemiological information and was equally discriminative as PFGE. CONCLUSIONS: The S. sonnei strains circulating in Malaysia throughout the period studied were derived from different clones given their heterogeneous nature. MLVA based on seven selected VNTR loci was rapid, reproducible and highly discriminative and therefore may complement PFGE for routine subtyping of S. sonnei.
| S-EPMC3420240 | biostudies-literature
Project description:Nearly 20% of tuberculosis (TB) patients die within one year, and TB-related mortality rates remain high in Taiwan. The study aimed to identify factors correlated with TB-specific deaths versus non-TB-specific deaths in different age groups among TB-related mortalities.A retrospective cohort study was conducted from 2006-2008 with newly registered TB patients receiving follow-up for 1 year. The national TB database from the Taiwan-CDC was linked with the National Vital Registry System and the National Health Insurance database. A chi-squared test and logistic regression were used to analyse the correlated factors related to TB-specific and non-TB-specific deaths in different age groups.Elderly age (odds ratio [OR] 2.68-8.09), Eastern residence (OR 2.01), positive sputum bacteriology (OR 2.54), abnormal chest X-ray (OR 2.28), and comorbidity with chronic kidney disease (OR 2.35), stroke (OR 1.74) or chronic liver disease (OR 1.29) were most likely to be the cause of TB-specific deaths, whereas cancer (OR 0.79) was less likely to be implicated. For non-TB-specific deaths in patients younger than 65 years of age, male sex (OR 2.04) and comorbidity with HIV (OR 5.92), chronic kidney disease (OR 8.02), stroke (OR 3.75), cancer (OR 9.79), chronic liver disease (OR 2.71) or diabetes mellitus (OR 1.38) were risk factors.Different factors correlated with TB-specific deaths compared with non-TB-specific deaths, and the impact of comorbidities gradually decreased as age increased. To reduce TB-specific mortality, special consideration for TB patients with old age, Eastern residence, positive sputum bacteriology and comorbidity with chronic kidney disease or stroke is crucial. In particular, Eastern residence increased the risk of TB-specific death in all age groups. In terms of TB deaths among patients younger than 65 years of age, patients with HIV, chronic kidney disease or cancer had a 6-10 times increased risk of non-TB-specific deaths.
| S-EPMC4348515 | biostudies-other
Project description:Conventional disease surveillance for shigellosis in developing country settings relies on serotyping and low-resolution molecular typing, which fails to contextualise the evolutionary history of the genus. Here, we interrogated a collection of 1,804 Shigella whole genome sequences from organisms isolated in four continental Southeast Asian countries (Thailand, Vietnam, Laos, and Cambodia) over three decades to characterise the evolution of both S. flexneri and S. sonnei. We show that S. sonnei and each major S. flexneri serotype are comprised of genetically diverse populations, the majority of which were likely introduced into Southeast Asia in the 1970s-1990s. Intranational and regional dissemination allowed widespread propagation of both species across the region. Our data indicate that the epidemiology of S. sonnei and the major S. flexneri serotypes were characterised by frequent clonal replacement events, coinciding with changing susceptibility patterns against contemporaneous antimicrobials. We conclude that adaptation to antimicrobial pressure was pivotal to the recent evolutionary trajectory of Shigella in Southeast Asia.
| S-EPMC7979695 | biostudies-literature
Project description:The use of PCR to amplify a specific virA gene fragment serves as a highly specific and sensitive method to detect virulent bacteria of the genus Shigella and enteroinvasive Escherichia coli. Amplification of a 215-bp DNA band was obtained by using isolated genomic DNA of Shigella, individual cells of Shigella dysenteriae, and mayonnaise contaminated with S. dysenteriae. Moreover, a multiplex PCR with specific (virA) and bacterium-restricted (16S ribosomal DNA) primers generated an amplification product of approximately 755 bp for all bacteria tested and an additional 215-bp product for Shigella and enteroinvasive E. coli.
| S-EPMC106136 | biostudies-literature
Project description:Financial distress affects 30-70% of cancer patients and describes the burden that patients experience due to the costs of care (CoC). One reason may be because patients lack the appropriate information on CoC that would help them better plan for and manage their CoC. Therefore, the investigators plan to test a Proactive CoC intervention which includes a discussion with a trained educator on CoC information and a Cost Tracking tool to help patients deal with their CoC.
| 66052 | ecrin-mdr-crc
Project description:Shigellosis, caused by Shigella boydii type 1, is understudied and underreported. For 3 years, GEMS study identified 5.4% of all Shigella as S. boydii. We showed the prevalent serotypes of S. boydii in Bangladesh and phage-based diagnosis of S. boydii type 1, a rapid and low-cost approach. Previously typed 793 clinical S. boydii strains were used for serotype distribution. Twenty-eight environmental water samples were collected for isolation of Shigella phages. Forty-eight serotypes of Shigella and other enteric bacteria were used for testing the susceptibility to phage MK-13. Electron microscopy, restriction enzyme analysis, whole genome sequencing (WGS), and annotation were performed for extensive characterization. S. boydii type 1 is the second most prevalent serotype among 20 serotypes of S. boydii in Bangladesh. We isolated a novel phage, MK-13, which specifically lyses S. boydii type 1, but doesn't lyse other 47 serotypes of Shigella or other enteric bacteria tested. The phage belongs to the Myoviridae family and distinct from other phages indicated by electron microscopy and restriction enzyme analysis, respectively. MK-13 genome consists of 158 kbp of circularly permuted double-stranded DNA with G + C content of 49.45%, and encodes 211 open reading frames including four tRNA-coding regions. The genome has 98% identity with previously reported phage, ?SboM-AG3, reported to have a broader host range infecting most of the S. boydii and other species of Shigella tested. To our knowledge, MK-13 is the first phage reported to be used as a diagnostic marker to detect S. boydii type 1, especially in remote settings with limited laboratory infrastructure.
| S-EPMC6853846 | biostudies-literature
Project description:To determine the clinical manifestations and outcome of shigellosis among children infected with different species of Shigella.We identified all patients <15 years infected with Shigella admitted to the icddr, b Dhaka hospital during one year. Study staff reviewed admission records and repeated the physical examinations and history of patients daily.Of 792 children with shigellosis 63% were infected with S. flexneri, 20% with S. dysenteriae type 1, 10% with S. boydii, 4% with S. sonnei, and 3% with S. dysenteriae types 2-10. Children infected with S. dysenteriae type 1, when compared to children infected with other species, were significantly (P<0.05) more likely to have severe gastrointestinal manifestations: grossly bloody stools (78% vs. 33%), more stools in the 24 h before admission (median 25 vs. 11), and rectal prolapse (52% vs. 15%)--and extra-intestinal manifestations--leukemoid reaction (22% vs. 2%), hemolytic-uremic syndrome (8% vs. 1%), severe hyponatremia (58% vs. 26%) and neurologic abnormalities (24% vs. 16%). The overall fatality rate was 10% and did not differ significantly by species. In a multiple regression analysis young age, malnutrition, hyponatremia, lesser stool frequency, documented seizure, and unconsciousness were predictive of death.Both severe intestinal disease and extra-intestinal manifestations of shigellosis occur with infection by any of the four species of Shigella, but are most common with S. dysenteriae type 1. Among these inpatient children, the risk of death was high with infection of any of the four Shigella species.
| S-EPMC3656950 | biostudies-other