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Archives of Microbiology Jan 2021Shigella sonnei is the emerging pathogen globally, as it is the second common infectious species of shigellosis (bloody diarrhoea) in low- and middle-income countries... (Review)
Review
Shigella sonnei is the emerging pathogen globally, as it is the second common infectious species of shigellosis (bloody diarrhoea) in low- and middle-income countries (LMICs) and the leading one in developed world. The multifactorial processes and novel mechanisms have been identified in S. sonnei, that are collectively playing apart a substantial role in increasing its prevalence, while replacing the S. flexneri and other Gram-negative gut pathogens niche occupancy. Recently, studies suggest that due to improvement in sanitation S. sonnei has reduced cross-immunization from Plesiomonas shigelliodes (having same O-antigen as S. sonnei) and also found to outcompete the two major species of Enterobacteriaceae family (Shigella flexneri and Escherichia coli), due to encoding of type VI secretion system (T6SS). This review aimed to highlight S. sonnei as an emerging pathogen in the light of recent research with pondering aspects on its epidemiology, transmission, and pathogenic mechanisms. Additionally, this paper aimed to review S. sonnei disease pattern and related complications, symptoms, and laboratory diagnostic techniques. Furthermore, the available treatment reigns and antibiotic-resistance patterns of S. sonnei are also discussed, as the ciprofloxacin and fluoroquinolone-resistant S. sonnei has already intensified the global spread and burden of antimicrobial resistance. In last, prevention and controlling strategies are briefed to limit and tackle S. sonnei and possible future areas are also explored that needed more research to unravel the hidden mysteries surrounding S. sonnei.
Topics: Anti-Bacterial Agents; Ciprofloxacin; Drug Resistance, Bacterial; Dysentery, Bacillary; Escherichia coli; Fluoroquinolones; Humans; Shigella flexneri; Shigella sonnei; Type VI Secretion Systems
PubMed: 32929595
DOI: 10.1007/s00203-020-02034-3 -
Clinical Microbiology Reviews Apr 2016After many years in the family Vibrionaceae, the genus Plesiomonas, represented by a single species, P. shigelloides, currently resides in the family Enterobacteriaceae,... (Review)
Review
After many years in the family Vibrionaceae, the genus Plesiomonas, represented by a single species, P. shigelloides, currently resides in the family Enterobacteriaceae, although its most appropriate phylogenetic position may yet to be determined. Common environmental reservoirs for plesiomonads include freshwater ecosystems and estuaries and inhabitants of these aquatic environs. Long suspected as being an etiologic agent of bacterial gastroenteritis, convincing evidence supporting this conclusion has accumulated over the past 2 decades in the form of a series of foodborne outbreaks solely or partially attributable to P. shigelloides. The prevalence of P. shigelloides enteritis varies considerably, with higher rates reported from Southeast Asia and Africa and lower numbers from North America and Europe. Reasons for these differences may include hygiene conditions, dietary habits, regional occupations, or other unknown factors. Other human illnesses caused by P. shigelloides include septicemia and central nervous system disease, eye infections, and a variety of miscellaneous ailments. For years, recognizable virulence factors potentially associated with P. shigelloides pathogenicity were lacking; however, several good candidates now have been reported, including a cytotoxic hemolysin, iron acquisition systems, and lipopolysaccharide. While P. shigelloides is easy to identify biochemically, it is often overlooked in stool samples due to its smaller colony size or relatively low prevalence in gastrointestinal samples. However, one FDA-approved PCR-based culture-independent diagnostic test system to detect multiple enteropathogens (FilmArray) includes P. shigelloides on its panel. Plesiomonads produce β-lactamases but are typically susceptible to many first-line antimicrobial agents, including quinolones and carbapenems.
Topics: Foodborne Diseases; Gram-Negative Bacterial Infections; Humans; Molecular Diagnostic Techniques; Phylogeny; Plesiomonas; Water Microbiology
PubMed: 26960939
DOI: 10.1128/CMR.00103-15 -
Journal of Clinical Microbiology Mar 2015The appropriate treatment and control of infectious gastroenteritis depend on the ability to rapidly detect the wide range of etiologic agents associated with the...
The appropriate treatment and control of infectious gastroenteritis depend on the ability to rapidly detect the wide range of etiologic agents associated with the disease. Clinical laboratories currently utilize an array of different methodologies to test for bacterial, parasitic, and viral causes of gastroenteritis, a strategy that suffers from poor sensitivity, potentially long turnaround times, and complicated ordering practices and workflows. Additionally, there are limited or no testing methods routinely available for most diarrheagenic Escherichia coli strains, astroviruses, and sapoviruses. This study assessed the performance of the FilmArray Gastrointestinal (GI) Panel for the simultaneous detection of 22 different enteric pathogens directly from stool specimens: Campylobacter spp., Clostridium difficile (toxin A/B), Plesiomonas shigelloides, Salmonella spp., Vibrio spp., Vibrio cholerae, Yersinia enterocolitica, enteroaggregative E. coli, enteropathogenic E. coli, enterotoxigenic E. coli, Shiga-like toxin-producing E. coli (stx1 and stx2) (including specific detection of E. coli O157), Shigella spp./enteroinvasive E. coli, Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, Giardia lamblia, adenovirus F 40/41, astrovirus, norovirus GI/GII, rotavirus A, and sapovirus. Prospectively collected stool specimens (n = 1,556) were evaluated using the BioFire FilmArray GI Panel and tested with conventional stool culture and molecular methods for comparison. The FilmArray GI Panel sensitivity was 100% for 12/22 targets and ≥94.5% for an additional 7/22 targets. For the remaining three targets, sensitivity could not be calculated due to the low prevalences in this study. The FilmArray GI Panel specificity was ≥97.1% for all panel targets. The FilmArray GI Panel provides a comprehensive, rapid, and streamlined alternative to conventional methods for the etiologic diagnosis of infectious gastroenteritis in the laboratory setting. The potential advantages include improved performance parameters, a more extensive menu of pathogens, and a turnaround time of as short as 1 h.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Bacteria; Child; Child, Preschool; Feces; Female; Gastroenteritis; Humans; Infant; Infant, Newborn; Male; Microbiological Techniques; Middle Aged; Molecular Diagnostic Techniques; Parasites; Prospective Studies; Sensitivity and Specificity; Time Factors; Viruses; Young Adult
PubMed: 25588652
DOI: 10.1128/JCM.02674-14 -
BMC Microbiology Dec 2022RpoN, also known as σ, first reported in Escherichia coli, is a subunit of RNA polymerase that strictly controls the expression of different genes by identifying...
BACKGROUND
RpoN, also known as σ, first reported in Escherichia coli, is a subunit of RNA polymerase that strictly controls the expression of different genes by identifying specific promoter elements. RpoN has an important regulatory function in carbon and nitrogen metabolism and participates in the regulation of flagellar synthesis, bacterial motility and virulence. However, little is known about the effect of RpoN in Plesiomonas shigelloides.
RESULTS
To identify pathways controlled by RpoN, RNA sequencing (RNA-Seq) of the WT and the rpoN deletion strain was carried out for comparison. The RNA-seq results showed that RpoN regulates ~ 13.2% of the P. shigelloides transcriptome, involves amino acid transport and metabolism, glycerophospholipid metabolism, pantothenate and CoA biosynthesis, ribosome biosynthesis, flagellar assembly and bacterial secretion system. Furthermore, we verified the results of RNA-seq using quantitative real-time reverse transcription PCR, which indicated that the absence of rpoN caused downregulation of more than half of the polar and lateral flagella genes in P. shigelloides, and the ΔrpoN mutant was also non-motile and lacked flagella. In the present study, the ability of the ΔrpoN mutant to kill E. coli MG1655 was reduced by 54.6% compared with that of the WT, which was consistent with results in RNA-seq, which showed that the type II secretion system (T2SS-2) genes and the type VI secretion system (T6SS) genes were repressed. By contrast, the expression of type III secretion system genes was largely unchanged in the ΔrpoN mutant transcriptome and the ability of the ΔrpoN mutant to infect Caco-2 cells was also not significantly different compared with the WT.
CONCLUSIONS
We showed that RpoN is required for the motility and contributes to the killing ability of P. shigelloides and positively regulates the T6SS and T2SS-2 genes.
Topics: Humans; RNA Polymerase Sigma 54; Gene Expression Regulation, Bacterial; Plesiomonas; Bacterial Proteins; Escherichia coli; Caco-2 Cells
PubMed: 36510135
DOI: 10.1186/s12866-022-02722-8 -
Antibiotics (Basel, Switzerland) Jan 2022are gram-negative, thermotolerant, motile, and pleomorphic microorganisms that are only distantly related to those of the Enterobacteriaceae and Vibrionaceae families....
are gram-negative, thermotolerant, motile, and pleomorphic microorganisms that are only distantly related to those of the Enterobacteriaceae and Vibrionaceae families. One of the most common sources of contamination is human stool, but it may also be found in a wide range of other animals, plants, and aquatic habitats. Antimicrobial resistance in from seawater and shellfish was investigated, and pathogenicity involved genes were characterized as part of this study. Out of 384 samples of shellfish, 5.7% included . The presence of was also discovered in 5% of the seawater sampled. The antimicrobial resistance of 23 isolates derived from those samples was investigated. All isolates were sensitive to nalidixic acid, carbenicillin, cephalothin, erythromycin, kanamycin, tetracycline, and ciprofloxacin in the study. Several strains isolated from diseased shellfish were tested for virulence in shellfish by intraperitoneal injections. The LD values ranged from 12 × 10 to 3 × 10 cfu/shellfish. When looking for possible virulence factors that may play a significant role in bacterial infection in the current study, we found that all of these genes were present in these strains. These include genes such as elastase, lipase, flagellin, enterotoxin, and DNases. According to these findings, shellfish may serve as a reservoir for multi-resistant and help spread virulence genes across the environment.
PubMed: 35052962
DOI: 10.3390/antibiotics11010085 -
Japanese Journal of Infectious Diseases Jul 2022The genus Plesiomonas, represented by a single species, Plesiomonas shigelloides, is a gram-negative bacillus associated with gastrointestinal and extraintestinal...
The genus Plesiomonas, represented by a single species, Plesiomonas shigelloides, is a gram-negative bacillus associated with gastrointestinal and extraintestinal diseases in humans. In this study, 44 clinical isolates (gastrointestinal, n = 41; extraintestinal, n = 3) were genetically confirmed to be P. shigelloides using the hug gene. All 20 virulence genes were detected in the gastrointestinal isolates, ranging from 7.7% to 100%; however, only 12 genes were detected in the extra-gastrointestinal isolates, ranging from 33.3% to 100%. The phlA gene was significantly associated with the gastrointestinal isolates (P = 0.0216). The results of this study suggest that phlA may play a role in gastrointestinal infections. However, pilF, tolC, and fur were detected in both gastrointestinal and extraintestinal clinical isolates, and further investigations are warranted to elucidate their role in the pathogenesis of P. shigelloides.
Topics: Gram-Negative Bacterial Infections; Humans; Plesiomonas; Virulence
PubMed: 35095023
DOI: 10.7883/yoken.JJID.2021.477 -
Frontiers in Immunology 2022Various bacterial diseases have caused great economic losses to the high-density and intensive aquaculture industry; however, the pathogenic mechanism underlying the...
Various bacterial diseases have caused great economic losses to the high-density and intensive aquaculture industry; however, the pathogenic mechanism underlying the large-scale challenged to caused by many bacteria remain unclear, making the prevention and treatment of these diseases difficult. In the present study, we isolated a bacterial strain from having a typical bacterial disease and named it Cc2021. Through subsequent morphological observations, a regression challenge, biochemical identification, and 16S rRNA gene sequence analysis, we determined Cc2021 to be . Subsequently, we comprehensively investigated the pathogenicity of in through a regression challenge and assessed the underlying the pathogenic mechanism. Mortality results revealed that is highly pathogenic and infects various tissues throughout the body, resulting in edema of the liver, spleen, and body and head kidneys. Histopathological analysis revealed obvious inflammation, bleeding, and necrosis in the intestine, spleen, and head kidney. The body's immune tissues actively produce complement C3, superoxide dismutase, and lysozyme after a challenge to resist bacterial invasion. With regard to the underlying pathogenesis of , comparative transcriptome analysis revealed 876 upregulated genes and 828 downregulated genes in the intestine of after the challenge. Analysis of differentially expressed unigenes revealed the involvement of major immune pathways, particularly the TNF signaling pathway, interleukin (IL)-17 signaling pathway, and Toll-like receptor signaling pathway. The present study provides new valuable information on the immune system and defense mechanisms of .
Topics: Animals; Carps; Plesiomonas; RNA, Ribosomal, 16S; Transcriptome; Virulence
PubMed: 35844551
DOI: 10.3389/fimmu.2022.872896 -
Microorganisms Jul 2020Molecular signatures of strain specific to pathogenic and nonpathogenic variants are not well established till present. There is a need for intra-species barcoding of...
Molecular signatures of strain specific to pathogenic and nonpathogenic variants are not well established till present. There is a need for intra-species barcoding of to aid infection control. This study aims at characterizing and assessing intra-species diversity and abundance of isolated from three freshwaters in the Eastern Cape Province. The study used a Plesiomonas-specific PCR to characterize the isolates. Intra-species (dis)similarities were assessed using ERIC-PCR and (GTG)5-PCR techniques. The DNA fingerprints produced were electrophoresed, digitized, and documented via computer-assisted pattern analysis. The fingerprints were analyzed using neighbor-joining clustering (NJC) based on Euclidean similarity index. Results revealed 80%, 83.64%, and 80% of the water samples from Tyhume, Kat, and Kubusie rivers, respectively, positive for isolation. The prevalence of from sites ranged from 13.5% to 88.9%. NJC delineated 48 isolates to 8 clades (ERIC-fingerprints) and 34 isolates into 7 clades ((GTG)5-fingerprints). The relative abundance of unique strains ranged from 6.3% to 22.9% via the two methods. Both fingerprinting approaches have strain-differentiating potential for , however ERIC-PCR possessed higher resolution ( = 37.46) advantage over (GTG)5-PCR ( = 29.64). In conclusion, the study achieved intra-species diversity and abundance of from aquatic milieu and provide further opportunity for intra-species-specific barcoding.
PubMed: 32698489
DOI: 10.3390/microorganisms8071081 -
MSystems Sep 2020is an emerging pathogen that has been shown to be involved in gastrointestinal diseases and extraintestinal infections in humans. However, the taxonomic position,...
is an emerging pathogen that has been shown to be involved in gastrointestinal diseases and extraintestinal infections in humans. However, the taxonomic position, evolutionary dynamics, and pathogenesis of remain unclear. We reported the draft genome sequences of 12 strains representing different serogroups. We were able to determine a clear distinction between and other members of via core genome phylogeny, Neighbor-Net network, and average genome identity analysis. The pan-genome analysis of revealed extensive genetic diversity and presented large flexible gene repertoires, while the core genome phylogeny exhibited a low level of clonality. The discordance between the core genome phylogeny and the pan-genome phylogeny indicated that flexible accessory genomes account for an important proportion of the evolution of , which was subsequently characterized by determinations of hundreds of horizontally transferred genes (horizontal genes), massive gene expansions and contractions, and diverse mobile genetic elements (MGEs). The apparently high levels of horizontal gene transfer (HGT) in were conferred from bacteria with novel properties from other taxa (mainly and ), which caused the historical taxonomic confusion and shaped the virulence gene pools. Furthermore, genomes contain many macromolecular secretion system genes, virulence factor genes, and resistance genes, indicating its potential to cause intestinal and invasive infections. Collectively, our work provides insights into the phylogenetic position, evolutionary dynamic, and pathogenesis of at the genomic level, which could facilitate the observation and research of this important pathogen. The taxonomic position of has been the subject of debate for a long time, and until now, the evolutionary dynamics and pathogenesis of were unclear. In this study, pan-genome analysis indicated extensive genetic diversity and the presence of large and variable gene repertoires. Our results revealed that horizontal gene transfer was the focal driving force for the genetic diversity of the pan-genome and might have contributed to the emergence of novel properties. and were found to be the predominant donor taxa for horizontal genes, which might have caused the taxonomic confusion historically. Comparative genomic analysis revealed the potential of to cause intestinal and invasive diseases. Our results could advance the understanding of the evolution and pathogenesis of , particularly in elucidating the role of horizontal gene transfer and investigating virulence-related elements.
PubMed: 32934114
DOI: 10.1128/mSystems.00448-20 -
Frontiers in Microbiology 2015Plesiomonas shigelloides is the unique member of the Enterobacteriaceae family able to produce polar flagella when grow in liquid medium and lateral flagella when grown...
Plesiomonas shigelloides is the unique member of the Enterobacteriaceae family able to produce polar flagella when grow in liquid medium and lateral flagella when grown in solid or semisolid media. In this study on P. shigelloides 302-73 strain, we found two different gene clusters, one exclusively for the lateral flagella biosynthesis and the other one containing the biosynthetic polar flagella genes with additional putative glycosylation genes. P. shigelloides is the first Enterobacteriaceae were a complete lateral flagella cluster leading to a lateral flagella production is described. We also show that both flagella in P. shigelloides 302-73 strain are glycosylated by a derivative of legionaminic acid (Leg), which explains the presence of Leg pathway genes between the two polar flagella regions in their biosynthetic gene cluster. It is the first bacterium reported with O-glycosylated Leg in both polar and lateral flagella. The flagella O-glycosylation is essential for bacterial flagella formation, either polar or lateral, because gene mutants on the biosynthesis of Leg are non-flagellated. Furthermore, the presence of the lateral flagella cluster and Leg O-flagella glycosylation genes are widely spread features among the P. shigelloides strains tested.
PubMed: 26167161
DOI: 10.3389/fmicb.2015.00649