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Genes & Genetic Systems Apr 2001Flagellin (fliC) genes of 12 Shigella boydii and five Shigella dysenteriae strains were characterized. Though these strains are nonmotile, the cryptic fliCSB gene,...
Flagellin (fliC) genes of 12 Shigella boydii and five Shigella dysenteriae strains were characterized. Though these strains are nonmotile, the cryptic fliCSB gene, cloned from S. boydii strain C3, is functional for expression of flagellin. It consists of 1,704 bp, and encodes 568 amino acid residues (57,918 Da). The fliCSD gene from S. dysenteriae strain 16 consists of 1,650 bp encoding 549 amino acid residues (57,591 Da) and contains an IS1 element inserted in its 3' end. The two genes are composed of the 5'-constant, central variable and 3'-constant sequences, like other known fliC genes. The two genes share high homology in nucleotide and amino acid sequences with each other and also with the Escherichia coli fliCE gene, indicating that both genes are closely related to the fliCE gene. Comparison of the central variable sequences of six different fliC genes showed that the fliCSB and fliCSD genes share low homology in amino acid sequence with the other fliC genes, suggesting that they encode antigenic determinants intrinsic to respective subgroups. However, Southern blotting using as probes the central variable sequences of several fliC genes showed that four of 12 S. boydii strains have a fliC gene similar to that of Shigella flexneri, and that among five fliC genes from S. dysenteriae strains, one is similar to that of S. flexneri, two are similar to that of S. boydii, and only one is unique to S. dysenteriae. Some of these variant alleles were verified by immunoblotting with flagellins produced from cloned fliC genes. The presence of variant fliC alleles in S. boydii and S. dysenteriae indicates that subdivision into subgroups does not reflect the ancestral flagella H antigenic relationships. These data will be useful in considering the evolutionary divergence of the Shigella spp..
Topics: Alleles; Amino Acid Sequence; Blotting, Southern; Cloning, Molecular; Electrophoresis, Polyacrylamide Gel; Evolution, Molecular; Flagellin; Genetic Variation; Immunoblotting; Models, Genetic; Molecular Sequence Data; Plasmids; Sequence Analysis, DNA; Shigella boydii; Shigella dysenteriae; Species Specificity
PubMed: 11434456
DOI: 10.1266/ggs.76.111 -
Journal of Health, Population, and... Nov 2016Shigella is a major cause of gastroenteritis especially in children. In developing countries, the incidence is frequent and results are often life threatening. Changing...
BACKGROUND
Shigella is a major cause of gastroenteritis especially in children. In developing countries, the incidence is frequent and results are often life threatening. Changing epidemiology and emerging antibiotic resistance warrants continuous monitoring of susceptibility. The present study highlights the changing epidemiology and drug resistance patterns of Shigella isolated at different hospitals of Nepal over a period of 13 years (Jan. 2003-Dec. 2015).
METHODS
This study was carried out in 12 participating laboratories. Stool specimens received at respective laboratories were processed for isolation and identification of Shigella species and confirmed by serotyping at National Public Health Laboratory. Antimicrobial resistance patterns were determined by Kirby Baeur disc diffusion test.
RESULTS
A total of 332 isolates were identified as Shigella species of which Shigella flexneri (50 %) was the predominant serotype. Shigella dysenteriae, Shigella sonnei, Shigella boydii, and untypable Shigella spp. respectively, accounted for 28.6, 27.54, 10.2, 4.5, and 6.6 % of the total number. Change in prevalent serotype is noted over the years. S. dysenteriae was the prevalent species in Nepal in 2003 and 2004, but since 2005, S. flexneri remained prevalent. Majority of the isolates were recovered from children aged 1-10 years and was statistically significant (p = 0.023) compared to the other age groups. High resistance among all Shigella species to the first-line drugs like ampicillin (88 %), cotrimoxazole (76 %), ciprofloxacin (39 %,) and nalidixic acid (80 %) was observed; 46.1 % of total isolates were multidrug resistant (MDR), and the most common MDR profile was ampicillin, nalidixic acid, and co-trimoxazole. Prevalence of MDR increased significantly in 2010 as compared to 2003. Only few Shigella isolates were resistant to ceftriaxone.
CONCLUSIONS
The study revealed S. flexneri as the predominant serogroup in Nepal. Children below 10 years were more prone to the disease. Nalidixic acid, ampicillin, co-trimoxazole, and ciprofloxacin should not be used empirically as the first-line drugs in treatment of shigellosis. Since the distribution of different species of Shigella and their antibiotic susceptibility profile may vary from one geographical location to another and may also change with time, continuous local monitoring of resistance patterns is necessary for appropriate antimicrobial therapy.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Drug Resistance, Bacterial; Drug Resistance, Multiple; Dysentery, Bacillary; Female; Hospitals; Humans; Infant; Male; Microbial Sensitivity Tests; Middle Aged; Nepal; Prevalence; Serogroup; Shigella; Shigella dysenteriae; Shigella flexneri; Young Adult
PubMed: 27814742
DOI: 10.1186/s41043-016-0073-x -
Plant, Cell & Environment Nov 2019Shigella, which infects primates, can be transmitted via fresh vegetables; however, its molecular interactions with plants have not been elucidated. Here, we show that...
Shigella, which infects primates, can be transmitted via fresh vegetables; however, its molecular interactions with plants have not been elucidated. Here, we show that four Shigella strains, Shigella boydii, Shigella sonnei, Shigella flexneri 2a, and S. flexneri 5a, proliferate at different levels in Arabidopsis thaliana. Microscopic studies revealed that these bacteria were present inside leaves and damaged plant cells. Green fluorescent protein (GFP)-tagged S. boydii and S. flexneri 5a colonized leaves only, whereas S. flexneri 2a colonized both leaves and roots. Using Shigella mutants lacking type III secretion systems (T3SSs), we found that T3SSs that regulate the pathogenesis of shigellosis in humans also play a central role in bacterial proliferation in Arabidopsis. Strikingly, the immunosuppressive activity of two T3S effectors, OspF and OspG, was required for proliferation of Shigella in Arabidopsis. Of note, delivery of OspF or OspG effectors inside plant cells upon Shigella inoculation was confirmed using a split GFP system. These findings demonstrate that the human pathogen Shigella can proliferate in plants by adapting immunosuppressive machinery used in the original host human.
Topics: Arabidopsis; Bacterial Outer Membrane Proteins; Gene Expression Regulation, Plant; Plant Cells; Plant Diseases; Plant Leaves; Plants, Genetically Modified; Shigella; Signal Transduction; Type III Secretion Systems; Virulence Factors
PubMed: 31250458
DOI: 10.1111/pce.13603 -
Journal of Bacteriology Jan 2004Shigella is an important human pathogen. It is generally agreed that Shigella and Escherichia coli constitute a single species; the only exception is Shigella boydii...
Shigella is an important human pathogen. It is generally agreed that Shigella and Escherichia coli constitute a single species; the only exception is Shigella boydii type 13, which is more distantly related to E. coli and other Shigella forms and seems to represent another species. This gives S. boydii type 13 an important status in evolution. O antigen is the polysaccharide part of the lipopolysaccharide in the outer membrane of gram-negative bacteria and plays an important role in pathogenicity. The chemical structure and genetic organization of the S. boydii type 13 O antigen were investigated. The O polysaccharide was found to be acid labile owing to the presence of a glycosyl phosphate linkage in the main chain. The structure of the linear pentasaccharide phosphate repeating unit (O unit) was established by nuclear magnetic resonance spectroscopy, including two-dimensional COSY, TOCSY, ROESY, and H-detected 1H, 13C and 1H, 31P HMQC experiments, along with chemical methods. The O antigen gene cluster of S. boydii type 13 was located and sequenced. Genes for synthesis of UDP-2-acetamido-2,6-dideoxy-L-glucose and genes that encode putative sugar transferases, O unit flippase, and O antigen polymerase were identified. Seven genes were found to be specific to S. boydii type 13. The S. boydii type 13 O antigen gene cluster has higher levels of sequence similarity with Vibrio cholerae gene clusters and may be evolutionarily related to these gene clusters.
Topics: Carbohydrates; Glycosyltransferases; Magnetic Resonance Spectroscopy; Multigene Family; O Antigens; Shigella boydii
PubMed: 14702307
DOI: 10.1128/JB.186.2.383-392.2004 -
Infection and Immunity Nov 2001Shigella strains are in reality clones of Escherichia coli and are believed to have emerged relatively recently (G. M. Pupo, R. Lan, and P. R. Reeves, Proc. Natl. Acad....
Shigella strains are in reality clones of Escherichia coli and are believed to have emerged relatively recently (G. M. Pupo, R. Lan, and P. R. Reeves, Proc. Natl. Acad. Sci. USA 97:10567-10572, 2000). There are 33 O-antigen forms in these Shigella clones, of which 12 are identical to O antigens of other E. coli strains. We sequenced O-antigen gene clusters from Shigella boydii serotypes 4, 5, 6, and 9 and also studied the O53- and O79-antigen gene clusters of E. coli, encoding O antigens identical to those of S. boydii serotype 4 and S. boydii serotype 5, respectively. In both cases the S. boydii and E. coli O-antigen gene clusters have the same genes and organization. The clusters of both S. boydii 6 and S. boydii 9 O antigens have atypical features, with a functional insertion sequence and a wzx gene located in the orientation opposite to that of all other genes in S. boydii serotype 9 and an rmlC gene located away from other rml genes in S. boydii serotype 6. Sequences of O-antigen gene clusters from another three Shigella clones have been published, and two of them also have abnormal structures, with either the entire cluster or one gene being located on a plasmid in Shigella sonnei or Shigella dysenteriae, respectively. It appears that a high proportion of clusters coding for O antigens specific to Shigella clones have atypical features, perhaps indicating recent formation of these gene clusters.
Topics: Bacterial Proteins; Base Sequence; Carbohydrate Dehydrogenases; Carbohydrate Epimerases; Carrier Proteins; DNA, Bacterial; Escherichia coli; Genes, Bacterial; Guanosine Diphosphate Sugars; Hexosyltransferases; Hydro-Lyases; Mannose-6-Phosphate Isomerase; Mannosidases; Membrane Proteins; Molecular Sequence Data; Multienzyme Complexes; Multigene Family; Nucleoside Diphosphate Sugars; Nucleotidyltransferases; O Antigens; Sequence Analysis, DNA; Shigella; Shigella boydii; Thymine Nucleotides; beta-Mannosidase
PubMed: 11598067
DOI: 10.1128/IAI.69.11.6923-6930.2001 -
Tropical Medicine & International... Jan 2001We isolated Shigella from 43/221 (21%) and Salmonella 8/221 (3%) rectal swabs from children under 5 years with diarrhoea, and found Shigella in two of 100 specimens from...
We isolated Shigella from 43/221 (21%) and Salmonella 8/221 (3%) rectal swabs from children under 5 years with diarrhoea, and found Shigella in two of 100 specimens from children without diarrhoea. Sh. boydii (13%) was the most prevalent Shigella species followed by Sh. flexneri (6%) and Sh. sonnei (2%). The prevalence of various types of Sh. boydii was type 7, 5%; type 9, 3%; type 12 and 16, 2%; and type 18, 1%. Other Shigella serotypes encountered were Sh. flexneri type 6 (4%), type 4 (2%), with Sh. sonnei phase II isolated from 2% of the specimens. The Salmonella species were S. typhimurium and S. paratyphi. The high rate of isolation of Shigella species from children with diarrhoea is indicative of a definite role of this enteropathogen in causing endemic diarrhoea in Gaborone, Botswana. Antibiograms of the predominant isolates showed that most Shigella species were resistant to ampicillin but susceptible to chloramphenicol, and with the exception of Sh. flexneri type 6, also susceptible to gentamicin. The Salmonella species were susceptible to chloramphenicol, collistin-sulphate, gentamicin, cotrimoxazole, and ampicillin.
Topics: Anti-Bacterial Agents; Botswana; Child, Preschool; Diarrhea; Female; Humans; Infant; Male; Microbial Sensitivity Tests; Poverty; Salmonella; Serotyping; Shigella; Unemployment
PubMed: 11251896
DOI: 10.1046/j.1365-3156.2001.00668.x -
Gastroenterology and Hepatology From... 2020Determine the prevalence of enteric bacterial pathogens and their antimicrobial resistance among diarrheic children in Nairobi City, Kenya.
AIM
Determine the prevalence of enteric bacterial pathogens and their antimicrobial resistance among diarrheic children in Nairobi City, Kenya.
BACKGROUND
Regardless of enteric bacterial pathogens being a major cause of gastroenteritis in children, their occurrence and antimicrobial resistance patterns reveals regional spatial and temporal variation.
METHODS
In a cross-sectional study, a total of 374 children below five years presenting with diarrhea at Mbagathi County Hospital were recruited. Stool microbiology test was used to detect enteric bacterial infection. Antimicrobial resistance was determined using the disk diffusion method.
RESULTS
Diarrheagenic (36.4%) was the leading species followed by (3.2%), (2.4%), (1.6%), (1.3%) and (1.1%) species. pathotyping revealed that 20.9%, 4.0%, 10.2% and 0.5% of the study participants were infected with enteroaggregative (EAEC), enteropathogenic (EPEC), enterotoxigenic (ETEC) and enteroinvasive (EIEC) pure isolates while the prevalence of mixed pathotype infections was 0.3% for EAEC/EPEC/ETEC and 0.5% for EAEC/ETEC. sero-grouping revealed that 0.5%, 0.3%, 1.9%, and 0.5% were infected with , , and pure isolates. species and co-infection was detected in 2.4% of the children, specifically, 1.1% for EAEC/, 0.5% for EAEC/ and 0.3% in each case of EAEC/, EPEC/ and ETEC/ co-infections. Most of the isolates were resistant to commonly prescribed antibiotics.
CONCLUSION
There was a high prevalence of enteric bacterial pathogens and co-infection alters epidemiological dynamics of bacterial diarrhea in children. Continuous antibiotic resistance surveillance is justified because the pathogens were highly resistant to commonly prescribed antimicrobials.
PubMed: 32821354
DOI: No ID Found -
Mikrobiyoloji Bulteni Oct 2021Increasing resistance to first-line antibiotics used in the treatment of infections caused by Salmonella and Shigella species is emerging. Azithromycin presents a good...
Increasing resistance to first-line antibiotics used in the treatment of infections caused by Salmonella and Shigella species is emerging. Azithromycin presents a good alternative treatment option for Salmonella and Shigella infections. However, there are limited data regarding the susceptibility of azithromycin in Turkey. In this study, we aimed to evaluate the susceptibility of Salmonella and Shigella species to azithromycin, to determine and compare the minimum inhibitory concentration (MIC) values and disk diffusion zone diameters. In addition, susceptibility to meropenem and first-line antibiotic options in isolates was also investigated. A total of 170 Salmonella, 76 Shigella clinical isolates collected between 2014 and 2018 in our hospital were tested for their susceptibility to azithromycin, meropenem, ampicillin, pefloxacin, trimetoprim-sulfamethoxazole, ceftazidime, and cefotaxime. Isolates were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry. The isolates were confirmed and serotyped by the reference laboratory using the conventional slide agglutination method. Susceptibility of the isolates to azithromycin and other antibiotics was evaluated by Kirby-Bauer disk diffusion method. MIC values of azithromycin were determined by the reference broth microdilution method. Combined disk diffusion test was used for the detection of extended spectrum beta-lactamase (ESBL) production. Polymerase chain reaction was performed for macrolide and carbapenem resistance genes and the detected resistance genes were confirmed by sequencing. Of the 76 Shigella isolates tested, 64 (84.2%) were identified as Shigella sonnei, 10 (13.2%) as Shigella flexneri, one (1.3%) as Shigella boydii, and one (1.3%) as Shigella dysenteriae. Among the 170 Salmonella isolates, 131 (77%) were identified as Salmonella enteritidis, 11(6.5%) as Salmonella Typhimurium, 8 (4.7%) as Salmonella Kentucky, 5 (2.9%) as Salmonella Paratyphi B, 4 (2.4%) as Salmonella Infantis, 3 (1.8%) as Salmonella Cholerasuis, and 8 (4.7%) as other serovars (Salmonella Agona, Salmonella Dabou, Salmonella Gallinarum, Salmonella Hadar, Salmonella Muenchen, Salmonella Newport, Salmonella Paratyphi C, Salmonella Senftenberg), respectively. ESBL production was determined as 7.9% (6/76) in Shigella isolates and 2.9% (5/170) in Salmonella isolates. A carbapenem resistant S.Senftenberg isolate positive for the blaOXA-48 resistance gene was detected in our study. Meropenem MIC value of the isolate was detected as > 32 µg/ml with gradient diffusion test. Among all isolates, only one S.boydii isolate was detected as resistant to azithromycin with a MIC value of 128 µg/ml. The isolate was positive for the existence of mphA gene by PCR. In the disk diffusion test, azithromycin inhibition zone diameters were ≥ 12 mm in all of the tested isolates, except for the azithromycin-resistant isolate, and the azithromycin MICs were determined as ≤ 16 µg/ ml by broth microdilution. Increasing resistance to commonly used antibiotics in Salmonella and Shigella species is emerging. The detection of a carbapenem-resistant Salmonella isolate in our study indicates that the spread of carbapenem resistance to other Enterobacterales species may cause global problems. Antimicrobial susceptibility testing of azithromycin for Salmonella and Shigella species has been difficult to establish due to the lack of approval in vitro breakpoints for all species. Consequently, our data shows that azithromycin exhibits as a good alternative therapeutic choice for the treatment of gastrointestinal diseases caused by Salmonella and Shigella species. Further studies are needed to provide appropriate in vitro breakpoints supported by clinical data.
Topics: Anti-Bacterial Agents; Azithromycin; Carbapenems; Drug Resistance, Bacterial; Humans; Microbial Sensitivity Tests; Salmonella; Shigella
PubMed: 34666650
DOI: 10.5578/mb.20219702 -
European Journal of Medical Research Dec 2023Shigella spp., which are facultative anaerobic bacilli within the Enterobacteriaceae family, present a significant public health burden due to their role as prominent...
BACKGROUND
Shigella spp., which are facultative anaerobic bacilli within the Enterobacteriaceae family, present a significant public health burden due to their role as prominent contributors to diarrheal diseases worldwide. A molecular analysis can facilitate the identification and assessment of outbreaks involving this bacterium. So, we aimed to investigate the antibiotic susceptibility pattern and clonal relatedness of clinical Shigella spp. isolates obtained from patients with diarrhea in Hormozgan province, South of Iran.
METHODS
From 2019 to 2021, a cross-sectional investigation was conducted on 448 stool samples obtained from patients who were experiencing diarrhea, in the southern region of Iran. Shigella spp. isolates were identified based on biochemical and serological tests. All Shigella species were verified using species-specific polymerase chain reaction (PCR), followed by susceptibility testing to antimicrobial agents. Subsequently, genotyping of all Shigella species was conducted using ERIC-PCR.
RESULTS
Out of a total of 448 stool samples, the presence of Shigella was detected in 62 cases, accounting for a prevalence rate of 13.84%. Among the identified isolates, the majority were attributed to S. flexneri, representing 53.23% of the cases. This was followed by S. sonnei at 24.19% and S. boydii at 22.58%. Notably, no instances of S. dysenteriae were found. The highest prevalence of Shigella isolates was observed in infants and children under the age of five. A significant proportion of the identified isolates demonstrated resistance to various antibiotics. Specifically, high resistance rates were noted for ampicillin (90.78%), piperacillin-tazobactam (87.1%), cefixime (83.87%), trimethoprim-sulfamethoxazole (83.87%), cefotaxime (82.26%), and ceftriaxone (80.65%). In addition, a substantial number (87.1%) of the isolates exhibited a multidrug-resistant (MDR) phenotype. Using the ERIC-PCR method, a total of 11 clusters and 6 distinct single types were identified among all the Shigella isolates.
CONCLUSION
A notable occurrence of antibiotic-resistant Shigella species has been noted, with multi-drug resistant (MDR) strains presenting an increasing challenge for treating shigellosis worldwide, and this includes Iran. Techniques such as ERIC-PCR are useful for assessing the genetic variation and connections between Shigella strains, which indirectly contributes to understanding antimicrobial resistance patterns. Further research is needed to explore the specific correlation between resistance genes and ERIC genotyping patterns in Shigella strains.
Topics: Child; Infant; Humans; Anti-Bacterial Agents; Iran; Cross-Sectional Studies; Drug Resistance, Bacterial; Shigella; Anti-Infective Agents; Genotype; Diarrhea
PubMed: 38115112
DOI: 10.1186/s40001-023-01570-0 -
Journal of Bacteriology Oct 1984Aerobactin, a hydroxamate iron transport compound, is synthesized by some, but not all, Shigella species. Conjugation and hybridization studies indicated that the genes...
Aerobactin, a hydroxamate iron transport compound, is synthesized by some, but not all, Shigella species. Conjugation and hybridization studies indicated that the genes for the synthesis and transport of aerobactin are linked and are found on the chromosome of Shigella flexneri, S. boydii, and S. sonnei. The genes were not found in S. dysenteriae. A number of aerobactin synthesis mutants and transport mutants have been isolated. The most common mutations are deletions of the biosynthesis or biosynthesis and transport genes. The Shigella aerobactin genes share considerable homology with the E. coli ColV aerobactin genes. On the ColV plasmid and in the Shigella chromosome, the aerobactin genes are associated with a repetitive sequence which has been identified as IS1.
Topics: Base Sequence; DNA Restriction Enzymes; Genes, Bacterial; Hydroxamic Acids; Iron Chelating Agents; Nucleic Acid Hybridization; Plasmids; Repetitive Sequences, Nucleic Acid; Shigella; Species Specificity
PubMed: 6090419
DOI: 10.1128/jb.160.1.266-272.1984