Influence of Different Physico-Chemical Stresses on Growth and Survivality of Shigella dysenteriae and Shigella flexneri

2001 ◽  
Vol 2 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Ishrat Sultana . ◽  
Rahman Md. Mizanur . ◽  
Shakhawat Hossain Bh . ◽  
Md. Majibur Rahman .
Keyword(s):  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Physico Chemical

Molecular Strategies for the Detection, Identification, and Differentiation between Enteroinvasive Escherichia coli and Shigella spp.

2005 ◽  
Vol 68 (2) ◽  
pp. 239-245 ◽  
Author(s):  
CESAR I. BIN KINGOMBE ◽  
MARIA-LUCIA CERQUEIRA-CAMPOS ◽  
JEFFREY M. FARBER
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Shigella Boydii ◽  
Epidemiological Tool ◽  
Pcr Rflp ◽  
Shigella Spp

A strategy for the detection, identification, and differentiation of enteroinvasive Escherichia coli (EIEC) and Shigella spp. has been developed. The strategy includes (i) a multiplex PCR for the amplification of two virulence genes, i.e., iuc (222 bp) and ipaH (629 bp); (ii) amplification of the ial gene (a 1,038-bp amplicon) located within a large plasmid; and (iii) restriction fragment length polymorphism (RFLP) of the ial gene amplicon. The multiplex PCR provided three patterns. Pattern 1 (iuc−/ipaH+) was found in 10 (67%) of 15 EIEC strains tested, pattern 2 (iuc+/ipaH−) in only 2 (4.4%) of 46 non-EIEC isolates, whereas pattern 3 (iuc+/ipaH+) was observed in all Shigella spp. and also in 5 (33%) of 15 EIEC strains tested. The pattern 3 EIEC strains were all positive for the ial gene. The PCR-RFLP of the ial gene amplicon using the endonuclease AclI was used to differentiate Shigella spp. from the EIEC strains that belonged to pattern 3. The ial gene was present in 21 (38%) of 56 and 6 (40%) of 15 Shigella spp. and EIEC strains tested, respectively. The PCR-RFLP of the ial gene amplicon divided the strains in two types. Type 1 did not contain the restriction enzyme site and was found in 6 (100%) of 6 EIEC strains, 4 (80%) of 5 Shigella boydii, and 4 (100%) of 4 Shigella dysenteriae strains tested. Type 2, which gave two fragments of 286 and 752 bp, was observed in 5 (83%) of 6 Shigella flexneri strains and 6 (100%) of 6 Shigella sonnei strains. Detection, identification, and differentiation of Shigella spp. and EIEC were achieved by analyses of the PCR patterns and RFLP types. To our knowledge, this is the first study to demonstrate a simple and rapid method for detecting, identifying, and differentiating, at the molecular level, Shigella spp. and EIEC strains. This method will have tremendous utility as an epidemiological tool and in helping to develop policies, risk assessments, and national and international methods for Shigella spp.

scholarly journals Antibacterial, antifungal and insecticidal activities of Ruellia tuberosa (L.) root extract

2014 ◽  
Vol 20 ◽  
pp. 91-97 ◽  
Author(s):  
Md Abdul Kader ◽  
Shumaia Parvin ◽  
Md Aktar Uzzaman Chowduri ◽  
Md Ekramul Haque
Keyword(s):  
Tribolium Castaneum ◽  
Insecticidal Activity ◽  
Antifungal Agents ◽  
Surface Film ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
Assay Method ◽  
Root Extract ◽  
Film Activity ◽  
Insecticidal Activities

Context: Plants as therapeutics are popularized for thousands of years and people continue to rely on them for health care until now due to their effectiveness, easy availability, low cost and comparatively being devoid of serious toxic effects. Microorganisms such as bacteria, fungi and insects are developing resistance to the current therapies very easily and the currently available antibacterial, antifungal agents and pesticides are very much costly and toxic. So the current shift to the use of herbal antibacterial, antifungal agents and pesticides may be more effective, economic and advantageous. Objectives: The present research was performed to investigate the antibacterial, antifungal and insecticidal activities of the methanolic extract of the dried root of the plant Ruellia tuberosa (L.). Materials and Methods: Five Gram (+) ve bacteria namely Staphylococcus aureus, Staphylococcus agalactiae, Bacillus cereus, Bacillus megaterium, Bacillus subtilis; five Gram (-) ve bacteria namely Pseudomonus aeruginosa, Escherichia coli, Shigella flexneri, Shigella dysenteriae, Shigella sonnei were used as test bacteria for testing the antibacterial activity of the plant extract. Antifungal activity was observed against six fungi namely Candida albicans, Aspergillus niger, Aspergillus ochreus, Aspergillus ustus, Rizopus oryzae and Trichophyton rubrum. The disc diffusion assay method was used in both the cases and standard Kanamycin disc (30?g/disc) was used as the reference standard. The test for insecticidal activity was performed by using surface film activity testing method and Tribolium castaneum (Herbst) was used as the test insect. Results: The methanol extract was active against all the bacteria and fungi tested and showed significant antibacterial and antifungal properties with the zone of inhibition 9 to 23 mm for antibacterial screening and 8 to 15 mm for antifungal screening. The insecticidal assay by surface film activity test also revealed strong insecticidal activity with 80% mortality rate of Tribolium castaneum (Herbst) at a dose of 50 mg/ml in 48 hours. Conclusion: From our experiment it is informed that Ruellia tuberosa (L.) may be used to treat bacterial and fungal diseases and also as insect repellant and it is also possible to isolate antibacterial, antifungal and insecticidal drug from this plant. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17720 J. bio-sci.  20:  91-97, 2012

scholarly journals Molecular characterization of serologically atypical provisional serovars of Shigella isolates from Kolkata, India

2014 ◽  
Vol 63 (12) ◽  
pp. 1696-1703 ◽  
Author(s):  
Shanta Dutta ◽  
Priyanka Jain ◽  
Suman Nandy ◽  
Shigeru Matsushita ◽  
Shin-ichi Yoshida
Keyword(s):  
Molecular Characterization ◽  
Virulence Genes ◽  
Shigella Flexneri ◽  
Acute Diarrhoea ◽  
Tetracycline Resistance ◽  
Shigella Dysenteriae ◽  
Single Mutation ◽  
Chloramphenicol Resistance ◽  
Resistant Strains

During 2000–2004, 13 Shigella strains that were untypable by commercially available antisera were isolated from children <5 years of age with acute diarrhoea in Kolkata. These strains were subsequently identified as Shigella dysenteriae provisional serovar 204/96 (n = 3), Shigella dysenteriae provisional serovar E23507 (n = 1), Shigella dysenteriae provisional serovar I9809-73 (n = 1), Shigella dysenteriae provisional serovar 93-119 (n = 1), Shigella flexneri provisional serovar 88-893 (n = 6) and Shigella boydii provisional serovar E16553 (n = 1). In this study, characterization of those provisional serovars of Shigella was performed with respect to their antimicrobial resistance, plasmids, virulence genes and PFGE profiles. The drug resistant strains (n = 10) of Shigella identified in this study possessed various antibiotic resistance genetic markers like catA (for chloramphenicol resistance); tetA and tetB (for tetracycline resistance); dfrA1 and sul2 (for co-trimoxazole resistance); aadA1, strA and strB (for streptomycin resistance) and blaOXA-1 (for ampicillin resistance). Class 1 and/or class 2 integrons were present in eight resistant strains. Three study strains were pan-susceptible. A single mutation in the gyrA gene (serine to leucine at codon 83) was present in four quinolone resistant strains. The virulence gene ipaH (invasion plasmid antigen H) was uniformly present in all strains in this study, but the stx (Shiga toxin) and set1 (Shigella enterotoxin 1) genes were absent. Other virulence genes like ial (invasion associated locus) and sen (Shigella enterotoxin 2) were occasionally present. A large plasmid of 212 kb and of incompatibility type IncFIIA was present in the majority of the strains (n = 10) and diversity was noticed in the smaller plasmid profiles of these strains even within the same provisional serovars. PFGE profile analysis showed the presence of multiple unrelated clones among the isolates of provisional Shigella serovars. To the best of our knowledge, this is the first report on the phenotypic and molecular characterization of provisional serovars of Shigella isolates from Kolkata, India.

scholarly journals Molecular detection of all 34 distinct O-antigen forms of Shigella

2009 ◽  
Vol 58 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Yayue Li ◽  
Boyang Cao ◽  
Bin Liu ◽  
Dan Liu ◽  
Qili Gao ◽  
...  
Keyword(s):  
Shigella Flexneri ◽  
Bacterial Species ◽  
Milk Powder ◽  
Shigella Dysenteriae ◽  
Detection Sensitivity ◽  
Clinical Samples ◽  
Shigella Boydii ◽  
O Antigen ◽  
Probe Concentration ◽  
O Antigens

Shigella is the cause of shigellosis or bacillary dysentery, the occurrence of which is estimated to be 165 million cases per year worldwide, resulting in 1.1 million deaths. Rapid and reliable assays for detecting and identifying Shigella in food, environmental and clinical samples are therefore necessary. Shigella species are traditionally identified by their O antigens. This study developed a DNA microarray targeting O-serotype-specific genes to detect all 34 distinct O-antigen forms of Shigella, including Shigella boydii types 1–18, Shigella dysenteriae types 1–13, Shigella flexneri types 1–5 and 6, and Shigella sonnei. A total of 282 strains were used to test the specificity of the microarray, including 186 Shigella and Escherichia coli representative strains, 86 Shigella clinical isolates and ten strains of other bacterial species that are commonly isolated from food or clinical stool specimens. The oligonucleotide probes were printed on the microarray in concentrations from 1 to 100 μM, and 10 μM proved to be the optimal probe concentration. The detection sensitivity for each serotype was 50 ng genomic DNA or 1 c.f.u. in 25 g milk powder sample following a 6 h enrichment in broth. The microarray is specific, sensitive and reproducible, and, to our knowledge, is the first report of a microarray for serotyping all O-antigen forms of Shigella.

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