Shigella Boydii Research Articles

Prevalence of Pathogenic Enterobacteria in Market Garden Produce Grown in the Peri-Urban Area of Abidjan, Ivory Coast

This study, which is a contribution to national health surveillance of pathogens, was conducted to determine the prevalence of pathogenic Enterobacteriaceae in the market garden environment of Abidjan. To this end, samples of lettuce, irrigation water, manure and soil were taken from three (03) major market gardening sites in Abidjan. Microbiological analyses of these samples were carried out. The enterobacteria obtained after isolation were identified. The results revealed ten (10) bacterial genera belonging to the Enterobacteriaceae family, including 15 bacterial species in the samples of lettuce, irrigation water, manure and soil analysed. These included Salmonella enterica with serotypes (Salmonella Gallinarum, Salmonella Arizonae, Salmonella Choleraesus), Salmonella spp, Escherichia coli, Shigella boydii, Shigella sonnei, Enterobacter cloacae, Enterobacter aerogenes, Enterobacter gergoviae, Enterobacter agglomerans, Serratia marcesens, Serratia phymutica, Afnia alvei, Citrobacter freuidii Citrobacter diversus, Providencia alcalifasciens, Proteus vulgaris and Yersinia spp. The presence of these pathogenic Enterobacteriaceae indicates a potential risk associated with the consumption of lettuce produced in Abidjan. The Ivorian authorities should take preventive measures, such as educating market gardeners about the harmful effects of contaminated water used to irrigate vegetables, and the use of animal droppings as fertiliser to fertilise the soil, to avoid the future proliferation of infectious diseases such as typhoid fever and bacillary dysentery among the population of Abidjan.

A broadly immunogenic polyvalent Shigella multiepitope fusion antigen protein protects against Shigella sonnei and Shigella flexneri lethal pulmonary challenges in mice.

There are no licensed vaccines for Shigella, a leading cause of children's diarrhea and a common etiology of travelers' diarrhea. To develop a cross-protective Shigella vaccine, in this study, we constructed a polyvalent protein immunogen to present conserved immunodominant epitopes of Shigella invasion plasmid antigens B (IpaB) and D (IpaD), VirG, GuaB, and Shiga toxins on backbone protein IpaD, by applying an epitope- and structure-based multiepitope-fusion-antigen (MEFA) vaccinology platform, examined protein (Shigella MEFA) broad immunogenicity, and evaluated antibody function against Shigella invasion and Shiga toxin cytotoxicity but also protection against Shigella lethal challenge. Mice intramuscularly immunized with Shigella MEFA protein developed IgG responses to IpaB, IpaD, VirG, GuaB, and Shiga toxins 1 and 2; mouse sera significantly reduced invasion of Shigella sonnei, Shigella flexneri serotype 2a, 3a, or 6, Shigella boydii, and Shigella dysenteriae type 1 and neutralized cytotoxicity of Shiga toxins of Shigella and Shiga toxin-producing Escherichia coli in vitro. Moreover, mice intranasally immunized with Shigella MEFA protein (adjuvanted with dmLT) developed antigen-specific serum IgG, lung IgG and IgA, and fecal IgA antibodies, and survived from lethal pulmonary challenge with S. sonnei or S. flexneri serotype 2a, 3a, or 6. In contrast, the control mice died, became unresponsive, or lost 20% of body weight in 48 h. These results indicated that this Shigella MEFA protein is broadly immunogenic, induces broadly functional antibodies, and cross-protects against lethal pulmonary challenges with S. sonnei or S. flexneri serotypes, suggesting a potential application of this polyvalent MEFA protein in Shigella vaccine development.

Laboratory indices of hospitalized sickle cell disease patients, prevalence and antimicrobial susceptibility of pathogenic bacterial isolates at MRCG ward in the Gambia

BackgroundThe aim of this study was to determine the prevalence of invasive bacterial infections and their antimicrobial resistance patterns in sickle cell disease (SCD) patients admitted at the Medical Research Council the Gambia (MRCG) Ward in the era of PCV and Hib vaccination in the Gambia.Methods and ResultsThis study was conducted in the clinical laboratory department of MRCG. We retrospectively generated haematological, and blood culture data from our electronic medical records from 2015 to 2022 of SCD patients admitted to MRCG Ward. Of 380 SCD patients, blood culture was requested only for 159. Of the 159 admitted SCD, 11 patients had qualified positive blood cultures. Five different types of bacterial pathogens were isolated from these positive blood cultures: 4 Staphylococcus aureus, 3 Streptococcus pneumoniae, 2 Salmonella species, 1 Enterococcus species, and 1 Shigella boydii. No episode of bacteremia caused by Haemophilus influenzae type b was identified. The molecular serotyping of the Streptococcus pneumoniae isolates revealed non-vaccine serotypes 10 A, 12 F and 12 F. Penicillin resistance was recorded in two of the three Streptococcus pneumoniae. The Staphylococcus aureus isolates were penicillin resistant but cefoxitin sensitive, hence no methicillin (oxacillin) resistant Staphylococcus aureus was reported. Generally, the isolated pathogens were all sensitive to chloramphenicol, and vancomycin. The haematological indices were not significantly varied between SCD patients with and without microbiologically confirmed bacterial infection.ConclusionStreptococcus pneumoniae and Staphylococcus aureus were the most common cause of bacteremia in these admitted SCD patients. The presence of non-typhoidal Salmonella and Shigella infection coupled with penicillin resistance should be considered during penicillin prophylaxis and empirical treatment regimens for SCD patients and future SCD management policies in the Gambia. The haematological parameters may not be reliable biomarkers in differentiating bacterial from non-bacterial infections in SCD patients.

Green synthesis of silver nanoparticles using extracts of Mikania cordata leaves and evaluation of their antioxidant, antimicrobial and cytotoxic properties

The synthesis of silver nanoparticles using plant extracts is a promising field of research due to the versatile biomedical application of metal nanoparticles. In the present study, silver nanoparticles (AgNPs) were synthesized using the aqueous extract of Mikania cordata leaves where extract act as both reducing and capping agents. Successful biosynthesis of AgNPs had been studied using UV Spectrophotometry that recorded the surface plasmonic resonance peak at around 451 nm. The structural properties and morphology of AgNPs were confirmed by scanning electron microscope with Energy dispersive X-ray (SEM/EDX), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) spectroscopic techniques. In antioxidant assays, AgNPs were found as strong free radical scavenger as ascorbic acid (standard) with the values of 10.06 (EC50, μg/mL) and 20.94 (EC50, μg/mL) for DPPH and ABTS radicals, respectively. In antimicrobial study, the effectiveness of synthesized AgNPs was observed as follows: Shigella boydii > Staphylococcus aureus > Shigella dysenteriae > Escherichia coli. Moreover, the results of cytotoxic assay indicated that AgNPs inhibited the growth of EAC cells in dose-dependent manner. Overall results of this study suggested that the synthesized AgNPs from Mikania cordata leaves have the merits to use in the field of nanomedicines.

Synthesis, Characterization and Antibacterial study of some 1, 3, 4- thiadiazole ring appended azo derivatives

A series of 1,3,4-thiadiazole ring appended azo derivatives were synthesized in good yields via diazo coupling reaction between 5-(4-substituted)-1,3,4-thiadiazole-2-amine and some active methyline compounds such as dimedone and acetylacetone. All the synthesized compounds were characterized by FT-IR and 1HNMR spectroscopic methods. Further, all synthesized compounds were screened for the antibacterial activity against gram negative bacteria (Escherichia coli, Pseudomonas aruginosa, Shigella boydii) and gram-positive bacteria (Staphylococcus aureus, Bacillus megaterium). The thiadiazole ring appended azo derivative containing a chloro group showed potent activity against Shigella boydii (67.85%) and Staphylococcus aureus (78.57%) and the compound having a nitro group in its structure exhibited maximum zone of inhibition against Staphylococcus aureus (89.28%) and Shigella boydii (82.14%).

Probiotic potential of Lactobacillus plantarum DMR14 for preserving and extending shelf life of fruits and fruit juice

The harmful effects of chemical preservatives are driving the need for natural ones. To meet this demand, probiotic lactic acid bacteria (LAB) were isolated from fermented oats in this study. The goals of this study were to separate and identify probiotic LAB from fermented oats, to determine how effective these LAB are at combating pathogenic microorganisms in vitro, and to investigate their preservative capacity by applying the bacterium's cell-free supernatant (CFS) to specific fruits and fruit juice. The isolated strain was identified as Lactobacillus plantarum DMR14 using morphological, biochemical, and molecular investigation. Antimicrobial, antibiofilm, anti-oxidant, pH tolerance, and antibiotic resistance assays were used to evaluate the strain's probiotic potential, showing that Lactobacillus plantarum DMR14 had the strongest antagonistic and anti-biofilm capacity against Shigella boydii. Furthermore, the bacteriocin-containing compounds, cell-free supernatant (CFS) of the LAB, were tested against three fruits and one fruit juice, with the cell-free supernatant (CFS) of the bacterium lengthening the shelf life of the fruits compared to the untreated ones. Furthermore, while the concentration of coliform bacteria decreased in the treated sugarcane juice, an increase in the concentration of lactic acid bacteria suggested that the strain may be used as a fruit preservative in food industries.

A REVIEW OF ANTIBACTERIAL POTENTIAL OF BANANG-BANANG PLANT (Xylocarpus granatum J.Koenig) EXTRACT

Background: Xylocarpus granatum has been used traditionally by coastal communities to treat various diseases. It is known that this plant contains secondary metabolites with various pharmacological activities, including as an antibacterial. Objective: This review article aims to provide information regarding the potential antibacterial activity of banang-banang plants and to summarize the content of compounds that have antibacterial properties and their mechanism of action. Methods: The preparation of this article is through literature studies from various international journals and national journals obtained online by taking into account predetermined inclusion and exclusion criteria. Then it was selected and studied further to obtain data related to the antibacterial activity of banang-banang plants and the content of secondary metabolites that have potential as antibacterials. Results: The banang-banang plant, especially the leaves, roots, fruit, seeds, fruit flesh, fruit peels, stems and bark with its secondary metabolites can inhibit several bacterial species such as Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, Vibrio alginolyticus, Staphylococcus aureus, Shigella boydii , Proteus spp., Streptococcus pyogenes, Ralstonia solanacaerum, Propionibacterium acnes, Agrobacterium tumefaciens, Aspergillus paraciticus, Bacillus subtilis, Candida albicans, Pseudomonas fluorescence, Micrococcus luteus, Saccharomyces ceresiviae, Salmonella typhi, Vibrio alginoliticus and Aeromonas hydrophilla. The secondary metabolites of this plant that have potential as antibacterial are tannins, saponins, steroids, phenols, triterpenoids, flavonoids, alkaloids, terpenoids and glycosides which have their respective mechanisms of action as antibacterial agents. Conclusion: Secondary metabolites contained in each part of the Xylocarpus granatum plant are thought to have a role in its antibacterial activity.Keywords: Antibacterial, Mechanism of action, Secondary metabolite, Xylocarpus granatum J.Koenig.

Insights into Synthesis, Crystal Structure, Bioactivity and Computational Studies of Cu(II) and Zn(II) Carboxylates Containing Aminopyridine

Abstract[Cu2(μ‐2‐chlorobenzoato‐O,O’)4Cl2].2(4‐DMAPH) (1) and [Zn2(μ‐2‐chlorobenzoato‐O,O’)4(4‐DMAP)2] (2) (4‐DMAP=4‐Dimethylaminopyridine) were synthesized from CuCl2/Zn(NO)3)2 . 6H2O, 2‐chlorobenzoic acid and 4‐dimethylaminopyridine in methanol under reflux. Compounds were comprehensively characterized by elemental analyses, conductance measurement, spectroscopic and X‐ray diffraction studies. Complexes crystallized in the monoclinic space group P21/n having dinuclear paddle‐wheel structure. DFT studies along with NCI plot, QTAIM analysis indicate presence of N−H⋯Cl, C−H⋯O, C−H⋯π interactions in 1 and CH3⋯π, π⋯π and C−H⋯Cl in 2. The charge distribution in the complexes was shown via MEP analysis. Complexes interact with CT‐DNA in moderately strong non‐intercalative mode of binding. Antimicrobial study against Shigella flexneri (B), Streptococcus pneumoniae (K), Klebsiella pneumoniae (P) and Shigella boydii (Q) shows appreciable activity of 1 whereas compound 2 is comparatively less active. In vitro cytotoxicity study against cell lines (L‐132) exhibits moderate activity by the complexes, but compound 2 shows significant cell inhibition activity against cell lines K‐562. The complexes are emissive in nature.

Exploring the use of Congo red agar in improving the serotyping of non-serotypeable Shigella with In-silico evidence

ObjectivesTo assess if congo red could make non-serotypeable Shigella strains serotypeable and to employ molecular docking to determine the basis of the same phenomenon. MethodsWe used 42 bacterial strains of non-serotypeable Shigella collected from 2012 to 2019 for this study. Each bacterial strain was freshly inoculated onto congo red agar and incubated at 37° C for 18–24 h. Bacterial colonies obtained were re-subjected to biochemical tests followed by serotyping and serogrouping. In-silico studies to investigate the interaction between MxiC protein of T3SS and O-antigen LPS with congo red were performed. ResultsOf the total 42 non-serotypeable Shigella studied, (26/42)62% were capable of being serotyped following the use of congo red agar, 65% were Shigella flexneri, 19% were Shigella dysenteriae, while 2 strains (7%) each of Shigella boydii and Shigella sonnei were detected. We observed no change in their biochemical properties. The in-silico molecular docking studies revealed high binding affinity between congo red and the B-Chain of Mxi C. Out of the 5 chains of the O-Antigen, congo red showed robust binding with the B-chain with the involvement of a cluster of hydrophobic interactions between them. This may have a crucial role in the conversion of non-serotypeable strains to serotypeable strains on exposure to congo red as observed in our study. ConclusionCongo red agar as a medium converts a sizeable percentage of non-serotypeable Shigella strains to serotypeable Shigella strains.

Shigellain Africa: New Insights From the Vaccine Impact on Diarrhea in Africa (VIDA) Study

We evaluated the burden of Shigella spp from children aged 0-59 months with medically attended moderate-to-severe diarrhea and matched controls at sites in Mali, The Gambia, and Kenya participating in the Vaccine Impact on Diarrhea in Africa (VIDA) study from 2015 to 2018. Shigella spp were identified using coprocultures and serotyping in addition to quantitative polymerase chain reaction (qPCR). Episode-specific attributable fractions (AFe) for Shigella were calculated using Shigella DNA quantity; cases with AFe ≥0.5 were considered to have shigellosis. The prevalence of Shigella was determined to be 359 of 4840 (7.4%) cases and 83 of 6213 (1.3%) controls by culture, and 1641 of 4836 (33.9%) cases and 1084 of 4846 (22.4%) controls by qPCR (cycle threshold <35); shigellosis was higher in The Gambia (30.8%) than in Mali (9.3%) and Kenya (18.7%). Bloody diarrhea attributed to Shigella was more common in 24- to 59-month-old children (50.1%) than 0- to 11-month-old infants (39.5%). The Shigella flexneri serogroup predominated among cases (67.6% of isolates), followed by Shigella sonnei (18.2%), Shigella boydii (11.8%), and Shigella dysenteriae (2.3%). The most frequent S. flexneri serotypes were 2a (40.6%), 1b (18.8%), 6 (17.5%), 3a (9.0%), and 4a (5.1%). Drug-specific resistance among 353 (98.3%) Shigella cases with AMR data was as follows: trimethoprim-sulfamethoxazole (94.9%), ampicillin (48.4%), nalidixic acid (1.7%), ceftriaxone (0.3%), azithromycin (0.3%), and ciprofloxacin (0.0%). A high prevalence of shigellosis continues in sub-Saharan Africa. Strains are highly resistant to commonly used antibiotics while remaining susceptible to ciprofloxacin, ceftriaxone, and azithromycin.

ShigaPass: an in silico tool predicting Shigella serotypes from whole-genome sequencing assemblies.

Shigella is one of the commonest causes of diarrhoea worldwide and a major public health problem. Shigella serotyping is based on a standardized scheme that splits Shigella strains into four serogroups and 60 serotypes on the basis of biochemical tests and O-antigen structures. This conventional serotyping method is laborious, time-consuming, impossible to automate, and requires a high level of expertise. Whole-genome sequencing (WGS) is becoming more affordable and is now used for routine surveillance, opening up possibilities for the development of much-needed accurate rapid typing methods. Here, we describe ShigaPass, a new in silico tool for predicting Shigella serotypes from WGS assemblies on the basis of rfb gene cluster DNA sequences, phage and plasmid-encoded O-antigen modification genes, seven housekeeping genes (EnteroBase's MLST scheme), fliC alleles and clustered regularly interspaced short palindromic repeats (CRISPR) spacers. Using 4879 genomes, including 4716 reference strains and clinical isolates of Shigella characterized with a panel of biochemical tests and serotyped by slide agglutination, we show here that ShigaPass outperforms all existing in silico tools, particularly for the identification of Shigella boydii and Shigella dysenteriae serotypes, with a correct serotype assignment rate of 98.5 % and a sensitivity rate (i.e. ability to make any prediction) of 100 %.

Biogenic Synthesis and Characterization of Silver Nanoparticles: Evaluation of Their Larvicidal, Antibacterial, and Cytotoxic Activities.

To explore the larvicidal activity of the silver nanoparticles (AgNPs) synthesized using the ethanolic Catharanthus roseus flower extract (CRE) against the larvae of Aedes aegypti (A. aegypti), AgNPs were synthesized by an eco-friendly method and characterized by Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), Particle Size Analysis, Transmission Electron Microscopy (TEM), and Energy-Dispersive X-Ray spectrometry (EDX) analysis. The resultant AgNPs showed a spherically well-defined, highly stable, and monodispersed shape with an average particle size ranging from 15 to 25 nm. The absorbance of the AgNPs was measured by using a UV-Vis spectrophotometer at a wavelength of 416 nm. The presence and binding of the phenolic functional group with the AgNPs were confirmed using FTIR analysis. Particle size analysis revealed an average particle diameter of 90 nm with 80 % distribution. XRD analysis revealed the highly crystalline nature of the CRE-AgNPs. The LC50 and LC90 values of CRE-AgNPs and the extract were calculated. The mortality percentage of the extract and synthesized CRE-AgNPs was observed after 24 h. The maximum larvicidal activity with 100 % mortality of A. aegypti was observed in AgNPs synthesized using ethanolic CRE. The LC50 and LC90 values are 8.963 and 20.515 ppm for CRE-AgNPs against A. aegypti larvae, respectively. The CRE-AgNPs revealed superior antibacterial activity against human pathogenic bacteria; the zone of inhibition (ZOI) was measured for all of the pathogens, and the results revealed that different concentrations of CRE-AgNPs showed a remarkable ZOI of about (a) 10-14 mm for Salmonella typhimurium, (b) 6-11 mm for Bacillus subtilis, (c) 11-14 mm for Enterococcus faecalis, and (d) 9-10 mm for Shigella boydii. The maximum ZOI was observed in E. faecalis. Impeccably, the cytotoxicity of CRE-AgNPs at 250 μg/mL is 82% against the HaCaT cell lines. The synthesized CRE-AgNPs showed maximum effectiveness of paradoxical activity on mosquito larvae.

Shigellosis in Southeast Asia: A systematic review and meta-analysis.

Southeast Asia is attractive for tourism. Unfortunately, travelers to this region are at risk of becoming infected with Shigella. We conducted a meta-analysis to provide updates on Shigella prevalence in Southeast Asia, along with their serogroups and serotypes. We conducted a systematic search using PubMed, EMBASE, and Web of Science for peer-reviewed studies from 2000 to November 2022. We selected studies that detected Shigella in stools by culture or polymerase chain reaction (PCR). Two reviewers extracted the data using a standardized form and performed quality assessments using the Joanna Briggs Institute checklist. The random effects model was used to estimate the pooled prevalence of Shigella. During our search, we identified 4376 studies. 29 studies (from six Southeast Asian countries) were included in the systematic review, 21 each in the meta-analysis of the prevalence of Shigella (Sample size: 109545) and the prevalence of Shigella serogroups. The pooled prevalence of Shigella was 4% (95% CI: 4-5%) among diarrhea cases. Shigella sonnei was the most abundant serogroup in Thailand (74%) and Vietnam (57%), whereas Shigella flexneri was dominant in Indonesia (72%) and Cambodia (71%). Shigella dysenteriae and Shigella boydii were uncommon (pooled prevalence of 1% each). The pooled prevalence of Shigella was 5% (95% CI: 4-6%) in children aged <5 years. The pooled prevalence showed a decreasing trend comparing data collected between 2000-2013 (5%; 95% CI: 4-6%) and between 2014-2022 (3%; 95% CI: 2-4%). Shigella prevalence was 6% in studies that included participants with mixed pathogens versus 3% in those without. Shigella flexneri serotype 2a was the most frequently isolated (33%), followed by 3a (21%), 1b (10%), 2b (3%), and 6 (3%). This study provides compelling evidence for the development of effective Shigella vaccines for residents of endemic regions and travellers to these areas.

Qualitative Risk Assessment of Microbial Indicators in the Lower Reaches of Meenachil River, Kerala, India

Pristine natural freshwater resources being severely contaminated by microbiological pollutants is still a big issue in many parts of the world. In the present study, water samples taken from the upstream, midstream, and downstream reaches of the Meenachil River were analysed for the presence of microbial pollution indicators such as faecal coliforms (FC), faecal streptococci (FS), and Eschericia coli. The E. coli isolates were subjected to antimicrobial susceptibility tests and the multiple antibiotic resistance (MAR) indexes were calculated so as to delineate the potential risk posed by infections to humans and animals using the river for routine potable and recreational purposes. E. coli was consistently isolated from all the samples collected from the different zones of the river. Other faecal coliforms such as Klebsiella oxytoca, Citrobacter koseri, Enterobacter, Proteus vulgaricus, and Shigella boydii were also identified. Higher FC/FS ratios were noticed for the midstream and the downstream sites indicating the contamination from high-risk sources such as human and anthropogenic domestic wastes. The MAR index values of E. coli isolates ranged from 0.33 upstream, 0.416 for midstream and 0.583 for the downstream reaches. Given that E. coli is an ideal indicator of faecal pollution, their existence and extended survival of multiple antibiotic resistance natural freshwater pose a potential risk for the consumers. Rapid urbanization and resultant waste drainage in the downstream stretches of the river might have accelerated the deterioration of the water quality up to a certain extent. Furthermore, the riverine system as it flows downstream loses its self-purification capacity due to the loss of natural water drifts. This may be attributed to the periodic shutdown of the salinity barrier, Thanneermukkam Bund in the confluence zone of the river which results in a temporary stagnation of the running waters in the lower stretches.

Anthelmintic, antioxidant, and cytotoxic activities of Chenopodium album against Haemonchus contortus: A combined in vitro and in silico study

Haemonchus contortus is a gastrointestinal nematode that negatively affects the meat and milk production of husbandry animals. The purpose of the study was to determine the anthelmintic activity of Chenopodium album plant extract in controlling H. contortus parasites. The antioxidant, cytotoxic, and antibacterial activities of the C. album plants were also investigated. In an anthelmintic activity test, 100% of H. contortus parasite mortality was observed after 3 h exposure at a dose of 150 μg/mL. The antioxidant properties of C. album showed an IC50 value of 90.98 μg/mL, indicating moderate antioxidant activity when compared to the BHT standard. The cytotoxic effect showed LC50 values of 4.52, 3.11, 2.3, 1.52, and 1.167 μg/mL after 12, 18, 24, 30, and 36 h against Artemia salina, respectively. However, the C. album extract did not demonstrate any antibacterial properties against Bacillus subtilis, Staphylococcus aureus, Salmonella typhi, Shigella dysentriae, Shigella boydii, or E. coli at a concentration of 150 μg/mL. A molecular docking study showed that isolariciresinol 4'-O-beta-D-glucoside, (1S,2S,4R)-1,8-epoxy-p-menthan-2-ol glucoside and linalool (CID-74407576, CID-73815050, and CID-6549) had binding energies of −7.8, −7.5, and −7.1 kcal/mol, respectively, with the Nu-class GST protein. Moreover, the ADMET properties of hit compounds also similarly showed ideal behavior to known drug molecules. Hence, C. album could be a promising candidate for developing an effective drug against H. contortus.

Synthesis, spectroscopic characterization, biological activity, and conducting properties of functionalized Ni(II) dithiocarbamate complexes with solvent extraction studies of the ligands

A series of new nickel(II) dithiocarbamate complexes of general formula [M L2], (where L = benzyl(4-fluorobenzyl)carbamodithioate (L1), benzyl(4-cyanobenzyl)carbamodithioate (L2), ethyl(4-methylbenzyl)carbamodithioate (L3), (4-methoxybenzyl) (naphthalen-1-ylmethyl)carbamodithioate (L4) and ethyl(4-methoxybenzyl)carbamodithioate (L5)) have been synthesized, and characterized via elemental analysis, FT-IR, electronic spectra, 1H NMR, 13C NMR, Mass spectrometry and Thermogravimetric analysis (TGA). The continuous variation method (Job's method) was used to determine the stoichiometry of the complexes. TGA was used to analyze the thermal decomposition behavior of metal complexes in nitrogen atmosphere. As a result of the thermal decomposition process, all of the complexes produced NiS as the final product. X-ray Diffraction (XRD), Energy dispersive X-ray analysis (EDAX), and Transmission electron microscopy (TEM) studies confirm the formation of NiS nanomaterial. Crystalline size of NiS was obtained between 19.97 to 21.35 nm range by applying the Scherrer equation using XRD. Solid-state electrical conductivities reveal that all the complexes behave as a semiconductor at room temperature. All the synthesized dithiocarbamate ligands and complexes were screened against five human bacterial pathogens (Escherichia coli, Staphylococcus aureus, Salmonella typhi, Aeromonas hydrophila, and Shigella boydii) by disc diffusion method. Solvent extraction studies show that the ligand has strong extractability towards metal ions in a basic medium (pH = 10).

Molecular detection and characterization of Shigella spp. harboring extended-spectrum β-lactamase genes in children with diarrhea in northwest Iran.

Shigellosis is one of the acute bowel infections and remains a serious public health problem in resource-poor countries. The present study aimed to survey the distribution of extended-spectrum β-lactamase (ESBL)-producing Shigella strains isolated from patients with diarrhea in northwest Iran. In the present cross-sectional study, from January 2019 to December 2020, 1280 fecal samples were collected from children with diarrhea in Ardabil, Iran. Multiplex PCR assay was applied for the presence of ipaH, invC, wbgZ, rfpB, and rfc genes to detect Shigella spp., Shigella sonnei, Shigella dysenteriae, Shigella flexneri, and Shigella boydii, respectively. Phenotypic detection of ESBL-producing isolates was carried out using the Double Disc Test (DDT). The frequency of main ESBL encoding genes including blaCTX-M, blaSHV, and blaTEM was detected using multiplex PCR. The genetic similarity of S. sonnei isolates was determined using ERIC PCR. A total of 49 Shigella isolates (3.8%; 49/1280) including 42 (85.7%) S. sonnei, 5 (10.2%) S. flexneri, and 2 (4%) S. dysenteriae were identified. S. boydii was not detected in any fecal samples. ESBLs were produced by 10.2% of Shigella spp. including 3 S. sonnei, 1 S. flexneri, and 1 S. dysenteriae. The ESBL encoding genes include blaCTX-M and blaTEM found in 65.3% and 61.2% of isolates, respectively. blaSHV gene was not detected in any isolates. The ERIC-PCR profiles allowed the differentiation of 42 S. sonnei strains into 6 clusters. Our study revealed a high frequency of ESBL-encoding genes among Shigella spp. in northwest Iran. The high prevalence of S. sonnei harboring ESBL genes, in the present work, is the main challenge for dysentery treatment, and this concern justifies the need for effective and regular monitoring of antibiotic usage among patients.

Novel Organotin(IV) Complexes of 2-[4-Hydroxy-3-((2-hydroxyethylimino)methyl)phenylazo]benzoic Acid: Synthesis, Structure, Noncovalent Interactions and In Vitro Antibacterial Activity

Three new organotin(IV) complexes, [Me3Sn(H2L)]2 (1), Bu3Sn(H2L) (2), and [(Bu2Sn(H2L))2O]2 (3) were synthesized by the reaction of 2-[4-hydroxy-3-((2-hydroxyethylimino)methyl)phenylazo]benzoic acid (H3L) with appropriate alkyltin(IV) precursors. The complexes were characterized by elemental analysis, IR, and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. Further, the complex 1 was analyzed by single-crystal X-ray analysis. It displays a 24-membered cyclic dimeric Me3SnIV(H2L) unit where the ligand act as a bridging framework using its carboxylate-O and phenoxy-O atoms. The Sn(IV) adopts distorted trigonal-bipyramidal geometry. In the solution state, the structures were determined by 119Sn-NMR spectroscopy, and the complexes 1 and 2 have distorted tetrahedral geometry, whereas complex 3 shows distorted trigonal-bipyramidal geometry around the tin centres. The Hirshfeld surface analysis and DFT calculations, together with a topological analysis of the electron density distribution in the crystal structure of complex 1, indicate that its molecular packing determined by various noncovalent interactions, including stacking and hydrogen bonding. The antibacterial studies of the ligand and the complexes (1–3) against gram-negative bacteria viz. Klebsiella pneumoniae (A),Vibrio cholerae (M) and Shigella boydii (Q) and gram-positive bacteria viz.Staphylococcus aureus (J), Streptococcus pneumonia (K) are promising and the compounds can be treated as potential common antibacterial materials.

Burden of Shigella in South Asia: a systematic review and meta-analysis.

Shigella remains one of the most common causes of diarrhoea in South Asia. Current estimates of the prevalence of Shigella are critical for guiding control measures. We estimated the prevalence of Shigella species and serogroups in South Asia. We performed a systematic review using PubMed, EMBASE, Google Scholar and Web of Science for peer-reviewed studies published between 2000 and 19 June 2022. We also manually searched the reference lists of the reviewed studies to identify additional studies. We included studies that detected the presence of Shigella in stool by culture or polymerase chain reaction (PCR). Studies associated with outbreaks were excluded. Two investigators independently reviewed the studies, extracted the data and performed quality assessment. A random-effects meta-analysis was performed to determine the pooled prevalence of Shigella. Our search yielded 5707 studies, of which 91 studies from five South Asian countries were included in the systematic review, 79 in the meta-analysis of Shigella prevalence and 63 in the meta-analysis of Shigella serogroups prevalence. The pooled prevalence of Shigella was 7% [95% confidence interval (CI): 6-7%], with heterogeneity (I2= 98.7; P < 0.01). The prevalence of Shigella was higher in children aged <5years (10%; 95% CI: 8-11%), in rural areas (12%; 95% CI: 10-14%) and in studies using PCR (15%; 95% CI: 11-19%). Shigella flexneri (58%) was the most abundant serogroup, followed by Shigella sonnei (19%), Shigella boydii (10%) and Shigella dysenteriae (9%). Shigella flexneri 2a was the most frequently isolated serotype (36%), followed by serotype 3a (12%), serotype 6 (12%) and serotype 1b (6%). The prevalence of non-typeable Shigella was 10.0%. Although the prevalence of Shigella in South Asia remains generally high, it varies by age group and geographical area, with data lacking in some countries. Effective Shigella vaccines would be advantageous for both endemic communities and travellers.

ANTIBACTERIAL AND ANTINOCICEPTIVE ACTIVITY STUDY OF METHANOL EXTRACT OF MIMOSA PUDICA (L.)

The methanol extract of Mimosa pudica was studied for its antibacterial activity against twelve pathogenic bacteria. The extract was also studied for its effect on acetic acid induced writhing model in mice. The extract showed good activity against two gram-positive and six gram-negative bacteria but failed to show any activity against Staphylococcus pyogenes, Salmonella typhi, Shigella boydii and Vibrio cholera. The extract exhibited no antinociceptive activity in acetic acid induced writhing test; rather it increased the abdominal constriction or writhing as compared to the control group which is a sign of pain sensation.