Multidrug-resistant Shigella Species Research Articles

Anti-Shigella and antioxidant-based screening of some Cameroonian medicinal plants, UHPLC-LIT-MS/MS fingerprints, and prediction of pharmacokinetic and drug-likeness properties of identified chemicals.

Ethnopharmacological relevanceShigella infection is a public health problem responsible for approximately 700,000 deaths annually. The management of this disease is impaired by the emergence of multidrug-resistant Shigella species, highlighting the urgent need to search for alternative treatment options. In this regard, investigating medicinal plants traditionally used for the treatment of dysentery, diarrheal infections, and/or associated symptoms in endemic regions might provide an opportunity to identify phytochemicals that could be further used as a basis for the development of future anti-shigella drug candidates. Aim of the studyThis study was designed to investigate the anti-shigella and antioxidant-based ethnopharmacological potency of some Cameroonian medicinal plants with an emphasis on pharmacokinetic properties of the identified chemical pharmacophore. Materials and methodsBriefly, plant species were selected and collected based on their ethnopharmacological uses and information reported in the literature. Crude aqueous, ethanolic, methanolic, and hydroethanolic (30:70, v/v) extracts from these plants were prepared and then screened for their anti-Shigella activity against four Shigella strains and cytotoxicity against Vero and Raw cell lines using microdilution and resazurin-based methods, respectively. The antioxidant activities of potent extracts were evaluated using DPPH, ABTS, NO, and FRAP scavenging assays. The chemical profile of potent extracts was performed using the UHPLC-LIT-MS/MS and the pharmacokinetic properties, druglikeness, and likely molecular targets of the chemical scaffolds identified were predicted using SwissADME and SwissTargetPredictor. ResultsThirty-nine (39) plants belonging to 26 plant families were harvested. Out of the 228 extracts tested, 18 extracts originating from 6 plants (15.38 %) were active (MICs 250–1000 μg/mL) and nontoxic toward Vero (CC50 129.25–684.55 μg/mL) and Raw cell lines (CC50 336.20 to >1000 μg/mL). Six potent extracts from the two plants exhibited moderate to potent DPPH (SC50 8.870–54.410 μg/mL), ABTS (SC50 12.020–27.36 μg/mL), and NO (SC50 0.02–195.85 μg/mL) scavenging activities. Later, these extracts showed interesting ferric iron-reducing power (1.28–12.14 μg equivalent NH2OH/g of extract). The shortest onset of action time (4 and 6 h) observed following inhibition kinetics studies was observed with extracts BFSHE, PMSE, and PMSM. The UHPLC-LIT-MS/MS and some databases (Mass Spectral Library (NIST 14), Human Metabolome Database (HMD), MassBank, SuperNatural 3.0, The Food Database (FooDB), and Chemical Entities of Biological Interest (ChEBI)) allowed the annotation of 18 and 17 metabolites in the extracts from stem bark of P. macrophylla and B. ferruginea respectively. Pharmacokinetic prediction of these chemicals showed that compound 6 (4,6a-bis(Hydroxymethyl)-9a-methyl-3-oxo-1a,1b,3,5,6,6a,7a,9a-octahydrobis (oxireno)[2′,3':5,6; 2″,3'':9,10]cyclodeca[1,2-b]furan-5-yl methacrylate), compound 8 (Corynoxeine), and compounds 35 (Stachybotrydial acetate) demonstrated acceptable druglike and pharmacokinetic properties and might act through inhibition of kinase, transferase, protease, oxidoreductase, and family AG protein-linked receptors. ConclusionThe findings from this investigation demonstrated that Cameroonian medicinal plants are suitable reservoirs of anti-Shigella and antioxidant agents with good drug candidate properties.

Isolation, Genomic Characterization of Shigella prophage fPSFA that effectively infects multi-drug resistant Shigella isolates from the Indian Poultry Sector

Because of uncontrolled use of antibiotics, emergence of multidrug-resistant Shigella species poses a huge potential of zoonotic transfer from poultry sector. With increasing resistance to current antibiotics, there is a critical need to explore antibiotic alternatives. Using a Shigella flexneri reference strain, we isolated a novel fPSFA phage after inducing with mitomycin C. The phage was found to be stable for wide ranges of temperature −20 °C–65 °C and pH 3 to 11. fPSFA shows a latent period that ranges from 20 to 30 min and generation times of 50–60 min. The genome analysis of phage reveals two major contigs of 23788 bp and 23285 bp with 50.16 % and 39.33 % G + C content containing a total of 80 CDS and 2 tRNA genes. The phage belongs to Straboviridae family and lacks any virulence or antimicrobial resistance gene, thus making it a suitable candidate for treatment of drug-resistant infections. To confirm lytic ability of novel phage, we isolated 54 multidrug-resistant Shigella species from thirty-five poultry fecal samples that shows multiple antibiotic resistance index ranging from 0.15 to 0.75 (from 3 Indian states). The fPSFA showed lytic activity against multidrug-resistant Shigella isolates (73.08 %) (MARI≥0.50). The wide host ranges of fPSFA phage demonstrate its potential to be used as a biocontrol agent.

Morphological, biological, and genomic characterization of a newly isolated lytic phage Sfk20 infecting Shigella flexneri, Shigella sonnei, and Shigella dysenteriae1

Shigellosis, caused by Shigella bacterial spp., is one of the leading causes of diarrheal morbidity and mortality. An increasing prevalence of multidrug-resistant Shigella species has revived the importance of bacteriophages as an alternative therapy to antibiotics. In this study, a novel bacteriophage, Sfk20, has been isolated from water bodies of a diarrheal outbreak area in Kolkata (India) with lytic activity against many Shigella spp. Phage Sfk20 showed a latent period of 20 min and a large burst size of 123 pfu per infected cell in a one-step growth analysis. Phage-host interaction and lytic activity confirmed by phage attachment, intracellular phage development, and bacterial cell burst using ultrathin sectioning and TEM analysis. The genomic analysis revealed that the double-stranded DNA genome of Sfk20 contains 164,878 bp with 35.62% G + C content and 241 ORFs. Results suggested phage Sfk20 to include as a member of the T4 myoviridae bacteriophage group. Phage Sfk20 has shown anti-biofilm potential against Shigella species. The results of this study imply that Sfk20 has good possibilities to be used as a biocontrol agent.

Emergence of multidrug-resistant Shigella species harboring extended-spectrum beta-lactamase genes in pediatric patients with diarrhea from southwest of Iran.

Owing to the scarce evidence about the multidrug-resistant (MDR) beta-lactamase-producing Shigella isolates in Iran, this study aimed to evaluate the occurrence of extended-spectrum beta-lactamases (ESBL) and AmpC β-lactamases in Shigella species collected in the southwest of Iran. This study was conducted on Shigella species isolated from stool samples of pediatric patients aged less than 15years suffering from diarrhea. These isolates were identified by bacteriology tests, serotyping, and polymerase chain reaction (PCR). The antibiotic resistance was determined by disc diffusion. The production of ESBLs and AmpC was investigated by phenotypic confirmatory tests and PCR. In total, 79 Shigella isolates, including 46.8% (n = 37) of S. flexneri and 53.2% (n = 42) of S. sonnei, were isolated, respectively. The most effective antibiotic was imipenem with 93.7% of susceptibility followed by ampicillin (29.1%), and cotrimoxazole (30.4%).The resistance rates of ceftriaxone, ceftazidime, and cefotaxime were 41.8%, 34.2%, and 41.8%, respectively. Also, a total of 57 (72.2%) isolates showed MDR profiles. The phenotypic tests showed that 43.0% (34/79) of isolates can produce ESBLs, and no one was positive for ApmC. The frequency of blaTEM and blaCTX-M were 30.4% and 32.9%, respectively, while the blaPER, blaSHV, and AmpC genes were not detected. The ESBL-producing isolates had a significant (p-value˂0.05) resistance rate against ceftriaxone, ceftazidime, cefotaxime, cefepime, erythromycin, and amikacin. The significant prevalence of MDR Shigella isolates harboring ESBL genes highlights the need for effective surveillance measures to prevent the more spread of drug resistance among species.

Potential of Silver Nano Particles Synthesized from <i>Ficus sycomorus</i> <i>Linn</i> Against Multidrug Resistant <i>Shigella species</i> Isolated from Clinical Specimens

Ficus sycomorus Plant was known traditionally for its medicinal properties, Shigella species as a bacterial was also known for their resistance to orthodox medicine. Hence the synthesis of silver nanoparticles from Ficus sycomorus. This study was carried out to investigate the anti-shigellosis potential of silver nanoparticles synthesized from Ficus sycomorus Linn stem bark aqueous extract against Multi-drug Resistant (MDR) Shigella species isolated from clinical specimen collected from patients attending Yobe State Specialist Hospital Damaturu, Nigeria. A total of 400 diarrhoeagenic stools were screened for isolation of Shigella species and determined their antibiotic susceptibility pattern using standard methods. Phytochemical constituents of Ficus sycomorus extract were used to synthesize silver nanoparticles using green synthesis approach. The nanoparticles was analyzed for transmittance, functional groups, sizes and shapes using Uv-vis, FTIR and Scanning Electron Microscopy (SEM), and was tested for antibacterial activities on MDR Shigella isolates. There is no significant difference in Shigella recovery relation to patients gender (P 30 years (21). Shigella were also found to be sensitive to Ciprofloxacin (92%), Augmentin (87%), Cefuroxime (85%), Streptomycin (83.5%) while the most frequent resistance was showcased against Nalidixic Acid (48%), and Tetracycline (27%). Phytochemicals detected include saponins, flavonoids, alkaloids, cardiac glycoside and tannin. Uv-vis showed broad peaks around 460nm, the FTIR showed C-H stretch of hydroxyl group of alkanes and the SEM showed nanoparticles with wide range of shapes and sizes. Anti-Shigella activities of silver nanoparticles is higher at zones of inhibition between 10mm and 30mm higher compared to the activities of crude aqueous extract and AgNO3 solution against the MDR Shigella species which showed an enhanced activities. The high prevalence of shigellosis among children in this study, indicated that improved hygiene is needed for children in the area and detailed examination is required for the treatment of diarrhoea in adults. Ciprofloxacin and Amoxicillin Clavulanate, Nalidixic acid could be used only where culture and sensitivity results prevailed. Enhanced traditional medicine should be given priority because of its potentials. This study have demonstrated feasibility of the green synthesis of F. sycomorus as a potent anti-shigellosis to combat the global burden of the disease. This is the first study On Stem bark aqueous extracts of F. sycomorus against Shigella species in the area.

Genomic and Proteomic Characterizations of Sfin-1, a Novel Lytic Phage Infecting Multidrug-Resistant Shigella spp. and Escherichia coli C.

Shigellosis is a public health threat in developed as well as developing countries like “India.” While antibiotic therapy is the mainstay of treatment for shigellosis, current emergence of multidrug-resistant strains of Shigella spp. has posed the problem more challenging. Lytic bacteriophages which destroy antibiotic resistant Shigella spp. have great potential in this context and hence their identification and detailed characterization is necessary. In this study we presented the isolation and a detailed characterization of a novel bacteriophage Sfin-1, which shows potent lytic activity against multidrug-resistant isolates of Shigella flexneri, Shigella dysenteriae, Shigella sonnei obtained from clinical specimens from shigellosis patients. It is also active against Escherichia coli C. The purified phage is lytic in nature, exhibited absorption within 5–10 min, a latent period of 5–20 min and burst size of ∼28 to ∼146 PFU/cell. The isolated phage shows stability in a broad pH range and survives an hour at 50°C. Genome sequencing and phylogenetic analyses showed that Sfin-1 is a novel bacteriophage, which is very closely related to T1-like phages (89.59% identity with Escherichia virus T1). In silico analysis indicates that Sfin-1 genome consists of double stranded linear DNA of 50,403 bp (GC content of 45.2%) encoding 82 potential coding sequences, several potential promoters and transcriptional terminators. Under electron microscopy, Sfin-1 shows morphology characteristics of the family Siphoviridae with an isometric head (61 nm) and a non-contractile tail (155 nm). This is most likely the first report of a lytic bacteriophage that is active against three of the most virulent multidrug-resistant Shigella species and therefore might have a potential role in phage therapy of patients infected with these organisms.

Prevalence and molecular characterization of multidrug-resistant Shigella species of food origins and their inactivation by specific lytic bacteriophages

Shigella spp. can be isolated from various food sources and is responsible for many outbreaks and sporadic cases of foodborne diseases worldwide. Although Shigella species are known as one of the major foodborne pathogens, a few studies have characterized the prevalence and molecular basis of antibiotic resistance of Shigella spp. isolated from food origins. This study investigated the prevalence of Shigella spp. in a wide range of food samples (1400 samples), and the phenotypic and genotypic basis of antimicrobial resistance of the isolates. In addition, the potential of two Shigella specific phages (vB_SflS-ISF001 and vB_SsoS-ISF002) to control the growth of the isolates in food was tested. Shigella sonnei and Shigella flexneri were detected in 11 (0.8%) and 8 (0.6%) samples, respectively. The highest prevalence of Shigella spp. was observed in vegetables. Multidrug resistance phenotypes were noticeably frequent and observed in 17 isolates (89.5%) out of 19 isolates. Moreover, 13 (68.4%), 9 (47.4%) and 17 (89.5%) isolates were positive for β-lactamase-encoding, plasmid-mediated quinolone resistance and tetracycline resistance genes, respectively. Treatment with the phages reduced bacterial counts up to 3 and 4 log when used individually or in cocktail form, respectively. The findings of this study indicate the prevalence of Shigella spp. in food sources and also provide useful information for a better understanding of the molecular aspects of antimicrobial resistance in Shigella spp.. The results also suggest that the combination of vB_SflS-ISF001 and vB_SsoS-ISF002 phages can effectively reduce contamination of two important species of Shigella in food.

Genotypic Diversity of Multidrug Resistant Shigella species from Iran.

BackgroundIn many developing countries, shigellosis is endemic and also occurs in epidemics and treatment of multidrug-resistant (MDR) isolates are important. The aims of this study were to determine the antimicrobial susceptibility, prevalence of class 1 and 2 integrons and the clonal relatedness of isolates.Materials and MethodsAntimicrobial susceptibility tests were performed by disc diffusion method. Polymerase chain reaction (PCR)-sequencing technique was employed for detection and characterization of integrons. The genetic relatedness was evaluated by using enterobacterial repetitive intergenic consensus (ERIC) PCR.ResultsThere was a high percentage of resistance to trimethoprim-sulfamethoxazole (TMP/SMX) (93.7%), ampicillin (AMP) (87.3%), streptomycin (STR) (84.5%) and tetracycline (TET) (78.9%). Multidrug resistant phenotype was seen in 95.1% of total isolates. Most common MDR profile was TMP/SMX/STR/AMP resistant pattern. Among the 142 Shigella spp. analyzed in this study, 28 isolates were positive for class 1 integron with two types of gene cassette arrays (dfrA17/aadA5 = 31.7% and dfrA7 = 3.8%). The class 2 integron was more frequently detected among the isolates (94.7%) with dfrA1/sat1/aadA1 (69.4%) and dfrA1/sat1 (30.6%) gene cassettes. ERIC-PCR results showed 6, 5, 4 and 3 main genotypes among S. flexneri, S. sonnei, S. boydii and S. dysenteriae isolates, respectively.ConclusionsOur findings revealed that multidrug resistant Shigella species with high prevalence of class 2 integron were very common in Iran. In addition, ERIC-PCR patterns showed limited variety of clones are responsible for shigellosis in the region of the study.

Molecular Evaluation of High Fluoroquinolone Resistant Genes in Endemic Cases of Shigellosis, Northeast Part of Karnataka, India

ObjectivesShigellosis is an acute infection of the intestine caused by bacteria in the genus Shigella and also an important cause of diarrhea in developing countries. This study was carried out to find the extent and nature of the emerging resistance in north part of Karnataka, India, and surrounding region with huge population, and also focused on the molecular mechanism of development of resistance against different generations of fluoroquinolones and explored the diversity of restriction endonucleases; we also tried to establish the significance of reduced minimal inhibitory concentrations (MIC) values. MethodsA total of 32 multidrug-resistant Shigella species (isolated from infants’ stools) were subjected to MICs of fluoroquinolone-resistant isolates done by both broth dilution and E-test method. The genes implicated in resistance to fluoroquinolone generations ciprofloxacin, ofloxacin, and gatifloxacin (gyrA, gyrB, parC, and parE) were amplified using polymerase chain reaction (PCR) method and restriction digestion analysis of PCR product were performed using PvuI and HaeII enzymes. FindingsFluoroquinolone-resistant Shigella species (n = 32) comprising S dysenteriae, S flexneri, and S sonnei were selected for MIC; 90.6% (29/32), 93.75% (30/32), and 93.75% (30/32) of isolates were ciprofloxacin, ofloxacin, and gatifloxacin resistant and showed the MIC range from 4-128 μg/mL. The PCR amplification results were positive for all species and asserted the presence of gyrA, gyrB, parC, and pare and sizes of the amplified products. The restriction banding patterns of amplified resistant genes were employed to detect differences among the Shigella species. ConclusionsThe present study found that the genetic basis and its characterization of fluoroquinolone resistance in Shigella isolates was considered for the common resistant genes, namely, gyrA, gyrB, parC, and pare, and had mutations at position 83 of gyrA and at position 80 of parC of the quinolone-resistant determining regions and associated molecular mechanism. Our study beneficial in identification of the causative agents of the infections, careful control and cautions use of antibiotics must be promoted, particularly to monitor the emergence of isolates that are fully resistant to fluoroquinolones.

Choke Point Analysis with Subtractive Proteomic Approach for Insilico Identification of Potential Drug Targets in Shigella Dysenteriae

Shigellosis is an endemic disease prevalent in developing and poor countries due to fecal-oral transmission resulting a significant morbidity and mortality rate. Emergence of multidrug resistant (MDR) in Shigella sp. reveals the inefficacy towards the first line antibiotics like quinolones, cotrimoxazole and ampicillin against it. There is continuous need to monitor the characteristics and antibiotic resistance patterns of this pathogen regarding the identification of new potential therapeutic drug targets. Availability of complete protein of different Shigella species viz flexneri, body, dysentery and son has made it possible to carry out the Insilico analysis of its protein for the identification of potential vaccine and drug targets. Subtractive proteomics approach is being used to mine the list of proteins present in different Shigella species which are non-homologous to human and essential for the survival of the pathogen. The metabolic chokepoint analysis also enriches the list of essential protein and adds those proteins in the list which are uniquely found in pathogenic pathway, catalyzed by single enzyme and involved in multi pathways. Screening of essential proteins against human gut flora and approved drug targets revealed the targets which are non-homologous to human gut flora and homologous to the approved drug targets. Broad spectrum drug targets screening revealed a list of highly conserved proteins of various pathogens including different Shigella species. Probably the drug developed against these targets may be useful in treating multiple diseases or diseases which results due to co-infection of different pathogens. Subcellular localization prediction revealed a list protein, which could be potential vaccine targets in different Shigella species. Virtual screening against these identified targets might be useful in the discovery of novel Drug against MDR Shigella species.

Molecular characterization of multidrug-resistant Shigella species isolated from epidemic and endemic cases of shigellosis in India

Shigella species represent one of the growing numbers of antimicrobial-resistant bacteria in developing countries. Fluoroquinolone-resistant strains of Shigella dysenteriae type 1 and Shigella flexneri type 2a emerged in India during 2002 and 2003, respectively. Sixty strains of Shigella from different parts of India were analysed for antimicrobial susceptibility, the presence of the qnr plasmid, mutations in the quinolone resistance determining regions (QRDRs), fluoroquinolone accumulation, and the presence of other genes encoding resistance to various antimicrobials. Fluoroquinolone-resistant strains had mutations in gyrA and parC genes and had an active efflux system. They were also resistant to several other antimicrobials but were susceptible to azithromycin and ceftriaxone. The majority of the strains harboured genes encoding resistance to ampicillin (97 %), tetracycline (95 %), streptomycin (95 %) and chloramphenicol (94 %). PFGE analysis revealed clonality among strains of S. dysenteriae types 1 and 5, S. flexneri type 2a and Shigella boydii type 12.

Shigellocidal properties of three Nigerian medicinal plants: Ocimum gratissimum, Terminalia avicennoides, and Momordica balsamina.

The prevalence of multidrug-resistant shigellae is an important concern in the treatment of shigellosis in many developing countries, and other therapies, including herbal agents, may provide an important alternative to antimicrobial agents. In this study, three Nigerian medicinal plants: Ocimum gratissimum, Terminalia avicennoides, and Momordica balsamina were investigated for their activities against multidrug-resistant Shigella species isolated from patients with bacilliary dysentery in Lagos. Decoctions of O. gratissimum and concoctions of O. gratissimum and T. avicennoides at crude concentration of 3,000 micrograms/mL markedly inhibited the growth of all isolates tested. Zones of inhibition indicating susceptibilities of the organisms varied from 18.3 to 21.5 mm for Shigella dysenteriae, 15.3 to 16.3 mm for S. flexneri, 18.8 to 19.3 mm for S. sonnei, and 16.5 mm for S. boydii. Except S. flexneri, minimum inhibitory concentration and minimum bactericidal concentration revealed a higher shigellocidal property of O. gratissimum/T. avicennoides concoction than other extracts in S. dysenteriae (300-515.6 vs 337.5-1,312.5 micrograms/mL), S. sonnei (309.4-543.8 vs 403.1-1,312.5 micrograms/mL), and S. boydii (243.8-337.5 vs 253-1,312.5 micrograms/mL). O. gratissimum showed a greater shigellocidal effect against the S. flexneri isolates, while extracts of M. balsamina possessed low shigellocidal potential. The results suggest that aqueous extracts of O. gratissimum and T. avicennoides as decoctions and concoctions could be useful in the treatment of shigellosis and should be clinically evaluated specially in Nigerian region.

Etiology of Bloody Diarrhea in Bolivian Children: Implications for Empiric Therapy

In Bolivia, few data are available to guide empiric therapy for bloody diarrhea. A study was conducted between December 1994 and April 1995 to identify organisms causing bloody diarrhea in Bolivian children. Rectal swabs from children <5 years old with bloody diarrhea were examined for Salmonella, Shigella, and Campylobacter organisms; fecal specimens were examined for Entamoeba histolytica. A bacterial pathogen was identified in specimens from 55 patients (41%). Shigella organisms were found in 39 specimens (29%); 37 isolates (95%) were resistant to ampicillin, 35 (90%) to trimethoprim-sulfamethoxazole, and 24 (62%) to chloramphenicol, but all were susceptible to nalidixic acid. Only 1 of 133 stool specimens contained E. histolytica trophozoites. Multidrug-resistant Shigella species are a frequent cause of bloody diarrhea in Bolivian children; E. histolytica is uncommon. Clinical predictors described in this study may help identify patients most likely to have Shigella infection. Laboratory surveillance is essential to monitor antimicrobial resistance and guide empiric treatment.