Bacterial Dysentery Research Articles

ANTIBACTERIAL ACTIVITY OF ETHANOL CRUDE EXTRACTS OF WHOLE PLANT OF THE UGANDAN PHYLLANTHUS AMARUS SCHUMACH. & THONN AGAINST SHIGELLA DYSENTERIAE

Apart from being used for the treatment of malaria fevers, mono-herbal preparation of Ugandan Phyllanthus amarus is widely by local communities in central Uganda, for treatment of bacterial dysentery. However, efficacy studies regarding the mono-herbal extracts of the Ugandan Phyllanthus amarus against Shigella dysenteriae is lacking. The present study was aimed at determined the antibacterial activity of aqueous ethanol crude extracts of whole plant of Phyllanthus amarus against Shigella dysenteriae. Whole plant of Phyllanthus amarus was collected from Wakiso district central of Uganda. Different concentrations (128µg/ml, 256µg/mL-1 and 512µg/ mL-1) of the ethanol crude extract of whole plant of Phyllanthus amarus were tested against Shigella dysenteriae using agar well diffusion method. Minimum inhibitory concentration (MIC) was determined using broth tube dilution method while Minimum bactericidal concentration (MBC) was determined by culture method. The results of this study showed that, Shigella dysenteriae was sensitive to different concentrations (128µg/ mL-1, 256µg/ mL-1and 512µg/ mL-1) of ethanol crude extract of whole plant of Phyllanthus amarus possessed antibacterial against Shigella dysenteriae with mean and standard error mean zone of inhibition ranging from 11.5±0.5 to 13.5±0.5mm, while the positive control had mean and standard error mean zone of inhibition 24.5±0.5mm. The MIC and MBC of the ethanol crude extract of whole plant of Phyllanthus amarus against Shigella dysenteriae was found to be 32µg/ml and 64µg/ml respectively. This study found that the whole plant of phyllanthus amarus of ethanol crude extract was active against Shigella dysenterie. Further study should be carried out test whole plant Phyllanthus amarus crude extract on different microorganisms that cause dysentery to find out its activity against them and spectrum, determine lead compound in the whole plant Phyllanthus amarus crude extract responsible for the anti-microbial activity against Shigella dysenteriae and also determine the mechanism of action by which this plant crude extract inhibits Shigella dysenteriae.

重庆市 2009—2016年细菌性痢疾空间流行病学特征及基于气象要素的预测模型研究

重庆市 2009—2016年细菌性痢疾空间流行病学特征及基于气象要素的预测模型研究

Fingerprint Analysis and Quantitative Determination of Fourteen Active Components in the Traditional Chinese Medicinal Preparation Feiyangchangweiyan Capsule by HPLC-DAD-ESI-MS/MS.

FeiYangchangweiyan capsule (FY capsule), a traditional Chinese medicinal preparation consisting of three medicinal herbs, has been used to treat bacterial dysentery, acute, and chronic gastroenteritis for several decades. In this study, a novel, convenient, accurate, and valid method was developed by using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD) to obtain a chromatographic fingerprint of FeiYangchangweiyan capsule (FY capsule). Then, fourteen peaks were identified according to MS/MS fragmentation behavior of the reference standards by using HPLC-DAD-ESI-MS/MS analysis. At the same time, the fingerprint similarity was calculated and the contents of known ingredients were also determined simultaneously. The result demonstrated that the HPLC fingerprint combining similarity evaluation and quantification analysis can be successfully applied to control the quality of FY capsule.

AGE FEATURES OF INTESTINAL AMOEBIASIS

Study objective. To establish clinical and epidemiological features of intestinal amebiasis in adults and children at the present stage. A retrospective analysis of patient histories of 90 cases of intestinal amebiasisin patients aged 3 to 40 years who were on inpatient treatment in Regional Infectious Clinical Hospital named after A.M Nichogi, Astrakhan, in the period from 2014 to 2017. The diagnosis of amebiasis was confirmed by microscopy of feces, detection of antibodies by using reaction of indirect hemagglutination (RHAG) with a specific antigen, determination of DNA of the parasite by polymerase chain reaction (PCR).Results. It was determined that the incidence of intestinal amebiasis in the Astrakhan region is sporadic with the involvement in the epidemic process of persons of working age from 18 to 40 years (75.6%) and children aged 3 to 10 years (24.6%) of organized groups living in the city. Acute intestinal amebiasis in 86.8% of adults proceeded in mild to moderate form. The clinical course of the disease was characterized by a gradual onset in 82.4%, mucosal-bloody stool in 94.1%, the outcome of a chronic recurrent form in 11.8%. Raspberry jelly-like stool, extraintestinal complications of amebiasis, characteristic of amebiasis of previous years, were absent.The features of intestinal amebiasis in children were: acute onset of the disease in 63.6%, fever 38°C and above in 54.5%, abdominal pain in 95.5%, prolonged diarrhoea with a stool frequency of more than 10 times in 72.7%, stool with blood mucus in 95.5%, tenesmus in 36.4%, dehydration in 18.6% of patients. The mild form of the disease in children was not observed, severe was observed in 54.5%, moderate in 45.5%. The combined course of intestinal amebiasis with bacterial dysentery, proceeded more severely, changed clinical symptoms of the disease, made it difficult to diagnose amebiasis in a timely manner.

Association between distribution of bacillary dysentery and meteorological factors in Beijing, 2004-2015

Objective: To analyze the distribution characteristics of bacillary dysentery in Beijing during 2004-2015 and evaluate the influence of meteorological factors on the temporal and spatial distribution of bacillary dysentery. Methods: The incidence data of bacterial dysentery and meteorological data in Beijing from 2004 to 2015 were collected. Descriptive epidemiological analysis was conducted to study the distribution characteristics of bacterial dysentery. Linear correlation analysis and multiple linear regression analysis were carried out to investigate the relationship between the incidence of bacillary dysentery and average precipitation, average air temperature, sunshine hours, average wind speed, average air pressure, gale and rain days. Results: A total of 280 704 cases of bacterial dysentery, including 36 deaths, were reported from 2004 to 2015 in Beijing, the average annual incidence was 130.15/100 000. The annual incidence peak was mainly between May and October, the cases occurred during this period accounted for 80.75% of the total, and the incidence was highest in age group 0 year. The population distribution showed that most cases were children outside child care settings and students, and the sex ratio of the cases was 1.22∶1. The reported incidence of bacillary dysentery was positively associated with average precipitation, average air temperature and rain days with the correlation coefficients of 0.931, 0.878 and 0.888, but it was negatively associated with the average pressure, the correlation coefficient was -0.820. Multiple linear regression equation for fitting analysis of bacillary dysentery and meteorological factors was Y=3.792+0.162X(1). Conclusion: The reported incidence of bacillary dysentery in Beijing was much higher than national level. The annual incidence peak was during July to August, and the average precipitation was an important meteorological factor influencing the incidence of bacillary dysentery.

Characterization of s1289 in Biofilm Formation and Infection in S. flexneri

Shigella flexneri is an intracellular pathogen that invades colonic epithelial cells and causes bacterial dysentery, which accounts for approximately 165 million cases worldwide and 1 million associated deaths, annually. Shigella infections are predominant in third world countries with poor access to hygiene resources. It can be spread via person to person contact or by contaminated food or water. What is known about Shigella pathogenesis is that it can withstand the acidic environments of the digestive tract, evade immune responses, invade intestinal epithelium using a Type 3 Secretion System (T3SS) and acquire actin‐based motility by manipulating the host cell actin cytoskeleton. Another characteristic of the pathogen is its ability to disseminate between epithelial cells via the formation of plasma membrane protrusions that resolve into vacuole like protrusions (VLP's) and finally collapse and form a vacuole in the adjacent intestinal cell. Although much is known about how the pathogen invades and spreads into neighboring intestinal cells using the T3SS, there is not enough information on how Shigella transit through the intestinal tract and what events occur prior to infection of colonic cells. We decided to focus on the possibility of other extracellular components in the bacterium that could contribute to virulence. The gene s1289 in Shigella chromosomal DNA encodes for an outer membrane autotransporter protein that can possibly be linked with adhesion to host cells and may contribute to invasion. Recent research has shown that the presence of bile salts induces biofilm formation of S. flexneri. Formation of biofilm is an important determinant for increased adherence and virulence in E. coli strains, but has not been thoroughly investigated in S. flexneri. We decided to test the role of gene s1289 in the formation of S. flexneri biofilms and in adherence to intestinal cells. Our hypothesis was that if we were able to delete the gene s1289 from the bacterial genome, the new mutant strain would lose its capacity to form biofilms and to adhere to colonic epithelial cells. We created a construct displaying a disrupted version of s1289 in E. coli and introduced it in S. flexneri by conjugation. After allelic exchange by homologous recombination, we identified mutant strains displaying the disrupted version of s1289 in their genome. We determined biofilm thickness using confocal microscopy, tested for susceptibility of biofilm using antimicrobial agents, and investigated the ability of the mutant to infect HT‐29 intestinal cells. Although the Δs1289 mutant did form biofilm in presence of 0.4% bile salts, results showed that the structure of the biofilm exhibited reduced thickness compared to wild type. Preliminary infection results indicate a possible adhesion defect in mutant bacteria, therefore reducing invasion in colon cells. However, wild type and mutant biofilms demonstrated no difference in susceptibility to antimicrobials. We conclude that the S1289 protein potentially contributes to biofilm formation and adherence of S. flexneri to HT‐29 cells.Support or Funding InformationUPR‐PRISE Program. Funded by NIH‐NIGMS #2R25GM096955This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

THE IMPORTANCE OF THE FUNCTIONAL STATE OF THIOL-DISULFIDE UNIT OF THE ANTIOXIDANT SYSTEM IN THE ACUTE BACTERIAL DYSENTERY IN THE FORECAST OF THE COURSE AND THE SELECTION OF THE TREATMENT REGIMEN

The goal was to optimize the treatment of shigellosis patients on the basis of an evaluation of the functional state of the thiol-disulfide unit of the antioxidant system (AOS) on a background of various treatment methods. Materials and methods. 400 patients with acute bacterial dysentery of varying severity of the course were observed; Shigella Flexner was isolated in 324(81%) cases, Shigella Sonne - in 76(19%) cases. The determination of sulfhydryl (SH-) groups and disulfide bonds (SS-) was carried out by the direct and reverse amperometric titration with the use of silver nitrate and unithiol in hemolysate. Three groups separated by random sampling were considered. In group I (122 patients), basic therapy was prescribed, including etiotropic and pathogenetic treatment. In group II (134 patients), pathogenetic treatment was prescribed in the combination with a complex of natural cytokines and antimicrobial peptides secreted by pig peripheral blood leukocytesa (»superlimph» preparation). In the third group (144 patients), the drug «superlimph» was prescribed along with etiotropic and pathogenetic treatment. Results. In acute bacterial dysentery disturbances of the redox balance were established to be correlated with the severity of the course in the form of a significant decrease in the level of SH-groups and the thiol-disulfide coefficient on the background of an increase in the level of SS-groups, which indicates to a decrease in the buffer capacity of the AOS. These data can serve as predictors of the nature of the course of dysentery. Comparative clinical evaluation of the effectiveness of various treatment methods revealed the most pronounced in severe disease advantages of complex therapy, including a combination of basic etiotropic, pathogenetic treatment with a complex of natural cytokines and antimicrobial peptides («superlimph»). Conclusion. The change in the ratio of oxidative processes to AOS occurs at any severity of dysentery, but in severe cases these changes acquire a qualitative character. In the survey standards for bacterial dysentery there is recommended to include the determination of indices of the thiol-disulfide unit, as an additional criterion for the severity of the course and the prognosis of the course of the disease. Exceeding the concentration of SS-groups of the concentration of SH-groups and the inversion of the thiol-disulfide coefficient as markers of the breakdown in AOS seem to be prognostically unfavorable factor. The severe course of acute bacterial dysentery is an indication for inclusion of antioxidant agents in the therapeutic complex. Based on the mechanism of revealed abnormalities in AOS, the use of a complex of natural cytokines and antimicrobial peptides («superlimph») can be considered as an immunocorrecting drug.

JAID/JSC Guidelines for Infection Treatment 2015-Intestinal infections.

JAID/JSC Guidelines for Infection Treatment 2015-Intestinal infections.

Immunogenic evaluation of chimeric recombinant protein against ETEC, EHEC and Shigella.

Diarrheal diseases still remain health problem worldwide and out of many bacteria responsible for, Shigella and pathogenic Escherichia cause the most diarrheas in the world. Shigellacause bacterial dysenteries and shigellosis through invasion where the most effective proteins for pathogenesis is Ipac. Critical virulence protein for ETEC infection is CFA/I with two subunits called cfab and cfae. . Attachment of EHEC is the main step of infection and the protein Intimin plays the key role in this function. Protection against the vast majority of responsible pathogens of diarrheas requires development of the combination vaccine against Shigella, ETEC and EHEC. In the present study, a multisubunitprotein (CII) containing immunologically significant parts of CfaB, IpaC and Intimin was designed. The chimeric gene (CII) was codon optimized and analyzed with different bioinformatic servers, then synthesized and expressed in E. coli. Mice, Guinea pig and, Caco-2 Cell line were used as challenge models for EHEC, shigella and ETEC respectively. The chimeric protein induced significant immune response and therefore could be a suitable vaccine candidate against these three pathogens.

Cardiolipin Synthesis and Outer Membrane Localization Are Required for Shigella flexneri Virulence.

ABSTRACTCardiolipin, an anionic phospholipid that resides at the poles of the inner and outer membranes, is synthesized primarily by the putative cardiolipin synthase ClsA in Shigella flexneri. An S. flexneri clsA mutant had no cardiolipin detected within its membrane, grew normally in vitro, and invaded cultured epithelial cells, but it failed to form plaques in epithelial cell monolayers, indicating that cardiolipin is required for virulence. The clsA mutant was initially motile within the host cell cytoplasm but formed filaments and lost motility during replication and failed to spread efficiently to neighboring cells. Mutation of pbgA, which encodes the transporter for cardiolipin from the inner membrane to the outer membrane, also resulted in loss of plaque formation. The S. flexneri pbgA mutant had normal levels of cardiolipin in the inner membrane, but no cardiolipin was detected in the outer membrane. The pbgA mutant invaded and replicated normally within cultured epithelial cells but failed to localize the actin polymerization protein IcsA properly on the bacterial surface and was unable to spread to neighboring cells. The clsA mutant, but not the pbgA mutant, had increased phosphatidylglycerol in the outer membrane. This appeared to compensate partially for the loss of cardiolipin in the outer membrane, allowing some IcsA localization in the outer membrane of the clsA mutant. We propose a dual function for cardiolipin in S. flexneri pathogenesis. In the inner membrane, cardiolipin is essential for proper cell division during intracellular growth. In the outer membrane, cardiolipin facilitates proper presentation of IcsA on the bacterial surface.

The Galleria mellonella larvae as an in vivo model for evaluation of Shigella virulence

ABSTRACTShigella spp. causing bacterial diarrhea and dysentery are human enteroinvasive bacterial pathogens that are orally transmitted through contaminated food and water and cause bacillary dysentery. Although natural Shigella infections are restricted to humans and primates, several smaller animal models are used to analyze individual steps in pathogenesis. No animal model fully duplicates the human response and sustaining the models requires expensive animals, costly maintenance of animal facilities, veterinary services and approved animal protocols. This study proposes the development of the caterpillar larvae of Galleria mellonella as a simple, inexpensive, informative, and rapid in-vivo model for evaluating virulence and the interaction of Shigella with cells of the insect innate immunity. Virulent Shigella injected through the forelegs causes larvae death. The mortality rates were dependent on the Shigella strain, the infectious dose, and the presence of the virulence plasmid. Wild-type S. flexneri 2a, persisted and replicated within the larvae, resulting in haemocyte cell death, whereas plasmid-cured mutants were rapidly cleared. Histology of the infected larvae in conjunction with fluorescence, immunofluorescence, and transmission electron microscopy indicate that S. flexneri reside within a vacuole of the insect haemocytes that ultrastructurally resembles vacuoles described in studies with mouse and human macrophage cell lines. Some of these bacteria-laden vacuoles had double-membranes characteristic of autophagosomes. These results suggest that G. mellonella larvae can be used as an easy-to-use animal model to understand Shigella pathogenesis that requires none of the time and labor-consuming procedures typical of other systems.

The Comparison of Effect of Human Milk and Powdered Milk on the Shigella dysenteriae Invasion in Cell Culture

Background: Shigella species are the common etiologic agents of bacterial dysentery. Many epidemiological studies have shown that breastfeeding may protect infants against intestinal infections. Among the components of milk, glycosylated proteins inhibit the adhesion of enteric pathogens in the laboratory. Immunoglobulins mainly secretory immunoglobulin A, glycosylated compounds, and oligosaccharides of breast milk are associated with protection against different intestinal pathogens. Objectives: This study aimed to evaluate the effect of different proteins of breast milk and powdered milk on the invasion of Shigella colonies. Materials and Methods: To accomplish this goal, breast milk samples were provided from two donors in the first 6 months of breastfeeding and powdered milk with different brands were obtained from the market. Then the proteins were extracted by precipitation using ammonium sulfate and dialysis using dialysis bag and protein bands were separated through SDS-PAGE electrophoresis. Finally, the obtained milk proteins through Hela cells culture were tested and evaluated for the adhesion and invasion of the Shigella. Results: Our results revealed that the adhesion and invasion of Shigella stains were more inhibited by low concentrations of breast milk proteins in comparison with powdered milk. This concentration was about 2.75 mg/mL for the proteins of breast milk and 0.5 mg/mL for the proteins of powdered milk and this inhibition in different dilutions of breast milk was 71.21% and those of powdered milk was 27.19% in average. There was a significant difference between breast milk and powdered milk (P < 0.5) considering their inhibitory behavior. Conclusion: The results revealed that the components of breast milk inhibit the adhesion and consequently invasion of Shigella and inhibit bacterial dysentery.

ФАКТОРЫ ПЕРЕДАЧИ ИНФЕКЦИИ ПРИ РАСПРОСТРАНЕНИИ КИШЕЧНЫХ ЗАБОЛЕВАНИЙ В РАЗЛИЧНЫХ РЕГИОНАХ РЕСПУБЛИКИ ТАДЖИКИСТАН

Objective: The study of the waterway transmission as dominant, with the spread of intestinal infections. Methods: A retrospective analysis of the journals for the registration of infectious diseases, maps of epidemiological checkups of typhoid foci, dysentery, diarrheal diseases, infectious hepatitis A (HAV) for 1980-2015, as well as reports of the Republican and regional CSSES (Center for State Sanitary and Epidemiological Surveillance) on infectious diseases were carried out. Results: The dominance of the water factor under conditions of the specific weight of Flexner shigellosis during the period of under study ranged between 75-85%. Compared with typhoid fever and bacterial dysentery, the incidence of diarrhoea in the country during the analyzed period remains at a high enough level – from 629.0 to 1206.3, and in 2015, it rose sharply and reached 2150 per 100 thousand. The indicators for the Regions of Republican Subordination, Gorno-Badakhshan Autonomous Region and Khatlon Region varied the broad mass of the population. The performed complex of sanitary-epidemiological evaluation paths and transmission factors identified the dominant value of an aqueous (90%) and a minor role contact-domestic (6.2%) and food (3.8%) of acute intestinal infections transmission routes among the population. Conclusion: Typhoid fever, acute intestinal infections, dysentery, hepatitis A in the Republic of Tajikistan are a typical aquatic infection associated with the constant activity of the waterway transmission, which often causes large epidemic outbreaks. Keywords: Diarrheal diseases, intestinal infections, the source of drinking water-supply.

Epidemiology and etiology of bacillary dysentery in Xinjiang Uigur Autonomous Region, 2004-2014

Objective: To understand the epidemiological and etiological characteristics of bacillary dysentery in Xinjiang Uigur Autonomous Region (Xinjiang) during 2004-2014, and provide evidence for the prevention and control of bacillary dysentery. Methods: Descriptive epidemiological analysis was conducted by using the incidence data of bacillary dysentery in Xinjiang during 2004-2014 and the serotyping and the antibiotic susceptibility test of the pathogens isolated were performed. Results: A total of 123 238 cases of bacillary dysentery were reported in Xinjiang from 2004 to 2014. The average annual incidence of bacillary dysentery ranged from 25.91 per 100 000 to 76.04 per 100 000 and the average annual mortality ranged from 0.00 to 46.90 per 100 000. The incidence of bacillary dysentery was higher in eastern Xinjiang than other areas. The incidence peak was during July-September. The incidence of bacillary dysentery in males was higher than that in females. The incidence was highest in infants and young children under five years old. Most cases were children outside child care settings, farmers and students. Shigella flexneri was the predominant pathogen and F2a was the most frequently detected subtype. The isolated strains were highly resistant to streptomycin, penicillin, doxycycline and tetracycline. The resistant rates to penicillin, tetracycline, doxycycline and streptomycin increased with year. Up to 71.43% of the strains were resistant to more than five antibiotics. Conclusion: The incidence of bacillary dysentery was in decrease in Xinjiang from 2004 to 2014, but in some area, the incidence of bacterial dysentery was higher than national average level. It is necessary to strengthen the surveillance and conduct targeted prevention and control in areas and population at high risk and in season with high incidence. The serious drug resistance and multi drug resistance of the pathogens have posed challenge to the prevention and treatment of bacillary dysentery in Xinjiang.

Deletion of toxin-antitoxin systems in the evolution of Shigella sonnei as a host-adapted pathogen.

Pathogenic Shigella spp. are the leading cause of bacterial dysentery, with Shigella flexneri and Shigella sonnei accounting for around 90% of cases worldwide. Although S. flexneri causes most disease in low-income countries (following ingestion of contaminated food and/or water), S. sonnei predominates in wealthy countries and is mainly spread from person to person. Although both species contain a large virulence plasmid, pINV, that is essential for the organism to cause disease, little is known about its maintenance. Here, using a counterselectable marker within the virulence-encoding region of pINV, we show that the S. sonnei plasmid is less stable than that of S. flexneri, especially at environmental temperatures. GmvAT, a toxin-antitoxin system, is responsible for the difference in stability and is present in pINV from S. flexneri but absent in S. sonnei pINV. GmvT is an acetyltransferase toxin that inhibits protein translation. Loss of GmvAT and a second toxin-antitoxin system, CcdAB, from pINV reduces S. sonnei plasmid stability outside the host, reflecting the host-adapted lifestyle and person-to-person transmission of this species and differences in its epidemiology.

ANTI-DYSENTERY ACTIVITY OF TETRACYCLINE IN COMBINATION WITH CURCUMA XANTHORRHIZA ROXB. OR SONCHUS ARVENSIS L.

Background: Bacterial dysentery, a diarrhea caused by Shigella sp. infection, causes a major morbidity and mortality in rural communities of developing countries. In Indonesia, most of the dysentery patients often use antibiotics in combination with herbal medicine to enhance the effect. Objective: This research aimed to examine the effect of tetracycline in combination with Curcuma xanthorrhiza Roxb. or Sonchus arvensis L. as an anti-dysentery. Methods: Antibacterial activity of each extract against Shigella flexneri was determined by using microdilution method. Furthermore, its activity in combination with tetracycline was determined by using checkerboard method. To assess its effect in in vivo, the drug combination was given orally into S. flexneri–infected rat for 7 consecutive days and total plate count in the feces of the rats were determined. Results: The minimum inhibitory concentration (MIC) of tetracycline, ethanol extract of C. xanthorrhiza and S. arvensis against S. flexneri was 4, 128, and 512 mg/100μL, respectively. The combination of each extract with tetracyline could reduce their MIC value, but the total MIC was not lower than 0.5, suggesting an additive interaction. However, in in vivo study, both combinations could reduce the number of bacteria found in the feces of the rat significantly compared to positive control and to tetracycline only-treated rat at day 6 after administration of the drug, suggesting a synergistic interaction. Conclusion: Combination of tetracycline with ethanol extract of C. xanthorrhiza or with S. arvensis is potential to be developed as anti-dysentery drugs against Shigella flexneri.

Molecular diagnosis and anti-microbial resistance patterns among Shigella spp. isolated from patients with diarrhea.

This study aims to determine the serogroup distribution and molecular diagnosis, as well as antimicrobial resistance profiles among Shigella spp. isolated from patients with diarrhea in Kerman, southeast of Iran. Shigella species are frequent cause of bacterial dysentery worldwide. Previous studies have been reported that S. sonnei and S. flexneri are the most prevalent serogroups in various parts of Iran. A total of 624 stool samples were randomly collected from patients with diarrhea from June 2013 to August 2014. Biochemical and serological characterizations were performed for identifying Shigella spp. In addition, the multiplex PCR assay was carried out for the detection and differentiation of three pathogenic Shigella spp. Antibiotic susceptibility testing was performed according to the Clinical Laboratory Standards Institute (CLSI) guidelines. Fifty six (9%) Shigella strains were isolated from stool samples. The most common species were S. flexneri 31(55.4%), followed by S . sonnei 18(32.1%) and S. boydii 7(12.5%). S. dysentery was not detected in the present study. All the isolates that identified by serological test as Shigella spp. were confirmed by the multiplex PCR method. The highest rate of resistance was observed for ampicillin and trimethoprim-sulphamethoxazole antibiotics with 52(92.9%) resistant, followed by tetracycline 44(78.6%) and cefotaxime 33(58.9%). All Shigella isolates were susceptible to ciprofloxacin. A significant relationship was found between the Shigella species and cefotaxime resistance (p<0.05). S. flexneri was found as the most prevalent serogroup causing shigellosis. The high rate of resistance to third-generation cephalosporins limits the treatment options available for the management of shigellosis in Kerman, Iran.

Cytotoxicity and cell cycle arrest induced by andrographolide lead to programmed cell death of MDA-MB-231 breast cancer cell line.

BackgroundBreast cancer is considered as an increasing major life-threatening concern among the malignancies encountered globally in females. Traditional therapy is far from satisfactory due to drug resistance and various side effects, thus a search for complementary/alternative medicines from natural sources with lesser side effects is being emphasized. Andrographis paniculata, an oriental, traditional medicinal herb commonly available in Asian countries, has a long history of treating a variety of diseases, such as respiratory infection, fever, bacterial dysentery, diarrhea, inflammation etc. Extracts of this plant showed a wide spectrum of therapeutic effects, such as anti-bacterial, anti-malarial, anti-viral and anti-carcinogenic properties. Andrographolide, a diterpenoid lactone, is the major active component of this plant. This study reports on andrographolide induced apoptosis and its possible mechanism in highly proliferative, invasive breast cancer cells, MDA-MB-231 lacking a functional p53 and estrogen receptor (ER). Furthermore, the pharmacokinetic properties of andrographolide have also been studied in mice following intravenous and oral administration.ResultsAndrographolide showed a time- and concentration- dependent inhibitory effect on MDA-MB-231 breast cancer cell proliferation, but the treatment did not affect normal breast epithelial cells, MCF-10A (>80 %). The number of cells in S as well as G2/M phase was increased after 36 h of treatment. Elevated reactive oxygen species (ROS) production with concomitant decrease in Mitochondrial Membrane Potential (MMP) and externalization of phosphatidyl serine were observed. Flow cytometry with Annexin V revealed that the population of apoptotic cells increased with prolonged exposure to andrographolide. Activation of caspase-3 and caspase-9 were also noted. Bax and Apaf-1 expression were notably increased with decreased Bcl-2 and Bcl-xL expression in andrographolide-treated cells. Pharmacokinetic study with andrographolide showed the bioavailability of 9.27 ± 1.69 % with a Cmax, of 0.73 ± 0.17 μmol/L and Tmax of 0.42 ± 0.14 h following oral administration. AG showed rapid clearance and moderate terminal half lives (T1/2) of 1.86 ± 0.21 and 3.30 ± 0.35 h following IV and oral administration respectively.ConclusionThis investigation indicates that andrographolide might be useful as a possible chemopreventive/chemotherapeutic agent for human breast cancers.Electronic supplementary materialThe online version of this article (doi:10.1186/s12929-016-0257-0) contains supplementary material, which is available to authorized users.

Implications of Spatiotemporal Regulation of Shigella flexneri Type Three Secretion Activity on Effector Functions: Think Globally, Act Locally.

Shigella spp. are Gram-negative bacterial pathogens that infect human colonic epithelia and cause bacterial dysentery. These bacteria express multiple copies of a syringe-like protein complex, the Type Three Secretion apparatus (T3SA), which is instrumental in the etiology of the disease. The T3SA triggers the plasma membrane (PM) engulfment of the bacteria by host cells during the initial entry process. It then enables bacteria to escape the resulting phagocytic-like vacuole. Freed bacteria form actin comets to move in the cytoplasm, which provokes bacterial collision with the inner leaflet of the PM. This phenomenon culminates in T3SA-dependent secondary uptake and vacuolar rupture in neighboring cells in a process akin to what is observed during entry and named cell-to-cell spread. The activity of the T3SA of Shigella flexneri was recently demonstrated to display an on/off regulation during the infection. While the T3SA is active when bacteria are in contact with PM-derived compartments, it switches to an inactive state when bacteria are released within the cytosol. These observations indicate that effector proteins transiting through the T3SA are therefore translocated in a highly time and space constrained fashion, likely impacting on their cellular distribution. Herein, we present what is currently known about the composition, the assembly and the regulation of the T3SA activity and discuss the consequences of the on/off regulation of T3SA on Shigella effector properties and functions during the infection. Specific examples that will be developed include the role of effectors IcsB and VirA in the escape from LC3/ATG8-positive vacuoles formed during cell-to-cell spread and of IpaJ protease activity against N-miristoylated proteins. The conservation of a similar regulation of T3SA activity in other pathogens such as Salmonella or Enteropathogenic Escherichia coli will also be briefly discussed.

Patterns of Acute Non Amebiasis Dysentery in Adults

iarrhea is still a major cause of death in many People all over the world. Acute diarrhea causes 3 million people death annually. Etiologic agents for bacterial dysentery are: Shigella (dysenteria, flexneri, boydii, sonnei), Salmonella (Typhi and para typhi), Campylobacter (jejuni) and Yersinia (entero colitica). The most common agent in developing countries is shigella Dysenteria and in developed countries is campylobacter jejuni [1]. While dysentery is a self limited disease, the antibiotic treatment not only reduces the symptomatic time, but also the excretion of the microbes, preventing its infection exposing other people [2]. The present study was aimed to determine patterns of acute non amebiasis dysentery in adult. This cross-sectional study performs in 2012. Patients with acute invasive diarrhea (bloody or mucoid diarrhea) for shorter than 3 days duration or watery diarrhea with fever or chill or tenesmus enrolled. Exclusion criteria were lactating and pregnant women, antibiotic therapy in 72 h past, patients with high toxicity and poor general condition and complications. In first, we get from all patients a sample of stool for direct examination and culture and antibiogram. Dysentery confirmed by positivity stool for WBC and RBC without amebiasis, then some of patients received azithromycin and other group received tab ciprofloxacin 500 mg/12 h for 5 days. After 48 h patients were examined for fever, general condition, decreased diarrhea and tenesmus. For patients with good clinical response, duration of treatment completed for 5 days but in groups without good clinical response, with use of results of culture and antibiogram, treatment changed. Stool culture was done from all patients in 5th day after treatment. Also patients evaluate for drug reactions in two groups. Data was analyzed using SPSS-11 software and χ test was used p<0.05 was set as the significant level. From 84 patients, 52 (61.9%) patients were male and 32 patients (38.9%) were female. In 29 (34.5%) patients culture result was negative. Shigella dysenteria cultured from 41 (48.8%) patients and other organisms (E. coli, Salmonella paratyphi A, Campylobacter jejuni cultured in 14 (16.6%) patients. Bloody diarrhea was seen at 38.1% patients and 27.3% had watery diarrhea and 32% mucoid and mixed diarrhea. From 55 patients that had antibiogram, 32 (58.1%) were sensitive to ciprofloxacin and 41 (74.4%) to azithromycin. Clinical response in azithromycin was more than ciprofloxacin 93.5% versus 88.6%. Stool cultures were negative in 100% patients at the end of treatment. In our study in patients with dysenteria, Shigella dysenteria is the most common etiologic agent but is not only bacterial etiology and other Gram negative bacillus example Salmonella paratyphi A, Campylobacter jejuni and E. coli. This may be to Shigella dysenteria low tolerance to hard environment conditions that it difficult Shigella dysenteria diagnosis or early antibiotic use by patients with dysenteria. Other studies showed quinolone resistance in Shigella (all species) has increased at an alarming speed, reinforcing the importance of continuous monitoring of antimicrobial resistance in Shigella (all species) [3]. In our study microbiological resistance for azithromycin was 19.3% and for ciprofloxacin was 23.8%, that indicated Shigella dysenteria resistant to new antibiotics example macrolides and quinolones is increased but clinical response to azithromycin and ciprofloxacin were good.