Genus Shigella Research Articles

Advances in Molecular Diagnostics

Advances in Molecular Diagnostics

Human Pathogens on or Within the Plant and Useful Endophytes

Copyright: © 2013 Akhtyamova N. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Several human pathogens and the plant can have close connection. A plant is not traditionally considered as a niche for human pathogen. But the literature data attest that many members of the family Enterobactericeae, including pathogenic Salmonella and Shigella genus strains, Vibrio cholerae strains, and the human opportunistic pathogen Pseudomonas aeruginosa, were found on plants or inside plants.

FREQUENCY OF Shigella flexneri SEROTYPES ISOLATED IN THE STATE OF PARÁ, BRAZIL (1979-2009)

The genus Shigella has been one of the most common causes of diarrhea in underdeveloped countries, being responsible for the mortality rate and morbidity in high risk populations such as children under five and the elderly. The aim of this study, developed at the Evandro Chagas Institute, Pará, Brazil, from 1979 to 2009, was to evaluate the frequency of species and serotypes of 122 isolates of Shigella spp. isolated from patients with acute diarrhea. The isolates were identified by bacterial culture media with selective indicators and biochemical tests, and serogroups and serotypes were determined by the slide agglutination test. The serogroups most frequently found were S. flexneri (66.4%) and S. sonnei (32.8%). The serotype 2a of S. flexneri was the most frequent (54.3%) followed by 1b (17.2%). Most patients were aged between 0-5 years (44.6%), of which 38.2% cases had S. flexneri and 47.5% S. sonnei. Patients older than 18 years accounted for 39.2% of infections, with 37.0% S. flexneri cases, 32.5% S. sonnei, and 100% S. boydii. These results emphasize the need for continuous surveillance in the State of Pará.

Characterization of Shigella sonnei in Malaysia, an increasingly prevalent etiologic agent of local shigellosis cases

BackgroundShigellosis is a major public health concern worldwide, especially in developing countries. It is an acute intestinal infection caused by bacteria of the genus Shigella, with a minimum infective dose as low as 10–100 bacterial cells. Increasing prevalence of Shigella sonnei as the etiologic agent of shigellosis in Malaysia has been reported. As there is limited information on the genetic background of S. sonnei in Malaysia, this study aimed to characterize Malaysian S. sonnei and to evaluate the prospect of using multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for subtyping of local S. sonnei.MethodsForty non-repeat clinical strains of S. sonnei isolated during the years 1997–2000, and 2007–2009 were studied. The strains were isolated from stools of patients in different hospitals from different regions in Malaysia. These epidemiologically unrelated strains were characterized using biotyping, antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE) and MLVA.ResultsThe two biotypes identified in this study were biotype a (n = 29, 73%) and biotype g (n = 11, 27%). All the 40 strains were sensitive to kanamycin, ceftriaxone and ciprofloxacin. Highest resistance rate was observed for streptomycin (67.5%), followed by tetracycline (40%) and trimethoprim-sulfamethoxazole (37.5%). All the S. sonnei biotype g strains had a core resistance type of streptomycin - trimethoprim-sulfamethoxazole - tetracycline whereas the 29 biotype a strains were subtyped into eight resistotypes. All the strains were equally distinguishable by PFGE and MLVA. Overall, PFGE analysis indicated that S. sonnei biotype a strains were genetically more diverse than biotype g strains. Cluster analysis by MLVA was better in grouping the strains according to biotypes, was reflective of the epidemiological information and was equally discriminative as PFGE.ConclusionsThe S. sonnei strains circulating in Malaysia throughout the period studied were derived from different clones given their heterogeneous nature. MLVA based on seven selected VNTR loci was rapid, reproducible and highly discriminative and therefore may complement PFGE for routine subtyping of S. sonnei.

Epidemiological, clinical features and susceptibility pattern of shigellosis in the buea health district, Cameroon

BackgroundShigellosis is an acute invasive enteric infection caused by bacteria belonging to the genus Shigella; it is clinically manifested by bloody diarrhoea. Shigellosis is endemic in many developing countries including Cameroon and also occurs in epidemics causing considerable morbidity and mortality. This study evaluated the epidemiological and clinical features of Shigella and the resistance pattern of isolates to commonly used antibiotics in the Buea Health District in Cameroon, from April to August, 2010.ResultsOf the 223 stool samples cultured, 10 (4.5%) yielded Shigella species. Isolation rate was observed to be more in children below 15 years (7.89%), and also higher in rural areas (6.35%). All 10 isolates showed resistance to at least two antibiotics and 9 (90%) were multi-drug resistant. The highest resistance rates were encountered with cotrimoxazole (90%) and amoxicillin (80%). Least resistance was observed with azithromycin (10%).ConclusionShigellosis is more prevalent in children below 15 years in the Buea District. There is a high level of resistance to most of the antibiotics used for the treatment of shigellosis including extended-spectrum beta-lactamases (ESBLs) as well as evidence of resistance to quinolones. Azithromycin was found to be the drug of choice for shigellosis in this setting.

A icsA-targeted PCR for rapid identification of Shigella spp.

Introduction: The genus Shigella contains four species (serogroups): S. dysenteria (serogroup A), S. flexneri (serogroup B), S. boydii (serogroup C), and S. sonnei (serogroup D). Shigella are highly infectious and a dose of 10–100 cells can cause infection. Virulent Shigella organisms cause the human illness known as bacillary dysentery. Bacillary dysentery (shigellosis) causes mild diarrhea, fever, abdominal cramps, and severe fluid loss. Shigella colonize and invade mucosal epithelial cells. Shigella produce icsA(intracellular spread)/VirG protein,a 116-kD surface-exposed outer membrane protein, which mediates actin polymerization to aid in bacterial movement inside the cell. The icsA protein is encoded by the virulence plasmid. IcsA consists of three major domains: an N-terminal signal sequence (amino acids [aa] 1 to 52), to direct Sec dependent protein transport across the inner-membrane; and a C-terminal translocation domain (aa 759 to 1102) that enables export of the remaining N-terminal region of icsA, the passenger domain (aa 53 to 758), across the OM. The purpose of this study was to develop speciesspecific PCR primers for detection of Shigella spp. Methods: A primer was designed for α-domain of icsA gene for the detection of Shigella. The icsA gene was amplified by using PCR and confirmed by sequencing. Results: Specificity data showed that PCR primers produce amplicons from all the Shigella spp., but not from the other species tested. These results suggested that these two PCR primers are quite sensitive in the detection of Shigella spp. in molecular epidemiological studies of shigellosis. Conclusion: This research proved that icsA gene specialized in Shigella spp. therefore icsA could be used for the detection of Shigella in clinical samples.

A multi-center randomized trial to assess the efficacy of gatifloxacin versus ciprofloxacin for the treatment of shigellosis in Vietnamese children.

BackgroundThe bacterial genus Shigella is the leading cause of dysentery. There have been significant increases in the proportion of Shigella isolated that demonstrate resistance to nalidixic acid. While nalidixic acid is no longer considered as a therapeutic agent for shigellosis, the fluoroquinolone ciprofloxacin is the current recommendation of the World Health Organization. Resistance to nalidixic acid is a marker of reduced susceptibility to older generation fluoroquinolones, such as ciprofloxacin. We aimed to assess the efficacy of gatifloxacin versus ciprofloxacin in the treatment of uncomplicated shigellosis in children.Methodology/Principal FindingsWe conducted a randomized, open-label, controlled trial with two parallel arms at two hospitals in southern Vietnam. The study was designed as a superiority trial and children with dysentery meeting the inclusion criteria were invited to participate. Participants received either gatifloxacin (10 mg/kg/day) in a single daily dose for 3 days or ciprofloxacin (30 mg/kg/day) in two divided doses for 3 days. The primary outcome measure was treatment failure; secondary outcome measures were time to the cessation of individual symptoms. Four hundred and ninety four patients were randomized to receive either gatifloxacin (n = 249) or ciprofloxacin (n = 245), of which 107 had a positive Shigella stool culture. We could not demonstrate superiority of gatifloxacin and observed similar clinical failure rate in both groups (gatifloxacin; 12.0% and ciprofloxacin; 11.0%, p = 0.72). The median (inter-quartile range) time from illness onset to cessation of all symptoms was 95 (66–126) hours for gatifloxacin recipients and 93 (68–120) hours for the ciprofloxacin recipients (Hazard Ratio [95%CI] = 0.98 [0.82–1.17], p = 0.83).ConclusionsWe conclude that in Vietnam, where nalidixic acid resistant Shigellae are highly prevalent, ciprofloxacin and gatifloxacin are similarly effective for the treatment of acute shigellosis.Trial RegistrationControlled trials number ISRCTN55945881

Molecular Characterization of Fecal Microbiota in Patients with Viral Diarrhea

The study provides molecular analyses of fecal microbiota of diarrhea patients infected with four different types of viruses. Fecal specimens from 52 patients with viral diarrhea (13 each of adenovirus, norovirus, rotavirus, and astrovirus) and six healthy individuals were collected and etiological viral agent was confirmed by enzyme immunoassay and specific PCR. To assess the changes in microbial diversity in patients with viral diarrhea, DNA from stool were extracted and characterized by PCR-denaturing gradient gel electrophoresis (DGGE) with universal primers specific for the V3 region of 16S rRNA gene. The strongest bands of the DGGE profiling were excised and sequenced to identify the dominant groups. Bacteroides vulgatus, Bifidobacterium, and Lactobacillus genera were also enumerated by real time PCR. The results revealed that bacterial diversity and similarity in feces from viral diarrhea groups were significantly lower (mean H'/ H'(max) 0.89-0.94, 29-43, respectively) as compared with those of healthy individuals (mean H'/ H'(max) 1.36, 59, respectively). Sequencing of dominant bands affirmed that diarrhea groups were mainly comprised of phylum Firmicutes, such as genera Enterococcus, Peptostreptococcaceae incertae sedi, Streptococcus, Weissella, and Clostridium, and opportunistically pathogenic genus Shigella, while dominant group in healthy individuals was phylum Bacteroidetes. Copy number of Bacteroides vulgatus, Bifidobacterium, and Lactobacillus genera was also reduced significantly in viral diarrhea groups as compared to healthy group. It is concluded that opportunistic pathogens increases, while other species of commensal microbiota decrease significantly in the viral diarrhea patients and dysbacteriosis is dependent on type of virus infection.

Predation of human pathogens by the predatory bacteria Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus

The focus of this study was to evaluate the potential use of the predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to control the pathogens associated with human infection. By coculturing B. bacteriovorus 109J and M. aeruginosavorus ARL-13 with selected pathogens, we have demonstrated that predatory bacteria are able to attack bacteria from the genus Acinetobacter, Aeromonas, Bordetella, Burkholderia, Citrobacter, Enterobacter, Escherichia, Klebsiella, Listonella, Morganella, Proteus, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio and Yersinia. Predation was measured in single and multispecies microbial cultures as well as on monolayer and multilayer preformed biofilms. Additional experiments aimed at assessing the optimal predation characteristics of M. aeruginosavorus demonstrated that the predator is able to prey at temperatures of 25-37°C but is unable to prey under oxygen-limiting conditions. In addition, an increase in M. aeruginosavorus ARL-13 prey range was also observed. Bdellovibrio bacteriovorus and M. aeruginosavorus have an ability to prey and reduce many of the multidrug-resistant pathogens associated with human infection. Infectious complications caused by micro-organisms that have become resistant to drug therapy are an increasing problem in medicine, with more infections becoming difficult to treat using traditional antimicrobial agents. The work presented here highlights the potential use of predatory bacteria as a biological-based agent for eradicating multidrug-resistant bacteria, with the hope of paving the way for future studies in animal models.

Research progress in Shigella in the postgenomic era

Gram-negative, facultative intracellular anaerobes of the genus Shigella, the principal etiologic agents of shigellosis, continue to pose a threat to public health. Shigellosis causes 1.1 million deaths with over 164 million annual cases. The Shigella spp. can be divided into four serogroups: Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei. The completion of seven Shigella genome sequences of representative strains from each of the Shigella species has introduced an era of whole-genome study. This paper reviews contemporary understanding of genomics, transcriptomics, proteomics and the structural biology of Shigella.

CLONING AND EXPRESSION OF N-TERMINAL REGION OF IPAD FROM SHIGELLA DYSENTERIAE IN E. COLI

Genus Shigella is one of the important members of the family enterobacteriacae. There are numerous antigens in Shigella carrying by a 220 kb plasmid. Among them, IpaD is the key virulence factor of S. flexneri. Apart from having effectors function that is essential for host cell invasion and intracellular survival, this protein also controls the secretion and translocation of other effector proteins into eukaryotic host cells. In the present study, we have cloned and expressed the ipaD in E. coli. The ipaD gene was amplified by PCR. Prokaryote expression vector pET-28a(+)- ipaD was constructed, and used to transform E. coli BL21DE3 plySs. The expression of recombinant protein induced by IPTG was examined by SDS-PAGE. Western blot were used to determine immunoreactivity of IpaDHis by a rabbit monoclonal antibodies against his-tag. SDS-PAGE demonstrated that the constructed prokaryotic expression efficiently produced IpaD at the 1 mmol/L of IPTG. IpaD protein was able to react with the rabbit monoclonal antibody against His-tag. IpaD is essential for Shigella spp invasion. N-terminal region is most significant functional fragment of IpaD. Purification of IpaD from the wild type of Shigella is difficult furthermore profound study on a specific domain on the N-terminal of IpaD by using the wild type of purified IpaD is not feasible.

A changing picture of shigellosis in southern Vietnam: shifting species dominance, antimicrobial susceptibility and clinical presentation

BackgroundShigellosis remains considerable public health problem in some developing countries. The nature of Shigellae suggests that they are highly adaptable when placed under selective pressure in a human population. This is demonstrated by variation and fluctuations in serotypes and antimicrobial resistance profile of organisms circulating in differing setting in endemic locations. Antimicrobial resistance in the genus Shigella is a constant threat, with reports of organisms in Asia being resistant to multiple antimicrobials and new generation therapies.MethodsHere we compare microbiological, clinical and epidemiological data from patients with shigellosis over three different periods in southern Vietnam spanning14 years.ResultsOur data demonstrates a shift in dominant infecting species (S. flexneri to S. sonnei) and resistance profile of the organisms circulating in southern Vietnam. We find that there was no significant variation in the syndromes associated with either S. sonnei or S. flexneri, yet the clinical features of the disease are more severe in later observations.ConclusionsOur findings show a change in clinical presentation of shigellosis in this setting, as the disease may be now more pronounced, this is concurrent with a change in antimicrobial resistance profile. These data highlight the socio-economic development of southern Vietnam and should guide future vaccine development and deployment strategies.Trial RegistrationCurrent Controlled Trials ISRCTN55945881

Molecular Methods for Detecting and Discriminating Shigella Associated with Foods and Human Clinical Infections — A Review

There are four species of the genus Shigella: S. dysenteriae, S. flexneri, S. sonneii, and S. boydii. It is extremely difficult if not impossible to utilize the PCR for distinguishing between shigellae and the five diarrheagenic pathotypes of Escherichia coli—enterohemolytic (EHEC), enteropathogenic (EPEC), engteroinvasive (EIEC), enterotoxigenic (ETEC), and enteroaggresive (EAEC)—due to the extremely close genetic relationship between Shigella spp. and E. coli. This problem is magnified by the presence of common virulence plasmids in these two microbial groups with virulence genes of extremely high homology. Although gastrointestinal infections by shigellae and EICC occur most frequently in developing nations, the responsible E. coli strains are indistinguishable from shigellae by PCR. In addition, with the exception of S. boydii, the other three species of Shigella are completely indistinguishable from one another by the PCR. The most fruitful approach to date in attempting to use the PCR for distinguishing the four species of Shigella from one another has been to first use immuno-capture based on somatic O antigenicity immediately prior to the use of the PCR to impart species selectivity to a coupled ELISA-PCR assay system. Most PCR assays involving the detection of shigellae have been designed to detect shigellae plus the E. coli pathotype EIEC as a collective and indistinguishable group of enteroinvasive organisms or to distinguish Shigella from pathogenic members of other pathogenic genera.

Virulence factors and in vitro susceptibility of Plesiomonas shigelloides isolated from diarrhea episodes in Cuba

Acute diarrhea is still one of the main causes of disease in developing countries. At the National Reference Laboratory for Acute Diarrhoeal Diseases, of the "Pedro Kourí" Tropical Medicine Institute, 54 Plesiomonas shigelloides strains were serotyped. As a result, the circulation of four new serotypes (O20:H2, 056:H18, 071 :H31,081 :H22) was detected. The most common antigenic variant was 094:H3. In addition, the susceptibility pattern to 21 antimicrobial agents (AA) was studied. Highest percentages of resistance were observed to ampicillin (77.7%), tetracycline (29.2%), and erythromycin (18.5%) while, to all other AA the resistance percentages were under 33%. There was no evidence of association between the serotypes and the multi-resistance patterns present in the strains under study. The frequency of virulence factors was determined: 21.15% of the strains turned out to be ss-haemolytic; 73.7% showed the presence of biofilm and 92.31% were hydrophobic. In 17.3% of the strains, the three virulence factors analysed were present. When establishing the relationship among the different virulence factors and the serotypes of the strains through cross reaction with the Shigella genus, there was evidence that 93.3% of the strains showed at least one of the virulence factors studied. Likewise, at least one of the virulence factors analysed was present in 90.9% of the multi-resistant strains.

Caracterización de factores de virulencia y susceptibilidad antimicrobiana en cepas de Plesiomonas shigelloides aisladas de pacientes con diarrea aguda en Cuba

Acute diarrhea is still one of the main causes of disease in developing countries. At the National Reference Laboratory for Acute Diarrhoeal Diseases, of the "Pedro Kourí" Tropical Medicine Institute, 54 Plesiomonas shigelloides strains were serotyped. As a result, the circulation of four new serotypes (O20:H2, 056:H18, 071 :H31,081 :H22) was detected. The most common antigenic variant was 094:H3. In addition, the susceptibility pattern to 21 antimicrobial agents (AA) was studied. Highest percentages of resistance were observed to ampicillin (77.7%), tetracycline (29.2%), and erythromycin (18.5%) while, to all other AA the resistance percentages were under 33%. There was no evidence of association between the serotypes and the multi-resistance patterns present in the strains under study. The frequency of virulence factors was determined: 21.15% of the strains turned out to be ss-haemolytic; 73.7% showed the presence of biofilm and 92.31% were hydrophobic. In 17.3% of the strains, the three virulence factors analysed were present. When establishing the relationship among the different virulence factors and the serotypes of the strains through cross reaction with the Shigella genus, there was evidence that 93.3% of the strains showed at least one of the virulence factors studied. Likewise, at least one of the virulence factors analysed was present in 90.9% of the multi-resistant strains.

Pyrosequencing™ analysis of the gyrB gene to differentiate bacteria responsible for diarrheal diseases

Pathogens causing acute diarrhea include a large variety of species from Enterobacteriaceae and Vibrionaceae. A method based on pyrosequencing was used here to differentiate bacteria commonly associated with diarrhea in China; the method is targeted to a partial amplicon of the gyrB gene, which encodes the B subunit of DNA gyrase. Twenty-eight specific polymorphic positions were identified from sequence alignment of a large sequence dataset and targeted using 17 sequencing primers. Of 95 isolates tested, belonging to 13 species within 7 genera, most could be identified to the species level; O157 type could be differentiated from other E. coli types; Salmonella enterica subsp. enterica could be identified at the serotype level; the genus Shigella, except for S. boydii and S. dysenteriae, could also be identified. All these isolates were also subjected to conventional sequencing of a relatively long ( approximately1.2 kb) region of gyrB DNA; these results confirmed those with pyrosequencing. Twenty-two fecal samples were surveyed, the results of which were concordant with culture-based bacterial identification, and the pathogen detection limit with simulated stool specimens was 10(4) CFU/ml. DNA from different pathogens was also mixed to simulate a case of multibacterial infection, and the generated signals correlated well with the mix ratio. In summary, the gyrB-based pyrosequencing approach proved to have significant reliability and discriminatory power for enteropathogenic bacterial identification and provided a fast and effective method for clinical diagnosis.

Shigellose ou dysenterie bacillaire

Shigellosis, commonly known as bacillary dysentery, is an enterobacterial disease caused by the Shigella genus, which now belongs to the Escherichia tribe, because of their genetic and phenotypic similarities. S. sonnei, flexneri, boydii and dysenteriae differ in their epidemiologic and pathogenic characteristics. S. sonnei is predominant in industrialized countries and causes the mildest disease. S. dysentery is especially dangerous because it occurs in outbreaks, sometimes in catastrophic situations, and has a high mortality rate. Shigellosis typically causes watery diarrhea followed by dysentery. It may be associated with a variety of mild to severe or even life-threatening complications. Shigellosis is a significant public health problem in developing countries where it remains a major cause of diarrhea-related morbidity and mortality, especially among children. Annual cases worldwide are estimated at 160 million. Shigellosis is a highly contagious disease of poor and crowded communities, with fecal-oral (hand-to-mouth) transmission, and an extremely low minimum infectious dose. Multidrug resistance is a serious problem. Ciprofloxacin is the first-line antibiotic, recommended for 3 days. Prevention and control should include personal hygiene, hand washing, sanitation, and water supply. No vaccine is available, but several candidates are currently being evaluated.

<i>Enterobacteriaceae</i> Family Bacteria In A Mesotrophic Lake (Lake Długie Wigierskie) in the Presence of Black Cormorants (<i>Phalocrocorax Carbo</i>)

Counts of Enterobacteriaceae family bacteria were assayed in the water of Dlugie Wigierskie Lake, which are situated in Wigry National Park and is settled by a colony of about 1000 black cormorants. The studied were conducted at monthly intervals in spring, summer and autumn of 2000-2001. Water samples were collected at 14 sites. Counts of Enterobacteriaceae family bacteria in the water of Dlugie Wigierskie Lake were very small in studied capacity water samples. The highest numbers of these bacteria not exceed 910 in 1 cm 3 ; simetimes, no presence of these bacteria was determined. Enterobacteriaceae family bacteria was determined in higher numbers from July to September, especially in the water sampled at the sites located in the areas inhabited by cormorants. Among the bacteria which belong to the Enterobacteriaceae family bacteria Enterobacter gergoviae (15.5%), Klebsiella oxytoca (9.8%), Serratia odorifera (9.8%), Citrobacter freundii (9.2%) and Enterobacter cloacae (7.6%) were most numerous, whereas pathogenic Salmonella and Shigella genus were not detected in water samples.

Epidemiology of Shigellosis in Korea

Shigellosis is an acute diarrheal disease caused by bacteria of the genus Shigella. Following the occurrence of a large outbreak of shigellosis as well as sporadic cases since 1998, shigellosis has been a major health problem in Korea. There have been major changes in epidemiology during the last five decades concerning shigellosis in terms of total incidence of shigellosis, prevalence of certain serogroups, selection of specific clones, and introduction of new Shigella clones. S. dysenteriae was the most prevalent species until the early twentieth century, S. flexneri was the most prevalent until the late 1980s, and S. sonnei has been the most prevalent since 1990. Diverse serotypes of S. dysenteriae (4 serotypes), S. flexneri (8 serotypes), and S. boydii (4 serotypes) were found during the Korean War and many of these Korean endemic Shigella strains circulated in the community until the late 1970s. However, the endemic strains of S. dysenteriae, S. boydii, and S. sonnei disappeared in the late 1980s. A new clone of S. sonnei that was introduced between the late 1980s and the early 1990s was responsible for a large proportion of shigellosis in recent years. S. flexneri serotype 4a was the most frequently found during the Korean War and then the incidence of S. flexneri 2a gradually increased with time. S. flexneri isolates detected from 1991 to 1997 were all serotype 2a. However, the diverse clones of S. flexneri reemerged in Korea since 1999. It has not been determined whether the S. flexneri strains from the 2000s were the descendants of the Korean endemic strains or imported new strains, but the PFGE patterns were different between S. flexneri strains from the 1980s and 2000s. The widespread of new S. sonnei strains and the persistence of S. flexneri strains are responsible for the endemicity of shigellosis in Korea.

Shigella infections in children: New insights

Shigellosis , the acute enteric infection caused by bacteria of the genus Shigella , has a worldwide distribution with an estimated annual incidence of 164.7 million cases, of which 163.2 million occur in developing countries, and 1.1 million deaths. Sixty-nine percent of all episodes and 61 percent of all Shigella -related deaths involve children younger than 5 years old. In the United States, 10,000 to 15,000 cases of shigellosis are reported each year. Although usually confined to the colonic mucosa, shigellosis sometimes can cause extraintestinal complications. Recent publications have shed light on the clinical characteristics of Shigella -induced bacteremia, surgical complications, urogenital symptoms, and neurologic manifestations, and on the unique manifestations in the neonatal period. The mainstay of treatment of shigellosis in children is correction of the fluid and electrolyte loss, which often is achieved by the administration of oral rehydration solutions. Appropriate antibiotic therapy shortens the duration of both clinical symptoms and fecal excretion of the pathogen. However, the increasing antimicrobial resistance of shigellae worldwide constitutes a major problem. Regarding the pathophysiology of shigellosis and its complications, recent data not only elucidated the molecular mechanisms involved but also linked manifestations of disease to the interplay of bacterial virulence factors and host responses. The improved understanding of the pathophysiology is hoped to lead to innovative therapeutic approaches against shigellosis and new generations of vaccine candidates.