Shigella flexneri, S. sonnei, S. dysenteriae, and S. boydii. Conventional treatment regimens for Shigella have been less effective due to the development of resistant strains against antibiotics. Therefore, an effective vaccine for the long term control of Shigella transmission is urgently needed.MATERIALS AND METHODS: In this study, a reverse vaccinology approach was employed to identify most conserved and immunogenic outer membrane proteins (OMPs) of S. flexneri 2a.RESULTS: Five OMPs including fepA, ompC, nlpD_1, tolC, and nlpD_2 were identified as potential vaccine candidates. Protein-protein interactions analysis using STRING software (https://string-db.org/) revealed that five of these OMPs may potentially interact with other intracellular proteins which are involved in beta-lactam resistance pathway. B- and T-cell epitopes of the selected OMPs were predicted using BCPred as well as Propred I and Propred (http://crdd.osdd.net/raghava/propred/), respectively. Each of these OMPs contains regions which are capable to induce B- and T-cell immune responses.CONCLUSION: Analysis acquired from this study showed that five selected OMPs have great potential for vaccine development against S. flexneri infection. The predicted immunogenic epitopes can also be used for development of peptide vaccines or multi-epitope vaccines against human shigellosis. Reverse vaccinology is a promising strategy for the discovery of potential vaccine candidates which can be used for future vaccine development against global persistent infections.]]>
Anti-Bacterial Agents ; beta-Lactam Resistance ; Computational Biology ; Dysentery, Bacillary ; Enterobacteriaceae ; Epitopes ; Epitopes, T-Lymphocyte ; Humans ; Membrane Proteins ; Membranes ; Shigella flexneri ; Shigella ; T-Lymphocytes ; Vaccines ; Vaccines, Subunit

Objective: To analyze the pathogenic surveillance programs and related factors on bacillary dysentery in Beijing, 2008-2017, to provide evidence for the practices of diagnosis, treatment and prevention of the disease. Methods: Analysis was conducted on surveillance data of bacillary dysentery, collected from the surveillance areas of national bacillary dysentery in Beijing. Shigella positive rate of stool samples were used as the gold standard while detection rate of Shigella, diagnostic accordance rate and resistance were computed on data from the surveillance programs. Chi-square test was used to compare the rates and unconditional logistic regression was used to analyze the related factors of Shigella infection. Results: Both the reported incidence rate on bacillary dysentery and detection rate of Shigella in diarrhea patients showed significantly decreasing trend, from 2008 to 2017. The accordance rate of bacillary dysentery was only 7.80% (111/1 423). Shigella sonnei was the most frequently isolated strain (73.95%, 159/215) followed by Shigella flexnery. Results from the multivariate logistic regression of Shigella positive rate revealed that among those patients who were routine test of stool positive vs. routine test of stool positive (OR=1.863, 95%CI: 1.402-2.475), onset from July to October vs. other months'time (OR=7.271, 95%CI: 4.514-11.709) temperature ≥38 ℃vs. temperature <38 ℃(OR=4.516, 95%CI: 3.369-6.053) and age from 6 to 59 years old vs. other ages (OR=1.617, 95%CI: 1.085-2.410), presenting higher positive detection rates of Shigella from the stool tests. The resistant rates on ampicillin and nalidixic acid were 97.57% (201/206) and 94.90% (186/196), both higher than on other antibiotics. The resistant rates on ciprofloxacin (16.33%, 32/196), ofloxacin (9.57%, 11/115) and on amoxilin (15.05%, 31/206) were relatively low. The resistant rate appeared higher on Shigella flexnery than on Shigella sonnei. The proportion of strains with resistance on 3 more drugs, was 30.00%(21/70). Conclusions: The diagnostic accordance rate of bacillary dysentery in Beijing was low, with severe resistance of Shigella. Our findings suggested that clinicians should take multiple factors into account in their practices about epidemiological history, clinical symptom and testing results for diarrhea patients.
Adolescent ; Adult ; Anti-Bacterial Agents/therapeutic use* ; Beijing/epidemiology* ; Child ; China/epidemiology* ; Dysentery, Bacillary/prevention & control* ; Feces/microbiology* ; Humans ; Middle Aged ; Population Surveillance/methods* ; Sentinel Surveillance ; Shigella/isolation & purification* ; Shigella flexneri/isolation & purification* ; Shigella sonnei/isolation & purification* ; Young Adult

BACKGROUND: The emergence of fosfomycin resistance and extended-spectrum β-lactamase (ESBL) genes is a serious threat to public health and a new challenge in shigellosis treatment. The purpose of this study was to identify fosfomycin resistance and characterize β-lactamase genes in fos-carrying isolates of Shigella flexneri from patients in China. METHODS: A total of 263 S. flexneri isolates were collected from 34 hospitals in the Anhui Province of China during September 2012-September 2015 and screened for fosA3, fosA, and fosC2 by PCR amplification and sequencing. The fos-carrying isolates were then screened for β-lactamase genes. The clonal relationships between fosA3-carrying isolates, the transmissibility of fosfomycin resistance, replicon types of plasmids carrying fosfomycin resistance genes and other associated resistance genes were investigated. RESULTS: Twenty-five of the 263 isolates (9.5%) showed resistance to fosfomycin, and 18 (6.8%) were positive for fosA3. None of the isolates was positive for fosA or fosC2. Seventeen of the isolates carrying fosA3 (94%) were CTX-M producers (seven CTX-M-55, five CTX-M-14, and five CTX-M-123), while three (16.7%) were TEM producers (TEM-1).Sixteen (88.9%) fosA3-carrying isolates exhibited multi-drug resistance. The replicon types of the 13 fosA3-carrying plasmids were IncF (n=13), IncHI2 (n=3), IncIl-Ir (n=2), and IncN (n=1). CONCLUSIONS: Our results indicated that fosA3 could spread through plasmids in S. flexneri isolates, along with the bla(CTX-M) and bla(TEM), which facilitate its quick dispersal. To the best of our knowledge, this is the first report of CTX-M-123-type ESBLs in S. flexneri isolates from patients in China.
China* ; Drug Resistance, Multiple ; Dysentery, Bacillary ; Fosfomycin* ; Humans ; Plasmids ; Polymerase Chain Reaction ; Public Health ; Replicon ; Shigella flexneri* ; Shigella*

OBJECTIVES: An atypical Shigella flexneri strain with a plural agglutination pattern [i.e., reacting not only with serum samples containing type antigen II but also with serum samples containing group antigens (3)4 and 7(8)] was selected for genome sequencing, with the aim of obtaining additional comparative information about such strains. METHODS: The genomic DNA of atypical S. flexneri strain NCCP 15744 was sequenced using an Ion Torrent PGM sequencing machine (Life Technologies, USA). The raw sequence data were preprocessed and reference-assembled in the CLC Assembly Cell software (version 4.0.6; CLC bio, USA). RESULTS: Ion Torrent sequencing produced 1,450,025 single reads with an average length of 144 bp, totaling ~209 Mbp. The NCCP 15744 genome is composed of one chromosome and four plasmids and contains a gtrX gene. Among the published genome sequences of S. flexneri strains, including 2457T, Sf301, and 2002017, strain NCCP 15744 showed high similarity with strain 2002017. The differences between NCCP 15744 and 2002017 are as follows: i) NCCP 15744 carries four plasmids whereas 2002017 carries five; ii) 19 genes (including CI, CII, and cro) were lost in the SHI-O genomic island of NCCP 15744 and six genes were gained as compared with strain 2002017. CONCLUSION: Strain NCCP 15744 is genetically similar to 2002017, but these two strains have different multilocus sequence types and serotypes. The exact reason is unclear, but the 19 lost genes may be responsible for the atypical seroconversion of strain NCCP 15744.
Agglutination ; DNA ; Genome* ; Genomic Islands ; Genomics ; Korea* ; Plasmids ; Sequence Analysis ; Seroconversion ; Serogroup ; Shigella flexneri* ; Shigella*

Shigella is a common cause of bacterial enteritis worldwide. Shigella sonnei accounts for 90% of Shigella infections and Shigella flexneri is rarely reported in Korea. Although the incidence of Shigella infection has decreased, the incidence of organisms with antibiotic resistance has gradually increased in Korea. An outbreak of extended-spectrum β-lactamase (ESBL)-producing S. sonnei in children was reported in Korea; however, ESBL-producing S. flexneri has not yet been reported. We report the first two cases of multidrug-resistant CTX-M-14-producing S. flexneri infections in Korean children.
beta-Lactamases ; Child* ; Drug Resistance, Microbial ; Enteritis ; Humans ; Incidence ; Korea* ; Shigella flexneri* ; Shigella sonnei ; Shigella*

OBJECTIVETo investigate the correlation between Shigella flexneri multi-drug resistance and drug resistance gene cassette of integrons.

METHODAll 79 strains of Shigella flexneri were isolated from the feces of children ranged in age from 6 months to 14 years in some hospitals of Jinan, between May 2009 and April 2012.The resistance was detected by Kirby Bauer agar diffusion method, 1, 2 and 3 integron gene was amplified by PCR, the variable region of positive strains treated with enzyme digestion and determined by Series Analysis.

RESULTAmong 79 Shigella flexneri strains, the resistance rate was 91% (72/79) to ampicillin, chloramphenicol, tetracycline, streptomycin, 70% (55/79) to sulfamethoxazole/trimethoprim, 30% (24/79), 23% (18/79), 33% (26/79) and 32% (25/79) to cefotaxime, ceftazidime, ciprofloxacin and levofloxacin.All 79 strains were susceptible to cefoxitin, imipenem, cefoperazone/sulbactam. The common drug resistance pattern is ampicillin tetracycline-chloramphenicol-streptomycin, accounted for 91% (72/79); 91% (72/79) strains carried integrons of class 1, 86% (68/79) strains carried integrons of class 2, No intI3 was detected. The resistance to ampicillin, streptomycin, tetracycline, chloramphenicol of atypical class 1 integron positive strains was significantly higher than the negative strains (χ² = 35.96, P<0.01). The sequencing results:dfrV was detected in class 1 integron variable regions of 9 strains, dfrA17-aadA5 in 2 strains, blaOXA-30-aadA1 in 70 strains, 2 strains were not detected resistance gene cassette, all resistance gene cassettes were dfrA1-sat1-aadA1 in class 2 integron variable regions.

CONCLUSIONThe muti-drug resistance of Shigella flexneri in Jinan was closely associated with integrons.

Adolescent ; Anti-Bacterial Agents ; pharmacology ; Child ; Child, Preschool ; Drug Resistance, Multiple, Bacterial ; genetics ; Dysentery, Bacillary ; microbiology ; Feces ; microbiology ; Humans ; Infant ; Integrons ; Polymerase Chain Reaction ; Shigella flexneri ; drug effects ; genetics

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.
Bacteria ; Carnobacterium ; Cellular Phone* ; Clone Cells ; Cloning, Organism ; Dentists* ; Fomites ; Hand ; Humans ; Lactobacillus ; Pseudomonadaceae ; Pseudomonas ; Saliva ; Shigella flexneri ; Staphylococcus aureus ; Staphylococcus epidermidis ; Streptococcus ; Streptococcus mitis

Infection with invasive Shigella species results in intestinal inflammation in humans but no symptoms in adult mice. To investigate why adult mice are resistant to invasive shigellae, 6~8-week-old mice were infected orally with S. flexneri 5a. Shigellae successfully colonized the small and large intestines. Mild cell death was seen but no inflammation. The infected bacteria were cleared 24 hours later. Microarray analysis of infected intestinal tissue showed that several genes that are involved with the sphingosine-1-phosphate (S1P) signaling pathway, a lipid mediator which mediates immune responses, were altered significantly. Shigella infection of a human intestinal cell line modulated host S1P-related genes to reduce S1P levels. In addition, co-administration of S1P with shigellae could induce inflammatory responses in the gut. Here we propose that Shigella species have evasion mechanisms that dampen host inflammatory responses by lowering host S1P levels in the gut of adult mice.
Adult ; Animals ; Bacteria ; Cell Death ; Cell Line ; Colon ; Humans ; Inflammation* ; Intestines ; Mice* ; Microarray Analysis ; Shigella ; Shigella flexneri*

BACKGROUND: Shigella is a frequent cause of bacterial dysentery in the developing world. Treatment with antibiotics is recommended for shigellosis, but the options are limited due to globally emerging resistance. This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella in China. METHODS: We studied the antimicrobial resistance profiles of 308 Shigella spp. strains (260 S. flexneri, 40 S. sonnei, 5 S. boydii, and 3 S. dysenteriae) isolated from fecal samples of patients (age, from 3 months to 92 yr) presenting with diarrhea in different districts of Anhui, China. The antimicrobial resistance of strains was determined by the agar dilution method according to the CSLI guidelines. RESULTS: The most common serogroup in the Shigella isolates was S. flexneri (n=260, 84.4%), followed by S. sonnei (n=40, 13.0%). The highest resistance rate was found for nalidixic acid (96.4%), followed by ampicillin (93.2%), tetracycline (90.9%), and trimethoprim/sulfamethoxazole (80.8%). Among the isolates tested, 280 (91.0%) were multidrug resistant (resistant to > or =2 agents). The most common resistance pattern was the combination of ampicillin, tetracycline, and trimethoprim/sulfamethoxazole (70.8%). Resistance to ampicillin and tetracycline were more common among S. flexneri than among S. sonnei isolates. CONCLUSIONS: S. flexneri is predominant in Anhui, China, and its higher antimicrobial resistance rate compared with that of S. sonnei is a cause for concern. Continuous monitoring of resistance patterns is necessary to control the spread of resistance in Shigella. The recommendations for antimicrobial treatment must be updated regularly based on surveillance results.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Ampicillin/pharmacology ; Anti-Infective Agents/*pharmacology ; Child ; Child, Preschool ; China ; Drug Resistance, Bacterial/drug effects ; Dysentery, Bacillary/*diagnosis/microbiology ; Feces/microbiology ; Humans ; Infant ; Microbial Sensitivity Tests ; Middle Aged ; Nalidixic Acid/pharmacology ; Shigella/*drug effects/isolation & purification ; Shigella flexneri/drug effects/isolation & purification ; Shigella sonnei/drug effects/isolation & purification ; Tetracycline/pharmacology ; Time Factors ; Trimethoprim-Sulfamethoxazole Combination/pharmacology ; Young Adult

O Antigens ; immunology ; Serotyping ; Shigella flexneri ; immunology