Objective: To understand the virulence gene and drug resistance profile of Shigella sonnei outbreak in Huainan city, and conduct pathogenic traceability analysis. Methods: Water samples and feces related to an infectious diarrhea outbreak in Huainan city in August 2020 were collected for multiple pathogen detection. Virulence gene, drug sensitivity, pulse-field gel electrophoresis and whole genome sequencing of Shigella isolates were analyzed respectively. Results: 38 strains of Shigella sonnei were detected in 56 samples of mucilage feces with a positive rate 67.86%, and all serotypes were Shigella sonnei Phase I. Three strains of Shigella sonnei were detected by fluorescence PCR in the Gram-negative (GN) bacterial enrichment solution of terminal water and well water. Virulence genes were ipaH positive (38), ipaH/ial (31) and ipaH/ial/sen positive (1), respectively. The drug resistance spectrum showed that 9 of 14 antibiotics were 100% resistant, and only imipenem, chloramphenicol, ceftazidime and ciprofloxacin were effective drugs. XbaⅠ restriction enzyme map type of 36 isolates was completely consistent, and the ST type analysis of 3 strains was ST152. Whole genome sequencing and analysis verified that the outbreak was caused by a single clonal group of strains, and revealed that the isolates of the outbreak were clustered into a large cluster with 3 Chinese strains and 1 Korean strain in the database, far away from the strains of other countries. Conclusion: The outbreak is caused by a single clone of Shigella sonnei, which are low virulence strains and have multiple drug resistance.
Disease Outbreaks ; Dysentery, Bacillary/microbiology* ; Humans ; Shigella ; Shigella sonnei/genetics* ; Water/pharmacology*

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

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

We report a case of CTX-M-55-type extended-spectrum beta-lactamase (ESBL)-producing Shigella sonnei infection in a 27-year-old Korean woman who had traveled to China. The patient was admitted to the hospital due to abdominal pain, watery diarrhea, and fever (39.3degrees C). S. sonnei was isolated from her stool specimens, and the pathogen was found to be resistant to cefotaxime due to CTX-M-55-type ESBL. Insertion sequence (IS)Ecp1 was found upstream of the blaCTX-M-55 gene. The blaCTX-M-55 gene was transferred from the S. sonnei isolate to an Escherichia coli J53 recipient by conjugation. Pulsed-field gel electrophoresis and Southern blotting revealed that the blaCTX-M-55 gene was located on a plasmid of approximately 130 kb.
Adult ; Anti-Bacterial Agents/pharmacology ; Asian Continental Ancestry Group ; Cefotaxime/pharmacology ; China ; Drug Resistance, Bacterial/drug effects ; Dysentery, Bacillary/diagnosis/*microbiology ; Electrophoresis, Gel, Pulsed-Field ; Escherichia coli/metabolism ; Feces/microbiology ; Female ; Humans ; Plasmids/chemistry/genetics ; Republic of Korea ; Shigella sonnei/enzymology/*isolation & purification ; Travel ; beta-Lactamases/genetics/*metabolism

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

OBJECTIVETo explore the etiologic characteristics of bacillary dysentery found in Henan province, between year 2009 and 2010.

METHODSIn order to explore the distribution of bacterial types, drug susceptibility and the virulence gene carrier situation, 482 strains of Shigella isolated in Henan province between 2009 and 2010 were pathogen-detected and analyzed by serotype screening, anti microbial sensitivity test and PCR methods.

RESULTSThe 482 isolated strains were confirmed to be Shigella by both morphological and biochemical tests. The Shigella strains were divided into 13 serotypes in 2 groups, namely Shigella flexneri (B group) accounting for 72.0% (347/482) and Shigella sonnei (D group), accounting for 28.0% (135/482). The detection rate of Serotype F2a, as the dominant type of Shigella flexneri, decreased from 43.4% (106/245) in 2009 to 33.8% (80/237) in 2010; while the detection rate of Shigella sonnei increased from 13.1% (32/245) to 43.5% (103/237) in the same period. The results of microbial sensitivity tests carried out in year 2009 and 2010, both showed that over 98% of the 185 studied strains were resistant to ampicillin (AMP), trimethoprim-pyrimidine (TMP), tetracycline (TE), streptomycin (S) and nalidixic acid (NA).182 strains were recruited in the virulence factors detection, 67.6% (123/182) of which carried Shigella Enterotoxin 1B (set1B), Shigella Enterotoxin 2 (set2), invasive plasmid antigen H (ipaH) or invasion-related virulence factors (ial) and 24.2% (44/182) of which carried 3 virulence factors mentioned above.

CONCLUSIONThe prevalent serotypes of Shigella in Henan province have changed in recent years. The isolated strains showed high resistance to common antibacterial drugs and generally carried virulence factors.

China ; epidemiology ; Dysentery, Bacillary ; epidemiology ; microbiology ; prevention & control ; Female ; Humans ; Male ; Microbial Sensitivity Tests ; Population Surveillance ; Prevalence ; Serotyping ; Shiga Toxins ; genetics ; Shigella ; genetics ; isolation & purification

We report a recent case in which ciprofloxacin-resistant Shigella flexneri was isolated from a 23-yr-old female patient with a history of travel to India. Prior to her admission to our internal medicine department, she experienced symptoms of high fever and generalized weakness from continuous watery diarrhea that developed midway during the trip. S. flexneri was isolated from the stool culture. Despite initial treatment with ciprofloxacin, the stool cultures continued to show S. flexneri growth. In the susceptibility test for antibiotics of the quinolone family, the isolate showed resistance to ciprofloxacin (minimum inhibitory concentration [MIC], 8 microg/mL), norfloxacin (MIC, 32 microg/mL), ofloxacin (MIC, 8 microg/mL), nalidixic acid (MIC, 256 microg/mL), and intermediate resistance to levofloxacin (MIC, 4 microg/mL). In molecular studies for quinolone resistance related genes, plasmid borne-quinolone resistance genes such as qnrA, qnrB, qnrS, aac(6')-Ib-cr, qepA, and oqxAB were not detected. Two mutations were observed in gyrA (248C-->T, 259G-->A) and 1 mutation in parC (239G-->T). The molecular characteristics of the isolated S. flexneri showed that the isolate was more similar to the strains isolated from the dysentery outbreak in India than those isolated from Korea.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics/metabolism ; Drug Resistance, Bacterial/drug effects ; Dysentery, Bacillary/microbiology ; Feces/microbiology ; Female ; Humans ; India ; Mutation ; Quinolones/*pharmacology ; Shigella flexneri/drug effects/*isolation & purification/metabolism ; Travel ; Young Adult

China ; epidemiology ; Dysentery, Bacillary ; epidemiology ; microbiology ; Humans ; Shiga Toxin ; Shigella ; classification

China ; epidemiology ; Drug Resistance, Bacterial ; Dysentery, Bacillary ; epidemiology ; microbiology ; Humans ; Serotyping ; Shigella ; classification ; drug effects ; isolation & purification

Child, Preschool ; China ; epidemiology ; Dysentery, Bacillary ; epidemiology ; microbiology ; prevention & control ; Female ; Genes, Bacterial ; Humans ; Infant ; Male ; Shigella ; genetics ; isolation & purification ; pathogenicity