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

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at 50℃~95℃ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.
Acetic Acid ; Bacillus cereus ; Bacteria ; Breast ; Chickens ; Citric Acid ; Citrus paradisi ; Egg White ; Escherichia coli ; Food Industry ; Hot Temperature ; Hydrogen-Ion Concentration ; Klebsiella pneumoniae ; Lactic Acid ; Lactobacillus rhamnosus ; Lactobacillus ; Listeria ; Listeria monocytogenes ; Meat ; Muramidase ; Proteus vulgaris ; Pseudomonas aeruginosa ; Pseudomonas fluorescens ; Shigella sonnei ; Staphylococcus aureus ; Vibrio parahaemolyticus

BACKGROUND/AIMS: A limited number of studies are available regarding the long-term natural history of post-infectious irritable bowel syndrome (PI-IBS). We aimed to investigate the long-term clinical course of PI-IBS. METHODS: A prospective cohort study was conducted from a 2001 shigellosis outbreak in a Korean hospital with about 2000 employees. A cohort of 124 hospital employees who were infected by Shigella sonnei due to contaminated food in the cafeteria, and 105 sex- and age-matched, non-infected, controls were serially followed for their bowel symptoms by questionnaire surveys for 10 years. RESULTS: The Shigella-infected cohort showed significantly higher odds ratio for irritable bowel syndrome (IBS) at 1-year (11.90; 95% CI, 1.49-95.58) and 3-year (3.93; 95% CI, 1.20-12.86) follow-up, compared to their controls. However, corresponding odds ratio for PI-IBS was not significantly increased at 5-year (1.88; 95% CI, 0.64-5.54) and 8-year (1.87; 95% CI, 0.62-5.19) follow-up. At 10-year follow-up survey, the prevalence of IBS was similar for the Shigella-infected cohort and their controls (23.3% versus 19.7%, P = 0.703). Risk factors which were independently associated with PI-IBS among the Shigella-infected cohort included younger age, previous history of functional bowel disorder, and longer duration of diarrhea at baseline. CONCLUSIONS: Patients who were infected by Shigella sonnei experienced significantly increased risk of IBS until 3 years after shigellosis, and modestly increased risk until 8 years, but showed similar risk of IBS with uninfected controls at 10 years post-infection. PI-IBS is quite a chronic disorder, and follows a long-term natural course.
Cohort Studies ; Diarrhea ; Dysentery ; Dysentery, Bacillary* ; Follow-Up Studies* ; Humans ; Irritable Bowel Syndrome* ; Natural History ; Odds Ratio ; Prevalence ; Prognosis ; Prospective Studies ; Risk Factors ; Shigella ; Shigella sonnei

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*

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

Shigellosis may mimic acute appendicitis clinically, but Shigella species rarely cause appendicitis. We experienced acute appendicitis with perforation caused by Shigella sonnei in a 24-year-old woman who had traveled abroad.
Appendicitis ; Dysentery, Bacillary ; Female ; Humans ; Hydrazines ; Shigella ; Shigella sonnei ; Young Adult

OBJECTIVES: In September 2008, an outbreak of diarrhea occurred among students attending Y school in Yeongcheon-si. Shigella sonnei was cultured from some of the rectal swabs. An epidemiological investigation was carried out to determine the source of the infection and the mode of transmission of the shigellosis outbreak. METHODS: The index case lived in the D rehabilitation facility in Gyeongsan-si and an additional epidemiological investigation was carried out there. The cases could not be questioned due to their mental handicaps. The teachers were interviewed instead. A patient case was defined as a resident with diarrhea more than one time a day from September 18 to September 26, 2008 or a resident with confirmed Shigella sonnei at the Y school or the D rehabilitation facility. RESULTS: The attack rate was 1.2% (8 persons) among 659 persons in the Y school and D rehabilitation facility. Five persons were microbiologically confirmed to have the infection and three persons were diagnosed on the basis of symptoms. Shigella sonnei was cultured from five of the 659 rectal swabs. However, 80 environmental specimens including drinking water, preserved foods, and cooking utensils were negative. All eight patients were Y school students and had been living in group boarding and lodging. Six of them lived in the D rehabilitation facility and two lived in the dormitory at the Y school. Five cases showed pulsed-field gel electrophoresis patterns that were identical for Shigella sonnei. CONCLUSIONS: The results of this study showed that the infection source of the shigellosis outbreak, in the two places, were identical. It is likely that the infections initially spread from a teacher or volunteer and then among the students.
Cooking and Eating Utensils ; Diarrhea ; Disabled Persons ; Disease Outbreaks ; Drinking Water ; Dysentery, Bacillary ; Electrophoresis, Gel, Pulsed-Field ; Food, Preserved ; Humans ; Intellectual Disability ; Korea ; Shigella ; Shigella sonnei

OBJECTIVETo explore the epidemic characteristics of bacterial dysentery in Jinan municipality, and to provide scientific basis for effective strategy for bacterial dysentery control.

METHODSThe epidemiological characteristics of bacillary dysentery in Jinan from 1951 to 2005 were analyzed. A total of 485,333 cases in the span of 50 years were recorded, while the population-based case distribution was less than the total cases due to the data incompleteness during the Cultural Revolution.

RESULTSThe incidence of bacillary dysentery in Jinan has been decreasing by years with average incidence rate of 283.10/100,000. The significant differences were observed among the incidence rates of various ages(chi2 = 14.99, P < 0.05). There were four epidemic peaks, and all the incidence rates were about 1000/100,000. Age of onset mainly concentrated in the 0-4 years old, 20-years old and 30-years old. In terms of occupational distribution, workers accounted for 30.31%, the living-scattered children accounted for 22.71%, and the farmers accounted for 17.90%. The incidence focus was from July to September, which accounted for 71.57%. The peak of incidence emerged in August. The highest incidence in urban was 550.94/100,000.

CONCLUSIONThrough the efforts of several generations of health workers, the incidence of bacillary dysentery in Jinan has been basically brought under control. Further step should be taken for the control of bacterial dysentery in urban areas and the management of bacterial dysentery in rural areas. Moreover, the biological characteristics of F2a should be a focus for the future study.