OBJECTIVE: Aeromonas has recently been recognized as an emerging human pathogen. Aeromonas-associated diarrhea is a phenomenon occurring worldwide. This study was designed to determine the prevalence, genetic diversity, antibiotic resistance, and pathogenicity of Aeromonas strains isolated from food products in Shanghai. METHODS: Aeromonas isolates ( n = 79) collected from food samples were analyzed using concatenated gyrB- cpn60 sequencing. The antibiotic resistance of these isolates was determined using antimicrobial susceptibility testing. Pathogenicity was assessed using β-hemolytic, extracellular protease, virulence gene detection, C. elegans liquid toxicity (LT), and cytotoxicity assays. RESULTS: Eight different species were identified among the 79 isolates. The most prevalent Aeromonas species were A. veronii [62 (78.5%)], A. caviae [6 (7.6%)], A. dhakensis [3 (3.8%)], and A. salmonicida [3 (3.8%)]. The Aeromonas isolates were divided into 73 sequence types (STs), of which 65 were novel. The isolates were hemolytic (45.6%) and protease-positive (81.0%). The most prevalent virulence genes were act (73.4%), fla (69.6%), aexT (36.7%), and ascV (30.4%). The results of C. elegans LT and cytotoxicity assays revealed that A. dhakensis and A. hydrophila were more virulent than A. veronii, A. caviae, and A. bivalvium. Antibiotic resistance genes [ tetE, blaTEM, tetA, qnrS, aac(6)-Ib, mcr -1, and mcr-3] were detected in the isolates. The multidrug-resistance rate of the Aeromonas isolates was 11.4%, and 93.7% of the Aeromonas isolates were resistant to cefazolin. CONCLUSION The taxonomy, antibiotic resistance, and pathogenicity of different Aeromonas species varied. The Aeromonas isolates A. dhakensis and A. hydrophila were highly pathogenic, indicating that food-derived Aeromonas isolates are potential risks for public health and food safety. The monitoring of food quality and safety will result in better prevention and treatment strategies to control diarrhea illnesses in China.
Aeromonas/genetics* ; Animals ; Anti-Bacterial Agents/pharmacology* ; Caenorhabditis elegans ; Cefazolin ; China/epidemiology* ; Diarrhea ; Drug Resistance, Multiple, Bacterial/genetics* ; Genetic Variation ; Humans ; Peptide Hydrolases/genetics* ; Virulence/genetics*

To effectively solve the serious impact of high oil in the kitchen wastewater on the downstream treatment process, an excellent oil-degrading strain Aeromonas allosaccarophila CY-01 was immobilized to prepare Chitosan-Aeromonas pellets (CH-CY01) by using chitosan as a carrier. Oil degradation condition and efficiency of CH-CY01 pellets were assessed. The growth of immobilized CH-CY01 was almost unaffected, and the maximum degradation rate of soybean oil was 89.7%. Especially at 0.5% NaCl concentration, oil degradation efficiency of CH-CY01 was increased by 20% compared with free cells. In the presence of a surfactant (sodium dodecylbenzene sulfonate) at 1 mg/L, the degradation efficiency of oil by CH-CY01 was increased by 40%. Moreover, using the high-oil catering wastewater as the substrate, more than 80% of the solid oil was degraded with 1% (V/V) CH-CY01 pellets treatment for 7 days, significantly higher than that of free cells. In summary, immobilized CH-CY01 significantly improved the efficiency of oil degradation.
Aeromonas ; Chitosan ; Surface-Active Agents ; Waste Water

Objective: This study was performed to compare the genetic diversity, virulence, and antimicrobial resistance of Methods: A total of 38 clinical strains and 19 strains from healthy individuals were isolated from the samples collected in Ma'anshan City, Anhui Province. Their taxonomy was investigated using concatenated Results: The 57 Conclusions The taxonomy, virulence properties, and antibiotic resistance of
Aeromonas/pathogenicity* ; Case-Control Studies ; Drug Resistance, Bacterial/genetics* ; Genetic Variation ; Humans ; Virulence Factors/genetics*

The aim of this study was to investigate the expression of MHCⅠ gene in different tissues of Rana dybowskii under the stress of Aeromonas hydrophila (Ah), and to provide evidence for revealing the anti-infective immune response mechanism of amphibians. The experimental animal model of Aeromonas hydrophila infection was first constructed, and the pathological changes were observed by HE staining. The MHCⅠ gene α1+α2 peptide binding region of Rana dybowskii was cloned by RT-PCR and analyzed by bioinformatics. Real-time PCR was used to detect the transcription level of MHCⅠ in different tissues under Ah stress. After Ah infection, the skin, liver and muscle tissues showed signs of cell structure disappearance and texture disorder. The MHCⅠ gene α1+α2 peptide binding region fragment was 494 bp, encoding 164 amino acids, and homology with amphibians. Above 77%, the homology with mammals was as low as 14.96%, indicating that the α1+α2 region of MHC gene was less conserved among different species. The results of real-time PCR show that the liver, spleen and kidney of the experimental group were under Ah stress. The transcript levels of MHCⅠ gene in skin and muscle tissues were higher than those in the control group at 72 h, but the time to peak of each tissue was different (P<0.01), indicating that the response time of MHCⅠ gene in different tissues was different under Ah stress. This study provides a reference for further exploring the immune function of MHC molecules in anti-infection.
Aeromonas hydrophila ; Animals ; Gene Expression Profiling ; Gene Expression Regulation ; immunology ; Gram-Negative Bacterial Infections ; immunology ; Liver ; metabolism ; Ranidae ; genetics ; immunology ; microbiology ; Skin ; metabolism

Objective: This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of isolates from clinical patients, tap water systems, and food. Methods: Ninety isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing (MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing. Results: The 90 isolates were divided into 84 sequence types, 80 of which were novel, indicating high genetic diversity. The isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes , , , and found in 47 (52.2%), 13 (14.4%), 22 (24.4%), and 12 (13.3%) of the isolates, respectively. The majority of the isolates (≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol, gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new variant. Conclusions Sequence type, virulence properties, and antibiotic resistance vary in isolates from clinical patients, tap water systems, and food.
Aeromonas ; drug effects ; genetics ; isolation & purification ; pathogenicity ; Anti-Bacterial Agents ; pharmacology ; China ; Drinking Water ; microbiology ; Drug Resistance, Bacterial ; Food Microbiology ; Genetic Variation ; Gram-Negative Bacterial Infections ; microbiology ; Species Specificity ; Virulence

PURPOSE: We report a case of Aeromonas keratitis presenting as radial keratoneuritis. CASE SUMMARY: A 33-year-old woman with a history of cleaning her contact lenses with tap water presented with decreased visual acuity for 1 day in the left eye. The patient showed diffuse corneal edema, stromal infiltration, and radial keratoneuritis, which were thought to be pathognomonic for Aeromonas keratitis. Based on the patient's clinical findings and past history, a diagnosis of Aeromonas keratitis was made and she was prescribed topical fortified cefazolin (50 mg/mL, 5%), tobramycin (3 mg/mL), and 0.02% chlorhexidine per hour. Culture results from the contact lens and contact lens solution confirmed infection by Aeromonas hydrophilia. Polymerase chain reaction results for Aeromonas were negative. After 8 days of treatment, the uncorrected visual acuity was 0.7/0.3 with improvement in her corneal findings. CONCLUSIONS: Radial keratoneuritis is not always pathognomic for Aeromonas keratitis and can be present in Aeromonas keratitis. Therefore, ophthalmologists should be cautious when interpreting this clinical sign.
Adult ; Aeromonas ; Cefazolin ; Chlorhexidine ; Contact Lens Solutions ; Contact Lenses ; Cornea ; Corneal Edema ; Diagnosis ; Female ; Humans ; Keratitis ; Polymerase Chain Reaction ; Tobramycin ; Visual Acuity ; Water

As one of the most common pathogens in aquatic animals, Aeromonas hydrophila exhibits a wide range of pathogenicity. Due to factors like unreasonable use of antibiotics and horizontal gene transfer mediated by plasmids, many resistant strains of Aeromonas hydrophila were isolated from ready-to-eat seafood products in retail markets, supermarkets and restaurants. These strains carry many resistance genes. Therefore, it is essential to explore the key control points, and seek for prevention and control strategies so as to effectively alleviate antibiotic resistance. We review here the prevalence of drug resistance of Aeromonas hydrophila in China, and its main infection and resistance mechanisms, and the main means and strategies for reducing and preventing drug resistance. We also address further research directions and focus on drug resistance in Aeromonas hydrophila of the aquatic product.
Aeromonas hydrophila ; drug effects ; Animals ; Anti-Bacterial Agents ; pharmacology ; China ; epidemiology ; Drug Resistance, Bacterial ; Fish Diseases ; epidemiology ; microbiology ; Fisheries ; Fishes ; Gram-Negative Bacterial Infections ; epidemiology ; microbiology ; Research

Objective: To investigate the clinical and laboratory features of Aeromonas bacteremia in patients with hematological diseases, and provide evidence for the prevention and treatment of Aeromonas infection. Methods: A retrospective study of patients with bloodstream infection of Aeromonas in our hospital from January 2014 to December 2018 was carried out. The clinical characteristics, antimicrobial susceptibility, infection seasons, antimicrobial therapy and evolution were analyzed. Results: A total of 42 patients with hematological diseases had Aeromonas bloodstream infection within 5 years. Among them, 39 cases (92.9%) of bloodstream infection occurred in the stage of neutropenia. The median time of fever was 4 (1-27) d, 22 (52.4%) patients only had fever, 6 (14.3%) with gastrointestinal symptoms (abdominal pain, diarrhea, nausea, upper gastrointestinal bleeding) , 8 (19.0%) with pulmonary infection, 13 (31.0%) with skin and soft tissue infections. Seven patients (16.7%) died with skin and soft tissue infection. The resistance of Aeromonas to carbapenems was 68.3%-70.7%, while the resistance rate to cephalosporins, quinolones and aminoglycosides were less than 10%. Conclusions: Aeromonas bacteremia in patients with hematological diseases mainly occur in the neutropenia stage, usually with symptom like fever. The mortality is increased when accompanied by skin and soft tissue infection. Antibiotic use should be based on susceptibility results, and avoid the use of carbapenems.
Aeromonas ; Anti-Bacterial Agents ; Bacteremia ; Data Analysis ; Hematologic Diseases ; Humans ; Retrospective Studies

BACKGROUND: We attempted to determine the characteristics of diarrheal pathogens according to species, seasonal variations, and patient age using multiplex PCR for the epidemiologic study of diarrheal disease in Jeju Island. METHODS: From March 2015 to Feb 2017, stool specimens were collected from 537 diarrheal patients older than 16 years. Multiplex PCR was used to identify pathogens and found Group A Rotavirus, enteric Adenovirus, Norovirus GI/GII, Astrovirus, Salmonella spp., Shigella spp., Vibrio spp., Campylobacter spp., Clostridium difficile toxin B (CDB), Clostridium perfringens, Yersinia enterocolitica, Aeromonas spp., Escherichia coli O157:H7, and verocytotoxin-producing E. coli (VTEC). RESULTS: Pathogens were isolated from 221 of 537 samples (41.2%); 9.3% were positive only for viral pathogens; 30.2%, only for bacterial pathogens; and 1.7%, for both viral and bacterial pathogens. Bacteria were more prevalent in spring, summer, and autumn, but viral pathogens were more prevalent in winter. Overall prevalence were Campylobacter spp. (26.7%), Clostridium perfringens (23.9%); Norovirus GII (11.4%), CDB (8.2%), Aeromonas spp. (6.3%), Group A Rotavirus (5.1%), Salmonella spp. (3.9%), Astrovirus (3.9%), Norovirus GI (3.1%), Vibrio spp (2.7%), enteric Adenovirus (1.6%), Shigella spp. (1.2%), VTEC (1.2%), and Yersinia enterocolitica (0.4%). Group A Rotavirus and Norovirus GII were more prevalent in winter and early spring. Campylobacter spp., CDB, and C. perfringens were detected frequently, without seasonal variation. CONCLUSION: Bacterial pathogens are more prevalent than viruses in acute diarrhea in adults living in Jeju Island, especially in spring, summer, and autumn. Viral pathogens are prevalent in winter. Campylobacter spp., CDB, and Clostridium perfringens are the major pathogens occurring without seasonal variations. These data will be helpful in identifying diarrheal pathogens and for treatments and prevention strategies.
Adenoviridae ; Adult* ; Aeromonas ; Bacteria ; Campylobacter ; Clostridium difficile ; Clostridium perfringens ; Diarrhea ; Epidemiologic Studies* ; Epidemiology ; Escherichia coli ; Humans ; Multiplex Polymerase Chain Reaction* ; Norovirus ; Prevalence ; Rotavirus ; Salmonella ; Seasons ; Shiga-Toxigenic Escherichia coli ; Shigella ; Vibrio ; Yersinia enterocolitica

Peritoneal dialysis (PD)-related peritonitis is a major cause of injury and technique failure in patients undergoing PD. Aeromonas hydrophila is ubiquitous in the environment, and is a Gram-negative rod associated with infections in fish and amphibians in most cases; however, it can also cause opportunistic infections in immunocompromised patients. We report a case of A. hydrophila peritonitis in a 56-year-old male on automated PD. Peritonitis may have been caused by contamination of the Set Plus, a component of the automated peritoneal dialysis device. Although Set Plus is disposable, the patient reused the product by cleansing with tap water. He was successfully treated with intraperitoneally-administered ceftazidime and has been well without recurrence for more than 2 years.
Aeromonas hydrophila ; Aeromonas ; Amphibians ; Ceftazidime ; Humans ; Immunocompromised Host ; Male ; Middle Aged ; Opportunistic Infections ; Peritoneal Dialysis ; Peritonitis ; Recurrence ; Water