Aeromonas stool isolates from individuals with or without diarrhea in southern Taiwan: Predominance of Aeromonas veronii.
BACKGROUND
Although aeromonads are important pathogens causing invasive infections in southern Taiwan, Aeromonas-associated intestinal infections have been rarely mentioned.


PURPOSE
The aim of this study was to understand the frequency of isolation and clinical significance of aeromonads recovered from adult stool samples in southern Taiwan.


METHODS
During a 15-month study period, 514 adults with diarrhea and 167 asymptomatic controls were prospectively screened for the presence of aeromonads in stools. The identity of Aeromonas species was determined by the rpoD sequencing. Clinical information was retrieved from medical records, and in vitro cytotoxicity assay and polymerase chain reaction detection of putative virulent genes were performed.


RESULTS
Thirteen (2.5 %) of 514 diarrheal patients and six (3.6%) of 167 asymptomatic controls had Aeromonas isolates in their stools. Of 11 diarrheal patients with available clinical information, Aeromonas veronii, the predominant species, was noted in six patients, and another potential enteropathogen was present in four patients. The cytotoxicity of A. veronii isolates to the HT-29 cell line was more potent in the isolates from diarrheal patients than those from asymptomatic controls (p = 0.015). The cytotoxicity of A. veronii isolates was more potent than that of A. caviae from symptomatic patients (p = 0.001). Putative virulence markers, including AHCYTONE, ascV, ascF-ascG, and aexT, were detected exclusively in A. veronii. The presence of the ascV gene was associated with cytotoxicity in A. veronii isolates. All Aeromonas isolates were susceptible to varied antimicrobial agents, except ampicillin/sulbactam.


CONCLUSION
A. veronii is the predominant species in stools from individuals with or without diarrhea in southern Taiwan.
['Chen|Po-Lin|PL|', 'Tsai|Pei-Jane|PJ|', 'Chen|Chang-Shi|CS|', 'Lu|Ying-Chuan|YC|', 'Chen|Hung-Mo|HM|', 'Lee|Nan-Yao|NY|', 'Lee|Ching-Chi|CC|', 'Li|Chia-Wen|CW|', 'Li|Ming-Chi|MC|', 'Wu|Chi-Jung|CJ|', 'Ko|Wen-Chien|WC|']
D000328:Adult D000333:Aeromonas D000368:Aged D000369:Aged, 80 and over D000900:Anti-Bacterial Agents D001427:Bacterial Toxins D015415:Biomarkers D002460:Cell Line D012321:DNA-Directed RNA Polymerases D024881:Drug Resistance, Bacterial D005243:Feces D005260:Female D016905:Gram-Negative Bacterial Infections D019073:HT29 Cells D006801:Humans D008297:Male D008826:Microbial Sensitivity Tests D008875:Middle Aged D011446:Prospective Studies D012808:Sigma Factor D013624:Taiwan D037521:Virulence Factors
Diarrhea Taiwan Aeromonas veronii Cytotoxicity