Unusual Severe Extra-Intestinal Manifestations of a Common Enteric Pathogen- Aeromonas Spp

Abstract

Introduction: Aeromonas spp. are halophilic, Gram-negative bacilli. They are widely distributed in the soil and aquatic environment and have been associated with various extra-intestinal infections, such as skin and soft-tissue infections, meningitis, bacteraemia etc. The most common species associated with extra-intestinal infection is Aeromonas hydrophila.

Aim: To get the overview of clinical presentations, underlying predisposing factors associated with the extra-intestinal infections caused by Aeromonas species and their antimicrobial susceptibility pattern.

Materials and methods: Extra-intestinal cases of Aeromonas spp. admitted during December 2015 to October 2016 in the tertiary care hospital of South Karnataka coastal region were analysed retrospectively. The isolates were identified by Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) VITEK^®MS and antimicrobial susceptibility testing was performed by VITEK^®2 system (bioMérieux, Inc., Durham, NC) respectively. Clinical manifestations and management of the cases were noted from the clinical records. Clinical and microbiological findings presented as mean±standard deviation, frequency and percentage.

Results: We included 26 cases in this study, from whom Aeromonas spp. were isolated alone or with another microorganism. Most widespread infection was Skin and Soft Tissue Infection (SSTI) (24, 92.3%). In 50% (12/24) cases, SSTI developed due to trauma. In 45.8% (11/24), underlying co-morbid conditions were present. The common site of infection was lower extremities (16/24, 66.7%) and 62.5% (15/24) of them presented with severe gangrene of the affected site. Other than SSTI, we encountered with two cases of keratitis and cholangitis respectively. A. hydrophila were frequently isolated species (23/26, 88.5%). The analysis of antimicrobial susceptibility showed, 13% isolates were Multidrug Resistant (MDR). Carbapenem resistance was also noted.

Conclusion: We had isolated Aeromonas spp. from different extra-intestinal sites. Most common extra-intestinal manifestation by this organism was post-traumatic wound infection. Clinical spectrum of this infection confused the clinician with other organisms like group B Streptococcus, Clostridium spp. etc., and mislead them in empirical management. Finally with the microbiological support all the cases were treated either conservatively or in combination with surgical debridement or amputation depending on the situation.

Keywords: Multidrug resistance; Trauma; Wound infection.

[Table/Fig-2]:

Antibiotic resistant pattern of the isolated Aeromonas spp.