Absence of Escherichia coli O157:H7 Serotype in Small Indian Mongooses (Herpestes auropunctatus) in Grenada and Antimicrobial Drug Resistance of the non-O157 Isolates

Aim: To determine the occurrence of the E. coli including the O157:H7 serotype in mongooses and their antimicrobial drug resistance in Grenada.
Study Design: Experimental based study of feces of mongooses captured from six parishes of Grenada from April 2011 to March 2013 during an active rabies surveillance program.
Methodology: Fecal samples from 156 mongooses were cultured for E. coli and tested for O157:H7 serotype by the presence of non-sorbitol fermenting colonies and a positive reaction to O157-agglutination latex kits.
Results: Of the 156 mongooses, 71 (46%) were culture positive for E. coli. A total of 213 E. coli isolates were recovered and examined for the presence of non-sorbitol fermenting colonies and O157-agglutination. Of the 213 E. coli isolates, only 8 (4%) were non-sorbitol fermenters. However, none of the 213 isolates gave a positive reaction (O157-agglutinating) to the two E. coli O157:H7 latex kits. Antimicrobial susceptibility tests against 12 drugs revealed a low resistance rates to ampicillin (8%), amoxicillin-clavulanic acid (0.5%), ciprofloxacin (1.4%), enrofloxacin (2.3%), gentamicin (0.5%), nalidixic acid (3.3%), and trimethoprim-sulfamethoxazole (5.6%). High resistance rates to streptomycin (38%) and tetracycline (36%) was observed among the E. coli isolates. The susceptibility rate to ampicillin, amoxicillin-clavulanic acid, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, imipenem, nalidixic acid and trimethoprim-sulfamethoxazole ranged from 86.9 to 100%. Resistance to two or more antibiotics was observed in 57 (27%) of the E. coli isolates recovered.
Conclusion: This study showed that presently, mongooses in Grenada are neither a reservoir for the E. coli O157:H7 serotype nor for multiple drug resistant E. coli strains. Among the 213 non-O157:H7 E. coli isolates, the resistance rate to drugs other than streptomycin and tetracycline was very low.