Phenotypic and genotypic characteristics of ESBL and AmpC producing organisms associated with bacteraemia in Ho Chi Minh City, Vietnam

Abstract

BackgroundBroad-spectrum antimicrobials are commonly used as empirical therapy for infections of presumed bacterial origin. Increasing resistance to these antimicrobial agents has prompted the need for alternative therapies and more effective surveillance. Better surveillance leads to more informed and improved delivery of therapeutic interventions, potentially leading to better treatment outcomes.MethodsWe screened 1017 Gram negative bacteria (excluding Pseudomonas spp. and Acinetobacter spp.) isolated between 2011 and 2013 from positive blood cultures for susceptibility against third generation cephalosporins, ESBL and/or AmpC production, and associated ESBL/AmpC genes, at the Hospital for Tropical Diseases in Ho Chi Minh City.ResultsPhenotypic screening found that 304/1017 (30%) organisms were resistance to third generation cephalosporins; 172/1017 (16.9%) of isolates exhibited ESBL activity, 6.2% (63/1017) had AmpC activity, and 0.5% (5/1017) had both ESBL and AmpC activity. E. coli and Aeromonas spp. were the most common organisms associated with ESBL and AmpC phenotypes, respectively. Nearly half of the AmpC producers harboured an ESBL gene. There was no significant difference (p > 0.05) between the antimicrobial resistance phenotypes of the organisms associated with community and hospital-acquired infections.ConclusionAmpC and ESBL producing organisms were commonly associated with bloodstream infections in this setting, with antimicrobial resistant organisms being equally distributed between infections originating from the community and healthcare settings. Aeromonas spp., which was associated with bloodstream infections in cirrhotic/hepatitis patients, were the most abundant AmpC producing organism. We conclude that empirical monotherapy with third generation cephalosporins may not be optimum in this setting.Electronic supplementary materialThe online version of this article (10.1186/s13756-017-0265-1) contains supplementary material, which is available to authorized users.

Molecular characterization and distribution of cephalosporin resistance determinants in Escherichia coli and Klebsiella pneumoniae isolated from patients attending Kampala International University Teaching Hospital in Bushenyi, Western Uganda

“…Thus, a low prevalence (9.4%) of AmpC β-lactamase producers was registered by this study. These findings corroborate well with other studies that reported relatively low prevalence (0.5%-30%) of coproduction of ESBLs and AmpCs [29][30][31][32] E. coli (81.2%) isolates were more predominant than K. pneumoniae (18.8%) among the archived samples. This is in agreement with other studies that attempted to establish the prevalence of ESBLs producing Enterobacteriaceae in Uganda [9,10,25,27].…”

High clinical impact of rapid susceptibility testing on CHROMID ESBL® medium directly from swabs

“…Nevertheless, this lack of growth is useful in clinical practice because it signifies that these microorganisms are, in principle, not relevant for the diagnosis. E. cloacae and K. aerogenes were resistant to FOX and susceptible to both FEP and IMP, in line with previous studies (32,(42)(43)(44)(45). Some isolates grown on the medium exhibited susceptibility to FOX and IMP with variable resistance to FEP, a similar phenotype to that of microorganisms with ESBL resistance, which may also have been present.…”

Prevalence of Potentially Pathogenic Antibiotic-Resistant Aeromonas spp. in Treated Urban Wastewater Effluents versus Recipient Riverine Populations: a 3-Year Comparative Study

“…Our findings identified cytotoxic activity among over 50% of A. veronii group and A. hydrophila isolates as well as 30% of MDR isolates, thus posing a potential health risk. With hypervirulent strains of A. hydrophila jeopardizing aquaculture (72) and ESBL-producing strains associating with bacteremia (73,74), it is critical that we continue to assess antibiotic resistance with pathogenic phenotypes to elaborate on the potential health risk. Previously, our group and others have identified a correlation with Aeromonas strains encoding serine protease and aerolysin genes with cytotoxic phenotypes (21,75) and disease (11,76).…”