Phenotypic and Genotypic Antimicrobial Resistance Traits of Vibrio cholerae Non-O1/Non-O139 Isolated From a Large Austrian Lake Frequently Associated With Cases of Human Infection

Abstract

Vibrio cholerae belonging to serogroups other than O1 and O139 are opportunistic pathogens which cause infections with a variety of clinical symptoms. Due to the increasing number of V. cholerae non-O1/non-O139 infections in association with recreational waters in the past two decades, they have received increasing attention in recent literature and by public health authorities. Since the treatment of choice is the administration of antibiotics, we investigated the distribution of antimicrobial resistance properties in a V. cholerae non-O1/non-O139 population in a large Austrian lake intensively used for recreation and in epidemiologically linked clinical isolates. In total, 82 environmental isolates - selected on the basis of comprehensive phylogenetic information - and nine clinical isolates were analyzed for their phenotypic antimicrobial susceptibility. The genomes of 46 environmental and eight clinical strains were screened for known genetic antimicrobial resistance traits in CARD and ResFinder databases. In general, antimicrobial susceptibility of the investigated V. cholerae population was high. The environmental strains were susceptible against most of the 16 tested antibiotics, except sulfonamides (97.5% resistant strains), streptomycin (39% resistant) and ampicillin (20.7% resistant). Clinical isolates partly showed additional resistance to amoxicillin-clavulanic acid. Genome analysis showed that crp, a regulator of multidrug efflux genes, and the bicyclomycin/multidrug efflux system of V. cholerae were present in all isolates. Nine isolates additionally carried variants of blaCARB–7 and blaCARB–9, determinants of beta-lactam resistance and six isolates carried catB9, a determinant of phenicol resistance. Three isolates had both blaCARB–7 and catB9. In 27 isolates, five out of six subfamilies of the MATE-family were present. For all isolates no genes conferring resistance to aminoglycosides, macrolides and sulfonamides were detected. The apparent lack of either known antimicrobial resistance traits or mobile genetic elements indicates that in cholera non-epidemic regions of the world, V. cholerae non-O1/non-O139 play a minor role as a reservoir of resistance in the environment. The discrepancies between the phenotypic and genome-based antimicrobial resistance assessment show that for V. cholerae non-O1/non-O139, resistance databases are currently inappropriate for an assessment of antimicrobial resistance. Continuous collection of both data over time may solve such discrepancies between genotype and phenotype in the future.

Virulence, Resistance, and Genomic Fingerprint Traits ofVibrio choleraeIsolated from 12 Species of Aquatic Products in Shanghai, China

“…19 Resistant V. cholerae isolates that originated from clinical and environmental sources have been reported. 18,[20][21][22][23][24] For example, during an outbreak of cholera in Guinea-Bissau in 1996-1997, casefatality rates increased from 1% to 5.3% after the emergence of multidrug-resistant (MDR) V. cholerae. 20 Chomvarin et al reported that V. cholerae O1 strains (n = 35) isolated from clinical samples and natural surface water sources in Thailand were resistant to trimethoprim (TM)/sulfamethoxazole and/or tetracycline (TET)/or ampicillin (AMP).…”

“…24 Lepuschitz et al investigated V. cholerae isolates (n = 82) recovered from an Austrian lake, and they found that the majority of the isolates showed resistance to sulfonamides (n = 80), and some to streptomycin (STR; n = 32) and AMP (n = 17). 23 Xu et al reported that *65.3% of V. cholerae isolates (n = 400) from four species of commonly consumed fish in Shanghai, China were resistant to STR, followed by AMP (44.5%) and rifampicin (RIF; 24.0%). 18 Heavy metals used in mining, fossil fuel combustion, and agricultural practices can enter the food chain, such as cadmium (Cd), chromium (Cr), mercury (Hg), and Pb.…”

First Experimental Evidence for the Presence of Potentially Toxic Vibrio cholerae in Snails, and Virulence, Cross-Resistance and Genetic Diversity of the Bacterium in 36 Species of Aquatic Food Animals

“…The inappropriate use of antibiotics has resulted in considerably increased toxicogenic V. cholerae and difficulties in clinical case treatment [ 39 , 40 ]. The aquatic environment is a reservoir of V. cholerae and might be an important source of resistant strains.…”

Mobile Genetic Elements of Vibrio cholerae and the Evolution of Its Antimicrobial Resistance

“…Clinical strains may also contaminate environmental strains (25). The discovery of MDR environmental isolates of VC without MGEs are also of major concern (210,211). Chromosomal inheritance of genes acquired by HGT and integrated with the chromosome are vertically transferred leading to inherited AMR traits and highlights the eventual disastrous consequences of HGT lying in chromosomal inheritance of laterally acquired traits (212).…”

“…These integrate with the chromosome and are vertically inherited by later generations (212). Therefore, acquisition of AMR by HGT (210,211) leads to persistence of AMR against common antibiotics in future generations (212). Tables 3-5 enumerate the different resistance markers associated with VC antibiotic resistance (AR) and which are useful for rapid screening and molecular detection of AMR.…”